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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> |
61be084e | 23 | #include <linux/rwsem.h> |
b3b94faa DT |
24 | #include <asm/uaccess.h> |
25 | ||
26 | #include "gfs2.h" | |
5c676f6d | 27 | #include "incore.h" |
b3b94faa DT |
28 | #include "glock.h" |
29 | #include "glops.h" | |
30 | #include "inode.h" | |
31 | #include "lm.h" | |
32 | #include "lops.h" | |
33 | #include "meta_io.h" | |
34 | #include "quota.h" | |
35 | #include "super.h" | |
5c676f6d | 36 | #include "util.h" |
b3b94faa | 37 | |
37b2fa6a | 38 | struct gfs2_gl_hash_bucket { |
b6397893 | 39 | struct hlist_head hb_list; |
37b2fa6a SW |
40 | }; |
41 | ||
b3b94faa DT |
42 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
43 | ||
08bc2dbc | 44 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); |
320dd101 | 45 | static int dump_glock(struct gfs2_glock *gl); |
24264434 | 46 | static int dump_inode(struct gfs2_inode *ip); |
b5d32bea SW |
47 | static void gfs2_glock_xmote_th(struct gfs2_holder *gh); |
48 | static void gfs2_glock_drop_th(struct gfs2_glock *gl); | |
61be084e | 49 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
08bc2dbc | 50 | |
b6397893 | 51 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
52 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
53 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
54 | ||
85d1da67 | 55 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
087efdd3 SW |
56 | |
57 | /* | |
58 | * Despite what you might think, the numbers below are not arbitrary :-) | |
59 | * They are taken from the ipv4 routing hash code, which is well tested | |
60 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
61 | * but for now this should be fine. | |
62 | * | |
63 | * The reason for putting the locks in a separate array from the list heads | |
64 | * is that we can have fewer locks than list heads and save memory. We use | |
65 | * the same hash function for both, but with a different hash mask. | |
66 | */ | |
67 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
68 | defined(CONFIG_PROVE_LOCKING) | |
69 | ||
70 | #ifdef CONFIG_LOCKDEP | |
71 | # define GL_HASH_LOCK_SZ 256 | |
72 | #else | |
73 | # if NR_CPUS >= 32 | |
74 | # define GL_HASH_LOCK_SZ 4096 | |
75 | # elif NR_CPUS >= 16 | |
76 | # define GL_HASH_LOCK_SZ 2048 | |
77 | # elif NR_CPUS >= 8 | |
78 | # define GL_HASH_LOCK_SZ 1024 | |
79 | # elif NR_CPUS >= 4 | |
80 | # define GL_HASH_LOCK_SZ 512 | |
81 | # else | |
82 | # define GL_HASH_LOCK_SZ 256 | |
83 | # endif | |
84 | #endif | |
85 | ||
86 | /* We never want more locks than chains */ | |
87 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
88 | # undef GL_HASH_LOCK_SZ | |
89 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
90 | #endif | |
91 | ||
92 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
93 | ||
94 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
95 | { | |
94610610 | 96 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
97 | } |
98 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 99 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
100 | { |
101 | return NULL; | |
102 | } | |
103 | #endif | |
85d1da67 | 104 | |
b3b94faa DT |
105 | /** |
106 | * relaxed_state_ok - is a requested lock compatible with the current lock mode? | |
107 | * @actual: the current state of the lock | |
108 | * @requested: the lock state that was requested by the caller | |
109 | * @flags: the modifier flags passed in by the caller | |
110 | * | |
111 | * Returns: 1 if the locks are compatible, 0 otherwise | |
112 | */ | |
113 | ||
114 | static inline int relaxed_state_ok(unsigned int actual, unsigned requested, | |
115 | int flags) | |
116 | { | |
117 | if (actual == requested) | |
118 | return 1; | |
119 | ||
120 | if (flags & GL_EXACT) | |
121 | return 0; | |
122 | ||
123 | if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) | |
124 | return 1; | |
125 | ||
126 | if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) | |
127 | return 1; | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
132 | /** | |
133 | * gl_hash() - Turn glock number into hash bucket number | |
134 | * @lock: The glock number | |
135 | * | |
136 | * Returns: The number of the corresponding hash bucket | |
137 | */ | |
138 | ||
b8547856 SW |
139 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
140 | const struct lm_lockname *name) | |
b3b94faa DT |
141 | { |
142 | unsigned int h; | |
143 | ||
cd915493 | 144 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 145 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 146 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
147 | h &= GFS2_GL_HASH_MASK; |
148 | ||
149 | return h; | |
150 | } | |
151 | ||
152 | /** | |
153 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
154 | * @gl: The glock to release | |
155 | * | |
156 | * Also calls lock module to release its internal structure for this glock. | |
157 | * | |
158 | */ | |
159 | ||
160 | static void glock_free(struct gfs2_glock *gl) | |
161 | { | |
162 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
163 | struct inode *aspace = gl->gl_aspace; | |
164 | ||
165 | gfs2_lm_put_lock(sdp, gl->gl_lock); | |
166 | ||
167 | if (aspace) | |
168 | gfs2_aspace_put(aspace); | |
169 | ||
170 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
171 | } |
172 | ||
173 | /** | |
174 | * gfs2_glock_hold() - increment reference count on glock | |
175 | * @gl: The glock to hold | |
176 | * | |
177 | */ | |
178 | ||
179 | void gfs2_glock_hold(struct gfs2_glock *gl) | |
180 | { | |
16feb9fe | 181 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
182 | } |
183 | ||
184 | /** | |
185 | * gfs2_glock_put() - Decrement reference count on glock | |
186 | * @gl: The glock to put | |
187 | * | |
188 | */ | |
189 | ||
190 | int gfs2_glock_put(struct gfs2_glock *gl) | |
191 | { | |
b3b94faa | 192 | int rv = 0; |
16feb9fe | 193 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b3b94faa | 194 | |
087efdd3 | 195 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 196 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 197 | hlist_del(&gl->gl_list); |
087efdd3 | 198 | write_unlock(gl_lock_addr(gl->gl_hash)); |
190562bd | 199 | BUG_ON(spin_is_locked(&gl->gl_spin)); |
16feb9fe SW |
200 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); |
201 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
202 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
203 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
204 | gfs2_assert(sdp, list_empty(&gl->gl_waiters2)); | |
205 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); | |
b3b94faa DT |
206 | glock_free(gl); |
207 | rv = 1; | |
208 | goto out; | |
209 | } | |
087efdd3 | 210 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 211 | out: |
b3b94faa DT |
212 | return rv; |
213 | } | |
214 | ||
b3b94faa DT |
215 | /** |
216 | * search_bucket() - Find struct gfs2_glock by lock number | |
217 | * @bucket: the bucket to search | |
218 | * @name: The lock name | |
219 | * | |
220 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
221 | */ | |
222 | ||
37b2fa6a | 223 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 224 | const struct gfs2_sbd *sdp, |
d6a53727 | 225 | const struct lm_lockname *name) |
b3b94faa DT |
226 | { |
227 | struct gfs2_glock *gl; | |
b6397893 | 228 | struct hlist_node *h; |
b3b94faa | 229 | |
b6397893 | 230 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
231 | if (!lm_name_equal(&gl->gl_name, name)) |
232 | continue; | |
899be4d3 SW |
233 | if (gl->gl_sbd != sdp) |
234 | continue; | |
b3b94faa | 235 | |
16feb9fe | 236 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
237 | |
238 | return gl; | |
239 | } | |
240 | ||
241 | return NULL; | |
242 | } | |
243 | ||
244 | /** | |
245 | * gfs2_glock_find() - Find glock by lock number | |
246 | * @sdp: The GFS2 superblock | |
247 | * @name: The lock name | |
248 | * | |
249 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
250 | */ | |
251 | ||
85d1da67 | 252 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 253 | const struct lm_lockname *name) |
b3b94faa | 254 | { |
37b2fa6a | 255 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
256 | struct gfs2_glock *gl; |
257 | ||
087efdd3 | 258 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 259 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 260 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
