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>
41 #define CREATE_TRACE_POINTS
42 #include "trace_gfs2.h"
44 struct gfs2_gl_hash_bucket {
45 struct hlist_head hb_list;
48 struct gfs2_glock_iter {
49 int hash; /* hash bucket index */
50 struct gfs2_sbd *sdp; /* incore superblock */
51 struct gfs2_glock *gl; /* current glock struct */
52 char string[512]; /* scratch space */
55 typedef void (*glock_examiner) (struct gfs2_glock * gl);
57 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
58 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
59 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
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 gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
74 static struct dentry *gfs2_root;
77 * Despite what you might think, the numbers below are not arbitrary :-)
78 * They are taken from the ipv4 routing hash code, which is well tested
79 * and thus should be nearly optimal. Later on we might tweek the numbers
80 * but for now this should be fine.
82 * The reason for putting the locks in a separate array from the list heads
83 * is that we can have fewer locks than list heads and save memory. We use
84 * the same hash function for both, but with a different hash mask.
86 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
87 defined(CONFIG_PROVE_LOCKING)
90 # define GL_HASH_LOCK_SZ 256
93 # define GL_HASH_LOCK_SZ 4096
95 # define GL_HASH_LOCK_SZ 2048
97 # define GL_HASH_LOCK_SZ 1024
99 # define GL_HASH_LOCK_SZ 512
101 # define GL_HASH_LOCK_SZ 256
105 /* We never want more locks than chains */
106 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
107 # undef GL_HASH_LOCK_SZ
108 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
111 static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
113 static inline rwlock_t *gl_lock_addr(unsigned int x)
115 return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
117 #else /* not SMP, so no spinlocks required */
118 static inline rwlock_t *gl_lock_addr(unsigned int x)
125 * gl_hash() - Turn glock number into hash bucket number
126 * @lock: The glock number
128 * Returns: The number of the corresponding hash bucket
131 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
132 const struct lm_lockname *name)
136 h = jhash(&name->ln_number, sizeof(u64), 0);
137 h = jhash(&name->ln_type, sizeof(unsigned int), h);
138 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
139 h &= GFS2_GL_HASH_MASK;
145 * glock_free() - Perform a few checks and then release struct gfs2_glock
146 * @gl: The glock to release
148 * Also calls lock module to release its internal structure for this glock.
152 static void glock_free(struct gfs2_glock *gl)
154 struct gfs2_sbd *sdp = gl->gl_sbd;
155 struct address_space *mapping = gfs2_glock2aspace(gl);
156 struct kmem_cache *cachep = gfs2_glock_cachep;
158 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
159 trace_gfs2_glock_put(gl);
161 cachep = gfs2_glock_aspace_cachep;
162 sdp->sd_lockstruct.ls_ops->lm_put_lock(cachep, gl);
166 * gfs2_glock_hold() - increment reference count on glock
167 * @gl: The glock to hold
171 void gfs2_glock_hold(struct gfs2_glock *gl)
173 GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0);
174 atomic_inc(&gl->gl_ref);
178 * demote_ok - Check to see if it's ok to unlock a glock
181 * Returns: 1 if it's ok
184 static int demote_ok(const struct gfs2_glock *gl)
186 const struct gfs2_glock_operations *glops = gl->gl_ops;
188 if (gl->gl_state == LM_ST_UNLOCKED)
190 if (!list_empty(&gl->gl_holders))
192 if (glops->go_demote_ok)
193 return glops->go_demote_ok(gl);
198 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
203 static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
206 may_reclaim = (demote_ok(gl) &&
207 (atomic_read(&gl->gl_ref) == 1 ||
208 (gl->gl_name.ln_type == LM_TYPE_INODE &&
209 atomic_read(&gl->gl_ref) <= 2)));
210 spin_lock(&lru_lock);
211 if (list_empty(&gl->gl_lru) && may_reclaim) {
212 list_add_tail(&gl->gl_lru, &lru_list);
213 atomic_inc(&lru_count);
215 spin_unlock(&lru_lock);
219 * gfs2_glock_put_nolock() - Decrement reference count on glock
220 * @gl: The glock to put
222 * This function should only be used if the caller has its own reference
223 * to the glock, in addition to the one it is dropping.
