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 version 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 gfs2_sbd
*sdp
,
204 const struct lm_lockname
*name
)
206 struct gfs2_glock
*gl
;
208 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
209 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
211 if (!lm_name_equal(&gl
->gl_name
, name
))
213 if (gl
->gl_sbd
!= sdp
)
216 kref_get(&gl
->gl_ref
);
225 * gfs2_glock_find() - Find glock by lock number
226 * @sdp: The GFS2 superblock
227 * @name: The lock name
229 * Returns: NULL, or the struct gfs2_glock with the requested number
232 static struct gfs2_glock
*gfs2_glock_find(struct gfs2_sbd
*sdp
,
233 const struct lm_lockname
*name
)
235 struct gfs2_gl_hash_bucket
*bucket
= &sdp
->sd_gl_hash
[gl_hash(name
)];
236 struct gfs2_glock
*gl
;
238 read_lock(&bucket
->hb_lock
);
239 gl
= search_bucket(bucket
, sdp
, name
);
240 read_unlock(&bucket
->hb_lock
);
246 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
247 * @sdp: The GFS2 superblock
248 * @number: the lock number
249 * @glops: The glock_operations to use
250 * @create: If 0, don't create the glock if it doesn't exist
251 * @glp: the glock is returned here
253 * This does not lock a glock, just finds/creates structures for one.
258 int gfs2_glock_get(struct gfs2_sbd
*sdp
, uint64_t number
,
259 const struct gfs2_glock_operations
*glops
, int create
,
260 struct gfs2_glock
**glp
)
262 struct lm_lockname name
;
263 struct gfs2_glock
*gl
, *tmp
;
264 struct gfs2_gl_hash_bucket
*bucket
;
267 name
.ln_number
= number
;
268 name
.ln_type
= glops
->go_type
;
269 bucket
= &sdp
->sd_gl_hash
[gl_hash(&name
)];
271 read_lock(&bucket
->hb_lock
);
272 gl
= search_bucket(bucket
, sdp
, &name
);
273 read_unlock(&bucket
->hb_lock
);
280 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
286 kref_init(&gl
->gl_ref
);
287 gl
->gl_state
= LM_ST_UNLOCKED
;
291 gl
->gl_req_gh
= NULL
;
292 gl
->gl_req_bh
= NULL
;
294 gl
->gl_stamp
= jiffies
;
295 gl
->gl_object
= NULL
;
296 gl
->gl_bucket
= bucket
;
298 gl
->gl_aspace
= NULL
;
299 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
301 /* If this glock protects actual on-disk data or metadata blocks,
302 create a VFS inode to manage the pages/buffers holding them. */
303 if (glops
== &gfs2_inode_glops
|| glops
== &gfs2_rgrp_glops
) {
304 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
305 if (!gl
->gl_aspace
) {
311 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
315 write_lock(&bucket
->hb_lock
);
316 tmp
= search_bucket(bucket
, sdp
, &name
);
318 write_unlock(&bucket
->hb_lock
);
322 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
323 write_unlock(&bucket
->hb_lock
);
332 gfs2_aspace_put(gl
->gl_aspace
);
334 kmem_cache_free(gfs2_glock_cachep
, gl
);
339 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
341 * @state: the state we're requesting
342 * @flags: the modifier flags
343 * @gh: the holder structure
347 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
348 struct gfs2_holder
*gh
)
350 INIT_LIST_HEAD(&gh
->gh_list
);
352 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
353 gh
->gh_owner
= current
;
354 gh
->gh_state
= state
;
355 gh
->gh_flags
= flags
;
358 init_completion(&gh
->gh_wait
);
360 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
361 gh
->gh_flags
|= GL_LOCAL_EXCL
;
367 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
368 * @state: the state we're requesting
369 * @flags: the modifier flags
370 * @gh: the holder structure
372 * Don't mess with the glock.
