2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License v.2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/delay.h>
16 #include <linux/sort.h>
17 #include <linux/jhash.h>
18 #include <linux/kref.h>
19 #include <linux/kallsyms.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <asm/uaccess.h>
24 #include "lm_interface.h"
36 /* Must be kept in sync with the beginning of struct gfs2_glock */
38 struct list_head gl_list
;
39 unsigned long gl_flags
;
43 struct gfs2_holder gr_gh
;
44 struct work_struct gr_work
;
47 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
49 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
50 static int dump_glock(struct gfs2_glock
*gl
);
53 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
54 * @actual: the current state of the lock
55 * @requested: the lock state that was requested by the caller
56 * @flags: the modifier flags passed in by the caller
58 * Returns: 1 if the locks are compatible, 0 otherwise
61 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
64 if (actual
== requested
)
70 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
73 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
80 * gl_hash() - Turn glock number into hash bucket number
81 * @lock: The glock number
83 * Returns: The number of the corresponding hash bucket
86 static unsigned int gl_hash(struct lm_lockname
*name
)
90 h
= jhash(&name
->ln_number
, sizeof(uint64_t), 0);
91 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
92 h
&= GFS2_GL_HASH_MASK
;
98 * glock_free() - Perform a few checks and then release struct gfs2_glock
99 * @gl: The glock to release
101 * Also calls lock module to release its internal structure for this glock.
105 static void glock_free(struct gfs2_glock
*gl
)
107 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
108 struct inode
*aspace
= gl
->gl_aspace
;
110 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
113 gfs2_aspace_put(aspace
);
115 kmem_cache_free(gfs2_glock_cachep
, gl
);
119 * gfs2_glock_hold() - increment reference count on glock
120 * @gl: The glock to hold
124 void gfs2_glock_hold(struct gfs2_glock
*gl
)
126 kref_get(&gl
->gl_ref
);
129 /* All work is done after the return from kref_put() so we
130 can release the write_lock before the free. */
132 static void kill_glock(struct kref
*kref
)
134 struct gfs2_glock
*gl
= container_of(kref
, struct gfs2_glock
, gl_ref
);
135 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
137 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
138 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
139 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
140 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
141 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
142 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
146 * gfs2_glock_put() - Decrement reference count on glock
147 * @gl: The glock to put
151 int gfs2_glock_put(struct gfs2_glock
*gl
)
153 struct gfs2_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 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 struct lm_lockname
*name
)
232 struct gfs2_gl_hash_bucket
*bucket
= &sdp
->sd_gl_hash
[gl_hash(name
)];
233 struct gfs2_glock
*gl
;
235 read_lock(&bucket
->hb_lock
);
236 gl
= search_bucket(bucket
, name
);
237 read_unlock(&bucket
->hb_lock
);
243 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
244 * @sdp: The GFS2 superblock
245 * @number: the lock number
246 * @glops: The glock_operations to use
247 * @create: If 0, don't create the glock if it doesn't exist
248 * @glp: the glock is returned here
250 * This does not lock a glock, just finds/creates structures for one.
255 int gfs2_glock_get(struct gfs2_sbd
*sdp
, uint64_t number
,
256 struct gfs2_glock_operations
*glops
, int create
,
257 struct gfs2_glock
**glp
)
259 struct lm_lockname name
;
260 struct gfs2_glock
*gl
, *tmp
;
261 struct gfs2_gl_hash_bucket
*bucket
;
264 name
.ln_number
= number
;
265 name
.ln_type
= glops
->go_type
;
266 bucket
= &sdp
->sd_gl_hash
[gl_hash(&name
)];
268 read_lock(&bucket
->hb_lock
);
269 gl
= search_bucket(bucket
, &name
);
270 read_unlock(&bucket
->hb_lock
);
277 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
281 memset(gl
, 0, sizeof(struct gfs2_glock
));
283 INIT_LIST_HEAD(&gl
->gl_list
);
285 kref_init(&gl
->gl_ref
);
287 spin_lock_init(&gl
->gl_spin
);
289 gl
->gl_state
= LM_ST_UNLOCKED
;
292 INIT_LIST_HEAD(&gl
->gl_holders
);
293 INIT_LIST_HEAD(&gl
->gl_waiters1
);
294 INIT_LIST_HEAD(&gl
->gl_waiters2
);
295 INIT_LIST_HEAD(&gl
->gl_waiters3
);
299 gl
->gl_bucket
= bucket
;
300 INIT_LIST_HEAD(&gl
->gl_reclaim
);
304 lops_init_le(&gl
->gl_le
, &gfs2_glock_lops
);
305 INIT_LIST_HEAD(&gl
->gl_ail_list
);
307 /* If this glock protects actual on-disk data or metadata blocks,
308 create a VFS inode to manage the pages/buffers holding them. */
309 if (glops
== &gfs2_inode_glops
||
310 glops
== &gfs2_rgrp_glops
) {
311 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
312 if (!gl
->gl_aspace
) {
318 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
322 write_lock(&bucket
->hb_lock
);
323 tmp
= search_bucket(bucket
, &name
);
325 write_unlock(&bucket
->hb_lock
);
329 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
330 write_unlock(&bucket
->hb_lock
);
339 gfs2_aspace_put(gl
->gl_aspace
);
342 kmem_cache_free(gfs2_glock_cachep
, gl
);
348 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
350 * @state: the state we're requesting
351 * @flags: the modifier flags
352 * @gh: the holder structure
356 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
357 struct gfs2_holder
*gh
)
359 INIT_LIST_HEAD(&gh
->gh_list
);
361 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
362 gh
->gh_owner
= current
;
363 gh
->gh_state
= state
;
364 gh
->gh_flags
= flags
;
367 init_completion(&gh
->gh_wait
);
369 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
370 gh
->gh_flags
|= GL_LOCAL_EXCL
;
376 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
377 * @state: the state we're requesting
378 * @flags: the modifier flags
379 * @gh: the holder structure
381 * Don't mess with the glock.
