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
);
51 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
52 * @actual: the current state of the lock
53 * @requested: the lock state that was requested by the caller
54 * @flags: the modifier flags passed in by the caller
56 * Returns: 1 if the locks are compatible, 0 otherwise
59 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
62 if (actual
== requested
)
68 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
71 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
78 * gl_hash() - Turn glock number into hash bucket number
79 * @lock: The glock number
81 * Returns: The number of the corresponding hash bucket
84 static unsigned int gl_hash(struct lm_lockname
*name
)
88 h
= jhash(&name
->ln_number
, sizeof(uint64_t), 0);
89 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
90 h
&= GFS2_GL_HASH_MASK
;
96 * glock_free() - Perform a few checks and then release struct gfs2_glock
97 * @gl: The glock to release
99 * Also calls lock module to release its internal structure for this glock.
103 static void glock_free(struct gfs2_glock
*gl
)
105 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
106 struct inode
*aspace
= gl
->gl_aspace
;
108 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
111 gfs2_aspace_put(aspace
);
113 kmem_cache_free(gfs2_glock_cachep
, gl
);
117 * gfs2_glock_hold() - increment reference count on glock
118 * @gl: The glock to hold
122 void gfs2_glock_hold(struct gfs2_glock
*gl
)
124 kref_get(&gl
->gl_ref
);
127 /* All work is done after the return from kref_put() so we
128 can release the write_lock before the free. */
130 static void kill_glock(struct kref
*kref
)
132 struct gfs2_glock
*gl
= container_of(kref
, struct gfs2_glock
, gl_ref
);
133 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
135 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
136 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
137 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
138 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
139 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
140 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
144 * gfs2_glock_put() - Decrement reference count on glock
145 * @gl: The glock to put
149 int gfs2_glock_put(struct gfs2_glock
*gl
)
151 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
152 struct gfs2_gl_hash_bucket
*bucket
= gl
->gl_bucket
;
155 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
157 write_lock(&bucket
->hb_lock
);
158 if (kref_put(&gl
->gl_ref
, kill_glock
)) {
159 list_del_init(&gl
->gl_list
);
160 write_unlock(&bucket
->hb_lock
);
165 write_unlock(&bucket
->hb_lock
);
167 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
172 * queue_empty - check to see if a glock's queue is empty
174 * @head: the head of the queue to check
176 * This function protects the list in the event that a process already
177 * has a holder on the list and is adding a second holder for itself.
178 * The glmutex lock is what generally prevents processes from working
179 * on the same glock at once, but the special case of adding a second
180 * holder for yourself ("recursive" locking) doesn't involve locking
181 * glmutex, making the spin lock necessary.
183 * Returns: 1 if the queue is empty
186 static inline int queue_empty(struct gfs2_glock
*gl
, struct list_head
*head
)
189 spin_lock(&gl
->gl_spin
);
190 empty
= list_empty(head
);
191 spin_unlock(&gl
->gl_spin
);
196 * search_bucket() - Find struct gfs2_glock by lock number
197 * @bucket: the bucket to search
198 * @name: The lock name
200 * Returns: NULL, or the struct gfs2_glock with the requested number
203 static struct gfs2_glock
*search_bucket(struct gfs2_gl_hash_bucket
*bucket
,
204 struct lm_lockname
*name
)
206 struct gfs2_glock
*gl
;
208 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
209 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
211 if (!lm_name_equal(&gl
->gl_name
, name
))
214 kref_get(&gl
->gl_ref
);
223 * gfs2_glock_find() - Find glock by lock number
224 * @sdp: The GFS2 superblock
225 * @name: The lock name
227 * Returns: NULL, or the struct gfs2_glock with the requested number
230 struct gfs2_glock
*gfs2_glock_find(struct gfs2_sbd
*sdp
,
231 struct lm_lockname
*name
)
233 struct gfs2_gl_hash_bucket
*bucket
= &sdp
->sd_gl_hash
[gl_hash(name
)];
234 struct gfs2_glock
*gl
;
236 read_lock(&bucket
->hb_lock
);
237 gl
= search_bucket(bucket
, name
);
238 read_unlock(&bucket
->hb_lock
);
244 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
245 * @sdp: The GFS2 superblock
246 * @number: the lock number
247 * @glops: The glock_operations to use
248 * @create: If 0, don't create the glock if it doesn't exist
249 * @glp: the glock is returned here
251 * This does not lock a glock, just finds/creates structures for one.
256 int gfs2_glock_get(struct gfs2_sbd
*sdp
, uint64_t number
,
257 struct gfs2_glock_operations
*glops
, int create
,
258 struct gfs2_glock
**glp
)
260 struct lm_lockname name
;
261 struct gfs2_glock
*gl
, *tmp
;
262 struct gfs2_gl_hash_bucket
*bucket
;
265 name
.ln_number
= number
;
266 name
.ln_type
= glops
->go_type
;
267 bucket
= &sdp
->sd_gl_hash
[gl_hash(&name
)];
269 read_lock(&bucket
->hb_lock
);
270 gl
= search_bucket(bucket
, &name
);
271 read_unlock(&bucket
->hb_lock
);
278 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
282 memset(gl
, 0, sizeof(struct gfs2_glock
));
284 INIT_LIST_HEAD(&gl
->gl_list
);
286 kref_init(&gl
->gl_ref
);
288 spin_lock_init(&gl
->gl_spin
);
290 gl
->gl_state
= LM_ST_UNLOCKED
;
291 INIT_LIST_HEAD(&gl
->gl_holders
);
292 INIT_LIST_HEAD(&gl
->gl_waiters1
);
293 INIT_LIST_HEAD(&gl
->gl_waiters2
);
294 INIT_LIST_HEAD(&gl
->gl_waiters3
);
298 gl
->gl_bucket
= bucket
;
299 INIT_LIST_HEAD(&gl
->gl_reclaim
);
303 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
304 INIT_LIST_HEAD(&gl
->gl_ail_list
);
306 /* If this glock protects actual on-disk data or metadata blocks,
307 create a VFS inode to manage the pages/buffers holding them. */
308 if (glops
== &gfs2_inode_glops
||
309 glops
== &gfs2_rgrp_glops
||
310 glops
== &gfs2_meta_glops
) {
311 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
312 if (!gl
->gl_aspace
) {
318 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
322 write_lock(&bucket
->hb_lock
);
323 tmp
= search_bucket(bucket
, &name
);
325 write_unlock(&bucket
->hb_lock
);
329 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
330 write_unlock(&bucket
->hb_lock
);
339 gfs2_aspace_put(gl
->gl_aspace
);
342 kmem_cache_free(gfs2_glock_cachep
, gl
);
348 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
350 * @state: the state we're requesting
351 * @flags: the modifier flags
352 * @gh: the holder structure
356 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, int flags
,
357 struct gfs2_holder
*gh
)
359 INIT_LIST_HEAD(&gh
->gh_list
);
361 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
362 gh
->gh_owner
= (flags
& GL_NEVER_RECURSE
) ? NULL
: current
;
363 gh
->gh_state
= state
;
364 gh
->gh_flags
= flags
;
367 init_completion(&gh
->gh_wait
);
369 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
370 gh
->gh_flags
|= GL_LOCAL_EXCL
;
376 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
377 * @state: the state we're requesting
378 * @flags: the modifier flags
379 * @gh: the holder structure
381 * Don't mess with the glock.
