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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/buffer_head.h>
16 #include <linux/delay.h>
17 #include <linux/sort.h>
18 #include <linux/jhash.h>
19 #include <linux/kallsyms.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <linux/list.h>
22 #include <linux/wait.h>
23 #include <linux/module.h>
24 #include <asm/uaccess.h>
25 #include <linux/seq_file.h>
26 #include <linux/debugfs.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/workqueue.h>
30 #include <linux/jiffies.h>
31 #include <linux/rcupdate.h>
32 #include <linux/rculist_bl.h>
33 #include <linux/bit_spinlock.h>
34 #include <linux/percpu.h>
35 #include <linux/list_sort.h>
36 #include <linux/lockref.h>
37 #include <linux/rhashtable.h>
50 #define CREATE_TRACE_POINTS
51 #include "trace_gfs2.h"
53 struct gfs2_glock_iter
{
54 struct gfs2_sbd
*sdp
; /* incore superblock */
55 struct rhashtable_iter hti
; /* rhashtable iterator */
56 struct gfs2_glock
*gl
; /* current glock struct */
57 loff_t last_pos
; /* last position */
60 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
62 static void do_xmote(struct gfs2_glock
*gl
, struct gfs2_holder
*gh
, unsigned int target
);
64 static struct dentry
*gfs2_root
;
65 static struct workqueue_struct
*glock_workqueue
;
66 struct workqueue_struct
*gfs2_delete_workqueue
;
67 static LIST_HEAD(lru_list
);
68 static atomic_t lru_count
= ATOMIC_INIT(0);
69 static DEFINE_SPINLOCK(lru_lock
);
71 #define GFS2_GL_HASH_SHIFT 15
72 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
74 static struct rhashtable_params ht_parms
= {
75 .nelem_hint
= GFS2_GL_HASH_SIZE
* 3 / 4,
76 .key_len
= sizeof(struct lm_lockname
),
77 .key_offset
= offsetof(struct gfs2_glock
, gl_name
),
78 .head_offset
= offsetof(struct gfs2_glock
, gl_node
),
81 static struct rhashtable gl_hash_table
;
83 void gfs2_glock_free(struct gfs2_glock
*gl
)
85 struct gfs2_sbd
*sdp
= gl
->gl_name
.ln_sbd
;
87 if (gl
->gl_ops
->go_flags
& GLOF_ASPACE
) {
88 kmem_cache_free(gfs2_glock_aspace_cachep
, gl
);
90 kfree(gl
->gl_lksb
.sb_lvbptr
);
91 kmem_cache_free(gfs2_glock_cachep
, gl
);
93 if (atomic_dec_and_test(&sdp
->sd_glock_disposal
))
94 wake_up(&sdp
->sd_glock_wait
);
98 * gfs2_glock_hold() - increment reference count on glock
99 * @gl: The glock to hold
103 static void gfs2_glock_hold(struct gfs2_glock
*gl
)
105 GLOCK_BUG_ON(gl
, __lockref_is_dead(&gl
->gl_lockref
));
106 lockref_get(&gl
->gl_lockref
);
110 * demote_ok - Check to see if it's ok to unlock a glock
113 * Returns: 1 if it's ok
116 static int demote_ok(const struct gfs2_glock
*gl
)
118 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
120 if (gl
->gl_state
== LM_ST_UNLOCKED
)
122 if (!list_empty(&gl
->gl_holders
))
124 if (glops
->go_demote_ok
)
125 return glops
->go_demote_ok(gl
);
130 void gfs2_glock_add_to_lru(struct gfs2_glock
*gl
)
132 spin_lock(&lru_lock
);
134 if (!list_empty(&gl
->gl_lru
))
135 list_del_init(&gl
->gl_lru
);
137 atomic_inc(&lru_count
);
139 list_add_tail(&gl
->gl_lru
, &lru_list
);
140 set_bit(GLF_LRU
, &gl
->gl_flags
);
141 spin_unlock(&lru_lock
);
144 static void gfs2_glock_remove_from_lru(struct gfs2_glock
*gl
)
146 spin_lock(&lru_lock
);
147 if (!list_empty(&gl
->gl_lru
)) {
148 list_del_init(&gl
->gl_lru
);
149 atomic_dec(&lru_count
);
150 clear_bit(GLF_LRU
, &gl
->gl_flags
);
152 spin_unlock(&lru_lock
);
156 * gfs2_glock_put() - Decrement reference count on glock
157 * @gl: The glock to put
161 void gfs2_glock_put(struct gfs2_glock
*gl
)
163 struct gfs2_sbd
*sdp
= gl
->gl_name
.ln_sbd
;
164 struct address_space
*mapping
= gfs2_glock2aspace(gl
);
166 if (lockref_put_or_lock(&gl
->gl_lockref
))
169 lockref_mark_dead(&gl
->gl_lockref
);
171 gfs2_glock_remove_from_lru(gl
);
172 spin_unlock(&gl
->gl_lockref
.lock
);
173 rhashtable_remove_fast(&gl_hash_table
, &gl
->gl_node
, ht_parms
);
174 GLOCK_BUG_ON(gl
, !list_empty(&gl
->gl_holders
));
175 GLOCK_BUG_ON(gl
, mapping
&& mapping
->nrpages
);
176 trace_gfs2_glock_put(gl
);
177 sdp
->sd_lockstruct
.ls_ops
->lm_put_lock(gl
);
181 * may_grant - check if its ok to grant a new lock
183 * @gh: The lock request which we wish to grant
185 * Returns: true if its ok to grant the lock
188 static inline int may_grant(const struct gfs2_glock
*gl
, const struct gfs2_holder
*gh
)
190 const struct gfs2_holder
*gh_head
= list_entry(gl
->gl_holders
.next
, const struct gfs2_holder
, gh_list
);
191 if ((gh
->gh_state
== LM_ST_EXCLUSIVE
||
192 gh_head
->gh_state
== LM_ST_EXCLUSIVE
) && gh
!= gh_head
)
194 if (gl
->gl_state
== gh
->gh_state
)
196 if (gh
->gh_flags
& GL_EXACT
)
198 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
199 if (gh
->gh_state
== LM_ST_SHARED
&& gh_head
->gh_state
== LM_ST_SHARED
)
201 if (gh
->gh_state
== LM_ST_DEFERRED
&& gh_head
->gh_state
== LM_ST_DEFERRED
)
204 if (gl
->gl_state
!= LM_ST_UNLOCKED
&& (gh
->gh_flags
& LM_FLAG_ANY
))
209 static void gfs2_holder_wake(struct gfs2_holder
*gh
)
211 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
212 smp_mb__after_atomic();
213 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
217 * do_error - Something unexpected has happened during a lock request
221 static inline void do_error(struct gfs2_glock
*gl
, const int ret
)
223 struct gfs2_holder
*gh
, *tmp
;
225 list_for_each_entry_safe(gh
, tmp
, &gl
->gl_holders
, gh_list
) {
226 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
228 if (ret
& LM_OUT_ERROR
)
230 else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))
231 gh
->gh_error
= GLR_TRYFAILED
;
234 list_del_init(&gh
->gh_list
);
235 trace_gfs2_glock_queue(gh
, 0);
236 gfs2_holder_wake(gh
);
241 * do_promote - promote as many requests as possible on the current queue
244 * Returns: 1 if there is a blocked holder at the head of the list, or 2
245 * if a type specific operation is underway.
