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> | |
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" |
b3b94faa | 42 | |
37b2fa6a | 43 | struct gfs2_gl_hash_bucket { |
b6397893 | 44 | struct hlist_head hb_list; |
37b2fa6a SW |
45 | }; |
46 | ||
6802e340 SW |
47 | struct gfs2_glock_iter { |
48 | int hash; /* hash bucket index */ | |
49 | struct gfs2_sbd *sdp; /* incore superblock */ | |
50 | struct gfs2_glock *gl; /* current glock struct */ | |
51 | char string[512]; /* scratch space */ | |
7c52b166 RP |
52 | }; |
53 | ||
b3b94faa DT |
54 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
55 | ||
08bc2dbc | 56 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); |
6802e340 SW |
57 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); |
58 | #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0) | |
59 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); | |
c4f68a13 | 60 | |
61be084e | 61 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
7c52b166 | 62 | static struct dentry *gfs2_root; |
c4f68a13 | 63 | static struct workqueue_struct *glock_workqueue; |
97cc1025 SW |
64 | static LIST_HEAD(lru_list); |
65 | static atomic_t lru_count = ATOMIC_INIT(0); | |
eb8374e7 | 66 | static DEFINE_SPINLOCK(lru_lock); |
08bc2dbc | 67 | |
b6397893 | 68 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
69 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
70 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
71 | ||
85d1da67 | 72 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 73 | static struct dentry *gfs2_root; |
087efdd3 SW |
74 | |
75 | /* | |
76 | * Despite what you might think, the numbers below are not arbitrary :-) | |
77 | * They are taken from the ipv4 routing hash code, which is well tested | |
78 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
79 | * but for now this should be fine. | |
80 | * | |
81 | * The reason for putting the locks in a separate array from the list heads | |
82 | * is that we can have fewer locks than list heads and save memory. We use | |
83 | * the same hash function for both, but with a different hash mask. | |
84 | */ | |
85 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
86 | defined(CONFIG_PROVE_LOCKING) | |
87 | ||
88 | #ifdef CONFIG_LOCKDEP | |
89 | # define GL_HASH_LOCK_SZ 256 | |
90 | #else | |
91 | # if NR_CPUS >= 32 | |
92 | # define GL_HASH_LOCK_SZ 4096 | |
93 | # elif NR_CPUS >= 16 | |
94 | # define GL_HASH_LOCK_SZ 2048 | |
95 | # elif NR_CPUS >= 8 | |
96 | # define GL_HASH_LOCK_SZ 1024 | |
97 | # elif NR_CPUS >= 4 | |
98 | # define GL_HASH_LOCK_SZ 512 | |
99 | # else | |
100 | # define GL_HASH_LOCK_SZ 256 | |
101 | # endif | |
102 | #endif | |
103 | ||
104 | /* We never want more locks than chains */ | |
105 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
106 | # undef GL_HASH_LOCK_SZ | |
107 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
108 | #endif | |
109 | ||
110 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
111 | ||
112 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
113 | { | |
94610610 | 114 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
115 | } |
116 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 117 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
118 | { |
119 | return NULL; | |
120 | } | |
121 | #endif | |
85d1da67 | 122 | |
b3b94faa DT |
123 | /** |
124 | * gl_hash() - Turn glock number into hash bucket number | |
125 | * @lock: The glock number | |
126 | * | |
127 | * Returns: The number of the corresponding hash bucket | |
128 | */ | |
129 | ||
b8547856 SW |
130 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
131 | const struct lm_lockname *name) | |
b3b94faa DT |
132 | { |
133 | unsigned int h; | |
134 | ||
cd915493 | 135 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 136 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 137 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
138 | h &= GFS2_GL_HASH_MASK; |
139 | ||
140 | return h; | |
141 | } | |
142 | ||
143 | /** | |
144 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
145 | * @gl: The glock to release | |
146 | * | |
147 | * Also calls lock module to release its internal structure for this glock. | |
148 | * | |
149 | */ | |
150 | ||
151 | static void glock_free(struct gfs2_glock *gl) | |
152 | { | |
153 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
154 | struct inode *aspace = gl->gl_aspace; | |
155 | ||
b3b94faa DT |
156 | if (aspace) |
157 | gfs2_aspace_put(aspace); | |
158 | ||
f057f6cd | 159 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gfs2_glock_cachep, gl); |
b3b94faa DT |
160 | } |
161 | ||
162 | /** | |
163 | * gfs2_glock_hold() - increment reference count on glock | |
164 | * @gl: The glock to hold | |
165 | * | |
166 | */ | |
167 | ||
048786f1 | 168 | static void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 169 | { |
d8348de0 | 170 | GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
16feb9fe | 171 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
172 | } |
173 | ||
97cc1025 SW |
174 | /** |
175 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
176 | * @gl: the glock | |
177 | * | |
178 | */ | |
179 | ||
180 | static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
181 | { | |
182 | spin_lock(&lru_lock); | |
183 | if (list_empty(&gl->gl_lru) && gl->gl_state != LM_ST_UNLOCKED) { | |
184 | list_add_tail(&gl->gl_lru, &lru_list); | |
185 | atomic_inc(&lru_count); | |
186 | } | |
187 | spin_unlock(&lru_lock); | |
188 | } | |
189 | ||
b3b94faa DT |
190 | /** |
191 | * gfs2_glock_put() - Decrement reference count on glock | |
192 | * @gl: The glock to put | |
193 | * | |
194 | */ | |
195 | ||
196 | int gfs2_glock_put(struct gfs2_glock *gl) | |
197 | { | |
b3b94faa DT |
198 | int rv = 0; |
199 | ||
087efdd3 | 200 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 201 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 202 | hlist_del(&gl->gl_list); |
087efdd3 | 203 | write_unlock(gl_lock_addr(gl->gl_hash)); |
97cc1025 SW |
204 | spin_lock(&lru_lock); |
205 | if (!list_empty(&gl->gl_lru)) { | |
206 | list_del_init(&gl->gl_lru); | |
207 | atomic_dec(&lru_count); | |
208 | } | |
209 | spin_unlock(&lru_lock); | |
6802e340 | 210 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
b3b94faa DT |
211 | glock_free(gl); |
212 | rv = 1; | |
213 | goto out; | |
214 | } | |
97cc1025 SW |
215 | /* 1 for being hashed, 1 for having state != LM_ST_UNLOCKED */ |
216 | if (atomic_read(&gl->gl_ref) == 2) | |
217 | gfs2_glock_schedule_for_reclaim(gl); | |
d8348de0 | 218 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 219 | out: |
b3b94faa DT |
220 | return rv; |
221 | } | |
222 | ||
b3b94faa DT |
223 | /** |
224 | * search_bucket() - Find struct gfs2_glock by lock number | |
225 | * @bucket: the bucket to search | |
226 | * @name: The lock name | |
227 | * | |
228 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
229 | */ | |
230 | ||
37b2fa6a | 231 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 232 | const struct gfs2_sbd *sdp, |
d6a53727 | 233 | const struct lm_lockname *name) |
b3b94faa DT |
234 | { |
235 | struct gfs2_glock *gl; | |
b6397893 | 236 | struct hlist_node *h; |
b3b94faa | 237 | |
b6397893 | 238 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
239 | if (!lm_name_equal(&gl->gl_name, name)) |
240 | continue; | |
899be4d3 SW |
241 | if (gl->gl_sbd != sdp) |
242 | continue; | |
b3b94faa | 243 | |
16feb9fe | 244 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
245 | |
246 | return gl; | |
247 | } | |
248 | ||
249 | return NULL; | |
250 | } | |
251 | ||
6802e340 SW |
252 | /** |
253 | * may_grant - check if its ok to grant a new lock | |
254 | * @gl: The glock | |
255 | * @gh: The lock request which we wish to grant | |
256 | * | |
257 | * Returns: true if its ok to grant the lock | |
258 | */ | |
259 | ||
260 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
261 | { | |
