Commit | Line | Data |
---|---|---|
b3b94faa DT |
1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
398bbe68 | 3 | * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. |
b3b94faa DT |
4 | * |
5 | * This copyrighted material is made available to anyone wishing to use, | |
6 | * modify, copy, or redistribute it subject to the terms and conditions | |
e9fc2aa0 | 7 | * of the GNU General Public License version 2. |
b3b94faa DT |
8 | */ |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/sort.h> | |
17 | #include <linux/jhash.h> | |
d0dc80db | 18 | #include <linux/kallsyms.h> |
5c676f6d | 19 | #include <linux/gfs2_ondisk.h> |
24264434 | 20 | #include <linux/list.h> |
7d308590 | 21 | #include <linux/lm_interface.h> |
fee852e3 | 22 | #include <linux/wait.h> |
95d97b7d | 23 | #include <linux/module.h> |
61be084e | 24 | #include <linux/rwsem.h> |
b3b94faa | 25 | #include <asm/uaccess.h> |
7c52b166 RP |
26 | #include <linux/seq_file.h> |
27 | #include <linux/debugfs.h> | |
8fbbfd21 SW |
28 | #include <linux/kthread.h> |
29 | #include <linux/freezer.h> | |
c4f68a13 BM |
30 | #include <linux/workqueue.h> |
31 | #include <linux/jiffies.h> | |
b3b94faa DT |
32 | |
33 | #include "gfs2.h" | |
5c676f6d | 34 | #include "incore.h" |
b3b94faa DT |
35 | #include "glock.h" |
36 | #include "glops.h" | |
37 | #include "inode.h" | |
38 | #include "lm.h" | |
39 | #include "lops.h" | |
40 | #include "meta_io.h" | |
41 | #include "quota.h" | |
42 | #include "super.h" | |
5c676f6d | 43 | #include "util.h" |
b3b94faa | 44 | |
37b2fa6a | 45 | struct gfs2_gl_hash_bucket { |
b6397893 | 46 | struct hlist_head hb_list; |
37b2fa6a SW |
47 | }; |
48 | ||
7c52b166 RP |
49 | struct glock_iter { |
50 | int hash; /* hash bucket index */ | |
51 | struct gfs2_sbd *sdp; /* incore superblock */ | |
52 | struct gfs2_glock *gl; /* current glock struct */ | |
7c52b166 RP |
53 | struct seq_file *seq; /* sequence file for debugfs */ |
54 | char string[512]; /* scratch space */ | |
55 | }; | |
56 | ||
b3b94faa DT |
57 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
58 | ||
08bc2dbc | 59 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); |
04b933f2 | 60 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl); |
3b8249f6 | 61 | static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh); |
b5d32bea | 62 | static void gfs2_glock_drop_th(struct gfs2_glock *gl); |
c4f68a13 BM |
63 | static void run_queue(struct gfs2_glock *gl); |
64 | ||
61be084e | 65 | static DECLARE_RWSEM(gfs2_umount_flush_sem); |
7c52b166 | 66 | static struct dentry *gfs2_root; |
8fbbfd21 SW |
67 | static struct task_struct *scand_process; |
68 | static unsigned int scand_secs = 5; | |
c4f68a13 | 69 | static struct workqueue_struct *glock_workqueue; |
08bc2dbc | 70 | |
b6397893 | 71 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
72 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
73 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
74 | ||
85d1da67 | 75 | static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 76 | static struct dentry *gfs2_root; |
087efdd3 SW |
77 | |
78 | /* | |
79 | * Despite what you might think, the numbers below are not arbitrary :-) | |
80 | * They are taken from the ipv4 routing hash code, which is well tested | |
81 | * and thus should be nearly optimal. Later on we might tweek the numbers | |
82 | * but for now this should be fine. | |
83 | * | |
84 | * The reason for putting the locks in a separate array from the list heads | |
85 | * is that we can have fewer locks than list heads and save memory. We use | |
86 | * the same hash function for both, but with a different hash mask. | |
87 | */ | |
88 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ | |
89 | defined(CONFIG_PROVE_LOCKING) | |
90 | ||
91 | #ifdef CONFIG_LOCKDEP | |
92 | # define GL_HASH_LOCK_SZ 256 | |
93 | #else | |
94 | # if NR_CPUS >= 32 | |
95 | # define GL_HASH_LOCK_SZ 4096 | |
96 | # elif NR_CPUS >= 16 | |
97 | # define GL_HASH_LOCK_SZ 2048 | |
98 | # elif NR_CPUS >= 8 | |
99 | # define GL_HASH_LOCK_SZ 1024 | |
100 | # elif NR_CPUS >= 4 | |
101 | # define GL_HASH_LOCK_SZ 512 | |
102 | # else | |
103 | # define GL_HASH_LOCK_SZ 256 | |
104 | # endif | |
105 | #endif | |
106 | ||
107 | /* We never want more locks than chains */ | |
108 | #if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ | |
109 | # undef GL_HASH_LOCK_SZ | |
110 | # define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE | |
111 | #endif | |
112 | ||
113 | static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; | |
114 | ||
115 | static inline rwlock_t *gl_lock_addr(unsigned int x) | |
116 | { | |
94610610 | 117 | return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; |
087efdd3 SW |
118 | } |
119 | #else /* not SMP, so no spinlocks required */ | |
0ac23069 | 120 | static inline rwlock_t *gl_lock_addr(unsigned int x) |
087efdd3 SW |
121 | { |
122 | return NULL; | |
123 | } | |
124 | #endif | |
85d1da67 | 125 | |
b3b94faa DT |
126 | /** |
127 | * relaxed_state_ok - is a requested lock compatible with the current lock mode? | |
128 | * @actual: the current state of the lock | |
129 | * @requested: the lock state that was requested by the caller | |
130 | * @flags: the modifier flags passed in by the caller | |
131 | * | |
132 | * Returns: 1 if the locks are compatible, 0 otherwise | |
133 | */ | |
134 | ||
135 | static inline int relaxed_state_ok(unsigned int actual, unsigned requested, | |
136 | int flags) | |
137 | { | |
138 | if (actual == requested) | |
139 | return 1; | |
140 | ||
141 | if (flags & GL_EXACT) | |
142 | return 0; | |
143 | ||
144 | if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) | |
145 | return 1; | |
146 | ||
147 | if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) | |
148 | return 1; | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
153 | /** | |
154 | * gl_hash() - Turn glock number into hash bucket number | |
155 | * @lock: The glock number | |
156 | * | |
157 | * Returns: The number of the corresponding hash bucket | |
158 | */ | |
159 | ||
b8547856 SW |
160 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
161 | const struct lm_lockname *name) | |
b3b94faa DT |
162 | { |
163 | unsigned int h; | |
164 | ||
cd915493 | 165 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 166 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 167 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
168 | h &= GFS2_GL_HASH_MASK; |
169 | ||
170 | return h; | |
171 | } | |
172 | ||
173 | /** | |
174 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
175 | * @gl: The glock to release | |
176 | * | |
177 | * Also calls lock module to release its internal structure for this glock. | |
178 | * | |
179 | */ | |
180 | ||
181 | static void glock_free(struct gfs2_glock *gl) | |
182 | { | |
183 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
184 | struct inode *aspace = gl->gl_aspace; | |
185 | ||
186 | gfs2_lm_put_lock(sdp, gl->gl_lock); | |
187 | ||
188 | if (aspace) | |
189 | gfs2_aspace_put(aspace); | |
190 | ||
191 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
192 | } |
193 | ||
194 | /** | |
195 | * gfs2_glock_hold() - increment reference count on glock | |
196 | * @gl: The glock to hold | |
197 | * | |
198 | */ | |
199 | ||
200 | void gfs2_glock_hold(struct gfs2_glock *gl) | |
201 | { | |
16feb9fe | 202 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
203 | } |
204 | ||
205 | /** | |
206 | * gfs2_glock_put() - Decrement reference count on glock | |
207 | * @gl: The glock to put | |
208 | * | |
209 | */ | |
210 | ||
211 | int gfs2_glock_put(struct gfs2_glock *gl) | |
212 | { | |
b3b94faa | 213 | int rv = 0; |
16feb9fe | 214 | struct gfs2_sbd *sdp = gl->gl_sbd; |
b3b94faa | 215 | |
087efdd3 | 216 | write_lock(gl_lock_addr(gl->gl_hash)); |
16feb9fe | 217 | if (atomic_dec_and_test(&gl->gl_ref)) { |
b6397893 | 218 | hlist_del(&gl->gl_list); |
087efdd3 | 219 | write_unlock(gl_lock_addr(gl->gl_hash)); |
16feb9fe SW |
220 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); |
221 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
222 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
223 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
16feb9fe | 224 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); |
b3b94faa DT |
225 | glock_free(gl); |
226 | rv = 1; | |
227 | goto out; | |
228 | } | |
087efdd3 | 229 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 230 | out: |
b3b94faa DT |
231 | return rv; |
232 | } | |
233 | ||
b3b94faa DT |
234 | /** |
235 | * search_bucket() - Find struct gfs2_glock by lock number | |
236 | * @bucket: the bucket to search | |
237 | * @name: The lock name | |
238 | * | |
239 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
240 | */ | |
241 | ||
37b2fa6a | 242 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 243 | const struct gfs2_sbd *sdp, |
d6a53727 | 244 | const struct lm_lockname *name) |
b3b94faa DT |
245 | { |
246 | struct gfs2_glock *gl; | |
b6397893 | 247 | struct hlist_node *h; |
b3b94faa | 248 | |
b6397893 | 249 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
250 | if (!lm_name_equal(&gl->gl_name, name)) |
251 | continue; | |
899be4d3 SW |
252 | if (gl->gl_sbd != sdp) |
253 | continue; | |
b3b94faa | 254 | |
16feb9fe | 255 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
256 | |
257 | return gl; | |
258 | } | |
259 | ||
260 | return NULL; | |
261 | } | |
262 | ||
263 | /** | |
264 | * gfs2_glock_find() - Find glock by lock number | |
265 | * @sdp: The GFS2 superblock | |
