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>
41 struct gfs2_gl_hash_bucket
{
42 struct hlist_head hb_list
;
46 int hash
; /* hash bucket index */
47 struct gfs2_sbd
*sdp
; /* incore superblock */
48 struct gfs2_glock
*gl
; /* current glock struct */
49 struct hlist_head
*hb_list
; /* current hash bucket ptr */
50 struct seq_file
*seq
; /* sequence file for debugfs */
51 char string
[512]; /* scratch space */
54 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
56 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
57 static void gfs2_glock_xmote_th(struct gfs2_holder
*gh
);
58 static void gfs2_glock_drop_th(struct gfs2_glock
*gl
);
59 static DECLARE_RWSEM(gfs2_umount_flush_sem
);
60 static struct dentry
*gfs2_root
;
62 #define GFS2_GL_HASH_SHIFT 15
63 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
64 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
66 static struct gfs2_gl_hash_bucket gl_hash_table
[GFS2_GL_HASH_SIZE
];
69 * Despite what you might think, the numbers below are not arbitrary :-)
70 * They are taken from the ipv4 routing hash code, which is well tested
71 * and thus should be nearly optimal. Later on we might tweek the numbers
72 * but for now this should be fine.
74 * The reason for putting the locks in a separate array from the list heads
75 * is that we can have fewer locks than list heads and save memory. We use
76 * the same hash function for both, but with a different hash mask.
78 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
79 defined(CONFIG_PROVE_LOCKING)
82 # define GL_HASH_LOCK_SZ 256
85 # define GL_HASH_LOCK_SZ 4096
87 # define GL_HASH_LOCK_SZ 2048
89 # define GL_HASH_LOCK_SZ 1024
91 # define GL_HASH_LOCK_SZ 512
93 # define GL_HASH_LOCK_SZ 256
97 /* We never want more locks than chains */
98 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
99 # undef GL_HASH_LOCK_SZ
100 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
103 static rwlock_t gl_hash_locks
[GL_HASH_LOCK_SZ
];
105 static inline rwlock_t
*gl_lock_addr(unsigned int x
)
107 return &gl_hash_locks
[x
& (GL_HASH_LOCK_SZ
-1)];
109 #else /* not SMP, so no spinlocks required */
110 static inline rwlock_t
*gl_lock_addr(unsigned int x
)
117 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
118 * @actual: the current state of the lock
119 * @requested: the lock state that was requested by the caller
120 * @flags: the modifier flags passed in by the caller
122 * Returns: 1 if the locks are compatible, 0 otherwise
125 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
128 if (actual
== requested
)
131 if (flags
& GL_EXACT
)
134 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
137 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
144 * gl_hash() - Turn glock number into hash bucket number
145 * @lock: The glock number
147 * Returns: The number of the corresponding hash bucket
150 static unsigned int gl_hash(const struct gfs2_sbd
*sdp
,
151 const struct lm_lockname
*name
)
155 h
= jhash(&name
->ln_number
, sizeof(u64
), 0);
156 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
157 h
= jhash(&sdp
, sizeof(struct gfs2_sbd
*), h
);
158 h
&= GFS2_GL_HASH_MASK
;
164 * glock_free() - Perform a few checks and then release struct gfs2_glock
165 * @gl: The glock to release
167 * Also calls lock module to release its internal structure for this glock.
171 static void glock_free(struct gfs2_glock
*gl
)
173 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
174 struct inode
*aspace
= gl
->gl_aspace
;
176 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
179 gfs2_aspace_put(aspace
);
181 kmem_cache_free(gfs2_glock_cachep
, gl
);
185 * gfs2_glock_hold() - increment reference count on glock
186 * @gl: The glock to hold
190 void gfs2_glock_hold(struct gfs2_glock
*gl
)
192 atomic_inc(&gl
->gl_ref
);
196 * gfs2_glock_put() - Decrement reference count on glock
197 * @gl: The glock to put
201 int gfs2_glock_put(struct gfs2_glock
*gl
)
204 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
206 write_lock(gl_lock_addr(gl
->gl_hash
));
207 if (atomic_dec_and_test(&gl
->gl_ref
)) {
208 hlist_del(&gl
->gl_list
);
209 write_unlock(gl_lock_addr(gl
->gl_hash
));
210 BUG_ON(spin_is_locked(&gl
->gl_spin
));
211 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
212 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
213 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
214 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
215 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
216 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
221 write_unlock(gl_lock_addr(gl
->gl_hash
));
227 * search_bucket() - Find struct gfs2_glock by lock number
228 * @bucket: the bucket to search
229 * @name: The lock name
231 * Returns: NULL, or the struct gfs2_glock with the requested number
234 static struct gfs2_glock
*search_bucket(unsigned int hash
,
235 const struct gfs2_sbd
*sdp
,
236 const struct lm_lockname
*name
)
238 struct gfs2_glock
*gl
;
239 struct hlist_node
*h
;
241 hlist_for_each_entry(gl
, h
, &gl_hash_table
[hash
].hb_list
, gl_list
) {
242 if (!lm_name_equal(&gl
->gl_name
, name
))
244 if (gl
->gl_sbd
!= sdp
)
247 atomic_inc(&gl
->gl_ref
);
256 * gfs2_glock_find() - Find glock by lock number
257 * @sdp: The GFS2 superblock
258 * @name: The lock name
260 * Returns: NULL, or the struct gfs2_glock with the requested number
263 static struct gfs2_glock
*gfs2_glock_find(const struct gfs2_sbd
*sdp
,
264 const struct lm_lockname
*name
)
266 unsigned int hash
= gl_hash(sdp
, name
);
267 struct gfs2_glock
*gl
;
269 read_lock(gl_lock_addr(hash
));
270 gl
= search_bucket(hash
, sdp
, name
);
271 read_unlock(gl_lock_addr(hash
));
277 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
278 * @sdp: The GFS2 superblock
279 * @number: the lock number
280 * @glops: The glock_operations to use
281 * @create: If 0, don't create the glock if it doesn't exist
282 * @glp: the glock is returned here
284 * This does not lock a glock, just finds/creates structures for one.
