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; |
b94a170e | 66 | struct workqueue_struct *gfs2_delete_workqueue; |
97cc1025 SW |
67 | static LIST_HEAD(lru_list); |
68 | static atomic_t lru_count = ATOMIC_INIT(0); | |
eb8374e7 | 69 | static DEFINE_SPINLOCK(lru_lock); |
08bc2dbc | 70 | |
b6397893 | 71 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
72 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
73 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
74 | ||
85d1da67 | 75 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 76 | static struct dentry *gfs2_root; |
087efdd3 SW |
77 | |
78 | /* | |
79 | * Despite what you might think, the numbers below are not arbitrary :-) | |
80 | * They are taken from the ipv4 routing hash code, which is well tested | |
81 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
82 | * but for now this should be fine. | |
83 | * | |
84 | * The reason for putting the locks in a separate array from the list heads | |
85 | * is that we can have fewer locks than list heads and save memory. We use | |
86 | * the same hash function for both, but with a different hash mask. | |
87 | */ | |
88 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
89 | defined(CONFIG_PROVE_LOCKING) | |
90 | ||
91 | #ifdef CONFIG_LOCKDEP | |
92 | # define GL_HASH_LOCK_SZ 256 | |
93 | #else | |
94 | # if NR_CPUS >= 32 | |
95 | # define GL_HASH_LOCK_SZ 4096 | |
96 | # elif NR_CPUS >= 16 | |
97 | # define GL_HASH_LOCK_SZ 2048 | |
98 | # elif NR_CPUS >= 8 | |
99 | # define GL_HASH_LOCK_SZ 1024 | |
100 | # elif NR_CPUS >= 4 | |
101 | # define GL_HASH_LOCK_SZ 512 | |
102 | # else | |
103 | # define GL_HASH_LOCK_SZ 256 | |
104 | # endif | |
105 | #endif | |
106 | ||
107 | /* We never want more locks than chains */ | |
108 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
109 | # undef GL_HASH_LOCK_SZ | |
110 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
111 | #endif | |
112 | ||
113 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
114 | ||
115 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
116 | { | |
94610610 | 117 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
118 | } |
119 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 120 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
121 | { |
122 | return NULL; | |
123 | } | |
124 | #endif | |
85d1da67 | 125 | |
b3b94faa DT |
126 | /** |
127 | * gl_hash() - Turn glock number into hash bucket number | |
128 | * @lock: The glock number | |
129 | * | |
130 | * Returns: The number of the corresponding hash bucket | |
131 | */ | |
132 | ||
b8547856 SW |
133 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
134 | const struct lm_lockname *name) | |
b3b94faa DT |
135 | { |
136 | unsigned int h; | |
137 | ||
cd915493 | 138 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 139 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 140 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
141 | h &= GFS2_GL_HASH_MASK; |
142 | ||
143 | return h; | |
144 | } | |
145 | ||
146 | /** | |
147 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
148 | * @gl: The glock to release | |
149 | * | |
150 | * Also calls lock module to release its internal structure for this glock. | |
151 | * | |
152 | */ | |
153 | ||
154 | static void glock_free(struct gfs2_glock *gl) | |
155 | { | |
156 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
157 | struct inode *aspace = gl->gl_aspace; | |
158 | ||
b3b94faa DT |
159 | if (aspace) |
160 | gfs2_aspace_put(aspace); | |
63997775 | 161 | trace_gfs2_glock_put(gl); |
f057f6cd | 162 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gfs2_glock_cachep, gl); |
b3b94faa DT |
163 | } |
164 | ||
165 | /** | |
166 | * gfs2_glock_hold() - increment reference count on glock | |
167 | * @gl: The glock to hold | |
168 | * | |
169 | */ | |
170 | ||
b94a170e | 171 | void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 172 | { |
d8348de0 | 173 | GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
16feb9fe | 174 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
175 | } |
176 | ||
8ff22a6f BM |
177 | /** |
178 | * demote_ok - Check to see if it's ok to unlock a glock | |
179 | * @gl: the glock | |
180 | * | |
181 | * Returns: 1 if it's ok | |
182 | */ | |
183 | ||
184 | static int demote_ok(const struct gfs2_glock *gl) | |
185 | { | |
186 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
187 | ||
188 | if (gl->gl_state == LM_ST_UNLOCKED) | |
189 | return 0; | |
190 | if (!list_empty(&gl->gl_holders)) | |
191 | return 0; | |
192 | if (glops->go_demote_ok) | |
193 | return glops->go_demote_ok(gl); | |
194 | return 1; | |
195 | } | |
196 | ||
97cc1025 SW |
197 | /** |
198 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
199 | * @gl: the glock | |
200 | * | |
201 | */ | |
202 | ||
203 | static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
204 | { | |
8ff22a6f BM |
205 | int may_reclaim; |
206 | may_reclaim = (demote_ok(gl) && | |
207 | (atomic_read(&gl->gl_ref) == 1 || | |
208 | (gl->gl_name.ln_type == LM_TYPE_INODE && | |
209 | atomic_read(&gl->gl_ref) <= 2))); | |
97cc1025 | 210 | spin_lock(&lru_lock); |
8ff22a6f | 211 | if (list_empty(&gl->gl_lru) && may_reclaim) { |
97cc1025 SW |
212 | list_add_tail(&gl->gl_lru, &lru_list); |
213 | atomic_inc(&lru_count); | |
214 | } | |
215 | spin_unlock(&lru_lock); | |
216 | } | |
217 | ||
8ff22a6f BM |
218 | /** |
219 | * gfs2_glock_put_nolock() - Decrement reference count on glock | |
220 | * @gl: The glock to put | |
221 | * | |
222 | * This function should only be used if the caller has its own reference | |
223 | * to the glock, in addition to the one it is dropping. | |
224 | */ | |
225 | ||
b94a170e | 226 | void gfs2_glock_put_nolock(struct gfs2_glock *gl) |
8ff22a6f BM |
227 | { |
228 | if (atomic_dec_and_test(&gl->gl_ref)) | |
229 | GLOCK_BUG_ON(gl, 1); | |
230 | gfs2_glock_schedule_for_reclaim(gl); | |
231 | } | |
232 | ||
b3b94faa DT |
233 | /** |
234 | * gfs2_glock_put() - Decrement reference count on glock | |
235 | * @gl: The glock to put | |
236 | * | |
237 | */ | |
238 | ||
239 | int gfs2_glock_put(struct gfs2_glock *gl) | |
240 | { | |
b3b94faa DT |
241 | int rv = 0; |
242 | ||
087efdd3 | 243 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 244 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 245 | hlist_del(&gl->gl_list); |
087efdd3 | 246 | write_unlock(gl_lock_addr(gl->gl_hash)); |
97cc1025 SW |
247 | spin_lock(&lru_lock); |
248 | if (!list_empty(&gl->gl_lru)) { | |
249 | list_del_init(&gl->gl_lru); | |
250 | atomic_dec(&lru_count); | |
251 | } | |
252 | spin_unlock(&lru_lock); | |
6802e340 | 253 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
b3b94faa DT |
254 | glock_free(gl); |
255 | rv = 1; | |
256 | goto out; | |
257 | } | |
8ff22a6f BM |
258 | spin_lock(&gl->gl_spin); |
259 | gfs2_glock_schedule_for_reclaim(gl); | |
260 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 261 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 262 | out: |
b3b94faa DT |
263 | return rv; |
264 | } | |
265 | ||
b3b94faa DT |
266 | /** |
267 | * search_bucket() - Find struct gfs2_glock by lock number | |
268 | * @bucket: the bucket to search | |
269 | * @name: The lock name | |
270 | * | |
271 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
272 | */ | |
273 | ||
37b2fa6a | 274 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 275 | const struct gfs2_sbd *sdp, |
d6a53727 | 276 | const struct lm_lockname *name) |
b3b94faa DT |
277 | { |
278 | struct gfs2_glock *gl; | |
b6397893 | 279 | struct hlist_node *h; |
b3b94faa | 280 | |
b6397893 | 281 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
282 | if (!lm_name_equal(&gl->gl_name, name)) |
283 | continue; | |
899be4d3 SW |
284 | if (gl->gl_sbd != sdp) |
285 | continue; | |
b3b94faa | 286 | |
16feb9fe | 287 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
288 | |
289 | return gl; | |
290 | } | |
291 | ||
292 | return NULL; | |
293 | } | |
294 | ||
6802e340 SW |
295 | /** |
296 | * may_grant - check if its ok to grant a new lock | |
297 | * @gl: The glock | |
298 | * @gh: The lock request which we wish to grant | |
299 | * | |
300 | * Returns: true if its ok to grant the lock | |
