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Commit | Line | Data |
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b3b94faa DT |
1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
3a8a9a10 | 3 | * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. |
b3b94faa DT |
4 | * |
5 | * This copyrighted material is made available to anyone wishing to use, | |
6 | * modify, copy, or redistribute it subject to the terms and conditions | |
e9fc2aa0 | 7 | * of the GNU General Public License version 2. |
b3b94faa DT |
8 | */ |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/sort.h> | |
17 | #include <linux/jhash.h> | |
d0dc80db | 18 | #include <linux/kallsyms.h> |
5c676f6d | 19 | #include <linux/gfs2_ondisk.h> |
24264434 | 20 | #include <linux/list.h> |
7d308590 | 21 | #include <linux/lm_interface.h> |
fee852e3 | 22 | #include <linux/wait.h> |
95d97b7d | 23 | #include <linux/module.h> |
61be084e | 24 | #include <linux/rwsem.h> |
b3b94faa | 25 | #include <asm/uaccess.h> |
7c52b166 RP |
26 | #include <linux/seq_file.h> |
27 | #include <linux/debugfs.h> | |
8fbbfd21 SW |
28 | #include <linux/kthread.h> |
29 | #include <linux/freezer.h> | |
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)); |
190562bd | 220 | BUG_ON(spin_is_locked(&gl->gl_spin)); |
16feb9fe SW |
221 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); |
222 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
223 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
224 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
16feb9fe | 225 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); |
b3b94faa DT |
226 | glock_free(gl); |
227 | rv = 1; | |
228 | goto out; | |
229 | } | |
087efdd3 | 230 | write_unlock(gl_lock_addr(gl->gl_hash)); |
a2242db0 | 231 | out: |
b3b94faa DT |
232 | return rv; |
233 | } | |
234 | ||
b3b94faa DT |
235 | /** |
236 | * search_bucket() - Find struct gfs2_glock by lock number | |
237 | * @bucket: the bucket to search | |
238 | * @name: The lock name | |
239 | * | |
240 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
241 | */ | |
242 | ||
37b2fa6a | 243 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 244 | const struct gfs2_sbd *sdp, |
d6a53727 | 245 | const struct lm_lockname *name) |
b3b94faa DT |
246 | { |
247 | struct gfs2_glock *gl; | |
b6397893 | 248 | struct hlist_node *h; |
b3b94faa | 249 | |
b6397893 | 250 | hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { |
b3b94faa DT |
251 | if (!lm_name_equal(&gl->gl_name, name)) |
252 | continue; | |
899be4d3 SW |
253 | if (gl->gl_sbd != sdp) |
254 | continue; | |
b3b94faa | 255 | |
16feb9fe | 256 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
257 | |
258 | return gl; | |
259 | } | |
260 | ||
261 | return NULL; | |
262 | } | |
263 | ||
264 | /** | |
265 | * gfs2_glock_find() - Find glock by lock number | |
266 | * @sdp: The GFS2 superblock | |
267 | * @name: The lock name | |
268 | * | |
269 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
270 | */ | |
271 | ||
85d1da67 | 272 | static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, |
d6a53727 | 273 | const struct lm_lockname *name) |
b3b94faa | 274 | { |
37b2fa6a | 275 | unsigned int hash = gl_hash(sdp, name); |
b3b94faa DT |
276 | struct gfs2_glock *gl; |
277 | ||
087efdd3 | 278 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 279 | gl = search_bucket(hash, sdp, name); |
087efdd3 | 280 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
281 | |
282 | return gl; | |
283 | } | |
284 | ||
c4f68a13 BM |
285 | static void glock_work_func(struct work_struct *work) |
286 | { | |
287 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); | |
288 | ||
289 | spin_lock(&gl->gl_spin); | |
290 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags)) | |
291 | set_bit(GLF_DEMOTE, &gl->gl_flags); | |
292 | run_queue(gl); | |
293 | spin_unlock(&gl->gl_spin); | |
294 | gfs2_glock_put(gl); | |
295 | } | |
296 | ||
b3b94faa DT |
297 | /** |
298 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
299 | * @sdp: The GFS2 superblock | |
300 | * @number: the lock number | |
301 | * @glops: The glock_operations to use | |
302 | * @create: If 0, don't create the glock if it doesn't exist | |
303 | * @glp: the glock is returned here | |
304 | * | |
305 | * This does not lock a glock, just finds/creates structures for one. | |
306 | * | |
307 | * Returns: errno | |
308 | */ | |
309 | ||
cd915493 | 310 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 311 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
312 | struct gfs2_glock **glp) |
313 | { | |
37b2fa6a | 314 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 315 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 316 | unsigned int hash = gl_hash(sdp, &name); |
b3b94faa DT |
317 | int error; |
318 | ||
087efdd3 | 319 | read_lock(gl_lock_addr(hash)); |
37b2fa6a | 320 | gl = search_bucket(hash, sdp, &name); |
087efdd3 | 321 | read_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
322 | |
323 | if (gl || !create) { | |
324 | *glp = gl; | |
325 | return 0; | |
326 | } | |
327 | ||
328 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
329 | if (!gl) | |
330 | return -ENOMEM; | |
331 | ||
ec45d9f5 | 332 | gl->gl_flags = 0; |
b3b94faa | 333 | gl->gl_name = name; |
16feb9fe | 334 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 335 | gl->gl_state = LM_ST_UNLOCKED; |
c4f68a13 | 336 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 337 | gl->gl_hash = hash; |
04b933f2 | 338 | gl->gl_owner_pid = 0; |
320dd101 | 339 | gl->gl_ip = 0; |
b3b94faa | 340 | gl->gl_ops = glops; |
ec45d9f5 SW |
341 | gl->gl_req_gh = NULL; |
342 | gl->gl_req_bh = NULL; | |
343 | gl->gl_vn = 0; | |
344 | gl->gl_stamp = jiffies; | |
c4f68a13 | 345 | gl->gl_tchange = jiffies; |
ec45d9f5 | 346 | gl->gl_object = NULL; |
b3b94faa | 347 | gl->gl_sbd = sdp; |
ec45d9f5 | 348 | gl->gl_aspace = NULL; |
b3b94faa | 349 | lops_init_le(&gl->gl_le, &gfs2_glock_lops); |
c4f68a13 | 350 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b3b94faa DT |
351 | |
352 | /* If this glock protects actual on-disk data or metadata blocks, | |
353 | create a VFS inode to manage the pages/buffers holding them. */ | |
50299965 | 354 | if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) { |
b3b94faa DT |
355 | gl->gl_aspace = gfs2_aspace_get(sdp); |
356 | if (!gl->gl_aspace) { | |
357 | error = -ENOMEM; | |
358 | goto fail; | |
359 | } | |
360 | } | |
361 | ||
362 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
363 | if (error) | |
364 | goto fail_aspace; | |
365 | ||
087efdd3 | 366 | write_lock(gl_lock_addr(hash)); |
37b2fa6a | 367 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 368 | if (tmp) { |
087efdd3 | 369 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
370 | glock_free(gl); |
371 | gl = tmp; | |
372 | } else { | |
b6397893 | 373 | hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); |
087efdd3 | 374 | write_unlock(gl_lock_addr(hash)); |
b3b94faa DT |
375 | } |
376 | ||
377 | *glp = gl; | |
378 | ||
379 | return 0; | |
380 | ||
ec45d9f5 | 381 | fail_aspace: |
b3b94faa DT |
382 | if (gl->gl_aspace) |
383 | gfs2_aspace_put(gl->gl_aspace); | |
ec45d9f5 | 384 | fail: |
907b9bce | 385 | kmem_cache_free(gfs2_glock_cachep, gl); |
b3b94faa DT |
386 | return error; |
387 | } | |
388 | ||
389 | /** | |
390 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
391 | * @gl: the glock | |
392 | * @state: the state we're requesting | |
393 | * @flags: the modifier flags | |
394 | * @gh: the holder structure | |
395 | * | |
396 | */ | |
397 | ||
190562bd | 398 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
399 | struct gfs2_holder *gh) |
400 | { | |
401 | INIT_LIST_HEAD(&gh->gh_list); | |
402 | gh->gh_gl = gl; | |
d0dc80db | 403 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
04b933f2 | 404 | gh->gh_owner_pid = current->pid; |
b3b94faa DT |
405 | gh->gh_state = state; |
406 | gh->gh_flags = flags; | |
407 | gh->gh_error = 0; | |
408 | gh->gh_iflags = 0; | |
b3b94faa DT |
409 | gfs2_glock_hold(gl); |
410 | } | |
411 | ||
412 | /** | |
413 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
414 | * @state: the state we're requesting | |
415 | * @flags: the modifier flags | |
416 | * @gh: the holder structure | |
417 | * | |
418 | * Don't mess with the glock. | |
419 | * | |
420 | */ | |
421 | ||
190562bd | 422 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
423 | { |
424 | gh->gh_state = state; | |
579b78a4 | 425 | gh->gh_flags = flags; |
3b8249f6 | 426 | gh->gh_iflags = 0; |
d0dc80db | 427 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
428 | } |
429 | ||
430 | /** | |
431 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
432 | * @gh: the holder structure | |
433 | * | |
434 | */ | |
