2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/buffer_head.h>
14 #include <linux/delay.h>
15 #include <linux/sort.h>
16 #include <linux/jhash.h>
17 #include <linux/kallsyms.h>
18 #include <linux/gfs2_ondisk.h>
19 #include <linux/list.h>
20 #include <linux/wait.h>
21 #include <linux/module.h>
22 #include <asm/uaccess.h>
23 #include <linux/seq_file.h>
24 #include <linux/debugfs.h>
25 #include <linux/kthread.h>
26 #include <linux/freezer.h>
27 #include <linux/workqueue.h>
28 #include <linux/jiffies.h>
29 #include <linux/rcupdate.h>
30 #include <linux/rculist_bl.h>
31 #include <linux/bit_spinlock.h>
44 #define CREATE_TRACE_POINTS
45 #include "trace_gfs2.h"
47 struct gfs2_glock_iter {
48 int hash; /* hash bucket index */
49 struct gfs2_sbd *sdp; /* incore superblock */
50 struct gfs2_glock *gl; /* current glock struct */
51 char string[512]; /* scratch space */
54 typedef void (*glock_examiner) (struct gfs2_glock * gl);
56 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
57 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
58 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
60 static struct dentry *gfs2_root;
61 static struct workqueue_struct *glock_workqueue;
62 struct workqueue_struct *gfs2_delete_workqueue;
63 static LIST_HEAD(lru_list);
64 static atomic_t lru_count = ATOMIC_INIT(0);
65 static DEFINE_SPINLOCK(lru_lock);
67 #define GFS2_GL_HASH_SHIFT 15
68 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
69 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
71 static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE];
72 static struct dentry *gfs2_root;
75 * gl_hash() - Turn glock number into hash bucket number
76 * @lock: The glock number
78 * Returns: The number of the corresponding hash bucket
81 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
82 const struct lm_lockname *name)
86 h = jhash(&name->ln_number, sizeof(u64), 0);
87 h = jhash(&name->ln_type, sizeof(unsigned int), h);
88 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
89 h &= GFS2_GL_HASH_MASK;
94 static inline void spin_lock_bucket(unsigned int hash)
96 hlist_bl_lock(&gl_hash_table[hash]);
99 static inline void spin_unlock_bucket(unsigned int hash)
101 hlist_bl_unlock(&gl_hash_table[hash]);
104 static void gfs2_glock_dealloc(struct rcu_head *rcu)
106 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
108 if (gl->gl_ops->go_flags & GLOF_ASPACE)
109 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
111 kmem_cache_free(gfs2_glock_cachep, gl);
114 void gfs2_glock_free(struct gfs2_glock *gl)
116 struct gfs2_sbd *sdp = gl->gl_sbd;
118 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
119 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
120 wake_up(&sdp->sd_glock_wait);
124 * gfs2_glock_hold() - increment reference count on glock
125 * @gl: The glock to hold
129 void gfs2_glock_hold(struct gfs2_glock *gl)
131 GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0);
132 atomic_inc(&gl->gl_ref);
136 * demote_ok - Check to see if it's ok to unlock a glock
139 * Returns: 1 if it's ok
142 static int demote_ok(const struct gfs2_glock *gl)
144 const struct gfs2_glock_operations *glops = gl->gl_ops;
146 if (gl->gl_state == LM_ST_UNLOCKED)
148 if (!list_empty(&gl->gl_holders))
150 if (glops->go_demote_ok)
151 return glops->go_demote_ok(gl);
156 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
158 spin_lock(&lru_lock);
160 if (!list_empty(&gl->gl_lru))
161 list_del_init(&gl->gl_lru);
163 atomic_inc(&lru_count);
165 list_add_tail(&gl->gl_lru, &lru_list);
166 set_bit(GLF_LRU, &gl->gl_flags);
167 spin_unlock(&lru_lock);
170 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
172 spin_lock(&lru_lock);
173 if (!list_empty(&gl->gl_lru)) {
174 list_del_init(&gl->gl_lru);
175 atomic_dec(&lru_count);
176 clear_bit(GLF_LRU, &gl->gl_flags);
178 spin_unlock(&lru_lock);
182 * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
185 * If the glock is demotable, then we add it (or move it) to the end
186 * of the glock LRU list.
189 static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
192 gfs2_glock_add_to_lru(gl);
196 * gfs2_glock_put_nolock() - Decrement reference count on glock
197 * @gl: The glock to put
199 * This function should only be used if the caller has its own reference
200 * to the glock, in addition to the one it is dropping.