376 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
378 gh
->gh_state
= state
;
379 gh
->gh_flags
= flags
;
380 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
381 gh
->gh_flags
|= GL_LOCAL_EXCL
;
383 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
384 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
388 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
389 * @gh: the holder structure
393 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
395 gfs2_glock_put(gh
->gh_gl
);
401 * gfs2_holder_get - get a struct gfs2_holder structure
403 * @state: the state we're requesting
404 * @flags: the modifier flags
407 * Figure out how big an impact this function has. Either:
408 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
409 * 2) Leave it like it is
411 * Returns: the holder structure, NULL on ENOMEM
414 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
416 int flags
, gfp_t gfp_flags
)
418 struct gfs2_holder
*gh
;
420 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
424 gfs2_holder_init(gl
, state
, flags
, gh
);
425 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
426 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
431 * gfs2_holder_put - get rid of a struct gfs2_holder structure
432 * @gh: the holder structure
436 static void gfs2_holder_put(struct gfs2_holder
*gh
)
438 gfs2_holder_uninit(gh
);
443 * rq_mutex - process a mutex request in the queue
444 * @gh: the glock holder
446 * Returns: 1 if the queue is blocked
449 static int rq_mutex(struct gfs2_holder
*gh
)
451 struct gfs2_glock
*gl
= gh
->gh_gl
;
453 list_del_init(&gh
->gh_list
);
454 /* gh->gh_error never examined. */
455 set_bit(GLF_LOCK
, &gl
->gl_flags
);
456 complete(&gh
->gh_wait
);
462 * rq_promote - process a promote request in the queue
463 * @gh: the glock holder
465 * Acquire a new inter-node lock, or change a lock state to more restrictive.
467 * Returns: 1 if the queue is blocked
470 static int rq_promote(struct gfs2_holder
*gh
)
472 struct gfs2_glock
*gl
= gh
->gh_gl
;
473 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
474 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
476 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
477 if (list_empty(&gl
->gl_holders
)) {
479 set_bit(GLF_LOCK
, &gl
->gl_flags
);
480 spin_unlock(&gl
->gl_spin
);
482 if (atomic_read(&sdp
->sd_reclaim_count
) >
483 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
484 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
485 gfs2_reclaim_glock(sdp
);
486 gfs2_reclaim_glock(sdp
);
489 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
490 spin_lock(&gl
->gl_spin
);
495 if (list_empty(&gl
->gl_holders
)) {
496 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
497 set_bit(GLF_LOCK
, &gl
->gl_flags
);
499 struct gfs2_holder
*next_gh
;
500 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
502 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
504 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
508 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
510 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
512 complete(&gh
->gh_wait
);
518 * rq_demote - process a demote request in the queue
519 * @gh: the glock holder
521 * Returns: 1 if the queue is blocked
524 static int rq_demote(struct gfs2_holder
*gh
)
526 struct gfs2_glock
*gl
= gh
->gh_gl
;
527 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
529 if (!list_empty(&gl
->gl_holders
))
532 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
533 list_del_init(&gh
->gh_list
);
535 spin_unlock(&gl
->gl_spin
);
536 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
539 complete(&gh
->gh_wait
);
540 spin_lock(&gl
->gl_spin
);
543 set_bit(GLF_LOCK
, &gl
->gl_flags
);
544 spin_unlock(&gl
->gl_spin
);
546 if (gh
->gh_state
== LM_ST_UNLOCKED
||
547 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
548 glops
->go_drop_th(gl
);
550 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
552 spin_lock(&gl
->gl_spin
);
559 * rq_greedy - process a queued request to drop greedy status
560 * @gh: the glock holder
562 * Returns: 1 if the queue is blocked
565 static int rq_greedy(struct gfs2_holder
*gh
)
567 struct gfs2_glock
*gl
= gh
->gh_gl
;
569 list_del_init(&gh
->gh_list
);
570 /* gh->gh_error never examined. */
571 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
572 spin_unlock(&gl
->gl_spin
);
574 gfs2_holder_uninit(gh
);
575 kfree(container_of(gh
, struct greedy
, gr_gh
));
577 spin_lock(&gl
->gl_spin
);
583 * run_queue - process holder structures on a glock
587 static void run_queue(struct gfs2_glock
*gl
)
589 struct gfs2_holder
*gh
;
593 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
596 if (!list_empty(&gl
->gl_waiters1
)) {
597 gh
= list_entry(gl
->gl_waiters1
.next
,
598 struct gfs2_holder
, gh_list
);
600 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
601 blocked
= rq_mutex(gh
);
603 gfs2_assert_warn(gl
->gl_sbd
, 0);
605 } else if (!list_empty(&gl
->gl_waiters2
) &&
606 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
607 gh
= list_entry(gl
->gl_waiters2
.next
,
608 struct gfs2_holder
, gh_list
);
610 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
611 blocked
= rq_demote(gh
);
612 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
613 blocked
= rq_greedy(gh
);
615 gfs2_assert_warn(gl
->gl_sbd
, 0);
617 } else if (!list_empty(&gl
->gl_waiters3
)) {
618 gh
= list_entry(gl
->gl_waiters3
.next
,
619 struct gfs2_holder
, gh_list
);
621 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
622 blocked
= rq_promote(gh
);
624 gfs2_assert_warn(gl
->gl_sbd
, 0);
635 * gfs2_glmutex_lock - acquire a local lock on a glock
638 * Gives caller exclusive access to manipulate a glock structure.
