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>
32 #include <linux/percpu.h>
45 #define CREATE_TRACE_POINTS
46 #include "trace_gfs2.h"
48 struct gfs2_glock_iter {
49 int hash; /* hash bucket index */
50 unsigned nhash; /* Index within current bucket */
51 struct gfs2_sbd *sdp; /* incore superblock */
52 struct gfs2_glock *gl; /* current glock struct */
53 loff_t last_pos; /* last position */
54 char string[512]; /* scratch space */
57 typedef void (*glock_examiner) (struct gfs2_glock * gl);
59 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
60 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
61 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
63 static struct dentry *gfs2_root;
64 static struct workqueue_struct *glock_workqueue;
65 struct workqueue_struct *gfs2_delete_workqueue;
66 static LIST_HEAD(lru_list);
67 static atomic_t lru_count = ATOMIC_INIT(0);
68 static DEFINE_SPINLOCK(lru_lock);
70 #define GFS2_GL_HASH_SHIFT 15
71 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
72 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
74 static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE];
75 static struct dentry *gfs2_root;
78 * gl_hash() - Turn glock number into hash bucket number
79 * @lock: The glock number
81 * Returns: The number of the corresponding hash bucket
84 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
85 const struct lm_lockname *name)
89 h = jhash(&name->ln_number, sizeof(u64), 0);
90 h = jhash(&name->ln_type, sizeof(unsigned int), h);
91 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
92 h &= GFS2_GL_HASH_MASK;
97 static inline void spin_lock_bucket(unsigned int hash)
99 hlist_bl_lock(&gl_hash_table[hash]);
102 static inline void spin_unlock_bucket(unsigned int hash)
104 hlist_bl_unlock(&gl_hash_table[hash]);
107 static void gfs2_glock_dealloc(struct rcu_head *rcu)
109 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
111 if (gl->gl_ops->go_flags & GLOF_ASPACE)
112 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
114 kmem_cache_free(gfs2_glock_cachep, gl);
117 void gfs2_glock_free(struct gfs2_glock *gl)
119 struct gfs2_sbd *sdp = gl->gl_sbd;
121 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
122 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
123 wake_up(&sdp->sd_glock_wait);
127 * gfs2_glock_hold() - increment reference count on glock
128 * @gl: The glock to hold
132 void gfs2_glock_hold(struct gfs2_glock *gl)
134 GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0);
135 atomic_inc(&gl->gl_ref);
139 * demote_ok - Check to see if it's ok to unlock a glock
142 * Returns: 1 if it's ok
145 static int demote_ok(const struct gfs2_glock *gl)
147 const struct gfs2_glock_operations *glops = gl->gl_ops;
149 if (gl->gl_state == LM_ST_UNLOCKED)
151 if (!list_empty(&gl->gl_holders))
153 if (glops->go_demote_ok)
154 return glops->go_demote_ok(gl);
159 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
161 spin_lock(&lru_lock);
163 if (!list_empty(&gl->gl_lru))
164 list_del_init(&gl->gl_lru);
166 atomic_inc(&lru_count);
168 list_add_tail(&gl->gl_lru, &lru_list);
169 set_bit(GLF_LRU, &gl->gl_flags);
170 spin_unlock(&lru_lock);
173 static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
175 if (!list_empty(&gl->gl_lru)) {
176 list_del_init(&gl->gl_lru);
177 atomic_dec(&lru_count);
178 clear_bit(GLF_LRU, &gl->gl_flags);
182 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
184 spin_lock(&lru_lock);
185 __gfs2_glock_remove_from_lru(gl);
186 spin_unlock(&lru_lock);
190 * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
193 * If the glock is demotable, then we add it (or move it) to the end
194 * of the glock LRU list.
197 static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
200 gfs2_glock_add_to_lru(gl);
204 * gfs2_glock_put_nolock() - Decrement reference count on glock
205 * @gl: The glock to put
207 * This function should only be used if the caller has its own reference
208 * to the glock, in addition to the one it is dropping.
211 void gfs2_glock_put_nolock(struct gfs2_glock *gl)
213 if (atomic_dec_and_test(&gl->gl_ref))
218 * gfs2_glock_put() - Decrement reference count on glock
219 * @gl: The glock to put
223 void gfs2_glock_put(struct gfs2_glock *gl)
225 struct gfs2_sbd *sdp = gl->gl_sbd;
226 struct address_space *mapping = gfs2_glock2aspace(gl);
228 if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) {
229 __gfs2_glock_remove_from_lru(gl);
230 spin_unlock(&lru_lock);
231 spin_lock_bucket(gl->gl_hash);
232 hlist_bl_del_rcu(&gl->gl_list);
233 spin_unlock_bucket(gl->gl_hash);
234 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
235 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
236 trace_gfs2_glock_put(gl);
237 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
242 * search_bucket() - Find struct gfs2_glock by lock number
243 * @bucket: the bucket to search
244 * @name: The lock name
246 * Returns: NULL, or the struct gfs2_glock with the requested number
249 static struct gfs2_glock *search_bucket(unsigned int hash,
250 const struct gfs2_sbd *sdp,
251 const struct lm_lockname *name)
253 struct gfs2_glock *gl;
254 struct hlist_bl_node *h;
256 hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
257 if (!lm_name_equal(&gl->gl_name, name))
259 if (gl->gl_sbd != sdp)
261 if (atomic_inc_not_zero(&gl->gl_ref))
269 * may_grant - check if its ok to grant a new lock
271 * @gh: The lock request which we wish to grant
273 * Returns: true if its ok to grant the lock
276 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
278 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
279 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
280 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
282 if (gl->gl_state == gh->gh_state)
284 if (gh->gh_flags & GL_EXACT)
286 if (gl->gl_state == LM_ST_EXCLUSIVE) {
287 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
289 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
292 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
297 static void gfs2_holder_wake(struct gfs2_holder *gh)
299 clear_bit(HIF_WAIT, &gh->gh_iflags);
300 smp_mb__after_clear_bit();
301 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
305 * do_error - Something unexpected has happened during a lock request
309 static inline void do_error(struct gfs2_glock *gl, const int ret)
311 struct gfs2_holder *gh, *tmp;
313 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
314 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
316 if (ret & LM_OUT_ERROR)
318 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
319 gh->gh_error = GLR_TRYFAILED;
322 list_del_init(&gh->gh_list);
323 trace_gfs2_glock_queue(gh, 0);
324 gfs2_holder_wake(gh);
329 * do_promote - promote as many requests as possible on the current queue
332 * Returns: 1 if there is a blocked holder at the head of the list, or 2
333 * if a type specific operation is underway.
