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 <linux/rwsem.h>
23 #include <asm/uaccess.h>
24 #include <linux/seq_file.h>
25 #include <linux/debugfs.h>
26 #include <linux/kthread.h>
27 #include <linux/freezer.h>
28 #include <linux/workqueue.h>
29 #include <linux/jiffies.h>
42 #define CREATE_TRACE_POINTS
43 #include "trace_gfs2.h"
45 struct gfs2_gl_hash_bucket {
46 struct hlist_head hb_list;
49 struct gfs2_glock_iter {
50 int hash; /* hash bucket index */
51 struct gfs2_sbd *sdp; /* incore superblock */
52 struct gfs2_glock *gl; /* current glock struct */
53 char string[512]; /* scratch space */
56 typedef void (*glock_examiner) (struct gfs2_glock * gl);
58 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
59 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
60 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
61 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
63 static DECLARE_RWSEM(gfs2_umount_flush_sem);
64 static struct dentry *gfs2_root;
65 static struct workqueue_struct *glock_workqueue;
66 struct workqueue_struct *gfs2_delete_workqueue;
67 static LIST_HEAD(lru_list);
68 static atomic_t lru_count = ATOMIC_INIT(0);
69 static DEFINE_SPINLOCK(lru_lock);
71 #define GFS2_GL_HASH_SHIFT 15
72 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
73 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
75 static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
76 static struct dentry *gfs2_root;
79 * Despite what you might think, the numbers below are not arbitrary :-)
80 * They are taken from the ipv4 routing hash code, which is well tested
81 * and thus should be nearly optimal. Later on we might tweek the numbers
82 * but for now this should be fine.
84 * The reason for putting the locks in a separate array from the list heads
85 * is that we can have fewer locks than list heads and save memory. We use
86 * the same hash function for both, but with a different hash mask.
88 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
89 defined(CONFIG_PROVE_LOCKING)
92 # define GL_HASH_LOCK_SZ 256
95 # define GL_HASH_LOCK_SZ 4096
97 # define GL_HASH_LOCK_SZ 2048
99 # define GL_HASH_LOCK_SZ 1024
101 # define GL_HASH_LOCK_SZ 512
103 # define GL_HASH_LOCK_SZ 256
107 /* We never want more locks than chains */
108 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
109 # undef GL_HASH_LOCK_SZ
110 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
113 static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
115 static inline rwlock_t *gl_lock_addr(unsigned int x)
117 return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
119 #else /* not SMP, so no spinlocks required */
120 static inline rwlock_t *gl_lock_addr(unsigned int x)
127 * gl_hash() - Turn glock number into hash bucket number
128 * @lock: The glock number
130 * Returns: The number of the corresponding hash bucket
133 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
134 const struct lm_lockname *name)
138 h = jhash(&name->ln_number, sizeof(u64), 0);
139 h = jhash(&name->ln_type, sizeof(unsigned int), h);
140 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
141 h &= GFS2_GL_HASH_MASK;
147 * glock_free() - Perform a few checks and then release struct gfs2_glock
148 * @gl: The glock to release
150 * Also calls lock module to release its internal structure for this glock.
154 static void glock_free(struct gfs2_glock *gl)
156 struct gfs2_sbd *sdp = gl->gl_sbd;
157 struct address_space *mapping = gfs2_glock2aspace(gl);
158 struct kmem_cache *cachep = gfs2_glock_cachep;
160 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
161 trace_gfs2_glock_put(gl);
163 cachep = gfs2_glock_aspace_cachep;
164 sdp->sd_lockstruct.ls_ops->lm_put_lock(cachep, gl);
168 * gfs2_glock_hold() - increment reference count on glock
169 * @gl: The glock to hold
173 void gfs2_glock_hold(struct gfs2_glock *gl)
175 GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0);
176 atomic_inc(&gl->gl_ref);
180 * demote_ok - Check to see if it's ok to unlock a glock
183 * Returns: 1 if it's ok
186 static int demote_ok(const struct gfs2_glock *gl)
188 const struct gfs2_glock_operations *glops = gl->gl_ops;
190 if (gl->gl_state == LM_ST_UNLOCKED)
192 if (!list_empty(&gl->gl_holders))
194 if (glops->go_demote_ok)
195 return glops->go_demote_ok(gl);
200 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
205 static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
208 may_reclaim = (demote_ok(gl) &&
209 (atomic_read(&gl->gl_ref) == 1 ||
210 (gl->gl_name.ln_type == LM_TYPE_INODE &&
211 atomic_read(&gl->gl_ref) <= 2)));
212 spin_lock(&lru_lock);
213 if (list_empty(&gl->gl_lru) && may_reclaim) {
214 list_add_tail(&gl->gl_lru, &lru_list);
215 atomic_inc(&lru_count);
217 spin_unlock(&lru_lock);
221 * gfs2_glock_put_nolock() - Decrement reference count on glock
222 * @gl: The glock to put
224 * This function should only be used if the caller has its own reference
225 * to the glock, in addition to the one it is dropping.