385 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
387 gh
->gh_state
= state
;
388 gh
->gh_flags
= flags
;
389 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
390 gh
->gh_flags
|= GL_LOCAL_EXCL
;
392 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
393 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
397 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
398 * @gh: the holder structure
402 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
404 gfs2_glock_put(gh
->gh_gl
);
410 * gfs2_holder_get - get a struct gfs2_holder structure
412 * @state: the state we're requesting
413 * @flags: the modifier flags
416 * Figure out how big an impact this function has. Either:
417 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
418 * 2) Leave it like it is
420 * Returns: the holder structure, NULL on ENOMEM
423 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
425 int flags
, gfp_t gfp_flags
)
427 struct gfs2_holder
*gh
;
429 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
433 gfs2_holder_init(gl
, state
, flags
, gh
);
434 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
435 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
440 * gfs2_holder_put - get rid of a struct gfs2_holder structure
441 * @gh: the holder structure
445 static void gfs2_holder_put(struct gfs2_holder
*gh
)
447 gfs2_holder_uninit(gh
);
452 * rq_mutex - process a mutex request in the queue
453 * @gh: the glock holder
455 * Returns: 1 if the queue is blocked
458 static int rq_mutex(struct gfs2_holder
*gh
)
460 struct gfs2_glock
*gl
= gh
->gh_gl
;
462 list_del_init(&gh
->gh_list
);
463 /* gh->gh_error never examined. */
464 set_bit(GLF_LOCK
, &gl
->gl_flags
);
465 complete(&gh
->gh_wait
);
471 * rq_promote - process a promote request in the queue
472 * @gh: the glock holder
474 * Acquire a new inter-node lock, or change a lock state to more restrictive.
476 * Returns: 1 if the queue is blocked
479 static int rq_promote(struct gfs2_holder
*gh
)
481 struct gfs2_glock
*gl
= gh
->gh_gl
;
482 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
483 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
485 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
486 if (list_empty(&gl
->gl_holders
)) {
488 set_bit(GLF_LOCK
, &gl
->gl_flags
);
489 spin_unlock(&gl
->gl_spin
);
491 if (atomic_read(&sdp
->sd_reclaim_count
) >
492 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
493 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
494 gfs2_reclaim_glock(sdp
);
495 gfs2_reclaim_glock(sdp
);
498 glops
->go_xmote_th(gl
, gh
->gh_state
,
501 spin_lock(&gl
->gl_spin
);
506 if (list_empty(&gl
->gl_holders
)) {
507 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
508 set_bit(GLF_LOCK
, &gl
->gl_flags
);
510 struct gfs2_holder
*next_gh
;
511 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
513 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
515 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
519 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
521 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
523 complete(&gh
->gh_wait
);
529 * rq_demote - process a demote request in the queue
530 * @gh: the glock holder
532 * Returns: 1 if the queue is blocked
535 static int rq_demote(struct gfs2_holder
*gh
)
537 struct gfs2_glock
*gl
= gh
->gh_gl
;
538 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
540 if (!list_empty(&gl
->gl_holders
))
543 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
544 list_del_init(&gh
->gh_list
);
546 spin_unlock(&gl
->gl_spin
);
547 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
550 complete(&gh
->gh_wait
);
551 spin_lock(&gl
->gl_spin
);
554 set_bit(GLF_LOCK
, &gl
->gl_flags
);
555 spin_unlock(&gl
->gl_spin
);
557 if (gh
->gh_state
== LM_ST_UNLOCKED
||
558 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
559 glops
->go_drop_th(gl
);
561 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
563 spin_lock(&gl
->gl_spin
);
570 * rq_greedy - process a queued request to drop greedy status
571 * @gh: the glock holder
573 * Returns: 1 if the queue is blocked
576 static int rq_greedy(struct gfs2_holder
*gh
)
578 struct gfs2_glock
*gl
= gh
->gh_gl
;
580 list_del_init(&gh
->gh_list
);
581 /* gh->gh_error never examined. */
582 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
583 spin_unlock(&gl
->gl_spin
);
585 gfs2_holder_uninit(gh
);
586 kfree(container_of(gh
, struct greedy
, gr_gh
));
588 spin_lock(&gl
->gl_spin
);
594 * run_queue - process holder structures on a glock
598 static void run_queue(struct gfs2_glock
*gl
)
600 struct gfs2_holder
*gh
;
604 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
607 if (!list_empty(&gl
->gl_waiters1
)) {
608 gh
= list_entry(gl
->gl_waiters1
.next
,
609 struct gfs2_holder
, gh_list
);
611 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
612 blocked
= rq_mutex(gh
);
614 gfs2_assert_warn(gl
->gl_sbd
, 0);
616 } else if (!list_empty(&gl
->gl_waiters2
) &&
617 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
618 gh
= list_entry(gl
->gl_waiters2
.next
,
619 struct gfs2_holder
, gh_list
);
621 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
622 blocked
= rq_demote(gh
);
623 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
624 blocked
= rq_greedy(gh
);
626 gfs2_assert_warn(gl
->gl_sbd
, 0);
628 } else if (!list_empty(&gl
->gl_waiters3
)) {
629 gh
= list_entry(gl
->gl_waiters3
.next
,
630 struct gfs2_holder
, gh_list
);
632 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
633 blocked
= rq_promote(gh
);
635 gfs2_assert_warn(gl
->gl_sbd
, 0);
646 * gfs2_glmutex_lock - acquire a local lock on a glock
649 * Gives caller exclusive access to manipulate a glock structure.
