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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/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmglue.c
5 *
6 * Code which implements an OCFS2 specific interface to our DLM.
7 *
8 * Copyright (C) 2003, 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26#include <linux/types.h>
27#include <linux/slab.h>
28#include <linux/highmem.h>
29#include <linux/mm.h>
30#include <linux/kthread.h>
31#include <linux/pagemap.h>
32#include <linux/debugfs.h>
33#include <linux/seq_file.h>
34#include <linux/time.h>
35#include <linux/quotaops.h>
36#include <linux/sched/signal.h>
37
38#define MLOG_MASK_PREFIX ML_DLM_GLUE
39#include <cluster/masklog.h>
40
41#include "ocfs2.h"
42#include "ocfs2_lockingver.h"
43
44#include "alloc.h"
45#include "dcache.h"
46#include "dlmglue.h"
47#include "extent_map.h"
48#include "file.h"
49#include "heartbeat.h"
50#include "inode.h"
51#include "journal.h"
52#include "stackglue.h"
53#include "slot_map.h"
54#include "super.h"
55#include "uptodate.h"
56#include "quota.h"
57#include "refcounttree.h"
58#include "acl.h"
59
60#include "buffer_head_io.h"
61
62struct ocfs2_mask_waiter {
63 struct list_head mw_item;
64 int mw_status;
65 struct completion mw_complete;
66 unsigned long mw_mask;
67 unsigned long mw_goal;
68#ifdef CONFIG_OCFS2_FS_STATS
69 ktime_t mw_lock_start;
70#endif
71};
72
73static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
74static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
75static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
76static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
77
78/*
79 * Return value from ->downconvert_worker functions.
80 *
81 * These control the precise actions of ocfs2_unblock_lock()
82 * and ocfs2_process_blocked_lock()
83 *
84 */
85enum ocfs2_unblock_action {
86 UNBLOCK_CONTINUE = 0, /* Continue downconvert */
87 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire
88 * ->post_unlock callback */
89 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire
90 * ->post_unlock() callback. */
91};
92
93struct ocfs2_unblock_ctl {
94 int requeue;
95 enum ocfs2_unblock_action unblock_action;
96};
97
98/* Lockdep class keys */
99struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
100
101static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
102 int new_level);
103static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
104
105static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
106 int blocking);
107
108static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
109 int blocking);
110
111static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
112 struct ocfs2_lock_res *lockres);
113
114static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
115
116static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
117 int new_level);
118static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
119 int blocking);
120
121#define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
122
123/* This aids in debugging situations where a bad LVB might be involved. */
124static void ocfs2_dump_meta_lvb_info(u64 level,
125 const char *function,
126 unsigned int line,
127 struct ocfs2_lock_res *lockres)
128{
129 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
130
131 mlog(level, "LVB information for %s (called from %s:%u):\n",
132 lockres->l_name, function, line);
133 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n",
134 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters),
135 be32_to_cpu(lvb->lvb_igeneration));
136 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
137 (unsigned long long)be64_to_cpu(lvb->lvb_isize),
138 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
139 be16_to_cpu(lvb->lvb_imode));
140 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
141 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
142 (long long)be64_to_cpu(lvb->lvb_iatime_packed),
143 (long long)be64_to_cpu(lvb->lvb_ictime_packed),
144 (long long)be64_to_cpu(lvb->lvb_imtime_packed),
145 be32_to_cpu(lvb->lvb_iattr));
146}
147
148
149/*
150 * OCFS2 Lock Resource Operations
151 *
152 * These fine tune the behavior of the generic dlmglue locking infrastructure.
153 *
154 * The most basic of lock types can point ->l_priv to their respective
155 * struct ocfs2_super and allow the default actions to manage things.
156 *
157 * Right now, each lock type also needs to implement an init function,
158 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
159 * should be called when the lock is no longer needed (i.e., object
160 * destruction time).
161 */
162struct ocfs2_lock_res_ops {
163 /*
164 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
165 * this callback if ->l_priv is not an ocfs2_super pointer
166 */
167 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
168
169 /*
170 * Optionally called in the downconvert thread after a
171 * successful downconvert. The lockres will not be referenced
172 * after this callback is called, so it is safe to free
173 * memory, etc.
174 *
175 * The exact semantics of when this is called are controlled
176 * by ->downconvert_worker()
177 */
178 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
179
180 /*
181 * Allow a lock type to add checks to determine whether it is
182 * safe to downconvert a lock. Return 0 to re-queue the
183 * downconvert at a later time, nonzero to continue.
184 *
185 * For most locks, the default checks that there are no
186 * incompatible holders are sufficient.
187 *
188 * Called with the lockres spinlock held.
189 */
190 int (*check_downconvert)(struct ocfs2_lock_res *, int);
191
192 /*
193 * Allows a lock type to populate the lock value block. This
194 * is called on downconvert, and when we drop a lock.
195 *
196 * Locks that want to use this should set LOCK_TYPE_USES_LVB
197 * in the flags field.
198 *
199 * Called with the lockres spinlock held.
200 */
201 void (*set_lvb)(struct ocfs2_lock_res *);
202
203 /*
204 * Called from the downconvert thread when it is determined
205 * that a lock will be downconverted. This is called without
206 * any locks held so the function can do work that might
207 * schedule (syncing out data, etc).
208 *
209 * This should return any one of the ocfs2_unblock_action
210 * values, depending on what it wants the thread to do.
211 */
212 int (*downconvert_worker)(struct ocfs2_lock_res *, int);
213
214 /*
215 * LOCK_TYPE_* flags which describe the specific requirements
216 * of a lock type. Descriptions of each individual flag follow.
217 */
218 int flags;
219};
220
221/*
222 * Some locks want to "refresh" potentially stale data when a
223 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this
224 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the
225 * individual lockres l_flags member from the ast function. It is
226 * expected that the locking wrapper will clear the
227 * OCFS2_LOCK_NEEDS_REFRESH flag when done.
228 */
229#define LOCK_TYPE_REQUIRES_REFRESH 0x1
230
231/*
232 * Indicate that a lock type makes use of the lock value block. The
233 * ->set_lvb lock type callback must be defined.
234 */
235#define LOCK_TYPE_USES_LVB 0x2
236
237static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
238 .get_osb = ocfs2_get_inode_osb,
239 .flags = 0,
240};
241
242static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
243 .get_osb = ocfs2_get_inode_osb,
244 .check_downconvert = ocfs2_check_meta_downconvert,
245 .set_lvb = ocfs2_set_meta_lvb,
246 .downconvert_worker = ocfs2_data_convert_worker,
247 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
248};
249
250static struct ocfs2_lock_res_ops ocfs2_super_lops = {
251 .flags = LOCK_TYPE_REQUIRES_REFRESH,
252};
253
254static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
255 .flags = 0,
256};
257
258static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
259 .flags = 0,
260};
261
262static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
263 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
264};
265
266static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
267 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
268};
269
270static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
271 .get_osb = ocfs2_get_dentry_osb,
272 .post_unlock = ocfs2_dentry_post_unlock,
273 .downconvert_worker = ocfs2_dentry_convert_worker,
274 .flags = 0,
275};
276
277static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
278 .get_osb = ocfs2_get_inode_osb,
279 .flags = 0,
280};
281
282static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
283 .get_osb = ocfs2_get_file_osb,
284 .flags = 0,
285};
286
287static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
288 .set_lvb = ocfs2_set_qinfo_lvb,
289 .get_osb = ocfs2_get_qinfo_osb,
290 .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
291};
292
293static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
294 .check_downconvert = ocfs2_check_refcount_downconvert,
295 .downconvert_worker = ocfs2_refcount_convert_worker,
296 .flags = 0,
297};
298
299static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
300{
301 return lockres->l_type == OCFS2_LOCK_TYPE_META ||
302 lockres->l_type == OCFS2_LOCK_TYPE_RW ||
303 lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
304}
305
306static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb)
307{
308 return container_of(lksb, struct ocfs2_lock_res, l_lksb);
309}
310
311static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
312{
313 BUG_ON(!ocfs2_is_inode_lock(lockres));
314
315 return (struct inode *) lockres->l_priv;
316}
317
318static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
319{
320 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
321
322 return (struct ocfs2_dentry_lock *)lockres->l_priv;
323}
324
325static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
326{
327 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
328
329 return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
330}
331
332static inline struct ocfs2_refcount_tree *
333ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res)
334{
335 return container_of(res, struct ocfs2_refcount_tree, rf_lockres);
336}
337
338static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
339{
340 if (lockres->l_ops->get_osb)
341 return lockres->l_ops->get_osb(lockres);
342
343 return (struct ocfs2_super *)lockres->l_priv;
344}
345
346static int ocfs2_lock_create(struct ocfs2_super *osb,
347 struct ocfs2_lock_res *lockres,
348 int level,
349 u32 dlm_flags);
350static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
351 int wanted);
352static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
353 struct ocfs2_lock_res *lockres,
354 int level, unsigned long caller_ip);
355static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb,
356 struct ocfs2_lock_res *lockres,
357 int level)
358{
359 __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_);
360}
361
362static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
363static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
364static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
365static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
366static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
367 struct ocfs2_lock_res *lockres);
368static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
369 int convert);
370#define ocfs2_log_dlm_error(_func, _err, _lockres) do { \
371 if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \
372 mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \
373 _err, _func, _lockres->l_name); \
374 else \
375 mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \
376 _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \
377 (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \
378} while (0)
379static int ocfs2_downconvert_thread(void *arg);
380static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
381 struct ocfs2_lock_res *lockres);
382static int ocfs2_inode_lock_update(struct inode *inode,
383 struct buffer_head **bh);
384static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
385static inline int ocfs2_highest_compat_lock_level(int level);
386static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
387 int new_level);
388static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
389 struct ocfs2_lock_res *lockres,
390 int new_level,
391 int lvb,
392 unsigned int generation);
393static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
394 struct ocfs2_lock_res *lockres);
395static int ocfs2_cancel_convert(struct ocfs2_super *osb,
396 struct ocfs2_lock_res *lockres);
397
398
399static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
400 u64 blkno,
401 u32 generation,
402 char *name)
403{
404 int len;
405
406 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
407
408 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
409 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
410 (long long)blkno, generation);
411
412 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
413
414 mlog(0, "built lock resource with name: %s\n", name);
415}
416
417static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
418
419static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
420 struct ocfs2_dlm_debug *dlm_debug)
421{
422 mlog(0, "Add tracking for lockres %s\n", res->l_name);
423
424 spin_lock(&ocfs2_dlm_tracking_lock);
425 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
426 spin_unlock(&ocfs2_dlm_tracking_lock);
427}
428
429static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
430{
431 spin_lock(&ocfs2_dlm_tracking_lock);
432 if (!list_empty(&res->l_debug_list))
433 list_del_init(&res->l_debug_list);
434 spin_unlock(&ocfs2_dlm_tracking_lock);
435}
436
437#ifdef CONFIG_OCFS2_FS_STATS
438static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
439{
440 res->l_lock_refresh = 0;
441 memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats));
442 memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats));
443}
444
445static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level,
446 struct ocfs2_mask_waiter *mw, int ret)
447{
448 u32 usec;
449 ktime_t kt;
450 struct ocfs2_lock_stats *stats;
451
452 if (level == LKM_PRMODE)
453 stats = &res->l_lock_prmode;
454 else if (level == LKM_EXMODE)
455 stats = &res->l_lock_exmode;
456 else
457 return;
458
459 kt = ktime_sub(ktime_get(), mw->mw_lock_start);
460 usec = ktime_to_us(kt);
461
462 stats->ls_gets++;
463 stats->ls_total += ktime_to_ns(kt);
464 /* overflow */
465 if (unlikely(stats->ls_gets == 0)) {
466 stats->ls_gets++;
467 stats->ls_total = ktime_to_ns(kt);
468 }
469
470 if (stats->ls_max < usec)
471 stats->ls_max = usec;
472
473 if (ret)
474 stats->ls_fail++;
475}
476
477static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
478{
479 lockres->l_lock_refresh++;
480}
481
482static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
483{
484 mw->mw_lock_start = ktime_get();
485}
486#else
487static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
488{
489}
490static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res,
491 int level, struct ocfs2_mask_waiter *mw, int ret)
492{
493}
494static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
495{
496}
497static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
498{
499}
500#endif
501
502static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
503 struct ocfs2_lock_res *res,
504 enum ocfs2_lock_type type,
505 struct ocfs2_lock_res_ops *ops,
506 void *priv)
507{
508 res->l_type = type;
509 res->l_ops = ops;
510 res->l_priv = priv;
511
512 res->l_level = DLM_LOCK_IV;
513 res->l_requested = DLM_LOCK_IV;
514 res->l_blocking = DLM_LOCK_IV;
515 res->l_action = OCFS2_AST_INVALID;
516 res->l_unlock_action = OCFS2_UNLOCK_INVALID;
517
518 res->l_flags = OCFS2_LOCK_INITIALIZED;
519
520 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
521
522 ocfs2_init_lock_stats(res);
523#ifdef CONFIG_DEBUG_LOCK_ALLOC
524 if (type != OCFS2_LOCK_TYPE_OPEN)
525 lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type],
526 &lockdep_keys[type], 0);
527 else
528 res->l_lockdep_map.key = NULL;
529#endif
530}
531
532void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
533{
534 /* This also clears out the lock status block */
535 memset(res, 0, sizeof(struct ocfs2_lock_res));
536 spin_lock_init(&res->l_lock);
537 init_waitqueue_head(&res->l_event);
538 INIT_LIST_HEAD(&res->l_blocked_list);
539 INIT_LIST_HEAD(&res->l_mask_waiters);
540 INIT_LIST_HEAD(&res->l_holders);
541}
542
543void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
544 enum ocfs2_lock_type type,
545 unsigned int generation,
546 struct inode *inode)
547{
548 struct ocfs2_lock_res_ops *ops;
549
550 switch(type) {
551 case OCFS2_LOCK_TYPE_RW:
552 ops = &ocfs2_inode_rw_lops;
553 break;
554 case OCFS2_LOCK_TYPE_META:
555 ops = &ocfs2_inode_inode_lops;
556 break;
557 case OCFS2_LOCK_TYPE_OPEN:
558 ops = &ocfs2_inode_open_lops;
559 break;
560 default:
561 mlog_bug_on_msg(1, "type: %d\n", type);
562 ops = NULL; /* thanks, gcc */
563 break;
564 };
565
566 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
567 generation, res->l_name);
568 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
569}
570
571static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
572{
573 struct inode *inode = ocfs2_lock_res_inode(lockres);
574
575 return OCFS2_SB(inode->i_sb);
576}
577
578static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
579{
580 struct ocfs2_mem_dqinfo *info = lockres->l_priv;
581
582 return OCFS2_SB(info->dqi_gi.dqi_sb);
583}
584
585static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
586{
587 struct ocfs2_file_private *fp = lockres->l_priv;
588
589 return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
590}
591
592static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
593{
594 __be64 inode_blkno_be;
595
596 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
597 sizeof(__be64));
598
599 return be64_to_cpu(inode_blkno_be);
600}
601
602static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
603{
604 struct ocfs2_dentry_lock *dl = lockres->l_priv;
605
606 return OCFS2_SB(dl->dl_inode->i_sb);
607}
608
609void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
610 u64 parent, struct inode *inode)
611{
612 int len;
613 u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
614 __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
615 struct ocfs2_lock_res *lockres = &dl->dl_lockres;
616
617 ocfs2_lock_res_init_once(lockres);
618
619 /*
620 * Unfortunately, the standard lock naming scheme won't work
621 * here because we have two 16 byte values to use. Instead,
622 * we'll stuff the inode number as a binary value. We still
623 * want error prints to show something without garbling the
624 * display, so drop a null byte in there before the inode
625 * number. A future version of OCFS2 will likely use all
626 * binary lock names. The stringified names have been a
627 * tremendous aid in debugging, but now that the debugfs
628 * interface exists, we can mangle things there if need be.