262 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
263 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
264 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
265 | return 0; | |
266 | if (gl->gl_state == gh->gh_state) | |
267 | return 1; | |
268 | if (gh->gh_flags & GL_EXACT) | |
269 | return 0; | |
209806ab SW |
270 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
271 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
272 | return 1; | |
273 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
274 | return 1; | |
275 | } | |
6802e340 SW |
276 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
277 | return 1; | |
278 | return 0; | |
279 | } | |
280 | ||
281 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
282 | { | |
283 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
284 | smp_mb__after_clear_bit(); | |
285 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
286 | } | |
287 | ||
288 | /** | |
289 | * do_promote - promote as many requests as possible on the current queue | |
290 | * @gl: The glock | |
291 | * | |
813e0c46 SW |
292 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
293 | * if a type specific operation is underway. | |
6802e340 SW |
294 | */ |
295 | ||
296 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
297 | __releases(&gl->gl_spin) |
298 | __acquires(&gl->gl_spin) | |
6802e340 SW |
299 | { |
300 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
301 | struct gfs2_holder *gh, *tmp; | |
302 | int ret; | |
303 | ||
304 | restart: | |
305 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
306 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
307 | continue; | |
308 | if (may_grant(gl, gh)) { | |
309 | if (gh->gh_list.prev == &gl->gl_holders && | |
310 | glops->go_lock) { | |
311 | spin_unlock(&gl->gl_spin); | |
312 | /* FIXME: eliminate this eventually */ | |
313 | ret = glops->go_lock(gh); | |
314 | spin_lock(&gl->gl_spin); | |
315 | if (ret) { | |
813e0c46 SW |
316 | if (ret == 1) |
317 | return 2; | |
6802e340 SW |
318 | gh->gh_error = ret; |
319 | list_del_init(&gh->gh_list); | |
320 | gfs2_holder_wake(gh); | |
321 | goto restart; | |
322 | } | |
323 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
324 | gfs2_holder_wake(gh); | |
325 | goto restart; | |
326 | } | |
327 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
328 | gfs2_holder_wake(gh); | |
329 | continue; | |
330 | } | |
331 | if (gh->gh_list.prev == &gl->gl_holders) | |
332 | return 1; | |
333 | break; | |
334 | } | |
335 | return 0; | |
336 | } | |
337 | ||
338 | /** | |
339 | * do_error - Something unexpected has happened during a lock request | |
340 | * | |
341 | */ | |
342 | ||
343 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
344 | { | |
345 | struct gfs2_holder *gh, *tmp; | |
346 | ||
347 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
348 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
349 | continue; | |
350 | if (ret & LM_OUT_ERROR) | |
351 | gh->gh_error = -EIO; | |
352 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
353 | gh->gh_error = GLR_TRYFAILED; | |
354 | else | |
355 | continue; | |
356 | list_del_init(&gh->gh_list); | |
357 | gfs2_holder_wake(gh); | |
358 | } | |
359 | } | |
360 | ||
361 | /** | |
362 | * find_first_waiter - find the first gh that's waiting for the glock | |
363 | * @gl: the glock | |
364 | */ | |
365 | ||
366 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
367 | { | |
368 | struct gfs2_holder *gh; | |
369 | ||
370 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
371 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
372 | return gh; | |
373 | } | |
374 | return NULL; | |
375 | } | |
376 | ||
377 | /** | |
378 | * state_change - record that the glock is now in a different state | |
379 | * @gl: the glock | |
380 | * @new_state the new state | |
381 | * | |
382 | */ | |
383 | ||
384 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
385 | { | |
386 | int held1, held2; | |
387 | ||
388 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
389 | held2 = (new_state != LM_ST_UNLOCKED); | |
390 | ||
391 | if (held1 != held2) { | |
392 | if (held2) | |
393 | gfs2_glock_hold(gl); | |
394 | else | |
395 | gfs2_glock_put(gl); | |
396 | } | |
397 | ||
398 | gl->gl_state = new_state; | |
399 | gl->gl_tchange = jiffies; | |
400 | } | |
401 | ||
402 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
403 | { | |
404 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
405 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
406 | smp_mb__after_clear_bit(); | |
407 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
408 | } | |
409 | ||
410 | /** | |
411 | * finish_xmote - The DLM has replied to one of our lock requests | |
412 | * @gl: The glock | |
413 | * @ret: The status from the DLM | |
414 | * | |
415 | */ | |
416 | ||
417 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
418 | { | |
419 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
420 | struct gfs2_holder *gh; | |
421 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 422 | int rv; |
6802e340 SW |
423 | |
424 | spin_lock(&gl->gl_spin); | |
425 | state_change(gl, state); | |
426 | gh = find_first_waiter(gl); | |
427 | ||
428 | /* Demote to UN request arrived during demote to SH or DF */ | |
429 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
430 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
431 | gl->gl_target = LM_ST_UNLOCKED; | |
432 | ||
433 | /* Check for state != intended state */ | |
434 | if (unlikely(state != gl->gl_target)) { | |
435 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
436 | /* move to back of queue and try next entry */ | |
437 | if (ret & LM_OUT_CANCELED) { | |
438 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
439 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
440 | gh = find_first_waiter(gl); | |
441 | gl->gl_target = gh->gh_state; | |
442 | goto retry; | |
443 | } | |
444 | /* Some error or failed "try lock" - report it */ | |
445 | if ((ret & LM_OUT_ERROR) || | |
446 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
447 | gl->gl_target = gl->gl_state; | |
448 | do_error(gl, ret); | |
449 | goto out; | |
450 | } | |
451 | } | |
452 | switch(state) { | |
453 | /* Unlocked due to conversion deadlock, try again */ | |
454 | case LM_ST_UNLOCKED: | |
455 | retry: | |
456 | do_xmote(gl, gh, gl->gl_target); | |
457 | break; | |
458 | /* Conversion fails, unlock and try again */ | |
459 | case LM_ST_SHARED: | |
460 | case LM_ST_DEFERRED: | |
461 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
462 | break; | |
463 | default: /* Everything else */ | |
464 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
465 | GLOCK_BUG_ON(gl, 1); | |
466 | } | |
467 | spin_unlock(&gl->gl_spin); | |
468 | gfs2_glock_put(gl); | |
469 | return; | |
470 | } | |
471 | ||
472 | /* Fast path - we got what we asked for */ | |
473 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
474 | gfs2_demote_wake(gl); | |
475 | if (state != LM_ST_UNLOCKED) { | |
476 | if (glops->go_xmote_bh) { | |
6802e340 SW |
477 | spin_unlock(&gl->gl_spin); |
478 | rv = glops->go_xmote_bh(gl, gh); | |
479 | if (rv == -EAGAIN) | |
480 | return; | |
481 | spin_lock(&gl->gl_spin); | |
482 | if (rv) { | |
483 | do_error(gl, rv); | |
484 | goto out; | |
485 | } | |
486 | } | |
813e0c46 SW |
487 | rv = do_promote(gl); |
488 | if (rv == 2) | |
489 | goto out_locked; | |
6802e340 SW |
490 | } |
491 | out: | |
492 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 493 | out_locked: |
6802e340 SW |
494 | spin_unlock(&gl->gl_spin); |
495 | gfs2_glock_put(gl); | |
496 | } | |
497 | ||
498 | static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, | |
f057f6cd | 499 | unsigned int req_state, |
6802e340 SW |
500 | unsigned int flags) |
501 | { | |
502 | int ret = LM_OUT_ERROR; | |
048bca22 SW |
503 | |
504 | if (!sdp->sd_lockstruct.ls_ops->lm_lock) | |
505 | return req_state == LM_ST_UNLOCKED ? 0 : req_state; | |
506 | ||
