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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/buffer_head.h>
16 #include <linux/delay.h>
17 #include <linux/sort.h>
18 #include <linux/jhash.h>
19 #include <linux/kallsyms.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <linux/list.h>
22 #include <linux/wait.h>
23 #include <linux/module.h>
24 #include <asm/uaccess.h>
25 #include <linux/seq_file.h>
26 #include <linux/debugfs.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/workqueue.h>
30 #include <linux/jiffies.h>
31 #include <linux/rcupdate.h>
32 #include <linux/rculist_bl.h>
33 #include <linux/bit_spinlock.h>
34 #include <linux/percpu.h>
35 #include <linux/list_sort.h>
36 #include <linux/lockref.h>
49 #define CREATE_TRACE_POINTS
50 #include "trace_gfs2.h"
52 struct gfs2_glock_iter {
53 int hash; /* hash bucket index */
54 unsigned nhash; /* Index within current bucket */
55 struct gfs2_sbd *sdp; /* incore superblock */
56 struct gfs2_glock *gl; /* current glock struct */
57 loff_t last_pos; /* last position */
60 typedef void (*glock_examiner) (struct gfs2_glock * gl);
62 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
64 static struct dentry *gfs2_root;
65 static struct workqueue_struct *glock_workqueue;
66 struct workqueue_struct *gfs2_delete_workqueue;
67 static LIST_HEAD(lru_list);
68 static atomic_t lru_count = ATOMIC_INIT(0);
69 static DEFINE_SPINLOCK(lru_lock);
71 #define GFS2_GL_HASH_SHIFT 15
72 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
73 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
75 static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE];
76 static struct dentry *gfs2_root;
79 * gl_hash() - Turn glock number into hash bucket number
80 * @lock: The glock number
82 * Returns: The number of the corresponding hash bucket
85 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
86 const struct lm_lockname *name)
90 h = jhash(&name->ln_number, sizeof(u64), 0);
91 h = jhash(&name->ln_type, sizeof(unsigned int), h);
92 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
93 h &= GFS2_GL_HASH_MASK;
98 static inline void spin_lock_bucket(unsigned int hash)
100 hlist_bl_lock(&gl_hash_table[hash]);
103 static inline void spin_unlock_bucket(unsigned int hash)
105 hlist_bl_unlock(&gl_hash_table[hash]);
108 static void gfs2_glock_dealloc(struct rcu_head *rcu)
110 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
112 if (gl->gl_ops->go_flags & GLOF_ASPACE) {
113 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
115 kfree(gl->gl_lksb.sb_lvbptr);
116 kmem_cache_free(gfs2_glock_cachep, gl);
120 void gfs2_glock_free(struct gfs2_glock *gl)
122 struct gfs2_sbd *sdp = gl->gl_sbd;
124 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
125 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
126 wake_up(&sdp->sd_glock_wait);
130 * gfs2_glock_hold() - increment reference count on glock
131 * @gl: The glock to hold
135 static void gfs2_glock_hold(struct gfs2_glock *gl)
137 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
138 lockref_get(&gl->gl_lockref);
142 * demote_ok - Check to see if it's ok to unlock a glock
145 * Returns: 1 if it's ok
148 static int demote_ok(const struct gfs2_glock *gl)
150 const struct gfs2_glock_operations *glops = gl->gl_ops;
152 if (gl->gl_state == LM_ST_UNLOCKED)
154 if (!list_empty(&gl->gl_holders))
156 if (glops->go_demote_ok)
157 return glops->go_demote_ok(gl);
162 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
164 spin_lock(&lru_lock);
166 if (!list_empty(&gl->gl_lru))
167 list_del_init(&gl->gl_lru);
169 atomic_inc(&lru_count);
171 list_add_tail(&gl->gl_lru, &lru_list);
172 set_bit(GLF_LRU, &gl->gl_flags);
173 spin_unlock(&lru_lock);
176 static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
178 if (!list_empty(&gl->gl_lru)) {
179 list_del_init(&gl->gl_lru);
180 atomic_dec(&lru_count);
181 clear_bit(GLF_LRU, &gl->gl_flags);
185 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
187 spin_lock(&lru_lock);
188 __gfs2_glock_remove_from_lru(gl);
189 spin_unlock(&lru_lock);
193 * gfs2_glock_put() - Decrement reference count on glock
194 * @gl: The glock to put
198 void gfs2_glock_put(struct gfs2_glock *gl)
200 struct gfs2_sbd *sdp = gl->gl_sbd;
201 struct address_space *mapping = gfs2_glock2aspace(gl);
203 if (lockref_put_or_lock(&gl->gl_lockref))
206 lockref_mark_dead(&gl->gl_lockref);
208 spin_lock(&lru_lock);
209 __gfs2_glock_remove_from_lru(gl);
210 spin_unlock(&lru_lock);
211 spin_unlock(&gl->gl_lockref.lock);
212 spin_lock_bucket(gl->gl_hash);
213 hlist_bl_del_rcu(&gl->gl_list);
214 spin_unlock_bucket(gl->gl_hash);
215 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
216 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
217 trace_gfs2_glock_put(gl);
218 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
222 * search_bucket() - Find struct gfs2_glock by lock number
223 * @bucket: the bucket to search
224 * @name: The lock name
226 * Returns: NULL, or the struct gfs2_glock with the requested number
229 static struct gfs2_glock *search_bucket(unsigned int hash,
230 const struct gfs2_sbd *sdp,
231 const struct lm_lockname *name)
233 struct gfs2_glock *gl;
234 struct hlist_bl_node *h;
236 hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
237 if (!lm_name_equal(&gl->gl_name, name))
239 if (gl->gl_sbd != sdp)
241 if (lockref_get_not_dead(&gl->gl_lockref))
249 * may_grant - check if its ok to grant a new lock
251 * @gh: The lock request which we wish to grant
253 * Returns: true if its ok to grant the lock
256 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
258 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
259 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
260 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
262 if (gl->gl_state == gh->gh_state)
264 if (gh->gh_flags & GL_EXACT)
266 if (gl->gl_state == LM_ST_EXCLUSIVE) {
267 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
269 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
272 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
277 static void gfs2_holder_wake(struct gfs2_holder *gh)
279 clear_bit(HIF_WAIT, &gh->gh_iflags);
280 smp_mb__after_atomic();
281 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
285 * do_error - Something unexpected has happened during a lock request
289 static inline void do_error(struct gfs2_glock *gl, const int ret)
291 struct gfs2_holder *gh, *tmp;
293 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
294 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
296 if (ret & LM_OUT_ERROR)
298 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
299 gh->gh_error = GLR_TRYFAILED;
302 list_del_init(&gh->gh_list);
303 trace_gfs2_glock_queue(gh, 0);
304 gfs2_holder_wake(gh);
309 * do_promote - promote as many requests as possible on the current queue
312 * Returns: 1 if there is a blocked holder at the head of the list, or 2
313 * if a type specific operation is underway.