289 int gfs2_glock_get(struct gfs2_sbd
*sdp
, u64 number
,
290 const struct gfs2_glock_operations
*glops
, int create
,
291 struct gfs2_glock
**glp
)
293 struct lm_lockname name
= { .ln_number
= number
, .ln_type
= glops
->go_type
};
294 struct gfs2_glock
*gl
, *tmp
;
295 unsigned int hash
= gl_hash(sdp
, &name
);
298 read_lock(gl_lock_addr(hash
));
299 gl
= search_bucket(hash
, sdp
, &name
);
300 read_unlock(gl_lock_addr(hash
));
307 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
313 atomic_set(&gl
->gl_ref
, 1);
314 gl
->gl_state
= LM_ST_UNLOCKED
;
319 gl
->gl_req_gh
= NULL
;
320 gl
->gl_req_bh
= NULL
;
322 gl
->gl_stamp
= jiffies
;
323 gl
->gl_object
= NULL
;
325 gl
->gl_aspace
= NULL
;
326 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
328 /* If this glock protects actual on-disk data or metadata blocks,
329 create a VFS inode to manage the pages/buffers holding them. */
330 if (glops
== &gfs2_inode_glops
|| glops
== &gfs2_rgrp_glops
) {
331 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
332 if (!gl
->gl_aspace
) {
338 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
342 write_lock(gl_lock_addr(hash
));
343 tmp
= search_bucket(hash
, sdp
, &name
);
345 write_unlock(gl_lock_addr(hash
));
349 hlist_add_head(&gl
->gl_list
, &gl_hash_table
[hash
].hb_list
);
350 write_unlock(gl_lock_addr(hash
));
359 gfs2_aspace_put(gl
->gl_aspace
);
361 kmem_cache_free(gfs2_glock_cachep
, gl
);
366 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
368 * @state: the state we're requesting
369 * @flags: the modifier flags
370 * @gh: the holder structure
374 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
375 struct gfs2_holder
*gh
)
377 INIT_LIST_HEAD(&gh
->gh_list
);
379 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
380 gh
->gh_owner
= current
;
381 gh
->gh_state
= state
;
382 gh
->gh_flags
= flags
;
389 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
390 * @state: the state we're requesting
391 * @flags: the modifier flags
392 * @gh: the holder structure
394 * Don't mess with the glock.
398 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
400 gh
->gh_state
= state
;
401 gh
->gh_flags
= flags
;
402 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
403 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
407 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
408 * @gh: the holder structure
412 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
414 gfs2_glock_put(gh
->gh_gl
);
420 * gfs2_holder_get - get a struct gfs2_holder structure
422 * @state: the state we're requesting
423 * @flags: the modifier flags
426 * Figure out how big an impact this function has. Either:
427 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
428 * 2) Leave it like it is
430 * Returns: the holder structure, NULL on ENOMEM
433 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
435 int flags
, gfp_t gfp_flags
)
437 struct gfs2_holder
*gh
;
439 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
443 gfs2_holder_init(gl
, state
, flags
, gh
);
444 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
445 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
450 * gfs2_holder_put - get rid of a struct gfs2_holder structure
451 * @gh: the holder structure
455 static void gfs2_holder_put(struct gfs2_holder
*gh
)
457 gfs2_holder_uninit(gh
);
461 static void gfs2_holder_dispose_or_wake(struct gfs2_holder
*gh
)
463 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
)) {
467 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
469 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
472 static int holder_wait(void *word
)
478 static void wait_on_holder(struct gfs2_holder
*gh
)
481 wait_on_bit(&gh
->gh_iflags
, HIF_WAIT
, holder_wait
, TASK_UNINTERRUPTIBLE
);
485 * rq_mutex - process a mutex request in the queue
486 * @gh: the glock holder
488 * Returns: 1 if the queue is blocked
491 static int rq_mutex(struct gfs2_holder
*gh
)
493 struct gfs2_glock
*gl
= gh
->gh_gl
;
495 list_del_init(&gh
->gh_list
);
496 /* gh->gh_error never examined. */
497 set_bit(GLF_LOCK
, &gl
->gl_flags
);
498 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
500 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
506 * rq_promote - process a promote request in the queue
507 * @gh: the glock holder
509 * Acquire a new inter-node lock, or change a lock state to more restrictive.
