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Commit | Line | Data |
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b3b94faa DT |
1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
3a8a9a10 | 3 | * Copyright (C) 2004-2006 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> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/sort.h> | |
17 | #include <linux/jhash.h> | |
d0dc80db | 18 | #include <linux/kallsyms.h> |
5c676f6d | 19 | #include <linux/gfs2_ondisk.h> |
24264434 | 20 | #include <linux/list.h> |
7d308590 | 21 | #include <linux/lm_interface.h> |
fee852e3 | 22 | #include <linux/wait.h> |
95d97b7d | 23 | #include <linux/module.h> |
61be084e | 24 | #include <linux/rwsem.h> |
b3b94faa | 25 | #include <asm/uaccess.h> |
7c52b166 RP |
26 | #include <linux/seq_file.h> |
27 | #include <linux/debugfs.h> | |
04b933f2 RP |
28 | #include <linux/module.h> |
29 | #include <linux/kallsyms.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" | |
36 | #include "lm.h" | |
37 | #include "lops.h" | |
38 | #include "meta_io.h" | |
39 | #include "quota.h" | |
40 | #include "super.h" | |
5c676f6d | 41 | #include "util.h" |
b3b94faa | 42 | |
37b2fa6a | 43 | struct gfs2_gl_hash_bucket { |
b6397893 | 44 | struct hlist_head hb_list; |
37b2fa6a SW |
45 | }; |
46 | ||
7c52b166 RP |
47 | struct glock_iter { |
48 | int hash; /* hash bucket index */ | |
49 | struct gfs2_sbd *sdp; /* incore superblock */ | |
50 | struct gfs2_glock *gl; /* current glock struct */ | |
51 | struct hlist_head *hb_list; /* current hash bucket ptr */ | |
52 | struct seq_file *seq; /* sequence file for debugfs */ | |
53 | char string[512]; /* scratch space */ | |
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); |
04b933f2 | 59 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl); |
3b8249f6 | 60 | static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh); |
b5d32bea | 61 | static void gfs2_glock_drop_th(struct gfs2_glock *gl); |
61be084e | 62 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
7c52b166 | 63 | static struct dentry *gfs2_root; |
08bc2dbc | 64 | |
b6397893 | 65 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
66 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
67 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
68 | ||
85d1da67 | 69 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 70 | static struct dentry *gfs2_root; |
087efdd3 SW |
71 | |
72 | /* | |
73 | * Despite what you might think, the numbers below are not arbitrary :-) | |
74 | * They are taken from the ipv4 routing hash code, which is well tested | |
75 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
76 | * but for now this should be fine. | |
77 | * | |
78 | * The reason for putting the locks in a separate array from the list heads | |
79 | * is that we can have fewer locks than list heads and save memory. We use | |
80 | * the same hash function for both, but with a different hash mask. | |
81 | */ | |
82 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
83 | defined(CONFIG_PROVE_LOCKING) | |
84 | ||
85 | #ifdef CONFIG_LOCKDEP | |
86 | # define GL_HASH_LOCK_SZ 256 | |
87 | #else | |
88 | # if NR_CPUS >= 32 | |
89 | # define GL_HASH_LOCK_SZ 4096 | |
90 | # elif NR_CPUS >= 16 | |
91 | # define GL_HASH_LOCK_SZ 2048 | |
92 | # elif NR_CPUS >= 8 | |
93 | # define GL_HASH_LOCK_SZ 1024 | |
94 | # elif NR_CPUS >= 4 | |
95 | # define GL_HASH_LOCK_SZ 512 | |
96 | # else | |
97 | # define GL_HASH_LOCK_SZ 256 | |
98 | # endif | |
99 | #endif | |
100 | ||
101 | /* We never want more locks than chains */ | |
102 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
103 | # undef GL_HASH_LOCK_SZ | |
104 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
105 | #endif | |
106 | ||
107 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
108 | ||
109 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
110 | { | |
94610610 | 111 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
112 | } |
113 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 114 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
115 | { |
116 | return NULL; | |
117 | } | |
118 | #endif | |
85d1da67 | 119 | |
b3b94faa DT |
120 | /** |
121 | * relaxed_state_ok - is a requested lock compatible with the current lock mode? | |
122 | * @actual: the current state of the lock | |
123 | * @requested: the lock state that was requested by the caller | |
124 | * @flags: the modifier flags passed in by the caller | |
125 | * | |
126 | * Returns: 1 if the locks are compatible, 0 otherwise | |
127 | */ | |
128 | ||
129 | static inline int relaxed_state_ok(unsigned int actual, unsigned requested, | |
130 | int flags) | |
131 | { | |
132 | if (actual == requested) | |
133 | return 1; | |
134 | ||
135 | if (flags & GL_EXACT) | |
136 | return 0; | |
137 | ||
138 | if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) | |
139 | return 1; | |
140 | ||
141 | if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) | |
142 | return 1; | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | /** | |
148 | * gl_hash() - Turn glock number into hash bucket number | |
149 | * @lock: The glock number | |
150 | * | |
151 | * Returns: The number of the corresponding hash bucket | |
152 | */ | |
153 | ||
b8547856 SW |
154 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
155 | const struct lm_lockname *name) | |
b3b94faa DT |
156 | { |
157 | unsigned int h; | |
158 | ||
cd915493 | 159 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 160 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 161 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
162 | h &= GFS2_GL_HASH_MASK; |
163 | ||
164 | return h; | |
165 | } | |
166 | ||
167 | /** | |
168 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
169 | * @gl: The glock to release | |
170 | * | |
171 | * Also calls lock module to release its internal structure for this glock. | |
172 | * | |
173 | */ | |
174 | ||
175 | static void glock_free(struct gfs2_glock *gl) | |
176 | { | |
177 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
178 | struct inode *aspace = gl->gl_aspace; | |
179 | ||
180 | gfs2_lm_put_lock(sdp, gl->gl_lock); | |
181 | ||
182 | if (aspace) | |
183 | gfs2_aspace_put(aspace); | |
184 | ||
185 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
186 | } |
187 | ||
188 | /** | |
189 | * gfs2_glock_hold() - increment reference count on glock | |
190 | * @gl: The glock to hold | |
191 | * | |
192 | */ | |
193 | ||
194 | void gfs2_glock_hold(struct gfs2_glock *gl) | |
195 | { | |
16feb9fe | 196 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
197 | } |
198 | ||
199 | /** | |
200 | * gfs2_glock_put() - Decrement reference count on glock | |
201 | * @gl: The glock to put | |
202 | * | |
203 | */ | |
204 | ||
205 | int gfs2_glock_put(struct gfs2_glock *gl) | |
206 | { | |
b3b94faa | 207 | int rv = 0; |
16feb9fe | 208 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b3b94faa | 209 | |
087efdd3 | 210 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 211 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 212 | hlist_del(&gl->gl_list); |
087efdd3 | 213 | write_unlock(gl_lock_addr(gl->gl_hash)); |
190562bd | 214 | BUG_ON(spin_is_locked(&gl->gl_spin)); |
16feb9fe SW |
215 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); |
216 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
217 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
218 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
16feb9fe | 219 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); |
b3b94faa DT |
220 | glock_free(gl); |
221 | rv = 1; | |
222 | goto out; | |
223 | } | |
087efdd3 | 224 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 225 | out: |
b3b94faa DT |
226 | return rv; |
227 | } | |
228 | ||
b3b94faa DT |
229 | /** |
230 | * search_bucket() - Find struct gfs2_glock by lock number | |
231 | * @bucket: the bucket to search | |
232 | * @name: The lock name | |
233 | * | |
234 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
235 | */ | |
236 | ||
37b2fa6a | 237 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 238 | const struct gfs2_sbd *sdp, |
d6a53727 | 239 | const struct lm_lockname *name) |
b3b94faa DT |
240 | { |
241 | struct gfs2_glock *gl; | |
b6397893 | 242 | struct hlist_node *h; |
b3b94faa | 243 | |
b6397893 | 244 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
245 | if (!lm_name_equal(&gl->gl_name, name)) |
246 | continue; | |
899be4d3 SW |
247 | if (gl->gl_sbd != sdp) |
248 | continue; | |
b3b94faa | 249 | |
16feb9fe | 250 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
251 | |
252 | return gl; | |
253 | } | |
254 | ||
255 | return NULL; | |
256 | } | |
257 | ||
258 | /** | |
259 | * gfs2_glock_find() - Find glock by lock number | |
260 | * @sdp: The GFS2 superblock | |
261 | * @name: The lock name | |
262 | * | |
263 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
264 | */ | |
265 | ||
85d1da67 | 266 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 267 | const struct lm_lockname *name) |
