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Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
[linux/fpc-iii.git] / fs / gfs2 / glock.c
blob706fd9352f368818391ad79f4481feffe0809b60
1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4 *
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.
8 */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
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>
38
39 #include "gfs2.h"
40 #include "incore.h"
41 #include "glock.h"
42 #include "glops.h"
43 #include "inode.h"
44 #include "lops.h"
45 #include "meta_io.h"
46 #include "quota.h"
47 #include "super.h"
48 #include "util.h"
49 #include "bmap.h"
50 #define CREATE_TRACE_POINTS
51 #include "trace_gfs2.h"
52
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 */
58 };
59
60 typedef void (*glock_examiner) (struct gfs2_glock * gl);
61
62 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
63
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);
70
71 #define GFS2_GL_HASH_SHIFT 15
72 #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
73
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),
79 };
80
81 static struct rhashtable gl_hash_table;
82
83 void gfs2_glock_free(struct gfs2_glock *gl)
84 {
85 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
86
87 if (gl->gl_ops->go_flags & GLOF_ASPACE) {
88 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
89 } else {
90 kfree(gl->gl_lksb.sb_lvbptr);
91 kmem_cache_free(gfs2_glock_cachep, gl);
92 }
93 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
94 wake_up(&sdp->sd_glock_wait);
95 }
96
97 /**
98 * gfs2_glock_hold() - increment reference count on glock
99 * @gl: The glock to hold
100 *
101 */
102
103 static void gfs2_glock_hold(struct gfs2_glock *gl)
104 {
105 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
106 lockref_get(&gl->gl_lockref);
107 }
108
109 /**
110 * demote_ok - Check to see if it's ok to unlock a glock
111 * @gl: the glock
112 *
113 * Returns: 1 if it's ok
114 */
115
116 static int demote_ok(const struct gfs2_glock *gl)
117 {
118 const struct gfs2_glock_operations *glops = gl->gl_ops;
119
120 if (gl->gl_state == LM_ST_UNLOCKED)
121 return 0;
122 if (!list_empty(&gl->gl_holders))
123 return 0;
124 if (glops->go_demote_ok)
125 return glops->go_demote_ok(gl);
126 return 1;
127 }
128
129
130 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
131 {
132 spin_lock(&lru_lock);
133
134 if (!list_empty(&gl->gl_lru))
135 list_del_init(&gl->gl_lru);
136 else
137 atomic_inc(&lru_count);
138
139 list_add_tail(&gl->gl_lru, &lru_list);
140 set_bit(GLF_LRU, &gl->gl_flags);
141 spin_unlock(&lru_lock);
142 }
143
144 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
145 {
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);
151 }
152 spin_unlock(&lru_lock);
153 }
154
155 /**
156 * gfs2_glock_put() - Decrement reference count on glock
157 * @gl: The glock to put
158 *
159 */
160
161 void gfs2_glock_put(struct gfs2_glock *gl)
162 {
163 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
164 struct address_space *mapping = gfs2_glock2aspace(gl);
165
166 if (lockref_put_or_lock(&gl->gl_lockref))
167 return;
168
169 lockref_mark_dead(&gl->gl_lockref);
170
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);
178 }
179
180 /**
181 * may_grant - check if its ok to grant a new lock
182 * @gl: The glock
183 * @gh: The lock request which we wish to grant
184 *
185 * Returns: true if its ok to grant the lock
186 */
187
188 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
189 {
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)
193 return 0;
194 if (gl->gl_state == gh->gh_state)
195 return 1;
196 if (gh->gh_flags & GL_EXACT)
197 return 0;
198 if (gl->gl_state == LM_ST_EXCLUSIVE) {
199 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
200 return 1;
201 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
202 return 1;
203 }
204 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
205 return 1;
206 return 0;
207 }
208
209 static void gfs2_holder_wake(struct gfs2_holder *gh)
210 {
211 clear_bit(HIF_WAIT, &gh->gh_iflags);
212 smp_mb__after_atomic();
213 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
214 }
215
216 /**
217 * do_error - Something unexpected has happened during a lock request
218 *
219 */
220
221 static void do_error(struct gfs2_glock *gl, const int ret)
222 {
223 struct gfs2_holder *gh, *tmp;
224
225 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
226 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
227 continue;
228 if (ret & LM_OUT_ERROR)
229 gh->gh_error = -EIO;
230 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
231 gh->gh_error = GLR_TRYFAILED;
232 else
233 continue;
234 list_del_init(&gh->gh_list);
235 trace_gfs2_glock_queue(gh, 0);
236 gfs2_holder_wake(gh);
237 }
238 }
239
240 /**
241 * do_promote - promote as many requests as possible on the current queue
242 * @gl: The glock
243 *
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.
246 */
247
248 static int do_promote(struct gfs2_glock *gl)
249 __releases(&gl->gl_lockref.lock)
250 __acquires(&gl->gl_lockref.lock)
251 {
252 const struct gfs2_glock_operations *glops = gl->gl_ops;
253 struct gfs2_holder *gh, *tmp;
254 int ret;
255
256 restart:
257 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
258 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
259 continue;
260 if (may_grant(gl, gh)) {
261 if (gh->gh_list.prev == &gl->gl_holders &&
262 glops->go_lock) {
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);
267 if (ret) {
268 if (ret == 1)
269 return 2;
270 gh->gh_error = ret;
271 list_del_init(&gh->gh_list);
272 trace_gfs2_glock_queue(gh, 0);
273 gfs2_holder_wake(gh);
274 goto restart;
275 }
276 set_bit(HIF_HOLDER, &gh->gh_iflags);
277 trace_gfs2_promote(gh, 1);
278 gfs2_holder_wake(gh);
279 goto restart;
280 }
281 set_bit(HIF_HOLDER, &gh->gh_iflags);
282 trace_gfs2_promote(gh, 0);
283 gfs2_holder_wake(gh);
284 continue;
285 }
286 if (gh->gh_list.prev == &gl->gl_holders)
287 return 1;
288 do_error(gl, 0);
289 break;
290 }
291 return 0;
292 }
293
294 /**
295 * find_first_waiter - find the first gh that's waiting for the glock
296 * @gl: the glock
297 */
298
299 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
300 {
301 struct gfs2_holder *gh;
302
303 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
304 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
305 return gh;
306 }
307 return NULL;
308 }
309
310 /**
311 * state_change - record that the glock is now in a different state
312 * @gl: the glock
313 * @new_state the new state
314 *
315 */
316
317 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
318 {
319 int held1, held2;
320
321 held1 = (gl->gl_state != LM_ST_UNLOCKED);
322 held2 = (new_state != LM_ST_UNLOCKED);
323
324 if (held1 != held2) {
325 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
326 if (held2)
327 gl->gl_lockref.count++;
328 else
329 gl->gl_lockref.count--;
330 }
331 if (held1 && held2 && list_empty(&gl->gl_holders))
332 clear_bit(GLF_QUEUED, &gl->gl_flags);
333
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,
337 GL_GLOCK_MIN_HOLD);
338 gl->gl_state = new_state;
339 gl->gl_tchange = jiffies;
340 }
341
342 static void gfs2_demote_wake(struct gfs2_glock *gl)
343 {
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);
348 }
349
350 /**
