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 * search_bucket() - Find struct gfs2_glock by lock number
215 * @bucket: the bucket to search
216 * @name: The lock name
218 * Returns: NULL, or the struct gfs2_glock with the requested number
221 static struct gfs2_glock
*search_bucket(unsigned int hash
,
222 const struct gfs2_sbd
*sdp
,
223 const struct lm_lockname
*name
)
225 struct gfs2_glock
*gl
;
226 struct hlist_node
*h
;
228 hlist_for_each_entry(gl
, h
, &gl_hash_table
[hash
].hb_list
, gl_list
) {
229 if (!lm_name_equal(&gl
->gl_name
, name
))
231 if (gl
->gl_sbd
!= sdp
)
234 atomic_inc(&gl
->gl_ref
);
243 * gfs2_glock_find() - Find glock by lock number
244 * @sdp: The GFS2 superblock
245 * @name: The lock name
247 * Returns: NULL, or the struct gfs2_glock with the requested number
250 static struct gfs2_glock
*gfs2_glock_find(const struct gfs2_sbd
*sdp
,
251 const struct lm_lockname
*name
)
253 unsigned int hash
= gl_hash(sdp
, name
);
254 struct gfs2_glock
*gl
;
256 read_lock(gl_lock_addr(hash
));
257 gl
= search_bucket(hash
, sdp
, name
);
258 read_unlock(gl_lock_addr(hash
));
264 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
265 * @sdp: The GFS2 superblock
266 * @number: the lock number
267 * @glops: The glock_operations to use
268 * @create: If 0, don't create the glock if it doesn't exist
269 * @glp: the glock is returned here
271 * This does not lock a glock, just finds/creates structures for one.
276 int gfs2_glock_get(struct gfs2_sbd
*sdp
, u64 number
,
277 const struct gfs2_glock_operations
*glops
, int create
,
278 struct gfs2_glock
**glp
)
280 struct lm_lockname name
= { .ln_number
= number
, .ln_type
= glops
->go_type
};
281 struct gfs2_glock
*gl
, *tmp
;
282 unsigned int hash
= gl_hash(sdp
, &name
);
285 read_lock(gl_lock_addr(hash
));
286 gl
= search_bucket(hash
, sdp
, &name
);
287 read_unlock(gl_lock_addr(hash
));
294 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
300 atomic_set(&gl
->gl_ref
, 1);
301 gl
->gl_state
= LM_ST_UNLOCKED
;
306 gl
->gl_req_gh
= NULL
;
307 gl
->gl_req_bh
= NULL
;
309 gl
->gl_stamp
= jiffies
;
310 gl
->gl_object
= NULL
;
312 gl
->gl_aspace
= NULL
;
313 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
315 /* If this glock protects actual on-disk data or metadata blocks,
316 create a VFS inode to manage the pages/buffers holding them. */
317 if (glops
== &gfs2_inode_glops
|| glops
== &gfs2_rgrp_glops
) {
318 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
319 if (!gl
->gl_aspace
) {
325 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
329 write_lock(gl_lock_addr(hash
));
330 tmp
= search_bucket(hash
, sdp
, &name
);
332 write_unlock(gl_lock_addr(hash
));
336 hlist_add_head(&gl
->gl_list
, &gl_hash_table
[hash
].hb_list
);
337 write_unlock(gl_lock_addr(hash
));
346 gfs2_aspace_put(gl
->gl_aspace
);
348 kmem_cache_free(gfs2_glock_cachep
, gl
);
353 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
355 * @state: the state we're requesting
356 * @flags: the modifier flags
357 * @gh: the holder structure
361 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
362 struct gfs2_holder
*gh
)
364 INIT_LIST_HEAD(&gh
->gh_list
);
366 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
367 gh
->gh_owner
= current
;
368 gh
->gh_state
= state
;
369 gh
->gh_flags
= flags
;
376 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
377 * @state: the state we're requesting
378 * @flags: the modifier flags
379 * @gh: the holder structure
381 * Don't mess with the glock.
