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authorLinus Torvalds <torvalds@g5.osdl.org>2006-10-04 12:06:16 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-04 12:06:16 -0400
commit4a61f17378c2cdd9bd8f34ef8bd7422861d0c1f1 (patch)
treea2054556900af8c16fd9f5419f012dcf1ee2995a /fs/gfs2/locking/dlm/lock.c
parentd002ec481c24f325ed6cfcb7810d317c015dd1b5 (diff)
parent7ecdb70a0ea436c06540140242bfac6ac3babfc0 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6: (292 commits) [GFS2] Fix endian bug for de_type [GFS2] Initialize SELinux extended attributes at inode creation time. [GFS2] Move logging code into log.c (mostly) [GFS2] Mark nlink cleared so VFS sees it happen [GFS2] Two redundant casts removed [GFS2] Remove uneeded endian conversion [GFS2] Remove duplicate sb reading code [GFS2] Mark metadata reads for blktrace [GFS2] Remove iflags.h, use FS_ [GFS2] Fix code style/indent in ops_file.c [GFS2] streamline-generic_file_-interfaces-and-filemap gfs fix [GFS2] Remove readv/writev methods and use aio_read/aio_write instead (gfs bits) [GFS2] inode-diet: Eliminate i_blksize from the inode structure [GFS2] inode_diet: Replace inode.u.generic_ip with inode.i_private (gfs) [GFS2] Fix typo in last patch [GFS2] Fix direct i/o logic in filemap.c [GFS2] Fix bug in Makefiles for lock modules [GFS2] Remove (extra) fs_subsys declaration [GFS2/DLM] Fix trailing whitespace [GFS2] Tidy up meta_io code ...
Diffstat (limited to 'fs/gfs2/locking/dlm/lock.c')
-rw-r--r--fs/gfs2/locking/dlm/lock.c524
1 files changed, 524 insertions, 0 deletions
diff --git a/fs/gfs2/locking/dlm/lock.c b/fs/gfs2/locking/dlm/lock.c
new file mode 100644
index 000000000000..b167addf9fd1
--- /dev/null
+++ b/fs/gfs2/locking/dlm/lock.c
@@ -0,0 +1,524 @@
1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10#include "lock_dlm.h"
11
12static char junk_lvb[GDLM_LVB_SIZE];
13
14static void queue_complete(struct gdlm_lock *lp)
15{
16 struct gdlm_ls *ls = lp->ls;
17
18 clear_bit(LFL_ACTIVE, &lp->flags);
19
20 spin_lock(&ls->async_lock);
21 list_add_tail(&lp->clist, &ls->complete);
22 spin_unlock(&ls->async_lock);
23 wake_up(&ls->thread_wait);
24}
25
26static inline void gdlm_ast(void *astarg)
27{
28 queue_complete(astarg);
29}
30
31static inline void gdlm_bast(void *astarg, int mode)
32{
33 struct gdlm_lock *lp = astarg;
34 struct gdlm_ls *ls = lp->ls;
35
36 if (!mode) {
37 printk(KERN_INFO "lock_dlm: bast mode zero %x,%llx\n",
38 lp->lockname.ln_type,
39 (unsigned long long)lp->lockname.ln_number);
40 return;
41 }
42
43 spin_lock(&ls->async_lock);
44 if (!lp->bast_mode) {
45 list_add_tail(&lp->blist, &ls->blocking);
46 lp->bast_mode = mode;
47 } else if (lp->bast_mode < mode)
48 lp->bast_mode = mode;
49 spin_unlock(&ls->async_lock);
50 wake_up(&ls->thread_wait);
51}
52
53void gdlm_queue_delayed(struct gdlm_lock *lp)
54{
55 struct gdlm_ls *ls = lp->ls;
56
57 spin_lock(&ls->async_lock);
58 list_add_tail(&lp->delay_list, &ls->delayed);
