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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> | |
8fbbfd21 SW |
28 | #include <linux/kthread.h> |
29 | #include <linux/freezer.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 */ | |
7c52b166 RP |
51 | struct seq_file *seq; /* sequence file for debugfs */ |
52 | char string[512]; /* scratch space */ | |
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); |
04b933f2 | 58 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl); |
3b8249f6 | 59 | static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh); |
b5d32bea | 60 | static void gfs2_glock_drop_th(struct gfs2_glock *gl); |
61be084e | 61 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
7c52b166 | 62 | static struct dentry *gfs2_root; |
8fbbfd21 SW |
63 | static struct task_struct *scand_process; |
64 | static unsigned int scand_secs = 5; | |
08bc2dbc | 65 | |
b6397893 | 66 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
67 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
68 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
69 | ||
85d1da67 | 70 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 71 | static struct dentry *gfs2_root; |
087efdd3 SW |
72 | |
73 | /* | |
74 | * Despite what you might think, the numbers below are not arbitrary :-) | |
75 | * They are taken from the ipv4 routing hash code, which is well tested | |
76 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
77 | * but for now this should be fine. | |
78 | * | |
79 | * The reason for putting the locks in a separate array from the list heads | |
80 | * is that we can have fewer locks than list heads and save memory. We use | |
81 | * the same hash function for both, but with a different hash mask. | |
82 | */ | |
83 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
84 | defined(CONFIG_PROVE_LOCKING) | |
85 | ||
86 | #ifdef CONFIG_LOCKDEP | |
87 | # define GL_HASH_LOCK_SZ 256 | |
88 | #else | |
89 | # if NR_CPUS >= 32 | |
90 | # define GL_HASH_LOCK_SZ 4096 | |
91 | # elif NR_CPUS >= 16 | |
92 | # define GL_HASH_LOCK_SZ 2048 | |
93 | # elif NR_CPUS >= 8 | |
94 | # define GL_HASH_LOCK_SZ 1024 | |
95 | # elif NR_CPUS >= 4 | |
96 | # define GL_HASH_LOCK_SZ 512 | |
97 | # else | |
98 | # define GL_HASH_LOCK_SZ 256 | |
99 | # endif | |
100 | #endif | |
101 | ||
102 | /* We never want more locks than chains */ | |
103 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
104 | # undef GL_HASH_LOCK_SZ | |
105 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
106 | #endif | |
107 | ||
108 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
109 | ||
110 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
111 | { | |
94610610 | 112 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
113 | } |
114 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 115 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
116 | { |
117 | return NULL; | |
118 | } | |
119 | #endif | |
85d1da67 | 120 | |
b3b94faa DT |
121 | /** |
122 | * relaxed_state_ok - is a requested lock compatible with the current lock mode? | |
123 | * @actual: the current state of the lock | |
124 | * @requested: the lock state that was requested by the caller | |
125 | * @flags: the modifier flags passed in by the caller | |
126 | * | |
127 | * Returns: 1 if the locks are compatible, 0 otherwise | |
128 | */ | |
129 | ||
130 | static inline int relaxed_state_ok(unsigned int actual, unsigned requested, | |
131 | int flags) | |
132 | { | |
133 | if (actual == requested) | |
134 | return 1; | |
135 | ||
136 | if (flags & GL_EXACT) | |
137 | return 0; | |
138 | ||
139 | if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) | |
140 | return 1; | |
141 | ||
142 | if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) | |
143 | return 1; | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | /** | |
149 | * gl_hash() - Turn glock number into hash bucket number | |
150 | * @lock: The glock number | |
151 | * | |
152 | * Returns: The number of the corresponding hash bucket | |
153 | */ | |
154 | ||
b8547856 SW |
155 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
156 | const struct lm_lockname *name) | |
b3b94faa DT |
157 | { |
158 | unsigned int h; | |
159 | ||
cd915493 | 160 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 161 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 162 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
163 | h &= GFS2_GL_HASH_MASK; |
164 | ||
165 | return h; | |
166 | } | |
167 | ||
168 | /** | |
169 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
170 | * @gl: The glock to release | |
171 | * | |
172 | * Also calls lock module to release its internal structure for this glock. | |
173 | * | |
174 | */ | |
175 | ||
176 | static void glock_free(struct gfs2_glock *gl) | |
177 | { | |
178 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
179 | struct inode *aspace = gl->gl_aspace; | |
180 | ||
181 | gfs2_lm_put_lock(sdp, gl->gl_lock); | |
182 | ||
183 | if (aspace) | |
184 | gfs2_aspace_put(aspace); | |
185 | ||
186 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
187 | } |
188 | ||
189 | /** | |
190 | * gfs2_glock_hold() - increment reference count on glock | |
191 | * @gl: The glock to hold | |
192 | * | |
193 | */ | |
194 | ||
195 | void gfs2_glock_hold(struct gfs2_glock *gl) | |
196 | { | |
16feb9fe | 197 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
198 | } |
199 | ||
200 | /** | |
201 | * gfs2_glock_put() - Decrement reference count on glock | |
202 | * @gl: The glock to put | |
203 | * | |
204 | */ | |
205 | ||
206 | int gfs2_glock_put(struct gfs2_glock *gl) | |
207 | { | |
b3b94faa | 208 | int rv = 0; |
16feb9fe | 209 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b3b94faa | 210 | |
087efdd3 | 211 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 212 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 213 | hlist_del(&gl->gl_list); |
087efdd3 | 214 | write_unlock(gl_lock_addr(gl->gl_hash)); |
190562bd | 215 | BUG_ON(spin_is_locked(&gl->gl_spin)); |
16feb9fe SW |
216 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); |
217 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
218 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
219 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
16feb9fe | 220 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); |
b3b94faa DT |
221 | glock_free(gl); |
222 | rv = 1; | |
223 | goto out; | |
224 | } | |
087efdd3 | 225 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 226 | out: |
b3b94faa DT |
227 | return rv; |
228 | } | |
229 | ||
b3b94faa DT |
230 | /** |
231 | * search_bucket() - Find struct gfs2_glock by lock number | |
232 | * @bucket: the bucket to search | |
233 | * @name: The lock name | |
234 | * | |
235 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
236 | */ | |
237 | ||
37b2fa6a | 238 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 239 | const struct gfs2_sbd *sdp, |
d6a53727 | 240 | const struct lm_lockname *name) |
b3b94faa DT |
241 | { |
242 | struct gfs2_glock *gl; | |
b6397893 | 243 | struct hlist_node *h; |
b3b94faa | 244 | |
b6397893 | 245 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
246 | if (!lm_name_equal(&gl->gl_name, name)) |
247 | continue; | |
899be4d3 SW |
248 | if (gl->gl_sbd != sdp) |
249 | continue; | |
b3b94faa | 250 | |
16feb9fe | 251 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
252 | |
253 | return gl; | |
254 | } | |
255 | ||
256 | return NULL; | |
257 | } | |
258 | ||
259 | /** | |
260 | * gfs2_glock_find() - Find glock by lock number | |
261 | * @sdp: The GFS2 superblock | |
262 | * @name: The lock name | |
263 | * | |
264 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
265 | */ | |
266 | ||
85d1da67 | 267 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 268 | const struct lm_lockname *name) |
b3b94faa | 269 | { |
37b2fa6a | 270 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
271 | struct gfs2_glock *gl; |
272 | ||
087efdd3 | 273 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 274 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 275 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
276 | |
277 | return gl; | |
278 | } | |
279 | ||
280 | /** | |
281 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
282 | * @sdp: The GFS2 superblock | |
283 | * @number: the lock number | |
284 | * @glops: The glock_operations to use | |
285 | * @create: If 0, don't create the glock if it doesn't exist | |
286 | * @glp: the glock is returned here | |
287 | * | |
288 | * This does not lock a glock, just finds/creates structures for one. | |
289 | * | |
290 | * Returns: errno | |
291 | */ | |
292 | ||
cd915493 | 293 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 294 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
295 | struct gfs2_glock **glp) |
296 | { | |
37b2fa6a | 297 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 298 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 299 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
300 | int error; |
301 | ||
