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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dlmglue.c
4 *
5 * Code which implements an OCFS2 specific interface to our DLM.
6 *
7 * Copyright (C) 2003, 2004 Oracle. All rights reserved.
8 */
9
10#include <linux/types.h>
11#include <linux/slab.h>
12#include <linux/highmem.h>
13#include <linux/mm.h>
14#include <linux/kthread.h>
15#include <linux/pagemap.h>
16#include <linux/debugfs.h>
17#include <linux/seq_file.h>
18#include <linux/time.h>
19#include <linux/delay.h>
20#include <linux/quotaops.h>
21#include <linux/sched/signal.h>
22
23#define MLOG_MASK_PREFIX ML_DLM_GLUE
24#include <cluster/masklog.h>
25
26#include "ocfs2.h"
27#include "ocfs2_lockingver.h"
28
29#include "alloc.h"
30#include "dcache.h"
31#include "dlmglue.h"
32#include "extent_map.h"
33#include "file.h"
34#include "heartbeat.h"
35#include "inode.h"
36#include "journal.h"
37#include "stackglue.h"
38#include "slot_map.h"
39#include "super.h"
40#include "uptodate.h"
41#include "quota.h"
42#include "refcounttree.h"
43#include "acl.h"
44
45#include "buffer_head_io.h"
46
47struct ocfs2_mask_waiter {
48 struct list_head mw_item;
49 int mw_status;
50 struct completion mw_complete;
51 unsigned long mw_mask;
52 unsigned long mw_goal;
53#ifdef CONFIG_OCFS2_FS_STATS
54 ktime_t mw_lock_start;
55#endif
56};
57
58static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
59static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
60static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
61static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
62
63/*
64 * Return value from ->downconvert_worker functions.
65 *
66 * These control the precise actions of ocfs2_unblock_lock()
67 * and ocfs2_process_blocked_lock()
68 *
69 */
70enum ocfs2_unblock_action {
71 UNBLOCK_CONTINUE = 0, /* Continue downconvert */
72 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire
73 * ->post_unlock callback */
74 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire
75 * ->post_unlock() callback. */
76};
77
78struct ocfs2_unblock_ctl {
79 int requeue;
80 enum ocfs2_unblock_action unblock_action;
81};
82
83/* Lockdep class keys */
84#ifdef CONFIG_DEBUG_LOCK_ALLOC
85static struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
86#endif
87
88static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
89 int new_level);
90static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
91
92static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
93 int blocking);
94
95static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
96 int blocking);
97
98static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
99 struct ocfs2_lock_res *lockres);
100
101static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
102
103static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
104 int new_level);
105static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
106 int blocking);
107
108#define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
109
110/* This aids in debugging situations where a bad LVB might be involved. */
111static void ocfs2_dump_meta_lvb_info(u64 level,
112 const char *function,
113 unsigned int line,
114 struct ocfs2_lock_res *lockres)
115{
116 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
117
118 mlog(level, "LVB information for %s (called from %s:%u):\n",
119 lockres->l_name, function, line);
120 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n",
121 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters),
122 be32_to_cpu(lvb->lvb_igeneration));
123 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
124 (unsigned long long)be64_to_cpu(lvb->lvb_isize),
125 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
126 be16_to_cpu(lvb->lvb_imode));
127 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
128 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
129 (long long)be64_to_cpu(lvb->lvb_iatime_packed),
130 (long long)be64_to_cpu(lvb->lvb_ictime_packed),
131 (long long)be64_to_cpu(lvb->lvb_imtime_packed),
132 be32_to_cpu(lvb->lvb_iattr));
133}
134
135
136/*
137 * OCFS2 Lock Resource Operations
138 *
139 * These fine tune the behavior of the generic dlmglue locking infrastructure.
140 *
141 * The most basic of lock types can point ->l_priv to their respective
142 * struct ocfs2_super and allow the default actions to manage things.
143 *
144 * Right now, each lock type also needs to implement an init function,
145 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
146 * should be called when the lock is no longer needed (i.e., object
147 * destruction time).
148 */
149struct ocfs2_lock_res_ops {
150 /*
151 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
152 * this callback if ->l_priv is not an ocfs2_super pointer
153 */
154 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
155
156 /*
157 * Optionally called in the downconvert thread after a
158 * successful downconvert. The lockres will not be referenced
159 * after this callback is called, so it is safe to free
160 * memory, etc.
161 *
162 * The exact semantics of when this is called are controlled
163 * by ->downconvert_worker()
164 */
165 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
166
167 /*
168 * Allow a lock type to add checks to determine whether it is
169 * safe to downconvert a lock. Return 0 to re-queue the
170 * downconvert at a later time, nonzero to continue.
171 *
172 * For most locks, the default checks that there are no
173 * incompatible holders are sufficient.
174 *
175 * Called with the lockres spinlock held.
176 */
177 int (*check_downconvert)(struct ocfs2_lock_res *, int);
178
179 /*
180 * Allows a lock type to populate the lock value block. This
181 * is called on downconvert, and when we drop a lock.
182 *
183 * Locks that want to use this should set LOCK_TYPE_USES_LVB
184 * in the flags field.
185 *
186 * Called with the lockres spinlock held.
187 */
188 void (*set_lvb)(struct ocfs2_lock_res *);
189
190 /*
191 * Called from the downconvert thread when it is determined
192 * that a lock will be downconverted. This is called without
193 * any locks held so the function can do work that might
194 * schedule (syncing out data, etc).
195 *
196 * This should return any one of the ocfs2_unblock_action
197 * values, depending on what it wants the thread to do.
198 */
199 int (*downconvert_worker)(struct ocfs2_lock_res *, int);
200
201 /*
202 * LOCK_TYPE_* flags which describe the specific requirements
203 * of a lock type. Descriptions of each individual flag follow.
204 */
205 int flags;
206};
207
208/*
209 * Some locks want to "refresh" potentially stale data when a
210 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this
211 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the
212 * individual lockres l_flags member from the ast function. It is
213 * expected that the locking wrapper will clear the
214 * OCFS2_LOCK_NEEDS_REFRESH flag when done.
215 */
216#define LOCK_TYPE_REQUIRES_REFRESH 0x1
217
218/*
219 * Indicate that a lock type makes use of the lock value block. The
220 * ->set_lvb lock type callback must be defined.
221 */
222#define LOCK_TYPE_USES_LVB 0x2
223
224static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
225 .get_osb = ocfs2_get_inode_osb,
226 .flags = 0,
227};
228
229static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
230 .get_osb = ocfs2_get_inode_osb,
231 .check_downconvert = ocfs2_check_meta_downconvert,
232 .set_lvb = ocfs2_set_meta_lvb,
233 .downconvert_worker = ocfs2_data_convert_worker,
234 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
235};
236
237static struct ocfs2_lock_res_ops ocfs2_super_lops = {
238 .flags = LOCK_TYPE_REQUIRES_REFRESH,
239};
240
241static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
242 .flags = 0,
243};
244
245static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
246 .flags = 0,
247};
248
249static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
250 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
251};
252
253static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
254 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
255};
256
257static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
258 .get_osb = ocfs2_get_dentry_osb,
259 .post_unlock = ocfs2_dentry_post_unlock,
260 .downconvert_worker = ocfs2_dentry_convert_worker,
261 .flags = 0,
262};
263
264static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
265 .get_osb = ocfs2_get_inode_osb,
266 .flags = 0,
267};
268
269static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
270 .get_osb = ocfs2_get_file_osb,
271 .flags = 0,
272};
273
274static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
275 .set_lvb = ocfs2_set_qinfo_lvb,
276 .get_osb = ocfs2_get_qinfo_osb,
277 .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
278};
279
280static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
281 .check_downconvert = ocfs2_check_refcount_downconvert,
282 .downconvert_worker = ocfs2_refcount_convert_worker,
283 .flags = 0,
284};
285
286static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
287{
288 return lockres->l_type == OCFS2_LOCK_TYPE_META ||
289 lockres->l_type == OCFS2_LOCK_TYPE_RW ||
290 lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
291}
292
293static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb)
294{
295 return container_of(lksb, struct ocfs2_lock_res, l_lksb);
296}
297
298static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
299{
300 BUG_ON(!ocfs2_is_inode_lock(lockres));
301
302 return (struct inode *) lockres->l_priv;
303}
304
305static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
306{
307 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
308
309 return (struct ocfs2_dentry_lock *)lockres->l_priv;
310}
311
312static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
313{
314 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
315
316 return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
317}
318
319static inline struct ocfs2_refcount_tree *
320ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res)
321{
322 return container_of(res, struct ocfs2_refcount_tree, rf_lockres);
323}
324
325static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
326{
327 if (lockres->l_ops->get_osb)
328 return lockres->l_ops->get_osb(lockres);
329
330 return (struct ocfs2_super *)lockres->l_priv;
331}
332
333static int ocfs2_lock_create(struct ocfs2_super *osb,
334 struct ocfs2_lock_res *lockres,
335 int level,
336 u32 dlm_flags);
337static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
338 int wanted);
339static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
340 struct ocfs2_lock_res *lockres,
341 int level, unsigned long caller_ip);
342static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb,
343 struct ocfs2_lock_res *lockres,
344 int level)
345{
346 __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_);
347}
348
349static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
350static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
351static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
352static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
353static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
354 struct ocfs2_lock_res *lockres);
355static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
356 int convert);
357#define ocfs2_log_dlm_error(_func, _err, _lockres) do { \
358 if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \
359 mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \
360 _err, _func, _lockres->l_name); \
361 else \
362 mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \
363 _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \
364 (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \
365} while (0)
366static int ocfs2_downconvert_thread(void *arg);
367static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
368 struct ocfs2_lock_res *lockres);
369static int ocfs2_inode_lock_update(struct inode *inode,
370 struct buffer_head **bh);
371static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
372static inline int ocfs2_highest_compat_lock_level(int level);
373static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
374 int new_level);
375static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
376 struct ocfs2_lock_res *lockres,
377 int new_level,
378 int lvb,
379 unsigned int generation);
380static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
381 struct ocfs2_lock_res *lockres);
382static int ocfs2_cancel_convert(struct ocfs2_super *osb,
383 struct ocfs2_lock_res *lockres);
384
385
386static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
387 u64 blkno,
388 u32 generation,
389 char *name)
390{
391 int len;
392
393 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
394
395 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
396 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
397 (long long)blkno, generation);
398
399 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
400
401 mlog(0, "built lock resource with name: %s\n", name);
402}
403
404static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
405
406static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
407 struct ocfs2_dlm_debug *dlm_debug)
408{
409 mlog(0, "Add tracking for lockres %s\n", res->l_name);
410
411 spin_lock(&ocfs2_dlm_tracking_lock);
412 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
413 spin_unlock(&ocfs2_dlm_tracking_lock);
414}
415
416static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
417{
418 spin_lock(&ocfs2_dlm_tracking_lock);
419 if (!list_empty(&res->l_debug_list))
420 list_del_init(&res->l_debug_list);
421 spin_unlock(&ocfs2_dlm_tracking_lock);
422}
423
424#ifdef CONFIG_OCFS2_FS_STATS
425static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
426{
427 res->l_lock_refresh = 0;
428 res->l_lock_wait = 0;
429 memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats));
430 memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats));
431}
432
433static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level,
434 struct ocfs2_mask_waiter *mw, int ret)
435{
436 u32 usec;
437 ktime_t kt;
438 struct ocfs2_lock_stats *stats;
439
440 if (level == LKM_PRMODE)
441 stats = &res->l_lock_prmode;
442 else if (level == LKM_EXMODE)
443 stats = &res->l_lock_exmode;
444 else
445 return;
446
447 kt = ktime_sub(ktime_get(), mw->mw_lock_start);
448 usec = ktime_to_us(kt);
449
450 stats->ls_gets++;
451 stats->ls_total += ktime_to_ns(kt);
452 /* overflow */
453 if (unlikely(stats->ls_gets == 0)) {
454 stats->ls_gets++;
455 stats->ls_total = ktime_to_ns(kt);
456 }
457
458 if (stats->ls_max < usec)
459 stats->ls_max = usec;
460
461 if (ret)
462 stats->ls_fail++;
463
464 stats->ls_last = ktime_to_us(ktime_get_real());
465}
466
467static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
468{
469 lockres->l_lock_refresh++;
470}
471
472static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres)
473{
474 struct ocfs2_mask_waiter *mw;
475
476 if (list_empty(&lockres->l_mask_waiters)) {
477 lockres->l_lock_wait = 0;
478 return;
479 }
480
481 mw = list_first_entry(&lockres->l_mask_waiters,
482 struct ocfs2_mask_waiter, mw_item);
483 lockres->l_lock_wait =
484 ktime_to_us(ktime_mono_to_real(mw->mw_lock_start));
485}
486
487static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
488{
489 mw->mw_lock_start = ktime_get();
490}
491#else
492static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
493{
494}
495static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res,
496 int level, struct ocfs2_mask_waiter *mw, int ret)
497{
498}
499static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
500{
501}
502static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres)
503{
504}
505static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
506{
507}
508#endif
509
510static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
511 struct ocfs2_lock_res *res,
512 enum ocfs2_lock_type type,
513 struct ocfs2_lock_res_ops *ops,
514 void *priv)
515{
516 res->l_type = type;
517 res->l_ops = ops;
518 res->l_priv = priv;
519
520 res->l_level = DLM_LOCK_IV;
521 res->l_requested = DLM_LOCK_IV;
522 res->l_blocking = DLM_LOCK_IV;
523 res->l_action = OCFS2_AST_INVALID;
524 res->l_unlock_action = OCFS2_UNLOCK_INVALID;
525
526 res->l_flags = OCFS2_LOCK_INITIALIZED;
527
528 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
529
530 ocfs2_init_lock_stats(res);
531#ifdef CONFIG_DEBUG_LOCK_ALLOC
532 if (type != OCFS2_LOCK_TYPE_OPEN)
533 lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type],
534 &lockdep_keys[type], 0);
535 else
536 res->l_lockdep_map.key = NULL;
537#endif
538}
539
540void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
541{
542 /* This also clears out the lock status block */
543 memset(res, 0, sizeof(struct ocfs2_lock_res));
544 spin_lock_init(&res->l_lock);
545 init_waitqueue_head(&res->l_event);
546 INIT_LIST_HEAD(&res->l_blocked_list);
547 INIT_LIST_HEAD(&res->l_mask_waiters);
548 INIT_LIST_HEAD(&res->l_holders);
549}
550
551void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
552 enum ocfs2_lock_type type,
553 unsigned int generation,
554 struct inode *inode)
555{
556 struct ocfs2_lock_res_ops *ops;
557
558 switch(type) {
559 case OCFS2_LOCK_TYPE_RW:
560 ops = &ocfs2_inode_rw_lops;
561 break;
562 case OCFS2_LOCK_TYPE_META:
563 ops = &ocfs2_inode_inode_lops;
564 break;
565 case OCFS2_LOCK_TYPE_OPEN:
566 ops = &ocfs2_inode_open_lops;
567 break;
568 default:
569 mlog_bug_on_msg(1, "type: %d\n", type);
570 ops = NULL; /* thanks, gcc */
571 break;
572 }
573
574 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
575 generation, res->l_name);
576 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
577}
578
579static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
580{
581 struct inode *inode = ocfs2_lock_res_inode(lockres);
582
583 return OCFS2_SB(inode->i_sb);
584}
585
586static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
587{
588 struct ocfs2_mem_dqinfo *info = lockres->l_priv;
589
590 return OCFS2_SB(info->dqi_gi.dqi_sb);
591}
592
593static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
594{
595 struct ocfs2_file_private *fp = lockres->l_priv;
596
597 return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
598}
599
600static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
601{
602 __be64 inode_blkno_be;
603
604 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
605 sizeof(__be64));
606
607 return be64_to_cpu(inode_blkno_be);
608}
609
610static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
611{
612 struct ocfs2_dentry_lock *dl = lockres->l_priv;
613
614 return OCFS2_SB(dl->dl_inode->i_sb);
615}
616
617void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
618 u64 parent, struct inode *inode)
619{
620 int len;
621 u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
622 __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
623 struct ocfs2_lock_res *lockres = &dl->dl_lockres;
624
625 ocfs2_lock_res_init_once(lockres);
626
627 /*
628 * Unfortunately, the standard lock naming scheme won't work
629 * here because we have two 16 byte values to use. Instead,
630 * we'll stuff the inode number as a binary value. We still
631 * want error prints to show something without garbling the
632 * display, so drop a null byte in there before the inode
633 * number. A future version of OCFS2 will likely use all
634 * binary lock names. The stringified names have been a
635 * tremendous aid in debugging, but now that the debugfs
636 * interface exists, we can mangle things there if need be.
637 *
638 * NOTE: We also drop the standard "pad" value (the total lock
639 * name size stays the same though - the last part is all
640 * zeros due to the memset in ocfs2_lock_res_init_once()
641 */
642 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
643 "%c%016llx",
644 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
645 (long long)parent);
646
647 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
648
649 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
650 sizeof(__be64));
651
652 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
653 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
654 dl);
655}
656
657static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
658 struct ocfs2_super *osb)
659{
660 /* Superblock lockres doesn't come from a slab so we call init
661 * once on it manually. */
662 ocfs2_lock_res_init_once(res);
663 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
664 0, res->l_name);
665 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
666 &ocfs2_super_lops, osb);
667}
668
669static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
670 struct ocfs2_super *osb)
671{
672 /* Rename lockres doesn't come from a slab so we call init
673 * once on it manually. */
674 ocfs2_lock_res_init_once(res);
675 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
676 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
677 &ocfs2_rename_lops, osb);
678}
679
680static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
681 struct ocfs2_super *osb)
682{
683 /* nfs_sync lockres doesn't come from a slab so we call init
684 * once on it manually. */
685 ocfs2_lock_res_init_once(res);
686 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
687 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
688 &ocfs2_nfs_sync_lops, osb);
689}
690
691static void ocfs2_nfs_sync_lock_init(struct ocfs2_super *osb)
692{
693 ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
694 init_rwsem(&osb->nfs_sync_rwlock);
695}
696
697void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb)
698{
699 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
700
701 /* Only one trimfs thread are allowed to work at the same time. */
702 mutex_lock(&osb->obs_trim_fs_mutex);
703
704 ocfs2_lock_res_init_once(lockres);
705 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name);
706 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS,
707 &ocfs2_trim_fs_lops, osb);
708}
709
710void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb)
711{
712 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
713
714 ocfs2_simple_drop_lockres(osb, lockres);
715 ocfs2_lock_res_free(lockres);
716
717 mutex_unlock(&osb->obs_trim_fs_mutex);
718}
719
720static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
721 struct ocfs2_super *osb)
722{
723 ocfs2_lock_res_init_once(res);
724 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
725 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
726 &ocfs2_orphan_scan_lops, osb);
727}
728
729void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
730 struct ocfs2_file_private *fp)
731{
732 struct inode *inode = fp->fp_file->f_mapping->host;
733 struct ocfs2_inode_info *oi = OCFS2_I(inode);
734
735 ocfs2_lock_res_init_once(lockres);
736 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
737 inode->i_generation, lockres->l_name);
738 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
739 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
740 fp);
741 lockres->l_flags |= OCFS2_LOCK_NOCACHE;
742}
743
744void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
745 struct ocfs2_mem_dqinfo *info)
746{
747 ocfs2_lock_res_init_once(lockres);
748 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
749 0, lockres->l_name);
750 ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
751 OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
752 info);
753}
754
755void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
756 struct ocfs2_super *osb, u64 ref_blkno,
757 unsigned int generation)
758{
759 ocfs2_lock_res_init_once(lockres);
760 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno,
761 generation, lockres->l_name);
762 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT,
763 &ocfs2_refcount_block_lops, osb);
764}
765
766void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
767{
768 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
769 return;
770
771 ocfs2_remove_lockres_tracking(res);
772
773 mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
774 "Lockres %s is on the blocked list\n",
775 res->l_name);
776 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
777 "Lockres %s has mask waiters pending\n",
778 res->l_name);
779 mlog_bug_on_msg(spin_is_locked(&res->l_lock),
780 "Lockres %s is locked\n",
781 res->l_name);
782 mlog_bug_on_msg(res->l_ro_holders,
783 "Lockres %s has %u ro holders\n",
784 res->l_name, res->l_ro_holders);
785 mlog_bug_on_msg(res->l_ex_holders,
786 "Lockres %s has %u ex holders\n",
787 res->l_name, res->l_ex_holders);
788
789 /* Need to clear out the lock status block for the dlm */
790 memset(&res->l_lksb, 0, sizeof(res->l_lksb));
791
792 res->l_flags = 0UL;
793}
794
795/*
796 * Keep a list of processes who have interest in a lockres.
797 * Note: this is now only uesed for check recursive cluster locking.
798 */
799static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres,
800 struct ocfs2_lock_holder *oh)
801{
802 INIT_LIST_HEAD(&oh->oh_list);
803 oh->oh_owner_pid = get_pid(task_pid(current));
804
805 spin_lock(&lockres->l_lock);
806 list_add_tail(&oh->oh_list, &lockres->l_holders);
807 spin_unlock(&lockres->l_lock);
808}
809
810static struct ocfs2_lock_holder *
811ocfs2_pid_holder(struct ocfs2_lock_res *lockres,
812 struct pid *pid)
813{
814 struct ocfs2_lock_holder *oh;
815
816 spin_lock(&lockres->l_lock);
817 list_for_each_entry(oh, &lockres->l_holders, oh_list) {
818 if (oh->oh_owner_pid == pid) {
819 spin_unlock(&lockres->l_lock);
820 return oh;
821 }
822 }
823 spin_unlock(&lockres->l_lock);
824 return NULL;
825}
826
827static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres,
828 struct ocfs2_lock_holder *oh)
829{
830 spin_lock(&lockres->l_lock);
831 list_del(&oh->oh_list);
832 spin_unlock(&lockres->l_lock);
833
834 put_pid(oh->oh_owner_pid);
835}
836
837
838static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
839 int level)
840{
841 BUG_ON(!lockres);
842
843 switch(level) {
844 case DLM_LOCK_EX:
845 lockres->l_ex_holders++;
846 break;
847 case DLM_LOCK_PR:
848 lockres->l_ro_holders++;
849 break;
850 default:
851 BUG();
852 }
853}
854
855static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
856 int level)
857{
858 BUG_ON(!lockres);
859
860 switch(level) {
861 case DLM_LOCK_EX:
862 BUG_ON(!lockres->l_ex_holders);
863 lockres->l_ex_holders--;
864 break;
865 case DLM_LOCK_PR:
866 BUG_ON(!lockres->l_ro_holders);
867 lockres->l_ro_holders--;
868 break;
869 default:
870 BUG();
871 }
872}
873
874/* WARNING: This function lives in a world where the only three lock
875 * levels are EX, PR, and NL. It *will* have to be adjusted when more
876 * lock types are added. */
877static inline int ocfs2_highest_compat_lock_level(int level)
878{
879 int new_level = DLM_LOCK_EX;
880
881 if (level == DLM_LOCK_EX)
882 new_level = DLM_LOCK_NL;
883 else if (level == DLM_LOCK_PR)
884 new_level = DLM_LOCK_PR;
885 return new_level;
886}
887
888static void lockres_set_flags(struct ocfs2_lock_res *lockres,
889 unsigned long newflags)
890{
891 struct ocfs2_mask_waiter *mw, *tmp;
892
893 assert_spin_locked(&lockres->l_lock);
894
895 lockres->l_flags = newflags;
896
897 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
898 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
899 continue;
900
901 list_del_init(&mw->mw_item);
902 mw->mw_status = 0;
903 complete(&mw->mw_complete);
904 ocfs2_track_lock_wait(lockres);
905 }
906}
907static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
908{
909 lockres_set_flags(lockres, lockres->l_flags | or);
910}
911static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
912 unsigned long clear)
913{
914 lockres_set_flags(lockres, lockres->l_flags & ~clear);
915}
916
917static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
918{
919 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
920 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
921 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
922 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
923
924 lockres->l_level = lockres->l_requested;
925 if (lockres->l_level <=
926 ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
927 lockres->l_blocking = DLM_LOCK_NL;
928 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
929 }
930 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
931}
932
933static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
934{
935 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
936 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
937
938 /* Convert from RO to EX doesn't really need anything as our
939 * information is already up to data. Convert from NL to
940 * *anything* however should mark ourselves as needing an
941 * update */
942 if (lockres->l_level == DLM_LOCK_NL &&
943 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
944 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
945
946 lockres->l_level = lockres->l_requested;
947
948 /*
949 * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing
950 * the OCFS2_LOCK_BUSY flag to prevent the dc thread from
951 * downconverting the lock before the upconvert has fully completed.
952 * Do not prevent the dc thread from downconverting if NONBLOCK lock
953 * had already returned.
954 */
955 if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED))
956 lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
957 else
958 lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED);
959
960 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
961}
962
963static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
964{
965 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
966 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
967
968 if (lockres->l_requested > DLM_LOCK_NL &&
969 !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
970 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
971 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
972
973 lockres->l_level = lockres->l_requested;
974 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
975 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
976}
977
978static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
979 int level)
980{
981 int needs_downconvert = 0;
982
983 assert_spin_locked(&lockres->l_lock);
984
985 if (level > lockres->l_blocking) {
986 /* only schedule a downconvert if we haven't already scheduled
987 * one that goes low enough to satisfy the level we're
988 * blocking. this also catches the case where we get
989 * duplicate BASTs */
990 if (ocfs2_highest_compat_lock_level(level) <
991 ocfs2_highest_compat_lock_level(lockres->l_blocking))
992 needs_downconvert = 1;
993
994 lockres->l_blocking = level;
995 }
996
997 mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
998 lockres->l_name, level, lockres->l_level, lockres->l_blocking,
999 needs_downconvert);
1000
1001 if (needs_downconvert)
1002 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
1003 mlog(0, "needs_downconvert = %d\n", needs_downconvert);
1004 return needs_downconvert;
1005}
1006
1007/*
1008 * OCFS2_LOCK_PENDING and l_pending_gen.
1009 *
1010 * Why does OCFS2_LOCK_PENDING exist? To close a race between setting
1011 * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock()
1012 * for more details on the race.
1013 *
1014 * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces
1015 * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock()
1016 * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear
1017 * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns,
1018 * the caller is going to try to clear PENDING again. If nothing else is
1019 * happening, __lockres_clear_pending() sees PENDING is unset and does
1020 * nothing.
1021 *
1022 * But what if another path (eg downconvert thread) has just started a
1023 * new locking action? The other path has re-set PENDING. Our path
1024 * cannot clear PENDING, because that will re-open the original race
1025 * window.
1026 *
1027 * [Example]
1028 *
1029 * ocfs2_meta_lock()
1030 * ocfs2_cluster_lock()
1031 * set BUSY
1032 * set PENDING
1033 * drop l_lock
1034 * ocfs2_dlm_lock()
1035 * ocfs2_locking_ast() ocfs2_downconvert_thread()
1036 * clear PENDING ocfs2_unblock_lock()
1037 * take_l_lock
1038 * !BUSY
1039 * ocfs2_prepare_downconvert()
1040 * set BUSY
1041 * set PENDING
1042 * drop l_lock
1043 * take l_lock
1044 * clear PENDING
1045 * drop l_lock
1046 * <window>
1047 * ocfs2_dlm_lock()
1048 *
1049 * So as you can see, we now have a window where l_lock is not held,
1050 * PENDING is not set, and ocfs2_dlm_lock() has not been called.
1051 *
1052 * The core problem is that ocfs2_cluster_lock() has cleared the PENDING
1053 * set by ocfs2_prepare_downconvert(). That wasn't nice.
1054 *
1055 * To solve this we introduce l_pending_gen. A call to
1056 * lockres_clear_pending() will only do so when it is passed a generation
1057 * number that matches the lockres. lockres_set_pending() will return the
1058 * current generation number. When ocfs2_cluster_lock() goes to clear
1059 * PENDING, it passes the generation it got from set_pending(). In our
1060 * example above, the generation numbers will *not* match. Thus,
1061 * ocfs2_cluster_lock() will not clear the PENDING set by
1062 * ocfs2_prepare_downconvert().
1063 */
1064
1065/* Unlocked version for ocfs2_locking_ast() */
1066static void __lockres_clear_pending(struct ocfs2_lock_res *lockres,
1067 unsigned int generation,
1068 struct ocfs2_super *osb)
1069{
1070 assert_spin_locked(&lockres->l_lock);
1071
1072 /*
1073 * The ast and locking functions can race us here. The winner
1074 * will clear pending, the loser will not.
1075 */
1076 if (!(lockres->l_flags & OCFS2_LOCK_PENDING) ||
1077 (lockres->l_pending_gen != generation))
1078 return;
1079
1080 lockres_clear_flags(lockres, OCFS2_LOCK_PENDING);
1081 lockres->l_pending_gen++;
1082
1083 /*
1084 * The downconvert thread may have skipped us because we
1085 * were PENDING. Wake it up.
1086 */
1087 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1088 ocfs2_wake_downconvert_thread(osb);
1089}
1090
1091/* Locked version for callers of ocfs2_dlm_lock() */
1092static void lockres_clear_pending(struct ocfs2_lock_res *lockres,
1093 unsigned int generation,
1094 struct ocfs2_super *osb)
1095{
1096 unsigned long flags;
1097
1098 spin_lock_irqsave(&lockres->l_lock, flags);
1099 __lockres_clear_pending(lockres, generation, osb);
1100 spin_unlock_irqrestore(&lockres->l_lock, flags);
1101}
1102
1103static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
1104{
1105 assert_spin_locked(&lockres->l_lock);
1106 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
1107
1108 lockres_or_flags(lockres, OCFS2_LOCK_PENDING);
1109
1110 return lockres->l_pending_gen;
1111}
1112
1113static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
1114{
1115 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1116 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1117 int needs_downconvert;
1118 unsigned long flags;
1119
1120 BUG_ON(level <= DLM_LOCK_NL);
1121
1122 mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
1123 "type %s\n", lockres->l_name, level, lockres->l_level,
1124 ocfs2_lock_type_string(lockres->l_type));
1125
1126 /*
1127 * We can skip the bast for locks which don't enable caching -
1128 * they'll be dropped at the earliest possible time anyway.
1129 */
1130 if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
1131 return;
1132
1133 spin_lock_irqsave(&lockres->l_lock, flags);
1134 needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
1135 if (needs_downconvert)
1136 ocfs2_schedule_blocked_lock(osb, lockres);
1137 spin_unlock_irqrestore(&lockres->l_lock, flags);
1138
1139 wake_up(&lockres->l_event);
1140
1141 ocfs2_wake_downconvert_thread(osb);
1142}
1143
1144static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
1145{
1146 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1147 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1148 unsigned long flags;
1149 int status;
1150
1151 spin_lock_irqsave(&lockres->l_lock, flags);
1152
1153 status = ocfs2_dlm_lock_status(&lockres->l_lksb);
1154
1155 if (status == -EAGAIN) {
1156 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1157 goto out;
1158 }
1159
1160 if (status) {
1161 mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n",
1162 lockres->l_name, status);
1163 spin_unlock_irqrestore(&lockres->l_lock, flags);
1164 return;
1165 }
1166
1167 mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
1168 "level %d => %d\n", lockres->l_name, lockres->l_action,
1169 lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
1170
1171 switch(lockres->l_action) {
1172 case OCFS2_AST_ATTACH:
1173 ocfs2_generic_handle_attach_action(lockres);
1174 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
1175 break;
1176 case OCFS2_AST_CONVERT:
1177 ocfs2_generic_handle_convert_action(lockres);
1178 break;
1179 case OCFS2_AST_DOWNCONVERT:
1180 ocfs2_generic_handle_downconvert_action(lockres);
1181 break;
1182 default:
1183 mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
1184 "flags 0x%lx, unlock: %u\n",
1185 lockres->l_name, lockres->l_action, lockres->l_flags,
1186 lockres->l_unlock_action);
1187 BUG();
1188 }
1189out:
1190 /* set it to something invalid so if we get called again we
1191 * can catch it. */
1192 lockres->l_action = OCFS2_AST_INVALID;
1193
1194 /* Did we try to cancel this lock? Clear that state */
1195 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT)
1196 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1197
1198 /*
1199 * We may have beaten the locking functions here. We certainly
1200 * know that dlm_lock() has been called :-)
1201 * Because we can't have two lock calls in flight at once, we
1202 * can use lockres->l_pending_gen.
