2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/buffer_head.h>
14 #include <linux/delay.h>
15 #include <linux/sort.h>
16 #include <linux/jhash.h>
17 #include <linux/kallsyms.h>
18 #include <linux/gfs2_ondisk.h>
19 #include <linux/list.h>
20 #include <linux/wait.h>
21 #include <linux/module.h>
22 #include <asm/uaccess.h>
23 #include <linux/seq_file.h>
24 #include <linux/debugfs.h>
25 #include <linux/kthread.h>
26 #include <linux/freezer.h>
27 #include <linux/workqueue.h>
28 #include <linux/jiffies.h>
29 #include <linux/rcupdate.h>
30 #include <linux/rculist_bl.h>
31 #include <linux/bit_spinlock.h>
44 #define CREATE_TRACE_POINTS
45 #include "trace_gfs2.h"
47 struct gfs2_glock_iter
{
48 int hash
; /* hash bucket index */
49 struct gfs2_sbd
*sdp
; /* incore superblock */
50 struct gfs2_glock
*gl
; /* current glock struct */
51 char string
[512]; /* scratch space */
54 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
56 static int __dump_glock(struct seq_file
*seq
, const struct gfs2_glock
*gl
);
57 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
58 static void do_xmote(struct gfs2_glock
*gl
, struct gfs2_holder
*gh
, unsigned int target
);
60 static struct dentry
*gfs2_root
;
61 static struct workqueue_struct
*glock_workqueue
;
62 struct workqueue_struct
*gfs2_delete_workqueue
;
63 static LIST_HEAD(lru_list
);
64 static atomic_t lru_count
= ATOMIC_INIT(0);
65 static DEFINE_SPINLOCK(lru_lock
);
67 #define GFS2_GL_HASH_SHIFT 15
68 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
69 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
71 static struct hlist_bl_head gl_hash_table
[GFS2_GL_HASH_SIZE
];
72 static struct dentry
*gfs2_root
;
75 * gl_hash() - Turn glock number into hash bucket number
76 * @lock: The glock number
78 * Returns: The number of the corresponding hash bucket
81 static unsigned int gl_hash(const struct gfs2_sbd
*sdp
,
82 const struct lm_lockname
*name
)
86 h
= jhash(&name
->ln_number
, sizeof(u64
), 0);
87 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
88 h
= jhash(&sdp
, sizeof(struct gfs2_sbd
*), h
);
89 h
&= GFS2_GL_HASH_MASK
;
94 static inline void spin_lock_bucket(unsigned int hash
)
96 hlist_bl_lock(&gl_hash_table
[hash
]);
99 static inline void spin_unlock_bucket(unsigned int hash
)
101 hlist_bl_unlock(&gl_hash_table
[hash
]);
104 static void gfs2_glock_dealloc(struct rcu_head
*rcu
)
106 struct gfs2_glock
*gl
= container_of(rcu
, struct gfs2_glock
, gl_rcu
);
108 if (gl
->gl_ops
->go_flags
& GLOF_ASPACE
)
109 kmem_cache_free(gfs2_glock_aspace_cachep
, gl
);
111 kmem_cache_free(gfs2_glock_cachep
, gl
);
114 void gfs2_glock_free(struct gfs2_glock
*gl
)
116 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
118 call_rcu(&gl
->gl_rcu
, gfs2_glock_dealloc
);
119 if (atomic_dec_and_test(&sdp
->sd_glock_disposal
))
120 wake_up(&sdp
->sd_glock_wait
);
124 * gfs2_glock_hold() - increment reference count on glock
125 * @gl: The glock to hold
129 void gfs2_glock_hold(struct gfs2_glock
*gl
)
131 GLOCK_BUG_ON(gl
, atomic_read(&gl
->gl_ref
) == 0);
132 atomic_inc(&gl
->gl_ref
);
136 * demote_ok - Check to see if it's ok to unlock a glock
139 * Returns: 1 if it's ok
142 static int demote_ok(const struct gfs2_glock
*gl
)
144 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
146 if (gl
->gl_state
== LM_ST_UNLOCKED
)
148 if (!list_empty(&gl
->gl_holders
))
150 if (glops
->go_demote_ok
)
151 return glops
->go_demote_ok(gl
);
156 void gfs2_glock_add_to_lru(struct gfs2_glock
*gl
)
158 spin_lock(&lru_lock
);
160 if (!list_empty(&gl
->gl_lru
))
161 list_del_init(&gl
->gl_lru
);
163 atomic_inc(&lru_count
);
165 list_add_tail(&gl
->gl_lru
, &lru_list
);
166 set_bit(GLF_LRU
, &gl
->gl_flags
);
167 spin_unlock(&lru_lock
);
170 static void gfs2_glock_remove_from_lru(struct gfs2_glock
*gl
)
172 spin_lock(&lru_lock
);
173 if (!list_empty(&gl
->gl_lru
)) {
174 list_del_init(&gl
->gl_lru
);
175 atomic_dec(&lru_count
);
176 clear_bit(GLF_LRU
, &gl
->gl_flags
);
178 spin_unlock(&lru_lock
);
182 * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
185 * If the glock is demotable, then we add it (or move it) to the end
186 * of the glock LRU list.
189 static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
192 gfs2_glock_add_to_lru(gl
);
196 * gfs2_glock_put_nolock() - Decrement reference count on glock
197 * @gl: The glock to put
199 * This function should only be used if the caller has its own reference
200 * to the glock, in addition to the one it is dropping.