316 static int do_promote(struct gfs2_glock *gl)
317 __releases(&gl->gl_spin)
318 __acquires(&gl->gl_spin)
320 const struct gfs2_glock_operations *glops = gl->gl_ops;
321 struct gfs2_holder *gh, *tmp;
325 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
326 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
328 if (may_grant(gl, gh)) {
329 if (gh->gh_list.prev == &gl->gl_holders &&
331 spin_unlock(&gl->gl_spin);
332 /* FIXME: eliminate this eventually */
333 ret = glops->go_lock(gh);
334 spin_lock(&gl->gl_spin);
339 list_del_init(&gh->gh_list);
340 trace_gfs2_glock_queue(gh, 0);
341 gfs2_holder_wake(gh);
344 set_bit(HIF_HOLDER, &gh->gh_iflags);
345 trace_gfs2_promote(gh, 1);
346 gfs2_holder_wake(gh);
349 set_bit(HIF_HOLDER, &gh->gh_iflags);
350 trace_gfs2_promote(gh, 0);
351 gfs2_holder_wake(gh);
354 if (gh->gh_list.prev == &gl->gl_holders)
363 * find_first_waiter - find the first gh that's waiting for the glock
367 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
369 struct gfs2_holder *gh;
371 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
372 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
379 * state_change - record that the glock is now in a different state
381 * @new_state the new state
385 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
389 held1 = (gl->gl_state != LM_ST_UNLOCKED);
390 held2 = (new_state != LM_ST_UNLOCKED);
392 if (held1 != held2) {
393 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
395 gl->gl_lockref.count++;
397 gl->gl_lockref.count--;
399 if (held1 && held2 && list_empty(&gl->gl_holders))
400 clear_bit(GLF_QUEUED, &gl->gl_flags);
402 if (new_state != gl->gl_target)
403 /* shorten our minimum hold time */
404 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
406 gl->gl_state = new_state;
407 gl->gl_tchange = jiffies;
410 static void gfs2_demote_wake(struct gfs2_glock *gl)
412 gl->gl_demote_state = LM_ST_EXCLUSIVE;
413 clear_bit(GLF_DEMOTE, &gl->gl_flags);
414 smp_mb__after_atomic();
415 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
419 * finish_xmote - The DLM has replied to one of our lock requests
421 * @ret: The status from the DLM
425 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
427 const struct gfs2_glock_operations *glops = gl->gl_ops;
428 struct gfs2_holder *gh;
429 unsigned state = ret & LM_OUT_ST_MASK;
432 spin_lock(&gl->gl_spin);
433 trace_gfs2_glock_state_change(gl, state);
434 state_change(gl, state);
435 gh = find_first_waiter(gl);
437 /* Demote to UN request arrived during demote to SH or DF */
438 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
439 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
440 gl->gl_target = LM_ST_UNLOCKED;
442 /* Check for state != intended state */
443 if (unlikely(state != gl->gl_target)) {
444 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
445 /* move to back of queue and try next entry */
446 if (ret & LM_OUT_CANCELED) {
447 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
448 list_move_tail(&gh->gh_list, &gl->gl_holders);
449 gh = find_first_waiter(gl);
450 gl->gl_target = gh->gh_state;
453 /* Some error or failed "try lock" - report it */
454 if ((ret & LM_OUT_ERROR) ||
455 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
456 gl->gl_target = gl->gl_state;
462 /* Unlocked due to conversion deadlock, try again */
465 do_xmote(gl, gh, gl->gl_target);
467 /* Conversion fails, unlock and try again */
470 do_xmote(gl, gh, LM_ST_UNLOCKED);
472 default: /* Everything else */
473 pr_err("wanted %u got %u\n", gl->gl_target, state);
476 spin_unlock(&gl->gl_spin);
480 /* Fast path - we got what we asked for */
481 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
482 gfs2_demote_wake(gl);
483 if (state != LM_ST_UNLOCKED) {
484 if (glops->go_xmote_bh) {
485 spin_unlock(&gl->gl_spin);
486 rv = glops->go_xmote_bh(gl, gh);
487 spin_lock(&gl->gl_spin);
498 clear_bit(GLF_LOCK, &gl->gl_flags);
500 spin_unlock(&gl->gl_spin);
504 * do_xmote - Calls the DLM to change the state of a lock
505 * @gl: The lock state
506 * @gh: The holder (only for promotes)
507 * @target: The target lock state
511 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
512 __releases(&gl->gl_spin)
513 __acquires(&gl->gl_spin)
515 const struct gfs2_glock_operations *glops = gl->gl_ops;
516 struct gfs2_sbd *sdp = gl->gl_sbd;
517 unsigned int lck_flags = gh ? gh->gh_flags : 0;
520 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
522 GLOCK_BUG_ON(gl, gl->gl_state == target);
523 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
524 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
526 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
527 do_error(gl, 0); /* Fail queued try locks */
530 set_bit(GLF_BLOCKING, &gl->gl_flags);
531 if ((gl->gl_req == LM_ST_UNLOCKED) ||
532 (gl->gl_state == LM_ST_EXCLUSIVE) ||
533 (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
534 clear_bit(GLF_BLOCKING, &gl->gl_flags);
535 spin_unlock(&gl->gl_spin);
538 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
539 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
540 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
543 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
545 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
547 pr_err("lm_lock ret %d\n", ret);
550 } else { /* lock_nolock */
551 finish_xmote(gl, target);
552 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
556 spin_lock(&gl->gl_spin);
560 * find_first_holder - find the first "holder" gh
564 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
566 struct gfs2_holder *gh;
568 if (!list_empty(&gl->gl_holders)) {
569 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