511 * Returns: 1 if the queue is blocked
514 static int rq_promote(struct gfs2_holder
*gh
)
516 struct gfs2_glock
*gl
= gh
->gh_gl
;
517 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
519 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
520 if (list_empty(&gl
->gl_holders
)) {
522 set_bit(GLF_LOCK
, &gl
->gl_flags
);
523 spin_unlock(&gl
->gl_spin
);
525 if (atomic_read(&sdp
->sd_reclaim_count
) >
526 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
527 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
528 gfs2_reclaim_glock(sdp
);
529 gfs2_reclaim_glock(sdp
);
532 gfs2_glock_xmote_th(gh
);
533 spin_lock(&gl
->gl_spin
);
538 if (list_empty(&gl
->gl_holders
)) {
539 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
540 set_bit(GLF_LOCK
, &gl
->gl_flags
);
542 struct gfs2_holder
*next_gh
;
543 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
545 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
547 if (next_gh
->gh_state
== LM_ST_EXCLUSIVE
)
551 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
553 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
555 gfs2_holder_dispose_or_wake(gh
);
561 * rq_demote - process a demote request in the queue
562 * @gh: the glock holder
564 * Returns: 1 if the queue is blocked
567 static int rq_demote(struct gfs2_holder
*gh
)
569 struct gfs2_glock
*gl
= gh
->gh_gl
;
571 if (!list_empty(&gl
->gl_holders
))
574 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
575 list_del_init(&gh
->gh_list
);
577 spin_unlock(&gl
->gl_spin
);
578 gfs2_holder_dispose_or_wake(gh
);
579 spin_lock(&gl
->gl_spin
);
582 set_bit(GLF_LOCK
, &gl
->gl_flags
);
583 spin_unlock(&gl
->gl_spin
);
585 if (gh
->gh_state
== LM_ST_UNLOCKED
||
586 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
587 gfs2_glock_drop_th(gl
);
589 gfs2_glock_xmote_th(gh
);
591 spin_lock(&gl
->gl_spin
);
598 * run_queue - process holder structures on a glock
602 static void run_queue(struct gfs2_glock
*gl
)
604 struct gfs2_holder
*gh
;
608 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
611 if (!list_empty(&gl
->gl_waiters1
)) {
612 gh
= list_entry(gl
->gl_waiters1
.next
,
613 struct gfs2_holder
, gh_list
);
615 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
616 blocked
= rq_mutex(gh
);
618 gfs2_assert_warn(gl
->gl_sbd
, 0);
620 } else if (!list_empty(&gl
->gl_waiters2
) &&
621 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
622 gh
= list_entry(gl
->gl_waiters2
.next
,
623 struct gfs2_holder
, gh_list
);
625 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
626 blocked
= rq_demote(gh
);
628 gfs2_assert_warn(gl
->gl_sbd
, 0);
630 } else if (!list_empty(&gl
->gl_waiters3
)) {
631 gh
= list_entry(gl
->gl_waiters3
.next
,
632 struct gfs2_holder
, gh_list
);
634 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
635 blocked
= rq_promote(gh
);
637 gfs2_assert_warn(gl
->gl_sbd
, 0);
648 * gfs2_glmutex_lock - acquire a local lock on a glock
651 * Gives caller exclusive access to manipulate a glock structure.
654 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
656 struct gfs2_holder gh
;
658 gfs2_holder_init(gl
, 0, 0, &gh
);
659 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
660 if (test_and_set_bit(HIF_WAIT
, &gh
.gh_iflags
))
663 spin_lock(&gl
->gl_spin
);
664 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
665 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
667 gl
->gl_owner
= current
;
668 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
669 clear_bit(HIF_WAIT
, &gh
.gh_iflags
);
671 wake_up_bit(&gh
.gh_iflags
, HIF_WAIT
);
673 spin_unlock(&gl
->gl_spin
);
676 gfs2_holder_uninit(&gh
);
680 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
683 * Returns: 1 if the glock is acquired
686 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
690 spin_lock(&gl
->gl_spin
);
691 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
694 gl
->gl_owner
= current
;
695 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
697 spin_unlock(&gl
->gl_spin
);
703 * gfs2_glmutex_unlock - release a local lock on a glock
708 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
710 spin_lock(&gl
->gl_spin
);
711 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
715 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
716 spin_unlock(&gl
->gl_spin
);
720 * handle_callback - add a demote request to a lock's queue
722 * @state: the state the caller wants us to change to
724 * Note: This may fail sliently if we are out of memory.
727 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
729 struct gfs2_holder
*gh
, *new_gh
= NULL
;
732 spin_lock(&gl
->gl_spin
);
734 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
735 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
736 gl
->gl_req_gh
!= gh
) {
737 if (gh
->gh_state
!= state
)
738 gh
->gh_state
= LM_ST_UNLOCKED
;
744 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
747 spin_unlock(&gl
->gl_spin
);
749 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_NOFS
);
752 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
753 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
754 set_bit(HIF_WAIT
, &new_gh
->gh_iflags
);
760 spin_unlock(&gl
->gl_spin
);
763 gfs2_holder_put(new_gh
);
767 * state_change - record that the glock is now in a different state
769 * @new_state the new state
773 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
777 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
778 held2
= (new_state
!= LM_ST_UNLOCKED
);
780 if (held1
!= held2
) {
787 gl
->gl_state
= new_state
;
791 * xmote_bh - Called after the lock module is done acquiring a lock
792 * @gl: The glock in question
793 * @ret: the int returned from the lock module
797 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
799 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
800 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
801 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
802 int prev_state
= gl
->gl_state
;
805 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
806 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
807 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
809 state_change(gl
, ret
& LM_OUT_ST_MASK
);
811 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
813 glops
->go_inval(gl
, DIO_METADATA
);
814 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
815 /* We might not want to do this here.