228 void gfs2_glock_put_nolock(struct gfs2_glock *gl)
230 if (atomic_dec_and_test(&gl->gl_ref))
232 gfs2_glock_schedule_for_reclaim(gl);
236 * gfs2_glock_put() - Decrement reference count on glock
237 * @gl: The glock to put
241 int gfs2_glock_put(struct gfs2_glock *gl)
245 write_lock(gl_lock_addr(gl->gl_hash));
246 if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) {
247 hlist_del(&gl->gl_list);
248 if (!list_empty(&gl->gl_lru)) {
249 list_del_init(&gl->gl_lru);
250 atomic_dec(&lru_count);
252 spin_unlock(&lru_lock);
253 write_unlock(gl_lock_addr(gl->gl_hash));
254 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
259 spin_lock(&gl->gl_spin);
260 gfs2_glock_schedule_for_reclaim(gl);
261 spin_unlock(&gl->gl_spin);
262 write_unlock(gl_lock_addr(gl->gl_hash));
268 * search_bucket() - Find struct gfs2_glock by lock number
269 * @bucket: the bucket to search
270 * @name: The lock name
272 * Returns: NULL, or the struct gfs2_glock with the requested number
275 static struct gfs2_glock *search_bucket(unsigned int hash,
276 const struct gfs2_sbd *sdp,
277 const struct lm_lockname *name)
279 struct gfs2_glock *gl;
280 struct hlist_node *h;
282 hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
283 if (!lm_name_equal(&gl->gl_name, name))
285 if (gl->gl_sbd != sdp)
288 atomic_inc(&gl->gl_ref);
297 * may_grant - check if its ok to grant a new lock
299 * @gh: The lock request which we wish to grant
301 * Returns: true if its ok to grant the lock
304 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
306 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
307 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
308 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
310 if (gl->gl_state == gh->gh_state)
312 if (gh->gh_flags & GL_EXACT)
314 if (gl->gl_state == LM_ST_EXCLUSIVE) {
315 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
317 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
320 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
325 static void gfs2_holder_wake(struct gfs2_holder *gh)
327 clear_bit(HIF_WAIT, &gh->gh_iflags);
328 smp_mb__after_clear_bit();
329 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
333 * do_promote - promote as many requests as possible on the current queue
336 * Returns: 1 if there is a blocked holder at the head of the list, or 2
337 * if a type specific operation is underway.
340 static int do_promote(struct gfs2_glock *gl)
341 __releases(&gl->gl_spin)
342 __acquires(&gl->gl_spin)
344 const struct gfs2_glock_operations *glops = gl->gl_ops;
345 struct gfs2_holder *gh, *tmp;
349 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
350 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
352 if (may_grant(gl, gh)) {
353 if (gh->gh_list.prev == &gl->gl_holders &&
355 spin_unlock(&gl->gl_spin);
356 /* FIXME: eliminate this eventually */
357 ret = glops->go_lock(gh);
358 spin_lock(&gl->gl_spin);
363 list_del_init(&gh->gh_list);
364 trace_gfs2_glock_queue(gh, 0);
365 gfs2_holder_wake(gh);
368 set_bit(HIF_HOLDER, &gh->gh_iflags);
369 trace_gfs2_promote(gh, 1);
370 gfs2_holder_wake(gh);
373 set_bit(HIF_HOLDER, &gh->gh_iflags);
374 trace_gfs2_promote(gh, 0);
375 gfs2_holder_wake(gh);
378 if (gh->gh_list.prev == &gl->gl_holders)
386 * do_error - Something unexpected has happened during a lock request
390 static inline void do_error(struct gfs2_glock *gl, const int ret)
392 struct gfs2_holder *gh, *tmp;
394 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
395 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
397 if (ret & LM_OUT_ERROR)
399 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
400 gh->gh_error = GLR_TRYFAILED;
403 list_del_init(&gh->gh_list);
404 trace_gfs2_glock_queue(gh, 0);
405 gfs2_holder_wake(gh);
410 * find_first_waiter - find the first gh that's waiting for the glock
414 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
416 struct gfs2_holder *gh;
418 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
419 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
426 * state_change - record that the glock is now in a different state
428 * @new_state the new state
432 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
436 held1 = (gl->gl_state != LM_ST_UNLOCKED);
437 held2 = (new_state != LM_ST_UNLOCKED);
439 if (held1 != held2) {
443 gfs2_glock_put_nolock(gl);
446 gl->gl_state = new_state;
447 gl->gl_tchange = jiffies;
450 static void gfs2_demote_wake(struct gfs2_glock *gl)
452 gl->gl_demote_state = LM_ST_EXCLUSIVE;
453 clear_bit(GLF_DEMOTE, &gl->gl_flags);
454 smp_mb__after_clear_bit();
455 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
459 * finish_xmote - The DLM has replied to one of our lock requests
461 * @ret: The status from the DLM
465 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
467 const struct gfs2_glock_operations *glops = gl->gl_ops;
468 struct gfs2_holder *gh;
469 unsigned state = ret & LM_OUT_ST_MASK;
472 spin_lock(&gl->gl_spin);
473 trace_gfs2_glock_state_change(gl, state);
474 state_change(gl, state);
475 gh = find_first_waiter(gl);
477 /* Demote to UN request arrived during demote to SH or DF */
478 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
479 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
480 gl->gl_target = LM_ST_UNLOCKED;
482 /* Check for state != intended state */
483 if (unlikely(state != gl->gl_target)) {
484 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
485 /* move to back of queue and try next entry */
486 if (ret & LM_OUT_CANCELED) {
