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(const 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_gl_hash_bucket
*bucket
= gl
->gl_bucket
;
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
);
160 BUG_ON(spin_is_locked(&gl
->gl_spin
));
165 write_unlock(&bucket
->hb_lock
);
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 const 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 static struct gfs2_glock
*gfs2_glock_find(struct gfs2_sbd
*sdp
,
230 const 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 const 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
);
283 kref_init(&gl
->gl_ref
);
284 gl
->gl_state
= LM_ST_UNLOCKED
;
288 gl
->gl_req_gh
= NULL
;
289 gl
->gl_req_bh
= NULL
;
291 gl
->gl_stamp
= jiffies
;
292 gl
->gl_object
= NULL
;
293 gl
->gl_bucket
= bucket
;
295 gl
->gl_aspace
= NULL
;
296 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
298 /* If this glock protects actual on-disk data or metadata blocks,
299 create a VFS inode to manage the pages/buffers holding them. */
300 if (glops
== &gfs2_inode_glops
||
301 glops
== &gfs2_rgrp_glops
) {
302 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
303 if (!gl
->gl_aspace
) {
309 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
313 write_lock(&bucket
->hb_lock
);
314 tmp
= search_bucket(bucket
, &name
);
316 write_unlock(&bucket
->hb_lock
);
320 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
321 write_unlock(&bucket
->hb_lock
);
330 gfs2_aspace_put(gl
->gl_aspace
);
332 kmem_cache_free(gfs2_glock_cachep
, gl
);
337 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
339 * @state: the state we're requesting
340 * @flags: the modifier flags
341 * @gh: the holder structure
345 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
346 struct gfs2_holder
*gh
)
348 INIT_LIST_HEAD(&gh
->gh_list
);
350 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
351 gh
->gh_owner
= current
;
352 gh
->gh_state
= state
;
353 gh
->gh_flags
= flags
;
356 init_completion(&gh
->gh_wait
);
358 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
359 gh
->gh_flags
|= GL_LOCAL_EXCL
;
365 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
366 * @state: the state we're requesting
367 * @flags: the modifier flags
368 * @gh: the holder structure
370 * Don't mess with the glock.
374 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
376 gh
->gh_state
= state
;
377 gh
->gh_flags
= flags
;
378 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
379 gh
->gh_flags
|= GL_LOCAL_EXCL
;
381 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
382 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
386 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
387 * @gh: the holder structure
391 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
393 gfs2_glock_put(gh
->gh_gl
);
399 * gfs2_holder_get - get a struct gfs2_holder structure
401 * @state: the state we're requesting
402 * @flags: the modifier flags
405 * Figure out how big an impact this function has. Either:
406 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
407 * 2) Leave it like it is
409 * Returns: the holder structure, NULL on ENOMEM
412 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
414 int flags
, gfp_t gfp_flags
)
416 struct gfs2_holder
*gh
;
418 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
422 gfs2_holder_init(gl
, state
, flags
, gh
);
423 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
424 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
429 * gfs2_holder_put - get rid of a struct gfs2_holder structure
430 * @gh: the holder structure
434 static void gfs2_holder_put(struct gfs2_holder
*gh
)
436 gfs2_holder_uninit(gh
);
441 * rq_mutex - process a mutex request in the queue
442 * @gh: the glock holder
444 * Returns: 1 if the queue is blocked
447 static int rq_mutex(struct gfs2_holder
*gh
)
449 struct gfs2_glock
*gl
= gh
->gh_gl
;
451 list_del_init(&gh
->gh_list
);
452 /* gh->gh_error never examined. */
453 set_bit(GLF_LOCK
, &gl
->gl_flags
);
454 complete(&gh
->gh_wait
);
460 * rq_promote - process a promote request in the queue
461 * @gh: the glock holder
463 * Acquire a new inter-node lock, or change a lock state to more restrictive.