629 *
630 * NOTE: We also drop the standard "pad" value (the total lock
631 * name size stays the same though - the last part is all
632 * zeros due to the memset in ocfs2_lock_res_init_once()
633 */
634 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
635 "%c%016llx",
636 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
637 (long long)parent);
638
639 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
640
641 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
642 sizeof(__be64));
643
644 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
645 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
646 dl);
647}
648
649static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
650 struct ocfs2_super *osb)
651{
652 /* Superblock lockres doesn't come from a slab so we call init
653 * once on it manually. */
654 ocfs2_lock_res_init_once(res);
655 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
656 0, res->l_name);
657 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
658 &ocfs2_super_lops, osb);
659}
660
661static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
662 struct ocfs2_super *osb)
663{
664 /* Rename lockres doesn't come from a slab so we call init
665 * once on it manually. */
666 ocfs2_lock_res_init_once(res);
667 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
668 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
669 &ocfs2_rename_lops, osb);
670}
671
672static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
673 struct ocfs2_super *osb)
674{
675 /* nfs_sync lockres doesn't come from a slab so we call init
676 * once on it manually. */
677 ocfs2_lock_res_init_once(res);
678 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
679 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
680 &ocfs2_nfs_sync_lops, osb);
681}
682
683void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb)
684{
685 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
686
687 ocfs2_lock_res_init_once(lockres);
688 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name);
689 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS,
690 &ocfs2_trim_fs_lops, osb);
691}
692
693void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb)
694{
695 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
696
697 ocfs2_simple_drop_lockres(osb, lockres);
698 ocfs2_lock_res_free(lockres);
699}
700
701static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
702 struct ocfs2_super *osb)
703{
704 ocfs2_lock_res_init_once(res);
705 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
706 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
707 &ocfs2_orphan_scan_lops, osb);
708}
709
710void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
711 struct ocfs2_file_private *fp)
712{
713 struct inode *inode = fp->fp_file->f_mapping->host;
714 struct ocfs2_inode_info *oi = OCFS2_I(inode);
715
716 ocfs2_lock_res_init_once(lockres);
717 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
718 inode->i_generation, lockres->l_name);
719 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
720 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
721 fp);
722 lockres->l_flags |= OCFS2_LOCK_NOCACHE;
723}
724
725void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
726 struct ocfs2_mem_dqinfo *info)
727{
728 ocfs2_lock_res_init_once(lockres);
729 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
730 0, lockres->l_name);
731 ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
732 OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
733 info);
734}
735
736void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
737 struct ocfs2_super *osb, u64 ref_blkno,
738 unsigned int generation)
739{
740 ocfs2_lock_res_init_once(lockres);
741 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno,
742 generation, lockres->l_name);
743 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT,
744 &ocfs2_refcount_block_lops, osb);
745}
746
747void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
748{
749 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
750 return;
751
752 ocfs2_remove_lockres_tracking(res);
753
754 mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
755 "Lockres %s is on the blocked list\n",
756 res->l_name);
757 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
758 "Lockres %s has mask waiters pending\n",
759 res->l_name);
760 mlog_bug_on_msg(spin_is_locked(&res->l_lock),
761 "Lockres %s is locked\n",
762 res->l_name);
763 mlog_bug_on_msg(res->l_ro_holders,
764 "Lockres %s has %u ro holders\n",
765 res->l_name, res->l_ro_holders);
766 mlog_bug_on_msg(res->l_ex_holders,
767 "Lockres %s has %u ex holders\n",
768 res->l_name, res->l_ex_holders);
769
770 /* Need to clear out the lock status block for the dlm */
771 memset(&res->l_lksb, 0, sizeof(res->l_lksb));
772
773 res->l_flags = 0UL;
774}
775
776/*
777 * Keep a list of processes who have interest in a lockres.
778 * Note: this is now only uesed for check recursive cluster locking.
779 */
780static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres,
781 struct ocfs2_lock_holder *oh)
782{
783 INIT_LIST_HEAD(&oh->oh_list);
784 oh->oh_owner_pid = get_pid(task_pid(current));
785
786 spin_lock(&lockres->l_lock);
787 list_add_tail(&oh->oh_list, &lockres->l_holders);
788 spin_unlock(&lockres->l_lock);
789}
790
791static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres,
792 struct ocfs2_lock_holder *oh)
793{
794 spin_lock(&lockres->l_lock);
795 list_del(&oh->oh_list);
796 spin_unlock(&lockres->l_lock);
797
798 put_pid(oh->oh_owner_pid);
799}
800
801static inline int ocfs2_is_locked_by_me(struct ocfs2_lock_res *lockres)
802{
803 struct ocfs2_lock_holder *oh;
804 struct pid *pid;
805
806 /* look in the list of holders for one with the current task as owner */
807 spin_lock(&lockres->l_lock);
808 pid = task_pid(current);
809 list_for_each_entry(oh, &lockres->l_holders, oh_list) {
810 if (oh->oh_owner_pid == pid) {
811 spin_unlock(&lockres->l_lock);
812 return 1;
813 }
814 }
815 spin_unlock(&lockres->l_lock);
816
817 return 0;
818}
819
820static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
821 int level)
822{
823 BUG_ON(!lockres);
824
825 switch(level) {
826 case DLM_LOCK_EX:
827 lockres->l_ex_holders++;
828 break;
829 case DLM_LOCK_PR:
830 lockres->l_ro_holders++;
831 break;
832 default:
833 BUG();
834 }
835}
836
837static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
838 int level)
839{
840 BUG_ON(!lockres);
841
842 switch(level) {
843 case DLM_LOCK_EX:
844 BUG_ON(!lockres->l_ex_holders);
845 lockres->l_ex_holders--;
846 break;
847 case DLM_LOCK_PR:
848 BUG_ON(!lockres->l_ro_holders);
849 lockres->l_ro_holders--;
850 break;
851 default:
852 BUG();
853 }
854}
855
856/* WARNING: This function lives in a world where the only three lock
857 * levels are EX, PR, and NL. It *will* have to be adjusted when more
858 * lock types are added. */
859static inline int ocfs2_highest_compat_lock_level(int level)
860{
861 int new_level = DLM_LOCK_EX;
862
863 if (level == DLM_LOCK_EX)
864 new_level = DLM_LOCK_NL;
865 else if (level == DLM_LOCK_PR)
866 new_level = DLM_LOCK_PR;
867 return new_level;
868}
869
870static void lockres_set_flags(struct ocfs2_lock_res *lockres,
871 unsigned long newflags)
872{
873 struct ocfs2_mask_waiter *mw, *tmp;
874
875 assert_spin_locked(&lockres->l_lock);
876
877 lockres->l_flags = newflags;
878
879 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
880 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
881 continue;
882
883 list_del_init(&mw->mw_item);
884 mw->mw_status = 0;
885 complete(&mw->mw_complete);
886 }
887}
888static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
889{
890 lockres_set_flags(lockres, lockres->l_flags | or);
891}
892static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
893 unsigned long clear)
894{
895 lockres_set_flags(lockres, lockres->l_flags & ~clear);
896}
897
898static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
899{
900 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
901 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
902 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
903 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
904
905 lockres->l_level = lockres->l_requested;
906 if (lockres->l_level <=
907 ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
908 lockres->l_blocking = DLM_LOCK_NL;
909 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
910 }
911 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
912}
913
914static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
915{
916 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
917 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
918
919 /* Convert from RO to EX doesn't really need anything as our
920 * information is already up to data. Convert from NL to
921 * *anything* however should mark ourselves as needing an
922 * update */
923 if (lockres->l_level == DLM_LOCK_NL &&
924 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
925 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
926
927 lockres->l_level = lockres->l_requested;
928
929 /*
930 * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing
931 * the OCFS2_LOCK_BUSY flag to prevent the dc thread from
932 * downconverting the lock before the upconvert has fully completed.
933 * Do not prevent the dc thread from downconverting if NONBLOCK lock
934 * had already returned.
935 */
936 if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED))
937 lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
938 else
939 lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED);
940
941 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
942}
943
944static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
945{
946 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
947 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
948
949 if (lockres->l_requested > DLM_LOCK_NL &&
950 !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
951 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
952 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
953
954 lockres->l_level = lockres->l_requested;
955 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
956 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
957}
958
959static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
960 int level)
961{
962 int needs_downconvert = 0;
963
964 assert_spin_locked(&lockres->l_lock);
965
966 if (level > lockres->l_blocking) {
967 /* only schedule a downconvert if we haven't already scheduled
968 * one that goes low enough to satisfy the level we're
969 * blocking. this also catches the case where we get
970 * duplicate BASTs */
971 if (ocfs2_highest_compat_lock_level(level) <
972 ocfs2_highest_compat_lock_level(lockres->l_blocking))
973 needs_downconvert = 1;
974
975 lockres->l_blocking = level;
976 }
977
978 mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
979 lockres->l_name, level, lockres->l_level, lockres->l_blocking,
980 needs_downconvert);
981
982 if (needs_downconvert)
983 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
984 mlog(0, "needs_downconvert = %d\n", needs_downconvert);
985 return needs_downconvert;
986}
987
988/*
989 * OCFS2_LOCK_PENDING and l_pending_gen.
990 *
991 * Why does OCFS2_LOCK_PENDING exist? To close a race between setting
992 * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock()
993 * for more details on the race.
994 *
995 * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces
996 * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock()
997 * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear
998 * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns,
999 * the caller is going to try to clear PENDING again. If nothing else is
1000 * happening, __lockres_clear_pending() sees PENDING is unset and does
1001 * nothing.
1002 *
1003 * But what if another path (eg downconvert thread) has just started a
1004 * new locking action? The other path has re-set PENDING. Our path
1005 * cannot clear PENDING, because that will re-open the original race
1006 * window.
1007 *
1008 * [Example]
1009 *
1010 * ocfs2_meta_lock()
1011 * ocfs2_cluster_lock()
1012 * set BUSY
1013 * set PENDING
1014 * drop l_lock
1015 * ocfs2_dlm_lock()
1016 * ocfs2_locking_ast() ocfs2_downconvert_thread()
1017 * clear PENDING ocfs2_unblock_lock()
1018 * take_l_lock
1019 * !BUSY
1020 * ocfs2_prepare_downconvert()
1021 * set BUSY
1022 * set PENDING
1023 * drop l_lock
1024 * take l_lock
1025 * clear PENDING
1026 * drop l_lock
1027 * <window>
1028 * ocfs2_dlm_lock()
1029 *
1030 * So as you can see, we now have a window where l_lock is not held,
1031 * PENDING is not set, and ocfs2_dlm_lock() has not been called.
1032 *
1033 * The core problem is that ocfs2_cluster_lock() has cleared the PENDING
1034 * set by ocfs2_prepare_downconvert(). That wasn't nice.
1035 *
1036 * To solve this we introduce l_pending_gen. A call to
1037 * lockres_clear_pending() will only do so when it is passed a generation
1038 * number that matches the lockres. lockres_set_pending() will return the
1039 * current generation number. When ocfs2_cluster_lock() goes to clear
1040 * PENDING, it passes the generation it got from set_pending(). In our
1041 * example above, the generation numbers will *not* match. Thus,
1042 * ocfs2_cluster_lock() will not clear the PENDING set by
1043 * ocfs2_prepare_downconvert().
1044 */
1045
1046/* Unlocked version for ocfs2_locking_ast() */
1047static void __lockres_clear_pending(struct ocfs2_lock_res *lockres,
1048 unsigned int generation,
1049 struct ocfs2_super *osb)
1050{
1051 assert_spin_locked(&lockres->l_lock);
1052
1053 /*
1054 * The ast and locking functions can race us here. The winner
1055 * will clear pending, the loser will not.
1056 */
1057 if (!(lockres->l_flags & OCFS2_LOCK_PENDING) ||
1058 (lockres->l_pending_gen != generation))
1059 return;
1060
1061 lockres_clear_flags(lockres, OCFS2_LOCK_PENDING);
1062 lockres->l_pending_gen++;
1063
1064 /*
1065 * The downconvert thread may have skipped us because we
1066 * were PENDING. Wake it up.
1067 */
1068 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1069 ocfs2_wake_downconvert_thread(osb);
1070}
1071
1072/* Locked version for callers of ocfs2_dlm_lock() */
1073static void lockres_clear_pending(struct ocfs2_lock_res *lockres,
1074 unsigned int generation,
1075 struct ocfs2_super *osb)
1076{
1077 unsigned long flags;
1078
1079 spin_lock_irqsave(&lockres->l_lock, flags);
1080 __lockres_clear_pending(lockres, generation, osb);
1081 spin_unlock_irqrestore(&lockres->l_lock, flags);
1082}
1083
1084static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
1085{
1086 assert_spin_locked(&lockres->l_lock);
1087 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
1088
1089 lockres_or_flags(lockres, OCFS2_LOCK_PENDING);
1090
1091 return lockres->l_pending_gen;
1092}
1093
1094static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
1095{
1096 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1097 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1098 int needs_downconvert;
1099 unsigned long flags;
1100
1101 BUG_ON(level <= DLM_LOCK_NL);
1102
1103 mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
1104 "type %s\n", lockres->l_name, level, lockres->l_level,
1105 ocfs2_lock_type_string(lockres->l_type));
1106
1107 /*
1108 * We can skip the bast for locks which don't enable caching -
1109 * they'll be dropped at the earliest possible time anyway.
1110 */
1111 if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
1112 return;
1113
1114 spin_lock_irqsave(&lockres->l_lock, flags);
1115 needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
1116 if (needs_downconvert)
1117 ocfs2_schedule_blocked_lock(osb, lockres);
1118 spin_unlock_irqrestore(&lockres->l_lock, flags);
1119
1120 wake_up(&lockres->l_event);
1121
1122 ocfs2_wake_downconvert_thread(osb);
1123}
1124
1125static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
1126{
1127 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1128 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1129 unsigned long flags;
1130 int status;
1131
1132 spin_lock_irqsave(&lockres->l_lock, flags);
1133
1134 status = ocfs2_dlm_lock_status(&lockres->l_lksb);
1135
1136 if (status == -EAGAIN) {
1137 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1138 goto out;
1139 }
1140
1141 if (status) {
1142 mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n",
1143 lockres->l_name, status);
1144 spin_unlock_irqrestore(&lockres->l_lock, flags);
1145 return;
1146 }
1147
1148 mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
1149 "level %d => %d\n", lockres->l_name, lockres->l_action,
1150 lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
1151
1152 switch(lockres->l_action) {
1153 case OCFS2_AST_ATTACH:
1154 ocfs2_generic_handle_attach_action(lockres);
1155 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
1156 break;
1157 case OCFS2_AST_CONVERT:
1158 ocfs2_generic_handle_convert_action(lockres);
1159 break;
1160 case OCFS2_AST_DOWNCONVERT:
1161 ocfs2_generic_handle_downconvert_action(lockres);
1162 break;
1163 default:
1164 mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
1165 "flags 0x%lx, unlock: %u\n",
1166 lockres->l_name, lockres->l_action, lockres->l_flags,
1167 lockres->l_unlock_action);
1168 BUG();
1169 }
1170out:
1171 /* set it to something invalid so if we get called again we
1172 * can catch it. */
1173 lockres->l_action = OCFS2_AST_INVALID;
1174
1175 /* Did we try to cancel this lock? Clear that state */
1176 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT)
1177 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1178
1179 /*
1180 * We may have beaten the locking functions here. We certainly
1181 * know that dlm_lock() has been called :-)
1182 * Because we can't have two lock calls in flight at once, we
1183 * can use lockres->l_pending_gen.