226 void gfs2_glock_put_nolock(struct gfs2_glock *gl)
228 if (atomic_dec_and_test(&gl->gl_ref))
230 gfs2_glock_schedule_for_reclaim(gl);
234 * gfs2_glock_put() - Decrement reference count on glock
235 * @gl: The glock to put
239 int gfs2_glock_put(struct gfs2_glock *gl)
243 write_lock(gl_lock_addr(gl->gl_hash));
244 if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) {
245 hlist_del(&gl->gl_list);
246 if (!list_empty(&gl->gl_lru)) {
247 list_del_init(&gl->gl_lru);
248 atomic_dec(&lru_count);
250 spin_unlock(&lru_lock);
251 write_unlock(gl_lock_addr(gl->gl_hash));
252 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
257 spin_lock(&gl->gl_spin);
258 gfs2_glock_schedule_for_reclaim(gl);
259 spin_unlock(&gl->gl_spin);
260 write_unlock(gl_lock_addr(gl->gl_hash));
266 * search_bucket() - Find struct gfs2_glock by lock number
267 * @bucket: the bucket to search
268 * @name: The lock name
270 * Returns: NULL, or the struct gfs2_glock with the requested number
273 static struct gfs2_glock *search_bucket(unsigned int hash,
274 const struct gfs2_sbd *sdp,
275 const struct lm_lockname *name)
277 struct gfs2_glock *gl;
278 struct hlist_node *h;
280 hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
281 if (!lm_name_equal(&gl->gl_name, name))
283 if (gl->gl_sbd != sdp)
286 atomic_inc(&gl->gl_ref);
295 * may_grant - check if its ok to grant a new lock
297 * @gh: The lock request which we wish to grant
299 * Returns: true if its ok to grant the lock
302 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
304 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
305 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
306 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
308 if (gl->gl_state == gh->gh_state)
310 if (gh->gh_flags & GL_EXACT)
312 if (gl->gl_state == LM_ST_EXCLUSIVE) {
313 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
315 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
318 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
323 static void gfs2_holder_wake(struct gfs2_holder *gh)
325 clear_bit(HIF_WAIT, &gh->gh_iflags);
326 smp_mb__after_clear_bit();
327 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
331 * do_promote - promote as many requests as possible on the current queue
334 * Returns: 1 if there is a blocked holder at the head of the list, or 2
335 * if a type specific operation is underway.
338 static int do_promote(struct gfs2_glock *gl)
339 __releases(&gl->gl_spin)
340 __acquires(&gl->gl_spin)
342 const struct gfs2_glock_operations *glops = gl->gl_ops;
343 struct gfs2_holder *gh, *tmp;
347 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
348 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
350 if (may_grant(gl, gh)) {
351 if (gh->gh_list.prev == &gl->gl_holders &&
353 spin_unlock(&gl->gl_spin);
354 /* FIXME: eliminate this eventually */
355 ret = glops->go_lock(gh);
356 spin_lock(&gl->gl_spin);
361 list_del_init(&gh->gh_list);
362 trace_gfs2_glock_queue(gh, 0);
363 gfs2_holder_wake(gh);
366 set_bit(HIF_HOLDER, &gh->gh_iflags);
367 trace_gfs2_promote(gh, 1);
368 gfs2_holder_wake(gh);
371 set_bit(HIF_HOLDER, &gh->gh_iflags);
372 trace_gfs2_promote(gh, 0);
373 gfs2_holder_wake(gh);
376 if (gh->gh_list.prev == &gl->gl_holders)
384 * do_error - Something unexpected has happened during a lock request
388 static inline void do_error(struct gfs2_glock *gl, const int ret)
390 struct gfs2_holder *gh, *tmp;
392 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
393 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
395 if (ret & LM_OUT_ERROR)
397 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
398 gh->gh_error = GLR_TRYFAILED;
401 list_del_init(&gh->gh_list);
402 trace_gfs2_glock_queue(gh, 0);
403 gfs2_holder_wake(gh);
408 * find_first_waiter - find the first gh that's waiting for the glock
412 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
414 struct gfs2_holder *gh;
416 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
417 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
424 * state_change - record that the glock is now in a different state
426 * @new_state the new state
430 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
434 held1 = (gl->gl_state != LM_ST_UNLOCKED);
435 held2 = (new_state != LM_ST_UNLOCKED);
437 if (held1 != held2) {
441 gfs2_glock_put_nolock(gl);
444 gl->gl_state = new_state;
445 gl->gl_tchange = jiffies;
448 static void gfs2_demote_wake(struct gfs2_glock *gl)
450 gl->gl_demote_state = LM_ST_EXCLUSIVE;
451 clear_bit(GLF_DEMOTE, &gl->gl_flags);
452 smp_mb__after_clear_bit();
453 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
457 * finish_xmote - The DLM has replied to one of our lock requests
459 * @ret: The status from the DLM
463 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
465 const struct gfs2_glock_operations *glops = gl->gl_ops;
466 struct gfs2_holder *gh;
467 unsigned state = ret & LM_OUT_ST_MASK;
470 spin_lock(&gl->gl_spin);
471 trace_gfs2_glock_state_change(gl, state);
472 state_change(gl, state);
473 gh = find_first_waiter(gl);
475 /* Demote to UN request arrived during demote to SH or DF */
476 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
477 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
478 gl->gl_target = LM_ST_UNLOCKED;
480 /* Check for state != intended state */
481 if (unlikely(state != gl->gl_target)) {
482 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
483 /* move to back of queue and try next entry */
484 if (ret & LM_OUT_CANCELED) {
485 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
486 list_move_tail(&gh->gh_list, &gl->gl_holders);
487 gh = find_first_waiter(gl);
488 gl->gl_target = gh->gh_state;
491 /* Some error or failed "try lock" - report it */
492 if ((ret & LM_OUT_ERROR) ||
493 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
494 gl->gl_target = gl->gl_state;