1203 */
1204 __lockres_clear_pending(lockres, lockres->l_pending_gen, osb);
1205
1206 wake_up(&lockres->l_event);
1207 spin_unlock_irqrestore(&lockres->l_lock, flags);
1208}
1209
1210static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
1211{
1212 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1213 unsigned long flags;
1214
1215 mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
1216 lockres->l_name, lockres->l_unlock_action);
1217
1218 spin_lock_irqsave(&lockres->l_lock, flags);
1219 if (error) {
1220 mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
1221 "unlock_action %d\n", error, lockres->l_name,
1222 lockres->l_unlock_action);
1223 spin_unlock_irqrestore(&lockres->l_lock, flags);
1224 return;
1225 }
1226
1227 switch(lockres->l_unlock_action) {
1228 case OCFS2_UNLOCK_CANCEL_CONVERT:
1229 mlog(0, "Cancel convert success for %s\n", lockres->l_name);
1230 lockres->l_action = OCFS2_AST_INVALID;
1231 /* Downconvert thread may have requeued this lock, we
1232 * need to wake it. */
1233 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1234 ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
1235 break;
1236 case OCFS2_UNLOCK_DROP_LOCK:
1237 lockres->l_level = DLM_LOCK_IV;
1238 break;
1239 default:
1240 BUG();
1241 }
1242
1243 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1244 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1245 wake_up(&lockres->l_event);
1246 spin_unlock_irqrestore(&lockres->l_lock, flags);
1247}
1248
1249/*
1250 * This is the filesystem locking protocol. It provides the lock handling
1251 * hooks for the underlying DLM. It has a maximum version number.
1252 * The version number allows interoperability with systems running at
1253 * the same major number and an equal or smaller minor number.
1254 *
1255 * Whenever the filesystem does new things with locks (adds or removes a
1256 * lock, orders them differently, does different things underneath a lock),
1257 * the version must be changed. The protocol is negotiated when joining
1258 * the dlm domain. A node may join the domain if its major version is
1259 * identical to all other nodes and its minor version is greater than
1260 * or equal to all other nodes. When its minor version is greater than
1261 * the other nodes, it will run at the minor version specified by the
1262 * other nodes.
1263 *
1264 * If a locking change is made that will not be compatible with older
1265 * versions, the major number must be increased and the minor version set
1266 * to zero. If a change merely adds a behavior that can be disabled when
1267 * speaking to older versions, the minor version must be increased. If a
1268 * change adds a fully backwards compatible change (eg, LVB changes that
1269 * are just ignored by older versions), the version does not need to be
1270 * updated.
1271 */
1272static struct ocfs2_locking_protocol lproto = {
1273 .lp_max_version = {
1274 .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
1275 .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
1276 },
1277 .lp_lock_ast = ocfs2_locking_ast,
1278 .lp_blocking_ast = ocfs2_blocking_ast,
1279 .lp_unlock_ast = ocfs2_unlock_ast,
1280};
1281
1282void ocfs2_set_locking_protocol(void)
1283{
1284 ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
1285}
1286
1287static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
1288 int convert)
1289{
1290 unsigned long flags;
1291
1292 spin_lock_irqsave(&lockres->l_lock, flags);
1293 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1294 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1295 if (convert)
1296 lockres->l_action = OCFS2_AST_INVALID;
1297 else
1298 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1299 spin_unlock_irqrestore(&lockres->l_lock, flags);
1300
1301 wake_up(&lockres->l_event);
1302}
1303
1304/* Note: If we detect another process working on the lock (i.e.,
1305 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
1306 * to do the right thing in that case.
1307 */
1308static int ocfs2_lock_create(struct ocfs2_super *osb,
1309 struct ocfs2_lock_res *lockres,
1310 int level,
1311 u32 dlm_flags)
1312{
1313 int ret = 0;
1314 unsigned long flags;
1315 unsigned int gen;
1316
1317 mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level,
1318 dlm_flags);
1319
1320 spin_lock_irqsave(&lockres->l_lock, flags);
1321 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
1322 (lockres->l_flags & OCFS2_LOCK_BUSY)) {
1323 spin_unlock_irqrestore(&lockres->l_lock, flags);
1324 goto bail;
1325 }
1326
1327 lockres->l_action = OCFS2_AST_ATTACH;
1328 lockres->l_requested = level;
1329 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1330 gen = lockres_set_pending(lockres);
1331 spin_unlock_irqrestore(&lockres->l_lock, flags);
1332
1333 ret = ocfs2_dlm_lock(osb->cconn,
1334 level,
1335 &lockres->l_lksb,
1336 dlm_flags,
1337 lockres->l_name,
1338 OCFS2_LOCK_ID_MAX_LEN - 1);
1339 lockres_clear_pending(lockres, gen, osb);
1340 if (ret) {
1341 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
1342 ocfs2_recover_from_dlm_error(lockres, 1);
1343 }
1344
1345 mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name);
1346
1347bail:
1348 return ret;
1349}
1350
1351static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
1352 int flag)
1353{
1354 unsigned long flags;
1355 int ret;
1356
1357 spin_lock_irqsave(&lockres->l_lock, flags);
1358 ret = lockres->l_flags & flag;
1359 spin_unlock_irqrestore(&lockres->l_lock, flags);
1360
1361 return ret;
1362}
1363
1364static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
1365
1366{
1367 wait_event(lockres->l_event,
1368 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
1369}
1370
1371static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
1372
1373{
1374 wait_event(lockres->l_event,
1375 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
1376}
1377
1378/* predict what lock level we'll be dropping down to on behalf
1379 * of another node, and return true if the currently wanted
1380 * level will be compatible with it. */
1381static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
1382 int wanted)
1383{
1384 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
1385
1386 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
1387}
1388
1389static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
1390{
1391 INIT_LIST_HEAD(&mw->mw_item);
1392 init_completion(&mw->mw_complete);
1393 ocfs2_init_start_time(mw);
1394}
1395
1396static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
1397{
1398 wait_for_completion(&mw->mw_complete);
1399 /* Re-arm the completion in case we want to wait on it again */
1400 reinit_completion(&mw->mw_complete);
1401 return mw->mw_status;
1402}
1403
1404static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
1405 struct ocfs2_mask_waiter *mw,
1406 unsigned long mask,
1407 unsigned long goal)
1408{
1409 BUG_ON(!list_empty(&mw->mw_item));
1410
1411 assert_spin_locked(&lockres->l_lock);
1412
1413 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
1414 mw->mw_mask = mask;
1415 mw->mw_goal = goal;
1416 ocfs2_track_lock_wait(lockres);
1417}
1418
1419/* returns 0 if the mw that was removed was already satisfied, -EBUSY
1420 * if the mask still hadn't reached its goal */
1421static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1422 struct ocfs2_mask_waiter *mw)
1423{
1424 int ret = 0;
1425
1426 assert_spin_locked(&lockres->l_lock);
1427 if (!list_empty(&mw->mw_item)) {
1428 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
1429 ret = -EBUSY;
1430
1431 list_del_init(&mw->mw_item);
1432 init_completion(&mw->mw_complete);
1433 ocfs2_track_lock_wait(lockres);
1434 }
1435
1436 return ret;
1437}
1438
1439static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1440 struct ocfs2_mask_waiter *mw)
1441{
1442 unsigned long flags;
1443 int ret = 0;
1444
1445 spin_lock_irqsave(&lockres->l_lock, flags);
1446 ret = __lockres_remove_mask_waiter(lockres, mw);
1447 spin_unlock_irqrestore(&lockres->l_lock, flags);
1448
1449 return ret;
1450
1451}
1452
1453static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
1454 struct ocfs2_lock_res *lockres)
1455{
1456 int ret;
1457
1458 ret = wait_for_completion_interruptible(&mw->mw_complete);
1459 if (ret)
1460 lockres_remove_mask_waiter(lockres, mw);
1461 else
1462 ret = mw->mw_status;
1463 /* Re-arm the completion in case we want to wait on it again */
1464 reinit_completion(&mw->mw_complete);
1465 return ret;
1466}
1467
1468static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
1469 struct ocfs2_lock_res *lockres,
1470 int level,
1471 u32 lkm_flags,
1472 int arg_flags,
1473 int l_subclass,
1474 unsigned long caller_ip)
1475{
1476 struct ocfs2_mask_waiter mw;
1477 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
1478 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
1479 unsigned long flags;
1480 unsigned int gen;
1481 int noqueue_attempted = 0;
1482 int dlm_locked = 0;
1483 int kick_dc = 0;
1484
1485 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
1486 mlog_errno(-EINVAL);
1487 return -EINVAL;
1488 }
1489
1490 ocfs2_init_mask_waiter(&mw);
1491
1492 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
1493 lkm_flags |= DLM_LKF_VALBLK;
1494
1495again:
1496 wait = 0;
1497
1498 spin_lock_irqsave(&lockres->l_lock, flags);
1499
1500 if (catch_signals && signal_pending(current)) {
1501 ret = -ERESTARTSYS;
1502 goto unlock;
1503 }
1504
1505 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
1506 "Cluster lock called on freeing lockres %s! flags "
1507 "0x%lx\n", lockres->l_name, lockres->l_flags);
1508
1509 /* We only compare against the currently granted level
1510 * here. If the lock is blocked waiting on a downconvert,
1511 * we'll get caught below. */
1512 if (lockres->l_flags & OCFS2_LOCK_BUSY &&
1513 level > lockres->l_level) {
1514 /* is someone sitting in dlm_lock? If so, wait on
1515 * them. */
1516 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1517 wait = 1;
1518 goto unlock;
1519 }
1520
1521 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) {
1522 /*
1523 * We've upconverted. If the lock now has a level we can
1524 * work with, we take it. If, however, the lock is not at the
1525 * required level, we go thru the full cycle. One way this could
1526 * happen is if a process requesting an upconvert to PR is
1527 * closely followed by another requesting upconvert to an EX.
1528 * If the process requesting EX lands here, we want it to
1529 * continue attempting to upconvert and let the process
1530 * requesting PR take the lock.
1531 * If multiple processes request upconvert to PR, the first one
1532 * here will take the lock. The others will have to go thru the
1533 * OCFS2_LOCK_BLOCKED check to ensure that there is no pending
1534 * downconvert request.
1535 */
1536 if (level <= lockres->l_level)
1537 goto update_holders;
1538 }
1539
1540 if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
1541 !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
1542 /* is the lock is currently blocked on behalf of
1543 * another node */
1544 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
1545 wait = 1;
1546 goto unlock;
1547 }
1548
1549 if (level > lockres->l_level) {
1550 if (noqueue_attempted > 0) {
1551 ret = -EAGAIN;
1552 goto unlock;
1553 }
1554 if (lkm_flags & DLM_LKF_NOQUEUE)
1555 noqueue_attempted = 1;
1556
1557 if (lockres->l_action != OCFS2_AST_INVALID)
1558 mlog(ML_ERROR, "lockres %s has action %u pending\n",
1559 lockres->l_name, lockres->l_action);
1560
1561 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1562 lockres->l_action = OCFS2_AST_ATTACH;
1563 lkm_flags &= ~DLM_LKF_CONVERT;
1564 } else {
1565 lockres->l_action = OCFS2_AST_CONVERT;
1566 lkm_flags |= DLM_LKF_CONVERT;
1567 }
1568
1569 lockres->l_requested = level;
1570 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1571 gen = lockres_set_pending(lockres);
1572 spin_unlock_irqrestore(&lockres->l_lock, flags);
1573
1574 BUG_ON(level == DLM_LOCK_IV);
1575 BUG_ON(level == DLM_LOCK_NL);
1576
1577 mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
1578 lockres->l_name, lockres->l_level, level);
1579
1580 /* call dlm_lock to upgrade lock now */
1581 ret = ocfs2_dlm_lock(osb->cconn,
1582 level,
1583 &lockres->l_lksb,
1584 lkm_flags,
1585 lockres->l_name,
1586 OCFS2_LOCK_ID_MAX_LEN - 1);
1587 lockres_clear_pending(lockres, gen, osb);
1588 if (ret) {
1589 if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
1590 (ret != -EAGAIN)) {
1591 ocfs2_log_dlm_error("ocfs2_dlm_lock",
1592 ret, lockres);
1593 }
1594 ocfs2_recover_from_dlm_error(lockres, 1);
1595 goto out;
1596 }
1597 dlm_locked = 1;
1598
1599 mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n",
1600 lockres->l_name);
1601
1602 /* At this point we've gone inside the dlm and need to
1603 * complete our work regardless. */
1604 catch_signals = 0;
1605
1606 /* wait for busy to clear and carry on */
1607 goto again;
1608 }
1609
1610update_holders:
1611 /* Ok, if we get here then we're good to go. */
1612 ocfs2_inc_holders(lockres, level);
1613
1614 ret = 0;
1615unlock:
1616 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1617
1618 /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */
1619 kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED);
1620
1621 spin_unlock_irqrestore(&lockres->l_lock, flags);
1622 if (kick_dc)
1623 ocfs2_wake_downconvert_thread(osb);
1624out:
1625 /*
1626 * This is helping work around a lock inversion between the page lock
1627 * and dlm locks. One path holds the page lock while calling aops
1628 * which block acquiring dlm locks. The voting thread holds dlm
1629 * locks while acquiring page locks while down converting data locks.
1630 * This block is helping an aop path notice the inversion and back
1631 * off to unlock its page lock before trying the dlm lock again.
1632 */
1633 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
1634 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
1635 wait = 0;
1636 spin_lock_irqsave(&lockres->l_lock, flags);
1637 if (__lockres_remove_mask_waiter(lockres, &mw)) {
1638 if (dlm_locked)
1639 lockres_or_flags(lockres,
1640 OCFS2_LOCK_NONBLOCK_FINISHED);
1641 spin_unlock_irqrestore(&lockres->l_lock, flags);
1642 ret = -EAGAIN;
1643 } else {
1644 spin_unlock_irqrestore(&lockres->l_lock, flags);
1645 goto again;
1646 }
1647 }
1648 if (wait) {
1649 ret = ocfs2_wait_for_mask(&mw);
1650 if (ret == 0)
1651 goto again;
1652 mlog_errno(ret);
1653 }
1654 ocfs2_update_lock_stats(lockres, level, &mw, ret);
1655
1656#ifdef CONFIG_DEBUG_LOCK_ALLOC
1657 if (!ret && lockres->l_lockdep_map.key != NULL) {
1658 if (level == DLM_LOCK_PR)
1659 rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass,
1660 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1661 caller_ip);
1662 else
1663 rwsem_acquire(&lockres->l_lockdep_map, l_subclass,
1664 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1665 caller_ip);
1666 }
1667#endif
1668 return ret;
1669}
1670
1671static inline int ocfs2_cluster_lock(struct ocfs2_super *osb,
1672 struct ocfs2_lock_res *lockres,
1673 int level,
1674 u32 lkm_flags,
1675 int arg_flags)
1676{
1677 return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags,
1678 0, _RET_IP_);
1679}
1680
1681
1682static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
1683 struct ocfs2_lock_res *lockres,
1684 int level,
1685 unsigned long caller_ip)
1686{
1687 unsigned long flags;
1688
1689 spin_lock_irqsave(&lockres->l_lock, flags);
1690 ocfs2_dec_holders(lockres, level);
1691 ocfs2_downconvert_on_unlock(osb, lockres);
1692 spin_unlock_irqrestore(&lockres->l_lock, flags);
1693#ifdef CONFIG_DEBUG_LOCK_ALLOC
1694 if (lockres->l_lockdep_map.key != NULL)
1695 rwsem_release(&lockres->l_lockdep_map, caller_ip);
1696#endif
1697}
1698
1699static int ocfs2_create_new_lock(struct ocfs2_super *osb,
1700 struct ocfs2_lock_res *lockres,
1701 int ex,
1702 int local)
1703{
1704 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1705 unsigned long flags;
1706 u32 lkm_flags = local ? DLM_LKF_LOCAL : 0;
1707
1708 spin_lock_irqsave(&lockres->l_lock, flags);
1709 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
1710 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
1711 spin_unlock_irqrestore(&lockres->l_lock, flags);
1712
1713 return ocfs2_lock_create(osb, lockres, level, lkm_flags);
1714}
1715
1716/* Grants us an EX lock on the data and metadata resources, skipping
1717 * the normal cluster directory lookup. Use this ONLY on newly created
1718 * inodes which other nodes can't possibly see, and which haven't been
1719 * hashed in the inode hash yet. This can give us a good performance
1720 * increase as it'll skip the network broadcast normally associated
1721 * with creating a new lock resource. */
1722int ocfs2_create_new_inode_locks(struct inode *inode)
1723{
1724 int ret;
1725 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1726
1727 BUG_ON(!ocfs2_inode_is_new(inode));
1728
1729 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
1730
1731 /* NOTE: That we don't increment any of the holder counts, nor
1732 * do we add anything to a journal handle. Since this is
1733 * supposed to be a new inode which the cluster doesn't know
1734 * about yet, there is no need to. As far as the LVB handling
1735 * is concerned, this is basically like acquiring an EX lock
1736 * on a resource which has an invalid one -- we'll set it
1737 * valid when we release the EX. */
1738
1739 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
1740 if (ret) {
1741 mlog_errno(ret);
1742 goto bail;
1743 }
1744
1745 /*
1746 * We don't want to use DLM_LKF_LOCAL on a meta data lock as they
1747 * don't use a generation in their lock names.
1748 */
1749 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
1750 if (ret) {
1751 mlog_errno(ret);
1752 goto bail;
1753 }
1754
1755 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
1756 if (ret)
1757 mlog_errno(ret);
1758
1759bail:
1760 return ret;
1761}
1762
1763int ocfs2_rw_lock(struct inode *inode, int write)
1764{
1765 int status, level;
1766 struct ocfs2_lock_res *lockres;
1767 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1768
1769 mlog(0, "inode %llu take %s RW lock\n",
1770 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1771 write ? "EXMODE" : "PRMODE");
1772
1773 if (ocfs2_mount_local(osb))
1774 return 0;
1775
1776 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1777
1778 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1779
1780 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
1781 if (status < 0)
1782 mlog_errno(status);
1783
1784 return status;
1785}
1786
1787int ocfs2_try_rw_lock(struct inode *inode, int write)
1788{
1789 int status, level;
1790 struct ocfs2_lock_res *lockres;
1791 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1792
1793 mlog(0, "inode %llu try to take %s RW lock\n",
1794 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1795 write ? "EXMODE" : "PRMODE");
1796
1797 if (ocfs2_mount_local(osb))
1798 return 0;
1799
1800 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1801
1802 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1803
1804 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0);
1805 return status;
1806}
1807
1808void ocfs2_rw_unlock(struct inode *inode, int write)
1809{
1810 int level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1811 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
1812 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1813
1814 mlog(0, "inode %llu drop %s RW lock\n",
1815 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1816 write ? "EXMODE" : "PRMODE");
1817
1818 if (!ocfs2_mount_local(osb))
1819 ocfs2_cluster_unlock(osb, lockres, level);
1820}
1821
1822/*
1823 * ocfs2_open_lock always get PR mode lock.
1824 */
1825int ocfs2_open_lock(struct inode *inode)
1826{
1827 int status = 0;
1828 struct ocfs2_lock_res *lockres;
1829 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1830
1831 mlog(0, "inode %llu take PRMODE open lock\n",
1832 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1833
1834 if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb))
1835 goto out;
1836
1837 lockres = &OCFS2_I(inode)->ip_open_lockres;
1838
1839 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_PR, 0, 0);
1840 if (status < 0)
1841 mlog_errno(status);
1842
1843out:
1844 return status;
1845}
1846
1847int ocfs2_try_open_lock(struct inode *inode, int write)
1848{
1849 int status = 0, level;
1850 struct ocfs2_lock_res *lockres;
1851 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1852
1853 mlog(0, "inode %llu try to take %s open lock\n",
1854 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1855 write ? "EXMODE" : "PRMODE");
1856
1857 if (ocfs2_is_hard_readonly(osb)) {
1858 if (write)
1859 status = -EROFS;
1860 goto out;
1861 }
1862
1863 if (ocfs2_mount_local(osb))
1864 goto out;
1865
1866 lockres = &OCFS2_I(inode)->ip_open_lockres;
1867
1868 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1869
1870 /*
1871 * The file system may already holding a PRMODE/EXMODE open lock.
1872 * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on
1873 * other nodes and the -EAGAIN will indicate to the caller that
1874 * this inode is still in use.
1875 */
1876 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0);
1877
1878out:
1879 return status;
1880}
1881
1882/*
1883 * ocfs2_open_unlock unlock PR and EX mode open locks.
1884 */
1885void ocfs2_open_unlock(struct inode *inode)
1886{
1887 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
1888 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1889
1890 mlog(0, "inode %llu drop open lock\n",
1891 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1892
1893 if (ocfs2_mount_local(osb))
1894 goto out;
1895
1896 if(lockres->l_ro_holders)
1897 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_PR);
1898 if(lockres->l_ex_holders)
1899 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
1900
1901out:
1902 return;
1903}
1904
1905static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
1906 int level)
1907{
1908 int ret;
1909 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1910 unsigned long flags;
1911 struct ocfs2_mask_waiter mw;
1912
1913 ocfs2_init_mask_waiter(&mw);
1914
1915retry_cancel:
1916 spin_lock_irqsave(&lockres->l_lock, flags);
1917 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
1918 ret = ocfs2_prepare_cancel_convert(osb, lockres);
1919 if (ret) {
1920 spin_unlock_irqrestore(&lockres->l_lock, flags);
1921 ret = ocfs2_cancel_convert(osb, lockres);
1922 if (ret < 0) {
1923 mlog_errno(ret);
1924 goto out;
1925 }
1926 goto retry_cancel;
1927 }
1928 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1929 spin_unlock_irqrestore(&lockres->l_lock, flags);
1930
1931 ocfs2_wait_for_mask(&mw);
1932 goto retry_cancel;
1933 }
1934
1935 ret = -ERESTARTSYS;
1936 /*
1937 * We may still have gotten the lock, in which case there's no
1938 * point to restarting the syscall.
1939 */
1940 if (lockres->l_level == level)
1941 ret = 0;
1942
1943 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
1944 lockres->l_flags, lockres->l_level, lockres->l_action);
1945
1946 spin_unlock_irqrestore(&lockres->l_lock, flags);
1947
1948out:
1949 return ret;
1950}
1951
1952/*
1953 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
1954 * flock() calls. The locking approach this requires is sufficiently
1955 * different from all other cluster lock types that we implement a
1956 * separate path to the "low-level" dlm calls. In particular:
1957 *
1958 * - No optimization of lock levels is done - we take at exactly
1959 * what's been requested.
1960 *
1961 * - No lock caching is employed. We immediately downconvert to
1962 * no-lock at unlock time. This also means flock locks never go on
1963 * the blocking list).
1964 *
1965 * - Since userspace can trivially deadlock itself with flock, we make
1966 * sure to allow cancellation of a misbehaving applications flock()
1967 * request.
1968 *
1969 * - Access to any flock lockres doesn't require concurrency, so we
1970 * can simplify the code by requiring the caller to guarantee
1971 * serialization of dlmglue flock calls.
1972 */
1973int ocfs2_file_lock(struct file *file, int ex, int trylock)
1974{
1975 int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1976 unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
1977 unsigned long flags;
1978 struct ocfs2_file_private *fp = file->private_data;
1979 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1980 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1981 struct ocfs2_mask_waiter mw;
1982
1983 ocfs2_init_mask_waiter(&mw);
1984
1985 if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
1986 (lockres->l_level > DLM_LOCK_NL)) {
1987 mlog(ML_ERROR,
1988 "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
1989 "level: %u\n", lockres->l_name, lockres->l_flags,
1990 lockres->l_level);
1991 return -EINVAL;
1992 }
1993
1994 spin_lock_irqsave(&lockres->l_lock, flags);
1995 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1996 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1997 spin_unlock_irqrestore(&lockres->l_lock, flags);
1998
1999 /*
2000 * Get the lock at NLMODE to start - that way we
2001 * can cancel the upconvert request if need be.
2002 */
2003 ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
2004 if (ret < 0) {
2005 mlog_errno(ret);
2006 goto out;
2007 }
2008
2009 ret = ocfs2_wait_for_mask(&mw);
2010 if (ret) {
2011 mlog_errno(ret);
2012 goto out;
2013 }
2014 spin_lock_irqsave(&lockres->l_lock, flags);
2015 }
2016
2017 lockres->l_action = OCFS2_AST_CONVERT;
2018 lkm_flags |= DLM_LKF_CONVERT;
2019 lockres->l_requested = level;
2020 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2021
2022 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
2023 spin_unlock_irqrestore(&lockres->l_lock, flags);
2024
2025 ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags,
2026 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1);
2027 if (ret) {
2028 if (!trylock || (ret != -EAGAIN)) {
2029 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
2030 ret = -EINVAL;
2031 }
2032
2033 ocfs2_recover_from_dlm_error(lockres, 1);
2034 lockres_remove_mask_waiter(lockres, &mw);
2035 goto out;
2036 }
2037
2038 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
2039 if (ret == -ERESTARTSYS) {
2040 /*
2041 * Userspace can cause deadlock itself with
2042 * flock(). Current behavior locally is to allow the
2043 * deadlock, but abort the system call if a signal is
2044 * received. We follow this example, otherwise a
2045 * poorly written program could sit in kernel until
2046 * reboot.
2047 *
2048 * Handling this is a bit more complicated for Ocfs2
2049 * though. We can't exit this function with an
2050 * outstanding lock request, so a cancel convert is
2051 * required. We intentionally overwrite 'ret' - if the
2052 * cancel fails and the lock was granted, it's easier
2053 * to just bubble success back up to the user.
2054 */
2055 ret = ocfs2_flock_handle_signal(lockres, level);
2056 } else if (!ret && (level > lockres->l_level)) {
2057 /* Trylock failed asynchronously */
2058 BUG_ON(!trylock);
2059 ret = -EAGAIN;
2060 }
2061
2062out:
2063
2064 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
2065 lockres->l_name, ex, trylock, ret);
2066 return ret;
2067}
2068
2069void ocfs2_file_unlock(struct file *file)
2070{
2071 int ret;
2072 unsigned int gen;
2073 unsigned long flags;
2074 struct ocfs2_file_private *fp = file->private_data;
2075 struct ocfs2_lock_res *lockres = &fp->fp_flock;
2076 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
2077 struct ocfs2_mask_waiter mw;
2078
2079 ocfs2_init_mask_waiter(&mw);
2080
2081 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
2082 return;
2083
2084 if (lockres->l_level == DLM_LOCK_NL)
2085 return;
2086
2087 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
2088 lockres->l_name, lockres->l_flags, lockres->l_level,
2089 lockres->l_action);
2090
2091 spin_lock_irqsave(&lockres->l_lock, flags);
2092 /*
2093 * Fake a blocking ast for the downconvert code.
2094 */
2095 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
2096 lockres->l_blocking = DLM_LOCK_EX;
2097
2098 gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
2099 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
2100 spin_unlock_irqrestore(&lockres->l_lock, flags);
2101
2102 ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
2103 if (ret) {
2104 mlog_errno(ret);
2105 return;
2106 }
2107
2108 ret = ocfs2_wait_for_mask(&mw);
2109 if (ret)
2110 mlog_errno(ret);
2111}
2112
2113static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
2114 struct ocfs2_lock_res *lockres)
2115{
2116 int kick = 0;
2117
2118 /* If we know that another node is waiting on our lock, kick
2119 * the downconvert thread * pre-emptively when we reach a release
2120 * condition. */
2121 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
2122 switch(lockres->l_blocking) {
2123 case DLM_LOCK_EX:
2124 if (!lockres->l_ex_holders && !lockres->l_ro_holders)
2125 kick = 1;
2126 break;
2127 case DLM_LOCK_PR:
2128 if (!lockres->l_ex_holders)
2129 kick = 1;
2130 break;
2131 default:
2132 BUG();
2133 }
2134 }
2135
2136 if (kick)
2137 ocfs2_wake_downconvert_thread(osb);
2138}
2139
2140#define OCFS2_SEC_BITS 34
2141#define OCFS2_SEC_SHIFT (64 - OCFS2_SEC_BITS)
2142#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
2143
2144/* LVB only has room for 64 bits of time here so we pack it for
2145 * now. */
2146static u64 ocfs2_pack_timespec(struct timespec64 *spec)
2147{
2148 u64 res;
2149 u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull);
2150 u32 nsec = spec->tv_nsec;
2151
2152 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
2153
2154 return res;
2155}
2156
2157/* Call this with the lockres locked. I am reasonably sure we don't
2158 * need ip_lock in this function as anyone who would be changing those
2159 * values is supposed to be blocked in ocfs2_inode_lock right now. */
2160static void __ocfs2_stuff_meta_lvb(struct inode *inode)
2161{
2162 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2163 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2164 struct ocfs2_meta_lvb *lvb;
2165
2166 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2167
2168 /*
2169 * Invalidate the LVB of a deleted inode - this way other
2170 * nodes are forced to go to disk and discover the new inode
2171 * status.
2172 */
2173 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2174 lvb->lvb_version = 0;
2175 goto out;
2176 }
2177
2178 lvb->lvb_version = OCFS2_LVB_VERSION;
2179 lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
2180 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
2181 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode));
2182 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
2183 lvb->lvb_imode = cpu_to_be16(inode->i_mode);
2184 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
2185 lvb->lvb_iatime_packed =
2186 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
2187 lvb->lvb_ictime_packed =
2188 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
2189 lvb->lvb_imtime_packed =
2190 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
2191 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
2192 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
2193 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
2194
2195out:
2196 mlog_meta_lvb(0, lockres);
2197}
2198
2199static void ocfs2_unpack_timespec(struct timespec64 *spec,
2200 u64 packed_time)
2201{
2202 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
2203 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
2204}
2205
2206static int ocfs2_refresh_inode_from_lvb(struct inode *inode)
2207{
2208 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2209 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2210 struct ocfs2_meta_lvb *lvb;
2211
2212 mlog_meta_lvb(0, lockres);
2213
2214 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2215 if (inode_wrong_type(inode, be16_to_cpu(lvb->lvb_imode)))
2216 return -ESTALE;
2217
2218 /* We're safe here without the lockres lock... */
2219 spin_lock(&oi->ip_lock);
2220 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
2221 i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
2222
2223 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
2224 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
2225 ocfs2_set_inode_flags(inode);
2226
2227 /* fast-symlinks are a special case */
2228 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
2229 inode->i_blocks = 0;
2230 else
2231 inode->i_blocks = ocfs2_inode_sector_count(inode);
2232
2233 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid));
2234 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
2235 inode->i_mode = be16_to_cpu(lvb->lvb_imode);
2236 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
2237 ocfs2_unpack_timespec(&inode->i_atime,
2238 be64_to_cpu(lvb->lvb_iatime_packed));
2239 ocfs2_unpack_timespec(&inode->i_mtime,
2240 be64_to_cpu(lvb->lvb_imtime_packed));
2241 ocfs2_unpack_timespec(&inode->i_ctime,
2242 be64_to_cpu(lvb->lvb_ictime_packed));
2243 spin_unlock(&oi->ip_lock);
2244 return 0;
2245}
2246
2247static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
2248 struct ocfs2_lock_res *lockres)
2249{
2250 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2251
2252 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
2253 && lvb->lvb_version == OCFS2_LVB_VERSION
2254 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
2255 return 1;
2256 return 0;
2257}
2258
2259/* Determine whether a lock resource needs to be refreshed, and
2260 * arbitrate who gets to refresh it.
2261 *
2262 * 0 means no refresh needed.