301 | */ | |
302 | ||
303 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
304 | { | |
305 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
306 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
307 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
308 | return 0; | |
309 | if (gl->gl_state == gh->gh_state) | |
310 | return 1; | |
311 | if (gh->gh_flags & GL_EXACT) | |
312 | return 0; | |
209806ab SW |
313 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
314 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
315 | return 1; | |
316 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
317 | return 1; | |
318 | } | |
6802e340 SW |
319 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
320 | return 1; | |
321 | return 0; | |
322 | } | |
323 | ||
324 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
325 | { | |
326 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
327 | smp_mb__after_clear_bit(); | |
328 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
329 | } | |
330 | ||
331 | /** | |
332 | * do_promote - promote as many requests as possible on the current queue | |
333 | * @gl: The glock | |
334 | * | |
813e0c46 SW |
335 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
336 | * if a type specific operation is underway. | |
6802e340 SW |
337 | */ |
338 | ||
339 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
340 | __releases(&gl->gl_spin) |
341 | __acquires(&gl->gl_spin) | |
6802e340 SW |
342 | { |
343 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
344 | struct gfs2_holder *gh, *tmp; | |
345 | int ret; | |
346 | ||
347 | restart: | |
348 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
349 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
350 | continue; | |
351 | if (may_grant(gl, gh)) { | |
352 | if (gh->gh_list.prev == &gl->gl_holders && | |
353 | glops->go_lock) { | |
354 | spin_unlock(&gl->gl_spin); | |
355 | /* FIXME: eliminate this eventually */ | |
356 | ret = glops->go_lock(gh); | |
357 | spin_lock(&gl->gl_spin); | |
358 | if (ret) { | |
813e0c46 SW |
359 | if (ret == 1) |
360 | return 2; | |
6802e340 SW |
361 | gh->gh_error = ret; |
362 | list_del_init(&gh->gh_list); | |
63997775 | 363 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
364 | gfs2_holder_wake(gh); |
365 | goto restart; | |
366 | } | |
367 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 368 | trace_gfs2_promote(gh, 1); |
6802e340 SW |
369 | gfs2_holder_wake(gh); |
370 | goto restart; | |
371 | } | |
372 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 373 | trace_gfs2_promote(gh, 0); |
6802e340 SW |
374 | gfs2_holder_wake(gh); |
375 | continue; | |
376 | } | |
377 | if (gh->gh_list.prev == &gl->gl_holders) | |
378 | return 1; | |
379 | break; | |
380 | } | |
381 | return 0; | |
382 | } | |
383 | ||
384 | /** | |
385 | * do_error - Something unexpected has happened during a lock request | |
386 | * | |
387 | */ | |
388 | ||
389 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
390 | { | |
391 | struct gfs2_holder *gh, *tmp; | |
392 | ||
393 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
394 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
395 | continue; | |
396 | if (ret & LM_OUT_ERROR) | |
397 | gh->gh_error = -EIO; | |
398 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
399 | gh->gh_error = GLR_TRYFAILED; | |
400 | else | |
401 | continue; | |
402 | list_del_init(&gh->gh_list); | |
63997775 | 403 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
404 | gfs2_holder_wake(gh); |
405 | } | |
406 | } | |
407 | ||
408 | /** | |
409 | * find_first_waiter - find the first gh that's waiting for the glock | |
410 | * @gl: the glock | |
411 | */ | |
412 | ||
413 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
414 | { | |
415 | struct gfs2_holder *gh; | |
416 | ||
417 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
418 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
419 | return gh; | |
420 | } | |
421 | return NULL; | |
422 | } | |
423 | ||
424 | /** | |
425 | * state_change - record that the glock is now in a different state | |
426 | * @gl: the glock | |
427 | * @new_state the new state | |
428 | * | |
429 | */ | |
430 | ||
431 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
432 | { | |
433 | int held1, held2; | |
434 | ||
435 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
436 | held2 = (new_state != LM_ST_UNLOCKED); | |
437 | ||
438 | if (held1 != held2) { | |
439 | if (held2) | |
440 | gfs2_glock_hold(gl); | |
441 | else | |
8ff22a6f | 442 | gfs2_glock_put_nolock(gl); |
6802e340 SW |
443 | } |
444 | ||
445 | gl->gl_state = new_state; | |
446 | gl->gl_tchange = jiffies; | |
447 | } | |
448 | ||
449 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
450 | { | |
451 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
452 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
453 | smp_mb__after_clear_bit(); | |
454 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
455 | } | |
456 | ||
457 | /** | |
458 | * finish_xmote - The DLM has replied to one of our lock requests | |
459 | * @gl: The glock | |
460 | * @ret: The status from the DLM | |
461 | * | |
462 | */ | |
463 | ||
464 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
465 | { | |
466 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
467 | struct gfs2_holder *gh; | |
468 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 469 | int rv; |
6802e340 SW |
470 | |
471 | spin_lock(&gl->gl_spin); | |
63997775 | 472 | trace_gfs2_glock_state_change(gl, state); |
6802e340 SW |
473 | state_change(gl, state); |
474 | gh = find_first_waiter(gl); | |
475 | ||
476 | /* Demote to UN request arrived during demote to SH or DF */ | |
477 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
478 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
479 | gl->gl_target = LM_ST_UNLOCKED; | |
480 | ||
481 | /* Check for state != intended state */ | |
482 | if (unlikely(state != gl->gl_target)) { | |
483 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
484 | /* move to back of queue and try next entry */ | |
485 | if (ret & LM_OUT_CANCELED) { | |
486 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
487 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
488 | gh = find_first_waiter(gl); | |
489 | gl->gl_target = gh->gh_state; | |
490 | goto retry; | |
491 | } | |
492 | /* Some error or failed "try lock" - report it */ | |
493 | if ((ret & LM_OUT_ERROR) || | |
494 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
495 | gl->gl_target = gl->gl_state; | |
496 | do_error(gl, ret); | |
497 | goto out; | |
498 | } | |
499 | } | |
500 | switch(state) { | |
501 | /* Unlocked due to conversion deadlock, try again */ | |
502 | case LM_ST_UNLOCKED: | |
503 | retry: | |
504 | do_xmote(gl, gh, gl->gl_target); | |
505 | break; | |
506 | /* Conversion fails, unlock and try again */ | |
507 | case LM_ST_SHARED: | |
508 | case LM_ST_DEFERRED: | |
509 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
510 | break; | |
511 | default: /* Everything else */ | |
512 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
513 | GLOCK_BUG_ON(gl, 1); | |
514 | } | |
515 | spin_unlock(&gl->gl_spin); | |
516 | gfs2_glock_put(gl); | |
517 | return; | |
518 | } | |
519 | ||
520 | /* Fast path - we got what we asked for */ | |
521 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
522 | gfs2_demote_wake(gl); | |
523 | if (state != LM_ST_UNLOCKED) { | |
524 | if (glops->go_xmote_bh) { | |
6802e340 SW |
525 | spin_unlock(&gl->gl_spin); |
526 | rv = glops->go_xmote_bh(gl, gh); | |
527 | if (rv == -EAGAIN) | |
528 | return; | |
529 | spin_lock(&gl->gl_spin); | |
530 | if (rv) { | |
531 | do_error(gl, rv); | |
532 | goto out; | |
533 | } | |
534 | } | |
813e0c46 SW |
535 | rv = do_promote(gl); |
536 | if (rv == 2) | |
537 | goto out_locked; | |
6802e340 SW |
538 | } |
539 | out: | |
540 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 541 | out_locked: |
6802e340 SW |
542 | spin_unlock(&gl->gl_spin); |
543 | gfs2_glock_put(gl); | |
544 | } | |
545 | ||
546 | static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, | |
f057f6cd | 547 | unsigned int req_state, |