385 void gfs2_holder_reinit(unsigned int state
, int flags
, struct gfs2_holder
*gh
)
387 gh
->gh_state
= state
;
388 gh
->gh_flags
= flags
;
389 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
390 gh
->gh_flags
|= GL_LOCAL_EXCL
;
392 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
393 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
397 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
398 * @gh: the holder structure
402 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
404 gfs2_glock_put(gh
->gh_gl
);
410 * gfs2_holder_get - get a struct gfs2_holder structure
412 * @state: the state we're requesting
413 * @flags: the modifier flags
414 * @gfp_flags: __GFP_NOFAIL
416 * Figure out how big an impact this function has. Either:
417 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
418 * 2) Leave it like it is
420 * Returns: the holder structure, NULL on ENOMEM
423 struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
, unsigned int state
,
424 int flags
, gfp_t gfp_flags
)
426 struct gfs2_holder
*gh
;
428 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
432 gfs2_holder_init(gl
, state
, flags
, gh
);
433 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
434 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
439 * gfs2_holder_put - get rid of a struct gfs2_holder structure
440 * @gh: the holder structure
444 void gfs2_holder_put(struct gfs2_holder
*gh
)
446 gfs2_holder_uninit(gh
);
451 * handle_recurse - put other holder structures (marked recursive)
452 * into the holders list
453 * @gh: the holder structure
457 static void handle_recurse(struct gfs2_holder
*gh
)
459 struct gfs2_glock
*gl
= gh
->gh_gl
;
460 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
461 struct gfs2_holder
*tmp_gh
, *safe
;
464 printk(KERN_INFO
"recursion %016llx, %u\n", gl
->gl_name
.ln_number
,
465 gl
->gl_name
.ln_type
);
467 if (gfs2_assert_warn(sdp
, gh
->gh_owner
))
470 list_for_each_entry_safe(tmp_gh
, safe
, &gl
->gl_waiters3
, gh_list
) {
471 if (tmp_gh
->gh_owner
!= gh
->gh_owner
)
474 gfs2_assert_warn(sdp
,
475 test_bit(HIF_RECURSE
, &tmp_gh
->gh_iflags
));
477 list_move_tail(&tmp_gh
->gh_list
, &gl
->gl_holders
);
478 tmp_gh
->gh_error
= 0;
479 set_bit(HIF_HOLDER
, &tmp_gh
->gh_iflags
);
481 complete(&tmp_gh
->gh_wait
);
486 gfs2_assert_warn(sdp
, found
);
490 * do_unrecurse - a recursive holder was just dropped of the waiters3 list
493 * If there is only one other recursive holder, clear its HIF_RECURSE bit.
494 * If there is more than one, leave them alone.
498 static void do_unrecurse(struct gfs2_holder
*gh
)
500 struct gfs2_glock
*gl
= gh
->gh_gl
;
501 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
502 struct gfs2_holder
*tmp_gh
, *last_gh
= NULL
;
505 if (gfs2_assert_warn(sdp
, gh
->gh_owner
))
508 list_for_each_entry(tmp_gh
, &gl
->gl_waiters3
, gh_list
) {
509 if (tmp_gh
->gh_owner
!= gh
->gh_owner
)
512 gfs2_assert_warn(sdp
,
513 test_bit(HIF_RECURSE
, &tmp_gh
->gh_iflags
));
522 if (!gfs2_assert_warn(sdp
, found
))
523 clear_bit(HIF_RECURSE
, &last_gh
->gh_iflags
);
527 * rq_mutex - process a mutex request in the queue
528 * @gh: the glock holder
530 * Returns: 1 if the queue is blocked
533 static int rq_mutex(struct gfs2_holder
*gh
)
535 struct gfs2_glock
*gl
= gh
->gh_gl
;
537 list_del_init(&gh
->gh_list
);
538 /* gh->gh_error never examined. */
539 set_bit(GLF_LOCK
, &gl
->gl_flags
);
540 complete(&gh
->gh_wait
);
546 * rq_promote - process a promote request in the queue
547 * @gh: the glock holder
549 * Acquire a new inter-node lock, or change a lock state to more restrictive.