266 | * @name: The lock name | |
267 | * | |
268 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
269 | */ | |
270 | ||
85d1da67 | 271 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 272 | const struct lm_lockname *name) |
b3b94faa | 273 | { |
37b2fa6a | 274 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
275 | struct gfs2_glock *gl; |
276 | ||
087efdd3 | 277 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 278 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 279 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
280 | |
281 | return gl; | |
282 | } | |
283 | ||
c4f68a13 BM |
284 | static void glock_work_func(struct work_struct *work) |
285 | { | |
286 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); | |
287 | ||
288 | spin_lock(&gl->gl_spin); | |
289 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags)) | |
290 | set_bit(GLF_DEMOTE, &gl->gl_flags); | |
291 | run_queue(gl); | |
292 | spin_unlock(&gl->gl_spin); | |
293 | gfs2_glock_put(gl); | |
294 | } | |
295 | ||
b3b94faa DT |
296 | /** |
297 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
298 | * @sdp: The GFS2 superblock | |
299 | * @number: the lock number | |
300 | * @glops: The glock_operations to use | |
301 | * @create: If 0, don't create the glock if it doesn't exist | |
302 | * @glp: the glock is returned here | |
303 | * | |
304 | * This does not lock a glock, just finds/creates structures for one. | |
305 | * | |
306 | * Returns: errno | |
307 | */ | |
308 | ||
cd915493 | 309 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 310 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
311 | struct gfs2_glock **glp) |
312 | { | |
37b2fa6a | 313 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 314 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 315 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
316 | int error; |
317 | ||
087efdd3 | 318 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 319 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 320 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
321 | |
322 | if (gl || !create) { | |
323 | *glp = gl; | |
324 | return 0; | |
325 | } | |
326 | ||
327 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
328 | if (!gl) | |
329 | return -ENOMEM; | |
330 | ||
ec45d9f5 | 331 | gl->gl_flags = 0; |
b3b94faa | 332 | gl->gl_name = name; |
16feb9fe | 333 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 334 | gl->gl_state = LM_ST_UNLOCKED; |
c4f68a13 | 335 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 336 | gl->gl_hash = hash; |
eccba068 | 337 | gl->gl_owner_pid = NULL; |
320dd101 | 338 | gl->gl_ip = 0; |
b3b94faa | 339 | gl->gl_ops = glops; |
ec45d9f5 SW |
340 | gl->gl_req_gh = NULL; |
341 | gl->gl_req_bh = NULL; | |
342 | gl->gl_vn = 0; | |
343 | gl->gl_stamp = jiffies; | |
c4f68a13 | 344 | gl->gl_tchange = jiffies; |
ec45d9f5 | 345 | gl->gl_object = NULL; |
b3b94faa | 346 | gl->gl_sbd = sdp; |
ec45d9f5 | 347 | gl->gl_aspace = NULL; |
c4f68a13 | 348 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b3b94faa DT |
349 | |
350 | /* If this glock protects actual on-disk data or metadata blocks, | |
351 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 352 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
353 | gl->gl_aspace = gfs2_aspace_get(sdp); |
354 | if (!gl->gl_aspace) { | |
355 | error = -ENOMEM; | |
356 | goto fail; | |
357 | } | |
358 | } | |
359 | ||
360 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
361 | if (error) | |
362 | goto fail_aspace; | |
363 | ||
087efdd3 | 364 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 365 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 366 | if (tmp) { |
087efdd3 | 367 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
368 | glock_free(gl); |
369 | gl = tmp; | |
370 | } else { | |
b6397893 | 371 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 372 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
373 | } |
374 | ||
375 | *glp = gl; | |
376 | ||
377 | return 0; | |
378 | ||
ec45d9f5 | 379 | fail_aspace: |
b3b94faa DT |
380 | if (gl->gl_aspace) |
381 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 382 | fail: |
907b9bce | 383 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
384 | return error; |
385 | } | |
386 | ||
387 | /** | |
388 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
389 | * @gl: the glock | |
390 | * @state: the state we're requesting | |
391 | * @flags: the modifier flags | |
392 | * @gh: the holder structure | |
393 | * | |
394 | */ | |
395 | ||
190562bd | 396 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
397 | struct gfs2_holder *gh) |
398 | { | |
399 | INIT_LIST_HEAD(&gh->gh_list); | |
400 | gh->gh_gl = gl; | |
d0dc80db | 401 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 402 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
403 | gh->gh_state = state; |
404 | gh->gh_flags = flags; | |
405 | gh->gh_error = 0; | |
406 | gh->gh_iflags = 0; | |
b3b94faa DT |
407 | gfs2_glock_hold(gl); |
408 | } | |
409 | ||
410 | /** | |
411 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
412 | * @state: the state we're requesting | |
413 | * @flags: the modifier flags | |
414 | * @gh: the holder structure | |
415 | * | |
416 | * Don't mess with the glock. | |
417 | * | |
418 | */ | |
419 | ||
190562bd | 420 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
421 | { |
422 | gh->gh_state = state; | |
579b78a4 | 423 | gh->gh_flags = flags; |
3b8249f6 | 424 | gh->gh_iflags = 0; |
d0dc80db | 425 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
426 | } |
427 | ||
428 | /** | |
429 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
430 | * @gh: the holder structure | |
431 | * | |
432 | */ | |
433 | ||
434 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
435 | { | |
b1e058da | 436 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
437 | gfs2_glock_put(gh->gh_gl); |
438 | gh->gh_gl = NULL; | |
d0dc80db | 439 | gh->gh_ip = 0; |
b3b94faa DT |
440 | } |
441 | ||
3b8249f6 | 442 | static void gfs2_holder_wake(struct gfs2_holder *gh) |
fee852e3 | 443 | { |
fee852e3 | 444 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
d93cfa98 | 445 | smp_mb__after_clear_bit(); |
fee852e3 SW |
446 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); |
447 | } | |
448 | ||
d93cfa98 | 449 | static int just_schedule(void *word) |
fee852e3 SW |
450 | { |
451 | schedule(); | |
452 | return 0; | |
453 | } | |
454 | ||
455 | static void wait_on_holder(struct gfs2_holder *gh) | |
456 | { | |
457 | might_sleep(); | |
d93cfa98 AD |
458 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE); |
459 | } | |
460 | ||
461 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
462 | { | |
c4f68a13 | 463 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
d93cfa98 AD |
464 | clear_bit(GLF_DEMOTE, &gl->gl_flags); |
465 | smp_mb__after_clear_bit(); | |
466 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
467 | } | |
468 | ||
469 | static void wait_on_demote(struct gfs2_glock *gl) | |
470 | { | |
471 | might_sleep(); | |
472 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE); | |
fee852e3 SW |
473 | } |
474 | ||
b3b94faa DT |
475 | /** |
476 | * rq_mutex - process a mutex request in the queue | |
477 | * @gh: the glock holder | |
478 | * | |
479 | * Returns: 1 if the queue is blocked | |
480 | */ | |
481 | ||
482 | static int rq_mutex(struct gfs2_holder *gh) | |
483 | { | |
484 | struct gfs2_glock *gl = gh->gh_gl; | |
485 | ||
486 | list_del_init(&gh->gh_list); | |
487 | /* gh->gh_error never examined. */ | |
488 | set_bit(GLF_LOCK, &gl->gl_flags); | |
d043e190 | 489 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
fee852e3 SW |
490 | smp_mb(); |
491 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
b3b94faa DT |
492 | |
493 | return 1; | |
494 | } | |
495 | ||
496 | /** | |
497 | * rq_promote - process a promote request in the queue | |
498 | * @gh: the glock holder | |
499 | * | |
500 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
501 | * | |
502 | * Returns: 1 if the queue is blocked | |
503 | */ | |
504 | ||
505 | static int rq_promote(struct gfs2_holder *gh) | |
506 | { | |
507 | struct gfs2_glock *gl = gh->gh_gl; | |
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); | |
3b8249f6 | 514 | gfs2_glock_xmote_th(gh->gh_gl, gh); |
b3b94faa DT |
515 | spin_lock(&gl->gl_spin); |
516 | } | |
517 | return 1; | |
518 | } | |
519 | ||
520 | if (list_empty(&gl->gl_holders)) { | |
521 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
522 | set_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
523 | } else { |
524 | struct gfs2_holder *next_gh; | |
1c0f4872 | 525 | if (gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa DT |
526 | return 1; |
527 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
528 | gh_list); | |
1c0f4872 | 529 | if (next_gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa | 530 | return 1; |
b3b94faa DT |
531 | } |
532 | ||
533 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
534 | gh->gh_error = 0; | |
535 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
536 | ||
3b8249f6 | 537 | gfs2_holder_wake(gh); |
b3b94faa DT |
538 | |
539 | return 0; | |
540 | } | |
541 | ||
542 | /** | |
543 | * rq_demote - process a demote request in the queue | |
544 | * @gh: the glock holder | |
545 | * | |
546 | * Returns: 1 if the queue is blocked | |
547 | */ | |
548 | ||
3b8249f6 | 549 | static int rq_demote(struct gfs2_glock *gl) |
b3b94faa | 550 | { |
b3b94faa DT |
