2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 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 <asm/uaccess.h>
37 struct gfs2_gl_hash_bucket {
38 struct hlist_head hb_list;
41 typedef void (*glock_examiner) (struct gfs2_glock * gl);
43 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
44 static int dump_glock(struct gfs2_glock *gl);
45 static int dump_inode(struct gfs2_inode *ip);
46 static void gfs2_glock_xmote_th(struct gfs2_holder *gh);
47 static void gfs2_glock_drop_th(struct gfs2_glock *gl);
49 #define GFS2_GL_HASH_SHIFT 15
50 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
51 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
53 static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
56 * Despite what you might think, the numbers below are not arbitrary :-)
57 * They are taken from the ipv4 routing hash code, which is well tested
58 * and thus should be nearly optimal. Later on we might tweek the numbers
59 * but for now this should be fine.
61 * The reason for putting the locks in a separate array from the list heads
62 * is that we can have fewer locks than list heads and save memory. We use
63 * the same hash function for both, but with a different hash mask.
65 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
66 defined(CONFIG_PROVE_LOCKING)
69 # define GL_HASH_LOCK_SZ 256
72 # define GL_HASH_LOCK_SZ 4096
74 # define GL_HASH_LOCK_SZ 2048
76 # define GL_HASH_LOCK_SZ 1024
78 # define GL_HASH_LOCK_SZ 512
80 # define GL_HASH_LOCK_SZ 256
84 /* We never want more locks than chains */
85 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
86 # undef GL_HASH_LOCK_SZ
87 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
90 static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
92 static inline rwlock_t *gl_lock_addr(unsigned int x)
94 return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
96 #else /* not SMP, so no spinlocks required */
97 static inline rwlock_t *gl_lock_addr(unsigned int x)
104 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
105 * @actual: the current state of the lock
106 * @requested: the lock state that was requested by the caller
107 * @flags: the modifier flags passed in by the caller
109 * Returns: 1 if the locks are compatible, 0 otherwise
112 static inline int relaxed_state_ok(unsigned int actual, unsigned requested,
115 if (actual == requested)
118 if (flags & GL_EXACT)
121 if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED)
124 if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY))
131 * gl_hash() - Turn glock number into hash bucket number
132 * @lock: The glock number
134 * Returns: The number of the corresponding hash bucket
137 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
138 const struct lm_lockname *name)
142 h = jhash(&name->ln_number, sizeof(u64), 0);
143 h = jhash(&name->ln_type, sizeof(unsigned int), h);
144 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
145 h &= GFS2_GL_HASH_MASK;
151 * glock_free() - Perform a few checks and then release struct gfs2_glock
152 * @gl: The glock to release
154 * Also calls lock module to release its internal structure for this glock.
158 static void glock_free(struct gfs2_glock *gl)
160 struct gfs2_sbd *sdp = gl->gl_sbd;
161 struct inode *aspace = gl->gl_aspace;
163 gfs2_lm_put_lock(sdp, gl->gl_lock);
166 gfs2_aspace_put(aspace);
168 kmem_cache_free(gfs2_glock_cachep, gl);
172 * gfs2_glock_hold() - increment reference count on glock
173 * @gl: The glock to hold
177 void gfs2_glock_hold(struct gfs2_glock *gl)
179 atomic_inc(&gl->gl_ref);
183 * gfs2_glock_put() - Decrement reference count on glock
184 * @gl: The glock to put
188 int gfs2_glock_put(struct gfs2_glock *gl)
191 struct gfs2_sbd *sdp = gl->gl_sbd;
193 write_lock(gl_lock_addr(gl->gl_hash));
194 if (atomic_dec_and_test(&gl->gl_ref)) {
195 hlist_del(&gl->gl_list);
196 write_unlock(gl_lock_addr(gl->gl_hash));
197 BUG_ON(spin_is_locked(&gl->gl_spin));
198 gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);
199 gfs2_assert(sdp, list_empty(&gl->gl_reclaim));
200 gfs2_assert(sdp, list_empty(&gl->gl_holders));
201 gfs2_assert(sdp, list_empty(&gl->gl_waiters1));
202 gfs2_assert(sdp, list_empty(&gl->gl_waiters2));
203 gfs2_assert(sdp, list_empty(&gl->gl_waiters3));
208 write_unlock(gl_lock_addr(gl->gl_hash));
214 * queue_empty - check to see if a glock's queue is empty
216 * @head: the head of the queue to check
218 * This function protects the list in the event that a process already
219 * has a holder on the list and is adding a second holder for itself.
220 * The glmutex lock is what generally prevents processes from working
221 * on the same glock at once, but the special case of adding a second
222 * holder for yourself ("recursive" locking) doesn't involve locking
223 * glmutex, making the spin lock necessary.
225 * Returns: 1 if the queue is empty
228 static inline int queue_empty(struct gfs2_glock *gl, struct list_head *head)
231 spin_lock(&gl->gl_spin);
232 empty = list_empty(head);
233 spin_unlock(&gl->gl_spin);
238 * search_bucket() - Find struct gfs2_glock by lock number
239 * @bucket: the bucket to search
240 * @name: The lock name
242 * Returns: NULL, or the struct gfs2_glock with the requested number
245 static struct gfs2_glock *search_bucket(unsigned int hash,
246 const struct gfs2_sbd *sdp,
247 const struct lm_lockname *name)
249 struct gfs2_glock *gl;
250 struct hlist_node *h;
252 hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
253 if (!lm_name_equal(&gl->gl_name, name))
255 if (gl->gl_sbd != sdp)
258 atomic_inc(&gl->gl_ref);
267 * gfs2_glock_find() - Find glock by lock number
268 * @sdp: The GFS2 superblock
269 * @name: The lock name
271 * Returns: NULL, or the struct gfs2_glock with the requested number
274 static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
275 const struct lm_lockname *name)
277 unsigned int hash = gl_hash(sdp, name);
278 struct gfs2_glock *gl;
280 read_lock(gl_lock_addr(hash));
281 gl = search_bucket(hash, sdp, name);
282 read_unlock(gl_lock_addr(hash));
288 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
289 * @sdp: The GFS2 superblock
290 * @number: the lock number
291 * @glops: The glock_operations to use
292 * @create: If 0, don't create the glock if it doesn't exist
293 * @glp: the glock is returned here
295 * This does not lock a glock, just finds/creates structures for one.