465 * Returns: 1 if the queue is blocked
468 static int rq_promote(struct gfs2_holder
*gh
)
470 struct gfs2_glock
*gl
= gh
->gh_gl
;
471 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
472 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
474 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
475 if (list_empty(&gl
->gl_holders
)) {
477 set_bit(GLF_LOCK
, &gl
->gl_flags
);
478 spin_unlock(&gl
->gl_spin
);
480 if (atomic_read(&sdp
->sd_reclaim_count
) >
481 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
482 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
483 gfs2_reclaim_glock(sdp
);
484 gfs2_reclaim_glock(sdp
);
487 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
488 spin_lock(&gl
->gl_spin
);
493 if (list_empty(&gl
->gl_holders
)) {
494 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
495 set_bit(GLF_LOCK
, &gl
->gl_flags
);
497 struct gfs2_holder
*next_gh
;
498 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
500 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
502 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
506 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
508 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
510 complete(&gh
->gh_wait
);
516 * rq_demote - process a demote request in the queue
517 * @gh: the glock holder
519 * Returns: 1 if the queue is blocked
522 static int rq_demote(struct gfs2_holder
*gh
)
524 struct gfs2_glock
*gl
= gh
->gh_gl
;
525 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
527 if (!list_empty(&gl
->gl_holders
))
530 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
531 list_del_init(&gh
->gh_list
);
533 spin_unlock(&gl
->gl_spin
);
534 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
537 complete(&gh
->gh_wait
);
538 spin_lock(&gl
->gl_spin
);
541 set_bit(GLF_LOCK
, &gl
->gl_flags
);
542 spin_unlock(&gl
->gl_spin
);
544 if (gh
->gh_state
== LM_ST_UNLOCKED
||
545 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
546 glops
->go_drop_th(gl
);
548 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
550 spin_lock(&gl
->gl_spin
);
557 * rq_greedy - process a queued request to drop greedy status
558 * @gh: the glock holder
560 * Returns: 1 if the queue is blocked
563 static int rq_greedy(struct gfs2_holder
*gh
)
565 struct gfs2_glock
*gl
= gh
->gh_gl
;
567 list_del_init(&gh
->gh_list
);
568 /* gh->gh_error never examined. */
569 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
570 spin_unlock(&gl
->gl_spin
);
572 gfs2_holder_uninit(gh
);
573 kfree(container_of(gh
, struct greedy
, gr_gh
));
575 spin_lock(&gl
->gl_spin
);
581 * run_queue - process holder structures on a glock
585 static void run_queue(struct gfs2_glock
*gl
)
587 struct gfs2_holder
*gh
;
591 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
594 if (!list_empty(&gl
->gl_waiters1
)) {
595 gh
= list_entry(gl
->gl_waiters1
.next
,
596 struct gfs2_holder
, gh_list
);
598 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
599 blocked
= rq_mutex(gh
);
601 gfs2_assert_warn(gl
->gl_sbd
, 0);
603 } else if (!list_empty(&gl
->gl_waiters2
) &&
604 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
605 gh
= list_entry(gl
->gl_waiters2
.next
,
606 struct gfs2_holder
, gh_list
);
608 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
609 blocked
= rq_demote(gh
);
610 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
611 blocked
= rq_greedy(gh
);
613 gfs2_assert_warn(gl
->gl_sbd
, 0);
615 } else if (!list_empty(&gl
->gl_waiters3
)) {
616 gh
= list_entry(gl
->gl_waiters3
.next
,
617 struct gfs2_holder
, gh_list
);
619 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
620 blocked
= rq_promote(gh
);
622 gfs2_assert_warn(gl
->gl_sbd
, 0);
633 * gfs2_glmutex_lock - acquire a local lock on a glock
636 * Gives caller exclusive access to manipulate a glock structure.
639 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
641 struct gfs2_holder gh
;
643 gfs2_holder_init(gl
, 0, 0, &gh
);
644 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
646 spin_lock(&gl
->gl_spin
);
647 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
648 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
650 gl
->gl_owner
= current
;
651 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
652 complete(&gh
.gh_wait
);
654 spin_unlock(&gl
->gl_spin
);
656 wait_for_completion(&gh
.gh_wait
);
657 gfs2_holder_uninit(&gh
);
661 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
664 * Returns: 1 if the glock is acquired
667 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
671 spin_lock(&gl
->gl_spin
);
672 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
675 gl
->gl_owner
= current
;
676 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
678 spin_unlock(&gl
->gl_spin
);
684 * gfs2_glmutex_unlock - release a local lock on a glock
689 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
691 spin_lock(&gl
->gl_spin
);
692 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
696 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
697 spin_unlock(&gl
->gl_spin
);
701 * handle_callback - add a demote request to a lock's queue
703 * @state: the state the caller wants us to change to
705 * Note: This may fail sliently if we are out of memory.