248 static int do_promote(struct gfs2_glock
*gl
)
249 __releases(&gl
->gl_lockref
.lock
)
250 __acquires(&gl
->gl_lockref
.lock
)
252 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
253 struct gfs2_holder
*gh
, *tmp
;
257 list_for_each_entry_safe(gh
, tmp
, &gl
->gl_holders
, gh_list
) {
258 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
260 if (may_grant(gl
, gh
)) {
261 if (gh
->gh_list
.prev
== &gl
->gl_holders
&&
263 spin_unlock(&gl
->gl_lockref
.lock
);
264 /* FIXME: eliminate this eventually */
265 ret
= glops
->go_lock(gh
);
266 spin_lock(&gl
->gl_lockref
.lock
);
271 list_del_init(&gh
->gh_list
);
272 trace_gfs2_glock_queue(gh
, 0);
273 gfs2_holder_wake(gh
);
276 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
277 trace_gfs2_promote(gh
, 1);
278 gfs2_holder_wake(gh
);
281 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
282 trace_gfs2_promote(gh
, 0);
283 gfs2_holder_wake(gh
);
286 if (gh
->gh_list
.prev
== &gl
->gl_holders
)
295 * find_first_waiter - find the first gh that's waiting for the glock
299 static inline struct gfs2_holder
*find_first_waiter(const struct gfs2_glock
*gl
)
301 struct gfs2_holder
*gh
;
303 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
304 if (!test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
311 * state_change - record that the glock is now in a different state
313 * @new_state the new state
317 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
321 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
322 held2
= (new_state
!= LM_ST_UNLOCKED
);
324 if (held1
!= held2
) {
325 GLOCK_BUG_ON(gl
, __lockref_is_dead(&gl
->gl_lockref
));
327 gl
->gl_lockref
.count
++;
329 gl
->gl_lockref
.count
--;
331 if (held1
&& held2
&& list_empty(&gl
->gl_holders
))
332 clear_bit(GLF_QUEUED
, &gl
->gl_flags
);
334 if (new_state
!= gl
->gl_target
)
335 /* shorten our minimum hold time */
336 gl
->gl_hold_time
= max(gl
->gl_hold_time
- GL_GLOCK_HOLD_DECR
,
338 gl
->gl_state
= new_state
;
339 gl
->gl_tchange
= jiffies
;
342 static void gfs2_demote_wake(struct gfs2_glock
*gl
)
344 gl
->gl_demote_state
= LM_ST_EXCLUSIVE
;
345 clear_bit(GLF_DEMOTE
, &gl
->gl_flags
);
346 smp_mb__after_atomic();
347 wake_up_bit(&gl
->gl_flags
, GLF_DEMOTE
);
351 * finish_xmote - The DLM has replied to one of our lock requests
353 * @ret: The status from the DLM
357 static void finish_xmote(struct gfs2_glock
*gl
, unsigned int ret
)
359 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
360 struct gfs2_holder
*gh
;
361 unsigned state
= ret
& LM_OUT_ST_MASK
;
364 spin_lock(&gl
->gl_lockref
.lock
);
365 trace_gfs2_glock_state_change(gl
, state
);
366 state_change(gl
, state
);
367 gh
= find_first_waiter(gl
);
369 /* Demote to UN request arrived during demote to SH or DF */
370 if (test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
) &&
371 state
!= LM_ST_UNLOCKED
&& gl
->gl_demote_state
== LM_ST_UNLOCKED
)
372 gl
->gl_target
= LM_ST_UNLOCKED
;
374 /* Check for state != intended state */
375 if (unlikely(state
!= gl
->gl_target
)) {
376 if (gh
&& !test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
)) {
377 /* move to back of queue and try next entry */
378 if (ret
& LM_OUT_CANCELED
) {
379 if ((gh
->gh_flags
& LM_FLAG_PRIORITY
) == 0)
380 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
381 gh
= find_first_waiter(gl
);
382 gl
->gl_target
= gh
->gh_state
;
385 /* Some error or failed "try lock" - report it */
386 if ((ret
& LM_OUT_ERROR
) ||
387 (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))) {
388 gl
->gl_target
= gl
->gl_state
;
394 /* Unlocked due to conversion deadlock, try again */
397 do_xmote(gl
, gh
, gl
->gl_target
);
399 /* Conversion fails, unlock and try again */
402 do_xmote(gl
, gh
, LM_ST_UNLOCKED
);
404 default: /* Everything else */
405 pr_err("wanted %u got %u\n", gl
->gl_target
, state
);
408 spin_unlock(&gl
->gl_lockref
.lock
);
412 /* Fast path - we got what we asked for */
413 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
))
414 gfs2_demote_wake(gl
);
415 if (state
!= LM_ST_UNLOCKED
) {
416 if (glops
->go_xmote_bh
) {
417 spin_unlock(&gl
->gl_lockref
.lock
);
418 rv
= glops
->go_xmote_bh(gl
, gh
);
419 spin_lock(&gl
->gl_lockref
.lock
);
430 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
432 spin_unlock(&gl
->gl_lockref
.lock
);
436 * do_xmote - Calls the DLM to change the state of a lock
437 * @gl: The lock state
438 * @gh: The holder (only for promotes)
439 * @target: The target lock state
443 static void do_xmote(struct gfs2_glock
*gl
, struct gfs2_holder
*gh
, unsigned int target
)
444 __releases(&gl
->gl_lockref
.lock
)
445 __acquires(&gl
->gl_lockref
.lock
)
447 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
448 struct gfs2_sbd
*sdp
= gl
->gl_name
.ln_sbd
;
449 unsigned int lck_flags
= (unsigned int)(gh
? gh
->gh_flags
: 0);
452 lck_flags
&= (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
| LM_FLAG_NOEXP
|
454 GLOCK_BUG_ON(gl
, gl
->gl_state
== target
);
455 GLOCK_BUG_ON(gl
, gl
->gl_state
== gl
->gl_target
);
456 if ((target
== LM_ST_UNLOCKED
|| target
== LM_ST_DEFERRED
) &&
458 set_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
);
459 do_error(gl
, 0); /* Fail queued try locks */
462 set_bit(GLF_BLOCKING
, &gl
->gl_flags
);
463 if ((gl
->gl_req
== LM_ST_UNLOCKED
) ||
464 (gl
->gl_state
== LM_ST_EXCLUSIVE
) ||
465 (lck_flags
& (LM_FLAG_TRY
|LM_FLAG_TRY_1CB
)))
466 clear_bit(GLF_BLOCKING
, &gl
->gl_flags
);
467 spin_unlock(&gl
->gl_lockref
.lock
);
470 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
))
471 glops
->go_inval(gl
, target
== LM_ST_DEFERRED
? 0 : DIO_METADATA
);
472 clear_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
);
475 if (sdp
->sd_lockstruct
.ls_ops
->lm_lock
) {
477 ret
= sdp
->sd_lockstruct
.ls_ops
->lm_lock(gl
, target
, lck_flags
);
479 pr_err("lm_lock ret %d\n", ret
);
482 } else { /* lock_nolock */
483 finish_xmote(gl
, target
);
484 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
488 spin_lock(&gl
->gl_lockref
.lock
);
492 * find_first_holder - find the first "holder" gh
496 static inline struct gfs2_holder
*find_first_holder(const struct gfs2_glock
*gl
)
498 struct gfs2_holder
*gh
;
500 if (!list_empty(&gl
->gl_holders
)) {
