1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/sched.h>
10 #include <linux/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/buffer_head.h>
13 #include <linux/delay.h>
14 #include <linux/sort.h>
15 #include <linux/hash.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/uaccess.h>
23 #include <linux/seq_file.h>
24 #include <linux/debugfs.h>
25 #include <linux/kthread.h>
26 #include <linux/freezer.h>
27 #include <linux/workqueue.h>
28 #include <linux/jiffies.h>
29 #include <linux/rcupdate.h>
30 #include <linux/rculist_bl.h>
31 #include <linux/bit_spinlock.h>
32 #include <linux/percpu.h>
33 #include <linux/list_sort.h>
34 #include <linux/lockref.h>
35 #include <linux/rhashtable.h>
48 #define CREATE_TRACE_POINTS
49 #include "trace_gfs2.h"
51 struct gfs2_glock_iter {
52 struct gfs2_sbd *sdp; /* incore superblock */
53 struct rhashtable_iter hti; /* rhashtable iterator */
54 struct gfs2_glock *gl; /* current glock struct */
55 loff_t last_pos; /* last position */
58 typedef void (*glock_examiner) (struct gfs2_glock * gl);
60 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
62 static struct dentry *gfs2_root;
63 static struct workqueue_struct *glock_workqueue;
64 struct workqueue_struct *gfs2_delete_workqueue;
65 static LIST_HEAD(lru_list);
66 static atomic_t lru_count = ATOMIC_INIT(0);
67 static DEFINE_SPINLOCK(lru_lock);
69 #define GFS2_GL_HASH_SHIFT 15
70 #define GFS2_GL_HASH_SIZE BIT(GFS2_GL_HASH_SHIFT)
72 static const struct rhashtable_params ht_parms = {
73 .nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4,
74 .key_len = offsetofend(struct lm_lockname, ln_type),
75 .key_offset = offsetof(struct gfs2_glock, gl_name),
76 .head_offset = offsetof(struct gfs2_glock, gl_node),
79 static struct rhashtable gl_hash_table;
81 #define GLOCK_WAIT_TABLE_BITS 12
82 #define GLOCK_WAIT_TABLE_SIZE (1 << GLOCK_WAIT_TABLE_BITS)
83 static wait_queue_head_t glock_wait_table[GLOCK_WAIT_TABLE_SIZE] __cacheline_aligned;
85 struct wait_glock_queue {
86 struct lm_lockname *name;
87 wait_queue_entry_t wait;
90 static int glock_wake_function(wait_queue_entry_t *wait, unsigned int mode,
93 struct wait_glock_queue *wait_glock =
94 container_of(wait, struct wait_glock_queue, wait);
95 struct lm_lockname *wait_name = wait_glock->name;
96 struct lm_lockname *wake_name = key;
98 if (wake_name->ln_sbd != wait_name->ln_sbd ||
99 wake_name->ln_number != wait_name->ln_number ||
100 wake_name->ln_type != wait_name->ln_type)
102 return autoremove_wake_function(wait, mode, sync, key);
105 static wait_queue_head_t *glock_waitqueue(struct lm_lockname *name)
107 u32 hash = jhash2((u32 *)name, ht_parms.key_len / 4, 0);
109 return glock_wait_table + hash_32(hash, GLOCK_WAIT_TABLE_BITS);
113 * wake_up_glock - Wake up waiters on a glock
116 static void wake_up_glock(struct gfs2_glock *gl)
118 wait_queue_head_t *wq = glock_waitqueue(&gl->gl_name);
120 if (waitqueue_active(wq))
121 __wake_up(wq, TASK_NORMAL, 1, &gl->gl_name);
124 static void gfs2_glock_dealloc(struct rcu_head *rcu)
126 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
128 kfree(gl->gl_lksb.sb_lvbptr);
129 if (gl->gl_ops->go_flags & GLOF_ASPACE)
130 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
132 kmem_cache_free(gfs2_glock_cachep, gl);
136 * glock_blocked_by_withdraw - determine if we can still use a glock
139 * We need to allow some glocks to be enqueued, dequeued, promoted, and demoted
140 * when we're withdrawn. For example, to maintain metadata integrity, we should
141 * disallow the use of inode and rgrp glocks when withdrawn. Other glocks, like
142 * iopen or the transaction glocks may be safely used because none of their
143 * metadata goes through the journal. So in general, we should disallow all
144 * glocks that are journaled, and allow all the others. One exception is:
145 * we need to allow our active journal to be promoted and demoted so others
146 * may recover it and we can reacquire it when they're done.
148 static bool glock_blocked_by_withdraw(struct gfs2_glock *gl)
150 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
152 if (likely(!gfs2_withdrawn(sdp)))
154 if (gl->gl_ops->go_flags & GLOF_NONDISK)
156 if (!sdp->sd_jdesc ||
157 gl->gl_name.ln_number == sdp->sd_jdesc->jd_no_addr)
162 void gfs2_glock_free(struct gfs2_glock *gl)
164 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
166 gfs2_glock_assert_withdraw(gl, atomic_read(&gl->gl_revokes) == 0);
167 rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms);
170 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
171 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
172 wake_up(&sdp->sd_glock_wait);
176 * gfs2_glock_hold() - increment reference count on glock
177 * @gl: The glock to hold
181 void gfs2_glock_hold(struct gfs2_glock *gl)
183 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
184 lockref_get(&gl->gl_lockref);
188 * demote_ok - Check to see if it's ok to unlock a glock
191 * Returns: 1 if it's ok
194 static int demote_ok(const struct gfs2_glock *gl)
196 const struct gfs2_glock_operations *glops = gl->gl_ops;
198 if (gl->gl_state == LM_ST_UNLOCKED)
200 if (!list_empty(&gl->gl_holders))
202 if (glops->go_demote_ok)
203 return glops->go_demote_ok(gl);
208 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
210 if (!(gl->gl_ops->go_flags & GLOF_LRU))
213 spin_lock(&lru_lock);
215 list_del(&gl->gl_lru);
216 list_add_tail(&gl->gl_lru, &lru_list);
218 if (!test_bit(GLF_LRU, &gl->gl_flags)) {
219 set_bit(GLF_LRU, &gl->gl_flags);
220 atomic_inc(&lru_count);
223 spin_unlock(&lru_lock);
226 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
228 if (!(gl->gl_ops->go_flags & GLOF_LRU))
231 spin_lock(&lru_lock);
232 if (test_bit(GLF_LRU, &gl->gl_flags)) {
233 list_del_init(&gl->gl_lru);
234 atomic_dec(&lru_count);
235 clear_bit(GLF_LRU, &gl->gl_flags);
237 spin_unlock(&lru_lock);
241 * Enqueue the glock on the work queue. Passes one glock reference on to the
244 static void __gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) {
245 if (!queue_delayed_work(glock_workqueue, &gl->gl_work, delay)) {
247 * We are holding the lockref spinlock, and the work was still
248 * queued above. The queued work (glock_work_func) takes that
249 * spinlock before dropping its glock reference(s), so it
250 * cannot have dropped them in the meantime.
252 GLOCK_BUG_ON(gl, gl->gl_lockref.count < 2);
253 gl->gl_lockref.count--;
257 static void gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) {
258 spin_lock(&gl->gl_lockref.lock);
259 __gfs2_glock_queue_work(gl, delay);
260 spin_unlock(&gl->gl_lockref.lock);
263 static void __gfs2_glock_put(struct gfs2_glock *gl)
265 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
266 struct address_space *mapping = gfs2_glock2aspace(gl);
268 lockref_mark_dead(&gl->gl_lockref);
270 gfs2_glock_remove_from_lru(gl);
271 spin_unlock(&gl->gl_lockref.lock);
272 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
273 GLOCK_BUG_ON(gl, mapping && mapping->nrpages && !gfs2_withdrawn(sdp));
274 trace_gfs2_glock_put(gl);
275 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
279 * Cause the glock to be put in work queue context.
