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 = 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;
655 gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
656 if (gl && !lockref_get_not_dead(&gl->gl_lockref))
666 if (glops->go_flags & GLOF_ASPACE)
667 cachep = gfs2_glock_aspace_cachep;
669 cachep = gfs2_glock_cachep;
670 gl = kmem_cache_alloc(cachep, GFP_NOFS);
674 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
676 if (glops->go_flags & GLOF_LVB) {
677 gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_NOFS);
678 if (!gl->gl_lksb.sb_lvbptr) {
679 kmem_cache_free(cachep, gl);
684 atomic_inc(&sdp->sd_glock_disposal);
685 gl->gl_node.next = NULL;
688 gl->gl_lockref.count = 1;
689 gl->gl_state = LM_ST_UNLOCKED;
690 gl->gl_target = LM_ST_UNLOCKED;
691 gl->gl_demote_state = LM_ST_EXCLUSIVE;
693 gl->gl_dstamp = ktime_set(0, 0);
695 /* We use the global stats to estimate the initial per-glock stats */
696 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
698 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
699 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
700 gl->gl_tchange = jiffies;
701 gl->gl_object = NULL;
702 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
703 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
704 INIT_WORK(&gl->gl_delete, delete_work_func);
706 mapping = gfs2_glock2aspace(gl);
708 mapping->a_ops = &gfs2_meta_aops;
709 mapping->host = s->s_bdev->bd_inode;
711 mapping_set_gfp_mask(mapping, GFP_NOFS);
712 mapping->private_data = NULL;
713 mapping->writeback_index = 0;
717 ret = rhashtable_lookup_insert_fast(&gl_hash_table, &gl->gl_node,
724 if (ret == -EEXIST) {
727 tmp = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
728 if (tmp == NULL || !lockref_get_not_dead(&tmp->gl_lockref)) {
741 kfree(gl->gl_lksb.sb_lvbptr);
742 kmem_cache_free(cachep, gl);
743 atomic_dec(&sdp->sd_glock_disposal);
750 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
752 * @state: the state we're requesting
753 * @flags: the modifier flags
754 * @gh: the holder structure
758 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
759 struct gfs2_holder *gh)
761 INIT_LIST_HEAD(&gh->gh_list);
763 gh->gh_ip = _RET_IP_;
764 gh->gh_owner_pid = get_pid(task_pid(current));
765 gh->gh_state = state;
766 gh->gh_flags = flags;
773 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
774 * @state: the state we're requesting
775 * @flags: the modifier flags
776 * @gh: the holder structure
778 * Don't mess with the glock.
782 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
784 gh->gh_state = state;
785 gh->gh_flags = flags;
787 gh->gh_ip = _RET_IP_;
788 put_pid(gh->gh_owner_pid);
789 gh->gh_owner_pid = get_pid(task_pid(current));
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_wait - wait on a glock acquisition
808 * @gh: the glock holder
810 * Returns: 0 on success
813 int gfs2_glock_wait(struct gfs2_holder *gh)
815 unsigned long time1 = jiffies;
818 wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
819 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
820 /* Lengthen the minimum hold time. */
821 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
828 * handle_callback - process a demote request
830 * @state: the state the caller wants us to change to
832 * There are only two requests that we are going to see in actual
833 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
836 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
837 unsigned long delay, bool remote)
839 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
841 set_bit(bit, &gl->gl_flags);
842 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
843 gl->gl_demote_state = state;
844 gl->gl_demote_time = jiffies;
845 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
846 gl->gl_demote_state != state) {
847 gl->gl_demote_state = LM_ST_UNLOCKED;
849 if (gl->gl_ops->go_callback)
850 gl->gl_ops->go_callback(gl, remote);
851 trace_gfs2_demote_rq(gl, remote);
854 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
856 struct va_format vaf;
862 seq_vprintf(seq, fmt, args);
874 * add_to_queue - Add a holder to the wait queue (but look for recursion)
875 * @gh: the holder structure to add
877 * Eventually we should move the recursive locking trap to a
878 * debugging option or something like that. This is the fast
879 * path and needs to have the minimum number of distractions.