500 /* Unlocked due to conversion deadlock, try again */
503 do_xmote(gl, gh, gl->gl_target);
505 /* Conversion fails, unlock and try again */
508 do_xmote(gl, gh, LM_ST_UNLOCKED);
510 default: /* Everything else */
511 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
514 spin_unlock(&gl->gl_spin);
518 /* Fast path - we got what we asked for */
519 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
520 gfs2_demote_wake(gl);
521 if (state != LM_ST_UNLOCKED) {
522 if (glops->go_xmote_bh) {
523 spin_unlock(&gl->gl_spin);
524 rv = glops->go_xmote_bh(gl, gh);
525 spin_lock(&gl->gl_spin);
536 clear_bit(GLF_LOCK, &gl->gl_flags);
538 spin_unlock(&gl->gl_spin);
541 static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
542 unsigned int req_state,
545 int ret = LM_OUT_ERROR;
547 if (!sdp->sd_lockstruct.ls_ops->lm_lock)
548 return req_state == LM_ST_UNLOCKED ? 0 : req_state;
550 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
551 ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock,
557 * do_xmote - Calls the DLM to change the state of a lock
558 * @gl: The lock state
559 * @gh: The holder (only for promotes)
560 * @target: The target lock state
564 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
565 __releases(&gl->gl_spin)
566 __acquires(&gl->gl_spin)
568 const struct gfs2_glock_operations *glops = gl->gl_ops;
569 struct gfs2_sbd *sdp = gl->gl_sbd;
570 unsigned int lck_flags = gh ? gh->gh_flags : 0;
573 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
575 BUG_ON(gl->gl_state == target);
576 BUG_ON(gl->gl_state == gl->gl_target);
577 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
579 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
580 do_error(gl, 0); /* Fail queued try locks */
582 spin_unlock(&gl->gl_spin);
583 if (glops->go_xmote_th)
584 glops->go_xmote_th(gl);
585 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
586 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
587 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
590 if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
591 gl->gl_state == LM_ST_DEFERRED) &&
592 !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
593 lck_flags |= LM_FLAG_TRY_1CB;
594 ret = gfs2_lm_lock(sdp, gl, target, lck_flags);
596 if (!(ret & LM_OUT_ASYNC)) {
597 finish_xmote(gl, ret);
598 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
601 GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
603 spin_lock(&gl->gl_spin);
607 * find_first_holder - find the first "holder" gh
611 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
613 struct gfs2_holder *gh;
615 if (!list_empty(&gl->gl_holders)) {
616 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
617 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
624 * run_queue - do all outstanding tasks related to a glock
625 * @gl: The glock in question
626 * @nonblock: True if we must not block in run_queue
630 static void run_queue(struct gfs2_glock *gl, const int nonblock)
631 __releases(&gl->gl_spin)
632 __acquires(&gl->gl_spin)
634 struct gfs2_holder *gh = NULL;
637 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
640 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
642 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
643 gl->gl_demote_state != gl->gl_state) {
644 if (find_first_holder(gl))
648 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
649 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
650 gl->gl_target = gl->gl_demote_state;
652 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
653 gfs2_demote_wake(gl);
654 ret = do_promote(gl);
659 gh = find_first_waiter(gl);
660 gl->gl_target = gh->gh_state;
661 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
662 do_error(gl, 0); /* Fail queued try locks */
664 do_xmote(gl, gh, gl->gl_target);
669 clear_bit(GLF_LOCK, &gl->gl_flags);
670 smp_mb__after_clear_bit();
672 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
673 gfs2_glock_put_nolock(gl);
677 clear_bit(GLF_LOCK, &gl->gl_flags);
678 smp_mb__after_clear_bit();
682 static void delete_work_func(struct work_struct *work)
684 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
685 struct gfs2_sbd *sdp = gl->gl_sbd;
686 struct gfs2_inode *ip = NULL;
690 spin_lock(&gl->gl_spin);
691 ip = (struct gfs2_inode *)gl->gl_object;
693 no_addr = ip->i_no_addr;
694 spin_unlock(&gl->gl_spin);
696 inode = gfs2_ilookup(sdp->sd_vfs, no_addr);
698 d_prune_aliases(inode);
705 static void glock_work_func(struct work_struct *work)
707 unsigned long delay = 0;
708 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
709 struct gfs2_holder *gh;
712 if (unlikely(test_bit(GLF_FROZEN, &gl->gl_flags))) {
713 spin_lock(&gl->gl_spin);
714 gh = find_first_waiter(gl);
715 if (gh && (gh->gh_flags & LM_FLAG_NOEXP) &&
716 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
717 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
718 spin_unlock(&gl->gl_spin);
721 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
722 finish_xmote(gl, gl->gl_reply);
725 spin_lock(&gl->gl_spin);
726 if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
727 gl->gl_state != LM_ST_UNLOCKED &&
728 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
729 unsigned long holdtime, now = jiffies;
730 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
731 if (time_before(now, holdtime))
732 delay = holdtime - now;
733 set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags);
736 spin_unlock(&gl->gl_spin);
738 queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
745 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
746 * @sdp: The GFS2 superblock
747 * @number: the lock number
748 * @glops: The glock_operations to use
749 * @create: If 0, don't create the glock if it doesn't exist
750 * @glp: the glock is returned here
752 * This does not lock a glock, just finds/creates structures for one.