b3b94faa | 268 | { |
37b2fa6a | 269 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
270 | struct gfs2_glock *gl; |
271 | ||
087efdd3 | 272 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 273 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 274 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
275 | |
276 | return gl; | |
277 | } | |
278 | ||
279 | /** | |
280 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
281 | * @sdp: The GFS2 superblock | |
282 | * @number: the lock number | |
283 | * @glops: The glock_operations to use | |
284 | * @create: If 0, don't create the glock if it doesn't exist | |
285 | * @glp: the glock is returned here | |
286 | * | |
287 | * This does not lock a glock, just finds/creates structures for one. | |
288 | * | |
289 | * Returns: errno | |
290 | */ | |
291 | ||
cd915493 | 292 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 293 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
294 | struct gfs2_glock **glp) |
295 | { | |
37b2fa6a | 296 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 297 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 298 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
299 | int error; |
300 | ||
087efdd3 | 301 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 302 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 303 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
304 | |
305 | if (gl || !create) { | |
306 | *glp = gl; | |
307 | return 0; | |
308 | } | |
309 | ||
310 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
311 | if (!gl) | |
312 | return -ENOMEM; | |
313 | ||
ec45d9f5 | 314 | gl->gl_flags = 0; |
b3b94faa | 315 | gl->gl_name = name; |
16feb9fe | 316 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 317 | gl->gl_state = LM_ST_UNLOCKED; |
37b2fa6a | 318 | gl->gl_hash = hash; |
04b933f2 | 319 | gl->gl_owner_pid = 0; |
320dd101 | 320 | gl->gl_ip = 0; |
b3b94faa | 321 | gl->gl_ops = glops; |
ec45d9f5 SW |
322 | gl->gl_req_gh = NULL; |
323 | gl->gl_req_bh = NULL; | |
324 | gl->gl_vn = 0; | |
325 | gl->gl_stamp = jiffies; | |
326 | gl->gl_object = NULL; | |
b3b94faa | 327 | gl->gl_sbd = sdp; |
ec45d9f5 | 328 | gl->gl_aspace = NULL; |
b3b94faa | 329 | lops_init_le(&gl->gl_le, &gfs2_glock_lops); |
b3b94faa DT |
330 | |
331 | /* If this glock protects actual on-disk data or metadata blocks, | |
332 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 333 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
334 | gl->gl_aspace = gfs2_aspace_get(sdp); |
335 | if (!gl->gl_aspace) { | |
336 | error = -ENOMEM; | |
337 | goto fail; | |
338 | } | |
339 | } | |
340 | ||
341 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
342 | if (error) | |
343 | goto fail_aspace; | |
344 | ||
087efdd3 | 345 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 346 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 347 | if (tmp) { |
087efdd3 | 348 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
349 | glock_free(gl); |
350 | gl = tmp; | |
351 | } else { | |
b6397893 | 352 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 353 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
354 | } |
355 | ||
356 | *glp = gl; | |
357 | ||
358 | return 0; | |
359 | ||
ec45d9f5 | 360 | fail_aspace: |
b3b94faa DT |
361 | if (gl->gl_aspace) |
362 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 363 | fail: |
907b9bce | 364 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
365 | return error; |
366 | } | |
367 | ||
368 | /** | |
369 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
370 | * @gl: the glock | |
371 | * @state: the state we're requesting | |
372 | * @flags: the modifier flags | |
373 | * @gh: the holder structure | |
374 | * | |
375 | */ | |
376 | ||
190562bd | 377 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
378 | struct gfs2_holder *gh) |
379 | { | |
380 | INIT_LIST_HEAD(&gh->gh_list); | |
381 | gh->gh_gl = gl; | |
d0dc80db | 382 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
04b933f2 | 383 | gh->gh_owner_pid = current->pid; |
b3b94faa DT |
384 | gh->gh_state = state; |
385 | gh->gh_flags = flags; | |
386 | gh->gh_error = 0; | |
387 | gh->gh_iflags = 0; | |
b3b94faa DT |
388 | gfs2_glock_hold(gl); |
389 | } | |
390 | ||
391 | /** | |
392 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
393 | * @state: the state we're requesting | |
394 | * @flags: the modifier flags | |
395 | * @gh: the holder structure | |
396 | * | |
397 | * Don't mess with the glock. | |
398 | * | |
399 | */ | |
400 | ||
190562bd | 401 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
402 | { |
403 | gh->gh_state = state; | |
579b78a4 | 404 | gh->gh_flags = flags; |
3b8249f6 | 405 | gh->gh_iflags = 0; |
d0dc80db | 406 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
407 | } |
408 | ||
409 | /** | |
410 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
411 | * @gh: the holder structure | |
412 | * | |
413 | */ | |
414 | ||
415 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
416 | { | |
417 | gfs2_glock_put(gh->gh_gl); | |
418 | gh->gh_gl = NULL; | |
d0dc80db | 419 | gh->gh_ip = 0; |
b3b94faa DT |
420 | } |
421 | ||
3b8249f6 | 422 | static void gfs2_holder_wake(struct gfs2_holder *gh) |
fee852e3 | 423 | { |
fee852e3 SW |
424 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
425 | smp_mb(); | |
426 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
427 | } | |
428 | ||
429 | static int holder_wait(void *word) | |
430 | { | |
431 | schedule(); | |
432 | return 0; | |
433 | } | |
434 | ||
435 | static void wait_on_holder(struct gfs2_holder *gh) | |
436 | { | |
437 | might_sleep(); | |
438 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE); | |
439 | } | |
440 | ||
b3b94faa DT |
441 | /** |
442 | * rq_mutex - process a mutex request in the queue | |
443 | * @gh: the glock holder | |
444 | * | |
445 | * Returns: 1 if the queue is blocked | |
446 | */ | |
447 | ||
448 | static int rq_mutex(struct gfs2_holder *gh) | |
449 | { | |
450 | struct gfs2_glock *gl = gh->gh_gl; | |
451 | ||
452 | list_del_init(&gh->gh_list); | |
453 | /* gh->gh_error never examined. */ | |
454 | set_bit(GLF_LOCK, &gl->gl_flags); | |
d043e190 | 455 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
fee852e3 SW |
456 | smp_mb(); |
457 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
b3b94faa DT |
458 | |
459 | return 1; | |
460 | } | |
461 | ||
462 | /** | |
463 | * rq_promote - process a promote request in the queue | |
464 | * @gh: the glock holder | |
465 | * | |
466 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
467 | * | |
468 | * Returns: 1 if the queue is blocked | |
469 | */ | |
470 | ||
471 | static int rq_promote(struct gfs2_holder *gh) | |
472 | { | |
473 | struct gfs2_glock *gl = gh->gh_gl; | |
474 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa DT |
475 | |
476 | if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
477 | if (list_empty(&gl->gl_holders)) { | |
478 | gl->gl_req_gh = gh; | |
479 | set_bit(GLF_LOCK, &gl->gl_flags); | |
480 | spin_unlock(&gl->gl_spin); | |
481 | ||
482 | if (atomic_read(&sdp->sd_reclaim_count) > | |
483 | gfs2_tune_get(sdp, gt_reclaim_limit) && | |
484 | !(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
485 | gfs2_reclaim_glock(sdp); | |
486 | gfs2_reclaim_glock(sdp); | |
487 | } | |
488 | ||
3b8249f6 | 489 | gfs2_glock_xmote_th(gh->gh_gl, gh); |
b3b94faa DT |
490 | spin_lock(&gl->gl_spin); |
491 | } | |
492 | return 1; | |
493 | } | |
494 | ||
495 | if (list_empty(&gl->gl_holders)) { | |
496 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
497 | set_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
498 | } else { |
499 | struct gfs2_holder *next_gh; | |
1c0f4872 | 500 | if (gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa DT |
501 | return 1; |
502 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
503 | gh_list); | |
1c0f4872 | 504 | if (next_gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa | 505 | return 1; |
b3b94faa DT |
506 | } |
507 | ||
508 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
509 | gh->gh_error = 0; | |
510 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
511 | ||
3b8249f6 | 512 | gfs2_holder_wake(gh); |
b3b94faa DT |
513 | |
514 | return 0; | |
515 | } | |
516 | ||
517 | /** | |
518 | * rq_demote - process a demote request in the queue | |
519 | * @gh: the glock holder | |
520 | * | |
521 | * Returns: 1 if the queue is blocked | |
522 | */ | |
523 | ||
3b8249f6 | 524 | static int rq_demote(struct gfs2_glock *gl) |
b3b94faa | 525 | { |
b3b94faa DT |
526 | if (!list_empty(&gl->gl_holders)) |
527 | return 1; | |
528 | ||
3b8249f6 SW |
529 | if (gl->gl_state == gl->gl_demote_state || |
530 | gl->gl_state == LM_ST_UNLOCKED) { | |
531 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
532 | return 0; | |
b3b94faa | 533 | } |
3b8249f6 SW |
534 | set_bit(GLF_LOCK, &gl->gl_flags); |
535 | spin_unlock(&gl->gl_spin); | |
536 | if (gl->gl_demote_state == LM_ST_UNLOCKED || | |