551 | if (!list_empty(&gl->gl_holders)) |
552 | return 1; | |
553 | ||
3b8249f6 SW |
554 | if (gl->gl_state == gl->gl_demote_state || |
555 | gl->gl_state == LM_ST_UNLOCKED) { | |
d93cfa98 | 556 | gfs2_demote_wake(gl); |
3b8249f6 | 557 | return 0; |
b3b94faa | 558 | } |
cc7e79b1 | 559 | |
3b8249f6 | 560 | set_bit(GLF_LOCK, &gl->gl_flags); |
cc7e79b1 WC |
561 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); |
562 | ||
3b8249f6 | 563 | if (gl->gl_demote_state == LM_ST_UNLOCKED || |
87124e58 SW |
564 | gl->gl_state != LM_ST_EXCLUSIVE) { |
565 | spin_unlock(&gl->gl_spin); | |
3b8249f6 | 566 | gfs2_glock_drop_th(gl); |
87124e58 SW |
567 | } else { |
568 | spin_unlock(&gl->gl_spin); | |
3b8249f6 | 569 | gfs2_glock_xmote_th(gl, NULL); |
87124e58 | 570 | } |
cc7e79b1 | 571 | |
3b8249f6 | 572 | spin_lock(&gl->gl_spin); |
cc7e79b1 | 573 | clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); |
b3b94faa DT |
574 | |
575 | return 0; | |
576 | } | |
577 | ||
b3b94faa DT |
578 | /** |
579 | * run_queue - process holder structures on a glock | |
580 | * @gl: the glock | |
581 | * | |
582 | */ | |
b3b94faa DT |
583 | static void run_queue(struct gfs2_glock *gl) |
584 | { | |
585 | struct gfs2_holder *gh; | |
586 | int blocked = 1; | |
587 | ||
588 | for (;;) { | |
589 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
590 | break; | |
591 | ||
592 | if (!list_empty(&gl->gl_waiters1)) { | |
593 | gh = list_entry(gl->gl_waiters1.next, | |
594 | struct gfs2_holder, gh_list); | |
e589665e | 595 | blocked = rq_mutex(gh); |
3b8249f6 SW |
596 | } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
597 | blocked = rq_demote(gl); | |
cc7e79b1 WC |
598 | if (gl->gl_waiters2 && !blocked) { |
599 | set_bit(GLF_DEMOTE, &gl->gl_flags); | |
600 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
601 | } | |
602 | gl->gl_waiters2 = 0; | |
b3b94faa DT |
603 | } else if (!list_empty(&gl->gl_waiters3)) { |
604 | gh = list_entry(gl->gl_waiters3.next, | |
605 | struct gfs2_holder, gh_list); | |
e589665e | 606 | blocked = rq_promote(gh); |
b3b94faa DT |
607 | } else |
608 | break; | |
609 | ||
610 | if (blocked) | |
611 | break; | |
612 | } | |
613 | } | |
614 | ||
615 | /** | |
616 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
617 | * @gl: the glock | |
618 | * | |
619 | * Gives caller exclusive access to manipulate a glock structure. | |
620 | */ | |
621 | ||
feaa7bba | 622 | static void gfs2_glmutex_lock(struct gfs2_glock *gl) |
b3b94faa | 623 | { |
b3b94faa | 624 | spin_lock(&gl->gl_spin); |
85d1da67 | 625 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
398bbe68 BP |
626 | struct gfs2_holder gh; |
627 | ||
628 | gfs2_holder_init(gl, 0, 0, &gh); | |
629 | set_bit(HIF_WAIT, &gh.gh_iflags); | |
b3b94faa | 630 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); |
398bbe68 BP |
631 | spin_unlock(&gl->gl_spin); |
632 | wait_on_holder(&gh); | |
633 | gfs2_holder_uninit(&gh); | |
85d1da67 | 634 | } else { |
eccba068 | 635 | gl->gl_owner_pid = get_pid(task_pid(current)); |
320dd101 | 636 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
398bbe68 | 637 | spin_unlock(&gl->gl_spin); |
320dd101 | 638 | } |
b3b94faa DT |
639 | } |
640 | ||
641 | /** | |
642 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
643 | * @gl: the glock | |
644 | * | |
645 | * Returns: 1 if the glock is acquired | |
646 | */ | |
647 | ||
08bc2dbc | 648 | static int gfs2_glmutex_trylock(struct gfs2_glock *gl) |
b3b94faa DT |
649 | { |
650 | int acquired = 1; | |
651 | ||
652 | spin_lock(&gl->gl_spin); | |
85d1da67 | 653 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 654 | acquired = 0; |
85d1da67 | 655 | } else { |
eccba068 | 656 | gl->gl_owner_pid = get_pid(task_pid(current)); |
320dd101 SW |
657 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
658 | } | |
b3b94faa DT |
659 | spin_unlock(&gl->gl_spin); |
660 | ||
661 | return acquired; | |
662 | } | |
663 | ||
664 | /** | |
665 | * gfs2_glmutex_unlock - release a local lock on a glock | |
666 | * @gl: the glock | |
667 | * | |
668 | */ | |
669 | ||
feaa7bba | 670 | static void gfs2_glmutex_unlock(struct gfs2_glock *gl) |
b3b94faa | 671 | { |
eccba068 PE |
672 | struct pid *pid; |
673 | ||
b3b94faa DT |
674 | spin_lock(&gl->gl_spin); |
675 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
eccba068 PE |
676 | pid = gl->gl_owner_pid; |
677 | gl->gl_owner_pid = NULL; | |
320dd101 | 678 | gl->gl_ip = 0; |
b3b94faa DT |
679 | run_queue(gl); |
680 | spin_unlock(&gl->gl_spin); | |
eccba068 PE |
681 | |
682 | put_pid(pid); | |
b3b94faa DT |
683 | } |
684 | ||
685 | /** | |
3b8249f6 | 686 | * handle_callback - process a demote request |
b3b94faa DT |
687 | * @gl: the glock |
688 | * @state: the state the caller wants us to change to | |
689 | * | |
3b8249f6 SW |
690 | * There are only two requests that we are going to see in actual |
691 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
692 | */ |
693 | ||
c4f68a13 BM |
694 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
695 | int remote, unsigned long delay) | |
b3b94faa | 696 | { |
c4f68a13 BM |
697 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
698 | ||
b3b94faa | 699 | spin_lock(&gl->gl_spin); |
c4f68a13 BM |
700 | set_bit(bit, &gl->gl_flags); |
701 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
3b8249f6 SW |
702 | gl->gl_demote_state = state; |
703 | gl->gl_demote_time = jiffies; | |
d93cfa98 AD |
704 | if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN && |
705 | gl->gl_object) { | |
49e61f2e | 706 | gfs2_glock_schedule_for_reclaim(gl); |
d93cfa98 | 707 | spin_unlock(&gl->gl_spin); |
d93cfa98 AD |
708 | return; |
709 | } | |
26caee5b JW |
710 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
711 | gl->gl_demote_state != state) { | |
cc7e79b1 WC |
712 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) |
713 | gl->gl_waiters2 = 1; | |
714 | else | |
715 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 716 | } |
b3b94faa | 717 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
718 | } |
719 | ||
720 | /** | |
721 | * state_change - record that the glock is now in a different state | |
722 | * @gl: the glock | |
723 | * @new_state the new state | |
724 | * | |
725 | */ | |
726 | ||
727 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
728 | { | |
b3b94faa DT |
729 | int held1, held2; |
730 | ||
731 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
732 | held2 = (new_state != LM_ST_UNLOCKED); | |
733 | ||
734 | if (held1 != held2) { | |
6a6b3d01 | 735 | if (held2) |
b3b94faa | 736 | gfs2_glock_hold(gl); |
6a6b3d01 | 737 | else |
b3b94faa | 738 | gfs2_glock_put(gl); |
b3b94faa DT |
739 | } |
740 | ||
741 | gl->gl_state = new_state; | |
c4f68a13 | 742 | gl->gl_tchange = jiffies; |
b3b94faa DT |
743 | } |
744 | ||
745 | /** | |
746 | * xmote_bh - Called after the lock module is done acquiring a lock | |
747 | * @gl: The glock in question | |
748 | * @ret: the int returned from the lock module | |
749 | * | |
750 | */ | |
751 | ||
752 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
753 | { | |
754 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 755 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
756 | struct gfs2_holder *gh = gl->gl_req_gh; |
757 | int prev_state = gl->gl_state; | |
758 | int op_done = 1; | |
759 | ||
760 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
12132933 | 761 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
762 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); |
763 | ||
764 | state_change(gl, ret & LM_OUT_ST_MASK); | |
765 | ||
766 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
767 | if (glops->go_inval) | |
1a14d3a6 | 768 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
769 | } else if (gl->gl_state == LM_ST_DEFERRED) { |
770 | /* We might not want to do this here. | |
771 | Look at moving to the inode glops. */ | |
772 | if (glops->go_inval) | |
1a14d3a6 | 773 | glops->go_inval(gl, 0); |
b3b94faa DT |
774 | } |
775 | ||
776 | /* Deal with each possible exit condition */ | |
777 | ||
3b8249f6 | 778 | if (!gh) { |
b3b94faa | 779 | gl->gl_stamp = jiffies; |
87124e58 | 780 | if (ret & LM_OUT_CANCELED) { |
3b8249f6 | 781 | op_done = 0; |
87124e58 SW |
782 | } else { |
783 | spin_lock(&gl->gl_spin); | |
784 | if (gl->gl_state != gl->gl_demote_state) { | |
785 | gl->gl_req_bh = NULL; | |
786 | spin_unlock(&gl->gl_spin); | |
787 | gfs2_glock_drop_th(gl); | |
788 | gfs2_glock_put(gl); | |
789 | return; | |
790 | } | |
d93cfa98 | 791 | gfs2_demote_wake(gl); |
87124e58 SW |
792 | spin_unlock(&gl->gl_spin); |
793 | } | |
3b8249f6 | 794 | } else { |
b3b94faa DT |
795 | spin_lock(&gl->gl_spin); |
796 | list_del_init(&gh->gh_list); | |
797 | gh->gh_error = -EIO; | |
3b8249f6 SW |
798 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
799 | goto out; | |
800 | gh->gh_error = GLR_CANCELED; | |
801 | if (ret & LM_OUT_CANCELED) | |
802 | goto out; | |
803 | if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
804 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
b3b94faa | 805 | gh->gh_error = 0; |
3b8249f6 SW |
806 | set_bit(HIF_HOLDER, &gh->gh_iflags); |
807 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
808 | op_done = 0; | |
809 | goto out; | |
b3b94faa | 810 | } |
b3b94faa | 811 | gh->gh_error = GLR_TRYFAILED; |
3b8249f6 SW |
812 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
813 | goto out; | |
814 | gh->gh_error = -EINVAL; | |
b3b94faa DT |
815 | if (gfs2_assert_withdraw(sdp, 0) == -1) |