652 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
654 struct gfs2_holder gh
;
656 gfs2_holder_init(gl
, 0, 0, &gh
);
657 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
659 spin_lock(&gl
->gl_spin
);
660 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
661 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
663 gl
->gl_owner
= current
;
664 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
665 complete(&gh
.gh_wait
);
667 spin_unlock(&gl
->gl_spin
);
669 wait_for_completion(&gh
.gh_wait
);
670 gfs2_holder_uninit(&gh
);
674 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
677 * Returns: 1 if the glock is acquired
680 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
684 spin_lock(&gl
->gl_spin
);
685 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
688 gl
->gl_owner
= current
;
689 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
691 spin_unlock(&gl
->gl_spin
);
697 * gfs2_glmutex_unlock - release a local lock on a glock
702 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
704 spin_lock(&gl
->gl_spin
);
705 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
709 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
710 spin_unlock(&gl
->gl_spin
);
714 * handle_callback - add a demote request to a lock's queue
716 * @state: the state the caller wants us to change to
718 * Note: This may fail sliently if we are out of memory.
721 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
723 struct gfs2_holder
*gh
, *new_gh
= NULL
;
726 spin_lock(&gl
->gl_spin
);
728 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
729 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
730 gl
->gl_req_gh
!= gh
) {
731 if (gh
->gh_state
!= state
)
732 gh
->gh_state
= LM_ST_UNLOCKED
;
738 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
741 spin_unlock(&gl
->gl_spin
);
743 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_KERNEL
);
746 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
747 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
753 spin_unlock(&gl
->gl_spin
);
756 gfs2_holder_put(new_gh
);
759 void gfs2_glock_inode_squish(struct inode
*inode
)
761 struct gfs2_holder gh
;
762 struct gfs2_glock
*gl
= GFS2_I(inode
)->i_gl
;
763 gfs2_holder_init(gl
, LM_ST_UNLOCKED
, 0, &gh
);
764 set_bit(HIF_DEMOTE
, &gh
.gh_iflags
);
765 spin_lock(&gl
->gl_spin
);
766 gfs2_assert(inode
->i_sb
->s_fs_info
, list_empty(&gl
->gl_holders
));
767 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters2
);
769 spin_unlock(&gl
->gl_spin
);
770 wait_for_completion(&gh
.gh_wait
);
771 gfs2_holder_uninit(&gh
);
775 * state_change - record that the glock is now in a different state
777 * @new_state the new state
781 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
785 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
786 held2
= (new_state
!= LM_ST_UNLOCKED
);
788 if (held1
!= held2
) {
795 gl
->gl_state
= new_state
;
799 * xmote_bh - Called after the lock module is done acquiring a lock
800 * @gl: The glock in question
801 * @ret: the int returned from the lock module
805 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
807 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
808 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
809 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
810 int prev_state
= gl
->gl_state
;
813 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
814 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
815 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
817 state_change(gl
, ret
& LM_OUT_ST_MASK
);
819 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
821 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
822 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
823 /* We might not want to do this here.