281 void gfs2_glock_queue_put(struct gfs2_glock *gl)
283 gfs2_glock_queue_work(gl, 0);
287 * gfs2_glock_put() - Decrement reference count on glock
288 * @gl: The glock to put
292 void gfs2_glock_put(struct gfs2_glock *gl)
294 if (lockref_put_or_lock(&gl->gl_lockref))
297 __gfs2_glock_put(gl);
301 * may_grant - check if its ok to grant a new lock
303 * @gh: The lock request which we wish to grant
305 * Returns: true if its ok to grant the lock
308 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
310 const struct gfs2_holder *gh_head = list_first_entry(&gl->gl_holders, const struct gfs2_holder, gh_list);
311 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
312 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
314 if (gl->gl_state == gh->gh_state)
316 if (gh->gh_flags & GL_EXACT)
318 if (gl->gl_state == LM_ST_EXCLUSIVE) {
319 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
321 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
324 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
329 static void gfs2_holder_wake(struct gfs2_holder *gh)
331 clear_bit(HIF_WAIT, &gh->gh_iflags);
332 smp_mb__after_atomic();
333 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
334 if (gh->gh_flags & GL_ASYNC) {
335 struct gfs2_sbd *sdp = gh->gh_gl->gl_name.ln_sbd;
337 wake_up(&sdp->sd_async_glock_wait);
342 * do_error - Something unexpected has happened during a lock request
346 static void do_error(struct gfs2_glock *gl, const int ret)
348 struct gfs2_holder *gh, *tmp;
350 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
351 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
353 if (ret & LM_OUT_ERROR)
355 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
356 gh->gh_error = GLR_TRYFAILED;
359 list_del_init(&gh->gh_list);
360 trace_gfs2_glock_queue(gh, 0);
361 gfs2_holder_wake(gh);
366 * do_promote - promote as many requests as possible on the current queue
369 * Returns: 1 if there is a blocked holder at the head of the list, or 2
370 * if a type specific operation is underway.
373 static int do_promote(struct gfs2_glock *gl)
374 __releases(&gl->gl_lockref.lock)
375 __acquires(&gl->gl_lockref.lock)
377 const struct gfs2_glock_operations *glops = gl->gl_ops;
378 struct gfs2_holder *gh, *tmp;
382 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
383 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
385 if (may_grant(gl, gh)) {
386 if (gh->gh_list.prev == &gl->gl_holders &&
388 spin_unlock(&gl->gl_lockref.lock);
389 /* FIXME: eliminate this eventually */
390 ret = glops->go_lock(gh);
391 spin_lock(&gl->gl_lockref.lock);
396 list_del_init(&gh->gh_list);
397 trace_gfs2_glock_queue(gh, 0);
398 gfs2_holder_wake(gh);
401 set_bit(HIF_HOLDER, &gh->gh_iflags);
402 trace_gfs2_promote(gh, 1);
403 gfs2_holder_wake(gh);
406 set_bit(HIF_HOLDER, &gh->gh_iflags);
407 trace_gfs2_promote(gh, 0);
408 gfs2_holder_wake(gh);
411 if (gh->gh_list.prev == &gl->gl_holders)
420 * find_first_waiter - find the first gh that's waiting for the glock
424 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
426 struct gfs2_holder *gh;
428 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
429 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
436 * state_change - record that the glock is now in a different state
438 * @new_state the new state
442 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
446 held1 = (gl->gl_state != LM_ST_UNLOCKED);
447 held2 = (new_state != LM_ST_UNLOCKED);
449 if (held1 != held2) {
450 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
452 gl->gl_lockref.count++;
454 gl->gl_lockref.count--;
456 if (held1 && held2 && list_empty(&gl->gl_holders))
457 clear_bit(GLF_QUEUED, &gl->gl_flags);
459 if (new_state != gl->gl_target)
460 /* shorten our minimum hold time */
461 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
463 gl->gl_state = new_state;
464 gl->gl_tchange = jiffies;
467 static void gfs2_set_demote(struct gfs2_glock *gl)
469 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
471 set_bit(GLF_DEMOTE, &gl->gl_flags);
473 wake_up(&sdp->sd_async_glock_wait);
476 static void gfs2_demote_wake(struct gfs2_glock *gl)
478 gl->gl_demote_state = LM_ST_EXCLUSIVE;
479 clear_bit(GLF_DEMOTE, &gl->gl_flags);
480 smp_mb__after_atomic();
481 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
485 * finish_xmote - The DLM has replied to one of our lock requests
487 * @ret: The status from the DLM
491 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
493 const struct gfs2_glock_operations *glops = gl->gl_ops;
494 struct gfs2_holder *gh;
495 unsigned state = ret & LM_OUT_ST_MASK;
498 spin_lock(&gl->gl_lockref.lock);
499 trace_gfs2_glock_state_change(gl, state);
500 state_change(gl, state);
501 gh = find_first_waiter(gl);
503 /* Demote to UN request arrived during demote to SH or DF */
504 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
505 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
506 gl->gl_target = LM_ST_UNLOCKED;
508 /* Check for state != intended state */
509 if (unlikely(state != gl->gl_target)) {
510 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
511 /* move to back of queue and try next entry */
512 if (ret & LM_OUT_CANCELED) {
513 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
514 list_move_tail(&gh->gh_list, &gl->gl_holders);
515 gh = find_first_waiter(gl);
516 gl->gl_target = gh->gh_state;
519 /* Some error or failed "try lock" - report it */
520 if ((ret & LM_OUT_ERROR) ||
521 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
522 gl->gl_target = gl->gl_state;
528 /* Unlocked due to conversion deadlock, try again */
531 do_xmote(gl, gh, gl->gl_target);
533 /* Conversion fails, unlock and try again */
536 do_xmote(gl, gh, LM_ST_UNLOCKED);
538 default: /* Everything else */
539 fs_err(gl->gl_name.ln_sbd, "wanted %u got %u\n",
540 gl->gl_target, state);
543 spin_unlock(&gl->gl_lockref.lock);
547 /* Fast path - we got what we asked for */
548 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
549 gfs2_demote_wake(gl);
550 if (state != LM_ST_UNLOCKED) {
551 if (glops->go_xmote_bh) {
552 spin_unlock(&gl->gl_lockref.lock);
553 rv = glops->go_xmote_bh(gl, gh);
554 spin_lock(&gl->gl_lockref.lock);
565 clear_bit(GLF_LOCK, &gl->gl_flags);
567 spin_unlock(&gl->gl_lockref.lock);
571 * do_xmote - Calls the DLM to change the state of a lock
572 * @gl: The lock state
573 * @gh: The holder (only for promotes)
574 * @target: The target lock state
578 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
579 __releases(&gl->gl_lockref.lock)
580 __acquires(&gl->gl_lockref.lock)
582 const struct gfs2_glock_operations *glops = gl->gl_ops;
583 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
584 unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0);
587 if (target != LM_ST_UNLOCKED && glock_blocked_by_withdraw(gl) &&
588 gh && !(gh->gh_flags & LM_FLAG_NOEXP))
590 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
592 GLOCK_BUG_ON(gl, gl->gl_state == target);
593 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
594 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
597 * If another process is already doing the invalidate, let that
598 * finish first. The glock state machine will get back to this
599 * holder again later.
601 if (test_and_set_bit(GLF_INVALIDATE_IN_PROGRESS,
604 do_error(gl, 0); /* Fail queued try locks */
607 set_bit(GLF_BLOCKING, &gl->gl_flags);
608 if ((gl->gl_req == LM_ST_UNLOCKED) ||
609 (gl->gl_state == LM_ST_EXCLUSIVE) ||
610 (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
611 clear_bit(GLF_BLOCKING, &gl->gl_flags);
612 spin_unlock(&gl->gl_lockref.lock);
613 if (glops->go_sync) {
614 ret = glops->go_sync(gl);
615 /* If we had a problem syncing (due to io errors or whatever,
616 * we should not invalidate the metadata or tell dlm to
617 * release the glock to other nodes.
