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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 <linux/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 BIT(GFS2_GL_HASH_SHIFT) | |
73 | ||
74 | static struct rhashtable_params ht_parms = { | |
75 | .nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4, | |
76 | .key_len = offsetofend(struct lm_lockname, ln_type), | |
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 | static void gfs2_glock_dealloc(struct rcu_head *rcu) | |
84 | { | |
85 | struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); | |
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 | } | |
94 | ||
95 | void gfs2_glock_free(struct gfs2_glock *gl) | |
96 | { | |
97 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; | |
98 | ||
99 | call_rcu(&gl->gl_rcu, gfs2_glock_dealloc); | |
100 | if (atomic_dec_and_test(&sdp->sd_glock_disposal)) | |
101 | wake_up(&sdp->sd_glock_wait); | |
102 | } | |
103 | ||
104 | /** | |
105 | * gfs2_glock_hold() - increment reference count on glock | |
106 | * @gl: The glock to hold | |
107 | * | |
108 | */ | |
109 | ||
110 | static void gfs2_glock_hold(struct gfs2_glock *gl) | |
111 | { | |
112 | GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref)); | |
113 | lockref_get(&gl->gl_lockref); | |
114 | } | |
115 | ||
116 | /** | |
117 | * demote_ok - Check to see if it's ok to unlock a glock | |
118 | * @gl: the glock | |
119 | * | |
120 | * Returns: 1 if it's ok | |
121 | */ | |
122 | ||
123 | static int demote_ok(const struct gfs2_glock *gl) | |
124 | { | |
125 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
126 | ||
127 | if (gl->gl_state == LM_ST_UNLOCKED) | |
128 | return 0; | |
129 | if (!list_empty(&gl->gl_holders)) | |
130 | return 0; | |
131 | if (glops->go_demote_ok) | |
132 | return glops->go_demote_ok(gl); | |
133 | return 1; | |
134 | } | |
135 | ||
136 | ||
137 | void gfs2_glock_add_to_lru(struct gfs2_glock *gl) | |
138 | { | |
139 | spin_lock(&lru_lock); | |
140 | ||
141 | if (!list_empty(&gl->gl_lru)) | |
142 | list_del_init(&gl->gl_lru); | |
143 | else | |
144 | atomic_inc(&lru_count); | |
145 | ||
146 | list_add_tail(&gl->gl_lru, &lru_list); | |
147 | set_bit(GLF_LRU, &gl->gl_flags); | |
148 | spin_unlock(&lru_lock); | |
149 | } | |
150 | ||
151 | static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) | |
152 | { | |
153 | spin_lock(&lru_lock); | |
154 | if (!list_empty(&gl->gl_lru)) { | |
155 | list_del_init(&gl->gl_lru); | |
156 | atomic_dec(&lru_count); | |
157 | clear_bit(GLF_LRU, &gl->gl_flags); | |
158 | } | |
159 | spin_unlock(&lru_lock); | |
160 | } | |
161 | ||
162 | /* | |
163 | * Enqueue the glock on the work queue. Passes one glock reference on to the | |
164 | * work queue. | |
165 | */ | |
166 | static void __gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) { | |
167 | if (!queue_delayed_work(glock_workqueue, &gl->gl_work, delay)) { | |
168 | /* | |
169 | * We are holding the lockref spinlock, and the work was still | |
170 | * queued above. The queued work (glock_work_func) takes that | |
171 | * spinlock before dropping its glock reference(s), so it | |
172 | * cannot have dropped them in the meantime. | |
173 | */ | |
174 | GLOCK_BUG_ON(gl, gl->gl_lockref.count < 2); | |
175 | gl->gl_lockref.count--; | |
176 | } | |
177 | } | |
178 | ||
179 | static void gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) { | |
180 | spin_lock(&gl->gl_lockref.lock); | |
181 | __gfs2_glock_queue_work(gl, delay); | |
182 | spin_unlock(&gl->gl_lockref.lock); | |
183 | } | |
184 | ||
185 | static void __gfs2_glock_put(struct gfs2_glock *gl) | |
186 | { | |
187 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; | |
188 | struct address_space *mapping = gfs2_glock2aspace(gl); | |
189 | ||
190 | lockref_mark_dead(&gl->gl_lockref); | |
191 | ||
192 | gfs2_glock_remove_from_lru(gl); | |
193 | spin_unlock(&gl->gl_lockref.lock); | |
194 | rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms); | |
195 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); | |
196 | GLOCK_BUG_ON(gl, mapping && mapping->nrpages); | |
197 | trace_gfs2_glock_put(gl); | |
198 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); | |
199 | } | |
200 | ||
201 | /** | |
202 | * gfs2_glock_put() - Decrement reference count on glock | |
203 | * @gl: The glock to put | |
204 | * | |
205 | */ | |
206 | ||
207 | void gfs2_glock_put(struct gfs2_glock *gl) | |
208 | { | |
209 | if (lockref_put_or_lock(&gl->gl_lockref)) | |
210 | return; | |
211 | ||
212 | __gfs2_glock_put(gl); | |
213 | } | |
214 | ||
215 | /** | |
216 | * may_grant - check if its ok to grant a new lock | |
217 | * @gl: The glock | |
218 | * @gh: The lock request which we wish to grant | |
219 | * | |
220 | * Returns: true if its ok to grant the lock | |
221 | */ | |
222 | ||
223 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
224 | { | |
225 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
226 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
227 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
228 | return 0; | |
229 | if (gl->gl_state == gh->gh_state) | |
230 | return 1; | |
231 | if (gh->gh_flags & GL_EXACT) | |
232 | return 0; | |
233 | if (gl->gl_state == LM_ST_EXCLUSIVE) { | |
234 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
235 | return 1; | |
236 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
237 | return 1; | |
238 | } | |
239 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) | |
240 | return 1; | |
241 | return 0; | |
242 | } | |
243 | ||
244 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
245 | { | |
246 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
247 | smp_mb__after_atomic(); | |
248 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
249 | } | |
250 | ||
251 | /** | |
252 | * do_error - Something unexpected has happened during a lock request | |
253 | * | |
254 | */ | |
255 | ||
256 | static void do_error(struct gfs2_glock *gl, const int ret) | |
257 | { | |
258 | struct gfs2_holder *gh, *tmp; | |
259 | ||
260 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
261 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
262 | continue; | |
263 | if (ret & LM_OUT_ERROR) | |
264 | gh->gh_error = -EIO; | |
265 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
266 | gh->gh_error = GLR_TRYFAILED; | |
267 | else | |
268 | continue; | |
269 | list_del_init(&gh->gh_list); | |
270 | trace_gfs2_glock_queue(gh, 0); | |
271 | gfs2_holder_wake(gh); | |
272 | } | |
273 | } | |
274 | ||
275 | /** | |
276 | * do_promote - promote as many requests as possible on the current queue | |
277 | * @gl: The glock | |
278 | * | |
279 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 | |
280 | * if a type specific operation is underway. | |
281 | */ | |
282 | ||
283 | static int do_promote(struct gfs2_glock *gl) | |
284 | __releases(&gl->gl_lockref.lock) | |
285 | __acquires(&gl->gl_lockref.lock) | |
286 | { | |
287 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
288 | struct gfs2_holder *gh, *tmp; | |
289 | int ret; | |
290 | ||
291 | restart: | |
292 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
293 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
294 | continue; | |
295 | if (may_grant(gl, gh)) { | |
296 | if (gh->gh_list.prev == &gl->gl_holders && | |
297 | glops->go_lock) { | |
298 | spin_unlock(&gl->gl_lockref.lock); | |
299 | /* FIXME: eliminate this eventually */ | |
300 | ret = glops->go_lock(gh); | |
301 | spin_lock(&gl->gl_lockref.lock); | |
302 | if (ret) { | |
303 | if (ret == 1) | |
304 | return 2; | |
305 | gh->gh_error = ret; | |
306 | list_del_init(&gh->gh_list); | |
307 | trace_gfs2_glock_queue(gh, 0); | |
308 | gfs2_holder_wake(gh); | |
309 | goto restart; | |
310 | } | |
311 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
312 | trace_gfs2_promote(gh, 1); | |
313 | gfs2_holder_wake(gh); | |
314 | goto restart; | |
315 | } | |
316 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
317 | trace_gfs2_promote(gh, 0); | |
318 | gfs2_holder_wake(gh); | |
319 | continue; | |
320 | } | |
321 | if (gh->gh_list.prev == &gl->gl_holders) | |
322 | return 1; | |
323 | do_error(gl, 0); | |
324 | break; | |
325 | } | |
326 | return 0; | |
327 | } | |
328 | ||
329 | /** | |
330 | * find_first_waiter - find the first gh that's waiting for the glock | |
331 | * @gl: the glock | |
332 | */ | |
333 | ||
334 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
335 | { | |