501 gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
, gh_list
);
502 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
509 * run_queue - do all outstanding tasks related to a glock
510 * @gl: The glock in question
511 * @nonblock: True if we must not block in run_queue
515 static void run_queue(struct gfs2_glock
*gl
, const int nonblock
)
516 __releases(&gl
->gl_lockref
.lock
)
517 __acquires(&gl
->gl_lockref
.lock
)
519 struct gfs2_holder
*gh
= NULL
;
522 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
525 GLOCK_BUG_ON(gl
, test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
));
527 if (test_bit(GLF_DEMOTE
, &gl
->gl_flags
) &&
528 gl
->gl_demote_state
!= gl
->gl_state
) {
529 if (find_first_holder(gl
))
533 set_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
);
534 GLOCK_BUG_ON(gl
, gl
->gl_demote_state
== LM_ST_EXCLUSIVE
);
535 gl
->gl_target
= gl
->gl_demote_state
;
537 if (test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
538 gfs2_demote_wake(gl
);
539 ret
= do_promote(gl
);
544 gh
= find_first_waiter(gl
);
545 gl
->gl_target
= gh
->gh_state
;
546 if (!(gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)))
547 do_error(gl
, 0); /* Fail queued try locks */
549 do_xmote(gl
, gh
, gl
->gl_target
);
554 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
555 smp_mb__after_atomic();
556 gl
->gl_lockref
.count
++;
557 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
558 gl
->gl_lockref
.count
--;
562 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
563 smp_mb__after_atomic();
567 static void delete_work_func(struct work_struct
*work
)
569 struct gfs2_glock
*gl
= container_of(work
, struct gfs2_glock
, gl_delete
);
570 struct gfs2_sbd
*sdp
= gl
->gl_name
.ln_sbd
;
571 struct gfs2_inode
*ip
;
573 u64 no_addr
= gl
->gl_name
.ln_number
;
576 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
579 inode
= gfs2_ilookup(sdp
->sd_vfs
, no_addr
, 1);
581 inode
= gfs2_lookup_by_inum(sdp
, no_addr
, NULL
, GFS2_BLKST_UNLINKED
);
582 if (inode
&& !IS_ERR(inode
)) {
583 d_prune_aliases(inode
);
589 static void glock_work_func(struct work_struct
*work
)
591 unsigned long delay
= 0;
592 struct gfs2_glock
*gl
= container_of(work
, struct gfs2_glock
, gl_work
.work
);
595 if (test_and_clear_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
)) {
596 finish_xmote(gl
, gl
->gl_reply
);
599 spin_lock(&gl
->gl_lockref
.lock
);
600 if (test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
601 gl
->gl_state
!= LM_ST_UNLOCKED
&&
602 gl
->gl_demote_state
!= LM_ST_EXCLUSIVE
) {
603 unsigned long holdtime
, now
= jiffies
;
605 holdtime
= gl
->gl_tchange
+ gl
->gl_hold_time
;
606 if (time_before(now
, holdtime
))
607 delay
= holdtime
- now
;
610 clear_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
);
611 set_bit(GLF_DEMOTE
, &gl
->gl_flags
);
615 spin_unlock(&gl
->gl_lockref
.lock
);
619 if (gl
->gl_name
.ln_type
!= LM_TYPE_INODE
)
621 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
629 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
630 * @sdp: The GFS2 superblock
631 * @number: the lock number
632 * @glops: The glock_operations to use
633 * @create: If 0, don't create the glock if it doesn't exist
634 * @glp: the glock is returned here
636 * This does not lock a glock, just finds/creates structures for one.
641 int gfs2_glock_get(struct gfs2_sbd
*sdp
, u64 number
,
642 const struct gfs2_glock_operations
*glops
, int create
,
643 struct gfs2_glock
**glp
)
645 struct super_block
*s
= sdp
->sd_vfs
;
646 struct lm_lockname name
= { .ln_number
= number
,
647 .ln_type
= glops
->go_type
,
649 struct gfs2_glock
*gl
, *tmp
= NULL
;
650 struct address_space
*mapping
;
651 struct kmem_cache
*cachep
;
654 gl
= rhashtable_lookup_fast(&gl_hash_table
, &name
, ht_parms
);
655 if (gl
&& !lockref_get_not_dead(&gl
->gl_lockref
))
664 if (glops
->go_flags
& GLOF_ASPACE
)
665 cachep
= gfs2_glock_aspace_cachep
;
667 cachep
= gfs2_glock_cachep
;
668 gl
= kmem_cache_alloc(cachep
, GFP_NOFS
);
672 memset(&gl
->gl_lksb
, 0, sizeof(struct dlm_lksb
));
674 if (glops
->go_flags
& GLOF_LVB
) {
675 gl
->gl_lksb
.sb_lvbptr
= kzalloc(GFS2_MIN_LVB_SIZE
, GFP_NOFS
);
676 if (!gl
->gl_lksb
.sb_lvbptr
) {
677 kmem_cache_free(cachep
, gl
);
682 atomic_inc(&sdp
->sd_glock_disposal
);
683 gl
->gl_node
.next
= NULL
;
686 gl
->gl_lockref
.count
= 1;
687 gl
->gl_state
= LM_ST_UNLOCKED
;
688 gl
->gl_target
= LM_ST_UNLOCKED
;
689 gl
->gl_demote_state
= LM_ST_EXCLUSIVE
;
691 gl
->gl_dstamp
= ktime_set(0, 0);
693 /* We use the global stats to estimate the initial per-glock stats */
694 gl
->gl_stats
= this_cpu_ptr(sdp
->sd_lkstats
)->lkstats
[glops
->go_type
];
696 gl
->gl_stats
.stats
[GFS2_LKS_DCOUNT
] = 0;
697 gl
->gl_stats
.stats
[GFS2_LKS_QCOUNT
] = 0;
698 gl
->gl_tchange
= jiffies
;
699 gl
->gl_object
= NULL
;
700 gl
->gl_hold_time
= GL_GLOCK_DFT_HOLD
;
701 INIT_DELAYED_WORK(&gl
->gl_work
, glock_work_func
);
702 INIT_WORK(&gl
->gl_delete
, delete_work_func
);
704 mapping
= gfs2_glock2aspace(gl
);
706 mapping
->a_ops
= &gfs2_meta_aops
;
707 mapping
->host
= s
->s_bdev
->bd_inode
;
709 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
710 mapping
->private_data
= NULL
;
711 mapping
->writeback_index
= 0;
715 ret
= rhashtable_lookup_insert_fast(&gl_hash_table
, &gl
->gl_node
,
722 if (ret
== -EEXIST
) {
724 tmp
= rhashtable_lookup_fast(&gl_hash_table
, &name
, ht_parms
);
725 if (tmp
== NULL
|| !lockref_get_not_dead(&tmp
->gl_lockref
)) {
736 kfree(gl
->gl_lksb
.sb_lvbptr
);
737 kmem_cache_free(cachep
, gl
);
738 atomic_dec(&sdp
->sd_glock_disposal
);
745 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
747 * @state: the state we're requesting
748 * @flags: the modifier flags
749 * @gh: the holder structure
753 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, u16 flags
,
754 struct gfs2_holder
*gh
)
756 INIT_LIST_HEAD(&gh
->gh_list
);
758 gh
->gh_ip
= _RET_IP_
;
759 gh
->gh_owner_pid
= get_pid(task_pid(current
));
760 gh
->gh_state
= state
;
761 gh
->gh_flags
= flags
;
768 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
769 * @state: the state we're requesting
770 * @flags: the modifier flags
771 * @gh: the holder structure
773 * Don't mess with the glock.