487 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
488 list_move_tail(&gh->gh_list, &gl->gl_holders);
489 gh = find_first_waiter(gl);
490 gl->gl_target = gh->gh_state;
493 /* Some error or failed "try lock" - report it */
494 if ((ret & LM_OUT_ERROR) ||
495 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
496 gl->gl_target = gl->gl_state;
502 /* Unlocked due to conversion deadlock, try again */
505 do_xmote(gl, gh, gl->gl_target);
507 /* Conversion fails, unlock and try again */
510 do_xmote(gl, gh, LM_ST_UNLOCKED);
512 default: /* Everything else */
513 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
516 spin_unlock(&gl->gl_spin);
520 /* Fast path - we got what we asked for */
521 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
522 gfs2_demote_wake(gl);
523 if (state != LM_ST_UNLOCKED) {
524 if (glops->go_xmote_bh) {
525 spin_unlock(&gl->gl_spin);
526 rv = glops->go_xmote_bh(gl, gh);
527 spin_lock(&gl->gl_spin);
538 clear_bit(GLF_LOCK, &gl->gl_flags);
540 spin_unlock(&gl->gl_spin);
543 static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
544 unsigned int req_state,
547 int ret = LM_OUT_ERROR;
549 if (!sdp->sd_lockstruct.ls_ops->lm_lock)
550 return req_state == LM_ST_UNLOCKED ? 0 : req_state;
552 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
553 ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock,
559 * do_xmote - Calls the DLM to change the state of a lock
560 * @gl: The lock state
561 * @gh: The holder (only for promotes)
562 * @target: The target lock state
566 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
567 __releases(&gl->gl_spin)
568 __acquires(&gl->gl_spin)
570 const struct gfs2_glock_operations *glops = gl->gl_ops;
571 struct gfs2_sbd *sdp = gl->gl_sbd;
572 unsigned int lck_flags = gh ? gh->gh_flags : 0;
575 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
577 BUG_ON(gl->gl_state == target);
578 BUG_ON(gl->gl_state == gl->gl_target);
579 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
581 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
582 do_error(gl, 0); /* Fail queued try locks */
584 spin_unlock(&gl->gl_spin);
585 if (glops->go_xmote_th)
586 glops->go_xmote_th(gl);
587 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
588 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
589 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
592 if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
593 gl->gl_state == LM_ST_DEFERRED) &&
594 !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
595 lck_flags |= LM_FLAG_TRY_1CB;
596 ret = gfs2_lm_lock(sdp, gl, target, lck_flags);
598 if (!(ret & LM_OUT_ASYNC)) {
599 finish_xmote(gl, ret);
600 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
603 GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
605 spin_lock(&gl->gl_spin);
609 * find_first_holder - find the first "holder" gh
613 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
615 struct gfs2_holder *gh;
617 if (!list_empty(&gl->gl_holders)) {
618 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
619 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
626 * run_queue - do all outstanding tasks related to a glock
627 * @gl: The glock in question
628 * @nonblock: True if we must not block in run_queue
632 static void run_queue(struct gfs2_glock *gl, const int nonblock)
633 __releases(&gl->gl_spin)
634 __acquires(&gl->gl_spin)
636 struct gfs2_holder *gh = NULL;
639 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
642 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
644 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
645 gl->gl_demote_state != gl->gl_state) {
646 if (find_first_holder(gl))
650 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
651 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
652 gl->gl_target = gl->gl_demote_state;
654 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
655 gfs2_demote_wake(gl);
656 ret = do_promote(gl);
661 gh = find_first_waiter(gl);
662 gl->gl_target = gh->gh_state;
663 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
664 do_error(gl, 0); /* Fail queued try locks */
666 do_xmote(gl, gh, gl->gl_target);
671 clear_bit(GLF_LOCK, &gl->gl_flags);
672 smp_mb__after_clear_bit();
674 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
675 gfs2_glock_put_nolock(gl);
679 clear_bit(GLF_LOCK, &gl->gl_flags);
680 smp_mb__after_clear_bit();
684 static void delete_work_func(struct work_struct *work)
686 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
687 struct gfs2_sbd *sdp = gl->gl_sbd;
688 struct gfs2_inode *ip = NULL;
692 spin_lock(&gl->gl_spin);
693 ip = (struct gfs2_inode *)gl->gl_object;
695 no_addr = ip->i_no_addr;
696 spin_unlock(&gl->gl_spin);
698 inode = gfs2_ilookup(sdp->sd_vfs, no_addr);
700 d_prune_aliases(inode);
707 static void glock_work_func(struct work_struct *work)
709 unsigned long delay = 0;
710 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
713 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
714 finish_xmote(gl, gl->gl_reply);
717 down_read(&gfs2_umount_flush_sem);
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);
730 up_read(&gfs2_umount_flush_sem);
732 queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
739 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
740 * @sdp: The GFS2 superblock
741 * @number: the lock number
742 * @glops: The glock_operations to use
743 * @create: If 0, don't create the glock if it doesn't exist
744 * @glp: the glock is returned here
746 * This does not lock a glock, just finds/creates structures for one.
