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_error - Something unexpected has happened during a lock request
335 static inline void do_error(struct gfs2_glock *gl, const int ret)
337 struct gfs2_holder *gh, *tmp;
339 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
340 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
342 if (ret & LM_OUT_ERROR)
344 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
345 gh->gh_error = GLR_TRYFAILED;
348 list_del_init(&gh->gh_list);
349 trace_gfs2_glock_queue(gh, 0);
350 gfs2_holder_wake(gh);
355 * do_promote - promote as many requests as possible on the current queue
358 * Returns: 1 if there is a blocked holder at the head of the list, or 2
359 * if a type specific operation is underway.
362 static int do_promote(struct gfs2_glock *gl)
363 __releases(&gl->gl_spin)
364 __acquires(&gl->gl_spin)
366 const struct gfs2_glock_operations *glops = gl->gl_ops;
367 struct gfs2_holder *gh, *tmp;
371 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
372 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
374 if (may_grant(gl, gh)) {
375 if (gh->gh_list.prev == &gl->gl_holders &&
377 spin_unlock(&gl->gl_spin);
378 /* FIXME: eliminate this eventually */
379 ret = glops->go_lock(gh);
380 spin_lock(&gl->gl_spin);
385 list_del_init(&gh->gh_list);
386 trace_gfs2_glock_queue(gh, 0);
387 gfs2_holder_wake(gh);
390 set_bit(HIF_HOLDER, &gh->gh_iflags);
391 trace_gfs2_promote(gh, 1);
392 gfs2_holder_wake(gh);
395 set_bit(HIF_HOLDER, &gh->gh_iflags);
396 trace_gfs2_promote(gh, 0);
397 gfs2_holder_wake(gh);
400 if (gh->gh_list.prev == &gl->gl_holders)
409 * find_first_waiter - find the first gh that's waiting for the glock
413 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
415 struct gfs2_holder *gh;
417 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
418 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
425 * state_change - record that the glock is now in a different state
427 * @new_state the new state
431 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
435 held1 = (gl->gl_state != LM_ST_UNLOCKED);
436 held2 = (new_state != LM_ST_UNLOCKED);
438 if (held1 != held2) {
442 gfs2_glock_put_nolock(gl);
444 if (held1 && held2 && list_empty(&gl->gl_holders))
445 clear_bit(GLF_QUEUED, &gl->gl_flags);
447 gl->gl_state = new_state;
448 gl->gl_tchange = jiffies;
451 static void gfs2_demote_wake(struct gfs2_glock *gl)
453 gl->gl_demote_state = LM_ST_EXCLUSIVE;
454 clear_bit(GLF_DEMOTE, &gl->gl_flags);
455 smp_mb__after_clear_bit();
456 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
460 * finish_xmote - The DLM has replied to one of our lock requests
462 * @ret: The status from the DLM
466 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
468 const struct gfs2_glock_operations *glops = gl->gl_ops;
469 struct gfs2_holder *gh;
470 unsigned state = ret & LM_OUT_ST_MASK;
473 spin_lock(&gl->gl_spin);
474 trace_gfs2_glock_state_change(gl, state);
475 state_change(gl, state);
476 gh = find_first_waiter(gl);
478 /* Demote to UN request arrived during demote to SH or DF */
479 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
480 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
481 gl->gl_target = LM_ST_UNLOCKED;
483 /* Check for state != intended state */
484 if (unlikely(state != gl->gl_target)) {
485 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
486 /* move to back of queue and try next entry */
487 if (ret & LM_OUT_CANCELED) {
488 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
489 list_move_tail(&gh->gh_list, &gl->gl_holders);
490 gh = find_first_waiter(gl);
491 gl->gl_target = gh->gh_state;
494 /* Some error or failed "try lock" - report it */
495 if ((ret & LM_OUT_ERROR) ||
496 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
497 gl->gl_target = gl->gl_state;
503 /* Unlocked due to conversion deadlock, try again */
506 do_xmote(gl, gh, gl->gl_target);
508 /* Conversion fails, unlock and try again */
511 do_xmote(gl, gh, LM_ST_UNLOCKED);
513 default: /* Everything else */
514 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
517 spin_unlock(&gl->gl_spin);
521 /* Fast path - we got what we asked for */
522 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
523 gfs2_demote_wake(gl);
524 if (state != LM_ST_UNLOCKED) {
525 if (glops->go_xmote_bh) {
526 spin_unlock(&gl->gl_spin);
527 rv = glops->go_xmote_bh(gl, gh);
528 spin_lock(&gl->gl_spin);
539 clear_bit(GLF_LOCK, &gl->gl_flags);
541 spin_unlock(&gl->gl_spin);
544 static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
545 unsigned int req_state,
548 int ret = LM_OUT_ERROR;
550 if (!sdp->sd_lockstruct.ls_ops->lm_lock)