6802e340 | 507 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
f057f6cd | 508 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, |
6802e340 SW |
509 | req_state, flags); |
510 | return ret; | |
511 | } | |
512 | ||
513 | /** | |
514 | * do_xmote - Calls the DLM to change the state of a lock | |
515 | * @gl: The lock state | |
516 | * @gh: The holder (only for promotes) | |
517 | * @target: The target lock state | |
518 | * | |
519 | */ | |
520 | ||
521 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
522 | __releases(&gl->gl_spin) |
523 | __acquires(&gl->gl_spin) | |
6802e340 SW |
524 | { |
525 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
526 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
527 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
528 | int ret; | |
529 | ||
530 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
531 | LM_FLAG_PRIORITY); | |
532 | BUG_ON(gl->gl_state == target); | |
533 | BUG_ON(gl->gl_state == gl->gl_target); | |
534 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
535 | glops->go_inval) { | |
536 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
537 | do_error(gl, 0); /* Fail queued try locks */ | |
538 | } | |
539 | spin_unlock(&gl->gl_spin); | |
540 | if (glops->go_xmote_th) | |
541 | glops->go_xmote_th(gl); | |
542 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
543 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
544 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
545 | ||
546 | gfs2_glock_hold(gl); | |
547 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
548 | gl->gl_state == LM_ST_DEFERRED) && | |
549 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
550 | lck_flags |= LM_FLAG_TRY_1CB; | |
f057f6cd | 551 | ret = gfs2_lm_lock(sdp, gl, target, lck_flags); |
6802e340 SW |
552 | |
553 | if (!(ret & LM_OUT_ASYNC)) { | |
554 | finish_xmote(gl, ret); | |
555 | gfs2_glock_hold(gl); | |
556 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
557 | gfs2_glock_put(gl); | |
558 | } else { | |
559 | GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); | |
560 | } | |
561 | spin_lock(&gl->gl_spin); | |
562 | } | |
563 | ||
564 | /** | |
565 | * find_first_holder - find the first "holder" gh | |
566 | * @gl: the glock | |
567 | */ | |
568 | ||
569 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
570 | { | |
571 | struct gfs2_holder *gh; | |
572 | ||
573 | if (!list_empty(&gl->gl_holders)) { | |
574 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
575 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
576 | return gh; | |
577 | } | |
578 | return NULL; | |
579 | } | |
580 | ||
581 | /** | |
582 | * run_queue - do all outstanding tasks related to a glock | |
583 | * @gl: The glock in question | |
584 | * @nonblock: True if we must not block in run_queue | |
585 | * | |
586 | */ | |
587 | ||
588 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
589 | __releases(&gl->gl_spin) |
590 | __acquires(&gl->gl_spin) | |
6802e340 SW |
591 | { |
592 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 593 | int ret; |
6802e340 SW |
594 | |
595 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
596 | return; | |
597 | ||
598 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
599 | ||
600 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
601 | gl->gl_demote_state != gl->gl_state) { | |
602 | if (find_first_holder(gl)) | |
d8348de0 | 603 | goto out_unlock; |
6802e340 SW |
604 | if (nonblock) |
605 | goto out_sched; | |
606 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 607 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
608 | gl->gl_target = gl->gl_demote_state; |
609 | } else { | |
610 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
611 | gfs2_demote_wake(gl); | |
813e0c46 SW |
612 | ret = do_promote(gl); |
613 | if (ret == 0) | |
d8348de0 | 614 | goto out_unlock; |
813e0c46 | 615 | if (ret == 2) |
a228df63 | 616 | goto out; |
6802e340 SW |
617 | gh = find_first_waiter(gl); |
618 | gl->gl_target = gh->gh_state; | |
619 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
620 | do_error(gl, 0); /* Fail queued try locks */ | |
621 | } | |
622 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 623 | out: |
6802e340 SW |
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); | |
d8348de0 | 630 | out_unlock: |
6802e340 | 631 | clear_bit(GLF_LOCK, &gl->gl_flags); |
a228df63 | 632 | goto out; |
6802e340 SW |
633 | } |
634 | ||
c4f68a13 BM |
635 | static void glock_work_func(struct work_struct *work) |
636 | { | |
6802e340 | 637 | unsigned long delay = 0; |
c4f68a13 BM |
638 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
639 | ||
6802e340 SW |
640 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
641 | finish_xmote(gl, gl->gl_reply); | |
a228df63 | 642 | down_read(&gfs2_umount_flush_sem); |
c4f68a13 | 643 | spin_lock(&gl->gl_spin); |
265d529c SW |
644 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
645 | gl->gl_state != LM_ST_UNLOCKED && | |
646 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
647 | unsigned long holdtime, now = jiffies; |
648 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
649 | if (time_before(now, holdtime)) | |
650 | delay = holdtime - now; | |
651 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
652 | } | |
653 | run_queue(gl, 0); | |
c4f68a13 | 654 | spin_unlock(&gl->gl_spin); |
a228df63 | 655 | up_read(&gfs2_umount_flush_sem); |
6802e340 SW |
656 | if (!delay || |
657 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
658 | gfs2_glock_put(gl); | |
c4f68a13 BM |
659 | } |
660 | ||
b3b94faa DT |
661 | /** |
662 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
663 | * @sdp: The GFS2 superblock | |
664 | * @number: the lock number | |
665 | * @glops: The glock_operations to use | |
666 | * @create: If 0, don't create the glock if it doesn't exist | |
667 | * @glp: the glock is returned here | |
668 | * | |
669 | * This does not lock a glock, just finds/creates structures for one. | |
670 | * | |
671 | * Returns: errno | |
672 | */ | |
673 | ||
cd915493 | 674 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 675 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
676 | struct gfs2_glock **glp) |
677 | { | |
37b2fa6a | 678 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 679 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 680 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
681 | int error; |
682 | ||
087efdd3 | 683 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 684 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 685 | read_unlock(gl_lock_addr(hash)); |
b3b94faa | 686 | |
64d576ba SW |
687 | *glp = gl; |
688 | if (gl) | |
b3b94faa | 689 | return 0; |
64d576ba SW |
690 | if (!create) |
691 | return -ENOENT; | |
b3b94faa DT |
692 | |
693 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
694 | if (!gl) | |
695 | return -ENOMEM; | |
696 | ||
ec45d9f5 | 697 | gl->gl_flags = 0; |
b3b94faa | 698 | gl->gl_name = name; |
16feb9fe | 699 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 700 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 701 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 702 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 703 | gl->gl_hash = hash; |
b3b94faa | 704 | gl->gl_ops = glops; |
f057f6cd SW |
705 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
706 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
707 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 708 | gl->gl_tchange = jiffies; |
ec45d9f5 | 709 | gl->gl_object = NULL; |
b3b94faa | 710 | gl->gl_sbd = sdp; |
ec45d9f5 | 711 | gl->gl_aspace = NULL; |
c4f68a13 | 712 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b3b94faa DT |
713 | |
714 | /* If this glock protects actual on-disk data or metadata blocks, | |
715 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 716 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
717 | gl->gl_aspace = gfs2_aspace_get(sdp); |