708 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
710 struct gfs2_holder
*gh
, *new_gh
= NULL
;
713 spin_lock(&gl
->gl_spin
);
715 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
716 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
717 gl
->gl_req_gh
!= gh
) {
718 if (gh
->gh_state
!= state
)
719 gh
->gh_state
= LM_ST_UNLOCKED
;
725 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
728 spin_unlock(&gl
->gl_spin
);
730 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_KERNEL
);
733 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
734 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
740 spin_unlock(&gl
->gl_spin
);
743 gfs2_holder_put(new_gh
);
746 void gfs2_glock_inode_squish(struct inode
*inode
)
748 struct gfs2_holder gh
;
749 struct gfs2_glock
*gl
= GFS2_I(inode
)->i_gl
;
750 gfs2_holder_init(gl
, LM_ST_UNLOCKED
, 0, &gh
);
751 set_bit(HIF_DEMOTE
, &gh
.gh_iflags
);
752 spin_lock(&gl
->gl_spin
);
753 gfs2_assert(inode
->i_sb
->s_fs_info
, list_empty(&gl
->gl_holders
));
754 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters2
);
756 spin_unlock(&gl
->gl_spin
);
757 wait_for_completion(&gh
.gh_wait
);
758 gfs2_holder_uninit(&gh
);
762 * state_change - record that the glock is now in a different state
764 * @new_state the new state
768 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
772 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
773 held2
= (new_state
!= LM_ST_UNLOCKED
);
775 if (held1
!= held2
) {
782 gl
->gl_state
= new_state
;
786 * xmote_bh - Called after the lock module is done acquiring a lock
787 * @gl: The glock in question
788 * @ret: the int returned from the lock module
792 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
794 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
795 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
796 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
797 int prev_state
= gl
->gl_state
;
800 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
801 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
802 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
804 state_change(gl
, ret
& LM_OUT_ST_MASK
);
806 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
808 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
809 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
810 /* We might not want to do this here.
811 Look at moving to the inode glops. */
813 glops
->go_inval(gl
, DIO_DATA
);
816 /* Deal with each possible exit condition */
819 gl
->gl_stamp
= jiffies
;
821 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
822 spin_lock(&gl
->gl_spin
);
823 list_del_init(&gh
->gh_list
);
825 spin_unlock(&gl
->gl_spin
);
827 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
828 spin_lock(&gl
->gl_spin
);
829 list_del_init(&gh
->gh_list
);
830 if (gl
->gl_state
== gh
->gh_state
||
831 gl
->gl_state
== LM_ST_UNLOCKED
)
834 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
835 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
836 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
837 gh
->gh_error
= GLR_TRYFAILED
;
839 spin_unlock(&gl
->gl_spin
);
841 if (ret
& LM_OUT_CANCELED
)
842 handle_callback(gl
, LM_ST_UNLOCKED
); /* Lame */
844 } else if (ret
& LM_OUT_CANCELED
) {
845 spin_lock(&gl
->gl_spin
);
846 list_del_init(&gh
->gh_list
);
847 gh
->gh_error
= GLR_CANCELED
;
848 spin_unlock(&gl
->gl_spin
);
850 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
851 spin_lock(&gl
->gl_spin
);
852 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
854 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
855 spin_unlock(&gl
->gl_spin
);
857 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
861 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
862 spin_lock(&gl
->gl_spin
);
863 list_del_init(&gh
->gh_list
);
864 gh
->gh_error
= GLR_TRYFAILED
;
865 spin_unlock(&gl
->gl_spin
);
868 if (gfs2_assert_withdraw(sdp
, 0) == -1)
869 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
872 if (glops
->go_xmote_bh
)
873 glops
->go_xmote_bh(gl
);
876 spin_lock(&gl
->gl_spin
);
877 gl
->gl_req_gh
= NULL
;
878 gl
->gl_req_bh
= NULL
;
879 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
881 spin_unlock(&gl
->gl_spin
);
887 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
890 complete(&gh
->gh_wait
);
895 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
896 * @gl: The glock in question
897 * @state: the requested state
898 * @flags: modifier flags to the lock call
902 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
904 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
905 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
906 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
907 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
909 unsigned int lck_ret
;
911 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
912 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
913 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
914 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
916 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
919 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
923 gl
->gl_req_bh
= xmote_bh
;
925 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
, lck_flags
);
927 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
930 if (lck_ret
& LM_OUT_ASYNC
)
931 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
933 xmote_bh(gl
, lck_ret
);
937 * drop_bh - Called after a lock module unlock completes
939 * @ret: the return status
941 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
942 * Doesn't drop the reference on the glock the top half took out
946 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
948 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
949 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
950 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
952 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
954 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
955 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
956 gfs2_assert_warn(sdp
, !ret
);
958 state_change(gl
, LM_ST_UNLOCKED
);
961 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
964 spin_lock(&gl
->gl_spin
);
965 list_del_init(&gh
->gh_list
);
967 spin_unlock(&gl
->gl_spin
);
970 if (glops
->go_drop_bh
)
971 glops
->go_drop_bh(gl
);
973 spin_lock(&gl
->gl_spin
);
974 gl
->gl_req_gh
= NULL
;
975 gl
->gl_req_bh
= NULL
;
976 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
978 spin_unlock(&gl
->gl_spin
);
983 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
986 complete(&gh
->gh_wait
);
991 * gfs2_glock_drop_th - call into the lock module to unlock a lock
996 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
998 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
999 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1002 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1003 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1004 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1006 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1008 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1011 gfs2_glock_hold(gl
);
1012 gl
->gl_req_bh
= drop_bh
;
1014 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1016 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1022 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1026 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1027 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1029 * Don't cancel GL_NOCANCEL requests.