751 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
752 const struct gfs2_glock_operations *glops, int create,
753 struct gfs2_glock **glp)
755 struct super_block *s = sdp->sd_vfs;
756 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
757 struct gfs2_glock *gl, *tmp;
758 unsigned int hash = gl_hash(sdp, &name);
759 struct address_space *mapping;
761 read_lock(gl_lock_addr(hash));
762 gl = search_bucket(hash, sdp, &name);
763 read_unlock(gl_lock_addr(hash));
771 if (glops->go_flags & GLOF_ASPACE)
772 gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL);
774 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
778 atomic_inc(&sdp->sd_glock_disposal);
781 atomic_set(&gl->gl_ref, 1);
782 gl->gl_state = LM_ST_UNLOCKED;
783 gl->gl_target = LM_ST_UNLOCKED;
784 gl->gl_demote_state = LM_ST_EXCLUSIVE;
787 snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number);
788 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
789 gl->gl_lksb.sb_lvbptr = gl->gl_lvb;
790 gl->gl_tchange = jiffies;
791 gl->gl_object = NULL;
793 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
794 INIT_WORK(&gl->gl_delete, delete_work_func);
796 mapping = gfs2_glock2aspace(gl);
798 mapping->a_ops = &gfs2_meta_aops;
799 mapping->host = s->s_bdev->bd_inode;
801 mapping_set_gfp_mask(mapping, GFP_NOFS);
802 mapping->assoc_mapping = NULL;
803 mapping->backing_dev_info = s->s_bdi;
804 mapping->writeback_index = 0;
807 write_lock(gl_lock_addr(hash));
808 tmp = search_bucket(hash, sdp, &name);
810 write_unlock(gl_lock_addr(hash));
814 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
815 write_unlock(gl_lock_addr(hash));
824 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
826 * @state: the state we're requesting
827 * @flags: the modifier flags
828 * @gh: the holder structure
832 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
833 struct gfs2_holder *gh)
835 INIT_LIST_HEAD(&gh->gh_list);
837 gh->gh_ip = (unsigned long)__builtin_return_address(0);
838 gh->gh_owner_pid = get_pid(task_pid(current));
839 gh->gh_state = state;
840 gh->gh_flags = flags;
847 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
848 * @state: the state we're requesting
849 * @flags: the modifier flags
850 * @gh: the holder structure
852 * Don't mess with the glock.
856 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
858 gh->gh_state = state;
859 gh->gh_flags = flags;
861 gh->gh_ip = (unsigned long)__builtin_return_address(0);
865 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
866 * @gh: the holder structure
870 void gfs2_holder_uninit(struct gfs2_holder *gh)
872 put_pid(gh->gh_owner_pid);
873 gfs2_glock_put(gh->gh_gl);
879 * gfs2_glock_holder_wait
882 * This function and gfs2_glock_demote_wait both show up in the WCHAN
883 * field. Thus I've separated these otherwise identical functions in
884 * order to be more informative to the user.
887 static int gfs2_glock_holder_wait(void *word)
893 static int gfs2_glock_demote_wait(void *word)
899 static void wait_on_holder(struct gfs2_holder *gh)
902 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
905 static void wait_on_demote(struct gfs2_glock *gl)
908 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
912 * handle_callback - process a demote request
914 * @state: the state the caller wants us to change to
916 * There are only two requests that we are going to see in actual
917 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
920 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
923 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
925 set_bit(bit, &gl->gl_flags);
926 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
927 gl->gl_demote_state = state;
928 gl->gl_demote_time = jiffies;
929 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
930 gl->gl_demote_state != state) {
931 gl->gl_demote_state = LM_ST_UNLOCKED;
933 if (gl->gl_ops->go_callback)
934 gl->gl_ops->go_callback(gl);
935 trace_gfs2_demote_rq(gl);
939 * gfs2_glock_wait - wait on a glock acquisition
940 * @gh: the glock holder
942 * Returns: 0 on success
945 int gfs2_glock_wait(struct gfs2_holder *gh)
951 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
957 struct gfs2_glock_iter *gi = seq->private;
958 vsprintf(gi->string, fmt, args);
959 seq_printf(seq, gi->string);
961 printk(KERN_ERR " ");
968 * add_to_queue - Add a holder to the wait queue (but look for recursion)
969 * @gh: the holder structure to add
971 * Eventually we should move the recursive locking trap to a
972 * debugging option or something like that. This is the fast
973 * path and needs to have the minimum number of distractions.