300 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
301 const struct gfs2_glock_operations *glops, int create,
302 struct gfs2_glock **glp)
304 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
305 struct gfs2_glock *gl, *tmp;
306 unsigned int hash = gl_hash(sdp, &name);
309 read_lock(gl_lock_addr(hash));
310 gl = search_bucket(hash, sdp, &name);
311 read_unlock(gl_lock_addr(hash));
318 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
324 atomic_set(&gl->gl_ref, 1);
325 gl->gl_state = LM_ST_UNLOCKED;
330 gl->gl_req_gh = NULL;
331 gl->gl_req_bh = NULL;
333 gl->gl_stamp = jiffies;
334 gl->gl_object = NULL;
336 gl->gl_aspace = NULL;
337 lops_init_le(&gl->gl_le, &gfs2_glock_lops);
339 /* If this glock protects actual on-disk data or metadata blocks,
340 create a VFS inode to manage the pages/buffers holding them. */
341 if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
342 gl->gl_aspace = gfs2_aspace_get(sdp);
343 if (!gl->gl_aspace) {
349 error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock);
353 write_lock(gl_lock_addr(hash));
354 tmp = search_bucket(hash, sdp, &name);
356 write_unlock(gl_lock_addr(hash));
360 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
361 write_unlock(gl_lock_addr(hash));
370 gfs2_aspace_put(gl->gl_aspace);
372 kmem_cache_free(gfs2_glock_cachep, gl);
377 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
379 * @state: the state we're requesting
380 * @flags: the modifier flags
381 * @gh: the holder structure
385 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
386 struct gfs2_holder *gh)
388 INIT_LIST_HEAD(&gh->gh_list);
390 gh->gh_ip = (unsigned long)__builtin_return_address(0);
391 gh->gh_owner = current;
392 gh->gh_state = state;
393 gh->gh_flags = flags;
400 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
401 * @state: the state we're requesting
402 * @flags: the modifier flags
403 * @gh: the holder structure
405 * Don't mess with the glock.
409 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
411 gh->gh_state = state;
412 gh->gh_flags = flags;
413 gh->gh_iflags &= 1 << HIF_ALLOCED;
414 gh->gh_ip = (unsigned long)__builtin_return_address(0);
418 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
419 * @gh: the holder structure
423 void gfs2_holder_uninit(struct gfs2_holder *gh)
425 gfs2_glock_put(gh->gh_gl);
431 * gfs2_holder_get - get a struct gfs2_holder structure
433 * @state: the state we're requesting
434 * @flags: the modifier flags
437 * Figure out how big an impact this function has. Either:
438 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
439 * 2) Leave it like it is
441 * Returns: the holder structure, NULL on ENOMEM
444 static struct gfs2_holder *gfs2_holder_get(struct gfs2_glock *gl,
446 int flags, gfp_t gfp_flags)
448 struct gfs2_holder *gh;
450 gh = kmalloc(sizeof(struct gfs2_holder), gfp_flags);
454 gfs2_holder_init(gl, state, flags, gh);
455 set_bit(HIF_ALLOCED, &gh->gh_iflags);
456 gh->gh_ip = (unsigned long)__builtin_return_address(0);
461 * gfs2_holder_put - get rid of a struct gfs2_holder structure
462 * @gh: the holder structure
466 static void gfs2_holder_put(struct gfs2_holder *gh)
468 gfs2_holder_uninit(gh);
472 static void gfs2_holder_dispose_or_wake(struct gfs2_holder *gh)
474 if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) {
478 clear_bit(HIF_WAIT, &gh->gh_iflags);
480 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
483 static int holder_wait(void *word)
489 static void wait_on_holder(struct gfs2_holder *gh)
492 wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE);
496 * rq_mutex - process a mutex request in the queue
497 * @gh: the glock holder
499 * Returns: 1 if the queue is blocked
502 static int rq_mutex(struct gfs2_holder *gh)
504 struct gfs2_glock *gl = gh->gh_gl;
506 list_del_init(&gh->gh_list);
507 /* gh->gh_error never examined. */
508 set_bit(GLF_LOCK, &gl->gl_flags);
509 clear_bit(HIF_WAIT, &gh->gh_flags);
511 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
517 * rq_promote - process a promote request in the queue
518 * @gh: the glock holder
520 * Acquire a new inter-node lock, or change a lock state to more restrictive.