261 | |
262 | return gl; | |
263 | } | |
264 | ||
265 | /** | |
266 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
267 | * @sdp: The GFS2 superblock | |
268 | * @number: the lock number | |
269 | * @glops: The glock_operations to use | |
270 | * @create: If 0, don't create the glock if it doesn't exist | |
271 | * @glp: the glock is returned here | |
272 | * | |
273 | * This does not lock a glock, just finds/creates structures for one. | |
274 | * | |
275 | * Returns: errno | |
276 | */ | |
277 | ||
cd915493 | 278 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 279 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
280 | struct gfs2_glock **glp) |
281 | { | |
37b2fa6a | 282 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 283 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 284 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
285 | int error; |
286 | ||
087efdd3 | 287 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 288 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 289 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
290 | |
291 | if (gl || !create) { | |
292 | *glp = gl; | |
293 | return 0; | |
294 | } | |
295 | ||
296 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
297 | if (!gl) | |
298 | return -ENOMEM; | |
299 | ||
ec45d9f5 | 300 | gl->gl_flags = 0; |
b3b94faa | 301 | gl->gl_name = name; |
16feb9fe | 302 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 303 | gl->gl_state = LM_ST_UNLOCKED; |
37b2fa6a | 304 | gl->gl_hash = hash; |
320dd101 SW |
305 | gl->gl_owner = NULL; |
306 | gl->gl_ip = 0; | |
b3b94faa | 307 | gl->gl_ops = glops; |
ec45d9f5 SW |
308 | gl->gl_req_gh = NULL; |
309 | gl->gl_req_bh = NULL; | |
310 | gl->gl_vn = 0; | |
311 | gl->gl_stamp = jiffies; | |
312 | gl->gl_object = NULL; | |
b3b94faa | 313 | gl->gl_sbd = sdp; |
ec45d9f5 | 314 | gl->gl_aspace = NULL; |
b3b94faa | 315 | lops_init_le(&gl->gl_le, &gfs2_glock_lops); |
b3b94faa DT |
316 | |
317 | /* If this glock protects actual on-disk data or metadata blocks, | |
318 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 319 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
320 | gl->gl_aspace = gfs2_aspace_get(sdp); |
321 | if (!gl->gl_aspace) { | |
322 | error = -ENOMEM; | |
323 | goto fail; | |
324 | } | |
325 | } | |
326 | ||
327 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
328 | if (error) | |
329 | goto fail_aspace; | |
330 | ||
087efdd3 | 331 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 332 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 333 | if (tmp) { |
087efdd3 | 334 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
335 | glock_free(gl); |
336 | gl = tmp; | |
337 | } else { | |
b6397893 | 338 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 339 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
340 | } |
341 | ||
342 | *glp = gl; | |
343 | ||
344 | return 0; | |
345 | ||
ec45d9f5 | 346 | fail_aspace: |
b3b94faa DT |
347 | if (gl->gl_aspace) |
348 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 349 | fail: |
907b9bce | 350 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
351 | return error; |
352 | } | |
353 | ||
354 | /** | |
355 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
356 | * @gl: the glock | |
357 | * @state: the state we're requesting | |
358 | * @flags: the modifier flags | |
359 | * @gh: the holder structure | |
360 | * | |
361 | */ | |
362 | ||
190562bd | 363 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
364 | struct gfs2_holder *gh) |
365 | { | |
366 | INIT_LIST_HEAD(&gh->gh_list); | |
367 | gh->gh_gl = gl; | |
d0dc80db | 368 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
190562bd | 369 | gh->gh_owner = current; |
b3b94faa DT |
370 | gh->gh_state = state; |
371 | gh->gh_flags = flags; | |
372 | gh->gh_error = 0; | |
373 | gh->gh_iflags = 0; | |
b3b94faa DT |
374 | gfs2_glock_hold(gl); |
375 | } | |
376 | ||
377 | /** | |
378 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
379 | * @state: the state we're requesting | |
380 | * @flags: the modifier flags | |
381 | * @gh: the holder structure | |
382 | * | |
383 | * Don't mess with the glock. | |
384 | * | |
385 | */ | |
386 | ||
190562bd | 387 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
388 | { |
389 | gh->gh_state = state; | |
579b78a4 | 390 | gh->gh_flags = flags; |
b3b94faa | 391 | gh->gh_iflags &= 1 << HIF_ALLOCED; |
d0dc80db | 392 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
393 | } |
394 | ||
395 | /** | |
396 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
397 | * @gh: the holder structure | |
398 | * | |
399 | */ | |
400 | ||
401 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
402 | { | |
403 | gfs2_glock_put(gh->gh_gl); | |
404 | gh->gh_gl = NULL; | |
d0dc80db | 405 | gh->gh_ip = 0; |
b3b94faa DT |
406 | } |
407 | ||
408 | /** | |
409 | * gfs2_holder_get - get a struct gfs2_holder structure | |
410 | * @gl: the glock | |
411 | * @state: the state we're requesting | |
412 | * @flags: the modifier flags | |
af18ddb8 | 413 | * @gfp_flags: |
b3b94faa DT |
414 | * |
415 | * Figure out how big an impact this function has. Either: | |
416 | * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd | |
417 | * 2) Leave it like it is | |
418 | * | |
419 | * Returns: the holder structure, NULL on ENOMEM | |
420 | */ | |
421 | ||
08bc2dbc AB |
422 | static struct gfs2_holder *gfs2_holder_get(struct gfs2_glock *gl, |
423 | unsigned int state, | |
424 | int flags, gfp_t gfp_flags) | |
b3b94faa DT |
425 | { |
426 | struct gfs2_holder *gh; | |
427 | ||
428 | gh = kmalloc(sizeof(struct gfs2_holder), gfp_flags); | |
429 | if (!gh) | |
430 | return NULL; | |
431 | ||
432 | gfs2_holder_init(gl, state, flags, gh); | |
433 | set_bit(HIF_ALLOCED, &gh->gh_iflags); | |
d0dc80db | 434 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
435 | return gh; |
436 | } | |
437 | ||
438 | /** | |
439 | * gfs2_holder_put - get rid of a struct gfs2_holder structure | |
440 | * @gh: the holder structure | |
441 | * | |
442 | */ | |
443 | ||
08bc2dbc | 444 | static void gfs2_holder_put(struct gfs2_holder *gh) |
b3b94faa DT |
445 | { |
446 | gfs2_holder_uninit(gh); | |
447 | kfree(gh); | |
448 | } | |
449 | ||
fee852e3 SW |
450 | static void gfs2_holder_dispose_or_wake(struct gfs2_holder *gh) |
451 | { | |
452 | if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) { | |
453 | gfs2_holder_put(gh); | |
454 | return; | |
455 | } | |
456 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
457 | smp_mb(); | |
458 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
459 | } | |
460 | ||
461 | static int holder_wait(void *word) | |
462 | { | |
463 | schedule(); | |
464 | return 0; | |
465 | } | |
466 | ||
467 | static void wait_on_holder(struct gfs2_holder *gh) | |
468 | { | |
469 | might_sleep(); | |
470 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE); | |
471 | } | |
472 | ||
b3b94faa DT |
473 | /** |
474 | * rq_mutex - process a mutex request in the queue | |
475 | * @gh: the glock holder | |
476 | * | |
477 | * Returns: 1 if the queue is blocked | |
478 | */ | |
479 | ||
480 | static int rq_mutex(struct gfs2_holder *gh) | |
481 | { | |
482 | struct gfs2_glock *gl = gh->gh_gl; | |
483 | ||
484 | list_del_init(&gh->gh_list); | |
485 | /* gh->gh_error never examined. */ | |
486 | set_bit(GLF_LOCK, &gl->gl_flags); | |
d043e190 | 487 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
fee852e3 SW |
488 | smp_mb(); |
489 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
b3b94faa DT |
490 | |
491 | return 1; | |
492 | } | |
493 | ||
494 | /** | |
495 | * rq_promote - process a promote request in the queue | |
496 | * @gh: the glock holder | |
497 | * | |
498 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
499 | * | |
500 | * Returns: 1 if the queue is blocked | |
501 | */ | |
502 | ||
503 | static int rq_promote(struct gfs2_holder *gh) | |
504 | { | |
505 | struct gfs2_glock *gl = gh->gh_gl; | |
506 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa DT |
507 | |
508 | if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
509 | if (list_empty(&gl->gl_holders)) { | |
510 | gl->gl_req_gh = gh; | |
511 | set_bit(GLF_LOCK, &gl->gl_flags); | |
512 | spin_unlock(&gl->gl_spin); | |
513 | ||
514 | if (atomic_read(&sdp->sd_reclaim_count) > | |
515 | gfs2_tune_get(sdp, gt_reclaim_limit) && | |