351 * finish_xmote - The DLM has replied to one of our lock requests
352 * @gl: The glock
353 * @ret: The status from the DLM
354 *
355 */
356
357 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
358 {
359 const struct gfs2_glock_operations *glops = gl->gl_ops;
360 struct gfs2_holder *gh;
361 unsigned state = ret & LM_OUT_ST_MASK;
362 int rv;
363
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);
368
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;
373
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;
383 goto retry;
384 }
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;
389 do_error(gl, ret);
390 goto out;
391 }
392 }
393 switch(state) {
394 /* Unlocked due to conversion deadlock, try again */
395 case LM_ST_UNLOCKED:
396 retry:
397 do_xmote(gl, gh, gl->gl_target);
398 break;
399 /* Conversion fails, unlock and try again */
400 case LM_ST_SHARED:
401 case LM_ST_DEFERRED:
402 do_xmote(gl, gh, LM_ST_UNLOCKED);
403 break;
404 default: /* Everything else */
405 pr_err("wanted %u got %u\n", gl->gl_target, state);
406 GLOCK_BUG_ON(gl, 1);
407 }
408 spin_unlock(&gl->gl_lockref.lock);
409 return;
410 }
411
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);
420 if (rv) {
421 do_error(gl, rv);
422 goto out;
423 }
424 }
425 rv = do_promote(gl);
426 if (rv == 2)
427 goto out_locked;
428 }
429 out:
430 clear_bit(GLF_LOCK, &gl->gl_flags);
431 out_locked:
432 spin_unlock(&gl->gl_lockref.lock);
433 }
434
435 /**
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
440 *
441 */
442
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)
446 {
447 const struct gfs2_glock_operations *glops = gl->gl_ops;
448 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
449 unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0);
450 int ret;
451
452 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
453 LM_FLAG_PRIORITY);
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) &&
457 glops->go_inval) {
458 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
459 do_error(gl, 0); /* Fail queued try locks */
460 }
461 gl->gl_req = target;
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);
468 if (glops->go_sync)
469 glops->go_sync(gl);
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);
473
474 gfs2_glock_hold(gl);
475 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
476 /* lock_dlm */
477 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
478 if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED &&
479 target == LM_ST_UNLOCKED &&
480 test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) {
481 finish_xmote(gl, target);
482 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
483 gfs2_glock_put(gl);
484 }
485 else if (ret) {
486 pr_err("lm_lock ret %d\n", ret);
487 GLOCK_BUG_ON(gl, 1);
488 }
489 } else { /* lock_nolock */
490 finish_xmote(gl, target);
491 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
492 gfs2_glock_put(gl);
493 }
494
495 spin_lock(&gl->gl_lockref.lock);
496 }
497
498 /**
499 * find_first_holder - find the first "holder" gh
500 * @gl: the glock
501 */
502
503 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
504 {
505 struct gfs2_holder *gh;
506
507 if (!list_empty(&gl->gl_holders)) {
508 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
509 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
510 return gh;
511 }
512 return NULL;
513 }
514
515 /**
516 * run_queue - do all outstanding tasks related to a glock
517 * @gl: The glock in question
518 * @nonblock: True if we must not block in run_queue
519 *
520 */
521
522 static void run_queue(struct gfs2_glock *gl, const int nonblock)
523 __releases(&gl->gl_lockref.lock)
524 __acquires(&gl->gl_lockref.lock)
525 {
526 struct gfs2_holder *gh = NULL;
527 int ret;
528
529 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
530 return;
531
532 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
533
534 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
535 gl->gl_demote_state != gl->gl_state) {
536 if (find_first_holder(gl))
537 goto out_unlock;
538 if (nonblock)
539 goto out_sched;
540 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
541 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
542 gl->gl_target = gl->gl_demote_state;
543 } else {
544 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
545 gfs2_demote_wake(gl);
546 ret = do_promote(gl);
547 if (ret == 0)
548 goto out_unlock;
549 if (ret == 2)
550 goto out;
551 gh = find_first_waiter(gl);
552 gl->gl_target = gh->gh_state;
553 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
554 do_error(gl, 0); /* Fail queued try locks */
555 }
556 do_xmote(gl, gh, gl->gl_target);
557 out:
558 return;
559
560 out_sched:
561 clear_bit(GLF_LOCK, &gl->gl_flags);
562 smp_mb__after_atomic();
563 gl->gl_lockref.count++;
564 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
565 gl->gl_lockref.count--;
566 return;
567
568 out_unlock:
569 clear_bit(GLF_LOCK, &gl->gl_flags);
570 smp_mb__after_atomic();
571 return;
572 }
573
574 static void delete_work_func(struct work_struct *work)
575 {
576 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
577 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
578 struct gfs2_inode *ip;
579 struct inode *inode;
580 u64 no_addr = gl->gl_name.ln_number;
581
582 /* If someone's using this glock to create a new dinode, the block must
583 have been freed by another node, then re-used, in which case our
584 iopen callback is too late after the fact. Ignore it. */
585 if (test_bit(GLF_INODE_CREATING, &gl->gl_flags))
586 goto out;
587
588 ip = gl->gl_object;
589 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
590
591 if (ip)
592 inode = gfs2_ilookup(sdp->sd_vfs, no_addr);
593 else
594 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
595 if (inode && !IS_ERR(inode)) {
596 d_prune_aliases(inode);
597 iput(inode);
598 }
599 out:
600 gfs2_glock_put(gl);
601 }
602
603 static void glock_work_func(struct work_struct *work)
604 {
605 unsigned long delay = 0;
606 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
607 int drop_ref = 0;
608
609 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
610 finish_xmote(gl, gl->gl_reply);
611 drop_ref = 1;
612 }
613 spin_lock(&gl->gl_lockref.lock);
614 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
615 gl->gl_state != LM_ST_UNLOCKED &&
616 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
617 unsigned long holdtime, now = jiffies;
618
619 holdtime = gl->gl_tchange + gl->gl_hold_time;
620 if (time_before(now, holdtime))
621 delay = holdtime - now;
622
623 if (!delay) {
624 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
625 set_bit(GLF_DEMOTE, &gl->gl_flags);
626 }
627 }
628 run_queue(gl, 0);
629 spin_unlock(&gl->gl_lockref.lock);
630 if (!delay)
631 gfs2_glock_put(gl);
632 else {
633 if (gl->gl_name.ln_type != LM_TYPE_INODE)
634 delay = 0;
635 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
636 gfs2_glock_put(gl);
637 }
638 if (drop_ref)
639 gfs2_glock_put(gl);
640 }
641
642 /**
643 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
644 * @sdp: The GFS2 superblock
645 * @number: the lock number
646 * @glops: The glock_operations to use
647 * @create: If 0, don't create the glock if it doesn't exist
648 * @glp: the glock is returned here
649 *
650 * This does not lock a glock, just finds/creates structures for one.