522 * Returns: 1 if the queue is blocked
525 static int rq_promote(struct gfs2_holder *gh)
527 struct gfs2_glock *gl = gh->gh_gl;
528 struct gfs2_sbd *sdp = gl->gl_sbd;
530 if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
531 if (list_empty(&gl->gl_holders)) {
533 set_bit(GLF_LOCK, &gl->gl_flags);
534 spin_unlock(&gl->gl_spin);
536 if (atomic_read(&sdp->sd_reclaim_count) >
537 gfs2_tune_get(sdp, gt_reclaim_limit) &&
538 !(gh->gh_flags & LM_FLAG_PRIORITY)) {
539 gfs2_reclaim_glock(sdp);
540 gfs2_reclaim_glock(sdp);
543 gfs2_glock_xmote_th(gh);
544 spin_lock(&gl->gl_spin);
549 if (list_empty(&gl->gl_holders)) {
550 set_bit(HIF_FIRST, &gh->gh_iflags);
551 set_bit(GLF_LOCK, &gl->gl_flags);
553 struct gfs2_holder *next_gh;
554 if (gh->gh_state == LM_ST_EXCLUSIVE)
556 next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder,
558 if (next_gh->gh_state == LM_ST_EXCLUSIVE)
562 list_move_tail(&gh->gh_list, &gl->gl_holders);
564 set_bit(HIF_HOLDER, &gh->gh_iflags);
566 gfs2_holder_dispose_or_wake(gh);
572 * rq_demote - process a demote request in the queue
573 * @gh: the glock holder
575 * Returns: 1 if the queue is blocked
578 static int rq_demote(struct gfs2_holder *gh)
580 struct gfs2_glock *gl = gh->gh_gl;
582 if (!list_empty(&gl->gl_holders))
585 if (gl->gl_state == gh->gh_state || gl->gl_state == LM_ST_UNLOCKED) {
586 list_del_init(&gh->gh_list);
588 spin_unlock(&gl->gl_spin);
589 gfs2_holder_dispose_or_wake(gh);
590 spin_lock(&gl->gl_spin);
593 set_bit(GLF_LOCK, &gl->gl_flags);
594 spin_unlock(&gl->gl_spin);
596 if (gh->gh_state == LM_ST_UNLOCKED ||
597 gl->gl_state != LM_ST_EXCLUSIVE)
598 gfs2_glock_drop_th(gl);
600 gfs2_glock_xmote_th(gh);
602 spin_lock(&gl->gl_spin);
609 * run_queue - process holder structures on a glock
613 static void run_queue(struct gfs2_glock *gl)
615 struct gfs2_holder *gh;
619 if (test_bit(GLF_LOCK, &gl->gl_flags))
622 if (!list_empty(&gl->gl_waiters1)) {
623 gh = list_entry(gl->gl_waiters1.next,
624 struct gfs2_holder, gh_list);
626 if (test_bit(HIF_MUTEX, &gh->gh_iflags))
627 blocked = rq_mutex(gh);
629 gfs2_assert_warn(gl->gl_sbd, 0);
631 } else if (!list_empty(&gl->gl_waiters2) &&
632 !test_bit(GLF_SKIP_WAITERS2, &gl->gl_flags)) {
633 gh = list_entry(gl->gl_waiters2.next,
634 struct gfs2_holder, gh_list);
636 if (test_bit(HIF_DEMOTE, &gh->gh_iflags))
637 blocked = rq_demote(gh);
639 gfs2_assert_warn(gl->gl_sbd, 0);
641 } else if (!list_empty(&gl->gl_waiters3)) {
642 gh = list_entry(gl->gl_waiters3.next,
643 struct gfs2_holder, gh_list);
645 if (test_bit(HIF_PROMOTE, &gh->gh_iflags))
646 blocked = rq_promote(gh);
648 gfs2_assert_warn(gl->gl_sbd, 0);
659 * gfs2_glmutex_lock - acquire a local lock on a glock
662 * Gives caller exclusive access to manipulate a glock structure.
665 static void gfs2_glmutex_lock(struct gfs2_glock *gl)
667 struct gfs2_holder gh;
669 gfs2_holder_init(gl, 0, 0, &gh);
670 set_bit(HIF_MUTEX, &gh.gh_iflags);
671 if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags))
674 spin_lock(&gl->gl_spin);
675 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
676 list_add_tail(&gh.gh_list, &gl->gl_waiters1);
678 gl->gl_owner = current;
679 gl->gl_ip = (unsigned long)__builtin_return_address(0);
680 clear_bit(HIF_WAIT, &gh.gh_iflags);
682 wake_up_bit(&gh.gh_iflags, HIF_WAIT);
684 spin_unlock(&gl->gl_spin);
687 gfs2_holder_uninit(&gh);
691 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
694 * Returns: 1 if the glock is acquired
697 static int gfs2_glmutex_trylock(struct gfs2_glock *gl)
701 spin_lock(&gl->gl_spin);
702 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
705 gl->gl_owner = current;
706 gl->gl_ip = (unsigned long)__builtin_return_address(0);
708 spin_unlock(&gl->gl_spin);
714 * gfs2_glmutex_unlock - release a local lock on a glock
719 static void gfs2_glmutex_unlock(struct gfs2_glock *gl)
721 spin_lock(&gl->gl_spin);
722 clear_bit(GLF_LOCK, &gl->gl_flags);
726 BUG_ON(!spin_is_locked(&gl->gl_spin));
727 spin_unlock(&gl->gl_spin);
731 * handle_callback - add a demote request to a lock's queue
733 * @state: the state the caller wants us to change to
735 * Note: This may fail sliently if we are out of memory.
738 static void handle_callback(struct gfs2_glock *gl, unsigned int state)
740 struct gfs2_holder *gh, *new_gh = NULL;
743 spin_lock(&gl->gl_spin);
745 list_for_each_entry(gh, &gl->gl_waiters2, gh_list) {
746 if (test_bit(HIF_DEMOTE, &gh->gh_iflags) &&
747 gl->gl_req_gh != gh) {
748 if (gh->gh_state != state)
749 gh->gh_state = LM_ST_UNLOCKED;
755 list_add_tail(&new_gh->gh_list, &gl->gl_waiters2);
758 spin_unlock(&gl->gl_spin);
760 new_gh = gfs2_holder_get(gl, state, LM_FLAG_TRY, GFP_NOFS);
763 set_bit(HIF_DEMOTE, &new_gh->gh_iflags);
764 set_bit(HIF_DEALLOC, &new_gh->gh_iflags);
765 set_bit(HIF_WAIT, &new_gh->gh_iflags);
771 spin_unlock(&gl->gl_spin);
774 gfs2_holder_put(new_gh);
778 * state_change - record that the glock is now in a different state
780 * @new_state the new state
784 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
788 held1 = (gl->gl_state != LM_ST_UNLOCKED);
789 held2 = (new_state != LM_ST_UNLOCKED);
791 if (held1 != held2) {
798 gl->gl_state = new_state;
802 * xmote_bh - Called after the lock module is done acquiring a lock
803 * @gl: The glock in question
804 * @ret: the int returned from the lock module
808 static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
810 struct gfs2_sbd *sdp = gl->gl_sbd;
811 const struct gfs2_glock_operations *glops = gl->gl_ops;
812 struct gfs2_holder *gh = gl->gl_req_gh;
813 int prev_state = gl->gl_state;
816 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
817 gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
818 gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC));
820 state_change(gl, ret & LM_OUT_ST_MASK);
822 if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) {
824 glops->go_inval(gl, DIO_METADATA);
825 } else if (gl->gl_state == LM_ST_DEFERRED) {
826 /* We might not want to do this here.
