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 DT |
25 | #include <asm/uaccess.h> |
26 | ||
27 | #include "gfs2.h" | |
5c676f6d | 28 | #include "incore.h" |
b3b94faa DT |
29 | #include "glock.h" |
30 | #include "glops.h" | |
31 | #include "inode.h" | |
32 | #include "lm.h" | |
33 | #include "lops.h" | |
34 | #include "meta_io.h" | |
35 | #include "quota.h" | |
36 | #include "super.h" | |
5c676f6d | 37 | #include "util.h" |
b3b94faa | 38 | |
37b2fa6a | 39 | struct gfs2_gl_hash_bucket { |
b6397893 | 40 | struct hlist_head hb_list; |
37b2fa6a SW |
41 | }; |
42 | ||
b3b94faa DT |
43 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
44 | ||
08bc2dbc | 45 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); |
320dd101 | 46 | static int dump_glock(struct gfs2_glock *gl); |
24264434 | 47 | static int dump_inode(struct gfs2_inode *ip); |
b5d32bea SW |
48 | static void gfs2_glock_xmote_th(struct gfs2_holder *gh); |
49 | static void gfs2_glock_drop_th(struct gfs2_glock *gl); | |
61be084e | 50 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
08bc2dbc | 51 | |
b6397893 | 52 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
53 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
54 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
55 | ||
85d1da67 | 56 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
087efdd3 SW |
57 | |
58 | /* | |
59 | * Despite what you might think, the numbers below are not arbitrary :-) | |
60 | * They are taken from the ipv4 routing hash code, which is well tested | |
61 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
62 | * but for now this should be fine. | |
63 | * | |
64 | * The reason for putting the locks in a separate array from the list heads | |
65 | * is that we can have fewer locks than list heads and save memory. We use | |
66 | * the same hash function for both, but with a different hash mask. | |
67 | */ | |
68 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
69 | defined(CONFIG_PROVE_LOCKING) | |
70 | ||
71 | #ifdef CONFIG_LOCKDEP | |
72 | # define GL_HASH_LOCK_SZ 256 | |
73 | #else | |
74 | # if NR_CPUS >= 32 | |
75 | # define GL_HASH_LOCK_SZ 4096 | |
76 | # elif NR_CPUS >= 16 | |
77 | # define GL_HASH_LOCK_SZ 2048 | |
78 | # elif NR_CPUS >= 8 | |
79 | # define GL_HASH_LOCK_SZ 1024 | |
80 | # elif NR_CPUS >= 4 | |
81 | # define GL_HASH_LOCK_SZ 512 | |
82 | # else | |
83 | # define GL_HASH_LOCK_SZ 256 | |
84 | # endif | |
85 | #endif | |
86 | ||
87 | /* We never want more locks than chains */ | |
88 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
89 | # undef GL_HASH_LOCK_SZ | |
90 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
91 | #endif | |
92 | ||
93 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
94 | ||
95 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
96 | { | |
94610610 | 97 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
98 | } |
99 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 100 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
101 | { |
102 | return NULL; | |
103 | } | |
104 | #endif | |
85d1da67 | 105 | |
b3b94faa DT |
106 | /** |
107 | * relaxed_state_ok - is a requested lock compatible with the current lock mode? | |
108 | * @actual: the current state of the lock | |
109 | * @requested: the lock state that was requested by the caller | |
110 | * @flags: the modifier flags passed in by the caller | |
111 | * | |
112 | * Returns: 1 if the locks are compatible, 0 otherwise | |
113 | */ | |
114 | ||
115 | static inline int relaxed_state_ok(unsigned int actual, unsigned requested, | |
116 | int flags) | |
117 | { | |
118 | if (actual == requested) | |
119 | return 1; | |
120 | ||
121 | if (flags & GL_EXACT) | |
122 | return 0; | |
123 | ||
124 | if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) | |
125 | return 1; | |
126 | ||
127 | if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) | |
128 | return 1; | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | /** | |
134 | * gl_hash() - Turn glock number into hash bucket number | |
135 | * @lock: The glock number | |
136 | * | |
137 | * Returns: The number of the corresponding hash bucket | |
138 | */ | |
139 | ||
b8547856 SW |
140 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
141 | const struct lm_lockname *name) | |
b3b94faa DT |
142 | { |
143 | unsigned int h; | |
144 | ||
cd915493 | 145 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 146 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 147 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
148 | h &= GFS2_GL_HASH_MASK; |
149 | ||
150 | return h; | |
151 | } | |
152 | ||
153 | /** | |
154 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
155 | * @gl: The glock to release | |
156 | * | |
157 | * Also calls lock module to release its internal structure for this glock. | |
158 | * | |
159 | */ | |
160 | ||
161 | static void glock_free(struct gfs2_glock *gl) | |
162 | { | |
163 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
164 | struct inode *aspace = gl->gl_aspace; | |
165 | ||
166 | gfs2_lm_put_lock(sdp, gl->gl_lock); | |
167 | ||
168 | if (aspace) | |
169 | gfs2_aspace_put(aspace); | |
170 | ||
171 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
172 | } |
173 | ||
174 | /** | |
175 | * gfs2_glock_hold() - increment reference count on glock | |
176 | * @gl: The glock to hold | |
177 | * | |
178 | */ | |
179 | ||
180 | void gfs2_glock_hold(struct gfs2_glock *gl) | |
181 | { | |
16feb9fe | 182 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
183 | } |
184 | ||
185 | /** | |
186 | * gfs2_glock_put() - Decrement reference count on glock | |
187 | * @gl: The glock to put | |
188 | * | |
189 | */ | |
190 | ||
191 | int gfs2_glock_put(struct gfs2_glock *gl) | |
192 | { | |
b3b94faa | 193 | int rv = 0; |
16feb9fe | 194 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b3b94faa | 195 | |
087efdd3 | 196 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 197 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 198 | hlist_del(&gl->gl_list); |
087efdd3 | 199 | write_unlock(gl_lock_addr(gl->gl_hash)); |
190562bd | 200 | BUG_ON(spin_is_locked(&gl->gl_spin)); |
16feb9fe SW |
201 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); |
202 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
203 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
204 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
205 | gfs2_assert(sdp, list_empty(&gl->gl_waiters2)); | |
206 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); | |
b3b94faa DT |
207 | glock_free(gl); |
208 | rv = 1; | |
209 | goto out; | |
210 | } | |
087efdd3 | 211 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 212 | out: |
b3b94faa DT |
213 | return rv; |
214 | } | |
215 | ||
b3b94faa DT |
216 | /** |
217 | * search_bucket() - Find struct gfs2_glock by lock number | |
218 | * @bucket: the bucket to search | |
219 | * @name: The lock name | |
220 | * | |
221 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
222 | */ | |
223 | ||
37b2fa6a | 224 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 225 | const struct gfs2_sbd *sdp, |
d6a53727 | 226 | const struct lm_lockname *name) |
b3b94faa DT |
227 | { |
228 | struct gfs2_glock *gl; | |
b6397893 | 229 | struct hlist_node *h; |
b3b94faa | 230 | |
b6397893 | 231 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
232 | if (!lm_name_equal(&gl->gl_name, name)) |
233 | continue; | |
899be4d3 SW |
234 | if (gl->gl_sbd != sdp) |
235 | continue; | |
b3b94faa | 236 | |
16feb9fe | 237 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
238 | |
239 | return gl; | |
240 | } | |
241 | ||
242 | return NULL; | |
243 | } | |
244 | ||
245 | /** | |
246 | * gfs2_glock_find() - Find glock by lock number | |
247 | * @sdp: The GFS2 superblock | |
248 | * @name: The lock name | |
249 | * | |
250 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
251 | */ | |
252 | ||
85d1da67 | 253 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 254 | const struct lm_lockname *name) |
b3b94faa | 255 | { |
37b2fa6a | 256 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
257 | struct gfs2_glock *gl; |
258 | ||
087efdd3 | 259 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 260 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 261 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
262 | |
263 | return gl; | |
264 | } | |
265 | ||
266 | /** | |