336 static int do_promote(struct gfs2_glock *gl)
337 __releases(&gl->gl_spin)
338 __acquires(&gl->gl_spin)
340 const struct gfs2_glock_operations *glops = gl->gl_ops;
341 struct gfs2_holder *gh, *tmp;
345 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
346 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
348 if (may_grant(gl, gh)) {
349 if (gh->gh_list.prev == &gl->gl_holders &&
351 spin_unlock(&gl->gl_spin);
352 /* FIXME: eliminate this eventually */
353 ret = glops->go_lock(gh);
354 spin_lock(&gl->gl_spin);
359 list_del_init(&gh->gh_list);
360 trace_gfs2_glock_queue(gh, 0);
361 gfs2_holder_wake(gh);
364 set_bit(HIF_HOLDER, &gh->gh_iflags);
365 trace_gfs2_promote(gh, 1);
366 gfs2_holder_wake(gh);
369 set_bit(HIF_HOLDER, &gh->gh_iflags);
370 trace_gfs2_promote(gh, 0);
371 gfs2_holder_wake(gh);
374 if (gh->gh_list.prev == &gl->gl_holders)
383 * find_first_waiter - find the first gh that's waiting for the glock
387 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
389 struct gfs2_holder *gh;
391 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
392 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
399 * state_change - record that the glock is now in a different state
401 * @new_state the new state
405 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
409 held1 = (gl->gl_state != LM_ST_UNLOCKED);
410 held2 = (new_state != LM_ST_UNLOCKED);
412 if (held1 != held2) {
416 gfs2_glock_put_nolock(gl);
418 if (held1 && held2 && list_empty(&gl->gl_holders))
419 clear_bit(GLF_QUEUED, &gl->gl_flags);
421 if (new_state != gl->gl_target)
422 /* shorten our minimum hold time */
423 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
425 gl->gl_state = new_state;
426 gl->gl_tchange = jiffies;
429 static void gfs2_demote_wake(struct gfs2_glock *gl)
431 gl->gl_demote_state = LM_ST_EXCLUSIVE;
432 clear_bit(GLF_DEMOTE, &gl->gl_flags);
433 smp_mb__after_clear_bit();
434 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
438 * finish_xmote - The DLM has replied to one of our lock requests
440 * @ret: The status from the DLM
444 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
446 const struct gfs2_glock_operations *glops = gl->gl_ops;
447 struct gfs2_holder *gh;
448 unsigned state = ret & LM_OUT_ST_MASK;
451 spin_lock(&gl->gl_spin);
452 trace_gfs2_glock_state_change(gl, state);
453 state_change(gl, state);
454 gh = find_first_waiter(gl);
456 /* Demote to UN request arrived during demote to SH or DF */
457 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
458 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
459 gl->gl_target = LM_ST_UNLOCKED;
461 /* Check for state != intended state */
462 if (unlikely(state != gl->gl_target)) {
463 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
464 /* move to back of queue and try next entry */
465 if (ret & LM_OUT_CANCELED) {
466 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
467 list_move_tail(&gh->gh_list, &gl->gl_holders);
468 gh = find_first_waiter(gl);
469 gl->gl_target = gh->gh_state;
472 /* Some error or failed "try lock" - report it */
473 if ((ret & LM_OUT_ERROR) ||
474 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
475 gl->gl_target = gl->gl_state;
481 /* Unlocked due to conversion deadlock, try again */
484 do_xmote(gl, gh, gl->gl_target);
486 /* Conversion fails, unlock and try again */
489 do_xmote(gl, gh, LM_ST_UNLOCKED);
491 default: /* Everything else */
492 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
495 spin_unlock(&gl->gl_spin);
499 /* Fast path - we got what we asked for */
500 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
501 gfs2_demote_wake(gl);
502 if (state != LM_ST_UNLOCKED) {
503 if (glops->go_xmote_bh) {
504 spin_unlock(&gl->gl_spin);
505 rv = glops->go_xmote_bh(gl, gh);
506 spin_lock(&gl->gl_spin);
517 clear_bit(GLF_LOCK, &gl->gl_flags);
519 spin_unlock(&gl->gl_spin);
523 * do_xmote - Calls the DLM to change the state of a lock
524 * @gl: The lock state
525 * @gh: The holder (only for promotes)
526 * @target: The target lock state
530 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
531 __releases(&gl->gl_spin)
532 __acquires(&gl->gl_spin)
534 const struct gfs2_glock_operations *glops = gl->gl_ops;
535 struct gfs2_sbd *sdp = gl->gl_sbd;
536 unsigned int lck_flags = gh ? gh->gh_flags : 0;
539 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
541 GLOCK_BUG_ON(gl, gl->gl_state == target);
542 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
543 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
545 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
546 do_error(gl, 0); /* Fail queued try locks */
549 set_bit(GLF_BLOCKING, &gl->gl_flags);
550 if ((gl->gl_req == LM_ST_UNLOCKED) ||
551 (gl->gl_state == LM_ST_EXCLUSIVE) ||
552 (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
553 clear_bit(GLF_BLOCKING, &gl->gl_flags);
554 spin_unlock(&gl->gl_spin);
555 if (glops->go_xmote_th)
556 glops->go_xmote_th(gl);
557 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
558 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
559 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
562 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
564 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
565 GLOCK_BUG_ON(gl, ret);
566 } else { /* lock_nolock */
567 finish_xmote(gl, target);
568 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
572 spin_lock(&gl->gl_spin);
576 * find_first_holder - find the first "holder" gh
580 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
582 struct gfs2_holder *gh;
584 if (!list_empty(&gl->gl_holders)) {
