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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. | |
cf45b752 | 3 | * Copyright (C) 2004-2008 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> | |
b3b94faa DT |
13 | #include <linux/buffer_head.h> |
14 | #include <linux/delay.h> | |
15 | #include <linux/sort.h> | |
16 | #include <linux/jhash.h> | |
d0dc80db | 17 | #include <linux/kallsyms.h> |
5c676f6d | 18 | #include <linux/gfs2_ondisk.h> |
24264434 | 19 | #include <linux/list.h> |
fee852e3 | 20 | #include <linux/wait.h> |
95d97b7d | 21 | #include <linux/module.h> |
b3b94faa | 22 | #include <asm/uaccess.h> |
7c52b166 RP |
23 | #include <linux/seq_file.h> |
24 | #include <linux/debugfs.h> | |
8fbbfd21 SW |
25 | #include <linux/kthread.h> |
26 | #include <linux/freezer.h> | |
c4f68a13 BM |
27 | #include <linux/workqueue.h> |
28 | #include <linux/jiffies.h> | |
bc015cb8 SW |
29 | #include <linux/rcupdate.h> |
30 | #include <linux/rculist_bl.h> | |
31 | #include <linux/bit_spinlock.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" | |
b3b94faa DT |
38 | #include "lops.h" |
39 | #include "meta_io.h" | |
40 | #include "quota.h" | |
41 | #include "super.h" | |
5c676f6d | 42 | #include "util.h" |
813e0c46 | 43 | #include "bmap.h" |
63997775 SW |
44 | #define CREATE_TRACE_POINTS |
45 | #include "trace_gfs2.h" | |
b3b94faa | 46 | |
6802e340 SW |
47 | struct gfs2_glock_iter { |
48 | int hash; /* hash bucket index */ | |
49 | struct gfs2_sbd *sdp; /* incore superblock */ | |
50 | struct gfs2_glock *gl; /* current glock struct */ | |
51 | char string[512]; /* scratch space */ | |
7c52b166 RP |
52 | }; |
53 | ||
b3b94faa DT |
54 | typedef void (*glock_examiner) (struct gfs2_glock * gl); |
55 | ||
6802e340 SW |
56 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); |
57 | #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0) | |
58 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); | |
c4f68a13 | 59 | |
7c52b166 | 60 | static struct dentry *gfs2_root; |
c4f68a13 | 61 | static struct workqueue_struct *glock_workqueue; |
b94a170e | 62 | struct workqueue_struct *gfs2_delete_workqueue; |
97cc1025 SW |
63 | static LIST_HEAD(lru_list); |
64 | static atomic_t lru_count = ATOMIC_INIT(0); | |
eb8374e7 | 65 | static DEFINE_SPINLOCK(lru_lock); |
08bc2dbc | 66 | |
b6397893 | 67 | #define GFS2_GL_HASH_SHIFT 15 |
087efdd3 SW |
68 | #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) |
69 | #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) | |
70 | ||
bc015cb8 | 71 | static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE]; |
04b933f2 | 72 | static struct dentry *gfs2_root; |
087efdd3 | 73 | |
b3b94faa DT |
74 | /** |
75 | * gl_hash() - Turn glock number into hash bucket number | |
76 | * @lock: The glock number | |
77 | * | |
78 | * Returns: The number of the corresponding hash bucket | |
79 | */ | |
80 | ||
b8547856 SW |
81 | static unsigned int gl_hash(const struct gfs2_sbd *sdp, |
82 | const struct lm_lockname *name) | |
b3b94faa DT |
83 | { |
84 | unsigned int h; | |
85 | ||
cd915493 | 86 | h = jhash(&name->ln_number, sizeof(u64), 0); |
b3b94faa | 87 | h = jhash(&name->ln_type, sizeof(unsigned int), h); |
b8547856 | 88 | h = jhash(&sdp, sizeof(struct gfs2_sbd *), h); |
b3b94faa DT |
89 | h &= GFS2_GL_HASH_MASK; |
90 | ||
91 | return h; | |
92 | } | |
93 | ||
bc015cb8 SW |
94 | static inline void spin_lock_bucket(unsigned int hash) |
95 | { | |
96 | struct hlist_bl_head *bl = &gl_hash_table[hash]; | |
97 | bit_spin_lock(0, (unsigned long *)bl); | |
98 | } | |
b3b94faa | 99 | |
bc015cb8 SW |
100 | static inline void spin_unlock_bucket(unsigned int hash) |
101 | { | |
102 | struct hlist_bl_head *bl = &gl_hash_table[hash]; | |
103 | __bit_spin_unlock(0, (unsigned long *)bl); | |
104 | } | |
b3b94faa | 105 | |
fc0e38da | 106 | static void gfs2_glock_dealloc(struct rcu_head *rcu) |
b3b94faa | 107 | { |
bc015cb8 | 108 | struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); |
b3b94faa | 109 | |
bc015cb8 SW |
110 | if (gl->gl_ops->go_flags & GLOF_ASPACE) |
111 | kmem_cache_free(gfs2_glock_aspace_cachep, gl); | |
112 | else | |
113 | kmem_cache_free(gfs2_glock_cachep, gl); | |
fc0e38da SW |
114 | } |
115 | ||
116 | void gfs2_glock_free(struct gfs2_glock *gl) | |
b3b94faa DT |
117 | { |
118 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa | 119 | |
fc0e38da | 120 | call_rcu(&gl->gl_rcu, gfs2_glock_dealloc); |
bc015cb8 SW |
121 | if (atomic_dec_and_test(&sdp->sd_glock_disposal)) |
122 | wake_up(&sdp->sd_glock_wait); | |
b3b94faa DT |
123 | } |
124 | ||
125 | /** | |
126 | * gfs2_glock_hold() - increment reference count on glock | |
127 | * @gl: The glock to hold | |
128 | * | |
129 | */ | |
130 | ||
b94a170e | 131 | void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 132 | { |
d8348de0 | 133 | GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
16feb9fe | 134 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
135 | } |
136 | ||
8ff22a6f BM |
137 | /** |
138 | * demote_ok - Check to see if it's ok to unlock a glock | |
139 | * @gl: the glock | |
140 | * | |
141 | * Returns: 1 if it's ok | |
142 | */ | |
143 | ||
144 | static int demote_ok(const struct gfs2_glock *gl) | |
145 | { | |
146 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
147 | ||
bc015cb8 SW |
148 | /* assert_spin_locked(&gl->gl_spin); */ |
149 | ||
8ff22a6f BM |
150 | if (gl->gl_state == LM_ST_UNLOCKED) |
151 | return 0; | |
bc015cb8 SW |
152 | if (test_bit(GLF_LFLUSH, &gl->gl_flags)) |
153 | return 0; | |
154 | if ((gl->gl_name.ln_type != LM_TYPE_INODE) && | |
155 | !list_empty(&gl->gl_holders)) | |
8ff22a6f BM |
156 | return 0; |
157 | if (glops->go_demote_ok) | |
158 | return glops->go_demote_ok(gl); | |
159 | return 1; | |
160 | } | |
161 | ||
bc015cb8 | 162 | |
97cc1025 | 163 | /** |
bc015cb8 | 164 | * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list |
97cc1025 SW |
165 | * @gl: the glock |
166 | * | |
bc015cb8 SW |
167 | * If the glock is demotable, then we add it (or move it) to the end |
168 | * of the glock LRU list. | |
97cc1025 SW |
169 | */ |
170 | ||
bc015cb8 | 171 | static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) |
97cc1025 | 172 | { |
bc015cb8 SW |
173 | if (demote_ok(gl)) { |
174 | spin_lock(&lru_lock); | |
175 | ||
176 | if (!list_empty(&gl->gl_lru)) | |
177 | list_del_init(&gl->gl_lru); | |
178 | else | |
179 | atomic_inc(&lru_count); | |
180 | ||
97cc1025 | 181 | list_add_tail(&gl->gl_lru, &lru_list); |
bc015cb8 | 182 | spin_unlock(&lru_lock); |
97cc1025 | 183 | } |
bc015cb8 SW |
184 | } |
185 | ||
186 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
187 | { | |
188 | spin_lock(&gl->gl_spin); | |
189 | __gfs2_glock_schedule_for_reclaim(gl); | |
190 | spin_unlock(&gl->gl_spin); | |
97cc1025 SW |
191 | } |
192 | ||
8ff22a6f BM |
193 | /** |
194 | * gfs2_glock_put_nolock() - Decrement reference count on glock | |
195 | * @gl: The glock to put | |
196 | * | |
197 | * This function should only be used if the caller has its own reference | |
198 | * to the glock, in addition to the one it is dropping. | |
199 | */ | |
200 | ||
b94a170e | 201 | void gfs2_glock_put_nolock(struct gfs2_glock *gl) |
8ff22a6f BM |
202 | { |
203 | if (atomic_dec_and_test(&gl->gl_ref)) | |
204 | GLOCK_BUG_ON(gl, 1); | |
8ff22a6f BM |
205 | } |
206 | ||
b3b94faa DT |
207 | /** |
208 | * gfs2_glock_put() - Decrement reference count on glock | |
209 | * @gl: The glock to put | |
210 | * | |
211 | */ | |
212 | ||
bc015cb8 | 213 | void gfs2_glock_put(struct gfs2_glock *gl) |
b3b94faa | 214 | { |
bc015cb8 SW |
215 | struct gfs2_sbd *sdp = gl->gl_sbd; |
216 | struct address_space *mapping = gfs2_glock2aspace(gl); | |
b3b94faa | 217 | |
bc015cb8 SW |
218 | if (atomic_dec_and_test(&gl->gl_ref)) { |
219 | spin_lock_bucket(gl->gl_hash); | |
220 | hlist_bl_del_rcu(&gl->gl_list); | |
221 | spin_unlock_bucket(gl->gl_hash); | |
222 | spin_lock(&lru_lock); | |
97cc1025 SW |
223 | if (!list_empty(&gl->gl_lru)) { |
224 | list_del_init(&gl->gl_lru); | |
225 | atomic_dec(&lru_count); | |
226 | } | |
227 | spin_unlock(&lru_lock); | |
6802e340 | 228 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
bc015cb8 SW |
229 | GLOCK_BUG_ON(gl, mapping && mapping->nrpages); |
