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 <linux/rwsem.h>
23 #include <asm/uaccess.h>
24 #include <linux/seq_file.h>
25 #include <linux/debugfs.h>
26 #include <linux/kthread.h>
27 #include <linux/freezer.h>
28 #include <linux/workqueue.h>
29 #include <linux/jiffies.h>
42 #define CREATE_TRACE_POINTS
43 #include "trace_gfs2.h"
45 struct gfs2_gl_hash_bucket
{
46 struct hlist_head hb_list
;
49 struct gfs2_glock_iter
{
50 int hash
; /* hash bucket index */
51 struct gfs2_sbd
*sdp
; /* incore superblock */
52 struct gfs2_glock
*gl
; /* current glock struct */
53 char string
[512]; /* scratch space */
56 typedef void (*glock_examiner
) (struct gfs2_glock
* gl
);
58 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
);
59 static int __dump_glock(struct seq_file
*seq
, const struct gfs2_glock
*gl
);
60 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
61 static void do_xmote(struct gfs2_glock
*gl
, struct gfs2_holder
*gh
, unsigned int target
);
63 static DECLARE_RWSEM(gfs2_umount_flush_sem
);
64 static struct dentry
*gfs2_root
;
65 static struct workqueue_struct
*glock_workqueue
;
66 static LIST_HEAD(lru_list
);
67 static atomic_t lru_count
= ATOMIC_INIT(0);
68 static DEFINE_SPINLOCK(lru_lock
);
70 #define GFS2_GL_HASH_SHIFT 15
71 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
72 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
74 static struct gfs2_gl_hash_bucket gl_hash_table
[GFS2_GL_HASH_SIZE
];
75 static struct dentry
*gfs2_root
;
78 * Despite what you might think, the numbers below are not arbitrary :-)
79 * They are taken from the ipv4 routing hash code, which is well tested
80 * and thus should be nearly optimal. Later on we might tweek the numbers
81 * but for now this should be fine.
83 * The reason for putting the locks in a separate array from the list heads
84 * is that we can have fewer locks than list heads and save memory. We use
85 * the same hash function for both, but with a different hash mask.
87 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
88 defined(CONFIG_PROVE_LOCKING)
91 # define GL_HASH_LOCK_SZ 256
94 # define GL_HASH_LOCK_SZ 4096
96 # define GL_HASH_LOCK_SZ 2048
98 # define GL_HASH_LOCK_SZ 1024
100 # define GL_HASH_LOCK_SZ 512
102 # define GL_HASH_LOCK_SZ 256
106 /* We never want more locks than chains */
107 #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
108 # undef GL_HASH_LOCK_SZ
109 # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
112 static rwlock_t gl_hash_locks
[GL_HASH_LOCK_SZ
];
114 static inline rwlock_t
*gl_lock_addr(unsigned int x
)
116 return &gl_hash_locks
[x
& (GL_HASH_LOCK_SZ
-1)];
118 #else /* not SMP, so no spinlocks required */
119 static inline rwlock_t
*gl_lock_addr(unsigned int x
)
126 * gl_hash() - Turn glock number into hash bucket number
127 * @lock: The glock number
129 * Returns: The number of the corresponding hash bucket
132 static unsigned int gl_hash(const struct gfs2_sbd
*sdp
,
133 const struct lm_lockname
*name
)
137 h
= jhash(&name
->ln_number
, sizeof(u64
), 0);
138 h
= jhash(&name
->ln_type
, sizeof(unsigned int), h
);
139 h
= jhash(&sdp
, sizeof(struct gfs2_sbd
*), h
);
140 h
&= GFS2_GL_HASH_MASK
;
146 * glock_free() - Perform a few checks and then release struct gfs2_glock
147 * @gl: The glock to release
149 * Also calls lock module to release its internal structure for this glock.
153 static void glock_free(struct gfs2_glock
*gl
)
155 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
156 struct inode
*aspace
= gl
->gl_aspace
;
159 gfs2_aspace_put(aspace
);
160 trace_gfs2_glock_put(gl
);
161 sdp
->sd_lockstruct
.ls_ops
->lm_put_lock(gfs2_glock_cachep
, gl
);
165 * gfs2_glock_hold() - increment reference count on glock
166 * @gl: The glock to hold
170 static void gfs2_glock_hold(struct gfs2_glock
*gl
)
172 GLOCK_BUG_ON(gl
, atomic_read(&gl
->gl_ref
) == 0);
173 atomic_inc(&gl
->gl_ref
);
177 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
182 static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock
*gl
)
184 spin_lock(&lru_lock
);
185 if (list_empty(&gl
->gl_lru
) && gl
->gl_state
!= LM_ST_UNLOCKED
) {
186 list_add_tail(&gl
->gl_lru
, &lru_list
);
187 atomic_inc(&lru_count
);
189 spin_unlock(&lru_lock
);
193 * gfs2_glock_put() - Decrement reference count on glock
194 * @gl: The glock to put
198 int gfs2_glock_put(struct gfs2_glock
*gl
)
202 write_lock(gl_lock_addr(gl
->gl_hash
));
203 if (atomic_dec_and_test(&gl
->gl_ref
)) {
204 hlist_del(&gl
->gl_list
);
205 write_unlock(gl_lock_addr(gl
->gl_hash
));
206 spin_lock(&lru_lock
);
207 if (!list_empty(&gl
->gl_lru
)) {
208 list_del_init(&gl
->gl_lru
);
209 atomic_dec(&lru_count
);
211 spin_unlock(&lru_lock
);
212 GLOCK_BUG_ON(gl
, !list_empty(&gl
->gl_holders
));
217 /* 1 for being hashed, 1 for having state != LM_ST_UNLOCKED */
218 if (atomic_read(&gl
->gl_ref
) == 2)
219 gfs2_glock_schedule_for_reclaim(gl
);
220 write_unlock(gl_lock_addr(gl
->gl_hash
));
226 * search_bucket() - Find struct gfs2_glock by lock number
227 * @bucket: the bucket to search
228 * @name: The lock name
230 * Returns: NULL, or the struct gfs2_glock with the requested number
233 static struct gfs2_glock
*search_bucket(unsigned int hash
,
234 const struct gfs2_sbd
*sdp
,
235 const struct lm_lockname
*name
)
237 struct gfs2_glock
*gl
;
238 struct hlist_node
*h
;
240 hlist_for_each_entry(gl
, h
, &gl_hash_table
[hash
].hb_list
, gl_list
) {
241 if (!lm_name_equal(&gl
->gl_name
, name
))
243 if (gl
->gl_sbd
!= sdp
)
246 atomic_inc(&gl
->gl_ref
);
255 * may_grant - check if its ok to grant a new lock
257 * @gh: The lock request which we wish to grant
259 * Returns: true if its ok to grant the lock
262 static inline int may_grant(const struct gfs2_glock
*gl
, const struct gfs2_holder
*gh
)
264 const struct gfs2_holder
*gh_head
= list_entry(gl
->gl_holders
.next
, const struct gfs2_holder
, gh_list
);
265 if ((gh
->gh_state
== LM_ST_EXCLUSIVE
||
266 gh_head
->gh_state
== LM_ST_EXCLUSIVE
) && gh
!= gh_head
)
268 if (gl
->gl_state
== gh
->gh_state
)
270 if (gh
->gh_flags
& GL_EXACT
)
272 if (gl
->gl_state
== LM_ST_EXCLUSIVE
) {
273 if (gh
->gh_state
== LM_ST_SHARED
&& gh_head
->gh_state
== LM_ST_SHARED
)
275 if (gh
->gh_state
== LM_ST_DEFERRED
&& gh_head
->gh_state
== LM_ST_DEFERRED
)
278 if (gl
->gl_state
!= LM_ST_UNLOCKED
&& (gh
->gh_flags
& LM_FLAG_ANY
))
283 static void gfs2_holder_wake(struct gfs2_holder
*gh
)
285 clear_bit(HIF_WAIT
, &gh
->gh_iflags
);
286 smp_mb__after_clear_bit();
287 wake_up_bit(&gh
->gh_iflags
, HIF_WAIT
);
291 * do_promote - promote as many requests as possible on the current queue
294 * Returns: 1 if there is a blocked holder at the head of the list, or 2
295 * if a type specific operation is underway.
