Commit | Line | Data |
---|---|---|
b3b94faa DT |
1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
cf45b752 | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
b3b94faa DT |
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 | |
e9fc2aa0 | 7 | * of the GNU General Public License version 2. |
b3b94faa DT |
8 | */ |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/sort.h> | |
17 | #include <linux/jhash.h> | |
d0dc80db | 18 | #include <linux/kallsyms.h> |
5c676f6d | 19 | #include <linux/gfs2_ondisk.h> |
24264434 | 20 | #include <linux/list.h> |
7d308590 | 21 | #include <linux/lm_interface.h> |
fee852e3 | 22 | #include <linux/wait.h> |
95d97b7d | 23 | #include <linux/module.h> |
61be084e | 24 | #include <linux/rwsem.h> |
b3b94faa | 25 | #include <asm/uaccess.h> |
7c52b166 RP |
26 | #include <linux/seq_file.h> |
27 | #include <linux/debugfs.h> | |
8fbbfd21 SW |
28 | #include <linux/kthread.h> |
29 | #include <linux/freezer.h> | |
c4f68a13 BM |
30 | #include <linux/workqueue.h> |
31 | #include <linux/jiffies.h> | |
b3b94faa DT |
32 | |
33 | #include "gfs2.h" | |
5c676f6d | 34 | #include "incore.h" |
b3b94faa DT |
35 | #include "glock.h" |
36 | #include "glops.h" | |
37 | #include "inode.h" | |
b3b94faa DT |
38 | #include "lops.h" |
39 | #include "meta_io.h" | |
40 | #include "quota.h" | |
41 | #include "super.h" | |
5c676f6d | 42 | #include "util.h" |
813e0c46 | 43 | #include "bmap.h" |
b3b94faa | 44 | |
37b2fa6a | 45 | struct gfs2_gl_hash_bucket { |
b6397893 | 46 | struct hlist_head hb_list; |
37b2fa6a SW |
47 | }; |
48 | ||
6802e340 SW |
49 | struct gfs2_glock_iter { |
50 | int hash; /* hash bucket index */ | |
51 | struct gfs2_sbd *sdp; /* incore superblock */ | |
52 | struct gfs2_glock *gl; /* current glock struct */ | |
53 | char string[512]; /* scratch space */ | |
7c52b166 RP |
54 | }; |
55 | ||
b3b94faa DT |
56 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
57 | ||
08bc2dbc | 58 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); |
6802e340 SW |
59 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); |
60 | #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0) | |
61 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); | |
c4f68a13 | 62 | |
61be084e | 63 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
7c52b166 | 64 | static struct dentry *gfs2_root; |
8fbbfd21 SW |
65 | static struct task_struct *scand_process; |
66 | static unsigned int scand_secs = 5; | |
c4f68a13 | 67 | static struct workqueue_struct *glock_workqueue; |
08bc2dbc | 68 | |
b6397893 | 69 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
70 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
71 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
72 | ||
85d1da67 | 73 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 74 | static struct dentry *gfs2_root; |
087efdd3 SW |
75 | |
76 | /* | |
77 | * Despite what you might think, the numbers below are not arbitrary :-) | |
78 | * They are taken from the ipv4 routing hash code, which is well tested | |
79 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
80 | * but for now this should be fine. | |
81 | * | |
82 | * The reason for putting the locks in a separate array from the list heads | |
83 | * is that we can have fewer locks than list heads and save memory. We use | |
84 | * the same hash function for both, but with a different hash mask. | |
85 | */ | |
86 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
87 | defined(CONFIG_PROVE_LOCKING) | |
88 | ||
89 | #ifdef CONFIG_LOCKDEP | |
90 | # define GL_HASH_LOCK_SZ 256 | |
91 | #else | |
92 | # if NR_CPUS >= 32 | |
93 | # define GL_HASH_LOCK_SZ 4096 | |
94 | # elif NR_CPUS >= 16 | |
95 | # define GL_HASH_LOCK_SZ 2048 | |
96 | # elif NR_CPUS >= 8 | |
97 | # define GL_HASH_LOCK_SZ 1024 | |
98 | # elif NR_CPUS >= 4 | |
99 | # define GL_HASH_LOCK_SZ 512 | |
100 | # else | |
101 | # define GL_HASH_LOCK_SZ 256 | |
102 | # endif | |
103 | #endif | |
104 | ||
105 | /* We never want more locks than chains */ | |
106 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
107 | # undef GL_HASH_LOCK_SZ | |
108 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
109 | #endif | |
110 | ||
111 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
112 | ||
113 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
114 | { | |
94610610 | 115 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
116 | } |
117 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 118 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
119 | { |
120 | return NULL; | |
121 | } | |
122 | #endif | |
85d1da67 | 123 | |
b3b94faa DT |
124 | /** |
125 | * gl_hash() - Turn glock number into hash bucket number | |
126 | * @lock: The glock number | |
127 | * | |
128 | * Returns: The number of the corresponding hash bucket | |
129 | */ | |
130 | ||
b8547856 SW |
131 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
132 | const struct lm_lockname *name) | |
b3b94faa DT |
133 | { |
134 | unsigned int h; | |
135 | ||
cd915493 | 136 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 137 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 138 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
139 | h &= GFS2_GL_HASH_MASK; |
140 | ||
141 | return h; | |
142 | } | |
143 | ||
144 | /** | |
145 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
146 | * @gl: The glock to release | |
147 | * | |
148 | * Also calls lock module to release its internal structure for this glock. | |
149 | * | |
150 | */ | |
151 | ||
152 | static void glock_free(struct gfs2_glock *gl) | |
153 | { | |
154 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
155 | struct inode *aspace = gl->gl_aspace; | |
156 | ||
048bca22 | 157 | if (sdp->sd_lockstruct.ls_ops->lm_put_lock) |
da755fdb | 158 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gl->gl_lock); |
b3b94faa DT |
159 | |
160 | if (aspace) | |
161 | gfs2_aspace_put(aspace); | |
162 | ||
163 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
164 | } |
165 | ||
166 | /** | |
167 | * gfs2_glock_hold() - increment reference count on glock | |
168 | * @gl: The glock to hold | |
169 | * | |
170 | */ | |
171 | ||
048786f1 | 172 | static void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 173 | { |
16feb9fe | 174 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
175 | } |
176 | ||
177 | /** | |
178 | * gfs2_glock_put() - Decrement reference count on glock | |
179 | * @gl: The glock to put | |
180 | * | |
181 | */ | |
182 | ||
183 | int gfs2_glock_put(struct gfs2_glock *gl) | |
184 | { | |
b3b94faa DT |
185 | int rv = 0; |
186 | ||
087efdd3 | 187 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 188 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 189 | hlist_del(&gl->gl_list); |
087efdd3 | 190 | write_unlock(gl_lock_addr(gl->gl_hash)); |
6802e340 SW |
191 | GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_UNLOCKED); |
192 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_reclaim)); | |
193 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); | |
b3b94faa DT |
194 | glock_free(gl); |
195 | rv = 1; | |
196 | goto out; | |
197 | } | |
087efdd3 | 198 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 199 | out: |
b3b94faa DT |
200 | return rv; |
201 | } | |
202 | ||
b3b94faa DT |
203 | /** |
204 | * search_bucket() - Find struct gfs2_glock by lock number | |
205 | * @bucket: the bucket to search | |
206 | * @name: The lock name | |
207 | * | |
208 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
209 | */ | |
210 | ||
37b2fa6a | 211 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 212 | const struct gfs2_sbd *sdp, |
d6a53727 | 213 | const struct lm_lockname *name) |
b3b94faa DT |
214 | { |
215 | struct gfs2_glock *gl; | |
b6397893 | 216 | struct hlist_node *h; |
b3b94faa | 217 | |
b6397893 | 218 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
219 | if (!lm_name_equal(&gl->gl_name, name)) |
220 | continue; | |
899be4d3 SW |
221 | if (gl->gl_sbd != sdp) |
222 | continue; | |
b3b94faa | 223 | |
16feb9fe | 224 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
225 | |
226 | return gl; | |
227 | } | |
228 | ||
229 | return NULL; | |
230 | } | |
231 | ||
232 | /** | |
233 | * gfs2_glock_find() - Find glock by lock number | |
234 | * @sdp: The GFS2 superblock | |
235 | * @name: The lock name | |
236 | * | |
237 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
238 | */ | |
239 | ||
85d1da67 | 240 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 241 | const struct lm_lockname *name) |
