2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License 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/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
);
49 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
50 static int dump_glock(struct gfs2_glock
*gl
);
53 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
54 * @actual: the current state of the lock
55 * @requested: the lock state that was requested by the caller
56 * @flags: the modifier flags passed in by the caller
58 * Returns: 1 if the locks are compatible, 0 otherwise
61 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
64 if (actual
== requested
)
70 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
73 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
80 * gl_hash() - Turn glock number into hash bucket number
81 * @lock: The glock number
83 * Returns: The number of the corresponding hash bucket
86 static unsigned int gl_hash(struct lm_lockname
*name
)
90 h
= jhash(&name
->ln_number
, sizeof(uint64_t), 0);
91 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
92 h
&= GFS2_GL_HASH_MASK
;
98 * glock_free() - Perform a few checks and then release struct gfs2_glock
99 * @gl: The glock to release
101 * Also calls lock module to release its internal structure for this glock.
105 static void glock_free(struct gfs2_glock
*gl
)
107 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
108 struct inode
*aspace
= gl
->gl_aspace
;
110 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
113 gfs2_aspace_put(aspace
);
115 kmem_cache_free(gfs2_glock_cachep
, gl
);
119 * gfs2_glock_hold() - increment reference count on glock
120 * @gl: The glock to hold
124 void gfs2_glock_hold(struct gfs2_glock
*gl
)
126 kref_get(&gl
->gl_ref
);
129 /* All work is done after the return from kref_put() so we
130 can release the write_lock before the free. */
132 static void kill_glock(struct kref
*kref
)
134 struct gfs2_glock
*gl
= container_of(kref
, struct gfs2_glock
, gl_ref
);
135 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
137 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
138 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
139 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
140 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
141 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
142 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
146 * gfs2_glock_put() - Decrement reference count on glock
147 * @gl: The glock to put
151 int gfs2_glock_put(struct gfs2_glock
*gl
)
153 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
154 struct gfs2_gl_hash_bucket
*bucket
= gl
->gl_bucket
;
157 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
159 write_lock(&bucket
->hb_lock
);
160 if (kref_put(&gl
->gl_ref
, kill_glock
)) {
161 list_del_init(&gl
->gl_list
);
162 write_unlock(&bucket
->hb_lock
);
163 BUG_ON(spin_is_locked(&gl
->gl_spin
));
168 write_unlock(&bucket
->hb_lock
);
170 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
175 * queue_empty - check to see if a glock's queue is empty
177 * @head: the head of the queue to check
179 * This function protects the list in the event that a process already
180 * has a holder on the list and is adding a second holder for itself.
181 * The glmutex lock is what generally prevents processes from working
182 * on the same glock at once, but the special case of adding a second
183 * holder for yourself ("recursive" locking) doesn't involve locking
184 * glmutex, making the spin lock necessary.
186 * Returns: 1 if the queue is empty
189 static inline int queue_empty(struct gfs2_glock
*gl
, struct list_head
*head
)
192 spin_lock(&gl
->gl_spin
);
193 empty
= list_empty(head
);
194 spin_unlock(&gl
->gl_spin
);
199 * search_bucket() - Find struct gfs2_glock by lock number
200 * @bucket: the bucket to search
201 * @name: The lock name
203 * Returns: NULL, or the struct gfs2_glock with the requested number
206 static struct gfs2_glock
*search_bucket(struct gfs2_gl_hash_bucket
*bucket
,
207 struct lm_lockname
*name
)
209 struct gfs2_glock
*gl
;
211 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
212 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
214 if (!lm_name_equal(&gl
->gl_name
, name
))
217 kref_get(&gl
->gl_ref
);
226 * gfs2_glock_find() - Find glock by lock number
227 * @sdp: The GFS2 superblock
228 * @name: The lock name
230 * Returns: NULL, or the struct gfs2_glock with the requested number
233 static struct gfs2_glock
*gfs2_glock_find(struct gfs2_sbd
*sdp
,
234 struct lm_lockname
*name
)
236 struct gfs2_gl_hash_bucket
*bucket
= &sdp
->sd_gl_hash
[gl_hash(name
)];
237 struct gfs2_glock
*gl
;
239 read_lock(&bucket
->hb_lock
);
240 gl
= search_bucket(bucket
, name
);
241 read_unlock(&bucket
->hb_lock
);
247 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
248 * @sdp: The GFS2 superblock
249 * @number: the lock number
250 * @glops: The glock_operations to use
251 * @create: If 0, don't create the glock if it doesn't exist
252 * @glp: the glock is returned here
254 * This does not lock a glock, just finds/creates structures for one.
