Loading...
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#include "acl.h"
58
59#include "buffer_head_io.h"
60
61struct ocfs2_mask_waiter {
62 struct list_head mw_item;
63 int mw_status;
64 struct completion mw_complete;
65 unsigned long mw_mask;
66 unsigned long mw_goal;
67#ifdef CONFIG_OCFS2_FS_STATS
68 ktime_t mw_lock_start;
69#endif
70};
71
72static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
73static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
74static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
75static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
76
77/*
78 * Return value from ->downconvert_worker functions.
79 *
80 * These control the precise actions of ocfs2_unblock_lock()
81 * and ocfs2_process_blocked_lock()
82 *
83 */
84enum ocfs2_unblock_action {
85 UNBLOCK_CONTINUE = 0, /* Continue downconvert */
86 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire
87 * ->post_unlock callback */
88 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire
89 * ->post_unlock() callback. */
90};
91
92struct ocfs2_unblock_ctl {
93 int requeue;
94 enum ocfs2_unblock_action unblock_action;
95};
96
97/* Lockdep class keys */
98struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
99
100static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
101 int new_level);
102static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
103
104static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
105 int blocking);
106
107static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
108 int blocking);
109
110static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
111 struct ocfs2_lock_res *lockres);
112
113static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
114
115static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
116 int new_level);
117static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
118 int blocking);
119
120#define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
121
122/* This aids in debugging situations where a bad LVB might be involved. */
123static void ocfs2_dump_meta_lvb_info(u64 level,
124 const char *function,
125 unsigned int line,
126 struct ocfs2_lock_res *lockres)
127{
128 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
129
130 mlog(level, "LVB information for %s (called from %s:%u):\n",
131 lockres->l_name, function, line);
132 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n",
133 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters),
134 be32_to_cpu(lvb->lvb_igeneration));
135 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
136 (unsigned long long)be64_to_cpu(lvb->lvb_isize),
137 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
138 be16_to_cpu(lvb->lvb_imode));
139 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
140 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
141 (long long)be64_to_cpu(lvb->lvb_iatime_packed),
142 (long long)be64_to_cpu(lvb->lvb_ictime_packed),
143 (long long)be64_to_cpu(lvb->lvb_imtime_packed),
144 be32_to_cpu(lvb->lvb_iattr));
145}
146
147
148/*
149 * OCFS2 Lock Resource Operations
150 *
151 * These fine tune the behavior of the generic dlmglue locking infrastructure.
152 *
153 * The most basic of lock types can point ->l_priv to their respective
154 * struct ocfs2_super and allow the default actions to manage things.
155 *
156 * Right now, each lock type also needs to implement an init function,
157 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
158 * should be called when the lock is no longer needed (i.e., object
159 * destruction time).
160 */
161struct ocfs2_lock_res_ops {
162 /*
163 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
164 * this callback if ->l_priv is not an ocfs2_super pointer
165 */
166 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
167
168 /*
169 * Optionally called in the downconvert thread after a
170 * successful downconvert. The lockres will not be referenced
171 * after this callback is called, so it is safe to free
172 * memory, etc.
173 *
174 * The exact semantics of when this is called are controlled
175 * by ->downconvert_worker()
176 */
177 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
178
179 /*
180 * Allow a lock type to add checks to determine whether it is
181 * safe to downconvert a lock. Return 0 to re-queue the
182 * downconvert at a later time, nonzero to continue.
183 *
184 * For most locks, the default checks that there are no
185 * incompatible holders are sufficient.
186 *
187 * Called with the lockres spinlock held.
188 */
189 int (*check_downconvert)(struct ocfs2_lock_res *, int);
190
191 /*
192 * Allows a lock type to populate the lock value block. This
193 * is called on downconvert, and when we drop a lock.
194 *
195 * Locks that want to use this should set LOCK_TYPE_USES_LVB
196 * in the flags field.
197 *
198 * Called with the lockres spinlock held.
199 */
200 void (*set_lvb)(struct ocfs2_lock_res *);
201
202 /*
203 * Called from the downconvert thread when it is determined
204 * that a lock will be downconverted. This is called without
205 * any locks held so the function can do work that might
206 * schedule (syncing out data, etc).
207 *
208 * This should return any one of the ocfs2_unblock_action
209 * values, depending on what it wants the thread to do.
210 */
211 int (*downconvert_worker)(struct ocfs2_lock_res *, int);
212
213 /*
214 * LOCK_TYPE_* flags which describe the specific requirements
215 * of a lock type. Descriptions of each individual flag follow.
216 */
217 int flags;
218};
219
220/*
221 * Some locks want to "refresh" potentially stale data when a
222 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this
223 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the
224 * individual lockres l_flags member from the ast function. It is
225 * expected that the locking wrapper will clear the
226 * OCFS2_LOCK_NEEDS_REFRESH flag when done.
227 */
228#define LOCK_TYPE_REQUIRES_REFRESH 0x1
229
230/*
231 * Indicate that a lock type makes use of the lock value block. The
232 * ->set_lvb lock type callback must be defined.
233 */
234#define LOCK_TYPE_USES_LVB 0x2
235
236static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
237 .get_osb = ocfs2_get_inode_osb,
238 .flags = 0,
239};
240
241static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
242 .get_osb = ocfs2_get_inode_osb,
243 .check_downconvert = ocfs2_check_meta_downconvert,
244 .set_lvb = ocfs2_set_meta_lvb,
245 .downconvert_worker = ocfs2_data_convert_worker,
246 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
247};
248
249static struct ocfs2_lock_res_ops ocfs2_super_lops = {
250 .flags = LOCK_TYPE_REQUIRES_REFRESH,
251};
252
253static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
254 .flags = 0,
255};
256
257static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
258 .flags = 0,
259};
260
261static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
262 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
263};
264
265static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
266 .get_osb = ocfs2_get_dentry_osb,
267 .post_unlock = ocfs2_dentry_post_unlock,
268 .downconvert_worker = ocfs2_dentry_convert_worker,
269 .flags = 0,
270};
271
272static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
273 .get_osb = ocfs2_get_inode_osb,
274 .flags = 0,
275};
276
277static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
278 .get_osb = ocfs2_get_file_osb,
279 .flags = 0,
280};
281
282static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
283 .set_lvb = ocfs2_set_qinfo_lvb,
284 .get_osb = ocfs2_get_qinfo_osb,
285 .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
286};
287
288static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
289 .check_downconvert = ocfs2_check_refcount_downconvert,
290 .downconvert_worker = ocfs2_refcount_convert_worker,
291 .flags = 0,
292};
293
294static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
295{
296 return lockres->l_type == OCFS2_LOCK_TYPE_META ||
297 lockres->l_type == OCFS2_LOCK_TYPE_RW ||
298 lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
299}
300
301static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb)
302{
303 return container_of(lksb, struct ocfs2_lock_res, l_lksb);
304}
305
306static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
307{
308 BUG_ON(!ocfs2_is_inode_lock(lockres));
309
310 return (struct inode *) lockres->l_priv;
311}
312
313static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
314{
315 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
316
317 return (struct ocfs2_dentry_lock *)lockres->l_priv;
318}
319
320static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
321{
322 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
323
324 return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
325}
326
327static inline struct ocfs2_refcount_tree *
328ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res)
329{
330 return container_of(res, struct ocfs2_refcount_tree, rf_lockres);
331}
332
333static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
334{
335 if (lockres->l_ops->get_osb)
336 return lockres->l_ops->get_osb(lockres);
337
338 return (struct ocfs2_super *)lockres->l_priv;
339}
340
341static int ocfs2_lock_create(struct ocfs2_super *osb,
342 struct ocfs2_lock_res *lockres,
343 int level,
344 u32 dlm_flags);
345static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
346 int wanted);
347static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
348 struct ocfs2_lock_res *lockres,
349 int level, unsigned long caller_ip);
350static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb,
351 struct ocfs2_lock_res *lockres,
352 int level)
353{
354 __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_);
355}
356
357static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
358static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
359static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
360static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
361static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
362 struct ocfs2_lock_res *lockres);
363static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
364 int convert);
365#define ocfs2_log_dlm_error(_func, _err, _lockres) do { \
366 if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \
367 mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \
368 _err, _func, _lockres->l_name); \
369 else \
370 mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \
371 _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \
372 (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \
373} while (0)
374static int ocfs2_downconvert_thread(void *arg);
375static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
376 struct ocfs2_lock_res *lockres);
377static int ocfs2_inode_lock_update(struct inode *inode,
378 struct buffer_head **bh);
379static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
380static inline int ocfs2_highest_compat_lock_level(int level);
381static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
382 int new_level);
383static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
384 struct ocfs2_lock_res *lockres,
385 int new_level,
386 int lvb,
387 unsigned int generation);
388static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
389 struct ocfs2_lock_res *lockres);
390static int ocfs2_cancel_convert(struct ocfs2_super *osb,
391 struct ocfs2_lock_res *lockres);
392
393
394static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
395 u64 blkno,
396 u32 generation,
397 char *name)
398{
399 int len;
400
401 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
402
403 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
404 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
405 (long long)blkno, generation);
406
407 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
408
409 mlog(0, "built lock resource with name: %s\n", name);
410}
411
412static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
413
414static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
415 struct ocfs2_dlm_debug *dlm_debug)
416{
417 mlog(0, "Add tracking for lockres %s\n", res->l_name);
418
419 spin_lock(&ocfs2_dlm_tracking_lock);
420 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
421 spin_unlock(&ocfs2_dlm_tracking_lock);
422}
423
424static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
425{
426 spin_lock(&ocfs2_dlm_tracking_lock);
427 if (!list_empty(&res->l_debug_list))
428 list_del_init(&res->l_debug_list);
429 spin_unlock(&ocfs2_dlm_tracking_lock);
430}
431
432#ifdef CONFIG_OCFS2_FS_STATS
433static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
434{
435 res->l_lock_refresh = 0;
436 memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats));
437 memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats));
438}
439
440static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level,
441 struct ocfs2_mask_waiter *mw, int ret)
442{
443 u32 usec;
444 ktime_t kt;
445 struct ocfs2_lock_stats *stats;
446
447 if (level == LKM_PRMODE)
448 stats = &res->l_lock_prmode;
449 else if (level == LKM_EXMODE)
450 stats = &res->l_lock_exmode;
451 else
452 return;
453
454 kt = ktime_sub(ktime_get(), mw->mw_lock_start);
455 usec = ktime_to_us(kt);
456
457 stats->ls_gets++;
458 stats->ls_total += ktime_to_ns(kt);
459 /* overflow */
460 if (unlikely(stats->ls_gets == 0)) {
461 stats->ls_gets++;
462 stats->ls_total = ktime_to_ns(kt);
463 }
464
465 if (stats->ls_max < usec)
466 stats->ls_max = usec;
467
468 if (ret)
469 stats->ls_fail++;
470}
471
472static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
473{
474 lockres->l_lock_refresh++;
475}
476
477static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
478{
479 mw->mw_lock_start = ktime_get();
480}
481#else
482static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
483{
484}
485static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res,
486 int level, struct ocfs2_mask_waiter *mw, int ret)
487{
488}
489static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
490{
491}
492static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
493{
494}
495#endif
496
497static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
498 struct ocfs2_lock_res *res,
499 enum ocfs2_lock_type type,
500 struct ocfs2_lock_res_ops *ops,
501 void *priv)
502{
503 res->l_type = type;
504 res->l_ops = ops;
505 res->l_priv = priv;
506
507 res->l_level = DLM_LOCK_IV;
508 res->l_requested = DLM_LOCK_IV;
509 res->l_blocking = DLM_LOCK_IV;
510 res->l_action = OCFS2_AST_INVALID;
511 res->l_unlock_action = OCFS2_UNLOCK_INVALID;
512
513 res->l_flags = OCFS2_LOCK_INITIALIZED;
514
515 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
516
517 ocfs2_init_lock_stats(res);
518#ifdef CONFIG_DEBUG_LOCK_ALLOC
519 if (type != OCFS2_LOCK_TYPE_OPEN)
520 lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type],
521 &lockdep_keys[type], 0);
522 else
523 res->l_lockdep_map.key = NULL;
524#endif
525}
526
527void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
528{
529 /* This also clears out the lock status block */
530 memset(res, 0, sizeof(struct ocfs2_lock_res));
531 spin_lock_init(&res->l_lock);
532 init_waitqueue_head(&res->l_event);
533 INIT_LIST_HEAD(&res->l_blocked_list);
534 INIT_LIST_HEAD(&res->l_mask_waiters);
535}
536
537void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
538 enum ocfs2_lock_type type,
539 unsigned int generation,
540 struct inode *inode)
541{
542 struct ocfs2_lock_res_ops *ops;
543
544 switch(type) {
545 case OCFS2_LOCK_TYPE_RW:
546 ops = &ocfs2_inode_rw_lops;
547 break;
548 case OCFS2_LOCK_TYPE_META:
549 ops = &ocfs2_inode_inode_lops;
550 break;
551 case OCFS2_LOCK_TYPE_OPEN:
552 ops = &ocfs2_inode_open_lops;
553 break;
554 default:
555 mlog_bug_on_msg(1, "type: %d\n", type);
556 ops = NULL; /* thanks, gcc */
557 break;
558 };
559
560 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
561 generation, res->l_name);
562 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
563}
564
565static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
566{
567 struct inode *inode = ocfs2_lock_res_inode(lockres);
568
569 return OCFS2_SB(inode->i_sb);
570}
571
572static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
573{
574 struct ocfs2_mem_dqinfo *info = lockres->l_priv;
575
576 return OCFS2_SB(info->dqi_gi.dqi_sb);
577}
578
579static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
580{
581 struct ocfs2_file_private *fp = lockres->l_priv;
582
583 return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
584}
585
586static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
587{
588 __be64 inode_blkno_be;
589
590 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
591 sizeof(__be64));
592
593 return be64_to_cpu(inode_blkno_be);
594}
595
596static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
597{
598 struct ocfs2_dentry_lock *dl = lockres->l_priv;
599
600 return OCFS2_SB(dl->dl_inode->i_sb);
601}
602
603void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
604 u64 parent, struct inode *inode)
605{
606 int len;
607 u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
608 __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
609 struct ocfs2_lock_res *lockres = &dl->dl_lockres;
610
611 ocfs2_lock_res_init_once(lockres);
612
613 /*
614 * Unfortunately, the standard lock naming scheme won't work
615 * here because we have two 16 byte values to use. Instead,
616 * we'll stuff the inode number as a binary value. We still
617 * want error prints to show something without garbling the
618 * display, so drop a null byte in there before the inode
619 * number. A future version of OCFS2 will likely use all
620 * binary lock names. The stringified names have been a
621 * tremendous aid in debugging, but now that the debugfs
622 * interface exists, we can mangle things there if need be.
623 *
624 * NOTE: We also drop the standard "pad" value (the total lock
625 * name size stays the same though - the last part is all
626 * zeros due to the memset in ocfs2_lock_res_init_once()
627 */
628 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
629 "%c%016llx",
630 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
631 (long long)parent);
632
633 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
634
635 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
636 sizeof(__be64));
637
638 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
639 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
640 dl);
641}
642
643static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
644 struct ocfs2_super *osb)
645{
646 /* Superblock lockres doesn't come from a slab so we call init
647 * once on it manually. */
648 ocfs2_lock_res_init_once(res);
649 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
650 0, res->l_name);
651 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
652 &ocfs2_super_lops, osb);
653}
654
655static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
656 struct ocfs2_super *osb)
657{
658 /* Rename lockres doesn't come from a slab so we call init
659 * once on it manually. */
660 ocfs2_lock_res_init_once(res);
661 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
662 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
663 &ocfs2_rename_lops, osb);
664}
665
666static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
667 struct ocfs2_super *osb)
668{
669 /* nfs_sync lockres doesn't come from a slab so we call init
670 * once on it manually. */
671 ocfs2_lock_res_init_once(res);
672 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
673 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
674 &ocfs2_nfs_sync_lops, osb);
675}
676
677static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
678 struct ocfs2_super *osb)
679{
680 ocfs2_lock_res_init_once(res);
681 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
682 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
683 &ocfs2_orphan_scan_lops, osb);
684}
685
686void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
687 struct ocfs2_file_private *fp)
688{
689 struct inode *inode = fp->fp_file->f_mapping->host;
690 struct ocfs2_inode_info *oi = OCFS2_I(inode);
691
692 ocfs2_lock_res_init_once(lockres);
693 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
694 inode->i_generation, lockres->l_name);
695 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
696 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
697 fp);
698 lockres->l_flags |= OCFS2_LOCK_NOCACHE;
699}
700
701void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
702 struct ocfs2_mem_dqinfo *info)
703{
704 ocfs2_lock_res_init_once(lockres);
705 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
706 0, lockres->l_name);
707 ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
708 OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
709 info);
710}
711
712void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
713 struct ocfs2_super *osb, u64 ref_blkno,
714 unsigned int generation)
715{
716 ocfs2_lock_res_init_once(lockres);
717 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno,
718 generation, lockres->l_name);
719 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT,
720 &ocfs2_refcount_block_lops, osb);
721}
722
723void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
724{
725 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
726 return;
727
728 ocfs2_remove_lockres_tracking(res);
729
730 mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
731 "Lockres %s is on the blocked list\n",
732 res->l_name);
733 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
734 "Lockres %s has mask waiters pending\n",
735 res->l_name);
736 mlog_bug_on_msg(spin_is_locked(&res->l_lock),
737 "Lockres %s is locked\n",
738 res->l_name);
739 mlog_bug_on_msg(res->l_ro_holders,
740 "Lockres %s has %u ro holders\n",
741 res->l_name, res->l_ro_holders);
742 mlog_bug_on_msg(res->l_ex_holders,
743 "Lockres %s has %u ex holders\n",
744 res->l_name, res->l_ex_holders);
745
746 /* Need to clear out the lock status block for the dlm */
747 memset(&res->l_lksb, 0, sizeof(res->l_lksb));
748
749 res->l_flags = 0UL;
750}
751
752static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
753 int level)
754{
755 BUG_ON(!lockres);
756
757 switch(level) {
758 case DLM_LOCK_EX:
759 lockres->l_ex_holders++;
760 break;
761 case DLM_LOCK_PR:
762 lockres->l_ro_holders++;
763 break;
764 default:
765 BUG();
766 }
767}
768
769static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
770 int level)
771{
772 BUG_ON(!lockres);
773
774 switch(level) {
775 case DLM_LOCK_EX:
776 BUG_ON(!lockres->l_ex_holders);
777 lockres->l_ex_holders--;
778 break;
779 case DLM_LOCK_PR:
780 BUG_ON(!lockres->l_ro_holders);
781 lockres->l_ro_holders--;
782 break;
783 default:
784 BUG();
785 }
786}
787
788/* WARNING: This function lives in a world where the only three lock
789 * levels are EX, PR, and NL. It *will* have to be adjusted when more
790 * lock types are added. */
791static inline int ocfs2_highest_compat_lock_level(int level)
792{
793 int new_level = DLM_LOCK_EX;
794
795 if (level == DLM_LOCK_EX)
796 new_level = DLM_LOCK_NL;
797 else if (level == DLM_LOCK_PR)
798 new_level = DLM_LOCK_PR;
799 return new_level;
800}
801
802static void lockres_set_flags(struct ocfs2_lock_res *lockres,
803 unsigned long newflags)
804{
805 struct ocfs2_mask_waiter *mw, *tmp;
806
807 assert_spin_locked(&lockres->l_lock);
808
809 lockres->l_flags = newflags;
810
811 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
812 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
813 continue;
814
815 list_del_init(&mw->mw_item);
816 mw->mw_status = 0;
817 complete(&mw->mw_complete);
818 }
819}
820static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
821{
822 lockres_set_flags(lockres, lockres->l_flags | or);
823}
824static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
825 unsigned long clear)
826{
827 lockres_set_flags(lockres, lockres->l_flags & ~clear);
828}
829
830static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
831{
832 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
833 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
834 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
835 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
836
837 lockres->l_level = lockres->l_requested;
838 if (lockres->l_level <=
839 ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
840 lockres->l_blocking = DLM_LOCK_NL;
841 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
842 }
843 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
844}
845
846static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
847{
848 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
849 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
850
851 /* Convert from RO to EX doesn't really need anything as our
852 * information is already up to data. Convert from NL to
853 * *anything* however should mark ourselves as needing an
854 * update */
855 if (lockres->l_level == DLM_LOCK_NL &&
856 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
857 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
858
859 lockres->l_level = lockres->l_requested;
860
861 /*
862 * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing
863 * the OCFS2_LOCK_BUSY flag to prevent the dc thread from
864 * downconverting the lock before the upconvert has fully completed.
