2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/buffer_head.h>
14 #include <linux/delay.h>
15 #include <linux/sort.h>
16 #include <linux/jhash.h>
17 #include <linux/kallsyms.h>
18 #include <linux/gfs2_ondisk.h>
19 #include <linux/list.h>
20 #include <linux/wait.h>
21 #include <linux/module.h>
22 #include <asm/uaccess.h>
23 #include <linux/seq_file.h>
24 #include <linux/debugfs.h>
25 #include <linux/kthread.h>
26 #include <linux/freezer.h>
27 #include <linux/workqueue.h>
28 #include <linux/jiffies.h>
29 #include <linux/rcupdate.h>
30 #include <linux/rculist_bl.h>
31 #include <linux/bit_spinlock.h>
32 #include <linux/percpu.h>
33 #include <linux/list_sort.h>
34 #include <linux/lockref.h>
47 #define CREATE_TRACE_POINTS
48 #include "trace_gfs2.h"
50 struct gfs2_glock_iter {
51 int hash; /* hash bucket index */
52 unsigned nhash; /* Index within current bucket */
53 struct gfs2_sbd *sdp; /* incore superblock */
54 struct gfs2_glock *gl; /* current glock struct */
55 loff_t last_pos; /* last position */
58 typedef void (*glock_examiner) (struct gfs2_glock * gl);
60 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
62 static struct dentry *gfs2_root;
63 static struct workqueue_struct *glock_workqueue;
64 struct workqueue_struct *gfs2_delete_workqueue;
65 static LIST_HEAD(lru_list);
66 static atomic_t lru_count = ATOMIC_INIT(0);
67 static DEFINE_SPINLOCK(lru_lock);
69 #define GFS2_GL_HASH_SHIFT 15
70 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
71 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
73 static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE];
74 static struct dentry *gfs2_root;
77 * gl_hash() - Turn glock number into hash bucket number
78 * @lock: The glock number
80 * Returns: The number of the corresponding hash bucket
83 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
84 const struct lm_lockname *name)
88 h = jhash(&name->ln_number, sizeof(u64), 0);
89 h = jhash(&name->ln_type, sizeof(unsigned int), h);
90 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
91 h &= GFS2_GL_HASH_MASK;
96 static inline void spin_lock_bucket(unsigned int hash)
98 hlist_bl_lock(&gl_hash_table[hash]);
101 static inline void spin_unlock_bucket(unsigned int hash)
103 hlist_bl_unlock(&gl_hash_table[hash]);
106 static void gfs2_glock_dealloc(struct rcu_head *rcu)
108 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
110 if (gl->gl_ops->go_flags & GLOF_ASPACE) {
111 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
113 kfree(gl->gl_lksb.sb_lvbptr);
114 kmem_cache_free(gfs2_glock_cachep, gl);
118 void gfs2_glock_free(struct gfs2_glock *gl)
120 struct gfs2_sbd *sdp = gl->gl_sbd;
122 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
123 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
124 wake_up(&sdp->sd_glock_wait);
128 * gfs2_glock_hold() - increment reference count on glock
129 * @gl: The glock to hold
133 static void gfs2_glock_hold(struct gfs2_glock *gl)
135 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
136 lockref_get(&gl->gl_lockref);
140 * demote_ok - Check to see if it's ok to unlock a glock
143 * Returns: 1 if it's ok
146 static int demote_ok(const struct gfs2_glock *gl)
148 const struct gfs2_glock_operations *glops = gl->gl_ops;
150 if (gl->gl_state == LM_ST_UNLOCKED)
152 if (!list_empty(&gl->gl_holders))
154 if (glops->go_demote_ok)
155 return glops->go_demote_ok(gl);
160 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
162 spin_lock(&lru_lock);
164 if (!list_empty(&gl->gl_lru))
165 list_del_init(&gl->gl_lru);
167 atomic_inc(&lru_count);
169 list_add_tail(&gl->gl_lru, &lru_list);
170 set_bit(GLF_LRU, &gl->gl_flags);
171 spin_unlock(&lru_lock);
174 static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
176 if (!list_empty(&gl->gl_lru)) {
177 list_del_init(&gl->gl_lru);
178 atomic_dec(&lru_count);
179 clear_bit(GLF_LRU, &gl->gl_flags);
183 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
185 spin_lock(&lru_lock);
186 __gfs2_glock_remove_from_lru(gl);
187 spin_unlock(&lru_lock);
191 * gfs2_glock_put() - Decrement reference count on glock
192 * @gl: The glock to put
196 void gfs2_glock_put(struct gfs2_glock *gl)
198 struct gfs2_sbd *sdp = gl->gl_sbd;
199 struct address_space *mapping = gfs2_glock2aspace(gl);
201 if (lockref_put_or_lock(&gl->gl_lockref))
204 lockref_mark_dead(&gl->gl_lockref);
206 spin_lock(&lru_lock);
207 __gfs2_glock_remove_from_lru(gl);
208 spin_unlock(&lru_lock);
209 spin_unlock(&gl->gl_lockref.lock);
210 spin_lock_bucket(gl->gl_hash);
211 hlist_bl_del_rcu(&gl->gl_list);
212 spin_unlock_bucket(gl->gl_hash);
213 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
214 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
215 trace_gfs2_glock_put(gl);
216 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
220 * search_bucket() - Find struct gfs2_glock by lock number
221 * @bucket: the bucket to search
222 * @name: The lock name
224 * Returns: NULL, or the struct gfs2_glock with the requested number
227 static struct gfs2_glock *search_bucket(unsigned int hash,
228 const struct gfs2_sbd *sdp,
229 const struct lm_lockname *name)
231 struct gfs2_glock *gl;
232 struct hlist_bl_node *h;
234 hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
235 if (!lm_name_equal(&gl->gl_name, name))
237 if (gl->gl_sbd != sdp)
239 if (lockref_get_not_dead(&gl->gl_lockref))
247 * may_grant - check if its ok to grant a new lock
249 * @gh: The lock request which we wish to grant
251 * Returns: true if its ok to grant the lock
254 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
256 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
257 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
258 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
260 if (gl->gl_state == gh->gh_state)
262 if (gh->gh_flags & GL_EXACT)
264 if (gl->gl_state == LM_ST_EXCLUSIVE) {
265 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
267 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
270 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
275 static void gfs2_holder_wake(struct gfs2_holder *gh)
277 clear_bit(HIF_WAIT, &gh->gh_iflags);
278 smp_mb__after_clear_bit();
279 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
283 * do_error - Something unexpected has happened during a lock request
287 static inline void do_error(struct gfs2_glock *gl, const int ret)
289 struct gfs2_holder *gh, *tmp;
291 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
292 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
294 if (ret & LM_OUT_ERROR)
296 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
297 gh->gh_error = GLR_TRYFAILED;
300 list_del_init(&gh->gh_list);
301 trace_gfs2_glock_queue(gh, 0);
302 gfs2_holder_wake(gh);
307 * do_promote - promote as many requests as possible on the current queue
310 * Returns: 1 if there is a blocked holder at the head of the list, or 2
311 * if a type specific operation is underway.