259 int gfs2_glock_get(struct gfs2_sbd
*sdp
, uint64_t number
,
260 struct gfs2_glock_operations
*glops
, int create
,
261 struct gfs2_glock
**glp
)
263 struct lm_lockname name
;
264 struct gfs2_glock
*gl
, *tmp
;
265 struct gfs2_gl_hash_bucket
*bucket
;
268 name
.ln_number
= number
;
269 name
.ln_type
= glops
->go_type
;
270 bucket
= &sdp
->sd_gl_hash
[gl_hash(&name
)];
272 read_lock(&bucket
->hb_lock
);
273 gl
= search_bucket(bucket
, &name
);
274 read_unlock(&bucket
->hb_lock
);
281 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
285 memset(gl
, 0, sizeof(struct gfs2_glock
));
287 INIT_LIST_HEAD(&gl
->gl_list
);
289 kref_init(&gl
->gl_ref
);
291 spin_lock_init(&gl
->gl_spin
);
293 gl
->gl_state
= LM_ST_UNLOCKED
;
296 INIT_LIST_HEAD(&gl
->gl_holders
);
297 INIT_LIST_HEAD(&gl
->gl_waiters1
);
298 INIT_LIST_HEAD(&gl
->gl_waiters2
);
299 INIT_LIST_HEAD(&gl
->gl_waiters3
);
303 gl
->gl_bucket
= bucket
;
304 INIT_LIST_HEAD(&gl
->gl_reclaim
);
308 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
309 INIT_LIST_HEAD(&gl
->gl_ail_list
);
311 /* If this glock protects actual on-disk data or metadata blocks,
312 create a VFS inode to manage the pages/buffers holding them. */
313 if (glops
== &gfs2_inode_glops
||
314 glops
== &gfs2_rgrp_glops
||
315 glops
== &gfs2_meta_glops
) {
316 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
317 if (!gl
->gl_aspace
) {
323 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
327 write_lock(&bucket
->hb_lock
);
328 tmp
= search_bucket(bucket
, &name
);
330 write_unlock(&bucket
->hb_lock
);
334 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
335 write_unlock(&bucket
->hb_lock
);
344 gfs2_aspace_put(gl
->gl_aspace
);
347 kmem_cache_free(gfs2_glock_cachep
, gl
);
353 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
355 * @state: the state we're requesting
356 * @flags: the modifier flags
357 * @gh: the holder structure
361 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
362 struct gfs2_holder
*gh
)
364 INIT_LIST_HEAD(&gh
->gh_list
);
366 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
367 gh
->gh_owner
= current
;
368 gh
->gh_state
= state
;
369 gh
->gh_flags
= flags
;
372 init_completion(&gh
->gh_wait
);
374 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
375 gh
->gh_flags
|= GL_LOCAL_EXCL
;
381 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
382 * @state: the state we're requesting
383 * @flags: the modifier flags
384 * @gh: the holder structure
386 * Don't mess with the glock.
390 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
392 gh
->gh_state
= state
;
393 gh
->gh_flags
= flags
;
394 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
395 gh
->gh_flags
|= GL_LOCAL_EXCL
;
397 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
398 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
402 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
403 * @gh: the holder structure
407 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
409 gfs2_glock_put(gh
->gh_gl
);
415 * gfs2_holder_get - get a struct gfs2_holder structure
417 * @state: the state we're requesting
418 * @flags: the modifier flags
419 * @gfp_flags: __GFP_NOFAIL
421 * Figure out how big an impact this function has. Either:
422 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
423 * 2) Leave it like it is
425 * Returns: the holder structure, NULL on ENOMEM
428 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
430 int flags
, gfp_t gfp_flags
)
432 struct gfs2_holder
*gh
;
434 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
438 gfs2_holder_init(gl
, state
, flags
, gh
);
439 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
440 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
445 * gfs2_holder_put - get rid of a struct gfs2_holder structure
446 * @gh: the holder structure
450 static void gfs2_holder_put(struct gfs2_holder
*gh
)
452 gfs2_holder_uninit(gh
);
457 * rq_mutex - process a mutex request in the queue
458 * @gh: the glock holder
460 * Returns: 1 if the queue is blocked
463 static int rq_mutex(struct gfs2_holder
*gh
)
465 struct gfs2_glock
*gl
= gh
->gh_gl
;
467 list_del_init(&gh
->gh_list
);
468 /* gh->gh_error never examined. */
469 set_bit(GLF_LOCK
, &gl
->gl_flags
);
470 complete(&gh
->gh_wait
);
476 * rq_promote - process a promote request in the queue
477 * @gh: the glock holder
479 * Acquire a new inter-node lock, or change a lock state to more restrictive.
481 * Returns: 1 if the queue is blocked
484 static int rq_promote(struct gfs2_holder
*gh
)
486 struct gfs2_glock
*gl
= gh
->gh_gl
;
487 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
488 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
490 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
491 if (list_empty(&gl
->gl_holders
)) {
493 set_bit(GLF_LOCK
, &gl
->gl_flags
);
494 spin_unlock(&gl
->gl_spin
);
496 if (atomic_read(&sdp
->sd_reclaim_count
) >
497 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
498 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
499 gfs2_reclaim_glock(sdp
);
500 gfs2_reclaim_glock(sdp
);
503 glops
->go_xmote_th(gl
, gh
->gh_state
,
506 spin_lock(&gl
->gl_spin
);
511 if (list_empty(&gl
->gl_holders
)) {
512 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
513 set_bit(GLF_LOCK
, &gl
->gl_flags
);
515 struct gfs2_holder
*next_gh
;
516 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
518 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
520 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
524 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
526 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
528 complete(&gh
->gh_wait
);
534 * rq_demote - process a demote request in the queue
535 * @gh: the glock holder