230 | trace_gfs2_glock_put(gl); | |
231 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); | |
b3b94faa | 232 | } |
b3b94faa DT |
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; | |
bc015cb8 | 248 | struct hlist_bl_node *h; |
b3b94faa | 249 | |
bc015cb8 | 250 | hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], 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; | |
bc015cb8 SW |
255 | if (atomic_inc_not_zero(&gl->gl_ref)) |
256 | return gl; | |
b3b94faa DT |
257 | } |
258 | ||
259 | return NULL; | |
260 | } | |
261 | ||
6802e340 SW |
262 | /** |
263 | * may_grant - check if its ok to grant a new lock | |
264 | * @gl: The glock | |
265 | * @gh: The lock request which we wish to grant | |
266 | * | |
267 | * Returns: true if its ok to grant the lock | |
268 | */ | |
269 | ||
270 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
271 | { | |
272 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
273 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
274 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
275 | return 0; | |
276 | if (gl->gl_state == gh->gh_state) | |
277 | return 1; | |
278 | if (gh->gh_flags & GL_EXACT) | |
279 | return 0; | |
209806ab SW |
280 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
281 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
282 | return 1; | |
283 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
284 | return 1; | |
285 | } | |
6802e340 SW |
286 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
287 | return 1; | |
288 | return 0; | |
289 | } | |
290 | ||
291 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
292 | { | |
293 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
294 | smp_mb__after_clear_bit(); | |
295 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
296 | } | |
297 | ||
d5341a92 SW |
298 | /** |
299 | * do_error - Something unexpected has happened during a lock request | |
300 | * | |
301 | */ | |
302 | ||
303 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
304 | { | |
305 | struct gfs2_holder *gh, *tmp; | |
306 | ||
307 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
308 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
309 | continue; | |
310 | if (ret & LM_OUT_ERROR) | |
311 | gh->gh_error = -EIO; | |
312 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
313 | gh->gh_error = GLR_TRYFAILED; | |
314 | else | |
315 | continue; | |
316 | list_del_init(&gh->gh_list); | |
317 | trace_gfs2_glock_queue(gh, 0); | |
318 | gfs2_holder_wake(gh); | |
319 | } | |
320 | } | |
321 | ||
6802e340 SW |
322 | /** |
323 | * do_promote - promote as many requests as possible on the current queue | |
324 | * @gl: The glock | |
325 | * | |
813e0c46 SW |
326 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
327 | * if a type specific operation is underway. | |
6802e340 SW |
328 | */ |
329 | ||
330 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
331 | __releases(&gl->gl_spin) |
332 | __acquires(&gl->gl_spin) | |
6802e340 SW |
333 | { |
334 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
335 | struct gfs2_holder *gh, *tmp; | |
336 | int ret; | |
337 | ||
338 | restart: | |
339 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
340 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
341 | continue; | |
342 | if (may_grant(gl, gh)) { | |
343 | if (gh->gh_list.prev == &gl->gl_holders && | |
344 | glops->go_lock) { | |
345 | spin_unlock(&gl->gl_spin); | |
346 | /* FIXME: eliminate this eventually */ | |
347 | ret = glops->go_lock(gh); | |
348 | spin_lock(&gl->gl_spin); | |
349 | if (ret) { | |
813e0c46 SW |
350 | if (ret == 1) |
351 | return 2; | |
6802e340 SW |
352 | gh->gh_error = ret; |
353 | list_del_init(&gh->gh_list); | |
63997775 | 354 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
355 | gfs2_holder_wake(gh); |
356 | goto restart; | |
357 | } | |
358 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 359 | trace_gfs2_promote(gh, 1); |
6802e340 SW |
360 | gfs2_holder_wake(gh); |
361 | goto restart; | |
362 | } | |
363 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 364 | trace_gfs2_promote(gh, 0); |
6802e340 SW |
365 | gfs2_holder_wake(gh); |
366 | continue; | |
367 | } | |
368 | if (gh->gh_list.prev == &gl->gl_holders) | |
369 | return 1; | |
d5341a92 | 370 | do_error(gl, 0); |
6802e340 SW |
371 | break; |
372 | } | |
373 | return 0; | |
374 | } | |
375 | ||
6802e340 SW |
376 | /** |
377 | * find_first_waiter - find the first gh that's waiting for the glock | |
378 | * @gl: the glock | |
379 | */ | |
380 | ||
381 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
382 | { | |
383 | struct gfs2_holder *gh; | |
384 | ||
385 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
386 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
387 | return gh; | |
388 | } | |
389 | return NULL; | |
390 | } | |
391 | ||
392 | /** | |
393 | * state_change - record that the glock is now in a different state | |
394 | * @gl: the glock | |
395 | * @new_state the new state | |
396 | * | |
397 | */ | |
398 | ||
399 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
400 | { | |
401 | int held1, held2; | |
402 | ||
403 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
404 | held2 = (new_state != LM_ST_UNLOCKED); | |
405 | ||
406 | if (held1 != held2) { | |
407 | if (held2) | |
408 | gfs2_glock_hold(gl); | |
409 | else | |
8ff22a6f | 410 | gfs2_glock_put_nolock(gl); |
6802e340 | 411 | } |
7b5e3d5f SW |
412 | if (held1 && held2 && list_empty(&gl->gl_holders)) |
413 | clear_bit(GLF_QUEUED, &gl->gl_flags); | |
6802e340 SW |
414 | |
415 | gl->gl_state = new_state; | |
416 | gl->gl_tchange = jiffies; | |
417 | } | |
418 | ||
419 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
420 | { | |
421 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
422 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
423 | smp_mb__after_clear_bit(); | |
424 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
425 | } | |
426 | ||
427 | /** | |
428 | * finish_xmote - The DLM has replied to one of our lock requests | |
429 | * @gl: The glock | |
430 | * @ret: The status from the DLM | |
431 | * | |
432 | */ | |
433 | ||
434 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
435 | { | |
436 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
437 | struct gfs2_holder *gh; | |
438 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 439 | int rv; |
6802e340 SW |
440 | |
441 | spin_lock(&gl->gl_spin); | |
63997775 | 442 | trace_gfs2_glock_state_change(gl, state); |
6802e340 SW |
443 | state_change(gl, state); |
444 | gh = find_first_waiter(gl); | |
445 | ||
446 | /* Demote to UN request arrived during demote to SH or DF */ | |
447 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
448 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
449 | gl->gl_target = LM_ST_UNLOCKED; | |
450 | ||
451 | /* Check for state != intended state */ | |
452 | if (unlikely(state != gl->gl_target)) { | |
453 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
454 | /* move to back of queue and try next entry */ | |
455 | if (ret & LM_OUT_CANCELED) { | |
456 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
457 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
458 | gh = find_first_waiter(gl); | |
459 | gl->gl_target = gh->gh_state; | |
460 | goto retry; | |
461 | } | |
462 | /* Some error or failed "try lock" - report it */ | |
463 | if ((ret & LM_OUT_ERROR) || | |
464 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
465 | gl->gl_target = gl->gl_state; | |
466 | do_error(gl, ret); | |
467 | goto out; | |
468 | } | |
469 | } | |
470 | switch(state) { | |
471 | /* Unlocked due to conversion deadlock, try again */ | |
472 | case LM_ST_UNLOCKED: | |
473 | retry: | |
474 | do_xmote(gl, gh, gl->gl_target); | |
475 | break; | |
476 | /* Conversion fails, unlock and try again */ | |
477 | case LM_ST_SHARED: | |
478 | case LM_ST_DEFERRED: | |
479 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
480 | break; | |
481 | default: /* Everything else */ | |
482 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
483 | GLOCK_BUG_ON(gl, 1); | |
484 | } | |
485 | spin_unlock(&gl->gl_spin); | |
6802e340 SW |
486 | return; |
487 | } | |
488 | ||
489 | /* Fast path - we got what we asked for */ | |
