2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2005 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 v.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/kref.h>
19 #include <linux/kallsyms.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <asm/semaphore.h>
22 #include <asm/uaccess.h>
25 #include "lm_interface.h"
37 /* Must be kept in sync with the beginning of struct gfs2_glock */
39 struct list_head gl_list
;
40 unsigned long gl_flags
;
44 struct gfs2_holder gr_gh
;
45 struct work_struct gr_work
;
48 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
50 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
53 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
54 * @actual: the current state of the lock
55 * @requested: the lock state that was requested by the caller
56 * @flags: the modifier flags passed in by the caller
58 * Returns: 1 if the locks are compatible, 0 otherwise
61 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
64 if (actual
== requested
)
70 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
73 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
80 * gl_hash() - Turn glock number into hash bucket number
81 * @lock: The glock number
83 * Returns: The number of the corresponding hash bucket
86 static unsigned int gl_hash(struct lm_lockname
*name
)
90 h
= jhash(&name
->ln_number
, sizeof(uint64_t), 0);
91 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
92 h
&= GFS2_GL_HASH_MASK
;
98 * glock_free() - Perform a few checks and then release struct gfs2_glock
99 * @gl: The glock to release
101 * Also calls lock module to release its internal structure for this glock.
105 static void glock_free(struct gfs2_glock
*gl
)
107 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
108 struct inode
*aspace
= gl
->gl_aspace
;
110 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
113 gfs2_aspace_put(aspace
);
115 kmem_cache_free(gfs2_glock_cachep
, gl
);
119 * gfs2_glock_hold() - increment reference count on glock
120 * @gl: The glock to hold
124 void gfs2_glock_hold(struct gfs2_glock
*gl
)
126 kref_get(&gl
->gl_ref
);
129 /* All work is done after the return from kref_put() so we
130 can release the write_lock before the free. */
132 static void kill_glock(struct kref
*kref
)
134 struct gfs2_glock
*gl
= container_of(kref
, struct gfs2_glock
, gl_ref
);
135 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
137 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
138 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
139 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
140 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
141 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
142 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
146 * gfs2_glock_put() - Decrement reference count on glock
147 * @gl: The glock to put
151 int gfs2_glock_put(struct gfs2_glock
*gl
)
153 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
154 struct gfs2_gl_hash_bucket
*bucket
= gl
->gl_bucket
;
157 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
159 write_lock(&bucket
->hb_lock
);
160 if (kref_put(&gl
->gl_ref
, kill_glock
)) {
161 list_del_init(&gl
->gl_list
);
162 write_unlock(&bucket
->hb_lock
);
163 BUG_ON(spin_is_locked(&gl
->gl_spin
));
168 write_unlock(&bucket
->hb_lock
);
170 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
175 * queue_empty - check to see if a glock's queue is empty
177 * @head: the head of the queue to check
179 * This function protects the list in the event that a process already
180 * has a holder on the list and is adding a second holder for itself.
181 * The glmutex lock is what generally prevents processes from working
182 * on the same glock at once, but the special case of adding a second
183 * holder for yourself ("recursive" locking) doesn't involve locking
184 * glmutex, making the spin lock necessary.
186 * Returns: 1 if the queue is empty
189 static inline int queue_empty(struct gfs2_glock
*gl
, struct list_head
*head
)
192 spin_lock(&gl
->gl_spin
);
193 empty
= list_empty(head
);
194 spin_unlock(&gl
->gl_spin
);
199 * search_bucket() - Find struct gfs2_glock by lock number
200 * @bucket: the bucket to search
201 * @name: The lock name
203 * Returns: NULL, or the struct gfs2_glock with the requested number
206 static struct gfs2_glock
*search_bucket(struct gfs2_gl_hash_bucket
*bucket
,
207 struct lm_lockname
*name
)
209 struct gfs2_glock
*gl
;
211 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
212 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
214 if (!lm_name_equal(&gl
->gl_name
, name
))
217 kref_get(&gl
->gl_ref
);
226 * gfs2_glock_find() - Find glock by lock number
227 * @sdp: The GFS2 superblock
228 * @name: The lock name
230 * Returns: NULL, or the struct gfs2_glock with the requested number
233 static struct gfs2_glock
*gfs2_glock_find(struct gfs2_sbd
*sdp
,
234 struct lm_lockname
*name
)
236 struct gfs2_gl_hash_bucket
*bucket
= &sdp
->sd_gl_hash
[gl_hash(name
)];
237 struct gfs2_glock
*gl
;
239 read_lock(&bucket
->hb_lock
);
240 gl
= search_bucket(bucket
, name
);
241 read_unlock(&bucket
->hb_lock
);
247 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
248 * @sdp: The GFS2 superblock
249 * @number: the lock number
250 * @glops: The glock_operations to use
251 * @create: If 0, don't create the glock if it doesn't exist
252 * @glp: the glock is returned here
254 * This does not lock a glock, just finds/creates structures for one.
