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> |
b3b94faa | 22 | #include <asm/uaccess.h> |
7c52b166 RP |
23 | #include <linux/seq_file.h> |
24 | #include <linux/debugfs.h> | |
8fbbfd21 SW |
25 | #include <linux/kthread.h> |
26 | #include <linux/freezer.h> | |
c4f68a13 BM |
27 | #include <linux/workqueue.h> |
28 | #include <linux/jiffies.h> | |
b3b94faa DT |
29 | |
30 | #include "gfs2.h" | |
5c676f6d | 31 | #include "incore.h" |
b3b94faa DT |
32 | #include "glock.h" |
33 | #include "glops.h" | |
34 | #include "inode.h" | |
b3b94faa DT |
35 | #include "lops.h" |
36 | #include "meta_io.h" | |
37 | #include "quota.h" | |
38 | #include "super.h" | |
5c676f6d | 39 | #include "util.h" |
813e0c46 | 40 | #include "bmap.h" |
63997775 SW |
41 | #define CREATE_TRACE_POINTS |
42 | #include "trace_gfs2.h" | |
b3b94faa | 43 | |
37b2fa6a | 44 | struct gfs2_gl_hash_bucket { |
b6397893 | 45 | struct hlist_head hb_list; |
37b2fa6a SW |
46 | }; |
47 | ||
6802e340 SW |
48 | struct gfs2_glock_iter { |
49 | int hash; /* hash bucket index */ | |
50 | struct gfs2_sbd *sdp; /* incore superblock */ | |
51 | struct gfs2_glock *gl; /* current glock struct */ | |
52 | char string[512]; /* scratch space */ | |
7c52b166 RP |
53 | }; |
54 | ||
b3b94faa DT |
55 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
56 | ||
08bc2dbc | 57 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); |
6802e340 SW |
58 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); |
59 | #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0) | |
60 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); | |
c4f68a13 | 61 | |
7c52b166 | 62 | static struct dentry *gfs2_root; |
c4f68a13 | 63 | static struct workqueue_struct *glock_workqueue; |
b94a170e | 64 | struct workqueue_struct *gfs2_delete_workqueue; |
97cc1025 SW |
65 | static LIST_HEAD(lru_list); |
66 | static atomic_t lru_count = ATOMIC_INIT(0); | |
eb8374e7 | 67 | static DEFINE_SPINLOCK(lru_lock); |
08bc2dbc | 68 | |
b6397893 | 69 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
70 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
71 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
72 | ||
85d1da67 | 73 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 74 | static struct dentry *gfs2_root; |
087efdd3 SW |
75 | |
76 | /* | |
77 | * Despite what you might think, the numbers below are not arbitrary :-) | |
78 | * They are taken from the ipv4 routing hash code, which is well tested | |
79 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
80 | * but for now this should be fine. | |
81 | * | |
82 | * The reason for putting the locks in a separate array from the list heads | |
83 | * is that we can have fewer locks than list heads and save memory. We use | |
84 | * the same hash function for both, but with a different hash mask. | |
85 | */ | |
86 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
87 | defined(CONFIG_PROVE_LOCKING) | |
88 | ||
89 | #ifdef CONFIG_LOCKDEP | |
90 | # define GL_HASH_LOCK_SZ 256 | |
91 | #else | |
92 | # if NR_CPUS >= 32 | |
93 | # define GL_HASH_LOCK_SZ 4096 | |
94 | # elif NR_CPUS >= 16 | |
95 | # define GL_HASH_LOCK_SZ 2048 | |
96 | # elif NR_CPUS >= 8 | |
97 | # define GL_HASH_LOCK_SZ 1024 | |
98 | # elif NR_CPUS >= 4 | |
99 | # define GL_HASH_LOCK_SZ 512 | |
100 | # else | |
101 | # define GL_HASH_LOCK_SZ 256 | |
102 | # endif | |
103 | #endif | |
104 | ||
105 | /* We never want more locks than chains */ | |
106 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
107 | # undef GL_HASH_LOCK_SZ | |
108 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
109 | #endif | |
110 | ||
111 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
112 | ||
113 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
114 | { | |
94610610 | 115 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
116 | } |
117 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 118 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
119 | { |
120 | return NULL; | |
121 | } | |
122 | #endif | |
85d1da67 | 123 | |
b3b94faa DT |
124 | /** |
125 | * gl_hash() - Turn glock number into hash bucket number | |
126 | * @lock: The glock number | |
127 | * | |
128 | * Returns: The number of the corresponding hash bucket | |
129 | */ | |
130 | ||
b8547856 SW |
131 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
132 | const struct lm_lockname *name) | |
b3b94faa DT |
133 | { |
134 | unsigned int h; | |
135 | ||
cd915493 | 136 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 137 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 138 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
139 | h &= GFS2_GL_HASH_MASK; |
140 | ||
141 | return h; | |
142 | } | |
143 | ||
144 | /** | |
145 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
146 | * @gl: The glock to release | |
147 | * | |
148 | * Also calls lock module to release its internal structure for this glock. | |
149 | * | |
150 | */ | |
151 | ||
152 | static void glock_free(struct gfs2_glock *gl) | |
153 | { | |
154 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
009d8518 SW |
155 | struct address_space *mapping = gfs2_glock2aspace(gl); |
156 | struct kmem_cache *cachep = gfs2_glock_cachep; | |
b3b94faa | 157 | |
009d8518 | 158 | GLOCK_BUG_ON(gl, mapping && mapping->nrpages); |
63997775 | 159 | trace_gfs2_glock_put(gl); |
009d8518 SW |
160 | if (mapping) |
161 | cachep = gfs2_glock_aspace_cachep; | |
162 | sdp->sd_lockstruct.ls_ops->lm_put_lock(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)); |
26bb7505 | 244 | if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) { |
b6397893 | 245 | hlist_del(&gl->gl_list); |
97cc1025 SW |
246 | if (!list_empty(&gl->gl_lru)) { |
247 | list_del_init(&gl->gl_lru); | |
248 | atomic_dec(&lru_count); | |
249 | } | |
250 | spin_unlock(&lru_lock); | |
26bb7505 | 251 | write_unlock(gl_lock_addr(gl->gl_hash)); |
6802e340 | 252 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
b3b94faa DT |
253 | glock_free(gl); |
254 | rv = 1; | |
255 | goto out; | |
256 | } | |
8ff22a6f BM |
257 | spin_lock(&gl->gl_spin); |
258 | gfs2_glock_schedule_for_reclaim(gl); | |
259 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 260 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 261 | out: |
b3b94faa DT |
262 | return rv; |
263 | } | |
264 | ||
b3b94faa DT |
265 | /** |
266 | * search_bucket() - Find struct gfs2_glock by lock number | |
267 | * @bucket: the bucket to search | |
268 | * @name: The lock name | |
269 | * | |
270 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
271 | */ | |
272 | ||
37b2fa6a | 273 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 274 | const struct gfs2_sbd *sdp, |
d6a53727 | 275 | const struct lm_lockname *name) |
b3b94faa DT |
276 | { |
277 | struct gfs2_glock *gl; | |
b6397893 | 278 | struct hlist_node *h; |
b3b94faa | 279 | |
b6397893 | 280 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
281 | if (!lm_name_equal(&gl->gl_name, name)) |
282 | continue; | |
899be4d3 SW |
283 | if (gl->gl_sbd != sdp) |
284 | continue; | |
b3b94faa | 285 | |
16feb9fe | 286 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
287 | |
288 | return gl; | |
289 | } | |
290 | ||
291 | return NULL; | |
292 | } | |
293 | ||
6802e340 SW |
294 | /** |
295 | * may_grant - check if its ok to grant a new lock | |
296 | * @gl: The glock | |
297 | * @gh: The lock request which we wish to grant | |
298 | * | |
299 | * Returns: true if its ok to grant the lock | |
300 | */ | |
301 | ||
