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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 | { | |
1879fd6a | 96 | hlist_bl_lock(&gl_hash_table[hash]); |
bc015cb8 | 97 | } |
b3b94faa | 98 | |
bc015cb8 SW |
99 | static inline void spin_unlock_bucket(unsigned int hash) |
100 | { | |
1879fd6a | 101 | hlist_bl_unlock(&gl_hash_table[hash]); |
bc015cb8 | 102 | } |
b3b94faa | 103 | |
fc0e38da | 104 | static void gfs2_glock_dealloc(struct rcu_head *rcu) |
b3b94faa | 105 | { |
bc015cb8 | 106 | struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); |
b3b94faa | 107 | |
bc015cb8 SW |
108 | if (gl->gl_ops->go_flags & GLOF_ASPACE) |
109 | kmem_cache_free(gfs2_glock_aspace_cachep, gl); | |
110 | else | |
111 | kmem_cache_free(gfs2_glock_cachep, gl); | |
fc0e38da SW |
112 | } |
113 | ||
114 | void gfs2_glock_free(struct gfs2_glock *gl) | |
b3b94faa DT |
115 | { |
116 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
b3b94faa | 117 | |
fc0e38da | 118 | call_rcu(&gl->gl_rcu, gfs2_glock_dealloc); |
bc015cb8 SW |
119 | if (atomic_dec_and_test(&sdp->sd_glock_disposal)) |
120 | wake_up(&sdp->sd_glock_wait); | |
b3b94faa DT |
121 | } |
122 | ||
123 | /** | |
124 | * gfs2_glock_hold() - increment reference count on glock | |
125 | * @gl: The glock to hold | |
126 | * | |
127 | */ | |
128 | ||
b94a170e | 129 | void gfs2_glock_hold(struct gfs2_glock *gl) |
b3b94faa | 130 | { |
d8348de0 | 131 | GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0); |
16feb9fe | 132 | atomic_inc(&gl->gl_ref); |
b3b94faa DT |
133 | } |
134 | ||
8ff22a6f BM |
135 | /** |
136 | * demote_ok - Check to see if it's ok to unlock a glock | |
137 | * @gl: the glock | |
138 | * | |
139 | * Returns: 1 if it's ok | |
140 | */ | |
141 | ||
142 | static int demote_ok(const struct gfs2_glock *gl) | |
143 | { | |
144 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
145 | ||
146 | if (gl->gl_state == LM_ST_UNLOCKED) | |
147 | return 0; | |
f42ab085 | 148 | if (!list_empty(&gl->gl_holders)) |
8ff22a6f BM |
149 | return 0; |
150 | if (glops->go_demote_ok) | |
151 | return glops->go_demote_ok(gl); | |
152 | return 1; | |
153 | } | |
154 | ||
bc015cb8 | 155 | |
29687a2a SW |
156 | void gfs2_glock_add_to_lru(struct gfs2_glock *gl) |
157 | { | |
158 | spin_lock(&lru_lock); | |
159 | ||
160 | if (!list_empty(&gl->gl_lru)) | |
161 | list_del_init(&gl->gl_lru); | |
162 | else | |
163 | atomic_inc(&lru_count); | |
164 | ||
165 | list_add_tail(&gl->gl_lru, &lru_list); | |
627c10b7 | 166 | set_bit(GLF_LRU, &gl->gl_flags); |
29687a2a SW |
167 | spin_unlock(&lru_lock); |
168 | } | |
169 | ||
4043b886 | 170 | static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl) |
f42ab085 | 171 | { |
f42ab085 SW |
172 | if (!list_empty(&gl->gl_lru)) { |
173 | list_del_init(&gl->gl_lru); | |
174 | atomic_dec(&lru_count); | |
175 | clear_bit(GLF_LRU, &gl->gl_flags); | |
176 | } | |
4043b886 SW |
177 | } |
178 | ||
179 | static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) | |
180 | { | |
181 | spin_lock(&lru_lock); | |
182 | __gfs2_glock_remove_from_lru(gl); | |
f42ab085 SW |
183 | spin_unlock(&lru_lock); |
184 | } | |
185 | ||
97cc1025 | 186 | /** |
bc015cb8 | 187 | * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list |
97cc1025 SW |
188 | * @gl: the glock |
189 | * | |
bc015cb8 SW |
190 | * If the glock is demotable, then we add it (or move it) to the end |
191 | * of the glock LRU list. | |
97cc1025 SW |
192 | */ |
193 | ||
bc015cb8 | 194 | static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) |
97cc1025 | 195 | { |
29687a2a SW |
196 | if (demote_ok(gl)) |
197 | gfs2_glock_add_to_lru(gl); | |
97cc1025 SW |
198 | } |
199 | ||
8ff22a6f BM |
200 | /** |
201 | * gfs2_glock_put_nolock() - Decrement reference count on glock | |
202 | * @gl: The glock to put | |
203 | * | |
204 | * This function should only be used if the caller has its own reference | |
205 | * to the glock, in addition to the one it is dropping. | |
206 | */ | |
207 | ||
b94a170e | 208 | void gfs2_glock_put_nolock(struct gfs2_glock *gl) |
8ff22a6f BM |
209 | { |
210 | if (atomic_dec_and_test(&gl->gl_ref)) | |
211 | GLOCK_BUG_ON(gl, 1); | |
8ff22a6f BM |
212 | } |
213 | ||
b3b94faa DT |
214 | /** |
215 | * gfs2_glock_put() - Decrement reference count on glock | |
216 | * @gl: The glock to put | |
217 | * | |
218 | */ | |
219 | ||
bc015cb8 | 220 | void gfs2_glock_put(struct gfs2_glock *gl) |
b3b94faa | 221 | { |
bc015cb8 SW |
222 | struct gfs2_sbd *sdp = gl->gl_sbd; |
223 | struct address_space *mapping = gfs2_glock2aspace(gl); | |
b3b94faa | 224 | |
4043b886 SW |
225 | if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) { |
226 | __gfs2_glock_remove_from_lru(gl); | |
227 | spin_unlock(&lru_lock); | |
bc015cb8 SW |
228 | spin_lock_bucket(gl->gl_hash); |
229 | hlist_bl_del_rcu(&gl->gl_list); | |
230 | spin_unlock_bucket(gl->gl_hash); | |
6802e340 | 231 | GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
bc015cb8 SW |
232 | GLOCK_BUG_ON(gl, mapping && mapping->nrpages); |
233 | trace_gfs2_glock_put(gl); | |
234 | sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); | |
b3b94faa | 235 | } |
b3b94faa DT |
236 | } |
237 | ||
b3b94faa DT |
238 | /** |
239 | * search_bucket() - Find struct gfs2_glock by lock number | |
240 | * @bucket: the bucket to search | |
241 | * @name: The lock name | |
242 | * | |
243 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
244 | */ | |
245 | ||
37b2fa6a | 246 | static struct gfs2_glock *search_bucket(unsigned int hash, |
899be4d3 | 247 | const struct gfs2_sbd *sdp, |
d6a53727 | 248 | const struct lm_lockname *name) |
b3b94faa DT |
249 | { |
250 | struct gfs2_glock *gl; | |
bc015cb8 | 251 | struct hlist_bl_node *h; |
b3b94faa | 252 | |
bc015cb8 | 253 | hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) { |
b3b94faa DT |
254 | if (!lm_name_equal(&gl->gl_name, name)) |
255 | continue; | |
899be4d3 SW |
256 | if (gl->gl_sbd != sdp) |
257 | continue; | |
bc015cb8 SW |
258 | if (atomic_inc_not_zero(&gl->gl_ref)) |
259 | return gl; | |
b3b94faa DT |
260 | } |
261 | ||
262 | return NULL; | |
263 | } | |
264 | ||
6802e340 SW |
265 | /** |
266 | * may_grant - check if its ok to grant a new lock | |
267 | * @gl: The glock | |
268 | * @gh: The lock request which we wish to grant | |
269 | * | |
270 | * Returns: true if its ok to grant the lock | |
271 | */ | |
272 | ||
273 | static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) | |
274 | { | |
275 | const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); | |
276 | if ((gh->gh_state == LM_ST_EXCLUSIVE || | |
277 | gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) | |
278 | return 0; | |
279 | if (gl->gl_state == gh->gh_state) | |
280 | return 1; | |
281 | if (gh->gh_flags & GL_EXACT) | |
282 | return 0; | |
209806ab SW |
283 | if (gl->gl_state == LM_ST_EXCLUSIVE) { |
284 | if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED) | |
285 | return 1; | |
286 | if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED) | |
287 | return 1; | |
288 | } | |
6802e340 SW |
289 | if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) |
290 | return 1; | |
291 | return 0; | |
292 | } | |
293 | ||
294 | static void gfs2_holder_wake(struct gfs2_holder *gh) | |
295 | { | |
296 | clear_bit(HIF_WAIT, &gh->gh_iflags); | |
297 | smp_mb__after_clear_bit(); | |
298 | wake_up_bit(&gh->gh_iflags, HIF_WAIT); | |
299 | } | |
300 | ||
d5341a92 SW |
301 | /** |
302 | * do_error - Something unexpected has happened during a lock request | |
303 | * | |
304 | */ | |
305 | ||
306 | static inline void do_error(struct gfs2_glock *gl, const int ret) | |
307 | { | |
308 | struct gfs2_holder *gh, *tmp; | |
309 | ||
310 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
311 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
312 | continue; | |
313 | if (ret & LM_OUT_ERROR) | |
314 | gh->gh_error = -EIO; | |
315 | else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) | |
316 | gh->gh_error = GLR_TRYFAILED; | |
317 | else | |
318 | continue; | |
319 | list_del_init(&gh->gh_list); | |
320 | trace_gfs2_glock_queue(gh, 0); | |
321 | gfs2_holder_wake(gh); | |
322 | } | |
323 | } | |
324 | ||
6802e340 SW |
325 | /** |
326 | * do_promote - promote as many requests as possible on the current queue | |