336 | struct gfs2_holder *gh; | |
337 | ||
338 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
339 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
340 | return gh; | |
341 | } | |
342 | return NULL; | |
343 | } | |
344 | ||
345 | /** | |
346 | * state_change - record that the glock is now in a different state | |
347 | * @gl: the glock | |
348 | * @new_state the new state | |
349 | * | |
350 | */ | |
351 | ||
352 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
353 | { | |
354 | int held1, held2; | |
355 | ||
356 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
357 | held2 = (new_state != LM_ST_UNLOCKED); | |
358 | ||
359 | if (held1 != held2) { | |
360 | GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref)); | |
361 | if (held2) | |
362 | gl->gl_lockref.count++; | |
363 | else | |
364 | gl->gl_lockref.count--; | |
365 | } | |
366 | if (held1 && held2 && list_empty(&gl->gl_holders)) | |
367 | clear_bit(GLF_QUEUED, &gl->gl_flags); | |
368 | ||
369 | if (new_state != gl->gl_target) | |
370 | /* shorten our minimum hold time */ | |
371 | gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR, | |
372 | GL_GLOCK_MIN_HOLD); | |
373 | gl->gl_state = new_state; | |
374 | gl->gl_tchange = jiffies; | |
375 | } | |
376 | ||
377 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
378 | { | |
379 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
380 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
381 | smp_mb__after_atomic(); | |
382 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
383 | } | |
384 | ||
385 | /** | |
386 | * finish_xmote - The DLM has replied to one of our lock requests | |
387 | * @gl: The glock | |
388 | * @ret: The status from the DLM | |
389 | * | |
390 | */ | |
391 | ||
392 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
393 | { | |
394 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
395 | struct gfs2_holder *gh; | |
396 | unsigned state = ret & LM_OUT_ST_MASK; | |
397 | int rv; | |
398 | ||
399 | spin_lock(&gl->gl_lockref.lock); | |
400 | trace_gfs2_glock_state_change(gl, state); | |
401 | state_change(gl, state); | |
402 | gh = find_first_waiter(gl); | |
403 | ||
404 | /* Demote to UN request arrived during demote to SH or DF */ | |
405 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
406 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
407 | gl->gl_target = LM_ST_UNLOCKED; | |
408 | ||
409 | /* Check for state != intended state */ | |
410 | if (unlikely(state != gl->gl_target)) { | |
411 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
412 | /* move to back of queue and try next entry */ | |
413 | if (ret & LM_OUT_CANCELED) { | |
414 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
415 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
416 | gh = find_first_waiter(gl); | |
417 | gl->gl_target = gh->gh_state; | |
418 | goto retry; | |
419 | } | |
420 | /* Some error or failed "try lock" - report it */ | |
421 | if ((ret & LM_OUT_ERROR) || | |
422 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
423 | gl->gl_target = gl->gl_state; | |
424 | do_error(gl, ret); | |
425 | goto out; | |
426 | } | |
427 | } | |
428 | switch(state) { | |
429 | /* Unlocked due to conversion deadlock, try again */ | |
430 | case LM_ST_UNLOCKED: | |
431 | retry: | |
432 | do_xmote(gl, gh, gl->gl_target); | |
433 | break; | |
434 | /* Conversion fails, unlock and try again */ | |
435 | case LM_ST_SHARED: | |
436 | case LM_ST_DEFERRED: | |
437 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
438 | break; | |
439 | default: /* Everything else */ | |
440 | pr_err("wanted %u got %u\n", gl->gl_target, state); | |
441 | GLOCK_BUG_ON(gl, 1); | |
442 | } | |
443 | spin_unlock(&gl->gl_lockref.lock); | |
444 | return; | |
445 | } | |
446 | ||
447 | /* Fast path - we got what we asked for */ | |
448 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
449 | gfs2_demote_wake(gl); | |
450 | if (state != LM_ST_UNLOCKED) { | |
451 | if (glops->go_xmote_bh) { | |
452 | spin_unlock(&gl->gl_lockref.lock); | |
453 | rv = glops->go_xmote_bh(gl, gh); | |
454 | spin_lock(&gl->gl_lockref.lock); | |
455 | if (rv) { | |
456 | do_error(gl, rv); | |
457 | goto out; | |
458 | } | |
459 | } | |
460 | rv = do_promote(gl); | |
461 | if (rv == 2) | |
462 | goto out_locked; | |
463 | } | |
464 | out: | |
465 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
466 | out_locked: | |
467 | spin_unlock(&gl->gl_lockref.lock); | |
468 | } | |
469 | ||
470 | /** | |
471 | * do_xmote - Calls the DLM to change the state of a lock | |
472 | * @gl: The lock state | |
473 | * @gh: The holder (only for promotes) | |
474 | * @target: The target lock state | |
475 | * | |
476 | */ | |
477 | ||
478 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
479 | __releases(&gl->gl_lockref.lock) | |
480 | __acquires(&gl->gl_lockref.lock) | |
481 | { | |
482 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
483 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; | |
484 | unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0); | |
485 | int ret; | |
486 | ||
487 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) && | |
488 | target != LM_ST_UNLOCKED) | |
489 | return; | |
490 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
491 | LM_FLAG_PRIORITY); | |
492 | GLOCK_BUG_ON(gl, gl->gl_state == target); | |
493 | GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target); | |
494 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
495 | glops->go_inval) { | |
496 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
497 | do_error(gl, 0); /* Fail queued try locks */ | |
498 | } | |
499 | gl->gl_req = target; | |
500 | set_bit(GLF_BLOCKING, &gl->gl_flags); | |
501 | if ((gl->gl_req == LM_ST_UNLOCKED) || | |
502 | (gl->gl_state == LM_ST_EXCLUSIVE) || | |
503 | (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB))) | |
504 | clear_bit(GLF_BLOCKING, &gl->gl_flags); | |
505 | spin_unlock(&gl->gl_lockref.lock); | |
506 | if (glops->go_sync) | |
507 | glops->go_sync(gl); | |
508 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
509 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
510 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
511 | ||
512 | gfs2_glock_hold(gl); | |
513 | if (sdp->sd_lockstruct.ls_ops->lm_lock) { | |
514 | /* lock_dlm */ | |
515 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags); | |
516 | if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED && | |
517 | target == LM_ST_UNLOCKED && | |
518 | test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) { | |
519 | finish_xmote(gl, target); | |
520 | gfs2_glock_queue_work(gl, 0); | |
521 | } | |
522 | else if (ret) { | |
523 | pr_err("lm_lock ret %d\n", ret); | |
524 | GLOCK_BUG_ON(gl, !test_bit(SDF_SHUTDOWN, | |
525 | &sdp->sd_flags)); | |
526 | } | |
527 | } else { /* lock_nolock */ | |
528 | finish_xmote(gl, target); | |
529 | gfs2_glock_queue_work(gl, 0); | |
530 | } | |
531 | ||
532 | spin_lock(&gl->gl_lockref.lock); | |
533 | } | |
534 | ||
535 | /** | |
536 | * find_first_holder - find the first "holder" gh | |
537 | * @gl: the glock | |
538 | */ | |
539 | ||
540 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
541 | { | |
542 | struct gfs2_holder *gh; | |
543 | ||
544 | if (!list_empty(&gl->gl_holders)) { | |
545 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
546 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
547 | return gh; | |
548 | } | |
549 | return NULL; | |
550 | } | |
551 | ||
552 | /** | |
553 | * run_queue - do all outstanding tasks related to a glock | |
554 | * @gl: The glock in question | |
555 | * @nonblock: True if we must not block in run_queue | |
556 | * | |
557 | */ | |
558 | ||
559 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
560 | __releases(&gl->gl_lockref.lock) | |
561 | __acquires(&gl->gl_lockref.lock) | |
562 | { | |
563 | struct gfs2_holder *gh = NULL; | |
564 | int ret; | |
565 | ||
566 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
567 | return; | |
568 | ||
569 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
570 | ||
571 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
572 | gl->gl_demote_state != gl->gl_state) { | |
573 | if (find_first_holder(gl)) | |
574 | goto out_unlock; | |
575 | if (nonblock) | |
576 | goto out_sched; | |
577 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
578 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); | |
579 | gl->gl_target = gl->gl_demote_state; | |
580 | } else { | |