490 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
491 | gfs2_demote_wake(gl); | |
492 | if (state != LM_ST_UNLOCKED) { | |
493 | if (glops->go_xmote_bh) { | |
6802e340 SW |
494 | spin_unlock(&gl->gl_spin); |
495 | rv = glops->go_xmote_bh(gl, gh); | |
6802e340 SW |
496 | spin_lock(&gl->gl_spin); |
497 | if (rv) { | |
498 | do_error(gl, rv); | |
499 | goto out; | |
500 | } | |
501 | } | |
813e0c46 SW |
502 | rv = do_promote(gl); |
503 | if (rv == 2) | |
504 | goto out_locked; | |
6802e340 SW |
505 | } |
506 | out: | |
507 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 508 | out_locked: |
6802e340 | 509 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
510 | } |
511 | ||
6802e340 SW |
512 | /** |
513 | * do_xmote - Calls the DLM to change the state of a lock | |
514 | * @gl: The lock state | |
515 | * @gh: The holder (only for promotes) | |
516 | * @target: The target lock state | |
517 | * | |
518 | */ | |
519 | ||
520 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
521 | __releases(&gl->gl_spin) |
522 | __acquires(&gl->gl_spin) | |
6802e340 SW |
523 | { |
524 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
525 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
526 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
527 | int ret; | |
528 | ||
529 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
530 | LM_FLAG_PRIORITY); | |
921169ca SW |
531 | GLOCK_BUG_ON(gl, gl->gl_state == target); |
532 | GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target); | |
6802e340 SW |
533 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && |
534 | glops->go_inval) { | |
535 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
536 | do_error(gl, 0); /* Fail queued try locks */ | |
537 | } | |
47a25380 | 538 | gl->gl_req = target; |
6802e340 SW |
539 | spin_unlock(&gl->gl_spin); |
540 | if (glops->go_xmote_th) | |
541 | glops->go_xmote_th(gl); | |
542 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
543 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
544 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
545 | ||
546 | gfs2_glock_hold(gl); | |
547 | if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || | |
548 | gl->gl_state == LM_ST_DEFERRED) && | |
549 | !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
550 | lck_flags |= LM_FLAG_TRY_1CB; | |
6802e340 | 551 | |
921169ca SW |
552 | if (sdp->sd_lockstruct.ls_ops->lm_lock) { |
553 | /* lock_dlm */ | |
554 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags); | |
555 | GLOCK_BUG_ON(gl, ret); | |
556 | } else { /* lock_nolock */ | |
557 | finish_xmote(gl, target); | |
6802e340 SW |
558 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
559 | gfs2_glock_put(gl); | |
6802e340 | 560 | } |
921169ca | 561 | |
6802e340 SW |
562 | spin_lock(&gl->gl_spin); |
563 | } | |
564 | ||
565 | /** | |
566 | * find_first_holder - find the first "holder" gh | |
567 | * @gl: the glock | |
568 | */ | |
569 | ||
570 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
571 | { | |
572 | struct gfs2_holder *gh; | |
573 | ||
574 | if (!list_empty(&gl->gl_holders)) { | |
575 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
576 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
577 | return gh; | |
578 | } | |
579 | return NULL; | |
580 | } | |
581 | ||
582 | /** | |
583 | * run_queue - do all outstanding tasks related to a glock | |
584 | * @gl: The glock in question | |
585 | * @nonblock: True if we must not block in run_queue | |
586 | * | |
587 | */ | |
588 | ||
589 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
590 | __releases(&gl->gl_spin) |
591 | __acquires(&gl->gl_spin) | |
6802e340 SW |
592 | { |
593 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 594 | int ret; |
6802e340 SW |
595 | |
596 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
597 | return; | |
598 | ||
599 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
600 | ||
601 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
602 | gl->gl_demote_state != gl->gl_state) { | |
603 | if (find_first_holder(gl)) | |
d8348de0 | 604 | goto out_unlock; |
6802e340 SW |
605 | if (nonblock) |
606 | goto out_sched; | |
607 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 608 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
609 | gl->gl_target = gl->gl_demote_state; |
610 | } else { | |
611 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
612 | gfs2_demote_wake(gl); | |
813e0c46 SW |
613 | ret = do_promote(gl); |
614 | if (ret == 0) | |
d8348de0 | 615 | goto out_unlock; |
813e0c46 | 616 | if (ret == 2) |
a228df63 | 617 | goto out; |
6802e340 SW |
618 | gh = find_first_waiter(gl); |
619 | gl->gl_target = gh->gh_state; | |
620 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
621 | do_error(gl, 0); /* Fail queued try locks */ | |
622 | } | |
623 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 624 | out: |
6802e340 SW |
625 | return; |
626 | ||
627 | out_sched: | |
7e71c55e SW |
628 | clear_bit(GLF_LOCK, &gl->gl_flags); |
629 | smp_mb__after_clear_bit(); | |
6802e340 SW |
630 | gfs2_glock_hold(gl); |
631 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
8ff22a6f | 632 | gfs2_glock_put_nolock(gl); |
7e71c55e SW |
633 | return; |
634 | ||
d8348de0 | 635 | out_unlock: |
6802e340 | 636 | clear_bit(GLF_LOCK, &gl->gl_flags); |
7e71c55e SW |
637 | smp_mb__after_clear_bit(); |
638 | return; | |
6802e340 SW |
639 | } |
640 | ||
b94a170e BM |
641 | static void delete_work_func(struct work_struct *work) |
642 | { | |
643 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); | |
644 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
044b9414 | 645 | struct gfs2_inode *ip; |
b94a170e | 646 | struct inode *inode; |
044b9414 SW |
647 | u64 no_addr = gl->gl_name.ln_number; |
648 | ||
649 | ip = gl->gl_object; | |
650 | /* Note: Unsafe to dereference ip as we don't hold right refs/locks */ | |
b94a170e | 651 | |
b94a170e | 652 | if (ip) |
b94a170e | 653 | inode = gfs2_ilookup(sdp->sd_vfs, no_addr); |
044b9414 SW |
654 | else |
655 | inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED); | |
656 | if (inode && !IS_ERR(inode)) { | |
657 | d_prune_aliases(inode); | |
658 | iput(inode); | |
b94a170e BM |
659 | } |
660 | gfs2_glock_put(gl); | |
661 | } | |
662 | ||
c4f68a13 BM |
663 | static void glock_work_func(struct work_struct *work) |
664 | { | |
6802e340 | 665 | unsigned long delay = 0; |
c4f68a13 | 666 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
26bb7505 | 667 | int drop_ref = 0; |
c4f68a13 | 668 | |
26bb7505 | 669 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
6802e340 | 670 | finish_xmote(gl, gl->gl_reply); |
26bb7505 SW |
671 | drop_ref = 1; |
672 | } | |
c4f68a13 | 673 | spin_lock(&gl->gl_spin); |
265d529c SW |
674 | if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
675 | gl->gl_state != LM_ST_UNLOCKED && | |
676 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 SW |
677 | unsigned long holdtime, now = jiffies; |
678 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; | |
679 | if (time_before(now, holdtime)) | |
680 | delay = holdtime - now; | |
681 | set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); | |
682 | } | |
683 | run_queue(gl, 0); | |
c4f68a13 | 684 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
685 | if (!delay || |
686 | queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
687 | gfs2_glock_put(gl); | |
26bb7505 SW |
688 | if (drop_ref) |
689 | gfs2_glock_put(gl); | |
c4f68a13 BM |
690 | } |
691 | ||
b3b94faa DT |
692 | /** |
693 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
694 | * @sdp: The GFS2 superblock | |
695 | * @number: the lock number | |
696 | * @glops: The glock_operations to use | |
697 | * @create: If 0, don't create the glock if it doesn't exist | |
698 | * @glp: the glock is returned here | |
699 | * | |
700 | * This does not lock a glock, just finds/creates structures for one. | |
701 | * | |
702 | * Returns: errno | |
703 | */ | |
704 | ||
cd915493 | 705 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 706 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
707 | struct gfs2_glock **glp) |
708 | { | |
009d8518 | 709 | struct super_block *s = sdp->sd_vfs; |