551 return req_state == LM_ST_UNLOCKED ? 0 : req_state;
553 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
554 ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock,
560 * do_xmote - Calls the DLM to change the state of a lock
561 * @gl: The lock state
562 * @gh: The holder (only for promotes)
563 * @target: The target lock state
567 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
568 __releases(&gl->gl_spin)
569 __acquires(&gl->gl_spin)
571 const struct gfs2_glock_operations *glops = gl->gl_ops;
572 struct gfs2_sbd *sdp = gl->gl_sbd;
573 unsigned int lck_flags = gh ? gh->gh_flags : 0;
576 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
578 BUG_ON(gl->gl_state == target);
579 BUG_ON(gl->gl_state == gl->gl_target);
580 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
582 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
583 do_error(gl, 0); /* Fail queued try locks */
585 spin_unlock(&gl->gl_spin);
586 if (glops->go_xmote_th)
587 glops->go_xmote_th(gl);
588 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
589 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
590 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
593 if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
594 gl->gl_state == LM_ST_DEFERRED) &&
595 !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
596 lck_flags |= LM_FLAG_TRY_1CB;
597 ret = gfs2_lm_lock(sdp, gl, target, lck_flags);
599 if (!(ret & LM_OUT_ASYNC)) {
600 finish_xmote(gl, ret);
601 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
604 GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
606 spin_lock(&gl->gl_spin);
610 * find_first_holder - find the first "holder" gh
614 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
616 struct gfs2_holder *gh;
618 if (!list_empty(&gl->gl_holders)) {
619 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
620 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
627 * run_queue - do all outstanding tasks related to a glock
628 * @gl: The glock in question
629 * @nonblock: True if we must not block in run_queue
633 static void run_queue(struct gfs2_glock *gl, const int nonblock)
634 __releases(&gl->gl_spin)
635 __acquires(&gl->gl_spin)
637 struct gfs2_holder *gh = NULL;
640 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
643 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
645 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
646 gl->gl_demote_state != gl->gl_state) {
647 if (find_first_holder(gl))
651 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
652 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
653 gl->gl_target = gl->gl_demote_state;
655 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
656 gfs2_demote_wake(gl);
657 ret = do_promote(gl);
662 gh = find_first_waiter(gl);
663 gl->gl_target = gh->gh_state;
664 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
665 do_error(gl, 0); /* Fail queued try locks */
667 do_xmote(gl, gh, gl->gl_target);
672 clear_bit(GLF_LOCK, &gl->gl_flags);
673 smp_mb__after_clear_bit();
675 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
676 gfs2_glock_put_nolock(gl);
680 clear_bit(GLF_LOCK, &gl->gl_flags);
681 smp_mb__after_clear_bit();
685 static void delete_work_func(struct work_struct *work)
687 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
688 struct gfs2_sbd *sdp = gl->gl_sbd;
689 struct gfs2_inode *ip = NULL;
693 spin_lock(&gl->gl_spin);
694 ip = (struct gfs2_inode *)gl->gl_object;
696 no_addr = ip->i_no_addr;
697 spin_unlock(&gl->gl_spin);
699 inode = gfs2_ilookup(sdp->sd_vfs, no_addr);
701 d_prune_aliases(inode);
708 static void glock_work_func(struct work_struct *work)
710 unsigned long delay = 0;
711 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
714 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
715 finish_xmote(gl, gl->gl_reply);
718 spin_lock(&gl->gl_spin);
719 if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
720 gl->gl_state != LM_ST_UNLOCKED &&
721 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
722 unsigned long holdtime, now = jiffies;
723 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
724 if (time_before(now, holdtime))
725 delay = holdtime - now;
726 set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags);
729 spin_unlock(&gl->gl_spin);
731 queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
738 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
739 * @sdp: The GFS2 superblock
740 * @number: the lock number
741 * @glops: The glock_operations to use
742 * @create: If 0, don't create the glock if it doesn't exist
743 * @glp: the glock is returned here
745 * This does not lock a glock, just finds/creates structures for one.