302 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
303 | { | |
304 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
305 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
306 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
307 | return 0; | |
308 | if (gl->gl_state == gh->gh_state) | |
309 | return 1; | |
310 | if (gh->gh_flags & GL_EXACT) | |
311 | return 0; | |
209806ab SW |
312 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
313 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
314 | return 1; | |
315 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
316 | return 1; | |
317 | } | |
6802e340 SW |
318 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
319 | return 1; | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
324 | { | |
325 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
326 | smp_mb__after_clear_bit(); | |
327 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
328 | } | |
329 | ||
330 | /** | |
331 | * do_promote - promote as many requests as possible on the current queue | |
332 | * @gl: The glock | |
333 | * | |
813e0c46 SW |
334 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
335 | * if a type specific operation is underway. | |
6802e340 SW |
336 | */ |
337 | ||
338 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
339 | __releases(&gl->gl_spin) |
340 | __acquires(&gl->gl_spin) | |
6802e340 SW |
341 | { |
342 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
343 | struct gfs2_holder *gh, *tmp; | |
344 | int ret; | |
345 | ||
346 | restart: | |
347 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
348 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
349 | continue; | |
350 | if (may_grant(gl, gh)) { | |
351 | if (gh->gh_list.prev == &gl->gl_holders && | |
352 | glops->go_lock) { | |
353 | spin_unlock(&gl->gl_spin); | |
354 | /* FIXME: eliminate this eventually */ | |
355 | ret = glops->go_lock(gh); | |
356 | spin_lock(&gl->gl_spin); | |
357 | if (ret) { | |
813e0c46 SW |
358 | if (ret == 1) |
359 | return 2; | |
6802e340 SW |
360 | gh->gh_error = ret; |
361 | list_del_init(&gh->gh_list); | |
63997775 | 362 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
363 | gfs2_holder_wake(gh); |
364 | goto restart; | |
365 | } | |
366 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 367 | trace_gfs2_promote(gh, 1); |
6802e340 SW |
368 | gfs2_holder_wake(gh); |
369 | goto restart; | |
370 | } | |
371 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 372 | trace_gfs2_promote(gh, 0); |
6802e340 SW |
373 | gfs2_holder_wake(gh); |
374 | continue; | |
375 | } | |
376 | if (gh->gh_list.prev == &gl->gl_holders) | |
377 | return 1; | |
378 | break; | |
379 | } | |
380 | return 0; | |
381 | } | |
382 | ||
383 | /** | |
384 | * do_error - Something unexpected has happened during a lock request | |
385 | * | |
386 | */ | |
387 | ||
388 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
389 | { | |
390 | struct gfs2_holder *gh, *tmp; | |
391 | ||
392 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
393 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
394 | continue; | |
395 | if (ret & LM_OUT_ERROR) | |
396 | gh->gh_error = -EIO; | |
397 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
398 | gh->gh_error = GLR_TRYFAILED; | |
399 | else | |
400 | continue; | |
401 | list_del_init(&gh->gh_list); | |
63997775 | 402 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
403 | gfs2_holder_wake(gh); |
404 | } | |
405 | } | |
406 | ||
407 | /** | |
408 | * find_first_waiter - find the first gh that's waiting for the glock | |
409 | * @gl: the glock | |
410 | */ | |
411 | ||
412 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
413 | { | |
414 | struct gfs2_holder *gh; | |
415 | ||
416 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
417 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
418 | return gh; | |
419 | } | |
420 | return NULL; | |
421 | } | |
422 | ||
423 | /** | |
424 | * state_change - record that the glock is now in a different state | |
425 | * @gl: the glock | |
426 | * @new_state the new state | |
427 | * | |
428 | */ | |
429 | ||
430 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
431 | { | |
432 | int held1, held2; | |
433 | ||
434 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
435 | held2 = (new_state != LM_ST_UNLOCKED); | |
436 | ||
437 | if (held1 != held2) { | |
438 | if (held2) | |
439 | gfs2_glock_hold(gl); | |
440 | else | |
8ff22a6f | 441 | gfs2_glock_put_nolock(gl); |
6802e340 SW |
442 | } |
443 | ||
444 | gl->gl_state = new_state; | |
445 | gl->gl_tchange = jiffies; | |
446 | } | |
447 | ||
448 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
449 | { | |
450 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
451 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
452 | smp_mb__after_clear_bit(); | |
453 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
454 | } | |
455 | ||
456 | /** | |
457 | * finish_xmote - The DLM has replied to one of our lock requests | |
458 | * @gl: The glock | |
459 | * @ret: The status from the DLM | |
460 | * | |
461 | */ | |
462 | ||
463 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
464 | { | |
465 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
466 | struct gfs2_holder *gh; | |
467 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 468 | int rv; |
6802e340 SW |
469 | |
470 | spin_lock(&gl->gl_spin); | |
63997775 | 471 | trace_gfs2_glock_state_change(gl, state); |
6802e340 SW |
472 | state_change(gl, state); |
473 | gh = find_first_waiter(gl); | |
474 | ||
475 | /* Demote to UN request arrived during demote to SH or DF */ | |
476 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
477 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
478 | gl->gl_target = LM_ST_UNLOCKED; | |
479 | ||
480 | /* Check for state != intended state */ | |
481 | if (unlikely(state != gl->gl_target)) { | |
482 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
483 | /* move to back of queue and try next entry */ | |
484 | if (ret & LM_OUT_CANCELED) { | |
485 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
486 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
487 | gh = find_first_waiter(gl); | |
488 | gl->gl_target = gh->gh_state; | |
489 | goto retry; | |
490 | } | |
491 | /* Some error or failed "try lock" - report it */ | |
492 | if ((ret & LM_OUT_ERROR) || | |
493 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
494 | gl->gl_target = gl->gl_state; | |
495 | do_error(gl, ret); | |
496 | goto out; | |
497 | } | |
498 | } | |
499 | switch(state) { | |
500 | /* Unlocked due to conversion deadlock, try again */ | |
501 | case LM_ST_UNLOCKED: | |
502 | retry: | |
503 | do_xmote(gl, gh, gl->gl_target); | |
504 | break; | |
505 | /* Conversion fails, unlock and try again */ | |
506 | case LM_ST_SHARED: | |
507 | case LM_ST_DEFERRED: | |
508 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
509 | break; | |
510 | default: /* Everything else */ | |
511 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
512 | GLOCK_BUG_ON(gl, 1); | |
513 | } | |
514 | spin_unlock(&gl->gl_spin); | |
6802e340 SW |
515 | return; |
516 | } | |
517 | ||
518 | /* Fast path - we got what we asked for */ | |
519 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
520 | gfs2_demote_wake(gl); | |
521 | if (state != LM_ST_UNLOCKED) { | |
522 | if (glops->go_xmote_bh) { | |
6802e340 SW |
523 | spin_unlock(&gl->gl_spin); |
524 | rv = glops->go_xmote_bh(gl, gh); | |
6802e340 SW |