6802e340 SW |
548 | unsigned int flags) |
549 | { | |
550 | int ret = LM_OUT_ERROR; | |
048bca22 SW |
551 | |
552 | if (!sdp->sd_lockstruct.ls_ops->lm_lock) | |
553 | return req_state == LM_ST_UNLOCKED ? 0 : req_state; | |
554 | ||
6802e340 | 555 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
f057f6cd | 556 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, |
6802e340 SW |
557 | req_state, flags); |
558 | return ret; | |
559 | } | |
560 | ||
561 | /** | |
562 | * do_xmote - Calls the DLM to change the state of a lock | |
563 | * @gl: The lock state | |
564 | * @gh: The holder (only for promotes) | |
565 | * @target: The target lock state | |
566 | * | |
567 | */ | |
568 | ||
569 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
570 | __releases(&gl->gl_spin) |
571 | __acquires(&gl->gl_spin) | |
6802e340 SW |
572 | { |
573 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
574 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
575 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
576 | int ret; | |
577 | ||
578 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
579 | LM_FLAG_PRIORITY); | |
580 | BUG_ON(gl->gl_state == target); | |
581 | BUG_ON(gl->gl_state == gl->gl_target); | |
582 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
583 | glops->go_inval) { | |
584 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
585 | do_error(gl, 0); /* Fail queued try locks */ | |
586 | } | |
587 | spin_unlock(&gl->gl_spin); | |
588 | if (glops->go_xmote_th) | |
589 | glops->go_xmote_th(gl); | |
590 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
591 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
592 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
593 | ||
594 | gfs2_glock_hold(gl); | |
595 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
596 | gl->gl_state == LM_ST_DEFERRED) && | |
597 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
598 | lck_flags |= LM_FLAG_TRY_1CB; | |
f057f6cd | 599 | ret = gfs2_lm_lock(sdp, gl, target, lck_flags); |
6802e340 SW |
600 | |
601 | if (!(ret & LM_OUT_ASYNC)) { | |
602 | finish_xmote(gl, ret); | |
603 | gfs2_glock_hold(gl); | |
604 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
605 | gfs2_glock_put(gl); | |
606 | } else { | |
607 | GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); | |
608 | } | |
609 | spin_lock(&gl->gl_spin); | |
610 | } | |
611 | ||
612 | /** | |
613 | * find_first_holder - find the first "holder" gh | |
614 | * @gl: the glock | |
615 | */ | |
616 | ||
617 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
618 | { | |
619 | struct gfs2_holder *gh; | |
620 | ||
621 | if (!list_empty(&gl->gl_holders)) { | |
622 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
623 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
624 | return gh; | |
625 | } | |
626 | return NULL; | |
627 | } | |
628 | ||
629 | /** | |
630 | * run_queue - do all outstanding tasks related to a glock | |
631 | * @gl: The glock in question | |
632 | * @nonblock: True if we must not block in run_queue | |
633 | * | |
634 | */ | |
635 | ||
636 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
637 | __releases(&gl->gl_spin) |
638 | __acquires(&gl->gl_spin) | |
6802e340 SW |
639 | { |
640 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 641 | int ret; |
6802e340 SW |
642 | |
643 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
644 | return; | |
645 | ||
646 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
647 | ||
648 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
649 | gl->gl_demote_state != gl->gl_state) { | |
650 | if (find_first_holder(gl)) | |
d8348de0 | 651 | goto out_unlock; |
6802e340 SW |
652 | if (nonblock) |
653 | goto out_sched; | |
654 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 655 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
656 | gl->gl_target = gl->gl_demote_state; |
657 | } else { | |
658 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
659 | gfs2_demote_wake(gl); | |
813e0c46 SW |
660 | ret = do_promote(gl); |
661 | if (ret == 0) | |
d8348de0 | 662 | goto out_unlock; |
813e0c46 | 663 | if (ret == 2) |
a228df63 | 664 | goto out; |
6802e340 SW |
665 | gh = find_first_waiter(gl); |
666 | gl->gl_target = gh->gh_state; | |
667 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
668 | do_error(gl, 0); /* Fail queued try locks */ | |
669 | } | |
670 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 671 | out: |
6802e340 SW |
672 | return; |
673 | ||
674 | out_sched: | |
675 | gfs2_glock_hold(gl); | |
676 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
8ff22a6f | 677 | gfs2_glock_put_nolock(gl); |
d8348de0 | 678 | out_unlock: |
6802e340 | 679 | clear_bit(GLF_LOCK, &gl->gl_flags); |
a228df63 | 680 | goto out; |
6802e340 SW |
681 | } |
682 | ||
b94a170e BM |
683 | static void delete_work_func(struct work_struct *work) |
684 | { | |
685 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); | |
686 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
687 | struct gfs2_inode *ip = NULL; | |
688 | struct inode *inode; | |
689 | u64 no_addr = 0; | |
690 | ||
691 | spin_lock(&gl->gl_spin); | |
692 | ip = (struct gfs2_inode *)gl->gl_object; | |
693 | if (ip) | |
694 | no_addr = ip->i_no_addr; | |
695 | spin_unlock(&gl->gl_spin); | |
696 | if (ip) { | |
697 | inode = gfs2_ilookup(sdp->sd_vfs, no_addr); | |
698 | if (inode) { | |
699 | d_prune_aliases(inode); | |
700 | iput(inode); | |
701 | } | |
702 | } | |
703 | gfs2_glock_put(gl); | |
704 | } | |
705 | ||
c4f68a13 BM |
706 | static void glock_work_func(struct work_struct *work) |
707 | { | |
6802e340 | 708 | unsigned long delay = 0; |
c4f68a13 BM |
709 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
710 | ||
6802e340 SW |
711 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
712 | finish_xmote(gl, gl->gl_reply); | |
a228df63 | 713 | down_read(&gfs2_umount_flush_sem); |
c4f68a13 | 714 | spin_lock(&gl->gl_spin); |
265d529c SW |
715 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
716 | gl->gl_state != LM_ST_UNLOCKED && | |
717 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
718 | unsigned long holdtime, now = jiffies; |
719 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
720 | if (time_before(now, holdtime)) | |
721 | delay = holdtime - now; | |
722 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
723 | } | |
724 | run_queue(gl, 0); | |
c4f68a13 | 725 | spin_unlock(&gl->gl_spin); |
a228df63 | 726 | up_read(&gfs2_umount_flush_sem); |
6802e340 SW |
727 | if (!delay || |
728 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
729 | gfs2_glock_put(gl); | |
c4f68a13 BM |
730 | } |
731 | ||
b3b94faa DT |
732 | /** |
733 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
734 | * @sdp: The GFS2 superblock | |
735 | * @number: the lock number | |
736 | * @glops: The glock_operations to use | |
737 | * @create: If 0, don't create the glock if it doesn't exist | |
738 | * @glp: the glock is returned here | |
739 | * | |
740 | * This does not lock a glock, just finds/creates structures for one. | |
741 | * | |
742 | * Returns: errno | |
743 | */ | |
744 | ||
cd915493 | 745 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 746 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
747 | struct gfs2_glock **glp) |
748 | { | |
37b2fa6a | 749 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 750 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 751 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
752 | int error; |
753 | ||
087efdd3 | 754 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 755 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 756 | read_unlock(gl_lock_addr(hash)); |
b3b94faa | 757 | |
64d576ba SW |
758 | *glp = gl; |
759 | if (gl) | |
b3b94faa | 760 | return 0; |
64d576ba SW |
761 | if (!create) |
762 | return -ENOENT; | |
b3b94faa DT |
763 | |
764 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
765 | if (!gl) | |
766 | return -ENOMEM; | |
767 | ||
ec45d9f5 | 768 | gl->gl_flags = 0; |
b3b94faa | 769 | gl->gl_name = name; |
16feb9fe | 770 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 771 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 772 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 773 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 774 | gl->gl_hash = hash; |