581 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
582 | gfs2_demote_wake(gl); | |
583 | ret = do_promote(gl); | |
584 | if (ret == 0) | |
585 | goto out_unlock; | |
586 | if (ret == 2) | |
587 | goto out; | |
588 | gh = find_first_waiter(gl); | |
589 | gl->gl_target = gh->gh_state; | |
590 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
591 | do_error(gl, 0); /* Fail queued try locks */ | |
592 | } | |
593 | do_xmote(gl, gh, gl->gl_target); | |
594 | out: | |
595 | return; | |
596 | ||
597 | out_sched: | |
598 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
599 | smp_mb__after_atomic(); | |
600 | gl->gl_lockref.count++; | |
601 | __gfs2_glock_queue_work(gl, 0); | |
602 | return; | |
603 | ||
604 | out_unlock: | |
605 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
606 | smp_mb__after_atomic(); | |
607 | return; | |
608 | } | |
609 | ||
610 | static void delete_work_func(struct work_struct *work) | |
611 | { | |
612 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); | |
613 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; | |
614 | struct inode *inode; | |
615 | u64 no_addr = gl->gl_name.ln_number; | |
616 | ||
617 | /* If someone's using this glock to create a new dinode, the block must | |
618 | have been freed by another node, then re-used, in which case our | |
619 | iopen callback is too late after the fact. Ignore it. */ | |
620 | if (test_bit(GLF_INODE_CREATING, &gl->gl_flags)) | |
621 | goto out; | |
622 | ||
623 | inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED); | |
624 | if (inode && !IS_ERR(inode)) { | |
625 | d_prune_aliases(inode); | |
626 | iput(inode); | |
627 | } | |
628 | out: | |
629 | gfs2_glock_put(gl); | |
630 | } | |
631 | ||
632 | static void glock_work_func(struct work_struct *work) | |
633 | { | |
634 | unsigned long delay = 0; | |
635 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); | |
636 | unsigned int drop_refs = 1; | |
637 | ||
638 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { | |
639 | finish_xmote(gl, gl->gl_reply); | |
640 | drop_refs++; | |
641 | } | |
642 | spin_lock(&gl->gl_lockref.lock); | |
643 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
644 | gl->gl_state != LM_ST_UNLOCKED && | |
645 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
646 | unsigned long holdtime, now = jiffies; | |
647 | ||
648 | holdtime = gl->gl_tchange + gl->gl_hold_time; | |
649 | if (time_before(now, holdtime)) | |
650 | delay = holdtime - now; | |
651 | ||
652 | if (!delay) { | |
653 | clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags); | |
654 | set_bit(GLF_DEMOTE, &gl->gl_flags); | |
655 | } | |
656 | } | |
657 | run_queue(gl, 0); | |
658 | if (delay) { | |
659 | /* Keep one glock reference for the work we requeue. */ | |
660 | drop_refs--; | |
661 | if (gl->gl_name.ln_type != LM_TYPE_INODE) | |
662 | delay = 0; | |
663 | __gfs2_glock_queue_work(gl, delay); | |
664 | } | |
665 | ||
666 | /* | |
667 | * Drop the remaining glock references manually here. (Mind that | |
668 | * __gfs2_glock_queue_work depends on the lockref spinlock begin held | |
669 | * here as well.) | |
670 | */ | |
671 | gl->gl_lockref.count -= drop_refs; | |
672 | if (!gl->gl_lockref.count) { | |
673 | __gfs2_glock_put(gl); | |
674 | return; | |
675 | } | |
676 | spin_unlock(&gl->gl_lockref.lock); | |
677 | } | |
678 | ||
679 | /** | |
680 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
681 | * @sdp: The GFS2 superblock | |
682 | * @number: the lock number | |
683 | * @glops: The glock_operations to use | |
684 | * @create: If 0, don't create the glock if it doesn't exist | |
685 | * @glp: the glock is returned here | |
686 | * | |
687 | * This does not lock a glock, just finds/creates structures for one. | |
688 | * | |
689 | * Returns: errno | |
690 | */ | |
691 | ||
692 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, | |
693 | const struct gfs2_glock_operations *glops, int create, | |
694 | struct gfs2_glock **glp) | |
695 | { | |
696 | struct super_block *s = sdp->sd_vfs; | |
697 | struct lm_lockname name = { .ln_number = number, | |
698 | .ln_type = glops->go_type, | |
699 | .ln_sbd = sdp }; | |
700 | struct gfs2_glock *gl, *tmp; | |
701 | struct address_space *mapping; | |
702 | struct kmem_cache *cachep; | |
703 | int ret = 0; | |
704 | ||
705 | rcu_read_lock(); | |
706 | gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms); | |
707 | if (gl && !lockref_get_not_dead(&gl->gl_lockref)) | |
708 | gl = NULL; | |
709 | rcu_read_unlock(); | |
710 | ||
711 | *glp = gl; | |
712 | if (gl) | |
713 | return 0; | |
714 | if (!create) | |
715 | return -ENOENT; | |
716 | ||
717 | if (glops->go_flags & GLOF_ASPACE) | |
718 | cachep = gfs2_glock_aspace_cachep; | |
719 | else | |
720 | cachep = gfs2_glock_cachep; | |
721 | gl = kmem_cache_alloc(cachep, GFP_NOFS); | |
722 | if (!gl) | |
723 | return -ENOMEM; | |
724 | ||
725 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
726 | ||
727 | if (glops->go_flags & GLOF_LVB) { | |
728 | gl->gl_lksb.sb_lvbptr = kzalloc(GFS2_MIN_LVB_SIZE, GFP_NOFS); | |
729 | if (!gl->gl_lksb.sb_lvbptr) { | |
730 | kmem_cache_free(cachep, gl); | |
731 | return -ENOMEM; | |
732 | } | |
733 | } | |
734 | ||
735 | atomic_inc(&sdp->sd_glock_disposal); | |
736 | gl->gl_node.next = NULL; | |
737 | gl->gl_flags = 0; | |
738 | gl->gl_name = name; | |
739 | gl->gl_lockref.count = 1; | |
740 | gl->gl_state = LM_ST_UNLOCKED; | |
741 | gl->gl_target = LM_ST_UNLOCKED; | |
742 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
743 | gl->gl_ops = glops; | |
744 | gl->gl_dstamp = 0; | |
745 | preempt_disable(); | |
746 | /* We use the global stats to estimate the initial per-glock stats */ | |
747 | gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type]; | |
748 | preempt_enable(); | |
749 | gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0; | |
750 | gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0; | |
751 | gl->gl_tchange = jiffies; | |
752 | gl->gl_object = NULL; | |
753 | gl->gl_hold_time = GL_GLOCK_DFT_HOLD; | |
754 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); | |
755 | INIT_WORK(&gl->gl_delete, delete_work_func); | |
756 | ||
757 | mapping = gfs2_glock2aspace(gl); | |
758 | if (mapping) { | |
759 | mapping->a_ops = &gfs2_meta_aops; | |
760 | mapping->host = s->s_bdev->bd_inode; | |
761 | mapping->flags = 0; | |
762 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
763 | mapping->private_data = NULL; | |
764 | mapping->writeback_index = 0; | |
765 | } | |
766 | ||
767 | again: | |
768 | rcu_read_lock(); | |
769 | tmp = rhashtable_lookup_get_insert_fast(&gl_hash_table, &gl->gl_node, | |
770 | ht_parms); | |
771 | if (!tmp) { | |
772 | *glp = gl; | |
773 | goto out; | |
774 | } | |
775 | if (IS_ERR(tmp)) { | |
776 | ret = PTR_ERR(tmp); | |
777 | goto out_free; | |
778 | } | |
779 | if (lockref_get_not_dead(&tmp->gl_lockref)) { | |
780 | *glp = tmp; | |
781 | goto out_free; | |
782 | } | |
783 | rcu_read_unlock(); | |
784 | cond_resched(); | |
785 | goto again; | |
786 | ||
787 | out_free: | |
788 | kfree(gl->gl_lksb.sb_lvbptr); | |
789 | kmem_cache_free(cachep, gl); | |
790 | atomic_dec(&sdp->sd_glock_disposal); | |
791 | ||
792 | out: | |
793 | rcu_read_unlock(); | |
794 | return ret; | |
795 | } | |
796 | ||
797 | /** | |
798 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
799 | * @gl: the glock | |
800 | * @state: the state we're requesting | |
801 | * @flags: the modifier flags | |
802 | * @gh: the holder structure | |
803 | * | |
804 | */ | |
805 | ||
806 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags, | |
807 | struct gfs2_holder *gh) | |
808 | { | |
809 | INIT_LIST_HEAD(&gh->gh_list); | |
810 | gh->gh_gl = gl; | |
811 | gh->gh_ip = _RET_IP_; | |
812 | gh->gh_owner_pid = get_pid(task_pid(current)); | |
813 | gh->gh_state = state; | |
814 | gh->gh_flags = flags; | |
815 | gh->gh_error = 0; | |
816 | gh->gh_iflags = 0; | |
817 | gfs2_glock_hold(gl); | |
818 | } | |
819 | ||
820 | /** | |
821 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
822 | * @state: the state we're requesting | |
823 | * @flags: the modifier flags | |
824 | * @gh: the holder structure | |
825 | * | |
826 | * Don't mess with the glock. | |
827 | * | |
828 | */ | |
829 | ||
830 | void gfs2_holder_reinit(unsigned int state, u16 flags, struct gfs2_holder *gh) | |
831 | { | |
832 | gh->gh_state = state; | |
833 | gh->gh_flags = flags; | |
834 | gh->gh_iflags = 0; | |
