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>
39 struct gfs2_gl_hash_bucket
{
40 struct hlist_head hb_list
;
43 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
45 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
46 static int dump_glock(struct gfs2_glock
*gl
);
47 static int dump_inode(struct gfs2_inode
*ip
);
48 static void gfs2_glock_xmote_th(struct gfs2_holder
*gh
);
49 static void gfs2_glock_drop_th(struct gfs2_glock
*gl
);
50 static DECLARE_RWSEM(gfs2_umount_flush_sem
);
52 #define GFS2_GL_HASH_SHIFT 15
53 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
54 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
56 static struct gfs2_gl_hash_bucket gl_hash_table
[GFS2_GL_HASH_SIZE
];
59 * Despite what you might think, the numbers below are not arbitrary :-)
60 * They are taken from the ipv4 routing hash code, which is well tested
61 * and thus should be nearly optimal. Later on we might tweek the numbers
62 * but for now this should be fine.
64 * The reason for putting the locks in a separate array from the list heads
65 * is that we can have fewer locks than list heads and save memory. We use
66 * the same hash function for both, but with a different hash mask.
68 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
69 defined(CONFIG_PROVE_LOCKING)
72 # define GL_HASH_LOCK_SZ 256
75 # define GL_HASH_LOCK_SZ 4096
77 # define GL_HASH_LOCK_SZ 2048
79 # define GL_HASH_LOCK_SZ 1024
81 # define GL_HASH_LOCK_SZ 512
83 # define GL_HASH_LOCK_SZ 256
87 /* We never want more locks than chains */
88 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
89 # undef GL_HASH_LOCK_SZ
90 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
93 static rwlock_t gl_hash_locks
[GL_HASH_LOCK_SZ
];
95 static inline rwlock_t
*gl_lock_addr(unsigned int x
)
97 return &gl_hash_locks
[x
& (GL_HASH_LOCK_SZ
-1)];
99 #else /* not SMP, so no spinlocks required */
100 static inline rwlock_t
*gl_lock_addr(unsigned int x
)
107 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
108 * @actual: the current state of the lock
109 * @requested: the lock state that was requested by the caller
110 * @flags: the modifier flags passed in by the caller
112 * Returns: 1 if the locks are compatible, 0 otherwise
115 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
118 if (actual
== requested
)
121 if (flags
& GL_EXACT
)
124 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
127 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
134 * gl_hash() - Turn glock number into hash bucket number
135 * @lock: The glock number
137 * Returns: The number of the corresponding hash bucket
140 static unsigned int gl_hash(const struct gfs2_sbd
*sdp
,
141 const struct lm_lockname
*name
)
145 h
= jhash(&name
->ln_number
, sizeof(u64
), 0);
146 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
147 h
= jhash(&sdp
, sizeof(struct gfs2_sbd
*), h
);
148 h
&= GFS2_GL_HASH_MASK
;
154 * glock_free() - Perform a few checks and then release struct gfs2_glock
155 * @gl: The glock to release
157 * Also calls lock module to release its internal structure for this glock.
161 static void glock_free(struct gfs2_glock
*gl
)
163 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
164 struct inode
*aspace
= gl
->gl_aspace
;
166 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
169 gfs2_aspace_put(aspace
);
171 kmem_cache_free(gfs2_glock_cachep
, gl
);
175 * gfs2_glock_hold() - increment reference count on glock
176 * @gl: The glock to hold
180 void gfs2_glock_hold(struct gfs2_glock
*gl
)
182 atomic_inc(&gl
->gl_ref
);
186 * gfs2_glock_put() - Decrement reference count on glock
187 * @gl: The glock to put
191 int gfs2_glock_put(struct gfs2_glock
*gl
)
194 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
196 write_lock(gl_lock_addr(gl
->gl_hash
));
197 if (atomic_dec_and_test(&gl
->gl_ref
)) {
198 hlist_del(&gl
->gl_list
);
199 write_unlock(gl_lock_addr(gl
->gl_hash
));
200 BUG_ON(spin_is_locked(&gl
->gl_spin
));
201 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
202 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
203 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
204 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
205 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
206 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
211 write_unlock(gl_lock_addr(gl
->gl_hash
));
217 * search_bucket() - Find struct gfs2_glock by lock number
218 * @bucket: the bucket to search
219 * @name: The lock name
221 * Returns: NULL, or the struct gfs2_glock with the requested number
224 static struct gfs2_glock
*search_bucket(unsigned int hash
,
225 const struct gfs2_sbd
*sdp
,
226 const struct lm_lockname
*name
)
228 struct gfs2_glock
*gl
;
229 struct hlist_node
*h
;
231 hlist_for_each_entry(gl
, h
, &gl_hash_table
[hash
].hb_list
, gl_list
) {
232 if (!lm_name_equal(&gl
->gl_name
, name
))
234 if (gl
->gl_sbd
!= sdp
)
237 atomic_inc(&gl
->gl_ref
);
246 * gfs2_glock_find() - Find glock by lock number
247 * @sdp: The GFS2 superblock
248 * @name: The lock name
250 * Returns: NULL, or the struct gfs2_glock with the requested number
253 static struct gfs2_glock
*gfs2_glock_find(const struct gfs2_sbd
*sdp
,
254 const struct lm_lockname
*name
)
256 unsigned int hash
= gl_hash(sdp
, name
);
257 struct gfs2_glock
*gl
;
259 read_lock(gl_lock_addr(hash
));
260 gl
= search_bucket(hash
, sdp
, name
);
261 read_unlock(gl_lock_addr(hash
));
267 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
268 * @sdp: The GFS2 superblock
269 * @number: the lock number
270 * @glops: The glock_operations to use
271 * @create: If 0, don't create the glock if it doesn't exist
272 * @glp: the glock is returned here
274 * This does not lock a glock, just finds/creates structures for one.