718 | if (!gl->gl_aspace) { | |
719 | error = -ENOMEM; | |
720 | goto fail; | |
721 | } | |
722 | } | |
723 | ||
087efdd3 | 724 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 725 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 726 | if (tmp) { |
087efdd3 | 727 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
728 | glock_free(gl); |
729 | gl = tmp; | |
730 | } else { | |
b6397893 | 731 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 732 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
733 | } |
734 | ||
735 | *glp = gl; | |
736 | ||
737 | return 0; | |
738 | ||
ec45d9f5 | 739 | fail: |
907b9bce | 740 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
741 | return error; |
742 | } | |
743 | ||
744 | /** | |
745 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
746 | * @gl: the glock | |
747 | * @state: the state we're requesting | |
748 | * @flags: the modifier flags | |
749 | * @gh: the holder structure | |
750 | * | |
751 | */ | |
752 | ||
190562bd | 753 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
754 | struct gfs2_holder *gh) |
755 | { | |
756 | INIT_LIST_HEAD(&gh->gh_list); | |
757 | gh->gh_gl = gl; | |
d0dc80db | 758 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 759 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
760 | gh->gh_state = state; |
761 | gh->gh_flags = flags; | |
762 | gh->gh_error = 0; | |
763 | gh->gh_iflags = 0; | |
b3b94faa DT |
764 | gfs2_glock_hold(gl); |
765 | } | |
766 | ||
767 | /** | |
768 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
769 | * @state: the state we're requesting | |
770 | * @flags: the modifier flags | |
771 | * @gh: the holder structure | |
772 | * | |
773 | * Don't mess with the glock. | |
774 | * | |
775 | */ | |
776 | ||
190562bd | 777 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
778 | { |
779 | gh->gh_state = state; | |
579b78a4 | 780 | gh->gh_flags = flags; |
3b8249f6 | 781 | gh->gh_iflags = 0; |
d0dc80db | 782 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
783 | } |
784 | ||
785 | /** | |
786 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
787 | * @gh: the holder structure | |
788 | * | |
789 | */ | |
790 | ||
791 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
792 | { | |
b1e058da | 793 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
794 | gfs2_glock_put(gh->gh_gl); |
795 | gh->gh_gl = NULL; | |
d0dc80db | 796 | gh->gh_ip = 0; |
b3b94faa DT |
797 | } |
798 | ||
d93cfa98 | 799 | static int just_schedule(void *word) |
fee852e3 SW |
800 | { |
801 | schedule(); | |
802 | return 0; | |
803 | } | |
804 | ||
6802e340 | 805 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 806 | { |
6802e340 SW |
807 | might_sleep(); |
808 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE); | |
da755fdb SW |
809 | } |
810 | ||
6802e340 | 811 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 812 | { |
6802e340 SW |
813 | might_sleep(); |
814 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE); | |
b3b94faa DT |
815 | } |
816 | ||
817 | /** | |
6802e340 SW |
818 | * handle_callback - process a demote request |
819 | * @gl: the glock | |
820 | * @state: the state the caller wants us to change to | |
b3b94faa | 821 | * |
6802e340 SW |
822 | * There are only two requests that we are going to see in actual |
823 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
824 | */ |
825 | ||
6802e340 | 826 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 827 | unsigned long delay) |
b3b94faa | 828 | { |
6802e340 | 829 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 830 | |
6802e340 SW |
831 | set_bit(bit, &gl->gl_flags); |
832 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
833 | gl->gl_demote_state = state; | |
834 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
835 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
836 | gl->gl_demote_state != state) { | |
837 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 838 | } |
b3b94faa DT |
839 | } |
840 | ||
841 | /** | |
6802e340 | 842 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
843 | * @gh: the glock holder |
844 | * | |
845 | * Returns: 0 on success | |
846 | */ | |
847 | ||
6802e340 | 848 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 849 | { |
fee852e3 | 850 | wait_on_holder(gh); |
b3b94faa DT |
851 | return gh->gh_error; |
852 | } | |
853 | ||
6802e340 | 854 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 RP |
855 | { |
856 | va_list args; | |
857 | ||
858 | va_start(args, fmt); | |
6802e340 SW |
859 | if (seq) { |
860 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 861 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
862 | seq_printf(seq, gi->string); |
863 | } else { | |
864 | printk(KERN_ERR " "); | |
7c52b166 | 865 | vprintk(fmt, args); |
6802e340 | 866 | } |
7c52b166 RP |
867 | va_end(args); |
868 | } | |
869 | ||
b3b94faa DT |
870 | /** |
871 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
872 | * @gh: the holder structure to add | |
873 | * | |
6802e340 SW |
874 | * Eventually we should move the recursive locking trap to a |
875 | * debugging option or something like that. This is the fast | |
876 | * path and needs to have the minimum number of distractions. | |
877 | * | |
b3b94faa DT |
878 | */ |
879 | ||
6802e340 | 880 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
881 | __releases(&gl->gl_spin) |
882 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
883 | { |
884 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
885 | struct gfs2_sbd *sdp = gl->gl_sbd; |
886 | struct list_head *insert_pt = NULL; | |
887 | struct gfs2_holder *gh2; | |
888 | int try_lock = 0; | |
b3b94faa | 889 | |
b1e058da | 890 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
891 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
892 | BUG(); | |
190562bd | 893 | |
6802e340 SW |
894 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
895 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
896 | try_lock = 1; | |
897 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
898 | goto fail; | |
899 | } | |
900 | ||
901 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
902 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
903 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
904 | goto trap_recursive; | |
905 | if (try_lock && | |
906 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
907 | !may_grant(gl, gh)) { | |
908 | fail: | |
909 | gh->gh_error = GLR_TRYFAILED; | |
910 | gfs2_holder_wake(gh); | |
911 | return; | |
b4c20166 | 912 | } |
6802e340 SW |
913 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
914 | continue; | |
915 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
916 | insert_pt = &gh2->gh_list; | |
917 | } | |
918 | if (likely(insert_pt == NULL)) { | |
919 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
920 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
921 | goto do_cancel; | |
922 | return; | |
923 | } | |
924 | list_add_tail(&gh->gh_list, insert_pt); | |
925 | do_cancel: | |
926 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
927 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
928 | spin_unlock(&gl->gl_spin); | |
048bca22 | 929 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 930 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 931 | spin_lock(&gl->gl_spin); |
b3b94faa | 932 | } |
6802e340 | 933 | return; |
b3b94faa | 934 | |
6802e340 SW |
935 | trap_recursive: |
936 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
937 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
938 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
939 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
940 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
941 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
942 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
943 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
944 | __dump_glock(NULL, gl); | |
945 | BUG(); | |