816 Look at moving to the inode glops. */
818 glops
->go_inval(gl
, 0);
821 /* Deal with each possible exit condition */
824 gl
->gl_stamp
= jiffies
;
825 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
826 spin_lock(&gl
->gl_spin
);
827 list_del_init(&gh
->gh_list
);
829 spin_unlock(&gl
->gl_spin
);
830 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
831 spin_lock(&gl
->gl_spin
);
832 list_del_init(&gh
->gh_list
);
833 if (gl
->gl_state
== gh
->gh_state
||
834 gl
->gl_state
== LM_ST_UNLOCKED
) {
837 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
838 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
839 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
840 gh
->gh_error
= GLR_TRYFAILED
;
842 spin_unlock(&gl
->gl_spin
);
844 if (ret
& LM_OUT_CANCELED
)
845 handle_callback(gl
, LM_ST_UNLOCKED
);
847 } else if (ret
& LM_OUT_CANCELED
) {
848 spin_lock(&gl
->gl_spin
);
849 list_del_init(&gh
->gh_list
);
850 gh
->gh_error
= GLR_CANCELED
;
851 spin_unlock(&gl
->gl_spin
);
853 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
854 spin_lock(&gl
->gl_spin
);
855 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
857 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
858 spin_unlock(&gl
->gl_spin
);
860 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
864 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
865 spin_lock(&gl
->gl_spin
);
866 list_del_init(&gh
->gh_list
);
867 gh
->gh_error
= GLR_TRYFAILED
;
868 spin_unlock(&gl
->gl_spin
);
871 if (gfs2_assert_withdraw(sdp
, 0) == -1)
872 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
875 if (glops
->go_xmote_bh
)
876 glops
->go_xmote_bh(gl
);
879 spin_lock(&gl
->gl_spin
);
880 gl
->gl_req_gh
= NULL
;
881 gl
->gl_req_bh
= NULL
;
882 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
884 spin_unlock(&gl
->gl_spin
);
890 gfs2_holder_dispose_or_wake(gh
);
894 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
895 * @gl: The glock in question
896 * @state: the requested state
897 * @flags: modifier flags to the lock call
901 void gfs2_glock_xmote_th(struct gfs2_holder
*gh
)
903 struct gfs2_glock
*gl
= gh
->gh_gl
;
904 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
905 int flags
= gh
->gh_flags
;
906 unsigned state
= gh
->gh_state
;
907 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
908 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
909 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
911 unsigned int lck_ret
;
913 if (glops
->go_xmote_th
)
914 glops
->go_xmote_th(gl
);
916 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
917 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
918 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
919 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
922 gl
->gl_req_bh
= xmote_bh
;
924 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
, lck_flags
);
926 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
929 if (lck_ret
& LM_OUT_ASYNC
)
930 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
932 xmote_bh(gl
, lck_ret
);
936 * drop_bh - Called after a lock module unlock completes
938 * @ret: the return status
940 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
941 * Doesn't drop the reference on the glock the top half took out
945 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
947 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
948 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
949 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
951 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
952 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
953 gfs2_assert_warn(sdp
, !ret
);
955 state_change(gl
, LM_ST_UNLOCKED
);
958 glops
->go_inval(gl
, DIO_METADATA
);
961 spin_lock(&gl
->gl_spin
);
962 list_del_init(&gh
->gh_list
);
964 spin_unlock(&gl
->gl_spin
);
967 spin_lock(&gl
->gl_spin
);
968 gl
->gl_req_gh
= NULL
;
969 gl
->gl_req_bh
= NULL
;
970 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
972 spin_unlock(&gl
->gl_spin
);
977 gfs2_holder_dispose_or_wake(gh
);
981 * gfs2_glock_drop_th - call into the lock module to unlock a lock
986 static void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
988 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
989 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
992 if (glops
->go_drop_th
)
993 glops
->go_drop_th(gl
);
995 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
996 gfs2_assert_warn(sdp
, list_empty(&gl
->gl_holders
));
997 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1000 gl
->gl_req_bh
= drop_bh
;
1002 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1004 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1010 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1014 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1015 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1017 * Don't cancel GL_NOCANCEL requests.
1020 static void do_cancels(struct gfs2_holder
*gh
)
1022 struct gfs2_glock
*gl
= gh
->gh_gl
;
1024 spin_lock(&gl
->gl_spin
);
1026 while (gl
->gl_req_gh
!= gh
&&
1027 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1028 !list_empty(&gh
->gh_list
)) {
1029 if (gl
->gl_req_bh
&& !(gl
->gl_req_gh
&&
1030 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1031 spin_unlock(&gl
->gl_spin
);
1032 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1034 spin_lock(&gl
->gl_spin
);
1036 spin_unlock(&gl
->gl_spin
);
1038 spin_lock(&gl
->gl_spin
);
1042 spin_unlock(&gl
->gl_spin
);
1046 * glock_wait_internal - wait on a glock acquisition
1047 * @gh: the glock holder
1049 * Returns: 0 on success
1052 static int glock_wait_internal(struct gfs2_holder
*gh
)
1054 struct gfs2_glock
*gl
= gh
->gh_gl
;
1055 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1056 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1058 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1061 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1062 spin_lock(&gl
->gl_spin
);
1063 if (gl
->gl_req_gh
!= gh
&&
1064 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1065 !list_empty(&gh
->gh_list
)) {
1066 list_del_init(&gh
->gh_list
);
1067 gh
->gh_error
= GLR_TRYFAILED
;
1069 spin_unlock(&gl
->gl_spin
);
1070 return gh
->gh_error
;
1072 spin_unlock(&gl
->gl_spin
);
1075 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1080 return gh
->gh_error
;
1082 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1083 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
, gh
->gh_state
,
1086 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1087 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1089 if (glops
->go_lock
) {
1090 gh
->gh_error
= glops
->go_lock(gh
);
1092 spin_lock(&gl
->gl_spin
);
1093 list_del_init(&gh
->gh_list
);
1094 spin_unlock(&gl
->gl_spin
);
1098 spin_lock(&gl
->gl_spin
);
1099 gl
->gl_req_gh
= NULL
;
1100 gl
->gl_req_bh
= NULL
;
1101 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1103 spin_unlock(&gl
->gl_spin
);
1106 return gh
->gh_error
;
1109 static inline struct gfs2_holder
*
1110 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1112 struct gfs2_holder
*gh
;
1114 list_for_each_entry(gh
, head
, gh_list
) {
1115 if (gh
->gh_owner
== owner
)
1122 static void print_dbg(struct glock_iter
*gi
, const char *fmt
, ...)