824 Look at moving to the inode glops. */
826 glops
->go_inval(gl
, DIO_DATA
);
829 /* Deal with each possible exit condition */
832 gl
->gl_stamp
= jiffies
;
834 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
835 spin_lock(&gl
->gl_spin
);
836 list_del_init(&gh
->gh_list
);
838 spin_unlock(&gl
->gl_spin
);
840 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
841 spin_lock(&gl
->gl_spin
);
842 list_del_init(&gh
->gh_list
);
843 if (gl
->gl_state
== gh
->gh_state
||
844 gl
->gl_state
== LM_ST_UNLOCKED
)
847 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
848 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
849 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
850 gh
->gh_error
= GLR_TRYFAILED
;
852 spin_unlock(&gl
->gl_spin
);
854 if (ret
& LM_OUT_CANCELED
)
855 handle_callback(gl
, LM_ST_UNLOCKED
); /* Lame */
857 } else if (ret
& LM_OUT_CANCELED
) {
858 spin_lock(&gl
->gl_spin
);
859 list_del_init(&gh
->gh_list
);
860 gh
->gh_error
= GLR_CANCELED
;
861 spin_unlock(&gl
->gl_spin
);
863 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
864 spin_lock(&gl
->gl_spin
);
865 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
867 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
868 spin_unlock(&gl
->gl_spin
);
870 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
874 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
875 spin_lock(&gl
->gl_spin
);
876 list_del_init(&gh
->gh_list
);
877 gh
->gh_error
= GLR_TRYFAILED
;
878 spin_unlock(&gl
->gl_spin
);
881 if (gfs2_assert_withdraw(sdp
, 0) == -1)
882 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
885 if (glops
->go_xmote_bh
)
886 glops
->go_xmote_bh(gl
);
889 spin_lock(&gl
->gl_spin
);
890 gl
->gl_req_gh
= NULL
;
891 gl
->gl_req_bh
= NULL
;
892 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
894 spin_unlock(&gl
->gl_spin
);
900 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
903 complete(&gh
->gh_wait
);
908 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
909 * @gl: The glock in question
910 * @state: the requested state
911 * @flags: modifier flags to the lock call
915 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
917 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
918 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
919 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
920 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
922 unsigned int lck_ret
;
924 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
925 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
926 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
927 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
929 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
932 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
936 gl
->gl_req_bh
= xmote_bh
;
938 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
,
941 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
944 if (lck_ret
& LM_OUT_ASYNC
)
945 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
947 xmote_bh(gl
, lck_ret
);
951 * drop_bh - Called after a lock module unlock completes
953 * @ret: the return status
955 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
956 * Doesn't drop the reference on the glock the top half took out
960 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
962 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
963 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
964 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
966 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
968 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
969 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
970 gfs2_assert_warn(sdp
, !ret
);
972 state_change(gl
, LM_ST_UNLOCKED
);
975 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
978 spin_lock(&gl
->gl_spin
);
979 list_del_init(&gh
->gh_list
);
981 spin_unlock(&gl
->gl_spin
);
984 if (glops
->go_drop_bh
)
985 glops
->go_drop_bh(gl
);
987 spin_lock(&gl
->gl_spin
);
988 gl
->gl_req_gh
= NULL
;
989 gl
->gl_req_bh
= NULL
;
990 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
992 spin_unlock(&gl
->gl_spin
);
997 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
1000 complete(&gh
->gh_wait
);
1005 * gfs2_glock_drop_th - call into the lock module to unlock a lock
1010 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
1012 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1013 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1016 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1017 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1018 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1020 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1023 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1026 gfs2_glock_hold(gl
);
1027 gl
->gl_req_bh
= drop_bh
;
1029 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1031 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1037 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1041 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1042 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1044 * Don't cancel GL_NOCANCEL requests.
1047 static void do_cancels(struct gfs2_holder
*gh
)
1049 struct gfs2_glock
*gl
= gh
->gh_gl
;
1051 spin_lock(&gl
->gl_spin
);
1053 while (gl
->gl_req_gh
!= gh
&&
1054 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1055 !list_empty(&gh
->gh_list
)) {
1056 if (gl
->gl_req_bh
&&
1058 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1059 spin_unlock(&gl
->gl_spin
);
1060 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1062 spin_lock(&gl
->gl_spin
);
1064 spin_unlock(&gl
->gl_spin
);
1066 spin_lock(&gl
->gl_spin
);
1070 spin_unlock(&gl
->gl_spin
);
1074 * glock_wait_internal - wait on a glock acquisition
1075 * @gh: the glock holder
1077 * Returns: 0 on success
1080 static int glock_wait_internal(struct gfs2_holder
*gh
)
1082 struct gfs2_glock
*gl
= gh
->gh_gl
;
1083 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1084 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1086 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1089 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1090 spin_lock(&gl
->gl_spin
);
1091 if (gl
->gl_req_gh
!= gh
&&
1092 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1093 !list_empty(&gh
->gh_list
)) {
1094 list_del_init(&gh
->gh_list
);
1095 gh
->gh_error
= GLR_TRYFAILED
;
1097 spin_unlock(&gl
->gl_spin
);
1098 return gh
