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/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/delay.h>
16 #include <linux/sort.h>
17 #include <linux/jhash.h>
18 #include <linux/kallsyms.h>
19 #include <linux/gfs2_ondisk.h>
20 #include <linux/list.h>
21 #include <linux/lm_interface.h>
22 #include <linux/wait.h>
23 #include <linux/module.h>
24 #include <linux/rwsem.h>
25 #include <asm/uaccess.h>
26 #include <linux/seq_file.h>
27 #include <linux/debugfs.h>
28 #include <linux/kthread.h>
29 #include <linux/freezer.h>
30 #include <linux/workqueue.h>
31 #include <linux/jiffies.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 DECLARE_RWSEM(gfs2_umount_flush_sem);
63 static struct dentry *gfs2_root;
64 static struct task_struct *scand_process;
65 static unsigned int scand_secs = 5;
66 static struct workqueue_struct *glock_workqueue;
68 #define GFS2_GL_HASH_SHIFT 15
69 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
70 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
72 static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
73 static struct dentry *gfs2_root;
76 * Despite what you might think, the numbers below are not arbitrary :-)
77 * They are taken from the ipv4 routing hash code, which is well tested
78 * and thus should be nearly optimal. Later on we might tweek the numbers
79 * but for now this should be fine.
81 * The reason for putting the locks in a separate array from the list heads
82 * is that we can have fewer locks than list heads and save memory. We use
83 * the same hash function for both, but with a different hash mask.
85 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
86 defined(CONFIG_PROVE_LOCKING)
89 # define GL_HASH_LOCK_SZ 256
92 # define GL_HASH_LOCK_SZ 4096
94 # define GL_HASH_LOCK_SZ 2048
96 # define GL_HASH_LOCK_SZ 1024
98 # define GL_HASH_LOCK_SZ 512
100 # define GL_HASH_LOCK_SZ 256
104 /* We never want more locks than chains */
105 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
106 # undef GL_HASH_LOCK_SZ
107 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
110 static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
112 static inline rwlock_t *gl_lock_addr(unsigned int x)
114 return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
116 #else /* not SMP, so no spinlocks required */
117 static inline rwlock_t *gl_lock_addr(unsigned int x)
124 * gl_hash() - Turn glock number into hash bucket number
125 * @lock: The glock number
127 * Returns: The number of the corresponding hash bucket
130 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
131 const struct lm_lockname *name)
135 h = jhash(&name->ln_number, sizeof(u64), 0);
136 h = jhash(&name->ln_type, sizeof(unsigned int), h);
137 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
138 h &= GFS2_GL_HASH_MASK;
144 * glock_free() - Perform a few checks and then release struct gfs2_glock
145 * @gl: The glock to release
147 * Also calls lock module to release its internal structure for this glock.
151 static void glock_free(struct gfs2_glock *gl)
153 struct gfs2_sbd *sdp = gl->gl_sbd;
154 struct inode *aspace = gl->gl_aspace;
156 if (sdp->sd_lockstruct.ls_ops->lm_put_lock)
157 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl->gl_lock);
160 gfs2_aspace_put(aspace);
162 kmem_cache_free(gfs2_glock_cachep, gl);
166 * gfs2_glock_hold() - increment reference count on glock
167 * @gl: The glock to hold
171 static void gfs2_glock_hold(struct gfs2_glock *gl)
173 atomic_inc(&gl->gl_ref);
177 * gfs2_glock_put() - Decrement reference count on glock
178 * @gl: The glock to put
182 int gfs2_glock_put(struct gfs2_glock *gl)
186 write_lock(gl_lock_addr(gl->gl_hash));
187 if (atomic_dec_and_test(&gl->gl_ref)) {
188 hlist_del(&gl->gl_list);
189 write_unlock(gl_lock_addr(gl->gl_hash));
190 GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_UNLOCKED);
191 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_reclaim));
192 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
197 write_unlock(gl_lock_addr(gl->gl_hash));
203 * search_bucket() - Find struct gfs2_glock by lock number
204 * @bucket: the bucket to search
205 * @name: The lock name
207 * Returns: NULL, or the struct gfs2_glock with the requested number
210 static struct gfs2_glock *search_bucket(unsigned int hash,
211 const struct gfs2_sbd *sdp,
212 const struct lm_lockname *name)
214 struct gfs2_glock *gl;
215 struct hlist_node *h;
217 hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
218 if (!lm_name_equal(&gl->gl_name, name))
220 if (gl->gl_sbd != sdp)
223 atomic_inc(&gl->gl_ref);
232 * gfs2_glock_find() - Find glock by lock number
233 * @sdp: The GFS2 superblock
234 * @name: The lock name
236 * Returns: NULL, or the struct gfs2_glock with the requested number
239 static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
240 const struct lm_lockname *name)
242 unsigned int hash = gl_hash(sdp, name);
243 struct gfs2_glock *gl;
245 read_lock(gl_lock_addr(hash));
246 gl = search_bucket(hash, sdp, name);
247 read_unlock(gl_lock_addr(hash));
253 * may_grant - check if its ok to grant a new lock
255 * @gh: The lock request which we wish to grant
257 * Returns: true if its ok to grant the lock
260 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
262 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
263 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
264 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