537 * Returns: 1 if the queue is blocked
540 static int rq_demote(struct gfs2_holder
*gh
)
542 struct gfs2_glock
*gl
= gh
->gh_gl
;
543 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
545 if (!list_empty(&gl
->gl_holders
))
548 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
549 list_del_init(&gh
->gh_list
);
551 spin_unlock(&gl
->gl_spin
);
552 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
555 complete(&gh
->gh_wait
);
556 spin_lock(&gl
->gl_spin
);
559 set_bit(GLF_LOCK
, &gl
->gl_flags
);
560 spin_unlock(&gl
->gl_spin
);
562 if (gh
->gh_state
== LM_ST_UNLOCKED
||
563 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
564 glops
->go_drop_th(gl
);
566 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
568 spin_lock(&gl
->gl_spin
);
575 * rq_greedy - process a queued request to drop greedy status
576 * @gh: the glock holder
578 * Returns: 1 if the queue is blocked
581 static int rq_greedy(struct gfs2_holder
*gh
)
583 struct gfs2_glock
*gl
= gh
->gh_gl
;
585 list_del_init(&gh
->gh_list
);
586 /* gh->gh_error never examined. */
587 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
588 spin_unlock(&gl
->gl_spin
);
590 gfs2_holder_uninit(gh
);
591 kfree(container_of(gh
, struct greedy
, gr_gh
));
593 spin_lock(&gl
->gl_spin
);
599 * run_queue - process holder structures on a glock
603 static void run_queue(struct gfs2_glock
*gl
)
605 struct gfs2_holder
*gh
;
609 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
612 if (!list_empty(&gl
->gl_waiters1
)) {
613 gh
= list_entry(gl
->gl_waiters1
.next
,
614 struct gfs2_holder
, gh_list
);
616 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
617 blocked
= rq_mutex(gh
);
619 gfs2_assert_warn(gl
->gl_sbd
, 0);
621 } else if (!list_empty(&gl
->gl_waiters2
) &&
622 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
623 gh
= list_entry(gl
->gl_waiters2
.next
,
624 struct gfs2_holder
, gh_list
);
626 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
627 blocked
= rq_demote(gh
);
628 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
629 blocked
= rq_greedy(gh
);
631 gfs2_assert_warn(gl
->gl_sbd
, 0);
633 } else if (!list_empty(&gl
->gl_waiters3
)) {
634 gh
= list_entry(gl
->gl_waiters3
.next
,
635 struct gfs2_holder
, gh_list
);
637 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
638 blocked
= rq_promote(gh
);
640 gfs2_assert_warn(gl
->gl_sbd
, 0);
651 * gfs2_glmutex_lock - acquire a local lock on a glock
654 * Gives caller exclusive access to manipulate a glock structure.
657 void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
659 struct gfs2_holder gh
;
661 gfs2_holder_init(gl
, 0, 0, &gh
);
662 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
664 spin_lock(&gl
->gl_spin
);
665 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
666 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
668 gl
->gl_owner
= current
;
669 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
670 complete(&gh
.gh_wait
);
672 spin_unlock(&gl
->gl_spin
);
674 wait_for_completion(&gh
.gh_wait
);
675 gfs2_holder_uninit(&gh
);
679 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
682 * Returns: 1 if the glock is acquired
685 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
689 spin_lock(&gl
->gl_spin
);
690 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
693 gl
->gl_owner
= current
;
694 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
696 spin_unlock(&gl
->gl_spin
);
702 * gfs2_glmutex_unlock - release a local lock on a glock
707 void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
709 spin_lock(&gl
->gl_spin
);
710 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
714 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
715 spin_unlock(&gl
->gl_spin
);
719 * handle_callback - add a demote request to a lock's queue
721 * @state: the state the caller wants us to change to
725 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
727 struct gfs2_holder
*gh
, *new_gh
= NULL
;
730 spin_lock(&gl
->gl_spin
);
732 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
733 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
734 gl
->gl_req_gh
!= gh
) {
735 if (gh
->gh_state
!= state
)
736 gh
->gh_state
= LM_ST_UNLOCKED
;
742 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
745 spin_unlock(&gl
->gl_spin
);
747 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
,
748 GFP_KERNEL
| __GFP_NOFAIL
),
749 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
750 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
756 spin_unlock(&gl
->gl_spin
);
759 gfs2_holder_put(new_gh
);
763 * state_change - record that the glock is now in a different state
765 * @new_state the new state
769 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
773 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
774 held2
= (new_state
!= LM_ST_UNLOCKED
);
776 if (held1
!= held2
) {
783 gl
->gl_state
= new_state
;
787 * xmote_bh - Called after the lock module is done acquiring a lock
788 * @gl: The glock in question
789 * @ret: the int returned from the lock module
793 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
795 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
796 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
797 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
798 int prev_state
= gl
->gl_state
;
801 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
802 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
803 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
805 state_change(gl
, ret
& LM_OUT_ST_MASK
);
807 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
809 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
810 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
811 /* We might not want to do this here.