570 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
577 * run_queue - do all outstanding tasks related to a glock
578 * @gl: The glock in question
579 * @nonblock: True if we must not block in run_queue
583 static void run_queue(struct gfs2_glock *gl, const int nonblock)
584 __releases(&gl->gl_spin)
585 __acquires(&gl->gl_spin)
587 struct gfs2_holder *gh = NULL;
590 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
593 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
595 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
596 gl->gl_demote_state != gl->gl_state) {
597 if (find_first_holder(gl))
601 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
602 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
603 gl->gl_target = gl->gl_demote_state;
605 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
606 gfs2_demote_wake(gl);
607 ret = do_promote(gl);
612 gh = find_first_waiter(gl);
613 gl->gl_target = gh->gh_state;
614 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
615 do_error(gl, 0); /* Fail queued try locks */
617 do_xmote(gl, gh, gl->gl_target);
622 clear_bit(GLF_LOCK, &gl->gl_flags);
623 smp_mb__after_atomic();
624 gl->gl_lockref.count++;
625 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
626 gl->gl_lockref.count--;
630 clear_bit(GLF_LOCK, &gl->gl_flags);
631 smp_mb__after_atomic();
635 static void delete_work_func(struct work_struct *work)
637 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
638 struct gfs2_sbd *sdp = gl->gl_sbd;
639 struct gfs2_inode *ip;
641 u64 no_addr = gl->gl_name.ln_number;
644 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
647 inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
649 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
650 if (inode && !IS_ERR(inode)) {
651 d_prune_aliases(inode);
657 static void glock_work_func(struct work_struct *work)
659 unsigned long delay = 0;
660 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
663 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
664 finish_xmote(gl, gl->gl_reply);
667 spin_lock(&gl->gl_spin);
668 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
669 gl->gl_state != LM_ST_UNLOCKED &&
670 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
671 unsigned long holdtime, now = jiffies;
673 holdtime = gl->gl_tchange + gl->gl_hold_time;
674 if (time_before(now, holdtime))
675 delay = holdtime - now;
678 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
679 set_bit(GLF_DEMOTE, &gl->gl_flags);
683 spin_unlock(&gl->gl_spin);
687 if (gl->gl_name.ln_type != LM_TYPE_INODE)
689 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
697 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
698 * @sdp: The GFS2 superblock
699 * @number: the lock number
700 * @glops: The glock_operations to use
701 * @create: If 0, don't create the glock if it doesn't exist
702 * @glp: the glock is returned here
704 * This does not lock a glock, just finds/creates structures for one.
709 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
710 const struct gfs2_glock_operations *glops, int create,
711 struct gfs2_glock **glp)
713 struct super_block *s = sdp->sd_vfs;
714 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
715 struct gfs2_glock *gl, *tmp;
716 unsigned int hash = gl_hash(sdp, &name);
717 struct address_space *mapping;
718 struct kmem_cache *cachep;
721 gl = search_bucket(hash, sdp, &name);
730 if (glops->go_flags & GLOF_ASPACE)
731 cachep = gfs2_glock_aspace_cachep;
733 cachep = gfs2_glock_cachep;
734 gl = kmem_cache_alloc(cachep, GFP_NOFS);
738 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
740 if (glops->go_flags & GLOF_LVB) {
741 gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_NOFS);
742 if (!gl->gl_lksb.sb_lvbptr) {
743 kmem_cache_free(cachep, gl);
748 atomic_inc(&sdp->sd_glock_disposal);
752 gl->gl_lockref.count = 1;
753 gl->gl_state = LM_ST_UNLOCKED;
754 gl->gl_target = LM_ST_UNLOCKED;
755 gl->gl_demote_state = LM_ST_EXCLUSIVE;
758 gl->gl_dstamp = ktime_set(0, 0);
760 /* We use the global stats to estimate the initial per-glock stats */
761 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
763 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
764 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
765 gl->gl_tchange = jiffies;
766 gl->gl_object = NULL;
767 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
768 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
769 INIT_WORK(&gl->gl_delete, delete_work_func);
771 mapping = gfs2_glock2aspace(gl);
773 mapping->a_ops = &gfs2_meta_aops;
774 mapping->host = s->s_bdev->bd_inode;
776 mapping_set_gfp_mask(mapping, GFP_NOFS);
777 mapping->private_data = NULL;
778 mapping->backing_dev_info = s->s_bdi;
779 mapping->writeback_index = 0;
782 spin_lock_bucket(hash);
783 tmp = search_bucket(hash, sdp, &name);
785 spin_unlock_bucket(hash);
786 kfree(gl->gl_lksb.sb_lvbptr);
787 kmem_cache_free(cachep, gl);
788 atomic_dec(&sdp->sd_glock_disposal);
791 hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]);
792 spin_unlock_bucket(hash);
801 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
803 * @state: the state we're requesting
804 * @flags: the modifier flags
805 * @gh: the holder structure
809 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
810 struct gfs2_holder *gh)
812 INIT_LIST_HEAD(&gh->gh_list);
814 gh->gh_ip = (unsigned long)__builtin_return_address(0);
815 gh->gh_owner_pid = get_pid(task_pid(current));
816 gh->gh_state = state;
817 gh->gh_flags = flags;
824 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
825 * @state: the state we're requesting
826 * @flags: the modifier flags
827 * @gh: the holder structure
829 * Don't mess with the glock.
