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" |
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; |
97cc1025 SW |
66 | static LIST_HEAD(lru_list); |
67 | static atomic_t lru_count = ATOMIC_INIT(0); | |
eb8374e7 | 68 | static DEFINE_SPINLOCK(lru_lock); |
08bc2dbc | 69 | |
b6397893 | 70 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
71 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
72 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
73 | ||
85d1da67 | 74 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 75 | static struct dentry *gfs2_root; |
087efdd3 SW |
76 | |
77 | /* | |
78 | * Despite what you might think, the numbers below are not arbitrary :-) | |
79 | * They are taken from the ipv4 routing hash code, which is well tested | |
80 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
81 | * but for now this should be fine. | |
82 | * | |
83 | * The reason for putting the locks in a separate array from the list heads | |
84 | * is that we can have fewer locks than list heads and save memory. We use | |
85 | * the same hash function for both, but with a different hash mask. | |
86 | */ | |
87 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
88 | defined(CONFIG_PROVE_LOCKING) | |
89 | ||
90 | #ifdef CONFIG_LOCKDEP | |
91 | # define GL_HASH_LOCK_SZ 256 | |
92 | #else | |
93 | # if NR_CPUS >= 32 | |
94 | # define GL_HASH_LOCK_SZ 4096 | |
95 | # elif NR_CPUS >= 16 | |
96 | # define GL_HASH_LOCK_SZ 2048 | |
97 | # elif NR_CPUS >= 8 | |
98 | # define GL_HASH_LOCK_SZ 1024 | |
99 | # elif NR_CPUS >= 4 | |
100 | # define GL_HASH_LOCK_SZ 512 | |
101 | # else | |
102 | # define GL_HASH_LOCK_SZ 256 | |
103 | # endif | |
104 | #endif | |
105 | ||
106 | /* We never want more locks than chains */ | |
107 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
108 | # undef GL_HASH_LOCK_SZ | |
109 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
110 | #endif | |
111 | ||
112 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
113 | ||
114 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
115 | { | |
94610610 | 116 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
117 | } |
118 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 119 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
120 | { |
121 | return NULL; | |
122 | } | |
123 | #endif | |
85d1da67 | 124 | |
b3b94faa DT |
125 | /** |
126 | * gl_hash() - Turn glock number into hash bucket number | |
127 | * @lock: The glock number | |
128 | * | |
129 | * Returns: The number of the corresponding hash bucket | |
130 | */ | |
131 | ||
b8547856 SW |
132 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
133 | const struct lm_lockname *name) | |
b3b94faa DT |
134 | { |
135 | unsigned int h; | |
136 | ||
cd915493 | 137 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 138 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 139 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
140 | h &= GFS2_GL_HASH_MASK; |
141 | ||
142 | return h; | |
143 | } | |
144 | ||
145 | /** | |
146 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
147 | * @gl: The glock to release | |
148 | * | |
149 | * Also calls lock module to release its internal structure for this glock. | |
150 | * | |
151 | */ | |
152 | ||
153 | static void glock_free(struct gfs2_glock *gl) | |
154 | { | |
155 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
156 | struct inode *aspace = gl->gl_aspace; | |
157 | ||
b3b94faa DT |
158 | if (aspace) |
159 | gfs2_aspace_put(aspace); | |
63997775 | 160 | trace_gfs2_glock_put(gl); |
f057f6cd | 161 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gfs2_glock_cachep, gl); |
b3b94faa DT |
162 | } |
163 | ||
164 | /** | |
165 | * gfs2_glock_hold() - increment reference count on glock | |
166 | * @gl: The glock to hold | |
167 | * | |
168 | */ | |
169 | ||
048786f1 | 170 | static void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 171 | { |
d8348de0 | 172 | GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
16feb9fe | 173 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
174 | } |
175 | ||
97cc1025 SW |
176 | /** |
177 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
178 | * @gl: the glock | |
179 | * | |
180 | */ | |
181 | ||
182 | static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
183 | { | |
184 | spin_lock(&lru_lock); | |
185 | if (list_empty(&gl->gl_lru) && gl->gl_state != LM_ST_UNLOCKED) { | |
186 | list_add_tail(&gl->gl_lru, &lru_list); | |
187 | atomic_inc(&lru_count); | |
188 | } | |
189 | spin_unlock(&lru_lock); | |
190 | } | |
191 | ||
b3b94faa DT |
192 | /** |
193 | * gfs2_glock_put() - Decrement reference count on glock | |
194 | * @gl: The glock to put | |
195 | * | |
196 | */ | |
197 | ||
198 | int gfs2_glock_put(struct gfs2_glock *gl) | |
199 | { | |
b3b94faa DT |
200 | int rv = 0; |
201 | ||
087efdd3 | 202 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 203 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 204 | hlist_del(&gl->gl_list); |
087efdd3 | 205 | write_unlock(gl_lock_addr(gl->gl_hash)); |
97cc1025 SW |
206 | spin_lock(&lru_lock); |
207 | if (!list_empty(&gl->gl_lru)) { | |
208 | list_del_init(&gl->gl_lru); | |
209 | atomic_dec(&lru_count); | |
210 | } | |
211 | spin_unlock(&lru_lock); | |
6802e340 | 212 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
b3b94faa DT |
213 | glock_free(gl); |
214 | rv = 1; | |
215 | goto out; | |
216 | } | |
97cc1025 SW |
217 | /* 1 for being hashed, 1 for having state != LM_ST_UNLOCKED */ |
218 | if (atomic_read(&gl->gl_ref) == 2) | |
219 | gfs2_glock_schedule_for_reclaim(gl); | |
d8348de0 | 220 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 221 | out: |
b3b94faa DT |
222 | return rv; |
223 | } | |
224 | ||
b3b94faa DT |
225 | /** |
226 | * search_bucket() - Find struct gfs2_glock by lock number | |
227 | * @bucket: the bucket to search | |
228 | * @name: The lock name | |
229 | * | |
230 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
231 | */ | |
232 | ||
37b2fa6a | 233 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 234 | const struct gfs2_sbd *sdp, |
d6a53727 | 235 | const struct lm_lockname *name) |
b3b94faa DT |
236 | { |
237 | struct gfs2_glock *gl; | |
b6397893 | 238 | struct hlist_node *h; |
b3b94faa | 239 | |
b6397893 | 240 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
241 | if (!lm_name_equal(&gl->gl_name, name)) |
242 | continue; | |
899be4d3 SW |
243 | if (gl->gl_sbd != sdp) |
244 | continue; | |
b3b94faa | 245 | |
16feb9fe | 246 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
247 | |
248 | return gl; | |
249 | } | |
250 | ||
251 | return NULL; | |
252 | } | |
253 | ||
6802e340 SW |
254 | /** |
255 | * may_grant - check if its ok to grant a new lock | |
256 | * @gl: The glock | |
257 | * @gh: The lock request which we wish to grant | |
258 | * | |
259 | * Returns: true if its ok to grant the lock | |
260 | */ | |
261 | ||
262 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
263 | { | |
264 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
265 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
266 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
267 | return 0; | |
268 | if (gl->gl_state == gh->gh_state) | |
269 | return 1; | |
270 | if (gh->gh_flags & GL_EXACT) | |
271 | return 0; | |
209806ab SW |
272 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
273 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
274 | return 1; | |
275 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
276 | return 1; | |
277 | } | |
6802e340 SW |
278 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
279 | return 1; | |
280 | return 0; | |
281 | } | |
282 | ||
283 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
284 | { | |
285 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
286 | smp_mb__after_clear_bit(); | |
287 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
288 | } | |
289 | ||
290 | /** | |