516 | !(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
517 | gfs2_reclaim_glock(sdp); | |
518 | gfs2_reclaim_glock(sdp); | |
519 | } | |
520 | ||
b5d32bea | 521 | gfs2_glock_xmote_th(gh); |
b3b94faa DT |
522 | spin_lock(&gl->gl_spin); |
523 | } | |
524 | return 1; | |
525 | } | |
526 | ||
527 | if (list_empty(&gl->gl_holders)) { | |
528 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
529 | set_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
530 | } else { |
531 | struct gfs2_holder *next_gh; | |
1c0f4872 | 532 | if (gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa DT |
533 | return 1; |
534 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
535 | gh_list); | |
1c0f4872 | 536 | if (next_gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa | 537 | return 1; |
b3b94faa DT |
538 | } |
539 | ||
540 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
541 | gh->gh_error = 0; | |
542 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
543 | ||
fee852e3 | 544 | gfs2_holder_dispose_or_wake(gh); |
b3b94faa DT |
545 | |
546 | return 0; | |
547 | } | |
548 | ||
549 | /** | |
550 | * rq_demote - process a demote request in the queue | |
551 | * @gh: the glock holder | |
552 | * | |
553 | * Returns: 1 if the queue is blocked | |
554 | */ | |
555 | ||
556 | static int rq_demote(struct gfs2_holder *gh) | |
557 | { | |
558 | struct gfs2_glock *gl = gh->gh_gl; | |
b3b94faa DT |
559 | |
560 | if (!list_empty(&gl->gl_holders)) | |
561 | return 1; | |
562 | ||
563 | if (gl->gl_state == gh->gh_state || gl->gl_state == LM_ST_UNLOCKED) { | |
564 | list_del_init(&gh->gh_list); | |
565 | gh->gh_error = 0; | |
566 | spin_unlock(&gl->gl_spin); | |
fee852e3 | 567 | gfs2_holder_dispose_or_wake(gh); |
b3b94faa DT |
568 | spin_lock(&gl->gl_spin); |
569 | } else { | |
570 | gl->gl_req_gh = gh; | |
571 | set_bit(GLF_LOCK, &gl->gl_flags); | |
572 | spin_unlock(&gl->gl_spin); | |
573 | ||
574 | if (gh->gh_state == LM_ST_UNLOCKED || | |
575 | gl->gl_state != LM_ST_EXCLUSIVE) | |
b5d32bea | 576 | gfs2_glock_drop_th(gl); |
b3b94faa | 577 | else |
b5d32bea | 578 | gfs2_glock_xmote_th(gh); |
b3b94faa DT |
579 | |
580 | spin_lock(&gl->gl_spin); | |
581 | } | |
582 | ||
583 | return 0; | |
584 | } | |
585 | ||
b3b94faa DT |
586 | /** |
587 | * run_queue - process holder structures on a glock | |
588 | * @gl: the glock | |
589 | * | |
590 | */ | |
b3b94faa DT |
591 | static void run_queue(struct gfs2_glock *gl) |
592 | { | |
593 | struct gfs2_holder *gh; | |
594 | int blocked = 1; | |
595 | ||
596 | for (;;) { | |
597 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
598 | break; | |
599 | ||
600 | if (!list_empty(&gl->gl_waiters1)) { | |
601 | gh = list_entry(gl->gl_waiters1.next, | |
602 | struct gfs2_holder, gh_list); | |
603 | ||
604 | if (test_bit(HIF_MUTEX, &gh->gh_iflags)) | |
605 | blocked = rq_mutex(gh); | |
606 | else | |
607 | gfs2_assert_warn(gl->gl_sbd, 0); | |
608 | ||
609 | } else if (!list_empty(&gl->gl_waiters2) && | |
610 | !test_bit(GLF_SKIP_WAITERS2, &gl->gl_flags)) { | |
611 | gh = list_entry(gl->gl_waiters2.next, | |
612 | struct gfs2_holder, gh_list); | |
613 | ||
614 | if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) | |
615 | blocked = rq_demote(gh); | |
b3b94faa DT |
616 | else |
617 | gfs2_assert_warn(gl->gl_sbd, 0); | |
618 | ||
619 | } else if (!list_empty(&gl->gl_waiters3)) { | |
620 | gh = list_entry(gl->gl_waiters3.next, | |
621 | struct gfs2_holder, gh_list); | |
622 | ||
623 | if (test_bit(HIF_PROMOTE, &gh->gh_iflags)) | |
624 | blocked = rq_promote(gh); | |
625 | else | |
626 | gfs2_assert_warn(gl->gl_sbd, 0); | |
627 | ||
628 | } else | |
629 | break; | |
630 | ||
631 | if (blocked) | |
632 | break; | |
633 | } | |
634 | } | |
635 | ||
636 | /** | |
637 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
638 | * @gl: the glock | |
639 | * | |
640 | * Gives caller exclusive access to manipulate a glock structure. | |
641 | */ | |
642 | ||
feaa7bba | 643 | static void gfs2_glmutex_lock(struct gfs2_glock *gl) |
b3b94faa DT |
644 | { |
645 | struct gfs2_holder gh; | |
646 | ||
647 | gfs2_holder_init(gl, 0, 0, &gh); | |
648 | set_bit(HIF_MUTEX, &gh.gh_iflags); | |
fee852e3 SW |
649 | if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags)) |
650 | BUG(); | |
b3b94faa DT |
651 | |
652 | spin_lock(&gl->gl_spin); | |
85d1da67 | 653 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 654 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); |
85d1da67 | 655 | } else { |
320dd101 SW |
656 | gl->gl_owner = current; |
657 | gl->gl_ip = (unsigned long)__builtin_return_address(0); | |
fee852e3 SW |
658 | clear_bit(HIF_WAIT, &gh.gh_iflags); |
659 | smp_mb(); | |
660 | wake_up_bit(&gh.gh_iflags, HIF_WAIT); | |
320dd101 | 661 | } |
b3b94faa DT |
662 | spin_unlock(&gl->gl_spin); |
663 | ||
fee852e3 | 664 | wait_on_holder(&gh); |
b3b94faa DT |
665 | gfs2_holder_uninit(&gh); |
666 | } | |
667 | ||
668 | /** | |
669 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
670 | * @gl: the glock | |
671 | * | |
672 | * Returns: 1 if the glock is acquired | |
673 | */ | |
674 | ||
08bc2dbc | 675 | static int gfs2_glmutex_trylock(struct gfs2_glock *gl) |
b3b94faa DT |
676 | { |
677 | int acquired = 1; | |
678 | ||
679 | spin_lock(&gl->gl_spin); | |
85d1da67 | 680 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 681 | acquired = 0; |
85d1da67 | 682 | } else { |
320dd101 SW |
683 | gl->gl_owner = current; |
684 | gl->gl_ip = (unsigned long)__builtin_return_address(0); | |
685 | } | |
b3b94faa DT |
686 | spin_unlock(&gl->gl_spin); |
687 | ||
688 | return acquired; | |
689 | } | |
690 | ||
691 | /** | |
692 | * gfs2_glmutex_unlock - release a local lock on a glock | |
693 | * @gl: the glock | |
694 | * | |
695 | */ | |
696 | ||
feaa7bba | 697 | static void gfs2_glmutex_unlock(struct gfs2_glock *gl) |
b3b94faa DT |
698 | { |
699 | spin_lock(&gl->gl_spin); | |
700 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
320dd101 SW |
701 | gl->gl_owner = NULL; |
702 | gl->gl_ip = 0; | |
b3b94faa | 703 | run_queue(gl); |
190562bd | 704 | BUG_ON(!spin_is_locked(&gl->gl_spin)); |
b3b94faa DT |
705 | spin_unlock(&gl->gl_spin); |
706 | } | |
707 | ||
708 | /** | |
709 | * handle_callback - add a demote request to a lock's queue | |
710 | * @gl: the glock | |
711 | * @state: the state the caller wants us to change to | |
712 | * | |
af18ddb8 | 713 | * Note: This may fail sliently if we are out of memory. |
b3b94faa DT |
714 | */ |
715 | ||
716 | static void handle_callback(struct gfs2_glock *gl, unsigned int state) | |
717 | { | |
718 | struct gfs2_holder *gh, *new_gh = NULL; | |
719 | ||
feaa7bba | 720 | restart: |
b3b94faa DT |
721 | spin_lock(&gl->gl_spin); |
722 | ||
723 | list_for_each_entry(gh, &gl->gl_waiters2, gh_list) { | |
724 | if (test_bit(HIF_DEMOTE, &gh->gh_iflags) && | |
725 | gl->gl_req_gh != gh) { | |
726 | if (gh->gh_state != state) | |
727 | gh->gh_state = LM_ST_UNLOCKED; | |
728 | goto out; | |
729 | } | |
730 | } | |
731 | ||
732 | if (new_gh) { | |
733 | list_add_tail(&new_gh->gh_list, &gl->gl_waiters2); | |
734 | new_gh = NULL; | |
735 | } else { | |
736 | spin_unlock(&gl->gl_spin); | |
737 | ||
ab923031 | 738 | new_gh = gfs2_holder_get(gl, state, LM_FLAG_TRY, GFP_NOFS); |
af18ddb8 SW |
739 | if (!new_gh) |
740 | return; | |
b3b94faa DT |
741 | set_bit(HIF_DEMOTE, &new_gh->gh_iflags); |
742 | set_bit(HIF_DEALLOC, &new_gh->gh_iflags); | |
fee852e3 | 743 | set_bit(HIF_WAIT, &new_gh->gh_iflags); |
b3b94faa DT |
744 | |
745 | goto restart; | |
746 | } | |
747 | ||
feaa7bba | 748 | out: |
b3b94faa DT |
749 | spin_unlock(&gl->gl_spin); |
750 | ||
751 | if (new_gh) | |
752 | gfs2_holder_put(new_gh); | |
753 | } | |
754 | ||
755 | /** | |
756 | * state_change - record that the glock is now in a different state | |
757 | * @gl: the glock | |
758 | * @new_state the new state | |
759 | * | |
760 | */ | |
761 | ||
762 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
763 | { | |
b3b94faa DT |
764 | int held1, held2; |
765 | ||
766 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
767 | held2 = (new_state != LM_ST_UNLOCKED); | |
768 | ||
769 | if (held1 != held2) { | |
6a6b3d01 | 770 | if (held2) |
b3b94faa | 771 | gfs2_glock_hold(gl); |
6a6b3d01 | 772 | else |
b3b94faa | 773 | gfs2_glock_put(gl); |
b3b94faa DT |
774 | } |
775 | ||
776 | gl->gl_state = new_state; | |
777 | } | |
778 | ||
779 | /** | |