750 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
751 const struct gfs2_glock_operations *glops, int create,
752 struct gfs2_glock **glp)
754 struct super_block *s = sdp->sd_vfs;
755 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
756 struct gfs2_glock *gl, *tmp;
757 unsigned int hash = gl_hash(sdp, &name);
758 struct address_space *mapping;
760 read_lock(gl_lock_addr(hash));
761 gl = search_bucket(hash, sdp, &name);
762 read_unlock(gl_lock_addr(hash));
770 if (glops->go_flags & GLOF_ASPACE)
771 gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL);
773 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
777 atomic_inc(&sdp->sd_glock_disposal);
780 atomic_set(&gl->gl_ref, 1);
781 gl->gl_state = LM_ST_UNLOCKED;
782 gl->gl_target = LM_ST_UNLOCKED;
783 gl->gl_demote_state = LM_ST_EXCLUSIVE;
786 snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number);
787 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
788 gl->gl_lksb.sb_lvbptr = gl->gl_lvb;
789 gl->gl_tchange = jiffies;
790 gl->gl_object = NULL;
792 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
793 INIT_WORK(&gl->gl_delete, delete_work_func);
795 mapping = gfs2_glock2aspace(gl);
797 mapping->a_ops = &gfs2_meta_aops;
798 mapping->host = s->s_bdev->bd_inode;
800 mapping_set_gfp_mask(mapping, GFP_NOFS);
801 mapping->assoc_mapping = NULL;
802 mapping->backing_dev_info = s->s_bdi;
803 mapping->writeback_index = 0;
806 write_lock(gl_lock_addr(hash));
807 tmp = search_bucket(hash, sdp, &name);
809 write_unlock(gl_lock_addr(hash));
813 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
814 write_unlock(gl_lock_addr(hash));
823 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
825 * @state: the state we're requesting
826 * @flags: the modifier flags
827 * @gh: the holder structure
831 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
832 struct gfs2_holder *gh)
834 INIT_LIST_HEAD(&gh->gh_list);
836 gh->gh_ip = (unsigned long)__builtin_return_address(0);
837 gh->gh_owner_pid = get_pid(task_pid(current));
838 gh->gh_state = state;
839 gh->gh_flags = flags;
846 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
847 * @state: the state we're requesting
848 * @flags: the modifier flags
849 * @gh: the holder structure
851 * Don't mess with the glock.
855 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
857 gh->gh_state = state;
858 gh->gh_flags = flags;
860 gh->gh_ip = (unsigned long)__builtin_return_address(0);
861 if (gh->gh_owner_pid)
862 put_pid(gh->gh_owner_pid);
863 gh->gh_owner_pid = get_pid(task_pid(current));
867 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
868 * @gh: the holder structure
872 void gfs2_holder_uninit(struct gfs2_holder *gh)
874 put_pid(gh->gh_owner_pid);
875 gfs2_glock_put(gh->gh_gl);
881 * gfs2_glock_holder_wait
884 * This function and gfs2_glock_demote_wait both show up in the WCHAN
885 * field. Thus I've separated these otherwise identical functions in
886 * order to be more informative to the user.