267 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
268 | * @sdp: The GFS2 superblock | |
269 | * @number: the lock number | |
270 | * @glops: The glock_operations to use | |
271 | * @create: If 0, don't create the glock if it doesn't exist | |
272 | * @glp: the glock is returned here | |
273 | * | |
274 | * This does not lock a glock, just finds/creates structures for one. | |
275 | * | |
276 | * Returns: errno | |
277 | */ | |
278 | ||
cd915493 | 279 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 280 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
281 | struct gfs2_glock **glp) |
282 | { | |
37b2fa6a | 283 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 284 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 285 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
286 | int error; |
287 | ||
087efdd3 | 288 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 289 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 290 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
291 | |
292 | if (gl || !create) { | |
293 | *glp = gl; | |
294 | return 0; | |
295 | } | |
296 | ||
297 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
298 | if (!gl) | |
299 | return -ENOMEM; | |
300 | ||
ec45d9f5 | 301 | gl->gl_flags = 0; |
b3b94faa | 302 | gl->gl_name = name; |
16feb9fe | 303 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 304 | gl->gl_state = LM_ST_UNLOCKED; |
37b2fa6a | 305 | gl->gl_hash = hash; |
320dd101 SW |
306 | gl->gl_owner = NULL; |
307 | gl->gl_ip = 0; | |
b3b94faa | 308 | gl->gl_ops = glops; |
ec45d9f5 SW |
309 | gl->gl_req_gh = NULL; |
310 | gl->gl_req_bh = NULL; | |
311 | gl->gl_vn = 0; | |
312 | gl->gl_stamp = jiffies; | |
313 | gl->gl_object = NULL; | |
b3b94faa | 314 | gl->gl_sbd = sdp; |
ec45d9f5 | 315 | gl->gl_aspace = NULL; |
b3b94faa | 316 | lops_init_le(&gl->gl_le, &gfs2_glock_lops); |
b3b94faa DT |
317 | |
318 | /* If this glock protects actual on-disk data or metadata blocks, | |
319 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 320 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
321 | gl->gl_aspace = gfs2_aspace_get(sdp); |
322 | if (!gl->gl_aspace) { | |
323 | error = -ENOMEM; | |
324 | goto fail; | |
325 | } | |
326 | } | |
327 | ||
328 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
329 | if (error) | |
330 | goto fail_aspace; | |
331 | ||
087efdd3 | 332 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 333 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 334 | if (tmp) { |
087efdd3 | 335 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
336 | glock_free(gl); |
337 | gl = tmp; | |
338 | } else { | |
b6397893 | 339 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 340 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
341 | } |
342 | ||
343 | *glp = gl; | |
344 | ||
345 | return 0; | |
346 | ||
ec45d9f5 | 347 | fail_aspace: |
b3b94faa DT |
348 | if (gl->gl_aspace) |
349 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 350 | fail: |
907b9bce | 351 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
352 | return error; |
353 | } | |
354 | ||
355 | /** | |
356 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
357 | * @gl: the glock | |
358 | * @state: the state we're requesting | |
359 | * @flags: the modifier flags | |
360 | * @gh: the holder structure | |
361 | * | |
362 | */ | |
363 | ||
190562bd | 364 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
365 | struct gfs2_holder *gh) |
366 | { | |
367 | INIT_LIST_HEAD(&gh->gh_list); | |
368 | gh->gh_gl = gl; | |
d0dc80db | 369 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
190562bd | 370 | gh->gh_owner = current; |
b3b94faa DT |
371 | gh->gh_state = state; |
372 | gh->gh_flags = flags; | |
373 | gh->gh_error = 0; | |
374 | gh->gh_iflags = 0; | |
b3b94faa DT |
375 | gfs2_glock_hold(gl); |
376 | } | |
377 | ||
378 | /** | |
379 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
380 | * @state: the state we're requesting | |
381 | * @flags: the modifier flags | |
382 | * @gh: the holder structure | |
383 | * | |
384 | * Don't mess with the glock. | |
385 | * | |
386 | */ | |
387 | ||
190562bd | 388 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
389 | { |
390 | gh->gh_state = state; | |
579b78a4 | 391 | gh->gh_flags = flags; |
b3b94faa | 392 | gh->gh_iflags &= 1 << HIF_ALLOCED; |
d0dc80db | 393 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
394 | } |
395 | ||
396 | /** | |
397 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
398 | * @gh: the holder structure | |
399 | * | |
400 | */ | |
401 | ||
402 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
403 | { | |
404 | gfs2_glock_put(gh->gh_gl); | |
405 | gh->gh_gl = NULL; | |
d0dc80db | 406 | gh->gh_ip = 0; |
b3b94faa DT |
407 | } |
408 | ||
409 | /** | |
410 | * gfs2_holder_get - get a struct gfs2_holder structure | |
411 | * @gl: the glock | |
412 | * @state: the state we're requesting | |
413 | * @flags: the modifier flags | |
af18ddb8 | 414 | * @gfp_flags: |
b3b94faa DT |
415 | * |
416 | * Figure out how big an impact this function has. Either: | |
417 | * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd | |
418 | * 2) Leave it like it is | |
419 | * | |
420 | * Returns: the holder structure, NULL on ENOMEM | |
421 | */ | |
422 | ||
08bc2dbc AB |
423 | static struct gfs2_holder *gfs2_holder_get(struct gfs2_glock *gl, |
424 | unsigned int state, | |
425 | int flags, gfp_t gfp_flags) | |
b3b94faa DT |
426 | { |
427 | struct gfs2_holder *gh; | |
428 | ||
429 | gh = kmalloc(sizeof(struct gfs2_holder), gfp_flags); | |
430 | if (!gh) | |
431 | return NULL; | |
432 | ||
433 | gfs2_holder_init(gl, state, flags, gh); | |
434 | set_bit(HIF_ALLOCED, &gh->gh_iflags); | |
d0dc80db | 435 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
436 | return gh; |
437 | } | |
438 | ||
439 | /** | |
440 | * gfs2_holder_put - get rid of a struct gfs2_holder structure | |
441 | * @gh: the holder structure | |
442 | * | |
443 | */ | |
444 | ||
08bc2dbc | 445 | static void gfs2_holder_put(struct gfs2_holder *gh) |
b3b94faa DT |
446 | { |
447 | gfs2_holder_uninit(gh); | |
448 | kfree(gh); | |
449 | } | |
450 | ||
fee852e3 SW |
451 | static void gfs2_holder_dispose_or_wake(struct gfs2_holder *gh) |
452 | { | |
453 | if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) { | |
454 | gfs2_holder_put(gh); | |
455 | return; | |
456 | } | |
457 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
458 | smp_mb(); | |
459 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
460 | } | |
461 | ||
462 | static int holder_wait(void *word) | |
463 | { | |
464 | schedule(); | |
465 | return 0; | |
466 | } | |
467 | ||
468 | static void wait_on_holder(struct gfs2_holder *gh) | |
469 | { | |
470 | might_sleep(); | |
471 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE); | |
472 | } | |
473 | ||
b3b94faa DT |
474 | /** |
475 | * rq_mutex - process a mutex request in the queue | |
476 | * @gh: the glock holder | |
477 | * | |
478 | * Returns: 1 if the queue is blocked | |
479 | */ | |
480 | ||
481 | static int rq_mutex(struct gfs2_holder *gh) | |
482 | { | |
483 | struct gfs2_glock *gl = gh->gh_gl; | |
484 | ||
485 | list_del_init(&gh->gh_list); | |
486 | /* gh->gh_error never examined. */ | |
487 | set_bit(GLF_LOCK, &gl->gl_flags); | |
d043e190 | 488 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
fee852e3 SW |
489 | smp_mb(); |
490 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
b3b94faa DT |
491 | |
492 | return 1; | |
493 | } | |
494 | ||
495 | /** | |
496 | * rq_promote - process a promote request in the queue | |
497 | * @gh: the glock holder | |
498 | * | |
499 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
500 | * | |
501 | * Returns: 1 if the queue is blocked | |
502 | */ | |
503 | ||
504 | static int rq_promote(struct gfs2_holder *gh) | |
505 | { | |
506 | struct gfs2_glock *gl = gh->gh_gl; | |
507 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa DT |
508 | |
509 | if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
510 | if (list_empty(&gl->gl_holders)) { | |
511 | gl->gl_req_gh = gh; | |
512 | set_bit(GLF_LOCK, &gl->gl_flags); | |
513 | spin_unlock(&gl->gl_spin); | |
514 | ||
515 | if (atomic_read(&sdp->sd_reclaim_count) > | |
516 | gfs2_tune_get(sdp, gt_reclaim_limit) && | |
517 | !(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
518 | gfs2_reclaim_glock(sdp); | |
