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>
37 #include <linux/rhashtable.h>
50 #define CREATE_TRACE_POINTS
51 #include "trace_gfs2.h"
53 struct gfs2_glock_iter {
54 struct gfs2_sbd *sdp; /* incore superblock */
55 struct rhashtable_iter hti; /* rhashtable iterator */
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)
74 static struct rhashtable_params ht_parms = {
75 .nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4,
76 .key_len = sizeof(struct lm_lockname),
77 .key_offset = offsetof(struct gfs2_glock, gl_name),
78 .head_offset = offsetof(struct gfs2_glock, gl_node),
81 static struct rhashtable gl_hash_table;
83 static void gfs2_glock_dealloc(struct rcu_head *rcu)
85 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
87 if (gl->gl_ops->go_flags & GLOF_ASPACE) {
88 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
90 kfree(gl->gl_lksb.sb_lvbptr);
91 kmem_cache_free(gfs2_glock_cachep, gl);
95 void gfs2_glock_free(struct gfs2_glock *gl)
97 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
99 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
100 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
101 wake_up(&sdp->sd_glock_wait);
105 * gfs2_glock_hold() - increment reference count on glock
106 * @gl: The glock to hold
110 static void gfs2_glock_hold(struct gfs2_glock *gl)
112 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
113 lockref_get(&gl->gl_lockref);
117 * demote_ok - Check to see if it's ok to unlock a glock
120 * Returns: 1 if it's ok
123 static int demote_ok(const struct gfs2_glock *gl)
125 const struct gfs2_glock_operations *glops = gl->gl_ops;
127 if (gl->gl_state == LM_ST_UNLOCKED)
129 if (!list_empty(&gl->gl_holders))
131 if (glops->go_demote_ok)
132 return glops->go_demote_ok(gl);
137 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
139 if (!(gl->gl_ops->go_flags & GLOF_LRU))
142 spin_lock(&lru_lock);
144 list_del(&gl->gl_lru);
145 list_add_tail(&gl->gl_lru, &lru_list);
147 if (!test_bit(GLF_LRU, &gl->gl_flags)) {
148 set_bit(GLF_LRU, &gl->gl_flags);
149 atomic_inc(&lru_count);
152 spin_unlock(&lru_lock);
155 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
157 spin_lock(&lru_lock);
158 if (test_bit(GLF_LRU, &gl->gl_flags)) {
159 list_del_init(&gl->gl_lru);
160 atomic_dec(&lru_count);
161 clear_bit(GLF_LRU, &gl->gl_flags);
163 spin_unlock(&lru_lock);
167 * gfs2_glock_put() - Decrement reference count on glock
168 * @gl: The glock to put
172 void gfs2_glock_put(struct gfs2_glock *gl)
174 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
175 struct address_space *mapping = gfs2_glock2aspace(gl);
177 if (lockref_put_or_lock(&gl->gl_lockref))
180 lockref_mark_dead(&gl->gl_lockref);
182 gfs2_glock_remove_from_lru(gl);
183 spin_unlock(&gl->gl_lockref.lock);
184 rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms);
185 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
186 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
187 trace_gfs2_glock_put(gl);
188 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
192 * may_grant - check if its ok to grant a new lock
194 * @gh: The lock request which we wish to grant
196 * Returns: true if its ok to grant the lock
199 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
201 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
202 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
203 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
205 if (gl->gl_state == gh->gh_state)
207 if (gh->gh_flags & GL_EXACT)
209 if (gl->gl_state == LM_ST_EXCLUSIVE) {
210 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
212 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
215 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
220 static void gfs2_holder_wake(struct gfs2_holder *gh)
222 clear_bit(HIF_WAIT, &gh->gh_iflags);
223 smp_mb__after_atomic();
224 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
228 * do_error - Something unexpected has happened during a lock request
232 static inline void do_error(struct gfs2_glock *gl, const int ret)
234 struct gfs2_holder *gh, *tmp;
236 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
237 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
239 if (ret & LM_OUT_ERROR)
241 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
242 gh->gh_error = GLR_TRYFAILED;
245 list_del_init(&gh->gh_list);
246 trace_gfs2_glock_queue(gh, 0);
247 gfs2_holder_wake(gh);
252 * do_promote - promote as many requests as possible on the current queue
255 * Returns: 1 if there is a blocked holder at the head of the list, or 2
256 * if a type specific operation is underway.