266 if (gl->gl_state == gh->gh_state)
268 if (gh->gh_flags & GL_EXACT)
270 if (gh->gh_state == LM_ST_SHARED && gl->gl_state == LM_ST_EXCLUSIVE)
272 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
277 static void gfs2_holder_wake(struct gfs2_holder *gh)
279 clear_bit(HIF_WAIT, &gh->gh_iflags);
280 smp_mb__after_clear_bit();
281 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
285 * do_promote - promote as many requests as possible on the current queue
288 * Returns: true if there is a blocked holder at the head of the list
291 static int do_promote(struct gfs2_glock *gl)
293 const struct gfs2_glock_operations *glops = gl->gl_ops;
294 struct gfs2_holder *gh, *tmp;
298 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
299 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
301 if (may_grant(gl, gh)) {
302 if (gh->gh_list.prev == &gl->gl_holders &&
304 spin_unlock(&gl->gl_spin);
305 /* FIXME: eliminate this eventually */
306 ret = glops->go_lock(gh);
307 spin_lock(&gl->gl_spin);
310 list_del_init(&gh->gh_list);
311 gfs2_holder_wake(gh);
314 set_bit(HIF_HOLDER, &gh->gh_iflags);
315 gfs2_holder_wake(gh);
318 set_bit(HIF_HOLDER, &gh->gh_iflags);
319 gfs2_holder_wake(gh);
322 if (gh->gh_list.prev == &gl->gl_holders)
330 * do_error - Something unexpected has happened during a lock request
334 static inline void do_error(struct gfs2_glock *gl, const int ret)
336 struct gfs2_holder *gh, *tmp;
338 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
339 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
341 if (ret & LM_OUT_ERROR)
343 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
344 gh->gh_error = GLR_TRYFAILED;
347 list_del_init(&gh->gh_list);
348 gfs2_holder_wake(gh);
353 * find_first_waiter - find the first gh that's waiting for the glock
357 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
359 struct gfs2_holder *gh;
361 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
362 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
369 * state_change - record that the glock is now in a different state
371 * @new_state the new state
375 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
379 held1 = (gl->gl_state != LM_ST_UNLOCKED);
380 held2 = (new_state != LM_ST_UNLOCKED);
382 if (held1 != held2) {
389 gl->gl_state = new_state;
390 gl->gl_tchange = jiffies;
393 static void gfs2_demote_wake(struct gfs2_glock *gl)
395 gl->gl_demote_state = LM_ST_EXCLUSIVE;
396 clear_bit(GLF_DEMOTE, &gl->gl_flags);
397 smp_mb__after_clear_bit();
398 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
402 * finish_xmote - The DLM has replied to one of our lock requests
404 * @ret: The status from the DLM
408 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
410 const struct gfs2_glock_operations *glops = gl->gl_ops;
411 struct gfs2_holder *gh;
412 unsigned state = ret & LM_OUT_ST_MASK;
414 spin_lock(&gl->gl_spin);
415 state_change(gl, state);
416 gh = find_first_waiter(gl);
418 /* Demote to UN request arrived during demote to SH or DF */
419 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
420 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
421 gl->gl_target = LM_ST_UNLOCKED;
423 /* Check for state != intended state */
424 if (unlikely(state != gl->gl_target)) {
425 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
426 /* move to back of queue and try next entry */
427 if (ret & LM_OUT_CANCELED) {
428 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
429 list_move_tail(&gh->gh_list, &gl->gl_holders);
430 gh = find_first_waiter(gl);
431 gl->gl_target = gh->gh_state;
434 /* Some error or failed "try lock" - report it */
435 if ((ret & LM_OUT_ERROR) ||
436 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
437 gl->gl_target = gl->gl_state;
443 /* Unlocked due to conversion deadlock, try again */
446 do_xmote(gl, gh, gl->gl_target);
448 /* Conversion fails, unlock and try again */
451 do_xmote(gl, gh, LM_ST_UNLOCKED);
453 default: /* Everything else */
454 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
457 spin_unlock(&gl->gl_spin);
462 /* Fast path - we got what we asked for */
463 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
464 gfs2_demote_wake(gl);
465 if (state != LM_ST_UNLOCKED) {
466 if (glops->go_xmote_bh) {
468 spin_unlock(&gl->gl_spin);
469 rv = glops->go_xmote_bh(gl, gh);
472 spin_lock(&gl->gl_spin);
481 clear_bit(GLF_LOCK, &gl->gl_flags);
482 spin_unlock(&gl->gl_spin);
486 static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
487 unsigned int cur_state, unsigned int req_state,
490 int ret = LM_OUT_ERROR;
492 if (!sdp->sd_lockstruct.ls_ops->lm_lock)
493 return req_state == LM_ST_UNLOCKED ? 0 : req_state;
495 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
496 ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state,
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)
511 const struct gfs2_glock_operations *glops = gl->gl_ops;
512 struct gfs2_sbd *sdp = gl->gl_sbd;
513 unsigned int lck_flags = gh ? gh->gh_flags : 0;
516 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
518 BUG_ON(gl->gl_state == target);
519 BUG_ON(gl->gl_state == gl->gl_target);
520 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
522 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
523 do_error(gl, 0); /* Fail queued try locks */
525 spin_unlock(&gl->gl_spin);
526 if (glops->go_xmote_th)
527 glops->go_xmote_th(gl);
528 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
