2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License v.2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/delay.h>
16 #include <linux/sort.h>
17 #include <linux/jhash.h>
18 #include <linux/kref.h>
19 #include <linux/kallsyms.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <asm/uaccess.h>
24 #include "lm_interface.h"
36 /* Must be kept in sync with the beginning of struct gfs2_glock */
38 struct list_head gl_list
;
39 unsigned long gl_flags
;
43 struct gfs2_holder gr_gh
;
44 struct work_struct gr_work
;
47 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
49 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
50 static int dump_glock(struct gfs2_glock
*gl
);
53 * relaxed_state_ok - is a requested lock compatible with the current lock mode?
54 * @actual: the current state of the lock
55 * @requested: the lock state that was requested by the caller
56 * @flags: the modifier flags passed in by the caller
58 * Returns: 1 if the locks are compatible, 0 otherwise
61 static inline int relaxed_state_ok(unsigned int actual
, unsigned requested
,
64 if (actual
== requested
)
70 if (actual
== LM_ST_EXCLUSIVE
&& requested
== LM_ST_SHARED
)
73 if (actual
!= LM_ST_UNLOCKED
&& (flags
& LM_FLAG_ANY
))
80 * gl_hash() - Turn glock number into hash bucket number
81 * @lock: The glock number
83 * Returns: The number of the corresponding hash bucket
86 static unsigned int gl_hash(const struct lm_lockname
*name
)
90 h
= jhash(&name
->ln_number
, sizeof(uint64_t), 0);
91 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
92 h
&= GFS2_GL_HASH_MASK
;
98 * glock_free() - Perform a few checks and then release struct gfs2_glock
99 * @gl: The glock to release
101 * Also calls lock module to release its internal structure for this glock.
105 static void glock_free(struct gfs2_glock
*gl
)
107 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
108 struct inode
*aspace
= gl
->gl_aspace
;
110 gfs2_lm_put_lock(sdp
, gl
->gl_lock
);
113 gfs2_aspace_put(aspace
);
115 kmem_cache_free(gfs2_glock_cachep
, gl
);
119 * gfs2_glock_hold() - increment reference count on glock
120 * @gl: The glock to hold
124 void gfs2_glock_hold(struct gfs2_glock
*gl
)
126 kref_get(&gl
->gl_ref
);
129 /* All work is done after the return from kref_put() so we
130 can release the write_lock before the free. */
132 static void kill_glock(struct kref
*kref
)
134 struct gfs2_glock
*gl
= container_of(kref
, struct gfs2_glock
, gl_ref
);
135 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
137 gfs2_assert(sdp
, gl
->gl_state
== LM_ST_UNLOCKED
);
138 gfs2_assert(sdp
, list_empty(&gl
->gl_reclaim
));
139 gfs2_assert(sdp
, list_empty(&gl
->gl_holders
));
140 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters1
));
141 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters2
));
142 gfs2_assert(sdp
, list_empty(&gl
->gl_waiters3
));
146 * gfs2_glock_put() - Decrement reference count on glock
147 * @gl: The glock to put
151 int gfs2_glock_put(struct gfs2_glock
*gl
)
153 struct gfs2_gl_hash_bucket
*bucket
= gl
->gl_bucket
;
156 write_lock(&bucket
->hb_lock
);
157 if (kref_put(&gl
->gl_ref
, kill_glock
)) {
158 list_del_init(&gl
->gl_list
);
159 write_unlock(&bucket
->hb_lock
);
160 BUG_ON(spin_is_locked(&gl
->gl_spin
));
165 write_unlock(&bucket
->hb_lock
);
171 * queue_empty - check to see if a glock's queue is empty
173 * @head: the head of the queue to check
175 * This function protects the list in the event that a process already
176 * has a holder on the list and is adding a second holder for itself.
177 * The glmutex lock is what generally prevents processes from working
178 * on the same glock at once, but the special case of adding a second
179 * holder for yourself ("recursive" locking) doesn't involve locking
180 * glmutex, making the spin lock necessary.
182 * Returns: 1 if the queue is empty
185 static inline int queue_empty(struct gfs2_glock
*gl
, struct list_head
*head
)
188 spin_lock(&gl
->gl_spin
);
189 empty
= list_empty(head
);
190 spin_unlock(&gl
->gl_spin
);
195 * search_bucket() - Find struct gfs2_glock by lock number
196 * @bucket: the bucket to search
197 * @name: The lock name
199 * Returns: NULL, or the struct gfs2_glock with the requested number
202 static struct gfs2_glock
*search_bucket(struct gfs2_gl_hash_bucket
*bucket
,
203 const struct 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
||
304 glops
== &gfs2_rgrp_glops
) {
305 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
306 if (!gl
->gl_aspace
) {
312 error
= gfs2_lm_get_lock(sdp
, &name
, &gl
->gl_lock
);
316 write_lock(&bucket
->hb_lock
);
317 tmp
= search_bucket(bucket
, sdp
, &name
);
319 write_unlock(&bucket
->hb_lock
);
323 list_add_tail(&gl
->gl_list
, &bucket
->hb_list
);
324 write_unlock(&bucket
->hb_lock
);
333 gfs2_aspace_put(gl
->gl_aspace
);
335 kmem_cache_free(gfs2_glock_cachep
, gl
);
340 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
342 * @state: the state we're requesting
343 * @flags: the modifier flags
344 * @gh: the holder structure
348 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
349 struct gfs2_holder
*gh
)
351 INIT_LIST_HEAD(&gh
->gh_list
);
353 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
354 gh
->gh_owner
= current
;
355 gh
->gh_state
= state
;
356 gh
->gh_flags
= flags
;
359 init_completion(&gh
->gh_wait
);
361 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
362 gh
->gh_flags
|= GL_LOCAL_EXCL
;
368 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
369 * @state: the state we're requesting
370 * @flags: the modifier flags
371 * @gh: the holder structure
373 * Don't mess with the glock.