816 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
3b8249f6 SW |
817 | out: |
818 | spin_unlock(&gl->gl_spin); | |
b3b94faa DT |
819 | } |
820 | ||
821 | if (glops->go_xmote_bh) | |
822 | glops->go_xmote_bh(gl); | |
823 | ||
824 | if (op_done) { | |
825 | spin_lock(&gl->gl_spin); | |
826 | gl->gl_req_gh = NULL; | |
827 | gl->gl_req_bh = NULL; | |
828 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
829 | spin_unlock(&gl->gl_spin); |
830 | } | |
831 | ||
832 | gfs2_glock_put(gl); | |
833 | ||
fee852e3 | 834 | if (gh) |
3b8249f6 | 835 | gfs2_holder_wake(gh); |
b3b94faa DT |
836 | } |
837 | ||
838 | /** | |
839 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
840 | * @gl: The glock in question | |
841 | * @state: the requested state | |
842 | * @flags: modifier flags to the lock call | |
843 | * | |
844 | */ | |
845 | ||
87124e58 | 846 | static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh) |
b3b94faa DT |
847 | { |
848 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
3b8249f6 SW |
849 | int flags = gh ? gh->gh_flags : 0; |
850 | unsigned state = gh ? gh->gh_state : gl->gl_demote_state; | |
8fb4b536 | 851 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
852 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | |
853 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
854 | LM_FLAG_PRIORITY); | |
855 | unsigned int lck_ret; | |
856 | ||
b5d32bea SW |
857 | if (glops->go_xmote_th) |
858 | glops->go_xmote_th(gl); | |
859 | ||
b3b94faa | 860 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 861 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
862 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); |
863 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
864 | ||
b3b94faa DT |
865 | gfs2_glock_hold(gl); |
866 | gl->gl_req_bh = xmote_bh; | |
867 | ||
ec45d9f5 | 868 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); |
b3b94faa DT |
869 | |
870 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
871 | return; | |
872 | ||
873 | if (lck_ret & LM_OUT_ASYNC) | |
874 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
875 | else | |
876 | xmote_bh(gl, lck_ret); | |
877 | } | |
878 | ||
879 | /** | |
880 | * drop_bh - Called after a lock module unlock completes | |
881 | * @gl: the glock | |
882 | * @ret: the return status | |
883 | * | |
884 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
885 | * Doesn't drop the reference on the glock the top half took out | |
886 | * | |
887 | */ | |
888 | ||
889 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
890 | { | |
891 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 892 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
893 | struct gfs2_holder *gh = gl->gl_req_gh; |
894 | ||
b3b94faa | 895 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 896 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
897 | gfs2_assert_warn(sdp, !ret); |
898 | ||
899 | state_change(gl, LM_ST_UNLOCKED); | |
900 | ||
901 | if (glops->go_inval) | |
1a14d3a6 | 902 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
903 | |
904 | if (gh) { | |
905 | spin_lock(&gl->gl_spin); | |
906 | list_del_init(&gh->gh_list); | |
907 | gh->gh_error = 0; | |
908 | spin_unlock(&gl->gl_spin); | |
909 | } | |
910 | ||
b3b94faa | 911 | spin_lock(&gl->gl_spin); |
c4f68a13 | 912 | gfs2_demote_wake(gl); |
b3b94faa DT |
913 | gl->gl_req_gh = NULL; |
914 | gl->gl_req_bh = NULL; | |
915 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
916 | spin_unlock(&gl->gl_spin); |
917 | ||
918 | gfs2_glock_put(gl); | |
919 | ||
fee852e3 | 920 | if (gh) |
3b8249f6 | 921 | gfs2_holder_wake(gh); |
b3b94faa DT |
922 | } |
923 | ||
924 | /** | |
925 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
926 | * @gl: the glock | |
927 | * | |
928 | */ | |
929 | ||
b5d32bea | 930 | static void gfs2_glock_drop_th(struct gfs2_glock *gl) |
b3b94faa DT |
931 | { |
932 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 933 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
934 | unsigned int ret; |
935 | ||
3042a2cc SW |
936 | if (glops->go_xmote_th) |
937 | glops->go_xmote_th(gl); | |
b5d32bea | 938 | |
b3b94faa | 939 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 940 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
941 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); |
942 | ||
b3b94faa DT |
943 | gfs2_glock_hold(gl); |
944 | gl->gl_req_bh = drop_bh; | |
945 | ||
b3b94faa DT |
946 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
947 | ||
948 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
949 | return; | |
950 | ||
951 | if (!ret) | |
952 | drop_bh(gl, ret); | |
953 | else | |
954 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
955 | } | |
956 | ||
957 | /** | |
958 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
959 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
960 | * | |
961 | * Don't cancel GL_NOCANCEL requests. | |
962 | */ | |
963 | ||
964 | static void do_cancels(struct gfs2_holder *gh) | |
965 | { | |
966 | struct gfs2_glock *gl = gh->gh_gl; | |
967 | ||
968 | spin_lock(&gl->gl_spin); | |
969 | ||
970 | while (gl->gl_req_gh != gh && | |
971 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
972 | !list_empty(&gh->gh_list)) { | |
50299965 SW |
973 | if (gl->gl_req_bh && !(gl->gl_req_gh && |
974 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
b3b94faa DT |
975 | spin_unlock(&gl->gl_spin); |
976 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
977 | msleep(100); | |
978 | spin_lock(&gl->gl_spin); | |
979 | } else { | |
980 | spin_unlock(&gl->gl_spin); | |
981 | msleep(100); | |
982 | spin_lock(&gl->gl_spin); | |
983 | } | |
984 | } | |
985 | ||
986 | spin_unlock(&gl->gl_spin); | |
987 | } | |
988 | ||
989 | /** | |
990 | * glock_wait_internal - wait on a glock acquisition | |
991 | * @gh: the glock holder | |
992 | * | |
993 | * Returns: 0 on success | |
994 | */ | |
995 | ||
996 | static int glock_wait_internal(struct gfs2_holder *gh) | |
997 | { | |
998 | struct gfs2_glock *gl = gh->gh_gl; | |
999 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 1000 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1001 | |
1002 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
1003 | return -EIO; | |
1004 | ||
1005 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
1006 | spin_lock(&gl->gl_spin); | |
1007 | if (gl->gl_req_gh != gh && | |
1008 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1009 | !list_empty(&gh->gh_list)) { | |
1010 | list_del_init(&gh->gh_list); | |
1011 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
1012 | run_queue(gl); |
1013 | spin_unlock(&gl->gl_spin); | |
1014 | return gh->gh_error; | |
1015 | } | |
1016 | spin_unlock(&gl->gl_spin); | |
1017 | } | |
1018 | ||
1019 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1020 | do_cancels(gh); | |
1021 | ||
fee852e3 | 1022 | wait_on_holder(gh); |
b3b94faa DT |
1023 | if (gh->gh_error) |
1024 | return gh->gh_error; | |
1025 | ||
1026 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
85d1da67 | 1027 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, |
b3b94faa DT |
1028 | gh->gh_flags)); |
1029 | ||
1030 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
1031 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1032 | ||
1033 | if (glops->go_lock) { | |
1034 | gh->gh_error = glops->go_lock(gh); | |
1035 | if (gh->gh_error) { | |
1036 | spin_lock(&gl->gl_spin); | |
1037 | list_del_init(&gh->gh_list); | |
b3b94faa DT |
1038 | spin_unlock(&gl->gl_spin); |
1039 | } | |
1040 | } | |
1041 | ||
1042 | spin_lock(&gl->gl_spin); | |
1043 | gl->gl_req_gh = NULL; | |
1044 | gl->gl_req_bh = NULL; | |
1045 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
1046 | run_queue(gl); |
1047 | spin_unlock(&gl->gl_spin); | |
1048 | } | |
1049 | ||
1050 | return gh->gh_error; | |
1051 | } | |
1052 | ||
1053 | static inline struct gfs2_holder * | |
b1e058da | 1054 | find_holder_by_owner(struct list_head *head, struct pid *pid) |
b3b94faa DT |
1055 | { |
1056 | struct gfs2_holder *gh; | |
1057 | ||
1058 | list_for_each_entry(gh, head, gh_list) { | |
04b933f2 | 1059 | if (gh->gh_owner_pid == pid) |
b3b94faa DT |
1060 | return gh; |
1061 | } | |
1062 | ||
1063 | return NULL; | |
1064 | } | |
1065 | ||
7c52b166 RP |
1066 | static void print_dbg(struct glock_iter *gi, const char *fmt, ...) |
1067 | { | |
1068 | va_list args; | |
1069 | ||
1070 | va_start(args, fmt); | |
1071 | if (gi) { | |
1072 | vsprintf(gi->string, fmt, args); | |
1073 | seq_printf(gi->seq, gi->string); | |
1074 | } | |
1075 | else | |
1076 | vprintk(fmt, args); | |
1077 | va_end(args); | |
1078 | } | |
1079 | ||
b3b94faa DT |
1080 | /** |
1081 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1082 | * @gh: the holder structure to add | |
1083 | * | |
1084 | */ | |
1085 | ||
1086 | static void add_to_queue(struct gfs2_holder *gh) | |
1087 | { | |
1088 | struct gfs2_glock *gl = gh->gh_gl; | |
1089 | struct gfs2_holder *existing; | |
1090 | ||
b1e058da | 1091 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
1092 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
1093 | BUG(); | |
190562bd | 1094 | |
b4c20166 AD |
1095 | if (!(gh->gh_flags & GL_FLOCK)) { |
1096 | existing = find_holder_by_owner(&gl->gl_holders, | |
1097 | gh->gh_owner_pid); | |
1098 | if (existing) { | |
1099 | print_symbol(KERN_WARNING "original: %s\n", | |
1100 | existing->gh_ip); | |
b1e058da PE |
1101 | printk(KERN_INFO "pid : %d\n", |
1102 | pid_nr(existing->gh_owner_pid)); | |
b4c20166 AD |