259 static int do_promote(struct gfs2_glock *gl)
260 __releases(&gl->gl_lockref.lock)
261 __acquires(&gl->gl_lockref.lock)
263 const struct gfs2_glock_operations *glops = gl->gl_ops;
264 struct gfs2_holder *gh, *tmp;
268 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
269 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
271 if (may_grant(gl, gh)) {
272 if (gh->gh_list.prev == &gl->gl_holders &&
274 spin_unlock(&gl->gl_lockref.lock);
275 /* FIXME: eliminate this eventually */
276 ret = glops->go_lock(gh);
277 spin_lock(&gl->gl_lockref.lock);
282 list_del_init(&gh->gh_list);
283 trace_gfs2_glock_queue(gh, 0);
284 gfs2_holder_wake(gh);
287 set_bit(HIF_HOLDER, &gh->gh_iflags);
288 trace_gfs2_promote(gh, 1);
289 gfs2_holder_wake(gh);
292 set_bit(HIF_HOLDER, &gh->gh_iflags);
293 trace_gfs2_promote(gh, 0);
294 gfs2_holder_wake(gh);
297 if (gh->gh_list.prev == &gl->gl_holders)
306 * find_first_waiter - find the first gh that's waiting for the glock
310 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
312 struct gfs2_holder *gh;
314 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
315 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
322 * state_change - record that the glock is now in a different state
324 * @new_state the new state
328 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
332 held1 = (gl->gl_state != LM_ST_UNLOCKED);
333 held2 = (new_state != LM_ST_UNLOCKED);
335 if (held1 != held2) {
336 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
338 gl->gl_lockref.count++;
340 gl->gl_lockref.count--;
342 if (held1 && held2 && list_empty(&gl->gl_holders))
343 clear_bit(GLF_QUEUED, &gl->gl_flags);
345 if (new_state != gl->gl_target)
346 /* shorten our minimum hold time */
347 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
349 gl->gl_state = new_state;
350 gl->gl_tchange = jiffies;
353 static void gfs2_demote_wake(struct gfs2_glock *gl)
355 gl->gl_demote_state = LM_ST_EXCLUSIVE;
356 clear_bit(GLF_DEMOTE, &gl->gl_flags);
357 smp_mb__after_atomic();
358 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
362 * finish_xmote - The DLM has replied to one of our lock requests
364 * @ret: The status from the DLM
368 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
370 const struct gfs2_glock_operations *glops = gl->gl_ops;
371 struct gfs2_holder *gh;
372 unsigned state = ret & LM_OUT_ST_MASK;
375 spin_lock(&gl->gl_lockref.lock);
376 trace_gfs2_glock_state_change(gl, state);
377 state_change(gl, state);
378 gh = find_first_waiter(gl);
380 /* Demote to UN request arrived during demote to SH or DF */
381 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
382 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
383 gl->gl_target = LM_ST_UNLOCKED;
385 /* Check for state != intended state */
386 if (unlikely(state != gl->gl_target)) {
387 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
388 /* move to back of queue and try next entry */
389 if (ret & LM_OUT_CANCELED) {
390 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
391 list_move_tail(&gh->gh_list, &gl->gl_holders);
392 gh = find_first_waiter(gl);
393 gl->gl_target = gh->gh_state;
396 /* Some error or failed "try lock" - report it */
397 if ((ret & LM_OUT_ERROR) ||
398 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
399 gl->gl_target = gl->gl_state;
405 /* Unlocked due to conversion deadlock, try again */
408 do_xmote(gl, gh, gl->gl_target);
410 /* Conversion fails, unlock and try again */
413 do_xmote(gl, gh, LM_ST_UNLOCKED);
415 default: /* Everything else */
416 pr_err("wanted %u got %u\n", gl->gl_target, state);
419 spin_unlock(&gl->gl_lockref.lock);
423 /* Fast path - we got what we asked for */
424 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
425 gfs2_demote_wake(gl);
426 if (state != LM_ST_UNLOCKED) {
427 if (glops->go_xmote_bh) {
428 spin_unlock(&gl->gl_lockref.lock);
429 rv = glops->go_xmote_bh(gl, gh);
430 spin_lock(&gl->gl_lockref.lock);
441 clear_bit(GLF_LOCK, &gl->gl_flags);
443 spin_unlock(&gl->gl_lockref.lock);
447 * do_xmote - Calls the DLM to change the state of a lock
448 * @gl: The lock state
449 * @gh: The holder (only for promotes)
450 * @target: The target lock state
454 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
455 __releases(&gl->gl_lockref.lock)
456 __acquires(&gl->gl_lockref.lock)
458 const struct gfs2_glock_operations *glops = gl->gl_ops;
459 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
460 unsigned int lck_flags = gh ? gh->gh_flags : 0;
463 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
465 GLOCK_BUG_ON(gl, gl->gl_state == target);
466 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
467 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
469 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
470 do_error(gl, 0); /* Fail queued try locks */
473 set_bit(GLF_BLOCKING, &gl->gl_flags);
474 if ((gl->gl_req == LM_ST_UNLOCKED) ||
475 (gl->gl_state == LM_ST_EXCLUSIVE) ||
476 (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
477 clear_bit(GLF_BLOCKING, &gl->gl_flags);
478 spin_unlock(&gl->gl_lockref.lock);
481 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
482 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
483 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
486 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
488 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
490 pr_err("lm_lock ret %d\n", ret);
493 } else { /* lock_nolock */
494 finish_xmote(gl, target);
495 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
499 spin_lock(&gl->gl_lockref.lock);
503 * find_first_holder - find the first "holder" gh
507 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
509 struct gfs2_holder *gh;
511 if (!list_empty(&gl->gl_holders)) {
512 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