835 | gh->gh_ip = _RET_IP_; | |
836 | put_pid(gh->gh_owner_pid); | |
837 | gh->gh_owner_pid = get_pid(task_pid(current)); | |
838 | } | |
839 | ||
840 | /** | |
841 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
842 | * @gh: the holder structure | |
843 | * | |
844 | */ | |
845 | ||
846 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
847 | { | |
848 | put_pid(gh->gh_owner_pid); | |
849 | gfs2_glock_put(gh->gh_gl); | |
850 | gfs2_holder_mark_uninitialized(gh); | |
851 | gh->gh_ip = 0; | |
852 | } | |
853 | ||
854 | /** | |
855 | * gfs2_glock_wait - wait on a glock acquisition | |
856 | * @gh: the glock holder | |
857 | * | |
858 | * Returns: 0 on success | |
859 | */ | |
860 | ||
861 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
862 | { | |
863 | unsigned long time1 = jiffies; | |
864 | ||
865 | might_sleep(); | |
866 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE); | |
867 | if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */ | |
868 | /* Lengthen the minimum hold time. */ | |
869 | gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time + | |
870 | GL_GLOCK_HOLD_INCR, | |
871 | GL_GLOCK_MAX_HOLD); | |
872 | return gh->gh_error; | |
873 | } | |
874 | ||
875 | /** | |
876 | * handle_callback - process a demote request | |
877 | * @gl: the glock | |
878 | * @state: the state the caller wants us to change to | |
879 | * | |
880 | * There are only two requests that we are going to see in actual | |
881 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
882 | */ | |
883 | ||
884 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, | |
885 | unsigned long delay, bool remote) | |
886 | { | |
887 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; | |
888 | ||
889 | set_bit(bit, &gl->gl_flags); | |
890 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
891 | gl->gl_demote_state = state; | |
892 | gl->gl_demote_time = jiffies; | |
893 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && | |
894 | gl->gl_demote_state != state) { | |
895 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
896 | } | |
897 | if (gl->gl_ops->go_callback) | |
898 | gl->gl_ops->go_callback(gl, remote); | |
899 | trace_gfs2_demote_rq(gl, remote); | |
900 | } | |
901 | ||
902 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) | |
903 | { | |
904 | struct va_format vaf; | |
905 | va_list args; | |
906 | ||
907 | va_start(args, fmt); | |
908 | ||
909 | if (seq) { | |
910 | seq_vprintf(seq, fmt, args); | |
911 | } else { | |
912 | vaf.fmt = fmt; | |
913 | vaf.va = &args; | |
914 | ||
915 | pr_err("%pV", &vaf); | |
916 | } | |
917 | ||
918 | va_end(args); | |
919 | } | |
920 | ||
921 | /** | |
922 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
923 | * @gh: the holder structure to add | |
924 | * | |
925 | * Eventually we should move the recursive locking trap to a | |
926 | * debugging option or something like that. This is the fast | |
927 | * path and needs to have the minimum number of distractions. | |
928 | * | |
929 | */ | |
930 | ||
931 | static inline void add_to_queue(struct gfs2_holder *gh) | |
932 | __releases(&gl->gl_lockref.lock) | |
933 | __acquires(&gl->gl_lockref.lock) | |
934 | { | |
935 | struct gfs2_glock *gl = gh->gh_gl; | |
936 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; | |
937 | struct list_head *insert_pt = NULL; | |
938 | struct gfs2_holder *gh2; | |
939 | int try_futile = 0; | |
940 | ||
941 | BUG_ON(gh->gh_owner_pid == NULL); | |
942 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) | |
943 | BUG(); | |
944 | ||
945 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
946 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
947 | try_futile = !may_grant(gl, gh); | |
948 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
949 | goto fail; | |
950 | } | |
951 | ||
952 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
953 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
954 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
955 | goto trap_recursive; | |
956 | if (try_futile && | |
957 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
958 | fail: | |
959 | gh->gh_error = GLR_TRYFAILED; | |
960 | gfs2_holder_wake(gh); | |
961 | return; | |
962 | } | |
963 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) | |
964 | continue; | |
965 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
966 | insert_pt = &gh2->gh_list; | |
967 | } | |
968 | set_bit(GLF_QUEUED, &gl->gl_flags); | |
969 | trace_gfs2_glock_queue(gh, 1); | |
970 | gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT); | |
971 | gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT); | |
972 | if (likely(insert_pt == NULL)) { | |
973 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
974 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
975 | goto do_cancel; | |
976 | return; | |
977 | } | |
978 | list_add_tail(&gh->gh_list, insert_pt); | |
979 | do_cancel: | |
980 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
981 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
982 | spin_unlock(&gl->gl_lockref.lock); | |
983 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) | |
984 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); | |
985 | spin_lock(&gl->gl_lockref.lock); | |
986 | } | |
987 | return; | |
988 | ||
989 | trap_recursive: | |
990 | pr_err("original: %pSR\n", (void *)gh2->gh_ip); | |
991 | pr_err("pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
992 | pr_err("lock type: %d req lock state : %d\n", | |
993 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
994 | pr_err("new: %pSR\n", (void *)gh->gh_ip); | |
995 | pr_err("pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
996 | pr_err("lock type: %d req lock state : %d\n", | |
997 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
998 | gfs2_dump_glock(NULL, gl); | |
999 | BUG(); | |
1000 | } | |
1001 | ||
1002 | /** | |
1003 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1004 | * @gh: the holder structure | |
1005 | * | |
1006 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1007 | * | |
1008 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1009 | */ | |
1010 | ||
1011 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1012 | { | |
1013 | struct gfs2_glock *gl = gh->gh_gl; | |
1014 | struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; | |
1015 | int error = 0; | |
1016 | ||
1017 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) | |
1018 | return -EIO; | |
1019 | ||
1020 | if (test_bit(GLF_LRU, &gl->gl_flags)) | |
1021 | gfs2_glock_remove_from_lru(gl); | |
1022 | ||
1023 | spin_lock(&gl->gl_lockref.lock); | |
1024 | add_to_queue(gh); | |
1025 | if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) && | |
1026 | test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) { | |
1027 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); | |
1028 | gl->gl_lockref.count++; | |
1029 | __gfs2_glock_queue_work(gl, 0); | |
1030 | } | |
1031 | run_queue(gl, 1); | |
1032 | spin_unlock(&gl->gl_lockref.lock); | |
1033 | ||
1034 | if (!(gh->gh_flags & GL_ASYNC)) | |
1035 | error = gfs2_glock_wait(gh); | |
1036 | ||
1037 | return error; | |
1038 | } | |
1039 | ||
1040 | /** | |
1041 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1042 | * @gh: the holder | |
1043 | * | |
1044 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1045 | */ | |
1046 | ||
1047 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1048 | { | |
1049 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; | |
1050 | } | |
1051 | ||
1052 | /** | |
1053 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1054 | * @gh: the glock holder | |
1055 | * | |
1056 | */ | |
1057 | ||
1058 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1059 | { | |
1060 | struct gfs2_glock *gl = gh->gh_gl; | |
1061 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
1062 | unsigned delay = 0; | |
1063 | int fast_path = 0; | |
1064 | ||
1065 | spin_lock(&gl->gl_lockref.lock); | |
1066 | if (gh->gh_flags & GL_NOCACHE) | |
1067 | handle_callback(gl, LM_ST_UNLOCKED, 0, false); | |
1068 | ||
1069 | list_del_init(&gh->gh_list); | |
1070 | clear_bit(HIF_HOLDER, &gh->gh_iflags); | |
1071 | if (find_first_holder(gl) == NULL) { | |
1072 | if (glops->go_unlock) { | |
1073 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); | |
1074 | spin_unlock(&gl->gl_lockref.lock); | |
1075 | glops->go_unlock(gh); | |
1076 | spin_lock(&gl->gl_lockref.lock); | |
1077 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1078 | } | |