641 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
643 struct gfs2_holder gh
;
645 gfs2_holder_init(gl
, 0, 0, &gh
);
646 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
648 spin_lock(&gl
->gl_spin
);
649 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
650 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
652 gl
->gl_owner
= current
;
653 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
654 complete(&gh
.gh_wait
);
656 spin_unlock(&gl
->gl_spin
);
658 wait_for_completion(&gh
.gh_wait
);
659 gfs2_holder_uninit(&gh
);
663 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
666 * Returns: 1 if the glock is acquired
669 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
673 spin_lock(&gl
->gl_spin
);
674 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
677 gl
->gl_owner
= current
;
678 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
680 spin_unlock(&gl
->gl_spin
);
686 * gfs2_glmutex_unlock - release a local lock on a glock
691 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
693 spin_lock(&gl
->gl_spin
);
694 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
698 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
699 spin_unlock(&gl
->gl_spin
);
703 * handle_callback - add a demote request to a lock's queue
705 * @state: the state the caller wants us to change to
707 * Note: This may fail sliently if we are out of memory.
710 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
712 struct gfs2_holder
*gh
, *new_gh
= NULL
;
715 spin_lock(&gl
->gl_spin
);
717 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
718 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
719 gl
->gl_req_gh
!= gh
) {
720 if (gh
->gh_state
!= state
)
721 gh
->gh_state
= LM_ST_UNLOCKED
;
727 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
730 spin_unlock(&gl
->gl_spin
);
732 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_KERNEL
);
735 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
736 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
742 spin_unlock(&gl
->gl_spin
);
745 gfs2_holder_put(new_gh
);
748 void gfs2_glock_inode_squish(struct inode
*inode
)
750 struct gfs2_holder gh
;
751 struct gfs2_glock
*gl
= GFS2_I(inode
)->i_gl
;
752 gfs2_holder_init(gl
, LM_ST_UNLOCKED
, 0, &gh
);
753 set_bit(HIF_DEMOTE
, &gh
.gh_iflags
);
754 spin_lock(&gl
->gl_spin
);
755 gfs2_assert(inode
->i_sb
->s_fs_info
, list_empty(&gl
->gl_holders
));
756 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters2
);
758 spin_unlock(&gl
->gl_spin
);
759 wait_for_completion(&gh
.gh_wait
);
760 gfs2_holder_uninit(&gh
);
764 * state_change - record that the glock is now in a different state
766 * @new_state the new state
770 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
774 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
775 held2
= (new_state
!= LM_ST_UNLOCKED
);
777 if (held1
!= held2
) {
784 gl
->gl_state
= new_state
;
788 * xmote_bh - Called after the lock module is done acquiring a lock
789 * @gl: The glock in question
790 * @ret: the int returned from the lock module
794 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
796 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
797 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
798 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
799 int prev_state
= gl
->gl_state
;
802 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
803 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
804 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
806 state_change(gl
, ret
& LM_OUT_ST_MASK
);
808 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
810 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
811 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
812 /* We might not want to do this here.
813 Look at moving to the inode glops. */
815 glops
->go_inval(gl
, DIO_DATA
);
818 /* Deal with each possible exit condition */
821 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
);
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
);
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
&& glops
->go_sync
)
917 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
920 gl
->gl_req_bh
= xmote_bh
;
922 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
, lck_flags
);
924 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
927 if (lck_ret
& LM_OUT_ASYNC
)
928 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
930 xmote_bh(gl
, lck_ret
);
934 * drop_bh - Called after a lock module unlock completes
936 * @ret: the return status
938 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
939 * Doesn't drop the reference on the glock the top half took out
943 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
945 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
946 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
947 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
949 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
951 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
952 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
953 gfs2_assert_warn(sdp
, !ret
);
955 state_change(gl
, LM_ST_UNLOCKED
);
958 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
961 spin_lock(&gl
->gl_spin
);
962 list_del_init(&gh
->gh_list
);
964 spin_unlock(&gl
->gl_spin
);
967 if (glops
->go_drop_bh
)
968 glops
->go_drop_bh(gl
);
970 spin_lock(&gl
->gl_spin
);
971 gl
->gl_req_gh
= NULL
;
972 gl
->gl_req_bh
= NULL
;
973 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
975 spin_unlock(&gl
->gl_spin
);
980 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
983 complete(&gh
->gh_wait
);
988 * gfs2_glock_drop_th - call into the lock module to unlock a lock
993 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
995 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
996 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
999 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1000 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1001 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1003 if (gl
->gl_state
== LM_ST_EXCLUSIVE
&& glops
->go_sync
)
1004 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1006 gfs2_glock_hold(gl
);
1007 gl
->gl_req_bh
= drop_bh
;
1009 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1011 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1017 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1021 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1022 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1024 * Don't cancel GL_NOCANCEL requests.