1032 static void do_cancels(struct gfs2_holder
*gh
)
1034 struct gfs2_glock
*gl
= gh
->gh_gl
;
1036 spin_lock(&gl
->gl_spin
);
1038 while (gl
->gl_req_gh
!= gh
&&
1039 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1040 !list_empty(&gh
->gh_list
)) {
1041 if (gl
->gl_req_bh
&&
1043 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1044 spin_unlock(&gl
->gl_spin
);
1045 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1047 spin_lock(&gl
->gl_spin
);
1049 spin_unlock(&gl
->gl_spin
);
1051 spin_lock(&gl
->gl_spin
);
1055 spin_unlock(&gl
->gl_spin
);
1059 * glock_wait_internal - wait on a glock acquisition
1060 * @gh: the glock holder
1062 * Returns: 0 on success
1065 static int glock_wait_internal(struct gfs2_holder
*gh
)
1067 struct gfs2_glock
*gl
= gh
->gh_gl
;
1068 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1069 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1071 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1074 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1075 spin_lock(&gl
->gl_spin
);
1076 if (gl
->gl_req_gh
!= gh
&&
1077 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1078 !list_empty(&gh
->gh_list
)) {
1079 list_del_init(&gh
->gh_list
);
1080 gh
->gh_error
= GLR_TRYFAILED
;
1082 spin_unlock(&gl
->gl_spin
);
1083 return gh
->gh_error
;
1085 spin_unlock(&gl
->gl_spin
);
1088 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1091 wait_for_completion(&gh
->gh_wait
);
1094 return gh
->gh_error
;
1096 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1097 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1101 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1102 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1104 if (glops
->go_lock
) {
1105 gh
->gh_error
= glops
->go_lock(gh
);
1107 spin_lock(&gl
->gl_spin
);
1108 list_del_init(&gh
->gh_list
);
1109 spin_unlock(&gl
->gl_spin
);
1113 spin_lock(&gl
->gl_spin
);
1114 gl
->gl_req_gh
= NULL
;
1115 gl
->gl_req_bh
= NULL
;
1116 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1118 spin_unlock(&gl
->gl_spin
);
1121 return gh
->gh_error
;
1124 static inline struct gfs2_holder
*
1125 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1127 struct gfs2_holder
*gh
;
1129 list_for_each_entry(gh
, head
, gh_list
) {
1130 if (gh
->gh_owner
== owner
)
1138 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1139 * @gh: the holder structure to add
1143 static void add_to_queue(struct gfs2_holder
*gh
)
1145 struct gfs2_glock
*gl
= gh
->gh_gl
;
1146 struct gfs2_holder
*existing
;
1148 BUG_ON(!gh
->gh_owner
);
1150 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1152 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1153 printk(KERN_INFO
"pid : %d\n", existing
->gh_owner
->pid
);
1154 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1155 existing
->gh_gl
->gl_name
.ln_type
, existing
->gh_gl
->gl_state
);
1156 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1157 printk(KERN_INFO
"pid : %d\n", gh
->gh_owner
->pid
);
1158 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1159 gl
->gl_name
.ln_type
, gl
->gl_state
);
1163 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1165 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1166 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1170 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1171 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1173 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1177 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1178 * @gh: the holder structure
1180 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1182 * Returns: 0, GLR_TRYFAILED, or errno on failure
1185 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1187 struct gfs2_glock
*gl
= gh
->gh_gl
;
1188 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1192 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1193 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1197 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1199 spin_lock(&gl
->gl_spin
);
1202 spin_unlock(&gl
->gl_spin
);
1204 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1205 error
= glock_wait_internal(gh
);
1206 if (error
== GLR_CANCELED
) {
1212 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1214 if (error
== GLR_TRYFAILED
&& (gh
->gh_flags
& GL_DUMP
))
1221 * gfs2_glock_poll - poll to see if an async request has been completed
1224 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1227 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1229 struct gfs2_glock
*gl
= gh
->gh_gl
;
1232 spin_lock(&gl
->gl_spin
);
1234 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1236 else if (list_empty(&gh
->gh_list
)) {
1237 if (gh
->gh_error
== GLR_CANCELED