37b2fa6a | 710 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 711 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 712 | unsigned int hash = gl_hash(sdp, &name); |
009d8518 | 713 | struct address_space *mapping; |
bc015cb8 | 714 | struct kmem_cache *cachep; |
b3b94faa | 715 | |
bc015cb8 | 716 | rcu_read_lock(); |
37b2fa6a | 717 | gl = search_bucket(hash, sdp, &name); |
bc015cb8 | 718 | rcu_read_unlock(); |
b3b94faa | 719 | |
64d576ba SW |
720 | *glp = gl; |
721 | if (gl) | |
b3b94faa | 722 | return 0; |
64d576ba SW |
723 | if (!create) |
724 | return -ENOENT; | |
b3b94faa | 725 | |
009d8518 | 726 | if (glops->go_flags & GLOF_ASPACE) |
bc015cb8 | 727 | cachep = gfs2_glock_aspace_cachep; |
009d8518 | 728 | else |
bc015cb8 SW |
729 | cachep = gfs2_glock_cachep; |
730 | gl = kmem_cache_alloc(cachep, GFP_KERNEL); | |
b3b94faa DT |
731 | if (!gl) |
732 | return -ENOMEM; | |
733 | ||
8f05228e | 734 | atomic_inc(&sdp->sd_glock_disposal); |
ec45d9f5 | 735 | gl->gl_flags = 0; |
b3b94faa | 736 | gl->gl_name = name; |
16feb9fe | 737 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 738 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 739 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 740 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 741 | gl->gl_hash = hash; |
b3b94faa | 742 | gl->gl_ops = glops; |
f057f6cd SW |
743 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
744 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
745 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 746 | gl->gl_tchange = jiffies; |
ec45d9f5 | 747 | gl->gl_object = NULL; |
b3b94faa | 748 | gl->gl_sbd = sdp; |
c4f68a13 | 749 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b94a170e | 750 | INIT_WORK(&gl->gl_delete, delete_work_func); |
b3b94faa | 751 | |
009d8518 SW |
752 | mapping = gfs2_glock2aspace(gl); |
753 | if (mapping) { | |
754 | mapping->a_ops = &gfs2_meta_aops; | |
755 | mapping->host = s->s_bdev->bd_inode; | |
756 | mapping->flags = 0; | |
757 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
758 | mapping->assoc_mapping = NULL; | |
759 | mapping->backing_dev_info = s->s_bdi; | |
760 | mapping->writeback_index = 0; | |
b3b94faa DT |
761 | } |
762 | ||
bc015cb8 | 763 | spin_lock_bucket(hash); |
37b2fa6a | 764 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 765 | if (tmp) { |
bc015cb8 SW |
766 | spin_unlock_bucket(hash); |
767 | kmem_cache_free(cachep, gl); | |
fc0e38da | 768 | atomic_dec(&sdp->sd_glock_disposal); |
b3b94faa DT |
769 | gl = tmp; |
770 | } else { | |
bc015cb8 SW |
771 | hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]); |
772 | spin_unlock_bucket(hash); | |
b3b94faa DT |
773 | } |
774 | ||
775 | *glp = gl; | |
776 | ||
777 | return 0; | |
b3b94faa DT |
778 | } |
779 | ||
780 | /** | |
781 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
782 | * @gl: the glock | |
783 | * @state: the state we're requesting | |
784 | * @flags: the modifier flags | |
785 | * @gh: the holder structure | |
786 | * | |
787 | */ | |
788 | ||
190562bd | 789 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
790 | struct gfs2_holder *gh) |
791 | { | |
792 | INIT_LIST_HEAD(&gh->gh_list); | |
793 | gh->gh_gl = gl; | |
d0dc80db | 794 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 795 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
796 | gh->gh_state = state; |
797 | gh->gh_flags = flags; | |
798 | gh->gh_error = 0; | |
799 | gh->gh_iflags = 0; | |
b3b94faa DT |
800 | gfs2_glock_hold(gl); |
801 | } | |
802 | ||
803 | /** | |
804 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
805 | * @state: the state we're requesting | |
806 | * @flags: the modifier flags | |
807 | * @gh: the holder structure | |
808 | * | |
809 | * Don't mess with the glock. | |
810 | * | |
811 | */ | |
812 | ||
190562bd | 813 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
814 | { |
815 | gh->gh_state = state; | |
579b78a4 | 816 | gh->gh_flags = flags; |
3b8249f6 | 817 | gh->gh_iflags = 0; |
d0dc80db | 818 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
1a0eae88 BP |
819 | if (gh->gh_owner_pid) |
820 | put_pid(gh->gh_owner_pid); | |
821 | gh->gh_owner_pid = get_pid(task_pid(current)); | |
b3b94faa DT |
822 | } |
823 | ||
824 | /** | |
825 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
826 | * @gh: the holder structure | |
827 | * | |
828 | */ | |
829 | ||
830 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
831 | { | |
b1e058da | 832 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
833 | gfs2_glock_put(gh->gh_gl); |
834 | gh->gh_gl = NULL; | |
d0dc80db | 835 | gh->gh_ip = 0; |
b3b94faa DT |
836 | } |
837 | ||
fe64d517 SW |
838 | /** |
839 | * gfs2_glock_holder_wait | |
840 | * @word: unused | |
841 | * | |
842 | * This function and gfs2_glock_demote_wait both show up in the WCHAN | |
843 | * field. Thus I've separated these otherwise identical functions in | |
844 | * order to be more informative to the user. | |
845 | */ | |
846 | ||
847 | static int gfs2_glock_holder_wait(void *word) | |
fee852e3 SW |
848 | { |
849 | schedule(); | |
850 | return 0; | |
851 | } | |
852 | ||
fe64d517 SW |
853 | static int gfs2_glock_demote_wait(void *word) |
854 | { | |
855 | schedule(); | |
856 | return 0; | |
857 | } | |
858 | ||
6802e340 | 859 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 860 | { |
6802e340 | 861 | might_sleep(); |
fe64d517 | 862 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
da755fdb SW |
863 | } |
864 | ||
6802e340 | 865 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 866 | { |
6802e340 | 867 | might_sleep(); |
fe64d517 | 868 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
b3b94faa DT |
869 | } |
870 | ||
871 | /** | |
6802e340 SW |
872 | * handle_callback - process a demote request |
873 | * @gl: the glock | |
874 | * @state: the state the caller wants us to change to | |
b3b94faa | 875 | * |
6802e340 SW |
876 | * There are only two requests that we are going to see in actual |
877 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
878 | */ |
879 | ||
6802e340 | 880 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 881 | unsigned long delay) |
b3b94faa | 882 | { |
6802e340 | 883 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 884 | |
6802e340 SW |
885 | set_bit(bit, &gl->gl_flags); |
886 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
887 | gl->gl_demote_state = state; | |
888 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
889 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
890 | gl->gl_demote_state != state) { | |
891 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 892 | } |
b94a170e BM |
893 | if (gl->gl_ops->go_callback) |
894 | gl->gl_ops->go_callback(gl); | |
63997775 | 895 | trace_gfs2_demote_rq(gl); |
b3b94faa DT |
896 | } |
897 | ||
898 | /** | |
6802e340 | 899 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
900 | * @gh: the glock holder |
901 | * | |
902 | * Returns: 0 on success | |
903 | */ | |
904 | ||
6802e340 | 905 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 906 | { |
fee852e3 | 907 | wait_on_holder(gh); |
b3b94faa DT |
908 | return gh->gh_error; |
909 | } | |
910 | ||
6802e340 | 911 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 | 912 | { |
5e69069c | 913 | struct va_format vaf; |
7c52b166 RP |
914 | va_list args; |
915 | ||
916 | va_start(args, fmt); | |
5e69069c | 917 | |
6802e340 SW |
918 | if (seq) { |
919 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 920 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
921 | seq_printf(seq, gi->string); |
922 | } else { | |
5e69069c JP |
923 | vaf.fmt = fmt; |
924 | vaf.va = &args; | |
925 | ||
926 | printk(KERN_ERR " %pV", &vaf); | |
6802e340 | 927 | } |
5e69069c | 928 | |
7c52b166 RP |
929 | va_end(args); |
930 | } | |
931 | ||
b3b94faa DT |
932 | /** |
933 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
934 | * @gh: the holder structure to add | |
935 | * | |
6802e340 SW |
936 | * Eventually we should move the recursive locking trap to a |
937 | * debugging option or something like that. This is the fast | |
938 | * path and needs to have the minimum number of distractions. | |
939 | * | |
b3b94faa DT |
940 | */ |
941 | ||
6802e340 | 942 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