2263 *
2264 * > 0 means you need to refresh this and you MUST call
2265 * ocfs2_complete_lock_res_refresh afterwards. */
2266static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
2267{
2268 unsigned long flags;
2269 int status = 0;
2270
2271refresh_check:
2272 spin_lock_irqsave(&lockres->l_lock, flags);
2273 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
2274 spin_unlock_irqrestore(&lockres->l_lock, flags);
2275 goto bail;
2276 }
2277
2278 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
2279 spin_unlock_irqrestore(&lockres->l_lock, flags);
2280
2281 ocfs2_wait_on_refreshing_lock(lockres);
2282 goto refresh_check;
2283 }
2284
2285 /* Ok, I'll be the one to refresh this lock. */
2286 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
2287 spin_unlock_irqrestore(&lockres->l_lock, flags);
2288
2289 status = 1;
2290bail:
2291 mlog(0, "status %d\n", status);
2292 return status;
2293}
2294
2295/* If status is non zero, I'll mark it as not being in refresh
2296 * anymroe, but i won't clear the needs refresh flag. */
2297static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
2298 int status)
2299{
2300 unsigned long flags;
2301
2302 spin_lock_irqsave(&lockres->l_lock, flags);
2303 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
2304 if (!status)
2305 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
2306 spin_unlock_irqrestore(&lockres->l_lock, flags);
2307
2308 wake_up(&lockres->l_event);
2309}
2310
2311/* may or may not return a bh if it went to disk. */
2312static int ocfs2_inode_lock_update(struct inode *inode,
2313 struct buffer_head **bh)
2314{
2315 int status = 0;
2316 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2317 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2318 struct ocfs2_dinode *fe;
2319 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2320
2321 if (ocfs2_mount_local(osb))
2322 goto bail;
2323
2324 spin_lock(&oi->ip_lock);
2325 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2326 mlog(0, "Orphaned inode %llu was deleted while we "
2327 "were waiting on a lock. ip_flags = 0x%x\n",
2328 (unsigned long long)oi->ip_blkno, oi->ip_flags);
2329 spin_unlock(&oi->ip_lock);
2330 status = -ENOENT;
2331 goto bail;
2332 }
2333 spin_unlock(&oi->ip_lock);
2334
2335 if (!ocfs2_should_refresh_lock_res(lockres))
2336 goto bail;
2337
2338 /* This will discard any caching information we might have had
2339 * for the inode metadata. */
2340 ocfs2_metadata_cache_purge(INODE_CACHE(inode));
2341
2342 ocfs2_extent_map_trunc(inode, 0);
2343
2344 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
2345 mlog(0, "Trusting LVB on inode %llu\n",
2346 (unsigned long long)oi->ip_blkno);
2347 status = ocfs2_refresh_inode_from_lvb(inode);
2348 goto bail_refresh;
2349 } else {
2350 /* Boo, we have to go to disk. */
2351 /* read bh, cast, ocfs2_refresh_inode */
2352 status = ocfs2_read_inode_block(inode, bh);
2353 if (status < 0) {
2354 mlog_errno(status);
2355 goto bail_refresh;
2356 }
2357 fe = (struct ocfs2_dinode *) (*bh)->b_data;
2358 if (inode_wrong_type(inode, le16_to_cpu(fe->i_mode))) {
2359 status = -ESTALE;
2360 goto bail_refresh;
2361 }
2362
2363 /* This is a good chance to make sure we're not
2364 * locking an invalid object. ocfs2_read_inode_block()
2365 * already checked that the inode block is sane.
2366 *
2367 * We bug on a stale inode here because we checked
2368 * above whether it was wiped from disk. The wiping
2369 * node provides a guarantee that we receive that
2370 * message and can mark the inode before dropping any
2371 * locks associated with it. */
2372 mlog_bug_on_msg(inode->i_generation !=
2373 le32_to_cpu(fe->i_generation),
2374 "Invalid dinode %llu disk generation: %u "
2375 "inode->i_generation: %u\n",
2376 (unsigned long long)oi->ip_blkno,
2377 le32_to_cpu(fe->i_generation),
2378 inode->i_generation);
2379 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
2380 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
2381 "Stale dinode %llu dtime: %llu flags: 0x%x\n",
2382 (unsigned long long)oi->ip_blkno,
2383 (unsigned long long)le64_to_cpu(fe->i_dtime),
2384 le32_to_cpu(fe->i_flags));
2385
2386 ocfs2_refresh_inode(inode, fe);
2387 ocfs2_track_lock_refresh(lockres);
2388 }
2389
2390 status = 0;
2391bail_refresh:
2392 ocfs2_complete_lock_res_refresh(lockres, status);
2393bail:
2394 return status;
2395}
2396
2397static int ocfs2_assign_bh(struct inode *inode,
2398 struct buffer_head **ret_bh,
2399 struct buffer_head *passed_bh)
2400{
2401 int status;
2402
2403 if (passed_bh) {
2404 /* Ok, the update went to disk for us, use the
2405 * returned bh. */
2406 *ret_bh = passed_bh;
2407 get_bh(*ret_bh);
2408
2409 return 0;
2410 }
2411
2412 status = ocfs2_read_inode_block(inode, ret_bh);
2413 if (status < 0)
2414 mlog_errno(status);
2415
2416 return status;
2417}
2418
2419/*
2420 * returns < 0 error if the callback will never be called, otherwise
2421 * the result of the lock will be communicated via the callback.
2422 */
2423int ocfs2_inode_lock_full_nested(struct inode *inode,
2424 struct buffer_head **ret_bh,
2425 int ex,
2426 int arg_flags,
2427 int subclass)
2428{
2429 int status, level, acquired;
2430 u32 dlm_flags;
2431 struct ocfs2_lock_res *lockres = NULL;
2432 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2433 struct buffer_head *local_bh = NULL;
2434
2435 mlog(0, "inode %llu, take %s META lock\n",
2436 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2437 ex ? "EXMODE" : "PRMODE");
2438
2439 status = 0;
2440 acquired = 0;
2441 /* We'll allow faking a readonly metadata lock for
2442 * rodevices. */
2443 if (ocfs2_is_hard_readonly(osb)) {
2444 if (ex)
2445 status = -EROFS;
2446 goto getbh;
2447 }
2448
2449 if ((arg_flags & OCFS2_META_LOCK_GETBH) ||
2450 ocfs2_mount_local(osb))
2451 goto update;
2452
2453 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2454 ocfs2_wait_for_recovery(osb);
2455
2456 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2457 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2458 dlm_flags = 0;
2459 if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
2460 dlm_flags |= DLM_LKF_NOQUEUE;
2461
2462 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
2463 arg_flags, subclass, _RET_IP_);
2464 if (status < 0) {
2465 if (status != -EAGAIN)
2466 mlog_errno(status);
2467 goto bail;
2468 }
2469
2470 /* Notify the error cleanup path to drop the cluster lock. */
2471 acquired = 1;
2472
2473 /* We wait twice because a node may have died while we were in
2474 * the lower dlm layers. The second time though, we've
2475 * committed to owning this lock so we don't allow signals to
2476 * abort the operation. */
2477 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2478 ocfs2_wait_for_recovery(osb);
2479
2480update:
2481 /*
2482 * We only see this flag if we're being called from
2483 * ocfs2_read_locked_inode(). It means we're locking an inode
2484 * which hasn't been populated yet, so clear the refresh flag
2485 * and let the caller handle it.
2486 */
2487 if (inode->i_state & I_NEW) {
2488 status = 0;
2489 if (lockres)
2490 ocfs2_complete_lock_res_refresh(lockres, 0);
2491 goto bail;
2492 }
2493
2494 /* This is fun. The caller may want a bh back, or it may
2495 * not. ocfs2_inode_lock_update definitely wants one in, but
2496 * may or may not read one, depending on what's in the
2497 * LVB. The result of all of this is that we've *only* gone to
2498 * disk if we have to, so the complexity is worthwhile. */
2499 status = ocfs2_inode_lock_update(inode, &local_bh);
2500 if (status < 0) {
2501 if (status != -ENOENT)
2502 mlog_errno(status);
2503 goto bail;
2504 }
2505getbh:
2506 if (ret_bh) {
2507 status = ocfs2_assign_bh(inode, ret_bh, local_bh);
2508 if (status < 0) {
2509 mlog_errno(status);
2510 goto bail;
2511 }
2512 }
2513
2514bail:
2515 if (status < 0) {
2516 if (ret_bh && (*ret_bh)) {
2517 brelse(*ret_bh);
2518 *ret_bh = NULL;
2519 }
2520 if (acquired)
2521 ocfs2_inode_unlock(inode, ex);
2522 }
2523
2524 brelse(local_bh);
2525 return status;
2526}
2527
2528/*
2529 * This is working around a lock inversion between tasks acquiring DLM
2530 * locks while holding a page lock and the downconvert thread which
2531 * blocks dlm lock acquiry while acquiring page locks.
2532 *
2533 * ** These _with_page variantes are only intended to be called from aop
2534 * methods that hold page locks and return a very specific *positive* error
2535 * code that aop methods pass up to the VFS -- test for errors with != 0. **
2536 *
2537 * The DLM is called such that it returns -EAGAIN if it would have
2538 * blocked waiting for the downconvert thread. In that case we unlock
2539 * our page so the downconvert thread can make progress. Once we've
2540 * done this we have to return AOP_TRUNCATED_PAGE so the aop method
2541 * that called us can bubble that back up into the VFS who will then
2542 * immediately retry the aop call.
2543 */
2544int ocfs2_inode_lock_with_page(struct inode *inode,
2545 struct buffer_head **ret_bh,
2546 int ex,
2547 struct page *page)
2548{
2549 int ret;
2550
2551 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
2552 if (ret == -EAGAIN) {
2553 unlock_page(page);
2554 /*
2555 * If we can't get inode lock immediately, we should not return
2556 * directly here, since this will lead to a softlockup problem.
2557 * The method is to get a blocking lock and immediately unlock
2558 * before returning, this can avoid CPU resource waste due to
2559 * lots of retries, and benefits fairness in getting lock.
2560 */
2561 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
2562 ocfs2_inode_unlock(inode, ex);
2563 ret = AOP_TRUNCATED_PAGE;
2564 }
2565
2566 return ret;
2567}
2568
2569int ocfs2_inode_lock_atime(struct inode *inode,
2570 struct vfsmount *vfsmnt,
2571 int *level, int wait)
2572{
2573 int ret;
2574
2575 if (wait)
2576 ret = ocfs2_inode_lock(inode, NULL, 0);
2577 else
2578 ret = ocfs2_try_inode_lock(inode, NULL, 0);
2579
2580 if (ret < 0) {
2581 if (ret != -EAGAIN)
2582 mlog_errno(ret);
2583 return ret;
2584 }
2585
2586 /*
2587 * If we should update atime, we will get EX lock,
2588 * otherwise we just get PR lock.
2589 */
2590 if (ocfs2_should_update_atime(inode, vfsmnt)) {
2591 struct buffer_head *bh = NULL;
2592
2593 ocfs2_inode_unlock(inode, 0);
2594 if (wait)
2595 ret = ocfs2_inode_lock(inode, &bh, 1);
2596 else
2597 ret = ocfs2_try_inode_lock(inode, &bh, 1);
2598
2599 if (ret < 0) {
2600 if (ret != -EAGAIN)
2601 mlog_errno(ret);
2602 return ret;
2603 }
2604 *level = 1;
2605 if (ocfs2_should_update_atime(inode, vfsmnt))
2606 ocfs2_update_inode_atime(inode, bh);
2607 brelse(bh);
2608 } else
2609 *level = 0;
2610
2611 return ret;
2612}
2613
2614void ocfs2_inode_unlock(struct inode *inode,
2615 int ex)
2616{
2617 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2618 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
2619 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2620
2621 mlog(0, "inode %llu drop %s META lock\n",
2622 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2623 ex ? "EXMODE" : "PRMODE");
2624
2625 if (!ocfs2_is_hard_readonly(osb) &&
2626 !ocfs2_mount_local(osb))
2627 ocfs2_cluster_unlock(osb, lockres, level);
2628}
2629
2630/*
2631 * This _tracker variantes are introduced to deal with the recursive cluster
2632 * locking issue. The idea is to keep track of a lock holder on the stack of
2633 * the current process. If there's a lock holder on the stack, we know the
2634 * task context is already protected by cluster locking. Currently, they're
2635 * used in some VFS entry routines.
2636 *
2637 * return < 0 on error, return == 0 if there's no lock holder on the stack
2638 * before this call, return == 1 if this call would be a recursive locking.
2639 * return == -1 if this lock attempt will cause an upgrade which is forbidden.
2640 *
2641 * When taking lock levels into account,we face some different situations.
2642 *
2643 * 1. no lock is held
2644 * In this case, just lock the inode as requested and return 0
2645 *
2646 * 2. We are holding a lock
2647 * For this situation, things diverges into several cases
2648 *
2649 * wanted holding what to do
2650 * ex ex see 2.1 below
2651 * ex pr see 2.2 below
2652 * pr ex see 2.1 below
2653 * pr pr see 2.1 below
2654 *
2655 * 2.1 lock level that is been held is compatible
2656 * with the wanted level, so no lock action will be tacken.
2657 *
2658 * 2.2 Otherwise, an upgrade is needed, but it is forbidden.
2659 *
2660 * Reason why upgrade within a process is forbidden is that
2661 * lock upgrade may cause dead lock. The following illustrates
2662 * how it happens.
2663 *
2664 * thread on node1 thread on node2
2665 * ocfs2_inode_lock_tracker(ex=0)
2666 *
2667 * <====== ocfs2_inode_lock_tracker(ex=1)
2668 *
2669 * ocfs2_inode_lock_tracker(ex=1)
2670 */
2671int ocfs2_inode_lock_tracker(struct inode *inode,
2672 struct buffer_head **ret_bh,
2673 int ex,
2674 struct ocfs2_lock_holder *oh)
2675{
2676 int status = 0;
2677 struct ocfs2_lock_res *lockres;
2678 struct ocfs2_lock_holder *tmp_oh;
2679 struct pid *pid = task_pid(current);
2680
2681
2682 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2683 tmp_oh = ocfs2_pid_holder(lockres, pid);
2684
2685 if (!tmp_oh) {
2686 /*
2687 * This corresponds to the case 1.
2688 * We haven't got any lock before.
2689 */
2690 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0);
2691 if (status < 0) {
2692 if (status != -ENOENT)
2693 mlog_errno(status);
2694 return status;
2695 }
2696
2697 oh->oh_ex = ex;
2698 ocfs2_add_holder(lockres, oh);
2699 return 0;
2700 }
2701
2702 if (unlikely(ex && !tmp_oh->oh_ex)) {
2703 /*
2704 * case 2.2 upgrade may cause dead lock, forbid it.
2705 */
2706 mlog(ML_ERROR, "Recursive locking is not permitted to "
2707 "upgrade to EX level from PR level.\n");
2708 dump_stack();
2709 return -EINVAL;
2710 }
2711
2712 /*
2713 * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full.
2714 * ignore the lock level and just update it.
2715 */
2716 if (ret_bh) {
2717 status = ocfs2_inode_lock_full(inode, ret_bh, ex,
2718 OCFS2_META_LOCK_GETBH);
2719 if (status < 0) {
2720 if (status != -ENOENT)
2721 mlog_errno(status);
2722 return status;
2723 }
2724 }
2725 return 1;
2726}
2727
2728void ocfs2_inode_unlock_tracker(struct inode *inode,
2729 int ex,
2730 struct ocfs2_lock_holder *oh,
2731 int had_lock)
2732{
2733 struct ocfs2_lock_res *lockres;
2734
2735 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2736 /* had_lock means that the currect process already takes the cluster
2737 * lock previously.
2738 * If had_lock is 1, we have nothing to do here.
2739 * If had_lock is 0, we will release the lock.
2740 */
2741 if (!had_lock) {
2742 ocfs2_inode_unlock(inode, oh->oh_ex);
2743 ocfs2_remove_holder(lockres, oh);
2744 }
2745}
2746
2747int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
2748{
2749 struct ocfs2_lock_res *lockres;
2750 struct ocfs2_orphan_scan_lvb *lvb;
2751 int status = 0;
2752
2753 if (ocfs2_is_hard_readonly(osb))
2754 return -EROFS;
2755
2756 if (ocfs2_mount_local(osb))
2757 return 0;
2758
2759 lockres = &osb->osb_orphan_scan.os_lockres;
2760 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2761 if (status < 0)
2762 return status;
2763
2764 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2765 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2766 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
2767 *seqno = be32_to_cpu(lvb->lvb_os_seqno);
2768 else
2769 *seqno = osb->osb_orphan_scan.os_seqno + 1;
2770
2771 return status;
2772}
2773
2774void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
2775{
2776 struct ocfs2_lock_res *lockres;
2777 struct ocfs2_orphan_scan_lvb *lvb;
2778
2779 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
2780 lockres = &osb->osb_orphan_scan.os_lockres;
2781 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2782 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
2783 lvb->lvb_os_seqno = cpu_to_be32(seqno);
2784 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2785 }
2786}
2787
2788int ocfs2_super_lock(struct ocfs2_super *osb,
2789 int ex)
2790{
2791 int status = 0;
2792 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2793 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2794
2795 if (ocfs2_is_hard_readonly(osb))
2796 return -EROFS;
2797
2798 if (ocfs2_mount_local(osb))
2799 goto bail;
2800
2801 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
2802 if (status < 0) {
2803 mlog_errno(status);
2804 goto bail;
2805 }
2806
2807 /* The super block lock path is really in the best position to
2808 * know when resources covered by the lock need to be
2809 * refreshed, so we do it here. Of course, making sense of
2810 * everything is up to the caller :) */
2811 status = ocfs2_should_refresh_lock_res(lockres);
2812 if (status) {
2813 status = ocfs2_refresh_slot_info(osb);
2814
2815 ocfs2_complete_lock_res_refresh(lockres, status);
2816
2817 if (status < 0) {
2818 ocfs2_cluster_unlock(osb, lockres, level);
2819 mlog_errno(status);
2820 }
2821 ocfs2_track_lock_refresh(lockres);
2822 }
2823bail:
2824 return status;
2825}
2826
2827void ocfs2_super_unlock(struct ocfs2_super *osb,
2828 int ex)
2829{
2830 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2831 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2832
2833 if (!ocfs2_mount_local(osb))
2834 ocfs2_cluster_unlock(osb, lockres, level);
2835}
2836
2837int ocfs2_rename_lock(struct ocfs2_super *osb)
2838{
2839 int status;
2840 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2841
2842 if (ocfs2_is_hard_readonly(osb))
2843 return -EROFS;
2844
2845 if (ocfs2_mount_local(osb))
2846 return 0;
2847
2848 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2849 if (status < 0)
2850 mlog_errno(status);
2851
2852 return status;
2853}
2854
2855void ocfs2_rename_unlock(struct ocfs2_super *osb)
2856{
2857 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2858
2859 if (!ocfs2_mount_local(osb))
2860 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2861}
2862
2863int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
2864{
2865 int status;
2866 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2867
2868 if (ocfs2_is_hard_readonly(osb))
2869 return -EROFS;
2870
2871 if (ex)
2872 down_write(&osb->nfs_sync_rwlock);
2873 else
2874 down_read(&osb->nfs_sync_rwlock);
2875
2876 if (ocfs2_mount_local(osb))
2877 return 0;
2878
2879 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
2880 0, 0);
2881 if (status < 0) {
2882 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
2883
2884 if (ex)
2885 up_write(&osb->nfs_sync_rwlock);
2886 else
2887 up_read(&osb->nfs_sync_rwlock);
2888 }
2889
2890 return status;
2891}
2892
2893void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
2894{
2895 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2896
2897 if (!ocfs2_mount_local(osb))
2898 ocfs2_cluster_unlock(osb, lockres,
2899 ex ? LKM_EXMODE : LKM_PRMODE);
2900 if (ex)
2901 up_write(&osb->nfs_sync_rwlock);
2902 else
2903 up_read(&osb->nfs_sync_rwlock);
2904}
2905
2906int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
2907 struct ocfs2_trim_fs_info *info, int trylock)
2908{
2909 int status;
2910 struct ocfs2_trim_fs_lvb *lvb;
2911 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2912
2913 if (info)
2914 info->tf_valid = 0;
2915
2916 if (ocfs2_is_hard_readonly(osb))
2917 return -EROFS;
2918
2919 if (ocfs2_mount_local(osb))
2920 return 0;
2921
2922 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX,
2923 trylock ? DLM_LKF_NOQUEUE : 0, 0);
2924 if (status < 0) {
2925 if (status != -EAGAIN)
2926 mlog_errno(status);
2927 return status;
2928 }
2929
2930 if (info) {
2931 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2932 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2933 lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) {
2934 info->tf_valid = 1;
2935 info->tf_success = lvb->lvb_success;
2936 info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum);
2937 info->tf_start = be64_to_cpu(lvb->lvb_start);
2938 info->tf_len = be64_to_cpu(lvb->lvb_len);
2939 info->tf_minlen = be64_to_cpu(lvb->lvb_minlen);
2940 info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen);
2941 }
2942 }
2943
2944 return status;
2945}
2946
2947void ocfs2_trim_fs_unlock(struct ocfs2_super *osb,
2948 struct ocfs2_trim_fs_info *info)
2949{
2950 struct ocfs2_trim_fs_lvb *lvb;
2951 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2952
2953 if (ocfs2_mount_local(osb))
2954 return;
2955
2956 if (info) {
2957 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2958 lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION;
2959 lvb->lvb_success = info->tf_success;
2960 lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum);
2961 lvb->lvb_start = cpu_to_be64(info->tf_start);
2962 lvb->lvb_len = cpu_to_be64(info->tf_len);
2963 lvb->lvb_minlen = cpu_to_be64(info->tf_minlen);
2964 lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen);
2965 }
2966
2967 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2968}
2969
2970int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2971{
2972 int ret;
2973 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2974 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2975 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2976
2977 BUG_ON(!dl);
2978
2979 if (ocfs2_is_hard_readonly(osb)) {
2980 if (ex)
2981 return -EROFS;
2982 return 0;
2983 }
2984
2985 if (ocfs2_mount_local(osb))
2986 return 0;
2987
2988 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2989 if (ret < 0)
2990 mlog_errno(ret);
2991
2992 return ret;
2993}
2994
2995void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2996{
2997 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2998 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2999 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
3000
3001 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
3002 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
3003}
3004
3005/* Reference counting of the dlm debug structure. We want this because
3006 * open references on the debug inodes can live on after a mount, so
3007 * we can't rely on the ocfs2_super to always exist. */
3008static void ocfs2_dlm_debug_free(struct kref *kref)
3009{
3010 struct ocfs2_dlm_debug *dlm_debug;
3011
3012 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
3013
3014 kfree(dlm_debug);
3015}
3016
3017void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
3018{
3019 if (dlm_debug)
3020 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
3021}
3022
3023static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
3024{
3025 kref_get(&debug->d_refcnt);
3026}
3027
3028struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
3029{
3030 struct ocfs2_dlm_debug *dlm_debug;
3031
3032 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
3033 if (!dlm_debug) {
3034 mlog_errno(-ENOMEM);
3035 goto out;
3036 }
3037
3038 kref_init(&dlm_debug->d_refcnt);
3039 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
3040 dlm_debug->d_filter_secs = 0;
3041out:
3042 return dlm_debug;
3043}
3044
3045/* Access to this is arbitrated for us via seq_file->sem. */
3046struct ocfs2_dlm_seq_priv {
3047 struct ocfs2_dlm_debug *p_dlm_debug;
3048 struct ocfs2_lock_res p_iter_res;
3049 struct ocfs2_lock_res p_tmp_res;
3050};
3051
3052static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
3053 struct ocfs2_dlm_seq_priv *priv)
3054{
3055 struct ocfs2_lock_res *iter, *ret = NULL;
3056 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
3057
3058 assert_spin_locked(&ocfs2_dlm_tracking_lock);
3059
3060 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
3061 /* discover the head of the list */
3062 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
3063 mlog(0, "End of list found, %p\n", ret);
3064 break;
3065 }
3066
3067 /* We track our "dummy" iteration lockres' by a NULL
3068 * l_ops field. */
3069 if (iter->l_ops != NULL) {
3070 ret = iter;
3071 break;
3072 }
3073 }
3074
3075 return ret;
3076}
3077
3078static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
3079{
3080 struct ocfs2_dlm_seq_priv *priv = m->private;
3081 struct ocfs2_lock_res *iter;
3082
3083 spin_lock(&ocfs2_dlm_tracking_lock);
3084 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
3085 if (iter) {
3086 /* Since lockres' have the lifetime of their container
3087 * (which can be inodes, ocfs2_supers, etc) we want to
3088 * copy this out to a temporary lockres while still
3089 * under the spinlock. Obviously after this we can't
3090 * trust any pointers on the copy returned, but that's
3091 * ok as the information we want isn't typically held
3092 * in them. */
3093 priv->p_tmp_res = *iter;
3094 iter = &priv->p_tmp_res;
3095 }
3096 spin_unlock(&ocfs2_dlm_tracking_lock);
3097
3098 return iter;
3099}
3100
3101static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
3102{
3103}
3104
3105static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
3106{
3107 struct ocfs2_dlm_seq_priv *priv = m->private;
3108 struct ocfs2_lock_res *iter = v;
3109 struct ocfs2_lock_res *dummy = &priv->p_iter_res;
3110
3111 spin_lock(&ocfs2_dlm_tracking_lock);
3112 iter = ocfs2_dlm_next_res(iter, priv);
3113 list_del_init(&dummy->l_debug_list);
3114 if (iter) {
3115 list_add(&dummy->l_debug_list, &iter->l_debug_list);
3116 priv->p_tmp_res = *iter;
3117 iter = &priv->p_tmp_res;
3118 }
3119 spin_unlock(&ocfs2_dlm_tracking_lock);
3120
3121 return iter;
3122}
3123
3124/*
3125 * Version is used by debugfs.ocfs2 to determine the format being used
3126 *
3127 * New in version 2
3128 * - Lock stats printed
3129 * New in version 3
3130 * - Max time in lock stats is in usecs (instead of nsecs)
3131 * New in version 4
3132 * - Add last pr/ex unlock times and first lock wait time in usecs
3133 */
3134#define OCFS2_DLM_DEBUG_STR_VERSION 4
3135static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
3136{
3137 int i;
3138 char *lvb;
3139 struct ocfs2_lock_res *lockres = v;
3140#ifdef CONFIG_OCFS2_FS_STATS
3141 u64 now, last;
3142 struct ocfs2_dlm_debug *dlm_debug =
3143 ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug;
3144#endif
3145
3146 if (!lockres)
3147 return -EINVAL;
3148
3149#ifdef CONFIG_OCFS2_FS_STATS
3150 if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) {
3151 now = ktime_to_us(ktime_get_real());
3152 if (lockres->l_lock_prmode.ls_last >
3153 lockres->l_lock_exmode.ls_last)
3154 last = lockres->l_lock_prmode.ls_last;
3155 else
3156 last = lockres->l_lock_exmode.ls_last;
3157 /*
3158 * Use d_filter_secs field to filter lock resources dump,
3159 * the default d_filter_secs(0) value filters nothing,
3160 * otherwise, only dump the last N seconds active lock
3161 * resources.
3162 */
3163 if (div_u64(now - last, 1000000) > dlm_debug->d_filter_secs)
3164 return 0;
3165 }
3166#endif
3167
3168 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
3169
3170 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
3171 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
3172 lockres->l_name,
3173 (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
3174 else
3175 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
3176
3177 seq_printf(m, "%d\t"
3178 "0x%lx\t"
3179 "0x%x\t"
3180 "0x%x\t"
3181 "%u\t"
3182 "%u\t"
3183 "%d\t"
3184 "%d\t",
3185 lockres->l_level,
3186 lockres->l_flags,
3187 lockres->l_action,
3188 lockres->l_unlock_action,
3189 lockres->l_ro_holders,
3190 lockres->l_ex_holders,
3191 lockres->l_requested,
3192 lockres->l_blocking);
3193
3194 /* Dump the raw LVB */
3195 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
3196 for(i = 0; i < DLM_LVB_LEN; i++)
3197 seq_printf(m, "0x%x\t", lvb[i]);
3198
3199#ifdef CONFIG_OCFS2_FS_STATS
3200# define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets)
3201# define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets)
3202# define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail)
3203# define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail)
3204# define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total)
3205# define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total)
3206# define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max)
3207# define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max)
3208# define lock_refresh(_l) ((_l)->l_lock_refresh)
3209# define lock_last_prmode(_l) ((_l)->l_lock_prmode.ls_last)
3210# define lock_last_exmode(_l) ((_l)->l_lock_exmode.ls_last)
3211# define lock_wait(_l) ((_l)->l_lock_wait)
3212#else
3213# define lock_num_prmode(_l) (0)
3214# define lock_num_exmode(_l) (0)
3215# define lock_num_prmode_failed(_l) (0)
3216# define lock_num_exmode_failed(_l) (0)
3217# define lock_total_prmode(_l) (0ULL)
3218# define lock_total_exmode(_l) (0ULL)
3219# define lock_max_prmode(_l) (0)
3220# define lock_max_exmode(_l) (0)
3221# define lock_refresh(_l) (0)
3222# define lock_last_prmode(_l) (0ULL)
3223# define lock_last_exmode(_l) (0ULL)
3224# define lock_wait(_l) (0ULL)
3225#endif
3226 /* The following seq_print was added in version 2 of this output */
3227 seq_printf(m, "%u\t"
3228 "%u\t"
3229 "%u\t"
3230 "%u\t"
3231 "%llu\t"
3232 "%llu\t"
3233 "%u\t"
3234 "%u\t"
3235 "%u\t"
3236 "%llu\t"
3237 "%llu\t"
3238 "%llu\t",
3239 lock_num_prmode(lockres),
3240 lock_num_exmode(lockres),
3241 lock_num_prmode_failed(lockres),
3242 lock_num_exmode_failed(lockres),
3243 lock_total_prmode(lockres),
3244 lock_total_exmode(lockres),
3245 lock_max_prmode(lockres),
3246 lock_max_exmode(lockres),
3247 lock_refresh(lockres),
3248 lock_last_prmode(lockres),
3249 lock_last_exmode(lockres),
3250 lock_wait(lockres));
3251
3252 /* End the line */
3253 seq_printf(m, "\n");
3254 return 0;
3255}
3256
3257static const struct seq_operations ocfs2_dlm_seq_ops = {
3258 .start = ocfs2_dlm_seq_start,
3259 .stop = ocfs2_dlm_seq_stop,
3260 .next = ocfs2_dlm_seq_next,
3261 .show = ocfs2_dlm_seq_show,
3262};
3263
3264static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
3265{
3266 struct seq_file *seq = file->private_data;
3267 struct ocfs2_dlm_seq_priv *priv = seq->private;
3268 struct ocfs2_lock_res *res = &priv->p_iter_res;
3269
3270 ocfs2_remove_lockres_tracking(res);
3271 ocfs2_put_dlm_debug(priv->p_dlm_debug);
3272 return seq_release_private(inode, file);
3273}
3274
3275static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
3276{
3277 struct ocfs2_dlm_seq_priv *priv;
3278 struct ocfs2_super *osb;
3279
3280 priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv));
3281 if (!priv) {
3282 mlog_errno(-ENOMEM);
3283 return -ENOMEM;
3284 }
3285
3286 osb = inode->i_private;
3287 ocfs2_get_dlm_debug(osb->osb_dlm_debug);
3288 priv->p_dlm_debug = osb->osb_dlm_debug;
3289 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
3290
3291 ocfs2_add_lockres_tracking(&priv->p_iter_res,
3292 priv->p_dlm_debug);
3293
3294 return 0;
3295}
3296
3297static const struct file_operations ocfs2_dlm_debug_fops = {
3298 .open = ocfs2_dlm_debug_open,
3299 .release = ocfs2_dlm_debug_release,
3300 .read = seq_read,
3301 .llseek = seq_lseek,
3302};
3303
3304static void ocfs2_dlm_init_debug(struct ocfs2_super *osb)
3305{
3306 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
3307
3308 debugfs_create_file("locking_state", S_IFREG|S_IRUSR,
3309 osb->osb_debug_root, osb, &ocfs2_dlm_debug_fops);
3310
3311 debugfs_create_u32("locking_filter", 0600, osb->osb_debug_root,
3312 &dlm_debug->d_filter_secs);
3313 ocfs2_get_dlm_debug(dlm_debug);
3314}
3315
3316static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
3317{
3318 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
3319
3320 if (dlm_debug)
3321 ocfs2_put_dlm_debug(dlm_debug);
3322}
3323
3324int ocfs2_dlm_init(struct ocfs2_super *osb)
3325{
3326 int status = 0;
3327 struct ocfs2_cluster_connection *conn = NULL;
3328
3329 if (ocfs2_mount_local(osb)) {
3330 osb->node_num = 0;
3331 goto local;
3332 }
3333
3334 ocfs2_dlm_init_debug(osb);
3335
3336 /* launch downconvert thread */
3337 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s",
3338 osb->uuid_str);
3339 if (IS_ERR(osb->dc_task)) {
3340 status = PTR_ERR(osb->dc_task);
3341 osb->dc_task = NULL;
3342 mlog_errno(status);
3343 goto bail;
3344 }
3345
3346 /* for now, uuid == domain */
3347 status = ocfs2_cluster_connect(osb->osb_cluster_stack,
3348 osb->osb_cluster_name,
3349 strlen(osb->osb_cluster_name),
3350 osb->uuid_str,
3351 strlen(osb->uuid_str),
3352 &lproto, ocfs2_do_node_down, osb,
3353 &conn);
3354 if (status) {
3355 mlog_errno(status);
3356 goto bail;
3357 }
3358
3359 status = ocfs2_cluster_this_node(conn, &osb->node_num);
3360 if (status < 0) {
3361 mlog_errno(status);
3362 mlog(ML_ERROR,
3363 "could not find this host's node number\n");
3364 ocfs2_cluster_disconnect(conn, 0);
3365 goto bail;
3366 }
3367
3368local:
3369 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
3370 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
3371 ocfs2_nfs_sync_lock_init(osb);
3372 ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
3373
3374 osb->cconn = conn;
3375bail:
3376 if (status < 0) {
3377 ocfs2_dlm_shutdown_debug(osb);
3378 if (osb->dc_task)
3379 kthread_stop(osb->dc_task);
3380 }
3381
3382 return status;
3383}
3384
3385void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
3386 int hangup_pending)
3387{
3388 ocfs2_drop_osb_locks(osb);
3389
3390 /*
3391 * Now that we have dropped all locks and ocfs2_dismount_volume()
3392 * has disabled recovery, the DLM won't be talking to us. It's
3393 * safe to tear things down before disconnecting the cluster.