529 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
530 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
533 if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
534 gl->gl_state == LM_ST_DEFERRED) &&
535 !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
536 lck_flags |= LM_FLAG_TRY_1CB;
537 ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, target, lck_flags);
539 if (!(ret & LM_OUT_ASYNC)) {
540 finish_xmote(gl, ret);
542 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
545 GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
547 spin_lock(&gl->gl_spin);
551 * find_first_holder - find the first "holder" gh
555 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
557 struct gfs2_holder *gh;
559 if (!list_empty(&gl->gl_holders)) {
560 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
561 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
568 * run_queue - do all outstanding tasks related to a glock
569 * @gl: The glock in question
570 * @nonblock: True if we must not block in run_queue
574 static void run_queue(struct gfs2_glock *gl, const int nonblock)
576 struct gfs2_holder *gh = NULL;
578 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
581 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
583 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
584 gl->gl_demote_state != gl->gl_state) {
585 if (find_first_holder(gl))
589 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
590 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
591 gl->gl_target = gl->gl_demote_state;
593 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
594 gfs2_demote_wake(gl);
595 if (do_promote(gl) == 0)
597 gh = find_first_waiter(gl);
598 gl->gl_target = gh->gh_state;
599 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
600 do_error(gl, 0); /* Fail queued try locks */
602 do_xmote(gl, gh, gl->gl_target);
607 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
610 clear_bit(GLF_LOCK, &gl->gl_flags);
613 static void glock_work_func(struct work_struct *work)
615 unsigned long delay = 0;
616 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
618 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags))
619 finish_xmote(gl, gl->gl_reply);
620 spin_lock(&gl->gl_spin);
621 if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
622 gl->gl_state != LM_ST_UNLOCKED &&
623 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
624 unsigned long holdtime, now = jiffies;
625 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
626 if (time_before(now, holdtime))
627 delay = holdtime - now;
628 set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags);
631 spin_unlock(&gl->gl_spin);
633 queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
637 static int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name,
641 if (!sdp->sd_lockstruct.ls_ops->lm_get_lock)
643 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
644 error = sdp->sd_lockstruct.ls_ops->lm_get_lock(
645 sdp->sd_lockstruct.ls_lockspace, name, lockp);
650 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
651 * @sdp: The GFS2 superblock
652 * @number: the lock number
653 * @glops: The glock_operations to use
654 * @create: If 0, don't create the glock if it doesn't exist
655 * @glp: the glock is returned here
657 * This does not lock a glock, just finds/creates structures for one.
662 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
663 const struct gfs2_glock_operations *glops, int create,
664 struct gfs2_glock **glp)
666 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
667 struct gfs2_glock *gl, *tmp;
668 unsigned int hash = gl_hash(sdp, &name);
671 read_lock(gl_lock_addr(hash));
672 gl = search_bucket(hash, sdp, &name);
673 read_unlock(gl_lock_addr(hash));
680 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
686 atomic_set(&gl->gl_ref, 1);
687 gl->gl_state = LM_ST_UNLOCKED;
688 gl->gl_target = LM_ST_UNLOCKED;
689 gl->gl_demote_state = LM_ST_EXCLUSIVE;
692 gl->gl_stamp = jiffies;
693 gl->gl_tchange = jiffies;
694 gl->gl_object = NULL;
696 gl->gl_aspace = NULL;
697 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
699 /* If this glock protects actual on-disk data or metadata blocks,
700 create a VFS inode to manage the pages/buffers holding them. */
701 if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
702 gl->gl_aspace = gfs2_aspace_get(sdp);
703 if (!gl->gl_aspace) {
709 error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock);
713 write_lock(gl_lock_addr(hash));
714 tmp = search_bucket(hash, sdp, &name);
716 write_unlock(gl_lock_addr(hash));
720 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
721 write_unlock(gl_lock_addr(hash));
730 gfs2_aspace_put(gl->gl_aspace);
732 kmem_cache_free(gfs2_glock_cachep, gl);
737 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
739 * @state: the state we're requesting
740 * @flags: the modifier flags
741 * @gh: the holder structure
745 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
746 struct gfs2_holder *gh)
748 INIT_LIST_HEAD(&gh->gh_list);
750 gh->gh_ip = (unsigned long)__builtin_return_address(0);
751 gh->gh_owner_pid = get_pid(task_pid(current));
752 gh->gh_state = state;
753 gh->gh_flags = flags;
760 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
761 * @state: the state we're requesting
762 * @flags: the modifier flags
763 * @gh: the holder structure
765 * Don't mess with the glock.