b3b94faa | 242 | { |
37b2fa6a | 243 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
244 | struct gfs2_glock *gl; |
245 | ||
087efdd3 | 246 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 247 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 248 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
249 | |
250 | return gl; | |
251 | } | |
252 | ||
6802e340 SW |
253 | /** |
254 | * may_grant - check if its ok to grant a new lock | |
255 | * @gl: The glock | |
256 | * @gh: The lock request which we wish to grant | |
257 | * | |
258 | * Returns: true if its ok to grant the lock | |
259 | */ | |
260 | ||
261 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
262 | { | |
263 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
264 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
265 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
266 | return 0; | |
267 | if (gl->gl_state == gh->gh_state) | |
268 | return 1; | |
269 | if (gh->gh_flags & GL_EXACT) | |
270 | return 0; | |
209806ab SW |
271 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
272 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
273 | return 1; | |
274 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
275 | return 1; | |
276 | } | |
6802e340 SW |
277 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
278 | return 1; | |
279 | return 0; | |
280 | } | |
281 | ||
282 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
283 | { | |
284 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
285 | smp_mb__after_clear_bit(); | |
286 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
287 | } | |
288 | ||
289 | /** | |
290 | * do_promote - promote as many requests as possible on the current queue | |
291 | * @gl: The glock | |
292 | * | |
813e0c46 SW |
293 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
294 | * if a type specific operation is underway. | |
6802e340 SW |
295 | */ |
296 | ||
297 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
298 | __releases(&gl->gl_spin) |
299 | __acquires(&gl->gl_spin) | |
6802e340 SW |
300 | { |
301 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
302 | struct gfs2_holder *gh, *tmp; | |
303 | int ret; | |
304 | ||
305 | restart: | |
306 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
307 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
308 | continue; | |
309 | if (may_grant(gl, gh)) { | |
310 | if (gh->gh_list.prev == &gl->gl_holders && | |
311 | glops->go_lock) { | |
312 | spin_unlock(&gl->gl_spin); | |
313 | /* FIXME: eliminate this eventually */ | |
314 | ret = glops->go_lock(gh); | |
315 | spin_lock(&gl->gl_spin); | |
316 | if (ret) { | |
813e0c46 SW |
317 | if (ret == 1) |
318 | return 2; | |
6802e340 SW |
319 | gh->gh_error = ret; |
320 | list_del_init(&gh->gh_list); | |
321 | gfs2_holder_wake(gh); | |
322 | goto restart; | |
323 | } | |
324 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
325 | gfs2_holder_wake(gh); | |
326 | goto restart; | |
327 | } | |
328 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
329 | gfs2_holder_wake(gh); | |
330 | continue; | |
331 | } | |
332 | if (gh->gh_list.prev == &gl->gl_holders) | |
333 | return 1; | |
334 | break; | |
335 | } | |
336 | return 0; | |
337 | } | |
338 | ||
339 | /** | |
340 | * do_error - Something unexpected has happened during a lock request | |
341 | * | |
342 | */ | |
343 | ||
344 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
345 | { | |
346 | struct gfs2_holder *gh, *tmp; | |
347 | ||
348 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
349 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
350 | continue; | |
351 | if (ret & LM_OUT_ERROR) | |
352 | gh->gh_error = -EIO; | |
353 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
354 | gh->gh_error = GLR_TRYFAILED; | |
355 | else | |
356 | continue; | |
357 | list_del_init(&gh->gh_list); | |
358 | gfs2_holder_wake(gh); | |
359 | } | |
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 | if (held2) | |
394 | gfs2_glock_hold(gl); | |
395 | else | |
396 | gfs2_glock_put(gl); | |
397 | } | |
398 | ||
399 | gl->gl_state = new_state; | |
400 | gl->gl_tchange = jiffies; | |
401 | } | |
402 | ||
403 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
404 | { | |
405 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
406 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
407 | smp_mb__after_clear_bit(); | |
408 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
409 | } | |
410 | ||
411 | /** | |
412 | * finish_xmote - The DLM has replied to one of our lock requests | |
413 | * @gl: The glock | |
414 | * @ret: The status from the DLM | |
415 | * | |
416 | */ | |
417 | ||
418 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
419 | { | |
420 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
421 | struct gfs2_holder *gh; | |
422 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 423 | int rv; |
6802e340 SW |
424 | |
425 | spin_lock(&gl->gl_spin); | |
426 | state_change(gl, state); | |
427 | gh = find_first_waiter(gl); | |
428 | ||
429 | /* Demote to UN request arrived during demote to SH or DF */ | |
430 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
431 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
432 | gl->gl_target = LM_ST_UNLOCKED; | |
433 | ||
434 | /* Check for state != intended state */ | |
435 | if (unlikely(state != gl->gl_target)) { | |
436 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
437 | /* move to back of queue and try next entry */ | |
438 | if (ret & LM_OUT_CANCELED) { | |
439 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
440 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
441 | gh = find_first_waiter(gl); | |
442 | gl->gl_target = gh->gh_state; | |
443 | goto retry; | |
444 | } | |
445 | /* Some error or failed "try lock" - report it */ | |
446 | if ((ret & LM_OUT_ERROR) || | |
447 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
448 | gl->gl_target = gl->gl_state; | |
449 | do_error(gl, ret); | |
450 | goto out; | |
451 | } | |
452 | } | |
453 | switch(state) { | |
454 | /* Unlocked due to conversion deadlock, try again */ | |
455 | case LM_ST_UNLOCKED: | |
456 | retry: | |
457 | do_xmote(gl, gh, gl->gl_target); | |
458 | break; | |
459 | /* Conversion fails, unlock and try again */ | |
460 | case LM_ST_SHARED: | |
461 | case LM_ST_DEFERRED: | |
462 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
463 | break; | |
464 | default: /* Everything else */ | |
465 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
466 | GLOCK_BUG_ON(gl, 1); | |
467 | } | |
468 | spin_unlock(&gl->gl_spin); | |
469 | gfs2_glock_put(gl); | |
470 | return; | |
471 | } | |
472 | ||
473 | /* Fast path - we got what we asked for */ | |
474 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
475 | gfs2_demote_wake(gl); | |
476 | if (state != LM_ST_UNLOCKED) { | |
477 | if (glops->go_xmote_bh) { | |
6802e340 SW |
478 | spin_unlock(&gl->gl_spin); |
479 | rv = glops->go_xmote_bh(gl, gh); | |
480 | if (rv == -EAGAIN) | |
481 | return; | |
482 | spin_lock(&gl->gl_spin); | |
483 | if (rv) { | |
484 | do_error(gl, rv); | |
485 | goto out; | |
486 | } | |
487 | } | |
813e0c46 SW |
488 | rv = do_promote(gl); |
489 | if (rv == 2) | |
490 | goto out_locked; | |
6802e340 SW |
491 | } |
492 | out: | |
493 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 494 | out_locked: |
6802e340 SW |
495 | spin_unlock(&gl->gl_spin); |
496 | gfs2_glock_put(gl); | |
497 | } | |
498 | ||
499 | static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, | |
500 | unsigned int cur_state, unsigned int req_state, | |
501 | unsigned int flags) | |
502 | { | |
503 | int ret = LM_OUT_ERROR; | |
048bca22 SW |
504 | |
505 | if (!sdp->sd_lockstruct.ls_ops->lm_lock) | |
506 | return req_state == LM_ST_UNLOCKED ? 0 : req_state; | |
507 | ||
6802e340 SW |
508 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
509 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state, | |
510 | req_state, flags); | |
511 | return ret; | |
512 | } | |
513 | ||
514 | /** | |
515 | * do_xmote - Calls the DLM to change the state of a lock | |
516 | * @gl: The lock state | |
517 | * @gh: The holder (only for promotes) | |
518 | * @target: The target lock state | |
519 | * | |
520 | */ | |
521 | ||
522 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
523 | __releases(&gl->gl_spin) |
524 | __acquires(&gl->gl_spin) | |
6802e340 SW |
525 | { |
526 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