537 | gl->gl_state != LM_ST_EXCLUSIVE) | |
538 | gfs2_glock_drop_th(gl); | |
539 | else | |
540 | gfs2_glock_xmote_th(gl, NULL); | |
541 | spin_lock(&gl->gl_spin); | |
b3b94faa DT |
542 | |
543 | return 0; | |
544 | } | |
545 | ||
b3b94faa DT |
546 | /** |
547 | * run_queue - process holder structures on a glock | |
548 | * @gl: the glock | |
549 | * | |
550 | */ | |
b3b94faa DT |
551 | static void run_queue(struct gfs2_glock *gl) |
552 | { | |
553 | struct gfs2_holder *gh; | |
554 | int blocked = 1; | |
555 | ||
556 | for (;;) { | |
557 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
558 | break; | |
559 | ||
560 | if (!list_empty(&gl->gl_waiters1)) { | |
561 | gh = list_entry(gl->gl_waiters1.next, | |
562 | struct gfs2_holder, gh_list); | |
563 | ||
564 | if (test_bit(HIF_MUTEX, &gh->gh_iflags)) | |
565 | blocked = rq_mutex(gh); | |
566 | else | |
567 | gfs2_assert_warn(gl->gl_sbd, 0); | |
568 | ||
3b8249f6 SW |
569 | } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
570 | blocked = rq_demote(gl); | |
b3b94faa DT |
571 | } else if (!list_empty(&gl->gl_waiters3)) { |
572 | gh = list_entry(gl->gl_waiters3.next, | |
573 | struct gfs2_holder, gh_list); | |
574 | ||
575 | if (test_bit(HIF_PROMOTE, &gh->gh_iflags)) | |
576 | blocked = rq_promote(gh); | |
577 | else | |
578 | gfs2_assert_warn(gl->gl_sbd, 0); | |
579 | ||
580 | } else | |
581 | break; | |
582 | ||
583 | if (blocked) | |
584 | break; | |
585 | } | |
586 | } | |
587 | ||
588 | /** | |
589 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
590 | * @gl: the glock | |
591 | * | |
592 | * Gives caller exclusive access to manipulate a glock structure. | |
593 | */ | |
594 | ||
feaa7bba | 595 | static void gfs2_glmutex_lock(struct gfs2_glock *gl) |
b3b94faa DT |
596 | { |
597 | struct gfs2_holder gh; | |
598 | ||
599 | gfs2_holder_init(gl, 0, 0, &gh); | |
600 | set_bit(HIF_MUTEX, &gh.gh_iflags); | |
fee852e3 SW |
601 | if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags)) |
602 | BUG(); | |
b3b94faa DT |
603 | |
604 | spin_lock(&gl->gl_spin); | |
85d1da67 | 605 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 606 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); |
85d1da67 | 607 | } else { |
04b933f2 | 608 | gl->gl_owner_pid = current->pid; |
320dd101 | 609 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
fee852e3 SW |
610 | clear_bit(HIF_WAIT, &gh.gh_iflags); |
611 | smp_mb(); | |
612 | wake_up_bit(&gh.gh_iflags, HIF_WAIT); | |
320dd101 | 613 | } |
b3b94faa DT |
614 | spin_unlock(&gl->gl_spin); |
615 | ||
fee852e3 | 616 | wait_on_holder(&gh); |
b3b94faa DT |
617 | gfs2_holder_uninit(&gh); |
618 | } | |
619 | ||
620 | /** | |
621 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
622 | * @gl: the glock | |
623 | * | |
624 | * Returns: 1 if the glock is acquired | |
625 | */ | |
626 | ||
08bc2dbc | 627 | static int gfs2_glmutex_trylock(struct gfs2_glock *gl) |
b3b94faa DT |
628 | { |
629 | int acquired = 1; | |
630 | ||
631 | spin_lock(&gl->gl_spin); | |
85d1da67 | 632 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 633 | acquired = 0; |
85d1da67 | 634 | } else { |
04b933f2 | 635 | gl->gl_owner_pid = current->pid; |
320dd101 SW |
636 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
637 | } | |
b3b94faa DT |
638 | spin_unlock(&gl->gl_spin); |
639 | ||
640 | return acquired; | |
641 | } | |
642 | ||
643 | /** | |
644 | * gfs2_glmutex_unlock - release a local lock on a glock | |
645 | * @gl: the glock | |
646 | * | |
647 | */ | |
648 | ||
feaa7bba | 649 | static void gfs2_glmutex_unlock(struct gfs2_glock *gl) |
b3b94faa DT |
650 | { |
651 | spin_lock(&gl->gl_spin); | |
652 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
04b933f2 | 653 | gl->gl_owner_pid = 0; |
320dd101 | 654 | gl->gl_ip = 0; |
b3b94faa | 655 | run_queue(gl); |
190562bd | 656 | BUG_ON(!spin_is_locked(&gl->gl_spin)); |
b3b94faa DT |
657 | spin_unlock(&gl->gl_spin); |
658 | } | |
659 | ||
660 | /** | |
3b8249f6 | 661 | * handle_callback - process a demote request |
b3b94faa DT |
662 | * @gl: the glock |
663 | * @state: the state the caller wants us to change to | |
664 | * | |
3b8249f6 SW |
665 | * There are only two requests that we are going to see in actual |
666 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
667 | */ |
668 | ||
669 | static void handle_callback(struct gfs2_glock *gl, unsigned int state) | |
670 | { | |
b3b94faa | 671 | spin_lock(&gl->gl_spin); |
3b8249f6 SW |
672 | if (test_and_set_bit(GLF_DEMOTE, &gl->gl_flags) == 0) { |
673 | gl->gl_demote_state = state; | |
674 | gl->gl_demote_time = jiffies; | |
675 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED) { | |
676 | gl->gl_demote_state = state; | |
b3b94faa | 677 | } |
b3b94faa | 678 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
679 | } |
680 | ||
681 | /** | |
682 | * state_change - record that the glock is now in a different state | |
683 | * @gl: the glock | |
684 | * @new_state the new state | |
685 | * | |
686 | */ | |
687 | ||
688 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
689 | { | |
b3b94faa DT |
690 | int held1, held2; |
691 | ||
692 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
693 | held2 = (new_state != LM_ST_UNLOCKED); | |
694 | ||
695 | if (held1 != held2) { | |
6a6b3d01 | 696 | if (held2) |
b3b94faa | 697 | gfs2_glock_hold(gl); |
6a6b3d01 | 698 | else |
b3b94faa | 699 | gfs2_glock_put(gl); |
b3b94faa DT |
700 | } |
701 | ||
702 | gl->gl_state = new_state; | |
703 | } | |
704 | ||
705 | /** | |
706 | * xmote_bh - Called after the lock module is done acquiring a lock | |
707 | * @gl: The glock in question | |
708 | * @ret: the int returned from the lock module | |
709 | * | |
710 | */ | |
711 | ||
712 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
713 | { | |
714 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 715 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
716 | struct gfs2_holder *gh = gl->gl_req_gh; |
717 | int prev_state = gl->gl_state; | |
718 | int op_done = 1; | |
719 | ||
720 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
12132933 | 721 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
722 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); |
723 | ||
724 | state_change(gl, ret & LM_OUT_ST_MASK); | |
725 | ||
726 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
727 | if (glops->go_inval) | |
1a14d3a6 | 728 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
729 | } else if (gl->gl_state == LM_ST_DEFERRED) { |
730 | /* We might not want to do this here. | |
731 | Look at moving to the inode glops. */ | |
732 | if (glops->go_inval) | |
1a14d3a6 | 733 | glops->go_inval(gl, 0); |
b3b94faa DT |
734 | } |
735 | ||
736 | /* Deal with each possible exit condition */ | |
737 | ||
3b8249f6 | 738 | if (!gh) { |
b3b94faa | 739 | gl->gl_stamp = jiffies; |
3b8249f6 SW |
740 | if (ret & LM_OUT_CANCELED) |
741 | op_done = 0; | |
742 | else | |
743 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
744 | } else { | |
b3b94faa DT |
745 | spin_lock(&gl->gl_spin); |
746 | list_del_init(&gh->gh_list); | |
747 | gh->gh_error = -EIO; | |
3b8249f6 SW |
748 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
749 | goto out; | |
750 | gh->gh_error = GLR_CANCELED; | |
751 | if (ret & LM_OUT_CANCELED) | |
752 | goto out; | |
753 | if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
754 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
b3b94faa | 755 | gh->gh_error = 0; |
3b8249f6 SW |
756 | set_bit(HIF_HOLDER, &gh->gh_iflags); |
757 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
758 | op_done = 0; | |
759 | goto out; | |
b3b94faa | 760 | } |
b3b94faa | 761 | gh->gh_error = GLR_TRYFAILED; |
3b8249f6 SW |
762 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
763 | goto out; | |
764 | gh->gh_error = -EINVAL; | |
b3b94faa DT |
765 | if (gfs2_assert_withdraw(sdp, 0) == -1) |
766 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
3b8249f6 SW |
767 | out: |
768 | spin_unlock(&gl->gl_spin); | |
b3b94faa DT |
769 | } |
770 | ||
771 | if (glops->go_xmote_bh) | |
772 | glops->go_xmote_bh(gl); | |
773 | ||
774 | if (op_done) { | |
775 | spin_lock(&gl->gl_spin); | |
776 | gl->gl_req_gh = NULL; | |
777 | gl->gl_req_bh = NULL; | |
778 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
779 | run_queue(gl); | |
780 | spin_unlock(&gl->gl_spin); | |
781 | } | |
782 | ||
783 | gfs2_glock_put(gl); | |
784 | ||
fee852e3 | 785 | if (gh) |
3b8249f6 | 786 | gfs2_holder_wake(gh); |
b3b94faa DT |
787 | } |
788 | ||
789 | /** | |
790 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
791 | * @gl: The glock in question | |
792 | * @state: the requested state | |
793 | * @flags: modifier flags to the lock call | |
794 | * | |
795 | */ | |
796 | ||
3b8249f6 | 797 | void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh) |
b3b94faa DT |
798 | { |
799 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
3b8249f6 SW |
800 | int flags = gh ? gh->gh_flags : 0; |
801 | unsigned state = gh ? gh->gh_state : gl->gl_demote_state; | |