777 void gfs2_holder_reinit(unsigned int state
, u16 flags
, struct gfs2_holder
*gh
)
779 gh
->gh_state
= state
;
780 gh
->gh_flags
= flags
;
782 gh
->gh_ip
= _RET_IP_
;
783 put_pid(gh
->gh_owner_pid
);
784 gh
->gh_owner_pid
= get_pid(task_pid(current
));
788 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
789 * @gh: the holder structure
793 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
795 put_pid(gh
->gh_owner_pid
);
796 gfs2_glock_put(gh
->gh_gl
);
802 * gfs2_glock_wait - wait on a glock acquisition
803 * @gh: the glock holder
805 * Returns: 0 on success
808 int gfs2_glock_wait(struct gfs2_holder
*gh
)
810 unsigned long time1
= jiffies
;
813 wait_on_bit(&gh
->gh_iflags
, HIF_WAIT
, TASK_UNINTERRUPTIBLE
);
814 if (time_after(jiffies
, time1
+ HZ
)) /* have we waited > a second? */
815 /* Lengthen the minimum hold time. */
816 gh
->gh_gl
->gl_hold_time
= min(gh
->gh_gl
->gl_hold_time
+
823 * handle_callback - process a demote request
825 * @state: the state the caller wants us to change to
827 * There are only two requests that we are going to see in actual
828 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
831 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
,
832 unsigned long delay
, bool remote
)
834 int bit
= delay
? GLF_PENDING_DEMOTE
: GLF_DEMOTE
;
836 set_bit(bit
, &gl
->gl_flags
);
837 if (gl
->gl_demote_state
== LM_ST_EXCLUSIVE
) {
838 gl
->gl_demote_state
= state
;
839 gl
->gl_demote_time
= jiffies
;
840 } else if (gl
->gl_demote_state
!= LM_ST_UNLOCKED
&&
841 gl
->gl_demote_state
!= state
) {
842 gl
->gl_demote_state
= LM_ST_UNLOCKED
;
844 if (gl
->gl_ops
->go_callback
)
845 gl
->gl_ops
->go_callback(gl
, remote
);
846 trace_gfs2_demote_rq(gl
, remote
);
849 void gfs2_print_dbg(struct seq_file
*seq
, const char *fmt
, ...)
851 struct va_format vaf
;
857 seq_vprintf(seq
, fmt
, args
);
869 * add_to_queue - Add a holder to the wait queue (but look for recursion)
870 * @gh: the holder structure to add
872 * Eventually we should move the recursive locking trap to a
873 * debugging option or something like that. This is the fast
874 * path and needs to have the minimum number of distractions.
878 static inline void add_to_queue(struct gfs2_holder
*gh
)
879 __releases(&gl
->gl_lockref
.lock
)
880 __acquires(&gl
->gl_lockref
.lock
)
882 struct gfs2_glock
*gl
= gh
->gh_gl
;
883 struct gfs2_sbd
*sdp
= gl
->gl_name
.ln_sbd
;
884 struct list_head
*insert_pt
= NULL
;
885 struct gfs2_holder
*gh2
;
888 BUG_ON(gh
->gh_owner_pid
== NULL
);
889 if (test_and_set_bit(HIF_WAIT
, &gh
->gh_iflags
))
892 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
893 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
894 try_futile
= !may_grant(gl
, gh
);
895 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
))
899 list_for_each_entry(gh2
, &gl
->gl_holders
, gh_list
) {
900 if (unlikely(gh2
->gh_owner_pid
== gh
->gh_owner_pid
&&
901 (gh
->gh_gl
->gl_ops
->go_type
!= LM_TYPE_FLOCK
)))
904 !(gh2
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))) {
906 gh
->gh_error
= GLR_TRYFAILED
;
907 gfs2_holder_wake(gh
);
910 if (test_bit(HIF_HOLDER
, &gh2
->gh_iflags
))
912 if (unlikely((gh
->gh_flags
& LM_FLAG_PRIORITY
) && !insert_pt
))
913 insert_pt
= &gh2
->gh_list
;
915 set_bit(GLF_QUEUED
, &gl
->gl_flags
);
916 trace_gfs2_glock_queue(gh
, 1);
917 gfs2_glstats_inc(gl
, GFS2_LKS_QCOUNT
);
918 gfs2_sbstats_inc(gl
, GFS2_LKS_QCOUNT
);
919 if (likely(insert_pt
== NULL
)) {
920 list_add_tail(&gh
->gh_list
, &gl
->gl_holders
);
921 if (unlikely(gh
->gh_flags
& LM_FLAG_PRIORITY
))
925 list_add_tail(&gh
->gh_list
, insert_pt
);
927 gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
, gh_list
);
928 if (!(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
929 spin_unlock(&gl
->gl_lockref
.lock
);
930 if (sdp
->sd_lockstruct
.ls_ops
->lm_cancel
)
931 sdp
->sd_lockstruct
.ls_ops
->lm_cancel(gl
);
932 spin_lock(&gl
->gl_lockref
.lock
);
937 pr_err("original: %pSR\n", (void *)gh2
->gh_ip
);
938 pr_err("pid: %d\n", pid_nr(gh2
->gh_owner_pid
));
939 pr_err("lock type: %d req lock state : %d\n",
940 gh2
->gh_gl
->gl_name
.ln_type
, gh2
->gh_state
);
941 pr_err("new: %pSR\n", (void *)gh
->gh_ip
);
942 pr_err("pid: %d\n", pid_nr(gh
->gh_owner_pid
));
943 pr_err("lock type: %d req lock state : %d\n",
944 gh
->gh_gl
->gl_name
.ln_type
, gh
->gh_state
);
945 gfs2_dump_glock(NULL
, gl
);
950 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
951 * @gh: the holder structure
953 * if (gh->gh_flags & GL_ASYNC), this never returns an error
955 * Returns: 0, GLR_TRYFAILED, or errno on failure
958 int gfs2_glock_nq(struct gfs2_holder
*gh
)
960 struct gfs2_glock
*gl
= gh
->gh_gl
;
961 struct gfs2_sbd
*sdp
= gl
->gl_name
.ln_sbd
;
964 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
967 if (test_bit(GLF_LRU
, &gl
->gl_flags
))
968 gfs2_glock_remove_from_lru(gl
);
970 spin_lock(&gl
->gl_lockref
.lock
);
972 if (unlikely((LM_FLAG_NOEXP
& gh
->gh_flags
) &&
973 test_and_clear_bit(GLF_FROZEN
, &gl
->gl_flags
))) {
974 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
975 gl
->gl_lockref
.count
++;
976 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
977 gl
->gl_lockref
.count
--;
980 spin_unlock(&gl
->gl_lockref
.lock
);
982 if (!(gh
->gh_flags
& GL_ASYNC
))
983 error
= gfs2_glock_wait(gh
);
989 * gfs2_glock_poll - poll to see if an async request has been completed
992 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
995 int gfs2_glock_poll(struct gfs2_holder
*gh
)
997 return test_bit(HIF_WAIT
, &gh
->gh_iflags
) ? 0 : 1;
1001 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1002 * @gh: the glock holder
1006 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1008 struct gfs2_glock
*gl
= gh
->gh_gl
;
1009 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1013 spin_lock(&gl
->gl_lockref
.lock
);
1014 if (gh
->gh_flags
& GL_NOCACHE
)
1015 handle_callback(gl
, LM_ST_UNLOCKED
, 0, false);
1017 list_del_init(&gh
->gh_list
);
1018 clear_bit(HIF_HOLDER
, &gh
->gh_iflags
);
1019 if (find_first_holder(gl
) == NULL
) {
1020 if (glops
->go_unlock
) {
1021 GLOCK_BUG_ON(gl
, test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
));
1022 spin_unlock(&gl
->gl_lockref
.lock
);
1023 glops
->go_unlock(gh
);
1024 spin_lock(&gl
->gl_lockref
.lock
);
1025 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1027 if (list_empty(&gl
->gl_holders
) &&
1028 !test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
1029 !test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1032 if (!test_bit(GLF_LFLUSH