889 static int gfs2_glock_holder_wait(void *word)
895 static int gfs2_glock_demote_wait(void *word)
901 static void wait_on_holder(struct gfs2_holder *gh)
904 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
907 static void wait_on_demote(struct gfs2_glock *gl)
910 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
914 * handle_callback - process a demote request
916 * @state: the state the caller wants us to change to
918 * There are only two requests that we are going to see in actual
919 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
922 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
925 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
927 set_bit(bit, &gl->gl_flags);
928 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
929 gl->gl_demote_state = state;
930 gl->gl_demote_time = jiffies;
931 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
932 gl->gl_demote_state != state) {
933 gl->gl_demote_state = LM_ST_UNLOCKED;
935 if (gl->gl_ops->go_callback)
936 gl->gl_ops->go_callback(gl);
937 trace_gfs2_demote_rq(gl);
941 * gfs2_glock_wait - wait on a glock acquisition
942 * @gh: the glock holder
944 * Returns: 0 on success
947 int gfs2_glock_wait(struct gfs2_holder *gh)
953 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
959 struct gfs2_glock_iter *gi = seq->private;
960 vsprintf(gi->string, fmt, args);
961 seq_printf(seq, gi->string);
963 printk(KERN_ERR " ");
970 * add_to_queue - Add a holder to the wait queue (but look for recursion)
971 * @gh: the holder structure to add
973 * Eventually we should move the recursive locking trap to a
974 * debugging option or something like that. This is the fast
975 * path and needs to have the minimum number of distractions.
979 static inline void add_to_queue(struct gfs2_holder *gh)
980 __releases(&gl->gl_spin)
981 __acquires(&gl->gl_spin)
983 struct gfs2_glock *gl = gh->gh_gl;
984 struct gfs2_sbd *sdp = gl->gl_sbd;
985 struct list_head *insert_pt = NULL;
986 struct gfs2_holder *gh2;
989 BUG_ON(gh->gh_owner_pid == NULL);
990 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
993 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
994 if (test_bit(GLF_LOCK, &gl->gl_flags))
996 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
1000 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
1001 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
1002 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
1003 goto trap_recursive;
1005 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
1006 !may_grant(gl, gh)) {
1008 gh->gh_error = GLR_TRYFAILED;
1009 gfs2_holder_wake(gh);
1012 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
1014 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
1015 insert_pt = &gh2->gh_list;
1017 set_bit(GLF_QUEUED, &gl->gl_flags);
1018 if (likely(insert_pt == NULL)) {
1019 list_add_tail(&gh->gh_list, &gl->gl_holders);
1020 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1024 trace_gfs2_glock_queue(gh, 1);
1025 list_add_tail(&gh->gh_list, insert_pt);
1027 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1028 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1029 spin_unlock(&gl->gl_spin);
1030 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1031 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1032 spin_lock(&gl->gl_spin);
1037 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
1038 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1039 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1040 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1041 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
1042 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
1043 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1044 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1045 __dump_glock(NULL, gl);
1050 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1051 * @gh: the holder structure
1053 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1055 * Returns: 0, GLR_TRYFAILED, or errno on failure
1058 int gfs2_glock_nq(struct gfs2_holder *gh)
1060 struct gfs2_glock *gl = gh->gh_gl;
1061 struct gfs2_sbd *sdp = gl->gl_sbd;
1064 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1067 spin_lock(&gl->gl_spin);
1069 if ((LM_FLAG_NOEXP & gh->gh_flags) &&
1070 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1071 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1073 spin_unlock(&gl->gl_spin);
1075 if (!(gh->gh_flags & GL_ASYNC))
1076 error = gfs2_glock_wait(gh);
1082 * gfs2_glock_poll - poll to see if an async request has been completed
1085 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1088 int gfs2_glock_poll(struct gfs2_holder *gh)
1090 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1094 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1095 * @gh: the glock holder