259 int gfs2_glock_get(struct gfs2_sbd
*sdp
, uint64_t number
,
260 struct gfs2_glock_operations
*glops
, int create
,
261 struct gfs2_glock
**glp
)
263 struct lm_lockname name
;
264 struct gfs2_glock
*gl
, *tmp
;
265 struct gfs2_gl_hash_bucket
*bucket
;
268 name
.ln_number
= number
;
269 name
.ln_type
= glops
->go_type
;
270 bucket
= &sdp
->sd_gl_hash
[gl_hash(&name
)];
272 read_lock(&bucket
->hb_lock
);
273 gl
= search_bucket(bucket
, &name
);
274 read_unlock(&bucket
->hb_lock
);
281 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
285 memset(gl
, 0, sizeof(struct gfs2_glock
));
287 INIT_LIST_HEAD(&gl
->gl_list
);
289 kref_init(&gl
->gl_ref
);
291 spin_lock_init(&gl
->gl_spin
);
293 gl
->gl_state
= LM_ST_UNLOCKED
;
294 INIT_LIST_HEAD(&gl
->gl_holders
);
295 INIT_LIST_HEAD(&gl
->gl_waiters1
);
296 INIT_LIST_HEAD(&gl
->gl_waiters2
);
297 INIT_LIST_HEAD(&gl
->gl_waiters3
);
301 gl
->gl_bucket
= bucket
;
302 INIT_LIST_HEAD(&gl
->gl_reclaim
);
306 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
307 INIT_LIST_HEAD(&gl
->gl_ail_list
);
309 /* If this glock protects actual on-disk data or metadata blocks,
310 create a VFS inode to manage the pages/buffers holding them. */
311 if (glops
== &gfs2_inode_glops
||
312 glops
== &gfs2_rgrp_glops
||
313 glops
== &gfs2_meta_glops
) {
314 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
315 if (!gl
->gl_aspace
) {
321 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
325 write_lock(&bucket
->hb_lock
);
326 tmp
= search_bucket(bucket
, &name
);
328 write_unlock(&bucket
->hb_lock
);
332 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
333 write_unlock(&bucket
->hb_lock
);
342 gfs2_aspace_put(gl
->gl_aspace
);
345 kmem_cache_free(gfs2_glock_cachep
, gl
);
351 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
353 * @state: the state we're requesting
354 * @flags: the modifier flags
355 * @gh: the holder structure
359 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
360 struct gfs2_holder
*gh
)
362 INIT_LIST_HEAD(&gh
->gh_list
);
364 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
365 gh
->gh_owner
= current
;
366 gh
->gh_state
= state
;
367 gh
->gh_flags
= flags
;
370 init_completion(&gh
->gh_wait
);
372 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
373 gh
->gh_flags
|= GL_LOCAL_EXCL
;
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 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
393 gh
->gh_flags
|= GL_LOCAL_EXCL
;
395 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
396 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
400 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
401 * @gh: the holder structure
405 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
407 gfs2_glock_put(gh
->gh_gl
);
413 * gfs2_holder_get - get a struct gfs2_holder structure
415 * @state: the state we're requesting
416 * @flags: the modifier flags
417 * @gfp_flags: __GFP_NOFAIL
419 * Figure out how big an impact this function has. Either:
420 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
421 * 2) Leave it like it is
423 * Returns: the holder structure, NULL on ENOMEM
426 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
428 int flags
, gfp_t gfp_flags
)
430 struct gfs2_holder
*gh
;
432 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
436 gfs2_holder_init(gl
, state
, flags
, gh
);
437 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
438 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
443 * gfs2_holder_put - get rid of a struct gfs2_holder structure
444 * @gh: the holder structure
448 static void gfs2_holder_put(struct gfs2_holder
*gh
)
450 gfs2_holder_uninit(gh
);
455 * rq_mutex - process a mutex request in the queue
456 * @gh: the glock holder
458 * Returns: 1 if the queue is blocked
461 static int rq_mutex(struct gfs2_holder
*gh
)
463 struct gfs2_glock
*gl
= gh
->gh_gl
;
465 list_del_init(&gh
->gh_list
);
466 /* gh->gh_error never examined. */
467 set_bit(GLF_LOCK
, &gl
->gl_flags
);
468 complete(&gh
->gh_wait
);
474 * rq_promote - process a promote request in the queue
475 * @gh: the glock holder
477 * Acquire a new inter-node lock, or change a lock state to more restrictive.