327 | * @gl: The glock | |
328 | * | |
813e0c46 SW |
329 | * Returns: 1 if there is a blocked holder at the head of the list, or 2 |
330 | * if a type specific operation is underway. | |
6802e340 SW |
331 | */ |
332 | ||
333 | static int do_promote(struct gfs2_glock *gl) | |
55ba474d HH |
334 | __releases(&gl->gl_spin) |
335 | __acquires(&gl->gl_spin) | |
6802e340 SW |
336 | { |
337 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
338 | struct gfs2_holder *gh, *tmp; | |
339 | int ret; | |
340 | ||
341 | restart: | |
342 | list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { | |
343 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
344 | continue; | |
345 | if (may_grant(gl, gh)) { | |
346 | if (gh->gh_list.prev == &gl->gl_holders && | |
347 | glops->go_lock) { | |
348 | spin_unlock(&gl->gl_spin); | |
349 | /* FIXME: eliminate this eventually */ | |
350 | ret = glops->go_lock(gh); | |
351 | spin_lock(&gl->gl_spin); | |
352 | if (ret) { | |
813e0c46 SW |
353 | if (ret == 1) |
354 | return 2; | |
6802e340 SW |
355 | gh->gh_error = ret; |
356 | list_del_init(&gh->gh_list); | |
63997775 | 357 | trace_gfs2_glock_queue(gh, 0); |
6802e340 SW |
358 | gfs2_holder_wake(gh); |
359 | goto restart; | |
360 | } | |
361 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 362 | trace_gfs2_promote(gh, 1); |
6802e340 SW |
363 | gfs2_holder_wake(gh); |
364 | goto restart; | |
365 | } | |
366 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
63997775 | 367 | trace_gfs2_promote(gh, 0); |
6802e340 SW |
368 | gfs2_holder_wake(gh); |
369 | continue; | |
370 | } | |
371 | if (gh->gh_list.prev == &gl->gl_holders) | |
372 | return 1; | |
d5341a92 | 373 | do_error(gl, 0); |
6802e340 SW |
374 | break; |
375 | } | |
376 | return 0; | |
377 | } | |
378 | ||
6802e340 SW |
379 | /** |
380 | * find_first_waiter - find the first gh that's waiting for the glock | |
381 | * @gl: the glock | |
382 | */ | |
383 | ||
384 | static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) | |
385 | { | |
386 | struct gfs2_holder *gh; | |
387 | ||
388 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
389 | if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
390 | return gh; | |
391 | } | |
392 | return NULL; | |
393 | } | |
394 | ||
395 | /** | |
396 | * state_change - record that the glock is now in a different state | |
397 | * @gl: the glock | |
398 | * @new_state the new state | |
399 | * | |
400 | */ | |
401 | ||
402 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
403 | { | |
404 | int held1, held2; | |
405 | ||
406 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
407 | held2 = (new_state != LM_ST_UNLOCKED); | |
408 | ||
409 | if (held1 != held2) { | |
410 | if (held2) | |
411 | gfs2_glock_hold(gl); | |
412 | else | |
8ff22a6f | 413 | gfs2_glock_put_nolock(gl); |
6802e340 | 414 | } |
7b5e3d5f SW |
415 | if (held1 && held2 && list_empty(&gl->gl_holders)) |
416 | clear_bit(GLF_QUEUED, &gl->gl_flags); | |
6802e340 | 417 | |
7cf8dcd3 BP |
418 | if (new_state != gl->gl_target) |
419 | /* shorten our minimum hold time */ | |
420 | gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR, | |
421 | GL_GLOCK_MIN_HOLD); | |
6802e340 SW |
422 | gl->gl_state = new_state; |
423 | gl->gl_tchange = jiffies; | |
424 | } | |
425 | ||
426 | static void gfs2_demote_wake(struct gfs2_glock *gl) | |
427 | { | |
428 | gl->gl_demote_state = LM_ST_EXCLUSIVE; | |
429 | clear_bit(GLF_DEMOTE, &gl->gl_flags); | |
430 | smp_mb__after_clear_bit(); | |
431 | wake_up_bit(&gl->gl_flags, GLF_DEMOTE); | |
432 | } | |
433 | ||
434 | /** | |
435 | * finish_xmote - The DLM has replied to one of our lock requests | |
436 | * @gl: The glock | |
437 | * @ret: The status from the DLM | |
438 | * | |
439 | */ | |
440 | ||
441 | static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) | |
442 | { | |
443 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
444 | struct gfs2_holder *gh; | |
445 | unsigned state = ret & LM_OUT_ST_MASK; | |
813e0c46 | 446 | int rv; |
6802e340 SW |
447 | |
448 | spin_lock(&gl->gl_spin); | |
63997775 | 449 | trace_gfs2_glock_state_change(gl, state); |
6802e340 SW |
450 | state_change(gl, state); |
451 | gh = find_first_waiter(gl); | |
452 | ||
453 | /* Demote to UN request arrived during demote to SH or DF */ | |
454 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && | |
455 | state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) | |
456 | gl->gl_target = LM_ST_UNLOCKED; | |
457 | ||
458 | /* Check for state != intended state */ | |
459 | if (unlikely(state != gl->gl_target)) { | |
460 | if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { | |
461 | /* move to back of queue and try next entry */ | |
462 | if (ret & LM_OUT_CANCELED) { | |
463 | if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) | |
464 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
465 | gh = find_first_waiter(gl); | |
466 | gl->gl_target = gh->gh_state; | |
467 | goto retry; | |
468 | } | |
469 | /* Some error or failed "try lock" - report it */ | |
470 | if ((ret & LM_OUT_ERROR) || | |
471 | (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { | |
472 | gl->gl_target = gl->gl_state; | |
473 | do_error(gl, ret); | |
474 | goto out; | |
475 | } | |
476 | } | |
477 | switch(state) { | |
478 | /* Unlocked due to conversion deadlock, try again */ | |
479 | case LM_ST_UNLOCKED: | |
480 | retry: | |
481 | do_xmote(gl, gh, gl->gl_target); | |
482 | break; | |
483 | /* Conversion fails, unlock and try again */ | |
484 | case LM_ST_SHARED: | |
485 | case LM_ST_DEFERRED: | |
486 | do_xmote(gl, gh, LM_ST_UNLOCKED); | |
487 | break; | |
488 | default: /* Everything else */ | |
489 | printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); | |
490 | GLOCK_BUG_ON(gl, 1); | |
491 | } | |
492 | spin_unlock(&gl->gl_spin); | |
6802e340 SW |
493 | return; |
494 | } | |
495 | ||
496 | /* Fast path - we got what we asked for */ | |
497 | if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) | |
498 | gfs2_demote_wake(gl); | |
499 | if (state != LM_ST_UNLOCKED) { | |
500 | if (glops->go_xmote_bh) { | |
6802e340 SW |
501 | spin_unlock(&gl->gl_spin); |
502 | rv = glops->go_xmote_bh(gl, gh); | |
6802e340 SW |
503 | spin_lock(&gl->gl_spin); |
504 | if (rv) { | |
505 | do_error(gl, rv); | |
506 | goto out; | |
507 | } | |
508 | } | |
813e0c46 SW |
509 | rv = do_promote(gl); |
510 | if (rv == 2) | |
511 | goto out_locked; | |
6802e340 SW |
512 | } |
513 | out: | |
514 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
813e0c46 | 515 | out_locked: |
6802e340 | 516 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
517 | } |
518 | ||
6802e340 SW |
519 | /** |
520 | * do_xmote - Calls the DLM to change the state of a lock | |
521 | * @gl: The lock state | |
522 | * @gh: The holder (only for promotes) | |
523 | * @target: The target lock state | |
524 | * | |
525 | */ | |
526 | ||
527 | static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) | |
55ba474d HH |
528 | __releases(&gl->gl_spin) |
529 | __acquires(&gl->gl_spin) | |
6802e340 SW |
530 | { |
531 | const struct gfs2_glock_operations *glops = gl->gl_ops; | |
532 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
533 | unsigned int lck_flags = gh ? gh->gh_flags : 0; | |
534 | int ret; | |
535 | ||
536 | lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | | |
537 | LM_FLAG_PRIORITY); | |
921169ca SW |
538 | GLOCK_BUG_ON(gl, gl->gl_state == target); |
539 | GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target); | |
6802e340 SW |
540 | if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && |
541 | glops->go_inval) { | |
542 | set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
543 | do_error(gl, 0); /* Fail queued try locks */ | |
544 | } | |
47a25380 | 545 | gl->gl_req = target; |
6802e340 SW |
546 | spin_unlock(&gl->gl_spin); |
547 | if (glops->go_xmote_th) | |
548 | glops->go_xmote_th(gl); | |
549 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
550 | glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); | |
551 | clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); | |
552 | ||
553 | gfs2_glock_hold(gl); | |
921169ca SW |
554 | if (sdp->sd_lockstruct.ls_ops->lm_lock) { |
555 | /* lock_dlm */ | |