943 | __releases(&gl->gl_spin) |
944 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
945 | { |
946 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
947 | struct gfs2_sbd *sdp = gl->gl_sbd; |
948 | struct list_head *insert_pt = NULL; | |
949 | struct gfs2_holder *gh2; | |
950 | int try_lock = 0; | |
b3b94faa | 951 | |
b1e058da | 952 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
953 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
954 | BUG(); | |
190562bd | 955 | |
6802e340 SW |
956 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
957 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
958 | try_lock = 1; | |
959 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
960 | goto fail; | |
961 | } | |
962 | ||
963 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
964 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
965 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
966 | goto trap_recursive; | |
967 | if (try_lock && | |
968 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
969 | !may_grant(gl, gh)) { | |
970 | fail: | |
971 | gh->gh_error = GLR_TRYFAILED; | |
972 | gfs2_holder_wake(gh); | |
973 | return; | |
b4c20166 | 974 | } |
6802e340 SW |
975 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
976 | continue; | |
977 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
978 | insert_pt = &gh2->gh_list; | |
979 | } | |
7b5e3d5f | 980 | set_bit(GLF_QUEUED, &gl->gl_flags); |
edae38a6 | 981 | trace_gfs2_glock_queue(gh, 1); |
6802e340 SW |
982 | if (likely(insert_pt == NULL)) { |
983 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
984 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
985 | goto do_cancel; | |
986 | return; | |
987 | } | |
988 | list_add_tail(&gh->gh_list, insert_pt); | |
989 | do_cancel: | |
990 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
991 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
992 | spin_unlock(&gl->gl_spin); | |
048bca22 | 993 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 994 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 995 | spin_lock(&gl->gl_spin); |
b3b94faa | 996 | } |
6802e340 | 997 | return; |
b3b94faa | 998 | |
6802e340 SW |
999 | trap_recursive: |
1000 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
1001 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
1002 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1003 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
1004 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
1005 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
1006 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1007 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
1008 | __dump_glock(NULL, gl); | |
1009 | BUG(); | |
b3b94faa DT |
1010 | } |
1011 | ||
1012 | /** | |
1013 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1014 | * @gh: the holder structure | |
1015 | * | |
1016 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1017 | * | |
1018 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1019 | */ | |
1020 | ||
1021 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1022 | { | |
1023 | struct gfs2_glock *gl = gh->gh_gl; | |
1024 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1025 | int error = 0; | |
1026 | ||
6802e340 | 1027 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 1028 | return -EIO; |
b3b94faa | 1029 | |
b3b94faa DT |
1030 | spin_lock(&gl->gl_spin); |
1031 | add_to_queue(gh); | |
0809f6ec SW |
1032 | if ((LM_FLAG_NOEXP & gh->gh_flags) && |
1033 | test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1034 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); | |
6802e340 | 1035 | run_queue(gl, 1); |
b3b94faa DT |
1036 | spin_unlock(&gl->gl_spin); |
1037 | ||
6802e340 SW |
1038 | if (!(gh->gh_flags & GL_ASYNC)) |
1039 | error = gfs2_glock_wait(gh); | |
b3b94faa | 1040 | |
b3b94faa DT |
1041 | return error; |
1042 | } | |
1043 | ||
1044 | /** | |
1045 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1046 | * @gh: the holder | |
1047 | * | |
1048 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1049 | */ | |
1050 | ||
1051 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1052 | { | |
6802e340 | 1053 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1054 | } |
1055 | ||
1056 | /** | |
1057 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1058 | * @gh: the glock holder | |
1059 | * | |
1060 | */ | |
1061 | ||
1062 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1063 | { | |
1064 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1065 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1066 | unsigned delay = 0; |
6802e340 | 1067 | int fast_path = 0; |
b3b94faa | 1068 | |
6802e340 | 1069 | spin_lock(&gl->gl_spin); |
b3b94faa | 1070 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1071 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1072 | |
b3b94faa | 1073 | list_del_init(&gh->gh_list); |
6802e340 | 1074 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1075 | if (glops->go_unlock) { |
6802e340 | 1076 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1077 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1078 | glops->go_unlock(gh); |
3042a2cc | 1079 | spin_lock(&gl->gl_spin); |
6802e340 | 1080 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1081 | } |
6802e340 SW |
1082 | if (list_empty(&gl->gl_holders) && |
1083 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1084 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1085 | fast_path = 1; | |
b3b94faa | 1086 | } |
bc015cb8 | 1087 | __gfs2_glock_schedule_for_reclaim(gl); |
63997775 | 1088 | trace_gfs2_glock_queue(gh, 0); |
b3b94faa | 1089 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1090 | if (likely(fast_path)) |
1091 | return; | |
c4f68a13 BM |
1092 | |
1093 | gfs2_glock_hold(gl); | |
1094 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1095 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1096 | delay = gl->gl_ops->go_min_hold_time; | |
1097 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
1098 | gfs2_glock_put(gl); | |
b3b94faa DT |
1099 | } |
1100 | ||
d93cfa98 AD |
1101 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1102 | { | |
1103 | struct gfs2_glock *gl = gh->gh_gl; | |
1104 | gfs2_glock_dq(gh); | |
1105 | wait_on_demote(gl); | |
1106 | } | |
1107 | ||
b3b94faa DT |
1108 | /** |
1109 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1110 | * @gh: the holder structure | |
1111 | * | |
1112 | */ | |
1113 | ||
1114 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1115 | { | |
1116 | gfs2_glock_dq(gh); | |
1117 | gfs2_holder_uninit(gh); | |
1118 | } | |
1119 | ||
1120 | /** | |
1121 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1122 | * @sdp: the filesystem | |
1123 | * @number: the lock number | |
1124 | * @glops: the glock operations for the type of glock | |
1125 | * @state: the state to acquire the glock in | |
1126 | * @flags: modifier flags for the aquisition | |
1127 | * @gh: the struct gfs2_holder | |
1128 | * | |
1129 | * Returns: errno | |
1130 | */ | |
1131 | ||
cd915493 | 1132 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1133 | const struct gfs2_glock_operations *glops, |
1134 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1135 | { |
1136 | struct gfs2_glock *gl; | |
1137 | int error; | |
1138 | ||
1139 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1140 | if (!error) { | |
1141 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1142 | gfs2_glock_put(gl); | |
1143 | } | |
1144 | ||
1145 | return error; | |
1146 | } | |
1147 | ||
1148 | /** | |
1149 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1150 | * @arg_a: the first structure | |
1151 | * @arg_b: the second structure | |
1152 | * | |
1153 | */ | |
1154 | ||
1155 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1156 | { | |
a5e08a9e SW |
1157 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1158 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1159 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1160 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1161 | |
1162 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1163 | return 1; |
1164 | if (a->ln_number < b->ln_number) | |
1165 | return -1; | |