203 void gfs2_glock_put_nolock(struct gfs2_glock *gl)
205 if (atomic_dec_and_test(&gl->gl_ref))
210 * gfs2_glock_put() - Decrement reference count on glock
211 * @gl: The glock to put
215 void gfs2_glock_put(struct gfs2_glock *gl)
217 struct gfs2_sbd *sdp = gl->gl_sbd;
218 struct address_space *mapping = gfs2_glock2aspace(gl);
220 if (atomic_dec_and_test(&gl->gl_ref)) {
221 spin_lock_bucket(gl->gl_hash);
222 hlist_bl_del_rcu(&gl->gl_list);
223 spin_unlock_bucket(gl->gl_hash);
224 gfs2_glock_remove_from_lru(gl);
225 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
226 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
227 trace_gfs2_glock_put(gl);
228 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
233 * search_bucket() - Find struct gfs2_glock by lock number
234 * @bucket: the bucket to search
235 * @name: The lock name
237 * Returns: NULL, or the struct gfs2_glock with the requested number
240 static struct gfs2_glock *search_bucket(unsigned int hash,
241 const struct gfs2_sbd *sdp,
242 const struct lm_lockname *name)
244 struct gfs2_glock *gl;
245 struct hlist_bl_node *h;
247 hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
248 if (!lm_name_equal(&gl->gl_name, name))
250 if (gl->gl_sbd != sdp)
252 if (atomic_inc_not_zero(&gl->gl_ref))
260 * may_grant - check if its ok to grant a new lock
262 * @gh: The lock request which we wish to grant
264 * Returns: true if its ok to grant the lock
267 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
269 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
270 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
271 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
273 if (gl->gl_state == gh->gh_state)
275 if (gh->gh_flags & GL_EXACT)
277 if (gl->gl_state == LM_ST_EXCLUSIVE) {
278 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
280 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
283 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
288 static void gfs2_holder_wake(struct gfs2_holder *gh)
290 clear_bit(HIF_WAIT, &gh->gh_iflags);
291 smp_mb__after_clear_bit();
292 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
296 * do_error - Something unexpected has happened during a lock request
300 static inline void do_error(struct gfs2_glock *gl, const int ret)
302 struct gfs2_holder *gh, *tmp;
304 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
305 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
307 if (ret & LM_OUT_ERROR)
309 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
310 gh->gh_error = GLR_TRYFAILED;
313 list_del_init(&gh->gh_list);
314 trace_gfs2_glock_queue(gh, 0);
315 gfs2_holder_wake(gh);
320 * do_promote - promote as many requests as possible on the current queue
323 * Returns: 1 if there is a blocked holder at the head of the list, or 2
324 * if a type specific operation is underway.
327 static int do_promote(struct gfs2_glock *gl)
328 __releases(&gl->gl_spin)
329 __acquires(&gl->gl_spin)
331 const struct gfs2_glock_operations *glops = gl->gl_ops;
332 struct gfs2_holder *gh, *tmp;
336 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
337 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
339 if (may_grant(gl, gh)) {
340 if (gh->gh_list.prev == &gl->gl_holders &&
342 spin_unlock(&gl->gl_spin);
343 /* FIXME: eliminate this eventually */
344 ret = glops->go_lock(gh);
345 spin_lock(&gl->gl_spin);
350 list_del_init(&gh->gh_list);
351 trace_gfs2_glock_queue(gh, 0);
352 gfs2_holder_wake(gh);
355 set_bit(HIF_HOLDER, &gh->gh_iflags);
356 trace_gfs2_promote(gh, 1);
357 gfs2_holder_wake(gh);
360 set_bit(HIF_HOLDER, &gh->gh_iflags);
361 trace_gfs2_promote(gh, 0);
362 gfs2_holder_wake(gh);
365 if (gh->gh_list.prev == &gl->gl_holders)
374 * find_first_waiter - find the first gh that's waiting for the glock
378 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
380 struct gfs2_holder *gh;
382 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
383 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
390 * state_change - record that the glock is now in a different state
392 * @new_state the new state
396 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
400 held1 = (gl->gl_state != LM_ST_UNLOCKED);
401 held2 = (new_state != LM_ST_UNLOCKED);
403 if (held1 != held2) {
407 gfs2_glock_put_nolock(gl);
409 if (held1 && held2 && list_empty(&gl->gl_holders))
410 clear_bit(GLF_QUEUED, &gl->gl_flags);
412 if (new_state != gl->gl_target)
413 /* shorten our minimum hold time */
414 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
416 gl->gl_state = new_state;
417 gl->gl_tchange = jiffies;
420 static void gfs2_demote_wake(struct gfs2_glock *gl)
422 gl->gl_demote_state = LM_ST_EXCLUSIVE;
423 clear_bit(GLF_DEMOTE, &gl->gl_flags);
424 smp_mb__after_clear_bit();
425 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
429 * finish_xmote - The DLM has replied to one of our lock requests
431 * @ret: The status from the DLM
435 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
437 const struct gfs2_glock_operations *glops = gl->gl_ops;
438 struct gfs2_holder *gh;
439 unsigned state = ret & LM_OUT_ST_MASK;
442 spin_lock(&gl->gl_spin);
443 trace_gfs2_glock_state_change(gl, state);
444 state_change(gl, state);
445 gh = find_first_waiter(gl);
447 /* Demote to UN request arrived during demote to SH or DF */
448 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
449 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
450 gl->gl_target = LM_ST_UNLOCKED;
452 /* Check for state != intended state */
453 if (unlikely(state != gl->gl_target)) {
454 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