279 int gfs2_glock_get(struct gfs2_sbd
*sdp
, u64 number
,
280 const struct gfs2_glock_operations
*glops
, int create
,
281 struct gfs2_glock
**glp
)
283 struct lm_lockname name
= { .ln_number
= number
, .ln_type
= glops
->go_type
};
284 struct gfs2_glock
*gl
, *tmp
;
285 unsigned int hash
= gl_hash(sdp
, &name
);
288 read_lock(gl_lock_addr(hash
));
289 gl
= search_bucket(hash
, sdp
, &name
);
290 read_unlock(gl_lock_addr(hash
));
297 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
303 atomic_set(&gl
->gl_ref
, 1);
304 gl
->gl_state
= LM_ST_UNLOCKED
;
309 gl
->gl_req_gh
= NULL
;
310 gl
->gl_req_bh
= NULL
;
312 gl
->gl_stamp
= jiffies
;
313 gl
->gl_object
= NULL
;
315 gl
->gl_aspace
= NULL
;
316 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
318 /* If this glock protects actual on-disk data or metadata blocks,
319 create a VFS inode to manage the pages/buffers holding them. */
320 if (glops
== &gfs2_inode_glops
|| glops
== &gfs2_rgrp_glops
) {
321 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
322 if (!gl
->gl_aspace
) {
328 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
332 write_lock(gl_lock_addr(hash
));
333 tmp
= search_bucket(hash
, sdp
, &name
);
335 write_unlock(gl_lock_addr(hash
));
339 hlist_add_head(&gl
->gl_list
, &gl_hash_table
[hash
].hb_list
);
340 write_unlock(gl_lock_addr(hash
));
349 gfs2_aspace_put(gl
->gl_aspace
);
351 kmem_cache_free(gfs2_glock_cachep
, gl
);
356 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
358 * @state: the state we're requesting
359 * @flags: the modifier flags
360 * @gh: the holder structure
364 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
365 struct gfs2_holder
*gh
)
367 INIT_LIST_HEAD(&gh
->gh_list
);
369 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
370 gh
->gh_owner
= current
;
371 gh
->gh_state
= state
;
372 gh
->gh_flags
= flags
;
379 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
380 * @state: the state we're requesting
381 * @flags: the modifier flags
382 * @gh: the holder structure
384 * Don't mess with the glock.
388 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
390 gh
->gh_state
= state
;
391 gh
->gh_flags
= flags
;
392 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
393 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
397 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
398 * @gh: the holder structure
402 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
404 gfs2_glock_put(gh
->gh_gl
);
410 * gfs2_holder_get - get a struct gfs2_holder structure
412 * @state: the state we're requesting
413 * @flags: the modifier flags
416 * Figure out how big an impact this function has. Either:
417 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
418 * 2) Leave it like it is
420 * Returns: the holder structure, NULL on ENOMEM
423 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
425 int flags
, gfp_t gfp_flags
)
427 struct gfs2_holder
*gh
;
429 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
433 gfs2_holder_init(gl
, state
, flags
, gh
);
434 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
435 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
440 * gfs2_holder_put - get rid of a struct gfs2_holder structure
441 * @gh: the holder structure
445 static void gfs2_holder_put(struct gfs2_holder
*gh
)
447 gfs2_holder_uninit(gh
);
451 static void gfs2_holder_dispose_or_wake(struct gfs2_holder
*gh
)
453 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
)) {
457 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
459 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
462 static int holder_wait(void *word
)
468 static void wait_on_holder(struct gfs2_holder
*gh
)
471 wait_on_bit(&gh
->gh_iflags
, HIF_WAIT
, holder_wait
, TASK_UNINTERRUPTIBLE
);
475 * rq_mutex - process a mutex request in the queue
476 * @gh: the glock holder
478 * Returns: 1 if the queue is blocked
481 static int rq_mutex(struct gfs2_holder
*gh
)
483 struct gfs2_glock
*gl
= gh
->gh_gl
;
485 list_del_init(&gh
->gh_list
);
486 /* gh->gh_error never examined. */
487 set_bit(GLF_LOCK
, &gl
->gl_flags
);
488 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
490 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
496 * rq_promote - process a promote request in the queue
497 * @gh: the glock holder
499 * Acquire a new inter-node lock, or change a lock state to more restrictive.