b3b94faa DT |
946 | } |
947 | ||
948 | /** | |
949 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
950 | * @gh: the holder structure | |
951 | * | |
952 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
953 | * | |
954 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
955 | */ | |
956 | ||
957 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
958 | { | |
959 | struct gfs2_glock *gl = gh->gh_gl; | |
960 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
961 | int error = 0; | |
962 | ||
6802e340 | 963 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 964 | return -EIO; |
b3b94faa | 965 | |
b3b94faa DT |
966 | spin_lock(&gl->gl_spin); |
967 | add_to_queue(gh); | |
6802e340 | 968 | run_queue(gl, 1); |
b3b94faa DT |
969 | spin_unlock(&gl->gl_spin); |
970 | ||
6802e340 SW |
971 | if (!(gh->gh_flags & GL_ASYNC)) |
972 | error = gfs2_glock_wait(gh); | |
b3b94faa | 973 | |
b3b94faa DT |
974 | return error; |
975 | } | |
976 | ||
977 | /** | |
978 | * gfs2_glock_poll - poll to see if an async request has been completed | |
979 | * @gh: the holder | |
980 | * | |
981 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
982 | */ | |
983 | ||
984 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
985 | { | |
6802e340 | 986 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
987 | } |
988 | ||
989 | /** | |
990 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
991 | * @gh: the glock holder | |
992 | * | |
993 | */ | |
994 | ||
995 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
996 | { | |
997 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 998 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 999 | unsigned delay = 0; |
6802e340 | 1000 | int fast_path = 0; |
b3b94faa | 1001 | |
6802e340 | 1002 | spin_lock(&gl->gl_spin); |
b3b94faa | 1003 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1004 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1005 | |
b3b94faa | 1006 | list_del_init(&gh->gh_list); |
6802e340 | 1007 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1008 | if (glops->go_unlock) { |
6802e340 | 1009 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1010 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1011 | glops->go_unlock(gh); |
3042a2cc | 1012 | spin_lock(&gl->gl_spin); |
6802e340 | 1013 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1014 | } |
6802e340 SW |
1015 | if (list_empty(&gl->gl_holders) && |
1016 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1017 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1018 | fast_path = 1; | |
b3b94faa | 1019 | } |
b3b94faa | 1020 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1021 | if (likely(fast_path)) |
1022 | return; | |
c4f68a13 BM |
1023 | |
1024 | gfs2_glock_hold(gl); | |
1025 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1026 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1027 | delay = gl->gl_ops->go_min_hold_time; | |
1028 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1029 | gfs2_glock_put(gl); | |
b3b94faa DT |
1030 | } |
1031 | ||
d93cfa98 AD |
1032 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1033 | { | |
1034 | struct gfs2_glock *gl = gh->gh_gl; | |
1035 | gfs2_glock_dq(gh); | |
1036 | wait_on_demote(gl); | |
1037 | } | |
1038 | ||
b3b94faa DT |
1039 | /** |
1040 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1041 | * @gh: the holder structure | |
1042 | * | |
1043 | */ | |
1044 | ||
1045 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1046 | { | |
1047 | gfs2_glock_dq(gh); | |
1048 | gfs2_holder_uninit(gh); | |
1049 | } | |
1050 | ||
1051 | /** | |
1052 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1053 | * @sdp: the filesystem | |
1054 | * @number: the lock number | |
1055 | * @glops: the glock operations for the type of glock | |
1056 | * @state: the state to acquire the glock in | |
1057 | * @flags: modifier flags for the aquisition | |
1058 | * @gh: the struct gfs2_holder | |
1059 | * | |
1060 | * Returns: errno | |
1061 | */ | |
1062 | ||
cd915493 | 1063 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1064 | const struct gfs2_glock_operations *glops, |
1065 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1066 | { |
1067 | struct gfs2_glock *gl; | |
1068 | int error; | |
1069 | ||
1070 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1071 | if (!error) { | |
1072 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1073 | gfs2_glock_put(gl); | |
1074 | } | |
1075 | ||
1076 | return error; | |
1077 | } | |
1078 | ||
1079 | /** | |
1080 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1081 | * @arg_a: the first structure | |
1082 | * @arg_b: the second structure | |
1083 | * | |
1084 | */ | |
1085 | ||
1086 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1087 | { | |
a5e08a9e SW |
1088 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1089 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1090 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1091 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1092 | |
1093 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1094 | return 1; |
1095 | if (a->ln_number < b->ln_number) | |
1096 | return -1; | |
1c0f4872 | 1097 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1098 | return 0; |
b3b94faa DT |
1099 | } |
1100 | ||
1101 | /** | |
1102 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1103 | * @num_gh: the number of structures | |
1104 | * @ghs: an array of struct gfs2_holder structures | |
1105 | * | |
1106 | * Returns: 0 on success (all glocks acquired), | |
1107 | * errno on failure (no glocks acquired) | |
1108 | */ | |
1109 | ||
1110 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1111 | struct gfs2_holder **p) | |
1112 | { | |
1113 | unsigned int x; | |
1114 | int error = 0; | |
1115 | ||
1116 | for (x = 0; x < num_gh; x++) | |
1117 | p[x] = &ghs[x]; | |
1118 | ||
1119 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1120 | ||
1121 | for (x = 0; x < num_gh; x++) { | |
1122 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1123 | ||
1124 | error = gfs2_glock_nq(p[x]); | |
1125 | if (error) { | |
1126 | while (x--) | |
1127 | gfs2_glock_dq(p[x]); | |
1128 | break; | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | return error; | |
1133 | } | |
1134 | ||
1135 | /** | |
1136 | * gfs2_glock_nq_m - acquire multiple glocks | |
1137 | * @num_gh: the number of structures | |
1138 | * @ghs: an array of struct gfs2_holder structures | |
1139 | * | |
b3b94faa DT |
1140 | * |
1141 | * Returns: 0 on success (all glocks acquired), | |
1142 | * errno on failure (no glocks acquired) | |
1143 | */ | |
1144 | ||
1145 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1146 | { | |
eaf5bd3c SW |
1147 | struct gfs2_holder *tmp[4]; |
1148 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1149 | int error = 0; |
1150 | ||
eaf5bd3c SW |
1151 | switch(num_gh) { |
1152 | case 0: | |
b3b94faa | 1153 | return 0; |
eaf5bd3c | 1154 | case 1: |
b3b94faa DT |
1155 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1156 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1157 | default: |
1158 | if (num_gh <= 4) | |
b3b94faa | 1159 | break; |
eaf5bd3c SW |
1160 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1161 | if (!pph) | |
1162 | return -ENOMEM; | |
b3b94faa DT |
1163 | } |
1164 | ||
eaf5bd3c | 1165 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1166 | |
eaf5bd3c SW |
1167 | if (pph != tmp) |
1168 | kfree(pph); | |
b3b94faa DT |
1169 | |
1170 | return error; | |
1171 | } | |
1172 | ||
1173 | /** | |
1174 | * gfs2_glock_dq_m - release multiple glocks | |
1175 | * @num_gh: the number of structures | |
1176 | * @ghs: an array of struct gfs2_holder structures | |
1177 | * | |
1178 | */ | |
1179 | ||
1180 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1181 | { | |
1182 | unsigned int x; | |
1183 | ||
1184 | for (x = 0; x < num_gh; x++) | |
1185 | gfs2_glock_dq(&ghs[x]); | |
1186 | } | |
1187 | ||