865 * Do not prevent the dc thread from downconverting if NONBLOCK lock
866 * had already returned.
867 */
868 if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED))
869 lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
870 else
871 lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED);
872
873 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
874}
875
876static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
877{
878 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
879 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
880
881 if (lockres->l_requested > DLM_LOCK_NL &&
882 !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
883 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
884 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
885
886 lockres->l_level = lockres->l_requested;
887 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
888 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
889}
890
891static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
892 int level)
893{
894 int needs_downconvert = 0;
895
896 assert_spin_locked(&lockres->l_lock);
897
898 if (level > lockres->l_blocking) {
899 /* only schedule a downconvert if we haven't already scheduled
900 * one that goes low enough to satisfy the level we're
901 * blocking. this also catches the case where we get
902 * duplicate BASTs */
903 if (ocfs2_highest_compat_lock_level(level) <
904 ocfs2_highest_compat_lock_level(lockres->l_blocking))
905 needs_downconvert = 1;
906
907 lockres->l_blocking = level;
908 }
909
910 mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
911 lockres->l_name, level, lockres->l_level, lockres->l_blocking,
912 needs_downconvert);
913
914 if (needs_downconvert)
915 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
916 mlog(0, "needs_downconvert = %d\n", needs_downconvert);
917 return needs_downconvert;
918}
919
920/*
921 * OCFS2_LOCK_PENDING and l_pending_gen.
922 *
923 * Why does OCFS2_LOCK_PENDING exist? To close a race between setting
924 * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock()
925 * for more details on the race.
926 *
927 * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces
928 * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock()
929 * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear
930 * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns,
931 * the caller is going to try to clear PENDING again. If nothing else is
932 * happening, __lockres_clear_pending() sees PENDING is unset and does
933 * nothing.
934 *
935 * But what if another path (eg downconvert thread) has just started a
936 * new locking action? The other path has re-set PENDING. Our path
937 * cannot clear PENDING, because that will re-open the original race
938 * window.
939 *
940 * [Example]
941 *
942 * ocfs2_meta_lock()
943 * ocfs2_cluster_lock()
944 * set BUSY
945 * set PENDING
946 * drop l_lock
947 * ocfs2_dlm_lock()
948 * ocfs2_locking_ast() ocfs2_downconvert_thread()
949 * clear PENDING ocfs2_unblock_lock()
950 * take_l_lock
951 * !BUSY
952 * ocfs2_prepare_downconvert()
953 * set BUSY
954 * set PENDING
955 * drop l_lock
956 * take l_lock
957 * clear PENDING
958 * drop l_lock
959 * <window>
960 * ocfs2_dlm_lock()
961 *
962 * So as you can see, we now have a window where l_lock is not held,
963 * PENDING is not set, and ocfs2_dlm_lock() has not been called.
964 *
965 * The core problem is that ocfs2_cluster_lock() has cleared the PENDING
966 * set by ocfs2_prepare_downconvert(). That wasn't nice.
967 *
968 * To solve this we introduce l_pending_gen. A call to
969 * lockres_clear_pending() will only do so when it is passed a generation
970 * number that matches the lockres. lockres_set_pending() will return the
971 * current generation number. When ocfs2_cluster_lock() goes to clear
972 * PENDING, it passes the generation it got from set_pending(). In our
973 * example above, the generation numbers will *not* match. Thus,
974 * ocfs2_cluster_lock() will not clear the PENDING set by
975 * ocfs2_prepare_downconvert().
976 */
977
978/* Unlocked version for ocfs2_locking_ast() */
979static void __lockres_clear_pending(struct ocfs2_lock_res *lockres,
980 unsigned int generation,
981 struct ocfs2_super *osb)
982{
983 assert_spin_locked(&lockres->l_lock);
984
985 /*
986 * The ast and locking functions can race us here. The winner
987 * will clear pending, the loser will not.
988 */
989 if (!(lockres->l_flags & OCFS2_LOCK_PENDING) ||
990 (lockres->l_pending_gen != generation))
991 return;
992
993 lockres_clear_flags(lockres, OCFS2_LOCK_PENDING);
994 lockres->l_pending_gen++;
995
996 /*
997 * The downconvert thread may have skipped us because we
998 * were PENDING. Wake it up.
999 */
1000 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1001 ocfs2_wake_downconvert_thread(osb);
1002}
1003
1004/* Locked version for callers of ocfs2_dlm_lock() */
1005static void lockres_clear_pending(struct ocfs2_lock_res *lockres,
1006 unsigned int generation,
1007 struct ocfs2_super *osb)
1008{
1009 unsigned long flags;
1010
1011 spin_lock_irqsave(&lockres->l_lock, flags);
1012 __lockres_clear_pending(lockres, generation, osb);
1013 spin_unlock_irqrestore(&lockres->l_lock, flags);
1014}
1015
1016static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
1017{
1018 assert_spin_locked(&lockres->l_lock);
1019 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
1020
1021 lockres_or_flags(lockres, OCFS2_LOCK_PENDING);
1022
1023 return lockres->l_pending_gen;
1024}
1025
1026static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
1027{
1028 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1029 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1030 int needs_downconvert;
1031 unsigned long flags;
1032
1033 BUG_ON(level <= DLM_LOCK_NL);
1034
1035 mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
1036 "type %s\n", lockres->l_name, level, lockres->l_level,
1037 ocfs2_lock_type_string(lockres->l_type));
1038
1039 /*
1040 * We can skip the bast for locks which don't enable caching -
1041 * they'll be dropped at the earliest possible time anyway.
1042 */
1043 if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
1044 return;
1045
1046 spin_lock_irqsave(&lockres->l_lock, flags);
1047 needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
1048 if (needs_downconvert)
1049 ocfs2_schedule_blocked_lock(osb, lockres);
1050 spin_unlock_irqrestore(&lockres->l_lock, flags);
1051
1052 wake_up(&lockres->l_event);
1053
1054 ocfs2_wake_downconvert_thread(osb);
1055}
1056
1057static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
1058{
1059 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1060 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1061 unsigned long flags;
1062 int status;
1063
1064 spin_lock_irqsave(&lockres->l_lock, flags);
1065
1066 status = ocfs2_dlm_lock_status(&lockres->l_lksb);
1067
1068 if (status == -EAGAIN) {
1069 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1070 goto out;
1071 }
1072
1073 if (status) {
1074 mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n",
1075 lockres->l_name, status);
1076 spin_unlock_irqrestore(&lockres->l_lock, flags);
1077 return;
1078 }
1079
1080 mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
1081 "level %d => %d\n", lockres->l_name, lockres->l_action,
1082 lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
1083
1084 switch(lockres->l_action) {
1085 case OCFS2_AST_ATTACH:
1086 ocfs2_generic_handle_attach_action(lockres);
1087 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
1088 break;
1089 case OCFS2_AST_CONVERT:
1090 ocfs2_generic_handle_convert_action(lockres);
1091 break;
1092 case OCFS2_AST_DOWNCONVERT:
1093 ocfs2_generic_handle_downconvert_action(lockres);
1094 break;
1095 default:
1096 mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
1097 "flags 0x%lx, unlock: %u\n",
1098 lockres->l_name, lockres->l_action, lockres->l_flags,
1099 lockres->l_unlock_action);
1100 BUG();
1101 }
1102out:
1103 /* set it to something invalid so if we get called again we
1104 * can catch it. */
1105 lockres->l_action = OCFS2_AST_INVALID;
1106
1107 /* Did we try to cancel this lock? Clear that state */
1108 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT)
1109 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1110
1111 /*
1112 * We may have beaten the locking functions here. We certainly
1113 * know that dlm_lock() has been called :-)
1114 * Because we can't have two lock calls in flight at once, we
1115 * can use lockres->l_pending_gen.
1116 */
1117 __lockres_clear_pending(lockres, lockres->l_pending_gen, osb);
1118
1119 wake_up(&lockres->l_event);
1120 spin_unlock_irqrestore(&lockres->l_lock, flags);
1121}
1122
1123static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
1124{
1125 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
1126 unsigned long flags;
1127
1128 mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
1129 lockres->l_name, lockres->l_unlock_action);
1130
1131 spin_lock_irqsave(&lockres->l_lock, flags);
1132 if (error) {
1133 mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
1134 "unlock_action %d\n", error, lockres->l_name,
1135 lockres->l_unlock_action);
1136 spin_unlock_irqrestore(&lockres->l_lock, flags);
1137 return;
1138 }
1139
1140 switch(lockres->l_unlock_action) {
1141 case OCFS2_UNLOCK_CANCEL_CONVERT:
1142 mlog(0, "Cancel convert success for %s\n", lockres->l_name);
1143 lockres->l_action = OCFS2_AST_INVALID;
1144 /* Downconvert thread may have requeued this lock, we
1145 * need to wake it. */
1146 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
1147 ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
1148 break;
1149 case OCFS2_UNLOCK_DROP_LOCK:
1150 lockres->l_level = DLM_LOCK_IV;
1151 break;
1152 default:
1153 BUG();
1154 }
1155
1156 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1157 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1158 wake_up(&lockres->l_event);
1159 spin_unlock_irqrestore(&lockres->l_lock, flags);
1160}
1161
1162/*
1163 * This is the filesystem locking protocol. It provides the lock handling
1164 * hooks for the underlying DLM. It has a maximum version number.
1165 * The version number allows interoperability with systems running at
1166 * the same major number and an equal or smaller minor number.
1167 *
1168 * Whenever the filesystem does new things with locks (adds or removes a
1169 * lock, orders them differently, does different things underneath a lock),
1170 * the version must be changed. The protocol is negotiated when joining
1171 * the dlm domain. A node may join the domain if its major version is
1172 * identical to all other nodes and its minor version is greater than
1173 * or equal to all other nodes. When its minor version is greater than
1174 * the other nodes, it will run at the minor version specified by the
1175 * other nodes.
1176 *
1177 * If a locking change is made that will not be compatible with older
1178 * versions, the major number must be increased and the minor version set
1179 * to zero. If a change merely adds a behavior that can be disabled when
1180 * speaking to older versions, the minor version must be increased. If a
1181 * change adds a fully backwards compatible change (eg, LVB changes that
1182 * are just ignored by older versions), the version does not need to be
1183 * updated.
1184 */
1185static struct ocfs2_locking_protocol lproto = {
1186 .lp_max_version = {
1187 .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
1188 .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
1189 },
1190 .lp_lock_ast = ocfs2_locking_ast,
1191 .lp_blocking_ast = ocfs2_blocking_ast,
1192 .lp_unlock_ast = ocfs2_unlock_ast,
1193};
1194
1195void ocfs2_set_locking_protocol(void)
1196{
1197 ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
1198}
1199
1200static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
1201 int convert)
1202{
1203 unsigned long flags;
1204
1205 spin_lock_irqsave(&lockres->l_lock, flags);
1206 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
1207 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1208 if (convert)
1209 lockres->l_action = OCFS2_AST_INVALID;
1210 else
1211 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
1212 spin_unlock_irqrestore(&lockres->l_lock, flags);
1213
1214 wake_up(&lockres->l_event);
1215}
1216
1217/* Note: If we detect another process working on the lock (i.e.,
1218 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
1219 * to do the right thing in that case.
1220 */
1221static int ocfs2_lock_create(struct ocfs2_super *osb,
1222 struct ocfs2_lock_res *lockres,
1223 int level,
1224 u32 dlm_flags)
1225{
1226 int ret = 0;
1227 unsigned long flags;
1228 unsigned int gen;
1229
1230 mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level,
1231 dlm_flags);
1232
1233 spin_lock_irqsave(&lockres->l_lock, flags);
1234 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
1235 (lockres->l_flags & OCFS2_LOCK_BUSY)) {
1236 spin_unlock_irqrestore(&lockres->l_lock, flags);
1237 goto bail;
1238 }
1239
1240 lockres->l_action = OCFS2_AST_ATTACH;
1241 lockres->l_requested = level;
1242 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1243 gen = lockres_set_pending(lockres);
1244 spin_unlock_irqrestore(&lockres->l_lock, flags);
1245
1246 ret = ocfs2_dlm_lock(osb->cconn,
1247 level,
1248 &lockres->l_lksb,
1249 dlm_flags,
1250 lockres->l_name,
1251 OCFS2_LOCK_ID_MAX_LEN - 1);
1252 lockres_clear_pending(lockres, gen, osb);
1253 if (ret) {
1254 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
1255 ocfs2_recover_from_dlm_error(lockres, 1);
1256 }
1257
1258 mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name);
1259
1260bail:
1261 return ret;
1262}
1263
1264static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
1265 int flag)
1266{
1267 unsigned long flags;
1268 int ret;
1269
1270 spin_lock_irqsave(&lockres->l_lock, flags);
1271 ret = lockres->l_flags & flag;
1272 spin_unlock_irqrestore(&lockres->l_lock, flags);
1273
1274 return ret;
1275}
1276
1277static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
1278
1279{
1280 wait_event(lockres->l_event,
1281 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
1282}
1283
1284static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
1285
1286{
1287 wait_event(lockres->l_event,
1288 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
1289}
1290
1291/* predict what lock level we'll be dropping down to on behalf
1292 * of another node, and return true if the currently wanted
1293 * level will be compatible with it. */
1294static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
1295 int wanted)
1296{
1297 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
1298
1299 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
1300}
1301
1302static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
1303{
1304 INIT_LIST_HEAD(&mw->mw_item);
1305 init_completion(&mw->mw_complete);
1306 ocfs2_init_start_time(mw);
1307}
1308
1309static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
1310{
1311 wait_for_completion(&mw->mw_complete);
1312 /* Re-arm the completion in case we want to wait on it again */
1313 reinit_completion(&mw->mw_complete);
1314 return mw->mw_status;
1315}
1316
1317static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
1318 struct ocfs2_mask_waiter *mw,
1319 unsigned long mask,
1320 unsigned long goal)
1321{
1322 BUG_ON(!list_empty(&mw->mw_item));
1323
1324 assert_spin_locked(&lockres->l_lock);
1325
1326 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
1327 mw->mw_mask = mask;
1328 mw->mw_goal = goal;
1329}
1330
1331/* returns 0 if the mw that was removed was already satisfied, -EBUSY
1332 * if the mask still hadn't reached its goal */
1333static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1334 struct ocfs2_mask_waiter *mw)
1335{
1336 int ret = 0;
1337
1338 assert_spin_locked(&lockres->l_lock);
1339 if (!list_empty(&mw->mw_item)) {
1340 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
1341 ret = -EBUSY;
1342
1343 list_del_init(&mw->mw_item);
1344 init_completion(&mw->mw_complete);
1345 }
1346
1347 return ret;
1348}
1349
1350static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
1351 struct ocfs2_mask_waiter *mw)
1352{
1353 unsigned long flags;
1354 int ret = 0;
1355
1356 spin_lock_irqsave(&lockres->l_lock, flags);
1357 ret = __lockres_remove_mask_waiter(lockres, mw);
1358 spin_unlock_irqrestore(&lockres->l_lock, flags);
1359
1360 return ret;
1361
1362}
1363
1364static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
1365 struct ocfs2_lock_res *lockres)
1366{
1367 int ret;
1368
1369 ret = wait_for_completion_interruptible(&mw->mw_complete);
1370 if (ret)
1371 lockres_remove_mask_waiter(lockres, mw);
1372 else
1373 ret = mw->mw_status;
1374 /* Re-arm the completion in case we want to wait on it again */
1375 reinit_completion(&mw->mw_complete);
1376 return ret;
1377}
1378
1379static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
1380 struct ocfs2_lock_res *lockres,
1381 int level,
1382 u32 lkm_flags,
1383 int arg_flags,
1384 int l_subclass,
1385 unsigned long caller_ip)
1386{
1387 struct ocfs2_mask_waiter mw;
1388 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
1389 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
1390 unsigned long flags;
1391 unsigned int gen;
1392 int noqueue_attempted = 0;
1393 int dlm_locked = 0;
1394 int kick_dc = 0;
1395
1396 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
1397 mlog_errno(-EINVAL);
1398 return -EINVAL;
1399 }
1400
1401 ocfs2_init_mask_waiter(&mw);
1402
1403 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
1404 lkm_flags |= DLM_LKF_VALBLK;
1405
1406again:
1407 wait = 0;
1408
1409 spin_lock_irqsave(&lockres->l_lock, flags);
1410
1411 if (catch_signals && signal_pending(current)) {
1412 ret = -ERESTARTSYS;
1413 goto unlock;
1414 }
1415
1416 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
1417 "Cluster lock called on freeing lockres %s! flags "
1418 "0x%lx\n", lockres->l_name, lockres->l_flags);
1419
1420 /* We only compare against the currently granted level
1421 * here. If the lock is blocked waiting on a downconvert,
1422 * we'll get caught below. */
1423 if (lockres->l_flags & OCFS2_LOCK_BUSY &&
1424 level > lockres->l_level) {
1425 /* is someone sitting in dlm_lock? If so, wait on
1426 * them. */
1427 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1428 wait = 1;
1429 goto unlock;
1430 }
1431
1432 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) {
1433 /*
1434 * We've upconverted. If the lock now has a level we can
1435 * work with, we take it. If, however, the lock is not at the
1436 * required level, we go thru the full cycle. One way this could
1437 * happen is if a process requesting an upconvert to PR is
1438 * closely followed by another requesting upconvert to an EX.