314 static int do_promote(struct gfs2_glock *gl)
315 __releases(&gl->gl_spin)
316 __acquires(&gl->gl_spin)
318 const struct gfs2_glock_operations *glops = gl->gl_ops;
319 struct gfs2_holder *gh, *tmp;
323 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
324 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
326 if (may_grant(gl, gh)) {
327 if (gh->gh_list.prev == &gl->gl_holders &&
329 spin_unlock(&gl->gl_spin);
330 /* FIXME: eliminate this eventually */
331 ret = glops->go_lock(gh);
332 spin_lock(&gl->gl_spin);
337 list_del_init(&gh->gh_list);
338 trace_gfs2_glock_queue(gh, 0);
339 gfs2_holder_wake(gh);
342 set_bit(HIF_HOLDER, &gh->gh_iflags);
343 trace_gfs2_promote(gh, 1);
344 gfs2_holder_wake(gh);
347 set_bit(HIF_HOLDER, &gh->gh_iflags);
348 trace_gfs2_promote(gh, 0);
349 gfs2_holder_wake(gh);
352 if (gh->gh_list.prev == &gl->gl_holders)
361 * find_first_waiter - find the first gh that's waiting for the glock
365 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
367 struct gfs2_holder *gh;
369 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
370 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
377 * state_change - record that the glock is now in a different state
379 * @new_state the new state
383 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
387 held1 = (gl->gl_state != LM_ST_UNLOCKED);
388 held2 = (new_state != LM_ST_UNLOCKED);
390 if (held1 != held2) {
391 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
393 gl->gl_lockref.count++;
395 gl->gl_lockref.count--;
397 if (held1 && held2 && list_empty(&gl->gl_holders))
398 clear_bit(GLF_QUEUED, &gl->gl_flags);
400 if (new_state != gl->gl_target)
401 /* shorten our minimum hold time */
402 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
404 gl->gl_state = new_state;
405 gl->gl_tchange = jiffies;
408 static void gfs2_demote_wake(struct gfs2_glock *gl)
410 gl->gl_demote_state = LM_ST_EXCLUSIVE;
411 clear_bit(GLF_DEMOTE, &gl->gl_flags);
412 smp_mb__after_clear_bit();
413 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
417 * finish_xmote - The DLM has replied to one of our lock requests
419 * @ret: The status from the DLM
423 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
425 const struct gfs2_glock_operations *glops = gl->gl_ops;
426 struct gfs2_holder *gh;
427 unsigned state = ret & LM_OUT_ST_MASK;
430 spin_lock(&gl->gl_spin);
431 trace_gfs2_glock_state_change(gl, state);
432 state_change(gl, state);
433 gh = find_first_waiter(gl);
435 /* Demote to UN request arrived during demote to SH or DF */
436 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
437 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
438 gl->gl_target = LM_ST_UNLOCKED;
440 /* Check for state != intended state */
441 if (unlikely(state != gl->gl_target)) {
442 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
443 /* move to back of queue and try next entry */
444 if (ret & LM_OUT_CANCELED) {
445 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
446 list_move_tail(&gh->gh_list, &gl->gl_holders);
447 gh = find_first_waiter(gl);
448 gl->gl_target = gh->gh_state;
451 /* Some error or failed "try lock" - report it */
452 if ((ret & LM_OUT_ERROR) ||
453 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
454 gl->gl_target = gl->gl_state;
460 /* Unlocked due to conversion deadlock, try again */
463 do_xmote(gl, gh, gl->gl_target);
465 /* Conversion fails, unlock and try again */
468 do_xmote(gl, gh, LM_ST_UNLOCKED);
470 default: /* Everything else */
471 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
474 spin_unlock(&gl->gl_spin);
478 /* Fast path - we got what we asked for */
479 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
480 gfs2_demote_wake(gl);
481 if (state != LM_ST_UNLOCKED) {
482 if (glops->go_xmote_bh) {
483 spin_unlock(&gl->gl_spin);
484 rv = glops->go_xmote_bh(gl, gh);
485 spin_lock(&gl->gl_spin);
496 clear_bit(GLF_LOCK, &gl->gl_flags);
498 spin_unlock(&gl->gl_spin);
502 * do_xmote - Calls the DLM to change the state of a lock
503 * @gl: The lock state
504 * @gh: The holder (only for promotes)
505 * @target: The target lock state
509 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
510 __releases(&gl->gl_spin)
511 __acquires(&gl->gl_spin)
513 const struct gfs2_glock_operations *glops = gl->gl_ops;
514 struct gfs2_sbd *sdp = gl->gl_sbd;
515 unsigned int lck_flags = gh ? gh->gh_flags : 0;
518 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
520 GLOCK_BUG_ON(gl, gl->gl_state == target);
521 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
522 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
524 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
525 do_error(gl, 0); /* Fail queued try locks */
528 set_bit(GLF_BLOCKING, &gl->gl_flags);
529 if ((gl->gl_req == LM_ST_UNLOCKED) ||
530 (gl->gl_state == LM_ST_EXCLUSIVE) ||
531 (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
532 clear_bit(GLF_BLOCKING, &gl->gl_flags);
533 spin_unlock(&gl->gl_spin);
536 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
537 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
538 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
541 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
543 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
545 printk(KERN_ERR "GFS2: lm_lock ret %d\n", ret);
548 } else { /* lock_nolock */
549 finish_xmote(gl, target);
550 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
554 spin_lock(&gl->gl_spin);
558 * find_first_holder - find the first "holder" gh
562 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
564 struct gfs2_holder *gh;
566 if (!list_empty(&gl->gl_holders)) {
567 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