b3b94faa | 775 | gl->gl_ops = glops; |
f057f6cd SW |
776 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
777 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
778 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 779 | gl->gl_tchange = jiffies; |
ec45d9f5 | 780 | gl->gl_object = NULL; |
b3b94faa | 781 | gl->gl_sbd = sdp; |
ec45d9f5 | 782 | gl->gl_aspace = NULL; |
c4f68a13 | 783 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b94a170e | 784 | INIT_WORK(&gl->gl_delete, delete_work_func); |
b3b94faa DT |
785 | |
786 | /* If this glock protects actual on-disk data or metadata blocks, | |
787 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 788 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
789 | gl->gl_aspace = gfs2_aspace_get(sdp); |
790 | if (!gl->gl_aspace) { | |
791 | error = -ENOMEM; | |
792 | goto fail; | |
793 | } | |
794 | } | |
795 | ||
087efdd3 | 796 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 797 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 798 | if (tmp) { |
087efdd3 | 799 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
800 | glock_free(gl); |
801 | gl = tmp; | |
802 | } else { | |
b6397893 | 803 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 804 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
805 | } |
806 | ||
807 | *glp = gl; | |
808 | ||
809 | return 0; | |
810 | ||
ec45d9f5 | 811 | fail: |
907b9bce | 812 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
813 | return error; |
814 | } | |
815 | ||
816 | /** | |
817 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
818 | * @gl: the glock | |
819 | * @state: the state we're requesting | |
820 | * @flags: the modifier flags | |
821 | * @gh: the holder structure | |
822 | * | |
823 | */ | |
824 | ||
190562bd | 825 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
826 | struct gfs2_holder *gh) |
827 | { | |
828 | INIT_LIST_HEAD(&gh->gh_list); | |
829 | gh->gh_gl = gl; | |
d0dc80db | 830 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 831 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
832 | gh->gh_state = state; |
833 | gh->gh_flags = flags; | |
834 | gh->gh_error = 0; | |
835 | gh->gh_iflags = 0; | |
b3b94faa DT |
836 | gfs2_glock_hold(gl); |
837 | } | |
838 | ||
839 | /** | |
840 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
841 | * @state: the state we're requesting | |
842 | * @flags: the modifier flags | |
843 | * @gh: the holder structure | |
844 | * | |
845 | * Don't mess with the glock. | |
846 | * | |
847 | */ | |
848 | ||
190562bd | 849 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
850 | { |
851 | gh->gh_state = state; | |
579b78a4 | 852 | gh->gh_flags = flags; |
3b8249f6 | 853 | gh->gh_iflags = 0; |
d0dc80db | 854 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
855 | } |
856 | ||
857 | /** | |
858 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
859 | * @gh: the holder structure | |
860 | * | |
861 | */ | |
862 | ||
863 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
864 | { | |
b1e058da | 865 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
866 | gfs2_glock_put(gh->gh_gl); |
867 | gh->gh_gl = NULL; | |
d0dc80db | 868 | gh->gh_ip = 0; |
b3b94faa DT |
869 | } |
870 | ||
fe64d517 SW |
871 | /** |
872 | * gfs2_glock_holder_wait | |
873 | * @word: unused | |
874 | * | |
875 | * This function and gfs2_glock_demote_wait both show up in the WCHAN | |
876 | * field. Thus I've separated these otherwise identical functions in | |
877 | * order to be more informative to the user. | |
878 | */ | |
879 | ||
880 | static int gfs2_glock_holder_wait(void *word) | |
fee852e3 SW |
881 | { |
882 | schedule(); | |
883 | return 0; | |
884 | } | |
885 | ||
fe64d517 SW |
886 | static int gfs2_glock_demote_wait(void *word) |
887 | { | |
888 | schedule(); | |
889 | return 0; | |
890 | } | |
891 | ||
6802e340 | 892 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 893 | { |
6802e340 | 894 | might_sleep(); |
fe64d517 | 895 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
da755fdb SW |
896 | } |
897 | ||
6802e340 | 898 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 899 | { |
6802e340 | 900 | might_sleep(); |
fe64d517 | 901 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
b3b94faa DT |
902 | } |
903 | ||
904 | /** | |
6802e340 SW |
905 | * handle_callback - process a demote request |
906 | * @gl: the glock | |
907 | * @state: the state the caller wants us to change to | |
b3b94faa | 908 | * |
6802e340 SW |
909 | * There are only two requests that we are going to see in actual |
910 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
911 | */ |
912 | ||
6802e340 | 913 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 914 | unsigned long delay) |
b3b94faa | 915 | { |
6802e340 | 916 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 917 | |
6802e340 SW |
918 | set_bit(bit, &gl->gl_flags); |
919 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
920 | gl->gl_demote_state = state; | |
921 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
922 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
923 | gl->gl_demote_state != state) { | |
924 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 925 | } |
b94a170e BM |
926 | if (gl->gl_ops->go_callback) |
927 | gl->gl_ops->go_callback(gl); | |
63997775 | 928 | trace_gfs2_demote_rq(gl); |
b3b94faa DT |
929 | } |
930 | ||
931 | /** | |
6802e340 | 932 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
933 | * @gh: the glock holder |
934 | * | |
935 | * Returns: 0 on success | |
936 | */ | |
937 | ||
6802e340 | 938 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 939 | { |
fee852e3 | 940 | wait_on_holder(gh); |
b3b94faa DT |
941 | return gh->gh_error; |
942 | } | |
943 | ||
6802e340 | 944 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 RP |
945 | { |
946 | va_list args; | |
947 | ||
948 | va_start(args, fmt); | |
6802e340 SW |
949 | if (seq) { |
950 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 951 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
952 | seq_printf(seq, gi->string); |
953 | } else { | |
954 | printk(KERN_ERR " "); | |
7c52b166 | 955 | vprintk(fmt, args); |
6802e340 | 956 | } |
7c52b166 RP |
957 | va_end(args); |
958 | } | |
959 | ||
b3b94faa DT |
960 | /** |
961 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
962 | * @gh: the holder structure to add | |
963 | * | |
6802e340 SW |
964 | * Eventually we should move the recursive locking trap to a |
965 | * debugging option or something like that. This is the fast | |
966 | * path and needs to have the minimum number of distractions. | |
967 | * | |
b3b94faa DT |
968 | */ |
969 | ||
6802e340 | 970 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
971 | __releases(&gl->gl_spin) |
972 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
973 | { |
974 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
975 | struct gfs2_sbd *sdp = gl->gl_sbd; |
976 | struct list_head *insert_pt = NULL; | |
977 | struct gfs2_holder *gh2; | |
978 | int try_lock = 0; | |
b3b94faa | 979 | |
b1e058da | 980 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
981 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
982 | BUG(); | |
190562bd | 983 | |
6802e340 SW |
984 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
985 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
986 | try_lock = 1; | |
987 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
988 | goto fail; | |
989 | } | |
990 | ||
991 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
992 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
993 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
994 | goto trap_recursive; | |
995 | if (try_lock && | |
996 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
997 | !may_grant(gl, gh)) { | |
998 | fail: | |
999 | gh->gh_error = GLR_TRYFAILED; | |
1000 | gfs2_holder_wake(gh); | |
1001 | return; | |
b4c20166 | 1002 | } |
6802e340 SW |
1003 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
1004 | continue; | |
1005 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
