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Commit | Line | Data |
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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> | |
b3b94faa DT |
13 | #include <linux/buffer_head.h> |
14 | #include <linux/delay.h> | |
15 | #include <linux/sort.h> | |
16 | #include <linux/jhash.h> | |
d0dc80db | 17 | #include <linux/kallsyms.h> |
5c676f6d | 18 | #include <linux/gfs2_ondisk.h> |
24264434 | 19 | #include <linux/list.h> |
fee852e3 | 20 | #include <linux/wait.h> |
95d97b7d | 21 | #include <linux/module.h> |
61be084e | 22 | #include <linux/rwsem.h> |
b3b94faa | 23 | #include <asm/uaccess.h> |
7c52b166 RP |
24 | #include <linux/seq_file.h> |
25 | #include <linux/debugfs.h> | |
8fbbfd21 SW |
26 | #include <linux/kthread.h> |
27 | #include <linux/freezer.h> | |
c4f68a13 BM |
28 | #include <linux/workqueue.h> |
29 | #include <linux/jiffies.h> | |
b3b94faa DT |
30 | |
31 | #include "gfs2.h" | |
5c676f6d | 32 | #include "incore.h" |
b3b94faa DT |
33 | #include "glock.h" |
34 | #include "glops.h" | |
35 | #include "inode.h" | |
b3b94faa DT |
36 | #include "lops.h" |
37 | #include "meta_io.h" | |
38 | #include "quota.h" | |
39 | #include "super.h" | |
5c676f6d | 40 | #include "util.h" |
813e0c46 | 41 | #include "bmap.h" |
63997775 SW |
42 | #define CREATE_TRACE_POINTS |
43 | #include "trace_gfs2.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; |
c4f68a13 | 65 | static struct workqueue_struct *glock_workqueue; |
b94a170e | 66 | struct workqueue_struct *gfs2_delete_workqueue; |
97cc1025 SW |
67 | static LIST_HEAD(lru_list); |
68 | static atomic_t lru_count = ATOMIC_INIT(0); | |
eb8374e7 | 69 | static DEFINE_SPINLOCK(lru_lock); |
08bc2dbc | 70 | |
b6397893 | 71 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
72 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
73 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
74 | ||
85d1da67 | 75 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 76 | static struct dentry *gfs2_root; |
087efdd3 SW |
77 | |
78 | /* | |
79 | * Despite what you might think, the numbers below are not arbitrary :-) | |
80 | * They are taken from the ipv4 routing hash code, which is well tested | |
81 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
82 | * but for now this should be fine. | |
83 | * | |
84 | * The reason for putting the locks in a separate array from the list heads | |
85 | * is that we can have fewer locks than list heads and save memory. We use | |
86 | * the same hash function for both, but with a different hash mask. | |
87 | */ | |
88 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
89 | defined(CONFIG_PROVE_LOCKING) | |
90 | ||
91 | #ifdef CONFIG_LOCKDEP | |
92 | # define GL_HASH_LOCK_SZ 256 | |
93 | #else | |
94 | # if NR_CPUS >= 32 | |
95 | # define GL_HASH_LOCK_SZ 4096 | |
96 | # elif NR_CPUS >= 16 | |
97 | # define GL_HASH_LOCK_SZ 2048 | |
98 | # elif NR_CPUS >= 8 | |
99 | # define GL_HASH_LOCK_SZ 1024 | |
100 | # elif NR_CPUS >= 4 | |
101 | # define GL_HASH_LOCK_SZ 512 | |
102 | # else | |
103 | # define GL_HASH_LOCK_SZ 256 | |
104 | # endif | |
105 | #endif | |
106 | ||
107 | /* We never want more locks than chains */ | |
108 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
109 | # undef GL_HASH_LOCK_SZ | |
110 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
111 | #endif | |
112 | ||
113 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
114 | ||
115 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
116 | { | |
94610610 | 117 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
118 | } |
119 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 120 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
121 | { |
122 | return NULL; | |
123 | } | |
124 | #endif | |
85d1da67 | 125 | |
b3b94faa DT |
126 | /** |
127 | * gl_hash() - Turn glock number into hash bucket number | |
128 | * @lock: The glock number | |
129 | * | |
130 | * Returns: The number of the corresponding hash bucket | |
131 | */ | |
132 | ||
b8547856 SW |
133 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
134 | const struct lm_lockname *name) | |
b3b94faa DT |
135 | { |
136 | unsigned int h; | |
137 | ||
cd915493 | 138 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 139 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 140 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
141 | h &= GFS2_GL_HASH_MASK; |
142 | ||
143 | return h; | |
144 | } | |
145 | ||
146 | /** | |
147 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
148 | * @gl: The glock to release | |
149 | * | |
150 | * Also calls lock module to release its internal structure for this glock. | |
151 | * | |
152 | */ | |
153 | ||
154 | static void glock_free(struct gfs2_glock *gl) | |
155 | { | |
156 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
009d8518 SW |
157 | struct address_space *mapping = gfs2_glock2aspace(gl); |
158 | struct kmem_cache *cachep = gfs2_glock_cachep; | |
b3b94faa | 159 | |
009d8518 | 160 | GLOCK_BUG_ON(gl, mapping && mapping->nrpages); |
63997775 | 161 | trace_gfs2_glock_put(gl); |
009d8518 SW |
162 | if (mapping) |
163 | cachep = gfs2_glock_aspace_cachep; | |
164 | sdp->sd_lockstruct.ls_ops->lm_put_lock(cachep, gl); | |
b3b94faa DT |
165 | } |
166 | ||
167 | /** | |
168 | * gfs2_glock_hold() - increment reference count on glock | |
169 | * @gl: The glock to hold | |
170 | * | |
171 | */ | |
172 | ||
b94a170e | 173 | void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 174 | { |
d8348de0 | 175 | GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
16feb9fe | 176 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
177 | } |
178 | ||
8ff22a6f BM |
179 | /** |
180 | * demote_ok - Check to see if it's ok to unlock a glock | |
181 | * @gl: the glock | |
182 | * | |
183 | * Returns: 1 if it's ok | |
184 | */ | |
185 | ||
186 | static int demote_ok(const struct gfs2_glock *gl) | |
187 | { | |
188 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
189 | ||
190 | if (gl->gl_state == LM_ST_UNLOCKED) | |
191 | return 0; | |
192 | if (!list_empty(&gl->gl_holders)) | |
193 | return 0; | |
194 | if (glops->go_demote_ok) | |
195 | return glops->go_demote_ok(gl); | |
196 | return 1; | |
197 | } | |
198 | ||
97cc1025 SW |
199 | /** |
200 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
201 | * @gl: the glock | |
202 | * | |
203 | */ | |
204 | ||
205 | static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
206 | { | |
8ff22a6f BM |
207 | int may_reclaim; |
208 | may_reclaim = (demote_ok(gl) && | |
209 | (atomic_read(&gl->gl_ref) == 1 || | |
210 | (gl->gl_name.ln_type == LM_TYPE_INODE && | |
211 | atomic_read(&gl->gl_ref) <= 2))); | |
97cc1025 | 212 | spin_lock(&lru_lock); |
8ff22a6f | 213 | if (list_empty(&gl->gl_lru) && may_reclaim) { |
97cc1025 SW |
214 | list_add_tail(&gl->gl_lru, &lru_list); |
215 | atomic_inc(&lru_count); | |
216 | } | |
217 | spin_unlock(&lru_lock); | |
218 | } | |
219 | ||
8ff22a6f BM |
220 | /** |
221 | * gfs2_glock_put_nolock() - Decrement reference count on glock | |
222 | * @gl: The glock to put | |
223 | * | |
224 | * This function should only be used if the caller has its own reference | |
225 | * to the glock, in addition to the one it is dropping. | |
226 | */ | |
227 | ||
b94a170e | 228 | void gfs2_glock_put_nolock(struct gfs2_glock *gl) |
8ff22a6f BM |
229 | { |
230 | if (atomic_dec_and_test(&gl->gl_ref)) | |
231 | GLOCK_BUG_ON(gl, 1); | |
232 | gfs2_glock_schedule_for_reclaim(gl); | |
233 | } | |
234 | ||
b3b94faa DT |
235 | /** |
236 | * gfs2_glock_put() - Decrement reference count on glock | |
237 | * @gl: The glock to put | |
238 | * | |
239 | */ | |
240 | ||
241 | int gfs2_glock_put(struct gfs2_glock *gl) | |
242 | { | |
b3b94faa DT |
243 | int rv = 0; |
244 | ||
087efdd3 | 245 | write_lock(gl_lock_addr(gl->gl_hash)); |
26bb7505 | 246 | if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) { |
b6397893 | 247 | hlist_del(&gl->gl_list); |
97cc1025 SW |
248 | if (!list_empty(&gl->gl_lru)) { |
249 | list_del_init(&gl->gl_lru); | |
250 | atomic_dec(&lru_count); | |
251 | } | |
252 | spin_unlock(&lru_lock); | |
26bb7505 | 253 | write_unlock(gl_lock_addr(gl->gl_hash)); |
6802e340 | 254 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
b3b94faa DT |
255 | glock_free(gl); |
256 | rv = 1; | |
257 | goto out; | |
258 | } | |
8ff22a6f BM |
259 | spin_lock(&gl->gl_spin); |
260 | gfs2_glock_schedule_for_reclaim(gl); | |
