projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
NFSD: cleanup unneeded including linux/export.h
[deliverable/linux.git] / fs / gfs2 / glock.c
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
38 #include "gfs2.h"
39 #include "incore.h"
40 #include "glock.h"
41 #include "glops.h"
42 #include "inode.h"
43 #include "lops.h"
44 #include "meta_io.h"
45 #include "quota.h"
46 #include "super.h"
47 #include "util.h"
48 #include "bmap.h"
49 #define CREATE_TRACE_POINTS
50 #include "trace_gfs2.h"
51
52 struct gfs2_glock_iter {
53 int hash; /* hash bucket index */
54 unsigned nhash; /* Index within current bucket */
55 struct gfs2_sbd *sdp; /* incore superblock */
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 #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
74
75 static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE];
76 static struct dentry *gfs2_root;
77
78 /**
79 * gl_hash() - Turn glock number into hash bucket number
80 * @lock: The glock number
81 *
82 * Returns: The number of the corresponding hash bucket
83 */
84
85 static unsigned int gl_hash(const struct gfs2_sbd *sdp,
86 const struct lm_lockname *name)
87 {
88 unsigned int h;
89
90 h = jhash(&name->ln_number, sizeof(u64), 0);
91 h = jhash(&name->ln_type, sizeof(unsigned int), h);
92 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
93 h &= GFS2_GL_HASH_MASK;
94
95 return h;
96 }
97
98 static inline void spin_lock_bucket(unsigned int hash)
99 {
100 hlist_bl_lock(&gl_hash_table[hash]);
101 }
102
103 static inline void spin_unlock_bucket(unsigned int hash)
104 {
105 hlist_bl_unlock(&gl_hash_table[hash]);
106 }
107
108 static void gfs2_glock_dealloc(struct rcu_head *rcu)
109 {
110 struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
111
112 if (gl->gl_ops->go_flags & GLOF_ASPACE) {
113 kmem_cache_free(gfs2_glock_aspace_cachep, gl);
114 } else {
115 kfree(gl->gl_lksb.sb_lvbptr);
116 kmem_cache_free(gfs2_glock_cachep, gl);
117 }
118 }
119
120 void gfs2_glock_free(struct gfs2_glock *gl)
121 {
122 struct gfs2_sbd *sdp = gl->gl_sbd;
123
124 call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
125 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
126 wake_up(&sdp->sd_glock_wait);
127 }
128
129 /**
130 * gfs2_glock_hold() - increment reference count on glock
131 * @gl: The glock to hold
132 *
133 */
134
135 static void gfs2_glock_hold(struct gfs2_glock *gl)
136 {
137 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
138 lockref_get(&gl->gl_lockref);
139 }
140
141 /**
142 * demote_ok - Check to see if it's ok to unlock a glock
143 * @gl: the glock
144 *
145 * Returns: 1 if it's ok
146 */
147
148 static int demote_ok(const struct gfs2_glock *gl)
149 {
150 const struct gfs2_glock_operations *glops = gl->gl_ops;
151
152 if (gl->gl_state == LM_ST_UNLOCKED)
153 return 0;
154 if (!list_empty(&gl->gl_holders))
155 return 0;
156 if (glops->go_demote_ok)
157 return glops->go_demote_ok(gl);
158 return 1;
159 }
160
161
162 void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
163 {
164 spin_lock(&lru_lock);
165
166 if (!list_empty(&gl->gl_lru))
167 list_del_init(&gl->gl_lru);
168 else
169 atomic_inc(&lru_count);
170
171 list_add_tail(&gl->gl_lru, &lru_list);
172 set_bit(GLF_LRU, &gl->gl_flags);
173 spin_unlock(&lru_lock);
174 }
175
176 static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
177 {
178 if (!list_empty(&gl->gl_lru)) {
179 list_del_init(&gl->gl_lru);
180 atomic_dec(&lru_count);
181 clear_bit(GLF_LRU, &gl->gl_flags);
182 }
183 }
184
185 static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
186 {
187 spin_lock(&lru_lock);
188 __gfs2_glock_remove_from_lru(gl);
189 spin_unlock(&lru_lock);
190 }
191
192 /**
193 * gfs2_glock_put() - Decrement reference count on glock
194 * @gl: The glock to put
195 *
196 */
197
198 void gfs2_glock_put(struct gfs2_glock *gl)
199 {
200 struct gfs2_sbd *sdp = gl->gl_sbd;
201 struct address_space *mapping = gfs2_glock2aspace(gl);
202
203 if (lockref_put_or_lock(&gl->gl_lockref))
204 return;
205
206 lockref_mark_dead(&gl->gl_lockref);
207
208 spin_lock(&lru_lock);
209 __gfs2_glock_remove_from_lru(gl);
210 spin_unlock(&lru_lock);
211 spin_unlock(&gl->gl_lockref.lock);
212 spin_lock_bucket(gl->gl_hash);
213 hlist_bl_del_rcu(&gl->gl_list);
214 spin_unlock_bucket(gl->gl_hash);
215 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
216 GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
217 trace_gfs2_glock_put(gl);
218 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
219 }
220
221 /**
222 * search_bucket() - Find struct gfs2_glock by lock number
223 * @bucket: the bucket to search
224 * @name: The lock name
225 *
226 * Returns: NULL, or the struct gfs2_glock with the requested number
227 */
228
229 static struct gfs2_glock *search_bucket(unsigned int hash,
230 const struct gfs2_sbd *sdp,
231 const struct lm_lockname *name)
232 {
233 struct gfs2_glock *gl;
234 struct hlist_bl_node *h;
235
236 hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
237 if (!lm_name_equal(&gl->gl_name, name))
238 continue;
239 if (gl->gl_sbd != sdp)
240 continue;
241 if (lockref_get_not_dead(&gl->gl_lockref))
242 return gl;
243 }
244
245 return NULL;
246 }
247
248 /**
249 * may_grant - check if its ok to grant a new lock
250 * @gl: The glock
251 * @gh: The lock request which we wish to grant
252 *
253 * Returns: true if its ok to grant the lock
254 */
255
256 static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
257 {
258 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
259 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
260 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
261 return 0;
262 if (gl->gl_state == gh->gh_state)
263 return 1;
264 if (gh->gh_flags & GL_EXACT)
265 return 0;
266 if (gl->gl_state == LM_ST_EXCLUSIVE) {
267 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
268 return 1;
269 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
270 return 1;
271 }
272 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
273 return 1;
274 return 0;
275 }
276
277 static void gfs2_holder_wake(struct gfs2_holder *gh)
278 {
279 clear_bit(HIF_WAIT, &gh->gh_iflags);
280 smp_mb__after_clear_bit();
281 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
282 }
283
284 /**
285 * do_error - Something unexpected has happened during a lock request
286 *
287 */
288
289 static inline void do_error(struct gfs2_glock *gl, const int ret)
290 {
291 struct gfs2_holder *gh, *tmp;
292
293 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
294 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
295 continue;
296 if (ret & LM_OUT_ERROR)
297 gh->gh_error = -EIO;
298 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
299 gh->gh_error = GLR_TRYFAILED;
300 else
301 continue;
302 list_del_init(&gh->gh_list);
303 trace_gfs2_glock_queue(gh, 0);
304 gfs2_holder_wake(gh);
305 }
306 }
307
308 /**
309 * do_promote - promote as many requests as possible on the current queue
310 * @gl: The glock
311 *
312 * Returns: 1 if there is a blocked holder at the head of the list, or 2
313 * if a type specific operation is underway.