59 spin_unlock(&ls->async_lock);
60}
61
62/* convert gfs lock-state to dlm lock-mode */
63
64static s16 make_mode(s16 lmstate)
65{
66 switch (lmstate) {
67 case LM_ST_UNLOCKED:
68 return DLM_LOCK_NL;
69 case LM_ST_EXCLUSIVE:
70 return DLM_LOCK_EX;
71 case LM_ST_DEFERRED:
72 return DLM_LOCK_CW;
73 case LM_ST_SHARED:
74 return DLM_LOCK_PR;
75 }
76 gdlm_assert(0, "unknown LM state %d", lmstate);
77 return -1;
78}
79
80/* convert dlm lock-mode to gfs lock-state */
81
82s16 gdlm_make_lmstate(s16 dlmmode)
83{
84 switch (dlmmode) {
85 case DLM_LOCK_IV:
86 case DLM_LOCK_NL:
87 return LM_ST_UNLOCKED;
88 case DLM_LOCK_EX:
89 return LM_ST_EXCLUSIVE;
90 case DLM_LOCK_CW:
91 return LM_ST_DEFERRED;
92 case DLM_LOCK_PR:
93 return LM_ST_SHARED;
94 }
95 gdlm_assert(0, "unknown DLM mode %d", dlmmode);
96 return -1;
97}
98
99/* verify agreement with GFS on the current lock state, NB: DLM_LOCK_NL and
100 DLM_LOCK_IV are both considered LM_ST_UNLOCKED by GFS. */
101
102static void check_cur_state(struct gdlm_lock *lp, unsigned int cur_state)
103{
104 s16 cur = make_mode(cur_state);
105 if (lp->cur != DLM_LOCK_IV)
106 gdlm_assert(lp->cur == cur, "%d, %d", lp->cur, cur);
107}
108
109static inline unsigned int make_flags(struct gdlm_lock *lp,
110 unsigned int gfs_flags,
111 s16 cur, s16 req)
112{
113 unsigned int lkf = 0;
114
115 if (gfs_flags & LM_FLAG_TRY)
116 lkf |= DLM_LKF_NOQUEUE;
117
118 if (gfs_flags & LM_FLAG_TRY_1CB) {
119 lkf |= DLM_LKF_NOQUEUE;
120 lkf |= DLM_LKF_NOQUEUEBAST;
121 }
122
123 if (gfs_flags & LM_FLAG_PRIORITY) {
124 lkf |= DLM_LKF_NOORDER;
125 lkf |= DLM_LKF_HEADQUE;
126 }
127
128 if (gfs_flags & LM_FLAG_ANY) {
129 if (req == DLM_LOCK_PR)
130 lkf |= DLM_LKF_ALTCW;
131 else if (req == DLM_LOCK_CW)
132 lkf |= DLM_LKF_ALTPR;
133 }
134
135 if (lp->lksb.sb_lkid != 0) {
136 lkf |= DLM_LKF_CONVERT;
137
138 /* Conversion deadlock avoidance by DLM */
139
140 if (!test_bit(LFL_FORCE_PROMOTE, &lp->flags) &&
141 !(lkf & DLM_LKF_NOQUEUE) &&
142 cur > DLM_LOCK_NL && req > DLM_LOCK_NL && cur != req)
143 lkf |= DLM_LKF_CONVDEADLK;
144 }
145
146 if (lp->lvb)
147 lkf |= DLM_LKF_VALBLK;
148
149 return lkf;
150}
151
152/* make_strname - convert GFS lock numbers to a string */
153
154static inline void make_strname(struct lm_lockname *lockname,
155 struct gdlm_strname *str)
156{
157 sprintf(str->name, "%8x%16llx", lockname->ln_type,
158 (unsigned long long)lockname->ln_number);
159 str->namelen = GDLM_STRNAME_BYTES;
160}
161
162static int gdlm_create_lp(struct gdlm_ls *ls, struct lm_lockname *name,
163 struct gdlm_lock **lpp)
164{
165 struct gdlm_lock *lp;
166
167 lp = kzalloc(sizeof(struct gdlm_lock), GFP_KERNEL);
168 if (!lp)
169 return -ENOMEM;
170
171 lp->lockname = *name;
172 lp->ls = ls;
173 lp->cur = DLM_LOCK_IV;
174 lp->lvb = NULL;
175 lp->hold_null = NULL;
176 init_completion(&lp->ast_wait);
177 INIT_LIST_HEAD(&lp->clist);
178 INIT_LIST_HEAD(&lp->blist);
179 INIT_LIST_HEAD(&lp->delay_list);