1103 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
1104 | existing->gh_gl->gl_name.ln_type, | |
1105 | existing->gh_gl->gl_state); | |
1106 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
b1e058da PE |
1107 | printk(KERN_INFO "pid : %d\n", |
1108 | pid_nr(gh->gh_owner_pid)); | |
b4c20166 AD |
1109 | printk(KERN_INFO "lock type : %d lock state : %d\n", |
1110 | gl->gl_name.ln_type, gl->gl_state); | |
1111 | BUG(); | |
1112 | } | |
1113 | ||
1114 | existing = find_holder_by_owner(&gl->gl_waiters3, | |
1115 | gh->gh_owner_pid); | |
1116 | if (existing) { | |
1117 | print_symbol(KERN_WARNING "original: %s\n", | |
1118 | existing->gh_ip); | |
1119 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1120 | BUG(); | |
1121 | } | |
b3b94faa DT |
1122 | } |
1123 | ||
b3b94faa DT |
1124 | if (gh->gh_flags & LM_FLAG_PRIORITY) |
1125 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1126 | else | |
907b9bce | 1127 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); |
b3b94faa DT |
1128 | } |
1129 | ||
1130 | /** | |
1131 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1132 | * @gh: the holder structure | |
1133 | * | |
1134 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1135 | * | |
1136 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1137 | */ | |
1138 | ||
1139 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1140 | { | |
1141 | struct gfs2_glock *gl = gh->gh_gl; | |
1142 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1143 | int error = 0; | |
1144 | ||
320dd101 | 1145 | restart: |
b3b94faa DT |
1146 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
1147 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1148 | return -EIO; | |
1149 | } | |
1150 | ||
b3b94faa DT |
1151 | spin_lock(&gl->gl_spin); |
1152 | add_to_queue(gh); | |
1153 | run_queue(gl); | |
1154 | spin_unlock(&gl->gl_spin); | |
1155 | ||
1156 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1157 | error = glock_wait_internal(gh); | |
1158 | if (error == GLR_CANCELED) { | |
190562bd | 1159 | msleep(100); |
b3b94faa DT |
1160 | goto restart; |
1161 | } | |
1162 | } | |
1163 | ||
b3b94faa DT |
1164 | return error; |
1165 | } | |
1166 | ||
1167 | /** | |
1168 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1169 | * @gh: the holder | |
1170 | * | |
1171 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1172 | */ | |
1173 | ||
1174 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1175 | { | |
1176 | struct gfs2_glock *gl = gh->gh_gl; | |
1177 | int ready = 0; | |
1178 | ||
1179 | spin_lock(&gl->gl_spin); | |
1180 | ||
1181 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1182 | ready = 1; | |
1183 | else if (list_empty(&gh->gh_list)) { | |
1184 | if (gh->gh_error == GLR_CANCELED) { | |
1185 | spin_unlock(&gl->gl_spin); | |
190562bd | 1186 | msleep(100); |
b3b94faa DT |
1187 | if (gfs2_glock_nq(gh)) |
1188 | return 1; | |
1189 | return 0; | |
1190 | } else | |
1191 | ready = 1; | |
1192 | } | |
1193 | ||
1194 | spin_unlock(&gl->gl_spin); | |
1195 | ||
1196 | return ready; | |
1197 | } | |
1198 | ||
1199 | /** | |
1200 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1201 | * @gh: the holder structure | |
1202 | * | |
1203 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1204 | */ | |
1205 | ||
1206 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1207 | { | |
1208 | int error; | |
1209 | ||
1210 | error = glock_wait_internal(gh); | |
1211 | if (error == GLR_CANCELED) { | |
190562bd | 1212 | msleep(100); |
b3b94faa DT |
1213 | gh->gh_flags &= ~GL_ASYNC; |
1214 | error = gfs2_glock_nq(gh); | |
1215 | } | |
1216 | ||
1217 | return error; | |
1218 | } | |
1219 | ||
1220 | /** | |
1221 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1222 | * @gh: the glock holder | |
1223 | * | |
1224 | */ | |
1225 | ||
1226 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1227 | { | |
1228 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1229 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1230 | unsigned delay = 0; |
b3b94faa | 1231 | |
b3b94faa | 1232 | if (gh->gh_flags & GL_NOCACHE) |
c4f68a13 | 1233 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa DT |
1234 | |
1235 | gfs2_glmutex_lock(gl); | |
1236 | ||
1237 | spin_lock(&gl->gl_spin); | |
1238 | list_del_init(&gh->gh_list); | |
1239 | ||
1240 | if (list_empty(&gl->gl_holders)) { | |
3042a2cc SW |
1241 | if (glops->go_unlock) { |
1242 | spin_unlock(&gl->gl_spin); | |
b3b94faa | 1243 | glops->go_unlock(gh); |
3042a2cc SW |
1244 | spin_lock(&gl->gl_spin); |
1245 | } | |
3b8249f6 | 1246 | gl->gl_stamp = jiffies; |
b3b94faa DT |
1247 | } |
1248 | ||
1249 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa | 1250 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1251 | |
1252 | gfs2_glock_hold(gl); | |
1253 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1254 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1255 | delay = gl->gl_ops->go_min_hold_time; | |
1256 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1257 | gfs2_glock_put(gl); | |
b3b94faa DT |
1258 | } |
1259 | ||
d93cfa98 AD |
1260 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1261 | { | |
1262 | struct gfs2_glock *gl = gh->gh_gl; | |
1263 | gfs2_glock_dq(gh); | |
1264 | wait_on_demote(gl); | |
1265 | } | |
1266 | ||
b3b94faa DT |
1267 | /** |
1268 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1269 | * @gh: the holder structure | |
1270 | * | |
1271 | */ | |
1272 | ||
1273 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1274 | { | |
1275 | gfs2_glock_dq(gh); | |
1276 | gfs2_holder_uninit(gh); | |
1277 | } | |
1278 | ||
1279 | /** | |
1280 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1281 | * @sdp: the filesystem | |
1282 | * @number: the lock number | |
1283 | * @glops: the glock operations for the type of glock | |
1284 | * @state: the state to acquire the glock in | |
1285 | * @flags: modifier flags for the aquisition | |
1286 | * @gh: the struct gfs2_holder | |
1287 | * | |
1288 | * Returns: errno | |
1289 | */ | |
1290 | ||
cd915493 | 1291 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1292 | const struct gfs2_glock_operations *glops, |
1293 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1294 | { |
1295 | struct gfs2_glock *gl; | |
1296 | int error; | |
1297 | ||
1298 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1299 | if (!error) { | |
1300 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1301 | gfs2_glock_put(gl); | |
1302 | } | |
1303 | ||
1304 | return error; | |
1305 | } | |
1306 | ||
1307 | /** | |
1308 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1309 | * @arg_a: the first structure | |
1310 | * @arg_b: the second structure | |
1311 | * | |
1312 | */ | |
1313 | ||
1314 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1315 | { | |
a5e08a9e SW |
1316 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1317 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1318 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1319 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1320 | |
1321 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1322 | return 1; |
1323 | if (a->ln_number < b->ln_number) | |
1324 | return -1; | |
1c0f4872 | 1325 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1326 | return 0; |
b3b94faa DT |
1327 | } |
1328 | ||
1329 | /** | |
1330 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1331 | * @num_gh: the number of structures | |
1332 | * @ghs: an array of struct gfs2_holder structures | |
1333 | * | |
1334 | * Returns: 0 on success (all glocks acquired), | |
1335 | * errno on failure (no glocks acquired) | |
1336 | */ | |
1337 | ||
1338 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1339 | struct gfs2_holder **p) | |
1340 | { | |
1341 | unsigned int x; | |
1342 | int error = 0; | |
1343 | ||
1344 | for (x = 0; x < num_gh; x++) | |
1345 | p[x] = &ghs[x]; | |
1346 | ||
1347 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1348 | ||
1349 | for (x = 0; x < num_gh; x++) { | |
1350 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1351 | ||
1352 | error = gfs2_glock_nq(p[x]); | |
1353 | if (error) { | |
1354 | while (x--) | |
1355 | gfs2_glock_dq(p[x]); | |
1356 | break; | |
1357 | } | |
1358 | } | |
1359 | ||
1360 | return error; | |
1361 | } | |
1362 | ||
1363 | /** | |
1364 | * gfs2_glock_nq_m - acquire multiple glocks | |
1365 | * @num_gh: the number of structures | |
1366 | * @ghs: an array of struct gfs2_holder structures | |
1367 | * | |
b3b94faa DT |
1368 | * |
1369 | * Returns: 0 on success (all glocks acquired), | |
1370 | * errno on failure (no glocks acquired) | |
1371 | */ | |
1372 | ||
1373 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1374 | { | |
eaf5bd3c SW |
1375 | struct gfs2_holder *tmp[4]; |
1376 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1377 | int error = 0; |
1378 | ||
eaf5bd3c SW |
1379 | switch(num_gh) { |
1380 | case 0: | |
b3b94faa | 1381 | return 0; |
eaf5bd3c | 1382 | case 1: |
b3b94faa DT |
1383 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1384 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1385 | default: |
1386 | if (num_gh <= 4) | |
b3b94faa | 1387 | break; |
eaf5bd3c SW |
1388 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1389 | if (!pph) | |
1390 | return -ENOMEM; | |
b3b94faa DT |
1391 | } |
1392 | ||
eaf5bd3c | 1393 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1394 | |
eaf5bd3c SW |
1395 | if (pph != tmp) |
1396 | kfree(pph); | |
b3b94faa DT |
1397 | |
1398 | return error; | |