314 */
315
316 static int do_promote(struct gfs2_glock *gl)
317 __releases(&gl->gl_spin)
318 __acquires(&gl->gl_spin)
319 {
320 const struct gfs2_glock_operations *glops = gl->gl_ops;
321 struct gfs2_holder *gh, *tmp;
322 int ret;
323
324 restart:
325 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
326 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
327 continue;
328 if (may_grant(gl, gh)) {
329 if (gh->gh_list.prev == &gl->gl_holders &&
330 glops->go_lock) {
331 spin_unlock(&gl->gl_spin);
332 /* FIXME: eliminate this eventually */
333 ret = glops->go_lock(gh);
334 spin_lock(&gl->gl_spin);
335 if (ret) {
336 if (ret == 1)
337 return 2;
338 gh->gh_error = ret;
339 list_del_init(&gh->gh_list);
340 trace_gfs2_glock_queue(gh, 0);
341 gfs2_holder_wake(gh);
342 goto restart;
343 }
344 set_bit(HIF_HOLDER, &gh->gh_iflags);
345 trace_gfs2_promote(gh, 1);
346 gfs2_holder_wake(gh);
347 goto restart;
348 }
349 set_bit(HIF_HOLDER, &gh->gh_iflags);
350 trace_gfs2_promote(gh, 0);
351 gfs2_holder_wake(gh);
352 continue;
353 }
354 if (gh->gh_list.prev == &gl->gl_holders)
355 return 1;
356 do_error(gl, 0);
357 break;
358 }
359 return 0;
360 }
361
362 /**
363 * find_first_waiter - find the first gh that's waiting for the glock
364 * @gl: the glock
365 */
366
367 static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
368 {
369 struct gfs2_holder *gh;
370
371 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
372 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
373 return gh;
374 }
375 return NULL;
376 }
377
378 /**
379 * state_change - record that the glock is now in a different state
380 * @gl: the glock
381 * @new_state the new state
382 *
383 */
384
385 static void state_change(struct gfs2_glock *gl, unsigned int new_state)
386 {
387 int held1, held2;
388
389 held1 = (gl->gl_state != LM_ST_UNLOCKED);
390 held2 = (new_state != LM_ST_UNLOCKED);
391
392 if (held1 != held2) {
393 GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
394 if (held2)
395 gl->gl_lockref.count++;
396 else
397 gl->gl_lockref.count--;
398 }
399 if (held1 && held2 && list_empty(&gl->gl_holders))
400 clear_bit(GLF_QUEUED, &gl->gl_flags);
401
402 if (new_state != gl->gl_target)
403 /* shorten our minimum hold time */
404 gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR,
405 GL_GLOCK_MIN_HOLD);
406 gl->gl_state = new_state;
407 gl->gl_tchange = jiffies;
408 }
409
410 static void gfs2_demote_wake(struct gfs2_glock *gl)
411 {
412 gl->gl_demote_state = LM_ST_EXCLUSIVE;
413 clear_bit(GLF_DEMOTE, &gl->gl_flags);
414 smp_mb__after_clear_bit();
415 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
416 }
417
418 /**
419 * finish_xmote - The DLM has replied to one of our lock requests
420 * @gl: The glock
421 * @ret: The status from the DLM
422 *
423 */
424
425 static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
426 {
427 const struct gfs2_glock_operations *glops = gl->gl_ops;
428 struct gfs2_holder *gh;
429 unsigned state = ret & LM_OUT_ST_MASK;
430 int rv;
431
432 spin_lock(&gl->gl_spin);
433 trace_gfs2_glock_state_change(gl, state);
434 state_change(gl, state);
435 gh = find_first_waiter(gl);
436
437 /* Demote to UN request arrived during demote to SH or DF */
438 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
439 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
440 gl->gl_target = LM_ST_UNLOCKED;
441
442 /* Check for state != intended state */
443 if (unlikely(state != gl->gl_target)) {
444 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
445 /* move to back of queue and try next entry */
446 if (ret & LM_OUT_CANCELED) {
447 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
448 list_move_tail(&gh->gh_list, &gl->gl_holders);
449 gh = find_first_waiter(gl);
450 gl->gl_target = gh->gh_state;
451 goto retry;
452 }
453 /* Some error or failed "try lock" - report it */
454 if ((ret & LM_OUT_ERROR) ||
455 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
456 gl->gl_target = gl->gl_state;
457 do_error(gl, ret);
458 goto out;
459 }
460 }
461 switch(state) {
462 /* Unlocked due to conversion deadlock, try again */
463 case LM_ST_UNLOCKED:
464 retry:
465 do_xmote(gl, gh, gl->gl_target);
466 break;
467 /* Conversion fails, unlock and try again */
468 case LM_ST_SHARED:
469 case LM_ST_DEFERRED:
470 do_xmote(gl, gh, LM_ST_UNLOCKED);
471 break;
472 default: /* Everything else */
473 pr_err("wanted %u got %u\n", gl->gl_target, state);
474 GLOCK_BUG_ON(gl, 1);
475 }
476 spin_unlock(&gl->gl_spin);
477 return;
478 }
479
480 /* Fast path - we got what we asked for */
481 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
482 gfs2_demote_wake(gl);
483 if (state != LM_ST_UNLOCKED) {
484 if (glops->go_xmote_bh) {
485 spin_unlock(&gl->gl_spin);
486 rv = glops->go_xmote_bh(gl, gh);
487 spin_lock(&gl->gl_spin);
488 if (rv) {
489 do_error(gl, rv);
490 goto out;
491 }
492 }
493 rv = do_promote(gl);
494 if (rv == 2)
495 goto out_locked;
496 }
497 out:
498 clear_bit(GLF_LOCK, &gl->gl_flags);
499 out_locked:
500 spin_unlock(&gl->gl_spin);
501 }
502
503 /**
504 * do_xmote - Calls the DLM to change the state of a lock
505 * @gl: The lock state
506 * @gh: The holder (only for promotes)
507 * @target: The target lock state
508 *
509 */
510
511 static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
512 __releases(&gl->gl_spin)
513 __acquires(&gl->gl_spin)
514 {
515 const struct gfs2_glock_operations *glops = gl->gl_ops;
516 struct gfs2_sbd *sdp = gl->gl_sbd;
517 unsigned int lck_flags = gh ? gh->gh_flags : 0;
518 int ret;
519
520 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
521 LM_FLAG_PRIORITY);
522 GLOCK_BUG_ON(gl, gl->gl_state == target);
523 GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);
524 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
525 glops->go_inval) {
526 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
527 do_error(gl, 0); /* Fail queued try locks */
528 }
529 gl->gl_req = target;
530 set_bit(GLF_BLOCKING, &gl->gl_flags);
531 if ((gl->gl_req == LM_ST_UNLOCKED) ||
532 (gl->gl_state == LM_ST_EXCLUSIVE) ||
533 (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))
534 clear_bit(GLF_BLOCKING, &gl->gl_flags);
535 spin_unlock(&gl->gl_spin);
536 if (glops->go_sync)
537 glops->go_sync(gl);
538 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
539 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
540 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
541
542 gfs2_glock_hold(gl);
543 if (sdp->sd_lockstruct.ls_ops->lm_lock) {
544 /* lock_dlm */
545 ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags);
546 if (ret) {
547 pr_err("lm_lock ret %d\n", ret);
548 GLOCK_BUG_ON(gl, 1);
549 }
550 } else { /* lock_nolock */
551 finish_xmote(gl, target);
552 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
553 gfs2_glock_put(gl);
554 }
555
556 spin_lock(&gl->gl_spin);
557 }
558
559 /**
560 * find_first_holder - find the first "holder" gh
561 * @gl: the glock
562 */
563
564 static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
565 {
566 struct gfs2_holder *gh;
567
568 if (!list_empty(&gl->gl_holders)) {
569 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
570 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
571 return gh;
572 }
573 return NULL;
574 }
575
576 /**
577 * run_queue - do all outstanding tasks related to a glock
578 * @gl: The glock in question
579 * @nonblock: True if we must not block in run_queue
580 *
581 */
582
583 static void run_queue(struct gfs2_glock *gl, const int nonblock)
584 __releases(&gl->gl_spin)
585 __acquires(&gl->gl_spin)
586 {
587 struct gfs2_holder *gh = NULL;
588 int ret;
589
590 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