883 static inline void add_to_queue(struct gfs2_holder *gh)
884 __releases(&gl->gl_lockref.lock)
885 __acquires(&gl->gl_lockref.lock)
887 struct gfs2_glock *gl = gh->gh_gl;
888 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
889 struct list_head *insert_pt = NULL;
890 struct gfs2_holder *gh2;
893 BUG_ON(gh->gh_owner_pid == NULL);
894 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
897 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
898 if (test_bit(GLF_LOCK, &gl->gl_flags))
899 try_futile = !may_grant(gl, gh);
900 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
904 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
905 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
906 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
909 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
911 gh->gh_error = GLR_TRYFAILED;
912 gfs2_holder_wake(gh);
915 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
917 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
918 insert_pt = &gh2->gh_list;
920 set_bit(GLF_QUEUED, &gl->gl_flags);
921 trace_gfs2_glock_queue(gh, 1);
922 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
923 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
924 if (likely(insert_pt == NULL)) {
925 list_add_tail(&gh->gh_list, &gl->gl_holders);
926 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
930 list_add_tail(&gh->gh_list, insert_pt);
932 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
933 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
934 spin_unlock(&gl->gl_lockref.lock);
935 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
936 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
937 spin_lock(&gl->gl_lockref.lock);
942 pr_err("original: %pSR\n", (void *)gh2->gh_ip);
943 pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid));
944 pr_err("lock type: %d req lock state : %d\n",
945 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
946 pr_err("new: %pSR\n", (void *)gh->gh_ip);
947 pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid));
948 pr_err("lock type: %d req lock state : %d\n",
949 gh->gh_gl->gl_name.ln_type, gh->gh_state);
950 gfs2_dump_glock(NULL, gl);
955 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
956 * @gh: the holder structure
958 * if (gh->gh_flags & GL_ASYNC), this never returns an error
960 * Returns: 0, GLR_TRYFAILED, or errno on failure
963 int gfs2_glock_nq(struct gfs2_holder *gh)
965 struct gfs2_glock *gl = gh->gh_gl;
966 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
969 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
972 if (test_bit(GLF_LRU, &gl->gl_flags))
973 gfs2_glock_remove_from_lru(gl);
975 spin_lock(&gl->gl_lockref.lock);
977 if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
978 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
979 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
980 gl->gl_lockref.count++;
981 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
982 gl->gl_lockref.count--;
985 spin_unlock(&gl->gl_lockref.lock);
987 if (!(gh->gh_flags & GL_ASYNC))
988 error = gfs2_glock_wait(gh);
994 * gfs2_glock_poll - poll to see if an async request has been completed
997 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1000 int gfs2_glock_poll(struct gfs2_holder *gh)
1002 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1006 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1007 * @gh: the glock holder
1011 void gfs2_glock_dq(struct gfs2_holder *gh)
1013 struct gfs2_glock *gl = gh->gh_gl;
1014 const struct gfs2_glock_operations *glops = gl->gl_ops;
1018 spin_lock(&gl->gl_lockref.lock);
1019 if (gh->gh_flags & GL_NOCACHE)
1020 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1022 list_del_init(&gh->gh_list);
1023 if (find_first_holder(gl) == NULL) {
1024 if (glops->go_unlock) {
1025 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1026 spin_unlock(&gl->gl_lockref.lock);
1027 glops->go_unlock(gh);
1028 spin_lock(&gl->gl_lockref.lock);
1029 clear_bit(GLF_LOCK, &gl->gl_flags);
1031 if (list_empty(&gl->gl_holders) &&
1032 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1033 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1036 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl) &&
1037 (glops->go_flags & GLOF_LRU))
1038 gfs2_glock_add_to_lru(gl);
1040 trace_gfs2_glock_queue(gh, 0);
1041 spin_unlock(&gl->gl_lockref.lock);
1042 if (likely(fast_path))
1045 gfs2_glock_hold(gl);
1046 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1047 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1048 gl->gl_name.ln_type == LM_TYPE_INODE)
1049 delay = gl->gl_hold_time;
1050 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1054 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1056 struct gfs2_glock *gl = gh->gh_gl;
1059 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
1063 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1064 * @gh: the holder structure
1068 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1071 gfs2_holder_uninit(gh);
1075 * gfs2_glock_nq_num - acquire a glock based on lock number
1076 * @sdp: the filesystem
1077 * @number: the lock number
1078 * @glops: the glock operations for the type of glock