585 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
586 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
593 * run_queue - do all outstanding tasks related to a glock
594 * @gl: The glock in question
595 * @nonblock: True if we must not block in run_queue
599 static void run_queue(struct gfs2_glock *gl, const int nonblock)
600 __releases(&gl->gl_spin)
601 __acquires(&gl->gl_spin)
603 struct gfs2_holder *gh = NULL;
606 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
609 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
611 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
612 gl->gl_demote_state != gl->gl_state) {
613 if (find_first_holder(gl))
617 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
618 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
619 gl->gl_target = gl->gl_demote_state;
621 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
622 gfs2_demote_wake(gl);
623 ret = do_promote(gl);
628 gh = find_first_waiter(gl);
629 gl->gl_target = gh->gh_state;
630 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
631 do_error(gl, 0); /* Fail queued try locks */
633 do_xmote(gl, gh, gl->gl_target);
638 clear_bit(GLF_LOCK, &gl->gl_flags);
639 smp_mb__after_clear_bit();
641 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
642 gfs2_glock_put_nolock(gl);
646 clear_bit(GLF_LOCK, &gl->gl_flags);
647 smp_mb__after_clear_bit();
651 static void delete_work_func(struct work_struct *work)
653 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
654 struct gfs2_sbd *sdp = gl->gl_sbd;
655 struct gfs2_inode *ip;
657 u64 no_addr = gl->gl_name.ln_number;
660 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
663 inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
665 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
666 if (inode && !IS_ERR(inode)) {
667 d_prune_aliases(inode);
673 static void glock_work_func(struct work_struct *work)
675 unsigned long delay = 0;
676 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
679 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
680 finish_xmote(gl, gl->gl_reply);
683 spin_lock(&gl->gl_spin);
684 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
685 gl->gl_state != LM_ST_UNLOCKED &&
686 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
687 unsigned long holdtime, now = jiffies;
689 holdtime = gl->gl_tchange + gl->gl_hold_time;
690 if (time_before(now, holdtime))
691 delay = holdtime - now;
694 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
695 set_bit(GLF_DEMOTE, &gl->gl_flags);
699 spin_unlock(&gl->gl_spin);
703 if (gl->gl_name.ln_type != LM_TYPE_INODE)
705 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
713 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
714 * @sdp: The GFS2 superblock
715 * @number: the lock number
716 * @glops: The glock_operations to use
717 * @create: If 0, don't create the glock if it doesn't exist
718 * @glp: the glock is returned here
720 * This does not lock a glock, just finds/creates structures for one.
725 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
726 const struct gfs2_glock_operations *glops, int create,
727 struct gfs2_glock **glp)
729 struct super_block *s = sdp->sd_vfs;
730 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
731 struct gfs2_glock *gl, *tmp;
732 unsigned int hash = gl_hash(sdp, &name);
733 struct address_space *mapping;
734 struct kmem_cache *cachep;
737 gl = search_bucket(hash, sdp, &name);
746 if (glops->go_flags & GLOF_ASPACE)
747 cachep = gfs2_glock_aspace_cachep;
749 cachep = gfs2_glock_cachep;
750 gl = kmem_cache_alloc(cachep, GFP_KERNEL);
754 atomic_inc(&sdp->sd_glock_disposal);
758 atomic_set(&gl->gl_ref, 1);
759 gl->gl_state = LM_ST_UNLOCKED;
760 gl->gl_target = LM_ST_UNLOCKED;
761 gl->gl_demote_state = LM_ST_EXCLUSIVE;
764 gl->gl_dstamp = ktime_set(0, 0);
766 /* We use the global stats to estimate the initial per-glock stats */
767 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
769 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
770 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
771 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
772 gl->gl_lksb.sb_lvbptr = gl->gl_lvb;
773 gl->gl_tchange = jiffies;
774 gl->gl_object = NULL;
775 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
776 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
777 INIT_WORK(&gl->gl_delete, delete_work_func);
779 mapping = gfs2_glock2aspace(gl);
781 mapping->a_ops = &gfs2_meta_aops;
782 mapping->host = s->s_bdev->bd_inode;
784 mapping_set_gfp_mask(mapping, GFP_NOFS);
785 mapping->assoc_mapping = NULL;
786 mapping->backing_dev_info = s->s_bdi;
787 mapping->writeback_index = 0;
790 spin_lock_bucket(hash);
791 tmp = search_bucket(hash, sdp, &name);
793 spin_unlock_bucket(hash);
794 kmem_cache_free(cachep, gl);
795 atomic_dec(&sdp->sd_glock_disposal);
798 hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]);
799 spin_unlock_bucket(hash);
808 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
810 * @state: the state we're requesting
811 * @flags: the modifier flags
812 * @gh: the holder structure
816 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
817 struct gfs2_holder *gh)
819 INIT_LIST_HEAD(&gh->gh_list);
821 gh->gh_ip = (unsigned long)__builtin_return_address(0);
822 gh->gh_owner_pid = get_pid(task_pid(current));
823 gh->gh_state = state;
824 gh->gh_flags = flags;
831 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
832 * @state: the state we're requesting
833 * @flags: the modifier flags
834 * @gh: the holder structure
836 * Don't mess with the glock.