455 /* move to back of queue and try next entry */
456 if (ret & LM_OUT_CANCELED) {
457 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
458 list_move_tail(&gh->gh_list, &gl->gl_holders);
459 gh = find_first_waiter(gl);
460 gl->gl_target = gh->gh_state;
463 /* Some error or failed "try lock" - report it */
464 if ((ret & LM_OUT_ERROR) ||
465 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
466 gl->gl_target = gl->gl_state;
472 /* Unlocked due to conversion deadlock, try again */
475 do_xmote(gl, gh, gl->gl_target);
477 /* Conversion fails, unlock and try again */
480 do_xmote(gl, gh, LM_ST_UNLOCKED);
482 default: /* Everything else */
483 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
486 spin_unlock(&gl->gl_spin);
490 /* Fast path - we got what we asked for */
491 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
492 gfs2_demote_wake(gl);
493 if (state != LM_ST_UNLOCKED) {
494 if (glops->go_xmote_bh) {
495 spin_unlock(&gl->gl_spin);
496 rv = glops->go_xmote_bh(gl, gh);
497 spin_lock(&gl->gl_spin);
508 clear_bit(GLF_LOCK, &gl->gl_flags);
510 spin_unlock(&gl->gl_spin);
514 * do_xmote - Calls the DLM to change the state of a lock
515 * @gl: The lock state
516 * @gh: The holder (only for promotes)
517 * @target: The target lock state
521 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
522 __releases(&gl->gl_spin)
523 __acquires(&gl->gl_spin)
525 const struct gfs2_glock_operations *glops = gl->gl_ops;
526 struct gfs2_sbd *sdp = gl->gl_sbd;
527 unsigned int lck_flags = gh ? gh->gh_flags : 0;
530 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
532 GLOCK_BUG_ON(gl, gl->gl_state == target);
533 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
534 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
536 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
537 do_error(gl, 0); /* Fail queued try locks */
540 spin_unlock(&gl->gl_spin);
541 if (glops->go_xmote_th)
542 glops->go_xmote_th(gl);
543 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
544 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
545 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
548 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
550 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
551 GLOCK_BUG_ON(gl, ret);
552 } else { /* lock_nolock */
553 finish_xmote(gl, target);
554 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
558 spin_lock(&gl->gl_spin);
562 * find_first_holder - find the first "holder" gh
566 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
568 struct gfs2_holder *gh;
570 if (!list_empty(&gl->gl_holders)) {
571 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
572 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
579 * run_queue - do all outstanding tasks related to a glock
580 * @gl: The glock in question
581 * @nonblock: True if we must not block in run_queue
585 static void run_queue(struct gfs2_glock *gl, const int nonblock)
586 __releases(&gl->gl_spin)
587 __acquires(&gl->gl_spin)
589 struct gfs2_holder *gh = NULL;
592 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
595 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
597 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
598 gl->gl_demote_state != gl->gl_state) {
599 if (find_first_holder(gl))
603 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
604 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
605 gl->gl_target = gl->gl_demote_state;
607 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
608 gfs2_demote_wake(gl);
609 ret = do_promote(gl);
614 gh = find_first_waiter(gl);
615 gl->gl_target = gh->gh_state;
616 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
617 do_error(gl, 0); /* Fail queued try locks */
619 do_xmote(gl, gh, gl->gl_target);
624 clear_bit(GLF_LOCK, &gl->gl_flags);
625 smp_mb__after_clear_bit();
627 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
628 gfs2_glock_put_nolock(gl);
632 clear_bit(GLF_LOCK, &gl->gl_flags);
633 smp_mb__after_clear_bit();
637 static void delete_work_func(struct work_struct *work)
639 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
640 struct gfs2_sbd *sdp = gl->gl_sbd;
641 struct gfs2_inode *ip;
643 u64 no_addr = gl->gl_name.ln_number;
646 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
649 inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
651 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
652 if (inode && !IS_ERR(inode)) {
653 d_prune_aliases(inode);
659 static void glock_work_func(struct work_struct *work)
661 unsigned long delay = 0;
662 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
665 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
666 finish_xmote(gl, gl->gl_reply);
669 spin_lock(&gl->gl_spin);
670 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
671 gl->gl_state != LM_ST_UNLOCKED &&
672 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
673 unsigned long holdtime, now = jiffies;
675 holdtime = gl->gl_tchange + gl->gl_hold_time;
676 if (time_before(now, holdtime))
677 delay = holdtime - now;
680 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
681 set_bit(GLF_DEMOTE, &gl->gl_flags);
685 spin_unlock(&gl->gl_spin);
689 if (gl->gl_name.ln_type != LM_TYPE_INODE)
691 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
699 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
700 * @sdp: The GFS2 superblock
701 * @number: the lock number
702 * @glops: The glock_operations to use
703 * @create: If 0, don't create the glock if it doesn't exist
704 * @glp: the glock is returned here
706 * This does not lock a glock, just finds/creates structures for one.