291 | * do_promote - promote as many requests as possible on the current queue | |
292 | * @gl: The glock | |
293 | * | |
813e0c46 SW |
294 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
295 | * if a type specific operation is underway. | |
6802e340 SW |
296 | */ |
297 | ||
298 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
299 | __releases(&gl->gl_spin) |
300 | __acquires(&gl->gl_spin) | |
6802e340 SW |
301 | { |
302 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
303 | struct gfs2_holder *gh, *tmp; | |
304 | int ret; | |
305 | ||
306 | restart: | |
307 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
308 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
309 | continue; | |
310 | if (may_grant(gl, gh)) { | |
311 | if (gh->gh_list.prev == &gl->gl_holders && | |
312 | glops->go_lock) { | |
313 | spin_unlock(&gl->gl_spin); | |
314 | /* FIXME: eliminate this eventually */ | |
315 | ret = glops->go_lock(gh); | |
316 | spin_lock(&gl->gl_spin); | |
317 | if (ret) { | |
813e0c46 SW |
318 | if (ret == 1) |
319 | return 2; | |
6802e340 SW |
320 | gh->gh_error = ret; |
321 | list_del_init(&gh->gh_list); | |
63997775 | 322 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
323 | gfs2_holder_wake(gh); |
324 | goto restart; | |
325 | } | |
326 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 327 | trace_gfs2_promote(gh, 1); |
6802e340 SW |
328 | gfs2_holder_wake(gh); |
329 | goto restart; | |
330 | } | |
331 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 332 | trace_gfs2_promote(gh, 0); |
6802e340 SW |
333 | gfs2_holder_wake(gh); |
334 | continue; | |
335 | } | |
336 | if (gh->gh_list.prev == &gl->gl_holders) | |
337 | return 1; | |
338 | break; | |
339 | } | |
340 | return 0; | |
341 | } | |
342 | ||
343 | /** | |
344 | * do_error - Something unexpected has happened during a lock request | |
345 | * | |
346 | */ | |
347 | ||
348 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
349 | { | |
350 | struct gfs2_holder *gh, *tmp; | |
351 | ||
352 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
353 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
354 | continue; | |
355 | if (ret & LM_OUT_ERROR) | |
356 | gh->gh_error = -EIO; | |
357 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
358 | gh->gh_error = GLR_TRYFAILED; | |
359 | else | |
360 | continue; | |
361 | list_del_init(&gh->gh_list); | |
63997775 | 362 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
363 | gfs2_holder_wake(gh); |
364 | } | |
365 | } | |
366 | ||
367 | /** | |
368 | * find_first_waiter - find the first gh that's waiting for the glock | |
369 | * @gl: the glock | |
370 | */ | |
371 | ||
372 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
373 | { | |
374 | struct gfs2_holder *gh; | |
375 | ||
376 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
377 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
378 | return gh; | |
379 | } | |
380 | return NULL; | |
381 | } | |
382 | ||
383 | /** | |
384 | * state_change - record that the glock is now in a different state | |
385 | * @gl: the glock | |
386 | * @new_state the new state | |
387 | * | |
388 | */ | |
389 | ||
390 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
391 | { | |
392 | int held1, held2; | |
393 | ||
394 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
395 | held2 = (new_state != LM_ST_UNLOCKED); | |
396 | ||
397 | if (held1 != held2) { | |
398 | if (held2) | |
399 | gfs2_glock_hold(gl); | |
400 | else | |
401 | gfs2_glock_put(gl); | |
402 | } | |
403 | ||
404 | gl->gl_state = new_state; | |
405 | gl->gl_tchange = jiffies; | |
406 | } | |
407 | ||
408 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
409 | { | |
410 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
411 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
412 | smp_mb__after_clear_bit(); | |
413 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
414 | } | |
415 | ||
416 | /** | |
417 | * finish_xmote - The DLM has replied to one of our lock requests | |
418 | * @gl: The glock | |
419 | * @ret: The status from the DLM | |
420 | * | |
421 | */ | |
422 | ||
423 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
424 | { | |
425 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
426 | struct gfs2_holder *gh; | |
427 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 428 | int rv; |
6802e340 SW |
429 | |
430 | spin_lock(&gl->gl_spin); | |
63997775 | 431 | trace_gfs2_glock_state_change(gl, state); |
6802e340 SW |
432 | state_change(gl, state); |
433 | gh = find_first_waiter(gl); | |
434 | ||
435 | /* Demote to UN request arrived during demote to SH or DF */ | |
436 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
437 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
438 | gl->gl_target = LM_ST_UNLOCKED; | |
439 | ||
440 | /* Check for state != intended state */ | |
441 | if (unlikely(state != gl->gl_target)) { | |
442 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
443 | /* move to back of queue and try next entry */ | |
444 | if (ret & LM_OUT_CANCELED) { | |
445 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
446 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
447 | gh = find_first_waiter(gl); | |
448 | gl->gl_target = gh->gh_state; | |
449 | goto retry; | |
450 | } | |
451 | /* Some error or failed "try lock" - report it */ | |
452 | if ((ret & LM_OUT_ERROR) || | |
453 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
454 | gl->gl_target = gl->gl_state; | |
455 | do_error(gl, ret); | |
456 | goto out; | |
457 | } | |
458 | } | |
459 | switch(state) { | |
460 | /* Unlocked due to conversion deadlock, try again */ | |
461 | case LM_ST_UNLOCKED: | |
462 | retry: | |
463 | do_xmote(gl, gh, gl->gl_target); | |
464 | break; | |
465 | /* Conversion fails, unlock and try again */ | |
466 | case LM_ST_SHARED: | |
467 | case LM_ST_DEFERRED: | |
468 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
469 | break; | |
470 | default: /* Everything else */ | |
471 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
472 | GLOCK_BUG_ON(gl, 1); | |
473 | } | |
474 | spin_unlock(&gl->gl_spin); | |
475 | gfs2_glock_put(gl); | |
476 | return; | |
477 | } | |
478 | ||
479 | /* Fast path - we got what we asked for */ | |
480 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
481 | gfs2_demote_wake(gl); | |
482 | if (state != LM_ST_UNLOCKED) { | |
483 | if (glops->go_xmote_bh) { | |
6802e340 SW |
484 | spin_unlock(&gl->gl_spin); |
485 | rv = glops->go_xmote_bh(gl, gh); | |
486 | if (rv == -EAGAIN) | |
487 | return; | |
488 | spin_lock(&gl->gl_spin); | |
489 | if (rv) { | |
490 | do_error(gl, rv); | |
491 | goto out; | |
492 | } | |
493 | } | |
813e0c46 SW |
494 | rv = do_promote(gl); |
495 | if (rv == 2) | |
496 | goto out_locked; | |
6802e340 SW |
497 | } |
498 | out: | |
499 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 500 | out_locked: |
6802e340 SW |
501 | spin_unlock(&gl->gl_spin); |
502 | gfs2_glock_put(gl); | |
503 | } | |
504 | ||
505 | static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, | |
f057f6cd | 506 | unsigned int req_state, |
6802e340 SW |
507 | unsigned int flags) |
508 | { | |
509 | int ret = LM_OUT_ERROR; | |
048bca22 SW |
510 | |
511 | if (!sdp->sd_lockstruct.ls_ops->lm_lock) | |
512 | return req_state == LM_ST_UNLOCKED ? 0 : req_state; | |
513 | ||
6802e340 | 514 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
f057f6cd | 515 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, |
6802e340 SW |
516 | req_state, flags); |
517 | return ret; | |
518 | } | |
519 | ||
520 | /** | |
521 | * do_xmote - Calls the DLM to change the state of a lock | |
522 | * @gl: The lock state | |
523 | * @gh: The holder (only for promotes) | |
524 | * @target: The target lock state | |
525 | * | |
526 | */ | |
527 | ||
528 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
529 | __releases(&gl->gl_spin) |
530 | __acquires(&gl->gl_spin) | |
6802e340 SW |
531 | { |
532 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