435 | ||
436 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
437 | { | |
438 | gfs2_glock_put(gh->gh_gl); | |
439 | gh->gh_gl = NULL; | |
d0dc80db | 440 | gh->gh_ip = 0; |
b3b94faa DT |
441 | } |
442 | ||
3b8249f6 | 443 | static void gfs2_holder_wake(struct gfs2_holder *gh) |
fee852e3 | 444 | { |
fee852e3 | 445 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
d93cfa98 | 446 | smp_mb__after_clear_bit(); |
fee852e3 SW |
447 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); |
448 | } | |
449 | ||
d93cfa98 | 450 | static int just_schedule(void *word) |
fee852e3 SW |
451 | { |
452 | schedule(); | |
453 | return 0; | |
454 | } | |
455 | ||
456 | static void wait_on_holder(struct gfs2_holder *gh) | |
457 | { | |
458 | might_sleep(); | |
d93cfa98 AD |
459 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE); |
460 | } | |
461 | ||
462 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
463 | { | |
c4f68a13 BM |
464 | BUG_ON(!spin_is_locked(&gl->gl_spin)); |
465 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
d93cfa98 AD |
466 | clear_bit(GLF_DEMOTE, &gl->gl_flags); |
467 | smp_mb__after_clear_bit(); | |
468 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
469 | } | |
470 | ||
471 | static void wait_on_demote(struct gfs2_glock *gl) | |
472 | { | |
473 | might_sleep(); | |
474 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE); | |
fee852e3 SW |
475 | } |
476 | ||
b3b94faa DT |
477 | /** |
478 | * rq_mutex - process a mutex request in the queue | |
479 | * @gh: the glock holder | |
480 | * | |
481 | * Returns: 1 if the queue is blocked | |
482 | */ | |
483 | ||
484 | static int rq_mutex(struct gfs2_holder *gh) | |
485 | { | |
486 | struct gfs2_glock *gl = gh->gh_gl; | |
487 | ||
488 | list_del_init(&gh->gh_list); | |
489 | /* gh->gh_error never examined. */ | |
490 | set_bit(GLF_LOCK, &gl->gl_flags); | |
d043e190 | 491 | clear_bit(HIF_WAIT, &gh->gh_iflags); |
fee852e3 SW |
492 | smp_mb(); |
493 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
b3b94faa DT |
494 | |
495 | return 1; | |
496 | } | |
497 | ||
498 | /** | |
499 | * rq_promote - process a promote request in the queue | |
500 | * @gh: the glock holder | |
501 | * | |
502 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
503 | * | |
504 | * Returns: 1 if the queue is blocked | |
505 | */ | |
506 | ||
507 | static int rq_promote(struct gfs2_holder *gh) | |
508 | { | |
509 | struct gfs2_glock *gl = gh->gh_gl; | |
510 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa DT |
511 | |
512 | if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
513 | if (list_empty(&gl->gl_holders)) { | |
514 | gl->gl_req_gh = gh; | |
515 | set_bit(GLF_LOCK, &gl->gl_flags); | |
516 | spin_unlock(&gl->gl_spin); | |
517 | ||
518 | if (atomic_read(&sdp->sd_reclaim_count) > | |
519 | gfs2_tune_get(sdp, gt_reclaim_limit) && | |
520 | !(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
521 | gfs2_reclaim_glock(sdp); | |
522 | gfs2_reclaim_glock(sdp); | |
523 | } | |
524 | ||
3b8249f6 | 525 | gfs2_glock_xmote_th(gh->gh_gl, gh); |
b3b94faa DT |
526 | spin_lock(&gl->gl_spin); |
527 | } | |
528 | return 1; | |
529 | } | |
530 | ||
531 | if (list_empty(&gl->gl_holders)) { | |
532 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
533 | set_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
534 | } else { |
535 | struct gfs2_holder *next_gh; | |
1c0f4872 | 536 | if (gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa DT |
537 | return 1; |
538 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
539 | gh_list); | |
1c0f4872 | 540 | if (next_gh->gh_state == LM_ST_EXCLUSIVE) |
b3b94faa | 541 | return 1; |
b3b94faa DT |
542 | } |
543 | ||
544 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
545 | gh->gh_error = 0; | |
546 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
547 | ||
3b8249f6 | 548 | gfs2_holder_wake(gh); |
b3b94faa DT |
549 | |
550 | return 0; | |
551 | } | |
552 | ||
553 | /** | |
554 | * rq_demote - process a demote request in the queue | |
555 | * @gh: the glock holder | |
556 | * | |
557 | * Returns: 1 if the queue is blocked | |
558 | */ | |
559 | ||
3b8249f6 | 560 | static int rq_demote(struct gfs2_glock *gl) |
b3b94faa | 561 | { |
b3b94faa DT |
562 | if (!list_empty(&gl->gl_holders)) |
563 | return 1; | |
564 | ||
3b8249f6 SW |
565 | if (gl->gl_state == gl->gl_demote_state || |
566 | gl->gl_state == LM_ST_UNLOCKED) { | |
d93cfa98 | 567 | gfs2_demote_wake(gl); |
3b8249f6 | 568 | return 0; |
b3b94faa | 569 | } |
3b8249f6 | 570 | set_bit(GLF_LOCK, &gl->gl_flags); |
3b8249f6 | 571 | if (gl->gl_demote_state == LM_ST_UNLOCKED || |
87124e58 SW |
572 | gl->gl_state != LM_ST_EXCLUSIVE) { |
573 | spin_unlock(&gl->gl_spin); | |
3b8249f6 | 574 | gfs2_glock_drop_th(gl); |
87124e58 SW |
575 | } else { |
576 | spin_unlock(&gl->gl_spin); | |
3b8249f6 | 577 | gfs2_glock_xmote_th(gl, NULL); |
87124e58 | 578 | } |
3b8249f6 | 579 | spin_lock(&gl->gl_spin); |
b3b94faa DT |
580 | |
581 | return 0; | |
582 | } | |
583 | ||
b3b94faa DT |
584 | /** |
585 | * run_queue - process holder structures on a glock | |
586 | * @gl: the glock | |
587 | * | |
588 | */ | |
b3b94faa DT |
589 | static void run_queue(struct gfs2_glock *gl) |
590 | { | |
591 | struct gfs2_holder *gh; | |
592 | int blocked = 1; | |
593 | ||
594 | for (;;) { | |
595 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
596 | break; | |
597 | ||
598 | if (!list_empty(&gl->gl_waiters1)) { | |
599 | gh = list_entry(gl->gl_waiters1.next, | |
600 | struct gfs2_holder, gh_list); | |
601 | ||
602 | if (test_bit(HIF_MUTEX, &gh->gh_iflags)) | |
603 | blocked = rq_mutex(gh); | |
604 | else | |
605 | gfs2_assert_warn(gl->gl_sbd, 0); | |
606 | ||
3b8249f6 SW |
607 | } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
608 | blocked = rq_demote(gl); | |
b3b94faa DT |
609 | } else if (!list_empty(&gl->gl_waiters3)) { |
610 | gh = list_entry(gl->gl_waiters3.next, | |
611 | struct gfs2_holder, gh_list); | |
612 | ||
613 | if (test_bit(HIF_PROMOTE, &gh->gh_iflags)) | |
614 | blocked = rq_promote(gh); | |
615 | else | |
616 | gfs2_assert_warn(gl->gl_sbd, 0); | |
617 | ||
618 | } else | |
619 | break; | |
620 | ||
621 | if (blocked) | |
622 | break; | |
623 | } | |
624 | } | |
625 | ||
626 | /** | |
627 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
628 | * @gl: the glock | |
629 | * | |
630 | * Gives caller exclusive access to manipulate a glock structure. | |
631 | */ | |
632 | ||
feaa7bba | 633 | static void gfs2_glmutex_lock(struct gfs2_glock *gl) |
b3b94faa DT |
634 | { |
635 | struct gfs2_holder gh; | |
636 | ||
637 | gfs2_holder_init(gl, 0, 0, &gh); | |
638 | set_bit(HIF_MUTEX, &gh.gh_iflags); | |
fee852e3 SW |
639 | if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags)) |
640 | BUG(); | |
b3b94faa DT |
641 | |
642 | spin_lock(&gl->gl_spin); | |
85d1da67 | 643 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 644 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); |
85d1da67 | 645 | } else { |
04b933f2 | 646 | gl->gl_owner_pid = current->pid; |
320dd101 | 647 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
fee852e3 SW |
648 | clear_bit(HIF_WAIT, &gh.gh_iflags); |
649 | smp_mb(); | |
650 | wake_up_bit(&gh.gh_iflags, HIF_WAIT); | |
320dd101 | 651 | } |
b3b94faa DT |
652 | spin_unlock(&gl->gl_spin); |
653 | ||
fee852e3 | 654 | wait_on_holder(&gh); |
b3b94faa DT |
655 | gfs2_holder_uninit(&gh); |
656 | } | |
657 | ||
658 | /** | |
659 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
660 | * @gl: the glock | |
661 | * | |
662 | * Returns: 1 if the glock is acquired | |
663 | */ | |
664 | ||
08bc2dbc | 665 | static int gfs2_glmutex_trylock(struct gfs2_glock *gl) |
b3b94faa DT |
666 | { |
667 | int acquired = 1; | |
668 | ||
669 | spin_lock(&gl->gl_spin); | |
85d1da67 | 670 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
b3b94faa | 671 | acquired = 0; |
85d1da67 | 672 | } else { |
04b933f2 | 673 | gl->gl_owner_pid = current->pid; |
320dd101 SW |
674 | gl->gl_ip = (unsigned long)__builtin_return_address(0); |
675 | } | |
b3b94faa DT |
676 | spin_unlock(&gl->gl_spin); |
677 | ||
678 | return acquired; | |
679 | } | |
680 | ||
681 | /** | |
682 | * gfs2_glmutex_unlock - release a local lock on a glock | |
683 | * @gl: the glock | |
684 | * | |
685 | */ | |
686 | ||
feaa7bba | 687 | static void gfs2_glmutex_unlock(struct gfs2_glock *gl) |
b3b94faa DT |
688 | { |
689 | spin_lock(&gl->gl_spin); | |
690 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
04b933f2 | 691 | gl->gl_owner_pid = 0; |
320dd101 | 692 | gl->gl_ip = 0; |
b3b94faa | 693 | run_queue(gl); |
190562bd | 694 | BUG_ON(!spin_is_locked(&gl->gl_spin)); |
b3b94faa DT |
695 | spin_unlock(&gl->gl_spin); |
696 | } | |
697 | ||
698 | /** | |