377 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
379 gh
->gh_state
= state
;
380 gh
->gh_flags
= flags
;
381 if (gh
->gh_state
== LM_ST_EXCLUSIVE
)
382 gh
->gh_flags
|= GL_LOCAL_EXCL
;
384 gh
->gh_iflags
&= 1 << HIF_ALLOCED
;
385 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
389 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
390 * @gh: the holder structure
394 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
396 gfs2_glock_put(gh
->gh_gl
);
402 * gfs2_holder_get - get a struct gfs2_holder structure
404 * @state: the state we're requesting
405 * @flags: the modifier flags
408 * Figure out how big an impact this function has. Either:
409 * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd
410 * 2) Leave it like it is
412 * Returns: the holder structure, NULL on ENOMEM
415 static struct gfs2_holder
*gfs2_holder_get(struct gfs2_glock
*gl
,
417 int flags
, gfp_t gfp_flags
)
419 struct gfs2_holder
*gh
;
421 gh
= kmalloc(sizeof(struct gfs2_holder
), gfp_flags
);
425 gfs2_holder_init(gl
, state
, flags
, gh
);
426 set_bit(HIF_ALLOCED
, &gh
->gh_iflags
);
427 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
432 * gfs2_holder_put - get rid of a struct gfs2_holder structure
433 * @gh: the holder structure
437 static void gfs2_holder_put(struct gfs2_holder
*gh
)
439 gfs2_holder_uninit(gh
);
444 * rq_mutex - process a mutex request in the queue
445 * @gh: the glock holder
447 * Returns: 1 if the queue is blocked
450 static int rq_mutex(struct gfs2_holder
*gh
)
452 struct gfs2_glock
*gl
= gh
->gh_gl
;
454 list_del_init(&gh
->gh_list
);
455 /* gh->gh_error never examined. */
456 set_bit(GLF_LOCK
, &gl
->gl_flags
);
457 complete(&gh
->gh_wait
);
463 * rq_promote - process a promote request in the queue
464 * @gh: the glock holder
466 * Acquire a new inter-node lock, or change a lock state to more restrictive.
468 * Returns: 1 if the queue is blocked
471 static int rq_promote(struct gfs2_holder
*gh
)
473 struct gfs2_glock
*gl
= gh
->gh_gl
;
474 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
475 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
477 if (!relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
478 if (list_empty(&gl
->gl_holders
)) {
480 set_bit(GLF_LOCK
, &gl
->gl_flags
);
481 spin_unlock(&gl
->gl_spin
);
483 if (atomic_read(&sdp
->sd_reclaim_count
) >
484 gfs2_tune_get(sdp
, gt_reclaim_limit
) &&
485 !(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
486 gfs2_reclaim_glock(sdp
);
487 gfs2_reclaim_glock(sdp
);
490 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
491 spin_lock(&gl
->gl_spin
);
496 if (list_empty(&gl
->gl_holders
)) {
497 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
498 set_bit(GLF_LOCK
, &gl
->gl_flags
);
500 struct gfs2_holder
*next_gh
;
501 if (gh
->gh_flags
& GL_LOCAL_EXCL
)
503 next_gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
,
505 if (next_gh
->gh_flags
& GL_LOCAL_EXCL
)
509 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
511 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
513 complete(&gh
->gh_wait
);
519 * rq_demote - process a demote request in the queue
520 * @gh: the glock holder
522 * Returns: 1 if the queue is blocked
525 static int rq_demote(struct gfs2_holder
*gh
)
527 struct gfs2_glock
*gl
= gh
->gh_gl
;
528 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
530 if (!list_empty(&gl
->gl_holders
))
533 if (gl
->gl_state
== gh
->gh_state
|| gl
->gl_state
== LM_ST_UNLOCKED
) {
534 list_del_init(&gh
->gh_list
);
536 spin_unlock(&gl
->gl_spin
);
537 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
540 complete(&gh
->gh_wait
);
541 spin_lock(&gl
->gl_spin
);
544 set_bit(GLF_LOCK
, &gl
->gl_flags
);
545 spin_unlock(&gl
->gl_spin
);
547 if (gh
->gh_state
== LM_ST_UNLOCKED
||
548 gl
->gl_state
!= LM_ST_EXCLUSIVE
)
549 glops
->go_drop_th(gl
);
551 glops
->go_xmote_th(gl
, gh
->gh_state
, gh
->gh_flags
);
553 spin_lock(&gl
->gl_spin
);
560 * rq_greedy - process a queued request to drop greedy status
561 * @gh: the glock holder
563 * Returns: 1 if the queue is blocked
566 static int rq_greedy(struct gfs2_holder
*gh
)
568 struct gfs2_glock
*gl
= gh
->gh_gl
;
570 list_del_init(&gh
->gh_list
);
571 /* gh->gh_error never examined. */
572 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
573 spin_unlock(&gl
->gl_spin
);
575 gfs2_holder_uninit(gh
);
576 kfree(container_of(gh
, struct greedy
, gr_gh
));
578 spin_lock(&gl
->gl_spin
);
584 * run_queue - process holder structures on a glock
588 static void run_queue(struct gfs2_glock
*gl
)
590 struct gfs2_holder
*gh
;
594 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
597 if (!list_empty(&gl
->gl_waiters1
)) {
598 gh
= list_entry(gl
->gl_waiters1
.next
,
599 struct gfs2_holder
, gh_list
);
601 if (test_bit(HIF_MUTEX
, &gh
->gh_iflags
))
602 blocked
= rq_mutex(gh
);
604 gfs2_assert_warn(gl
->gl_sbd
, 0);
606 } else if (!list_empty(&gl
->gl_waiters2
) &&
607 !test_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
)) {
608 gh
= list_entry(gl
->gl_waiters2
.next
,
609 struct gfs2_holder
, gh_list
);
611 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
))
612 blocked
= rq_demote(gh
);
613 else if (test_bit(HIF_GREEDY
, &gh
->gh_iflags
))
614 blocked
= rq_greedy(gh
);
616 gfs2_assert_warn(gl
->gl_sbd
, 0);
618 } else if (!list_empty(&gl
->gl_waiters3
)) {
619 gh
= list_entry(gl
->gl_waiters3
.next
,
620 struct gfs2_holder
, gh_list
);
622 if (test_bit(HIF_PROMOTE
, &gh
->gh_iflags
))
623 blocked
= rq_promote(gh
);
625 gfs2_assert_warn(gl
->gl_sbd
, 0);
636 * gfs2_glmutex_lock - acquire a local lock on a glock
639 * Gives caller exclusive access to manipulate a glock structure.
642 static void gfs2_glmutex_lock(struct gfs2_glock
*gl
)
644 struct gfs2_holder gh
;
646 gfs2_holder_init(gl
, 0, 0, &gh
);
647 set_bit(HIF_MUTEX
, &gh
.gh_iflags
);
649 spin_lock(&gl
->gl_spin
);
650 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
651 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters1
);
653 gl
->gl_owner
= current
;
654 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
655 complete(&gh
.gh_wait
);
657 spin_unlock(&gl
->gl_spin
);
659 wait_for_completion(&gh
.gh_wait
);
660 gfs2_holder_uninit(&gh
);
664 * gfs2_glmutex_trylock - try to acquire a local lock on a glock
667 * Returns: 1 if the glock is acquired
670 static int gfs2_glmutex_trylock(struct gfs2_glock
*gl
)
674 spin_lock(&gl
->gl_spin
);
675 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
678 gl
->gl_owner
= current
;
679 gl
->gl_ip
= (unsigned long)__builtin_return_address(0);
681 spin_unlock(&gl
->gl_spin
);
687 * gfs2_glmutex_unlock - release a local lock on a glock
692 static void gfs2_glmutex_unlock(struct gfs2_glock
*gl
)
694 spin_lock(&gl
->gl_spin
);
695 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
699 BUG_ON(!spin_is_locked(&gl
->gl_spin
));
700 spin_unlock(&gl
->gl_spin
);
704 * handle_callback - add a demote request to a lock's queue
706 * @state: the state the caller wants us to change to
708 * Note: This may fail sliently if we are out of memory.