533 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
534 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
535 | int ret; | |
536 | ||
537 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
538 | LM_FLAG_PRIORITY); | |
539 | BUG_ON(gl->gl_state == target); | |
540 | BUG_ON(gl->gl_state == gl->gl_target); | |
541 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
542 | glops->go_inval) { | |
543 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
544 | do_error(gl, 0); /* Fail queued try locks */ | |
545 | } | |
546 | spin_unlock(&gl->gl_spin); | |
547 | if (glops->go_xmote_th) | |
548 | glops->go_xmote_th(gl); | |
549 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
550 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
551 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
552 | ||
553 | gfs2_glock_hold(gl); | |
554 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
555 | gl->gl_state == LM_ST_DEFERRED) && | |
556 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
557 | lck_flags |= LM_FLAG_TRY_1CB; | |
f057f6cd | 558 | ret = gfs2_lm_lock(sdp, gl, target, lck_flags); |
6802e340 SW |
559 | |
560 | if (!(ret & LM_OUT_ASYNC)) { | |
561 | finish_xmote(gl, ret); | |
562 | gfs2_glock_hold(gl); | |
563 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
564 | gfs2_glock_put(gl); | |
565 | } else { | |
566 | GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); | |
567 | } | |
568 | spin_lock(&gl->gl_spin); | |
569 | } | |
570 | ||
571 | /** | |
572 | * find_first_holder - find the first "holder" gh | |
573 | * @gl: the glock | |
574 | */ | |
575 | ||
576 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
577 | { | |
578 | struct gfs2_holder *gh; | |
579 | ||
580 | if (!list_empty(&gl->gl_holders)) { | |
581 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
582 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
583 | return gh; | |
584 | } | |
585 | return NULL; | |
586 | } | |
587 | ||
588 | /** | |
589 | * run_queue - do all outstanding tasks related to a glock | |
590 | * @gl: The glock in question | |
591 | * @nonblock: True if we must not block in run_queue | |
592 | * | |
593 | */ | |
594 | ||
595 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
596 | __releases(&gl->gl_spin) |
597 | __acquires(&gl->gl_spin) | |
6802e340 SW |
598 | { |
599 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 600 | int ret; |
6802e340 SW |
601 | |
602 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
603 | return; | |
604 | ||
605 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
606 | ||
607 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
608 | gl->gl_demote_state != gl->gl_state) { | |
609 | if (find_first_holder(gl)) | |
d8348de0 | 610 | goto out_unlock; |
6802e340 SW |
611 | if (nonblock) |
612 | goto out_sched; | |
613 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 614 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
615 | gl->gl_target = gl->gl_demote_state; |
616 | } else { | |
617 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
618 | gfs2_demote_wake(gl); | |
813e0c46 SW |
619 | ret = do_promote(gl); |
620 | if (ret == 0) | |
d8348de0 | 621 | goto out_unlock; |
813e0c46 | 622 | if (ret == 2) |
a228df63 | 623 | goto out; |
6802e340 SW |
624 | gh = find_first_waiter(gl); |
625 | gl->gl_target = gh->gh_state; | |
626 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
627 | do_error(gl, 0); /* Fail queued try locks */ | |
628 | } | |
629 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 630 | out: |
6802e340 SW |
631 | return; |
632 | ||
633 | out_sched: | |
634 | gfs2_glock_hold(gl); | |
635 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
636 | gfs2_glock_put(gl); | |
d8348de0 | 637 | out_unlock: |
6802e340 | 638 | clear_bit(GLF_LOCK, &gl->gl_flags); |
a228df63 | 639 | goto out; |
6802e340 SW |
640 | } |
641 | ||
c4f68a13 BM |
642 | static void glock_work_func(struct work_struct *work) |
643 | { | |
6802e340 | 644 | unsigned long delay = 0; |
c4f68a13 BM |
645 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
646 | ||
6802e340 SW |
647 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
648 | finish_xmote(gl, gl->gl_reply); | |
a228df63 | 649 | down_read(&gfs2_umount_flush_sem); |
c4f68a13 | 650 | spin_lock(&gl->gl_spin); |
265d529c SW |
651 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
652 | gl->gl_state != LM_ST_UNLOCKED && | |
653 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
654 | unsigned long holdtime, now = jiffies; |
655 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
656 | if (time_before(now, holdtime)) | |
657 | delay = holdtime - now; | |
658 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
659 | } | |
660 | run_queue(gl, 0); | |
c4f68a13 | 661 | spin_unlock(&gl->gl_spin); |
a228df63 | 662 | up_read(&gfs2_umount_flush_sem); |
6802e340 SW |
663 | if (!delay || |
664 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
665 | gfs2_glock_put(gl); | |
c4f68a13 BM |
666 | } |
667 | ||
b3b94faa DT |
668 | /** |
669 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
670 | * @sdp: The GFS2 superblock | |
671 | * @number: the lock number | |
672 | * @glops: The glock_operations to use | |
673 | * @create: If 0, don't create the glock if it doesn't exist | |
674 | * @glp: the glock is returned here | |
675 | * | |
676 | * This does not lock a glock, just finds/creates structures for one. | |
677 | * | |
678 | * Returns: errno | |
679 | */ | |
680 | ||
cd915493 | 681 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 682 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
683 | struct gfs2_glock **glp) |
684 | { | |
37b2fa6a | 685 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 686 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 687 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
688 | int error; |
689 | ||
087efdd3 | 690 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 691 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 692 | read_unlock(gl_lock_addr(hash)); |
b3b94faa | 693 | |
64d576ba SW |
694 | *glp = gl; |
695 | if (gl) | |
b3b94faa | 696 | return 0; |
64d576ba SW |
697 | if (!create) |
698 | return -ENOENT; | |
b3b94faa DT |
699 | |
700 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
701 | if (!gl) | |
702 | return -ENOMEM; | |
703 | ||
ec45d9f5 | 704 | gl->gl_flags = 0; |
b3b94faa | 705 | gl->gl_name = name; |
16feb9fe | 706 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 707 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 708 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 709 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 710 | gl->gl_hash = hash; |
b3b94faa | 711 | gl->gl_ops = glops; |
f057f6cd SW |
712 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
713 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
714 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 715 | gl->gl_tchange = jiffies; |
ec45d9f5 | 716 | gl->gl_object = NULL; |
b3b94faa | 717 | gl->gl_sbd = sdp; |
ec45d9f5 | 718 | gl->gl_aspace = NULL; |
c4f68a13 | 719 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b3b94faa DT |
720 | |
721 | /* If this glock protects actual on-disk data or metadata blocks, | |
722 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 723 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
724 | gl->gl_aspace = gfs2_aspace_get(sdp); |
725 | if (!gl->gl_aspace) { | |
726 | error = -ENOMEM; | |
727 | goto fail; | |
728 | } | |
729 | } | |
730 | ||
087efdd3 | 731 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 732 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 733 | if (tmp) { |
087efdd3 | 734 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
735 | glock_free(gl); |
736 | gl = tmp; | |
737 | } else { | |
b6397893 | 738 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 739 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
740 | } |
741 | ||
742 | *glp = gl; | |
743 | ||