180
181 spin_lock(&ls->async_lock);
182 list_add(&lp->all_list, &ls->all_locks);
183 ls->all_locks_count++;
184 spin_unlock(&ls->async_lock);
185
186 *lpp = lp;
187 return 0;
188}
189
190void gdlm_delete_lp(struct gdlm_lock *lp)
191{
192 struct gdlm_ls *ls = lp->ls;
193
194 spin_lock(&ls->async_lock);
195 if (!list_empty(&lp->clist))
196 list_del_init(&lp->clist);
197 if (!list_empty(&lp->blist))
198 list_del_init(&lp->blist);
199 if (!list_empty(&lp->delay_list))
200 list_del_init(&lp->delay_list);
201 gdlm_assert(!list_empty(&lp->all_list), "%x,%llx", lp->lockname.ln_type,
202 (unsigned long long)lp->lockname.ln_number);
203 list_del_init(&lp->all_list);
204 ls->all_locks_count--;
205 spin_unlock(&ls->async_lock);
206
207 kfree(lp);
208}
209
210int gdlm_get_lock(void *lockspace, struct lm_lockname *name,
211 void **lockp)
212{
213 struct gdlm_lock *lp;
214 int error;
215
216 error = gdlm_create_lp(lockspace, name, &lp);
217
218 *lockp = lp;
219 return error;
220}
221
222void gdlm_put_lock(void *lock)
223{
224 gdlm_delete_lp(lock);
225}
226
227unsigned int gdlm_do_lock(struct gdlm_lock *lp)
228{
229 struct gdlm_ls *ls = lp->ls;
230 struct gdlm_strname str;
231 int error, bast = 1;
232
233 /*
234 * When recovery is in progress, delay lock requests for submission
235 * once recovery is done. Requests for recovery (NOEXP) and unlocks
236 * can pass.
237 */
238
239 if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) &&
240 !test_bit(LFL_NOBLOCK, &lp->flags) && lp->req != DLM_LOCK_NL) {
241 gdlm_queue_delayed(lp);
242 return LM_OUT_ASYNC;
243 }
244
245 /*
246 * Submit the actual lock request.
247 */
248
249 if (test_bit(LFL_NOBAST, &lp->flags))
250 bast = 0;
251
252 make_strname(&lp->lockname, &str);
253
254 set_bit(LFL_ACTIVE, &lp->flags);
255
256 log_debug("lk %x,%llx id %x %d,%d %x", lp->lockname.ln_type,
257 (unsigned long long)lp->lockname.ln_number, lp->lksb.sb_lkid,
258 lp->cur, lp->req, lp->lkf);
259
260 error = dlm_lock(ls->dlm_lockspace, lp->req, &lp->lksb, lp->lkf,
261 str.name, str.namelen, 0, gdlm_ast, lp,
262 bast ? gdlm_bast : NULL);
263
264 if ((error == -EAGAIN) && (lp->lkf & DLM_LKF_NOQUEUE)) {
265 lp->lksb.sb_status = -EAGAIN;
266 queue_complete(lp);
267 error = 0;
268 }
269
270 if (error) {
271 log_debug("%s: gdlm_lock %x,%llx err=%d cur=%d req=%d lkf=%x "
272 "flags=%lx", ls->fsname, lp->lockname.ln_type,
273 (unsigned long long)lp->lockname.ln_number, error,
274 lp->cur, lp->req, lp->lkf, lp->flags);
275 return LM_OUT_ERROR;
276 }
277 return LM_OUT_ASYNC;
278}
279
280static unsigned int gdlm_do_unlock(struct gdlm_lock *lp)
281{
282 struct gdlm_ls *ls = lp->ls;
283 unsigned int lkf = 0;
284 int error;
285
286 set_bit(LFL_DLM_UNLOCK, &lp->flags);
287 set_bit(LFL_ACTIVE, &lp->flags);
288
289 if (lp->lvb)
290 lkf = DLM_LKF_VALBLK;
291
292 log_debug("un %x,%llx %x %d %x", lp->lockname.ln_type,
293 (unsigned long long)lp->lockname.ln_number,
294 lp->lksb.sb_lkid, lp->cur, lkf);