1439 * If the process requesting EX lands here, we want it to
1440 * continue attempting to upconvert and let the process
1441 * requesting PR take the lock.
1442 * If multiple processes request upconvert to PR, the first one
1443 * here will take the lock. The others will have to go thru the
1444 * OCFS2_LOCK_BLOCKED check to ensure that there is no pending
1445 * downconvert request.
1446 */
1447 if (level <= lockres->l_level)
1448 goto update_holders;
1449 }
1450
1451 if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
1452 !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
1453 /* is the lock is currently blocked on behalf of
1454 * another node */
1455 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
1456 wait = 1;
1457 goto unlock;
1458 }
1459
1460 if (level > lockres->l_level) {
1461 if (noqueue_attempted > 0) {
1462 ret = -EAGAIN;
1463 goto unlock;
1464 }
1465 if (lkm_flags & DLM_LKF_NOQUEUE)
1466 noqueue_attempted = 1;
1467
1468 if (lockres->l_action != OCFS2_AST_INVALID)
1469 mlog(ML_ERROR, "lockres %s has action %u pending\n",
1470 lockres->l_name, lockres->l_action);
1471
1472 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1473 lockres->l_action = OCFS2_AST_ATTACH;
1474 lkm_flags &= ~DLM_LKF_CONVERT;
1475 } else {
1476 lockres->l_action = OCFS2_AST_CONVERT;
1477 lkm_flags |= DLM_LKF_CONVERT;
1478 }
1479
1480 lockres->l_requested = level;
1481 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1482 gen = lockres_set_pending(lockres);
1483 spin_unlock_irqrestore(&lockres->l_lock, flags);
1484
1485 BUG_ON(level == DLM_LOCK_IV);
1486 BUG_ON(level == DLM_LOCK_NL);
1487
1488 mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
1489 lockres->l_name, lockres->l_level, level);
1490
1491 /* call dlm_lock to upgrade lock now */
1492 ret = ocfs2_dlm_lock(osb->cconn,
1493 level,
1494 &lockres->l_lksb,
1495 lkm_flags,
1496 lockres->l_name,
1497 OCFS2_LOCK_ID_MAX_LEN - 1);
1498 lockres_clear_pending(lockres, gen, osb);
1499 if (ret) {
1500 if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
1501 (ret != -EAGAIN)) {
1502 ocfs2_log_dlm_error("ocfs2_dlm_lock",
1503 ret, lockres);
1504 }
1505 ocfs2_recover_from_dlm_error(lockres, 1);
1506 goto out;
1507 }
1508 dlm_locked = 1;
1509
1510 mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n",
1511 lockres->l_name);
1512
1513 /* At this point we've gone inside the dlm and need to
1514 * complete our work regardless. */
1515 catch_signals = 0;
1516
1517 /* wait for busy to clear and carry on */
1518 goto again;
1519 }
1520
1521update_holders:
1522 /* Ok, if we get here then we're good to go. */
1523 ocfs2_inc_holders(lockres, level);
1524
1525 ret = 0;
1526unlock:
1527 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
1528
1529 /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */
1530 kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED);
1531
1532 spin_unlock_irqrestore(&lockres->l_lock, flags);
1533 if (kick_dc)
1534 ocfs2_wake_downconvert_thread(osb);
1535out:
1536 /*
1537 * This is helping work around a lock inversion between the page lock
1538 * and dlm locks. One path holds the page lock while calling aops
1539 * which block acquiring dlm locks. The voting thread holds dlm
1540 * locks while acquiring page locks while down converting data locks.
1541 * This block is helping an aop path notice the inversion and back
1542 * off to unlock its page lock before trying the dlm lock again.
1543 */
1544 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
1545 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
1546 wait = 0;
1547 spin_lock_irqsave(&lockres->l_lock, flags);
1548 if (__lockres_remove_mask_waiter(lockres, &mw)) {
1549 if (dlm_locked)
1550 lockres_or_flags(lockres,
1551 OCFS2_LOCK_NONBLOCK_FINISHED);
1552 spin_unlock_irqrestore(&lockres->l_lock, flags);
1553 ret = -EAGAIN;
1554 } else {
1555 spin_unlock_irqrestore(&lockres->l_lock, flags);
1556 goto again;
1557 }
1558 }
1559 if (wait) {
1560 ret = ocfs2_wait_for_mask(&mw);
1561 if (ret == 0)
1562 goto again;
1563 mlog_errno(ret);
1564 }
1565 ocfs2_update_lock_stats(lockres, level, &mw, ret);
1566
1567#ifdef CONFIG_DEBUG_LOCK_ALLOC
1568 if (!ret && lockres->l_lockdep_map.key != NULL) {
1569 if (level == DLM_LOCK_PR)
1570 rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass,
1571 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1572 caller_ip);
1573 else
1574 rwsem_acquire(&lockres->l_lockdep_map, l_subclass,
1575 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
1576 caller_ip);
1577 }
1578#endif
1579 return ret;
1580}
1581
1582static inline int ocfs2_cluster_lock(struct ocfs2_super *osb,
1583 struct ocfs2_lock_res *lockres,
1584 int level,
1585 u32 lkm_flags,
1586 int arg_flags)
1587{
1588 return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags,
1589 0, _RET_IP_);
1590}
1591
1592
1593static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
1594 struct ocfs2_lock_res *lockres,
1595 int level,
1596 unsigned long caller_ip)
1597{
1598 unsigned long flags;
1599
1600 spin_lock_irqsave(&lockres->l_lock, flags);
1601 ocfs2_dec_holders(lockres, level);
1602 ocfs2_downconvert_on_unlock(osb, lockres);
1603 spin_unlock_irqrestore(&lockres->l_lock, flags);
1604#ifdef CONFIG_DEBUG_LOCK_ALLOC
1605 if (lockres->l_lockdep_map.key != NULL)
1606 rwsem_release(&lockres->l_lockdep_map, 1, caller_ip);
1607#endif
1608}
1609
1610static int ocfs2_create_new_lock(struct ocfs2_super *osb,
1611 struct ocfs2_lock_res *lockres,
1612 int ex,
1613 int local)
1614{
1615 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1616 unsigned long flags;
1617 u32 lkm_flags = local ? DLM_LKF_LOCAL : 0;
1618
1619 spin_lock_irqsave(&lockres->l_lock, flags);
1620 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
1621 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
1622 spin_unlock_irqrestore(&lockres->l_lock, flags);
1623
1624 return ocfs2_lock_create(osb, lockres, level, lkm_flags);
1625}
1626
1627/* Grants us an EX lock on the data and metadata resources, skipping
1628 * the normal cluster directory lookup. Use this ONLY on newly created
1629 * inodes which other nodes can't possibly see, and which haven't been
1630 * hashed in the inode hash yet. This can give us a good performance
1631 * increase as it'll skip the network broadcast normally associated
1632 * with creating a new lock resource. */
1633int ocfs2_create_new_inode_locks(struct inode *inode)
1634{
1635 int ret;
1636 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1637
1638 BUG_ON(!ocfs2_inode_is_new(inode));
1639
1640 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
1641
1642 /* NOTE: That we don't increment any of the holder counts, nor
1643 * do we add anything to a journal handle. Since this is
1644 * supposed to be a new inode which the cluster doesn't know
1645 * about yet, there is no need to. As far as the LVB handling
1646 * is concerned, this is basically like acquiring an EX lock
1647 * on a resource which has an invalid one -- we'll set it
1648 * valid when we release the EX. */
1649
1650 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
1651 if (ret) {
1652 mlog_errno(ret);
1653 goto bail;
1654 }
1655
1656 /*
1657 * We don't want to use DLM_LKF_LOCAL on a meta data lock as they
1658 * don't use a generation in their lock names.
1659 */
1660 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
1661 if (ret) {
1662 mlog_errno(ret);
1663 goto bail;
1664 }
1665
1666 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
1667 if (ret)
1668 mlog_errno(ret);
1669
1670bail:
1671 return ret;
1672}
1673
1674int ocfs2_rw_lock(struct inode *inode, int write)
1675{
1676 int status, level;
1677 struct ocfs2_lock_res *lockres;
1678 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1679
1680 mlog(0, "inode %llu take %s RW lock\n",
1681 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1682 write ? "EXMODE" : "PRMODE");
1683
1684 if (ocfs2_mount_local(osb))
1685 return 0;
1686
1687 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1688
1689 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1690
1691 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
1692 0);
1693 if (status < 0)
1694 mlog_errno(status);
1695
1696 return status;
1697}
1698
1699void ocfs2_rw_unlock(struct inode *inode, int write)
1700{
1701 int level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1702 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
1703 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1704
1705 mlog(0, "inode %llu drop %s RW lock\n",
1706 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1707 write ? "EXMODE" : "PRMODE");
1708
1709 if (!ocfs2_mount_local(osb))
1710 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
1711}
1712
1713/*
1714 * ocfs2_open_lock always get PR mode lock.
1715 */
1716int ocfs2_open_lock(struct inode *inode)
1717{
1718 int status = 0;
1719 struct ocfs2_lock_res *lockres;
1720 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1721
1722 mlog(0, "inode %llu take PRMODE open lock\n",
1723 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1724
1725 if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb))
1726 goto out;
1727
1728 lockres = &OCFS2_I(inode)->ip_open_lockres;
1729
1730 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
1731 DLM_LOCK_PR, 0, 0);
1732 if (status < 0)
1733 mlog_errno(status);
1734
1735out:
1736 return status;
1737}
1738
1739int ocfs2_try_open_lock(struct inode *inode, int write)
1740{
1741 int status = 0, level;
1742 struct ocfs2_lock_res *lockres;
1743 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1744
1745 mlog(0, "inode %llu try to take %s open lock\n",
1746 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1747 write ? "EXMODE" : "PRMODE");
1748
1749 if (ocfs2_is_hard_readonly(osb)) {
1750 if (write)
1751 status = -EROFS;
1752 goto out;
1753 }
1754
1755 if (ocfs2_mount_local(osb))
1756 goto out;
1757
1758 lockres = &OCFS2_I(inode)->ip_open_lockres;
1759
1760 level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
1761
1762 /*
1763 * The file system may already holding a PRMODE/EXMODE open lock.
1764 * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on
1765 * other nodes and the -EAGAIN will indicate to the caller that
1766 * this inode is still in use.
1767 */
1768 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
1769 level, DLM_LKF_NOQUEUE, 0);
1770
1771out:
1772 return status;
1773}
1774
1775/*
1776 * ocfs2_open_unlock unlock PR and EX mode open locks.
1777 */
1778void ocfs2_open_unlock(struct inode *inode)
1779{
1780 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
1781 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1782
1783 mlog(0, "inode %llu drop open lock\n",
1784 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1785
1786 if (ocfs2_mount_local(osb))
1787 goto out;
1788
1789 if(lockres->l_ro_holders)
1790 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
1791 DLM_LOCK_PR);
1792 if(lockres->l_ex_holders)
1793 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
1794 DLM_LOCK_EX);
1795
1796out:
1797 return;
1798}
1799
1800static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
1801 int level)
1802{
1803 int ret;
1804 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1805 unsigned long flags;
1806 struct ocfs2_mask_waiter mw;
1807
1808 ocfs2_init_mask_waiter(&mw);
1809
1810retry_cancel:
1811 spin_lock_irqsave(&lockres->l_lock, flags);
1812 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
1813 ret = ocfs2_prepare_cancel_convert(osb, lockres);
1814 if (ret) {
1815 spin_unlock_irqrestore(&lockres->l_lock, flags);
1816 ret = ocfs2_cancel_convert(osb, lockres);
1817 if (ret < 0) {
1818 mlog_errno(ret);
1819 goto out;
1820 }
1821 goto retry_cancel;
1822 }
1823 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1824 spin_unlock_irqrestore(&lockres->l_lock, flags);
1825
1826 ocfs2_wait_for_mask(&mw);
1827 goto retry_cancel;
1828 }
1829
1830 ret = -ERESTARTSYS;
1831 /*
1832 * We may still have gotten the lock, in which case there's no
1833 * point to restarting the syscall.
1834 */
1835 if (lockres->l_level == level)
1836 ret = 0;
1837
1838 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
1839 lockres->l_flags, lockres->l_level, lockres->l_action);
1840
1841 spin_unlock_irqrestore(&lockres->l_lock, flags);
1842
1843out:
1844 return ret;
1845}
1846
1847/*
1848 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
1849 * flock() calls. The locking approach this requires is sufficiently
1850 * different from all other cluster lock types that we implement a
1851 * separate path to the "low-level" dlm calls. In particular:
1852 *
1853 * - No optimization of lock levels is done - we take at exactly
1854 * what's been requested.
1855 *
1856 * - No lock caching is employed. We immediately downconvert to
1857 * no-lock at unlock time. This also means flock locks never go on
1858 * the blocking list).
1859 *
1860 * - Since userspace can trivially deadlock itself with flock, we make
1861 * sure to allow cancellation of a misbehaving applications flock()
1862 * request.
1863 *
1864 * - Access to any flock lockres doesn't require concurrency, so we
1865 * can simplify the code by requiring the caller to guarantee
1866 * serialization of dlmglue flock calls.
1867 */
1868int ocfs2_file_lock(struct file *file, int ex, int trylock)
1869{
1870 int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
1871 unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
1872 unsigned long flags;
1873 struct ocfs2_file_private *fp = file->private_data;
1874 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1875 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1876 struct ocfs2_mask_waiter mw;
1877
1878 ocfs2_init_mask_waiter(&mw);
1879
1880 if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
1881 (lockres->l_level > DLM_LOCK_NL)) {
1882 mlog(ML_ERROR,
1883 "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
1884 "level: %u\n", lockres->l_name, lockres->l_flags,
1885 lockres->l_level);
1886 return -EINVAL;
1887 }
1888
1889 spin_lock_irqsave(&lockres->l_lock, flags);
1890 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1891 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1892 spin_unlock_irqrestore(&lockres->l_lock, flags);
1893
1894 /*
1895 * Get the lock at NLMODE to start - that way we
1896 * can cancel the upconvert request if need be.
1897 */
1898 ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
1899 if (ret < 0) {
1900 mlog_errno(ret);
1901 goto out;
1902 }
1903
1904 ret = ocfs2_wait_for_mask(&mw);
1905 if (ret) {
1906 mlog_errno(ret);
1907 goto out;
1908 }
1909 spin_lock_irqsave(&lockres->l_lock, flags);
1910 }
1911
1912 lockres->l_action = OCFS2_AST_CONVERT;
1913 lkm_flags |= DLM_LKF_CONVERT;
1914 lockres->l_requested = level;
1915 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1916
1917 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1918 spin_unlock_irqrestore(&lockres->l_lock, flags);
1919
1920 ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags,
1921 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1);
1922 if (ret) {
1923 if (!trylock || (ret != -EAGAIN)) {
1924 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
1925 ret = -EINVAL;
1926 }
1927
1928 ocfs2_recover_from_dlm_error(lockres, 1);
1929 lockres_remove_mask_waiter(lockres, &mw);
1930 goto out;
1931 }
1932
1933 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
1934 if (ret == -ERESTARTSYS) {
1935 /*
1936 * Userspace can cause deadlock itself with
1937 * flock(). Current behavior locally is to allow the
1938 * deadlock, but abort the system call if a signal is
1939 * received. We follow this example, otherwise a
1940 * poorly written program could sit in kernel until
1941 * reboot.
1942 *
1943 * Handling this is a bit more complicated for Ocfs2
1944 * though. We can't exit this function with an
1945 * outstanding lock request, so a cancel convert is
1946 * required. We intentionally overwrite 'ret' - if the
1947 * cancel fails and the lock was granted, it's easier
1948 * to just bubble success back up to the user.
1949 */
1950 ret = ocfs2_flock_handle_signal(lockres, level);
1951 } else if (!ret && (level > lockres->l_level)) {
1952 /* Trylock failed asynchronously */
1953 BUG_ON(!trylock);
1954 ret = -EAGAIN;
1955 }
1956
1957out:
1958
1959 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
1960 lockres->l_name, ex, trylock, ret);
1961 return ret;
1962}
1963
1964void ocfs2_file_unlock(struct file *file)
1965{
1966 int ret;
1967 unsigned int gen;
1968 unsigned long flags;
1969 struct ocfs2_file_private *fp = file->private_data;
1970 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1971 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1972 struct ocfs2_mask_waiter mw;
1973
1974 ocfs2_init_mask_waiter(&mw);
1975
1976 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
1977 return;
1978
1979 if (lockres->l_level == DLM_LOCK_NL)
1980 return;
1981
1982 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
1983 lockres->l_name, lockres->l_flags, lockres->l_level,
1984 lockres->l_action);
1985
1986 spin_lock_irqsave(&lockres->l_lock, flags);
1987 /*
1988 * Fake a blocking ast for the downconvert code.
1989 */
1990 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
1991 lockres->l_blocking = DLM_LOCK_EX;
1992
1993 gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
1994 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1995 spin_unlock_irqrestore(&lockres->l_lock, flags);
1996
1997 ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
1998 if (ret) {
1999 mlog_errno(ret);
2000 return;
2001 }
2002
2003 ret = ocfs2_wait_for_mask(&mw);
2004 if (ret)
2005 mlog_errno(ret);
2006}
2007
2008static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
2009 struct ocfs2_lock_res *lockres)
2010{
2011 int kick = 0;
2012
2013 /* If we know that another node is waiting on our lock, kick
2014 * the downconvert thread * pre-emptively when we reach a release
2015 * condition. */
2016 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
2017 switch(lockres->l_blocking) {
2018 case DLM_LOCK_EX:
2019 if (!lockres->l_ex_holders && !lockres->l_ro_holders)
2020 kick = 1;
2021 break;
2022 case DLM_LOCK_PR:
2023 if (!lockres->l_ex_holders)
2024 kick = 1;
2025 break;
2026 default:
2027 BUG();
2028 }
2029 }
2030
2031 if (kick)
2032 ocfs2_wake_downconvert_thread(osb);
2033}
2034
2035#define OCFS2_SEC_BITS 34
2036#define OCFS2_SEC_SHIFT (64 - 34)
2037#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
2038
2039/* LVB only has room for 64 bits of time here so we pack it for
2040 * now. */
2041static u64 ocfs2_pack_timespec(struct timespec *spec)
2042{
2043 u64 res;
2044 u64 sec = spec->tv_sec;
2045 u32 nsec = spec->tv_nsec;
2046
2047 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
2048
2049 return res;
2050}
2051
2052/* Call this with the lockres locked. I am reasonably sure we don't
2053 * need ip_lock in this function as anyone who would be changing those
2054 * values is supposed to be blocked in ocfs2_inode_lock right now. */
2055static void __ocfs2_stuff_meta_lvb(struct inode *inode)
2056{
2057 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2058 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2059 struct ocfs2_meta_lvb *lvb;
2060
2061 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2062
2063 /*
2064 * Invalidate the LVB of a deleted inode - this way other
2065 * nodes are forced to go to disk and discover the new inode
2066 * status.