827 Look at moving to the inode glops. */
829 glops->go_inval(gl, 0);
832 /* Deal with each possible exit condition */
835 gl->gl_stamp = jiffies;
836 else if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
837 spin_lock(&gl->gl_spin);
838 list_del_init(&gh->gh_list);
840 spin_unlock(&gl->gl_spin);
841 } else if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) {
842 spin_lock(&gl->gl_spin);
843 list_del_init(&gh->gh_list);
844 if (gl->gl_state == gh->gh_state ||
845 gl->gl_state == LM_ST_UNLOCKED) {
848 if (gfs2_assert_warn(sdp, gh->gh_flags &
849 (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) == -1)
850 fs_warn(sdp, "ret = 0x%.8X\n", ret);
851 gh->gh_error = GLR_TRYFAILED;
853 spin_unlock(&gl->gl_spin);
855 if (ret & LM_OUT_CANCELED)
856 handle_callback(gl, LM_ST_UNLOCKED);
858 } else if (ret & LM_OUT_CANCELED) {
859 spin_lock(&gl->gl_spin);
860 list_del_init(&gh->gh_list);
861 gh->gh_error = GLR_CANCELED;
862 spin_unlock(&gl->gl_spin);
864 } else if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
865 spin_lock(&gl->gl_spin);
866 list_move_tail(&gh->gh_list, &gl->gl_holders);
868 set_bit(HIF_HOLDER, &gh->gh_iflags);
869 spin_unlock(&gl->gl_spin);
871 set_bit(HIF_FIRST, &gh->gh_iflags);
875 } else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
876 spin_lock(&gl->gl_spin);
877 list_del_init(&gh->gh_list);
878 gh->gh_error = GLR_TRYFAILED;
879 spin_unlock(&gl->gl_spin);
882 if (gfs2_assert_withdraw(sdp, 0) == -1)
883 fs_err(sdp, "ret = 0x%.8X\n", ret);
886 if (glops->go_xmote_bh)
887 glops->go_xmote_bh(gl);
890 spin_lock(&gl->gl_spin);
891 gl->gl_req_gh = NULL;
892 gl->gl_req_bh = NULL;
893 clear_bit(GLF_LOCK, &gl->gl_flags);
895 spin_unlock(&gl->gl_spin);
901 gfs2_holder_dispose_or_wake(gh);
905 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
906 * @gl: The glock in question
907 * @state: the requested state
908 * @flags: modifier flags to the lock call
912 void gfs2_glock_xmote_th(struct gfs2_holder *gh)
914 struct gfs2_glock *gl = gh->gh_gl;
915 struct gfs2_sbd *sdp = gl->gl_sbd;
916 int flags = gh->gh_flags;
917 unsigned state = gh->gh_state;
918 const struct gfs2_glock_operations *glops = gl->gl_ops;
919 int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB |
920 LM_FLAG_NOEXP | LM_FLAG_ANY |
922 unsigned int lck_ret;
924 if (glops->go_xmote_th)
925 glops->go_xmote_th(gl);
927 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
928 gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
929 gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED);
930 gfs2_assert_warn(sdp, state != gl->gl_state);
933 gl->gl_req_bh = xmote_bh;
935 lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags);
937 if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR)))
940 if (lck_ret & LM_OUT_ASYNC)
941 gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC);
943 xmote_bh(gl, lck_ret);
947 * drop_bh - Called after a lock module unlock completes
949 * @ret: the return status
951 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
952 * Doesn't drop the reference on the glock the top half took out
956 static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
958 struct gfs2_sbd *sdp = gl->gl_sbd;
959 const struct gfs2_glock_operations *glops = gl->gl_ops;
960 struct gfs2_holder *gh = gl->gl_req_gh;
962 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
963 gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
964 gfs2_assert_warn(sdp, !ret);
966 state_change(gl, LM_ST_UNLOCKED);
969 glops->go_inval(gl, DIO_METADATA);
972 spin_lock(&gl->gl_spin);
973 list_del_init(&gh->gh_list);
975 spin_unlock(&gl->gl_spin);
978 if (glops->go_drop_bh)
979 glops->go_drop_bh(gl);
981 spin_lock(&gl->gl_spin);
982 gl->gl_req_gh = NULL;
983 gl->gl_req_bh = NULL;
984 clear_bit(GLF_LOCK, &gl->gl_flags);
986 spin_unlock(&gl->gl_spin);
991 gfs2_holder_dispose_or_wake(gh);
995 * gfs2_glock_drop_th - call into the lock module to unlock a lock
1000 static void gfs2_glock_drop_th(struct gfs2_glock *gl)
1002 struct gfs2_sbd *sdp = gl->gl_sbd;
1003 const struct gfs2_glock_operations *glops = gl->gl_ops;
1006 if (glops->go_drop_th)
1007 glops->go_drop_th(gl);
1009 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
1010 gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
1011 gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED);
1013 gfs2_glock_hold(gl);
1014 gl->gl_req_bh = drop_bh;
1016 ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state);
1018 if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR)))
1024 gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC);
1028 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1029 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1031 * Don't cancel GL_NOCANCEL requests.