8fb4b536 | 802 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
803 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | |
804 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
805 | LM_FLAG_PRIORITY); | |
806 | unsigned int lck_ret; | |
807 | ||
b5d32bea SW |
808 | if (glops->go_xmote_th) |
809 | glops->go_xmote_th(gl); | |
810 | ||
b3b94faa | 811 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 812 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
813 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); |
814 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
815 | ||
b3b94faa DT |
816 | gfs2_glock_hold(gl); |
817 | gl->gl_req_bh = xmote_bh; | |
818 | ||
ec45d9f5 | 819 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); |
b3b94faa DT |
820 | |
821 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
822 | return; | |
823 | ||
824 | if (lck_ret & LM_OUT_ASYNC) | |
825 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
826 | else | |
827 | xmote_bh(gl, lck_ret); | |
828 | } | |
829 | ||
830 | /** | |
831 | * drop_bh - Called after a lock module unlock completes | |
832 | * @gl: the glock | |
833 | * @ret: the return status | |
834 | * | |
835 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
836 | * Doesn't drop the reference on the glock the top half took out | |
837 | * | |
838 | */ | |
839 | ||
840 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
841 | { | |
842 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 843 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
844 | struct gfs2_holder *gh = gl->gl_req_gh; |
845 | ||
b3b94faa | 846 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 847 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
848 | gfs2_assert_warn(sdp, !ret); |
849 | ||
850 | state_change(gl, LM_ST_UNLOCKED); | |
3b8249f6 | 851 | clear_bit(GLF_DEMOTE, &gl->gl_flags); |
b3b94faa DT |
852 | |
853 | if (glops->go_inval) | |
1a14d3a6 | 854 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
855 | |
856 | if (gh) { | |
857 | spin_lock(&gl->gl_spin); | |
858 | list_del_init(&gh->gh_list); | |
859 | gh->gh_error = 0; | |
860 | spin_unlock(&gl->gl_spin); | |
861 | } | |
862 | ||
b3b94faa DT |
863 | spin_lock(&gl->gl_spin); |
864 | gl->gl_req_gh = NULL; | |
865 | gl->gl_req_bh = NULL; | |
866 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
867 | run_queue(gl); | |
868 | spin_unlock(&gl->gl_spin); | |
869 | ||
870 | gfs2_glock_put(gl); | |
871 | ||
fee852e3 | 872 | if (gh) |
3b8249f6 | 873 | gfs2_holder_wake(gh); |
b3b94faa DT |
874 | } |
875 | ||
876 | /** | |
877 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
878 | * @gl: the glock | |
879 | * | |
880 | */ | |
881 | ||
b5d32bea | 882 | static void gfs2_glock_drop_th(struct gfs2_glock *gl) |
b3b94faa DT |
883 | { |
884 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 885 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
886 | unsigned int ret; |
887 | ||
b5d32bea SW |
888 | if (glops->go_drop_th) |
889 | glops->go_drop_th(gl); | |
890 | ||
b3b94faa | 891 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 892 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
893 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); |
894 | ||
b3b94faa DT |
895 | gfs2_glock_hold(gl); |
896 | gl->gl_req_bh = drop_bh; | |
897 | ||
b3b94faa DT |
898 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
899 | ||
900 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
901 | return; | |
902 | ||
903 | if (!ret) | |
904 | drop_bh(gl, ret); | |
905 | else | |
906 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
907 | } | |
908 | ||
909 | /** | |
910 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
911 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
912 | * | |
913 | * Don't cancel GL_NOCANCEL requests. | |
914 | */ | |
915 | ||
916 | static void do_cancels(struct gfs2_holder *gh) | |
917 | { | |
918 | struct gfs2_glock *gl = gh->gh_gl; | |
919 | ||
920 | spin_lock(&gl->gl_spin); | |
921 | ||
922 | while (gl->gl_req_gh != gh && | |
923 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
924 | !list_empty(&gh->gh_list)) { | |
50299965 SW |
925 | if (gl->gl_req_bh && !(gl->gl_req_gh && |
926 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
b3b94faa DT |
927 | spin_unlock(&gl->gl_spin); |
928 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
929 | msleep(100); | |
930 | spin_lock(&gl->gl_spin); | |
931 | } else { | |
932 | spin_unlock(&gl->gl_spin); | |
933 | msleep(100); | |
934 | spin_lock(&gl->gl_spin); | |
935 | } | |
936 | } | |
937 | ||
938 | spin_unlock(&gl->gl_spin); | |
939 | } | |
940 | ||
941 | /** | |
942 | * glock_wait_internal - wait on a glock acquisition | |
943 | * @gh: the glock holder | |
944 | * | |
945 | * Returns: 0 on success | |
946 | */ | |
947 | ||
948 | static int glock_wait_internal(struct gfs2_holder *gh) | |
949 | { | |
950 | struct gfs2_glock *gl = gh->gh_gl; | |
951 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 952 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
953 | |
954 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
955 | return -EIO; | |
956 | ||
957 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
958 | spin_lock(&gl->gl_spin); | |
959 | if (gl->gl_req_gh != gh && | |
960 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
961 | !list_empty(&gh->gh_list)) { | |
962 | list_del_init(&gh->gh_list); | |
963 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
964 | run_queue(gl); |
965 | spin_unlock(&gl->gl_spin); | |
966 | return gh->gh_error; | |
967 | } | |
968 | spin_unlock(&gl->gl_spin); | |
969 | } | |
970 | ||
971 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
972 | do_cancels(gh); | |
973 | ||
fee852e3 | 974 | wait_on_holder(gh); |
b3b94faa DT |
975 | if (gh->gh_error) |
976 | return gh->gh_error; | |
977 | ||
978 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
85d1da67 | 979 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, |
b3b94faa DT |
980 | gh->gh_flags)); |
981 | ||
982 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
983 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
984 | ||
985 | if (glops->go_lock) { | |
986 | gh->gh_error = glops->go_lock(gh); | |
987 | if (gh->gh_error) { | |
988 | spin_lock(&gl->gl_spin); | |
989 | list_del_init(&gh->gh_list); | |
b3b94faa DT |
990 | spin_unlock(&gl->gl_spin); |
991 | } | |
992 | } | |
993 | ||
994 | spin_lock(&gl->gl_spin); | |
995 | gl->gl_req_gh = NULL; | |
996 | gl->gl_req_bh = NULL; | |
997 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
998 | run_queue(gl); |
999 | spin_unlock(&gl->gl_spin); | |
1000 | } | |
1001 | ||
1002 | return gh->gh_error; | |
1003 | } | |
1004 | ||
1005 | static inline struct gfs2_holder * | |
04b933f2 | 1006 | find_holder_by_owner(struct list_head *head, pid_t pid) |
b3b94faa DT |
1007 | { |
1008 | struct gfs2_holder *gh; | |
1009 | ||
1010 | list_for_each_entry(gh, head, gh_list) { | |
04b933f2 | 1011 | if (gh->gh_owner_pid == pid) |
b3b94faa DT |
1012 | return gh; |
1013 | } | |
1014 | ||
1015 | return NULL; | |
1016 | } | |
1017 | ||
7c52b166 RP |
1018 | static void print_dbg(struct glock_iter *gi, const char *fmt, ...) |
1019 | { | |
1020 | va_list args; | |
1021 | ||
1022 | va_start(args, fmt); | |
1023 | if (gi) { | |
1024 | vsprintf(gi->string, fmt, args); | |
1025 | seq_printf(gi->seq, gi->string); | |
1026 | } | |
1027 | else | |
1028 | vprintk(fmt, args); | |
1029 | va_end(args); | |
1030 | } | |
1031 | ||
b3b94faa DT |
1032 | /** |
1033 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1034 | * @gh: the holder structure to add | |
1035 | * | |
1036 | */ | |
1037 | ||
1038 | static void add_to_queue(struct gfs2_holder *gh) | |
1039 | { | |
1040 | struct gfs2_glock *gl = gh->gh_gl; | |
1041 | struct gfs2_holder *existing; | |
1042 | ||
04b933f2 | 1043 | BUG_ON(!gh->gh_owner_pid); |
fee852e3 SW |
1044 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
1045 | BUG(); | |
190562bd | 1046 | |
04b933f2 | 1047 | existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner_pid); |
b3b94faa | 1048 | if (existing) { |
5965b1f4 | 1049 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
04b933f2 | 1050 | printk(KERN_INFO "pid : %d\n", existing->gh_owner_pid); |
907b9bce | 1051 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1052 | existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state); |
5965b1f4 | 1053 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); |
04b933f2 | 1054 | printk(KERN_INFO "pid : %d\n", gh->gh_owner_pid); |
907b9bce | 1055 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1056 | gl->gl_name.ln_type, gl->gl_state); |
5965b1f4 | 1057 | BUG(); |
b3b94faa DT |
1058 | } |
1059 | ||
04b933f2 | 1060 | existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner_pid); |
b3b94faa | 1061 | if (existing) { |
5965b1f4 SW |
1062 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
1063 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1064 | BUG(); | |
b3b94faa DT |
1065 | } |