812 Look at moving to the inode glops. */
814 glops
->go_inval(gl
, DIO_DATA
);
817 /* Deal with each possible exit condition */
820 gl
->gl_stamp
= jiffies
;
822 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
823 spin_lock(&gl
->gl_spin
);
824 list_del_init(&gh
->gh_list
);
826 spin_unlock(&gl
->gl_spin
);
828 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
829 spin_lock(&gl
->gl_spin
);
830 list_del_init(&gh
->gh_list
);
831 if (gl
->gl_state
== gh
->gh_state
||
832 gl
->gl_state
== LM_ST_UNLOCKED
)
835 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
836 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
837 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
838 gh
->gh_error
= GLR_TRYFAILED
;
840 spin_unlock(&gl
->gl_spin
);
842 if (ret
& LM_OUT_CANCELED
)
843 handle_callback(gl
, LM_ST_UNLOCKED
); /* Lame */
845 } else if (ret
& LM_OUT_CANCELED
) {
846 spin_lock(&gl
->gl_spin
);
847 list_del_init(&gh
->gh_list
);
848 gh
->gh_error
= GLR_CANCELED
;
849 spin_unlock(&gl
->gl_spin
);
851 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
852 spin_lock(&gl
->gl_spin
);
853 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
855 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
856 spin_unlock(&gl
->gl_spin
);
858 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
862 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
863 spin_lock(&gl
->gl_spin
);
864 list_del_init(&gh
->gh_list
);
865 gh
->gh_error
= GLR_TRYFAILED
;
866 spin_unlock(&gl
->gl_spin
);
869 if (gfs2_assert_withdraw(sdp
, 0) == -1)
870 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
873 if (glops
->go_xmote_bh
)
874 glops
->go_xmote_bh(gl
);
877 spin_lock(&gl
->gl_spin
);
878 gl
->gl_req_gh
= NULL
;
879 gl
->gl_req_bh
= NULL
;
880 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
882 spin_unlock(&gl
->gl_spin
);
888 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
891 complete(&gh
->gh_wait
);
896 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
897 * @gl: The glock in question
898 * @state: the requested state
899 * @flags: modifier flags to the lock call
903 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
905 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
906 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
907 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
908 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
910 unsigned int lck_ret
;
912 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
913 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
914 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
915 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
917 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
920 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
924 gl
->gl_req_bh
= xmote_bh
;
926 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
,
929 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
932 if (lck_ret
& LM_OUT_ASYNC
)
933 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
935 xmote_bh(gl
, lck_ret
);
939 * drop_bh - Called after a lock module unlock completes
941 * @ret: the return status
943 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
944 * Doesn't drop the reference on the glock the top half took out
948 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
950 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
951 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
952 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
954 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
956 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
957 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
958 gfs2_assert_warn(sdp
, !ret
);
960 state_change(gl
, LM_ST_UNLOCKED
);
963 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
966 spin_lock(&gl
->gl_spin
);
967 list_del_init(&gh
->gh_list
);
969 spin_unlock(&gl
->gl_spin
);
972 if (glops
->go_drop_bh
)
973 glops
->go_drop_bh(gl
);
975 spin_lock(&gl
->gl_spin
);
976 gl
->gl_req_gh
= NULL
;
977 gl
->gl_req_bh
= NULL
;
978 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
980 spin_unlock(&gl
->gl_spin
);
985 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
988 complete(&gh
->gh_wait
);
993 * gfs2_glock_drop_th - call into the lock module to unlock a lock
998 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
1000 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1001 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1004 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1005 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1006 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1008 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1011 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1014 gfs2_glock_hold(gl
);
1015 gl
->gl_req_bh
= drop_bh
;
1017 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1019 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1025 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1029 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1030 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1032 * Don't cancel GL_NOCANCEL requests.
1035 static void do_cancels(struct gfs2_holder
*gh
)
1037 struct gfs2_glock
*gl
= gh
->gh_gl
;
1039 spin_lock(&gl
->gl_spin
);
1041 while (gl
->gl_req_gh
!= gh
&&
1042 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1043 !list_empty(&gh
->gh_list
)) {
1044 if (gl
->gl_req_bh
&&
1046 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1047 spin_unlock(&gl
->gl_spin
);
1048 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1050 spin_lock(&gl
->gl_spin
);
1052 spin_unlock(&gl
->gl_spin
);
1054 spin_lock(&gl
->gl_spin
);
1058 spin_unlock(&gl
->gl_spin
);
1062 * glock_wait_internal - wait on a glock acquisition
1063 * @gh: the glock holder
1065 * Returns: 0 on success
1068 static int glock_wait_internal(struct gfs2_holder
*gh
)
1070 struct gfs2_glock
*gl
= gh
->gh_gl
;
1071 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1072 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1074 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1077 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1078 spin_lock(&gl
->gl_spin
);
1079 if (gl
->gl_req_gh
!= gh
&&
1080 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1081 !list_empty(&gh
->gh_list
)) {
1082 list_del_init(&gh
->gh_list
);
1083 gh
->gh_error
= GLR_TRYFAILED
;
1085 spin_unlock(&gl
->gl_spin
);
1086 return gh
->gh_error
;
1088 spin_unlock(&gl
->gl_spin
);
1091 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1094 wait_for_completion(&gh
->gh_wait
);
1097 return gh
->gh_error
;