2067 */
2068 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2069 lvb->lvb_version = 0;
2070 goto out;
2071 }
2072
2073 lvb->lvb_version = OCFS2_LVB_VERSION;
2074 lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
2075 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
2076 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode));
2077 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
2078 lvb->lvb_imode = cpu_to_be16(inode->i_mode);
2079 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
2080 lvb->lvb_iatime_packed =
2081 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
2082 lvb->lvb_ictime_packed =
2083 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
2084 lvb->lvb_imtime_packed =
2085 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
2086 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
2087 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
2088 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
2089
2090out:
2091 mlog_meta_lvb(0, lockres);
2092}
2093
2094static void ocfs2_unpack_timespec(struct timespec *spec,
2095 u64 packed_time)
2096{
2097 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
2098 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
2099}
2100
2101static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
2102{
2103 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2104 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2105 struct ocfs2_meta_lvb *lvb;
2106
2107 mlog_meta_lvb(0, lockres);
2108
2109 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2110
2111 /* We're safe here without the lockres lock... */
2112 spin_lock(&oi->ip_lock);
2113 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
2114 i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
2115
2116 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
2117 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
2118 ocfs2_set_inode_flags(inode);
2119
2120 /* fast-symlinks are a special case */
2121 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
2122 inode->i_blocks = 0;
2123 else
2124 inode->i_blocks = ocfs2_inode_sector_count(inode);
2125
2126 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid));
2127 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
2128 inode->i_mode = be16_to_cpu(lvb->lvb_imode);
2129 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
2130 ocfs2_unpack_timespec(&inode->i_atime,
2131 be64_to_cpu(lvb->lvb_iatime_packed));
2132 ocfs2_unpack_timespec(&inode->i_mtime,
2133 be64_to_cpu(lvb->lvb_imtime_packed));
2134 ocfs2_unpack_timespec(&inode->i_ctime,
2135 be64_to_cpu(lvb->lvb_ictime_packed));
2136 spin_unlock(&oi->ip_lock);
2137}
2138
2139static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
2140 struct ocfs2_lock_res *lockres)
2141{
2142 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2143
2144 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
2145 && lvb->lvb_version == OCFS2_LVB_VERSION
2146 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
2147 return 1;
2148 return 0;
2149}
2150
2151/* Determine whether a lock resource needs to be refreshed, and
2152 * arbitrate who gets to refresh it.
2153 *
2154 * 0 means no refresh needed.
2155 *
2156 * > 0 means you need to refresh this and you MUST call
2157 * ocfs2_complete_lock_res_refresh afterwards. */
2158static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
2159{
2160 unsigned long flags;
2161 int status = 0;
2162
2163refresh_check:
2164 spin_lock_irqsave(&lockres->l_lock, flags);
2165 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
2166 spin_unlock_irqrestore(&lockres->l_lock, flags);
2167 goto bail;
2168 }
2169
2170 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
2171 spin_unlock_irqrestore(&lockres->l_lock, flags);
2172
2173 ocfs2_wait_on_refreshing_lock(lockres);
2174 goto refresh_check;
2175 }
2176
2177 /* Ok, I'll be the one to refresh this lock. */
2178 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
2179 spin_unlock_irqrestore(&lockres->l_lock, flags);
2180
2181 status = 1;
2182bail:
2183 mlog(0, "status %d\n", status);
2184 return status;
2185}
2186
2187/* If status is non zero, I'll mark it as not being in refresh
2188 * anymroe, but i won't clear the needs refresh flag. */
2189static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
2190 int status)
2191{
2192 unsigned long flags;
2193
2194 spin_lock_irqsave(&lockres->l_lock, flags);
2195 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
2196 if (!status)
2197 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
2198 spin_unlock_irqrestore(&lockres->l_lock, flags);
2199
2200 wake_up(&lockres->l_event);
2201}
2202
2203/* may or may not return a bh if it went to disk. */
2204static int ocfs2_inode_lock_update(struct inode *inode,
2205 struct buffer_head **bh)
2206{
2207 int status = 0;
2208 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2209 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2210 struct ocfs2_dinode *fe;
2211 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2212
2213 if (ocfs2_mount_local(osb))
2214 goto bail;
2215
2216 spin_lock(&oi->ip_lock);
2217 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2218 mlog(0, "Orphaned inode %llu was deleted while we "
2219 "were waiting on a lock. ip_flags = 0x%x\n",
2220 (unsigned long long)oi->ip_blkno, oi->ip_flags);
2221 spin_unlock(&oi->ip_lock);
2222 status = -ENOENT;
2223 goto bail;
2224 }
2225 spin_unlock(&oi->ip_lock);
2226
2227 if (!ocfs2_should_refresh_lock_res(lockres))
2228 goto bail;
2229
2230 /* This will discard any caching information we might have had
2231 * for the inode metadata. */
2232 ocfs2_metadata_cache_purge(INODE_CACHE(inode));
2233
2234 ocfs2_extent_map_trunc(inode, 0);
2235
2236 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
2237 mlog(0, "Trusting LVB on inode %llu\n",
2238 (unsigned long long)oi->ip_blkno);
2239 ocfs2_refresh_inode_from_lvb(inode);
2240 } else {
2241 /* Boo, we have to go to disk. */
2242 /* read bh, cast, ocfs2_refresh_inode */
2243 status = ocfs2_read_inode_block(inode, bh);
2244 if (status < 0) {
2245 mlog_errno(status);
2246 goto bail_refresh;
2247 }
2248 fe = (struct ocfs2_dinode *) (*bh)->b_data;
2249
2250 /* This is a good chance to make sure we're not
2251 * locking an invalid object. ocfs2_read_inode_block()
2252 * already checked that the inode block is sane.
2253 *
2254 * We bug on a stale inode here because we checked
2255 * above whether it was wiped from disk. The wiping
2256 * node provides a guarantee that we receive that
2257 * message and can mark the inode before dropping any
2258 * locks associated with it. */
2259 mlog_bug_on_msg(inode->i_generation !=
2260 le32_to_cpu(fe->i_generation),
2261 "Invalid dinode %llu disk generation: %u "
2262 "inode->i_generation: %u\n",
2263 (unsigned long long)oi->ip_blkno,
2264 le32_to_cpu(fe->i_generation),
2265 inode->i_generation);
2266 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
2267 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
2268 "Stale dinode %llu dtime: %llu flags: 0x%x\n",
2269 (unsigned long long)oi->ip_blkno,
2270 (unsigned long long)le64_to_cpu(fe->i_dtime),
2271 le32_to_cpu(fe->i_flags));
2272
2273 ocfs2_refresh_inode(inode, fe);
2274 ocfs2_track_lock_refresh(lockres);
2275 }
2276
2277 status = 0;
2278bail_refresh:
2279 ocfs2_complete_lock_res_refresh(lockres, status);
2280bail:
2281 return status;
2282}
2283
2284static int ocfs2_assign_bh(struct inode *inode,
2285 struct buffer_head **ret_bh,
2286 struct buffer_head *passed_bh)
2287{
2288 int status;
2289
2290 if (passed_bh) {
2291 /* Ok, the update went to disk for us, use the
2292 * returned bh. */
2293 *ret_bh = passed_bh;
2294 get_bh(*ret_bh);
2295
2296 return 0;
2297 }
2298
2299 status = ocfs2_read_inode_block(inode, ret_bh);
2300 if (status < 0)
2301 mlog_errno(status);
2302
2303 return status;
2304}
2305
2306/*
2307 * returns < 0 error if the callback will never be called, otherwise
2308 * the result of the lock will be communicated via the callback.
2309 */
2310int ocfs2_inode_lock_full_nested(struct inode *inode,
2311 struct buffer_head **ret_bh,
2312 int ex,
2313 int arg_flags,
2314 int subclass)
2315{
2316 int status, level, acquired;
2317 u32 dlm_flags;
2318 struct ocfs2_lock_res *lockres = NULL;
2319 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2320 struct buffer_head *local_bh = NULL;
2321
2322 mlog(0, "inode %llu, take %s META lock\n",
2323 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2324 ex ? "EXMODE" : "PRMODE");
2325
2326 status = 0;
2327 acquired = 0;
2328 /* We'll allow faking a readonly metadata lock for
2329 * rodevices. */
2330 if (ocfs2_is_hard_readonly(osb)) {
2331 if (ex)
2332 status = -EROFS;
2333 goto getbh;
2334 }
2335
2336 if (ocfs2_mount_local(osb))
2337 goto local;
2338
2339 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2340 ocfs2_wait_for_recovery(osb);
2341
2342 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2343 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2344 dlm_flags = 0;
2345 if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
2346 dlm_flags |= DLM_LKF_NOQUEUE;
2347
2348 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
2349 arg_flags, subclass, _RET_IP_);
2350 if (status < 0) {
2351 if (status != -EAGAIN)
2352 mlog_errno(status);
2353 goto bail;
2354 }
2355
2356 /* Notify the error cleanup path to drop the cluster lock. */
2357 acquired = 1;
2358
2359 /* We wait twice because a node may have died while we were in
2360 * the lower dlm layers. The second time though, we've
2361 * committed to owning this lock so we don't allow signals to
2362 * abort the operation. */
2363 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2364 ocfs2_wait_for_recovery(osb);
2365
2366local:
2367 /*
2368 * We only see this flag if we're being called from
2369 * ocfs2_read_locked_inode(). It means we're locking an inode
2370 * which hasn't been populated yet, so clear the refresh flag
2371 * and let the caller handle it.
2372 */
2373 if (inode->i_state & I_NEW) {
2374 status = 0;
2375 if (lockres)
2376 ocfs2_complete_lock_res_refresh(lockres, 0);
2377 goto bail;
2378 }
2379
2380 /* This is fun. The caller may want a bh back, or it may
2381 * not. ocfs2_inode_lock_update definitely wants one in, but
2382 * may or may not read one, depending on what's in the
2383 * LVB. The result of all of this is that we've *only* gone to
2384 * disk if we have to, so the complexity is worthwhile. */
2385 status = ocfs2_inode_lock_update(inode, &local_bh);
2386 if (status < 0) {
2387 if (status != -ENOENT)
2388 mlog_errno(status);
2389 goto bail;
2390 }
2391getbh:
2392 if (ret_bh) {
2393 status = ocfs2_assign_bh(inode, ret_bh, local_bh);
2394 if (status < 0) {
2395 mlog_errno(status);
2396 goto bail;
2397 }
2398 }
2399
2400bail:
2401 if (status < 0) {
2402 if (ret_bh && (*ret_bh)) {
2403 brelse(*ret_bh);
2404 *ret_bh = NULL;
2405 }
2406 if (acquired)
2407 ocfs2_inode_unlock(inode, ex);
2408 }
2409
2410 if (local_bh)
2411 brelse(local_bh);
2412
2413 return status;
2414}
2415
2416/*
2417 * This is working around a lock inversion between tasks acquiring DLM
2418 * locks while holding a page lock and the downconvert thread which
2419 * blocks dlm lock acquiry while acquiring page locks.
2420 *
2421 * ** These _with_page variantes are only intended to be called from aop
2422 * methods that hold page locks and return a very specific *positive* error
2423 * code that aop methods pass up to the VFS -- test for errors with != 0. **
2424 *
2425 * The DLM is called such that it returns -EAGAIN if it would have
2426 * blocked waiting for the downconvert thread. In that case we unlock
2427 * our page so the downconvert thread can make progress. Once we've
2428 * done this we have to return AOP_TRUNCATED_PAGE so the aop method
2429 * that called us can bubble that back up into the VFS who will then
2430 * immediately retry the aop call.
2431 */
2432int ocfs2_inode_lock_with_page(struct inode *inode,
2433 struct buffer_head **ret_bh,
2434 int ex,
2435 struct page *page)
2436{
2437 int ret;
2438
2439 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
2440 if (ret == -EAGAIN) {
2441 unlock_page(page);
2442 ret = AOP_TRUNCATED_PAGE;
2443 }
2444
2445 return ret;
2446}
2447
2448int ocfs2_inode_lock_atime(struct inode *inode,
2449 struct vfsmount *vfsmnt,
2450 int *level)
2451{
2452 int ret;
2453
2454 ret = ocfs2_inode_lock(inode, NULL, 0);
2455 if (ret < 0) {
2456 mlog_errno(ret);
2457 return ret;
2458 }
2459
2460 /*
2461 * If we should update atime, we will get EX lock,
2462 * otherwise we just get PR lock.