501 * Returns: 1 if the queue is blocked
504 static int rq_promote(struct gfs2_holder
*gh
)
506 struct gfs2_glock
*gl
= gh
->gh_gl
;
507 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
509 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
510 if (list_empty(&gl
->gl_holders
)) {
512 set_bit(GLF_LOCK
, &gl
->gl_flags
);
513 spin_unlock(&gl
->gl_spin
);
515 if (atomic_read(&sdp
->sd_reclaim_count
) >
516 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
517 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
518 gfs2_reclaim_glock(sdp
);
519 gfs2_reclaim_glock(sdp
);
522 gfs2_glock_xmote_th(gh
);
523 spin_lock(&gl
->gl_spin
);
528 if (list_empty(&gl
->gl_holders
)) {
529 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
530 set_bit(GLF_LOCK
, &gl
->gl_flags
);
532 struct gfs2_holder
*next_gh
;
533 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
535 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
537 if (next_gh
->gh_state
== LM_ST_EXCLUSIVE
)
541 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
543 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
545 gfs2_holder_dispose_or_wake(gh
);
551 * rq_demote - process a demote request in the queue
552 * @gh: the glock holder
554 * Returns: 1 if the queue is blocked
557 static int rq_demote(struct gfs2_holder
*gh
)
559 struct gfs2_glock
*gl
= gh
->gh_gl
;
561 if (!list_empty(&gl
->gl_holders
))
564 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
565 list_del_init(&gh
->gh_list
);
567 spin_unlock(&gl
->gl_spin
);
568 gfs2_holder_dispose_or_wake(gh
);
569 spin_lock(&gl
->gl_spin
);
572 set_bit(GLF_LOCK
, &gl
->gl_flags
);
573 spin_unlock(&gl
->gl_spin
);
575 if (gh
->gh_state
== LM_ST_UNLOCKED
||
576 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
577 gfs2_glock_drop_th(gl
);
579 gfs2_glock_xmote_th(gh
);
581 spin_lock(&gl
->gl_spin
);
588 * run_queue - process holder structures on a glock
592 static void run_queue(struct gfs2_glock
*gl
)
594 struct gfs2_holder
*gh
;
598 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
601 if (!list_empty(&gl
->gl_waiters1
)) {
602 gh
= list_entry(gl
->gl_waiters1
.next
,
603 struct gfs2_holder
, gh_list
);
605 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
606 blocked
= rq_mutex(gh
);
608 gfs2_assert_warn(gl
->gl_sbd
, 0);
610 } else if (!list_empty(&gl
->gl_waiters2
) &&
611 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
612 gh
= list_entry(gl
->gl_waiters2
.next
,
613 struct gfs2_holder
, gh_list
);
615 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
616 blocked
= rq_demote(gh
);
618 gfs2_assert_warn(gl
->gl_sbd
, 0);
620 } else if (!list_empty(&gl
->gl_waiters3
)) {
621 gh
= list_entry(gl
->gl_waiters3
.next
,
622 struct gfs2_holder
, gh_list
);
624 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
625 blocked
= rq_promote(gh
);
627 gfs2_assert_warn(gl
->gl_sbd
, 0);
638 * gfs2_glmutex_lock - acquire a local lock on a glock
641 * Gives caller exclusive access to manipulate a glock structure.
644 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
646 struct gfs2_holder gh
;
648 gfs2_holder_init(gl
, 0, 0, &gh
);
649 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
650 if (test_and_set_bit(HIF_WAIT
, &gh
.gh_iflags
))
653 spin_lock(&gl
->gl_spin
);
654 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
655 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
657 gl
->gl_owner
= current
;
658 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
659 clear_bit(HIF_WAIT
, &gh
.gh_iflags
);
661 wake_up_bit(&gh
.gh_iflags
, HIF_WAIT
);
663 spin_unlock(&gl
->gl_spin
);
666 gfs2_holder_uninit(&gh
);
670 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
673 * Returns: 1 if the glock is acquired
676 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
680 spin_lock(&gl
->gl_spin
);
681 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
684 gl
->gl_owner
= current
;
685 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
687 spin_unlock(&gl
->gl_spin
);
693 * gfs2_glmutex_unlock - release a local lock on a glock
698 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
700 spin_lock(&gl
->gl_spin
);
701 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
705 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
706 spin_unlock(&gl
->gl_spin
);
710 * handle_callback - add a demote request to a lock's queue
712 * @state: the state the caller wants us to change to
714 * Note: This may fail sliently if we are out of memory.
717 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
719 struct gfs2_holder
*gh
, *new_gh
= NULL
;
722 spin_lock(&gl
->gl_spin
);
724 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
725 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
726 gl
->gl_req_gh
!= gh
) {
727 if (gh
->gh_state
!= state
)
728 gh
->gh_state
= LM_ST_UNLOCKED
;
734 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
737 spin_unlock(&gl
->gl_spin
);
739 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_NOFS
);
742 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
743 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
744 set_bit(HIF_WAIT
, &new_gh
->gh_iflags
);
750 spin_unlock(&gl
->gl_spin
);
753 gfs2_holder_put(new_gh
);
757 * state_change - record that the glock is now in a different state
759 * @new_state the new state
763 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
767 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
768 held2
= (new_state
!= LM_ST_UNLOCKED
);
770 if (held1
!= held2
) {
777 gl
->gl_state
= new_state
;
781 * xmote_bh - Called after the lock module is done acquiring a lock
782 * @gl: The glock in question
783 * @ret: the int returned from the lock module
787 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
789 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
790 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
791 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
792 int prev_state
= gl
->gl_state
;
795 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
796 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
797 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
799 state_change(gl
, ret
& LM_OUT_ST_MASK
);
801 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
803 glops
->go_inval(gl
, DIO_METADATA
);
804 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
805 /* We might not want to do this here.