527 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
528 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
529 | int ret; | |
530 | ||
531 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
532 | LM_FLAG_PRIORITY); | |
533 | BUG_ON(gl->gl_state == target); | |
534 | BUG_ON(gl->gl_state == gl->gl_target); | |
535 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
536 | glops->go_inval) { | |
537 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
538 | do_error(gl, 0); /* Fail queued try locks */ | |
539 | } | |
540 | spin_unlock(&gl->gl_spin); | |
541 | if (glops->go_xmote_th) | |
542 | glops->go_xmote_th(gl); | |
543 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
544 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
545 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
546 | ||
547 | gfs2_glock_hold(gl); | |
548 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
549 | gl->gl_state == LM_ST_DEFERRED) && | |
550 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
551 | lck_flags |= LM_FLAG_TRY_1CB; | |
552 | ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, target, lck_flags); | |
553 | ||
554 | if (!(ret & LM_OUT_ASYNC)) { | |
555 | finish_xmote(gl, ret); | |
556 | gfs2_glock_hold(gl); | |
557 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
558 | gfs2_glock_put(gl); | |
559 | } else { | |
560 | GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); | |
561 | } | |
562 | spin_lock(&gl->gl_spin); | |
563 | } | |
564 | ||
565 | /** | |
566 | * find_first_holder - find the first "holder" gh | |
567 | * @gl: the glock | |
568 | */ | |
569 | ||
570 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
571 | { | |
572 | struct gfs2_holder *gh; | |
573 | ||
574 | if (!list_empty(&gl->gl_holders)) { | |
575 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
576 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
577 | return gh; | |
578 | } | |
579 | return NULL; | |
580 | } | |
581 | ||
582 | /** | |
583 | * run_queue - do all outstanding tasks related to a glock | |
584 | * @gl: The glock in question | |
585 | * @nonblock: True if we must not block in run_queue | |
586 | * | |
587 | */ | |
588 | ||
589 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
590 | __releases(&gl->gl_spin) |
591 | __acquires(&gl->gl_spin) | |
6802e340 SW |
592 | { |
593 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 594 | int ret; |
6802e340 SW |
595 | |
596 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
597 | return; | |
598 | ||
599 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
600 | ||
601 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
602 | gl->gl_demote_state != gl->gl_state) { | |
603 | if (find_first_holder(gl)) | |
604 | goto out; | |
605 | if (nonblock) | |
606 | goto out_sched; | |
607 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 608 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
609 | gl->gl_target = gl->gl_demote_state; |
610 | } else { | |
611 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
612 | gfs2_demote_wake(gl); | |
813e0c46 SW |
613 | ret = do_promote(gl); |
614 | if (ret == 0) | |
6802e340 | 615 | goto out; |
813e0c46 SW |
616 | if (ret == 2) |
617 | return; | |
6802e340 SW |
618 | gh = find_first_waiter(gl); |
619 | gl->gl_target = gh->gh_state; | |
620 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
621 | do_error(gl, 0); /* Fail queued try locks */ | |
622 | } | |
623 | do_xmote(gl, gh, gl->gl_target); | |
624 | return; | |
625 | ||
626 | out_sched: | |
627 | gfs2_glock_hold(gl); | |
628 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
629 | gfs2_glock_put(gl); | |
630 | out: | |
631 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
632 | } | |
633 | ||
c4f68a13 BM |
634 | static void glock_work_func(struct work_struct *work) |
635 | { | |
6802e340 | 636 | unsigned long delay = 0; |
c4f68a13 BM |
637 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
638 | ||
6802e340 SW |
639 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
640 | finish_xmote(gl, gl->gl_reply); | |
c4f68a13 | 641 | spin_lock(&gl->gl_spin); |
265d529c SW |
642 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
643 | gl->gl_state != LM_ST_UNLOCKED && | |
644 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
645 | unsigned long holdtime, now = jiffies; |
646 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
647 | if (time_before(now, holdtime)) | |
648 | delay = holdtime - now; | |
649 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
650 | } | |
651 | run_queue(gl, 0); | |
c4f68a13 | 652 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
653 | if (!delay || |
654 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
655 | gfs2_glock_put(gl); | |
c4f68a13 BM |
656 | } |
657 | ||
da755fdb SW |
658 | static int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name, |
659 | void **lockp) | |
660 | { | |
661 | int error = -EIO; | |
048bca22 SW |
662 | if (!sdp->sd_lockstruct.ls_ops->lm_get_lock) |
663 | return 0; | |
da755fdb SW |
664 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
665 | error = sdp->sd_lockstruct.ls_ops->lm_get_lock( | |
666 | sdp->sd_lockstruct.ls_lockspace, name, lockp); | |
667 | return error; | |
668 | } | |
669 | ||
b3b94faa DT |
670 | /** |
671 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
672 | * @sdp: The GFS2 superblock | |
673 | * @number: the lock number | |
674 | * @glops: The glock_operations to use | |
675 | * @create: If 0, don't create the glock if it doesn't exist | |
676 | * @glp: the glock is returned here | |
677 | * | |
678 | * This does not lock a glock, just finds/creates structures for one. | |
679 | * | |
680 | * Returns: errno | |
681 | */ | |
682 | ||
cd915493 | 683 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 684 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
685 | struct gfs2_glock **glp) |
686 | { | |
37b2fa6a | 687 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 688 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 689 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
690 | int error; |
691 | ||
087efdd3 | 692 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 693 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 694 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
695 | |
696 | if (gl || !create) { | |
697 | *glp = gl; | |
698 | return 0; | |
699 | } | |
700 | ||
701 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
702 | if (!gl) | |
703 | return -ENOMEM; | |
704 | ||
ec45d9f5 | 705 | gl->gl_flags = 0; |
b3b94faa | 706 | gl->gl_name = name; |
16feb9fe | 707 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 708 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 709 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 710 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 711 | gl->gl_hash = hash; |
b3b94faa | 712 | gl->gl_ops = glops; |
ec45d9f5 | 713 | gl->gl_stamp = jiffies; |
c4f68a13 | 714 | gl->gl_tchange = jiffies; |
ec45d9f5 | 715 | gl->gl_object = NULL; |
b3b94faa | 716 | gl->gl_sbd = sdp; |
ec45d9f5 | 717 | gl->gl_aspace = NULL; |
c4f68a13 | 718 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b3b94faa DT |
719 | |
720 | /* If this glock protects actual on-disk data or metadata blocks, | |
721 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 722 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
723 | gl->gl_aspace = gfs2_aspace_get(sdp); |
724 | if (!gl->gl_aspace) { | |
725 | error = -ENOMEM; | |
726 | goto fail; | |
727 | } | |
728 | } | |
729 | ||
730 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
731 | if (error) | |
732 | goto fail_aspace; | |
733 | ||
087efdd3 | 734 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 735 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 736 | if (tmp) { |
087efdd3 | 737 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
738 | glock_free(gl); |
739 | gl = tmp; | |
740 | } else { | |
b6397893 | 741 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 742 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
743 | } |
744 | ||
745 | *glp = gl; | |
746 | ||
747 | return 0; | |
748 | ||
ec45d9f5 | 749 | fail_aspace: |
b3b94faa DT |
750 | if (gl->gl_aspace) |
751 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 752 | fail: |
907b9bce | 753 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
754 | return error; |
755 | } | |
756 | ||
757 | /** | |
758 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
759 | * @gl: the glock | |