3394 */
3395
3396 if (osb->dc_task) {
3397 kthread_stop(osb->dc_task);
3398 osb->dc_task = NULL;
3399 }
3400
3401 ocfs2_lock_res_free(&osb->osb_super_lockres);
3402 ocfs2_lock_res_free(&osb->osb_rename_lockres);
3403 ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
3404 ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
3405
3406 if (osb->cconn) {
3407 ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
3408 osb->cconn = NULL;
3409
3410 ocfs2_dlm_shutdown_debug(osb);
3411 }
3412}
3413
3414static int ocfs2_drop_lock(struct ocfs2_super *osb,
3415 struct ocfs2_lock_res *lockres)
3416{
3417 int ret;
3418 unsigned long flags;
3419 u32 lkm_flags = 0;
3420
3421 /* We didn't get anywhere near actually using this lockres. */
3422 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
3423 goto out;
3424
3425 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3426 lkm_flags |= DLM_LKF_VALBLK;
3427
3428 spin_lock_irqsave(&lockres->l_lock, flags);
3429
3430 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
3431 "lockres %s, flags 0x%lx\n",
3432 lockres->l_name, lockres->l_flags);
3433
3434 while (lockres->l_flags & OCFS2_LOCK_BUSY) {
3435 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
3436 "%u, unlock_action = %u\n",
3437 lockres->l_name, lockres->l_flags, lockres->l_action,
3438 lockres->l_unlock_action);
3439
3440 spin_unlock_irqrestore(&lockres->l_lock, flags);
3441
3442 /* XXX: Today we just wait on any busy
3443 * locks... Perhaps we need to cancel converts in the
3444 * future? */
3445 ocfs2_wait_on_busy_lock(lockres);
3446
3447 spin_lock_irqsave(&lockres->l_lock, flags);
3448 }
3449
3450 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3451 if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
3452 lockres->l_level == DLM_LOCK_EX &&
3453 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3454 lockres->l_ops->set_lvb(lockres);
3455 }
3456
3457 if (lockres->l_flags & OCFS2_LOCK_BUSY)
3458 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
3459 lockres->l_name);
3460 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
3461 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
3462
3463 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
3464 spin_unlock_irqrestore(&lockres->l_lock, flags);
3465 goto out;
3466 }
3467
3468 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
3469
3470 /* make sure we never get here while waiting for an ast to
3471 * fire. */
3472 BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
3473
3474 /* is this necessary? */
3475 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3476 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
3477 spin_unlock_irqrestore(&lockres->l_lock, flags);
3478
3479 mlog(0, "lock %s\n", lockres->l_name);
3480
3481 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags);
3482 if (ret) {
3483 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3484 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
3485 ocfs2_dlm_dump_lksb(&lockres->l_lksb);
3486 BUG();
3487 }
3488 mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n",
3489 lockres->l_name);
3490
3491 ocfs2_wait_on_busy_lock(lockres);
3492out:
3493 return 0;
3494}
3495
3496static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3497 struct ocfs2_lock_res *lockres);
3498
3499/* Mark the lockres as being dropped. It will no longer be
3500 * queued if blocking, but we still may have to wait on it
3501 * being dequeued from the downconvert thread before we can consider
3502 * it safe to drop.
3503 *
3504 * You can *not* attempt to call cluster_lock on this lockres anymore. */
3505void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb,
3506 struct ocfs2_lock_res *lockres)
3507{
3508 int status;
3509 struct ocfs2_mask_waiter mw;
3510 unsigned long flags, flags2;
3511
3512 ocfs2_init_mask_waiter(&mw);
3513
3514 spin_lock_irqsave(&lockres->l_lock, flags);
3515 lockres->l_flags |= OCFS2_LOCK_FREEING;
3516 if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) {
3517 /*
3518 * We know the downconvert is queued but not in progress
3519 * because we are the downconvert thread and processing
3520 * different lock. So we can just remove the lock from the
3521 * queue. This is not only an optimization but also a way
3522 * to avoid the following deadlock:
3523 * ocfs2_dentry_post_unlock()
3524 * ocfs2_dentry_lock_put()
3525 * ocfs2_drop_dentry_lock()
3526 * iput()
3527 * ocfs2_evict_inode()
3528 * ocfs2_clear_inode()
3529 * ocfs2_mark_lockres_freeing()
3530 * ... blocks waiting for OCFS2_LOCK_QUEUED
3531 * since we are the downconvert thread which
3532 * should clear the flag.
3533 */
3534 spin_unlock_irqrestore(&lockres->l_lock, flags);
3535 spin_lock_irqsave(&osb->dc_task_lock, flags2);
3536 list_del_init(&lockres->l_blocked_list);
3537 osb->blocked_lock_count--;
3538 spin_unlock_irqrestore(&osb->dc_task_lock, flags2);
3539 /*
3540 * Warn if we recurse into another post_unlock call. Strictly
3541 * speaking it isn't a problem but we need to be careful if
3542 * that happens (stack overflow, deadlocks, ...) so warn if
3543 * ocfs2 grows a path for which this can happen.
3544 */
3545 WARN_ON_ONCE(lockres->l_ops->post_unlock);
3546 /* Since the lock is freeing we don't do much in the fn below */
3547 ocfs2_process_blocked_lock(osb, lockres);
3548 return;
3549 }
3550 while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
3551 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
3552 spin_unlock_irqrestore(&lockres->l_lock, flags);
3553
3554 mlog(0, "Waiting on lockres %s\n", lockres->l_name);
3555
3556 status = ocfs2_wait_for_mask(&mw);
3557 if (status)
3558 mlog_errno(status);
3559
3560 spin_lock_irqsave(&lockres->l_lock, flags);
3561 }
3562 spin_unlock_irqrestore(&lockres->l_lock, flags);
3563}
3564
3565void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
3566 struct ocfs2_lock_res *lockres)
3567{
3568 int ret;
3569
3570 ocfs2_mark_lockres_freeing(osb, lockres);
3571 ret = ocfs2_drop_lock(osb, lockres);
3572 if (ret)
3573 mlog_errno(ret);
3574}
3575
3576static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
3577{
3578 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
3579 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
3580 ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
3581 ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
3582}
3583
3584int ocfs2_drop_inode_locks(struct inode *inode)
3585{
3586 int status, err;
3587
3588 /* No need to call ocfs2_mark_lockres_freeing here -
3589 * ocfs2_clear_inode has done it for us. */
3590
3591 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3592 &OCFS2_I(inode)->ip_open_lockres);
3593 if (err < 0)
3594 mlog_errno(err);
3595
3596 status = err;
3597
3598 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3599 &OCFS2_I(inode)->ip_inode_lockres);
3600 if (err < 0)
3601 mlog_errno(err);
3602 if (err < 0 && !status)
3603 status = err;
3604
3605 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3606 &OCFS2_I(inode)->ip_rw_lockres);
3607 if (err < 0)
3608 mlog_errno(err);
3609 if (err < 0 && !status)
3610 status = err;
3611
3612 return status;
3613}
3614
3615static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
3616 int new_level)
3617{
3618 assert_spin_locked(&lockres->l_lock);
3619
3620 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
3621
3622 if (lockres->l_level <= new_level) {
3623 mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
3624 "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
3625 "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
3626 new_level, list_empty(&lockres->l_blocked_list),
3627 list_empty(&lockres->l_mask_waiters), lockres->l_type,
3628 lockres->l_flags, lockres->l_ro_holders,
3629 lockres->l_ex_holders, lockres->l_action,
3630 lockres->l_unlock_action, lockres->l_requested,
3631 lockres->l_blocking, lockres->l_pending_gen);
3632 BUG();
3633 }
3634
3635 mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
3636 lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
3637
3638 lockres->l_action = OCFS2_AST_DOWNCONVERT;
3639 lockres->l_requested = new_level;
3640 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3641 return lockres_set_pending(lockres);
3642}
3643
3644static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
3645 struct ocfs2_lock_res *lockres,
3646 int new_level,
3647 int lvb,
3648 unsigned int generation)
3649{
3650 int ret;
3651 u32 dlm_flags = DLM_LKF_CONVERT;
3652
3653 mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
3654 lockres->l_level, new_level);
3655
3656 /*
3657 * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always
3658 * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that
3659 * we can recover correctly from node failure. Otherwise, we may get
3660 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set.
3661 */
3662 if (ocfs2_userspace_stack(osb) &&
3663 lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3664 lvb = 1;
3665
3666 if (lvb)
3667 dlm_flags |= DLM_LKF_VALBLK;
3668
3669 ret = ocfs2_dlm_lock(osb->cconn,
3670 new_level,
3671 &lockres->l_lksb,
3672 dlm_flags,
3673 lockres->l_name,
3674 OCFS2_LOCK_ID_MAX_LEN - 1);
3675 lockres_clear_pending(lockres, generation, osb);
3676 if (ret) {
3677 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
3678 ocfs2_recover_from_dlm_error(lockres, 1);
3679 goto bail;
3680 }
3681
3682 ret = 0;
3683bail:
3684 return ret;
3685}
3686
3687/* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */
3688static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
3689 struct ocfs2_lock_res *lockres)
3690{
3691 assert_spin_locked(&lockres->l_lock);
3692
3693 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
3694 /* If we're already trying to cancel a lock conversion
3695 * then just drop the spinlock and allow the caller to
3696 * requeue this lock. */
3697 mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
3698 return 0;
3699 }
3700
3701 /* were we in a convert when we got the bast fire? */
3702 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
3703 lockres->l_action != OCFS2_AST_DOWNCONVERT);
3704 /* set things up for the unlockast to know to just
3705 * clear out the ast_action and unset busy, etc. */
3706 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
3707
3708 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
3709 "lock %s, invalid flags: 0x%lx\n",
3710 lockres->l_name, lockres->l_flags);
3711
3712 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3713
3714 return 1;
3715}
3716
3717static int ocfs2_cancel_convert(struct ocfs2_super *osb,
3718 struct ocfs2_lock_res *lockres)
3719{
3720 int ret;
3721
3722 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
3723 DLM_LKF_CANCEL);
3724 if (ret) {
3725 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3726 ocfs2_recover_from_dlm_error(lockres, 0);
3727 }
3728
3729 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3730
3731 return ret;
3732}
3733
3734static int ocfs2_unblock_lock(struct ocfs2_super *osb,
3735 struct ocfs2_lock_res *lockres,
3736 struct ocfs2_unblock_ctl *ctl)
3737{
3738 unsigned long flags;
3739 int blocking;
3740 int new_level;
3741 int level;
3742 int ret = 0;
3743 int set_lvb = 0;
3744 unsigned int gen;
3745
3746 spin_lock_irqsave(&lockres->l_lock, flags);
3747
3748recheck:
3749 /*
3750 * Is it still blocking? If not, we have no more work to do.
3751 */
3752 if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
3753 BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
3754 spin_unlock_irqrestore(&lockres->l_lock, flags);
3755 ret = 0;
3756 goto leave;
3757 }
3758
3759 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
3760 /* XXX
3761 * This is a *big* race. The OCFS2_LOCK_PENDING flag
3762 * exists entirely for one reason - another thread has set
3763 * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock().
3764 *
3765 * If we do ocfs2_cancel_convert() before the other thread
3766 * calls dlm_lock(), our cancel will do nothing. We will
3767 * get no ast, and we will have no way of knowing the
3768 * cancel failed. Meanwhile, the other thread will call
3769 * into dlm_lock() and wait...forever.
3770 *
3771 * Why forever? Because another node has asked for the
3772 * lock first; that's why we're here in unblock_lock().
3773 *
3774 * The solution is OCFS2_LOCK_PENDING. When PENDING is
3775 * set, we just requeue the unblock. Only when the other
3776 * thread has called dlm_lock() and cleared PENDING will
3777 * we then cancel their request.
3778 *
3779 * All callers of dlm_lock() must set OCFS2_DLM_PENDING
3780 * at the same time they set OCFS2_DLM_BUSY. They must
3781 * clear OCFS2_DLM_PENDING after dlm_lock() returns.
3782 */
3783 if (lockres->l_flags & OCFS2_LOCK_PENDING) {
3784 mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
3785 lockres->l_name);
3786 goto leave_requeue;
3787 }
3788
3789 ctl->requeue = 1;
3790 ret = ocfs2_prepare_cancel_convert(osb, lockres);
3791 spin_unlock_irqrestore(&lockres->l_lock, flags);
3792 if (ret) {
3793 ret = ocfs2_cancel_convert(osb, lockres);
3794 if (ret < 0)
3795 mlog_errno(ret);
3796 }
3797 goto leave;
3798 }
3799
3800 /*
3801 * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is
3802 * set when the ast is received for an upconvert just before the
3803 * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast
3804 * on the heels of the ast, we want to delay the downconvert just
3805 * enough to allow the up requestor to do its task. Because this
3806 * lock is in the blocked queue, the lock will be downconverted
3807 * as soon as the requestor is done with the lock.
3808 */
3809 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING)
3810 goto leave_requeue;
3811
3812 /*
3813 * How can we block and yet be at NL? We were trying to upconvert
3814 * from NL and got canceled. The code comes back here, and now
3815 * we notice and clear BLOCKING.
3816 */
3817 if (lockres->l_level == DLM_LOCK_NL) {
3818 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
3819 mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
3820 lockres->l_blocking = DLM_LOCK_NL;
3821 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
3822 spin_unlock_irqrestore(&lockres->l_lock, flags);
3823 goto leave;
3824 }
3825
3826 /* if we're blocking an exclusive and we have *any* holders,
3827 * then requeue. */
3828 if ((lockres->l_blocking == DLM_LOCK_EX)
3829 && (lockres->l_ex_holders || lockres->l_ro_holders)) {
3830 mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
3831 lockres->l_name, lockres->l_ex_holders,
3832 lockres->l_ro_holders);
3833 goto leave_requeue;
3834 }
3835
3836 /* If it's a PR we're blocking, then only
3837 * requeue if we've got any EX holders */
3838 if (lockres->l_blocking == DLM_LOCK_PR &&
3839 lockres->l_ex_holders) {
3840 mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
3841 lockres->l_name, lockres->l_ex_holders);
3842 goto leave_requeue;
3843 }
3844
3845 /*
3846 * Can we get a lock in this state if the holder counts are
3847 * zero? The meta data unblock code used to check this.
3848 */
3849 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
3850 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
3851 mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
3852 lockres->l_name);
3853 goto leave_requeue;
3854 }
3855
3856 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
3857
3858 if (lockres->l_ops->check_downconvert
3859 && !lockres->l_ops->check_downconvert(lockres, new_level)) {
3860 mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
3861 lockres->l_name);
3862 goto leave_requeue;
3863 }
3864
3865 /* If we get here, then we know that there are no more
3866 * incompatible holders (and anyone asking for an incompatible
3867 * lock is blocked). We can now downconvert the lock */
3868 if (!lockres->l_ops->downconvert_worker)
3869 goto downconvert;
3870
3871 /* Some lockres types want to do a bit of work before
3872 * downconverting a lock. Allow that here. The worker function
3873 * may sleep, so we save off a copy of what we're blocking as
3874 * it may change while we're not holding the spin lock. */
3875 blocking = lockres->l_blocking;
3876 level = lockres->l_level;
3877 spin_unlock_irqrestore(&lockres->l_lock, flags);
3878
3879 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
3880
3881 if (ctl->unblock_action == UNBLOCK_STOP_POST) {
3882 mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
3883 lockres->l_name);
3884 goto leave;
3885 }
3886
3887 spin_lock_irqsave(&lockres->l_lock, flags);
3888 if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
3889 /* If this changed underneath us, then we can't drop
3890 * it just yet. */
3891 mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
3892 "Recheck\n", lockres->l_name, blocking,
3893 lockres->l_blocking, level, lockres->l_level);
3894 goto recheck;
3895 }
3896
3897downconvert:
3898 ctl->requeue = 0;
3899
3900 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3901 if (lockres->l_level == DLM_LOCK_EX)
3902 set_lvb = 1;
3903
3904 /*
3905 * We only set the lvb if the lock has been fully
3906 * refreshed - otherwise we risk setting stale
3907 * data. Otherwise, there's no need to actually clear
3908 * out the lvb here as it's value is still valid.
3909 */
3910 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3911 lockres->l_ops->set_lvb(lockres);
3912 }
3913
3914 gen = ocfs2_prepare_downconvert(lockres, new_level);
3915 spin_unlock_irqrestore(&lockres->l_lock, flags);
3916 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
3917 gen);
3918 /* The dlm lock convert is being cancelled in background,
3919 * ocfs2_cancel_convert() is asynchronous in fs/dlm,
3920 * requeue it, try again later.
3921 */
3922 if (ret == -EBUSY) {
3923 ctl->requeue = 1;
3924 mlog(ML_BASTS, "lockres %s, ReQ: Downconvert busy\n",
3925 lockres->l_name);
3926 ret = 0;
3927 msleep(20);
3928 }
3929
3930leave:
3931 if (ret)
3932 mlog_errno(ret);
3933 return ret;
3934
3935leave_requeue:
3936 spin_unlock_irqrestore(&lockres->l_lock, flags);
3937 ctl->requeue = 1;
3938
3939 return 0;
3940}
3941
3942static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
3943 int blocking)
3944{
3945 struct inode *inode;
3946 struct address_space *mapping;
3947 struct ocfs2_inode_info *oi;
3948
3949 inode = ocfs2_lock_res_inode(lockres);
3950 mapping = inode->i_mapping;
3951
3952 if (S_ISDIR(inode->i_mode)) {
3953 oi = OCFS2_I(inode);
3954 oi->ip_dir_lock_gen++;
3955 mlog(0, "generation: %u\n", oi->ip_dir_lock_gen);
3956 goto out_forget;
3957 }
3958
3959 if (!S_ISREG(inode->i_mode))
3960 goto out;
3961
3962 /*
3963 * We need this before the filemap_fdatawrite() so that it can
3964 * transfer the dirty bit from the PTE to the
3965 * page. Unfortunately this means that even for EX->PR
3966 * downconverts, we'll lose our mappings and have to build
3967 * them up again.
3968 */
3969 unmap_mapping_range(mapping, 0, 0, 0);
3970
3971 if (filemap_fdatawrite(mapping)) {
3972 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
3973 (unsigned long long)OCFS2_I(inode)->ip_blkno);
3974 }
3975 sync_mapping_buffers(mapping);
3976 if (blocking == DLM_LOCK_EX) {
3977 truncate_inode_pages(mapping, 0);
3978 } else {
3979 /* We only need to wait on the I/O if we're not also
3980 * truncating pages because truncate_inode_pages waits
3981 * for us above. We don't truncate pages if we're
3982 * blocking anything < EXMODE because we want to keep
3983 * them around in that case. */
3984 filemap_fdatawait(mapping);
3985 }
3986
3987out_forget:
3988 forget_all_cached_acls(inode);
3989
3990out:
3991 return UNBLOCK_CONTINUE;
3992}
3993
3994static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci,
3995 struct ocfs2_lock_res *lockres,
3996 int new_level)
3997{
3998 int checkpointed = ocfs2_ci_fully_checkpointed(ci);
3999
4000 BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
4001 BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
4002
4003 if (checkpointed)
4004 return 1;
4005
4006 ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci)));
4007 return 0;
4008}
4009
4010static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
4011 int new_level)
4012{
4013 struct inode *inode = ocfs2_lock_res_inode(lockres);
4014
4015 return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level);
4016}
4017
4018static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
4019{
4020 struct inode *inode = ocfs2_lock_res_inode(lockres);
4021
4022 __ocfs2_stuff_meta_lvb(inode);
4023}
4024
4025/*
4026 * Does the final reference drop on our dentry lock. Right now this
4027 * happens in the downconvert thread, but we could choose to simplify the
4028 * dlmglue API and push these off to the ocfs2_wq in the future.
4029 */
4030static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
4031 struct ocfs2_lock_res *lockres)
4032{
4033 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
4034 ocfs2_dentry_lock_put(osb, dl);
4035}
4036
4037/*
4038 * d_delete() matching dentries before the lock downconvert.
4039 *
4040 * At this point, any process waiting to destroy the
4041 * dentry_lock due to last ref count is stopped by the
4042 * OCFS2_LOCK_QUEUED flag.
4043 *
4044 * We have two potential problems
4045 *
4046 * 1) If we do the last reference drop on our dentry_lock (via dput)
4047 * we'll wind up in ocfs2_release_dentry_lock(), waiting on
4048 * the downconvert to finish. Instead we take an elevated
4049 * reference and push the drop until after we've completed our
4050 * unblock processing.
4051 *
4052 * 2) There might be another process with a final reference,
4053 * waiting on us to finish processing. If this is the case, we
4054 * detect it and exit out - there's no more dentries anyway.
4055 */
4056static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
4057 int blocking)
4058{
4059 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
4060 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
4061 struct dentry *dentry;
4062 unsigned long flags;
4063 int extra_ref = 0;
4064
4065 /*
4066 * This node is blocking another node from getting a read
4067 * lock. This happens when we've renamed within a
4068 * directory. We've forced the other nodes to d_delete(), but
4069 * we never actually dropped our lock because it's still
4070 * valid. The downconvert code will retain a PR for this node,
4071 * so there's no further work to do.
4072 */
4073 if (blocking == DLM_LOCK_PR)
4074 return UNBLOCK_CONTINUE;
4075
4076 /*
4077 * Mark this inode as potentially orphaned. The code in
4078 * ocfs2_delete_inode() will figure out whether it actually
4079 * needs to be freed or not.
4080 */
4081 spin_lock(&oi->ip_lock);
4082 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
4083 spin_unlock(&oi->ip_lock);
4084
4085 /*
4086 * Yuck. We need to make sure however that the check of
4087 * OCFS2_LOCK_FREEING and the extra reference are atomic with
4088 * respect to a reference decrement or the setting of that
4089 * flag.
4090 */
4091 spin_lock_irqsave(&lockres->l_lock, flags);
4092 spin_lock(&dentry_attach_lock);
4093 if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
4094 && dl->dl_count) {
4095 dl->dl_count++;
4096 extra_ref = 1;
4097 }
4098 spin_unlock(&dentry_attach_lock);
4099 spin_unlock_irqrestore(&lockres->l_lock, flags);
4100
4101 mlog(0, "extra_ref = %d\n", extra_ref);
4102
4103 /*
4104 * We have a process waiting on us in ocfs2_dentry_iput(),
4105 * which means we can't have any more outstanding
4106 * aliases. There's no need to do any more work.
4107 */
4108 if (!extra_ref)
4109 return UNBLOCK_CONTINUE;
4110
4111 spin_lock(&dentry_attach_lock);
4112 while (1) {
4113 dentry = ocfs2_find_local_alias(dl->dl_inode,
4114 dl->dl_parent_blkno, 1);
4115 if (!dentry)
4116 break;
4117 spin_unlock(&dentry_attach_lock);
4118
4119 if (S_ISDIR(dl->dl_inode->i_mode))
4120 shrink_dcache_parent(dentry);
4121
4122 mlog(0, "d_delete(%pd);\n", dentry);
4123
4124 /*
4125 * The following dcache calls may do an
4126 * iput(). Normally we don't want that from the
4127 * downconverting thread, but in this case it's ok
4128 * because the requesting node already has an
4129 * exclusive lock on the inode, so it can't be queued
4130 * for a downconvert.
4131 */
4132 d_delete(dentry);
4133 dput(dentry);
4134
4135 spin_lock(&dentry_attach_lock);
4136 }
4137 spin_unlock(&dentry_attach_lock);
4138
4139 /*
4140 * If we are the last holder of this dentry lock, there is no
4141 * reason to downconvert so skip straight to the unlock.
4142 */
4143 if (dl->dl_count == 1)
4144 return UNBLOCK_STOP_POST;
4145
4146 return UNBLOCK_CONTINUE_POST;
4147}
4148
4149static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
4150 int new_level)
4151{
4152 struct ocfs2_refcount_tree *tree =
4153 ocfs2_lock_res_refcount_tree(lockres);
4154
4155 return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level);
4156}
4157
4158static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
4159 int blocking)
4160{
4161 struct ocfs2_refcount_tree *tree =
4162 ocfs2_lock_res_refcount_tree(lockres);
4163
4164 ocfs2_metadata_cache_purge(&tree->rf_ci);
4165
4166 return UNBLOCK_CONTINUE;
4167}
4168
4169static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
4170{
4171 struct ocfs2_qinfo_lvb *lvb;
4172 struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
4173 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
4174 oinfo->dqi_gi.dqi_type);
4175
4176 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
4177 lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
4178 lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
4179 lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
4180 lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
4181 lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
4182 lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
4183 lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
4184}
4185
4186void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
4187{
4188 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4189 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
4190 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4191
4192 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
4193 ocfs2_cluster_unlock(osb, lockres, level);
4194}
4195
4196static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
4197{
4198 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
4199 oinfo->dqi_gi.dqi_type);
4200 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4201 struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
4202 struct buffer_head *bh = NULL;
4203 struct ocfs2_global_disk_dqinfo *gdinfo;
4204 int status = 0;
4205
4206 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
4207 lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
4208 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
4209 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
4210 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
4211 oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
4212 oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
4213 oinfo->dqi_gi.dqi_free_entry =
4214 be32_to_cpu(lvb->lvb_free_entry);
4215 } else {
4216 status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode,
4217 oinfo->dqi_giblk, &bh);
4218 if (status) {
4219 mlog_errno(status);
4220 goto bail;
4221 }
4222 gdinfo = (struct ocfs2_global_disk_dqinfo *)
4223 (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
4224 info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
4225 info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
4226 oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
4227 oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
4228 oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
4229 oinfo->dqi_gi.dqi_free_entry =
4230 le32_to_cpu(gdinfo->dqi_free_entry);
4231 brelse(bh);
4232 ocfs2_track_lock_refresh(lockres);
4233 }
4234
4235bail:
4236 return status;
4237}
4238
4239/* Lock quota info, this function expects at least shared lock on the quota file
4240 * so that we can safely refresh quota info from disk. */
4241int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
4242{
4243 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4244 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
4245 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4246 int status = 0;
4247
4248 /* On RO devices, locking really isn't needed... */
4249 if (ocfs2_is_hard_readonly(osb)) {
4250 if (ex)
4251 status = -EROFS;
4252 goto bail;
4253 }
4254 if (ocfs2_mount_local(osb))
4255 goto bail;
4256
4257 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
4258 if (status < 0) {
4259 mlog_errno(status);
4260 goto bail;
4261 }
4262 if (!ocfs2_should_refresh_lock_res(lockres))
4263 goto bail;
4264 /* OK, we have the lock but we need to refresh the quota info */
4265 status = ocfs2_refresh_qinfo(oinfo);
4266 if (status)
4267 ocfs2_qinfo_unlock(oinfo, ex);
4268 ocfs2_complete_lock_res_refresh(lockres, status);
4269bail:
4270 return status;
4271}
4272
4273int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex)
4274{
4275 int status;
4276 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4277 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
4278 struct ocfs2_super *osb = lockres->l_priv;
4279
4280
4281 if (ocfs2_is_hard_readonly(osb))
4282 return -EROFS;
4283
4284 if (ocfs2_mount_local(osb))
4285 return 0;
4286
4287 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
4288 if (status < 0)
4289 mlog_errno(status);
4290
4291 return status;
4292}
4293
4294void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
4295{
4296 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4297 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
4298 struct ocfs2_super *osb = lockres->l_priv;
4299
4300 if (!ocfs2_mount_local(osb))
4301 ocfs2_cluster_unlock(osb, lockres, level);
4302}
4303
4304static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
4305 struct ocfs2_lock_res *lockres)
4306{
4307 int status;
4308 struct ocfs2_unblock_ctl ctl = {0, 0,};
4309 unsigned long flags;
4310
4311 /* Our reference to the lockres in this function can be
4312 * considered valid until we remove the OCFS2_LOCK_QUEUED
4313 * flag. */
4314
4315 BUG_ON(!lockres);
4316 BUG_ON(!lockres->l_ops);
4317
4318 mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
4319
4320 /* Detect whether a lock has been marked as going away while
4321 * the downconvert thread was processing other things. A lock can
4322 * still be marked with OCFS2_LOCK_FREEING after this check,
4323 * but short circuiting here will still save us some
4324 * performance. */
4325 spin_lock_irqsave(&lockres->l_lock, flags);
4326 if (lockres->l_flags & OCFS2_LOCK_FREEING)
4327 goto unqueue;
4328 spin_unlock_irqrestore(&lockres->l_lock, flags);
4329
4330 status = ocfs2_unblock_lock(osb, lockres, &ctl);
4331 if (status < 0)
4332 mlog_errno(status);
4333
4334 spin_lock_irqsave(&lockres->l_lock, flags);
4335unqueue:
4336 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
4337 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
4338 } else
4339 ocfs2_schedule_blocked_lock(osb, lockres);
4340
4341 mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
4342 ctl.requeue ? "yes" : "no");
4343 spin_unlock_irqrestore(&lockres->l_lock, flags);
4344
4345 if (ctl.unblock_action != UNBLOCK_CONTINUE
4346 && lockres->l_ops->post_unlock)
4347 lockres->l_ops->post_unlock(osb, lockres);
4348}
4349
4350static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
4351 struct ocfs2_lock_res *lockres)
4352{
4353 unsigned long flags;
4354
4355 assert_spin_locked(&lockres->l_lock);
4356
4357 if (lockres->l_flags & OCFS2_LOCK_FREEING) {
4358 /* Do not schedule a lock for downconvert when it's on
4359 * the way to destruction - any nodes wanting access
4360 * to the resource will get it soon. */
4361 mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
4362 lockres->l_name, lockres->l_flags);
4363 return;
4364 }
4365
4366 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
4367
4368 spin_lock_irqsave(&osb->dc_task_lock, flags);
4369 if (list_empty(&lockres->l_blocked_list)) {
4370 list_add_tail(&lockres->l_blocked_list,
4371 &osb->blocked_lock_list);
4372 osb->blocked_lock_count++;
4373 }
4374 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4375}
4376
4377static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
4378{
4379 unsigned long processed;
4380 unsigned long flags;
4381 struct ocfs2_lock_res *lockres;
4382
4383 spin_lock_irqsave(&osb->dc_task_lock, flags);
4384 /* grab this early so we know to try again if a state change and
4385 * wake happens part-way through our work */
4386 osb->dc_work_sequence = osb->dc_wake_sequence;
4387
4388 processed = osb->blocked_lock_count;
4389 /*
4390 * blocked lock processing in this loop might call iput which can
4391 * remove items off osb->blocked_lock_list. Downconvert up to
4392 * 'processed' number of locks, but stop short if we had some
4393 * removed in ocfs2_mark_lockres_freeing when downconverting.
4394 */
4395 while (processed && !list_empty(&osb->blocked_lock_list)) {
4396 lockres = list_entry(osb->blocked_lock_list.next,
4397 struct ocfs2_lock_res, l_blocked_list);
4398 list_del_init(&lockres->l_blocked_list);
4399 osb->blocked_lock_count--;
4400 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4401
4402 BUG_ON(!processed);
4403 processed--;
4404
4405 ocfs2_process_blocked_lock(osb, lockres);
4406
4407 spin_lock_irqsave(&osb->dc_task_lock, flags);
4408 }
4409 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4410}
4411
4412static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
4413{
4414 int empty = 0;
4415 unsigned long flags;
4416
4417 spin_lock_irqsave(&osb->dc_task_lock, flags);
4418 if (list_empty(&osb->blocked_lock_list))
4419 empty = 1;
4420
4421 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4422 return empty;
4423}
4424
4425static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
4426{
4427 int should_wake = 0;
4428 unsigned long flags;
4429
4430 spin_lock_irqsave(&osb->dc_task_lock, flags);
4431 if (osb->dc_work_sequence != osb->dc_wake_sequence)
4432 should_wake = 1;
4433 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4434
4435 return should_wake;
4436}
4437
4438static int ocfs2_downconvert_thread(void *arg)
4439{
4440 struct ocfs2_super *osb = arg;
4441
4442 /* only quit once we've been asked to stop and there is no more
4443 * work available */
4444 while (!(kthread_should_stop() &&
4445 ocfs2_downconvert_thread_lists_empty(osb))) {
4446
4447 wait_event_interruptible(osb->dc_event,
4448 ocfs2_downconvert_thread_should_wake(osb) ||
4449 kthread_should_stop());
4450
4451 mlog(0, "downconvert_thread: awoken\n");
4452
4453 ocfs2_downconvert_thread_do_work(osb);
4454 }
4455
4456 osb->dc_task = NULL;
4457 return 0;
4458}
4459
4460void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
4461{
4462 unsigned long flags;
4463
4464 spin_lock_irqsave(&osb->dc_task_lock, flags);
4465 /* make sure the voting thread gets a swipe at whatever changes
4466 * the caller may have made to the voting state */
4467 osb->dc_wake_sequence++;
4468 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4469 wake_up(&osb->dc_event);
4470}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * dlmglue.c
6 *
7 * Code which implements an OCFS2 specific interface to our DLM.