525 | spin_lock(&gl->gl_spin); |
526 | if (rv) { | |
527 | do_error(gl, rv); | |
528 | goto out; | |
529 | } | |
530 | } | |
813e0c46 SW |
531 | rv = do_promote(gl); |
532 | if (rv == 2) | |
533 | goto out_locked; | |
6802e340 SW |
534 | } |
535 | out: | |
536 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 537 | out_locked: |
6802e340 | 538 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
539 | } |
540 | ||
541 | static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, | |
f057f6cd | 542 | unsigned int req_state, |
6802e340 SW |
543 | unsigned int flags) |
544 | { | |
545 | int ret = LM_OUT_ERROR; | |
048bca22 SW |
546 | |
547 | if (!sdp->sd_lockstruct.ls_ops->lm_lock) | |
548 | return req_state == LM_ST_UNLOCKED ? 0 : req_state; | |
549 | ||
6802e340 | 550 | if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
f057f6cd | 551 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, |
6802e340 SW |
552 | req_state, flags); |
553 | return ret; | |
554 | } | |
555 | ||
556 | /** | |
557 | * do_xmote - Calls the DLM to change the state of a lock | |
558 | * @gl: The lock state | |
559 | * @gh: The holder (only for promotes) | |
560 | * @target: The target lock state | |
561 | * | |
562 | */ | |
563 | ||
564 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
565 | __releases(&gl->gl_spin) |
566 | __acquires(&gl->gl_spin) | |
6802e340 SW |
567 | { |
568 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
569 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
570 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
571 | int ret; | |
572 | ||
573 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
574 | LM_FLAG_PRIORITY); | |
575 | BUG_ON(gl->gl_state == target); | |
576 | BUG_ON(gl->gl_state == gl->gl_target); | |
577 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && | |
578 | glops->go_inval) { | |
579 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
580 | do_error(gl, 0); /* Fail queued try locks */ | |
581 | } | |
582 | spin_unlock(&gl->gl_spin); | |
583 | if (glops->go_xmote_th) | |
584 | glops->go_xmote_th(gl); | |
585 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
586 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
587 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
588 | ||
589 | gfs2_glock_hold(gl); | |
590 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
591 | gl->gl_state == LM_ST_DEFERRED) && | |
592 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
593 | lck_flags |= LM_FLAG_TRY_1CB; | |
f057f6cd | 594 | ret = gfs2_lm_lock(sdp, gl, target, lck_flags); |
6802e340 SW |
595 | |
596 | if (!(ret & LM_OUT_ASYNC)) { | |
597 | finish_xmote(gl, ret); | |
6802e340 SW |
598 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
599 | gfs2_glock_put(gl); | |
600 | } else { | |
601 | GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); | |
602 | } | |
603 | spin_lock(&gl->gl_spin); | |
604 | } | |
605 | ||
606 | /** | |
607 | * find_first_holder - find the first "holder" gh | |
608 | * @gl: the glock | |
609 | */ | |
610 | ||
611 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
612 | { | |
613 | struct gfs2_holder *gh; | |
614 | ||
615 | if (!list_empty(&gl->gl_holders)) { | |
616 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
617 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
618 | return gh; | |
619 | } | |
620 | return NULL; | |
621 | } | |
622 | ||
623 | /** | |
624 | * run_queue - do all outstanding tasks related to a glock | |
625 | * @gl: The glock in question | |
626 | * @nonblock: True if we must not block in run_queue | |
627 | * | |
628 | */ | |
629 | ||
630 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
631 | __releases(&gl->gl_spin) |
632 | __acquires(&gl->gl_spin) | |
6802e340 SW |
633 | { |
634 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 635 | int ret; |
6802e340 SW |
636 | |
637 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
638 | return; | |
639 | ||
640 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
641 | ||
642 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
643 | gl->gl_demote_state != gl->gl_state) { | |
644 | if (find_first_holder(gl)) | |
d8348de0 | 645 | goto out_unlock; |
6802e340 SW |
646 | if (nonblock) |
647 | goto out_sched; | |
648 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 649 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
650 | gl->gl_target = gl->gl_demote_state; |
651 | } else { | |
652 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
653 | gfs2_demote_wake(gl); | |
813e0c46 SW |
654 | ret = do_promote(gl); |
655 | if (ret == 0) | |
d8348de0 | 656 | goto out_unlock; |
813e0c46 | 657 | if (ret == 2) |
a228df63 | 658 | goto out; |
6802e340 SW |
659 | gh = find_first_waiter(gl); |
660 | gl->gl_target = gh->gh_state; | |
661 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
662 | do_error(gl, 0); /* Fail queued try locks */ | |
663 | } | |
664 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 665 | out: |
6802e340 SW |
666 | return; |
667 | ||
668 | out_sched: | |
7e71c55e SW |
669 | clear_bit(GLF_LOCK, &gl->gl_flags); |
670 | smp_mb__after_clear_bit(); | |
6802e340 SW |
671 | gfs2_glock_hold(gl); |
672 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
8ff22a6f | 673 | gfs2_glock_put_nolock(gl); |
7e71c55e SW |
674 | return; |
675 | ||
d8348de0 | 676 | out_unlock: |
6802e340 | 677 | clear_bit(GLF_LOCK, &gl->gl_flags); |
7e71c55e SW |
678 | smp_mb__after_clear_bit(); |
679 | return; | |
6802e340 SW |
680 | } |
681 | ||
b94a170e BM |
682 | static void delete_work_func(struct work_struct *work) |
683 | { | |
684 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); | |
685 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
686 | struct gfs2_inode *ip = NULL; | |
687 | struct inode *inode; | |
688 | u64 no_addr = 0; | |
689 | ||
690 | spin_lock(&gl->gl_spin); | |
691 | ip = (struct gfs2_inode *)gl->gl_object; | |
692 | if (ip) | |
693 | no_addr = ip->i_no_addr; | |
694 | spin_unlock(&gl->gl_spin); | |
695 | if (ip) { | |
696 | inode = gfs2_ilookup(sdp->sd_vfs, no_addr); | |
697 | if (inode) { | |
698 | d_prune_aliases(inode); | |
699 | iput(inode); | |
700 | } | |
701 | } | |
702 | gfs2_glock_put(gl); | |
703 | } | |
704 | ||
c4f68a13 BM |
705 | static void glock_work_func(struct work_struct *work) |
706 | { | |
6802e340 | 707 | unsigned long delay = 0; |
c4f68a13 | 708 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
26bb7505 | 709 | int drop_ref = 0; |
c4f68a13 | 710 | |
26bb7505 | 711 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
6802e340 | 712 | finish_xmote(gl, gl->gl_reply); |
26bb7505 SW |
713 | drop_ref = 1; |
714 | } | |
c4f68a13 | 715 | spin_lock(&gl->gl_spin); |
265d529c SW |
716 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
717 | gl->gl_state != LM_ST_UNLOCKED && | |
718 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
719 | unsigned long holdtime, now = jiffies; |
720 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
721 | if (time_before(now, holdtime)) | |
722 | delay = holdtime - now; | |
723 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
724 | } | |
725 | run_queue(gl, 0); | |
c4f68a13 | 726 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
727 | if (!delay || |
728 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
729 | gfs2_glock_put(gl); | |
26bb7505 SW |
730 | if (drop_ref) |
731 | gfs2_glock_put(gl); | |
c4f68a13 BM |
732 | } |
733 | ||
b3b94faa DT |
734 | /** |