1027 static void do_cancels(struct gfs2_holder
*gh
)
1029 struct gfs2_glock
*gl
= gh
->gh_gl
;
1031 spin_lock(&gl
->gl_spin
);
1033 while (gl
->gl_req_gh
!= gh
&&
1034 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1035 !list_empty(&gh
->gh_list
)) {
1036 if (gl
->gl_req_bh
&& !(gl
->gl_req_gh
&&
1037 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1038 spin_unlock(&gl
->gl_spin
);
1039 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1041 spin_lock(&gl
->gl_spin
);
1043 spin_unlock(&gl
->gl_spin
);
1045 spin_lock(&gl
->gl_spin
);
1049 spin_unlock(&gl
->gl_spin
);
1053 * glock_wait_internal - wait on a glock acquisition
1054 * @gh: the glock holder
1056 * Returns: 0 on success
1059 static int glock_wait_internal(struct gfs2_holder
*gh
)
1061 struct gfs2_glock
*gl
= gh
->gh_gl
;
1062 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1063 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1065 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1068 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1069 spin_lock(&gl
->gl_spin
);
1070 if (gl
->gl_req_gh
!= gh
&&
1071 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1072 !list_empty(&gh
->gh_list
)) {
1073 list_del_init(&gh
->gh_list
);
1074 gh
->gh_error
= GLR_TRYFAILED
;
1076 spin_unlock(&gl
->gl_spin
);
1077 return gh
->gh_error
;
1079 spin_unlock(&gl
->gl_spin
);
1082 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1085 wait_for_completion(&gh
->gh_wait
);
1088 return gh
->gh_error
;
1090 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1091 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1095 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1096 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1098 if (glops
->go_lock
) {
1099 gh
->gh_error
= glops
->go_lock(gh
);
1101 spin_lock(&gl
->gl_spin
);
1102 list_del_init(&gh
->gh_list
);
1103 spin_unlock(&gl
->gl_spin
);
1107 spin_lock(&gl
->gl_spin
);
1108 gl
->gl_req_gh
= NULL
;
1109 gl
->gl_req_bh
= NULL
;
1110 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1112 spin_unlock(&gl
->gl_spin
);
1115 return gh
->gh_error
;
1118 static inline struct gfs2_holder
*
1119 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1121 struct gfs2_holder
*gh
;
1123 list_for_each_entry(gh
, head
, gh_list
) {
1124 if (gh
->gh_owner
== owner
)
1132 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1133 * @gh: the holder structure to add
1137 static void add_to_queue(struct gfs2_holder
*gh
)
1139 struct gfs2_glock
*gl
= gh
->gh_gl
;
1140 struct gfs2_holder
*existing
;
1142 BUG_ON(!gh
->gh_owner
);
1144 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1146 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1147 printk(KERN_INFO
"pid : %d\n", existing
->gh_owner
->pid
);
1148 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1149 existing
->gh_gl
->gl_name
.ln_type
, existing
->gh_gl
->gl_state
);
1150 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1151 printk(KERN_INFO
"pid : %d\n", gh
->gh_owner
->pid
);
1152 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1153 gl
->gl_name
.ln_type
, gl
->gl_state
);
1157 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1159 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1160 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1164 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1165 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1167 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1171 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1172 * @gh: the holder structure
1174 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1176 * Returns: 0, GLR_TRYFAILED, or errno on failure
1179 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1181 struct gfs2_glock
*gl
= gh
->gh_gl
;
1182 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1186 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1187 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1191 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1193 spin_lock(&gl
->gl_spin
);
1196 spin_unlock(&gl
->gl_spin
);
1198 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1199 error
= glock_wait_internal(gh
);
1200 if (error
== GLR_CANCELED
) {
1206 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1208 if (error
== GLR_TRYFAILED
&& (gh
->gh_flags
& GL_DUMP
))
1215 * gfs2_glock_poll - poll to see if an async request has been completed
1218 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1221 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1223 struct gfs2_glock
*gl
= gh
->gh_gl
;
1226 spin_lock(&gl
->gl_spin
);
1228 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1230 else if (list_empty(&gh
->gh_list
)) {
1231 if (gh