556 | ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags); | |
557 | GLOCK_BUG_ON(gl, ret); | |
558 | } else { /* lock_nolock */ | |
559 | finish_xmote(gl, target); | |
6802e340 SW |
560 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
561 | gfs2_glock_put(gl); | |
6802e340 | 562 | } |
921169ca | 563 | |
6802e340 SW |
564 | spin_lock(&gl->gl_spin); |
565 | } | |
566 | ||
567 | /** | |
568 | * find_first_holder - find the first "holder" gh | |
569 | * @gl: the glock | |
570 | */ | |
571 | ||
572 | static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) | |
573 | { | |
574 | struct gfs2_holder *gh; | |
575 | ||
576 | if (!list_empty(&gl->gl_holders)) { | |
577 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
578 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
579 | return gh; | |
580 | } | |
581 | return NULL; | |
582 | } | |
583 | ||
584 | /** | |
585 | * run_queue - do all outstanding tasks related to a glock | |
586 | * @gl: The glock in question | |
587 | * @nonblock: True if we must not block in run_queue | |
588 | * | |
589 | */ | |
590 | ||
591 | static void run_queue(struct gfs2_glock *gl, const int nonblock) | |
55ba474d HH |
592 | __releases(&gl->gl_spin) |
593 | __acquires(&gl->gl_spin) | |
6802e340 SW |
594 | { |
595 | struct gfs2_holder *gh = NULL; | |
813e0c46 | 596 | int ret; |
6802e340 SW |
597 | |
598 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
599 | return; | |
600 | ||
601 | GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); | |
602 | ||
603 | if (test_bit(GLF_DEMOTE, &gl->gl_flags) && | |
604 | gl->gl_demote_state != gl->gl_state) { | |
605 | if (find_first_holder(gl)) | |
d8348de0 | 606 | goto out_unlock; |
6802e340 SW |
607 | if (nonblock) |
608 | goto out_sched; | |
609 | set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); | |
265d529c | 610 | GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
6802e340 SW |
611 | gl->gl_target = gl->gl_demote_state; |
612 | } else { | |
613 | if (test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
614 | gfs2_demote_wake(gl); | |
813e0c46 SW |
615 | ret = do_promote(gl); |
616 | if (ret == 0) | |
d8348de0 | 617 | goto out_unlock; |
813e0c46 | 618 | if (ret == 2) |
a228df63 | 619 | goto out; |
6802e340 SW |
620 | gh = find_first_waiter(gl); |
621 | gl->gl_target = gh->gh_state; | |
622 | if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) | |
623 | do_error(gl, 0); /* Fail queued try locks */ | |
624 | } | |
625 | do_xmote(gl, gh, gl->gl_target); | |
a228df63 | 626 | out: |
6802e340 SW |
627 | return; |
628 | ||
629 | out_sched: | |
7e71c55e SW |
630 | clear_bit(GLF_LOCK, &gl->gl_flags); |
631 | smp_mb__after_clear_bit(); | |
6802e340 SW |
632 | gfs2_glock_hold(gl); |
633 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
8ff22a6f | 634 | gfs2_glock_put_nolock(gl); |
7e71c55e SW |
635 | return; |
636 | ||
d8348de0 | 637 | out_unlock: |
6802e340 | 638 | clear_bit(GLF_LOCK, &gl->gl_flags); |
7e71c55e SW |
639 | smp_mb__after_clear_bit(); |
640 | return; | |
6802e340 SW |
641 | } |
642 | ||
b94a170e BM |
643 | static void delete_work_func(struct work_struct *work) |
644 | { | |
645 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete); | |
646 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
044b9414 | 647 | struct gfs2_inode *ip; |
b94a170e | 648 | struct inode *inode; |
044b9414 SW |
649 | u64 no_addr = gl->gl_name.ln_number; |
650 | ||
651 | ip = gl->gl_object; | |
652 | /* Note: Unsafe to dereference ip as we don't hold right refs/locks */ | |
b94a170e | 653 | |
b94a170e | 654 | if (ip) |
4667a0ec | 655 | inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1); |
044b9414 SW |
656 | else |
657 | inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED); | |
658 | if (inode && !IS_ERR(inode)) { | |
659 | d_prune_aliases(inode); | |
660 | iput(inode); | |
b94a170e BM |
661 | } |
662 | gfs2_glock_put(gl); | |
663 | } | |
664 | ||
c4f68a13 BM |
665 | static void glock_work_func(struct work_struct *work) |
666 | { | |
6802e340 | 667 | unsigned long delay = 0; |
c4f68a13 | 668 | struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
26bb7505 | 669 | int drop_ref = 0; |
c4f68a13 | 670 | |
26bb7505 | 671 | if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
6802e340 | 672 | finish_xmote(gl, gl->gl_reply); |
26bb7505 SW |
673 | drop_ref = 1; |
674 | } | |
c4f68a13 | 675 | spin_lock(&gl->gl_spin); |
f90e5b5b | 676 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
265d529c SW |
677 | gl->gl_state != LM_ST_UNLOCKED && |
678 | gl->gl_demote_state != LM_ST_EXCLUSIVE) { | |
6802e340 | 679 | unsigned long holdtime, now = jiffies; |
f90e5b5b | 680 | |
7cf8dcd3 | 681 | holdtime = gl->gl_tchange + gl->gl_hold_time; |
6802e340 SW |
682 | if (time_before(now, holdtime)) |
683 | delay = holdtime - now; | |
f90e5b5b BP |
684 | |
685 | if (!delay) { | |
686 | clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags); | |
687 | set_bit(GLF_DEMOTE, &gl->gl_flags); | |
688 | } | |
6802e340 SW |
689 | } |
690 | run_queue(gl, 0); | |
c4f68a13 | 691 | spin_unlock(&gl->gl_spin); |
7cf8dcd3 | 692 | if (!delay) |
6802e340 | 693 | gfs2_glock_put(gl); |
7cf8dcd3 BP |
694 | else { |
695 | if (gl->gl_name.ln_type != LM_TYPE_INODE) | |
696 | delay = 0; | |
697 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) | |
698 | gfs2_glock_put(gl); | |
699 | } | |
26bb7505 SW |
700 | if (drop_ref) |
701 | gfs2_glock_put(gl); | |
c4f68a13 BM |
702 | } |
703 | ||
b3b94faa DT |
704 | /** |
705 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
706 | * @sdp: The GFS2 superblock | |
707 | * @number: the lock number | |
708 | * @glops: The glock_operations to use | |
709 | * @create: If 0, don't create the glock if it doesn't exist | |
710 | * @glp: the glock is returned here | |
711 | * | |
712 | * This does not lock a glock, just finds/creates structures for one. | |
713 | * | |
714 | * Returns: errno | |
715 | */ | |
716 | ||
cd915493 | 717 | int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 | 718 | const struct gfs2_glock_operations *glops, int create, |
b3b94faa DT |
719 | struct gfs2_glock **glp) |
720 | { | |
009d8518 | 721 | struct super_block *s = sdp->sd_vfs; |
37b2fa6a | 722 | struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type }; |
b3b94faa | 723 | struct gfs2_glock *gl, *tmp; |
37b2fa6a | 724 | unsigned int hash = gl_hash(sdp, &name); |
009d8518 | 725 | struct address_space *mapping; |
bc015cb8 | 726 | struct kmem_cache *cachep; |
b3b94faa | 727 | |
bc015cb8 | 728 | rcu_read_lock(); |
37b2fa6a | 729 | gl = search_bucket(hash, sdp, &name); |
bc015cb8 | 730 | rcu_read_unlock(); |
b3b94faa | 731 | |
64d576ba SW |
732 | *glp = gl; |
733 | if (gl) | |
b3b94faa | 734 | return 0; |
64d576ba SW |
735 | if (!create) |
736 | return -ENOENT; | |
b3b94faa | 737 | |
009d8518 | 738 | if (glops->go_flags & GLOF_ASPACE) |
bc015cb8 | 739 | cachep = gfs2_glock_aspace_cachep; |
009d8518 | 740 | else |
bc015cb8 SW |
741 | cachep = gfs2_glock_cachep; |
742 | gl = kmem_cache_alloc(cachep, GFP_KERNEL); | |
b3b94faa DT |
743 | if (!gl) |
744 | return -ENOMEM; | |
745 | ||
8f05228e | 746 | atomic_inc(&sdp->sd_glock_disposal); |
ec45d9f5 | 747 | gl->gl_flags = 0; |
b3b94faa | 748 | gl->gl_name = name; |
16feb9fe | 749 | atomic_set(&gl->gl_ref, 1); |
b3b94faa | 750 | gl->gl_state = LM_ST_UNLOCKED; |
6802e340 | 751 | gl->gl_target = LM_ST_UNLOCKED; |
c4f68a13 | 752 | gl->gl_demote_state = LM_ST_EXCLUSIVE; |
37b2fa6a | 753 | gl->gl_hash = hash; |
b3b94faa | 754 | gl->gl_ops = glops; |
f057f6cd SW |
755 | snprintf(gl->gl_strname, GDLM_STRNAME_BYTES, "%8x%16llx", name.ln_type, (unsigned long long)number); |
756 | memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); | |
757 | gl->gl_lksb.sb_lvbptr = gl->gl_lvb; | |
c4f68a13 | 758 | gl->gl_tchange = jiffies; |
ec45d9f5 | 759 | gl->gl_object = NULL; |
b3b94faa | 760 | gl->gl_sbd = sdp; |
7cf8dcd3 | 761 | gl->gl_hold_time = GL_GLOCK_DFT_HOLD; |
c4f68a13 | 762 | INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
b94a170e | 763 | INIT_WORK(&gl->gl_delete, delete_work_func); |
b3b94faa | 764 | |
009d8518 SW |
765 | mapping = gfs2_glock2aspace(gl); |
766 | if (mapping) { | |
767 | mapping->a_ops = &gfs2_meta_aops; | |
768 | mapping->host = s->s_bdev->bd_inode; | |