620 if (cmpxchg(&sdp->sd_log_error, 0, ret)) {
621 fs_err(sdp, "Error %d syncing glock \n", ret);
622 gfs2_dump_glock(NULL, gl, true);
627 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) {
629 * The call to go_sync should have cleared out the ail list.
630 * If there are still items, we have a problem. We ought to
631 * withdraw, but we can't because the withdraw code also uses
632 * glocks. Warn about the error, dump the glock, then fall
633 * through and wait for logd to do the withdraw for us.
635 if ((atomic_read(&gl->gl_ail_count) != 0) &&
636 (!cmpxchg(&sdp->sd_log_error, 0, -EIO))) {
637 gfs2_glock_assert_warn(gl,
638 !atomic_read(&gl->gl_ail_count));
639 gfs2_dump_glock(NULL, gl, true);
641 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
642 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
648 * Check for an error encountered since we called go_sync and go_inval.
649 * If so, we can't withdraw from the glock code because the withdraw
650 * code itself uses glocks (see function signal_our_withdraw) to
651 * change the mount to read-only. Most importantly, we must not call
652 * dlm to unlock the glock until the journal is in a known good state
653 * (after journal replay) otherwise other nodes may use the object
654 * (rgrp or dinode) and then later, journal replay will corrupt the
655 * file system. The best we can do here is wait for the logd daemon
656 * to see sd_log_error and withdraw, and in the meantime, requeue the
659 * However, if we're just unlocking the lock (say, for unmount, when
660 * gfs2_gl_hash_clear calls clear_glock) and recovery is complete
661 * then it's okay to tell dlm to unlock it.
663 if (unlikely(sdp->sd_log_error && !gfs2_withdrawn(sdp)))
664 gfs2_withdraw_delayed(sdp);
665 if (glock_blocked_by_withdraw(gl)) {
666 if (target != LM_ST_UNLOCKED ||
667 test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags)) {
668 gfs2_glock_queue_work(gl, GL_GLOCK_DFT_HOLD);
673 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
675 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
676 if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED &&
677 target == LM_ST_UNLOCKED &&
678 test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) {
679 finish_xmote(gl, target);
680 gfs2_glock_queue_work(gl, 0);
682 fs_err(sdp, "lm_lock ret %d\n", ret);
683 GLOCK_BUG_ON(gl, !gfs2_withdrawn(sdp));
685 } else { /* lock_nolock */
686 finish_xmote(gl, target);
687 gfs2_glock_queue_work(gl, 0);
690 spin_lock(&gl->gl_lockref.lock);
694 * find_first_holder - find the first "holder" gh
698 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
700 struct gfs2_holder *gh;
702 if (!list_empty(&gl->gl_holders)) {
703 gh = list_first_entry(&gl->gl_holders, struct gfs2_holder, gh_list);
704 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
711 * run_queue - do all outstanding tasks related to a glock
712 * @gl: The glock in question
713 * @nonblock: True if we must not block in run_queue
717 static void run_queue(struct gfs2_glock *gl, const int nonblock)
718 __releases(&gl->gl_lockref.lock)
719 __acquires(&gl->gl_lockref.lock)
721 struct gfs2_holder *gh = NULL;
724 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
727 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
729 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
730 gl->gl_demote_state != gl->gl_state) {
731 if (find_first_holder(gl))
735 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
736 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
737 gl->gl_target = gl->gl_demote_state;
739 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
740 gfs2_demote_wake(gl);
741 ret = do_promote(gl);
746 gh = find_first_waiter(gl);
747 gl->gl_target = gh->gh_state;
748 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
749 do_error(gl, 0); /* Fail queued try locks */
751 do_xmote(gl, gh, gl->gl_target);
756 clear_bit(GLF_LOCK, &gl->gl_flags);
757 smp_mb__after_atomic();
758 gl->gl_lockref.count++;
759 __gfs2_glock_queue_work(gl, 0);
763 clear_bit(GLF_LOCK, &gl->gl_flags);
764 smp_mb__after_atomic();
768 void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation)
770 struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
772 if (ri->ri_magic == 0)
773 ri->ri_magic = cpu_to_be32(GFS2_MAGIC);
774 if (ri->ri_magic == cpu_to_be32(GFS2_MAGIC))
775 ri->ri_generation_deleted = cpu_to_be64(generation);
778 bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation)
780 struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
782 if (ri->ri_magic != cpu_to_be32(GFS2_MAGIC))
784 return generation <= be64_to_cpu(ri->ri_generation_deleted);
787 static void gfs2_glock_poke(struct gfs2_glock *gl)
789 int flags = LM_FLAG_TRY_1CB | LM_FLAG_ANY | GL_SKIP;
790 struct gfs2_holder gh;
793 gfs2_holder_init(gl, LM_ST_SHARED, flags, &gh);
794 error = gfs2_glock_nq(&gh);
797 gfs2_holder_uninit(&gh);
800 static bool gfs2_try_evict(struct gfs2_glock *gl)
802 struct gfs2_inode *ip;
803 bool evicted = false;
806 * If there is contention on the iopen glock and we have an inode, try
807 * to grab and release the inode so that it can be evicted. This will
808 * allow the remote node to go ahead and delete the inode without us
809 * having to do it, which will avoid rgrp glock thrashing.
811 * The remote node is likely still holding the corresponding inode
812 * glock, so it will run before we get to verify that the delete has
815 spin_lock(&gl->gl_lockref.lock);
817 if (ip && !igrab(&ip->i_inode))
819 spin_unlock(&gl->gl_lockref.lock);
821 struct gfs2_glock *inode_gl = NULL;
823 gl->gl_no_formal_ino = ip->i_no_formal_ino;
824 set_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
825 d_prune_aliases(&ip->i_inode);
828 /* If the inode was evicted, gl->gl_object will now be NULL. */
829 spin_lock(&gl->gl_lockref.lock);
833 lockref_get(&inode_gl->gl_lockref);
834 clear_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
836 spin_unlock(&gl->gl_lockref.lock);
838 gfs2_glock_poke(inode_gl);
839 gfs2_glock_put(inode_gl);
846 static void delete_work_func(struct work_struct *work)
848 struct delayed_work *dwork = to_delayed_work(work);
849 struct gfs2_glock *gl = container_of(dwork, struct gfs2_glock, gl_delete);
850 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
852 u64 no_addr = gl->gl_name.ln_number;
854 spin_lock(&gl->gl_lockref.lock);
855 clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
856 spin_unlock(&gl->gl_lockref.lock);
858 /* If someone's using this glock to create a new dinode, the block must
859 have been freed by another node, then re-used, in which case our
860 iopen callback is too late after the fact. Ignore it. */
861 if (test_bit(GLF_INODE_CREATING, &gl->gl_flags))
864 if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
866 * If we can evict the inode, give the remote node trying to
867 * delete the inode some time before verifying that the delete
868 * has happened. Otherwise, if we cause contention on the inode glock
869 * immediately, the remote node will think that we still have
870 * the inode in use, and so it will give up waiting.
872 * If we can't evict the inode, signal to the remote node that
873 * the inode is still in use. We'll later try to delete the
874 * inode locally in gfs2_evict_inode.