087efdd3 | 302 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 303 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 304 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
305 | |
306 | if (gl || !create) { | |
307 | *glp = gl; | |
308 | return 0; | |
309 | } | |
310 | ||
311 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
312 | if (!gl) | |
313 | return -ENOMEM; | |
314 | ||
ec45d9f5 | 315 | gl->gl_flags = 0; |
b3b94faa | 316 | gl->gl_name = name; |
16feb9fe | 317 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 318 | gl->gl_state = LM_ST_UNLOCKED; |
37b2fa6a | 319 | gl->gl_hash = hash; |
04b933f2 | 320 | gl->gl_owner_pid = 0; |
320dd101 | 321 | gl->gl_ip = 0; |
b3b94faa | 322 | gl->gl_ops = glops; |
ec45d9f5 SW |
323 | gl->gl_req_gh = NULL; |
324 | gl->gl_req_bh = NULL; | |
325 | gl->gl_vn = 0; | |
326 | gl->gl_stamp = jiffies; | |
327 | gl->gl_object = NULL; | |
b3b94faa | 328 | gl->gl_sbd = sdp; |
ec45d9f5 | 329 | gl->gl_aspace = NULL; |
b3b94faa | 330 | lops_init_le(&gl->gl_le, &gfs2_glock_lops); |
b3b94faa DT |
331 | |
332 | /* If this glock protects actual on-disk data or metadata blocks, | |
333 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 334 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
335 | gl->gl_aspace = gfs2_aspace_get(sdp); |
336 | if (!gl->gl_aspace) { | |
337 | error = -ENOMEM; | |
338 | goto fail; | |
339 | } | |
340 | } | |
341 | ||
342 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
343 | if (error) | |
344 | goto fail_aspace; | |
345 | ||
087efdd3 | 346 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 347 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 348 | if (tmp) { |
087efdd3 | 349 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
350 | glock_free(gl); |
351 | gl = tmp; | |
352 | } else { | |
b6397893 | 353 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 354 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
355 | } |
356 | ||
357 | *glp = gl; | |
358 | ||
359 | return 0; | |
360 | ||
ec45d9f5 | 361 | fail_aspace: |
b3b94faa DT |
362 | if (gl->gl_aspace) |
363 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 364 | fail: |
907b9bce | 365 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
366 | return error; |
367 | } | |
368 | ||
369 | /** | |
370 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
371 | * @gl: the glock | |
372 | * @state: the state we're requesting | |
373 | * @flags: the modifier flags | |
374 | * @gh: the holder structure | |
375 | * | |
376 | */ | |
377 | ||
190562bd | 378 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
379 | struct gfs2_holder *gh) |
380 | { | |
381 | INIT_LIST_HEAD(&gh->gh_list); | |
382 | gh->gh_gl = gl; | |
d0dc80db | 383 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
04b933f2 | 384 | gh->gh_owner_pid = current->pid; |
b3b94faa DT |
385 | gh->gh_state = state; |
386 | gh->gh_flags = flags; | |
387 | gh->gh_error = 0; | |
388 | gh->gh_iflags = 0; | |
b3b94faa DT |
389 | gfs2_glock_hold(gl); |
390 | } | |
391 | ||
392 | /** | |
393 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
394 | * @state: the state we're requesting | |
395 | * @flags: the modifier flags | |
396 | * @gh: the holder structure | |
397 | * | |
398 | * Don't mess with the glock. | |
399 | * | |
400 | */ | |
401 | ||
190562bd | 402 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
403 | { |
404 | gh->gh_state = state; | |
579b78a4 | 405 | gh->gh_flags = flags; |
3b8249f6 | 406 | gh->gh_iflags = 0; |
d0dc80db | 407 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
408 | } |
409 | ||
410 | /** | |
411 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
412 | * @gh: the holder structure | |
413 | * | |
414 | */ | |
415 | ||
416 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
417 | { | |
418 | gfs2_glock_put(gh->gh_gl); | |
419 | gh->gh_gl = NULL; | |
d0dc80db | 420 | gh->gh_ip = 0; |
b3b94faa DT |
421 | } |
422 | ||
3b8249f6 | 423 | static void gfs2_holder_wake(struct gfs2_holder *gh) |
fee852e3 | 424 | { |
fee852e3 | 425 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
d93cfa98 | 426 | smp_mb__after_clear_bit(); |
fee852e3 SW |
427 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); |
428 | } | |
429 | ||
d93cfa98 | 430 | static int just_schedule(void *word) |
fee852e3 SW |
431 | { |
432 | schedule(); | |
433 | return 0; | |
434 | } | |
435 | ||
436 | static void wait_on_holder(struct gfs2_holder *gh) | |
437 | { | |
438 | might_sleep(); | |
d93cfa98 AD |
439 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE); |
440 | } | |
441 | ||
442 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
443 | { | |
444 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
445 | smp_mb__after_clear_bit(); | |
446 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
447 | } | |
448 | ||
449 | static void wait_on_demote(struct gfs2_glock *gl) | |
450 | { | |
451 | might_sleep(); | |
452 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE); | |
fee852e3 SW |
453 | } |
454 | ||
b3b94faa DT |
455 | /** |
456 | * rq_mutex - process a mutex request in the queue | |
457 | * @gh: the glock holder | |
458 | * | |
459 | * Returns: 1 if the queue is blocked | |
460 | */ | |
461 | ||
462 | static int rq_mutex(struct gfs2_holder *gh) | |
463 | { | |
464 | struct gfs2_glock *gl = gh->gh_gl; | |
465 | ||
466 | list_del_init(&gh->gh_list); | |
467 | /* gh->gh_error never examined. */ | |
468 | set_bit(GLF_LOCK, &gl->gl_flags); | |
d043e190 | 469 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
fee852e3 SW |
470 | smp_mb(); |
471 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
b3b94faa DT |
472 | |
473 | return 1; | |
474 | } | |
475 | ||
476 | /** | |
477 | * rq_promote - process a promote request in the queue | |
478 | * @gh: the glock holder | |
479 | * | |
480 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
481 | * | |
482 | * Returns: 1 if the queue is blocked | |
483 | */ | |
484 | ||
485 | static int rq_promote(struct gfs2_holder *gh) | |
486 | { | |
487 | struct gfs2_glock *gl = gh->gh_gl; | |
488 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa DT |
489 | |
490 | if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
491 | if (list_empty(&gl->gl_holders)) { | |
492 | gl->gl_req_gh = gh; | |
493 | set_bit(GLF_LOCK, &gl->gl_flags); | |
494 | spin_unlock(&gl->gl_spin); | |
495 | ||
496 | if (atomic_read(&sdp->sd_reclaim_count) > | |
497 | gfs2_tune_get(sdp, gt_reclaim_limit) && | |
498 | !(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
499 | gfs2_reclaim_glock(sdp); | |
500 | gfs2_reclaim_glock(sdp); | |
501 | } | |
502 | ||
3b8249f6 | 503 | gfs2_glock_xmote_th(gh->gh_gl, gh); |
b3b94faa DT |
504 | spin_lock(&gl->gl_spin); |
505 | } | |
506 | return 1; | |
507 | } | |
508 | ||
509 | if (list_empty(&gl->gl_holders)) { | |
510 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
511 | set_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
512 | } else { |
513 | struct gfs2_holder *next_gh; | |
1c0f4872 | 514 | if (gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa DT |
515 | return 1; |
516 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
517 | gh_list); | |
1c0f4872 | 518 | if (next_gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa | 519 | return 1; |
b3b94faa DT |
520 | } |
521 | ||
522 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
523 | gh->gh_error = 0; | |
524 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
525 | ||
3b8249f6 | 526 | gfs2_holder_wake(gh); |
b3b94faa DT |
527 | |
528 | return 0; | |
529 | } | |
530 | ||
531 | /** | |
532 | * rq_demote - process a demote request in the queue | |
533 | * @gh: the glock holder | |
534 | * | |
535 | * Returns: 1 if the queue is blocked | |
536 | */ | |
537 | ||
3b8249f6 | 538 | static int rq_demote(struct gfs2_glock *gl) |
b3b94faa | 539 | { |
b3b94faa DT |
540 | if (!list_empty(&gl->gl_holders)) |
541 | return 1; | |
542 | ||
3b8249f6 SW |
543 | if (gl->gl_state == gl->gl_demote_state || |
544 | gl->gl_state == LM_ST_UNLOCKED) { | |
d93cfa98 | 545 | gfs2_demote_wake(gl); |
3b8249f6 | 546 | return 0; |
b3b94faa | 547 | } |
3b8249f6 | 548 | set_bit(GLF_LOCK, &gl->gl_flags); |
3b8249f6 | 549 | if (gl->gl_demote_state == LM_ST_UNLOCKED || |
87124e58 SW |
550 | gl->gl_state != LM_ST_EXCLUSIVE) { |
551 | spin_unlock(&gl->gl_spin); | |
3b8249f6 | 552 | gfs2_glock_drop_th(gl); |
87124e58 SW |
553 | } else { |
554 | spin_unlock(&gl->gl_spin); | |
3b8249f6 | 555 | gfs2_glock_xmote_th(gl, NULL); |
87124e58 | 556 | } |
3b8249f6 | 557 | spin_lock(&gl->gl_spin); |
b3b94faa DT |
558 | |
559 | return 0; | |
560 | } | |
561 | ||
b3b94faa DT |
562 | /** |
563 | * run_queue - process holder structures on a glock | |
564 | * @gl: the glock | |
565 | * | |
566 | */ | |
b3b94faa DT |
567 | static void run_queue(struct gfs2_glock *gl) |
568 | { | |
569 | struct gfs2_holder *gh; | |
570 | int blocked = 1; | |
571 | ||
572 | for (;;) { | |
573 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
574 | break; | |
575 | ||
576 | if (!list_empty(&gl->gl_waiters1)) { | |
