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 <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/module.h>
29 #include <linux/kallsyms.h>
43 struct gfs2_gl_hash_bucket {
44 struct hlist_head hb_list;
48 int hash; /* hash bucket index */
49 struct gfs2_sbd *sdp; /* incore superblock */
50 struct gfs2_glock *gl; /* current glock struct */
51 struct hlist_head *hb_list; /* current hash bucket ptr */
52 struct seq_file *seq; /* sequence file for debugfs */
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 glock_iter *gi, struct gfs2_glock *gl);
60 static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh);
61 static void gfs2_glock_drop_th(struct gfs2_glock *gl);
62 static DECLARE_RWSEM(gfs2_umount_flush_sem);
63 static struct dentry *gfs2_root;
65 #define GFS2_GL_HASH_SHIFT 15
66 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
67 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
69 static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
70 static struct dentry *gfs2_root;
73 * Despite what you might think, the numbers below are not arbitrary :-)
74 * They are taken from the ipv4 routing hash code, which is well tested
75 * and thus should be nearly optimal. Later on we might tweek the numbers
76 * but for now this should be fine.
78 * The reason for putting the locks in a separate array from the list heads
79 * is that we can have fewer locks than list heads and save memory. We use
80 * the same hash function for both, but with a different hash mask.
82 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
83 defined(CONFIG_PROVE_LOCKING)
86 # define GL_HASH_LOCK_SZ 256
89 # define GL_HASH_LOCK_SZ 4096
91 # define GL_HASH_LOCK_SZ 2048
93 # define GL_HASH_LOCK_SZ 1024
95 # define GL_HASH_LOCK_SZ 512
97 # define GL_HASH_LOCK_SZ 256
101 /* We never want more locks than chains */
102 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
103 # undef GL_HASH_LOCK_SZ
104 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
107 static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
109 static inline rwlock_t *gl_lock_addr(unsigned int x)
111 return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
113 #else /* not SMP, so no spinlocks required */
114 static inline rwlock_t *gl_lock_addr(unsigned int x)
121 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
122 * @actual: the current state of the lock
123 * @requested: the lock state that was requested by the caller
124 * @flags: the modifier flags passed in by the caller
126 * Returns: 1 if the locks are compatible, 0 otherwise
129 static inline int relaxed_state_ok(unsigned int actual, unsigned requested,
132 if (actual == requested)
135 if (flags & GL_EXACT)
138 if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED)
141 if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY))
148 * gl_hash() - Turn glock number into hash bucket number
149 * @lock: The glock number
151 * Returns: The number of the corresponding hash bucket
154 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
155 const struct lm_lockname *name)
159 h = jhash(&name->ln_number, sizeof(u64), 0);
160 h = jhash(&name->ln_type, sizeof(unsigned int), h);
161 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
162 h &= GFS2_GL_HASH_MASK;
168 * glock_free() - Perform a few checks and then release struct gfs2_glock
169 * @gl: The glock to release
171 * Also calls lock module to release its internal structure for this glock.
175 static void glock_free(struct gfs2_glock *gl)
177 struct gfs2_sbd *sdp = gl->gl_sbd;
178 struct inode *aspace = gl->gl_aspace;
180 gfs2_lm_put_lock(sdp, gl->gl_lock);
183 gfs2_aspace_put(aspace);
185 kmem_cache_free(gfs2_glock_cachep, gl);
189 * gfs2_glock_hold() - increment reference count on glock
190 * @gl: The glock to hold
194 void gfs2_glock_hold(struct gfs2_glock *gl)
196 atomic_inc(&gl->gl_ref);
200 * gfs2_glock_put() - Decrement reference count on glock
201 * @gl: The glock to put
205 int gfs2_glock_put(struct gfs2_glock *gl)
208 struct gfs2_sbd *sdp = gl->gl_sbd;
210 write_lock(gl_lock_addr(gl->gl_hash));
211 if (atomic_dec_and_test(&gl->gl_ref)) {
212 hlist_del(&gl->gl_list);
213 write_unlock(gl_lock_addr(gl->gl_hash));
214 BUG_ON(spin_is_locked(&gl->gl_spin));
215 gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);
216 gfs2_assert(sdp, list_empty(&gl->gl_reclaim));
217 gfs2_assert(sdp, list_empty(&gl->gl_holders));
218 gfs2_assert(sdp, list_empty(&gl->gl_waiters1));
219 gfs2_assert(sdp, list_empty(&gl->gl_waiters3));
224 write_unlock(gl_lock_addr(gl->gl_hash));
230 * search_bucket() - Find struct gfs2_glock by lock number
231 * @bucket: the bucket to search
232 * @name: The lock name
234 * Returns: NULL, or the struct gfs2_glock with the requested number
237 static struct gfs2_glock *search_bucket(unsigned int hash,
238 const struct gfs2_sbd *sdp,
239 const struct lm_lockname *name)
241 struct gfs2_glock *gl;
242 struct hlist_node *h;
244 hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
245 if (!lm_name_equal(&gl->gl_name, name))
247 if (gl->gl_sbd != sdp)
250 atomic_inc(&gl->gl_ref);
259 * gfs2_glock_find() - Find glock by lock number
260 * @sdp: The GFS2 superblock
261 * @name: The lock name
263 * Returns: NULL, or the struct gfs2_glock with the requested number
266 static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
267 const struct lm_lockname *name)
269 unsigned int hash = gl_hash(sdp, name);
270 struct gfs2_glock *gl;
272 read_lock(gl_lock_addr(hash));
273 gl = search_bucket(hash, sdp, name);
274 read_unlock(gl_lock_addr(hash));
280 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
281 * @sdp: The GFS2 superblock
282 * @number: the lock number
283 * @glops: The glock_operations to use
284 * @create: If 0, don't create the glock if it doesn't exist
285 * @glp: the glock is returned here
287 * This does not lock a glock, just finds/creates structures for one.