769 | mapping->flags = 0; | |
770 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
771 | mapping->assoc_mapping = NULL; | |
772 | mapping->backing_dev_info = s->s_bdi; | |
773 | mapping->writeback_index = 0; | |
b3b94faa DT |
774 | } |
775 | ||
bc015cb8 | 776 | spin_lock_bucket(hash); |
37b2fa6a | 777 | tmp = search_bucket(hash, sdp, &name); |
b3b94faa | 778 | if (tmp) { |
bc015cb8 SW |
779 | spin_unlock_bucket(hash); |
780 | kmem_cache_free(cachep, gl); | |
fc0e38da | 781 | atomic_dec(&sdp->sd_glock_disposal); |
b3b94faa DT |
782 | gl = tmp; |
783 | } else { | |
bc015cb8 SW |
784 | hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]); |
785 | spin_unlock_bucket(hash); | |
b3b94faa DT |
786 | } |
787 | ||
788 | *glp = gl; | |
789 | ||
790 | return 0; | |
b3b94faa DT |
791 | } |
792 | ||
793 | /** | |
794 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
795 | * @gl: the glock | |
796 | * @state: the state we're requesting | |
797 | * @flags: the modifier flags | |
798 | * @gh: the holder structure | |
799 | * | |
800 | */ | |
801 | ||
190562bd | 802 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, |
b3b94faa DT |
803 | struct gfs2_holder *gh) |
804 | { | |
805 | INIT_LIST_HEAD(&gh->gh_list); | |
806 | gh->gh_gl = gl; | |
d0dc80db | 807 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b1e058da | 808 | gh->gh_owner_pid = get_pid(task_pid(current)); |
b3b94faa DT |
809 | gh->gh_state = state; |
810 | gh->gh_flags = flags; | |
811 | gh->gh_error = 0; | |
812 | gh->gh_iflags = 0; | |
b3b94faa DT |
813 | gfs2_glock_hold(gl); |
814 | } | |
815 | ||
816 | /** | |
817 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
818 | * @state: the state we're requesting | |
819 | * @flags: the modifier flags | |
820 | * @gh: the holder structure | |
821 | * | |
822 | * Don't mess with the glock. | |
823 | * | |
824 | */ | |
825 | ||
190562bd | 826 | void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh) |
b3b94faa DT |
827 | { |
828 | gh->gh_state = state; | |
579b78a4 | 829 | gh->gh_flags = flags; |
3b8249f6 | 830 | gh->gh_iflags = 0; |
d0dc80db | 831 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
1a0eae88 BP |
832 | if (gh->gh_owner_pid) |
833 | put_pid(gh->gh_owner_pid); | |
834 | gh->gh_owner_pid = get_pid(task_pid(current)); | |
b3b94faa DT |
835 | } |
836 | ||
837 | /** | |
838 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
839 | * @gh: the holder structure | |
840 | * | |
841 | */ | |
842 | ||
843 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
844 | { | |
b1e058da | 845 | put_pid(gh->gh_owner_pid); |
b3b94faa DT |
846 | gfs2_glock_put(gh->gh_gl); |
847 | gh->gh_gl = NULL; | |
d0dc80db | 848 | gh->gh_ip = 0; |
b3b94faa DT |
849 | } |
850 | ||
fe64d517 SW |
851 | /** |
852 | * gfs2_glock_holder_wait | |
853 | * @word: unused | |
854 | * | |
855 | * This function and gfs2_glock_demote_wait both show up in the WCHAN | |
856 | * field. Thus I've separated these otherwise identical functions in | |
857 | * order to be more informative to the user. | |
858 | */ | |
859 | ||
860 | static int gfs2_glock_holder_wait(void *word) | |
fee852e3 SW |
861 | { |
862 | schedule(); | |
863 | return 0; | |
864 | } | |
865 | ||
fe64d517 SW |
866 | static int gfs2_glock_demote_wait(void *word) |
867 | { | |
868 | schedule(); | |
869 | return 0; | |
870 | } | |
871 | ||
6802e340 | 872 | static void wait_on_holder(struct gfs2_holder *gh) |
da755fdb | 873 | { |
7cf8dcd3 BP |
874 | unsigned long time1 = jiffies; |
875 | ||
6802e340 | 876 | might_sleep(); |
fe64d517 | 877 | wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE); |
7cf8dcd3 BP |
878 | if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */ |
879 | /* Lengthen the minimum hold time. */ | |
880 | gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time + | |
881 | GL_GLOCK_HOLD_INCR, | |
882 | GL_GLOCK_MAX_HOLD); | |
da755fdb SW |
883 | } |
884 | ||
6802e340 | 885 | static void wait_on_demote(struct gfs2_glock *gl) |
b3b94faa | 886 | { |
6802e340 | 887 | might_sleep(); |
fe64d517 | 888 | wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE); |
b3b94faa DT |
889 | } |
890 | ||
891 | /** | |
6802e340 SW |
892 | * handle_callback - process a demote request |
893 | * @gl: the glock | |
894 | * @state: the state the caller wants us to change to | |
b3b94faa | 895 | * |
6802e340 SW |
896 | * There are only two requests that we are going to see in actual |
897 | * practise: LM_ST_SHARED and LM_ST_UNLOCKED | |
b3b94faa DT |
898 | */ |
899 | ||
6802e340 | 900 | static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
97cc1025 | 901 | unsigned long delay) |
b3b94faa | 902 | { |
6802e340 | 903 | int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; |
b3b94faa | 904 | |
6802e340 SW |
905 | set_bit(bit, &gl->gl_flags); |
906 | if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { | |
907 | gl->gl_demote_state = state; | |
908 | gl->gl_demote_time = jiffies; | |
6802e340 SW |
909 | } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
910 | gl->gl_demote_state != state) { | |
911 | gl->gl_demote_state = LM_ST_UNLOCKED; | |
b3b94faa | 912 | } |
b94a170e BM |
913 | if (gl->gl_ops->go_callback) |
914 | gl->gl_ops->go_callback(gl); | |
63997775 | 915 | trace_gfs2_demote_rq(gl); |
b3b94faa DT |
916 | } |
917 | ||
918 | /** | |
6802e340 | 919 | * gfs2_glock_wait - wait on a glock acquisition |
b3b94faa DT |
920 | * @gh: the glock holder |
921 | * | |
922 | * Returns: 0 on success | |
923 | */ | |
924 | ||
6802e340 | 925 | int gfs2_glock_wait(struct gfs2_holder *gh) |
b3b94faa | 926 | { |
fee852e3 | 927 | wait_on_holder(gh); |
b3b94faa DT |
928 | return gh->gh_error; |
929 | } | |
930 | ||
6802e340 | 931 | void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
7c52b166 | 932 | { |
5e69069c | 933 | struct va_format vaf; |
7c52b166 RP |
934 | va_list args; |
935 | ||
936 | va_start(args, fmt); | |
5e69069c | 937 | |
6802e340 SW |
938 | if (seq) { |
939 | struct gfs2_glock_iter *gi = seq->private; | |
7c52b166 | 940 | vsprintf(gi->string, fmt, args); |
6802e340 SW |
941 | seq_printf(seq, gi->string); |
942 | } else { | |
5e69069c JP |
943 | vaf.fmt = fmt; |
944 | vaf.va = &args; | |
945 | ||
946 | printk(KERN_ERR " %pV", &vaf); | |
6802e340 | 947 | } |
5e69069c | 948 | |
7c52b166 RP |
949 | va_end(args); |
950 | } | |
951 | ||
b3b94faa DT |
952 | /** |
953 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
954 | * @gh: the holder structure to add | |
955 | * | |
6802e340 SW |
956 | * Eventually we should move the recursive locking trap to a |
957 | * debugging option or something like that. This is the fast | |
958 | * path and needs to have the minimum number of distractions. | |
959 | * | |
b3b94faa DT |
960 | */ |
961 | ||
6802e340 | 962 | static inline void add_to_queue(struct gfs2_holder *gh) |
55ba474d HH |
963 | __releases(&gl->gl_spin) |
964 | __acquires(&gl->gl_spin) | |
b3b94faa DT |
965 | { |
966 | struct gfs2_glock *gl = gh->gh_gl; | |
6802e340 SW |
967 | struct gfs2_sbd *sdp = gl->gl_sbd; |
968 | struct list_head *insert_pt = NULL; | |
969 | struct gfs2_holder *gh2; | |
970 | int try_lock = 0; | |
b3b94faa | 971 | |
b1e058da | 972 | BUG_ON(gh->gh_owner_pid == NULL); |
fee852e3 SW |
973 | if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
974 | BUG(); | |
190562bd | 975 | |
6802e340 SW |
976 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
977 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
978 | try_lock = 1; | |
979 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) | |
980 | goto fail; | |
981 | } | |
982 | ||
983 | list_for_each_entry(gh2, &gl->gl_holders, gh_list) { | |
984 | if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && | |
985 | (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) | |
986 | goto trap_recursive; | |
987 | if (try_lock && | |
988 | !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && | |
989 | !may_grant(gl, gh)) { | |
990 | fail: | |
991 | gh->gh_error = GLR_TRYFAILED; | |
992 | gfs2_holder_wake(gh); | |
993 | return; | |
b4c20166 | 994 | } |
6802e340 SW |
995 | if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
996 | continue; | |
997 | if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) | |
998 | insert_pt = &gh2->gh_list; | |
999 | } | |