577 | gh = list_entry(gl->gl_waiters1.next, | |
578 | struct gfs2_holder, gh_list); | |
579 | ||
580 | if (test_bit(HIF_MUTEX, &gh->gh_iflags)) | |
581 | blocked = rq_mutex(gh); | |
582 | else | |
583 | gfs2_assert_warn(gl->gl_sbd, 0); | |
584 | ||
3b8249f6 SW |
585 | } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
586 | blocked = rq_demote(gl); | |
b3b94faa DT |
587 | } else if (!list_empty(&gl->gl_waiters3)) { |
588 | gh = list_entry(gl->gl_waiters3.next, | |
589 | struct gfs2_holder, gh_list); | |
590 | ||
591 | if (test_bit(HIF_PROMOTE, &gh->gh_iflags)) | |
592 | blocked = rq_promote(gh); | |
593 | else | |
594 | gfs2_assert_warn(gl->gl_sbd, 0); | |
595 | ||
596 | } else | |
597 | break; | |
598 | ||
599 | if (blocked) | |
600 | break; | |
601 | } | |
602 | } | |
603 | ||
604 | /** | |
605 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
606 | * @gl: the glock | |
607 | * | |
608 | * Gives caller exclusive access to manipulate a glock structure. | |
609 | */ | |
610 | ||
feaa7bba | 611 | static void gfs2_glmutex_lock(struct gfs2_glock *gl) |
b3b94faa DT |
612 | { |
613 | struct gfs2_holder gh; | |
614 | ||
615 | gfs2_holder_init(gl, 0, 0, &gh); | |
616 | set_bit(HIF_MUTEX, &gh.gh_iflags); | |
fee852e3 SW |
617 | if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags)) |
618 | BUG(); | |
b3b94faa DT |
619 | |
620 | spin_lock(&gl->gl_spin); | |
85d1da67 | 621 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 622 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); |
85d1da67 | 623 | } else { |
04b933f2 | 624 | gl->gl_owner_pid = current->pid; |
320dd101 | 625 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
fee852e3 SW |
626 | clear_bit(HIF_WAIT, &gh.gh_iflags); |
627 | smp_mb(); | |
628 | wake_up_bit(&gh.gh_iflags, HIF_WAIT); | |
320dd101 | 629 | } |
b3b94faa DT |
630 | spin_unlock(&gl->gl_spin); |
631 | ||
fee852e3 | 632 | wait_on_holder(&gh); |
b3b94faa DT |
633 | gfs2_holder_uninit(&gh); |
634 | } | |
635 | ||
636 | /** | |
637 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
638 | * @gl: the glock | |
639 | * | |
640 | * Returns: 1 if the glock is acquired | |
641 | */ | |
642 | ||
08bc2dbc | 643 | static int gfs2_glmutex_trylock(struct gfs2_glock *gl) |
b3b94faa DT |
644 | { |
645 | int acquired = 1; | |
646 | ||
647 | spin_lock(&gl->gl_spin); | |
85d1da67 | 648 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 649 | acquired = 0; |
85d1da67 | 650 | } else { |
04b933f2 | 651 | gl->gl_owner_pid = current->pid; |
320dd101 SW |
652 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
653 | } | |
b3b94faa DT |
654 | spin_unlock(&gl->gl_spin); |
655 | ||
656 | return acquired; | |
657 | } | |
658 | ||
659 | /** | |
660 | * gfs2_glmutex_unlock - release a local lock on a glock | |
661 | * @gl: the glock | |
662 | * | |
663 | */ | |
664 | ||
feaa7bba | 665 | static void gfs2_glmutex_unlock(struct gfs2_glock *gl) |
b3b94faa DT |
666 | { |
667 | spin_lock(&gl->gl_spin); | |
668 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
04b933f2 | 669 | gl->gl_owner_pid = 0; |
320dd101 | 670 | gl->gl_ip = 0; |
b3b94faa | 671 | run_queue(gl); |
190562bd | 672 | BUG_ON(!spin_is_locked(&gl->gl_spin)); |
b3b94faa DT |
673 | spin_unlock(&gl->gl_spin); |
674 | } | |
675 | ||
676 | /** | |
3b8249f6 | 677 | * handle_callback - process a demote request |
b3b94faa DT |
678 | * @gl: the glock |
679 | * @state: the state the caller wants us to change to | |
680 | * | |
3b8249f6 SW |
681 | * There are only two requests that we are going to see in actual |
682 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
683 | */ |
684 | ||
d93cfa98 | 685 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, int remote) |
b3b94faa | 686 | { |
b3b94faa | 687 | spin_lock(&gl->gl_spin); |
3b8249f6 SW |
688 | if (test_and_set_bit(GLF_DEMOTE, &gl->gl_flags) == 0) { |
689 | gl->gl_demote_state = state; | |
690 | gl->gl_demote_time = jiffies; | |
d93cfa98 AD |
691 | if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN && |
692 | gl->gl_object) { | |
693 | struct inode *inode = igrab(gl->gl_object); | |
694 | spin_unlock(&gl->gl_spin); | |
695 | if (inode) { | |
696 | d_prune_aliases(inode); | |
697 | iput(inode); | |
698 | } | |
699 | return; | |
700 | } | |
26caee5b JW |
701 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
702 | gl->gl_demote_state != state) { | |
703 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 704 | } |
b3b94faa | 705 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
706 | } |
707 | ||
708 | /** | |
709 | * state_change - record that the glock is now in a different state | |
710 | * @gl: the glock | |
711 | * @new_state the new state | |
712 | * | |
713 | */ | |
714 | ||
715 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
716 | { | |
b3b94faa DT |
717 | int held1, held2; |
718 | ||
719 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
720 | held2 = (new_state != LM_ST_UNLOCKED); | |
721 | ||
722 | if (held1 != held2) { | |
6a6b3d01 | 723 | if (held2) |
b3b94faa | 724 | gfs2_glock_hold(gl); |
6a6b3d01 | 725 | else |
b3b94faa | 726 | gfs2_glock_put(gl); |
b3b94faa DT |
727 | } |
728 | ||
729 | gl->gl_state = new_state; | |
730 | } | |
731 | ||
732 | /** | |
733 | * xmote_bh - Called after the lock module is done acquiring a lock | |
734 | * @gl: The glock in question | |
735 | * @ret: the int returned from the lock module | |
736 | * | |
737 | */ | |
738 | ||
739 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
740 | { | |
741 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 742 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
743 | struct gfs2_holder *gh = gl->gl_req_gh; |
744 | int prev_state = gl->gl_state; | |
745 | int op_done = 1; | |
746 | ||
747 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
12132933 | 748 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
749 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); |
750 | ||
751 | state_change(gl, ret & LM_OUT_ST_MASK); | |
752 | ||
753 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
754 | if (glops->go_inval) | |
1a14d3a6 | 755 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
756 | } else if (gl->gl_state == LM_ST_DEFERRED) { |
757 | /* We might not want to do this here. | |
758 | Look at moving to the inode glops. */ | |
759 | if (glops->go_inval) | |
1a14d3a6 | 760 | glops->go_inval(gl, 0); |
b3b94faa DT |
761 | } |
762 | ||
763 | /* Deal with each possible exit condition */ | |
764 | ||
3b8249f6 | 765 | if (!gh) { |
b3b94faa | 766 | gl->gl_stamp = jiffies; |
87124e58 | 767 | if (ret & LM_OUT_CANCELED) { |
3b8249f6 | 768 | op_done = 0; |
87124e58 SW |
769 | } else { |
770 | spin_lock(&gl->gl_spin); | |
771 | if (gl->gl_state != gl->gl_demote_state) { | |
772 | gl->gl_req_bh = NULL; | |
773 | spin_unlock(&gl->gl_spin); | |
774 | gfs2_glock_drop_th(gl); | |
775 | gfs2_glock_put(gl); | |
776 | return; | |
777 | } | |
d93cfa98 | 778 | gfs2_demote_wake(gl); |
87124e58 SW |
779 | spin_unlock(&gl->gl_spin); |
780 | } | |
3b8249f6 | 781 | } else { |
b3b94faa DT |
782 | spin_lock(&gl->gl_spin); |
783 | list_del_init(&gh->gh_list); | |
784 | gh->gh_error = -EIO; | |
3b8249f6 SW |
785 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
786 | goto out; | |
787 | gh->gh_error = GLR_CANCELED; | |
788 | if (ret & LM_OUT_CANCELED) | |
789 | goto out; | |
790 | if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
791 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
b3b94faa | 792 | gh->gh_error = 0; |
3b8249f6 SW |
793 | set_bit(HIF_HOLDER, &gh->gh_iflags); |
794 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
795 | op_done = 0; | |
796 | goto out; | |
b3b94faa | 797 | } |
b3b94faa | 798 | gh->gh_error = GLR_TRYFAILED; |
3b8249f6 SW |
799 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
800 | goto out; | |
801 | gh->gh_error = -EINVAL; | |
b3b94faa DT |
802 | if (gfs2_assert_withdraw(sdp, 0) == -1) |
803 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
3b8249f6 SW |
804 | out: |
805 | spin_unlock(&gl->gl_spin); | |
b3b94faa DT |
806 | } |
807 | ||
808 | if (glops->go_xmote_bh) | |
809 | glops->go_xmote_bh(gl); | |
810 | ||
811 | if (op_done) { | |
812 | spin_lock(&gl->gl_spin); | |
813 | gl->gl_req_gh = NULL; | |
814 | gl->gl_req_bh = NULL; | |
815 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
816 | run_queue(gl); | |
817 | spin_unlock(&gl->gl_spin); | |
818 | } | |
819 | ||
820 | gfs2_glock_put(gl); | |
821 | ||
fee852e3 | 822 | if (gh) |
3b8249f6 | 823 | gfs2_holder_wake(gh); |
b3b94faa DT |
824 | } |
825 | ||
826 | /** | |
827 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
828 | * @gl: The glock in question | |
829 | * @state: the requested state | |
830 | * @flags: modifier flags to the lock call | |
831 | * | |
832 | */ | |
833 | ||
87124e58 | 834 | static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh) |
b3b94faa DT |
835 | { |
836 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
3b8249f6 SW |
837 | int flags = gh ? gh->gh_flags : 0; |
838 | unsigned state = gh ? gh->gh_state : gl->gl_demote_state; | |