1079 | if (list_empty(&gl->gl_holders) && | |
1080 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1081 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1082 | fast_path = 1; | |
1083 | } | |
1084 | if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl) && | |
1085 | (glops->go_flags & GLOF_LRU)) | |
1086 | gfs2_glock_add_to_lru(gl); | |
1087 | ||
1088 | trace_gfs2_glock_queue(gh, 0); | |
1089 | if (unlikely(!fast_path)) { | |
1090 | gl->gl_lockref.count++; | |
1091 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1092 | !test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
1093 | gl->gl_name.ln_type == LM_TYPE_INODE) | |
1094 | delay = gl->gl_hold_time; | |
1095 | __gfs2_glock_queue_work(gl, delay); | |
1096 | } | |
1097 | spin_unlock(&gl->gl_lockref.lock); | |
1098 | } | |
1099 | ||
1100 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) | |
1101 | { | |
1102 | struct gfs2_glock *gl = gh->gh_gl; | |
1103 | gfs2_glock_dq(gh); | |
1104 | might_sleep(); | |
1105 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE); | |
1106 | } | |
1107 | ||
1108 | /** | |
1109 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1110 | * @gh: the holder structure | |
1111 | * | |
1112 | */ | |
1113 | ||
1114 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1115 | { | |
1116 | gfs2_glock_dq(gh); | |
1117 | gfs2_holder_uninit(gh); | |
1118 | } | |
1119 | ||
1120 | /** | |
1121 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1122 | * @sdp: the filesystem | |
1123 | * @number: the lock number | |
1124 | * @glops: the glock operations for the type of glock | |
1125 | * @state: the state to acquire the glock in | |
1126 | * @flags: modifier flags for the acquisition | |
1127 | * @gh: the struct gfs2_holder | |
1128 | * | |
1129 | * Returns: errno | |
1130 | */ | |
1131 | ||
1132 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, | |
1133 | const struct gfs2_glock_operations *glops, | |
1134 | unsigned int state, u16 flags, struct gfs2_holder *gh) | |
1135 | { | |
1136 | struct gfs2_glock *gl; | |
1137 | int error; | |
1138 | ||
1139 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1140 | if (!error) { | |
1141 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1142 | gfs2_glock_put(gl); | |
1143 | } | |
1144 | ||
1145 | return error; | |
1146 | } | |
1147 | ||
1148 | /** | |
1149 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1150 | * @arg_a: the first structure | |
1151 | * @arg_b: the second structure | |
1152 | * | |
1153 | */ | |
1154 | ||
1155 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1156 | { | |
1157 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; | |
1158 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1159 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1160 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
1161 | ||
1162 | if (a->ln_number > b->ln_number) | |
1163 | return 1; | |
1164 | if (a->ln_number < b->ln_number) | |
1165 | return -1; | |
1166 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); | |
1167 | return 0; | |
1168 | } | |
1169 | ||
1170 | /** | |
1171 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1172 | * @num_gh: the number of structures | |
1173 | * @ghs: an array of struct gfs2_holder structures | |
1174 | * | |
1175 | * Returns: 0 on success (all glocks acquired), | |
1176 | * errno on failure (no glocks acquired) | |
1177 | */ | |
1178 | ||
1179 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1180 | struct gfs2_holder **p) | |
1181 | { | |
1182 | unsigned int x; | |
1183 | int error = 0; | |
1184 | ||
1185 | for (x = 0; x < num_gh; x++) | |
1186 | p[x] = &ghs[x]; | |
1187 | ||
1188 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1189 | ||
1190 | for (x = 0; x < num_gh; x++) { | |
1191 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1192 | ||
1193 | error = gfs2_glock_nq(p[x]); | |
1194 | if (error) { | |
1195 | while (x--) | |
1196 | gfs2_glock_dq(p[x]); | |
1197 | break; | |
1198 | } | |
1199 | } | |
1200 | ||
1201 | return error; | |
1202 | } | |
1203 | ||
1204 | /** | |
1205 | * gfs2_glock_nq_m - acquire multiple glocks | |
1206 | * @num_gh: the number of structures | |
1207 | * @ghs: an array of struct gfs2_holder structures | |
1208 | * | |
1209 | * | |
1210 | * Returns: 0 on success (all glocks acquired), | |
1211 | * errno on failure (no glocks acquired) | |
1212 | */ | |
1213 | ||
1214 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1215 | { | |
1216 | struct gfs2_holder *tmp[4]; | |
1217 | struct gfs2_holder **pph = tmp; | |
1218 | int error = 0; | |
1219 | ||
1220 | switch(num_gh) { | |
1221 | case 0: | |
1222 | return 0; | |
1223 | case 1: | |
1224 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1225 | return gfs2_glock_nq(ghs); | |
1226 | default: | |
1227 | if (num_gh <= 4) | |
1228 | break; | |
1229 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); | |
1230 | if (!pph) | |
1231 | return -ENOMEM; | |
1232 | } | |
1233 | ||
1234 | error = nq_m_sync(num_gh, ghs, pph); | |
1235 | ||
1236 | if (pph != tmp) | |
1237 | kfree(pph); | |
1238 | ||
1239 | return error; | |
1240 | } | |
1241 | ||
1242 | /** | |
1243 | * gfs2_glock_dq_m - release multiple glocks | |
1244 | * @num_gh: the number of structures | |
1245 | * @ghs: an array of struct gfs2_holder structures | |
1246 | * | |
1247 | */ | |
1248 | ||
1249 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1250 | { | |
1251 | while (num_gh--) | |
1252 | gfs2_glock_dq(&ghs[num_gh]); | |
1253 | } | |
1254 | ||
1255 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) | |
1256 | { | |
1257 | unsigned long delay = 0; | |
1258 | unsigned long holdtime; | |
1259 | unsigned long now = jiffies; | |
1260 | ||
1261 | gfs2_glock_hold(gl); | |
1262 | holdtime = gl->gl_tchange + gl->gl_hold_time; | |
1263 | if (test_bit(GLF_QUEUED, &gl->gl_flags) && | |
1264 | gl->gl_name.ln_type == LM_TYPE_INODE) { | |
1265 | if (time_before(now, holdtime)) | |
1266 | delay = holdtime - now; | |
1267 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) | |
1268 | delay = gl->gl_hold_time; | |
1269 | } | |
1270 | ||
1271 | spin_lock(&gl->gl_lockref.lock); | |
1272 | handle_callback(gl, state, delay, true); | |
1273 | __gfs2_glock_queue_work(gl, delay); | |
1274 | spin_unlock(&gl->gl_lockref.lock); | |
1275 | } | |
1276 | ||
1277 | /** | |
1278 | * gfs2_should_freeze - Figure out if glock should be frozen | |
1279 | * @gl: The glock in question | |
1280 | * | |
1281 | * Glocks are not frozen if (a) the result of the dlm operation is | |
1282 | * an error, (b) the locking operation was an unlock operation or | |
1283 | * (c) if there is a "noexp" flagged request anywhere in the queue | |
1284 | * | |
1285 | * Returns: 1 if freezing should occur, 0 otherwise | |
1286 | */ | |
1287 | ||
1288 | static int gfs2_should_freeze(const struct gfs2_glock *gl) | |
1289 | { | |
1290 | const struct gfs2_holder *gh; | |
1291 | ||
1292 | if (gl->gl_reply & ~LM_OUT_ST_MASK) | |
1293 | return 0; | |
1294 | if (gl->gl_target == LM_ST_UNLOCKED) | |
1295 | return 0; | |
1296 | ||
1297 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
1298 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1299 | continue; | |
1300 | if (LM_FLAG_NOEXP & gh->gh_flags) | |
1301 | return 0; | |
1302 | } | |
1303 | ||
1304 | return 1; | |
1305 | } | |
1306 | ||
1307 | /** | |
1308 | * gfs2_glock_complete - Callback used by locking | |
1309 | * @gl: Pointer to the glock | |
1310 | * @ret: The return value from the dlm | |
1311 | * | |
1312 | * The gl_reply field is under the gl_lockref.lock lock so that it is ok | |
1313 | * to use a bitfield shared with other glock state fields. | |
1314 | */ | |
1315 | ||
1316 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) | |
1317 | { | |
1318 | struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct; | |
1319 | ||
1320 | spin_lock(&gl->gl_lockref.lock); | |
1321 | gl->gl_reply = ret; | |
1322 | ||
1323 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) { | |
1324 | if (gfs2_should_freeze(gl)) { | |
1325 | set_bit(GLF_FROZEN, &gl->gl_flags); | |
1326 | spin_unlock(&gl->gl_lockref.lock); | |
1327 | return; | |
1328 | } | |
1329 | } | |
1330 | ||
1331 | gl->gl_lockref.count++; | |
1332 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); | |
1333 | __gfs2_glock_queue_work(gl, 0); | |
1334 | spin_unlock(&gl->gl_lockref.lock); | |
1335 | } | |
1336 | ||
1337 | static int glock_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1338 | { | |