385 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
387 gh
->gh_state
= state
;
388 gh
->gh_flags
= flags
;
389 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
390 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
394 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
395 * @gh: the holder structure
399 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
401 gfs2_glock_put(gh
->gh_gl
);
407 * gfs2_holder_get - get a struct gfs2_holder structure
409 * @state: the state we're requesting
410 * @flags: the modifier flags
413 * Figure out how big an impact this function has. Either:
414 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
415 * 2) Leave it like it is
417 * Returns: the holder structure, NULL on ENOMEM
420 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
422 int flags
, gfp_t gfp_flags
)
424 struct gfs2_holder
*gh
;
426 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
430 gfs2_holder_init(gl
, state
, flags
, gh
);
431 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
432 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
437 * gfs2_holder_put - get rid of a struct gfs2_holder structure
438 * @gh: the holder structure
442 static void gfs2_holder_put(struct gfs2_holder
*gh
)
444 gfs2_holder_uninit(gh
);
448 static void gfs2_holder_dispose_or_wake(struct gfs2_holder
*gh
)
450 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
)) {
454 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
456 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
459 static int holder_wait(void *word
)
465 static void wait_on_holder(struct gfs2_holder
*gh
)
468 wait_on_bit(&gh
->gh_iflags
, HIF_WAIT
, holder_wait
, TASK_UNINTERRUPTIBLE
);
472 * rq_mutex - process a mutex request in the queue
473 * @gh: the glock holder
475 * Returns: 1 if the queue is blocked
478 static int rq_mutex(struct gfs2_holder
*gh
)
480 struct gfs2_glock
*gl
= gh
->gh_gl
;
482 list_del_init(&gh
->gh_list
);
483 /* gh->gh_error never examined. */
484 set_bit(GLF_LOCK
, &gl
->gl_flags
);
485 clear_bit(HIF_WAIT
, &gh
->gh_flags
);
487 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
493 * rq_promote - process a promote request in the queue
494 * @gh: the glock holder
496 * Acquire a new inter-node lock, or change a lock state to more restrictive.
498 * Returns: 1 if the queue is blocked
501 static int rq_promote(struct gfs2_holder
*gh
)
503 struct gfs2_glock
*gl
= gh
->gh_gl
;
504 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
506 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
507 if (list_empty(&gl
->gl_holders
)) {
509 set_bit(GLF_LOCK
, &gl
->gl_flags
);
510 spin_unlock(&gl
->gl_spin
);
512 if (atomic_read(&sdp
->sd_reclaim_count
) >
513 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
514 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
515 gfs2_reclaim_glock(sdp
);
516 gfs2_reclaim_glock(sdp
);
519 gfs2_glock_xmote_th(gh
);
520 spin_lock(&gl
->gl_spin
);
525 if (list_empty(&gl
->gl_holders
)) {
526 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
527 set_bit(GLF_LOCK
, &gl
->gl_flags
);
529 struct gfs2_holder
*next_gh
;
530 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
532 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
534 if (next_gh
->gh_state
== LM_ST_EXCLUSIVE
)
538 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
540 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
542 gfs2_holder_dispose_or_wake(gh
);
548 * rq_demote - process a demote request in the queue
549 * @gh: the glock holder
551 * Returns: 1 if the queue is blocked
554 static int rq_demote(struct gfs2_holder
*gh
)
556 struct gfs2_glock
*gl
= gh
->gh_gl
;
558 if (!list_empty(&gl
->gl_holders
))
561 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
562 list_del_init(&gh
->gh_list
);
564 spin_unlock(&gl
->gl_spin
);
565 gfs2_holder_dispose_or_wake(gh
);
566 spin_lock(&gl
->gl_spin
);
569 set_bit(GLF_LOCK
, &gl
->gl_flags
);
570 spin_unlock(&gl
->gl_spin
);
572 if (gh
->gh_state
== LM_ST_UNLOCKED
||
573 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
574 gfs2_glock_drop_th(gl
);
576 gfs2_glock_xmote_th(gh
);
578 spin_lock(&gl
->gl_spin
);
585 * run_queue - process holder structures on a glock
589 static void run_queue(struct gfs2_glock
*gl
)
591 struct gfs2_holder
*gh
;
595 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
598 if (!list_empty(&gl
->gl_waiters1
)) {
599 gh
= list_entry(gl
->gl_waiters1
.next
,
600 struct gfs2_holder
, gh_list
);
602 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
603 blocked
= rq_mutex(gh
);
605 gfs2_assert_warn(gl
->gl_sbd
, 0);
607 } else if (!list_empty(&gl
->gl_waiters2
) &&
608 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
609 gh
= list_entry(gl
->gl_waiters2
.next
,
610 struct gfs2_holder
, gh_list
);
612 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
613 blocked
= rq_demote(gh
);
615 gfs2_assert_warn(gl
->gl_sbd
, 0);
617 } else if (!list_empty(&gl
->gl_waiters3
)) {
618 gh
= list_entry(gl
->gl_waiters3
.next
,
619 struct gfs2_holder
, gh_list
);
621 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
622 blocked
= rq_promote(gh
);
624 gfs2_assert_warn(gl
->gl_sbd
, 0);
635 * gfs2_glmutex_lock - acquire a local lock on a glock
638 * Gives caller exclusive access to manipulate a glock structure.