551 * Returns: 1 if the queue is blocked
554 static int rq_promote(struct gfs2_holder
*gh
)
556 struct gfs2_glock
*gl
= gh
->gh_gl
;
557 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
558 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
561 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
562 if (list_empty(&gl
->gl_holders
)) {
564 set_bit(GLF_LOCK
, &gl
->gl_flags
);
565 spin_unlock(&gl
->gl_spin
);
567 if (atomic_read(&sdp
->sd_reclaim_count
) >
568 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
569 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
570 gfs2_reclaim_glock(sdp
);
571 gfs2_reclaim_glock(sdp
);
574 glops
->go_xmote_th(gl
, gh
->gh_state
,
577 spin_lock(&gl
->gl_spin
);
582 if (list_empty(&gl
->gl_holders
)) {
583 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
584 set_bit(GLF_LOCK
, &gl
->gl_flags
);
587 struct gfs2_holder
*next_gh
;
588 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
590 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
592 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
594 recurse
= test_bit(HIF_RECURSE
, &gh
->gh_iflags
);
597 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
599 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
604 complete(&gh
->gh_wait
);
610 * rq_demote - process a demote request in the queue
611 * @gh: the glock holder
613 * Returns: 1 if the queue is blocked
616 static int rq_demote(struct gfs2_holder
*gh
)
618 struct gfs2_glock
*gl
= gh
->gh_gl
;
619 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
621 if (!list_empty(&gl
->gl_holders
))
624 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
625 list_del_init(&gh
->gh_list
);
627 spin_unlock(&gl
->gl_spin
);
628 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
631 complete(&gh
->gh_wait
);
632 spin_lock(&gl
->gl_spin
);
635 set_bit(GLF_LOCK
, &gl
->gl_flags
);
636 spin_unlock(&gl
->gl_spin
);
638 if (gh
->gh_state
== LM_ST_UNLOCKED
||
639 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
640 glops
->go_drop_th(gl
);
642 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
644 spin_lock(&gl
->gl_spin
);
651 * rq_greedy - process a queued request to drop greedy status
652 * @gh: the glock holder
654 * Returns: 1 if the queue is blocked
657 static int rq_greedy(struct gfs2_holder
*gh
)
659 struct gfs2_glock
*gl
= gh
->gh_gl
;
661 list_del_init(&gh
->gh_list
);
662 /* gh->gh_error never examined. */
663 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
664 spin_unlock(&gl
->gl_spin
);
666 gfs2_holder_uninit(gh
);
667 kfree(container_of(gh
, struct greedy
, gr_gh
));
669 spin_lock(&gl
->gl_spin
);
675 * run_queue - process holder structures on a glock
680 static void run_queue(struct gfs2_glock
*gl
)
682 struct gfs2_holder
*gh
;
686 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
689 if (!list_empty(&gl
->gl_waiters1
)) {
690 gh
= list_entry(gl
->gl_waiters1
.next
,
691 struct gfs2_holder
, gh_list
);
693 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
694 blocked
= rq_mutex(gh
);
696 gfs2_assert_warn(gl
->gl_sbd
, 0);
698 } else if (!list_empty(&gl
->gl_waiters2
) &&
699 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
700 gh
= list_entry(gl
->gl_waiters2
.next
,
701 struct gfs2_holder
, gh_list
);
703 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
704 blocked
= rq_demote(gh
);
705 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
706 blocked
= rq_greedy(gh
);
708 gfs2_assert_warn(gl
->gl_sbd
, 0);
710 } else if (!list_empty(&gl
->gl_waiters3
)) {
711 gh
= list_entry(gl
->gl_waiters3
.next
,
712 struct gfs2_holder
, gh_list
);
714 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
715 blocked
= rq_promote(gh
);
717 gfs2_assert_warn(gl
->gl_sbd
, 0);
728 * gfs2_glmutex_lock - acquire a local lock on a glock
731 * Gives caller exclusive access to manipulate a glock structure.
734 void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
736 struct gfs2_holder gh
;
738 gfs2_holder_init(gl
, 0, 0, &gh
);
739 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
741 spin_lock(&gl
->gl_spin
);
742 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
743 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
745 complete(&gh
.gh_wait
);
746 spin_unlock(&gl
->gl_spin
);
748 wait_for_completion(&gh
.gh_wait
);
749 gfs2_holder_uninit(&gh
);
753 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
756 * Returns: 1 if the glock is acquired
759 int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
763 spin_lock(&gl
->gl_spin
);
764 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
766 spin_unlock(&gl
->gl_spin
);
772 * gfs2_glmutex_unlock - release a local lock on a glock
777 void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
779 spin_lock(&gl
->gl_spin
);
780 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
782 spin_unlock(&gl
->gl_spin
);
786 * handle_callback - add a demote request to a lock's queue
788 * @state: the state the caller wants us to change to
792 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
794 struct gfs2_holder
*gh
, *new_gh
= NULL
;
797 spin_lock(&gl
->gl_spin
);
799 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
800 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
801 gl
->gl_req_gh
!= gh
) {
802 if (gh
->gh_state
!= state
)
803 gh
->gh_state
= LM_ST_UNLOCKED
;
809 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
812 spin_unlock(&gl
->gl_spin
);
814 new_gh
= gfs2_holder_get(gl
, state
,
815 LM_FLAG_TRY
| GL_NEVER_RECURSE
,
816 GFP_KERNEL
| __GFP_NOFAIL
),
817 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
818 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
824 spin_unlock(&gl
->gl_spin
);
827 gfs2_holder_put(new_gh
);
831 * state_change - record that the glock is now in a different state
833 * @new_state the new state
837 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
841 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
842 held2
= (new_state
!= LM_ST_UNLOCKED
);
844 if (held1
!= held2
) {
851 gl
->gl_state
= new_state
;
855 * xmote_bh - Called after the lock module is done acquiring a lock
856 * @gl: The glock in question
857 * @ret: the int returned from the lock module
861 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
863 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
864 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
865 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
866 int prev_state
= gl
->gl_state
;
869 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
870 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
871 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
873 state_change(gl
, ret
& LM_OUT_ST_MASK
);
875 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
877 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
878 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
879 /* We might not want to do this here.