840 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
842 gh->gh_state = state;
843 gh->gh_flags = flags;
845 gh->gh_ip = (unsigned long)__builtin_return_address(0);
846 if (gh->gh_owner_pid)
847 put_pid(gh->gh_owner_pid);
848 gh->gh_owner_pid = get_pid(task_pid(current));
852 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
853 * @gh: the holder structure
857 void gfs2_holder_uninit(struct gfs2_holder *gh)
859 put_pid(gh->gh_owner_pid);
860 gfs2_glock_put(gh->gh_gl);
866 * gfs2_glock_holder_wait
869 * This function and gfs2_glock_demote_wait both show up in the WCHAN
870 * field. Thus I've separated these otherwise identical functions in
871 * order to be more informative to the user.
874 static int gfs2_glock_holder_wait(void *word)
880 static int gfs2_glock_demote_wait(void *word)
886 static void wait_on_holder(struct gfs2_holder *gh)
888 unsigned long time1 = jiffies;
891 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
892 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
893 /* Lengthen the minimum hold time. */
894 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
899 static void wait_on_demote(struct gfs2_glock *gl)
902 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
906 * handle_callback - process a demote request
908 * @state: the state the caller wants us to change to
910 * There are only two requests that we are going to see in actual
911 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
914 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
917 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
919 set_bit(bit, &gl->gl_flags);
920 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
921 gl->gl_demote_state = state;
922 gl->gl_demote_time = jiffies;
923 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
924 gl->gl_demote_state != state) {
925 gl->gl_demote_state = LM_ST_UNLOCKED;
927 if (gl->gl_ops->go_callback)
928 gl->gl_ops->go_callback(gl);
929 trace_gfs2_demote_rq(gl);
933 * gfs2_glock_wait - wait on a glock acquisition
934 * @gh: the glock holder
936 * Returns: 0 on success
939 int gfs2_glock_wait(struct gfs2_holder *gh)
945 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
947 struct va_format vaf;
953 struct gfs2_glock_iter *gi = seq->private;
954 vsprintf(gi->string, fmt, args);
955 seq_puts(seq, gi->string);
960 printk(KERN_ERR " %pV", &vaf);
967 * add_to_queue - Add a holder to the wait queue (but look for recursion)
968 * @gh: the holder structure to add
970 * Eventually we should move the recursive locking trap to a
971 * debugging option or something like that. This is the fast
972 * path and needs to have the minimum number of distractions.
976 static inline void add_to_queue(struct gfs2_holder *gh)
977 __releases(&gl->gl_spin)
978 __acquires(&gl->gl_spin)
980 struct gfs2_glock *gl = gh->gh_gl;
981 struct gfs2_sbd *sdp = gl->gl_sbd;
982 struct list_head *insert_pt = NULL;
983 struct gfs2_holder *gh2;
986 BUG_ON(gh->gh_owner_pid == NULL);
987 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
990 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
991 if (test_bit(GLF_LOCK, &gl->gl_flags))
993 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
997 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
998 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
999 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
1000 goto trap_recursive;
1002 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
1003 !may_grant(gl, gh)) {
1005 gh->gh_error = GLR_TRYFAILED;
1006 gfs2_holder_wake(gh);
1009 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
1011 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
1012 insert_pt = &gh2->gh_list;
1014 set_bit(GLF_QUEUED, &gl->gl_flags);
1015 trace_gfs2_glock_queue(gh, 1);
1016 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
1017 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
1018 if (likely(insert_pt == NULL)) {
1019 list_add_tail(&gh->gh_list, &gl->gl_holders);
1020 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1024 list_add_tail(&gh->gh_list, insert_pt);
1026 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1027 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1028 spin_unlock(&gl->gl_spin);
1029 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1030 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1031 spin_lock(&gl->gl_spin);
1036 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
1037 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1038 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1039 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1040 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
1041 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
1042 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1043 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1044 __dump_glock(NULL, gl);
1049 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1050 * @gh: the holder structure
1052 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1054 * Returns: 0, GLR_TRYFAILED, or errno on failure
1057 int gfs2_glock_nq(struct gfs2_holder *gh)
1059 struct gfs2_glock *gl = gh->gh_gl;
1060 struct gfs2_sbd *sdp = gl->gl_sbd;
1063 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1066 if (test_bit(GLF_LRU, &gl->gl_flags))
1067 gfs2_glock_remove_from_lru(gl);
1069 spin_lock(&gl->gl_spin);
1071 if ((LM_FLAG_NOEXP & gh->gh_flags) &&
1072 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1073 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1075 spin_unlock(&gl->gl_spin);
1077 if (!(gh->gh_flags & GL_ASYNC))
1078 error = gfs2_glock_wait(gh);
1084 * gfs2_glock_poll - poll to see if an async request has been completed
1087 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1090 int gfs2_glock_poll(struct gfs2_holder *gh)
1092 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1096 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1097 * @gh: the glock holder