1099 void gfs2_glock_dq(struct gfs2_holder *gh)
1101 struct gfs2_glock *gl = gh->gh_gl;
1102 const struct gfs2_glock_operations *glops = gl->gl_ops;
1106 spin_lock(&gl->gl_spin);
1107 if (gh->gh_flags & GL_NOCACHE)
1108 handle_callback(gl, LM_ST_UNLOCKED, 0);
1110 list_del_init(&gh->gh_list);
1111 if (find_first_holder(gl) == NULL) {
1112 if (glops->go_unlock) {
1113 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1114 spin_unlock(&gl->gl_spin);
1115 glops->go_unlock(gh);
1116 spin_lock(&gl->gl_spin);
1117 clear_bit(GLF_LOCK, &gl->gl_flags);
1119 if (list_empty(&gl->gl_holders) &&
1120 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1121 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1124 trace_gfs2_glock_queue(gh, 0);
1125 spin_unlock(&gl->gl_spin);
1126 if (likely(fast_path))
1129 gfs2_glock_hold(gl);
1130 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1131 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1132 delay = gl->gl_ops->go_min_hold_time;
1133 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1137 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1139 struct gfs2_glock *gl = gh->gh_gl;
1145 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1146 * @gh: the holder structure
1150 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1153 gfs2_holder_uninit(gh);
1157 * gfs2_glock_nq_num - acquire a glock based on lock number
1158 * @sdp: the filesystem
1159 * @number: the lock number
1160 * @glops: the glock operations for the type of glock
1161 * @state: the state to acquire the glock in
1162 * @flags: modifier flags for the aquisition
1163 * @gh: the struct gfs2_holder
1168 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1169 const struct gfs2_glock_operations *glops,
1170 unsigned int state, int flags, struct gfs2_holder *gh)
1172 struct gfs2_glock *gl;
1175 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1177 error = gfs2_glock_nq_init(gl, state, flags, gh);
1185 * glock_compare - Compare two struct gfs2_glock structures for sorting
1186 * @arg_a: the first structure
1187 * @arg_b: the second structure
1191 static int glock_compare(const void *arg_a, const void *arg_b)
1193 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1194 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1195 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1196 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1198 if (a->ln_number > b->ln_number)
1200 if (a->ln_number < b->ln_number)
1202 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1207 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1208 * @num_gh: the number of structures
1209 * @ghs: an array of struct gfs2_holder structures
1211 * Returns: 0 on success (all glocks acquired),
1212 * errno on failure (no glocks acquired)
1215 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1216 struct gfs2_holder **p)
1221 for (x = 0; x < num_gh; x++)
1224 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1226 for (x = 0; x < num_gh; x++) {
1227 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1229 error = gfs2_glock_nq(p[x]);
1232 gfs2_glock_dq(p[x]);
1241 * gfs2_glock_nq_m - acquire multiple glocks
1242 * @num_gh: the number of structures
1243 * @ghs: an array of struct gfs2_holder structures
1246 * Returns: 0 on success (all glocks acquired),
1247 * errno on failure (no glocks acquired)
1250 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1252 struct gfs2_holder *tmp[4];
1253 struct gfs2_holder **pph = tmp;
1260 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1261 return gfs2_glock_nq(ghs);
1265 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1270 error = nq_m_sync(num_gh, ghs, pph);
1279 * gfs2_glock_dq_m - release multiple glocks
1280 * @num_gh: the number of structures
1281 * @ghs: an array of struct gfs2_holder structures
1285 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1289 for (x = 0; x < num_gh; x++)
1290 gfs2_glock_dq(&ghs[x]);
1294 * gfs2_glock_dq_uninit_m - release multiple glocks
1295 * @num_gh: the number of structures
1296 * @ghs: an array of struct gfs2_holder structures
1300 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1304 for (x = 0; x < num_gh; x++)
1305 gfs2_glock_dq_uninit(&ghs[x]);
1308 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1310 unsigned long delay = 0;
1311 unsigned long holdtime;
1312 unsigned long now = jiffies;
1314 gfs2_glock_hold(gl);
1315 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
1316 if (test_bit(GLF_QUEUED, &gl->gl_flags)) {
1317 if (time_before(now, holdtime))
1318 delay = holdtime - now;
1319 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1320 delay = gl->gl_ops->go_min_hold_time;
1323 spin_lock(&gl->gl_spin);
1324 handle_callback(gl, state, delay);
1325 spin_unlock(&gl->gl_spin);