2463 */
2464 if (ocfs2_should_update_atime(inode, vfsmnt)) {
2465 struct buffer_head *bh = NULL;
2466
2467 ocfs2_inode_unlock(inode, 0);
2468 ret = ocfs2_inode_lock(inode, &bh, 1);
2469 if (ret < 0) {
2470 mlog_errno(ret);
2471 return ret;
2472 }
2473 *level = 1;
2474 if (ocfs2_should_update_atime(inode, vfsmnt))
2475 ocfs2_update_inode_atime(inode, bh);
2476 if (bh)
2477 brelse(bh);
2478 } else
2479 *level = 0;
2480
2481 return ret;
2482}
2483
2484void ocfs2_inode_unlock(struct inode *inode,
2485 int ex)
2486{
2487 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2488 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
2489 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2490
2491 mlog(0, "inode %llu drop %s META lock\n",
2492 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2493 ex ? "EXMODE" : "PRMODE");
2494
2495 if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
2496 !ocfs2_mount_local(osb))
2497 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
2498}
2499
2500int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
2501{
2502 struct ocfs2_lock_res *lockres;
2503 struct ocfs2_orphan_scan_lvb *lvb;
2504 int status = 0;
2505
2506 if (ocfs2_is_hard_readonly(osb))
2507 return -EROFS;
2508
2509 if (ocfs2_mount_local(osb))
2510 return 0;
2511
2512 lockres = &osb->osb_orphan_scan.os_lockres;
2513 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2514 if (status < 0)
2515 return status;
2516
2517 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2518 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2519 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
2520 *seqno = be32_to_cpu(lvb->lvb_os_seqno);
2521 else
2522 *seqno = osb->osb_orphan_scan.os_seqno + 1;
2523
2524 return status;
2525}
2526
2527void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
2528{
2529 struct ocfs2_lock_res *lockres;
2530 struct ocfs2_orphan_scan_lvb *lvb;
2531
2532 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
2533 lockres = &osb->osb_orphan_scan.os_lockres;
2534 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2535 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
2536 lvb->lvb_os_seqno = cpu_to_be32(seqno);
2537 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2538 }
2539}
2540
2541int ocfs2_super_lock(struct ocfs2_super *osb,
2542 int ex)
2543{
2544 int status = 0;
2545 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2546 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2547
2548 if (ocfs2_is_hard_readonly(osb))
2549 return -EROFS;
2550
2551 if (ocfs2_mount_local(osb))
2552 goto bail;
2553
2554 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
2555 if (status < 0) {
2556 mlog_errno(status);
2557 goto bail;
2558 }
2559
2560 /* The super block lock path is really in the best position to
2561 * know when resources covered by the lock need to be
2562 * refreshed, so we do it here. Of course, making sense of
2563 * everything is up to the caller :) */
2564 status = ocfs2_should_refresh_lock_res(lockres);
2565 if (status) {
2566 status = ocfs2_refresh_slot_info(osb);
2567
2568 ocfs2_complete_lock_res_refresh(lockres, status);
2569
2570 if (status < 0) {
2571 ocfs2_cluster_unlock(osb, lockres, level);
2572 mlog_errno(status);
2573 }
2574 ocfs2_track_lock_refresh(lockres);
2575 }
2576bail:
2577 return status;
2578}
2579
2580void ocfs2_super_unlock(struct ocfs2_super *osb,
2581 int ex)
2582{
2583 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2584 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2585
2586 if (!ocfs2_mount_local(osb))
2587 ocfs2_cluster_unlock(osb, lockres, level);
2588}
2589
2590int ocfs2_rename_lock(struct ocfs2_super *osb)
2591{
2592 int status;
2593 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2594
2595 if (ocfs2_is_hard_readonly(osb))
2596 return -EROFS;
2597
2598 if (ocfs2_mount_local(osb))
2599 return 0;
2600
2601 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2602 if (status < 0)
2603 mlog_errno(status);
2604
2605 return status;
2606}
2607
2608void ocfs2_rename_unlock(struct ocfs2_super *osb)
2609{
2610 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2611
2612 if (!ocfs2_mount_local(osb))
2613 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2614}
2615
2616int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
2617{
2618 int status;
2619 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2620
2621 if (ocfs2_is_hard_readonly(osb))
2622 return -EROFS;
2623
2624 if (ocfs2_mount_local(osb))
2625 return 0;
2626
2627 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
2628 0, 0);
2629 if (status < 0)
2630 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
2631
2632 return status;
2633}
2634
2635void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
2636{
2637 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2638
2639 if (!ocfs2_mount_local(osb))
2640 ocfs2_cluster_unlock(osb, lockres,
2641 ex ? LKM_EXMODE : LKM_PRMODE);
2642}
2643
2644int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2645{
2646 int ret;
2647 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2648 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2649 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2650
2651 BUG_ON(!dl);
2652
2653 if (ocfs2_is_hard_readonly(osb)) {
2654 if (ex)
2655 return -EROFS;
2656 return 0;
2657 }
2658
2659 if (ocfs2_mount_local(osb))
2660 return 0;
2661
2662 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2663 if (ret < 0)
2664 mlog_errno(ret);
2665
2666 return ret;
2667}
2668
2669void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2670{
2671 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2672 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2673 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2674
2675 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
2676 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
2677}
2678
2679/* Reference counting of the dlm debug structure. We want this because
2680 * open references on the debug inodes can live on after a mount, so
2681 * we can't rely on the ocfs2_super to always exist. */
2682static void ocfs2_dlm_debug_free(struct kref *kref)
2683{
2684 struct ocfs2_dlm_debug *dlm_debug;
2685
2686 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
2687
2688 kfree(dlm_debug);
2689}
2690
2691void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
2692{
2693 if (dlm_debug)
2694 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
2695}
2696
2697static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
2698{
2699 kref_get(&debug->d_refcnt);
2700}
2701
2702struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
2703{
2704 struct ocfs2_dlm_debug *dlm_debug;
2705
2706 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
2707 if (!dlm_debug) {
2708 mlog_errno(-ENOMEM);
2709 goto out;
2710 }
2711
2712 kref_init(&dlm_debug->d_refcnt);
2713 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
2714 dlm_debug->d_locking_state = NULL;
2715out:
2716 return dlm_debug;
2717}
2718
2719/* Access to this is arbitrated for us via seq_file->sem. */
2720struct ocfs2_dlm_seq_priv {
2721 struct ocfs2_dlm_debug *p_dlm_debug;
2722 struct ocfs2_lock_res p_iter_res;
2723 struct ocfs2_lock_res p_tmp_res;
2724};
2725
2726static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
2727 struct ocfs2_dlm_seq_priv *priv)
2728{
2729 struct ocfs2_lock_res *iter, *ret = NULL;
2730 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
2731
2732 assert_spin_locked(&ocfs2_dlm_tracking_lock);
2733
2734 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
2735 /* discover the head of the list */
2736 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
2737 mlog(0, "End of list found, %p\n", ret);
2738 break;
2739 }
2740
2741 /* We track our "dummy" iteration lockres' by a NULL
2742 * l_ops field. */
2743 if (iter->l_ops != NULL) {
2744 ret = iter;
2745 break;
2746 }
2747 }
2748
2749 return ret;
2750}
2751
2752static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
2753{
2754 struct ocfs2_dlm_seq_priv *priv = m->private;
2755 struct ocfs2_lock_res *iter;
2756
2757 spin_lock(&ocfs2_dlm_tracking_lock);
2758 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
2759 if (iter) {
2760 /* Since lockres' have the lifetime of their container
2761 * (which can be inodes, ocfs2_supers, etc) we want to
2762 * copy this out to a temporary lockres while still
2763 * under the spinlock. Obviously after this we can't
2764 * trust any pointers on the copy returned, but that's
2765 * ok as the information we want isn't typically held
2766 * in them. */
2767 priv->p_tmp_res = *iter;
2768 iter = &priv->p_tmp_res;
2769 }
2770 spin_unlock(&ocfs2_dlm_tracking_lock);
2771
2772 return iter;
2773}
2774
2775static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
2776{
2777}
2778
2779static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
2780{
2781 struct ocfs2_dlm_seq_priv *priv = m->private;
2782 struct ocfs2_lock_res *iter = v;
2783 struct ocfs2_lock_res *dummy = &priv->p_iter_res;
2784
2785 spin_lock(&ocfs2_dlm_tracking_lock);
2786 iter = ocfs2_dlm_next_res(iter, priv);
2787 list_del_init(&dummy->l_debug_list);
2788 if (iter) {
2789 list_add(&dummy->l_debug_list, &iter->l_debug_list);
2790 priv->p_tmp_res = *iter;
2791 iter = &priv->p_tmp_res;
2792 }
2793 spin_unlock(&ocfs2_dlm_tracking_lock);
2794
2795 return iter;
2796}
2797
2798/*
2799 * Version is used by debugfs.ocfs2 to determine the format being used
2800 *
2801 * New in version 2
2802 * - Lock stats printed
2803 * New in version 3
2804 * - Max time in lock stats is in usecs (instead of nsecs)
2805 */
2806#define OCFS2_DLM_DEBUG_STR_VERSION 3
2807static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
2808{
2809 int i;
2810 char *lvb;
2811 struct ocfs2_lock_res *lockres = v;
2812
2813 if (!lockres)
2814 return -EINVAL;
2815
2816 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
2817
2818 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
2819 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
2820 lockres->l_name,
2821 (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
2822 else
2823 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
2824
2825 seq_printf(m, "%d\t"
2826 "0x%lx\t"
2827 "0x%x\t"
2828 "0x%x\t"
2829 "%u\t"
2830 "%u\t"
2831 "%d\t"
2832 "%d\t",
2833 lockres->l_level,
2834 lockres->l_flags,
2835 lockres->l_action,
2836 lockres->l_unlock_action,
2837 lockres->l_ro_holders,
2838 lockres->l_ex_holders,
2839 lockres->l_requested,
2840 lockres->l_blocking);
2841
2842 /* Dump the raw LVB */
2843 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2844 for(i = 0; i < DLM_LVB_LEN; i++)
2845 seq_printf(m, "0x%x\t", lvb[i]);
2846
2847#ifdef CONFIG_OCFS2_FS_STATS
2848# define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets)
2849# define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets)
2850# define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail)
2851# define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail)
2852# define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total)
2853# define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total)
2854# define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max)
2855# define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max)
2856# define lock_refresh(_l) ((_l)->l_lock_refresh)
2857#else
2858# define lock_num_prmode(_l) (0)
2859# define lock_num_exmode(_l) (0)
2860# define lock_num_prmode_failed(_l) (0)
2861# define lock_num_exmode_failed(_l) (0)
2862# define lock_total_prmode(_l) (0ULL)
2863# define lock_total_exmode(_l) (0ULL)
2864# define lock_max_prmode(_l) (0)
2865# define lock_max_exmode(_l) (0)
2866# define lock_refresh(_l) (0)
2867#endif
2868 /* The following seq_print was added in version 2 of this output */
2869 seq_printf(m, "%u\t"
2870 "%u\t"
2871 "%u\t"
2872 "%u\t"
2873 "%llu\t"
2874 "%llu\t"
2875 "%u\t"
2876 "%u\t"
2877 "%u\t",
2878 lock_num_prmode(lockres),
2879 lock_num_exmode(lockres),
2880 lock_num_prmode_failed(lockres),
2881 lock_num_exmode_failed(lockres),
2882 lock_total_prmode(lockres),
2883 lock_total_exmode(lockres),
2884 lock_max_prmode(lockres),
2885 lock_max_exmode(lockres),
2886 lock_refresh(lockres));
2887
2888 /* End the line */
2889 seq_printf(m, "\n");
2890 return 0;
2891}
2892
2893static const struct seq_operations ocfs2_dlm_seq_ops = {
2894 .start = ocfs2_dlm_seq_start,
2895 .stop = ocfs2_dlm_seq_stop,
2896 .next = ocfs2_dlm_seq_next,
2897 .show = ocfs2_dlm_seq_show,
2898};
2899
2900static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
2901{
2902 struct seq_file *seq = file->private_data;
2903 struct ocfs2_dlm_seq_priv *priv = seq->private;
2904 struct ocfs2_lock_res *res = &priv->p_iter_res;
2905
2906 ocfs2_remove_lockres_tracking(res);
2907 ocfs2_put_dlm_debug(priv->p_dlm_debug);
2908 return seq_release_private(inode, file);
2909}
2910
2911static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
2912{
2913 struct ocfs2_dlm_seq_priv *priv;
2914 struct ocfs2_super *osb;
2915
2916 priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv));
2917 if (!priv) {
2918 mlog_errno(-ENOMEM);
2919 return -ENOMEM;
2920 }
2921
2922 osb = inode->i_private;
2923 ocfs2_get_dlm_debug(osb->osb_dlm_debug);
2924 priv->p_dlm_debug = osb->osb_dlm_debug;
2925 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
2926
2927 ocfs2_add_lockres_tracking(&priv->p_iter_res,
2928 priv->p_dlm_debug);
2929
2930 return 0;
2931}
2932
2933static const struct file_operations ocfs2_dlm_debug_fops = {
2934 .open = ocfs2_dlm_debug_open,
2935 .release = ocfs2_dlm_debug_release,
2936 .read = seq_read,
2937 .llseek = seq_lseek,
2938};
2939
2940static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
2941{
2942 int ret = 0;
2943 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
2944
2945 dlm_debug->d_locking_state = debugfs_create_file("locking_state",
2946 S_IFREG|S_IRUSR,
2947 osb->osb_debug_root,
2948 osb,
2949 &ocfs2_dlm_debug_fops);
2950 if (!dlm_debug->d_locking_state) {
2951 ret = -EINVAL;
2952 mlog(ML_ERROR,
2953 "Unable to create locking state debugfs file.\n");
2954 goto out;
2955 }
2956
2957 ocfs2_get_dlm_debug(dlm_debug);
2958out:
2959 return ret;
2960}
2961
2962static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
2963{
2964 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
2965
2966 if (dlm_debug) {
2967 debugfs_remove(dlm_debug->d_locking_state);
2968 ocfs2_put_dlm_debug(dlm_debug);
2969 }
2970}
2971
2972int ocfs2_dlm_init(struct ocfs2_super *osb)
2973{
2974 int status = 0;
2975 struct ocfs2_cluster_connection *conn = NULL;
2976
2977 if (ocfs2_mount_local(osb)) {
2978 osb->node_num = 0;
2979 goto local;
2980 }
2981
2982 status = ocfs2_dlm_init_debug(osb);
2983 if (status < 0) {
2984 mlog_errno(status);
2985 goto bail;
2986 }
2987
2988 /* launch downconvert thread */
2989 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s",
2990 osb->uuid_str);
2991 if (IS_ERR(osb->dc_task)) {
2992 status = PTR_ERR(osb->dc_task);
2993 osb->dc_task = NULL;
2994 mlog_errno(status);
2995 goto bail;
2996 }
2997
2998 /* for now, uuid == domain */
2999 status = ocfs2_cluster_connect(osb->osb_cluster_stack,
3000 osb->osb_cluster_name,
3001 strlen(osb->osb_cluster_name),
3002 osb->uuid_str,
3003 strlen(osb->uuid_str),
3004 &lproto, ocfs2_do_node_down, osb,
3005 &conn);
3006 if (status) {
3007 mlog_errno(status);
3008 goto bail;
3009 }
3010
3011 status = ocfs2_cluster_this_node(conn, &osb->node_num);
3012 if (status < 0) {
3013 mlog_errno(status);
3014 mlog(ML_ERROR,
3015 "could not find this host's node number\n");
3016 ocfs2_cluster_disconnect(conn, 0);
3017 goto bail;
3018 }
3019
3020local:
3021 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
3022 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
3023 ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
3024 ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
3025
3026 osb->cconn = conn;
3027bail:
3028 if (status < 0) {
3029 ocfs2_dlm_shutdown_debug(osb);
3030 if (osb->dc_task)
3031 kthread_stop(osb->dc_task);
3032 }
3033
3034 return status;
3035}
3036
3037void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
3038 int hangup_pending)
3039{
3040 ocfs2_drop_osb_locks(osb);
3041
3042 /*
3043 * Now that we have dropped all locks and ocfs2_dismount_volume()
3044 * has disabled recovery, the DLM won't be talking to us. It's
3045 * safe to tear things down before disconnecting the cluster.
3046 */
3047
3048 if (osb->dc_task) {
3049 kthread_stop(osb->dc_task);
3050 osb->dc_task = NULL;
3051 }
3052
3053 ocfs2_lock_res_free(&osb->osb_super_lockres);
3054 ocfs2_lock_res_free(&osb->osb_rename_lockres);
3055 ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
3056 ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
3057
3058 ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
3059 osb->cconn = NULL;
3060
3061 ocfs2_dlm_shutdown_debug(osb);
3062}
3063
3064static int ocfs2_drop_lock(struct ocfs2_super *osb,
3065 struct ocfs2_lock_res *lockres)
3066{
3067 int ret;
3068 unsigned long flags;
3069 u32 lkm_flags = 0;
3070
3071 /* We didn't get anywhere near actually using this lockres. */
3072 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
3073 goto out;
3074
3075 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3076 lkm_flags |= DLM_LKF_VALBLK;
3077
3078 spin_lock_irqsave(&lockres->l_lock, flags);
3079
3080 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
3081 "lockres %s, flags 0x%lx\n",
3082 lockres->l_name, lockres->l_flags);
3083
3084 while (lockres->l_flags & OCFS2_LOCK_BUSY) {
3085 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
3086 "%u, unlock_action = %u\n",
3087 lockres->l_name, lockres->l_flags, lockres->l_action,
3088 lockres->l_unlock_action);
3089
3090 spin_unlock_irqrestore(&lockres->l_lock, flags);
3091
3092 /* XXX: Today we just wait on any busy
3093 * locks... Perhaps we need to cancel converts in the
3094 * future? */
3095 ocfs2_wait_on_busy_lock(lockres);
3096
3097 spin_lock_irqsave(&lockres->l_lock, flags);
3098 }
3099
3100 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3101 if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
3102 lockres->l_level == DLM_LOCK_EX &&
3103 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3104 lockres->l_ops->set_lvb(lockres);
3105 }
3106
3107 if (lockres->l_flags & OCFS2_LOCK_BUSY)
3108 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
3109 lockres->l_name);
3110 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
3111 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
3112
3113 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
3114 spin_unlock_irqrestore(&lockres->l_lock, flags);
3115 goto out;
3116 }
3117
3118 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
3119
3120 /* make sure we never get here while waiting for an ast to
3121 * fire. */
3122 BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
3123
3124 /* is this necessary? */
3125 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3126 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
3127 spin_unlock_irqrestore(&lockres->l_lock, flags);
3128
3129 mlog(0, "lock %s\n", lockres->l_name);
3130
3131 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags);
3132 if (ret) {
3133 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3134 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
3135 ocfs2_dlm_dump_lksb(&lockres->l_lksb);
3136 BUG();
3137 }
3138 mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n",
3139 lockres->l_name);
3140
3141 ocfs2_wait_on_busy_lock(lockres);
3142out:
3143 return 0;
3144}
3145
3146static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3147 struct ocfs2_lock_res *lockres);
3148
3149/* Mark the lockres as being dropped. It will no longer be
3150 * queued if blocking, but we still may have to wait on it
3151 * being dequeued from the downconvert thread before we can consider
3152 * it safe to drop.
3153 *
3154 * You can *not* attempt to call cluster_lock on this lockres anymore. */
3155void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb,
3156 struct ocfs2_lock_res *lockres)
3157{
3158 int status;
3159 struct ocfs2_mask_waiter mw;
3160 unsigned long flags, flags2;
3161
3162 ocfs2_init_mask_waiter(&mw);
3163
3164 spin_lock_irqsave(&lockres->l_lock, flags);
3165 lockres->l_flags |= OCFS2_LOCK_FREEING;
3166 if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) {
3167 /*
3168 * We know the downconvert is queued but not in progress
3169 * because we are the downconvert thread and processing
3170 * different lock. So we can just remove the lock from the
3171 * queue. This is not only an optimization but also a way
3172 * to avoid the following deadlock:
3173 * ocfs2_dentry_post_unlock()
3174 * ocfs2_dentry_lock_put()
3175 * ocfs2_drop_dentry_lock()
3176 * iput()
3177 * ocfs2_evict_inode()
3178 * ocfs2_clear_inode()
3179 * ocfs2_mark_lockres_freeing()
3180 * ... blocks waiting for OCFS2_LOCK_QUEUED
3181 * since we are the downconvert thread which
3182 * should clear the flag.
3183 */
3184 spin_unlock_irqrestore(&lockres->l_lock, flags);
3185 spin_lock_irqsave(&osb->dc_task_lock, flags2);
3186 list_del_init(&lockres->l_blocked_list);
3187 osb->blocked_lock_count--;
3188 spin_unlock_irqrestore(&osb->dc_task_lock, flags2);
3189 /*
3190 * Warn if we recurse into another post_unlock call. Strictly
3191 * speaking it isn't a problem but we need to be careful if
3192 * that happens (stack overflow, deadlocks, ...) so warn if
3193 * ocfs2 grows a path for which this can happen.
3194 */
3195 WARN_ON_ONCE(lockres->l_ops->post_unlock);
3196 /* Since the lock is freeing we don't do much in the fn below */
3197 ocfs2_process_blocked_lock(osb, lockres);
3198 return;
3199 }
3200 while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
3201 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
3202 spin_unlock_irqrestore(&lockres->l_lock, flags);
3203
3204 mlog(0, "Waiting on lockres %s\n", lockres->l_name);
3205
3206 status = ocfs2_wait_for_mask(&mw);
3207 if (status)
3208 mlog_errno(status);
3209
3210 spin_lock_irqsave(&lockres->l_lock, flags);
3211 }
3212 spin_unlock_irqrestore(&lockres->l_lock, flags);
3213}
3214
3215void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
3216 struct ocfs2_lock_res *lockres)
3217{
3218 int ret;
3219
3220 ocfs2_mark_lockres_freeing(osb, lockres);
3221 ret = ocfs2_drop_lock(osb, lockres);
3222 if (ret)
3223 mlog_errno(ret);
3224}
3225
3226static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
3227{
3228 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
3229 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
3230 ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
3231 ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
3232}
3233
3234int ocfs2_drop_inode_locks(struct inode *inode)
3235{
3236 int status, err;
3237
3238 /* No need to call ocfs2_mark_lockres_freeing here -
3239 * ocfs2_clear_inode has done it for us. */
3240
3241 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3242 &OCFS2_I(inode)->ip_open_lockres);
3243 if (err < 0)
3244 mlog_errno(err);
3245
3246 status = err;
3247
3248 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3249 &OCFS2_I(inode)->ip_inode_lockres);
3250 if (err < 0)
3251 mlog_errno(err);
3252 if (err < 0 && !status)
3253 status = err;
3254
3255 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
3256 &OCFS2_I(inode)->ip_rw_lockres);
3257 if (err < 0)
3258 mlog_errno(err);
3259 if (err < 0 && !status)
3260 status = err;
3261
3262 return status;
3263}
3264
3265static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
3266 int new_level)
3267{
3268 assert_spin_locked(&lockres->l_lock);
3269
3270 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
3271
3272 if (lockres->l_level <= new_level) {
3273 mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
3274 "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
3275 "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
3276 new_level, list_empty(&lockres->l_blocked_list),
3277 list_empty(&lockres->l_mask_waiters), lockres->l_type,
3278 lockres->l_flags, lockres->l_ro_holders,
3279 lockres->l_ex_holders, lockres->l_action,
3280 lockres->l_unlock_action, lockres->l_requested,
3281 lockres->l_blocking, lockres->l_pending_gen);
3282 BUG();
3283 }
3284
3285 mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
3286 lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
3287
3288 lockres->l_action = OCFS2_AST_DOWNCONVERT;
3289 lockres->l_requested = new_level;
3290 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
3291 return lockres_set_pending(lockres);
3292}
3293
3294static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
3295 struct ocfs2_lock_res *lockres,
3296 int new_level,
3297 int lvb,
3298 unsigned int generation)
3299{
3300 int ret;
3301 u32 dlm_flags = DLM_LKF_CONVERT;
3302
3303 mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
3304 lockres->l_level, new_level);
3305
3306 /*
3307 * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always
3308 * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that
3309 * we can recover correctly from node failure. Otherwise, we may get
3310 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALIDÂ being set.