1099 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1100 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1104 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1105 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1107 if (glops
->go_lock
) {
1108 gh
->gh_error
= glops
->go_lock(gh
);
1110 spin_lock(&gl
->gl_spin
);
1111 list_del_init(&gh
->gh_list
);
1112 spin_unlock(&gl
->gl_spin
);
1116 spin_lock(&gl
->gl_spin
);
1117 gl
->gl_req_gh
= NULL
;
1118 gl
->gl_req_bh
= NULL
;
1119 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1121 spin_unlock(&gl
->gl_spin
);
1124 return gh
->gh_error
;
1127 static inline struct gfs2_holder
*
1128 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1130 struct gfs2_holder
*gh
;
1132 list_for_each_entry(gh
, head
, gh_list
) {
1133 if (gh
->gh_owner
== owner
)
1141 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1142 * @gh: the holder structure to add
1146 static void add_to_queue(struct gfs2_holder
*gh
)
1148 struct gfs2_glock
*gl
= gh
->gh_gl
;
1149 struct gfs2_holder
*existing
;
1151 BUG_ON(!gh
->gh_owner
);
1153 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1155 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1156 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1160 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1162 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1163 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1167 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1168 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1170 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1174 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1175 * @gh: the holder structure
1177 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1179 * Returns: 0, GLR_TRYFAILED, or errno on failure
1182 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1184 struct gfs2_glock
*gl
= gh
->gh_gl
;
1185 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1189 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1190 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1194 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1196 spin_lock(&gl
->gl_spin
);
1199 spin_unlock(&gl
->gl_spin
);
1201 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1202 error
= glock_wait_internal(gh
);
1203 if (error
== GLR_CANCELED
) {
1209 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1211 if (error
== GLR_TRYFAILED
&& (gh
->gh_flags
& GL_DUMP
))
1218 * gfs2_glock_poll - poll to see if an async request has been completed
1221 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1224 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1226 struct gfs2_glock
*gl
= gh
->gh_gl
;
1229 spin_lock(&gl
->gl_spin
);
1231 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1233 else if (list_empty(&gh
->gh_list
)) {
1234 if (gh
->gh_error
== GLR_CANCELED
) {
1235 spin_unlock(&gl
->gl_spin
);
1237 if (gfs2_glock_nq(gh
))
1244 spin_unlock(&gl
->gl_spin
);
1250 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1251 * @gh: the holder structure
1253 * Returns: 0, GLR_TRYFAILED, or errno on failure
1256 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1260 error
= glock_wait_internal(gh
);
1261 if (error
== GLR_CANCELED
) {
1263 gh
->gh_flags
&= ~GL_ASYNC
;
1264 error
= gfs2_glock_nq(gh
);
1271 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1272 * @gh: the glock holder
1276 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1278 struct gfs2_glock
*gl
= gh
->gh_gl
;
1279 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1281 if (gh
->gh_flags
& GL_SYNC
)
1282 set_bit(GLF_SYNC
, &gl
->gl_flags
);
1284 if (gh
->gh_flags
& GL_NOCACHE
)
1285 handle_callback(gl
, LM_ST_UNLOCKED
);
1287 gfs2_glmutex_lock(gl
);
1289 spin_lock(&gl
->gl_spin
);
1290 list_del_init(&gh
->gh_list
);
1292 if (list_empty(&gl
->gl_holders
)) {
1293 spin_unlock(&gl
->gl_spin
);
1295 if (glops
->go_unlock
)
1296 glops
->go_unlock(gh
);
1298 if (test_bit(GLF_SYNC
, &gl
->gl_flags
)) {
1300 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
);
1303 gl
->gl_stamp
= jiffies
;
1305 spin_lock(&gl
->gl_spin
);
1308 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1310 spin_unlock(&gl
->gl_spin
);
1314 * gfs2_glock_prefetch - Try to prefetch a glock
1316 * @state: the state to prefetch in
1317 * @flags: flags passed to go_xmote_th()
1321 static void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
,
1324 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1326 spin_lock(&gl
->gl_spin
);
1328 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1329 !list_empty(&gl
->gl_holders
) ||
1330 !list_empty(&gl
->gl_waiters1
) ||
1331 !list_empty(&gl
->gl_waiters2
) ||
1332 !list_empty(&gl
->gl_waiters3
) ||
1333 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1334 spin_unlock(&gl
->gl_spin
);
1338 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1339 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1340 spin_unlock(&gl
->gl_spin
);
1342 glops
->go_xmote_th(gl
, state
, flags
);
1345 static void greedy_work(void *data
)
1347 struct greedy
*gr
= data
;
1348 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1349 struct gfs2_glock
*gl
= gh
->gh_gl
;
1350 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1352 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1354 if (glops
->go_greedy
)
1355 glops
->go_greedy(gl
);
1357 spin_lock(&gl
->gl_spin
);
1359 if (list_empty(&gl
->gl_waiters2
)) {
1360 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1361 spin_unlock(&gl
->gl_spin
);
1362 gfs2_holder_uninit(gh
);
1365 gfs2_glock_hold(gl
);
1366 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1368 spin_unlock(&gl
->gl_spin
);
1374 * gfs2_glock_be_greedy -
1378 * Returns: 0 if go_greedy will be called, 1 otherwise
1381 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1384 struct gfs2_holder
*gh
;
1387 gl
->gl_sbd
->sd_args
.ar_localcaching
||
1388 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1391 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1393 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1398 gfs2_holder_init(gl
, 0, 0, gh
);
1399 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1400 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1402 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1403 schedule_delayed_work(&gr
->gr_work
, time
);
1409 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1410 * @gh: the holder structure
1414 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1417 gfs2_holder_uninit(gh
);
1421 * gfs2_glock_nq_num - acquire a glock based on lock number
1422 * @sdp: the filesystem
1423 * @number: the lock number
1424 * @glops: the glock operations for the type of glock
1425 * @state: the state to acquire the glock in