295
296 error = dlm_unlock(ls->dlm_lockspace, lp->lksb.sb_lkid, lkf, NULL, lp);
297
298 if (error) {
299 log_debug("%s: gdlm_unlock %x,%llx err=%d cur=%d req=%d lkf=%x "
300 "flags=%lx", ls->fsname, lp->lockname.ln_type,
301 (unsigned long long)lp->lockname.ln_number, error,
302 lp->cur, lp->req, lp->lkf, lp->flags);
303 return LM_OUT_ERROR;
304 }
305 return LM_OUT_ASYNC;
306}
307
308unsigned int gdlm_lock(void *lock, unsigned int cur_state,
309 unsigned int req_state, unsigned int flags)
310{
311 struct gdlm_lock *lp = lock;
312
313 clear_bit(LFL_DLM_CANCEL, &lp->flags);
314 if (flags & LM_FLAG_NOEXP)
315 set_bit(LFL_NOBLOCK, &lp->flags);
316
317 check_cur_state(lp, cur_state);
318 lp->req = make_mode(req_state);
319 lp->lkf = make_flags(lp, flags, lp->cur, lp->req);
320
321 return gdlm_do_lock(lp);
322}
323
324unsigned int gdlm_unlock(void *lock, unsigned int cur_state)
325{
326 struct gdlm_lock *lp = lock;
327
328 clear_bit(LFL_DLM_CANCEL, &lp->flags);
329 if (lp->cur == DLM_LOCK_IV)
330 return 0;
331 return gdlm_do_unlock(lp);
332}
333
334void gdlm_cancel(void *lock)
335{
336 struct gdlm_lock *lp = lock;
337 struct gdlm_ls *ls = lp->ls;
338 int error, delay_list = 0;
339
340 if (test_bit(LFL_DLM_CANCEL, &lp->flags))
341 return;
342
343 log_info("gdlm_cancel %x,%llx flags %lx", lp->lockname.ln_type,
344 (unsigned long long)lp->lockname.ln_number, lp->flags);
345
346 spin_lock(&ls->async_lock);
347 if (!list_empty(&lp->delay_list)) {
348 list_del_init(&lp->delay_list);
349 delay_list = 1;
350 }
351 spin_unlock(&ls->async_lock);
352
353 if (delay_list) {
354 set_bit(LFL_CANCEL, &lp->flags);
355 set_bit(LFL_ACTIVE, &lp->flags);
356 queue_complete(lp);
357 return;
358 }
359
360 if (!test_bit(LFL_ACTIVE, &lp->flags) ||
361 test_bit(LFL_DLM_UNLOCK, &lp->flags)) {
362 log_info("gdlm_cancel skip %x,%llx flags %lx",
363 lp->lockname.ln_type,
364 (unsigned long long)lp->lockname.ln_number, lp->flags);
365 return;
366 }
367
368 /* the lock is blocked in the dlm */
369
370 set_bit(LFL_DLM_CANCEL, &lp->flags);
371 set_bit(LFL_ACTIVE, &lp->flags);
372
373 error = dlm_unlock(ls->dlm_lockspace, lp->lksb.sb_lkid, DLM_LKF_CANCEL,
374 NULL, lp);
375
376 log_info("gdlm_cancel rv %d %x,%llx flags %lx", error,
377 lp->lockname.ln_type,
378 (unsigned long long)lp->lockname.ln_number, lp->flags);
379
380 if (error == -EBUSY)
381 clear_bit(LFL_DLM_CANCEL, &lp->flags);
382}
383
384static int gdlm_add_lvb(struct gdlm_lock *lp)
385{
386 char *lvb;
387
388 lvb = kzalloc(GDLM_LVB_SIZE, GFP_KERNEL);
389 if (!lvb)
390 return -ENOMEM;
391
392 lp->lksb.sb_lvbptr = lvb;
393 lp->lvb = lvb;
394 return 0;
395}
396
397static void gdlm_del_lvb(struct gdlm_lock *lp)
398{
399 kfree(lp->lvb);
400 lp->lvb = NULL;
401 lp->lksb.sb_lvbptr = NULL;
402}
403
404/* This can do a synchronous dlm request (requiring a lock_dlm thread to get
405 the completion) because gfs won't call hold_lvb() during a callback (from