711 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
)
713 struct gfs2_holder
*gh
, *new_gh
= NULL
;
716 spin_lock(&gl
->gl_spin
);
718 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
719 if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
) &&
720 gl
->gl_req_gh
!= gh
) {
721 if (gh
->gh_state
!= state
)
722 gh
->gh_state
= LM_ST_UNLOCKED
;
728 list_add_tail(&new_gh
->gh_list
, &gl
->gl_waiters2
);
731 spin_unlock(&gl
->gl_spin
);
733 new_gh
= gfs2_holder_get(gl
, state
, LM_FLAG_TRY
, GFP_KERNEL
);
736 set_bit(HIF_DEMOTE
, &new_gh
->gh_iflags
);
737 set_bit(HIF_DEALLOC
, &new_gh
->gh_iflags
);
743 spin_unlock(&gl
->gl_spin
);
746 gfs2_holder_put(new_gh
);
749 void gfs2_glock_inode_squish(struct inode
*inode
)
751 struct gfs2_holder gh
;
752 struct gfs2_glock
*gl
= GFS2_I(inode
)->i_gl
;
753 gfs2_holder_init(gl
, LM_ST_UNLOCKED
, 0, &gh
);
754 set_bit(HIF_DEMOTE
, &gh
.gh_iflags
);
755 spin_lock(&gl
->gl_spin
);
756 gfs2_assert(inode
->i_sb
->s_fs_info
, list_empty(&gl
->gl_holders
));
757 list_add_tail(&gh
.gh_list
, &gl
->gl_waiters2
);
759 spin_unlock(&gl
->gl_spin
);
760 wait_for_completion(&gh
.gh_wait
);
761 gfs2_holder_uninit(&gh
);
765 * state_change - record that the glock is now in a different state
767 * @new_state the new state
771 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
775 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
776 held2
= (new_state
!= LM_ST_UNLOCKED
);
778 if (held1
!= held2
) {
785 gl
->gl_state
= new_state
;
789 * xmote_bh - Called after the lock module is done acquiring a lock
790 * @gl: The glock in question
791 * @ret: the int returned from the lock module
795 static void xmote_bh(struct gfs2_glock
*gl
, unsigned int ret
)
797 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
798 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
799 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
800 int prev_state
= gl
->gl_state
;
803 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
804 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
805 gfs2_assert_warn(sdp
, !(ret
& LM_OUT_ASYNC
));
807 state_change(gl
, ret
& LM_OUT_ST_MASK
);
809 if (prev_state
!= LM_ST_UNLOCKED
&& !(ret
& LM_OUT_CACHEABLE
)) {
811 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
812 } else if (gl
->gl_state
== LM_ST_DEFERRED
) {
813 /* We might not want to do this here.
814 Look at moving to the inode glops. */
816 glops
->go_inval(gl
, DIO_DATA
);
819 /* Deal with each possible exit condition */
822 gl
->gl_stamp
= jiffies
;
824 else if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
825 spin_lock(&gl
->gl_spin
);
826 list_del_init(&gh
->gh_list
);
828 spin_unlock(&gl
->gl_spin
);
830 } else if (test_bit(HIF_DEMOTE
, &gh
->gh_iflags
)) {
831 spin_lock(&gl
->gl_spin
);
832 list_del_init(&gh
->gh_list
);
833 if (gl
->gl_state
== gh
->gh_state
||
834 gl
->gl_state
== LM_ST_UNLOCKED
)
837 if (gfs2_assert_warn(sdp
, gh
->gh_flags
&
838 (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) == -1)
839 fs_warn(sdp
, "ret = 0x%.8X\n", ret
);
840 gh
->gh_error
= GLR_TRYFAILED
;
842 spin_unlock(&gl
->gl_spin
);
844 if (ret
& LM_OUT_CANCELED
)
845 handle_callback(gl
, LM_ST_UNLOCKED
); /* Lame */
847 } else if (ret
& LM_OUT_CANCELED
) {
848 spin_lock(&gl
->gl_spin
);
849 list_del_init(&gh
->gh_list
);
850 gh
->gh_error
= GLR_CANCELED
;
851 spin_unlock(&gl
->gl_spin
);
853 } else if (relaxed_state_ok(gl
->gl_state
, gh
->gh_state
, gh
->gh_flags
)) {
854 spin_lock(&gl
->gl_spin
);
855 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
857 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
858 spin_unlock(&gl
->gl_spin
);
860 set_bit(HIF_FIRST
, &gh
->gh_iflags
);
864 } else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
865 spin_lock(&gl
->gl_spin
);
866 list_del_init(&gh
->gh_list
);
867 gh
->gh_error
= GLR_TRYFAILED
;
868 spin_unlock(&gl
->gl_spin
);
871 if (gfs2_assert_withdraw(sdp
, 0) == -1)
872 fs_err(sdp
, "ret = 0x%.8X\n", ret
);
875 if (glops
->go_xmote_bh
)
876 glops
->go_xmote_bh(gl
);
879 spin_lock(&gl
->gl_spin
);
880 gl
->gl_req_gh
= NULL
;
881 gl
->gl_req_bh
= NULL
;
882 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
884 spin_unlock(&gl
->gl_spin
);
890 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
893 complete(&gh
->gh_wait
);
898 * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock
899 * @gl: The glock in question
900 * @state: the requested state
901 * @flags: modifier flags to the lock call
905 void gfs2_glock_xmote_th(struct gfs2_glock
*gl
, unsigned int state
, int flags
)
907 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
908 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
909 int lck_flags
= flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
|
910 LM_FLAG_NOEXP
| LM_FLAG_ANY
|
912 unsigned int lck_ret
;
914 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
915 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
916 gfs2_assert_warn(sdp
, state
!= LM_ST_UNLOCKED
);
917 gfs2_assert_warn(sdp
, state
!= gl
->gl_state
);
919 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
922 DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
926 gl
->gl_req_bh
= xmote_bh
;
928 lck_ret
= gfs2_lm_lock(sdp
, gl
->gl_lock
, gl
->gl_state
, state
, lck_flags
);
930 if (gfs2_assert_withdraw(sdp
, !(lck_ret
& LM_OUT_ERROR
)))
933 if (lck_ret
& LM_OUT_ASYNC
)
934 gfs2_assert_warn(sdp
, lck_ret
== LM_OUT_ASYNC
);
936 xmote_bh(gl
, lck_ret
);
940 * drop_bh - Called after a lock module unlock completes