780 | * xmote_bh - Called after the lock module is done acquiring a lock | |
781 | * @gl: The glock in question | |
782 | * @ret: the int returned from the lock module | |
783 | * | |
784 | */ | |
785 | ||
786 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
787 | { | |
788 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 789 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
790 | struct gfs2_holder *gh = gl->gl_req_gh; |
791 | int prev_state = gl->gl_state; | |
792 | int op_done = 1; | |
793 | ||
794 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
12132933 | 795 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
796 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); |
797 | ||
798 | state_change(gl, ret & LM_OUT_ST_MASK); | |
799 | ||
800 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
801 | if (glops->go_inval) | |
1a14d3a6 | 802 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
803 | } else if (gl->gl_state == LM_ST_DEFERRED) { |
804 | /* We might not want to do this here. | |
805 | Look at moving to the inode glops. */ | |
806 | if (glops->go_inval) | |
1a14d3a6 | 807 | glops->go_inval(gl, 0); |
b3b94faa DT |
808 | } |
809 | ||
810 | /* Deal with each possible exit condition */ | |
811 | ||
812 | if (!gh) | |
813 | gl->gl_stamp = jiffies; | |
b3b94faa DT |
814 | else if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
815 | spin_lock(&gl->gl_spin); | |
816 | list_del_init(&gh->gh_list); | |
817 | gh->gh_error = -EIO; | |
b3b94faa | 818 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
819 | } else if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) { |
820 | spin_lock(&gl->gl_spin); | |
821 | list_del_init(&gh->gh_list); | |
822 | if (gl->gl_state == gh->gh_state || | |
85d1da67 | 823 | gl->gl_state == LM_ST_UNLOCKED) { |
b3b94faa | 824 | gh->gh_error = 0; |
85d1da67 | 825 | } else { |
b3b94faa DT |
826 | if (gfs2_assert_warn(sdp, gh->gh_flags & |
827 | (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) == -1) | |
828 | fs_warn(sdp, "ret = 0x%.8X\n", ret); | |
829 | gh->gh_error = GLR_TRYFAILED; | |
830 | } | |
831 | spin_unlock(&gl->gl_spin); | |
832 | ||
833 | if (ret & LM_OUT_CANCELED) | |
50299965 | 834 | handle_callback(gl, LM_ST_UNLOCKED); |
b3b94faa DT |
835 | |
836 | } else if (ret & LM_OUT_CANCELED) { | |
837 | spin_lock(&gl->gl_spin); | |
838 | list_del_init(&gh->gh_list); | |
839 | gh->gh_error = GLR_CANCELED; | |
b3b94faa DT |
840 | spin_unlock(&gl->gl_spin); |
841 | ||
842 | } else if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
843 | spin_lock(&gl->gl_spin); | |
844 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
845 | gh->gh_error = 0; | |
846 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
847 | spin_unlock(&gl->gl_spin); | |
848 | ||
849 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
850 | ||
851 | op_done = 0; | |
852 | ||
853 | } else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
854 | spin_lock(&gl->gl_spin); | |
855 | list_del_init(&gh->gh_list); | |
856 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
857 | spin_unlock(&gl->gl_spin); |
858 | ||
859 | } else { | |
860 | if (gfs2_assert_withdraw(sdp, 0) == -1) | |
861 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
862 | } | |
863 | ||
864 | if (glops->go_xmote_bh) | |
865 | glops->go_xmote_bh(gl); | |
866 | ||
867 | if (op_done) { | |
868 | spin_lock(&gl->gl_spin); | |
869 | gl->gl_req_gh = NULL; | |
870 | gl->gl_req_bh = NULL; | |
871 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
872 | run_queue(gl); | |
873 | spin_unlock(&gl->gl_spin); | |
874 | } | |
875 | ||
876 | gfs2_glock_put(gl); | |
877 | ||
fee852e3 SW |
878 | if (gh) |
879 | gfs2_holder_dispose_or_wake(gh); | |
b3b94faa DT |
880 | } |
881 | ||
882 | /** | |
883 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
884 | * @gl: The glock in question | |
885 | * @state: the requested state | |
886 | * @flags: modifier flags to the lock call | |
887 | * | |
888 | */ | |
889 | ||
b5d32bea | 890 | void gfs2_glock_xmote_th(struct gfs2_holder *gh) |
b3b94faa | 891 | { |
b5d32bea | 892 | struct gfs2_glock *gl = gh->gh_gl; |
b3b94faa | 893 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b5d32bea SW |
894 | int flags = gh->gh_flags; |
895 | unsigned state = gh->gh_state; | |
8fb4b536 | 896 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
897 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | |
898 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
899 | LM_FLAG_PRIORITY); | |
900 | unsigned int lck_ret; | |
901 | ||
b5d32bea SW |
902 | if (glops->go_xmote_th) |
903 | glops->go_xmote_th(gl); | |
904 | ||
b3b94faa | 905 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 906 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
907 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); |
908 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
909 | ||
b3b94faa DT |
910 | gfs2_glock_hold(gl); |
911 | gl->gl_req_bh = xmote_bh; | |
912 | ||
ec45d9f5 | 913 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); |
b3b94faa DT |
914 | |
915 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
916 | return; | |
917 | ||
918 | if (lck_ret & LM_OUT_ASYNC) | |
919 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
920 | else | |
921 | xmote_bh(gl, lck_ret); | |
922 | } | |
923 | ||
924 | /** | |
925 | * drop_bh - Called after a lock module unlock completes | |
926 | * @gl: the glock | |
927 | * @ret: the return status | |
928 | * | |
929 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
930 | * Doesn't drop the reference on the glock the top half took out | |
931 | * | |
932 | */ | |
933 | ||
934 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
935 | { | |
936 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 937 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
938 | struct gfs2_holder *gh = gl->gl_req_gh; |
939 | ||
b3b94faa | 940 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 941 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
942 | gfs2_assert_warn(sdp, !ret); |
943 | ||
944 | state_change(gl, LM_ST_UNLOCKED); | |
945 | ||
946 | if (glops->go_inval) | |
1a14d3a6 | 947 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
948 | |
949 | if (gh) { | |
950 | spin_lock(&gl->gl_spin); | |
951 | list_del_init(&gh->gh_list); | |
952 | gh->gh_error = 0; | |
953 | spin_unlock(&gl->gl_spin); | |
954 | } | |
955 | ||
b3b94faa DT |
956 | spin_lock(&gl->gl_spin); |
957 | gl->gl_req_gh = NULL; | |
958 | gl->gl_req_bh = NULL; | |
959 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
960 | run_queue(gl); | |
961 | spin_unlock(&gl->gl_spin); | |
962 | ||
963 | gfs2_glock_put(gl); | |
964 | ||
fee852e3 SW |
965 | if (gh) |
966 | gfs2_holder_dispose_or_wake(gh); | |
b3b94faa DT |
967 | } |
968 | ||
969 | /** | |
970 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
971 | * @gl: the glock | |
972 | * | |
973 | */ | |
974 | ||
b5d32bea | 975 | static void gfs2_glock_drop_th(struct gfs2_glock *gl) |
b3b94faa DT |
976 | { |
977 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 978 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
979 | unsigned int ret; |
980 | ||
b5d32bea SW |
981 | if (glops->go_drop_th) |
982 | glops->go_drop_th(gl); | |
983 | ||
b3b94faa | 984 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 985 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
986 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); |
987 | ||
b3b94faa DT |
988 | gfs2_glock_hold(gl); |
989 | gl->gl_req_bh = drop_bh; | |
990 | ||
b3b94faa DT |
991 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
992 | ||
993 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
994 | return; | |
995 | ||
996 | if (!ret) | |
997 | drop_bh(gl, ret); | |
998 | else | |
999 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
1000 | } | |
1001 | ||
1002 | /** | |
1003 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
1004 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
1005 | * | |
1006 | * Don't cancel GL_NOCANCEL requests. | |
1007 | */ | |
1008 | ||
1009 | static void do_cancels(struct gfs2_holder *gh) | |
1010 | { | |
1011 | struct gfs2_glock *gl = gh->gh_gl; | |
1012 | ||
1013 | spin_lock(&gl->gl_spin); | |
1014 | ||
1015 | while (gl->gl_req_gh != gh && | |
1016 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1017 | !list_empty(&gh->gh_list)) { | |
50299965 SW |