1101 void gfs2_glock_dq(struct gfs2_holder *gh)
1103 struct gfs2_glock *gl = gh->gh_gl;
1104 const struct gfs2_glock_operations *glops = gl->gl_ops;
1108 spin_lock(&gl->gl_spin);
1109 if (gh->gh_flags & GL_NOCACHE)
1110 handle_callback(gl, LM_ST_UNLOCKED, 0);
1112 list_del_init(&gh->gh_list);
1113 if (find_first_holder(gl) == NULL) {
1114 if (glops->go_unlock) {
1115 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1116 spin_unlock(&gl->gl_spin);
1117 glops->go_unlock(gh);
1118 spin_lock(&gl->gl_spin);
1119 clear_bit(GLF_LOCK, &gl->gl_flags);
1121 if (list_empty(&gl->gl_holders) &&
1122 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1123 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1126 if (!test_bit(GLF_LFLUSH, &gl->gl_flags))
1127 __gfs2_glock_schedule_for_reclaim(gl);
1128 trace_gfs2_glock_queue(gh, 0);
1129 spin_unlock(&gl->gl_spin);
1130 if (likely(fast_path))
1133 gfs2_glock_hold(gl);
1134 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1135 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1136 gl->gl_name.ln_type == LM_TYPE_INODE)
1137 delay = gl->gl_hold_time;
1138 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1142 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1144 struct gfs2_glock *gl = gh->gh_gl;
1150 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1151 * @gh: the holder structure
1155 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1158 gfs2_holder_uninit(gh);
1162 * gfs2_glock_nq_num - acquire a glock based on lock number
1163 * @sdp: the filesystem
1164 * @number: the lock number
1165 * @glops: the glock operations for the type of glock
1166 * @state: the state to acquire the glock in
1167 * @flags: modifier flags for the acquisition
1168 * @gh: the struct gfs2_holder
1173 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1174 const struct gfs2_glock_operations *glops,
1175 unsigned int state, int flags, struct gfs2_holder *gh)
1177 struct gfs2_glock *gl;
1180 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1182 error = gfs2_glock_nq_init(gl, state, flags, gh);
1190 * glock_compare - Compare two struct gfs2_glock structures for sorting
1191 * @arg_a: the first structure
1192 * @arg_b: the second structure
1196 static int glock_compare(const void *arg_a, const void *arg_b)
1198 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1199 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1200 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1201 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1203 if (a->ln_number > b->ln_number)
1205 if (a->ln_number < b->ln_number)
1207 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1212 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1213 * @num_gh: the number of structures
1214 * @ghs: an array of struct gfs2_holder structures
1216 * Returns: 0 on success (all glocks acquired),
1217 * errno on failure (no glocks acquired)
1220 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1221 struct gfs2_holder **p)
1226 for (x = 0; x < num_gh; x++)
1229 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1231 for (x = 0; x < num_gh; x++) {
1232 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1234 error = gfs2_glock_nq(p[x]);
1237 gfs2_glock_dq(p[x]);
1246 * gfs2_glock_nq_m - acquire multiple glocks
1247 * @num_gh: the number of structures
1248 * @ghs: an array of struct gfs2_holder structures
1251 * Returns: 0 on success (all glocks acquired),
1252 * errno on failure (no glocks acquired)
1255 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1257 struct gfs2_holder *tmp[4];
1258 struct gfs2_holder **pph = tmp;
1265 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1266 return gfs2_glock_nq(ghs);
1270 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1275 error = nq_m_sync(num_gh, ghs, pph);
1284 * gfs2_glock_dq_m - release multiple glocks
1285 * @num_gh: the number of structures
1286 * @ghs: an array of struct gfs2_holder structures
1290 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1293 gfs2_glock_dq(&ghs[num_gh]);
1297 * gfs2_glock_dq_uninit_m - release multiple glocks
1298 * @num_gh: the number of structures
1299 * @ghs: an array of struct gfs2_holder structures
1303 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1306 gfs2_glock_dq_uninit(&ghs[num_gh]);
1309 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1311 unsigned long delay = 0;
1312 unsigned long holdtime;
1313 unsigned long now = jiffies;
1315 gfs2_glock_hold(gl);
1316 holdtime = gl->gl_tchange + gl->gl_hold_time;
1317 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1318 gl->gl_name.ln_type == LM_TYPE_INODE) {
1319 if (time_before(now, holdtime))
1320 delay = holdtime - now;
1321 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1322 delay = gl->gl_hold_time;
1325 spin_lock(&gl->gl_spin);
1326 handle_callback(gl, state, delay);
1327 spin_unlock(&gl->gl_spin);
1328 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1333 * gfs2_should_freeze - Figure out if glock should be frozen
1334 * @gl: The glock in question
1336 * Glocks are not frozen if (a) the result of the dlm operation is
1337 * an error, (b) the locking operation was an unlock operation or
1338 * (c) if there is a "noexp" flagged request anywhere in the queue
1340 * Returns: 1 if freezing should occur, 0 otherwise
1343 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1345 const struct gfs2_holder *gh;
1347 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1349 if (gl->gl_target == LM_ST_UNLOCKED)
1352 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1353 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1355 if (LM_FLAG_NOEXP & gh->gh_flags)
1363 * gfs2_glock_complete - Callback used by locking
1364 * @gl: Pointer to the glock
1365 * @ret: The return value from the dlm
1367 * The gl_reply field is under the gl_spin lock so that it is ok
1368 * to use a bitfield shared with other glock state fields.
