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