) {
1238 spin_unlock(&gl
->gl_spin
);
1240 if (gfs2_glock_nq(gh
))
1247 spin_unlock(&gl
->gl_spin
);
1253 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1254 * @gh: the holder structure
1256 * Returns: 0, GLR_TRYFAILED, or errno on failure
1259 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1263 error
= glock_wait_internal(gh
);
1264 if (error
== GLR_CANCELED
) {
1266 gh
->gh_flags
&= ~GL_ASYNC
;
1267 error
= gfs2_glock_nq(gh
);
1274 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1275 * @gh: the glock holder
1279 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1281 struct gfs2_glock
*gl
= gh
->gh_gl
;
1282 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
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 gl
->gl_stamp
= jiffies
;
1300 spin_lock(&gl
->gl_spin
);
1303 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1305 spin_unlock(&gl
->gl_spin
);
1309 * gfs2_glock_prefetch - Try to prefetch a glock
1311 * @state: the state to prefetch in
1312 * @flags: flags passed to go_xmote_th()
1316 static void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
,
1319 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1321 spin_lock(&gl
->gl_spin
);
1323 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1324 !list_empty(&gl
->gl_holders
) ||
1325 !list_empty(&gl
->gl_waiters1
) ||
1326 !list_empty(&gl
->gl_waiters2
) ||
1327 !list_empty(&gl
->gl_waiters3
) ||
1328 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1329 spin_unlock(&gl
->gl_spin
);
1333 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1334 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1335 spin_unlock(&gl
->gl_spin
);
1337 glops
->go_xmote_th(gl
, state
, flags
);
1340 static void greedy_work(void *data
)
1342 struct greedy
*gr
= data
;
1343 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1344 struct gfs2_glock
*gl
= gh
->gh_gl
;
1345 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1347 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1349 if (glops
->go_greedy
)
1350 glops
->go_greedy(gl
);
1352 spin_lock(&gl
->gl_spin
);
1354 if (list_empty(&gl
->gl_waiters2
)) {
1355 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1356 spin_unlock(&gl
->gl_spin
);
1357 gfs2_holder_uninit(gh
);
1360 gfs2_glock_hold(gl
);
1361 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1363 spin_unlock(&gl
->gl_spin
);
1369 * gfs2_glock_be_greedy -
1373 * Returns: 0 if go_greedy will be called, 1 otherwise
1376 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1379 struct gfs2_holder
*gh
;
1381 if (!time
|| gl
->gl_sbd
->sd_args
.ar_localcaching
||
1382 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1385 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1387 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1392 gfs2_holder_init(gl
, 0, 0, gh
);
1393 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1394 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1396 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1397 schedule_delayed_work(&gr
->gr_work
, time
);
1403 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1404 * @gh: the holder structure
1408 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1411 gfs2_holder_uninit(gh
);
1415 * gfs2_glock_nq_num - acquire a glock based on lock number
1416 * @sdp: the filesystem
1417 * @number: the lock number
1418 * @glops: the glock operations for the type of glock
1419 * @state: the state to acquire the glock in
1420 * @flags: modifier flags for the aquisition
1421 * @gh: the struct gfs2_holder
1426 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1427 const struct gfs2_glock_operations
*glops
,
1428 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1430 struct gfs2_glock
*gl
;
1433 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1435 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1443 * glock_compare - Compare two struct gfs2_glock structures for sorting
1444 * @arg_a: the first structure
1445 * @arg_b: the second structure
1449 static int glock_compare(const void *arg_a
, const void *arg_b
)
1451 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1452 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1453 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1454 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1457 if (a
->ln_number
> b
->ln_number
)
1459 else if (a
->ln_number
< b
->ln_number
)
1462 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1463 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1465 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1466 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1474 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1475 * @num_gh: the number of structures