833 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
835 gh->gh_state = state;
836 gh->gh_flags = flags;
838 gh->gh_ip = (unsigned long)__builtin_return_address(0);
839 if (gh->gh_owner_pid)
840 put_pid(gh->gh_owner_pid);
841 gh->gh_owner_pid = get_pid(task_pid(current));
845 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
846 * @gh: the holder structure
850 void gfs2_holder_uninit(struct gfs2_holder *gh)
852 put_pid(gh->gh_owner_pid);
853 gfs2_glock_put(gh->gh_gl);
859 * gfs2_glock_wait - wait on a glock acquisition
860 * @gh: the glock holder
862 * Returns: 0 on success
865 int gfs2_glock_wait(struct gfs2_holder *gh)
867 unsigned long time1 = jiffies;
870 wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
871 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
872 /* Lengthen the minimum hold time. */
873 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
880 * handle_callback - process a demote request
882 * @state: the state the caller wants us to change to
884 * There are only two requests that we are going to see in actual
885 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
888 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
889 unsigned long delay, bool remote)
891 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
893 set_bit(bit, &gl->gl_flags);
894 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
895 gl->gl_demote_state = state;
896 gl->gl_demote_time = jiffies;
897 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
898 gl->gl_demote_state != state) {
899 gl->gl_demote_state = LM_ST_UNLOCKED;
901 if (gl->gl_ops->go_callback)
902 gl->gl_ops->go_callback(gl, remote);
903 trace_gfs2_demote_rq(gl, remote);
906 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
908 struct va_format vaf;
914 seq_vprintf(seq, fmt, args);
926 * add_to_queue - Add a holder to the wait queue (but look for recursion)
927 * @gh: the holder structure to add
929 * Eventually we should move the recursive locking trap to a
930 * debugging option or something like that. This is the fast
931 * path and needs to have the minimum number of distractions.
935 static inline void add_to_queue(struct gfs2_holder *gh)
936 __releases(&gl->gl_spin)
937 __acquires(&gl->gl_spin)
939 struct gfs2_glock *gl = gh->gh_gl;
940 struct gfs2_sbd *sdp = gl->gl_sbd;
941 struct list_head *insert_pt = NULL;
942 struct gfs2_holder *gh2;
945 BUG_ON(gh->gh_owner_pid == NULL);
946 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
949 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
950 if (test_bit(GLF_LOCK, &gl->gl_flags))
951 try_futile = !may_grant(gl, gh);
952 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
956 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
957 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
958 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
961 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
963 gh->gh_error = GLR_TRYFAILED;
964 gfs2_holder_wake(gh);
967 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
969 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
970 insert_pt = &gh2->gh_list;
972 set_bit(GLF_QUEUED, &gl->gl_flags);
973 trace_gfs2_glock_queue(gh, 1);
974 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
975 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
976 if (likely(insert_pt == NULL)) {
977 list_add_tail(&gh->gh_list, &gl->gl_holders);
978 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
982 list_add_tail(&gh->gh_list, insert_pt);
984 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
985 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
986 spin_unlock(&gl->gl_spin);
987 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
988 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
989 spin_lock(&gl->gl_spin);
994 pr_err("original: %pSR\n", (void *)gh2->gh_ip);
995 pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid));
996 pr_err("lock type: %d req lock state : %d\n",
997 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
998 pr_err("new: %pSR\n", (void *)gh->gh_ip);
999 pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid));
1000 pr_err("lock type: %d req lock state : %d\n",
1001 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1002 gfs2_dump_glock(NULL, gl);
1007 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1008 * @gh: the holder structure
1010 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1012 * Returns: 0, GLR_TRYFAILED, or errno on failure
1015 int gfs2_glock_nq(struct gfs2_holder *gh)
1017 struct gfs2_glock *gl = gh->gh_gl;
1018 struct gfs2_sbd *sdp = gl->gl_sbd;
1021 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1024 if (test_bit(GLF_LRU, &gl->gl_flags))
1025 gfs2_glock_remove_from_lru(gl);
1027 spin_lock(&gl->gl_spin);
1029 if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
1030 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
1031 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1032 gl->gl_lockref.count++;
1033 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1034 gl->gl_lockref.count--;
1037 spin_unlock(&gl->gl_spin);
1039 if (!(gh->gh_flags & GL_ASYNC))
1040 error = gfs2_glock_wait(gh);
1046 * gfs2_glock_poll - poll to see if an async request has been completed
1049 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1052 int gfs2_glock_poll(struct gfs2_holder *gh)
1054 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1058 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1059 * @gh: the glock holder
1063 void gfs2_glock_dq(struct gfs2_holder *gh)
1065 struct gfs2_glock *gl = gh->gh_gl;
1066 const struct gfs2_glock_operations *glops = gl->gl_ops;
1070 spin_lock(&gl->gl_spin);
1071 if (gh->gh_flags & GL_NOCACHE)
1072 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1074 list_del_init(&gh->gh_list);
1075 if (find_first_holder(gl) == NULL) {
1076 if (glops->go_unlock) {
1077 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1078 spin_unlock(&gl->gl_spin);
1079 glops->go_unlock(gh);
1080 spin_lock(&gl->gl_spin);
1081 clear_bit(GLF_LOCK, &gl->gl_flags);
1083 if (list_empty(&gl->gl_holders) &&