876 * FIXME: We only need to verify that the remote node has
877 * deleted the inode because nodes before this remote delete
878 * rework won't cooperate. At a later time, when we no longer
879 * care about compatibility with such nodes, we can skip this
882 if (gfs2_try_evict(gl)) {
883 if (gfs2_queue_delete_work(gl, 5 * HZ))
889 inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino,
890 GFS2_BLKST_UNLINKED);
891 if (!IS_ERR_OR_NULL(inode)) {
892 d_prune_aliases(inode);
899 static void glock_work_func(struct work_struct *work)
901 unsigned long delay = 0;
902 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
903 unsigned int drop_refs = 1;
905 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
906 finish_xmote(gl, gl->gl_reply);
909 spin_lock(&gl->gl_lockref.lock);
910 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
911 gl->gl_state != LM_ST_UNLOCKED &&
912 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
913 unsigned long holdtime, now = jiffies;
915 holdtime = gl->gl_tchange + gl->gl_hold_time;
916 if (time_before(now, holdtime))
917 delay = holdtime - now;
920 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
926 /* Keep one glock reference for the work we requeue. */
928 if (gl->gl_name.ln_type != LM_TYPE_INODE)
930 __gfs2_glock_queue_work(gl, delay);
934 * Drop the remaining glock references manually here. (Mind that
935 * __gfs2_glock_queue_work depends on the lockref spinlock begin held
938 gl->gl_lockref.count -= drop_refs;
939 if (!gl->gl_lockref.count) {
940 __gfs2_glock_put(gl);
943 spin_unlock(&gl->gl_lockref.lock);
946 static struct gfs2_glock *find_insert_glock(struct lm_lockname *name,
947 struct gfs2_glock *new)
949 struct wait_glock_queue wait;
950 wait_queue_head_t *wq = glock_waitqueue(name);
951 struct gfs2_glock *gl;
954 init_wait(&wait.wait);
955 wait.wait.func = glock_wake_function;
958 prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
961 gl = rhashtable_lookup_get_insert_fast(&gl_hash_table,
962 &new->gl_node, ht_parms);
966 gl = rhashtable_lookup_fast(&gl_hash_table,
969 if (gl && !lockref_get_not_dead(&gl->gl_lockref)) {
976 finish_wait(wq, &wait.wait);
981 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
982 * @sdp: The GFS2 superblock
983 * @number: the lock number
984 * @glops: The glock_operations to use
985 * @create: If 0, don't create the glock if it doesn't exist
986 * @glp: the glock is returned here
988 * This does not lock a glock, just finds/creates structures for one.
993 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
994 const struct gfs2_glock_operations *glops, int create,
995 struct gfs2_glock **glp)
997 struct super_block *s = sdp->sd_vfs;
998 struct lm_lockname name = { .ln_number = number,
999 .ln_type = glops->go_type,
1001 struct gfs2_glock *gl, *tmp;
1002 struct address_space *mapping;
1003 struct kmem_cache *cachep;
1006 gl = find_insert_glock(&name, NULL);
1014 if (glops->go_flags & GLOF_ASPACE)
1015 cachep = gfs2_glock_aspace_cachep;
1017 cachep = gfs2_glock_cachep;
1018 gl = kmem_cache_alloc(cachep, GFP_NOFS);
1022 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
1024 if (glops->go_flags & GLOF_LVB) {
1025 gl->gl_lksb.sb_lvbptr = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
1026 if (!gl->gl_lksb.sb_lvbptr) {
1027 kmem_cache_free(cachep, gl);
1032 atomic_inc(&sdp->sd_glock_disposal);
1033 gl->gl_node.next = NULL;
1036 gl->gl_lockref.count = 1;
1037 gl->gl_state = LM_ST_UNLOCKED;
1038 gl->gl_target = LM_ST_UNLOCKED;
1039 gl->gl_demote_state = LM_ST_EXCLUSIVE;
1043 /* We use the global stats to estimate the initial per-glock stats */
1044 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
1046 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
1047 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
1048 gl->gl_tchange = jiffies;
1049 gl->gl_object = NULL;
1050 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
1051 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
1052 INIT_DELAYED_WORK(&gl->gl_delete, delete_work_func);
1054 mapping = gfs2_glock2aspace(gl);
1056 mapping->a_ops = &gfs2_meta_aops;
1057 mapping->host = s->s_bdev->bd_inode;
1059 mapping_set_gfp_mask(mapping, GFP_NOFS);
1060 mapping->private_data = NULL;
1061 mapping->writeback_index = 0;
1064 tmp = find_insert_glock(&name, gl);
1076 kfree(gl->gl_lksb.sb_lvbptr);
1077 kmem_cache_free(cachep, gl);
1078 atomic_dec(&sdp->sd_glock_disposal);
1085 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
1087 * @state: the state we're requesting
1088 * @flags: the modifier flags
1089 * @gh: the holder structure
1093 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags,
1094 struct gfs2_holder *gh)
1096 INIT_LIST_HEAD(&gh->gh_list);
1098 gh->gh_ip = _RET_IP_;
1099 gh->gh_owner_pid = get_pid(task_pid(current));
1100 gh->gh_state = state;
1101 gh->gh_flags = flags;
1104 gfs2_glock_hold(gl);
1108 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
1109 * @state: the state we're requesting
1110 * @flags: the modifier flags
1111 * @gh: the holder structure
1113 * Don't mess with the glock.
1117 void gfs2_holder_reinit(unsigned int state, u16 flags, struct gfs2_holder *gh)
1119 gh->gh_state = state;
1120 gh->gh_flags = flags;
1122 gh->gh_ip = _RET_IP_;
1123 put_pid(gh->gh_owner_pid);
1124 gh->gh_owner_pid = get_pid(task_pid(current));
1128 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
1129 * @gh: the holder structure
1133 void gfs2_holder_uninit(struct gfs2_holder *gh)
1135 put_pid(gh->gh_owner_pid);
1136 gfs2_glock_put(gh->gh_gl);
1137 gfs2_holder_mark_uninitialized(gh);
1141 static void gfs2_glock_update_hold_time(struct gfs2_glock *gl,
1142 unsigned long start_time)
1144 /* Have we waited longer that a second? */
1145 if (time_after(jiffies, start_time + HZ)) {
1146 /* Lengthen the minimum hold time. */
1147 gl->gl_hold_time = min(gl->gl_hold_time + GL_GLOCK_HOLD_INCR,
1153 * gfs2_glock_wait - wait on a glock acquisition
1154 * @gh: the glock holder
1156 * Returns: 0 on success
1159 int gfs2_glock_wait(struct gfs2_holder *gh)
1161 unsigned long start_time = jiffies;
1164 wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
1165 gfs2_glock_update_hold_time(gh->gh_gl, start_time);
1166 return gh->gh_error;
1169 static int glocks_pending(unsigned int num_gh, struct gfs2_holder *ghs)
1173 for (i = 0; i < num_gh; i++)
1174 if (test_bit(HIF_WAIT, &ghs[i].gh_iflags))
1180 * gfs2_glock_async_wait - wait on multiple asynchronous glock acquisitions
1181 * @num_gh: the number of holders in the array
1182 * @ghs: the glock holder array
1184 * Returns: 0 on success, meaning all glocks have been granted and are held.
1185 * -ESTALE if the request timed out, meaning all glocks were released,
1186 * and the caller should retry the operation.
1189 int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs)
1191 struct gfs2_sbd *sdp = ghs[0].gh_gl->gl_name.ln_sbd;
1192 int i, ret = 0, timeout = 0;
1193 unsigned long start_time = jiffies;
1198 * Total up the (minimum hold time * 2) of all glocks and use that to
1199 * determine the max amount of time we should wait.
1201 for (i = 0; i < num_gh; i++)
1202 timeout += ghs[i].gh_gl->gl_hold_time << 1;
1205 if (!wait_event_timeout(sdp->sd_async_glock_wait,
1206 !glocks_pending(num_gh, ghs), timeout))
1207 ret = -ESTALE; /* request timed out. */
1210 * If dlm granted all our requests, we need to adjust the glock
1211 * minimum hold time values according to how long we waited.
1213 * If our request timed out, we need to repeatedly release any held
1214 * glocks we acquired thus far to allow dlm to acquire the remaining
1215 * glocks without deadlocking. We cannot currently cancel outstanding
1216 * glock acquisitions.