406 the context of a lock_dlm thread). */
407
408static int hold_null_lock(struct gdlm_lock *lp)
409{
410 struct gdlm_lock *lpn = NULL;
411 int error;
412
413 if (lp->hold_null) {
414 printk(KERN_INFO "lock_dlm: lvb already held\n");
415 return 0;
416 }
417
418 error = gdlm_create_lp(lp->ls, &lp->lockname, &lpn);
419 if (error)
420 goto out;
421
422 lpn->lksb.sb_lvbptr = junk_lvb;
423 lpn->lvb = junk_lvb;
424
425 lpn->req = DLM_LOCK_NL;
426 lpn->lkf = DLM_LKF_VALBLK | DLM_LKF_EXPEDITE;
427 set_bit(LFL_NOBAST, &lpn->flags);
428 set_bit(LFL_INLOCK, &lpn->flags);
429
430 init_completion(&lpn->ast_wait);
431 gdlm_do_lock(lpn);
432 wait_for_completion(&lpn->ast_wait);
433 error = lpn->lksb.sb_status;
434 if (error) {
435 printk(KERN_INFO "lock_dlm: hold_null_lock dlm error %d\n",
436 error);
437 gdlm_delete_lp(lpn);
438 lpn = NULL;
439 }
440out:
441 lp->hold_null = lpn;
442 return error;
443}
444
445/* This cannot do a synchronous dlm request (requiring a lock_dlm thread to get
446 the completion) because gfs may call unhold_lvb() during a callback (from
447 the context of a lock_dlm thread) which could cause a deadlock since the
448 other lock_dlm thread could be engaged in recovery. */
449
450static void unhold_null_lock(struct gdlm_lock *lp)
451{
452 struct gdlm_lock *lpn = lp->hold_null;
453
454 gdlm_assert(lpn, "%x,%llx", lp->lockname.ln_type,
455 (unsigned long long)lp->lockname.ln_number);
456 lpn->lksb.sb_lvbptr = NULL;
457 lpn->lvb = NULL;
458 set_bit(LFL_UNLOCK_DELETE, &lpn->flags);
459 gdlm_do_unlock(lpn);
460 lp->hold_null = NULL;
461}
462
463/* Acquire a NL lock because gfs requires the value block to remain
464 intact on the resource while the lvb is "held" even if it's holding no locks
465 on the resource. */
466
467int gdlm_hold_lvb(void *lock, char **lvbp)
468{
469 struct gdlm_lock *lp = lock;
470 int error;
471
472 error = gdlm_add_lvb(lp);
473 if (error)
474 return error;
475
476 *lvbp = lp->lvb;
477
478 error = hold_null_lock(lp);
479 if (error)
480 gdlm_del_lvb(lp);
481
482 return error;
483}
484
485void gdlm_unhold_lvb(void *lock, char *lvb)
486{
487 struct gdlm_lock *lp = lock;
488
489 unhold_null_lock(lp);
490 gdlm_del_lvb(lp);
491}
492
493void gdlm_submit_delayed(struct gdlm_ls *ls)
494{
495 struct gdlm_lock *lp, *safe;
496
497 spin_lock(&ls->async_lock);
498 list_for_each_entry_safe(lp, safe, &ls->delayed, delay_list) {
499 list_del_init(&lp->delay_list);
500 list_add_tail(&lp->delay_list, &ls->submit);
501 }
502 spin_unlock(&ls->async_lock);
503 wake_up(&ls->thread_wait);
504}
505
506int gdlm_release_all_locks(struct gdlm_ls *ls)
507{
508 struct gdlm_lock *lp, *safe;
509 int count = 0;
510
511 spin_lock(&ls->async_lock);
512 list_for_each_entry_safe(lp, safe, &ls->all_locks, all_list) {
513 list_del_init(&lp->all_list);
514
515 if (lp->lvb && lp->lvb != junk_lvb)
516 kfree(lp->lvb);
517 kfree(lp);
518 count++;
519 }
520 spin_unlock(&ls->async_lock);
521
522 return count;
523}
524