513 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
520 * run_queue - do all outstanding tasks related to a glock
521 * @gl: The glock in question
522 * @nonblock: True if we must not block in run_queue
526 static void run_queue(struct gfs2_glock *gl, const int nonblock)
527 __releases(&gl->gl_lockref.lock)
528 __acquires(&gl->gl_lockref.lock)
530 struct gfs2_holder *gh = NULL;
533 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
536 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
538 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
539 gl->gl_demote_state != gl->gl_state) {
540 if (find_first_holder(gl))
544 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
545 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
546 gl->gl_target = gl->gl_demote_state;
548 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
549 gfs2_demote_wake(gl);
550 ret = do_promote(gl);
555 gh = find_first_waiter(gl);
556 gl->gl_target = gh->gh_state;
557 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
558 do_error(gl, 0); /* Fail queued try locks */
560 do_xmote(gl, gh, gl->gl_target);
565 clear_bit(GLF_LOCK, &gl->gl_flags);
566 smp_mb__after_atomic();
567 gl->gl_lockref.count++;
568 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
569 gl->gl_lockref.count--;
573 clear_bit(GLF_LOCK, &gl->gl_flags);
574 smp_mb__after_atomic();
578 static void delete_work_func(struct work_struct *work)
580 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
581 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
582 struct gfs2_inode *ip;
584 u64 no_addr = gl->gl_name.ln_number;
587 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
590 inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
592 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
593 if (inode && !IS_ERR(inode)) {
594 d_prune_aliases(inode);
600 static void glock_work_func(struct work_struct *work)
602 unsigned long delay = 0;
603 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
606 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
607 finish_xmote(gl, gl->gl_reply);
610 spin_lock(&gl->gl_lockref.lock);
611 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
612 gl->gl_state != LM_ST_UNLOCKED &&
613 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
614 unsigned long holdtime, now = jiffies;
616 holdtime = gl->gl_tchange + gl->gl_hold_time;
617 if (time_before(now, holdtime))
618 delay = holdtime - now;
621 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
622 set_bit(GLF_DEMOTE, &gl->gl_flags);
626 spin_unlock(&gl->gl_lockref.lock);
630 if (gl->gl_name.ln_type != LM_TYPE_INODE)
632 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
640 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
641 * @sdp: The GFS2 superblock
642 * @number: the lock number
643 * @glops: The glock_operations to use
644 * @create: If 0, don't create the glock if it doesn't exist
645 * @glp: the glock is returned here
647 * This does not lock a glock, just finds/creates structures for one.
652 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
653 const struct gfs2_glock_operations *glops, int create,
654 struct gfs2_glock **glp)
656 struct super_block *s = sdp->sd_vfs;
657 struct lm_lockname name = { .ln_number = number,
658 .ln_type = glops->go_type,
660 struct gfs2_glock *gl, *tmp = NULL;
661 struct address_space *mapping;
662 struct kmem_cache *cachep;
666 gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
667 if (gl && !lockref_get_not_dead(&gl->gl_lockref))
677 if (glops->go_flags & GLOF_ASPACE)
678 cachep = gfs2_glock_aspace_cachep;
680 cachep = gfs2_glock_cachep;
681 gl = kmem_cache_alloc(cachep, GFP_NOFS);
685 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
687 if (glops->go_flags & GLOF_LVB) {
688 gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_NOFS);
689 if (!gl->gl_lksb.sb_lvbptr) {
690 kmem_cache_free(cachep, gl);
695 atomic_inc(&sdp->sd_glock_disposal);
696 gl->gl_node.next = NULL;
699 gl->gl_lockref.count = 1;
700 gl->gl_state = LM_ST_UNLOCKED;
701 gl->gl_target = LM_ST_UNLOCKED;
702 gl->gl_demote_state = LM_ST_EXCLUSIVE;
704 gl->gl_dstamp = ktime_set(0, 0);
706 /* We use the global stats to estimate the initial per-glock stats */
707 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
709 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
710 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
711 gl->gl_tchange = jiffies;
712 gl->gl_object = NULL;
713 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
714 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
715 INIT_WORK(&gl->gl_delete, delete_work_func);
717 mapping = gfs2_glock2aspace(gl);
719 mapping->a_ops = &gfs2_meta_aops;
720 mapping->host = s->s_bdev->bd_inode;
722 mapping_set_gfp_mask(mapping, GFP_NOFS);
723 mapping->private_data = NULL;
724 mapping->writeback_index = 0;
728 ret = rhashtable_lookup_insert_fast(&gl_hash_table, &gl->gl_node,
735 if (ret == -EEXIST) {
738 tmp = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
739 if (tmp == NULL || !lockref_get_not_dead(&tmp->gl_lockref)) {
752 kfree(gl->gl_lksb.sb_lvbptr);
753 kmem_cache_free(cachep, gl);
754 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
755 wake_up(&sdp->sd_glock_wait);
762 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
764 * @state: the state we're requesting
765 * @flags: the modifier flags
766 * @gh: the holder structure
770 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
771 struct gfs2_holder *gh)
773 INIT_LIST_HEAD(&gh->gh_list);
775 gh->gh_ip = _RET_IP_;
776 gh->gh_owner_pid = get_pid(task_pid(current));
777 gh->gh_state = state;
778 gh->gh_flags = flags;
785 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
786 * @state: the state we're requesting
787 * @flags: the modifier flags
788 * @gh: the holder structure
790 * Don't mess with the glock.