1c0f4872 | 1166 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1167 | return 0; |
b3b94faa DT |
1168 | } |
1169 | ||
1170 | /** | |
1171 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1172 | * @num_gh: the number of structures | |
1173 | * @ghs: an array of struct gfs2_holder structures | |
1174 | * | |
1175 | * Returns: 0 on success (all glocks acquired), | |
1176 | * errno on failure (no glocks acquired) | |
1177 | */ | |
1178 | ||
1179 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1180 | struct gfs2_holder **p) | |
1181 | { | |
1182 | unsigned int x; | |
1183 | int error = 0; | |
1184 | ||
1185 | for (x = 0; x < num_gh; x++) | |
1186 | p[x] = &ghs[x]; | |
1187 | ||
1188 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1189 | ||
1190 | for (x = 0; x < num_gh; x++) { | |
1191 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1192 | ||
1193 | error = gfs2_glock_nq(p[x]); | |
1194 | if (error) { | |
1195 | while (x--) | |
1196 | gfs2_glock_dq(p[x]); | |
1197 | break; | |
1198 | } | |
1199 | } | |
1200 | ||
1201 | return error; | |
1202 | } | |
1203 | ||
1204 | /** | |
1205 | * gfs2_glock_nq_m - acquire multiple glocks | |
1206 | * @num_gh: the number of structures | |
1207 | * @ghs: an array of struct gfs2_holder structures | |
1208 | * | |
b3b94faa DT |
1209 | * |
1210 | * Returns: 0 on success (all glocks acquired), | |
1211 | * errno on failure (no glocks acquired) | |
1212 | */ | |
1213 | ||
1214 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1215 | { | |
eaf5bd3c SW |
1216 | struct gfs2_holder *tmp[4]; |
1217 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1218 | int error = 0; |
1219 | ||
eaf5bd3c SW |
1220 | switch(num_gh) { |
1221 | case 0: | |
b3b94faa | 1222 | return 0; |
eaf5bd3c | 1223 | case 1: |
b3b94faa DT |
1224 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1225 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1226 | default: |
1227 | if (num_gh <= 4) | |
b3b94faa | 1228 | break; |
eaf5bd3c SW |
1229 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1230 | if (!pph) | |
1231 | return -ENOMEM; | |
b3b94faa DT |
1232 | } |
1233 | ||
eaf5bd3c | 1234 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1235 | |
eaf5bd3c SW |
1236 | if (pph != tmp) |
1237 | kfree(pph); | |
b3b94faa DT |
1238 | |
1239 | return error; | |
1240 | } | |
1241 | ||
1242 | /** | |
1243 | * gfs2_glock_dq_m - release multiple glocks | |
1244 | * @num_gh: the number of structures | |
1245 | * @ghs: an array of struct gfs2_holder structures | |
1246 | * | |
1247 | */ | |
1248 | ||
1249 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1250 | { | |
fa1bbdea BP |
1251 | while (num_gh--) |
1252 | gfs2_glock_dq(&ghs[num_gh]); | |
b3b94faa DT |
1253 | } |
1254 | ||
1255 | /** | |
1256 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1257 | * @num_gh: the number of structures | |
1258 | * @ghs: an array of struct gfs2_holder structures | |
1259 | * | |
1260 | */ | |
1261 | ||
1262 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1263 | { | |
fa1bbdea BP |
1264 | while (num_gh--) |
1265 | gfs2_glock_dq_uninit(&ghs[num_gh]); | |
b3b94faa DT |
1266 | } |
1267 | ||
f057f6cd | 1268 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1269 | { |
c4f68a13 BM |
1270 | unsigned long delay = 0; |
1271 | unsigned long holdtime; | |
1272 | unsigned long now = jiffies; | |
b3b94faa | 1273 | |
f057f6cd | 1274 | gfs2_glock_hold(gl); |
c4f68a13 | 1275 | holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; |
7b5e3d5f SW |
1276 | if (test_bit(GLF_QUEUED, &gl->gl_flags)) { |
1277 | if (time_before(now, holdtime)) | |
1278 | delay = holdtime - now; | |
1279 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) | |
1280 | delay = gl->gl_ops->go_min_hold_time; | |
1281 | } | |
b3b94faa | 1282 | |
6802e340 | 1283 | spin_lock(&gl->gl_spin); |
97cc1025 | 1284 | handle_callback(gl, state, delay); |
6802e340 | 1285 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1286 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1287 | gfs2_glock_put(gl); | |
b3b94faa DT |
1288 | } |
1289 | ||
0809f6ec SW |
1290 | /** |
1291 | * gfs2_should_freeze - Figure out if glock should be frozen | |
1292 | * @gl: The glock in question | |
1293 | * | |
1294 | * Glocks are not frozen if (a) the result of the dlm operation is | |
1295 | * an error, (b) the locking operation was an unlock operation or | |
1296 | * (c) if there is a "noexp" flagged request anywhere in the queue | |
1297 | * | |
1298 | * Returns: 1 if freezing should occur, 0 otherwise | |
1299 | */ | |
1300 | ||
1301 | static int gfs2_should_freeze(const struct gfs2_glock *gl) | |
1302 | { | |
1303 | const struct gfs2_holder *gh; | |
1304 | ||
1305 | if (gl->gl_reply & ~LM_OUT_ST_MASK) | |
1306 | return 0; | |
1307 | if (gl->gl_target == LM_ST_UNLOCKED) | |
1308 | return 0; | |
1309 | ||
1310 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
1311 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1312 | continue; | |
1313 | if (LM_FLAG_NOEXP & gh->gh_flags) | |
1314 | return 0; | |
1315 | } | |
1316 | ||
1317 | return 1; | |
1318 | } | |
1319 | ||
b3b94faa | 1320 | /** |
f057f6cd SW |
1321 | * gfs2_glock_complete - Callback used by locking |
1322 | * @gl: Pointer to the glock | |
1323 | * @ret: The return value from the dlm | |
b3b94faa | 1324 | * |
47a25380 SW |
1325 | * The gl_reply field is under the gl_spin lock so that it is ok |
1326 | * to use a bitfield shared with other glock state fields. | |
b3b94faa DT |
1327 | */ |
1328 | ||
f057f6cd | 1329 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1330 | { |
f057f6cd | 1331 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
0809f6ec | 1332 | |
47a25380 | 1333 | spin_lock(&gl->gl_spin); |
f057f6cd | 1334 | gl->gl_reply = ret; |
0809f6ec | 1335 | |
f057f6cd | 1336 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) { |
0809f6ec | 1337 | if (gfs2_should_freeze(gl)) { |
f057f6cd | 1338 | set_bit(GLF_FROZEN, &gl->gl_flags); |
0809f6ec | 1339 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1340 | return; |
0809f6ec | 1341 | } |
b3b94faa | 1342 | } |
47a25380 SW |
1343 | |
1344 | spin_unlock(&gl->gl_spin); | |
f057f6cd | 1345 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
47a25380 | 1346 | smp_wmb(); |
f057f6cd SW |
1347 | gfs2_glock_hold(gl); |
1348 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1349 | gfs2_glock_put(gl); | |
b3b94faa DT |
1350 | } |
1351 | ||
b3b94faa | 1352 | |
7f8275d0 | 1353 | static int gfs2_shrink_glock_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) |
b3b94faa DT |
1354 | { |
1355 | struct gfs2_glock *gl; | |
97cc1025 SW |
1356 | int may_demote; |
1357 | int nr_skipped = 0; | |
97cc1025 | 1358 | LIST_HEAD(skipped); |
b3b94faa | 1359 | |
97cc1025 SW |
1360 | if (nr == 0) |
1361 | goto out; | |
b3b94faa | 1362 | |
97cc1025 SW |
1363 | if (!(gfp_mask & __GFP_FS)) |
1364 | return -1; | |
b3b94faa | 1365 | |
97cc1025 SW |
1366 | spin_lock(&lru_lock); |
1367 | while(nr && !list_empty(&lru_list)) { | |
1368 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1369 | list_del_init(&gl->gl_lru); | |
1370 | atomic_dec(&lru_count); | |
1371 | ||
1372 | /* Test for being demotable */ | |
1373 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1374 | gfs2_glock_hold(gl); | |
97cc1025 SW |
1375 | spin_unlock(&lru_lock); |
1376 | spin_lock(&gl->gl_spin); | |
1377 | may_demote = demote_ok(gl); | |
97cc1025 SW |
1378 | if (may_demote) { |
1379 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1380 | nr--; | |
97cc1025 | 1381 | } |
7e71c55e SW |
1382 | clear_bit(GLF_LOCK, &gl->gl_flags); |
1383 | smp_mb__after_clear_bit(); | |
2163b1e6 | 1384 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
b94a170e BM |
1385 | gfs2_glock_put_nolock(gl); |
1386 | spin_unlock(&gl->gl_spin); | |
97cc1025 | 1387 | spin_lock(&lru_lock); |
2163b1e6 | 1388 | continue; |
97cc1025 | 1389 | } |
2163b1e6 SW |
1390 | nr_skipped++; |
1391 | list_add(&gl->gl_lru, &skipped); | |
b3b94faa | 1392 | } |
97cc1025 SW |
1393 | list_splice(&skipped, &lru_list); |
1394 | atomic_add(nr_skipped, &lru_count); | |
1395 | spin_unlock(&lru_lock); | |
1396 | out: | |
1397 | return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure; | |
b3b94faa DT |
1398 | } |
1399 | ||