806 Look at moving to the inode glops. */
808 glops
->go_inval(gl
, 0);
811 /* Deal with each possible exit condition */
814 gl
->gl_stamp
= jiffies
;
815 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
816 spin_lock(&gl
->gl_spin
);
817 list_del_init(&gh
->gh_list
);
819 spin_unlock(&gl
->gl_spin
);
820 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
821 spin_lock(&gl
->gl_spin
);
822 list_del_init(&gh
->gh_list
);
823 if (gl
->gl_state
== gh
->gh_state
||
824 gl
->gl_state
== LM_ST_UNLOCKED
) {
827 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
828 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
829 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
830 gh
->gh_error
= GLR_TRYFAILED
;
832 spin_unlock(&gl
->gl_spin
);
834 if (ret
& LM_OUT_CANCELED
)
835 handle_callback(gl
, LM_ST_UNLOCKED
);
837 } else if (ret
& LM_OUT_CANCELED
) {
838 spin_lock(&gl
->gl_spin
);
839 list_del_init(&gh
->gh_list
);
840 gh
->gh_error
= GLR_CANCELED
;
841 spin_unlock(&gl
->gl_spin
);
843 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
844 spin_lock(&gl
->gl_spin
);
845 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
847 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
848 spin_unlock(&gl
->gl_spin
);
850 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
854 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
855 spin_lock(&gl
->gl_spin
);
856 list_del_init(&gh
->gh_list
);
857 gh
->gh_error
= GLR_TRYFAILED
;
858 spin_unlock(&gl
->gl_spin
);
861 if (gfs2_assert_withdraw(sdp
, 0) == -1)
862 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
865 if (glops
->go_xmote_bh
)
866 glops
->go_xmote_bh(gl
);
869 spin_lock(&gl
->gl_spin
);
870 gl
->gl_req_gh
= NULL
;
871 gl
->gl_req_bh
= NULL
;
872 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
874 spin_unlock(&gl
->gl_spin
);
880 gfs2_holder_dispose_or_wake(gh
);
884 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
885 * @gl: The glock in question
886 * @state: the requested state
887 * @flags: modifier flags to the lock call
891 void gfs2_glock_xmote_th(struct gfs2_holder
*gh
)
893 struct gfs2_glock
*gl
= gh
->gh_gl
;
894 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
895 int flags
= gh
->gh_flags
;
896 unsigned state
= gh
->gh_state
;
897 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
898 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
899 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
901 unsigned int lck_ret
;
903 if (glops
->go_xmote_th
)
904 glops
->go_xmote_th(gl
);
906 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
907 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
908 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
909 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
912 gl
->gl_req_bh
= xmote_bh
;
914 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
, lck_flags
);
916 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
919 if (lck_ret
& LM_OUT_ASYNC
)
920 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
922 xmote_bh(gl
, lck_ret
);
926 * drop_bh - Called after a lock module unlock completes
928 * @ret: the return status
930 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
931 * Doesn't drop the reference on the glock the top half took out
935 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
937 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
938 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
939 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
941 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
942 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
943 gfs2_assert_warn(sdp
, !ret
);
945 state_change(gl
, LM_ST_UNLOCKED
);
948 glops
->go_inval(gl
, DIO_METADATA
);
951 spin_lock(&gl
->gl_spin
);
952 list_del_init(&gh
->gh_list
);
954 spin_unlock(&gl
->gl_spin
);
957 spin_lock(&gl
->gl_spin
);
958 gl
->gl_req_gh
= NULL
;
959 gl
->gl_req_bh
= NULL
;
960 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
962 spin_unlock(&gl
->gl_spin
);
967 gfs2_holder_dispose_or_wake(gh
);
971 * gfs2_glock_drop_th - call into the lock module to unlock a lock
976 static void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
978 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
979 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
982 if (glops
->go_drop_th
)
983 glops
->go_drop_th(gl
);
985 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
986 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
987 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
990 gl
->gl_req_bh
= drop_bh
;
992 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
994 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1000 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1004 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1005 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1007 * Don't cancel GL_NOCANCEL requests.