1476 * @ghs: an array of struct gfs2_holder structures
1478 * Returns: 0 on success (all glocks acquired),
1479 * errno on failure (no glocks acquired)
1482 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1483 struct gfs2_holder
**p
)
1488 for (x
= 0; x
< num_gh
; x
++)
1491 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1493 for (x
= 0; x
< num_gh
; x
++) {
1494 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1496 error
= gfs2_glock_nq(p
[x
]);
1499 gfs2_glock_dq(p
[x
]);
1508 * gfs2_glock_nq_m - acquire multiple glocks
1509 * @num_gh: the number of structures
1510 * @ghs: an array of struct gfs2_holder structures
1512 * Figure out how big an impact this function has. Either:
1513 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1514 * 2) Forget async stuff and just call nq_m_sync()
1515 * 3) Leave it like it is
1517 * Returns: 0 on success (all glocks acquired),
1518 * errno on failure (no glocks acquired)
1521 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1525 int borked
= 0, serious
= 0;
1532 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1533 return gfs2_glock_nq(ghs
);
1536 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1540 for (x
= 0; x
< num_gh
; x
++) {
1541 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1542 error
= gfs2_glock_nq(&ghs
[x
]);
1551 for (x
= 0; x
< num_gh
; x
++) {
1552 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1555 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1565 for (x
= 0; x
< num_gh
; x
++)
1567 gfs2_glock_dq(&ghs
[x
]);
1572 for (x
= 0; x
< num_gh
; x
++)
1573 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1575 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1584 * gfs2_glock_dq_m - release multiple glocks
1585 * @num_gh: the number of structures
1586 * @ghs: an array of struct gfs2_holder structures
1590 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1594 for (x
= 0; x
< num_gh
; x
++)
1595 gfs2_glock_dq(&ghs
[x
]);
1599 * gfs2_glock_dq_uninit_m - release multiple glocks
1600 * @num_gh: the number of structures
1601 * @ghs: an array of struct gfs2_holder structures
1605 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1609 for (x
= 0; x
< num_gh
; x
++)
1610 gfs2_glock_dq_uninit(&ghs
[x
]);
1614 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1615 * @sdp: the filesystem
1616 * @number: the lock number
1617 * @glops: the glock operations for the type of glock
1618 * @state: the state to acquire the glock in
1619 * @flags: modifier flags for the aquisition
1624 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1625 const struct gfs2_glock_operations
*glops
,
1626 unsigned int state
, int flags
)
1628 struct gfs2_glock
*gl
;
1631 if (atomic_read(&sdp
->sd_reclaim_count
) <
1632 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1633 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1635 gfs2_glock_prefetch(gl
, state
, flags
);
1642 * gfs2_lvb_hold - attach a LVB from a glock
1643 * @gl: The glock in question
1647 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1651 gfs2_glmutex_lock(gl
);
1653 if (!atomic_read(&gl
->gl_lvb_count
)) {
1654 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1656 gfs2_glmutex_unlock(gl
);
1659 gfs2_glock_hold(gl
);
1661 atomic_inc(&gl
->gl_lvb_count
);
1663 gfs2_glmutex_unlock(gl
);
1669 * gfs2_lvb_unhold - detach a LVB from a glock
1670 * @gl: The glock in question
1674 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1676 gfs2_glock_hold(gl
);
1677 gfs2_glmutex_lock(gl
);
1679 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1680 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1681 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1686 gfs2_glmutex_unlock(gl
);
1691 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1693 gfs2_glmutex_lock(gl
);
1695 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1696 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1697 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1699 gfs2_glmutex_unlock(gl
);
1703 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1706 struct gfs2_glock
*gl
;
1708 gl
= gfs2_glock_find(sdp
, name
);
1712 if (gl
->gl_ops
->go_callback
)
1713 gl
->gl_ops
->go_callback(gl
, state
);
1714 handle_callback(gl
, state
);
1716 spin_lock(&gl
->gl_spin
);
1718 spin_unlock(&gl
->gl_spin
);
1724 * gfs2_glock_cb - Callback used by locking module
1725 * @fsdata: Pointer to the superblock
1726 * @type: Type of callback
1727 * @data: Type dependent data pointer
1729 * Called by the locking module when it wants to tell us something.
1730 * Either we need to drop a lock, one of our ASYNC requests completed, or
1731 * a journal from another client needs to be recovered.