1184 */
1185 __lockres_clear_pending(lockres, lockres->l_pending_gen, osb);
1186
1187 wake_up(&lockres->l_event);
1188 spin_unlock_irqrestore(&lockres->l_lock, flags);
1189}
1190
1191static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
1192{
1193 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1194 unsigned long flags;
1195
1196 mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
1197 lockres->l_name, lockres->l_unlock_action);
1198
1199 spin_lock_irqsave(&lockres->l_lock, flags);
1200 if (error) {
1201 mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
1202 "unlock_action %d\n", error, lockres->l_name,
1203 lockres->l_unlock_action);
1204 spin_unlock_irqrestore(&lockres->l_lock, flags);
1205 return;
1206 }
1207
1208 switch(lockres->l_unlock_action) {
1209 case OCFS2_UNLOCK_CANCEL_CONVERT:
1210 mlog(0, "Cancel convert success for %s\n", lockres->l_name);
1211 lockres->l_action = OCFS2_AST_INVALID;
1212 /* Downconvert thread may have requeued this lock, we
1213 * need to wake it. */
1214 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1215 ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
1216 break;
1217 case OCFS2_UNLOCK_DROP_LOCK:
1218 lockres->l_level = DLM_LOCK_IV;
1219 break;
1220 default:
1221 BUG();
1222 }
1223
1224 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1225 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1226 wake_up(&lockres->l_event);
1227 spin_unlock_irqrestore(&lockres->l_lock, flags);
1228}
1229
1230/*
1231 * This is the filesystem locking protocol. It provides the lock handling
1232 * hooks for the underlying DLM. It has a maximum version number.
1233 * The version number allows interoperability with systems running at
1234 * the same major number and an equal or smaller minor number.
1235 *
1236 * Whenever the filesystem does new things with locks (adds or removes a
1237 * lock, orders them differently, does different things underneath a lock),
1238 * the version must be changed. The protocol is negotiated when joining
1239 * the dlm domain. A node may join the domain if its major version is
1240 * identical to all other nodes and its minor version is greater than
1241 * or equal to all other nodes. When its minor version is greater than
1242 * the other nodes, it will run at the minor version specified by the
1243 * other nodes.
1244 *
1245 * If a locking change is made that will not be compatible with older
1246 * versions, the major number must be increased and the minor version set
1247 * to zero. If a change merely adds a behavior that can be disabled when
1248 * speaking to older versions, the minor version must be increased. If a
1249 * change adds a fully backwards compatible change (eg, LVB changes that
1250 * are just ignored by older versions), the version does not need to be
1251 * updated.
1252 */
1253static struct ocfs2_locking_protocol lproto = {
1254 .lp_max_version = {
1255 .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
1256 .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
1257 },
1258 .lp_lock_ast = ocfs2_locking_ast,
1259 .lp_blocking_ast = ocfs2_blocking_ast,
1260 .lp_unlock_ast = ocfs2_unlock_ast,
1261};
1262
1263void ocfs2_set_locking_protocol(void)
1264{
1265 ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
1266}
1267
1268static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
1269 int convert)
1270{
1271 unsigned long flags;
1272
1273 spin_lock_irqsave(&lockres->l_lock, flags);
1274 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1275 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1276 if (convert)
1277 lockres->l_action = OCFS2_AST_INVALID;
1278 else
1279 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1280 spin_unlock_irqrestore(&lockres->l_lock, flags);
1281
1282 wake_up(&lockres->l_event);
1283}
1284
1285/* Note: If we detect another process working on the lock (i.e.,
1286 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
1287 * to do the right thing in that case.
1288 */
1289static int ocfs2_lock_create(struct ocfs2_super *osb,
1290 struct ocfs2_lock_res *lockres,
1291 int level,
1292 u32 dlm_flags)
1293{
1294 int ret = 0;
1295 unsigned long flags;
1296 unsigned int gen;
1297
1298 mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level,
1299 dlm_flags);
1300
1301 spin_lock_irqsave(&lockres->l_lock, flags);
1302 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
1303 (lockres->l_flags & OCFS2_LOCK_BUSY)) {
1304 spin_unlock_irqrestore(&lockres->l_lock, flags);
1305 goto bail;
1306 }
1307
1308 lockres->l_action = OCFS2_AST_ATTACH;
1309 lockres->l_requested = level;
1310 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1311 gen = lockres_set_pending(lockres);
1312 spin_unlock_irqrestore(&lockres->l_lock, flags);
1313
1314 ret = ocfs2_dlm_lock(osb->cconn,
1315 level,
1316 &lockres->l_lksb,
1317 dlm_flags,
1318 lockres->l_name,
1319 OCFS2_LOCK_ID_MAX_LEN - 1);
1320 lockres_clear_pending(lockres, gen, osb);
1321 if (ret) {
1322 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
1323 ocfs2_recover_from_dlm_error(lockres, 1);
1324 }
1325
1326 mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name);
1327
1328bail:
1329 return ret;
1330}
1331
1332static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
1333 int flag)
1334{
1335 unsigned long flags;
1336 int ret;
1337
1338 spin_lock_irqsave(&lockres->l_lock, flags);
1339 ret = lockres->l_flags & flag;
1340 spin_unlock_irqrestore(&lockres->l_lock, flags);
1341
1342 return ret;
1343}
1344
1345static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
1346
1347{
1348 wait_event(lockres->l_event,
1349 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
1350}
1351
1352static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
1353
1354{
1355 wait_event(lockres->l_event,
1356 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
1357}
1358
1359/* predict what lock level we'll be dropping down to on behalf
1360 * of another node, and return true if the currently wanted
1361 * level will be compatible with it. */
1362static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
1363 int wanted)
1364{
1365 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
1366
1367 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
1368}
1369
1370static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
1371{
1372 INIT_LIST_HEAD(&mw->mw_item);
1373 init_completion(&mw->mw_complete);
1374 ocfs2_init_start_time(mw);
1375}
1376
1377static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
1378{
1379 wait_for_completion(&mw->mw_complete);
1380 /* Re-arm the completion in case we want to wait on it again */
1381 reinit_completion(&mw->mw_complete);
1382 return mw->mw_status;
1383}
1384
1385static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
1386 struct ocfs2_mask_waiter *mw,
1387 unsigned long mask,
1388 unsigned long goal)
1389{
1390 BUG_ON(!list_empty(&mw->mw_item));
1391
1392 assert_spin_locked(&lockres->l_lock);
1393
1394 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
1395 mw->mw_mask = mask;
1396 mw->mw_goal = goal;
1397}
1398
1399/* returns 0 if the mw that was removed was already satisfied, -EBUSY
1400 * if the mask still hadn't reached its goal */
1401static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1402 struct ocfs2_mask_waiter *mw)
1403{
1404 int ret = 0;
1405
1406 assert_spin_locked(&lockres->l_lock);
1407 if (!list_empty(&mw->mw_item)) {
1408 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
1409 ret = -EBUSY;
1410
1411 list_del_init(&mw->mw_item);
1412 init_completion(&mw->mw_complete);
1413 }
1414
1415 return ret;
1416}
1417
1418static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1419 struct ocfs2_mask_waiter *mw)
1420{
1421 unsigned long flags;
1422 int ret = 0;
1423
1424 spin_lock_irqsave(&lockres->l_lock, flags);
1425 ret = __lockres_remove_mask_waiter(lockres, mw);
1426 spin_unlock_irqrestore(&lockres->l_lock, flags);
1427
1428 return ret;
1429
1430}
1431
1432static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
1433 struct ocfs2_lock_res *lockres)
1434{
1435 int ret;
1436
1437 ret = wait_for_completion_interruptible(&mw->mw_complete);
1438 if (ret)
1439 lockres_remove_mask_waiter(lockres, mw);
1440 else
1441 ret = mw->mw_status;
1442 /* Re-arm the completion in case we want to wait on it again */
1443 reinit_completion(&mw->mw_complete);
1444 return ret;
1445}
1446
1447static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
1448 struct ocfs2_lock_res *lockres,
1449 int level,
1450 u32 lkm_flags,
1451 int arg_flags,
1452 int l_subclass,
1453 unsigned long caller_ip)
1454{
1455 struct ocfs2_mask_waiter mw;
1456 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
1457 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
1458 unsigned long flags;
1459 unsigned int gen;
1460 int noqueue_attempted = 0;
1461 int dlm_locked = 0;
1462 int kick_dc = 0;
1463
1464 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
1465 mlog_errno(-EINVAL);
1466 return -EINVAL;
1467 }
1468
1469 ocfs2_init_mask_waiter(&mw);
1470
1471 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
1472 lkm_flags |= DLM_LKF_VALBLK;
1473
1474again:
1475 wait = 0;
1476
1477 spin_lock_irqsave(&lockres->l_lock, flags);
1478
1479 if (catch_signals && signal_pending(current)) {
1480 ret = -ERESTARTSYS;
1481 goto unlock;
1482 }
1483
1484 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
1485 "Cluster lock called on freeing lockres %s! flags "
1486 "0x%lx\n", lockres->l_name, lockres->l_flags);
1487
1488 /* We only compare against the currently granted level
1489 * here. If the lock is blocked waiting on a downconvert,
1490 * we'll get caught below. */
1491 if (lockres->l_flags & OCFS2_LOCK_BUSY &&
1492 level > lockres->l_level) {
1493 /* is someone sitting in dlm_lock? If so, wait on
1494 * them. */
1495 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1496 wait = 1;
1497 goto unlock;
1498 }
1499
1500 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) {
1501 /*
1502 * We've upconverted. If the lock now has a level we can
1503 * work with, we take it. If, however, the lock is not at the
1504 * required level, we go thru the full cycle. One way this could
1505 * happen is if a process requesting an upconvert to PR is
1506 * closely followed by another requesting upconvert to an EX.
1507 * If the process requesting EX lands here, we want it to
1508 * continue attempting to upconvert and let the process
1509 * requesting PR take the lock.
1510 * If multiple processes request upconvert to PR, the first one
1511 * here will take the lock. The others will have to go thru the
1512 * OCFS2_LOCK_BLOCKED check to ensure that there is no pending
1513 * downconvert request.
1514 */
1515 if (level <= lockres->l_level)
1516 goto update_holders;
1517 }
1518
1519 if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
1520 !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
1521 /* is the lock is currently blocked on behalf of
1522 * another node */
1523 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
1524 wait = 1;
1525 goto unlock;
1526 }
1527
1528 if (level > lockres->l_level) {
1529 if (noqueue_attempted > 0) {
1530 ret = -EAGAIN;
1531 goto unlock;
1532 }
1533 if (lkm_flags & DLM_LKF_NOQUEUE)
1534 noqueue_attempted = 1;
1535
1536 if (lockres->l_action != OCFS2_AST_INVALID)
1537 mlog(ML_ERROR, "lockres %s has action %u pending\n",
1538 lockres->l_name, lockres->l_action);
1539
1540 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1541 lockres->l_action = OCFS2_AST_ATTACH;
1542 lkm_flags &= ~DLM_LKF_CONVERT;
1543 } else {
1544 lockres->l_action = OCFS2_AST_CONVERT;
1545 lkm_flags |= DLM_LKF_CONVERT;
1546 }
1547
1548 lockres->l_requested = level;
1549 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1550 gen = lockres_set_pending(lockres);
1551 spin_unlock_irqrestore(&lockres->l_lock, flags);
1552
1553 BUG_ON(level == DLM_LOCK_IV);
1554 BUG_ON(level == DLM_LOCK_NL);
1555
1556 mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
1557 lockres->l_name, lockres->l_level, level);
1558
1559 /* call dlm_lock to upgrade lock now */
1560 ret = ocfs2_dlm_lock(osb->cconn,
1561 level,
1562 &lockres->l_lksb,
1563 lkm_flags,
1564 lockres->l_name,
1565 OCFS2_LOCK_ID_MAX_LEN - 1);
1566 lockres_clear_pending(lockres, gen, osb);
1567 if (ret) {
1568 if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
1569 (ret != -EAGAIN)) {
1570 ocfs2_log_dlm_error("ocfs2_dlm_lock",
1571 ret, lockres);
1572 }
1573 ocfs2_recover_from_dlm_error(lockres, 1);
1574 goto out;
1575 }
1576 dlm_locked = 1;
1577
1578 mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n",
1579 lockres->l_name);
1580
1581 /* At this point we've gone inside the dlm and need to
1582 * complete our work regardless. */
1583 catch_signals = 0;
1584
1585 /* wait for busy to clear and carry on */
1586 goto again;
1587 }
1588
1589update_holders:
1590 /* Ok, if we get here then we're good to go. */
1591 ocfs2_inc_holders(lockres, level);
1592
1593 ret = 0;
1594unlock:
1595 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1596
1597 /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */
1598 kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED);
1599
1600 spin_unlock_irqrestore(&lockres->l_lock, flags);
1601 if (kick_dc)
1602 ocfs2_wake_downconvert_thread(osb);
1603out:
1604 /*
1605 * This is helping work around a lock inversion between the page lock
1606 * and dlm locks. One path holds the page lock while calling aops
1607 * which block acquiring dlm locks. The voting thread holds dlm
1608 * locks while acquiring page locks while down converting data locks.
1609 * This block is helping an aop path notice the inversion and back
1610 * off to unlock its page lock before trying the dlm lock again.
1611 */
1612 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
1613 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
1614 wait = 0;
1615 spin_lock_irqsave(&lockres->l_lock, flags);
1616 if (__lockres_remove_mask_waiter(lockres, &mw)) {
1617 if (dlm_locked)
1618 lockres_or_flags(lockres,
1619 OCFS2_LOCK_NONBLOCK_FINISHED);
1620 spin_unlock_irqrestore(&lockres->l_lock, flags);
1621 ret = -EAGAIN;
1622 } else {
1623 spin_unlock_irqrestore(&lockres->l_lock, flags);
1624 goto again;
1625 }
1626 }
1627 if (wait) {
1628 ret = ocfs2_wait_for_mask(&mw);
1629 if (ret == 0)
1630 goto again;
1631 mlog_errno(ret);
1632 }
1633 ocfs2_update_lock_stats(lockres, level, &mw, ret);
1634
1635#ifdef CONFIG_DEBUG_LOCK_ALLOC
1636 if (!ret && lockres->l_lockdep_map.key != NULL) {
1637 if (level == DLM_LOCK_PR)
1638 rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass,
1639 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1640 caller_ip);
1641 else
1642 rwsem_acquire(&lockres->l_lockdep_map, l_subclass,
1643 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1644 caller_ip);
1645 }
1646#endif
1647 return ret;
1648}
1649
1650static inline int ocfs2_cluster_lock(struct ocfs2_super *osb,
1651 struct ocfs2_lock_res *lockres,
1652 int level,
1653 u32 lkm_flags,
1654 int arg_flags)
1655{
1656 return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags,
1657 0, _RET_IP_);
1658}
1659
1660
1661static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
1662 struct ocfs2_lock_res *lockres,
1663 int level,
1664 unsigned long caller_ip)
1665{
1666 unsigned long flags;
1667
1668 spin_lock_irqsave(&lockres->l_lock, flags);
1669 ocfs2_dec_holders(lockres, level);
1670 ocfs2_downconvert_on_unlock(osb, lockres);
1671 spin_unlock_irqrestore(&lockres->l_lock, flags);
1672#ifdef CONFIG_DEBUG_LOCK_ALLOC
1673 if (lockres->l_lockdep_map.key != NULL)
1674 rwsem_release(&lockres->l_lockdep_map, 1, caller_ip);
1675#endif
1676}
1677
1678static int ocfs2_create_new_lock(struct ocfs2_super *osb,
1679 struct ocfs2_lock_res *lockres,
1680 int ex,
1681 int local)
1682{
1683 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1684 unsigned long flags;
1685 u32 lkm_flags = local ? DLM_LKF_LOCAL : 0;
1686
1687 spin_lock_irqsave(&lockres->l_lock, flags);
1688 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
1689 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
1690 spin_unlock_irqrestore(&lockres->l_lock, flags);
1691
1692 return ocfs2_lock_create(osb, lockres, level, lkm_flags);
1693}
1694
1695/* Grants us an EX lock on the data and metadata resources, skipping
1696 * the normal cluster directory lookup. Use this ONLY on newly created
1697 * inodes which other nodes can't possibly see, and which haven't been
1698 * hashed in the inode hash yet. This can give us a good performance
1699 * increase as it'll skip the network broadcast normally associated
1700 * with creating a new lock resource. */
1701int ocfs2_create_new_inode_locks(struct inode *inode)
1702{
1703 int ret;
1704 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1705
1706 BUG_ON(!ocfs2_inode_is_new(inode));
1707
1708 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
1709
1710 /* NOTE: That we don't increment any of the holder counts, nor
1711 * do we add anything to a journal handle. Since this is
1712 * supposed to be a new inode which the cluster doesn't know
1713 * about yet, there is no need to. As far as the LVB handling
1714 * is concerned, this is basically like acquiring an EX lock
1715 * on a resource which has an invalid one -- we'll set it
1716 * valid when we release the EX. */
1717
1718 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
1719 if (ret) {
1720 mlog_errno(ret);
1721 goto bail;
1722 }
1723
1724 /*
1725 * We don't want to use DLM_LKF_LOCAL on a meta data lock as they
1726 * don't use a generation in their lock names.