711 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
712 const struct gfs2_glock_operations *glops, int create,
713 struct gfs2_glock **glp)
715 struct super_block *s = sdp->sd_vfs;
716 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
717 struct gfs2_glock *gl, *tmp;
718 unsigned int hash = gl_hash(sdp, &name);
719 struct address_space *mapping;
720 struct kmem_cache *cachep;
723 gl = search_bucket(hash, sdp, &name);
732 if (glops->go_flags & GLOF_ASPACE)
733 cachep = gfs2_glock_aspace_cachep;
735 cachep = gfs2_glock_cachep;
736 gl = kmem_cache_alloc(cachep, GFP_KERNEL);
740 atomic_inc(&sdp->sd_glock_disposal);
743 atomic_set(&gl->gl_ref, 1);
744 gl->gl_state = LM_ST_UNLOCKED;
745 gl->gl_target = LM_ST_UNLOCKED;
746 gl->gl_demote_state = LM_ST_EXCLUSIVE;
749 snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number);
750 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
751 gl->gl_lksb.sb_lvbptr = gl->gl_lvb;
752 gl->gl_tchange = jiffies;
753 gl->gl_object = NULL;
755 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
756 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
757 INIT_WORK(&gl->gl_delete, delete_work_func);
759 mapping = gfs2_glock2aspace(gl);
761 mapping->a_ops = &gfs2_meta_aops;
762 mapping->host = s->s_bdev->bd_inode;
764 mapping_set_gfp_mask(mapping, GFP_NOFS);
765 mapping->assoc_mapping = NULL;
766 mapping->backing_dev_info = s->s_bdi;
767 mapping->writeback_index = 0;
770 spin_lock_bucket(hash);
771 tmp = search_bucket(hash, sdp, &name);
773 spin_unlock_bucket(hash);
774 kmem_cache_free(cachep, gl);
775 atomic_dec(&sdp->sd_glock_disposal);
778 hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]);
779 spin_unlock_bucket(hash);
788 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
790 * @state: the state we're requesting
791 * @flags: the modifier flags
792 * @gh: the holder structure
796 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
797 struct gfs2_holder *gh)
799 INIT_LIST_HEAD(&gh->gh_list);
801 gh->gh_ip = (unsigned long)__builtin_return_address(0);
802 gh->gh_owner_pid = get_pid(task_pid(current));
803 gh->gh_state = state;
804 gh->gh_flags = flags;
811 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
812 * @state: the state we're requesting
813 * @flags: the modifier flags
814 * @gh: the holder structure
816 * Don't mess with the glock.
820 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
822 gh->gh_state = state;
823 gh->gh_flags = flags;
825 gh->gh_ip = (unsigned long)__builtin_return_address(0);
826 if (gh->gh_owner_pid)
827 put_pid(gh->gh_owner_pid);
828 gh->gh_owner_pid = get_pid(task_pid(current));
832 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
833 * @gh: the holder structure
837 void gfs2_holder_uninit(struct gfs2_holder *gh)
839 put_pid(gh->gh_owner_pid);
840 gfs2_glock_put(gh->gh_gl);
846 * gfs2_glock_holder_wait
849 * This function and gfs2_glock_demote_wait both show up in the WCHAN
850 * field. Thus I've separated these otherwise identical functions in
851 * order to be more informative to the user.
854 static int gfs2_glock_holder_wait(void *word)
860 static int gfs2_glock_demote_wait(void *word)
866 static void wait_on_holder(struct gfs2_holder *gh)
868 unsigned long time1 = jiffies;
871 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
872 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
873 /* Lengthen the minimum hold time. */
874 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
879 static void wait_on_demote(struct gfs2_glock *gl)
882 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
886 * handle_callback - process a demote request
888 * @state: the state the caller wants us to change to
890 * There are only two requests that we are going to see in actual
891 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
894 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
897 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
899 set_bit(bit, &gl->gl_flags);
900 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
901 gl->gl_demote_state = state;
902 gl->gl_demote_time = jiffies;
903 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
904 gl->gl_demote_state != state) {
905 gl->gl_demote_state = LM_ST_UNLOCKED;
907 if (gl->gl_ops->go_callback)
908 gl->gl_ops->go_callback(gl);
909 trace_gfs2_demote_rq(gl);
913 * gfs2_glock_wait - wait on a glock acquisition
914 * @gh: the glock holder
916 * Returns: 0 on success
919 int gfs2_glock_wait(struct gfs2_holder *gh)
925 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
927 struct va_format vaf;
933 struct gfs2_glock_iter *gi = seq->private;
934 vsprintf(gi->string, fmt, args);
935 seq_printf(seq, gi->string);
940 printk(KERN_ERR " %pV", &vaf);
947 * add_to_queue - Add a holder to the wait queue (but look for recursion)
948 * @gh: the holder structure to add
950 * Eventually we should move the recursive locking trap to a
951 * debugging option or something like that. This is the fast
952 * path and needs to have the minimum number of distractions.