1399 | } | |
1400 | ||
1401 | /** | |
1402 | * gfs2_glock_dq_m - release multiple glocks | |
1403 | * @num_gh: the number of structures | |
1404 | * @ghs: an array of struct gfs2_holder structures | |
1405 | * | |
1406 | */ | |
1407 | ||
1408 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1409 | { | |
1410 | unsigned int x; | |
1411 | ||
1412 | for (x = 0; x < num_gh; x++) | |
1413 | gfs2_glock_dq(&ghs[x]); | |
1414 | } | |
1415 | ||
1416 | /** | |
1417 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1418 | * @num_gh: the number of structures | |
1419 | * @ghs: an array of struct gfs2_holder structures | |
1420 | * | |
1421 | */ | |
1422 | ||
1423 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1424 | { | |
1425 | unsigned int x; | |
1426 | ||
1427 | for (x = 0; x < num_gh; x++) | |
1428 | gfs2_glock_dq_uninit(&ghs[x]); | |
1429 | } | |
1430 | ||
b3b94faa DT |
1431 | /** |
1432 | * gfs2_lvb_hold - attach a LVB from a glock | |
1433 | * @gl: The glock in question | |
1434 | * | |
1435 | */ | |
1436 | ||
1437 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1438 | { | |
1439 | int error; | |
1440 | ||
1441 | gfs2_glmutex_lock(gl); | |
1442 | ||
1443 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1444 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1445 | if (error) { | |
1446 | gfs2_glmutex_unlock(gl); | |
1447 | return error; | |
1448 | } | |
1449 | gfs2_glock_hold(gl); | |
1450 | } | |
1451 | atomic_inc(&gl->gl_lvb_count); | |
1452 | ||
1453 | gfs2_glmutex_unlock(gl); | |
1454 | ||
1455 | return 0; | |
1456 | } | |
1457 | ||
1458 | /** | |
1459 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1460 | * @gl: The glock in question | |
1461 | * | |
1462 | */ | |
1463 | ||
1464 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1465 | { | |
1466 | gfs2_glock_hold(gl); | |
1467 | gfs2_glmutex_lock(gl); | |
1468 | ||
1469 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1470 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1471 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1472 | gl->gl_lvb = NULL; | |
1473 | gfs2_glock_put(gl); | |
1474 | } | |
1475 | ||
1476 | gfs2_glmutex_unlock(gl); | |
1477 | gfs2_glock_put(gl); | |
1478 | } | |
1479 | ||
b3b94faa DT |
1480 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1481 | unsigned int state) | |
1482 | { | |
1483 | struct gfs2_glock *gl; | |
c4f68a13 BM |
1484 | unsigned long delay = 0; |
1485 | unsigned long holdtime; | |
1486 | unsigned long now = jiffies; | |
b3b94faa DT |
1487 | |
1488 | gl = gfs2_glock_find(sdp, name); | |
1489 | if (!gl) | |
1490 | return; | |
1491 | ||
c4f68a13 BM |
1492 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1493 | if (time_before(now, holdtime)) | |
1494 | delay = holdtime - now; | |
b3b94faa | 1495 | |
c4f68a13 BM |
1496 | handle_callback(gl, state, 1, delay); |
1497 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1498 | gfs2_glock_put(gl); | |
b3b94faa DT |
1499 | } |
1500 | ||
1501 | /** | |
1502 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1503 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1504 | * @type: Type of callback |
1505 | * @data: Type dependent data pointer | |
1506 | * | |
1507 | * Called by the locking module when it wants to tell us something. | |
1508 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1509 | * a journal from another client needs to be recovered. | |
1510 | */ | |
1511 | ||
9b47c11d | 1512 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1513 | { |
9b47c11d | 1514 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1515 | |
b3b94faa DT |
1516 | switch (type) { |
1517 | case LM_CB_NEED_E: | |
e7f5c01c | 1518 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1519 | return; |
1520 | ||
1521 | case LM_CB_NEED_D: | |
e7f5c01c | 1522 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1523 | return; |
1524 | ||
1525 | case LM_CB_NEED_S: | |
e7f5c01c | 1526 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1527 | return; |
1528 | ||
1529 | case LM_CB_ASYNC: { | |
e7f5c01c | 1530 | struct lm_async_cb *async = data; |
b3b94faa DT |
1531 | struct gfs2_glock *gl; |
1532 | ||
61be084e | 1533 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1534 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1535 | if (gfs2_assert_warn(sdp, gl)) | |
1536 | return; | |
1537 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1538 | gl->gl_req_bh(gl, async->lc_ret); | |
c4f68a13 BM |
1539 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
1540 | gfs2_glock_put(gl); | |
61be084e | 1541 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1542 | return; |
1543 | } | |
1544 | ||
1545 | case LM_CB_NEED_RECOVERY: | |
1546 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1547 | if (sdp->sd_recoverd_process) | |
1548 | wake_up_process(sdp->sd_recoverd_process); | |
1549 | return; | |
1550 | ||
1551 | case LM_CB_DROPLOCKS: | |
1552 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1553 | gfs2_quota_scan(sdp); | |
1554 | return; | |
1555 | ||
1556 | default: | |
1557 | gfs2_assert_warn(sdp, 0); | |
1558 | return; | |
1559 | } | |
1560 | } | |
1561 | ||
b3b94faa DT |
1562 | /** |
1563 | * demote_ok - Check to see if it's ok to unlock a glock | |
1564 | * @gl: the glock | |
1565 | * | |
1566 | * Returns: 1 if it's ok | |
1567 | */ | |
1568 | ||
1569 | static int demote_ok(struct gfs2_glock *gl) | |
1570 | { | |
8fb4b536 | 1571 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1572 | int demote = 1; |
1573 | ||
1574 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1575 | demote = 0; | |
b3b94faa DT |
1576 | else if (glops->go_demote_ok) |
1577 | demote = glops->go_demote_ok(gl); | |
1578 | ||
1579 | return demote; | |
1580 | } | |
1581 | ||
1582 | /** | |
1583 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1584 | * @gl: the glock | |
1585 | * | |
1586 | */ | |
1587 | ||
1588 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1589 | { | |
1590 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1591 | ||
1592 | spin_lock(&sdp->sd_reclaim_lock); | |
1593 | if (list_empty(&gl->gl_reclaim)) { | |
1594 | gfs2_glock_hold(gl); | |
1595 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1596 | atomic_inc(&sdp->sd_reclaim_count); | |
1597 | } | |
1598 | spin_unlock(&sdp->sd_reclaim_lock); | |
1599 | ||
1600 | wake_up(&sdp->sd_reclaim_wq); | |
1601 | } | |
1602 | ||
1603 | /** | |
1604 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1605 | * @sdp: the filesystem | |
1606 | * | |
1607 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1608 | * different glock and we notice that there are a lot of glocks in the | |
1609 | * reclaim list. | |
1610 | * | |
1611 | */ | |
1612 | ||
1613 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1614 | { | |
1615 | struct gfs2_glock *gl; | |
1616 | ||
1617 | spin_lock(&sdp->sd_reclaim_lock); | |
1618 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1619 | spin_unlock(&sdp->sd_reclaim_lock); | |
1620 | return; | |
1621 | } | |
1622 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1623 | struct gfs2_glock, gl_reclaim); | |
1624 | list_del_init(&gl->gl_reclaim); | |
1625 | spin_unlock(&sdp->sd_reclaim_lock); | |
1626 | ||
1627 | atomic_dec(&sdp->sd_reclaim_count); | |
1628 | atomic_inc(&sdp->sd_reclaimed); | |
1629 | ||
1630 | if (gfs2_glmutex_trylock(gl)) { | |
12132933 | 1631 | if (list_empty(&gl->gl_holders) && |
50299965 | 1632 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
c4f68a13 | 1633 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa DT |
1634 | gfs2_glmutex_unlock(gl); |
1635 | } | |
1636 | ||
1637 | gfs2_glock_put(gl); | |
1638 | } | |
1639 | ||
1640 | /** | |
1641 | * examine_bucket - Call a function for glock in a hash bucket | |
1642 | * @examiner: the function | |
1643 | * @sdp: the filesystem | |
1644 | * @bucket: the bucket | |
1645 | * | |
1646 | * Returns: 1 if the bucket has entries | |
1647 | */ | |
1648 | ||
1649 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1650 | unsigned int hash) |
b3b94faa | 1651 | { |
24264434 SW |
1652 | struct gfs2_glock *gl, *prev = NULL; |
1653 | int has_entries = 0; | |
b6397893 | 1654 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1655 | |
24264434 | 1656 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1657 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1658 | if (hlist_empty(head)) | |
24264434 | 1659 | goto out; |
b6397893 SW |
1660 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1661 | while(1) { | |
8fbbfd21 | 1662 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1663 | gfs2_glock_hold(gl); |
24264434 SW |
1664 | read_unlock(gl_lock_addr(hash)); |
1665 | if (prev) | |
1666 | gfs2_glock_put(prev); | |
1667 | prev = gl; | |
1668 | examiner(gl); | |
a8336344 | 1669 | has_entries = 1; |
24264434 | 1670 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1671 | } |
b6397893 SW |
1672 | if (gl->gl_list.next == NULL) |
1673 | break; | |
24264434 | 1674 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1675 | } |
24264434 SW |
1676 | out: |
1677 | read_unlock(gl_lock_addr(hash)); | |
1678 | if (prev) | |
1679 | gfs2_glock_put(prev); | |
8fbbfd21 | 1680 | cond_resched(); |
24264434 | 1681 | return has_entries; |
b3b94faa DT |
1682 | } |
1683 | ||
1684 | /** | |
1685 | * scan_glock - look at a glock and see if we can reclaim it | |
1686 | * @gl: the glock to look at | |
1687 | * | |
1688 | */ | |
1689 | ||
1690 | static void scan_glock(struct gfs2_glock *gl) | |
1691 | { | |