3311 */
3312 if (!ocfs2_is_o2cb_active() &&
3313 lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
3314 lvb = 1;
3315
3316 if (lvb)
3317 dlm_flags |= DLM_LKF_VALBLK;
3318
3319 ret = ocfs2_dlm_lock(osb->cconn,
3320 new_level,
3321 &lockres->l_lksb,
3322 dlm_flags,
3323 lockres->l_name,
3324 OCFS2_LOCK_ID_MAX_LEN - 1);
3325 lockres_clear_pending(lockres, generation, osb);
3326 if (ret) {
3327 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
3328 ocfs2_recover_from_dlm_error(lockres, 1);
3329 goto bail;
3330 }
3331
3332 ret = 0;
3333bail:
3334 return ret;
3335}
3336
3337/* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */
3338static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
3339 struct ocfs2_lock_res *lockres)
3340{
3341 assert_spin_locked(&lockres->l_lock);
3342
3343 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
3344 /* If we're already trying to cancel a lock conversion
3345 * then just drop the spinlock and allow the caller to
3346 * requeue this lock. */
3347 mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
3348 return 0;
3349 }
3350
3351 /* were we in a convert when we got the bast fire? */
3352 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
3353 lockres->l_action != OCFS2_AST_DOWNCONVERT);
3354 /* set things up for the unlockast to know to just
3355 * clear out the ast_action and unset busy, etc. */
3356 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
3357
3358 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
3359 "lock %s, invalid flags: 0x%lx\n",
3360 lockres->l_name, lockres->l_flags);
3361
3362 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3363
3364 return 1;
3365}
3366
3367static int ocfs2_cancel_convert(struct ocfs2_super *osb,
3368 struct ocfs2_lock_res *lockres)
3369{
3370 int ret;
3371
3372 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
3373 DLM_LKF_CANCEL);
3374 if (ret) {
3375 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
3376 ocfs2_recover_from_dlm_error(lockres, 0);
3377 }
3378
3379 mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
3380
3381 return ret;
3382}
3383
3384static int ocfs2_unblock_lock(struct ocfs2_super *osb,
3385 struct ocfs2_lock_res *lockres,
3386 struct ocfs2_unblock_ctl *ctl)
3387{
3388 unsigned long flags;
3389 int blocking;
3390 int new_level;
3391 int level;
3392 int ret = 0;
3393 int set_lvb = 0;
3394 unsigned int gen;
3395
3396 spin_lock_irqsave(&lockres->l_lock, flags);
3397
3398recheck:
3399 /*
3400 * Is it still blocking? If not, we have no more work to do.
3401 */
3402 if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
3403 BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
3404 spin_unlock_irqrestore(&lockres->l_lock, flags);
3405 ret = 0;
3406 goto leave;
3407 }
3408
3409 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
3410 /* XXX
3411 * This is a *big* race. The OCFS2_LOCK_PENDING flag
3412 * exists entirely for one reason - another thread has set
3413 * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock().
3414 *
3415 * If we do ocfs2_cancel_convert() before the other thread
3416 * calls dlm_lock(), our cancel will do nothing. We will
3417 * get no ast, and we will have no way of knowing the
3418 * cancel failed. Meanwhile, the other thread will call
3419 * into dlm_lock() and wait...forever.
3420 *
3421 * Why forever? Because another node has asked for the
3422 * lock first; that's why we're here in unblock_lock().
3423 *
3424 * The solution is OCFS2_LOCK_PENDING. When PENDING is
3425 * set, we just requeue the unblock. Only when the other
3426 * thread has called dlm_lock() and cleared PENDING will
3427 * we then cancel their request.
3428 *
3429 * All callers of dlm_lock() must set OCFS2_DLM_PENDING
3430 * at the same time they set OCFS2_DLM_BUSY. They must
3431 * clear OCFS2_DLM_PENDING after dlm_lock() returns.
3432 */
3433 if (lockres->l_flags & OCFS2_LOCK_PENDING) {
3434 mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
3435 lockres->l_name);
3436 goto leave_requeue;
3437 }
3438
3439 ctl->requeue = 1;
3440 ret = ocfs2_prepare_cancel_convert(osb, lockres);
3441 spin_unlock_irqrestore(&lockres->l_lock, flags);
3442 if (ret) {
3443 ret = ocfs2_cancel_convert(osb, lockres);
3444 if (ret < 0)
3445 mlog_errno(ret);
3446 }
3447 goto leave;
3448 }
3449
3450 /*
3451 * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is
3452 * set when the ast is received for an upconvert just before the
3453 * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast
3454 * on the heels of the ast, we want to delay the downconvert just
3455 * enough to allow the up requestor to do its task. Because this
3456 * lock is in the blocked queue, the lock will be downconverted
3457 * as soon as the requestor is done with the lock.
3458 */
3459 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING)
3460 goto leave_requeue;
3461
3462 /*
3463 * How can we block and yet be at NL? We were trying to upconvert
3464 * from NL and got canceled. The code comes back here, and now
3465 * we notice and clear BLOCKING.
3466 */
3467 if (lockres->l_level == DLM_LOCK_NL) {
3468 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
3469 mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
3470 lockres->l_blocking = DLM_LOCK_NL;
3471 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
3472 spin_unlock_irqrestore(&lockres->l_lock, flags);
3473 goto leave;
3474 }
3475
3476 /* if we're blocking an exclusive and we have *any* holders,
3477 * then requeue. */
3478 if ((lockres->l_blocking == DLM_LOCK_EX)
3479 && (lockres->l_ex_holders || lockres->l_ro_holders)) {
3480 mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
3481 lockres->l_name, lockres->l_ex_holders,
3482 lockres->l_ro_holders);
3483 goto leave_requeue;
3484 }
3485
3486 /* If it's a PR we're blocking, then only
3487 * requeue if we've got any EX holders */
3488 if (lockres->l_blocking == DLM_LOCK_PR &&
3489 lockres->l_ex_holders) {
3490 mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
3491 lockres->l_name, lockres->l_ex_holders);
3492 goto leave_requeue;
3493 }
3494
3495 /*
3496 * Can we get a lock in this state if the holder counts are
3497 * zero? The meta data unblock code used to check this.
3498 */
3499 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
3500 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
3501 mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
3502 lockres->l_name);
3503 goto leave_requeue;
3504 }
3505
3506 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
3507
3508 if (lockres->l_ops->check_downconvert
3509 && !lockres->l_ops->check_downconvert(lockres, new_level)) {
3510 mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
3511 lockres->l_name);
3512 goto leave_requeue;
3513 }
3514
3515 /* If we get here, then we know that there are no more
3516 * incompatible holders (and anyone asking for an incompatible
3517 * lock is blocked). We can now downconvert the lock */
3518 if (!lockres->l_ops->downconvert_worker)
3519 goto downconvert;
3520
3521 /* Some lockres types want to do a bit of work before
3522 * downconverting a lock. Allow that here. The worker function
3523 * may sleep, so we save off a copy of what we're blocking as
3524 * it may change while we're not holding the spin lock. */
3525 blocking = lockres->l_blocking;
3526 level = lockres->l_level;
3527 spin_unlock_irqrestore(&lockres->l_lock, flags);
3528
3529 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
3530
3531 if (ctl->unblock_action == UNBLOCK_STOP_POST) {
3532 mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
3533 lockres->l_name);
3534 goto leave;
3535 }
3536
3537 spin_lock_irqsave(&lockres->l_lock, flags);
3538 if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
3539 /* If this changed underneath us, then we can't drop
3540 * it just yet. */
3541 mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
3542 "Recheck\n", lockres->l_name, blocking,
3543 lockres->l_blocking, level, lockres->l_level);
3544 goto recheck;
3545 }
3546
3547downconvert:
3548 ctl->requeue = 0;
3549
3550 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
3551 if (lockres->l_level == DLM_LOCK_EX)
3552 set_lvb = 1;
3553
3554 /*
3555 * We only set the lvb if the lock has been fully
3556 * refreshed - otherwise we risk setting stale
3557 * data. Otherwise, there's no need to actually clear
3558 * out the lvb here as it's value is still valid.
3559 */
3560 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
3561 lockres->l_ops->set_lvb(lockres);
3562 }
3563
3564 gen = ocfs2_prepare_downconvert(lockres, new_level);
3565 spin_unlock_irqrestore(&lockres->l_lock, flags);
3566 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
3567 gen);
3568
3569leave:
3570 if (ret)
3571 mlog_errno(ret);
3572 return ret;
3573
3574leave_requeue:
3575 spin_unlock_irqrestore(&lockres->l_lock, flags);
3576 ctl->requeue = 1;
3577
3578 return 0;
3579}
3580
3581static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
3582 int blocking)
3583{
3584 struct inode *inode;
3585 struct address_space *mapping;
3586 struct ocfs2_inode_info *oi;
3587
3588 inode = ocfs2_lock_res_inode(lockres);
3589 mapping = inode->i_mapping;
3590
3591 if (S_ISDIR(inode->i_mode)) {
3592 oi = OCFS2_I(inode);
3593 oi->ip_dir_lock_gen++;
3594 mlog(0, "generation: %u\n", oi->ip_dir_lock_gen);
3595 goto out;
3596 }
3597
3598 if (!S_ISREG(inode->i_mode))
3599 goto out;
3600
3601 /*
3602 * We need this before the filemap_fdatawrite() so that it can
3603 * transfer the dirty bit from the PTE to the
3604 * page. Unfortunately this means that even for EX->PR
3605 * downconverts, we'll lose our mappings and have to build
3606 * them up again.
3607 */
3608 unmap_mapping_range(mapping, 0, 0, 0);
3609
3610 if (filemap_fdatawrite(mapping)) {
3611 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
3612 (unsigned long long)OCFS2_I(inode)->ip_blkno);
3613 }
3614 sync_mapping_buffers(mapping);
3615 if (blocking == DLM_LOCK_EX) {
3616 truncate_inode_pages(mapping, 0);
3617 } else {
3618 /* We only need to wait on the I/O if we're not also
3619 * truncating pages because truncate_inode_pages waits
3620 * for us above. We don't truncate pages if we're
3621 * blocking anything < EXMODE because we want to keep
3622 * them around in that case. */
3623 filemap_fdatawait(mapping);
3624 }
3625
3626 forget_all_cached_acls(inode);
3627
3628out:
3629 return UNBLOCK_CONTINUE;
3630}
3631
3632static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci,
3633 struct ocfs2_lock_res *lockres,
3634 int new_level)
3635{
3636 int checkpointed = ocfs2_ci_fully_checkpointed(ci);
3637
3638 BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
3639 BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
3640
3641 if (checkpointed)
3642 return 1;
3643
3644 ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci)));
3645 return 0;
3646}
3647
3648static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
3649 int new_level)
3650{
3651 struct inode *inode = ocfs2_lock_res_inode(lockres);
3652
3653 return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level);
3654}
3655
3656static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
3657{
3658 struct inode *inode = ocfs2_lock_res_inode(lockres);
3659
3660 __ocfs2_stuff_meta_lvb(inode);
3661}
3662
3663/*
3664 * Does the final reference drop on our dentry lock. Right now this
3665 * happens in the downconvert thread, but we could choose to simplify the
3666 * dlmglue API and push these off to the ocfs2_wq in the future.
3667 */
3668static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
3669 struct ocfs2_lock_res *lockres)
3670{
3671 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
3672 ocfs2_dentry_lock_put(osb, dl);
3673}
3674
3675/*
3676 * d_delete() matching dentries before the lock downconvert.
3677 *
3678 * At this point, any process waiting to destroy the
3679 * dentry_lock due to last ref count is stopped by the
3680 * OCFS2_LOCK_QUEUED flag.
3681 *
3682 * We have two potential problems
3683 *
3684 * 1) If we do the last reference drop on our dentry_lock (via dput)
3685 * we'll wind up in ocfs2_release_dentry_lock(), waiting on
3686 * the downconvert to finish. Instead we take an elevated
3687 * reference and push the drop until after we've completed our
3688 * unblock processing.
3689 *
3690 * 2) There might be another process with a final reference,
3691 * waiting on us to finish processing. If this is the case, we
3692 * detect it and exit out - there's no more dentries anyway.
3693 */
3694static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
3695 int blocking)
3696{
3697 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
3698 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
3699 struct dentry *dentry;
3700 unsigned long flags;
3701 int extra_ref = 0;
3702
3703 /*
3704 * This node is blocking another node from getting a read
3705 * lock. This happens when we've renamed within a
3706 * directory. We've forced the other nodes to d_delete(), but
3707 * we never actually dropped our lock because it's still
3708 * valid. The downconvert code will retain a PR for this node,
3709 * so there's no further work to do.
3710 */
3711 if (blocking == DLM_LOCK_PR)
3712 return UNBLOCK_CONTINUE;
3713
3714 /*
3715 * Mark this inode as potentially orphaned. The code in
3716 * ocfs2_delete_inode() will figure out whether it actually
3717 * needs to be freed or not.
3718 */
3719 spin_lock(&oi->ip_lock);
3720 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
3721 spin_unlock(&oi->ip_lock);
3722
3723 /*
3724 * Yuck. We need to make sure however that the check of
3725 * OCFS2_LOCK_FREEING and the extra reference are atomic with
3726 * respect to a reference decrement or the setting of that
3727 * flag.
3728 */
3729 spin_lock_irqsave(&lockres->l_lock, flags);
3730 spin_lock(&dentry_attach_lock);
3731 if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
3732 && dl->dl_count) {
3733 dl->dl_count++;
3734 extra_ref = 1;
3735 }
3736 spin_unlock(&dentry_attach_lock);
3737 spin_unlock_irqrestore(&lockres->l_lock, flags);
3738
3739 mlog(0, "extra_ref = %d\n", extra_ref);
3740
3741 /*
3742 * We have a process waiting on us in ocfs2_dentry_iput(),
3743 * which means we can't have any more outstanding
3744 * aliases. There's no need to do any more work.
3745 */
3746 if (!extra_ref)
3747 return UNBLOCK_CONTINUE;
3748
3749 spin_lock(&dentry_attach_lock);
3750 while (1) {
3751 dentry = ocfs2_find_local_alias(dl->dl_inode,
3752 dl->dl_parent_blkno, 1);
3753 if (!dentry)
3754 break;
3755 spin_unlock(&dentry_attach_lock);
3756
3757 if (S_ISDIR(dl->dl_inode->i_mode))
3758 shrink_dcache_parent(dentry);
3759
3760 mlog(0, "d_delete(%pd);\n", dentry);
3761
3762 /*
3763 * The following dcache calls may do an
3764 * iput(). Normally we don't want that from the
3765 * downconverting thread, but in this case it's ok
3766 * because the requesting node already has an
3767 * exclusive lock on the inode, so it can't be queued
3768 * for a downconvert.
3769 */
3770 d_delete(dentry);
3771 dput(dentry);
3772
3773 spin_lock(&dentry_attach_lock);
3774 }
3775 spin_unlock(&dentry_attach_lock);
3776
3777 /*
3778 * If we are the last holder of this dentry lock, there is no
3779 * reason to downconvert so skip straight to the unlock.