1371 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1373 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1375 spin_lock(&gl->gl_spin);
1378 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1379 if (gfs2_should_freeze(gl)) {
1380 set_bit(GLF_FROZEN, &gl->gl_flags);
1381 spin_unlock(&gl->gl_spin);
1386 spin_unlock(&gl->gl_spin);
1387 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1389 gfs2_glock_hold(gl);
1390 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1395 static int gfs2_shrink_glock_memory(struct shrinker *shrink,
1396 struct shrink_control *sc)
1398 struct gfs2_glock *gl;
1401 int nr = sc->nr_to_scan;
1402 gfp_t gfp_mask = sc->gfp_mask;
1408 if (!(gfp_mask & __GFP_FS))
1411 spin_lock(&lru_lock);
1412 while(nr && !list_empty(&lru_list)) {
1413 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1414 list_del_init(&gl->gl_lru);
1415 clear_bit(GLF_LRU, &gl->gl_flags);
1416 atomic_dec(&lru_count);
1418 /* Test for being demotable */
1419 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1420 gfs2_glock_hold(gl);
1421 spin_unlock(&lru_lock);
1422 spin_lock(&gl->gl_spin);
1423 may_demote = demote_ok(gl);
1425 handle_callback(gl, LM_ST_UNLOCKED, 0);
1428 clear_bit(GLF_LOCK, &gl->gl_flags);
1429 smp_mb__after_clear_bit();
1430 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1431 gfs2_glock_put_nolock(gl);
1432 spin_unlock(&gl->gl_spin);
1433 spin_lock(&lru_lock);
1437 list_add(&gl->gl_lru, &skipped);
1438 set_bit(GLF_LRU, &gl->gl_flags);
1440 list_splice(&skipped, &lru_list);
1441 atomic_add(nr_skipped, &lru_count);
1442 spin_unlock(&lru_lock);
1444 return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
1447 static struct shrinker glock_shrinker = {
1448 .shrink = gfs2_shrink_glock_memory,
1449 .seeks = DEFAULT_SEEKS,
1453 * examine_bucket - Call a function for glock in a hash bucket
1454 * @examiner: the function
1455 * @sdp: the filesystem
1456 * @bucket: the bucket
1460 static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
1463 struct gfs2_glock *gl;
1464 struct hlist_bl_head *head = &gl_hash_table[hash];
1465 struct hlist_bl_node *pos;
1468 hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
1469 if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref))
1476 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1480 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1481 examine_bucket(examiner, sdp, x);
1486 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1487 * @gl: The glock to thaw
1489 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1490 * so this has to result in the ref count being dropped by one.
1493 static void thaw_glock(struct gfs2_glock *gl)
1495 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1497 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1498 gfs2_glock_hold(gl);
1499 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1504 * clear_glock - look at a glock and see if we can free it from glock cache
1505 * @gl: the glock to look at
1509 static void clear_glock(struct gfs2_glock *gl)
1511 gfs2_glock_remove_from_lru(gl);
1513 spin_lock(&gl->gl_spin);
1514 if (gl->gl_state != LM_ST_UNLOCKED)
1515 handle_callback(gl, LM_ST_UNLOCKED, 0);
1516 spin_unlock(&gl->gl_spin);
1517 gfs2_glock_hold(gl);
1518 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1523 * gfs2_glock_thaw - Thaw any frozen glocks
1524 * @sdp: The super block
1528 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1530 glock_hash_walk(thaw_glock, sdp);
1533 static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1536 spin_lock(&gl->gl_spin);
1537 ret = __dump_glock(seq, gl);
1538 spin_unlock(&gl->gl_spin);
1542 static void dump_glock_func(struct gfs2_glock *gl)
1544 dump_glock(NULL, gl);
1548 * gfs2_gl_hash_clear - Empty out the glock hash table
1549 * @sdp: the filesystem
1550 * @wait: wait until it's all gone
1552 * Called when unmounting the filesystem.
1555 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1557 glock_hash_walk(clear_glock, sdp);
1558 flush_workqueue(glock_workqueue);
1559 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1560 glock_hash_walk(dump_glock_func, sdp);
1563 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1565 struct gfs2_glock *gl = ip->i_gl;
1568 ret = gfs2_truncatei_resume(ip);
1569 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1571 spin_lock(&gl->gl_spin);
1572 clear_bit(GLF_LOCK, &gl->gl_flags);
1574 spin_unlock(&gl->gl_spin);
1577 static const char *state2str(unsigned state)
1580 case LM_ST_UNLOCKED:
1584 case LM_ST_DEFERRED:
1586 case LM_ST_EXCLUSIVE:
1592 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1595 if (flags & LM_FLAG_TRY)
1597 if (flags & LM_FLAG_TRY_1CB)
1599 if (flags & LM_FLAG_NOEXP)
1601 if (flags & LM_FLAG_ANY)
1603 if (flags & LM_FLAG_PRIORITY)
1605 if (flags & GL_ASYNC)
1607 if (flags & GL_EXACT)
1609 if (flags & GL_NOCACHE)
1611 if (test_bit(HIF_HOLDER, &iflags))
1613 if (test_bit(HIF_WAIT, &iflags))
1615 if (test_bit(HIF_FIRST, &iflags))
1622 * dump_holder - print information about a glock holder
1623 * @seq: the seq_file struct
1624 * @gh: the glock holder
1626 * Returns: 0 on success, -ENOBUFS when we run out of space
1629 static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1631 struct task_struct *gh_owner = NULL;
1634 if (gh->gh_owner_pid)
1635 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1636 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1637 state2str(gh->gh_state),
1638 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1640 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1641 gh_owner ? gh_owner->comm : "(ended)",
1646 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1648 const unsigned long *gflags = &gl->gl_flags;
1651 if (test_bit(GLF_LOCK, gflags))
1653 if (test_bit(GLF_DEMOTE, gflags))
1655 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1657 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1659 if (test_bit(GLF_DIRTY, gflags))
1661 if (test_bit(GLF_LFLUSH, gflags))
1663 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1665 if (test_bit(GLF_REPLY_PENDING, gflags))
1667 if (test_bit(GLF_INITIAL, gflags))
1669 if (test_bit(GLF_FROZEN, gflags))
1671 if (test_bit(GLF_QUEUED, gflags))
1673 if (test_bit(GLF_LRU, gflags))
1677 if (test_bit(GLF_BLOCKING, gflags))
1684 * __dump_glock - print information about a glock
1685 * @seq: The seq_file struct
1688 * The file format is as follows:
1689 * One line per object, capital letters are used to indicate objects
1690 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1691 * other objects are indented by a single space and follow the glock to
1692 * which they are related. Fields are indicated by lower case letters
1693 * followed by a colon and the field value, except for strings which are in
1694 * [] so that its possible to see if they are composed of spaces for
1695 * example. The field's are n = number (id of the object), f = flags,
1696 * t = type, s = state, r = refcount, e = error, p = pid.