519 | gfs2_reclaim_glock(sdp); | |
520 | } | |
521 | ||
b5d32bea | 522 | gfs2_glock_xmote_th(gh); |
b3b94faa DT |
523 | spin_lock(&gl->gl_spin); |
524 | } | |
525 | return 1; | |
526 | } | |
527 | ||
528 | if (list_empty(&gl->gl_holders)) { | |
529 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
530 | set_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
531 | } else { |
532 | struct gfs2_holder *next_gh; | |
1c0f4872 | 533 | if (gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa DT |
534 | return 1; |
535 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
536 | gh_list); | |
1c0f4872 | 537 | if (next_gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa | 538 | return 1; |
b3b94faa DT |
539 | } |
540 | ||
541 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
542 | gh->gh_error = 0; | |
543 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
544 | ||
fee852e3 | 545 | gfs2_holder_dispose_or_wake(gh); |
b3b94faa DT |
546 | |
547 | return 0; | |
548 | } | |
549 | ||
550 | /** | |
551 | * rq_demote - process a demote request in the queue | |
552 | * @gh: the glock holder | |
553 | * | |
554 | * Returns: 1 if the queue is blocked | |
555 | */ | |
556 | ||
557 | static int rq_demote(struct gfs2_holder *gh) | |
558 | { | |
559 | struct gfs2_glock *gl = gh->gh_gl; | |
b3b94faa DT |
560 | |
561 | if (!list_empty(&gl->gl_holders)) | |
562 | return 1; | |
563 | ||
564 | if (gl->gl_state == gh->gh_state || gl->gl_state == LM_ST_UNLOCKED) { | |
565 | list_del_init(&gh->gh_list); | |
566 | gh->gh_error = 0; | |
567 | spin_unlock(&gl->gl_spin); | |
fee852e3 | 568 | gfs2_holder_dispose_or_wake(gh); |
b3b94faa DT |
569 | spin_lock(&gl->gl_spin); |
570 | } else { | |
571 | gl->gl_req_gh = gh; | |
572 | set_bit(GLF_LOCK, &gl->gl_flags); | |
573 | spin_unlock(&gl->gl_spin); | |
574 | ||
575 | if (gh->gh_state == LM_ST_UNLOCKED || | |
576 | gl->gl_state != LM_ST_EXCLUSIVE) | |
b5d32bea | 577 | gfs2_glock_drop_th(gl); |
b3b94faa | 578 | else |
b5d32bea | 579 | gfs2_glock_xmote_th(gh); |
b3b94faa DT |
580 | |
581 | spin_lock(&gl->gl_spin); | |
582 | } | |
583 | ||
584 | return 0; | |
585 | } | |
586 | ||
b3b94faa DT |
587 | /** |
588 | * run_queue - process holder structures on a glock | |
589 | * @gl: the glock | |
590 | * | |
591 | */ | |
b3b94faa DT |
592 | static void run_queue(struct gfs2_glock *gl) |
593 | { | |
594 | struct gfs2_holder *gh; | |
595 | int blocked = 1; | |
596 | ||
597 | for (;;) { | |
598 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
599 | break; | |
600 | ||
601 | if (!list_empty(&gl->gl_waiters1)) { | |
602 | gh = list_entry(gl->gl_waiters1.next, | |
603 | struct gfs2_holder, gh_list); | |
604 | ||
605 | if (test_bit(HIF_MUTEX, &gh->gh_iflags)) | |
606 | blocked = rq_mutex(gh); | |
607 | else | |
608 | gfs2_assert_warn(gl->gl_sbd, 0); | |
609 | ||
610 | } else if (!list_empty(&gl->gl_waiters2) && | |
611 | !test_bit(GLF_SKIP_WAITERS2, &gl->gl_flags)) { | |
612 | gh = list_entry(gl->gl_waiters2.next, | |
613 | struct gfs2_holder, gh_list); | |
614 | ||
615 | if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) | |
616 | blocked = rq_demote(gh); | |
b3b94faa DT |
617 | else |
618 | gfs2_assert_warn(gl->gl_sbd, 0); | |
619 | ||
620 | } else if (!list_empty(&gl->gl_waiters3)) { | |
621 | gh = list_entry(gl->gl_waiters3.next, | |
622 | struct gfs2_holder, gh_list); | |
623 | ||
624 | if (test_bit(HIF_PROMOTE, &gh->gh_iflags)) | |
625 | blocked = rq_promote(gh); | |
626 | else | |
627 | gfs2_assert_warn(gl->gl_sbd, 0); | |
628 | ||
629 | } else | |
630 | break; | |
631 | ||
632 | if (blocked) | |
633 | break; | |
634 | } | |
635 | } | |
636 | ||
637 | /** | |
638 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
639 | * @gl: the glock | |
640 | * | |
641 | * Gives caller exclusive access to manipulate a glock structure. | |
642 | */ | |
643 | ||
feaa7bba | 644 | static void gfs2_glmutex_lock(struct gfs2_glock *gl) |
b3b94faa DT |
645 | { |
646 | struct gfs2_holder gh; | |
647 | ||
648 | gfs2_holder_init(gl, 0, 0, &gh); | |
649 | set_bit(HIF_MUTEX, &gh.gh_iflags); | |
fee852e3 SW |
650 | if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags)) |
651 | BUG(); | |
b3b94faa DT |
652 | |
653 | spin_lock(&gl->gl_spin); | |
85d1da67 | 654 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 655 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); |
85d1da67 | 656 | } else { |
320dd101 SW |
657 | gl->gl_owner = current; |
658 | gl->gl_ip = (unsigned long)__builtin_return_address(0); | |
fee852e3 SW |
659 | clear_bit(HIF_WAIT, &gh.gh_iflags); |
660 | smp_mb(); | |
661 | wake_up_bit(&gh.gh_iflags, HIF_WAIT); | |
320dd101 | 662 | } |
b3b94faa DT |
663 | spin_unlock(&gl->gl_spin); |
664 | ||
fee852e3 | 665 | wait_on_holder(&gh); |
b3b94faa DT |
666 | gfs2_holder_uninit(&gh); |
667 | } | |
668 | ||
669 | /** | |
670 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
671 | * @gl: the glock | |
672 | * | |
673 | * Returns: 1 if the glock is acquired | |
674 | */ | |
675 | ||
08bc2dbc | 676 | static int gfs2_glmutex_trylock(struct gfs2_glock *gl) |
b3b94faa DT |
677 | { |
678 | int acquired = 1; | |
679 | ||
680 | spin_lock(&gl->gl_spin); | |
85d1da67 | 681 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 682 | acquired = 0; |
85d1da67 | 683 | } else { |
320dd101 SW |
684 | gl->gl_owner = current; |
685 | gl->gl_ip = (unsigned long)__builtin_return_address(0); | |
686 | } | |
b3b94faa DT |
687 | spin_unlock(&gl->gl_spin); |
688 | ||
689 | return acquired; | |
690 | } | |
691 | ||
692 | /** | |
693 | * gfs2_glmutex_unlock - release a local lock on a glock | |
694 | * @gl: the glock | |
695 | * | |
696 | */ | |
697 | ||
feaa7bba | 698 | static void gfs2_glmutex_unlock(struct gfs2_glock *gl) |
b3b94faa DT |
699 | { |
700 | spin_lock(&gl->gl_spin); | |
701 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
320dd101 SW |
702 | gl->gl_owner = NULL; |
703 | gl->gl_ip = 0; | |
b3b94faa | 704 | run_queue(gl); |
190562bd | 705 | BUG_ON(!spin_is_locked(&gl->gl_spin)); |
b3b94faa DT |
706 | spin_unlock(&gl->gl_spin); |
707 | } | |
708 | ||
709 | /** | |
710 | * handle_callback - add a demote request to a lock's queue | |
711 | * @gl: the glock | |
712 | * @state: the state the caller wants us to change to | |
713 | * | |
af18ddb8 | 714 | * Note: This may fail sliently if we are out of memory. |
b3b94faa DT |
715 | */ |
716 | ||
717 | static void handle_callback(struct gfs2_glock *gl, unsigned int state) | |
718 | { | |
719 | struct gfs2_holder *gh, *new_gh = NULL; | |
720 | ||
feaa7bba | 721 | restart: |
b3b94faa DT |
722 | spin_lock(&gl->gl_spin); |
723 | ||
724 | list_for_each_entry(gh, &gl->gl_waiters2, gh_list) { | |
725 | if (test_bit(HIF_DEMOTE, &gh->gh_iflags) && | |
726 | gl->gl_req_gh != gh) { | |
727 | if (gh->gh_state != state) | |
728 | gh->gh_state = LM_ST_UNLOCKED; | |
729 | goto out; | |
730 | } | |
731 | } | |
732 | ||
733 | if (new_gh) { | |
734 | list_add_tail(&new_gh->gh_list, &gl->gl_waiters2); | |
735 | new_gh = NULL; | |
736 | } else { | |
737 | spin_unlock(&gl->gl_spin); | |
738 | ||
ab923031 | 739 | new_gh = gfs2_holder_get(gl, state, LM_FLAG_TRY, GFP_NOFS); |
af18ddb8 SW |
740 | if (!new_gh) |
741 | return; | |
b3b94faa DT |
742 | set_bit(HIF_DEMOTE, &new_gh->gh_iflags); |
743 | set_bit(HIF_DEALLOC, &new_gh->gh_iflags); | |
fee852e3 | 744 | set_bit(HIF_WAIT, &new_gh->gh_iflags); |
b3b94faa DT |
745 | |
746 | goto restart; | |
747 | } | |
748 | ||
feaa7bba | 749 | out: |
b3b94faa DT |
750 | spin_unlock(&gl->gl_spin); |
751 | ||
752 | if (new_gh) | |
753 | gfs2_holder_put(new_gh); | |
754 | } | |
755 | ||
756 | /** | |
757 | * state_change - record that the glock is now in a different state | |
758 | * @gl: the glock | |
759 | * @new_state the new state | |
760 | * | |
761 | */ | |
762 | ||
763 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
764 | { | |
b3b94faa DT |
765 | int held1, held2; |
766 | ||
767 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
768 | held2 = (new_state != LM_ST_UNLOCKED); | |
769 | ||
770 | if (held1 != held2) { | |
6a6b3d01 | 771 | if (held2) |
b3b94faa | 772 | gfs2_glock_hold(gl); |
6a6b3d01 | 773 | else |
b3b94faa | 774 | gfs2_glock_put(gl); |
b3b94faa DT |
775 | } |
776 | ||
777 | gl->gl_state = new_state; | |
778 | } | |
779 | ||
780 | /** | |
781 | * xmote_bh - Called after the lock module is done acquiring a lock | |