1034 static void do_cancels(struct gfs2_holder *gh)
1036 struct gfs2_glock *gl = gh->gh_gl;
1038 spin_lock(&gl->gl_spin);
1040 while (gl->gl_req_gh != gh &&
1041 !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
1042 !list_empty(&gh->gh_list)) {
1043 if (gl->gl_req_bh && !(gl->gl_req_gh &&
1044 (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) {
1045 spin_unlock(&gl->gl_spin);
1046 gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock);
1048 spin_lock(&gl->gl_spin);
1050 spin_unlock(&gl->gl_spin);
1052 spin_lock(&gl->gl_spin);
1056 spin_unlock(&gl->gl_spin);
1060 * glock_wait_internal - wait on a glock acquisition
1061 * @gh: the glock holder
1063 * Returns: 0 on success
1066 static int glock_wait_internal(struct gfs2_holder *gh)
1068 struct gfs2_glock *gl = gh->gh_gl;
1069 struct gfs2_sbd *sdp = gl->gl_sbd;
1070 const struct gfs2_glock_operations *glops = gl->gl_ops;
1072 if (test_bit(HIF_ABORTED, &gh->gh_iflags))
1075 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
1076 spin_lock(&gl->gl_spin);
1077 if (gl->gl_req_gh != gh &&
1078 !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
1079 !list_empty(&gh->gh_list)) {
1080 list_del_init(&gh->gh_list);
1081 gh->gh_error = GLR_TRYFAILED;
1083 spin_unlock(&gl->gl_spin);
1084 return gh->gh_error;
1086 spin_unlock(&gl->gl_spin);
1089 if (gh->gh_flags & LM_FLAG_PRIORITY)
1094 return gh->gh_error;
1096 gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags));
1097 gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state,
1100 if (test_bit(HIF_FIRST, &gh->gh_iflags)) {
1101 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
1103 if (glops->go_lock) {
1104 gh->gh_error = glops->go_lock(gh);
1106 spin_lock(&gl->gl_spin);
1107 list_del_init(&gh->gh_list);
1108 spin_unlock(&gl->gl_spin);
1112 spin_lock(&gl->gl_spin);
1113 gl->gl_req_gh = NULL;
1114 gl->gl_req_bh = NULL;
1115 clear_bit(GLF_LOCK, &gl->gl_flags);
1117 spin_unlock(&gl->gl_spin);
1120 return gh->gh_error;
1123 static inline struct gfs2_holder *
1124 find_holder_by_owner(struct list_head *head, struct task_struct *owner)
1126 struct gfs2_holder *gh;
1128 list_for_each_entry(gh, head, gh_list) {
1129 if (gh->gh_owner == owner)
1137 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1138 * @gh: the holder structure to add
1142 static void add_to_queue(struct gfs2_holder *gh)
1144 struct gfs2_glock *gl = gh->gh_gl;
1145 struct gfs2_holder *existing;
1147 BUG_ON(!gh->gh_owner);
1148 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
1151 existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner);
1153 print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
1154 printk(KERN_INFO "pid : %d\n", existing->gh_owner->pid);
1155 printk(KERN_INFO "lock type : %d lock state : %d\n",
1156 existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state);
1157 print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
1158 printk(KERN_INFO "pid : %d\n", gh->gh_owner->pid);
1159 printk(KERN_INFO "lock type : %d lock state : %d\n",
1160 gl->gl_name.ln_type, gl->gl_state);
1164 existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner);
1166 print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
1167 print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
1171 if (gh->gh_flags & LM_FLAG_PRIORITY)
1172 list_add(&gh->gh_list, &gl->gl_waiters3);
1174 list_add_tail(&gh->gh_list, &gl->gl_waiters3);
1178 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1179 * @gh: the holder structure
1181 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1183 * Returns: 0, GLR_TRYFAILED, or errno on failure
1186 int gfs2_glock_nq(struct gfs2_holder *gh)
1188 struct gfs2_glock *gl = gh->gh_gl;
1189 struct gfs2_sbd *sdp = gl->gl_sbd;
1193 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
1194 set_bit(HIF_ABORTED, &gh->gh_iflags);
1198 set_bit(HIF_PROMOTE, &gh->gh_iflags);
1200 spin_lock(&gl->gl_spin);
1203 spin_unlock(&gl->gl_spin);
1205 if (!(gh->gh_flags & GL_ASYNC)) {
1206 error = glock_wait_internal(gh);
1207 if (error == GLR_CANCELED) {
1217 * gfs2_glock_poll - poll to see if an async request has been completed
1220 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1223 int gfs2_glock_poll(struct gfs2_holder *gh)
1225 struct gfs2_glock *gl = gh->gh_gl;
1228 spin_lock(&gl->gl_spin);
1230 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1232 else if (list_empty(&gh->gh_list)) {
1233 if (gh->gh_error == GLR_CANCELED) {
1234 spin_unlock(&gl->gl_spin);
1236 if (gfs2_glock_nq(gh))
1243 spin_unlock(&gl->gl_spin);
1249 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1250 * @gh: the holder structure
1252 * Returns: 0, GLR_TRYFAILED, or errno on failure
1255 int gfs2_glock_wait(struct gfs2_holder *gh)
1259 error = glock_wait_internal(gh);
1260 if (error == GLR_CANCELED) {
1262 gh->gh_flags &= ~GL_ASYNC;
1263 error = gfs2_glock_nq(gh);
1270 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1271 * @gh: the glock holder
1275 void gfs2_glock_dq(struct gfs2_holder *gh)
1277 struct gfs2_glock *gl = gh->gh_gl;
1278 const struct gfs2_glock_operations *glops = gl->gl_ops;
1280 if (gh->gh_flags & GL_NOCACHE)
1281 handle_callback(gl, LM_ST_UNLOCKED);
1283 gfs2_glmutex_lock(gl);
1285 spin_lock(&gl->gl_spin);
1286 list_del_init(&gh->gh_list);
1288 if (list_empty(&gl->gl_holders)) {