794 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
796 gh->gh_state = state;
797 gh->gh_flags = flags;
799 gh->gh_ip = _RET_IP_;
800 put_pid(gh->gh_owner_pid);
801 gh->gh_owner_pid = get_pid(task_pid(current));
805 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
806 * @gh: the holder structure
810 void gfs2_holder_uninit(struct gfs2_holder *gh)
812 put_pid(gh->gh_owner_pid);
813 gfs2_glock_put(gh->gh_gl);
819 * gfs2_glock_wait - wait on a glock acquisition
820 * @gh: the glock holder
822 * Returns: 0 on success
825 int gfs2_glock_wait(struct gfs2_holder *gh)
827 unsigned long time1 = jiffies;
830 wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
831 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
832 /* Lengthen the minimum hold time. */
833 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
840 * handle_callback - process a demote request
842 * @state: the state the caller wants us to change to
844 * There are only two requests that we are going to see in actual
845 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
848 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
849 unsigned long delay, bool remote)
851 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
853 set_bit(bit, &gl->gl_flags);
854 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
855 gl->gl_demote_state = state;
856 gl->gl_demote_time = jiffies;
857 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
858 gl->gl_demote_state != state) {
859 gl->gl_demote_state = LM_ST_UNLOCKED;
861 if (gl->gl_ops->go_callback)
862 gl->gl_ops->go_callback(gl, remote);
863 trace_gfs2_demote_rq(gl, remote);
866 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
868 struct va_format vaf;
874 seq_vprintf(seq, fmt, args);
886 * add_to_queue - Add a holder to the wait queue (but look for recursion)
887 * @gh: the holder structure to add
889 * Eventually we should move the recursive locking trap to a
890 * debugging option or something like that. This is the fast
891 * path and needs to have the minimum number of distractions.
895 static inline void add_to_queue(struct gfs2_holder *gh)
896 __releases(&gl->gl_lockref.lock)
897 __acquires(&gl->gl_lockref.lock)
899 struct gfs2_glock *gl = gh->gh_gl;
900 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
901 struct list_head *insert_pt = NULL;
902 struct gfs2_holder *gh2;
905 BUG_ON(gh->gh_owner_pid == NULL);
906 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
909 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
910 if (test_bit(GLF_LOCK, &gl->gl_flags))
911 try_futile = !may_grant(gl, gh);
912 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
916 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
917 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
918 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
921 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
923 gh->gh_error = GLR_TRYFAILED;
924 gfs2_holder_wake(gh);
927 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
929 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
930 insert_pt = &gh2->gh_list;
932 set_bit(GLF_QUEUED, &gl->gl_flags);
933 trace_gfs2_glock_queue(gh, 1);
934 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
935 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
936 if (likely(insert_pt == NULL)) {
937 list_add_tail(&gh->gh_list, &gl->gl_holders);
938 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
942 list_add_tail(&gh->gh_list, insert_pt);
944 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
945 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
946 spin_unlock(&gl->gl_lockref.lock);
947 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
948 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
949 spin_lock(&gl->gl_lockref.lock);
954 pr_err("original: %pSR\n", (void *)gh2->gh_ip);
955 pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid));
956 pr_err("lock type: %d req lock state : %d\n",
957 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
958 pr_err("new: %pSR\n", (void *)gh->gh_ip);
959 pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid));
960 pr_err("lock type: %d req lock state : %d\n",
961 gh->gh_gl->gl_name.ln_type, gh->gh_state);
962 gfs2_dump_glock(NULL, gl);
967 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
968 * @gh: the holder structure
970 * if (gh->gh_flags & GL_ASYNC), this never returns an error
972 * Returns: 0, GLR_TRYFAILED, or errno on failure
975 int gfs2_glock_nq(struct gfs2_holder *gh)
977 struct gfs2_glock *gl = gh->gh_gl;
978 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
981 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
984 if (test_bit(GLF_LRU, &gl->gl_flags))
985 gfs2_glock_remove_from_lru(gl);
987 spin_lock(&gl->gl_lockref.lock);
989 if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
990 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
991 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
992 gl->gl_lockref.count++;
993 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
994 gl->gl_lockref.count--;
997 spin_unlock(&gl->gl_lockref.lock);
999 if (!(gh->gh_flags & GL_ASYNC))
1000 error = gfs2_glock_wait(gh);
1006 * gfs2_glock_poll - poll to see if an async request has been completed
1009 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1012 int gfs2_glock_poll(struct gfs2_holder *gh)
1014 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1018 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1019 * @gh: the glock holder
1023 void gfs2_glock_dq(struct gfs2_holder *gh)
1025 struct gfs2_glock *gl = gh->gh_gl;
1026 const struct gfs2_glock_operations *glops = gl->gl_ops;
1030 spin_lock(&gl->gl_lockref.lock);
1031 if (gh->gh_flags & GL_NOCACHE)
1032 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1034 list_del_init(&gh->gh_list);
1035 if (find_first_holder(gl) == NULL) {
1036 if (glops->go_unlock) {
1037 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1038 spin_unlock(&gl->gl_lockref.lock);
1039 glops->go_unlock(gh);
1040 spin_lock(&gl->gl_lockref.lock);
1041 clear_bit(GLF_LOCK, &gl->gl_flags);
1043 if (list_empty(&gl->gl_holders) &&
1044 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1045 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1048 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
1049 gfs2_glock_add_to_lru(gl);
1051 trace_gfs2_glock_queue(gh, 0);
1052 spin_unlock(&gl->gl_lockref.lock);
1053 if (likely(fast_path))
1056 gfs2_glock_hold(gl);
1057 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1058 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1059 gl->gl_name.ln_type == LM_TYPE_INODE)
1060 delay = gl->gl_hold_time;
1061 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1065 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1067 struct gfs2_glock *gl = gh->gh_gl;
1070 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
1074 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1075 * @gh: the holder structure