1698 * Returns: 0 on success, -ENOBUFS when we run out of space
1701 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1703 const struct gfs2_glock_operations *glops = gl->gl_ops;
1704 unsigned long long dtime;
1705 const struct gfs2_holder *gh;
1706 char gflags_buf[32];
1709 dtime = jiffies - gl->gl_demote_time;
1710 dtime *= 1000000/HZ; /* demote time in uSec */
1711 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1713 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",
1714 state2str(gl->gl_state),
1715 gl->gl_name.ln_type,
1716 (unsigned long long)gl->gl_name.ln_number,
1717 gflags2str(gflags_buf, gl),
1718 state2str(gl->gl_target),
1719 state2str(gl->gl_demote_state), dtime,
1720 atomic_read(&gl->gl_ail_count),
1721 atomic_read(&gl->gl_revokes),
1722 atomic_read(&gl->gl_ref), gl->gl_hold_time);
1724 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1725 error = dump_holder(seq, gh);
1729 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1730 error = glops->go_dump(seq, gl);
1735 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1737 struct gfs2_glock *gl = iter_ptr;
1739 seq_printf(seq, "G: n:%u/%llx rtt:%lld/%lld rttb:%lld/%lld irt:%lld/%lld dcnt: %lld qcnt: %lld\n",
1740 gl->gl_name.ln_type,
1741 (unsigned long long)gl->gl_name.ln_number,
1742 (long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1743 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1744 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1745 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1746 (long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1747 (long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1748 (long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1749 (long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1753 static const char *gfs2_gltype[] = {
1767 static const char *gfs2_stype[] = {
1768 [GFS2_LKS_SRTT] = "srtt",
1769 [GFS2_LKS_SRTTVAR] = "srttvar",
1770 [GFS2_LKS_SRTTB] = "srttb",
1771 [GFS2_LKS_SRTTVARB] = "srttvarb",
1772 [GFS2_LKS_SIRT] = "sirt",
1773 [GFS2_LKS_SIRTVAR] = "sirtvar",
1774 [GFS2_LKS_DCOUNT] = "dlm",
1775 [GFS2_LKS_QCOUNT] = "queue",
1778 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1780 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1782 struct gfs2_glock_iter *gi = seq->private;
1783 struct gfs2_sbd *sdp = gi->sdp;
1784 unsigned index = gi->hash >> 3;
1785 unsigned subindex = gi->hash & 0x07;
1789 if (index == 0 && subindex != 0)
1792 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1793 (index == 0) ? "cpu": gfs2_stype[subindex]);
1795 for_each_possible_cpu(i) {
1796 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1800 value = lkstats->lkstats[index - 1].stats[subindex];
1802 seq_printf(seq, " %15lld", (long long)value);
1804 seq_putc(seq, '\n');
1808 int __init gfs2_glock_init(void)
1811 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1812 INIT_HLIST_BL_HEAD(&gl_hash_table[i]);
1815 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1816 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1817 if (IS_ERR(glock_workqueue))
1818 return PTR_ERR(glock_workqueue);
1819 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1820 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1822 if (IS_ERR(gfs2_delete_workqueue)) {
1823 destroy_workqueue(glock_workqueue);
1824 return PTR_ERR(gfs2_delete_workqueue);
1827 register_shrinker(&glock_shrinker);
1832 void gfs2_glock_exit(void)
1834 unregister_shrinker(&glock_shrinker);
1835 destroy_workqueue(glock_workqueue);
1836 destroy_workqueue(gfs2_delete_workqueue);
1839 static inline struct gfs2_glock *glock_hash_chain(unsigned hash)
1841 return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]),
1842 struct gfs2_glock, gl_list);
1845 static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl)
1847 return hlist_bl_entry(rcu_dereference(gl->gl_list.next),
1848 struct gfs2_glock, gl_list);
1851 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1853 struct gfs2_glock *gl;
1858 gi->gl = glock_hash_next(gl);
1861 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1865 gi->gl = glock_hash_chain(gi->hash);
1868 while (gi->gl == NULL) {
1870 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1874 gi->gl = glock_hash_chain(gi->hash);
1877 /* Skip entries for other sb and dead entries */
1878 } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0);
1883 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1885 struct gfs2_glock_iter *gi = seq->private;
1888 if (gi->last_pos <= *pos)