1426 * @flags: modifier flags for the aquisition
1427 * @gh: the struct gfs2_holder
1432 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1433 struct gfs2_glock_operations
*glops
, unsigned int state
,
1434 int flags
, struct gfs2_holder
*gh
)
1436 struct gfs2_glock
*gl
;
1439 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1441 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1449 * glock_compare - Compare two struct gfs2_glock structures for sorting
1450 * @arg_a: the first structure
1451 * @arg_b: the second structure
1455 static int glock_compare(const void *arg_a
, const void *arg_b
)
1457 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1458 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1459 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1460 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1463 if (a
->ln_number
> b
->ln_number
)
1465 else if (a
->ln_number
< b
->ln_number
)
1468 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1469 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1471 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1472 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1480 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1481 * @num_gh: the number of structures
1482 * @ghs: an array of struct gfs2_holder structures
1484 * Returns: 0 on success (all glocks acquired),
1485 * errno on failure (no glocks acquired)
1488 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1489 struct gfs2_holder
**p
)
1494 for (x
= 0; x
< num_gh
; x
++)
1497 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1499 for (x
= 0; x
< num_gh
; x
++) {
1500 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1502 error
= gfs2_glock_nq(p
[x
]);
1505 gfs2_glock_dq(p
[x
]);
1514 * gfs2_glock_nq_m - acquire multiple glocks
1515 * @num_gh: the number of structures
1516 * @ghs: an array of struct gfs2_holder structures
1518 * Figure out how big an impact this function has. Either:
1519 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1520 * 2) Forget async stuff and just call nq_m_sync()
1521 * 3) Leave it like it is
1523 * Returns: 0 on success (all glocks acquired),
1524 * errno on failure (no glocks acquired)
1527 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1531 int borked
= 0, serious
= 0;
1538 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1539 return gfs2_glock_nq(ghs
);
1542 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1546 for (x
= 0; x
< num_gh
; x
++) {
1547 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1548 error
= gfs2_glock_nq(&ghs
[x
]);
1557 for (x
= 0; x
< num_gh
; x
++) {
1558 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1561 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1571 for (x
= 0; x
< num_gh
; x
++)
1573 gfs2_glock_dq(&ghs
[x
]);
1578 for (x
= 0; x
< num_gh
; x
++)
1579 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1581 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1590 * gfs2_glock_dq_m - release multiple glocks
1591 * @num_gh: the number of structures
1592 * @ghs: an array of struct gfs2_holder structures
1596 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1600 for (x
= 0; x
< num_gh
; x
++)
1601 gfs2_glock_dq(&ghs
[x
]);
1605 * gfs2_glock_dq_uninit_m - release multiple glocks
1606 * @num_gh: the number of structures
1607 * @ghs: an array of struct gfs2_holder structures
1611 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1615 for (x
= 0; x
< num_gh
; x
++)
1616 gfs2_glock_dq_uninit(&ghs
[x
]);
1620 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1621 * @sdp: the filesystem
1622 * @number: the lock number
1623 * @glops: the glock operations for the type of glock
1624 * @state: the state to acquire the glock in
1625 * @flags: modifier flags for the aquisition
1630 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1631 struct gfs2_glock_operations
*glops
,
1632 unsigned int state
, int flags
)
1634 struct gfs2_glock
*gl
;
1637 if (atomic_read(&sdp
->sd_reclaim_count
) <
1638 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1639 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1641 gfs2_glock_prefetch(gl
, state
, flags
);
1648 * gfs2_lvb_hold - attach a LVB from a glock
1649 * @gl: The glock in question
1653 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1657 gfs2_glmutex_lock(gl
);
1659 if (!atomic_read(&gl
->gl_lvb_count
)) {
1660 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1662 gfs2_glmutex_unlock(gl
);
1665 gfs2_glock_hold(gl
);
1667 atomic_inc(&gl
->gl_lvb_count
);
1669 gfs2_glmutex_unlock(gl
);
1675 * gfs2_lvb_unhold - detach a LVB from a glock
1676 * @gl: The glock in question
1680 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1682 gfs2_glock_hold(gl
);
1683 gfs2_glmutex_lock(gl
);
1685 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1686 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1687 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1692 gfs2_glmutex_unlock(gl
);
1697 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1699 gfs2_glmutex_lock(gl
);
1701 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1702 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1703 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1705 gfs2_glmutex_unlock(gl
);
1709 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1712 struct gfs2_glock
*gl
;
1714 gl
= gfs2_glock_find(sdp
, name
);
1718 if (gl
->gl_ops
->go_callback
)
1719 gl
->gl_ops
->go_callback(gl
, state
);
1720 handle_callback(gl
, state
);
1722 spin_lock(&gl
->gl_spin
);
1724 spin_unlock(&gl
->gl_spin
);
1730 * gfs2_glock_cb - Callback used by locking module
1731 * @fsdata: Pointer to the superblock
1732 * @type: Type of callback
1733 * @data: Type dependent data pointer
1735 * Called by the locking module when it wants to tell us something.
1736 * Either we need to drop a lock, one of our ASYNC requests completed, or
1737 * a journal from another client needs to be recovered.
1740 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1742 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1746 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1750 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1754 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1758 struct lm_async_cb
*async
= data
;
1759 struct gfs2_glock
*gl
;
1761 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1762 if (gfs2_assert_warn(sdp
, gl
))
1764 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1765 gl
->gl_req_bh(gl
, async
->lc_ret
);
1770 case LM_CB_NEED_RECOVERY
:
1771 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1772 if (sdp
->sd_recoverd_process
)
1773 wake_up_process(sdp