97cc1025 SW |
1400 | static struct shrinker glock_shrinker = { |
1401 | .shrink = gfs2_shrink_glock_memory, | |
1402 | .seeks = DEFAULT_SEEKS, | |
1403 | }; | |
1404 | ||
b3b94faa DT |
1405 | /** |
1406 | * examine_bucket - Call a function for glock in a hash bucket | |
1407 | * @examiner: the function | |
1408 | * @sdp: the filesystem | |
1409 | * @bucket: the bucket | |
1410 | * | |
b3b94faa DT |
1411 | */ |
1412 | ||
bc015cb8 | 1413 | static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp, |
37b2fa6a | 1414 | unsigned int hash) |
b3b94faa | 1415 | { |
bc015cb8 SW |
1416 | struct gfs2_glock *gl; |
1417 | struct hlist_bl_head *head = &gl_hash_table[hash]; | |
1418 | struct hlist_bl_node *pos; | |
b3b94faa | 1419 | |
bc015cb8 SW |
1420 | rcu_read_lock(); |
1421 | hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) { | |
1422 | if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref)) | |
24264434 | 1423 | examiner(gl); |
b3b94faa | 1424 | } |
bc015cb8 | 1425 | rcu_read_unlock(); |
8fbbfd21 | 1426 | cond_resched(); |
bc015cb8 SW |
1427 | } |
1428 | ||
1429 | static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) | |
1430 | { | |
1431 | unsigned x; | |
1432 | ||
1433 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1434 | examine_bucket(examiner, sdp, x); | |
b3b94faa DT |
1435 | } |
1436 | ||
f057f6cd SW |
1437 | |
1438 | /** | |
1439 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1440 | * @gl: The glock to thaw | |
1441 | * | |
1442 | * N.B. When we freeze a glock, we leave a ref to the glock outstanding, | |
1443 | * so this has to result in the ref count being dropped by one. | |
1444 | */ | |
1445 | ||
1446 | static void thaw_glock(struct gfs2_glock *gl) | |
1447 | { | |
1448 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1449 | return; | |
f057f6cd SW |
1450 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1451 | gfs2_glock_hold(gl); | |
1452 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1453 | gfs2_glock_put(gl); | |
f057f6cd SW |
1454 | } |
1455 | ||
b3b94faa DT |
1456 | /** |
1457 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1458 | * @gl: the glock to look at | |
1459 | * | |
1460 | */ | |
1461 | ||
1462 | static void clear_glock(struct gfs2_glock *gl) | |
1463 | { | |
97cc1025 SW |
1464 | spin_lock(&lru_lock); |
1465 | if (!list_empty(&gl->gl_lru)) { | |
1466 | list_del_init(&gl->gl_lru); | |
1467 | atomic_dec(&lru_count); | |
b3b94faa | 1468 | } |
97cc1025 | 1469 | spin_unlock(&lru_lock); |
b3b94faa | 1470 | |
6802e340 | 1471 | spin_lock(&gl->gl_spin); |
c741c455 | 1472 | if (gl->gl_state != LM_ST_UNLOCKED) |
97cc1025 | 1473 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
6802e340 SW |
1474 | spin_unlock(&gl->gl_spin); |
1475 | gfs2_glock_hold(gl); | |
1476 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1477 | gfs2_glock_put(gl); | |
b3b94faa DT |
1478 | } |
1479 | ||
f057f6cd SW |
1480 | /** |
1481 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1482 | * @sdp: The super block | |
1483 | * | |
1484 | */ | |
1485 | ||
1486 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1487 | { | |
bc015cb8 SW |
1488 | glock_hash_walk(thaw_glock, sdp); |
1489 | } | |
f057f6cd | 1490 | |
bc015cb8 SW |
1491 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1492 | { | |
1493 | int ret; | |
1494 | spin_lock(&gl->gl_spin); | |
1495 | ret = __dump_glock(seq, gl); | |
1496 | spin_unlock(&gl->gl_spin); | |
1497 | return ret; | |
1498 | } | |
1499 | ||
1500 | static void dump_glock_func(struct gfs2_glock *gl) | |
1501 | { | |
1502 | dump_glock(NULL, gl); | |
f057f6cd SW |
1503 | } |
1504 | ||
b3b94faa DT |
1505 | /** |
1506 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1507 | * @sdp: the filesystem | |
1508 | * @wait: wait until it's all gone | |
1509 | * | |
1bdad606 | 1510 | * Called when unmounting the filesystem. |
b3b94faa DT |
1511 | */ |
1512 | ||
fefc03bf | 1513 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa | 1514 | { |
bc015cb8 | 1515 | glock_hash_walk(clear_glock, sdp); |
8f05228e SW |
1516 | flush_workqueue(glock_workqueue); |
1517 | wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0); | |
bc015cb8 | 1518 | glock_hash_walk(dump_glock_func, sdp); |
b3b94faa DT |
1519 | } |
1520 | ||
813e0c46 SW |
1521 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1522 | { | |
1523 | struct gfs2_glock *gl = ip->i_gl; | |
1524 | int ret; | |
1525 | ||
1526 | ret = gfs2_truncatei_resume(ip); | |
1527 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1528 | ||
1529 | spin_lock(&gl->gl_spin); | |
1530 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1531 | run_queue(gl, 1); | |
1532 | spin_unlock(&gl->gl_spin); | |
1533 | } | |
1534 | ||
6802e340 | 1535 | static const char *state2str(unsigned state) |
04b933f2 | 1536 | { |
6802e340 SW |
1537 | switch(state) { |
1538 | case LM_ST_UNLOCKED: | |
1539 | return "UN"; | |
1540 | case LM_ST_SHARED: | |
1541 | return "SH"; | |
1542 | case LM_ST_DEFERRED: | |
1543 | return "DF"; | |
1544 | case LM_ST_EXCLUSIVE: | |
1545 | return "EX"; | |
1546 | } | |
1547 | return "??"; | |
1548 | } | |
1549 | ||
1550 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1551 | { | |
1552 | char *p = buf; | |
1553 | if (flags & LM_FLAG_TRY) | |
1554 | *p++ = 't'; | |
1555 | if (flags & LM_FLAG_TRY_1CB) | |
1556 | *p++ = 'T'; | |
1557 | if (flags & LM_FLAG_NOEXP) | |
1558 | *p++ = 'e'; | |
1559 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1560 | *p++ = 'A'; |
6802e340 SW |
1561 | if (flags & LM_FLAG_PRIORITY) |
1562 | *p++ = 'p'; | |
1563 | if (flags & GL_ASYNC) | |
1564 | *p++ = 'a'; | |
1565 | if (flags & GL_EXACT) | |
1566 | *p++ = 'E'; | |
6802e340 SW |
1567 | if (flags & GL_NOCACHE) |
1568 | *p++ = 'c'; | |
1569 | if (test_bit(HIF_HOLDER, &iflags)) | |
1570 | *p++ = 'H'; | |
1571 | if (test_bit(HIF_WAIT, &iflags)) | |
1572 | *p++ = 'W'; | |
1573 | if (test_bit(HIF_FIRST, &iflags)) | |
1574 | *p++ = 'F'; | |
1575 | *p = 0; | |
1576 | return buf; | |
04b933f2 RP |
1577 | } |
1578 | ||
b3b94faa DT |
1579 | /** |
1580 | * dump_holder - print information about a glock holder | |
6802e340 | 1581 | * @seq: the seq_file struct |
b3b94faa DT |
1582 | * @gh: the glock holder |
1583 | * | |
1584 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1585 | */ | |
1586 | ||
6802e340 | 1587 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1588 | { |
6802e340 | 1589 | struct task_struct *gh_owner = NULL; |
6802e340 | 1590 | char flags_buf[32]; |
b3b94faa | 1591 | |
6802e340 | 1592 | if (gh->gh_owner_pid) |
b1e058da | 1593 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
cc18152e JP |
1594 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n", |
1595 | state2str(gh->gh_state), | |
1596 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1597 | gh->gh_error, | |
1598 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1599 | gh_owner ? gh_owner->comm : "(ended)", | |
1600 | (void *)gh->gh_ip); | |
7c52b166 | 1601 | return 0; |
b3b94faa DT |
1602 | } |
1603 | ||
6802e340 SW |
1604 | static const char *gflags2str(char *buf, const unsigned long *gflags) |
1605 | { | |
1606 | char *p = buf; | |
1607 | if (test_bit(GLF_LOCK, gflags)) | |
1608 | *p++ = 'l'; | |
6802e340 SW |
1609 | if (test_bit(GLF_DEMOTE, gflags)) |
1610 | *p++ = 'D'; | |
1611 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1612 | *p++ = 'd'; | |
1613 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1614 | *p++ = 'p'; | |
1615 | if (test_bit(GLF_DIRTY, gflags)) | |
1616 | *p++ = 'y'; | |
1617 | if (test_bit(GLF_LFLUSH, gflags)) | |
1618 | *p++ = 'f'; | |
1619 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1620 | *p++ = 'i'; | |
1621 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1622 | *p++ = 'r'; | |
f057f6cd | 1623 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1624 | *p++ = 'I'; |
f057f6cd SW |
1625 | if (test_bit(GLF_FROZEN, gflags)) |
1626 | *p++ = 'F'; | |
7b5e3d5f SW |
1627 | if (test_bit(GLF_QUEUED, gflags)) |
1628 | *p++ = 'q'; | |
6802e340 SW |
1629 | *p = 0; |
1630 | return buf; | |
b3b94faa DT |
1631 | } |
1632 | ||
1633 | /** | |
6802e340 SW |
1634 | * __dump_glock - print information about a glock |
1635 | * @seq: The seq_file struct | |
b3b94faa | 1636 | * @gl: the glock |