261 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 262 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 263 | out: |
b3b94faa DT |
264 | return rv; |
265 | } | |
266 | ||
b3b94faa DT |
267 | /** |
268 | * search_bucket() - Find struct gfs2_glock by lock number | |
269 | * @bucket: the bucket to search | |
270 | * @name: The lock name | |
271 | * | |
272 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
273 | */ | |
274 | ||
37b2fa6a | 275 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 276 | const struct gfs2_sbd *sdp, |
d6a53727 | 277 | const struct lm_lockname *name) |
b3b94faa DT |
278 | { |
279 | struct gfs2_glock *gl; | |
b6397893 | 280 | struct hlist_node *h; |
b3b94faa | 281 | |
b6397893 | 282 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
283 | if (!lm_name_equal(&gl->gl_name, name)) |
284 | continue; | |
899be4d3 SW |
285 | if (gl->gl_sbd != sdp) |
286 | continue; | |
b3b94faa | 287 | |
16feb9fe | 288 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
289 | |
290 | return gl; | |
291 | } | |
292 | ||
293 | return NULL; | |
294 | } | |
295 | ||
6802e340 SW |
296 | /** |
297 | * may_grant - check if its ok to grant a new lock | |
298 | * @gl: The glock | |
299 | * @gh: The lock request which we wish to grant | |
300 | * | |
301 | * Returns: true if its ok to grant the lock | |
302 | */ | |
303 | ||
304 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
305 | { | |
306 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
307 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
308 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
309 | return 0; | |
310 | if (gl->gl_state == gh->gh_state) | |
311 | return 1; | |
312 | if (gh->gh_flags & GL_EXACT) | |
313 | return 0; | |
209806ab SW |
314 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
315 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
316 | return 1; | |
317 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
318 | return 1; | |
319 | } | |
6802e340 SW |
320 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
321 | return 1; | |
322 | return 0; | |
323 | } | |
324 | ||
325 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
326 | { | |
327 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
328 | smp_mb__after_clear_bit(); | |
329 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
330 | } | |
331 | ||
332 | /** | |
333 | * do_promote - promote as many requests as possible on the current queue | |
334 | * @gl: The glock | |
335 | * | |
813e0c46 SW |
336 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
337 | * if a type specific operation is underway. | |
6802e340 SW |
338 | */ |
339 | ||
340 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
341 | __releases(&gl->gl_spin) |
342 | __acquires(&gl->gl_spin) | |
6802e340 SW |
343 | { |
344 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
345 | struct gfs2_holder *gh, *tmp; | |
346 | int ret; | |
347 | ||
348 | restart: | |
349 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
350 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
351 | continue; | |
352 | if (may_grant(gl, gh)) { | |
353 | if (gh->gh_list.prev == &gl->gl_holders && | |
354 | glops->go_lock) { | |
355 | spin_unlock(&gl->gl_spin); | |
356 | /* FIXME: eliminate this eventually */ | |
357 | ret = glops->go_lock(gh); | |
358 | spin_lock(&gl->gl_spin); | |
359 | if (ret) { | |
813e0c46 SW |
360 | if (ret == 1) |
361 | return 2; | |
6802e340 SW |
362 | gh->gh_error = ret; |
363 | list_del_init(&gh->gh_list); | |
63997775 | 364 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
365 | gfs2_holder_wake(gh); |
366 | goto restart; | |
367 | } | |
368 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 369 | trace_gfs2_promote(gh, 1); |
6802e340 SW |
370 | gfs2_holder_wake(gh); |
371 | goto restart; | |
372 | } | |
373 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 374 | trace_gfs2_promote(gh, 0); |
6802e340 SW |
375 | gfs2_holder_wake(gh); |
376 | continue; | |
377 | } | |
378 | if (gh->gh_list.prev == &gl->gl_holders) | |
379 | return 1; | |
380 | break; | |
381 | } | |
382 | return 0; | |
383 | } | |
384 | ||
385 | /** | |
386 | * do_error - Something unexpected has happened during a lock request | |
387 | * | |
388 | */ | |
389 | ||
390 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
391 | { | |
392 | struct gfs2_holder *gh, *tmp; | |
393 | ||
394 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
395 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
396 | continue; | |
397 | if (ret & LM_OUT_ERROR) | |
398 | gh->gh_error = -EIO; | |
399 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
400 | gh->gh_error = GLR_TRYFAILED; | |
401 | else | |
402 | continue; | |
403 | list_del_init(&gh->gh_list); | |
63997775 | 404 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
405 | gfs2_holder_wake(gh); |
406 | } | |
407 | } | |
408 | ||
409 | /** | |
410 | * find_first_waiter - find the first gh that's waiting for the glock | |
411 | * @gl: the glock | |
412 | */ | |
413 | ||
414 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
415 | { | |
416 | struct gfs2_holder *gh; | |
417 | ||
418 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
419 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
420 | return gh; | |
421 | } | |
422 | return NULL; | |
423 | } | |
424 | ||
425 | /** | |
426 | * state_change - record that the glock is now in a different state | |
427 | * @gl: the glock | |
428 | * @new_state the new state | |
429 | * | |
430 | */ | |
431 | ||
432 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
433 | { | |
434 | int held1, held2; | |
435 | ||
436 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
437 | held2 = (new_state != LM_ST_UNLOCKED); | |
438 | ||
439 | if (held1 != held2) { | |
440 | if (held2) | |
441 | gfs2_glock_hold(gl); | |
442 | else | |
8ff22a6f | 443 | gfs2_glock_put_nolock(gl); |
6802e340 SW |
444 | } |
445 | ||
446 | gl->gl_state = new_state; | |
447 | gl->gl_tchange = jiffies; | |
448 | } | |
449 | ||
450 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
451 | { | |
452 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
453 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
454 | smp_mb__after_clear_bit(); | |
455 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
456 | } | |
457 | ||
458 | /** | |
459 | * finish_xmote - The DLM has replied to one of our lock requests | |
460 | * @gl: The glock | |
461 | * @ret: The status from the DLM | |
462 | * | |
463 | */ | |
464 | ||
465 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
466 | { | |
467 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
468 | struct gfs2_holder *gh; | |
469 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 470 | int rv; |
6802e340 SW |
471 | |
472 | spin_lock(&gl->gl_spin); | |
63997775 | 473 | trace_gfs2_glock_state_change(gl, state); |
6802e340 SW |
474 | state_change(gl, state); |
475 | gh = find_first_waiter(gl); | |
476 | ||
477 | /* Demote to UN request arrived during demote to SH or DF */ | |
478 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
479 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
480 | gl->gl_target = LM_ST_UNLOCKED; | |
481 | ||
482 | /* Check for state != intended state */ | |
483 | if (unlikely(state != gl->gl_target)) { | |
484 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
485 | /* move to back of queue and try next entry */ | |
486 | if (ret & LM_OUT_CANCELED) { | |
487 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
488 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
489 | gh = find_first_waiter(gl); | |
490 | gl->gl_target = gh->gh_state; | |
491 | goto retry; | |
492 | } | |
493 | /* Some error or failed "try lock" - report it */ | |
494 | if ((ret & LM_OUT_ERROR) || | |
495 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
496 | gl->gl_target = gl->gl_state; | |
497 | do_error(gl, ret); | |
498 | goto out; | |
499 | } | |
500 | } | |
501 | switch(state) { | |
502 | /* Unlocked due to conversion deadlock, try again */ | |
503 | case LM_ST_UNLOCKED: | |
504 | retry: | |
505 | do_xmote(gl, gh, gl->gl_target); | |
506 | break; | |
507 | /* Conversion fails, unlock and try again */ | |
508 | case LM_ST_SHARED: | |
509 | case LM_ST_DEFERRED: | |
510 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
511 | break; | |
512 | default: /* Everything else */ | |
513 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
514 | GLOCK_BUG_ON(gl, 1); | |