, &gl
->gl_flags
) && demote_ok(gl
) &&
1033 (glops
->go_flags
& GLOF_LRU
))
1034 gfs2_glock_add_to_lru(gl
);
1036 trace_gfs2_glock_queue(gh
, 0);
1037 spin_unlock(&gl
->gl_lockref
.lock
);
1038 if (likely(fast_path
))
1041 gfs2_glock_hold(gl
);
1042 if (test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
1043 !test_bit(GLF_DEMOTE
, &gl
->gl_flags
) &&
1044 gl
->gl_name
.ln_type
== LM_TYPE_INODE
)
1045 delay
= gl
->gl_hold_time
;
1046 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
1050 void gfs2_glock_dq_wait(struct gfs2_holder
*gh
)
1052 struct gfs2_glock
*gl
= gh
->gh_gl
;
1055 wait_on_bit(&gl
->gl_flags
, GLF_DEMOTE
, TASK_UNINTERRUPTIBLE
);
1059 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1060 * @gh: the holder structure
1064 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1067 gfs2_holder_uninit(gh
);
1071 * gfs2_glock_nq_num - acquire a glock based on lock number
1072 * @sdp: the filesystem
1073 * @number: the lock number
1074 * @glops: the glock operations for the type of glock
1075 * @state: the state to acquire the glock in
1076 * @flags: modifier flags for the acquisition
1077 * @gh: the struct gfs2_holder
1082 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, u64 number
,
1083 const struct gfs2_glock_operations
*glops
,
1084 unsigned int state
, u16 flags
, struct gfs2_holder
*gh
)
1086 struct gfs2_glock
*gl
;
1089 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1091 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1099 * glock_compare - Compare two struct gfs2_glock structures for sorting
1100 * @arg_a: the first structure
1101 * @arg_b: the second structure
1105 static int glock_compare(const void *arg_a
, const void *arg_b
)
1107 const struct gfs2_holder
*gh_a
= *(const struct gfs2_holder
**)arg_a
;
1108 const struct gfs2_holder
*gh_b
= *(const struct gfs2_holder
**)arg_b
;
1109 const struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1110 const struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1112 if (a
->ln_number
> b
->ln_number
)
1114 if (a
->ln_number
< b
->ln_number
)
1116 BUG_ON(gh_a
->gh_gl
->gl_ops
->go_type
== gh_b
->gh_gl
->gl_ops
->go_type
);
1121 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1122 * @num_gh: the number of structures
1123 * @ghs: an array of struct gfs2_holder structures
1125 * Returns: 0 on success (all glocks acquired),
1126 * errno on failure (no glocks acquired)
1129 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1130 struct gfs2_holder
**p
)
1135 for (x
= 0; x
< num_gh
; x
++)
1138 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1140 for (x
= 0; x
< num_gh
; x
++) {
1141 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1143 error
= gfs2_glock_nq(p
[x
]);
1146 gfs2_glock_dq(p
[x
]);
1155 * gfs2_glock_nq_m - acquire multiple glocks
1156 * @num_gh: the number of structures
1157 * @ghs: an array of struct gfs2_holder structures
1160 * Returns: 0 on success (all glocks acquired),
1161 * errno on failure (no glocks acquired)
1164 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1166 struct gfs2_holder
*tmp
[4];
1167 struct gfs2_holder
**pph
= tmp
;
1174 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1175 return gfs2_glock_nq(ghs
);
1179 pph
= kmalloc(num_gh
* sizeof(struct gfs2_holder
*), GFP_NOFS
);
1184 error
= nq_m_sync(num_gh
, ghs
, pph
);
1193 * gfs2_glock_dq_m - release multiple glocks
1194 * @num_gh: the number of structures
1195 * @ghs: an array of struct gfs2_holder structures
1199 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1202 gfs2_glock_dq(&ghs
[num_gh
]);
1205 void gfs2_glock_cb(struct gfs2_glock
*gl
, unsigned int state
)
1207 unsigned long delay
= 0;
1208 unsigned long holdtime
;
1209 unsigned long now
= jiffies
;
1211 gfs2_glock_hold(gl
);
1212 holdtime
= gl
->gl_tchange
+ gl
->gl_hold_time
;
1213 if (test_bit(GLF_QUEUED
, &gl
->gl_flags
) &&
1214 gl
->gl_name
.ln_type
== LM_TYPE_INODE
) {
1215 if (time_before(now
, holdtime
))
1216 delay
= holdtime
- now
;
1217 if (test_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
))
1218 delay
= gl
->gl_hold_time
;
1221 spin_lock(&gl
->gl_lockref
.lock
);
1222 handle_callback(gl
, state
, delay
, true);
1223 spin_unlock(&gl
->gl_lockref
.lock
);
1224 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
1229 * gfs2_should_freeze - Figure out if glock should be frozen
1230 * @gl: The glock in question
1232 * Glocks are not frozen if (a) the result of the dlm operation is
1233 * an error, (b) the locking operation was an unlock operation or
1234 * (c) if there is a "noexp" flagged request anywhere in the queue
1236 * Returns: 1 if freezing should occur, 0 otherwise
1239 static int gfs2_should_freeze(const struct gfs2_glock
*gl
)
1241 const struct gfs2_holder
*gh
;
1243 if (gl
->gl_reply
& ~LM_OUT_ST_MASK
)
1245 if (gl
->gl_target
== LM_ST_UNLOCKED
)
1248 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1249 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
1251 if (LM_FLAG_NOEXP
& gh
->gh_flags
)
1259 * gfs2_glock_complete - Callback used by locking
1260 * @gl: Pointer to the glock
1261 * @ret: The return value from the dlm
1263 * The gl_reply field is under the gl_lockref.lock lock so that it is ok
1264 * to use a bitfield shared with other glock state fields.
1267 void gfs2_glock_complete(struct gfs2_glock
*gl
, int ret
)
1269 struct lm_lockstruct
*ls
= &gl
->gl_name
.ln_sbd
->sd_lockstruct
;
1271 spin_lock(&gl
->gl_lockref
.lock
);
1274 if (unlikely(test_bit(DFL_BLOCK_LOCKS
, &ls
->ls_recover_flags
))) {
1275 if (gfs2_should_freeze(gl
)) {
1276 set_bit(GLF_FROZEN
, &gl
->gl_flags
);
1277 spin_unlock(&gl
->gl_lockref
.lock
);
1282 gl
->gl_lockref
.count
++;
1283 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1284 spin_unlock(&gl
->gl_lockref
.lock
);
1286 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1290 static int glock_cmp(void *priv
, struct list_head
*a
, struct list_head
*b
)
1292 struct gfs2_glock
*gla
, *glb
;
1294 gla
= list_entry(a
, struct gfs2_glock
, gl_lru
);
1295 glb
= list_entry(b
, struct gfs2_glock
, gl_lru
);
1297 if (gla
->gl_name
.ln_number
> glb
->gl_name
.ln_number
)
1299 if (gla
->gl_name
.ln_number
< glb
->gl_name
.ln_number
)
1306 * gfs2_dispose_glock_lru - Demote a list of glocks
1307 * @list: The list to dispose of
1309 * Disposing of glocks may involve disk accesses, so that here we sort
1310 * the glocks by number (i.e. disk location of the inodes) so that if
1311 * there are any such accesses, they'll be sent in order (mostly).