8fb4b536 | 839 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
840 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | |
841 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
842 | LM_FLAG_PRIORITY); | |
843 | unsigned int lck_ret; | |
844 | ||
b5d32bea SW |
845 | if (glops->go_xmote_th) |
846 | glops->go_xmote_th(gl); | |
847 | ||
b3b94faa | 848 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 849 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
850 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); |
851 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
852 | ||
b3b94faa DT |
853 | gfs2_glock_hold(gl); |
854 | gl->gl_req_bh = xmote_bh; | |
855 | ||
ec45d9f5 | 856 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); |
b3b94faa DT |
857 | |
858 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
859 | return; | |
860 | ||
861 | if (lck_ret & LM_OUT_ASYNC) | |
862 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
863 | else | |
864 | xmote_bh(gl, lck_ret); | |
865 | } | |
866 | ||
867 | /** | |
868 | * drop_bh - Called after a lock module unlock completes | |
869 | * @gl: the glock | |
870 | * @ret: the return status | |
871 | * | |
872 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
873 | * Doesn't drop the reference on the glock the top half took out | |
874 | * | |
875 | */ | |
876 | ||
877 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
878 | { | |
879 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 880 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
881 | struct gfs2_holder *gh = gl->gl_req_gh; |
882 | ||
b3b94faa | 883 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 884 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
885 | gfs2_assert_warn(sdp, !ret); |
886 | ||
887 | state_change(gl, LM_ST_UNLOCKED); | |
d93cfa98 | 888 | gfs2_demote_wake(gl); |
b3b94faa DT |
889 | |
890 | if (glops->go_inval) | |
1a14d3a6 | 891 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
892 | |
893 | if (gh) { | |
894 | spin_lock(&gl->gl_spin); | |
895 | list_del_init(&gh->gh_list); | |
896 | gh->gh_error = 0; | |
897 | spin_unlock(&gl->gl_spin); | |
898 | } | |
899 | ||
b3b94faa DT |
900 | spin_lock(&gl->gl_spin); |
901 | gl->gl_req_gh = NULL; | |
902 | gl->gl_req_bh = NULL; | |
903 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
904 | run_queue(gl); | |
905 | spin_unlock(&gl->gl_spin); | |
906 | ||
907 | gfs2_glock_put(gl); | |
908 | ||
fee852e3 | 909 | if (gh) |
3b8249f6 | 910 | gfs2_holder_wake(gh); |
b3b94faa DT |
911 | } |
912 | ||
913 | /** | |
914 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
915 | * @gl: the glock | |
916 | * | |
917 | */ | |
918 | ||
b5d32bea | 919 | static void gfs2_glock_drop_th(struct gfs2_glock *gl) |
b3b94faa DT |
920 | { |
921 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 922 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
923 | unsigned int ret; |
924 | ||
b5d32bea SW |
925 | if (glops->go_drop_th) |
926 | glops->go_drop_th(gl); | |
927 | ||
b3b94faa | 928 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 929 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
930 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); |
931 | ||
b3b94faa DT |
932 | gfs2_glock_hold(gl); |
933 | gl->gl_req_bh = drop_bh; | |
934 | ||
b3b94faa DT |
935 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
936 | ||
937 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
938 | return; | |
939 | ||
940 | if (!ret) | |
941 | drop_bh(gl, ret); | |
942 | else | |
943 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
944 | } | |
945 | ||
946 | /** | |
947 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
948 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
949 | * | |
950 | * Don't cancel GL_NOCANCEL requests. | |
951 | */ | |
952 | ||
953 | static void do_cancels(struct gfs2_holder *gh) | |
954 | { | |
955 | struct gfs2_glock *gl = gh->gh_gl; | |
956 | ||
957 | spin_lock(&gl->gl_spin); | |
958 | ||
959 | while (gl->gl_req_gh != gh && | |
960 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
961 | !list_empty(&gh->gh_list)) { | |
50299965 SW |
962 | if (gl->gl_req_bh && !(gl->gl_req_gh && |
963 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
b3b94faa DT |
964 | spin_unlock(&gl->gl_spin); |
965 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
966 | msleep(100); | |
967 | spin_lock(&gl->gl_spin); | |
968 | } else { | |
969 | spin_unlock(&gl->gl_spin); | |
970 | msleep(100); | |
971 | spin_lock(&gl->gl_spin); | |
972 | } | |
973 | } | |
974 | ||
975 | spin_unlock(&gl->gl_spin); | |
976 | } | |
977 | ||
978 | /** | |
979 | * glock_wait_internal - wait on a glock acquisition | |
980 | * @gh: the glock holder | |
981 | * | |
982 | * Returns: 0 on success | |
983 | */ | |
984 | ||
985 | static int glock_wait_internal(struct gfs2_holder *gh) | |
986 | { | |
987 | struct gfs2_glock *gl = gh->gh_gl; | |
988 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 989 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
990 | |
991 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
992 | return -EIO; | |
993 | ||
994 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
995 | spin_lock(&gl->gl_spin); | |
996 | if (gl->gl_req_gh != gh && | |
997 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
998 | !list_empty(&gh->gh_list)) { | |
999 | list_del_init(&gh->gh_list); | |
1000 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
1001 | run_queue(gl); |
1002 | spin_unlock(&gl->gl_spin); | |
1003 | return gh->gh_error; | |
1004 | } | |
1005 | spin_unlock(&gl->gl_spin); | |
1006 | } | |
1007 | ||
1008 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1009 | do_cancels(gh); | |
1010 | ||
fee852e3 | 1011 | wait_on_holder(gh); |
b3b94faa DT |
1012 | if (gh->gh_error) |
1013 | return gh->gh_error; | |
1014 | ||
1015 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
85d1da67 | 1016 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, |
b3b94faa DT |
1017 | gh->gh_flags)); |
1018 | ||
1019 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
1020 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1021 | ||
1022 | if (glops->go_lock) { | |
1023 | gh->gh_error = glops->go_lock(gh); | |
1024 | if (gh->gh_error) { | |
1025 | spin_lock(&gl->gl_spin); | |
1026 | list_del_init(&gh->gh_list); | |
b3b94faa DT |
1027 | spin_unlock(&gl->gl_spin); |
1028 | } | |
1029 | } | |
1030 | ||
1031 | spin_lock(&gl->gl_spin); | |
1032 | gl->gl_req_gh = NULL; | |
1033 | gl->gl_req_bh = NULL; | |
1034 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
1035 | run_queue(gl); |
1036 | spin_unlock(&gl->gl_spin); | |
1037 | } | |
1038 | ||
1039 | return gh->gh_error; | |
1040 | } | |
1041 | ||
1042 | static inline struct gfs2_holder * | |
04b933f2 | 1043 | find_holder_by_owner(struct list_head *head, pid_t pid) |
b3b94faa DT |
1044 | { |
1045 | struct gfs2_holder *gh; | |
1046 | ||
1047 | list_for_each_entry(gh, head, gh_list) { | |
04b933f2 | 1048 | if (gh->gh_owner_pid == pid) |
b3b94faa DT |
1049 | return gh; |
1050 | } | |
1051 | ||
1052 | return NULL; | |
1053 | } | |
1054 | ||
7c52b166 RP |
1055 | static void print_dbg(struct glock_iter *gi, const char *fmt, ...) |
1056 | { | |
1057 | va_list args; | |
1058 | ||
1059 | va_start(args, fmt); | |
1060 | if (gi) { | |
1061 | vsprintf(gi->string, fmt, args); | |
1062 | seq_printf(gi->seq, gi->string); | |
1063 | } | |
1064 | else | |
1065 | vprintk(fmt, args); | |
1066 | va_end(args); | |
1067 | } | |
1068 | ||
b3b94faa DT |
1069 | /** |
1070 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1071 | * @gh: the holder structure to add | |
1072 | * | |
1073 | */ | |
1074 | ||
1075 | static void add_to_queue(struct gfs2_holder *gh) | |
1076 | { | |
1077 | struct gfs2_glock *gl = gh->gh_gl; | |
1078 | struct gfs2_holder *existing; | |
1079 | ||
04b933f2 | 1080 | BUG_ON(!gh->gh_owner_pid); |
fee852e3 SW |
1081 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
1082 | BUG(); | |
190562bd | 1083 | |
04b933f2 | 1084 | existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner_pid); |
b3b94faa | 1085 | if (existing) { |
5965b1f4 | 1086 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
04b933f2 | 1087 | printk(KERN_INFO "pid : %d\n", existing->gh_owner_pid); |
907b9bce | 1088 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1089 | existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state); |
5965b1f4 | 1090 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); |
04b933f2 | 1091 | printk(KERN_INFO "pid : %d\n", gh->gh_owner_pid); |
907b9bce | 1092 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1093 | gl->gl_name.ln_type, gl->gl_state); |
5965b1f4 | 1094 | BUG(); |
b3b94faa DT |
1095 | } |
1096 | ||
04b933f2 | 1097 | existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner_pid); |
b3b94faa | 1098 | if (existing) { |
5965b1f4 SW |
1099 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
1100 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1101 | BUG(); | |
b3b94faa DT |
1102 | } |
1103 | ||
b3b94faa DT |
