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/gfs2_ondisk.h>
20 #include <asm/semaphore.h>
21 #include <asm/uaccess.h>
24 #include "lm_interface.h"
36 /* Must be kept in sync with the beginning of struct gfs2_glock */
38 struct list_head gl_list
;
39 unsigned long gl_flags
;
43 struct gfs2_holder gr_gh
;
44 struct work_struct gr_work
;
47 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
50 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
51 * @actual: the current state of the lock
52 * @requested: the lock state that was requested by the caller
53 * @flags: the modifier flags passed in by the caller
55 * Returns: 1 if the locks are compatible, 0 otherwise
58 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
61 if (actual
== requested
)
67 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
70 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
77 * gl_hash() - Turn glock number into hash bucket number
78 * @lock: The glock number
80 * Returns: The number of the corresponding hash bucket
83 static unsigned int gl_hash(struct lm_lockname
*name
)
87 h
= jhash(&name
->ln_number
, sizeof(uint64_t), 0);
88 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
89 h
&= GFS2_GL_HASH_MASK
;
95 * glock_free() - Perform a few checks and then release struct gfs2_glock
96 * @gl: The glock to release
98 * Also calls lock module to release its internal structure for this glock.
102 static void glock_free(struct gfs2_glock
*gl
)
104 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
105 struct inode
*aspace
= gl
->gl_aspace
;
107 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
110 gfs2_aspace_put(aspace
);
112 kmem_cache_free(gfs2_glock_cachep
, gl
);
116 * gfs2_glock_hold() - increment reference count on glock
117 * @gl: The glock to hold
121 void gfs2_glock_hold(struct gfs2_glock
*gl
)
123 kref_get(&gl
->gl_ref
);
126 /* All work is done after the return from kref_put() so we
127 can release the write_lock before the free. */
129 static void kill_glock(struct kref
*kref
)
131 struct gfs2_glock
*gl
= container_of(kref
, struct gfs2_glock
, gl_ref
);
132 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
134 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
135 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
136 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
137 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
138 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
139 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
143 * gfs2_glock_put() - Decrement reference count on glock
144 * @gl: The glock to put
148 int gfs2_glock_put(struct gfs2_glock
*gl
)
150 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
151 struct gfs2_gl_hash_bucket
*bucket
= gl
->gl_bucket
;
154 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
156 write_lock(&bucket
->hb_lock
);
157 if (kref_put(&gl
->gl_ref
, kill_glock
)) {
158 list_del_init(&gl
->gl_list
);
159 write_unlock(&bucket
->hb_lock
);
164 write_unlock(&bucket
->hb_lock
);
166 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
171 * queue_empty - check to see if a glock's queue is empty
173 * @head: the head of the queue to check
175 * This function protects the list in the event that a process already
176 * has a holder on the list and is adding a second holder for itself.
177 * The glmutex lock is what generally prevents processes from working
178 * on the same glock at once, but the special case of adding a second
179 * holder for yourself ("recursive" locking) doesn't involve locking
180 * glmutex, making the spin lock necessary.
182 * Returns: 1 if the queue is empty
185 static inline int queue_empty(struct gfs2_glock
*gl
, struct list_head
*head
)
188 spin_lock(&gl
->gl_spin
);
189 empty
= list_empty(head
);
190 spin_unlock(&gl
->gl_spin
);
195 * search_bucket() - Find struct gfs2_glock by lock number
196 * @bucket: the bucket to search
197 * @name: The lock name
199 * Returns: NULL, or the struct gfs2_glock with the requested number
202 static struct gfs2_glock
*search_bucket(struct gfs2_gl_hash_bucket
*bucket
,
203 struct lm_lockname
*name
)
205 struct gfs2_glock
*gl
;
207 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
208 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
210 if (!lm_name_equal(&gl
->gl_name
, name
))
213 kref_get(&gl
->gl_ref
);
222 * gfs2_glock_find() - Find glock by lock number
223 * @sdp: The GFS2 superblock
224 * @name: The lock name
226 * Returns: NULL, or the struct gfs2_glock with the requested number
229 struct gfs2_glock
*gfs2_glock_find(struct gfs2_sbd
*sdp
,
230 struct lm_lockname
*name
)
232 struct gfs2_gl_hash_bucket
*bucket
= &sdp
->sd_gl_hash
[gl_hash(name
)];
233 struct gfs2_glock
*gl
;
235 read_lock(&bucket
->hb_lock
);
236 gl
= search_bucket(bucket
, name
);
237 read_unlock(&bucket
->hb_lock
);
243 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
244 * @sdp: The GFS2 superblock
245 * @number: the lock number
246 * @glops: The glock_operations to use
247 * @create: If 0, don't create the glock if it doesn't exist
248 * @glp: the glock is returned here
250 * This does not lock a glock, just finds/creates structures for one.