479 * Returns: 1 if the queue is blocked
482 static int rq_promote(struct gfs2_holder
*gh
)
484 struct gfs2_glock
*gl
= gh
->gh_gl
;
485 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
486 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
488 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
489 if (list_empty(&gl
->gl_holders
)) {
491 set_bit(GLF_LOCK
, &gl
->gl_flags
);
492 spin_unlock(&gl
->gl_spin
);
494 if (atomic_read(&sdp
->sd_reclaim_count
) >
495 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
496 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
497 gfs2_reclaim_glock(sdp
);
498 gfs2_reclaim_glock(sdp
);
501 glops
->go_xmote_th(gl
, gh
->gh_state
,
504 spin_lock(&gl
->gl_spin
);
509 if (list_empty(&gl
->gl_holders
)) {
510 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
511 set_bit(GLF_LOCK
, &gl
->gl_flags
);
513 struct gfs2_holder
*next_gh
;
514 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
516 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
518 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
522 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
524 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
526 complete(&gh
->gh_wait
);
532 * rq_demote - process a demote request in the queue
533 * @gh: the glock holder
535 * Returns: 1 if the queue is blocked
538 static int rq_demote(struct gfs2_holder
*gh
)
540 struct gfs2_glock
*gl
= gh
->gh_gl
;
541 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
543 if (!list_empty(&gl
->gl_holders
))
546 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
547 list_del_init(&gh
->gh_list
);
549 spin_unlock(&gl
->gl_spin
);
550 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
553 complete(&gh
->gh_wait
);
554 spin_lock(&gl
->gl_spin
);
557 set_bit(GLF_LOCK
, &gl
->gl_flags
);
558 spin_unlock(&gl
->gl_spin
);
560 if (gh
->gh_state
== LM_ST_UNLOCKED
||
561 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
562 glops
->go_drop_th(gl
);
564 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
566 spin_lock(&gl
->gl_spin
);
573 * rq_greedy - process a queued request to drop greedy status
574 * @gh: the glock holder
576 * Returns: 1 if the queue is blocked
579 static int rq_greedy(struct gfs2_holder
*gh
)
581 struct gfs2_glock
*gl
= gh
->gh_gl
;
583 list_del_init(&gh
->gh_list
);
584 /* gh->gh_error never examined. */
585 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
586 spin_unlock(&gl
->gl_spin
);
588 gfs2_holder_uninit(gh
);
589 kfree(container_of(gh
, struct greedy
, gr_gh
));
591 spin_lock(&gl
->gl_spin
);
597 * run_queue - process holder structures on a glock
601 static void run_queue(struct gfs2_glock
*gl
)
603 struct gfs2_holder
*gh
;
607 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
610 if (!list_empty(&gl
->gl_waiters1
)) {
611 gh
= list_entry(gl
->gl_waiters1
.next
,
612 struct gfs2_holder
, gh_list
);
614 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
615 blocked
= rq_mutex(gh
);
617 gfs2_assert_warn(gl
->gl_sbd
, 0);
619 } else if (!list_empty(&gl
->gl_waiters2
) &&
620 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
621 gh
= list_entry(gl
->gl_waiters2
.next
,
622 struct gfs2_holder
, gh_list
);
624 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
625 blocked
= rq_demote(gh
);
626 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
627 blocked
= rq_greedy(gh
);
629 gfs2_assert_warn(gl
->gl_sbd
, 0);
631 } else if (!list_empty(&gl
->gl_waiters3
)) {
632 gh
= list_entry(gl
->gl_waiters3
.next
,
633 struct gfs2_holder
, gh_list
);
635 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
636 blocked
= rq_promote(gh
);
638 gfs2_assert_warn(gl
->gl_sbd
, 0);
649 * gfs2_glmutex_lock - acquire a local lock on a glock
652 * Gives caller exclusive access to manipulate a glock structure.
655 void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
657 struct gfs2_holder gh
;
659 gfs2_holder_init(gl
, 0, 0, &gh
);
660 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
662 spin_lock(&gl
->gl_spin
);
663 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
664 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
666 complete(&gh
.gh_wait
);
667 spin_unlock(&gl
->gl_spin
);
669 wait_for_completion(&gh
.gh_wait
);
670 gfs2_holder_uninit(&gh
);
674 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
677 * Returns: 1 if the glock is acquired
680 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
684 spin_lock(&gl
->gl_spin
);
685 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
687 spin_unlock(&gl
->gl_spin
);
693 * gfs2_glmutex_unlock - release a local lock on a glock
698 void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
700 spin_lock(&gl
->gl_spin
);
701 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
703 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
704 spin_unlock(&gl
->gl_spin
);
708 * handle_callback - add a demote request to a lock's queue
710 * @state: the state the caller wants us to change to
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
,
737 GFP_KERNEL
| __GFP_NOFAIL
),
738 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
739 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
745 spin_unlock(&gl
->gl_spin
);
748 gfs2_holder_put(new_gh
);
752 * state_change - record that the glock is now in a different state
754 * @new_state the new state
758 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
762 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
763 held2
= (new_state
!= LM_ST_UNLOCKED
);
765 if (held1
!= held2
) {
772 gl
->gl_state
= new_state
;
776 * xmote_bh - Called after the lock module is done acquiring a lock
777 * @gl: The glock in question
778 * @ret: the int returned from the lock module
782 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
784 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
785 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
786 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
787 int prev_state
= gl
->gl_state
;
790 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
791 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
792 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
794 state_change(gl
, ret
& LM_OUT_ST_MASK
);
796 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
798 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
799 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
800 /* We might not want to do this here.