977 static inline void add_to_queue(struct gfs2_holder *gh)
978 __releases(&gl->gl_spin)
979 __acquires(&gl->gl_spin)
981 struct gfs2_glock *gl = gh->gh_gl;
982 struct gfs2_sbd *sdp = gl->gl_sbd;
983 struct list_head *insert_pt = NULL;
984 struct gfs2_holder *gh2;
987 BUG_ON(gh->gh_owner_pid == NULL);
988 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
991 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
992 if (test_bit(GLF_LOCK, &gl->gl_flags))
994 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
998 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
999 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
1000 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
1001 goto trap_recursive;
1003 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
1004 !may_grant(gl, gh)) {
1006 gh->gh_error = GLR_TRYFAILED;
1007 gfs2_holder_wake(gh);
1010 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
1012 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
1013 insert_pt = &gh2->gh_list;
1015 if (likely(insert_pt == NULL)) {
1016 list_add_tail(&gh->gh_list, &gl->gl_holders);
1017 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1021 trace_gfs2_glock_queue(gh, 1);
1022 list_add_tail(&gh->gh_list, insert_pt);
1024 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1025 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1026 spin_unlock(&gl->gl_spin);
1027 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1028 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1029 spin_lock(&gl->gl_spin);
1034 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
1035 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1036 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1037 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1038 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
1039 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
1040 printk(KERN_ERR "lock type: %d req lock state : %d\n",
1041 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1042 __dump_glock(NULL, gl);
1047 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1048 * @gh: the holder structure
1050 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1052 * Returns: 0, GLR_TRYFAILED, or errno on failure
1055 int gfs2_glock_nq(struct gfs2_holder *gh)
1057 struct gfs2_glock *gl = gh->gh_gl;
1058 struct gfs2_sbd *sdp = gl->gl_sbd;
1061 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1064 spin_lock(&gl->gl_spin);
1067 spin_unlock(&gl->gl_spin);
1069 if (!(gh->gh_flags & GL_ASYNC))
1070 error = gfs2_glock_wait(gh);
1076 * gfs2_glock_poll - poll to see if an async request has been completed
1079 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1082 int gfs2_glock_poll(struct gfs2_holder *gh)
1084 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1088 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1089 * @gh: the glock holder
1093 void gfs2_glock_dq(struct gfs2_holder *gh)
1095 struct gfs2_glock *gl = gh->gh_gl;
1096 const struct gfs2_glock_operations *glops = gl->gl_ops;
1100 spin_lock(&gl->gl_spin);
1101 if (gh->gh_flags & GL_NOCACHE)
1102 handle_callback(gl, LM_ST_UNLOCKED, 0);
1104 list_del_init(&gh->gh_list);
1105 if (find_first_holder(gl) == NULL) {
1106 if (glops->go_unlock) {
1107 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1108 spin_unlock(&gl->gl_spin);
1109 glops->go_unlock(gh);
1110 spin_lock(&gl->gl_spin);
1111 clear_bit(GLF_LOCK, &gl->gl_flags);
1113 if (list_empty(&gl->gl_holders) &&
1114 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1115 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1118 trace_gfs2_glock_queue(gh, 0);
1119 spin_unlock(&gl->gl_spin);
1120 if (likely(fast_path))
1123 gfs2_glock_hold(gl);
1124 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1125 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1126 delay = gl->gl_ops->go_min_hold_time;
1127 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1131 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1133 struct gfs2_glock *gl = gh->gh_gl;
1139 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1140 * @gh: the holder structure
1144 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1147 gfs2_holder_uninit(gh);
1151 * gfs2_glock_nq_num - acquire a glock based on lock number
1152 * @sdp: the filesystem
1153 * @number: the lock number
1154 * @glops: the glock operations for the type of glock
1155 * @state: the state to acquire the glock in
1156 * @flags: modifier flags for the aquisition
1157 * @gh: the struct gfs2_holder
1162 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1163 const struct gfs2_glock_operations *glops,
1164 unsigned int state, int flags, struct gfs2_holder *gh)
1166 struct gfs2_glock *gl;
1169 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1171 error = gfs2_glock_nq_init(gl, state, flags, gh);
1179 * glock_compare - Compare two struct gfs2_glock structures for sorting
1180 * @arg_a: the first structure
1181 * @arg_b: the second structure
1185 static int glock_compare(const void *arg_a, const void *arg_b)
1187 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1188 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1189 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1190 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1192 if (a->ln_number > b->ln_number)
1194 if (a->ln_number < b->ln_number)