1727 */
1728 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
1729 if (ret) {
1730 mlog_errno(ret);
1731 goto bail;
1732 }
1733
1734 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
1735 if (ret)
1736 mlog_errno(ret);
1737
1738bail:
1739 return ret;
1740}
1741
1742int ocfs2_rw_lock(struct inode *inode, int write)
1743{
1744 int status, level;
1745 struct ocfs2_lock_res *lockres;
1746 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1747
1748 mlog(0, "inode %llu take %s RW lock\n",
1749 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1750 write ? "EXMODE" : "PRMODE");
1751
1752 if (ocfs2_mount_local(osb))
1753 return 0;
1754
1755 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1756
1757 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1758
1759 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
1760 if (status < 0)
1761 mlog_errno(status);
1762
1763 return status;
1764}
1765
1766int ocfs2_try_rw_lock(struct inode *inode, int write)
1767{
1768 int status, level;
1769 struct ocfs2_lock_res *lockres;
1770 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1771
1772 mlog(0, "inode %llu try to take %s RW lock\n",
1773 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1774 write ? "EXMODE" : "PRMODE");
1775
1776 if (ocfs2_mount_local(osb))
1777 return 0;
1778
1779 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1780
1781 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1782
1783 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0);
1784 return status;
1785}
1786
1787void ocfs2_rw_unlock(struct inode *inode, int write)
1788{
1789 int level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1790 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
1791 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1792
1793 mlog(0, "inode %llu drop %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 ocfs2_cluster_unlock(osb, lockres, level);
1799}
1800
1801/*
1802 * ocfs2_open_lock always get PR mode lock.
1803 */
1804int ocfs2_open_lock(struct inode *inode)
1805{
1806 int status = 0;
1807 struct ocfs2_lock_res *lockres;
1808 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1809
1810 mlog(0, "inode %llu take PRMODE open lock\n",
1811 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1812
1813 if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb))
1814 goto out;
1815
1816 lockres = &OCFS2_I(inode)->ip_open_lockres;
1817
1818 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_PR, 0, 0);
1819 if (status < 0)
1820 mlog_errno(status);
1821
1822out:
1823 return status;
1824}
1825
1826int ocfs2_try_open_lock(struct inode *inode, int write)
1827{
1828 int status = 0, level;
1829 struct ocfs2_lock_res *lockres;
1830 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1831
1832 mlog(0, "inode %llu try to take %s open lock\n",
1833 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1834 write ? "EXMODE" : "PRMODE");
1835
1836 if (ocfs2_is_hard_readonly(osb)) {
1837 if (write)
1838 status = -EROFS;
1839 goto out;
1840 }
1841
1842 if (ocfs2_mount_local(osb))
1843 goto out;
1844
1845 lockres = &OCFS2_I(inode)->ip_open_lockres;
1846
1847 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1848
1849 /*
1850 * The file system may already holding a PRMODE/EXMODE open lock.
1851 * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on
1852 * other nodes and the -EAGAIN will indicate to the caller that
1853 * this inode is still in use.
1854 */
1855 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0);
1856
1857out:
1858 return status;
1859}
1860
1861/*
1862 * ocfs2_open_unlock unlock PR and EX mode open locks.
1863 */
1864void ocfs2_open_unlock(struct inode *inode)
1865{
1866 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
1867 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1868
1869 mlog(0, "inode %llu drop open lock\n",
1870 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1871
1872 if (ocfs2_mount_local(osb))
1873 goto out;
1874
1875 if(lockres->l_ro_holders)
1876 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_PR);
1877 if(lockres->l_ex_holders)
1878 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
1879
1880out:
1881 return;
1882}
1883
1884static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
1885 int level)
1886{
1887 int ret;
1888 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1889 unsigned long flags;
1890 struct ocfs2_mask_waiter mw;
1891
1892 ocfs2_init_mask_waiter(&mw);
1893
1894retry_cancel:
1895 spin_lock_irqsave(&lockres->l_lock, flags);
1896 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
1897 ret = ocfs2_prepare_cancel_convert(osb, lockres);
1898 if (ret) {
1899 spin_unlock_irqrestore(&lockres->l_lock, flags);
1900 ret = ocfs2_cancel_convert(osb, lockres);
1901 if (ret < 0) {
1902 mlog_errno(ret);
1903 goto out;
1904 }
1905 goto retry_cancel;
1906 }
1907 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1908 spin_unlock_irqrestore(&lockres->l_lock, flags);
1909
1910 ocfs2_wait_for_mask(&mw);
1911 goto retry_cancel;
1912 }
1913
1914 ret = -ERESTARTSYS;
1915 /*
1916 * We may still have gotten the lock, in which case there's no
1917 * point to restarting the syscall.
1918 */
1919 if (lockres->l_level == level)
1920 ret = 0;
1921
1922 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
1923 lockres->l_flags, lockres->l_level, lockres->l_action);
1924
1925 spin_unlock_irqrestore(&lockres->l_lock, flags);
1926
1927out:
1928 return ret;
1929}
1930
1931/*
1932 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
1933 * flock() calls. The locking approach this requires is sufficiently
1934 * different from all other cluster lock types that we implement a
1935 * separate path to the "low-level" dlm calls. In particular:
1936 *
1937 * - No optimization of lock levels is done - we take at exactly
1938 * what's been requested.
1939 *
1940 * - No lock caching is employed. We immediately downconvert to
1941 * no-lock at unlock time. This also means flock locks never go on
1942 * the blocking list).
1943 *
1944 * - Since userspace can trivially deadlock itself with flock, we make
1945 * sure to allow cancellation of a misbehaving applications flock()
1946 * request.
1947 *
1948 * - Access to any flock lockres doesn't require concurrency, so we
1949 * can simplify the code by requiring the caller to guarantee
1950 * serialization of dlmglue flock calls.
1951 */
1952int ocfs2_file_lock(struct file *file, int ex, int trylock)
1953{
1954 int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1955 unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
1956 unsigned long flags;
1957 struct ocfs2_file_private *fp = file->private_data;
1958 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1959 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1960 struct ocfs2_mask_waiter mw;
1961
1962 ocfs2_init_mask_waiter(&mw);
1963
1964 if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
1965 (lockres->l_level > DLM_LOCK_NL)) {
1966 mlog(ML_ERROR,
1967 "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
1968 "level: %u\n", lockres->l_name, lockres->l_flags,
1969 lockres->l_level);
1970 return -EINVAL;
1971 }
1972
1973 spin_lock_irqsave(&lockres->l_lock, flags);
1974 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1975 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1976 spin_unlock_irqrestore(&lockres->l_lock, flags);
1977
1978 /*
1979 * Get the lock at NLMODE to start - that way we
1980 * can cancel the upconvert request if need be.
1981 */
1982 ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
1983 if (ret < 0) {
1984 mlog_errno(ret);
1985 goto out;
1986 }
1987
1988 ret = ocfs2_wait_for_mask(&mw);
1989 if (ret) {
1990 mlog_errno(ret);
1991 goto out;
1992 }
1993 spin_lock_irqsave(&lockres->l_lock, flags);
1994 }
1995
1996 lockres->l_action = OCFS2_AST_CONVERT;
1997 lkm_flags |= DLM_LKF_CONVERT;
1998 lockres->l_requested = level;
1999 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2000
2001 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
2002 spin_unlock_irqrestore(&lockres->l_lock, flags);
2003
2004 ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags,
2005 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1);
2006 if (ret) {
2007 if (!trylock || (ret != -EAGAIN)) {
2008 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
2009 ret = -EINVAL;
2010 }
2011
2012 ocfs2_recover_from_dlm_error(lockres, 1);
2013 lockres_remove_mask_waiter(lockres, &mw);
2014 goto out;
2015 }
2016
2017 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
2018 if (ret == -ERESTARTSYS) {
2019 /*
2020 * Userspace can cause deadlock itself with
2021 * flock(). Current behavior locally is to allow the
2022 * deadlock, but abort the system call if a signal is
2023 * received. We follow this example, otherwise a
2024 * poorly written program could sit in kernel until
2025 * reboot.
2026 *
2027 * Handling this is a bit more complicated for Ocfs2
2028 * though. We can't exit this function with an
2029 * outstanding lock request, so a cancel convert is
2030 * required. We intentionally overwrite 'ret' - if the
2031 * cancel fails and the lock was granted, it's easier
2032 * to just bubble success back up to the user.
2033 */
2034 ret = ocfs2_flock_handle_signal(lockres, level);
2035 } else if (!ret && (level > lockres->l_level)) {
2036 /* Trylock failed asynchronously */
2037 BUG_ON(!trylock);
2038 ret = -EAGAIN;
2039 }
2040
2041out:
2042
2043 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
2044 lockres->l_name, ex, trylock, ret);
2045 return ret;
2046}
2047
2048void ocfs2_file_unlock(struct file *file)
2049{
2050 int ret;
2051 unsigned int gen;
2052 unsigned long flags;
2053 struct ocfs2_file_private *fp = file->private_data;
2054 struct ocfs2_lock_res *lockres = &fp->fp_flock;
2055 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
2056 struct ocfs2_mask_waiter mw;
2057
2058 ocfs2_init_mask_waiter(&mw);
2059
2060 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
2061 return;
2062
2063 if (lockres->l_level == DLM_LOCK_NL)
2064 return;
2065
2066 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
2067 lockres->l_name, lockres->l_flags, lockres->l_level,
2068 lockres->l_action);
2069
2070 spin_lock_irqsave(&lockres->l_lock, flags);
2071 /*
2072 * Fake a blocking ast for the downconvert code.
2073 */
2074 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
2075 lockres->l_blocking = DLM_LOCK_EX;
2076
2077 gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
2078 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
2079 spin_unlock_irqrestore(&lockres->l_lock, flags);
2080
2081 ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
2082 if (ret) {
2083 mlog_errno(ret);
2084 return;
2085 }
2086
2087 ret = ocfs2_wait_for_mask(&mw);
2088 if (ret)
2089 mlog_errno(ret);
2090}
2091
2092static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
2093 struct ocfs2_lock_res *lockres)
2094{
2095 int kick = 0;
2096
2097 /* If we know that another node is waiting on our lock, kick
2098 * the downconvert thread * pre-emptively when we reach a release
2099 * condition. */
2100 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
2101 switch(lockres->l_blocking) {
2102 case DLM_LOCK_EX:
2103 if (!lockres->l_ex_holders && !lockres->l_ro_holders)
2104 kick = 1;
2105 break;
2106 case DLM_LOCK_PR:
2107 if (!lockres->l_ex_holders)
2108 kick = 1;
2109 break;
2110 default:
2111 BUG();
2112 }
2113 }
2114
2115 if (kick)
2116 ocfs2_wake_downconvert_thread(osb);
2117}
2118
2119#define OCFS2_SEC_BITS 34
2120#define OCFS2_SEC_SHIFT (64 - 34)
2121#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
2122
2123/* LVB only has room for 64 bits of time here so we pack it for
2124 * now. */
2125static u64 ocfs2_pack_timespec(struct timespec *spec)
2126{
2127 u64 res;
2128 u64 sec = spec->tv_sec;
2129 u32 nsec = spec->tv_nsec;
2130
2131 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
2132
2133 return res;
2134}
2135
2136/* Call this with the lockres locked. I am reasonably sure we don't
2137 * need ip_lock in this function as anyone who would be changing those
2138 * values is supposed to be blocked in ocfs2_inode_lock right now. */
2139static void __ocfs2_stuff_meta_lvb(struct inode *inode)
2140{
2141 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2142 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2143 struct ocfs2_meta_lvb *lvb;
2144
2145 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2146
2147 /*
2148 * Invalidate the LVB of a deleted inode - this way other
2149 * nodes are forced to go to disk and discover the new inode
2150 * status.
2151 */
2152 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2153 lvb->lvb_version = 0;
2154 goto out;
2155 }
2156
2157 lvb->lvb_version = OCFS2_LVB_VERSION;
2158 lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
2159 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
2160 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode));
2161 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
2162 lvb->lvb_imode = cpu_to_be16(inode->i_mode);
2163 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
2164 lvb->lvb_iatime_packed =
2165 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
2166 lvb->lvb_ictime_packed =
2167 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
2168 lvb->lvb_imtime_packed =
2169 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
2170 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
2171 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
2172 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
2173
2174out:
2175 mlog_meta_lvb(0, lockres);
2176}
2177
2178static void ocfs2_unpack_timespec(struct timespec *spec,
2179 u64 packed_time)
2180{
2181 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
2182 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
2183}
2184
2185static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
2186{
2187 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2188 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2189 struct ocfs2_meta_lvb *lvb;
2190
2191 mlog_meta_lvb(0, lockres);
2192
2193 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2194
2195 /* We're safe here without the lockres lock... */
2196 spin_lock(&oi->ip_lock);
2197 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
2198 i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
2199
2200 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
2201 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
2202 ocfs2_set_inode_flags(inode);
2203
2204 /* fast-symlinks are a special case */
2205 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
2206 inode->i_blocks = 0;
2207 else
2208 inode->i_blocks = ocfs2_inode_sector_count(inode);
2209
2210 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid));
2211 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
2212 inode->i_mode = be16_to_cpu(lvb->lvb_imode);
2213 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
2214 ocfs2_unpack_timespec(&inode->i_atime,
2215 be64_to_cpu(lvb->lvb_iatime_packed));
2216 ocfs2_unpack_timespec(&inode->i_mtime,
2217 be64_to_cpu(lvb->lvb_imtime_packed));
2218 ocfs2_unpack_timespec(&inode->i_ctime,
2219 be64_to_cpu(lvb->lvb_ictime_packed));
2220 spin_unlock(&oi->ip_lock);
2221}
2222
2223static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
2224 struct ocfs2_lock_res *lockres)
2225{
2226 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2227
2228 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
2229 && lvb->lvb_version == OCFS2_LVB_VERSION
2230 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
2231 return 1;
2232 return 0;
2233}
2234
2235/* Determine whether a lock resource needs to be refreshed, and
2236 * arbitrate who gets to refresh it.
2237 *
2238 * 0 means no refresh needed.