760 | * @state: the state we're requesting | |
761 | * @flags: the modifier flags | |
762 | * @gh: the holder structure | |
763 | * | |
764 | */ | |
765 | ||
190562bd | 766 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
767 | struct gfs2_holder *gh) |
768 | { | |
769 | INIT_LIST_HEAD(&gh->gh_list); | |
770 | gh->gh_gl = gl; | |
d0dc80db | 771 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 772 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
773 | gh->gh_state = state; |
774 | gh->gh_flags = flags; | |
775 | gh->gh_error = 0; | |
776 | gh->gh_iflags = 0; | |
b3b94faa DT |
777 | gfs2_glock_hold(gl); |
778 | } | |
779 | ||
780 | /** | |
781 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
782 | * @state: the state we're requesting | |
783 | * @flags: the modifier flags | |
784 | * @gh: the holder structure | |
785 | * | |
786 | * Don't mess with the glock. | |
787 | * | |
788 | */ | |
789 | ||
190562bd | 790 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
791 | { |
792 | gh->gh_state = state; | |
579b78a4 | 793 | gh->gh_flags = flags; |
3b8249f6 | 794 | gh->gh_iflags = 0; |
d0dc80db | 795 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
796 | } |
797 | ||
798 | /** | |
799 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
800 | * @gh: the holder structure | |
801 | * | |
802 | */ | |
803 | ||
804 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
805 | { | |
b1e058da | 806 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
807 | gfs2_glock_put(gh->gh_gl); |
808 | gh->gh_gl = NULL; | |
d0dc80db | 809 | gh->gh_ip = 0; |
b3b94faa DT |
810 | } |
811 | ||
d93cfa98 | 812 | static int just_schedule(void *word) |
fee852e3 SW |
813 | { |
814 | schedule(); | |
815 | return 0; | |
816 | } | |
817 | ||
6802e340 | 818 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 819 | { |
6802e340 SW |
820 | might_sleep(); |
821 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE); | |
da755fdb SW |
822 | } |
823 | ||
6802e340 | 824 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 825 | { |
6802e340 SW |
826 | might_sleep(); |
827 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE); | |
b3b94faa DT |
828 | } |
829 | ||
830 | /** | |
6802e340 SW |
831 | * handle_callback - process a demote request |
832 | * @gl: the glock | |
833 | * @state: the state the caller wants us to change to | |
b3b94faa | 834 | * |
6802e340 SW |
835 | * There are only two requests that we are going to see in actual |
836 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
837 | */ |
838 | ||
6802e340 SW |
839 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
840 | int remote, unsigned long delay) | |
b3b94faa | 841 | { |
6802e340 | 842 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 843 | |
6802e340 SW |
844 | set_bit(bit, &gl->gl_flags); |
845 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
846 | gl->gl_demote_state = state; | |
847 | gl->gl_demote_time = jiffies; | |
848 | if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN && | |
849 | gl->gl_object) | |
850 | gfs2_glock_schedule_for_reclaim(gl); | |
851 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && | |
852 | gl->gl_demote_state != state) { | |
853 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 854 | } |
b3b94faa DT |
855 | } |
856 | ||
857 | /** | |
6802e340 | 858 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
859 | * @gh: the glock holder |
860 | * | |
861 | * Returns: 0 on success | |
862 | */ | |
863 | ||
6802e340 | 864 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 865 | { |
fee852e3 | 866 | wait_on_holder(gh); |
b3b94faa DT |
867 | return gh->gh_error; |
868 | } | |
869 | ||
6802e340 | 870 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 RP |
871 | { |
872 | va_list args; | |
873 | ||
874 | va_start(args, fmt); | |
6802e340 SW |
875 | if (seq) { |
876 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 877 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
878 | seq_printf(seq, gi->string); |
879 | } else { | |
880 | printk(KERN_ERR " "); | |
7c52b166 | 881 | vprintk(fmt, args); |
6802e340 | 882 | } |
7c52b166 RP |
883 | va_end(args); |
884 | } | |
885 | ||
b3b94faa DT |
886 | /** |
887 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
888 | * @gh: the holder structure to add | |
889 | * | |
6802e340 SW |
890 | * Eventually we should move the recursive locking trap to a |
891 | * debugging option or something like that. This is the fast | |
892 | * path and needs to have the minimum number of distractions. | |
893 | * | |
b3b94faa DT |
894 | */ |
895 | ||
6802e340 | 896 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
897 | __releases(&gl->gl_spin) |
898 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
899 | { |
900 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
901 | struct gfs2_sbd *sdp = gl->gl_sbd; |
902 | struct list_head *insert_pt = NULL; | |
903 | struct gfs2_holder *gh2; | |
904 | int try_lock = 0; | |
b3b94faa | 905 | |
b1e058da | 906 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
907 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
908 | BUG(); | |
190562bd | 909 | |
6802e340 SW |
910 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
911 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
912 | try_lock = 1; | |
913 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
914 | goto fail; | |
915 | } | |
916 | ||
917 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
918 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
919 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
920 | goto trap_recursive; | |
921 | if (try_lock && | |
922 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
923 | !may_grant(gl, gh)) { | |
924 | fail: | |
925 | gh->gh_error = GLR_TRYFAILED; | |
926 | gfs2_holder_wake(gh); | |
927 | return; | |
b4c20166 | 928 | } |
6802e340 SW |
929 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
930 | continue; | |
931 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
932 | insert_pt = &gh2->gh_list; | |
933 | } | |
934 | if (likely(insert_pt == NULL)) { | |
935 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
936 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
937 | goto do_cancel; | |
938 | return; | |
939 | } | |
940 | list_add_tail(&gh->gh_list, insert_pt); | |
941 | do_cancel: | |
942 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
943 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
944 | spin_unlock(&gl->gl_spin); | |
048bca22 SW |
945 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
946 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock); | |
6802e340 | 947 | spin_lock(&gl->gl_spin); |
b3b94faa | 948 | } |
6802e340 | 949 | return; |
b3b94faa | 950 | |
6802e340 SW |
951 | trap_recursive: |
952 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
953 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
954 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
955 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
956 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
957 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
958 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
959 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
960 | __dump_glock(NULL, gl); | |
961 | BUG(); | |
b3b94faa DT |
962 | } |
963 | ||
964 | /** | |
965 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
966 | * @gh: the holder structure | |
967 | * | |
968 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
969 | * | |
970 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
971 | */ | |
972 | ||
973 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
974 | { | |
975 | struct gfs2_glock *gl = gh->gh_gl; | |
976 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
977 | int error = 0; | |
978 | ||
6802e340 | 979 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 980 | return -EIO; |
b3b94faa | 981 | |
b3b94faa DT |
982 | spin_lock(&gl->gl_spin); |
983 | add_to_queue(gh); | |
6802e340 | 984 | run_queue(gl, 1); |
b3b94faa DT |
985 | spin_unlock(&gl->gl_spin); |
986 | ||
6802e340 SW |
987 | if (!(gh->gh_flags & GL_ASYNC)) |
988 | error = gfs2_glock_wait(gh); | |
b3b94faa | 989 | |
b3b94faa DT |
990 | return error; |
991 | } | |
992 | ||
993 | /** | |
994 | * gfs2_glock_poll - poll to see if an async request has been completed | |
995 | * @gh: the holder | |
996 | * | |
997 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
998 | */ | |
999 | ||
1000 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1001 | { | |