769 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
771 gh->gh_state = state;
772 gh->gh_flags = flags;
774 gh->gh_ip = (unsigned long)__builtin_return_address(0);
778 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
779 * @gh: the holder structure
783 void gfs2_holder_uninit(struct gfs2_holder *gh)
785 put_pid(gh->gh_owner_pid);
786 gfs2_glock_put(gh->gh_gl);
791 static int just_schedule(void *word)
797 static void wait_on_holder(struct gfs2_holder *gh)
800 wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
803 static void wait_on_demote(struct gfs2_glock *gl)
806 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
810 * handle_callback - process a demote request
812 * @state: the state the caller wants us to change to
814 * There are only two requests that we are going to see in actual
815 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
818 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
819 int remote, unsigned long delay)
821 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
823 set_bit(bit, &gl->gl_flags);
824 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
825 gl->gl_demote_state = state;
826 gl->gl_demote_time = jiffies;
827 if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
829 gfs2_glock_schedule_for_reclaim(gl);
830 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
831 gl->gl_demote_state != state) {
832 gl->gl_demote_state = LM_ST_UNLOCKED;
837 * gfs2_glock_wait - wait on a glock acquisition
838 * @gh: the glock holder
840 * Returns: 0 on success
843 int gfs2_glock_wait(struct gfs2_holder *gh)
849 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
855 struct gfs2_glock_iter *gi = seq->private;
856 vsprintf(gi->string, fmt, args);
857 seq_printf(seq, gi->string);
859 printk(KERN_ERR " ");
866 * add_to_queue - Add a holder to the wait queue (but look for recursion)
867 * @gh: the holder structure to add
869 * Eventually we should move the recursive locking trap to a
870 * debugging option or something like that. This is the fast
871 * path and needs to have the minimum number of distractions.
875 static inline void add_to_queue(struct gfs2_holder *gh)
877 struct gfs2_glock *gl = gh->gh_gl;
878 struct gfs2_sbd *sdp = gl->gl_sbd;
879 struct list_head *insert_pt = NULL;
880 struct gfs2_holder *gh2;
883 BUG_ON(gh->gh_owner_pid == NULL);
884 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
887 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
888 if (test_bit(GLF_LOCK, &gl->gl_flags))
890 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
894 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
895 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
896 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
899 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
900 !may_grant(gl, gh)) {
902 gh->gh_error = GLR_TRYFAILED;
903 gfs2_holder_wake(gh);
906 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
908 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
909 insert_pt = &gh2->gh_list;
911 if (likely(insert_pt == NULL)) {
912 list_add_tail(&gh->gh_list, &gl->gl_holders);
913 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
917 list_add_tail(&gh->gh_list, insert_pt);
919 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
920 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
921 spin_unlock(&gl->gl_spin);
922 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
923 sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock);
924 spin_lock(&gl->gl_spin);
929 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
930 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
931 printk(KERN_ERR "lock type: %d req lock state : %d\n",
932 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
933 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
934 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
935 printk(KERN_ERR "lock type: %d req lock state : %d\n",
936 gh->gh_gl->gl_name.ln_type, gh->gh_state);
937 __dump_glock(NULL, gl);
942 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
943 * @gh: the holder structure
945 * if (gh->gh_flags & GL_ASYNC), this never returns an error
947 * Returns: 0, GLR_TRYFAILED, or errno on failure
950 int gfs2_glock_nq(struct gfs2_holder *gh)
952 struct gfs2_glock *gl = gh->gh_gl;
953 struct gfs2_sbd *sdp = gl->gl_sbd;
956 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
959 spin_lock(&gl->gl_spin);
962 spin_unlock(&gl->gl_spin);
964 if (!(gh->gh_flags & GL_ASYNC))
965 error = gfs2_glock_wait(gh);
971 * gfs2_glock_poll - poll to see if an async request has been completed
974 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
977 int gfs2_glock_poll(struct gfs2_holder *gh)
979 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
983 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
984 * @gh: the glock holder
988 void gfs2_glock_dq(struct gfs2_holder *gh)
990 struct gfs2_glock *gl = gh->gh_gl;
991 const struct gfs2_glock_operations *glops = gl->gl_ops;
995 spin_lock(&gl->gl_spin);
996 if (gh->gh_flags & GL_NOCACHE)
997 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
999 list_del_init(&gh->gh_list);
1000 if (find_first_holder(gl) == NULL) {
1001 if (glops->go_unlock) {
1002 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1003 spin_unlock(&gl->gl_spin);
1004 glops->go_unlock(gh);
1005 spin_lock(&gl->gl_spin);
1006 clear_bit(GLF_LOCK, &gl->gl_flags);