956 static inline void add_to_queue(struct gfs2_holder *gh)
957 __releases(&gl->gl_spin)
958 __acquires(&gl->gl_spin)
960 struct gfs2_glock *gl = gh->gh_gl;
961 struct gfs2_sbd *sdp = gl->gl_sbd;
962 struct list_head *insert_pt = NULL;
963 struct gfs2_holder *gh2;
966 BUG_ON(gh->gh_owner_pid == NULL);
967 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
970 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
971 if (test_bit(GLF_LOCK, &gl->gl_flags))
973 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
977 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
978 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
979 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
982 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
983 !may_grant(gl, gh)) {
985 gh->gh_error = GLR_TRYFAILED;
986 gfs2_holder_wake(gh);
989 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
991 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
992 insert_pt = &gh2->gh_list;
994 set_bit(GLF_QUEUED, &gl->gl_flags);
995 trace_gfs2_glock_queue(gh, 1);
996 if (likely(insert_pt == NULL)) {
997 list_add_tail(&gh->gh_list, &gl->gl_holders);
998 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1002 list_add_tail(&gh->gh_list, insert_pt);
1004 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1005 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1006 spin_unlock(&gl->gl_spin);
1007 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1008 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1009 spin_lock(&gl->gl_spin);
1014 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
1015 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1016 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1017 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1018 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
1019 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
1020 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1021 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1022 __dump_glock(NULL, gl);
1027 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1028 * @gh: the holder structure
1030 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1032 * Returns: 0, GLR_TRYFAILED, or errno on failure
1035 int gfs2_glock_nq(struct gfs2_holder *gh)
1037 struct gfs2_glock *gl = gh->gh_gl;
1038 struct gfs2_sbd *sdp = gl->gl_sbd;
1041 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1044 if (test_bit(GLF_LRU, &gl->gl_flags))
1045 gfs2_glock_remove_from_lru(gl);
1047 spin_lock(&gl->gl_spin);
1049 if ((LM_FLAG_NOEXP & gh->gh_flags) &&
1050 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1051 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1053 spin_unlock(&gl->gl_spin);
1055 if (!(gh->gh_flags & GL_ASYNC))
1056 error = gfs2_glock_wait(gh);
1062 * gfs2_glock_poll - poll to see if an async request has been completed
1065 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1068 int gfs2_glock_poll(struct gfs2_holder *gh)
1070 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1074 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1075 * @gh: the glock holder
1079 void gfs2_glock_dq(struct gfs2_holder *gh)
1081 struct gfs2_glock *gl = gh->gh_gl;
1082 const struct gfs2_glock_operations *glops = gl->gl_ops;
1086 spin_lock(&gl->gl_spin);
1087 if (gh->gh_flags & GL_NOCACHE)
1088 handle_callback(gl, LM_ST_UNLOCKED, 0);
1090 list_del_init(&gh->gh_list);
1091 if (find_first_holder(gl) == NULL) {
1092 if (glops->go_unlock) {
1093 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1094 spin_unlock(&gl->gl_spin);
1095 glops->go_unlock(gh);
1096 spin_lock(&gl->gl_spin);
1097 clear_bit(GLF_LOCK, &gl->gl_flags);
1099 if (list_empty(&gl->gl_holders) &&
1100 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1101 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1104 if (!test_bit(GLF_LFLUSH, &gl->gl_flags))
1105 __gfs2_glock_schedule_for_reclaim(gl);
1106 trace_gfs2_glock_queue(gh, 0);
1107 spin_unlock(&gl->gl_spin);
1108 if (likely(fast_path))
1111 gfs2_glock_hold(gl);
1112 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1113 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1114 gl->gl_name.ln_type == LM_TYPE_INODE)
1115 delay = gl->gl_hold_time;
1116 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1120 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1122 struct gfs2_glock *gl = gh->gh_gl;
1128 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1129 * @gh: the holder structure
1133 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1136 gfs2_holder_uninit(gh);
1140 * gfs2_glock_nq_num - acquire a glock based on lock number
1141 * @sdp: the filesystem
1142 * @number: the lock number
1143 * @glops: the glock operations for the type of glock
1144 * @state: the state to acquire the glock in
1145 * @flags: modifier flags for the acquisition
1146 * @gh: the struct gfs2_holder
1151 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1152 const struct gfs2_glock_operations *glops,
1153 unsigned int state, int flags, struct gfs2_holder *gh)
1155 struct gfs2_glock *gl;
1158 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1160 error = gfs2_glock_nq_init(gl, state, flags, gh);
1168 * glock_compare - Compare two struct gfs2_glock structures for sorting
1169 * @arg_a: the first structure
1170 * @arg_b: the second structure
1174 static int glock_compare(const void *arg_a, const void *arg_b)
1176 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1177 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1178 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1179 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1181 if (a->ln_number > b->ln_number)
1183 if (a->ln_number < b->ln_number)
1185 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1190 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1191 * @num_gh: the number of structures