298 static int do_promote(struct gfs2_glock
*gl
)
299 __releases(&gl
->gl_spin
)
300 __acquires(&gl
->gl_spin
)
302 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
303 struct gfs2_holder
*gh
, *tmp
;
307 list_for_each_entry_safe(gh
, tmp
, &gl
->gl_holders
, gh_list
) {
308 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
310 if (may_grant(gl
, gh
)) {
311 if (gh
->gh_list
.prev
== &gl
->gl_holders
&&
313 spin_unlock(&gl
->gl_spin
);
314 /* FIXME: eliminate this eventually */
315 ret
= glops
->go_lock(gh
);
316 spin_lock(&gl
->gl_spin
);
321 list_del_init(&gh
->gh_list
);
322 trace_gfs2_glock_queue(gh
, 0);
323 gfs2_holder_wake(gh
);
326 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
327 trace_gfs2_promote(gh
, 1);
328 gfs2_holder_wake(gh
);
331 set_bit(HIF_HOLDER
, &gh
->gh_iflags
);
332 trace_gfs2_promote(gh
, 0);
333 gfs2_holder_wake(gh
);
336 if (gh
->gh_list
.prev
== &gl
->gl_holders
)
344 * do_error - Something unexpected has happened during a lock request
348 static inline void do_error(struct gfs2_glock
*gl
, const int ret
)
350 struct gfs2_holder
*gh
, *tmp
;
352 list_for_each_entry_safe(gh
, tmp
, &gl
->gl_holders
, gh_list
) {
353 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
355 if (ret
& LM_OUT_ERROR
)
357 else if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))
358 gh
->gh_error
= GLR_TRYFAILED
;
361 list_del_init(&gh
->gh_list
);
362 trace_gfs2_glock_queue(gh
, 0);
363 gfs2_holder_wake(gh
);
368 * find_first_waiter - find the first gh that's waiting for the glock
372 static inline struct gfs2_holder
*find_first_waiter(const struct gfs2_glock
*gl
)
374 struct gfs2_holder
*gh
;
376 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
377 if (!test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
384 * state_change - record that the glock is now in a different state
386 * @new_state the new state
390 static void state_change(struct gfs2_glock
*gl
, unsigned int new_state
)
394 held1
= (gl
->gl_state
!= LM_ST_UNLOCKED
);
395 held2
= (new_state
!= LM_ST_UNLOCKED
);
397 if (held1
!= held2
) {
404 gl
->gl_state
= new_state
;
405 gl
->gl_tchange
= jiffies
;
408 static void gfs2_demote_wake(struct gfs2_glock
*gl
)
410 gl
->gl_demote_state
= LM_ST_EXCLUSIVE
;
411 clear_bit(GLF_DEMOTE
, &gl
->gl_flags
);
412 smp_mb__after_clear_bit();
413 wake_up_bit(&gl
->gl_flags
, GLF_DEMOTE
);
417 * finish_xmote - The DLM has replied to one of our lock requests
419 * @ret: The status from the DLM
423 static void finish_xmote(struct gfs2_glock
*gl
, unsigned int ret
)
425 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
426 struct gfs2_holder
*gh
;
427 unsigned state
= ret
& LM_OUT_ST_MASK
;
430 spin_lock(&gl
->gl_spin
);
431 trace_gfs2_glock_state_change(gl
, state
);
432 state_change(gl
, state
);
433 gh
= find_first_waiter(gl
);
435 /* Demote to UN request arrived during demote to SH or DF */
436 if (test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
) &&
437 state
!= LM_ST_UNLOCKED
&& gl
->gl_demote_state
== LM_ST_UNLOCKED
)
438 gl
->gl_target
= LM_ST_UNLOCKED
;
440 /* Check for state != intended state */
441 if (unlikely(state
!= gl
->gl_target
)) {
442 if (gh
&& !test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
)) {
443 /* move to back of queue and try next entry */
444 if (ret
& LM_OUT_CANCELED
) {
445 if ((gh
->gh_flags
& LM_FLAG_PRIORITY
) == 0)
446 list_move_tail(&gh
->gh_list
, &gl
->gl_holders
);
447 gh
= find_first_waiter(gl
);
448 gl
->gl_target
= gh
->gh_state
;
451 /* Some error or failed "try lock" - report it */
452 if ((ret
& LM_OUT_ERROR
) ||
453 (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
))) {
454 gl
->gl_target
= gl
->gl_state
;
460 /* Unlocked due to conversion deadlock, try again */
463 do_xmote(gl
, gh
, gl
->gl_target
);
465 /* Conversion fails, unlock and try again */
468 do_xmote(gl
, gh
, LM_ST_UNLOCKED
);
470 default: /* Everything else */
471 printk(KERN_ERR
"GFS2: wanted %u got %u\n", gl
->gl_target
, state
);
474 spin_unlock(&gl
->gl_spin
);
479 /* Fast path - we got what we asked for */
480 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
))
481 gfs2_demote_wake(gl
);
482 if (state
!= LM_ST_UNLOCKED
) {
483 if (glops
->go_xmote_bh
) {
484 spin_unlock(&gl
->gl_spin
);
485 rv
= glops
->go_xmote_bh(gl
, gh
);
488 spin_lock(&gl
->gl_spin
);
499 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
501 spin_unlock(&gl
->gl_spin
);
505 static unsigned int gfs2_lm_lock(struct gfs2_sbd
*sdp
, void *lock
,
506 unsigned int req_state
,
509 int ret
= LM_OUT_ERROR
;
511 if (!sdp
->sd_lockstruct
.ls_ops
->lm_lock
)