292 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
293 const struct gfs2_glock_operations *glops, int create,
294 struct gfs2_glock **glp)
296 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
297 struct gfs2_glock *gl, *tmp;
298 unsigned int hash = gl_hash(sdp, &name);
301 read_lock(gl_lock_addr(hash));
302 gl = search_bucket(hash, sdp, &name);
303 read_unlock(gl_lock_addr(hash));
310 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
316 atomic_set(&gl->gl_ref, 1);
317 gl->gl_state = LM_ST_UNLOCKED;
319 gl->gl_owner_pid = 0;
322 gl->gl_req_gh = NULL;
323 gl->gl_req_bh = NULL;
325 gl->gl_stamp = jiffies;
326 gl->gl_object = NULL;
328 gl->gl_aspace = NULL;
329 lops_init_le(&gl->gl_le, &gfs2_glock_lops);
331 /* If this glock protects actual on-disk data or metadata blocks,
332 create a VFS inode to manage the pages/buffers holding them. */
333 if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
334 gl->gl_aspace = gfs2_aspace_get(sdp);
335 if (!gl->gl_aspace) {
341 error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock);
345 write_lock(gl_lock_addr(hash));
346 tmp = search_bucket(hash, sdp, &name);
348 write_unlock(gl_lock_addr(hash));
352 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
353 write_unlock(gl_lock_addr(hash));
362 gfs2_aspace_put(gl->gl_aspace);
364 kmem_cache_free(gfs2_glock_cachep, gl);
369 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
371 * @state: the state we're requesting
372 * @flags: the modifier flags
373 * @gh: the holder structure
377 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
378 struct gfs2_holder *gh)
380 INIT_LIST_HEAD(&gh->gh_list);
382 gh->gh_ip = (unsigned long)__builtin_return_address(0);
383 gh->gh_owner_pid = current->pid;
384 gh->gh_state = state;
385 gh->gh_flags = flags;
392 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
393 * @state: the state we're requesting
394 * @flags: the modifier flags
395 * @gh: the holder structure
397 * Don't mess with the glock.
401 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
403 gh->gh_state = state;
404 gh->gh_flags = flags;
406 gh->gh_ip = (unsigned long)__builtin_return_address(0);
410 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
411 * @gh: the holder structure
415 void gfs2_holder_uninit(struct gfs2_holder *gh)
417 gfs2_glock_put(gh->gh_gl);
422 static void gfs2_holder_wake(struct gfs2_holder *gh)
424 clear_bit(HIF_WAIT, &gh->gh_iflags);
425 smp_mb__after_clear_bit();
426 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
429 static int just_schedule(void *word)
435 static void wait_on_holder(struct gfs2_holder *gh)
438 wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
441 static void gfs2_demote_wake(struct gfs2_glock *gl)
443 clear_bit(GLF_DEMOTE, &gl->gl_flags);
444 smp_mb__after_clear_bit();
445 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
448 static void wait_on_demote(struct gfs2_glock *gl)
451 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
455 * rq_mutex - process a mutex request in the queue
456 * @gh: the glock holder
458 * Returns: 1 if the queue is blocked
461 static int rq_mutex(struct gfs2_holder *gh)
463 struct gfs2_glock *gl = gh->gh_gl;
465 list_del_init(&gh->gh_list);
466 /* gh->gh_error never examined. */
467 set_bit(GLF_LOCK, &gl->gl_flags);
468 clear_bit(HIF_WAIT, &gh->gh_iflags);
470 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
476 * rq_promote - process a promote request in the queue
477 * @gh: the glock holder
479 * Acquire a new inter-node lock, or change a lock state to more restrictive.
481 * Returns: 1 if the queue is blocked
484 static int rq_promote(struct gfs2_holder *gh)
486 struct gfs2_glock *gl = gh->gh_gl;
487 struct gfs2_sbd *sdp = gl->gl_sbd;
489 if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
490 if (list_empty(&gl->gl_holders)) {
492 set_bit(GLF_LOCK, &gl->gl_flags);
493 spin_unlock(&gl->gl_spin);
495 if (atomic_read(&sdp->sd_reclaim_count) >
496 gfs2_tune_get(sdp, gt_reclaim_limit) &&
497 !(gh->gh_flags & LM_FLAG_PRIORITY)) {
498 gfs2_reclaim_glock(sdp);
499 gfs2_reclaim_glock(sdp);
502 gfs2_glock_xmote_th(gh->gh_gl, gh);
503 spin_lock(&gl->gl_spin);
508 if (list_empty(&gl->gl_holders)) {
509 set_bit(HIF_FIRST, &gh->gh_iflags);
510 set_bit(GLF_LOCK, &gl->gl_flags);
512 struct gfs2_holder *next_gh;
513 if (gh->gh_state == LM_ST_EXCLUSIVE)
515 next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder,
517 if (next_gh->gh_state == LM_ST_EXCLUSIVE)
521 list_move_tail(&gh->gh_list, &gl->gl_holders);
523 set_bit(HIF_HOLDER, &gh->gh_iflags);
525 gfs2_holder_wake(gh);
531 * rq_demote - process a demote request in the queue
532 * @gh: the glock holder
534 * Returns: 1 if the queue is blocked
537 static int rq_demote(struct gfs2_glock *gl)
539 if (!list_empty(&gl->gl_holders))
542 if (gl->gl_state == gl->gl_demote_state ||
543 gl->gl_state == LM_ST_UNLOCKED) {
544 gfs2_demote_wake(gl);
547 set_bit(GLF_LOCK, &gl->gl_flags);
548 if (gl->gl_demote_state == LM_ST_UNLOCKED ||
549 gl->gl_state != LM_ST_EXCLUSIVE) {
550 spin_unlock(&gl->gl_spin);
551 gfs2_glock_drop_th(gl);
553 spin_unlock(&gl->gl_spin);
554 gfs2_glock_xmote_th(gl, NULL);
556 spin_lock(&gl->gl_spin);
562 * run_queue - process holder structures on a glock
566 static void run_queue(struct gfs2_glock *gl)
568 struct gfs2_holder *gh;
572 if (test_bit(GLF_LOCK, &gl->gl_flags))
575 if (!list_empty(&gl->gl_waiters1)) {
576 gh = list_entry(gl->gl_waiters1.next,
577 struct gfs2_holder, gh_list);
579 if (test_bit(HIF_MUTEX, &gh->gh_iflags))
580 blocked = rq_mutex(gh);
582 gfs2_assert_warn(gl->gl_sbd, 0);
584 } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
585 blocked = rq_demote(gl);
586 } else if (!list_empty(&gl->gl_waiters3)) {
587 gh = list_entry(gl->gl_waiters3.next,
588 struct gfs2_holder, gh_list);
590 if (test_bit(HIF_PROMOTE, &gh->gh_iflags))
591 blocked = rq_promote(gh);
593 gfs2_assert_warn(gl->gl_sbd, 0);
604 * gfs2_glmutex_lock - acquire a local lock on a glock
607 * Gives caller exclusive access to manipulate a glock structure.