->gh_error
;
1100 spin_unlock(&gl
->gl_spin
);
1103 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1106 wait_for_completion(&gh
->gh_wait
);
1109 return gh
->gh_error
;
1111 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1112 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1116 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1117 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1119 if (glops
->go_lock
) {
1120 gh
->gh_error
= glops
->go_lock(gh
);
1122 spin_lock(&gl
->gl_spin
);
1123 list_del_init(&gh
->gh_list
);
1124 spin_unlock(&gl
->gl_spin
);
1128 spin_lock(&gl
->gl_spin
);
1129 gl
->gl_req_gh
= NULL
;
1130 gl
->gl_req_bh
= NULL
;
1131 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1133 spin_unlock(&gl
->gl_spin
);
1136 return gh
->gh_error
;
1139 static inline struct gfs2_holder
*
1140 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1142 struct gfs2_holder
*gh
;
1144 list_for_each_entry(gh
, head
, gh_list
) {
1145 if (gh
->gh_owner
== owner
)
1153 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1154 * @gh: the holder structure to add
1158 static void add_to_queue(struct gfs2_holder
*gh
)
1160 struct gfs2_glock
*gl
= gh
->gh_gl
;
1161 struct gfs2_holder
*existing
;
1163 BUG_ON(!gh
->gh_owner
);
1165 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1167 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1168 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1172 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1174 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1175 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1179 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1180 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1182 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1186 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1187 * @gh: the holder structure
1189 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1191 * Returns: 0, GLR_TRYFAILED, or errno on failure
1194 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1196 struct gfs2_glock
*gl
= gh
->gh_gl
;
1197 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1201 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1202 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1206 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1208 spin_lock(&gl
->gl_spin
);
1211 spin_unlock(&gl
->gl_spin
);
1213 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1214 error
= glock_wait_internal(gh
);
1215 if (error
== GLR_CANCELED
) {
1221 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1223 if (error
== GLR_TRYFAILED
&& (gh
->gh_flags
& GL_DUMP
))
1230 * gfs2_glock_poll - poll to see if an async request has been completed
1233 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1236 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1238 struct gfs2_glock
*gl
= gh
->gh_gl
;
1241 spin_lock(&gl
->gl_spin
);
1243 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1245 else if (list_empty(&gh
->gh_list
)) {
1246 if (gh
->gh_error
== GLR_CANCELED
) {
1247 spin_unlock(&gl
->gl_spin
);
1249 if (gfs2_glock_nq(gh
))
1256 spin_unlock(&gl
->gl_spin
);
1262 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1263 * @gh: the holder structure
1265 * Returns: 0, GLR_TRYFAILED, or errno on failure
1268 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1272 error
= glock_wait_internal(gh
);
1273 if (error
== GLR_CANCELED
) {
1275 gh
->gh_flags
&= ~GL_ASYNC
;
1276 error
= gfs2_glock_nq(gh
);
1283 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1284 * @gh: the glock holder
1288 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1290 struct gfs2_glock
*gl
= gh
->gh_gl
;
1291 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1293 if (gh
->gh_flags
& GL_SYNC
)
1294 set_bit(GLF_SYNC
, &gl
->gl_flags
);
1296 if (gh
->gh_flags
& GL_NOCACHE
)
1297 handle_callback(gl
, LM_ST_UNLOCKED
);
1299 gfs2_glmutex_lock(gl
);
1301 spin_lock(&gl
->gl_spin
);
1302 list_del_init(&gh
->gh_list
);
1304 if (list_empty(&gl
->gl_holders
)) {
1305 spin_unlock(&gl
->gl_spin
);
1307 if (glops
->go_unlock
)
1308 glops
->go_unlock(gh
);
1310 if (test_bit(GLF_SYNC
, &gl
->gl_flags
)) {
1312 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
);
1315 gl
->gl_stamp
= jiffies
;
1317 spin_lock(&gl
->gl_spin
);
1320 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1322 spin_unlock(&gl
->gl_spin
);
1326 * gfs2_glock_prefetch - Try to prefetch a glock
1328 * @state: the state to prefetch in
1329 * @flags: flags passed to go_xmote_th()
1333 static void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
,
1336 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1338 spin_lock(&gl
->gl_spin
);
1340 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1341 !list_empty(&gl
->gl_holders
) ||
1342 !list_empty(&gl
->gl_waiters1
) ||
1343 !list_empty(&gl
->gl_waiters2
) ||
1344 !list_empty(&gl
->gl_waiters3
) ||
1345 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1346 spin_unlock(&gl
->gl_spin
);
1350 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1351 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1352 spin_unlock(&gl
->gl_spin
);
1354 glops
->go_xmote_th(gl
, state
, flags
);
1357 static void greedy_work(void *data
)
1359 struct greedy
*gr
= data
;
1360 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1361 struct gfs2_glock
*gl
= gh
->gh_gl
;
1362 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1364 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1366 if (glops
->go_greedy
)
1367 glops
->go_greedy(gl
);
1369 spin_lock(&gl
->gl_spin
);
1371 if (list_empty(&gl
->gl_waiters2
)) {
1372 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1373 spin_unlock(&gl
->gl_spin
);
1374 gfs2_holder_uninit(gh
);
1377 gfs2_glock_hold(gl
);
1378 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1380 spin_unlock(&gl
->gl_spin
);
1386 * gfs2_glock_be_greedy -
1390 * Returns: 0 if go_greedy will be called, 1 otherwise
1393 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1396 struct gfs2_holder
*gh
;
1398 if (!time
|| gl
->gl_sbd
->sd_args
.ar_localcaching
||
1399 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1402 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1404 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1409 gfs2_holder_init(gl
, 0, 0, gh
);
1410 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1411 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1413 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1414 schedule_delayed_work(&gr