6802e340 SW |
1637 | * |
1638 | * The file format is as follows: | |
1639 | * One line per object, capital letters are used to indicate objects | |
1640 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1641 | * other objects are indented by a single space and follow the glock to | |
1642 | * which they are related. Fields are indicated by lower case letters | |
1643 | * followed by a colon and the field value, except for strings which are in | |
1644 | * [] so that its possible to see if they are composed of spaces for | |
1645 | * example. The field's are n = number (id of the object), f = flags, | |
1646 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1647 | * |
1648 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1649 | */ | |
1650 | ||
6802e340 | 1651 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1652 | { |
6802e340 SW |
1653 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1654 | unsigned long long dtime; | |
1655 | const struct gfs2_holder *gh; | |
1656 | char gflags_buf[32]; | |
1657 | int error = 0; | |
b3b94faa | 1658 | |
6802e340 SW |
1659 | dtime = jiffies - gl->gl_demote_time; |
1660 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1661 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1662 | dtime = 0; | |
4818972e | 1663 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d r:%d\n", |
6802e340 SW |
1664 | state2str(gl->gl_state), |
1665 | gl->gl_name.ln_type, | |
1666 | (unsigned long long)gl->gl_name.ln_number, | |
1667 | gflags2str(gflags_buf, &gl->gl_flags), | |
1668 | state2str(gl->gl_target), | |
1669 | state2str(gl->gl_demote_state), dtime, | |
6802e340 SW |
1670 | atomic_read(&gl->gl_ail_count), |
1671 | atomic_read(&gl->gl_ref)); | |
b3b94faa | 1672 | |
b3b94faa | 1673 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1674 | error = dump_holder(seq, gh); |
b3b94faa DT |
1675 | if (error) |
1676 | goto out; | |
1677 | } | |
6802e340 SW |
1678 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1679 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1680 | out: |
b3b94faa DT |
1681 | return error; |
1682 | } | |
1683 | ||
6802e340 | 1684 | |
b3b94faa | 1685 | |
8fbbfd21 | 1686 | |
85d1da67 SW |
1687 | int __init gfs2_glock_init(void) |
1688 | { | |
1689 | unsigned i; | |
1690 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
bc015cb8 | 1691 | INIT_HLIST_BL_HEAD(&gl_hash_table[i]); |
087efdd3 | 1692 | } |
8fbbfd21 | 1693 | |
d2115778 | 1694 | glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | |
58a69cb4 | 1695 | WQ_HIGHPRI | WQ_FREEZABLE, 0); |
97cc1025 | 1696 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1697 | return PTR_ERR(glock_workqueue); |
d2115778 | 1698 | gfs2_delete_workqueue = alloc_workqueue("delete_workqueue", |
58a69cb4 | 1699 | WQ_MEM_RECLAIM | WQ_FREEZABLE, |
d2115778 | 1700 | 0); |
b94a170e BM |
1701 | if (IS_ERR(gfs2_delete_workqueue)) { |
1702 | destroy_workqueue(glock_workqueue); | |
1703 | return PTR_ERR(gfs2_delete_workqueue); | |
1704 | } | |
97cc1025 SW |
1705 | |
1706 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1707 | |
85d1da67 SW |
1708 | return 0; |
1709 | } | |
1710 | ||
8fbbfd21 SW |
1711 | void gfs2_glock_exit(void) |
1712 | { | |
97cc1025 | 1713 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1714 | destroy_workqueue(glock_workqueue); |
b94a170e | 1715 | destroy_workqueue(gfs2_delete_workqueue); |
8fbbfd21 SW |
1716 | } |
1717 | ||
bc015cb8 SW |
1718 | static inline struct gfs2_glock *glock_hash_chain(unsigned hash) |
1719 | { | |
1720 | return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]), | |
1721 | struct gfs2_glock, gl_list); | |
1722 | } | |
1723 | ||
1724 | static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl) | |
1725 | { | |
7e32d026 | 1726 | return hlist_bl_entry(rcu_dereference(gl->gl_list.next), |
bc015cb8 SW |
1727 | struct gfs2_glock, gl_list); |
1728 | } | |
1729 | ||
6802e340 | 1730 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1731 | { |
7b08fc62 SW |
1732 | struct gfs2_glock *gl; |
1733 | ||
bc015cb8 SW |
1734 | do { |
1735 | gl = gi->gl; | |
1736 | if (gl) { | |
1737 | gi->gl = glock_hash_next(gl); | |
1738 | } else { | |
1739 | gi->gl = glock_hash_chain(gi->hash); | |
1740 | } | |
1741 | while (gi->gl == NULL) { | |
1742 | gi->hash++; | |
1743 | if (gi->hash >= GFS2_GL_HASH_SIZE) { | |
1744 | rcu_read_unlock(); | |
1745 | return 1; | |
1746 | } | |
1747 | gi->gl = glock_hash_chain(gi->hash); | |
1748 | } | |
1749 | /* Skip entries for other sb and dead entries */ | |
1750 | } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0); | |
a947e033 | 1751 | |
7c52b166 RP |
1752 | return 0; |
1753 | } | |
1754 | ||
6802e340 | 1755 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1756 | { |
6802e340 | 1757 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1758 | loff_t n = *pos; |
1759 | ||
6802e340 | 1760 | gi->hash = 0; |
bc015cb8 | 1761 | rcu_read_lock(); |
7c52b166 | 1762 | |
6802e340 | 1763 | do { |
bc015cb8 | 1764 | if (gfs2_glock_iter_next(gi)) |
7c52b166 | 1765 | return NULL; |
6802e340 | 1766 | } while (n--); |
7c52b166 | 1767 | |
6802e340 | 1768 | return gi->gl; |
7c52b166 RP |
1769 | } |
1770 | ||
6802e340 | 1771 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1772 | loff_t *pos) |
1773 | { | |
6802e340 | 1774 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1775 | |
1776 | (*pos)++; | |
1777 | ||
bc015cb8 | 1778 | if (gfs2_glock_iter_next(gi)) |
7c52b166 | 1779 | return NULL; |
7c52b166 | 1780 | |
6802e340 | 1781 | return gi->gl; |
7c52b166 RP |
1782 | } |
1783 | ||
6802e340 | 1784 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1785 | { |
6802e340 | 1786 | struct gfs2_glock_iter *gi = seq->private; |
bc015cb8 SW |
1787 | |
1788 | if (gi->gl) | |
1789 | rcu_read_unlock(); | |
1790 | gi->gl = NULL; | |
7c52b166 RP |
1791 | } |
1792 | ||
6802e340 | 1793 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1794 | { |
6802e340 | 1795 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1796 | } |
1797 | ||
4ef29002 | 1798 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1799 | .start = gfs2_glock_seq_start, |
1800 | .next = gfs2_glock_seq_next, | |
1801 | .stop = gfs2_glock_seq_stop, | |
1802 | .show = gfs2_glock_seq_show, | |
1803 | }; | |
1804 | ||
1805 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1806 | { | |
6802e340 SW |
1807 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1808 | sizeof(struct gfs2_glock_iter)); | |
1809 | if (ret == 0) { | |
1810 | struct seq_file *seq = file->private_data; | |
1811 | struct gfs2_glock_iter *gi = seq->private; | |
1812 | gi->sdp = inode->i_private; | |
1813 | } | |
1814 | return ret; | |
7c52b166 RP |
1815 | } |
1816 | ||
1817 | static const struct file_operations gfs2_debug_fops = { | |
1818 | .owner = THIS_MODULE, | |
1819 | .open = gfs2_debugfs_open, | |
1820 | .read = seq_read, | |
1821 | .llseek = seq_lseek, | |
6802e340 | 1822 | .release = seq_release_private, |
7c52b166 RP |
1823 | }; |
1824 | ||
1825 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1826 | { | |
5f882096 RP |
1827 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1828 | if (!sdp->debugfs_dir) | |
1829 | return -ENOMEM; | |
1830 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1831 | S_IFREG | S_IRUGO, | |
1832 | sdp->debugfs_dir, sdp, | |
1833 | &gfs2_debug_fops); | |
1834 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1835 | return -ENOMEM; |
1836 | ||
1837 | return 0; | |
1838 | } | |
1839 | ||
1840 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1841 | { | |
5f882096 RP |
1842 | if (sdp && sdp->debugfs_dir) { |
1843 | if (sdp->debugfs_dentry_glocks) { | |
1844 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1845 | sdp->debugfs_dentry_glocks = NULL; | |
1846 | } | |
1847 | debugfs_remove(sdp->debugfs_dir); | |
1848 | sdp->debugfs_dir = NULL; | |
1849 | } | |
7c52b166 RP |
1850 | } |
1851 | ||
1852 | int gfs2_register_debugfs(void) | |
1853 | { | |
1854 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1855 | return gfs2_root ? 0 : -ENOMEM; | |
1856 | } | |
1857 | ||
1858 | void gfs2_unregister_debugfs(void) | |
1859 | { | |
1860 | debugfs_remove(gfs2_root); | |
5f882096 | 1861 | gfs2_root = NULL; |
7c52b166 | 1862 | } |