515 | } | |
516 | spin_unlock(&gl->gl_spin); | |
6802e340 SW |
517 | return; |
518 | } | |
519 | ||
520 | /* Fast path - we got what we asked for */ | |
521 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
522 | gfs2_demote_wake(gl); | |
523 | if (state != LM_ST_UNLOCKED) { | |
524 | if (glops->go_xmote_bh) { | |
6802e340 SW |
525 | spin_unlock(&gl->gl_spin); |
526 | rv = glops->go_xmote_bh(gl, gh); | |
6802e340 SW |
527 | spin_lock(&gl->gl_spin); |
528 | if (rv) { | |
529 | do_error(gl, rv); | |
530 | goto out; | |
531 | } | |
532 | } | |
813e0c46 SW |
533 | rv = do_promote(gl); |
534 | if (rv == 2) | |
535 | goto out_locked; | |
6802e340 SW |
536 | } |
537 | out: | |
538 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 539 | out_locked: |
6802e340 | 540 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
541 | } |
542 | ||
543 | static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, | |
f057f6cd | 544 | unsigned int req_state, |
6802e340 SW |
545 | unsigned int flags) |
546 | { | |
547 | int ret = LM_OUT_ERROR; | |
048bca22 SW |
548 | |
549 | if (!sdp->sd_lockstruct.ls_ops->lm_lock) | |
550 | return req_state == LM_ST_UNLOCKED ? 0 : req_state; | |
551 | ||
6802e340 | 552 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
f057f6cd | 553 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, |
6802e340 SW |
554 | req_state, flags); |
555 | return ret; | |
556 | } | |
557 | ||
558 | /** | |
559 | * do_xmote - Calls the DLM to change the state of a lock | |
560 | * @gl: The lock state | |
561 | * @gh: The holder (only for promotes) | |
562 | * @target: The target lock state | |
563 | * | |
564 | */ | |
565 | ||
566 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
567 | __releases(&gl->gl_spin) |
568 | __acquires(&gl->gl_spin) | |
6802e340 SW |
569 | { |
570 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
571 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
572 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
573 | int ret; | |
574 | ||
575 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
576 | LM_FLAG_PRIORITY); | |
577 | BUG_ON(gl->gl_state == target); | |
578 | BUG_ON(gl->gl_state == gl->gl_target); | |
579 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
580 | glops->go_inval) { | |
581 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
582 | do_error(gl, 0); /* Fail queued try locks */ | |
583 | } | |
584 | spin_unlock(&gl->gl_spin); | |
585 | if (glops->go_xmote_th) | |
586 | glops->go_xmote_th(gl); | |
587 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
588 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
589 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
590 | ||
591 | gfs2_glock_hold(gl); | |
592 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
593 | gl->gl_state == LM_ST_DEFERRED) && | |
594 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
595 | lck_flags |= LM_FLAG_TRY_1CB; | |
f057f6cd | 596 | ret = gfs2_lm_lock(sdp, gl, target, lck_flags); |
6802e340 SW |
597 | |
598 | if (!(ret & LM_OUT_ASYNC)) { | |
599 | finish_xmote(gl, ret); | |
6802e340 SW |
600 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
601 | gfs2_glock_put(gl); | |
602 | } else { | |
603 | GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); | |
604 | } | |
605 | spin_lock(&gl->gl_spin); | |
606 | } | |
607 | ||
608 | /** | |
609 | * find_first_holder - find the first "holder" gh | |
610 | * @gl: the glock | |
611 | */ | |
612 | ||
613 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
614 | { | |
615 | struct gfs2_holder *gh; | |
616 | ||
617 | if (!list_empty(&gl->gl_holders)) { | |
618 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
619 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
620 | return gh; | |
621 | } | |
622 | return NULL; | |
623 | } | |
624 | ||
625 | /** | |
626 | * run_queue - do all outstanding tasks related to a glock | |
627 | * @gl: The glock in question | |
628 | * @nonblock: True if we must not block in run_queue | |
629 | * | |
630 | */ | |
631 | ||
632 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
633 | __releases(&gl->gl_spin) |
634 | __acquires(&gl->gl_spin) | |
6802e340 SW |
635 | { |
636 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 637 | int ret; |
6802e340 SW |
638 | |
639 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
640 | return; | |
641 | ||
642 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
643 | ||
644 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
645 | gl->gl_demote_state != gl->gl_state) { | |
646 | if (find_first_holder(gl)) | |
d8348de0 | 647 | goto out_unlock; |
6802e340 SW |
648 | if (nonblock) |
649 | goto out_sched; | |
650 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 651 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
652 | gl->gl_target = gl->gl_demote_state; |
653 | } else { | |
654 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
655 | gfs2_demote_wake(gl); | |
813e0c46 SW |
656 | ret = do_promote(gl); |
657 | if (ret == 0) | |
d8348de0 | 658 | goto out_unlock; |
813e0c46 | 659 | if (ret == 2) |
a228df63 | 660 | goto out; |
6802e340 SW |
661 | gh = find_first_waiter(gl); |
662 | gl->gl_target = gh->gh_state; | |
663 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
664 | do_error(gl, 0); /* Fail queued try locks */ | |
665 | } | |
666 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 667 | out: |
6802e340 SW |
668 | return; |
669 | ||
670 | out_sched: | |
7e71c55e SW |
671 | clear_bit(GLF_LOCK, &gl->gl_flags); |
672 | smp_mb__after_clear_bit(); | |
6802e340 SW |
673 | gfs2_glock_hold(gl); |
674 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
8ff22a6f | 675 | gfs2_glock_put_nolock(gl); |
7e71c55e SW |
676 | return; |
677 | ||
d8348de0 | 678 | out_unlock: |
6802e340 | 679 | clear_bit(GLF_LOCK, &gl->gl_flags); |
7e71c55e SW |
680 | smp_mb__after_clear_bit(); |
681 | return; | |
6802e340 SW |
682 | } |
683 | ||
b94a170e BM |
684 | static void delete_work_func(struct work_struct *work) |
685 | { | |
686 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); | |
687 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
688 | struct gfs2_inode *ip = NULL; | |
689 | struct inode *inode; | |
690 | u64 no_addr = 0; | |
691 | ||
692 | spin_lock(&gl->gl_spin); | |
693 | ip = (struct gfs2_inode *)gl->gl_object; | |
694 | if (ip) | |
695 | no_addr = ip->i_no_addr; | |
696 | spin_unlock(&gl->gl_spin); | |
697 | if (ip) { | |
698 | inode = gfs2_ilookup(sdp->sd_vfs, no_addr); | |
699 | if (inode) { | |
700 | d_prune_aliases(inode); | |
701 | iput(inode); | |
702 | } | |
703 | } | |
704 | gfs2_glock_put(gl); | |
705 | } | |
706 | ||
c4f68a13 BM |
707 | static void glock_work_func(struct work_struct *work) |
708 | { | |
6802e340 | 709 | unsigned long delay = 0; |
c4f68a13 | 710 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
26bb7505 | 711 | int drop_ref = 0; |
c4f68a13 | 712 | |
26bb7505 | 713 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
6802e340 | 714 | finish_xmote(gl, gl->gl_reply); |
26bb7505 SW |
715 | drop_ref = 1; |
716 | } | |
a228df63 | 717 | down_read(&gfs2_umount_flush_sem); |
c4f68a13 | 718 | spin_lock(&gl->gl_spin); |
265d529c SW |
719 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
720 | gl->gl_state != LM_ST_UNLOCKED && | |
721 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
722 | unsigned long holdtime, now = jiffies; |
723 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
724 | if (time_before(now, holdtime)) | |
725 | delay = holdtime - now; | |
726 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
727 | } | |
728 | run_queue(gl, 0); | |
c4f68a13 | 729 | spin_unlock(&gl->gl_spin); |
a228df63 | 730 | up_read(&gfs2_umount_flush_sem); |
6802e340 SW |
731 | if (!delay || |
732 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
733 | gfs2_glock_put(gl); | |
26bb7505 SW |
734 | if (drop_ref) |
735 | gfs2_glock_put(gl); | |
c4f68a13 BM |
736 | } |
737 | ||
b3b94faa DT |
738 | /** |
739 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
740 | * @sdp: The GFS2 superblock | |
741 | * @number: the lock number | |
742 | * @glops: The glock_operations to use | |
743 | * @create: If 0, don't create the glock if it doesn't exist | |
744 | * @glp: the glock is returned here | |
745 | * | |
746 | * This does not lock a glock, just finds/creates structures for one. | |
747 | * | |
748 | * Returns: errno | |
749 | */ | |
750 | ||