735 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
736 | * @sdp: The GFS2 superblock | |
737 | * @number: the lock number | |
738 | * @glops: The glock_operations to use | |
739 | * @create: If 0, don't create the glock if it doesn't exist | |
740 | * @glp: the glock is returned here | |
741 | * | |
742 | * This does not lock a glock, just finds/creates structures for one. | |
743 | * | |
744 | * Returns: errno | |
745 | */ | |
746 | ||
cd915493 | 747 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 748 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
749 | struct gfs2_glock **glp) |
750 | { | |
009d8518 | 751 | struct super_block *s = sdp->sd_vfs; |
37b2fa6a | 752 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 753 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 754 | unsigned int hash = gl_hash(sdp, &name); |
009d8518 | 755 | struct address_space *mapping; |
b3b94faa | 756 | |
087efdd3 | 757 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 758 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 759 | read_unlock(gl_lock_addr(hash)); |
b3b94faa | 760 | |
64d576ba SW |
761 | *glp = gl; |
762 | if (gl) | |
b3b94faa | 763 | return 0; |
64d576ba SW |
764 | if (!create) |
765 | return -ENOENT; | |
b3b94faa | 766 | |
009d8518 SW |
767 | if (glops->go_flags & GLOF_ASPACE) |
768 | gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL); | |
769 | else | |
770 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
b3b94faa DT |
771 | if (!gl) |
772 | return -ENOMEM; | |
773 | ||
8f05228e | 774 | atomic_inc(&sdp->sd_glock_disposal); |
ec45d9f5 | 775 | gl->gl_flags = 0; |
b3b94faa | 776 | gl->gl_name = name; |
16feb9fe | 777 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 778 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 779 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 780 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 781 | gl->gl_hash = hash; |
b3b94faa | 782 | gl->gl_ops = glops; |
f057f6cd SW |
783 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
784 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
785 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 786 | gl->gl_tchange = jiffies; |
ec45d9f5 | 787 | gl->gl_object = NULL; |
b3b94faa | 788 | gl->gl_sbd = sdp; |
c4f68a13 | 789 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b94a170e | 790 | INIT_WORK(&gl->gl_delete, delete_work_func); |
b3b94faa | 791 | |
009d8518 SW |
792 | mapping = gfs2_glock2aspace(gl); |
793 | if (mapping) { | |
794 | mapping->a_ops = &gfs2_meta_aops; | |
795 | mapping->host = s->s_bdev->bd_inode; | |
796 | mapping->flags = 0; | |
797 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
798 | mapping->assoc_mapping = NULL; | |
799 | mapping->backing_dev_info = s->s_bdi; | |
800 | mapping->writeback_index = 0; | |
b3b94faa DT |
801 | } |
802 | ||
087efdd3 | 803 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 804 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 805 | if (tmp) { |
087efdd3 | 806 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
807 | glock_free(gl); |
808 | gl = tmp; | |
809 | } else { | |
b6397893 | 810 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 811 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
812 | } |
813 | ||
814 | *glp = gl; | |
815 | ||
816 | return 0; | |
b3b94faa DT |
817 | } |
818 | ||
819 | /** | |
820 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
821 | * @gl: the glock | |
822 | * @state: the state we're requesting | |
823 | * @flags: the modifier flags | |
824 | * @gh: the holder structure | |
825 | * | |
826 | */ | |
827 | ||
190562bd | 828 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
829 | struct gfs2_holder *gh) |
830 | { | |
831 | INIT_LIST_HEAD(&gh->gh_list); | |
832 | gh->gh_gl = gl; | |
d0dc80db | 833 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 834 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
835 | gh->gh_state = state; |
836 | gh->gh_flags = flags; | |
837 | gh->gh_error = 0; | |
838 | gh->gh_iflags = 0; | |
b3b94faa DT |
839 | gfs2_glock_hold(gl); |
840 | } | |
841 | ||
842 | /** | |
843 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
844 | * @state: the state we're requesting | |
845 | * @flags: the modifier flags | |
846 | * @gh: the holder structure | |
847 | * | |
848 | * Don't mess with the glock. | |
849 | * | |
850 | */ | |
851 | ||
190562bd | 852 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
853 | { |
854 | gh->gh_state = state; | |
579b78a4 | 855 | gh->gh_flags = flags; |
3b8249f6 | 856 | gh->gh_iflags = 0; |
d0dc80db | 857 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
858 | } |
859 | ||
860 | /** | |
861 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
862 | * @gh: the holder structure | |
863 | * | |
864 | */ | |
865 | ||
866 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
867 | { | |
b1e058da | 868 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
869 | gfs2_glock_put(gh->gh_gl); |
870 | gh->gh_gl = NULL; | |
d0dc80db | 871 | gh->gh_ip = 0; |
b3b94faa DT |
872 | } |
873 | ||
fe64d517 SW |
874 | /** |
875 | * gfs2_glock_holder_wait | |
876 | * @word: unused | |
877 | * | |
878 | * This function and gfs2_glock_demote_wait both show up in the WCHAN | |
879 | * field. Thus I've separated these otherwise identical functions in | |
880 | * order to be more informative to the user. | |
881 | */ | |
882 | ||
883 | static int gfs2_glock_holder_wait(void *word) | |
fee852e3 SW |
884 | { |
885 | schedule(); | |
886 | return 0; | |
887 | } | |
888 | ||
fe64d517 SW |
889 | static int gfs2_glock_demote_wait(void *word) |
890 | { | |
891 | schedule(); | |
892 | return 0; | |
893 | } | |
894 | ||
6802e340 | 895 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 896 | { |
6802e340 | 897 | might_sleep(); |
fe64d517 | 898 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
da755fdb SW |
899 | } |
900 | ||
6802e340 | 901 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 902 | { |
6802e340 | 903 | might_sleep(); |
fe64d517 | 904 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
b3b94faa DT |
905 | } |
906 | ||
907 | /** | |
6802e340 SW |
908 | * handle_callback - process a demote request |
909 | * @gl: the glock | |
910 | * @state: the state the caller wants us to change to | |
b3b94faa | 911 | * |
6802e340 SW |
912 | * There are only two requests that we are going to see in actual |
913 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
914 | */ |
915 | ||
6802e340 | 916 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 917 | unsigned long delay) |
b3b94faa | 918 | { |
6802e340 | 919 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 920 | |
6802e340 SW |
921 | set_bit(bit, &gl->gl_flags); |
922 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
923 | gl->gl_demote_state = state; | |
924 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
925 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
926 | gl->gl_demote_state != state) { | |
927 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 928 | } |
b94a170e BM |
929 | if (gl->gl_ops->go_callback) |
930 | gl->gl_ops->go_callback(gl); | |
63997775 | 931 | trace_gfs2_demote_rq(gl); |
b3b94faa DT |
932 | } |
933 | ||
934 | /** | |
6802e340 | 935 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
936 | * @gh: the glock holder |
937 | * | |
938 | * Returns: 0 on success | |
939 | */ | |
940 | ||
6802e340 | 941 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 942 | { |
fee852e3 | 943 | wait_on_holder(gh); |