880 Look at moving to the inode glops. */
882 glops
->go_inval(gl
, DIO_DATA
);
885 /* Deal with each possible exit condition */
888 gl
->gl_stamp
= jiffies
;
890 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
891 spin_lock(&gl
->gl_spin
);
892 list_del_init(&gh
->gh_list
);
894 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
896 spin_unlock(&gl
->gl_spin
);
898 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
899 spin_lock(&gl
->gl_spin
);
900 list_del_init(&gh
->gh_list
);
901 if (gl
->gl_state
== gh
->gh_state
||
902 gl
->gl_state
== LM_ST_UNLOCKED
)
905 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
906 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
907 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
908 gh
->gh_error
= GLR_TRYFAILED
;
910 spin_unlock(&gl
->gl_spin
);
912 if (ret
& LM_OUT_CANCELED
)
913 handle_callback(gl
, LM_ST_UNLOCKED
); /* Lame */
915 } else if (ret
& LM_OUT_CANCELED
) {
916 spin_lock(&gl
->gl_spin
);
917 list_del_init(&gh
->gh_list
);
918 gh
->gh_error
= GLR_CANCELED
;
919 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
921 spin_unlock(&gl
->gl_spin
);
923 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
924 spin_lock(&gl
->gl_spin
);
925 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
927 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
928 spin_unlock(&gl
->gl_spin
);
930 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
934 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
935 spin_lock(&gl
->gl_spin
);
936 list_del_init(&gh
->gh_list
);
937 gh
->gh_error
= GLR_TRYFAILED
;
938 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
940 spin_unlock(&gl
->gl_spin
);
943 if (gfs2_assert_withdraw(sdp
, 0) == -1)
944 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
947 if (glops
->go_xmote_bh
)
948 glops
->go_xmote_bh(gl
);
951 spin_lock(&gl
->gl_spin
);
952 gl
->gl_req_gh
= NULL
;
953 gl
->gl_req_bh
= NULL
;
954 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
956 spin_unlock(&gl
->gl_spin
);
962 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
965 complete(&gh
->gh_wait
);
970 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
971 * @gl: The glock in question
972 * @state: the requested state
973 * @flags: modifier flags to the lock call
977 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
979 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
980 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
981 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
982 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
984 unsigned int lck_ret
;
986 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
987 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
988 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
989 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
991 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
994 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
998 gl
->gl_req_bh
= xmote_bh
;
1000 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
,
1003 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
1006 if (lck_ret
& LM_OUT_ASYNC
)
1007 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
1009 xmote_bh(gl
, lck_ret
);
1013 * drop_bh - Called after a lock module unlock completes
1015 * @ret: the return status
1017 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
1018 * Doesn't drop the reference on the glock the top half took out
1022 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
1024 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1025 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1026 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
1028 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1030 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1031 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1032 gfs2_assert_warn(sdp
, !ret
);
1034 state_change(gl
, LM_ST_UNLOCKED
);
1036 if (glops
->go_inval
)
1037 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
1040 spin_lock(&gl
->gl_spin
);
1041 list_del_init(&gh
->gh_list
);
1043 spin_unlock(&gl
->gl_spin
);
1046 if (glops
->go_drop_bh
)
1047 glops
->go_drop_bh(gl
);
1049 spin_lock(&gl
->gl_spin
);
1050 gl
->gl_req_gh
= NULL
;
1051 gl
->gl_req_bh
= NULL
;
1052 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1054 spin_unlock(&gl
->gl_spin
);
1059 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
1060 gfs2_holder_put(gh
);
1062 complete(&gh
->gh_wait
);
1067 * gfs2_glock_drop_th - call into the lock module to unlock a lock
1072 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
1074 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1075 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1078 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1079 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1080 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1082 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1085 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1088 gfs2_glock_hold(gl
);
1089 gl
->gl_req_bh
= drop_bh
;
1091 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1093 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1099 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1103 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1104 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1106 * Don't cancel GL_NOCANCEL requests.
1109 static void do_cancels(struct gfs2_holder
*gh
)
1111 struct gfs2_glock
*gl
= gh
->gh_gl
;
1113 spin_lock(&gl
->gl_spin
);
1115 while (gl
->gl_req_gh
!= gh
&&
1116 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1117 !list_empty(&gh
->gh_list
)) {
1118 if (gl
->gl_req_bh
&&
1120 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1121 spin_unlock(&gl
->gl_spin
);
1122 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1124 spin_lock(&gl
->gl_spin
);
1126 spin_unlock(&gl
->gl_spin
);
1128 spin_lock(&gl
->gl_spin
);
1132 spin_unlock(&gl
->gl_spin
);
1136 * glock_wait_internal - wait on a glock acquisition
1137 * @gh: the glock holder
1139 * Returns: 0 on success
1142 static int glock_wait_internal(struct gfs2_holder
*gh
)
1144 struct gfs2_glock
*gl
= gh
->gh_gl
;
1145 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1146 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1148 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1151 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1152 spin_lock(&gl
->gl_spin
);
1153 if (gl
->gl_req_gh
!= gh
&&
1154 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1155 !list_empty(&gh
->gh_list
)) {
1156 list_del_init(&gh
->gh_list
);
1157 gh
->gh_error
= GLR_TRYFAILED
;
1158 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
1161 spin_unlock(&gl
->gl_spin
);
1162 return gh
->gh_error
;
1164 spin_unlock(&gl
->gl_spin
);
1167 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1170 wait_for_completion(&gh
->gh_wait
);
1173 return gh
->gh_error
;
1175 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1176 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1180 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1181 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1183 if (glops
->go_lock
) {
1184 gh
->gh_error
= glops
->go_lock(gh
);
1186 spin_lock(&gl
->gl_spin
);
1187 list_del_init(&gh
->gh_list
);
1188 if (test_and_clear_bit(HIF_RECURSE
,
1191 spin_unlock(&gl
->gl_spin
);
1195 spin_lock(&gl
->gl_spin
);
1196 gl
->gl_req_gh
= NULL
;
1197 gl
->gl_req_bh
= NULL
;
1198 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1199 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
1202 spin_unlock(&gl
->gl_spin
);
1205 return gh
->gh_error
;
1208 static inline struct gfs2_holder
*
1209 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1211 struct gfs2_holder
*gh
;
1213 list_for_each_entry(gh
, head
, gh_list
) {
1214 if (gh
->gh_owner
== owner
)
1224 * Make sure the new holder is compatible with the pre-existing one.