cd915493 | 751 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 752 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
753 | struct gfs2_glock **glp) |
754 | { | |
009d8518 | 755 | struct super_block *s = sdp->sd_vfs; |
37b2fa6a | 756 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 757 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 758 | unsigned int hash = gl_hash(sdp, &name); |
009d8518 | 759 | struct address_space *mapping; |
b3b94faa | 760 | |
087efdd3 | 761 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 762 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 763 | read_unlock(gl_lock_addr(hash)); |
b3b94faa | 764 | |
64d576ba SW |
765 | *glp = gl; |
766 | if (gl) | |
b3b94faa | 767 | return 0; |
64d576ba SW |
768 | if (!create) |
769 | return -ENOENT; | |
b3b94faa | 770 | |
009d8518 SW |
771 | if (glops->go_flags & GLOF_ASPACE) |
772 | gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL); | |
773 | else | |
774 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
b3b94faa DT |
775 | if (!gl) |
776 | return -ENOMEM; | |
777 | ||
8f05228e | 778 | atomic_inc(&sdp->sd_glock_disposal); |
ec45d9f5 | 779 | gl->gl_flags = 0; |
b3b94faa | 780 | gl->gl_name = name; |
16feb9fe | 781 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 782 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 783 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 784 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 785 | gl->gl_hash = hash; |
b3b94faa | 786 | gl->gl_ops = glops; |
f057f6cd SW |
787 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
788 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
789 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 790 | gl->gl_tchange = jiffies; |
ec45d9f5 | 791 | gl->gl_object = NULL; |
b3b94faa | 792 | gl->gl_sbd = sdp; |
c4f68a13 | 793 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b94a170e | 794 | INIT_WORK(&gl->gl_delete, delete_work_func); |
b3b94faa | 795 | |
009d8518 SW |
796 | mapping = gfs2_glock2aspace(gl); |
797 | if (mapping) { | |
798 | mapping->a_ops = &gfs2_meta_aops; | |
799 | mapping->host = s->s_bdev->bd_inode; | |
800 | mapping->flags = 0; | |
801 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
802 | mapping->assoc_mapping = NULL; | |
803 | mapping->backing_dev_info = s->s_bdi; | |
804 | mapping->writeback_index = 0; | |
b3b94faa DT |
805 | } |
806 | ||
087efdd3 | 807 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 808 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 809 | if (tmp) { |
087efdd3 | 810 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
811 | glock_free(gl); |
812 | gl = tmp; | |
813 | } else { | |
b6397893 | 814 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 815 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
816 | } |
817 | ||
818 | *glp = gl; | |
819 | ||
820 | return 0; | |
b3b94faa DT |
821 | } |
822 | ||
823 | /** | |
824 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
825 | * @gl: the glock | |
826 | * @state: the state we're requesting | |
827 | * @flags: the modifier flags | |
828 | * @gh: the holder structure | |
829 | * | |
830 | */ | |
831 | ||
190562bd | 832 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
833 | struct gfs2_holder *gh) |
834 | { | |
835 | INIT_LIST_HEAD(&gh->gh_list); | |
836 | gh->gh_gl = gl; | |
d0dc80db | 837 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 838 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
839 | gh->gh_state = state; |
840 | gh->gh_flags = flags; | |
841 | gh->gh_error = 0; | |
842 | gh->gh_iflags = 0; | |
b3b94faa DT |
843 | gfs2_glock_hold(gl); |
844 | } | |
845 | ||
846 | /** | |
847 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
848 | * @state: the state we're requesting | |
849 | * @flags: the modifier flags | |
850 | * @gh: the holder structure | |
851 | * | |
852 | * Don't mess with the glock. | |
853 | * | |
854 | */ | |
855 | ||
190562bd | 856 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
857 | { |
858 | gh->gh_state = state; | |
579b78a4 | 859 | gh->gh_flags = flags; |
3b8249f6 | 860 | gh->gh_iflags = 0; |
d0dc80db | 861 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
862 | } |
863 | ||
864 | /** | |
865 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
866 | * @gh: the holder structure | |
867 | * | |
868 | */ | |
869 | ||
870 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
871 | { | |
b1e058da | 872 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
873 | gfs2_glock_put(gh->gh_gl); |
874 | gh->gh_gl = NULL; | |
d0dc80db | 875 | gh->gh_ip = 0; |
b3b94faa DT |
876 | } |
877 | ||
fe64d517 SW |
878 | /** |
879 | * gfs2_glock_holder_wait | |
880 | * @word: unused | |
881 | * | |
882 | * This function and gfs2_glock_demote_wait both show up in the WCHAN | |
883 | * field. Thus I've separated these otherwise identical functions in | |
884 | * order to be more informative to the user. | |
885 | */ | |
886 | ||
887 | static int gfs2_glock_holder_wait(void *word) | |
fee852e3 SW |
888 | { |
889 | schedule(); | |
890 | return 0; | |
891 | } | |
892 | ||
fe64d517 SW |
893 | static int gfs2_glock_demote_wait(void *word) |
894 | { | |
895 | schedule(); | |
896 | return 0; | |
897 | } | |
898 | ||
6802e340 | 899 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 900 | { |
6802e340 | 901 | might_sleep(); |
fe64d517 | 902 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
da755fdb SW |
903 | } |
904 | ||
6802e340 | 905 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 906 | { |
6802e340 | 907 | might_sleep(); |
fe64d517 | 908 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
b3b94faa DT |
909 | } |
910 | ||
911 | /** | |
6802e340 SW |
912 | * handle_callback - process a demote request |
913 | * @gl: the glock | |
914 | * @state: the state the caller wants us to change to | |
b3b94faa | 915 | * |
6802e340 SW |
916 | * There are only two requests that we are going to see in actual |
917 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
918 | */ |
919 | ||
6802e340 | 920 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 921 | unsigned long delay) |
b3b94faa | 922 | { |
6802e340 | 923 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 924 | |
6802e340 SW |
925 | set_bit(bit, &gl->gl_flags); |
926 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
927 | gl->gl_demote_state = state; | |
928 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
929 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
930 | gl->gl_demote_state != state) { | |
931 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 932 | } |
b94a170e BM |
933 | if (gl->gl_ops->go_callback) |
934 | gl->gl_ops->go_callback(gl); | |
63997775 | 935 | trace_gfs2_demote_rq(gl); |
b3b94faa DT |
936 | } |
937 | ||
938 | /** | |
6802e340 | 939 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
940 | * @gh: the glock holder |
941 | * | |
942 | * Returns: 0 on success | |
943 | */ | |
944 | ||
6802e340 | 945 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 946 | { |
fee852e3 | 947 | wait_on_holder(gh); |
b3b94faa DT |
948 | return gh->gh_error; |
949 | } | |
950 | ||
6802e340 | 951 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 RP |
952 | { |
953 | va_list args; | |
954 | ||
955 | va_start(args, fmt); | |
6802e340 SW |
956 | if (seq) { |
957 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 958 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
959 | seq_printf(seq, gi->string); |
960 | } else { | |
961 | printk(KERN_ERR " "); | |
7c52b166 | 962 | vprintk(fmt, args); |
6802e340 | 963 | } |
7c52b166 RP |
964 | va_end(args); |
965 | } | |
966 | ||
b3b94faa DT |
967 | /** |
968 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
969 | * @gh: the holder structure to add | |
970 | * | |
6802e340 SW |
971 | * Eventually we should move the recursive locking trap to a |
972 | * debugging option or something like that. This is the fast | |
973 | * path and needs to have the minimum number of distractions. | |
974 | * | |
b3b94faa DT |
975 | */ |
976 | ||
6802e340 | 977 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
978 | __releases(&gl->gl_spin) |
979 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
980 | { |
981 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
982 | struct gfs2_sbd *sdp = gl->gl_sbd; |
983 | struct list_head *insert_pt = NULL; | |
984 | struct gfs2_holder *gh2; | |
985 | int try_lock = 0; | |
b3b94faa | 986 | |