942 * @ret: the return status
944 * Doesn't wake up the process waiting on the struct gfs2_holder (if any)
945 * Doesn't drop the reference on the glock the top half took out
949 static void drop_bh(struct gfs2_glock
*gl
, unsigned int ret
)
951 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
952 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
953 struct gfs2_holder
*gh
= gl
->gl_req_gh
;
955 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
957 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
958 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
959 gfs2_assert_warn(sdp
, !ret
);
961 state_change(gl
, LM_ST_UNLOCKED
);
964 glops
->go_inval(gl
, DIO_METADATA
| DIO_DATA
);
967 spin_lock(&gl
->gl_spin
);
968 list_del_init(&gh
->gh_list
);
970 spin_unlock(&gl
->gl_spin
);
973 if (glops
->go_drop_bh
)
974 glops
->go_drop_bh(gl
);
976 spin_lock(&gl
->gl_spin
);
977 gl
->gl_req_gh
= NULL
;
978 gl
->gl_req_bh
= NULL
;
979 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
981 spin_unlock(&gl
->gl_spin
);
986 if (test_bit(HIF_DEALLOC
, &gh
->gh_iflags
))
989 complete(&gh
->gh_wait
);
994 * gfs2_glock_drop_th - call into the lock module to unlock a lock
999 void gfs2_glock_drop_th(struct gfs2_glock
*gl
)
1001 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1002 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1005 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1006 gfs2_assert_warn(sdp
, queue_empty(gl
, &gl
->gl_holders
));
1007 gfs2_assert_warn(sdp
, gl
->gl_state
!= LM_ST_UNLOCKED
);
1009 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
1011 glops
->go_sync(gl
, DIO_METADATA
| DIO_DATA
| DIO_RELEASE
);
1014 gfs2_glock_hold(gl
);
1015 gl
->gl_req_bh
= drop_bh
;
1017 ret
= gfs2_lm_unlock(sdp
, gl
->gl_lock
, gl
->gl_state
);
1019 if (gfs2_assert_withdraw(sdp
, !(ret
& LM_OUT_ERROR
)))
1025 gfs2_assert_warn(sdp
, ret
== LM_OUT_ASYNC
);
1029 * do_cancels - cancel requests for locks stuck waiting on an expire flag
1030 * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock
1032 * Don't cancel GL_NOCANCEL requests.
1035 static void do_cancels(struct gfs2_holder
*gh
)
1037 struct gfs2_glock
*gl
= gh
->gh_gl
;
1039 spin_lock(&gl
->gl_spin
);
1041 while (gl
->gl_req_gh
!= gh
&&
1042 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1043 !list_empty(&gh
->gh_list
)) {
1044 if (gl
->gl_req_bh
&&
1046 (gl
->gl_req_gh
->gh_flags
& GL_NOCANCEL
))) {
1047 spin_unlock(&gl
->gl_spin
);
1048 gfs2_lm_cancel(gl
->gl_sbd
, gl
->gl_lock
);
1050 spin_lock(&gl
->gl_spin
);
1052 spin_unlock(&gl
->gl_spin
);
1054 spin_lock(&gl
->gl_spin
);
1058 spin_unlock(&gl
->gl_spin
);
1062 * glock_wait_internal - wait on a glock acquisition
1063 * @gh: the glock holder
1065 * Returns: 0 on success
1068 static int glock_wait_internal(struct gfs2_holder
*gh
)
1070 struct gfs2_glock
*gl
= gh
->gh_gl
;
1071 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1072 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1074 if (test_bit(HIF_ABORTED
, &gh
->gh_iflags
))
1077 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
1078 spin_lock(&gl
->gl_spin
);
1079 if (gl
->gl_req_gh
!= gh
&&
1080 !test_bit(HIF_HOLDER
, &gh
->gh_iflags
) &&
1081 !list_empty(&gh
->gh_list
)) {
1082 list_del_init(&gh
->gh_list
);
1083 gh
->gh_error
= GLR_TRYFAILED
;
1085 spin_unlock(&gl
->gl_spin
);
1086 return gh
->gh_error
;
1088 spin_unlock(&gl
->gl_spin
);
1091 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1094 wait_for_completion(&gh
->gh_wait
);
1097 return gh
->gh_error
;
1099 gfs2_assert_withdraw(sdp
, test_bit(HIF_HOLDER
, &gh
->gh_iflags
));
1100 gfs2_assert_withdraw(sdp
, relaxed_state_ok(gl
->gl_state
,
1104 if (test_bit(HIF_FIRST
, &gh
->gh_iflags
)) {
1105 gfs2_assert_warn(sdp
, test_bit(GLF_LOCK
, &gl
->gl_flags
));
1107 if (glops
->go_lock
) {
1108 gh
->gh_error
= glops
->go_lock(gh
);
1110 spin_lock(&gl
->gl_spin
);
1111 list_del_init(&gh
->gh_list
);
1112 spin_unlock(&gl
->gl_spin
);
1116 spin_lock(&gl
->gl_spin
);
1117 gl
->gl_req_gh
= NULL
;
1118 gl
->gl_req_bh
= NULL
;
1119 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1121 spin_unlock(&gl
->gl_spin
);
1124 return gh
->gh_error
;
1127 static inline struct gfs2_holder
*
1128 find_holder_by_owner(struct list_head
*head
, struct task_struct
*owner
)
1130 struct gfs2_holder
*gh
;
1132 list_for_each_entry(gh
, head
, gh_list
) {
1133 if (gh
->gh_owner
== owner
)
1141 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1142 * @gh: the holder structure to add
1146 static void add_to_queue(struct gfs2_holder
*gh
)
1148 struct gfs2_glock
*gl
= gh
->gh_gl
;
1149 struct gfs2_holder
*existing
;
1151 BUG_ON(!gh
->gh_owner
);
1153 existing
= find_holder_by_owner(&gl
->gl_holders
, gh
->gh_owner
);
1155 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1156 printk(KERN_INFO
"pid : %d\n", existing
->gh_owner
->pid
);
1157 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1158 existing
->gh_gl
->gl_name
.ln_type
, existing
->gh_gl
->gl_state
);
1159 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1160 printk(KERN_INFO
"pid : %d\n", gh
->gh_owner
->pid
);
1161 printk(KERN_INFO
"lock type : %d lock state : %d\n",
1162 gl
->gl_name
.ln_type
, gl
->gl_state
);
1166 existing
= find_holder_by_owner(&gl
->gl_waiters3
, gh
->gh_owner
);
1168 print_symbol(KERN_WARNING
"original: %s\n", existing
->gh_ip
);
1169 print_symbol(KERN_WARNING
"new: %s\n", gh
->gh_ip
);
1173 if (gh
->gh_flags
& LM_FLAG_PRIORITY
)
1174 list_add(&gh
->gh_list