1079 * @state: the state to acquire the glock in
1080 * @flags: modifier flags for the acquisition
1081 * @gh: the struct gfs2_holder
1086 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1087 const struct gfs2_glock_operations *glops,
1088 unsigned int state, int flags, struct gfs2_holder *gh)
1090 struct gfs2_glock *gl;
1093 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1095 error = gfs2_glock_nq_init(gl, state, flags, gh);
1103 * glock_compare - Compare two struct gfs2_glock structures for sorting
1104 * @arg_a: the first structure
1105 * @arg_b: the second structure
1109 static int glock_compare(const void *arg_a, const void *arg_b)
1111 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1112 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1113 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1114 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1116 if (a->ln_number > b->ln_number)
1118 if (a->ln_number < b->ln_number)
1120 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1125 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1126 * @num_gh: the number of structures
1127 * @ghs: an array of struct gfs2_holder structures
1129 * Returns: 0 on success (all glocks acquired),
1130 * errno on failure (no glocks acquired)
1133 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1134 struct gfs2_holder **p)
1139 for (x = 0; x < num_gh; x++)
1142 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1144 for (x = 0; x < num_gh; x++) {
1145 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1147 error = gfs2_glock_nq(p[x]);
1150 gfs2_glock_dq(p[x]);
1159 * gfs2_glock_nq_m - acquire multiple glocks
1160 * @num_gh: the number of structures
1161 * @ghs: an array of struct gfs2_holder structures
1164 * Returns: 0 on success (all glocks acquired),
1165 * errno on failure (no glocks acquired)
1168 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1170 struct gfs2_holder *tmp[4];
1171 struct gfs2_holder **pph = tmp;
1178 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1179 return gfs2_glock_nq(ghs);
1183 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1188 error = nq_m_sync(num_gh, ghs, pph);
1197 * gfs2_glock_dq_m - release multiple glocks
1198 * @num_gh: the number of structures
1199 * @ghs: an array of struct gfs2_holder structures
1203 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1206 gfs2_glock_dq(&ghs[num_gh]);
1209 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1211 unsigned long delay = 0;
1212 unsigned long holdtime;
1213 unsigned long now = jiffies;
1215 gfs2_glock_hold(gl);
1216 holdtime = gl->gl_tchange + gl->gl_hold_time;
1217 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1218 gl->gl_name.ln_type == LM_TYPE_INODE) {
1219 if (time_before(now, holdtime))
1220 delay = holdtime - now;
1221 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1222 delay = gl->gl_hold_time;
1225 spin_lock(&gl->gl_lockref.lock);
1226 handle_callback(gl, state, delay, true);
1227 spin_unlock(&gl->gl_lockref.lock);
1228 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1233 * gfs2_should_freeze - Figure out if glock should be frozen
1234 * @gl: The glock in question
1236 * Glocks are not frozen if (a) the result of the dlm operation is
1237 * an error, (b) the locking operation was an unlock operation or
1238 * (c) if there is a "noexp" flagged request anywhere in the queue
1240 * Returns: 1 if freezing should occur, 0 otherwise
1243 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1245 const struct gfs2_holder *gh;
1247 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1249 if (gl->gl_target == LM_ST_UNLOCKED)
1252 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1253 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1255 if (LM_FLAG_NOEXP & gh->gh_flags)
1263 * gfs2_glock_complete - Callback used by locking
1264 * @gl: Pointer to the glock
1265 * @ret: The return value from the dlm
1267 * The gl_reply field is under the gl_lockref.lock lock so that it is ok
1268 * to use a bitfield shared with other glock state fields.
1271 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1273 struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
1275 spin_lock(&gl->gl_lockref.lock);
1278 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1279 if (gfs2_should_freeze(gl)) {
1280 set_bit(GLF_FROZEN, &gl->gl_flags);
1281 spin_unlock(&gl->gl_lockref.lock);
1286 gl->gl_lockref.count++;
1287 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1288 spin_unlock(&gl->gl_lockref.lock);
1290 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1294 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1296 struct gfs2_glock *gla, *glb;
1298 gla = list_entry(a, struct gfs2_glock, gl_lru);
1299 glb = list_entry(b, struct gfs2_glock, gl_lru);
1301 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1303 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1310 * gfs2_dispose_glock_lru - Demote a list of glocks
1311 * @list: The list to dispose of
1313 * Disposing of glocks may involve disk accesses, so that here we sort
1314 * the glocks by number (i.e. disk location of the inodes) so that if
1315 * there are any such accesses, they'll be sent in order (mostly).