651 *
652 * Returns: errno
653 */
654
655 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
656 const struct gfs2_glock_operations *glops, int create,
657 struct gfs2_glock **glp)
658 {
659 struct super_block *s = sdp->sd_vfs;
660 struct lm_lockname name = { .ln_number = number,
661 .ln_type = glops->go_type,
662 .ln_sbd = sdp };
663 struct gfs2_glock *gl, *tmp = NULL;
664 struct address_space *mapping;
665 struct kmem_cache *cachep;
666 int ret, tries = 0;
667
668 gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
669 if (gl && !lockref_get_not_dead(&gl->gl_lockref))
670 gl = NULL;
671
672 *glp = gl;
673 if (gl)
674 return 0;
675 if (!create)
676 return -ENOENT;
677
678 if (glops->go_flags & GLOF_ASPACE)
679 cachep = gfs2_glock_aspace_cachep;
680 else
681 cachep = gfs2_glock_cachep;
682 gl = kmem_cache_alloc(cachep, GFP_NOFS);
683 if (!gl)
684 return -ENOMEM;
685
686 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
687
688 if (glops->go_flags & GLOF_LVB) {
689 gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_NOFS);
690 if (!gl->gl_lksb.sb_lvbptr) {
691 kmem_cache_free(cachep, gl);
692 return -ENOMEM;
693 }
694 }
695
696 atomic_inc(&sdp->sd_glock_disposal);
697 gl->gl_node.next = NULL;
698 gl->gl_flags = 0;
699 gl->gl_name = name;
700 gl->gl_lockref.count = 1;
701 gl->gl_state = LM_ST_UNLOCKED;
702 gl->gl_target = LM_ST_UNLOCKED;
703 gl->gl_demote_state = LM_ST_EXCLUSIVE;
704 gl->gl_ops = glops;
705 gl->gl_dstamp = ktime_set(0, 0);
706 preempt_disable();
707 /* We use the global stats to estimate the initial per-glock stats */
708 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
709 preempt_enable();
710 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
711 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
712 gl->gl_tchange = jiffies;
713 gl->gl_object = NULL;
714 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
715 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
716 INIT_WORK(&gl->gl_delete, delete_work_func);
717
718 mapping = gfs2_glock2aspace(gl);
719 if (mapping) {
720 mapping->a_ops = &gfs2_meta_aops;
721 mapping->host = s->s_bdev->bd_inode;
722 mapping->flags = 0;
723 mapping_set_gfp_mask(mapping, GFP_NOFS);
724 mapping->private_data = NULL;
725 mapping->writeback_index = 0;
726 }
727
728 again:
729 ret = rhashtable_lookup_insert_fast(&gl_hash_table, &gl->gl_node,
730 ht_parms);
731 if (ret == 0) {
732 *glp = gl;
733 return 0;
734 }
735
736 if (ret == -EEXIST) {
737 ret = 0;
738 tmp = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
739 if (tmp == NULL || !lockref_get_not_dead(&tmp->gl_lockref)) {
740 if (++tries < 100) {
741 cond_resched();
742 goto again;
743 }
744 tmp = NULL;
745 ret = -ENOMEM;
746 }
747 } else {
748 WARN_ON_ONCE(ret);
749 }
750 kfree(gl->gl_lksb.sb_lvbptr);
751 kmem_cache_free(cachep, gl);
752 atomic_dec(&sdp->sd_glock_disposal);
753 *glp = tmp;
754
755 return ret;
756 }
757
758 /**
759 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
760 * @gl: the glock
761 * @state: the state we're requesting
762 * @flags: the modifier flags
763 * @gh: the holder structure
764 *
765 */
766
767 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags,
768 struct gfs2_holder *gh)
769 {
770 INIT_LIST_HEAD(&gh->gh_list);
771 gh->gh_gl = gl;
772 gh->gh_ip = _RET_IP_;
773 gh->gh_owner_pid = get_pid(task_pid(current));
774 gh->gh_state = state;
775 gh->gh_flags = flags;
776 gh->gh_error = 0;
777 gh->gh_iflags = 0;
778 gfs2_glock_hold(gl);
779 }
780
781 /**
782 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
783 * @state: the state we're requesting
784 * @flags: the modifier flags
785 * @gh: the holder structure
786 *
787 * Don't mess with the glock.
788 *
789 */
790
791 void gfs2_holder_reinit(unsigned int state, u16 flags, struct gfs2_holder *gh)
792 {
793 gh->gh_state = state;
794 gh->gh_flags = flags;
795 gh->gh_iflags = 0;
796 gh->gh_ip = _RET_IP_;
797 put_pid(gh->gh_owner_pid);
798 gh->gh_owner_pid = get_pid(task_pid(current));
799 }
800
801 /**
802 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
803 * @gh: the holder structure
804 *
805 */
806
807 void gfs2_holder_uninit(struct gfs2_holder *gh)
808 {
809 put_pid(gh->gh_owner_pid);
810 gfs2_glock_put(gh->gh_gl);
811 gh->gh_gl = NULL;
812 gh->gh_ip = 0;
813 }
814
815 /**
816 * gfs2_glock_wait - wait on a glock acquisition
817 * @gh: the glock holder
818 *
819 * Returns: 0 on success
820 */
821
822 int gfs2_glock_wait(struct gfs2_holder *gh)
823 {
824 unsigned long time1 = jiffies;
825
826 might_sleep();
827 wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
828 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
829 /* Lengthen the minimum hold time. */
830 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
831 GL_GLOCK_HOLD_INCR,
832 GL_GLOCK_MAX_HOLD);
833 return gh->gh_error;
834 }
835
836 /**
837 * handle_callback - process a demote request
838 * @gl: the glock
839 * @state: the state the caller wants us to change to
840 *
841 * There are only two requests that we are going to see in actual
842 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
843 */
844
845 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
846 unsigned long delay, bool remote)
847 {
848 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
849
850 set_bit(bit, &gl->gl_flags);
851 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
852 gl->gl_demote_state = state;
853 gl->gl_demote_time = jiffies;
854 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
855 gl->gl_demote_state != state) {
856 gl->gl_demote_state = LM_ST_UNLOCKED;
857 }
858 if (gl->gl_ops->go_callback)
859 gl->gl_ops->go_callback(gl, remote);
860 trace_gfs2_demote_rq(gl, remote);
861 }
862
863 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
864 {
865 struct va_format vaf;
866 va_list args;
867
868 va_start(args, fmt);
869
870 if (seq) {
871 seq_vprintf(seq, fmt, args);
872 } else {
873 vaf.fmt = fmt;
874 vaf.va = &args;
875
876 pr_err("%pV", &vaf);
877 }
878
879 va_end(args);
880 }
881
882 /**
883 * add_to_queue - Add a holder to the wait queue (but look for recursion)
884 * @gh: the holder structure to add
885 *
886 * Eventually we should move the recursive locking trap to a
887 * debugging option or something like that. This is the fast
888 * path and needs to have the minimum number of distractions.