1104 | if (gh->gh_flags & LM_FLAG_PRIORITY) |
1105 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1106 | else | |
907b9bce | 1107 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); |
b3b94faa DT |
1108 | } |
1109 | ||
1110 | /** | |
1111 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1112 | * @gh: the holder structure | |
1113 | * | |
1114 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1115 | * | |
1116 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1117 | */ | |
1118 | ||
1119 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1120 | { | |
1121 | struct gfs2_glock *gl = gh->gh_gl; | |
1122 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1123 | int error = 0; | |
1124 | ||
320dd101 | 1125 | restart: |
b3b94faa DT |
1126 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
1127 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1128 | return -EIO; | |
1129 | } | |
1130 | ||
1131 | set_bit(HIF_PROMOTE, &gh->gh_iflags); | |
1132 | ||
1133 | spin_lock(&gl->gl_spin); | |
1134 | add_to_queue(gh); | |
1135 | run_queue(gl); | |
1136 | spin_unlock(&gl->gl_spin); | |
1137 | ||
1138 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1139 | error = glock_wait_internal(gh); | |
1140 | if (error == GLR_CANCELED) { | |
190562bd | 1141 | msleep(100); |
b3b94faa DT |
1142 | goto restart; |
1143 | } | |
1144 | } | |
1145 | ||
b3b94faa DT |
1146 | return error; |
1147 | } | |
1148 | ||
1149 | /** | |
1150 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1151 | * @gh: the holder | |
1152 | * | |
1153 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1154 | */ | |
1155 | ||
1156 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1157 | { | |
1158 | struct gfs2_glock *gl = gh->gh_gl; | |
1159 | int ready = 0; | |
1160 | ||
1161 | spin_lock(&gl->gl_spin); | |
1162 | ||
1163 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1164 | ready = 1; | |
1165 | else if (list_empty(&gh->gh_list)) { | |
1166 | if (gh->gh_error == GLR_CANCELED) { | |
1167 | spin_unlock(&gl->gl_spin); | |
190562bd | 1168 | msleep(100); |
b3b94faa DT |
1169 | if (gfs2_glock_nq(gh)) |
1170 | return 1; | |
1171 | return 0; | |
1172 | } else | |
1173 | ready = 1; | |
1174 | } | |
1175 | ||
1176 | spin_unlock(&gl->gl_spin); | |
1177 | ||
1178 | return ready; | |
1179 | } | |
1180 | ||
1181 | /** | |
1182 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1183 | * @gh: the holder structure | |
1184 | * | |
1185 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1186 | */ | |
1187 | ||
1188 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1189 | { | |
1190 | int error; | |
1191 | ||
1192 | error = glock_wait_internal(gh); | |
1193 | if (error == GLR_CANCELED) { | |
190562bd | 1194 | msleep(100); |
b3b94faa DT |
1195 | gh->gh_flags &= ~GL_ASYNC; |
1196 | error = gfs2_glock_nq(gh); | |
1197 | } | |
1198 | ||
1199 | return error; | |
1200 | } | |
1201 | ||
1202 | /** | |
1203 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1204 | * @gh: the glock holder | |
1205 | * | |
1206 | */ | |
1207 | ||
1208 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1209 | { | |
1210 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1211 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa | 1212 | |
b3b94faa | 1213 | if (gh->gh_flags & GL_NOCACHE) |
d93cfa98 | 1214 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa DT |
1215 | |
1216 | gfs2_glmutex_lock(gl); | |
1217 | ||
1218 | spin_lock(&gl->gl_spin); | |
1219 | list_del_init(&gh->gh_list); | |
1220 | ||
1221 | if (list_empty(&gl->gl_holders)) { | |
1222 | spin_unlock(&gl->gl_spin); | |
1223 | ||
1224 | if (glops->go_unlock) | |
1225 | glops->go_unlock(gh); | |
1226 | ||
b3b94faa | 1227 | spin_lock(&gl->gl_spin); |
3b8249f6 | 1228 | gl->gl_stamp = jiffies; |
b3b94faa DT |
1229 | } |
1230 | ||
1231 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1232 | run_queue(gl); | |
1233 | spin_unlock(&gl->gl_spin); | |
1234 | } | |
1235 | ||
d93cfa98 AD |
1236 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1237 | { | |
1238 | struct gfs2_glock *gl = gh->gh_gl; | |
1239 | gfs2_glock_dq(gh); | |
1240 | wait_on_demote(gl); | |
1241 | } | |
1242 | ||
b3b94faa DT |
1243 | /** |
1244 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1245 | * @gh: the holder structure | |
1246 | * | |
1247 | */ | |
1248 | ||
1249 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1250 | { | |
1251 | gfs2_glock_dq(gh); | |
1252 | gfs2_holder_uninit(gh); | |
1253 | } | |
1254 | ||
1255 | /** | |
1256 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1257 | * @sdp: the filesystem | |
1258 | * @number: the lock number | |
1259 | * @glops: the glock operations for the type of glock | |
1260 | * @state: the state to acquire the glock in | |
1261 | * @flags: modifier flags for the aquisition | |
1262 | * @gh: the struct gfs2_holder | |
1263 | * | |
1264 | * Returns: errno | |
1265 | */ | |
1266 | ||
cd915493 | 1267 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1268 | const struct gfs2_glock_operations *glops, |
1269 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1270 | { |
1271 | struct gfs2_glock *gl; | |
1272 | int error; | |
1273 | ||
1274 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1275 | if (!error) { | |
1276 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1277 | gfs2_glock_put(gl); | |
1278 | } | |
1279 | ||
1280 | return error; | |
1281 | } | |
1282 | ||
1283 | /** | |
1284 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1285 | * @arg_a: the first structure | |
1286 | * @arg_b: the second structure | |
1287 | * | |
1288 | */ | |
1289 | ||
1290 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1291 | { | |
a5e08a9e SW |
1292 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1293 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1294 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1295 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1296 | |
1297 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1298 | return 1; |
1299 | if (a->ln_number < b->ln_number) | |
1300 | return -1; | |
1c0f4872 | 1301 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1302 | return 0; |
b3b94faa DT |
1303 | } |
1304 | ||
1305 | /** | |
1306 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1307 | * @num_gh: the number of structures | |
1308 | * @ghs: an array of struct gfs2_holder structures | |
1309 | * | |
1310 | * Returns: 0 on success (all glocks acquired), | |
1311 | * errno on failure (no glocks acquired) | |
1312 | */ | |
1313 | ||
1314 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1315 | struct gfs2_holder **p) | |
1316 | { | |
1317 | unsigned int x; | |
1318 | int error = 0; | |
1319 | ||
1320 | for (x = 0; x < num_gh; x++) | |
1321 | p[x] = &ghs[x]; | |
1322 | ||
1323 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1324 | ||
1325 | for (x = 0; x < num_gh; x++) { | |
1326 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1327 | ||
1328 | error = gfs2_glock_nq(p[x]); | |
1329 | if (error) { | |
1330 | while (x--) | |
1331 | gfs2_glock_dq(p[x]); | |
1332 | break; | |
1333 | } | |
1334 | } | |
1335 | ||
1336 | return error; | |
1337 | } | |
1338 | ||
1339 | /** | |
1340 | * gfs2_glock_nq_m - acquire multiple glocks | |
1341 | * @num_gh: the number of structures | |
1342 | * @ghs: an array of struct gfs2_holder structures | |
1343 | * | |
b3b94faa DT |
1344 | * |
1345 | * Returns: 0 on success (all glocks acquired), | |
1346 | * errno on failure (no glocks acquired) | |
1347 | */ | |
1348 | ||
1349 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1350 | { | |
eaf5bd3c SW |
1351 | struct gfs2_holder *tmp[4]; |
1352 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1353 | int error = 0; |
1354 | ||
eaf5bd3c SW |
1355 | switch(num_gh) { |
1356 | case 0: | |
b3b94faa | 1357 | return 0; |
eaf5bd3c | 1358 | case 1: |
b3b94faa DT |
1359 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1360 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1361 | default: |
1362 | if (num_gh <= 4) | |
b3b94faa | 1363 | break; |
eaf5bd3c SW |
1364 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1365 | if (!pph) | |
1366 | return -ENOMEM; | |
b3b94faa DT |
1367 | } |
1368 | ||
eaf5bd3c | 1369 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1370 | |
eaf5bd3c SW |
1371 | if (pph != tmp) |
1372 | kfree(pph); | |
b3b94faa DT |
1373 | |
1374 | return error; | |
1375 | } | |
1376 | ||
1377 | /** | |
1378 | * gfs2_glock_dq_m - release multiple glocks | |
1379 | * @num_gh: the number of structures | |
1380 | * @ghs: an array of struct gfs2_holder structures | |
1381 | * | |
1382 | */ | |
1383 | ||
1384 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1385 | { | |
1386 | unsigned int x; | |
1387 | ||
1388 | for (x = 0; x < num_gh; x++) | |
1389 | gfs2_glock_dq(&ghs[x]); | |
1390 | } | |
1391 | ||
1392 | /** | |
1393 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1394 | * @num_gh: the number of structures | |
1395 | * @ghs: an array of struct gfs2_holder structures | |
1396 | * | |
1397 | */ | |
1398 | ||