1006 | insert_pt = &gh2->gh_list; | |
1007 | } | |
1008 | if (likely(insert_pt == NULL)) { | |
1009 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
1010 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
1011 | goto do_cancel; | |
1012 | return; | |
1013 | } | |
63997775 | 1014 | trace_gfs2_glock_queue(gh, 1); |
6802e340 SW |
1015 | list_add_tail(&gh->gh_list, insert_pt); |
1016 | do_cancel: | |
1017 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
1018 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
1019 | spin_unlock(&gl->gl_spin); | |
048bca22 | 1020 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 1021 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 1022 | spin_lock(&gl->gl_spin); |
b3b94faa | 1023 | } |
6802e340 | 1024 | return; |
b3b94faa | 1025 | |
6802e340 SW |
1026 | trap_recursive: |
1027 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
1028 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
1029 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1030 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
1031 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
1032 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
1033 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1034 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
1035 | __dump_glock(NULL, gl); | |
1036 | BUG(); | |
b3b94faa DT |
1037 | } |
1038 | ||
1039 | /** | |
1040 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1041 | * @gh: the holder structure | |
1042 | * | |
1043 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1044 | * | |
1045 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1046 | */ | |
1047 | ||
1048 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1049 | { | |
1050 | struct gfs2_glock *gl = gh->gh_gl; | |
1051 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1052 | int error = 0; | |
1053 | ||
6802e340 | 1054 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 1055 | return -EIO; |
b3b94faa | 1056 | |
b3b94faa DT |
1057 | spin_lock(&gl->gl_spin); |
1058 | add_to_queue(gh); | |
6802e340 | 1059 | run_queue(gl, 1); |
b3b94faa DT |
1060 | spin_unlock(&gl->gl_spin); |
1061 | ||
6802e340 SW |
1062 | if (!(gh->gh_flags & GL_ASYNC)) |
1063 | error = gfs2_glock_wait(gh); | |
b3b94faa | 1064 | |
b3b94faa DT |
1065 | return error; |
1066 | } | |
1067 | ||
1068 | /** | |
1069 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1070 | * @gh: the holder | |
1071 | * | |
1072 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1073 | */ | |
1074 | ||
1075 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1076 | { | |
6802e340 | 1077 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1078 | } |
1079 | ||
1080 | /** | |
1081 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1082 | * @gh: the glock holder | |
1083 | * | |
1084 | */ | |
1085 | ||
1086 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1087 | { | |
1088 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1089 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1090 | unsigned delay = 0; |
6802e340 | 1091 | int fast_path = 0; |
b3b94faa | 1092 | |
6802e340 | 1093 | spin_lock(&gl->gl_spin); |
b3b94faa | 1094 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1095 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1096 | |
b3b94faa | 1097 | list_del_init(&gh->gh_list); |
6802e340 | 1098 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1099 | if (glops->go_unlock) { |
6802e340 | 1100 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1101 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1102 | glops->go_unlock(gh); |
3042a2cc | 1103 | spin_lock(&gl->gl_spin); |
6802e340 | 1104 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1105 | } |
6802e340 SW |
1106 | if (list_empty(&gl->gl_holders) && |
1107 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1108 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1109 | fast_path = 1; | |
b3b94faa | 1110 | } |
63997775 | 1111 | trace_gfs2_glock_queue(gh, 0); |
b3b94faa | 1112 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1113 | if (likely(fast_path)) |
1114 | return; | |
c4f68a13 BM |
1115 | |
1116 | gfs2_glock_hold(gl); | |
1117 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1118 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1119 | delay = gl->gl_ops->go_min_hold_time; | |
1120 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1121 | gfs2_glock_put(gl); | |
b3b94faa DT |
1122 | } |
1123 | ||
d93cfa98 AD |
1124 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1125 | { | |
1126 | struct gfs2_glock *gl = gh->gh_gl; | |
1127 | gfs2_glock_dq(gh); | |
1128 | wait_on_demote(gl); | |
1129 | } | |
1130 | ||
b3b94faa DT |
1131 | /** |
1132 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1133 | * @gh: the holder structure | |
1134 | * | |
1135 | */ | |
1136 | ||
1137 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1138 | { | |
1139 | gfs2_glock_dq(gh); | |
1140 | gfs2_holder_uninit(gh); | |
1141 | } | |
1142 | ||
1143 | /** | |
1144 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1145 | * @sdp: the filesystem | |
1146 | * @number: the lock number | |
1147 | * @glops: the glock operations for the type of glock | |
1148 | * @state: the state to acquire the glock in | |
1149 | * @flags: modifier flags for the aquisition | |
1150 | * @gh: the struct gfs2_holder | |
1151 | * | |
1152 | * Returns: errno | |
1153 | */ | |
1154 | ||
cd915493 | 1155 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1156 | const struct gfs2_glock_operations *glops, |
1157 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1158 | { |
1159 | struct gfs2_glock *gl; | |
1160 | int error; | |
1161 | ||
1162 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1163 | if (!error) { | |
1164 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1165 | gfs2_glock_put(gl); | |
1166 | } | |
1167 | ||
1168 | return error; | |
1169 | } | |
1170 | ||
1171 | /** | |
1172 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1173 | * @arg_a: the first structure | |
1174 | * @arg_b: the second structure | |
1175 | * | |
1176 | */ | |
1177 | ||
1178 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1179 | { | |
a5e08a9e SW |
1180 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1181 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1182 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1183 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1184 | |
1185 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1186 | return 1; |
1187 | if (a->ln_number < b->ln_number) | |
1188 | return -1; | |
1c0f4872 | 1189 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1190 | return 0; |
b3b94faa DT |
1191 | } |
1192 | ||
1193 | /** | |
1194 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1195 | * @num_gh: the number of structures | |
1196 | * @ghs: an array of struct gfs2_holder structures | |
1197 | * | |
1198 | * Returns: 0 on success (all glocks acquired), | |
1199 | * errno on failure (no glocks acquired) | |
1200 | */ | |
1201 | ||
1202 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1203 | struct gfs2_holder **p) | |
1204 | { | |
1205 | unsigned int x; | |
1206 | int error = 0; | |
1207 | ||
1208 | for (x = 0; x < num_gh; x++) | |
1209 | p[x] = &ghs[x]; | |
1210 | ||
1211 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1212 | ||
1213 | for (x = 0; x < num_gh; x++) { | |
1214 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1215 | ||
1216 | error = gfs2_glock_nq(p[x]); | |
1217 | if (error) { | |
1218 | while (x--) | |
1219 | gfs2_glock_dq(p[x]); | |
1220 | break; | |
1221 | } | |
1222 | } | |
1223 | ||
1224 | return error; | |
1225 | } | |
1226 | ||
1227 | /** | |
1228 | * gfs2_glock_nq_m - acquire multiple glocks | |
1229 | * @num_gh: the number of structures | |
1230 | * @ghs: an array of struct gfs2_holder structures | |
1231 | * | |
b3b94faa DT |
1232 | * |
1233 | * Returns: 0 on success (all glocks acquired), | |
1234 | * errno on failure (no glocks acquired) | |
1235 | */ | |
1236 | ||
1237 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1238 | { | |
eaf5bd3c SW |
1239 | struct gfs2_holder *tmp[4]; |