1326 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1331 * gfs2_should_freeze - Figure out if glock should be frozen
1332 * @gl: The glock in question
1334 * Glocks are not frozen if (a) the result of the dlm operation is
1335 * an error, (b) the locking operation was an unlock operation or
1336 * (c) if there is a "noexp" flagged request anywhere in the queue
1338 * Returns: 1 if freezing should occur, 0 otherwise
1341 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1343 const struct gfs2_holder *gh;
1345 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1347 if (gl->gl_target == LM_ST_UNLOCKED)
1350 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1351 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1353 if (LM_FLAG_NOEXP & gh->gh_flags)
1361 * gfs2_glock_complete - Callback used by locking
1362 * @gl: Pointer to the glock
1363 * @ret: The return value from the dlm
1367 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1369 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1373 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) {
1374 spin_lock(&gl->gl_spin);
1375 if (gfs2_should_freeze(gl)) {
1376 set_bit(GLF_FROZEN, &gl->gl_flags);
1377 spin_unlock(&gl->gl_spin);
1380 spin_unlock(&gl->gl_spin);
1382 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1383 gfs2_glock_hold(gl);
1384 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1389 static int gfs2_shrink_glock_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
1391 struct gfs2_glock *gl;
1399 if (!(gfp_mask & __GFP_FS))
1402 spin_lock(&lru_lock);
1403 while(nr && !list_empty(&lru_list)) {
1404 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1405 list_del_init(&gl->gl_lru);
1406 atomic_dec(&lru_count);
1408 /* Test for being demotable */
1409 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1410 gfs2_glock_hold(gl);
1411 spin_unlock(&lru_lock);
1412 spin_lock(&gl->gl_spin);
1413 may_demote = demote_ok(gl);
1415 handle_callback(gl, LM_ST_UNLOCKED, 0);
1418 clear_bit(GLF_LOCK, &gl->gl_flags);
1419 smp_mb__after_clear_bit();
1420 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1421 gfs2_glock_put_nolock(gl);
1422 spin_unlock(&gl->gl_spin);
1423 spin_lock(&lru_lock);
1427 list_add(&gl->gl_lru, &skipped);
1429 list_splice(&skipped, &lru_list);
1430 atomic_add(nr_skipped, &lru_count);
1431 spin_unlock(&lru_lock);
1433 return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
1436 static struct shrinker glock_shrinker = {
1437 .shrink = gfs2_shrink_glock_memory,
1438 .seeks = DEFAULT_SEEKS,
1442 * examine_bucket - Call a function for glock in a hash bucket
1443 * @examiner: the function
1444 * @sdp: the filesystem
1445 * @bucket: the bucket
1447 * Returns: 1 if the bucket has entries
1450 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
1453 struct gfs2_glock *gl, *prev = NULL;
1454 int has_entries = 0;
1455 struct hlist_head *head = &gl_hash_table[hash].hb_list;
1457 read_lock(gl_lock_addr(hash));
1458 /* Can't use hlist_for_each_entry - don't want prefetch here */
1459 if (hlist_empty(head))
1461 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1463 if (!sdp || gl->gl_sbd == sdp) {
1464 gfs2_glock_hold(gl);
1465 read_unlock(gl_lock_addr(hash));
1467 gfs2_glock_put(prev);
1471 read_lock(gl_lock_addr(hash));
1473 if (gl->gl_list.next == NULL)
1475 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
1478 read_unlock(gl_lock_addr(hash));
1480 gfs2_glock_put(prev);
1487 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1488 * @gl: The glock to thaw
1490 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1491 * so this has to result in the ref count being dropped by one.
1494 static void thaw_glock(struct gfs2_glock *gl)
1496 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1498 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1499 gfs2_glock_hold(gl);
1500 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1505 * clear_glock - look at a glock and see if we can free it from glock cache
1506 * @gl: the glock to look at
1510 static void clear_glock(struct gfs2_glock *gl)
1512 spin_lock(&lru_lock);
1513 if (!list_empty(&gl->gl_lru)) {
1514 list_del_init(&gl->gl_lru);
1515 atomic_dec(&lru_count);
1517 spin_unlock(&lru_lock);
1519 spin_lock(&gl->gl_spin);
1520 if (gl->gl_state != LM_ST_UNLOCKED)
1521 handle_callback(gl, LM_ST_UNLOCKED, 0);
1522 spin_unlock(&gl->gl_spin);
1523 gfs2_glock_hold(gl);
1524 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1529 * gfs2_glock_thaw - Thaw any frozen glocks
1530 * @sdp: The super block
1534 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1538 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1539 examine_bucket(thaw_glock, sdp, x);
1543 * gfs2_gl_hash_clear - Empty out the glock hash table
1544 * @sdp: the filesystem
1545 * @wait: wait until it's all gone
1547 * Called when unmounting the filesystem.