1192 * @ghs: an array of struct gfs2_holder structures
1194 * Returns: 0 on success (all glocks acquired),
1195 * errno on failure (no glocks acquired)
1198 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1199 struct gfs2_holder **p)
1204 for (x = 0; x < num_gh; x++)
1207 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1209 for (x = 0; x < num_gh; x++) {
1210 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1212 error = gfs2_glock_nq(p[x]);
1215 gfs2_glock_dq(p[x]);
1224 * gfs2_glock_nq_m - acquire multiple glocks
1225 * @num_gh: the number of structures
1226 * @ghs: an array of struct gfs2_holder structures
1229 * Returns: 0 on success (all glocks acquired),
1230 * errno on failure (no glocks acquired)
1233 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1235 struct gfs2_holder *tmp[4];
1236 struct gfs2_holder **pph = tmp;
1243 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1244 return gfs2_glock_nq(ghs);
1248 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1253 error = nq_m_sync(num_gh, ghs, pph);
1262 * gfs2_glock_dq_m - release multiple glocks
1263 * @num_gh: the number of structures
1264 * @ghs: an array of struct gfs2_holder structures
1268 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1271 gfs2_glock_dq(&ghs[num_gh]);
1275 * gfs2_glock_dq_uninit_m - release multiple glocks
1276 * @num_gh: the number of structures
1277 * @ghs: an array of struct gfs2_holder structures
1281 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1284 gfs2_glock_dq_uninit(&ghs[num_gh]);
1287 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1289 unsigned long delay = 0;
1290 unsigned long holdtime;
1291 unsigned long now = jiffies;
1293 gfs2_glock_hold(gl);
1294 holdtime = gl->gl_tchange + gl->gl_hold_time;
1295 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1296 gl->gl_name.ln_type == LM_TYPE_INODE) {
1297 if (time_before(now, holdtime))
1298 delay = holdtime - now;
1299 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1300 delay = gl->gl_hold_time;
1303 spin_lock(&gl->gl_spin);
1304 handle_callback(gl, state, delay);
1305 spin_unlock(&gl->gl_spin);
1306 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1311 * gfs2_should_freeze - Figure out if glock should be frozen
1312 * @gl: The glock in question
1314 * Glocks are not frozen if (a) the result of the dlm operation is
1315 * an error, (b) the locking operation was an unlock operation or
1316 * (c) if there is a "noexp" flagged request anywhere in the queue
1318 * Returns: 1 if freezing should occur, 0 otherwise
1321 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1323 const struct gfs2_holder *gh;
1325 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1327 if (gl->gl_target == LM_ST_UNLOCKED)
1330 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1331 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1333 if (LM_FLAG_NOEXP & gh->gh_flags)
1341 * gfs2_glock_complete - Callback used by locking
1342 * @gl: Pointer to the glock
1343 * @ret: The return value from the dlm
1345 * The gl_reply field is under the gl_spin lock so that it is ok
1346 * to use a bitfield shared with other glock state fields.
1349 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1351 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1353 spin_lock(&gl->gl_spin);
1356 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) {
1357 if (gfs2_should_freeze(gl)) {
1358 set_bit(GLF_FROZEN, &gl->gl_flags);
1359 spin_unlock(&gl->gl_spin);
1364 spin_unlock(&gl->gl_spin);
1365 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1367 gfs2_glock_hold(gl);
1368 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1373 static int gfs2_shrink_glock_memory(struct shrinker *shrink,
1374 struct shrink_control *sc)
1376 struct gfs2_glock *gl;
1379 int nr = sc->nr_to_scan;
1380 gfp_t gfp_mask = sc->gfp_mask;
1386 if (!(gfp_mask & __GFP_FS))
1389 spin_lock(&lru_lock);
1390 while(nr && !list_empty(&lru_list)) {
1391 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1392 list_del_init(&gl->gl_lru);
1393 clear_bit(GLF_LRU, &gl->gl_flags);
1394 atomic_dec(&lru_count);
1396 /* Test for being demotable */
1397 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1398 gfs2_glock_hold(gl);
1399 spin_unlock(&lru_lock);
1400 spin_lock(&gl->gl_spin);
1401 may_demote = demote_ok(gl);
1403 handle_callback(gl, LM_ST_UNLOCKED, 0);
1406 clear_bit(GLF_LOCK, &gl->gl_flags);
1407 smp_mb__after_clear_bit();
1408 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1409 gfs2_glock_put_nolock(gl);
1410 spin_unlock(&gl->gl_spin);
1411 spin_lock(&lru_lock);
1415 list_add(&gl->gl_lru, &skipped);
1416 set_bit(GLF_LRU, &gl->gl_flags);
1418 list_splice(&skipped, &lru_list);
1419 atomic_add(nr_skipped, &lru_count);
1420 spin_unlock(&lru_lock);
1422 return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
1425 static struct shrinker glock_shrinker = {
1426 .shrink = gfs2_shrink_glock_memory,
1427 .seeks = DEFAULT_SEEKS,
1431 * examine_bucket - Call a function for glock in a hash bucket
1432 * @examiner: the function
1433 * @sdp: the filesystem
1434 * @bucket: the bucket
1438 static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
1441 struct gfs2_glock *gl;
1442 struct hlist_bl_head *head = &gl_hash_table[hash];
1443 struct hlist_bl_node *pos;
1446 hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
1447 if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref))
1454 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1458 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1459 examine_bucket(examiner, sdp, x);
1464 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1465 * @gl: The glock to thaw
1467 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1468 * so this has to result in the ref count being dropped by one.