, &gl
->gl_waiters3
);
1176 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters3
);
1180 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1181 * @gh: the holder structure
1183 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1185 * Returns: 0, GLR_TRYFAILED, or errno on failure
1188 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1190 struct gfs2_glock
*gl
= gh
->gh_gl
;
1191 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1195 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
))) {
1196 set_bit(HIF_ABORTED
, &gh
->gh_iflags
);
1200 set_bit(HIF_PROMOTE
, &gh
->gh_iflags
);
1202 spin_lock(&gl
->gl_spin
);
1205 spin_unlock(&gl
->gl_spin
);
1207 if (!(gh
->gh_flags
& GL_ASYNC
)) {
1208 error
= glock_wait_internal(gh
);
1209 if (error
== GLR_CANCELED
) {
1215 clear_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1217 if (error
== GLR_TRYFAILED
&& (gh
->gh_flags
& GL_DUMP
))
1224 * gfs2_glock_poll - poll to see if an async request has been completed
1227 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1230 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1232 struct gfs2_glock
*gl
= gh
->gh_gl
;
1235 spin_lock(&gl
->gl_spin
);
1237 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1239 else if (list_empty(&gh
->gh_list
)) {
1240 if (gh
->gh_error
== GLR_CANCELED
) {
1241 spin_unlock(&gl
->gl_spin
);
1243 if (gfs2_glock_nq(gh
))
1250 spin_unlock(&gl
->gl_spin
);
1256 * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC
1257 * @gh: the holder structure
1259 * Returns: 0, GLR_TRYFAILED, or errno on failure
1262 int gfs2_glock_wait(struct gfs2_holder
*gh
)
1266 error
= glock_wait_internal(gh
);
1267 if (error
== GLR_CANCELED
) {
1269 gh
->gh_flags
&= ~GL_ASYNC
;
1270 error
= gfs2_glock_nq(gh
);
1277 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1278 * @gh: the glock holder
1282 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1284 struct gfs2_glock
*gl
= gh
->gh_gl
;
1285 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1287 if (gh
->gh_flags
& GL_NOCACHE
)
1288 handle_callback(gl
, LM_ST_UNLOCKED
);
1290 gfs2_glmutex_lock(gl
);
1292 spin_lock(&gl
->gl_spin
);
1293 list_del_init(&gh
->gh_list
);
1295 if (list_empty(&gl
->gl_holders
)) {
1296 spin_unlock(&gl
->gl_spin
);
1298 if (glops
->go_unlock
)
1299 glops
->go_unlock(gh
);
1301 gl
->gl_stamp
= jiffies
;
1303 spin_lock(&gl
->gl_spin
);
1306 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1308 spin_unlock(&gl
->gl_spin
);
1312 * gfs2_glock_prefetch - Try to prefetch a glock
1314 * @state: the state to prefetch in
1315 * @flags: flags passed to go_xmote_th()
1319 static void gfs2_glock_prefetch(struct gfs2_glock
*gl
, unsigned int state
,
1322 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1324 spin_lock(&gl
->gl_spin
);
1326 if (test_bit(GLF_LOCK
, &gl
->gl_flags
) ||
1327 !list_empty(&gl
->gl_holders
) ||
1328 !list_empty(&gl
->gl_waiters1
) ||
1329 !list_empty(&gl
->gl_waiters2
) ||
1330 !list_empty(&gl
->gl_waiters3
) ||
1331 relaxed_state_ok(gl
->gl_state
, state
, flags
)) {
1332 spin_unlock(&gl
->gl_spin
);
1336 set_bit(GLF_PREFETCH
, &gl
->gl_flags
);
1337 set_bit(GLF_LOCK
, &gl
->gl_flags
);
1338 spin_unlock(&gl
->gl_spin
);
1340 glops
->go_xmote_th(gl
, state
, flags
);
1343 static void greedy_work(void *data
)
1345 struct greedy
*gr
= data
;
1346 struct gfs2_holder
*gh
= &gr
->gr_gh
;
1347 struct gfs2_glock
*gl
= gh
->gh_gl
;
1348 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1350 clear_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1352 if (glops
->go_greedy
)
1353 glops
->go_greedy(gl
);
1355 spin_lock(&gl
->gl_spin
);
1357 if (list_empty(&gl
->gl_waiters2
)) {
1358 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1359 spin_unlock(&gl
->gl_spin
);
1360 gfs2_holder_uninit(gh
);
1363 gfs2_glock_hold(gl
);
1364 list_add_tail(&gh
->gh_list
, &gl
->gl_waiters2
);
1366 spin_unlock(&gl
->gl_spin
);
1372 * gfs2_glock_be_greedy -
1376 * Returns: 0 if go_greedy will be called, 1 otherwise
1379 int gfs2_glock_be_greedy(struct gfs2_glock
*gl
, unsigned int time
)
1382 struct gfs2_holder
*gh
;
1384 if (!time
|| gl
->gl_sbd
->sd_args
.ar_localcaching
||
1385 test_and_set_bit(GLF_GREEDY
, &gl
->gl_flags
))
1388 gr
= kmalloc(sizeof(struct greedy
), GFP_KERNEL
);
1390 clear_bit(GLF_GREEDY
, &gl
->gl_flags
);
1395 gfs2_holder_init(gl
, 0, 0, gh
);
1396 set_bit(HIF_GREEDY
, &gh
->gh_iflags
);
1397 INIT_WORK(&gr
->gr_work
, greedy_work
, gr
);
1399 set_bit(GLF_SKIP_WAITERS2
, &gl
->gl_flags
);
1400 schedule_delayed_work(&gr
->gr_work
, time
);
1406 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1407 * @gh: the holder structure
1411 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1414 gfs2_holder_uninit(gh
);
1418 * gfs2_glock_nq_num - acquire a glock based on lock number
1419 * @sdp: the filesystem
1420 * @number: the lock number
1421 * @glops: the glock operations for the type of glock
1422 * @state: the state to acquire the glock in
1423 * @flags: modifier flags for the aquisition
1424 * @gh: the struct gfs2_holder
1429 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1430 const struct gfs2_glock_operations
*glops
,
1431 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1433 struct gfs2_glock
*gl
;
1436 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1438 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1446 * glock_compare - Compare two struct gfs2_glock structures for sorting
1447 * @arg_a: the first structure
1448 * @arg_b: the second structure