568 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
575 * run_queue - do all outstanding tasks related to a glock
576 * @gl: The glock in question
577 * @nonblock: True if we must not block in run_queue
581 static void run_queue(struct gfs2_glock *gl, const int nonblock)
582 __releases(&gl->gl_spin)
583 __acquires(&gl->gl_spin)
585 struct gfs2_holder *gh = NULL;
588 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
591 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
593 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
594 gl->gl_demote_state != gl->gl_state) {
595 if (find_first_holder(gl))
599 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
600 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
601 gl->gl_target = gl->gl_demote_state;
603 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
604 gfs2_demote_wake(gl);
605 ret = do_promote(gl);
610 gh = find_first_waiter(gl);
611 gl->gl_target = gh->gh_state;
612 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
613 do_error(gl, 0); /* Fail queued try locks */
615 do_xmote(gl, gh, gl->gl_target);
620 clear_bit(GLF_LOCK, &gl->gl_flags);
621 smp_mb__after_clear_bit();
622 gl->gl_lockref.count++;
623 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
624 gl->gl_lockref.count--;
628 clear_bit(GLF_LOCK, &gl->gl_flags);
629 smp_mb__after_clear_bit();
633 static void delete_work_func(struct work_struct *work)
635 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
636 struct gfs2_sbd *sdp = gl->gl_sbd;
637 struct gfs2_inode *ip;
639 u64 no_addr = gl->gl_name.ln_number;
642 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
645 inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
647 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
648 if (inode && !IS_ERR(inode)) {
649 d_prune_aliases(inode);
655 static void glock_work_func(struct work_struct *work)
657 unsigned long delay = 0;
658 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
661 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
662 finish_xmote(gl, gl->gl_reply);
665 spin_lock(&gl->gl_spin);
666 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
667 gl->gl_state != LM_ST_UNLOCKED &&
668 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
669 unsigned long holdtime, now = jiffies;
671 holdtime = gl->gl_tchange + gl->gl_hold_time;
672 if (time_before(now, holdtime))
673 delay = holdtime - now;
676 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
677 set_bit(GLF_DEMOTE, &gl->gl_flags);
681 spin_unlock(&gl->gl_spin);
685 if (gl->gl_name.ln_type != LM_TYPE_INODE)
687 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
695 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
696 * @sdp: The GFS2 superblock
697 * @number: the lock number
698 * @glops: The glock_operations to use
699 * @create: If 0, don't create the glock if it doesn't exist
700 * @glp: the glock is returned here
702 * This does not lock a glock, just finds/creates structures for one.
707 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
708 const struct gfs2_glock_operations *glops, int create,
709 struct gfs2_glock **glp)
711 struct super_block *s = sdp->sd_vfs;
712 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
713 struct gfs2_glock *gl, *tmp;
714 unsigned int hash = gl_hash(sdp, &name);
715 struct address_space *mapping;
716 struct kmem_cache *cachep;
719 gl = search_bucket(hash, sdp, &name);
728 if (glops->go_flags & GLOF_ASPACE)
729 cachep = gfs2_glock_aspace_cachep;
731 cachep = gfs2_glock_cachep;
732 gl = kmem_cache_alloc(cachep, GFP_KERNEL);
736 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
738 if (glops->go_flags & GLOF_LVB) {
739 gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_KERNEL);
740 if (!gl->gl_lksb.sb_lvbptr) {
741 kmem_cache_free(cachep, gl);
746 atomic_inc(&sdp->sd_glock_disposal);
750 gl->gl_lockref.count = 1;
751 gl->gl_state = LM_ST_UNLOCKED;
752 gl->gl_target = LM_ST_UNLOCKED;
753 gl->gl_demote_state = LM_ST_EXCLUSIVE;
756 gl->gl_dstamp = ktime_set(0, 0);
758 /* We use the global stats to estimate the initial per-glock stats */
759 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
761 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
762 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
763 gl->gl_tchange = jiffies;
764 gl->gl_object = NULL;
765 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
766 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
767 INIT_WORK(&gl->gl_delete, delete_work_func);
769 mapping = gfs2_glock2aspace(gl);
771 mapping->a_ops = &gfs2_meta_aops;
772 mapping->host = s->s_bdev->bd_inode;
774 mapping_set_gfp_mask(mapping, GFP_NOFS);
775 mapping->private_data = NULL;
776 mapping->backing_dev_info = s->s_bdi;
777 mapping->writeback_index = 0;
780 spin_lock_bucket(hash);
781 tmp = search_bucket(hash, sdp, &name);
783 spin_unlock_bucket(hash);
784 kfree(gl->gl_lksb.sb_lvbptr);
785 kmem_cache_free(cachep, gl);
786 atomic_dec(&sdp->sd_glock_disposal);
789 hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]);
790 spin_unlock_bucket(hash);
799 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
801 * @state: the state we're requesting
802 * @flags: the modifier flags
803 * @gh: the holder structure
807 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
808 struct gfs2_holder *gh)
810 INIT_LIST_HEAD(&gh->gh_list);
812 gh->gh_ip = (unsigned long)__builtin_return_address(0);
813 gh->gh_owner_pid = get_pid(task_pid(current));
814 gh->gh_state = state;
815 gh->gh_flags = flags;
822 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
823 * @state: the state we're requesting
824 * @flags: the modifier flags
825 * @gh: the holder structure
827 * Don't mess with the glock.