3b8249f6 | 699 | * handle_callback - process a demote request |
b3b94faa DT |
700 | * @gl: the glock |
701 | * @state: the state the caller wants us to change to | |
702 | * | |
3b8249f6 SW |
703 | * There are only two requests that we are going to see in actual |
704 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
705 | */ |
706 | ||
c4f68a13 BM |
707 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
708 | int remote, unsigned long delay) | |
b3b94faa | 709 | { |
c4f68a13 BM |
710 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
711 | ||
b3b94faa | 712 | spin_lock(&gl->gl_spin); |
c4f68a13 BM |
713 | set_bit(bit, &gl->gl_flags); |
714 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
3b8249f6 SW |
715 | gl->gl_demote_state = state; |
716 | gl->gl_demote_time = jiffies; | |
d93cfa98 AD |
717 | if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN && |
718 | gl->gl_object) { | |
49e61f2e | 719 | gfs2_glock_schedule_for_reclaim(gl); |
d93cfa98 | 720 | spin_unlock(&gl->gl_spin); |
d93cfa98 AD |
721 | return; |
722 | } | |
26caee5b JW |
723 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
724 | gl->gl_demote_state != state) { | |
725 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 726 | } |
b3b94faa | 727 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
728 | } |
729 | ||
730 | /** | |
731 | * state_change - record that the glock is now in a different state | |
732 | * @gl: the glock | |
733 | * @new_state the new state | |
734 | * | |
735 | */ | |
736 | ||
737 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
738 | { | |
b3b94faa DT |
739 | int held1, held2; |
740 | ||
741 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
742 | held2 = (new_state != LM_ST_UNLOCKED); | |
743 | ||
744 | if (held1 != held2) { | |
6a6b3d01 | 745 | if (held2) |
b3b94faa | 746 | gfs2_glock_hold(gl); |
6a6b3d01 | 747 | else |
b3b94faa | 748 | gfs2_glock_put(gl); |
b3b94faa DT |
749 | } |
750 | ||
751 | gl->gl_state = new_state; | |
c4f68a13 | 752 | gl->gl_tchange = jiffies; |
b3b94faa DT |
753 | } |
754 | ||
755 | /** | |
756 | * xmote_bh - Called after the lock module is done acquiring a lock | |
757 | * @gl: The glock in question | |
758 | * @ret: the int returned from the lock module | |
759 | * | |
760 | */ | |
761 | ||
762 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
763 | { | |
764 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 765 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
766 | struct gfs2_holder *gh = gl->gl_req_gh; |
767 | int prev_state = gl->gl_state; | |
768 | int op_done = 1; | |
769 | ||
770 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
12132933 | 771 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
772 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); |
773 | ||
774 | state_change(gl, ret & LM_OUT_ST_MASK); | |
775 | ||
776 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
777 | if (glops->go_inval) | |
1a14d3a6 | 778 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
779 | } else if (gl->gl_state == LM_ST_DEFERRED) { |
780 | /* We might not want to do this here. | |
781 | Look at moving to the inode glops. */ | |
782 | if (glops->go_inval) | |
1a14d3a6 | 783 | glops->go_inval(gl, 0); |
b3b94faa DT |
784 | } |
785 | ||
786 | /* Deal with each possible exit condition */ | |
787 | ||
3b8249f6 | 788 | if (!gh) { |
b3b94faa | 789 | gl->gl_stamp = jiffies; |
87124e58 | 790 | if (ret & LM_OUT_CANCELED) { |
3b8249f6 | 791 | op_done = 0; |
87124e58 SW |
792 | } else { |
793 | spin_lock(&gl->gl_spin); | |
794 | if (gl->gl_state != gl->gl_demote_state) { | |
795 | gl->gl_req_bh = NULL; | |
796 | spin_unlock(&gl->gl_spin); | |
797 | gfs2_glock_drop_th(gl); | |
798 | gfs2_glock_put(gl); | |
799 | return; | |
800 | } | |
d93cfa98 | 801 | gfs2_demote_wake(gl); |
87124e58 SW |
802 | spin_unlock(&gl->gl_spin); |
803 | } | |
3b8249f6 | 804 | } else { |
b3b94faa DT |
805 | spin_lock(&gl->gl_spin); |
806 | list_del_init(&gh->gh_list); | |
807 | gh->gh_error = -EIO; | |
3b8249f6 SW |
808 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
809 | goto out; | |
810 | gh->gh_error = GLR_CANCELED; | |
811 | if (ret & LM_OUT_CANCELED) | |
812 | goto out; | |
813 | if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
814 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
b3b94faa | 815 | gh->gh_error = 0; |
3b8249f6 SW |
816 | set_bit(HIF_HOLDER, &gh->gh_iflags); |
817 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
818 | op_done = 0; | |
819 | goto out; | |
b3b94faa | 820 | } |
b3b94faa | 821 | gh->gh_error = GLR_TRYFAILED; |
3b8249f6 SW |
822 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
823 | goto out; | |
824 | gh->gh_error = -EINVAL; | |
b3b94faa DT |
825 | if (gfs2_assert_withdraw(sdp, 0) == -1) |
826 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
3b8249f6 SW |
827 | out: |
828 | spin_unlock(&gl->gl_spin); | |
b3b94faa DT |
829 | } |
830 | ||
831 | if (glops->go_xmote_bh) | |
832 | glops->go_xmote_bh(gl); | |
833 | ||
834 | if (op_done) { | |
835 | spin_lock(&gl->gl_spin); | |
836 | gl->gl_req_gh = NULL; | |
837 | gl->gl_req_bh = NULL; | |
838 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
839 | spin_unlock(&gl->gl_spin); |
840 | } | |
841 | ||
842 | gfs2_glock_put(gl); | |
843 | ||
fee852e3 | 844 | if (gh) |
3b8249f6 | 845 | gfs2_holder_wake(gh); |
b3b94faa DT |
846 | } |
847 | ||
848 | /** | |
849 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
850 | * @gl: The glock in question | |
851 | * @state: the requested state | |
852 | * @flags: modifier flags to the lock call | |
853 | * | |
854 | */ | |
855 | ||
87124e58 | 856 | static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh) |
b3b94faa DT |
857 | { |
858 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
3b8249f6 SW |
859 | int flags = gh ? gh->gh_flags : 0; |
860 | unsigned state = gh ? gh->gh_state : gl->gl_demote_state; | |
8fb4b536 | 861 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
862 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | |
863 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
864 | LM_FLAG_PRIORITY); | |
865 | unsigned int lck_ret; | |
866 | ||
b5d32bea SW |
867 | if (glops->go_xmote_th) |
868 | glops->go_xmote_th(gl); | |
869 | ||
b3b94faa | 870 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 871 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
872 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); |
873 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
874 | ||
b3b94faa DT |
875 | gfs2_glock_hold(gl); |
876 | gl->gl_req_bh = xmote_bh; | |
877 | ||
ec45d9f5 | 878 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); |
b3b94faa DT |
879 | |
880 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
881 | return; | |
882 | ||
883 | if (lck_ret & LM_OUT_ASYNC) | |
884 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
885 | else | |
886 | xmote_bh(gl, lck_ret); | |
887 | } | |
888 | ||
889 | /** | |
890 | * drop_bh - Called after a lock module unlock completes | |
891 | * @gl: the glock | |
892 | * @ret: the return status | |
893 | * | |
894 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
895 | * Doesn't drop the reference on the glock the top half took out | |
896 | * | |
897 | */ | |
898 | ||
899 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
900 | { | |
901 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 902 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
903 | struct gfs2_holder *gh = gl->gl_req_gh; |
904 | ||
b3b94faa | 905 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 906 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
907 | gfs2_assert_warn(sdp, !ret); |
908 | ||
909 | state_change(gl, LM_ST_UNLOCKED); | |
910 | ||
911 | if (glops->go_inval) | |
1a14d3a6 | 912 | glops->go_inval(gl, DIO_METADATA); |
b3b94faa DT |
913 | |
914 | if (gh) { | |
915 | spin_lock(&gl->gl_spin); | |
916 | list_del_init(&gh->gh_list); | |
917 | gh->gh_error = 0; | |
918 | spin_unlock(&gl->gl_spin); | |
919 | } | |
920 | ||
b3b94faa | 921 | spin_lock(&gl->gl_spin); |
c4f68a13 | 922 | gfs2_demote_wake(gl); |
b3b94faa DT |
923 | gl->gl_req_gh = NULL; |
924 | gl->gl_req_bh = NULL; | |
925 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
926 | spin_unlock(&gl->gl_spin); |
927 | ||
928 | gfs2_glock_put(gl); | |
929 | ||
fee852e3 | 930 | if (gh) |
3b8249f6 | 931 | gfs2_holder_wake(gh); |
b3b94faa DT |
932 | } |
933 | ||
934 | /** | |
935 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
936 | * @gl: the glock | |
937 | * | |
938 | */ | |
939 | ||
b5d32bea | 940 | static void gfs2_glock_drop_th(struct gfs2_glock *gl) |
b3b94faa DT |
941 | { |
942 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 943 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