1010 static void do_cancels(struct gfs2_holder
*gh
)
1012 struct gfs2_glock
*gl
= gh
->gh_gl
;
1014 spin_lock(&gl
->gl_spin
);
1016 while (gl
->gl_req_gh
!= gh
&&
1017 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1018 !list_empty(&gh
->gh_list
)) {
1019 if (gl
->gl_req_bh
&& !(gl
->gl_req_gh
&&
1020 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1021 spin_unlock(&gl
->gl_spin
);
1022 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1024 spin_lock(&gl
->gl_spin
);
1026 spin_unlock(&gl
->gl_spin
);
1028 spin_lock(&gl
->gl_spin
);
1032 spin_unlock(&gl
->gl_spin
);
1036 * glock_wait_internal - wait on a glock acquisition
1037 * @gh: the glock holder
1039 * Returns: 0 on success
1042 static int glock_wait_internal(struct gfs2_holder
*gh
)
1044 struct gfs2_glock
*gl
= gh
->gh_gl
;
1045 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1046 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1048 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1051 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1052 spin_lock(&gl
->gl_spin
);
1053 if (gl
->gl_req_gh
!= gh
&&
1054 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1055 !list_empty(&gh
->gh_list
)) {
1056 list_del_init(&gh
->gh_list
);
1057 gh
->gh_error
= GLR_TRYFAILED
;
1059 spin_unlock(&gl
->gl_spin
);
1060 return gh
->gh_error
;
1062 spin_unlock(&gl
->gl_spin
);
1065 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1070 return gh
->gh_error
;
1072 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1073 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
, gh
->gh_state
,
1076 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1077 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1079 if (glops
->go_lock
) {
1080 gh
->gh_error
= glops
->go_lock(gh
);
1082 spin_lock(&gl
->gl_spin
);
1083 list_del_init(&gh
->gh_list
);
1084 spin_unlock(&gl
->gl_spin
);
1088 spin_lock(&gl
->gl_spin
);
1089 gl
->gl_req_gh
= NULL
;
1090 gl
->gl_req_bh
= NULL
;
1091 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1093 spin_unlock(&gl
->gl_spin
);
1096 return gh
->gh_error
;
1099 static inline struct gfs2_holder
*
1100 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1102 struct gfs2_holder
*gh
;
1104 list_for_each_entry(gh
, head
, gh_list
) {
1105 if (gh
->gh_owner
== owner
)
1113 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1114 * @gh: the holder structure to add
1118 static void add_to_queue(struct gfs2_holder
*gh
)
1120 struct gfs2_glock
*gl
= gh
->gh_gl
;
1121 struct gfs2_holder
*existing
;
1123 BUG_ON(!gh
->gh_owner
);
1124 if (test_and_set_bit(HIF_WAIT
, &gh
->gh_iflags
))
1127 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1129 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1130 printk(KERN_INFO
"pid : %d\n", existing
->gh_owner
->pid
);
1131 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1132 existing
->gh_gl
->gl_name
.ln_type
, existing
->gh_gl
->gl_state
);
1133 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1134 printk(KERN_INFO
"pid : %d\n", gh
->gh_owner
->pid
);
1135 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1136 gl
->gl_name
.ln_type
, gl
->gl_state
);
1140 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1142 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1143 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1147 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1148 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1150 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1154 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1155 * @gh: the holder structure
1157 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1159 * Returns: 0, GLR_TRYFAILED, or errno on failure
1162 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1164 struct gfs2_glock
*gl
= gh
->gh_gl
;
1165 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1169 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1170 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1174 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1176 spin_lock(&gl
->gl_spin
);
1179 spin_unlock(&gl
->gl_spin
);
1181 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1182 error
= glock_wait_internal(gh
);
1183 if (error
== GLR_CANCELED
) {
1193 * gfs2_glock_poll - poll to see if an async request has been completed
1196 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1199 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1201 struct gfs2_glock
*gl
= gh
->gh_gl
;
1204 spin_lock(&gl
->gl_spin
);
1206 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1208 else if (list_empty(&gh
->gh_list
)) {
1209 if (gh
->gh_error
== GLR_CANCELED
) {
1210 spin_unlock(&gl
->gl_spin
);
1212 if (gfs2_glock_nq(gh
))
1219 spin_unlock(&gl
->gl_spin
);
1225 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1226 * @gh: the holder structure
1228 * Returns: 0, GLR_TRYFAILED, or errno on failure
1231 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1235 error
= glock_wait_internal(gh
);
1236 if (error
== GLR_CANCELED
) {
1238 gh
->gh_flags
&= ~GL_ASYNC
;
1239 error
= gfs2_glock_nq(gh
);
1246 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1247 * @gh: the glock holder
1251 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1253 struct gfs2_glock
*gl
= gh
->gh_gl
;
1254 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1256 if (gh
->gh_flags
& GL_NOCACHE
)
1257 handle_callback(gl
, LM_ST_UNLOCKED
);
1259 gfs2_glmutex_lock(gl
);
1261 spin_lock(&gl
->gl_spin
);
1262 list_del_init(&gh
->gh_list
);
1264 if (list_empty(&gl