1066 | ||
b3b94faa DT |
1067 | if (gh->gh_flags & LM_FLAG_PRIORITY) |
1068 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1069 | else | |
907b9bce | 1070 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); |
b3b94faa DT |
1071 | } |
1072 | ||
1073 | /** | |
1074 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1075 | * @gh: the holder structure | |
1076 | * | |
1077 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1078 | * | |
1079 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1080 | */ | |
1081 | ||
1082 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1083 | { | |
1084 | struct gfs2_glock *gl = gh->gh_gl; | |
1085 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1086 | int error = 0; | |
1087 | ||
320dd101 | 1088 | restart: |
b3b94faa DT |
1089 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
1090 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1091 | return -EIO; | |
1092 | } | |
1093 | ||
1094 | set_bit(HIF_PROMOTE, &gh->gh_iflags); | |
1095 | ||
1096 | spin_lock(&gl->gl_spin); | |
1097 | add_to_queue(gh); | |
1098 | run_queue(gl); | |
1099 | spin_unlock(&gl->gl_spin); | |
1100 | ||
1101 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1102 | error = glock_wait_internal(gh); | |
1103 | if (error == GLR_CANCELED) { | |
190562bd | 1104 | msleep(100); |
b3b94faa DT |
1105 | goto restart; |
1106 | } | |
1107 | } | |
1108 | ||
b3b94faa DT |
1109 | return error; |
1110 | } | |
1111 | ||
1112 | /** | |
1113 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1114 | * @gh: the holder | |
1115 | * | |
1116 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1117 | */ | |
1118 | ||
1119 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1120 | { | |
1121 | struct gfs2_glock *gl = gh->gh_gl; | |
1122 | int ready = 0; | |
1123 | ||
1124 | spin_lock(&gl->gl_spin); | |
1125 | ||
1126 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1127 | ready = 1; | |
1128 | else if (list_empty(&gh->gh_list)) { | |
1129 | if (gh->gh_error == GLR_CANCELED) { | |
1130 | spin_unlock(&gl->gl_spin); | |
190562bd | 1131 | msleep(100); |
b3b94faa DT |
1132 | if (gfs2_glock_nq(gh)) |
1133 | return 1; | |
1134 | return 0; | |
1135 | } else | |
1136 | ready = 1; | |
1137 | } | |
1138 | ||
1139 | spin_unlock(&gl->gl_spin); | |
1140 | ||
1141 | return ready; | |
1142 | } | |
1143 | ||
1144 | /** | |
1145 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1146 | * @gh: the holder structure | |
1147 | * | |
1148 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1149 | */ | |
1150 | ||
1151 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1152 | { | |
1153 | int error; | |
1154 | ||
1155 | error = glock_wait_internal(gh); | |
1156 | if (error == GLR_CANCELED) { | |
190562bd | 1157 | msleep(100); |
b3b94faa DT |
1158 | gh->gh_flags &= ~GL_ASYNC; |
1159 | error = gfs2_glock_nq(gh); | |
1160 | } | |
1161 | ||
1162 | return error; | |
1163 | } | |
1164 | ||
1165 | /** | |
1166 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1167 | * @gh: the glock holder | |
1168 | * | |
1169 | */ | |
1170 | ||
1171 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1172 | { | |
1173 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1174 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa | 1175 | |
b3b94faa DT |
1176 | if (gh->gh_flags & GL_NOCACHE) |
1177 | handle_callback(gl, LM_ST_UNLOCKED); | |
1178 | ||
1179 | gfs2_glmutex_lock(gl); | |
1180 | ||
1181 | spin_lock(&gl->gl_spin); | |
1182 | list_del_init(&gh->gh_list); | |
1183 | ||
1184 | if (list_empty(&gl->gl_holders)) { | |
1185 | spin_unlock(&gl->gl_spin); | |
1186 | ||
1187 | if (glops->go_unlock) | |
1188 | glops->go_unlock(gh); | |
1189 | ||
b3b94faa | 1190 | spin_lock(&gl->gl_spin); |
3b8249f6 | 1191 | gl->gl_stamp = jiffies; |
b3b94faa DT |
1192 | } |
1193 | ||
1194 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1195 | run_queue(gl); | |
1196 | spin_unlock(&gl->gl_spin); | |
1197 | } | |
1198 | ||
b3b94faa DT |
1199 | /** |
1200 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1201 | * @gh: the holder structure | |
1202 | * | |
1203 | */ | |
1204 | ||
1205 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1206 | { | |
1207 | gfs2_glock_dq(gh); | |
1208 | gfs2_holder_uninit(gh); | |
1209 | } | |
1210 | ||
1211 | /** | |
1212 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1213 | * @sdp: the filesystem | |
1214 | * @number: the lock number | |
1215 | * @glops: the glock operations for the type of glock | |
1216 | * @state: the state to acquire the glock in | |
1217 | * @flags: modifier flags for the aquisition | |
1218 | * @gh: the struct gfs2_holder | |
1219 | * | |
1220 | * Returns: errno | |
1221 | */ | |
1222 | ||
cd915493 | 1223 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1224 | const struct gfs2_glock_operations *glops, |
1225 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1226 | { |
1227 | struct gfs2_glock *gl; | |
1228 | int error; | |
1229 | ||
1230 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1231 | if (!error) { | |
1232 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1233 | gfs2_glock_put(gl); | |
1234 | } | |
1235 | ||
1236 | return error; | |
1237 | } | |
1238 | ||
1239 | /** | |
1240 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1241 | * @arg_a: the first structure | |
1242 | * @arg_b: the second structure | |
1243 | * | |
1244 | */ | |
1245 | ||
1246 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1247 | { | |
a5e08a9e SW |
1248 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1249 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1250 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1251 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1252 | |
1253 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1254 | return 1; |
1255 | if (a->ln_number < b->ln_number) | |
1256 | return -1; | |
1c0f4872 | 1257 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1258 | return 0; |
b3b94faa DT |
1259 | } |
1260 | ||
1261 | /** | |
1262 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1263 | * @num_gh: the number of structures | |
1264 | * @ghs: an array of struct gfs2_holder structures | |
1265 | * | |
1266 | * Returns: 0 on success (all glocks acquired), | |
1267 | * errno on failure (no glocks acquired) | |
1268 | */ | |
1269 | ||
1270 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1271 | struct gfs2_holder **p) | |
1272 | { | |
1273 | unsigned int x; | |
1274 | int error = 0; | |
1275 | ||
1276 | for (x = 0; x < num_gh; x++) | |
1277 | p[x] = &ghs[x]; | |
1278 | ||
1279 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1280 | ||
1281 | for (x = 0; x < num_gh; x++) { | |
1282 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1283 | ||
1284 | error = gfs2_glock_nq(p[x]); | |
1285 | if (error) { | |
1286 | while (x--) | |
1287 | gfs2_glock_dq(p[x]); | |
1288 | break; | |
1289 | } | |
1290 | } | |
1291 | ||
1292 | return error; | |
1293 | } | |
1294 | ||
1295 | /** | |
1296 | * gfs2_glock_nq_m - acquire multiple glocks | |
1297 | * @num_gh: the number of structures | |
1298 | * @ghs: an array of struct gfs2_holder structures | |
1299 | * | |
1300 | * Figure out how big an impact this function has. Either: | |
1301 | * 1) Replace this code with code that calls gfs2_glock_prefetch() | |
1302 | * 2) Forget async stuff and just call nq_m_sync() | |
1303 | * 3) Leave it like it is | |
1304 | * | |
1305 | * Returns: 0 on success (all glocks acquired), | |
1306 | * errno on failure (no glocks acquired) | |
1307 | */ | |
1308 | ||
1309 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1310 | { | |
1311 | int *e; | |
1312 | unsigned int x; | |
1313 | int borked = 0, serious = 0; | |
1314 | int error = 0; | |
1315 | ||
1316 | if (!num_gh) | |
1317 | return 0; | |
1318 | ||
1319 | if (num_gh == 1) { | |
1320 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1321 | return gfs2_glock_nq(ghs); | |
1322 | } | |
1323 | ||
1324 | e = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL); | |
1325 | if (!e) | |
1326 | return -ENOMEM; | |
1327 | ||
1328 | for (x = 0; x < num_gh; x++) { | |
1329 | ghs[x].gh_flags |= LM_FLAG_TRY | GL_ASYNC; | |
1330 | error = gfs2_glock_nq(&ghs[x]); | |
1331 | if (error) { | |
1332 | borked = 1; | |
1333 | serious = error; | |
1334 | num_gh = x; | |
1335 | break; | |
1336 | } | |
1337 | } | |
1338 | ||
1339 | for (x = 0; x < num_gh; x++) { | |
1340 | error = e[x] = glock_wait_internal(&ghs[x]); | |
1341 | if (error) { | |
1342 | borked = 1; | |
1343 | if (error != GLR_TRYFAILED && error != GLR_CANCELED) | |
1344 | serious = error; | |
1345 | } | |
1346 | } | |
1347 | ||
1348 | if (!borked) { | |
1349 | kfree(e); | |
1350 | return 0; | |
1351 | } | |
1352 | ||
1353 | for (x = 0; x < num_gh; x++) | |
1354 | if (!e[x]) | |
1355 | gfs2_glock_dq(&ghs[x]); | |
1356 | ||
1357 | if (serious) | |
1358 | error = serious; | |
1359 | else { | |
1360 | for (x = 0; x < num_gh; x++) | |
1361 | gfs2_holder_reinit(ghs[x].gh_state, ghs[x].gh_flags, | |