591 return;
592
593 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
594
595 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
596 gl->gl_demote_state != gl->gl_state) {
597 if (find_first_holder(gl))
598 goto out_unlock;
599 if (nonblock)
600 goto out_sched;
601 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
602 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
603 gl->gl_target = gl->gl_demote_state;
604 } else {
605 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
606 gfs2_demote_wake(gl);
607 ret = do_promote(gl);
608 if (ret == 0)
609 goto out_unlock;
610 if (ret == 2)
611 goto out;
612 gh = find_first_waiter(gl);
613 gl->gl_target = gh->gh_state;
614 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
615 do_error(gl, 0); /* Fail queued try locks */
616 }
617 do_xmote(gl, gh, gl->gl_target);
618 out:
619 return;
620
621 out_sched:
622 clear_bit(GLF_LOCK, &gl->gl_flags);
623 smp_mb__after_clear_bit();
624 gl->gl_lockref.count++;
625 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
626 gl->gl_lockref.count--;
627 return;
628
629 out_unlock:
630 clear_bit(GLF_LOCK, &gl->gl_flags);
631 smp_mb__after_clear_bit();
632 return;
633 }
634
635 static void delete_work_func(struct work_struct *work)
636 {
637 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
638 struct gfs2_sbd *sdp = gl->gl_sbd;
639 struct gfs2_inode *ip;
640 struct inode *inode;
641 u64 no_addr = gl->gl_name.ln_number;
642
643 ip = gl->gl_object;
644 /* Note: Unsafe to dereference ip as we don't hold right refs/locks */
645
646 if (ip)
647 inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
648 else
649 inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
650 if (inode && !IS_ERR(inode)) {
651 d_prune_aliases(inode);
652 iput(inode);
653 }
654 gfs2_glock_put(gl);
655 }
656
657 static void glock_work_func(struct work_struct *work)
658 {
659 unsigned long delay = 0;
660 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
661 int drop_ref = 0;
662
663 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
664 finish_xmote(gl, gl->gl_reply);
665 drop_ref = 1;
666 }
667 spin_lock(&gl->gl_spin);
668 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
669 gl->gl_state != LM_ST_UNLOCKED &&
670 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
671 unsigned long holdtime, now = jiffies;
672
673 holdtime = gl->gl_tchange + gl->gl_hold_time;
674 if (time_before(now, holdtime))
675 delay = holdtime - now;
676
677 if (!delay) {
678 clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags);
679 set_bit(GLF_DEMOTE, &gl->gl_flags);
680 }
681 }
682 run_queue(gl, 0);
683 spin_unlock(&gl->gl_spin);
684 if (!delay)
685 gfs2_glock_put(gl);
686 else {
687 if (gl->gl_name.ln_type != LM_TYPE_INODE)
688 delay = 0;
689 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
690 gfs2_glock_put(gl);
691 }
692 if (drop_ref)
693 gfs2_glock_put(gl);
694 }
695
696 /**
697 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
698 * @sdp: The GFS2 superblock
699 * @number: the lock number
700 * @glops: The glock_operations to use
701 * @create: If 0, don't create the glock if it doesn't exist
702 * @glp: the glock is returned here
703 *
704 * This does not lock a glock, just finds/creates structures for one.
705 *
706 * Returns: errno
707 */
708
709 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
710 const struct gfs2_glock_operations *glops, int create,
711 struct gfs2_glock **glp)
712 {
713 struct super_block *s = sdp->sd_vfs;
714 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
715 struct gfs2_glock *gl, *tmp;
716 unsigned int hash = gl_hash(sdp, &name);
717 struct address_space *mapping;
718 struct kmem_cache *cachep;
719
720 rcu_read_lock();
721 gl = search_bucket(hash, sdp, &name);
722 rcu_read_unlock();
723
724 *glp = gl;
725 if (gl)
726 return 0;
727 if (!create)
728 return -ENOENT;
729
730 if (glops->go_flags & GLOF_ASPACE)
731 cachep = gfs2_glock_aspace_cachep;
732 else
733 cachep = gfs2_glock_cachep;
734 gl = kmem_cache_alloc(cachep, GFP_KERNEL);
735 if (!gl)
736 return -ENOMEM;
737
738 memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb));
739
740 if (glops->go_flags & GLOF_LVB) {
741 gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_KERNEL);
742 if (!gl->gl_lksb.sb_lvbptr) {
743 kmem_cache_free(cachep, gl);
744 return -ENOMEM;
745 }
746 }
747
748 atomic_inc(&sdp->sd_glock_disposal);
749 gl->gl_sbd = sdp;
750 gl->gl_flags = 0;
751 gl->gl_name = name;
752 gl->gl_lockref.count = 1;
753 gl->gl_state = LM_ST_UNLOCKED;
754 gl->gl_target = LM_ST_UNLOCKED;
755 gl->gl_demote_state = LM_ST_EXCLUSIVE;
756 gl->gl_hash = hash;
757 gl->gl_ops = glops;
758 gl->gl_dstamp = ktime_set(0, 0);
759 preempt_disable();
760 /* We use the global stats to estimate the initial per-glock stats */
761 gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type];
762 preempt_enable();
763 gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0;
764 gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0;
765 gl->gl_tchange = jiffies;
766 gl->gl_object = NULL;
767 gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
768 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
769 INIT_WORK(&gl->gl_delete, delete_work_func);
770
771 mapping = gfs2_glock2aspace(gl);
772 if (mapping) {
773 mapping->a_ops = &gfs2_meta_aops;
774 mapping->host = s->s_bdev->bd_inode;
775 mapping->flags = 0;
776 mapping_set_gfp_mask(mapping, GFP_NOFS);
777 mapping->private_data = NULL;
778 mapping->backing_dev_info = s->s_bdi;
779 mapping->writeback_index = 0;
780 }
781
782 spin_lock_bucket(hash);
783 tmp = search_bucket(hash, sdp, &name);
784 if (tmp) {
785 spin_unlock_bucket(hash);
786 kfree(gl->gl_lksb.sb_lvbptr);
787 kmem_cache_free(cachep, gl);
788 atomic_dec(&sdp->sd_glock_disposal);
789 gl = tmp;
790 } else {
791 hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]);
792 spin_unlock_bucket(hash);
793 }
794
795 *glp = gl;
796
797 return 0;
798 }
799
800 /**
801 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
802 * @gl: the glock
803 * @state: the state we're requesting
804 * @flags: the modifier flags
805 * @gh: the holder structure
806 *
807 */
808
809 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
810 struct gfs2_holder *gh)
811 {
812 INIT_LIST_HEAD(&gh->gh_list);
813 gh->gh_gl = gl;
814 gh->gh_ip = (unsigned long)__builtin_return_address(0);
815 gh->gh_owner_pid = get_pid(task_pid(current));
816 gh->gh_state = state;
817 gh->gh_flags = flags;
818 gh->gh_error = 0;
819 gh->gh_iflags = 0;
820 gfs2_glock_hold(gl);
821 }
822
823 /**
824 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
825 * @state: the state we're requesting
826 * @flags: the modifier flags
827 * @gh: the holder structure
828 *
829 * Don't mess with the glock.
830 *
831 */
832
833 void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
834 {
835 gh->gh_state = state;
836 gh->gh_flags = flags;
837 gh->gh_iflags = 0;
838 gh->gh_ip = (unsigned long)__builtin_return_address(0);
839 if (gh->gh_owner_pid)
840 put_pid(gh->gh_owner_pid);
841 gh->gh_owner_pid = get_pid(task_pid(current));
842 }
843
844 /**
845 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
846 * @gh: the holder structure
847 *
848 */
849
850 void gfs2_holder_uninit(struct gfs2_holder *gh)
851 {
852 put_pid(gh->gh_owner_pid);
853 gfs2_glock_put(gh->gh_gl);
854 gh->gh_gl = NULL;
855 gh->gh_ip = 0;
856 }
857
858 /**
859 * gfs2_glock_holder_wait
860 * @word: unused
861 *
862 * This function and gfs2_glock_demote_wait both show up in the WCHAN
863 * field. Thus I've separated these otherwise identical functions in
864 * order to be more informative to the user.