757 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
758 const struct gfs2_glock_operations *glops, int create,
759 struct gfs2_glock **glp)
761 struct super_block *s = sdp->sd_vfs;
762 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
763 struct gfs2_glock *gl, *tmp;
764 unsigned int hash = gl_hash(sdp, &name);
765 struct address_space *mapping;
767 read_lock(gl_lock_addr(hash));
768 gl = search_bucket(hash, sdp, &name);
769 read_unlock(gl_lock_addr(hash));
777 if (glops->go_flags & GLOF_ASPACE)
778 gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL);
780 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
784 atomic_inc(&sdp->sd_glock_disposal);
787 atomic_set(&gl->gl_ref, 1);
788 gl->gl_state = LM_ST_UNLOCKED;
789 gl->gl_target = LM_ST_UNLOCKED;
790 gl->gl_demote_state = LM_ST_EXCLUSIVE;
793 snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number);
794 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
795 gl->gl_lksb.sb_lvbptr = gl->gl_lvb;
796 gl->gl_tchange = jiffies;
797 gl->gl_object = NULL;
799 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
800 INIT_WORK(&gl->gl_delete, delete_work_func);
802 mapping = gfs2_glock2aspace(gl);
804 mapping->a_ops = &gfs2_meta_aops;
805 mapping->host = s->s_bdev->bd_inode;
807 mapping_set_gfp_mask(mapping, GFP_NOFS);
808 mapping->assoc_mapping = NULL;
809 mapping->backing_dev_info = s->s_bdi;
810 mapping->writeback_index = 0;
813 write_lock(gl_lock_addr(hash));
814 tmp = search_bucket(hash, sdp, &name);
816 write_unlock(gl_lock_addr(hash));
820 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
821 write_unlock(gl_lock_addr(hash));
830 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
832 * @state: the state we're requesting
833 * @flags: the modifier flags
834 * @gh: the holder structure
838 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
839 struct gfs2_holder *gh)
841 INIT_LIST_HEAD(&gh->gh_list);
843 gh->gh_ip = (unsigned long)__builtin_return_address(0);
844 gh->gh_owner_pid = get_pid(task_pid(current));
845 gh->gh_state = state;
846 gh->gh_flags = flags;
853 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
854 * @state: the state we're requesting
855 * @flags: the modifier flags
856 * @gh: the holder structure
858 * Don't mess with the glock.
862 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
864 gh->gh_state = state;
865 gh->gh_flags = flags;
867 gh->gh_ip = (unsigned long)__builtin_return_address(0);
868 if (gh->gh_owner_pid)
869 put_pid(gh->gh_owner_pid);
870 gh->gh_owner_pid = get_pid(task_pid(current));
874 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
875 * @gh: the holder structure
879 void gfs2_holder_uninit(struct gfs2_holder *gh)
881 put_pid(gh->gh_owner_pid);
882 gfs2_glock_put(gh->gh_gl);
888 * gfs2_glock_holder_wait
891 * This function and gfs2_glock_demote_wait both show up in the WCHAN
892 * field. Thus I've separated these otherwise identical functions in
893 * order to be more informative to the user.
896 static int gfs2_glock_holder_wait(void *word)
902 static int gfs2_glock_demote_wait(void *word)
908 static void wait_on_holder(struct gfs2_holder *gh)
911 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
914 static void wait_on_demote(struct gfs2_glock *gl)
917 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
921 * handle_callback - process a demote request
923 * @state: the state the caller wants us to change to
925 * There are only two requests that we are going to see in actual
926 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
929 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
932 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
934 set_bit(bit, &gl->gl_flags);
935 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
936 gl->gl_demote_state = state;
937 gl->gl_demote_time = jiffies;
938 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
939 gl->gl_demote_state != state) {
940 gl->gl_demote_state = LM_ST_UNLOCKED;
942 if (gl->gl_ops->go_callback)
943 gl->gl_ops->go_callback(gl);
944 trace_gfs2_demote_rq(gl);
948 * gfs2_glock_wait - wait on a glock acquisition
949 * @gh: the glock holder
951 * Returns: 0 on success
954 int gfs2_glock_wait(struct gfs2_holder *gh)
960 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
966 struct gfs2_glock_iter *gi = seq->private;
967 vsprintf(gi->string, fmt, args);
968 seq_printf(seq, gi->string);
970 printk(KERN_ERR " ");
977 * add_to_queue - Add a holder to the wait queue (but look for recursion)
978 * @gh: the holder structure to add
980 * Eventually we should move the recursive locking trap to a
981 * debugging option or something like that. This is the fast
982 * path and needs to have the minimum number of distractions.