8 *
9 * Copyright (C) 2003, 2004 Oracle. All rights reserved.
10 */
11
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/highmem.h>
15#include <linux/mm.h>
16#include <linux/kthread.h>
17#include <linux/pagemap.h>
18#include <linux/debugfs.h>
19#include <linux/seq_file.h>
20#include <linux/time.h>
21#include <linux/quotaops.h>
22#include <linux/sched/signal.h>
23
24#define MLOG_MASK_PREFIX ML_DLM_GLUE
25#include <cluster/masklog.h>
26
27#include "ocfs2.h"
28#include "ocfs2_lockingver.h"
29
30#include "alloc.h"
31#include "dcache.h"
32#include "dlmglue.h"
33#include "extent_map.h"
34#include "file.h"
35#include "heartbeat.h"
36#include "inode.h"
37#include "journal.h"
38#include "stackglue.h"
39#include "slot_map.h"
40#include "super.h"
41#include "uptodate.h"
42#include "quota.h"
43#include "refcounttree.h"
44#include "acl.h"
45
46#include "buffer_head_io.h"
47
48struct ocfs2_mask_waiter {
49 struct list_head mw_item;
50 int mw_status;
51 struct completion mw_complete;
52 unsigned long mw_mask;
53 unsigned long mw_goal;
54#ifdef CONFIG_OCFS2_FS_STATS
55 ktime_t mw_lock_start;
56#endif
57};
58
59static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
60static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
61static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
62static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
63
64/*
65 * Return value from ->downconvert_worker functions.
66 *
67 * These control the precise actions of ocfs2_unblock_lock()
68 * and ocfs2_process_blocked_lock()
69 *
70 */
71enum ocfs2_unblock_action {
72 UNBLOCK_CONTINUE = 0, /* Continue downconvert */
73 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire
74 * ->post_unlock callback */
75 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire
76 * ->post_unlock() callback. */
77};
78
79struct ocfs2_unblock_ctl {
80 int requeue;
81 enum ocfs2_unblock_action unblock_action;
82};
83
84/* Lockdep class keys */
85#ifdef CONFIG_DEBUG_LOCK_ALLOC
86static struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
87#endif
88
89static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
90 int new_level);
91static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
92
93static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
94 int blocking);
95
96static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
97 int blocking);
98
99static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
100 struct ocfs2_lock_res *lockres);
101
102static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
103
104static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
105 int new_level);
106static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
107 int blocking);
108
109#define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
110
111/* This aids in debugging situations where a bad LVB might be involved. */
112static void ocfs2_dump_meta_lvb_info(u64 level,
113 const char *function,
114 unsigned int line,
115 struct ocfs2_lock_res *lockres)
116{
117 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
118
119 mlog(level, "LVB information for %s (called from %s:%u):\n",
120 lockres->l_name, function, line);
121 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n",
122 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters),
123 be32_to_cpu(lvb->lvb_igeneration));
124 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
125 (unsigned long long)be64_to_cpu(lvb->lvb_isize),
126 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
127 be16_to_cpu(lvb->lvb_imode));
128 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
129 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
130 (long long)be64_to_cpu(lvb->lvb_iatime_packed),
131 (long long)be64_to_cpu(lvb->lvb_ictime_packed),
132 (long long)be64_to_cpu(lvb->lvb_imtime_packed),
133 be32_to_cpu(lvb->lvb_iattr));
134}
135
136
137/*
138 * OCFS2 Lock Resource Operations
139 *
140 * These fine tune the behavior of the generic dlmglue locking infrastructure.
141 *
142 * The most basic of lock types can point ->l_priv to their respective
143 * struct ocfs2_super and allow the default actions to manage things.
144 *
145 * Right now, each lock type also needs to implement an init function,
146 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
147 * should be called when the lock is no longer needed (i.e., object
148 * destruction time).
149 */
150struct ocfs2_lock_res_ops {
151 /*
152 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
153 * this callback if ->l_priv is not an ocfs2_super pointer
154 */
155 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
156
157 /*
158 * Optionally called in the downconvert thread after a
159 * successful downconvert. The lockres will not be referenced
160 * after this callback is called, so it is safe to free
161 * memory, etc.
162 *
163 * The exact semantics of when this is called are controlled
164 * by ->downconvert_worker()
165 */
166 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
167
168 /*
169 * Allow a lock type to add checks to determine whether it is
170 * safe to downconvert a lock. Return 0 to re-queue the
171 * downconvert at a later time, nonzero to continue.
172 *
173 * For most locks, the default checks that there are no
174 * incompatible holders are sufficient.
175 *
176 * Called with the lockres spinlock held.
177 */
178 int (*check_downconvert)(struct ocfs2_lock_res *, int);
179
180 /*
181 * Allows a lock type to populate the lock value block. This
182 * is called on downconvert, and when we drop a lock.
183 *
184 * Locks that want to use this should set LOCK_TYPE_USES_LVB
185 * in the flags field.
186 *
187 * Called with the lockres spinlock held.
188 */
189 void (*set_lvb)(struct ocfs2_lock_res *);
190
191 /*
192 * Called from the downconvert thread when it is determined
193 * that a lock will be downconverted. This is called without
194 * any locks held so the function can do work that might
195 * schedule (syncing out data, etc).
196 *
197 * This should return any one of the ocfs2_unblock_action
198 * values, depending on what it wants the thread to do.
199 */
200 int (*downconvert_worker)(struct ocfs2_lock_res *, int);
201
202 /*
203 * LOCK_TYPE_* flags which describe the specific requirements
204 * of a lock type. Descriptions of each individual flag follow.
205 */
206 int flags;
207};
208
209/*
210 * Some locks want to "refresh" potentially stale data when a
211 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this
212 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the
213 * individual lockres l_flags member from the ast function. It is
214 * expected that the locking wrapper will clear the
215 * OCFS2_LOCK_NEEDS_REFRESH flag when done.
216 */
217#define LOCK_TYPE_REQUIRES_REFRESH 0x1
218
219/*
220 * Indicate that a lock type makes use of the lock value block. The
221 * ->set_lvb lock type callback must be defined.
222 */
223#define LOCK_TYPE_USES_LVB 0x2
224
225static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
226 .get_osb = ocfs2_get_inode_osb,
227 .flags = 0,
228};
229
230static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
231 .get_osb = ocfs2_get_inode_osb,
232 .check_downconvert = ocfs2_check_meta_downconvert,
233 .set_lvb = ocfs2_set_meta_lvb,
234 .downconvert_worker = ocfs2_data_convert_worker,
235 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
236};
237
238static struct ocfs2_lock_res_ops ocfs2_super_lops = {
239 .flags = LOCK_TYPE_REQUIRES_REFRESH,
240};
241
242static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
243 .flags = 0,
244};
245
246static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
247 .flags = 0,
248};
249
250static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
251 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
252};
253
254static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
255 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
256};
257
258static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
259 .get_osb = ocfs2_get_dentry_osb,
260 .post_unlock = ocfs2_dentry_post_unlock,
261 .downconvert_worker = ocfs2_dentry_convert_worker,
262 .flags = 0,
263};
264
265static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
266 .get_osb = ocfs2_get_inode_osb,
267 .flags = 0,
268};
269
270static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
271 .get_osb = ocfs2_get_file_osb,
272 .flags = 0,
273};
274
275static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
276 .set_lvb = ocfs2_set_qinfo_lvb,
277 .get_osb = ocfs2_get_qinfo_osb,
278 .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
279};
280
281static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
282 .check_downconvert = ocfs2_check_refcount_downconvert,
283 .downconvert_worker = ocfs2_refcount_convert_worker,
284 .flags = 0,
285};
286
287static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
288{
289 return lockres->l_type == OCFS2_LOCK_TYPE_META ||
290 lockres->l_type == OCFS2_LOCK_TYPE_RW ||
291 lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
292}
293
294static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb)
295{
296 return container_of(lksb, struct ocfs2_lock_res, l_lksb);
297}
298
299static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
300{
301 BUG_ON(!ocfs2_is_inode_lock(lockres));
302
303 return (struct inode *) lockres->l_priv;
304}
305
306static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
307{
308 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
309
310 return (struct ocfs2_dentry_lock *)lockres->l_priv;
311}
312
313static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
314{
315 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
316
317 return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
318}
319
320static inline struct ocfs2_refcount_tree *
321ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res)
322{
323 return container_of(res, struct ocfs2_refcount_tree, rf_lockres);
324}
325
326static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
327{
328 if (lockres->l_ops->get_osb)
329 return lockres->l_ops->get_osb(lockres);
330
331 return (struct ocfs2_super *)lockres->l_priv;
332}
333
334static int ocfs2_lock_create(struct ocfs2_super *osb,
335 struct ocfs2_lock_res *lockres,
336 int level,
337 u32 dlm_flags);
338static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
339 int wanted);
340static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
341 struct ocfs2_lock_res *lockres,
342 int level, unsigned long caller_ip);
343static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb,
344 struct ocfs2_lock_res *lockres,
345 int level)
346{
347 __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_);
348}
349
350static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
351static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
352static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
353static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
354static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
355 struct ocfs2_lock_res *lockres);
356static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
357 int convert);
358#define ocfs2_log_dlm_error(_func, _err, _lockres) do { \
359 if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \
360 mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \
361 _err, _func, _lockres->l_name); \
362 else \
363 mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \
364 _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \
365 (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \
366} while (0)
367static int ocfs2_downconvert_thread(void *arg);
368static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
369 struct ocfs2_lock_res *lockres);
370static int ocfs2_inode_lock_update(struct inode *inode,
371 struct buffer_head **bh);
372static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
373static inline int ocfs2_highest_compat_lock_level(int level);
374static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
375 int new_level);
376static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
377 struct ocfs2_lock_res *lockres,
378 int new_level,
379 int lvb,
380 unsigned int generation);
381static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
382 struct ocfs2_lock_res *lockres);
383static int ocfs2_cancel_convert(struct ocfs2_super *osb,
384 struct ocfs2_lock_res *lockres);
385
386
387static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
388 u64 blkno,
389 u32 generation,
390 char *name)
391{
392 int len;
393
394 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
395
396 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
397 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
398 (long long)blkno, generation);
399
400 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
401
402 mlog(0, "built lock resource with name: %s\n", name);
403}
404
405static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
406
407static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
408 struct ocfs2_dlm_debug *dlm_debug)
409{
410 mlog(0, "Add tracking for lockres %s\n", res->l_name);
411
412 spin_lock(&ocfs2_dlm_tracking_lock);
413 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
414 spin_unlock(&ocfs2_dlm_tracking_lock);
415}
416
417static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
418{
419 spin_lock(&ocfs2_dlm_tracking_lock);
420 if (!list_empty(&res->l_debug_list))
421 list_del_init(&res->l_debug_list);
422 spin_unlock(&ocfs2_dlm_tracking_lock);
423}
424
425#ifdef CONFIG_OCFS2_FS_STATS
426static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
427{
428 res->l_lock_refresh = 0;
429 res->l_lock_wait = 0;
430 memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats));
431 memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats));
432}
433
434static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level,
435 struct ocfs2_mask_waiter *mw, int ret)
436{
437 u32 usec;
438 ktime_t kt;
439 struct ocfs2_lock_stats *stats;
440
441 if (level == LKM_PRMODE)
442 stats = &res->l_lock_prmode;
443 else if (level == LKM_EXMODE)
444 stats = &res->l_lock_exmode;
445 else
446 return;
447
448 kt = ktime_sub(ktime_get(), mw->mw_lock_start);
449 usec = ktime_to_us(kt);
450
451 stats->ls_gets++;
452 stats->ls_total += ktime_to_ns(kt);
453 /* overflow */
454 if (unlikely(stats->ls_gets == 0)) {
455 stats->ls_gets++;
456 stats->ls_total = ktime_to_ns(kt);
457 }
458
459 if (stats->ls_max < usec)
460 stats->ls_max = usec;
461
462 if (ret)
463 stats->ls_fail++;
464
465 stats->ls_last = ktime_to_us(ktime_get_real());
466}
467
468static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
469{
470 lockres->l_lock_refresh++;
471}
472
473static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres)
474{
475 struct ocfs2_mask_waiter *mw;
476
477 if (list_empty(&lockres->l_mask_waiters)) {
478 lockres->l_lock_wait = 0;
479 return;
480 }
481
482 mw = list_first_entry(&lockres->l_mask_waiters,
483 struct ocfs2_mask_waiter, mw_item);
484 lockres->l_lock_wait =
485 ktime_to_us(ktime_mono_to_real(mw->mw_lock_start));
486}
487
488static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
489{
490 mw->mw_lock_start = ktime_get();
491}
492#else
493static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
494{
495}
496static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res,
497 int level, struct ocfs2_mask_waiter *mw, int ret)
498{
499}
500static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
501{
502}
503static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres)
504{
505}
506static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
507{
508}
509#endif
510
511static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
512 struct ocfs2_lock_res *res,
513 enum ocfs2_lock_type type,
514 struct ocfs2_lock_res_ops *ops,
515 void *priv)
516{
517 res->l_type = type;
518 res->l_ops = ops;
519 res->l_priv = priv;
520
521 res->l_level = DLM_LOCK_IV;
522 res->l_requested = DLM_LOCK_IV;
523 res->l_blocking = DLM_LOCK_IV;
524 res->l_action = OCFS2_AST_INVALID;
525 res->l_unlock_action = OCFS2_UNLOCK_INVALID;
526
527 res->l_flags = OCFS2_LOCK_INITIALIZED;
528
529 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
530
531 ocfs2_init_lock_stats(res);
532#ifdef CONFIG_DEBUG_LOCK_ALLOC
533 if (type != OCFS2_LOCK_TYPE_OPEN)
534 lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type],
535 &lockdep_keys[type], 0);
536 else
537 res->l_lockdep_map.key = NULL;
538#endif
539}
540
541void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
542{
543 /* This also clears out the lock status block */
544 memset(res, 0, sizeof(struct ocfs2_lock_res));
545 spin_lock_init(&res->l_lock);
546 init_waitqueue_head(&res->l_event);
547 INIT_LIST_HEAD(&res->l_blocked_list);
548 INIT_LIST_HEAD(&res->l_mask_waiters);
549 INIT_LIST_HEAD(&res->l_holders);
550}
551
552void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
553 enum ocfs2_lock_type type,
554 unsigned int generation,
555 struct inode *inode)
556{
557 struct ocfs2_lock_res_ops *ops;
558
559 switch(type) {
560 case OCFS2_LOCK_TYPE_RW:
561 ops = &ocfs2_inode_rw_lops;
562 break;
563 case OCFS2_LOCK_TYPE_META:
564 ops = &ocfs2_inode_inode_lops;
565 break;
566 case OCFS2_LOCK_TYPE_OPEN:
567 ops = &ocfs2_inode_open_lops;
568 break;
569 default:
570 mlog_bug_on_msg(1, "type: %d\n", type);
571 ops = NULL; /* thanks, gcc */
572 break;
573 }
574
575 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
576 generation, res->l_name);
577 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
578}
579
580static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
581{
582 struct inode *inode = ocfs2_lock_res_inode(lockres);
583
584 return OCFS2_SB(inode->i_sb);
585}
586
587static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
588{
589 struct ocfs2_mem_dqinfo *info = lockres->l_priv;
590
591 return OCFS2_SB(info->dqi_gi.dqi_sb);
592}
593
594static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
595{
596 struct ocfs2_file_private *fp = lockres->l_priv;
597
598 return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
599}
600
601static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
602{
603 __be64 inode_blkno_be;
604
605 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
606 sizeof(__be64));
607
608 return be64_to_cpu(inode_blkno_be);
609}
610
611static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
612{
613 struct ocfs2_dentry_lock *dl = lockres->l_priv;
614
615 return OCFS2_SB(dl->dl_inode->i_sb);
616}
617
618void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
619 u64 parent, struct inode *inode)
620{
621 int len;
622 u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
623 __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
624 struct ocfs2_lock_res *lockres = &dl->dl_lockres;
625
626 ocfs2_lock_res_init_once(lockres);
627
628 /*
629 * Unfortunately, the standard lock naming scheme won't work
630 * here because we have two 16 byte values to use. Instead,
631 * we'll stuff the inode number as a binary value. We still
632 * want error prints to show something without garbling the
633 * display, so drop a null byte in there before the inode
634 * number. A future version of OCFS2 will likely use all
635 * binary lock names. The stringified names have been a
636 * tremendous aid in debugging, but now that the debugfs
637 * interface exists, we can mangle things there if need be.
638 *
639 * NOTE: We also drop the standard "pad" value (the total lock
640 * name size stays the same though - the last part is all
641 * zeros due to the memset in ocfs2_lock_res_init_once()
642 */
643 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
644 "%c%016llx",
645 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
646 (long long)parent);
647
648 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
649
650 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
651 sizeof(__be64));
652
653 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
654 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
655 dl);
656}
657
658static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
659 struct ocfs2_super *osb)
660{
661 /* Superblock lockres doesn't come from a slab so we call init
662 * once on it manually. */
663 ocfs2_lock_res_init_once(res);
664 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
665 0, res->l_name);
666 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
667 &ocfs2_super_lops, osb);
668}
669
670static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
671 struct ocfs2_super *osb)
672{
673 /* Rename lockres doesn't come from a slab so we call init
674 * once on it manually. */
675 ocfs2_lock_res_init_once(res);
676 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
677 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
678 &ocfs2_rename_lops, osb);
679}
680
681static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
682 struct ocfs2_super *osb)
683{
684 /* nfs_sync lockres doesn't come from a slab so we call init
685 * once on it manually. */
686 ocfs2_lock_res_init_once(res);
687 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
688 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
689 &ocfs2_nfs_sync_lops, osb);
690}
691
692static void ocfs2_nfs_sync_lock_init(struct ocfs2_super *osb)
693{
694 ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
695 init_rwsem(&osb->nfs_sync_rwlock);
696}
697
698void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb)
699{
700 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
701
702 /* Only one trimfs thread are allowed to work at the same time. */
703 mutex_lock(&osb->obs_trim_fs_mutex);
704
705 ocfs2_lock_res_init_once(lockres);
706 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name);
707 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS,
708 &ocfs2_trim_fs_lops, osb);
709}
710
711void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb)
712{
713 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
714
715 ocfs2_simple_drop_lockres(osb, lockres);
716 ocfs2_lock_res_free(lockres);
717
718 mutex_unlock(&osb->obs_trim_fs_mutex);
719}
720
721static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
722 struct ocfs2_super *osb)
723{
724 ocfs2_lock_res_init_once(res);
725 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
726 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
727 &ocfs2_orphan_scan_lops, osb);
728}
729
730void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
731 struct ocfs2_file_private *fp)
732{
733 struct inode *inode = fp->fp_file->f_mapping->host;
734 struct ocfs2_inode_info *oi = OCFS2_I(inode);
735
736 ocfs2_lock_res_init_once(lockres);
737 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
738 inode->i_generation, lockres->l_name);
739 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
740 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
741 fp);
742 lockres->l_flags |= OCFS2_LOCK_NOCACHE;
743}
744
745void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
746 struct ocfs2_mem_dqinfo *info)
747{
748 ocfs2_lock_res_init_once(lockres);
749 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
750 0, lockres->l_name);
751 ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
752 OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
753 info);
754}
755
756void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
757 struct ocfs2_super *osb, u64 ref_blkno,
758 unsigned int generation)
759{
760 ocfs2_lock_res_init_once(lockres);
761 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno,
762 generation, lockres->l_name);
763 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT,
764 &ocfs2_refcount_block_lops, osb);
765}
766
767void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
768{
769 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
770 return;
771
772 ocfs2_remove_lockres_tracking(res);
773
774 mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
775 "Lockres %s is on the blocked list\n",
776 res->l_name);
777 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
778 "Lockres %s has mask waiters pending\n",
779 res->l_name);
780 mlog_bug_on_msg(spin_is_locked(&res->l_lock),
781 "Lockres %s is locked\n",
782 res->l_name);
783 mlog_bug_on_msg(res->l_ro_holders,
784 "Lockres %s has %u ro holders\n",
785 res->l_name, res->l_ro_holders);
786 mlog_bug_on_msg(res->l_ex_holders,
787 "Lockres %s has %u ex holders\n",
788 res->l_name, res->l_ex_holders);
789
790 /* Need to clear out the lock status block for the dlm */
791 memset(&res->l_lksb, 0, sizeof(res->l_lksb));
792
793 res->l_flags = 0UL;
794}
795
796/*
797 * Keep a list of processes who have interest in a lockres.
798 * Note: this is now only uesed for check recursive cluster locking.
799 */
800static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres,
801 struct ocfs2_lock_holder *oh)
802{
803 INIT_LIST_HEAD(&oh->oh_list);
804 oh->oh_owner_pid = get_pid(task_pid(current));
805
806 spin_lock(&lockres->l_lock);
807 list_add_tail(&oh->oh_list, &lockres->l_holders);
808 spin_unlock(&lockres->l_lock);
809}
810
811static struct ocfs2_lock_holder *
812ocfs2_pid_holder(struct ocfs2_lock_res *lockres,
813 struct pid *pid)
814{
815 struct ocfs2_lock_holder *oh;
816
817 spin_lock(&lockres->l_lock);
818 list_for_each_entry(oh, &lockres->l_holders, oh_list) {
819 if (oh->oh_owner_pid == pid) {
820 spin_unlock(&lockres->l_lock);
821 return oh;
822 }
823 }
824 spin_unlock(&lockres->l_lock);
825 return NULL;
826}
827
828static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres,
829 struct ocfs2_lock_holder *oh)
830{
831 spin_lock(&lockres->l_lock);
832 list_del(&oh->oh_list);
833 spin_unlock(&lockres->l_lock);
834
835 put_pid(oh->oh_owner_pid);
836}
837
838
839static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
840 int level)
841{
842 BUG_ON(!lockres);
843
844 switch(level) {
845 case DLM_LOCK_EX:
846 lockres->l_ex_holders++;
847 break;
848 case DLM_LOCK_PR:
849 lockres->l_ro_holders++;
850 break;
851 default:
852 BUG();
853 }
854}
855
856static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
857 int level)
858{
859 BUG_ON(!lockres);
860
861 switch(level) {
862 case DLM_LOCK_EX:
863 BUG_ON(!lockres->l_ex_holders);
864 lockres->l_ex_holders--;
865 break;
866 case DLM_LOCK_PR:
867 BUG_ON(!lockres->l_ro_holders);
868 lockres->l_ro_holders--;
869 break;
870 default:
871 BUG();
872 }
873}
874
875/* WARNING: This function lives in a world where the only three lock
876 * levels are EX, PR, and NL. It *will* have to be adjusted when more
877 * lock types are added. */
878static inline int ocfs2_highest_compat_lock_level(int level)
879{
880 int new_level = DLM_LOCK_EX;
881
882 if (level == DLM_LOCK_EX)
883 new_level = DLM_LOCK_NL;
884 else if (level == DLM_LOCK_PR)
885 new_level = DLM_LOCK_PR;
886 return new_level;
887}
888
889static void lockres_set_flags(struct ocfs2_lock_res *lockres,
890 unsigned long newflags)
891{
892 struct ocfs2_mask_waiter *mw, *tmp;
893
894 assert_spin_locked(&lockres->l_lock);
895
896 lockres->l_flags = newflags;
897
898 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
899 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
900 continue;
901
902 list_del_init(&mw->mw_item);
903 mw->mw_status = 0;
904 complete(&mw->mw_complete);
905 ocfs2_track_lock_wait(lockres);
906 }
907}
908static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
909{
910 lockres_set_flags(lockres, lockres->l_flags | or);
911}
912static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
913 unsigned long clear)
914{
915 lockres_set_flags(lockres, lockres->l_flags & ~clear);
916}
917
918static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
919{
920 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
921 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
922 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
923 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
924
925 lockres->l_level = lockres->l_requested;
926 if (lockres->l_level <=
927 ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
928 lockres->l_blocking = DLM_LOCK_NL;
929 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
930 }
931 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
932}
933
934static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
935{
936 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
937 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
938
939 /* Convert from RO to EX doesn't really need anything as our
940 * information is already up to data. Convert from NL to
941 * *anything* however should mark ourselves as needing an
942 * update */
943 if (lockres->l_level == DLM_LOCK_NL &&
944 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
945 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
946
947 lockres->l_level = lockres->l_requested;
948
949 /*
950 * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing
951 * the OCFS2_LOCK_BUSY flag to prevent the dc thread from
952 * downconverting the lock before the upconvert has fully completed.
953 * Do not prevent the dc thread from downconverting if NONBLOCK lock
954 * had already returned.
955 */
956 if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED))
957 lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
958 else
959 lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED);
960
961 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
962}
963
964static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
965{
966 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
967 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
968
969 if (lockres->l_requested > DLM_LOCK_NL &&
970 !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
971 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
972 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
973
974 lockres->l_level = lockres->l_requested;
975 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
976 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
977}
978
979static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
980 int level)
981{
982 int needs_downconvert = 0;
983
984 assert_spin_locked(&lockres->l_lock);
985
986 if (level > lockres->l_blocking) {
987 /* only schedule a downconvert if we haven't already scheduled
988 * one that goes low enough to satisfy the level we're
989 * blocking. this also catches the case where we get
990 * duplicate BASTs */
991 if (ocfs2_highest_compat_lock_level(level) <
992 ocfs2_highest_compat_lock_level(lockres->l_blocking))
993 needs_downconvert = 1;
994
995 lockres->l_blocking = level;
996 }
997
998 mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
999 lockres->l_name, level, lockres->l_level, lockres->l_blocking,
1000 needs_downconvert);
1001
1002 if (needs_downconvert)
1003 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
1004 mlog(0, "needs_downconvert = %d\n", needs_downconvert);
1005 return needs_downconvert;
1006}
1007
1008/*
1009 * OCFS2_LOCK_PENDING and l_pending_gen.
1010 *
1011 * Why does OCFS2_LOCK_PENDING exist? To close a race between setting
1012 * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock()
1013 * for more details on the race.
1014 *
1015 * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces
1016 * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock()
1017 * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear
1018 * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns,
1019 * the caller is going to try to clear PENDING again. If nothing else is
1020 * happening, __lockres_clear_pending() sees PENDING is unset and does
1021 * nothing.
1022 *
1023 * But what if another path (eg downconvert thread) has just started a
1024 * new locking action? The other path has re-set PENDING. Our path
1025 * cannot clear PENDING, because that will re-open the original race
1026 * window.
1027 *
1028 * [Example]
1029 *
1030 * ocfs2_meta_lock()
1031 * ocfs2_cluster_lock()
1032 * set BUSY
1033 * set PENDING
1034 * drop l_lock
1035 * ocfs2_dlm_lock()
1036 * ocfs2_locking_ast() ocfs2_downconvert_thread()
1037 * clear PENDING ocfs2_unblock_lock()
1038 * take_l_lock
1039 * !BUSY
1040 * ocfs2_prepare_downconvert()
1041 * set BUSY
1042 * set PENDING
1043 * drop l_lock
1044 * take l_lock
1045 * clear PENDING
1046 * drop l_lock
1047 * <window>
1048 * ocfs2_dlm_lock()
1049 *
1050 * So as you can see, we now have a window where l_lock is not held,
1051 * PENDING is not set, and ocfs2_dlm_lock() has not been called.
1052 *
1053 * The core problem is that ocfs2_cluster_lock() has cleared the PENDING
1054 * set by ocfs2_prepare_downconvert(). That wasn't nice.
1055 *
1056 * To solve this we introduce l_pending_gen. A call to
1057 * lockres_clear_pending() will only do so when it is passed a generation
1058 * number that matches the lockres. lockres_set_pending() will return the
1059 * current generation number. When ocfs2_cluster_lock() goes to clear
1060 * PENDING, it passes the generation it got from set_pending(). In our
1061 * example above, the generation numbers will *not* match. Thus,
1062 * ocfs2_cluster_lock() will not clear the PENDING set by
1063 * ocfs2_prepare_downconvert().
1064 */
1065
1066/* Unlocked version for ocfs2_locking_ast() */
1067static void __lockres_clear_pending(struct ocfs2_lock_res *lockres,
1068 unsigned int generation,
1069 struct ocfs2_super *osb)
1070{
1071 assert_spin_locked(&lockres->l_lock);
1072
1073 /*
1074 * The ast and locking functions can race us here. The winner
1075 * will clear pending, the loser will not.
1076 */
1077 if (!(lockres->l_flags & OCFS2_LOCK_PENDING) ||
1078 (lockres->l_pending_gen != generation))
1079 return;
1080
1081 lockres_clear_flags(lockres, OCFS2_LOCK_PENDING);
1082 lockres->l_pending_gen++;
1083
1084 /*
1085 * The downconvert thread may have skipped us because we
1086 * were PENDING. Wake it up.
1087 */
1088 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1089 ocfs2_wake_downconvert_thread(osb);
1090}
1091
1092/* Locked version for callers of ocfs2_dlm_lock() */
1093static void lockres_clear_pending(struct ocfs2_lock_res *lockres,
1094 unsigned int generation,
1095 struct ocfs2_super *osb)
1096{
1097 unsigned long flags;
1098
1099 spin_lock_irqsave(&lockres->l_lock, flags);
1100 __lockres_clear_pending(lockres, generation, osb);
1101 spin_unlock_irqrestore(&lockres->l_lock, flags);
1102}
1103
1104static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
1105{
1106 assert_spin_locked(&lockres->l_lock);
1107 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
1108
1109 lockres_or_flags(lockres, OCFS2_LOCK_PENDING);
1110
1111 return lockres->l_pending_gen;
1112}
1113
1114static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
1115{
1116 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1117 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1118 int needs_downconvert;
1119 unsigned long flags;
1120
1121 BUG_ON(level <= DLM_LOCK_NL);
1122
1123 mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
1124 "type %s\n", lockres->l_name, level, lockres->l_level,
1125 ocfs2_lock_type_string(lockres->l_type));
1126
1127 /*
1128 * We can skip the bast for locks which don't enable caching -
1129 * they'll be dropped at the earliest possible time anyway.
1130 */
1131 if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
1132 return;
1133
1134 spin_lock_irqsave(&lockres->l_lock, flags);
1135 needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
1136 if (needs_downconvert)
1137 ocfs2_schedule_blocked_lock(osb, lockres);
1138 spin_unlock_irqrestore(&lockres->l_lock, flags);
1139
1140 wake_up(&lockres->l_event);
1141
1142 ocfs2_wake_downconvert_thread(osb);
1143}
1144
1145static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
1146{
1147 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1148 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1149 unsigned long flags;
1150 int status;
1151
1152 spin_lock_irqsave(&lockres->l_lock, flags);
1153
1154 status = ocfs2_dlm_lock_status(&lockres->l_lksb);
1155
1156 if (status == -EAGAIN) {
1157 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1158 goto out;
1159 }
1160
1161 if (status) {
1162 mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n",
1163 lockres->l_name, status);
1164 spin_unlock_irqrestore(&lockres->l_lock, flags);
1165 return;
1166 }
1167
1168 mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
1169 "level %d => %d\n", lockres->l_name, lockres->l_action,
1170 lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
1171
1172 switch(lockres->l_action) {
1173 case OCFS2_AST_ATTACH:
1174 ocfs2_generic_handle_attach_action(lockres);
1175 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
1176 break;
1177 case OCFS2_AST_CONVERT:
1178 ocfs2_generic_handle_convert_action(lockres);
1179 break;
1180 case OCFS2_AST_DOWNCONVERT:
1181 ocfs2_generic_handle_downconvert_action(lockres);
1182 break;
1183 default:
1184 mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
1185 "flags 0x%lx, unlock: %u\n",
1186 lockres->l_name, lockres->l_action, lockres->l_flags,
1187 lockres->l_unlock_action);
1188 BUG();
1189 }
1190out:
1191 /* set it to something invalid so if we get called again we
1192 * can catch it. */
1193 lockres->l_action = OCFS2_AST_INVALID;
1194
1195 /* Did we try to cancel this lock? Clear that state */
1196 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT)
1197 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1198
1199 /*
1200 * We may have beaten the locking functions here. We certainly
1201 * know that dlm_lock() has been called :-)
1202 * Because we can't have two lock calls in flight at once, we
1203 * can use lockres->l_pending_gen.