255 int gfs2_glock_get(struct gfs2_sbd
*sdp
, uint64_t number
,
256 struct gfs2_glock_operations
*glops
, int create
,
257 struct gfs2_glock
**glp
)
259 struct lm_lockname name
;
260 struct gfs2_glock
*gl
, *tmp
;
261 struct gfs2_gl_hash_bucket
*bucket
;
264 name
.ln_number
= number
;
265 name
.ln_type
= glops
->go_type
;
266 bucket
= &sdp
->sd_gl_hash
[gl_hash(&name
)];
268 read_lock(&bucket
->hb_lock
);
269 gl
= search_bucket(bucket
, &name
);
270 read_unlock(&bucket
->hb_lock
);
277 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
281 memset(gl
, 0, sizeof(struct gfs2_glock
));
283 INIT_LIST_HEAD(&gl
->gl_list
);
285 kref_init(&gl
->gl_ref
);
287 spin_lock_init(&gl
->gl_spin
);
289 gl
->gl_state
= LM_ST_UNLOCKED
;
290 INIT_LIST_HEAD(&gl
->gl_holders
);
291 INIT_LIST_HEAD(&gl
->gl_waiters1
);
292 INIT_LIST_HEAD(&gl
->gl_waiters2
);
293 INIT_LIST_HEAD(&gl
->gl_waiters3
);
297 gl
->gl_bucket
= bucket
;
298 INIT_LIST_HEAD(&gl
->gl_reclaim
);
302 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
303 INIT_LIST_HEAD(&gl
->gl_ail_list
);
305 /* If this glock protects actual on-disk data or metadata blocks,
306 create a VFS inode to manage the pages/buffers holding them. */
307 if (glops
== &gfs2_inode_glops
||
308 glops
== &gfs2_rgrp_glops
||
309 glops
== &gfs2_meta_glops
) {
310 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
311 if (!gl
->gl_aspace
) {
317 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
321 write_lock(&bucket
->hb_lock
);
322 tmp
= search_bucket(bucket
, &name
);
324 write_unlock(&bucket
->hb_lock
);
328 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
329 write_unlock(&bucket
->hb_lock
);
338 gfs2_aspace_put(gl
->gl_aspace
);
341 kmem_cache_free(gfs2_glock_cachep
, gl
);
347 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
349 * @state: the state we're requesting
350 * @flags: the modifier flags
351 * @gh: the holder structure
355 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, int flags
,
356 struct gfs2_holder
*gh
)
358 INIT_LIST_HEAD(&gh
->gh_list
);
360 gh
->gh_owner
= (flags
& GL_NEVER_RECURSE
) ? NULL
: current
;
361 gh
->gh_state
= state
;
362 gh
->gh_flags
= flags
;
365 init_completion(&gh
->gh_wait
);
367 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
368 gh
->gh_flags
|= GL_LOCAL_EXCL
;
374 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
375 * @state: the state we're requesting
376 * @flags: the modifier flags
377 * @gh: the holder structure
379 * Don't mess with the glock.
383 void gfs2_holder_reinit(unsigned int state
, int flags
, struct gfs2_holder
*gh
)
385 gh
->gh_state
= state
;
386 gh
->gh_flags
= flags
;
387 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
388 gh
->gh_flags
|= GL_LOCAL_EXCL
;
390 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
394 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
395 * @gh: the holder structure
399 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
401 gfs2_glock_put(gh
->gh_gl
);
406 * gfs2_holder_get - get a struct gfs2_holder structure
408 * @state: the state we're requesting
409 * @flags: the modifier flags
410 * @gfp_flags: __GFP_NOFAIL
412 * Figure out how big an impact this function has. Either:
413 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
414 * 2) Leave it like it is
416 * Returns: the holder structure, NULL on ENOMEM
419 struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
, unsigned int state
,
420 int flags
, gfp_t gfp_flags
)
422 struct gfs2_holder
*gh
;
424 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
428 gfs2_holder_init(gl
, state
, flags
, gh
);
429 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
435 * gfs2_holder_put - get rid of a struct gfs2_holder structure
436 * @gh: the holder structure
440 void gfs2_holder_put(struct gfs2_holder
*gh
)
442 gfs2_holder_uninit(gh
);
447 * handle_recurse - put other holder structures (marked recursive)
448 * into the holders list
449 * @gh: the holder structure
453 static void handle_recurse(struct gfs2_holder
*gh
)
455 struct gfs2_glock
*gl
= gh
->gh_gl
;
456 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
457 struct gfs2_holder
*tmp_gh
, *safe
;
460 if (gfs2_assert_warn(sdp
, gh
->gh_owner
))
463 list_for_each_entry_safe(tmp_gh
, safe
, &gl
->gl_waiters3
, gh_list
) {
464 if (tmp_gh
->gh_owner
!= gh
->gh_owner
)
467 gfs2_assert_warn(sdp
,
468 test_bit(HIF_RECURSE
, &tmp_gh
->gh_iflags
));
470 list_move_tail(&tmp_gh
->gh_list
, &gl
->gl_holders
);
471 tmp_gh
->gh_error
= 0;
472 set_bit(HIF_HOLDER
, &tmp_gh
->gh_iflags
);
474 complete(&tmp_gh
->gh_wait
);
479 gfs2_assert_warn(sdp
, found
);
483 * do_unrecurse - a recursive holder was just dropped of the waiters3 list
486 * If there is only one other recursive holder, clear its HIF_RECURSE bit.
487 * If there is more than one, leave them alone.
491 static void do_unrecurse(struct gfs2_holder
*gh
)
493 struct gfs2_glock
*gl
= gh
->gh_gl
;
494 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
495 struct gfs2_holder
*tmp_gh
, *last_gh
= NULL
;
498 if (gfs2_assert_warn(sdp
, gh
->gh_owner
))
501 list_for_each_entry(tmp_gh
, &gl
->gl_waiters3
, gh_list
) {
502 if (tmp_gh
->gh_owner
!= gh
->gh_owner
)
505 gfs2_assert_warn(sdp
,
506 test_bit(HIF_RECURSE
, &tmp_gh
->gh_iflags
));
515 if (!gfs2_assert_warn(sdp
, found
))
516 clear_bit(HIF_RECURSE
, &last_gh
->gh_iflags
);
520 * rq_mutex - process a mutex request in the queue
521 * @gh: the glock holder
523 * Returns: 1 if the queue is blocked
526 static int rq_mutex(struct gfs2_holder
*gh
)
528 struct gfs2_glock
*gl
= gh
->gh_gl
;
530 list_del_init(&gh
->gh_list
);
531 /* gh->gh_error never examined. */
532 set_bit(GLF_LOCK
, &gl
->gl_flags
);
533 complete(&gh
->gh_wait
);
539 * rq_promote - process a promote request in the queue
540 * @gh: the glock holder
542 * Acquire a new inter-node lock, or change a lock state to more restrictive.