801 Look at moving to the inode glops. */
803 glops
->go_inval(gl
, DIO_DATA
);
806 /* Deal with each possible exit condition */
809 gl
->gl_stamp
= jiffies
;
811 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
812 spin_lock(&gl
->gl_spin
);
813 list_del_init(&gh
->gh_list
);
815 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
); /* Lame */
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 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
880 complete(&gh
->gh_wait
);
885 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
886 * @gl: The glock in question
887 * @state: the requested state
888 * @flags: modifier flags to the lock call
892 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
894 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
895 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
896 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
897 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
899 unsigned int lck_ret
;
901 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
902 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
903 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
904 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
906 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
909 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
913 gl
->gl_req_bh
= xmote_bh
;
915 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
,
918 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
921 if (lck_ret
& LM_OUT_ASYNC
)
922 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
924 xmote_bh(gl
, lck_ret
);
928 * drop_bh - Called after a lock module unlock completes
930 * @ret: the return status
932 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
933 * Doesn't drop the reference on the glock the top half took out
937 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
939 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
940 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
941 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
943 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
945 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
946 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
947 gfs2_assert_warn(sdp
, !ret
);
949 state_change(gl
, LM_ST_UNLOCKED
);
952 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
955 spin_lock(&gl
->gl_spin
);
956 list_del_init(&gh
->gh_list
);
958 spin_unlock(&gl
->gl_spin
);
961 if (glops
->go_drop_bh
)
962 glops
->go_drop_bh(gl
);
964 spin_lock(&gl
->gl_spin
);
965 gl
->gl_req_gh
= NULL
;
966 gl
->gl_req_bh
= NULL
;
967 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
969 spin_unlock(&gl
->gl_spin
);
974 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
977 complete(&gh
->gh_wait
);
982 * gfs2_glock_drop_th - call into the lock module to unlock a lock
987 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
989 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
990 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
993 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
994 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
995 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
997 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1000 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1003 gfs2_glock_hold(gl
);
1004 gl
->gl_req_bh
= drop_bh
;
1006 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1008 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1014 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1018 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1019 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1021 * Don't cancel GL_NOCANCEL requests.
1024 static void do_cancels(struct gfs2_holder
*gh
)
1026 struct gfs2_glock
*gl
= gh
->gh_gl
;
1028 spin_lock(&gl
->gl_spin
);
1030 while (gl
->gl_req_gh
!= gh
&&
1031 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1032 !list_empty(&gh
->gh_list
)) {
1033 if (gl
->gl_req_bh
&&
1035 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1036 spin_unlock(&gl
->gl_spin
);
1037 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1039 spin_lock(&gl
->gl_spin
);
1041 spin_unlock(&gl
->gl_spin
);
1043 spin_lock(&gl
->gl_spin
);
1047 spin_unlock(&gl
->gl_spin
);
1051 * glock_wait_internal - wait on a glock acquisition
1052 * @gh: the glock holder
1054 * Returns: 0 on success
1057 static int glock_wait_internal(struct gfs2_holder
*gh
)
1059 struct gfs2_glock
*gl
= gh
->gh_gl
;
1060 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1061 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1063 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1066 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1067 spin_lock(&gl
->gl_spin
);
1068 if (gl
->gl_req_gh
!= gh
&&
1069 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1070 !list_empty(&gh
->gh_list
)) {
1071 list_del_init(&gh
->gh_list
);
1072 gh
->gh_error
= GLR_TRYFAILED
;
1074 spin_unlock(&gl
->gl_spin
);
1075 return gh
->gh_error
;
1077 spin_unlock(&gl
->gl_spin
);
1080 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1083 wait_for_completion(&gh
->gh_wait
);
1086 return gh
->gh_error
;
1088 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1089 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1093 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1094 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1096 if (glops
->go_lock
) {
1097 gh
->gh_error
= glops
->go_lock(gh
);
1099 spin_lock(&gl
->gl_spin
);
1100 list_del_init(&gh
->gh_list
);
1101 spin_unlock(&gl
->gl_spin
);
1105 spin_lock(&gl
->gl_spin
);
1106 gl
->gl_req_gh
= NULL
;
1107 gl
->gl_req_bh
= NULL
;
1108 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1110 spin_unlock(&gl
->gl_spin
);
1113 return gh
->gh_error
;
1116 static inline struct gfs2_holder
*
1117 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1119 struct gfs2_holder
*gh
;
1121 list_for_each_entry(gh
, head
, gh_list
) {
1122 if (gh
->gh_owner
== owner
)
1130 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1131 * @gh: the holder structure to add
1135 static void add_to_queue(struct gfs2_holder
*gh
)
1137 struct gfs2_glock
*gl
= gh
->gh_gl
;
1138 struct gfs2_holder
*existing
;
1140 BUG_ON(!gh
->gh_owner
);