1734 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1736 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1740 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1744 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1748 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1752 struct lm_async_cb
*async
= data
;
1753 struct gfs2_glock
*gl
;
1755 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1756 if (gfs2_assert_warn(sdp
, gl
))
1758 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1759 gl
->gl_req_bh(gl
, async
->lc_ret
);
1764 case LM_CB_NEED_RECOVERY
:
1765 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1766 if (sdp
->sd_recoverd_process
)
1767 wake_up_process(sdp
->sd_recoverd_process
);
1770 case LM_CB_DROPLOCKS
:
1771 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1772 gfs2_quota_scan(sdp
);
1776 gfs2_assert_warn(sdp
, 0);
1782 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1783 * iopen glock from memory
1784 * @io_gl: the iopen glock
1785 * @state: the state into which the glock should be put
1789 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1792 if (state
!= LM_ST_UNLOCKED
)
1794 /* FIXME: remove this? */
1798 * demote_ok - Check to see if it's ok to unlock a glock
1801 * Returns: 1 if it's ok
1804 static int demote_ok(struct gfs2_glock
*gl
)
1806 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1807 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1810 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1812 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
1813 demote
= time_after_eq(jiffies
,
1815 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
1816 else if (glops
->go_demote_ok
)
1817 demote
= glops
->go_demote_ok(gl
);
1823 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1828 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1830 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1832 spin_lock(&sdp
->sd_reclaim_lock
);
1833 if (list_empty(&gl
->gl_reclaim
)) {
1834 gfs2_glock_hold(gl
);
1835 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1836 atomic_inc(&sdp
->sd_reclaim_count
);
1838 spin_unlock(&sdp
->sd_reclaim_lock
);
1840 wake_up(&sdp
->sd_reclaim_wq
);
1844 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1845 * @sdp: the filesystem
1847 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1848 * different glock and we notice that there are a lot of glocks in the
1853 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1855 struct gfs2_glock
*gl
;
1857 spin_lock(&sdp
->sd_reclaim_lock
);
1858 if (list_empty(&sdp
->sd_reclaim_list
)) {
1859 spin_unlock(&sdp
->sd_reclaim_lock
);
1862 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1863 struct gfs2_glock
, gl_reclaim
);
1864 list_del_init(&gl
->gl_reclaim
);
1865 spin_unlock(&sdp
->sd_reclaim_lock
);
1867 atomic_dec(&sdp
->sd_reclaim_count
);
1868 atomic_inc(&sdp
->sd_reclaimed
);
1870 if (gfs2_glmutex_trylock(gl
)) {
1871 if (queue_empty(gl
, &gl
->gl_holders
) &&
1872 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1874 handle_callback(gl
, LM_ST_UNLOCKED
);
1875 gfs2_glmutex_unlock(gl
);
1882 * examine_bucket - Call a function for glock in a hash bucket
1883 * @examiner: the function
1884 * @sdp: the filesystem
1885 * @bucket: the bucket
1887 * Returns: 1 if the bucket has entries
1890 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1891 struct gfs2_gl_hash_bucket
*bucket
)
1893 struct glock_plug plug
;
1894 struct list_head
*tmp
;
1895 struct gfs2_glock
*gl
;
1898 /* Add "plug" to end of bucket list, work back up list from there */
1899 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
1900 set_bit(GLF_PLUG
, &plug
.gl_flags
);
1902 write_lock(&bucket
->hb_lock
);
1903 list_add(&plug
.gl_list
, &bucket
->hb_list
);
1904 write_unlock(&bucket
->hb_lock
);
1907 write_lock(&bucket
->hb_lock
);
1910 tmp
= plug
.gl_list
.next
;
1912 if (tmp
== &bucket
->hb_list
) {
1913 list_del(&plug
.gl_list
);
1914 entries
= !list_empty(&bucket
->hb_list
);
1915 write_unlock(&bucket
->hb_lock
);
1918 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
1920 /* Move plug up list */
1921 list_move(&plug
.gl_list
, &gl
->gl_list
);
1923 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
1926 /* examiner() must glock_put() */
1927 gfs2_glock_hold(gl
);
1932 write_unlock(&bucket
->hb_lock
);
1939 * scan_glock - look at a glock and see if we can reclaim it
1940 * @gl: the glock to look at
1944 static void scan_glock(struct gfs2_glock
*gl
)
1946 if (gl
->gl_ops
== &gfs2_inode_glops
)
1949 if (gfs2_glmutex_trylock(gl
)) {
1950 if (queue_empty(gl
, &gl
->gl_holders
) &&
1951 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1954 gfs2_glmutex_unlock(gl
);
1961 gfs2_glmutex_unlock(gl
);
1962 gfs2_glock_schedule_for_reclaim(gl
);
1967 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1968 * @sdp: the filesystem
1972 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1976 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1977 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
1983 * clear_glock - look at a glock and see if we can free it from glock cache
1984 * @gl: the glock to look at
1988 static void clear_glock(struct gfs2_glock
*gl
)
1990 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1993 spin_lock(&sdp
->sd_reclaim_lock
);
1994 if (!list_empty(&gl
->gl_reclaim
)) {
1995 list_del_init(&gl
->gl_reclaim
);
1996 atomic_dec(&sdp
->sd_reclaim_count
);
1997 spin_unlock(&sdp
->sd_reclaim_lock
);
1998 released
= gfs2_glock_put(gl
);
1999 gfs2_assert(sdp
, !released
);
2001 spin_unlock(&sdp
->sd_reclaim_lock
);
2004 if (gfs2_glmutex_trylock(gl
)) {
2005 if (queue_empty(gl
, &gl
->gl_holders
) &&
2006 gl
->gl_state
!= LM_ST_UNLOCKED
)
2007 handle_callback(gl
, LM_ST_UNLOCKED
);
2009 gfs2_glmutex_unlock(gl
);
2016 * gfs2_gl_hash_clear - Empty out the glock hash table
2017 * @sdp: the filesystem
2018 * @wait: wait until it's all gone
2020 * Called when unmounting the filesystem, or when inter-node lock manager
2021 * requests DROPLOCKS because it is running out of capacity.