865 */
866
867 static int gfs2_glock_holder_wait(void *word)
868 {
869 schedule();
870 return 0;
871 }
872
873 static int gfs2_glock_demote_wait(void *word)
874 {
875 schedule();
876 return 0;
877 }
878
879 /**
880 * gfs2_glock_wait - wait on a glock acquisition
881 * @gh: the glock holder
882 *
883 * Returns: 0 on success
884 */
885
886 int gfs2_glock_wait(struct gfs2_holder *gh)
887 {
888 unsigned long time1 = jiffies;
889
890 might_sleep();
891 wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
892 if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
893 /* Lengthen the minimum hold time. */
894 gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
895 GL_GLOCK_HOLD_INCR,
896 GL_GLOCK_MAX_HOLD);
897 return gh->gh_error;
898 }
899
900 /**
901 * handle_callback - process a demote request
902 * @gl: the glock
903 * @state: the state the caller wants us to change to
904 *
905 * There are only two requests that we are going to see in actual
906 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
907 */
908
909 static void handle_callback(struct gfs2_glock *gl, unsigned int state,
910 unsigned long delay, bool remote)
911 {
912 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
913
914 set_bit(bit, &gl->gl_flags);
915 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
916 gl->gl_demote_state = state;
917 gl->gl_demote_time = jiffies;
918 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
919 gl->gl_demote_state != state) {
920 gl->gl_demote_state = LM_ST_UNLOCKED;
921 }
922 if (gl->gl_ops->go_callback)
923 gl->gl_ops->go_callback(gl, remote);
924 trace_gfs2_demote_rq(gl, remote);
925 }
926
927 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
928 {
929 struct va_format vaf;
930 va_list args;
931
932 va_start(args, fmt);
933
934 if (seq) {
935 seq_vprintf(seq, fmt, args);
936 } else {
937 vaf.fmt = fmt;
938 vaf.va = &args;
939
940 pr_err("%pV", &vaf);
941 }
942
943 va_end(args);
944 }
945
946 /**
947 * add_to_queue - Add a holder to the wait queue (but look for recursion)
948 * @gh: the holder structure to add
949 *
950 * Eventually we should move the recursive locking trap to a
951 * debugging option or something like that. This is the fast
952 * path and needs to have the minimum number of distractions.
953 *
954 */
955
956 static inline void add_to_queue(struct gfs2_holder *gh)
957 __releases(&gl->gl_spin)
958 __acquires(&gl->gl_spin)
959 {
960 struct gfs2_glock *gl = gh->gh_gl;
961 struct gfs2_sbd *sdp = gl->gl_sbd;
962 struct list_head *insert_pt = NULL;
963 struct gfs2_holder *gh2;
964 int try_futile = 0;
965
966 BUG_ON(gh->gh_owner_pid == NULL);
967 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
968 BUG();
969
970 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
971 if (test_bit(GLF_LOCK, &gl->gl_flags))
972 try_futile = !may_grant(gl, gh);
973 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
974 goto fail;
975 }
976
977 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
978 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
979 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
980 goto trap_recursive;
981 if (try_futile &&
982 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
983 fail:
984 gh->gh_error = GLR_TRYFAILED;
985 gfs2_holder_wake(gh);
986 return;
987 }
988 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
989 continue;
990 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
991 insert_pt = &gh2->gh_list;
992 }
993 set_bit(GLF_QUEUED, &gl->gl_flags);
994 trace_gfs2_glock_queue(gh, 1);
995 gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT);
996 gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT);
997 if (likely(insert_pt == NULL)) {
998 list_add_tail(&gh->gh_list, &gl->gl_holders);
999 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
1000 goto do_cancel;
1001 return;
1002 }
1003 list_add_tail(&gh->gh_list, insert_pt);
1004 do_cancel:
1005 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
1006 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
1007 spin_unlock(&gl->gl_spin);
1008 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
1009 sdp->sd_lockstruct.ls_ops->lm_cancel(gl);
1010 spin_lock(&gl->gl_spin);
1011 }
1012 return;
1013
1014 trap_recursive:
1015 pr_err("original: %pSR\n", (void *)gh2->gh_ip);
1016 pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid));
1017 pr_err("lock type: %d req lock state : %d\n",
1018 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
1019 pr_err("new: %pSR\n", (void *)gh->gh_ip);
1020 pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid));
1021 pr_err("lock type: %d req lock state : %d\n",
1022 gh->gh_gl->gl_name.ln_type, gh->gh_state);
1023 gfs2_dump_glock(NULL, gl);
1024 BUG();
1025 }
1026
1027 /**
1028 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
1029 * @gh: the holder structure
1030 *
1031 * if (gh->gh_flags & GL_ASYNC), this never returns an error
1032 *
1033 * Returns: 0, GLR_TRYFAILED, or errno on failure
1034 */
1035
1036 int gfs2_glock_nq(struct gfs2_holder *gh)
1037 {
1038 struct gfs2_glock *gl = gh->gh_gl;
1039 struct gfs2_sbd *sdp = gl->gl_sbd;
1040 int error = 0;
1041
1042 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1043 return -EIO;
1044
1045 if (test_bit(GLF_LRU, &gl->gl_flags))
1046 gfs2_glock_remove_from_lru(gl);
1047
1048 spin_lock(&gl->gl_spin);
1049 add_to_queue(gh);
1050 if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
1051 test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
1052 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1053 gl->gl_lockref.count++;
1054 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1055 gl->gl_lockref.count--;
1056 }
1057 run_queue(gl, 1);
1058 spin_unlock(&gl->gl_spin);
1059
1060 if (!(gh->gh_flags & GL_ASYNC))
1061 error = gfs2_glock_wait(gh);
1062
1063 return error;
1064 }
1065
1066 /**
1067 * gfs2_glock_poll - poll to see if an async request has been completed
1068 * @gh: the holder
1069 *
1070 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
1071 */
1072
1073 int gfs2_glock_poll(struct gfs2_holder *gh)
1074 {
1075 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
1076 }
1077
1078 /**
1079 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
1080 * @gh: the glock holder
1081 *
1082 */
1083
1084 void gfs2_glock_dq(struct gfs2_holder *gh)
1085 {
1086 struct gfs2_glock *gl = gh->gh_gl;
1087 const struct gfs2_glock_operations *glops = gl->gl_ops;
1088 unsigned delay = 0;
1089 int fast_path = 0;
1090
1091 spin_lock(&gl->gl_spin);
1092 if (gh->gh_flags & GL_NOCACHE)
1093 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1094
1095 list_del_init(&gh->gh_list);
1096 if (find_first_holder(gl) == NULL) {
1097 if (glops->go_unlock) {
1098 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
1099 spin_unlock(&gl->gl_spin);
1100 glops->go_unlock(gh);
1101 spin_lock(&gl->gl_spin);
1102 clear_bit(GLF_LOCK, &gl->gl_flags);
1103 }
1104 if (list_empty(&gl->gl_holders) &&
1105 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1106 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1107 fast_path = 1;
1108 }
1109 if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
1110 gfs2_glock_add_to_lru(gl);
1111
1112 trace_gfs2_glock_queue(gh, 0);
1113 spin_unlock(&gl->gl_spin);
1114 if (likely(fast_path))
1115 return;
1116
1117 gfs2_glock_hold(gl);
1118 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1119 !test_bit(GLF_DEMOTE, &gl->gl_flags) &&