1452 static int glock_compare(const void *arg_a
, const void *arg_b
)
1454 struct gfs2_holder
*gh_a
= *(struct gfs2_holder
**)arg_a
;
1455 struct gfs2_holder
*gh_b
= *(struct gfs2_holder
**)arg_b
;
1456 struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1457 struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1460 if (a
->ln_number
> b
->ln_number
)
1462 else if (a
->ln_number
< b
->ln_number
)
1465 if (gh_a
->gh_state
== LM_ST_SHARED
&&
1466 gh_b
->gh_state
== LM_ST_EXCLUSIVE
)
1468 else if (!(gh_a
->gh_flags
& GL_LOCAL_EXCL
) &&
1469 (gh_b
->gh_flags
& GL_LOCAL_EXCL
))
1477 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1478 * @num_gh: the number of structures
1479 * @ghs: an array of struct gfs2_holder structures
1481 * Returns: 0 on success (all glocks acquired),
1482 * errno on failure (no glocks acquired)
1485 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1486 struct gfs2_holder
**p
)
1491 for (x
= 0; x
< num_gh
; x
++)
1494 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1496 for (x
= 0; x
< num_gh
; x
++) {
1497 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1499 error
= gfs2_glock_nq(p
[x
]);
1502 gfs2_glock_dq(p
[x
]);
1511 * gfs2_glock_nq_m - acquire multiple glocks
1512 * @num_gh: the number of structures
1513 * @ghs: an array of struct gfs2_holder structures
1515 * Figure out how big an impact this function has. Either:
1516 * 1) Replace this code with code that calls gfs2_glock_prefetch()
1517 * 2) Forget async stuff and just call nq_m_sync()
1518 * 3) Leave it like it is
1520 * Returns: 0 on success (all glocks acquired),
1521 * errno on failure (no glocks acquired)
1524 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1528 int borked
= 0, serious
= 0;
1535 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1536 return gfs2_glock_nq(ghs
);
1539 e
= kcalloc(num_gh
, sizeof(struct gfs2_holder
*), GFP_KERNEL
);
1543 for (x
= 0; x
< num_gh
; x
++) {
1544 ghs
[x
].gh_flags
|= LM_FLAG_TRY
| GL_ASYNC
;
1545 error
= gfs2_glock_nq(&ghs
[x
]);
1554 for (x
= 0; x
< num_gh
; x
++) {
1555 error
= e
[x
] = glock_wait_internal(&ghs
[x
]);
1558 if (error
!= GLR_TRYFAILED
&& error
!= GLR_CANCELED
)
1568 for (x
= 0; x
< num_gh
; x
++)
1570 gfs2_glock_dq(&ghs
[x
]);
1575 for (x
= 0; x
< num_gh
; x
++)
1576 gfs2_holder_reinit(ghs
[x
].gh_state
, ghs
[x
].gh_flags
,
1578 error
= nq_m_sync(num_gh
, ghs
, (struct gfs2_holder
**)e
);
1587 * gfs2_glock_dq_m - release multiple glocks
1588 * @num_gh: the number of structures
1589 * @ghs: an array of struct gfs2_holder structures
1593 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1597 for (x
= 0; x
< num_gh
; x
++)
1598 gfs2_glock_dq(&ghs
[x
]);
1602 * gfs2_glock_dq_uninit_m - release multiple glocks
1603 * @num_gh: the number of structures
1604 * @ghs: an array of struct gfs2_holder structures
1608 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1612 for (x
= 0; x
< num_gh
; x
++)
1613 gfs2_glock_dq_uninit(&ghs
[x
]);
1617 * gfs2_glock_prefetch_num - prefetch a glock based on lock number
1618 * @sdp: the filesystem
1619 * @number: the lock number
1620 * @glops: the glock operations for the type of glock
1621 * @state: the state to acquire the glock in
1622 * @flags: modifier flags for the aquisition
1627 void gfs2_glock_prefetch_num(struct gfs2_sbd
*sdp
, uint64_t number
,
1628 const struct gfs2_glock_operations
*glops
,
1629 unsigned int state
, int flags
)
1631 struct gfs2_glock
*gl
;
1634 if (atomic_read(&sdp
->sd_reclaim_count
) <
1635 gfs2_tune_get(sdp
, gt_reclaim_limit
)) {
1636 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1638 gfs2_glock_prefetch(gl
, state
, flags
);
1645 * gfs2_lvb_hold - attach a LVB from a glock
1646 * @gl: The glock in question
1650 int gfs2_lvb_hold(struct gfs2_glock
*gl
)
1654 gfs2_glmutex_lock(gl
);
1656 if (!atomic_read(&gl
->gl_lvb_count
)) {
1657 error
= gfs2_lm_hold_lvb(gl
->gl_sbd
, gl
->gl_lock
, &gl
->gl_lvb
);
1659 gfs2_glmutex_unlock(gl
);
1662 gfs2_glock_hold(gl
);
1664 atomic_inc(&gl
->gl_lvb_count
);
1666 gfs2_glmutex_unlock(gl
);
1672 * gfs2_lvb_unhold - detach a LVB from a glock
1673 * @gl: The glock in question
1677 void gfs2_lvb_unhold(struct gfs2_glock
*gl
)
1679 gfs2_glock_hold(gl
);
1680 gfs2_glmutex_lock(gl
);
1682 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
) > 0);
1683 if (atomic_dec_and_test(&gl
->gl_lvb_count
)) {
1684 gfs2_lm_unhold_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1689 gfs2_glmutex_unlock(gl
);
1694 void gfs2_lvb_sync(struct gfs2_glock
*gl
)
1696 gfs2_glmutex_lock(gl
);
1698 gfs2_assert(gl
->gl_sbd
, atomic_read(&gl
->gl_lvb_count
));
1699 if (!gfs2_assert_warn(gl
->gl_sbd
, gfs2_glock_is_held_excl(gl
)))
1700 gfs2_lm_sync_lvb(gl
->gl_sbd
, gl
->gl_lock
, gl
->gl_lvb
);
1702 gfs2_glmutex_unlock(gl
);
1706 static void blocking_cb(struct gfs2_sbd
*sdp
, struct lm_lockname
*name
,
1709 struct gfs2_glock
*gl
;
1711 gl
= gfs2_glock_find(sdp
, name
);
1715 if (gl
->gl_ops
->go_callback
)
1716 gl
->gl_ops
->go_callback(gl
, state
);
1717 handle_callback(gl
, state
);
1719 spin_lock(&gl
->gl_spin
);
1721 spin_unlock(&gl
->gl_spin
);
1727 * gfs2_glock_cb - Callback used by locking module
1728 * @fsdata: Pointer to the superblock
1729 * @type: Type of callback
1730 * @data: Type dependent data pointer
1732 * Called by the locking module when it wants to tell us something.
1733 * Either we need to drop a lock, one of our ASYNC requests completed, or
1734 * a journal from another client needs to be recovered.