544 * Returns: 1 if the queue is blocked
547 static int rq_promote(struct gfs2_holder
*gh
)
549 struct gfs2_glock
*gl
= gh
->gh_gl
;
550 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
551 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
554 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
555 if (list_empty(&gl
->gl_holders
)) {
557 set_bit(GLF_LOCK
, &gl
->gl_flags
);
558 spin_unlock(&gl
->gl_spin
);
560 if (atomic_read(&sdp
->sd_reclaim_count
) >
561 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
562 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
563 gfs2_reclaim_glock(sdp
);
564 gfs2_reclaim_glock(sdp
);
567 glops
->go_xmote_th(gl
, gh
->gh_state
,
570 spin_lock(&gl
->gl_spin
);
575 if (list_empty(&gl
->gl_holders
)) {
576 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
577 set_bit(GLF_LOCK
, &gl
->gl_flags
);
580 struct gfs2_holder
*next_gh
;
581 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
583 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
585 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
587 recurse
= test_bit(HIF_RECURSE
, &gh
->gh_iflags
);
590 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
592 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
597 complete(&gh
->gh_wait
);
603 * rq_demote - process a demote request in the queue
604 * @gh: the glock holder
606 * Returns: 1 if the queue is blocked
609 static int rq_demote(struct gfs2_holder
*gh
)
611 struct gfs2_glock
*gl
= gh
->gh_gl
;
612 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
614 if (!list_empty(&gl
->gl_holders
))
617 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
618 list_del_init(&gh
->gh_list
);
620 spin_unlock(&gl
->gl_spin
);
621 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
624 complete(&gh
->gh_wait
);
625 spin_lock(&gl
->gl_spin
);
628 set_bit(GLF_LOCK
, &gl
->gl_flags
);
629 spin_unlock(&gl
->gl_spin
);
631 if (gh
->gh_state
== LM_ST_UNLOCKED
||
632 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
633 glops
->go_drop_th(gl
);
635 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
637 spin_lock(&gl
->gl_spin
);
644 * rq_greedy - process a queued request to drop greedy status
645 * @gh: the glock holder
647 * Returns: 1 if the queue is blocked
650 static int rq_greedy(struct gfs2_holder
*gh
)
652 struct gfs2_glock
*gl
= gh
->gh_gl
;
654 list_del_init(&gh
->gh_list
);
655 /* gh->gh_error never examined. */
656 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
657 spin_unlock(&gl
->gl_spin
);
659 gfs2_holder_uninit(gh
);
660 kfree(container_of(gh
, struct greedy
, gr_gh
));
662 spin_lock(&gl
->gl_spin
);
668 * run_queue - process holder structures on a glock
673 static void run_queue(struct gfs2_glock
*gl
)
675 struct gfs2_holder
*gh
;
679 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
682 if (!list_empty(&gl
->gl_waiters1
)) {
683 gh
= list_entry(gl
->gl_waiters1
.next
,
684 struct gfs2_holder
, gh_list
);
686 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
687 blocked
= rq_mutex(gh
);
689 gfs2_assert_warn(gl
->gl_sbd
, 0);
691 } else if (!list_empty(&gl
->gl_waiters2
) &&
692 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
693 gh
= list_entry(gl
->gl_waiters2
.next
,
694 struct gfs2_holder
, gh_list
);
696 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
697 blocked
= rq_demote(gh
);
698 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
699 blocked
= rq_greedy(gh
);
701 gfs2_assert_warn(gl
->gl_sbd
, 0);
703 } else if (!list_empty(&gl
->gl_waiters3
)) {
704 gh
= list_entry(gl
->gl_waiters3
.next
,
705 struct gfs2_holder
, gh_list
);
707 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
708 blocked
= rq_promote(gh
);
710 gfs2_assert_warn(gl
->gl_sbd
, 0);
721 * gfs2_glmutex_lock - acquire a local lock on a glock
724 * Gives caller exclusive access to manipulate a glock structure.
727 void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
729 struct gfs2_holder gh
;
731 gfs2_holder_init(gl
, 0, 0, &gh
);
732 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
734 spin_lock(&gl
->gl_spin
);
735 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
736 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
738 complete(&gh
.gh_wait
);
739 spin_unlock(&gl
->gl_spin
);
741 wait_for_completion(&gh
.gh_wait
);
742 gfs2_holder_uninit(&gh
);
746 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
749 * Returns: 1 if the glock is acquired
752 int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
756 spin_lock(&gl
->gl_spin
);
757 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
759 spin_unlock(&gl
->gl_spin
);
765 * gfs2_glmutex_unlock - release a local lock on a glock
770 void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
772 spin_lock(&gl
->gl_spin
);
773 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
775 spin_unlock(&gl
->gl_spin
);
779 * handle_callback - add a demote request to a lock's queue
781 * @state: the state the caller wants us to change to
785 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
787 struct gfs2_holder
*gh
, *new_gh
= NULL
;
790 spin_lock(&gl
->gl_spin
);
792 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
793 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
794 gl
->gl_req_gh
!= gh
) {
795 if (gh
->gh_state
!= state
)
796 gh
->gh_state
= LM_ST_UNLOCKED
;
802 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
805 spin_unlock(&gl
->gl_spin
);
807 new_gh
= gfs2_holder_get(gl
, state
,
808 LM_FLAG_TRY
| GL_NEVER_RECURSE
,
809 GFP_KERNEL
| __GFP_NOFAIL
),
810 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
811 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
817 spin_unlock(&gl
->gl_spin
);
820 gfs2_holder_put(new_gh
);
824 * state_change - record that the glock is now in a different state
826 * @new_state the new state
830 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
834 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
835 held2
= (new_state
!= LM_ST_UNLOCKED
);
837 if (held1
!= held2
) {
844 gl
->gl_state
= new_state
;
848 * xmote_bh - Called after the lock module is done acquiring a lock
849 * @gl: The glock in question
850 * @ret: the int returned from the lock module
854 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
856 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
857 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
858 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
859 int prev_state
= gl
->gl_state
;
862 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
863 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
864 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
866 state_change(gl
, ret
& LM_OUT_ST_MASK
);
868 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
870 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
871 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
872 /* We might not want to do this here.