1018 | if (gl->gl_req_bh && !(gl->gl_req_gh && |
1019 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
b3b94faa DT |
1020 | spin_unlock(&gl->gl_spin); |
1021 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
1022 | msleep(100); | |
1023 | spin_lock(&gl->gl_spin); | |
1024 | } else { | |
1025 | spin_unlock(&gl->gl_spin); | |
1026 | msleep(100); | |
1027 | spin_lock(&gl->gl_spin); | |
1028 | } | |
1029 | } | |
1030 | ||
1031 | spin_unlock(&gl->gl_spin); | |
1032 | } | |
1033 | ||
1034 | /** | |
1035 | * glock_wait_internal - wait on a glock acquisition | |
1036 | * @gh: the glock holder | |
1037 | * | |
1038 | * Returns: 0 on success | |
1039 | */ | |
1040 | ||
1041 | static int glock_wait_internal(struct gfs2_holder *gh) | |
1042 | { | |
1043 | struct gfs2_glock *gl = gh->gh_gl; | |
1044 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 1045 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1046 | |
1047 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
1048 | return -EIO; | |
1049 | ||
1050 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
1051 | spin_lock(&gl->gl_spin); | |
1052 | if (gl->gl_req_gh != gh && | |
1053 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1054 | !list_empty(&gh->gh_list)) { | |
1055 | list_del_init(&gh->gh_list); | |
1056 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
1057 | run_queue(gl); |
1058 | spin_unlock(&gl->gl_spin); | |
1059 | return gh->gh_error; | |
1060 | } | |
1061 | spin_unlock(&gl->gl_spin); | |
1062 | } | |
1063 | ||
1064 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1065 | do_cancels(gh); | |
1066 | ||
fee852e3 | 1067 | wait_on_holder(gh); |
b3b94faa DT |
1068 | if (gh->gh_error) |
1069 | return gh->gh_error; | |
1070 | ||
1071 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
85d1da67 | 1072 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, |
b3b94faa DT |
1073 | gh->gh_flags)); |
1074 | ||
1075 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
1076 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1077 | ||
1078 | if (glops->go_lock) { | |
1079 | gh->gh_error = glops->go_lock(gh); | |
1080 | if (gh->gh_error) { | |
1081 | spin_lock(&gl->gl_spin); | |
1082 | list_del_init(&gh->gh_list); | |
b3b94faa DT |
1083 | spin_unlock(&gl->gl_spin); |
1084 | } | |
1085 | } | |
1086 | ||
1087 | spin_lock(&gl->gl_spin); | |
1088 | gl->gl_req_gh = NULL; | |
1089 | gl->gl_req_bh = NULL; | |
1090 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
1091 | run_queue(gl); |
1092 | spin_unlock(&gl->gl_spin); | |
1093 | } | |
1094 | ||
1095 | return gh->gh_error; | |
1096 | } | |
1097 | ||
1098 | static inline struct gfs2_holder * | |
1099 | find_holder_by_owner(struct list_head *head, struct task_struct *owner) | |
1100 | { | |
1101 | struct gfs2_holder *gh; | |
1102 | ||
1103 | list_for_each_entry(gh, head, gh_list) { | |
1104 | if (gh->gh_owner == owner) | |
1105 | return gh; | |
1106 | } | |
1107 | ||
1108 | return NULL; | |
1109 | } | |
1110 | ||
b3b94faa DT |
1111 | /** |
1112 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1113 | * @gh: the holder structure to add | |
1114 | * | |
1115 | */ | |
1116 | ||
1117 | static void add_to_queue(struct gfs2_holder *gh) | |
1118 | { | |
1119 | struct gfs2_glock *gl = gh->gh_gl; | |
1120 | struct gfs2_holder *existing; | |
1121 | ||
190562bd | 1122 | BUG_ON(!gh->gh_owner); |
fee852e3 SW |
1123 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
1124 | BUG(); | |
190562bd | 1125 | |
b3b94faa DT |
1126 | existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner); |
1127 | if (existing) { | |
5965b1f4 | 1128 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
86384605 | 1129 | printk(KERN_INFO "pid : %d\n", existing->gh_owner->pid); |
907b9bce | 1130 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1131 | existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state); |
5965b1f4 | 1132 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); |
86384605 | 1133 | printk(KERN_INFO "pid : %d\n", gh->gh_owner->pid); |
907b9bce | 1134 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1135 | gl->gl_name.ln_type, gl->gl_state); |
5965b1f4 | 1136 | BUG(); |
b3b94faa DT |
1137 | } |
1138 | ||
1139 | existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner); | |
1140 | if (existing) { | |
5965b1f4 SW |
1141 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
1142 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1143 | BUG(); | |
b3b94faa DT |
1144 | } |
1145 | ||
b3b94faa DT |
1146 | if (gh->gh_flags & LM_FLAG_PRIORITY) |
1147 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1148 | else | |
907b9bce | 1149 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); |
b3b94faa DT |
1150 | } |
1151 | ||
1152 | /** | |
1153 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1154 | * @gh: the holder structure | |
1155 | * | |
1156 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1157 | * | |
1158 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1159 | */ | |
1160 | ||
1161 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1162 | { | |
1163 | struct gfs2_glock *gl = gh->gh_gl; | |
1164 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1165 | int error = 0; | |
1166 | ||
320dd101 | 1167 | restart: |
b3b94faa DT |
1168 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
1169 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1170 | return -EIO; | |
1171 | } | |
1172 | ||
1173 | set_bit(HIF_PROMOTE, &gh->gh_iflags); | |
1174 | ||
1175 | spin_lock(&gl->gl_spin); | |
1176 | add_to_queue(gh); | |
1177 | run_queue(gl); | |
1178 | spin_unlock(&gl->gl_spin); | |
1179 | ||
1180 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1181 | error = glock_wait_internal(gh); | |
1182 | if (error == GLR_CANCELED) { | |
190562bd | 1183 | msleep(100); |
b3b94faa DT |
1184 | goto restart; |
1185 | } | |
1186 | } | |
1187 | ||
b3b94faa DT |
1188 | return error; |
1189 | } | |
1190 | ||
1191 | /** | |
1192 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1193 | * @gh: the holder | |
1194 | * | |
1195 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1196 | */ | |
1197 | ||
1198 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1199 | { | |
1200 | struct gfs2_glock *gl = gh->gh_gl; | |
1201 | int ready = 0; | |
1202 | ||
1203 | spin_lock(&gl->gl_spin); | |
1204 | ||
1205 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1206 | ready = 1; | |
1207 | else if (list_empty(&gh->gh_list)) { | |
1208 | if (gh->gh_error == GLR_CANCELED) { | |
1209 | spin_unlock(&gl->gl_spin); | |
190562bd | 1210 | msleep(100); |
b3b94faa DT |
1211 | if (gfs2_glock_nq(gh)) |
1212 | return 1; | |
1213 | return 0; | |
1214 | } else | |
1215 | ready = 1; | |
1216 | } | |
1217 | ||
1218 | spin_unlock(&gl->gl_spin); | |
1219 | ||
1220 | return ready; | |
1221 | } | |
1222 | ||
1223 | /** | |
1224 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1225 | * @gh: the holder structure | |
1226 | * | |
1227 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1228 | */ | |
1229 | ||
1230 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1231 | { | |
1232 | int error; | |
1233 | ||
1234 | error = glock_wait_internal(gh); | |
1235 | if (error == GLR_CANCELED) { | |
190562bd | 1236 | msleep(100); |
b3b94faa DT |
1237 | gh->gh_flags &= ~GL_ASYNC; |
1238 | error = gfs2_glock_nq(gh); | |
1239 | } | |
1240 | ||
1241 | return error; | |
1242 | } | |
1243 | ||
1244 | /** | |
1245 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1246 | * @gh: the glock holder | |
1247 | * | |
1248 | */ | |
1249 | ||
1250 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1251 | { | |
1252 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1253 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa | 1254 | |
b3b94faa DT |
1255 | if (gh->gh_flags & GL_NOCACHE) |
1256 | handle_callback(gl, LM_ST_UNLOCKED); | |
1257 | ||
1258 | gfs2_glmutex_lock(gl); | |
1259 | ||
1260 | spin_lock(&gl->gl_spin); | |
1261 | list_del_init(&gh->gh_list); | |
1262 | ||
1263 | if (list_empty(&gl->gl_holders)) { | |
1264 | spin_unlock(&gl->gl_spin); | |
1265 | ||
1266 | if (glops->go_unlock) | |
1267 | glops->go_unlock(gh); | |
1268 | ||
b3b94faa DT |
1269 | gl->gl_stamp = jiffies; |
1270 | ||
1271 | spin_lock(&gl->gl_spin); | |
1272 | } | |
1273 | ||
1274 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1275 | run_queue(gl); | |