610 static void gfs2_glmutex_lock(struct gfs2_glock *gl)
612 struct gfs2_holder gh;
614 gfs2_holder_init(gl, 0, 0, &gh);
615 set_bit(HIF_MUTEX, &gh.gh_iflags);
616 if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags))
619 spin_lock(&gl->gl_spin);
620 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
621 list_add_tail(&gh.gh_list, &gl->gl_waiters1);
623 gl->gl_owner_pid = current->pid;
624 gl->gl_ip = (unsigned long)__builtin_return_address(0);
625 clear_bit(HIF_WAIT, &gh.gh_iflags);
627 wake_up_bit(&gh.gh_iflags, HIF_WAIT);
629 spin_unlock(&gl->gl_spin);
632 gfs2_holder_uninit(&gh);
636 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
639 * Returns: 1 if the glock is acquired
642 static int gfs2_glmutex_trylock(struct gfs2_glock *gl)
646 spin_lock(&gl->gl_spin);
647 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
650 gl->gl_owner_pid = current->pid;
651 gl->gl_ip = (unsigned long)__builtin_return_address(0);
653 spin_unlock(&gl->gl_spin);
659 * gfs2_glmutex_unlock - release a local lock on a glock
664 static void gfs2_glmutex_unlock(struct gfs2_glock *gl)
666 spin_lock(&gl->gl_spin);
667 clear_bit(GLF_LOCK, &gl->gl_flags);
668 gl->gl_owner_pid = 0;
671 BUG_ON(!spin_is_locked(&gl->gl_spin));
672 spin_unlock(&gl->gl_spin);
676 * handle_callback - process a demote request
678 * @state: the state the caller wants us to change to
680 * There are only two requests that we are going to see in actual
681 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
684 static void handle_callback(struct gfs2_glock *gl, unsigned int state, int remote)
686 spin_lock(&gl->gl_spin);
687 if (test_and_set_bit(GLF_DEMOTE, &gl->gl_flags) == 0) {
688 gl->gl_demote_state = state;
689 gl->gl_demote_time = jiffies;
690 if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
692 struct inode *inode = igrab(gl->gl_object);
693 spin_unlock(&gl->gl_spin);
695 d_prune_aliases(inode);
700 } else if (gl->gl_demote_state != LM_ST_UNLOCKED) {
701 gl->gl_demote_state = state;
703 spin_unlock(&gl->gl_spin);
707 * state_change - record that the glock is now in a different state
709 * @new_state the new state
713 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
717 held1 = (gl->gl_state != LM_ST_UNLOCKED);
718 held2 = (new_state != LM_ST_UNLOCKED);
720 if (held1 != held2) {
727 gl->gl_state = new_state;
731 * xmote_bh - Called after the lock module is done acquiring a lock
732 * @gl: The glock in question
733 * @ret: the int returned from the lock module
737 static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
739 struct gfs2_sbd *sdp = gl->gl_sbd;
740 const struct gfs2_glock_operations *glops = gl->gl_ops;
741 struct gfs2_holder *gh = gl->gl_req_gh;
742 int prev_state = gl->gl_state;
745 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
746 gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
747 gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC));
749 state_change(gl, ret & LM_OUT_ST_MASK);
751 if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) {
753 glops->go_inval(gl, DIO_METADATA);
754 } else if (gl->gl_state == LM_ST_DEFERRED) {
755 /* We might not want to do this here.