b3b94faa DT |
944 | return gh->gh_error; |
945 | } | |
946 | ||
6802e340 | 947 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 RP |
948 | { |
949 | va_list args; | |
950 | ||
951 | va_start(args, fmt); | |
6802e340 SW |
952 | if (seq) { |
953 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 954 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
955 | seq_printf(seq, gi->string); |
956 | } else { | |
957 | printk(KERN_ERR " "); | |
7c52b166 | 958 | vprintk(fmt, args); |
6802e340 | 959 | } |
7c52b166 RP |
960 | va_end(args); |
961 | } | |
962 | ||
b3b94faa DT |
963 | /** |
964 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
965 | * @gh: the holder structure to add | |
966 | * | |
6802e340 SW |
967 | * Eventually we should move the recursive locking trap to a |
968 | * debugging option or something like that. This is the fast | |
969 | * path and needs to have the minimum number of distractions. | |
970 | * | |
b3b94faa DT |
971 | */ |
972 | ||
6802e340 | 973 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
974 | __releases(&gl->gl_spin) |
975 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
976 | { |
977 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
978 | struct gfs2_sbd *sdp = gl->gl_sbd; |
979 | struct list_head *insert_pt = NULL; | |
980 | struct gfs2_holder *gh2; | |
981 | int try_lock = 0; | |
b3b94faa | 982 | |
b1e058da | 983 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
984 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
985 | BUG(); | |
190562bd | 986 | |
6802e340 SW |
987 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
988 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
989 | try_lock = 1; | |
990 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
991 | goto fail; | |
992 | } | |
993 | ||
994 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
995 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
996 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
997 | goto trap_recursive; | |
998 | if (try_lock && | |
999 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
1000 | !may_grant(gl, gh)) { | |
1001 | fail: | |
1002 | gh->gh_error = GLR_TRYFAILED; | |
1003 | gfs2_holder_wake(gh); | |
1004 | return; | |
b4c20166 | 1005 | } |
6802e340 SW |
1006 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
1007 | continue; | |
1008 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
1009 | insert_pt = &gh2->gh_list; | |
1010 | } | |
1011 | if (likely(insert_pt == NULL)) { | |
1012 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
1013 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
1014 | goto do_cancel; | |
1015 | return; | |
1016 | } | |
63997775 | 1017 | trace_gfs2_glock_queue(gh, 1); |
6802e340 SW |
1018 | list_add_tail(&gh->gh_list, insert_pt); |
1019 | do_cancel: | |
1020 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
1021 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
1022 | spin_unlock(&gl->gl_spin); | |
048bca22 | 1023 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 1024 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 1025 | spin_lock(&gl->gl_spin); |
b3b94faa | 1026 | } |
6802e340 | 1027 | return; |
b3b94faa | 1028 | |
6802e340 SW |
1029 | trap_recursive: |
1030 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
1031 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
1032 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1033 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
1034 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
1035 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
1036 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1037 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
1038 | __dump_glock(NULL, gl); | |
1039 | BUG(); | |
b3b94faa DT |
1040 | } |
1041 | ||
1042 | /** | |
1043 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1044 | * @gh: the holder structure | |
1045 | * | |
1046 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1047 | * | |
1048 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1049 | */ | |
1050 | ||
1051 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1052 | { | |
1053 | struct gfs2_glock *gl = gh->gh_gl; | |
1054 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1055 | int error = 0; | |
1056 | ||
6802e340 | 1057 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 1058 | return -EIO; |
b3b94faa | 1059 | |
b3b94faa DT |
1060 | spin_lock(&gl->gl_spin); |
1061 | add_to_queue(gh); | |
6802e340 | 1062 | run_queue(gl, 1); |
b3b94faa DT |
1063 | spin_unlock(&gl->gl_spin); |
1064 | ||
6802e340 SW |
1065 | if (!(gh->gh_flags & GL_ASYNC)) |
1066 | error = gfs2_glock_wait(gh); | |
b3b94faa | 1067 | |
b3b94faa DT |
1068 | return error; |
1069 | } | |
1070 | ||
1071 | /** | |
1072 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1073 | * @gh: the holder | |
1074 | * | |
1075 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1076 | */ | |
1077 | ||
1078 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1079 | { | |
6802e340 | 1080 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1081 | } |
1082 | ||
1083 | /** | |
1084 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1085 | * @gh: the glock holder | |
1086 | * | |
1087 | */ | |
1088 | ||
1089 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1090 | { | |
1091 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1092 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1093 | unsigned delay = 0; |
6802e340 | 1094 | int fast_path = 0; |
b3b94faa | 1095 | |
6802e340 | 1096 | spin_lock(&gl->gl_spin); |
b3b94faa | 1097 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1098 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1099 | |
b3b94faa | 1100 | list_del_init(&gh->gh_list); |
6802e340 | 1101 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1102 | if (glops->go_unlock) { |
6802e340 | 1103 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1104 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1105 | glops->go_unlock(gh); |
3042a2cc | 1106 | spin_lock(&gl->gl_spin); |
6802e340 | 1107 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1108 | } |
6802e340 SW |
1109 | if (list_empty(&gl->gl_holders) && |
1110 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1111 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1112 | fast_path = 1; | |
b3b94faa | 1113 | } |
63997775 | 1114 | trace_gfs2_glock_queue(gh, 0); |
b3b94faa | 1115 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1116 | if (likely(fast_path)) |
1117 | return; | |
c4f68a13 BM |
1118 | |
1119 | gfs2_glock_hold(gl); | |
1120 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1121 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1122 | delay = gl->gl_ops->go_min_hold_time; | |
1123 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1124 | gfs2_glock_put(gl); | |
b3b94faa DT |
1125 | } |
1126 | ||
d93cfa98 AD |
1127 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1128 | { | |
1129 | struct gfs2_glock *gl = gh->gh_gl; | |
1130 | gfs2_glock_dq(gh); | |
1131 | wait_on_demote(gl); | |
1132 | } | |
1133 | ||
b3b94faa DT |
1134 | /** |
1135 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1136 | * @gh: the holder structure | |
1137 | * | |
1138 | */ | |
1139 | ||
1140 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1141 | { | |
1142 | gfs2_glock_dq(gh); | |
1143 | gfs2_holder_uninit(gh); | |
1144 | } | |
1145 | ||
1146 | /** | |