1276 | spin_unlock(&gl->gl_spin); | |
1277 | } | |
1278 | ||
b3b94faa DT |
1279 | /** |
1280 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1281 | * @gh: the holder structure | |
1282 | * | |
1283 | */ | |
1284 | ||
1285 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1286 | { | |
1287 | gfs2_glock_dq(gh); | |
1288 | gfs2_holder_uninit(gh); | |
1289 | } | |
1290 | ||
1291 | /** | |
1292 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1293 | * @sdp: the filesystem | |
1294 | * @number: the lock number | |
1295 | * @glops: the glock operations for the type of glock | |
1296 | * @state: the state to acquire the glock in | |
1297 | * @flags: modifier flags for the aquisition | |
1298 | * @gh: the struct gfs2_holder | |
1299 | * | |
1300 | * Returns: errno | |
1301 | */ | |
1302 | ||
cd915493 | 1303 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1304 | const struct gfs2_glock_operations *glops, |
1305 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1306 | { |
1307 | struct gfs2_glock *gl; | |
1308 | int error; | |
1309 | ||
1310 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1311 | if (!error) { | |
1312 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1313 | gfs2_glock_put(gl); | |
1314 | } | |
1315 | ||
1316 | return error; | |
1317 | } | |
1318 | ||
1319 | /** | |
1320 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1321 | * @arg_a: the first structure | |
1322 | * @arg_b: the second structure | |
1323 | * | |
1324 | */ | |
1325 | ||
1326 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1327 | { | |
a5e08a9e SW |
1328 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1329 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1330 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1331 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1332 | |
1333 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1334 | return 1; |
1335 | if (a->ln_number < b->ln_number) | |
1336 | return -1; | |
1c0f4872 | 1337 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1338 | return 0; |
b3b94faa DT |
1339 | } |
1340 | ||
1341 | /** | |
1342 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1343 | * @num_gh: the number of structures | |
1344 | * @ghs: an array of struct gfs2_holder structures | |
1345 | * | |
1346 | * Returns: 0 on success (all glocks acquired), | |
1347 | * errno on failure (no glocks acquired) | |
1348 | */ | |
1349 | ||
1350 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1351 | struct gfs2_holder **p) | |
1352 | { | |
1353 | unsigned int x; | |
1354 | int error = 0; | |
1355 | ||
1356 | for (x = 0; x < num_gh; x++) | |
1357 | p[x] = &ghs[x]; | |
1358 | ||
1359 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1360 | ||
1361 | for (x = 0; x < num_gh; x++) { | |
1362 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1363 | ||
1364 | error = gfs2_glock_nq(p[x]); | |
1365 | if (error) { | |
1366 | while (x--) | |
1367 | gfs2_glock_dq(p[x]); | |
1368 | break; | |
1369 | } | |
1370 | } | |
1371 | ||
1372 | return error; | |
1373 | } | |
1374 | ||
1375 | /** | |
1376 | * gfs2_glock_nq_m - acquire multiple glocks | |
1377 | * @num_gh: the number of structures | |
1378 | * @ghs: an array of struct gfs2_holder structures | |
1379 | * | |
1380 | * Figure out how big an impact this function has. Either: | |
1381 | * 1) Replace this code with code that calls gfs2_glock_prefetch() | |
1382 | * 2) Forget async stuff and just call nq_m_sync() | |
1383 | * 3) Leave it like it is | |
1384 | * | |
1385 | * Returns: 0 on success (all glocks acquired), | |
1386 | * errno on failure (no glocks acquired) | |
1387 | */ | |
1388 | ||
1389 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1390 | { | |
1391 | int *e; | |
1392 | unsigned int x; | |
1393 | int borked = 0, serious = 0; | |
1394 | int error = 0; | |
1395 | ||
1396 | if (!num_gh) | |
1397 | return 0; | |
1398 | ||
1399 | if (num_gh == 1) { | |
1400 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1401 | return gfs2_glock_nq(ghs); | |
1402 | } | |
1403 | ||
1404 | e = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL); | |
1405 | if (!e) | |
1406 | return -ENOMEM; | |
1407 | ||
1408 | for (x = 0; x < num_gh; x++) { | |
1409 | ghs[x].gh_flags |= LM_FLAG_TRY | GL_ASYNC; | |
1410 | error = gfs2_glock_nq(&ghs[x]); | |
1411 | if (error) { | |
1412 | borked = 1; | |
1413 | serious = error; | |
1414 | num_gh = x; | |
1415 | break; | |
1416 | } | |
1417 | } | |
1418 | ||
1419 | for (x = 0; x < num_gh; x++) { | |
1420 | error = e[x] = glock_wait_internal(&ghs[x]); | |
1421 | if (error) { | |
1422 | borked = 1; | |
1423 | if (error != GLR_TRYFAILED && error != GLR_CANCELED) | |
1424 | serious = error; | |
1425 | } | |
1426 | } | |
1427 | ||
1428 | if (!borked) { | |
1429 | kfree(e); | |
1430 | return 0; | |
1431 | } | |
1432 | ||
1433 | for (x = 0; x < num_gh; x++) | |
1434 | if (!e[x]) | |
1435 | gfs2_glock_dq(&ghs[x]); | |
1436 | ||
1437 | if (serious) | |
1438 | error = serious; | |
1439 | else { | |
1440 | for (x = 0; x < num_gh; x++) | |
1441 | gfs2_holder_reinit(ghs[x].gh_state, ghs[x].gh_flags, | |
1442 | &ghs[x]); | |
1443 | error = nq_m_sync(num_gh, ghs, (struct gfs2_holder **)e); | |
1444 | } | |
1445 | ||
1446 | kfree(e); | |
1447 | ||
1448 | return error; | |
1449 | } | |
1450 | ||
1451 | /** | |
1452 | * gfs2_glock_dq_m - release multiple glocks | |
1453 | * @num_gh: the number of structures | |
1454 | * @ghs: an array of struct gfs2_holder structures | |
1455 | * | |
1456 | */ | |
1457 | ||
1458 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1459 | { | |
1460 | unsigned int x; | |
1461 | ||
1462 | for (x = 0; x < num_gh; x++) | |
1463 | gfs2_glock_dq(&ghs[x]); | |
1464 | } | |
1465 | ||
1466 | /** | |
1467 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1468 | * @num_gh: the number of structures | |
1469 | * @ghs: an array of struct gfs2_holder structures | |
1470 | * | |
1471 | */ | |
1472 | ||
1473 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1474 | { | |
1475 | unsigned int x; | |
1476 | ||
1477 | for (x = 0; x < num_gh; x++) | |
1478 | gfs2_glock_dq_uninit(&ghs[x]); | |
1479 | } | |
1480 | ||
b3b94faa DT |
1481 | /** |
1482 | * gfs2_lvb_hold - attach a LVB from a glock | |
1483 | * @gl: The glock in question | |
1484 | * | |
1485 | */ | |
1486 | ||
1487 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1488 | { | |
1489 | int error; | |
1490 | ||
1491 | gfs2_glmutex_lock(gl); | |
1492 | ||
1493 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1494 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1495 | if (error) { | |
1496 | gfs2_glmutex_unlock(gl); | |
1497 | return error; | |
1498 | } | |
1499 | gfs2_glock_hold(gl); | |
1500 | } | |
1501 | atomic_inc(&gl->gl_lvb_count); | |
1502 | ||
1503 | gfs2_glmutex_unlock(gl); | |
1504 | ||
1505 | return 0; | |
1506 | } | |
1507 | ||
1508 | /** | |
1509 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1510 | * @gl: The glock in question | |
1511 | * | |
1512 | */ | |
1513 | ||
1514 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1515 | { | |
1516 | gfs2_glock_hold(gl); | |
1517 | gfs2_glmutex_lock(gl); | |
1518 | ||
1519 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1520 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1521 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1522 | gl->gl_lvb = NULL; | |
1523 | gfs2_glock_put(gl); | |
1524 | } | |
1525 | ||
1526 | gfs2_glmutex_unlock(gl); | |
1527 | gfs2_glock_put(gl); | |
1528 | } | |
1529 | ||
b3b94faa DT |
1530 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1531 | unsigned int state) | |
1532 | { | |
1533 | struct gfs2_glock *gl; | |
1534 | ||
1535 | gl = gfs2_glock_find(sdp, name); | |
1536 | if (!gl) | |
1537 | return; | |
1538 | ||
b3b94faa DT |
1539 | handle_callback(gl, state); |
1540 | ||
1541 | spin_lock(&gl->gl_spin); | |
1542 | run_queue(gl); | |
1543 | spin_unlock(&gl->gl_spin); | |
1544 | ||
1545 | gfs2_glock_put(gl); | |
1546 | } | |
1547 | ||
1548 | /** | |
1549 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1550 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1551 | * @type: Type of callback |
1552 | * @data: Type dependent data pointer | |
1553 | * | |
1554 | * Called by the locking module when it wants to tell us something. | |
1555 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1556 | * a journal from another client needs to be recovered. | |