->gl_holders
)) {
1265 spin_unlock(&gl
->gl_spin
);
1267 if (glops
->go_unlock
)
1268 glops
->go_unlock(gh
);
1270 gl
->gl_stamp
= jiffies
;
1272 spin_lock(&gl
->gl_spin
);
1275 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1277 spin_unlock(&gl
->gl_spin
);
1281 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1282 * @gh: the holder structure
1286 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1289 gfs2_holder_uninit(gh
);
1293 * gfs2_glock_nq_num - acquire a glock based on lock number
1294 * @sdp: the filesystem
1295 * @number: the lock number
1296 * @glops: the glock operations for the type of glock
1297 * @state: the state to acquire the glock in
1298 * @flags: modifier flags for the aquisition
1299 * @gh: the struct gfs2_holder
1304 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, u64 number
,
1305 const struct gfs2_glock_operations
*glops
,
1306 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1308 struct gfs2_glock
*gl
;
1311 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1313 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1321 * glock_compare - Compare two struct gfs2_glock structures for sorting
1322 * @arg_a: the first structure
1323 * @arg_b: the second structure
1327 static int glock_compare(const void *arg_a
, const void *arg_b
)
1329 const struct gfs2_holder
*gh_a
= *(const struct gfs2_holder
**)arg_a
;
1330 const struct gfs2_holder
*gh_b
= *(const struct gfs2_holder
**)arg_b
;
1331 const struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1332 const struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1334 if (a
->ln_number
> b
->ln_number
)
1336 if (a
->ln_number
< b
->ln_number
)
1338 BUG_ON(gh_a
->gh_gl
->gl_ops
->go_type
== gh_b
->gh_gl
->gl_ops
->go_type
);
1343 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1344 * @num_gh: the number of structures
1345 * @ghs: an array of struct gfs2_holder structures
1347 * Returns: 0 on success (all glocks acquired),
1348 * errno on failure (no glocks acquired)
1351 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1352 struct gfs2_holder
**p
)
1357 for (x
= 0; x
< num_gh
; x
++)
1360 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1362 for (x
= 0; x
< num_gh
; x
++) {
1363 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1365 error
= gfs2_glock_nq(p
[x
]);
1368 gfs2_glock_dq(p
[x
]);
1377 * gfs2_glock_nq_m - acquire multiple glocks
1378 * @num_gh: the number of structures
1379 * @ghs: an array of struct gfs2_holder structures
1381 * Figure out how big an impact this function has. Either:
1382 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1383 * 2) Forget async stuff and just call nq_m_sync()
1384 * 3) Leave it like it is
1386 * Returns: 0 on success (all glocks acquired),
1387 * errno on failure (no glocks acquired)
1390 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1394 int borked
= 0, serious
= 0;
1401 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1402 return gfs2_glock_nq(ghs
);
1405 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1409 for (x
= 0; x
< num_gh
; x
++) {
1410 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1411 error
= gfs2_glock_nq(&ghs
[x
]);
1420 for (x
= 0; x
< num_gh
; x
++) {
1421 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1424 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1434 for (x
= 0; x
< num_gh
; x
++)
1436 gfs2_glock_dq(&ghs
[x
]);
1441 for (x
= 0; x
< num_gh
; x
++)
1442 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1444 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1453 * gfs2_glock_dq_m - release multiple glocks
1454 * @num_gh: the number of structures
1455 * @ghs: an array of struct gfs2_holder structures
1459 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1463 for (x
= 0; x
< num_gh
; x
++)
1464 gfs2_glock_dq(&ghs
[x
]);
1468 * gfs2_glock_dq_uninit_m - release multiple glocks
1469 * @num_gh: the number of structures
1470 * @ghs: an array of struct gfs2_holder structures
1474 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1478 for (x
= 0; x
< num_gh
; x
++)
1479 gfs2_glock_dq_uninit(&ghs
[x
]);
1483 * gfs2_lvb_hold - attach a LVB from a glock
1484 * @gl: The glock in question
1488 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1492 gfs2_glmutex_lock(gl
);
1494 if (!atomic_read(&gl
->gl_lvb_count
)) {
1495 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1497 gfs2_glmutex_unlock(gl
);
1500 gfs2_glock_hold(gl
);
1502 atomic_inc(&gl
->gl_lvb_count
);
1504 gfs2_glmutex_unlock(gl
);
1510 * gfs2_lvb_unhold - detach a LVB from a glock
1511 * @gl: The glock in question
1515 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1517 gfs2_glock_hold(gl
);
1518 gfs2_glmutex_lock(gl
);
1520 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1521 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1522 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1527 gfs2_glmutex_unlock(gl
);
1531 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1534 struct gfs2_glock
*gl
;
1536 gl
= gfs2_glock_find(sdp
, name
);
1540 handle_callback(gl
, state
);
1542 spin_lock(&gl
->gl_spin
);
1544 spin_unlock(&gl
->gl_spin
);
1550 * gfs2_glock_cb - Callback used by locking module
1551 * @sdp: Pointer to the superblock
1552 * @type: Type of callback
1553 * @data: Type dependent data pointer
1555 * Called by the locking module when it wants to tell us something.
1556 * Either we need to drop a lock, one of our ASYNC requests completed, or
1557 * a journal from another client needs to be recovered.