203 void gfs2_glock_put_nolock(struct gfs2_glock
*gl
)
205 if (atomic_dec_and_test(&gl
->gl_ref
))
210 * gfs2_glock_put() - Decrement reference count on glock
211 * @gl: The glock to put
215 void gfs2_glock_put(struct gfs2_glock
*gl
)
217 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
218 struct address_space
*mapping
= gfs2_glock2aspace(gl
);
220 if (atomic_dec_and_test(&gl
->gl_ref
)) {
221 spin_lock_bucket(gl
->gl_hash
);
222 hlist_bl_del_rcu(&gl
->gl_list
);
223 spin_unlock_bucket(gl
->gl_hash
);
224 gfs2_glock_remove_from_lru(gl
);
225 GLOCK_BUG_ON(gl
, !list_empty(&gl
->gl_holders
));
226 GLOCK_BUG_ON(gl
, mapping
&& mapping
->nrpages
);
227 trace_gfs2_glock_put(gl
);
228 sdp
->sd_lockstruct
.ls_ops
->lm_put_lock(gl
);
233 * search_bucket() - Find struct gfs2_glock by lock number
234 * @bucket: the bucket to search
235 * @name: The lock name
237 * Returns: NULL, or the struct gfs2_glock with the requested number
240 static struct gfs2_glock
*search_bucket(unsigned int hash
,
241 const struct gfs2_sbd
*sdp
,
242 const struct lm_lockname
*name
)
244 struct gfs2_glock
*gl
;
245 struct hlist_bl_node
*h
;
247 hlist_bl_for_each_entry_rcu(gl
, h
, &gl_hash_table
[hash
], gl_list
) {
248 if (!lm_name_equal(&gl
->gl_name
, name
))
250 if (gl
->gl_sbd
!= sdp
)
252 if (atomic_inc_not_zero(&gl
->gl_ref
))
260 * may_grant - check if its ok to grant a new lock
262 * @gh: The lock request which we wish to grant
264 * Returns: true if its ok to grant the lock
267 static inline int may_grant(const struct gfs2_glock
*gl
, const struct gfs2_holder
*gh
)
269 const struct gfs2_holder
*gh_head
= list_entry(gl
->gl_holders
.next
, const struct gfs2_holder
, gh_list
);
270 if ((gh
->gh_state
== LM_ST_EXCLUSIVE
||
271 gh_head
->gh_state
== LM_ST_EXCLUSIVE
) && gh
!= gh_head
)
273 if (gl
->gl_state
== gh
->gh_state
)
275 if (gh
->gh_flags
& GL_EXACT
)
277 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
278 if (gh
->gh_state
== LM_ST_SHARED
&& gh_head
->gh_state
== LM_ST_SHARED
)
280 if (gh
->gh_state
== LM_ST_DEFERRED
&& gh_head
->gh_state
== LM_ST_DEFERRED
)
283 if (gl
->gl_state
!= LM_ST_UNLOCKED
&& (gh
->gh_flags
& LM_FLAG_ANY
))
288 static void gfs2_holder_wake(struct gfs2_holder
*gh
)
290 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
291 smp_mb__after_clear_bit();
292 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
296 * do_error - Something unexpected has happened during a lock request
300 static inline void do_error(struct gfs2_glock
*gl
, const int ret
)
302 struct gfs2_holder
*gh
, *tmp
;
304 list_for_each_entry_safe(gh
, tmp
, &gl
->gl_holders
, gh_list
) {
305 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
307 if (ret
& LM_OUT_ERROR
)
309 else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))
310 gh
->gh_error
= GLR_TRYFAILED
;
313 list_del_init(&gh
->gh_list
);
314 trace_gfs2_glock_queue(gh
, 0);
315 gfs2_holder_wake(gh
);
320 * do_promote - promote as many requests as possible on the current queue
323 * Returns: 1 if there is a blocked holder at the head of the list, or 2
324 * if a type specific operation is underway.
327 static int do_promote(struct gfs2_glock
*gl
)
328 __releases(&gl
->gl_spin
)
329 __acquires(&gl
->gl_spin
)
331 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
332 struct gfs2_holder
*gh
, *tmp
;
336 list_for_each_entry_safe(gh
, tmp
, &gl
->gl_holders
, gh_list
) {
337 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
339 if (may_grant(gl
, gh
)) {
340 if (gh
->gh_list
.prev
== &gl
->gl_holders
&&
342 spin_unlock(&gl
->gl_spin
);
343 /* FIXME: eliminate this eventually */
344 ret
= glops
->go_lock(gh
);
345 spin_lock(&gl
->gl_spin
);
350 list_del_init(&gh
->gh_list
);
351 trace_gfs2_glock_queue(gh
, 0);
352 gfs2_holder_wake(gh
);
355 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
356 trace_gfs2_promote(gh
, 1);
357 gfs2_holder_wake(gh
);
360 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
361 trace_gfs2_promote(gh
, 0);
362 gfs2_holder_wake(gh
);
365 if (gh
->gh_list
.prev
== &gl
->gl_holders
)
374 * find_first_waiter - find the first gh that's waiting for the glock
378 static inline struct gfs2_holder
*find_first_waiter(const struct gfs2_glock
*gl
)
380 struct gfs2_holder
*gh
;
382 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
383 if (!test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
390 * state_change - record that the glock is now in a different state
392 * @new_state the new state
396 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
400 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
401 held2
= (new_state
!= LM_ST_UNLOCKED
);
403 if (held1
!= held2
) {
407 gfs2_glock_put_nolock(gl
);
409 if (held1
&& held2
&& list_empty(&gl
->gl_holders
))
410 clear_bit(GLF_QUEUED
, &gl
->gl_flags
);
412 gl
->gl_state
= new_state
;
413 gl
->gl_tchange
= jiffies
;
416 static void gfs2_demote_wake(struct gfs2_glock
*gl
)
418 gl
->gl_demote_state
= LM_ST_EXCLUSIVE
;
419 clear_bit(GLF_DEMOTE
, &gl
->gl_flags
);
420 smp_mb__after_clear_bit();
421 wake_up_bit(&gl
->gl_flags
, GLF_DEMOTE
);
425 * finish_xmote - The DLM has replied to one of our lock requests
427 * @ret: The status from the DLM
431 static void finish_xmote(struct gfs2_glock
*gl
, unsigned int ret
)
433 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
434 struct gfs2_holder
*gh
;
435 unsigned state
= ret
& LM_OUT_ST_MASK
;
438 spin_lock(&gl
->gl_spin
);
439 trace_gfs2_glock_state_change(gl
, state
);
440 state_change(gl
, state
);
441 gh
= find_first_waiter(gl
);
443 /* Demote to UN request arrived during demote to SH or DF */
444 if (test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
) &&
445 state
!= LM_ST_UNLOCKED
&& gl
->gl_demote_state
== LM_ST_UNLOCKED
)
446 gl
->gl_target
= LM_ST_UNLOCKED
;
448 /* Check for state != intended state */
449 if (unlikely(state
!= gl
->gl_target
)) {
450 if (gh
&& !test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
)) {
451 /* move to back of queue and try next entry */
452 if (ret