1142 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1144 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1145 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1149 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1151 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1152 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1156 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1157 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1159 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1163 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1164 * @gh: the holder structure
1166 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1168 * Returns: 0, GLR_TRYFAILED, or errno on failure
1171 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1173 struct gfs2_glock
*gl
= gh
->gh_gl
;
1174 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1178 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1179 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1183 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1185 spin_lock(&gl
->gl_spin
);
1188 spin_unlock(&gl
->gl_spin
);
1190 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1191 error
= glock_wait_internal(gh
);
1192 if (error
== GLR_CANCELED
) {
1198 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1204 * gfs2_glock_poll - poll to see if an async request has been completed
1207 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1210 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1212 struct gfs2_glock
*gl
= gh
->gh_gl
;
1215 spin_lock(&gl
->gl_spin
);
1217 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1219 else if (list_empty(&gh
->gh_list
)) {
1220 if (gh
->gh_error
== GLR_CANCELED
) {
1221 spin_unlock(&gl
->gl_spin
);
1223 if (gfs2_glock_nq(gh
))
1230 spin_unlock(&gl
->gl_spin
);
1236 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1237 * @gh: the holder structure
1239 * Returns: 0, GLR_TRYFAILED, or errno on failure
1242 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1246 error
= glock_wait_internal(gh
);
1247 if (error
== GLR_CANCELED
) {
1249 gh
->gh_flags
&= ~GL_ASYNC
;
1250 error
= gfs2_glock_nq(gh
);
1257 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1258 * @gh: the glock holder
1262 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1264 struct gfs2_glock
*gl
= gh
->gh_gl
;
1265 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1267 if (gh
->gh_flags
& GL_SYNC
)
1268 set_bit(GLF_SYNC
, &gl
->gl_flags
);
1270 if (gh
->gh_flags
& GL_NOCACHE
)
1271 handle_callback(gl
, LM_ST_UNLOCKED
);
1273 gfs2_glmutex_lock(gl
);
1275 spin_lock(&gl
->gl_spin
);
1276 list_del_init(&gh
->gh_list
);
1278 if (list_empty(&gl
->gl_holders
)) {
1279 spin_unlock(&gl
->gl_spin
);
1281 if (glops
->go_unlock
)
1282 glops
->go_unlock(gh
);
1284 if (test_bit(GLF_SYNC
, &gl
->gl_flags
)) {
1286 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
);
1289 gl
->gl_stamp
= jiffies
;
1291 spin_lock(&gl
->gl_spin
);
1294 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1296 spin_unlock(&gl
->gl_spin
);
1300 * gfs2_glock_prefetch - Try to prefetch a glock
1302 * @state: the state to prefetch in
1303 * @flags: flags passed to go_xmote_th()
1307 static void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
,
1310 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1312 spin_lock(&gl
->gl_spin
);
1314 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1315 !list_empty(&gl
->gl_holders
) ||
1316 !list_empty(&gl
->gl_waiters1
) ||
1317 !list_empty(&gl
->gl_waiters2
) ||
1318 !list_empty(&gl
->gl_waiters3
) ||
1319 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1320 spin_unlock(&gl
->gl_spin
);
1324 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1325 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1326 spin_unlock(&gl
->gl_spin
);
1328 glops
->go_xmote_th(gl
, state
, flags
);
1331 static void greedy_work(void *data
)
1333 struct greedy
*gr
= data
;
1334 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1335 struct gfs2_glock
*gl
= gh
->gh_gl
;
1336 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1338 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1340 if (glops
->go_greedy
)
1341 glops
->go_greedy(gl
);
1343 spin_lock(&gl
->gl_spin
);
1345 if (list_empty(&gl
->gl_waiters2
)) {
1346 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1347 spin_unlock(&gl
->gl_spin
);
1348 gfs2_holder_uninit(gh
);
1351 gfs2_glock_hold(gl
);
1352 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1354 spin_unlock(&gl
->gl_spin
);
1360 * gfs2_glock_be_greedy -
1364 * Returns: 0 if go_greedy will be called, 1 otherwise
1367 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1370 struct gfs2_holder
*gh
;
1373 gl
->gl_sbd
->sd_args
.ar_localcaching
||
1374 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1377 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1379 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1384 gfs2_holder_init(gl
, 0, 0, gh
);
1385 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1386 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1388 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1389 schedule_delayed_work(&gr
->gr_work
, time
);
1395 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1396 * @gh: the holder structure
1400 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1403 gfs2_holder_uninit(gh
);
1407 * gfs2_glock_nq_num - acquire a glock based on lock number
1408 * @sdp: the filesystem
1409 * @number: the lock number
1410 * @glops: the glock operations for the type of glock
1411 * @state: the state to acquire the glock in
1412 * @flags: modifier flags for the aquisition
1413 * @gh: the struct gfs2_holder
1418 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1419 struct gfs2_glock_operations
*glops
, unsigned int state
,
1420 int flags
, struct gfs2_holder
*gh
)
1422 struct gfs2_glock
*gl
;
1425 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1427 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1435 * glock_compare - Compare two struct gfs2_glock structures for sorting
1436 * @arg_a: the first structure
1437 * @arg_b: the second structure
1441 static int glock_compare(const void *arg_a
, const void *arg_b
)
1443 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1444 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1445 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1446 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1449 if (a