1560 void gfs2_glock_cb(void *cb_data
, unsigned int type
, void *data
)
1562 struct gfs2_sbd
*sdp
= cb_data
;
1566 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1570 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1574 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1578 struct lm_async_cb
*async
= data
;
1579 struct gfs2_glock
*gl
;
1581 down_read(&gfs2_umount_flush_sem
);
1582 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1583 if (gfs2_assert_warn(sdp
, gl
))
1585 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1586 gl
->gl_req_bh(gl
, async
->lc_ret
);
1588 up_read(&gfs2_umount_flush_sem
);
1592 case LM_CB_NEED_RECOVERY
:
1593 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1594 if (sdp
->sd_recoverd_process
)
1595 wake_up_process(sdp
->sd_recoverd_process
);
1598 case LM_CB_DROPLOCKS
:
1599 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1600 gfs2_quota_scan(sdp
);
1604 gfs2_assert_warn(sdp
, 0);
1610 * demote_ok - Check to see if it's ok to unlock a glock
1613 * Returns: 1 if it's ok
1616 static int demote_ok(struct gfs2_glock
*gl
)
1618 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1621 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1623 else if (glops
->go_demote_ok
)
1624 demote
= glops
->go_demote_ok(gl
);
1630 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1635 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1637 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1639 spin_lock(&sdp
->sd_reclaim_lock
);
1640 if (list_empty(&gl
->gl_reclaim
)) {
1641 gfs2_glock_hold(gl
);
1642 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1643 atomic_inc(&sdp
->sd_reclaim_count
);
1645 spin_unlock(&sdp
->sd_reclaim_lock
);
1647 wake_up(&sdp
->sd_reclaim_wq
);
1651 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1652 * @sdp: the filesystem
1654 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1655 * different glock and we notice that there are a lot of glocks in the
1660 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1662 struct gfs2_glock
*gl
;
1664 spin_lock(&sdp
->sd_reclaim_lock
);
1665 if (list_empty(&sdp
->sd_reclaim_list
)) {
1666 spin_unlock(&sdp
->sd_reclaim_lock
);
1669 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1670 struct gfs2_glock
, gl_reclaim
);
1671 list_del_init(&gl
->gl_reclaim
);
1672 spin_unlock(&sdp
->sd_reclaim_lock
);
1674 atomic_dec(&sdp
->sd_reclaim_count
);
1675 atomic_inc(&sdp
->sd_reclaimed
);
1677 if (gfs2_glmutex_trylock(gl
)) {
1678 if (list_empty(&gl
->gl_holders
) &&
1679 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1680 handle_callback(gl
, LM_ST_UNLOCKED
);
1681 gfs2_glmutex_unlock(gl
);
1688 * examine_bucket - Call a function for glock in a hash bucket
1689 * @examiner: the function
1690 * @sdp: the filesystem
1691 * @bucket: the bucket
1693 * Returns: 1 if the bucket has entries
1696 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1699 struct gfs2_glock
*gl
, *prev
= NULL
;
1700 int has_entries
= 0;
1701 struct hlist_head
*head
= &gl_hash_table
[hash
].hb_list
;
1703 read_lock(gl_lock_addr(hash
));
1704 /* Can't use hlist_for_each_entry - don't want prefetch here */
1705 if (hlist_empty(head
))
1707 gl
= list_entry(head
->first
, struct gfs2_glock
, gl_list
);
1709 if (gl
->gl_sbd
== sdp
) {
1710 gfs2_glock_hold(gl
);
1711 read_unlock(gl_lock_addr(hash
));
1713 gfs2_glock_put(prev
);
1717 read_lock(gl_lock_addr(hash
));
1719 if (gl
->gl_list
.next
== NULL
)
1721 gl
= list_entry(gl
->gl_list
.next
, struct gfs2_glock
, gl_list
);
1724 read_unlock(gl_lock_addr(hash
));
1726 gfs2_glock_put(prev
);
1731 * scan_glock - look at a glock and see if we can reclaim it
1732 * @gl: the glock to look at
1736 static void scan_glock(struct gfs2_glock
*gl
)
1738 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
)
1741 if (gfs2_glmutex_trylock(gl
)) {
1742 if (list_empty(&gl
->gl_holders
) &&
1743 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1745 gfs2_glmutex_unlock(gl
);
1750 gfs2_glmutex_unlock(gl
);
1751 gfs2_glock_schedule_for_reclaim(gl
);
1755 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1756 * @sdp: the filesystem
1760 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1764 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
1765 examine_bucket(scan_glock
, sdp
, x
);
1769 * clear_glock - look at a glock and see if we can free it from glock cache
1770 * @gl: the glock to look at
1774 static void clear_glock(struct gfs2_glock
*gl
)
1776 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1779 spin_lock(&sdp
->sd_reclaim_lock
);
1780 if (!list_empty(&gl
->gl_reclaim
)) {
1781 list_del_init(&gl
->gl_reclaim
);
1782 atomic_dec(&sdp
->sd_reclaim_count
);
1783 spin_unlock(&sdp
->sd_reclaim_lock
);
1784 released
= gfs2_glock_put(gl
);
1785 gfs2_assert(sdp
, !released
);
1787 spin_unlock(&sdp
->sd_reclaim_lock
);
1790 if (gfs2_glmutex_trylock(gl
)) {
1791 if (list_empty(&gl
->gl_holders
) &&
1792 gl
->gl_state
!= LM_ST_UNLOCKED
)
1793 handle_callback(gl
, LM_ST_UNLOCKED
);
1794 gfs2_glmutex_unlock(gl
);
1799 * gfs2_gl_hash_clear - Empty out the glock hash table
1800 * @sdp: the filesystem
1801 * @wait: wait until it's all gone
1803 * Called when unmounting the filesystem, or when inter-node lock manager
1804 * requests DROPLOCKS because it is running out of capacity.