873 Look at moving to the inode glops. */
875 glops
->go_inval(gl
, DIO_DATA
);
878 /* Deal with each possible exit condition */
881 gl
->gl_stamp
= jiffies
;
883 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
884 spin_lock(&gl
->gl_spin
);
885 list_del_init(&gh
->gh_list
);
887 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
889 spin_unlock(&gl
->gl_spin
);
891 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
892 spin_lock(&gl
->gl_spin
);
893 list_del_init(&gh
->gh_list
);
894 if (gl
->gl_state
== gh
->gh_state
||
895 gl
->gl_state
== LM_ST_UNLOCKED
)
898 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
899 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
900 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
901 gh
->gh_error
= GLR_TRYFAILED
;
903 spin_unlock(&gl
->gl_spin
);
905 if (ret
& LM_OUT_CANCELED
)
906 handle_callback(gl
, LM_ST_UNLOCKED
); /* Lame */
908 } else if (ret
& LM_OUT_CANCELED
) {
909 spin_lock(&gl
->gl_spin
);
910 list_del_init(&gh
->gh_list
);
911 gh
->gh_error
= GLR_CANCELED
;
912 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
914 spin_unlock(&gl
->gl_spin
);
916 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
917 spin_lock(&gl
->gl_spin
);
918 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
920 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
921 spin_unlock(&gl
->gl_spin
);
923 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
927 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
928 spin_lock(&gl
->gl_spin
);
929 list_del_init(&gh
->gh_list
);
930 gh
->gh_error
= GLR_TRYFAILED
;
931 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
933 spin_unlock(&gl
->gl_spin
);
936 if (gfs2_assert_withdraw(sdp
, 0) == -1)
937 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
940 if (glops
->go_xmote_bh
)
941 glops
->go_xmote_bh(gl
);
944 spin_lock(&gl
->gl_spin
);
945 gl
->gl_req_gh
= NULL
;
946 gl
->gl_req_bh
= NULL
;
947 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
949 spin_unlock(&gl
->gl_spin
);
955 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
958 complete(&gh
->gh_wait
);
963 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
964 * @gl: The glock in question
965 * @state: the requested state
966 * @flags: modifier flags to the lock call
970 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
972 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
973 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
974 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
975 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
977 unsigned int lck_ret
;
979 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
980 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
981 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
982 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
984 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
987 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
991 gl
->gl_req_bh
= xmote_bh
;
993 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
,
996 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
999 if (lck_ret
& LM_OUT_ASYNC
)
1000 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
1002 xmote_bh(gl
, lck_ret
);
1006 * drop_bh - Called after a lock module unlock completes
1008 * @ret: the return status
1010 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
1011 * Doesn't drop the reference on the glock the top half took out
1015 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
1017 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1018 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1019 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
1021 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1023 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1024 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1025 gfs2_assert_warn(sdp
, !ret
);
1027 state_change(gl
, LM_ST_UNLOCKED
);
1029 if (glops
->go_inval
)
1030 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
1033 spin_lock(&gl
->gl_spin
);
1034 list_del_init(&gh
->gh_list
);
1036 spin_unlock(&gl
->gl_spin
);
1039 if (glops
->go_drop_bh
)
1040 glops
->go_drop_bh(gl
);
1042 spin_lock(&gl
->gl_spin
);
1043 gl
->gl_req_gh
= NULL
;
1044 gl
->gl_req_bh
= NULL
;
1045 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1047 spin_unlock(&gl
->gl_spin
);
1052 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
1053 gfs2_holder_put(gh
);
1055 complete(&gh
->gh_wait
);
1060 * gfs2_glock_drop_th - call into the lock module to unlock a lock
1065 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
1067 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1068 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1071 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1072 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1073 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1075 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1078 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1081 gfs2_glock_hold(gl
);
1082 gl
->gl_req_bh
= drop_bh
;
1084 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1086 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1092 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1096 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1097 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1099 * Don't cancel GL_NOCANCEL requests.
1102 static void do_cancels(struct gfs2_holder
*gh
)
1104 struct gfs2_glock
*gl
= gh
->gh_gl
;
1106 spin_lock(&gl
->gl_spin
);
1108 while (gl
->gl_req_gh
!= gh
&&
1109 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1110 !list_empty(&gh
->gh_list
)) {
1111 if (gl
->gl_req_bh
&&
1113 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1114 spin_unlock(&gl
->gl_spin
);
1115 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1117 spin_lock(&gl
->gl_spin
);
1119 spin_unlock(&gl
->gl_spin
);
1121 spin_lock(&gl
->gl_spin
);
1125 spin_unlock(&gl
->gl_spin
);
1129 * glock_wait_internal - wait on a glock acquisition
1130 * @gh: the glock holder
1132 * Returns: 0 on success
1135 static int glock_wait_internal(struct gfs2_holder
*gh
)
1137 struct gfs2_glock
*gl
= gh
->gh_gl
;
1138 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1139 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1141 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1144 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1145 spin_lock(&gl
->gl_spin
);
1146 if (gl
->gl_req_gh
!= gh
&&
1147 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1148 !list_empty(&gh
->gh_list
)) {
1149 list_del_init(&gh
->gh_list
);
1150 gh
->gh_error
= GLR_TRYFAILED
;
1151 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
1154 spin_unlock(&gl
->gl_spin
);
1155 return gh
->gh_error
;
1157 spin_unlock(&gl
->gl_spin
);
1160 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1163 wait_for_completion(&gh
->gh_wait
);
1166 return gh
->gh_error
;
1168 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1169 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1173 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1174 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1176 if (glops
->go_lock
) {
1177 gh
->gh_error
= glops
->go_lock(gh
);
1179 spin_lock(&gl
->gl_spin
);
1180 list_del_init(&gh
->gh_list
);
1181 if (test_and_clear_bit(HIF_RECURSE
,
1184 spin_unlock(&gl
->gl_spin
);
1188 spin_lock(&gl
->gl_spin
);
1189 gl
->gl_req_gh
= NULL
;
1190 gl
->gl_req_bh
= NULL
;
1191 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1192 if (test_bit(HIF_RECURSE
, &gh
->gh_iflags
))
1195 spin_unlock(&gl
->gl_spin
);
1198 return gh
->gh_error
;
1201 static inline struct gfs2_holder
*
1202 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1204 struct gfs2_holder
*gh
;
1206 list_for_each_entry(gh
, head
, gh_list
) {
1207 if (gh
->gh_owner
== owner
)
1217 * Make sure the new holder is compatible with the pre-existing one.