2239 *
2240 * > 0 means you need to refresh this and you MUST call
2241 * ocfs2_complete_lock_res_refresh afterwards. */
2242static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
2243{
2244 unsigned long flags;
2245 int status = 0;
2246
2247refresh_check:
2248 spin_lock_irqsave(&lockres->l_lock, flags);
2249 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
2250 spin_unlock_irqrestore(&lockres->l_lock, flags);
2251 goto bail;
2252 }
2253
2254 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
2255 spin_unlock_irqrestore(&lockres->l_lock, flags);
2256
2257 ocfs2_wait_on_refreshing_lock(lockres);
2258 goto refresh_check;
2259 }
2260
2261 /* Ok, I'll be the one to refresh this lock. */
2262 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
2263 spin_unlock_irqrestore(&lockres->l_lock, flags);
2264
2265 status = 1;
2266bail:
2267 mlog(0, "status %d\n", status);
2268 return status;
2269}
2270
2271/* If status is non zero, I'll mark it as not being in refresh
2272 * anymroe, but i won't clear the needs refresh flag. */
2273static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
2274 int status)
2275{
2276 unsigned long flags;
2277
2278 spin_lock_irqsave(&lockres->l_lock, flags);
2279 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
2280 if (!status)
2281 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
2282 spin_unlock_irqrestore(&lockres->l_lock, flags);
2283
2284 wake_up(&lockres->l_event);
2285}
2286
2287/* may or may not return a bh if it went to disk. */
2288static int ocfs2_inode_lock_update(struct inode *inode,
2289 struct buffer_head **bh)
2290{
2291 int status = 0;
2292 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2293 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2294 struct ocfs2_dinode *fe;
2295 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2296
2297 if (ocfs2_mount_local(osb))
2298 goto bail;
2299
2300 spin_lock(&oi->ip_lock);
2301 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2302 mlog(0, "Orphaned inode %llu was deleted while we "
2303 "were waiting on a lock. ip_flags = 0x%x\n",
2304 (unsigned long long)oi->ip_blkno, oi->ip_flags);
2305 spin_unlock(&oi->ip_lock);
2306 status = -ENOENT;
2307 goto bail;
2308 }
2309 spin_unlock(&oi->ip_lock);
2310
2311 if (!ocfs2_should_refresh_lock_res(lockres))
2312 goto bail;
2313
2314 /* This will discard any caching information we might have had
2315 * for the inode metadata. */
2316 ocfs2_metadata_cache_purge(INODE_CACHE(inode));
2317
2318 ocfs2_extent_map_trunc(inode, 0);
2319
2320 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
2321 mlog(0, "Trusting LVB on inode %llu\n",
2322 (unsigned long long)oi->ip_blkno);
2323 ocfs2_refresh_inode_from_lvb(inode);
2324 } else {
2325 /* Boo, we have to go to disk. */
2326 /* read bh, cast, ocfs2_refresh_inode */
2327 status = ocfs2_read_inode_block(inode, bh);
2328 if (status < 0) {
2329 mlog_errno(status);
2330 goto bail_refresh;
2331 }
2332 fe = (struct ocfs2_dinode *) (*bh)->b_data;
2333
2334 /* This is a good chance to make sure we're not
2335 * locking an invalid object. ocfs2_read_inode_block()
2336 * already checked that the inode block is sane.
2337 *
2338 * We bug on a stale inode here because we checked
2339 * above whether it was wiped from disk. The wiping
2340 * node provides a guarantee that we receive that
2341 * message and can mark the inode before dropping any
2342 * locks associated with it. */
2343 mlog_bug_on_msg(inode->i_generation !=
2344 le32_to_cpu(fe->i_generation),
2345 "Invalid dinode %llu disk generation: %u "
2346 "inode->i_generation: %u\n",
2347 (unsigned long long)oi->ip_blkno,
2348 le32_to_cpu(fe->i_generation),
2349 inode->i_generation);
2350 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
2351 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
2352 "Stale dinode %llu dtime: %llu flags: 0x%x\n",
2353 (unsigned long long)oi->ip_blkno,
2354 (unsigned long long)le64_to_cpu(fe->i_dtime),
2355 le32_to_cpu(fe->i_flags));
2356
2357 ocfs2_refresh_inode(inode, fe);
2358 ocfs2_track_lock_refresh(lockres);
2359 }
2360
2361 status = 0;
2362bail_refresh:
2363 ocfs2_complete_lock_res_refresh(lockres, status);
2364bail:
2365 return status;
2366}
2367
2368static int ocfs2_assign_bh(struct inode *inode,
2369 struct buffer_head **ret_bh,
2370 struct buffer_head *passed_bh)
2371{
2372 int status;
2373
2374 if (passed_bh) {
2375 /* Ok, the update went to disk for us, use the
2376 * returned bh. */
2377 *ret_bh = passed_bh;
2378 get_bh(*ret_bh);
2379
2380 return 0;
2381 }
2382
2383 status = ocfs2_read_inode_block(inode, ret_bh);
2384 if (status < 0)
2385 mlog_errno(status);
2386
2387 return status;
2388}
2389
2390/*
2391 * returns < 0 error if the callback will never be called, otherwise
2392 * the result of the lock will be communicated via the callback.
2393 */
2394int ocfs2_inode_lock_full_nested(struct inode *inode,
2395 struct buffer_head **ret_bh,
2396 int ex,
2397 int arg_flags,
2398 int subclass)
2399{
2400 int status, level, acquired;
2401 u32 dlm_flags;
2402 struct ocfs2_lock_res *lockres = NULL;
2403 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2404 struct buffer_head *local_bh = NULL;
2405
2406 mlog(0, "inode %llu, take %s META lock\n",
2407 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2408 ex ? "EXMODE" : "PRMODE");
2409
2410 status = 0;
2411 acquired = 0;
2412 /* We'll allow faking a readonly metadata lock for
2413 * rodevices. */
2414 if (ocfs2_is_hard_readonly(osb)) {
2415 if (ex)
2416 status = -EROFS;
2417 goto getbh;
2418 }
2419
2420 if ((arg_flags & OCFS2_META_LOCK_GETBH) ||
2421 ocfs2_mount_local(osb))
2422 goto update;
2423
2424 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2425 ocfs2_wait_for_recovery(osb);
2426
2427 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2428 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2429 dlm_flags = 0;
2430 if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
2431 dlm_flags |= DLM_LKF_NOQUEUE;
2432
2433 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
2434 arg_flags, subclass, _RET_IP_);
2435 if (status < 0) {
2436 if (status != -EAGAIN)
2437 mlog_errno(status);
2438 goto bail;
2439 }
2440
2441 /* Notify the error cleanup path to drop the cluster lock. */
2442 acquired = 1;
2443
2444 /* We wait twice because a node may have died while we were in
2445 * the lower dlm layers. The second time though, we've
2446 * committed to owning this lock so we don't allow signals to
2447 * abort the operation. */
2448 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2449 ocfs2_wait_for_recovery(osb);
2450
2451update:
2452 /*
2453 * We only see this flag if we're being called from
2454 * ocfs2_read_locked_inode(). It means we're locking an inode
2455 * which hasn't been populated yet, so clear the refresh flag
2456 * and let the caller handle it.
2457 */
2458 if (inode->i_state & I_NEW) {
2459 status = 0;
2460 if (lockres)
2461 ocfs2_complete_lock_res_refresh(lockres, 0);
2462 goto bail;
2463 }
2464
2465 /* This is fun. The caller may want a bh back, or it may
2466 * not. ocfs2_inode_lock_update definitely wants one in, but
2467 * may or may not read one, depending on what's in the
2468 * LVB. The result of all of this is that we've *only* gone to
2469 * disk if we have to, so the complexity is worthwhile. */
2470 status = ocfs2_inode_lock_update(inode, &local_bh);
2471 if (status < 0) {
2472 if (status != -ENOENT)
2473 mlog_errno(status);
2474 goto bail;
2475 }
2476getbh:
2477 if (ret_bh) {
2478 status = ocfs2_assign_bh(inode, ret_bh, local_bh);
2479 if (status < 0) {
2480 mlog_errno(status);
2481 goto bail;
2482 }
2483 }
2484
2485bail:
2486 if (status < 0) {
2487 if (ret_bh && (*ret_bh)) {
2488 brelse(*ret_bh);
2489 *ret_bh = NULL;
2490 }
2491 if (acquired)
2492 ocfs2_inode_unlock(inode, ex);
2493 }
2494
2495 if (local_bh)
2496 brelse(local_bh);
2497
2498 return status;
2499}
2500
2501/*
2502 * This is working around a lock inversion between tasks acquiring DLM
2503 * locks while holding a page lock and the downconvert thread which
2504 * blocks dlm lock acquiry while acquiring page locks.
2505 *
2506 * ** These _with_page variantes are only intended to be called from aop
2507 * methods that hold page locks and return a very specific *positive* error
2508 * code that aop methods pass up to the VFS -- test for errors with != 0. **
2509 *
2510 * The DLM is called such that it returns -EAGAIN if it would have
2511 * blocked waiting for the downconvert thread. In that case we unlock
2512 * our page so the downconvert thread can make progress. Once we've
2513 * done this we have to return AOP_TRUNCATED_PAGE so the aop method
2514 * that called us can bubble that back up into the VFS who will then
2515 * immediately retry the aop call.
2516 */
2517int ocfs2_inode_lock_with_page(struct inode *inode,
2518 struct buffer_head **ret_bh,
2519 int ex,
2520 struct page *page)
2521{
2522 int ret;
2523
2524 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
2525 if (ret == -EAGAIN) {
2526 unlock_page(page);
2527 /*
2528 * If we can't get inode lock immediately, we should not return
2529 * directly here, since this will lead to a softlockup problem.
2530 * The method is to get a blocking lock and immediately unlock
2531 * before returning, this can avoid CPU resource waste due to
2532 * lots of retries, and benefits fairness in getting lock.
2533 */
2534 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
2535 ocfs2_inode_unlock(inode, ex);
2536 ret = AOP_TRUNCATED_PAGE;
2537 }
2538
2539 return ret;
2540}
2541
2542int ocfs2_inode_lock_atime(struct inode *inode,
2543 struct vfsmount *vfsmnt,
2544 int *level, int wait)
2545{
2546 int ret;
2547
2548 if (wait)
2549 ret = ocfs2_inode_lock(inode, NULL, 0);
2550 else
2551 ret = ocfs2_try_inode_lock(inode, NULL, 0);
2552
2553 if (ret < 0) {
2554 if (ret != -EAGAIN)
2555 mlog_errno(ret);
2556 return ret;
2557 }
2558
2559 /*
2560 * If we should update atime, we will get EX lock,
2561 * otherwise we just get PR lock.
2562 */
2563 if (ocfs2_should_update_atime(inode, vfsmnt)) {
2564 struct buffer_head *bh = NULL;
2565
2566 ocfs2_inode_unlock(inode, 0);
2567 if (wait)
2568 ret = ocfs2_inode_lock(inode, &bh, 1);
2569 else
2570 ret = ocfs2_try_inode_lock(inode, &bh, 1);
2571
2572 if (ret < 0) {
2573 if (ret != -EAGAIN)
2574 mlog_errno(ret);
2575 return ret;
2576 }
2577 *level = 1;
2578 if (ocfs2_should_update_atime(inode, vfsmnt))
2579 ocfs2_update_inode_atime(inode, bh);
2580 if (bh)
2581 brelse(bh);
2582 } else
2583 *level = 0;
2584
2585 return ret;
2586}
2587
2588void ocfs2_inode_unlock(struct inode *inode,
2589 int ex)
2590{
2591 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2592 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
2593 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2594
2595 mlog(0, "inode %llu drop %s META lock\n",
2596 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2597 ex ? "EXMODE" : "PRMODE");
2598
2599 if (!ocfs2_is_hard_readonly(osb) &&
2600 !ocfs2_mount_local(osb))
2601 ocfs2_cluster_unlock(osb, lockres, level);
2602}
2603
2604/*
2605 * This _tracker variantes are introduced to deal with the recursive cluster
2606 * locking issue. The idea is to keep track of a lock holder on the stack of
2607 * the current process. If there's a lock holder on the stack, we know the
2608 * task context is already protected by cluster locking. Currently, they're
2609 * used in some VFS entry routines.
2610 *
2611 * return < 0 on error, return == 0 if there's no lock holder on the stack
2612 * before this call, return == 1 if this call would be a recursive locking.
2613 */
2614int ocfs2_inode_lock_tracker(struct inode *inode,
2615 struct buffer_head **ret_bh,
2616 int ex,
2617 struct ocfs2_lock_holder *oh)
2618{
2619 int status;
2620 int arg_flags = 0, has_locked;
2621 struct ocfs2_lock_res *lockres;
2622
2623 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2624 has_locked = ocfs2_is_locked_by_me(lockres);
2625 /* Just get buffer head if the cluster lock has been taken */
2626 if (has_locked)
2627 arg_flags = OCFS2_META_LOCK_GETBH;
2628
2629 if (likely(!has_locked || ret_bh)) {
2630 status = ocfs2_inode_lock_full(inode, ret_bh, ex, arg_flags);
2631 if (status < 0) {
2632 if (status != -ENOENT)
2633 mlog_errno(status);
2634 return status;
2635 }
2636 }
2637 if (!has_locked)
2638 ocfs2_add_holder(lockres, oh);
2639
2640 return has_locked;
2641}
2642
2643void ocfs2_inode_unlock_tracker(struct inode *inode,
2644 int ex,
2645 struct ocfs2_lock_holder *oh,
2646 int had_lock)
2647{
2648 struct ocfs2_lock_res *lockres;
2649
2650 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2651 /* had_lock means that the currect process already takes the cluster
2652 * lock previously. If had_lock is 1, we have nothing to do here, and
2653 * it will get unlocked where we got the lock.