7b5e3d5f | 1000 | set_bit(GLF_QUEUED, &gl->gl_flags); |
edae38a6 | 1001 | trace_gfs2_glock_queue(gh, 1); |
6802e340 SW |
1002 | if (likely(insert_pt == NULL)) { |
1003 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
1004 | if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) | |
1005 | goto do_cancel; | |
1006 | return; | |
1007 | } | |
1008 | list_add_tail(&gh->gh_list, insert_pt); | |
1009 | do_cancel: | |
1010 | gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); | |
1011 | if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
1012 | spin_unlock(&gl->gl_spin); | |
048bca22 | 1013 | if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
f057f6cd | 1014 | sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
6802e340 | 1015 | spin_lock(&gl->gl_spin); |
b3b94faa | 1016 | } |
6802e340 | 1017 | return; |
b3b94faa | 1018 | |
6802e340 SW |
1019 | trap_recursive: |
1020 | print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); | |
1021 | printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); | |
1022 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1023 | gh2->gh_gl->gl_name.ln_type, gh2->gh_state); | |
1024 | print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); | |
1025 | printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); | |
1026 | printk(KERN_ERR "lock type: %d req lock state : %d\n", | |
1027 | gh->gh_gl->gl_name.ln_type, gh->gh_state); | |
1028 | __dump_glock(NULL, gl); | |
1029 | BUG(); | |
b3b94faa DT |
1030 | } |
1031 | ||
1032 | /** | |
1033 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1034 | * @gh: the holder structure | |
1035 | * | |
1036 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1037 | * | |
1038 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1039 | */ | |
1040 | ||
1041 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1042 | { | |
1043 | struct gfs2_glock *gl = gh->gh_gl; | |
1044 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1045 | int error = 0; | |
1046 | ||
6802e340 | 1047 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
b3b94faa | 1048 | return -EIO; |
b3b94faa | 1049 | |
f42ab085 SW |
1050 | if (test_bit(GLF_LRU, &gl->gl_flags)) |
1051 | gfs2_glock_remove_from_lru(gl); | |
1052 | ||
b3b94faa DT |
1053 | spin_lock(&gl->gl_spin); |
1054 | add_to_queue(gh); | |
0809f6ec SW |
1055 | if ((LM_FLAG_NOEXP & gh->gh_flags) && |
1056 | test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1057 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); | |
6802e340 | 1058 | run_queue(gl, 1); |
b3b94faa DT |
1059 | spin_unlock(&gl->gl_spin); |
1060 | ||
6802e340 SW |
1061 | if (!(gh->gh_flags & GL_ASYNC)) |
1062 | error = gfs2_glock_wait(gh); | |
b3b94faa | 1063 | |
b3b94faa DT |
1064 | return error; |
1065 | } | |
1066 | ||
1067 | /** | |
1068 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1069 | * @gh: the holder | |
1070 | * | |
1071 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1072 | */ | |
1073 | ||
1074 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1075 | { | |
6802e340 | 1076 | return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
b3b94faa DT |
1077 | } |
1078 | ||
1079 | /** | |
1080 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1081 | * @gh: the glock holder | |
1082 | * | |
1083 | */ | |
1084 | ||
1085 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1086 | { | |
1087 | struct gfs2_glock *gl = gh->gh_gl; | |
8fb4b536 | 1088 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
c4f68a13 | 1089 | unsigned delay = 0; |
6802e340 | 1090 | int fast_path = 0; |
b3b94faa | 1091 | |
6802e340 | 1092 | spin_lock(&gl->gl_spin); |
b3b94faa | 1093 | if (gh->gh_flags & GL_NOCACHE) |
97cc1025 | 1094 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
b3b94faa | 1095 | |
b3b94faa | 1096 | list_del_init(&gh->gh_list); |
6802e340 | 1097 | if (find_first_holder(gl) == NULL) { |
3042a2cc | 1098 | if (glops->go_unlock) { |
6802e340 | 1099 | GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); |
3042a2cc | 1100 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1101 | glops->go_unlock(gh); |
3042a2cc | 1102 | spin_lock(&gl->gl_spin); |
6802e340 | 1103 | clear_bit(GLF_LOCK, &gl->gl_flags); |
3042a2cc | 1104 | } |
6802e340 SW |
1105 | if (list_empty(&gl->gl_holders) && |
1106 | !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
1107 | !test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1108 | fast_path = 1; | |
b3b94faa | 1109 | } |
f42ab085 SW |
1110 | if (!test_bit(GLF_LFLUSH, &gl->gl_flags)) |
1111 | __gfs2_glock_schedule_for_reclaim(gl); | |
63997775 | 1112 | trace_gfs2_glock_queue(gh, 0); |
b3b94faa | 1113 | spin_unlock(&gl->gl_spin); |
6802e340 SW |
1114 | if (likely(fast_path)) |
1115 | return; | |
c4f68a13 BM |
1116 | |
1117 | gfs2_glock_hold(gl); | |
1118 | if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && | |
7cf8dcd3 BP |
1119 | !test_bit(GLF_DEMOTE, &gl->gl_flags) && |
1120 | gl->gl_name.ln_type == LM_TYPE_INODE) | |
1121 | delay = gl->gl_hold_time; | |
c4f68a13 BM |
1122 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1123 | gfs2_glock_put(gl); | |
b3b94faa DT |
1124 | } |
1125 | ||
d93cfa98 AD |
1126 | void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
1127 | { | |
1128 | struct gfs2_glock *gl = gh->gh_gl; | |
1129 | gfs2_glock_dq(gh); | |
1130 | wait_on_demote(gl); | |
1131 | } | |
1132 | ||
b3b94faa DT |
1133 | /** |
1134 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1135 | * @gh: the holder structure | |
1136 | * | |
1137 | */ | |
1138 | ||
1139 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1140 | { | |
1141 | gfs2_glock_dq(gh); | |
1142 | gfs2_holder_uninit(gh); | |
1143 | } | |
1144 | ||
1145 | /** | |
1146 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1147 | * @sdp: the filesystem | |
1148 | * @number: the lock number | |
1149 | * @glops: the glock operations for the type of glock | |
1150 | * @state: the state to acquire the glock in | |
25985edc | 1151 | * @flags: modifier flags for the acquisition |
b3b94faa DT |
1152 | * @gh: the struct gfs2_holder |
1153 | * | |
1154 | * Returns: errno | |
1155 | */ | |
1156 | ||
cd915493 | 1157 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
8fb4b536 SW |
1158 | const struct gfs2_glock_operations *glops, |
1159 | unsigned int state, int flags, struct gfs2_holder *gh) | |
b3b94faa DT |
1160 | { |
1161 | struct gfs2_glock *gl; | |
1162 | int error; | |
1163 | ||
1164 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1165 | if (!error) { | |
1166 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1167 | gfs2_glock_put(gl); | |
1168 | } | |
1169 | ||
1170 | return error; | |
1171 | } | |
1172 | ||
1173 | /** | |
1174 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1175 | * @arg_a: the first structure | |
1176 | * @arg_b: the second structure | |
1177 | * | |
1178 | */ | |
1179 | ||
1180 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1181 | { | |
a5e08a9e SW |
1182 | const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
1183 | const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; | |
1184 | const struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1185 | const struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
b3b94faa DT |
1186 | |
1187 | if (a->ln_number > b->ln_number) | |
a5e08a9e SW |
1188 | return 1; |
1189 | if (a->ln_number < b->ln_number) | |
1190 | return -1; | |
1c0f4872 | 1191 | BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
a5e08a9e | 1192 | return 0; |
b3b94faa DT |
1193 | } |
1194 | ||
1195 | /** | |
1196 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1197 | * @num_gh: the number of structures | |
1198 | * @ghs: an array of struct gfs2_holder structures | |
1199 | * | |
1200 | * Returns: 0 on success (all glocks acquired), | |
1201 | * errno on failure (no glocks acquired) | |
1202 | */ | |
1203 | ||
1204 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1205 | struct gfs2_holder **p) | |
1206 | { | |
1207 | unsigned int x; | |
1208 | int error = 0; | |
1209 | ||
1210 | for (x = 0; x < num_gh; x++) | |
1211 | p[x] = &ghs[x]; | |
1212 | ||
1213 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1214 | ||
1215 | for (x = 0; x < num_gh; x++) { | |
1216 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1217 | ||