756 Look at moving to the inode glops. */
758 glops->go_inval(gl, 0);
761 /* Deal with each possible exit condition */
764 gl->gl_stamp = jiffies;
765 if (ret & LM_OUT_CANCELED) {
768 spin_lock(&gl->gl_spin);
769 if (gl->gl_state != gl->gl_demote_state) {
770 gl->gl_req_bh = NULL;
771 spin_unlock(&gl->gl_spin);
772 gfs2_glock_drop_th(gl);
776 gfs2_demote_wake(gl);
777 spin_unlock(&gl->gl_spin);
780 spin_lock(&gl->gl_spin);
781 list_del_init(&gh->gh_list);
783 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
785 gh->gh_error = GLR_CANCELED;
786 if (ret & LM_OUT_CANCELED)
788 if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
789 list_add_tail(&gh->gh_list, &gl->gl_holders);
791 set_bit(HIF_HOLDER, &gh->gh_iflags);
792 set_bit(HIF_FIRST, &gh->gh_iflags);
796 gh->gh_error = GLR_TRYFAILED;
797 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
799 gh->gh_error = -EINVAL;
800 if (gfs2_assert_withdraw(sdp, 0) == -1)
801 fs_err(sdp, "ret = 0x%.8X\n", ret);
803 spin_unlock(&gl->gl_spin);
806 if (glops->go_xmote_bh)
807 glops->go_xmote_bh(gl);
810 spin_lock(&gl->gl_spin);
811 gl->gl_req_gh = NULL;
812 gl->gl_req_bh = NULL;
813 clear_bit(GLF_LOCK, &gl->gl_flags);
815 spin_unlock(&gl->gl_spin);
821 gfs2_holder_wake(gh);
825 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
826 * @gl: The glock in question
827 * @state: the requested state
828 * @flags: modifier flags to the lock call
832 static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh)
834 struct gfs2_sbd *sdp = gl->gl_sbd;
835 int flags = gh ? gh->gh_flags : 0;
836 unsigned state = gh ? gh->gh_state : gl->gl_demote_state;
837 const struct gfs2_glock_operations *glops = gl->gl_ops;
838 int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB |
839 LM_FLAG_NOEXP | LM_FLAG_ANY |
841 unsigned int lck_ret;
843 if (glops->go_xmote_th)
844 glops->go_xmote_th(gl);
846 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
847 gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
848 gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED);
849 gfs2_assert_warn(sdp, state != gl->gl_state);
852 gl->gl_req_bh = xmote_bh;
854 lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags);
856 if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR)))
859 if (lck_ret & LM_OUT_ASYNC)
860 gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC);
862 xmote_bh(gl, lck_ret);
866 * drop_bh - Called after a lock module unlock completes
868 * @ret: the return status
870 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
871 * Doesn't drop the reference on the glock the top half took out
875 static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
877 struct gfs2_sbd *sdp = gl->gl_sbd;
878 const struct gfs2_glock_operations *glops = gl->gl_ops;
879 struct gfs2_holder *gh = gl->gl_req_gh;
881 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
882 gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
883 gfs2_assert_warn(sdp, !ret);
885 state_change(gl, LM_ST_UNLOCKED);
886 gfs2_demote_wake(gl);
889 glops->go_inval(gl, DIO_METADATA);
892 spin_lock(&gl->gl_spin);
893 list_del_init(&gh->gh_list);
895 spin_unlock(&gl->gl_spin);
898 spin_lock(&gl->gl_spin);
899 gl->gl_req_gh = NULL;
900 gl->gl_req_bh = NULL;
901 clear_bit(GLF_LOCK, &gl->gl_flags);
903 spin_unlock(&gl->gl_spin);
908 gfs2_holder_wake(gh);
912 * gfs2_glock_drop_th - call into the lock module to unlock a lock
917 static void gfs2_glock_drop_th(struct gfs2_glock *gl)
919 struct gfs2_sbd *sdp = gl->gl_sbd;
920 const struct gfs2_glock_operations *glops = gl->gl_ops;
923 if (glops->go_drop_th)
924 glops->go_drop_th(gl);
926 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
927 gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
928 gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED);
931 gl->gl_req_bh = drop_bh;
933 ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state);
935 if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR)))
941 gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC);
945 * do_cancels - cancel requests for locks stuck waiting on an expire flag
946 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
948 * Don't cancel GL_NOCANCEL requests.
951 static void do_cancels(struct gfs2_holder *gh)
953 struct gfs2_glock *gl = gh->gh_gl;
955 spin_lock(&gl->gl_spin);
957 while (gl->gl_req_gh != gh &&
958 !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
959 !list_empty(&gh->gh_list)) {
960 if (gl->gl_req_bh && !(gl->gl_req_gh &&
961 (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) {
962 spin_unlock(&gl->gl_spin);
963 gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock);
965 spin_lock(&gl->gl_spin);
967 spin_unlock(&gl->gl_spin);
969 spin_lock(&gl->gl_spin);
973 spin_unlock(&gl->gl_spin);
977 * glock_wait_internal - wait on a glock acquisition
978 * @gh: the glock holder
980 * Returns: 0 on success
983 static int glock_wait_internal(struct gfs2_holder *gh)
985 struct gfs2_glock *gl = gh->gh_gl;
986 struct gfs2_sbd *sdp = gl->gl_sbd;
987 const struct gfs2_glock_operations *glops = gl->gl_ops;
989 if (test_bit(HIF_ABORTED, &gh->gh_iflags))
992 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
993 spin_lock(&gl->gl_spin);
994 if (gl->gl_req_gh != gh &&
995 !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
996 !list_empty(&gh->gh_list)) {
997 list_del_init(&gh->gh_list);
998 gh->gh_error = GLR_TRYFAILED;
1000 spin_unlock(&gl->gl_spin);
1001 return gh->gh_error;
1003 spin_unlock(&gl->gl_spin);
1006 if (gh->gh_flags & LM_FLAG_PRIORITY)
1011 return gh->gh_error;
1013 gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags));
1014 gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state,
1017 if (test_bit(HIF_FIRST, &gh->gh_iflags)) {
1018 gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
1020 if (glops->go_lock) {
1021 gh->gh_error = glops->go_lock(gh);
1023 spin_lock(&gl->gl_spin);
1024 list_del_init(&gh->gh_list);
1025 spin_unlock(&gl->gl_spin);
1029 spin_lock(&gl->gl_spin);
1030 gl->gl_req_gh = NULL;
1031 gl->gl_req_bh = NULL;
1032 clear_bit(GLF_LOCK, &gl->gl_flags);
1034 spin_unlock(&gl->gl_spin);
1037 return gh->gh_error;
1040 static inline struct gfs2_holder *
1041 find_holder_by_owner(struct list_head *head, pid_t pid)
1043 struct gfs2_holder *gh;
1045 list_for_each_entry(gh, head, gh_list) {
1046 if (gh->gh_owner_pid == pid)
1053 static void print_dbg(struct glock_iter *gi, const char *fmt, ...)