1218 * The HIF_WAIT bit tells us which requests still need a response from
1221 * If dlm sent us any errors, we return the first error we find.
1223 keep_waiting = false;
1224 for (i = 0; i < num_gh; i++) {
1225 /* Skip holders we have already dequeued below. */
1226 if (!gfs2_holder_queued(&ghs[i]))
1228 /* Skip holders with a pending DLM response. */
1229 if (test_bit(HIF_WAIT, &ghs[i].gh_iflags)) {
1230 keep_waiting = true;
1234 if (test_bit(HIF_HOLDER, &ghs[i].gh_iflags)) {
1236 gfs2_glock_dq(&ghs[i]);
1238 gfs2_glock_update_hold_time(ghs[i].gh_gl,
1242 ret = ghs[i].gh_error;
1249 * At this point, we've either acquired all locks or released them all.
1255 * handle_callback - process a demote request
1257 * @state: the state the caller wants us to change to
1259 * There are only two requests that we are going to see in actual
1260 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
1263 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
1264 unsigned long delay, bool remote)
1267 set_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
1269 gfs2_set_demote(gl);
1270 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
1271 gl->gl_demote_state = state;
1272 gl->gl_demote_time = jiffies;
1273 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
1274 gl->gl_demote_state != state) {
1275 gl->gl_demote_state = LM_ST_UNLOCKED;
1277 if (gl->gl_ops->go_callback)
1278 gl->gl_ops->go_callback(gl, remote);
1279 trace_gfs2_demote_rq(gl, remote);
1282 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
1284 struct va_format vaf;
1287 va_start(args, fmt);
1290 seq_vprintf(seq, fmt, args);
1295 pr_err("%pV", &vaf);
1302 * add_to_queue - Add a holder to the wait queue (but look for recursion)
1303 * @gh: the holder structure to add
1305 * Eventually we should move the recursive locking trap to a
1306 * debugging option or something like that. This is the fast
1307 * path and needs to have the minimum number of distractions.
1311 static inline void add_to_queue(struct gfs2_holder *gh)
1312 __releases(&gl->gl_lockref.lock)
1313 __acquires(&gl->gl_lockref.lock)
1315 struct gfs2_glock *gl = gh->gh_gl;
1316 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
1317 struct list_head *insert_pt = NULL;
1318 struct gfs2_holder *gh2;
1321 GLOCK_BUG_ON(gl, gh->gh_owner_pid == NULL);
1322 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
1323 GLOCK_BUG_ON(gl, true);
1325 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
1326 if (test_bit(GLF_LOCK, &gl->gl_flags))
1327 try_futile = !may_grant(gl, gh);
1328 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
1332 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
1333 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
1334 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
1335 goto trap_recursive;
1337 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
1339 gh->gh_error = GLR_TRYFAILED;
1340 gfs2_holder_wake(gh);
1343 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
1345 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
1346 insert_pt = &gh2->gh_list;
1348 set_bit(GLF_QUEUED, &gl->gl_flags);
1349 trace_gfs2_glock_queue(gh, 1);
1350 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
1351 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
1352 if (likely(insert_pt == NULL)) {
1353 list_add_tail(&gh->gh_list, &gl->gl_holders);
1354 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1358 list_add_tail(&gh->gh_list, insert_pt);
1360 gh = list_first_entry(&gl->gl_holders, struct gfs2_holder, gh_list);
1361 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1362 spin_unlock(&gl->gl_lockref.lock);
1363 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1364 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1365 spin_lock(&gl->gl_lockref.lock);
1370 fs_err(sdp, "original: %pSR\n", (void *)gh2->gh_ip);
1371 fs_err(sdp, "pid: %d\n", pid_nr(gh2->gh_owner_pid));
1372 fs_err(sdp, "lock type: %d req lock state : %d\n",
1373 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1374 fs_err(sdp, "new: %pSR\n", (void *)gh->gh_ip);
1375 fs_err(sdp, "pid: %d\n", pid_nr(gh->gh_owner_pid));
1376 fs_err(sdp, "lock type: %d req lock state : %d\n",
1377 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1378 gfs2_dump_glock(NULL, gl, true);
1383 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1384 * @gh: the holder structure
1386 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1388 * Returns: 0, GLR_TRYFAILED, or errno on failure
1391 int gfs2_glock_nq(struct gfs2_holder *gh)
1393 struct gfs2_glock *gl = gh->gh_gl;
1396 if (glock_blocked_by_withdraw(gl) && !(gh->gh_flags & LM_FLAG_NOEXP))
1399 if (test_bit(GLF_LRU, &gl->gl_flags))
1400 gfs2_glock_remove_from_lru(gl);
1402 spin_lock(&gl->gl_lockref.lock);
1404 if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
1405 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
1406 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1407 gl->gl_lockref.count++;
1408 __gfs2_glock_queue_work(gl, 0);
1411 spin_unlock(&gl->gl_lockref.lock);
1413 if (!(gh->gh_flags & GL_ASYNC))
1414 error = gfs2_glock_wait(gh);
1420 * gfs2_glock_poll - poll to see if an async request has been completed
1423 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1426 int gfs2_glock_poll(struct gfs2_holder *gh)
1428 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1432 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1433 * @gh: the glock holder
1437 void gfs2_glock_dq(struct gfs2_holder *gh)
1439 struct gfs2_glock *gl = gh->gh_gl;
1440 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
1444 spin_lock(&gl->gl_lockref.lock);
1446 * If we're in the process of file system withdraw, we cannot just
1447 * dequeue any glocks until our journal is recovered, lest we
1448 * introduce file system corruption. We need two exceptions to this
1449 * rule: We need to allow unlocking of nondisk glocks and the glock
1450 * for our own journal that needs recovery.