744 | return 0; | |
745 | ||
ec45d9f5 | 746 | fail: |
907b9bce | 747 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
748 | return error; |
749 | } | |
750 | ||
751 | /** | |
752 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
753 | * @gl: the glock | |
754 | * @state: the state we're requesting | |
755 | * @flags: the modifier flags | |
756 | * @gh: the holder structure | |
757 | * | |
758 | */ | |
759 | ||
190562bd | 760 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
761 | struct gfs2_holder *gh) |
762 | { | |
763 | INIT_LIST_HEAD(&gh->gh_list); | |
764 | gh->gh_gl = gl; | |
d0dc80db | 765 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 766 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
767 | gh->gh_state = state; |
768 | gh->gh_flags = flags; | |
769 | gh->gh_error = 0; | |
770 | gh->gh_iflags = 0; | |
b3b94faa DT |
771 | gfs2_glock_hold(gl); |
772 | } | |
773 | ||
774 | /** | |
775 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
776 | * @state: the state we're requesting | |
777 | * @flags: the modifier flags | |
778 | * @gh: the holder structure | |
779 | * | |
780 | * Don't mess with the glock. | |
781 | * | |
782 | */ | |
783 | ||
190562bd | 784 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
785 | { |
786 | gh->gh_state = state; | |
579b78a4 | 787 | gh->gh_flags = flags; |
3b8249f6 | 788 | gh->gh_iflags = 0; |
d0dc80db | 789 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
790 | } |
791 | ||
792 | /** | |
793 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
794 | * @gh: the holder structure | |
795 | * | |
796 | */ | |
797 | ||
798 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
799 | { | |
b1e058da | 800 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
801 | gfs2_glock_put(gh->gh_gl); |
802 | gh->gh_gl = NULL; | |
d0dc80db | 803 | gh->gh_ip = 0; |
b3b94faa DT |
804 | } |
805 | ||
fe64d517 SW |
806 | /** |
807 | * gfs2_glock_holder_wait | |
808 | * @word: unused | |
809 | * | |
810 | * This function and gfs2_glock_demote_wait both show up in the WCHAN | |
811 | * field. Thus I've separated these otherwise identical functions in | |
812 | * order to be more informative to the user. | |
813 | */ | |
814 | ||
815 | static int gfs2_glock_holder_wait(void *word) | |
fee852e3 SW |
816 | { |
817 | schedule(); | |
818 | return 0; | |
819 | } | |
820 | ||
fe64d517 SW |
821 | static int gfs2_glock_demote_wait(void *word) |
822 | { | |
823 | schedule(); | |
824 | return 0; | |
825 | } | |
826 | ||
6802e340 | 827 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 828 | { |
6802e340 | 829 | might_sleep(); |
fe64d517 | 830 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
da755fdb SW |
831 | } |
832 | ||
6802e340 | 833 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 834 | { |
6802e340 | 835 | might_sleep(); |
fe64d517 | 836 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
b3b94faa DT |
837 | } |
838 | ||
839 | /** | |
6802e340 SW |
840 | * handle_callback - process a demote request |
841 | * @gl: the glock | |
842 | * @state: the state the caller wants us to change to | |
b3b94faa | 843 | * |
6802e340 SW |
844 | * There are only two requests that we are going to see in actual |
845 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
846 | */ |
847 | ||
6802e340 | 848 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 849 | unsigned long delay) |
b3b94faa | 850 | { |
6802e340 | 851 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 852 | |
6802e340 SW |
853 | set_bit(bit, &gl->gl_flags); |
854 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
855 | gl->gl_demote_state = state; | |
856 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
857 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
858 | gl->gl_demote_state != state) { | |
859 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 860 | } |
63997775 | 861 | trace_gfs2_demote_rq(gl); |
b3b94faa DT |
862 | } |
863 | ||
864 | /** | |
6802e340 | 865 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
866 | * @gh: the glock holder |
867 | * | |
868 | * Returns: 0 on success | |
869 | */ | |
870 | ||
6802e340 | 871 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 872 | { |
fee852e3 | 873 | wait_on_holder(gh); |
b3b94faa DT |
874 | return gh->gh_error; |
875 | } | |
876 | ||
6802e340 | 877 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 RP |
878 | { |
879 | va_list args; | |
880 | ||
881 | va_start(args, fmt); | |
6802e340 SW |
882 | if (seq) { |
883 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 884 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
885 | seq_printf(seq, gi->string); |
886 | } else { | |
887 | printk(KERN_ERR " "); | |
7c52b166 | 888 | vprintk(fmt, args); |
6802e340 | 889 | } |
7c52b166 RP |
890 | va_end(args); |
891 | } | |
892 | ||
b3b94faa DT |
893 | /** |
894 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
895 | * @gh: the holder structure to add | |
896 | * | |
6802e340 SW |
897 | * Eventually we should move the recursive locking trap to a |
898 | * debugging option or something like that. This is the fast | |
899 | * path and needs to have the minimum number of distractions. | |
900 | * | |
b3b94faa DT |
901 | */ |
902 | ||
6802e340 | 903 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
904 | __releases(&gl->gl_spin) |
905 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
906 | { |
907 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
908 | struct gfs2_sbd *sdp = gl->gl_sbd; |
909 | struct list_head *insert_pt = NULL; | |
910 | struct gfs2_holder *gh2; | |
911 | int try_lock = 0; | |
b3b94faa | 912 | |
b1e058da | 913 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
914 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
915 | BUG(); | |
190562bd | 916 | |
6802e340 SW |
917 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
918 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
919 | try_lock = 1; | |
920 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
921 | goto fail; | |
922 | } | |
923 | ||
924 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
925 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
926 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
927 | goto trap_recursive; | |
928 | if (try_lock && | |
929 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
930 | !may_grant(gl, gh)) { | |
931 | fail: | |
932 | gh->gh_error = GLR_TRYFAILED; | |
933 | gfs2_holder_wake(gh); | |
934 | return; | |
b4c20166 | 935 | } |
6802e340 SW |
936 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
937 | continue; | |
938 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
939 | insert_pt = &gh2->gh_list; | |
940 | } | |
941 | if (likely(insert_pt == NULL)) { | |
942 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
943 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
944 | goto do_cancel; | |
945 | return; | |
946 | } | |
63997775 | 947 | trace_gfs2_glock_queue(gh, 1); |
6802e340 SW |
948 | list_add_tail(&gh->gh_list, insert_pt); |
949 | do_cancel: | |
950 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
951 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
952 | spin_unlock(&gl->gl_spin); | |
048bca22 | 953 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 954 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 955 | spin_lock(&gl->gl_spin); |
b3b94faa | 956 | } |
6802e340 | 957 | return; |
b3b94faa | 958 | |
6802e340 SW |
959 | trap_recursive: |
960 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
961 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
962 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
963 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
964 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
965 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
966 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
967 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
968 | __dump_glock(NULL, gl); | |
969 | BUG(); | |