b1e058da | 987 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
988 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
989 | BUG(); | |
190562bd | 990 | |
6802e340 SW |
991 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
992 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
993 | try_lock = 1; | |
994 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
995 | goto fail; | |
996 | } | |
997 | ||
998 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
999 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
1000 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
1001 | goto trap_recursive; | |
1002 | if (try_lock && | |
1003 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
1004 | !may_grant(gl, gh)) { | |
1005 | fail: | |
1006 | gh->gh_error = GLR_TRYFAILED; | |
1007 | gfs2_holder_wake(gh); | |
1008 | return; | |
b4c20166 | 1009 | } |
6802e340 SW |
1010 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
1011 | continue; | |
1012 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
1013 | insert_pt = &gh2->gh_list; | |
1014 | } | |
1015 | if (likely(insert_pt == NULL)) { | |
1016 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
1017 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
1018 | goto do_cancel; | |
1019 | return; | |
1020 | } | |
63997775 | 1021 | trace_gfs2_glock_queue(gh, 1); |
6802e340 SW |
1022 | list_add_tail(&gh->gh_list, insert_pt); |
1023 | do_cancel: | |
1024 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
1025 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
1026 | spin_unlock(&gl->gl_spin); | |
048bca22 | 1027 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 1028 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 1029 | spin_lock(&gl->gl_spin); |
b3b94faa | 1030 | } |
6802e340 | 1031 | return; |
b3b94faa | 1032 | |
6802e340 SW |
1033 | trap_recursive: |
1034 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
1035 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
1036 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1037 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
1038 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
1039 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
1040 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1041 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
1042 | __dump_glock(NULL, gl); | |
1043 | BUG(); | |
b3b94faa DT |
1044 | } |
1045 | ||
1046 | /** | |
1047 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1048 | * @gh: the holder structure | |
1049 | * | |
1050 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1051 | * | |
1052 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1053 | */ | |
1054 | ||
1055 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1056 | { | |
1057 | struct gfs2_glock *gl = gh->gh_gl; | |
1058 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1059 | int error = 0; | |
1060 | ||
6802e340 | 1061 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 1062 | return -EIO; |
b3b94faa | 1063 | |
b3b94faa DT |
1064 | spin_lock(&gl->gl_spin); |
1065 | add_to_queue(gh); | |
6802e340 | 1066 | run_queue(gl, 1); |
b3b94faa DT |
1067 | spin_unlock(&gl->gl_spin); |
1068 | ||
6802e340 SW |
1069 | if (!(gh->gh_flags & GL_ASYNC)) |
1070 | error = gfs2_glock_wait(gh); | |
b3b94faa | 1071 | |
b3b94faa DT |
1072 | return error; |
1073 | } | |
1074 | ||
1075 | /** | |
1076 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1077 | * @gh: the holder | |
1078 | * | |
1079 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1080 | */ | |
1081 | ||
1082 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1083 | { | |
6802e340 | 1084 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1085 | } |
1086 | ||
1087 | /** | |
1088 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1089 | * @gh: the glock holder | |
1090 | * | |
1091 | */ | |
1092 | ||
1093 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1094 | { | |
1095 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1096 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1097 | unsigned delay = 0; |
6802e340 | 1098 | int fast_path = 0; |
b3b94faa | 1099 | |
6802e340 | 1100 | spin_lock(&gl->gl_spin); |
b3b94faa | 1101 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1102 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1103 | |
b3b94faa | 1104 | list_del_init(&gh->gh_list); |
6802e340 | 1105 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1106 | if (glops->go_unlock) { |
6802e340 | 1107 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1108 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1109 | glops->go_unlock(gh); |
3042a2cc | 1110 | spin_lock(&gl->gl_spin); |
6802e340 | 1111 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1112 | } |
6802e340 SW |
1113 | if (list_empty(&gl->gl_holders) && |
1114 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1115 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1116 | fast_path = 1; | |
b3b94faa | 1117 | } |
63997775 | 1118 | trace_gfs2_glock_queue(gh, 0); |
b3b94faa | 1119 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1120 | if (likely(fast_path)) |
1121 | return; | |
c4f68a13 BM |
1122 | |
1123 | gfs2_glock_hold(gl); | |
1124 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1125 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1126 | delay = gl->gl_ops->go_min_hold_time; | |
1127 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1128 | gfs2_glock_put(gl); | |
b3b94faa DT |
1129 | } |
1130 | ||
d93cfa98 AD |
1131 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1132 | { | |
1133 | struct gfs2_glock *gl = gh->gh_gl; | |
1134 | gfs2_glock_dq(gh); | |
1135 | wait_on_demote(gl); | |
1136 | } | |
1137 | ||
b3b94faa DT |
1138 | /** |
1139 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1140 | * @gh: the holder structure | |
1141 | * | |
1142 | */ | |
1143 | ||
1144 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1145 | { | |
1146 | gfs2_glock_dq(gh); | |
1147 | gfs2_holder_uninit(gh); | |
1148 | } | |
1149 | ||
1150 | /** | |
1151 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1152 | * @sdp: the filesystem | |
1153 | * @number: the lock number | |
1154 | * @glops: the glock operations for the type of glock | |
1155 | * @state: the state to acquire the glock in | |
1156 | * @flags: modifier flags for the aquisition | |
1157 | * @gh: the struct gfs2_holder | |
1158 | * | |
1159 | * Returns: errno | |
1160 | */ | |
1161 | ||
cd915493 | 1162 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1163 | const struct gfs2_glock_operations *glops, |
1164 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1165 | { |
1166 | struct gfs2_glock *gl; | |
1167 | int error; | |
1168 | ||
1169 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1170 | if (!error) { | |
1171 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1172 | gfs2_glock_put(gl); | |
1173 | } | |
1174 | ||
1175 | return error; | |
1176 | } | |
1177 | ||
1178 | /** | |
1179 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1180 | * @arg_a: the first structure | |
1181 | * @arg_b: the second structure | |
1182 | * | |
1183 | */ | |
1184 | ||
1185 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1186 | { | |
a5e08a9e SW |
1187 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1188 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1189 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1190 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1191 | |
1192 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1193 | return 1; |
1194 | if (a->ln_number < b->ln_number) | |
1195 | return -1; | |
1c0f4872 | 1196 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1197 | return 0; |
b3b94faa DT |
1198 | } |
1199 | ||
1200 | /** | |
1201 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1202 | * @num_gh: the number of structures | |
1203 | * @ghs: an array of struct gfs2_holder structures | |
1204 | * | |
1205 | * Returns: 0 on success (all glocks acquired), | |
1206 | * errno on failure (no glocks acquired) | |
1207 | */ | |
1208 | ||
1209 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1210 | struct gfs2_holder **p) | |
1211 | { | |
1212 | unsigned int x; | |
1213 | int error = 0; | |
1214 | ||
1215 | for (x = 0; x < num_gh; x++) | |
1216 | p[x] = &ghs[x]; | |
1217 | ||
1218 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1219 | ||
1220 | for (x = 0; x < num_gh; x++) { | |
1221 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1222 | ||