1218 | error = gfs2_glock_nq(p[x]); | |
1219 | if (error) { | |
1220 | while (x--) | |
1221 | gfs2_glock_dq(p[x]); | |
1222 | break; | |
1223 | } | |
1224 | } | |
1225 | ||
1226 | return error; | |
1227 | } | |
1228 | ||
1229 | /** | |
1230 | * gfs2_glock_nq_m - acquire multiple glocks | |
1231 | * @num_gh: the number of structures | |
1232 | * @ghs: an array of struct gfs2_holder structures | |
1233 | * | |
b3b94faa DT |
1234 | * |
1235 | * Returns: 0 on success (all glocks acquired), | |
1236 | * errno on failure (no glocks acquired) | |
1237 | */ | |
1238 | ||
1239 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1240 | { | |
eaf5bd3c SW |
1241 | struct gfs2_holder *tmp[4]; |
1242 | struct gfs2_holder **pph = tmp; | |
b3b94faa DT |
1243 | int error = 0; |
1244 | ||
eaf5bd3c SW |
1245 | switch(num_gh) { |
1246 | case 0: | |
b3b94faa | 1247 | return 0; |
eaf5bd3c | 1248 | case 1: |
b3b94faa DT |
1249 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); |
1250 | return gfs2_glock_nq(ghs); | |
eaf5bd3c SW |
1251 | default: |
1252 | if (num_gh <= 4) | |
b3b94faa | 1253 | break; |
eaf5bd3c SW |
1254 | pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS); |
1255 | if (!pph) | |
1256 | return -ENOMEM; | |
b3b94faa DT |
1257 | } |
1258 | ||
eaf5bd3c | 1259 | error = nq_m_sync(num_gh, ghs, pph); |
b3b94faa | 1260 | |
eaf5bd3c SW |
1261 | if (pph != tmp) |
1262 | kfree(pph); | |
b3b94faa DT |
1263 | |
1264 | return error; | |
1265 | } | |
1266 | ||
1267 | /** | |
1268 | * gfs2_glock_dq_m - release multiple glocks | |
1269 | * @num_gh: the number of structures | |
1270 | * @ghs: an array of struct gfs2_holder structures | |
1271 | * | |
1272 | */ | |
1273 | ||
1274 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1275 | { | |
fa1bbdea BP |
1276 | while (num_gh--) |
1277 | gfs2_glock_dq(&ghs[num_gh]); | |
b3b94faa DT |
1278 | } |
1279 | ||
1280 | /** | |
1281 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1282 | * @num_gh: the number of structures | |
1283 | * @ghs: an array of struct gfs2_holder structures | |
1284 | * | |
1285 | */ | |
1286 | ||
1287 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1288 | { | |
fa1bbdea BP |
1289 | while (num_gh--) |
1290 | gfs2_glock_dq_uninit(&ghs[num_gh]); | |
b3b94faa DT |
1291 | } |
1292 | ||
f057f6cd | 1293 | void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
da755fdb | 1294 | { |
c4f68a13 BM |
1295 | unsigned long delay = 0; |
1296 | unsigned long holdtime; | |
1297 | unsigned long now = jiffies; | |
b3b94faa | 1298 | |
f057f6cd | 1299 | gfs2_glock_hold(gl); |
7cf8dcd3 BP |
1300 | holdtime = gl->gl_tchange + gl->gl_hold_time; |
1301 | if (test_bit(GLF_QUEUED, &gl->gl_flags) && | |
1302 | gl->gl_name.ln_type == LM_TYPE_INODE) { | |
7b5e3d5f SW |
1303 | if (time_before(now, holdtime)) |
1304 | delay = holdtime - now; | |
1305 | if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) | |
7cf8dcd3 | 1306 | delay = gl->gl_hold_time; |
7b5e3d5f | 1307 | } |
b3b94faa | 1308 | |
6802e340 | 1309 | spin_lock(&gl->gl_spin); |
97cc1025 | 1310 | handle_callback(gl, state, delay); |
6802e340 | 1311 | spin_unlock(&gl->gl_spin); |
c4f68a13 BM |
1312 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) |
1313 | gfs2_glock_put(gl); | |
b3b94faa DT |
1314 | } |
1315 | ||
0809f6ec SW |
1316 | /** |
1317 | * gfs2_should_freeze - Figure out if glock should be frozen | |
1318 | * @gl: The glock in question | |
1319 | * | |
1320 | * Glocks are not frozen if (a) the result of the dlm operation is | |
1321 | * an error, (b) the locking operation was an unlock operation or | |
1322 | * (c) if there is a "noexp" flagged request anywhere in the queue | |
1323 | * | |
1324 | * Returns: 1 if freezing should occur, 0 otherwise | |
1325 | */ | |
1326 | ||
1327 | static int gfs2_should_freeze(const struct gfs2_glock *gl) | |
1328 | { | |
1329 | const struct gfs2_holder *gh; | |
1330 | ||
1331 | if (gl->gl_reply & ~LM_OUT_ST_MASK) | |
1332 | return 0; | |
1333 | if (gl->gl_target == LM_ST_UNLOCKED) | |
1334 | return 0; | |
1335 | ||
1336 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
1337 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1338 | continue; | |
1339 | if (LM_FLAG_NOEXP & gh->gh_flags) | |
1340 | return 0; | |
1341 | } | |
1342 | ||
1343 | return 1; | |
1344 | } | |
1345 | ||
b3b94faa | 1346 | /** |
f057f6cd SW |
1347 | * gfs2_glock_complete - Callback used by locking |
1348 | * @gl: Pointer to the glock | |
1349 | * @ret: The return value from the dlm | |
b3b94faa | 1350 | * |
47a25380 SW |
1351 | * The gl_reply field is under the gl_spin lock so that it is ok |
1352 | * to use a bitfield shared with other glock state fields. | |
b3b94faa DT |
1353 | */ |
1354 | ||
f057f6cd | 1355 | void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
b3b94faa | 1356 | { |
f057f6cd | 1357 | struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; |
0809f6ec | 1358 | |
47a25380 | 1359 | spin_lock(&gl->gl_spin); |
f057f6cd | 1360 | gl->gl_reply = ret; |
0809f6ec | 1361 | |
e0c2a9aa | 1362 | if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) { |
0809f6ec | 1363 | if (gfs2_should_freeze(gl)) { |
f057f6cd | 1364 | set_bit(GLF_FROZEN, &gl->gl_flags); |
0809f6ec | 1365 | spin_unlock(&gl->gl_spin); |
b3b94faa | 1366 | return; |
0809f6ec | 1367 | } |
b3b94faa | 1368 | } |
47a25380 SW |
1369 | |
1370 | spin_unlock(&gl->gl_spin); | |
f057f6cd | 1371 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
47a25380 | 1372 | smp_wmb(); |
f057f6cd SW |
1373 | gfs2_glock_hold(gl); |
1374 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1375 | gfs2_glock_put(gl); | |
b3b94faa DT |
1376 | } |
1377 | ||
b3b94faa | 1378 | |
1495f230 YH |
1379 | static int gfs2_shrink_glock_memory(struct shrinker *shrink, |
1380 | struct shrink_control *sc) | |
b3b94faa DT |
1381 | { |
1382 | struct gfs2_glock *gl; | |
97cc1025 SW |
1383 | int may_demote; |
1384 | int nr_skipped = 0; | |
1495f230 YH |
1385 | int nr = sc->nr_to_scan; |
1386 | gfp_t gfp_mask = sc->gfp_mask; | |
97cc1025 | 1387 | LIST_HEAD(skipped); |
b3b94faa | 1388 | |
97cc1025 SW |
1389 | if (nr == 0) |
1390 | goto out; | |
b3b94faa | 1391 | |
97cc1025 SW |
1392 | if (!(gfp_mask & __GFP_FS)) |
1393 | return -1; | |
b3b94faa | 1394 | |
97cc1025 SW |
1395 | spin_lock(&lru_lock); |
1396 | while(nr && !list_empty(&lru_list)) { | |
1397 | gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru); | |
1398 | list_del_init(&gl->gl_lru); | |
627c10b7 | 1399 | clear_bit(GLF_LRU, &gl->gl_flags); |
97cc1025 SW |
1400 | atomic_dec(&lru_count); |
1401 | ||
1402 | /* Test for being demotable */ | |
1403 | if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { | |
1404 | gfs2_glock_hold(gl); | |
97cc1025 SW |
1405 | spin_unlock(&lru_lock); |
1406 | spin_lock(&gl->gl_spin); | |
1407 | may_demote = demote_ok(gl); | |
97cc1025 SW |
1408 | if (may_demote) { |
1409 | handle_callback(gl, LM_ST_UNLOCKED, 0); | |
1410 | nr--; | |
97cc1025 | 1411 | } |
7e71c55e SW |
1412 | clear_bit(GLF_LOCK, &gl->gl_flags); |
1413 | smp_mb__after_clear_bit(); | |
2163b1e6 | 1414 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) |
b94a170e BM |
1415 | gfs2_glock_put_nolock(gl); |
1416 | spin_unlock(&gl->gl_spin); | |
97cc1025 | 1417 | spin_lock(&lru_lock); |
2163b1e6 | 1418 | continue; |
97cc1025 | 1419 | } |
2163b1e6 SW |
1420 | nr_skipped++; |
1421 | list_add(&gl->gl_lru, &skipped); | |
627c10b7 | 1422 | set_bit(GLF_LRU, &gl->gl_flags); |
b3b94faa | 1423 | } |
97cc1025 SW |
1424 | list_splice(&skipped, &lru_list); |
1425 | atomic_add(nr_skipped, &lru_count); | |
1426 | spin_unlock(&lru_lock); | |
1427 | out: | |
1428 | return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure; | |
b3b94faa DT |
1429 | } |
1430 | ||
97cc1025 SW |
1431 | static struct shrinker glock_shrinker = { |
1432 | .shrink = gfs2_shrink_glock_memory, | |
1433 | .seeks = DEFAULT_SEEKS, | |
1434 | }; | |
1435 | ||
b3b94faa DT |
1436 | /** |
1437 | * examine_bucket - Call a function for glock in a hash bucket | |
1438 | * @examiner: the function | |
1439 | * @sdp: the filesystem | |
1440 | * @bucket: the bucket | |
1441 | * | |
b3b94faa DT |
1442 | */ |
1443 | ||
bc015cb8 | 1444 | static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp, |
37b2fa6a | 1445 | unsigned int hash) |