889 *
890 */
891
892 static inline void add_to_queue(struct gfs2_holder *gh)
893 __releases(&gl->gl_lockref.lock)
894 __acquires(&gl->gl_lockref.lock)
895 {
896 struct gfs2_glock *gl = gh->gh_gl;
897 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
898 struct list_head *insert_pt = NULL;
899 struct gfs2_holder *gh2;
900 int try_futile = 0;
901
902 BUG_ON(gh->gh_owner_pid == NULL);
903 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
904 BUG();
905
906 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
907 if (test_bit(GLF_LOCK, &gl->gl_flags))
908 try_futile = !may_grant(gl, gh);
909 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
910 goto fail;
911 }
912
913 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
914 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
915 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
916 goto trap_recursive;
917 if (try_futile &&
918 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
919 fail:
920 gh->gh_error = GLR_TRYFAILED;
921 gfs2_holder_wake(gh);
922 return;
923 }
924 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
925 continue;
926 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
927 insert_pt = &gh2->gh_list;
928 }
929 set_bit(GLF_QUEUED, &gl->gl_flags);
930 trace_gfs2_glock_queue(gh, 1);
931 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
932 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
933 if (likely(insert_pt == NULL)) {
934 list_add_tail(&gh->gh_list, &gl->gl_holders);
935 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
936 goto do_cancel;
937 return;
938 }
939 list_add_tail(&gh->gh_list, insert_pt);
940 do_cancel:
941 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
942 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
943 spin_unlock(&gl->gl_lockref.lock);
944 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
945 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
946 spin_lock(&gl->gl_lockref.lock);
947 }
948 return;
949
950 trap_recursive:
951 pr_err("original: %pSR\n", (void *)gh2->gh_ip);
952 pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid));
953 pr_err("lock type: %d req lock state : %d\n",
954 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
955 pr_err("new: %pSR\n", (void *)gh->gh_ip);
956 pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid));
957 pr_err("lock type: %d req lock state : %d\n",
958 gh->gh_gl->gl_name.ln_type, gh->gh_state);
959 gfs2_dump_glock(NULL, gl);
960 BUG();
961 }
962
963 /**
964 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
965 * @gh: the holder structure
966 *
967 * if (gh->gh_flags & GL_ASYNC), this never returns an error
968 *
969 * Returns: 0, GLR_TRYFAILED, or errno on failure
970 */
971
972 int gfs2_glock_nq(struct gfs2_holder *gh)
973 {
974 struct gfs2_glock *gl = gh->gh_gl;
975 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
976 int error = 0;
977
978 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
979 return -EIO;
980
981 if (test_bit(GLF_LRU, &gl->gl_flags))
982 gfs2_glock_remove_from_lru(gl);
983
984 spin_lock(&gl->gl_lockref.lock);
985 add_to_queue(gh);
986 if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
987 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
988 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
989 gl->gl_lockref.count++;
990 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
991 gl->gl_lockref.count--;
992 }
993 run_queue(gl, 1);
994 spin_unlock(&gl->gl_lockref.lock);
995
996 if (!(gh->gh_flags & GL_ASYNC))
997 error = gfs2_glock_wait(gh);
998
999 return error;
1000 }
1001
1002 /**
1003 * gfs2_glock_poll - poll to see if an async request has been completed
1004 * @gh: the holder
1005 *
1006 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1007 */
1008
1009 int gfs2_glock_poll(struct gfs2_holder *gh)
1010 {
1011 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1012 }
1013
1014 /**
1015 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1016 * @gh: the glock holder
1017 *
1018 */
1019
1020 void gfs2_glock_dq(struct gfs2_holder *gh)
1021 {
1022 struct gfs2_glock *gl = gh->gh_gl;
1023 const struct gfs2_glock_operations *glops = gl->gl_ops;
1024 unsigned delay = 0;
1025 int fast_path = 0;
1026
1027 spin_lock(&gl->gl_lockref.lock);
1028 if (gh->gh_flags & GL_NOCACHE)
1029 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1030
1031 list_del_init(&gh->gh_list);
1032 clear_bit(HIF_HOLDER, &gh->gh_iflags);
1033 if (find_first_holder(gl) == NULL) {
1034 if (glops->go_unlock) {
1035 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1036 spin_unlock(&gl->gl_lockref.lock);
1037 glops->go_unlock(gh);
1038 spin_lock(&gl->gl_lockref.lock);
1039 clear_bit(GLF_LOCK, &gl->gl_flags);
1040 }
1041 if (list_empty(&gl->gl_holders) &&
1042 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1043 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1044 fast_path = 1;
1045 }
1046 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl) &&
1047 (glops->go_flags & GLOF_LRU))
1048 gfs2_glock_add_to_lru(gl);
1049
1050 trace_gfs2_glock_queue(gh, 0);
1051 spin_unlock(&gl->gl_lockref.lock);
1052 if (likely(fast_path))
1053 return;
1054
1055 gfs2_glock_hold(gl);
1056 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1057 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1058 gl->gl_name.ln_type == LM_TYPE_INODE)
1059 delay = gl->gl_hold_time;
1060 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1061 gfs2_glock_put(gl);
1062 }
1063
1064 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1065 {
1066 struct gfs2_glock *gl = gh->gh_gl;
1067 gfs2_glock_dq(gh);
1068 might_sleep();
1069 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
1070 }
1071
1072 /**
1073 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1074 * @gh: the holder structure
1075 *
1076 */
1077
1078 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1079 {
1080 gfs2_glock_dq(gh);
1081 gfs2_holder_uninit(gh);
1082 }
1083
1084 /**
1085 * gfs2_glock_nq_num - acquire a glock based on lock number
1086 * @sdp: the filesystem
1087 * @number: the lock number
1088 * @glops: the glock operations for the type of glock
1089 * @state: the state to acquire the glock in
1090 * @flags: modifier flags for the acquisition
1091 * @gh: the struct gfs2_holder
1092 *
1093 * Returns: errno
1094 */
1095
1096 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1097 const struct gfs2_glock_operations *glops,
1098 unsigned int state, u16 flags, struct gfs2_holder *gh)
1099 {
1100 struct gfs2_glock *gl;
1101 int error;
1102
1103 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1104 if (!error) {
1105 error = gfs2_glock_nq_init(gl, state, flags, gh);
1106 gfs2_glock_put(gl);
1107 }
1108
1109 return error;
1110 }
1111
1112 /**
1113 * glock_compare - Compare two struct gfs2_glock structures for sorting
1114 * @arg_a: the first structure
1115 * @arg_b: the second structure
1116 *
1117 */
1118
1119 static int glock_compare(const void *arg_a, const void *arg_b)
1120 {