986 static inline void add_to_queue(struct gfs2_holder *gh)
987 __releases(&gl->gl_spin)
988 __acquires(&gl->gl_spin)
990 struct gfs2_glock *gl = gh->gh_gl;
991 struct gfs2_sbd *sdp = gl->gl_sbd;
992 struct list_head *insert_pt = NULL;
993 struct gfs2_holder *gh2;
996 BUG_ON(gh->gh_owner_pid == NULL);
997 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
1000 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
1001 if (test_bit(GLF_LOCK, &gl->gl_flags))
1003 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
1007 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
1008 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
1009 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
1010 goto trap_recursive;
1012 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
1013 !may_grant(gl, gh)) {
1015 gh->gh_error = GLR_TRYFAILED;
1016 gfs2_holder_wake(gh);
1019 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
1021 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
1022 insert_pt = &gh2->gh_list;
1024 if (likely(insert_pt == NULL)) {
1025 list_add_tail(&gh->gh_list, &gl->gl_holders);
1026 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1030 trace_gfs2_glock_queue(gh, 1);
1031 list_add_tail(&gh->gh_list, insert_pt);
1033 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1034 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1035 spin_unlock(&gl->gl_spin);
1036 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1037 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1038 spin_lock(&gl->gl_spin);
1043 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
1044 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1045 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1046 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1047 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
1048 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
1049 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1050 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1051 __dump_glock(NULL, gl);
1056 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1057 * @gh: the holder structure
1059 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1061 * Returns: 0, GLR_TRYFAILED, or errno on failure
1064 int gfs2_glock_nq(struct gfs2_holder *gh)
1066 struct gfs2_glock *gl = gh->gh_gl;
1067 struct gfs2_sbd *sdp = gl->gl_sbd;
1070 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1073 spin_lock(&gl->gl_spin);
1076 spin_unlock(&gl->gl_spin);
1078 if (!(gh->gh_flags & GL_ASYNC))
1079 error = gfs2_glock_wait(gh);
1085 * gfs2_glock_poll - poll to see if an async request has been completed
1088 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1091 int gfs2_glock_poll(struct gfs2_holder *gh)
1093 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1097 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1098 * @gh: the glock holder
1102 void gfs2_glock_dq(struct gfs2_holder *gh)
1104 struct gfs2_glock *gl = gh->gh_gl;
1105 const struct gfs2_glock_operations *glops = gl->gl_ops;
1109 spin_lock(&gl->gl_spin);
1110 if (gh->gh_flags & GL_NOCACHE)
1111 handle_callback(gl, LM_ST_UNLOCKED, 0);
1113 list_del_init(&gh->gh_list);
1114 if (find_first_holder(gl) == NULL) {
1115 if (glops->go_unlock) {
1116 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1117 spin_unlock(&gl->gl_spin);
1118 glops->go_unlock(gh);
1119 spin_lock(&gl->gl_spin);
1120 clear_bit(GLF_LOCK, &gl->gl_flags);
1122 if (list_empty(&gl->gl_holders) &&
1123 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1124 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1127 trace_gfs2_glock_queue(gh, 0);
1128 spin_unlock(&gl->gl_spin);
1129 if (likely(fast_path))
1132 gfs2_glock_hold(gl);
1133 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1134 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1135 delay = gl->gl_ops->go_min_hold_time;
1136 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1140 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1142 struct gfs2_glock *gl = gh->gh_gl;
1148 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1149 * @gh: the holder structure
1153 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1156 gfs2_holder_uninit(gh);
1160 * gfs2_glock_nq_num - acquire a glock based on lock number
1161 * @sdp: the filesystem
1162 * @number: the lock number
1163 * @glops: the glock operations for the type of glock
1164 * @state: the state to acquire the glock in
1165 * @flags: modifier flags for the aquisition
1166 * @gh: the struct gfs2_holder
1171 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1172 const struct gfs2_glock_operations *glops,
1173 unsigned int state, int flags, struct gfs2_holder *gh)
1175 struct gfs2_glock *gl;
1178 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1180 error = gfs2_glock_nq_init(gl, state, flags, gh);
1188 * glock_compare - Compare two struct gfs2_glock structures for sorting
1189 * @arg_a: the first structure
1190 * @arg_b: the second structure
1194 static int glock_compare(const void *arg_a, const void *arg_b)
1196 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1197 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1198 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1199 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1201 if (a->ln_number > b->ln_number)
1203 if (a->ln_number < b->ln_number)