1399 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1400 | { | |
1401 | unsigned int x; | |
1402 | ||
1403 | for (x = 0; x < num_gh; x++) | |
1404 | gfs2_glock_dq_uninit(&ghs[x]); | |
1405 | } | |
1406 | ||
b3b94faa DT |
1407 | /** |
1408 | * gfs2_lvb_hold - attach a LVB from a glock | |
1409 | * @gl: The glock in question | |
1410 | * | |
1411 | */ | |
1412 | ||
1413 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1414 | { | |
1415 | int error; | |
1416 | ||
1417 | gfs2_glmutex_lock(gl); | |
1418 | ||
1419 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1420 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1421 | if (error) { | |
1422 | gfs2_glmutex_unlock(gl); | |
1423 | return error; | |
1424 | } | |
1425 | gfs2_glock_hold(gl); | |
1426 | } | |
1427 | atomic_inc(&gl->gl_lvb_count); | |
1428 | ||
1429 | gfs2_glmutex_unlock(gl); | |
1430 | ||
1431 | return 0; | |
1432 | } | |
1433 | ||
1434 | /** | |
1435 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1436 | * @gl: The glock in question | |
1437 | * | |
1438 | */ | |
1439 | ||
1440 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1441 | { | |
1442 | gfs2_glock_hold(gl); | |
1443 | gfs2_glmutex_lock(gl); | |
1444 | ||
1445 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1446 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1447 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1448 | gl->gl_lvb = NULL; | |
1449 | gfs2_glock_put(gl); | |
1450 | } | |
1451 | ||
1452 | gfs2_glmutex_unlock(gl); | |
1453 | gfs2_glock_put(gl); | |
1454 | } | |
1455 | ||
b3b94faa DT |
1456 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1457 | unsigned int state) | |
1458 | { | |
1459 | struct gfs2_glock *gl; | |
1460 | ||
1461 | gl = gfs2_glock_find(sdp, name); | |
1462 | if (!gl) | |
1463 | return; | |
1464 | ||
d93cfa98 | 1465 | handle_callback(gl, state, 1); |
b3b94faa DT |
1466 | |
1467 | spin_lock(&gl->gl_spin); | |
1468 | run_queue(gl); | |
1469 | spin_unlock(&gl->gl_spin); | |
1470 | ||
1471 | gfs2_glock_put(gl); | |
1472 | } | |
1473 | ||
1474 | /** | |
1475 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1476 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1477 | * @type: Type of callback |
1478 | * @data: Type dependent data pointer | |
1479 | * | |
1480 | * Called by the locking module when it wants to tell us something. | |
1481 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1482 | * a journal from another client needs to be recovered. | |
1483 | */ | |
1484 | ||
9b47c11d | 1485 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1486 | { |
9b47c11d | 1487 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1488 | |
b3b94faa DT |
1489 | switch (type) { |
1490 | case LM_CB_NEED_E: | |
e7f5c01c | 1491 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1492 | return; |
1493 | ||
1494 | case LM_CB_NEED_D: | |
e7f5c01c | 1495 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1496 | return; |
1497 | ||
1498 | case LM_CB_NEED_S: | |
e7f5c01c | 1499 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1500 | return; |
1501 | ||
1502 | case LM_CB_ASYNC: { | |
e7f5c01c | 1503 | struct lm_async_cb *async = data; |
b3b94faa DT |
1504 | struct gfs2_glock *gl; |
1505 | ||
61be084e | 1506 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1507 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1508 | if (gfs2_assert_warn(sdp, gl)) | |
1509 | return; | |
1510 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1511 | gl->gl_req_bh(gl, async->lc_ret); | |
1512 | gfs2_glock_put(gl); | |
61be084e | 1513 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1514 | return; |
1515 | } | |
1516 | ||
1517 | case LM_CB_NEED_RECOVERY: | |
1518 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1519 | if (sdp->sd_recoverd_process) | |
1520 | wake_up_process(sdp->sd_recoverd_process); | |
1521 | return; | |
1522 | ||
1523 | case LM_CB_DROPLOCKS: | |
1524 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1525 | gfs2_quota_scan(sdp); | |
1526 | return; | |
1527 | ||
1528 | default: | |
1529 | gfs2_assert_warn(sdp, 0); | |
1530 | return; | |
1531 | } | |
1532 | } | |
1533 | ||
b3b94faa DT |
1534 | /** |
1535 | * demote_ok - Check to see if it's ok to unlock a glock | |
1536 | * @gl: the glock | |
1537 | * | |
1538 | * Returns: 1 if it's ok | |
1539 | */ | |
1540 | ||
1541 | static int demote_ok(struct gfs2_glock *gl) | |
1542 | { | |
8fb4b536 | 1543 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1544 | int demote = 1; |
1545 | ||
1546 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1547 | demote = 0; | |
b3b94faa DT |
1548 | else if (glops->go_demote_ok) |
1549 | demote = glops->go_demote_ok(gl); | |
1550 | ||
1551 | return demote; | |
1552 | } | |
1553 | ||
1554 | /** | |
1555 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1556 | * @gl: the glock | |
1557 | * | |
1558 | */ | |
1559 | ||
1560 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1561 | { | |
1562 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1563 | ||
1564 | spin_lock(&sdp->sd_reclaim_lock); | |
1565 | if (list_empty(&gl->gl_reclaim)) { | |
1566 | gfs2_glock_hold(gl); | |
1567 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1568 | atomic_inc(&sdp->sd_reclaim_count); | |
1569 | } | |
1570 | spin_unlock(&sdp->sd_reclaim_lock); | |
1571 | ||
1572 | wake_up(&sdp->sd_reclaim_wq); | |
1573 | } | |
1574 | ||
1575 | /** | |
1576 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1577 | * @sdp: the filesystem | |
1578 | * | |
1579 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1580 | * different glock and we notice that there are a lot of glocks in the | |
1581 | * reclaim list. | |
1582 | * | |
1583 | */ | |
1584 | ||
1585 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1586 | { | |
1587 | struct gfs2_glock *gl; | |
1588 | ||
1589 | spin_lock(&sdp->sd_reclaim_lock); | |
1590 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1591 | spin_unlock(&sdp->sd_reclaim_lock); | |
1592 | return; | |
1593 | } | |
1594 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1595 | struct gfs2_glock, gl_reclaim); | |
1596 | list_del_init(&gl->gl_reclaim); | |
1597 | spin_unlock(&sdp->sd_reclaim_lock); | |
1598 | ||
1599 | atomic_dec(&sdp->sd_reclaim_count); | |
1600 | atomic_inc(&sdp->sd_reclaimed); | |
1601 | ||
1602 | if (gfs2_glmutex_trylock(gl)) { | |
12132933 | 1603 | if (list_empty(&gl->gl_holders) && |
50299965 | 1604 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
d93cfa98 | 1605 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa DT |
1606 | gfs2_glmutex_unlock(gl); |
1607 | } | |
1608 | ||
1609 | gfs2_glock_put(gl); | |
1610 | } | |
1611 | ||
1612 | /** | |
1613 | * examine_bucket - Call a function for glock in a hash bucket | |
1614 | * @examiner: the function | |
1615 | * @sdp: the filesystem | |
1616 | * @bucket: the bucket | |
1617 | * | |
1618 | * Returns: 1 if the bucket has entries | |
1619 | */ | |
1620 | ||
1621 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1622 | unsigned int hash) |
b3b94faa | 1623 | { |
24264434 SW |
1624 | struct gfs2_glock *gl, *prev = NULL; |
1625 | int has_entries = 0; | |
b6397893 | 1626 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1627 | |
24264434 | 1628 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1629 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1630 | if (hlist_empty(head)) | |
24264434 | 1631 | goto out; |
b6397893 SW |
1632 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1633 | while(1) { | |
8fbbfd21 | 1634 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1635 | gfs2_glock_hold(gl); |
24264434 SW |
1636 | read_unlock(gl_lock_addr(hash)); |
1637 | if (prev) | |
1638 | gfs2_glock_put(prev); | |
1639 | prev = gl; | |
1640 | examiner(gl); | |
a8336344 | 1641 | has_entries = 1; |
24264434 | 1642 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1643 | } |
b6397893 SW |
1644 | if (gl->gl_list.next == NULL) |
1645 | break; | |
24264434 | 1646 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1647 | } |
24264434 SW |
1648 | out: |
1649 | read_unlock(gl_lock_addr(hash)); | |
1650 | if (prev) | |
1651 | gfs2_glock_put(prev); | |
8fbbfd21 | 1652 | cond_resched(); |
24264434 | 1653 | return has_entries; |
b3b94faa DT |
1654 | } |
1655 | ||
1656 | /** | |
1657 | * scan_glock - look at a glock and see if we can reclaim it | |
1658 | * @gl: the glock to look at | |
1659 | * | |
1660 | */ | |
1661 | ||
1662 | static void scan_glock(struct gfs2_glock *gl) | |
1663 | { | |
b004157a | 1664 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1665 | return; |
a2242db0 | 1666 | |
b3b94faa | 1667 | if (gfs2_glmutex_trylock(gl)) { |
12132933 | 1668 | if (list_empty(&gl->gl_holders) && |
24264434 | 1669 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa | 1670 | goto out_schedule; |
b3b94faa DT |
1671 | gfs2_glmutex_unlock(gl); |
1672 | } | |
b3b94faa DT |
1673 | return; |
1674 | ||
627add2d | 1675 | out_schedule: |
b3b94faa DT |
1676 | gfs2_glmutex_unlock(gl); |
1677 | gfs2_glock_schedule_for_reclaim(gl); | |
b3b94faa DT |
1678 | } |
1679 | ||
b3b94faa DT |