& LM_OUT_CANCELED
) {
453 if ((gh
->gh_flags
& LM_FLAG_PRIORITY
) == 0)
454 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
455 gh
= find_first_waiter(gl
);
456 gl
->gl_target
= gh
->gh_state
;
459 /* Some error or failed "try lock" - report it */
460 if ((ret
& LM_OUT_ERROR
) ||
461 (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))) {
462 gl
->gl_target
= gl
->gl_state
;
468 /* Unlocked due to conversion deadlock, try again */
471 do_xmote(gl
, gh
, gl
->gl_target
);
473 /* Conversion fails, unlock and try again */
476 do_xmote(gl
, gh
, LM_ST_UNLOCKED
);
478 default: /* Everything else */
479 printk(KERN_ERR
"GFS2: wanted %u got %u\n", gl
->gl_target
, state
);
482 spin_unlock(&gl
->gl_spin
);
486 /* Fast path - we got what we asked for */
487 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
))
488 gfs2_demote_wake(gl
);
489 if (state
!= LM_ST_UNLOCKED
) {
490 if (glops
->go_xmote_bh
) {
491 spin_unlock(&gl
->gl_spin
);
492 rv
= glops
->go_xmote_bh(gl
, gh
);
493 spin_lock(&gl
->gl_spin
);
504 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
506 spin_unlock(&gl
->gl_spin
);
510 * do_xmote - Calls the DLM to change the state of a lock
511 * @gl: The lock state
512 * @gh: The holder (only for promotes)
513 * @target: The target lock state
517 static void do_xmote(struct gfs2_glock
*gl
, struct gfs2_holder
*gh
, unsigned int target
)
518 __releases(&gl
->gl_spin
)
519 __acquires(&gl
->gl_spin
)
521 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
522 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
523 unsigned int lck_flags
= gh
? gh
->gh_flags
: 0;
526 lck_flags
&= (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
| LM_FLAG_NOEXP
|
528 GLOCK_BUG_ON(gl
, gl
->gl_state
== target
);
529 GLOCK_BUG_ON(gl
, gl
->gl_state
== gl
->gl_target
);
530 if ((target
== LM_ST_UNLOCKED
|| target
== LM_ST_DEFERRED
) &&
532 set_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
);
533 do_error(gl
, 0); /* Fail queued try locks */
536 spin_unlock(&gl
->gl_spin
);
537 if (glops
->go_xmote_th
)
538 glops
->go_xmote_th(gl
);
539 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
))
540 glops
->go_inval(gl
, target
== LM_ST_DEFERRED
? 0 : DIO_METADATA
);
541 clear_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
);
544 if (sdp
->sd_lockstruct
.ls_ops
->lm_lock
) {
546 ret
= sdp
->sd_lockstruct
.ls_ops
->lm_lock(gl
, target
, lck_flags
);
547 GLOCK_BUG_ON(gl
, ret
);
548 } else { /* lock_nolock */
549 finish_xmote(gl
, target
);
550 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
554 spin_lock(&gl
->gl_spin
);
558 * find_first_holder - find the first "holder" gh
562 static inline struct gfs2_holder
*find_first_holder(const struct gfs2_glock
*gl
)
564 struct gfs2_holder
*gh
;
566 if (!list_empty(&gl
->gl_holders
)) {
567 gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
, gh_list
);
568 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
575 * run_queue - do all outstanding tasks related to a glock
576 * @gl: The glock in question
577 * @nonblock: True if we must not block in run_queue
581 static void run_queue(struct gfs2_glock
*gl
, const int nonblock
)
582 __releases(&gl
->gl_spin
)
583 __acquires(&gl
->gl_spin
)
585 struct gfs2_holder
*gh
= NULL
;
588 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
591 GLOCK_BUG_ON(gl
, test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
));
593 if (test_bit(GLF_DEMOTE
, &gl
->gl_flags
) &&
594 gl
->gl_demote_state
!= gl
->gl_state
) {
595 if (find_first_holder(gl
))
599 set_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
);
600 GLOCK_BUG_ON(gl
, gl
->gl_demote_state
== LM_ST_EXCLUSIVE
);
601 gl
->gl_target
= gl
->gl_demote_state
;
603 if (test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
604 gfs2_demote_wake(gl
);
605 ret
= do_promote(gl
);
610 gh
= find_first_waiter(gl
);
611 gl
->gl_target
= gh
->gh_state
;
612 if (!(gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)))
613 do_error(gl
, 0); /* Fail queued try locks */
615 do_xmote(gl
, gh
, gl
->gl_target
);
620 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
621 smp_mb__after_clear_bit();
623 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
624 gfs2_glock_put_nolock(gl
);
628 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
629 smp_mb__after_clear_bit();
633 static void delete_work_func(struct work_struct
*work
)
635 struct gfs2_glock
*gl
= container_of(work
, struct gfs2_glock
, gl_delete
);
636 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
637 struct gfs2_inode
*ip
;
639 u64 no_addr
= gl
->gl_name
.ln_number
;
642 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
645 inode
= gfs2_ilookup(sdp
->sd_vfs
, no_addr
, 1);
647 inode
= gfs2_lookup_by_inum(sdp
, no_addr
, NULL
, GFS2_BLKST_UNLINKED
);
648 if (inode
&& !IS_ERR(inode
)) {
649 d_prune_aliases(inode
);
655 static void glock_work_func(struct work_struct
*work
)
657 unsigned long delay
= 0;
658 struct gfs2_glock
*gl
= container_of(work
, struct gfs2_glock
, gl_work
.work
);
661 if (test_and_clear_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
)) {
662 finish_xmote(gl
, gl
->gl_reply
);
665 spin_lock(&gl
->gl_spin
);
666 if (test_and_clear_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
667 gl
->gl_state
!= LM_ST_UNLOCKED
&&
668 gl
->gl_demote_state
!= LM_ST_EXCLUSIVE
) {
669 unsigned long holdtime
, now
= jiffies
;
670 holdtime
= gl
->gl_tchange
+ gl
->gl_ops
->go_min_hold_time
;
671 if (time_before(now
, holdtime
))
672 delay
= holdtime
- now
;
673 set_bit(delay
? GLF_PENDING_DEMOTE
: GLF_DEMOTE
, &gl
->gl_flags
);
676 spin_unlock(&gl
->gl_spin
);
678 queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
685 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
686 * @sdp: The GFS2 superblock
687 * @number: the lock number
688 * @glops: The glock_operations to use
689 * @create: If 0, don't create the glock if it doesn't exist
690 * @glp: the glock is returned here
692 * This does not lock a glock, just finds/creates structures for one.