1550 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1554 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1555 examine_bucket(clear_glock, sdp, x);
1556 flush_workqueue(glock_workqueue);
1557 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1558 gfs2_dump_lockstate(sdp);
1561 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1563 struct gfs2_glock *gl = ip->i_gl;
1566 ret = gfs2_truncatei_resume(ip);
1567 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1569 spin_lock(&gl->gl_spin);
1570 clear_bit(GLF_LOCK, &gl->gl_flags);
1572 spin_unlock(&gl->gl_spin);
1575 static const char *state2str(unsigned state)
1578 case LM_ST_UNLOCKED:
1582 case LM_ST_DEFERRED:
1584 case LM_ST_EXCLUSIVE:
1590 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1593 if (flags & LM_FLAG_TRY)
1595 if (flags & LM_FLAG_TRY_1CB)
1597 if (flags & LM_FLAG_NOEXP)
1599 if (flags & LM_FLAG_ANY)
1601 if (flags & LM_FLAG_PRIORITY)
1603 if (flags & GL_ASYNC)
1605 if (flags & GL_EXACT)
1607 if (flags & GL_NOCACHE)
1609 if (test_bit(HIF_HOLDER, &iflags))
1611 if (test_bit(HIF_WAIT, &iflags))
1613 if (test_bit(HIF_FIRST, &iflags))
1620 * dump_holder - print information about a glock holder
1621 * @seq: the seq_file struct
1622 * @gh: the glock holder
1624 * Returns: 0 on success, -ENOBUFS when we run out of space
1627 static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1629 struct task_struct *gh_owner = NULL;
1630 char buffer[KSYM_SYMBOL_LEN];
1633 sprint_symbol(buffer, gh->gh_ip);
1634 if (gh->gh_owner_pid)
1635 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1636 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
1637 state2str(gh->gh_state),
1638 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1640 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1641 gh_owner ? gh_owner->comm : "(ended)", buffer);
1645 static const char *gflags2str(char *buf, const unsigned long *gflags)
1648 if (test_bit(GLF_LOCK, gflags))
1650 if (test_bit(GLF_DEMOTE, gflags))
1652 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1654 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1656 if (test_bit(GLF_DIRTY, gflags))
1658 if (test_bit(GLF_LFLUSH, gflags))
1660 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1662 if (test_bit(GLF_REPLY_PENDING, gflags))
1664 if (test_bit(GLF_INITIAL, gflags))
1666 if (test_bit(GLF_FROZEN, gflags))
1668 if (test_bit(GLF_QUEUED, gflags))
1675 * __dump_glock - print information about a glock
1676 * @seq: The seq_file struct
1679 * The file format is as follows:
1680 * One line per object, capital letters are used to indicate objects
1681 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1682 * other objects are indented by a single space and follow the glock to
1683 * which they are related. Fields are indicated by lower case letters
1684 * followed by a colon and the field value, except for strings which are in
1685 * [] so that its possible to see if they are composed of spaces for
1686 * example. The field's are n = number (id of the object), f = flags,
1687 * t = type, s = state, r = refcount, e = error, p = pid.
1689 * Returns: 0 on success, -ENOBUFS when we run out of space
1692 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1694 const struct gfs2_glock_operations *glops = gl->gl_ops;
1695 unsigned long long dtime;
1696 const struct gfs2_holder *gh;
1697 char gflags_buf[32];
1700 dtime = jiffies - gl->gl_demote_time;
1701 dtime *= 1000000/HZ; /* demote time in uSec */
1702 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1704 gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d r:%d\n",
1705 state2str(gl->gl_state),
1706 gl->gl_name.ln_type,
1707 (unsigned long long)gl->gl_name.ln_number,
1708 gflags2str(gflags_buf, &gl->gl_flags),
1709 state2str(gl->gl_target),
1710 state2str(gl->gl_demote_state), dtime,
1711 atomic_read(&gl->gl_ail_count),
1712 atomic_read(&gl->gl_ref));
1714 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1715 error = dump_holder(seq, gh);
1719 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1720 error = glops->go_dump(seq, gl);
1725 static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1728 spin_lock(&gl->gl_spin);
1729 ret = __dump_glock(seq, gl);
1730 spin_unlock(&gl->gl_spin);
1735 * gfs2_dump_lockstate - print out the current lockstate
1736 * @sdp: the filesystem
1737 * @ub: the buffer to copy the information into
1739 * If @ub is NULL, dump the lockstate to the console.