1807 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
1817 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1818 if (examine_bucket(clear_glock
, sdp
, x
))
1825 if (time_after_eq(jiffies
,
1826 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
1827 fs_warn(sdp
, "Unmount seems to be stalled. "
1828 "Dumping lock state...\n");
1829 gfs2_dump_lockstate(sdp
);
1833 down_write(&gfs2_umount_flush_sem
);
1834 invalidate_inodes(sdp
->sd_vfs
);
1835 up_write(&gfs2_umount_flush_sem
);
1841 * Diagnostic routines to help debug distributed deadlock
1845 * dump_holder - print information about a glock holder
1846 * @str: a string naming the type of holder
1847 * @gh: the glock holder
1849 * Returns: 0 on success, -ENOBUFS when we run out of space
1852 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
1855 int error
= -ENOBUFS
;
1857 printk(KERN_INFO
" %s\n", str
);
1858 printk(KERN_INFO
" owner = %ld\n",
1859 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
1860 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
1861 printk(KERN_INFO
" gh_flags =");
1862 for (x
= 0; x
< 32; x
++)
1863 if (gh
->gh_flags
& (1 << x
))
1866 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
1867 printk(KERN_INFO
" gh_iflags =");
1868 for (x
= 0; x
< 32; x
++)
1869 if (test_bit(x
, &gh
->gh_iflags
))
1872 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
1880 * dump_inode - print information about an inode
1883 * Returns: 0 on success, -ENOBUFS when we run out of space
1886 static int dump_inode(struct gfs2_inode
*ip
)
1889 int error
= -ENOBUFS
;
1891 printk(KERN_INFO
" Inode:\n");
1892 printk(KERN_INFO
" num = %llu %llu\n",
1893 (unsigned long long)ip
->i_num
.no_formal_ino
,
1894 (unsigned long long)ip
->i_num
.no_addr
);
1895 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_inode
.i_mode
));
1896 printk(KERN_INFO
" i_flags =");
1897 for (x
= 0; x
< 32; x
++)
1898 if (test_bit(x
, &ip
->i_flags
))
1908 * dump_glock - print information about a glock
1910 * @count: where we are in the buffer
1912 * Returns: 0 on success, -ENOBUFS when we run out of space
1915 static int dump_glock(struct gfs2_glock
*gl
)
1917 struct gfs2_holder
*gh
;
1919 int error
= -ENOBUFS
;
1921 spin_lock(&gl
->gl_spin
);
1923 printk(KERN_INFO
"Glock 0x%p (%u, %llu)\n", gl
, gl
->gl_name
.ln_type
,
1924 (unsigned long long)gl
->gl_name
.ln_number
);
1925 printk(KERN_INFO
" gl_flags =");
1926 for (x
= 0; x
< 32; x
++) {
1927 if (test_bit(x
, &gl
->gl_flags
))
1931 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
));
1932 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
1933 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
1934 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
1935 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
1936 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
1937 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
1938 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
1939 printk(KERN_INFO
" le = %s\n",
1940 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
1941 printk(KERN_INFO
" reclaim = %s\n",
1942 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
1944 printk(KERN_INFO
" aspace = 0x%p nrpages = %lu\n", gl
->gl_aspace
,
1945 gl
->gl_aspace
->i_mapping
->nrpages
);
1947 printk(KERN_INFO
" aspace = no\n");
1948 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
1949 if (gl
->gl_req_gh
) {
1950 error
= dump_holder("Request", gl
->gl_req_gh
);
1954 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1955 error
= dump_holder("Holder", gh
);
1959 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
1960 error
= dump_holder("Waiter1", gh
);
1964 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
1965 error
= dump_holder("Waiter2", gh
);
1969 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
1970 error
= dump_holder("Waiter3", gh
);
1974 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
1975 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
1976 list_empty(&gl
->gl_holders
)) {
1977 error
= dump_inode(gl
->gl_object
);
1982 printk(KERN_INFO
" Inode: busy\n");
1989 spin_unlock(&gl
->gl_spin
);
1994 * gfs2_dump_lockstate - print out the current lockstate
1995 * @sdp: the filesystem
1996 * @ub: the buffer to copy the information into
1998 * If @ub is NULL, dump the lockstate to the console.
2002 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2004 struct gfs2_glock
*gl
;
2005 struct hlist_node
*h
;
2009 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2011 read_lock(gl_lock_addr(x
));
2013 hlist_for_each_entry(gl
, h
, &gl_hash_table
[x
].hb_list
, gl_list
) {
2014 if (gl
->gl_sbd
!= sdp
)
2017 error
= dump_glock(gl
);
2022 read_unlock(gl_lock_addr(x
));
2032 int __init
gfs2_glock_init(void)
2035 for(i
= 0; i
< GFS2_GL_HASH_SIZE
; i
++) {
2036 INIT_HLIST_HEAD(&gl_hash_table
[i
].hb_list
);
2038 #ifdef GL_HASH_LOCK_SZ
2039 for(i
= 0; i
< GL_HASH_LOCK_SZ
; i
++) {
2040 rwlock_init(&gl_hash_locks
[i
]);