1680 | /** |
1681 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1682 | * @gl: the glock to look at | |
1683 | * | |
1684 | */ | |
1685 | ||
1686 | static void clear_glock(struct gfs2_glock *gl) | |
1687 | { | |
1688 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1689 | int released; | |
1690 | ||
1691 | spin_lock(&sdp->sd_reclaim_lock); | |
1692 | if (!list_empty(&gl->gl_reclaim)) { | |
1693 | list_del_init(&gl->gl_reclaim); | |
1694 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1695 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1696 | released = gfs2_glock_put(gl); |
1697 | gfs2_assert(sdp, !released); | |
190562bd SW |
1698 | } else { |
1699 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1700 | } |
b3b94faa DT |
1701 | |
1702 | if (gfs2_glmutex_trylock(gl)) { | |
90101c31 | 1703 | if (list_empty(&gl->gl_holders) && |
b3b94faa | 1704 | gl->gl_state != LM_ST_UNLOCKED) |
d93cfa98 | 1705 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa DT |
1706 | gfs2_glmutex_unlock(gl); |
1707 | } | |
b3b94faa DT |
1708 | } |
1709 | ||
1710 | /** | |
1711 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1712 | * @sdp: the filesystem | |
1713 | * @wait: wait until it's all gone | |
1714 | * | |
1715 | * Called when unmounting the filesystem, or when inter-node lock manager | |
1716 | * requests DROPLOCKS because it is running out of capacity. | |
1717 | */ | |
1718 | ||
1719 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
1720 | { | |
1721 | unsigned long t; | |
1722 | unsigned int x; | |
1723 | int cont; | |
1724 | ||
1725 | t = jiffies; | |
1726 | ||
1727 | for (;;) { | |
1728 | cont = 0; | |
24264434 | 1729 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1730 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1731 | cont = 1; |
24264434 | 1732 | } |
b3b94faa DT |
1733 | |
1734 | if (!wait || !cont) | |
1735 | break; | |
1736 | ||
1737 | if (time_after_eq(jiffies, | |
1738 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1739 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1740 | "Dumping lock state...\n"); | |
1741 | gfs2_dump_lockstate(sdp); | |
1742 | t = jiffies; | |
1743 | } | |
1744 | ||
61be084e | 1745 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1746 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1747 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1748 | msleep(10); |
b3b94faa DT |
1749 | } |
1750 | } | |
1751 | ||
1752 | /* | |
1753 | * Diagnostic routines to help debug distributed deadlock | |
1754 | */ | |
1755 | ||
04b933f2 RP |
1756 | static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt, |
1757 | unsigned long address) | |
1758 | { | |
7a0079d9 | 1759 | char buffer[KSYM_SYMBOL_LEN]; |
04b933f2 | 1760 | |
7a0079d9 RP |
1761 | sprint_symbol(buffer, address); |
1762 | print_dbg(gi, fmt, buffer); | |
04b933f2 RP |
1763 | } |
1764 | ||
b3b94faa DT |
1765 | /** |
1766 | * dump_holder - print information about a glock holder | |
1767 | * @str: a string naming the type of holder | |
1768 | * @gh: the glock holder | |
1769 | * | |
1770 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1771 | */ | |
1772 | ||
7c52b166 RP |
1773 | static int dump_holder(struct glock_iter *gi, char *str, |
1774 | struct gfs2_holder *gh) | |
b3b94faa DT |
1775 | { |
1776 | unsigned int x; | |
04b933f2 | 1777 | struct task_struct *gh_owner; |
b3b94faa | 1778 | |
7c52b166 | 1779 | print_dbg(gi, " %s\n", str); |
04b933f2 RP |
1780 | if (gh->gh_owner_pid) { |
1781 | print_dbg(gi, " owner = %ld ", (long)gh->gh_owner_pid); | |
1782 | gh_owner = find_task_by_pid(gh->gh_owner_pid); | |
1783 | if (gh_owner) | |
1784 | print_dbg(gi, "(%s)\n", gh_owner->comm); | |
1785 | else | |
1786 | print_dbg(gi, "(ended)\n"); | |
1787 | } else | |
1788 | print_dbg(gi, " owner = -1\n"); | |
7c52b166 RP |
1789 | print_dbg(gi, " gh_state = %u\n", gh->gh_state); |
1790 | print_dbg(gi, " gh_flags ="); | |
b3b94faa DT |
1791 | for (x = 0; x < 32; x++) |
1792 | if (gh->gh_flags & (1 << x)) | |
7c52b166 RP |
1793 | print_dbg(gi, " %u", x); |
1794 | print_dbg(gi, " \n"); | |
1795 | print_dbg(gi, " error = %d\n", gh->gh_error); | |
1796 | print_dbg(gi, " gh_iflags ="); | |
b3b94faa DT |
1797 | for (x = 0; x < 32; x++) |
1798 | if (test_bit(x, &gh->gh_iflags)) | |
7c52b166 RP |
1799 | print_dbg(gi, " %u", x); |
1800 | print_dbg(gi, " \n"); | |
04b933f2 | 1801 | gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip); |
b3b94faa | 1802 | |
7c52b166 | 1803 | return 0; |
b3b94faa DT |
1804 | } |
1805 | ||
1806 | /** | |
1807 | * dump_inode - print information about an inode | |
1808 | * @ip: the inode | |
1809 | * | |
1810 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1811 | */ | |
1812 | ||
7c52b166 | 1813 | static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip) |
b3b94faa DT |
1814 | { |
1815 | unsigned int x; | |
b3b94faa | 1816 | |
7c52b166 RP |
1817 | print_dbg(gi, " Inode:\n"); |
1818 | print_dbg(gi, " num = %llu/%llu\n", | |
dbb7cae2 SW |
1819 | (unsigned long long)ip->i_no_formal_ino, |
1820 | (unsigned long long)ip->i_no_addr); | |
7c52b166 RP |
1821 | print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode)); |
1822 | print_dbg(gi, " i_flags ="); | |
b3b94faa DT |
1823 | for (x = 0; x < 32; x++) |
1824 | if (test_bit(x, &ip->i_flags)) | |
7c52b166 RP |
1825 | print_dbg(gi, " %u", x); |
1826 | print_dbg(gi, " \n"); | |
1827 | return 0; | |
b3b94faa DT |
1828 | } |
1829 | ||
1830 | /** | |
1831 | * dump_glock - print information about a glock | |
1832 | * @gl: the glock | |
1833 | * @count: where we are in the buffer | |
1834 | * | |
1835 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1836 | */ | |
1837 | ||
7c52b166 | 1838 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl) |
b3b94faa DT |
1839 | { |
1840 | struct gfs2_holder *gh; | |
1841 | unsigned int x; | |
1842 | int error = -ENOBUFS; | |
04b933f2 | 1843 | struct task_struct *gl_owner; |
b3b94faa DT |
1844 | |
1845 | spin_lock(&gl->gl_spin); | |
1846 | ||
a947e033 | 1847 | print_dbg(gi, "Glock 0x%p (%u, 0x%llx)\n", gl, gl->gl_name.ln_type, |
7c52b166 RP |
1848 | (unsigned long long)gl->gl_name.ln_number); |
1849 | print_dbg(gi, " gl_flags ="); | |
85d1da67 | 1850 | for (x = 0; x < 32; x++) { |
b3b94faa | 1851 | if (test_bit(x, &gl->gl_flags)) |
7c52b166 RP |
1852 | print_dbg(gi, " %u", x); |
1853 | } | |
04b933f2 RP |
1854 | if (!test_bit(GLF_LOCK, &gl->gl_flags)) |
1855 | print_dbg(gi, " (unlocked)"); | |
7c52b166 RP |
1856 | print_dbg(gi, " \n"); |
1857 | print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref)); | |
1858 | print_dbg(gi, " gl_state = %u\n", gl->gl_state); | |
04b933f2 RP |
1859 | if (gl->gl_owner_pid) { |
1860 | gl_owner = find_task_by_pid(gl->gl_owner_pid); | |
1861 | if (gl_owner) | |
1862 | print_dbg(gi, " gl_owner = pid %d (%s)\n", | |
1863 | gl->gl_owner_pid, gl_owner->comm); | |
1864 | else | |
1865 | print_dbg(gi, " gl_owner = %d (ended)\n", | |
1866 | gl->gl_owner_pid); | |
1867 | } else | |
1868 | print_dbg(gi, " gl_owner = -1\n"); | |
7c52b166 RP |
1869 | print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip); |
1870 | print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); | |
1871 | print_dbg(gi, " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
1872 | print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
1873 | print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
1874 | print_dbg(gi, " le = %s\n", | |
b3b94faa | 1875 | (list_empty(&gl->gl_le.le_list)) ? "no" : "yes"); |
7c52b166 RP |
1876 | print_dbg(gi, " reclaim = %s\n", |
1877 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); | |
b3b94faa | 1878 | if (gl->gl_aspace) |
7c52b166 RP |
1879 | print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, |
1880 | gl->gl_aspace->i_mapping->nrpages); | |
b3b94faa | 1881 | else |
7c52b166 RP |
1882 | print_dbg(gi, " aspace = no\n"); |
1883 | print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa | 1884 | if (gl->gl_req_gh) { |
7c52b166 | 1885 | error = dump_holder(gi, "Request", gl->gl_req_gh); |
b3b94faa DT |
1886 | if (error) |
1887 | goto out; | |
1888 | } | |
1889 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
7c52b166 | 1890 | error = dump_holder(gi, "Holder", gh); |
b3b94faa DT |
1891 | if (error) |
1892 | goto out; | |
1893 | } | |
1894 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
7c52b166 | 1895 | error = dump_holder(gi, "Waiter1", gh); |
b3b94faa DT |
1896 | if (error) |
1897 | goto out; | |
1898 | } | |
b3b94faa | 1899 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { |
7c52b166 | 1900 | error = dump_holder(gi, "Waiter3", gh); |
b3b94faa DT |
1901 | if (error) |
1902 | goto out; | |
1903 | } | |
3b8249f6 SW |
1904 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
1905 | print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n", | |
cd81a4ba RP |
1906 | gl->gl_demote_state, (unsigned long long) |
1907 | (jiffies - gl->gl_demote_time)*(1000000/HZ)); | |
3b8249f6 | 1908 | } |
5c676f6d | 1909 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa | 1910 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