6802e340 | 1002 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1003 | } |
1004 | ||
1005 | /** | |
1006 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1007 | * @gh: the glock holder | |
1008 | * | |
1009 | */ | |
1010 | ||
1011 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1012 | { | |
1013 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1014 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1015 | unsigned delay = 0; |
6802e340 | 1016 | int fast_path = 0; |
b3b94faa | 1017 | |
6802e340 | 1018 | spin_lock(&gl->gl_spin); |
b3b94faa | 1019 | if (gh->gh_flags & GL_NOCACHE) |
c4f68a13 | 1020 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa | 1021 | |
b3b94faa | 1022 | list_del_init(&gh->gh_list); |
6802e340 | 1023 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1024 | if (glops->go_unlock) { |
6802e340 | 1025 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1026 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1027 | glops->go_unlock(gh); |
3042a2cc | 1028 | spin_lock(&gl->gl_spin); |
6802e340 | 1029 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1030 | } |
3b8249f6 | 1031 | gl->gl_stamp = jiffies; |
6802e340 SW |
1032 | if (list_empty(&gl->gl_holders) && |
1033 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1034 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1035 | fast_path = 1; | |
b3b94faa | 1036 | } |
b3b94faa | 1037 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1038 | if (likely(fast_path)) |
1039 | return; | |
c4f68a13 BM |
1040 | |
1041 | gfs2_glock_hold(gl); | |
1042 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1043 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1044 | delay = gl->gl_ops->go_min_hold_time; | |
1045 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1046 | gfs2_glock_put(gl); | |
b3b94faa DT |
1047 | } |
1048 | ||
d93cfa98 AD |
1049 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1050 | { | |
1051 | struct gfs2_glock *gl = gh->gh_gl; | |
1052 | gfs2_glock_dq(gh); | |
1053 | wait_on_demote(gl); | |
1054 | } | |
1055 | ||
b3b94faa DT |
1056 | /** |
1057 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1058 | * @gh: the holder structure | |
1059 | * | |
1060 | */ | |
1061 | ||
1062 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1063 | { | |
1064 | gfs2_glock_dq(gh); | |
1065 | gfs2_holder_uninit(gh); | |
1066 | } | |
1067 | ||
1068 | /** | |
1069 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1070 | * @sdp: the filesystem | |
1071 | * @number: the lock number | |
1072 | * @glops: the glock operations for the type of glock | |
1073 | * @state: the state to acquire the glock in | |
1074 | * @flags: modifier flags for the aquisition | |
1075 | * @gh: the struct gfs2_holder | |
1076 | * | |
1077 | * Returns: errno | |
1078 | */ | |
1079 | ||
cd915493 | 1080 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1081 | const struct gfs2_glock_operations *glops, |
1082 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1083 | { |
1084 | struct gfs2_glock *gl; | |
1085 | int error; | |
1086 | ||
1087 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1088 | if (!error) { | |
1089 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1090 | gfs2_glock_put(gl); | |
1091 | } | |
1092 | ||
1093 | return error; | |
1094 | } | |
1095 | ||
1096 | /** | |
1097 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1098 | * @arg_a: the first structure | |
1099 | * @arg_b: the second structure | |
1100 | * | |
1101 | */ | |
1102 | ||
1103 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1104 | { | |
a5e08a9e SW |
1105 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1106 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1107 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1108 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1109 | |
1110 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1111 | return 1; |
1112 | if (a->ln_number < b->ln_number) | |
1113 | return -1; | |
1c0f4872 | 1114 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1115 | return 0; |
b3b94faa DT |
1116 | } |
1117 | ||
1118 | /** | |
1119 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1120 | * @num_gh: the number of structures | |
1121 | * @ghs: an array of struct gfs2_holder structures | |
1122 | * | |
1123 | * Returns: 0 on success (all glocks acquired), | |
1124 | * errno on failure (no glocks acquired) | |
1125 | */ | |
1126 | ||
1127 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1128 | struct gfs2_holder **p) | |
1129 | { | |
1130 | unsigned int x; | |
1131 | int error = 0; | |
1132 | ||
1133 | for (x = 0; x < num_gh; x++) | |
1134 | p[x] = &ghs[x]; | |
1135 | ||
1136 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1137 | ||
1138 | for (x = 0; x < num_gh; x++) { | |
1139 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1140 | ||
1141 | error = gfs2_glock_nq(p[x]); | |
1142 | if (error) { | |
1143 | while (x--) | |
1144 | gfs2_glock_dq(p[x]); | |
1145 | break; | |
1146 | } | |
1147 | } | |
1148 | ||
1149 | return error; | |
1150 | } | |
1151 | ||
1152 | /** | |
1153 | * gfs2_glock_nq_m - acquire multiple glocks | |
1154 | * @num_gh: the number of structures | |
1155 | * @ghs: an array of struct gfs2_holder structures | |
1156 | * | |
b3b94faa DT |
1157 | * |
1158 | * Returns: 0 on success (all glocks acquired), | |
1159 | * errno on failure (no glocks acquired) | |
1160 | */ | |
1161 | ||
1162 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1163 | { | |
eaf5bd3c SW |
1164 | struct gfs2_holder *tmp[4]; |
1165 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1166 | int error = 0; |
1167 | ||
eaf5bd3c SW |
1168 | switch(num_gh) { |
1169 | case 0: | |
b3b94faa | 1170 | return 0; |
eaf5bd3c | 1171 | case 1: |
b3b94faa DT |
1172 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1173 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1174 | default: |
1175 | if (num_gh <= 4) | |
b3b94faa | 1176 | break; |
eaf5bd3c SW |
1177 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1178 | if (!pph) | |
1179 | return -ENOMEM; | |
b3b94faa DT |
1180 | } |
1181 | ||
eaf5bd3c | 1182 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1183 | |
eaf5bd3c SW |
1184 | if (pph != tmp) |
1185 | kfree(pph); | |
b3b94faa DT |
1186 | |
1187 | return error; | |
1188 | } | |
1189 | ||
1190 | /** | |
1191 | * gfs2_glock_dq_m - release multiple glocks | |
1192 | * @num_gh: the number of structures | |
1193 | * @ghs: an array of struct gfs2_holder structures | |
1194 | * | |
1195 | */ | |
1196 | ||
1197 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1198 | { | |
1199 | unsigned int x; | |
1200 | ||
1201 | for (x = 0; x < num_gh; x++) | |
1202 | gfs2_glock_dq(&ghs[x]); | |
1203 | } | |
1204 | ||
1205 | /** | |
1206 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1207 | * @num_gh: the number of structures | |
1208 | * @ghs: an array of struct gfs2_holder structures | |
1209 | * | |
1210 | */ | |
1211 | ||
1212 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1213 | { | |
1214 | unsigned int x; | |
1215 | ||
1216 | for (x = 0; x < num_gh; x++) | |
1217 | gfs2_glock_dq_uninit(&ghs[x]); | |
1218 | } | |
1219 | ||
da755fdb SW |
1220 | static int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, void *lock, char **lvbp) |
1221 | { | |
1222 | int error = -EIO; | |
048bca22 SW |
1223 | if (!sdp->sd_lockstruct.ls_ops->lm_hold_lvb) |
1224 | return 0; | |
da755fdb SW |
1225 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
1226 | error = sdp->sd_lockstruct.ls_ops->lm_hold_lvb(lock, lvbp); | |
1227 | return error; | |
1228 | } | |
1229 | ||
b3b94faa DT |
1230 | /** |
1231 | * gfs2_lvb_hold - attach a LVB from a glock | |
1232 | * @gl: The glock in question | |
1233 | * | |
1234 | */ | |
1235 | ||
1236 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1237 | { | |
1238 | int error; | |
1239 | ||
b3b94faa DT |
1240 | if (!atomic_read(&gl->gl_lvb_count)) { |
1241 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
6802e340 | 1242 | if (error) |
b3b94faa | 1243 | return error; |
b3b94faa DT |
1244 | gfs2_glock_hold(gl); |
1245 | } | |
1246 | atomic_inc(&gl->gl_lvb_count); | |
1247 | ||
b3b94faa DT |
1248 | return 0; |
1249 | } | |
1250 | ||
1251 | /** | |
1252 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1253 | * @gl: The glock in question | |
1254 | * | |
1255 | */ | |
1256 | ||
1257 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1258 | { | |
da755fdb SW |