1084 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1085 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1088 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
1089 gfs2_glock_add_to_lru(gl);
1091 trace_gfs2_glock_queue(gh, 0);
1092 spin_unlock(&gl->gl_spin);
1093 if (likely(fast_path))
1096 gfs2_glock_hold(gl);
1097 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1098 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1099 gl->gl_name.ln_type == LM_TYPE_INODE)
1100 delay = gl->gl_hold_time;
1101 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1105 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1107 struct gfs2_glock *gl = gh->gh_gl;
1110 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
1114 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1115 * @gh: the holder structure
1119 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1122 gfs2_holder_uninit(gh);
1126 * gfs2_glock_nq_num - acquire a glock based on lock number
1127 * @sdp: the filesystem
1128 * @number: the lock number
1129 * @glops: the glock operations for the type of glock
1130 * @state: the state to acquire the glock in
1131 * @flags: modifier flags for the acquisition
1132 * @gh: the struct gfs2_holder
1137 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1138 const struct gfs2_glock_operations *glops,
1139 unsigned int state, int flags, struct gfs2_holder *gh)
1141 struct gfs2_glock *gl;
1144 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1146 error = gfs2_glock_nq_init(gl, state, flags, gh);
1154 * glock_compare - Compare two struct gfs2_glock structures for sorting
1155 * @arg_a: the first structure
1156 * @arg_b: the second structure
1160 static int glock_compare(const void *arg_a, const void *arg_b)
1162 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1163 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1164 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1165 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1167 if (a->ln_number > b->ln_number)
1169 if (a->ln_number < b->ln_number)
1171 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1176 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1177 * @num_gh: the number of structures
1178 * @ghs: an array of struct gfs2_holder structures
1180 * Returns: 0 on success (all glocks acquired),
1181 * errno on failure (no glocks acquired)
1184 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1185 struct gfs2_holder **p)
1190 for (x = 0; x < num_gh; x++)
1193 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1195 for (x = 0; x < num_gh; x++) {
1196 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1198 error = gfs2_glock_nq(p[x]);
1201 gfs2_glock_dq(p[x]);
1210 * gfs2_glock_nq_m - acquire multiple glocks
1211 * @num_gh: the number of structures
1212 * @ghs: an array of struct gfs2_holder structures
1215 * Returns: 0 on success (all glocks acquired),
1216 * errno on failure (no glocks acquired)
1219 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1221 struct gfs2_holder *tmp[4];
1222 struct gfs2_holder **pph = tmp;
1229 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1230 return gfs2_glock_nq(ghs);
1234 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1239 error = nq_m_sync(num_gh, ghs, pph);
1248 * gfs2_glock_dq_m - release multiple glocks
1249 * @num_gh: the number of structures
1250 * @ghs: an array of struct gfs2_holder structures
1254 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1257 gfs2_glock_dq(&ghs[num_gh]);
1260 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1262 unsigned long delay = 0;
1263 unsigned long holdtime;
1264 unsigned long now = jiffies;
1266 gfs2_glock_hold(gl);
1267 holdtime = gl->gl_tchange + gl->gl_hold_time;
1268 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1269 gl->gl_name.ln_type == LM_TYPE_INODE) {
1270 if (time_before(now, holdtime))
1271 delay = holdtime - now;
1272 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1273 delay = gl->gl_hold_time;
1276 spin_lock(&gl->gl_spin);
1277 handle_callback(gl, state, delay, true);
1278 spin_unlock(&gl->gl_spin);
1279 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1284 * gfs2_should_freeze - Figure out if glock should be frozen
1285 * @gl: The glock in question
1287 * Glocks are not frozen if (a) the result of the dlm operation is
1288 * an error, (b) the locking operation was an unlock operation or
1289 * (c) if there is a "noexp" flagged request anywhere in the queue
1291 * Returns: 1 if freezing should occur, 0 otherwise
1294 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1296 const struct gfs2_holder *gh;
1298 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1300 if (gl->gl_target == LM_ST_UNLOCKED)
1303 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1304 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1306 if (LM_FLAG_NOEXP & gh->gh_flags)
1314 * gfs2_glock_complete - Callback used by locking
1315 * @gl: Pointer to the glock
1316 * @ret: The return value from the dlm
1318 * The gl_reply field is under the gl_spin lock so that it is ok
1319 * to use a bitfield shared with other glock state fields.
1322 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1324 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1326 spin_lock(&gl->gl_spin);
1329 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1330 if (gfs2_should_freeze(gl)) {
1331 set_bit(GLF_FROZEN, &gl->gl_flags);
1332 spin_unlock(&gl->gl_spin);
1337 gl->gl_lockref.count++;
1338 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1339 spin_unlock(&gl->gl_spin);
1341 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1345 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1347 struct gfs2_glock *gla, *glb;
1349 gla = list_entry(a, struct gfs2_glock, gl_lru);
1350 glb = list_entry(b, struct gfs2_glock, gl_lru);
1352 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1354 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1361 * gfs2_dispose_glock_lru - Demote a list of glocks
1362 * @list: The list to dispose of
1364 * Disposing of glocks may involve disk accesses, so that here we sort
1365 * the glocks by number (i.e. disk location of the inodes) so that if
1366 * there are any such accesses, they'll be sent in order (mostly).