944 | unsigned int ret; |
945 | ||
b5d32bea SW |
946 | if (glops->go_drop_th) |
947 | glops->go_drop_th(gl); | |
948 | ||
b3b94faa | 949 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); |
12132933 | 950 | gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); |
b3b94faa DT |
951 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); |
952 | ||
b3b94faa DT |
953 | gfs2_glock_hold(gl); |
954 | gl->gl_req_bh = drop_bh; | |
955 | ||
b3b94faa DT |
956 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
957 | ||
958 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
959 | return; | |
960 | ||
961 | if (!ret) | |
962 | drop_bh(gl, ret); | |
963 | else | |
964 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
965 | } | |
966 | ||
967 | /** | |
968 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
969 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
970 | * | |
971 | * Don't cancel GL_NOCANCEL requests. | |
972 | */ | |
973 | ||
974 | static void do_cancels(struct gfs2_holder *gh) | |
975 | { | |
976 | struct gfs2_glock *gl = gh->gh_gl; | |
977 | ||
978 | spin_lock(&gl->gl_spin); | |
979 | ||
980 | while (gl->gl_req_gh != gh && | |
981 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
982 | !list_empty(&gh->gh_list)) { | |
50299965 SW |
983 | if (gl->gl_req_bh && !(gl->gl_req_gh && |
984 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
b3b94faa DT |
985 | spin_unlock(&gl->gl_spin); |
986 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
987 | msleep(100); | |
988 | spin_lock(&gl->gl_spin); | |
989 | } else { | |
990 | spin_unlock(&gl->gl_spin); | |
991 | msleep(100); | |
992 | spin_lock(&gl->gl_spin); | |
993 | } | |
994 | } | |
995 | ||
996 | spin_unlock(&gl->gl_spin); | |
997 | } | |
998 | ||
999 | /** | |
1000 | * glock_wait_internal - wait on a glock acquisition | |
1001 | * @gh: the glock holder | |
1002 | * | |
1003 | * Returns: 0 on success | |
1004 | */ | |
1005 | ||
1006 | static int glock_wait_internal(struct gfs2_holder *gh) | |
1007 | { | |
1008 | struct gfs2_glock *gl = gh->gh_gl; | |
1009 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
8fb4b536 | 1010 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1011 | |
1012 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
1013 | return -EIO; | |
1014 | ||
1015 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
1016 | spin_lock(&gl->gl_spin); | |
1017 | if (gl->gl_req_gh != gh && | |
1018 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1019 | !list_empty(&gh->gh_list)) { | |
1020 | list_del_init(&gh->gh_list); | |
1021 | gh->gh_error = GLR_TRYFAILED; | |
b3b94faa DT |
1022 | run_queue(gl); |
1023 | spin_unlock(&gl->gl_spin); | |
1024 | return gh->gh_error; | |
1025 | } | |
1026 | spin_unlock(&gl->gl_spin); | |
1027 | } | |
1028 | ||
1029 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1030 | do_cancels(gh); | |
1031 | ||
fee852e3 | 1032 | wait_on_holder(gh); |
b3b94faa DT |
1033 | if (gh->gh_error) |
1034 | return gh->gh_error; | |
1035 | ||
1036 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
85d1da67 | 1037 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, |
b3b94faa DT |
1038 | gh->gh_flags)); |
1039 | ||
1040 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
1041 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1042 | ||
1043 | if (glops->go_lock) { | |
1044 | gh->gh_error = glops->go_lock(gh); | |
1045 | if (gh->gh_error) { | |
1046 | spin_lock(&gl->gl_spin); | |
1047 | list_del_init(&gh->gh_list); | |
b3b94faa DT |
1048 | spin_unlock(&gl->gl_spin); |
1049 | } | |
1050 | } | |
1051 | ||
1052 | spin_lock(&gl->gl_spin); | |
1053 | gl->gl_req_gh = NULL; | |
1054 | gl->gl_req_bh = NULL; | |
1055 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa DT |
1056 | run_queue(gl); |
1057 | spin_unlock(&gl->gl_spin); | |
1058 | } | |
1059 | ||
1060 | return gh->gh_error; | |
1061 | } | |
1062 | ||
1063 | static inline struct gfs2_holder * | |
04b933f2 | 1064 | find_holder_by_owner(struct list_head *head, pid_t pid) |
b3b94faa DT |
1065 | { |
1066 | struct gfs2_holder *gh; | |
1067 | ||
1068 | list_for_each_entry(gh, head, gh_list) { | |
04b933f2 | 1069 | if (gh->gh_owner_pid == pid) |
b3b94faa DT |
1070 | return gh; |
1071 | } | |
1072 | ||
1073 | return NULL; | |
1074 | } | |
1075 | ||
7c52b166 RP |
1076 | static void print_dbg(struct glock_iter *gi, const char *fmt, ...) |
1077 | { | |
1078 | va_list args; | |
1079 | ||
1080 | va_start(args, fmt); | |
1081 | if (gi) { | |
1082 | vsprintf(gi->string, fmt, args); | |
1083 | seq_printf(gi->seq, gi->string); | |
1084 | } | |
1085 | else | |
1086 | vprintk(fmt, args); | |
1087 | va_end(args); | |
1088 | } | |
1089 | ||
b3b94faa DT |
1090 | /** |
1091 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1092 | * @gh: the holder structure to add | |
1093 | * | |
1094 | */ | |
1095 | ||
1096 | static void add_to_queue(struct gfs2_holder *gh) | |
1097 | { | |
1098 | struct gfs2_glock *gl = gh->gh_gl; | |
1099 | struct gfs2_holder *existing; | |
1100 | ||
04b933f2 | 1101 | BUG_ON(!gh->gh_owner_pid); |
fee852e3 SW |
1102 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
1103 | BUG(); | |
190562bd | 1104 | |
b4c20166 AD |
1105 | if (!(gh->gh_flags & GL_FLOCK)) { |
1106 | existing = find_holder_by_owner(&gl->gl_holders, | |
1107 | gh->gh_owner_pid); | |
1108 | if (existing) { | |
1109 | print_symbol(KERN_WARNING "original: %s\n", | |
1110 | existing->gh_ip); | |
1111 | printk(KERN_INFO "pid : %d\n", existing->gh_owner_pid); | |
1112 | printk(KERN_INFO "lock type : %d lock state : %d\n", | |
1113 | existing->gh_gl->gl_name.ln_type, | |
1114 | existing->gh_gl->gl_state); | |
1115 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1116 | printk(KERN_INFO "pid : %d\n", gh->gh_owner_pid); | |
1117 | printk(KERN_INFO "lock type : %d lock state : %d\n", | |
1118 | gl->gl_name.ln_type, gl->gl_state); | |
1119 | BUG(); | |
1120 | } | |
1121 | ||
1122 | existing = find_holder_by_owner(&gl->gl_waiters3, | |
1123 | gh->gh_owner_pid); | |
1124 | if (existing) { | |
1125 | print_symbol(KERN_WARNING "original: %s\n", | |
1126 | existing->gh_ip); | |
1127 | print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); | |
1128 | BUG(); | |
1129 | } | |
b3b94faa DT |
1130 | } |
1131 | ||
b3b94faa DT |
1132 | if (gh->gh_flags & LM_FLAG_PRIORITY) |
1133 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1134 | else | |
907b9bce | 1135 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); |
b3b94faa DT |
1136 | } |
1137 | ||
1138 | /** | |
1139 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1140 | * @gh: the holder structure | |
1141 | * | |
1142 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1143 | * | |
1144 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1145 | */ | |
1146 | ||
1147 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1148 | { | |
1149 | struct gfs2_glock *gl = gh->gh_gl; | |
1150 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1151 | int error = 0; | |
1152 | ||
320dd101 | 1153 | restart: |
b3b94faa DT |
1154 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
1155 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1156 | return -EIO; | |
1157 | } | |
1158 | ||
1159 | set_bit(HIF_PROMOTE, &gh->gh_iflags); | |
1160 | ||
1161 | spin_lock(&gl->gl_spin); | |
1162 | add_to_queue(gh); | |
1163 | run_queue(gl); | |
1164 | spin_unlock(&gl->gl_spin); | |
1165 | ||
1166 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1167 | error = glock_wait_internal(gh); | |
1168 | if (error == GLR_CANCELED) { | |
190562bd | 1169 | msleep(100); |
b3b94faa DT |
1170 | goto restart; |
1171 | } | |
1172 | } | |
1173 | ||
b3b94faa DT |
1174 | return error; |
1175 | } | |
1176 | ||
1177 | /** | |
1178 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1179 | * @gh: the holder | |
1180 | * | |
1181 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1182 | */ | |
1183 | ||
1184 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1185 | { | |
1186 | struct gfs2_glock *gl = gh->gh_gl; | |
1187 | int ready = 0; | |
1188 | ||
1189 | spin_lock(&gl->gl_spin); | |
1190 | ||
1191 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1192 | ready = 1; | |
1193 | else if (list_empty(&gh->gh_list)) { | |
1194 | if (gh->gh_error == GLR_CANCELED) { | |
1195 | spin_unlock(&gl->gl_spin); | |
190562bd | 1196 | msleep(100); |
b3b94faa DT |
1197 | if (gfs2_glock_nq(gh)) |
1198 | return 1; | |
1199 | return 0; | |
1200 | } else | |
1201 | ready = 1; | |
1202 | } | |
1203 | ||
1204 | spin_unlock(&gl->gl_spin); | |
1205 | ||
1206 | return ready; | |
1207 | } | |
1208 | ||
1209 | /** | |
1210 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1211 | * @gh: the holder structure | |
1212 | * | |