->gh_error
== GLR_CANCELED
) {
1232 spin_unlock(&gl
->gl_spin
);
1234 if (gfs2_glock_nq(gh
))
1241 spin_unlock(&gl
->gl_spin
);
1247 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1248 * @gh: the holder structure
1250 * Returns: 0, GLR_TRYFAILED, or errno on failure
1253 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1257 error
= glock_wait_internal(gh
);
1258 if (error
== GLR_CANCELED
) {
1260 gh
->gh_flags
&= ~GL_ASYNC
;
1261 error
= gfs2_glock_nq(gh
);
1268 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1269 * @gh: the glock holder
1273 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1275 struct gfs2_glock
*gl
= gh
->gh_gl
;
1276 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1278 if (gh
->gh_flags
& GL_NOCACHE
)
1279 handle_callback(gl
, LM_ST_UNLOCKED
);
1281 gfs2_glmutex_lock(gl
);
1283 spin_lock(&gl
->gl_spin
);
1284 list_del_init(&gh
->gh_list
);
1286 if (list_empty(&gl
->gl_holders
)) {
1287 spin_unlock(&gl
->gl_spin
);
1289 if (glops
->go_unlock
)
1290 glops
->go_unlock(gh
);
1292 gl
->gl_stamp
= jiffies
;
1294 spin_lock(&gl
->gl_spin
);
1297 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1299 spin_unlock(&gl
->gl_spin
);
1303 * gfs2_glock_prefetch - Try to prefetch a glock
1305 * @state: the state to prefetch in
1306 * @flags: flags passed to go_xmote_th()
1310 static void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
,
1313 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1315 spin_lock(&gl
->gl_spin
);
1317 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) || !list_empty(&gl
->gl_holders
) ||
1318 !list_empty(&gl
->gl_waiters1
) || !list_empty(&gl
->gl_waiters2
) ||
1319 !list_empty(&gl
->gl_waiters3
) ||
1320 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1321 spin_unlock(&gl
->gl_spin
);
1325 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1326 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1327 spin_unlock(&gl
->gl_spin
);
1329 glops
->go_xmote_th(gl
, state
, flags
);
1332 static void greedy_work(void *data
)
1334 struct greedy
*gr
= data
;
1335 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1336 struct gfs2_glock
*gl
= gh
->gh_gl
;
1337 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1339 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1341 if (glops
->go_greedy
)
1342 glops
->go_greedy(gl
);
1344 spin_lock(&gl
->gl_spin
);
1346 if (list_empty(&gl
->gl_waiters2
)) {
1347 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1348 spin_unlock(&gl
->gl_spin
);
1349 gfs2_holder_uninit(gh
);
1352 gfs2_glock_hold(gl
);
1353 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1355 spin_unlock(&gl
->gl_spin
);
1361 * gfs2_glock_be_greedy -
1365 * Returns: 0 if go_greedy will be called, 1 otherwise
1368 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1371 struct gfs2_holder
*gh
;
1373 if (!time
|| gl
->gl_sbd
->sd_args
.ar_localcaching
||
1374 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1377 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1379 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1384 gfs2_holder_init(gl
, 0, 0, gh
);
1385 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1386 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1388 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1389 schedule_delayed_work(&gr
->gr_work
, time
);
1395 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1396 * @gh: the holder structure
1400 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1403 gfs2_holder_uninit(gh
);
1407 * gfs2_glock_nq_num - acquire a glock based on lock number
1408 * @sdp: the filesystem
1409 * @number: the lock number
1410 * @glops: the glock operations for the type of glock
1411 * @state: the state to acquire the glock in
1412 * @flags: modifier flags for the aquisition
1413 * @gh: the struct gfs2_holder
1418 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1419 const struct gfs2_glock_operations
*glops
,
1420 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1422 struct gfs2_glock
*gl
;
1425 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1427 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1435 * glock_compare - Compare two struct gfs2_glock structures for sorting
1436 * @arg_a: the first structure
1437 * @arg_b: the second structure
1441 static int glock_compare(const void *arg_a
, const void *arg_b
)
1443 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1444 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1445 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1446 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1449 if (a
->ln_number
> b
->ln_number
)
1451 else if (a
->ln_number
< b
->ln_number
)