831 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
833 gh->gh_state = state;
834 gh->gh_flags = flags;
836 gh->gh_ip = (unsigned long)__builtin_return_address(0);
837 if (gh->gh_owner_pid)
838 put_pid(gh->gh_owner_pid);
839 gh->gh_owner_pid = get_pid(task_pid(current));
843 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
844 * @gh: the holder structure
848 void gfs2_holder_uninit(struct gfs2_holder *gh)
850 put_pid(gh->gh_owner_pid);
851 gfs2_glock_put(gh->gh_gl);
857 * gfs2_glock_holder_wait
860 * This function and gfs2_glock_demote_wait both show up in the WCHAN
861 * field. Thus I've separated these otherwise identical functions in
862 * order to be more informative to the user.
865 static int gfs2_glock_holder_wait(void *word)
871 static int gfs2_glock_demote_wait(void *word)
878 * gfs2_glock_wait - wait on a glock acquisition
879 * @gh: the glock holder
881 * Returns: 0 on success
884 int gfs2_glock_wait(struct gfs2_holder *gh)
886 unsigned long time1 = jiffies;
889 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
890 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
891 /* Lengthen the minimum hold time. */
892 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
899 * handle_callback - process a demote request
901 * @state: the state the caller wants us to change to
903 * There are only two requests that we are going to see in actual
904 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
907 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
908 unsigned long delay, bool remote)
910 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
912 set_bit(bit, &gl->gl_flags);
913 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
914 gl->gl_demote_state = state;
915 gl->gl_demote_time = jiffies;
916 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
917 gl->gl_demote_state != state) {
918 gl->gl_demote_state = LM_ST_UNLOCKED;
920 if (gl->gl_ops->go_callback)
921 gl->gl_ops->go_callback(gl, remote);
922 trace_gfs2_demote_rq(gl, remote);
925 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
927 struct va_format vaf;
933 seq_vprintf(seq, fmt, args);
938 printk(KERN_ERR " %pV", &vaf);
945 * add_to_queue - Add a holder to the wait queue (but look for recursion)
946 * @gh: the holder structure to add
948 * Eventually we should move the recursive locking trap to a
949 * debugging option or something like that. This is the fast
950 * path and needs to have the minimum number of distractions.
954 static inline void add_to_queue(struct gfs2_holder *gh)
955 __releases(&gl->gl_spin)
956 __acquires(&gl->gl_spin)
958 struct gfs2_glock *gl = gh->gh_gl;
959 struct gfs2_sbd *sdp = gl->gl_sbd;
960 struct list_head *insert_pt = NULL;
961 struct gfs2_holder *gh2;
964 BUG_ON(gh->gh_owner_pid == NULL);
965 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
968 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
969 if (test_bit(GLF_LOCK, &gl->gl_flags))
970 try_futile = !may_grant(gl, gh);
971 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
975 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
976 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
977 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
980 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
982 gh->gh_error = GLR_TRYFAILED;
983 gfs2_holder_wake(gh);
986 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
988 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
989 insert_pt = &gh2->gh_list;
991 set_bit(GLF_QUEUED, &gl->gl_flags);
992 trace_gfs2_glock_queue(gh, 1);
993 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
994 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
995 if (likely(insert_pt == NULL)) {
996 list_add_tail(&gh->gh_list, &gl->gl_holders);
997 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1001 list_add_tail(&gh->gh_list, insert_pt);
1003 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1004 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1005 spin_unlock(&gl->gl_spin);
1006 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1007 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1008 spin_lock(&gl->gl_spin);
1013 printk(KERN_ERR "original: %pSR\n", (void *)gh2->gh_ip);
1014 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1015 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1016 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1017 printk(KERN_ERR "new: %pSR\n", (void *)gh->gh_ip);
1018 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
1019 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1020 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1021 gfs2_dump_glock(NULL, gl);
1026 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1027 * @gh: the holder structure
1029 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1031 * Returns: 0, GLR_TRYFAILED, or errno on failure
1034 int gfs2_glock_nq(struct gfs2_holder *gh)
1036 struct gfs2_glock *gl = gh->gh_gl;
1037 struct gfs2_sbd *sdp = gl->gl_sbd;
1040 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1043 if (test_bit(GLF_LRU, &gl->gl_flags))
1044 gfs2_glock_remove_from_lru(gl);
1046 spin_lock(&gl->gl_spin);
1048 if ((LM_FLAG_NOEXP & gh->gh_flags) &&
1049 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1050 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1052 spin_unlock(&gl->gl_spin);
1054 if (!(gh->gh_flags & GL_ASYNC))
1055 error = gfs2_glock_wait(gh);
1061 * gfs2_glock_poll - poll to see if an async request has been completed
1064 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1067 int gfs2_glock_poll(struct gfs2_holder *gh)
1069 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1073 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1074 * @gh: the glock holder