1121 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1122 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1123 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1124 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1125
1126 if (a->ln_number > b->ln_number)
1127 return 1;
1128 if (a->ln_number < b->ln_number)
1129 return -1;
1130 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1131 return 0;
1132 }
1133
1134 /**
1135 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1136 * @num_gh: the number of structures
1137 * @ghs: an array of struct gfs2_holder structures
1138 *
1139 * Returns: 0 on success (all glocks acquired),
1140 * errno on failure (no glocks acquired)
1141 */
1142
1143 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1144 struct gfs2_holder **p)
1145 {
1146 unsigned int x;
1147 int error = 0;
1148
1149 for (x = 0; x < num_gh; x++)
1150 p[x] = &ghs[x];
1151
1152 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1153
1154 for (x = 0; x < num_gh; x++) {
1155 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1156
1157 error = gfs2_glock_nq(p[x]);
1158 if (error) {
1159 while (x--)
1160 gfs2_glock_dq(p[x]);
1161 break;
1162 }
1163 }
1164
1165 return error;
1166 }
1167
1168 /**
1169 * gfs2_glock_nq_m - acquire multiple glocks
1170 * @num_gh: the number of structures
1171 * @ghs: an array of struct gfs2_holder structures
1172 *
1173 *
1174 * Returns: 0 on success (all glocks acquired),
1175 * errno on failure (no glocks acquired)
1176 */
1177
1178 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1179 {
1180 struct gfs2_holder *tmp[4];
1181 struct gfs2_holder **pph = tmp;
1182 int error = 0;
1183
1184 switch(num_gh) {
1185 case 0:
1186 return 0;
1187 case 1:
1188 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1189 return gfs2_glock_nq(ghs);
1190 default:
1191 if (num_gh <= 4)
1192 break;
1193 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1194 if (!pph)
1195 return -ENOMEM;
1196 }
1197
1198 error = nq_m_sync(num_gh, ghs, pph);
1199
1200 if (pph != tmp)
1201 kfree(pph);
1202
1203 return error;
1204 }
1205
1206 /**
1207 * gfs2_glock_dq_m - release multiple glocks
1208 * @num_gh: the number of structures
1209 * @ghs: an array of struct gfs2_holder structures
1210 *
1211 */
1212
1213 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1214 {
1215 while (num_gh--)
1216 gfs2_glock_dq(&ghs[num_gh]);
1217 }
1218
1219 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1220 {
1221 unsigned long delay = 0;
1222 unsigned long holdtime;
1223 unsigned long now = jiffies;
1224
1225 gfs2_glock_hold(gl);
1226 holdtime = gl->gl_tchange + gl->gl_hold_time;
1227 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1228 gl->gl_name.ln_type == LM_TYPE_INODE) {
1229 if (time_before(now, holdtime))
1230 delay = holdtime - now;
1231 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1232 delay = gl->gl_hold_time;
1233 }
1234
1235 spin_lock(&gl->gl_lockref.lock);
1236 handle_callback(gl, state, delay, true);
1237 spin_unlock(&gl->gl_lockref.lock);
1238 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1239 gfs2_glock_put(gl);
1240 }
1241
1242 /**
1243 * gfs2_should_freeze - Figure out if glock should be frozen
1244 * @gl: The glock in question
1245 *
1246 * Glocks are not frozen if (a) the result of the dlm operation is
1247 * an error, (b) the locking operation was an unlock operation or
1248 * (c) if there is a "noexp" flagged request anywhere in the queue
1249 *
1250 * Returns: 1 if freezing should occur, 0 otherwise
1251 */
1252
1253 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1254 {
1255 const struct gfs2_holder *gh;
1256
1257 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1258 return 0;
1259 if (gl->gl_target == LM_ST_UNLOCKED)
1260 return 0;
1261
1262 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1263 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1264 continue;
1265 if (LM_FLAG_NOEXP & gh->gh_flags)
1266 return 0;
1267 }
1268
1269 return 1;
1270 }
1271
1272 /**
1273 * gfs2_glock_complete - Callback used by locking
1274 * @gl: Pointer to the glock
1275 * @ret: The return value from the dlm
1276 *
1277 * The gl_reply field is under the gl_lockref.lock lock so that it is ok
1278 * to use a bitfield shared with other glock state fields.
1279 */
1280
1281 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1282 {
1283 struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
1284
1285 spin_lock(&gl->gl_lockref.lock);
1286 gl->gl_reply = ret;
1287
1288 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1289 if (gfs2_should_freeze(gl)) {
1290 set_bit(GLF_FROZEN, &gl->gl_flags);
1291 spin_unlock(&gl->gl_lockref.lock);
1292 return;
1293 }
1294 }
1295
1296 gl->gl_lockref.count++;
1297 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1298 spin_unlock(&gl->gl_lockref.lock);
1299
1300 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1301 gfs2_glock_put(gl);
1302 }
1303
1304 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1305 {
1306 struct gfs2_glock *gla, *glb;
1307
1308 gla = list_entry(a, struct gfs2_glock, gl_lru);
1309 glb = list_entry(b, struct gfs2_glock, gl_lru);
1310
1311 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1312 return 1;
1313 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1314 return -1;
1315
1316 return 0;
1317 }
1318
1319 /**
1320 * gfs2_dispose_glock_lru - Demote a list of glocks
1321 * @list: The list to dispose of
1322 *
1323 * Disposing of glocks may involve disk accesses, so that here we sort
1324 * the glocks by number (i.e. disk location of the inodes) so that if
1325 * there are any such accesses, they'll be sent in order (mostly).
1326 *
1327 * Must be called under the lru_lock, but may drop and retake this
1328 * lock. While the lru_lock is dropped, entries may vanish from the
1329 * list, but no new entries will appear on the list (since it is
1330 * private)
1331 */
1332
1333 static void gfs2_dispose_glock_lru(struct list_head *list)
1334 __releases(&lru_lock)
1335 __acquires(&lru_lock)
1336 {
1337 struct gfs2_glock *gl;
1338
1339 list_sort(NULL, list, glock_cmp);
1340
1341 while(!list_empty(list)) {
1342 gl = list_entry(list->next, struct gfs2_glock, gl_lru);
1343 list_del_init(&gl->gl_lru);
1344 if (!spin_trylock(&gl->gl_lockref.lock)) {
1345 add_back_to_lru:
1346 list_add(&gl->gl_lru, &lru_list);
1347 atomic_inc(&lru_count);
1348 continue;
1349 }
1350 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1351 spin_unlock(&gl->gl_lockref.lock);
1352 goto add_back_to_lru;
1353 }
1354 clear_bit(GLF_LRU, &gl->gl_flags);
1355 gl->gl_lockref.count++;
1356 if (demote_ok(gl))
1357 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1358 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1359 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1360 gl->gl_lockref.count--;
1361 spin_unlock(&gl->gl_lockref.lock);
1362 cond_resched_lock(&lru_lock);
1363 }
1364 }
1365
1366 /**
1367 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1368 * @nr: The number of entries to scan
1369 *
1370 * This function selects the entries on the LRU which are able to
1371 * be demoted, and then kicks off the process by calling
1372 * gfs2_dispose_glock_lru() above.