1368 * Must be called under the lru_lock, but may drop and retake this
1369 * lock. While the lru_lock is dropped, entries may vanish from the
1370 * list, but no new entries will appear on the list (since it is
1374 static void gfs2_dispose_glock_lru(struct list_head *list)
1375 __releases(&lru_lock)
1376 __acquires(&lru_lock)
1378 struct gfs2_glock *gl;
1380 list_sort(NULL, list, glock_cmp);
1382 while(!list_empty(list)) {
1383 gl = list_entry(list->next, struct gfs2_glock, gl_lru);
1384 list_del_init(&gl->gl_lru);
1385 if (!spin_trylock(&gl->gl_spin)) {
1387 list_add(&gl->gl_lru, &lru_list);
1388 atomic_inc(&lru_count);
1391 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1392 spin_unlock(&gl->gl_spin);
1393 goto add_back_to_lru;
1395 clear_bit(GLF_LRU, &gl->gl_flags);
1396 gl->gl_lockref.count++;
1398 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1399 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1400 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1401 gl->gl_lockref.count--;
1402 spin_unlock(&gl->gl_spin);
1403 cond_resched_lock(&lru_lock);
1408 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1409 * @nr: The number of entries to scan
1411 * This function selects the entries on the LRU which are able to
1412 * be demoted, and then kicks off the process by calling
1413 * gfs2_dispose_glock_lru() above.
1416 static long gfs2_scan_glock_lru(int nr)
1418 struct gfs2_glock *gl;
1423 spin_lock(&lru_lock);
1424 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1425 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1427 /* Test for being demotable */
1428 if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
1429 list_move(&gl->gl_lru, &dispose);
1430 atomic_dec(&lru_count);
1435 list_move(&gl->gl_lru, &skipped);
1437 list_splice(&skipped, &lru_list);
1438 if (!list_empty(&dispose))
1439 gfs2_dispose_glock_lru(&dispose);
1440 spin_unlock(&lru_lock);
1445 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1446 struct shrink_control *sc)
1448 if (!(sc->gfp_mask & __GFP_FS))
1450 return gfs2_scan_glock_lru(sc->nr_to_scan);
1453 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1454 struct shrink_control *sc)
1456 return vfs_pressure_ratio(atomic_read(&lru_count));
1459 static struct shrinker glock_shrinker = {
1460 .seeks = DEFAULT_SEEKS,
1461 .count_objects = gfs2_glock_shrink_count,
1462 .scan_objects = gfs2_glock_shrink_scan,
1466 * examine_bucket - Call a function for glock in a hash bucket
1467 * @examiner: the function
1468 * @sdp: the filesystem
1469 * @bucket: the bucket
1473 static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
1476 struct gfs2_glock *gl;
1477 struct hlist_bl_head *head = &gl_hash_table[hash];
1478 struct hlist_bl_node *pos;
1481 hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
1482 if ((gl->gl_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref))
1489 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1493 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1494 examine_bucket(examiner, sdp, x);
1499 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1500 * @gl: The glock to thaw
1504 static void thaw_glock(struct gfs2_glock *gl)
1506 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1508 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1509 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
1516 * clear_glock - look at a glock and see if we can free it from glock cache
1517 * @gl: the glock to look at
1521 static void clear_glock(struct gfs2_glock *gl)
1523 gfs2_glock_remove_from_lru(gl);
1525 spin_lock(&gl->gl_spin);
1526 if (gl->gl_state != LM_ST_UNLOCKED)
1527 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1528 spin_unlock(&gl->gl_spin);
1529 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1534 * gfs2_glock_thaw - Thaw any frozen glocks
1535 * @sdp: The super block
1539 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1541 glock_hash_walk(thaw_glock, sdp);
1544 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1546 spin_lock(&gl->gl_spin);
1547 gfs2_dump_glock(seq, gl);
1548 spin_unlock(&gl->gl_spin);
1551 static void dump_glock_func(struct gfs2_glock *gl)
1553 dump_glock(NULL, gl);
1557 * gfs2_gl_hash_clear - Empty out the glock hash table
1558 * @sdp: the filesystem
1559 * @wait: wait until it's all gone
1561 * Called when unmounting the filesystem.