1317 * Must be called under the lru_lock, but may drop and retake this
1318 * lock. While the lru_lock is dropped, entries may vanish from the
1319 * list, but no new entries will appear on the list (since it is
1323 static void gfs2_dispose_glock_lru(struct list_head *list)
1324 __releases(&lru_lock)
1325 __acquires(&lru_lock)
1327 struct gfs2_glock *gl;
1329 list_sort(NULL, list, glock_cmp);
1331 while(!list_empty(list)) {
1332 gl = list_entry(list->next, struct gfs2_glock, gl_lru);
1333 list_del_init(&gl->gl_lru);
1334 if (!spin_trylock(&gl->gl_lockref.lock)) {
1336 list_add(&gl->gl_lru, &lru_list);
1337 atomic_inc(&lru_count);
1340 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1341 spin_unlock(&gl->gl_lockref.lock);
1342 goto add_back_to_lru;
1344 clear_bit(GLF_LRU, &gl->gl_flags);
1345 gl->gl_lockref.count++;
1347 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1348 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1349 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1350 gl->gl_lockref.count--;
1351 spin_unlock(&gl->gl_lockref.lock);
1352 cond_resched_lock(&lru_lock);
1357 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1358 * @nr: The number of entries to scan
1360 * This function selects the entries on the LRU which are able to
1361 * be demoted, and then kicks off the process by calling
1362 * gfs2_dispose_glock_lru() above.
1365 static long gfs2_scan_glock_lru(int nr)
1367 struct gfs2_glock *gl;
1372 spin_lock(&lru_lock);
1373 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1374 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1376 /* Test for being demotable */
1377 if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
1378 list_move(&gl->gl_lru, &dispose);
1379 atomic_dec(&lru_count);
1384 list_move(&gl->gl_lru, &skipped);
1386 list_splice(&skipped, &lru_list);
1387 if (!list_empty(&dispose))
1388 gfs2_dispose_glock_lru(&dispose);
1389 spin_unlock(&lru_lock);
1394 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1395 struct shrink_control *sc)
1397 if (!(sc->gfp_mask & __GFP_FS))
1399 return gfs2_scan_glock_lru(sc->nr_to_scan);
1402 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1403 struct shrink_control *sc)
1405 return vfs_pressure_ratio(atomic_read(&lru_count));
1408 static struct shrinker glock_shrinker = {
1409 .seeks = DEFAULT_SEEKS,
1410 .count_objects = gfs2_glock_shrink_count,
1411 .scan_objects = gfs2_glock_shrink_scan,
1415 * examine_bucket - Call a function for glock in a hash bucket
1416 * @examiner: the function
1417 * @sdp: the filesystem
1418 * @bucket: the bucket
1422 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1424 struct gfs2_glock *gl;
1425 struct rhash_head *pos, *next;
1426 const struct bucket_table *tbl;
1430 tbl = rht_dereference_rcu(gl_hash_table.tbl, &gl_hash_table);
1431 for (i = 0; i < tbl->size; i++) {
1432 rht_for_each_entry_safe(gl, pos, next, tbl, i, gl_node) {
1433 if ((gl->gl_name.ln_sbd == sdp) &&
1434 lockref_get_not_dead(&gl->gl_lockref))
1443 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1444 * @gl: The glock to thaw
1448 static void thaw_glock(struct gfs2_glock *gl)
1450 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1452 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1453 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
1460 * clear_glock - look at a glock and see if we can free it from glock cache
1461 * @gl: the glock to look at
1465 static void clear_glock(struct gfs2_glock *gl)
1467 gfs2_glock_remove_from_lru(gl);
1469 spin_lock(&gl->gl_lockref.lock);
1470 if (gl->gl_state != LM_ST_UNLOCKED)
1471 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1472 spin_unlock(&gl->gl_lockref.lock);
1473 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1478 * gfs2_glock_thaw - Thaw any frozen glocks
1479 * @sdp: The super block
1483 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1485 glock_hash_walk(thaw_glock, sdp);
1488 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1490 spin_lock(&gl->gl_lockref.lock);
1491 gfs2_dump_glock(seq, gl);
1492 spin_unlock(&gl->gl_lockref.lock);
1495 static void dump_glock_func(struct gfs2_glock *gl)
1497 dump_glock(NULL, gl);
1501 * gfs2_gl_hash_clear - Empty out the glock hash table
1502 * @sdp: the filesystem
1503 * @wait: wait until it's all gone
1505 * Called when unmounting the filesystem.