1471 static void thaw_glock(struct gfs2_glock *gl)
1473 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1475 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1476 gfs2_glock_hold(gl);
1477 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1482 * clear_glock - look at a glock and see if we can free it from glock cache
1483 * @gl: the glock to look at
1487 static void clear_glock(struct gfs2_glock *gl)
1489 gfs2_glock_remove_from_lru(gl);
1491 spin_lock(&gl->gl_spin);
1492 if (gl->gl_state != LM_ST_UNLOCKED)
1493 handle_callback(gl, LM_ST_UNLOCKED, 0);
1494 spin_unlock(&gl->gl_spin);
1495 gfs2_glock_hold(gl);
1496 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1501 * gfs2_glock_thaw - Thaw any frozen glocks
1502 * @sdp: The super block
1506 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1508 glock_hash_walk(thaw_glock, sdp);
1511 static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1514 spin_lock(&gl->gl_spin);
1515 ret = __dump_glock(seq, gl);
1516 spin_unlock(&gl->gl_spin);
1520 static void dump_glock_func(struct gfs2_glock *gl)
1522 dump_glock(NULL, gl);
1526 * gfs2_gl_hash_clear - Empty out the glock hash table
1527 * @sdp: the filesystem
1528 * @wait: wait until it's all gone
1530 * Called when unmounting the filesystem.
1533 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1535 glock_hash_walk(clear_glock, sdp);
1536 flush_workqueue(glock_workqueue);
1537 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1538 glock_hash_walk(dump_glock_func, sdp);
1541 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1543 struct gfs2_glock *gl = ip->i_gl;
1546 ret = gfs2_truncatei_resume(ip);
1547 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1549 spin_lock(&gl->gl_spin);
1550 clear_bit(GLF_LOCK, &gl->gl_flags);
1552 spin_unlock(&gl->gl_spin);
1555 static const char *state2str(unsigned state)
1558 case LM_ST_UNLOCKED:
1562 case LM_ST_DEFERRED:
1564 case LM_ST_EXCLUSIVE:
1570 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1573 if (flags & LM_FLAG_TRY)
1575 if (flags & LM_FLAG_TRY_1CB)
1577 if (flags & LM_FLAG_NOEXP)
1579 if (flags & LM_FLAG_ANY)
1581 if (flags & LM_FLAG_PRIORITY)
1583 if (flags & GL_ASYNC)
1585 if (flags & GL_EXACT)
1587 if (flags & GL_NOCACHE)
1589 if (test_bit(HIF_HOLDER, &iflags))
1591 if (test_bit(HIF_WAIT, &iflags))
1593 if (test_bit(HIF_FIRST, &iflags))
1600 * dump_holder - print information about a glock holder
1601 * @seq: the seq_file struct
1602 * @gh: the glock holder
1604 * Returns: 0 on success, -ENOBUFS when we run out of space
1607 static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1609 struct task_struct *gh_owner = NULL;
1612 if (gh->gh_owner_pid)
1613 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1614 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1615 state2str(gh->gh_state),
1616 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1618 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1619 gh_owner ? gh_owner->comm : "(ended)",
1624 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1626 const unsigned long *gflags = &gl->gl_flags;
1629 if (test_bit(GLF_LOCK, gflags))
1631 if (test_bit(GLF_DEMOTE, gflags))
1633 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1635 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1637 if (test_bit(GLF_DIRTY, gflags))
1639 if (test_bit(GLF_LFLUSH, gflags))
1641 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1643 if (test_bit(GLF_REPLY_PENDING, gflags))
1645 if (test_bit(GLF_INITIAL, gflags))
1647 if (test_bit(GLF_FROZEN, gflags))
1649 if (test_bit(GLF_QUEUED, gflags))
1651 if (test_bit(GLF_LRU, gflags))
1660 * __dump_glock - print information about a glock
1661 * @seq: The seq_file struct
1664 * The file format is as follows:
1665 * One line per object, capital letters are used to indicate objects
1666 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1667 * other objects are indented by a single space and follow the glock to
1668 * which they are related. Fields are indicated by lower case letters
1669 * followed by a colon and the field value, except for strings which are in
1670 * [] so that its possible to see if they are composed of spaces for
1671 * example. The field's are n = number (id of the object), f = flags,
1672 * t = type, s = state, r = refcount, e = error, p = pid.