1289 spin_unlock(&gl->gl_spin);
1291 if (glops->go_unlock)
1292 glops->go_unlock(gh);
1294 gl->gl_stamp = jiffies;
1296 spin_lock(&gl->gl_spin);
1299 clear_bit(GLF_LOCK, &gl->gl_flags);
1301 spin_unlock(&gl->gl_spin);
1305 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1306 * @gh: the holder structure
1310 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1313 gfs2_holder_uninit(gh);
1317 * gfs2_glock_nq_num - acquire a glock based on lock number
1318 * @sdp: the filesystem
1319 * @number: the lock number
1320 * @glops: the glock operations for the type of glock
1321 * @state: the state to acquire the glock in
1322 * @flags: modifier flags for the aquisition
1323 * @gh: the struct gfs2_holder
1328 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1329 const struct gfs2_glock_operations *glops,
1330 unsigned int state, int flags, struct gfs2_holder *gh)
1332 struct gfs2_glock *gl;
1335 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1337 error = gfs2_glock_nq_init(gl, state, flags, gh);
1345 * glock_compare - Compare two struct gfs2_glock structures for sorting
1346 * @arg_a: the first structure
1347 * @arg_b: the second structure
1351 static int glock_compare(const void *arg_a, const void *arg_b)
1353 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1354 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1355 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1356 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1358 if (a->ln_number > b->ln_number)
1360 if (a->ln_number < b->ln_number)
1362 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1367 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1368 * @num_gh: the number of structures
1369 * @ghs: an array of struct gfs2_holder structures
1371 * Returns: 0 on success (all glocks acquired),
1372 * errno on failure (no glocks acquired)
1375 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1376 struct gfs2_holder **p)
1381 for (x = 0; x < num_gh; x++)
1384 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1386 for (x = 0; x < num_gh; x++) {
1387 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1389 error = gfs2_glock_nq(p[x]);
1392 gfs2_glock_dq(p[x]);
1401 * gfs2_glock_nq_m - acquire multiple glocks
1402 * @num_gh: the number of structures
1403 * @ghs: an array of struct gfs2_holder structures
1405 * Figure out how big an impact this function has. Either:
1406 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1407 * 2) Forget async stuff and just call nq_m_sync()
1408 * 3) Leave it like it is
1410 * Returns: 0 on success (all glocks acquired),
1411 * errno on failure (no glocks acquired)
1414 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1418 int borked = 0, serious = 0;
1425 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1426 return gfs2_glock_nq(ghs);
1429 e = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL);
1433 for (x = 0; x < num_gh; x++) {
1434 ghs[x].gh_flags |= LM_FLAG_TRY | GL_ASYNC;
1435 error = gfs2_glock_nq(&ghs[x]);
1444 for (x = 0; x < num_gh; x++) {
1445 error = e[x] = glock_wait_internal(&ghs[x]);
1448 if (error != GLR_TRYFAILED && error != GLR_CANCELED)
1458 for (x = 0; x < num_gh; x++)
1460 gfs2_glock_dq(&ghs[x]);
1465 for (x = 0; x < num_gh; x++)
1466 gfs2_holder_reinit(ghs[x].gh_state, ghs[x].gh_flags,
1468 error = nq_m_sync(num_gh, ghs, (struct gfs2_holder **)e);
1477 * gfs2_glock_dq_m - release multiple glocks
1478 * @num_gh: the number of structures
1479 * @ghs: an array of struct gfs2_holder structures
1483 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1487 for (x = 0; x < num_gh; x++)
1488 gfs2_glock_dq(&ghs[x]);
1492 * gfs2_glock_dq_uninit_m - release multiple glocks
1493 * @num_gh: the number of structures
1494 * @ghs: an array of struct gfs2_holder structures
1498 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1502 for (x = 0; x < num_gh; x++)
1503 gfs2_glock_dq_uninit(&ghs[x]);
1507 * gfs2_lvb_hold - attach a LVB from a glock
1508 * @gl: The glock in question
1512 int gfs2_lvb_hold(struct gfs2_glock *gl)
1516 gfs2_glmutex_lock(gl);
1518 if (!atomic_read(&gl->gl_lvb_count)) {
1519 error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
1521 gfs2_glmutex_unlock(gl);
1524 gfs2_glock_hold(gl);
1526 atomic_inc(&gl->gl_lvb_count);
1528 gfs2_glmutex_unlock(gl);
1534 * gfs2_lvb_unhold - detach a LVB from a glock
1535 * @gl: The glock in question
1539 void gfs2_lvb_unhold(struct gfs2_glock *gl)
1541 gfs2_glock_hold(gl);
1542 gfs2_glmutex_lock(gl);
1544 gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
1545 if (atomic_dec_and_test(&gl->gl_lvb_count)) {
1546 gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb);
1551 gfs2_glmutex_unlock(gl);
1555 static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
1558 struct gfs2_glock *gl;
1560 gl = gfs2_glock_find(sdp, name);
1564 handle_callback(gl, state);
1566 spin_lock(&gl->gl_spin);
1568 spin_unlock(&gl->gl_spin);
1574 * gfs2_glock_cb - Callback used by locking module
1575 * @sdp: Pointer to the superblock
1576 * @type: Type of callback
1577 * @data: Type dependent data pointer
1579 * Called by the locking module when it wants to tell us something.
1580 * Either we need to drop a lock, one of our ASYNC requests completed, or
1581 * a journal from another client needs to be recovered.