512 return req_state
== LM_ST_UNLOCKED
? 0 : req_state
;
514 if (likely(!test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
515 ret
= sdp
->sd_lockstruct
.ls_ops
->lm_lock(lock
,
521 * do_xmote - Calls the DLM to change the state of a lock
522 * @gl: The lock state
523 * @gh: The holder (only for promotes)
524 * @target: The target lock state
528 static void do_xmote(struct gfs2_glock
*gl
, struct gfs2_holder
*gh
, unsigned int target
)
529 __releases(&gl
->gl_spin
)
530 __acquires(&gl
->gl_spin
)
532 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
533 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
534 unsigned int lck_flags
= gh
? gh
->gh_flags
: 0;
537 lck_flags
&= (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
| LM_FLAG_NOEXP
|
539 BUG_ON(gl
->gl_state
== target
);
540 BUG_ON(gl
->gl_state
== gl
->gl_target
);
541 if ((target
== LM_ST_UNLOCKED
|| target
== LM_ST_DEFERRED
) &&
543 set_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
);
544 do_error(gl
, 0); /* Fail queued try locks */
546 spin_unlock(&gl
->gl_spin
);
547 if (glops
->go_xmote_th
)
548 glops
->go_xmote_th(gl
);
549 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
))
550 glops
->go_inval(gl
, target
== LM_ST_DEFERRED
? 0 : DIO_METADATA
);
551 clear_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
);
554 if (target
!= LM_ST_UNLOCKED
&& (gl
->gl_state
== LM_ST_SHARED
||
555 gl
->gl_state
== LM_ST_DEFERRED
) &&
556 !(lck_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)))
557 lck_flags
|= LM_FLAG_TRY_1CB
;
558 ret
= gfs2_lm_lock(sdp
, gl
, target
, lck_flags
);
560 if (!(ret
& LM_OUT_ASYNC
)) {
561 finish_xmote(gl
, ret
);
563 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
566 GLOCK_BUG_ON(gl
, ret
!= LM_OUT_ASYNC
);
568 spin_lock(&gl
->gl_spin
);
572 * find_first_holder - find the first "holder" gh
576 static inline struct gfs2_holder
*find_first_holder(const struct gfs2_glock
*gl
)
578 struct gfs2_holder
*gh
;
580 if (!list_empty(&gl
->gl_holders
)) {
581 gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
, gh_list
);
582 if (test_bit(HIF_HOLDER
, &gh
->gh_iflags
))
589 * run_queue - do all outstanding tasks related to a glock
590 * @gl: The glock in question
591 * @nonblock: True if we must not block in run_queue
595 static void run_queue(struct gfs2_glock
*gl
, const int nonblock
)
596 __releases(&gl
->gl_spin
)
597 __acquires(&gl
->gl_spin
)
599 struct gfs2_holder
*gh
= NULL
;
602 if (test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
))
605 GLOCK_BUG_ON(gl
, test_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
));
607 if (test_bit(GLF_DEMOTE
, &gl
->gl_flags
) &&
608 gl
->gl_demote_state
!= gl
->gl_state
) {
609 if (find_first_holder(gl
))
613 set_bit(GLF_DEMOTE_IN_PROGRESS
, &gl
->gl_flags
);
614 GLOCK_BUG_ON(gl
, gl
->gl_demote_state
== LM_ST_EXCLUSIVE
);
615 gl
->gl_target
= gl
->gl_demote_state
;
617 if (test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
618 gfs2_demote_wake(gl
);
619 ret
= do_promote(gl
);
624 gh
= find_first_waiter(gl
);
625 gl
->gl_target
= gh
->gh_state
;
626 if (!(gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)))
627 do_error(gl
, 0); /* Fail queued try locks */
629 do_xmote(gl
, gh
, gl
->gl_target
);
635 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
638 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
642 static void glock_work_func(struct work_struct
*work
)
644 unsigned long delay
= 0;
645 struct gfs2_glock
*gl
= container_of(work
, struct gfs2_glock
, gl_work
.work
);
647 if (test_and_clear_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
))
648 finish_xmote(gl
, gl
->gl_reply
);
649 down_read(&gfs2_umount_flush_sem
);
650 spin_lock(&gl
->gl_spin
);
651 if (test_and_clear_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
652 gl
->gl_state
!= LM_ST_UNLOCKED
&&
653 gl
->gl_demote_state
!= LM_ST_EXCLUSIVE
) {
654 unsigned long holdtime
, now
= jiffies
;
655 holdtime
= gl
->gl_tchange
+ gl
->gl_ops
->go_min_hold_time
;
656 if (time_before(now
, holdtime
))
657 delay
= holdtime
- now
;
658 set_bit(delay
? GLF_PENDING_DEMOTE
: GLF_DEMOTE
, &gl
->gl_flags
);
661 spin_unlock(&gl
->gl_spin
);
662 up_read(&gfs2_umount_flush_sem
);
664 queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
669 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
670 * @sdp: The GFS2 superblock
671 * @number: the lock number
672 * @glops: The glock_operations to use
673 * @create: If 0, don't create the glock if it doesn't exist
674 * @glp: the glock is returned here
676 * This does not lock a glock, just finds/creates structures for one.