1205 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1210 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1211 * @num_gh: the number of structures
1212 * @ghs: an array of struct gfs2_holder structures
1214 * Returns: 0 on success (all glocks acquired),
1215 * errno on failure (no glocks acquired)
1218 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1219 struct gfs2_holder **p)
1224 for (x = 0; x < num_gh; x++)
1227 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1229 for (x = 0; x < num_gh; x++) {
1230 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1232 error = gfs2_glock_nq(p[x]);
1235 gfs2_glock_dq(p[x]);
1244 * gfs2_glock_nq_m - acquire multiple glocks
1245 * @num_gh: the number of structures
1246 * @ghs: an array of struct gfs2_holder structures
1249 * Returns: 0 on success (all glocks acquired),
1250 * errno on failure (no glocks acquired)
1253 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1255 struct gfs2_holder *tmp[4];
1256 struct gfs2_holder **pph = tmp;
1263 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1264 return gfs2_glock_nq(ghs);
1268 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1273 error = nq_m_sync(num_gh, ghs, pph);
1282 * gfs2_glock_dq_m - release multiple glocks
1283 * @num_gh: the number of structures
1284 * @ghs: an array of struct gfs2_holder structures
1288 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1292 for (x = 0; x < num_gh; x++)
1293 gfs2_glock_dq(&ghs[x]);
1297 * gfs2_glock_dq_uninit_m - release multiple glocks
1298 * @num_gh: the number of structures
1299 * @ghs: an array of struct gfs2_holder structures
1303 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1307 for (x = 0; x < num_gh; x++)
1308 gfs2_glock_dq_uninit(&ghs[x]);
1311 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1313 unsigned long delay = 0;
1314 unsigned long holdtime;
1315 unsigned long now = jiffies;
1317 gfs2_glock_hold(gl);
1318 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
1319 if (time_before(now, holdtime))
1320 delay = holdtime - now;
1321 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1322 delay = gl->gl_ops->go_min_hold_time;
1324 spin_lock(&gl->gl_spin);
1325 handle_callback(gl, state, delay);
1326 spin_unlock(&gl->gl_spin);
1327 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1332 * gfs2_glock_complete - Callback used by locking
1333 * @gl: Pointer to the glock
1334 * @ret: The return value from the dlm
1338 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1340 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1342 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) {
1343 struct gfs2_holder *gh;
1344 spin_lock(&gl->gl_spin);
1345 gh = find_first_waiter(gl);
1346 if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) &&
1347 (gl->gl_target != LM_ST_UNLOCKED)) ||
1348 ((ret & ~LM_OUT_ST_MASK) != 0))
1349 set_bit(GLF_FROZEN, &gl->gl_flags);
1350 spin_unlock(&gl->gl_spin);
1351 if (test_bit(GLF_FROZEN, &gl->gl_flags))
1354 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1355 gfs2_glock_hold(gl);
1356 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1361 static int gfs2_shrink_glock_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
1363 struct gfs2_glock *gl;
1371 if (!(gfp_mask & __GFP_FS))
1374 spin_lock(&lru_lock);
1375 while(nr && !list_empty(&lru_list)) {
1376 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1377 list_del_init(&gl->gl_lru);
1378 atomic_dec(&lru_count);
1380 /* Test for being demotable */
1381 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1382 gfs2_glock_hold(gl);
1383 spin_unlock(&lru_lock);
1384 spin_lock(&gl->gl_spin);
1385 may_demote = demote_ok(gl);
1387 handle_callback(gl, LM_ST_UNLOCKED, 0);
1390 clear_bit(GLF_LOCK, &gl->gl_flags);
1391 smp_mb__after_clear_bit();
1392 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1393 gfs2_glock_put_nolock(gl);
1394 spin_unlock(&gl->gl_spin);
1395 spin_lock(&lru_lock);
1399 list_add(&gl->gl_lru, &skipped);
1401 list_splice(&skipped, &lru_list);
1402 atomic_add(nr_skipped, &lru_count);
1403 spin_unlock(&lru_lock);
1405 return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
1408 static struct shrinker glock_shrinker = {
1409 .shrink = gfs2_shrink_glock_memory,
1410 .seeks = DEFAULT_SEEKS,
1414 * examine_bucket - Call a function for glock in a hash bucket
1415 * @examiner: the function
1416 * @sdp: the filesystem
1417 * @bucket: the bucket
1419 * Returns: 1 if the bucket has entries
1422 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
1425 struct gfs2_glock *gl, *prev = NULL;
1426 int has_entries = 0;
1427 struct hlist_head *head = &gl_hash_table[hash].hb_list;
1429 read_lock(gl_lock_addr(hash));
1430 /* Can't use hlist_for_each_entry - don't want prefetch here */
1431 if (hlist_empty(head))
1433 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1435 if (!sdp || gl->gl_sbd == sdp) {
1436 gfs2_glock_hold(gl);
1437 read_unlock(gl_lock_addr(hash));
1439 gfs2_glock_put(prev);
1443 read_lock(gl_lock_addr(hash));
1445 if (gl->gl_list.next == NULL)
1447 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
1450 read_unlock(gl_lock_addr(hash));
1452 gfs2_glock_put(prev);
1459 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1460 * @gl: The glock to thaw
1462 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1463 * so this has to result in the ref count being dropped by one.