1223 | error = gfs2_glock_nq(p[x]); | |
1224 | if (error) { | |
1225 | while (x--) | |
1226 | gfs2_glock_dq(p[x]); | |
1227 | break; | |
1228 | } | |
1229 | } | |
1230 | ||
1231 | return error; | |
1232 | } | |
1233 | ||
1234 | /** | |
1235 | * gfs2_glock_nq_m - acquire multiple glocks | |
1236 | * @num_gh: the number of structures | |
1237 | * @ghs: an array of struct gfs2_holder structures | |
1238 | * | |
b3b94faa DT |
1239 | * |
1240 | * Returns: 0 on success (all glocks acquired), | |
1241 | * errno on failure (no glocks acquired) | |
1242 | */ | |
1243 | ||
1244 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1245 | { | |
eaf5bd3c SW |
1246 | struct gfs2_holder *tmp[4]; |
1247 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1248 | int error = 0; |
1249 | ||
eaf5bd3c SW |
1250 | switch(num_gh) { |
1251 | case 0: | |
b3b94faa | 1252 | return 0; |
eaf5bd3c | 1253 | case 1: |
b3b94faa DT |
1254 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1255 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1256 | default: |
1257 | if (num_gh <= 4) | |
b3b94faa | 1258 | break; |
eaf5bd3c SW |
1259 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1260 | if (!pph) | |
1261 | return -ENOMEM; | |
b3b94faa DT |
1262 | } |
1263 | ||
eaf5bd3c | 1264 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1265 | |
eaf5bd3c SW |
1266 | if (pph != tmp) |
1267 | kfree(pph); | |
b3b94faa DT |
1268 | |
1269 | return error; | |
1270 | } | |
1271 | ||
1272 | /** | |
1273 | * gfs2_glock_dq_m - release multiple glocks | |
1274 | * @num_gh: the number of structures | |
1275 | * @ghs: an array of struct gfs2_holder structures | |
1276 | * | |
1277 | */ | |
1278 | ||
1279 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1280 | { | |
1281 | unsigned int x; | |
1282 | ||
1283 | for (x = 0; x < num_gh; x++) | |
1284 | gfs2_glock_dq(&ghs[x]); | |
1285 | } | |
1286 | ||
1287 | /** | |
1288 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1289 | * @num_gh: the number of structures | |
1290 | * @ghs: an array of struct gfs2_holder structures | |
1291 | * | |
1292 | */ | |
1293 | ||
1294 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1295 | { | |
1296 | unsigned int x; | |
1297 | ||
1298 | for (x = 0; x < num_gh; x++) | |
1299 | gfs2_glock_dq_uninit(&ghs[x]); | |
1300 | } | |
1301 | ||
f057f6cd | 1302 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1303 | { |
c4f68a13 BM |
1304 | unsigned long delay = 0; |
1305 | unsigned long holdtime; | |
1306 | unsigned long now = jiffies; | |
b3b94faa | 1307 | |
f057f6cd | 1308 | gfs2_glock_hold(gl); |
c4f68a13 BM |
1309 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1310 | if (time_before(now, holdtime)) | |
1311 | delay = holdtime - now; | |
dff52574 SW |
1312 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
1313 | delay = gl->gl_ops->go_min_hold_time; | |
b3b94faa | 1314 | |
6802e340 | 1315 | spin_lock(&gl->gl_spin); |
97cc1025 | 1316 | handle_callback(gl, state, delay); |
6802e340 | 1317 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1318 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1319 | gfs2_glock_put(gl); | |
b3b94faa DT |
1320 | } |
1321 | ||
1322 | /** | |
f057f6cd SW |
1323 | * gfs2_glock_complete - Callback used by locking |
1324 | * @gl: Pointer to the glock | |
1325 | * @ret: The return value from the dlm | |
b3b94faa | 1326 | * |
b3b94faa DT |
1327 | */ |
1328 | ||
f057f6cd | 1329 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1330 | { |
f057f6cd | 1331 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
f057f6cd SW |
1332 | gl->gl_reply = ret; |
1333 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) { | |
1334 | struct gfs2_holder *gh; | |
1335 | spin_lock(&gl->gl_spin); | |
1336 | gh = find_first_waiter(gl); | |
1337 | if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) && | |
1338 | (gl->gl_target != LM_ST_UNLOCKED)) || | |
1339 | ((ret & ~LM_OUT_ST_MASK) != 0)) | |
1340 | set_bit(GLF_FROZEN, &gl->gl_flags); | |
1341 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 1342 | if (test_bit(GLF_FROZEN, &gl->gl_flags)) |
b3b94faa | 1343 | return; |
b3b94faa | 1344 | } |
f057f6cd SW |
1345 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1346 | gfs2_glock_hold(gl); | |
1347 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1348 | gfs2_glock_put(gl); | |
b3b94faa DT |
1349 | } |
1350 | ||
b3b94faa | 1351 | |
97cc1025 | 1352 | static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask) |
b3b94faa DT |
1353 | { |
1354 | struct gfs2_glock *gl; | |
97cc1025 SW |
1355 | int may_demote; |
1356 | int nr_skipped = 0; | |
97cc1025 | 1357 | LIST_HEAD(skipped); |
b3b94faa | 1358 | |
97cc1025 SW |
1359 | if (nr == 0) |
1360 | goto out; | |
b3b94faa | 1361 | |
97cc1025 SW |
1362 | if (!(gfp_mask & __GFP_FS)) |
1363 | return -1; | |
b3b94faa | 1364 | |
97cc1025 SW |
1365 | spin_lock(&lru_lock); |
1366 | while(nr && !list_empty(&lru_list)) { | |
1367 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1368 | list_del_init(&gl->gl_lru); | |
1369 | atomic_dec(&lru_count); | |
1370 | ||
1371 | /* Test for being demotable */ | |
1372 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1373 | gfs2_glock_hold(gl); | |
97cc1025 SW |
1374 | spin_unlock(&lru_lock); |
1375 | spin_lock(&gl->gl_spin); | |
1376 | may_demote = demote_ok(gl); | |
97cc1025 SW |
1377 | if (may_demote) { |
1378 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1379 | nr--; | |
97cc1025 | 1380 | } |
7e71c55e SW |
1381 | clear_bit(GLF_LOCK, &gl->gl_flags); |
1382 | smp_mb__after_clear_bit(); | |
2163b1e6 | 1383 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
b94a170e BM |
1384 | gfs2_glock_put_nolock(gl); |
1385 | spin_unlock(&gl->gl_spin); | |
97cc1025 | 1386 | spin_lock(&lru_lock); |
2163b1e6 | 1387 | continue; |
97cc1025 | 1388 | } |
2163b1e6 SW |
1389 | nr_skipped++; |
1390 | list_add(&gl->gl_lru, &skipped); | |
b3b94faa | 1391 | } |
97cc1025 SW |
1392 | list_splice(&skipped, &lru_list); |
1393 | atomic_add(nr_skipped, &lru_count); | |
1394 | spin_unlock(&lru_lock); | |
1395 | out: | |
1396 | return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure; | |
b3b94faa DT |
1397 | } |
1398 | ||
97cc1025 SW |
1399 | static struct shrinker glock_shrinker = { |
1400 | .shrink = gfs2_shrink_glock_memory, | |
1401 | .seeks = DEFAULT_SEEKS, | |
1402 | }; | |
1403 | ||
b3b94faa DT |
1404 | /** |
1405 | * examine_bucket - Call a function for glock in a hash bucket | |
1406 | * @examiner: the function | |
1407 | * @sdp: the filesystem | |
1408 | * @bucket: the bucket | |
1409 | * | |
1410 | * Returns: 1 if the bucket has entries | |
1411 | */ | |
1412 | ||
1413 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1414 | unsigned int hash) |
b3b94faa | 1415 | { |
24264434 SW |
1416 | struct gfs2_glock *gl, *prev = NULL; |
1417 | int has_entries = 0; | |
b6397893 | 1418 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1419 | |
24264434 | 1420 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1421 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1422 | if (hlist_empty(head)) | |
24264434 | 1423 | goto out; |
b6397893 SW |
1424 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1425 | while(1) { | |
8fbbfd21 | 1426 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1427 | gfs2_glock_hold(gl); |
24264434 SW |
1428 | read_unlock(gl_lock_addr(hash)); |
1429 | if (prev) | |
1430 | gfs2_glock_put(prev); | |
1431 | prev = gl; | |
1432 | examiner(gl); | |
a8336344 | 1433 | has_entries = 1; |
24264434 | 1434 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1435 | } |
b6397893 SW |
1436 | if (gl->gl_list.next == NULL) |
1437 | break; | |
24264434 | 1438 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1439 | } |
24264434 SW |
1440 | out: |
1441 | read_unlock(gl_lock_addr(hash)); | |
1442 | if (prev) | |
1443 | gfs2_glock_put(prev); | |
8fbbfd21 | 1444 | cond_resched(); |
24264434 | 1445 | return has_entries; |
b3b94faa DT |
1446 | } |
1447 | ||
f057f6cd SW |
1448 | |
1449 | /** | |
1450 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1451 | * @gl: The glock to thaw | |
1452 | * | |
1453 | * N.B. When we freeze a glock, we leave a ref to the glock outstanding, | |
1454 | * so this has to result in the ref count being dropped by one. | |
1455 | */ | |
1456 | ||
1457 | static void thaw_glock(struct gfs2_glock *gl) | |
1458 | { | |
1459 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1460 | return; | |