1213 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1214 | */ | |
1215 | ||
1216 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1217 | { | |
1218 | int error; | |
1219 | ||
1220 | error = glock_wait_internal(gh); | |
1221 | if (error == GLR_CANCELED) { | |
190562bd | 1222 | msleep(100); |
b3b94faa DT |
1223 | gh->gh_flags &= ~GL_ASYNC; |
1224 | error = gfs2_glock_nq(gh); | |
1225 | } | |
1226 | ||
1227 | return error; | |
1228 | } | |
1229 | ||
1230 | /** | |
1231 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1232 | * @gh: the glock holder | |
1233 | * | |
1234 | */ | |
1235 | ||
1236 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1237 | { | |
1238 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1239 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1240 | unsigned delay = 0; |
b3b94faa | 1241 | |
b3b94faa | 1242 | if (gh->gh_flags & GL_NOCACHE) |
c4f68a13 | 1243 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa DT |
1244 | |
1245 | gfs2_glmutex_lock(gl); | |
1246 | ||
1247 | spin_lock(&gl->gl_spin); | |
1248 | list_del_init(&gh->gh_list); | |
1249 | ||
1250 | if (list_empty(&gl->gl_holders)) { | |
1251 | spin_unlock(&gl->gl_spin); | |
1252 | ||
1253 | if (glops->go_unlock) | |
1254 | glops->go_unlock(gh); | |
1255 | ||
b3b94faa | 1256 | spin_lock(&gl->gl_spin); |
3b8249f6 | 1257 | gl->gl_stamp = jiffies; |
b3b94faa DT |
1258 | } |
1259 | ||
1260 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
b3b94faa | 1261 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1262 | |
1263 | gfs2_glock_hold(gl); | |
1264 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1265 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1266 | delay = gl->gl_ops->go_min_hold_time; | |
1267 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1268 | gfs2_glock_put(gl); | |
b3b94faa DT |
1269 | } |
1270 | ||
d93cfa98 AD |
1271 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1272 | { | |
1273 | struct gfs2_glock *gl = gh->gh_gl; | |
1274 | gfs2_glock_dq(gh); | |
1275 | wait_on_demote(gl); | |
1276 | } | |
1277 | ||
b3b94faa DT |
1278 | /** |
1279 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1280 | * @gh: the holder structure | |
1281 | * | |
1282 | */ | |
1283 | ||
1284 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1285 | { | |
1286 | gfs2_glock_dq(gh); | |
1287 | gfs2_holder_uninit(gh); | |
1288 | } | |
1289 | ||
1290 | /** | |
1291 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1292 | * @sdp: the filesystem | |
1293 | * @number: the lock number | |
1294 | * @glops: the glock operations for the type of glock | |
1295 | * @state: the state to acquire the glock in | |
1296 | * @flags: modifier flags for the aquisition | |
1297 | * @gh: the struct gfs2_holder | |
1298 | * | |
1299 | * Returns: errno | |
1300 | */ | |
1301 | ||
cd915493 | 1302 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1303 | const struct gfs2_glock_operations *glops, |
1304 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1305 | { |
1306 | struct gfs2_glock *gl; | |
1307 | int error; | |
1308 | ||
1309 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1310 | if (!error) { | |
1311 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1312 | gfs2_glock_put(gl); | |
1313 | } | |
1314 | ||
1315 | return error; | |
1316 | } | |
1317 | ||
1318 | /** | |
1319 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1320 | * @arg_a: the first structure | |
1321 | * @arg_b: the second structure | |
1322 | * | |
1323 | */ | |
1324 | ||
1325 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1326 | { | |
a5e08a9e SW |
1327 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1328 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1329 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1330 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1331 | |
1332 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1333 | return 1; |
1334 | if (a->ln_number < b->ln_number) | |
1335 | return -1; | |
1c0f4872 | 1336 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1337 | return 0; |
b3b94faa DT |
1338 | } |
1339 | ||
1340 | /** | |
1341 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1342 | * @num_gh: the number of structures | |
1343 | * @ghs: an array of struct gfs2_holder structures | |
1344 | * | |
1345 | * Returns: 0 on success (all glocks acquired), | |
1346 | * errno on failure (no glocks acquired) | |
1347 | */ | |
1348 | ||
1349 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1350 | struct gfs2_holder **p) | |
1351 | { | |
1352 | unsigned int x; | |
1353 | int error = 0; | |
1354 | ||
1355 | for (x = 0; x < num_gh; x++) | |
1356 | p[x] = &ghs[x]; | |
1357 | ||
1358 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1359 | ||
1360 | for (x = 0; x < num_gh; x++) { | |
1361 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1362 | ||
1363 | error = gfs2_glock_nq(p[x]); | |
1364 | if (error) { | |
1365 | while (x--) | |
1366 | gfs2_glock_dq(p[x]); | |
1367 | break; | |
1368 | } | |
1369 | } | |
1370 | ||
1371 | return error; | |
1372 | } | |
1373 | ||
1374 | /** | |
1375 | * gfs2_glock_nq_m - acquire multiple glocks | |
1376 | * @num_gh: the number of structures | |
1377 | * @ghs: an array of struct gfs2_holder structures | |
1378 | * | |
b3b94faa DT |
1379 | * |
1380 | * Returns: 0 on success (all glocks acquired), | |
1381 | * errno on failure (no glocks acquired) | |
1382 | */ | |
1383 | ||
1384 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1385 | { | |
eaf5bd3c SW |
1386 | struct gfs2_holder *tmp[4]; |
1387 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1388 | int error = 0; |
1389 | ||
eaf5bd3c SW |
1390 | switch(num_gh) { |
1391 | case 0: | |
b3b94faa | 1392 | return 0; |
eaf5bd3c | 1393 | case 1: |
b3b94faa DT |
1394 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1395 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1396 | default: |
1397 | if (num_gh <= 4) | |
b3b94faa | 1398 | break; |
eaf5bd3c SW |
1399 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1400 | if (!pph) | |
1401 | return -ENOMEM; | |
b3b94faa DT |
1402 | } |
1403 | ||
eaf5bd3c | 1404 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1405 | |
eaf5bd3c SW |
1406 | if (pph != tmp) |
1407 | kfree(pph); | |
b3b94faa DT |
1408 | |
1409 | return error; | |
1410 | } | |
1411 | ||
1412 | /** | |
1413 | * gfs2_glock_dq_m - release multiple glocks | |
1414 | * @num_gh: the number of structures | |
1415 | * @ghs: an array of struct gfs2_holder structures | |
1416 | * | |
1417 | */ | |
1418 | ||
1419 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1420 | { | |
1421 | unsigned int x; | |
1422 | ||
1423 | for (x = 0; x < num_gh; x++) | |
1424 | gfs2_glock_dq(&ghs[x]); | |
1425 | } | |
1426 | ||
1427 | /** | |
1428 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1429 | * @num_gh: the number of structures | |
1430 | * @ghs: an array of struct gfs2_holder structures | |
1431 | * | |
1432 | */ | |
1433 | ||
1434 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1435 | { | |
1436 | unsigned int x; | |
1437 | ||
1438 | for (x = 0; x < num_gh; x++) | |
1439 | gfs2_glock_dq_uninit(&ghs[x]); | |
1440 | } | |
1441 | ||
b3b94faa DT |
1442 | /** |
1443 | * gfs2_lvb_hold - attach a LVB from a glock | |
1444 | * @gl: The glock in question | |
1445 | * | |
1446 | */ | |
1447 | ||
1448 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1449 | { | |
1450 | int error; | |
1451 | ||
1452 | gfs2_glmutex_lock(gl); | |
1453 | ||
1454 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1455 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1456 | if (error) { | |
1457 | gfs2_glmutex_unlock(gl); | |
1458 | return error; | |
1459 | } | |
1460 | gfs2_glock_hold(gl); | |
1461 | } | |
1462 | atomic_inc(&gl->gl_lvb_count); | |
1463 | ||
1464 | gfs2_glmutex_unlock(gl); | |
1465 | ||
1466 | return 0; | |
1467 | } | |
1468 | ||
1469 | /** | |
1470 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1471 | * @gl: The glock in question | |
1472 | * | |
1473 | */ | |
1474 | ||
1475 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1476 | { | |
1477 | gfs2_glock_hold(gl); | |
1478 | gfs2_glmutex_lock(gl); | |
1479 | ||
1480 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1481 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1482 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1483 | gl->gl_lvb = NULL; | |
1484 | gfs2_glock_put(gl); | |
1485 | } | |
1486 | ||
1487 | gfs2_glmutex_unlock(gl); | |
1488 | gfs2_glock_put(gl); | |
1489 | } | |
1490 | ||
b3b94faa DT |
1491 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, |
1492 | unsigned int state) | |
1493 | { | |
1494 | struct gfs2_glock *gl; | |
c4f68a13 BM |
1495 | unsigned long delay = 0; |
1496 | unsigned long holdtime; | |