1557 | */ | |
1558 | ||
9b47c11d | 1559 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1560 | { |
9b47c11d | 1561 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1562 | |
b3b94faa DT |
1563 | switch (type) { |
1564 | case LM_CB_NEED_E: | |
e7f5c01c | 1565 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1566 | return; |
1567 | ||
1568 | case LM_CB_NEED_D: | |
e7f5c01c | 1569 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1570 | return; |
1571 | ||
1572 | case LM_CB_NEED_S: | |
e7f5c01c | 1573 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1574 | return; |
1575 | ||
1576 | case LM_CB_ASYNC: { | |
e7f5c01c | 1577 | struct lm_async_cb *async = data; |
b3b94faa DT |
1578 | struct gfs2_glock *gl; |
1579 | ||
61be084e | 1580 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1581 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1582 | if (gfs2_assert_warn(sdp, gl)) | |
1583 | return; | |
1584 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1585 | gl->gl_req_bh(gl, async->lc_ret); | |
1586 | gfs2_glock_put(gl); | |
61be084e | 1587 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1588 | return; |
1589 | } | |
1590 | ||
1591 | case LM_CB_NEED_RECOVERY: | |
1592 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1593 | if (sdp->sd_recoverd_process) | |
1594 | wake_up_process(sdp->sd_recoverd_process); | |
1595 | return; | |
1596 | ||
1597 | case LM_CB_DROPLOCKS: | |
1598 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1599 | gfs2_quota_scan(sdp); | |
1600 | return; | |
1601 | ||
1602 | default: | |
1603 | gfs2_assert_warn(sdp, 0); | |
1604 | return; | |
1605 | } | |
1606 | } | |
1607 | ||
b3b94faa DT |
1608 | /** |
1609 | * demote_ok - Check to see if it's ok to unlock a glock | |
1610 | * @gl: the glock | |
1611 | * | |
1612 | * Returns: 1 if it's ok | |
1613 | */ | |
1614 | ||
1615 | static int demote_ok(struct gfs2_glock *gl) | |
1616 | { | |
8fb4b536 | 1617 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1618 | int demote = 1; |
1619 | ||
1620 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1621 | demote = 0; | |
b3b94faa DT |
1622 | else if (glops->go_demote_ok) |
1623 | demote = glops->go_demote_ok(gl); | |
1624 | ||
1625 | return demote; | |
1626 | } | |
1627 | ||
1628 | /** | |
1629 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1630 | * @gl: the glock | |
1631 | * | |
1632 | */ | |
1633 | ||
1634 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1635 | { | |
1636 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1637 | ||
1638 | spin_lock(&sdp->sd_reclaim_lock); | |
1639 | if (list_empty(&gl->gl_reclaim)) { | |
1640 | gfs2_glock_hold(gl); | |
1641 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1642 | atomic_inc(&sdp->sd_reclaim_count); | |
1643 | } | |
1644 | spin_unlock(&sdp->sd_reclaim_lock); | |
1645 | ||
1646 | wake_up(&sdp->sd_reclaim_wq); | |
1647 | } | |
1648 | ||
1649 | /** | |
1650 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1651 | * @sdp: the filesystem | |
1652 | * | |
1653 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1654 | * different glock and we notice that there are a lot of glocks in the | |
1655 | * reclaim list. | |
1656 | * | |
1657 | */ | |
1658 | ||
1659 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1660 | { | |
1661 | struct gfs2_glock *gl; | |
1662 | ||
1663 | spin_lock(&sdp->sd_reclaim_lock); | |
1664 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1665 | spin_unlock(&sdp->sd_reclaim_lock); | |
1666 | return; | |
1667 | } | |
1668 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1669 | struct gfs2_glock, gl_reclaim); | |
1670 | list_del_init(&gl->gl_reclaim); | |
1671 | spin_unlock(&sdp->sd_reclaim_lock); | |
1672 | ||
1673 | atomic_dec(&sdp->sd_reclaim_count); | |
1674 | atomic_inc(&sdp->sd_reclaimed); | |
1675 | ||
1676 | if (gfs2_glmutex_trylock(gl)) { | |
12132933 | 1677 | if (list_empty(&gl->gl_holders) && |
50299965 | 1678 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa DT |
1679 | handle_callback(gl, LM_ST_UNLOCKED); |
1680 | gfs2_glmutex_unlock(gl); | |
1681 | } | |
1682 | ||
1683 | gfs2_glock_put(gl); | |
1684 | } | |
1685 | ||
1686 | /** | |
1687 | * examine_bucket - Call a function for glock in a hash bucket | |
1688 | * @examiner: the function | |
1689 | * @sdp: the filesystem | |
1690 | * @bucket: the bucket | |
1691 | * | |
1692 | * Returns: 1 if the bucket has entries | |
1693 | */ | |
1694 | ||
1695 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1696 | unsigned int hash) |
b3b94faa | 1697 | { |
24264434 SW |
1698 | struct gfs2_glock *gl, *prev = NULL; |
1699 | int has_entries = 0; | |
b6397893 | 1700 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1701 | |
24264434 | 1702 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1703 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1704 | if (hlist_empty(head)) | |
24264434 | 1705 | goto out; |
b6397893 SW |
1706 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1707 | while(1) { | |
24264434 | 1708 | if (gl->gl_sbd == sdp) { |
b3b94faa | 1709 | gfs2_glock_hold(gl); |
24264434 SW |
1710 | read_unlock(gl_lock_addr(hash)); |
1711 | if (prev) | |
1712 | gfs2_glock_put(prev); | |
1713 | prev = gl; | |
1714 | examiner(gl); | |
a8336344 | 1715 | has_entries = 1; |
24264434 | 1716 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1717 | } |
b6397893 SW |
1718 | if (gl->gl_list.next == NULL) |
1719 | break; | |
24264434 | 1720 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1721 | } |
24264434 SW |
1722 | out: |
1723 | read_unlock(gl_lock_addr(hash)); | |
1724 | if (prev) | |
1725 | gfs2_glock_put(prev); | |
1726 | return has_entries; | |
b3b94faa DT |
1727 | } |
1728 | ||
1729 | /** | |
1730 | * scan_glock - look at a glock and see if we can reclaim it | |
1731 | * @gl: the glock to look at | |
1732 | * | |
1733 | */ | |
1734 | ||
1735 | static void scan_glock(struct gfs2_glock *gl) | |
1736 | { | |
b004157a | 1737 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1738 | return; |
a2242db0 | 1739 | |
b3b94faa | 1740 | if (gfs2_glmutex_trylock(gl)) { |
12132933 | 1741 | if (list_empty(&gl->gl_holders) && |
24264434 | 1742 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa | 1743 | goto out_schedule; |
b3b94faa DT |
1744 | gfs2_glmutex_unlock(gl); |
1745 | } | |
b3b94faa DT |
1746 | return; |
1747 | ||
627add2d | 1748 | out_schedule: |
b3b94faa DT |
1749 | gfs2_glmutex_unlock(gl); |
1750 | gfs2_glock_schedule_for_reclaim(gl); | |
b3b94faa DT |
1751 | } |
1752 | ||
1753 | /** | |
1754 | * gfs2_scand_internal - Look for glocks and inodes to toss from memory | |
1755 | * @sdp: the filesystem | |
1756 | * | |
1757 | */ | |
1758 | ||
1759 | void gfs2_scand_internal(struct gfs2_sbd *sdp) | |
1760 | { | |
1761 | unsigned int x; | |
1762 | ||
94610610 | 1763 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) |
37b2fa6a | 1764 | examine_bucket(scan_glock, sdp, x); |
b3b94faa DT |
1765 | } |
1766 | ||
1767 | /** | |
1768 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1769 | * @gl: the glock to look at | |
1770 | * | |
1771 | */ | |
1772 | ||
1773 | static void clear_glock(struct gfs2_glock *gl) | |
1774 | { | |
1775 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1776 | int released; | |
1777 | ||
1778 | spin_lock(&sdp->sd_reclaim_lock); | |
1779 | if (!list_empty(&gl->gl_reclaim)) { | |
1780 | list_del_init(&gl->gl_reclaim); | |
1781 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1782 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1783 | released = gfs2_glock_put(gl); |
1784 | gfs2_assert(sdp, !released); | |
190562bd SW |
1785 | } else { |
1786 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1787 | } |
b3b94faa DT |
1788 | |
1789 | if (gfs2_glmutex_trylock(gl)) { | |
90101c31 | 1790 | if (list_empty(&gl->gl_holders) && |
b3b94faa DT |
1791 | gl->gl_state != LM_ST_UNLOCKED) |
1792 | handle_callback(gl, LM_ST_UNLOCKED); | |
b3b94faa DT |
1793 | gfs2_glmutex_unlock(gl); |
1794 | } | |
b3b94faa DT |
1795 | } |
1796 | ||
1797 | /** | |
1798 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1799 | * @sdp: the filesystem | |
1800 | * @wait: wait until it's all gone | |
1801 | * | |
1802 | * Called when unmounting the filesystem, or when inter-node lock manager | |
1803 | * requests DROPLOCKS because it is running out of capacity. | |
1804 | */ | |
1805 | ||
1806 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