641 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
643 struct gfs2_holder gh
;
645 gfs2_holder_init(gl
, 0, 0, &gh
);
646 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
647 if (test_and_set_bit(HIF_WAIT
, &gh
.gh_iflags
))
650 spin_lock(&gl
->gl_spin
);
651 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
652 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
654 gl
->gl_owner
= current
;
655 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
656 clear_bit(HIF_WAIT
, &gh
.gh_iflags
);
658 wake_up_bit(&gh
.gh_iflags
, HIF_WAIT
);
660 spin_unlock(&gl
->gl_spin
);
663 gfs2_holder_uninit(&gh
);
667 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
670 * Returns: 1 if the glock is acquired
673 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
677 spin_lock(&gl
->gl_spin
);
678 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
681 gl
->gl_owner
= current
;
682 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
684 spin_unlock(&gl
->gl_spin
);
690 * gfs2_glmutex_unlock - release a local lock on a glock
695 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
697 spin_lock(&gl
->gl_spin
);
698 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
702 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
703 spin_unlock(&gl
->gl_spin
);
707 * handle_callback - add a demote request to a lock's queue
709 * @state: the state the caller wants us to change to
711 * Note: This may fail sliently if we are out of memory.
714 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
716 struct gfs2_holder
*gh
, *new_gh
= NULL
;
719 spin_lock(&gl
->gl_spin
);
721 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
722 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
723 gl
->gl_req_gh
!= gh
) {
724 if (gh
->gh_state
!= state
)
725 gh
->gh_state
= LM_ST_UNLOCKED
;
731 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
734 spin_unlock(&gl
->gl_spin
);
736 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_NOFS
);
739 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
740 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
741 set_bit(HIF_WAIT
, &new_gh
->gh_iflags
);
747 spin_unlock(&gl
->gl_spin
);
750 gfs2_holder_put(new_gh
);
754 * state_change - record that the glock is now in a different state
756 * @new_state the new state
760 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
764 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
765 held2
= (new_state
!= LM_ST_UNLOCKED
);
767 if (held1
!= held2
) {
774 gl
->gl_state
= new_state
;
778 * xmote_bh - Called after the lock module is done acquiring a lock
779 * @gl: The glock in question
780 * @ret: the int returned from the lock module
784 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
786 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
787 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
788 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
789 int prev_state
= gl
->gl_state
;
792 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
793 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
794 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
796 state_change(gl
, ret
& LM_OUT_ST_MASK
);
798 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
800 glops
->go_inval(gl
, DIO_METADATA
);
801 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
802 /* We might not want to do this here.