697 int gfs2_glock_get(struct gfs2_sbd
*sdp
, u64 number
,
698 const struct gfs2_glock_operations
*glops
, int create
,
699 struct gfs2_glock
**glp
)
701 struct super_block
*s
= sdp
->sd_vfs
;
702 struct lm_lockname name
= { .ln_number
= number
, .ln_type
= glops
->go_type
};
703 struct gfs2_glock
*gl
, *tmp
;
704 unsigned int hash
= gl_hash(sdp
, &name
);
705 struct address_space
*mapping
;
706 struct kmem_cache
*cachep
;
709 gl
= search_bucket(hash
, sdp
, &name
);
718 if (glops
->go_flags
& GLOF_ASPACE
)
719 cachep
= gfs2_glock_aspace_cachep
;
721 cachep
= gfs2_glock_cachep
;
722 gl
= kmem_cache_alloc(cachep
, GFP_KERNEL
);
726 atomic_inc(&sdp
->sd_glock_disposal
);
729 atomic_set(&gl
->gl_ref
, 1);
730 gl
->gl_state
= LM_ST_UNLOCKED
;
731 gl
->gl_target
= LM_ST_UNLOCKED
;
732 gl
->gl_demote_state
= LM_ST_EXCLUSIVE
;
735 snprintf(gl
->gl_strname
, GDLM_STRNAME_BYTES
, "%8x%16llx", name
.ln_type
, (unsigned long long)number
);
736 memset(&gl
->gl_lksb
, 0, sizeof(struct dlm_lksb
));
737 gl
->gl_lksb
.sb_lvbptr
= gl
->gl_lvb
;
738 gl
->gl_tchange
= jiffies
;
739 gl
->gl_object
= NULL
;
741 INIT_DELAYED_WORK(&gl
->gl_work
, glock_work_func
);
742 INIT_WORK(&gl
->gl_delete
, delete_work_func
);
744 mapping
= gfs2_glock2aspace(gl
);
746 mapping
->a_ops
= &gfs2_meta_aops
;
747 mapping
->host
= s
->s_bdev
->bd_inode
;
749 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
750 mapping
->assoc_mapping
= NULL
;
751 mapping
->backing_dev_info
= s
->s_bdi
;
752 mapping
->writeback_index
= 0;
755 spin_lock_bucket(hash
);
756 tmp
= search_bucket(hash
, sdp
, &name
);
758 spin_unlock_bucket(hash
);
759 kmem_cache_free(cachep
, gl
);
760 atomic_dec(&sdp
->sd_glock_disposal
);
763 hlist_bl_add_head_rcu(&gl
->gl_list
, &gl_hash_table
[hash
]);
764 spin_unlock_bucket(hash
);
773 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
775 * @state: the state we're requesting
776 * @flags: the modifier flags
777 * @gh: the holder structure
781 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
782 struct gfs2_holder
*gh
)
784 INIT_LIST_HEAD(&gh
->gh_list
);
786 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
787 gh
->gh_owner_pid
= get_pid(task_pid(current
));
788 gh
->gh_state
= state
;
789 gh
->gh_flags
= flags
;
796 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
797 * @state: the state we're requesting
798 * @flags: the modifier flags
799 * @gh: the holder structure
801 * Don't mess with the glock.
805 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
807 gh
->gh_state
= state
;
808 gh
->gh_flags
= flags
;
810 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
811 if (gh
->gh_owner_pid
)
812 put_pid(gh
->gh_owner_pid
);
813 gh
->gh_owner_pid
= get_pid(task_pid(current
));
817 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
818 * @gh: the holder structure
822 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
824 put_pid(gh
->gh_owner_pid
);
825 gfs2_glock_put(gh
->gh_gl
);
831 * gfs2_glock_holder_wait
834 * This function and gfs2_glock_demote_wait both show up in the WCHAN
835 * field. Thus I've separated these otherwise identical functions in
836 * order to be more informative to the user.
839 static int gfs2_glock_holder_wait(void *word
)
845 static int gfs2_glock_demote_wait(void *word
)
851 static void wait_on_holder(struct gfs2_holder
*gh
)
854 wait_on_bit(&gh
->gh_iflags
, HIF_WAIT
, gfs2_glock_holder_wait
, TASK_UNINTERRUPTIBLE
);
857 static void wait_on_demote(struct gfs2_glock
*gl
)
860 wait_on_bit(&gl
->gl_flags
, GLF_DEMOTE
, gfs2_glock_demote_wait
, TASK_UNINTERRUPTIBLE
);
864 * handle_callback - process a demote request
866 * @state: the state the caller wants us to change to
868 * There are only two requests that we are going to see in actual
869 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
872 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
,
875 int bit
= delay
? GLF_PENDING_DEMOTE
: GLF_DEMOTE
;
877 set_bit(bit
, &gl
->gl_flags
);
878 if (gl
->gl_demote_state
== LM_ST_EXCLUSIVE
) {
879 gl
->gl_demote_state
= state
;
880 gl
->gl_demote_time
= jiffies
;
881 } else if (gl
->gl_demote_state
!= LM_ST_UNLOCKED
&&
882 gl
->gl_demote_state
!= state
) {
883 gl
->gl_demote_state
= LM_ST_UNLOCKED
;
885 if (gl
->gl_ops
->go_callback
)
886 gl
->gl_ops
->go_callback(gl
);
887 trace_gfs2_demote_rq(gl
);
891 * gfs2_glock_wait - wait on a glock acquisition
892 * @gh: the glock holder
894 * Returns: 0 on success
897 int gfs2_glock_wait(struct gfs2_holder
*gh
)
903 void gfs2_print_dbg(struct seq_file
*seq
, const char *fmt
, ...)
905 struct va_format vaf
;
911 struct gfs2_glock_iter
*gi
= seq
->private;
912 vsprintf(gi
->string
, fmt
, args
);
913 seq_printf(seq
, gi
->string
);
918 printk(KERN_ERR
" %pV", &vaf
);
925 * add_to_queue - Add a holder to the wait queue (but look for recursion)
926 * @gh: the holder structure to add
928 * Eventually we should move the recursive locking trap to a
929 * debugging option or something like that. This is the fast
930 * path and needs to have the minimum number of distractions.
