1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * dlmglue.c |
4 | * |
5 | * Code which implements an OCFS2 specific interface to our DLM. |
6 | * |
7 | * Copyright (C) 2003, 2004 Oracle. All rights reserved. |
8 | */ |
9 | |
10 | #include <linux/types.h> |
11 | #include <linux/slab.h> |
12 | #include <linux/highmem.h> |
13 | #include <linux/mm.h> |
14 | #include <linux/kthread.h> |
15 | #include <linux/pagemap.h> |
16 | #include <linux/debugfs.h> |
17 | #include <linux/seq_file.h> |
18 | #include <linux/time.h> |
19 | #include <linux/delay.h> |
20 | #include <linux/quotaops.h> |
21 | #include <linux/sched/signal.h> |
22 | |
23 | #define MLOG_MASK_PREFIX ML_DLM_GLUE |
24 | #include <cluster/masklog.h> |
25 | |
26 | #include "ocfs2.h" |
27 | #include "ocfs2_lockingver.h" |
28 | |
29 | #include "alloc.h" |
30 | #include "dcache.h" |
31 | #include "dlmglue.h" |
32 | #include "extent_map.h" |
33 | #include "file.h" |
34 | #include "heartbeat.h" |
35 | #include "inode.h" |
36 | #include "journal.h" |
37 | #include "stackglue.h" |
38 | #include "slot_map.h" |
39 | #include "super.h" |
40 | #include "uptodate.h" |
41 | #include "quota.h" |
42 | #include "refcounttree.h" |
43 | #include "acl.h" |
44 | |
45 | #include "buffer_head_io.h" |
46 | |
47 | struct ocfs2_mask_waiter { |
48 | struct list_head mw_item; |
49 | int mw_status; |
50 | struct completion mw_complete; |
51 | unsigned long mw_mask; |
52 | unsigned long mw_goal; |
53 | #ifdef CONFIG_OCFS2_FS_STATS |
54 | ktime_t mw_lock_start; |
55 | #endif |
56 | }; |
57 | |
58 | static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres); |
59 | static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres); |
60 | static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres); |
61 | static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres); |
62 | |
63 | /* |
64 | * Return value from ->downconvert_worker functions. |
65 | * |
66 | * These control the precise actions of ocfs2_unblock_lock() |
67 | * and ocfs2_process_blocked_lock() |
68 | * |
69 | */ |
70 | enum ocfs2_unblock_action { |
71 | UNBLOCK_CONTINUE = 0, /* Continue downconvert */ |
72 | UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire |
73 | * ->post_unlock callback */ |
74 | UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire |
75 | * ->post_unlock() callback. */ |
76 | }; |
77 | |
78 | struct ocfs2_unblock_ctl { |
79 | int requeue; |
80 | enum ocfs2_unblock_action unblock_action; |
81 | }; |
82 | |
83 | /* Lockdep class keys */ |
84 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
85 | static struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES]; |
86 | #endif |
87 | |
88 | static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, |
89 | int new_level); |
90 | static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres); |
91 | |
92 | static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, |
93 | int blocking); |
94 | |
95 | static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, |
96 | int blocking); |
97 | |
98 | static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, |
99 | struct ocfs2_lock_res *lockres); |
100 | |
101 | static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres); |
102 | |
103 | static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres, |
104 | int new_level); |
105 | static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres, |
106 | int blocking); |
107 | |
108 | #define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres) |
109 | |
110 | /* This aids in debugging situations where a bad LVB might be involved. */ |
111 | static void ocfs2_dump_meta_lvb_info(u64 level, |
112 | const char *function, |
113 | unsigned int line, |
114 | struct ocfs2_lock_res *lockres) |
115 | { |
116 | struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
117 | |
118 | mlog(level, "LVB information for %s (called from %s:%u):\n" , |
119 | lockres->l_name, function, line); |
120 | mlog(level, "version: %u, clusters: %u, generation: 0x%x\n" , |
121 | lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters), |
122 | be32_to_cpu(lvb->lvb_igeneration)); |
123 | mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n" , |
124 | (unsigned long long)be64_to_cpu(lvb->lvb_isize), |