803 Look at moving to the inode glops. */
805 glops
->go_inval(gl
, 0);
808 /* Deal with each possible exit condition */
811 gl
->gl_stamp
= jiffies
;
812 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
813 spin_lock(&gl
->gl_spin
);
814 list_del_init(&gh
->gh_list
);
816 spin_unlock(&gl
->gl_spin
);
817 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
818 spin_lock(&gl
->gl_spin
);
819 list_del_init(&gh
->gh_list
);
820 if (gl
->gl_state
== gh
->gh_state
||
821 gl
->gl_state
== LM_ST_UNLOCKED
) {
824 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
825 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
826 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
827 gh
->gh_error
= GLR_TRYFAILED
;
829 spin_unlock(&gl
->gl_spin
);
831 if (ret
& LM_OUT_CANCELED
)
832 handle_callback(gl
, LM_ST_UNLOCKED
);
834 } else if (ret
& LM_OUT_CANCELED
) {
835 spin_lock(&gl
->gl_spin
);
836 list_del_init(&gh
->gh_list
);
837 gh
->gh_error
= GLR_CANCELED
;
838 spin_unlock(&gl
->gl_spin
);
840 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
841 spin_lock(&gl
->gl_spin
);
842 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
844 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
845 spin_unlock(&gl
->gl_spin
);
847 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
851 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
852 spin_lock(&gl
->gl_spin
);
853 list_del_init(&gh
->gh_list
);
854 gh
->gh_error
= GLR_TRYFAILED
;
855 spin_unlock(&gl
->gl_spin
);
858 if (gfs2_assert_withdraw(sdp
, 0) == -1)
859 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
862 if (glops
->go_xmote_bh
)
863 glops
->go_xmote_bh(gl
);
866 spin_lock(&gl
->gl_spin
);
867 gl
->gl_req_gh
= NULL
;
868 gl
->gl_req_bh
= NULL
;
869 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
871 spin_unlock(&gl
->gl_spin
);
877 gfs2_holder_dispose_or_wake(gh
);
881 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
882 * @gl: The glock in question
883 * @state: the requested state
884 * @flags: modifier flags to the lock call
888 void gfs2_glock_xmote_th(struct gfs2_holder
*gh
)
890 struct gfs2_glock
*gl
= gh
->gh_gl
;
891 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
892 int flags
= gh
->gh_flags
;
893 unsigned state
= gh
->gh_state
;
894 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
895 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
896 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
898 unsigned int lck_ret
;
900 if (glops
->go_xmote_th
)
901 glops
->go_xmote_th(gl
);
903 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
904 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
905 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
906 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
909 gl
->gl_req_bh
= xmote_bh
;
911 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
, lck_flags
);
913 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
916 if (lck_ret
& LM_OUT_ASYNC
)
917 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
919 xmote_bh(gl
, lck_ret
);
923 * drop_bh - Called after a lock module unlock completes
925 * @ret: the return status
927 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
928 * Doesn't drop the reference on the glock the top half took out
932 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
934 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
935 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
936 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
938 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
939 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
940 gfs2_assert_warn(sdp
, !ret
);
942 state_change(gl
, LM_ST_UNLOCKED
);
945 glops
->go_inval(gl
, DIO_METADATA
);
948 spin_lock(&gl
->gl_spin
);
949 list_del_init(&gh
->gh_list
);
951 spin_unlock(&gl
->gl_spin
);
954 if (glops
->go_drop_bh
)
955 glops
->go_drop_bh(gl
);
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 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1582 if (gfs2_assert_warn(sdp
, gl
))
1584 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1585 gl
->gl_req_bh(gl
, async
->lc_ret
);
1590 case LM_CB_NEED_RECOVERY
:
1591 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1592 if (sdp
->sd_recoverd_process
)
1593 wake_up_process(sdp
->sd_recoverd_process
);
1596 case LM_CB_DROPLOCKS
:
1597 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1598 gfs2_quota_scan(sdp