1228 static int recurse_check(struct gfs2_holder
*existing
, struct gfs2_holder
*new,
1231 struct gfs2_sbd
*sdp
= existing
->gh_gl
->gl_sbd
;
1233 if (gfs2_assert_warn(sdp
, (new->gh_flags
& LM_FLAG_ANY
) ||
1234 !(existing
->gh_flags
& LM_FLAG_ANY
)))
1237 if (gfs2_assert_warn(sdp
, (existing
->gh_flags
& GL_LOCAL_EXCL
) ||
1238 !(new->gh_flags
& GL_LOCAL_EXCL
)))
1241 if (gfs2_assert_warn(sdp
, relaxed_state_ok(state
, new->gh_state
,
1248 print_symbol(KERN_WARNING
"GFS2: Existing holder from %s\n",
1250 print_symbol(KERN_WARNING
"GFS2: New holder from %s\n", new->gh_ip
);
1251 set_bit(HIF_ABORTED
, &new->gh_iflags
);
1256 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1257 * @gh: the holder structure to add
1261 static void add_to_queue(struct gfs2_holder
*gh
)
1263 struct gfs2_glock
*gl
= gh
->gh_gl
;
1264 struct gfs2_holder
*existing
;
1269 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1271 if (recurse_check(existing
, gh
, gl
->gl_state
))
1274 list_add_tail(&gh
->gh_list
, &gl
->gl_holders
);
1275 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
1278 complete(&gh
->gh_wait
);
1283 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1285 if (recurse_check(existing
, gh
, existing
->gh_state
))
1288 set_bit(HIF_RECURSE
, &gh
->gh_iflags
);
1289 set_bit(HIF_RECURSE
, &existing
->gh_iflags
);
1291 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1297 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1298 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1300 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1304 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1305 * @gh: the holder structure
1307 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1309 * Returns: 0, GLR_TRYFAILED, or errno on failure
1312 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1314 struct gfs2_glock
*gl
= gh
->gh_gl
;
1315 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1319 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1320 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1324 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1326 spin_lock(&gl
->gl_spin
);
1329 spin_unlock(&gl
->gl_spin
);
1331 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1332 error
= glock_wait_internal(gh
);
1333 if (error
== GLR_CANCELED
) {
1339 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1345 * gfs2_glock_poll - poll to see if an async request has been completed
1348 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1351 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1353 struct gfs2_glock
*gl
= gh
->gh_gl
;
1356 spin_lock(&gl
->gl_spin
);
1358 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1360 else if (list_empty(&gh
->gh_list
)) {
1361 if (gh
->gh_error
== GLR_CANCELED
) {
1362 spin_unlock(&gl
->gl_spin
);
1364 if (gfs2_glock_nq(gh
))
1371 spin_unlock(&gl
->gl_spin
);
1377 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1378 * @gh: the holder structure
1380 * Returns: 0, GLR_TRYFAILED, or errno on failure
1383 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1387 error
= glock_wait_internal(gh
);
1388 if (error
== GLR_CANCELED
) {
1390 gh
->gh_flags
&= ~GL_ASYNC
;
1391 error
= gfs2_glock_nq(gh
);
1398 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1399 * @gh: the glock holder
1403 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1405 struct gfs2_glock
*gl
= gh
->gh_gl
;
1406 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1408 if (gh
->gh_flags
& GL_SYNC
)
1409 set_bit(GLF_SYNC
, &gl
->gl_flags
);
1411 if (gh
->gh_flags
& GL_NOCACHE
)
1412 handle_callback(gl
, LM_ST_UNLOCKED
);
1414 gfs2_glmutex_lock(gl
);
1416 spin_lock(&gl
->gl_spin
);
1417 list_del_init(&gh
->gh_list
);
1419 if (list_empty(&gl
->gl_holders
)) {
1420 spin_unlock(&gl
->gl_spin
);
1422 if (glops
->go_unlock
)
1423 glops
->go_unlock(gh
);
1425 if (test_bit(GLF_SYNC
, &gl
->gl_flags
)) {
1427 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
);
1430 gl
->gl_stamp
= jiffies
;
1432 spin_lock(&gl
->gl_spin
);
1435 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1437 spin_unlock(&gl
->gl_spin
);
1441 * gfs2_glock_prefetch - Try to prefetch a glock
1443 * @state: the state to prefetch in
1444 * @flags: flags passed to go_xmote_th()
1448 void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
1450 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1452 spin_lock(&gl
->gl_spin
);
1454 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1455 !list_empty(&gl
->gl_holders
) ||
1456 !list_empty(&gl
->gl_waiters1
) ||
1457 !list_empty(&gl
->gl_waiters2
) ||
1458 !list_empty(&gl
->gl_waiters3
) ||
1459 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1460 spin_unlock(&gl
->gl_spin
);
1464 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1465 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1466 spin_unlock(&gl
->gl_spin
);
1468 glops
->go_xmote_th(gl
, state
, flags
);
1472 * gfs2_glock_force_drop - Force a glock to be uncached
1477 void gfs2_glock_force_drop(struct gfs2_glock
*gl
)
1479 struct gfs2_holder gh
;
1481 gfs2_holder_init(gl
, LM_ST_UNLOCKED
, GL_NEVER_RECURSE
, &gh
);
1482 set_bit(HIF_DEMOTE
, &gh
.gh_iflags
);
1484 spin_lock(&gl
->gl_spin
);
1485 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters2
);
1487 spin_unlock(&gl
->gl_spin
);
1489 wait_for_completion(&gh
.gh_wait
);
1490 gfs2_holder_uninit(&gh
);
1493 static void greedy_work(void *data
)
1495 struct greedy
*gr
= (struct greedy
*)data
;
1496 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1497 struct gfs2_glock
*gl
= gh
->gh_gl
;
1498 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1500 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1502 if (glops
->go_greedy
)
1503 glops
->go_greedy(gl
);
1505 spin_lock(&gl
->gl_spin
);
1507 if (list_empty(&gl
->gl_waiters2
)) {
1508 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1509 spin_unlock(&gl
->gl_spin
);
1510 gfs2_holder_uninit(gh
);
1513 gfs2_glock_hold(gl
);
1514 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1516 spin_unlock(&gl
->gl_spin
);
1522 * gfs2_glock_be_greedy -
1526 * Returns: 0 if go_greedy will be called, 1 otherwise
1529 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1532 struct gfs2_holder
*gh
;
1535 gl
->gl_sbd
->sd_args
.ar_localcaching
||
1536 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1539 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1541 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1546 gfs2_holder_init(gl
, 0, GL_NEVER_RECURSE
, gh
);