b3b94faa DT |
970 | } |
971 | ||
972 | /** | |
973 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
974 | * @gh: the holder structure | |
975 | * | |
976 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
977 | * | |
978 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
979 | */ | |
980 | ||
981 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
982 | { | |
983 | struct gfs2_glock *gl = gh->gh_gl; | |
984 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
985 | int error = 0; | |
986 | ||
6802e340 | 987 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 988 | return -EIO; |
b3b94faa | 989 | |
b3b94faa DT |
990 | spin_lock(&gl->gl_spin); |
991 | add_to_queue(gh); | |
6802e340 | 992 | run_queue(gl, 1); |
b3b94faa DT |
993 | spin_unlock(&gl->gl_spin); |
994 | ||
6802e340 SW |
995 | if (!(gh->gh_flags & GL_ASYNC)) |
996 | error = gfs2_glock_wait(gh); | |
b3b94faa | 997 | |
b3b94faa DT |
998 | return error; |
999 | } | |
1000 | ||
1001 | /** | |
1002 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1003 | * @gh: the holder | |
1004 | * | |
1005 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1006 | */ | |
1007 | ||
1008 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1009 | { | |
6802e340 | 1010 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1011 | } |
1012 | ||
1013 | /** | |
1014 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1015 | * @gh: the glock holder | |
1016 | * | |
1017 | */ | |
1018 | ||
1019 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1020 | { | |
1021 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1022 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1023 | unsigned delay = 0; |
6802e340 | 1024 | int fast_path = 0; |
b3b94faa | 1025 | |
6802e340 | 1026 | spin_lock(&gl->gl_spin); |
b3b94faa | 1027 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1028 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1029 | |
b3b94faa | 1030 | list_del_init(&gh->gh_list); |
6802e340 | 1031 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1032 | if (glops->go_unlock) { |
6802e340 | 1033 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1034 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1035 | glops->go_unlock(gh); |
3042a2cc | 1036 | spin_lock(&gl->gl_spin); |
6802e340 | 1037 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1038 | } |
6802e340 SW |
1039 | if (list_empty(&gl->gl_holders) && |
1040 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1041 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1042 | fast_path = 1; | |
b3b94faa | 1043 | } |
63997775 | 1044 | trace_gfs2_glock_queue(gh, 0); |
b3b94faa | 1045 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1046 | if (likely(fast_path)) |
1047 | return; | |
c4f68a13 BM |
1048 | |
1049 | gfs2_glock_hold(gl); | |
1050 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1051 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1052 | delay = gl->gl_ops->go_min_hold_time; | |
1053 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1054 | gfs2_glock_put(gl); | |
b3b94faa DT |
1055 | } |
1056 | ||
d93cfa98 AD |
1057 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1058 | { | |
1059 | struct gfs2_glock *gl = gh->gh_gl; | |
1060 | gfs2_glock_dq(gh); | |
1061 | wait_on_demote(gl); | |
1062 | } | |
1063 | ||
b3b94faa DT |
1064 | /** |
1065 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1066 | * @gh: the holder structure | |
1067 | * | |
1068 | */ | |
1069 | ||
1070 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1071 | { | |
1072 | gfs2_glock_dq(gh); | |
1073 | gfs2_holder_uninit(gh); | |
1074 | } | |
1075 | ||
1076 | /** | |
1077 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1078 | * @sdp: the filesystem | |
1079 | * @number: the lock number | |
1080 | * @glops: the glock operations for the type of glock | |
1081 | * @state: the state to acquire the glock in | |
1082 | * @flags: modifier flags for the aquisition | |
1083 | * @gh: the struct gfs2_holder | |
1084 | * | |
1085 | * Returns: errno | |
1086 | */ | |
1087 | ||
cd915493 | 1088 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1089 | const struct gfs2_glock_operations *glops, |
1090 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1091 | { |
1092 | struct gfs2_glock *gl; | |
1093 | int error; | |
1094 | ||
1095 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1096 | if (!error) { | |
1097 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1098 | gfs2_glock_put(gl); | |
1099 | } | |
1100 | ||
1101 | return error; | |
1102 | } | |
1103 | ||
1104 | /** | |
1105 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1106 | * @arg_a: the first structure | |
1107 | * @arg_b: the second structure | |
1108 | * | |
1109 | */ | |
1110 | ||
1111 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1112 | { | |
a5e08a9e SW |
1113 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1114 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1115 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1116 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1117 | |
1118 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1119 | return 1; |
1120 | if (a->ln_number < b->ln_number) | |
1121 | return -1; | |
1c0f4872 | 1122 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1123 | return 0; |
b3b94faa DT |
1124 | } |
1125 | ||
1126 | /** | |
1127 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1128 | * @num_gh: the number of structures | |
1129 | * @ghs: an array of struct gfs2_holder structures | |
1130 | * | |
1131 | * Returns: 0 on success (all glocks acquired), | |
1132 | * errno on failure (no glocks acquired) | |
1133 | */ | |
1134 | ||
1135 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1136 | struct gfs2_holder **p) | |
1137 | { | |
1138 | unsigned int x; | |
1139 | int error = 0; | |
1140 | ||
1141 | for (x = 0; x < num_gh; x++) | |
1142 | p[x] = &ghs[x]; | |
1143 | ||
1144 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1145 | ||
1146 | for (x = 0; x < num_gh; x++) { | |
1147 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1148 | ||
1149 | error = gfs2_glock_nq(p[x]); | |
1150 | if (error) { | |
1151 | while (x--) | |
1152 | gfs2_glock_dq(p[x]); | |
1153 | break; | |
1154 | } | |
1155 | } | |
1156 | ||
1157 | return error; | |
1158 | } | |
1159 | ||
1160 | /** | |
1161 | * gfs2_glock_nq_m - acquire multiple glocks | |
1162 | * @num_gh: the number of structures | |
1163 | * @ghs: an array of struct gfs2_holder structures | |
1164 | * | |
b3b94faa DT |
1165 | * |
1166 | * Returns: 0 on success (all glocks acquired), | |
1167 | * errno on failure (no glocks acquired) | |
1168 | */ | |
1169 | ||
1170 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1171 | { | |
eaf5bd3c SW |
1172 | struct gfs2_holder *tmp[4]; |
1173 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1174 | int error = 0; |
1175 | ||
eaf5bd3c SW |
1176 | switch(num_gh) { |
1177 | case 0: | |
b3b94faa | 1178 | return 0; |
eaf5bd3c | 1179 | case 1: |
b3b94faa DT |
1180 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1181 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1182 | default: |
1183 | if (num_gh <= 4) | |
b3b94faa | 1184 | break; |
eaf5bd3c SW |
1185 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1186 | if (!pph) | |
1187 | return -ENOMEM; | |
b3b94faa DT |
1188 | } |
1189 | ||
eaf5bd3c | 1190 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1191 | |
eaf5bd3c SW |
1192 | if (pph != tmp) |
1193 | kfree(pph); | |
b3b94faa DT |
1194 | |
1195 | return error; | |
1196 | } | |
1197 | ||
1198 | /** | |
1199 | * gfs2_glock_dq_m - release multiple glocks | |
1200 | * @num_gh: the number of structures | |
1201 | * @ghs: an array of struct gfs2_holder structures | |
1202 | * | |
1203 | */ | |
1204 | ||
1205 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1206 | { | |
1207 | unsigned int x; | |
1208 | ||
1209 | for (x = 0; x < num_gh; x++) | |
1210 | gfs2_glock_dq(&ghs[x]); | |