1454 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1455 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1457 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1458 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1466 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1467 * @num_gh: the number of structures
1468 * @ghs: an array of struct gfs2_holder structures
1470 * Returns: 0 on success (all glocks acquired),
1471 * errno on failure (no glocks acquired)
1474 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1475 struct gfs2_holder
**p
)
1480 for (x
= 0; x
< num_gh
; x
++)
1483 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1485 for (x
= 0; x
< num_gh
; x
++) {
1486 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1488 error
= gfs2_glock_nq(p
[x
]);
1491 gfs2_glock_dq(p
[x
]);
1500 * gfs2_glock_nq_m - acquire multiple glocks
1501 * @num_gh: the number of structures
1502 * @ghs: an array of struct gfs2_holder structures
1504 * Figure out how big an impact this function has. Either:
1505 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1506 * 2) Forget async stuff and just call nq_m_sync()
1507 * 3) Leave it like it is
1509 * Returns: 0 on success (all glocks acquired),
1510 * errno on failure (no glocks acquired)
1513 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1517 int borked
= 0, serious
= 0;
1524 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1525 return gfs2_glock_nq(ghs
);
1528 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1532 for (x
= 0; x
< num_gh
; x
++) {
1533 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1534 error
= gfs2_glock_nq(&ghs
[x
]);
1543 for (x
= 0; x
< num_gh
; x
++) {
1544 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1547 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1557 for (x
= 0; x
< num_gh
; x
++)
1559 gfs2_glock_dq(&ghs
[x
]);
1564 for (x
= 0; x
< num_gh
; x
++)
1565 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1567 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1576 * gfs2_glock_dq_m - release multiple glocks
1577 * @num_gh: the number of structures
1578 * @ghs: an array of struct gfs2_holder structures
1582 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1586 for (x
= 0; x
< num_gh
; x
++)
1587 gfs2_glock_dq(&ghs
[x
]);
1591 * gfs2_glock_dq_uninit_m - release multiple glocks
1592 * @num_gh: the number of structures
1593 * @ghs: an array of struct gfs2_holder structures
1597 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1601 for (x
= 0; x
< num_gh
; x
++)
1602 gfs2_glock_dq_uninit(&ghs
[x
]);
1606 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1607 * @sdp: the filesystem
1608 * @number: the lock number
1609 * @glops: the glock operations for the type of glock
1610 * @state: the state to acquire the glock in
1611 * @flags: modifier flags for the aquisition
1616 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1617 const struct gfs2_glock_operations
*glops
,
1618 unsigned int state
, int flags
)
1620 struct gfs2_glock
*gl
;
1623 if (atomic_read(&sdp
->sd_reclaim_count
) <
1624 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1625 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1627 gfs2_glock_prefetch(gl
, state
, flags
);
1634 * gfs2_lvb_hold - attach a LVB from a glock
1635 * @gl: The glock in question
1639 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1643 gfs2_glmutex_lock(gl
);
1645 if (!atomic_read(&gl
->gl_lvb_count
)) {
1646 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1648 gfs2_glmutex_unlock(gl
);
1651 gfs2_glock_hold(gl
);
1653 atomic_inc(&gl
->gl_lvb_count
);
1655 gfs2_glmutex_unlock(gl
);
1661 * gfs2_lvb_unhold - detach a LVB from a glock
1662 * @gl: The glock in question
1666 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1668 gfs2_glock_hold(gl
);
1669 gfs2_glmutex_lock(gl
);
1671 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1672 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1673 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1678 gfs2_glmutex_unlock(gl
);
1682 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1685 struct gfs2_glock
*gl
;
1687 gl
= gfs2_glock_find(sdp
, name
);
1691 if (gl
->gl_ops
->go_callback
)
1692 gl
->gl_ops
->go_callback(gl
, state
);
1693 handle_callback(gl
, state
);
1695 spin_lock(&gl
->gl_spin
);
1697 spin_unlock(&gl
->gl_spin
);
1703 * gfs2_glock_cb - Callback used by locking module
1704 * @fsdata: Pointer to the superblock
1705 * @type: Type of callback
1706 * @data: Type dependent data pointer
1708 * Called by the locking module when it wants to tell us something.
1709 * Either we need to drop a lock, one of our ASYNC requests completed, or
1710 * a journal from another client needs to be recovered.