1452 if (test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags) &&
1453 glock_blocked_by_withdraw(gl) &&
1454 gh->gh_gl != sdp->sd_jinode_gl) {
1455 sdp->sd_glock_dqs_held++;
1457 wait_on_bit(&sdp->sd_flags, SDF_WITHDRAW_RECOVERY,
1458 TASK_UNINTERRUPTIBLE);
1460 if (gh->gh_flags & GL_NOCACHE)
1461 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1463 list_del_init(&gh->gh_list);
1464 clear_bit(HIF_HOLDER, &gh->gh_iflags);
1465 if (find_first_holder(gl) == NULL) {
1466 if (list_empty(&gl->gl_holders) &&
1467 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1468 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1471 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
1472 gfs2_glock_add_to_lru(gl);
1474 trace_gfs2_glock_queue(gh, 0);
1475 if (unlikely(!fast_path)) {
1476 gl->gl_lockref.count++;
1477 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1478 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1479 gl->gl_name.ln_type == LM_TYPE_INODE)
1480 delay = gl->gl_hold_time;
1481 __gfs2_glock_queue_work(gl, delay);
1483 spin_unlock(&gl->gl_lockref.lock);
1486 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1488 struct gfs2_glock *gl = gh->gh_gl;
1491 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
1495 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1496 * @gh: the holder structure
1500 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1503 gfs2_holder_uninit(gh);
1507 * gfs2_glock_nq_num - acquire a glock based on lock number
1508 * @sdp: the filesystem
1509 * @number: the lock number
1510 * @glops: the glock operations for the type of glock
1511 * @state: the state to acquire the glock in
1512 * @flags: modifier flags for the acquisition
1513 * @gh: the struct gfs2_holder
1518 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1519 const struct gfs2_glock_operations *glops,
1520 unsigned int state, u16 flags, struct gfs2_holder *gh)
1522 struct gfs2_glock *gl;
1525 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1527 error = gfs2_glock_nq_init(gl, state, flags, gh);
1535 * glock_compare - Compare two struct gfs2_glock structures for sorting
1536 * @arg_a: the first structure
1537 * @arg_b: the second structure
1541 static int glock_compare(const void *arg_a, const void *arg_b)
1543 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1544 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1545 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1546 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1548 if (a->ln_number > b->ln_number)
1550 if (a->ln_number < b->ln_number)
1552 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1557 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1558 * @num_gh: the number of structures
1559 * @ghs: an array of struct gfs2_holder structures
1561 * Returns: 0 on success (all glocks acquired),
1562 * errno on failure (no glocks acquired)
1565 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1566 struct gfs2_holder **p)
1571 for (x = 0; x < num_gh; x++)
1574 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1576 for (x = 0; x < num_gh; x++) {
1577 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1579 error = gfs2_glock_nq(p[x]);
1582 gfs2_glock_dq(p[x]);
1591 * gfs2_glock_nq_m - acquire multiple glocks
1592 * @num_gh: the number of structures
1593 * @ghs: an array of struct gfs2_holder structures
1596 * Returns: 0 on success (all glocks acquired),
1597 * errno on failure (no glocks acquired)
1600 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1602 struct gfs2_holder *tmp[4];
1603 struct gfs2_holder **pph = tmp;
1610 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1611 return gfs2_glock_nq(ghs);
1615 pph = kmalloc_array(num_gh, sizeof(struct gfs2_holder *),
1621 error = nq_m_sync(num_gh, ghs, pph);
1630 * gfs2_glock_dq_m - release multiple glocks
1631 * @num_gh: the number of structures
1632 * @ghs: an array of struct gfs2_holder structures
1636 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1639 gfs2_glock_dq(&ghs[num_gh]);
1642 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1644 unsigned long delay = 0;
1645 unsigned long holdtime;
1646 unsigned long now = jiffies;
1648 gfs2_glock_hold(gl);
1649 holdtime = gl->gl_tchange + gl->gl_hold_time;
1650 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1651 gl->gl_name.ln_type == LM_TYPE_INODE) {
1652 if (time_before(now, holdtime))
1653 delay = holdtime - now;
1654 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1655 delay = gl->gl_hold_time;
1658 spin_lock(&gl->gl_lockref.lock);
1659 handle_callback(gl, state, delay, true);
1660 __gfs2_glock_queue_work(gl, delay);
1661 spin_unlock(&gl->gl_lockref.lock);
1665 * gfs2_should_freeze - Figure out if glock should be frozen
1666 * @gl: The glock in question
1668 * Glocks are not frozen if (a) the result of the dlm operation is
1669 * an error, (b) the locking operation was an unlock operation or
1670 * (c) if there is a "noexp" flagged request anywhere in the queue
1672 * Returns: 1 if freezing should occur, 0 otherwise
1675 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1677 const struct gfs2_holder *gh;
1679 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1681 if (gl->gl_target == LM_ST_UNLOCKED)
1684 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1685 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1687 if (LM_FLAG_NOEXP & gh->gh_flags)
1695 * gfs2_glock_complete - Callback used by locking
1696 * @gl: Pointer to the glock
1697 * @ret: The return value from the dlm
1699 * The gl_reply field is under the gl_lockref.lock lock so that it is ok
1700 * to use a bitfield shared with other glock state fields.
1703 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1705 struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
1707 spin_lock(&gl->gl_lockref.lock);
1710 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1711 if (gfs2_should_freeze(gl)) {
1712 set_bit(GLF_FROZEN, &gl->gl_flags);
1713 spin_unlock(&gl->gl_lockref.lock);
1718 gl->gl_lockref.count++;
1719 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1720 __gfs2_glock_queue_work(gl, 0);
1721 spin_unlock(&gl->gl_lockref.lock);
1724 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1726 struct gfs2_glock *gla, *glb;
1728 gla = list_entry(a, struct gfs2_glock, gl_lru);
1729 glb = list_entry(b, struct gfs2_glock, gl_lru);
1731 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1733 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1740 * gfs2_dispose_glock_lru - Demote a list of glocks
1741 * @list: The list to dispose of
1743 * Disposing of glocks may involve disk accesses, so that here we sort
1744 * the glocks by number (i.e. disk location of the inodes) so that if
1745 * there are any such accesses, they'll be sent in order (mostly).
1747 * Must be called under the lru_lock, but may drop and retake this
1748 * lock. While the lru_lock is dropped, entries may vanish from the
1749 * list, but no new entries will appear on the list (since it is
1753 static void gfs2_dispose_glock_lru(struct list_head *list)
1754 __releases(&lru_lock)
1755 __acquires(&lru_lock)
1757 struct gfs2_glock *gl;
1759 list_sort(NULL, list, glock_cmp);
1761 while(!list_empty(list)) {
1762 gl = list_first_entry(list, struct gfs2_glock, gl_lru);
1763 list_del_init(&gl->gl_lru);
1764 if (!spin_trylock(&gl->gl_lockref.lock)) {
1766 list_add(&gl->gl_lru, &lru_list);
1767 set_bit(GLF_LRU, &gl->gl_flags);
1768 atomic_inc(&lru_count);
1771 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1772 spin_unlock(&gl->gl_lockref.lock);
1773 goto add_back_to_lru;
1775 gl->gl_lockref.count++;
1777 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1778 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1779 __gfs2_glock_queue_work(gl, 0);
1780 spin_unlock(&gl->gl_lockref.lock);
1781 cond_resched_lock(&lru_lock);
1786 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1787 * @nr: The number of entries to scan
1789 * This function selects the entries on the LRU which are able to
1790 * be demoted, and then kicks off the process by calling
1791 * gfs2_dispose_glock_lru() above.
1794 static long gfs2_scan_glock_lru(int nr)
1796 struct gfs2_glock *gl;
1801 spin_lock(&lru_lock);
1802 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1803 gl = list_first_entry(&lru_list, struct gfs2_glock, gl_lru);
1805 /* Test for being demotable */
1806 if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
1807 list_move(&gl->gl_lru, &dispose);
1808 atomic_dec(&lru_count);
1809 clear_bit(GLF_LRU, &gl->gl_flags);
1814 list_move(&gl->gl_lru, &skipped);
1816 list_splice(&skipped, &lru_list);
1817 if (!list_empty(&dispose))
1818 gfs2_dispose_glock_lru(&dispose);
1819 spin_unlock(&lru_lock);
1824 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1825 struct shrink_control *sc)
1827 if (!(sc->gfp_mask & __GFP_FS))
1829 return gfs2_scan_glock_lru(sc->nr_to_scan);
1832 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1833 struct shrink_control *sc)
1835 return vfs_pressure_ratio(atomic_read(&lru_count));
1838 static struct shrinker glock_shrinker = {
1839 .seeks = DEFAULT_SEEKS,
1840 .count_objects = gfs2_glock_shrink_count,
1841 .scan_objects = gfs2_glock_shrink_scan,
1845 * examine_bucket - Call a function for glock in a hash bucket
1846 * @examiner: the function
1847 * @sdp: the filesystem
1848 * @bucket: the bucket
1850 * Note that the function can be called multiple times on the same
1851 * object. So the user must ensure that the function can cope with
1855 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1857 struct gfs2_glock *gl;
1858 struct rhashtable_iter iter;
1860 rhashtable_walk_enter(&gl_hash_table, &iter);
1863 rhashtable_walk_start(&iter);
1865 while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl))
1866 if (gl->gl_name.ln_sbd == sdp &&
1867 lockref_get_not_dead(&gl->gl_lockref))
1870 rhashtable_walk_stop(&iter);
1871 } while (cond_resched(), gl == ERR_PTR(-EAGAIN));
1873 rhashtable_walk_exit(&iter);
1876 bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay)
1880 spin_lock(&gl->gl_lockref.lock);
1881 queued = queue_delayed_work(gfs2_delete_workqueue,
1882 &gl->gl_delete, delay);
1884 set_bit(GLF_PENDING_DELETE, &gl->gl_flags);
1885 spin_unlock(&gl->gl_lockref.lock);
1889 void gfs2_cancel_delete_work(struct gfs2_glock *gl)
1891 if (cancel_delayed_work_sync(&gl->gl_delete)) {
1892 clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
1897 bool gfs2_delete_work_queued(const struct gfs2_glock *gl)
1899 return test_bit(GLF_PENDING_DELETE, &gl->gl_flags);
1902 static void flush_delete_work(struct gfs2_glock *gl)
1904 if (cancel_delayed_work(&gl->gl_delete)) {
1905 queue_delayed_work(gfs2_delete_workqueue,
1908 gfs2_glock_queue_work(gl, 0);
1911 void gfs2_flush_delete_work(struct gfs2_sbd *sdp)
1913 glock_hash_walk(flush_delete_work, sdp);
1914 flush_workqueue(gfs2_delete_workqueue);
1918 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1919 * @gl: The glock to thaw
1923 static void thaw_glock(struct gfs2_glock *gl)
1925 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) {
1929 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1930 gfs2_glock_queue_work(gl, 0);
1934 * clear_glock - look at a glock and see if we can free it from glock cache
1935 * @gl: the glock to look at
1939 static void clear_glock(struct gfs2_glock *gl)
1941 gfs2_glock_remove_from_lru(gl);
1943 spin_lock(&gl->gl_lockref.lock);
1944 if (gl->gl_state != LM_ST_UNLOCKED)
1945 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1946 __gfs2_glock_queue_work(gl, 0);
1947 spin_unlock(&gl->gl_lockref.lock);
1951 * gfs2_glock_thaw - Thaw any frozen glocks
1952 * @sdp: The super block
1956 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1958 glock_hash_walk(thaw_glock, sdp);
1961 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
1963 spin_lock(&gl->gl_lockref.lock);
1964 gfs2_dump_glock(seq, gl, fsid);
1965 spin_unlock(&gl->gl_lockref.lock);
1968 static void dump_glock_func(struct gfs2_glock *gl)
1970 dump_glock(NULL, gl, true);
1974 * gfs2_gl_hash_clear - Empty out the glock hash table
1975 * @sdp: the filesystem
1976 * @wait: wait until it's all gone
1978 * Called when unmounting the filesystem.