1008 gl->gl_stamp = jiffies;
1009 if (list_empty(&gl->gl_holders) &&
1010 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1011 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1014 spin_unlock(&gl->gl_spin);
1015 if (likely(fast_path))
1018 gfs2_glock_hold(gl);
1019 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1020 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1021 delay = gl->gl_ops->go_min_hold_time;
1022 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1026 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1028 struct gfs2_glock *gl = gh->gh_gl;
1034 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1035 * @gh: the holder structure
1039 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1042 gfs2_holder_uninit(gh);
1046 * gfs2_glock_nq_num - acquire a glock based on lock number
1047 * @sdp: the filesystem
1048 * @number: the lock number
1049 * @glops: the glock operations for the type of glock
1050 * @state: the state to acquire the glock in
1051 * @flags: modifier flags for the aquisition
1052 * @gh: the struct gfs2_holder
1057 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1058 const struct gfs2_glock_operations *glops,
1059 unsigned int state, int flags, struct gfs2_holder *gh)
1061 struct gfs2_glock *gl;
1064 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1066 error = gfs2_glock_nq_init(gl, state, flags, gh);
1074 * glock_compare - Compare two struct gfs2_glock structures for sorting
1075 * @arg_a: the first structure
1076 * @arg_b: the second structure
1080 static int glock_compare(const void *arg_a, const void *arg_b)
1082 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1083 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1084 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1085 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1087 if (a->ln_number > b->ln_number)
1089 if (a->ln_number < b->ln_number)
1091 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1096 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1097 * @num_gh: the number of structures
1098 * @ghs: an array of struct gfs2_holder structures
1100 * Returns: 0 on success (all glocks acquired),
1101 * errno on failure (no glocks acquired)
1104 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1105 struct gfs2_holder **p)
1110 for (x = 0; x < num_gh; x++)
1113 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1115 for (x = 0; x < num_gh; x++) {
1116 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1118 error = gfs2_glock_nq(p[x]);
1121 gfs2_glock_dq(p[x]);
1130 * gfs2_glock_nq_m - acquire multiple glocks
1131 * @num_gh: the number of structures
1132 * @ghs: an array of struct gfs2_holder structures
1135 * Returns: 0 on success (all glocks acquired),
1136 * errno on failure (no glocks acquired)
1139 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1141 struct gfs2_holder *tmp[4];
1142 struct gfs2_holder **pph = tmp;
1149 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1150 return gfs2_glock_nq(ghs);
1154 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1159 error = nq_m_sync(num_gh, ghs, pph);
1168 * gfs2_glock_dq_m - release multiple glocks
1169 * @num_gh: the number of structures
1170 * @ghs: an array of struct gfs2_holder structures
1174 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1178 for (x = 0; x < num_gh; x++)
1179 gfs2_glock_dq(&ghs[x]);
1183 * gfs2_glock_dq_uninit_m - release multiple glocks
1184 * @num_gh: the number of structures
1185 * @ghs: an array of struct gfs2_holder structures
1189 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1193 for (x = 0; x < num_gh; x++)
1194 gfs2_glock_dq_uninit(&ghs[x]);
1197 static int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, void *lock, char **lvbp)
1200 if (!sdp->sd_lockstruct.ls_ops->lm_hold_lvb)
1202 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1203 error = sdp->sd_lockstruct.ls_ops->lm_hold_lvb(lock, lvbp);
1208 * gfs2_lvb_hold - attach a LVB from a glock
1209 * @gl: The glock in question
1213 int gfs2_lvb_hold(struct gfs2_glock *gl)
1217 if (!atomic_read(&gl->gl_lvb_count)) {
1218 error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
1221 gfs2_glock_hold(gl);
1223 atomic_inc(&gl->gl_lvb_count);
1229 * gfs2_lvb_unhold - detach a LVB from a glock
1230 * @gl: The glock in question
1234 void gfs2_lvb_unhold(struct gfs2_glock *gl)
1236 struct gfs2_sbd *sdp = gl->gl_sbd;
1238 gfs2_glock_hold(gl);
1239 gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
1240 if (atomic_dec_and_test(&gl->gl_lvb_count)) {
1241 if (sdp->sd_lockstruct.ls_ops->lm_unhold_lvb)
1242 sdp->sd_lockstruct.ls_ops->lm_unhold_lvb(gl->gl_lock, gl->gl_lvb);
1249 static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
1252 struct gfs2_glock *gl;
1253 unsigned long delay = 0;
1254 unsigned long holdtime;
1255 unsigned long now = jiffies;
1257 gl = gfs2_glock_find(sdp, name);
1261 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
1262 if (time_before(now, holdtime))
1263 delay = holdtime - now;
1265 spin_lock(&gl->gl_spin);
1266 handle_callback(gl, state, 1, delay);
1267 spin_unlock(&gl->gl_spin);
1268 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1273 * gfs2_glock_cb - Callback used by locking module
1274 * @sdp: Pointer to the superblock
1275 * @type: Type of callback
1276 * @data: Type dependent data pointer
1278 * Called by the locking module when it wants to tell us something.