1737 void gfs2_glock_cb(lm_fsdata_t
*fsdata
, unsigned int type
, void *data
)
1739 struct gfs2_sbd
*sdp
= (struct gfs2_sbd
*)fsdata
;
1743 blocking_cb(sdp
, data
, LM_ST_UNLOCKED
);
1747 blocking_cb(sdp
, data
, LM_ST_DEFERRED
);
1751 blocking_cb(sdp
, data
, LM_ST_SHARED
);
1755 struct lm_async_cb
*async
= data
;
1756 struct gfs2_glock
*gl
;
1758 gl
= gfs2_glock_find(sdp
, &async
->lc_name
);
1759 if (gfs2_assert_warn(sdp
, gl
))
1761 if (!gfs2_assert_warn(sdp
, gl
->gl_req_bh
))
1762 gl
->gl_req_bh(gl
, async
->lc_ret
);
1767 case LM_CB_NEED_RECOVERY
:
1768 gfs2_jdesc_make_dirty(sdp
, *(unsigned int *)data
);
1769 if (sdp
->sd_recoverd_process
)
1770 wake_up_process(sdp
->sd_recoverd_process
);
1773 case LM_CB_DROPLOCKS
:
1774 gfs2_gl_hash_clear(sdp
, NO_WAIT
);
1775 gfs2_quota_scan(sdp
);
1779 gfs2_assert_warn(sdp
, 0);
1785 * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
1786 * iopen glock from memory
1787 * @io_gl: the iopen glock
1788 * @state: the state into which the glock should be put
1792 void gfs2_iopen_go_callback(struct gfs2_glock
*io_gl
, unsigned int state
)
1795 if (state
!= LM_ST_UNLOCKED
)
1797 /* FIXME: remove this? */
1801 * demote_ok - Check to see if it's ok to unlock a glock
1804 * Returns: 1 if it's ok
1807 static int demote_ok(struct gfs2_glock
*gl
)
1809 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1810 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1813 if (test_bit(GLF_STICKY
, &gl
->gl_flags
))
1815 else if (test_bit(GLF_PREFETCH
, &gl
->gl_flags
))
1816 demote
= time_after_eq(jiffies
,
1818 gfs2_tune_get(sdp
, gt_prefetch_secs
) * HZ
);
1819 else if (glops
->go_demote_ok
)
1820 demote
= glops
->go_demote_ok(gl
);
1826 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1831 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
1833 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1835 spin_lock(&sdp
->sd_reclaim_lock
);
1836 if (list_empty(&gl
->gl_reclaim
)) {
1837 gfs2_glock_hold(gl
);
1838 list_add(&gl
->gl_reclaim
, &sdp
->sd_reclaim_list
);
1839 atomic_inc(&sdp
->sd_reclaim_count
);
1841 spin_unlock(&sdp
->sd_reclaim_lock
);
1843 wake_up(&sdp
->sd_reclaim_wq
);
1847 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1848 * @sdp: the filesystem
1850 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1851 * different glock and we notice that there are a lot of glocks in the
1856 void gfs2_reclaim_glock(struct gfs2_sbd
*sdp
)
1858 struct gfs2_glock
*gl
;
1860 spin_lock(&sdp
->sd_reclaim_lock
);
1861 if (list_empty(&sdp
->sd_reclaim_list
)) {
1862 spin_unlock(&sdp
->sd_reclaim_lock
);
1865 gl
= list_entry(sdp
->sd_reclaim_list
.next
,
1866 struct gfs2_glock
, gl_reclaim
);
1867 list_del_init(&gl
->gl_reclaim
);
1868 spin_unlock(&sdp
->sd_reclaim_lock
);
1870 atomic_dec(&sdp
->sd_reclaim_count
);
1871 atomic_inc(&sdp
->sd_reclaimed
);
1873 if (gfs2_glmutex_trylock(gl
)) {
1874 if (queue_empty(gl
, &gl
->gl_holders
) &&
1875 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1877 handle_callback(gl
, LM_ST_UNLOCKED
);
1878 gfs2_glmutex_unlock(gl
);
1885 * examine_bucket - Call a function for glock in a hash bucket
1886 * @examiner: the function
1887 * @sdp: the filesystem
1888 * @bucket: the bucket
1890 * Returns: 1 if the bucket has entries
1893 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1894 struct gfs2_gl_hash_bucket
*bucket
)
1896 struct glock_plug plug
;
1897 struct list_head
*tmp
;
1898 struct gfs2_glock
*gl
;
1901 /* Add "plug" to end of bucket list, work back up list from there */
1902 memset(&plug
.gl_flags
, 0, sizeof(unsigned long));
1903 set_bit(GLF_PLUG
, &plug
.gl_flags
);
1905 write_lock(&bucket
->hb_lock
);
1906 list_add(&plug
.gl_list
, &bucket
->hb_list
);
1907 write_unlock(&bucket
->hb_lock
);
1910 write_lock(&bucket
->hb_lock
);
1913 tmp
= plug
.gl_list
.next
;
1915 if (tmp
== &bucket
->hb_list
) {
1916 list_del(&plug
.gl_list
);
1917 entries
= !list_empty(&bucket
->hb_list
);
1918 write_unlock(&bucket
->hb_lock
);
1921 gl
= list_entry(tmp
, struct gfs2_glock
, gl_list
);
1923 /* Move plug up list */
1924 list_move(&plug
.gl_list
, &gl
->gl_list
);
1926 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
1929 /* examiner() must glock_put() */
1930 gfs2_glock_hold(gl
);
1935 write_unlock(&bucket
->hb_lock
);
1942 * scan_glock - look at a glock and see if we can reclaim it
1943 * @gl: the glock to look at
1947 static void scan_glock(struct gfs2_glock
*gl
)
1949 if (gl
->gl_ops
== &gfs2_inode_glops
)
1952 if (gfs2_glmutex_trylock(gl
)) {
1953 if (queue_empty(gl
, &gl
->gl_holders
) &&
1954 gl
->gl_state
!= LM_ST_UNLOCKED
&&
1957 gfs2_glmutex_unlock(gl
);
1964 gfs2_glmutex_unlock(gl
);
1965 gfs2_glock_schedule_for_reclaim(gl
);
1970 * gfs2_scand_internal - Look for glocks and inodes to toss from memory
1971 * @sdp: the filesystem
1975 void gfs2_scand_internal(struct gfs2_sbd
*sdp
)
1979 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1980 examine_bucket(scan_glock
, sdp
, &sdp
->sd_gl_hash
[x
]);
1986 * clear_glock - look at a glock and see if we can free it from glock cache
1987 * @gl: the glock to look at
1991 static void clear_glock(struct gfs2_glock
*gl
)
1993 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1996 spin_lock(&sdp
->sd_reclaim_lock
);
1997 if (!list_empty(&gl
->gl_reclaim
)) {
1998 list_del_init(&gl
->gl_reclaim
);
1999 atomic_dec(&sdp
->sd_reclaim_count
);
2000 spin_unlock(&sdp
->sd_reclaim_lock
);
2001 released
= gfs2_glock_put(gl
);
2002 gfs2_assert(sdp
, !released
);
2004 spin_unlock(&sdp
->sd_reclaim_lock
);
2007 if (gfs2_glmutex_trylock(gl
)) {
2008 if (queue_empty(gl
, &gl
->gl_holders
) &&
2009 gl
->gl_state
!= LM_ST_UNLOCKED
)
2010 handle_callback(gl
, LM_ST_UNLOCKED
);
2012 gfs2_glmutex_unlock(gl
);
2019 * gfs2_gl_hash_clear - Empty out the glock hash table
2020 * @sdp: the filesystem
2021 * @wait: wait until it's all gone
2023 * Called when unmounting the filesystem, or when inter-node lock manager
2024 * requests DROPLOCKS because it is running out of capacity.