1743 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
1745 struct gfs2_glock *gl;
1746 struct hlist_node *h;
1750 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1752 read_lock(gl_lock_addr(x));
1754 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
1755 if (gl->gl_sbd != sdp)
1758 error = dump_glock(NULL, gl);
1763 read_unlock(gl_lock_addr(x));
1774 int __init gfs2_glock_init(void)
1777 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1778 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
1780 #ifdef GL_HASH_LOCK_SZ
1781 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1782 rwlock_init(&gl_hash_locks[i]);
1786 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_RESCUER |
1787 WQ_HIGHPRI | WQ_FREEZEABLE, 0);
1788 if (IS_ERR(glock_workqueue))
1789 return PTR_ERR(glock_workqueue);
1790 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue", WQ_RESCUER |
1792 if (IS_ERR(gfs2_delete_workqueue)) {
1793 destroy_workqueue(glock_workqueue);
1794 return PTR_ERR(gfs2_delete_workqueue);
1797 register_shrinker(&glock_shrinker);
1802 void gfs2_glock_exit(void)
1804 unregister_shrinker(&glock_shrinker);
1805 destroy_workqueue(glock_workqueue);
1806 destroy_workqueue(gfs2_delete_workqueue);
1809 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1811 struct gfs2_glock *gl;
1814 read_lock(gl_lock_addr(gi->hash));
1817 gi->gl = hlist_entry(gl->gl_list.next,
1818 struct gfs2_glock, gl_list);
1820 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1821 struct gfs2_glock, gl_list);
1824 gfs2_glock_hold(gi->gl);
1825 read_unlock(gl_lock_addr(gi->hash));
1828 while (gi->gl == NULL) {
1830 if (gi->hash >= GFS2_GL_HASH_SIZE)
1832 read_lock(gl_lock_addr(gi->hash));
1833 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1834 struct gfs2_glock, gl_list);
1836 gfs2_glock_hold(gi->gl);
1837 read_unlock(gl_lock_addr(gi->hash));
1840 if (gi->sdp != gi->gl->gl_sbd)
1846 static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
1849 gfs2_glock_put(gi->gl);
1853 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1855 struct gfs2_glock_iter *gi = seq->private;
1861 if (gfs2_glock_iter_next(gi)) {
1862 gfs2_glock_iter_free(gi);
1870 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1873 struct gfs2_glock_iter *gi = seq->private;
1877 if (gfs2_glock_iter_next(gi)) {
1878 gfs2_glock_iter_free(gi);
1885 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1887 struct gfs2_glock_iter *gi = seq->private;
1888 gfs2_glock_iter_free(gi);
1891 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1893 return dump_glock(seq, iter_ptr);
1896 static const struct seq_operations gfs2_glock_seq_ops = {
1897 .start = gfs2_glock_seq_start,
1898 .next = gfs2_glock_seq_next,
1899 .stop = gfs2_glock_seq_stop,
1900 .show = gfs2_glock_seq_show,
1903 static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1905 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1906 sizeof(struct gfs2_glock_iter));
1908 struct seq_file *seq = file->private_data;
1909 struct gfs2_glock_iter *gi = seq->private;
1910 gi->sdp = inode->i_private;
1915 static const struct file_operations gfs2_debug_fops = {
1916 .owner = THIS_MODULE,
1917 .open = gfs2_debugfs_open,
1919 .llseek = seq_lseek,
1920 .release = seq_release_private,
1923 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1925 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1926 if (!sdp->debugfs_dir)
1928 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1930 sdp->debugfs_dir, sdp,
1932 if (!sdp->debugfs_dentry_glocks)
1938 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1940 if (sdp && sdp->debugfs_dir) {
1941 if (sdp->debugfs_dentry_glocks) {
1942 debugfs_remove(sdp->debugfs_dentry_glocks);
1943 sdp->debugfs_dentry_glocks = NULL;
1945 debugfs_remove(sdp->debugfs_dir);
1946 sdp->debugfs_dir = NULL;
1950 int gfs2_register_debugfs(void)
1952 gfs2_root = debugfs_create_dir("gfs2", NULL);
1953 return gfs2_root ? 0 : -ENOMEM;
1956 void gfs2_unregister_debugfs(void)
1958 debugfs_remove(gfs2_root);