1981 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1983 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1984 flush_workqueue(glock_workqueue);
1985 glock_hash_walk(clear_glock, sdp);
1986 flush_workqueue(glock_workqueue);
1987 wait_event_timeout(sdp->sd_glock_wait,
1988 atomic_read(&sdp->sd_glock_disposal) == 0,
1990 glock_hash_walk(dump_glock_func, sdp);
1993 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1995 struct gfs2_glock *gl = ip->i_gl;
1998 ret = gfs2_truncatei_resume(ip);
1999 gfs2_glock_assert_withdraw(gl, ret == 0);
2001 spin_lock(&gl->gl_lockref.lock);
2002 clear_bit(GLF_LOCK, &gl->gl_flags);
2004 spin_unlock(&gl->gl_lockref.lock);
2007 static const char *state2str(unsigned state)
2010 case LM_ST_UNLOCKED:
2014 case LM_ST_DEFERRED:
2016 case LM_ST_EXCLUSIVE:
2022 static const char *hflags2str(char *buf, u16 flags, unsigned long iflags)
2025 if (flags & LM_FLAG_TRY)
2027 if (flags & LM_FLAG_TRY_1CB)
2029 if (flags & LM_FLAG_NOEXP)
2031 if (flags & LM_FLAG_ANY)
2033 if (flags & LM_FLAG_PRIORITY)
2035 if (flags & GL_ASYNC)
2037 if (flags & GL_EXACT)
2039 if (flags & GL_NOCACHE)
2041 if (test_bit(HIF_HOLDER, &iflags))
2043 if (test_bit(HIF_WAIT, &iflags))
2045 if (test_bit(HIF_FIRST, &iflags))
2052 * dump_holder - print information about a glock holder
2053 * @seq: the seq_file struct
2054 * @gh: the glock holder
2055 * @fs_id_buf: pointer to file system id (if requested)
2059 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh,
2060 const char *fs_id_buf)
2062 struct task_struct *gh_owner = NULL;
2066 if (gh->gh_owner_pid)
2067 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
2068 gfs2_print_dbg(seq, "%s H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
2069 fs_id_buf, state2str(gh->gh_state),
2070 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
2072 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
2073 gh_owner ? gh_owner->comm : "(ended)",
2078 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
2080 const unsigned long *gflags = &gl->gl_flags;
2083 if (test_bit(GLF_LOCK, gflags))
2085 if (test_bit(GLF_DEMOTE, gflags))
2087 if (test_bit(GLF_PENDING_DEMOTE, gflags))
2089 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
2091 if (test_bit(GLF_DIRTY, gflags))
2093 if (test_bit(GLF_LFLUSH, gflags))
2095 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
2097 if (test_bit(GLF_REPLY_PENDING, gflags))
2099 if (test_bit(GLF_INITIAL, gflags))
2101 if (test_bit(GLF_FROZEN, gflags))
2103 if (test_bit(GLF_QUEUED, gflags))
2105 if (test_bit(GLF_LRU, gflags))
2109 if (test_bit(GLF_BLOCKING, gflags))
2111 if (test_bit(GLF_INODE_CREATING, gflags))
2113 if (test_bit(GLF_PENDING_DELETE, gflags))
2115 if (test_bit(GLF_FREEING, gflags))
2122 * gfs2_dump_glock - print information about a glock
2123 * @seq: The seq_file struct
2125 * @fsid: If true, also dump the file system id
2127 * The file format is as follows:
2128 * One line per object, capital letters are used to indicate objects
2129 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
2130 * other objects are indented by a single space and follow the glock to
2131 * which they are related. Fields are indicated by lower case letters
2132 * followed by a colon and the field value, except for strings which are in
2133 * [] so that its possible to see if they are composed of spaces for
2134 * example. The field's are n = number (id of the object), f = flags,
2135 * t = type, s = state, r = refcount, e = error, p = pid.