1240 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1241 | int error = 0; |
1242 | ||
eaf5bd3c SW |
1243 | switch(num_gh) { |
1244 | case 0: | |
b3b94faa | 1245 | return 0; |
eaf5bd3c | 1246 | case 1: |
b3b94faa DT |
1247 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1248 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1249 | default: |
1250 | if (num_gh <= 4) | |
b3b94faa | 1251 | break; |
eaf5bd3c SW |
1252 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1253 | if (!pph) | |
1254 | return -ENOMEM; | |
b3b94faa DT |
1255 | } |
1256 | ||
eaf5bd3c | 1257 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1258 | |
eaf5bd3c SW |
1259 | if (pph != tmp) |
1260 | kfree(pph); | |
b3b94faa DT |
1261 | |
1262 | return error; | |
1263 | } | |
1264 | ||
1265 | /** | |
1266 | * gfs2_glock_dq_m - release multiple glocks | |
1267 | * @num_gh: the number of structures | |
1268 | * @ghs: an array of struct gfs2_holder structures | |
1269 | * | |
1270 | */ | |
1271 | ||
1272 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1273 | { | |
1274 | unsigned int x; | |
1275 | ||
1276 | for (x = 0; x < num_gh; x++) | |
1277 | gfs2_glock_dq(&ghs[x]); | |
1278 | } | |
1279 | ||
1280 | /** | |
1281 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1282 | * @num_gh: the number of structures | |
1283 | * @ghs: an array of struct gfs2_holder structures | |
1284 | * | |
1285 | */ | |
1286 | ||
1287 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1288 | { | |
1289 | unsigned int x; | |
1290 | ||
1291 | for (x = 0; x < num_gh; x++) | |
1292 | gfs2_glock_dq_uninit(&ghs[x]); | |
1293 | } | |
1294 | ||
f057f6cd | 1295 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1296 | { |
c4f68a13 BM |
1297 | unsigned long delay = 0; |
1298 | unsigned long holdtime; | |
1299 | unsigned long now = jiffies; | |
b3b94faa | 1300 | |
f057f6cd | 1301 | gfs2_glock_hold(gl); |
c4f68a13 BM |
1302 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1303 | if (time_before(now, holdtime)) | |
1304 | delay = holdtime - now; | |
dff52574 SW |
1305 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
1306 | delay = gl->gl_ops->go_min_hold_time; | |
b3b94faa | 1307 | |
6802e340 | 1308 | spin_lock(&gl->gl_spin); |
97cc1025 | 1309 | handle_callback(gl, state, delay); |
6802e340 | 1310 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1311 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1312 | gfs2_glock_put(gl); | |
b3b94faa DT |
1313 | } |
1314 | ||
1315 | /** | |
f057f6cd SW |
1316 | * gfs2_glock_complete - Callback used by locking |
1317 | * @gl: Pointer to the glock | |
1318 | * @ret: The return value from the dlm | |
b3b94faa | 1319 | * |
b3b94faa DT |
1320 | */ |
1321 | ||
f057f6cd | 1322 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1323 | { |
f057f6cd | 1324 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
f057f6cd SW |
1325 | gl->gl_reply = ret; |
1326 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) { | |
1327 | struct gfs2_holder *gh; | |
1328 | spin_lock(&gl->gl_spin); | |
1329 | gh = find_first_waiter(gl); | |
1330 | if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) && | |
1331 | (gl->gl_target != LM_ST_UNLOCKED)) || | |
1332 | ((ret & ~LM_OUT_ST_MASK) != 0)) | |
1333 | set_bit(GLF_FROZEN, &gl->gl_flags); | |
1334 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 1335 | if (test_bit(GLF_FROZEN, &gl->gl_flags)) |
b3b94faa | 1336 | return; |
b3b94faa | 1337 | } |
f057f6cd SW |
1338 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1339 | gfs2_glock_hold(gl); | |
1340 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1341 | gfs2_glock_put(gl); | |
b3b94faa DT |
1342 | } |
1343 | ||
b3b94faa | 1344 | |
97cc1025 | 1345 | static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask) |
b3b94faa DT |
1346 | { |
1347 | struct gfs2_glock *gl; | |
97cc1025 SW |
1348 | int may_demote; |
1349 | int nr_skipped = 0; | |
97cc1025 | 1350 | LIST_HEAD(skipped); |
b3b94faa | 1351 | |
97cc1025 SW |
1352 | if (nr == 0) |
1353 | goto out; | |
b3b94faa | 1354 | |
97cc1025 SW |
1355 | if (!(gfp_mask & __GFP_FS)) |
1356 | return -1; | |
b3b94faa | 1357 | |
97cc1025 SW |
1358 | spin_lock(&lru_lock); |
1359 | while(nr && !list_empty(&lru_list)) { | |
1360 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1361 | list_del_init(&gl->gl_lru); | |
1362 | atomic_dec(&lru_count); | |
1363 | ||
a51b56ff BM |
1364 | /* Check if glock is about to be freed */ |
1365 | if (atomic_read(&gl->gl_ref) == 0) | |
1366 | continue; | |
1367 | ||
97cc1025 SW |
1368 | /* Test for being demotable */ |
1369 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1370 | gfs2_glock_hold(gl); | |
97cc1025 SW |
1371 | spin_unlock(&lru_lock); |
1372 | spin_lock(&gl->gl_spin); | |
1373 | may_demote = demote_ok(gl); | |
97cc1025 SW |
1374 | if (may_demote) { |
1375 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1376 | nr--; | |
97cc1025 | 1377 | } |
2163b1e6 | 1378 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
b94a170e BM |
1379 | gfs2_glock_put_nolock(gl); |
1380 | spin_unlock(&gl->gl_spin); | |
1381 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
97cc1025 | 1382 | spin_lock(&lru_lock); |
2163b1e6 | 1383 | continue; |
97cc1025 | 1384 | } |
2163b1e6 SW |
1385 | nr_skipped++; |
1386 | list_add(&gl->gl_lru, &skipped); | |
b3b94faa | 1387 | } |
97cc1025 SW |
1388 | list_splice(&skipped, &lru_list); |
1389 | atomic_add(nr_skipped, &lru_count); | |
1390 | spin_unlock(&lru_lock); | |
1391 | out: | |
1392 | return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure; | |
b3b94faa DT |
1393 | } |
1394 | ||
97cc1025 SW |
1395 | static struct shrinker glock_shrinker = { |
1396 | .shrink = gfs2_shrink_glock_memory, | |
1397 | .seeks = DEFAULT_SEEKS, | |
1398 | }; | |
1399 | ||
b3b94faa DT |
1400 | /** |
1401 | * examine_bucket - Call a function for glock in a hash bucket | |
1402 | * @examiner: the function | |
1403 | * @sdp: the filesystem | |
1404 | * @bucket: the bucket | |
1405 | * | |
1406 | * Returns: 1 if the bucket has entries | |
1407 | */ | |
1408 | ||
1409 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1410 | unsigned int hash) |
b3b94faa | 1411 | { |
24264434 SW |
1412 | struct gfs2_glock *gl, *prev = NULL; |
1413 | int has_entries = 0; | |
b6397893 | 1414 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1415 | |
24264434 | 1416 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1417 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1418 | if (hlist_empty(head)) | |
24264434 | 1419 | goto out; |
b6397893 SW |
1420 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1421 | while(1) { | |
8fbbfd21 | 1422 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1423 | gfs2_glock_hold(gl); |
24264434 SW |
1424 | read_unlock(gl_lock_addr(hash)); |
1425 | if (prev) | |
1426 | gfs2_glock_put(prev); | |
1427 | prev = gl; | |
1428 | examiner(gl); | |
a8336344 | 1429 | has_entries = 1; |
24264434 | 1430 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1431 | } |
b6397893 SW |
1432 | if (gl->gl_list.next == NULL) |
1433 | break; | |
24264434 | 1434 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1435 | } |
24264434 SW |
1436 | out: |
1437 | read_unlock(gl_lock_addr(hash)); | |
1438 | if (prev) | |
1439 | gfs2_glock_put(prev); | |
8fbbfd21 | 1440 | cond_resched(); |
24264434 | 1441 | return has_entries; |
b3b94faa DT |
1442 | } |
1443 | ||
f057f6cd SW |
1444 | |
1445 | /** | |
1446 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1447 | * @gl: The glock to thaw | |
1448 | * | |
1449 | * N.B. When we freeze a glock, we leave a ref to the glock outstanding, | |
1450 | * so this has to result in the ref count being dropped by one. | |
1451 | */ | |
1452 | ||
1453 | static void thaw_glock(struct gfs2_glock *gl) | |
1454 | { | |
1455 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1456 | return; | |
f057f6cd SW |
1457 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1458 | gfs2_glock_hold(gl); | |
1459 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1460 | gfs2_glock_put(gl); | |
f057f6cd SW |
1461 | } |
1462 | ||
b3b94faa DT |
1463 | /** |
1464 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1465 | * @gl: the glock to look at | |