1547 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1548 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1550 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1551 schedule_delayed_work(&gr
->gr_work
, time
);
1557 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1558 * @gh: the holder structure
1562 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1565 gfs2_holder_uninit(gh
);
1569 * gfs2_glock_nq_num - acquire a glock based on lock number
1570 * @sdp: the filesystem
1571 * @number: the lock number
1572 * @glops: the glock operations for the type of glock
1573 * @state: the state to acquire the glock in
1574 * @flags: modifier flags for the aquisition
1575 * @gh: the struct gfs2_holder
1580 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1581 struct gfs2_glock_operations
*glops
, unsigned int state
,
1582 int flags
, struct gfs2_holder
*gh
)
1584 struct gfs2_glock
*gl
;
1587 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1589 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1597 * glock_compare - Compare two struct gfs2_glock structures for sorting
1598 * @arg_a: the first structure
1599 * @arg_b: the second structure
1603 static int glock_compare(const void *arg_a
, const void *arg_b
)
1605 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1606 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1607 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1608 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1611 if (a
->ln_number
> b
->ln_number
)
1613 else if (a
->ln_number
< b
->ln_number
)
1616 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1617 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1619 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1620 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1628 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1629 * @num_gh: the number of structures
1630 * @ghs: an array of struct gfs2_holder structures
1632 * Returns: 0 on success (all glocks acquired),
1633 * errno on failure (no glocks acquired)
1636 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1637 struct gfs2_holder
**p
)
1642 for (x
= 0; x
< num_gh
; x
++)
1645 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1647 for (x
= 0; x
< num_gh
; x
++) {
1648 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1650 error
= gfs2_glock_nq(p
[x
]);
1653 gfs2_glock_dq(p
[x
]);
1662 * gfs2_glock_nq_m - acquire multiple glocks
1663 * @num_gh: the number of structures
1664 * @ghs: an array of struct gfs2_holder structures
1666 * Figure out how big an impact this function has. Either:
1667 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1668 * 2) Forget async stuff and just call nq_m_sync()
1669 * 3) Leave it like it is
1671 * Returns: 0 on success (all glocks acquired),
1672 * errno on failure (no glocks acquired)
1675 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1679 int borked
= 0, serious
= 0;
1686 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1687 return gfs2_glock_nq(ghs
);
1690 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1694 for (x
= 0; x
< num_gh
; x
++) {
1695 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1696 error
= gfs2_glock_nq(&ghs
[x
]);
1705 for (x
= 0; x
< num_gh
; x
++) {
1706 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1709 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1719 for (x
= 0; x
< num_gh
; x
++)
1721 gfs2_glock_dq(&ghs
[x
]);
1726 for (x
= 0; x
< num_gh
; x
++)
1727 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1729 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1738 * gfs2_glock_dq_m - release multiple glocks
1739 * @num_gh: the number of structures
1740 * @ghs: an array of struct gfs2_holder structures
1744 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1748 for (x
= 0; x
< num_gh
; x
++)
1749 gfs2_glock_dq(&ghs
[x
]);
1753 * gfs2_glock_dq_uninit_m - release multiple glocks
1754 * @num_gh: the number of structures
1755 * @ghs: an array of struct gfs2_holder structures
1759 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1763 for (x
= 0; x
< num_gh
; x
++)
1764 gfs2_glock_dq_uninit(&ghs
[x
]);
1768 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1769 * @sdp: the filesystem
1770 * @number: the lock number
1771 * @glops: the glock operations for the type of glock
1772 * @state: the state to acquire the glock in
1773 * @flags: modifier flags for the aquisition
1778 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1779 struct gfs2_glock_operations
*glops
,
1780 unsigned int state
, int flags
)
1782 struct gfs2_glock
*gl
;
1785 if (atomic_read(&sdp
->sd_reclaim_count
) <
1786 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1787 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1789 gfs2_glock_prefetch(gl
, state
, flags
);
1796 * gfs2_lvb_hold - attach a LVB from a glock
1797 * @gl: The glock in question
1801 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1805 gfs2_glmutex_lock(gl
);
1807 if (!atomic_read(&gl
->gl_lvb_count
)) {
1808 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1810 gfs2_glmutex_unlock(gl
);
1813 gfs2_glock_hold(gl
);
1815 atomic_inc(&gl
->gl_lvb_count
);
1817 gfs2_glmutex_unlock(gl
);
1823 * gfs2_lvb_unhold - detach a LVB from a glock
1824 * @gl: The glock in question
1828 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1830 gfs2_glock_hold(gl
);
1831 gfs2_glmutex_lock(gl
);
1833 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1834 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1835 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1840 gfs2_glmutex_unlock(gl
);
1844 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1846 gfs2_glmutex_lock(gl
);
1848 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1849 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1850 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1852 gfs2_glmutex_unlock(gl
);
1855 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1858 struct gfs2_glock
*gl
;
1860 gl
= gfs2_glock_find(sdp
, name
);
1864 if (gl
->gl_ops
->go_callback
)
1865 gl
->gl_ops
->go_callback(gl
, state
);
1866 handle_callback(gl
, state
);
1868 spin_lock(&gl
->gl_spin
);
1870 spin_unlock(&gl
->gl_spin
);
1876 * gfs2_glock_cb - Callback used by locking module
1877 * @fsdata: Pointer to the superblock
1878 * @type: Type of callback
1879 * @data: Type dependent data pointer
1881 * Called by the locking module when it wants to tell us something.
1882 * Either we need to drop a lock, one of our ASYNC requests completed, or
1883 * a journal from another client needs to be recovered.