1120 gl->gl_name.ln_type == LM_TYPE_INODE)
1121 delay = gl->gl_hold_time;
1122 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1123 gfs2_glock_put(gl);
1124 }
1125
1126 void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1127 {
1128 struct gfs2_glock *gl = gh->gh_gl;
1129 gfs2_glock_dq(gh);
1130 might_sleep();
1131 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
1132 }
1133
1134 /**
1135 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1136 * @gh: the holder structure
1137 *
1138 */
1139
1140 void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1141 {
1142 gfs2_glock_dq(gh);
1143 gfs2_holder_uninit(gh);
1144 }
1145
1146 /**
1147 * gfs2_glock_nq_num - acquire a glock based on lock number
1148 * @sdp: the filesystem
1149 * @number: the lock number
1150 * @glops: the glock operations for the type of glock
1151 * @state: the state to acquire the glock in
1152 * @flags: modifier flags for the acquisition
1153 * @gh: the struct gfs2_holder
1154 *
1155 * Returns: errno
1156 */
1157
1158 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
1159 const struct gfs2_glock_operations *glops,
1160 unsigned int state, int flags, struct gfs2_holder *gh)
1161 {
1162 struct gfs2_glock *gl;
1163 int error;
1164
1165 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1166 if (!error) {
1167 error = gfs2_glock_nq_init(gl, state, flags, gh);
1168 gfs2_glock_put(gl);
1169 }
1170
1171 return error;
1172 }
1173
1174 /**
1175 * glock_compare - Compare two struct gfs2_glock structures for sorting
1176 * @arg_a: the first structure
1177 * @arg_b: the second structure
1178 *
1179 */
1180
1181 static int glock_compare(const void *arg_a, const void *arg_b)
1182 {
1183 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1184 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1185 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1186 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
1187
1188 if (a->ln_number > b->ln_number)
1189 return 1;
1190 if (a->ln_number < b->ln_number)
1191 return -1;
1192 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
1193 return 0;
1194 }
1195
1196 /**
1197 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1198 * @num_gh: the number of structures
1199 * @ghs: an array of struct gfs2_holder structures
1200 *
1201 * Returns: 0 on success (all glocks acquired),
1202 * errno on failure (no glocks acquired)
1203 */
1204
1205 static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1206 struct gfs2_holder **p)
1207 {
1208 unsigned int x;
1209 int error = 0;
1210
1211 for (x = 0; x < num_gh; x++)
1212 p[x] = &ghs[x];
1213
1214 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1215
1216 for (x = 0; x < num_gh; x++) {
1217 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1218
1219 error = gfs2_glock_nq(p[x]);
1220 if (error) {
1221 while (x--)
1222 gfs2_glock_dq(p[x]);
1223 break;
1224 }
1225 }
1226
1227 return error;
1228 }
1229
1230 /**
1231 * gfs2_glock_nq_m - acquire multiple glocks
1232 * @num_gh: the number of structures
1233 * @ghs: an array of struct gfs2_holder structures
1234 *
1235 *
1236 * Returns: 0 on success (all glocks acquired),
1237 * errno on failure (no glocks acquired)
1238 */
1239
1240 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1241 {
1242 struct gfs2_holder *tmp[4];
1243 struct gfs2_holder **pph = tmp;
1244 int error = 0;
1245
1246 switch(num_gh) {
1247 case 0:
1248 return 0;
1249 case 1:
1250 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1251 return gfs2_glock_nq(ghs);
1252 default:
1253 if (num_gh <= 4)
1254 break;
1255 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1256 if (!pph)
1257 return -ENOMEM;
1258 }
1259
1260 error = nq_m_sync(num_gh, ghs, pph);
1261
1262 if (pph != tmp)
1263 kfree(pph);
1264
1265 return error;
1266 }
1267
1268 /**
1269 * gfs2_glock_dq_m - release multiple glocks
1270 * @num_gh: the number of structures
1271 * @ghs: an array of struct gfs2_holder structures
1272 *
1273 */
1274
1275 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1276 {
1277 while (num_gh--)
1278 gfs2_glock_dq(&ghs[num_gh]);
1279 }
1280
1281 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
1282 {
1283 unsigned long delay = 0;
1284 unsigned long holdtime;
1285 unsigned long now = jiffies;
1286
1287 gfs2_glock_hold(gl);
1288 holdtime = gl->gl_tchange + gl->gl_hold_time;
1289 if (test_bit(GLF_QUEUED, &gl->gl_flags) &&
1290 gl->gl_name.ln_type == LM_TYPE_INODE) {
1291 if (time_before(now, holdtime))
1292 delay = holdtime - now;
1293 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1294 delay = gl->gl_hold_time;
1295 }
1296
1297 spin_lock(&gl->gl_spin);
1298 handle_callback(gl, state, delay, true);
1299 spin_unlock(&gl->gl_spin);
1300 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1301 gfs2_glock_put(gl);
1302 }
1303
1304 /**
1305 * gfs2_should_freeze - Figure out if glock should be frozen
1306 * @gl: The glock in question
1307 *
1308 * Glocks are not frozen if (a) the result of the dlm operation is
1309 * an error, (b) the locking operation was an unlock operation or
1310 * (c) if there is a "noexp" flagged request anywhere in the queue
1311 *
1312 * Returns: 1 if freezing should occur, 0 otherwise
1313 */
1314
1315 static int gfs2_should_freeze(const struct gfs2_glock *gl)
1316 {
1317 const struct gfs2_holder *gh;
1318
1319 if (gl->gl_reply & ~LM_OUT_ST_MASK)
1320 return 0;
1321 if (gl->gl_target == LM_ST_UNLOCKED)
1322 return 0;
1323
1324 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
1325 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
1326 continue;
1327 if (LM_FLAG_NOEXP & gh->gh_flags)
1328 return 0;
1329 }
1330
1331 return 1;
1332 }
1333
1334 /**
1335 * gfs2_glock_complete - Callback used by locking
1336 * @gl: Pointer to the glock
1337 * @ret: The return value from the dlm
1338 *
1339 * The gl_reply field is under the gl_spin lock so that it is ok
1340 * to use a bitfield shared with other glock state fields.
1341 */
1342
1343 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
1344 {
1345 struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
1346
1347 spin_lock(&gl->gl_spin);
1348 gl->gl_reply = ret;
1349
1350 if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
1351 if (gfs2_should_freeze(gl)) {
1352 set_bit(GLF_FROZEN, &gl->gl_flags);
1353 spin_unlock(&gl->gl_spin);
1354 return;
1355 }
1356 }
1357
1358 gl->gl_lockref.count++;
1359 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1360 spin_unlock(&gl->gl_spin);
1361
1362 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1363 gfs2_glock_put(gl);
1364 }
1365
1366 static int glock_cmp(void *priv, struct list_head *a, struct list_head *b)
1367 {
1368 struct gfs2_glock *gla, *glb;
1369
1370 gla = list_entry(a, struct gfs2_glock, gl_lru);
1371 glb = list_entry(b, struct gfs2_glock, gl_lru);
1372
1373 if (gla->gl_name.ln_number > glb->gl_name.ln_number)
1374 return 1;
1375 if (gla->gl_name.ln_number < glb->gl_name.ln_number)
1376 return -1;
1377
1378 return 0;
1379 }
1380
1381 /**
1382 * gfs2_dispose_glock_lru - Demote a list of glocks
1383 * @list: The list to dispose of
1384 *
1385 * Disposing of glocks may involve disk accesses, so that here we sort
1386 * the glocks by number (i.e. disk location of the inodes) so that if
1387 * there are any such accesses, they'll be sent in order (mostly).