1057 va_start(args, fmt);
1059 vsprintf(gi->string, fmt, args);
1060 seq_printf(gi->seq, gi->string);
1068 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1069 * @gh: the holder structure to add
1073 static void add_to_queue(struct gfs2_holder *gh)
1075 struct gfs2_glock *gl = gh->gh_gl;
1076 struct gfs2_holder *existing;
1078 BUG_ON(!gh->gh_owner_pid);
1079 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
1082 existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner_pid);
1084 print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
1085 printk(KERN_INFO "pid : %d\n", existing->gh_owner_pid);
1086 printk(KERN_INFO "lock type : %d lock state : %d\n",
1087 existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state);
1088 print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
1089 printk(KERN_INFO "pid : %d\n", gh->gh_owner_pid);
1090 printk(KERN_INFO "lock type : %d lock state : %d\n",
1091 gl->gl_name.ln_type, gl->gl_state);
1095 existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner_pid);
1097 print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
1098 print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
1102 if (gh->gh_flags & LM_FLAG_PRIORITY)
1103 list_add(&gh->gh_list, &gl->gl_waiters3);
1105 list_add_tail(&gh->gh_list, &gl->gl_waiters3);
1109 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1110 * @gh: the holder structure
1112 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1114 * Returns: 0, GLR_TRYFAILED, or errno on failure
1117 int gfs2_glock_nq(struct gfs2_holder *gh)
1119 struct gfs2_glock *gl = gh->gh_gl;
1120 struct gfs2_sbd *sdp = gl->gl_sbd;
1124 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
1125 set_bit(HIF_ABORTED, &gh->gh_iflags);
1129 set_bit(HIF_PROMOTE, &gh->gh_iflags);
1131 spin_lock(&gl->gl_spin);
1134 spin_unlock(&gl->gl_spin);
1136 if (!(gh->gh_flags & GL_ASYNC)) {
1137 error = glock_wait_internal(gh);
1138 if (error == GLR_CANCELED) {
1148 * gfs2_glock_poll - poll to see if an async request has been completed
1151 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1154 int gfs2_glock_poll(struct gfs2_holder *gh)
1156 struct gfs2_glock *gl = gh->gh_gl;
1159 spin_lock(&gl->gl_spin);
1161 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1163 else if (list_empty(&gh->gh_list)) {
1164 if (gh->gh_error == GLR_CANCELED) {
1165 spin_unlock(&gl->gl_spin);
1167 if (gfs2_glock_nq(gh))
1174 spin_unlock(&gl->gl_spin);
1180 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1181 * @gh: the holder structure
1183 * Returns: 0, GLR_TRYFAILED, or errno on failure
1186 int gfs2_glock_wait(struct gfs2_holder *gh)
1190 error = glock_wait_internal(gh);
1191 if (error == GLR_CANCELED) {
1193 gh->gh_flags &= ~GL_ASYNC;
1194 error = gfs2_glock_nq(gh);
1201 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1202 * @gh: the glock holder
1206 void gfs2_glock_dq(struct gfs2_holder *gh)
1208 struct gfs2_glock *gl = gh->gh_gl;
1209 const struct gfs2_glock_operations *glops = gl->gl_ops;
1211 if (gh->gh_flags & GL_NOCACHE)
1212 handle_callback(gl, LM_ST_UNLOCKED, 0);
1214 gfs2_glmutex_lock(gl);
1216 spin_lock(&gl->gl_spin);
1217 list_del_init(&gh->gh_list);
1219 if (list_empty(&gl->gl_holders)) {
1220 spin_unlock(&gl->gl_spin);
1222 if (glops->go_unlock)
1223 glops->go_unlock(gh);
1225 spin_lock(&gl->gl_spin);
1226 gl->gl_stamp = jiffies;
1229 clear_bit(GLF_LOCK, &gl->gl_flags);
1231 spin_unlock(&gl->gl_spin);
1234 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1236 struct gfs2_glock *gl = gh->gh_gl;
1242 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1243 * @gh: the holder structure
1247 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1250 gfs2_holder_uninit(gh);
1254 * gfs2_glock_nq_num - acquire a glock based on lock number
1255 * @sdp: the filesystem
1256 * @number: the lock number
1257 * @glops: the glock operations for the type of glock
1258 * @state: the state to acquire the glock in
1259 * @flags: modifier flags for the aquisition
1260 * @gh: the struct gfs2_holder
1265 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1266 const struct gfs2_glock_operations *glops,
1267 unsigned int state, int flags, struct gfs2_holder *gh)
1269 struct gfs2_glock *gl;
1272 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1274 error = gfs2_glock_nq_init(gl, state, flags, gh);
1282 * glock_compare - Compare two struct gfs2_glock structures for sorting
1283 * @arg_a: the first structure
1284 * @arg_b: the second structure
1288 static int glock_compare(const void *arg_a, const void *arg_b)
1290 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1291 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1292 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1293 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1295 if (a->ln_number > b->ln_number)
1297 if (a->ln_number < b->ln_number)
1299 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1304 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1305 * @num_gh: the number of structures
1306 * @ghs: an array of struct gfs2_holder structures
1308 * Returns: 0 on success (all glocks acquired),
1309 * errno on failure (no glocks acquired)
1312 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1313 struct gfs2_holder **p)
1318 for (x = 0; x < num_gh; x++)
1321 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1323 for (x = 0; x < num_gh; x++) {
1324 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1326 error = gfs2_glock_nq(p[x]);
1329 gfs2_glock_dq(p[x]);
1338 * gfs2_glock_nq_m - acquire multiple glocks
1339 * @num_gh: the number of structures
1340 * @ghs: an array of struct gfs2_holder structures
1343 * Returns: 0 on success (all glocks acquired),
1344 * errno on failure (no glocks acquired)
1347 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1349 struct gfs2_holder *tmp[4];
1350 struct gfs2_holder **pph = tmp;
1357 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1358 return gfs2_glock_nq(ghs);
1362 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1367 error = nq_m_sync(num_gh, ghs, pph);
1376 * gfs2_glock_dq_m - release multiple glocks
1377 * @num_gh: the number of structures
1378 * @ghs: an array of struct gfs2_holder structures
1382 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1386 for (x = 0; x < num_gh; x++)
1387 gfs2_glock_dq(&ghs[x]);
1391 * gfs2_glock_dq_uninit_m - release multiple glocks
1392 * @num_gh: the number of structures
1393 * @ghs: an array of struct gfs2_holder structures
1397 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1401 for (x = 0; x < num_gh; x++)
1402 gfs2_glock_dq_uninit(&ghs[x]);
1406 * gfs2_lvb_hold - attach a LVB from a glock
1407 * @gl: The glock in question
1411 int gfs2_lvb_hold(struct gfs2_glock *gl)
1415 gfs2_glmutex_lock(gl);
1417 if (!atomic_read(&gl->gl_lvb_count)) {
1418 error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
1420 gfs2_glmutex_unlock(gl);
1423 gfs2_glock_hold(gl);
1425 atomic_inc(&gl->gl_lvb_count);
1427 gfs2_glmutex_unlock(gl);
1433 * gfs2_lvb_unhold - detach a LVB from a glock
1434 * @gl: The glock in question
1438 void gfs2_lvb_unhold(struct gfs2_glock *gl)
1440 gfs2_glock_hold(gl);
1441 gfs2_glmutex_lock(gl);
1443 gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
1444 if (atomic_dec_and_test(&gl->gl_lvb_count)) {
1445 gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb);
1450 gfs2_glmutex_unlock(gl);
1454 static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
1457 struct gfs2_glock *gl;
1459 gl = gfs2_glock_find(sdp, name);
1463 handle_callback(gl, state, 1);
1465 spin_lock(&gl->gl_spin);
1467 spin_unlock(&gl->gl_spin);
1473 * gfs2_glock_cb - Callback used by locking module
1474 * @sdp: Pointer to the superblock
1475 * @type: Type of callback
1476 * @data: Type dependent data pointer
1478 * Called by the locking module when it wants to tell us something.