1126 va_start(args
, fmt
);
1128 vsprintf(gi
->string
, fmt
, args
);
1129 seq_printf(gi
->seq
, gi
->string
);
1137 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1138 * @gh: the holder structure to add
1142 static void add_to_queue(struct gfs2_holder
*gh
)
1144 struct gfs2_glock
*gl
= gh
->gh_gl
;
1145 struct gfs2_holder
*existing
;
1147 BUG_ON(!gh
->gh_owner
);
1148 if (test_and_set_bit(HIF_WAIT
, &gh
->gh_iflags
))
1151 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1153 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1154 printk(KERN_INFO
"pid : %d\n", existing
->gh_owner
->pid
);
1155 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1156 existing
->gh_gl
->gl_name
.ln_type
, existing
->gh_gl
->gl_state
);
1157 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1158 printk(KERN_INFO
"pid : %d\n", gh
->gh_owner
->pid
);
1159 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1160 gl
->gl_name
.ln_type
, gl
->gl_state
);
1164 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1166 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1167 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1171 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1172 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1174 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1178 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1179 * @gh: the holder structure
1181 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1183 * Returns: 0, GLR_TRYFAILED, or errno on failure
1186 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1188 struct gfs2_glock
*gl
= gh
->gh_gl
;
1189 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1193 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1194 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1198 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1200 spin_lock(&gl
->gl_spin
);
1203 spin_unlock(&gl
->gl_spin
);
1205 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1206 error
= glock_wait_internal(gh
);
1207 if (error
== GLR_CANCELED
) {
1217 * gfs2_glock_poll - poll to see if an async request has been completed
1220 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1223 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1225 struct gfs2_glock
*gl
= gh
->gh_gl
;
1228 spin_lock(&gl
->gl_spin
);
1230 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1232 else if (list_empty(&gh
->gh_list
)) {
1233 if (gh
->gh_error
== GLR_CANCELED
) {
1234 spin_unlock(&gl
->gl_spin
);
1236 if (gfs2_glock_nq(gh
))
1243 spin_unlock(&gl
->gl_spin
);
1249 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1250 * @gh: the holder structure
1252 * Returns: 0, GLR_TRYFAILED, or errno on failure
1255 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1259 error
= glock_wait_internal(gh
);
1260 if (error
== GLR_CANCELED
) {
1262 gh
->gh_flags
&= ~GL_ASYNC
;
1263 error
= gfs2_glock_nq(gh
);
1270 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1271 * @gh: the glock holder
1275 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1277 struct gfs2_glock
*gl
= gh
->gh_gl
;
1278 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1280 if (gh
->gh_flags
& GL_NOCACHE
)
1281 handle_callback(gl
, LM_ST_UNLOCKED
);
1283 gfs2_glmutex_lock(gl
);
1285 spin_lock(&gl
->gl_spin
);
1286 list_del_init(&gh
->gh_list
);
1288 if (list_empty(&gl
->gl_holders
)) {
1289 spin_unlock(&gl
->gl_spin
);
1291 if (glops
->go_unlock
)
1292 glops
->go_unlock(gh
);
1294 gl
->gl_stamp
= jiffies
;
1296 spin_lock(&gl
->gl_spin
);
1299 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1301 spin_unlock(&gl
->gl_spin
);
1305 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1306 * @gh: the holder structure
1310 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1313 gfs2_holder_uninit(gh
);
1317 * gfs2_glock_nq_num - acquire a glock based on lock number
1318 * @sdp: the filesystem
1319 * @number: the lock number
1320 * @glops: the glock operations for the type of glock
1321 * @state: the state to acquire the glock in
1322 * @flags: modifier flags for the aquisition
1323 * @gh: the struct gfs2_holder
1328 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, u64 number
,
1329 const struct gfs2_glock_operations
*glops
,
1330 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1332 struct gfs2_glock
*gl
;
1335 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1337 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1345 * glock_compare - Compare two struct gfs2_glock structures for sorting
1346 * @arg_a: the first structure
1347 * @arg_b: the second structure
1351 static int glock_compare(const void *arg_a
, const void *arg_b
)
1353 const struct gfs2_holder
*gh_a
= *(const struct gfs2_holder
**)arg_a
;
1354 const struct gfs2_holder
*gh_b
= *(const struct gfs2_holder
**)arg_b
;
1355 const struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1356 const struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1358 if (a
->ln_number
> b
->ln_number
)
1360 if (a
->ln_number
< b
->ln_number
)
1362 BUG_ON(gh_a
->gh_gl
->gl_ops
->go_type
== gh_b
->gh_gl
->gl_ops
->go_type
);
1367 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1368 * @num_gh: the number of structures
1369 * @ghs: an array of struct gfs2_holder structures
1371 * Returns: 0 on success (all glocks acquired),
1372 * errno on failure (no glocks acquired)
1375 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1376 struct gfs2_holder
**p
)
1381 for (x
= 0; x
< num_gh
; x
++)
1384 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1386 for (x
= 0; x
< num_gh
; x
++) {
1387 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1389 error
= gfs2_glock_nq(p
[x
]);
1392 gfs2_glock_dq(p
[x
]);
1401 * gfs2_glock_nq_m - acquire multiple glocks
1402 * @num_gh: the number of structures
1403 * @ghs: an array of struct gfs2_holder structures
1405 * Figure out how big an impact this function has. Either:
1406 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1407 * 2) Forget async stuff and just call nq_m_sync()
1408 * 3) Leave it like it is
1410 * Returns: 0 on success (all glocks acquired),
1411 * errno on failure (no glocks acquired)
1414 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1418 int borked
= 0, serious
= 0;
1425 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1426 return gfs2_glock_nq(ghs
);
1429 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1433 for (x
= 0; x
< num_gh
; x
++) {
1434 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1435 error
= gfs2_glock_nq(&ghs
[x
]);
1444 for (x
= 0; x
< num_gh
; x
++) {
1445 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1448 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1458 for (x
= 0; x
< num_gh
; x
++)
1460 gfs2_glock_dq(&ghs
[x
]);
1465 for (x
= 0; x
< num_gh
; x
++)
1466 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1468 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1477 * gfs2_glock_dq_m - release multiple glocks
1478 * @num_gh: the number of structures
1479 * @ghs: an array of struct gfs2_holder structures
1483 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1487 for (x
= 0; x
< num_gh
; x
++)
1488 gfs2_glock_dq(&ghs
[x
]);
1492 * gfs2_glock_dq_uninit_m - release multiple glocks
1493 * @num_gh: the number of structures
1494 * @ghs: an array of struct gfs2_holder structures
1498 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1502 for (x
= 0; x
< num_gh
; x
++)
1503 gfs2_glock_dq_uninit(&ghs
[x
]);
1507 * gfs2_lvb_hold - attach a LVB from a glock
1508 * @gl: The glock in question
1512 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1516 gfs2_glmutex_lock(gl
);
1518 if (!atomic_read(&gl
->gl_lvb_count
)) {
1519 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1521 gfs2_glmutex_unlock(gl
);
1524 gfs2_glock_hold(gl
);
1526 atomic_inc(&gl
->gl_lvb_count
);
1528 gfs2_glmutex_unlock(gl
);
1534 * gfs2_lvb_unhold - detach a LVB from a glock
1535 * @gl: The glock in question
1539 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1541 gfs2_glock_hold(gl
);
1542 gfs2_glmutex_lock(gl
);
1544 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1545 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1546 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1551 gfs2_glmutex_unlock(gl
);
1555 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1558 struct gfs2_glock
*gl
;
1560 gl
= gfs2_glock_find(sdp
, name
);
1564 handle_callback(gl
, state
);
1566 spin_lock(&gl
->gl_spin
);
1568 spin_unlock(&gl
->gl_spin
);
1574 * gfs2_glock_cb - Callback used by locking module
1575 * @sdp: Pointer to the superblock
1576 * @type: Type of callback
1577 * @data: Type dependent data pointer
1579 * Called by the locking module when it wants to tell us something.