1313 * Must be called under the lru_lock, but may drop and retake this
1314 * lock. While the lru_lock is dropped, entries may vanish from the
1315 * list, but no new entries will appear on the list (since it is
1319 static void gfs2_dispose_glock_lru(struct list_head
*list
)
1320 __releases(&lru_lock
)
1321 __acquires(&lru_lock
)
1323 struct gfs2_glock
*gl
;
1325 list_sort(NULL
, list
, glock_cmp
);
1327 while(!list_empty(list
)) {
1328 gl
= list_entry(list
->next
, struct gfs2_glock
, gl_lru
);
1329 list_del_init(&gl
->gl_lru
);
1330 if (!spin_trylock(&gl
->gl_lockref
.lock
)) {
1332 list_add(&gl
->gl_lru
, &lru_list
);
1333 atomic_inc(&lru_count
);
1336 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
1337 spin_unlock(&gl
->gl_lockref
.lock
);
1338 goto add_back_to_lru
;
1340 clear_bit(GLF_LRU
, &gl
->gl_flags
);
1341 gl
->gl_lockref
.count
++;
1343 handle_callback(gl
, LM_ST_UNLOCKED
, 0, false);
1344 WARN_ON(!test_and_clear_bit(GLF_LOCK
, &gl
->gl_flags
));
1345 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1346 gl
->gl_lockref
.count
--;
1347 spin_unlock(&gl
->gl_lockref
.lock
);
1348 cond_resched_lock(&lru_lock
);
1353 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1354 * @nr: The number of entries to scan
1356 * This function selects the entries on the LRU which are able to
1357 * be demoted, and then kicks off the process by calling
1358 * gfs2_dispose_glock_lru() above.
1361 static long gfs2_scan_glock_lru(int nr
)
1363 struct gfs2_glock
*gl
;
1368 spin_lock(&lru_lock
);
1369 while ((nr
-- >= 0) && !list_empty(&lru_list
)) {
1370 gl
= list_entry(lru_list
.next
, struct gfs2_glock
, gl_lru
);
1372 /* Test for being demotable */
1373 if (!test_bit(GLF_LOCK
, &gl
->gl_flags
)) {
1374 list_move(&gl
->gl_lru
, &dispose
);
1375 atomic_dec(&lru_count
);
1380 list_move(&gl
->gl_lru
, &skipped
);
1382 list_splice(&skipped
, &lru_list
);
1383 if (!list_empty(&dispose
))
1384 gfs2_dispose_glock_lru(&dispose
);
1385 spin_unlock(&lru_lock
);
1390 static unsigned long gfs2_glock_shrink_scan(struct shrinker
*shrink
,
1391 struct shrink_control
*sc
)
1393 if (!(sc
->gfp_mask
& __GFP_FS
))
1395 return gfs2_scan_glock_lru(sc
->nr_to_scan
);
1398 static unsigned long gfs2_glock_shrink_count(struct shrinker
*shrink
,
1399 struct shrink_control
*sc
)
1401 return vfs_pressure_ratio(atomic_read(&lru_count
));
1404 static struct shrinker glock_shrinker
= {
1405 .seeks
= DEFAULT_SEEKS
,
1406 .count_objects
= gfs2_glock_shrink_count
,
1407 .scan_objects
= gfs2_glock_shrink_scan
,
1411 * examine_bucket - Call a function for glock in a hash bucket
1412 * @examiner: the function
1413 * @sdp: the filesystem
1414 * @bucket: the bucket
1418 static void glock_hash_walk(glock_examiner examiner
, const struct gfs2_sbd
*sdp
)
1420 struct gfs2_glock
*gl
;
1421 struct rhash_head
*pos
;
1422 const struct bucket_table
*tbl
;
1426 tbl
= rht_dereference_rcu(gl_hash_table
.tbl
, &gl_hash_table
);
1427 for (i
= 0; i
< tbl
->size
; i
++) {
1428 rht_for_each_entry_rcu(gl
, pos
, tbl
, i
, gl_node
) {
1429 if ((gl
->gl_name
.ln_sbd
== sdp
) &&
1430 lockref_get_not_dead(&gl
->gl_lockref
))
1439 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1440 * @gl: The glock to thaw
1444 static void thaw_glock(struct gfs2_glock
*gl
)
1446 if (!test_and_clear_bit(GLF_FROZEN
, &gl
->gl_flags
))
1448 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1449 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0) {
1456 * clear_glock - look at a glock and see if we can free it from glock cache
1457 * @gl: the glock to look at
1461 static void clear_glock(struct gfs2_glock
*gl
)
1463 gfs2_glock_remove_from_lru(gl
);
1465 spin_lock(&gl
->gl_lockref
.lock
);
1466 if (gl
->gl_state
!= LM_ST_UNLOCKED
)
1467 handle_callback(gl
, LM_ST_UNLOCKED
, 0, false);
1468 spin_unlock(&gl
->gl_lockref
.lock
);
1469 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1474 * gfs2_glock_thaw - Thaw any frozen glocks
1475 * @sdp: The super block
1479 void gfs2_glock_thaw(struct gfs2_sbd
*sdp
)
1481 glock_hash_walk(thaw_glock
, sdp
);
1484 static void dump_glock(struct seq_file
*seq
, struct gfs2_glock
*gl
)
1486 spin_lock(&gl
->gl_lockref
.lock
);
1487 gfs2_dump_glock(seq
, gl
);
1488 spin_unlock(&gl
->gl_lockref
.lock
);
1491 static void dump_glock_func(struct gfs2_glock
*gl
)
1493 dump_glock(NULL
, gl
);
1497 * gfs2_gl_hash_clear - Empty out the glock hash table
1498 * @sdp: the filesystem
1499 * @wait: wait until it's all gone
1501 * Called when unmounting the filesystem.