1373 */
1374
1375 static long gfs2_scan_glock_lru(int nr)
1376 {
1377 struct gfs2_glock *gl;
1378 LIST_HEAD(skipped);
1379 LIST_HEAD(dispose);
1380 long freed = 0;
1381
1382 spin_lock(&lru_lock);
1383 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1384 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1385
1386 /* Test for being demotable */
1387 if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
1388 list_move(&gl->gl_lru, &dispose);
1389 atomic_dec(&lru_count);
1390 freed++;
1391 continue;
1392 }
1393
1394 list_move(&gl->gl_lru, &skipped);
1395 }
1396 list_splice(&skipped, &lru_list);
1397 if (!list_empty(&dispose))
1398 gfs2_dispose_glock_lru(&dispose);
1399 spin_unlock(&lru_lock);
1400
1401 return freed;
1402 }
1403
1404 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1405 struct shrink_control *sc)
1406 {
1407 if (!(sc->gfp_mask & __GFP_FS))
1408 return SHRINK_STOP;
1409 return gfs2_scan_glock_lru(sc->nr_to_scan);
1410 }
1411
1412 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1413 struct shrink_control *sc)
1414 {
1415 return vfs_pressure_ratio(atomic_read(&lru_count));
1416 }
1417
1418 static struct shrinker glock_shrinker = {
1419 .seeks = DEFAULT_SEEKS,
1420 .count_objects = gfs2_glock_shrink_count,
1421 .scan_objects = gfs2_glock_shrink_scan,
1422 };
1423
1424 /**
1425 * examine_bucket - Call a function for glock in a hash bucket
1426 * @examiner: the function
1427 * @sdp: the filesystem
1428 * @bucket: the bucket
1429 *
1430 */
1431
1432 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1433 {
1434 struct gfs2_glock *gl;
1435 struct rhash_head *pos;
1436 const struct bucket_table *tbl;
1437 int i;
1438
1439 rcu_read_lock();
1440 tbl = rht_dereference_rcu(gl_hash_table.tbl, &gl_hash_table);
1441 for (i = 0; i < tbl->size; i++) {
1442 rht_for_each_entry_rcu(gl, pos, tbl, i, gl_node) {
1443 if ((gl->gl_name.ln_sbd == sdp) &&
1444 lockref_get_not_dead(&gl->gl_lockref))
1445 examiner(gl);
1446 }
1447 }
1448 rcu_read_unlock();
1449 cond_resched();
1450 }
1451
1452 /**
1453 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1454 * @gl: The glock to thaw
1455 *
1456 */
1457
1458 static void thaw_glock(struct gfs2_glock *gl)
1459 {
1460 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1461 goto out;
1462 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1463 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
1464 out:
1465 gfs2_glock_put(gl);
1466 }
1467 }
1468
1469 /**
1470 * clear_glock - look at a glock and see if we can free it from glock cache
1471 * @gl: the glock to look at
1472 *
1473 */
1474
1475 static void clear_glock(struct gfs2_glock *gl)
1476 {
1477 gfs2_glock_remove_from_lru(gl);
1478
1479 spin_lock(&gl->gl_lockref.lock);
1480 if (gl->gl_state != LM_ST_UNLOCKED)
1481 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1482 spin_unlock(&gl->gl_lockref.lock);
1483 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1484 gfs2_glock_put(gl);
1485 }
1486
1487 /**
1488 * gfs2_glock_thaw - Thaw any frozen glocks
1489 * @sdp: The super block
1490 *
1491 */
1492
1493 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1494 {
1495 glock_hash_walk(thaw_glock, sdp);
1496 }
1497
1498 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1499 {
1500 spin_lock(&gl->gl_lockref.lock);
1501 gfs2_dump_glock(seq, gl);
1502 spin_unlock(&gl->gl_lockref.lock);
1503 }
1504
1505 static void dump_glock_func(struct gfs2_glock *gl)
1506 {
1507 dump_glock(NULL, gl);
1508 }
1509
1510 /**
1511 * gfs2_gl_hash_clear - Empty out the glock hash table
1512 * @sdp: the filesystem
1513 * @wait: wait until it's all gone
1514 *
1515 * Called when unmounting the filesystem.
1516 */
1517
1518 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1519 {
1520 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1521 flush_workqueue(glock_workqueue);
1522 glock_hash_walk(clear_glock, sdp);
1523 flush_workqueue(glock_workqueue);
1524 wait_event_timeout(sdp->sd_glock_wait,
1525 atomic_read(&sdp->sd_glock_disposal) == 0,
1526 HZ * 600);
1527 glock_hash_walk(dump_glock_func, sdp);
1528 }
1529
1530 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1531 {
1532 struct gfs2_glock *gl = ip->i_gl;
1533 int ret;
1534
1535 ret = gfs2_truncatei_resume(ip);
1536 gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0);
1537
1538 spin_lock(&gl->gl_lockref.lock);
1539 clear_bit(GLF_LOCK, &gl->gl_flags);
1540 run_queue(gl, 1);
1541 spin_unlock(&gl->gl_lockref.lock);
1542 }
1543
1544 static const char *state2str(unsigned state)
1545 {
1546 switch(state) {
1547 case LM_ST_UNLOCKED:
1548 return "UN";
1549 case LM_ST_SHARED:
1550 return "SH";
1551 case LM_ST_DEFERRED:
1552 return "DF";
1553 case LM_ST_EXCLUSIVE:
1554 return "EX";
1555 }
1556 return "??";
1557 }
1558
1559 static const char *hflags2str(char *buf, u16 flags, unsigned long iflags)
1560 {
1561 char *p = buf;
1562 if (flags & LM_FLAG_TRY)
1563 *p++ = 't';
1564 if (flags & LM_FLAG_TRY_1CB)
1565 *p++ = 'T';
1566 if (flags & LM_FLAG_NOEXP)
1567 *p++ = 'e';
1568 if (flags & LM_FLAG_ANY)
1569 *p++ = 'A';
1570 if (flags & LM_FLAG_PRIORITY)
1571 *p++ = 'p';
1572 if (flags & GL_ASYNC)
1573 *p++ = 'a';
1574 if (flags & GL_EXACT)
1575 *p++ = 'E';
1576 if (flags & GL_NOCACHE)
1577 *p++ = 'c';
1578 if (test_bit(HIF_HOLDER, &iflags))
1579 *p++ = 'H';
1580 if (test_bit(HIF_WAIT, &iflags))
1581 *p++ = 'W';
1582 if (test_bit(HIF_FIRST, &iflags))
1583 *p++ = 'F';
1584 *p = 0;
1585 return buf;
1586 }
1587
1588 /**
1589 * dump_holder - print information about a glock holder
1590 * @seq: the seq_file struct
1591 * @gh: the glock holder
1592 *
1593 */
1594
1595 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1596 {
1597 struct task_struct *gh_owner = NULL;
1598 char flags_buf[32];
1599
1600 rcu_read_lock();
1601 if (gh->gh_owner_pid)
1602 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1603 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1604 state2str(gh->gh_state),
1605 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1606 gh->gh_error,
1607 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1608 gh_owner ? gh_owner->comm : "(ended)",
1609 (void *)gh->gh_ip);
1610 rcu_read_unlock();
1611 }
1612
1613 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1614 {
1615 const unsigned long *gflags = &gl->gl_flags;
1616 char *p = buf;
1617
1618 if (test_bit(GLF_LOCK, gflags))
1619 *p++ = 'l';
1620 if (test_bit(GLF_DEMOTE, gflags))
1621 *p++ = 'D';
1622 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1623 *p++ = 'd';
1624 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1625 *p++ = 'p';
1626 if (test_bit(GLF_DIRTY, gflags))
1627 *p++ = 'y';
1628 if (test_bit(GLF_LFLUSH, gflags))
1629 *p++ = 'f';
1630 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1631 *p++ = 'i';
1632 if (test_bit(GLF_REPLY_PENDING, gflags))
1633 *p++ = 'r';
1634 if (test_bit(GLF_INITIAL, gflags))
1635 *p++ = 'I';
1636 if (test_bit(GLF_FROZEN, gflags))
1637 *p++ = 'F';
1638 if (test_bit(GLF_QUEUED, gflags))
1639 *p++ = 'q';
1640 if (test_bit(GLF_LRU, gflags))
1641 *p++ = 'L';
1642 if (gl->gl_object)
1643 *p++ = 'o';
1644 if (test_bit(GLF_BLOCKING, gflags))
1645 *p++ = 'b';
1646 *p = 0;
1647 return buf;
1648 }
1649
1650 /**
1651 * gfs2_dump_glock - print information about a glock
1652 * @seq: The seq_file struct
1653 * @gl: the glock
1654 *
1655 * The file format is as follows:
1656 * One line per object, capital letters are used to indicate objects
1657 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1658 * other objects are indented by a single space and follow the glock to
1659 * which they are related. Fields are indicated by lower case letters
1660 * followed by a colon and the field value, except for strings which are in
1661 * [] so that its possible to see if they are composed of spaces for
1662 * example. The field's are n = number (id of the object), f = flags,
1663 * t = type, s = state, r = refcount, e = error, p = pid.