1580 * Either we need to drop a lock, one of our ASYNC requests completed, or
1581 * a journal from another client needs to be recovered.
1584 void gfs2_glock_cb(void *cb_data
, unsigned int type
, void *data
)
1586 struct gfs2_sbd
*sdp
= cb_data
;
1590 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1594 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1598 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1602 struct lm_async_cb
*async
= data
;
1603 struct gfs2_glock
*gl
;
1605 down_read(&gfs2_umount_flush_sem
);
1606 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1607 if (gfs2_assert_warn(sdp
, gl
))
1609 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1610 gl
->gl_req_bh(gl
, async
->lc_ret
);
1612 up_read(&gfs2_umount_flush_sem
);
1616 case LM_CB_NEED_RECOVERY
:
1617 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1618 if (sdp
->sd_recoverd_process
)
1619 wake_up_process(sdp
->sd_recoverd_process
);
1622 case LM_CB_DROPLOCKS
:
1623 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1624 gfs2_quota_scan(sdp
);
1628 gfs2_assert_warn(sdp
, 0);
1634 * demote_ok - Check to see if it's ok to unlock a glock
1637 * Returns: 1 if it's ok
1640 static int demote_ok(struct gfs2_glock
*gl
)
1642 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1645 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1647 else if (glops
->go_demote_ok
)
1648 demote
= glops
->go_demote_ok(gl
);
1654 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1659 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1661 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1663 spin_lock(&sdp
->sd_reclaim_lock
);
1664 if (list_empty(&gl
->gl_reclaim
)) {
1665 gfs2_glock_hold(gl
);
1666 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1667 atomic_inc(&sdp
->sd_reclaim_count
);
1669 spin_unlock(&sdp
->sd_reclaim_lock
);
1671 wake_up(&sdp
->sd_reclaim_wq
);
1675 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1676 * @sdp: the filesystem
1678 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1679 * different glock and we notice that there are a lot of glocks in the
1684 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1686 struct gfs2_glock
*gl
;
1688 spin_lock(&sdp
->sd_reclaim_lock
);
1689 if (list_empty(&sdp
->sd_reclaim_list
)) {
1690 spin_unlock(&sdp
->sd_reclaim_lock
);
1693 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1694 struct gfs2_glock
, gl_reclaim
);
1695 list_del_init(&gl
->gl_reclaim
);
1696 spin_unlock(&sdp
->sd_reclaim_lock
);
1698 atomic_dec(&sdp
->sd_reclaim_count
);
1699 atomic_inc(&sdp
->sd_reclaimed
);
1701 if (gfs2_glmutex_trylock(gl
)) {
1702 if (list_empty(&gl
->gl_holders
) &&
1703 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1704 handle_callback(gl
, LM_ST_UNLOCKED
);
1705 gfs2_glmutex_unlock(gl
);
1712 * examine_bucket - Call a function for glock in a hash bucket
1713 * @examiner: the function
1714 * @sdp: the filesystem
1715 * @bucket: the bucket
1717 * Returns: 1 if the bucket has entries
1720 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1723 struct gfs2_glock
*gl
, *prev
= NULL
;
1724 int has_entries
= 0;
1725 struct hlist_head
*head
= &gl_hash_table
[hash
].hb_list
;
1727 read_lock(gl_lock_addr(hash
));
1728 /* Can't use hlist_for_each_entry - don't want prefetch here */
1729 if (hlist_empty(head
))
1731 gl
= list_entry(head
->first
, struct gfs2_glock
, gl_list
);
1733 if (gl
->gl_sbd
== sdp
) {
1734 gfs2_glock_hold(gl
);
1735 read_unlock(gl_lock_addr(hash
));
1737 gfs2_glock_put(prev
);
1741 read_lock(gl_lock_addr(hash
));
1743 if (gl
->gl_list
.next
== NULL
)
1745 gl
= list_entry(gl
->gl_list
.next
, struct gfs2_glock
, gl_list
);
1748 read_unlock(gl_lock_addr(hash
));
1750 gfs2_glock_put(prev
);
1755 * scan_glock - look at a glock and see if we can reclaim it
1756 * @gl: the glock to look at
1760 static void scan_glock(struct gfs2_glock
*gl
)
1762 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
)
1765 if (gfs2_glmutex_trylock(gl
)) {
1766 if (list_empty(&gl
->gl_holders
) &&
1767 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1769 gfs2_glmutex_unlock(gl
);
1774 gfs2_glmutex_unlock(gl
);
1775 gfs2_glock_schedule_for_reclaim(gl
);
1779 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1780 * @sdp: the filesystem
1784 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1788 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
1789 examine_bucket(scan_glock
, sdp
, x
);
1793 * clear_glock - look at a glock and see if we can free it from glock cache
1794 * @gl: the glock to look at
1798 static void clear_glock(struct gfs2_glock
*gl
)
1800 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1803 spin_lock(&sdp
->sd_reclaim_lock
);
1804 if (!list_empty(&gl
->gl_reclaim
)) {
1805 list_del_init(&gl
->gl_reclaim
);
1806 atomic_dec(&sdp
->sd_reclaim_count
);
1807 spin_unlock(&sdp
->sd_reclaim_lock
);
1808 released
= gfs2_glock_put(gl
);
1809 gfs2_assert(sdp
, !released
);
1811 spin_unlock(&sdp
->sd_reclaim_lock
);
1814 if (gfs2_glmutex_trylock(gl
)) {
1815 if (list_empty(&gl
->gl_holders
) &&
1816 gl
->gl_state
!= LM_ST_UNLOCKED
)
1817 handle_callback(gl
, LM_ST_UNLOCKED
);
1818 gfs2_glmutex_unlock(gl
);
1823 * gfs2_gl_hash_clear - Empty out the glock hash table
1824 * @sdp: the filesystem
1825 * @wait: wait until it's all gone
1827 * Called when unmounting the filesystem, or when inter-node lock manager
1828 * requests DROPLOCKS because it is running out of capacity.