1204 */
1205 __lockres_clear_pending(lockres, lockres->l_pending_gen, osb);
1206
1207 wake_up(&lockres->l_event);
1208 spin_unlock_irqrestore(&lockres->l_lock, flags);
1209}
1210
1211static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
1212{
1213 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1214 unsigned long flags;
1215
1216 mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
1217 lockres->l_name, lockres->l_unlock_action);
1218
1219 spin_lock_irqsave(&lockres->l_lock, flags);
1220 if (error) {
1221 mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
1222 "unlock_action %d\n", error, lockres->l_name,
1223 lockres->l_unlock_action);
1224 spin_unlock_irqrestore(&lockres->l_lock, flags);
1225 return;
1226 }
1227
1228 switch(lockres->l_unlock_action) {
1229 case OCFS2_UNLOCK_CANCEL_CONVERT:
1230 mlog(0, "Cancel convert success for %s\n", lockres->l_name);
1231 lockres->l_action = OCFS2_AST_INVALID;
1232 /* Downconvert thread may have requeued this lock, we
1233 * need to wake it. */
1234 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1235 ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
1236 break;
1237 case OCFS2_UNLOCK_DROP_LOCK:
1238 lockres->l_level = DLM_LOCK_IV;
1239 break;
1240 default:
1241 BUG();
1242 }
1243
1244 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1245 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1246 wake_up(&lockres->l_event);
1247 spin_unlock_irqrestore(&lockres->l_lock, flags);
1248}
1249
1250/*
1251 * This is the filesystem locking protocol. It provides the lock handling
1252 * hooks for the underlying DLM. It has a maximum version number.
1253 * The version number allows interoperability with systems running at
1254 * the same major number and an equal or smaller minor number.
1255 *
1256 * Whenever the filesystem does new things with locks (adds or removes a
1257 * lock, orders them differently, does different things underneath a lock),
1258 * the version must be changed. The protocol is negotiated when joining
1259 * the dlm domain. A node may join the domain if its major version is
1260 * identical to all other nodes and its minor version is greater than
1261 * or equal to all other nodes. When its minor version is greater than
1262 * the other nodes, it will run at the minor version specified by the
1263 * other nodes.
1264 *
1265 * If a locking change is made that will not be compatible with older
1266 * versions, the major number must be increased and the minor version set
1267 * to zero. If a change merely adds a behavior that can be disabled when
1268 * speaking to older versions, the minor version must be increased. If a
1269 * change adds a fully backwards compatible change (eg, LVB changes that
1270 * are just ignored by older versions), the version does not need to be
1271 * updated.
1272 */
1273static struct ocfs2_locking_protocol lproto = {
1274 .lp_max_version = {
1275 .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
1276 .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
1277 },
1278 .lp_lock_ast = ocfs2_locking_ast,
1279 .lp_blocking_ast = ocfs2_blocking_ast,
1280 .lp_unlock_ast = ocfs2_unlock_ast,
1281};
1282
1283void ocfs2_set_locking_protocol(void)
1284{
1285 ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
1286}
1287
1288static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
1289 int convert)
1290{
1291 unsigned long flags;
1292
1293 spin_lock_irqsave(&lockres->l_lock, flags);
1294 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1295 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1296 if (convert)
1297 lockres->l_action = OCFS2_AST_INVALID;
1298 else
1299 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1300 spin_unlock_irqrestore(&lockres->l_lock, flags);
1301
1302 wake_up(&lockres->l_event);
1303}
1304
1305/* Note: If we detect another process working on the lock (i.e.,
1306 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
1307 * to do the right thing in that case.
1308 */
1309static int ocfs2_lock_create(struct ocfs2_super *osb,
1310 struct ocfs2_lock_res *lockres,
1311 int level,
1312 u32 dlm_flags)
1313{
1314 int ret = 0;
1315 unsigned long flags;
1316 unsigned int gen;
1317
1318 mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level,
1319 dlm_flags);
1320
1321 spin_lock_irqsave(&lockres->l_lock, flags);
1322 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
1323 (lockres->l_flags & OCFS2_LOCK_BUSY)) {
1324 spin_unlock_irqrestore(&lockres->l_lock, flags);
1325 goto bail;
1326 }
1327
1328 lockres->l_action = OCFS2_AST_ATTACH;
1329 lockres->l_requested = level;
1330 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1331 gen = lockres_set_pending(lockres);
1332 spin_unlock_irqrestore(&lockres->l_lock, flags);
1333
1334 ret = ocfs2_dlm_lock(osb->cconn,
1335 level,
1336 &lockres->l_lksb,
1337 dlm_flags,
1338 lockres->l_name,
1339 OCFS2_LOCK_ID_MAX_LEN - 1);
1340 lockres_clear_pending(lockres, gen, osb);
1341 if (ret) {
1342 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
1343 ocfs2_recover_from_dlm_error(lockres, 1);
1344 }
1345
1346 mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name);
1347
1348bail:
1349 return ret;
1350}
1351
1352static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
1353 int flag)
1354{
1355 unsigned long flags;
1356 int ret;
1357
1358 spin_lock_irqsave(&lockres->l_lock, flags);
1359 ret = lockres->l_flags & flag;
1360 spin_unlock_irqrestore(&lockres->l_lock, flags);
1361
1362 return ret;
1363}
1364
1365static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
1366
1367{
1368 wait_event(lockres->l_event,
1369 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
1370}
1371
1372static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
1373
1374{
1375 wait_event(lockres->l_event,
1376 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
1377}
1378
1379/* predict what lock level we'll be dropping down to on behalf
1380 * of another node, and return true if the currently wanted
1381 * level will be compatible with it. */
1382static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
1383 int wanted)
1384{
1385 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
1386
1387 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
1388}
1389
1390static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
1391{
1392 INIT_LIST_HEAD(&mw->mw_item);
1393 init_completion(&mw->mw_complete);
1394 ocfs2_init_start_time(mw);
1395}
1396
1397static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
1398{
1399 wait_for_completion(&mw->mw_complete);
1400 /* Re-arm the completion in case we want to wait on it again */
1401 reinit_completion(&mw->mw_complete);
1402 return mw->mw_status;
1403}
1404
1405static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
1406 struct ocfs2_mask_waiter *mw,
1407 unsigned long mask,
1408 unsigned long goal)
1409{
1410 BUG_ON(!list_empty(&mw->mw_item));
1411
1412 assert_spin_locked(&lockres->l_lock);
1413
1414 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
1415 mw->mw_mask = mask;
1416 mw->mw_goal = goal;
1417 ocfs2_track_lock_wait(lockres);
1418}
1419
1420/* returns 0 if the mw that was removed was already satisfied, -EBUSY
1421 * if the mask still hadn't reached its goal */
1422static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1423 struct ocfs2_mask_waiter *mw)
1424{
1425 int ret = 0;
1426
1427 assert_spin_locked(&lockres->l_lock);
1428 if (!list_empty(&mw->mw_item)) {
1429 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
1430 ret = -EBUSY;
1431
1432 list_del_init(&mw->mw_item);
1433 init_completion(&mw->mw_complete);
1434 ocfs2_track_lock_wait(lockres);
1435 }
1436
1437 return ret;
1438}
1439
1440static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1441 struct ocfs2_mask_waiter *mw)
1442{
1443 unsigned long flags;
1444 int ret = 0;
1445
1446 spin_lock_irqsave(&lockres->l_lock, flags);
1447 ret = __lockres_remove_mask_waiter(lockres, mw);
1448 spin_unlock_irqrestore(&lockres->l_lock, flags);
1449
1450 return ret;
1451
1452}
1453
1454static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
1455 struct ocfs2_lock_res *lockres)
1456{
1457 int ret;
1458
1459 ret = wait_for_completion_interruptible(&mw->mw_complete);
1460 if (ret)
1461 lockres_remove_mask_waiter(lockres, mw);
1462 else
1463 ret = mw->mw_status;
1464 /* Re-arm the completion in case we want to wait on it again */
1465 reinit_completion(&mw->mw_complete);
1466 return ret;
1467}
1468
1469static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
1470 struct ocfs2_lock_res *lockres,
1471 int level,
1472 u32 lkm_flags,
1473 int arg_flags,
1474 int l_subclass,
1475 unsigned long caller_ip)
1476{
1477 struct ocfs2_mask_waiter mw;
1478 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
1479 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
1480 unsigned long flags;
1481 unsigned int gen;
1482 int noqueue_attempted = 0;
1483 int dlm_locked = 0;
1484 int kick_dc = 0;
1485
1486 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
1487 mlog_errno(-EINVAL);
1488 return -EINVAL;
1489 }
1490
1491 ocfs2_init_mask_waiter(&mw);
1492
1493 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
1494 lkm_flags |= DLM_LKF_VALBLK;
1495
1496again:
1497 wait = 0;
1498
1499 spin_lock_irqsave(&lockres->l_lock, flags);
1500
1501 if (catch_signals && signal_pending(current)) {
1502 ret = -ERESTARTSYS;
1503 goto unlock;
1504 }
1505
1506 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
1507 "Cluster lock called on freeing lockres %s! flags "
1508 "0x%lx\n", lockres->l_name, lockres->l_flags);
1509
1510 /* We only compare against the currently granted level
1511 * here. If the lock is blocked waiting on a downconvert,
1512 * we'll get caught below. */
1513 if (lockres->l_flags & OCFS2_LOCK_BUSY &&
1514 level > lockres->l_level) {
1515 /* is someone sitting in dlm_lock? If so, wait on
1516 * them. */
1517 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1518 wait = 1;
1519 goto unlock;
1520 }
1521
1522 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) {
1523 /*
1524 * We've upconverted. If the lock now has a level we can
1525 * work with, we take it. If, however, the lock is not at the
1526 * required level, we go thru the full cycle. One way this could
1527 * happen is if a process requesting an upconvert to PR is
1528 * closely followed by another requesting upconvert to an EX.
1529 * If the process requesting EX lands here, we want it to
1530 * continue attempting to upconvert and let the process
1531 * requesting PR take the lock.
1532 * If multiple processes request upconvert to PR, the first one
1533 * here will take the lock. The others will have to go thru the
1534 * OCFS2_LOCK_BLOCKED check to ensure that there is no pending
1535 * downconvert request.
1536 */
1537 if (level <= lockres->l_level)
1538 goto update_holders;
1539 }
1540
1541 if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
1542 !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
1543 /* is the lock is currently blocked on behalf of
1544 * another node */
1545 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
1546 wait = 1;
1547 goto unlock;
1548 }
1549
1550 if (level > lockres->l_level) {
1551 if (noqueue_attempted > 0) {
1552 ret = -EAGAIN;
1553 goto unlock;
1554 }
1555 if (lkm_flags & DLM_LKF_NOQUEUE)
1556 noqueue_attempted = 1;
1557
1558 if (lockres->l_action != OCFS2_AST_INVALID)
1559 mlog(ML_ERROR, "lockres %s has action %u pending\n",
1560 lockres->l_name, lockres->l_action);
1561
1562 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1563 lockres->l_action = OCFS2_AST_ATTACH;
1564 lkm_flags &= ~DLM_LKF_CONVERT;
1565 } else {
1566 lockres->l_action = OCFS2_AST_CONVERT;
1567 lkm_flags |= DLM_LKF_CONVERT;
1568 }
1569
1570 lockres->l_requested = level;
1571 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1572 gen = lockres_set_pending(lockres);
1573 spin_unlock_irqrestore(&lockres->l_lock, flags);
1574
1575 BUG_ON(level == DLM_LOCK_IV);
1576 BUG_ON(level == DLM_LOCK_NL);
1577
1578 mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
1579 lockres->l_name, lockres->l_level, level);
1580
1581 /* call dlm_lock to upgrade lock now */
1582 ret = ocfs2_dlm_lock(osb->cconn,
1583 level,
1584 &lockres->l_lksb,
1585 lkm_flags,
1586 lockres->l_name,
1587 OCFS2_LOCK_ID_MAX_LEN - 1);
1588 lockres_clear_pending(lockres, gen, osb);
1589 if (ret) {
1590 if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
1591 (ret != -EAGAIN)) {
1592 ocfs2_log_dlm_error("ocfs2_dlm_lock",
1593 ret, lockres);
1594 }
1595 ocfs2_recover_from_dlm_error(lockres, 1);
1596 goto out;
1597 }
1598 dlm_locked = 1;
1599
1600 mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n",
1601 lockres->l_name);
1602
1603 /* At this point we've gone inside the dlm and need to
1604 * complete our work regardless. */
1605 catch_signals = 0;
1606
1607 /* wait for busy to clear and carry on */
1608 goto again;
1609 }
1610
1611update_holders:
1612 /* Ok, if we get here then we're good to go. */
1613 ocfs2_inc_holders(lockres, level);
1614
1615 ret = 0;
1616unlock:
1617 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1618
1619 /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */
1620 kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED);
1621
1622 spin_unlock_irqrestore(&lockres->l_lock, flags);
1623 if (kick_dc)
1624 ocfs2_wake_downconvert_thread(osb);
1625out:
1626 /*
1627 * This is helping work around a lock inversion between the page lock
1628 * and dlm locks. One path holds the page lock while calling aops
1629 * which block acquiring dlm locks. The voting thread holds dlm
1630 * locks while acquiring page locks while down converting data locks.
1631 * This block is helping an aop path notice the inversion and back
1632 * off to unlock its page lock before trying the dlm lock again.
1633 */
1634 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
1635 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
1636 wait = 0;
1637 spin_lock_irqsave(&lockres->l_lock, flags);
1638 if (__lockres_remove_mask_waiter(lockres, &mw)) {
1639 if (dlm_locked)
1640 lockres_or_flags(lockres,
1641 OCFS2_LOCK_NONBLOCK_FINISHED);
1642 spin_unlock_irqrestore(&lockres->l_lock, flags);
1643 ret = -EAGAIN;
1644 } else {
1645 spin_unlock_irqrestore(&lockres->l_lock, flags);
1646 goto again;
1647 }
1648 }
1649 if (wait) {
1650 ret = ocfs2_wait_for_mask(&mw);
1651 if (ret == 0)
1652 goto again;
1653 mlog_errno(ret);
1654 }
1655 ocfs2_update_lock_stats(lockres, level, &mw, ret);
1656
1657#ifdef CONFIG_DEBUG_LOCK_ALLOC
1658 if (!ret && lockres->l_lockdep_map.key != NULL) {
1659 if (level == DLM_LOCK_PR)
1660 rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass,
1661 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1662 caller_ip);
1663 else
1664 rwsem_acquire(&lockres->l_lockdep_map, l_subclass,
1665 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1666 caller_ip);
1667 }
1668#endif
1669 return ret;
1670}
1671
1672static inline int ocfs2_cluster_lock(struct ocfs2_super *osb,
1673 struct ocfs2_lock_res *lockres,
1674 int level,
1675 u32 lkm_flags,
1676 int arg_flags)
1677{
1678 return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags,
1679 0, _RET_IP_);
1680}
1681
1682
1683static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
1684 struct ocfs2_lock_res *lockres,
1685 int level,
1686 unsigned long caller_ip)
1687{
1688 unsigned long flags;
1689
1690 spin_lock_irqsave(&lockres->l_lock, flags);
1691 ocfs2_dec_holders(lockres, level);
1692 ocfs2_downconvert_on_unlock(osb, lockres);
1693 spin_unlock_irqrestore(&lockres->l_lock, flags);
1694#ifdef CONFIG_DEBUG_LOCK_ALLOC
1695 if (lockres->l_lockdep_map.key != NULL)
1696 rwsem_release(&lockres->l_lockdep_map, caller_ip);
1697#endif
1698}
1699
1700static int ocfs2_create_new_lock(struct ocfs2_super *osb,
1701 struct ocfs2_lock_res *lockres,
1702 int ex,
1703 int local)
1704{
1705 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1706 unsigned long flags;
1707 u32 lkm_flags = local ? DLM_LKF_LOCAL : 0;
1708
1709 spin_lock_irqsave(&lockres->l_lock, flags);
1710 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
1711 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
1712 spin_unlock_irqrestore(&lockres->l_lock, flags);
1713
1714 return ocfs2_lock_create(osb, lockres, level, lkm_flags);
1715}
1716
1717/* Grants us an EX lock on the data and metadata resources, skipping
1718 * the normal cluster directory lookup. Use this ONLY on newly created
1719 * inodes which other nodes can't possibly see, and which haven't been
1720 * hashed in the inode hash yet. This can give us a good performance
1721 * increase as it'll skip the network broadcast normally associated
1722 * with creating a new lock resource. */
1723int ocfs2_create_new_inode_locks(struct inode *inode)
1724{
1725 int ret;
1726 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1727
1728 BUG_ON(!ocfs2_inode_is_new(inode));
1729
1730 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
1731
1732 /* NOTE: That we don't increment any of the holder counts, nor
1733 * do we add anything to a journal handle. Since this is
1734 * supposed to be a new inode which the cluster doesn't know
1735 * about yet, there is no need to. As far as the LVB handling
1736 * is concerned, this is basically like acquiring an EX lock
1737 * on a resource which has an invalid one -- we'll set it
1738 * valid when we release the EX. */
1739
1740 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
1741 if (ret) {
1742 mlog_errno(ret);
1743 goto bail;
1744 }
1745
1746 /*
1747 * We don't want to use DLM_LKF_LOCAL on a meta data lock as they
1748 * don't use a generation in their lock names.
1749 */
1750 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
1751 if (ret) {
1752 mlog_errno(ret);
1753 goto bail;
1754 }
1755
1756 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
1757 if (ret)
1758 mlog_errno(ret);
1759
1760bail:
1761 return ret;
1762}
1763
1764int ocfs2_rw_lock(struct inode *inode, int write)
1765{
1766 int status, level;
1767 struct ocfs2_lock_res *lockres;
1768 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1769
1770 mlog(0, "inode %llu take %s RW lock\n",
1771 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1772 write ? "EXMODE" : "PRMODE");
1773
1774 if (ocfs2_mount_local(osb))
1775 return 0;
1776
1777 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1778
1779 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1780
1781 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
1782 if (status < 0)
1783 mlog_errno(status);
1784
1785 return status;
1786}
1787
1788int ocfs2_try_rw_lock(struct inode *inode, int write)
1789{
1790 int status, level;
1791 struct ocfs2_lock_res *lockres;
1792 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1793
1794 mlog(0, "inode %llu try to take %s RW lock\n",
1795 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1796 write ? "EXMODE" : "PRMODE");
1797
1798 if (ocfs2_mount_local(osb))
1799 return 0;
1800
1801 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1802
1803 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1804
1805 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0);
1806 return status;
1807}
1808
1809void ocfs2_rw_unlock(struct inode *inode, int write)
1810{
1811 int level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1812 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
1813 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1814
1815 mlog(0, "inode %llu drop %s RW lock\n",
1816 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1817 write ? "EXMODE" : "PRMODE");
1818
1819 if (!ocfs2_mount_local(osb))
1820 ocfs2_cluster_unlock(osb, lockres, level);
1821}
1822
1823/*
1824 * ocfs2_open_lock always get PR mode lock.
1825 */
1826int ocfs2_open_lock(struct inode *inode)
1827{
1828 int status = 0;
1829 struct ocfs2_lock_res *lockres;
1830 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1831
1832 mlog(0, "inode %llu take PRMODE open lock\n",
1833 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1834
1835 if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb))
1836 goto out;
1837
1838 lockres = &OCFS2_I(inode)->ip_open_lockres;
1839
1840 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_PR, 0, 0);
1841 if (status < 0)
1842 mlog_errno(status);
1843
1844out:
1845 return status;
1846}
1847
1848int ocfs2_try_open_lock(struct inode *inode, int write)
1849{
1850 int status = 0, level;
1851 struct ocfs2_lock_res *lockres;
1852 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1853
1854 mlog(0, "inode %llu try to take %s open lock\n",
1855 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1856 write ? "EXMODE" : "PRMODE");
1857
1858 if (ocfs2_is_hard_readonly(osb)) {
1859 if (write)
1860 status = -EROFS;
1861 goto out;
1862 }
1863
1864 if (ocfs2_mount_local(osb))
1865 goto out;
1866
1867 lockres = &OCFS2_I(inode)->ip_open_lockres;
1868
1869 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1870
1871 /*
1872 * The file system may already holding a PRMODE/EXMODE open lock.
1873 * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on
1874 * other nodes and the -EAGAIN will indicate to the caller that
1875 * this inode is still in use.
1876 */
1877 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0);
1878
1879out:
1880 return status;
1881}
1882
1883/*
1884 * ocfs2_open_unlock unlock PR and EX mode open locks.
1885 */
1886void ocfs2_open_unlock(struct inode *inode)
1887{
1888 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
1889 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1890
1891 mlog(0, "inode %llu drop open lock\n",
1892 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1893
1894 if (ocfs2_mount_local(osb))
1895 goto out;
1896
1897 if(lockres->l_ro_holders)
1898 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_PR);
1899 if(lockres->l_ex_holders)
1900 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
1901
1902out:
1903 return;
1904}
1905
1906static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
1907 int level)
1908{
1909 int ret;
1910 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1911 unsigned long flags;
1912 struct ocfs2_mask_waiter mw;
1913
1914 ocfs2_init_mask_waiter(&mw);
1915
1916retry_cancel:
1917 spin_lock_irqsave(&lockres->l_lock, flags);
1918 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
1919 ret = ocfs2_prepare_cancel_convert(osb, lockres);
1920 if (ret) {
1921 spin_unlock_irqrestore(&lockres->l_lock, flags);
1922 ret = ocfs2_cancel_convert(osb, lockres);
1923 if (ret < 0) {
1924 mlog_errno(ret);
1925 goto out;
1926 }
1927 goto retry_cancel;
1928 }
1929 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1930 spin_unlock_irqrestore(&lockres->l_lock, flags);
1931
1932 ocfs2_wait_for_mask(&mw);
1933 goto retry_cancel;
1934 }
1935
1936 ret = -ERESTARTSYS;
1937 /*
1938 * We may still have gotten the lock, in which case there's no
1939 * point to restarting the syscall.
1940 */
1941 if (lockres->l_level == level)
1942 ret = 0;
1943
1944 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
1945 lockres->l_flags, lockres->l_level, lockres->l_action);
1946
1947 spin_unlock_irqrestore(&lockres->l_lock, flags);
1948
1949out:
1950 return ret;
1951}
1952
1953/*
1954 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
1955 * flock() calls. The locking approach this requires is sufficiently
1956 * different from all other cluster lock types that we implement a
1957 * separate path to the "low-level" dlm calls. In particular:
1958 *
1959 * - No optimization of lock levels is done - we take at exactly
1960 * what's been requested.
1961 *
1962 * - No lock caching is employed. We immediately downconvert to
1963 * no-lock at unlock time. This also means flock locks never go on
1964 * the blocking list).
1965 *
1966 * - Since userspace can trivially deadlock itself with flock, we make
1967 * sure to allow cancellation of a misbehaving applications flock()
1968 * request.
1969 *
1970 * - Access to any flock lockres doesn't require concurrency, so we
1971 * can simplify the code by requiring the caller to guarantee
1972 * serialization of dlmglue flock calls.
1973 */
1974int ocfs2_file_lock(struct file *file, int ex, int trylock)
1975{
1976 int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1977 unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
1978 unsigned long flags;
1979 struct ocfs2_file_private *fp = file->private_data;
1980 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1981 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1982 struct ocfs2_mask_waiter mw;
1983
1984 ocfs2_init_mask_waiter(&mw);
1985
1986 if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
1987 (lockres->l_level > DLM_LOCK_NL)) {
1988 mlog(ML_ERROR,
1989 "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
1990 "level: %u\n", lockres->l_name, lockres->l_flags,
1991 lockres->l_level);
1992 return -EINVAL;
1993 }
1994
1995 spin_lock_irqsave(&lockres->l_lock, flags);
1996 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1997 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1998 spin_unlock_irqrestore(&lockres->l_lock, flags);
1999
2000 /*
2001 * Get the lock at NLMODE to start - that way we
2002 * can cancel the upconvert request if need be.
2003 */
2004 ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
2005 if (ret < 0) {
2006 mlog_errno(ret);
2007 goto out;
2008 }
2009
2010 ret = ocfs2_wait_for_mask(&mw);
2011 if (ret) {
2012 mlog_errno(ret);
2013 goto out;
2014 }
2015 spin_lock_irqsave(&lockres->l_lock, flags);
2016 }
2017
2018 lockres->l_action = OCFS2_AST_CONVERT;
2019 lkm_flags |= DLM_LKF_CONVERT;
2020 lockres->l_requested = level;
2021 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2022
2023 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
2024 spin_unlock_irqrestore(&lockres->l_lock, flags);
2025
2026 ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags,
2027 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1);
2028 if (ret) {
2029 if (!trylock || (ret != -EAGAIN)) {
2030 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
2031 ret = -EINVAL;
2032 }
2033
2034 ocfs2_recover_from_dlm_error(lockres, 1);
2035 lockres_remove_mask_waiter(lockres, &mw);
2036 goto out;
2037 }
2038
2039 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
2040 if (ret == -ERESTARTSYS) {
2041 /*
2042 * Userspace can cause deadlock itself with
2043 * flock(). Current behavior locally is to allow the
2044 * deadlock, but abort the system call if a signal is
2045 * received. We follow this example, otherwise a
2046 * poorly written program could sit in kernel until
2047 * reboot.
2048 *
2049 * Handling this is a bit more complicated for Ocfs2
2050 * though. We can't exit this function with an
2051 * outstanding lock request, so a cancel convert is
2052 * required. We intentionally overwrite 'ret' - if the
2053 * cancel fails and the lock was granted, it's easier
2054 * to just bubble success back up to the user.
2055 */
2056 ret = ocfs2_flock_handle_signal(lockres, level);
2057 } else if (!ret && (level > lockres->l_level)) {
2058 /* Trylock failed asynchronously */
2059 BUG_ON(!trylock);
2060 ret = -EAGAIN;
2061 }
2062
2063out:
2064
2065 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
2066 lockres->l_name, ex, trylock, ret);
2067 return ret;
2068}
2069
2070void ocfs2_file_unlock(struct file *file)
2071{
2072 int ret;
2073 unsigned int gen;
2074 unsigned long flags;
2075 struct ocfs2_file_private *fp = file->private_data;
2076 struct ocfs2_lock_res *lockres = &fp->fp_flock;
2077 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
2078 struct ocfs2_mask_waiter mw;
2079
2080 ocfs2_init_mask_waiter(&mw);
2081
2082 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
2083 return;
2084
2085 if (lockres->l_level == DLM_LOCK_NL)
2086 return;
2087
2088 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
2089 lockres->l_name, lockres->l_flags, lockres->l_level,
2090 lockres->l_action);
2091
2092 spin_lock_irqsave(&lockres->l_lock, flags);
2093 /*
2094 * Fake a blocking ast for the downconvert code.
2095 */
2096 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
2097 lockres->l_blocking = DLM_LOCK_EX;
2098
2099 gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
2100 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
2101 spin_unlock_irqrestore(&lockres->l_lock, flags);
2102
2103 ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
2104 if (ret) {
2105 mlog_errno(ret);
2106 return;
2107 }
2108
2109 ret = ocfs2_wait_for_mask(&mw);
2110 if (ret)
2111 mlog_errno(ret);
2112}
2113
2114static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
2115 struct ocfs2_lock_res *lockres)
2116{
2117 int kick = 0;
2118
2119 /* If we know that another node is waiting on our lock, kick
2120 * the downconvert thread * pre-emptively when we reach a release
2121 * condition. */
2122 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
2123 switch(lockres->l_blocking) {
2124 case DLM_LOCK_EX:
2125 if (!lockres->l_ex_holders && !lockres->l_ro_holders)
2126 kick = 1;
2127 break;
2128 case DLM_LOCK_PR:
2129 if (!lockres->l_ex_holders)
2130 kick = 1;
2131 break;
2132 default:
2133 BUG();
2134 }
2135 }
2136
2137 if (kick)
2138 ocfs2_wake_downconvert_thread(osb);
2139}
2140
2141#define OCFS2_SEC_BITS 34
2142#define OCFS2_SEC_SHIFT (64 - OCFS2_SEC_BITS)
2143#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
2144
2145/* LVB only has room for 64 bits of time here so we pack it for
2146 * now. */
2147static u64 ocfs2_pack_timespec(struct timespec64 *spec)
2148{
2149 u64 res;
2150 u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull);
2151 u32 nsec = spec->tv_nsec;
2152
2153 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
2154
2155 return res;
2156}
2157
2158/* Call this with the lockres locked. I am reasonably sure we don't
2159 * need ip_lock in this function as anyone who would be changing those
2160 * values is supposed to be blocked in ocfs2_inode_lock right now. */
2161static void __ocfs2_stuff_meta_lvb(struct inode *inode)
2162{
2163 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2164 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2165 struct ocfs2_meta_lvb *lvb;
2166
2167 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2168
2169 /*
2170 * Invalidate the LVB of a deleted inode - this way other
2171 * nodes are forced to go to disk and discover the new inode
2172 * status.
2173 */
2174 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2175 lvb->lvb_version = 0;
2176 goto out;
2177 }
2178
2179 lvb->lvb_version = OCFS2_LVB_VERSION;
2180 lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
2181 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
2182 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode));
2183 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
2184 lvb->lvb_imode = cpu_to_be16(inode->i_mode);
2185 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
2186 lvb->lvb_iatime_packed =
2187 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
2188 lvb->lvb_ictime_packed =
2189 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
2190 lvb->lvb_imtime_packed =
2191 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
2192 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
2193 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
2194 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
2195
2196out:
2197 mlog_meta_lvb(0, lockres);
2198}
2199
2200static void ocfs2_unpack_timespec(struct timespec64 *spec,
2201 u64 packed_time)
2202{
2203 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
2204 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
2205}
2206
2207static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
2208{
2209 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2210 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2211 struct ocfs2_meta_lvb *lvb;
2212
2213 mlog_meta_lvb(0, lockres);
2214
2215 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2216
2217 /* We're safe here without the lockres lock... */
2218 spin_lock(&oi->ip_lock);
2219 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
2220 i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
2221
2222 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
2223 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
2224 ocfs2_set_inode_flags(inode);
2225
2226 /* fast-symlinks are a special case */
2227 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
2228 inode->i_blocks = 0;
2229 else
2230 inode->i_blocks = ocfs2_inode_sector_count(inode);
2231
2232 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid));
2233 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
2234 inode->i_mode = be16_to_cpu(lvb->lvb_imode);
2235 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
2236 ocfs2_unpack_timespec(&inode->i_atime,
2237 be64_to_cpu(lvb->lvb_iatime_packed));
2238 ocfs2_unpack_timespec(&inode->i_mtime,
2239 be64_to_cpu(lvb->lvb_imtime_packed));
2240 ocfs2_unpack_timespec(&inode->i_ctime,
2241 be64_to_cpu(lvb->lvb_ictime_packed));
2242 spin_unlock(&oi->ip_lock);
2243}
2244
2245static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
2246 struct ocfs2_lock_res *lockres)
2247{
2248 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2249
2250 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
2251 && lvb->lvb_version == OCFS2_LVB_VERSION
2252 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
2253 return 1;
2254 return 0;
2255}
2256
2257/* Determine whether a lock resource needs to be refreshed, and
2258 * arbitrate who gets to refresh it.
2259 *
2260 * 0 means no refresh needed.