1388 *
1389 * Must be called under the lru_lock, but may drop and retake this
1390 * lock. While the lru_lock is dropped, entries may vanish from the
1391 * list, but no new entries will appear on the list (since it is
1392 * private)
1393 */
1394
1395 static void gfs2_dispose_glock_lru(struct list_head *list)
1396 __releases(&lru_lock)
1397 __acquires(&lru_lock)
1398 {
1399 struct gfs2_glock *gl;
1400
1401 list_sort(NULL, list, glock_cmp);
1402
1403 while(!list_empty(list)) {
1404 gl = list_entry(list->next, struct gfs2_glock, gl_lru);
1405 list_del_init(&gl->gl_lru);
1406 if (!spin_trylock(&gl->gl_spin)) {
1407 list_add(&gl->gl_lru, &lru_list);
1408 atomic_inc(&lru_count);
1409 continue;
1410 }
1411 clear_bit(GLF_LRU, &gl->gl_flags);
1412 spin_unlock(&lru_lock);
1413 gl->gl_lockref.count++;
1414 if (demote_ok(gl))
1415 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1416 WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
1417 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1418 gl->gl_lockref.count--;
1419 spin_unlock(&gl->gl_spin);
1420 spin_lock(&lru_lock);
1421 }
1422 }
1423
1424 /**
1425 * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
1426 * @nr: The number of entries to scan
1427 *
1428 * This function selects the entries on the LRU which are able to
1429 * be demoted, and then kicks off the process by calling
1430 * gfs2_dispose_glock_lru() above.
1431 */
1432
1433 static long gfs2_scan_glock_lru(int nr)
1434 {
1435 struct gfs2_glock *gl;
1436 LIST_HEAD(skipped);
1437 LIST_HEAD(dispose);
1438 long freed = 0;
1439
1440 spin_lock(&lru_lock);
1441 while ((nr-- >= 0) && !list_empty(&lru_list)) {
1442 gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
1443
1444 /* Test for being demotable */
1445 if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
1446 list_move(&gl->gl_lru, &dispose);
1447 atomic_dec(&lru_count);
1448 freed++;
1449 continue;
1450 }
1451
1452 list_move(&gl->gl_lru, &skipped);
1453 }
1454 list_splice(&skipped, &lru_list);
1455 if (!list_empty(&dispose))
1456 gfs2_dispose_glock_lru(&dispose);
1457 spin_unlock(&lru_lock);
1458
1459 return freed;
1460 }
1461
1462 static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink,
1463 struct shrink_control *sc)
1464 {
1465 if (!(sc->gfp_mask & __GFP_FS))
1466 return SHRINK_STOP;
1467 return gfs2_scan_glock_lru(sc->nr_to_scan);
1468 }
1469
1470 static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink,
1471 struct shrink_control *sc)
1472 {
1473 return vfs_pressure_ratio(atomic_read(&lru_count));
1474 }
1475
1476 static struct shrinker glock_shrinker = {
1477 .seeks = DEFAULT_SEEKS,
1478 .count_objects = gfs2_glock_shrink_count,
1479 .scan_objects = gfs2_glock_shrink_scan,
1480 };
1481
1482 /**
1483 * examine_bucket - Call a function for glock in a hash bucket
1484 * @examiner: the function
1485 * @sdp: the filesystem
1486 * @bucket: the bucket
1487 *
1488 */
1489
1490 static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
1491 unsigned int hash)
1492 {
1493 struct gfs2_glock *gl;
1494 struct hlist_bl_head *head = &gl_hash_table[hash];
1495 struct hlist_bl_node *pos;
1496
1497 rcu_read_lock();
1498 hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
1499 if ((gl->gl_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref))
1500 examiner(gl);
1501 }
1502 rcu_read_unlock();
1503 cond_resched();
1504 }
1505
1506 static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
1507 {
1508 unsigned x;
1509
1510 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1511 examine_bucket(examiner, sdp, x);
1512 }
1513
1514
1515 /**
1516 * thaw_glock - thaw out a glock which has an unprocessed reply waiting
1517 * @gl: The glock to thaw
1518 *
1519 */
1520
1521 static void thaw_glock(struct gfs2_glock *gl)
1522 {
1523 if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
1524 goto out;
1525 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
1526 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
1527 out:
1528 gfs2_glock_put(gl);
1529 }
1530 }
1531
1532 /**
1533 * clear_glock - look at a glock and see if we can free it from glock cache
1534 * @gl: the glock to look at
1535 *
1536 */
1537
1538 static void clear_glock(struct gfs2_glock *gl)
1539 {
1540 gfs2_glock_remove_from_lru(gl);
1541
1542 spin_lock(&gl->gl_spin);
1543 if (gl->gl_state != LM_ST_UNLOCKED)
1544 handle_callback(gl, LM_ST_UNLOCKED, 0, false);
1545 spin_unlock(&gl->gl_spin);
1546 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1547 gfs2_glock_put(gl);
1548 }
1549
1550 /**
1551 * gfs2_glock_thaw - Thaw any frozen glocks
1552 * @sdp: The super block
1553 *
1554 */
1555
1556 void gfs2_glock_thaw(struct gfs2_sbd *sdp)
1557 {
1558 glock_hash_walk(thaw_glock, sdp);
1559 }
1560
1561 static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1562 {
1563 spin_lock(&gl->gl_spin);
1564 gfs2_dump_glock(seq, gl);
1565 spin_unlock(&gl->gl_spin);
1566 }
1567
1568 static void dump_glock_func(struct gfs2_glock *gl)
1569 {
1570 dump_glock(NULL, gl);
1571 }
1572
1573 /**
1574 * gfs2_gl_hash_clear - Empty out the glock hash table
1575 * @sdp: the filesystem
1576 * @wait: wait until it's all gone
1577 *
1578 * Called when unmounting the filesystem.
1579 */
1580
1581 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
1582 {
1583 set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
1584 flush_workqueue(glock_workqueue);
1585 glock_hash_walk(clear_glock, sdp);
1586 flush_workqueue(glock_workqueue);
1587 wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
1588 glock_hash_walk(dump_glock_func, sdp);
1589 }
1590
1591 void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
1592 {
1593 struct gfs2_glock *gl = ip->i_gl;
1594 int ret;
1595
1596 ret = gfs2_truncatei_resume(ip);
1597 gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
1598
1599 spin_lock(&gl->gl_spin);
1600 clear_bit(GLF_LOCK, &gl->gl_flags);
1601 run_queue(gl, 1);
1602 spin_unlock(&gl->gl_spin);
1603 }
1604
1605 static const char *state2str(unsigned state)
1606 {
1607 switch(state) {
1608 case LM_ST_UNLOCKED:
1609 return "UN";
1610 case LM_ST_SHARED:
1611 return "SH";
1612 case LM_ST_DEFERRED:
1613 return "DF";
1614 case LM_ST_EXCLUSIVE:
1615 return "EX";
1616 }
1617 return "??";
1618 }
1619
1620 static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1621 {
1622 char *p = buf;
1623 if (flags & LM_FLAG_TRY)
1624 *p++ = 't';
1625 if (flags & LM_FLAG_TRY_1CB)
1626 *p++ = 'T';
1627 if (flags & LM_FLAG_NOEXP)
1628 *p++ = 'e';
1629 if (flags & LM_FLAG_ANY)
1630 *p++ = 'A';
1631 if (flags & LM_FLAG_PRIORITY)
1632 *p++ = 'p';
1633 if (flags & GL_ASYNC)
1634 *p++ = 'a';
1635 if (flags & GL_EXACT)
1636 *p++ = 'E';
1637 if (flags & GL_NOCACHE)
1638 *p++ = 'c';
1639 if (test_bit(HIF_HOLDER, &iflags))
1640 *p++ = 'H';
1641 if (test_bit(HIF_WAIT, &iflags))
1642 *p++ = 'W';
1643 if (test_bit(HIF_FIRST, &iflags))
1644 *p++ = 'F';
1645 *p = 0;
1646 return buf;
1647 }
1648
1649 /**
1650 * dump_holder - print information about a glock holder
1651 * @seq: the seq_file struct
1652 * @gh: the glock holder
1653 *
1654 */
1655
1656 static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
1657 {
1658 struct task_struct *gh_owner = NULL;
1659 char flags_buf[32];
1660
1661 rcu_read_lock();
1662 if (gh->gh_owner_pid)
1663 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
1664 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n",
1665 state2str(gh->gh_state),
1666 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1667 gh->gh_error,
1668 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1669 gh_owner ? gh_owner->comm : "(ended)",
1670 (void *)gh->gh_ip);
1671 rcu_read_unlock();
1672 }
1673
1674 static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
1675 {
1676 const unsigned long *gflags = &gl->gl_flags;
1677 char *p = buf;
1678
1679 if (test_bit(GLF_LOCK, gflags))
1680 *p++ = 'l';
1681 if (test_bit(GLF_DEMOTE, gflags))
1682 *p++ = 'D';
1683 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1684 *p++ = 'd';
1685 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1686 *p++ = 'p';
1687 if (test_bit(GLF_DIRTY, gflags))
1688 *p++ = 'y';
1689 if (test_bit(GLF_LFLUSH, gflags))
1690 *p++ = 'f';
1691 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1692 *p++ = 'i';
1693 if (test_bit(GLF_REPLY_PENDING, gflags))
1694 *p++ = 'r';
1695 if (test_bit(GLF_INITIAL, gflags))
1696 *p++ = 'I';
1697 if (test_bit(GLF_FROZEN, gflags))
1698 *p++ = 'F';
1699 if (test_bit(GLF_QUEUED, gflags))
1700 *p++ = 'q';
1701 if (test_bit(GLF_LRU, gflags))
1702 *p++ = 'L';
1703 if (gl->gl_object)
1704 *p++ = 'o';
1705 if (test_bit(GLF_BLOCKING, gflags))
1706 *p++ = 'b';
1707 *p = 0;
1708 return buf;
1709 }
1710
1711 /**
1712 * gfs2_dump_glock - print information about a glock
1713 * @seq: The seq_file struct
1714 * @gl: the glock
1715 *
1716 * The file format is as follows:
1717 * One line per object, capital letters are used to indicate objects
1718 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1719 * other objects are indented by a single space and follow the glock to
1720 * which they are related. Fields are indicated by lower case letters
1721 * followed by a colon and the field value, except for strings which are in
1722 * [] so that its possible to see if they are composed of spaces for
1723 * example. The field's are n = number (id of the object), f = flags,
1724 * t = type, s = state, r = refcount, e = error, p = pid.