1221 static int recurse_check(struct gfs2_holder
*existing
, struct gfs2_holder
*new,
1224 struct gfs2_sbd
*sdp
= existing
->gh_gl
->gl_sbd
;
1226 if (gfs2_assert_warn(sdp
, (new->gh_flags
& LM_FLAG_ANY
) ||
1227 !(existing
->gh_flags
& LM_FLAG_ANY
)))
1230 if (gfs2_assert_warn(sdp
, (existing
->gh_flags
& GL_LOCAL_EXCL
) ||
1231 !(new->gh_flags
& GL_LOCAL_EXCL
)))
1234 if (gfs2_assert_warn(sdp
, relaxed_state_ok(state
, new->gh_state
,
1241 set_bit(HIF_ABORTED
, &new->gh_iflags
);
1246 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1247 * @gh: the holder structure to add
1251 static void add_to_queue(struct gfs2_holder
*gh
)
1253 struct gfs2_glock
*gl
= gh
->gh_gl
;
1254 struct gfs2_holder
*existing
;
1259 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1261 if (recurse_check(existing
, gh
, gl
->gl_state
))
1264 list_add_tail(&gh
->gh_list
, &gl
->gl_holders
);
1265 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
1268 complete(&gh
->gh_wait
);
1273 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1275 if (recurse_check(existing
, gh
, existing
->gh_state
))
1278 set_bit(HIF_RECURSE
, &gh
->gh_iflags
);
1279 set_bit(HIF_RECURSE
, &existing
->gh_iflags
);
1281 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1287 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1288 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1290 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1294 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1295 * @gh: the holder structure
1297 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1299 * Returns: 0, GLR_TRYFAILED, or errno on failure
1302 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1304 struct gfs2_glock
*gl
= gh
->gh_gl
;
1305 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1309 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1310 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1314 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1316 spin_lock(&gl
->gl_spin
);
1319 spin_unlock(&gl
->gl_spin
);
1321 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1322 error
= glock_wait_internal(gh
);
1323 if (error
== GLR_CANCELED
) {
1329 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1335 * gfs2_glock_poll - poll to see if an async request has been completed
1338 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1341 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1343 struct gfs2_glock
*gl
= gh
->gh_gl
;
1346 spin_lock(&gl
->gl_spin
);
1348 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1350 else if (list_empty(&gh
->gh_list
)) {
1351 if (gh
->gh_error
== GLR_CANCELED
) {
1352 spin_unlock(&gl
->gl_spin
);
1354 if (gfs2_glock_nq(gh
))
1361 spin_unlock(&gl
->gl_spin
);
1367 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1368 * @gh: the holder structure
1370 * Returns: 0, GLR_TRYFAILED, or errno on failure
1373 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1377 error
= glock_wait_internal(gh
);
1378 if (error
== GLR_CANCELED
) {
1380 gh
->gh_flags
&= ~GL_ASYNC
;
1381 error
= gfs2_glock_nq(gh
);
1388 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1389 * @gh: the glock holder
1393 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1395 struct gfs2_glock
*gl
= gh
->gh_gl
;
1396 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1398 if (gh
->gh_flags
& GL_SYNC
)
1399 set_bit(GLF_SYNC
, &gl
->gl_flags
);
1401 if (gh
->gh_flags
& GL_NOCACHE
)
1402 handle_callback(gl
, LM_ST_UNLOCKED
);
1404 gfs2_glmutex_lock(gl
);
1406 spin_lock(&gl
->gl_spin
);
1407 list_del_init(&gh
->gh_list
);
1409 if (list_empty(&gl
->gl_holders
)) {
1410 spin_unlock(&gl
->gl_spin
);
1412 if (glops
->go_unlock
)
1413 glops
->go_unlock(gh
);
1415 if (test_bit(GLF_SYNC
, &gl
->gl_flags
)) {
1417 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
);
1420 gl
->gl_stamp
= jiffies
;
1422 spin_lock(&gl
->gl_spin
);
1425 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1427 spin_unlock(&gl
->gl_spin
);
1431 * gfs2_glock_prefetch - Try to prefetch a glock
1433 * @state: the state to prefetch in
1434 * @flags: flags passed to go_xmote_th()
1438 void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
1440 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1442 spin_lock(&gl
->gl_spin
);
1444 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1445 !list_empty(&gl
->gl_holders
) ||
1446 !list_empty(&gl
->gl_waiters1
) ||
1447 !list_empty(&gl
->gl_waiters2
) ||
1448 !list_empty(&gl
->gl_waiters3
) ||
1449 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1450 spin_unlock(&gl
->gl_spin
);
1454 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1455 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1456 spin_unlock(&gl
->gl_spin
);
1458 glops
->go_xmote_th(gl
, state
, flags
);
1462 * gfs2_glock_force_drop - Force a glock to be uncached
1467 void gfs2_glock_force_drop(struct gfs2_glock
*gl
)
1469 struct gfs2_holder gh
;
1471 gfs2_holder_init(gl
, LM_ST_UNLOCKED
, GL_NEVER_RECURSE
, &gh
);
1472 set_bit(HIF_DEMOTE
, &gh
.gh_iflags
);
1474 spin_lock(&gl
->gl_spin
);
1475 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters2
);
1477 spin_unlock(&gl
->gl_spin
);
1479 wait_for_completion(&gh
.gh_wait
);
1480 gfs2_holder_uninit(&gh
);
1483 static void greedy_work(void *data
)
1485 struct greedy
*gr
= (struct greedy
*)data
;
1486 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1487 struct gfs2_glock
*gl
= gh
->gh_gl
;
1488 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1490 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1492 if (glops
->go_greedy
)
1493 glops
->go_greedy(gl
);
1495 spin_lock(&gl
->gl_spin
);
1497 if (list_empty(&gl
->gl_waiters2
)) {
1498 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1499 spin_unlock(&gl
->gl_spin
);
1500 gfs2_holder_uninit(gh
);
1503 gfs2_glock_hold(gl
);
1504 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1506 spin_unlock(&gl
->gl_spin
);
1512 * gfs2_glock_be_greedy -
1516 * Returns: 0 if go_greedy will be called, 1 otherwise
1519 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1522 struct gfs2_holder
*gh
;
1525 gl
->gl_sbd
->sd_args
.ar_localcaching
||
1526 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1529 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1531 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1536 gfs2_holder_init(gl
, 0, GL_NEVER_RECURSE
, gh
);
1537 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1538 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1540 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1541 schedule_delayed_work(&gr
->gr_work
, time
);
1547 * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
1549 * @state: the state we're requesting