2261 *
2262 * > 0 means you need to refresh this and you MUST call
2263 * ocfs2_complete_lock_res_refresh afterwards. */
2264static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
2265{
2266 unsigned long flags;
2267 int status = 0;
2268
2269refresh_check:
2270 spin_lock_irqsave(&lockres->l_lock, flags);
2271 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
2272 spin_unlock_irqrestore(&lockres->l_lock, flags);
2273 goto bail;
2274 }
2275
2276 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
2277 spin_unlock_irqrestore(&lockres->l_lock, flags);
2278
2279 ocfs2_wait_on_refreshing_lock(lockres);
2280 goto refresh_check;
2281 }
2282
2283 /* Ok, I'll be the one to refresh this lock. */
2284 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
2285 spin_unlock_irqrestore(&lockres->l_lock, flags);
2286
2287 status = 1;
2288bail:
2289 mlog(0, "status %d\n", status);
2290 return status;
2291}
2292
2293/* If status is non zero, I'll mark it as not being in refresh
2294 * anymroe, but i won't clear the needs refresh flag. */
2295static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
2296 int status)
2297{
2298 unsigned long flags;
2299
2300 spin_lock_irqsave(&lockres->l_lock, flags);
2301 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
2302 if (!status)
2303 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
2304 spin_unlock_irqrestore(&lockres->l_lock, flags);
2305
2306 wake_up(&lockres->l_event);
2307}
2308
2309/* may or may not return a bh if it went to disk. */
2310static int ocfs2_inode_lock_update(struct inode *inode,
2311 struct buffer_head **bh)
2312{
2313 int status = 0;
2314 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2315 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2316 struct ocfs2_dinode *fe;
2317 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2318
2319 if (ocfs2_mount_local(osb))
2320 goto bail;
2321
2322 spin_lock(&oi->ip_lock);
2323 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2324 mlog(0, "Orphaned inode %llu was deleted while we "
2325 "were waiting on a lock. ip_flags = 0x%x\n",
2326 (unsigned long long)oi->ip_blkno, oi->ip_flags);
2327 spin_unlock(&oi->ip_lock);
2328 status = -ENOENT;
2329 goto bail;
2330 }
2331 spin_unlock(&oi->ip_lock);
2332
2333 if (!ocfs2_should_refresh_lock_res(lockres))
2334 goto bail;
2335
2336 /* This will discard any caching information we might have had
2337 * for the inode metadata. */
2338 ocfs2_metadata_cache_purge(INODE_CACHE(inode));
2339
2340 ocfs2_extent_map_trunc(inode, 0);
2341
2342 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
2343 mlog(0, "Trusting LVB on inode %llu\n",
2344 (unsigned long long)oi->ip_blkno);
2345 ocfs2_refresh_inode_from_lvb(inode);
2346 } else {
2347 /* Boo, we have to go to disk. */
2348 /* read bh, cast, ocfs2_refresh_inode */
2349 status = ocfs2_read_inode_block(inode, bh);
2350 if (status < 0) {
2351 mlog_errno(status);
2352 goto bail_refresh;
2353 }
2354 fe = (struct ocfs2_dinode *) (*bh)->b_data;
2355
2356 /* This is a good chance to make sure we're not
2357 * locking an invalid object. ocfs2_read_inode_block()
2358 * already checked that the inode block is sane.
2359 *
2360 * We bug on a stale inode here because we checked
2361 * above whether it was wiped from disk. The wiping
2362 * node provides a guarantee that we receive that
2363 * message and can mark the inode before dropping any
2364 * locks associated with it. */
2365 mlog_bug_on_msg(inode->i_generation !=
2366 le32_to_cpu(fe->i_generation),
2367 "Invalid dinode %llu disk generation: %u "
2368 "inode->i_generation: %u\n",
2369 (unsigned long long)oi->ip_blkno,
2370 le32_to_cpu(fe->i_generation),
2371 inode->i_generation);
2372 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
2373 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
2374 "Stale dinode %llu dtime: %llu flags: 0x%x\n",
2375 (unsigned long long)oi->ip_blkno,
2376 (unsigned long long)le64_to_cpu(fe->i_dtime),
2377 le32_to_cpu(fe->i_flags));
2378
2379 ocfs2_refresh_inode(inode, fe);
2380 ocfs2_track_lock_refresh(lockres);
2381 }
2382
2383 status = 0;
2384bail_refresh:
2385 ocfs2_complete_lock_res_refresh(lockres, status);
2386bail:
2387 return status;
2388}
2389
2390static int ocfs2_assign_bh(struct inode *inode,
2391 struct buffer_head **ret_bh,
2392 struct buffer_head *passed_bh)
2393{
2394 int status;
2395
2396 if (passed_bh) {
2397 /* Ok, the update went to disk for us, use the
2398 * returned bh. */
2399 *ret_bh = passed_bh;
2400 get_bh(*ret_bh);
2401
2402 return 0;
2403 }
2404
2405 status = ocfs2_read_inode_block(inode, ret_bh);
2406 if (status < 0)
2407 mlog_errno(status);
2408
2409 return status;
2410}
2411
2412/*
2413 * returns < 0 error if the callback will never be called, otherwise
2414 * the result of the lock will be communicated via the callback.
2415 */
2416int ocfs2_inode_lock_full_nested(struct inode *inode,
2417 struct buffer_head **ret_bh,
2418 int ex,
2419 int arg_flags,
2420 int subclass)
2421{
2422 int status, level, acquired;
2423 u32 dlm_flags;
2424 struct ocfs2_lock_res *lockres = NULL;
2425 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2426 struct buffer_head *local_bh = NULL;
2427
2428 mlog(0, "inode %llu, take %s META lock\n",
2429 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2430 ex ? "EXMODE" : "PRMODE");
2431
2432 status = 0;
2433 acquired = 0;
2434 /* We'll allow faking a readonly metadata lock for
2435 * rodevices. */
2436 if (ocfs2_is_hard_readonly(osb)) {
2437 if (ex)
2438 status = -EROFS;
2439 goto getbh;
2440 }
2441
2442 if ((arg_flags & OCFS2_META_LOCK_GETBH) ||
2443 ocfs2_mount_local(osb))
2444 goto update;
2445
2446 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2447 ocfs2_wait_for_recovery(osb);
2448
2449 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2450 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2451 dlm_flags = 0;
2452 if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
2453 dlm_flags |= DLM_LKF_NOQUEUE;
2454
2455 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
2456 arg_flags, subclass, _RET_IP_);
2457 if (status < 0) {
2458 if (status != -EAGAIN)
2459 mlog_errno(status);
2460 goto bail;
2461 }
2462
2463 /* Notify the error cleanup path to drop the cluster lock. */
2464 acquired = 1;
2465
2466 /* We wait twice because a node may have died while we were in
2467 * the lower dlm layers. The second time though, we've
2468 * committed to owning this lock so we don't allow signals to
2469 * abort the operation. */
2470 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2471 ocfs2_wait_for_recovery(osb);
2472
2473update:
2474 /*
2475 * We only see this flag if we're being called from
2476 * ocfs2_read_locked_inode(). It means we're locking an inode
2477 * which hasn't been populated yet, so clear the refresh flag
2478 * and let the caller handle it.
2479 */
2480 if (inode->i_state & I_NEW) {
2481 status = 0;
2482 if (lockres)
2483 ocfs2_complete_lock_res_refresh(lockres, 0);
2484 goto bail;
2485 }
2486
2487 /* This is fun. The caller may want a bh back, or it may
2488 * not. ocfs2_inode_lock_update definitely wants one in, but
2489 * may or may not read one, depending on what's in the
2490 * LVB. The result of all of this is that we've *only* gone to
2491 * disk if we have to, so the complexity is worthwhile. */
2492 status = ocfs2_inode_lock_update(inode, &local_bh);
2493 if (status < 0) {
2494 if (status != -ENOENT)
2495 mlog_errno(status);
2496 goto bail;
2497 }
2498getbh:
2499 if (ret_bh) {
2500 status = ocfs2_assign_bh(inode, ret_bh, local_bh);
2501 if (status < 0) {
2502 mlog_errno(status);
2503 goto bail;
2504 }
2505 }
2506
2507bail:
2508 if (status < 0) {
2509 if (ret_bh && (*ret_bh)) {
2510 brelse(*ret_bh);
2511 *ret_bh = NULL;
2512 }
2513 if (acquired)
2514 ocfs2_inode_unlock(inode, ex);
2515 }
2516
2517 brelse(local_bh);
2518 return status;
2519}
2520
2521/*
2522 * This is working around a lock inversion between tasks acquiring DLM
2523 * locks while holding a page lock and the downconvert thread which
2524 * blocks dlm lock acquiry while acquiring page locks.
2525 *
2526 * ** These _with_page variantes are only intended to be called from aop
2527 * methods that hold page locks and return a very specific *positive* error
2528 * code that aop methods pass up to the VFS -- test for errors with != 0. **
2529 *
2530 * The DLM is called such that it returns -EAGAIN if it would have
2531 * blocked waiting for the downconvert thread. In that case we unlock
2532 * our page so the downconvert thread can make progress. Once we've
2533 * done this we have to return AOP_TRUNCATED_PAGE so the aop method
2534 * that called us can bubble that back up into the VFS who will then
2535 * immediately retry the aop call.
2536 */
2537int ocfs2_inode_lock_with_page(struct inode *inode,
2538 struct buffer_head **ret_bh,
2539 int ex,
2540 struct page *page)
2541{
2542 int ret;
2543
2544 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
2545 if (ret == -EAGAIN) {
2546 unlock_page(page);
2547 /*
2548 * If we can't get inode lock immediately, we should not return
2549 * directly here, since this will lead to a softlockup problem.
2550 * The method is to get a blocking lock and immediately unlock
2551 * before returning, this can avoid CPU resource waste due to
2552 * lots of retries, and benefits fairness in getting lock.
2553 */
2554 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
2555 ocfs2_inode_unlock(inode, ex);
2556 ret = AOP_TRUNCATED_PAGE;
2557 }
2558
2559 return ret;
2560}
2561
2562int ocfs2_inode_lock_atime(struct inode *inode,
2563 struct vfsmount *vfsmnt,
2564 int *level, int wait)
2565{
2566 int ret;
2567
2568 if (wait)
2569 ret = ocfs2_inode_lock(inode, NULL, 0);
2570 else
2571 ret = ocfs2_try_inode_lock(inode, NULL, 0);
2572
2573 if (ret < 0) {
2574 if (ret != -EAGAIN)
2575 mlog_errno(ret);
2576 return ret;
2577 }
2578
2579 /*
2580 * If we should update atime, we will get EX lock,
2581 * otherwise we just get PR lock.
2582 */
2583 if (ocfs2_should_update_atime(inode, vfsmnt)) {
2584 struct buffer_head *bh = NULL;
2585
2586 ocfs2_inode_unlock(inode, 0);
2587 if (wait)
2588 ret = ocfs2_inode_lock(inode, &bh, 1);
2589 else
2590 ret = ocfs2_try_inode_lock(inode, &bh, 1);
2591
2592 if (ret < 0) {
2593 if (ret != -EAGAIN)
2594 mlog_errno(ret);
2595 return ret;
2596 }
2597 *level = 1;
2598 if (ocfs2_should_update_atime(inode, vfsmnt))
2599 ocfs2_update_inode_atime(inode, bh);
2600 brelse(bh);
2601 } else
2602 *level = 0;
2603
2604 return ret;
2605}
2606
2607void ocfs2_inode_unlock(struct inode *inode,
2608 int ex)
2609{
2610 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2611 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
2612 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2613
2614 mlog(0, "inode %llu drop %s META lock\n",
2615 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2616 ex ? "EXMODE" : "PRMODE");
2617
2618 if (!ocfs2_is_hard_readonly(osb) &&
2619 !ocfs2_mount_local(osb))
2620 ocfs2_cluster_unlock(osb, lockres, level);
2621}
2622
2623/*
2624 * This _tracker variantes are introduced to deal with the recursive cluster
2625 * locking issue. The idea is to keep track of a lock holder on the stack of
2626 * the current process. If there's a lock holder on the stack, we know the
2627 * task context is already protected by cluster locking. Currently, they're
2628 * used in some VFS entry routines.
2629 *
2630 * return < 0 on error, return == 0 if there's no lock holder on the stack
2631 * before this call, return == 1 if this call would be a recursive locking.
2632 * return == -1 if this lock attempt will cause an upgrade which is forbidden.
2633 *
2634 * When taking lock levels into account,we face some different situations.
2635 *
2636 * 1. no lock is held
2637 * In this case, just lock the inode as requested and return 0
2638 *
2639 * 2. We are holding a lock
2640 * For this situation, things diverges into several cases
2641 *
2642 * wanted holding what to do
2643 * ex ex see 2.1 below
2644 * ex pr see 2.2 below
2645 * pr ex see 2.1 below
2646 * pr pr see 2.1 below
2647 *
2648 * 2.1 lock level that is been held is compatible
2649 * with the wanted level, so no lock action will be tacken.
2650 *
2651 * 2.2 Otherwise, an upgrade is needed, but it is forbidden.
2652 *
2653 * Reason why upgrade within a process is forbidden is that
2654 * lock upgrade may cause dead lock. The following illustrates
2655 * how it happens.
2656 *
2657 * thread on node1 thread on node2
2658 * ocfs2_inode_lock_tracker(ex=0)
2659 *
2660 * <====== ocfs2_inode_lock_tracker(ex=1)
2661 *
2662 * ocfs2_inode_lock_tracker(ex=1)
2663 */
2664int ocfs2_inode_lock_tracker(struct inode *inode,
2665 struct buffer_head **ret_bh,
2666 int ex,
2667 struct ocfs2_lock_holder *oh)
2668{
2669 int status = 0;
2670 struct ocfs2_lock_res *lockres;
2671 struct ocfs2_lock_holder *tmp_oh;
2672 struct pid *pid = task_pid(current);
2673
2674
2675 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2676 tmp_oh = ocfs2_pid_holder(lockres, pid);
2677
2678 if (!tmp_oh) {
2679 /*
2680 * This corresponds to the case 1.
2681 * We haven't got any lock before.
2682 */
2683 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0);
2684 if (status < 0) {
2685 if (status != -ENOENT)
2686 mlog_errno(status);
2687 return status;
2688 }
2689
2690 oh->oh_ex = ex;
2691 ocfs2_add_holder(lockres, oh);
2692 return 0;
2693 }
2694
2695 if (unlikely(ex && !tmp_oh->oh_ex)) {
2696 /*
2697 * case 2.2 upgrade may cause dead lock, forbid it.
2698 */
2699 mlog(ML_ERROR, "Recursive locking is not permitted to "
2700 "upgrade to EX level from PR level.\n");
2701 dump_stack();
2702 return -EINVAL;
2703 }
2704
2705 /*
2706 * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full.
2707 * ignore the lock level and just update it.
2708 */
2709 if (ret_bh) {
2710 status = ocfs2_inode_lock_full(inode, ret_bh, ex,
2711 OCFS2_META_LOCK_GETBH);
2712 if (status < 0) {
2713 if (status != -ENOENT)
2714 mlog_errno(status);
2715 return status;
2716 }
2717 }
2718 return tmp_oh ? 1 : 0;
2719}
2720
2721void ocfs2_inode_unlock_tracker(struct inode *inode,
2722 int ex,
2723 struct ocfs2_lock_holder *oh,
2724 int had_lock)
2725{
2726 struct ocfs2_lock_res *lockres;
2727
2728 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2729 /* had_lock means that the currect process already takes the cluster
2730 * lock previously.
2731 * If had_lock is 1, we have nothing to do here.
2732 * If had_lock is 0, we will release the lock.
2733 */
2734 if (!had_lock) {
2735 ocfs2_inode_unlock(inode, oh->oh_ex);
2736 ocfs2_remove_holder(lockres, oh);
2737 }
2738}
2739
2740int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
2741{
2742 struct ocfs2_lock_res *lockres;
2743 struct ocfs2_orphan_scan_lvb *lvb;
2744 int status = 0;
2745
2746 if (ocfs2_is_hard_readonly(osb))
2747 return -EROFS;
2748
2749 if (ocfs2_mount_local(osb))
2750 return 0;
2751
2752 lockres = &osb->osb_orphan_scan.os_lockres;
2753 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2754 if (status < 0)
2755 return status;
2756
2757 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2758 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2759 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
2760 *seqno = be32_to_cpu(lvb->lvb_os_seqno);
2761 else
2762 *seqno = osb->osb_orphan_scan.os_seqno + 1;
2763
2764 return status;
2765}
2766
2767void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
2768{
2769 struct ocfs2_lock_res *lockres;
2770 struct ocfs2_orphan_scan_lvb *lvb;
2771
2772 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
2773 lockres = &osb->osb_orphan_scan.os_lockres;
2774 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2775 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
2776 lvb->lvb_os_seqno = cpu_to_be32(seqno);
2777 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2778 }
2779}
2780
2781int ocfs2_super_lock(struct ocfs2_super *osb,
2782 int ex)
2783{
2784 int status = 0;
2785 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2786 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2787
2788 if (ocfs2_is_hard_readonly(osb))
2789 return -EROFS;
2790
2791 if (ocfs2_mount_local(osb))
2792 goto bail;
2793
2794 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
2795 if (status < 0) {
2796 mlog_errno(status);
2797 goto bail;
2798 }
2799
2800 /* The super block lock path is really in the best position to
2801 * know when resources covered by the lock need to be
2802 * refreshed, so we do it here. Of course, making sense of
2803 * everything is up to the caller :) */
2804 status = ocfs2_should_refresh_lock_res(lockres);
2805 if (status) {
2806 status = ocfs2_refresh_slot_info(osb);
2807
2808 ocfs2_complete_lock_res_refresh(lockres, status);
2809
2810 if (status < 0) {
2811 ocfs2_cluster_unlock(osb, lockres, level);
2812 mlog_errno(status);
2813 }
2814 ocfs2_track_lock_refresh(lockres);
2815 }
2816bail:
2817 return status;
2818}
2819
2820void ocfs2_super_unlock(struct ocfs2_super *osb,
2821 int ex)
2822{
2823 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2824 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2825
2826 if (!ocfs2_mount_local(osb))
2827 ocfs2_cluster_unlock(osb, lockres, level);
2828}
2829
2830int ocfs2_rename_lock(struct ocfs2_super *osb)
2831{
2832 int status;
2833 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2834
2835 if (ocfs2_is_hard_readonly(osb))
2836 return -EROFS;
2837
2838 if (ocfs2_mount_local(osb))
2839 return 0;
2840
2841 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2842 if (status < 0)
2843 mlog_errno(status);
2844
2845 return status;
2846}
2847
2848void ocfs2_rename_unlock(struct ocfs2_super *osb)
2849{
2850 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2851
2852 if (!ocfs2_mount_local(osb))
2853 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2854}
2855
2856int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
2857{
2858 int status;
2859 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2860
2861 if (ocfs2_is_hard_readonly(osb))
2862 return -EROFS;
2863
2864 if (ex)
2865 down_write(&osb->nfs_sync_rwlock);
2866 else
2867 down_read(&osb->nfs_sync_rwlock);
2868
2869 if (ocfs2_mount_local(osb))
2870 return 0;
2871
2872 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
2873 0, 0);
2874 if (status < 0) {
2875 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
2876
2877 if (ex)
2878 up_write(&osb->nfs_sync_rwlock);
2879 else
2880 up_read(&osb->nfs_sync_rwlock);
2881 }
2882
2883 return status;
2884}
2885
2886void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
2887{
2888 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2889
2890 if (!ocfs2_mount_local(osb))
2891 ocfs2_cluster_unlock(osb, lockres,
2892 ex ? LKM_EXMODE : LKM_PRMODE);
2893 if (ex)
2894 up_write(&osb->nfs_sync_rwlock);
2895 else
2896 up_read(&osb->nfs_sync_rwlock);
2897}
2898
2899int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
2900 struct ocfs2_trim_fs_info *info, int trylock)
2901{
2902 int status;
2903 struct ocfs2_trim_fs_lvb *lvb;
2904 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2905
2906 if (info)
2907 info->tf_valid = 0;
2908
2909 if (ocfs2_is_hard_readonly(osb))
2910 return -EROFS;
2911
2912 if (ocfs2_mount_local(osb))
2913 return 0;
2914
2915 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX,
2916 trylock ? DLM_LKF_NOQUEUE : 0, 0);
2917 if (status < 0) {
2918 if (status != -EAGAIN)
2919 mlog_errno(status);
2920 return status;
2921 }
2922
2923 if (info) {
2924 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2925 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2926 lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) {
2927 info->tf_valid = 1;
2928 info->tf_success = lvb->lvb_success;
2929 info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum);
2930 info->tf_start = be64_to_cpu(lvb->lvb_start);
2931 info->tf_len = be64_to_cpu(lvb->lvb_len);
2932 info->tf_minlen = be64_to_cpu(lvb->lvb_minlen);
2933 info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen);
2934 }
2935 }
2936
2937 return status;
2938}
2939
2940void ocfs2_trim_fs_unlock(struct ocfs2_super *osb,
2941 struct ocfs2_trim_fs_info *info)
2942{
2943 struct ocfs2_trim_fs_lvb *lvb;
2944 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2945
2946 if (ocfs2_mount_local(osb))
2947 return;
2948
2949 if (info) {
2950 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2951 lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION;
2952 lvb->lvb_success = info->tf_success;
2953 lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum);
2954 lvb->lvb_start = cpu_to_be64(info->tf_start);
2955 lvb->lvb_len = cpu_to_be64(info->tf_len);
2956 lvb->lvb_minlen = cpu_to_be64(info->tf_minlen);
2957 lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen);
2958 }
2959
2960 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2961}
2962
2963int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2964{
2965 int ret;
2966 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2967 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2968 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2969
2970 BUG_ON(!dl);
2971
2972 if (ocfs2_is_hard_readonly(osb)) {
2973 if (ex)
2974 return -EROFS;
2975 return 0;
2976 }
2977
2978 if (ocfs2_mount_local(osb))
2979 return 0;
2980
2981 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2982 if (ret < 0)
2983 mlog_errno(ret);
2984
2985 return ret;
2986}
2987
2988void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2989{
2990 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2991 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2992 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2993
2994 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
2995 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
2996}
2997
2998/* Reference counting of the dlm debug structure. We want this because
2999 * open references on the debug inodes can live on after a mount, so
3000 * we can't rely on the ocfs2_super to always exist. */
3001static void ocfs2_dlm_debug_free(struct kref *kref)
3002{
3003 struct ocfs2_dlm_debug *dlm_debug;
3004
3005 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
3006
3007 kfree(dlm_debug);
3008}
3009
3010void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
3011{
3012 if (dlm_debug)
3013 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
3014}
3015
3016static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
3017{
3018 kref_get(&debug->d_refcnt);
3019}
3020
3021struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
3022{
3023 struct ocfs2_dlm_debug *dlm_debug;
3024
3025 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
3026 if (!dlm_debug) {
3027 mlog_errno(-ENOMEM);
3028 goto out;
3029 }
3030
3031 kref_init(&dlm_debug->d_refcnt);
3032 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
3033 dlm_debug->d_filter_secs = 0;
3034out:
3035 return dlm_debug;
3036}
3037
3038/* Access to this is arbitrated for us via seq_file->sem. */
3039struct ocfs2_dlm_seq_priv {
3040 struct ocfs2_dlm_debug *p_dlm_debug;
3041 struct ocfs2_lock_res p_iter_res;
3042 struct ocfs2_lock_res p_tmp_res;
3043};
3044
3045static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
3046 struct ocfs2_dlm_seq_priv *priv)
3047{
3048 struct ocfs2_lock_res *iter, *ret = NULL;
3049 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
3050
3051 assert_spin_locked(&ocfs2_dlm_tracking_lock);
3052
3053 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
3054 /* discover the head of the list */
3055 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
3056 mlog(0, "End of list found, %p\n", ret);
3057 break;
3058 }
3059
3060 /* We track our "dummy" iteration lockres' by a NULL
3061 * l_ops field. */
3062 if (iter->l_ops != NULL) {
3063 ret = iter;
3064 break;
3065 }
3066 }
3067
3068 return ret;
3069}
3070
3071static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
3072{
3073 struct ocfs2_dlm_seq_priv *priv = m->private;
3074 struct ocfs2_lock_res *iter;
3075
3076 spin_lock(&ocfs2_dlm_tracking_lock);
3077 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
3078 if (iter) {
3079 /* Since lockres' have the lifetime of their container
3080 * (which can be inodes, ocfs2_supers, etc) we want to
3081 * copy this out to a temporary lockres while still
3082 * under the spinlock. Obviously after this we can't
3083 * trust any pointers on the copy returned, but that's
3084 * ok as the information we want isn't typically held
3085 * in them. */
3086 priv->p_tmp_res = *iter;
3087 iter = &priv->p_tmp_res;
3088 }
3089 spin_unlock(&ocfs2_dlm_tracking_lock);
3090
3091 return iter;
3092}
3093
3094static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
3095{
3096}
3097
3098static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
3099{
3100 struct ocfs2_dlm_seq_priv *priv = m->private;
3101 struct ocfs2_lock_res *iter = v;
3102 struct ocfs2_lock_res *dummy = &priv->p_iter_res;
3103
3104 spin_lock(&ocfs2_dlm_tracking_lock);
3105 iter = ocfs2_dlm_next_res(iter, priv);
3106 list_del_init(&dummy->l_debug_list);
3107 if (iter) {
3108 list_add(&dummy->l_debug_list, &iter->l_debug_list);
3109 priv->p_tmp_res = *iter;
3110 iter = &priv->p_tmp_res;
3111 }
3112 spin_unlock(&ocfs2_dlm_tracking_lock);
3113
3114 return iter;
3115}
3116
3117/*
3118 * Version is used by debugfs.ocfs2 to determine the format being used
3119 *
3120 * New in version 2
3121 * - Lock stats printed
3122 * New in version 3
3123 * - Max time in lock stats is in usecs (instead of nsecs)
3124 * New in version 4
3125 * - Add last pr/ex unlock times and first lock wait time in usecs
3126 */
3127#define OCFS2_DLM_DEBUG_STR_VERSION 4
3128static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
3129{
3130 int i;
3131 char *lvb;
3132 struct ocfs2_lock_res *lockres = v;
3133#ifdef CONFIG_OCFS2_FS_STATS
3134 u64 now, last;
3135 struct ocfs2_dlm_debug *dlm_debug =
3136 ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug;
3137#endif
3138
3139 if (!lockres)
3140 return -EINVAL;
3141
3142#ifdef CONFIG_OCFS2_FS_STATS
3143 if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) {
3144 now = ktime_to_us(ktime_get_real());
3145 if (lockres->l_lock_prmode.ls_last >
3146 lockres->l_lock_exmode.ls_last)
3147 last = lockres->l_lock_prmode.ls_last;
3148 else
3149 last = lockres->l_lock_exmode.ls_last;
3150 /*
3151 * Use d_filter_secs field to filter lock resources dump,
3152 * the default d_filter_secs(0) value filters nothing,
3153 * otherwise, only dump the last N seconds active lock
3154 * resources.
3155 */
3156 if (div_u64(now - last, 1000000) > dlm_debug->d_filter_secs)
3157 return 0;
3158 }
3159#endif
3160
3161 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
3162
3163 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
3164 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
3165 lockres->l_name,
3166 (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
3167 else
3168 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
3169
3170 seq_printf(m, "%d\t"
3171 "0x%lx\t"
3172 "0x%x\t"
3173 "0x%x\t"
3174 "%u\t"
3175 "%u\t"
3176 "%d\t"
3177 "%d\t",
3178 lockres->l_level,
3179 lockres->l_flags,
3180 lockres->l_action,
3181 lockres->l_unlock_action,
3182 lockres->l_ro_holders,
3183 lockres->l_ex_holders,
3184 lockres->l_requested,
3185 lockres->l_blocking);
3186
3187 /* Dump the raw LVB */
3188 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
3189 for(i = 0; i < DLM_LVB_LEN; i++)
3190 seq_printf(m, "0x%x\t", lvb[i]);
3191
3192#ifdef CONFIG_OCFS2_FS_STATS
3193# define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets)
3194# define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets)
3195# define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail)
3196# define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail)
3197# define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total)
3198# define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total)
3199# define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max)
3200# define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max)
3201# define lock_refresh(_l) ((_l)->l_lock_refresh)
3202# define lock_last_prmode(_l) ((_l)->l_lock_prmode.ls_last)
3203# define lock_last_exmode(_l) ((_l)->l_lock_exmode.ls_last)
3204# define lock_wait(_l) ((_l)->l_lock_wait)
3205#else
3206# define lock_num_prmode(_l) (0)
3207# define lock_num_exmode(_l) (0)
3208# define lock_num_prmode_failed(_l) (0)
3209# define lock_num_exmode_failed(_l) (0)
3210# define lock_total_prmode(_l) (0ULL)
3211# define lock_total_exmode(_l) (0ULL)
3212# define lock_max_prmode(_l) (0)
3213# define lock_max_exmode(_l) (0)
3214# define lock_refresh(_l) (0)
3215# define lock_last_prmode(_l) (0ULL)
3216# define lock_last_exmode(_l) (0ULL)
3217# define lock_wait(_l) (0ULL)
3218#endif
3219 /* The following seq_print was added in version 2 of this output */
3220 seq_printf(m, "%u\t"
3221 "%u\t"
3222 "%u\t"
3223 "%u\t"
3224 "%llu\t"
3225 "%llu\t"
3226 "%u\t"
3227 "%u\t"
3228 "%u\t"
3229 "%llu\t"
3230 "%llu\t"
3231 "%llu\t",
3232 lock_num_prmode(lockres),
3233 lock_num_exmode(lockres),
3234 lock_num_prmode_failed(lockres),
3235 lock_num_exmode_failed(lockres),
3236 lock_total_prmode(lockres),
3237 lock_total_exmode(lockres),
3238 lock_max_prmode(lockres),
3239 lock_max_exmode(lockres),
3240 lock_refresh(lockres),
3241 lock_last_prmode(lockres),
3242 lock_last_exmode(lockres),
3243 lock_wait(lockres));
3244
3245 /* End the line */
3246 seq_printf(m, "\n");
3247 return 0;
3248}
3249
3250static const struct seq_operations ocfs2_dlm_seq_ops = {
3251 .start = ocfs2_dlm_seq_start,
3252 .stop = ocfs2_dlm_seq_stop,
3253 .next = ocfs2_dlm_seq_next,
3254 .show = ocfs2_dlm_seq_show,
3255};
3256
3257static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
3258{
3259 struct seq_file *seq = file->private_data;
3260 struct ocfs2_dlm_seq_priv *priv = seq->private;
3261 struct ocfs2_lock_res *res = &priv->p_iter_res;
3262
3263 ocfs2_remove_lockres_tracking(res);
3264 ocfs2_put_dlm_debug(priv->p_dlm_debug);
3265 return seq_release_private(inode, file);
3266}
3267
3268static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
3269{
3270 struct ocfs2_dlm_seq_priv *priv;
3271 struct ocfs2_super *osb;
3272
3273 priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv));
3274 if (!priv) {
3275 mlog_errno(-ENOMEM);
3276 return -ENOMEM;
3277 }
3278
3279 osb = inode->i_private;
3280 ocfs2_get_dlm_debug(osb->osb_dlm_debug);
3281 priv->p_dlm_debug = osb->osb_dlm_debug;
3282 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
3283
3284 ocfs2_add_lockres_tracking(&priv->p_iter_res,
3285 priv->p_dlm_debug);
3286
3287 return 0;
3288}
3289
3290static const struct file_operations ocfs2_dlm_debug_fops = {
3291 .open = ocfs2_dlm_debug_open,
3292 .release = ocfs2_dlm_debug_release,
3293 .read = seq_read,
3294 .llseek = seq_lseek,
3295};
3296
3297static void ocfs2_dlm_init_debug(struct ocfs2_super *osb)
3298{
3299 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
3300
3301 debugfs_create_file("locking_state", S_IFREG|S_IRUSR,
3302 osb->osb_debug_root, osb, &ocfs2_dlm_debug_fops);
3303
3304 debugfs_create_u32("locking_filter", 0600, osb->osb_debug_root,
3305 &dlm_debug->d_filter_secs);
3306 ocfs2_get_dlm_debug(dlm_debug);
3307}
3308
3309static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
3310{
3311 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
3312
3313 if (dlm_debug)
3314 ocfs2_put_dlm_debug(dlm_debug);
3315}
3316
3317int ocfs2_dlm_init(struct ocfs2_super *osb)
3318{
3319 int status = 0;
3320 struct ocfs2_cluster_connection *conn = NULL;
3321
3322 if (ocfs2_mount_local(osb)) {
3323 osb->node_num = 0;
3324 goto local;
3325 }
3326
3327 ocfs2_dlm_init_debug(osb);
3328
3329 /* launch downconvert thread */
3330 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s",
3331 osb->uuid_str);
3332 if (IS_ERR(osb->dc_task)) {
3333 status = PTR_ERR(osb->dc_task);
3334 osb->dc_task = NULL;
3335 mlog_errno(status);
3336 goto bail;
3337 }
3338
3339 /* for now, uuid == domain */
3340 status = ocfs2_cluster_connect(osb->osb_cluster_stack,
3341 osb->osb_cluster_name,
3342 strlen(osb->osb_cluster_name),
3343 osb->uuid_str,
3344 strlen(osb->uuid_str),
3345 &lproto, ocfs2_do_node_down, osb,
3346 &conn);
3347 if (status) {
3348 mlog_errno(status);
3349 goto bail;
3350 }
3351
3352 status = ocfs2_cluster_this_node(conn, &osb->node_num);
3353 if (status < 0) {
3354 mlog_errno(status);
3355 mlog(ML_ERROR,
3356 "could not find this host's node number\n");
3357 ocfs2_cluster_disconnect(conn, 0);
3358 goto bail;
3359 }
3360
3361local:
3362 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
3363 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
3364 ocfs2_nfs_sync_lock_init(osb);
3365 ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
3366
3367 osb->cconn = conn;
3368bail:
3369 if (status < 0) {
3370 ocfs2_dlm_shutdown_debug(osb);
3371 if (osb->dc_task)
3372 kthread_stop(osb->dc_task);
3373 }
3374
3375 return status;
3376}
3377
3378void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
3379 int hangup_pending)
3380{
3381 ocfs2_drop_osb_locks(osb);
3382
3383 /*
3384 * Now that we have dropped all locks and ocfs2_dismount_volume()
3385 * has disabled recovery, the DLM won't be talking to us. It's
3386 * safe to tear things down before disconnecting the cluster.