1713 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1715 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1719 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1723 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1727 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1731 struct lm_async_cb
*async
= data
;
1732 struct gfs2_glock
*gl
;
1734 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1735 if (gfs2_assert_warn(sdp
, gl
))
1737 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1738 gl
->gl_req_bh(gl
, async
->lc_ret
);
1743 case LM_CB_NEED_RECOVERY
:
1744 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1745 if (sdp
->sd_recoverd_process
)
1746 wake_up_process(sdp
->sd_recoverd_process
);
1749 case LM_CB_DROPLOCKS
:
1750 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1751 gfs2_quota_scan(sdp
);
1755 gfs2_assert_warn(sdp
, 0);
1761 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1762 * iopen glock from memory
1763 * @io_gl: the iopen glock
1764 * @state: the state into which the glock should be put
1768 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1771 if (state
!= LM_ST_UNLOCKED
)
1773 /* FIXME: remove this? */
1777 * demote_ok - Check to see if it's ok to unlock a glock
1780 * Returns: 1 if it's ok
1783 static int demote_ok(struct gfs2_glock
*gl
)
1785 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1786 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1789 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1791 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
1792 demote
= time_after_eq(jiffies
, gl
->gl_stamp
+
1793 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
1794 else if (glops
->go_demote_ok
)
1795 demote
= glops
->go_demote_ok(gl
);
1801 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1806 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1808 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1810 spin_lock(&sdp
->sd_reclaim_lock
);
1811 if (list_empty(&gl
->gl_reclaim
)) {
1812 gfs2_glock_hold(gl
);
1813 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1814 atomic_inc(&sdp
->sd_reclaim_count
);
1816 spin_unlock(&sdp
->sd_reclaim_lock
);
1818 wake_up(&sdp
->sd_reclaim_wq
);
1822 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1823 * @sdp: the filesystem
1825 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1826 * different glock and we notice that there are a lot of glocks in the
1831 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1833 struct gfs2_glock
*gl
;
1835 spin_lock(&sdp
->sd_reclaim_lock
);
1836 if (list_empty(&sdp
->sd_reclaim_list
)) {
1837 spin_unlock(&sdp
->sd_reclaim_lock
);
1840 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1841 struct gfs2_glock
, gl_reclaim
);
1842 list_del_init(&gl
->gl_reclaim
);
1843 spin_unlock(&sdp
->sd_reclaim_lock
);
1845 atomic_dec(&sdp
->sd_reclaim_count
);
1846 atomic_inc(&sdp
->sd_reclaimed
);
1848 if (gfs2_glmutex_trylock(gl
)) {
1849 if (queue_empty(gl
, &gl
->gl_holders
) &&
1850 gl
->gl_state
!= LM_ST_UNLOCKED
&& demote_ok(gl
))
1851 handle_callback(gl
, LM_ST_UNLOCKED
);
1852 gfs2_glmutex_unlock(gl
);
1859 * examine_bucket - Call a function for glock in a hash bucket
1860 * @examiner: the function
1861 * @sdp: the filesystem
1862 * @bucket: the bucket
1864 * Returns: 1 if the bucket has entries
1867 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1868 struct gfs2_gl_hash_bucket
*bucket
)
1870 struct glock_plug plug
;
1871 struct list_head
*tmp
;
1872 struct gfs2_glock
*gl
;
1875 /* Add "plug" to end of bucket list, work back up list from there */
1876 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
1877 set_bit(GLF_PLUG
, &plug
.gl_flags
);
1879 write_lock(&bucket
->hb_lock
);
1880 list_add(&plug
.gl_list
, &bucket
->hb_list
);
1881 write_unlock(&bucket
->hb_lock
);
1884 write_lock(&bucket
->hb_lock
);
1887 tmp
= plug
.gl_list
.next
;
1889 if (tmp
== &bucket
->hb_list
) {
1890 list_del(&plug
.gl_list
);
1891 entries
= !list_empty(&bucket
->hb_list
);
1892 write_unlock(&bucket
->hb_lock
);
1895 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
1897 /* Move plug up list */
1898 list_move(&plug
.gl_list
, &gl
->gl_list
);
1900 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
1903 /* examiner() must glock_put() */
1904 gfs2_glock_hold(gl
);
1909 write_unlock(&bucket
->hb_lock
);
1916 * scan_glock - look at a glock and see if we can reclaim it
1917 * @gl: the glock to look at
1921 static void scan_glock(struct gfs2_glock
*gl
)
1923 if (gl
->gl_ops
== &gfs2_inode_glops
)
1926 if (gfs2_glmutex_trylock(gl
)) {
1927 if (queue_empty(gl
, &gl
->gl_holders
) &&
1928 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1931 gfs2_glmutex_unlock(gl
);
1938 gfs2_glmutex_unlock(gl
);
1939 gfs2_glock_schedule_for_reclaim(gl
);
1944 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1945 * @sdp: the filesystem
1949 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1953 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1954 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
1960 * clear_glock - look at a glock and see if we can free it from glock cache
1961 * @gl: the glock to look at
1965 static void clear_glock(struct gfs2_glock
*gl
)
1967 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1970 spin_lock(&sdp
->sd_reclaim_lock
);
1971 if (!list_empty(&gl
->gl_reclaim
)) {
1972 list_del_init(&gl
->gl_reclaim
);
1973 atomic_dec(&sdp
->sd_reclaim_count
);
1974 spin_unlock(&sdp
->sd_reclaim_lock
);
1975 released
= gfs2_glock_put(gl
);
1976 gfs2_assert(sdp
, !released
);
1978 spin_unlock(&sdp
->sd_reclaim_lock
);
1981 if (gfs2_glmutex_trylock(gl
)) {
1982 if (queue_empty(gl
, &gl
->gl_holders
) &&
1983 gl
->gl_state
!= LM_ST_UNLOCKED
)
1984 handle_callback(gl
, LM_ST_UNLOCKED
);
1986 gfs2_glmutex_unlock(gl
);
1993 * gfs2_gl_hash_clear - Empty out the glock hash table
1994 * @sdp: the filesystem
1995 * @wait: wait until it's all gone
1997 * Called when unmounting the filesystem, or when inter-node lock manager
1998 * requests DROPLOCKS because it is running out of capacity.