1584 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
1586 struct gfs2_sbd *sdp = cb_data;
1590 blocking_cb(sdp, data, LM_ST_UNLOCKED);
1594 blocking_cb(sdp, data, LM_ST_DEFERRED);
1598 blocking_cb(sdp, data, LM_ST_SHARED);
1602 struct lm_async_cb *async = data;
1603 struct gfs2_glock *gl;
1605 gl = gfs2_glock_find(sdp, &async->lc_name);
1606 if (gfs2_assert_warn(sdp, gl))
1608 if (!gfs2_assert_warn(sdp, gl->gl_req_bh))
1609 gl->gl_req_bh(gl, async->lc_ret);
1614 case LM_CB_NEED_RECOVERY:
1615 gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data);
1616 if (sdp->sd_recoverd_process)
1617 wake_up_process(sdp->sd_recoverd_process);
1620 case LM_CB_DROPLOCKS:
1621 gfs2_gl_hash_clear(sdp, NO_WAIT);
1622 gfs2_quota_scan(sdp);
1626 gfs2_assert_warn(sdp, 0);
1632 * demote_ok - Check to see if it's ok to unlock a glock
1635 * Returns: 1 if it's ok
1638 static int demote_ok(struct gfs2_glock *gl)
1640 const struct gfs2_glock_operations *glops = gl->gl_ops;
1643 if (test_bit(GLF_STICKY, &gl->gl_flags))
1645 else if (glops->go_demote_ok)
1646 demote = glops->go_demote_ok(gl);
1652 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1657 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
1659 struct gfs2_sbd *sdp = gl->gl_sbd;
1661 spin_lock(&sdp->sd_reclaim_lock);
1662 if (list_empty(&gl->gl_reclaim)) {
1663 gfs2_glock_hold(gl);
1664 list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
1665 atomic_inc(&sdp->sd_reclaim_count);
1667 spin_unlock(&sdp->sd_reclaim_lock);
1669 wake_up(&sdp->sd_reclaim_wq);
1673 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1674 * @sdp: the filesystem
1676 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1677 * different glock and we notice that there are a lot of glocks in the
1682 void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
1684 struct gfs2_glock *gl;
1686 spin_lock(&sdp->sd_reclaim_lock);
1687 if (list_empty(&sdp->sd_reclaim_list)) {
1688 spin_unlock(&sdp->sd_reclaim_lock);
1691 gl = list_entry(sdp->sd_reclaim_list.next,
1692 struct gfs2_glock, gl_reclaim);
1693 list_del_init(&gl->gl_reclaim);
1694 spin_unlock(&sdp->sd_reclaim_lock);
1696 atomic_dec(&sdp->sd_reclaim_count);
1697 atomic_inc(&sdp->sd_reclaimed);
1699 if (gfs2_glmutex_trylock(gl)) {
1700 if (queue_empty(gl, &gl->gl_holders) &&
1701 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1702 handle_callback(gl, LM_ST_UNLOCKED);
1703 gfs2_glmutex_unlock(gl);
1710 * examine_bucket - Call a function for glock in a hash bucket
1711 * @examiner: the function
1712 * @sdp: the filesystem
1713 * @bucket: the bucket
1715 * Returns: 1 if the bucket has entries
1718 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
1721 struct gfs2_glock *gl, *prev = NULL;
1722 int has_entries = 0;
1723 struct hlist_head *head = &gl_hash_table[hash].hb_list;
1725 read_lock(gl_lock_addr(hash));
1726 /* Can't use hlist_for_each_entry - don't want prefetch here */
1727 if (hlist_empty(head))
1729 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1731 if (gl->gl_sbd == sdp) {
1732 gfs2_glock_hold(gl);
1733 read_unlock(gl_lock_addr(hash));
1735 gfs2_glock_put(prev);
1739 read_lock(gl_lock_addr(hash));
1741 if (gl->gl_list.next == NULL)
1743 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
1746 read_unlock(gl_lock_addr(hash));
1748 gfs2_glock_put(prev);
1753 * scan_glock - look at a glock and see if we can reclaim it
1754 * @gl: the glock to look at
1758 static void scan_glock(struct gfs2_glock *gl)
1760 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
1763 if (gfs2_glmutex_trylock(gl)) {
1764 if (queue_empty(gl, &gl->gl_holders) &&
1765 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1767 gfs2_glmutex_unlock(gl);
1772 gfs2_glmutex_unlock(gl);
1773 gfs2_glock_schedule_for_reclaim(gl);
1777 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1778 * @sdp: the filesystem
1782 void gfs2_scand_internal(struct gfs2_sbd *sdp)
1786 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1787 examine_bucket(scan_glock, sdp, x);
1791 * clear_glock - look at a glock and see if we can free it from glock cache
1792 * @gl: the glock to look at
1796 static void clear_glock(struct gfs2_glock *gl)
1798 struct gfs2_sbd *sdp = gl->gl_sbd;
1801 spin_lock(&sdp->sd_reclaim_lock);
1802 if (!list_empty(&gl->gl_reclaim)) {
1803 list_del_init(&gl->gl_reclaim);
1804 atomic_dec(&sdp->sd_reclaim_count);
1805 spin_unlock(&sdp->sd_reclaim_lock);
1806 released = gfs2_glock_put(gl);
1807 gfs2_assert(sdp, !released);
1809 spin_unlock(&sdp->sd_reclaim_lock);
1812 if (gfs2_glmutex_trylock(gl)) {
1813 if (queue_empty(gl, &gl->gl_holders) &&
1814 gl->gl_state != LM_ST_UNLOCKED)
1815 handle_callback(gl, LM_ST_UNLOCKED);
1816 gfs2_glmutex_unlock(gl);
1821 * gfs2_gl_hash_clear - Empty out the glock hash table
1822 * @sdp: the filesystem
1823 * @wait: wait until it's all gone
1825 * Called when unmounting the filesystem, or when inter-node lock manager
1826 * requests DROPLOCKS because it is running out of capacity.