782 | * @gl: The glock in question | |
783 | * @ret: the int returned from the lock module | |
784 | * | |
785 | */ | |
786 | ||
787 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
788 | { | |
789 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 790 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
791 | struct gfs2_holder *gh = gl->gl_req_gh; |
792 | int prev_state = gl->gl_state; | |
793 | int op_done = 1; | |
794 | ||
795 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
12132933 | 796 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
797 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); |
798 | ||
799 | state_change(gl, ret & LM_OUT_ST_MASK); | |
800 | ||
801 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
802 | if (glops->go_inval) | |
1a14d3a6 | 803 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
804 | } else if (gl->gl_state == LM_ST_DEFERRED) { |
805 | /* We might not want to do this here. | |
806 | Look at moving to the inode glops. */ | |
807 | if (glops->go_inval) | |
1a14d3a6 | 808 | glops->go_inval(gl, 0); |
b3b94faa DT |
809 | } |
810 | ||
811 | /* Deal with each possible exit condition */ | |
812 | ||
813 | if (!gh) | |
814 | gl->gl_stamp = jiffies; | |
b3b94faa DT |
815 | else if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
816 | spin_lock(&gl->gl_spin); | |
817 | list_del_init(&gh->gh_list); | |
818 | gh->gh_error = -EIO; | |
b3b94faa | 819 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
820 | } else if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) { |
821 | spin_lock(&gl->gl_spin); | |
822 | list_del_init(&gh->gh_list); | |
823 | if (gl->gl_state == gh->gh_state || | |
85d1da67 | 824 | gl->gl_state == LM_ST_UNLOCKED) { |
b3b94faa | 825 | gh->gh_error = 0; |
85d1da67 | 826 | } else { |
b3b94faa DT |
827 | if (gfs2_assert_warn(sdp, gh->gh_flags & |
828 | (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) == -1) | |
829 | fs_warn(sdp, "ret = 0x%.8X\n", ret); | |
830 | gh->gh_error = GLR_TRYFAILED; | |
831 | } | |
832 | spin_unlock(&gl->gl_spin); | |
833 | ||
834 | if (ret & LM_OUT_CANCELED) | |
50299965 | 835 | handle_callback(gl, LM_ST_UNLOCKED); |
b3b94faa DT |
836 | |
837 | } else if (ret & LM_OUT_CANCELED) { | |
838 | spin_lock(&gl->gl_spin); | |
839 | list_del_init(&gh->gh_list); | |
840 | gh->gh_error = GLR_CANCELED; | |
b3b94faa DT |
841 | spin_unlock(&gl->gl_spin); |
842 | ||
843 | } else if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
844 | spin_lock(&gl->gl_spin); | |
845 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
846 | gh->gh_error = 0; | |
847 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
848 | spin_unlock(&gl->gl_spin); | |
849 | ||
850 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
851 | ||
852 | op_done = 0; | |
853 | ||
854 | } else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
855 | spin_lock(&gl->gl_spin); | |
856 | list_del_init(&gh->gh_list); | |
857 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
858 | spin_unlock(&gl->gl_spin); |
859 | ||
860 | } else { | |
861 | if (gfs2_assert_withdraw(sdp, 0) == -1) | |
862 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
863 | } | |
864 | ||
865 | if (glops->go_xmote_bh) | |
866 | glops->go_xmote_bh(gl); | |
867 | ||
868 | if (op_done) { | |
869 | spin_lock(&gl->gl_spin); | |
870 | gl->gl_req_gh = NULL; | |
871 | gl->gl_req_bh = NULL; | |
872 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
873 | run_queue(gl); | |
874 | spin_unlock(&gl->gl_spin); | |
875 | } | |
876 | ||
877 | gfs2_glock_put(gl); | |
878 | ||
fee852e3 SW |
879 | if (gh) |
880 | gfs2_holder_dispose_or_wake(gh); | |
b3b94faa DT |
881 | } |
882 | ||
883 | /** | |
884 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
885 | * @gl: The glock in question | |
886 | * @state: the requested state | |
887 | * @flags: modifier flags to the lock call | |
888 | * | |
889 | */ | |
890 | ||
b5d32bea | 891 | void gfs2_glock_xmote_th(struct gfs2_holder *gh) |
b3b94faa | 892 | { |
b5d32bea | 893 | struct gfs2_glock *gl = gh->gh_gl; |
b3b94faa | 894 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b5d32bea SW |
895 | int flags = gh->gh_flags; |
896 | unsigned state = gh->gh_state; | |
8fb4b536 | 897 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
898 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | |
899 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
900 | LM_FLAG_PRIORITY); | |
901 | unsigned int lck_ret; | |
902 | ||
b5d32bea SW |
903 | if (glops->go_xmote_th) |
904 | glops->go_xmote_th(gl); | |
905 | ||
b3b94faa | 906 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 907 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
908 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); |
909 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
910 | ||
b3b94faa DT |
911 | gfs2_glock_hold(gl); |
912 | gl->gl_req_bh = xmote_bh; | |
913 | ||
ec45d9f5 | 914 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); |
b3b94faa DT |
915 | |
916 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
917 | return; | |
918 | ||
919 | if (lck_ret & LM_OUT_ASYNC) | |
920 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
921 | else | |
922 | xmote_bh(gl, lck_ret); | |
923 | } | |
924 | ||
925 | /** | |
926 | * drop_bh - Called after a lock module unlock completes | |
927 | * @gl: the glock | |
928 | * @ret: the return status | |
929 | * | |
930 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
931 | * Doesn't drop the reference on the glock the top half took out | |
932 | * | |
933 | */ | |
934 | ||
935 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
936 | { | |
937 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 938 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
939 | struct gfs2_holder *gh = gl->gl_req_gh; |
940 | ||
b3b94faa | 941 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 942 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
943 | gfs2_assert_warn(sdp, !ret); |
944 | ||
945 | state_change(gl, LM_ST_UNLOCKED); | |
946 | ||
947 | if (glops->go_inval) | |
1a14d3a6 | 948 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
949 | |
950 | if (gh) { | |
951 | spin_lock(&gl->gl_spin); | |
952 | list_del_init(&gh->gh_list); | |
953 | gh->gh_error = 0; | |
954 | spin_unlock(&gl->gl_spin); | |
955 | } | |
956 | ||
b3b94faa DT |
957 | spin_lock(&gl->gl_spin); |
958 | gl->gl_req_gh = NULL; | |
959 | gl->gl_req_bh = NULL; | |
960 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
961 | run_queue(gl); | |
962 | spin_unlock(&gl->gl_spin); | |
963 | ||
964 | gfs2_glock_put(gl); | |
965 | ||
fee852e3 SW |
966 | if (gh) |
967 | gfs2_holder_dispose_or_wake(gh); | |
b3b94faa DT |
968 | } |
969 | ||
970 | /** | |
971 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
972 | * @gl: the glock | |
973 | * | |
974 | */ | |
975 | ||
b5d32bea | 976 | static void gfs2_glock_drop_th(struct gfs2_glock *gl) |
b3b94faa DT |
977 | { |
978 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 979 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
980 | unsigned int ret; |
981 | ||
b5d32bea SW |
982 | if (glops->go_drop_th) |
983 | glops->go_drop_th(gl); | |
984 | ||
b3b94faa | 985 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 986 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
987 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); |
988 | ||
b3b94faa DT |
989 | gfs2_glock_hold(gl); |
990 | gl->gl_req_bh = drop_bh; | |
991 | ||
b3b94faa DT |
992 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
993 | ||
994 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
995 | return; | |
996 | ||
997 | if (!ret) | |
998 | drop_bh(gl, ret); | |
999 | else | |
1000 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
1001 | } | |
1002 | ||
1003 | /** | |
1004 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
1005 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
1006 | * | |
1007 | * Don't cancel GL_NOCANCEL requests. | |
1008 | */ | |
1009 | ||
1010 | static void do_cancels(struct gfs2_holder *gh) | |
1011 | { | |
1012 | struct gfs2_glock *gl = gh->gh_gl; | |
1013 | ||
1014 | spin_lock(&gl->gl_spin); | |
1015 | ||
1016 | while (gl->gl_req_gh != gh && | |
1017 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1018 | !list_empty(&gh->gh_list)) { | |
50299965 SW |
1019 | if (gl->gl_req_bh && !(gl->gl_req_gh && |