1211 | } | |
1212 | ||
1213 | /** | |
1214 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1215 | * @num_gh: the number of structures | |
1216 | * @ghs: an array of struct gfs2_holder structures | |
1217 | * | |
1218 | */ | |
1219 | ||
1220 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1221 | { | |
1222 | unsigned int x; | |
1223 | ||
1224 | for (x = 0; x < num_gh; x++) | |
1225 | gfs2_glock_dq_uninit(&ghs[x]); | |
1226 | } | |
1227 | ||
f057f6cd | 1228 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1229 | { |
c4f68a13 BM |
1230 | unsigned long delay = 0; |
1231 | unsigned long holdtime; | |
1232 | unsigned long now = jiffies; | |
b3b94faa | 1233 | |
f057f6cd | 1234 | gfs2_glock_hold(gl); |
c4f68a13 BM |
1235 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1236 | if (time_before(now, holdtime)) | |
1237 | delay = holdtime - now; | |
dff52574 SW |
1238 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
1239 | delay = gl->gl_ops->go_min_hold_time; | |
b3b94faa | 1240 | |
6802e340 | 1241 | spin_lock(&gl->gl_spin); |
97cc1025 | 1242 | handle_callback(gl, state, delay); |
6802e340 | 1243 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1244 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1245 | gfs2_glock_put(gl); | |
b3b94faa DT |
1246 | } |
1247 | ||
1248 | /** | |
f057f6cd SW |
1249 | * gfs2_glock_complete - Callback used by locking |
1250 | * @gl: Pointer to the glock | |
1251 | * @ret: The return value from the dlm | |
b3b94faa | 1252 | * |
b3b94faa DT |
1253 | */ |
1254 | ||
f057f6cd | 1255 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1256 | { |
f057f6cd | 1257 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
f057f6cd SW |
1258 | gl->gl_reply = ret; |
1259 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) { | |
1260 | struct gfs2_holder *gh; | |
1261 | spin_lock(&gl->gl_spin); | |
1262 | gh = find_first_waiter(gl); | |
1263 | if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) && | |
1264 | (gl->gl_target != LM_ST_UNLOCKED)) || | |
1265 | ((ret & ~LM_OUT_ST_MASK) != 0)) | |
1266 | set_bit(GLF_FROZEN, &gl->gl_flags); | |
1267 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 1268 | if (test_bit(GLF_FROZEN, &gl->gl_flags)) |
b3b94faa | 1269 | return; |
b3b94faa | 1270 | } |
f057f6cd SW |
1271 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1272 | gfs2_glock_hold(gl); | |
1273 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1274 | gfs2_glock_put(gl); | |
b3b94faa DT |
1275 | } |
1276 | ||
b3b94faa DT |
1277 | /** |
1278 | * demote_ok - Check to see if it's ok to unlock a glock | |
1279 | * @gl: the glock | |
1280 | * | |
1281 | * Returns: 1 if it's ok | |
1282 | */ | |
1283 | ||
97cc1025 | 1284 | static int demote_ok(const struct gfs2_glock *gl) |
b3b94faa | 1285 | { |
8fb4b536 | 1286 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa | 1287 | |
97cc1025 SW |
1288 | if (gl->gl_state == LM_ST_UNLOCKED) |
1289 | return 0; | |
1290 | if (!list_empty(&gl->gl_holders)) | |
1291 | return 0; | |
1292 | if (glops->go_demote_ok) | |
1293 | return glops->go_demote_ok(gl); | |
1294 | return 1; | |
b3b94faa DT |
1295 | } |
1296 | ||
b3b94faa | 1297 | |
97cc1025 | 1298 | static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask) |
b3b94faa DT |
1299 | { |
1300 | struct gfs2_glock *gl; | |
97cc1025 SW |
1301 | int may_demote; |
1302 | int nr_skipped = 0; | |
1303 | int got_ref = 0; | |
1304 | LIST_HEAD(skipped); | |
b3b94faa | 1305 | |
97cc1025 SW |
1306 | if (nr == 0) |
1307 | goto out; | |
b3b94faa | 1308 | |
97cc1025 SW |
1309 | if (!(gfp_mask & __GFP_FS)) |
1310 | return -1; | |
b3b94faa | 1311 | |
97cc1025 SW |
1312 | spin_lock(&lru_lock); |
1313 | while(nr && !list_empty(&lru_list)) { | |
1314 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1315 | list_del_init(&gl->gl_lru); | |
1316 | atomic_dec(&lru_count); | |
1317 | ||
1318 | /* Test for being demotable */ | |
1319 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1320 | gfs2_glock_hold(gl); | |
1321 | got_ref = 1; | |
1322 | spin_unlock(&lru_lock); | |
1323 | spin_lock(&gl->gl_spin); | |
1324 | may_demote = demote_ok(gl); | |
1325 | spin_unlock(&gl->gl_spin); | |
1326 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1327 | if (may_demote) { | |
1328 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1329 | nr--; | |
1330 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1331 | gfs2_glock_put(gl); | |
0c7a531a | 1332 | got_ref = 0; |
97cc1025 SW |
1333 | } |
1334 | spin_lock(&lru_lock); | |
1335 | if (may_demote) | |
1336 | continue; | |
1337 | } | |
1338 | if (list_empty(&gl->gl_lru) && | |
1339 | (atomic_read(&gl->gl_ref) <= (2 + got_ref))) { | |
1340 | nr_skipped++; | |
1341 | list_add(&gl->gl_lru, &skipped); | |
1342 | } | |
1343 | if (got_ref) { | |
1344 | spin_unlock(&lru_lock); | |
1345 | gfs2_glock_put(gl); | |
1346 | spin_lock(&lru_lock); | |
1347 | got_ref = 0; | |
1348 | } | |
b3b94faa | 1349 | } |
97cc1025 SW |
1350 | list_splice(&skipped, &lru_list); |
1351 | atomic_add(nr_skipped, &lru_count); | |
1352 | spin_unlock(&lru_lock); | |
1353 | out: | |
1354 | return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure; | |
b3b94faa DT |
1355 | } |
1356 | ||
97cc1025 SW |
1357 | static struct shrinker glock_shrinker = { |
1358 | .shrink = gfs2_shrink_glock_memory, | |
1359 | .seeks = DEFAULT_SEEKS, | |
1360 | }; | |
1361 | ||
b3b94faa DT |
1362 | /** |
1363 | * examine_bucket - Call a function for glock in a hash bucket | |
1364 | * @examiner: the function | |
1365 | * @sdp: the filesystem | |
1366 | * @bucket: the bucket | |
1367 | * | |
1368 | * Returns: 1 if the bucket has entries | |
1369 | */ | |
1370 | ||
1371 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1372 | unsigned int hash) |
b3b94faa | 1373 | { |
24264434 SW |
1374 | struct gfs2_glock *gl, *prev = NULL; |
1375 | int has_entries = 0; | |
b6397893 | 1376 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1377 | |
24264434 | 1378 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1379 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1380 | if (hlist_empty(head)) | |
24264434 | 1381 | goto out; |
b6397893 SW |
1382 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1383 | while(1) { | |
8fbbfd21 | 1384 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1385 | gfs2_glock_hold(gl); |
24264434 SW |
1386 | read_unlock(gl_lock_addr(hash)); |
1387 | if (prev) | |
1388 | gfs2_glock_put(prev); | |
1389 | prev = gl; | |
1390 | examiner(gl); | |
a8336344 | 1391 | has_entries = 1; |
24264434 | 1392 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1393 | } |
b6397893 SW |
1394 | if (gl->gl_list.next == NULL) |
1395 | break; | |
24264434 | 1396 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1397 | } |
24264434 SW |
1398 | out: |
1399 | read_unlock(gl_lock_addr(hash)); | |
1400 | if (prev) | |
1401 | gfs2_glock_put(prev); | |
8fbbfd21 | 1402 | cond_resched(); |
24264434 | 1403 | return has_entries; |
b3b94faa DT |
1404 | } |
1405 | ||
f057f6cd SW |
1406 | |
1407 | /** | |
1408 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1409 | * @gl: The glock to thaw | |
1410 | * | |
1411 | * N.B. When we freeze a glock, we leave a ref to the glock outstanding, | |
1412 | * so this has to result in the ref count being dropped by one. | |
1413 | */ | |
1414 | ||
1415 | static void thaw_glock(struct gfs2_glock *gl) | |
1416 | { | |
1417 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1418 | return; | |
f057f6cd SW |
1419 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1420 | gfs2_glock_hold(gl); | |
1421 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1422 | gfs2_glock_put(gl); | |
f057f6cd SW |
1423 | } |
1424 | ||
b3b94faa DT |
1425 | /** |
1426 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1427 | * @gl: the glock to look at | |
1428 | * | |
1429 | */ | |
1430 | ||
1431 | static void clear_glock(struct gfs2_glock *gl) | |
1432 | { | |
97cc1025 SW |