934 static inline void add_to_queue(struct gfs2_holder
*gh
)
935 __releases(&gl
->gl_spin
)
936 __acquires(&gl
->gl_spin
)
938 struct gfs2_glock
*gl
= gh
->gh_gl
;
939 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
940 struct list_head
*insert_pt
= NULL
;
941 struct gfs2_holder
*gh2
;
944 BUG_ON(gh
->gh_owner_pid
== NULL
);
945 if (test_and_set_bit(HIF_WAIT
, &gh
->gh_iflags
))
948 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
949 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
951 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
))
955 list_for_each_entry(gh2
, &gl
->gl_holders
, gh_list
) {
956 if (unlikely(gh2
->gh_owner_pid
== gh
->gh_owner_pid
&&
957 (gh
->gh_gl
->gl_ops
->go_type
!= LM_TYPE_FLOCK
)))
960 !(gh2
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) &&
961 !may_grant(gl
, gh
)) {
963 gh
->gh_error
= GLR_TRYFAILED
;
964 gfs2_holder_wake(gh
);
967 if (test_bit(HIF_HOLDER
, &gh2
->gh_iflags
))
969 if (unlikely((gh
->gh_flags
& LM_FLAG_PRIORITY
) && !insert_pt
))
970 insert_pt
= &gh2
->gh_list
;
972 set_bit(GLF_QUEUED
, &gl
->gl_flags
);
973 trace_gfs2_glock_queue(gh
, 1);
974 if (likely(insert_pt
== NULL
)) {
975 list_add_tail(&gh
->gh_list
, &gl
->gl_holders
);
976 if (unlikely(gh
->gh_flags
& LM_FLAG_PRIORITY
))
980 list_add_tail(&gh
->gh_list
, insert_pt
);
982 gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
, gh_list
);
983 if (!(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
984 spin_unlock(&gl
->gl_spin
);
985 if (sdp
->sd_lockstruct
.ls_ops
->lm_cancel
)
986 sdp
->sd_lockstruct
.ls_ops
->lm_cancel(gl
);
987 spin_lock(&gl
->gl_spin
);
992 print_symbol(KERN_ERR
"original: %s\n", gh2
->gh_ip
);
993 printk(KERN_ERR
"pid: %d\n", pid_nr(gh2
->gh_owner_pid
));
994 printk(KERN_ERR
"lock type: %d req lock state : %d\n",
995 gh2
->gh_gl
->gl_name
.ln_type
, gh2
->gh_state
);
996 print_symbol(KERN_ERR
"new: %s\n", gh
->gh_ip
);
997 printk(KERN_ERR
"pid: %d\n", pid_nr(gh
->gh_owner_pid
));
998 printk(KERN_ERR
"lock type: %d req lock state : %d\n",
999 gh
->gh_gl
->gl_name
.ln_type
, gh
->gh_state
);
1000 __dump_glock(NULL
, gl
);
1005 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1006 * @gh: the holder structure
1008 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1010 * Returns: 0, GLR_TRYFAILED, or errno on failure
1013 int gfs2_glock_nq(struct gfs2_holder
*gh
)
1015 struct gfs2_glock
*gl
= gh
->gh_gl
;
1016 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
1019 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
1022 if (test_bit(GLF_LRU
, &gl
->gl_flags
))
1023 gfs2_glock_remove_from_lru(gl
);
1025 spin_lock(&gl
->gl_spin
);
1027 if ((LM_FLAG_NOEXP
& gh
->gh_flags
) &&
1028 test_and_clear_bit(GLF_FROZEN
, &gl
->gl_flags
))
1029 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1031 spin_unlock(&gl
->gl_spin
);
1033 if (!(gh
->gh_flags
& GL_ASYNC
))
1034 error
= gfs2_glock_wait(gh
);
1040 * gfs2_glock_poll - poll to see if an async request has been completed
1043 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1046 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1048 return test_bit(HIF_WAIT
, &gh
->gh_iflags
) ? 0 : 1;
1052 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1053 * @gh: the glock holder
1057 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1059 struct gfs2_glock
*gl
= gh
->gh_gl
;
1060 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1064 spin_lock(&gl
->gl_spin
);
1065 if (gh
->gh_flags
& GL_NOCACHE
)
1066 handle_callback(gl
, LM_ST_UNLOCKED
, 0);
1068 list_del_init(&gh
->gh_list
);
1069 if (find_first_holder(gl
) == NULL
) {
1070 if (glops
->go_unlock
) {
1071 GLOCK_BUG_ON(gl
, test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
));
1072 spin_unlock(&gl
->gl_spin
);
1073 glops
->go_unlock(gh
);
1074 spin_lock(&gl
->gl_spin
);
1075 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1077 if (list_empty(&gl
->gl_holders
) &&
1078 !test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
1079 !test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1082 if (!test_bit(GLF_LFLUSH
, &gl
->gl_flags
))
1083 __gfs2_glock_schedule_for_reclaim(gl
);
1084 trace_gfs2_glock_queue(gh
, 0);
1085 spin_unlock(&gl
->gl_spin
);
1086 if (likely(fast_path
))
1089 gfs2_glock_hold(gl
);
1090 if (test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
1091 !test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1092 delay
= gl
->gl_ops
->go_min_hold_time
;
1093 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
1097 void gfs2_glock_dq_wait(struct gfs2_holder
*gh
)
1099 struct gfs2_glock
*gl
= gh
->gh_gl
;
1105 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1106 * @gh: the holder structure
1110 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1113 gfs2_holder_uninit(gh
);
1117 * gfs2_glock_nq_num - acquire a glock based on lock number
1118 * @sdp: the filesystem
1119 * @number: the lock number
1120 * @glops: the glock operations for the type of glock
1121 * @state: the state to acquire the glock in
1122 * @flags: modifier flags for the acquisition
1123 * @gh: the struct gfs2_holder
1128 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, u64 number
,
1129 const struct gfs2_glock_operations
*glops
,
1130 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1132 struct gfs2_glock
*gl
;
1135 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1137 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1145 * glock_compare - Compare two struct gfs2_glock structures for sorting
1146 * @arg_a: the first structure
1147 * @arg_b: the second structure
1151 static int glock_compare(const void *arg_a
, const void *arg_b
)
1153 const struct gfs2_holder
*gh_a
= *(const struct gfs2_holder
**)arg_a
;
1154 const struct gfs2_holder
*gh_b
= *(const struct gfs2_holder
**)arg_b
;
1155 const struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1156 const struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1158 if (a
->ln_number
> b
->ln_number
)
1160 if (a
->ln_number
< b
->ln_number
)
1162 BUG_ON(gh_a
->gh_gl
->gl_ops
->go_type
== gh_b
->gh_gl
->gl_ops
->go_type
);