1339 | struct gfs2_glock *gla, *glb; | |
1340 | ||
1341 | gla = list_entry(a, struct gfs2_glock, gl_lru); | |
1342 | glb = list_entry(b, struct gfs2_glock, gl_lru); | |
1343 | ||
1344 | if (gla->gl_name.ln_number > glb->gl_name.ln_number) | |
1345 | return 1; | |
1346 | if (gla->gl_name.ln_number < glb->gl_name.ln_number) | |
1347 | return -1; | |
1348 | ||
1349 | return 0; | |
1350 | } | |
1351 | ||
1352 | /** | |
1353 | * gfs2_dispose_glock_lru - Demote a list of glocks | |
1354 | * @list: The list to dispose of | |
1355 | * | |
1356 | * Disposing of glocks may involve disk accesses, so that here we sort | |
1357 | * the glocks by number (i.e. disk location of the inodes) so that if | |
1358 | * there are any such accesses, they'll be sent in order (mostly). | |
1359 | * | |
1360 | * Must be called under the lru_lock, but may drop and retake this | |
1361 | * lock. While the lru_lock is dropped, entries may vanish from the | |
1362 | * list, but no new entries will appear on the list (since it is | |
1363 | * private) | |
1364 | */ | |
1365 | ||
1366 | static void gfs2_dispose_glock_lru(struct list_head *list) | |
1367 | __releases(&lru_lock) | |
1368 | __acquires(&lru_lock) | |
1369 | { | |
1370 | struct gfs2_glock *gl; | |
1371 | ||
1372 | list_sort(NULL, list, glock_cmp); | |
1373 | ||
1374 | while(!list_empty(list)) { | |
1375 | gl = list_entry(list->next, struct gfs2_glock, gl_lru); | |
1376 | list_del_init(&gl->gl_lru); | |
1377 | if (!spin_trylock(&gl->gl_lockref.lock)) { | |
1378 | add_back_to_lru: | |
1379 | list_add(&gl->gl_lru, &lru_list); | |
1380 | atomic_inc(&lru_count); | |
1381 | continue; | |
1382 | } | |
1383 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1384 | spin_unlock(&gl->gl_lockref.lock); | |
1385 | goto add_back_to_lru; | |
1386 | } | |
1387 | clear_bit(GLF_LRU, &gl->gl_flags); | |
1388 | gl->gl_lockref.count++; | |
1389 | if (demote_ok(gl)) | |
1390 | handle_callback(gl, LM_ST_UNLOCKED, 0, false); | |
1391 | WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags)); | |
1392 | __gfs2_glock_queue_work(gl, 0); | |
1393 | spin_unlock(&gl->gl_lockref.lock); | |
1394 | cond_resched_lock(&lru_lock); | |
1395 | } | |
1396 | } | |
1397 | ||
1398 | /** | |
1399 | * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote | |
1400 | * @nr: The number of entries to scan | |
1401 | * | |
1402 | * This function selects the entries on the LRU which are able to | |
1403 | * be demoted, and then kicks off the process by calling | |
1404 | * gfs2_dispose_glock_lru() above. | |
1405 | */ | |
1406 | ||
1407 | static long gfs2_scan_glock_lru(int nr) | |
1408 | { | |
1409 | struct gfs2_glock *gl; | |
1410 | LIST_HEAD(skipped); | |
1411 | LIST_HEAD(dispose); | |
1412 | long freed = 0; | |
1413 | ||
1414 | spin_lock(&lru_lock); | |
1415 | while ((nr-- >= 0) && !list_empty(&lru_list)) { | |
1416 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1417 | ||
1418 | /* Test for being demotable */ | |
1419 | if (!test_bit(GLF_LOCK, &gl->gl_flags)) { | |
1420 | list_move(&gl->gl_lru, &dispose); | |
1421 | atomic_dec(&lru_count); | |
1422 | freed++; | |
1423 | continue; | |
1424 | } | |
1425 | ||
1426 | list_move(&gl->gl_lru, &skipped); | |
1427 | } | |
1428 | list_splice(&skipped, &lru_list); | |
1429 | if (!list_empty(&dispose)) | |
1430 | gfs2_dispose_glock_lru(&dispose); | |
1431 | spin_unlock(&lru_lock); | |
1432 | ||
1433 | return freed; | |
1434 | } | |
1435 | ||
1436 | static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink, | |
1437 | struct shrink_control *sc) | |
1438 | { | |
1439 | if (!(sc->gfp_mask & __GFP_FS)) | |
1440 | return SHRINK_STOP; | |
1441 | return gfs2_scan_glock_lru(sc->nr_to_scan); | |
1442 | } | |
1443 | ||
1444 | static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink, | |
1445 | struct shrink_control *sc) | |
1446 | { | |
1447 | return vfs_pressure_ratio(atomic_read(&lru_count)); | |
1448 | } | |
1449 | ||
1450 | static struct shrinker glock_shrinker = { | |
1451 | .seeks = DEFAULT_SEEKS, | |
1452 | .count_objects = gfs2_glock_shrink_count, | |
1453 | .scan_objects = gfs2_glock_shrink_scan, | |
1454 | }; | |
1455 | ||
1456 | /** | |
1457 | * examine_bucket - Call a function for glock in a hash bucket | |
1458 | * @examiner: the function | |
1459 | * @sdp: the filesystem | |
1460 | * @bucket: the bucket | |
1461 | * | |
1462 | * Note that the function can be called multiple times on the same | |
1463 | * object. So the user must ensure that the function can cope with | |
1464 | * that. | |
1465 | */ | |
1466 | ||
1467 | static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) | |
1468 | { | |
1469 | struct gfs2_glock *gl; | |
1470 | struct rhashtable_iter iter; | |
1471 | ||
1472 | rhashtable_walk_enter(&gl_hash_table, &iter); | |
1473 | ||
1474 | do { | |
1475 | gl = ERR_PTR(rhashtable_walk_start(&iter)); | |
1476 | if (gl) | |
1477 | continue; | |
1478 | ||
1479 | while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl)) | |
1480 | if ((gl->gl_name.ln_sbd == sdp) && | |
1481 | lockref_get_not_dead(&gl->gl_lockref)) | |
1482 | examiner(gl); | |
1483 | ||
1484 | rhashtable_walk_stop(&iter); | |
1485 | } while (cond_resched(), gl == ERR_PTR(-EAGAIN)); | |
1486 | ||
1487 | rhashtable_walk_exit(&iter); | |
1488 | } | |
1489 | ||
1490 | /** | |
1491 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1492 | * @gl: The glock to thaw | |
1493 | * | |
1494 | */ | |
1495 | ||
1496 | static void thaw_glock(struct gfs2_glock *gl) | |
1497 | { | |
1498 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) { | |
1499 | gfs2_glock_put(gl); | |
1500 | return; | |
1501 | } | |
1502 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); | |
1503 | gfs2_glock_queue_work(gl, 0); | |
1504 | } | |
1505 | ||
1506 | /** | |
1507 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1508 | * @gl: the glock to look at | |
1509 | * | |
1510 | */ | |
1511 | ||
1512 | static void clear_glock(struct gfs2_glock *gl) | |
1513 | { | |
1514 | gfs2_glock_remove_from_lru(gl); | |
1515 | ||
1516 | spin_lock(&gl->gl_lockref.lock); | |
1517 | if (gl->gl_state != LM_ST_UNLOCKED) | |
1518 | handle_callback(gl, LM_ST_UNLOCKED, 0, false); | |
1519 | __gfs2_glock_queue_work(gl, 0); | |
1520 | spin_unlock(&gl->gl_lockref.lock); | |
1521 | } | |
1522 | ||
1523 | /** | |
1524 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1525 | * @sdp: The super block | |
1526 | * | |
1527 | */ | |
1528 | ||
1529 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1530 | { | |
1531 | glock_hash_walk(thaw_glock, sdp); | |
1532 | } | |
1533 | ||
1534 | static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl) | |
1535 | { | |
1536 | spin_lock(&gl->gl_lockref.lock); | |
1537 | gfs2_dump_glock(seq, gl); | |
1538 | spin_unlock(&gl->gl_lockref.lock); | |
1539 | } | |
1540 | ||
1541 | static void dump_glock_func(struct gfs2_glock *gl) | |
1542 | { | |
1543 | dump_glock(NULL, gl); | |
1544 | } | |
1545 | ||
1546 | /** | |
1547 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1548 | * @sdp: the filesystem | |
1549 | * @wait: wait until it's all gone | |
1550 | * | |
1551 | * Called when unmounting the filesystem. | |
1552 | */ | |
1553 | ||
1554 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) | |
1555 | { | |
1556 | set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags); | |
1557 | flush_workqueue(glock_workqueue); | |
1558 | glock_hash_walk(clear_glock, sdp); | |
1559 | flush_workqueue(glock_workqueue); | |
1560 | wait_event_timeout(sdp->sd_glock_wait, | |
1561 | atomic_read(&sdp->sd_glock_disposal) == 0, | |
1562 | HZ * 600); | |
1563 | glock_hash_walk(dump_glock_func, sdp); | |
1564 | } | |
1565 | ||
1566 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) | |
1567 | { | |
1568 | struct gfs2_glock *gl = ip->i_gl; | |
1569 | int ret; | |
1570 | ||
1571 | ret = gfs2_truncatei_resume(ip); | |
1572 | gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0); | |
1573 | ||
1574 | spin_lock(&gl->gl_lockref.lock); | |
1575 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1576 | run_queue(gl, 1); | |
1577 | spin_unlock(&gl->gl_lockref.lock); | |
1578 | } | |
1579 | ||
1580 | static const char *state2str(unsigned state) | |
1581 | { | |
1582 | switch(state) { | |
1583 | case LM_ST_UNLOCKED: | |
1584 | return "UN"; | |
1585 | case LM_ST_SHARED: | |
1586 | return "SH"; | |
1587 | case LM_ST_DEFERRED: | |
1588 | return "DF"; | |
1589 | case LM_ST_EXCLUSIVE: | |