1079 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1082 gfs2_holder_uninit(gh);
1086 * gfs2_glock_nq_num - acquire a glock based on lock number
1087 * @sdp: the filesystem
1088 * @number: the lock number
1089 * @glops: the glock operations for the type of glock
1090 * @state: the state to acquire the glock in
1091 * @flags: modifier flags for the acquisition
1092 * @gh: the struct gfs2_holder
1097 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1098 const struct gfs2_glock_operations *glops,
1099 unsigned int state, int flags, struct gfs2_holder *gh)
1101 struct gfs2_glock *gl;
1104 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1106 error = gfs2_glock_nq_init(gl, state, flags, gh);
1114 * glock_compare - Compare two struct gfs2_glock structures for sorting
1115 * @arg_a: the first structure
1116 * @arg_b: the second structure
1120 static int glock_compare(const void *arg_a, const void *arg_b)
1122 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1123 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1124 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1125 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1127 if (a->ln_number > b->ln_number)
1129 if (a->ln_number < b->ln_number)
1131 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1136 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1137 * @num_gh: the number of structures
1138 * @ghs: an array of struct gfs2_holder structures
1140 * Returns: 0 on success (all glocks acquired),
1141 * errno on failure (no glocks acquired)
1144 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1145 struct gfs2_holder **p)
1150 for (x = 0; x < num_gh; x++)
1153 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1155 for (x = 0; x < num_gh; x++) {
1156 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1158 error = gfs2_glock_nq(p[x]);
1161 gfs2_glock_dq(p[x]);
1170 * gfs2_glock_nq_m - acquire multiple glocks
1171 * @num_gh: the number of structures
1172 * @ghs: an array of struct gfs2_holder structures
1175 * Returns: 0 on success (all glocks acquired),
1176 * errno on failure (no glocks acquired)
1179 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1181 struct gfs2_holder *tmp[4];
1182 struct gfs2_holder **pph = tmp;
1189 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1190 return gfs2_glock_nq(ghs);
1194 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1199 error = nq_m_sync(num_gh, ghs, pph);
1208 * gfs2_glock_dq_m - release multiple glocks
1209 * @num_gh: the number of structures
1210 * @ghs: an array of struct gfs2_holder structures
1214 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1217 gfs2_glock_dq(&ghs[num_gh]);
1220 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1222 unsigned long delay = 0;
1223 unsigned long holdtime;
1224 unsigned long now = jiffies;
1226 gfs2_glock_hold(gl);
1227 holdtime = gl->gl_tchange + gl->gl_hold_time;
1228 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1229 gl->gl_name.ln_type == LM_TYPE_INODE) {
1230 if (time_before(now, holdtime))
1231 delay = holdtime - now;
1232 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1233 delay = gl->gl_hold_time;
1236 spin_lock(&gl->gl_lockref.lock);
1237 handle_callback(gl, state, delay, true);
1238 spin_unlock(&gl->gl_lockref.lock);
1239 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1244 * gfs2_should_freeze - Figure out if glock should be frozen
1245 * @gl: The glock in question
1247 * Glocks are not frozen if (a) the result of the dlm operation is
1248 * an error, (b) the locking operation was an unlock operation or
1249 * (c) if there is a "noexp" flagged request anywhere in the queue
1251 * Returns: 1 if freezing should occur, 0 otherwise
1254 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1256 const struct gfs2_holder *gh;
1258 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1260 if (gl->gl_target == LM_ST_UNLOCKED)
1263 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1264 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1266 if (LM_FLAG_NOEXP & gh->gh_flags)
1274 * gfs2_glock_complete - Callback used by locking
1275 * @gl: Pointer to the glock
1276 * @ret: The return value from the dlm
1278 * The gl_reply field is under the gl_lockref.lock lock so that it is ok
1279 * to use a bitfield shared with other glock state fields.
1282 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1284 struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
1286 spin_lock(&gl->gl_lockref.lock);
1289 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1290 if (gfs2_should_freeze(gl)) {
1291 set_bit(GLF_FROZEN, &gl->gl_flags);
1292 spin_unlock(&gl->gl_lockref.lock);
1297 gl->gl_lockref.count++;
1298 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1299 spin_unlock(&gl->gl_lockref.lock);
1301 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1305 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1307 struct gfs2_glock *gla, *glb;
1309 gla = list_entry(a, struct gfs2_glock, gl_lru);
1310 glb = list_entry(b, struct gfs2_glock, gl_lru);
1312 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1314 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1321 * gfs2_dispose_glock_lru - Demote a list of glocks
1322 * @list: The list to dispose of
1324 * Disposing of glocks may involve disk accesses, so that here we sort
1325 * the glocks by number (i.e. disk location of the inodes) so that if
1326 * there are any such accesses, they'll be sent in order (mostly).
1328 * Must be called under the lru_lock, but may drop and retake this
1329 * lock. While the lru_lock is dropped, entries may vanish from the
1330 * list, but no new entries will appear on the list (since it is
1334 static void gfs2_dispose_glock_lru(struct list_head *list)
1335 __releases(&lru_lock)
1336 __acquires(&lru_lock)
1338 struct gfs2_glock *gl;
1340 list_sort(NULL, list, glock_cmp);
1342 while(!list_empty(list)) {
1343 gl = list_entry(list->next, struct gfs2_glock, gl_lru);
1344 list_del_init(&gl->gl_lru);
1345 clear_bit(GLF_LRU, &gl->gl_flags);
1346 if (!spin_trylock(&gl->gl_lockref.lock)) {
1348 list_add(&gl->gl_lru, &lru_list);
1349 set_bit(GLF_LRU, &gl->gl_flags);
1350 atomic_inc(&lru_count);
1353 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1354 spin_unlock(&gl->gl_lockref.lock);
1355 goto add_back_to_lru;
1357 gl->gl_lockref.count++;
1359 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1360 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1361 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1362 gl->gl_lockref.count--;
1363 spin_unlock(&gl->gl_lockref.lock);
1364 cond_resched_lock(&lru_lock);
1369 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1370 * @nr: The number of entries to scan
1372 * This function selects the entries on the LRU which are able to
1373 * be demoted, and then kicks off the process by calling
1374 * gfs2_dispose_glock_lru() above.