1479 * Either we need to drop a lock, one of our ASYNC requests completed, or
1480 * a journal from another client needs to be recovered.
1483 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
1485 struct gfs2_sbd *sdp = cb_data;
1489 blocking_cb(sdp, data, LM_ST_UNLOCKED);
1493 blocking_cb(sdp, data, LM_ST_DEFERRED);
1497 blocking_cb(sdp, data, LM_ST_SHARED);
1501 struct lm_async_cb *async = data;
1502 struct gfs2_glock *gl;
1504 down_read(&gfs2_umount_flush_sem);
1505 gl = gfs2_glock_find(sdp, &async->lc_name);
1506 if (gfs2_assert_warn(sdp, gl))
1508 if (!gfs2_assert_warn(sdp, gl->gl_req_bh))
1509 gl->gl_req_bh(gl, async->lc_ret);
1511 up_read(&gfs2_umount_flush_sem);
1515 case LM_CB_NEED_RECOVERY:
1516 gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data);
1517 if (sdp->sd_recoverd_process)
1518 wake_up_process(sdp->sd_recoverd_process);
1521 case LM_CB_DROPLOCKS:
1522 gfs2_gl_hash_clear(sdp, NO_WAIT);
1523 gfs2_quota_scan(sdp);
1527 gfs2_assert_warn(sdp, 0);
1533 * demote_ok - Check to see if it's ok to unlock a glock
1536 * Returns: 1 if it's ok
1539 static int demote_ok(struct gfs2_glock *gl)
1541 const struct gfs2_glock_operations *glops = gl->gl_ops;
1544 if (test_bit(GLF_STICKY, &gl->gl_flags))
1546 else if (glops->go_demote_ok)
1547 demote = glops->go_demote_ok(gl);
1553 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1558 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
1560 struct gfs2_sbd *sdp = gl->gl_sbd;
1562 spin_lock(&sdp->sd_reclaim_lock);
1563 if (list_empty(&gl->gl_reclaim)) {
1564 gfs2_glock_hold(gl);
1565 list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
1566 atomic_inc(&sdp->sd_reclaim_count);
1568 spin_unlock(&sdp->sd_reclaim_lock);
1570 wake_up(&sdp->sd_reclaim_wq);
1574 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1575 * @sdp: the filesystem
1577 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1578 * different glock and we notice that there are a lot of glocks in the
1583 void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
1585 struct gfs2_glock *gl;
1587 spin_lock(&sdp->sd_reclaim_lock);
1588 if (list_empty(&sdp->sd_reclaim_list)) {
1589 spin_unlock(&sdp->sd_reclaim_lock);
1592 gl = list_entry(sdp->sd_reclaim_list.next,
1593 struct gfs2_glock, gl_reclaim);
1594 list_del_init(&gl->gl_reclaim);
1595 spin_unlock(&sdp->sd_reclaim_lock);
1597 atomic_dec(&sdp->sd_reclaim_count);
1598 atomic_inc(&sdp->sd_reclaimed);
1600 if (gfs2_glmutex_trylock(gl)) {
1601 if (list_empty(&gl->gl_holders) &&
1602 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1603 handle_callback(gl, LM_ST_UNLOCKED, 0);
1604 gfs2_glmutex_unlock(gl);
1611 * examine_bucket - Call a function for glock in a hash bucket
1612 * @examiner: the function
1613 * @sdp: the filesystem
1614 * @bucket: the bucket
1616 * Returns: 1 if the bucket has entries
1619 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
1622 struct gfs2_glock *gl, *prev = NULL;
1623 int has_entries = 0;
1624 struct hlist_head *head = &gl_hash_table[hash].hb_list;
1626 read_lock(gl_lock_addr(hash));
1627 /* Can't use hlist_for_each_entry - don't want prefetch here */
1628 if (hlist_empty(head))
1630 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1632 if (gl->gl_sbd == sdp) {
1633 gfs2_glock_hold(gl);
1634 read_unlock(gl_lock_addr(hash));
1636 gfs2_glock_put(prev);
1640 read_lock(gl_lock_addr(hash));
1642 if (gl->gl_list.next == NULL)
1644 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
1647 read_unlock(gl_lock_addr(hash));
1649 gfs2_glock_put(prev);
1654 * scan_glock - look at a glock and see if we can reclaim it
1655 * @gl: the glock to look at
1659 static void scan_glock(struct gfs2_glock *gl)
1661 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
1664 if (gfs2_glmutex_trylock(gl)) {
1665 if (list_empty(&gl->gl_holders) &&
1666 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1668 gfs2_glmutex_unlock(gl);
1673 gfs2_glmutex_unlock(gl);
1674 gfs2_glock_schedule_for_reclaim(gl);
1678 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1679 * @sdp: the filesystem
1683 void gfs2_scand_internal(struct gfs2_sbd *sdp)
1687 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1688 examine_bucket(scan_glock, sdp, x);
1692 * clear_glock - look at a glock and see if we can free it from glock cache
1693 * @gl: the glock to look at
1697 static void clear_glock(struct gfs2_glock *gl)
1699 struct gfs2_sbd *sdp = gl->gl_sbd;
1702 spin_lock(&sdp->sd_reclaim_lock);
1703 if (!list_empty(&gl->gl_reclaim)) {
1704 list_del_init(&gl->gl_reclaim);
1705 atomic_dec(&sdp->sd_reclaim_count);
1706 spin_unlock(&sdp->sd_reclaim_lock);
1707 released = gfs2_glock_put(gl);
1708 gfs2_assert(sdp, !released);
1710 spin_unlock(&sdp->sd_reclaim_lock);
1713 if (gfs2_glmutex_trylock(gl)) {
1714 if (list_empty(&gl->gl_holders) &&
1715 gl->gl_state != LM_ST_UNLOCKED)
1716 handle_callback(gl, LM_ST_UNLOCKED, 0);
1717 gfs2_glmutex_unlock(gl);
1722 * gfs2_gl_hash_clear - Empty out the glock hash table
1723 * @sdp: the filesystem
1724 * @wait: wait until it's all gone
1726 * Called when unmounting the filesystem, or when inter-node lock manager
1727 * requests DROPLOCKS because it is running out of capacity.
1730 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