1279 * Either we need to drop a lock, one of our ASYNC requests completed, or
1280 * a journal from another client needs to be recovered.
1283 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
1285 struct gfs2_sbd *sdp = cb_data;
1289 blocking_cb(sdp, data, LM_ST_UNLOCKED);
1293 blocking_cb(sdp, data, LM_ST_DEFERRED);
1297 blocking_cb(sdp, data, LM_ST_SHARED);
1301 struct lm_async_cb *async = data;
1302 struct gfs2_glock *gl;
1304 down_read(&gfs2_umount_flush_sem);
1305 gl = gfs2_glock_find(sdp, &async->lc_name);
1306 if (gfs2_assert_warn(sdp, gl))
1308 gl->gl_reply = async->lc_ret;
1309 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1310 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1312 up_read(&gfs2_umount_flush_sem);
1316 case LM_CB_NEED_RECOVERY:
1317 gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data);
1318 if (sdp->sd_recoverd_process)
1319 wake_up_process(sdp->sd_recoverd_process);
1323 gfs2_assert_warn(sdp, 0);
1329 * demote_ok - Check to see if it's ok to unlock a glock
1332 * Returns: 1 if it's ok
1335 static int demote_ok(struct gfs2_glock *gl)
1337 const struct gfs2_glock_operations *glops = gl->gl_ops;
1340 if (test_bit(GLF_STICKY, &gl->gl_flags))
1342 else if (glops->go_demote_ok)
1343 demote = glops->go_demote_ok(gl);
1349 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1354 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
1356 struct gfs2_sbd *sdp = gl->gl_sbd;
1358 spin_lock(&sdp->sd_reclaim_lock);
1359 if (list_empty(&gl->gl_reclaim)) {
1360 gfs2_glock_hold(gl);
1361 list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
1362 atomic_inc(&sdp->sd_reclaim_count);
1363 spin_unlock(&sdp->sd_reclaim_lock);
1364 wake_up(&sdp->sd_reclaim_wq);
1366 spin_unlock(&sdp->sd_reclaim_lock);
1370 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1371 * @sdp: the filesystem
1373 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1374 * different glock and we notice that there are a lot of glocks in the
1379 void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
1381 struct gfs2_glock *gl;
1382 int done_callback = 0;
1384 spin_lock(&sdp->sd_reclaim_lock);
1385 if (list_empty(&sdp->sd_reclaim_list)) {
1386 spin_unlock(&sdp->sd_reclaim_lock);
1389 gl = list_entry(sdp->sd_reclaim_list.next,
1390 struct gfs2_glock, gl_reclaim);
1391 list_del_init(&gl->gl_reclaim);
1392 spin_unlock(&sdp->sd_reclaim_lock);
1394 atomic_dec(&sdp->sd_reclaim_count);
1395 atomic_inc(&sdp->sd_reclaimed);
1397 spin_lock(&gl->gl_spin);
1398 if (find_first_holder(gl) == NULL &&
1399 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) {
1400 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
1403 spin_unlock(&gl->gl_spin);
1404 if (!done_callback ||
1405 queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1410 * examine_bucket - Call a function for glock in a hash bucket
1411 * @examiner: the function
1412 * @sdp: the filesystem
1413 * @bucket: the bucket
1415 * Returns: 1 if the bucket has entries
1418 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
1421 struct gfs2_glock *gl, *prev = NULL;
1422 int has_entries = 0;
1423 struct hlist_head *head = &gl_hash_table[hash].hb_list;
1425 read_lock(gl_lock_addr(hash));
1426 /* Can't use hlist_for_each_entry - don't want prefetch here */
1427 if (hlist_empty(head))
1429 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1431 if (!sdp || gl->gl_sbd == sdp) {
1432 gfs2_glock_hold(gl);
1433 read_unlock(gl_lock_addr(hash));
1435 gfs2_glock_put(prev);
1439 read_lock(gl_lock_addr(hash));
1441 if (gl->gl_list.next == NULL)
1443 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
1446 read_unlock(gl_lock_addr(hash));
1448 gfs2_glock_put(prev);
1454 * scan_glock - look at a glock and see if we can reclaim it
1455 * @gl: the glock to look at
1459 static void scan_glock(struct gfs2_glock *gl)
1461 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
1463 if (test_bit(GLF_LOCK, &gl->gl_flags))
1466 spin_lock(&gl->gl_spin);
1467 if (find_first_holder(gl) == NULL &&
1468 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1469 gfs2_glock_schedule_for_reclaim(gl);
1470 spin_unlock(&gl->gl_spin);
1474 * clear_glock - look at a glock and see if we can free it from glock cache
1475 * @gl: the glock to look at