1167 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1168 * @num_gh: the number of structures
1169 * @ghs: an array of struct gfs2_holder structures
1171 * Returns: 0 on success (all glocks acquired),
1172 * errno on failure (no glocks acquired)
1175 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1176 struct gfs2_holder
**p
)
1181 for (x
= 0; x
< num_gh
; x
++)
1184 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1186 for (x
= 0; x
< num_gh
; x
++) {
1187 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1189 error
= gfs2_glock_nq(p
[x
]);
1192 gfs2_glock_dq(p
[x
]);
1201 * gfs2_glock_nq_m - acquire multiple glocks
1202 * @num_gh: the number of structures
1203 * @ghs: an array of struct gfs2_holder structures
1206 * Returns: 0 on success (all glocks acquired),
1207 * errno on failure (no glocks acquired)
1210 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1212 struct gfs2_holder
*tmp
[4];
1213 struct gfs2_holder
**pph
= tmp
;
1220 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1221 return gfs2_glock_nq(ghs
);
1225 pph
= kmalloc(num_gh
* sizeof(struct gfs2_holder
*), GFP_NOFS
);
1230 error
= nq_m_sync(num_gh
, ghs
, pph
);
1239 * gfs2_glock_dq_m - release multiple glocks
1240 * @num_gh: the number of structures
1241 * @ghs: an array of struct gfs2_holder structures
1245 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1248 gfs2_glock_dq(&ghs
[num_gh
]);
1252 * gfs2_glock_dq_uninit_m - release multiple glocks
1253 * @num_gh: the number of structures
1254 * @ghs: an array of struct gfs2_holder structures
1258 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1261 gfs2_glock_dq_uninit(&ghs
[num_gh
]);
1264 void gfs2_glock_cb(struct gfs2_glock
*gl
, unsigned int state
)
1266 unsigned long delay
= 0;
1267 unsigned long holdtime
;
1268 unsigned long now
= jiffies
;
1270 gfs2_glock_hold(gl
);
1271 holdtime
= gl
->gl_tchange
+ gl
->gl_ops
->go_min_hold_time
;
1272 if (test_bit(GLF_QUEUED
, &gl
->gl_flags
)) {
1273 if (time_before(now
, holdtime
))
1274 delay
= holdtime
- now
;
1275 if (test_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
))
1276 delay
= gl
->gl_ops
->go_min_hold_time
;
1279 spin_lock(&gl
->gl_spin
);
1280 handle_callback(gl
, state
, delay
);
1281 spin_unlock(&gl
->gl_spin
);
1282 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
1287 * gfs2_should_freeze - Figure out if glock should be frozen
1288 * @gl: The glock in question
1290 * Glocks are not frozen if (a) the result of the dlm operation is
1291 * an error, (b) the locking operation was an unlock operation or
1292 * (c) if there is a "noexp" flagged request anywhere in the queue
1294 * Returns: 1 if freezing should occur, 0 otherwise
1297 static int gfs2_should_freeze(const struct gfs2_glock
*gl
)
1299 const struct gfs2_holder
*gh
;
1301 if (gl
->gl_reply
& ~LM_OUT_ST_MASK
)
1303 if (gl
->gl_target
== LM_ST_UNLOCKED
)
1306 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1307 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1309 if (LM_FLAG_NOEXP
& gh
->gh_flags
)
1317 * gfs2_glock_complete - Callback used by locking
1318 * @gl: Pointer to the glock
1319 * @ret: The return value from the dlm
1321 * The gl_reply field is under the gl_spin lock so that it is ok
1322 * to use a bitfield shared with other glock state fields.
1325 void gfs2_glock_complete(struct gfs2_glock
*gl
, int ret
)
1327 struct lm_lockstruct
*ls
= &gl
->gl_sbd
->sd_lockstruct
;
1329 spin_lock(&gl
->gl_spin
);
1332 if (unlikely(test_bit(DFL_BLOCK_LOCKS
, &ls
->ls_flags
))) {
1333 if (gfs2_should_freeze(gl
)) {
1334 set_bit(GLF_FROZEN
, &gl
->gl_flags
);
1335 spin_unlock(&gl
->gl_spin
);
1340 spin_unlock(&gl
->gl_spin
);
1341 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1343 gfs2_glock_hold(gl
);
1344 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1349 static int gfs2_shrink_glock_memory(struct shrinker
*shrink
,
1350 struct shrink_control
*sc
)
1352 struct gfs2_glock
*gl
;
1355 int nr
= sc
->nr_to_scan
;
1356 gfp_t gfp_mask
= sc
->gfp_mask
;
1362 if (!(gfp_mask
& __GFP_FS
))
1365 spin_lock(&lru_lock
);
1366 while(nr
&& !list_empty(&lru_list
)) {
1367 gl
= list_entry(lru_list
.next
, struct gfs2_glock
, gl_lru
);
1368 list_del_init(&gl
->gl_lru
);
1369 clear_bit(GLF_LRU
, &gl
->gl_flags
);
1370 atomic_dec(&lru_count
);
1372 /* Test for being demotable */
1373 if (!test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
1374 gfs2_glock_hold(gl
);
1375 spin_unlock(&lru_lock
);
1376 spin_lock(&gl
->gl_spin
);
1377 may_demote
= demote_ok(gl
);
1379 handle_callback(gl
, LM_ST_UNLOCKED
, 0);
1382 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1383 smp_mb__after_clear_bit();
1384 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1385 gfs2_glock_put_nolock(gl
);
1386 spin_unlock(&gl
->gl_spin
);
1387 spin_lock(&lru_lock
);
1391 list_add(&gl
->gl_lru
, &skipped
);
1392 set_bit(GLF_LRU
, &gl
->gl_flags
);
1394 list_splice(&skipped
, &lru_list
);
1395 atomic_add(nr_skipped
, &lru_count
);
1396 spin_unlock(&lru_lock
);
1398 return (atomic_read(&lru_count
) / 100) * sysctl_vfs_cache_pressure
;
1401 static struct shrinker glock_shrinker
= {
1402 .shrink
= gfs2_shrink_glock_memory
,
1403 .seeks
= DEFAULT_SEEKS
,
1407 * examine_bucket - Call a function for glock in a hash bucket
1408 * @examiner: the function
1409 * @sdp: the filesystem
1410 * @bucket: the bucket
1414 static void examine_bucket(glock_examiner examiner
, const struct gfs2_sbd
*sdp
,
1417 struct gfs2_glock
*gl
;
1418 struct hlist_bl_head
*head
= &gl_hash_table
[hash
];
1419 struct hlist_bl_node
*pos
;
1422 hlist_bl_for_each_entry_rcu(gl
, pos
, head
, gl_list
) {
1423 if ((gl
->gl_sbd
== sdp
) && atomic_read(&gl
->gl_ref
))
1430 static void glock_hash_walk(glock_examiner examiner
, const struct gfs2_sbd
*sdp
)
1434 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
1435 examine_bucket(examiner
, sdp
, x
);
1440 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1441 * @gl: The glock to thaw
1443 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1444 * so this has to result in the ref count being dropped by one.