1078 void gfs2_glock_dq(struct gfs2_holder *gh)
1080 struct gfs2_glock *gl = gh->gh_gl;
1081 const struct gfs2_glock_operations *glops = gl->gl_ops;
1085 spin_lock(&gl->gl_spin);
1086 if (gh->gh_flags & GL_NOCACHE)
1087 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1089 list_del_init(&gh->gh_list);
1090 if (find_first_holder(gl) == NULL) {
1091 if (glops->go_unlock) {
1092 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1093 spin_unlock(&gl->gl_spin);
1094 glops->go_unlock(gh);
1095 spin_lock(&gl->gl_spin);
1096 clear_bit(GLF_LOCK, &gl->gl_flags);
1098 if (list_empty(&gl->gl_holders) &&
1099 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1100 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1103 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
1104 gfs2_glock_add_to_lru(gl);
1106 trace_gfs2_glock_queue(gh, 0);
1107 spin_unlock(&gl->gl_spin);
1108 if (likely(fast_path))
1111 gfs2_glock_hold(gl);
1112 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1113 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1114 gl->gl_name.ln_type == LM_TYPE_INODE)
1115 delay = gl->gl_hold_time;
1116 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1120 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1122 struct gfs2_glock *gl = gh->gh_gl;
1125 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
1129 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1130 * @gh: the holder structure
1134 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1137 gfs2_holder_uninit(gh);
1141 * gfs2_glock_nq_num - acquire a glock based on lock number
1142 * @sdp: the filesystem
1143 * @number: the lock number
1144 * @glops: the glock operations for the type of glock
1145 * @state: the state to acquire the glock in
1146 * @flags: modifier flags for the acquisition
1147 * @gh: the struct gfs2_holder
1152 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1153 const struct gfs2_glock_operations *glops,
1154 unsigned int state, int flags, struct gfs2_holder *gh)
1156 struct gfs2_glock *gl;
1159 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1161 error = gfs2_glock_nq_init(gl, state, flags, gh);
1169 * glock_compare - Compare two struct gfs2_glock structures for sorting
1170 * @arg_a: the first structure
1171 * @arg_b: the second structure
1175 static int glock_compare(const void *arg_a, const void *arg_b)
1177 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1178 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1179 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1180 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1182 if (a->ln_number > b->ln_number)
1184 if (a->ln_number < b->ln_number)
1186 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1191 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1192 * @num_gh: the number of structures
1193 * @ghs: an array of struct gfs2_holder structures
1195 * Returns: 0 on success (all glocks acquired),
1196 * errno on failure (no glocks acquired)
1199 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1200 struct gfs2_holder **p)
1205 for (x = 0; x < num_gh; x++)
1208 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1210 for (x = 0; x < num_gh; x++) {
1211 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1213 error = gfs2_glock_nq(p[x]);
1216 gfs2_glock_dq(p[x]);
1225 * gfs2_glock_nq_m - acquire multiple glocks
1226 * @num_gh: the number of structures
1227 * @ghs: an array of struct gfs2_holder structures
1230 * Returns: 0 on success (all glocks acquired),
1231 * errno on failure (no glocks acquired)
1234 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1236 struct gfs2_holder *tmp[4];
1237 struct gfs2_holder **pph = tmp;
1244 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1245 return gfs2_glock_nq(ghs);
1249 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1254 error = nq_m_sync(num_gh, ghs, pph);
1263 * gfs2_glock_dq_m - release multiple glocks
1264 * @num_gh: the number of structures
1265 * @ghs: an array of struct gfs2_holder structures
1269 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1272 gfs2_glock_dq(&ghs[num_gh]);
1275 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1277 unsigned long delay = 0;
1278 unsigned long holdtime;
1279 unsigned long now = jiffies;
1281 gfs2_glock_hold(gl);
1282 holdtime = gl->gl_tchange + gl->gl_hold_time;
1283 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1284 gl->gl_name.ln_type == LM_TYPE_INODE) {
1285 if (time_before(now, holdtime))
1286 delay = holdtime - now;
1287 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1288 delay = gl->gl_hold_time;
1291 spin_lock(&gl->gl_spin);
1292 handle_callback(gl, state, delay, true);
1293 spin_unlock(&gl->gl_spin);
1294 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1299 * gfs2_should_freeze - Figure out if glock should be frozen
1300 * @gl: The glock in question
1302 * Glocks are not frozen if (a) the result of the dlm operation is
1303 * an error, (b) the locking operation was an unlock operation or
1304 * (c) if there is a "noexp" flagged request anywhere in the queue
1306 * Returns: 1 if freezing should occur, 0 otherwise
1309 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1311 const struct gfs2_holder *gh;
1313 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1315 if (gl->gl_target == LM_ST_UNLOCKED)
1318 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1319 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1321 if (LM_FLAG_NOEXP & gh->gh_flags)
1329 * gfs2_glock_complete - Callback used by locking
1330 * @gl: Pointer to the glock
1331 * @ret: The return value from the dlm
1333 * The gl_reply field is under the gl_spin lock so that it is ok
1334 * to use a bitfield shared with other glock state fields.