1829 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
1839 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1840 if (examine_bucket(clear_glock, sdp, x))
1847 if (time_after_eq(jiffies,
1848 t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
1849 fs_warn(sdp, "Unmount seems to be stalled. "
1850 "Dumping lock state...\n");
1851 gfs2_dump_lockstate(sdp);
1855 invalidate_inodes(sdp->sd_vfs);
1861 * Diagnostic routines to help debug distributed deadlock
1865 * dump_holder - print information about a glock holder
1866 * @str: a string naming the type of holder
1867 * @gh: the glock holder
1869 * Returns: 0 on success, -ENOBUFS when we run out of space
1872 static int dump_holder(char *str, struct gfs2_holder *gh)
1875 int error = -ENOBUFS;
1877 printk(KERN_INFO " %s\n", str);
1878 printk(KERN_INFO " owner = %ld\n",
1879 (gh->gh_owner) ? (long)gh->gh_owner->pid : -1);
1880 printk(KERN_INFO " gh_state = %u\n", gh->gh_state);
1881 printk(KERN_INFO " gh_flags =");
1882 for (x = 0; x < 32; x++)
1883 if (gh->gh_flags & (1 << x))
1886 printk(KERN_INFO " error = %d\n", gh->gh_error);
1887 printk(KERN_INFO " gh_iflags =");
1888 for (x = 0; x < 32; x++)
1889 if (test_bit(x, &gh->gh_iflags))
1892 print_symbol(KERN_INFO " initialized at: %s\n", gh->gh_ip);
1900 * dump_inode - print information about an inode
1903 * Returns: 0 on success, -ENOBUFS when we run out of space
1906 static int dump_inode(struct gfs2_inode *ip)
1909 int error = -ENOBUFS;
1911 printk(KERN_INFO " Inode:\n");
1912 printk(KERN_INFO " num = %llu %llu\n",
1913 (unsigned long long)ip->i_num.no_formal_ino,
1914 (unsigned long long)ip->i_num.no_addr);
1915 printk(KERN_INFO " type = %u\n", IF2DT(ip->i_inode.i_mode));
1916 printk(KERN_INFO " i_flags =");
1917 for (x = 0; x < 32; x++)
1918 if (test_bit(x, &ip->i_flags))
1928 * dump_glock - print information about a glock
1930 * @count: where we are in the buffer
1932 * Returns: 0 on success, -ENOBUFS when we run out of space
1935 static int dump_glock(struct gfs2_glock *gl)
1937 struct gfs2_holder *gh;
1939 int error = -ENOBUFS;
1941 spin_lock(&gl->gl_spin);
1943 printk(KERN_INFO "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type,
1944 (unsigned long long)gl->gl_name.ln_number);
1945 printk(KERN_INFO " gl_flags =");
1946 for (x = 0; x < 32; x++) {
1947 if (test_bit(x, &gl->gl_flags))
1951 printk(KERN_INFO " gl_ref = %d\n", atomic_read(&gl->gl_ref));
1952 printk(KERN_INFO " gl_state = %u\n", gl->gl_state);
1953 printk(KERN_INFO " gl_owner = %s\n", gl->gl_owner->comm);
1954 print_symbol(KERN_INFO " gl_ip = %s\n", gl->gl_ip);
1955 printk(KERN_INFO " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no");
1956 printk(KERN_INFO " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no");
1957 printk(KERN_INFO " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count));
1958 printk(KERN_INFO " object = %s\n", (gl->gl_object) ? "yes" : "no");
1959 printk(KERN_INFO " le = %s\n",
1960 (list_empty(&gl->gl_le.le_list)) ? "no" : "yes");
1961 printk(KERN_INFO " reclaim = %s\n",
1962 (list_empty(&gl->gl_reclaim)) ? "no" : "yes");
1964 printk(KERN_INFO " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace,
1965 gl->gl_aspace->i_mapping->nrpages);
1967 printk(KERN_INFO " aspace = no\n");
1968 printk(KERN_INFO " ail = %d\n", atomic_read(&gl->gl_ail_count));
1969 if (gl->gl_req_gh) {
1970 error = dump_holder("Request", gl->gl_req_gh);
1974 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1975 error = dump_holder("Holder", gh);
1979 list_for_each_entry(gh, &gl->gl_waiters1, gh_list) {
1980 error = dump_holder("Waiter1", gh);
1984 list_for_each_entry(gh, &gl->gl_waiters2, gh_list) {
1985 error = dump_holder("Waiter2", gh);
1989 list_for_each_entry(gh, &gl->gl_waiters3, gh_list) {
1990 error = dump_holder("Waiter3", gh);
1994 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) {
1995 if (!test_bit(GLF_LOCK, &gl->gl_flags) &&
1996 list_empty(&gl->gl_holders)) {
1997 error = dump_inode(gl->gl_object);
2002 printk(KERN_INFO " Inode: busy\n");
2009 spin_unlock(&gl->gl_spin);
2014 * gfs2_dump_lockstate - print out the current lockstate
2015 * @sdp: the filesystem
2016 * @ub: the buffer to copy the information into
2018 * If @ub is NULL, dump the lockstate to the console.
2022 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
2024 struct gfs2_glock *gl;
2025 struct hlist_node *h;
2029 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
2031 read_lock(gl_lock_addr(x));
2033 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
2034 if (gl->gl_sbd != sdp)
2037 error = dump_glock(gl);
2042 read_unlock(gl_lock_addr(x));
2052 int __init gfs2_glock_init(void)
2055 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
2056 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
2058 #ifdef GL_HASH_LOCK_SZ
2059 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
2060 rwlock_init(&gl_hash_locks[i]);