->ln_number
> b
->ln_number
)
1451 else if (a
->ln_number
< b
->ln_number
)
1454 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1455 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1457 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1458 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1466 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1467 * @num_gh: the number of structures
1468 * @ghs: an array of struct gfs2_holder structures
1470 * Returns: 0 on success (all glocks acquired),
1471 * errno on failure (no glocks acquired)
1474 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1475 struct gfs2_holder
**p
)
1480 for (x
= 0; x
< num_gh
; x
++)
1483 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1485 for (x
= 0; x
< num_gh
; x
++) {
1486 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1488 error
= gfs2_glock_nq(p
[x
]);
1491 gfs2_glock_dq(p
[x
]);
1500 * gfs2_glock_nq_m - acquire multiple glocks
1501 * @num_gh: the number of structures
1502 * @ghs: an array of struct gfs2_holder structures
1504 * Figure out how big an impact this function has. Either:
1505 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1506 * 2) Forget async stuff and just call nq_m_sync()
1507 * 3) Leave it like it is
1509 * Returns: 0 on success (all glocks acquired),
1510 * errno on failure (no glocks acquired)
1513 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1517 int borked
= 0, serious
= 0;
1524 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1525 return gfs2_glock_nq(ghs
);
1528 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1532 for (x
= 0; x
< num_gh
; x
++) {
1533 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1534 error
= gfs2_glock_nq(&ghs
[x
]);
1543 for (x
= 0; x
< num_gh
; x
++) {
1544 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1547 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1557 for (x
= 0; x
< num_gh
; x
++)
1559 gfs2_glock_dq(&ghs
[x
]);
1564 for (x
= 0; x
< num_gh
; x
++)
1565 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1567 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1576 * gfs2_glock_dq_m - release multiple glocks
1577 * @num_gh: the number of structures
1578 * @ghs: an array of struct gfs2_holder structures
1582 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1586 for (x
= 0; x
< num_gh
; x
++)
1587 gfs2_glock_dq(&ghs
[x
]);
1591 * gfs2_glock_dq_uninit_m - release multiple glocks
1592 * @num_gh: the number of structures
1593 * @ghs: an array of struct gfs2_holder structures
1597 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1601 for (x
= 0; x
< num_gh
; x
++)
1602 gfs2_glock_dq_uninit(&ghs
[x
]);
1606 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1607 * @sdp: the filesystem
1608 * @number: the lock number
1609 * @glops: the glock operations for the type of glock
1610 * @state: the state to acquire the glock in
1611 * @flags: modifier flags for the aquisition
1616 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1617 struct gfs2_glock_operations
*glops
,
1618 unsigned int state
, int flags
)
1620 struct gfs2_glock
*gl
;
1623 if (atomic_read(&sdp
->sd_reclaim_count
) <
1624 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1625 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1627 gfs2_glock_prefetch(gl
, state
, flags
);
1634 * gfs2_lvb_hold - attach a LVB from a glock
1635 * @gl: The glock in question
1639 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1643 gfs2_glmutex_lock(gl
);
1645 if (!atomic_read(&gl
->gl_lvb_count
)) {
1646 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1648 gfs2_glmutex_unlock(gl
);
1651 gfs2_glock_hold(gl
);
1653 atomic_inc(&gl
->gl_lvb_count
);
1655 gfs2_glmutex_unlock(gl
);
1661 * gfs2_lvb_unhold - detach a LVB from a glock
1662 * @gl: The glock in question
1666 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1668 gfs2_glock_hold(gl
);
1669 gfs2_glmutex_lock(gl
);
1671 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1672 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1673 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1678 gfs2_glmutex_unlock(gl
);
1683 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1685 gfs2_glmutex_lock(gl
);
1687 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1688 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1689 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1691 gfs2_glmutex_unlock(gl
);
1695 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1698 struct gfs2_glock
*gl
;
1700 gl
= gfs2_glock_find(sdp
, name
);
1704 if (gl
->gl_ops
->go_callback
)
1705 gl
->gl_ops
->go_callback(gl
, state
);
1706 handle_callback(gl
, state
);
1708 spin_lock(&gl
->gl_spin
);
1710 spin_unlock(&gl
->gl_spin
);
1716 * gfs2_glock_cb - Callback used by locking module
1717 * @fsdata: Pointer to the superblock
1718 * @type: Type of callback
1719 * @data: Type dependent data pointer
1721 * Called by the locking module when it wants to tell us something.
1722 * Either we need to drop a lock, one of our ASYNC requests completed, or
1723 * a journal from another client needs to be recovered.
1726 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1728 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1732 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1736 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1740 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1744 struct lm_async_cb
*async
= data
;
1745 struct gfs2_glock
*gl
;
1747 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1748 if (gfs2_assert_warn(sdp
, gl
))
1750 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1751 gl
->gl_req_bh(gl
, async
->lc_ret
);
1756 case LM_CB_NEED_RECOVERY
:
1757 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1758 if (sdp
->sd_recoverd_process
)
1759 wake_up_process(sdp
->sd_recoverd_process
);
1762 case LM_CB_DROPLOCKS
:
1763 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1764 gfs2_quota_scan(sdp
);
1768 gfs2_assert_warn(sdp
, 0);
1774 * gfs2_try_toss_inode - try to remove a particular inode struct from cache
1775 * sdp: the filesystem
1776 * inum: the inode number
1780 void gfs2_try_toss_inode(struct gfs2_sbd
*sdp
, struct gfs2_inum
*inum
)