1497 | unsigned long now = jiffies; | |
b3b94faa DT |
1498 | |
1499 | gl = gfs2_glock_find(sdp, name); | |
1500 | if (!gl) | |
1501 | return; | |
1502 | ||
c4f68a13 BM |
1503 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
1504 | if (time_before(now, holdtime)) | |
1505 | delay = holdtime - now; | |
b3b94faa | 1506 | |
c4f68a13 BM |
1507 | handle_callback(gl, state, 1, delay); |
1508 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1509 | gfs2_glock_put(gl); | |
b3b94faa DT |
1510 | } |
1511 | ||
1512 | /** | |
1513 | * gfs2_glock_cb - Callback used by locking module | |
1c089c32 | 1514 | * @sdp: Pointer to the superblock |
b3b94faa DT |
1515 | * @type: Type of callback |
1516 | * @data: Type dependent data pointer | |
1517 | * | |
1518 | * Called by the locking module when it wants to tell us something. | |
1519 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1520 | * a journal from another client needs to be recovered. | |
1521 | */ | |
1522 | ||
9b47c11d | 1523 | void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) |
b3b94faa | 1524 | { |
9b47c11d | 1525 | struct gfs2_sbd *sdp = cb_data; |
b3b94faa | 1526 | |
b3b94faa DT |
1527 | switch (type) { |
1528 | case LM_CB_NEED_E: | |
e7f5c01c | 1529 | blocking_cb(sdp, data, LM_ST_UNLOCKED); |
b3b94faa DT |
1530 | return; |
1531 | ||
1532 | case LM_CB_NEED_D: | |
e7f5c01c | 1533 | blocking_cb(sdp, data, LM_ST_DEFERRED); |
b3b94faa DT |
1534 | return; |
1535 | ||
1536 | case LM_CB_NEED_S: | |
e7f5c01c | 1537 | blocking_cb(sdp, data, LM_ST_SHARED); |
b3b94faa DT |
1538 | return; |
1539 | ||
1540 | case LM_CB_ASYNC: { | |
e7f5c01c | 1541 | struct lm_async_cb *async = data; |
b3b94faa DT |
1542 | struct gfs2_glock *gl; |
1543 | ||
61be084e | 1544 | down_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1545 | gl = gfs2_glock_find(sdp, &async->lc_name); |
1546 | if (gfs2_assert_warn(sdp, gl)) | |
1547 | return; | |
1548 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1549 | gl->gl_req_bh(gl, async->lc_ret); | |
c4f68a13 BM |
1550 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
1551 | gfs2_glock_put(gl); | |
61be084e | 1552 | up_read(&gfs2_umount_flush_sem); |
b3b94faa DT |
1553 | return; |
1554 | } | |
1555 | ||
1556 | case LM_CB_NEED_RECOVERY: | |
1557 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1558 | if (sdp->sd_recoverd_process) | |
1559 | wake_up_process(sdp->sd_recoverd_process); | |
1560 | return; | |
1561 | ||
1562 | case LM_CB_DROPLOCKS: | |
1563 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1564 | gfs2_quota_scan(sdp); | |
1565 | return; | |
1566 | ||
1567 | default: | |
1568 | gfs2_assert_warn(sdp, 0); | |
1569 | return; | |
1570 | } | |
1571 | } | |
1572 | ||
b3b94faa DT |
1573 | /** |
1574 | * demote_ok - Check to see if it's ok to unlock a glock | |
1575 | * @gl: the glock | |
1576 | * | |
1577 | * Returns: 1 if it's ok | |
1578 | */ | |
1579 | ||
1580 | static int demote_ok(struct gfs2_glock *gl) | |
1581 | { | |
8fb4b536 | 1582 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
b3b94faa DT |
1583 | int demote = 1; |
1584 | ||
1585 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
1586 | demote = 0; | |
b3b94faa DT |
1587 | else if (glops->go_demote_ok) |
1588 | demote = glops->go_demote_ok(gl); | |
1589 | ||
1590 | return demote; | |
1591 | } | |
1592 | ||
1593 | /** | |
1594 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
1595 | * @gl: the glock | |
1596 | * | |
1597 | */ | |
1598 | ||
1599 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
1600 | { | |
1601 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1602 | ||
1603 | spin_lock(&sdp->sd_reclaim_lock); | |
1604 | if (list_empty(&gl->gl_reclaim)) { | |
1605 | gfs2_glock_hold(gl); | |
1606 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
1607 | atomic_inc(&sdp->sd_reclaim_count); | |
1608 | } | |
1609 | spin_unlock(&sdp->sd_reclaim_lock); | |
1610 | ||
1611 | wake_up(&sdp->sd_reclaim_wq); | |
1612 | } | |
1613 | ||
1614 | /** | |
1615 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
1616 | * @sdp: the filesystem | |
1617 | * | |
1618 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
1619 | * different glock and we notice that there are a lot of glocks in the | |
1620 | * reclaim list. | |
1621 | * | |
1622 | */ | |
1623 | ||
1624 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
1625 | { | |
1626 | struct gfs2_glock *gl; | |
1627 | ||
1628 | spin_lock(&sdp->sd_reclaim_lock); | |
1629 | if (list_empty(&sdp->sd_reclaim_list)) { | |
1630 | spin_unlock(&sdp->sd_reclaim_lock); | |
1631 | return; | |
1632 | } | |
1633 | gl = list_entry(sdp->sd_reclaim_list.next, | |
1634 | struct gfs2_glock, gl_reclaim); | |
1635 | list_del_init(&gl->gl_reclaim); | |
1636 | spin_unlock(&sdp->sd_reclaim_lock); | |
1637 | ||
1638 | atomic_dec(&sdp->sd_reclaim_count); | |
1639 | atomic_inc(&sdp->sd_reclaimed); | |
1640 | ||
1641 | if (gfs2_glmutex_trylock(gl)) { | |
12132933 | 1642 | if (list_empty(&gl->gl_holders) && |
50299965 | 1643 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
c4f68a13 | 1644 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa DT |
1645 | gfs2_glmutex_unlock(gl); |
1646 | } | |
1647 | ||
1648 | gfs2_glock_put(gl); | |
1649 | } | |
1650 | ||
1651 | /** | |
1652 | * examine_bucket - Call a function for glock in a hash bucket | |
1653 | * @examiner: the function | |
1654 | * @sdp: the filesystem | |
1655 | * @bucket: the bucket | |
1656 | * | |
1657 | * Returns: 1 if the bucket has entries | |
1658 | */ | |
1659 | ||
1660 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
37b2fa6a | 1661 | unsigned int hash) |
b3b94faa | 1662 | { |
24264434 SW |
1663 | struct gfs2_glock *gl, *prev = NULL; |
1664 | int has_entries = 0; | |
b6397893 | 1665 | struct hlist_head *head = &gl_hash_table[hash].hb_list; |
b3b94faa | 1666 | |
24264434 | 1667 | read_lock(gl_lock_addr(hash)); |
b6397893 SW |
1668 | /* Can't use hlist_for_each_entry - don't want prefetch here */ |
1669 | if (hlist_empty(head)) | |
24264434 | 1670 | goto out; |
b6397893 SW |
1671 | gl = list_entry(head->first, struct gfs2_glock, gl_list); |
1672 | while(1) { | |
8fbbfd21 | 1673 | if (!sdp || gl->gl_sbd == sdp) { |
b3b94faa | 1674 | gfs2_glock_hold(gl); |
24264434 SW |
1675 | read_unlock(gl_lock_addr(hash)); |
1676 | if (prev) | |
1677 | gfs2_glock_put(prev); | |
1678 | prev = gl; | |
1679 | examiner(gl); | |
a8336344 | 1680 | has_entries = 1; |
24264434 | 1681 | read_lock(gl_lock_addr(hash)); |
b3b94faa | 1682 | } |
b6397893 SW |
1683 | if (gl->gl_list.next == NULL) |
1684 | break; | |
24264434 | 1685 | gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); |
b3b94faa | 1686 | } |
24264434 SW |
1687 | out: |
1688 | read_unlock(gl_lock_addr(hash)); | |
1689 | if (prev) | |
1690 | gfs2_glock_put(prev); | |
8fbbfd21 | 1691 | cond_resched(); |
24264434 | 1692 | return has_entries; |
b3b94faa DT |
1693 | } |
1694 | ||
1695 | /** | |
1696 | * scan_glock - look at a glock and see if we can reclaim it | |
1697 | * @gl: the glock to look at | |
1698 | * | |
1699 | */ | |
1700 | ||
1701 | static void scan_glock(struct gfs2_glock *gl) | |
1702 | { | |
b004157a | 1703 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) |
24264434 | 1704 | return; |
a2242db0 | 1705 | |
b3b94faa | 1706 | if (gfs2_glmutex_trylock(gl)) { |
12132933 | 1707 | if (list_empty(&gl->gl_holders) && |
24264434 | 1708 | gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) |
b3b94faa | 1709 | goto out_schedule; |
b3b94faa DT |
1710 | gfs2_glmutex_unlock(gl); |
1711 | } | |
b3b94faa DT |
1712 | return; |
1713 | ||
627add2d | 1714 | out_schedule: |
b3b94faa DT |
1715 | gfs2_glmutex_unlock(gl); |
1716 | gfs2_glock_schedule_for_reclaim(gl); | |
b3b94faa DT |
1717 | } |
1718 | ||
b3b94faa DT |
1719 | /** |
1720 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1721 | * @gl: the glock to look at | |
1722 | * | |
1723 | */ | |
1724 | ||
1725 | static void clear_glock(struct gfs2_glock *gl) | |
1726 | { | |
1727 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1728 | int released; | |
1729 | ||
1730 | spin_lock(&sdp->sd_reclaim_lock); | |
1731 | if (!list_empty(&gl->gl_reclaim)) { | |
1732 | list_del_init(&gl->gl_reclaim); | |
1733 | atomic_dec(&sdp->sd_reclaim_count); | |
190562bd | 1734 | spin_unlock(&sdp->sd_reclaim_lock); |
b3b94faa DT |
1735 | released = gfs2_glock_put(gl); |
1736 | gfs2_assert(sdp, !released); | |
190562bd SW |
1737 | } else { |
1738 | spin_unlock(&sdp->sd_reclaim_lock); | |
b3b94faa | 1739 | } |
b3b94faa DT |
1740 | |
1741 | if (gfs2_glmutex_trylock(gl)) { | |
90101c31 | 1742 | if (list_empty(&gl->gl_holders) && |
b3b94faa | 1743 | gl->gl_state != LM_ST_UNLOCKED) |
c4f68a13 | 1744 | handle_callback(gl, LM_ST_UNLOCKED, 0, 0); |