);
1602 gfs2_assert_warn(sdp
, 0);
1608 * demote_ok - Check to see if it's ok to unlock a glock
1611 * Returns: 1 if it's ok
1614 static int demote_ok(struct gfs2_glock
*gl
)
1616 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1619 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1621 else if (glops
->go_demote_ok
)
1622 demote
= glops
->go_demote_ok(gl
);
1628 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1633 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1635 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1637 spin_lock(&sdp
->sd_reclaim_lock
);
1638 if (list_empty(&gl
->gl_reclaim
)) {
1639 gfs2_glock_hold(gl
);
1640 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1641 atomic_inc(&sdp
->sd_reclaim_count
);
1643 spin_unlock(&sdp
->sd_reclaim_lock
);
1645 wake_up(&sdp
->sd_reclaim_wq
);
1649 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1650 * @sdp: the filesystem
1652 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1653 * different glock and we notice that there are a lot of glocks in the
1658 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1660 struct gfs2_glock
*gl
;
1662 spin_lock(&sdp
->sd_reclaim_lock
);
1663 if (list_empty(&sdp
->sd_reclaim_list
)) {
1664 spin_unlock(&sdp
->sd_reclaim_lock
);
1667 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1668 struct gfs2_glock
, gl_reclaim
);
1669 list_del_init(&gl
->gl_reclaim
);
1670 spin_unlock(&sdp
->sd_reclaim_lock
);
1672 atomic_dec(&sdp
->sd_reclaim_count
);
1673 atomic_inc(&sdp
->sd_reclaimed
);
1675 if (gfs2_glmutex_trylock(gl
)) {
1676 if (list_empty(&gl
->gl_holders
) &&
1677 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1678 handle_callback(gl
, LM_ST_UNLOCKED
);
1679 gfs2_glmutex_unlock(gl
);
1686 * examine_bucket - Call a function for glock in a hash bucket
1687 * @examiner: the function
1688 * @sdp: the filesystem
1689 * @bucket: the bucket
1691 * Returns: 1 if the bucket has entries
1694 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1697 struct gfs2_glock
*gl
, *prev
= NULL
;
1698 int has_entries
= 0;
1699 struct hlist_head
*head
= &gl_hash_table
[hash
].hb_list
;
1701 read_lock(gl_lock_addr(hash
));
1702 /* Can't use hlist_for_each_entry - don't want prefetch here */
1703 if (hlist_empty(head
))
1705 gl
= list_entry(head
->first
, struct gfs2_glock
, gl_list
);
1707 if (gl
->gl_sbd
== sdp
) {
1708 gfs2_glock_hold(gl
);
1709 read_unlock(gl_lock_addr(hash
));
1711 gfs2_glock_put(prev
);
1715 read_lock(gl_lock_addr(hash
));
1717 if (gl
->gl_list
.next
== NULL
)
1719 gl
= list_entry(gl
->gl_list
.next
, struct gfs2_glock
, gl_list
);
1722 read_unlock(gl_lock_addr(hash
));
1724 gfs2_glock_put(prev
);
1729 * scan_glock - look at a glock and see if we can reclaim it
1730 * @gl: the glock to look at
1734 static void scan_glock(struct gfs2_glock
*gl
)
1736 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
)
1739 if (gfs2_glmutex_trylock(gl
)) {
1740 if (list_empty(&gl
->gl_holders
) &&
1741 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1743 gfs2_glmutex_unlock(gl
);
1748 gfs2_glmutex_unlock(gl
);
1749 gfs2_glock_schedule_for_reclaim(gl
);
1753 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1754 * @sdp: the filesystem
1758 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1762 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
1763 examine_bucket(scan_glock
, sdp
, x
);
1767 * clear_glock - look at a glock and see if we can free it from glock cache
1768 * @gl: the glock to look at
1772 static void clear_glock(struct gfs2_glock
*gl
)
1774 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1777 spin_lock(&sdp
->sd_reclaim_lock
);
1778 if (!list_empty(&gl
->gl_reclaim
)) {
1779 list_del_init(&gl
->gl_reclaim
);
1780 atomic_dec(&sdp
->sd_reclaim_count
);
1781 spin_unlock(&sdp
->sd_reclaim_lock
);
1782 released
= gfs2_glock_put(gl
);
1783 gfs2_assert(sdp
, !released
);
1785 spin_unlock(&sdp
->sd_reclaim_lock
);
1788 if (gfs2_glmutex_trylock(gl
)) {
1789 if (list_empty(gl
, &gl
->gl_holders
) &&
1790 gl
->gl_state
!= LM_ST_UNLOCKED
)
1791 handle_callback(gl
, LM_ST_UNLOCKED
);
1792 gfs2_glmutex_unlock(gl
);
1797 * gfs2_gl_hash_clear - Empty out the glock hash table
1798 * @sdp: the filesystem
1799 * @wait: wait until it's all gone
1801 * Called when unmounting the filesystem, or when inter-node lock manager
1802 * requests DROPLOCKS because it is running out of capacity.