3780 */
3781 if (dl->dl_count == 1)
3782 return UNBLOCK_STOP_POST;
3783
3784 return UNBLOCK_CONTINUE_POST;
3785}
3786
3787static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
3788 int new_level)
3789{
3790 struct ocfs2_refcount_tree *tree =
3791 ocfs2_lock_res_refcount_tree(lockres);
3792
3793 return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level);
3794}
3795
3796static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
3797 int blocking)
3798{
3799 struct ocfs2_refcount_tree *tree =
3800 ocfs2_lock_res_refcount_tree(lockres);
3801
3802 ocfs2_metadata_cache_purge(&tree->rf_ci);
3803
3804 return UNBLOCK_CONTINUE;
3805}
3806
3807static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
3808{
3809 struct ocfs2_qinfo_lvb *lvb;
3810 struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
3811 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
3812 oinfo->dqi_gi.dqi_type);
3813
3814 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
3815 lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
3816 lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
3817 lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
3818 lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
3819 lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
3820 lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
3821 lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
3822}
3823
3824void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
3825{
3826 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
3827 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
3828 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
3829
3830 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
3831 ocfs2_cluster_unlock(osb, lockres, level);
3832}
3833
3834static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
3835{
3836 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
3837 oinfo->dqi_gi.dqi_type);
3838 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
3839 struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
3840 struct buffer_head *bh = NULL;
3841 struct ocfs2_global_disk_dqinfo *gdinfo;
3842 int status = 0;
3843
3844 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
3845 lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
3846 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
3847 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
3848 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
3849 oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
3850 oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
3851 oinfo->dqi_gi.dqi_free_entry =
3852 be32_to_cpu(lvb->lvb_free_entry);
3853 } else {
3854 status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode,
3855 oinfo->dqi_giblk, &bh);
3856 if (status) {
3857 mlog_errno(status);
3858 goto bail;
3859 }
3860 gdinfo = (struct ocfs2_global_disk_dqinfo *)
3861 (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
3862 info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
3863 info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
3864 oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
3865 oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
3866 oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
3867 oinfo->dqi_gi.dqi_free_entry =
3868 le32_to_cpu(gdinfo->dqi_free_entry);
3869 brelse(bh);
3870 ocfs2_track_lock_refresh(lockres);
3871 }
3872
3873bail:
3874 return status;
3875}
3876
3877/* Lock quota info, this function expects at least shared lock on the quota file
3878 * so that we can safely refresh quota info from disk. */
3879int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
3880{
3881 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
3882 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
3883 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
3884 int status = 0;
3885
3886 /* On RO devices, locking really isn't needed... */
3887 if (ocfs2_is_hard_readonly(osb)) {
3888 if (ex)
3889 status = -EROFS;
3890 goto bail;
3891 }
3892 if (ocfs2_mount_local(osb))
3893 goto bail;
3894
3895 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
3896 if (status < 0) {
3897 mlog_errno(status);
3898 goto bail;
3899 }
3900 if (!ocfs2_should_refresh_lock_res(lockres))
3901 goto bail;
3902 /* OK, we have the lock but we need to refresh the quota info */
3903 status = ocfs2_refresh_qinfo(oinfo);
3904 if (status)
3905 ocfs2_qinfo_unlock(oinfo, ex);
3906 ocfs2_complete_lock_res_refresh(lockres, status);
3907bail:
3908 return status;
3909}
3910
3911int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex)
3912{
3913 int status;
3914 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
3915 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
3916 struct ocfs2_super *osb = lockres->l_priv;
3917
3918
3919 if (ocfs2_is_hard_readonly(osb))
3920 return -EROFS;
3921
3922 if (ocfs2_mount_local(osb))
3923 return 0;
3924
3925 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
3926 if (status < 0)
3927 mlog_errno(status);
3928
3929 return status;
3930}
3931
3932void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
3933{
3934 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
3935 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
3936 struct ocfs2_super *osb = lockres->l_priv;
3937
3938 if (!ocfs2_mount_local(osb))
3939 ocfs2_cluster_unlock(osb, lockres, level);
3940}
3941
3942static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3943 struct ocfs2_lock_res *lockres)
3944{
3945 int status;
3946 struct ocfs2_unblock_ctl ctl = {0, 0,};
3947 unsigned long flags;
3948
3949 /* Our reference to the lockres in this function can be
3950 * considered valid until we remove the OCFS2_LOCK_QUEUED
3951 * flag. */
3952
3953 BUG_ON(!lockres);
3954 BUG_ON(!lockres->l_ops);
3955
3956 mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
3957
3958 /* Detect whether a lock has been marked as going away while
3959 * the downconvert thread was processing other things. A lock can
3960 * still be marked with OCFS2_LOCK_FREEING after this check,
3961 * but short circuiting here will still save us some
3962 * performance. */
3963 spin_lock_irqsave(&lockres->l_lock, flags);
3964 if (lockres->l_flags & OCFS2_LOCK_FREEING)
3965 goto unqueue;
3966 spin_unlock_irqrestore(&lockres->l_lock, flags);
3967
3968 status = ocfs2_unblock_lock(osb, lockres, &ctl);
3969 if (status < 0)
3970 mlog_errno(status);
3971
3972 spin_lock_irqsave(&lockres->l_lock, flags);
3973unqueue:
3974 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
3975 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
3976 } else
3977 ocfs2_schedule_blocked_lock(osb, lockres);
3978
3979 mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
3980 ctl.requeue ? "yes" : "no");
3981 spin_unlock_irqrestore(&lockres->l_lock, flags);
3982
3983 if (ctl.unblock_action != UNBLOCK_CONTINUE
3984 && lockres->l_ops->post_unlock)
3985 lockres->l_ops->post_unlock(osb, lockres);
3986}
3987
3988static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
3989 struct ocfs2_lock_res *lockres)
3990{
3991 unsigned long flags;
3992
3993 assert_spin_locked(&lockres->l_lock);
3994
3995 if (lockres->l_flags & OCFS2_LOCK_FREEING) {
3996 /* Do not schedule a lock for downconvert when it's on
3997 * the way to destruction - any nodes wanting access
3998 * to the resource will get it soon. */
3999 mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
4000 lockres->l_name, lockres->l_flags);
4001 return;
4002 }
4003
4004 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
4005
4006 spin_lock_irqsave(&osb->dc_task_lock, flags);
4007 if (list_empty(&lockres->l_blocked_list)) {
4008 list_add_tail(&lockres->l_blocked_list,
4009 &osb->blocked_lock_list);
4010 osb->blocked_lock_count++;
4011 }
4012 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4013}
4014
4015static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
4016{
4017 unsigned long processed;
4018 unsigned long flags;
4019 struct ocfs2_lock_res *lockres;
4020
4021 spin_lock_irqsave(&osb->dc_task_lock, flags);
4022 /* grab this early so we know to try again if a state change and
4023 * wake happens part-way through our work */
4024 osb->dc_work_sequence = osb->dc_wake_sequence;
4025
4026 processed = osb->blocked_lock_count;
4027 /*
4028 * blocked lock processing in this loop might call iput which can
4029 * remove items off osb->blocked_lock_list. Downconvert up to
4030 * 'processed' number of locks, but stop short if we had some
4031 * removed in ocfs2_mark_lockres_freeing when downconverting.
4032 */
4033 while (processed && !list_empty(&osb->blocked_lock_list)) {
4034 lockres = list_entry(osb->blocked_lock_list.next,
4035 struct ocfs2_lock_res, l_blocked_list);
4036 list_del_init(&lockres->l_blocked_list);
4037 osb->blocked_lock_count--;
4038 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4039
4040 BUG_ON(!processed);
4041 processed--;
4042
4043 ocfs2_process_blocked_lock(osb, lockres);
4044
4045 spin_lock_irqsave(&osb->dc_task_lock, flags);
4046 }
4047 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4048}
4049
4050static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
4051{
4052 int empty = 0;
4053 unsigned long flags;
4054
4055 spin_lock_irqsave(&osb->dc_task_lock, flags);
4056 if (list_empty(&osb->blocked_lock_list))
4057 empty = 1;
4058
4059 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4060 return empty;
4061}
4062
4063static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
4064{
4065 int should_wake = 0;
4066 unsigned long flags;
4067
4068 spin_lock_irqsave(&osb->dc_task_lock, flags);
4069 if (osb->dc_work_sequence != osb->dc_wake_sequence)
4070 should_wake = 1;
4071 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4072
4073 return should_wake;
4074}
4075
4076static int ocfs2_downconvert_thread(void *arg)
4077{
4078 int status = 0;
4079 struct ocfs2_super *osb = arg;
4080
4081 /* only quit once we've been asked to stop and there is no more
4082 * work available */
4083 while (!(kthread_should_stop() &&
4084 ocfs2_downconvert_thread_lists_empty(osb))) {
4085
4086 wait_event_interruptible(osb->dc_event,
4087 ocfs2_downconvert_thread_should_wake(osb) ||
4088 kthread_should_stop());
4089
4090 mlog(0, "downconvert_thread: awoken\n");
4091
4092 ocfs2_downconvert_thread_do_work(osb);
4093 }
4094
4095 osb->dc_task = NULL;
4096 return status;
4097}
4098
4099void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
4100{
4101 unsigned long flags;
4102
4103 spin_lock_irqsave(&osb->dc_task_lock, flags);
4104 /* make sure the voting thread gets a swipe at whatever changes
4105 * the caller may have made to the voting state */
4106 osb->dc_wake_sequence++;
4107 spin_unlock_irqrestore(&osb->dc_task_lock, flags);
4108 wake_up(&osb->dc_event);
4109}
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 const struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
225 .get_osb = ocfs2_get_inode_osb,
226 .flags = 0,
227};
228
229static const 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 const struct ocfs2_lock_res_ops ocfs2_super_lops = {
238 .flags = LOCK_TYPE_REQUIRES_REFRESH,
239};
240
241static const struct ocfs2_lock_res_ops ocfs2_rename_lops = {
242 .flags = 0,
243};
244
245static const struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
246 .flags = 0,
247};
248
249static const struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
250 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
251};
252
253static const struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
254 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
255};
256
257static const 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 const struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
265 .get_osb = ocfs2_get_inode_osb,
266 .flags = 0,
267};
268
269static const struct ocfs2_lock_res_ops ocfs2_flock_lops = {
270 .get_osb = ocfs2_get_file_osb,
271 .flags = 0,
272};
273
274static const 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 const 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 const 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 const 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 request 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 struct timespec64 ts;
2166
2167 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2168
2169 /*
2170 * Invalidate the LVB of a deleted inode - this way other
2171 * nodes are forced to go to disk and discover the new inode
2172 * status.
2173 */
2174 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2175 lvb->lvb_version = 0;
2176 goto out;
2177 }
2178
2179 lvb->lvb_version = OCFS2_LVB_VERSION;
2180 lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
2181 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
2182 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode));
2183 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
2184 lvb->lvb_imode = cpu_to_be16(inode->i_mode);
2185 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
2186 ts = inode_get_atime(inode);
2187 lvb->lvb_iatime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts));
2188 ts = inode_get_ctime(inode);
2189 lvb->lvb_ictime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts));
2190 ts = inode_get_mtime(inode);
2191 lvb->lvb_imtime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts));
2192 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
2193 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
2194 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
2195
2196out:
2197 mlog_meta_lvb(0, lockres);
2198}
2199
2200static void ocfs2_unpack_timespec(struct timespec64 *spec,
2201 u64 packed_time)
2202{
2203 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
2204 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
2205}
2206
2207static int ocfs2_refresh_inode_from_lvb(struct inode *inode)
2208{
2209 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2210 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2211 struct ocfs2_meta_lvb *lvb;
2212 struct timespec64 ts;
2213
2214 mlog_meta_lvb(0, lockres);
2215
2216 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2217 if (inode_wrong_type(inode, be16_to_cpu(lvb->lvb_imode)))
2218 return -ESTALE;
2219
2220 /* We're safe here without the lockres lock... */
2221 spin_lock(&oi->ip_lock);
2222 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
2223 i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
2224
2225 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
2226 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
2227 ocfs2_set_inode_flags(inode);
2228
2229 /* fast-symlinks are a special case */
2230 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
2231 inode->i_blocks = 0;
2232 else
2233 inode->i_blocks = ocfs2_inode_sector_count(inode);
2234
2235 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid));
2236 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
2237 inode->i_mode = be16_to_cpu(lvb->lvb_imode);
2238 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
2239 ocfs2_unpack_timespec(&ts, be64_to_cpu(lvb->lvb_iatime_packed));
2240 inode_set_atime_to_ts(inode, ts);
2241 ocfs2_unpack_timespec(&ts, be64_to_cpu(lvb->lvb_imtime_packed));
2242 inode_set_mtime_to_ts(inode, ts);
2243 ocfs2_unpack_timespec(&ts, be64_to_cpu(lvb->lvb_ictime_packed));
2244 inode_set_ctime_to_ts(inode, ts);
2245 spin_unlock(&oi->ip_lock);
2246 return 0;
2247}
2248
2249static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
2250 struct ocfs2_lock_res *lockres)
2251{
2252 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2253
2254 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
2255 && lvb->lvb_version == OCFS2_LVB_VERSION
2256 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
2257 return 1;
2258 return 0;
2259}
2260
2261/* Determine whether a lock resource needs to be refreshed, and
2262 * arbitrate who gets to refresh it.
2263 *
2264 * 0 means no refresh needed.
2265 *
2266 * > 0 means you need to refresh this and you MUST call
2267 * ocfs2_complete_lock_res_refresh afterwards. */
2268static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
2269{
2270 unsigned long flags;
2271 int status = 0;
2272
2273refresh_check:
2274 spin_lock_irqsave(&lockres->l_lock, flags);
2275 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
2276 spin_unlock_irqrestore(&lockres->l_lock, flags);
2277 goto bail;
2278 }
2279
2280 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
2281 spin_unlock_irqrestore(&lockres->l_lock, flags);
2282
2283 ocfs2_wait_on_refreshing_lock(lockres);
2284 goto refresh_check;
2285 }
2286
2287 /* Ok, I'll be the one to refresh this lock. */
2288 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
2289 spin_unlock_irqrestore(&lockres->l_lock, flags);
2290
2291 status = 1;
2292bail:
2293 mlog(0, "status %d\n", status);
2294 return status;
2295}
2296
2297/* If status is non zero, I'll mark it as not being in refresh
2298 * anymroe, but i won't clear the needs refresh flag. */
2299static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
2300 int status)
2301{
2302 unsigned long flags;
2303
2304 spin_lock_irqsave(&lockres->l_lock, flags);
2305 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
2306 if (!status)
2307 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
2308 spin_unlock_irqrestore(&lockres->l_lock, flags);
2309
2310 wake_up(&lockres->l_event);
2311}
2312
2313/* may or may not return a bh if it went to disk. */
2314static int ocfs2_inode_lock_update(struct inode *inode,
2315 struct buffer_head **bh)
2316{
2317 int status = 0;
2318 struct ocfs2_inode_info *oi = OCFS2_I(inode);
2319 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
2320 struct ocfs2_dinode *fe;
2321 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2322
2323 if (ocfs2_mount_local(osb))
2324 goto bail;
2325
2326 spin_lock(&oi->ip_lock);
2327 if (oi->ip_flags & OCFS2_INODE_DELETED) {
2328 mlog(0, "Orphaned inode %llu was deleted while we "
2329 "were waiting on a lock. ip_flags = 0x%x\n",
2330 (unsigned long long)oi->ip_blkno, oi->ip_flags);
2331 spin_unlock(&oi->ip_lock);
2332 status = -ENOENT;
2333 goto bail;
2334 }
2335 spin_unlock(&oi->ip_lock);
2336
2337 if (!ocfs2_should_refresh_lock_res(lockres))
2338 goto bail;
2339
2340 /* This will discard any caching information we might have had
2341 * for the inode metadata. */
2342 ocfs2_metadata_cache_purge(INODE_CACHE(inode));
2343
2344 ocfs2_extent_map_trunc(inode, 0);
2345
2346 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
2347 mlog(0, "Trusting LVB on inode %llu\n",
2348 (unsigned long long)oi->ip_blkno);
2349 status = ocfs2_refresh_inode_from_lvb(inode);
2350 goto bail_refresh;
2351 } else {
2352 /* Boo, we have to go to disk. */
2353 /* read bh, cast, ocfs2_refresh_inode */
2354 status = ocfs2_read_inode_block(inode, bh);
2355 if (status < 0) {
2356 mlog_errno(status);
2357 goto bail_refresh;
2358 }
2359 fe = (struct ocfs2_dinode *) (*bh)->b_data;
2360 if (inode_wrong_type(inode, le16_to_cpu(fe->i_mode))) {
2361 status = -ESTALE;
2362 goto bail_refresh;
2363 }
2364
2365 /* This is a good chance to make sure we're not
2366 * locking an invalid object. ocfs2_read_inode_block()
2367 * already checked that the inode block is sane.
2368 *
2369 * We bug on a stale inode here because we checked
2370 * above whether it was wiped from disk. The wiping
2371 * node provides a guarantee that we receive that
2372 * message and can mark the inode before dropping any
2373 * locks associated with it. */
2374 mlog_bug_on_msg(inode->i_generation !=
2375 le32_to_cpu(fe->i_generation),
2376 "Invalid dinode %llu disk generation: %u "
2377 "inode->i_generation: %u\n",
2378 (unsigned long long)oi->ip_blkno,
2379 le32_to_cpu(fe->i_generation),
2380 inode->i_generation);
2381 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
2382 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
2383 "Stale dinode %llu dtime: %llu flags: 0x%x\n",
2384 (unsigned long long)oi->ip_blkno,
2385 (unsigned long long)le64_to_cpu(fe->i_dtime),
2386 le32_to_cpu(fe->i_flags));
2387
2388 ocfs2_refresh_inode(inode, fe);
2389 ocfs2_track_lock_refresh(lockres);
2390 }
2391
2392 status = 0;
2393bail_refresh:
2394 ocfs2_complete_lock_res_refresh(lockres, status);
2395bail:
2396 return status;
2397}
2398
2399static int ocfs2_assign_bh(struct inode *inode,
2400 struct buffer_head **ret_bh,
2401 struct buffer_head *passed_bh)
2402{
2403 int status;
2404
2405 if (passed_bh) {
2406 /* Ok, the update went to disk for us, use the
2407 * returned bh. */
2408 *ret_bh = passed_bh;
2409 get_bh(*ret_bh);
2410
2411 return 0;
2412 }
2413
2414 status = ocfs2_read_inode_block(inode, ret_bh);
2415 if (status < 0)
2416 mlog_errno(status);
2417
2418 return status;
2419}
2420
2421/*
2422 * returns < 0 error if the callback will never be called, otherwise
2423 * the result of the lock will be communicated via the callback.
2424 */
2425int ocfs2_inode_lock_full_nested(struct inode *inode,
2426 struct buffer_head **ret_bh,
2427 int ex,
2428 int arg_flags,
2429 int subclass)
2430{
2431 int status, level, acquired;
2432 u32 dlm_flags;
2433 struct ocfs2_lock_res *lockres = NULL;
2434 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2435 struct buffer_head *local_bh = NULL;
2436
2437 mlog(0, "inode %llu, take %s META lock\n",
2438 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2439 ex ? "EXMODE" : "PRMODE");
2440
2441 status = 0;
2442 acquired = 0;
2443 /* We'll allow faking a readonly metadata lock for
2444 * rodevices. */
2445 if (ocfs2_is_hard_readonly(osb)) {
2446 if (ex)
2447 status = -EROFS;
2448 goto getbh;
2449 }
2450
2451 if ((arg_flags & OCFS2_META_LOCK_GETBH) ||
2452 ocfs2_mount_local(osb))
2453 goto update;
2454
2455 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2456 ocfs2_wait_for_recovery(osb);
2457
2458 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2459 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2460 dlm_flags = 0;
2461 if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
2462 dlm_flags |= DLM_LKF_NOQUEUE;
2463
2464 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
2465 arg_flags, subclass, _RET_IP_);
2466 if (status < 0) {
2467 if (status != -EAGAIN)
2468 mlog_errno(status);
2469 goto bail;
2470 }
2471
2472 /* Notify the error cleanup path to drop the cluster lock. */
2473 acquired = 1;
2474
2475 /* We wait twice because a node may have died while we were in
2476 * the lower dlm layers. The second time though, we've
2477 * committed to owning this lock so we don't allow signals to
2478 * abort the operation. */
2479 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
2480 ocfs2_wait_for_recovery(osb);
2481
2482update:
2483 /*
2484 * We only see this flag if we're being called from
2485 * ocfs2_read_locked_inode(). It means we're locking an inode
2486 * which hasn't been populated yet, so clear the refresh flag
2487 * and let the caller handle it.
2488 */
2489 if (inode->i_state & I_NEW) {
2490 status = 0;
2491 if (lockres)
2492 ocfs2_complete_lock_res_refresh(lockres, 0);
2493 goto bail;
2494 }
2495
2496 /* This is fun. The caller may want a bh back, or it may
2497 * not. ocfs2_inode_lock_update definitely wants one in, but
2498 * may or may not read one, depending on what's in the
2499 * LVB. The result of all of this is that we've *only* gone to
2500 * disk if we have to, so the complexity is worthwhile. */
2501 status = ocfs2_inode_lock_update(inode, &local_bh);
2502 if (status < 0) {
2503 if (status != -ENOENT)
2504 mlog_errno(status);
2505 goto bail;
2506 }
2507getbh:
2508 if (ret_bh) {
2509 status = ocfs2_assign_bh(inode, ret_bh, local_bh);
2510 if (status < 0) {
2511 mlog_errno(status);
2512 goto bail;
2513 }
2514 }
2515
2516bail:
2517 if (status < 0) {
2518 if (ret_bh && (*ret_bh)) {
2519 brelse(*ret_bh);
2520 *ret_bh = NULL;
2521 }
2522 if (acquired)
2523 ocfs2_inode_unlock(inode, ex);
2524 }
2525
2526 brelse(local_bh);
2527 return status;
2528}
2529
2530/*
2531 * This is working around a lock inversion between tasks acquiring DLM
2532 * locks while holding a page lock and the downconvert thread which
2533 * blocks dlm lock acquiry while acquiring page locks.