b3b94faa DT |
1745 | gfs2_glmutex_unlock(gl); |
1746 | } | |
b3b94faa DT |
1747 | } |
1748 | ||
1749 | /** | |
1750 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1751 | * @sdp: the filesystem | |
1752 | * @wait: wait until it's all gone | |
1753 | * | |
1754 | * Called when unmounting the filesystem, or when inter-node lock manager | |
1755 | * requests DROPLOCKS because it is running out of capacity. | |
1756 | */ | |
1757 | ||
1758 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
1759 | { | |
1760 | unsigned long t; | |
1761 | unsigned int x; | |
1762 | int cont; | |
1763 | ||
1764 | t = jiffies; | |
1765 | ||
1766 | for (;;) { | |
1767 | cont = 0; | |
24264434 | 1768 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { |
907b9bce | 1769 | if (examine_bucket(clear_glock, sdp, x)) |
b3b94faa | 1770 | cont = 1; |
24264434 | 1771 | } |
b3b94faa DT |
1772 | |
1773 | if (!wait || !cont) | |
1774 | break; | |
1775 | ||
1776 | if (time_after_eq(jiffies, | |
1777 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
1778 | fs_warn(sdp, "Unmount seems to be stalled. " | |
1779 | "Dumping lock state...\n"); | |
1780 | gfs2_dump_lockstate(sdp); | |
1781 | t = jiffies; | |
1782 | } | |
1783 | ||
61be084e | 1784 | down_write(&gfs2_umount_flush_sem); |
b3b94faa | 1785 | invalidate_inodes(sdp->sd_vfs); |
61be084e | 1786 | up_write(&gfs2_umount_flush_sem); |
fd88de56 | 1787 | msleep(10); |
b3b94faa DT |
1788 | } |
1789 | } | |
1790 | ||
1791 | /* | |
1792 | * Diagnostic routines to help debug distributed deadlock | |
1793 | */ | |
1794 | ||
04b933f2 RP |
1795 | static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt, |
1796 | unsigned long address) | |
1797 | { | |
7a0079d9 | 1798 | char buffer[KSYM_SYMBOL_LEN]; |
04b933f2 | 1799 | |
7a0079d9 RP |
1800 | sprint_symbol(buffer, address); |
1801 | print_dbg(gi, fmt, buffer); | |
04b933f2 RP |
1802 | } |
1803 | ||
b3b94faa DT |
1804 | /** |
1805 | * dump_holder - print information about a glock holder | |
1806 | * @str: a string naming the type of holder | |
1807 | * @gh: the glock holder | |
1808 | * | |
1809 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1810 | */ | |
1811 | ||
7c52b166 RP |
1812 | static int dump_holder(struct glock_iter *gi, char *str, |
1813 | struct gfs2_holder *gh) | |
b3b94faa DT |
1814 | { |
1815 | unsigned int x; | |
04b933f2 | 1816 | struct task_struct *gh_owner; |
b3b94faa | 1817 | |
7c52b166 | 1818 | print_dbg(gi, " %s\n", str); |
04b933f2 RP |
1819 | if (gh->gh_owner_pid) { |
1820 | print_dbg(gi, " owner = %ld ", (long)gh->gh_owner_pid); | |
1821 | gh_owner = find_task_by_pid(gh->gh_owner_pid); | |
1822 | if (gh_owner) | |
1823 | print_dbg(gi, "(%s)\n", gh_owner->comm); | |
1824 | else | |
1825 | print_dbg(gi, "(ended)\n"); | |
1826 | } else | |
1827 | print_dbg(gi, " owner = -1\n"); | |
7c52b166 RP |
1828 | print_dbg(gi, " gh_state = %u\n", gh->gh_state); |
1829 | print_dbg(gi, " gh_flags ="); | |
b3b94faa DT |
1830 | for (x = 0; x < 32; x++) |
1831 | if (gh->gh_flags & (1 << x)) | |
7c52b166 RP |
1832 | print_dbg(gi, " %u", x); |
1833 | print_dbg(gi, " \n"); | |
1834 | print_dbg(gi, " error = %d\n", gh->gh_error); | |
1835 | print_dbg(gi, " gh_iflags ="); | |
b3b94faa DT |
1836 | for (x = 0; x < 32; x++) |
1837 | if (test_bit(x, &gh->gh_iflags)) | |
7c52b166 RP |
1838 | print_dbg(gi, " %u", x); |
1839 | print_dbg(gi, " \n"); | |
04b933f2 | 1840 | gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip); |
b3b94faa | 1841 | |
7c52b166 | 1842 | return 0; |
b3b94faa DT |
1843 | } |
1844 | ||
1845 | /** | |
1846 | * dump_inode - print information about an inode | |
1847 | * @ip: the inode | |
1848 | * | |
1849 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1850 | */ | |
1851 | ||
7c52b166 | 1852 | static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip) |
b3b94faa DT |
1853 | { |
1854 | unsigned int x; | |
b3b94faa | 1855 | |
7c52b166 RP |
1856 | print_dbg(gi, " Inode:\n"); |
1857 | print_dbg(gi, " num = %llu/%llu\n", | |
dbb7cae2 SW |
1858 | (unsigned long long)ip->i_no_formal_ino, |
1859 | (unsigned long long)ip->i_no_addr); | |
7c52b166 RP |
1860 | print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode)); |
1861 | print_dbg(gi, " i_flags ="); | |
b3b94faa DT |
1862 | for (x = 0; x < 32; x++) |
1863 | if (test_bit(x, &ip->i_flags)) | |
7c52b166 RP |
1864 | print_dbg(gi, " %u", x); |
1865 | print_dbg(gi, " \n"); | |
1866 | return 0; | |
b3b94faa DT |
1867 | } |
1868 | ||
1869 | /** | |
1870 | * dump_glock - print information about a glock | |
1871 | * @gl: the glock | |
1872 | * @count: where we are in the buffer | |
1873 | * | |
1874 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1875 | */ | |
1876 | ||
7c52b166 | 1877 | static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl) |
b3b94faa DT |
1878 | { |
1879 | struct gfs2_holder *gh; | |
1880 | unsigned int x; | |
1881 | int error = -ENOBUFS; | |
04b933f2 | 1882 | struct task_struct *gl_owner; |
b3b94faa DT |
1883 | |
1884 | spin_lock(&gl->gl_spin); | |
1885 | ||
a947e033 | 1886 | print_dbg(gi, "Glock 0x%p (%u, 0x%llx)\n", gl, gl->gl_name.ln_type, |
7c52b166 RP |
1887 | (unsigned long long)gl->gl_name.ln_number); |
1888 | print_dbg(gi, " gl_flags ="); | |
85d1da67 | 1889 | for (x = 0; x < 32; x++) { |
b3b94faa | 1890 | if (test_bit(x, &gl->gl_flags)) |
7c52b166 RP |
1891 | print_dbg(gi, " %u", x); |
1892 | } | |
04b933f2 RP |
1893 | if (!test_bit(GLF_LOCK, &gl->gl_flags)) |
1894 | print_dbg(gi, " (unlocked)"); | |
7c52b166 RP |
1895 | print_dbg(gi, " \n"); |
1896 | print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref)); | |
1897 | print_dbg(gi, " gl_state = %u\n", gl->gl_state); | |
04b933f2 RP |
1898 | if (gl->gl_owner_pid) { |
1899 | gl_owner = find_task_by_pid(gl->gl_owner_pid); | |
1900 | if (gl_owner) | |
1901 | print_dbg(gi, " gl_owner = pid %d (%s)\n", | |
1902 | gl->gl_owner_pid, gl_owner->comm); | |
1903 | else | |
1904 | print_dbg(gi, " gl_owner = %d (ended)\n", | |
1905 | gl->gl_owner_pid); | |
1906 | } else | |
1907 | print_dbg(gi, " gl_owner = -1\n"); | |
7c52b166 RP |
1908 | print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip); |
1909 | print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); | |
1910 | print_dbg(gi, " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
1911 | print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
1912 | print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
1913 | print_dbg(gi, " le = %s\n", | |
b3b94faa | 1914 | (list_empty(&gl->gl_le.le_list)) ? "no" : "yes"); |
7c52b166 RP |
1915 | print_dbg(gi, " reclaim = %s\n", |
1916 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); | |
b3b94faa | 1917 | if (gl->gl_aspace) |
7c52b166 RP |
1918 | print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, |
1919 | gl->gl_aspace->i_mapping->nrpages); | |
b3b94faa | 1920 | else |
7c52b166 RP |
1921 | print_dbg(gi, " aspace = no\n"); |
1922 | print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa | 1923 | if (gl->gl_req_gh) { |
7c52b166 | 1924 | error = dump_holder(gi, "Request", gl->gl_req_gh); |
b3b94faa DT |
1925 | if (error) |
1926 | goto out; | |
1927 | } | |
1928 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
7c52b166 | 1929 | error = dump_holder(gi, "Holder", gh); |
b3b94faa DT |
1930 | if (error) |
1931 | goto out; | |
1932 | } | |
1933 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
7c52b166 | 1934 | error = dump_holder(gi, "Waiter1", gh); |
b3b94faa DT |
1935 | if (error) |
1936 | goto out; | |
1937 | } | |
b3b94faa | 1938 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { |
7c52b166 | 1939 | error = dump_holder(gi, "Waiter3", gh); |
b3b94faa DT |
1940 | if (error) |
1941 | goto out; | |
1942 | } | |
3b8249f6 SW |
1943 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { |
1944 | print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n", | |
cd81a4ba RP |
1945 | gl->gl_demote_state, (unsigned long long) |
1946 | (jiffies - gl->gl_demote_time)*(1000000/HZ)); | |
3b8249f6 | 1947 | } |
5c676f6d | 1948 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa | 1949 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
7c52b166 RP |
1950 | list_empty(&gl->gl_holders)) { |
1951 | error = dump_inode(gi, gl->gl_object); | |
b3b94faa DT |
1952 | if (error) |
1953 | goto out; | |
1954 | } else { | |
1955 | error = -ENOBUFS; | |
7c52b166 | 1956 | print_dbg(gi, " Inode: busy\n"); |
b3b94faa DT |
1957 | } |
1958 | } | |
1959 | ||
1960 | error = 0; | |
1961 | ||
a91ea69f | 1962 | out: |
b3b94faa | 1963 | spin_unlock(&gl->gl_spin); |
b3b94faa DT |
1964 | return error; |
1965 | } | |
1966 | ||
1967 | /** | |
1968 | * gfs2_dump_lockstate - print out the current lockstate | |
1969 | * @sdp: the filesystem | |