2654 */
2655 if (!had_lock) {
2656 ocfs2_remove_holder(lockres, oh);
2657 ocfs2_inode_unlock(inode, ex);
2658 }
2659}
2660
2661int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
2662{
2663 struct ocfs2_lock_res *lockres;
2664 struct ocfs2_orphan_scan_lvb *lvb;
2665 int status = 0;
2666
2667 if (ocfs2_is_hard_readonly(osb))
2668 return -EROFS;
2669
2670 if (ocfs2_mount_local(osb))
2671 return 0;
2672
2673 lockres = &osb->osb_orphan_scan.os_lockres;
2674 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2675 if (status < 0)
2676 return status;
2677
2678 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2679 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2680 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
2681 *seqno = be32_to_cpu(lvb->lvb_os_seqno);
2682 else
2683 *seqno = osb->osb_orphan_scan.os_seqno + 1;
2684
2685 return status;
2686}
2687
2688void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
2689{
2690 struct ocfs2_lock_res *lockres;
2691 struct ocfs2_orphan_scan_lvb *lvb;
2692
2693 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
2694 lockres = &osb->osb_orphan_scan.os_lockres;
2695 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2696 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
2697 lvb->lvb_os_seqno = cpu_to_be32(seqno);
2698 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2699 }
2700}
2701
2702int ocfs2_super_lock(struct ocfs2_super *osb,
2703 int ex)
2704{
2705 int status = 0;
2706 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2707 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2708
2709 if (ocfs2_is_hard_readonly(osb))
2710 return -EROFS;
2711
2712 if (ocfs2_mount_local(osb))
2713 goto bail;
2714
2715 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
2716 if (status < 0) {
2717 mlog_errno(status);
2718 goto bail;
2719 }
2720
2721 /* The super block lock path is really in the best position to
2722 * know when resources covered by the lock need to be
2723 * refreshed, so we do it here. Of course, making sense of
2724 * everything is up to the caller :) */
2725 status = ocfs2_should_refresh_lock_res(lockres);
2726 if (status) {
2727 status = ocfs2_refresh_slot_info(osb);
2728
2729 ocfs2_complete_lock_res_refresh(lockres, status);
2730
2731 if (status < 0) {
2732 ocfs2_cluster_unlock(osb, lockres, level);
2733 mlog_errno(status);
2734 }
2735 ocfs2_track_lock_refresh(lockres);
2736 }
2737bail:
2738 return status;
2739}
2740
2741void ocfs2_super_unlock(struct ocfs2_super *osb,
2742 int ex)
2743{
2744 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2745 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2746
2747 if (!ocfs2_mount_local(osb))
2748 ocfs2_cluster_unlock(osb, lockres, level);
2749}
2750
2751int ocfs2_rename_lock(struct ocfs2_super *osb)
2752{
2753 int status;
2754 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2755
2756 if (ocfs2_is_hard_readonly(osb))
2757 return -EROFS;
2758
2759 if (ocfs2_mount_local(osb))
2760 return 0;
2761
2762 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2763 if (status < 0)
2764 mlog_errno(status);
2765
2766 return status;
2767}
2768
2769void ocfs2_rename_unlock(struct ocfs2_super *osb)
2770{
2771 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2772
2773 if (!ocfs2_mount_local(osb))
2774 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2775}
2776
2777int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
2778{
2779 int status;
2780 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2781
2782 if (ocfs2_is_hard_readonly(osb))
2783 return -EROFS;
2784
2785 if (ocfs2_mount_local(osb))
2786 return 0;
2787
2788 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
2789 0, 0);
2790 if (status < 0)
2791 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
2792
2793 return status;
2794}
2795
2796void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
2797{
2798 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2799
2800 if (!ocfs2_mount_local(osb))
2801 ocfs2_cluster_unlock(osb, lockres,
2802 ex ? LKM_EXMODE : LKM_PRMODE);
2803}
2804
2805int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
2806 struct ocfs2_trim_fs_info *info, int trylock)
2807{
2808 int status;
2809 struct ocfs2_trim_fs_lvb *lvb;
2810 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2811
2812 if (info)
2813 info->tf_valid = 0;
2814
2815 if (ocfs2_is_hard_readonly(osb))
2816 return -EROFS;
2817
2818 if (ocfs2_mount_local(osb))
2819 return 0;
2820
2821 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX,
2822 trylock ? DLM_LKF_NOQUEUE : 0, 0);
2823 if (status < 0) {
2824 if (status != -EAGAIN)
2825 mlog_errno(status);
2826 return status;
2827 }
2828
2829 if (info) {
2830 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2831 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2832 lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) {
2833 info->tf_valid = 1;
2834 info->tf_success = lvb->lvb_success;
2835 info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum);
2836 info->tf_start = be64_to_cpu(lvb->lvb_start);
2837 info->tf_len = be64_to_cpu(lvb->lvb_len);
2838 info->tf_minlen = be64_to_cpu(lvb->lvb_minlen);
2839 info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen);
2840 }
2841 }
2842
2843 return status;
2844}
2845
2846void ocfs2_trim_fs_unlock(struct ocfs2_super *osb,
2847 struct ocfs2_trim_fs_info *info)
2848{
2849 struct ocfs2_trim_fs_lvb *lvb;
2850 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2851
2852 if (ocfs2_mount_local(osb))
2853 return;
2854
2855 if (info) {
2856 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2857 lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION;
2858 lvb->lvb_success = info->tf_success;
2859 lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum);
2860 lvb->lvb_start = cpu_to_be64(info->tf_start);
2861 lvb->lvb_len = cpu_to_be64(info->tf_len);
2862 lvb->lvb_minlen = cpu_to_be64(info->tf_minlen);
2863 lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen);
2864 }
2865
2866 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2867}
2868
2869int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2870{
2871 int ret;
2872 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2873 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2874 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2875
2876 BUG_ON(!dl);
2877
2878 if (ocfs2_is_hard_readonly(osb)) {
2879 if (ex)
2880 return -EROFS;
2881 return 0;
2882 }
2883
2884 if (ocfs2_mount_local(osb))
2885 return 0;
2886
2887 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2888 if (ret < 0)
2889 mlog_errno(ret);
2890
2891 return ret;
2892}
2893
2894void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2895{
2896 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2897 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2898 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2899
2900 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
2901 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
2902}
2903
2904/* Reference counting of the dlm debug structure. We want this because
2905 * open references on the debug inodes can live on after a mount, so
2906 * we can't rely on the ocfs2_super to always exist. */
2907static void ocfs2_dlm_debug_free(struct kref *kref)
2908{
2909 struct ocfs2_dlm_debug *dlm_debug;
2910
2911 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
2912
2913 kfree(dlm_debug);
2914}
2915
2916void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
2917{
2918 if (dlm_debug)
2919 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
2920}
2921
2922static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
2923{
2924 kref_get(&debug->d_refcnt);
2925}
2926
2927struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
2928{
2929 struct ocfs2_dlm_debug *dlm_debug;
2930
2931 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
2932 if (!dlm_debug) {
2933 mlog_errno(-ENOMEM);
2934 goto out;
2935 }
2936
2937 kref_init(&dlm_debug->d_refcnt);
2938 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
2939 dlm_debug->d_locking_state = NULL;
2940out:
2941 return dlm_debug;
2942}
2943
2944/* Access to this is arbitrated for us via seq_file->sem. */
2945struct ocfs2_dlm_seq_priv {
2946 struct ocfs2_dlm_debug *p_dlm_debug;
2947 struct ocfs2_lock_res p_iter_res;
2948 struct ocfs2_lock_res p_tmp_res;
2949};
2950
2951static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
2952 struct ocfs2_dlm_seq_priv *priv)
2953{
2954 struct ocfs2_lock_res *iter, *ret = NULL;
2955 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
2956
2957 assert_spin_locked(&ocfs2_dlm_tracking_lock);
2958
2959 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
2960 /* discover the head of the list */
2961 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
2962 mlog(0, "End of list found, %p\n", ret);
2963 break;
2964 }
2965
2966 /* We track our "dummy" iteration lockres' by a NULL
2967 * l_ops field. */
2968 if (iter->l_ops != NULL) {
2969 ret = iter;
2970 break;
2971 }
2972 }
2973
2974 return ret;
2975}
2976
2977static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
2978{
2979 struct ocfs2_dlm_seq_priv *priv = m->private;
2980 struct ocfs2_lock_res *iter;
2981
2982 spin_lock(&ocfs2_dlm_tracking_lock);
2983 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
2984 if (iter) {
2985 /* Since lockres' have the lifetime of their container
2986 * (which can be inodes, ocfs2_supers, etc) we want to
2987 * copy this out to a temporary lockres while still
2988 * under the spinlock. Obviously after this we can't
2989 * trust any pointers on the copy returned, but that's
2990 * ok as the information we want isn't typically held
2991 * in them. */
2992 priv->p_tmp_res = *iter;
2993 iter = &priv->p_tmp_res;
2994 }
2995 spin_unlock(&ocfs2_dlm_tracking_lock);
2996
2997 return iter;
2998}
2999
3000static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
3001{
3002}
3003
3004static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
3005{
3006 struct ocfs2_dlm_seq_priv *priv = m->private;
3007 struct ocfs2_lock_res *iter = v;
3008 struct ocfs2_lock_res *dummy = &priv->p_iter_res;
3009
3010 spin_lock(&ocfs2_dlm_tracking_lock);
3011 iter = ocfs2_dlm_next_res(iter, priv);
3012 list_del_init(&dummy->l_debug_list);
3013 if (iter) {
3014 list_add(&dummy->l_debug_list, &iter->l_debug_list);
3015 priv->p_tmp_res = *iter;
3016 iter = &priv->p_tmp_res;
3017 }
3018 spin_unlock(&ocfs2_dlm_tracking_lock);
3019
3020 return iter;
3021}
3022
3023/*
3024 * Version is used by debugfs.ocfs2 to determine the format being used
3025 *
3026 * New in version 2
3027 * - Lock stats printed
3028 * New in version 3
3029 * - Max time in lock stats is in usecs (instead of nsecs)
3030 */
3031#define OCFS2_DLM_DEBUG_STR_VERSION 3
3032static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
3033{
3034 int i;
3035 char *lvb;
3036 struct ocfs2_lock_res *lockres = v;
3037
3038 if (!lockres)
3039 return -EINVAL;
3040
3041 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
3042
3043 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
3044 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
3045 lockres->l_name,
3046 (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
3047 else
3048 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
3049
3050 seq_printf(m, "%d\t"
3051 "0x%lx\t"
3052 "0x%x\t"
3053 "0x%x\t"
3054 "%u\t"
3055 "%u\t"
3056 "%d\t"
3057 "%d\t",
3058 lockres->l_level,
3059 lockres->l_flags,
3060 lockres->l_action,
3061 lockres->l_unlock_action,
3062 lockres->l_ro_holders,
3063 lockres->l_ex_holders,
3064 lockres->l_requested,
3065 lockres->l_blocking);
3066
3067 /* Dump the raw LVB */
3068 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
3069 for(i = 0; i < DLM_LVB_LEN; i++)
3070 seq_printf(m, "0x%x\t", lvb[i]);
3071
3072#ifdef CONFIG_OCFS2_FS_STATS
3073# define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets)
3074# define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets)
3075# define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail)
3076# define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail)
3077# define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total)
3078# define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total)
3079# define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max)
3080# define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max)
3081# define lock_refresh(_l) ((_l)->l_lock_refresh)
3082#else
3083# define lock_num_prmode(_l) (0)
3084# define lock_num_exmode(_l) (0)
3085# define lock_num_prmode_failed(_l) (0)
3086# define lock_num_exmode_failed(_l) (0)
3087# define lock_total_prmode(_l) (0ULL)
3088# define lock_total_exmode(_l) (0ULL)
3089# define lock_max_prmode(_l) (0)
3090# define lock_max_exmode(_l) (0)
3091# define lock_refresh(_l) (0)
3092#endif
3093 /* The following seq_print was added in version 2 of this output */
3094 seq_printf(m, "%u\t"
3095 "%u\t"
3096 "%u\t"
3097 "%u\t"
3098 "%llu\t"
3099 "%llu\t"
3100 "%u\t"
3101 "%u\t"
3102 "%u\t",
3103 lock_num_prmode(lockres),
3104 lock_num_exmode(lockres),
3105 lock_num_prmode_failed(lockres),
3106 lock_num_exmode_failed(lockres),
3107 lock_total_prmode(lockres),
3108 lock_total_exmode(lockres),
3109 lock_max_prmode(lockres),
3110 lock_max_exmode(lockres),
3111 lock_refresh(lockres));
3112
3113 /* End the line */
3114 seq_printf(m, "\n");
3115 return 0;
3116}
3117
3118static const struct seq_operations ocfs2_dlm_seq_ops = {
3119 .start = ocfs2_dlm_seq_start,
3120 .stop = ocfs2_dlm_seq_stop,
3121 .next = ocfs2_dlm_seq_next,
3122 .show = ocfs2_dlm_seq_show,
3123};
3124
3125static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
3126{
3127 struct seq_file *seq = file->private_data;
3128 struct ocfs2_dlm_seq_priv *priv = seq->private;
3129 struct ocfs2_lock_res *res = &priv->p_iter_res;
3130
3131 ocfs2_remove_lockres_tracking(res);
3132 ocfs2_put_dlm_debug(priv->p_dlm_debug);
3133 return seq_release_private(inode, file);
3134}
3135
3136static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
3137{
3138 struct ocfs2_dlm_seq_priv *priv;
3139 struct ocfs2_super *osb;
3140
3141 priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv));
3142 if (!priv) {
3143 mlog_errno(-ENOMEM);
3144 return -ENOMEM;
3145 }
3146
3147 osb = inode->i_private;
3148 ocfs2_get_dlm_debug(osb->osb_dlm_debug);
3149 priv->p_dlm_debug = osb->osb_dlm_debug;
3150 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
3151
3152 ocfs2_add_lockres_tracking(&priv->p_iter_res,
3153 priv->p_dlm_debug);
3154
3155 return 0;
3156}
3157
3158static const struct file_operations ocfs2_dlm_debug_fops = {
3159 .open = ocfs2_dlm_debug_open,
3160 .release = ocfs2_dlm_debug_release,
3161 .read = seq_read,
3162 .llseek = seq_lseek,
3163};
3164
3165static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
3166{
3167 int ret = 0;
3168 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
3169
3170 dlm_debug->d_locking_state = debugfs_create_file("locking_state",
3171 S_IFREG|S_IRUSR,
3172 osb->osb_debug_root,
3173 osb,
3174 &ocfs2_dlm_debug_fops);
3175 if (!dlm_debug->d_locking_state) {
3176 ret = -EINVAL;
3177 mlog(ML_ERROR,
3178 "Unable to create locking state debugfs file.\n");
3179 goto out;
3180 }
3181
3182 ocfs2_get_dlm_debug(dlm_debug);
3183out:
3184 return ret;
3185}
3186
3187static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
3188{
3189 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
3190
3191 if (dlm_debug) {
3192 debugfs_remove(dlm_debug->d_locking_state);
3193 ocfs2_put_dlm_debug(dlm_debug);
3194 }
3195}
3196
3197int ocfs2_dlm_init(struct ocfs2_super *osb)
3198{
3199 int status = 0;
3200 struct ocfs2_cluster_connection *conn = NULL;
3201
3202 if (ocfs2_mount_local(osb)) {
3203 osb->node_num = 0;
3204 goto local;
3205 }
3206
3207 status = ocfs2_dlm_init_debug(osb);
3208 if (status < 0) {
3209 mlog_errno(status);
3210 goto bail;
3211 }
3212
3213 /* launch downconvert thread */
3214 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s",
3215 osb->uuid_str);
3216 if (IS_ERR(osb->dc_task)) {
3217 status = PTR_ERR(osb->dc_task);
3218 osb->dc_task = NULL;
3219 mlog_errno(status);
3220 goto bail;
3221 }
3222
3223 /* for now, uuid == domain */
3224 status = ocfs2_cluster_connect(osb->osb_cluster_stack,
3225 osb->osb_cluster_name,
3226 strlen(osb->osb_cluster_name),
3227 osb->uuid_str,
3228 strlen(osb->uuid_str),
3229 &lproto, ocfs2_do_node_down, osb,
3230 &conn);
3231 if (status) {
3232 mlog_errno(status);
3233 goto bail;
3234 }
3235
3236 status = ocfs2_cluster_this_node(conn, &osb->node_num);
3237 if (status < 0) {
3238 mlog_errno(status);
3239 mlog(ML_ERROR,
3240 "could not find this host's node number\n");
3241 ocfs2_cluster_disconnect(conn, 0);
3242 goto bail;
3243 }
3244
3245local:
3246 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
3247 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
3248 ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
3249 ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
3250
3251 osb->cconn = conn;
3252bail:
3253 if (status < 0) {
3254 ocfs2_dlm_shutdown_debug(osb);
3255 if (osb->dc_task)
3256 kthread_stop(osb->dc_task);
3257 }
3258
3259 return status;
3260}
3261
3262void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
3263 int hangup_pending)
3264{
3265 ocfs2_drop_osb_locks(osb);
3266
3267 /*
3268 * Now that we have dropped all locks and ocfs2_dismount_volume()
3269 * has disabled recovery, the DLM won't be talking to us. It's
3270 * safe to tear things down before disconnecting the cluster.