1889 n = gi->nhash + (*pos - gi->last_pos);
1897 if (gfs2_glock_iter_next(gi))
1901 gi->last_pos = *pos;
1905 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1908 struct gfs2_glock_iter *gi = seq->private;
1911 gi->last_pos = *pos;
1912 if (gfs2_glock_iter_next(gi))
1918 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1920 struct gfs2_glock_iter *gi = seq->private;
1927 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1929 return dump_glock(seq, iter_ptr);
1932 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1934 struct gfs2_glock_iter *gi = seq->private;
1937 if (*pos >= GFS2_NR_SBSTATS)
1940 return SEQ_START_TOKEN;
1943 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1946 struct gfs2_glock_iter *gi = seq->private;
1949 if (gi->hash >= GFS2_NR_SBSTATS) {
1953 return SEQ_START_TOKEN;
1956 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1961 static const struct seq_operations gfs2_glock_seq_ops = {
1962 .start = gfs2_glock_seq_start,
1963 .next = gfs2_glock_seq_next,
1964 .stop = gfs2_glock_seq_stop,
1965 .show = gfs2_glock_seq_show,
1968 static const struct seq_operations gfs2_glstats_seq_ops = {
1969 .start = gfs2_glock_seq_start,
1970 .next = gfs2_glock_seq_next,
1971 .stop = gfs2_glock_seq_stop,
1972 .show = gfs2_glstats_seq_show,
1975 static const struct seq_operations gfs2_sbstats_seq_ops = {
1976 .start = gfs2_sbstats_seq_start,
1977 .next = gfs2_sbstats_seq_next,
1978 .stop = gfs2_sbstats_seq_stop,
1979 .show = gfs2_sbstats_seq_show,
1982 static int gfs2_glocks_open(struct inode *inode, struct file *file)
1984 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1985 sizeof(struct gfs2_glock_iter));
1987 struct seq_file *seq = file->private_data;
1988 struct gfs2_glock_iter *gi = seq->private;
1989 gi->sdp = inode->i_private;
1990 seq->buf = kmalloc(8*PAGE_SIZE, GFP_KERNEL | __GFP_NOWARN);
1992 seq->size = 8*PAGE_SIZE;
1997 static int gfs2_glstats_open(struct inode *inode, struct file *file)
1999 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
2000 sizeof(struct gfs2_glock_iter));
2002 struct seq_file *seq = file->private_data;
2003 struct gfs2_glock_iter *gi = seq->private;
2004 gi->sdp = inode->i_private;
2005 seq->buf = kmalloc(8*PAGE_SIZE, GFP_KERNEL | __GFP_NOWARN);
2007 seq->size = 8*PAGE_SIZE;
2012 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
2014 int ret = seq_open_private(file, &gfs2_sbstats_seq_ops,
2015 sizeof(struct gfs2_glock_iter));
2017 struct seq_file *seq = file->private_data;
2018 struct gfs2_glock_iter *gi = seq->private;
2019 gi->sdp = inode->i_private;
2024 static const struct file_operations gfs2_glocks_fops = {
2025 .owner = THIS_MODULE,
2026 .open = gfs2_glocks_open,
2028 .llseek = seq_lseek,
2029 .release = seq_release_private,
2032 static const struct file_operations gfs2_glstats_fops = {
2033 .owner = THIS_MODULE,
2034 .open = gfs2_glstats_open,
2036 .llseek = seq_lseek,
2037 .release = seq_release_private,
2040 static const struct file_operations gfs2_sbstats_fops = {
2041 .owner = THIS_MODULE,
2042 .open = gfs2_sbstats_open,
2044 .llseek = seq_lseek,
2045 .release = seq_release_private,
2048 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
2050 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
2051 if (!sdp->debugfs_dir)
2053 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
2055 sdp->debugfs_dir, sdp,
2057 if (!sdp->debugfs_dentry_glocks)
2060 sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
2062 sdp->debugfs_dir, sdp,
2063 &gfs2_glstats_fops);
2064 if (!sdp->debugfs_dentry_glstats)
2067 sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
2069 sdp->debugfs_dir, sdp,
2070 &gfs2_sbstats_fops);
2071 if (!sdp->debugfs_dentry_sbstats)
2076 gfs2_delete_debugfs_file(sdp);
2080 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2082 if (sdp->debugfs_dir) {
2083 if (sdp->debugfs_dentry_glocks) {
2084 debugfs_remove(sdp->debugfs_dentry_glocks);
2085 sdp->debugfs_dentry_glocks = NULL;
2087 if (sdp->debugfs_dentry_glstats) {
2088 debugfs_remove(sdp->debugfs_dentry_glstats);
2089 sdp->debugfs_dentry_glstats = NULL;
2091 if (sdp->debugfs_dentry_sbstats) {
2092 debugfs_remove(sdp->debugfs_dentry_sbstats);
2093 sdp->debugfs_dentry_sbstats = NULL;
2095 debugfs_remove(sdp->debugfs_dir);
2096 sdp->debugfs_dir = NULL;
2100 int gfs2_register_debugfs(void)
2102 gfs2_root = debugfs_create_dir("gfs2", NULL);
2103 return gfs2_root ? 0 : -ENOMEM;
2106 void gfs2_unregister_debugfs(void)
2108 debugfs_remove(gfs2_root);