2139 void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
2141 const struct gfs2_glock_operations *glops = gl->gl_ops;
2142 unsigned long long dtime;
2143 const struct gfs2_holder *gh;
2144 char gflags_buf[32];
2145 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
2146 char fs_id_buf[sizeof(sdp->sd_fsname) + 7];
2147 unsigned long nrpages = 0;
2149 if (gl->gl_ops->go_flags & GLOF_ASPACE) {
2150 struct address_space *mapping = gfs2_glock2aspace(gl);
2152 nrpages = mapping->nrpages;
2154 memset(fs_id_buf, 0, sizeof(fs_id_buf));
2155 if (fsid && sdp) /* safety precaution */
2156 sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname);
2157 dtime = jiffies - gl->gl_demote_time;
2158 dtime *= 1000000/HZ; /* demote time in uSec */
2159 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
2161 gfs2_print_dbg(seq, "%sG: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d "
2162 "v:%d r:%d m:%ld p:%lu\n",
2163 fs_id_buf, state2str(gl->gl_state),
2164 gl->gl_name.ln_type,
2165 (unsigned long long)gl->gl_name.ln_number,
2166 gflags2str(gflags_buf, gl),
2167 state2str(gl->gl_target),
2168 state2str(gl->gl_demote_state), dtime,
2169 atomic_read(&gl->gl_ail_count),
2170 atomic_read(&gl->gl_revokes),
2171 (int)gl->gl_lockref.count, gl->gl_hold_time, nrpages);
2173 list_for_each_entry(gh, &gl->gl_holders, gh_list)
2174 dump_holder(seq, gh, fs_id_buf);
2176 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
2177 glops->go_dump(seq, gl, fs_id_buf);
2180 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
2182 struct gfs2_glock *gl = iter_ptr;
2184 seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
2185 gl->gl_name.ln_type,
2186 (unsigned long long)gl->gl_name.ln_number,
2187 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
2188 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
2189 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
2190 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
2191 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
2192 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
2193 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
2194 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
2198 static const char *gfs2_gltype[] = {
2212 static const char *gfs2_stype[] = {
2213 [GFS2_LKS_SRTT] = "srtt",
2214 [GFS2_LKS_SRTTVAR] = "srttvar",
2215 [GFS2_LKS_SRTTB] = "srttb",
2216 [GFS2_LKS_SRTTVARB] = "srttvarb",
2217 [GFS2_LKS_SIRT] = "sirt",
2218 [GFS2_LKS_SIRTVAR] = "sirtvar",
2219 [GFS2_LKS_DCOUNT] = "dlm",
2220 [GFS2_LKS_QCOUNT] = "queue",
2223 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
2225 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
2227 struct gfs2_sbd *sdp = seq->private;
2228 loff_t pos = *(loff_t *)iter_ptr;
2229 unsigned index = pos >> 3;
2230 unsigned subindex = pos & 0x07;
2233 if (index == 0 && subindex != 0)
2236 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
2237 (index == 0) ? "cpu": gfs2_stype[subindex]);
2239 for_each_possible_cpu(i) {
2240 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
2243 seq_printf(seq, " %15u", i);
2245 seq_printf(seq, " %15llu", (unsigned long long)lkstats->
2246 lkstats[index - 1].stats[subindex]);
2248 seq_putc(seq, '\n');
2252 int __init gfs2_glock_init(void)
2256 ret = rhashtable_init(&gl_hash_table, &ht_parms);
2260 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
2261 WQ_HIGHPRI | WQ_FREEZABLE, 0);
2262 if (!glock_workqueue) {
2263 rhashtable_destroy(&gl_hash_table);
2266 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
2267 WQ_MEM_RECLAIM | WQ_FREEZABLE,
2269 if (!gfs2_delete_workqueue) {
2270 destroy_workqueue(glock_workqueue);
2271 rhashtable_destroy(&gl_hash_table);
2275 ret = register_shrinker(&glock_shrinker);
2277 destroy_workqueue(gfs2_delete_workqueue);
2278 destroy_workqueue(glock_workqueue);
2279 rhashtable_destroy(&gl_hash_table);
2283 for (i = 0; i < GLOCK_WAIT_TABLE_SIZE; i++)
2284 init_waitqueue_head(glock_wait_table + i);
2289 void gfs2_glock_exit(void)
2291 unregister_shrinker(&glock_shrinker);
2292 rhashtable_destroy(&gl_hash_table);
2293 destroy_workqueue(glock_workqueue);
2294 destroy_workqueue(gfs2_delete_workqueue);
2297 static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi, loff_t n)
2299 struct gfs2_glock *gl = gi->gl;
2304 if (!lockref_put_not_zero(&gl->gl_lockref))
2305 gfs2_glock_queue_put(gl);
2308 gl = rhashtable_walk_next(&gi->hti);
2309 if (IS_ERR_OR_NULL(gl)) {
2310 if (gl == ERR_PTR(-EAGAIN)) {
2317 if (gl->gl_name.ln_sbd != gi->sdp)
2320 if (!lockref_get_not_dead(&gl->gl_lockref))
2324 if (__lockref_is_dead(&gl->gl_lockref))
2332 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
2335 struct gfs2_glock_iter *gi = seq->private;
2339 * We can either stay where we are, skip to the next hash table
2340 * entry, or start from the beginning.
2342 if (*pos < gi->last_pos) {
2343 rhashtable_walk_exit(&gi->hti);
2344 rhashtable_walk_enter(&gl_hash_table, &gi->hti);
2347 n = *pos - gi->last_pos;
2350 rhashtable_walk_start(&gi->hti);
2352 gfs2_glock_iter_next(gi, n);
2353 gi->last_pos = *pos;
2357 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
2360 struct gfs2_glock_iter *gi = seq->private;
2363 gi->last_pos = *pos;
2364 gfs2_glock_iter_next(gi, 1);
2368 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
2371 struct gfs2_glock_iter *gi = seq->private;
2373 rhashtable_walk_stop(&gi->hti);
2376 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
2378 dump_glock(seq, iter_ptr, false);
2382 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
2385 if (*pos >= GFS2_NR_SBSTATS)
2390 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
2394 if (*pos >= GFS2_NR_SBSTATS)
2399 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
2404 static const struct seq_operations gfs2_glock_seq_ops = {
2405 .start = gfs2_glock_seq_start,
2406 .next = gfs2_glock_seq_next,
2407 .stop = gfs2_glock_seq_stop,
2408 .show = gfs2_glock_seq_show,
2411 static const struct seq_operations gfs2_glstats_seq_ops = {
2412 .start = gfs2_glock_seq_start,
2413 .next = gfs2_glock_seq_next,
2414 .stop = gfs2_glock_seq_stop,
2415 .show = gfs2_glstats_seq_show,
2418 static const struct seq_operations gfs2_sbstats_seq_ops = {
2419 .start = gfs2_sbstats_seq_start,
2420 .next = gfs2_sbstats_seq_next,
2421 .stop = gfs2_sbstats_seq_stop,
2422 .show = gfs2_sbstats_seq_show,
2425 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
2427 static int __gfs2_glocks_open(struct inode *inode, struct file *file,
2428 const struct seq_operations *ops)
2430 int ret = seq_open_private(file, ops, sizeof(struct gfs2_glock_iter));
2432 struct seq_file *seq = file->private_data;
2433 struct gfs2_glock_iter *gi = seq->private;
2435 gi->sdp = inode->i_private;
2436 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2438 seq->size = GFS2_SEQ_GOODSIZE;
2440 * Initially, we are "before" the first hash table entry; the
2441 * first call to rhashtable_walk_next gets us the first entry.
2445 rhashtable_walk_enter(&gl_hash_table, &gi->hti);
2450 static int gfs2_glocks_open(struct inode *inode, struct file *file)
2452 return __gfs2_glocks_open(inode, file, &gfs2_glock_seq_ops);
2455 static int gfs2_glocks_release(struct inode *inode, struct file *file)
2457 struct seq_file *seq = file->private_data;
2458 struct gfs2_glock_iter *gi = seq->private;
2461 gfs2_glock_put(gi->gl);
2462 rhashtable_walk_exit(&gi->hti);
2463 return seq_release_private(inode, file);
2466 static int gfs2_glstats_open(struct inode *inode, struct file *file)
2468 return __gfs2_glocks_open(inode, file, &gfs2_glstats_seq_ops);
2471 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
2473 int ret = seq_open(file, &gfs2_sbstats_seq_ops);
2475 struct seq_file *seq = file->private_data;
2476 seq->private = inode->i_private; /* sdp */
2481 static const struct file_operations gfs2_glocks_fops = {
2482 .owner = THIS_MODULE,
2483 .open = gfs2_glocks_open,
2485 .llseek = seq_lseek,
2486 .release = gfs2_glocks_release,
2489 static const struct file_operations gfs2_glstats_fops = {
2490 .owner = THIS_MODULE,
2491 .open = gfs2_glstats_open,
2493 .llseek = seq_lseek,
2494 .release = gfs2_glocks_release,
2497 static const struct file_operations gfs2_sbstats_fops = {
2498 .owner = THIS_MODULE,
2499 .open = gfs2_sbstats_open,
2501 .llseek = seq_lseek,
2502 .release = seq_release,
2505 void gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
2507 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
2509 debugfs_create_file("glocks", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
2512 debugfs_create_file("glstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
2513 &gfs2_glstats_fops);
2515 debugfs_create_file("sbstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp,
2516 &gfs2_sbstats_fops);
2519 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2521 debugfs_remove_recursive(sdp->debugfs_dir);
2522 sdp->debugfs_dir = NULL;
2525 void gfs2_register_debugfs(void)
2527 gfs2_root = debugfs_create_dir("gfs2", NULL);
2530 void gfs2_unregister_debugfs(void)
2532 debugfs_remove(gfs2_root);