b004157a | 1692 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1693 | return; |
a2242db0 | 1694 | |
b3b94faa | 1695 | if (gfs2_glmutex_trylock(gl)) { |
12132933 | 1696 | if (list_empty(&gl->gl_holders) && |
24264434 | 1697 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa | 1698 | goto out_schedule; |
b3b94faa DT |
1699 | gfs2_glmutex_unlock(gl); |
1700 | } | |
b3b94faa DT |
1701 | return; |
1702 | ||
627add2d | 1703 | out_schedule: |
b3b94faa DT |
1704 | gfs2_glmutex_unlock(gl); |
1705 | gfs2_glock_schedule_for_reclaim(gl); | |
b3b94faa DT |
1706 | } |
1707 | ||
b3b94faa DT |
1708 | /** |
1709 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1710 | * @gl: the glock to look at | |
1711 | * | |
1712 | */ | |
1713 | ||
1714 | static void clear_glock(struct gfs2_glock *gl) | |
1715 | { | |
1716 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1717 | int released; | |
1718 | ||
1719 | spin_lock(&sdp->sd_reclaim_lock); | |
1720 | if (!list_empty(&gl->gl_reclaim)) { | |
1721 | list_del_init(&gl->gl_reclaim); | |
1722 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1723 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1724 | released = gfs2_glock_put(gl); |
1725 | gfs2_assert(sdp, !released); | |
190562bd SW |
1726 | } else { |
1727 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1728 | } |
b3b94faa DT |
1729 | |
1730 | if (gfs2_glmutex_trylock(gl)) { | |
90101c31 | 1731 | if (list_empty(&gl->gl_holders) && |
b3b94faa | 1732 | gl->gl_state != LM_ST_UNLOCKED) |
c4f68a13 | 1733 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa DT |
1734 | gfs2_glmutex_unlock(gl); |
1735 | } | |
b3b94faa DT |
1736 | } |
1737 | ||
1738 | /** | |
1739 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1740 | * @sdp: the filesystem | |
1741 | * @wait: wait until it's all gone | |
1742 | * | |
1743 | * Called when unmounting the filesystem, or when inter-node lock manager | |
1744 | * requests DROPLOCKS because it is running out of capacity. | |
1745 | */ | |
1746 | ||
1747 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
1748 | { | |
1749 | unsigned long t; | |
1750 | unsigned int x; | |
1751 | int cont; | |
1752 | ||
1753 | t = jiffies; | |
1754 | ||
1755 | for (;;) { | |
1756 | cont = 0; | |
24264434 | 1757 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1758 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1759 | cont = 1; |
24264434 | 1760 | } |
b3b94faa DT |
1761 | |
1762 | if (!wait || !cont) | |
1763 | break; | |
1764 | ||
1765 | if (time_after_eq(jiffies, | |
1766 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1767 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1768 | "Dumping lock state...\n"); | |
1769 | gfs2_dump_lockstate(sdp); | |
1770 | t = jiffies; | |
1771 | } | |
1772 | ||
61be084e | 1773 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1774 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1775 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1776 | msleep(10); |
b3b94faa DT |
1777 | } |
1778 | } | |
1779 | ||
1780 | /* | |
1781 | * Diagnostic routines to help debug distributed deadlock | |
1782 | */ | |
1783 | ||
04b933f2 RP |
1784 | static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt, |
1785 | unsigned long address) | |
1786 | { | |
7a0079d9 | 1787 | char buffer[KSYM_SYMBOL_LEN]; |
04b933f2 | 1788 | |
7a0079d9 RP |
1789 | sprint_symbol(buffer, address); |
1790 | print_dbg(gi, fmt, buffer); | |
04b933f2 RP |
1791 | } |
1792 | ||
b3b94faa DT |
1793 | /** |
1794 | * dump_holder - print information about a glock holder | |
1795 | * @str: a string naming the type of holder | |
1796 | * @gh: the glock holder | |
1797 | * | |
1798 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1799 | */ | |
1800 | ||
7c52b166 RP |
1801 | static int dump_holder(struct glock_iter *gi, char *str, |
1802 | struct gfs2_holder *gh) | |
b3b94faa DT |
1803 | { |
1804 | unsigned int x; | |
04b933f2 | 1805 | struct task_struct *gh_owner; |
b3b94faa | 1806 | |
7c52b166 | 1807 | print_dbg(gi, " %s\n", str); |
04b933f2 | 1808 | if (gh->gh_owner_pid) { |
b1e058da PE |
1809 | print_dbg(gi, " owner = %ld ", |
1810 | (long)pid_nr(gh->gh_owner_pid)); | |
1811 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); | |
04b933f2 RP |
1812 | if (gh_owner) |
1813 | print_dbg(gi, "(%s)\n", gh_owner->comm); | |
1814 | else | |
1815 | print_dbg(gi, "(ended)\n"); | |
1816 | } else | |
1817 | print_dbg(gi, " owner = -1\n"); | |
7c52b166 RP |
1818 | print_dbg(gi, " gh_state = %u\n", gh->gh_state); |
1819 | print_dbg(gi, " gh_flags ="); | |
b3b94faa DT |
1820 | for (x = 0; x < 32; x++) |
1821 | if (gh->gh_flags & (1 << x)) | |
7c52b166 RP |
1822 | print_dbg(gi, " %u", x); |
1823 | print_dbg(gi, " \n"); | |
1824 | print_dbg(gi, " error = %d\n", gh->gh_error); | |
1825 | print_dbg(gi, " gh_iflags ="); | |
b3b94faa DT |
1826 | for (x = 0; x < 32; x++) |
1827 | if (test_bit(x, &gh->gh_iflags)) | |
7c52b166 RP |
1828 | print_dbg(gi, " %u", x); |
1829 | print_dbg(gi, " \n"); | |
04b933f2 | 1830 | gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip); |
b3b94faa | 1831 | |
7c52b166 | 1832 | return 0; |
b3b94faa DT |
1833 | } |
1834 | ||
1835 | /** | |
1836 | * dump_inode - print information about an inode | |
1837 | * @ip: the inode | |
1838 | * | |
1839 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1840 | */ | |
1841 | ||
7c52b166 | 1842 | static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip) |
b3b94faa DT |
1843 | { |
1844 | unsigned int x; | |
b3b94faa | 1845 | |
7c52b166 RP |
1846 | print_dbg(gi, " Inode:\n"); |
1847 | print_dbg(gi, " num = %llu/%llu\n", | |
dbb7cae2 SW |
1848 | (unsigned long long)ip->i_no_formal_ino, |
1849 | (unsigned long long)ip->i_no_addr); | |
7c52b166 RP |
1850 | print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode)); |
1851 | print_dbg(gi, " i_flags ="); | |
b3b94faa DT |
1852 | for (x = 0; x < 32; x++) |
1853 | if (test_bit(x, &ip->i_flags)) | |
7c52b166 RP |
1854 | print_dbg(gi, " %u", x); |
1855 | print_dbg(gi, " \n"); | |
1856 | return 0; | |
b3b94faa DT |
1857 | } |
1858 | ||
1859 | /** | |
1860 | * dump_glock - print information about a glock | |
1861 | * @gl: the glock | |
1862 | * @count: where we are in the buffer | |
1863 | * | |
1864 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1865 | */ | |
1866 | ||
7c52b166 | 1867 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl) |
b3b94faa DT |
1868 | { |
1869 | struct gfs2_holder *gh; | |
1870 | unsigned int x; | |
1871 | int error = -ENOBUFS; | |
04b933f2 | 1872 | struct task_struct *gl_owner; |
b3b94faa DT |
1873 | |
1874 | spin_lock(&gl->gl_spin); | |
1875 | ||
a947e033 | 1876 | print_dbg(gi, "Glock 0x%p (%u, 0x%llx)\n", gl, gl->gl_name.ln_type, |
7c52b166 RP |
1877 | (unsigned long long)gl->gl_name.ln_number); |
1878 | print_dbg(gi, " gl_flags ="); | |
85d1da67 | 1879 | for (x = 0; x < 32; x++) { |
b3b94faa | 1880 | if (test_bit(x, &gl->gl_flags)) |
7c52b166 RP |
1881 | print_dbg(gi, " %u", x); |
1882 | } | |
04b933f2 RP |
1883 | if (!test_bit(GLF_LOCK, &gl->gl_flags)) |
1884 | print_dbg(gi, " (unlocked)"); | |
7c52b166 RP |
1885 | print_dbg(gi, " \n"); |
1886 | print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref)); | |
1887 | print_dbg(gi, " gl_state = %u\n", gl->gl_state); | |
04b933f2 | 1888 | if (gl->gl_owner_pid) { |
eccba068 | 1889 | gl_owner = pid_task(gl->gl_owner_pid, PIDTYPE_PID); |
04b933f2 RP |
1890 | if (gl_owner) |
1891 | print_dbg(gi, " gl_owner = pid %d (%s)\n", | |
eccba068 | 1892 | pid_nr(gl->gl_owner_pid), gl_owner->comm); |
04b933f2 RP |
1893 | else |
1894 | print_dbg(gi, " gl_owner = %d (ended)\n", | |
eccba068 | 1895 | pid_nr(gl->gl_owner_pid)); |
04b933f2 RP |
1896 | } else |
1897 | print_dbg(gi, " gl_owner = -1\n"); | |
7c52b166 RP |
1898 | print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip); |
1899 | print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); | |
1900 | print_dbg(gi, " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
1901 | print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
1902 | print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
7c52b166 RP |
1903 | print_dbg(gi, " reclaim = %s\n", |
1904 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); | |
b3b94faa | 1905 | if (gl->gl_aspace) |
7c52b166 RP |
1906 | print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, |
1907 | gl->gl_aspace->i_mapping->nrpages); | |
b3b94faa | 1908 | else |
7c52b166 RP |
1909 | print_dbg(gi, " aspace = no\n"); |
1910 | print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa | 1911 | if (gl->gl_req_gh) { |
7c52b166 | 1912 | error = dump_holder(gi, "Request", gl->gl_req_gh); |
b3b94faa DT |
1913 | if (error) |
1914 | goto out; | |
1915 | } | |
1916 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
7c52b166 | 1917 | error = dump_holder(gi, "Holder", gh); |
b3b94faa DT |
1918 | if (error) |
1919 | goto out; | |
1920 | } | |
1921 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
7c52b166 | 1922 | error = dump_holder(gi, "Waiter1", gh); |
b3b94faa DT |
1923 | if (error) |
1924 | goto out; | |
1925 | } | |
b3b94faa | 1926 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { |
7c52b166 | 1927 | error = dump_holder(gi, "Waiter3", gh); |
b3b94faa DT |
1928 | if (error) |
1929 | goto out; | |
1930 | } | |
3b8249f6 SW |
1931 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
1932 | print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n", | |
cd81a4ba RP |
1933 | gl->gl_demote_state, (unsigned long long) |