1337 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1339 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1341 spin_lock(&gl->gl_spin);
1344 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1345 if (gfs2_should_freeze(gl)) {
1346 set_bit(GLF_FROZEN, &gl->gl_flags);
1347 spin_unlock(&gl->gl_spin);
1352 gl->gl_lockref.count++;
1353 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1354 spin_unlock(&gl->gl_spin);
1356 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1360 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1362 struct gfs2_glock *gla, *glb;
1364 gla = list_entry(a, struct gfs2_glock, gl_lru);
1365 glb = list_entry(b, struct gfs2_glock, gl_lru);
1367 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1369 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1376 * gfs2_dispose_glock_lru - Demote a list of glocks
1377 * @list: The list to dispose of
1379 * Disposing of glocks may involve disk accesses, so that here we sort
1380 * the glocks by number (i.e. disk location of the inodes) so that if
1381 * there are any such accesses, they'll be sent in order (mostly).
1383 * Must be called under the lru_lock, but may drop and retake this
1384 * lock. While the lru_lock is dropped, entries may vanish from the
1385 * list, but no new entries will appear on the list (since it is
1389 static void gfs2_dispose_glock_lru(struct list_head *list)
1390 __releases(&lru_lock)
1391 __acquires(&lru_lock)
1393 struct gfs2_glock *gl;
1395 list_sort(NULL, list, glock_cmp);
1397 while(!list_empty(list)) {
1398 gl = list_entry(list->next, struct gfs2_glock, gl_lru);
1399 list_del_init(&gl->gl_lru);
1400 if (!spin_trylock(&gl->gl_spin)) {
1401 list_add(&gl->gl_lru, &lru_list);
1402 atomic_inc(&lru_count);
1405 clear_bit(GLF_LRU, &gl->gl_flags);
1406 spin_unlock(&lru_lock);
1407 gl->gl_lockref.count++;
1409 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1410 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1411 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1412 gl->gl_lockref.count--;
1413 spin_unlock(&gl->gl_spin);
1414 spin_lock(&lru_lock);
1419 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1420 * @nr: The number of entries to scan
1422 * This function selects the entries on the LRU which are able to
1423 * be demoted, and then kicks off the process by calling
1424 * gfs2_dispose_glock_lru() above.
1427 static long gfs2_scan_glock_lru(int nr)
1429 struct gfs2_glock *gl;
1434 spin_lock(&lru_lock);
1435 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1436 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1438 /* Test for being demotable */
1439 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1440 list_move(&gl->gl_lru, &dispose);
1441 atomic_dec(&lru_count);
1446 list_move(&gl->gl_lru, &skipped);
1448 list_splice(&skipped, &lru_list);
1449 if (!list_empty(&dispose))
1450 gfs2_dispose_glock_lru(&dispose);
1451 spin_unlock(&lru_lock);
1456 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1457 struct shrink_control *sc)
1459 if (!(sc->gfp_mask & __GFP_FS))
1461 return gfs2_scan_glock_lru(sc->nr_to_scan);
1464 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1465 struct shrink_control *sc)
1467 return vfs_pressure_ratio(atomic_read(&lru_count));
1470 static struct shrinker glock_shrinker = {
1471 .seeks = DEFAULT_SEEKS,
1472 .count_objects = gfs2_glock_shrink_count,
1473 .scan_objects = gfs2_glock_shrink_scan,
1477 * examine_bucket - Call a function for glock in a hash bucket
1478 * @examiner: the function
1479 * @sdp: the filesystem
1480 * @bucket: the bucket
1484 static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
1487 struct gfs2_glock *gl;
1488 struct hlist_bl_head *head = &gl_hash_table[hash];
1489 struct hlist_bl_node *pos;
1492 hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
1493 if ((gl->gl_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref))
1500 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1504 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1505 examine_bucket(examiner, sdp, x);
1510 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1511 * @gl: The glock to thaw
1515 static void thaw_glock(struct gfs2_glock *gl)
1517 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1519 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1520 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
1527 * clear_glock - look at a glock and see if we can free it from glock cache
1528 * @gl: the glock to look at
1532 static void clear_glock(struct gfs2_glock *gl)
1534 gfs2_glock_remove_from_lru(gl);
1536 spin_lock(&gl->gl_spin);
1537 if (gl->gl_state != LM_ST_UNLOCKED)
1538 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1539 spin_unlock(&gl->gl_spin);
1540 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1545 * gfs2_glock_thaw - Thaw any frozen glocks
1546 * @sdp: The super block
1550 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1552 glock_hash_walk(thaw_glock, sdp);
1555 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1557 spin_lock(&gl->gl_spin);
1558 gfs2_dump_glock(seq, gl);
1559 spin_unlock(&gl->gl_spin);
1562 static void dump_glock_func(struct gfs2_glock *gl)
1564 dump_glock(NULL, gl);
1568 * gfs2_gl_hash_clear - Empty out the glock hash table
1569 * @sdp: the filesystem
1570 * @wait: wait until it's all gone
1572 * Called when unmounting the filesystem.