681 int gfs2_glock_get(struct gfs2_sbd
*sdp
, u64 number
,
682 const struct gfs2_glock_operations
*glops
, int create
,
683 struct gfs2_glock
**glp
)
685 struct lm_lockname name
= { .ln_number
= number
, .ln_type
= glops
->go_type
};
686 struct gfs2_glock
*gl
, *tmp
;
687 unsigned int hash
= gl_hash(sdp
, &name
);
690 read_lock(gl_lock_addr(hash
));
691 gl
= search_bucket(hash
, sdp
, &name
);
692 read_unlock(gl_lock_addr(hash
));
700 gl
= kmem_cache_alloc(gfs2_glock_cachep
, GFP_KERNEL
);
706 atomic_set(&gl
->gl_ref
, 1);
707 gl
->gl_state
= LM_ST_UNLOCKED
;
708 gl
->gl_target
= LM_ST_UNLOCKED
;
709 gl
->gl_demote_state
= LM_ST_EXCLUSIVE
;
712 snprintf(gl
->gl_strname
, GDLM_STRNAME_BYTES
, "%8x%16llx", name
.ln_type
, (unsigned long long)number
);
713 memset(&gl
->gl_lksb
, 0, sizeof(struct dlm_lksb
));
714 gl
->gl_lksb
.sb_lvbptr
= gl
->gl_lvb
;
715 gl
->gl_tchange
= jiffies
;
716 gl
->gl_object
= NULL
;
718 gl
->gl_aspace
= NULL
;
719 INIT_DELAYED_WORK(&gl
->gl_work
, glock_work_func
);
721 /* If this glock protects actual on-disk data or metadata blocks,
722 create a VFS inode to manage the pages/buffers holding them. */
723 if (glops
== &gfs2_inode_glops
|| glops
== &gfs2_rgrp_glops
) {
724 gl
->gl_aspace
= gfs2_aspace_get(sdp
);
725 if (!gl
->gl_aspace
) {
731 write_lock(gl_lock_addr(hash
));
732 tmp
= search_bucket(hash
, sdp
, &name
);
734 write_unlock(gl_lock_addr(hash
));
738 hlist_add_head(&gl
->gl_list
, &gl_hash_table
[hash
].hb_list
);
739 write_unlock(gl_lock_addr(hash
));
747 kmem_cache_free(gfs2_glock_cachep
, gl
);
752 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
754 * @state: the state we're requesting
755 * @flags: the modifier flags
756 * @gh: the holder structure
760 void gfs2_holder_init(struct gfs2_glock
*gl
, unsigned int state
, unsigned flags
,
761 struct gfs2_holder
*gh
)
763 INIT_LIST_HEAD(&gh
->gh_list
);
765 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
766 gh
->gh_owner_pid
= get_pid(task_pid(current
));
767 gh
->gh_state
= state
;
768 gh
->gh_flags
= flags
;
775 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
776 * @state: the state we're requesting
777 * @flags: the modifier flags
778 * @gh: the holder structure
780 * Don't mess with the glock.
784 void gfs2_holder_reinit(unsigned int state
, unsigned flags
, struct gfs2_holder
*gh
)
786 gh
->gh_state
= state
;
787 gh
->gh_flags
= flags
;
789 gh
->gh_ip
= (unsigned long)__builtin_return_address(0);
793 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
794 * @gh: the holder structure
798 void gfs2_holder_uninit(struct gfs2_holder
*gh
)
800 put_pid(gh
->gh_owner_pid
);
801 gfs2_glock_put(gh
->gh_gl
);
807 * gfs2_glock_holder_wait
810 * This function and gfs2_glock_demote_wait both show up in the WCHAN
811 * field. Thus I've separated these otherwise identical functions in
812 * order to be more informative to the user.
815 static int gfs2_glock_holder_wait(void *word
)
821 static int gfs2_glock_demote_wait(void *word
)
827 static void wait_on_holder(struct gfs2_holder
*gh
)
830 wait_on_bit(&gh
->gh_iflags
, HIF_WAIT
, gfs2_glock_holder_wait
, TASK_UNINTERRUPTIBLE
);
833 static void wait_on_demote(struct gfs2_glock
*gl
)
836 wait_on_bit(&gl
->gl_flags
, GLF_DEMOTE
, gfs2_glock_demote_wait
, TASK_UNINTERRUPTIBLE
);
840 * handle_callback - process a demote request
842 * @state: the state the caller wants us to change to
844 * There are only two requests that we are going to see in actual
845 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
848 static void handle_callback(struct gfs2_glock
*gl
, unsigned int state
,
851 int bit
= delay
? GLF_PENDING_DEMOTE
: GLF_DEMOTE
;
853 set_bit(bit
, &gl
->gl_flags
);
854 if (gl
->gl_demote_state
== LM_ST_EXCLUSIVE
) {
855 gl
->gl_demote_state
= state
;
856 gl
->gl_demote_time
= jiffies
;
857 } else if (gl
->gl_demote_state
!= LM_ST_UNLOCKED
&&
858 gl
->gl_demote_state
!= state
) {
859 gl
->gl_demote_state
= LM_ST_UNLOCKED
;
861 trace_gfs2_demote_rq(gl
);
865 * gfs2_glock_wait - wait on a glock acquisition
866 * @gh: the glock holder
868 * Returns: 0 on success
871 int gfs2_glock_wait(struct gfs2_holder
*gh
)
877 void gfs2_print_dbg(struct seq_file
*seq
, const char *fmt
, ...)
883 struct gfs2_glock_iter
*gi
= seq
->private;
884 vsprintf(gi
->string
, fmt
, args
);
885 seq_printf(seq
, gi
->string
);
887 printk(KERN_ERR
" ");
894 * add_to_queue - Add a holder to the wait queue (but look for recursion)
895 * @gh: the holder structure to add
897 * Eventually we should move the recursive locking trap to a
898 * debugging option or something like that. This is the fast
899 * path and needs to have the minimum number of distractions.
903 static inline void add_to_queue(struct gfs2_holder
*gh
)
904 __releases(&gl
->gl_spin
)
905 __acquires(&gl
->gl_spin
)
907 struct gfs2_glock
*gl
= gh
->gh_gl
;
908 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
909 struct list_head
*insert_pt
= NULL
;
910 struct gfs2_holder
*gh2
;
913 BUG_ON(gh
->gh_owner_pid
== NULL
);
914 if (test_and_set_bit(HIF_WAIT
, &gh
->gh_iflags
))
917 if (gh
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) {
918 if (test_bit(GLF_LOCK
, &gl
->gl_flags
))
920 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, &gl
->gl_flags
))
924 list_for_each_entry(gh2
, &gl
->gl_holders
, gh_list
) {
925 if (unlikely(gh2
->gh_owner_pid
== gh
->gh_owner_pid
&&
926 (gh
->gh_gl
->gl_ops
->go_type
!= LM_TYPE_FLOCK
)))
929 !(gh2
->gh_flags