1782 struct gfs2_glock
*gl
;
1783 struct gfs2_inode
*ip
;
1786 error
= gfs2_glock_get(sdp
, inum
->no_addr
, &gfs2_inode_glops
,
1791 if (!gfs2_glmutex_trylock(gl
))
1798 if (atomic_read(&ip
->i_count
))
1801 gfs2_inode_destroy(ip
, 1);
1804 gfs2_glmutex_unlock(gl
);
1811 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1812 * iopen glock from memory
1813 * @io_gl: the iopen glock
1814 * @state: the state into which the glock should be put
1818 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1820 struct gfs2_glock
*i_gl
;
1822 if (state
!= LM_ST_UNLOCKED
)
1825 spin_lock(&io_gl
->gl_spin
);
1826 i_gl
= io_gl
->gl_object
;
1828 gfs2_glock_hold(i_gl
);
1829 spin_unlock(&io_gl
->gl_spin
);
1831 spin_unlock(&io_gl
->gl_spin
);
1835 if (gfs2_glmutex_trylock(i_gl
)) {
1836 struct gfs2_inode
*ip
= i_gl
->gl_object
;
1838 gfs2_try_toss_vnode(ip
);
1839 gfs2_glmutex_unlock(i_gl
);
1840 gfs2_glock_schedule_for_reclaim(i_gl
);
1843 gfs2_glmutex_unlock(i_gl
);
1847 gfs2_glock_put(i_gl
);
1851 * demote_ok - Check to see if it's ok to unlock a glock
1854 * Returns: 1 if it's ok
1857 static int demote_ok(struct gfs2_glock
*gl
)
1859 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1860 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1863 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1865 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
1866 demote
= time_after_eq(jiffies
,
1868 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
1869 else if (glops
->go_demote_ok
)
1870 demote
= glops
->go_demote_ok(gl
);
1876 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1881 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1883 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1885 spin_lock(&sdp
->sd_reclaim_lock
);
1886 if (list_empty(&gl
->gl_reclaim
)) {
1887 gfs2_glock_hold(gl
);
1888 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1889 atomic_inc(&sdp
->sd_reclaim_count
);
1891 spin_unlock(&sdp
->sd_reclaim_lock
);
1893 wake_up(&sdp
->sd_reclaim_wq
);
1897 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1898 * @sdp: the filesystem
1900 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1901 * different glock and we notice that there are a lot of glocks in the
1906 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1908 struct gfs2_glock
*gl
;
1910 spin_lock(&sdp
->sd_reclaim_lock
);
1911 if (list_empty(&sdp
->sd_reclaim_list
)) {
1912 spin_unlock(&sdp
->sd_reclaim_lock
);
1915 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1916 struct gfs2_glock
, gl_reclaim
);
1917 list_del_init(&gl
->gl_reclaim
);
1918 spin_unlock(&sdp
->sd_reclaim_lock
);
1920 atomic_dec(&sdp
->sd_reclaim_count
);
1921 atomic_inc(&sdp
->sd_reclaimed
);
1923 if (gfs2_glmutex_trylock(gl
)) {
1924 if (gl
->gl_ops
== &gfs2_inode_glops
) {
1925 struct gfs2_inode
*ip
= gl
->gl_object
;
1926 if (ip
&& !atomic_read(&ip
->i_count
))
1927 gfs2_inode_destroy(ip
, 1);
1929 if (queue_empty(gl
, &gl
->gl_holders
) &&
1930 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1932 handle_callback(gl
, LM_ST_UNLOCKED
);
1933 gfs2_glmutex_unlock(gl
);
1940 * examine_bucket - Call a function for glock in a hash bucket
1941 * @examiner: the function
1942 * @sdp: the filesystem
1943 * @bucket: the bucket
1945 * Returns: 1 if the bucket has entries
1948 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1949 struct gfs2_gl_hash_bucket
*bucket
)
1951 struct glock_plug plug
;
1952 struct list_head
*tmp
;
1953 struct gfs2_glock
*gl
;
1956 /* Add "plug" to end of bucket list, work back up list from there */
1957 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
1958 set_bit(GLF_PLUG
, &plug
.gl_flags
);
1960 write_lock(&bucket
->hb_lock
);
1961 list_add(&plug
.gl_list
, &bucket
->hb_list
);
1962 write_unlock(&bucket
->hb_lock
);
1965 write_lock(&bucket
->hb_lock
);
1968 tmp
= plug
.gl_list
.next
;
1970 if (tmp
== &bucket
->hb_list
) {
1971 list_del(&plug
.gl_list
);
1972 entries
= !list_empty(&bucket
->hb_list
);
1973 write_unlock(&bucket
->hb_lock
);
1976 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
1978 /* Move plug up list */
1979 list_move(&plug
.gl_list
, &gl
->gl_list
);
1981 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
1984 /* examiner() must glock_put() */
1985 gfs2_glock_hold(gl
);
1990 write_unlock(&bucket
->hb_lock
);
1997 * scan_glock - look at a glock and see if we can reclaim it
1998 * @gl: the glock to look at
2002 static void scan_glock(struct gfs2_glock
*gl
)
2004 if (gfs2_glmutex_trylock(gl
)) {
2005 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2006 struct gfs2_inode
*ip
= gl
->gl_object
;
2007 if (ip
&& !atomic_read(&ip
->i_count
))
2010 if (queue_empty(gl
, &gl
->gl_holders
) &&
2011 gl
->gl_state
!= LM_ST_UNLOCKED
&&
2015 gfs2_glmutex_unlock(gl
);
2023 gfs2_glmutex_unlock(gl
);
2024 gfs2_glock_schedule_for_reclaim(gl
);
2029 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
2030 * @sdp: the filesystem
2034 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
2038 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2039 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
2045 * clear_glock - look at a glock and see if we can free it from glock cache
2046 * @gl: the glock to look at
2050 static void clear_glock(struct gfs2_glock
*gl
)
2052 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2055 spin_lock(&sdp
->sd_reclaim_lock
);
2056 if (!list_empty(&gl
->gl_reclaim
)) {
2057 list_del_init(&gl
->gl_reclaim
);
2058 atomic_dec(&sdp
->sd_reclaim_count
);
2059 spin_unlock(&sdp
->sd_reclaim_lock
);
2060 released
= gfs2_glock_put(gl
);
2061 gfs2_assert(sdp
, !released
);
2063 spin_unlock(&sdp
->sd_reclaim_lock
);
2066 if (gfs2_glmutex_trylock(gl
)) {
2067 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2068 struct gfs2_inode
*ip
= gl
->gl_object
;
2069 if (ip
&& !atomic_read(&ip
->i_count
))
2070 gfs2_inode_destroy(ip
, 1);
2072 if (queue_empty(gl
, &gl
->gl_holders
) &&
2073 gl
->gl_state
!= LM_ST_UNLOCKED
)
2074 handle_callback(gl
, LM_ST_UNLOCKED
);
2076 gfs2_glmutex_unlock(gl
);
2083 * gfs2_gl_hash_clear - Empty out the glock hash table
2084 * @sdp: the filesystem
2085 * @wait: wait until it's all gone
2087 * Called when unmounting the filesystem, or when inter-node lock manager
2088 * requests DROPLOCKS because it is running out of capacity.