1377 static long gfs2_scan_glock_lru(int nr)
1379 struct gfs2_glock *gl;
1384 spin_lock(&lru_lock);
1385 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1386 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1388 /* Test for being demotable */
1389 if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
1390 list_move(&gl->gl_lru, &dispose);
1391 atomic_dec(&lru_count);
1396 list_move(&gl->gl_lru, &skipped);
1398 list_splice(&skipped, &lru_list);
1399 if (!list_empty(&dispose))
1400 gfs2_dispose_glock_lru(&dispose);
1401 spin_unlock(&lru_lock);
1406 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1407 struct shrink_control *sc)
1409 if (!(sc->gfp_mask & __GFP_FS))
1411 return gfs2_scan_glock_lru(sc->nr_to_scan);
1414 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1415 struct shrink_control *sc)
1417 return vfs_pressure_ratio(atomic_read(&lru_count));
1420 static struct shrinker glock_shrinker = {
1421 .seeks = DEFAULT_SEEKS,
1422 .count_objects = gfs2_glock_shrink_count,
1423 .scan_objects = gfs2_glock_shrink_scan,
1427 * examine_bucket - Call a function for glock in a hash bucket
1428 * @examiner: the function
1429 * @sdp: the filesystem
1430 * @bucket: the bucket
1434 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1436 struct gfs2_glock *gl;
1437 struct rhash_head *pos, *next;
1438 const struct bucket_table *tbl;
1442 tbl = rht_dereference_rcu(gl_hash_table.tbl, &gl_hash_table);
1443 for (i = 0; i < tbl->size; i++) {
1444 rht_for_each_entry_safe(gl, pos, next, tbl, i, gl_node) {
1445 if ((gl->gl_name.ln_sbd == sdp) &&
1446 lockref_get_not_dead(&gl->gl_lockref))
1455 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1456 * @gl: The glock to thaw
1460 static void thaw_glock(struct gfs2_glock *gl)
1462 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1464 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1465 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
1472 * clear_glock - look at a glock and see if we can free it from glock cache
1473 * @gl: the glock to look at
1477 static void clear_glock(struct gfs2_glock *gl)
1479 gfs2_glock_remove_from_lru(gl);
1481 spin_lock(&gl->gl_lockref.lock);
1482 if (gl->gl_state != LM_ST_UNLOCKED)
1483 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1484 spin_unlock(&gl->gl_lockref.lock);
1485 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1490 * gfs2_glock_thaw - Thaw any frozen glocks
1491 * @sdp: The super block
1495 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1497 glock_hash_walk(thaw_glock, sdp);
1500 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1502 spin_lock(&gl->gl_lockref.lock);
1503 gfs2_dump_glock(seq, gl);
1504 spin_unlock(&gl->gl_lockref.lock);
1507 static void dump_glock_func(struct gfs2_glock *gl)
1509 dump_glock(NULL, gl);
1513 * gfs2_gl_hash_clear - Empty out the glock hash table
1514 * @sdp: the filesystem
1515 * @wait: wait until it's all gone
1517 * Called when unmounting the filesystem.
1520 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1522 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1523 flush_workqueue(glock_workqueue);
1524 glock_hash_walk(clear_glock, sdp);
1525 flush_workqueue(glock_workqueue);
1526 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1527 glock_hash_walk(dump_glock_func, sdp);
1530 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1532 struct gfs2_glock *gl = ip->i_gl;
1535 ret = gfs2_truncatei_resume(ip);
1536 gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0);
1538 spin_lock(&gl->gl_lockref.lock);
1539 clear_bit(GLF_LOCK, &gl->gl_flags);
1541 spin_unlock(&gl->gl_lockref.lock);
1544 static const char *state2str(unsigned state)
1547 case LM_ST_UNLOCKED:
1551 case LM_ST_DEFERRED:
1553 case LM_ST_EXCLUSIVE:
1559 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1562 if (flags & LM_FLAG_TRY)
1564 if (flags & LM_FLAG_TRY_1CB)
1566 if (flags & LM_FLAG_NOEXP)
1568 if (flags & LM_FLAG_ANY)
1570 if (flags & LM_FLAG_PRIORITY)
1572 if (flags & GL_ASYNC)
1574 if (flags & GL_EXACT)
1576 if (flags & GL_NOCACHE)
1578 if (test_bit(HIF_HOLDER, &iflags))
1580 if (test_bit(HIF_WAIT, &iflags))
1582 if (test_bit(HIF_FIRST, &iflags))
1589 * dump_holder - print information about a glock holder
1590 * @seq: the seq_file struct
1591 * @gh: the glock holder
1595 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1597 struct task_struct *gh_owner = NULL;
1601 if (gh->gh_owner_pid)
1602 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1603 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1604 state2str(gh->gh_state),
1605 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1607 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1608 gh_owner ? gh_owner->comm : "(ended)",
1613 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1615 const unsigned long *gflags = &gl->gl_flags;
1618 if (test_bit(GLF_LOCK, gflags))
1620 if (test_bit(GLF_DEMOTE, gflags))
1622 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1624 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1626 if (test_bit(GLF_DIRTY, gflags))
1628 if (test_bit(GLF_LFLUSH, gflags))
1630 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1632 if (test_bit(GLF_REPLY_PENDING, gflags))
1634 if (test_bit(GLF_INITIAL, gflags))
1636 if (test_bit(GLF_FROZEN, gflags))
1638 if (test_bit(GLF_QUEUED, gflags))
1640 if (test_bit(GLF_LRU, gflags))
1644 if (test_bit(GLF_BLOCKING, gflags))
1651 * gfs2_dump_glock - print information about a glock
1652 * @seq: The seq_file struct
1655 * The file format is as follows:
1656 * One line per object, capital letters are used to indicate objects
1657 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1658 * other objects are indented by a single space and follow the glock to
1659 * which they are related. Fields are indicated by lower case letters
1660 * followed by a colon and the field value, except for strings which are in
1661 * [] so that its possible to see if they are composed of spaces for
1662 * example. The field's are n = number (id of the object), f = flags,
1663 * t = type, s = state, r = refcount, e = error, p = pid.