1447 static void thaw_glock(struct gfs2_glock
*gl
)
1449 if (!test_and_clear_bit(GLF_FROZEN
, &gl
->gl_flags
))
1451 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1452 gfs2_glock_hold(gl
);
1453 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1458 * clear_glock - look at a glock and see if we can free it from glock cache
1459 * @gl: the glock to look at
1463 static void clear_glock(struct gfs2_glock
*gl
)
1465 gfs2_glock_remove_from_lru(gl
);
1467 spin_lock(&gl
->gl_spin
);
1468 if (gl
->gl_state
!= LM_ST_UNLOCKED
)
1469 handle_callback(gl
, LM_ST_UNLOCKED
, 0);
1470 spin_unlock(&gl
->gl_spin
);
1471 gfs2_glock_hold(gl
);
1472 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1477 * gfs2_glock_thaw - Thaw any frozen glocks
1478 * @sdp: The super block
1482 void gfs2_glock_thaw(struct gfs2_sbd
*sdp
)
1484 glock_hash_walk(thaw_glock
, sdp
);
1487 static int dump_glock(struct seq_file
*seq
, struct gfs2_glock
*gl
)
1490 spin_lock(&gl
->gl_spin
);
1491 ret
= __dump_glock(seq
, gl
);
1492 spin_unlock(&gl
->gl_spin
);
1496 static void dump_glock_func(struct gfs2_glock
*gl
)
1498 dump_glock(NULL
, gl
);
1502 * gfs2_gl_hash_clear - Empty out the glock hash table
1503 * @sdp: the filesystem
1504 * @wait: wait until it's all gone
1506 * Called when unmounting the filesystem.
1509 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
)
1511 glock_hash_walk(clear_glock
, sdp
);
1512 flush_workqueue(glock_workqueue
);
1513 wait_event(sdp
->sd_glock_wait
, atomic_read(&sdp
->sd_glock_disposal
) == 0);
1514 glock_hash_walk(dump_glock_func
, sdp
);
1517 void gfs2_glock_finish_truncate(struct gfs2_inode
*ip
)
1519 struct gfs2_glock
*gl
= ip
->i_gl
;
1522 ret
= gfs2_truncatei_resume(ip
);
1523 gfs2_assert_withdraw(gl
->gl_sbd
, ret
== 0);
1525 spin_lock(&gl
->gl_spin
);
1526 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1528 spin_unlock(&gl
->gl_spin
);
1531 static const char *state2str(unsigned state
)
1534 case LM_ST_UNLOCKED
:
1538 case LM_ST_DEFERRED
:
1540 case LM_ST_EXCLUSIVE
:
1546 static const char *hflags2str(char *buf
, unsigned flags
, unsigned long iflags
)
1549 if (flags
& LM_FLAG_TRY
)
1551 if (flags
& LM_FLAG_TRY_1CB
)
1553 if (flags
& LM_FLAG_NOEXP
)
1555 if (flags
& LM_FLAG_ANY
)
1557 if (flags
& LM_FLAG_PRIORITY
)
1559 if (flags
& GL_ASYNC
)
1561 if (flags
& GL_EXACT
)
1563 if (flags
& GL_NOCACHE
)
1565 if (test_bit(HIF_HOLDER
, &iflags
))
1567 if (test_bit(HIF_WAIT
, &iflags
))
1569 if (test_bit(HIF_FIRST
, &iflags
))
1576 * dump_holder - print information about a glock holder
1577 * @seq: the seq_file struct
1578 * @gh: the glock holder
1580 * Returns: 0 on success, -ENOBUFS when we run out of space
1583 static int dump_holder(struct seq_file
*seq
, const struct gfs2_holder
*gh
)
1585 struct task_struct
*gh_owner
= NULL
;
1588 if (gh
->gh_owner_pid
)
1589 gh_owner
= pid_task(gh
->gh_owner_pid
, PIDTYPE_PID
);
1590 gfs2_print_dbg(seq
, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1591 state2str(gh
->gh_state
),
1592 hflags2str(flags_buf
, gh
->gh_flags
, gh
->gh_iflags
),
1594 gh
->gh_owner_pid
? (long)pid_nr(gh
->gh_owner_pid
) : -1,
1595 gh_owner
? gh_owner
->comm
: "(ended)",
1600 static const char *gflags2str(char *buf
, const struct gfs2_glock
*gl
)
1602 const unsigned long *gflags
= &gl
->gl_flags
;
1605 if (test_bit(GLF_LOCK
, gflags
))
1607 if (test_bit(GLF_DEMOTE
, gflags
))
1609 if (test_bit(GLF_PENDING_DEMOTE
, gflags
))
1611 if (test_bit(GLF_DEMOTE_IN_PROGRESS
, gflags
))
1613 if (test_bit(GLF_DIRTY
, gflags
))
1615 if (test_bit(GLF_LFLUSH
, gflags
))
1617 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, gflags
))
1619 if (test_bit(GLF_REPLY_PENDING
, gflags
))
1621 if (test_bit(GLF_INITIAL
, gflags
))
1623 if (test_bit(GLF_FROZEN
, gflags
))
1625 if (test_bit(GLF_QUEUED
, gflags
))
1627 if (test_bit(GLF_LRU
, gflags
))
1636 * __dump_glock - print information about a glock
1637 * @seq: The seq_file struct
1640 * The file format is as follows:
1641 * One line per object, capital letters are used to indicate objects
1642 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1643 * other objects are indented by a single space and follow the glock to
1644 * which they are related. Fields are indicated by lower case letters
1645 * followed by a colon and the field value, except for strings which are in
1646 * [] so that its possible to see if they are composed of spaces for
1647 * example. The field's are n = number (id of the object), f = flags,
1648 * t = type, s = state, r = refcount, e = error, p = pid.