& (LM_FLAG_TRY
| LM_FLAG_TRY_1CB
)) &&
930 !may_grant(gl
, gh
)) {
932 gh
->gh_error
= GLR_TRYFAILED
;
933 gfs2_holder_wake(gh
);
936 if (test_bit(HIF_HOLDER
, &gh2
->gh_iflags
))
938 if (unlikely((gh
->gh_flags
& LM_FLAG_PRIORITY
) && !insert_pt
))
939 insert_pt
= &gh2
->gh_list
;
941 if (likely(insert_pt
== NULL
)) {
942 list_add_tail(&gh
->gh_list
, &gl
->gl_holders
);
943 if (unlikely(gh
->gh_flags
& LM_FLAG_PRIORITY
))
947 trace_gfs2_glock_queue(gh
, 1);
948 list_add_tail(&gh
->gh_list
, insert_pt
);
950 gh
= list_entry(gl
->gl_holders
.next
, struct gfs2_holder
, gh_list
);
951 if (!(gh
->gh_flags
& LM_FLAG_PRIORITY
)) {
952 spin_unlock(&gl
->gl_spin
);
953 if (sdp
->sd_lockstruct
.ls_ops
->lm_cancel
)
954 sdp
->sd_lockstruct
.ls_ops
->lm_cancel(gl
);
955 spin_lock(&gl
->gl_spin
);
960 print_symbol(KERN_ERR
"original: %s\n", gh2
->gh_ip
);
961 printk(KERN_ERR
"pid: %d\n", pid_nr(gh2
->gh_owner_pid
));
962 printk(KERN_ERR
"lock type: %d req lock state : %d\n",
963 gh2
->gh_gl
->gl_name
.ln_type
, gh2
->gh_state
);
964 print_symbol(KERN_ERR
"new: %s\n", gh
->gh_ip
);
965 printk(KERN_ERR
"pid: %d\n", pid_nr(gh
->gh_owner_pid
));
966 printk(KERN_ERR
"lock type: %d req lock state : %d\n",
967 gh
->gh_gl
->gl_name
.ln_type
, gh
->gh_state
);
968 __dump_glock(NULL
, gl
);
973 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
974 * @gh: the holder structure
976 * if (gh->gh_flags & GL_ASYNC), this never returns an error
978 * Returns: 0, GLR_TRYFAILED, or errno on failure
981 int gfs2_glock_nq(struct gfs2_holder
*gh
)
983 struct gfs2_glock
*gl
= gh
->gh_gl
;
984 struct gfs2_sbd
*sdp
= gl
->gl_sbd
;
987 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
990 spin_lock(&gl
->gl_spin
);
993 spin_unlock(&gl
->gl_spin
);
995 if (!(gh
->gh_flags
& GL_ASYNC
))
996 error
= gfs2_glock_wait(gh
);
1002 * gfs2_glock_poll - poll to see if an async request has been completed
1005 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1008 int gfs2_glock_poll(struct gfs2_holder
*gh
)
1010 return test_bit(HIF_WAIT
, &gh
->gh_iflags
) ? 0 : 1;
1014 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1015 * @gh: the glock holder
1019 void gfs2_glock_dq(struct gfs2_holder
*gh
)
1021 struct gfs2_glock
*gl
= gh
->gh_gl
;
1022 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1026 spin_lock(&gl
->gl_spin
);
1027 if (gh
->gh_flags
& GL_NOCACHE
)
1028 handle_callback(gl
, LM_ST_UNLOCKED
, 0);
1030 list_del_init(&gh
->gh_list
);
1031 if (find_first_holder(gl
) == NULL
) {
1032 if (glops
->go_unlock
) {
1033 GLOCK_BUG_ON(gl
, test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
));
1034 spin_unlock(&gl
->gl_spin
);
1035 glops
->go_unlock(gh
);
1036 spin_lock(&gl
->gl_spin
);
1037 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1039 if (list_empty(&gl
->gl_holders
) &&
1040 !test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
1041 !test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1044 trace_gfs2_glock_queue(gh
, 0);
1045 spin_unlock(&gl
->gl_spin
);
1046 if (likely(fast_path
))
1049 gfs2_glock_hold(gl
);
1050 if (test_bit(GLF_PENDING_DEMOTE
, &gl
->gl_flags
) &&
1051 !test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1052 delay
= gl
->gl_ops
->go_min_hold_time
;
1053 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
1057 void gfs2_glock_dq_wait(struct gfs2_holder
*gh
)
1059 struct gfs2_glock
*gl
= gh
->gh_gl
;
1065 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1066 * @gh: the holder structure
1070 void gfs2_glock_dq_uninit(struct gfs2_holder
*gh
)
1073 gfs2_holder_uninit(gh
);
1077 * gfs2_glock_nq_num - acquire a glock based on lock number
1078 * @sdp: the filesystem
1079 * @number: the lock number
1080 * @glops: the glock operations for the type of glock
1081 * @state: the state to acquire the glock in
1082 * @flags: modifier flags for the aquisition
1083 * @gh: the struct gfs2_holder
1088 int gfs2_glock_nq_num(struct gfs2_sbd
*sdp
, u64 number
,
1089 const struct gfs2_glock_operations
*glops
,
1090 unsigned int state
, int flags
, struct gfs2_holder
*gh
)
1092 struct gfs2_glock
*gl
;
1095 error
= gfs2_glock_get(sdp
, number
, glops
, CREATE
, &gl
);
1097 error
= gfs2_glock_nq_init(gl
, state
, flags
, gh
);
1105 * glock_compare - Compare two struct gfs2_glock structures for sorting
1106 * @arg_a: the first structure
1107 * @arg_b: the second structure
1111 static int glock_compare(const void *arg_a
, const void *arg_b
)
1113 const struct gfs2_holder
*gh_a
= *(const struct gfs2_holder
**)arg_a
;
1114 const struct gfs2_holder
*gh_b
= *(const struct gfs2_holder
**)arg_b
;
1115 const struct lm_lockname
*a
= &gh_a
->gh_gl
->gl_name
;
1116 const struct lm_lockname
*b
= &gh_b
->gh_gl
->gl_name
;
1118 if (a
->ln_number
> b
->ln_number
)
1120 if (a
->ln_number
< b
->ln_number
)
1122 BUG_ON(gh_a
->gh_gl
->gl_ops
->go_type
== gh_b
->gh_gl
->gl_ops
->go_type
);
1127 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1128 * @num_gh: the number of structures
1129 * @ghs: an array of struct gfs2_holder structures
1131 * Returns: 0 on success (all glocks acquired),
1132 * errno on failure (no glocks acquired)
1135 static int nq_m_sync(unsigned int num_gh
, struct gfs2_holder
*ghs
,
1136 struct gfs2_holder
**p
)
1141 for (x
= 0; x
< num_gh
; x
++)
1144 sort(p
, num_gh
, sizeof(struct gfs2_holder
*), glock_compare
, NULL
);
1146 for (x
= 0; x
< num_gh
; x
++) {
1147 p
[x
]->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1149 error