1664 *
1665 */
1666
1667 void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1668 {
1669 const struct gfs2_glock_operations *glops = gl->gl_ops;
1670 unsigned long long dtime;
1671 const struct gfs2_holder *gh;
1672 char gflags_buf[32];
1673
1674 dtime = jiffies - gl->gl_demote_time;
1675 dtime *= 1000000/HZ; /* demote time in uSec */
1676 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1677 dtime = 0;
1678 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",
1679 state2str(gl->gl_state),
1680 gl->gl_name.ln_type,
1681 (unsigned long long)gl->gl_name.ln_number,
1682 gflags2str(gflags_buf, gl),
1683 state2str(gl->gl_target),
1684 state2str(gl->gl_demote_state), dtime,
1685 atomic_read(&gl->gl_ail_count),
1686 atomic_read(&gl->gl_revokes),
1687 (int)gl->gl_lockref.count, gl->gl_hold_time);
1688
1689 list_for_each_entry(gh, &gl->gl_holders, gh_list)
1690 dump_holder(seq, gh);
1691
1692 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1693 glops->go_dump(seq, gl);
1694 }
1695
1696 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1697 {
1698 struct gfs2_glock *gl = iter_ptr;
1699
1700 seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
1701 gl->gl_name.ln_type,
1702 (unsigned long long)gl->gl_name.ln_number,
1703 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1704 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1705 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1706 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1707 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1708 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1709 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1710 (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1711 return 0;
1712 }
1713
1714 static const char *gfs2_gltype[] = {
1715 "type",
1716 "reserved",
1717 "nondisk",
1718 "inode",
1719 "rgrp",
1720 "meta",
1721 "iopen",
1722 "flock",
1723 "plock",
1724 "quota",
1725 "journal",
1726 };
1727
1728 static const char *gfs2_stype[] = {
1729 [GFS2_LKS_SRTT] = "srtt",
1730 [GFS2_LKS_SRTTVAR] = "srttvar",
1731 [GFS2_LKS_SRTTB] = "srttb",
1732 [GFS2_LKS_SRTTVARB] = "srttvarb",
1733 [GFS2_LKS_SIRT] = "sirt",
1734 [GFS2_LKS_SIRTVAR] = "sirtvar",
1735 [GFS2_LKS_DCOUNT] = "dlm",
1736 [GFS2_LKS_QCOUNT] = "queue",
1737 };
1738
1739 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1740
1741 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1742 {
1743 struct gfs2_sbd *sdp = seq->private;
1744 loff_t pos = *(loff_t *)iter_ptr;
1745 unsigned index = pos >> 3;
1746 unsigned subindex = pos & 0x07;
1747 int i;
1748
1749 if (index == 0 && subindex != 0)
1750 return 0;
1751
1752 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1753 (index == 0) ? "cpu": gfs2_stype[subindex]);
1754
1755 for_each_possible_cpu(i) {
1756 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1757
1758 if (index == 0)
1759 seq_printf(seq, " %15u", i);
1760 else
1761 seq_printf(seq, " %15llu", (unsigned long long)lkstats->
1762 lkstats[index - 1].stats[subindex]);
1763 }
1764 seq_putc(seq, '\n');
1765 return 0;
1766 }
1767
1768 int __init gfs2_glock_init(void)
1769 {
1770 int ret;
1771
1772 ret = rhashtable_init(&gl_hash_table, &ht_parms);
1773 if (ret < 0)
1774 return ret;
1775
1776 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1777 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1778 if (!glock_workqueue) {
1779 rhashtable_destroy(&gl_hash_table);
1780 return -ENOMEM;
1781 }
1782 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1783 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1784 0);
1785 if (!gfs2_delete_workqueue) {
1786 destroy_workqueue(glock_workqueue);
1787 rhashtable_destroy(&gl_hash_table);
1788 return -ENOMEM;
1789 }
1790
1791 register_shrinker(&glock_shrinker);
1792
1793 return 0;
1794 }
1795
1796 void gfs2_glock_exit(void)
1797 {
1798 unregister_shrinker(&glock_shrinker);
1799 rhashtable_destroy(&gl_hash_table);
1800 destroy_workqueue(glock_workqueue);
1801 destroy_workqueue(gfs2_delete_workqueue);
1802 }
1803
1804 static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1805 {
1806 do {
1807 gi->gl = rhashtable_walk_next(&gi->hti);
1808 if (IS_ERR(gi->gl)) {
1809 if (PTR_ERR(gi->gl) == -EAGAIN)
1810 continue;
1811 gi->gl = NULL;
1812 }
1813 /* Skip entries for other sb and dead entries */
1814 } while ((gi->gl) && ((gi->sdp != gi->gl->gl_name.ln_sbd) ||
1815 __lockref_is_dead(&gi->gl->gl_lockref)));
1816 }
1817
1818 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1819 {
1820 struct gfs2_glock_iter *gi = seq->private;
1821 loff_t n = *pos;
1822 int ret;
1823
1824 if (gi->last_pos <= *pos)
1825 n = (*pos - gi->last_pos);
1826
1827 ret = rhashtable_walk_start(&gi->hti);
1828 if (ret)
1829 return NULL;
1830
1831 do {
1832 gfs2_glock_iter_next(gi);
1833 } while (gi->gl && n--);
1834
1835 gi->last_pos = *pos;
1836 return gi->gl;
1837 }
1838
1839 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1840 loff_t *pos)
1841 {
1842 struct gfs2_glock_iter *gi = seq->private;
1843
1844 (*pos)++;
1845 gi->last_pos = *pos;
1846 gfs2_glock_iter_next(gi);
1847 return gi->gl;
1848 }
1849
1850 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1851 {
1852 struct gfs2_glock_iter *gi = seq->private;
1853
1854 gi->gl = NULL;
1855 rhashtable_walk_stop(&gi->hti);
1856 }
1857
1858 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1859 {
1860 dump_glock(seq, iter_ptr);
1861 return 0;
1862 }
1863
1864 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1865 {