1590 | return "EX"; | |
1591 | } | |
1592 | return "??"; | |
1593 | } | |
1594 | ||
1595 | static const char *hflags2str(char *buf, u16 flags, unsigned long iflags) | |
1596 | { | |
1597 | char *p = buf; | |
1598 | if (flags & LM_FLAG_TRY) | |
1599 | *p++ = 't'; | |
1600 | if (flags & LM_FLAG_TRY_1CB) | |
1601 | *p++ = 'T'; | |
1602 | if (flags & LM_FLAG_NOEXP) | |
1603 | *p++ = 'e'; | |
1604 | if (flags & LM_FLAG_ANY) | |
1605 | *p++ = 'A'; | |
1606 | if (flags & LM_FLAG_PRIORITY) | |
1607 | *p++ = 'p'; | |
1608 | if (flags & GL_ASYNC) | |
1609 | *p++ = 'a'; | |
1610 | if (flags & GL_EXACT) | |
1611 | *p++ = 'E'; | |
1612 | if (flags & GL_NOCACHE) | |
1613 | *p++ = 'c'; | |
1614 | if (test_bit(HIF_HOLDER, &iflags)) | |
1615 | *p++ = 'H'; | |
1616 | if (test_bit(HIF_WAIT, &iflags)) | |
1617 | *p++ = 'W'; | |
1618 | if (test_bit(HIF_FIRST, &iflags)) | |
1619 | *p++ = 'F'; | |
1620 | *p = 0; | |
1621 | return buf; | |
1622 | } | |
1623 | ||
1624 | /** | |
1625 | * dump_holder - print information about a glock holder | |
1626 | * @seq: the seq_file struct | |
1627 | * @gh: the glock holder | |
1628 | * | |
1629 | */ | |
1630 | ||
1631 | static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) | |
1632 | { | |
1633 | struct task_struct *gh_owner = NULL; | |
1634 | char flags_buf[32]; | |
1635 | ||
1636 | rcu_read_lock(); | |
1637 | if (gh->gh_owner_pid) | |
1638 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); | |
1639 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n", | |
1640 | state2str(gh->gh_state), | |
1641 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1642 | gh->gh_error, | |
1643 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1644 | gh_owner ? gh_owner->comm : "(ended)", | |
1645 | (void *)gh->gh_ip); | |
1646 | rcu_read_unlock(); | |
1647 | } | |
1648 | ||
1649 | static const char *gflags2str(char *buf, const struct gfs2_glock *gl) | |
1650 | { | |
1651 | const unsigned long *gflags = &gl->gl_flags; | |
1652 | char *p = buf; | |
1653 | ||
1654 | if (test_bit(GLF_LOCK, gflags)) | |
1655 | *p++ = 'l'; | |
1656 | if (test_bit(GLF_DEMOTE, gflags)) | |
1657 | *p++ = 'D'; | |
1658 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1659 | *p++ = 'd'; | |
1660 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1661 | *p++ = 'p'; | |
1662 | if (test_bit(GLF_DIRTY, gflags)) | |
1663 | *p++ = 'y'; | |
1664 | if (test_bit(GLF_LFLUSH, gflags)) | |
1665 | *p++ = 'f'; | |
1666 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1667 | *p++ = 'i'; | |
1668 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1669 | *p++ = 'r'; | |
1670 | if (test_bit(GLF_INITIAL, gflags)) | |
1671 | *p++ = 'I'; | |
1672 | if (test_bit(GLF_FROZEN, gflags)) | |
1673 | *p++ = 'F'; | |
1674 | if (test_bit(GLF_QUEUED, gflags)) | |
1675 | *p++ = 'q'; | |
1676 | if (test_bit(GLF_LRU, gflags)) | |
1677 | *p++ = 'L'; | |
1678 | if (gl->gl_object) | |
1679 | *p++ = 'o'; | |
1680 | if (test_bit(GLF_BLOCKING, gflags)) | |
1681 | *p++ = 'b'; | |
1682 | *p = 0; | |
1683 | return buf; | |
1684 | } | |
1685 | ||
1686 | /** | |
1687 | * gfs2_dump_glock - print information about a glock | |
1688 | * @seq: The seq_file struct | |
1689 | * @gl: the glock | |
1690 | * | |
1691 | * The file format is as follows: | |
1692 | * One line per object, capital letters are used to indicate objects | |
1693 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1694 | * other objects are indented by a single space and follow the glock to | |
1695 | * which they are related. Fields are indicated by lower case letters | |
1696 | * followed by a colon and the field value, except for strings which are in | |
1697 | * [] so that its possible to see if they are composed of spaces for | |
1698 | * example. The field's are n = number (id of the object), f = flags, | |
1699 | * t = type, s = state, r = refcount, e = error, p = pid. | |
1700 | * | |
1701 | */ | |
1702 | ||
1703 | void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) | |
1704 | { | |
1705 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
1706 | unsigned long long dtime; | |
1707 | const struct gfs2_holder *gh; | |
1708 | char gflags_buf[32]; | |
1709 | ||
1710 | dtime = jiffies - gl->gl_demote_time; | |
1711 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1712 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1713 | dtime = 0; | |
1714 | 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", | |
1715 | state2str(gl->gl_state), | |
1716 | gl->gl_name.ln_type, | |
1717 | (unsigned long long)gl->gl_name.ln_number, | |
1718 | gflags2str(gflags_buf, gl), | |
1719 | state2str(gl->gl_target), | |
1720 | state2str(gl->gl_demote_state), dtime, | |
1721 | atomic_read(&gl->gl_ail_count), | |
1722 | atomic_read(&gl->gl_revokes), | |
1723 | (int)gl->gl_lockref.count, gl->gl_hold_time); | |
1724 | ||
1725 | list_for_each_entry(gh, &gl->gl_holders, gh_list) | |
1726 | dump_holder(seq, gh); | |
1727 | ||
1728 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) | |
1729 | glops->go_dump(seq, gl); | |
1730 | } | |
1731 | ||
1732 | static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr) | |
1733 | { | |
1734 | struct gfs2_glock *gl = iter_ptr; | |
1735 | ||
1736 | seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n", | |
1737 | gl->gl_name.ln_type, | |
1738 | (unsigned long long)gl->gl_name.ln_number, | |
1739 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT], | |
1740 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR], | |
1741 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB], | |
1742 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB], | |
1743 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT], | |
1744 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR], | |
1745 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT], | |
1746 | (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]); | |
1747 | return 0; | |
1748 | } | |
1749 | ||
1750 | static const char *gfs2_gltype[] = { | |
1751 | "type", | |
1752 | "reserved", | |
1753 | "nondisk", | |
1754 | "inode", | |
1755 | "rgrp", | |
1756 | "meta", | |
1757 | "iopen", | |
1758 | "flock", | |
1759 | "plock", | |
1760 | "quota", | |
1761 | "journal", | |
1762 | }; | |
1763 | ||
1764 | static const char *gfs2_stype[] = { | |
1765 | [GFS2_LKS_SRTT] = "srtt", | |
1766 | [GFS2_LKS_SRTTVAR] = "srttvar", | |
1767 | [GFS2_LKS_SRTTB] = "srttb", | |
1768 | [GFS2_LKS_SRTTVARB] = "srttvarb", | |
1769 | [GFS2_LKS_SIRT] = "sirt", | |
1770 | [GFS2_LKS_SIRTVAR] = "sirtvar", | |
1771 | [GFS2_LKS_DCOUNT] = "dlm", | |
1772 | [GFS2_LKS_QCOUNT] = "queue", | |
1773 | }; | |
1774 | ||
1775 | #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype)) | |
1776 | ||
1777 | static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr) | |
1778 | { | |
1779 | struct gfs2_sbd *sdp = seq->private; | |
1780 | loff_t pos = *(loff_t *)iter_ptr; | |
1781 | unsigned index = pos >> 3; | |
1782 | unsigned subindex = pos & 0x07; | |
1783 | int i; | |
1784 | ||
1785 | if (index == 0 && subindex != 0) | |
1786 | return 0; | |
1787 | ||
1788 | seq_printf(seq, "%-10s %8s:", gfs2_gltype[index], | |
1789 | (index == 0) ? "cpu": gfs2_stype[subindex]); | |
1790 | ||
1791 | for_each_possible_cpu(i) { | |
1792 | const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i); | |
1793 | ||
1794 | if (index == 0) | |
1795 | seq_printf(seq, " %15u", i); | |
1796 | else | |
1797 | seq_printf(seq, " %15llu", (unsigned long long)lkstats-> | |
1798 | lkstats[index - 1].stats[subindex]); | |
1799 | } | |
1800 | seq_putc(seq, '\n'); | |
1801 | return 0; | |
1802 | } | |
1803 | ||
1804 | int __init gfs2_glock_init(void) | |
1805 | { | |
1806 | int ret; | |
1807 | ||
1808 | ret = rhashtable_init(&gl_hash_table, &ht_parms); | |
1809 | if (ret < 0) | |
1810 | return ret; | |
1811 | ||
1812 | glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | | |
1813 | WQ_HIGHPRI | WQ_FREEZABLE, 0); | |
1814 | if (!glock_workqueue) { | |
1815 | rhashtable_destroy(&gl_hash_table); | |
1816 | return -ENOMEM; | |
1817 | } | |
1818 | gfs2_delete_workqueue = alloc_workqueue("delete_workqueue", | |
1819 | WQ_MEM_RECLAIM | WQ_FREEZABLE, | |
1820 | 0); | |
1821 | if (!gfs2_delete_workqueue) { | |
1822 | destroy_workqueue(glock_workqueue); | |
1823 | rhashtable_destroy(&gl_hash_table); | |
1824 | return -ENOMEM; | |
1825 | } | |
1826 | ||
1827 | ret = register_shrinker(&glock_shrinker); | |
1828 | if (ret) { | |
1829 | destroy_workqueue(gfs2_delete_workqueue); | |