1667 void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1669 const struct gfs2_glock_operations *glops = gl->gl_ops;
1670 unsigned long long dtime;
1671 const struct gfs2_holder *gh;
1672 char gflags_buf[32];
1674 dtime = jiffies - gl->gl_demote_time;
1675 dtime *= 1000000/HZ; /* demote time in uSec */
1676 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1678 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",
1679 state2str(gl->gl_state),
1680 gl->gl_name.ln_type,
1681 (unsigned long long)gl->gl_name.ln_number,
1682 gflags2str(gflags_buf, gl),
1683 state2str(gl->gl_target),
1684 state2str(gl->gl_demote_state), dtime,
1685 atomic_read(&gl->gl_ail_count),
1686 atomic_read(&gl->gl_revokes),
1687 (int)gl->gl_lockref.count, gl->gl_hold_time);
1689 list_for_each_entry(gh, &gl->gl_holders, gh_list)
1690 dump_holder(seq, gh);
1692 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1693 glops->go_dump(seq, gl);
1696 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1698 struct gfs2_glock *gl = iter_ptr;
1700 seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
1701 gl->gl_name.ln_type,
1702 (unsigned long long)gl->gl_name.ln_number,
1703 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1704 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1705 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1706 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1707 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1708 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1709 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1710 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1714 static const char *gfs2_gltype[] = {
1728 static const char *gfs2_stype[] = {
1729 [GFS2_LKS_SRTT] = "srtt",
1730 [GFS2_LKS_SRTTVAR] = "srttvar",
1731 [GFS2_LKS_SRTTB] = "srttb",
1732 [GFS2_LKS_SRTTVARB] = "srttvarb",
1733 [GFS2_LKS_SIRT] = "sirt",
1734 [GFS2_LKS_SIRTVAR] = "sirtvar",
1735 [GFS2_LKS_DCOUNT] = "dlm",
1736 [GFS2_LKS_QCOUNT] = "queue",
1739 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1741 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1743 struct gfs2_sbd *sdp = seq->private;
1744 loff_t pos = *(loff_t *)iter_ptr;
1745 unsigned index = pos >> 3;
1746 unsigned subindex = pos & 0x07;
1749 if (index == 0 && subindex != 0)
1752 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1753 (index == 0) ? "cpu": gfs2_stype[subindex]);
1755 for_each_possible_cpu(i) {
1756 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1759 seq_printf(seq, " %15u", i);
1761 seq_printf(seq, " %15llu", (unsigned long long)lkstats->
1762 lkstats[index - 1].stats[subindex]);
1764 seq_putc(seq, '\n');
1768 int __init gfs2_glock_init(void)
1772 ret = rhashtable_init(&gl_hash_table, &ht_parms);
1776 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1777 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1778 if (!glock_workqueue) {
1779 rhashtable_destroy(&gl_hash_table);
1782 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1783 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1785 if (!gfs2_delete_workqueue) {
1786 destroy_workqueue(glock_workqueue);
1787 rhashtable_destroy(&gl_hash_table);
1791 register_shrinker(&glock_shrinker);
1796 void gfs2_glock_exit(void)
1798 unregister_shrinker(&glock_shrinker);
1799 rhashtable_destroy(&gl_hash_table);
1800 destroy_workqueue(glock_workqueue);
1801 destroy_workqueue(gfs2_delete_workqueue);
1804 static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1806 while ((gi->gl = rhashtable_walk_next(&gi->hti))) {
1807 if (IS_ERR(gi->gl)) {
1808 if (PTR_ERR(gi->gl) == -EAGAIN)
1813 /* Skip entries for other sb and dead entries */
1814 if (gi->sdp == gi->gl->gl_name.ln_sbd &&
1815 !__lockref_is_dead(&gi->gl->gl_lockref))
1820 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1822 struct gfs2_glock_iter *gi = seq->private;
1825 if (rhashtable_walk_init(&gl_hash_table, &gi->hti) != 0)
1827 if (rhashtable_walk_start(&gi->hti) != 0)
1831 gfs2_glock_iter_next(gi);
1832 } while (gi->gl && n--);
1834 gi->last_pos = *pos;
1839 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1842 struct gfs2_glock_iter *gi = seq->private;
1845 gi->last_pos = *pos;
1846 gfs2_glock_iter_next(gi);
1851 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1853 struct gfs2_glock_iter *gi = seq->private;
1856 if (gi->hti.walker) {
1857 rhashtable_walk_stop(&gi->hti);