1259 | struct gfs2_sbd *sdp = gl->gl_sbd; |
1260 | ||
b3b94faa | 1261 | gfs2_glock_hold(gl); |
b3b94faa DT |
1262 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); |
1263 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
048bca22 | 1264 | if (sdp->sd_lockstruct.ls_ops->lm_unhold_lvb) |
da755fdb | 1265 | sdp->sd_lockstruct.ls_ops->lm_unhold_lvb(gl->gl_lock, gl->gl_lvb); |
b3b94faa DT |
1266 | gl->gl_lvb = NULL; |
1267 | gfs2_glock_put(gl); | |
1268 | } | |
b3b94faa DT |
1269 | gfs2_glock_put(gl); |
1270 | } | |
1271 | ||
b3b94faa DT |
1272 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1273 | unsigned int state) | |
1274 | { | |
1275 | struct gfs2_glock *gl; | |
c4f68a13 BM |
1276 | unsigned long delay = 0; |
1277 | unsigned long holdtime; | |
1278 | unsigned long now = jiffies; | |
b3b94faa DT |
1279 | |
1280 | gl = gfs2_glock_find(sdp, name); | |
1281 | if (!gl) | |
1282 | return; | |
1283 | ||
c4f68a13 BM |
1284 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1285 | if (time_before(now, holdtime)) | |
1286 | delay = holdtime - now; | |
dff52574 SW |
1287 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
1288 | delay = gl->gl_ops->go_min_hold_time; | |
b3b94faa | 1289 | |
6802e340 | 1290 | spin_lock(&gl->gl_spin); |
c4f68a13 | 1291 | handle_callback(gl, state, 1, delay); |
6802e340 | 1292 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1293 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1294 | gfs2_glock_put(gl); | |
b3b94faa DT |
1295 | } |
1296 | ||
1297 | /** | |
1298 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1299 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1300 | * @type: Type of callback |
1301 | * @data: Type dependent data pointer | |
1302 | * | |
1303 | * Called by the locking module when it wants to tell us something. | |
1304 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1305 | * a journal from another client needs to be recovered. | |
1306 | */ | |
1307 | ||
9b47c11d | 1308 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1309 | { |
9b47c11d | 1310 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1311 | |
b3b94faa DT |
1312 | switch (type) { |
1313 | case LM_CB_NEED_E: | |
e7f5c01c | 1314 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1315 | return; |
1316 | ||
1317 | case LM_CB_NEED_D: | |
e7f5c01c | 1318 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1319 | return; |
1320 | ||
1321 | case LM_CB_NEED_S: | |
e7f5c01c | 1322 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1323 | return; |
1324 | ||
1325 | case LM_CB_ASYNC: { | |
e7f5c01c | 1326 | struct lm_async_cb *async = data; |
b3b94faa DT |
1327 | struct gfs2_glock *gl; |
1328 | ||
61be084e | 1329 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1330 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1331 | if (gfs2_assert_warn(sdp, gl)) | |
1332 | return; | |
6802e340 SW |
1333 | gl->gl_reply = async->lc_ret; |
1334 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); | |
c4f68a13 BM |
1335 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
1336 | gfs2_glock_put(gl); | |
61be084e | 1337 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1338 | return; |
1339 | } | |
1340 | ||
1341 | case LM_CB_NEED_RECOVERY: | |
1342 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1343 | if (sdp->sd_recoverd_process) | |
1344 | wake_up_process(sdp->sd_recoverd_process); | |
1345 | return; | |
1346 | ||
b3b94faa DT |
1347 | default: |
1348 | gfs2_assert_warn(sdp, 0); | |
1349 | return; | |
1350 | } | |
1351 | } | |
1352 | ||
b3b94faa DT |
1353 | /** |
1354 | * demote_ok - Check to see if it's ok to unlock a glock | |
1355 | * @gl: the glock | |
1356 | * | |
1357 | * Returns: 1 if it's ok | |
1358 | */ | |
1359 | ||
1360 | static int demote_ok(struct gfs2_glock *gl) | |
1361 | { | |
8fb4b536 | 1362 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1363 | int demote = 1; |
1364 | ||
1365 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1366 | demote = 0; | |
b3b94faa DT |
1367 | else if (glops->go_demote_ok) |
1368 | demote = glops->go_demote_ok(gl); | |
1369 | ||
1370 | return demote; | |
1371 | } | |
1372 | ||
1373 | /** | |
1374 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1375 | * @gl: the glock | |
1376 | * | |
1377 | */ | |
1378 | ||
1379 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1380 | { | |
1381 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1382 | ||
1383 | spin_lock(&sdp->sd_reclaim_lock); | |
1384 | if (list_empty(&gl->gl_reclaim)) { | |
1385 | gfs2_glock_hold(gl); | |
1386 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1387 | atomic_inc(&sdp->sd_reclaim_count); | |
ef8c441c BP |
1388 | spin_unlock(&sdp->sd_reclaim_lock); |
1389 | wake_up(&sdp->sd_reclaim_wq); | |
1390 | } else | |
1391 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa DT |
1392 | } |
1393 | ||
1394 | /** | |
1395 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1396 | * @sdp: the filesystem | |
1397 | * | |
1398 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1399 | * different glock and we notice that there are a lot of glocks in the | |
1400 | * reclaim list. | |
1401 | * | |
1402 | */ | |
1403 | ||
1404 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1405 | { | |
1406 | struct gfs2_glock *gl; | |
6802e340 | 1407 | int done_callback = 0; |
b3b94faa DT |
1408 | |
1409 | spin_lock(&sdp->sd_reclaim_lock); | |
1410 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1411 | spin_unlock(&sdp->sd_reclaim_lock); | |
1412 | return; | |
1413 | } | |
1414 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1415 | struct gfs2_glock, gl_reclaim); | |
1416 | list_del_init(&gl->gl_reclaim); | |
1417 | spin_unlock(&sdp->sd_reclaim_lock); | |
1418 | ||
1419 | atomic_dec(&sdp->sd_reclaim_count); | |
1420 | atomic_inc(&sdp->sd_reclaimed); | |
1421 | ||
6802e340 SW |
1422 | spin_lock(&gl->gl_spin); |
1423 | if (find_first_holder(gl) == NULL && | |
1424 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) { | |
1425 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); | |
1426 | done_callback = 1; | |
b3b94faa | 1427 | } |
6802e340 SW |
1428 | spin_unlock(&gl->gl_spin); |
1429 | if (!done_callback || | |
1430 | queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1431 | gfs2_glock_put(gl); | |
b3b94faa DT |
1432 | } |
1433 | ||
1434 | /** | |
1435 | * examine_bucket - Call a function for glock in a hash bucket | |
1436 | * @examiner: the function | |
1437 | * @sdp: the filesystem | |
1438 | * @bucket: the bucket | |
1439 | * | |
1440 | * Returns: 1 if the bucket has entries | |
1441 | */ | |
1442 | ||
1443 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1444 | unsigned int hash) |
b3b94faa | 1445 | { |
24264434 SW |
1446 | struct gfs2_glock *gl, *prev = NULL; |
1447 | int has_entries = 0; | |
b6397893 | 1448 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1449 | |
24264434 | 1450 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1451 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1452 | if (hlist_empty(head)) | |
24264434 | 1453 | goto out; |
b6397893 SW |
1454 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1455 | while(1) { | |
8fbbfd21 | 1456 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1457 | gfs2_glock_hold(gl); |
24264434 SW |
1458 | read_unlock(gl_lock_addr(hash)); |
1459 | if (prev) | |
1460 | gfs2_glock_put(prev); | |
1461 | prev = gl; | |
1462 | examiner(gl); | |
a8336344 | 1463 | has_entries = 1; |
24264434 | 1464 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1465 | } |
b6397893 SW |
1466 | if (gl->gl_list.next == NULL) |
1467 | break; | |
24264434 | 1468 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1469 | } |
24264434 SW |
1470 | out: |
1471 | read_unlock(gl_lock_addr(hash)); | |
1472 | if (prev) | |
1473 | gfs2_glock_put(prev); | |
8fbbfd21 | 1474 | cond_resched(); |
24264434 | 1475 | return has_entries; |
b3b94faa DT |
1476 | } |
1477 | ||
1478 | /** | |
1479 | * scan_glock - look at a glock and see if we can reclaim it | |
1480 | * @gl: the glock to look at | |
1481 | * | |
1482 | */ | |
1483 | ||
1484 | static void scan_glock(struct gfs2_glock *gl) | |
1485 | { | |
b004157a | 1486 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1487 | return; |
6802e340 SW |
1488 | if (test_bit(GLF_LOCK, &gl->gl_flags)) |
1489 | return; | |
a2242db0 | 1490 | |
6802e340 SW |
1491 | spin_lock(&gl->gl_spin); |
1492 | if (find_first_holder(gl) == NULL && | |
1493 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) | |