1508 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1510 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1511 flush_workqueue(glock_workqueue);
1512 glock_hash_walk(clear_glock, sdp);
1513 flush_workqueue(glock_workqueue);
1514 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1515 glock_hash_walk(dump_glock_func, sdp);
1518 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1520 struct gfs2_glock *gl = ip->i_gl;
1523 ret = gfs2_truncatei_resume(ip);
1524 gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0);
1526 spin_lock(&gl->gl_lockref.lock);
1527 clear_bit(GLF_LOCK, &gl->gl_flags);
1529 spin_unlock(&gl->gl_lockref.lock);
1532 static const char *state2str(unsigned state)
1535 case LM_ST_UNLOCKED:
1539 case LM_ST_DEFERRED:
1541 case LM_ST_EXCLUSIVE:
1547 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1550 if (flags & LM_FLAG_TRY)
1552 if (flags & LM_FLAG_TRY_1CB)
1554 if (flags & LM_FLAG_NOEXP)
1556 if (flags & LM_FLAG_ANY)
1558 if (flags & LM_FLAG_PRIORITY)
1560 if (flags & GL_ASYNC)
1562 if (flags & GL_EXACT)
1564 if (flags & GL_NOCACHE)
1566 if (test_bit(HIF_HOLDER, &iflags))
1568 if (test_bit(HIF_WAIT, &iflags))
1570 if (test_bit(HIF_FIRST, &iflags))
1577 * dump_holder - print information about a glock holder
1578 * @seq: the seq_file struct
1579 * @gh: the glock holder
1583 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1585 struct task_struct *gh_owner = NULL;
1589 if (gh->gh_owner_pid)
1590 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1591 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1592 state2str(gh->gh_state),
1593 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1595 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1596 gh_owner ? gh_owner->comm : "(ended)",
1601 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1603 const unsigned long *gflags = &gl->gl_flags;
1606 if (test_bit(GLF_LOCK, gflags))
1608 if (test_bit(GLF_DEMOTE, gflags))
1610 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1612 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1614 if (test_bit(GLF_DIRTY, gflags))
1616 if (test_bit(GLF_LFLUSH, gflags))
1618 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1620 if (test_bit(GLF_REPLY_PENDING, gflags))
1622 if (test_bit(GLF_INITIAL, gflags))
1624 if (test_bit(GLF_FROZEN, gflags))
1626 if (test_bit(GLF_QUEUED, gflags))
1628 if (test_bit(GLF_LRU, gflags))
1632 if (test_bit(GLF_BLOCKING, gflags))
1639 * gfs2_dump_glock - print information about a glock
1640 * @seq: The seq_file struct
1643 * The file format is as follows:
1644 * One line per object, capital letters are used to indicate objects
1645 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1646 * other objects are indented by a single space and follow the glock to
1647 * which they are related. Fields are indicated by lower case letters
1648 * followed by a colon and the field value, except for strings which are in
1649 * [] so that its possible to see if they are composed of spaces for
1650 * example. The field's are n = number (id of the object), f = flags,
1651 * t = type, s = state, r = refcount, e = error, p = pid.