1504 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
)
1506 set_bit(SDF_SKIP_DLM_UNLOCK
, &sdp
->sd_flags
);
1507 flush_workqueue(glock_workqueue
);
1508 glock_hash_walk(clear_glock
, sdp
);
1509 flush_workqueue(glock_workqueue
);
1510 wait_event_timeout(sdp
->sd_glock_wait
,
1511 atomic_read(&sdp
->sd_glock_disposal
) == 0,
1513 glock_hash_walk(dump_glock_func
, sdp
);
1516 void gfs2_glock_finish_truncate(struct gfs2_inode
*ip
)
1518 struct gfs2_glock
*gl
= ip
->i_gl
;
1521 ret
= gfs2_truncatei_resume(ip
);
1522 gfs2_assert_withdraw(gl
->gl_name
.ln_sbd
, ret
== 0);
1524 spin_lock(&gl
->gl_lockref
.lock
);
1525 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1527 spin_unlock(&gl
->gl_lockref
.lock
);
1530 static const char *state2str(unsigned state
)
1533 case LM_ST_UNLOCKED
:
1537 case LM_ST_DEFERRED
:
1539 case LM_ST_EXCLUSIVE
:
1545 static const char *hflags2str(char *buf
, u16 flags
, unsigned long iflags
)
1548 if (flags
& LM_FLAG_TRY
)
1550 if (flags
& LM_FLAG_TRY_1CB
)
1552 if (flags
& LM_FLAG_NOEXP
)
1554 if (flags
& LM_FLAG_ANY
)
1556 if (flags
& LM_FLAG_PRIORITY
)
1558 if (flags
& GL_ASYNC
)
1560 if (flags
& GL_EXACT
)
1562 if (flags
& GL_NOCACHE
)
1564 if (test_bit(HIF_HOLDER
, &iflags
))
1566 if (test_bit(HIF_WAIT
, &iflags
))
1568 if (test_bit(HIF_FIRST
, &iflags
))
1575 * dump_holder - print information about a glock holder
1576 * @seq: the seq_file struct
1577 * @gh: the glock holder
1581 static void dump_holder(struct seq_file
*seq
, const struct gfs2_holder
*gh
)
1583 struct task_struct
*gh_owner
= NULL
;
1587 if (gh
->gh_owner_pid
)
1588 gh_owner
= pid_task(gh
->gh_owner_pid
, PIDTYPE_PID
);
1589 gfs2_print_dbg(seq
, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1590 state2str(gh
->gh_state
),
1591 hflags2str(flags_buf
, gh
->gh_flags
, gh
->gh_iflags
),
1593 gh
->gh_owner_pid
? (long)pid_nr(gh
->gh_owner_pid
) : -1,
1594 gh_owner
? gh_owner
->comm
: "(ended)",
1599 static const char *gflags2str(char *buf
, const struct gfs2_glock
*gl
)
1601 const unsigned long *gflags
= &gl
->gl_flags
;
1604 if (test_bit(GLF_LOCK
, gflags
))
1606 if (test_bit(GLF_DEMOTE
, gflags
))
1608 if (test_bit(GLF_PENDING_DEMOTE
, gflags
))
1610 if (test_bit(GLF_DEMOTE_IN_PROGRESS
, gflags
))
1612 if (test_bit(GLF_DIRTY
, gflags
))
1614 if (test_bit(GLF_LFLUSH
, gflags
))
1616 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, gflags
))
1618 if (test_bit(GLF_REPLY_PENDING
, gflags
))
1620 if (test_bit(GLF_INITIAL
, gflags
))
1622 if (test_bit(GLF_FROZEN
, gflags
))
1624 if (test_bit(GLF_QUEUED
, gflags
))
1626 if (test_bit(GLF_LRU
, gflags
))
1630 if (test_bit(GLF_BLOCKING
, gflags
))
1637 * gfs2_dump_glock - print information about a glock
1638 * @seq: The seq_file struct
1641 * The file format is as follows:
1642 * One line per object, capital letters are used to indicate objects
1643 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1644 * other objects are indented by a single space and follow the glock to
1645 * which they are related. Fields are indicated by lower case letters
1646 * followed by a colon and the field value, except for strings which are in
1647 * [] so that its possible to see if they are composed of spaces for
1648 * example. The field's are n = number (id of the object), f = flags,
1649 * t = type, s = state, r = refcount, e = error, p = pid.
1653 void gfs2_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];
1660 dtime
= jiffies
- gl
->gl_demote_time
;
1661 dtime
*= 1000000/HZ
; /* demote time in uSec */
1662 if (!test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1664 gfs2_print_dbg(seq
, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d m:%ld\n",
1665 state2str(gl
->gl_state
),
1666 gl
->gl_name
.ln_type
,
1667 (unsigned long long)gl
->gl_name
.ln_number
,
1668 gflags2str(gflags_buf
, gl
),
1669 state2str(gl
->gl_target
),
1670 state2str(gl
->gl_demote_state
), dtime
,
1671 atomic_read(&gl
->gl_ail_count
),
1672 atomic_read(&gl
->gl_revokes
),
1673 (int)gl
->gl_lockref
.count
, gl
->gl_hold_time
);
1675 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
)
1676 dump_holder(seq
, gh
);
1678 if (gl
->gl_state
!= LM_ST_UNLOCKED
&& glops
->go_dump
)
1679 glops
->go_dump(seq
, gl
);
1682 static int gfs2_glstats_seq_show(struct seq_file
*seq
, void *iter_ptr
)
1684 struct gfs2_glock
*gl
= iter_ptr
;
1686 seq_printf(seq
, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
1687 gl
->gl_name
.ln_type
,
1688 (unsigned long long)gl
->gl_name
.ln_number
,
1689 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_SRTT
],
1690 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_SRTTVAR
],
1691 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_SRTTB
],
1692 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_SRTTVARB
],
1693 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_SIRT
],
1694 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_SIRTVAR
],
1695 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_DCOUNT
],
1696 (unsigned long long)gl
->gl_stats
.stats
[GFS2_LKS_QCOUNT
]);
1700 static const char *gfs2_gltype
[] = {
1714 static const char *gfs2_stype
[] = {
1715 [GFS2_LKS_SRTT
] = "srtt",
1716 [GFS2_LKS_SRTTVAR
] = "srttvar",
1717 [GFS2_LKS_SRTTB
] = "srttb",
1718 [GFS2_LKS_SRTTVARB
] = "srttvarb",
1719 [GFS2_LKS_SIRT
] = "sirt",
1720 [GFS2_LKS_SIRTVAR
] = "sirtvar",
1721 [GFS2_LKS_DCOUNT
] = "dlm",
1722 [GFS2_LKS_QCOUNT
] = "queue",
1725 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1727 static int gfs2_sbstats_seq_show(struct seq_file
*seq
, void *iter_ptr
)
1729 struct gfs2_sbd
*sdp
= seq
->private;
1730 loff_t pos
= *(loff_t
*)iter_ptr
;
1731 unsigned index
= pos
>> 3;
1732 unsigned subindex
= pos
& 0x07;
1735 if (index
== 0 && subindex
!= 0)
1738 seq_printf(seq
, "%-10s %8s:", gfs2_gltype
[index
],
1739 (index
== 0) ? "cpu": gfs2_stype
[subindex
]);
1741 for_each_possible_cpu(i
) {
1742 const struct gfs2_pcpu_lkstats
*lkstats
= per_cpu_ptr(sdp
->sd_lkstats
, i
);
1745 seq_printf(seq
, " %15u", i
);
1747 seq_printf(seq
, " %15llu", (unsigned long long)lkstats
->
1748 lkstats
[index
- 1].stats
[subindex
]);
1750 seq_putc(seq
, '\n');
1754 int __init
gfs2_glock_init(void)
1758 ret
= rhashtable_init(&gl_hash_table
, &ht_parms
);
1762 glock_workqueue
= alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM
|
1763 WQ_HIGHPRI
| WQ_FREEZABLE
, 0);