1575 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1577 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1578 flush_workqueue(glock_workqueue);
1579 glock_hash_walk(clear_glock, sdp);
1580 flush_workqueue(glock_workqueue);
1581 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1582 glock_hash_walk(dump_glock_func, sdp);
1585 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1587 struct gfs2_glock *gl = ip->i_gl;
1590 ret = gfs2_truncatei_resume(ip);
1591 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1593 spin_lock(&gl->gl_spin);
1594 clear_bit(GLF_LOCK, &gl->gl_flags);
1596 spin_unlock(&gl->gl_spin);
1599 static const char *state2str(unsigned state)
1602 case LM_ST_UNLOCKED:
1606 case LM_ST_DEFERRED:
1608 case LM_ST_EXCLUSIVE:
1614 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1617 if (flags & LM_FLAG_TRY)
1619 if (flags & LM_FLAG_TRY_1CB)
1621 if (flags & LM_FLAG_NOEXP)
1623 if (flags & LM_FLAG_ANY)
1625 if (flags & LM_FLAG_PRIORITY)
1627 if (flags & GL_ASYNC)
1629 if (flags & GL_EXACT)
1631 if (flags & GL_NOCACHE)
1633 if (test_bit(HIF_HOLDER, &iflags))
1635 if (test_bit(HIF_WAIT, &iflags))
1637 if (test_bit(HIF_FIRST, &iflags))
1644 * dump_holder - print information about a glock holder
1645 * @seq: the seq_file struct
1646 * @gh: the glock holder
1650 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1652 struct task_struct *gh_owner = NULL;
1656 if (gh->gh_owner_pid)
1657 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1658 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1659 state2str(gh->gh_state),
1660 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1662 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1663 gh_owner ? gh_owner->comm : "(ended)",
1668 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1670 const unsigned long *gflags = &gl->gl_flags;
1673 if (test_bit(GLF_LOCK, gflags))
1675 if (test_bit(GLF_DEMOTE, gflags))
1677 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1679 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1681 if (test_bit(GLF_DIRTY, gflags))
1683 if (test_bit(GLF_LFLUSH, gflags))
1685 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1687 if (test_bit(GLF_REPLY_PENDING, gflags))
1689 if (test_bit(GLF_INITIAL, gflags))
1691 if (test_bit(GLF_FROZEN, gflags))
1693 if (test_bit(GLF_QUEUED, gflags))
1695 if (test_bit(GLF_LRU, gflags))
1699 if (test_bit(GLF_BLOCKING, gflags))
1706 * gfs2_dump_glock - print information about a glock
1707 * @seq: The seq_file struct
1710 * The file format is as follows:
1711 * One line per object, capital letters are used to indicate objects
1712 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1713 * other objects are indented by a single space and follow the glock to
1714 * which they are related. Fields are indicated by lower case letters
1715 * followed by a colon and the field value, except for strings which are in
1716 * [] so that its possible to see if they are composed of spaces for
1717 * example. The field's are n = number (id of the object), f = flags,
1718 * t = type, s = state, r = refcount, e = error, p = pid.
1722 void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1724 const struct gfs2_glock_operations *glops = gl->gl_ops;
1725 unsigned long long dtime;
1726 const struct gfs2_holder *gh;
1727 char gflags_buf[32];
1729 dtime = jiffies - gl->gl_demote_time;
1730 dtime *= 1000000/HZ; /* demote time in uSec */
1731 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1733 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",
1734 state2str(gl->gl_state),
1735 gl->gl_name.ln_type,
1736 (unsigned long long)gl->gl_name.ln_number,
1737 gflags2str(gflags_buf, gl),
1738 state2str(gl->gl_target),
1739 state2str(gl->gl_demote_state), dtime,
1740 atomic_read(&gl->gl_ail_count),
1741 atomic_read(&gl->gl_revokes),
1742 (int)gl->gl_lockref.count, gl->gl_hold_time);
1744 list_for_each_entry(gh, &gl->gl_holders, gh_list)
1745 dump_holder(seq, gh);
1747 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1748 glops->go_dump(seq, gl);
1751 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1753 struct gfs2_glock *gl = iter_ptr;
1755 seq_printf(seq, "G: n:%u/%llx rtt:%lld/%lld rttb:%lld/%lld irt:%lld/%lld dcnt: %lld qcnt: %lld\n",
1756 gl->gl_name.ln_type,
1757 (unsigned long long)gl->gl_name.ln_number,
1758 (long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1759 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1760 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1761 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1762 (long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1763 (long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1764 (long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1765 (long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1769 static const char *gfs2_gltype[] = {
1783 static const char *gfs2_stype[] = {
1784 [GFS2_LKS_SRTT] = "srtt",
1785 [GFS2_LKS_SRTTVAR] = "srttvar",
1786 [GFS2_LKS_SRTTB] = "srttb",
1787 [GFS2_LKS_SRTTVARB] = "srttvarb",
1788 [GFS2_LKS_SIRT] = "sirt",
1789 [GFS2_LKS_SIRTVAR] = "sirtvar",
1790 [GFS2_LKS_DCOUNT] = "dlm",
1791 [GFS2_LKS_QCOUNT] = "queue",
1794 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1796 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1798 struct gfs2_glock_iter *gi = seq->private;
1799 struct gfs2_sbd *sdp = gi->sdp;
1800 unsigned index = gi->hash >> 3;
1801 unsigned subindex = gi->hash & 0x07;
1805 if (index == 0 && subindex != 0)
1808 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1809 (index == 0) ? "cpu": gfs2_stype[subindex]);
1811 for_each_possible_cpu(i) {
1812 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1816 value = lkstats->lkstats[index - 1].stats[subindex];
1818 seq_printf(seq, " %15lld", (long long)value);
1820 seq_putc(seq, '\n');
1824 int __init gfs2_glock_init(void)
1827 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1828 INIT_HLIST_BL_HEAD(&gl_hash_table[i]);