1886 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1888 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1892 blocking_cb(sdp
, (struct lm_lockname
*)data
, LM_ST_UNLOCKED
);
1896 blocking_cb(sdp
, (struct lm_lockname
*)data
, LM_ST_DEFERRED
);
1900 blocking_cb(sdp
, (struct lm_lockname
*)data
, LM_ST_SHARED
);
1904 struct lm_async_cb
*async
= (struct lm_async_cb
*)data
;
1905 struct gfs2_glock
*gl
;
1907 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1908 if (gfs2_assert_warn(sdp
, gl
))
1910 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1911 gl
->gl_req_bh(gl
, async
->lc_ret
);
1917 case LM_CB_NEED_RECOVERY
:
1918 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1919 if (sdp
->sd_recoverd_process
)
1920 wake_up_process(sdp
->sd_recoverd_process
);
1923 case LM_CB_DROPLOCKS
:
1924 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1925 gfs2_quota_scan(sdp
);
1929 gfs2_assert_warn(sdp
, 0);
1935 * gfs2_try_toss_inode - try to remove a particular inode struct from cache
1936 * sdp: the filesystem
1937 * inum: the inode number
1941 void gfs2_try_toss_inode(struct gfs2_sbd
*sdp
, struct gfs2_inum
*inum
)
1943 struct gfs2_glock
*gl
;
1944 struct gfs2_inode
*ip
;
1947 error
= gfs2_glock_get(sdp
, inum
->no_addr
, &gfs2_inode_glops
,
1952 if (!gfs2_glmutex_trylock(gl
))
1959 if (atomic_read(&ip
->i_count
))
1962 gfs2_inode_destroy(ip
);
1965 gfs2_glmutex_unlock(gl
);
1972 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1973 * iopen glock from memory
1974 * @io_gl: the iopen glock
1975 * @state: the state into which the glock should be put
1979 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1981 struct gfs2_glock
*i_gl
;
1983 if (state
!= LM_ST_UNLOCKED
)
1986 spin_lock(&io_gl
->gl_spin
);
1987 i_gl
= io_gl
->gl_object
;
1989 gfs2_glock_hold(i_gl
);
1990 spin_unlock(&io_gl
->gl_spin
);
1992 spin_unlock(&io_gl
->gl_spin
);
1996 if (gfs2_glmutex_trylock(i_gl
)) {
1997 struct gfs2_inode
*ip
= i_gl
->gl_object
;
1999 gfs2_try_toss_vnode(ip
);
2000 gfs2_glmutex_unlock(i_gl
);
2001 gfs2_glock_schedule_for_reclaim(i_gl
);
2004 gfs2_glmutex_unlock(i_gl
);
2008 gfs2_glock_put(i_gl
);
2012 * demote_ok - Check to see if it's ok to unlock a glock
2015 * Returns: 1 if it's ok
2018 static int demote_ok(struct gfs2_glock
*gl
)
2020 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2021 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
2024 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
2026 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
2027 demote
= time_after_eq(jiffies
,
2029 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
2030 else if (glops
->go_demote_ok
)
2031 demote
= glops
->go_demote_ok(gl
);
2037 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
2042 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
2044 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2046 spin_lock(&sdp
->sd_reclaim_lock
);
2047 if (list_empty(&gl
->gl_reclaim
)) {
2048 gfs2_glock_hold(gl
);
2049 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
2050 atomic_inc(&sdp
->sd_reclaim_count
);
2052 spin_unlock(&sdp
->sd_reclaim_lock
);
2054 wake_up(&sdp
->sd_reclaim_wq
);
2058 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
2059 * @sdp: the filesystem
2061 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
2062 * different glock and we notice that there are a lot of glocks in the
2067 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
2069 struct gfs2_glock
*gl
;
2071 spin_lock(&sdp
->sd_reclaim_lock
);
2072 if (list_empty(&sdp
->sd_reclaim_list
)) {
2073 spin_unlock(&sdp
->sd_reclaim_lock
);
2076 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
2077 struct gfs2_glock
, gl_reclaim
);
2078 list_del_init(&gl
->gl_reclaim
);
2079 spin_unlock(&sdp
->sd_reclaim_lock
);
2081 atomic_dec(&sdp
->sd_reclaim_count
);
2082 atomic_inc(&sdp
->sd_reclaimed
);
2084 if (gfs2_glmutex_trylock(gl
)) {
2085 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2086 struct gfs2_inode
*ip
= gl
->gl_object
;
2087 if (ip
&& !atomic_read(&ip
->i_count
))
2088 gfs2_inode_destroy(ip
);
2090 if (queue_empty(gl
, &gl
->gl_holders
) &&
2091 gl
->gl_state
!= LM_ST_UNLOCKED
&&
2093 handle_callback(gl
, LM_ST_UNLOCKED
);
2094 gfs2_glmutex_unlock(gl
);
2101 * examine_bucket - Call a function for glock in a hash bucket
2102 * @examiner: the function
2103 * @sdp: the filesystem
2104 * @bucket: the bucket
2106 * Returns: 1 if the bucket has entries
2109 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
2110 struct gfs2_gl_hash_bucket
*bucket
)
2112 struct glock_plug plug
;
2113 struct list_head
*tmp
;
2114 struct gfs2_glock
*gl
;
2117 /* Add "plug" to end of bucket list, work back up list from there */
2118 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
2119 set_bit(GLF_PLUG
, &plug
.gl_flags
);
2121 write_lock(&bucket
->hb_lock
);
2122 list_add(&plug
.gl_list
, &bucket
->hb_list
);
2123 write_unlock(&bucket
->hb_lock
);
2126 write_lock(&bucket
->hb_lock
);
2129 tmp
= plug
.gl_list
.next
;
2131 if (tmp
== &bucket
->hb_list
) {
2132 list_del(&plug
.gl_list
);
2133 entries
= !list_empty(&bucket
->hb_list
);
2134 write_unlock(&bucket
->hb_lock
);
2137 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
2139 /* Move plug up list */
2140 list_move(&plug
.gl_list
, &gl
->gl_list
);
2142 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2145 /* examiner() must glock_put() */
2146 gfs2_glock_hold(gl
);
2151 write_unlock(&bucket
->hb_lock
);
2158 * scan_glock - look at a glock and see if we can reclaim it
2159 * @gl: the glock to look at
2163 static void scan_glock(struct gfs2_glock
*gl
)
2165 if (gfs2_glmutex_trylock(gl
)) {
2166 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2167 struct gfs2_inode
*ip
= gl
->gl_object
;
2168 if (ip
&& !atomic_read(&ip
->i_count
))
2171 if (queue_empty(gl
, &gl
->gl_holders
) &&
2172 gl
->gl_state
!= LM_ST_UNLOCKED
&&
2176 gfs2_glmutex_unlock(gl
);
2184 gfs2_glmutex_unlock(gl
);
2185 gfs2_glock_schedule_for_reclaim(gl
);
2190 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
2191 * @sdp: the filesystem
2195 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
2199 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2200 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
2206 * clear_glock - look at a glock and see if we can free it from glock cache
2207 * @gl: the glock to look at
2211 static void clear_glock(struct gfs2_glock
*gl
)
2213 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2216 spin_lock(&sdp
->sd_reclaim_lock
);
2217 if (!list_empty(&gl
->gl_reclaim
)) {
2218 list_del_init(&gl
->gl_reclaim
);
2219 atomic_dec(&sdp
->sd_reclaim_count
);
2220 released
= gfs2_glock_put(gl
);
2221 gfs2_assert(sdp
, !released
);
2223 spin_unlock(&sdp
->sd_reclaim_lock
);
2225 if (gfs2_glmutex_trylock(gl
)) {
2226 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2227 struct gfs2_inode
*ip
= gl
->gl_object
;
2228 if (ip
&& !atomic_read(&ip
->i_count
))
2229 gfs2_inode_destroy(ip
);
2231 if (queue_empty(gl
, &gl
->gl_holders
) &&
2232 gl
->gl_state
!= LM_ST_UNLOCKED
)
2233 handle_callback(gl
, LM_ST_UNLOCKED
);
2235 gfs2_glmutex_unlock(gl
);
2242 * gfs2_gl_hash_clear - Empty out the glock hash table
2243 * @sdp: the filesystem
2244 * @wait: wait until it's all gone
2246 * Called when unmounting the filesystem, or when inter-node lock manager
2247 * requests DROPLOCKS because it is running out of capacity.