1196 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1201 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1202 * @num_gh: the number of structures
1203 * @ghs: an array of struct gfs2_holder structures
1205 * Returns: 0 on success (all glocks acquired),
1206 * errno on failure (no glocks acquired)
1209 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1210 struct gfs2_holder **p)
1215 for (x = 0; x < num_gh; x++)
1218 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1220 for (x = 0; x < num_gh; x++) {
1221 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1223 error = gfs2_glock_nq(p[x]);
1226 gfs2_glock_dq(p[x]);
1235 * gfs2_glock_nq_m - acquire multiple glocks
1236 * @num_gh: the number of structures
1237 * @ghs: an array of struct gfs2_holder structures
1240 * Returns: 0 on success (all glocks acquired),
1241 * errno on failure (no glocks acquired)
1244 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1246 struct gfs2_holder *tmp[4];
1247 struct gfs2_holder **pph = tmp;
1254 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1255 return gfs2_glock_nq(ghs);
1259 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1264 error = nq_m_sync(num_gh, ghs, pph);
1273 * gfs2_glock_dq_m - release multiple glocks
1274 * @num_gh: the number of structures
1275 * @ghs: an array of struct gfs2_holder structures
1279 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1283 for (x = 0; x < num_gh; x++)
1284 gfs2_glock_dq(&ghs[x]);
1288 * gfs2_glock_dq_uninit_m - release multiple glocks
1289 * @num_gh: the number of structures
1290 * @ghs: an array of struct gfs2_holder structures
1294 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1298 for (x = 0; x < num_gh; x++)
1299 gfs2_glock_dq_uninit(&ghs[x]);
1302 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1304 unsigned long delay = 0;
1305 unsigned long holdtime;
1306 unsigned long now = jiffies;
1308 gfs2_glock_hold(gl);
1309 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
1310 if (time_before(now, holdtime))
1311 delay = holdtime - now;
1312 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1313 delay = gl->gl_ops->go_min_hold_time;
1315 spin_lock(&gl->gl_spin);
1316 handle_callback(gl, state, delay);
1317 spin_unlock(&gl->gl_spin);
1318 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1323 * gfs2_glock_complete - Callback used by locking
1324 * @gl: Pointer to the glock
1325 * @ret: The return value from the dlm
1329 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1331 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1333 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) {
1334 struct gfs2_holder *gh;
1335 spin_lock(&gl->gl_spin);
1336 gh = find_first_waiter(gl);
1337 if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) &&
1338 (gl->gl_target != LM_ST_UNLOCKED)) ||
1339 ((ret & ~LM_OUT_ST_MASK) != 0))
1340 set_bit(GLF_FROZEN, &gl->gl_flags);
1341 spin_unlock(&gl->gl_spin);
1342 if (test_bit(GLF_FROZEN, &gl->gl_flags))
1345 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1346 gfs2_glock_hold(gl);
1347 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1352 static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask)
1354 struct gfs2_glock *gl;
1362 if (!(gfp_mask & __GFP_FS))
1365 spin_lock(&lru_lock);
1366 while(nr && !list_empty(&lru_list)) {
1367 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1368 list_del_init(&gl->gl_lru);
1369 atomic_dec(&lru_count);
1371 /* Test for being demotable */
1372 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1373 gfs2_glock_hold(gl);
1374 spin_unlock(&lru_lock);
1375 spin_lock(&gl->gl_spin);
1376 may_demote = demote_ok(gl);
1378 handle_callback(gl, LM_ST_UNLOCKED, 0);
1381 clear_bit(GLF_LOCK, &gl->gl_flags);
1382 smp_mb__after_clear_bit();
1383 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1384 gfs2_glock_put_nolock(gl);
1385 spin_unlock(&gl->gl_spin);
1386 spin_lock(&lru_lock);
1390 list_add(&gl->gl_lru, &skipped);
1392 list_splice(&skipped, &lru_list);
1393 atomic_add(nr_skipped, &lru_count);
1394 spin_unlock(&lru_lock);
1396 return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
1399 static struct shrinker glock_shrinker = {
1400 .shrink = gfs2_shrink_glock_memory,
1401 .seeks = DEFAULT_SEEKS,
1405 * examine_bucket - Call a function for glock in a hash bucket
1406 * @examiner: the function
1407 * @sdp: the filesystem
1408 * @bucket: the bucket
1410 * Returns: 1 if the bucket has entries
1413 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
1416 struct gfs2_glock *gl, *prev = NULL;
1417 int has_entries = 0;
1418 struct hlist_head *head = &gl_hash_table[hash].hb_list;
1420 read_lock(gl_lock_addr(hash));
1421 /* Can't use hlist_for_each_entry - don't want prefetch here */
1422 if (hlist_empty(head))
1424 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1426 if (!sdp || gl->gl_sbd == sdp) {
1427 gfs2_glock_hold(gl);
1428 read_unlock(gl_lock_addr(hash));
1430 gfs2_glock_put(prev);
1434 read_lock(gl_lock_addr(hash));
1436 if (gl->gl_list.next == NULL)
1438 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
1441 read_unlock(gl_lock_addr(hash));
1443 gfs2_glock_put(prev);
1450 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1451 * @gl: The glock to thaw
1453 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1454 * so this has to result in the ref count being dropped by one.