1725 *
1726 */
1727
1728 void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
1729 {
1730 const struct gfs2_glock_operations *glops = gl->gl_ops;
1731 unsigned long long dtime;
1732 const struct gfs2_holder *gh;
1733 char gflags_buf[32];
1734
1735 dtime = jiffies - gl->gl_demote_time;
1736 dtime *= 1000000/HZ; /* demote time in uSec */
1737 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1738 dtime = 0;
1739 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",
1740 state2str(gl->gl_state),
1741 gl->gl_name.ln_type,
1742 (unsigned long long)gl->gl_name.ln_number,
1743 gflags2str(gflags_buf, gl),
1744 state2str(gl->gl_target),
1745 state2str(gl->gl_demote_state), dtime,
1746 atomic_read(&gl->gl_ail_count),
1747 atomic_read(&gl->gl_revokes),
1748 (int)gl->gl_lockref.count, gl->gl_hold_time);
1749
1750 list_for_each_entry(gh, &gl->gl_holders, gh_list)
1751 dump_holder(seq, gh);
1752
1753 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1754 glops->go_dump(seq, gl);
1755 }
1756
1757 static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
1758 {
1759 struct gfs2_glock *gl = iter_ptr;
1760
1761 seq_printf(seq, "G: n:%u/%llx rtt:%lld/%lld rttb:%lld/%lld irt:%lld/%lld dcnt: %lld qcnt: %lld\n",
1762 gl->gl_name.ln_type,
1763 (unsigned long long)gl->gl_name.ln_number,
1764 (long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
1765 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
1766 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
1767 (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
1768 (long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
1769 (long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
1770 (long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
1771 (long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
1772 return 0;
1773 }
1774
1775 static const char *gfs2_gltype[] = {
1776 "type",
1777 "reserved",
1778 "nondisk",
1779 "inode",
1780 "rgrp",
1781 "meta",
1782 "iopen",
1783 "flock",
1784 "plock",
1785 "quota",
1786 "journal",
1787 };
1788
1789 static const char *gfs2_stype[] = {
1790 [GFS2_LKS_SRTT] = "srtt",
1791 [GFS2_LKS_SRTTVAR] = "srttvar",
1792 [GFS2_LKS_SRTTB] = "srttb",
1793 [GFS2_LKS_SRTTVARB] = "srttvarb",
1794 [GFS2_LKS_SIRT] = "sirt",
1795 [GFS2_LKS_SIRTVAR] = "sirtvar",
1796 [GFS2_LKS_DCOUNT] = "dlm",
1797 [GFS2_LKS_QCOUNT] = "queue",
1798 };
1799
1800 #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype))
1801
1802 static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
1803 {
1804 struct gfs2_glock_iter *gi = seq->private;
1805 struct gfs2_sbd *sdp = gi->sdp;
1806 unsigned index = gi->hash >> 3;
1807 unsigned subindex = gi->hash & 0x07;
1808 s64 value;
1809 int i;
1810
1811 if (index == 0 && subindex != 0)
1812 return 0;
1813
1814 seq_printf(seq, "%-10s %8s:", gfs2_gltype[index],
1815 (index == 0) ? "cpu": gfs2_stype[subindex]);
1816
1817 for_each_possible_cpu(i) {
1818 const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i);
1819 if (index == 0) {
1820 value = i;
1821 } else {
1822 value = lkstats->lkstats[index - 1].stats[subindex];
1823 }
1824 seq_printf(seq, " %15lld", (long long)value);
1825 }
1826 seq_putc(seq, '\n');
1827 return 0;
1828 }
1829
1830 int __init gfs2_glock_init(void)
1831 {
1832 unsigned i;
1833 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
1834 INIT_HLIST_BL_HEAD(&gl_hash_table[i]);
1835 }
1836
1837 glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
1838 WQ_HIGHPRI | WQ_FREEZABLE, 0);
1839 if (!glock_workqueue)
1840 return -ENOMEM;
1841 gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
1842 WQ_MEM_RECLAIM | WQ_FREEZABLE,
1843 0);
1844 if (!gfs2_delete_workqueue) {
1845 destroy_workqueue(glock_workqueue);
1846 return -ENOMEM;
1847 }
1848
1849 register_shrinker(&glock_shrinker);
1850
1851 return 0;
1852 }
1853
1854 void gfs2_glock_exit(void)
1855 {
1856 unregister_shrinker(&glock_shrinker);
1857 destroy_workqueue(glock_workqueue);
1858 destroy_workqueue(gfs2_delete_workqueue);
1859 }
1860
1861 static inline struct gfs2_glock *glock_hash_chain(unsigned hash)
1862 {
1863 return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]),
1864 struct gfs2_glock, gl_list);
1865 }
1866
1867 static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl)
1868 {
1869 return hlist_bl_entry(rcu_dereference(gl->gl_list.next),
1870 struct gfs2_glock, gl_list);
1871 }
1872
1873 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
1874 {
1875 struct gfs2_glock *gl;
1876
1877 do {
1878 gl = gi->gl;
1879 if (gl) {
1880 gi->gl = glock_hash_next(gl);
1881 gi->nhash++;
1882 } else {
1883 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1884 rcu_read_unlock();
1885 return 1;
1886 }
1887 gi->gl = glock_hash_chain(gi->hash);
1888 gi->nhash = 0;
1889 }
1890 while (gi->gl == NULL) {
1891 gi->hash++;
1892 if (gi->hash >= GFS2_GL_HASH_SIZE) {
1893 rcu_read_unlock();
1894 return 1;
1895 }
1896 gi->gl = glock_hash_chain(gi->hash);
1897 gi->nhash = 0;
1898 }
1899 /* Skip entries for other sb and dead entries */
1900 } while (gi->sdp != gi->gl->gl_sbd ||
1901 __lockref_is_dead(&gi->gl->gl_lockref));
1902
1903 return 0;
1904 }
1905
1906 static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
1907 {
1908 struct gfs2_glock_iter *gi = seq->private;
1909 loff_t n = *pos;
1910
1911 if (gi->last_pos <= *pos)
1912 n = gi->nhash + (*pos - gi->last_pos);
1913 else
1914 gi->hash = 0;
1915
1916 gi->nhash = 0;
1917 rcu_read_lock();
1918
1919 do {
1920 if (gfs2_glock_iter_next(gi))
1921 return NULL;
1922 } while (n--);
1923
1924 gi->last_pos = *pos;
1925 return gi->gl;
1926 }
1927
1928 static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
1929 loff_t *pos)
1930 {