1550 * @flags: the modifier flags
1551 * @gh: the holder structure
1553 * Returns: 0, GLR_*, or errno
1556 int gfs2_glock_nq_init(struct gfs2_glock
*gl
, unsigned int state
, int flags
,
1557 struct gfs2_holder
*gh
)
1561 gfs2_holder_init(gl
, state
, flags
, gh
);
1563 error
= gfs2_glock_nq(gh
);
1565 gfs2_holder_uninit(gh
);
1571 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1572 * @gh: the holder structure
1576 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1579 gfs2_holder_uninit(gh
);
1583 * gfs2_glock_nq_num - acquire a glock based on lock number
1584 * @sdp: the filesystem
1585 * @number: the lock number
1586 * @glops: the glock operations for the type of glock
1587 * @state: the state to acquire the glock in
1588 * @flags: modifier flags for the aquisition
1589 * @gh: the struct gfs2_holder
1594 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1595 struct gfs2_glock_operations
*glops
, unsigned int state
,
1596 int flags
, struct gfs2_holder
*gh
)
1598 struct gfs2_glock
*gl
;
1601 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1603 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1611 * glock_compare - Compare two struct gfs2_glock structures for sorting
1612 * @arg_a: the first structure
1613 * @arg_b: the second structure
1617 static int glock_compare(const void *arg_a
, const void *arg_b
)
1619 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1620 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1621 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1622 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1625 if (a
->ln_number
> b
->ln_number
)
1627 else if (a
->ln_number
< b
->ln_number
)
1630 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1631 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1633 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1634 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1642 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1643 * @num_gh: the number of structures
1644 * @ghs: an array of struct gfs2_holder structures
1646 * Returns: 0 on success (all glocks acquired),
1647 * errno on failure (no glocks acquired)
1650 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1651 struct gfs2_holder
**p
)
1656 for (x
= 0; x
< num_gh
; x
++)
1659 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1661 for (x
= 0; x
< num_gh
; x
++) {
1662 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1664 error
= gfs2_glock_nq(p
[x
]);
1667 gfs2_glock_dq(p
[x
]);
1676 * gfs2_glock_nq_m - acquire multiple glocks
1677 * @num_gh: the number of structures
1678 * @ghs: an array of struct gfs2_holder structures
1680 * Figure out how big an impact this function has. Either:
1681 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1682 * 2) Forget async stuff and just call nq_m_sync()
1683 * 3) Leave it like it is
1685 * Returns: 0 on success (all glocks acquired),
1686 * errno on failure (no glocks acquired)
1689 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1693 int borked
= 0, serious
= 0;
1700 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1701 return gfs2_glock_nq(ghs
);
1704 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1708 for (x
= 0; x
< num_gh
; x
++) {
1709 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1710 error
= gfs2_glock_nq(&ghs
[x
]);
1719 for (x
= 0; x
< num_gh
; x
++) {
1720 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1723 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1733 for (x
= 0; x
< num_gh
; x
++)
1735 gfs2_glock_dq(&ghs
[x
]);
1740 for (x
= 0; x
< num_gh
; x
++)
1741 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1743 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1752 * gfs2_glock_dq_m - release multiple glocks
1753 * @num_gh: the number of structures
1754 * @ghs: an array of struct gfs2_holder structures
1758 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1762 for (x
= 0; x
< num_gh
; x
++)
1763 gfs2_glock_dq(&ghs
[x
]);
1767 * gfs2_glock_dq_uninit_m - release multiple glocks
1768 * @num_gh: the number of structures
1769 * @ghs: an array of struct gfs2_holder structures
1773 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1777 for (x
= 0; x
< num_gh
; x
++)
1778 gfs2_glock_dq_uninit(&ghs
[x
]);
1782 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1783 * @sdp: the filesystem
1784 * @number: the lock number
1785 * @glops: the glock operations for the type of glock
1786 * @state: the state to acquire the glock in
1787 * @flags: modifier flags for the aquisition
1792 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1793 struct gfs2_glock_operations
*glops
,
1794 unsigned int state
, int flags
)
1796 struct gfs2_glock
*gl
;
1799 if (atomic_read(&sdp
->sd_reclaim_count
) <
1800 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1801 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1803 gfs2_glock_prefetch(gl
, state
, flags
);
1810 * gfs2_lvb_hold - attach a LVB from a glock
1811 * @gl: The glock in question
1815 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1819 gfs2_glmutex_lock(gl
);
1821 if (!atomic_read(&gl
->gl_lvb_count
)) {
1822 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1824 gfs2_glmutex_unlock(gl
);
1827 gfs2_glock_hold(gl
);
1829 atomic_inc(&gl
->gl_lvb_count
);
1831 gfs2_glmutex_unlock(gl
);
1837 * gfs2_lvb_unhold - detach a LVB from a glock
1838 * @gl: The glock in question
1842 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1844 gfs2_glock_hold(gl
);
1845 gfs2_glmutex_lock(gl
);
1847 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1848 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1849 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1854 gfs2_glmutex_unlock(gl
);
1858 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1860 gfs2_glmutex_lock(gl
);
1862 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1863 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1864 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1866 gfs2_glmutex_unlock(gl
);
1869 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1872 struct gfs2_glock
*gl
;
1874 gl
= gfs2_glock_find(sdp
, name
);
1878 if (gl
->gl_ops
->go_callback
)
1879 gl
->gl_ops
->go_callback(gl
, state
);
1880 handle_callback(gl
, state
);
1882 spin_lock(&gl
->gl_spin
);
1884 spin_unlock(&gl
->gl_spin
);
1890 * gfs2_glock_cb - Callback used by locking module
1891 * @fsdata: Pointer to the superblock
1892 * @type: Type of callback
1893 * @data: Type dependent data pointer
1895 * Called by the locking module when it wants to tell us something.
1896 * Either we need to drop a lock, one of our ASYNC requests completed, or
1897 * a journal from another client needs to be recovered.