1433 | spin_lock(&lru_lock); |
1434 | if (!list_empty(&gl->gl_lru)) { | |
1435 | list_del_init(&gl->gl_lru); | |
1436 | atomic_dec(&lru_count); | |
b3b94faa | 1437 | } |
97cc1025 | 1438 | spin_unlock(&lru_lock); |
b3b94faa | 1439 | |
6802e340 SW |
1440 | spin_lock(&gl->gl_spin); |
1441 | if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED) | |
97cc1025 | 1442 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
6802e340 SW |
1443 | spin_unlock(&gl->gl_spin); |
1444 | gfs2_glock_hold(gl); | |
1445 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1446 | gfs2_glock_put(gl); | |
b3b94faa DT |
1447 | } |
1448 | ||
f057f6cd SW |
1449 | /** |
1450 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1451 | * @sdp: The super block | |
1452 | * | |
1453 | */ | |
1454 | ||
1455 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1456 | { | |
1457 | unsigned x; | |
1458 | ||
1459 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1460 | examine_bucket(thaw_glock, sdp, x); | |
1461 | } | |
1462 | ||
b3b94faa DT |
1463 | /** |
1464 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1465 | * @sdp: the filesystem | |
1466 | * @wait: wait until it's all gone | |
1467 | * | |
1bdad606 | 1468 | * Called when unmounting the filesystem. |
b3b94faa DT |
1469 | */ |
1470 | ||
fefc03bf | 1471 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa DT |
1472 | { |
1473 | unsigned long t; | |
1474 | unsigned int x; | |
1475 | int cont; | |
1476 | ||
1477 | t = jiffies; | |
1478 | ||
1479 | for (;;) { | |
1480 | cont = 0; | |
24264434 | 1481 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1482 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1483 | cont = 1; |
24264434 | 1484 | } |
b3b94faa | 1485 | |
1bdad606 | 1486 | if (!cont) |
b3b94faa DT |
1487 | break; |
1488 | ||
1489 | if (time_after_eq(jiffies, | |
1490 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1491 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1492 | "Dumping lock state...\n"); | |
1493 | gfs2_dump_lockstate(sdp); | |
1494 | t = jiffies; | |
1495 | } | |
1496 | ||
61be084e | 1497 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1498 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1499 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1500 | msleep(10); |
b3b94faa DT |
1501 | } |
1502 | } | |
1503 | ||
813e0c46 SW |
1504 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1505 | { | |
1506 | struct gfs2_glock *gl = ip->i_gl; | |
1507 | int ret; | |
1508 | ||
1509 | ret = gfs2_truncatei_resume(ip); | |
1510 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1511 | ||
1512 | spin_lock(&gl->gl_spin); | |
1513 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1514 | run_queue(gl, 1); | |
1515 | spin_unlock(&gl->gl_spin); | |
1516 | } | |
1517 | ||
6802e340 | 1518 | static const char *state2str(unsigned state) |
04b933f2 | 1519 | { |
6802e340 SW |
1520 | switch(state) { |
1521 | case LM_ST_UNLOCKED: | |
1522 | return "UN"; | |
1523 | case LM_ST_SHARED: | |
1524 | return "SH"; | |
1525 | case LM_ST_DEFERRED: | |
1526 | return "DF"; | |
1527 | case LM_ST_EXCLUSIVE: | |
1528 | return "EX"; | |
1529 | } | |
1530 | return "??"; | |
1531 | } | |
1532 | ||
1533 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1534 | { | |
1535 | char *p = buf; | |
1536 | if (flags & LM_FLAG_TRY) | |
1537 | *p++ = 't'; | |
1538 | if (flags & LM_FLAG_TRY_1CB) | |
1539 | *p++ = 'T'; | |
1540 | if (flags & LM_FLAG_NOEXP) | |
1541 | *p++ = 'e'; | |
1542 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1543 | *p++ = 'A'; |
6802e340 SW |
1544 | if (flags & LM_FLAG_PRIORITY) |
1545 | *p++ = 'p'; | |
1546 | if (flags & GL_ASYNC) | |
1547 | *p++ = 'a'; | |
1548 | if (flags & GL_EXACT) | |
1549 | *p++ = 'E'; | |
6802e340 SW |
1550 | if (flags & GL_NOCACHE) |
1551 | *p++ = 'c'; | |
1552 | if (test_bit(HIF_HOLDER, &iflags)) | |
1553 | *p++ = 'H'; | |
1554 | if (test_bit(HIF_WAIT, &iflags)) | |
1555 | *p++ = 'W'; | |
1556 | if (test_bit(HIF_FIRST, &iflags)) | |
1557 | *p++ = 'F'; | |
1558 | *p = 0; | |
1559 | return buf; | |
04b933f2 RP |
1560 | } |
1561 | ||
b3b94faa DT |
1562 | /** |
1563 | * dump_holder - print information about a glock holder | |
6802e340 | 1564 | * @seq: the seq_file struct |
b3b94faa DT |
1565 | * @gh: the glock holder |
1566 | * | |
1567 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1568 | */ | |
1569 | ||
6802e340 | 1570 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1571 | { |
6802e340 SW |
1572 | struct task_struct *gh_owner = NULL; |
1573 | char buffer[KSYM_SYMBOL_LEN]; | |
1574 | char flags_buf[32]; | |
b3b94faa | 1575 | |
6802e340 SW |
1576 | sprint_symbol(buffer, gh->gh_ip); |
1577 | if (gh->gh_owner_pid) | |
b1e058da | 1578 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
6802e340 SW |
1579 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", |
1580 | state2str(gh->gh_state), | |
1581 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1582 | gh->gh_error, | |
1583 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1584 | gh_owner ? gh_owner->comm : "(ended)", buffer); | |
7c52b166 | 1585 | return 0; |
b3b94faa DT |
1586 | } |
1587 | ||
6802e340 SW |
1588 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1589 | { | |
1590 | char *p = buf; | |
1591 | if (test_bit(GLF_LOCK, gflags)) | |
1592 | *p++ = 'l'; | |
6802e340 SW |
1593 | if (test_bit(GLF_DEMOTE, gflags)) |
1594 | *p++ = 'D'; | |
1595 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1596 | *p++ = 'd'; | |
1597 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1598 | *p++ = 'p'; | |
1599 | if (test_bit(GLF_DIRTY, gflags)) | |
1600 | *p++ = 'y'; | |
1601 | if (test_bit(GLF_LFLUSH, gflags)) | |
1602 | *p++ = 'f'; | |
1603 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1604 | *p++ = 'i'; | |
1605 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1606 | *p++ = 'r'; | |
f057f6cd | 1607 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1608 | *p++ = 'I'; |
f057f6cd SW |
1609 | if (test_bit(GLF_FROZEN, gflags)) |
1610 | *p++ = 'F'; | |
6802e340 SW |
1611 | *p = 0; |
1612 | return buf; | |
b3b94faa DT |
1613 | } |
1614 | ||
1615 | /** | |
6802e340 SW |
1616 | * __dump_glock - print information about a glock |
1617 | * @seq: The seq_file struct | |
b3b94faa | 1618 | * @gl: the glock |
6802e340 SW |
1619 | * |
1620 | * The file format is as follows: | |
1621 | * One line per object, capital letters are used to indicate objects | |
1622 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1623 | * other objects are indented by a single space and follow the glock to | |
1624 | * which they are related. Fields are indicated by lower case letters | |
1625 | * followed by a colon and the field value, except for strings which are in | |
1626 | * [] so that its possible to see if they are composed of spaces for | |
1627 | * example. The field's are n = number (id of the object), f = flags, | |
1628 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1629 | * |
1630 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1631 | */ | |
1632 | ||
6802e340 | 1633 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1634 | { |
6802e340 SW |
1635 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1636 | unsigned long long dtime; | |
1637 | const struct gfs2_holder *gh; | |
1638 | char gflags_buf[32]; | |
1639 | int error = 0; | |
b3b94faa | 1640 | |
6802e340 SW |
1641 | dtime = jiffies - gl->gl_demote_time; |
1642 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1643 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1644 | dtime = 0; | |
f057f6cd | 1645 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu a:%d r:%d\n", |
6802e340 SW |
1646 | state2str(gl->gl_state), |
1647 | gl->gl_name.ln_type, | |
1648 | (unsigned long long)gl->gl_name.ln_number, | |
1649 | gflags2str(gflags_buf, &gl->gl_flags), | |
1650 | state2str(gl->gl_target), | |
1651 | state2str(gl->gl_demote_state), dtime, | |
6802e340 SW |
1652 | atomic_read(&gl->gl_ail_count), |