b3b94faa | 1446 | { |
bc015cb8 SW |
1447 | struct gfs2_glock *gl; |
1448 | struct hlist_bl_head *head = &gl_hash_table[hash]; | |
1449 | struct hlist_bl_node *pos; | |
b3b94faa | 1450 | |
bc015cb8 SW |
1451 | rcu_read_lock(); |
1452 | hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) { | |
1453 | if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref)) | |
24264434 | 1454 | examiner(gl); |
b3b94faa | 1455 | } |
bc015cb8 | 1456 | rcu_read_unlock(); |
8fbbfd21 | 1457 | cond_resched(); |
bc015cb8 SW |
1458 | } |
1459 | ||
1460 | static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) | |
1461 | { | |
1462 | unsigned x; | |
1463 | ||
1464 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
1465 | examine_bucket(examiner, sdp, x); | |
b3b94faa DT |
1466 | } |
1467 | ||
f057f6cd SW |
1468 | |
1469 | /** | |
1470 | * thaw_glock - thaw out a glock which has an unprocessed reply waiting | |
1471 | * @gl: The glock to thaw | |
1472 | * | |
1473 | * N.B. When we freeze a glock, we leave a ref to the glock outstanding, | |
1474 | * so this has to result in the ref count being dropped by one. | |
1475 | */ | |
1476 | ||
1477 | static void thaw_glock(struct gfs2_glock *gl) | |
1478 | { | |
1479 | if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) | |
1480 | return; | |
f057f6cd SW |
1481 | set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
1482 | gfs2_glock_hold(gl); | |
1483 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1484 | gfs2_glock_put(gl); | |
f057f6cd SW |
1485 | } |
1486 | ||
b3b94faa DT |
1487 | /** |
1488 | * clear_glock - look at a glock and see if we can free it from glock cache | |
1489 | * @gl: the glock to look at | |
1490 | * | |
1491 | */ | |
1492 | ||
1493 | static void clear_glock(struct gfs2_glock *gl) | |
1494 | { | |
f42ab085 | 1495 | gfs2_glock_remove_from_lru(gl); |
b3b94faa | 1496 | |
6802e340 | 1497 | spin_lock(&gl->gl_spin); |
c741c455 | 1498 | if (gl->gl_state != LM_ST_UNLOCKED) |
97cc1025 | 1499 | handle_callback(gl, LM_ST_UNLOCKED, 0); |
6802e340 SW |
1500 | spin_unlock(&gl->gl_spin); |
1501 | gfs2_glock_hold(gl); | |
1502 | if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) | |
1503 | gfs2_glock_put(gl); | |
b3b94faa DT |
1504 | } |
1505 | ||
f057f6cd SW |
1506 | /** |
1507 | * gfs2_glock_thaw - Thaw any frozen glocks | |
1508 | * @sdp: The super block | |
1509 | * | |
1510 | */ | |
1511 | ||
1512 | void gfs2_glock_thaw(struct gfs2_sbd *sdp) | |
1513 | { | |
bc015cb8 SW |
1514 | glock_hash_walk(thaw_glock, sdp); |
1515 | } | |
f057f6cd | 1516 | |
bc015cb8 SW |
1517 | static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) |
1518 | { | |
1519 | int ret; | |
1520 | spin_lock(&gl->gl_spin); | |
1521 | ret = __dump_glock(seq, gl); | |
1522 | spin_unlock(&gl->gl_spin); | |
1523 | return ret; | |
1524 | } | |
1525 | ||
1526 | static void dump_glock_func(struct gfs2_glock *gl) | |
1527 | { | |
1528 | dump_glock(NULL, gl); | |
f057f6cd SW |
1529 | } |
1530 | ||
b3b94faa DT |
1531 | /** |
1532 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
1533 | * @sdp: the filesystem | |
1534 | * @wait: wait until it's all gone | |
1535 | * | |
1bdad606 | 1536 | * Called when unmounting the filesystem. |
b3b94faa DT |
1537 | */ |
1538 | ||
fefc03bf | 1539 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
b3b94faa | 1540 | { |
bc015cb8 | 1541 | glock_hash_walk(clear_glock, sdp); |
8f05228e SW |
1542 | flush_workqueue(glock_workqueue); |
1543 | wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0); | |
bc015cb8 | 1544 | glock_hash_walk(dump_glock_func, sdp); |
b3b94faa DT |
1545 | } |
1546 | ||
813e0c46 SW |
1547 | void gfs2_glock_finish_truncate(struct gfs2_inode *ip) |
1548 | { | |
1549 | struct gfs2_glock *gl = ip->i_gl; | |
1550 | int ret; | |
1551 | ||
1552 | ret = gfs2_truncatei_resume(ip); | |
1553 | gfs2_assert_withdraw(gl->gl_sbd, ret == 0); | |
1554 | ||
1555 | spin_lock(&gl->gl_spin); | |
1556 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1557 | run_queue(gl, 1); | |
1558 | spin_unlock(&gl->gl_spin); | |
1559 | } | |
1560 | ||
6802e340 | 1561 | static const char *state2str(unsigned state) |
04b933f2 | 1562 | { |
6802e340 SW |
1563 | switch(state) { |
1564 | case LM_ST_UNLOCKED: | |
1565 | return "UN"; | |
1566 | case LM_ST_SHARED: | |
1567 | return "SH"; | |
1568 | case LM_ST_DEFERRED: | |
1569 | return "DF"; | |
1570 | case LM_ST_EXCLUSIVE: | |
1571 | return "EX"; | |
1572 | } | |
1573 | return "??"; | |
1574 | } | |
1575 | ||
1576 | static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) | |
1577 | { | |
1578 | char *p = buf; | |
1579 | if (flags & LM_FLAG_TRY) | |
1580 | *p++ = 't'; | |
1581 | if (flags & LM_FLAG_TRY_1CB) | |
1582 | *p++ = 'T'; | |
1583 | if (flags & LM_FLAG_NOEXP) | |
1584 | *p++ = 'e'; | |
1585 | if (flags & LM_FLAG_ANY) | |
f057f6cd | 1586 | *p++ = 'A'; |
6802e340 SW |
1587 | if (flags & LM_FLAG_PRIORITY) |
1588 | *p++ = 'p'; | |
1589 | if (flags & GL_ASYNC) | |
1590 | *p++ = 'a'; | |
1591 | if (flags & GL_EXACT) | |
1592 | *p++ = 'E'; | |
6802e340 SW |
1593 | if (flags & GL_NOCACHE) |
1594 | *p++ = 'c'; | |
1595 | if (test_bit(HIF_HOLDER, &iflags)) | |
1596 | *p++ = 'H'; | |
1597 | if (test_bit(HIF_WAIT, &iflags)) | |
1598 | *p++ = 'W'; | |
1599 | if (test_bit(HIF_FIRST, &iflags)) | |
1600 | *p++ = 'F'; | |
1601 | *p = 0; | |
1602 | return buf; | |
04b933f2 RP |
1603 | } |
1604 | ||
b3b94faa DT |
1605 | /** |
1606 | * dump_holder - print information about a glock holder | |
6802e340 | 1607 | * @seq: the seq_file struct |
b3b94faa DT |
1608 | * @gh: the glock holder |
1609 | * | |
1610 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1611 | */ | |
1612 | ||
6802e340 | 1613 | static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) |
b3b94faa | 1614 | { |
6802e340 | 1615 | struct task_struct *gh_owner = NULL; |
6802e340 | 1616 | char flags_buf[32]; |
b3b94faa | 1617 | |
6802e340 | 1618 | if (gh->gh_owner_pid) |
b1e058da | 1619 | gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
cc18152e JP |
1620 | gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n", |
1621 | state2str(gh->gh_state), | |
1622 | hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), | |
1623 | gh->gh_error, | |
1624 | gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, | |
1625 | gh_owner ? gh_owner->comm : "(ended)", | |
1626 | (void *)gh->gh_ip); | |
7c52b166 | 1627 | return 0; |
b3b94faa DT |
1628 | } |
1629 | ||
627c10b7 | 1630 | static const char *gflags2str(char *buf, const struct gfs2_glock *gl) |
6802e340 | 1631 | { |
627c10b7 | 1632 | const unsigned long *gflags = &gl->gl_flags; |
6802e340 | 1633 | char *p = buf; |
627c10b7 | 1634 | |
6802e340 SW |
1635 | if (test_bit(GLF_LOCK, gflags)) |
1636 | *p++ = 'l'; | |
6802e340 SW |
1637 | if (test_bit(GLF_DEMOTE, gflags)) |
1638 | *p++ = 'D'; | |
1639 | if (test_bit(GLF_PENDING_DEMOTE, gflags)) | |
1640 | *p++ = 'd'; | |
1641 | if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) | |
1642 | *p++ = 'p'; | |
1643 | if (test_bit(GLF_DIRTY, gflags)) | |
1644 | *p++ = 'y'; | |
1645 | if (test_bit(GLF_LFLUSH, gflags)) | |
1646 | *p++ = 'f'; | |
1647 | if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) | |
1648 | *p++ = 'i'; | |
1649 | if (test_bit(GLF_REPLY_PENDING, gflags)) | |
1650 | *p++ = 'r'; | |
f057f6cd | 1651 | if (test_bit(GLF_INITIAL, gflags)) |
d8348de0 | 1652 | *p++ = 'I'; |
f057f6cd SW |
1653 | if (test_bit(GLF_FROZEN, gflags)) |
1654 | *p++ = 'F'; | |
7b5e3d5f SW |
1655 | if (test_bit(GLF_QUEUED, gflags)) |
1656 | *p++ = 'q'; | |
627c10b7 SW |
1657 | if (test_bit(GLF_LRU, gflags)) |
1658 | *p++ = 'L'; | |
1659 | if (gl->gl_object) | |
1660 | *p++ = 'o'; | |
6802e340 SW |
1661 | *p = 0; |
1662 | return buf; | |
b3b94faa DT |
1663 | } |
1664 | ||
1665 | /** | |
6802e340 SW |
1666 | * __dump_glock - print information about a glock |
1667 | * @seq: The seq_file struct | |
b3b94faa | 1668 | * @gl: the glock |
6802e340 SW |
1669 | * |
1670 | * The file format is as follows: | |
1671 | * One line per object, capital letters are used to indicate objects | |
1672 | * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, | |
1673 | * other objects are indented by a single space and follow the glock to | |