1188 | /** | |
1189 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1190 | * @num_gh: the number of structures | |
1191 | * @ghs: an array of struct gfs2_holder structures | |
1192 | * | |
1193 | */ | |
1194 | ||
1195 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1196 | { | |
1197 | unsigned int x; | |
1198 | ||
1199 | for (x = 0; x < num_gh; x++) | |
1200 | gfs2_glock_dq_uninit(&ghs[x]); | |
1201 | } | |
1202 | ||
f057f6cd | 1203 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1204 | { |
c4f68a13 BM |
1205 | unsigned long delay = 0; |
1206 | unsigned long holdtime; | |
1207 | unsigned long now = jiffies; | |
b3b94faa | 1208 | |
f057f6cd | 1209 | gfs2_glock_hold(gl); |
c4f68a13 BM |
1210 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1211 | if (time_before(now, holdtime)) | |
1212 | delay = holdtime - now; | |
dff52574 SW |
1213 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
1214 | delay = gl->gl_ops->go_min_hold_time; | |
b3b94faa | 1215 | |
6802e340 | 1216 | spin_lock(&gl->gl_spin); |
97cc1025 | 1217 | handle_callback(gl, state, delay); |
6802e340 | 1218 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1219 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1220 | gfs2_glock_put(gl); | |
b3b94faa DT |
1221 | } |
1222 | ||
1223 | /** | |
f057f6cd SW |
1224 | * gfs2_glock_complete - Callback used by locking |
1225 | * @gl: Pointer to the glock | |
1226 | * @ret: The return value from the dlm | |
b3b94faa | 1227 | * |
b3b94faa DT |
1228 | */ |
1229 | ||
f057f6cd | 1230 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1231 | { |
f057f6cd | 1232 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
f057f6cd SW |
1233 | gl->gl_reply = ret; |
1234 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) { | |
1235 | struct gfs2_holder *gh; | |
1236 | spin_lock(&gl->gl_spin); | |
1237 | gh = find_first_waiter(gl); | |
1238 | if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) && | |
1239 | (gl->gl_target != LM_ST_UNLOCKED)) || | |
1240 | ((ret & ~LM_OUT_ST_MASK) != 0)) | |
1241 | set_bit(GLF_FROZEN, &gl->gl_flags); | |
1242 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 1243 | if (test_bit(GLF_FROZEN, &gl->gl_flags)) |
b3b94faa | 1244 | return; |
b3b94faa | 1245 | } |
f057f6cd SW |
1246 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1247 | gfs2_glock_hold(gl); | |
1248 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1249 | gfs2_glock_put(gl); | |
b3b94faa DT |
1250 | } |
1251 | ||
b3b94faa DT |
1252 | /** |
1253 | * demote_ok - Check to see if it's ok to unlock a glock | |
1254 | * @gl: the glock | |
1255 | * | |
1256 | * Returns: 1 if it's ok | |
1257 | */ | |
1258 | ||
97cc1025 | 1259 | static int demote_ok(const struct gfs2_glock *gl) |
b3b94faa | 1260 | { |
8fb4b536 | 1261 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa | 1262 | |
97cc1025 SW |
1263 | if (gl->gl_state == LM_ST_UNLOCKED) |
1264 | return 0; | |
1265 | if (!list_empty(&gl->gl_holders)) | |
1266 | return 0; | |
1267 | if (glops->go_demote_ok) | |
1268 | return glops->go_demote_ok(gl); | |
1269 | return 1; | |
b3b94faa DT |
1270 | } |
1271 | ||
b3b94faa | 1272 | |
97cc1025 | 1273 | static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask) |
b3b94faa DT |
1274 | { |
1275 | struct gfs2_glock *gl; | |
97cc1025 SW |
1276 | int may_demote; |
1277 | int nr_skipped = 0; | |
1278 | int got_ref = 0; | |
1279 | LIST_HEAD(skipped); | |
b3b94faa | 1280 | |
97cc1025 SW |
1281 | if (nr == 0) |
1282 | goto out; | |
b3b94faa | 1283 | |
97cc1025 SW |
1284 | if (!(gfp_mask & __GFP_FS)) |
1285 | return -1; | |
b3b94faa | 1286 | |
97cc1025 SW |
1287 | spin_lock(&lru_lock); |
1288 | while(nr && !list_empty(&lru_list)) { | |
1289 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1290 | list_del_init(&gl->gl_lru); | |
1291 | atomic_dec(&lru_count); | |
1292 | ||
1293 | /* Test for being demotable */ | |
1294 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1295 | gfs2_glock_hold(gl); | |
1296 | got_ref = 1; | |
1297 | spin_unlock(&lru_lock); | |
1298 | spin_lock(&gl->gl_spin); | |
1299 | may_demote = demote_ok(gl); | |
1300 | spin_unlock(&gl->gl_spin); | |
1301 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1302 | if (may_demote) { | |
1303 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1304 | nr--; | |
1305 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1306 | gfs2_glock_put(gl); | |
0c7a531a | 1307 | got_ref = 0; |
97cc1025 SW |
1308 | } |
1309 | spin_lock(&lru_lock); | |
1310 | if (may_demote) | |
1311 | continue; | |
1312 | } | |
1313 | if (list_empty(&gl->gl_lru) && | |
1314 | (atomic_read(&gl->gl_ref) <= (2 + got_ref))) { | |
1315 | nr_skipped++; | |
1316 | list_add(&gl->gl_lru, &skipped); | |
1317 | } | |
1318 | if (got_ref) { | |
1319 | spin_unlock(&lru_lock); | |
1320 | gfs2_glock_put(gl); | |
1321 | spin_lock(&lru_lock); | |
1322 | got_ref = 0; | |
1323 | } | |
b3b94faa | 1324 | } |
97cc1025 SW |
1325 | list_splice(&skipped, &lru_list); |
1326 | atomic_add(nr_skipped, &lru_count); | |
1327 | spin_unlock(&lru_lock); | |
1328 | out: | |
1329 | return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure; | |
b3b94faa DT |
1330 | } |
1331 | ||
97cc1025 SW |
1332 | static struct shrinker glock_shrinker = { |
1333 | .shrink = gfs2_shrink_glock_memory, | |
1334 | .seeks = DEFAULT_SEEKS, | |
1335 | }; | |
1336 | ||
b3b94faa DT |
1337 | /** |
1338 | * examine_bucket - Call a function for glock in a hash bucket | |
1339 | * @examiner: the function | |
1340 | * @sdp: the filesystem | |
1341 | * @bucket: the bucket | |
1342 | * | |
1343 | * Returns: 1 if the bucket has entries | |
1344 | */ | |
1345 | ||
1346 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1347 | unsigned int hash) |
b3b94faa | 1348 | { |
24264434 SW |
1349 | struct gfs2_glock *gl, *prev = NULL; |
1350 | int has_entries = 0; | |
b6397893 | 1351 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1352 | |
24264434 | 1353 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1354 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1355 | if (hlist_empty(head)) | |
24264434 | 1356 | goto out; |
b6397893 SW |
1357 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1358 | while(1) { | |
8fbbfd21 | 1359 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1360 | gfs2_glock_hold(gl); |
24264434 SW |
1361 | read_unlock(gl_lock_addr(hash)); |
1362 | if (prev) | |
1363 | gfs2_glock_put(prev); | |
1364 | prev = gl; | |
1365 | examiner(gl); | |
a8336344 | 1366 | has_entries = 1; |
24264434 | 1367 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1368 | } |
b6397893 SW |
1369 | if (gl->gl_list.next == NULL) |
1370 | break; | |
24264434 | 1371 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1372 | } |
24264434 SW |
1373 | out: |
1374 | read_unlock(gl_lock_addr(hash)); | |
1375 | if (prev) | |
1376 | gfs2_glock_put(prev); | |
8fbbfd21 | 1377 | cond_resched(); |
24264434 | 1378 | return has_entries; |
b3b94faa DT |
1379 | } |
1380 | ||
f057f6cd SW |
1381 | |
1382 | /** | |
1383 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1384 | * @gl: The glock to thaw | |
1385 | * | |
1386 | * N.B. When we freeze a glock, we leave a ref to the glock outstanding, | |
1387 | * so this has to result in the ref count being dropped by one. | |
1388 | */ | |
1389 | ||
1390 | static void thaw_glock(struct gfs2_glock *gl) | |
1391 | { | |
1392 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1393 | return; | |
f057f6cd SW |
1394 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1395 | gfs2_glock_hold(gl); | |
1396 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1397 | gfs2_glock_put(gl); | |
f057f6cd SW |
1398 | } |
1399 | ||
b3b94faa DT |
1400 | /** |
1401 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1402 | * @gl: the glock to look at | |
1403 | * | |
1404 | */ | |
1405 | ||
1406 | static void clear_glock(struct gfs2_glock *gl) | |
1407 | { | |
97cc1025 SW |
1408 | spin_lock(&lru_lock); |