1650 * Returns: 0 on success, -ENOBUFS when we run out of space
1653 static int __dump_glock(struct seq_file
*seq
, const struct gfs2_glock
*gl
)
1655 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1656 unsigned long long dtime
;
1657 const struct gfs2_holder
*gh
;
1658 char gflags_buf
[32];
1661 dtime
= jiffies
- gl
->gl_demote_time
;
1662 dtime
*= 1000000/HZ
; /* demote time in uSec */
1663 if (!test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1665 gfs2_print_dbg(seq
, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d\n",
1666 state2str(gl
->gl_state
),
1667 gl
->gl_name
.ln_type
,
1668 (unsigned long long)gl
->gl_name
.ln_number
,
1669 gflags2str(gflags_buf
, gl
),
1670 state2str(gl
->gl_target
),
1671 state2str(gl
->gl_demote_state
), dtime
,
1672 atomic_read(&gl
->gl_ail_count
),
1673 atomic_read(&gl
->gl_revokes
),
1674 atomic_read(&gl
->gl_ref
));
1676 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1677 error
= dump_holder(seq
, gh
);
1681 if (gl
->gl_state
!= LM_ST_UNLOCKED
&& glops
->go_dump
)
1682 error
= glops
->go_dump(seq
, gl
);
1690 int __init
gfs2_glock_init(void)
1693 for(i
= 0; i
< GFS2_GL_HASH_SIZE
; i
++) {
1694 INIT_HLIST_BL_HEAD(&gl_hash_table
[i
]);
1697 glock_workqueue
= alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM
|
1698 WQ_HIGHPRI
| WQ_FREEZABLE
, 0);
1699 if (IS_ERR(glock_workqueue
))
1700 return PTR_ERR(glock_workqueue
);
1701 gfs2_delete_workqueue
= alloc_workqueue("delete_workqueue",
1702 WQ_MEM_RECLAIM
| WQ_FREEZABLE
,
1704 if (IS_ERR(gfs2_delete_workqueue
)) {
1705 destroy_workqueue(glock_workqueue
);
1706 return PTR_ERR(gfs2_delete_workqueue
);
1709 register_shrinker(&glock_shrinker
);
1714 void gfs2_glock_exit(void)
1716 unregister_shrinker(&glock_shrinker
);
1717 destroy_workqueue(glock_workqueue
);
1718 destroy_workqueue(gfs2_delete_workqueue
);
1721 static inline struct gfs2_glock
*glock_hash_chain(unsigned hash
)
1723 return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table
[hash
]),
1724 struct gfs2_glock
, gl_list
);
1727 static inline struct gfs2_glock
*glock_hash_next(struct gfs2_glock
*gl
)
1729 return hlist_bl_entry(rcu_dereference(gl
->gl_list
.next
),
1730 struct gfs2_glock
, gl_list
);
1733 static int gfs2_glock_iter_next(struct gfs2_glock_iter
*gi
)
1735 struct gfs2_glock
*gl
;
1740 gi
->gl
= glock_hash_next(gl
);
1742 gi
->gl
= glock_hash_chain(gi
->hash
);
1744 while (gi
->gl
== NULL
) {
1746 if (gi
->hash
>= GFS2_GL_HASH_SIZE
) {
1750 gi
->gl
= glock_hash_chain(gi
->hash
);
1752 /* Skip entries for other sb and dead entries */
1753 } while (gi
->sdp
!= gi
->gl
->gl_sbd
|| atomic_read(&gi
->gl
->gl_ref
) == 0);
1758 static void *gfs2_glock_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1760 struct gfs2_glock_iter
*gi
= seq
->private;
1767 if (gfs2_glock_iter_next(gi
))
1774 static void *gfs2_glock_seq_next(struct seq_file
*seq
, void *iter_ptr
,
1777 struct gfs2_glock_iter
*gi
= seq
->private;
1781 if (gfs2_glock_iter_next(gi
))
1787 static void gfs2_glock_seq_stop(struct seq_file
*seq
, void *iter_ptr
)
1789 struct gfs2_glock_iter
*gi
= seq
->private;
1796 static int gfs2_glock_seq_show(struct seq_file
*seq
, void *iter_ptr
)
1798 return dump_glock(seq
, iter_ptr
);
1801 static const struct seq_operations gfs2_glock_seq_ops
= {
1802 .start
= gfs2_glock_seq_start
,
1803 .next
= gfs2_glock_seq_next
,
1804 .stop
= gfs2_glock_seq_stop
,
1805 .show
= gfs2_glock_seq_show
,
1808 static int gfs2_debugfs_open(struct inode
*inode
, struct file
*file
)
1810 int ret
= seq_open_private(file
, &gfs2_glock_seq_ops
,
1811 sizeof(struct gfs2_glock_iter
));
1813 struct seq_file
*seq
= file
->private_data
;
1814 struct gfs2_glock_iter
*gi
= seq
->private;
1815 gi
->sdp
= inode
->i_private
;
1820 static const struct file_operations gfs2_debug_fops
= {
1821 .owner
= THIS_MODULE
,
1822 .open
= gfs2_debugfs_open
,
1824 .llseek
= seq_lseek
,
1825 .release
= seq_release_private
,
1828 int gfs2_create_debugfs_file(struct gfs2_sbd
*sdp
)
1830 sdp
->debugfs_dir
= debugfs_create_dir(sdp
->sd_table_name
, gfs2_root
);
1831 if (!sdp
->debugfs_dir
)
1833 sdp
->debugfs_dentry_glocks
= debugfs_create_file("glocks",
1835 sdp
->debugfs_dir
, sdp
,
1837 if (!sdp
->debugfs_dentry_glocks
)
1843 void gfs2_delete_debugfs_file(struct gfs2_sbd
*sdp
)
1845 if (sdp
&& sdp
->debugfs_dir
) {
1846 if (sdp
->debugfs_dentry_glocks
) {
1847 debugfs_remove(sdp
->debugfs_dentry_glocks
);
1848 sdp
->debugfs_dentry_glocks
= NULL
;
1850 debugfs_remove(sdp
->debugfs_dir
);
1851 sdp
->debugfs_dir
= NULL
;
1855 int gfs2_register_debugfs(void)
1857 gfs2_root
= debugfs_create_dir("gfs2", NULL
);
1858 return gfs2_root
? 0 : -ENOMEM
;
1861 void gfs2_unregister_debugfs(void)
1863 debugfs_remove(gfs2_root
);