1147 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1148 | * @sdp: the filesystem | |
1149 | * @number: the lock number | |
1150 | * @glops: the glock operations for the type of glock | |
1151 | * @state: the state to acquire the glock in | |
1152 | * @flags: modifier flags for the aquisition | |
1153 | * @gh: the struct gfs2_holder | |
1154 | * | |
1155 | * Returns: errno | |
1156 | */ | |
1157 | ||
cd915493 | 1158 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1159 | const struct gfs2_glock_operations *glops, |
1160 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1161 | { |
1162 | struct gfs2_glock *gl; | |
1163 | int error; | |
1164 | ||
1165 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1166 | if (!error) { | |
1167 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1168 | gfs2_glock_put(gl); | |
1169 | } | |
1170 | ||
1171 | return error; | |
1172 | } | |
1173 | ||
1174 | /** | |
1175 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1176 | * @arg_a: the first structure | |
1177 | * @arg_b: the second structure | |
1178 | * | |
1179 | */ | |
1180 | ||
1181 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1182 | { | |
a5e08a9e SW |
1183 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1184 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1185 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1186 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1187 | |
1188 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1189 | return 1; |
1190 | if (a->ln_number < b->ln_number) | |
1191 | return -1; | |
1c0f4872 | 1192 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1193 | return 0; |
b3b94faa DT |
1194 | } |
1195 | ||
1196 | /** | |
1197 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1198 | * @num_gh: the number of structures | |
1199 | * @ghs: an array of struct gfs2_holder structures | |
1200 | * | |
1201 | * Returns: 0 on success (all glocks acquired), | |
1202 | * errno on failure (no glocks acquired) | |
1203 | */ | |
1204 | ||
1205 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1206 | struct gfs2_holder **p) | |
1207 | { | |
1208 | unsigned int x; | |
1209 | int error = 0; | |
1210 | ||
1211 | for (x = 0; x < num_gh; x++) | |
1212 | p[x] = &ghs[x]; | |
1213 | ||
1214 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1215 | ||
1216 | for (x = 0; x < num_gh; x++) { | |
1217 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1218 | ||
1219 | error = gfs2_glock_nq(p[x]); | |
1220 | if (error) { | |
1221 | while (x--) | |
1222 | gfs2_glock_dq(p[x]); | |
1223 | break; | |
1224 | } | |
1225 | } | |
1226 | ||
1227 | return error; | |
1228 | } | |
1229 | ||
1230 | /** | |
1231 | * gfs2_glock_nq_m - acquire multiple glocks | |
1232 | * @num_gh: the number of structures | |
1233 | * @ghs: an array of struct gfs2_holder structures | |
1234 | * | |
b3b94faa DT |
1235 | * |
1236 | * Returns: 0 on success (all glocks acquired), | |
1237 | * errno on failure (no glocks acquired) | |
1238 | */ | |
1239 | ||
1240 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1241 | { | |
eaf5bd3c SW |
1242 | struct gfs2_holder *tmp[4]; |
1243 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1244 | int error = 0; |
1245 | ||
eaf5bd3c SW |
1246 | switch(num_gh) { |
1247 | case 0: | |
b3b94faa | 1248 | return 0; |
eaf5bd3c | 1249 | case 1: |
b3b94faa DT |
1250 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1251 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1252 | default: |
1253 | if (num_gh <= 4) | |
b3b94faa | 1254 | break; |
eaf5bd3c SW |
1255 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1256 | if (!pph) | |
1257 | return -ENOMEM; | |
b3b94faa DT |
1258 | } |
1259 | ||
eaf5bd3c | 1260 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1261 | |
eaf5bd3c SW |
1262 | if (pph != tmp) |
1263 | kfree(pph); | |
b3b94faa DT |
1264 | |
1265 | return error; | |
1266 | } | |
1267 | ||
1268 | /** | |
1269 | * gfs2_glock_dq_m - release multiple glocks | |
1270 | * @num_gh: the number of structures | |
1271 | * @ghs: an array of struct gfs2_holder structures | |
1272 | * | |
1273 | */ | |
1274 | ||
1275 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1276 | { | |
1277 | unsigned int x; | |
1278 | ||
1279 | for (x = 0; x < num_gh; x++) | |
1280 | gfs2_glock_dq(&ghs[x]); | |
1281 | } | |
1282 | ||
1283 | /** | |
1284 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1285 | * @num_gh: the number of structures | |
1286 | * @ghs: an array of struct gfs2_holder structures | |
1287 | * | |
1288 | */ | |
1289 | ||
1290 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1291 | { | |
1292 | unsigned int x; | |
1293 | ||
1294 | for (x = 0; x < num_gh; x++) | |
1295 | gfs2_glock_dq_uninit(&ghs[x]); | |
1296 | } | |
1297 | ||
f057f6cd | 1298 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1299 | { |
c4f68a13 BM |
1300 | unsigned long delay = 0; |
1301 | unsigned long holdtime; | |
1302 | unsigned long now = jiffies; | |
b3b94faa | 1303 | |
f057f6cd | 1304 | gfs2_glock_hold(gl); |
c4f68a13 BM |
1305 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1306 | if (time_before(now, holdtime)) | |
1307 | delay = holdtime - now; | |
dff52574 SW |
1308 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
1309 | delay = gl->gl_ops->go_min_hold_time; | |
b3b94faa | 1310 | |
6802e340 | 1311 | spin_lock(&gl->gl_spin); |
97cc1025 | 1312 | handle_callback(gl, state, delay); |
6802e340 | 1313 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1314 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1315 | gfs2_glock_put(gl); | |
b3b94faa DT |
1316 | } |
1317 | ||
1318 | /** | |
f057f6cd SW |
1319 | * gfs2_glock_complete - Callback used by locking |
1320 | * @gl: Pointer to the glock | |
1321 | * @ret: The return value from the dlm | |
b3b94faa | 1322 | * |
b3b94faa DT |
1323 | */ |
1324 | ||
f057f6cd | 1325 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1326 | { |
f057f6cd | 1327 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
f057f6cd SW |
1328 | gl->gl_reply = ret; |
1329 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) { | |
1330 | struct gfs2_holder *gh; | |
1331 | spin_lock(&gl->gl_spin); | |
1332 | gh = find_first_waiter(gl); | |
1333 | if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) && | |
1334 | (gl->gl_target != LM_ST_UNLOCKED)) || | |
1335 | ((ret & ~LM_OUT_ST_MASK) != 0)) | |
1336 | set_bit(GLF_FROZEN, &gl->gl_flags); | |
1337 | spin_unlock(&gl->gl_spin); | |
d8348de0 | 1338 | if (test_bit(GLF_FROZEN, &gl->gl_flags)) |
b3b94faa | 1339 | return; |
b3b94faa | 1340 | } |
f057f6cd SW |
1341 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1342 | gfs2_glock_hold(gl); | |
1343 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1344 | gfs2_glock_put(gl); | |
b3b94faa DT |
1345 | } |
1346 | ||
b3b94faa | 1347 | |
97cc1025 | 1348 | static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask) |
b3b94faa DT |
1349 | { |
1350 | struct gfs2_glock *gl; | |
97cc1025 SW |
1351 | int may_demote; |
1352 | int nr_skipped = 0; | |
97cc1025 | 1353 | LIST_HEAD(skipped); |
b3b94faa | 1354 | |
97cc1025 SW |
1355 | if (nr == 0) |
1356 | goto out; | |
b3b94faa | 1357 | |
97cc1025 SW |
1358 | if (!(gfp_mask & __GFP_FS)) |
1359 | return -1; | |
b3b94faa | 1360 | |
97cc1025 SW |
1361 | spin_lock(&lru_lock); |
1362 | while(nr && !list_empty(&lru_list)) { | |
1363 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1364 | list_del_init(&gl->gl_lru); | |
1365 | atomic_dec(&lru_count); | |
1366 | ||