1900 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1902 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1906 blocking_cb(sdp
, (struct lm_lockname
*)data
, LM_ST_UNLOCKED
);
1910 blocking_cb(sdp
, (struct lm_lockname
*)data
, LM_ST_DEFERRED
);
1914 blocking_cb(sdp
, (struct lm_lockname
*)data
, LM_ST_SHARED
);
1918 struct lm_async_cb
*async
= (struct lm_async_cb
*)data
;
1919 struct gfs2_glock
*gl
;
1921 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1922 if (gfs2_assert_warn(sdp
, gl
))
1924 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1925 gl
->gl_req_bh(gl
, async
->lc_ret
);
1931 case LM_CB_NEED_RECOVERY
:
1932 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1933 if (sdp
->sd_recoverd_process
)
1934 wake_up_process(sdp
->sd_recoverd_process
);
1937 case LM_CB_DROPLOCKS
:
1938 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1939 gfs2_quota_scan(sdp
);
1943 gfs2_assert_warn(sdp
, 0);
1949 * gfs2_try_toss_inode - try to remove a particular inode struct from cache
1950 * sdp: the filesystem
1951 * inum: the inode number
1955 void gfs2_try_toss_inode(struct gfs2_sbd
*sdp
, struct gfs2_inum
*inum
)
1957 struct gfs2_glock
*gl
;
1958 struct gfs2_inode
*ip
;
1961 error
= gfs2_glock_get(sdp
, inum
->no_addr
, &gfs2_inode_glops
,
1966 if (!gfs2_glmutex_trylock(gl
))
1973 if (atomic_read(&ip
->i_count
))
1976 gfs2_inode_destroy(ip
);
1979 gfs2_glmutex_unlock(gl
);
1986 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1987 * iopen glock from memory
1988 * @io_gl: the iopen glock
1989 * @state: the state into which the glock should be put
1993 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1995 struct gfs2_glock
*i_gl
;
1997 if (state
!= LM_ST_UNLOCKED
)
2000 spin_lock(&io_gl
->gl_spin
);
2001 i_gl
= io_gl
->gl_object
;
2003 gfs2_glock_hold(i_gl
);
2004 spin_unlock(&io_gl
->gl_spin
);
2006 spin_unlock(&io_gl
->gl_spin
);
2010 if (gfs2_glmutex_trylock(i_gl
)) {
2011 struct gfs2_inode
*ip
= i_gl
->gl_object
;
2013 gfs2_try_toss_vnode(ip
);
2014 gfs2_glmutex_unlock(i_gl
);
2015 gfs2_glock_schedule_for_reclaim(i_gl
);
2018 gfs2_glmutex_unlock(i_gl
);
2022 gfs2_glock_put(i_gl
);
2026 * demote_ok - Check to see if it's ok to unlock a glock
2029 * Returns: 1 if it's ok
2032 static int demote_ok(struct gfs2_glock
*gl
)
2034 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2035 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
2038 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
2040 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
2041 demote
= time_after_eq(jiffies
,
2043 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
2044 else if (glops
->go_demote_ok
)
2045 demote
= glops
->go_demote_ok(gl
);
2051 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
2056 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
2058 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2060 spin_lock(&sdp
->sd_reclaim_lock
);
2061 if (list_empty(&gl
->gl_reclaim
)) {
2062 gfs2_glock_hold(gl
);
2063 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
2064 atomic_inc(&sdp
->sd_reclaim_count
);
2066 spin_unlock(&sdp
->sd_reclaim_lock
);
2068 wake_up(&sdp
->sd_reclaim_wq
);
2072 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
2073 * @sdp: the filesystem
2075 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
2076 * different glock and we notice that there are a lot of glocks in the
2081 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
2083 struct gfs2_glock
*gl
;
2085 spin_lock(&sdp
->sd_reclaim_lock
);
2086 if (list_empty(&sdp
->sd_reclaim_list
)) {
2087 spin_unlock(&sdp
->sd_reclaim_lock
);
2090 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
2091 struct gfs2_glock
, gl_reclaim
);
2092 list_del_init(&gl
->gl_reclaim
);
2093 spin_unlock(&sdp
->sd_reclaim_lock
);
2095 atomic_dec(&sdp
->sd_reclaim_count
);
2096 atomic_inc(&sdp
->sd_reclaimed
);
2098 if (gfs2_glmutex_trylock(gl
)) {
2099 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2100 struct gfs2_inode
*ip
= gl
->gl_object
;
2101 if (ip
&& !atomic_read(&ip
->i_count
))
2102 gfs2_inode_destroy(ip
);
2104 if (queue_empty(gl
, &gl
->gl_holders
) &&
2105 gl
->gl_state
!= LM_ST_UNLOCKED
&&
2107 handle_callback(gl
, LM_ST_UNLOCKED
);
2108 gfs2_glmutex_unlock(gl
);
2115 * examine_bucket - Call a function for glock in a hash bucket
2116 * @examiner: the function
2117 * @sdp: the filesystem
2118 * @bucket: the bucket
2120 * Returns: 1 if the bucket has entries
2123 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
2124 struct gfs2_gl_hash_bucket
*bucket
)
2126 struct glock_plug plug
;
2127 struct list_head
*tmp
;
2128 struct gfs2_glock
*gl
;
2131 /* Add "plug" to end of bucket list, work back up list from there */
2132 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
2133 set_bit(GLF_PLUG
, &plug
.gl_flags
);
2135 write_lock(&bucket
->hb_lock
);
2136 list_add(&plug
.gl_list
, &bucket
->hb_list
);
2137 write_unlock(&bucket
->hb_lock
);
2140 write_lock(&bucket
->hb_lock
);
2143 tmp
= plug
.gl_list
.next
;
2145 if (tmp
== &bucket
->hb_list
) {
2146 list_del(&plug
.gl_list
);
2147 entries
= !list_empty(&bucket
->hb_list
);
2148 write_unlock(&bucket
->hb_lock
);
2151 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
2153 /* Move plug up list */
2154 list_move(&plug
.gl_list
, &gl
->gl_list
);
2156 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2159 /* examiner() must glock_put() */
2160 gfs2_glock_hold(gl
);
2165 write_unlock(&bucket
->hb_lock
);
2172 * scan_glock - look at a glock and see if we can reclaim it
2173 * @gl: the glock to look at
2177 static void scan_glock(struct gfs2_glock
*gl
)
2179 if (gfs2_glmutex_trylock(gl
)) {
2180 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2181 struct gfs2_inode
*ip
= gl
->gl_object
;
2182 if (ip
&& !atomic_read(&ip
->i_count
))
2185 if (queue_empty(gl
, &gl
->gl_holders
) &&
2186 gl
->gl_state
!= LM_ST_UNLOCKED
&&
2190 gfs2_glmutex_unlock(gl
);
2198 gfs2_glmutex_unlock(gl
);
2199 gfs2_glock_schedule_for_reclaim(gl
);
2204 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
2205 * @sdp: the filesystem
2209 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
2213 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2214 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
2220 * clear_glock - look at a glock and see if we can free it from glock cache
2221 * @gl: the glock to look at
2225 static void clear_glock(struct gfs2_glock
*gl
)
2227 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2230 spin_lock(&sdp
->sd_reclaim_lock
);
2231 if (!list_empty(&gl
->gl_reclaim
)) {
2232 list_del_init(&gl
->gl_reclaim
);
2233 atomic_dec(&sdp
->sd_reclaim_count
);
2234 released
= gfs2_glock_put(gl
);
2235 gfs2_assert(sdp
, !released
);
2237 spin_unlock(&sdp
->sd_reclaim_lock
);
2239 if (gfs2_glmutex_trylock(gl
)) {
2240 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2241 struct gfs2_inode
*ip
= gl
->gl_object
;
2242 if (ip
&& !atomic_read(&ip
->i_count
))
2243 gfs2_inode_destroy(ip
);
2245 if (queue_empty(gl
, &gl
->gl_holders
) &&
2246 gl
->gl_state
!= LM_ST_UNLOCKED
)
2247 handle_callback(gl
, LM_ST_UNLOCKED
);
2249 gfs2_glmutex_unlock(gl
);
2256 * gfs2_gl_hash_clear - Empty out the glock hash table
2257 * @sdp: the filesystem
2258 * @wait: wait until it's all gone
2260 * Called when unmounting the filesystem, or when inter-node lock manager
2261 * requests DROPLOCKS because it is running out of capacity.