1362 | &ghs[x]); | |
1363 | error = nq_m_sync(num_gh, ghs, (struct gfs2_holder **)e); | |
1364 | } | |
1365 | ||
1366 | kfree(e); | |
1367 | ||
1368 | return error; | |
1369 | } | |
1370 | ||
1371 | /** | |
1372 | * gfs2_glock_dq_m - release multiple glocks | |
1373 | * @num_gh: the number of structures | |
1374 | * @ghs: an array of struct gfs2_holder structures | |
1375 | * | |
1376 | */ | |
1377 | ||
1378 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1379 | { | |
1380 | unsigned int x; | |
1381 | ||
1382 | for (x = 0; x < num_gh; x++) | |
1383 | gfs2_glock_dq(&ghs[x]); | |
1384 | } | |
1385 | ||
1386 | /** | |
1387 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1388 | * @num_gh: the number of structures | |
1389 | * @ghs: an array of struct gfs2_holder structures | |
1390 | * | |
1391 | */ | |
1392 | ||
1393 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1394 | { | |
1395 | unsigned int x; | |
1396 | ||
1397 | for (x = 0; x < num_gh; x++) | |
1398 | gfs2_glock_dq_uninit(&ghs[x]); | |
1399 | } | |
1400 | ||
b3b94faa DT |
1401 | /** |
1402 | * gfs2_lvb_hold - attach a LVB from a glock | |
1403 | * @gl: The glock in question | |
1404 | * | |
1405 | */ | |
1406 | ||
1407 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1408 | { | |
1409 | int error; | |
1410 | ||
1411 | gfs2_glmutex_lock(gl); | |
1412 | ||
1413 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1414 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1415 | if (error) { | |
1416 | gfs2_glmutex_unlock(gl); | |
1417 | return error; | |
1418 | } | |
1419 | gfs2_glock_hold(gl); | |
1420 | } | |
1421 | atomic_inc(&gl->gl_lvb_count); | |
1422 | ||
1423 | gfs2_glmutex_unlock(gl); | |
1424 | ||
1425 | return 0; | |
1426 | } | |
1427 | ||
1428 | /** | |
1429 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1430 | * @gl: The glock in question | |
1431 | * | |
1432 | */ | |
1433 | ||
1434 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1435 | { | |
1436 | gfs2_glock_hold(gl); | |
1437 | gfs2_glmutex_lock(gl); | |
1438 | ||
1439 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1440 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1441 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1442 | gl->gl_lvb = NULL; | |
1443 | gfs2_glock_put(gl); | |
1444 | } | |
1445 | ||
1446 | gfs2_glmutex_unlock(gl); | |
1447 | gfs2_glock_put(gl); | |
1448 | } | |
1449 | ||
b3b94faa DT |
1450 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1451 | unsigned int state) | |
1452 | { | |
1453 | struct gfs2_glock *gl; | |
1454 | ||
1455 | gl = gfs2_glock_find(sdp, name); | |
1456 | if (!gl) | |
1457 | return; | |
1458 | ||
b3b94faa DT |
1459 | handle_callback(gl, state); |
1460 | ||
1461 | spin_lock(&gl->gl_spin); | |
1462 | run_queue(gl); | |
1463 | spin_unlock(&gl->gl_spin); | |
1464 | ||
1465 | gfs2_glock_put(gl); | |
1466 | } | |
1467 | ||
1468 | /** | |
1469 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1470 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1471 | * @type: Type of callback |
1472 | * @data: Type dependent data pointer | |
1473 | * | |
1474 | * Called by the locking module when it wants to tell us something. | |
1475 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1476 | * a journal from another client needs to be recovered. | |
1477 | */ | |
1478 | ||
9b47c11d | 1479 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1480 | { |
9b47c11d | 1481 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1482 | |
b3b94faa DT |
1483 | switch (type) { |
1484 | case LM_CB_NEED_E: | |
e7f5c01c | 1485 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1486 | return; |
1487 | ||
1488 | case LM_CB_NEED_D: | |
e7f5c01c | 1489 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1490 | return; |
1491 | ||
1492 | case LM_CB_NEED_S: | |
e7f5c01c | 1493 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1494 | return; |
1495 | ||
1496 | case LM_CB_ASYNC: { | |
e7f5c01c | 1497 | struct lm_async_cb *async = data; |
b3b94faa DT |
1498 | struct gfs2_glock *gl; |
1499 | ||
61be084e | 1500 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1501 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1502 | if (gfs2_assert_warn(sdp, gl)) | |
1503 | return; | |
1504 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1505 | gl->gl_req_bh(gl, async->lc_ret); | |
1506 | gfs2_glock_put(gl); | |
61be084e | 1507 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1508 | return; |
1509 | } | |
1510 | ||
1511 | case LM_CB_NEED_RECOVERY: | |
1512 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1513 | if (sdp->sd_recoverd_process) | |
1514 | wake_up_process(sdp->sd_recoverd_process); | |
1515 | return; | |
1516 | ||
1517 | case LM_CB_DROPLOCKS: | |
1518 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1519 | gfs2_quota_scan(sdp); | |
1520 | return; | |
1521 | ||
1522 | default: | |
1523 | gfs2_assert_warn(sdp, 0); | |
1524 | return; | |
1525 | } | |
1526 | } | |
1527 | ||
b3b94faa DT |
1528 | /** |
1529 | * demote_ok - Check to see if it's ok to unlock a glock | |
1530 | * @gl: the glock | |
1531 | * | |
1532 | * Returns: 1 if it's ok | |
1533 | */ | |
1534 | ||
1535 | static int demote_ok(struct gfs2_glock *gl) | |
1536 | { | |
8fb4b536 | 1537 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1538 | int demote = 1; |
1539 | ||
1540 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1541 | demote = 0; | |
b3b94faa DT |
1542 | else if (glops->go_demote_ok) |
1543 | demote = glops->go_demote_ok(gl); | |
1544 | ||
1545 | return demote; | |
1546 | } | |
1547 | ||
1548 | /** | |
1549 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1550 | * @gl: the glock | |
1551 | * | |
1552 | */ | |
1553 | ||
1554 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1555 | { | |
1556 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1557 | ||
1558 | spin_lock(&sdp->sd_reclaim_lock); | |
1559 | if (list_empty(&gl->gl_reclaim)) { | |
1560 | gfs2_glock_hold(gl); | |
1561 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1562 | atomic_inc(&sdp->sd_reclaim_count); | |
1563 | } | |
1564 | spin_unlock(&sdp->sd_reclaim_lock); | |
1565 | ||
1566 | wake_up(&sdp->sd_reclaim_wq); | |
1567 | } | |
1568 | ||
1569 | /** | |
1570 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1571 | * @sdp: the filesystem | |
1572 | * | |
1573 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1574 | * different glock and we notice that there are a lot of glocks in the | |
1575 | * reclaim list. | |
1576 | * | |
1577 | */ | |
1578 | ||
1579 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1580 | { | |
1581 | struct gfs2_glock *gl; | |
1582 | ||
1583 | spin_lock(&sdp->sd_reclaim_lock); | |
1584 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1585 | spin_unlock(&sdp->sd_reclaim_lock); | |
1586 | return; | |
1587 | } | |
1588 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1589 | struct gfs2_glock, gl_reclaim); | |
1590 | list_del_init(&gl->gl_reclaim); | |
1591 | spin_unlock(&sdp->sd_reclaim_lock); | |
1592 | ||
1593 | atomic_dec(&sdp->sd_reclaim_count); | |
1594 | atomic_inc(&sdp->sd_reclaimed); | |
1595 | ||
1596 | if (gfs2_glmutex_trylock(gl)) { | |
12132933 | 1597 | if (list_empty(&gl->gl_holders) && |
50299965 | 1598 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa DT |
1599 | handle_callback(gl, LM_ST_UNLOCKED); |
1600 | gfs2_glmutex_unlock(gl); | |
1601 | } | |
1602 | ||
1603 | gfs2_glock_put(gl); | |
1604 | } | |
1605 | ||
1606 | /** | |
1607 | * examine_bucket - Call a function for glock in a hash bucket | |
1608 | * @examiner: the function | |
1609 | * @sdp: the filesystem | |
1610 | * @bucket: the bucket | |
1611 | * | |
1612 | * Returns: 1 if the bucket has entries | |
1613 | */ | |
1614 | ||
1615 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1616 | unsigned int hash) |
b3b94faa | 1617 | { |
24264434 SW |
1618 | struct gfs2_glock *gl, *prev = NULL; |
1619 | int has_entries = 0; | |
b6397893 | 1620 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1621 | |
24264434 | 1622 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1623 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1624 | if (hlist_empty(head)) | |
24264434 | 1625 | goto out; |
b6397893 SW |
1626 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1627 | while(1) { | |
24264434 | 1628 | if (gl->gl_sbd == sdp) { |
b3b94faa | 1629 | gfs2_glock_hold(gl); |
24264434 SW |
1630 | read_unlock(gl_lock_addr(hash)); |
1631 | if (prev) | |
1632 | gfs2_glock_put(prev); | |
1633 | prev = gl; | |
1634 | examiner(gl); | |
a8336344 | 1635 | has_entries = 1; |
24264434 | 1636 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1637 | } |
b6397893 SW |
1638 | if (gl->gl_list.next == NULL) |
1639 | break; | |
24264434 | 1640 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1641 | } |
24264434 SW |
1642 | out: |
1643 | read_unlock(gl_lock_addr(hash)); | |
1644 | if (prev) | |
1645 | gfs2_glock_put(prev); | |
1646 | return has_entries; | |
b3b94faa DT |
1647 | } |
1648 | ||
1649 | /** | |