->gr_work
, time
);
1420 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1421 * @gh: the holder structure
1425 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1428 gfs2_holder_uninit(gh
);
1432 * gfs2_glock_nq_num - acquire a glock based on lock number
1433 * @sdp: the filesystem
1434 * @number: the lock number
1435 * @glops: the glock operations for the type of glock
1436 * @state: the state to acquire the glock in
1437 * @flags: modifier flags for the aquisition
1438 * @gh: the struct gfs2_holder
1443 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1444 struct gfs2_glock_operations
*glops
, unsigned int state
,
1445 int flags
, struct gfs2_holder
*gh
)
1447 struct gfs2_glock
*gl
;
1450 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1452 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1460 * glock_compare - Compare two struct gfs2_glock structures for sorting
1461 * @arg_a: the first structure
1462 * @arg_b: the second structure
1466 static int glock_compare(const void *arg_a
, const void *arg_b
)
1468 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1469 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1470 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1471 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1474 if (a
->ln_number
> b
->ln_number
)
1476 else if (a
->ln_number
< b
->ln_number
)
1479 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1480 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1482 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1483 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1491 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1492 * @num_gh: the number of structures
1493 * @ghs: an array of struct gfs2_holder structures
1495 * Returns: 0 on success (all glocks acquired),
1496 * errno on failure (no glocks acquired)
1499 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1500 struct gfs2_holder
**p
)
1505 for (x
= 0; x
< num_gh
; x
++)
1508 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1510 for (x
= 0; x
< num_gh
; x
++) {
1511 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1513 error
= gfs2_glock_nq(p
[x
]);
1516 gfs2_glock_dq(p
[x
]);
1525 * gfs2_glock_nq_m - acquire multiple glocks
1526 * @num_gh: the number of structures
1527 * @ghs: an array of struct gfs2_holder structures
1529 * Figure out how big an impact this function has. Either:
1530 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1531 * 2) Forget async stuff and just call nq_m_sync()
1532 * 3) Leave it like it is
1534 * Returns: 0 on success (all glocks acquired),
1535 * errno on failure (no glocks acquired)
1538 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1542 int borked
= 0, serious
= 0;
1549 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1550 return gfs2_glock_nq(ghs
);
1553 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1557 for (x
= 0; x
< num_gh
; x
++) {
1558 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1559 error
= gfs2_glock_nq(&ghs
[x
]);
1568 for (x
= 0; x
< num_gh
; x
++) {
1569 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1572 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1582 for (x
= 0; x
< num_gh
; x
++)
1584 gfs2_glock_dq(&ghs
[x
]);
1589 for (x
= 0; x
< num_gh
; x
++)
1590 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1592 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1601 * gfs2_glock_dq_m - release multiple glocks
1602 * @num_gh: the number of structures
1603 * @ghs: an array of struct gfs2_holder structures
1607 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1611 for (x
= 0; x
< num_gh
; x
++)
1612 gfs2_glock_dq(&ghs
[x
]);
1616 * gfs2_glock_dq_uninit_m - release multiple glocks
1617 * @num_gh: the number of structures
1618 * @ghs: an array of struct gfs2_holder structures
1622 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1626 for (x
= 0; x
< num_gh
; x
++)
1627 gfs2_glock_dq_uninit(&ghs
[x
]);
1631 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1632 * @sdp: the filesystem
1633 * @number: the lock number
1634 * @glops: the glock operations for the type of glock
1635 * @state: the state to acquire the glock in
1636 * @flags: modifier flags for the aquisition
1641 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1642 struct gfs2_glock_operations
*glops
,
1643 unsigned int state
, int flags
)
1645 struct gfs2_glock
*gl
;
1648 if (atomic_read(&sdp
->sd_reclaim_count
) <
1649 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1650 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1652 gfs2_glock_prefetch(gl
, state
, flags
);
1659 * gfs2_lvb_hold - attach a LVB from a glock
1660 * @gl: The glock in question
1664 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1668 gfs2_glmutex_lock(gl
);
1670 if (!atomic_read(&gl
->gl_lvb_count
)) {
1671 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1673 gfs2_glmutex_unlock(gl
);
1676 gfs2_glock_hold(gl
);
1678 atomic_inc(&gl
->gl_lvb_count
);
1680 gfs2_glmutex_unlock(gl
);
1686 * gfs2_lvb_unhold - detach a LVB from a glock
1687 * @gl: The glock in question
1691 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1693 gfs2_glock_hold(gl
);
1694 gfs2_glmutex_lock(gl
);
1696 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1697 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1698 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1703 gfs2_glmutex_unlock(gl
);
1708 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1710 gfs2_glmutex_lock(gl
);
1712 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1713 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1714 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1716 gfs2_glmutex_unlock(gl
);
1720 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1723 struct gfs2_glock
*gl
;
1725 gl
= gfs2_glock_find(sdp
, name
);
1729 if (gl
->gl_ops
->go_callback
)
1730 gl
->gl_ops
->go_callback(gl
, state
);
1731 handle_callback(gl
, state
);
1733 spin_lock(&gl
->gl_spin
);
1735 spin_unlock(&gl
->gl_spin
);
1741 * gfs2_glock_cb - Callback used by locking module
1742 * @fsdata: Pointer to the superblock
1743 * @type: Type of callback
1744 * @data: Type dependent data pointer
1746 * Called by the locking module when it wants to tell us something.
1747 * Either we need to drop a lock, one of our ASYNC requests completed, or
1748 * a journal from another client needs to be recovered.