f057f6cd SW |
1461 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1462 | gfs2_glock_hold(gl); | |
1463 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1464 | gfs2_glock_put(gl); | |
f057f6cd SW |
1465 | } |
1466 | ||
b3b94faa DT |
1467 | /** |
1468 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1469 | * @gl: the glock to look at | |
1470 | * | |
1471 | */ | |
1472 | ||
1473 | static void clear_glock(struct gfs2_glock *gl) | |
1474 | { | |
97cc1025 SW |
1475 | spin_lock(&lru_lock); |
1476 | if (!list_empty(&gl->gl_lru)) { | |
1477 | list_del_init(&gl->gl_lru); | |
1478 | atomic_dec(&lru_count); | |
b3b94faa | 1479 | } |
97cc1025 | 1480 | spin_unlock(&lru_lock); |
b3b94faa | 1481 | |
6802e340 SW |
1482 | spin_lock(&gl->gl_spin); |
1483 | if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED) | |
97cc1025 | 1484 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
6802e340 SW |
1485 | spin_unlock(&gl->gl_spin); |
1486 | gfs2_glock_hold(gl); | |
1487 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1488 | gfs2_glock_put(gl); | |
b3b94faa DT |
1489 | } |
1490 | ||
f057f6cd SW |
1491 | /** |
1492 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1493 | * @sdp: The super block | |
1494 | * | |
1495 | */ | |
1496 | ||
1497 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1498 | { | |
1499 | unsigned x; | |
1500 | ||
1501 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1502 | examine_bucket(thaw_glock, sdp, x); | |
1503 | } | |
1504 | ||
b3b94faa DT |
1505 | /** |
1506 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1507 | * @sdp: the filesystem | |
1508 | * @wait: wait until it's all gone | |
1509 | * | |
1bdad606 | 1510 | * Called when unmounting the filesystem. |
b3b94faa DT |
1511 | */ |
1512 | ||
fefc03bf | 1513 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa DT |
1514 | { |
1515 | unsigned long t; | |
1516 | unsigned int x; | |
1517 | int cont; | |
1518 | ||
1519 | t = jiffies; | |
1520 | ||
1521 | for (;;) { | |
1522 | cont = 0; | |
24264434 | 1523 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1524 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1525 | cont = 1; |
24264434 | 1526 | } |
b3b94faa | 1527 | |
1bdad606 | 1528 | if (!cont) |
b3b94faa DT |
1529 | break; |
1530 | ||
1531 | if (time_after_eq(jiffies, | |
1532 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1533 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1534 | "Dumping lock state...\n"); | |
1535 | gfs2_dump_lockstate(sdp); | |
1536 | t = jiffies; | |
1537 | } | |
1538 | ||
61be084e | 1539 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1540 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1541 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1542 | msleep(10); |
b3b94faa | 1543 | } |
8f05228e SW |
1544 | flush_workqueue(glock_workqueue); |
1545 | wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0); | |
1546 | gfs2_dump_lockstate(sdp); | |
b3b94faa DT |
1547 | } |
1548 | ||
813e0c46 SW |
1549 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1550 | { | |
1551 | struct gfs2_glock *gl = ip->i_gl; | |
1552 | int ret; | |
1553 | ||
1554 | ret = gfs2_truncatei_resume(ip); | |
1555 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1556 | ||
1557 | spin_lock(&gl->gl_spin); | |
1558 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1559 | run_queue(gl, 1); | |
1560 | spin_unlock(&gl->gl_spin); | |
1561 | } | |
1562 | ||
6802e340 | 1563 | static const char *state2str(unsigned state) |
04b933f2 | 1564 | { |
6802e340 SW |
1565 | switch(state) { |
1566 | case LM_ST_UNLOCKED: | |
1567 | return "UN"; | |
1568 | case LM_ST_SHARED: | |
1569 | return "SH"; | |
1570 | case LM_ST_DEFERRED: | |
1571 | return "DF"; | |
1572 | case LM_ST_EXCLUSIVE: | |
1573 | return "EX"; | |
1574 | } | |
1575 | return "??"; | |
1576 | } | |
1577 | ||
1578 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1579 | { | |
1580 | char *p = buf; | |
1581 | if (flags & LM_FLAG_TRY) | |
1582 | *p++ = 't'; | |
1583 | if (flags & LM_FLAG_TRY_1CB) | |
1584 | *p++ = 'T'; | |
1585 | if (flags & LM_FLAG_NOEXP) | |
1586 | *p++ = 'e'; | |
1587 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1588 | *p++ = 'A'; |
6802e340 SW |
1589 | if (flags & LM_FLAG_PRIORITY) |
1590 | *p++ = 'p'; | |
1591 | if (flags & GL_ASYNC) | |
1592 | *p++ = 'a'; | |
1593 | if (flags & GL_EXACT) | |
1594 | *p++ = 'E'; | |
6802e340 SW |
1595 | if (flags & GL_NOCACHE) |
1596 | *p++ = 'c'; | |
1597 | if (test_bit(HIF_HOLDER, &iflags)) | |
1598 | *p++ = 'H'; | |
1599 | if (test_bit(HIF_WAIT, &iflags)) | |
1600 | *p++ = 'W'; | |
1601 | if (test_bit(HIF_FIRST, &iflags)) | |
1602 | *p++ = 'F'; | |
1603 | *p = 0; | |
1604 | return buf; | |
04b933f2 RP |
1605 | } |
1606 | ||
b3b94faa DT |
1607 | /** |
1608 | * dump_holder - print information about a glock holder | |
6802e340 | 1609 | * @seq: the seq_file struct |
b3b94faa DT |
1610 | * @gh: the glock holder |
1611 | * | |
1612 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1613 | */ | |
1614 | ||
6802e340 | 1615 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1616 | { |
6802e340 SW |
1617 | struct task_struct *gh_owner = NULL; |
1618 | char buffer[KSYM_SYMBOL_LEN]; | |
1619 | char flags_buf[32]; | |
b3b94faa | 1620 | |
6802e340 SW |
1621 | sprint_symbol(buffer, gh->gh_ip); |
1622 | if (gh->gh_owner_pid) | |
b1e058da | 1623 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
6802e340 SW |
1624 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", |
1625 | state2str(gh->gh_state), | |
1626 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1627 | gh->gh_error, | |
1628 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1629 | gh_owner ? gh_owner->comm : "(ended)", buffer); | |
7c52b166 | 1630 | return 0; |
b3b94faa DT |
1631 | } |
1632 | ||
6802e340 SW |
1633 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1634 | { | |
1635 | char *p = buf; | |
1636 | if (test_bit(GLF_LOCK, gflags)) | |
1637 | *p++ = 'l'; | |
6802e340 SW |
1638 | if (test_bit(GLF_DEMOTE, gflags)) |
1639 | *p++ = 'D'; | |
1640 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1641 | *p++ = 'd'; | |
1642 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1643 | *p++ = 'p'; | |
1644 | if (test_bit(GLF_DIRTY, gflags)) | |
1645 | *p++ = 'y'; | |
1646 | if (test_bit(GLF_LFLUSH, gflags)) | |
1647 | *p++ = 'f'; | |
1648 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1649 | *p++ = 'i'; | |
1650 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1651 | *p++ = 'r'; | |
f057f6cd | 1652 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1653 | *p++ = 'I'; |
f057f6cd SW |
1654 | if (test_bit(GLF_FROZEN, gflags)) |
1655 | *p++ = 'F'; | |
6802e340 SW |
1656 | *p = 0; |
1657 | return buf; | |
b3b94faa DT |
1658 | } |
1659 | ||
1660 | /** | |
6802e340 SW |
1661 | * __dump_glock - print information about a glock |
1662 | * @seq: The seq_file struct | |
b3b94faa | 1663 | * @gl: the glock |
6802e340 SW |
1664 | * |
1665 | * The file format is as follows: | |
1666 | * One line per object, capital letters are used to indicate objects | |
1667 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1668 | * other objects are indented by a single space and follow the glock to | |
1669 | * which they are related. Fields are indicated by lower case letters | |
1670 | * followed by a colon and the field value, except for strings which are in | |
1671 | * [] so that its possible to see if they are composed of spaces for | |
1672 | * example. The field's are n = number (id of the object), f = flags, | |
1673 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1674 | * |
1675 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1676 | */ | |
1677 | ||
6802e340 | 1678 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1679 | { |
6802e340 SW |
1680 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1681 | unsigned long long dtime; | |
1682 | const struct gfs2_holder *gh; | |
1683 | char gflags_buf[32]; | |
1684 | int error = 0; | |
b3b94faa | 1685 | |
6802e340 SW |
1686 | dtime = jiffies - gl->gl_demote_time; |
1687 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1688 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1689 | dtime = 0; | |
f057f6cd | 1690 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu a:%d r:%d\n", |
6802e340 SW |
1691 | state2str(gl->gl_state), |
1692 | gl->gl_name.ln_type, | |
1693 | (unsigned long long)gl->gl_name.ln_number, | |