1409 | if (!list_empty(&gl->gl_lru)) { | |
1410 | list_del_init(&gl->gl_lru); | |
1411 | atomic_dec(&lru_count); | |
b3b94faa | 1412 | } |
97cc1025 | 1413 | spin_unlock(&lru_lock); |
b3b94faa | 1414 | |
6802e340 SW |
1415 | spin_lock(&gl->gl_spin); |
1416 | if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED) | |
97cc1025 | 1417 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
6802e340 SW |
1418 | spin_unlock(&gl->gl_spin); |
1419 | gfs2_glock_hold(gl); | |
1420 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1421 | gfs2_glock_put(gl); | |
b3b94faa DT |
1422 | } |
1423 | ||
f057f6cd SW |
1424 | /** |
1425 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1426 | * @sdp: The super block | |
1427 | * | |
1428 | */ | |
1429 | ||
1430 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1431 | { | |
1432 | unsigned x; | |
1433 | ||
1434 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1435 | examine_bucket(thaw_glock, sdp, x); | |
1436 | } | |
1437 | ||
b3b94faa DT |
1438 | /** |
1439 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1440 | * @sdp: the filesystem | |
1441 | * @wait: wait until it's all gone | |
1442 | * | |
1bdad606 | 1443 | * Called when unmounting the filesystem. |
b3b94faa DT |
1444 | */ |
1445 | ||
fefc03bf | 1446 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa DT |
1447 | { |
1448 | unsigned long t; | |
1449 | unsigned int x; | |
1450 | int cont; | |
1451 | ||
1452 | t = jiffies; | |
1453 | ||
1454 | for (;;) { | |
1455 | cont = 0; | |
24264434 | 1456 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1457 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1458 | cont = 1; |
24264434 | 1459 | } |
b3b94faa | 1460 | |
1bdad606 | 1461 | if (!cont) |
b3b94faa DT |
1462 | break; |
1463 | ||
1464 | if (time_after_eq(jiffies, | |
1465 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1466 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1467 | "Dumping lock state...\n"); | |
1468 | gfs2_dump_lockstate(sdp); | |
1469 | t = jiffies; | |
1470 | } | |
1471 | ||
61be084e | 1472 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1473 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1474 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1475 | msleep(10); |
b3b94faa DT |
1476 | } |
1477 | } | |
1478 | ||
813e0c46 SW |
1479 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1480 | { | |
1481 | struct gfs2_glock *gl = ip->i_gl; | |
1482 | int ret; | |
1483 | ||
1484 | ret = gfs2_truncatei_resume(ip); | |
1485 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1486 | ||
1487 | spin_lock(&gl->gl_spin); | |
1488 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1489 | run_queue(gl, 1); | |
1490 | spin_unlock(&gl->gl_spin); | |
1491 | } | |
1492 | ||
6802e340 | 1493 | static const char *state2str(unsigned state) |
04b933f2 | 1494 | { |
6802e340 SW |
1495 | switch(state) { |
1496 | case LM_ST_UNLOCKED: | |
1497 | return "UN"; | |
1498 | case LM_ST_SHARED: | |
1499 | return "SH"; | |
1500 | case LM_ST_DEFERRED: | |
1501 | return "DF"; | |
1502 | case LM_ST_EXCLUSIVE: | |
1503 | return "EX"; | |
1504 | } | |
1505 | return "??"; | |
1506 | } | |
1507 | ||
1508 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1509 | { | |
1510 | char *p = buf; | |
1511 | if (flags & LM_FLAG_TRY) | |
1512 | *p++ = 't'; | |
1513 | if (flags & LM_FLAG_TRY_1CB) | |
1514 | *p++ = 'T'; | |
1515 | if (flags & LM_FLAG_NOEXP) | |
1516 | *p++ = 'e'; | |
1517 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1518 | *p++ = 'A'; |
6802e340 SW |
1519 | if (flags & LM_FLAG_PRIORITY) |
1520 | *p++ = 'p'; | |
1521 | if (flags & GL_ASYNC) | |
1522 | *p++ = 'a'; | |
1523 | if (flags & GL_EXACT) | |
1524 | *p++ = 'E'; | |
6802e340 SW |
1525 | if (flags & GL_NOCACHE) |
1526 | *p++ = 'c'; | |
1527 | if (test_bit(HIF_HOLDER, &iflags)) | |
1528 | *p++ = 'H'; | |
1529 | if (test_bit(HIF_WAIT, &iflags)) | |
1530 | *p++ = 'W'; | |
1531 | if (test_bit(HIF_FIRST, &iflags)) | |
1532 | *p++ = 'F'; | |
1533 | *p = 0; | |
1534 | return buf; | |
04b933f2 RP |
1535 | } |
1536 | ||
b3b94faa DT |
1537 | /** |
1538 | * dump_holder - print information about a glock holder | |
6802e340 | 1539 | * @seq: the seq_file struct |
b3b94faa DT |
1540 | * @gh: the glock holder |
1541 | * | |
1542 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1543 | */ | |
1544 | ||
6802e340 | 1545 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1546 | { |
6802e340 SW |
1547 | struct task_struct *gh_owner = NULL; |
1548 | char buffer[KSYM_SYMBOL_LEN]; | |
1549 | char flags_buf[32]; | |
b3b94faa | 1550 | |
6802e340 SW |
1551 | sprint_symbol(buffer, gh->gh_ip); |
1552 | if (gh->gh_owner_pid) | |
b1e058da | 1553 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
6802e340 SW |
1554 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", |
1555 | state2str(gh->gh_state), | |
1556 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1557 | gh->gh_error, | |
1558 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1559 | gh_owner ? gh_owner->comm : "(ended)", buffer); | |
7c52b166 | 1560 | return 0; |
b3b94faa DT |
1561 | } |
1562 | ||
6802e340 SW |
1563 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1564 | { | |
1565 | char *p = buf; | |
1566 | if (test_bit(GLF_LOCK, gflags)) | |
1567 | *p++ = 'l'; | |
6802e340 SW |
1568 | if (test_bit(GLF_DEMOTE, gflags)) |
1569 | *p++ = 'D'; | |
1570 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1571 | *p++ = 'd'; | |
1572 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1573 | *p++ = 'p'; | |
1574 | if (test_bit(GLF_DIRTY, gflags)) | |
1575 | *p++ = 'y'; | |
1576 | if (test_bit(GLF_LFLUSH, gflags)) | |
1577 | *p++ = 'f'; | |
1578 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1579 | *p++ = 'i'; | |
1580 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1581 | *p++ = 'r'; | |
f057f6cd | 1582 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1583 | *p++ = 'I'; |
f057f6cd SW |
1584 | if (test_bit(GLF_FROZEN, gflags)) |
1585 | *p++ = 'F'; | |
6802e340 SW |
1586 | *p = 0; |
1587 | return buf; | |
b3b94faa DT |
1588 | } |
1589 | ||
1590 | /** | |
6802e340 SW |
1591 | * __dump_glock - print information about a glock |
1592 | * @seq: The seq_file struct | |
b3b94faa | 1593 | * @gl: the glock |
6802e340 SW |
1594 | * |
1595 | * The file format is as follows: | |
1596 | * One line per object, capital letters are used to indicate objects | |
1597 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1598 | * other objects are indented by a single space and follow the glock to | |
1599 | * which they are related. Fields are indicated by lower case letters | |
1600 | * followed by a colon and the field value, except for strings which are in | |
1601 | * [] so that its possible to see if they are composed of spaces for | |
1602 | * example. The field's are n = number (id of the object), f = flags, | |
1603 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1604 | * |
1605 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1606 | */ | |
1607 | ||
6802e340 | 1608 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1609 | { |
6802e340 SW |
1610 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1611 | unsigned long long dtime; | |
1612 | const struct gfs2_holder *gh; | |
1613 | char gflags_buf[32]; | |
1614 | int error = 0; | |
b3b94faa | 1615 | |
6802e340 SW |
1616 | dtime = jiffies - gl->gl_demote_time; |
1617 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1618 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1619 | dtime = 0; | |
f057f6cd | 1620 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu a:%d r:%d\n", |
6802e340 SW |
1621 | state2str(gl->gl_state), |
1622 | gl->gl_name.ln_type, | |
1623 | (unsigned long long)gl->gl_name.ln_number, | |
1624 | gflags2str(gflags_buf, &gl->gl_flags), | |
1625 | state2str(gl->gl_target), | |
1626 | state2str(gl->gl_demote_state), dtime, | |
6802e340 SW |
1627 | atomic_read(&gl->gl_ail_count), |