2027 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
, int wait
)
2038 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
2039 if (examine_bucket(clear_glock
, sdp
,
2040 &sdp
->sd_gl_hash
[x
]))
2046 if (time_after_eq(jiffies
,
2047 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
2048 fs_warn(sdp
, "Unmount seems to be stalled. "
2049 "Dumping lock state...\n");
2050 gfs2_dump_lockstate(sdp
);
2054 invalidate_inodes(sdp
->sd_vfs
);
2060 * Diagnostic routines to help debug distributed deadlock
2064 * dump_holder - print information about a glock holder
2065 * @str: a string naming the type of holder
2066 * @gh: the glock holder
2068 * Returns: 0 on success, -ENOBUFS when we run out of space
2071 static int dump_holder(char *str
, struct gfs2_holder
*gh
)
2074 int error
= -ENOBUFS
;
2076 printk(KERN_INFO
" %s\n", str
);
2077 printk(KERN_INFO
" owner = %ld\n",
2078 (gh
->gh_owner
) ? (long)gh
->gh_owner
->pid
: -1);
2079 printk(KERN_INFO
" gh_state = %u\n", gh
->gh_state
);
2080 printk(KERN_INFO
" gh_flags =");
2081 for (x
= 0; x
< 32; x
++)
2082 if (gh
->gh_flags
& (1 << x
))
2085 printk(KERN_INFO
" error = %d\n", gh
->gh_error
);
2086 printk(KERN_INFO
" gh_iflags =");
2087 for (x
= 0; x
< 32; x
++)
2088 if (test_bit(x
, &gh
->gh_iflags
))
2091 print_symbol(KERN_INFO
" initialized at: %s\n", gh
->gh_ip
);
2099 * dump_inode - print information about an inode
2102 * Returns: 0 on success, -ENOBUFS when we run out of space
2105 static int dump_inode(struct gfs2_inode
*ip
)
2108 int error
= -ENOBUFS
;
2110 printk(KERN_INFO
" Inode:\n");
2111 printk(KERN_INFO
" num = %llu %llu\n",
2112 (unsigned long long)ip
->i_num
.no_formal_ino
,
2113 (unsigned long long)ip
->i_num
.no_addr
);
2114 printk(KERN_INFO
" type = %u\n", IF2DT(ip
->i_di
.di_mode
));
2115 printk(KERN_INFO
" i_flags =");
2116 for (x
= 0; x
< 32; x
++)
2117 if (test_bit(x
, &ip
->i_flags
))
2127 * dump_glock - print information about a glock
2129 * @count: where we are in the buffer
2131 * Returns: 0 on success, -ENOBUFS when we run out of space
2134 static int dump_glock(struct gfs2_glock
*gl
)
2136 struct gfs2_holder
*gh
;
2138 int error
= -ENOBUFS
;
2140 spin_lock(&gl
->gl_spin
);
2142 printk(KERN_INFO
"Glock 0x%p (%u, %llu)\n",
2144 gl
->gl_name
.ln_type
,
2145 (unsigned long long)gl
->gl_name
.ln_number
);
2146 printk(KERN_INFO
" gl_flags =");
2147 for (x
= 0; x
< 32; x
++)
2148 if (test_bit(x
, &gl
->gl_flags
))
2151 printk(KERN_INFO
" gl_ref = %d\n", atomic_read(&gl
->gl_ref
.refcount
));
2152 printk(KERN_INFO
" gl_state = %u\n", gl
->gl_state
);
2153 printk(KERN_INFO
" gl_owner = %s\n", gl
->gl_owner
->comm
);
2154 print_symbol(KERN_INFO
" gl_ip = %s\n", gl
->gl_ip
);
2155 printk(KERN_INFO
" req_gh = %s\n", (gl
->gl_req_gh
) ? "yes" : "no");
2156 printk(KERN_INFO
" req_bh = %s\n", (gl
->gl_req_bh
) ? "yes" : "no");
2157 printk(KERN_INFO
" lvb_count = %d\n", atomic_read(&gl
->gl_lvb_count
));
2158 printk(KERN_INFO
" object = %s\n", (gl
->gl_object
) ? "yes" : "no");
2159 printk(KERN_INFO
" le = %s\n",
2160 (list_empty(&gl
->gl_le
.le_list
)) ? "no" : "yes");
2161 printk(KERN_INFO
" reclaim = %s\n",
2162 (list_empty(&gl
->gl_reclaim
)) ? "no" : "yes");
2164 printk(KERN_INFO
" aspace = 0x%p nrpages = %lu\n",
2166 gl
->gl_aspace
->i_mapping
->nrpages
);
2168 printk(KERN_INFO
" aspace = no\n");
2169 printk(KERN_INFO
" ail = %d\n", atomic_read(&gl
->gl_ail_count
));
2170 if (gl
->gl_req_gh
) {
2171 error
= dump_holder("Request", gl
->gl_req_gh
);
2175 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
2176 error
= dump_holder("Holder", gh
);
2180 list_for_each_entry(gh
, &gl
->gl_waiters1
, gh_list
) {
2181 error
= dump_holder("Waiter1", gh
);
2185 list_for_each_entry(gh
, &gl
->gl_waiters2
, gh_list
) {
2186 error
= dump_holder("Waiter2", gh
);
2190 list_for_each_entry(gh
, &gl
->gl_waiters3
, gh_list
) {
2191 error
= dump_holder("Waiter3", gh
);
2195 if (gl
->gl_ops
== &gfs2_inode_glops
&& gl
->gl_object
) {
2196 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
) &&
2197 list_empty(&gl
->gl_holders
)) {
2198 error
= dump_inode(gl
->gl_object
);
2203 printk(KERN_INFO
" Inode: busy\n");
2210 spin_unlock(&gl
->gl_spin
);
2216 * gfs2_dump_lockstate - print out the current lockstate
2217 * @sdp: the filesystem
2218 * @ub: the buffer to copy the information into
2220 * If @ub is NULL, dump the lockstate to the console.
2224 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
2226 struct gfs2_gl_hash_bucket
*bucket
;
2227 struct gfs2_glock
*gl
;
2231 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
2232 bucket
= &sdp
->sd_gl_hash
[x
];
2234 read_lock(&bucket
->hb_lock
);
2236 list_for_each_entry(gl
, &bucket
->hb_list
, gl_list
) {
2237 if (test_bit(GLF_PLUG
, &gl
->gl_flags
))
2240 error
= dump_glock(gl
);
2245 read_unlock(&bucket
->hb_lock
);
This page took 0.17598 seconds and 6 git commands to generate.