3271 */
3272
3273 if (osb->dc_task) {
3274 kthread_stop(osb->dc_task);
3275 osb->dc_task = NULL;
3276 }
3277
3278 ocfs2_lock_res_free(&osb->osb_super_lockres);
3279 ocfs2_lock_res_free(&osb->osb_rename_lockres);
3280 ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
3281 ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
3282
3283 ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
3284 osb->cconn = NULL;
3285
3286 ocfs2_dlm_shutdown_debug(osb);
3287}
3288
3289static int ocfs2_drop_lock(struct ocfs2_super *osb,
3290 struct ocfs2_lock_res *lockres)
3291{
3292 int ret;
3293 unsigned long flags;
3294 u32 lkm_flags = 0;
3295
3296 /* We didn't get anywhere near actually using this lockres. */
3297 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
3298 goto out;
3299
3300 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3301 lkm_flags |= DLM_LKF_VALBLK;
3302
3303 spin_lock_irqsave(&lockres->l_lock, flags);
3304
3305 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
3306 "lockres %s, flags 0x%lx\n",
3307 lockres->l_name, lockres->l_flags);
3308
3309 while (lockres->l_flags & OCFS2_LOCK_BUSY) {
3310 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
3311 "%u, unlock_action = %u\n",
3312 lockres->l_name, lockres->l_flags, lockres->l_action,
3313 lockres->l_unlock_action);
3314
3315 spin_unlock_irqrestore(&lockres->l_lock, flags);
3316
3317 /* XXX: Today we just wait on any busy
3318 * locks... Perhaps we need to cancel converts in the
3319 * future? */
3320 ocfs2_wait_on_busy_lock(lockres);
3321
3322 spin_lock_irqsave(&lockres->l_lock, flags);
3323 }
3324
3325 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3326 if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
3327 lockres->l_level == DLM_LOCK_EX &&
3328 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3329 lockres->l_ops->set_lvb(lockres);
3330 }
3331
3332 if (lockres->l_flags & OCFS2_LOCK_BUSY)
3333 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
3334 lockres->l_name);
3335 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
3336 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
3337
3338 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
3339 spin_unlock_irqrestore(&lockres->l_lock, flags);
3340 goto out;
3341 }
3342
3343 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
3344
3345 /* make sure we never get here while waiting for an ast to
3346 * fire. */
3347 BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
3348
3349 /* is this necessary? */
3350 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3351 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
3352 spin_unlock_irqrestore(&lockres->l_lock, flags);
3353
3354 mlog(0, "lock %s\n", lockres->l_name);
3355
3356 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags);
3357 if (ret) {
3358 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3359 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
3360 ocfs2_dlm_dump_lksb(&lockres->l_lksb);
3361 BUG();
3362 }
3363 mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n",
3364 lockres->l_name);
3365
3366 ocfs2_wait_on_busy_lock(lockres);
3367out:
3368 return 0;
3369}
3370
3371static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3372 struct ocfs2_lock_res *lockres);
3373
3374/* Mark the lockres as being dropped. It will no longer be
3375 * queued if blocking, but we still may have to wait on it
3376 * being dequeued from the downconvert thread before we can consider
3377 * it safe to drop.
3378 *
3379 * You can *not* attempt to call cluster_lock on this lockres anymore. */
3380void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb,
3381 struct ocfs2_lock_res *lockres)
3382{
3383 int status;
3384 struct ocfs2_mask_waiter mw;
3385 unsigned long flags, flags2;
3386
3387 ocfs2_init_mask_waiter(&mw);
3388
3389 spin_lock_irqsave(&lockres->l_lock, flags);
3390 lockres->l_flags |= OCFS2_LOCK_FREEING;
3391 if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) {
3392 /*
3393 * We know the downconvert is queued but not in progress
3394 * because we are the downconvert thread and processing
3395 * different lock. So we can just remove the lock from the
3396 * queue. This is not only an optimization but also a way
3397 * to avoid the following deadlock:
3398 * ocfs2_dentry_post_unlock()
3399 * ocfs2_dentry_lock_put()
3400 * ocfs2_drop_dentry_lock()
3401 * iput()
3402 * ocfs2_evict_inode()
3403 * ocfs2_clear_inode()
3404 * ocfs2_mark_lockres_freeing()
3405 * ... blocks waiting for OCFS2_LOCK_QUEUED
3406 * since we are the downconvert thread which
3407 * should clear the flag.
3408 */
3409 spin_unlock_irqrestore(&lockres->l_lock, flags);
3410 spin_lock_irqsave(&osb->dc_task_lock, flags2);
3411 list_del_init(&lockres->l_blocked_list);
3412 osb->blocked_lock_count--;
3413 spin_unlock_irqrestore(&osb->dc_task_lock, flags2);
3414 /*
3415 * Warn if we recurse into another post_unlock call. Strictly
3416 * speaking it isn't a problem but we need to be careful if
3417 * that happens (stack overflow, deadlocks, ...) so warn if
3418 * ocfs2 grows a path for which this can happen.
3419 */
3420 WARN_ON_ONCE(lockres->l_ops->post_unlock);
3421 /* Since the lock is freeing we don't do much in the fn below */
3422 ocfs2_process_blocked_lock(osb, lockres);
3423 return;
3424 }
3425 while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
3426 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
3427 spin_unlock_irqrestore(&lockres->l_lock, flags);
3428
3429 mlog(0, "Waiting on lockres %s\n", lockres->l_name);
3430
3431 status = ocfs2_wait_for_mask(&mw);
3432 if (status)
3433 mlog_errno(status);
3434
3435 spin_lock_irqsave(&lockres->l_lock, flags);
3436 }
3437 spin_unlock_irqrestore(&lockres->l_lock, flags);
3438}
3439
3440void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
3441 struct ocfs2_lock_res *lockres)
3442{
3443 int ret;
3444
3445 ocfs2_mark_lockres_freeing(osb, lockres);
3446 ret = ocfs2_drop_lock(osb, lockres);
3447 if (ret)
3448 mlog_errno(ret);
3449}
3450
3451static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
3452{
3453 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
3454 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
3455 ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
3456 ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
3457}
3458
3459int ocfs2_drop_inode_locks(struct inode *inode)
3460{
3461 int status, err;
3462
3463 /* No need to call ocfs2_mark_lockres_freeing here -
3464 * ocfs2_clear_inode has done it for us. */
3465
3466 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3467 &OCFS2_I(inode)->ip_open_lockres);
3468 if (err < 0)
3469 mlog_errno(err);
3470
3471 status = err;
3472
3473 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3474 &OCFS2_I(inode)->ip_inode_lockres);
3475 if (err < 0)
3476 mlog_errno(err);
3477 if (err < 0 && !status)
3478 status = err;
3479
3480 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3481 &OCFS2_I(inode)->ip_rw_lockres);
3482 if (err < 0)
3483 mlog_errno(err);
3484 if (err < 0 && !status)
3485 status = err;
3486
3487 return status;
3488}
3489
3490static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
3491 int new_level)
3492{
3493 assert_spin_locked(&lockres->l_lock);
3494
3495 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
3496
3497 if (lockres->l_level <= new_level) {
3498 mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
3499 "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
3500 "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
3501 new_level, list_empty(&lockres->l_blocked_list),
3502 list_empty(&lockres->l_mask_waiters), lockres->l_type,
3503 lockres->l_flags, lockres->l_ro_holders,
3504 lockres->l_ex_holders, lockres->l_action,
3505 lockres->l_unlock_action, lockres->l_requested,
3506 lockres->l_blocking, lockres->l_pending_gen);
3507 BUG();
3508 }
3509
3510 mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
3511 lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
3512
3513 lockres->l_action = OCFS2_AST_DOWNCONVERT;
3514 lockres->l_requested = new_level;
3515 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3516 return lockres_set_pending(lockres);
3517}
3518
3519static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
3520 struct ocfs2_lock_res *lockres,
3521 int new_level,
3522 int lvb,
3523 unsigned int generation)
3524{
3525 int ret;
3526 u32 dlm_flags = DLM_LKF_CONVERT;
3527
3528 mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
3529 lockres->l_level, new_level);
3530
3531 /*
3532 * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always
3533 * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that
3534 * we can recover correctly from node failure. Otherwise, we may get
3535 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set.
3536 */
3537 if (!ocfs2_is_o2cb_active() &&
3538 lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3539 lvb = 1;
3540
3541 if (lvb)
3542 dlm_flags |= DLM_LKF_VALBLK;
3543
3544 ret = ocfs2_dlm_lock(osb->cconn,
3545 new_level,
3546 &lockres->l_lksb,
3547 dlm_flags,
3548 lockres->l_name,
3549 OCFS2_LOCK_ID_MAX_LEN - 1);
3550 lockres_clear_pending(lockres, generation, osb);
3551 if (ret) {
3552 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
3553 ocfs2_recover_from_dlm_error(lockres, 1);
3554 goto bail;
3555 }
3556
3557 ret = 0;
3558bail:
3559 return ret;
3560}
3561
3562/* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */
3563static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
3564 struct ocfs2_lock_res *lockres)
3565{
3566 assert_spin_locked(&lockres->l_lock);
3567
3568 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
3569 /* If we're already trying to cancel a lock conversion
3570 * then just drop the spinlock and allow the caller to
3571 * requeue this lock. */
3572 mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
3573 return 0;
3574 }
3575
3576 /* were we in a convert when we got the bast fire? */
3577 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
3578 lockres->l_action != OCFS2_AST_DOWNCONVERT);
3579 /* set things up for the unlockast to know to just
3580 * clear out the ast_action and unset busy, etc. */
3581 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
3582
3583 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
3584 "lock %s, invalid flags: 0x%lx\n",
3585 lockres->l_name, lockres->l_flags);
3586
3587 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3588
3589 return 1;
3590}
3591
3592static int ocfs2_cancel_convert(struct ocfs2_super *osb,
3593 struct ocfs2_lock_res *lockres)
3594{
3595 int ret;
3596
3597 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
3598 DLM_LKF_CANCEL);
3599 if (ret) {
3600 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3601 ocfs2_recover_from_dlm_error(lockres, 0);
3602 }
3603
3604 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3605
3606 return ret;
3607}
3608
3609static int ocfs2_unblock_lock(struct ocfs2_super *osb,
3610 struct ocfs2_lock_res *lockres,
3611 struct ocfs2_unblock_ctl *ctl)
3612{
3613 unsigned long flags;
3614 int blocking;
3615 int new_level;
3616 int level;
3617 int ret = 0;
3618 int set_lvb = 0;
3619 unsigned int gen;
3620
3621 spin_lock_irqsave(&lockres->l_lock, flags);
3622
3623recheck:
3624 /*
3625 * Is it still blocking? If not, we have no more work to do.
3626 */
3627 if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
3628 BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
3629 spin_unlock_irqrestore(&lockres->l_lock, flags);
3630 ret = 0;
3631 goto leave;
3632 }
3633
3634 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
3635 /* XXX
3636 * This is a *big* race. The OCFS2_LOCK_PENDING flag
3637 * exists entirely for one reason - another thread has set
3638 * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock().
3639 *
3640 * If we do ocfs2_cancel_convert() before the other thread
3641 * calls dlm_lock(), our cancel will do nothing. We will
3642 * get no ast, and we will have no way of knowing the
3643 * cancel failed. Meanwhile, the other thread will call
3644 * into dlm_lock() and wait...forever.
3645 *
3646 * Why forever? Because another node has asked for the
3647 * lock first; that's why we're here in unblock_lock().
3648 *
3649 * The solution is OCFS2_LOCK_PENDING. When PENDING is
3650 * set, we just requeue the unblock. Only when the other
3651 * thread has called dlm_lock() and cleared PENDING will
3652 * we then cancel their request.
3653 *
3654 * All callers of dlm_lock() must set OCFS2_DLM_PENDING
3655 * at the same time they set OCFS2_DLM_BUSY. They must
3656 * clear OCFS2_DLM_PENDING after dlm_lock() returns.
3657 */
3658 if (lockres->l_flags & OCFS2_LOCK_PENDING) {
3659 mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
3660 lockres->l_name);
3661 goto leave_requeue;
3662 }
3663
3664 ctl->requeue = 1;
3665 ret = ocfs2_prepare_cancel_convert(osb, lockres);
3666 spin_unlock_irqrestore(&lockres->l_lock, flags);
3667 if (ret) {
3668 ret = ocfs2_cancel_convert(osb, lockres);
3669 if (ret < 0)
3670 mlog_errno(ret);
3671 }
3672 goto leave;
3673 }
3674
3675 /*
3676 * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is
3677 * set when the ast is received for an upconvert just before the
3678 * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast
3679 * on the heels of the ast, we want to delay the downconvert just
3680 * enough to allow the up requestor to do its task. Because this
3681 * lock is in the blocked queue, the lock will be downconverted
3682 * as soon as the requestor is done with the lock.
3683 */
3684 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING)
3685 goto leave_requeue;
3686
3687 /*
3688 * How can we block and yet be at NL? We were trying to upconvert
3689 * from NL and got canceled. The code comes back here, and now
3690 * we notice and clear BLOCKING.
3691 */
3692 if (lockres->l_level == DLM_LOCK_NL) {
3693 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
3694 mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
3695 lockres->l_blocking = DLM_LOCK_NL;
3696 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
3697 spin_unlock_irqrestore(&lockres->l_lock, flags);
3698 goto leave;
3699 }
3700
3701 /* if we're blocking an exclusive and we have *any* holders,
3702 * then requeue. */
3703 if ((lockres->l_blocking == DLM_LOCK_EX)
3704 && (lockres->l_ex_holders || lockres->l_ro_holders)) {
3705 mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
3706 lockres->l_name, lockres->l_ex_holders,
3707 lockres->l_ro_holders);
3708 goto leave_requeue;
3709 }
3710
3711 /* If it's a PR we're blocking, then only
3712 * requeue if we've got any EX holders */
3713 if (lockres->l_blocking == DLM_LOCK_PR &&
3714 lockres->l_ex_holders) {
3715 mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
3716 lockres->l_name, lockres->l_ex_holders);
3717 goto leave_requeue;
3718 }
3719
3720 /*
3721 * Can we get a lock in this state if the holder counts are
3722 * zero? The meta data unblock code used to check this.
3723 */
3724 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
3725 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
3726 mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
3727 lockres->l_name);
3728 goto leave_requeue;
3729 }
3730
3731 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
3732
3733 if (lockres->l_ops->check_downconvert
3734 && !lockres->l_ops->check_downconvert(lockres, new_level)) {
3735 mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
3736 lockres->l_name);
3737 goto leave_requeue;
3738 }
3739
3740 /* If we get here, then we know that there are no more
3741 * incompatible holders (and anyone asking for an incompatible
3742 * lock is blocked). We can now downconvert the lock */
3743 if (!lockres->l_ops->downconvert_worker)
3744 goto downconvert;
3745
3746 /* Some lockres types want to do a bit of work before
3747 * downconverting a lock. Allow that here. The worker function
3748 * may sleep, so we save off a copy of what we're blocking as
3749 * it may change while we're not holding the spin lock. */
3750 blocking = lockres->l_blocking;
3751 level = lockres->l_level;
3752 spin_unlock_irqrestore(&lockres->l_lock, flags);
3753
3754 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
3755
3756 if (ctl->unblock_action == UNBLOCK_STOP_POST) {
3757 mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
3758 lockres->l_name);
3759 goto leave;
3760 }
3761
3762 spin_lock_irqsave(&lockres->l_lock, flags);
3763 if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
3764 /* If this changed underneath us, then we can't drop
3765 * it just yet. */
3766 mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
3767 "Recheck\n", lockres->l_name, blocking,
3768 lockres->l_blocking, level, lockres->l_level);
3769 goto recheck;
3770 }
3771
3772downconvert:
3773 ctl->requeue = 0;
3774
3775 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3776 if (lockres->l_level == DLM_LOCK_EX)
3777 set_lvb = 1;
3778
3779 /*
3780 * We only set the lvb if the lock has been fully
3781 * refreshed - otherwise we risk setting stale
3782 * data. Otherwise, there's no need to actually clear
3783 * out the lvb here as it's value is still valid.