1628 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1629 | |
b3b94faa | 1630 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1631 | error = dump_holder(seq, gh); |
b3b94faa DT |
1632 | if (error) |
1633 | goto out; | |
1634 | } | |
6802e340 SW |
1635 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1636 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1637 | out: |
b3b94faa DT |
1638 | return error; |
1639 | } | |
1640 | ||
6802e340 SW |
1641 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1642 | { | |
1643 | int ret; | |
1644 | spin_lock(&gl->gl_spin); | |
1645 | ret = __dump_glock(seq, gl); | |
1646 | spin_unlock(&gl->gl_spin); | |
1647 | return ret; | |
1648 | } | |
1649 | ||
b3b94faa DT |
1650 | /** |
1651 | * gfs2_dump_lockstate - print out the current lockstate | |
1652 | * @sdp: the filesystem | |
1653 | * @ub: the buffer to copy the information into | |
1654 | * | |
1655 | * If @ub is NULL, dump the lockstate to the console. | |
1656 | * | |
1657 | */ | |
1658 | ||
08bc2dbc | 1659 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1660 | { |
b3b94faa | 1661 | struct gfs2_glock *gl; |
b6397893 | 1662 | struct hlist_node *h; |
b3b94faa DT |
1663 | unsigned int x; |
1664 | int error = 0; | |
1665 | ||
1666 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1667 | |
087efdd3 | 1668 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1669 | |
b6397893 | 1670 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1671 | if (gl->gl_sbd != sdp) |
1672 | continue; | |
b3b94faa | 1673 | |
7c52b166 | 1674 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1675 | if (error) |
1676 | break; | |
1677 | } | |
1678 | ||
087efdd3 | 1679 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1680 | |
1681 | if (error) | |
1682 | break; | |
1683 | } | |
1684 | ||
1685 | ||
1686 | return error; | |
1687 | } | |
1688 | ||
8fbbfd21 | 1689 | |
85d1da67 SW |
1690 | int __init gfs2_glock_init(void) |
1691 | { | |
1692 | unsigned i; | |
1693 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1694 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1695 | } |
087efdd3 SW |
1696 | #ifdef GL_HASH_LOCK_SZ |
1697 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1698 | rwlock_init(&gl_hash_locks[i]); | |
1699 | } | |
1700 | #endif | |
8fbbfd21 | 1701 | |
c4f68a13 | 1702 | glock_workqueue = create_workqueue("glock_workqueue"); |
97cc1025 | 1703 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1704 | return PTR_ERR(glock_workqueue); |
97cc1025 SW |
1705 | |
1706 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1707 | |
85d1da67 SW |
1708 | return 0; |
1709 | } | |
1710 | ||
8fbbfd21 SW |
1711 | void gfs2_glock_exit(void) |
1712 | { | |
97cc1025 | 1713 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1714 | destroy_workqueue(glock_workqueue); |
8fbbfd21 SW |
1715 | } |
1716 | ||
6802e340 | 1717 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1718 | { |
7b08fc62 SW |
1719 | struct gfs2_glock *gl; |
1720 | ||
a947e033 | 1721 | restart: |
7a0079d9 | 1722 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1723 | gl = gi->gl; |
1724 | if (gl) { | |
a947e033 AD |
1725 | gi->gl = hlist_entry(gl->gl_list.next, |
1726 | struct gfs2_glock, gl_list); | |
c1e817d0 SW |
1727 | } else { |
1728 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1729 | struct gfs2_glock, gl_list); | |
7c52b166 | 1730 | } |
c1e817d0 SW |
1731 | if (gi->gl) |
1732 | gfs2_glock_hold(gi->gl); | |
7a0079d9 | 1733 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1734 | if (gl) |
1735 | gfs2_glock_put(gl); | |
6802e340 | 1736 | while (gi->gl == NULL) { |
c1e817d0 | 1737 | gi->hash++; |
7b08fc62 SW |
1738 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
1739 | return 1; | |
1740 | read_lock(gl_lock_addr(gi->hash)); | |
1741 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1742 | struct gfs2_glock, gl_list); | |
1743 | if (gi->gl) | |
1744 | gfs2_glock_hold(gi->gl); | |
1745 | read_unlock(gl_lock_addr(gi->hash)); | |
1746 | } | |
a947e033 AD |
1747 | |
1748 | if (gi->sdp != gi->gl->gl_sbd) | |
1749 | goto restart; | |
1750 | ||
7c52b166 RP |
1751 | return 0; |
1752 | } | |
1753 | ||
6802e340 | 1754 | static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) |
7c52b166 | 1755 | { |
7b08fc62 SW |
1756 | if (gi->gl) |
1757 | gfs2_glock_put(gi->gl); | |
a947e033 | 1758 | gi->gl = NULL; |
7c52b166 RP |
1759 | } |
1760 | ||
6802e340 | 1761 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1762 | { |
6802e340 | 1763 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1764 | loff_t n = *pos; |
1765 | ||
6802e340 | 1766 | gi->hash = 0; |
7c52b166 | 1767 | |
6802e340 | 1768 | do { |
7c52b166 RP |
1769 | if (gfs2_glock_iter_next(gi)) { |
1770 | gfs2_glock_iter_free(gi); | |
1771 | return NULL; | |
1772 | } | |
6802e340 | 1773 | } while (n--); |
7c52b166 | 1774 | |
6802e340 | 1775 | return gi->gl; |
7c52b166 RP |
1776 | } |
1777 | ||
6802e340 | 1778 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1779 | loff_t *pos) |
1780 | { | |
6802e340 | 1781 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1782 | |
1783 | (*pos)++; | |
1784 | ||
1785 | if (gfs2_glock_iter_next(gi)) { | |
1786 | gfs2_glock_iter_free(gi); | |
1787 | return NULL; | |
1788 | } | |
1789 | ||
6802e340 | 1790 | return gi->gl; |
7c52b166 RP |
1791 | } |
1792 | ||
6802e340 | 1793 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1794 | { |
6802e340 SW |
1795 | struct gfs2_glock_iter *gi = seq->private; |
1796 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
1797 | } |
1798 | ||
6802e340 | 1799 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1800 | { |
6802e340 | 1801 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1802 | } |
1803 | ||
4ef29002 | 1804 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1805 | .start = gfs2_glock_seq_start, |
1806 | .next = gfs2_glock_seq_next, | |
1807 | .stop = gfs2_glock_seq_stop, | |
1808 | .show = gfs2_glock_seq_show, | |
1809 | }; | |
1810 | ||
1811 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1812 | { | |
6802e340 SW |
1813 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1814 | sizeof(struct gfs2_glock_iter)); | |
1815 | if (ret == 0) { | |
1816 | struct seq_file *seq = file->private_data; | |
1817 | struct gfs2_glock_iter *gi = seq->private; | |
1818 | gi->sdp = inode->i_private; | |
1819 | } | |
1820 | return ret; | |
7c52b166 RP |
1821 | } |
1822 | ||
1823 | static const struct file_operations gfs2_debug_fops = { | |
1824 | .owner = THIS_MODULE, | |
1825 | .open = gfs2_debugfs_open, | |
1826 | .read = seq_read, | |
1827 | .llseek = seq_lseek, | |
6802e340 | 1828 | .release = seq_release_private, |
7c52b166 RP |
1829 | }; |
1830 | ||
1831 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1832 | { | |
5f882096 RP |
1833 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1834 | if (!sdp->debugfs_dir) | |
1835 | return -ENOMEM; | |
1836 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1837 | S_IFREG | S_IRUGO, | |
1838 | sdp->debugfs_dir, sdp, | |
1839 | &gfs2_debug_fops); | |
1840 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1841 | return -ENOMEM; |
1842 | ||
1843 | return 0; | |
1844 | } | |
1845 | ||
1846 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1847 | { | |
5f882096 RP |
1848 | if (sdp && sdp->debugfs_dir) { |
1849 | if (sdp->debugfs_dentry_glocks) { | |
1850 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1851 | sdp->debugfs_dentry_glocks = NULL; | |
1852 | } | |
1853 | debugfs_remove(sdp->debugfs_dir); | |
1854 | sdp->debugfs_dir = NULL; | |
1855 | } | |
7c52b166 RP |
1856 | } |
1857 | ||
1858 | int gfs2_register_debugfs(void) | |
1859 | { | |
1860 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1861 | return gfs2_root ? 0 : -ENOMEM; | |
1862 | } | |
1863 | ||
1864 | void gfs2_unregister_debugfs(void) | |
1865 | { | |
1866 | debugfs_remove(gfs2_root); | |
5f882096 | 1867 | gfs2_root = NULL; |
7c52b166 | 1868 | } |