1830 | destroy_workqueue(glock_workqueue); | |
1831 | rhashtable_destroy(&gl_hash_table); | |
1832 | return ret; | |
1833 | } | |
1834 | ||
1835 | return 0; | |
1836 | } | |
1837 | ||
1838 | void gfs2_glock_exit(void) | |
1839 | { | |
1840 | unregister_shrinker(&glock_shrinker); | |
1841 | rhashtable_destroy(&gl_hash_table); | |
1842 | destroy_workqueue(glock_workqueue); | |
1843 | destroy_workqueue(gfs2_delete_workqueue); | |
1844 | } | |
1845 | ||
1846 | static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi) | |
1847 | { | |
1848 | while ((gi->gl = rhashtable_walk_next(&gi->hti))) { | |
1849 | if (IS_ERR(gi->gl)) { | |
1850 | if (PTR_ERR(gi->gl) == -EAGAIN) | |
1851 | continue; | |
1852 | gi->gl = NULL; | |
1853 | return; | |
1854 | } | |
1855 | /* Skip entries for other sb and dead entries */ | |
1856 | if (gi->sdp == gi->gl->gl_name.ln_sbd && | |
1857 | !__lockref_is_dead(&gi->gl->gl_lockref)) | |
1858 | return; | |
1859 | } | |
1860 | } | |
1861 | ||
1862 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) | |
1863 | { | |
1864 | struct gfs2_glock_iter *gi = seq->private; | |
1865 | loff_t n = *pos; | |
1866 | ||
1867 | rhashtable_walk_enter(&gl_hash_table, &gi->hti); | |
1868 | if (rhashtable_walk_start(&gi->hti) != 0) | |
1869 | return NULL; | |
1870 | ||
1871 | do { | |
1872 | gfs2_glock_iter_next(gi); | |
1873 | } while (gi->gl && n--); | |
1874 | ||
1875 | gi->last_pos = *pos; | |
1876 | ||
1877 | return gi->gl; | |
1878 | } | |
1879 | ||
1880 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, | |
1881 | loff_t *pos) | |
1882 | { | |
1883 | struct gfs2_glock_iter *gi = seq->private; | |
1884 | ||
1885 | (*pos)++; | |
1886 | gi->last_pos = *pos; | |
1887 | gfs2_glock_iter_next(gi); | |
1888 | ||
1889 | return gi->gl; | |
1890 | } | |
1891 | ||
1892 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) | |
1893 | { | |
1894 | struct gfs2_glock_iter *gi = seq->private; | |
1895 | ||
1896 | gi->gl = NULL; | |
1897 | rhashtable_walk_stop(&gi->hti); | |
1898 | rhashtable_walk_exit(&gi->hti); | |
1899 | } | |
1900 | ||
1901 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) | |
1902 | { | |
1903 | dump_glock(seq, iter_ptr); | |
1904 | return 0; | |
1905 | } | |
1906 | ||
1907 | static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos) | |
1908 | { | |
1909 | preempt_disable(); | |
1910 | if (*pos >= GFS2_NR_SBSTATS) | |
1911 | return NULL; | |
1912 | return pos; | |
1913 | } | |
1914 | ||
1915 | static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr, | |
1916 | loff_t *pos) | |
1917 | { | |
1918 | (*pos)++; | |
1919 | if (*pos >= GFS2_NR_SBSTATS) | |
1920 | return NULL; | |
1921 | return pos; | |
1922 | } | |
1923 | ||
1924 | static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr) | |
1925 | { | |
1926 | preempt_enable(); | |
1927 | } | |
1928 | ||
1929 | static const struct seq_operations gfs2_glock_seq_ops = { | |
1930 | .start = gfs2_glock_seq_start, | |
1931 | .next = gfs2_glock_seq_next, | |
1932 | .stop = gfs2_glock_seq_stop, | |
1933 | .show = gfs2_glock_seq_show, | |
1934 | }; | |
1935 | ||
1936 | static const struct seq_operations gfs2_glstats_seq_ops = { | |
1937 | .start = gfs2_glock_seq_start, | |
1938 | .next = gfs2_glock_seq_next, | |
1939 | .stop = gfs2_glock_seq_stop, | |
1940 | .show = gfs2_glstats_seq_show, | |
1941 | }; | |
1942 | ||
1943 | static const struct seq_operations gfs2_sbstats_seq_ops = { | |
1944 | .start = gfs2_sbstats_seq_start, | |
1945 | .next = gfs2_sbstats_seq_next, | |
1946 | .stop = gfs2_sbstats_seq_stop, | |
1947 | .show = gfs2_sbstats_seq_show, | |
1948 | }; | |
1949 | ||
1950 | #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL) | |
1951 | ||
1952 | static int __gfs2_glocks_open(struct inode *inode, struct file *file, | |
1953 | const struct seq_operations *ops) | |
1954 | { | |
1955 | int ret = seq_open_private(file, ops, sizeof(struct gfs2_glock_iter)); | |
1956 | if (ret == 0) { | |
1957 | struct seq_file *seq = file->private_data; | |
1958 | struct gfs2_glock_iter *gi = seq->private; | |
1959 | ||
1960 | gi->sdp = inode->i_private; | |
1961 | seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN); | |
1962 | if (seq->buf) | |
1963 | seq->size = GFS2_SEQ_GOODSIZE; | |
1964 | gi->gl = NULL; | |
1965 | } | |
1966 | return ret; | |
1967 | } | |
1968 | ||
1969 | static int gfs2_glocks_open(struct inode *inode, struct file *file) | |
1970 | { | |
1971 | return __gfs2_glocks_open(inode, file, &gfs2_glock_seq_ops); | |
1972 | } | |
1973 | ||
1974 | static int gfs2_glocks_release(struct inode *inode, struct file *file) | |
1975 | { | |
1976 | struct seq_file *seq = file->private_data; | |
1977 | struct gfs2_glock_iter *gi = seq->private; | |
1978 | ||
1979 | gi->gl = NULL; | |
1980 | return seq_release_private(inode, file); | |
1981 | } | |
1982 | ||
1983 | static int gfs2_glstats_open(struct inode *inode, struct file *file) | |
1984 | { | |
1985 | return __gfs2_glocks_open(inode, file, &gfs2_glstats_seq_ops); | |
1986 | } | |
1987 | ||
1988 | static int gfs2_sbstats_open(struct inode *inode, struct file *file) | |
1989 | { | |
1990 | int ret = seq_open(file, &gfs2_sbstats_seq_ops); | |
1991 | if (ret == 0) { | |
1992 | struct seq_file *seq = file->private_data; | |
1993 | seq->private = inode->i_private; /* sdp */ | |
1994 | } | |
1995 | return ret; | |
1996 | } | |
1997 | ||
1998 | static const struct file_operations gfs2_glocks_fops = { | |
1999 | .owner = THIS_MODULE, | |
2000 | .open = gfs2_glocks_open, | |
2001 | .read = seq_read, | |
2002 | .llseek = seq_lseek, | |
2003 | .release = gfs2_glocks_release, | |
2004 | }; | |
2005 | ||
2006 | static const struct file_operations gfs2_glstats_fops = { | |
2007 | .owner = THIS_MODULE, | |
2008 | .open = gfs2_glstats_open, | |
2009 | .read = seq_read, | |
2010 | .llseek = seq_lseek, | |
2011 | .release = gfs2_glocks_release, | |
2012 | }; | |
2013 | ||
2014 | static const struct file_operations gfs2_sbstats_fops = { | |
2015 | .owner = THIS_MODULE, | |
2016 | .open = gfs2_sbstats_open, | |
2017 | .read = seq_read, | |
2018 | .llseek = seq_lseek, | |
2019 | .release = seq_release, | |
2020 | }; | |
2021 | ||
2022 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
2023 | { | |
2024 | struct dentry *dent; | |
2025 | ||
2026 | dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root); | |
2027 | if (IS_ERR_OR_NULL(dent)) | |
2028 | goto fail; | |
2029 | sdp->debugfs_dir = dent; | |
2030 | ||
2031 | dent = debugfs_create_file("glocks", | |
2032 | S_IFREG | S_IRUGO, | |
2033 | sdp->debugfs_dir, sdp, | |
2034 | &gfs2_glocks_fops); | |
2035 | if (IS_ERR_OR_NULL(dent)) | |
2036 | goto fail; | |
2037 | sdp->debugfs_dentry_glocks = dent; | |
2038 | ||
2039 | dent = debugfs_create_file("glstats", | |
2040 | S_IFREG | S_IRUGO, | |
2041 | sdp->debugfs_dir, sdp, | |
2042 | &gfs2_glstats_fops); | |
2043 | if (IS_ERR_OR_NULL(dent)) | |
2044 | goto fail; | |
2045 | sdp->debugfs_dentry_glstats = dent; | |
2046 | ||
2047 | dent = debugfs_create_file("sbstats", | |
2048 | S_IFREG | S_IRUGO, | |
2049 | sdp->debugfs_dir, sdp, | |
2050 | &gfs2_sbstats_fops); | |
2051 | if (IS_ERR_OR_NULL(dent)) | |
2052 | goto fail; | |
2053 | sdp->debugfs_dentry_sbstats = dent; | |
2054 | ||
2055 | return 0; | |
2056 | fail: | |
2057 | gfs2_delete_debugfs_file(sdp); | |
2058 | return dent ? PTR_ERR(dent) : -ENOMEM; | |
2059 | } | |
2060 | ||
2061 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
2062 | { | |
2063 | if (sdp->debugfs_dir) { | |
2064 | if (sdp->debugfs_dentry_glocks) { | |
2065 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
2066 | sdp->debugfs_dentry_glocks = NULL; | |
2067 | } | |
2068 | if (sdp->debugfs_dentry_glstats) { | |
2069 | debugfs_remove(sdp->debugfs_dentry_glstats); | |
2070 | sdp->debugfs_dentry_glstats = NULL; | |
2071 | } | |
2072 | if (sdp->debugfs_dentry_sbstats) { | |
2073 | debugfs_remove(sdp->debugfs_dentry_sbstats); | |
2074 | sdp->debugfs_dentry_sbstats = NULL; | |
2075 | } | |
2076 | debugfs_remove(sdp->debugfs_dir); | |
2077 | sdp->debugfs_dir = NULL; | |
2078 | } | |
2079 | } | |
2080 | ||
2081 | int gfs2_register_debugfs(void) | |
2082 | { | |
2083 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
2084 | if (IS_ERR(gfs2_root)) | |
2085 | return PTR_ERR(gfs2_root); | |
2086 | return gfs2_root ? 0 : -ENOMEM; | |
2087 | } | |
2088 | ||
2089 | void gfs2_unregister_debugfs(void) | |
2090 | { | |
2091 | debugfs_remove(gfs2_root); | |
2092 | gfs2_root = NULL; | |
2093 | } |