1751 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1753 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1757 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1761 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1765 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1769 struct lm_async_cb
*async
= data
;
1770 struct gfs2_glock
*gl
;
1772 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1773 if (gfs2_assert_warn(sdp
, gl
))
1775 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1776 gl
->gl_req_bh(gl
, async
->lc_ret
);
1781 case LM_CB_NEED_RECOVERY
:
1782 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1783 if (sdp
->sd_recoverd_process
)
1784 wake_up_process(sdp
->sd_recoverd_process
);
1787 case LM_CB_DROPLOCKS
:
1788 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1789 gfs2_quota_scan(sdp
);
1793 gfs2_assert_warn(sdp
, 0);
1799 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1800 * iopen glock from memory
1801 * @io_gl: the iopen glock
1802 * @state: the state into which the glock should be put
1806 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1809 if (state
!= LM_ST_UNLOCKED
)
1811 /* FIXME: remove this? */
1815 * demote_ok - Check to see if it's ok to unlock a glock
1818 * Returns: 1 if it's ok
1821 static int demote_ok(struct gfs2_glock
*gl
)
1823 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1824 struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1827 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1829 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
1830 demote
= time_after_eq(jiffies
,
1832 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
1833 else if (glops
->go_demote_ok
)
1834 demote
= glops
->go_demote_ok(gl
);
1840 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1845 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1847 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1849 spin_lock(&sdp
->sd_reclaim_lock
);
1850 if (list_empty(&gl
->gl_reclaim
)) {
1851 gfs2_glock_hold(gl
);
1852 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1853 atomic_inc(&sdp
->sd_reclaim_count
);
1855 spin_unlock(&sdp
->sd_reclaim_lock
);
1857 wake_up(&sdp
->sd_reclaim_wq
);
1861 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1862 * @sdp: the filesystem
1864 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1865 * different glock and we notice that there are a lot of glocks in the
1870 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1872 struct gfs2_glock
*gl
;
1874 spin_lock(&sdp
->sd_reclaim_lock
);
1875 if (list_empty(&sdp
->sd_reclaim_list
)) {
1876 spin_unlock(&sdp
->sd_reclaim_lock
);
1879 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1880 struct gfs2_glock
, gl_reclaim
);
1881 list_del_init(&gl
->gl_reclaim
);
1882 spin_unlock(&sdp
->sd_reclaim_lock
);
1884 atomic_dec(&sdp
->sd_reclaim_count
);
1885 atomic_inc(&sdp
->sd_reclaimed
);
1887 if (gfs2_glmutex_trylock(gl
)) {
1888 if (queue_empty(gl
, &gl
->gl_holders
) &&
1889 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1891 handle_callback(gl
, LM_ST_UNLOCKED
);
1892 gfs2_glmutex_unlock(gl
);
1899 * examine_bucket - Call a function for glock in a hash bucket
1900 * @examiner: the function
1901 * @sdp: the filesystem
1902 * @bucket: the bucket
1904 * Returns: 1 if the bucket has entries
1907 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1908 struct gfs2_gl_hash_bucket
*bucket
)
1910 struct glock_plug plug
;
1911 struct list_head
*tmp
;
1912 struct gfs2_glock
*gl
;
1915 /* Add "plug" to end of bucket list, work back up list from there */
1916 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
1917 set_bit(GLF_PLUG
, &plug
.gl_flags
);
1919 write_lock(&bucket
->hb_lock
);
1920 list_add(&plug
.gl_list
, &bucket
->hb_list
);
1921 write_unlock(&bucket
->hb_lock
);
1924 write_lock(&bucket
->hb_lock
);
1927 tmp
= plug
.gl_list
.next
;
1929 if (tmp
== &bucket
->hb_list
) {
1930 list_del(&plug
.gl_list
);
1931 entries
= !list_empty(&bucket
->hb_list
);
1932 write_unlock(&bucket
->hb_lock
);
1935 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
1937 /* Move plug up list */
1938 list_move(&plug
.gl_list
, &gl
->gl_list
);
1940 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
1943 /* examiner() must glock_put() */
1944 gfs2_glock_hold(gl
);
1949 write_unlock(&bucket
->hb_lock
);
1956 * scan_glock - look at a glock and see if we can reclaim it
1957 * @gl: the glock to look at
1961 static void scan_glock(struct gfs2_glock
*gl
)
1963 if (gl
->gl_ops
== &gfs2_inode_glops
)
1966 if (gfs2_glmutex_trylock(gl
)) {
1967 if (queue_empty(gl
, &gl
->gl_holders
) &&
1968 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1971 gfs2_glmutex_unlock(gl
);
1978 gfs2_glmutex_unlock(gl
);
1979 gfs2_glock_schedule_for_reclaim(gl
);
1984 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1985 * @sdp: the filesystem
1989 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1993 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1994 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
2000 * clear_glock - look at a glock and see if we can free it from glock cache
2001 * @gl: the glock to look at
2005 static void clear_glock(struct gfs2_glock
*gl
)
2007 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
2010 spin_lock(&sdp
->sd_reclaim_lock
);
2011 if (!list_empty(&gl
->gl_reclaim
)) {
2012 list_del_init(&gl
->gl_reclaim
);
2013 atomic_dec(&sdp
->sd_reclaim_count
);
2014 spin_unlock(&sdp
->sd_reclaim_lock
);
2015 released
= gfs2_glock_put(gl
);
2016 gfs2_assert(sdp
, !released
);
2018 spin_unlock(&sdp
->sd_reclaim_lock
);
2021 if (gfs2_glmutex_trylock(gl
)) {
2022 if (queue_empty(gl
, &gl
->gl_holders
) &&
2023 gl
->gl_state
!= LM_ST_UNLOCKED
)
2024 handle_callback(gl
, LM_ST_UNLOCKED
);
2026 gfs2_glmutex_unlock(gl
);
2033 * gfs2_gl_hash_clear - Empty out the glock hash table
2034 * @sdp: the filesystem
2035 * @wait: wait until it's all gone
2037 * Called when unmounting the filesystem, or when inter-node lock manager
2038 * requests DROPLOCKS because it is running out of capacity.