1479 static void clear_glock(struct gfs2_glock *gl)
1481 struct gfs2_sbd *sdp = gl->gl_sbd;
1484 spin_lock(&sdp->sd_reclaim_lock);
1485 if (!list_empty(&gl->gl_reclaim)) {
1486 list_del_init(&gl->gl_reclaim);
1487 atomic_dec(&sdp->sd_reclaim_count);
1488 spin_unlock(&sdp->sd_reclaim_lock);
1489 released = gfs2_glock_put(gl);
1490 gfs2_assert(sdp, !released);
1492 spin_unlock(&sdp->sd_reclaim_lock);
1495 spin_lock(&gl->gl_spin);
1496 if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
1497 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
1498 spin_unlock(&gl->gl_spin);
1499 gfs2_glock_hold(gl);
1500 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1505 * gfs2_gl_hash_clear - Empty out the glock hash table
1506 * @sdp: the filesystem
1507 * @wait: wait until it's all gone
1509 * Called when unmounting the filesystem.
1512 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1522 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1523 if (examine_bucket(clear_glock, sdp, x))
1530 if (time_after_eq(jiffies,
1531 t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
1532 fs_warn(sdp, "Unmount seems to be stalled. "
1533 "Dumping lock state...\n");
1534 gfs2_dump_lockstate(sdp);
1538 down_write(&gfs2_umount_flush_sem);
1539 invalidate_inodes(sdp->sd_vfs);
1540 up_write(&gfs2_umount_flush_sem);
1545 static const char *state2str(unsigned state)
1548 case LM_ST_UNLOCKED:
1552 case LM_ST_DEFERRED:
1554 case LM_ST_EXCLUSIVE:
1560 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1563 if (flags & LM_FLAG_TRY)
1565 if (flags & LM_FLAG_TRY_1CB)
1567 if (flags & LM_FLAG_NOEXP)
1569 if (flags & LM_FLAG_ANY)
1571 if (flags & LM_FLAG_PRIORITY)
1573 if (flags & GL_ASYNC)
1575 if (flags & GL_EXACT)
1577 if (flags & GL_ATIME)
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_STICKY, gflags))
1624 if (test_bit(GLF_DEMOTE, gflags))
1626 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1628 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1630 if (test_bit(GLF_DIRTY, gflags))
1632 if (test_bit(GLF_LFLUSH, gflags))
1634 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1636 if (test_bit(GLF_REPLY_PENDING, gflags))
1643 * __dump_glock - print information about a glock
1644 * @seq: The seq_file struct
1647 * The file format is as follows:
1648 * One line per object, capital letters are used to indicate objects
1649 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1650 * other objects are indented by a single space and follow the glock to
1651 * which they are related. Fields are indicated by lower case letters
1652 * followed by a colon and the field value, except for strings which are in
1653 * [] so that its possible to see if they are composed of spaces for
1654 * example. The field's are n = number (id of the object), f = flags,
1655 * t = type, s = state, r = refcount, e = error, p = pid.
1657 * Returns: 0 on success, -ENOBUFS when we run out of space
1660 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1662 const struct gfs2_glock_operations *glops = gl->gl_ops;
1663 unsigned long long dtime;
1664 const struct gfs2_holder *gh;
1665 char gflags_buf[32];
1668 dtime = jiffies - gl->gl_demote_time;
1669 dtime *= 1000000/HZ; /* demote time in uSec */
1670 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1672 gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu l:%d a:%d r:%d\n",
1673 state2str(gl->gl_state),
1674 gl->gl_name.ln_type,
1675 (unsigned long long)gl->gl_name.ln_number,
1676 gflags2str(gflags_buf, &gl->gl_flags),
1677 state2str(gl->gl_target),
1678 state2str(gl->gl_demote_state), dtime,
1679 atomic_read(&gl->gl_lvb_count),
1680 atomic_read(&gl->gl_ail_count),
1681 atomic_read(&gl->gl_ref));
1683 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1684 error = dump_holder(seq, gh);
1688 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1689 error = glops->go_dump(seq, gl);
1694 static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1697 spin_lock(&gl->gl_spin);
1698 ret = __dump_glock(seq, gl);
1699 spin_unlock(&gl->gl_spin);
1704 * gfs2_dump_lockstate - print out the current lockstate
1705 * @sdp: the filesystem
1706 * @ub: the buffer to copy the information into
1708 * If @ub is NULL, dump the lockstate to the console.