1931 struct gfs2_glock_iter *gi = seq->private;
1932
1933 (*pos)++;
1934 gi->last_pos = *pos;
1935 if (gfs2_glock_iter_next(gi))
1936 return NULL;
1937
1938 return gi->gl;
1939 }
1940
1941 static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
1942 {
1943 struct gfs2_glock_iter *gi = seq->private;
1944
1945 if (gi->gl)
1946 rcu_read_unlock();
1947 gi->gl = NULL;
1948 }
1949
1950 static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
1951 {
1952 dump_glock(seq, iter_ptr);
1953 return 0;
1954 }
1955
1956 static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos)
1957 {
1958 struct gfs2_glock_iter *gi = seq->private;
1959
1960 gi->hash = *pos;
1961 if (*pos >= GFS2_NR_SBSTATS)
1962 return NULL;
1963 preempt_disable();
1964 return SEQ_START_TOKEN;
1965 }
1966
1967 static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr,
1968 loff_t *pos)
1969 {
1970 struct gfs2_glock_iter *gi = seq->private;
1971 (*pos)++;
1972 gi->hash++;
1973 if (gi->hash >= GFS2_NR_SBSTATS) {
1974 preempt_enable();
1975 return NULL;
1976 }
1977 return SEQ_START_TOKEN;
1978 }
1979
1980 static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr)
1981 {
1982 preempt_enable();
1983 }
1984
1985 static const struct seq_operations gfs2_glock_seq_ops = {
1986 .start = gfs2_glock_seq_start,
1987 .next = gfs2_glock_seq_next,
1988 .stop = gfs2_glock_seq_stop,
1989 .show = gfs2_glock_seq_show,
1990 };
1991
1992 static const struct seq_operations gfs2_glstats_seq_ops = {
1993 .start = gfs2_glock_seq_start,
1994 .next = gfs2_glock_seq_next,
1995 .stop = gfs2_glock_seq_stop,
1996 .show = gfs2_glstats_seq_show,
1997 };
1998
1999 static const struct seq_operations gfs2_sbstats_seq_ops = {
2000 .start = gfs2_sbstats_seq_start,
2001 .next = gfs2_sbstats_seq_next,
2002 .stop = gfs2_sbstats_seq_stop,
2003 .show = gfs2_sbstats_seq_show,
2004 };
2005
2006 #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL)
2007
2008 static int gfs2_glocks_open(struct inode *inode, struct file *file)
2009 {
2010 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
2011 sizeof(struct gfs2_glock_iter));
2012 if (ret == 0) {
2013 struct seq_file *seq = file->private_data;
2014 struct gfs2_glock_iter *gi = seq->private;
2015 gi->sdp = inode->i_private;
2016 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2017 if (seq->buf)
2018 seq->size = GFS2_SEQ_GOODSIZE;
2019 }
2020 return ret;
2021 }
2022
2023 static int gfs2_glstats_open(struct inode *inode, struct file *file)
2024 {
2025 int ret = seq_open_private(file, &gfs2_glstats_seq_ops,
2026 sizeof(struct gfs2_glock_iter));
2027 if (ret == 0) {
2028 struct seq_file *seq = file->private_data;
2029 struct gfs2_glock_iter *gi = seq->private;
2030 gi->sdp = inode->i_private;
2031 seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN);
2032 if (seq->buf)
2033 seq->size = GFS2_SEQ_GOODSIZE;
2034 }
2035 return ret;
2036 }
2037
2038 static int gfs2_sbstats_open(struct inode *inode, struct file *file)
2039 {
2040 int ret = seq_open_private(file, &gfs2_sbstats_seq_ops,
2041 sizeof(struct gfs2_glock_iter));
2042 if (ret == 0) {
2043 struct seq_file *seq = file->private_data;
2044 struct gfs2_glock_iter *gi = seq->private;
2045 gi->sdp = inode->i_private;
2046 }
2047 return ret;
2048 }
2049
2050 static const struct file_operations gfs2_glocks_fops = {
2051 .owner = THIS_MODULE,
2052 .open = gfs2_glocks_open,
2053 .read = seq_read,
2054 .llseek = seq_lseek,
2055 .release = seq_release_private,
2056 };
2057
2058 static const struct file_operations gfs2_glstats_fops = {
2059 .owner = THIS_MODULE,
2060 .open = gfs2_glstats_open,
2061 .read = seq_read,
2062 .llseek = seq_lseek,
2063 .release = seq_release_private,
2064 };
2065
2066 static const struct file_operations gfs2_sbstats_fops = {
2067 .owner = THIS_MODULE,
2068 .open = gfs2_sbstats_open,
2069 .read = seq_read,
2070 .llseek = seq_lseek,
2071 .release = seq_release_private,
2072 };
2073
2074 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
2075 {
2076 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
2077 if (!sdp->debugfs_dir)
2078 return -ENOMEM;
2079 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
2080 S_IFREG | S_IRUGO,
2081 sdp->debugfs_dir, sdp,
2082 &gfs2_glocks_fops);
2083 if (!sdp->debugfs_dentry_glocks)
2084 goto fail;
2085
2086 sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
2087 S_IFREG | S_IRUGO,
2088 sdp->debugfs_dir, sdp,
2089 &gfs2_glstats_fops);
2090 if (!sdp->debugfs_dentry_glstats)
2091 goto fail;
2092
2093 sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
2094 S_IFREG | S_IRUGO,
2095 sdp->debugfs_dir, sdp,
2096 &gfs2_sbstats_fops);
2097 if (!sdp->debugfs_dentry_sbstats)
2098 goto fail;
2099
2100 return 0;
2101 fail:
2102 gfs2_delete_debugfs_file(sdp);
2103 return -ENOMEM;
2104 }
2105
2106 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
2107 {
2108 if (sdp->debugfs_dir) {
2109 if (sdp->debugfs_dentry_glocks) {
2110 debugfs_remove(sdp->debugfs_dentry_glocks);
2111 sdp->debugfs_dentry_glocks = NULL;
2112 }
2113 if (sdp->debugfs_dentry_glstats) {
2114 debugfs_remove(sdp->debugfs_dentry_glstats);
2115 sdp->debugfs_dentry_glstats = NULL;
2116 }
2117 if (sdp->debugfs_dentry_sbstats) {
2118 debugfs_remove(sdp->debugfs_dentry_sbstats);
2119 sdp->debugfs_dentry_sbstats = NULL;
2120 }
2121 debugfs_remove(sdp->debugfs_dir);
2122 sdp->debugfs_dir = NULL;
2123 }
2124 }
2125
2126 int gfs2_register_debugfs(void)
2127 {
2128 gfs2_root = debugfs_create_dir("gfs2", NULL);
2129 return gfs2_root ? 0 : -ENOMEM;
2130 }
2131
2132 void gfs2_unregister_debugfs(void)
2133 {
2134 debugfs_remove(gfs2_root);
2135 gfs2_root = NULL;
2136 }
Linux kernel - Deliverables
This page took 0.114572 seconds and 5 git commands to generate.