1764 if (!glock_workqueue
) {
1765 rhashtable_destroy(&gl_hash_table
);
1768 gfs2_delete_workqueue
= alloc_workqueue("delete_workqueue",
1769 WQ_MEM_RECLAIM
| WQ_FREEZABLE
,
1771 if (!gfs2_delete_workqueue
) {
1772 destroy_workqueue(glock_workqueue
);
1773 rhashtable_destroy(&gl_hash_table
);
1777 register_shrinker(&glock_shrinker
);
1782 void gfs2_glock_exit(void)
1784 unregister_shrinker(&glock_shrinker
);
1785 rhashtable_destroy(&gl_hash_table
);
1786 destroy_workqueue(glock_workqueue
);
1787 destroy_workqueue(gfs2_delete_workqueue
);
1790 static void gfs2_glock_iter_next(struct gfs2_glock_iter
*gi
)
1793 gi
->gl
= rhashtable_walk_next(&gi
->hti
);
1794 if (IS_ERR(gi
->gl
)) {
1795 if (PTR_ERR(gi
->gl
) == -EAGAIN
)
1799 /* Skip entries for other sb and dead entries */
1800 } while ((gi
->gl
) && ((gi
->sdp
!= gi
->gl
->gl_name
.ln_sbd
) ||
1801 __lockref_is_dead(&gi
->gl
->gl_lockref
)));
1804 static void *gfs2_glock_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1806 struct gfs2_glock_iter
*gi
= seq
->private;
1810 if (gi
->last_pos
<= *pos
)
1811 n
= (*pos
- gi
->last_pos
);
1813 ret
= rhashtable_walk_start(&gi
->hti
);
1818 gfs2_glock_iter_next(gi
);
1819 } while (gi
->gl
&& n
--);
1821 gi
->last_pos
= *pos
;
1825 static void *gfs2_glock_seq_next(struct seq_file
*seq
, void *iter_ptr
,
1828 struct gfs2_glock_iter
*gi
= seq
->private;
1831 gi
->last_pos
= *pos
;
1832 gfs2_glock_iter_next(gi
);
1836 static void gfs2_glock_seq_stop(struct seq_file
*seq
, void *iter_ptr
)
1838 struct gfs2_glock_iter
*gi
= seq
->private;
1841 rhashtable_walk_stop(&gi
->hti
);
1844 static int gfs2_glock_seq_show(struct seq_file
*seq
, void *iter_ptr
)
1846 dump_glock(seq
, iter_ptr
);
1850 static void *gfs2_sbstats_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1853 if (*pos
>= GFS2_NR_SBSTATS
)
1858 static void *gfs2_sbstats_seq_next(struct seq_file
*seq
, void *iter_ptr
,
1862 if (*pos
>= GFS2_NR_SBSTATS
)
1867 static void gfs2_sbstats_seq_stop(struct seq_file
*seq
, void *iter_ptr
)
1872 static const struct seq_operations gfs2_glock_seq_ops
= {
1873 .start
= gfs2_glock_seq_start
,
1874 .next
= gfs2_glock_seq_next
,
1875 .stop
= gfs2_glock_seq_stop
,
1876 .show
= gfs2_glock_seq_show
,
1879 static const struct seq_operations gfs2_glstats_seq_ops
= {
1880 .start
= gfs2_glock_seq_start
,
1881 .next
= gfs2_glock_seq_next
,
1882 .stop
= gfs2_glock_seq_stop
,
1883 .show
= gfs2_glstats_seq_show
,
1886 static const struct seq_operations gfs2_sbstats_seq_ops
= {
1887 .start
= gfs2_sbstats_seq_start
,
1888 .next
= gfs2_sbstats_seq_next
,
1889 .stop
= gfs2_sbstats_seq_stop
,
1890 .show
= gfs2_sbstats_seq_show
,
1893 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
1895 static int gfs2_glocks_open(struct inode
*inode
, struct file
*file
)
1897 int ret
= seq_open_private(file
, &gfs2_glock_seq_ops
,
1898 sizeof(struct gfs2_glock_iter
));
1900 struct seq_file
*seq
= file
->private_data
;
1901 struct gfs2_glock_iter
*gi
= seq
->private;
1903 gi
->sdp
= inode
->i_private
;
1905 seq
->buf
= kmalloc(GFS2_SEQ_GOODSIZE
, GFP_KERNEL
| __GFP_NOWARN
);
1907 seq
->size
= GFS2_SEQ_GOODSIZE
;
1909 ret
= rhashtable_walk_init(&gl_hash_table
, &gi
->hti
);
1914 static int gfs2_glocks_release(struct inode
*inode
, struct file
*file
)
1916 struct seq_file
*seq
= file
->private_data
;
1917 struct gfs2_glock_iter
*gi
= seq
->private;
1920 rhashtable_walk_exit(&gi
->hti
);
1921 return seq_release_private(inode
, file
);
1924 static int gfs2_glstats_open(struct inode
*inode
, struct file
*file
)
1926 int ret
= seq_open_private(file
, &gfs2_glstats_seq_ops
,
1927 sizeof(struct gfs2_glock_iter
));
1929 struct seq_file
*seq
= file
->private_data
;
1930 struct gfs2_glock_iter
*gi
= seq
->private;
1931 gi
->sdp
= inode
->i_private
;
1933 seq
->buf
= kmalloc(GFS2_SEQ_GOODSIZE
, GFP_KERNEL
| __GFP_NOWARN
);
1935 seq
->size
= GFS2_SEQ_GOODSIZE
;
1937 ret
= rhashtable_walk_init(&gl_hash_table
, &gi
->hti
);
1942 static int gfs2_sbstats_open(struct inode
*inode
, struct file
*file
)
1944 int ret
= seq_open(file
, &gfs2_sbstats_seq_ops
);
1946 struct seq_file
*seq
= file
->private_data
;
1947 seq
->private = inode
->i_private
; /* sdp */
1952 static const struct file_operations gfs2_glocks_fops
= {
1953 .owner
= THIS_MODULE
,
1954 .open
= gfs2_glocks_open
,
1956 .llseek
= seq_lseek
,
1957 .release
= gfs2_glocks_release
,
1960 static const struct file_operations gfs2_glstats_fops
= {
1961 .owner
= THIS_MODULE
,
1962 .open
= gfs2_glstats_open
,
1964 .llseek
= seq_lseek
,
1965 .release
= gfs2_glocks_release
,
1968 static const struct file_operations gfs2_sbstats_fops
= {
1969 .owner
= THIS_MODULE
,
1970 .open
= gfs2_sbstats_open
,
1972 .llseek
= seq_lseek
,
1973 .release
= seq_release
,
1976 int gfs2_create_debugfs_file(struct gfs2_sbd
*sdp
)
1978 struct dentry
*dent
;
1980 dent
= debugfs_create_dir(sdp
->sd_table_name
, gfs2_root
);
1981 if (IS_ERR_OR_NULL(dent
))
1983 sdp
->debugfs_dir
= dent
;
1985 dent
= debugfs_create_file("glocks",
1987 sdp
->debugfs_dir
, sdp
,
1989 if (IS_ERR_OR_NULL(dent
))
1991 sdp
->debugfs_dentry_glocks
= dent
;
1993 dent
= debugfs_create_file("glstats",
1995 sdp
->debugfs_dir
, sdp
,
1996 &gfs2_glstats_fops
);
1997 if (IS_ERR_OR_NULL(dent
))
1999 sdp
->debugfs_dentry_glstats
= dent
;
2001 dent
= debugfs_create_file("sbstats",
2003 sdp
->debugfs_dir
, sdp
,
2004 &gfs2_sbstats_fops
);
2005 if (IS_ERR_OR_NULL(dent
))
2007 sdp
->debugfs_dentry_sbstats
= dent
;
2011 gfs2_delete_debugfs_file(sdp
);
2012 return dent
? PTR_ERR(dent
) : -ENOMEM
;
2015 void gfs2_delete_debugfs_file(struct gfs2_sbd
*sdp
)
2017 if (sdp
->debugfs_dir
) {
2018 if (sdp
->debugfs_dentry_glocks
) {
2019 debugfs_remove(sdp
->debugfs_dentry_glocks
);
2020 sdp
->debugfs_dentry_glocks
= NULL
;
2022 if (sdp
->debugfs_dentry_glstats
) {
2023 debugfs_remove(sdp
->debugfs_dentry_glstats
);
2024 sdp
->debugfs_dentry_glstats
= NULL
;
2026 if (sdp
->debugfs_dentry_sbstats
) {
2027 debugfs_remove(sdp
->debugfs_dentry_sbstats
);
2028 sdp
->debugfs_dentry_sbstats
= NULL
;
2030 debugfs_remove(sdp
->debugfs_dir
);
2031 sdp
->debugfs_dir
= NULL
;
2035 int gfs2_register_debugfs(void)
2037 gfs2_root
= debugfs_create_dir("gfs2", NULL
);
2038 if (IS_ERR(gfs2_root
))
2039 return PTR_ERR(gfs2_root
);
2040 return gfs2_root
? 0 : -ENOMEM
;
2043 void gfs2_unregister_debugfs(void)
2045 debugfs_remove(gfs2_root
);