1740 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1741 if (examine_bucket(clear_glock, sdp, x))
1748 if (time_after_eq(jiffies,
1749 t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
1750 fs_warn(sdp, "Unmount seems to be stalled. "
1751 "Dumping lock state...\n");
1752 gfs2_dump_lockstate(sdp);
1756 down_write(&gfs2_umount_flush_sem);
1757 invalidate_inodes(sdp->sd_vfs);
1758 up_write(&gfs2_umount_flush_sem);
1764 * Diagnostic routines to help debug distributed deadlock
1767 static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt,
1768 unsigned long address)
1770 char buffer[KSYM_SYMBOL_LEN];
1772 sprint_symbol(buffer, address);
1773 print_dbg(gi, fmt, buffer);
1777 * dump_holder - print information about a glock holder
1778 * @str: a string naming the type of holder
1779 * @gh: the glock holder
1781 * Returns: 0 on success, -ENOBUFS when we run out of space
1784 static int dump_holder(struct glock_iter *gi, char *str,
1785 struct gfs2_holder *gh)
1788 struct task_struct *gh_owner;
1790 print_dbg(gi, " %s\n", str);
1791 if (gh->gh_owner_pid) {
1792 print_dbg(gi, " owner = %ld ", (long)gh->gh_owner_pid);
1793 gh_owner = find_task_by_pid(gh->gh_owner_pid);
1795 print_dbg(gi, "(%s)\n", gh_owner->comm);
1797 print_dbg(gi, "(ended)\n");
1799 print_dbg(gi, " owner = -1\n");
1800 print_dbg(gi, " gh_state = %u\n", gh->gh_state);
1801 print_dbg(gi, " gh_flags =");
1802 for (x = 0; x < 32; x++)
1803 if (gh->gh_flags & (1 << x))
1804 print_dbg(gi, " %u", x);
1805 print_dbg(gi, " \n");
1806 print_dbg(gi, " error = %d\n", gh->gh_error);
1807 print_dbg(gi, " gh_iflags =");
1808 for (x = 0; x < 32; x++)
1809 if (test_bit(x, &gh->gh_iflags))
1810 print_dbg(gi, " %u", x);
1811 print_dbg(gi, " \n");
1812 gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip);
1818 * dump_inode - print information about an inode
1821 * Returns: 0 on success, -ENOBUFS when we run out of space
1824 static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip)
1828 print_dbg(gi, " Inode:\n");
1829 print_dbg(gi, " num = %llu/%llu\n",
1830 (unsigned long long)ip->i_no_formal_ino,
1831 (unsigned long long)ip->i_no_addr);
1832 print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode));
1833 print_dbg(gi, " i_flags =");
1834 for (x = 0; x < 32; x++)
1835 if (test_bit(x, &ip->i_flags))
1836 print_dbg(gi, " %u", x);
1837 print_dbg(gi, " \n");
1842 * dump_glock - print information about a glock
1844 * @count: where we are in the buffer
1846 * Returns: 0 on success, -ENOBUFS when we run out of space
1849 static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl)
1851 struct gfs2_holder *gh;
1853 int error = -ENOBUFS;
1854 struct task_struct *gl_owner;
1856 spin_lock(&gl->gl_spin);
1858 print_dbg(gi, "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type,
1859 (unsigned long long)gl->gl_name.ln_number);
1860 print_dbg(gi, " gl_flags =");
1861 for (x = 0; x < 32; x++) {
1862 if (test_bit(x, &gl->gl_flags))
1863 print_dbg(gi, " %u", x);
1865 if (!test_bit(GLF_LOCK, &gl->gl_flags))
1866 print_dbg(gi, " (unlocked)");
1867 print_dbg(gi, " \n");
1868 print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref));
1869 print_dbg(gi, " gl_state = %u\n", gl->gl_state);
1870 if (gl->gl_owner_pid) {
1871 gl_owner = find_task_by_pid(gl->gl_owner_pid);
1873 print_dbg(gi, " gl_owner = pid %d (%s)\n",
1874 gl->gl_owner_pid, gl_owner->comm);
1876 print_dbg(gi, " gl_owner = %d (ended)\n",
1879 print_dbg(gi, " gl_owner = -1\n");
1880 print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip);
1881 print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no");
1882 print_dbg(gi, " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no");
1883 print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count));
1884 print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no");
1885 print_dbg(gi, " le = %s\n",
1886 (list_empty(&gl->gl_le.le_list)) ? "no" : "yes");
1887 print_dbg(gi, " reclaim = %s\n",
1888 (list_empty(&gl->gl_reclaim)) ? "no" : "yes");
1890 print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace,
1891 gl->gl_aspace->i_mapping->nrpages);
1893 print_dbg(gi, " aspace = no\n");
1894 print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count));
1895 if (gl->gl_req_gh) {
1896 error = dump_holder(gi, "Request", gl->gl_req_gh);
1900 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1901 error = dump_holder(gi, "Holder", gh);
1905 list_for_each_entry(gh, &gl->gl_waiters1, gh_list) {
1906 error = dump_holder(gi, "Waiter1", gh);
1910 list_for_each_entry(gh, &gl->gl_waiters3, gh_list) {
1911 error = dump_holder(gi, "Waiter3", gh);
1915 if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
1916 print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n",
1917 gl->gl_demote_state, (unsigned long long)
1918 (jiffies - gl->gl_demote_time)*(1000000/HZ));
1920 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) {
1921 if (!test_bit(GLF_LOCK, &gl->gl_flags) &&
1922 list_empty(&gl->gl_holders)) {
1923 error = dump_inode(gi, gl->gl_object);
1928 print_dbg(gi, " Inode: busy\n");
1935 spin_unlock(&gl->gl_spin);
1940 * gfs2_dump_lockstate - print out the current lockstate
1941 * @sdp: the filesystem
1942 * @ub: the buffer to copy the information into
1944 * If @ub is NULL, dump the lockstate to the console.