2264 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2275 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2276 if (examine_bucket(clear_glock
, sdp
,
2277 &sdp
->sd_gl_hash
[x
]))
2283 if (time_after_eq(jiffies
,
2284 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2285 fs_warn(sdp
, "Unmount seems to be stalled. "
2286 "Dumping lock state...\n");
2287 gfs2_dump_lockstate(sdp
);
2291 /* invalidate_inodes() requires that the sb inodes list
2292 not change, but an async completion callback for an
2293 unlock can occur which does glock_put() which
2294 can call iput() which will change the sb inodes list.
2295 invalidate_inodes_mutex prevents glock_put()'s during
2296 an invalidate_inodes() */
2298 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
2299 invalidate_inodes(sdp
->sd_vfs
);
2300 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
2306 * Diagnostic routines to help debug distributed deadlock
2310 * dump_holder - print information about a glock holder
2311 * @str: a string naming the type of holder
2312 * @gh: the glock holder
2314 * Returns: 0 on success, -ENOBUFS when we run out of space
2317 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2320 int error
= -ENOBUFS
;
2322 printk(KERN_INFO
" %s\n", str
);
2323 printk(KERN_INFO
" owner = %ld\n",
2324 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2325 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2326 printk(KERN_INFO
" gh_flags =");
2327 for (x
= 0; x
< 32; x
++)
2328 if (gh
->gh_flags
& (1 << x
))
2331 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2332 printk(KERN_INFO
" gh_iflags =");
2333 for (x
= 0; x
< 32; x
++)
2334 if (test_bit(x
, &gh
->gh_iflags
))
2344 * dump_inode - print information about an inode
2347 * Returns: 0 on success, -ENOBUFS when we run out of space
2350 static int dump_inode(struct gfs2_inode
*ip
)
2353 int error
= -ENOBUFS
;
2355 printk(KERN_INFO
" Inode:\n");
2356 printk(KERN_INFO
" num = %llu %llu\n",
2357 ip
->i_num
.no_formal_ino
, ip
->i_num
.no_addr
);
2358 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2359 printk(KERN_INFO
" i_count = %d\n", atomic_read(&ip
->i_count
));
2360 printk(KERN_INFO
" i_flags =");
2361 for (x
= 0; x
< 32; x
++)
2362 if (test_bit(x
, &ip
->i_flags
))
2365 printk(KERN_INFO
" vnode = %s\n", (ip
->i_vnode
) ? "yes" : "no");
2373 * dump_glock - print information about a glock
2375 * @count: where we are in the buffer
2377 * Returns: 0 on success, -ENOBUFS when we run out of space
2380 static int dump_glock(struct gfs2_glock
*gl
)
2382 struct gfs2_holder
*gh
;
2384 int error
= -ENOBUFS
;
2386 spin_lock(&gl
->gl_spin
);
2388 printk(KERN_INFO
"Glock (%u, %llu)\n",
2389 gl
->gl_name
.ln_type
,
2390 gl
->gl_name
.ln_number
);
2391 printk(KERN_INFO
" gl_flags =");
2392 for (x
= 0; x
< 32; x
++)
2393 if (test_bit(x
, &gl
->gl_flags
))
2396 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2397 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2398 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2399 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2400 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2401 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2402 printk(KERN_INFO
" le = %s\n",
2403 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2404 printk(KERN_INFO
" reclaim = %s\n",
2405 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2407 printk(KERN_INFO
" aspace = %lu\n",
2408 gl
->gl_aspace
->i_mapping
->nrpages
);
2410 printk(KERN_INFO
" aspace = no\n");
2411 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2412 if (gl
->gl_req_gh
) {
2413 error
= dump_holder("Request", gl
->gl_req_gh
);
2417 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2418 error
= dump_holder("Holder", gh
);
2422 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2423 error
= dump_holder("Waiter1", gh
);
2427 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2428 error
= dump_holder("Waiter2", gh
);
2432 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2433 error
= dump_holder("Waiter3", gh
);
2437 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2438 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2439 list_empty(&gl
->gl_holders
)) {
2440 error
= dump_inode(gl
->gl_object
);
2445 printk(KERN_INFO
" Inode: busy\n");
2452 spin_unlock(&gl
->gl_spin
);
2458 * gfs2_dump_lockstate - print out the current lockstate
2459 * @sdp: the filesystem
2460 * @ub: the buffer to copy the information into
2462 * If @ub is NULL, dump the lockstate to the console.
2466 int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2468 struct gfs2_gl_hash_bucket
*bucket
;
2469 struct gfs2_glock
*gl
;
2473 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2474 bucket
= &sdp
->sd_gl_hash
[x
];
2476 read_lock(&bucket
->hb_lock
);
2478 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2479 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2482 error
= dump_glock(gl
);
2487 read_unlock(&bucket
->hb_lock
);