1674 | * which they are related. Fields are indicated by lower case letters | |
1675 | * followed by a colon and the field value, except for strings which are in | |
1676 | * [] so that its possible to see if they are composed of spaces for | |
1677 | * example. The field's are n = number (id of the object), f = flags, | |
1678 | * t = type, s = state, r = refcount, e = error, p = pid. | |
b3b94faa DT |
1679 | * |
1680 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
1681 | */ | |
1682 | ||
6802e340 | 1683 | static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) |
b3b94faa | 1684 | { |
6802e340 SW |
1685 | const struct gfs2_glock_operations *glops = gl->gl_ops; |
1686 | unsigned long long dtime; | |
1687 | const struct gfs2_holder *gh; | |
1688 | char gflags_buf[32]; | |
1689 | int error = 0; | |
b3b94faa | 1690 | |
6802e340 SW |
1691 | dtime = jiffies - gl->gl_demote_time; |
1692 | dtime *= 1000000/HZ; /* demote time in uSec */ | |
1693 | if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) | |
1694 | dtime = 0; | |
7cf8dcd3 | 1695 | gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d m:%ld\n", |
6802e340 SW |
1696 | state2str(gl->gl_state), |
1697 | gl->gl_name.ln_type, | |
1698 | (unsigned long long)gl->gl_name.ln_number, | |
627c10b7 | 1699 | gflags2str(gflags_buf, gl), |
6802e340 SW |
1700 | state2str(gl->gl_target), |
1701 | state2str(gl->gl_demote_state), dtime, | |
6802e340 | 1702 | atomic_read(&gl->gl_ail_count), |
f42ab085 | 1703 | atomic_read(&gl->gl_revokes), |
7cf8dcd3 | 1704 | atomic_read(&gl->gl_ref), gl->gl_hold_time); |
b3b94faa | 1705 | |
b3b94faa | 1706 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
6802e340 | 1707 | error = dump_holder(seq, gh); |
b3b94faa DT |
1708 | if (error) |
1709 | goto out; | |
1710 | } | |
6802e340 SW |
1711 | if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
1712 | error = glops->go_dump(seq, gl); | |
a91ea69f | 1713 | out: |
b3b94faa DT |
1714 | return error; |
1715 | } | |
1716 | ||
6802e340 | 1717 | |
b3b94faa | 1718 | |
8fbbfd21 | 1719 | |
85d1da67 SW |
1720 | int __init gfs2_glock_init(void) |
1721 | { | |
1722 | unsigned i; | |
1723 | for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { | |
bc015cb8 | 1724 | INIT_HLIST_BL_HEAD(&gl_hash_table[i]); |
087efdd3 | 1725 | } |
8fbbfd21 | 1726 | |
d2115778 | 1727 | glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | |
58a69cb4 | 1728 | WQ_HIGHPRI | WQ_FREEZABLE, 0); |
97cc1025 | 1729 | if (IS_ERR(glock_workqueue)) |
c4f68a13 | 1730 | return PTR_ERR(glock_workqueue); |
d2115778 | 1731 | gfs2_delete_workqueue = alloc_workqueue("delete_workqueue", |
58a69cb4 | 1732 | WQ_MEM_RECLAIM | WQ_FREEZABLE, |
d2115778 | 1733 | 0); |
b94a170e BM |
1734 | if (IS_ERR(gfs2_delete_workqueue)) { |
1735 | destroy_workqueue(glock_workqueue); | |
1736 | return PTR_ERR(gfs2_delete_workqueue); | |
1737 | } | |
97cc1025 SW |
1738 | |
1739 | register_shrinker(&glock_shrinker); | |
c4f68a13 | 1740 | |
85d1da67 SW |
1741 | return 0; |
1742 | } | |
1743 | ||
8fbbfd21 SW |
1744 | void gfs2_glock_exit(void) |
1745 | { | |
97cc1025 | 1746 | unregister_shrinker(&glock_shrinker); |
c4f68a13 | 1747 | destroy_workqueue(glock_workqueue); |
b94a170e | 1748 | destroy_workqueue(gfs2_delete_workqueue); |
8fbbfd21 SW |
1749 | } |
1750 | ||
bc015cb8 SW |
1751 | static inline struct gfs2_glock *glock_hash_chain(unsigned hash) |
1752 | { | |
1753 | return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]), | |
1754 | struct gfs2_glock, gl_list); | |
1755 | } | |
1756 | ||
1757 | static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl) | |
1758 | { | |
7e32d026 | 1759 | return hlist_bl_entry(rcu_dereference(gl->gl_list.next), |
bc015cb8 SW |
1760 | struct gfs2_glock, gl_list); |
1761 | } | |
1762 | ||
6802e340 | 1763 | static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) |
7c52b166 | 1764 | { |
7b08fc62 SW |
1765 | struct gfs2_glock *gl; |
1766 | ||
bc015cb8 SW |
1767 | do { |
1768 | gl = gi->gl; | |
1769 | if (gl) { | |
1770 | gi->gl = glock_hash_next(gl); | |
1771 | } else { | |
1772 | gi->gl = glock_hash_chain(gi->hash); | |
1773 | } | |
1774 | while (gi->gl == NULL) { | |
1775 | gi->hash++; | |
1776 | if (gi->hash >= GFS2_GL_HASH_SIZE) { | |
1777 | rcu_read_unlock(); | |
1778 | return 1; | |
1779 | } | |
1780 | gi->gl = glock_hash_chain(gi->hash); | |
1781 | } | |
1782 | /* Skip entries for other sb and dead entries */ | |
1783 | } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0); | |
a947e033 | 1784 | |
7c52b166 RP |
1785 | return 0; |
1786 | } | |
1787 | ||
6802e340 | 1788 | static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
7c52b166 | 1789 | { |
6802e340 | 1790 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1791 | loff_t n = *pos; |
1792 | ||
6802e340 | 1793 | gi->hash = 0; |
bc015cb8 | 1794 | rcu_read_lock(); |
7c52b166 | 1795 | |
6802e340 | 1796 | do { |
bc015cb8 | 1797 | if (gfs2_glock_iter_next(gi)) |
7c52b166 | 1798 | return NULL; |
6802e340 | 1799 | } while (n--); |
7c52b166 | 1800 | |
6802e340 | 1801 | return gi->gl; |
7c52b166 RP |
1802 | } |
1803 | ||
6802e340 | 1804 | static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
7c52b166 RP |
1805 | loff_t *pos) |
1806 | { | |
6802e340 | 1807 | struct gfs2_glock_iter *gi = seq->private; |
7c52b166 RP |
1808 | |
1809 | (*pos)++; | |
1810 | ||
bc015cb8 | 1811 | if (gfs2_glock_iter_next(gi)) |
7c52b166 | 1812 | return NULL; |
7c52b166 | 1813 | |
6802e340 | 1814 | return gi->gl; |
7c52b166 RP |
1815 | } |
1816 | ||
6802e340 | 1817 | static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1818 | { |
6802e340 | 1819 | struct gfs2_glock_iter *gi = seq->private; |
bc015cb8 SW |
1820 | |
1821 | if (gi->gl) | |
1822 | rcu_read_unlock(); | |
1823 | gi->gl = NULL; | |
7c52b166 RP |
1824 | } |
1825 | ||
6802e340 | 1826 | static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
7c52b166 | 1827 | { |
6802e340 | 1828 | return dump_glock(seq, iter_ptr); |
7c52b166 RP |
1829 | } |
1830 | ||
4ef29002 | 1831 | static const struct seq_operations gfs2_glock_seq_ops = { |
7c52b166 RP |
1832 | .start = gfs2_glock_seq_start, |
1833 | .next = gfs2_glock_seq_next, | |
1834 | .stop = gfs2_glock_seq_stop, | |
1835 | .show = gfs2_glock_seq_show, | |
1836 | }; | |
1837 | ||
1838 | static int gfs2_debugfs_open(struct inode *inode, struct file *file) | |
1839 | { | |
6802e340 SW |
1840 | int ret = seq_open_private(file, &gfs2_glock_seq_ops, |
1841 | sizeof(struct gfs2_glock_iter)); | |
1842 | if (ret == 0) { | |
1843 | struct seq_file *seq = file->private_data; | |
1844 | struct gfs2_glock_iter *gi = seq->private; | |
1845 | gi->sdp = inode->i_private; | |
1846 | } | |
1847 | return ret; | |
7c52b166 RP |
1848 | } |
1849 | ||
1850 | static const struct file_operations gfs2_debug_fops = { | |
1851 | .owner = THIS_MODULE, | |
1852 | .open = gfs2_debugfs_open, | |
1853 | .read = seq_read, | |
1854 | .llseek = seq_lseek, | |
6802e340 | 1855 | .release = seq_release_private, |
7c52b166 RP |
1856 | }; |
1857 | ||
1858 | int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) | |
1859 | { | |
5f882096 RP |
1860 | sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
1861 | if (!sdp->debugfs_dir) | |
1862 | return -ENOMEM; | |
1863 | sdp->debugfs_dentry_glocks = debugfs_create_file("glocks", | |
1864 | S_IFREG | S_IRUGO, | |
1865 | sdp->debugfs_dir, sdp, | |
1866 | &gfs2_debug_fops); | |
1867 | if (!sdp->debugfs_dentry_glocks) | |
7c52b166 RP |
1868 | return -ENOMEM; |
1869 | ||
1870 | return 0; | |
1871 | } | |
1872 | ||
1873 | void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) | |
1874 | { | |
5f882096 RP |
1875 | if (sdp && sdp->debugfs_dir) { |
1876 | if (sdp->debugfs_dentry_glocks) { | |
1877 | debugfs_remove(sdp->debugfs_dentry_glocks); | |
1878 | sdp->debugfs_dentry_glocks = NULL; | |
1879 | } | |
1880 | debugfs_remove(sdp->debugfs_dir); | |
1881 | sdp->debugfs_dir = NULL; | |
1882 | } | |
7c52b166 RP |
1883 | } |
1884 | ||
1885 | int gfs2_register_debugfs(void) | |
1886 | { | |
1887 | gfs2_root = debugfs_create_dir("gfs2", NULL); | |
1888 | return gfs2_root ? 0 : -ENOMEM; | |
1889 | } | |
1890 | ||
1891 | void gfs2_unregister_debugfs(void) | |
1892 | { | |
1893 | debugfs_remove(gfs2_root); | |
5f882096 | 1894 | gfs2_root = NULL; |
7c52b166 | 1895 | } |