1466 | * | |
1467 | */ | |
1468 | ||
1469 | static void clear_glock(struct gfs2_glock *gl) | |
1470 | { | |
97cc1025 SW |
1471 | spin_lock(&lru_lock); |
1472 | if (!list_empty(&gl->gl_lru)) { | |
1473 | list_del_init(&gl->gl_lru); | |
1474 | atomic_dec(&lru_count); | |
b3b94faa | 1475 | } |
97cc1025 | 1476 | spin_unlock(&lru_lock); |
b3b94faa | 1477 | |
6802e340 SW |
1478 | spin_lock(&gl->gl_spin); |
1479 | if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED) | |
97cc1025 | 1480 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
6802e340 SW |
1481 | spin_unlock(&gl->gl_spin); |
1482 | gfs2_glock_hold(gl); | |
1483 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1484 | gfs2_glock_put(gl); | |
b3b94faa DT |
1485 | } |
1486 | ||
f057f6cd SW |
1487 | /** |
1488 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1489 | * @sdp: The super block | |
1490 | * | |
1491 | */ | |
1492 | ||
1493 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1494 | { | |
1495 | unsigned x; | |
1496 | ||
1497 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1498 | examine_bucket(thaw_glock, sdp, x); | |
1499 | } | |
1500 | ||
b3b94faa DT |
1501 | /** |
1502 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1503 | * @sdp: the filesystem | |
1504 | * @wait: wait until it's all gone | |
1505 | * | |
1bdad606 | 1506 | * Called when unmounting the filesystem. |
b3b94faa DT |
1507 | */ |
1508 | ||
fefc03bf | 1509 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa DT |
1510 | { |
1511 | unsigned long t; | |
1512 | unsigned int x; | |
1513 | int cont; | |
1514 | ||
1515 | t = jiffies; | |
1516 | ||
1517 | for (;;) { | |
1518 | cont = 0; | |
24264434 | 1519 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1520 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1521 | cont = 1; |
24264434 | 1522 | } |
b3b94faa | 1523 | |
1bdad606 | 1524 | if (!cont) |
b3b94faa DT |
1525 | break; |
1526 | ||
1527 | if (time_after_eq(jiffies, | |
1528 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1529 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1530 | "Dumping lock state...\n"); | |
1531 | gfs2_dump_lockstate(sdp); | |
1532 | t = jiffies; | |
1533 | } | |
1534 | ||
61be084e | 1535 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1536 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1537 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1538 | msleep(10); |
b3b94faa DT |
1539 | } |
1540 | } | |
1541 | ||
813e0c46 SW |
1542 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1543 | { | |
1544 | struct gfs2_glock *gl = ip->i_gl; | |
1545 | int ret; | |
1546 | ||
1547 | ret = gfs2_truncatei_resume(ip); | |
1548 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1549 | ||
1550 | spin_lock(&gl->gl_spin); | |
1551 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1552 | run_queue(gl, 1); | |
1553 | spin_unlock(&gl->gl_spin); | |
1554 | } | |
1555 | ||
6802e340 | 1556 | static const char *state2str(unsigned state) |
04b933f2 | 1557 | { |
6802e340 SW |
1558 | switch(state) { |
1559 | case LM_ST_UNLOCKED: | |
1560 | return "UN"; | |
1561 | case LM_ST_SHARED: | |
1562 | return "SH"; | |
1563 | case LM_ST_DEFERRED: | |
1564 | return "DF"; | |
1565 | case LM_ST_EXCLUSIVE: | |
1566 | return "EX"; | |
1567 | } | |
1568 | return "??"; | |
1569 | } | |
1570 | ||
1571 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1572 | { | |
1573 | char *p = buf; | |
1574 | if (flags & LM_FLAG_TRY) | |
1575 | *p++ = 't'; | |
1576 | if (flags & LM_FLAG_TRY_1CB) | |
1577 | *p++ = 'T'; | |
1578 | if (flags & LM_FLAG_NOEXP) | |
1579 | *p++ = 'e'; | |
1580 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1581 | *p++ = 'A'; |
6802e340 SW |
1582 | if (flags & LM_FLAG_PRIORITY) |
1583 | *p++ = 'p'; | |
1584 | if (flags & GL_ASYNC) | |
1585 | *p++ = 'a'; | |
1586 | if (flags & GL_EXACT) | |
1587 | *p++ = 'E'; | |
6802e340 SW |
1588 | if (flags & GL_NOCACHE) |
1589 | *p++ = 'c'; | |
1590 | if (test_bit(HIF_HOLDER, &iflags)) | |
1591 | *p++ = 'H'; | |
1592 | if (test_bit(HIF_WAIT, &iflags)) | |
1593 | *p++ = 'W'; | |
1594 | if (test_bit(HIF_FIRST, &iflags)) | |
1595 | *p++ = 'F'; | |
1596 | *p = 0; | |
1597 | return buf; | |
04b933f2 RP |
1598 | } |
1599 | ||
b3b94faa DT |
1600 | /** |
1601 | * dump_holder - print information about a glock holder | |
6802e340 | 1602 | * @seq: the seq_file struct |
b3b94faa DT |
1603 | * @gh: the glock holder |
1604 | * | |
1605 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1606 | */ | |
1607 | ||
6802e340 | 1608 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1609 | { |
6802e340 SW |
1610 | struct task_struct *gh_owner = NULL; |
1611 | char buffer[KSYM_SYMBOL_LEN]; | |
1612 | char flags_buf[32]; | |
b3b94faa | 1613 | |
6802e340 SW |
1614 | sprint_symbol(buffer, gh->gh_ip); |
1615 | if (gh->gh_owner_pid) | |
b1e058da | 1616 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
6802e340 SW |
1617 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", |
1618 | state2str(gh->gh_state), | |
1619 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1620 | gh->gh_error, | |
1621 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1622 | gh_owner ? gh_owner->comm : "(ended)", buffer); | |
7c52b166 | 1623 | return 0; |
b3b94faa DT |
1624 | } |
1625 | ||
6802e340 SW |
1626 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1627 | { | |
1628 | char *p = buf; | |
1629 | if (test_bit(GLF_LOCK, gflags)) | |
1630 | *p++ = 'l'; | |
6802e340 SW |
1631 | if (test_bit(GLF_DEMOTE, gflags)) |
1632 | *p++ = 'D'; | |
1633 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1634 | *p++ = 'd'; | |
1635 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1636 | *p++ = 'p'; | |
1637 | if (test_bit(GLF_DIRTY, gflags)) | |
1638 | *p++ = 'y'; | |
1639 | if (test_bit(GLF_LFLUSH, gflags)) | |
1640 | *p++ = 'f'; | |
1641 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1642 | *p++ = 'i'; | |
1643 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1644 | *p++ = 'r'; | |
f057f6cd | 1645 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1646 | *p++ = 'I'; |
f057f6cd SW |
1647 | if (test_bit(GLF_FROZEN, gflags)) |
1648 | *p++ = 'F'; | |
6802e340 SW |
1649 | *p = 0; |
1650 | return buf; | |
b3b94faa DT |
1651 | } |
1652 | ||
1653 | /** | |
6802e340 SW |
1654 | * __dump_glock - print information about a glock |
1655 | * @seq: The seq_file struct | |
b3b94faa | 1656 | * @gl: the glock |
6802e340 SW |
1657 | * |
1658 | * The file format is as follows: | |
1659 | * One line per object, capital letters are used to indicate objects | |
1660 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1661 | * other objects are indented by a single space and follow the glock to | |
1662 | * which they are related. Fields are indicated by lower case letters | |
1663 | * followed by a colon and the field value, except for strings which are in | |
1664 | * [] so that its possible to see if they are composed of spaces for | |
1665 | * example. The field's are n = number (id of the object), f = flags, | |
1666 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1667 | * |
1668 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1669 | */ | |
1670 | ||
6802e340 | 1671 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1672 | { |
6802e340 SW |
1673 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1674 | unsigned long long dtime; | |
1675 | const struct gfs2_holder *gh; | |
1676 | char gflags_buf[32]; | |
1677 | int error = 0; | |
b3b94faa | 1678 | |
6802e340 SW |
1679 | dtime = jiffies - gl->gl_demote_time; |
1680 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1681 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1682 | dtime = 0; | |
f057f6cd | 1683 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu a:%d r:%d\n", |
6802e340 SW |
1684 | state2str(gl->gl_state), |
1685 | gl->gl_name.ln_type, | |
1686 | (unsigned long long)gl->gl_name.ln_number, | |
1687 | gflags2str(gflags_buf, &gl->gl_flags), | |
1688 | state2str(gl->gl_target), | |
1689 | state2str(gl->gl_demote_state), dtime, | |
6802e340 SW |
1690 | atomic_read(&gl->gl_ail_count), |
1691 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1692 | |