1655 void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1657 const struct gfs2_glock_operations *glops = gl->gl_ops;
1658 unsigned long long dtime;
1659 const struct gfs2_holder *gh;
1660 char gflags_buf[32];
1662 dtime = jiffies - gl->gl_demote_time;
1663 dtime *= 1000000/HZ; /* demote time in uSec */
1664 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1666 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",
1667 state2str(gl->gl_state),
1668 gl->gl_name.ln_type,
1669 (unsigned long long)gl->gl_name.ln_number,
1670 gflags2str(gflags_buf, gl),
1671 state2str(gl->gl_target),
1672 state2str(gl->gl_demote_state), dtime,
1673 atomic_read(&gl->gl_ail_count),
1674 atomic_read(&gl->gl_revokes),
1675 (int)gl->gl_lockref.count, gl->gl_hold_time);
1677 list_for_each_entry(gh, &gl->gl_holders, gh_list)
1678 dump_holder(seq, gh);
1680 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1681 glops->go_dump(seq, gl);
1684 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1686 struct gfs2_glock *gl = iter_ptr;
1688 seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
1689 gl->gl_name.ln_type,
1690 (unsigned long long)gl->gl_name.ln_number,
1691 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1692 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1693 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1694 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1695 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1696 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1697 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1698 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1702 static const char *gfs2_gltype[] = {
1716 static const char *gfs2_stype[] = {
1717 [GFS2_LKS_SRTT] = "srtt",
1718 [GFS2_LKS_SRTTVAR] = "srttvar",
1719 [GFS2_LKS_SRTTB] = "srttb",
1720 [GFS2_LKS_SRTTVARB] = "srttvarb",
1721 [GFS2_LKS_SIRT] = "sirt",
1722 [GFS2_LKS_SIRTVAR] = "sirtvar",
1723 [GFS2_LKS_DCOUNT] = "dlm",
1724 [GFS2_LKS_QCOUNT] = "queue",
1727 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1729 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1731 struct gfs2_sbd *sdp = seq->private;
1732 loff_t pos = *(loff_t *)iter_ptr;
1733 unsigned index = pos >> 3;
1734 unsigned subindex = pos & 0x07;
1737 if (index == 0 && subindex != 0)
1740 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1741 (index == 0) ? "cpu": gfs2_stype[subindex]);
1743 for_each_possible_cpu(i) {
1744 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1747 seq_printf(seq, " %15u", i);
1749 seq_printf(seq, " %15llu", (unsigned long long)lkstats->
1750 lkstats[index - 1].stats[subindex]);
1752 seq_putc(seq, '\n');
1756 int __init gfs2_glock_init(void)
1760 ret = rhashtable_init(&gl_hash_table, &ht_parms);
1764 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1765 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1766 if (!glock_workqueue) {
1767 rhashtable_destroy(&gl_hash_table);
1770 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1771 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1773 if (!gfs2_delete_workqueue) {
1774 destroy_workqueue(glock_workqueue);
1775 rhashtable_destroy(&gl_hash_table);
1779 register_shrinker(&glock_shrinker);
1784 void gfs2_glock_exit(void)
1786 unregister_shrinker(&glock_shrinker);
1787 rhashtable_destroy(&gl_hash_table);
1788 destroy_workqueue(glock_workqueue);
1789 destroy_workqueue(gfs2_delete_workqueue);
1792 static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1795 gi->gl = rhashtable_walk_next(&gi->hti);
1796 if (IS_ERR(gi->gl)) {
1797 if (PTR_ERR(gi->gl) == -EAGAIN)
1801 /* Skip entries for other sb and dead entries */
1802 } while ((gi->gl) && ((gi->sdp != gi->gl->gl_name.ln_sbd) ||
1803 __lockref_is_dead(&gi->gl->gl_lockref)));
1806 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1808 struct gfs2_glock_iter *gi = seq->private;
1812 if (gi->last_pos <= *pos)
1813 n = (*pos - gi->last_pos);
1815 ret = rhashtable_walk_start(&gi->hti);
1820 gfs2_glock_iter_next(gi);
1821 } while (gi->gl && n--);
1823 gi->last_pos = *pos;
1827 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1830 struct gfs2_glock_iter *gi = seq->private;
1833 gi->last_pos = *pos;
1834 gfs2_glock_iter_next(gi);
1838 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1840 struct gfs2_glock_iter *gi = seq->private;
1843 rhashtable_walk_stop(&gi->hti);
1846 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1848 dump_glock(seq, iter_ptr);