1831 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
1841 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1842 if (examine_bucket(clear_glock
, sdp
, x
))
1849 if (time_after_eq(jiffies
,
1850 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
1851 fs_warn(sdp
, "Unmount seems to be stalled. "
1852 "Dumping lock state...\n");
1853 gfs2_dump_lockstate(sdp
);
1857 down_write(&gfs2_umount_flush_sem
);
1858 invalidate_inodes(sdp
->sd_vfs
);
1859 up_write(&gfs2_umount_flush_sem
);
1865 * Diagnostic routines to help debug distributed deadlock
1869 * dump_holder - print information about a glock holder
1870 * @str: a string naming the type of holder
1871 * @gh: the glock holder
1873 * Returns: 0 on success, -ENOBUFS when we run out of space
1876 static int dump_holder(struct glock_iter
*gi
, char *str
,
1877 struct gfs2_holder
*gh
)
1881 print_dbg(gi
, " %s\n", str
);
1882 print_dbg(gi
, " owner = %ld\n",
1883 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
1884 print_dbg(gi
, " gh_state = %u\n", gh
->gh_state
);
1885 print_dbg(gi
, " gh_flags =");
1886 for (x
= 0; x
< 32; x
++)
1887 if (gh
->gh_flags
& (1 << x
))
1888 print_dbg(gi
, " %u", x
);
1889 print_dbg(gi
, " \n");
1890 print_dbg(gi
, " error = %d\n", gh
->gh_error
);
1891 print_dbg(gi
, " gh_iflags =");
1892 for (x
= 0; x
< 32; x
++)
1893 if (test_bit(x
, &gh
->gh_iflags
))
1894 print_dbg(gi
, " %u", x
);
1895 print_dbg(gi
, " \n");
1897 print_dbg(gi
, " initialized at: 0x%x\n", gh
->gh_ip
);
1899 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
1905 * dump_inode - print information about an inode
1908 * Returns: 0 on success, -ENOBUFS when we run out of space
1911 static int dump_inode(struct glock_iter
*gi
, struct gfs2_inode
*ip
)
1915 print_dbg(gi
, " Inode:\n");
1916 print_dbg(gi
, " num = %llu/%llu\n",
1917 ip
->i_num
.no_formal_ino
, ip
->i_num
.no_addr
);
1918 print_dbg(gi
, " type = %u\n", IF2DT(ip
->i_inode
.i_mode
));
1919 print_dbg(gi
, " i_flags =");
1920 for (x
= 0; x
< 32; x
++)
1921 if (test_bit(x
, &ip
->i_flags
))
1922 print_dbg(gi
, " %u", x
);
1923 print_dbg(gi
, " \n");
1928 * dump_glock - print information about a glock
1930 * @count: where we are in the buffer
1932 * Returns: 0 on success, -ENOBUFS when we run out of space
1935 static int dump_glock(struct glock_iter
*gi
, struct gfs2_glock
*gl
)
1937 struct gfs2_holder
*gh
;
1939 int error
= -ENOBUFS
;
1941 spin_lock(&gl
->gl_spin
);
1943 print_dbg(gi
, "Glock 0x%p (%u, %llu)\n", gl
, gl
->gl_name
.ln_type
,
1944 (unsigned long long)gl
->gl_name
.ln_number
);
1945 print_dbg(gi
, " gl_flags =");
1946 for (x
= 0; x
< 32; x
++) {
1947 if (test_bit(x
, &gl
->gl_flags
))
1948 print_dbg(gi
, " %u", x
);
1950 print_dbg(gi
, " \n");
1951 print_dbg(gi
, " gl_ref = %d\n", atomic_read(&gl
->gl_ref
));
1952 print_dbg(gi
, " gl_state = %u\n", gl
->gl_state
);
1953 print_dbg(gi
, " gl_owner = %s\n", gl
->gl_owner
->comm
);
1954 print_dbg(gi
, " gl_ip = %lu\n", gl
->gl_ip
);
1955 print_dbg(gi
, " req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
1956 print_dbg(gi
, " req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
1957 print_dbg(gi
, " lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
1958 print_dbg(gi
, " object = %s\n", (gl
->gl_object
) ? "yes" : "no");
1959 print_dbg(gi
, " le = %s\n",
1960 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
1961 print_dbg(gi
, " reclaim = %s\n",
1962 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
1964 print_dbg(gi
, " aspace = 0x%p nrpages = %lu\n", gl
->gl_aspace
,
1965 gl
->gl_aspace
->i_mapping
->nrpages
);
1967 print_dbg(gi
, " aspace = no\n");
1968 print_dbg(gi
, " ail = %d\n", atomic_read(&gl
->gl_ail_count
));
1969 if (gl
->gl_req_gh
) {
1970 error
= dump_holder(gi
, "Request", gl
->gl_req_gh
);
1974 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1975 error
= dump_holder(gi
, "Holder", gh
);
1979 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
1980 error
= dump_holder(gi
, "Waiter1", gh
);
1984 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
1985 error
= dump_holder(gi
, "Waiter2", gh
);
1989 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
1990 error
= dump_holder(gi
, "Waiter3", gh
);
1994 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
1995 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
1996 list_empty(&gl
->gl_holders
)) {
1997 error
= dump_inode(gi
, gl
->gl_object
);
2002 print_dbg(gi
, " Inode: busy\n");
2009 spin_unlock(&gl
->gl_spin
);
2014 * gfs2_dump_lockstate - print out the current lockstate
2015 * @sdp: the filesystem
2016 * @ub: the buffer to copy the information into
2018 * If @ub is NULL, dump the lockstate to the console.