1457 static void thaw_glock(struct gfs2_glock *gl)
1459 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1461 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1462 gfs2_glock_hold(gl);
1463 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1468 * clear_glock - look at a glock and see if we can free it from glock cache
1469 * @gl: the glock to look at
1473 static void clear_glock(struct gfs2_glock *gl)
1475 spin_lock(&lru_lock);
1476 if (!list_empty(&gl->gl_lru)) {
1477 list_del_init(&gl->gl_lru);
1478 atomic_dec(&lru_count);
1480 spin_unlock(&lru_lock);
1482 spin_lock(&gl->gl_spin);
1483 if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
1484 handle_callback(gl, LM_ST_UNLOCKED, 0);
1485 spin_unlock(&gl->gl_spin);
1486 gfs2_glock_hold(gl);
1487 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1492 * gfs2_glock_thaw - Thaw any frozen glocks
1493 * @sdp: The super block
1497 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1501 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1502 examine_bucket(thaw_glock, sdp, x);
1506 * gfs2_gl_hash_clear - Empty out the glock hash table
1507 * @sdp: the filesystem
1508 * @wait: wait until it's all gone
1510 * Called when unmounting the filesystem.
1513 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1523 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1524 if (examine_bucket(clear_glock, sdp, x))
1531 if (time_after_eq(jiffies,
1532 t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
1533 fs_warn(sdp, "Unmount seems to be stalled. "
1534 "Dumping lock state...\n");
1535 gfs2_dump_lockstate(sdp);
1539 down_write(&gfs2_umount_flush_sem);
1540 invalidate_inodes(sdp->sd_vfs);
1541 up_write(&gfs2_umount_flush_sem);
1544 flush_workqueue(glock_workqueue);
1545 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1546 gfs2_dump_lockstate(sdp);
1549 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1551 struct gfs2_glock *gl = ip->i_gl;
1554 ret = gfs2_truncatei_resume(ip);
1555 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1557 spin_lock(&gl->gl_spin);
1558 clear_bit(GLF_LOCK, &gl->gl_flags);
1560 spin_unlock(&gl->gl_spin);
1563 static const char *state2str(unsigned state)
1566 case LM_ST_UNLOCKED:
1570 case LM_ST_DEFERRED:
1572 case LM_ST_EXCLUSIVE:
1578 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1581 if (flags & LM_FLAG_TRY)
1583 if (flags & LM_FLAG_TRY_1CB)
1585 if (flags & LM_FLAG_NOEXP)
1587 if (flags & LM_FLAG_ANY)
1589 if (flags & LM_FLAG_PRIORITY)
1591 if (flags & GL_ASYNC)
1593 if (flags & GL_EXACT)
1595 if (flags & GL_NOCACHE)
1597 if (test_bit(HIF_HOLDER, &iflags))
1599 if (test_bit(HIF_WAIT, &iflags))
1601 if (test_bit(HIF_FIRST, &iflags))
1608 * dump_holder - print information about a glock holder
1609 * @seq: the seq_file struct
1610 * @gh: the glock holder
1612 * Returns: 0 on success, -ENOBUFS when we run out of space
1615 static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1617 struct task_struct *gh_owner = NULL;
1618 char buffer[KSYM_SYMBOL_LEN];
1621 sprint_symbol(buffer, gh->gh_ip);
1622 if (gh->gh_owner_pid)
1623 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1624 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
1625 state2str(gh->gh_state),
1626 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1628 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1629 gh_owner ? gh_owner->comm : "(ended)", buffer);
1633 static const char *gflags2str(char *buf, const unsigned long *gflags)
1636 if (test_bit(GLF_LOCK, gflags))
1638 if (test_bit(GLF_DEMOTE, gflags))
1640 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1642 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1644 if (test_bit(GLF_DIRTY, gflags))
1646 if (test_bit(GLF_LFLUSH, gflags))
1648 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1650 if (test_bit(GLF_REPLY_PENDING, gflags))
1652 if (test_bit(GLF_INITIAL, gflags))
1654 if (test_bit(GLF_FROZEN, gflags))
1661 * __dump_glock - print information about a glock
1662 * @seq: The seq_file struct
1665 * The file format is as follows:
1666 * One line per object, capital letters are used to indicate objects
1667 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1668 * other objects are indented by a single space and follow the glock to
1669 * which they are related. Fields are indicated by lower case letters
1670 * followed by a colon and the field value, except for strings which are in
1671 * [] so that its possible to see if they are composed of spaces for
1672 * example. The field's are n = number (id of the object), f = flags,
1673 * t = type, s = state, r = refcount, e = error, p = pid.