1367 | /* Test for being demotable */ | |
1368 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1369 | gfs2_glock_hold(gl); | |
97cc1025 SW |
1370 | spin_unlock(&lru_lock); |
1371 | spin_lock(&gl->gl_spin); | |
1372 | may_demote = demote_ok(gl); | |
97cc1025 SW |
1373 | if (may_demote) { |
1374 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1375 | nr--; | |
97cc1025 | 1376 | } |
7e71c55e SW |
1377 | clear_bit(GLF_LOCK, &gl->gl_flags); |
1378 | smp_mb__after_clear_bit(); | |
2163b1e6 | 1379 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
b94a170e BM |
1380 | gfs2_glock_put_nolock(gl); |
1381 | spin_unlock(&gl->gl_spin); | |
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 | 1510 | { |
b3b94faa | 1511 | unsigned int x; |
b3b94faa | 1512 | |
c1184f8a SW |
1513 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) |
1514 | examine_bucket(clear_glock, sdp, x); | |
8f05228e SW |
1515 | flush_workqueue(glock_workqueue); |
1516 | wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0); | |
1517 | gfs2_dump_lockstate(sdp); | |
b3b94faa DT |
1518 | } |
1519 | ||
813e0c46 SW |
1520 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1521 | { | |
1522 | struct gfs2_glock *gl = ip->i_gl; | |
1523 | int ret; | |
1524 | ||
1525 | ret = gfs2_truncatei_resume(ip); | |
1526 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1527 | ||
1528 | spin_lock(&gl->gl_spin); | |
1529 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1530 | run_queue(gl, 1); | |
1531 | spin_unlock(&gl->gl_spin); | |
1532 | } | |
1533 | ||
6802e340 | 1534 | static const char *state2str(unsigned state) |
04b933f2 | 1535 | { |
6802e340 SW |
1536 | switch(state) { |
1537 | case LM_ST_UNLOCKED: | |
1538 | return "UN"; | |
1539 | case LM_ST_SHARED: | |
1540 | return "SH"; | |
1541 | case LM_ST_DEFERRED: | |
1542 | return "DF"; | |
1543 | case LM_ST_EXCLUSIVE: | |
1544 | return "EX"; | |
1545 | } | |
1546 | return "??"; | |
1547 | } | |
1548 | ||
1549 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1550 | { | |
1551 | char *p = buf; | |
1552 | if (flags & LM_FLAG_TRY) | |
1553 | *p++ = 't'; | |
1554 | if (flags & LM_FLAG_TRY_1CB) | |
1555 | *p++ = 'T'; | |
1556 | if (flags & LM_FLAG_NOEXP) | |
1557 | *p++ = 'e'; | |
1558 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1559 | *p++ = 'A'; |
6802e340 SW |
1560 | if (flags & LM_FLAG_PRIORITY) |
1561 | *p++ = 'p'; | |
1562 | if (flags & GL_ASYNC) | |
1563 | *p++ = 'a'; | |
1564 | if (flags & GL_EXACT) | |
1565 | *p++ = 'E'; | |
6802e340 SW |
1566 | if (flags & GL_NOCACHE) |
1567 | *p++ = 'c'; | |
1568 | if (test_bit(HIF_HOLDER, &iflags)) | |
1569 | *p++ = 'H'; | |
1570 | if (test_bit(HIF_WAIT, &iflags)) | |
1571 | *p++ = 'W'; | |
1572 | if (test_bit(HIF_FIRST, &iflags)) | |
1573 | *p++ = 'F'; | |
1574 | *p = 0; | |
1575 | return buf; | |
04b933f2 RP |
1576 | } |
1577 | ||
b3b94faa DT |
1578 | /** |
1579 | * dump_holder - print information about a glock holder | |
6802e340 | 1580 | * @seq: the seq_file struct |
b3b94faa DT |
1581 | * @gh: the glock holder |
1582 | * | |
1583 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1584 | */ | |
1585 | ||
6802e340 | 1586 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1587 | { |
6802e340 SW |
1588 | struct task_struct *gh_owner = NULL; |
1589 | char buffer[KSYM_SYMBOL_LEN]; | |
1590 | char flags_buf[32]; | |
b3b94faa | 1591 | |
6802e340 SW |
1592 | sprint_symbol(buffer, gh->gh_ip); |
1593 | if (gh->gh_owner_pid) | |
b1e058da | 1594 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
6802e340 SW |
1595 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", |
1596 | state2str(gh->gh_state), | |
1597 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1598 | gh->gh_error, | |
1599 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1600 | gh_owner ? gh_owner->comm : "(ended)", buffer); | |
7c52b166 | 1601 | return 0; |
b3b94faa DT |
1602 | } |
1603 | ||
6802e340 SW |
1604 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1605 | { | |
1606 | char *p = buf; | |
1607 | if (test_bit(GLF_LOCK, gflags)) | |
1608 | *p++ = 'l'; | |
6802e340 SW |
1609 | if (test_bit(GLF_DEMOTE, gflags)) |
1610 | *p++ = 'D'; | |
1611 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1612 | *p++ = 'd'; | |
1613 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1614 | *p++ = 'p'; | |
1615 | if (test_bit(GLF_DIRTY, gflags)) | |
1616 | *p++ = 'y'; | |
1617 | if (test_bit(GLF_LFLUSH, gflags)) | |
1618 | *p++ = 'f'; | |
1619 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1620 | *p++ = 'i'; | |
1621 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1622 | *p++ = 'r'; | |
f057f6cd | 1623 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1624 | *p++ = 'I'; |
f057f6cd SW |
1625 | if (test_bit(GLF_FROZEN, gflags)) |
1626 | *p++ = 'F'; | |
6802e340 SW |
1627 | *p = 0; |
1628 | return buf; | |
b3b94faa DT |
1629 | } |
1630 | ||
1631 | /** | |
6802e340 SW |
1632 | * __dump_glock - print information about a glock |
1633 | * @seq: The seq_file struct | |
b3b94faa | 1634 | * @gl: the glock |
6802e340 SW |
1635 | * |
1636 | * The file format is as follows: | |
1637 | * One line per object, capital letters are used to indicate objects | |
1638 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1639 | * other objects are indented by a single space and follow the glock to | |
1640 | * which they are related. Fields are indicated by lower case letters | |
1641 | * followed by a colon and the field value, except for strings which are in | |
1642 | * [] so that its possible to see if they are composed of spaces for | |
1643 | * example. The field's are n = number (id of the object), f = flags, | |
1644 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1645 | * |
1646 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1647 | */ | |
1648 | ||
6802e340 | 1649 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1650 | { |
6802e340 SW |
1651 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1652 | unsigned long long dtime; | |
1653 | const struct gfs2_holder *gh; | |
1654 | char gflags_buf[32]; | |
1655 | int error = 0; | |
b3b94faa | 1656 | |
6802e340 SW |
1657 | dtime = jiffies - gl->gl_demote_time; |
1658 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1659 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1660 | dtime = 0; | |
4818972e | 1661 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d r:%d\n", |
6802e340 SW |
1662 | state2str(gl->gl_state), |
1663 | gl->gl_name.ln_type, | |
1664 | (unsigned long long)gl->gl_name.ln_number, | |
1665 | gflags2str(gflags_buf, &gl->gl_flags), | |
1666 | state2str(gl->gl_target), | |
1667 | state2str(gl->gl_demote_state), dtime, | |
6802e340 SW |
1668 | atomic_read(&gl->gl_ail_count), |
1669 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1670 | |
b3b94faa | 1671 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1672 | error = dump_holder(seq, gh); |
b3b94faa DT |
1673 | if (error) |
1674 | goto out; | |
1675 | } | |
6802e340 SW |
1676 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1677 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1678 | out: |
b3b94faa DT |
1679 | return error; |
1680 | } | |
1681 | ||
6802e340 SW |
1682 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1683 | { | |
1684 | int ret; | |
1685 | spin_lock(&gl->gl_spin); | |
1686 | ret = __dump_glock(seq, gl); | |
1687 | spin_unlock(&gl->gl_spin); | |
1688 | return ret; | |
1689 | } | |
1690 | ||
b3b94faa DT |
1691 | /** |