2091 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2102 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2103 if (examine_bucket(clear_glock
, sdp
,
2104 &sdp
->sd_gl_hash
[x
]))
2110 if (time_after_eq(jiffies
,
2111 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2112 fs_warn(sdp
, "Unmount seems to be stalled. "
2113 "Dumping lock state...\n");
2114 gfs2_dump_lockstate(sdp
);
2118 /* invalidate_inodes() requires that the sb inodes list
2119 not change, but an async completion callback for an
2120 unlock can occur which does glock_put() which
2121 can call iput() which will change the sb inodes list.
2122 invalidate_inodes_mutex prevents glock_put()'s during
2123 an invalidate_inodes() */
2125 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
2126 invalidate_inodes(sdp
->sd_vfs
);
2127 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
2133 * Diagnostic routines to help debug distributed deadlock
2137 * dump_holder - print information about a glock holder
2138 * @str: a string naming the type of holder
2139 * @gh: the glock holder
2141 * Returns: 0 on success, -ENOBUFS when we run out of space
2144 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2147 int error
= -ENOBUFS
;
2149 printk(KERN_INFO
" %s\n", str
);
2150 printk(KERN_INFO
" owner = %ld\n",
2151 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2152 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2153 printk(KERN_INFO
" gh_flags =");
2154 for (x
= 0; x
< 32; x
++)
2155 if (gh
->gh_flags
& (1 << x
))
2158 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2159 printk(KERN_INFO
" gh_iflags =");
2160 for (x
= 0; x
< 32; x
++)
2161 if (test_bit(x
, &gh
->gh_iflags
))
2164 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2172 * dump_inode - print information about an inode
2175 * Returns: 0 on success, -ENOBUFS when we run out of space
2178 static int dump_inode(struct gfs2_inode
*ip
)
2181 int error
= -ENOBUFS
;
2183 printk(KERN_INFO
" Inode:\n");
2184 printk(KERN_INFO
" num = %llu %llu\n",
2185 ip
->i_num
.no_formal_ino
, ip
->i_num
.no_addr
);
2186 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2187 printk(KERN_INFO
" i_count = %d\n", atomic_read(&ip
->i_count
));
2188 printk(KERN_INFO
" i_flags =");
2189 for (x
= 0; x
< 32; x
++)
2190 if (test_bit(x
, &ip
->i_flags
))
2193 printk(KERN_INFO
" vnode = %s\n", (ip
->i_vnode
) ? "yes" : "no");
2201 * dump_glock - print information about a glock
2203 * @count: where we are in the buffer
2205 * Returns: 0 on success, -ENOBUFS when we run out of space
2208 static int dump_glock(struct gfs2_glock
*gl
)
2210 struct gfs2_holder
*gh
;
2212 int error
= -ENOBUFS
;
2214 spin_lock(&gl
->gl_spin
);
2216 printk(KERN_INFO
"Glock (%u, %llu)\n",
2217 gl
->gl_name
.ln_type
,
2218 gl
->gl_name
.ln_number
);
2219 printk(KERN_INFO
" gl_flags =");
2220 for (x
= 0; x
< 32; x
++)
2221 if (test_bit(x
, &gl
->gl_flags
))
2224 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2225 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2226 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2227 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2228 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2229 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2230 printk(KERN_INFO
" le = %s\n",
2231 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2232 printk(KERN_INFO
" reclaim = %s\n",
2233 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2235 printk(KERN_INFO
" aspace = %lu\n",
2236 gl
->gl_aspace
->i_mapping
->nrpages
);
2238 printk(KERN_INFO
" aspace = no\n");
2239 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2240 if (gl
->gl_req_gh
) {
2241 error
= dump_holder("Request", gl
->gl_req_gh
);
2245 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2246 error
= dump_holder("Holder", gh
);
2250 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2251 error
= dump_holder("Waiter1", gh
);
2255 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2256 error
= dump_holder("Waiter2", gh
);
2260 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2261 error
= dump_holder("Waiter3", gh
);
2265 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2266 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2267 list_empty(&gl
->gl_holders
)) {
2268 error
= dump_inode(gl
->gl_object
);
2273 printk(KERN_INFO
" Inode: busy\n");
2280 spin_unlock(&gl
->gl_spin
);
2286 * gfs2_dump_lockstate - print out the current lockstate
2287 * @sdp: the filesystem
2288 * @ub: the buffer to copy the information into
2290 * If @ub is NULL, dump the lockstate to the console.
2294 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2296 struct gfs2_gl_hash_bucket
*bucket
;
2297 struct gfs2_glock
*gl
;
2301 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2302 bucket
= &sdp
->sd_gl_hash
[x
];
2304 read_lock(&bucket
->hb_lock
);
2306 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2307 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2310 error
= dump_glock(gl
);
2315 read_unlock(&bucket
->hb_lock
);