1650 | * scan_glock - look at a glock and see if we can reclaim it | |
1651 | * @gl: the glock to look at | |
1652 | * | |
1653 | */ | |
1654 | ||
1655 | static void scan_glock(struct gfs2_glock *gl) | |
1656 | { | |
b004157a | 1657 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1658 | return; |
a2242db0 | 1659 | |
b3b94faa | 1660 | if (gfs2_glmutex_trylock(gl)) { |
12132933 | 1661 | if (list_empty(&gl->gl_holders) && |
24264434 | 1662 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa | 1663 | goto out_schedule; |
b3b94faa DT |
1664 | gfs2_glmutex_unlock(gl); |
1665 | } | |
b3b94faa DT |
1666 | return; |
1667 | ||
627add2d | 1668 | out_schedule: |
b3b94faa DT |
1669 | gfs2_glmutex_unlock(gl); |
1670 | gfs2_glock_schedule_for_reclaim(gl); | |
b3b94faa DT |
1671 | } |
1672 | ||
1673 | /** | |
1674 | * gfs2_scand_internal - Look for glocks and inodes to toss from memory | |
1675 | * @sdp: the filesystem | |
1676 | * | |
1677 | */ | |
1678 | ||
1679 | void gfs2_scand_internal(struct gfs2_sbd *sdp) | |
1680 | { | |
1681 | unsigned int x; | |
1682 | ||
94610610 | 1683 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) |
37b2fa6a | 1684 | examine_bucket(scan_glock, sdp, x); |
b3b94faa DT |
1685 | } |
1686 | ||
1687 | /** | |
1688 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1689 | * @gl: the glock to look at | |
1690 | * | |
1691 | */ | |
1692 | ||
1693 | static void clear_glock(struct gfs2_glock *gl) | |
1694 | { | |
1695 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1696 | int released; | |
1697 | ||
1698 | spin_lock(&sdp->sd_reclaim_lock); | |
1699 | if (!list_empty(&gl->gl_reclaim)) { | |
1700 | list_del_init(&gl->gl_reclaim); | |
1701 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1702 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1703 | released = gfs2_glock_put(gl); |
1704 | gfs2_assert(sdp, !released); | |
190562bd SW |
1705 | } else { |
1706 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1707 | } |
b3b94faa DT |
1708 | |
1709 | if (gfs2_glmutex_trylock(gl)) { | |
90101c31 | 1710 | if (list_empty(&gl->gl_holders) && |
b3b94faa DT |
1711 | gl->gl_state != LM_ST_UNLOCKED) |
1712 | handle_callback(gl, LM_ST_UNLOCKED); | |
b3b94faa DT |
1713 | gfs2_glmutex_unlock(gl); |
1714 | } | |
b3b94faa DT |
1715 | } |
1716 | ||
1717 | /** | |
1718 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1719 | * @sdp: the filesystem | |
1720 | * @wait: wait until it's all gone | |
1721 | * | |
1722 | * Called when unmounting the filesystem, or when inter-node lock manager | |
1723 | * requests DROPLOCKS because it is running out of capacity. | |
1724 | */ | |
1725 | ||
1726 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
1727 | { | |
1728 | unsigned long t; | |
1729 | unsigned int x; | |
1730 | int cont; | |
1731 | ||
1732 | t = jiffies; | |
1733 | ||
1734 | for (;;) { | |
1735 | cont = 0; | |
24264434 | 1736 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1737 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1738 | cont = 1; |
24264434 | 1739 | } |
b3b94faa DT |
1740 | |
1741 | if (!wait || !cont) | |
1742 | break; | |
1743 | ||
1744 | if (time_after_eq(jiffies, | |
1745 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1746 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1747 | "Dumping lock state...\n"); | |
1748 | gfs2_dump_lockstate(sdp); | |
1749 | t = jiffies; | |
1750 | } | |
1751 | ||
61be084e | 1752 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1753 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1754 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1755 | msleep(10); |
b3b94faa DT |
1756 | } |
1757 | } | |
1758 | ||
1759 | /* | |
1760 | * Diagnostic routines to help debug distributed deadlock | |
1761 | */ | |
1762 | ||
04b933f2 RP |
1763 | static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt, |
1764 | unsigned long address) | |
1765 | { | |
7a0079d9 | 1766 | char buffer[KSYM_SYMBOL_LEN]; |
04b933f2 | 1767 | |
7a0079d9 RP |
1768 | sprint_symbol(buffer, address); |
1769 | print_dbg(gi, fmt, buffer); | |
04b933f2 RP |
1770 | } |
1771 | ||
b3b94faa DT |
1772 | /** |
1773 | * dump_holder - print information about a glock holder | |
1774 | * @str: a string naming the type of holder | |
1775 | * @gh: the glock holder | |
1776 | * | |
1777 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1778 | */ | |
1779 | ||
7c52b166 RP |
1780 | static int dump_holder(struct glock_iter *gi, char *str, |
1781 | struct gfs2_holder *gh) | |
b3b94faa DT |
1782 | { |
1783 | unsigned int x; | |
04b933f2 | 1784 | struct task_struct *gh_owner; |
b3b94faa | 1785 | |
7c52b166 | 1786 | print_dbg(gi, " %s\n", str); |
04b933f2 RP |
1787 | if (gh->gh_owner_pid) { |
1788 | print_dbg(gi, " owner = %ld ", (long)gh->gh_owner_pid); | |
1789 | gh_owner = find_task_by_pid(gh->gh_owner_pid); | |
1790 | if (gh_owner) | |
1791 | print_dbg(gi, "(%s)\n", gh_owner->comm); | |
1792 | else | |
1793 | print_dbg(gi, "(ended)\n"); | |
1794 | } else | |
1795 | print_dbg(gi, " owner = -1\n"); | |
7c52b166 RP |
1796 | print_dbg(gi, " gh_state = %u\n", gh->gh_state); |
1797 | print_dbg(gi, " gh_flags ="); | |
b3b94faa DT |
1798 | for (x = 0; x < 32; x++) |
1799 | if (gh->gh_flags & (1 << x)) | |
7c52b166 RP |
1800 | print_dbg(gi, " %u", x); |
1801 | print_dbg(gi, " \n"); | |
1802 | print_dbg(gi, " error = %d\n", gh->gh_error); | |
1803 | print_dbg(gi, " gh_iflags ="); | |
b3b94faa DT |
1804 | for (x = 0; x < 32; x++) |
1805 | if (test_bit(x, &gh->gh_iflags)) | |
7c52b166 RP |
1806 | print_dbg(gi, " %u", x); |
1807 | print_dbg(gi, " \n"); | |
04b933f2 | 1808 | gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip); |
b3b94faa | 1809 | |
7c52b166 | 1810 | return 0; |
b3b94faa DT |
1811 | } |
1812 | ||
1813 | /** | |
1814 | * dump_inode - print information about an inode | |
1815 | * @ip: the inode | |
1816 | * | |
1817 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1818 | */ | |
1819 | ||
7c52b166 | 1820 | static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip) |
b3b94faa DT |
1821 | { |
1822 | unsigned int x; | |
b3b94faa | 1823 | |
7c52b166 RP |
1824 | print_dbg(gi, " Inode:\n"); |
1825 | print_dbg(gi, " num = %llu/%llu\n", | |
dbb7cae2 SW |
1826 | (unsigned long long)ip->i_no_formal_ino, |
1827 | (unsigned long long)ip->i_no_addr); | |
7c52b166 RP |
1828 | print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode)); |
1829 | print_dbg(gi, " i_flags ="); | |
b3b94faa DT |
1830 | for (x = 0; x < 32; x++) |
1831 | if (test_bit(x, &ip->i_flags)) | |
7c52b166 RP |
1832 | print_dbg(gi, " %u", x); |
1833 | print_dbg(gi, " \n"); | |
1834 | return 0; | |
b3b94faa DT |
1835 | } |
1836 | ||
1837 | /** | |
1838 | * dump_glock - print information about a glock | |
1839 | * @gl: the glock | |
1840 | * @count: where we are in the buffer | |
1841 | * | |
1842 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1843 | */ | |
1844 | ||
7c52b166 | 1845 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl) |
b3b94faa DT |
1846 | { |
1847 | struct gfs2_holder *gh; | |
1848 | unsigned int x; | |
1849 | int error = -ENOBUFS; | |
04b933f2 | 1850 | struct task_struct *gl_owner; |
b3b94faa DT |
1851 | |
1852 | spin_lock(&gl->gl_spin); | |
1853 | ||
7c52b166 RP |
1854 | print_dbg(gi, "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type, |
1855 | (unsigned long long)gl->gl_name.ln_number); | |
1856 | print_dbg(gi, " gl_flags ="); | |
85d1da67 | 1857 | for (x = 0; x < 32; x++) { |
b3b94faa | 1858 | if (test_bit(x, &gl->gl_flags)) |
7c52b166 RP |
1859 | print_dbg(gi, " %u", x); |
1860 | } | |
04b933f2 RP |
1861 | if (!test_bit(GLF_LOCK, &gl->gl_flags)) |
1862 | print_dbg(gi, " (unlocked)"); | |
7c52b166 RP |
1863 | print_dbg(gi, " \n"); |
1864 | print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref)); | |
1865 | print_dbg(gi, " gl_state = %u\n", gl->gl_state); | |
04b933f2 RP |
1866 | if (gl->gl_owner_pid) { |
1867 | gl_owner = find_task_by_pid(gl->gl_owner_pid); | |
1868 | if (gl_owner) | |
1869 | print_dbg(gi, " gl_owner = pid %d (%s)\n", | |
1870 | gl->gl_owner_pid, gl_owner->comm); | |
1871 | else | |
1872 | print_dbg(gi, " gl_owner = %d (ended)\n", | |
1873 | gl->gl_owner_pid); | |
1874 | } else | |
1875 | print_dbg(gi, " gl_owner = -1\n"); | |
7c52b166 RP |
1876 | print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip); |
1877 | print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); | |
1878 | print_dbg(gi, " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
1879 | print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
1880 | print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
1881 | print_dbg(gi, " le = %s\n", | |
b3b94faa | 1882 | (list_empty(&gl->gl_le.le_list)) ? "no" : "yes"); |
7c52b166 RP |
1883 | print_dbg(gi, " reclaim = %s\n", |
1884 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); | |
b3b94faa | 1885 | if (gl->gl_aspace) |
7c52b166 RP |
1886 | print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, |
1887 | gl->gl_aspace->i_mapping->nrpages); | |