1948 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
1950 struct gfs2_glock *gl;
1951 struct hlist_node *h;
1955 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
1957 read_lock(gl_lock_addr(x));
1959 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
1960 if (gl->gl_sbd != sdp)
1963 error = dump_glock(NULL, gl);
1968 read_unlock(gl_lock_addr(x));
1978 int __init gfs2_glock_init(void)
1981 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1982 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
1984 #ifdef GL_HASH_LOCK_SZ
1985 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1986 rwlock_init(&gl_hash_locks[i]);
1992 static int gfs2_glock_iter_next(struct glock_iter *gi)
1994 read_lock(gl_lock_addr(gi->hash));
1996 if (!gi->hb_list) { /* If we don't have a hash bucket yet */
1997 gi->hb_list = &gl_hash_table[gi->hash].hb_list;
1998 if (hlist_empty(gi->hb_list)) {
1999 read_unlock(gl_lock_addr(gi->hash));
2001 read_lock(gl_lock_addr(gi->hash));
2003 if (gi->hash >= GFS2_GL_HASH_SIZE) {
2004 read_unlock(gl_lock_addr(gi->hash));
2010 if (!hlist_empty(gi->hb_list)) {
2011 gi->gl = list_entry(gi->hb_list->first,
2016 if (gi->gl->gl_list.next == NULL) {
2017 read_unlock(gl_lock_addr(gi->hash));
2019 read_lock(gl_lock_addr(gi->hash));
2023 gi->gl = list_entry(gi->gl->gl_list.next,
2024 struct gfs2_glock, gl_list);
2029 read_unlock(gl_lock_addr(gi->hash));
2033 static void gfs2_glock_iter_free(struct glock_iter *gi)
2038 static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp)
2040 struct glock_iter *gi;
2042 gi = kmalloc(sizeof (*gi), GFP_KERNEL);
2051 memset(gi->string, 0, sizeof(gi->string));
2053 if (gfs2_glock_iter_next(gi)) {
2054 gfs2_glock_iter_free(gi);
2061 static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos)
2063 struct glock_iter *gi;
2066 gi = gfs2_glock_iter_init(file->private);
2071 if (gfs2_glock_iter_next(gi)) {
2072 gfs2_glock_iter_free(gi);
2080 static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr,
2083 struct glock_iter *gi = iter_ptr;
2087 if (gfs2_glock_iter_next(gi)) {
2088 gfs2_glock_iter_free(gi);
2095 static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr)
2097 /* nothing for now */
2100 static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
2102 struct glock_iter *gi = iter_ptr;
2105 dump_glock(gi, gi->gl);
2110 static struct seq_operations gfs2_glock_seq_ops = {
2111 .start = gfs2_glock_seq_start,
2112 .next = gfs2_glock_seq_next,
2113 .stop = gfs2_glock_seq_stop,
2114 .show = gfs2_glock_seq_show,
2117 static int gfs2_debugfs_open(struct inode *inode, struct file *file)
2119 struct seq_file *seq;
2122 ret = seq_open(file, &gfs2_glock_seq_ops);
2126 seq = file->private_data;
2127 seq->private = inode->i_private;
2132 static const struct file_operations gfs2_debug_fops = {
2133 .owner = THIS_MODULE,
2134 .open = gfs2_debugfs_open,
2136 .llseek = seq_lseek,
2137 .release = seq_release
2140 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
2142 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
2143 if (!sdp->debugfs_dir)
2145 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
2147 sdp->debugfs_dir, sdp,
2149 if (!sdp->debugfs_dentry_glocks)
2155 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2157 if (sdp && sdp->debugfs_dir) {
2158 if (sdp->debugfs_dentry_glocks) {
2159 debugfs_remove(sdp->debugfs_dentry_glocks);
2160 sdp->debugfs_dentry_glocks = NULL;
2162 debugfs_remove(sdp->debugfs_dir);
2163 sdp->debugfs_dir = NULL;
2167 int gfs2_register_debugfs(void)
2169 gfs2_root = debugfs_create_dir("gfs2", NULL);
2170 return gfs2_root ? 0 : -ENOMEM;
2173 void gfs2_unregister_debugfs(void)
2175 debugfs_remove(gfs2_root);