->sd_recoverd_process
);
1776 case LM_CB_DROPLOCKS
:
1777 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1778 gfs2_quota_scan(sdp
);
1782 gfs2_assert_warn(sdp
, 0);
1788 * gfs2_try_toss_inode - try to remove a particular inode struct from cache
1789 * sdp: the filesystem
1790 * inum: the inode number
1794 void gfs2_try_toss_inode(struct gfs2_sbd
*sdp
, struct gfs2_inum
*inum
)
1796 struct gfs2_glock
*gl
;
1797 struct gfs2_inode
*ip
;
1800 error
= gfs2_glock_get(sdp
, inum
->no_addr
, &gfs2_inode_glops
,
1805 if (!gfs2_glmutex_trylock(gl
))
1812 if (atomic_read(&ip
->i_count
))
1815 gfs2_inode_destroy(ip
, 1);
1818 gfs2_glmutex_unlock(gl
);
1825 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1826 * iopen glock from memory
1827 * @io_gl: the iopen glock
1828 * @state: the state into which the glock should be put
1832 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1834 struct gfs2_glock
*i_gl
;
1836 if (state
!= LM_ST_UNLOCKED
)
1839 spin_lock(&io_gl
->gl_spin
);
1840 i_gl
= io_gl
->gl_object
;
1842 gfs2_glock_hold(i_gl
);
1843 spin_unlock(&io_gl
->gl_spin
);
1845 spin_unlock(&io_gl
->gl_spin
);
1849 if (gfs2_glmutex_trylock(i_gl
)) {
1850 struct gfs2_inode
*ip
= i_gl
->gl_object
;
1852 gfs2_try_toss_vnode(ip
);
1853 gfs2_glmutex_unlock(i_gl
);
1854 gfs2_glock_schedule_for_reclaim(i_gl
);
1857 gfs2_glmutex_unlock(i_gl
);
1861 gfs2_glock_put(i_gl
);
1865 * demote_ok - Check to see if it's ok to unlock a glock
1868 * Returns: 1 if it's ok
1871 static int demote_ok(struct gfs2_glock
*gl
)
1873 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1874 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1877 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1879 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
1880 demote
= time_after_eq(jiffies
,
1882 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
1883 else if (glops
->go_demote_ok
)
1884 demote
= glops
->go_demote_ok(gl
);
1890 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1895 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1897 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1899 spin_lock(&sdp
->sd_reclaim_lock
);
1900 if (list_empty(&gl
->gl_reclaim
)) {
1901 gfs2_glock_hold(gl
);
1902 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1903 atomic_inc(&sdp
->sd_reclaim_count
);
1905 spin_unlock(&sdp
->sd_reclaim_lock
);
1907 wake_up(&sdp
->sd_reclaim_wq
);
1911 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1912 * @sdp: the filesystem
1914 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1915 * different glock and we notice that there are a lot of glocks in the
1920 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1922 struct gfs2_glock
*gl
;
1924 spin_lock(&sdp
->sd_reclaim_lock
);
1925 if (list_empty(&sdp
->sd_reclaim_list
)) {
1926 spin_unlock(&sdp
->sd_reclaim_lock
);
1929 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1930 struct gfs2_glock
, gl_reclaim
);
1931 list_del_init(&gl
->gl_reclaim
);
1932 spin_unlock(&sdp
->sd_reclaim_lock
);
1934 atomic_dec(&sdp
->sd_reclaim_count
);
1935 atomic_inc(&sdp
->sd_reclaimed
);
1937 if (gfs2_glmutex_trylock(gl
)) {
1938 if (gl
->gl_ops
== &gfs2_inode_glops
) {
1939 struct gfs2_inode
*ip
= gl
->gl_object
;
1940 if (ip
&& !atomic_read(&ip
->i_count
))
1941 gfs2_inode_destroy(ip
, 1);
1943 if (queue_empty(gl
, &gl
->gl_holders
) &&
1944 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1946 handle_callback(gl
, LM_ST_UNLOCKED
);
1947 gfs2_glmutex_unlock(gl
);
1954 * examine_bucket - Call a function for glock in a hash bucket
1955 * @examiner: the function
1956 * @sdp: the filesystem
1957 * @bucket: the bucket
1959 * Returns: 1 if the bucket has entries
1962 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1963 struct gfs2_gl_hash_bucket
*bucket
)
1965 struct glock_plug plug
;
1966 struct list_head
*tmp
;
1967 struct gfs2_glock
*gl
;
1970 /* Add "plug" to end of bucket list, work back up list from there */
1971 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
1972 set_bit(GLF_PLUG
, &plug
.gl_flags
);
1974 write_lock(&bucket
->hb_lock
);
1975 list_add(&plug
.gl_list
, &bucket
->hb_list
);
1976 write_unlock(&bucket
->hb_lock
);
1979 write_lock(&bucket
->hb_lock
);
1982 tmp
= plug
.gl_list
.next
;
1984 if (tmp
== &bucket
->hb_list
) {
1985 list_del(&plug
.gl_list
);
1986 entries
= !list_empty(&bucket
->hb_list
);
1987 write_unlock(&bucket
->hb_lock
);
1990 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
1992 /* Move plug up list */
1993 list_move(&plug
.gl_list
, &gl
->gl_list
);
1995 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
1998 /* examiner() must glock_put() */
1999 gfs2_glock_hold(gl
);
2004 write_unlock(&bucket
->hb_lock
);
2011 * scan_glock - look at a glock and see if we can reclaim it
2012 * @gl: the glock to look at
2016 static void scan_glock(struct gfs2_glock
*gl
)
2018 if (gfs2_glmutex_trylock(gl
)) {
2019 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2020 struct gfs2_inode
*ip
= gl
->gl_object
;
2021 if (ip
&& !atomic_read(&ip
->i_count
))
2024 if (queue_empty(gl
, &gl
->gl_holders
) &&
2025 gl
->gl_state
!= LM_ST_UNLOCKED
&&
2029 gfs2_glmutex_unlock(gl
);
2037 gfs2_glmutex_unlock(gl
);
2038 gfs2_glock_schedule_for_reclaim(gl
);
2043 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
2044 * @sdp: the filesystem
2048 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
2052 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2053 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
2059 * clear_glock - look at a glock and see if we can free it from glock cache
2060 * @gl: the glock to look at
2064 static void clear_glock(struct gfs2_glock
*gl
)
2066 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2069 spin_lock(&sdp
->sd_reclaim_lock
);
2070 if (!list_empty(&gl
->gl_reclaim
)) {
2071 list_del_init(&gl
->gl_reclaim
);
2072 atomic_dec(&sdp
->sd_reclaim_count
);
2073 spin_unlock(&sdp
->sd_reclaim_lock
);
2074 released
= gfs2_glock_put(gl
);
2075 gfs2_assert(sdp
, !released
);
2077 spin_unlock(&sdp
->sd_reclaim_lock
);
2080 if (gfs2_glmutex_trylock(gl
)) {
2081 if (gl
->gl_ops
== &gfs2_inode_glops
) {
2082 struct gfs2_inode
*ip
= gl
->gl_object
;
2083 if (ip
&& !atomic_read(&ip
->i_count
))
2084 gfs2_inode_destroy(ip
, 1);
2086 if (queue_empty(gl
, &gl
->gl_holders
) &&
2087 gl
->gl_state
!= LM_ST_UNLOCKED
)
2088 handle_callback(gl
, LM_ST_UNLOCKED
);
2090 gfs2_glmutex_unlock(gl
);
2097 * gfs2_gl_hash_clear - Empty out the glock hash table
2098 * @sdp: the filesystem
2099 * @wait: wait until it's all gone
2101 * Called when unmounting the filesystem, or when inter-node lock manager
2102 * requests DROPLOCKS because it is running out of capacity.