2250 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2261 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2262 if (examine_bucket(clear_glock
, sdp
,
2263 &sdp
->sd_gl_hash
[x
]))
2269 if (time_after_eq(jiffies
,
2270 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2271 fs_warn(sdp
, "Unmount seems to be stalled. "
2272 "Dumping lock state...\n");
2273 gfs2_dump_lockstate(sdp
);
2277 /* invalidate_inodes() requires that the sb inodes list
2278 not change, but an async completion callback for an
2279 unlock can occur which does glock_put() which
2280 can call iput() which will change the sb inodes list.
2281 invalidate_inodes_mutex prevents glock_put()'s during
2282 an invalidate_inodes() */
2284 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
2285 invalidate_inodes(sdp
->sd_vfs
);
2286 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
2292 * Diagnostic routines to help debug distributed deadlock
2296 * dump_holder - print information about a glock holder
2297 * @str: a string naming the type of holder
2298 * @gh: the glock holder
2300 * Returns: 0 on success, -ENOBUFS when we run out of space
2303 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2306 int error
= -ENOBUFS
;
2308 printk(KERN_INFO
" %s\n", str
);
2309 printk(KERN_INFO
" owner = %ld\n",
2310 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2311 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2312 printk(KERN_INFO
" gh_flags =");
2313 for (x
= 0; x
< 32; x
++)
2314 if (gh
->gh_flags
& (1 << x
))
2317 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2318 printk(KERN_INFO
" gh_iflags =");
2319 for (x
= 0; x
< 32; x
++)
2320 if (test_bit(x
, &gh
->gh_iflags
))
2323 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2331 * dump_inode - print information about an inode
2334 * Returns: 0 on success, -ENOBUFS when we run out of space
2337 static int dump_inode(struct gfs2_inode
*ip
)
2340 int error
= -ENOBUFS
;
2342 printk(KERN_INFO
" Inode:\n");
2343 printk(KERN_INFO
" num = %llu %llu\n",
2344 ip
->i_num
.no_formal_ino
, ip
->i_num
.no_addr
);
2345 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2346 printk(KERN_INFO
" i_count = %d\n", atomic_read(&ip
->i_count
));
2347 printk(KERN_INFO
" i_flags =");
2348 for (x
= 0; x
< 32; x
++)
2349 if (test_bit(x
, &ip
->i_flags
))
2352 printk(KERN_INFO
" vnode = %s\n", (ip
->i_vnode
) ? "yes" : "no");
2360 * dump_glock - print information about a glock
2362 * @count: where we are in the buffer
2364 * Returns: 0 on success, -ENOBUFS when we run out of space
2367 static int dump_glock(struct gfs2_glock
*gl
)
2369 struct gfs2_holder
*gh
;
2371 int error
= -ENOBUFS
;
2373 spin_lock(&gl
->gl_spin
);
2375 printk(KERN_INFO
"Glock (%u, %llu)\n",
2376 gl
->gl_name
.ln_type
,
2377 gl
->gl_name
.ln_number
);
2378 printk(KERN_INFO
" gl_flags =");
2379 for (x
= 0; x
< 32; x
++)
2380 if (test_bit(x
, &gl
->gl_flags
))
2383 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2384 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2385 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2386 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2387 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2388 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2389 printk(KERN_INFO
" le = %s\n",
2390 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2391 printk(KERN_INFO
" reclaim = %s\n",
2392 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2394 printk(KERN_INFO
" aspace = %lu\n",
2395 gl
->gl_aspace
->i_mapping
->nrpages
);
2397 printk(KERN_INFO
" aspace = no\n");
2398 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2399 if (gl
->gl_req_gh
) {
2400 error
= dump_holder("Request", gl
->gl_req_gh
);
2404 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2405 error
= dump_holder("Holder", gh
);
2409 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2410 error
= dump_holder("Waiter1", gh
);
2414 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2415 error
= dump_holder("Waiter2", gh
);
2419 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2420 error
= dump_holder("Waiter3", gh
);
2424 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2425 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2426 list_empty(&gl
->gl_holders
)) {
2427 error
= dump_inode(gl
->gl_object
);
2432 printk(KERN_INFO
" Inode: busy\n");
2439 spin_unlock(&gl
->gl_spin
);
2445 * gfs2_dump_lockstate - print out the current lockstate
2446 * @sdp: the filesystem
2447 * @ub: the buffer to copy the information into
2449 * If @ub is NULL, dump the lockstate to the console.
2453 int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2455 struct gfs2_gl_hash_bucket
*bucket
;
2456 struct gfs2_glock
*gl
;
2460 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2461 bucket
= &sdp
->sd_gl_hash
[x
];
2463 read_lock(&bucket
->hb_lock
);
2465 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2466 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2469 error
= dump_glock(gl
);
2474 read_unlock(&bucket
->hb_lock
);