1020 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
b3b94faa DT |
1021 | spin_unlock(&gl->gl_spin); |
1022 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
1023 | msleep(100); | |
1024 | spin_lock(&gl->gl_spin); | |
1025 | } else { | |
1026 | spin_unlock(&gl->gl_spin); | |
1027 | msleep(100); | |
1028 | spin_lock(&gl->gl_spin); | |
1029 | } | |
1030 | } | |
1031 | ||
1032 | spin_unlock(&gl->gl_spin); | |
1033 | } | |
1034 | ||
1035 | /** | |
1036 | * glock_wait_internal - wait on a glock acquisition | |
1037 | * @gh: the glock holder | |
1038 | * | |
1039 | * Returns: 0 on success | |
1040 | */ | |
1041 | ||
1042 | static int glock_wait_internal(struct gfs2_holder *gh) | |
1043 | { | |
1044 | struct gfs2_glock *gl = gh->gh_gl; | |
1045 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 1046 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1047 | |
1048 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
1049 | return -EIO; | |
1050 | ||
1051 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
1052 | spin_lock(&gl->gl_spin); | |
1053 | if (gl->gl_req_gh != gh && | |
1054 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1055 | !list_empty(&gh->gh_list)) { | |
1056 | list_del_init(&gh->gh_list); | |
1057 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
1058 | run_queue(gl); |
1059 | spin_unlock(&gl->gl_spin); | |
1060 | return gh->gh_error; | |
1061 | } | |
1062 | spin_unlock(&gl->gl_spin); | |
1063 | } | |
1064 | ||
1065 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1066 | do_cancels(gh); | |
1067 | ||
fee852e3 | 1068 | wait_on_holder(gh); |
b3b94faa DT |
1069 | if (gh->gh_error) |
1070 | return gh->gh_error; | |
1071 | ||
1072 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
85d1da67 | 1073 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, |
b3b94faa DT |
1074 | gh->gh_flags)); |
1075 | ||
1076 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
1077 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1078 | ||
1079 | if (glops->go_lock) { | |
1080 | gh->gh_error = glops->go_lock(gh); | |
1081 | if (gh->gh_error) { | |
1082 | spin_lock(&gl->gl_spin); | |
1083 | list_del_init(&gh->gh_list); | |
b3b94faa DT |
1084 | spin_unlock(&gl->gl_spin); |
1085 | } | |
1086 | } | |
1087 | ||
1088 | spin_lock(&gl->gl_spin); | |
1089 | gl->gl_req_gh = NULL; | |
1090 | gl->gl_req_bh = NULL; | |
1091 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
1092 | run_queue(gl); |
1093 | spin_unlock(&gl->gl_spin); | |
1094 | } | |
1095 | ||
1096 | return gh->gh_error; | |
1097 | } | |
1098 | ||
1099 | static inline struct gfs2_holder * | |
1100 | find_holder_by_owner(struct list_head *head, struct task_struct *owner) | |
1101 | { | |
1102 | struct gfs2_holder *gh; | |
1103 | ||
1104 | list_for_each_entry(gh, head, gh_list) { | |
1105 | if (gh->gh_owner == owner) | |
1106 | return gh; | |
1107 | } | |
1108 | ||
1109 | return NULL; | |
1110 | } | |
1111 | ||
b3b94faa DT |
1112 | /** |
1113 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1114 | * @gh: the holder structure to add | |
1115 | * | |
1116 | */ | |
1117 | ||
1118 | static void add_to_queue(struct gfs2_holder *gh) | |
1119 | { | |
1120 | struct gfs2_glock *gl = gh->gh_gl; | |
1121 | struct gfs2_holder *existing; | |
1122 | ||
190562bd | 1123 | BUG_ON(!gh->gh_owner); |
fee852e3 SW |
1124 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
1125 | BUG(); | |
190562bd | 1126 | |
b3b94faa DT |
1127 | existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner); |
1128 | if (existing) { | |
5965b1f4 | 1129 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
86384605 | 1130 | printk(KERN_INFO "pid : %d\n", existing->gh_owner->pid); |
907b9bce | 1131 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1132 | existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state); |
5965b1f4 | 1133 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); |
86384605 | 1134 | printk(KERN_INFO "pid : %d\n", gh->gh_owner->pid); |
907b9bce | 1135 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
86384605 | 1136 | gl->gl_name.ln_type, gl->gl_state); |
5965b1f4 | 1137 | BUG(); |
b3b94faa DT |
1138 | } |
1139 | ||
1140 | existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner); | |
1141 | if (existing) { | |
5965b1f4 SW |
1142 | print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip); |
1143 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1144 | BUG(); | |
b3b94faa DT |
1145 | } |
1146 | ||
b3b94faa DT |
1147 | if (gh->gh_flags & LM_FLAG_PRIORITY) |
1148 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1149 | else | |
907b9bce | 1150 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); |
b3b94faa DT |
1151 | } |
1152 | ||
1153 | /** | |
1154 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1155 | * @gh: the holder structure | |
1156 | * | |
1157 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1158 | * | |
1159 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1160 | */ | |
1161 | ||
1162 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1163 | { | |
1164 | struct gfs2_glock *gl = gh->gh_gl; | |
1165 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1166 | int error = 0; | |
1167 | ||
320dd101 | 1168 | restart: |
b3b94faa DT |
1169 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
1170 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1171 | return -EIO; | |
1172 | } | |
1173 | ||
1174 | set_bit(HIF_PROMOTE, &gh->gh_iflags); | |
1175 | ||
1176 | spin_lock(&gl->gl_spin); | |
1177 | add_to_queue(gh); | |
1178 | run_queue(gl); | |
1179 | spin_unlock(&gl->gl_spin); | |
1180 | ||
1181 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1182 | error = glock_wait_internal(gh); | |
1183 | if (error == GLR_CANCELED) { | |
190562bd | 1184 | msleep(100); |
b3b94faa DT |
1185 | goto restart; |
1186 | } | |
1187 | } | |
1188 | ||
b3b94faa DT |
1189 | return error; |
1190 | } | |
1191 | ||
1192 | /** | |
1193 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1194 | * @gh: the holder | |
1195 | * | |
1196 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1197 | */ | |
1198 | ||
1199 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1200 | { | |
1201 | struct gfs2_glock *gl = gh->gh_gl; | |
1202 | int ready = 0; | |
1203 | ||
1204 | spin_lock(&gl->gl_spin); | |
1205 | ||
1206 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1207 | ready = 1; | |
1208 | else if (list_empty(&gh->gh_list)) { | |
1209 | if (gh->gh_error == GLR_CANCELED) { | |
1210 | spin_unlock(&gl->gl_spin); | |
190562bd | 1211 | msleep(100); |
b3b94faa DT |
1212 | if (gfs2_glock_nq(gh)) |
1213 | return 1; | |
1214 | return 0; | |
1215 | } else | |
1216 | ready = 1; | |
1217 | } | |
1218 | ||
1219 | spin_unlock(&gl->gl_spin); | |
1220 | ||
1221 | return ready; | |
1222 | } | |
1223 | ||
1224 | /** | |
1225 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1226 | * @gh: the holder structure | |
1227 | * | |
1228 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1229 | */ | |
1230 | ||
1231 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1232 | { | |
1233 | int error; | |
1234 | ||
1235 | error = glock_wait_internal(gh); | |
1236 | if (error == GLR_CANCELED) { | |
190562bd | 1237 | msleep(100); |
b3b94faa DT |
1238 | gh->gh_flags &= ~GL_ASYNC; |
1239 | error = gfs2_glock_nq(gh); | |
1240 | } | |
1241 | ||
1242 | return error; | |
1243 | } | |
1244 | ||
1245 | /** | |
1246 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1247 | * @gh: the glock holder | |
1248 | * | |
1249 | */ | |
1250 | ||
1251 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1252 | { | |
1253 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1254 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa | 1255 | |
b3b94faa DT |
1256 | if (gh->gh_flags & GL_NOCACHE) |
1257 | handle_callback(gl, LM_ST_UNLOCKED); | |
1258 | ||
1259 | gfs2_glmutex_lock(gl); | |
1260 | ||
1261 | spin_lock(&gl->gl_spin); | |
1262 | list_del_init(&gh->gh_list); | |
1263 | ||
1264 | if (list_empty(&gl->gl_holders)) { | |
1265 | spin_unlock(&gl->gl_spin); | |
1266 | ||
1267 | if (glops->go_unlock) | |
1268 | glops->go_unlock(gh); | |
1269 | ||
b3b94faa DT |
1270 | gl->gl_stamp = jiffies; |
1271 | ||
1272 | spin_lock(&gl->gl_spin); | |
1273 | } | |
1274 | ||
1275 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1276 | run_queue(gl); | |
1277 | spin_unlock(&gl->gl_spin); | |
1278 | } | |