1674 * Returns: 0 on success, -ENOBUFS when we run out of space
1677 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1679 const struct gfs2_glock_operations *glops = gl->gl_ops;
1680 unsigned long long dtime;
1681 const struct gfs2_holder *gh;
1682 char gflags_buf[32];
1685 dtime = jiffies - gl->gl_demote_time;
1686 dtime *= 1000000/HZ; /* demote time in uSec */
1687 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1689 gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d m:%ld\n",
1690 state2str(gl->gl_state),
1691 gl->gl_name.ln_type,
1692 (unsigned long long)gl->gl_name.ln_number,
1693 gflags2str(gflags_buf, gl),
1694 state2str(gl->gl_target),
1695 state2str(gl->gl_demote_state), dtime,
1696 atomic_read(&gl->gl_ail_count),
1697 atomic_read(&gl->gl_revokes),
1698 atomic_read(&gl->gl_ref), gl->gl_hold_time);
1700 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1701 error = dump_holder(seq, gh);
1705 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1706 error = glops->go_dump(seq, gl);
1714 int __init gfs2_glock_init(void)
1717 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1718 INIT_HLIST_BL_HEAD(&gl_hash_table[i]);
1721 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1722 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1723 if (IS_ERR(glock_workqueue))
1724 return PTR_ERR(glock_workqueue);
1725 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1726 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1728 if (IS_ERR(gfs2_delete_workqueue)) {
1729 destroy_workqueue(glock_workqueue);
1730 return PTR_ERR(gfs2_delete_workqueue);
1733 register_shrinker(&glock_shrinker);
1738 void gfs2_glock_exit(void)
1740 unregister_shrinker(&glock_shrinker);
1741 destroy_workqueue(glock_workqueue);
1742 destroy_workqueue(gfs2_delete_workqueue);
1745 static inline struct gfs2_glock *glock_hash_chain(unsigned hash)
1747 return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]),
1748 struct gfs2_glock, gl_list);
1751 static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl)
1753 return hlist_bl_entry(rcu_dereference(gl->gl_list.next),
1754 struct gfs2_glock, gl_list);
1757 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1759 struct gfs2_glock *gl;
1764 gi->gl = glock_hash_next(gl);
1766 gi->gl = glock_hash_chain(gi->hash);
1768 while (gi->gl == NULL) {
1770 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1774 gi->gl = glock_hash_chain(gi->hash);
1776 /* Skip entries for other sb and dead entries */
1777 } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0);
1782 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1784 struct gfs2_glock_iter *gi = seq->private;
1791 if (gfs2_glock_iter_next(gi))
1798 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1801 struct gfs2_glock_iter *gi = seq->private;
1805 if (gfs2_glock_iter_next(gi))
1811 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1813 struct gfs2_glock_iter *gi = seq->private;
1820 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1822 return dump_glock(seq, iter_ptr);
1825 static const struct seq_operations gfs2_glock_seq_ops = {
1826 .start = gfs2_glock_seq_start,
1827 .next = gfs2_glock_seq_next,
1828 .stop = gfs2_glock_seq_stop,
1829 .show = gfs2_glock_seq_show,
1832 static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1834 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1835 sizeof(struct gfs2_glock_iter));
1837 struct seq_file *seq = file->private_data;
1838 struct gfs2_glock_iter *gi = seq->private;
1839 gi->sdp = inode->i_private;
1844 static const struct file_operations gfs2_debug_fops = {
1845 .owner = THIS_MODULE,
1846 .open = gfs2_debugfs_open,
1848 .llseek = seq_lseek,
1849 .release = seq_release_private,
1852 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1854 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1855 if (!sdp->debugfs_dir)
1857 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1859 sdp->debugfs_dir, sdp,
1861 if (!sdp->debugfs_dentry_glocks)
1867 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1869 if (sdp && sdp->debugfs_dir) {
1870 if (sdp->debugfs_dentry_glocks) {
1871 debugfs_remove(sdp->debugfs_dentry_glocks);
1872 sdp->debugfs_dentry_glocks = NULL;
1874 debugfs_remove(sdp->debugfs_dir);
1875 sdp->debugfs_dir = NULL;
1879 int gfs2_register_debugfs(void)
1881 gfs2_root = debugfs_create_dir("gfs2", NULL);
1882 return gfs2_root ? 0 : -ENOMEM;
1885 void gfs2_unregister_debugfs(void)
1887 debugfs_remove(gfs2_root);