= gfs2_glock_nq(p
[x
]);
1152 gfs2_glock_dq(p
[x
]);
1161 * gfs2_glock_nq_m - acquire multiple glocks
1162 * @num_gh: the number of structures
1163 * @ghs: an array of struct gfs2_holder structures
1166 * Returns: 0 on success (all glocks acquired),
1167 * errno on failure (no glocks acquired)
1170 int gfs2_glock_nq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1172 struct gfs2_holder
*tmp
[4];
1173 struct gfs2_holder
**pph
= tmp
;
1180 ghs
->gh_flags
&= ~(LM_FLAG_TRY
| GL_ASYNC
);
1181 return gfs2_glock_nq(ghs
);
1185 pph
= kmalloc(num_gh
* sizeof(struct gfs2_holder
*), GFP_NOFS
);
1190 error
= nq_m_sync(num_gh
, ghs
, pph
);
1199 * gfs2_glock_dq_m - release multiple glocks
1200 * @num_gh: the number of structures
1201 * @ghs: an array of struct gfs2_holder structures
1205 void gfs2_glock_dq_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1209 for (x
= 0; x
< num_gh
; x
++)
1210 gfs2_glock_dq(&ghs
[x
]);
1214 * gfs2_glock_dq_uninit_m - release multiple glocks
1215 * @num_gh: the number of structures
1216 * @ghs: an array of struct gfs2_holder structures
1220 void gfs2_glock_dq_uninit_m(unsigned int num_gh
, struct gfs2_holder
*ghs
)
1224 for (x
= 0; x
< num_gh
; x
++)
1225 gfs2_glock_dq_uninit(&ghs
[x
]);
1228 void gfs2_glock_cb(struct gfs2_glock
*gl
, unsigned int state
)
1230 unsigned long delay
= 0;
1231 unsigned long holdtime
;
1232 unsigned long now
= jiffies
;
1234 gfs2_glock_hold(gl
);
1235 holdtime
= gl
->gl_tchange
+ gl
->gl_ops
->go_min_hold_time
;
1236 if (time_before(now
, holdtime
))
1237 delay
= holdtime
- now
;
1238 if (test_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
))
1239 delay
= gl
->gl_ops
->go_min_hold_time
;
1241 spin_lock(&gl
->gl_spin
);
1242 handle_callback(gl
, state
, delay
);
1243 spin_unlock(&gl
->gl_spin
);
1244 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, delay
) == 0)
1249 * gfs2_glock_complete - Callback used by locking
1250 * @gl: Pointer to the glock
1251 * @ret: The return value from the dlm
1255 void gfs2_glock_complete(struct gfs2_glock
*gl
, int ret
)
1257 struct lm_lockstruct
*ls
= &gl
->gl_sbd
->sd_lockstruct
;
1259 if (unlikely(test_bit(DFL_BLOCK_LOCKS
, &ls
->ls_flags
))) {
1260 struct gfs2_holder
*gh
;
1261 spin_lock(&gl
->gl_spin
);
1262 gh
= find_first_waiter(gl
);
1263 if ((!(gh
&& (gh
->gh_flags
& LM_FLAG_NOEXP
)) &&
1264 (gl
->gl_target
!= LM_ST_UNLOCKED
)) ||
1265 ((ret
& ~LM_OUT_ST_MASK
) != 0))
1266 set_bit(GLF_FROZEN
, &gl
->gl_flags
);
1267 spin_unlock(&gl
->gl_spin
);
1268 if (test_bit(GLF_FROZEN
, &gl
->gl_flags
))
1271 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1272 gfs2_glock_hold(gl
);
1273 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1278 * demote_ok - Check to see if it's ok to unlock a glock
1281 * Returns: 1 if it's ok
1284 static int demote_ok(const struct gfs2_glock
*gl
)
1286 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1288 if (gl
->gl_state
== LM_ST_UNLOCKED
)
1290 if (!list_empty(&gl
->gl_holders
))
1292 if (glops
->go_demote_ok
)
1293 return glops
->go_demote_ok(gl
);
1298 static int gfs2_shrink_glock_memory(int nr
, gfp_t gfp_mask
)
1300 struct gfs2_glock
*gl
;
1308 if (!(gfp_mask
& __GFP_FS
))
1311 spin_lock(&lru_lock
);
1312 while(nr
&& !list_empty(&lru_list
)) {
1313 gl
= list_entry(lru_list
.next
, struct gfs2_glock
, gl_lru
);
1314 list_del_init(&gl
->gl_lru
);
1315 atomic_dec(&lru_count
);
1317 /* Check if glock is about to be freed */
1318 if (atomic_read(&gl
->gl_ref
) == 0)
1321 /* Test for being demotable */
1322 if (!test_and_set_bit(GLF_LOCK
, &gl
->gl_flags
)) {
1323 gfs2_glock_hold(gl
);
1324 spin_unlock(&lru_lock
);
1325 spin_lock(&gl
->gl_spin
);
1326 may_demote
= demote_ok(gl
);
1327 spin_unlock(&gl
->gl_spin
);
1328 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1330 handle_callback(gl
, LM_ST_UNLOCKED
, 0);
1333 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1335 spin_lock(&lru_lock
);
1339 list_add(&gl
->gl_lru
, &skipped
);
1341 list_splice(&skipped
, &lru_list
);
1342 atomic_add(nr_skipped
, &lru_count
);
1343 spin_unlock(&lru_lock
);
1345 return (atomic_read(&lru_count
) / 100) * sysctl_vfs_cache_pressure
;
1348 static struct shrinker glock_shrinker
= {
1349 .shrink
= gfs2_shrink_glock_memory
,
1350 .seeks
= DEFAULT_SEEKS
,
1354 * examine_bucket - Call a function for glock in a hash bucket
1355 * @examiner: the function
1356 * @sdp: the filesystem
1357 * @bucket: the bucket
1359 * Returns: 1 if the bucket has entries
1362 static int examine_bucket(glock_examiner examiner
, struct gfs2_sbd
*sdp
,
1365 struct gfs2_glock
*gl
, *prev
= NULL
;
1366 int has_entries
= 0;
1367 struct hlist_head
*head
= &gl_hash_table
[hash
].hb_list
;
1369 read_lock(gl_lock_addr(hash
));
1370 /* Can't use hlist_for_each_entry - don't want prefetch here */
1371 if (hlist_empty(head
))
1373 gl
= list_entry(head
->first
, struct gfs2_glock
, gl_list
);
1375 if (!sdp
|| gl
->gl_sbd
== sdp
) {
1376 gfs2_glock_hold(gl
);
1377 read_unlock(gl_lock_addr(hash
));
1379 gfs2_glock_put(prev
);
1383 read_lock(gl_lock_addr(hash
));
1385 if (gl
->gl_list
.next
== NULL
)
1387 gl
= list_entry(gl
->gl_list
.next
, struct gfs2_glock
, gl_list
);
1390 read_unlock(gl_lock_addr(hash
));
1392 gfs2_glock_put(prev
);
1399 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1400 * @gl: The glock to thaw
1402 * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
1403 * so this has to result in the ref count being dropped by one.