1279 | ||
b3b94faa DT |
1280 | /** |
1281 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1282 | * @gh: the holder structure | |
1283 | * | |
1284 | */ | |
1285 | ||
1286 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1287 | { | |
1288 | gfs2_glock_dq(gh); | |
1289 | gfs2_holder_uninit(gh); | |
1290 | } | |
1291 | ||
1292 | /** | |
1293 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1294 | * @sdp: the filesystem | |
1295 | * @number: the lock number | |
1296 | * @glops: the glock operations for the type of glock | |
1297 | * @state: the state to acquire the glock in | |
1298 | * @flags: modifier flags for the aquisition | |
1299 | * @gh: the struct gfs2_holder | |
1300 | * | |
1301 | * Returns: errno | |
1302 | */ | |
1303 | ||
cd915493 | 1304 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1305 | const struct gfs2_glock_operations *glops, |
1306 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1307 | { |
1308 | struct gfs2_glock *gl; | |
1309 | int error; | |
1310 | ||
1311 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1312 | if (!error) { | |
1313 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1314 | gfs2_glock_put(gl); | |
1315 | } | |
1316 | ||
1317 | return error; | |
1318 | } | |
1319 | ||
1320 | /** | |
1321 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1322 | * @arg_a: the first structure | |
1323 | * @arg_b: the second structure | |
1324 | * | |
1325 | */ | |
1326 | ||
1327 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1328 | { | |
a5e08a9e SW |
1329 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1330 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1331 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1332 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1333 | |
1334 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1335 | return 1; |
1336 | if (a->ln_number < b->ln_number) | |
1337 | return -1; | |
1c0f4872 | 1338 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1339 | return 0; |
b3b94faa DT |
1340 | } |
1341 | ||
1342 | /** | |
1343 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1344 | * @num_gh: the number of structures | |
1345 | * @ghs: an array of struct gfs2_holder structures | |
1346 | * | |
1347 | * Returns: 0 on success (all glocks acquired), | |
1348 | * errno on failure (no glocks acquired) | |
1349 | */ | |
1350 | ||
1351 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1352 | struct gfs2_holder **p) | |
1353 | { | |
1354 | unsigned int x; | |
1355 | int error = 0; | |
1356 | ||
1357 | for (x = 0; x < num_gh; x++) | |
1358 | p[x] = &ghs[x]; | |
1359 | ||
1360 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1361 | ||
1362 | for (x = 0; x < num_gh; x++) { | |
1363 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1364 | ||
1365 | error = gfs2_glock_nq(p[x]); | |
1366 | if (error) { | |
1367 | while (x--) | |
1368 | gfs2_glock_dq(p[x]); | |
1369 | break; | |
1370 | } | |
1371 | } | |
1372 | ||
1373 | return error; | |
1374 | } | |
1375 | ||
1376 | /** | |
1377 | * gfs2_glock_nq_m - acquire multiple glocks | |
1378 | * @num_gh: the number of structures | |
1379 | * @ghs: an array of struct gfs2_holder structures | |
1380 | * | |
1381 | * Figure out how big an impact this function has. Either: | |
1382 | * 1) Replace this code with code that calls gfs2_glock_prefetch() | |
1383 | * 2) Forget async stuff and just call nq_m_sync() | |
1384 | * 3) Leave it like it is | |
1385 | * | |
1386 | * Returns: 0 on success (all glocks acquired), | |
1387 | * errno on failure (no glocks acquired) | |
1388 | */ | |
1389 | ||
1390 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1391 | { | |
1392 | int *e; | |
1393 | unsigned int x; | |
1394 | int borked = 0, serious = 0; | |
1395 | int error = 0; | |
1396 | ||
1397 | if (!num_gh) | |
1398 | return 0; | |
1399 | ||
1400 | if (num_gh == 1) { | |
1401 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1402 | return gfs2_glock_nq(ghs); | |
1403 | } | |
1404 | ||
1405 | e = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL); | |
1406 | if (!e) | |
1407 | return -ENOMEM; | |
1408 | ||
1409 | for (x = 0; x < num_gh; x++) { | |
1410 | ghs[x].gh_flags |= LM_FLAG_TRY | GL_ASYNC; | |
1411 | error = gfs2_glock_nq(&ghs[x]); | |
1412 | if (error) { | |
1413 | borked = 1; | |
1414 | serious = error; | |
1415 | num_gh = x; | |
1416 | break; | |
1417 | } | |
1418 | } | |
1419 | ||
1420 | for (x = 0; x < num_gh; x++) { | |
1421 | error = e[x] = glock_wait_internal(&ghs[x]); | |
1422 | if (error) { | |
1423 | borked = 1; | |
1424 | if (error != GLR_TRYFAILED && error != GLR_CANCELED) | |
1425 | serious = error; | |
1426 | } | |
1427 | } | |
1428 | ||
1429 | if (!borked) { | |
1430 | kfree(e); | |
1431 | return 0; | |
1432 | } | |
1433 | ||
1434 | for (x = 0; x < num_gh; x++) | |
1435 | if (!e[x]) | |
1436 | gfs2_glock_dq(&ghs[x]); | |
1437 | ||
1438 | if (serious) | |
1439 | error = serious; | |
1440 | else { | |
1441 | for (x = 0; x < num_gh; x++) | |
1442 | gfs2_holder_reinit(ghs[x].gh_state, ghs[x].gh_flags, | |
1443 | &ghs[x]); | |
1444 | error = nq_m_sync(num_gh, ghs, (struct gfs2_holder **)e); | |
1445 | } | |
1446 | ||
1447 | kfree(e); | |
1448 | ||
1449 | return error; | |
1450 | } | |
1451 | ||
1452 | /** | |
1453 | * gfs2_glock_dq_m - release multiple glocks | |
1454 | * @num_gh: the number of structures | |
1455 | * @ghs: an array of struct gfs2_holder structures | |
1456 | * | |
1457 | */ | |
1458 | ||
1459 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1460 | { | |
1461 | unsigned int x; | |
1462 | ||
1463 | for (x = 0; x < num_gh; x++) | |
1464 | gfs2_glock_dq(&ghs[x]); | |
1465 | } | |
1466 | ||
1467 | /** | |
1468 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1469 | * @num_gh: the number of structures | |
1470 | * @ghs: an array of struct gfs2_holder structures | |
1471 | * | |
1472 | */ | |
1473 | ||
1474 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1475 | { | |
1476 | unsigned int x; | |
1477 | ||
1478 | for (x = 0; x < num_gh; x++) | |
1479 | gfs2_glock_dq_uninit(&ghs[x]); | |
1480 | } | |
1481 | ||
b3b94faa DT |
1482 | /** |
1483 | * gfs2_lvb_hold - attach a LVB from a glock | |
1484 | * @gl: The glock in question | |
1485 | * | |
1486 | */ | |
1487 | ||
1488 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1489 | { | |
1490 | int error; | |
1491 | ||
1492 | gfs2_glmutex_lock(gl); | |
1493 | ||
1494 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1495 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1496 | if (error) { | |
1497 | gfs2_glmutex_unlock(gl); | |
1498 | return error; | |
1499 | } | |
1500 | gfs2_glock_hold(gl); | |
1501 | } | |
1502 | atomic_inc(&gl->gl_lvb_count); | |
1503 | ||
1504 | gfs2_glmutex_unlock(gl); | |
1505 | ||
1506 | return 0; | |
1507 | } | |
1508 | ||
1509 | /** | |
1510 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1511 | * @gl: The glock in question | |
1512 | * | |
1513 | */ | |
1514 | ||
1515 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1516 | { | |
1517 | gfs2_glock_hold(gl); | |
1518 | gfs2_glmutex_lock(gl); | |
1519 | ||
1520 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1521 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1522 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1523 | gl->gl_lvb = NULL; | |
1524 | gfs2_glock_put(gl); | |
1525 | } | |
1526 | ||
1527 | gfs2_glmutex_unlock(gl); | |
1528 | gfs2_glock_put(gl); | |
1529 | } | |
1530 | ||
b3b94faa DT |
1531 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1532 | unsigned int state) | |
1533 | { | |
1534 | struct gfs2_glock *gl; | |
1535 | ||
1536 | gl = gfs2_glock_find(sdp, name); | |
1537 | if (!gl) | |
1538 | return; | |
1539 | ||
b3b94faa DT |
1540 | handle_callback(gl, state); |
1541 | ||
1542 | spin_lock(&gl->gl_spin); | |
1543 | run_queue(gl); | |
1544 | spin_unlock(&gl->gl_spin); | |
1545 | ||
1546 | gfs2_glock_put(gl); | |
1547 | } | |
1548 | ||
1549 | /** | |
1550 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1551 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1552 | * @type: Type of callback |
1553 | * @data: Type dependent data pointer | |
1554 | * | |
1555 | * Called by the locking module when it wants to tell us something. | |
1556 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1557 | * a journal from another client needs to be recovered. | |
1558 | */ | |
1559 | ||