1807 | { | |
1808 | unsigned long t; | |
1809 | unsigned int x; | |
1810 | int cont; | |
1811 | ||
1812 | t = jiffies; | |
1813 | ||
1814 | for (;;) { | |
1815 | cont = 0; | |
24264434 | 1816 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1817 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1818 | cont = 1; |
24264434 | 1819 | } |
b3b94faa DT |
1820 | |
1821 | if (!wait || !cont) | |
1822 | break; | |
1823 | ||
1824 | if (time_after_eq(jiffies, | |
1825 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1826 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1827 | "Dumping lock state...\n"); | |
1828 | gfs2_dump_lockstate(sdp); | |
1829 | t = jiffies; | |
1830 | } | |
1831 | ||
61be084e | 1832 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1833 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1834 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1835 | msleep(10); |
b3b94faa DT |
1836 | } |
1837 | } | |
1838 | ||
1839 | /* | |
1840 | * Diagnostic routines to help debug distributed deadlock | |
1841 | */ | |
1842 | ||
1843 | /** | |
1844 | * dump_holder - print information about a glock holder | |
1845 | * @str: a string naming the type of holder | |
1846 | * @gh: the glock holder | |
1847 | * | |
1848 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1849 | */ | |
1850 | ||
1851 | static int dump_holder(char *str, struct gfs2_holder *gh) | |
1852 | { | |
1853 | unsigned int x; | |
1854 | int error = -ENOBUFS; | |
1855 | ||
d92a8d48 SW |
1856 | printk(KERN_INFO " %s\n", str); |
1857 | printk(KERN_INFO " owner = %ld\n", | |
b3b94faa | 1858 | (gh->gh_owner) ? (long)gh->gh_owner->pid : -1); |
d92a8d48 SW |
1859 | printk(KERN_INFO " gh_state = %u\n", gh->gh_state); |
1860 | printk(KERN_INFO " gh_flags ="); | |
b3b94faa DT |
1861 | for (x = 0; x < 32; x++) |
1862 | if (gh->gh_flags & (1 << x)) | |
1863 | printk(" %u", x); | |
1864 | printk(" \n"); | |
d92a8d48 SW |
1865 | printk(KERN_INFO " error = %d\n", gh->gh_error); |
1866 | printk(KERN_INFO " gh_iflags ="); | |
b3b94faa DT |
1867 | for (x = 0; x < 32; x++) |
1868 | if (test_bit(x, &gh->gh_iflags)) | |
1869 | printk(" %u", x); | |
1870 | printk(" \n"); | |
d0dc80db | 1871 | print_symbol(KERN_INFO " initialized at: %s\n", gh->gh_ip); |
b3b94faa DT |
1872 | |
1873 | error = 0; | |
1874 | ||
1875 | return error; | |
1876 | } | |
1877 | ||
1878 | /** | |
1879 | * dump_inode - print information about an inode | |
1880 | * @ip: the inode | |
1881 | * | |
1882 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1883 | */ | |
1884 | ||
1885 | static int dump_inode(struct gfs2_inode *ip) | |
1886 | { | |
1887 | unsigned int x; | |
1888 | int error = -ENOBUFS; | |
1889 | ||
d92a8d48 SW |
1890 | printk(KERN_INFO " Inode:\n"); |
1891 | printk(KERN_INFO " num = %llu %llu\n", | |
382066da SW |
1892 | (unsigned long long)ip->i_num.no_formal_ino, |
1893 | (unsigned long long)ip->i_num.no_addr); | |
b60623c2 | 1894 | printk(KERN_INFO " type = %u\n", IF2DT(ip->i_inode.i_mode)); |
d92a8d48 | 1895 | printk(KERN_INFO " i_flags ="); |
b3b94faa DT |
1896 | for (x = 0; x < 32; x++) |
1897 | if (test_bit(x, &ip->i_flags)) | |
1898 | printk(" %u", x); | |
1899 | printk(" \n"); | |
b3b94faa DT |
1900 | |
1901 | error = 0; | |
1902 | ||
1903 | return error; | |
1904 | } | |
1905 | ||
1906 | /** | |
1907 | * dump_glock - print information about a glock | |
1908 | * @gl: the glock | |
1909 | * @count: where we are in the buffer | |
1910 | * | |
1911 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1912 | */ | |
1913 | ||
1914 | static int dump_glock(struct gfs2_glock *gl) | |
1915 | { | |
1916 | struct gfs2_holder *gh; | |
1917 | unsigned int x; | |
1918 | int error = -ENOBUFS; | |
1919 | ||
1920 | spin_lock(&gl->gl_spin); | |
1921 | ||
85d1da67 | 1922 | printk(KERN_INFO "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type, |
382066da | 1923 | (unsigned long long)gl->gl_name.ln_number); |
d92a8d48 | 1924 | printk(KERN_INFO " gl_flags ="); |
85d1da67 | 1925 | for (x = 0; x < 32; x++) { |
b3b94faa DT |
1926 | if (test_bit(x, &gl->gl_flags)) |
1927 | printk(" %u", x); | |
85d1da67 | 1928 | } |
b3b94faa | 1929 | printk(" \n"); |
16feb9fe | 1930 | printk(KERN_INFO " gl_ref = %d\n", atomic_read(&gl->gl_ref)); |
d92a8d48 | 1931 | printk(KERN_INFO " gl_state = %u\n", gl->gl_state); |
320dd101 SW |
1932 | printk(KERN_INFO " gl_owner = %s\n", gl->gl_owner->comm); |
1933 | print_symbol(KERN_INFO " gl_ip = %s\n", gl->gl_ip); | |
d92a8d48 SW |
1934 | printk(KERN_INFO " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); |
1935 | printk(KERN_INFO " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
1936 | printk(KERN_INFO " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
1937 | printk(KERN_INFO " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
1938 | printk(KERN_INFO " le = %s\n", | |
b3b94faa | 1939 | (list_empty(&gl->gl_le.le_list)) ? "no" : "yes"); |
d92a8d48 | 1940 | printk(KERN_INFO " reclaim = %s\n", |
b3b94faa DT |
1941 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); |
1942 | if (gl->gl_aspace) | |
85d1da67 | 1943 | printk(KERN_INFO " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, |
88721877 | 1944 | gl->gl_aspace->i_mapping->nrpages); |
b3b94faa | 1945 | else |
d92a8d48 SW |
1946 | printk(KERN_INFO " aspace = no\n"); |
1947 | printk(KERN_INFO " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa DT |
1948 | if (gl->gl_req_gh) { |
1949 | error = dump_holder("Request", gl->gl_req_gh); | |
1950 | if (error) | |
1951 | goto out; | |
1952 | } | |
1953 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
1954 | error = dump_holder("Holder", gh); | |
1955 | if (error) | |
1956 | goto out; | |
1957 | } | |
1958 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
1959 | error = dump_holder("Waiter1", gh); | |
1960 | if (error) | |
1961 | goto out; | |
1962 | } | |
1963 | list_for_each_entry(gh, &gl->gl_waiters2, gh_list) { | |
1964 | error = dump_holder("Waiter2", gh); | |
1965 | if (error) | |
1966 | goto out; | |
1967 | } | |
1968 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { | |
1969 | error = dump_holder("Waiter3", gh); | |
1970 | if (error) | |
1971 | goto out; | |
1972 | } | |
5c676f6d | 1973 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa DT |
1974 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
1975 | list_empty(&gl->gl_holders)) { | |
5c676f6d | 1976 | error = dump_inode(gl->gl_object); |
b3b94faa DT |
1977 | if (error) |
1978 | goto out; | |
1979 | } else { | |
1980 | error = -ENOBUFS; | |
d92a8d48 | 1981 | printk(KERN_INFO " Inode: busy\n"); |
b3b94faa DT |
1982 | } |
1983 | } | |
1984 | ||
1985 | error = 0; | |
1986 | ||
a91ea69f | 1987 | out: |
b3b94faa | 1988 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
1989 | return error; |
1990 | } | |
1991 | ||
1992 | /** | |
1993 | * gfs2_dump_lockstate - print out the current lockstate | |
1994 | * @sdp: the filesystem | |
1995 | * @ub: the buffer to copy the information into | |
1996 | * | |
1997 | * If @ub is NULL, dump the lockstate to the console. | |
1998 | * | |
1999 | */ | |
2000 | ||
08bc2dbc | 2001 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 2002 | { |
b3b94faa | 2003 | struct gfs2_glock *gl; |
b6397893 | 2004 | struct hlist_node *h; |
b3b94faa DT |
2005 | unsigned int x; |
2006 | int error = 0; | |
2007 | ||
2008 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 2009 | |
087efdd3 | 2010 | read_lock(gl_lock_addr(x)); |
b3b94faa | 2011 | |
b6397893 | 2012 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
2013 | if (gl->gl_sbd != sdp) |
2014 | continue; | |
b3b94faa DT |
2015 | |
2016 | error = dump_glock(gl); | |
2017 | if (error) | |
2018 | break; | |
2019 | } | |
2020 | ||
087efdd3 | 2021 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
2022 | |
2023 | if (error) | |
2024 | break; | |
2025 | } | |
2026 | ||
2027 | ||
2028 | return error; | |
2029 | } | |
2030 | ||
85d1da67 SW |
2031 | int __init gfs2_glock_init(void) |
2032 | { | |
2033 | unsigned i; | |
2034 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 2035 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 2036 | } |
087efdd3 SW |
2037 | #ifdef GL_HASH_LOCK_SZ |
2038 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
2039 | rwlock_init(&gl_hash_locks[i]); | |
2040 | } | |
2041 | #endif | |
85d1da67 SW |
2042 | return 0; |
2043 | } | |
2044 |