2001 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2012 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2013 if (examine_bucket(clear_glock
, sdp
, &sdp
->sd_gl_hash
[x
]))
2019 if (time_after_eq(jiffies
,
2020 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2021 fs_warn(sdp
, "Unmount seems to be stalled. "
2022 "Dumping lock state...\n");
2023 gfs2_dump_lockstate(sdp
);
2027 invalidate_inodes(sdp
->sd_vfs
);
2033 * Diagnostic routines to help debug distributed deadlock
2037 * dump_holder - print information about a glock holder
2038 * @str: a string naming the type of holder
2039 * @gh: the glock holder
2041 * Returns: 0 on success, -ENOBUFS when we run out of space
2044 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2047 int error
= -ENOBUFS
;
2049 printk(KERN_INFO
" %s\n", str
);
2050 printk(KERN_INFO
" owner = %ld\n",
2051 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2052 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2053 printk(KERN_INFO
" gh_flags =");
2054 for (x
= 0; x
< 32; x
++)
2055 if (gh
->gh_flags
& (1 << x
))
2058 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2059 printk(KERN_INFO
" gh_iflags =");
2060 for (x
= 0; x
< 32; x
++)
2061 if (test_bit(x
, &gh
->gh_iflags
))
2064 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2072 * dump_inode - print information about an inode
2075 * Returns: 0 on success, -ENOBUFS when we run out of space
2078 static int dump_inode(struct gfs2_inode
*ip
)
2081 int error
= -ENOBUFS
;
2083 printk(KERN_INFO
" Inode:\n");
2084 printk(KERN_INFO
" num = %llu %llu\n",
2085 (unsigned long long)ip
->i_num
.no_formal_ino
,
2086 (unsigned long long)ip
->i_num
.no_addr
);
2087 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2088 printk(KERN_INFO
" i_flags =");
2089 for (x
= 0; x
< 32; x
++)
2090 if (test_bit(x
, &ip
->i_flags
))
2100 * dump_glock - print information about a glock
2102 * @count: where we are in the buffer
2104 * Returns: 0 on success, -ENOBUFS when we run out of space
2107 static int dump_glock(struct gfs2_glock
*gl
)
2109 struct gfs2_holder
*gh
;
2111 int error
= -ENOBUFS
;
2113 spin_lock(&gl
->gl_spin
);
2115 printk(KERN_INFO
"Glock 0x%p (%u, %llu)\n",
2117 gl
->gl_name
.ln_type
,
2118 (unsigned long long)gl
->gl_name
.ln_number
);
2119 printk(KERN_INFO
" gl_flags =");
2120 for (x
= 0; x
< 32; x
++)
2121 if (test_bit(x
, &gl
->gl_flags
))
2124 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2125 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2126 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
2127 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
2128 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2129 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2130 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2131 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2132 printk(KERN_INFO
" le = %s\n",
2133 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2134 printk(KERN_INFO
" reclaim = %s\n",
2135 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2137 printk(KERN_INFO
" aspace = 0x%p nrpages = %lu\n",
2139 gl
->gl_aspace
->i_mapping
->nrpages
);
2141 printk(KERN_INFO
" aspace = no\n");
2142 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2143 if (gl
->gl_req_gh
) {
2144 error
= dump_holder("Request", gl
->gl_req_gh
);
2148 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2149 error
= dump_holder("Holder", gh
);
2153 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2154 error
= dump_holder("Waiter1", gh
);
2158 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2159 error
= dump_holder("Waiter2", gh
);
2163 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2164 error
= dump_holder("Waiter3", gh
);
2168 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2169 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2170 list_empty(&gl
->gl_holders
)) {
2171 error
= dump_inode(gl
->gl_object
);
2176 printk(KERN_INFO
" Inode: busy\n");
2183 spin_unlock(&gl
->gl_spin
);
2188 * gfs2_dump_lockstate - print out the current lockstate
2189 * @sdp: the filesystem
2190 * @ub: the buffer to copy the information into
2192 * If @ub is NULL, dump the lockstate to the console.
2196 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2198 struct gfs2_gl_hash_bucket
*bucket
;
2199 struct gfs2_glock
*gl
;
2203 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2204 bucket
= &sdp
->sd_gl_hash
[x
];
2206 read_lock(&bucket
->hb_lock
);
2208 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2209 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2212 error
= dump_glock(gl
);
2217 read_unlock(&bucket
->hb_lock
);
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