9b47c11d | 1560 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1561 | { |
9b47c11d | 1562 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1563 | |
b3b94faa DT |
1564 | switch (type) { |
1565 | case LM_CB_NEED_E: | |
e7f5c01c | 1566 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1567 | return; |
1568 | ||
1569 | case LM_CB_NEED_D: | |
e7f5c01c | 1570 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1571 | return; |
1572 | ||
1573 | case LM_CB_NEED_S: | |
e7f5c01c | 1574 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1575 | return; |
1576 | ||
1577 | case LM_CB_ASYNC: { | |
e7f5c01c | 1578 | struct lm_async_cb *async = data; |
b3b94faa DT |
1579 | struct gfs2_glock *gl; |
1580 | ||
61be084e | 1581 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1582 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1583 | if (gfs2_assert_warn(sdp, gl)) | |
1584 | return; | |
1585 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1586 | gl->gl_req_bh(gl, async->lc_ret); | |
1587 | gfs2_glock_put(gl); | |
61be084e | 1588 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1589 | return; |
1590 | } | |
1591 | ||
1592 | case LM_CB_NEED_RECOVERY: | |
1593 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1594 | if (sdp->sd_recoverd_process) | |
1595 | wake_up_process(sdp->sd_recoverd_process); | |
1596 | return; | |
1597 | ||
1598 | case LM_CB_DROPLOCKS: | |
1599 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1600 | gfs2_quota_scan(sdp); | |
1601 | return; | |
1602 | ||
1603 | default: | |
1604 | gfs2_assert_warn(sdp, 0); | |
1605 | return; | |
1606 | } | |
1607 | } | |
1608 | ||
b3b94faa DT |
1609 | /** |
1610 | * demote_ok - Check to see if it's ok to unlock a glock | |
1611 | * @gl: the glock | |
1612 | * | |
1613 | * Returns: 1 if it's ok | |
1614 | */ | |
1615 | ||
1616 | static int demote_ok(struct gfs2_glock *gl) | |
1617 | { | |
8fb4b536 | 1618 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1619 | int demote = 1; |
1620 | ||
1621 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1622 | demote = 0; | |
b3b94faa DT |
1623 | else if (glops->go_demote_ok) |
1624 | demote = glops->go_demote_ok(gl); | |
1625 | ||
1626 | return demote; | |
1627 | } | |
1628 | ||
1629 | /** | |
1630 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1631 | * @gl: the glock | |
1632 | * | |
1633 | */ | |
1634 | ||
1635 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1636 | { | |
1637 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1638 | ||
1639 | spin_lock(&sdp->sd_reclaim_lock); | |
1640 | if (list_empty(&gl->gl_reclaim)) { | |
1641 | gfs2_glock_hold(gl); | |
1642 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1643 | atomic_inc(&sdp->sd_reclaim_count); | |
1644 | } | |
1645 | spin_unlock(&sdp->sd_reclaim_lock); | |
1646 | ||
1647 | wake_up(&sdp->sd_reclaim_wq); | |
1648 | } | |
1649 | ||
1650 | /** | |
1651 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1652 | * @sdp: the filesystem | |
1653 | * | |
1654 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1655 | * different glock and we notice that there are a lot of glocks in the | |
1656 | * reclaim list. | |
1657 | * | |
1658 | */ | |
1659 | ||
1660 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1661 | { | |
1662 | struct gfs2_glock *gl; | |
1663 | ||
1664 | spin_lock(&sdp->sd_reclaim_lock); | |
1665 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1666 | spin_unlock(&sdp->sd_reclaim_lock); | |
1667 | return; | |
1668 | } | |
1669 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1670 | struct gfs2_glock, gl_reclaim); | |
1671 | list_del_init(&gl->gl_reclaim); | |
1672 | spin_unlock(&sdp->sd_reclaim_lock); | |
1673 | ||
1674 | atomic_dec(&sdp->sd_reclaim_count); | |
1675 | atomic_inc(&sdp->sd_reclaimed); | |
1676 | ||
1677 | if (gfs2_glmutex_trylock(gl)) { | |
12132933 | 1678 | if (list_empty(&gl->gl_holders) && |
50299965 | 1679 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa DT |
1680 | handle_callback(gl, LM_ST_UNLOCKED); |
1681 | gfs2_glmutex_unlock(gl); | |
1682 | } | |
1683 | ||
1684 | gfs2_glock_put(gl); | |
1685 | } | |
1686 | ||
1687 | /** | |
1688 | * examine_bucket - Call a function for glock in a hash bucket | |
1689 | * @examiner: the function | |
1690 | * @sdp: the filesystem | |
1691 | * @bucket: the bucket | |
1692 | * | |
1693 | * Returns: 1 if the bucket has entries | |
1694 | */ | |
1695 | ||
1696 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1697 | unsigned int hash) |
b3b94faa | 1698 | { |
24264434 SW |
1699 | struct gfs2_glock *gl, *prev = NULL; |
1700 | int has_entries = 0; | |
b6397893 | 1701 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1702 | |
24264434 | 1703 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1704 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1705 | if (hlist_empty(head)) | |
24264434 | 1706 | goto out; |
b6397893 SW |
1707 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1708 | while(1) { | |
24264434 | 1709 | if (gl->gl_sbd == sdp) { |
b3b94faa | 1710 | gfs2_glock_hold(gl); |
24264434 SW |
1711 | read_unlock(gl_lock_addr(hash)); |
1712 | if (prev) | |
1713 | gfs2_glock_put(prev); | |
1714 | prev = gl; | |
1715 | examiner(gl); | |
a8336344 | 1716 | has_entries = 1; |
24264434 | 1717 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1718 | } |
b6397893 SW |
1719 | if (gl->gl_list.next == NULL) |
1720 | break; | |
24264434 | 1721 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1722 | } |
24264434 SW |
1723 | out: |
1724 | read_unlock(gl_lock_addr(hash)); | |
1725 | if (prev) | |
1726 | gfs2_glock_put(prev); | |
1727 | return has_entries; | |
b3b94faa DT |
1728 | } |
1729 | ||
1730 | /** | |
1731 | * scan_glock - look at a glock and see if we can reclaim it | |
1732 | * @gl: the glock to look at | |
1733 | * | |
1734 | */ | |
1735 | ||
1736 | static void scan_glock(struct gfs2_glock *gl) | |
1737 | { | |
b004157a | 1738 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1739 | return; |
a2242db0 | 1740 | |
b3b94faa | 1741 | if (gfs2_glmutex_trylock(gl)) { |
12132933 | 1742 | if (list_empty(&gl->gl_holders) && |
24264434 | 1743 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa | 1744 | goto out_schedule; |
b3b94faa DT |
1745 | gfs2_glmutex_unlock(gl); |
1746 | } | |
b3b94faa DT |
1747 | return; |
1748 | ||
627add2d | 1749 | out_schedule: |
b3b94faa DT |
1750 | gfs2_glmutex_unlock(gl); |
1751 | gfs2_glock_schedule_for_reclaim(gl); | |
b3b94faa DT |
1752 | } |
1753 | ||
1754 | /** | |
1755 | * gfs2_scand_internal - Look for glocks and inodes to toss from memory | |
1756 | * @sdp: the filesystem | |
1757 | * | |
1758 | */ | |
1759 | ||
1760 | void gfs2_scand_internal(struct gfs2_sbd *sdp) | |
1761 | { | |
1762 | unsigned int x; | |
1763 | ||
94610610 | 1764 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) |
37b2fa6a | 1765 | examine_bucket(scan_glock, sdp, x); |
b3b94faa DT |
1766 | } |
1767 | ||
1768 | /** | |
1769 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1770 | * @gl: the glock to look at | |
1771 | * | |
1772 | */ | |
1773 | ||
1774 | static void clear_glock(struct gfs2_glock *gl) | |
1775 | { | |
1776 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1777 | int released; | |
1778 | ||
1779 | spin_lock(&sdp->sd_reclaim_lock); | |
1780 | if (!list_empty(&gl->gl_reclaim)) { | |
1781 | list_del_init(&gl->gl_reclaim); | |
1782 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1783 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1784 | released = gfs2_glock_put(gl); |
1785 | gfs2_assert(sdp, !released); | |
190562bd SW |
1786 | } else { |
1787 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1788 | } |
b3b94faa DT |
1789 | |
1790 | if (gfs2_glmutex_trylock(gl)) { | |
90101c31 | 1791 | if (list_empty(&gl->gl_holders) && |
b3b94faa DT |
1792 | gl->gl_state != LM_ST_UNLOCKED) |
1793 | handle_callback(gl, LM_ST_UNLOCKED); | |
b3b94faa DT |
1794 | gfs2_glmutex_unlock(gl); |
1795 | } | |
b3b94faa DT |
1796 | } |
1797 | ||
1798 | /** | |
1799 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1800 | * @sdp: the filesystem | |
1801 | * @wait: wait until it's all gone | |
1802 | * | |
1803 | * Called when unmounting the filesystem, or when inter-node lock manager | |
1804 | * requests DROPLOCKS because it is running out of capacity. | |
1805 | */ | |
1806 | ||
1807 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