1466 static void thaw_glock(struct gfs2_glock *gl)
1468 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1470 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1471 gfs2_glock_hold(gl);
1472 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1477 * clear_glock - look at a glock and see if we can free it from glock cache
1478 * @gl: the glock to look at
1482 static void clear_glock(struct gfs2_glock *gl)
1484 spin_lock(&lru_lock);
1485 if (!list_empty(&gl->gl_lru)) {
1486 list_del_init(&gl->gl_lru);
1487 atomic_dec(&lru_count);
1489 spin_unlock(&lru_lock);
1491 spin_lock(&gl->gl_spin);
1492 if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
1493 handle_callback(gl, LM_ST_UNLOCKED, 0);
1494 spin_unlock(&gl->gl_spin);
1495 gfs2_glock_hold(gl);
1496 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1501 * gfs2_glock_thaw - Thaw any frozen glocks
1502 * @sdp: The super block
1506 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1510 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1511 examine_bucket(thaw_glock, sdp, x);
1515 * gfs2_gl_hash_clear - Empty out the glock hash table
1516 * @sdp: the filesystem
1517 * @wait: wait until it's all gone
1519 * Called when unmounting the filesystem.
1522 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1526 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1527 examine_bucket(clear_glock, sdp, x);
1528 flush_workqueue(glock_workqueue);
1529 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1530 gfs2_dump_lockstate(sdp);
1533 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1535 struct gfs2_glock *gl = ip->i_gl;
1538 ret = gfs2_truncatei_resume(ip);
1539 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1541 spin_lock(&gl->gl_spin);
1542 clear_bit(GLF_LOCK, &gl->gl_flags);
1544 spin_unlock(&gl->gl_spin);
1547 static const char *state2str(unsigned state)
1550 case LM_ST_UNLOCKED:
1554 case LM_ST_DEFERRED:
1556 case LM_ST_EXCLUSIVE:
1562 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1565 if (flags & LM_FLAG_TRY)
1567 if (flags & LM_FLAG_TRY_1CB)
1569 if (flags & LM_FLAG_NOEXP)
1571 if (flags & LM_FLAG_ANY)
1573 if (flags & LM_FLAG_PRIORITY)
1575 if (flags & GL_ASYNC)
1577 if (flags & GL_EXACT)
1579 if (flags & GL_NOCACHE)
1581 if (test_bit(HIF_HOLDER, &iflags))
1583 if (test_bit(HIF_WAIT, &iflags))
1585 if (test_bit(HIF_FIRST, &iflags))
1592 * dump_holder - print information about a glock holder
1593 * @seq: the seq_file struct
1594 * @gh: the glock holder
1596 * Returns: 0 on success, -ENOBUFS when we run out of space
1599 static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1601 struct task_struct *gh_owner = NULL;
1602 char buffer[KSYM_SYMBOL_LEN];
1605 sprint_symbol(buffer, gh->gh_ip);
1606 if (gh->gh_owner_pid)
1607 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1608 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
1609 state2str(gh->gh_state),
1610 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1612 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1613 gh_owner ? gh_owner->comm : "(ended)", buffer);
1617 static const char *gflags2str(char *buf, const unsigned long *gflags)
1620 if (test_bit(GLF_LOCK, gflags))
1622 if (test_bit(GLF_DEMOTE, gflags))
1624 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1626 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1628 if (test_bit(GLF_DIRTY, gflags))
1630 if (test_bit(GLF_LFLUSH, gflags))
1632 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1634 if (test_bit(GLF_REPLY_PENDING, gflags))
1636 if (test_bit(GLF_INITIAL, gflags))
1638 if (test_bit(GLF_FROZEN, gflags))
1645 * __dump_glock - print information about a glock
1646 * @seq: The seq_file struct
1649 * The file format is as follows:
1650 * One line per object, capital letters are used to indicate objects
1651 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1652 * other objects are indented by a single space and follow the glock to
1653 * which they are related. Fields are indicated by lower case letters
1654 * followed by a colon and the field value, except for strings which are in
1655 * [] so that its possible to see if they are composed of spaces for
1656 * example. The field's are n = number (id of the object), f = flags,
1657 * t = type, s = state, r = refcount, e = error, p = pid.