b3b94faa | 1888 | else |
7c52b166 RP |
1889 | print_dbg(gi, " aspace = no\n"); |
1890 | print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa | 1891 | if (gl->gl_req_gh) { |
7c52b166 | 1892 | error = dump_holder(gi, "Request", gl->gl_req_gh); |
b3b94faa DT |
1893 | if (error) |
1894 | goto out; | |
1895 | } | |
1896 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
7c52b166 | 1897 | error = dump_holder(gi, "Holder", gh); |
b3b94faa DT |
1898 | if (error) |
1899 | goto out; | |
1900 | } | |
1901 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
7c52b166 | 1902 | error = dump_holder(gi, "Waiter1", gh); |
b3b94faa DT |
1903 | if (error) |
1904 | goto out; | |
1905 | } | |
b3b94faa | 1906 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { |
7c52b166 | 1907 | error = dump_holder(gi, "Waiter3", gh); |
b3b94faa DT |
1908 | if (error) |
1909 | goto out; | |
1910 | } | |
3b8249f6 SW |
1911 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
1912 | print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n", | |
cd81a4ba RP |
1913 | gl->gl_demote_state, (unsigned long long) |
1914 | (jiffies - gl->gl_demote_time)*(1000000/HZ)); | |
3b8249f6 | 1915 | } |
5c676f6d | 1916 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa | 1917 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
7c52b166 RP |
1918 | list_empty(&gl->gl_holders)) { |
1919 | error = dump_inode(gi, gl->gl_object); | |
b3b94faa DT |
1920 | if (error) |
1921 | goto out; | |
1922 | } else { | |
1923 | error = -ENOBUFS; | |
7c52b166 | 1924 | print_dbg(gi, " Inode: busy\n"); |
b3b94faa DT |
1925 | } |
1926 | } | |
1927 | ||
1928 | error = 0; | |
1929 | ||
a91ea69f | 1930 | out: |
b3b94faa | 1931 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
1932 | return error; |
1933 | } | |
1934 | ||
1935 | /** | |
1936 | * gfs2_dump_lockstate - print out the current lockstate | |
1937 | * @sdp: the filesystem | |
1938 | * @ub: the buffer to copy the information into | |
1939 | * | |
1940 | * If @ub is NULL, dump the lockstate to the console. | |
1941 | * | |
1942 | */ | |
1943 | ||
08bc2dbc | 1944 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1945 | { |
b3b94faa | 1946 | struct gfs2_glock *gl; |
b6397893 | 1947 | struct hlist_node *h; |
b3b94faa DT |
1948 | unsigned int x; |
1949 | int error = 0; | |
1950 | ||
1951 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1952 | |
087efdd3 | 1953 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1954 | |
b6397893 | 1955 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1956 | if (gl->gl_sbd != sdp) |
1957 | continue; | |
b3b94faa | 1958 | |
7c52b166 | 1959 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1960 | if (error) |
1961 | break; | |
1962 | } | |
1963 | ||
087efdd3 | 1964 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1965 | |
1966 | if (error) | |
1967 | break; | |
1968 | } | |
1969 | ||
1970 | ||
1971 | return error; | |
1972 | } | |
1973 | ||
85d1da67 SW |
1974 | int __init gfs2_glock_init(void) |
1975 | { | |
1976 | unsigned i; | |
1977 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 1978 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 1979 | } |
087efdd3 SW |
1980 | #ifdef GL_HASH_LOCK_SZ |
1981 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
1982 | rwlock_init(&gl_hash_locks[i]); | |
1983 | } | |
1984 | #endif | |
85d1da67 SW |
1985 | return 0; |
1986 | } | |
1987 | ||
7c52b166 RP |
1988 | static int gfs2_glock_iter_next(struct glock_iter *gi) |
1989 | { | |
7a0079d9 | 1990 | read_lock(gl_lock_addr(gi->hash)); |
7c52b166 RP |
1991 | while (1) { |
1992 | if (!gi->hb_list) { /* If we don't have a hash bucket yet */ | |
1993 | gi->hb_list = &gl_hash_table[gi->hash].hb_list; | |
1994 | if (hlist_empty(gi->hb_list)) { | |
7a0079d9 | 1995 | read_unlock(gl_lock_addr(gi->hash)); |
7c52b166 | 1996 | gi->hash++; |
7a0079d9 | 1997 | read_lock(gl_lock_addr(gi->hash)); |
7c52b166 | 1998 | gi->hb_list = NULL; |
7a0079d9 RP |
1999 | if (gi->hash >= GFS2_GL_HASH_SIZE) { |
2000 | read_unlock(gl_lock_addr(gi->hash)); | |
7c52b166 | 2001 | return 1; |
7a0079d9 | 2002 | } |
7c52b166 RP |
2003 | else |
2004 | continue; | |
2005 | } | |
2006 | if (!hlist_empty(gi->hb_list)) { | |
2007 | gi->gl = list_entry(gi->hb_list->first, | |
2008 | struct gfs2_glock, | |
2009 | gl_list); | |
2010 | } | |
2011 | } else { | |
2012 | if (gi->gl->gl_list.next == NULL) { | |
7a0079d9 | 2013 | read_unlock(gl_lock_addr(gi->hash)); |
7c52b166 | 2014 | gi->hash++; |
7a0079d9 | 2015 | read_lock(gl_lock_addr(gi->hash)); |
7c52b166 RP |
2016 | gi->hb_list = NULL; |
2017 | continue; | |
2018 | } | |
2019 | gi->gl = list_entry(gi->gl->gl_list.next, | |
2020 | struct gfs2_glock, gl_list); | |
2021 | } | |
2022 | if (gi->gl) | |
2023 | break; | |
2024 | } | |
7a0079d9 | 2025 | read_unlock(gl_lock_addr(gi->hash)); |
7c52b166 RP |
2026 | return 0; |
2027 | } | |
2028 | ||
2029 | static void gfs2_glock_iter_free(struct glock_iter *gi) | |
2030 | { | |
2031 | kfree(gi); | |
2032 | } | |
2033 | ||
2034 | static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp) | |
2035 | { | |
2036 | struct glock_iter *gi; | |
2037 | ||
2038 | gi = kmalloc(sizeof (*gi), GFP_KERNEL); | |
2039 | if (!gi) | |
2040 | return NULL; | |
2041 | ||
2042 | gi->sdp = sdp; | |
2043 | gi->hash = 0; | |
2044 | gi->gl = NULL; | |
2045 | gi->hb_list = NULL; | |
2046 | gi->seq = NULL; | |
2047 | memset(gi->string, 0, sizeof(gi->string)); | |
2048 | ||
2049 | if (gfs2_glock_iter_next(gi)) { | |
2050 | gfs2_glock_iter_free(gi); | |
2051 | return NULL; | |
2052 | } | |
2053 | ||
2054 | return gi; | |
2055 | } | |
2056 | ||
2057 | static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos) | |
2058 | { | |
2059 | struct glock_iter *gi; | |
2060 | loff_t n = *pos; | |
2061 | ||
2062 | gi = gfs2_glock_iter_init(file->private); | |
2063 | if (!gi) | |
2064 | return NULL; | |
2065 | ||
2066 | while (n--) { | |
2067 | if (gfs2_glock_iter_next(gi)) { | |
2068 | gfs2_glock_iter_free(gi); | |
2069 | return NULL; | |
2070 | } | |
2071 | } | |
2072 | ||
2073 | return gi; | |
2074 | } | |
2075 | ||
2076 | static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr, | |
2077 | loff_t *pos) | |
2078 | { | |
2079 | struct glock_iter *gi = iter_ptr; | |
2080 | ||
2081 | (*pos)++; | |
2082 | ||
2083 | if (gfs2_glock_iter_next(gi)) { | |
2084 | gfs2_glock_iter_free(gi); | |
2085 | return NULL; | |
2086 | } | |
2087 | ||
2088 | return gi; | |
2089 | } | |
2090 | ||
2091 | static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr) | |
2092 | { | |
2093 | /* nothing for now */ | |
2094 | } | |
2095 | ||
2096 | static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr) | |
2097 | { | |
2098 | struct glock_iter *gi = iter_ptr; | |
2099 | ||
2100 | gi->seq = file; | |
2101 | dump_glock(gi, gi->gl); | |
2102 | ||
2103 | return 0; | |
2104 | } | |
2105 | ||
2106 | static struct seq_operations gfs2_glock_seq_ops = { | |
2107 | .start = gfs2_glock_seq_start, | |
2108 | .next = gfs2_glock_seq_next, | |
2109 | .stop = gfs2_glock_seq_stop, | |
2110 | .show = gfs2_glock_seq_show, | |
2111 | }; | |
2112 | ||
2113 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
2114 | { | |
2115 | struct seq_file *seq; | |
2116 | int ret; | |
2117 | ||
2118 | ret = seq_open(file, &gfs2_glock_seq_ops); | |
2119 | if (ret) | |
2120 | return ret; | |
2121 | ||
2122 | seq = file->private_data; | |
2123 | seq->private = inode->i_private; | |
2124 | ||
2125 | return 0; | |
2126 | } | |
2127 | ||
2128 | static const struct file_operations gfs2_debug_fops = { | |
2129 | .owner = THIS_MODULE, | |
2130 | .open = gfs2_debugfs_open, | |
2131 | .read = seq_read, | |
2132 | .llseek = seq_lseek, | |
2133 | .release = seq_release | |
2134 | }; | |
2135 | ||
2136 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
2137 | { | |
5f882096 RP |
2138 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
2139 | if (!sdp->debugfs_dir) | |
2140 | return -ENOMEM; | |
2141 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
2142 | S_IFREG | S_IRUGO, | |
2143 | sdp->debugfs_dir, sdp, | |
2144 | &gfs2_debug_fops); | |
2145 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
2146 | return -ENOMEM; |
2147 | ||
2148 | return 0; | |
2149 | } | |
2150 | ||
2151 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
2152 | { | |
5f882096 RP |
2153 | if (sdp && sdp->debugfs_dir) { |
2154 | if (sdp->debugfs_dentry_glocks) { | |
2155 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
2156 | sdp->debugfs_dentry_glocks = NULL; | |
2157 | } | |
2158 | debugfs_remove(sdp->debugfs_dir); | |
2159 | sdp->debugfs_dir = NULL; | |
2160 | } | |
7c52b166 RP |
2161 | } |
2162 | ||
2163 | int gfs2_register_debugfs(void) | |
2164 | { | |
2165 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
2166 | return gfs2_root ? 0 : -ENOMEM; | |
2167 | } | |
2168 | ||
2169 | void gfs2_unregister_debugfs(void) | |
2170 | { | |
2171 | debugfs_remove(gfs2_root); | |
5f882096 | 2172 | gfs2_root = NULL; |
7c52b166 | 2173 | } |