1564 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1566 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1567 flush_workqueue(glock_workqueue);
1568 glock_hash_walk(clear_glock, sdp);
1569 flush_workqueue(glock_workqueue);
1570 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1571 glock_hash_walk(dump_glock_func, sdp);
1574 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1576 struct gfs2_glock *gl = ip->i_gl;
1579 ret = gfs2_truncatei_resume(ip);
1580 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1582 spin_lock(&gl->gl_spin);
1583 clear_bit(GLF_LOCK, &gl->gl_flags);
1585 spin_unlock(&gl->gl_spin);
1588 static const char *state2str(unsigned state)
1591 case LM_ST_UNLOCKED:
1595 case LM_ST_DEFERRED:
1597 case LM_ST_EXCLUSIVE:
1603 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1606 if (flags & LM_FLAG_TRY)
1608 if (flags & LM_FLAG_TRY_1CB)
1610 if (flags & LM_FLAG_NOEXP)
1612 if (flags & LM_FLAG_ANY)
1614 if (flags & LM_FLAG_PRIORITY)
1616 if (flags & GL_ASYNC)
1618 if (flags & GL_EXACT)
1620 if (flags & GL_NOCACHE)
1622 if (test_bit(HIF_HOLDER, &iflags))
1624 if (test_bit(HIF_WAIT, &iflags))
1626 if (test_bit(HIF_FIRST, &iflags))
1633 * dump_holder - print information about a glock holder
1634 * @seq: the seq_file struct
1635 * @gh: the glock holder
1639 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1641 struct task_struct *gh_owner = NULL;
1645 if (gh->gh_owner_pid)
1646 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1647 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1648 state2str(gh->gh_state),
1649 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1651 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1652 gh_owner ? gh_owner->comm : "(ended)",
1657 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1659 const unsigned long *gflags = &gl->gl_flags;
1662 if (test_bit(GLF_LOCK, gflags))
1664 if (test_bit(GLF_DEMOTE, gflags))
1666 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1668 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1670 if (test_bit(GLF_DIRTY, gflags))
1672 if (test_bit(GLF_LFLUSH, gflags))
1674 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1676 if (test_bit(GLF_REPLY_PENDING, gflags))
1678 if (test_bit(GLF_INITIAL, gflags))
1680 if (test_bit(GLF_FROZEN, gflags))
1682 if (test_bit(GLF_QUEUED, gflags))
1684 if (test_bit(GLF_LRU, gflags))
1688 if (test_bit(GLF_BLOCKING, gflags))
1695 * gfs2_dump_glock - print information about a glock
1696 * @seq: The seq_file struct
1699 * The file format is as follows:
1700 * One line per object, capital letters are used to indicate objects
1701 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1702 * other objects are indented by a single space and follow the glock to
1703 * which they are related. Fields are indicated by lower case letters
1704 * followed by a colon and the field value, except for strings which are in
1705 * [] so that its possible to see if they are composed of spaces for
1706 * example. The field's are n = number (id of the object), f = flags,
1707 * t = type, s = state, r = refcount, e = error, p = pid.
1711 void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1713 const struct gfs2_glock_operations *glops = gl->gl_ops;
1714 unsigned long long dtime;
1715 const struct gfs2_holder *gh;
1716 char gflags_buf[32];
1718 dtime = jiffies - gl->gl_demote_time;
1719 dtime *= 1000000/HZ; /* demote time in uSec */
1720 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1722 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",
1723 state2str(gl->gl_state),
1724 gl->gl_name.ln_type,
1725 (unsigned long long)gl->gl_name.ln_number,
1726 gflags2str(gflags_buf, gl),
1727 state2str(gl->gl_target),
1728 state2str(gl->gl_demote_state), dtime,
1729 atomic_read(&gl->gl_ail_count),
1730 atomic_read(&gl->gl_revokes),
1731 (int)gl->gl_lockref.count, gl->gl_hold_time);
1733 list_for_each_entry(gh, &gl->gl_holders, gh_list)
1734 dump_holder(seq, gh);
1736 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1737 glops->go_dump(seq, gl);
1740 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1742 struct gfs2_glock *gl = iter_ptr;
1744 seq_printf(seq, "G: n:%u/%llx rtt:%lld/%lld rttb:%lld/%lld irt:%lld/%lld dcnt: %lld qcnt: %lld\n",
1745 gl->gl_name.ln_type,
1746 (unsigned long long)gl->gl_name.ln_number,
1747 (long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1748 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1749 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1750 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1751 (long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1752 (long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1753 (long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1754 (long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1758 static const char *gfs2_gltype[] = {
1772 static const char *gfs2_stype[] = {
1773 [GFS2_LKS_SRTT] = "srtt",
1774 [GFS2_LKS_SRTTVAR] = "srttvar",
1775 [GFS2_LKS_SRTTB] = "srttb",
1776 [GFS2_LKS_SRTTVARB] = "srttvarb",
1777 [GFS2_LKS_SIRT] = "sirt",
1778 [GFS2_LKS_SIRTVAR] = "sirtvar",
1779 [GFS2_LKS_DCOUNT] = "dlm",
1780 [GFS2_LKS_QCOUNT] = "queue",
1783 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1785 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1787 struct gfs2_glock_iter *gi = seq->private;
1788 struct gfs2_sbd *sdp = gi->sdp;
1789 unsigned index = gi->hash >> 3;
1790 unsigned subindex = gi->hash & 0x07;
1794 if (index == 0 && subindex != 0)
1797 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1798 (index == 0) ? "cpu": gfs2_stype[subindex]);
1800 for_each_possible_cpu(i) {
1801 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1805 value = lkstats->lkstats[index - 1].stats[subindex];
1807 seq_printf(seq, " %15lld", (long long)value);
1809 seq_putc(seq, '\n');
1813 int __init gfs2_glock_init(void)
1816 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1817 INIT_HLIST_BL_HEAD(&gl_hash_table[i]);