2105 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2116 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2117 if (examine_bucket(clear_glock
, sdp
,
2118 &sdp
->sd_gl_hash
[x
]))
2124 if (time_after_eq(jiffies
,
2125 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2126 fs_warn(sdp
, "Unmount seems to be stalled. "
2127 "Dumping lock state...\n");
2128 gfs2_dump_lockstate(sdp
);
2132 /* invalidate_inodes() requires that the sb inodes list
2133 not change, but an async completion callback for an
2134 unlock can occur which does glock_put() which
2135 can call iput() which will change the sb inodes list.
2136 invalidate_inodes_mutex prevents glock_put()'s during
2137 an invalidate_inodes() */
2139 mutex_lock(&sdp
->sd_invalidate_inodes_mutex
);
2140 invalidate_inodes(sdp
->sd_vfs
);
2141 mutex_unlock(&sdp
->sd_invalidate_inodes_mutex
);
2147 * Diagnostic routines to help debug distributed deadlock
2151 * dump_holder - print information about a glock holder
2152 * @str: a string naming the type of holder
2153 * @gh: the glock holder
2155 * Returns: 0 on success, -ENOBUFS when we run out of space
2158 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2161 int error
= -ENOBUFS
;
2163 printk(KERN_INFO
" %s\n", str
);
2164 printk(KERN_INFO
" owner = %ld\n",
2165 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2166 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2167 printk(KERN_INFO
" gh_flags =");
2168 for (x
= 0; x
< 32; x
++)
2169 if (gh
->gh_flags
& (1 << x
))
2172 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2173 printk(KERN_INFO
" gh_iflags =");
2174 for (x
= 0; x
< 32; x
++)
2175 if (test_bit(x
, &gh
->gh_iflags
))
2178 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2186 * dump_inode - print information about an inode
2189 * Returns: 0 on success, -ENOBUFS when we run out of space
2192 static int dump_inode(struct gfs2_inode
*ip
)
2195 int error
= -ENOBUFS
;
2197 printk(KERN_INFO
" Inode:\n");
2198 printk(KERN_INFO
" num = %llu %llu\n",
2199 (unsigned long long)ip
->i_num
.no_formal_ino
,
2200 (unsigned long long)ip
->i_num
.no_addr
);
2201 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2202 printk(KERN_INFO
" i_count = %d\n", atomic_read(&ip
->i_count
));
2203 printk(KERN_INFO
" i_flags =");
2204 for (x
= 0; x
< 32; x
++)
2205 if (test_bit(x
, &ip
->i_flags
))
2208 printk(KERN_INFO
" vnode = %s\n", (ip
->i_vnode
) ? "yes" : "no");
2216 * dump_glock - print information about a glock
2218 * @count: where we are in the buffer
2220 * Returns: 0 on success, -ENOBUFS when we run out of space
2223 static int dump_glock(struct gfs2_glock
*gl
)
2225 struct gfs2_holder
*gh
;
2227 int error
= -ENOBUFS
;
2229 spin_lock(&gl
->gl_spin
);
2231 printk(KERN_INFO
"Glock (%u, %llu)\n", gl
->gl_name
.ln_type
,
2232 (unsigned long long)gl
->gl_name
.ln_number
);
2233 printk(KERN_INFO
" gl_flags =");
2234 for (x
= 0; x
< 32; x
++)
2235 if (test_bit(x
, &gl
->gl_flags
))
2238 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2239 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2240 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
2241 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
2242 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2243 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2244 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2245 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2246 printk(KERN_INFO
" le = %s\n",
2247 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2248 printk(KERN_INFO
" reclaim = %s\n",
2249 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2251 printk(KERN_INFO
" aspace = %lu\n",
2252 gl
->gl_aspace
->i_mapping
->nrpages
);
2254 printk(KERN_INFO
" aspace = no\n");
2255 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2256 if (gl
->gl_req_gh
) {
2257 error
= dump_holder("Request", gl
->gl_req_gh
);
2261 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2262 error
= dump_holder("Holder", gh
);
2266 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2267 error
= dump_holder("Waiter1", gh
);
2271 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2272 error
= dump_holder("Waiter2", gh
);
2276 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2277 error
= dump_holder("Waiter3", gh
);
2281 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2282 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2283 list_empty(&gl
->gl_holders
)) {
2284 error
= dump_inode(gl
->gl_object
);
2289 printk(KERN_INFO
" Inode: busy\n");
2296 spin_unlock(&gl
->gl_spin
);
2302 * gfs2_dump_lockstate - print out the current lockstate
2303 * @sdp: the filesystem
2304 * @ub: the buffer to copy the information into
2306 * If @ub is NULL, dump the lockstate to the console.
2310 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2312 struct gfs2_gl_hash_bucket
*bucket
;
2313 struct gfs2_glock
*gl
;
2317 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2318 bucket
= &sdp
->sd_gl_hash
[x
];
2320 read_lock(&bucket
->hb_lock
);
2322 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2323 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2326 error
= dump_glock(gl
);
2331 read_unlock(&bucket
->hb_lock
);