1808 | { | |
1809 | unsigned long t; | |
1810 | unsigned int x; | |
1811 | int cont; | |
1812 | ||
1813 | t = jiffies; | |
1814 | ||
1815 | for (;;) { | |
1816 | cont = 0; | |
24264434 | 1817 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1818 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1819 | cont = 1; |
24264434 | 1820 | } |
b3b94faa DT |
1821 | |
1822 | if (!wait || !cont) | |
1823 | break; | |
1824 | ||
1825 | if (time_after_eq(jiffies, | |
1826 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1827 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1828 | "Dumping lock state...\n"); | |
1829 | gfs2_dump_lockstate(sdp); | |
1830 | t = jiffies; | |
1831 | } | |
1832 | ||
61be084e | 1833 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1834 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1835 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1836 | msleep(10); |
b3b94faa DT |
1837 | } |
1838 | } | |
1839 | ||
1840 | /* | |
1841 | * Diagnostic routines to help debug distributed deadlock | |
1842 | */ | |
1843 | ||
1844 | /** | |
1845 | * dump_holder - print information about a glock holder | |
1846 | * @str: a string naming the type of holder | |
1847 | * @gh: the glock holder | |
1848 | * | |
1849 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1850 | */ | |
1851 | ||
1852 | static int dump_holder(char *str, struct gfs2_holder *gh) | |
1853 | { | |
1854 | unsigned int x; | |
1855 | int error = -ENOBUFS; | |
1856 | ||
d92a8d48 SW |
1857 | printk(KERN_INFO " %s\n", str); |
1858 | printk(KERN_INFO " owner = %ld\n", | |
b3b94faa | 1859 | (gh->gh_owner) ? (long)gh->gh_owner->pid : -1); |
d92a8d48 SW |
1860 | printk(KERN_INFO " gh_state = %u\n", gh->gh_state); |
1861 | printk(KERN_INFO " gh_flags ="); | |
b3b94faa DT |
1862 | for (x = 0; x < 32; x++) |
1863 | if (gh->gh_flags & (1 << x)) | |
1864 | printk(" %u", x); | |
1865 | printk(" \n"); | |
d92a8d48 SW |
1866 | printk(KERN_INFO " error = %d\n", gh->gh_error); |
1867 | printk(KERN_INFO " gh_iflags ="); | |
b3b94faa DT |
1868 | for (x = 0; x < 32; x++) |
1869 | if (test_bit(x, &gh->gh_iflags)) | |
1870 | printk(" %u", x); | |
1871 | printk(" \n"); | |
d0dc80db | 1872 | print_symbol(KERN_INFO " initialized at: %s\n", gh->gh_ip); |
b3b94faa DT |
1873 | |
1874 | error = 0; | |
1875 | ||
1876 | return error; | |
1877 | } | |
1878 | ||
1879 | /** | |
1880 | * dump_inode - print information about an inode | |
1881 | * @ip: the inode | |
1882 | * | |
1883 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1884 | */ | |
1885 | ||
1886 | static int dump_inode(struct gfs2_inode *ip) | |
1887 | { | |
1888 | unsigned int x; | |
1889 | int error = -ENOBUFS; | |
1890 | ||
d92a8d48 SW |
1891 | printk(KERN_INFO " Inode:\n"); |
1892 | printk(KERN_INFO " num = %llu %llu\n", | |
382066da SW |
1893 | (unsigned long long)ip->i_num.no_formal_ino, |
1894 | (unsigned long long)ip->i_num.no_addr); | |
b60623c2 | 1895 | printk(KERN_INFO " type = %u\n", IF2DT(ip->i_inode.i_mode)); |
d92a8d48 | 1896 | printk(KERN_INFO " i_flags ="); |
b3b94faa DT |
1897 | for (x = 0; x < 32; x++) |
1898 | if (test_bit(x, &ip->i_flags)) | |
1899 | printk(" %u", x); | |
1900 | printk(" \n"); | |
b3b94faa DT |
1901 | |
1902 | error = 0; | |
1903 | ||
1904 | return error; | |
1905 | } | |
1906 | ||
1907 | /** | |
1908 | * dump_glock - print information about a glock | |
1909 | * @gl: the glock | |
1910 | * @count: where we are in the buffer | |
1911 | * | |
1912 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1913 | */ | |
1914 | ||
1915 | static int dump_glock(struct gfs2_glock *gl) | |
1916 | { | |
1917 | struct gfs2_holder *gh; | |
1918 | unsigned int x; | |
1919 | int error = -ENOBUFS; | |
1920 | ||
1921 | spin_lock(&gl->gl_spin); | |
1922 | ||
85d1da67 | 1923 | printk(KERN_INFO "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type, |
382066da | 1924 | (unsigned long long)gl->gl_name.ln_number); |
d92a8d48 | 1925 | printk(KERN_INFO " gl_flags ="); |
85d1da67 | 1926 | for (x = 0; x < 32; x++) { |
b3b94faa DT |
1927 | if (test_bit(x, &gl->gl_flags)) |
1928 | printk(" %u", x); | |
85d1da67 | 1929 | } |
b3b94faa | 1930 | printk(" \n"); |
16feb9fe | 1931 | printk(KERN_INFO " gl_ref = %d\n", atomic_read(&gl->gl_ref)); |
d92a8d48 | 1932 | printk(KERN_INFO " gl_state = %u\n", gl->gl_state); |
320dd101 SW |
1933 | printk(KERN_INFO " gl_owner = %s\n", gl->gl_owner->comm); |
1934 | print_symbol(KERN_INFO " gl_ip = %s\n", gl->gl_ip); | |
d92a8d48 SW |
1935 | printk(KERN_INFO " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); |
1936 | printk(KERN_INFO " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
1937 | printk(KERN_INFO " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
1938 | printk(KERN_INFO " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
1939 | printk(KERN_INFO " le = %s\n", | |
b3b94faa | 1940 | (list_empty(&gl->gl_le.le_list)) ? "no" : "yes"); |
d92a8d48 | 1941 | printk(KERN_INFO " reclaim = %s\n", |
b3b94faa DT |
1942 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); |
1943 | if (gl->gl_aspace) | |
85d1da67 | 1944 | printk(KERN_INFO " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, |
88721877 | 1945 | gl->gl_aspace->i_mapping->nrpages); |
b3b94faa | 1946 | else |
d92a8d48 SW |
1947 | printk(KERN_INFO " aspace = no\n"); |
1948 | printk(KERN_INFO " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa DT |
1949 | if (gl->gl_req_gh) { |
1950 | error = dump_holder("Request", gl->gl_req_gh); | |
1951 | if (error) | |
1952 | goto out; | |
1953 | } | |
1954 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
1955 | error = dump_holder("Holder", gh); | |
1956 | if (error) | |
1957 | goto out; | |
1958 | } | |
1959 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
1960 | error = dump_holder("Waiter1", gh); | |
1961 | if (error) | |
1962 | goto out; | |
1963 | } | |
1964 | list_for_each_entry(gh, &gl->gl_waiters2, gh_list) { | |
1965 | error = dump_holder("Waiter2", gh); | |
1966 | if (error) | |
1967 | goto out; | |
1968 | } | |
1969 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { | |
1970 | error = dump_holder("Waiter3", gh); | |
1971 | if (error) | |
1972 | goto out; | |
1973 | } | |
5c676f6d | 1974 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa DT |
1975 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
1976 | list_empty(&gl->gl_holders)) { | |
5c676f6d | 1977 | error = dump_inode(gl->gl_object); |
b3b94faa DT |
1978 | if (error) |
1979 | goto out; | |
1980 | } else { | |
1981 | error = -ENOBUFS; | |
d92a8d48 | 1982 | printk(KERN_INFO " Inode: busy\n"); |
b3b94faa DT |
1983 | } |
1984 | } | |
1985 | ||
1986 | error = 0; | |
1987 | ||
a91ea69f | 1988 | out: |
b3b94faa | 1989 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
1990 | return error; |
1991 | } | |
1992 | ||
1993 | /** | |
1994 | * gfs2_dump_lockstate - print out the current lockstate | |
1995 | * @sdp: the filesystem | |
1996 | * @ub: the buffer to copy the information into | |
1997 | * | |
1998 | * If @ub is NULL, dump the lockstate to the console. | |
1999 | * | |
2000 | */ | |
2001 | ||
08bc2dbc | 2002 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 2003 | { |
b3b94faa | 2004 | struct gfs2_glock *gl; |
b6397893 | 2005 | struct hlist_node *h; |
b3b94faa DT |
2006 | unsigned int x; |
2007 | int error = 0; | |
2008 | ||
2009 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 2010 | |
087efdd3 | 2011 | read_lock(gl_lock_addr(x)); |
b3b94faa | 2012 | |
b6397893 | 2013 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
2014 | if (gl->gl_sbd != sdp) |
2015 | continue; | |
b3b94faa DT |
2016 | |
2017 | error = dump_glock(gl); | |
2018 | if (error) | |
2019 | break; | |
2020 | } | |
2021 | ||
087efdd3 | 2022 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
2023 | |
2024 | if (error) | |
2025 | break; | |
2026 | } | |
2027 | ||
2028 | ||
2029 | return error; | |
2030 | } | |
2031 | ||
85d1da67 SW |
2032 | int __init gfs2_glock_init(void) |
2033 | { | |
2034 | unsigned i; | |
2035 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 2036 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 2037 | } |
087efdd3 SW |
2038 | #ifdef GL_HASH_LOCK_SZ |
2039 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
2040 | rwlock_init(&gl_hash_locks[i]); | |
2041 | } | |
2042 | #endif | |
85d1da67 SW |
2043 | return 0; |
2044 | } | |
2045 |