1831 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1832 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1833 if (!glock_workqueue)
1835 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1836 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1838 if (!gfs2_delete_workqueue) {
1839 destroy_workqueue(glock_workqueue);
1843 register_shrinker(&glock_shrinker);
1848 void gfs2_glock_exit(void)
1850 unregister_shrinker(&glock_shrinker);
1851 destroy_workqueue(glock_workqueue);
1852 destroy_workqueue(gfs2_delete_workqueue);
1855 static inline struct gfs2_glock *glock_hash_chain(unsigned hash)
1857 return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]),
1858 struct gfs2_glock, gl_list);
1861 static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl)
1863 return hlist_bl_entry(rcu_dereference(gl->gl_list.next),
1864 struct gfs2_glock, gl_list);
1867 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1869 struct gfs2_glock *gl;
1874 gi->gl = glock_hash_next(gl);
1877 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1881 gi->gl = glock_hash_chain(gi->hash);
1884 while (gi->gl == NULL) {
1886 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1890 gi->gl = glock_hash_chain(gi->hash);
1893 /* Skip entries for other sb and dead entries */
1894 } while (gi->sdp != gi->gl->gl_sbd ||
1895 __lockref_is_dead(&gi->gl->gl_lockref));
1900 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1902 struct gfs2_glock_iter *gi = seq->private;
1905 if (gi->last_pos <= *pos)
1906 n = gi->nhash + (*pos - gi->last_pos);
1914 if (gfs2_glock_iter_next(gi))
1918 gi->last_pos = *pos;
1922 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1925 struct gfs2_glock_iter *gi = seq->private;
1928 gi->last_pos = *pos;
1929 if (gfs2_glock_iter_next(gi))
1935 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1937 struct gfs2_glock_iter *gi = seq->private;
1944 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1946 dump_glock(seq, iter_ptr);
1950 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1952 struct gfs2_glock_iter *gi = seq->private;
1955 if (*pos >= GFS2_NR_SBSTATS)
1958 return SEQ_START_TOKEN;
1961 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1964 struct gfs2_glock_iter *gi = seq->private;
1967 if (gi->hash >= GFS2_NR_SBSTATS) {
1971 return SEQ_START_TOKEN;
1974 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1979 static const struct seq_operations gfs2_glock_seq_ops = {
1980 .start = gfs2_glock_seq_start,
1981 .next = gfs2_glock_seq_next,
1982 .stop = gfs2_glock_seq_stop,
1983 .show = gfs2_glock_seq_show,
1986 static const struct seq_operations gfs2_glstats_seq_ops = {
1987 .start = gfs2_glock_seq_start,
1988 .next = gfs2_glock_seq_next,
1989 .stop = gfs2_glock_seq_stop,
1990 .show = gfs2_glstats_seq_show,
1993 static const struct seq_operations gfs2_sbstats_seq_ops = {
1994 .start = gfs2_sbstats_seq_start,
1995 .next = gfs2_sbstats_seq_next,
1996 .stop = gfs2_sbstats_seq_stop,
1997 .show = gfs2_sbstats_seq_show,
2000 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
2002 static int gfs2_glocks_open(struct inode *inode, struct file *file)
2004 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
2005 sizeof(struct gfs2_glock_iter));
2007 struct seq_file *seq = file->private_data;
2008 struct gfs2_glock_iter *gi = seq->private;
2009 gi->sdp = inode->i_private;
2010 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2012 seq->size = GFS2_SEQ_GOODSIZE;
2017 static int gfs2_glstats_open(struct inode *inode, struct file *file)
2019 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
2020 sizeof(struct gfs2_glock_iter));
2022 struct seq_file *seq = file->private_data;
2023 struct gfs2_glock_iter *gi = seq->private;
2024 gi->sdp = inode->i_private;
2025 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2027 seq->size = GFS2_SEQ_GOODSIZE;
2032 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
2034 int ret = seq_open_private(file, &gfs2_sbstats_seq_ops,
2035 sizeof(struct gfs2_glock_iter));
2037 struct seq_file *seq = file->private_data;
2038 struct gfs2_glock_iter *gi = seq->private;
2039 gi->sdp = inode->i_private;
2044 static const struct file_operations gfs2_glocks_fops = {
2045 .owner = THIS_MODULE,
2046 .open = gfs2_glocks_open,
2048 .llseek = seq_lseek,
2049 .release = seq_release_private,
2052 static const struct file_operations gfs2_glstats_fops = {
2053 .owner = THIS_MODULE,
2054 .open = gfs2_glstats_open,
2056 .llseek = seq_lseek,
2057 .release = seq_release_private,
2060 static const struct file_operations gfs2_sbstats_fops = {
2061 .owner = THIS_MODULE,
2062 .open = gfs2_sbstats_open,
2064 .llseek = seq_lseek,
2065 .release = seq_release_private,
2068 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
2070 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
2071 if (!sdp->debugfs_dir)
2073 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
2075 sdp->debugfs_dir, sdp,
2077 if (!sdp->debugfs_dentry_glocks)
2080 sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
2082 sdp->debugfs_dir, sdp,
2083 &gfs2_glstats_fops);
2084 if (!sdp->debugfs_dentry_glstats)
2087 sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
2089 sdp->debugfs_dir, sdp,
2090 &gfs2_sbstats_fops);
2091 if (!sdp->debugfs_dentry_sbstats)
2096 gfs2_delete_debugfs_file(sdp);
2100 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2102 if (sdp->debugfs_dir) {
2103 if (sdp->debugfs_dentry_glocks) {
2104 debugfs_remove(sdp->debugfs_dentry_glocks);
2105 sdp->debugfs_dentry_glocks = NULL;
2107 if (sdp->debugfs_dentry_glstats) {
2108 debugfs_remove(sdp->debugfs_dentry_glstats);
2109 sdp->debugfs_dentry_glstats = NULL;
2111 if (sdp->debugfs_dentry_sbstats) {
2112 debugfs_remove(sdp->debugfs_dentry_sbstats);
2113 sdp->debugfs_dentry_sbstats = NULL;
2115 debugfs_remove(sdp->debugfs_dir);
2116 sdp->debugfs_dir = NULL;
2120 int gfs2_register_debugfs(void)
2122 gfs2_root = debugfs_create_dir("gfs2", NULL);
2123 return gfs2_root ? 0 : -ENOMEM;
2126 void gfs2_unregister_debugfs(void)
2128 debugfs_remove(gfs2_root);