1406 static void thaw_glock(struct gfs2_glock
*gl
)
1408 if (!test_and_clear_bit(GLF_FROZEN
, &gl
->gl_flags
))
1410 set_bit(GLF_REPLY_PENDING
, &gl
->gl_flags
);
1411 gfs2_glock_hold(gl
);
1412 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1417 * clear_glock - look at a glock and see if we can free it from glock cache
1418 * @gl: the glock to look at
1422 static void clear_glock(struct gfs2_glock
*gl
)
1424 spin_lock(&lru_lock
);
1425 if (!list_empty(&gl
->gl_lru
)) {
1426 list_del_init(&gl
->gl_lru
);
1427 atomic_dec(&lru_count
);
1429 spin_unlock(&lru_lock
);
1431 spin_lock(&gl
->gl_spin
);
1432 if (find_first_holder(gl
) == NULL
&& gl
->gl_state
!= LM_ST_UNLOCKED
)
1433 handle_callback(gl
, LM_ST_UNLOCKED
, 0);
1434 spin_unlock(&gl
->gl_spin
);
1435 gfs2_glock_hold(gl
);
1436 if (queue_delayed_work(glock_workqueue
, &gl
->gl_work
, 0) == 0)
1441 * gfs2_glock_thaw - Thaw any frozen glocks
1442 * @sdp: The super block
1446 void gfs2_glock_thaw(struct gfs2_sbd
*sdp
)
1450 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++)
1451 examine_bucket(thaw_glock
, sdp
, x
);
1455 * gfs2_gl_hash_clear - Empty out the glock hash table
1456 * @sdp: the filesystem
1457 * @wait: wait until it's all gone
1459 * Called when unmounting the filesystem.
1462 void gfs2_gl_hash_clear(struct gfs2_sbd
*sdp
)
1472 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1473 if (examine_bucket(clear_glock
, sdp
, x
))
1480 if (time_after_eq(jiffies
,
1481 t
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
)) {
1482 fs_warn(sdp
, "Unmount seems to be stalled. "
1483 "Dumping lock state...\n");
1484 gfs2_dump_lockstate(sdp
);
1488 down_write(&gfs2_umount_flush_sem
);
1489 invalidate_inodes(sdp
->sd_vfs
);
1490 up_write(&gfs2_umount_flush_sem
);
1495 void gfs2_glock_finish_truncate(struct gfs2_inode
*ip
)
1497 struct gfs2_glock
*gl
= ip
->i_gl
;
1500 ret
= gfs2_truncatei_resume(ip
);
1501 gfs2_assert_withdraw(gl
->gl_sbd
, ret
== 0);
1503 spin_lock(&gl
->gl_spin
);
1504 clear_bit(GLF_LOCK
, &gl
->gl_flags
);
1506 spin_unlock(&gl
->gl_spin
);
1509 static const char *state2str(unsigned state
)
1512 case LM_ST_UNLOCKED
:
1516 case LM_ST_DEFERRED
:
1518 case LM_ST_EXCLUSIVE
:
1524 static const char *hflags2str(char *buf
, unsigned flags
, unsigned long iflags
)
1527 if (flags
& LM_FLAG_TRY
)
1529 if (flags
& LM_FLAG_TRY_1CB
)
1531 if (flags
& LM_FLAG_NOEXP
)
1533 if (flags
& LM_FLAG_ANY
)
1535 if (flags
& LM_FLAG_PRIORITY
)
1537 if (flags
& GL_ASYNC
)
1539 if (flags
& GL_EXACT
)
1541 if (flags
& GL_NOCACHE
)
1543 if (test_bit(HIF_HOLDER
, &iflags
))
1545 if (test_bit(HIF_WAIT
, &iflags
))
1547 if (test_bit(HIF_FIRST
, &iflags
))
1554 * dump_holder - print information about a glock holder
1555 * @seq: the seq_file struct
1556 * @gh: the glock holder
1558 * Returns: 0 on success, -ENOBUFS when we run out of space
1561 static int dump_holder(struct seq_file
*seq
, const struct gfs2_holder
*gh
)
1563 struct task_struct
*gh_owner
= NULL
;
1564 char buffer
[KSYM_SYMBOL_LEN
];
1567 sprint_symbol(buffer
, gh
->gh_ip
);
1568 if (gh
->gh_owner_pid
)
1569 gh_owner
= pid_task(gh
->gh_owner_pid
, PIDTYPE_PID
);
1570 gfs2_print_dbg(seq
, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
1571 state2str(gh
->gh_state
),
1572 hflags2str(flags_buf
, gh
->gh_flags
, gh
->gh_iflags
),
1574 gh
->gh_owner_pid
? (long)pid_nr(gh
->gh_owner_pid
) : -1,
1575 gh_owner
? gh_owner
->comm
: "(ended)", buffer
);
1579 static const char *gflags2str(char *buf
, const unsigned long *gflags
)
1582 if (test_bit(GLF_LOCK
, gflags
))
1584 if (test_bit(GLF_DEMOTE
, gflags
))
1586 if (test_bit(GLF_PENDING_DEMOTE
, gflags
))
1588 if (test_bit(GLF_DEMOTE_IN_PROGRESS
, gflags
))
1590 if (test_bit(GLF_DIRTY
, gflags
))
1592 if (test_bit(GLF_LFLUSH
, gflags
))
1594 if (test_bit(GLF_INVALIDATE_IN_PROGRESS
, gflags
))
1596 if (test_bit(GLF_REPLY_PENDING
, gflags
))
1598 if (test_bit(GLF_INITIAL
, gflags
))
1600 if (test_bit(GLF_FROZEN
, gflags
))
1607 * __dump_glock - print information about a glock
1608 * @seq: The seq_file struct
1611 * The file format is as follows:
1612 * One line per object, capital letters are used to indicate objects
1613 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1614 * other objects are indented by a single space and follow the glock to
1615 * which they are related. Fields are indicated by lower case letters
1616 * followed by a colon and the field value, except for strings which are in
1617 * [] so that its possible to see if they are composed of spaces for
1618 * example. The field's are n = number (id of the object), f = flags,
1619 * t = type, s = state, r = refcount, e = error, p = pid.
1621 * Returns: 0 on success, -ENOBUFS when we run out of space
1624 static int __dump_glock(struct seq_file
*seq
, const struct gfs2_glock
*gl
)
1626 const struct gfs2_glock_operations
*glops
= gl
->gl_ops
;
1627 unsigned long long dtime
;
1628 const struct gfs2_holder
*gh
;
1629 char gflags_buf
[32];
1632 dtime
= jiffies
- gl
->gl_demote_time
;
1633 dtime
*= 1000000/HZ
; /* demote time in uSec */
1634 if (!test_bit(GLF_DEMOTE
, &gl
->gl_flags
))
1636 gfs2_print_dbg(seq
, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu a:%d r:%d\n",
1637 state2str(gl
->gl_state
),
1638 gl
->gl_name
.ln_type
,
1639 (unsigned long long)gl
->gl_name
.ln_number
,
1640 gflags2str(gflags_buf
, &gl
->gl_flags
),
1641 state2str(gl
->gl_target
),
1642 state2str(gl
->gl_demote_state
), dtime
,
1643 atomic_read(&gl
->gl_ail_count
),
1644 atomic_read(&gl
->gl_ref
));
1646 list_for_each_entry(gh
, &gl
->gl_holders
, gh_list
) {
1647 error
= dump_holder(seq
, gh
);
1651 if (gl
->gl_state
!= LM_ST_UNLOCKED
&& glops
->go_dump
)
1652 error
= glops
->go_dump(seq
, gl
);
1657 static int dump_glock(struct seq_file
*seq
, struct gfs2_glock
*gl
)
1660 spin_lock(&gl
->gl_spin
);
1661 ret
= __dump_glock(seq
, gl
);
1662 spin_unlock(&gl
->gl_spin
);
1667 * gfs2_dump_lockstate - print out the current lockstate
1668 * @sdp: the filesystem
1669 * @ub: the buffer to copy the information into
1671 * If @ub is NULL, dump the lockstate to the console.