1866 preempt_disable();
1867 if (*pos >= GFS2_NR_SBSTATS)
1868 return NULL;
1869 return pos;
1870 }
1871
1872 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1873 loff_t *pos)
1874 {
1875 (*pos)++;
1876 if (*pos >= GFS2_NR_SBSTATS)
1877 return NULL;
1878 return pos;
1879 }
1880
1881 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1882 {
1883 preempt_enable();
1884 }
1885
1886 static const struct seq_operations gfs2_glock_seq_ops = {
1887 .start = gfs2_glock_seq_start,
1888 .next = gfs2_glock_seq_next,
1889 .stop = gfs2_glock_seq_stop,
1890 .show = gfs2_glock_seq_show,
1891 };
1892
1893 static const struct seq_operations gfs2_glstats_seq_ops = {
1894 .start = gfs2_glock_seq_start,
1895 .next = gfs2_glock_seq_next,
1896 .stop = gfs2_glock_seq_stop,
1897 .show = gfs2_glstats_seq_show,
1898 };
1899
1900 static const struct seq_operations gfs2_sbstats_seq_ops = {
1901 .start = gfs2_sbstats_seq_start,
1902 .next = gfs2_sbstats_seq_next,
1903 .stop = gfs2_sbstats_seq_stop,
1904 .show = gfs2_sbstats_seq_show,
1905 };
1906
1907 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
1908
1909 static int gfs2_glocks_open(struct inode *inode, struct file *file)
1910 {
1911 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1912 sizeof(struct gfs2_glock_iter));
1913 if (ret == 0) {
1914 struct seq_file *seq = file->private_data;
1915 struct gfs2_glock_iter *gi = seq->private;
1916
1917 gi->sdp = inode->i_private;
1918 gi->last_pos = 0;
1919 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
1920 if (seq->buf)
1921 seq->size = GFS2_SEQ_GOODSIZE;
1922 gi->gl = NULL;
1923 ret = rhashtable_walk_init(&gl_hash_table, &gi->hti, GFP_KERNEL);
1924 }
1925 return ret;
1926 }
1927
1928 static int gfs2_glocks_release(struct inode *inode, struct file *file)
1929 {
1930 struct seq_file *seq = file->private_data;
1931 struct gfs2_glock_iter *gi = seq->private;
1932
1933 gi->gl = NULL;
1934 rhashtable_walk_exit(&gi->hti);
1935 return seq_release_private(inode, file);
1936 }
1937
1938 static int gfs2_glstats_open(struct inode *inode, struct file *file)
1939 {
1940 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
1941 sizeof(struct gfs2_glock_iter));
1942 if (ret == 0) {
1943 struct seq_file *seq = file->private_data;
1944 struct gfs2_glock_iter *gi = seq->private;
1945 gi->sdp = inode->i_private;
1946 gi->last_pos = 0;
1947 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
1948 if (seq->buf)
1949 seq->size = GFS2_SEQ_GOODSIZE;
1950 gi->gl = NULL;
1951 ret = rhashtable_walk_init(&gl_hash_table, &gi->hti, GFP_KERNEL);
1952 }
1953 return ret;
1954 }
1955
1956 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
1957 {
1958 int ret = seq_open(file, &gfs2_sbstats_seq_ops);
1959 if (ret == 0) {
1960 struct seq_file *seq = file->private_data;
1961 seq->private = inode->i_private; /* sdp */
1962 }
1963 return ret;
1964 }
1965
1966 static const struct file_operations gfs2_glocks_fops = {
1967 .owner = THIS_MODULE,
1968 .open = gfs2_glocks_open,
1969 .read = seq_read,
1970 .llseek = seq_lseek,
1971 .release = gfs2_glocks_release,
1972 };
1973
1974 static const struct file_operations gfs2_glstats_fops = {
1975 .owner = THIS_MODULE,
1976 .open = gfs2_glstats_open,
1977 .read = seq_read,
1978 .llseek = seq_lseek,
1979 .release = gfs2_glocks_release,
1980 };
1981
1982 static const struct file_operations gfs2_sbstats_fops = {
1983 .owner = THIS_MODULE,
1984 .open = gfs2_sbstats_open,
1985 .read = seq_read,
1986 .llseek = seq_lseek,
1987 .release = seq_release,
1988 };
1989
1990 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1991 {
1992 struct dentry *dent;
1993
1994 dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1995 if (IS_ERR_OR_NULL(dent))
1996 goto fail;
1997 sdp->debugfs_dir = dent;
1998
1999 dent = debugfs_create_file("glocks",
2000 S_IFREG | S_IRUGO,
2001 sdp->debugfs_dir, sdp,
2002 &gfs2_glocks_fops);
2003 if (IS_ERR_OR_NULL(dent))
2004 goto fail;
2005 sdp->debugfs_dentry_glocks = dent;
2006
2007 dent = debugfs_create_file("glstats",
2008 S_IFREG | S_IRUGO,
2009 sdp->debugfs_dir, sdp,
2010 &gfs2_glstats_fops);
2011 if (IS_ERR_OR_NULL(dent))
2012 goto fail;
2013 sdp->debugfs_dentry_glstats = dent;
2014
2015 dent = debugfs_create_file("sbstats",
2016 S_IFREG | S_IRUGO,
2017 sdp->debugfs_dir, sdp,
2018 &gfs2_sbstats_fops);
2019 if (IS_ERR_OR_NULL(dent))
2020 goto fail;
2021 sdp->debugfs_dentry_sbstats = dent;
2022
2023 return 0;
2024 fail:
2025 gfs2_delete_debugfs_file(sdp);
2026 return dent ? PTR_ERR(dent) : -ENOMEM;
2027 }
2028
2029 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2030 {
2031 if (sdp->debugfs_dir) {
2032 if (sdp->debugfs_dentry_glocks) {
2033 debugfs_remove(sdp->debugfs_dentry_glocks);
2034 sdp->debugfs_dentry_glocks = NULL;
2035 }
2036 if (sdp->debugfs_dentry_glstats) {
2037 debugfs_remove(sdp->debugfs_dentry_glstats);
2038 sdp->debugfs_dentry_glstats = NULL;
2039 }
2040 if (sdp->debugfs_dentry_sbstats) {
2041 debugfs_remove(sdp->debugfs_dentry_sbstats);
2042 sdp->debugfs_dentry_sbstats = NULL;
2043 }
2044 debugfs_remove(sdp->debugfs_dir);
2045 sdp->debugfs_dir = NULL;
2046 }
2047 }
2048
2049 int gfs2_register_debugfs(void)
2050 {
2051 gfs2_root = debugfs_create_dir("gfs2", NULL);
2052 if (IS_ERR(gfs2_root))
2053 return PTR_ERR(gfs2_root);
2054 return gfs2_root ? 0 : -ENOMEM;
2055 }
2056
2057 void gfs2_unregister_debugfs(void)
2058 {
2059 debugfs_remove(gfs2_root);
2060 gfs2_root = NULL;
2061 }
Linux with added FPC-III support