1934 | (jiffies - gl->gl_demote_time)*(1000000/HZ)); | |
3b8249f6 | 1935 | } |
5c676f6d | 1936 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa | 1937 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
7c52b166 RP |
1938 | list_empty(&gl->gl_holders)) { |
1939 | error = dump_inode(gi, gl->gl_object); | |
b3b94faa DT |
1940 | if (error) |
1941 | goto out; | |
1942 | } else { | |
1943 | error = -ENOBUFS; | |
7c52b166 | 1944 | print_dbg(gi, " Inode: busy\n"); |
b3b94faa DT |
1945 | } |
1946 | } | |
1947 | ||
1948 | error = 0; | |
1949 | ||
a91ea69f | 1950 | out: |
b3b94faa | 1951 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
1952 | return error; |
1953 | } | |
1954 | ||
1955 | /** | |
1956 | * gfs2_dump_lockstate - print out the current lockstate | |
1957 | * @sdp: the filesystem | |
1958 | * @ub: the buffer to copy the information into | |
1959 | * | |
1960 | * If @ub is NULL, dump the lockstate to the console. | |
1961 | * | |
1962 | */ | |
1963 | ||
08bc2dbc | 1964 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1965 | { |
b3b94faa | 1966 | struct gfs2_glock *gl; |
b6397893 | 1967 | struct hlist_node *h; |
b3b94faa DT |
1968 | unsigned int x; |
1969 | int error = 0; | |
1970 | ||
1971 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1972 | |
087efdd3 | 1973 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1974 | |
b6397893 | 1975 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1976 | if (gl->gl_sbd != sdp) |
1977 | continue; | |
b3b94faa | 1978 | |
7c52b166 | 1979 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1980 | if (error) |
1981 | break; | |
1982 | } | |
1983 | ||
087efdd3 | 1984 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1985 | |
1986 | if (error) | |
1987 | break; | |
1988 | } | |
1989 | ||
1990 | ||
1991 | return error; | |
1992 | } | |
1993 | ||
8fbbfd21 SW |
1994 | /** |
1995 | * gfs2_scand - Look for cached glocks and inodes to toss from memory | |
1996 | * @sdp: Pointer to GFS2 superblock | |
1997 | * | |
1998 | * One of these daemons runs, finding candidates to add to sd_reclaim_list. | |
1999 | * See gfs2_glockd() | |
2000 | */ | |
2001 | ||
2002 | static int gfs2_scand(void *data) | |
2003 | { | |
2004 | unsigned x; | |
2005 | unsigned delay; | |
2006 | ||
2007 | while (!kthread_should_stop()) { | |
2008 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
2009 | examine_bucket(scan_glock, NULL, x); | |
2010 | if (freezing(current)) | |
2011 | refrigerator(); | |
2012 | delay = scand_secs; | |
2013 | if (delay < 1) | |
2014 | delay = 1; | |
2015 | schedule_timeout_interruptible(delay * HZ); | |
2016 | } | |
2017 | ||
2018 | return 0; | |
2019 | } | |
2020 | ||
2021 | ||
2022 | ||
85d1da67 SW |
2023 | int __init gfs2_glock_init(void) |
2024 | { | |
2025 | unsigned i; | |
2026 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 2027 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 2028 | } |
087efdd3 SW |
2029 | #ifdef GL_HASH_LOCK_SZ |
2030 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
2031 | rwlock_init(&gl_hash_locks[i]); | |
2032 | } | |
2033 | #endif | |
8fbbfd21 SW |
2034 | |
2035 | scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand"); | |
2036 | if (IS_ERR(scand_process)) | |
2037 | return PTR_ERR(scand_process); | |
2038 | ||
c4f68a13 BM |
2039 | glock_workqueue = create_workqueue("glock_workqueue"); |
2040 | if (IS_ERR(glock_workqueue)) { | |
2041 | kthread_stop(scand_process); | |
2042 | return PTR_ERR(glock_workqueue); | |
2043 | } | |
2044 | ||
85d1da67 SW |
2045 | return 0; |
2046 | } | |
2047 | ||
8fbbfd21 SW |
2048 | void gfs2_glock_exit(void) |
2049 | { | |
c4f68a13 | 2050 | destroy_workqueue(glock_workqueue); |
8fbbfd21 SW |
2051 | kthread_stop(scand_process); |
2052 | } | |
2053 | ||
2054 | module_param(scand_secs, uint, S_IRUGO|S_IWUSR); | |
2055 | MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs"); | |
2056 | ||
7c52b166 RP |
2057 | static int gfs2_glock_iter_next(struct glock_iter *gi) |
2058 | { | |
7b08fc62 SW |
2059 | struct gfs2_glock *gl; |
2060 | ||
a947e033 | 2061 | restart: |
7a0079d9 | 2062 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
2063 | gl = gi->gl; |
2064 | if (gl) { | |
a947e033 AD |
2065 | gi->gl = hlist_entry(gl->gl_list.next, |
2066 | struct gfs2_glock, gl_list); | |
7c52b166 | 2067 | if (gi->gl) |
7b08fc62 | 2068 | gfs2_glock_hold(gi->gl); |
7c52b166 | 2069 | } |
7a0079d9 | 2070 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
2071 | if (gl) |
2072 | gfs2_glock_put(gl); | |
a947e033 | 2073 | if (gl && gi->gl == NULL) |
7b08fc62 | 2074 | gi->hash++; |
a947e033 | 2075 | while(gi->gl == NULL) { |
7b08fc62 SW |
2076 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
2077 | return 1; | |
2078 | read_lock(gl_lock_addr(gi->hash)); | |
2079 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
2080 | struct gfs2_glock, gl_list); | |
2081 | if (gi->gl) | |
2082 | gfs2_glock_hold(gi->gl); | |
2083 | read_unlock(gl_lock_addr(gi->hash)); | |
a947e033 | 2084 | gi->hash++; |
7b08fc62 | 2085 | } |
a947e033 AD |
2086 | |
2087 | if (gi->sdp != gi->gl->gl_sbd) | |
2088 | goto restart; | |
2089 | ||
7c52b166 RP |
2090 | return 0; |
2091 | } | |
2092 | ||
2093 | static void gfs2_glock_iter_free(struct glock_iter *gi) | |
2094 | { | |
7b08fc62 SW |
2095 | if (gi->gl) |
2096 | gfs2_glock_put(gi->gl); | |
7c52b166 RP |
2097 | kfree(gi); |
2098 | } | |
2099 | ||
2100 | static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp) | |
2101 | { | |
2102 | struct glock_iter *gi; | |
2103 | ||
2104 | gi = kmalloc(sizeof (*gi), GFP_KERNEL); | |
2105 | if (!gi) | |
2106 | return NULL; | |
2107 | ||
2108 | gi->sdp = sdp; | |
2109 | gi->hash = 0; | |
7c52b166 | 2110 | gi->seq = NULL; |
a947e033 | 2111 | gi->gl = NULL; |
7c52b166 RP |
2112 | memset(gi->string, 0, sizeof(gi->string)); |
2113 | ||
a947e033 | 2114 | if (gfs2_glock_iter_next(gi)) { |
7c52b166 RP |
2115 | gfs2_glock_iter_free(gi); |
2116 | return NULL; | |
2117 | } | |
2118 | ||
2119 | return gi; | |
2120 | } | |
2121 | ||
2122 | static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos) | |
2123 | { | |
2124 | struct glock_iter *gi; | |
2125 | loff_t n = *pos; | |
2126 | ||
2127 | gi = gfs2_glock_iter_init(file->private); | |
2128 | if (!gi) | |
2129 | return NULL; | |
2130 | ||
7b08fc62 | 2131 | while(n--) { |
7c52b166 RP |
2132 | if (gfs2_glock_iter_next(gi)) { |
2133 | gfs2_glock_iter_free(gi); | |
2134 | return NULL; | |
2135 | } | |
2136 | } | |
2137 | ||
2138 | return gi; | |
2139 | } | |
2140 | ||
2141 | static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr, | |
2142 | loff_t *pos) | |
2143 | { | |
2144 | struct glock_iter *gi = iter_ptr; | |
2145 | ||
2146 | (*pos)++; | |
2147 | ||
2148 | if (gfs2_glock_iter_next(gi)) { | |
2149 | gfs2_glock_iter_free(gi); | |
2150 | return NULL; | |
2151 | } | |
2152 | ||
2153 | return gi; | |
2154 | } | |
2155 | ||
2156 | static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr) | |
2157 | { | |
7b08fc62 SW |
2158 | struct glock_iter *gi = iter_ptr; |
2159 | if (gi) | |
2160 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
2161 | } |
2162 | ||
2163 | static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr) | |
2164 | { | |
2165 | struct glock_iter *gi = iter_ptr; | |
2166 | ||
2167 | gi->seq = file; | |
2168 | dump_glock(gi, gi->gl); | |
2169 | ||
2170 | return 0; | |
2171 | } | |
2172 | ||
4ef29002 | 2173 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
2174 | .start = gfs2_glock_seq_start, |
2175 | .next = gfs2_glock_seq_next, | |
2176 | .stop = gfs2_glock_seq_stop, | |
2177 | .show = gfs2_glock_seq_show, | |
2178 | }; | |
2179 | ||
2180 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
2181 | { | |
2182 | struct seq_file *seq; | |
2183 | int ret; | |
2184 | ||
2185 | ret = seq_open(file, &gfs2_glock_seq_ops); | |
2186 | if (ret) | |
2187 | return ret; | |
2188 | ||
2189 | seq = file->private_data; | |
2190 | seq->private = inode->i_private; | |
2191 | ||
2192 | return 0; | |
2193 | } | |
2194 | ||
2195 | static const struct file_operations gfs2_debug_fops = { | |
2196 | .owner = THIS_MODULE, | |
2197 | .open = gfs2_debugfs_open, | |
2198 | .read = seq_read, | |
2199 | .llseek = seq_lseek, | |
2200 | .release = seq_release | |
2201 | }; | |
2202 | ||
2203 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
2204 | { | |
5f882096 RP |
2205 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
2206 | if (!sdp->debugfs_dir) | |
2207 | return -ENOMEM; | |
2208 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
2209 | S_IFREG | S_IRUGO, | |
2210 | sdp->debugfs_dir, sdp, | |
2211 | &gfs2_debug_fops); | |
2212 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
2213 | return -ENOMEM; |
2214 | ||
2215 | return 0; | |
2216 | } | |
2217 | ||
2218 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
2219 | { | |
5f882096 RP |
2220 | if (sdp && sdp->debugfs_dir) { |
2221 | if (sdp->debugfs_dentry_glocks) { | |
2222 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
2223 | sdp->debugfs_dentry_glocks = NULL; | |
2224 | } | |
2225 | debugfs_remove(sdp->debugfs_dir); | |
2226 | sdp->debugfs_dir = NULL; | |
2227 | } | |
7c52b166 RP |
2228 | } |
2229 | ||
2230 | int gfs2_register_debugfs(void) | |
2231 | { | |
2232 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
2233 | return gfs2_root ? 0 : -ENOMEM; | |
2234 | } | |
2235 | ||
2236 | void gfs2_unregister_debugfs(void) | |
2237 | { | |
2238 | debugfs_remove(gfs2_root); | |
5f882096 | 2239 | gfs2_root = NULL; |
7c52b166 | 2240 | } |