1820 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1821 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1822 if (!glock_workqueue)
1824 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1825 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1827 if (!gfs2_delete_workqueue) {
1828 destroy_workqueue(glock_workqueue);
1832 register_shrinker(&glock_shrinker);
1837 void gfs2_glock_exit(void)
1839 unregister_shrinker(&glock_shrinker);
1840 destroy_workqueue(glock_workqueue);
1841 destroy_workqueue(gfs2_delete_workqueue);
1844 static inline struct gfs2_glock *glock_hash_chain(unsigned hash)
1846 return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]),
1847 struct gfs2_glock, gl_list);
1850 static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl)
1852 return hlist_bl_entry(rcu_dereference(gl->gl_list.next),
1853 struct gfs2_glock, gl_list);
1856 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1858 struct gfs2_glock *gl;
1863 gi->gl = glock_hash_next(gl);
1866 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1870 gi->gl = glock_hash_chain(gi->hash);
1873 while (gi->gl == NULL) {
1875 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1879 gi->gl = glock_hash_chain(gi->hash);
1882 /* Skip entries for other sb and dead entries */
1883 } while (gi->sdp != gi->gl->gl_sbd ||
1884 __lockref_is_dead(&gi->gl->gl_lockref));
1889 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1891 struct gfs2_glock_iter *gi = seq->private;
1894 if (gi->last_pos <= *pos)
1895 n = gi->nhash + (*pos - gi->last_pos);
1903 if (gfs2_glock_iter_next(gi))
1907 gi->last_pos = *pos;
1911 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1914 struct gfs2_glock_iter *gi = seq->private;
1917 gi->last_pos = *pos;
1918 if (gfs2_glock_iter_next(gi))
1924 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1926 struct gfs2_glock_iter *gi = seq->private;
1933 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1935 dump_glock(seq, iter_ptr);
1939 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1941 struct gfs2_glock_iter *gi = seq->private;
1944 if (*pos >= GFS2_NR_SBSTATS)
1947 return SEQ_START_TOKEN;
1950 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1953 struct gfs2_glock_iter *gi = seq->private;
1956 if (gi->hash >= GFS2_NR_SBSTATS) {
1960 return SEQ_START_TOKEN;
1963 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1968 static const struct seq_operations gfs2_glock_seq_ops = {
1969 .start = gfs2_glock_seq_start,
1970 .next = gfs2_glock_seq_next,
1971 .stop = gfs2_glock_seq_stop,
1972 .show = gfs2_glock_seq_show,
1975 static const struct seq_operations gfs2_glstats_seq_ops = {
1976 .start = gfs2_glock_seq_start,
1977 .next = gfs2_glock_seq_next,
1978 .stop = gfs2_glock_seq_stop,
1979 .show = gfs2_glstats_seq_show,
1982 static const struct seq_operations gfs2_sbstats_seq_ops = {
1983 .start = gfs2_sbstats_seq_start,
1984 .next = gfs2_sbstats_seq_next,
1985 .stop = gfs2_sbstats_seq_stop,
1986 .show = gfs2_sbstats_seq_show,
1989 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
1991 static int gfs2_glocks_open(struct inode *inode, struct file *file)
1993 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1994 sizeof(struct gfs2_glock_iter));
1996 struct seq_file *seq = file->private_data;
1997 struct gfs2_glock_iter *gi = seq->private;
1998 gi->sdp = inode->i_private;
1999 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2001 seq->size = GFS2_SEQ_GOODSIZE;
2006 static int gfs2_glstats_open(struct inode *inode, struct file *file)
2008 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
2009 sizeof(struct gfs2_glock_iter));
2011 struct seq_file *seq = file->private_data;
2012 struct gfs2_glock_iter *gi = seq->private;
2013 gi->sdp = inode->i_private;
2014 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2016 seq->size = GFS2_SEQ_GOODSIZE;
2021 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
2023 int ret = seq_open_private(file, &gfs2_sbstats_seq_ops,
2024 sizeof(struct gfs2_glock_iter));
2026 struct seq_file *seq = file->private_data;
2027 struct gfs2_glock_iter *gi = seq->private;
2028 gi->sdp = inode->i_private;
2033 static const struct file_operations gfs2_glocks_fops = {
2034 .owner = THIS_MODULE,
2035 .open = gfs2_glocks_open,
2037 .llseek = seq_lseek,
2038 .release = seq_release_private,
2041 static const struct file_operations gfs2_glstats_fops = {
2042 .owner = THIS_MODULE,
2043 .open = gfs2_glstats_open,
2045 .llseek = seq_lseek,
2046 .release = seq_release_private,
2049 static const struct file_operations gfs2_sbstats_fops = {
2050 .owner = THIS_MODULE,
2051 .open = gfs2_sbstats_open,
2053 .llseek = seq_lseek,
2054 .release = seq_release_private,
2057 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
2059 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
2060 if (!sdp->debugfs_dir)
2062 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
2064 sdp->debugfs_dir, sdp,
2066 if (!sdp->debugfs_dentry_glocks)
2069 sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
2071 sdp->debugfs_dir, sdp,
2072 &gfs2_glstats_fops);
2073 if (!sdp->debugfs_dentry_glstats)
2076 sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
2078 sdp->debugfs_dir, sdp,
2079 &gfs2_sbstats_fops);
2080 if (!sdp->debugfs_dentry_sbstats)
2085 gfs2_delete_debugfs_file(sdp);
2089 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2091 if (sdp->debugfs_dir) {
2092 if (sdp->debugfs_dentry_glocks) {
2093 debugfs_remove(sdp->debugfs_dentry_glocks);
2094 sdp->debugfs_dentry_glocks = NULL;
2096 if (sdp->debugfs_dentry_glstats) {
2097 debugfs_remove(sdp->debugfs_dentry_glstats);
2098 sdp->debugfs_dentry_glstats = NULL;
2100 if (sdp->debugfs_dentry_sbstats) {
2101 debugfs_remove(sdp->debugfs_dentry_sbstats);
2102 sdp->debugfs_dentry_sbstats = NULL;
2104 debugfs_remove(sdp->debugfs_dir);
2105 sdp->debugfs_dir = NULL;
2109 int gfs2_register_debugfs(void)
2111 gfs2_root = debugfs_create_dir("gfs2", NULL);
2112 return gfs2_root ? 0 : -ENOMEM;
2115 void gfs2_unregister_debugfs(void)
2117 debugfs_remove(gfs2_root);