1970 | * @ub: the buffer to copy the information into | |
1971 | * | |
1972 | * If @ub is NULL, dump the lockstate to the console. | |
1973 | * | |
1974 | */ | |
1975 | ||
08bc2dbc | 1976 | static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) |
b3b94faa | 1977 | { |
b3b94faa | 1978 | struct gfs2_glock *gl; |
b6397893 | 1979 | struct hlist_node *h; |
b3b94faa DT |
1980 | unsigned int x; |
1981 | int error = 0; | |
1982 | ||
1983 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
b3b94faa | 1984 | |
087efdd3 | 1985 | read_lock(gl_lock_addr(x)); |
b3b94faa | 1986 | |
b6397893 | 1987 | hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { |
85d1da67 SW |
1988 | if (gl->gl_sbd != sdp) |
1989 | continue; | |
b3b94faa | 1990 | |
7c52b166 | 1991 | error = dump_glock(NULL, gl); |
b3b94faa DT |
1992 | if (error) |
1993 | break; | |
1994 | } | |
1995 | ||
087efdd3 | 1996 | read_unlock(gl_lock_addr(x)); |
b3b94faa DT |
1997 | |
1998 | if (error) | |
1999 | break; | |
2000 | } | |
2001 | ||
2002 | ||
2003 | return error; | |
2004 | } | |
2005 | ||
8fbbfd21 SW |
2006 | /** |
2007 | * gfs2_scand - Look for cached glocks and inodes to toss from memory | |
2008 | * @sdp: Pointer to GFS2 superblock | |
2009 | * | |
2010 | * One of these daemons runs, finding candidates to add to sd_reclaim_list. | |
2011 | * See gfs2_glockd() | |
2012 | */ | |
2013 | ||
2014 | static int gfs2_scand(void *data) | |
2015 | { | |
2016 | unsigned x; | |
2017 | unsigned delay; | |
2018 | ||
2019 | while (!kthread_should_stop()) { | |
2020 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
2021 | examine_bucket(scan_glock, NULL, x); | |
2022 | if (freezing(current)) | |
2023 | refrigerator(); | |
2024 | delay = scand_secs; | |
2025 | if (delay < 1) | |
2026 | delay = 1; | |
2027 | schedule_timeout_interruptible(delay * HZ); | |
2028 | } | |
2029 | ||
2030 | return 0; | |
2031 | } | |
2032 | ||
2033 | ||
2034 | ||
85d1da67 SW |
2035 | int __init gfs2_glock_init(void) |
2036 | { | |
2037 | unsigned i; | |
2038 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
b6397893 | 2039 | INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); |
85d1da67 | 2040 | } |
087efdd3 SW |
2041 | #ifdef GL_HASH_LOCK_SZ |
2042 | for(i = 0; i < GL_HASH_LOCK_SZ; i++) { | |
2043 | rwlock_init(&gl_hash_locks[i]); | |
2044 | } | |
2045 | #endif | |
8fbbfd21 SW |
2046 | |
2047 | scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand"); | |
2048 | if (IS_ERR(scand_process)) | |
2049 | return PTR_ERR(scand_process); | |
2050 | ||
c4f68a13 BM |
2051 | glock_workqueue = create_workqueue("glock_workqueue"); |
2052 | if (IS_ERR(glock_workqueue)) { | |
2053 | kthread_stop(scand_process); | |
2054 | return PTR_ERR(glock_workqueue); | |
2055 | } | |
2056 | ||
85d1da67 SW |
2057 | return 0; |
2058 | } | |
2059 | ||
8fbbfd21 SW |
2060 | void gfs2_glock_exit(void) |
2061 | { | |
c4f68a13 | 2062 | destroy_workqueue(glock_workqueue); |
8fbbfd21 SW |
2063 | kthread_stop(scand_process); |
2064 | } | |
2065 | ||
2066 | module_param(scand_secs, uint, S_IRUGO|S_IWUSR); | |
2067 | MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs"); | |
2068 | ||
7c52b166 RP |
2069 | static int gfs2_glock_iter_next(struct glock_iter *gi) |
2070 | { | |
7b08fc62 SW |
2071 | struct gfs2_glock *gl; |
2072 | ||
a947e033 | 2073 | restart: |
7a0079d9 | 2074 | read_lock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
2075 | gl = gi->gl; |
2076 | if (gl) { | |
a947e033 AD |
2077 | gi->gl = hlist_entry(gl->gl_list.next, |
2078 | struct gfs2_glock, gl_list); | |
7c52b166 | 2079 | if (gi->gl) |
7b08fc62 | 2080 | gfs2_glock_hold(gi->gl); |
7c52b166 | 2081 | } |
7a0079d9 | 2082 | read_unlock(gl_lock_addr(gi->hash)); |
7b08fc62 SW |
2083 | if (gl) |
2084 | gfs2_glock_put(gl); | |
a947e033 | 2085 | if (gl && gi->gl == NULL) |
7b08fc62 | 2086 | gi->hash++; |
a947e033 | 2087 | while(gi->gl == NULL) { |
7b08fc62 SW |
2088 | if (gi->hash >= GFS2_GL_HASH_SIZE) |
2089 | return 1; | |
2090 | read_lock(gl_lock_addr(gi->hash)); | |
2091 | gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, | |
2092 | struct gfs2_glock, gl_list); | |
2093 | if (gi->gl) | |
2094 | gfs2_glock_hold(gi->gl); | |
2095 | read_unlock(gl_lock_addr(gi->hash)); | |
a947e033 | 2096 | gi->hash++; |
7b08fc62 | 2097 | } |
a947e033 AD |
2098 | |
2099 | if (gi->sdp != gi->gl->gl_sbd) | |
2100 | goto restart; | |
2101 | ||
7c52b166 RP |
2102 | return 0; |
2103 | } | |
2104 | ||
2105 | static void gfs2_glock_iter_free(struct glock_iter *gi) | |
2106 | { | |
7b08fc62 SW |
2107 | if (gi->gl) |
2108 | gfs2_glock_put(gi->gl); | |
7c52b166 RP |
2109 | kfree(gi); |
2110 | } | |
2111 | ||
2112 | static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp) | |
2113 | { | |
2114 | struct glock_iter *gi; | |
2115 | ||
2116 | gi = kmalloc(sizeof (*gi), GFP_KERNEL); | |
2117 | if (!gi) | |
2118 | return NULL; | |
2119 | ||
2120 | gi->sdp = sdp; | |
2121 | gi->hash = 0; | |
7c52b166 | 2122 | gi->seq = NULL; |
a947e033 | 2123 | gi->gl = NULL; |
7c52b166 RP |
2124 | memset(gi->string, 0, sizeof(gi->string)); |
2125 | ||
a947e033 | 2126 | if (gfs2_glock_iter_next(gi)) { |
7c52b166 RP |
2127 | gfs2_glock_iter_free(gi); |
2128 | return NULL; | |
2129 | } | |
2130 | ||
2131 | return gi; | |
2132 | } | |
2133 | ||
2134 | static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos) | |
2135 | { | |
2136 | struct glock_iter *gi; | |
2137 | loff_t n = *pos; | |
2138 | ||
2139 | gi = gfs2_glock_iter_init(file->private); | |
2140 | if (!gi) | |
2141 | return NULL; | |
2142 | ||
7b08fc62 | 2143 | while(n--) { |
7c52b166 RP |
2144 | if (gfs2_glock_iter_next(gi)) { |
2145 | gfs2_glock_iter_free(gi); | |
2146 | return NULL; | |
2147 | } | |
2148 | } | |
2149 | ||
2150 | return gi; | |
2151 | } | |
2152 | ||
2153 | static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr, | |
2154 | loff_t *pos) | |
2155 | { | |
2156 | struct glock_iter *gi = iter_ptr; | |
2157 | ||
2158 | (*pos)++; | |
2159 | ||
2160 | if (gfs2_glock_iter_next(gi)) { | |
2161 | gfs2_glock_iter_free(gi); | |
2162 | return NULL; | |
2163 | } | |
2164 | ||
2165 | return gi; | |
2166 | } | |
2167 | ||
2168 | static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr) | |
2169 | { | |
7b08fc62 SW |
2170 | struct glock_iter *gi = iter_ptr; |
2171 | if (gi) | |
2172 | gfs2_glock_iter_free(gi); | |
7c52b166 RP |
2173 | } |
2174 | ||
2175 | static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr) | |
2176 | { | |
2177 | struct glock_iter *gi = iter_ptr; | |
2178 | ||
2179 | gi->seq = file; | |
2180 | dump_glock(gi, gi->gl); | |
2181 | ||
2182 | return 0; | |
2183 | } | |
2184 | ||
4ef29002 | 2185 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
2186 | .start = gfs2_glock_seq_start, |
2187 | .next = gfs2_glock_seq_next, | |
2188 | .stop = gfs2_glock_seq_stop, | |
2189 | .show = gfs2_glock_seq_show, | |
2190 | }; | |
2191 | ||
2192 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
2193 | { | |
2194 | struct seq_file *seq; | |
2195 | int ret; | |
2196 | ||
2197 | ret = seq_open(file, &gfs2_glock_seq_ops); | |
2198 | if (ret) | |
2199 | return ret; | |
2200 | ||
2201 | seq = file->private_data; | |
2202 | seq->private = inode->i_private; | |
2203 | ||
2204 | return 0; | |
2205 | } | |
2206 | ||
2207 | static const struct file_operations gfs2_debug_fops = { | |
2208 | .owner = THIS_MODULE, | |
2209 | .open = gfs2_debugfs_open, | |
2210 | .read = seq_read, | |
2211 | .llseek = seq_lseek, | |
2212 | .release = seq_release | |
2213 | }; | |
2214 | ||
2215 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
2216 | { | |
5f882096 RP |
2217 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
2218 | if (!sdp->debugfs_dir) | |
2219 | return -ENOMEM; | |
2220 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
2221 | S_IFREG | S_IRUGO, | |
2222 | sdp->debugfs_dir, sdp, | |
2223 | &gfs2_debug_fops); | |
2224 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
2225 | return -ENOMEM; |
2226 | ||
2227 | return 0; | |
2228 | } | |
2229 | ||
2230 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
2231 | { | |
5f882096 RP |
2232 | if (sdp && sdp->debugfs_dir) { |
2233 | if (sdp->debugfs_dentry_glocks) { | |
2234 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
2235 | sdp->debugfs_dentry_glocks = NULL; | |
2236 | } | |
2237 | debugfs_remove(sdp->debugfs_dir); | |
2238 | sdp->debugfs_dir = NULL; | |
2239 | } | |
7c52b166 RP |
2240 | } |
2241 | ||
2242 | int gfs2_register_debugfs(void) | |
2243 | { | |
2244 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
2245 | return gfs2_root ? 0 : -ENOMEM; | |
2246 | } | |
2247 | ||
2248 | void gfs2_unregister_debugfs(void) | |
2249 | { | |
2250 | debugfs_remove(gfs2_root); | |
5f882096 | 2251 | gfs2_root = NULL; |
7c52b166 | 2252 | } |