1805 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
1815 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1816 if (examine_bucket(clear_glock
, sdp
, x
))
1823 if (time_after_eq(jiffies
,
1824 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
1825 fs_warn(sdp
, "Unmount seems to be stalled. "
1826 "Dumping lock state...\n");
1827 gfs2_dump_lockstate(sdp
);
1831 invalidate_inodes(sdp
->sd_vfs
);
1837 * Diagnostic routines to help debug distributed deadlock
1841 * dump_holder - print information about a glock holder
1842 * @str: a string naming the type of holder
1843 * @gh: the glock holder
1845 * Returns: 0 on success, -ENOBUFS when we run out of space
1848 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
1851 int error
= -ENOBUFS
;
1853 printk(KERN_INFO
" %s\n", str
);
1854 printk(KERN_INFO
" owner = %ld\n",
1855 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
1856 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
1857 printk(KERN_INFO
" gh_flags =");
1858 for (x
= 0; x
< 32; x
++)
1859 if (gh
->gh_flags
& (1 << x
))
1862 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
1863 printk(KERN_INFO
" gh_iflags =");
1864 for (x
= 0; x
< 32; x
++)
1865 if (test_bit(x
, &gh
->gh_iflags
))
1868 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
1876 * dump_inode - print information about an inode
1879 * Returns: 0 on success, -ENOBUFS when we run out of space
1882 static int dump_inode(struct gfs2_inode
*ip
)
1885 int error
= -ENOBUFS
;
1887 printk(KERN_INFO
" Inode:\n");
1888 printk(KERN_INFO
" num = %llu %llu\n",
1889 (unsigned long long)ip
->i_num
.no_formal_ino
,
1890 (unsigned long long)ip
->i_num
.no_addr
);
1891 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_inode
.i_mode
));
1892 printk(KERN_INFO
" i_flags =");
1893 for (x
= 0; x
< 32; x
++)
1894 if (test_bit(x
, &ip
->i_flags
))
1904 * dump_glock - print information about a glock
1906 * @count: where we are in the buffer
1908 * Returns: 0 on success, -ENOBUFS when we run out of space
1911 static int dump_glock(struct gfs2_glock
*gl
)
1913 struct gfs2_holder
*gh
;
1915 int error
= -ENOBUFS
;
1917 spin_lock(&gl
->gl_spin
);
1919 printk(KERN_INFO
"Glock 0x%p (%u, %llu)\n", gl
, gl
->gl_name
.ln_type
,
1920 (unsigned long long)gl
->gl_name
.ln_number
);
1921 printk(KERN_INFO
" gl_flags =");
1922 for (x
= 0; x
< 32; x
++) {
1923 if (test_bit(x
, &gl
->gl_flags
))
1927 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
));
1928 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
1929 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
1930 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
1931 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
1932 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
1933 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
1934 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
1935 printk(KERN_INFO
" le = %s\n",
1936 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
1937 printk(KERN_INFO
" reclaim = %s\n",
1938 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
1940 printk(KERN_INFO
" aspace = 0x%p nrpages = %lu\n", gl
->gl_aspace
,
1941 gl
->gl_aspace
->i_mapping
->nrpages
);
1943 printk(KERN_INFO
" aspace = no\n");
1944 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
1945 if (gl
->gl_req_gh
) {
1946 error
= dump_holder("Request", gl
->gl_req_gh
);
1950 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1951 error
= dump_holder("Holder", gh
);
1955 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
1956 error
= dump_holder("Waiter1", gh
);
1960 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
1961 error
= dump_holder("Waiter2", gh
);
1965 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
1966 error
= dump_holder("Waiter3", gh
);
1970 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
1971 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
1972 list_empty(&gl
->gl_holders
)) {
1973 error
= dump_inode(gl
->gl_object
);
1978 printk(KERN_INFO
" Inode: busy\n");
1985 spin_unlock(&gl
->gl_spin
);
1990 * gfs2_dump_lockstate - print out the current lockstate
1991 * @sdp: the filesystem
1992 * @ub: the buffer to copy the information into
1994 * If @ub is NULL, dump the lockstate to the console.
1998 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2000 struct gfs2_glock
*gl
;
2001 struct hlist_node
*h
;
2005 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2007 read_lock(gl_lock_addr(x
));
2009 hlist_for_each_entry(gl
, h
, &gl_hash_table
[x
].hb_list
, gl_list
) {
2010 if (gl
->gl_sbd
!= sdp
)
2013 error
= dump_glock(gl
);
2018 read_unlock(gl_lock_addr(x
));
2028 int __init
gfs2_glock_init(void)
2031 for(i
= 0; i
< GFS2_GL_HASH_SIZE
; i
++) {
2032 INIT_HLIST_HEAD(&gl_hash_table
[i
].hb_list
);
2034 #ifdef GL_HASH_LOCK_SZ
2035 for(i
= 0; i
< GL_HASH_LOCK_SZ
; i
++) {
2036 rwlock_init(&gl_hash_locks
[i
]);