1675 * Returns: 0 on success, -ENOBUFS when we run out of space
1678 static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1680 const struct gfs2_glock_operations *glops = gl->gl_ops;
1681 unsigned long long dtime;
1682 const struct gfs2_holder *gh;
1683 char gflags_buf[32];
1686 dtime = jiffies - gl->gl_demote_time;
1687 dtime *= 1000000/HZ; /* demote time in uSec */
1688 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1690 gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu a:%d r:%d\n",
1691 state2str(gl->gl_state),
1692 gl->gl_name.ln_type,
1693 (unsigned long long)gl->gl_name.ln_number,
1694 gflags2str(gflags_buf, &gl->gl_flags),
1695 state2str(gl->gl_target),
1696 state2str(gl->gl_demote_state), dtime,
1697 atomic_read(&gl->gl_ail_count),
1698 atomic_read(&gl->gl_ref));
1700 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1701 error = dump_holder(seq, gh);
1705 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1706 error = glops->go_dump(seq, gl);
1711 static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1714 spin_lock(&gl->gl_spin);
1715 ret = __dump_glock(seq, gl);
1716 spin_unlock(&gl->gl_spin);
1721 * gfs2_dump_lockstate - print out the current lockstate
1722 * @sdp: the filesystem
1723 * @ub: the buffer to copy the information into
1725 * If @ub is NULL, dump the lockstate to the console.
1729 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
1731 struct gfs2_glock *gl;
1732 struct hlist_node *h;
1736 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1738 read_lock(gl_lock_addr(x));
1740 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
1741 if (gl->gl_sbd != sdp)
1744 error = dump_glock(NULL, gl);
1749 read_unlock(gl_lock_addr(x));
1760 int __init gfs2_glock_init(void)
1763 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1764 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
1766 #ifdef GL_HASH_LOCK_SZ
1767 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1768 rwlock_init(&gl_hash_locks[i]);
1772 glock_workqueue = create_workqueue("glock_workqueue");
1773 if (IS_ERR(glock_workqueue))
1774 return PTR_ERR(glock_workqueue);
1775 gfs2_delete_workqueue = create_workqueue("delete_workqueue");
1776 if (IS_ERR(gfs2_delete_workqueue)) {
1777 destroy_workqueue(glock_workqueue);
1778 return PTR_ERR(gfs2_delete_workqueue);
1781 register_shrinker(&glock_shrinker);
1786 void gfs2_glock_exit(void)
1788 unregister_shrinker(&glock_shrinker);
1789 destroy_workqueue(glock_workqueue);
1790 destroy_workqueue(gfs2_delete_workqueue);
1793 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1795 struct gfs2_glock *gl;
1798 read_lock(gl_lock_addr(gi->hash));
1801 gi->gl = hlist_entry(gl->gl_list.next,
1802 struct gfs2_glock, gl_list);
1804 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1805 struct gfs2_glock, gl_list);
1808 gfs2_glock_hold(gi->gl);
1809 read_unlock(gl_lock_addr(gi->hash));
1812 while (gi->gl == NULL) {
1814 if (gi->hash >= GFS2_GL_HASH_SIZE)
1816 read_lock(gl_lock_addr(gi->hash));
1817 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1818 struct gfs2_glock, gl_list);
1820 gfs2_glock_hold(gi->gl);
1821 read_unlock(gl_lock_addr(gi->hash));
1824 if (gi->sdp != gi->gl->gl_sbd)
1830 static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
1833 gfs2_glock_put(gi->gl);
1837 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1839 struct gfs2_glock_iter *gi = seq->private;
1845 if (gfs2_glock_iter_next(gi)) {
1846 gfs2_glock_iter_free(gi);
1854 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1857 struct gfs2_glock_iter *gi = seq->private;
1861 if (gfs2_glock_iter_next(gi)) {
1862 gfs2_glock_iter_free(gi);
1869 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1871 struct gfs2_glock_iter *gi = seq->private;
1872 gfs2_glock_iter_free(gi);
1875 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1877 return dump_glock(seq, iter_ptr);
1880 static const struct seq_operations gfs2_glock_seq_ops = {
1881 .start = gfs2_glock_seq_start,
1882 .next = gfs2_glock_seq_next,
1883 .stop = gfs2_glock_seq_stop,
1884 .show = gfs2_glock_seq_show,
1887 static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1889 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1890 sizeof(struct gfs2_glock_iter));
1892 struct seq_file *seq = file->private_data;
1893 struct gfs2_glock_iter *gi = seq->private;
1894 gi->sdp = inode->i_private;
1899 static const struct file_operations gfs2_debug_fops = {
1900 .owner = THIS_MODULE,
1901 .open = gfs2_debugfs_open,
1903 .llseek = seq_lseek,
1904 .release = seq_release_private,
1907 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1909 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1910 if (!sdp->debugfs_dir)
1912 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1914 sdp->debugfs_dir, sdp,
1916 if (!sdp->debugfs_dentry_glocks)
1922 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1924 if (sdp && sdp->debugfs_dir) {
1925 if (sdp->debugfs_dentry_glocks) {
1926 debugfs_remove(sdp->debugfs_dentry_glocks);
1927 sdp->debugfs_dentry_glocks = NULL;
1929 debugfs_remove(sdp->debugfs_dir);
1930 sdp->debugfs_dir = NULL;
1934 int gfs2_register_debugfs(void)
1936 gfs2_root = debugfs_create_dir("gfs2", NULL);
1937 return gfs2_root ? 0 : -ENOMEM;
1940 void gfs2_unregister_debugfs(void)
1942 debugfs_remove(gfs2_root);