3784 */
3785 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3786 lockres->l_ops->set_lvb(lockres);
3787 }
3788
3789 gen = ocfs2_prepare_downconvert(lockres, new_level);
3790 spin_unlock_irqrestore(&lockres->l_lock, flags);
3791 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
3792 gen);
3793
3794leave:
3795 if (ret)
3796 mlog_errno(ret);
3797 return ret;
3798
3799leave_requeue:
3800 spin_unlock_irqrestore(&lockres->l_lock, flags);
3801 ctl->requeue = 1;
3802
3803 return 0;
3804}
3805
3806static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
3807 int blocking)
3808{
3809 struct inode *inode;
3810 struct address_space *mapping;
3811 struct ocfs2_inode_info *oi;
3812
3813 inode = ocfs2_lock_res_inode(lockres);
3814 mapping = inode->i_mapping;
3815
3816 if (S_ISDIR(inode->i_mode)) {
3817 oi = OCFS2_I(inode);
3818 oi->ip_dir_lock_gen++;
3819 mlog(0, "generation: %u\n", oi->ip_dir_lock_gen);
3820 goto out;
3821 }
3822
3823 if (!S_ISREG(inode->i_mode))
3824 goto out;
3825
3826 /*
3827 * We need this before the filemap_fdatawrite() so that it can
3828 * transfer the dirty bit from the PTE to the
3829 * page. Unfortunately this means that even for EX->PR
3830 * downconverts, we'll lose our mappings and have to build
3831 * them up again.
3832 */
3833 unmap_mapping_range(mapping, 0, 0, 0);
3834
3835 if (filemap_fdatawrite(mapping)) {
3836 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
3837 (unsigned long long)OCFS2_I(inode)->ip_blkno);
3838 }
3839 sync_mapping_buffers(mapping);
3840 if (blocking == DLM_LOCK_EX) {
3841 truncate_inode_pages(mapping, 0);
3842 } else {
3843 /* We only need to wait on the I/O if we're not also
3844 * truncating pages because truncate_inode_pages waits
3845 * for us above. We don't truncate pages if we're
3846 * blocking anything < EXMODE because we want to keep
3847 * them around in that case. */
3848 filemap_fdatawait(mapping);
3849 }
3850
3851 forget_all_cached_acls(inode);
3852
3853out:
3854 return UNBLOCK_CONTINUE;
3855}
3856
3857static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci,
3858 struct ocfs2_lock_res *lockres,
3859 int new_level)
3860{
3861 int checkpointed = ocfs2_ci_fully_checkpointed(ci);
3862
3863 BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
3864 BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
3865
3866 if (checkpointed)
3867 return 1;
3868
3869 ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci)));
3870 return 0;
3871}
3872
3873static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
3874 int new_level)
3875{
3876 struct inode *inode = ocfs2_lock_res_inode(lockres);
3877
3878 return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level);
3879}
3880
3881static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
3882{
3883 struct inode *inode = ocfs2_lock_res_inode(lockres);
3884
3885 __ocfs2_stuff_meta_lvb(inode);
3886}
3887
3888/*
3889 * Does the final reference drop on our dentry lock. Right now this
3890 * happens in the downconvert thread, but we could choose to simplify the
3891 * dlmglue API and push these off to the ocfs2_wq in the future.
3892 */
3893static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
3894 struct ocfs2_lock_res *lockres)
3895{
3896 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
3897 ocfs2_dentry_lock_put(osb, dl);
3898}
3899
3900/*
3901 * d_delete() matching dentries before the lock downconvert.
3902 *
3903 * At this point, any process waiting to destroy the
3904 * dentry_lock due to last ref count is stopped by the
3905 * OCFS2_LOCK_QUEUED flag.
3906 *
3907 * We have two potential problems
3908 *
3909 * 1) If we do the last reference drop on our dentry_lock (via dput)
3910 * we'll wind up in ocfs2_release_dentry_lock(), waiting on
3911 * the downconvert to finish. Instead we take an elevated
3912 * reference and push the drop until after we've completed our
3913 * unblock processing.
3914 *
3915 * 2) There might be another process with a final reference,
3916 * waiting on us to finish processing. If this is the case, we
3917 * detect it and exit out - there's no more dentries anyway.
3918 */
3919static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
3920 int blocking)
3921{
3922 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
3923 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
3924 struct dentry *dentry;
3925 unsigned long flags;
3926 int extra_ref = 0;
3927
3928 /*
3929 * This node is blocking another node from getting a read
3930 * lock. This happens when we've renamed within a
3931 * directory. We've forced the other nodes to d_delete(), but
3932 * we never actually dropped our lock because it's still
3933 * valid. The downconvert code will retain a PR for this node,
3934 * so there's no further work to do.
3935 */
3936 if (blocking == DLM_LOCK_PR)
3937 return UNBLOCK_CONTINUE;
3938
3939 /*
3940 * Mark this inode as potentially orphaned. The code in
3941 * ocfs2_delete_inode() will figure out whether it actually
3942 * needs to be freed or not.
3943 */
3944 spin_lock(&oi->ip_lock);
3945 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
3946 spin_unlock(&oi->ip_lock);
3947
3948 /*
3949 * Yuck. We need to make sure however that the check of
3950 * OCFS2_LOCK_FREEING and the extra reference are atomic with
3951 * respect to a reference decrement or the setting of that
3952 * flag.
3953 */
3954 spin_lock_irqsave(&lockres->l_lock, flags);
3955 spin_lock(&dentry_attach_lock);
3956 if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
3957 && dl->dl_count) {
3958 dl->dl_count++;
3959 extra_ref = 1;
3960 }
3961 spin_unlock(&dentry_attach_lock);
3962 spin_unlock_irqrestore(&lockres->l_lock, flags);
3963
3964 mlog(0, "extra_ref = %d\n", extra_ref);
3965
3966 /*
3967 * We have a process waiting on us in ocfs2_dentry_iput(),
3968 * which means we can't have any more outstanding
3969 * aliases. There's no need to do any more work.
3970 */
3971 if (!extra_ref)
3972 return UNBLOCK_CONTINUE;
3973
3974 spin_lock(&dentry_attach_lock);
3975 while (1) {
3976 dentry = ocfs2_find_local_alias(dl->dl_inode,
3977 dl->dl_parent_blkno, 1);
3978 if (!dentry)
3979 break;
3980 spin_unlock(&dentry_attach_lock);
3981
3982 if (S_ISDIR(dl->dl_inode->i_mode))
3983 shrink_dcache_parent(dentry);
3984
3985 mlog(0, "d_delete(%pd);\n", dentry);
3986
3987 /*
3988 * The following dcache calls may do an
3989 * iput(). Normally we don't want that from the
3990 * downconverting thread, but in this case it's ok
3991 * because the requesting node already has an
3992 * exclusive lock on the inode, so it can't be queued
3993 * for a downconvert.
3994 */
3995 d_delete(dentry);
3996 dput(dentry);
3997
3998 spin_lock(&dentry_attach_lock);
3999 }
4000 spin_unlock(&dentry_attach_lock);
4001
4002 /*
4003 * If we are the last holder of this dentry lock, there is no
4004 * reason to downconvert so skip straight to the unlock.
4005 */
4006 if (dl->dl_count == 1)
4007 return UNBLOCK_STOP_POST;
4008
4009 return UNBLOCK_CONTINUE_POST;
4010}
4011
4012static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
4013 int new_level)
4014{
4015 struct ocfs2_refcount_tree *tree =
4016 ocfs2_lock_res_refcount_tree(lockres);
4017
4018 return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level);
4019}
4020
4021static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
4022 int blocking)
4023{
4024 struct ocfs2_refcount_tree *tree =
4025 ocfs2_lock_res_refcount_tree(lockres);
4026
4027 ocfs2_metadata_cache_purge(&tree->rf_ci);
4028
4029 return UNBLOCK_CONTINUE;
4030}
4031
4032static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
4033{
4034 struct ocfs2_qinfo_lvb *lvb;
4035 struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
4036 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
4037 oinfo->dqi_gi.dqi_type);
4038
4039 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
4040 lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
4041 lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
4042 lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
4043 lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
4044 lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
4045 lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
4046 lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
4047}
4048
4049void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
4050{
4051 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4052 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
4053 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4054
4055 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
4056 ocfs2_cluster_unlock(osb, lockres, level);
4057}
4058
4059static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
4060{
4061 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
4062 oinfo->dqi_gi.dqi_type);
4063 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4064 struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
4065 struct buffer_head *bh = NULL;
4066 struct ocfs2_global_disk_dqinfo *gdinfo;
4067 int status = 0;
4068
4069 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
4070 lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
4071 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
4072 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
4073 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
4074 oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
4075 oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
4076 oinfo->dqi_gi.dqi_free_entry =
4077 be32_to_cpu(lvb->lvb_free_entry);
4078 } else {
4079 status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode,
4080 oinfo->dqi_giblk, &bh);
4081 if (status) {
4082 mlog_errno(status);
4083 goto bail;
4084 }
4085 gdinfo = (struct ocfs2_global_disk_dqinfo *)
4086 (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
4087 info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
4088 info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
4089 oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
4090 oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
4091 oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
4092 oinfo->dqi_gi.dqi_free_entry =
4093 le32_to_cpu(gdinfo->dqi_free_entry);
4094 brelse(bh);
4095 ocfs2_track_lock_refresh(lockres);
4096 }
4097
4098bail:
4099 return status;
4100}
4101
4102/* Lock quota info, this function expects at least shared lock on the quota file
4103 * so that we can safely refresh quota info from disk. */
4104int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
4105{
4106 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
4107 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
4108 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4109 int status = 0;
4110
4111 /* On RO devices, locking really isn't needed... */
4112 if (ocfs2_is_hard_readonly(osb)) {
4113 if (ex)
4114 status = -EROFS;
4115 goto bail;
4116 }
4117 if (ocfs2_mount_local(osb))
4118 goto bail;
4119
4120 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
4121 if (status < 0) {
4122 mlog_errno(status);
4123 goto bail;
4124 }
4125 if (!ocfs2_should_refresh_lock_res(lockres))
4126 goto bail;
4127 /* OK, we have the lock but we need to refresh the quota info */
4128 status = ocfs2_refresh_qinfo(oinfo);
4129 if (status)
4130 ocfs2_qinfo_unlock(oinfo, ex);
4131 ocfs2_complete_lock_res_refresh(lockres, status);
4132bail:
4133 return status;
4134}
4135
4136int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex)
4137{
4138 int status;
4139 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4140 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
4141 struct ocfs2_super *osb = lockres->l_priv;
4142
4143
4144 if (ocfs2_is_hard_readonly(osb))
4145 return -EROFS;
4146
4147 if (ocfs2_mount_local(osb))
4148 return 0;
4149
4150 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
4151 if (status < 0)
4152 mlog_errno(status);
4153
4154 return status;
4155}
4156
4157void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
4158{
4159 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
4160 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
4161 struct ocfs2_super *osb = lockres->l_priv;
4162
4163 if (!ocfs2_mount_local(osb))
4164 ocfs2_cluster_unlock(osb, lockres, level);
4165}
4166
4167static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
4168 struct ocfs2_lock_res *lockres)
4169{
4170 int status;
4171 struct ocfs2_unblock_ctl ctl = {0, 0,};
4172 unsigned long flags;
4173
4174 /* Our reference to the lockres in this function can be
4175 * considered valid until we remove the OCFS2_LOCK_QUEUED
4176 * flag. */
4177
4178 BUG_ON(!lockres);
4179 BUG_ON(!lockres->l_ops);
4180
4181 mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
4182
4183 /* Detect whether a lock has been marked as going away while
4184 * the downconvert thread was processing other things. A lock can
4185 * still be marked with OCFS2_LOCK_FREEING after this check,
4186 * but short circuiting here will still save us some
4187 * performance. */
4188 spin_lock_irqsave(&lockres->l_lock, flags);
4189 if (lockres->l_flags & OCFS2_LOCK_FREEING)
4190 goto unqueue;
4191 spin_unlock_irqrestore(&lockres->l_lock, flags);
4192
4193 status = ocfs2_unblock_lock(osb, lockres, &ctl);
4194 if (status < 0)
4195 mlog_errno(status);
4196
4197 spin_lock_irqsave(&lockres->l_lock, flags);
4198unqueue:
4199 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
4200 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
4201 } else
4202 ocfs2_schedule_blocked_lock(osb, lockres);
4203
4204 mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
4205 ctl.requeue ? "yes" : "no");
4206 spin_unlock_irqrestore(&lockres->l_lock, flags);
4207
4208 if (ctl.unblock_action != UNBLOCK_CONTINUE
4209 && lockres->l_ops->post_unlock)
4210 lockres->l_ops->post_unlock(osb, lockres);
4211}
4212
4213static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
4214 struct ocfs2_lock_res *lockres)
4215{
4216 unsigned long flags;
4217
4218 assert_spin_locked(&lockres->l_lock);
4219
4220 if (lockres->l_flags & OCFS2_LOCK_FREEING) {
4221 /* Do not schedule a lock for downconvert when it's on
4222 * the way to destruction - any nodes wanting access
4223 * to the resource will get it soon. */
4224 mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
4225 lockres->l_name, lockres->l_flags);
4226 return;
4227 }
4228
4229 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
4230
4231 spin_lock_irqsave(&osb->dc_task_lock, flags);
4232 if (list_empty(&lockres->l_blocked_list)) {
4233 list_add_tail(&lockres->l_blocked_list,
4234 &osb->blocked_lock_list);
4235 osb->blocked_lock_count++;
4236 }
4237 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4238}
4239
4240static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
4241{
4242 unsigned long processed;
4243 unsigned long flags;
4244 struct ocfs2_lock_res *lockres;
4245
4246 spin_lock_irqsave(&osb->dc_task_lock, flags);
4247 /* grab this early so we know to try again if a state change and
4248 * wake happens part-way through our work */
4249 osb->dc_work_sequence = osb->dc_wake_sequence;
4250
4251 processed = osb->blocked_lock_count;
4252 /*
4253 * blocked lock processing in this loop might call iput which can
4254 * remove items off osb->blocked_lock_list. Downconvert up to
4255 * 'processed' number of locks, but stop short if we had some
4256 * removed in ocfs2_mark_lockres_freeing when downconverting.
4257 */
4258 while (processed && !list_empty(&osb->blocked_lock_list)) {
4259 lockres = list_entry(osb->blocked_lock_list.next,
4260 struct ocfs2_lock_res, l_blocked_list);
4261 list_del_init(&lockres->l_blocked_list);
4262 osb->blocked_lock_count--;
4263 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4264
4265 BUG_ON(!processed);
4266 processed--;
4267
4268 ocfs2_process_blocked_lock(osb, lockres);
4269
4270 spin_lock_irqsave(&osb->dc_task_lock, flags);
4271 }
4272 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4273}
4274
4275static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
4276{
4277 int empty = 0;
4278 unsigned long flags;
4279
4280 spin_lock_irqsave(&osb->dc_task_lock, flags);
4281 if (list_empty(&osb->blocked_lock_list))
4282 empty = 1;
4283
4284 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4285 return empty;
4286}
4287
4288static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
4289{
4290 int should_wake = 0;
4291 unsigned long flags;
4292
4293 spin_lock_irqsave(&osb->dc_task_lock, flags);
4294 if (osb->dc_work_sequence != osb->dc_wake_sequence)
4295 should_wake = 1;
4296 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4297
4298 return should_wake;
4299}
4300
4301static int ocfs2_downconvert_thread(void *arg)
4302{
4303 int status = 0;
4304 struct ocfs2_super *osb = arg;
4305
4306 /* only quit once we've been asked to stop and there is no more
4307 * work available */
4308 while (!(kthread_should_stop() &&
4309 ocfs2_downconvert_thread_lists_empty(osb))) {
4310
4311 wait_event_interruptible(osb->dc_event,
4312 ocfs2_downconvert_thread_should_wake(osb) ||
4313 kthread_should_stop());
4314
4315 mlog(0, "downconvert_thread: awoken\n");
4316
4317 ocfs2_downconvert_thread_do_work(osb);
4318 }
4319
4320 osb->dc_task = NULL;
4321 return status;
4322}
4323
4324void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
4325{
4326 unsigned long flags;
4327
4328 spin_lock_irqsave(&osb->dc_task_lock, flags);
4329 /* make sure the voting thread gets a swipe at whatever changes
4330 * the caller may have made to the voting state */
4331 osb->dc_wake_sequence++;
4332 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4333 wake_up(&osb->dc_event);
4334}