1858 rhashtable_walk_exit(&gi->hti);
1862 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1864 dump_glock(seq, iter_ptr);
1868 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1871 if (*pos >= GFS2_NR_SBSTATS)
1876 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1880 if (*pos >= GFS2_NR_SBSTATS)
1885 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1890 static const struct seq_operations gfs2_glock_seq_ops = {
1891 .start = gfs2_glock_seq_start,
1892 .next = gfs2_glock_seq_next,
1893 .stop = gfs2_glock_seq_stop,
1894 .show = gfs2_glock_seq_show,
1897 static const struct seq_operations gfs2_glstats_seq_ops = {
1898 .start = gfs2_glock_seq_start,
1899 .next = gfs2_glock_seq_next,
1900 .stop = gfs2_glock_seq_stop,
1901 .show = gfs2_glstats_seq_show,
1904 static const struct seq_operations gfs2_sbstats_seq_ops = {
1905 .start = gfs2_sbstats_seq_start,
1906 .next = gfs2_sbstats_seq_next,
1907 .stop = gfs2_sbstats_seq_stop,
1908 .show = gfs2_sbstats_seq_show,
1911 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
1913 static int gfs2_glocks_open(struct inode *inode, struct file *file)
1915 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1916 sizeof(struct gfs2_glock_iter));
1918 struct seq_file *seq = file->private_data;
1919 struct gfs2_glock_iter *gi = seq->private;
1921 gi->sdp = inode->i_private;
1922 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
1924 seq->size = GFS2_SEQ_GOODSIZE;
1930 static int gfs2_glocks_release(struct inode *inode, struct file *file)
1932 struct seq_file *seq = file->private_data;
1933 struct gfs2_glock_iter *gi = seq->private;
1936 return seq_release_private(inode, file);
1939 static int gfs2_glstats_open(struct inode *inode, struct file *file)
1941 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
1942 sizeof(struct gfs2_glock_iter));
1944 struct seq_file *seq = file->private_data;
1945 struct gfs2_glock_iter *gi = seq->private;
1946 gi->sdp = inode->i_private;
1947 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
1949 seq->size = GFS2_SEQ_GOODSIZE;
1955 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
1957 int ret = seq_open(file, &gfs2_sbstats_seq_ops);
1959 struct seq_file *seq = file->private_data;
1960 seq->private = inode->i_private; /* sdp */
1965 static const struct file_operations gfs2_glocks_fops = {
1966 .owner = THIS_MODULE,
1967 .open = gfs2_glocks_open,
1969 .llseek = seq_lseek,
1970 .release = gfs2_glocks_release,
1973 static const struct file_operations gfs2_glstats_fops = {
1974 .owner = THIS_MODULE,
1975 .open = gfs2_glstats_open,
1977 .llseek = seq_lseek,
1978 .release = gfs2_glocks_release,
1981 static const struct file_operations gfs2_sbstats_fops = {
1982 .owner = THIS_MODULE,
1983 .open = gfs2_sbstats_open,
1985 .llseek = seq_lseek,
1986 .release = seq_release,
1989 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1991 struct dentry *dent;
1993 dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1994 if (IS_ERR_OR_NULL(dent))
1996 sdp->debugfs_dir = dent;
1998 dent = debugfs_create_file("glocks",
2000 sdp->debugfs_dir, sdp,
2002 if (IS_ERR_OR_NULL(dent))
2004 sdp->debugfs_dentry_glocks = dent;
2006 dent = debugfs_create_file("glstats",
2008 sdp->debugfs_dir, sdp,
2009 &gfs2_glstats_fops);
2010 if (IS_ERR_OR_NULL(dent))
2012 sdp->debugfs_dentry_glstats = dent;
2014 dent = debugfs_create_file("sbstats",
2016 sdp->debugfs_dir, sdp,
2017 &gfs2_sbstats_fops);
2018 if (IS_ERR_OR_NULL(dent))
2020 sdp->debugfs_dentry_sbstats = dent;
2024 gfs2_delete_debugfs_file(sdp);
2025 return dent ? PTR_ERR(dent) : -ENOMEM;
2028 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2030 if (sdp->debugfs_dir) {
2031 if (sdp->debugfs_dentry_glocks) {
2032 debugfs_remove(sdp->debugfs_dentry_glocks);
2033 sdp->debugfs_dentry_glocks = NULL;
2035 if (sdp->debugfs_dentry_glstats) {
2036 debugfs_remove(sdp->debugfs_dentry_glstats);
2037 sdp->debugfs_dentry_glstats = NULL;
2039 if (sdp->debugfs_dentry_sbstats) {
2040 debugfs_remove(sdp->debugfs_dentry_sbstats);
2041 sdp->debugfs_dentry_sbstats = NULL;
2043 debugfs_remove(sdp->debugfs_dir);
2044 sdp->debugfs_dir = NULL;
2048 int gfs2_register_debugfs(void)
2050 gfs2_root = debugfs_create_dir("gfs2", NULL);
2051 if (IS_ERR(gfs2_root))
2052 return PTR_ERR(gfs2_root);
2053 return gfs2_root ? 0 : -ENOMEM;
2056 void gfs2_unregister_debugfs(void)
2058 debugfs_remove(gfs2_root);