b3b94faa | 1693 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1694 | error = dump_holder(seq, gh); |
b3b94faa DT |
1695 | if (error) |
1696 | goto out; | |
1697 | } | |
6802e340 SW |
1698 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1699 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1700 | out: |
b3b94faa DT |
1701 | return error; |
1702 | } | |
1703 | ||
6802e340 SW |
1704 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1705 | { | |
1706 | int ret; | |
1707 | spin_lock(&gl->gl_spin); | |
1708 | ret = __dump_glock(seq, gl); | |
1709 | spin_unlock(&gl->gl_spin); | |
1710 | return ret; | |
1711 | } | |
1712 | ||
b3b94faa DT |
1713 | /** |
1714 | * gfs2_dump_lockstate - print out the current lockstate | |
1715 | * @sdp: the filesystem | |
1716 | * @ub: the buffer to copy the information into | |
1717 | * | |
1718 | * If @ub is NULL, dump the lockstate to the console. | |
1719 | * | |
1720 | */ | |
1721 | ||
08bc2dbc | 1722 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1723 | { |
b3b94faa | 1724 | struct gfs2_glock *gl; |
b6397893 | 1725 | struct hlist_node *h; |
b3b94faa DT |
1726 | unsigned int x; |
1727 | int error = 0; | |
1728 | ||
1729 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1730 | |
087efdd3 | 1731 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1732 | |
b6397893 | 1733 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1734 | if (gl->gl_sbd != sdp) |
1735 | continue; | |
b3b94faa | 1736 | |
7c52b166 | 1737 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1738 | if (error) |
1739 | break; | |
1740 | } | |
1741 | ||
087efdd3 | 1742 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1743 | |
1744 | if (error) | |
1745 | break; | |
1746 | } | |
1747 | ||
1748 | ||
1749 | return error; | |
1750 | } | |
1751 | ||
8fbbfd21 | 1752 | |
85d1da67 SW |
1753 | int __init gfs2_glock_init(void) |
1754 | { | |
1755 | unsigned i; | |
1756 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1757 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1758 | } |
087efdd3 SW |
1759 | #ifdef GL_HASH_LOCK_SZ |
1760 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1761 | rwlock_init(&gl_hash_locks[i]); | |
1762 | } | |
1763 | #endif | |
8fbbfd21 | 1764 | |
c4f68a13 | 1765 | glock_workqueue = create_workqueue("glock_workqueue"); |
97cc1025 | 1766 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1767 | return PTR_ERR(glock_workqueue); |
b94a170e BM |
1768 | gfs2_delete_workqueue = create_workqueue("delete_workqueue"); |
1769 | if (IS_ERR(gfs2_delete_workqueue)) { | |
1770 | destroy_workqueue(glock_workqueue); | |
1771 | return PTR_ERR(gfs2_delete_workqueue); | |
1772 | } | |
97cc1025 SW |
1773 | |
1774 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1775 | |
85d1da67 SW |
1776 | return 0; |
1777 | } | |
1778 | ||
8fbbfd21 SW |
1779 | void gfs2_glock_exit(void) |
1780 | { | |
97cc1025 | 1781 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1782 | destroy_workqueue(glock_workqueue); |
b94a170e | 1783 | destroy_workqueue(gfs2_delete_workqueue); |
8fbbfd21 SW |
1784 | } |
1785 | ||
6802e340 | 1786 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1787 | { |
7b08fc62 SW |
1788 | struct gfs2_glock *gl; |
1789 | ||
a947e033 | 1790 | restart: |
7a0079d9 | 1791 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1792 | gl = gi->gl; |
1793 | if (gl) { | |
a947e033 AD |
1794 | gi->gl = hlist_entry(gl->gl_list.next, |
1795 | struct gfs2_glock, gl_list); | |
c1e817d0 SW |
1796 | } else { |
1797 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1798 | struct gfs2_glock, gl_list); | |
7c52b166 | 1799 | } |
c1e817d0 SW |
1800 | if (gi->gl) |
1801 | gfs2_glock_hold(gi->gl); | |
7a0079d9 | 1802 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1803 | if (gl) |
1804 | gfs2_glock_put(gl); | |
6802e340 | 1805 | while (gi->gl == NULL) { |
c1e817d0 | 1806 | gi->hash++; |
7b08fc62 SW |
1807 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
1808 | return 1; | |
1809 | read_lock(gl_lock_addr(gi->hash)); | |
1810 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1811 | struct gfs2_glock, gl_list); | |
1812 | if (gi->gl) | |
1813 | gfs2_glock_hold(gi->gl); | |
1814 | read_unlock(gl_lock_addr(gi->hash)); | |
1815 | } | |
a947e033 AD |
1816 | |
1817 | if (gi->sdp != gi->gl->gl_sbd) | |
1818 | goto restart; | |
1819 | ||
7c52b166 RP |
1820 | return 0; |
1821 | } | |
1822 | ||
6802e340 | 1823 | static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) |
7c52b166 | 1824 | { |
7b08fc62 SW |
1825 | if (gi->gl) |
1826 | gfs2_glock_put(gi->gl); | |
a947e033 | 1827 | gi->gl = NULL; |
7c52b166 RP |
1828 | } |
1829 | ||
6802e340 | 1830 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1831 | { |
6802e340 | 1832 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1833 | loff_t n = *pos; |
1834 | ||
6802e340 | 1835 | gi->hash = 0; |
7c52b166 | 1836 | |
6802e340 | 1837 | do { |
7c52b166 RP |
1838 | if (gfs2_glock_iter_next(gi)) { |
1839 | gfs2_glock_iter_free(gi); | |
1840 | return NULL; | |
1841 | } | |
6802e340 | 1842 | } while (n--); |
7c52b166 | 1843 | |
6802e340 | 1844 | return gi->gl; |
7c52b166 RP |
1845 | } |
1846 | ||
6802e340 | 1847 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1848 | loff_t *pos) |
1849 | { | |
6802e340 | 1850 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1851 | |
1852 | (*pos)++; | |
1853 | ||
1854 | if (gfs2_glock_iter_next(gi)) { | |
1855 | gfs2_glock_iter_free(gi); | |
1856 | return NULL; | |
1857 | } | |
1858 | ||
6802e340 | 1859 | return gi->gl; |
7c52b166 RP |
1860 | } |
1861 | ||
6802e340 | 1862 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1863 | { |
6802e340 SW |
1864 | struct gfs2_glock_iter *gi = seq->private; |
1865 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
1866 | } |
1867 | ||
6802e340 | 1868 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1869 | { |
6802e340 | 1870 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1871 | } |
1872 | ||
4ef29002 | 1873 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1874 | .start = gfs2_glock_seq_start, |
1875 | .next = gfs2_glock_seq_next, | |
1876 | .stop = gfs2_glock_seq_stop, | |
1877 | .show = gfs2_glock_seq_show, | |
1878 | }; | |
1879 | ||
1880 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1881 | { | |
6802e340 SW |
1882 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1883 | sizeof(struct gfs2_glock_iter)); | |
1884 | if (ret == 0) { | |
1885 | struct seq_file *seq = file->private_data; | |
1886 | struct gfs2_glock_iter *gi = seq->private; | |
1887 | gi->sdp = inode->i_private; | |
1888 | } | |
1889 | return ret; | |
7c52b166 RP |
1890 | } |
1891 | ||
1892 | static const struct file_operations gfs2_debug_fops = { | |
1893 | .owner = THIS_MODULE, | |
1894 | .open = gfs2_debugfs_open, | |
1895 | .read = seq_read, | |
1896 | .llseek = seq_lseek, | |
6802e340 | 1897 | .release = seq_release_private, |
7c52b166 RP |
1898 | }; |
1899 | ||
1900 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1901 | { | |
5f882096 RP |
1902 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1903 | if (!sdp->debugfs_dir) | |
1904 | return -ENOMEM; | |
1905 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1906 | S_IFREG | S_IRUGO, | |
1907 | sdp->debugfs_dir, sdp, | |
1908 | &gfs2_debug_fops); | |
1909 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1910 | return -ENOMEM; |
1911 | ||
1912 | return 0; | |
1913 | } | |
1914 | ||
1915 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1916 | { | |
5f882096 RP |
1917 | if (sdp && sdp->debugfs_dir) { |
1918 | if (sdp->debugfs_dentry_glocks) { | |
1919 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1920 | sdp->debugfs_dentry_glocks = NULL; | |
1921 | } | |
1922 | debugfs_remove(sdp->debugfs_dir); | |
1923 | sdp->debugfs_dir = NULL; | |
1924 | } | |
7c52b166 RP |
1925 | } |
1926 | ||
1927 | int gfs2_register_debugfs(void) | |
1928 | { | |
1929 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1930 | return gfs2_root ? 0 : -ENOMEM; | |
1931 | } | |
1932 | ||
1933 | void gfs2_unregister_debugfs(void) | |
1934 | { | |
1935 | debugfs_remove(gfs2_root); | |
5f882096 | 1936 | gfs2_root = NULL; |
7c52b166 | 1937 | } |