2022 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2024 struct gfs2_glock
*gl
;
2025 struct hlist_node
*h
;
2029 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2031 read_lock(gl_lock_addr(x
));
2033 hlist_for_each_entry(gl
, h
, &gl_hash_table
[x
].hb_list
, gl_list
) {
2034 if (gl
->gl_sbd
!= sdp
)
2037 error
= dump_glock(NULL
, gl
);
2042 read_unlock(gl_lock_addr(x
));
2052 int __init
gfs2_glock_init(void)
2055 for(i
= 0; i
< GFS2_GL_HASH_SIZE
; i
++) {
2056 INIT_HLIST_HEAD(&gl_hash_table
[i
].hb_list
);
2058 #ifdef GL_HASH_LOCK_SZ
2059 for(i
= 0; i
< GL_HASH_LOCK_SZ
; i
++) {
2060 rwlock_init(&gl_hash_locks
[i
]);
2066 static int gfs2_glock_iter_next(struct glock_iter
*gi
)
2069 if (!gi
->hb_list
) { /* If we don't have a hash bucket yet */
2070 gi
->hb_list
= &gl_hash_table
[gi
->hash
].hb_list
;
2071 if (hlist_empty(gi
->hb_list
)) {
2074 if (gi
->hash
>= GFS2_GL_HASH_SIZE
)
2079 if (!hlist_empty(gi
->hb_list
)) {
2080 gi
->gl
= list_entry(gi
->hb_list
->first
,
2085 if (gi
->gl
->gl_list
.next
== NULL
) {
2090 gi
->gl
= list_entry(gi
->gl
->gl_list
.next
,
2091 struct gfs2_glock
, gl_list
);
2099 static void gfs2_glock_iter_free(struct glock_iter
*gi
)
2104 static struct glock_iter
*gfs2_glock_iter_init(struct gfs2_sbd
*sdp
)
2106 struct glock_iter
*gi
;
2108 gi
= kmalloc(sizeof (*gi
), GFP_KERNEL
);
2117 memset(gi
->string
, 0, sizeof(gi
->string
));
2119 if (gfs2_glock_iter_next(gi
)) {
2120 gfs2_glock_iter_free(gi
);
2127 static void *gfs2_glock_seq_start(struct seq_file
*file
, loff_t
*pos
)
2129 struct glock_iter
*gi
;
2132 gi
= gfs2_glock_iter_init(file
->private);
2137 if (gfs2_glock_iter_next(gi
)) {
2138 gfs2_glock_iter_free(gi
);
2146 static void *gfs2_glock_seq_next(struct seq_file
*file
, void *iter_ptr
,
2149 struct glock_iter
*gi
= iter_ptr
;
2153 if (gfs2_glock_iter_next(gi
)) {
2154 gfs2_glock_iter_free(gi
);
2161 static void gfs2_glock_seq_stop(struct seq_file
*file
, void *iter_ptr
)
2163 /* nothing for now */
2166 static int gfs2_glock_seq_show(struct seq_file
*file
, void *iter_ptr
)
2168 struct glock_iter
*gi
= iter_ptr
;
2171 dump_glock(gi
, gi
->gl
);
2176 static struct seq_operations gfs2_glock_seq_ops
= {
2177 .start
= gfs2_glock_seq_start
,
2178 .next
= gfs2_glock_seq_next
,
2179 .stop
= gfs2_glock_seq_stop
,
2180 .show
= gfs2_glock_seq_show
,
2183 static int gfs2_debugfs_open(struct inode
*inode
, struct file
*file
)
2185 struct seq_file
*seq
;
2188 ret
= seq_open(file
, &gfs2_glock_seq_ops
);
2192 seq
= file
->private_data
;
2193 seq
->private = inode
->i_private
;
2198 static const struct file_operations gfs2_debug_fops
= {
2199 .owner
= THIS_MODULE
,
2200 .open
= gfs2_debugfs_open
,
2202 .llseek
= seq_lseek
,
2203 .release
= seq_release
2206 int gfs2_create_debugfs_file(struct gfs2_sbd
*sdp
)
2208 sdp
->debugfs_dentry
= debugfs_create_file(sdp
->sd_table_name
,
2212 if (!sdp
->debugfs_dentry
)
2218 void gfs2_delete_debugfs_file(struct gfs2_sbd
*sdp
)
2220 if (sdp
->debugfs_dentry
)
2221 debugfs_remove(sdp
->debugfs_dentry
);
2224 int gfs2_register_debugfs(void)
2226 gfs2_root
= debugfs_create_dir("gfs2", NULL
);
2227 return gfs2_root
? 0 : -ENOMEM
;
2230 void gfs2_unregister_debugfs(void)
2232 debugfs_remove(gfs2_root
);