1659 * Returns: 0 on success, -ENOBUFS when we run out of space
1662 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1664 const struct gfs2_glock_operations *glops = gl->gl_ops;
1665 unsigned long long dtime;
1666 const struct gfs2_holder *gh;
1667 char gflags_buf[32];
1670 dtime = jiffies - gl->gl_demote_time;
1671 dtime *= 1000000/HZ; /* demote time in uSec */
1672 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1674 gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d r:%d\n",
1675 state2str(gl->gl_state),
1676 gl->gl_name.ln_type,
1677 (unsigned long long)gl->gl_name.ln_number,
1678 gflags2str(gflags_buf, &gl->gl_flags),
1679 state2str(gl->gl_target),
1680 state2str(gl->gl_demote_state), dtime,
1681 atomic_read(&gl->gl_ail_count),
1682 atomic_read(&gl->gl_ref));
1684 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1685 error = dump_holder(seq, gh);
1689 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1690 error = glops->go_dump(seq, gl);
1695 static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1698 spin_lock(&gl->gl_spin);
1699 ret = __dump_glock(seq, gl);
1700 spin_unlock(&gl->gl_spin);
1705 * gfs2_dump_lockstate - print out the current lockstate
1706 * @sdp: the filesystem
1707 * @ub: the buffer to copy the information into
1709 * If @ub is NULL, dump the lockstate to the console.
1713 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
1715 struct gfs2_glock *gl;
1716 struct hlist_node *h;
1720 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1722 read_lock(gl_lock_addr(x));
1724 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
1725 if (gl->gl_sbd != sdp)
1728 error = dump_glock(NULL, gl);
1733 read_unlock(gl_lock_addr(x));
1744 int __init gfs2_glock_init(void)
1747 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1748 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
1750 #ifdef GL_HASH_LOCK_SZ
1751 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1752 rwlock_init(&gl_hash_locks[i]);
1756 glock_workqueue = create_workqueue("glock_workqueue");
1757 if (IS_ERR(glock_workqueue))
1758 return PTR_ERR(glock_workqueue);
1759 gfs2_delete_workqueue = create_workqueue("delete_workqueue");
1760 if (IS_ERR(gfs2_delete_workqueue)) {
1761 destroy_workqueue(glock_workqueue);
1762 return PTR_ERR(gfs2_delete_workqueue);
1765 register_shrinker(&glock_shrinker);
1770 void gfs2_glock_exit(void)
1772 unregister_shrinker(&glock_shrinker);
1773 destroy_workqueue(glock_workqueue);
1774 destroy_workqueue(gfs2_delete_workqueue);
1777 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1779 struct gfs2_glock *gl;
1782 read_lock(gl_lock_addr(gi->hash));
1785 gi->gl = hlist_entry(gl->gl_list.next,
1786 struct gfs2_glock, gl_list);
1788 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1789 struct gfs2_glock, gl_list);
1792 gfs2_glock_hold(gi->gl);
1793 read_unlock(gl_lock_addr(gi->hash));
1796 while (gi->gl == NULL) {
1798 if (gi->hash >= GFS2_GL_HASH_SIZE)
1800 read_lock(gl_lock_addr(gi->hash));
1801 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1802 struct gfs2_glock, gl_list);
1804 gfs2_glock_hold(gi->gl);
1805 read_unlock(gl_lock_addr(gi->hash));
1808 if (gi->sdp != gi->gl->gl_sbd)
1814 static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
1817 gfs2_glock_put(gi->gl);
1821 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1823 struct gfs2_glock_iter *gi = seq->private;
1829 if (gfs2_glock_iter_next(gi)) {
1830 gfs2_glock_iter_free(gi);
1838 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1841 struct gfs2_glock_iter *gi = seq->private;
1845 if (gfs2_glock_iter_next(gi)) {
1846 gfs2_glock_iter_free(gi);
1853 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1855 struct gfs2_glock_iter *gi = seq->private;
1856 gfs2_glock_iter_free(gi);
1859 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1861 return dump_glock(seq, iter_ptr);
1864 static const struct seq_operations gfs2_glock_seq_ops = {
1865 .start = gfs2_glock_seq_start,
1866 .next = gfs2_glock_seq_next,
1867 .stop = gfs2_glock_seq_stop,
1868 .show = gfs2_glock_seq_show,
1871 static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1873 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1874 sizeof(struct gfs2_glock_iter));
1876 struct seq_file *seq = file->private_data;
1877 struct gfs2_glock_iter *gi = seq->private;
1878 gi->sdp = inode->i_private;
1883 static const struct file_operations gfs2_debug_fops = {
1884 .owner = THIS_MODULE,
1885 .open = gfs2_debugfs_open,
1887 .llseek = seq_lseek,
1888 .release = seq_release_private,
1891 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1893 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1894 if (!sdp->debugfs_dir)
1896 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1898 sdp->debugfs_dir, sdp,
1900 if (!sdp->debugfs_dentry_glocks)
1906 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1908 if (sdp && sdp->debugfs_dir) {
1909 if (sdp->debugfs_dentry_glocks) {
1910 debugfs_remove(sdp->debugfs_dentry_glocks);
1911 sdp->debugfs_dentry_glocks = NULL;
1913 debugfs_remove(sdp->debugfs_dir);
1914 sdp->debugfs_dir = NULL;
1918 int gfs2_register_debugfs(void)
1920 gfs2_root = debugfs_create_dir("gfs2", NULL);
1921 return gfs2_root ? 0 : -ENOMEM;
1924 void gfs2_unregister_debugfs(void)
1926 debugfs_remove(gfs2_root);