7c52b166 RP |
1911 | list_empty(&gl->gl_holders)) { |
1912 | error = dump_inode(gi, gl->gl_object); | |
b3b94faa DT |
1913 | if (error) |
1914 | goto out; | |
1915 | } else { | |
1916 | error = -ENOBUFS; | |
7c52b166 | 1917 | print_dbg(gi, " Inode: busy\n"); |
b3b94faa DT |
1918 | } |
1919 | } | |
1920 | ||
1921 | error = 0; | |
1922 | ||
a91ea69f | 1923 | out: |
b3b94faa | 1924 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
1925 | return error; |
1926 | } | |
1927 | ||
1928 | /** | |
1929 | * gfs2_dump_lockstate - print out the current lockstate | |
1930 | * @sdp: the filesystem | |
1931 | * @ub: the buffer to copy the information into | |
1932 | * | |
1933 | * If @ub is NULL, dump the lockstate to the console. | |
1934 | * | |
1935 | */ | |
1936 | ||
08bc2dbc | 1937 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1938 | { |
b3b94faa | 1939 | struct gfs2_glock *gl; |
b6397893 | 1940 | struct hlist_node *h; |
b3b94faa DT |
1941 | unsigned int x; |
1942 | int error = 0; | |
1943 | ||
1944 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1945 | |
087efdd3 | 1946 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1947 | |
b6397893 | 1948 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1949 | if (gl->gl_sbd != sdp) |
1950 | continue; | |
b3b94faa | 1951 | |
7c52b166 | 1952 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1953 | if (error) |
1954 | break; | |
1955 | } | |
1956 | ||
087efdd3 | 1957 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1958 | |
1959 | if (error) | |
1960 | break; | |
1961 | } | |
1962 | ||
1963 | ||
1964 | return error; | |
1965 | } | |
1966 | ||
8fbbfd21 SW |
1967 | /** |
1968 | * gfs2_scand - Look for cached glocks and inodes to toss from memory | |
1969 | * @sdp: Pointer to GFS2 superblock | |
1970 | * | |
1971 | * One of these daemons runs, finding candidates to add to sd_reclaim_list. | |
1972 | * See gfs2_glockd() | |
1973 | */ | |
1974 | ||
1975 | static int gfs2_scand(void *data) | |
1976 | { | |
1977 | unsigned x; | |
1978 | unsigned delay; | |
1979 | ||
1980 | while (!kthread_should_stop()) { | |
1981 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1982 | examine_bucket(scan_glock, NULL, x); | |
1983 | if (freezing(current)) | |
1984 | refrigerator(); | |
1985 | delay = scand_secs; | |
1986 | if (delay < 1) | |
1987 | delay = 1; | |
1988 | schedule_timeout_interruptible(delay * HZ); | |
1989 | } | |
1990 | ||
1991 | return 0; | |
1992 | } | |
1993 | ||
1994 | ||
1995 | ||
85d1da67 SW |
1996 | int __init gfs2_glock_init(void) |
1997 | { | |
1998 | unsigned i; | |
1999 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 2000 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 2001 | } |
087efdd3 SW |
2002 | #ifdef GL_HASH_LOCK_SZ |
2003 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
2004 | rwlock_init(&gl_hash_locks[i]); | |
2005 | } | |
2006 | #endif | |
8fbbfd21 SW |
2007 | |
2008 | scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand"); | |
2009 | if (IS_ERR(scand_process)) | |
2010 | return PTR_ERR(scand_process); | |
2011 | ||
85d1da67 SW |
2012 | return 0; |
2013 | } | |
2014 | ||
8fbbfd21 SW |
2015 | void gfs2_glock_exit(void) |
2016 | { | |
2017 | kthread_stop(scand_process); | |
2018 | } | |
2019 | ||
2020 | module_param(scand_secs, uint, S_IRUGO|S_IWUSR); | |
2021 | MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs"); | |
2022 | ||
7c52b166 RP |
2023 | static int gfs2_glock_iter_next(struct glock_iter *gi) |
2024 | { | |
7b08fc62 SW |
2025 | struct gfs2_glock *gl; |
2026 | ||
a947e033 | 2027 | restart: |
7a0079d9 | 2028 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
2029 | gl = gi->gl; |
2030 | if (gl) { | |
a947e033 AD |
2031 | gi->gl = hlist_entry(gl->gl_list.next, |
2032 | struct gfs2_glock, gl_list); | |
7c52b166 | 2033 | if (gi->gl) |
7b08fc62 | 2034 | gfs2_glock_hold(gi->gl); |
7c52b166 | 2035 | } |
7a0079d9 | 2036 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
2037 | if (gl) |
2038 | gfs2_glock_put(gl); | |
a947e033 | 2039 | if (gl && gi->gl == NULL) |
7b08fc62 | 2040 | gi->hash++; |
a947e033 | 2041 | while(gi->gl == NULL) { |
7b08fc62 SW |
2042 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
2043 | return 1; | |
2044 | read_lock(gl_lock_addr(gi->hash)); | |
2045 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
2046 | struct gfs2_glock, gl_list); | |
2047 | if (gi->gl) | |
2048 | gfs2_glock_hold(gi->gl); | |
2049 | read_unlock(gl_lock_addr(gi->hash)); | |
a947e033 | 2050 | gi->hash++; |
7b08fc62 | 2051 | } |
a947e033 AD |
2052 | |
2053 | if (gi->sdp != gi->gl->gl_sbd) | |
2054 | goto restart; | |
2055 | ||
7c52b166 RP |
2056 | return 0; |
2057 | } | |
2058 | ||
2059 | static void gfs2_glock_iter_free(struct glock_iter *gi) | |
2060 | { | |
7b08fc62 SW |
2061 | if (gi->gl) |
2062 | gfs2_glock_put(gi->gl); | |
7c52b166 RP |
2063 | kfree(gi); |
2064 | } | |
2065 | ||
2066 | static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp) | |
2067 | { | |
2068 | struct glock_iter *gi; | |
2069 | ||
2070 | gi = kmalloc(sizeof (*gi), GFP_KERNEL); | |
2071 | if (!gi) | |
2072 | return NULL; | |
2073 | ||
2074 | gi->sdp = sdp; | |
2075 | gi->hash = 0; | |
7c52b166 | 2076 | gi->seq = NULL; |
a947e033 | 2077 | gi->gl = NULL; |
7c52b166 RP |
2078 | memset(gi->string, 0, sizeof(gi->string)); |
2079 | ||
a947e033 | 2080 | if (gfs2_glock_iter_next(gi)) { |
7c52b166 RP |
2081 | gfs2_glock_iter_free(gi); |
2082 | return NULL; | |
2083 | } | |
2084 | ||
2085 | return gi; | |
2086 | } | |
2087 | ||
2088 | static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos) | |
2089 | { | |
2090 | struct glock_iter *gi; | |
2091 | loff_t n = *pos; | |
2092 | ||
2093 | gi = gfs2_glock_iter_init(file->private); | |
2094 | if (!gi) | |
2095 | return NULL; | |
2096 | ||
7b08fc62 | 2097 | while(n--) { |
7c52b166 RP |
2098 | if (gfs2_glock_iter_next(gi)) { |
2099 | gfs2_glock_iter_free(gi); | |
2100 | return NULL; | |
2101 | } | |
2102 | } | |
2103 | ||
2104 | return gi; | |
2105 | } | |
2106 | ||
2107 | static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr, | |
2108 | loff_t *pos) | |
2109 | { | |
2110 | struct glock_iter *gi = iter_ptr; | |
2111 | ||
2112 | (*pos)++; | |
2113 | ||
2114 | if (gfs2_glock_iter_next(gi)) { | |
2115 | gfs2_glock_iter_free(gi); | |
2116 | return NULL; | |
2117 | } | |
2118 | ||
2119 | return gi; | |
2120 | } | |
2121 | ||
2122 | static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr) | |
2123 | { | |
7b08fc62 SW |
2124 | struct glock_iter *gi = iter_ptr; |
2125 | if (gi) | |
2126 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
2127 | } |
2128 | ||
2129 | static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr) | |
2130 | { | |
2131 | struct glock_iter *gi = iter_ptr; | |
2132 | ||
2133 | gi->seq = file; | |
2134 | dump_glock(gi, gi->gl); | |
2135 | ||
2136 | return 0; | |
2137 | } | |
2138 | ||
4ef29002 | 2139 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
2140 | .start = gfs2_glock_seq_start, |
2141 | .next = gfs2_glock_seq_next, | |
2142 | .stop = gfs2_glock_seq_stop, | |
2143 | .show = gfs2_glock_seq_show, | |
2144 | }; | |
2145 | ||
2146 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
2147 | { | |
2148 | struct seq_file *seq; | |
2149 | int ret; | |
2150 | ||
2151 | ret = seq_open(file, &gfs2_glock_seq_ops); | |
2152 | if (ret) | |
2153 | return ret; | |
2154 | ||
2155 | seq = file->private_data; | |
2156 | seq->private = inode->i_private; | |
2157 | ||
2158 | return 0; | |
2159 | } | |
2160 | ||
2161 | static const struct file_operations gfs2_debug_fops = { | |
2162 | .owner = THIS_MODULE, | |
2163 | .open = gfs2_debugfs_open, | |
2164 | .read = seq_read, | |
2165 | .llseek = seq_lseek, | |
2166 | .release = seq_release | |
2167 | }; | |
2168 | ||
2169 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
2170 | { | |
5f882096 RP |
2171 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
2172 | if (!sdp->debugfs_dir) | |
2173 | return -ENOMEM; | |
2174 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
2175 | S_IFREG | S_IRUGO, | |
2176 | sdp->debugfs_dir, sdp, | |
2177 | &gfs2_debug_fops); | |
2178 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
2179 | return -ENOMEM; |
2180 | ||
2181 | return 0; | |
2182 | } | |
2183 | ||
2184 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
2185 | { | |
5f882096 RP |
2186 | if (sdp && sdp->debugfs_dir) { |
2187 | if (sdp->debugfs_dentry_glocks) { | |
2188 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
2189 | sdp->debugfs_dentry_glocks = NULL; | |
2190 | } | |
2191 | debugfs_remove(sdp->debugfs_dir); | |
2192 | sdp->debugfs_dir = NULL; | |
2193 | } | |
7c52b166 RP |
2194 | } |
2195 | ||
2196 | int gfs2_register_debugfs(void) | |
2197 | { | |
2198 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
2199 | return gfs2_root ? 0 : -ENOMEM; | |
2200 | } | |
2201 | ||
2202 | void gfs2_unregister_debugfs(void) | |
2203 | { | |
2204 | debugfs_remove(gfs2_root); | |
5f882096 | 2205 | gfs2_root = NULL; |
7c52b166 | 2206 | } |