1712 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
1714 struct gfs2_glock *gl;
1715 struct hlist_node *h;
1719 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1721 read_lock(gl_lock_addr(x));
1723 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
1724 if (gl->gl_sbd != sdp)
1727 error = dump_glock(NULL, gl);
1732 read_unlock(gl_lock_addr(x));
1743 * gfs2_scand - Look for cached glocks and inodes to toss from memory
1744 * @sdp: Pointer to GFS2 superblock
1746 * One of these daemons runs, finding candidates to add to sd_reclaim_list.
1750 static int gfs2_scand(void *data)
1755 while (!kthread_should_stop()) {
1756 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1757 examine_bucket(scan_glock, NULL, x);
1758 if (freezing(current))
1763 schedule_timeout_interruptible(delay * HZ);
1771 int __init gfs2_glock_init(void)
1774 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1775 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
1777 #ifdef GL_HASH_LOCK_SZ
1778 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1779 rwlock_init(&gl_hash_locks[i]);
1783 scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand");
1784 if (IS_ERR(scand_process))
1785 return PTR_ERR(scand_process);
1787 glock_workqueue = create_workqueue("glock_workqueue");
1788 if (IS_ERR(glock_workqueue)) {
1789 kthread_stop(scand_process);
1790 return PTR_ERR(glock_workqueue);
1796 void gfs2_glock_exit(void)
1798 destroy_workqueue(glock_workqueue);
1799 kthread_stop(scand_process);
1802 module_param(scand_secs, uint, S_IRUGO|S_IWUSR);
1803 MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs");
1805 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1807 struct gfs2_glock *gl;
1810 read_lock(gl_lock_addr(gi->hash));
1813 gi->gl = hlist_entry(gl->gl_list.next,
1814 struct gfs2_glock, gl_list);
1816 gfs2_glock_hold(gi->gl);
1818 read_unlock(gl_lock_addr(gi->hash));
1821 if (gl && gi->gl == NULL)
1823 while (gi->gl == NULL) {
1824 if (gi->hash >= GFS2_GL_HASH_SIZE)
1826 read_lock(gl_lock_addr(gi->hash));
1827 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1828 struct gfs2_glock, gl_list);
1830 gfs2_glock_hold(gi->gl);
1831 read_unlock(gl_lock_addr(gi->hash));
1835 if (gi->sdp != gi->gl->gl_sbd)
1841 static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
1844 gfs2_glock_put(gi->gl);
1848 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1850 struct gfs2_glock_iter *gi = seq->private;
1856 if (gfs2_glock_iter_next(gi)) {
1857 gfs2_glock_iter_free(gi);
1865 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1868 struct gfs2_glock_iter *gi = seq->private;
1872 if (gfs2_glock_iter_next(gi)) {
1873 gfs2_glock_iter_free(gi);
1880 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1882 struct gfs2_glock_iter *gi = seq->private;
1883 gfs2_glock_iter_free(gi);
1886 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1888 return dump_glock(seq, iter_ptr);
1891 static const struct seq_operations gfs2_glock_seq_ops = {
1892 .start = gfs2_glock_seq_start,
1893 .next = gfs2_glock_seq_next,
1894 .stop = gfs2_glock_seq_stop,
1895 .show = gfs2_glock_seq_show,
1898 static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1900 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1901 sizeof(struct gfs2_glock_iter));
1903 struct seq_file *seq = file->private_data;
1904 struct gfs2_glock_iter *gi = seq->private;
1905 gi->sdp = inode->i_private;
1910 static const struct file_operations gfs2_debug_fops = {
1911 .owner = THIS_MODULE,
1912 .open = gfs2_debugfs_open,
1914 .llseek = seq_lseek,
1915 .release = seq_release_private,
1918 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1920 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1921 if (!sdp->debugfs_dir)
1923 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1925 sdp->debugfs_dir, sdp,
1927 if (!sdp->debugfs_dentry_glocks)
1933 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1935 if (sdp && sdp->debugfs_dir) {
1936 if (sdp->debugfs_dentry_glocks) {
1937 debugfs_remove(sdp->debugfs_dentry_glocks);
1938 sdp->debugfs_dentry_glocks = NULL;
1940 debugfs_remove(sdp->debugfs_dir);
1941 sdp->debugfs_dir = NULL;
1945 int gfs2_register_debugfs(void)
1947 gfs2_root = debugfs_create_dir("gfs2", NULL);
1948 return gfs2_root ? 0 : -ENOMEM;
1951 void gfs2_unregister_debugfs(void)
1953 debugfs_remove(gfs2_root);