3387 */
3388
3389 if (osb->dc_task) {
3390 kthread_stop(osb->dc_task);
3391 osb->dc_task = NULL;
3392 }
3393
3394 ocfs2_lock_res_free(&osb->osb_super_lockres);
3395 ocfs2_lock_res_free(&osb->osb_rename_lockres);
3396 ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
3397 ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
3398
3399 ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
3400 osb->cconn = NULL;
3401
3402 ocfs2_dlm_shutdown_debug(osb);
3403}
3404
3405static int ocfs2_drop_lock(struct ocfs2_super *osb,
3406 struct ocfs2_lock_res *lockres)
3407{
3408 int ret;
3409 unsigned long flags;
3410 u32 lkm_flags = 0;
3411
3412 /* We didn't get anywhere near actually using this lockres. */
3413 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
3414 goto out;
3415
3416 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3417 lkm_flags |= DLM_LKF_VALBLK;
3418
3419 spin_lock_irqsave(&lockres->l_lock, flags);
3420
3421 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
3422 "lockres %s, flags 0x%lx\n",
3423 lockres->l_name, lockres->l_flags);
3424
3425 while (lockres->l_flags & OCFS2_LOCK_BUSY) {
3426 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
3427 "%u, unlock_action = %u\n",
3428 lockres->l_name, lockres->l_flags, lockres->l_action,
3429 lockres->l_unlock_action);
3430
3431 spin_unlock_irqrestore(&lockres->l_lock, flags);
3432
3433 /* XXX: Today we just wait on any busy
3434 * locks... Perhaps we need to cancel converts in the
3435 * future? */
3436 ocfs2_wait_on_busy_lock(lockres);
3437
3438 spin_lock_irqsave(&lockres->l_lock, flags);
3439 }
3440
3441 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3442 if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
3443 lockres->l_level == DLM_LOCK_EX &&
3444 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3445 lockres->l_ops->set_lvb(lockres);
3446 }
3447
3448 if (lockres->l_flags & OCFS2_LOCK_BUSY)
3449 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
3450 lockres->l_name);
3451 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
3452 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
3453
3454 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
3455 spin_unlock_irqrestore(&lockres->l_lock, flags);
3456 goto out;
3457 }
3458
3459 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
3460
3461 /* make sure we never get here while waiting for an ast to
3462 * fire. */
3463 BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
3464
3465 /* is this necessary? */
3466 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3467 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
3468 spin_unlock_irqrestore(&lockres->l_lock, flags);
3469
3470 mlog(0, "lock %s\n", lockres->l_name);
3471
3472 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags);
3473 if (ret) {
3474 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3475 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
3476 ocfs2_dlm_dump_lksb(&lockres->l_lksb);
3477 BUG();
3478 }
3479 mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n",
3480 lockres->l_name);
3481
3482 ocfs2_wait_on_busy_lock(lockres);
3483out:
3484 return 0;
3485}
3486
3487static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3488 struct ocfs2_lock_res *lockres);
3489
3490/* Mark the lockres as being dropped. It will no longer be
3491 * queued if blocking, but we still may have to wait on it
3492 * being dequeued from the downconvert thread before we can consider
3493 * it safe to drop.
3494 *
3495 * You can *not* attempt to call cluster_lock on this lockres anymore. */
3496void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb,
3497 struct ocfs2_lock_res *lockres)
3498{
3499 int status;
3500 struct ocfs2_mask_waiter mw;
3501 unsigned long flags, flags2;
3502
3503 ocfs2_init_mask_waiter(&mw);
3504
3505 spin_lock_irqsave(&lockres->l_lock, flags);
3506 lockres->l_flags |= OCFS2_LOCK_FREEING;
3507 if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) {
3508 /*
3509 * We know the downconvert is queued but not in progress
3510 * because we are the downconvert thread and processing
3511 * different lock. So we can just remove the lock from the
3512 * queue. This is not only an optimization but also a way
3513 * to avoid the following deadlock:
3514 * ocfs2_dentry_post_unlock()
3515 * ocfs2_dentry_lock_put()
3516 * ocfs2_drop_dentry_lock()
3517 * iput()
3518 * ocfs2_evict_inode()
3519 * ocfs2_clear_inode()
3520 * ocfs2_mark_lockres_freeing()
3521 * ... blocks waiting for OCFS2_LOCK_QUEUED
3522 * since we are the downconvert thread which
3523 * should clear the flag.
3524 */
3525 spin_unlock_irqrestore(&lockres->l_lock, flags);
3526 spin_lock_irqsave(&osb->dc_task_lock, flags2);
3527 list_del_init(&lockres->l_blocked_list);
3528 osb->blocked_lock_count--;
3529 spin_unlock_irqrestore(&osb->dc_task_lock, flags2);
3530 /*
3531 * Warn if we recurse into another post_unlock call. Strictly
3532 * speaking it isn't a problem but we need to be careful if
3533 * that happens (stack overflow, deadlocks, ...) so warn if
3534 * ocfs2 grows a path for which this can happen.
3535 */
3536 WARN_ON_ONCE(lockres->l_ops->post_unlock);
3537 /* Since the lock is freeing we don't do much in the fn below */
3538 ocfs2_process_blocked_lock(osb, lockres);
3539 return;
3540 }
3541 while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
3542 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
3543 spin_unlock_irqrestore(&lockres->l_lock, flags);
3544
3545 mlog(0, "Waiting on lockres %s\n", lockres->l_name);
3546
3547 status = ocfs2_wait_for_mask(&mw);
3548 if (status)
3549 mlog_errno(status);
3550
3551 spin_lock_irqsave(&lockres->l_lock, flags);
3552 }
3553 spin_unlock_irqrestore(&lockres->l_lock, flags);
3554}
3555
3556void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
3557 struct ocfs2_lock_res *lockres)
3558{
3559 int ret;
3560
3561 ocfs2_mark_lockres_freeing(osb, lockres);
3562 ret = ocfs2_drop_lock(osb, lockres);
3563 if (ret)
3564 mlog_errno(ret);
3565}
3566
3567static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
3568{
3569 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
3570 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
3571 ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
3572 ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
3573}
3574
3575int ocfs2_drop_inode_locks(struct inode *inode)
3576{
3577 int status, err;
3578
3579 /* No need to call ocfs2_mark_lockres_freeing here -
3580 * ocfs2_clear_inode has done it for us. */
3581
3582 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3583 &OCFS2_I(inode)->ip_open_lockres);
3584 if (err < 0)
3585 mlog_errno(err);
3586
3587 status = err;
3588
3589 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3590 &OCFS2_I(inode)->ip_inode_lockres);
3591 if (err < 0)
3592 mlog_errno(err);
3593 if (err < 0 && !status)
3594 status = err;
3595
3596 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3597 &OCFS2_I(inode)->ip_rw_lockres);
3598 if (err < 0)
3599 mlog_errno(err);
3600 if (err < 0 && !status)
3601 status = err;
3602
3603 return status;
3604}
3605
3606static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
3607 int new_level)
3608{
3609 assert_spin_locked(&lockres->l_lock);
3610
3611 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
3612
3613 if (lockres->l_level <= new_level) {
3614 mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
3615 "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
3616 "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
3617 new_level, list_empty(&lockres->l_blocked_list),
3618 list_empty(&lockres->l_mask_waiters), lockres->l_type,
3619 lockres->l_flags, lockres->l_ro_holders,
3620 lockres->l_ex_holders, lockres->l_action,
3621 lockres->l_unlock_action, lockres->l_requested,
3622 lockres->l_blocking, lockres->l_pending_gen);
3623 BUG();
3624 }
3625
3626 mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
3627 lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
3628
3629 lockres->l_action = OCFS2_AST_DOWNCONVERT;
3630 lockres->l_requested = new_level;
3631 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3632 return lockres_set_pending(lockres);
3633}
3634
3635static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
3636 struct ocfs2_lock_res *lockres,
3637 int new_level,
3638 int lvb,
3639 unsigned int generation)
3640{
3641 int ret;
3642 u32 dlm_flags = DLM_LKF_CONVERT;
3643
3644 mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
3645 lockres->l_level, new_level);
3646
3647 /*
3648 * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always
3649 * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that
3650 * we can recover correctly from node failure. Otherwise, we may get
3651 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set.
3652 */
3653 if (ocfs2_userspace_stack(osb) &&
3654 lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3655 lvb = 1;
3656
3657 if (lvb)
3658 dlm_flags |= DLM_LKF_VALBLK;
3659
3660 ret = ocfs2_dlm_lock(osb->cconn,
3661 new_level,
3662 &lockres->l_lksb,
3663 dlm_flags,
3664 lockres->l_name,
3665 OCFS2_LOCK_ID_MAX_LEN - 1);
3666 lockres_clear_pending(lockres, generation, osb);
3667 if (ret) {
3668 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
3669 ocfs2_recover_from_dlm_error(lockres, 1);
3670 goto bail;
3671 }
3672
3673 ret = 0;
3674bail:
3675 return ret;
3676}
3677
3678/* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */
3679static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
3680 struct ocfs2_lock_res *lockres)
3681{
3682 assert_spin_locked(&lockres->l_lock);
3683
3684 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
3685 /* If we're already trying to cancel a lock conversion
3686 * then just drop the spinlock and allow the caller to
3687 * requeue this lock. */
3688 mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
3689 return 0;
3690 }
3691
3692 /* were we in a convert when we got the bast fire? */
3693 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
3694 lockres->l_action != OCFS2_AST_DOWNCONVERT);
3695 /* set things up for the unlockast to know to just
3696 * clear out the ast_action and unset busy, etc. */
3697 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
3698
3699 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
3700 "lock %s, invalid flags: 0x%lx\n",
3701 lockres->l_name, lockres->l_flags);
3702
3703 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3704
3705 return 1;
3706}
3707
3708static int ocfs2_cancel_convert(struct ocfs2_super *osb,
3709 struct ocfs2_lock_res *lockres)
3710{
3711 int ret;
3712
3713 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
3714 DLM_LKF_CANCEL);
3715 if (ret) {
3716 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3717 ocfs2_recover_from_dlm_error(lockres, 0);
3718 }
3719
3720 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3721
3722 return ret;
3723}
3724
3725static int ocfs2_unblock_lock(struct ocfs2_super *osb,
3726 struct ocfs2_lock_res *lockres,
3727 struct ocfs2_unblock_ctl *ctl)
3728{
3729 unsigned long flags;
3730 int blocking;
3731 int new_level;
3732 int level;
3733 int ret = 0;
3734 int set_lvb = 0;
3735 unsigned int gen;
3736
3737 spin_lock_irqsave(&lockres->l_lock, flags);
3738
3739recheck:
3740 /*
3741 * Is it still blocking? If not, we have no more work to do.
3742 */
3743 if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
3744 BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
3745 spin_unlock_irqrestore(&lockres->l_lock, flags);
3746 ret = 0;
3747 goto leave;
3748 }
3749
3750 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
3751 /* XXX
3752 * This is a *big* race. The OCFS2_LOCK_PENDING flag
3753 * exists entirely for one reason - another thread has set
3754 * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock().
3755 *
3756 * If we do ocfs2_cancel_convert() before the other thread
3757 * calls dlm_lock(), our cancel will do nothing. We will
3758 * get no ast, and we will have no way of knowing the
3759 * cancel failed. Meanwhile, the other thread will call
3760 * into dlm_lock() and wait...forever.
3761 *
3762 * Why forever? Because another node has asked for the
3763 * lock first; that's why we're here in unblock_lock().
3764 *
3765 * The solution is OCFS2_LOCK_PENDING. When PENDING is
3766 * set, we just requeue the unblock. Only when the other
3767 * thread has called dlm_lock() and cleared PENDING will
3768 * we then cancel their request.
3769 *
3770 * All callers of dlm_lock() must set OCFS2_DLM_PENDING
3771 * at the same time they set OCFS2_DLM_BUSY. They must
3772 * clear OCFS2_DLM_PENDING after dlm_lock() returns.
3773 */
3774 if (lockres->l_flags & OCFS2_LOCK_PENDING) {
3775 mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
3776 lockres->l_name);
3777 goto leave_requeue;
3778 }
3779
3780 ctl->requeue = 1;
3781 ret = ocfs2_prepare_cancel_convert(osb, lockres);
3782 spin_unlock_irqrestore(&lockres->l_lock, flags);
3783 if (ret) {
3784 ret = ocfs2_cancel_convert(osb, lockres);
3785 if (ret < 0)
3786 mlog_errno(ret);
3787 }
3788 goto leave;
3789 }
3790
3791 /*
3792 * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is
3793 * set when the ast is received for an upconvert just before the
3794 * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast
3795 * on the heels of the ast, we want to delay the downconvert just
3796 * enough to allow the up requestor to do its task. Because this
3797 * lock is in the blocked queue, the lock will be downconverted
3798 * as soon as the requestor is done with the lock.
3799 */
3800 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING)
3801 goto leave_requeue;
3802
3803 /*
3804 * How can we block and yet be at NL? We were trying to upconvert
3805 * from NL and got canceled. The code comes back here, and now
3806 * we notice and clear BLOCKING.
3807 */
3808 if (lockres->l_level == DLM_LOCK_NL) {
3809 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
3810 mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
3811 lockres->l_blocking = DLM_LOCK_NL;
3812 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
3813 spin_unlock_irqrestore(&lockres->l_lock, flags);
3814 goto leave;
3815 }
3816
3817 /* if we're blocking an exclusive and we have *any* holders,
3818 * then requeue. */
3819 if ((lockres->l_blocking == DLM_LOCK_EX)
3820 && (lockres->l_ex_holders || lockres->l_ro_holders)) {
3821 mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
3822 lockres->l_name, lockres->l_ex_holders,
3823 lockres->l_ro_holders);
3824 goto leave_requeue;
3825 }
3826
3827 /* If it's a PR we're blocking, then only
3828 * requeue if we've got any EX holders */
3829 if (lockres->l_blocking == DLM_LOCK_PR &&
3830 lockres->l_ex_holders) {
3831 mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
3832 lockres->l_name, lockres->l_ex_holders);
3833 goto leave_requeue;
3834 }
3835
3836 /*
3837 * Can we get a lock in this state if the holder counts are
3838 * zero? The meta data unblock code used to check this.
3839 */
3840 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
3841 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
3842 mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
3843 lockres->l_name);
3844 goto leave_requeue;
3845 }
3846
3847 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
3848
3849 if (lockres->l_ops->check_downconvert
3850 && !lockres->l_ops->check_downconvert(lockres, new_level)) {
3851 mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
3852 lockres->l_name);
3853 goto leave_requeue;
3854 }
3855
3856 /* If we get here, then we know that there are no more
3857 * incompatible holders (and anyone asking for an incompatible
3858 * lock is blocked). We can now downconvert the lock */
3859 if (!lockres->l_ops->downconvert_worker)
3860 goto downconvert;
3861
3862 /* Some lockres types want to do a bit of work before
3863 * downconverting a lock. Allow that here. The worker function
3864 * may sleep, so we save off a copy of what we're blocking as
3865 * it may change while we're not holding the spin lock. */
3866 blocking = lockres->l_blocking;
3867 level = lockres->l_level;
3868 spin_unlock_irqrestore(&lockres->l_lock, flags);
3869
3870 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
3871
3872 if (ctl->unblock_action == UNBLOCK_STOP_POST) {
3873 mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
3874 lockres->l_name);
3875 goto leave;
3876 }
3877
3878 spin_lock_irqsave(&lockres->l_lock, flags);
3879 if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
3880 /* If this changed underneath us, then we can't drop
3881 * it just yet. */
3882 mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
3883 "Recheck\n", lockres->l_name, blocking,
3884 lockres->l_blocking, level, lockres->l_level);
3885 goto recheck;
3886 }
3887
3888downconvert:
3889 ctl->requeue = 0;
3890
3891 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3892 if (lockres->l_level == DLM_LOCK_EX)
3893 set_lvb = 1;
3894
3895 /*
3896 * We only set the lvb if the lock has been fully
3897 * refreshed - otherwise we risk setting stale
3898 * data. Otherwise, there's no need to actually clear
3899 * out the lvb here as it's value is still valid.
3900 */
3901 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3902 lockres->l_ops->set_lvb(lockres);
3903 }
3904
3905 gen = ocfs2_prepare_downconvert(lockres, new_level);
3906 spin_unlock_irqrestore(&lockres->l_lock, flags);
3907 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
3908 gen);
3909
3910leave:
3911 if (ret)
3912 mlog_errno(ret);
3913 return ret;
3914
3915leave_requeue:
3916 spin_unlock_irqrestore(&lockres->l_lock, flags);
3917 ctl->requeue = 1;
3918
3919 return 0;
3920}
3921
3922static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
3923 int blocking)
3924{
3925 struct inode *inode;
3926 struct address_space *mapping;
3927 struct ocfs2_inode_info *oi;
3928
3929 inode = ocfs2_lock_res_inode(lockres);
3930 mapping = inode->i_mapping;
3931
3932 if (S_ISDIR(inode->i_mode)) {
3933 oi = OCFS2_I(inode);
3934 oi->ip_dir_lock_gen++;
3935 mlog(0, "generation: %u\n", oi->ip_dir_lock_gen);
3936 goto out;
3937 }
3938
3939 if (!S_ISREG(inode->i_mode))
3940 goto out;
3941
3942 /*
3943 * We need this before the filemap_fdatawrite() so that it can
3944 * transfer the dirty bit from the PTE to the
3945 * page. Unfortunately this means that even for EX->PR
3946 * downconverts, we'll lose our mappings and have to build
3947 * them up again.
3948 */
3949 unmap_mapping_range(mapping, 0, 0, 0);
3950
3951 if (filemap_fdatawrite(mapping)) {
3952 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
3953 (unsigned long long)OCFS2_I(inode)->ip_blkno);
3954 }
3955 sync_mapping_buffers(mapping);
3956 if (blocking == DLM_LOCK_EX) {
3957 truncate_inode_pages(mapping, 0);
3958 } else {
3959 /* We only need to wait on the I/O if we're not also
3960 * truncating pages because truncate_inode_pages waits
3961 * for us above. We don't truncate pages if we're
3962 * blocking anything < EXMODE because we want to keep
3963 * them around in that case. */
3964 filemap_fdatawait(mapping);
3965 }
3966
3967 forget_all_cached_acls(inode);
3968
3969out:
3970 return UNBLOCK_CONTINUE;
3971}
3972
3973static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci,
3974 struct ocfs2_lock_res *lockres,
3975 int new_level)
3976{
3977 int checkpointed = ocfs2_ci_fully_checkpointed(ci);
3978
3979 BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
3980 BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
3981
3982 if (checkpointed)
3983 return 1;
3984
3985 ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci)));
3986 return 0;
3987}
3988
3989static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
3990 int new_level)
3991{
3992 struct inode *inode = ocfs2_lock_res_inode(lockres);
3993
3994 return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level);
3995}
3996
3997static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
3998{
3999 struct inode *inode = ocfs2_lock_res_inode(lockres);
4000
4001 __ocfs2_stuff_meta_lvb(inode);
4002}
4003
4004/*
4005 * Does the final reference drop on our dentry lock. Right now this
4006 * happens in the downconvert thread, but we could choose to simplify the
4007 * dlmglue API and push these off to the ocfs2_wq in the future.
4008 */
4009static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
4010 struct ocfs2_lock_res *lockres)
4011{
4012 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
4013 ocfs2_dentry_lock_put(osb, dl);
4014}
4015
4016/*
4017 * d_delete() matching dentries before the lock downconvert.
4018 *
4019 * At this point, any process waiting to destroy the
4020 * dentry_lock due to last ref count is stopped by the
4021 * OCFS2_LOCK_QUEUED flag.
4022 *
4023 * We have two potential problems
4024 *
4025 * 1) If we do the last reference drop on our dentry_lock (via dput)
4026 * we'll wind up in ocfs2_release_dentry_lock(), waiting on
4027 * the downconvert to finish. Instead we take an elevated
4028 * reference and push the drop until after we've completed our
4029 * unblock processing.
4030 *
4031 * 2) There might be another process with a final reference,
4032 * waiting on us to finish processing. If this is the case, we
4033 * detect it and exit out - there's no more dentries anyway.
4034 */
4035static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
4036 int blocking)
4037{
4038 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
4039 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
4040 struct dentry *dentry;
4041 unsigned long flags;
4042 int extra_ref = 0;
4043
4044 /*
4045 * This node is blocking another node from getting a read
4046 * lock. This happens when we've renamed within a
4047 * directory. We've forced the other nodes to d_delete(), but
4048 * we never actually dropped our lock because it's still
4049 * valid. The downconvert code will retain a PR for this node,
4050 * so there's no further work to do.
4051 */
4052 if (blocking == DLM_LOCK_PR)
4053 return UNBLOCK_CONTINUE;
4054
4055 /*
4056 * Mark this inode as potentially orphaned. The code in
4057 * ocfs2_delete_inode() will figure out whether it actually
4058 * needs to be freed or not.
4059 */
4060 spin_lock(&oi->ip_lock);
4061 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
4062 spin_unlock(&oi->ip_lock);
4063
4064 /*
4065 * Yuck. We need to make sure however that the check of
4066 * OCFS2_LOCK_FREEING and the extra reference are atomic with
4067 * respect to a reference decrement or the setting of that
4068 * flag.
4069 */
4070 spin_lock_irqsave(&lockres->l_lock, flags);
4071 spin_lock(&dentry_attach_lock);
4072 if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
4073 && dl->dl_count) {
4074 dl->dl_count++;
4075 extra_ref = 1;
4076 }
4077 spin_unlock(&dentry_attach_lock);
4078 spin_unlock_irqrestore(&lockres->l_lock, flags);
4079
4080 mlog(0, "extra_ref = %d\n", extra_ref);
4081
4082 /*
4083 * We have a process waiting on us in ocfs2_dentry_iput(),
4084 * which means we can't have any more outstanding
4085 * aliases. There's no need to do any more work.
4086 */
4087 if (!extra_ref)
4088 return UNBLOCK_CONTINUE;
4089
4090 spin_lock(&dentry_attach_lock);
4091 while (1) {
4092 dentry = ocfs2_find_local_alias(dl->dl_inode,
4093 dl->dl_parent_blkno, 1);
4094 if (!dentry)
4095 break;
4096 spin_unlock(&dentry_attach_lock);
4097
4098 if (S_ISDIR(dl->dl_inode->i_mode))
4099 shrink_dcache_parent(dentry);
4100
4101 mlog(0, "d_delete(%pd);\n", dentry);
4102
4103 /*
4104 * The following dcache calls may do an
4105 * iput(). Normally we don't want that from the
4106 * downconverting thread, but in this case it's ok
4107 * because the requesting node already has an
4108 * exclusive lock on the inode, so it can't be queued
4109 * for a downconvert.
4110 */
4111 d_delete(dentry);
4112 dput(dentry);
4113
4114 spin_lock(&dentry_attach_lock);
4115 }
4116 spin_unlock(&dentry_attach_lock);
4117
4118 /*
4119 * If we are the last holder of this dentry lock, there is no
4120 * reason to downconvert so skip straight to the unlock.
4121 */
4122 if (dl->dl_count == 1)
4123 return UNBLOCK_STOP_POST;
4124
4125 return UNBLOCK_CONTINUE_POST;
4126}
4127
4128static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
4129 int new_level)
4130{
4131 struct ocfs2_refcount_tree *tree =
4132 ocfs2_lock_res_refcount_tree(lockres);
4133
4134 return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level);
4135}
4136
4137static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
4138 int blocking)
4139{
4140 struct ocfs2_refcount_tree *tree =
4141 ocfs2_lock_res_refcount_tree(lockres);
4142
4143 ocfs2_metadata_cache_purge(&tree->rf_ci);
4144
4145 return UNBLOCK_CONTINUE;
4146}
4147
4148static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
4149{
4150 struct ocfs2_qinfo_lvb *lvb;
4151 struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
4152 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
4153 oinfo->dqi_gi.dqi_type);
4154
4155 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
4156 lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
4157 lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
4158 lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
4159 lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
4160 lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
4161 lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
4162 lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
4163}
4164
4165void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
4166{
4167 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4168 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
4169 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4170
4171 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
4172 ocfs2_cluster_unlock(osb, lockres, level);
4173}
4174
4175static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
4176{
4177 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
4178 oinfo->dqi_gi.dqi_type);
4179 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4180 struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
4181 struct buffer_head *bh = NULL;
4182 struct ocfs2_global_disk_dqinfo *gdinfo;
4183 int status = 0;
4184
4185 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
4186 lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
4187 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
4188 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
4189 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
4190 oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
4191 oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
4192 oinfo->dqi_gi.dqi_free_entry =
4193 be32_to_cpu(lvb->lvb_free_entry);
4194 } else {
4195 status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode,
4196 oinfo->dqi_giblk, &bh);
4197 if (status) {
4198 mlog_errno(status);
4199 goto bail;
4200 }
4201 gdinfo = (struct ocfs2_global_disk_dqinfo *)
4202 (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
4203 info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
4204 info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
4205 oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
4206 oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
4207 oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
4208 oinfo->dqi_gi.dqi_free_entry =
4209 le32_to_cpu(gdinfo->dqi_free_entry);
4210 brelse(bh);
4211 ocfs2_track_lock_refresh(lockres);
4212 }
4213
4214bail:
4215 return status;
4216}
4217
4218/* Lock quota info, this function expects at least shared lock on the quota file
4219 * so that we can safely refresh quota info from disk. */
4220int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
4221{
4222 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4223 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
4224 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4225 int status = 0;
4226
4227 /* On RO devices, locking really isn't needed... */
4228 if (ocfs2_is_hard_readonly(osb)) {
4229 if (ex)
4230 status = -EROFS;
4231 goto bail;
4232 }
4233 if (ocfs2_mount_local(osb))
4234 goto bail;
4235
4236 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
4237 if (status < 0) {
4238 mlog_errno(status);
4239 goto bail;
4240 }
4241 if (!ocfs2_should_refresh_lock_res(lockres))
4242 goto bail;
4243 /* OK, we have the lock but we need to refresh the quota info */
4244 status = ocfs2_refresh_qinfo(oinfo);
4245 if (status)
4246 ocfs2_qinfo_unlock(oinfo, ex);
4247 ocfs2_complete_lock_res_refresh(lockres, status);
4248bail:
4249 return status;
4250}
4251
4252int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex)
4253{
4254 int status;
4255 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4256 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
4257 struct ocfs2_super *osb = lockres->l_priv;
4258
4259
4260 if (ocfs2_is_hard_readonly(osb))
4261 return -EROFS;
4262
4263 if (ocfs2_mount_local(osb))
4264 return 0;
4265
4266 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
4267 if (status < 0)
4268 mlog_errno(status);
4269
4270 return status;
4271}
4272
4273void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
4274{
4275 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4276 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
4277 struct ocfs2_super *osb = lockres->l_priv;
4278
4279 if (!ocfs2_mount_local(osb))
4280 ocfs2_cluster_unlock(osb, lockres, level);
4281}
4282
4283static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
4284 struct ocfs2_lock_res *lockres)
4285{
4286 int status;
4287 struct ocfs2_unblock_ctl ctl = {0, 0,};
4288 unsigned long flags;
4289
4290 /* Our reference to the lockres in this function can be
4291 * considered valid until we remove the OCFS2_LOCK_QUEUED
4292 * flag. */
4293
4294 BUG_ON(!lockres);
4295 BUG_ON(!lockres->l_ops);
4296
4297 mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
4298
4299 /* Detect whether a lock has been marked as going away while
4300 * the downconvert thread was processing other things. A lock can
4301 * still be marked with OCFS2_LOCK_FREEING after this check,
4302 * but short circuiting here will still save us some
4303 * performance. */
4304 spin_lock_irqsave(&lockres->l_lock, flags);
4305 if (lockres->l_flags & OCFS2_LOCK_FREEING)
4306 goto unqueue;
4307 spin_unlock_irqrestore(&lockres->l_lock, flags);
4308
4309 status = ocfs2_unblock_lock(osb, lockres, &ctl);
4310 if (status < 0)
4311 mlog_errno(status);
4312
4313 spin_lock_irqsave(&lockres->l_lock, flags);
4314unqueue:
4315 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
4316 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
4317 } else
4318 ocfs2_schedule_blocked_lock(osb, lockres);
4319
4320 mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
4321 ctl.requeue ? "yes" : "no");
4322 spin_unlock_irqrestore(&lockres->l_lock, flags);
4323
4324 if (ctl.unblock_action != UNBLOCK_CONTINUE
4325 && lockres->l_ops->post_unlock)
4326 lockres->l_ops->post_unlock(osb, lockres);
4327}
4328
4329static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
4330 struct ocfs2_lock_res *lockres)
4331{
4332 unsigned long flags;
4333
4334 assert_spin_locked(&lockres->l_lock);
4335
4336 if (lockres->l_flags & OCFS2_LOCK_FREEING) {
4337 /* Do not schedule a lock for downconvert when it's on
4338 * the way to destruction - any nodes wanting access
4339 * to the resource will get it soon. */
4340 mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
4341 lockres->l_name, lockres->l_flags);
4342 return;
4343 }
4344
4345 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
4346
4347 spin_lock_irqsave(&osb->dc_task_lock, flags);
4348 if (list_empty(&lockres->l_blocked_list)) {
4349 list_add_tail(&lockres->l_blocked_list,
4350 &osb->blocked_lock_list);
4351 osb->blocked_lock_count++;
4352 }
4353 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4354}
4355
4356static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
4357{
4358 unsigned long processed;
4359 unsigned long flags;
4360 struct ocfs2_lock_res *lockres;
4361
4362 spin_lock_irqsave(&osb->dc_task_lock, flags);
4363 /* grab this early so we know to try again if a state change and
4364 * wake happens part-way through our work */
4365 osb->dc_work_sequence = osb->dc_wake_sequence;
4366
4367 processed = osb->blocked_lock_count;
4368 /*
4369 * blocked lock processing in this loop might call iput which can
4370 * remove items off osb->blocked_lock_list. Downconvert up to
4371 * 'processed' number of locks, but stop short if we had some
4372 * removed in ocfs2_mark_lockres_freeing when downconverting.
4373 */
4374 while (processed && !list_empty(&osb->blocked_lock_list)) {
4375 lockres = list_entry(osb->blocked_lock_list.next,
4376 struct ocfs2_lock_res, l_blocked_list);
4377 list_del_init(&lockres->l_blocked_list);
4378 osb->blocked_lock_count--;
4379 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4380
4381 BUG_ON(!processed);
4382 processed--;
4383
4384 ocfs2_process_blocked_lock(osb, lockres);
4385
4386 spin_lock_irqsave(&osb->dc_task_lock, flags);
4387 }
4388 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4389}
4390
4391static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
4392{
4393 int empty = 0;
4394 unsigned long flags;
4395
4396 spin_lock_irqsave(&osb->dc_task_lock, flags);
4397 if (list_empty(&osb->blocked_lock_list))
4398 empty = 1;
4399
4400 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4401 return empty;
4402}
4403
4404static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
4405{
4406 int should_wake = 0;
4407 unsigned long flags;
4408
4409 spin_lock_irqsave(&osb->dc_task_lock, flags);
4410 if (osb->dc_work_sequence != osb->dc_wake_sequence)
4411 should_wake = 1;
4412 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4413
4414 return should_wake;
4415}
4416
4417static int ocfs2_downconvert_thread(void *arg)
4418{
4419 struct ocfs2_super *osb = arg;
4420
4421 /* only quit once we've been asked to stop and there is no more
4422 * work available */
4423 while (!(kthread_should_stop() &&
4424 ocfs2_downconvert_thread_lists_empty(osb))) {
4425
4426 wait_event_interruptible(osb->dc_event,
4427 ocfs2_downconvert_thread_should_wake(osb) ||
4428 kthread_should_stop());
4429
4430 mlog(0, "downconvert_thread: awoken\n");
4431
4432 ocfs2_downconvert_thread_do_work(osb);
4433 }
4434
4435 osb->dc_task = NULL;
4436 return 0;
4437}
4438
4439void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
4440{
4441 unsigned long flags;
4442
4443 spin_lock_irqsave(&osb->dc_task_lock, flags);
4444 /* make sure the voting thread gets a swipe at whatever changes
4445 * the caller may have made to the voting state */
4446 osb->dc_wake_sequence++;
4447 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4448 wake_up(&osb->dc_event);
4449}