1653 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1654 | |
b3b94faa | 1655 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1656 | error = dump_holder(seq, gh); |
b3b94faa DT |
1657 | if (error) |
1658 | goto out; | |
1659 | } | |
6802e340 SW |
1660 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1661 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1662 | out: |
b3b94faa DT |
1663 | return error; |
1664 | } | |
1665 | ||
6802e340 SW |
1666 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1667 | { | |
1668 | int ret; | |
1669 | spin_lock(&gl->gl_spin); | |
1670 | ret = __dump_glock(seq, gl); | |
1671 | spin_unlock(&gl->gl_spin); | |
1672 | return ret; | |
1673 | } | |
1674 | ||
b3b94faa DT |
1675 | /** |
1676 | * gfs2_dump_lockstate - print out the current lockstate | |
1677 | * @sdp: the filesystem | |
1678 | * @ub: the buffer to copy the information into | |
1679 | * | |
1680 | * If @ub is NULL, dump the lockstate to the console. | |
1681 | * | |
1682 | */ | |
1683 | ||
08bc2dbc | 1684 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1685 | { |
b3b94faa | 1686 | struct gfs2_glock *gl; |
b6397893 | 1687 | struct hlist_node *h; |
b3b94faa DT |
1688 | unsigned int x; |
1689 | int error = 0; | |
1690 | ||
1691 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1692 | |
087efdd3 | 1693 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1694 | |
b6397893 | 1695 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1696 | if (gl->gl_sbd != sdp) |
1697 | continue; | |
b3b94faa | 1698 | |
7c52b166 | 1699 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1700 | if (error) |
1701 | break; | |
1702 | } | |
1703 | ||
087efdd3 | 1704 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1705 | |
1706 | if (error) | |
1707 | break; | |
1708 | } | |
1709 | ||
1710 | ||
1711 | return error; | |
1712 | } | |
1713 | ||
8fbbfd21 | 1714 | |
85d1da67 SW |
1715 | int __init gfs2_glock_init(void) |
1716 | { | |
1717 | unsigned i; | |
1718 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1719 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1720 | } |
087efdd3 SW |
1721 | #ifdef GL_HASH_LOCK_SZ |
1722 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1723 | rwlock_init(&gl_hash_locks[i]); | |
1724 | } | |
1725 | #endif | |
8fbbfd21 | 1726 | |
c4f68a13 | 1727 | glock_workqueue = create_workqueue("glock_workqueue"); |
97cc1025 | 1728 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1729 | return PTR_ERR(glock_workqueue); |
97cc1025 SW |
1730 | |
1731 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1732 | |
85d1da67 SW |
1733 | return 0; |
1734 | } | |
1735 | ||
8fbbfd21 SW |
1736 | void gfs2_glock_exit(void) |
1737 | { | |
97cc1025 | 1738 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1739 | destroy_workqueue(glock_workqueue); |
8fbbfd21 SW |
1740 | } |
1741 | ||
6802e340 | 1742 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1743 | { |
7b08fc62 SW |
1744 | struct gfs2_glock *gl; |
1745 | ||
a947e033 | 1746 | restart: |
7a0079d9 | 1747 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1748 | gl = gi->gl; |
1749 | if (gl) { | |
a947e033 AD |
1750 | gi->gl = hlist_entry(gl->gl_list.next, |
1751 | struct gfs2_glock, gl_list); | |
c1e817d0 SW |
1752 | } else { |
1753 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1754 | struct gfs2_glock, gl_list); | |
7c52b166 | 1755 | } |
c1e817d0 SW |
1756 | if (gi->gl) |
1757 | gfs2_glock_hold(gi->gl); | |
7a0079d9 | 1758 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1759 | if (gl) |
1760 | gfs2_glock_put(gl); | |
6802e340 | 1761 | while (gi->gl == NULL) { |
c1e817d0 | 1762 | gi->hash++; |
7b08fc62 SW |
1763 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
1764 | return 1; | |
1765 | read_lock(gl_lock_addr(gi->hash)); | |
1766 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1767 | struct gfs2_glock, gl_list); | |
1768 | if (gi->gl) | |
1769 | gfs2_glock_hold(gi->gl); | |
1770 | read_unlock(gl_lock_addr(gi->hash)); | |
1771 | } | |
a947e033 AD |
1772 | |
1773 | if (gi->sdp != gi->gl->gl_sbd) | |
1774 | goto restart; | |
1775 | ||
7c52b166 RP |
1776 | return 0; |
1777 | } | |
1778 | ||
6802e340 | 1779 | static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) |
7c52b166 | 1780 | { |
7b08fc62 SW |
1781 | if (gi->gl) |
1782 | gfs2_glock_put(gi->gl); | |
a947e033 | 1783 | gi->gl = NULL; |
7c52b166 RP |
1784 | } |
1785 | ||
6802e340 | 1786 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1787 | { |
6802e340 | 1788 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1789 | loff_t n = *pos; |
1790 | ||
6802e340 | 1791 | gi->hash = 0; |
7c52b166 | 1792 | |
6802e340 | 1793 | do { |
7c52b166 RP |
1794 | if (gfs2_glock_iter_next(gi)) { |
1795 | gfs2_glock_iter_free(gi); | |
1796 | return NULL; | |
1797 | } | |
6802e340 | 1798 | } while (n--); |
7c52b166 | 1799 | |
6802e340 | 1800 | return gi->gl; |
7c52b166 RP |
1801 | } |
1802 | ||
6802e340 | 1803 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1804 | loff_t *pos) |
1805 | { | |
6802e340 | 1806 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1807 | |
1808 | (*pos)++; | |
1809 | ||
1810 | if (gfs2_glock_iter_next(gi)) { | |
1811 | gfs2_glock_iter_free(gi); | |
1812 | return NULL; | |
1813 | } | |
1814 | ||
6802e340 | 1815 | return gi->gl; |
7c52b166 RP |
1816 | } |
1817 | ||
6802e340 | 1818 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1819 | { |
6802e340 SW |
1820 | struct gfs2_glock_iter *gi = seq->private; |
1821 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
1822 | } |
1823 | ||
6802e340 | 1824 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1825 | { |
6802e340 | 1826 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1827 | } |
1828 | ||
4ef29002 | 1829 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1830 | .start = gfs2_glock_seq_start, |
1831 | .next = gfs2_glock_seq_next, | |
1832 | .stop = gfs2_glock_seq_stop, | |
1833 | .show = gfs2_glock_seq_show, | |
1834 | }; | |
1835 | ||
1836 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1837 | { | |
6802e340 SW |
1838 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1839 | sizeof(struct gfs2_glock_iter)); | |
1840 | if (ret == 0) { | |
1841 | struct seq_file *seq = file->private_data; | |
1842 | struct gfs2_glock_iter *gi = seq->private; | |
1843 | gi->sdp = inode->i_private; | |
1844 | } | |
1845 | return ret; | |
7c52b166 RP |
1846 | } |
1847 | ||
1848 | static const struct file_operations gfs2_debug_fops = { | |
1849 | .owner = THIS_MODULE, | |
1850 | .open = gfs2_debugfs_open, | |
1851 | .read = seq_read, | |
1852 | .llseek = seq_lseek, | |
6802e340 | 1853 | .release = seq_release_private, |
7c52b166 RP |
1854 | }; |
1855 | ||
1856 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1857 | { | |
5f882096 RP |
1858 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1859 | if (!sdp->debugfs_dir) | |
1860 | return -ENOMEM; | |
1861 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1862 | S_IFREG | S_IRUGO, | |
1863 | sdp->debugfs_dir, sdp, | |
1864 | &gfs2_debug_fops); | |
1865 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1866 | return -ENOMEM; |
1867 | ||
1868 | return 0; | |
1869 | } | |
1870 | ||
1871 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1872 | { | |
5f882096 RP |
1873 | if (sdp && sdp->debugfs_dir) { |
1874 | if (sdp->debugfs_dentry_glocks) { | |
1875 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1876 | sdp->debugfs_dentry_glocks = NULL; | |
1877 | } | |
1878 | debugfs_remove(sdp->debugfs_dir); | |
1879 | sdp->debugfs_dir = NULL; | |
1880 | } | |
7c52b166 RP |
1881 | } |
1882 | ||
1883 | int gfs2_register_debugfs(void) | |
1884 | { | |
1885 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1886 | return gfs2_root ? 0 : -ENOMEM; | |
1887 | } | |
1888 | ||
1889 | void gfs2_unregister_debugfs(void) | |
1890 | { | |
1891 | debugfs_remove(gfs2_root); | |
5f882096 | 1892 | gfs2_root = NULL; |
7c52b166 | 1893 | } |