1692 | * gfs2_dump_lockstate - print out the current lockstate | |
1693 | * @sdp: the filesystem | |
1694 | * @ub: the buffer to copy the information into | |
1695 | * | |
1696 | * If @ub is NULL, dump the lockstate to the console. | |
1697 | * | |
1698 | */ | |
1699 | ||
08bc2dbc | 1700 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1701 | { |
b3b94faa | 1702 | struct gfs2_glock *gl; |
b6397893 | 1703 | struct hlist_node *h; |
b3b94faa DT |
1704 | unsigned int x; |
1705 | int error = 0; | |
1706 | ||
1707 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1708 | |
087efdd3 | 1709 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1710 | |
b6397893 | 1711 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1712 | if (gl->gl_sbd != sdp) |
1713 | continue; | |
b3b94faa | 1714 | |
7c52b166 | 1715 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1716 | if (error) |
1717 | break; | |
1718 | } | |
1719 | ||
087efdd3 | 1720 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1721 | |
1722 | if (error) | |
1723 | break; | |
1724 | } | |
1725 | ||
1726 | ||
1727 | return error; | |
1728 | } | |
1729 | ||
8fbbfd21 | 1730 | |
85d1da67 SW |
1731 | int __init gfs2_glock_init(void) |
1732 | { | |
1733 | unsigned i; | |
1734 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1735 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1736 | } |
087efdd3 SW |
1737 | #ifdef GL_HASH_LOCK_SZ |
1738 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1739 | rwlock_init(&gl_hash_locks[i]); | |
1740 | } | |
1741 | #endif | |
8fbbfd21 | 1742 | |
c4f68a13 | 1743 | glock_workqueue = create_workqueue("glock_workqueue"); |
97cc1025 | 1744 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1745 | return PTR_ERR(glock_workqueue); |
b94a170e BM |
1746 | gfs2_delete_workqueue = create_workqueue("delete_workqueue"); |
1747 | if (IS_ERR(gfs2_delete_workqueue)) { | |
1748 | destroy_workqueue(glock_workqueue); | |
1749 | return PTR_ERR(gfs2_delete_workqueue); | |
1750 | } | |
97cc1025 SW |
1751 | |
1752 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1753 | |
85d1da67 SW |
1754 | return 0; |
1755 | } | |
1756 | ||
8fbbfd21 SW |
1757 | void gfs2_glock_exit(void) |
1758 | { | |
97cc1025 | 1759 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1760 | destroy_workqueue(glock_workqueue); |
b94a170e | 1761 | destroy_workqueue(gfs2_delete_workqueue); |
8fbbfd21 SW |
1762 | } |
1763 | ||
6802e340 | 1764 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1765 | { |
7b08fc62 SW |
1766 | struct gfs2_glock *gl; |
1767 | ||
a947e033 | 1768 | restart: |
7a0079d9 | 1769 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1770 | gl = gi->gl; |
1771 | if (gl) { | |
a947e033 AD |
1772 | gi->gl = hlist_entry(gl->gl_list.next, |
1773 | struct gfs2_glock, gl_list); | |
c1e817d0 SW |
1774 | } else { |
1775 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1776 | struct gfs2_glock, gl_list); | |
7c52b166 | 1777 | } |
c1e817d0 SW |
1778 | if (gi->gl) |
1779 | gfs2_glock_hold(gi->gl); | |
7a0079d9 | 1780 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
1781 | if (gl) |
1782 | gfs2_glock_put(gl); | |
6802e340 | 1783 | while (gi->gl == NULL) { |
c1e817d0 | 1784 | gi->hash++; |
7b08fc62 SW |
1785 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
1786 | return 1; | |
1787 | read_lock(gl_lock_addr(gi->hash)); | |
1788 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
1789 | struct gfs2_glock, gl_list); | |
1790 | if (gi->gl) | |
1791 | gfs2_glock_hold(gi->gl); | |
1792 | read_unlock(gl_lock_addr(gi->hash)); | |
1793 | } | |
a947e033 AD |
1794 | |
1795 | if (gi->sdp != gi->gl->gl_sbd) | |
1796 | goto restart; | |
1797 | ||
7c52b166 RP |
1798 | return 0; |
1799 | } | |
1800 | ||
6802e340 | 1801 | static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) |
7c52b166 | 1802 | { |
7b08fc62 SW |
1803 | if (gi->gl) |
1804 | gfs2_glock_put(gi->gl); | |
a947e033 | 1805 | gi->gl = NULL; |
7c52b166 RP |
1806 | } |
1807 | ||
6802e340 | 1808 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1809 | { |
6802e340 | 1810 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1811 | loff_t n = *pos; |
1812 | ||
6802e340 | 1813 | gi->hash = 0; |
7c52b166 | 1814 | |
6802e340 | 1815 | do { |
7c52b166 RP |
1816 | if (gfs2_glock_iter_next(gi)) { |
1817 | gfs2_glock_iter_free(gi); | |
1818 | return NULL; | |
1819 | } | |
6802e340 | 1820 | } while (n--); |
7c52b166 | 1821 | |
6802e340 | 1822 | return gi->gl; |
7c52b166 RP |
1823 | } |
1824 | ||
6802e340 | 1825 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1826 | loff_t *pos) |
1827 | { | |
6802e340 | 1828 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1829 | |
1830 | (*pos)++; | |
1831 | ||
1832 | if (gfs2_glock_iter_next(gi)) { | |
1833 | gfs2_glock_iter_free(gi); | |
1834 | return NULL; | |
1835 | } | |
1836 | ||
6802e340 | 1837 | return gi->gl; |
7c52b166 RP |
1838 | } |
1839 | ||
6802e340 | 1840 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1841 | { |
6802e340 SW |
1842 | struct gfs2_glock_iter *gi = seq->private; |
1843 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
1844 | } |
1845 | ||
6802e340 | 1846 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1847 | { |
6802e340 | 1848 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1849 | } |
1850 | ||
4ef29002 | 1851 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1852 | .start = gfs2_glock_seq_start, |
1853 | .next = gfs2_glock_seq_next, | |
1854 | .stop = gfs2_glock_seq_stop, | |
1855 | .show = gfs2_glock_seq_show, | |
1856 | }; | |
1857 | ||
1858 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1859 | { | |
6802e340 SW |
1860 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1861 | sizeof(struct gfs2_glock_iter)); | |
1862 | if (ret == 0) { | |
1863 | struct seq_file *seq = file->private_data; | |
1864 | struct gfs2_glock_iter *gi = seq->private; | |
1865 | gi->sdp = inode->i_private; | |
1866 | } | |
1867 | return ret; | |
7c52b166 RP |
1868 | } |
1869 | ||
1870 | static const struct file_operations gfs2_debug_fops = { | |
1871 | .owner = THIS_MODULE, | |
1872 | .open = gfs2_debugfs_open, | |
1873 | .read = seq_read, | |
1874 | .llseek = seq_lseek, | |
6802e340 | 1875 | .release = seq_release_private, |
7c52b166 RP |
1876 | }; |
1877 | ||
1878 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1879 | { | |
5f882096 RP |
1880 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1881 | if (!sdp->debugfs_dir) | |
1882 | return -ENOMEM; | |
1883 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1884 | S_IFREG | S_IRUGO, | |
1885 | sdp->debugfs_dir, sdp, | |
1886 | &gfs2_debug_fops); | |
1887 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1888 | return -ENOMEM; |
1889 | ||
1890 | return 0; | |
1891 | } | |
1892 | ||
1893 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1894 | { | |
5f882096 RP |
1895 | if (sdp && sdp->debugfs_dir) { |
1896 | if (sdp->debugfs_dentry_glocks) { | |
1897 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1898 | sdp->debugfs_dentry_glocks = NULL; | |
1899 | } | |
1900 | debugfs_remove(sdp->debugfs_dir); | |
1901 | sdp->debugfs_dir = NULL; | |
1902 | } | |
7c52b166 RP |
1903 | } |
1904 | ||
1905 | int gfs2_register_debugfs(void) | |
1906 | { | |
1907 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1908 | return gfs2_root ? 0 : -ENOMEM; | |
1909 | } | |
1910 | ||
1911 | void gfs2_unregister_debugfs(void) | |
1912 | { | |
1913 | debugfs_remove(gfs2_root); | |
5f882096 | 1914 | gfs2_root = NULL; |
7c52b166 | 1915 | } |