1494 | gfs2_glock_schedule_for_reclaim(gl); | |
1495 | spin_unlock(&gl->gl_spin); | |
b3b94faa DT |
1496 | } |
1497 | ||
b3b94faa DT |
1498 | /** |
1499 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1500 | * @gl: the glock to look at | |
1501 | * | |
1502 | */ | |
1503 | ||
1504 | static void clear_glock(struct gfs2_glock *gl) | |
1505 | { | |
1506 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1507 | int released; | |
1508 | ||
1509 | spin_lock(&sdp->sd_reclaim_lock); | |
1510 | if (!list_empty(&gl->gl_reclaim)) { | |
1511 | list_del_init(&gl->gl_reclaim); | |
1512 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1513 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1514 | released = gfs2_glock_put(gl); |
1515 | gfs2_assert(sdp, !released); | |
190562bd SW |
1516 | } else { |
1517 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1518 | } |
b3b94faa | 1519 | |
6802e340 SW |
1520 | spin_lock(&gl->gl_spin); |
1521 | if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED) | |
1522 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); | |
1523 | spin_unlock(&gl->gl_spin); | |
1524 | gfs2_glock_hold(gl); | |
1525 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1526 | gfs2_glock_put(gl); | |
b3b94faa DT |
1527 | } |
1528 | ||
1529 | /** | |
1530 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1531 | * @sdp: the filesystem | |
1532 | * @wait: wait until it's all gone | |
1533 | * | |
1bdad606 | 1534 | * Called when unmounting the filesystem. |
b3b94faa DT |
1535 | */ |
1536 | ||
1bdad606 | 1537 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa DT |
1538 | { |
1539 | unsigned long t; | |
1540 | unsigned int x; | |
1541 | int cont; | |
1542 | ||
1543 | t = jiffies; | |
1544 | ||
1545 | for (;;) { | |
1546 | cont = 0; | |
24264434 | 1547 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1548 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1549 | cont = 1; |
24264434 | 1550 | } |
b3b94faa | 1551 | |
1bdad606 | 1552 | if (!cont) |
b3b94faa DT |
1553 | break; |
1554 | ||
1555 | if (time_after_eq(jiffies, | |
1556 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1557 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1558 | "Dumping lock state...\n"); | |
1559 | gfs2_dump_lockstate(sdp); | |
1560 | t = jiffies; | |
1561 | } | |
1562 | ||
61be084e | 1563 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1564 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1565 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1566 | msleep(10); |
b3b94faa DT |
1567 | } |
1568 | } | |
1569 | ||
813e0c46 SW |
1570 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1571 | { | |
1572 | struct gfs2_glock *gl = ip->i_gl; | |
1573 | int ret; | |
1574 | ||
1575 | ret = gfs2_truncatei_resume(ip); | |
1576 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1577 | ||
1578 | spin_lock(&gl->gl_spin); | |
1579 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1580 | run_queue(gl, 1); | |
1581 | spin_unlock(&gl->gl_spin); | |
1582 | } | |
1583 | ||
6802e340 | 1584 | static const char *state2str(unsigned state) |
04b933f2 | 1585 | { |
6802e340 SW |
1586 | switch(state) { |
1587 | case LM_ST_UNLOCKED: | |
1588 | return "UN"; | |
1589 | case LM_ST_SHARED: | |
1590 | return "SH"; | |
1591 | case LM_ST_DEFERRED: | |
1592 | return "DF"; | |
1593 | case LM_ST_EXCLUSIVE: | |
1594 | return "EX"; | |
1595 | } | |
1596 | return "??"; | |
1597 | } | |
1598 | ||
1599 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1600 | { | |
1601 | char *p = buf; | |
1602 | if (flags & LM_FLAG_TRY) | |
1603 | *p++ = 't'; | |
1604 | if (flags & LM_FLAG_TRY_1CB) | |
1605 | *p++ = 'T'; | |
1606 | if (flags & LM_FLAG_NOEXP) | |
1607 | *p++ = 'e'; | |
1608 | if (flags & LM_FLAG_ANY) | |
1609 | *p++ = 'a'; | |
1610 | if (flags & LM_FLAG_PRIORITY) | |
1611 | *p++ = 'p'; | |
1612 | if (flags & GL_ASYNC) | |
1613 | *p++ = 'a'; | |
1614 | if (flags & GL_EXACT) | |
1615 | *p++ = 'E'; | |
6802e340 SW |
1616 | if (flags & GL_NOCACHE) |
1617 | *p++ = 'c'; | |
1618 | if (test_bit(HIF_HOLDER, &iflags)) | |
1619 | *p++ = 'H'; | |
1620 | if (test_bit(HIF_WAIT, &iflags)) | |
1621 | *p++ = 'W'; | |
1622 | if (test_bit(HIF_FIRST, &iflags)) | |
1623 | *p++ = 'F'; | |
1624 | *p = 0; | |
1625 | return buf; | |
04b933f2 RP |
1626 | } |
1627 | ||
b3b94faa DT |
1628 | /** |
1629 | * dump_holder - print information about a glock holder | |
6802e340 | 1630 | * @seq: the seq_file struct |
b3b94faa DT |
1631 | * @gh: the glock holder |
1632 | * | |
1633 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1634 | */ | |
1635 | ||
6802e340 | 1636 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1637 | { |
6802e340 SW |
1638 | struct task_struct *gh_owner = NULL; |
1639 | char buffer[KSYM_SYMBOL_LEN]; | |
1640 | char flags_buf[32]; | |
b3b94faa | 1641 | |
6802e340 SW |
1642 | sprint_symbol(buffer, gh->gh_ip); |
1643 | if (gh->gh_owner_pid) | |
b1e058da | 1644 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
6802e340 SW |
1645 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", |
1646 | state2str(gh->gh_state), | |
1647 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1648 | gh->gh_error, | |
1649 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1650 | gh_owner ? gh_owner->comm : "(ended)", buffer); | |
7c52b166 | 1651 | return 0; |
b3b94faa DT |
1652 | } |
1653 | ||
6802e340 SW |
1654 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1655 | { | |
1656 | char *p = buf; | |
1657 | if (test_bit(GLF_LOCK, gflags)) | |
1658 | *p++ = 'l'; | |
1659 | if (test_bit(GLF_STICKY, gflags)) | |
1660 | *p++ = 's'; | |
1661 | if (test_bit(GLF_DEMOTE, gflags)) | |
1662 | *p++ = 'D'; | |
1663 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1664 | *p++ = 'd'; | |
1665 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1666 | *p++ = 'p'; | |
1667 | if (test_bit(GLF_DIRTY, gflags)) | |
1668 | *p++ = 'y'; | |
1669 | if (test_bit(GLF_LFLUSH, gflags)) | |
1670 | *p++ = 'f'; | |
1671 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1672 | *p++ = 'i'; | |
1673 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1674 | *p++ = 'r'; | |
1675 | *p = 0; | |
1676 | return buf; | |
b3b94faa DT |
1677 | } |
1678 | ||
1679 | /** | |
6802e340 SW |
1680 | * __dump_glock - print information about a glock |
1681 | * @seq: The seq_file struct | |
b3b94faa | 1682 | * @gl: the glock |
6802e340 SW |
1683 | * |
1684 | * The file format is as follows: | |
1685 | * One line per object, capital letters are used to indicate objects | |
1686 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1687 | * other objects are indented by a single space and follow the glock to | |
1688 | * which they are related. Fields are indicated by lower case letters | |
1689 | * followed by a colon and the field value, except for strings which are in | |
1690 | * [] so that its possible to see if they are composed of spaces for | |
1691 | * example. The field's are n = number (id of the object), f = flags, | |
1692 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1693 | * |
1694 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1695 | */ | |
1696 | ||
6802e340 | 1697 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1698 | { |
6802e340 SW |
1699 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1700 | unsigned long long dtime; | |
1701 | const struct gfs2_holder *gh; | |
1702 | char gflags_buf[32]; | |
1703 | int error = 0; | |
b3b94faa | 1704 | |
6802e340 SW |
1705 | dtime = jiffies - gl->gl_demote_time; |
1706 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1707 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1708 | dtime = 0; | |
1709 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu l:%d a:%d r:%d\n", | |
1710 | state2str(gl->gl_state), | |
1711 | gl->gl_name.ln_type, | |
1712 | (unsigned long long)gl->gl_name.ln_number, | |
1713 | gflags2str(gflags_buf, &gl->gl_flags), | |
1714 | state2str(gl->gl_target), | |
1715 | state2str(gl->gl_demote_state), dtime, | |
1716 | atomic_read(&gl->gl_lvb_count), | |
1717 | atomic_read(&gl->gl_ail_count), | |
1718 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1719 | |
b3b94faa | 1720 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1721 | error = dump_holder(seq, gh); |
b3b94faa DT |
1722 | if (error) |
1723 | goto out; | |
1724 | } | |
6802e340 SW |
1725 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1726 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1727 | out: |
b3b94faa DT |