2534 *
2535 * ** These _with_page variantes are only intended to be called from aop
2536 * methods that hold page locks and return a very specific *positive* error
2537 * code that aop methods pass up to the VFS -- test for errors with != 0. **
2538 *
2539 * The DLM is called such that it returns -EAGAIN if it would have
2540 * blocked waiting for the downconvert thread. In that case we unlock
2541 * our page so the downconvert thread can make progress. Once we've
2542 * done this we have to return AOP_TRUNCATED_PAGE so the aop method
2543 * that called us can bubble that back up into the VFS who will then
2544 * immediately retry the aop call.
2545 */
2546int ocfs2_inode_lock_with_page(struct inode *inode,
2547 struct buffer_head **ret_bh,
2548 int ex,
2549 struct page *page)
2550{
2551 int ret;
2552
2553 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
2554 if (ret == -EAGAIN) {
2555 unlock_page(page);
2556 /*
2557 * If we can't get inode lock immediately, we should not return
2558 * directly here, since this will lead to a softlockup problem.
2559 * The method is to get a blocking lock and immediately unlock
2560 * before returning, this can avoid CPU resource waste due to
2561 * lots of retries, and benefits fairness in getting lock.
2562 */
2563 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
2564 ocfs2_inode_unlock(inode, ex);
2565 ret = AOP_TRUNCATED_PAGE;
2566 }
2567
2568 return ret;
2569}
2570
2571int ocfs2_inode_lock_atime(struct inode *inode,
2572 struct vfsmount *vfsmnt,
2573 int *level, int wait)
2574{
2575 int ret;
2576
2577 if (wait)
2578 ret = ocfs2_inode_lock(inode, NULL, 0);
2579 else
2580 ret = ocfs2_try_inode_lock(inode, NULL, 0);
2581
2582 if (ret < 0) {
2583 if (ret != -EAGAIN)
2584 mlog_errno(ret);
2585 return ret;
2586 }
2587
2588 /*
2589 * If we should update atime, we will get EX lock,
2590 * otherwise we just get PR lock.
2591 */
2592 if (ocfs2_should_update_atime(inode, vfsmnt)) {
2593 struct buffer_head *bh = NULL;
2594
2595 ocfs2_inode_unlock(inode, 0);
2596 if (wait)
2597 ret = ocfs2_inode_lock(inode, &bh, 1);
2598 else
2599 ret = ocfs2_try_inode_lock(inode, &bh, 1);
2600
2601 if (ret < 0) {
2602 if (ret != -EAGAIN)
2603 mlog_errno(ret);
2604 return ret;
2605 }
2606 *level = 1;
2607 if (ocfs2_should_update_atime(inode, vfsmnt))
2608 ocfs2_update_inode_atime(inode, bh);
2609 brelse(bh);
2610 } else
2611 *level = 0;
2612
2613 return ret;
2614}
2615
2616void ocfs2_inode_unlock(struct inode *inode,
2617 int ex)
2618{
2619 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2620 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
2621 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2622
2623 mlog(0, "inode %llu drop %s META lock\n",
2624 (unsigned long long)OCFS2_I(inode)->ip_blkno,
2625 ex ? "EXMODE" : "PRMODE");
2626
2627 if (!ocfs2_is_hard_readonly(osb) &&
2628 !ocfs2_mount_local(osb))
2629 ocfs2_cluster_unlock(osb, lockres, level);
2630}
2631
2632/*
2633 * This _tracker variantes are introduced to deal with the recursive cluster
2634 * locking issue. The idea is to keep track of a lock holder on the stack of
2635 * the current process. If there's a lock holder on the stack, we know the
2636 * task context is already protected by cluster locking. Currently, they're
2637 * used in some VFS entry routines.
2638 *
2639 * return < 0 on error, return == 0 if there's no lock holder on the stack
2640 * before this call, return == 1 if this call would be a recursive locking.
2641 * return == -1 if this lock attempt will cause an upgrade which is forbidden.
2642 *
2643 * When taking lock levels into account,we face some different situations.
2644 *
2645 * 1. no lock is held
2646 * In this case, just lock the inode as requested and return 0
2647 *
2648 * 2. We are holding a lock
2649 * For this situation, things diverges into several cases
2650 *
2651 * wanted holding what to do
2652 * ex ex see 2.1 below
2653 * ex pr see 2.2 below
2654 * pr ex see 2.1 below
2655 * pr pr see 2.1 below
2656 *
2657 * 2.1 lock level that is been held is compatible
2658 * with the wanted level, so no lock action will be tacken.
2659 *
2660 * 2.2 Otherwise, an upgrade is needed, but it is forbidden.
2661 *
2662 * Reason why upgrade within a process is forbidden is that
2663 * lock upgrade may cause dead lock. The following illustrates
2664 * how it happens.
2665 *
2666 * thread on node1 thread on node2
2667 * ocfs2_inode_lock_tracker(ex=0)
2668 *
2669 * <====== ocfs2_inode_lock_tracker(ex=1)
2670 *
2671 * ocfs2_inode_lock_tracker(ex=1)
2672 */
2673int ocfs2_inode_lock_tracker(struct inode *inode,
2674 struct buffer_head **ret_bh,
2675 int ex,
2676 struct ocfs2_lock_holder *oh)
2677{
2678 int status = 0;
2679 struct ocfs2_lock_res *lockres;
2680 struct ocfs2_lock_holder *tmp_oh;
2681 struct pid *pid = task_pid(current);
2682
2683
2684 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2685 tmp_oh = ocfs2_pid_holder(lockres, pid);
2686
2687 if (!tmp_oh) {
2688 /*
2689 * This corresponds to the case 1.
2690 * We haven't got any lock before.
2691 */
2692 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0);
2693 if (status < 0) {
2694 if (status != -ENOENT)
2695 mlog_errno(status);
2696 return status;
2697 }
2698
2699 oh->oh_ex = ex;
2700 ocfs2_add_holder(lockres, oh);
2701 return 0;
2702 }
2703
2704 if (unlikely(ex && !tmp_oh->oh_ex)) {
2705 /*
2706 * case 2.2 upgrade may cause dead lock, forbid it.
2707 */
2708 mlog(ML_ERROR, "Recursive locking is not permitted to "
2709 "upgrade to EX level from PR level.\n");
2710 dump_stack();
2711 return -EINVAL;
2712 }
2713
2714 /*
2715 * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full.
2716 * ignore the lock level and just update it.
2717 */
2718 if (ret_bh) {
2719 status = ocfs2_inode_lock_full(inode, ret_bh, ex,
2720 OCFS2_META_LOCK_GETBH);
2721 if (status < 0) {
2722 if (status != -ENOENT)
2723 mlog_errno(status);
2724 return status;
2725 }
2726 }
2727 return 1;
2728}
2729
2730void ocfs2_inode_unlock_tracker(struct inode *inode,
2731 int ex,
2732 struct ocfs2_lock_holder *oh,
2733 int had_lock)
2734{
2735 struct ocfs2_lock_res *lockres;
2736
2737 lockres = &OCFS2_I(inode)->ip_inode_lockres;
2738 /* had_lock means that the currect process already takes the cluster
2739 * lock previously.
2740 * If had_lock is 1, we have nothing to do here.
2741 * If had_lock is 0, we will release the lock.
2742 */
2743 if (!had_lock) {
2744 ocfs2_inode_unlock(inode, oh->oh_ex);
2745 ocfs2_remove_holder(lockres, oh);
2746 }
2747}
2748
2749int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
2750{
2751 struct ocfs2_lock_res *lockres;
2752 struct ocfs2_orphan_scan_lvb *lvb;
2753 int status = 0;
2754
2755 if (ocfs2_is_hard_readonly(osb))
2756 return -EROFS;
2757
2758 if (ocfs2_mount_local(osb))
2759 return 0;
2760
2761 lockres = &osb->osb_orphan_scan.os_lockres;
2762 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2763 if (status < 0)
2764 return status;
2765
2766 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2767 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2768 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
2769 *seqno = be32_to_cpu(lvb->lvb_os_seqno);
2770 else
2771 *seqno = osb->osb_orphan_scan.os_seqno + 1;
2772
2773 return status;
2774}
2775
2776void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
2777{
2778 struct ocfs2_lock_res *lockres;
2779 struct ocfs2_orphan_scan_lvb *lvb;
2780
2781 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
2782 lockres = &osb->osb_orphan_scan.os_lockres;
2783 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2784 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
2785 lvb->lvb_os_seqno = cpu_to_be32(seqno);
2786 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2787 }
2788}
2789
2790int ocfs2_super_lock(struct ocfs2_super *osb,
2791 int ex)
2792{
2793 int status = 0;
2794 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2795 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2796
2797 if (ocfs2_is_hard_readonly(osb))
2798 return -EROFS;
2799
2800 if (ocfs2_mount_local(osb))
2801 goto bail;
2802
2803 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
2804 if (status < 0) {
2805 mlog_errno(status);
2806 goto bail;
2807 }
2808
2809 /* The super block lock path is really in the best position to
2810 * know when resources covered by the lock need to be
2811 * refreshed, so we do it here. Of course, making sense of
2812 * everything is up to the caller :) */
2813 status = ocfs2_should_refresh_lock_res(lockres);
2814 if (status) {
2815 status = ocfs2_refresh_slot_info(osb);
2816
2817 ocfs2_complete_lock_res_refresh(lockres, status);
2818
2819 if (status < 0) {
2820 ocfs2_cluster_unlock(osb, lockres, level);
2821 mlog_errno(status);
2822 }
2823 ocfs2_track_lock_refresh(lockres);
2824 }
2825bail:
2826 return status;
2827}
2828
2829void ocfs2_super_unlock(struct ocfs2_super *osb,
2830 int ex)
2831{
2832 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2833 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2834
2835 if (!ocfs2_mount_local(osb))
2836 ocfs2_cluster_unlock(osb, lockres, level);
2837}
2838
2839int ocfs2_rename_lock(struct ocfs2_super *osb)
2840{
2841 int status;
2842 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2843
2844 if (ocfs2_is_hard_readonly(osb))
2845 return -EROFS;
2846
2847 if (ocfs2_mount_local(osb))
2848 return 0;
2849
2850 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
2851 if (status < 0)
2852 mlog_errno(status);
2853
2854 return status;
2855}
2856
2857void ocfs2_rename_unlock(struct ocfs2_super *osb)
2858{
2859 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2860
2861 if (!ocfs2_mount_local(osb))
2862 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2863}
2864
2865int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
2866{
2867 int status;
2868 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2869
2870 if (ocfs2_is_hard_readonly(osb))
2871 return -EROFS;
2872
2873 if (ex)
2874 down_write(&osb->nfs_sync_rwlock);
2875 else
2876 down_read(&osb->nfs_sync_rwlock);
2877
2878 if (ocfs2_mount_local(osb))
2879 return 0;
2880
2881 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
2882 0, 0);
2883 if (status < 0) {
2884 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
2885
2886 if (ex)
2887 up_write(&osb->nfs_sync_rwlock);
2888 else
2889 up_read(&osb->nfs_sync_rwlock);
2890 }
2891
2892 return status;
2893}
2894
2895void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
2896{
2897 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
2898
2899 if (!ocfs2_mount_local(osb))
2900 ocfs2_cluster_unlock(osb, lockres,
2901 ex ? LKM_EXMODE : LKM_PRMODE);
2902 if (ex)
2903 up_write(&osb->nfs_sync_rwlock);
2904 else
2905 up_read(&osb->nfs_sync_rwlock);
2906}
2907
2908int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
2909 struct ocfs2_trim_fs_info *info, int trylock)
2910{
2911 int status;
2912 struct ocfs2_trim_fs_lvb *lvb;
2913 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2914
2915 if (info)
2916 info->tf_valid = 0;
2917
2918 if (ocfs2_is_hard_readonly(osb))
2919 return -EROFS;
2920
2921 if (ocfs2_mount_local(osb))
2922 return 0;
2923
2924 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX,
2925 trylock ? DLM_LKF_NOQUEUE : 0, 0);
2926 if (status < 0) {
2927 if (status != -EAGAIN)
2928 mlog_errno(status);
2929 return status;
2930 }
2931
2932 if (info) {
2933 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2934 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
2935 lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) {
2936 info->tf_valid = 1;
2937 info->tf_success = lvb->lvb_success;
2938 info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum);
2939 info->tf_start = be64_to_cpu(lvb->lvb_start);
2940 info->tf_len = be64_to_cpu(lvb->lvb_len);
2941 info->tf_minlen = be64_to_cpu(lvb->lvb_minlen);
2942 info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen);
2943 }
2944 }
2945
2946 return status;
2947}
2948
2949void ocfs2_trim_fs_unlock(struct ocfs2_super *osb,
2950 struct ocfs2_trim_fs_info *info)
2951{
2952 struct ocfs2_trim_fs_lvb *lvb;
2953 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
2954
2955 if (ocfs2_mount_local(osb))
2956 return;
2957
2958 if (info) {
2959 lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
2960 lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION;
2961 lvb->lvb_success = info->tf_success;
2962 lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum);
2963 lvb->lvb_start = cpu_to_be64(info->tf_start);
2964 lvb->lvb_len = cpu_to_be64(info->tf_len);
2965 lvb->lvb_minlen = cpu_to_be64(info->tf_minlen);
2966 lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen);
2967 }
2968
2969 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
2970}
2971
2972int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2973{
2974 int ret;
2975 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
2976 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2977 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2978
2979 BUG_ON(!dl);
2980
2981 if (ocfs2_is_hard_readonly(osb)) {
2982 if (ex)
2983 return -EROFS;
2984 return 0;
2985 }
2986
2987 if (ocfs2_mount_local(osb))
2988 return 0;
2989
2990 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2991 if (ret < 0)
2992 mlog_errno(ret);
2993
2994 return ret;
2995}
2996
2997void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2998{
2999 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
3000 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
3001 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
3002
3003 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
3004 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
3005}
3006
3007/* Reference counting of the dlm debug structure. We want this because
3008 * open references on the debug inodes can live on after a mount, so
3009 * we can't rely on the ocfs2_super to always exist. */
3010static void ocfs2_dlm_debug_free(struct kref *kref)
3011{
3012 struct ocfs2_dlm_debug *dlm_debug;
3013
3014 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
3015
3016 kfree(dlm_debug);
3017}
3018
3019void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
3020{
3021 if (dlm_debug)
3022 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
3023}
3024
3025static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
3026{
3027 kref_get(&debug->d_refcnt);
3028}
3029
3030struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
3031{
3032 struct ocfs2_dlm_debug *dlm_debug;
3033
3034 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
3035 if (!dlm_debug) {
3036 mlog_errno(-ENOMEM);
3037 goto out;
3038 }
3039
3040 kref_init(&dlm_debug->d_refcnt);
3041 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
3042 dlm_debug->d_filter_secs = 0;
3043out:
3044 return dlm_debug;
3045}
3046
3047/* Access to this is arbitrated for us via seq_file->sem. */
3048struct ocfs2_dlm_seq_priv {
3049 struct ocfs2_dlm_debug *p_dlm_debug;
3050 struct ocfs2_lock_res p_iter_res;
3051 struct ocfs2_lock_res p_tmp_res;
3052};
3053
3054static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
3055 struct ocfs2_dlm_seq_priv *priv)
3056{
3057 struct ocfs2_lock_res *iter, *ret = NULL;
3058 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
3059
3060 assert_spin_locked(&ocfs2_dlm_tracking_lock);
3061
3062 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
3063 /* discover the head of the list */
3064 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
3065 mlog(0, "End of list found, %p\n", ret);
3066 break;
3067 }
3068
3069 /* We track our "dummy" iteration lockres' by a NULL
3070 * l_ops field. */
3071 if (iter->l_ops != NULL) {
3072 ret = iter;
3073 break;
3074 }
3075 }
3076
3077 return ret;
3078}
3079
3080static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
3081{
3082 struct ocfs2_dlm_seq_priv *priv = m->private;
3083 struct ocfs2_lock_res *iter;
3084
3085 spin_lock(&ocfs2_dlm_tracking_lock);
3086 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
3087 if (iter) {
3088 /* Since lockres' have the lifetime of their container
3089 * (which can be inodes, ocfs2_supers, etc) we want to
3090 * copy this out to a temporary lockres while still
3091 * under the spinlock. Obviously after this we can't
3092 * trust any pointers on the copy returned, but that's
3093 * ok as the information we want isn't typically held
3094 * in them. */
3095 priv->p_tmp_res = *iter;
3096 iter = &priv->p_tmp_res;
3097 }
3098 spin_unlock(&ocfs2_dlm_tracking_lock);
3099
3100 return iter;
3101}
3102
3103static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
3104{
3105}
3106
3107static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
3108{
3109 struct ocfs2_dlm_seq_priv *priv = m->private;
3110 struct ocfs2_lock_res *iter = v;
3111 struct ocfs2_lock_res *dummy = &priv->p_iter_res;
3112
3113 (*pos)++;
3114 spin_lock(&ocfs2_dlm_tracking_lock);
3115 iter = ocfs2_dlm_next_res(iter, priv);
3116 list_del_init(&dummy->l_debug_list);
3117 if (iter) {
3118 list_add(&dummy->l_debug_list, &iter->l_debug_list);
3119 priv->p_tmp_res = *iter;
3120 iter = &priv->p_tmp_res;
3121 }
3122 spin_unlock(&ocfs2_dlm_tracking_lock);
3123
3124 return iter;
3125}
3126
3127/*
3128 * Version is used by debugfs.ocfs2 to determine the format being used
3129 *
3130 * New in version 2
3131 * - Lock stats printed
3132 * New in version 3
3133 * - Max time in lock stats is in usecs (instead of nsecs)
3134 * New in version 4
3135 * - Add last pr/ex unlock times and first lock wait time in usecs
3136 */
3137#define OCFS2_DLM_DEBUG_STR_VERSION 4
3138static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
3139{
3140 int i;
3141 char *lvb;
3142 struct ocfs2_lock_res *lockres = v;
3143#ifdef CONFIG_OCFS2_FS_STATS
3144 u64 now, last;
3145 struct ocfs2_dlm_debug *dlm_debug =
3146 ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug;
3147#endif
3148
3149 if (!lockres)
3150 return -EINVAL;
3151
3152#ifdef CONFIG_OCFS2_FS_STATS
3153 if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) {
3154 now = ktime_to_us(ktime_get_real());
3155 last = max(lockres->l_lock_prmode.ls_last,
3156 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}