2024 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2035 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2036 if (examine_bucket(clear_glock
, sdp
,
2037 &sdp
->sd_gl_hash
[x
]))
2043 if (time_after_eq(jiffies
,
2044 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2045 fs_warn(sdp
, "Unmount seems to be stalled. "
2046 "Dumping lock state...\n");
2047 gfs2_dump_lockstate(sdp
);
2051 invalidate_inodes(sdp
->sd_vfs
);
2057 * Diagnostic routines to help debug distributed deadlock
2061 * dump_holder - print information about a glock holder
2062 * @str: a string naming the type of holder
2063 * @gh: the glock holder
2065 * Returns: 0 on success, -ENOBUFS when we run out of space
2068 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2071 int error
= -ENOBUFS
;
2073 printk(KERN_INFO
" %s\n", str
);
2074 printk(KERN_INFO
" owner = %ld\n",
2075 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2076 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2077 printk(KERN_INFO
" gh_flags =");
2078 for (x
= 0; x
< 32; x
++)
2079 if (gh
->gh_flags
& (1 << x
))
2082 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2083 printk(KERN_INFO
" gh_iflags =");
2084 for (x
= 0; x
< 32; x
++)
2085 if (test_bit(x
, &gh
->gh_iflags
))
2088 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2096 * dump_inode - print information about an inode
2099 * Returns: 0 on success, -ENOBUFS when we run out of space
2102 static int dump_inode(struct gfs2_inode
*ip
)
2105 int error
= -ENOBUFS
;
2107 printk(KERN_INFO
" Inode:\n");
2108 printk(KERN_INFO
" num = %llu %llu\n",
2109 (unsigned long long)ip
->i_num
.no_formal_ino
,
2110 (unsigned long long)ip
->i_num
.no_addr
);
2111 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2112 printk(KERN_INFO
" i_flags =");
2113 for (x
= 0; x
< 32; x
++)
2114 if (test_bit(x
, &ip
->i_flags
))
2124 * dump_glock - print information about a glock
2126 * @count: where we are in the buffer
2128 * Returns: 0 on success, -ENOBUFS when we run out of space
2131 static int dump_glock(struct gfs2_glock
*gl
)
2133 struct gfs2_holder
*gh
;
2135 int error
= -ENOBUFS
;
2137 spin_lock(&gl
->gl_spin
);
2139 printk(KERN_INFO
"Glock 0x%p (%u, %llu)\n",
2141 gl
->gl_name
.ln_type
,
2142 (unsigned long long)gl
->gl_name
.ln_number
);
2143 printk(KERN_INFO
" gl_flags =");
2144 for (x
= 0; x
< 32; x
++)
2145 if (test_bit(x
, &gl
->gl_flags
))
2148 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2149 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2150 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
2151 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
2152 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2153 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2154 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2155 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2156 printk(KERN_INFO
" le = %s\n",
2157 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2158 printk(KERN_INFO
" reclaim = %s\n",
2159 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2161 printk(KERN_INFO
" aspace = 0x%p nrpages = %lu\n",
2163 gl
->gl_aspace
->i_mapping
->nrpages
);
2165 printk(KERN_INFO
" aspace = no\n");
2166 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2167 if (gl
->gl_req_gh
) {
2168 error
= dump_holder("Request", gl
->gl_req_gh
);
2172 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2173 error
= dump_holder("Holder", gh
);
2177 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2178 error
= dump_holder("Waiter1", gh
);
2182 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2183 error
= dump_holder("Waiter2", gh
);
2187 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2188 error
= dump_holder("Waiter3", gh
);
2192 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2193 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2194 list_empty(&gl
->gl_holders
)) {
2195 error
= dump_inode(gl
->gl_object
);
2200 printk(KERN_INFO
" Inode: busy\n");
2207 spin_unlock(&gl
->gl_spin
);
2213 * gfs2_dump_lockstate - print out the current lockstate
2214 * @sdp: the filesystem
2215 * @ub: the buffer to copy the information into
2217 * If @ub is NULL, dump the lockstate to the console.
2221 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2223 struct gfs2_gl_hash_bucket
*bucket
;
2224 struct gfs2_glock
*gl
;
2228 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2229 bucket
= &sdp
->sd_gl_hash
[x
];
2231 read_lock(&bucket
->hb_lock
);
2233 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2234 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2237 error
= dump_glock(gl
);
2242 read_unlock(&bucket
->hb_lock
);
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