1728 | return error; |
1729 | } | |
1730 | ||
6802e340 SW |
1731 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1732 | { | |
1733 | int ret; | |
1734 | spin_lock(&gl->gl_spin); | |
1735 | ret = __dump_glock(seq, gl); | |
1736 | spin_unlock(&gl->gl_spin); | |
1737 | return ret; | |
1738 | } | |
1739 | ||
b3b94faa DT |
1740 | /** |
1741 | * gfs2_dump_lockstate - print out the current lockstate | |
1742 | * @sdp: the filesystem | |
1743 | * @ub: the buffer to copy the information into | |
1744 | * | |
1745 | * If @ub is NULL, dump the lockstate to the console. | |
1746 | * | |
1747 | */ | |
1748 | ||
08bc2dbc | 1749 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1750 | { |
b3b94faa | 1751 | struct gfs2_glock *gl; |
b6397893 | 1752 | struct hlist_node *h; |
b3b94faa DT |
1753 | unsigned int x; |
1754 | int error = 0; | |
1755 | ||
1756 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1757 | |
087efdd3 | 1758 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1759 | |
b6397893 | 1760 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1761 | if (gl->gl_sbd != sdp) |
1762 | continue; | |
b3b94faa | 1763 | |
7c52b166 | 1764 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1765 | if (error) |
1766 | break; | |
1767 | } | |
1768 | ||
087efdd3 | 1769 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1770 | |
1771 | if (error) | |
1772 | break; | |
1773 | } | |
1774 | ||
1775 | ||
1776 | return error; | |
1777 | } | |
1778 | ||
8fbbfd21 SW |
1779 | /** |
1780 | * gfs2_scand - Look for cached glocks and inodes to toss from memory | |
1781 | * @sdp: Pointer to GFS2 superblock | |
1782 | * | |
1783 | * One of these daemons runs, finding candidates to add to sd_reclaim_list. | |
1784 | * See gfs2_glockd() | |
1785 | */ | |
1786 | ||
1787 | static int gfs2_scand(void *data) | |
1788 | { | |
1789 | unsigned x; | |
1790 | unsigned delay; | |
1791 | ||
1792 | while (!kthread_should_stop()) { | |
1793 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1794 | examine_bucket(scan_glock, NULL, x); | |
1795 | if (freezing(current)) | |
1796 | refrigerator(); | |
1797 | delay = scand_secs; | |
1798 | if (delay < 1) | |
1799 | delay = 1; | |
1800 | schedule_timeout_interruptible(delay * HZ); | |
1801 | } | |
1802 | ||
1803 | return 0; | |
1804 | } | |
1805 | ||
1806 | ||
1807 | ||
85d1da67 SW |
1808 | int __init gfs2_glock_init(void) |
1809 | { | |
1810 | unsigned i; | |
1811 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1812 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1813 | } |
087efdd3 SW |
1814 | #ifdef GL_HASH_LOCK_SZ |
1815 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1816 | rwlock_init(&gl_hash_locks[i]); | |
1817 | } | |
1818 | #endif | |
8fbbfd21 SW |
1819 | |
1820 | scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand"); | |
1821 | if (IS_ERR(scand_process)) | |
1822 | return PTR_ERR(scand_process); | |
1823 | ||
c4f68a13 BM |
1824 | glock_workqueue = create_workqueue("glock_workqueue"); |
1825 | if (IS_ERR(glock_workqueue)) { | |
1826 | kthread_stop(scand_process); | |
1827 | return PTR_ERR(glock_workqueue); | |
1828 | } | |
1829 | ||
85d1da67 SW |
1830 | return 0; |
1831 | } | |
1832 | ||
8fbbfd21 SW |
1833 | void gfs2_glock_exit(void) |
1834 | { | |
c4f68a13 | 1835 | destroy_workqueue(glock_workqueue); |
8fbbfd21 SW |
1836 | kthread_stop(scand_process); |
1837 | } | |
1838 | ||
1839 | module_param(scand_secs, uint, S_IRUGO|S_IWUSR); | |
1840 | MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs"); | |
1841 | ||
6802e340 | 1842 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1843 | { |
7b08fc62 SW |
1844 | struct gfs2_glock *gl; |
1845 | ||
a947e033 | 1846 | restart: |
7a0079d9 | 1847 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1848 | gl = gi->gl; |
1849 | if (gl) { | |
a947e033 AD |
1850 | gi->gl = hlist_entry(gl->gl_list.next, |
1851 | struct gfs2_glock, gl_list); | |
c1e817d0 SW |
1852 | } else { |
1853 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1854 | struct gfs2_glock, gl_list); | |
7c52b166 | 1855 | } |
c1e817d0 SW |
1856 | if (gi->gl) |
1857 | gfs2_glock_hold(gi->gl); | |
7a0079d9 | 1858 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1859 | if (gl) |
1860 | gfs2_glock_put(gl); | |
6802e340 | 1861 | while (gi->gl == NULL) { |
c1e817d0 | 1862 | gi->hash++; |
7b08fc62 SW |
1863 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
1864 | return 1; | |
1865 | read_lock(gl_lock_addr(gi->hash)); | |
1866 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1867 | struct gfs2_glock, gl_list); | |
1868 | if (gi->gl) | |
1869 | gfs2_glock_hold(gi->gl); | |
1870 | read_unlock(gl_lock_addr(gi->hash)); | |
1871 | } | |
a947e033 AD |
1872 | |
1873 | if (gi->sdp != gi->gl->gl_sbd) | |
1874 | goto restart; | |
1875 | ||
7c52b166 RP |
1876 | return 0; |
1877 | } | |
1878 | ||
6802e340 | 1879 | static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) |
7c52b166 | 1880 | { |
7b08fc62 SW |
1881 | if (gi->gl) |
1882 | gfs2_glock_put(gi->gl); | |
a947e033 | 1883 | gi->gl = NULL; |
7c52b166 RP |
1884 | } |
1885 | ||
6802e340 | 1886 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1887 | { |
6802e340 | 1888 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1889 | loff_t n = *pos; |
1890 | ||
6802e340 | 1891 | gi->hash = 0; |
7c52b166 | 1892 | |
6802e340 | 1893 | do { |
7c52b166 RP |
1894 | if (gfs2_glock_iter_next(gi)) { |
1895 | gfs2_glock_iter_free(gi); | |
1896 | return NULL; | |
1897 | } | |
6802e340 | 1898 | } while (n--); |
7c52b166 | 1899 | |
6802e340 | 1900 | return gi->gl; |
7c52b166 RP |
1901 | } |
1902 | ||
6802e340 | 1903 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1904 | loff_t *pos) |
1905 | { | |
6802e340 | 1906 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1907 | |
1908 | (*pos)++; | |
1909 | ||
1910 | if (gfs2_glock_iter_next(gi)) { | |
1911 | gfs2_glock_iter_free(gi); | |
1912 | return NULL; | |
1913 | } | |
1914 | ||
6802e340 | 1915 | return gi->gl; |
7c52b166 RP |
1916 | } |
1917 | ||
6802e340 | 1918 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1919 | { |
6802e340 SW |
1920 | struct gfs2_glock_iter *gi = seq->private; |
1921 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
1922 | } |
1923 | ||
6802e340 | 1924 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1925 | { |
6802e340 | 1926 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1927 | } |
1928 | ||
4ef29002 | 1929 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
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 int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1937 | { | |
6802e340 SW |
1938 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1939 | sizeof(struct gfs2_glock_iter)); | |
1940 | if (ret == 0) { | |
1941 | struct seq_file *seq = file->private_data; | |
1942 | struct gfs2_glock_iter *gi = seq->private; | |
1943 | gi->sdp = inode->i_private; | |
1944 | } | |
1945 | return ret; | |
7c52b166 RP |
1946 | } |
1947 | ||
1948 | static const struct file_operations gfs2_debug_fops = { | |
1949 | .owner = THIS_MODULE, | |
1950 | .open = gfs2_debugfs_open, | |
1951 | .read = seq_read, | |
1952 | .llseek = seq_lseek, | |
6802e340 | 1953 | .release = seq_release_private, |
7c52b166 RP |
1954 | }; |
1955 | ||
1956 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1957 | { | |
5f882096 RP |
1958 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1959 | if (!sdp->debugfs_dir) | |
1960 | return -ENOMEM; | |
1961 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1962 | S_IFREG | S_IRUGO, | |
1963 | sdp->debugfs_dir, sdp, | |
1964 | &gfs2_debug_fops); | |
1965 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1966 | return -ENOMEM; |
1967 | ||
1968 | return 0; | |
1969 | } | |
1970 | ||
1971 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1972 | { | |
5f882096 RP |
1973 | if (sdp && sdp->debugfs_dir) { |
1974 | if (sdp->debugfs_dentry_glocks) { | |
1975 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1976 | sdp->debugfs_dentry_glocks = NULL; | |
1977 | } | |
1978 | debugfs_remove(sdp->debugfs_dir); | |
1979 | sdp->debugfs_dir = NULL; | |
1980 | } | |
7c52b166 RP |
1981 | } |
1982 | ||
1983 | int gfs2_register_debugfs(void) | |
1984 | { | |
1985 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1986 | return gfs2_root ? 0 : -ENOMEM; | |
1987 | } | |
1988 | ||
1989 | void gfs2_unregister_debugfs(void) | |
1990 | { | |
1991 | debugfs_remove(gfs2_root); | |
5f882096 | 1992 | gfs2_root = NULL; |
7c52b166 | 1993 | } |