1694 | gflags2str(gflags_buf, &gl->gl_flags), | |
1695 | state2str(gl->gl_target), | |
1696 | state2str(gl->gl_demote_state), dtime, | |
6802e340 SW |
1697 | atomic_read(&gl->gl_ail_count), |
1698 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1699 | |
b3b94faa | 1700 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1701 | error = dump_holder(seq, gh); |
b3b94faa DT |
1702 | if (error) |
1703 | goto out; | |
1704 | } | |
6802e340 SW |
1705 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1706 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1707 | out: |
b3b94faa DT |
1708 | return error; |
1709 | } | |
1710 | ||
6802e340 SW |
1711 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1712 | { | |
1713 | int ret; | |
1714 | spin_lock(&gl->gl_spin); | |
1715 | ret = __dump_glock(seq, gl); | |
1716 | spin_unlock(&gl->gl_spin); | |
1717 | return ret; | |
1718 | } | |
1719 | ||
b3b94faa DT |
1720 | /** |
1721 | * gfs2_dump_lockstate - print out the current lockstate | |
1722 | * @sdp: the filesystem | |
1723 | * @ub: the buffer to copy the information into | |
1724 | * | |
1725 | * If @ub is NULL, dump the lockstate to the console. | |
1726 | * | |
1727 | */ | |
1728 | ||
08bc2dbc | 1729 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1730 | { |
b3b94faa | 1731 | struct gfs2_glock *gl; |
b6397893 | 1732 | struct hlist_node *h; |
b3b94faa DT |
1733 | unsigned int x; |
1734 | int error = 0; | |
1735 | ||
1736 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1737 | |
087efdd3 | 1738 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1739 | |
b6397893 | 1740 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1741 | if (gl->gl_sbd != sdp) |
1742 | continue; | |
b3b94faa | 1743 | |
7c52b166 | 1744 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1745 | if (error) |
1746 | break; | |
1747 | } | |
1748 | ||
087efdd3 | 1749 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1750 | |
1751 | if (error) | |
1752 | break; | |
1753 | } | |
1754 | ||
1755 | ||
1756 | return error; | |
1757 | } | |
1758 | ||
8fbbfd21 | 1759 | |
85d1da67 SW |
1760 | int __init gfs2_glock_init(void) |
1761 | { | |
1762 | unsigned i; | |
1763 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1764 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1765 | } |
087efdd3 SW |
1766 | #ifdef GL_HASH_LOCK_SZ |
1767 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1768 | rwlock_init(&gl_hash_locks[i]); | |
1769 | } | |
1770 | #endif | |
8fbbfd21 | 1771 | |
c4f68a13 | 1772 | glock_workqueue = create_workqueue("glock_workqueue"); |
97cc1025 | 1773 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1774 | return PTR_ERR(glock_workqueue); |
b94a170e BM |
1775 | gfs2_delete_workqueue = create_workqueue("delete_workqueue"); |
1776 | if (IS_ERR(gfs2_delete_workqueue)) { | |
1777 | destroy_workqueue(glock_workqueue); | |
1778 | return PTR_ERR(gfs2_delete_workqueue); | |
1779 | } | |
97cc1025 SW |
1780 | |
1781 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1782 | |
85d1da67 SW |
1783 | return 0; |
1784 | } | |
1785 | ||
8fbbfd21 SW |
1786 | void gfs2_glock_exit(void) |
1787 | { | |
97cc1025 | 1788 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1789 | destroy_workqueue(glock_workqueue); |
b94a170e | 1790 | destroy_workqueue(gfs2_delete_workqueue); |
8fbbfd21 SW |
1791 | } |
1792 | ||
6802e340 | 1793 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1794 | { |
7b08fc62 SW |
1795 | struct gfs2_glock *gl; |
1796 | ||
a947e033 | 1797 | restart: |
7a0079d9 | 1798 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1799 | gl = gi->gl; |
1800 | if (gl) { | |
a947e033 AD |
1801 | gi->gl = hlist_entry(gl->gl_list.next, |
1802 | struct gfs2_glock, gl_list); | |
c1e817d0 SW |
1803 | } else { |
1804 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1805 | struct gfs2_glock, gl_list); | |
7c52b166 | 1806 | } |
c1e817d0 SW |
1807 | if (gi->gl) |
1808 | gfs2_glock_hold(gi->gl); | |
7a0079d9 | 1809 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1810 | if (gl) |
1811 | gfs2_glock_put(gl); | |
6802e340 | 1812 | while (gi->gl == NULL) { |
c1e817d0 | 1813 | gi->hash++; |
7b08fc62 SW |
1814 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
1815 | return 1; | |
1816 | read_lock(gl_lock_addr(gi->hash)); | |
1817 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1818 | struct gfs2_glock, gl_list); | |
1819 | if (gi->gl) | |
1820 | gfs2_glock_hold(gi->gl); | |
1821 | read_unlock(gl_lock_addr(gi->hash)); | |
1822 | } | |
a947e033 AD |
1823 | |
1824 | if (gi->sdp != gi->gl->gl_sbd) | |
1825 | goto restart; | |
1826 | ||
7c52b166 RP |
1827 | return 0; |
1828 | } | |
1829 | ||
6802e340 | 1830 | static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) |
7c52b166 | 1831 | { |
7b08fc62 SW |
1832 | if (gi->gl) |
1833 | gfs2_glock_put(gi->gl); | |
a947e033 | 1834 | gi->gl = NULL; |
7c52b166 RP |
1835 | } |
1836 | ||
6802e340 | 1837 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1838 | { |
6802e340 | 1839 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1840 | loff_t n = *pos; |
1841 | ||
6802e340 | 1842 | gi->hash = 0; |
7c52b166 | 1843 | |
6802e340 | 1844 | do { |
7c52b166 RP |
1845 | if (gfs2_glock_iter_next(gi)) { |
1846 | gfs2_glock_iter_free(gi); | |
1847 | return NULL; | |
1848 | } | |
6802e340 | 1849 | } while (n--); |
7c52b166 | 1850 | |
6802e340 | 1851 | return gi->gl; |
7c52b166 RP |
1852 | } |
1853 | ||
6802e340 | 1854 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1855 | loff_t *pos) |
1856 | { | |
6802e340 | 1857 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1858 | |
1859 | (*pos)++; | |
1860 | ||
1861 | if (gfs2_glock_iter_next(gi)) { | |
1862 | gfs2_glock_iter_free(gi); | |
1863 | return NULL; | |
1864 | } | |
1865 | ||
6802e340 | 1866 | return gi->gl; |
7c52b166 RP |
1867 | } |
1868 | ||
6802e340 | 1869 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1870 | { |
6802e340 SW |
1871 | struct gfs2_glock_iter *gi = seq->private; |
1872 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
1873 | } |
1874 | ||
6802e340 | 1875 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1876 | { |
6802e340 | 1877 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1878 | } |
1879 | ||
4ef29002 | 1880 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1881 | .start = gfs2_glock_seq_start, |
1882 | .next = gfs2_glock_seq_next, | |
1883 | .stop = gfs2_glock_seq_stop, | |
1884 | .show = gfs2_glock_seq_show, | |
1885 | }; | |
1886 | ||
1887 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1888 | { | |
6802e340 SW |
1889 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1890 | sizeof(struct gfs2_glock_iter)); | |
1891 | if (ret == 0) { | |
1892 | struct seq_file *seq = file->private_data; | |
1893 | struct gfs2_glock_iter *gi = seq->private; | |
1894 | gi->sdp = inode->i_private; | |
1895 | } | |
1896 | return ret; | |
7c52b166 RP |
1897 | } |
1898 | ||
1899 | static const struct file_operations gfs2_debug_fops = { | |
1900 | .owner = THIS_MODULE, | |
1901 | .open = gfs2_debugfs_open, | |
1902 | .read = seq_read, | |
1903 | .llseek = seq_lseek, | |
6802e340 | 1904 | .release = seq_release_private, |
7c52b166 RP |
1905 | }; |
1906 | ||
1907 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1908 | { | |
5f882096 RP |
1909 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1910 | if (!sdp->debugfs_dir) | |
1911 | return -ENOMEM; | |
1912 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1913 | S_IFREG | S_IRUGO, | |
1914 | sdp->debugfs_dir, sdp, | |
1915 | &gfs2_debug_fops); | |
1916 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1917 | return -ENOMEM; |
1918 | ||
1919 | return 0; | |
1920 | } | |
1921 | ||
1922 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1923 | { | |
5f882096 RP |
1924 | if (sdp && sdp->debugfs_dir) { |
1925 | if (sdp->debugfs_dentry_glocks) { | |
1926 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1927 | sdp->debugfs_dentry_glocks = NULL; | |
1928 | } | |
1929 | debugfs_remove(sdp->debugfs_dir); | |
1930 | sdp->debugfs_dir = NULL; | |
1931 | } | |
7c52b166 RP |
1932 | } |
1933 | ||
1934 | int gfs2_register_debugfs(void) | |
1935 | { | |
1936 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1937 | return gfs2_root ? 0 : -ENOMEM; | |
1938 | } | |
1939 | ||
1940 | void gfs2_unregister_debugfs(void) | |
1941 | { | |
1942 | debugfs_remove(gfs2_root); | |
5f882096 | 1943 | gfs2_root = NULL; |
7c52b166 | 1944 | } |