1675 static int gfs2_dump_lockstate(struct gfs2_sbd
*sdp
)
1677 struct gfs2_glock
*gl
;
1678 struct hlist_node
*h
;
1682 for (x
= 0; x
< GFS2_GL_HASH_SIZE
; x
++) {
1684 read_lock(gl_lock_addr(x
));
1686 hlist_for_each_entry(gl
, h
, &gl_hash_table
[x
].hb_list
, gl_list
) {
1687 if (gl
->gl_sbd
!= sdp
)
1690 error
= dump_glock(NULL
, gl
);
1695 read_unlock(gl_lock_addr(x
));
1706 int __init
gfs2_glock_init(void)
1709 for(i
= 0; i
< GFS2_GL_HASH_SIZE
; i
++) {
1710 INIT_HLIST_HEAD(&gl_hash_table
[i
].hb_list
);
1712 #ifdef GL_HASH_LOCK_SZ
1713 for(i
= 0; i
< GL_HASH_LOCK_SZ
; i
++) {
1714 rwlock_init(&gl_hash_locks
[i
]);
1718 glock_workqueue
= create_workqueue("glock_workqueue");
1719 if (IS_ERR(glock_workqueue
))
1720 return PTR_ERR(glock_workqueue
);
1722 register_shrinker(&glock_shrinker
);
1727 void gfs2_glock_exit(void)
1729 unregister_shrinker(&glock_shrinker
);
1730 destroy_workqueue(glock_workqueue
);
1733 static int gfs2_glock_iter_next(struct gfs2_glock_iter
*gi
)
1735 struct gfs2_glock
*gl
;
1738 read_lock(gl_lock_addr(gi
->hash
));
1741 gi
->gl
= hlist_entry(gl
->gl_list
.next
,
1742 struct gfs2_glock
, gl_list
);
1744 gi
->gl
= hlist_entry(gl_hash_table
[gi
->hash
].hb_list
.first
,
1745 struct gfs2_glock
, gl_list
);
1748 gfs2_glock_hold(gi
->gl
);
1749 read_unlock(gl_lock_addr(gi
->hash
));
1752 while (gi
->gl
== NULL
) {
1754 if (gi
->hash
>= GFS2_GL_HASH_SIZE
)
1756 read_lock(gl_lock_addr(gi
->hash
));
1757 gi
->gl
= hlist_entry(gl_hash_table
[gi
->hash
].hb_list
.first
,
1758 struct gfs2_glock
, gl_list
);
1760 gfs2_glock_hold(gi
->gl
);
1761 read_unlock(gl_lock_addr(gi
->hash
));
1764 if (gi
->sdp
!= gi
->gl
->gl_sbd
)
1770 static void gfs2_glock_iter_free(struct gfs2_glock_iter
*gi
)
1773 gfs2_glock_put(gi
->gl
);
1777 static void *gfs2_glock_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1779 struct gfs2_glock_iter
*gi
= seq
->private;
1785 if (gfs2_glock_iter_next(gi
)) {
1786 gfs2_glock_iter_free(gi
);
1794 static void *gfs2_glock_seq_next(struct seq_file
*seq
, void *iter_ptr
,
1797 struct gfs2_glock_iter
*gi
= seq
->private;
1801 if (gfs2_glock_iter_next(gi
)) {
1802 gfs2_glock_iter_free(gi
);
1809 static void gfs2_glock_seq_stop(struct seq_file
*seq
, void *iter_ptr
)
1811 struct gfs2_glock_iter
*gi
= seq
->private;
1812 gfs2_glock_iter_free(gi
);
1815 static int gfs2_glock_seq_show(struct seq_file
*seq
, void *iter_ptr
)
1817 return dump_glock(seq
, iter_ptr
);
1820 static const struct seq_operations gfs2_glock_seq_ops
= {
1821 .start
= gfs2_glock_seq_start
,
1822 .next
= gfs2_glock_seq_next
,
1823 .stop
= gfs2_glock_seq_stop
,
1824 .show
= gfs2_glock_seq_show
,
1827 static int gfs2_debugfs_open(struct inode
*inode
, struct file
*file
)
1829 int ret
= seq_open_private(file
, &gfs2_glock_seq_ops
,
1830 sizeof(struct gfs2_glock_iter
));
1832 struct seq_file
*seq
= file
->private_data
;
1833 struct gfs2_glock_iter
*gi
= seq
->private;
1834 gi
->sdp
= inode
->i_private
;
1839 static const struct file_operations gfs2_debug_fops
= {
1840 .owner
= THIS_MODULE
,
1841 .open
= gfs2_debugfs_open
,
1843 .llseek
= seq_lseek
,
1844 .release
= seq_release_private
,
1847 int gfs2_create_debugfs_file(struct gfs2_sbd
*sdp
)
1849 sdp
->debugfs_dir
= debugfs_create_dir(sdp
->sd_table_name
, gfs2_root
);
1850 if (!sdp
->debugfs_dir
)
1852 sdp
->debugfs_dentry_glocks
= debugfs_create_file("glocks",
1854 sdp
->debugfs_dir
, sdp
,
1856 if (!sdp
->debugfs_dentry_glocks
)
1862 void gfs2_delete_debugfs_file(struct gfs2_sbd
*sdp
)
1864 if (sdp
&& sdp
->debugfs_dir
) {
1865 if (sdp
->debugfs_dentry_glocks
) {
1866 debugfs_remove(sdp
->debugfs_dentry_glocks
);
1867 sdp
->debugfs_dentry_glocks
= NULL
;
1869 debugfs_remove(sdp
->debugfs_dir
);
1870 sdp
->debugfs_dir
= NULL
;
1874 int gfs2_register_debugfs(void)
1876 gfs2_root
= debugfs_create_dir("gfs2", NULL
);
1877 return gfs2_root
? 0 : -ENOMEM
;
1880 void gfs2_unregister_debugfs(void)
1882 debugfs_remove(gfs2_root
);