2041 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2052 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2053 if (examine_bucket(clear_glock
, sdp
,
2054 &sdp
->sd_gl_hash
[x
]))
2060 if (time_after_eq(jiffies
,
2061 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2062 fs_warn(sdp
, "Unmount seems to be stalled. "
2063 "Dumping lock state...\n");
2064 gfs2_dump_lockstate(sdp
);
2068 invalidate_inodes(sdp
->sd_vfs
);
2074 * Diagnostic routines to help debug distributed deadlock
2078 * dump_holder - print information about a glock holder
2079 * @str: a string naming the type of holder
2080 * @gh: the glock holder
2082 * Returns: 0 on success, -ENOBUFS when we run out of space
2085 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2088 int error
= -ENOBUFS
;
2090 printk(KERN_INFO
" %s\n", str
);
2091 printk(KERN_INFO
" owner = %ld\n",
2092 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2093 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2094 printk(KERN_INFO
" gh_flags =");
2095 for (x
= 0; x
< 32; x
++)
2096 if (gh
->gh_flags
& (1 << x
))
2099 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2100 printk(KERN_INFO
" gh_iflags =");
2101 for (x
= 0; x
< 32; x
++)
2102 if (test_bit(x
, &gh
->gh_iflags
))
2105 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2113 * dump_inode - print information about an inode
2116 * Returns: 0 on success, -ENOBUFS when we run out of space
2119 static int dump_inode(struct gfs2_inode
*ip
)
2122 int error
= -ENOBUFS
;
2124 printk(KERN_INFO
" Inode:\n");
2125 printk(KERN_INFO
" num = %llu %llu\n",
2126 (unsigned long long)ip
->i_num
.no_formal_ino
,
2127 (unsigned long long)ip
->i_num
.no_addr
);
2128 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2129 printk(KERN_INFO
" i_flags =");
2130 for (x
= 0; x
< 32; x
++)
2131 if (test_bit(x
, &ip
->i_flags
))
2141 * dump_glock - print information about a glock
2143 * @count: where we are in the buffer
2145 * Returns: 0 on success, -ENOBUFS when we run out of space
2148 static int dump_glock(struct gfs2_glock
*gl
)
2150 struct gfs2_holder
*gh
;
2152 int error
= -ENOBUFS
;
2154 spin_lock(&gl
->gl_spin
);
2156 printk(KERN_INFO
"Glock 0x%p (%u, %llu)\n",
2158 gl
->gl_name
.ln_type
,
2159 (unsigned long long)gl
->gl_name
.ln_number
);
2160 printk(KERN_INFO
" gl_flags =");
2161 for (x
= 0; x
< 32; x
++)
2162 if (test_bit(x
, &gl
->gl_flags
))
2165 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2166 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2167 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
2168 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
2169 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2170 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2171 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2172 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2173 printk(KERN_INFO
" le = %s\n",
2174 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2175 printk(KERN_INFO
" reclaim = %s\n",
2176 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2178 printk(KERN_INFO
" aspace = 0x%p nrpages = %lu\n",
2180 gl
->gl_aspace
->i_mapping
->nrpages
);
2182 printk(KERN_INFO
" aspace = no\n");
2183 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2184 if (gl
->gl_req_gh
) {
2185 error
= dump_holder("Request", gl
->gl_req_gh
);
2189 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2190 error
= dump_holder("Holder", gh
);
2194 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2195 error
= dump_holder("Waiter1", gh
);
2199 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2200 error
= dump_holder("Waiter2", gh
);
2204 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2205 error
= dump_holder("Waiter3", gh
);
2209 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2210 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2211 list_empty(&gl
->gl_holders
)) {
2212 error
= dump_inode(gl
->gl_object
);
2217 printk(KERN_INFO
" Inode: busy\n");
2224 spin_unlock(&gl
->gl_spin
);
2230 * gfs2_dump_lockstate - print out the current lockstate
2231 * @sdp: the filesystem
2232 * @ub: the buffer to copy the information into
2234 * If @ub is NULL, dump the lockstate to the console.
2238 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2240 struct gfs2_gl_hash_bucket
*bucket
;
2241 struct gfs2_glock
*gl
;
2245 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2246 bucket
= &sdp
->sd_gl_hash
[x
];
2248 read_lock(&bucket
->hb_lock
);
2250 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2251 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2254 error
= dump_glock(gl
);
2259 read_unlock(&bucket
->hb_lock
);
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