1852 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1855 if (*pos >= GFS2_NR_SBSTATS)
1860 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1864 if (*pos >= GFS2_NR_SBSTATS)
1869 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1874 static const struct seq_operations gfs2_glock_seq_ops = {
1875 .start = gfs2_glock_seq_start,
1876 .next = gfs2_glock_seq_next,
1877 .stop = gfs2_glock_seq_stop,
1878 .show = gfs2_glock_seq_show,
1881 static const struct seq_operations gfs2_glstats_seq_ops = {
1882 .start = gfs2_glock_seq_start,
1883 .next = gfs2_glock_seq_next,
1884 .stop = gfs2_glock_seq_stop,
1885 .show = gfs2_glstats_seq_show,
1888 static const struct seq_operations gfs2_sbstats_seq_ops = {
1889 .start = gfs2_sbstats_seq_start,
1890 .next = gfs2_sbstats_seq_next,
1891 .stop = gfs2_sbstats_seq_stop,
1892 .show = gfs2_sbstats_seq_show,
1895 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
1897 static int gfs2_glocks_open(struct inode *inode, struct file *file)
1899 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1900 sizeof(struct gfs2_glock_iter));
1902 struct seq_file *seq = file->private_data;
1903 struct gfs2_glock_iter *gi = seq->private;
1905 gi->sdp = inode->i_private;
1907 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
1909 seq->size = GFS2_SEQ_GOODSIZE;
1911 ret = rhashtable_walk_init(&gl_hash_table, &gi->hti);
1916 static int gfs2_glocks_release(struct inode *inode, struct file *file)
1918 struct seq_file *seq = file->private_data;
1919 struct gfs2_glock_iter *gi = seq->private;
1922 rhashtable_walk_exit(&gi->hti);
1923 return seq_release_private(inode, file);
1926 static int gfs2_glstats_open(struct inode *inode, struct file *file)
1928 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
1929 sizeof(struct gfs2_glock_iter));
1931 struct seq_file *seq = file->private_data;
1932 struct gfs2_glock_iter *gi = seq->private;
1933 gi->sdp = inode->i_private;
1935 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
1937 seq->size = GFS2_SEQ_GOODSIZE;
1939 ret = rhashtable_walk_init(&gl_hash_table, &gi->hti);
1944 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
1946 int ret = seq_open(file, &gfs2_sbstats_seq_ops);
1948 struct seq_file *seq = file->private_data;
1949 seq->private = inode->i_private; /* sdp */
1954 static const struct file_operations gfs2_glocks_fops = {
1955 .owner = THIS_MODULE,
1956 .open = gfs2_glocks_open,
1958 .llseek = seq_lseek,
1959 .release = gfs2_glocks_release,
1962 static const struct file_operations gfs2_glstats_fops = {
1963 .owner = THIS_MODULE,
1964 .open = gfs2_glstats_open,
1966 .llseek = seq_lseek,
1967 .release = gfs2_glocks_release,
1970 static const struct file_operations gfs2_sbstats_fops = {
1971 .owner = THIS_MODULE,
1972 .open = gfs2_sbstats_open,
1974 .llseek = seq_lseek,
1975 .release = seq_release,
1978 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1980 struct dentry *dent;
1982 dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1983 if (IS_ERR_OR_NULL(dent))
1985 sdp->debugfs_dir = dent;
1987 dent = debugfs_create_file("glocks",
1989 sdp->debugfs_dir, sdp,
1991 if (IS_ERR_OR_NULL(dent))
1993 sdp->debugfs_dentry_glocks = dent;
1995 dent = debugfs_create_file("glstats",
1997 sdp->debugfs_dir, sdp,
1998 &gfs2_glstats_fops);
1999 if (IS_ERR_OR_NULL(dent))
2001 sdp->debugfs_dentry_glstats = dent;
2003 dent = debugfs_create_file("sbstats",
2005 sdp->debugfs_dir, sdp,
2006 &gfs2_sbstats_fops);
2007 if (IS_ERR_OR_NULL(dent))
2009 sdp->debugfs_dentry_sbstats = dent;
2013 gfs2_delete_debugfs_file(sdp);
2014 return dent ? PTR_ERR(dent) : -ENOMEM;
2017 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2019 if (sdp->debugfs_dir) {
2020 if (sdp->debugfs_dentry_glocks) {
2021 debugfs_remove(sdp->debugfs_dentry_glocks);
2022 sdp->debugfs_dentry_glocks = NULL;
2024 if (sdp->debugfs_dentry_glstats) {
2025 debugfs_remove(sdp->debugfs_dentry_glstats);
2026 sdp->debugfs_dentry_glstats = NULL;
2028 if (sdp->debugfs_dentry_sbstats) {
2029 debugfs_remove(sdp->debugfs_dentry_sbstats);
2030 sdp->debugfs_dentry_sbstats = NULL;
2032 debugfs_remove(sdp->debugfs_dir);
2033 sdp->debugfs_dir = NULL;
2037 int gfs2_register_debugfs(void)
2039 gfs2_root = debugfs_create_dir("gfs2", NULL);
2040 if (IS_ERR(gfs2_root))
2041 return PTR_ERR(gfs2_root);
2042 return gfs2_root ? 0 : -ENOMEM;
2045 void gfs2_unregister_debugfs(void)
2047 debugfs_remove(gfs2_root);