125 | be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid), |
126 | be16_to_cpu(lvb->lvb_imode)); |
127 | mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, " |
128 | "mtime_packed 0x%llx iattr 0x%x\n" , be16_to_cpu(lvb->lvb_inlink), |
129 | (long long)be64_to_cpu(lvb->lvb_iatime_packed), |
130 | (long long)be64_to_cpu(lvb->lvb_ictime_packed), |
131 | (long long)be64_to_cpu(lvb->lvb_imtime_packed), |
132 | be32_to_cpu(lvb->lvb_iattr)); |
133 | } |
134 | |
135 | |
136 | /* |
137 | * OCFS2 Lock Resource Operations |
138 | * |
139 | * These fine tune the behavior of the generic dlmglue locking infrastructure. |
140 | * |
141 | * The most basic of lock types can point ->l_priv to their respective |
142 | * struct ocfs2_super and allow the default actions to manage things. |
143 | * |
144 | * Right now, each lock type also needs to implement an init function, |
145 | * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres() |
146 | * should be called when the lock is no longer needed (i.e., object |
147 | * destruction time). |
148 | */ |
149 | struct ocfs2_lock_res_ops { |
150 | /* |
151 | * Translate an ocfs2_lock_res * into an ocfs2_super *. Define |
152 | * this callback if ->l_priv is not an ocfs2_super pointer |
153 | */ |
154 | struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *); |
155 | |
156 | /* |
157 | * Optionally called in the downconvert thread after a |
158 | * successful downconvert. The lockres will not be referenced |
159 | * after this callback is called, so it is safe to free |
160 | * memory, etc. |
161 | * |
162 | * The exact semantics of when this is called are controlled |
163 | * by ->downconvert_worker() |
164 | */ |
165 | void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *); |
166 | |
167 | /* |
168 | * Allow a lock type to add checks to determine whether it is |
169 | * safe to downconvert a lock. Return 0 to re-queue the |
170 | * downconvert at a later time, nonzero to continue. |
171 | * |
172 | * For most locks, the default checks that there are no |
173 | * incompatible holders are sufficient. |
174 | * |
175 | * Called with the lockres spinlock held. |
176 | */ |
177 | int (*check_downconvert)(struct ocfs2_lock_res *, int); |
178 | |
179 | /* |
180 | * Allows a lock type to populate the lock value block. This |
181 | * is called on downconvert, and when we drop a lock. |
182 | * |
183 | * Locks that want to use this should set LOCK_TYPE_USES_LVB |
184 | * in the flags field. |
185 | * |
186 | * Called with the lockres spinlock held. |
187 | */ |
188 | void (*set_lvb)(struct ocfs2_lock_res *); |
189 | |
190 | /* |
191 | * Called from the downconvert thread when it is determined |
192 | * that a lock will be downconverted. This is called without |
193 | * any locks held so the function can do work that might |
194 | * schedule (syncing out data, etc). |
195 | * |
196 | * This should return any one of the ocfs2_unblock_action |
197 | * values, depending on what it wants the thread to do. |
198 | */ |
199 | int (*downconvert_worker)(struct ocfs2_lock_res *, int); |
200 | |
201 | /* |
202 | * LOCK_TYPE_* flags which describe the specific requirements |
203 | * of a lock type. Descriptions of each individual flag follow. |
204 | */ |
205 | int flags; |
206 | }; |
207 | |
208 | /* |
209 | * Some locks want to "refresh" potentially stale data when a |
210 | * meaningful (PRMODE or EXMODE) lock level is first obtained. If this |
211 | * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the |
212 | * individual lockres l_flags member from the ast function. It is |
213 | * expected that the locking wrapper will clear the |
214 | * OCFS2_LOCK_NEEDS_REFRESH flag when done. |
215 | */ |
216 | #define LOCK_TYPE_REQUIRES_REFRESH 0x1 |
217 | |
218 | /* |
219 | * Indicate that a lock type makes use of the lock value block. The |
220 | * ->set_lvb lock type callback must be defined. |
221 | */ |
222 | #define LOCK_TYPE_USES_LVB 0x2 |
223 | |
224 | static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = { |
225 | .get_osb = ocfs2_get_inode_osb, |
226 | .flags = 0, |
227 | }; |
228 | |
229 | static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = { |
230 | .get_osb = ocfs2_get_inode_osb, |
231 | .check_downconvert = ocfs2_check_meta_downconvert, |
232 | .set_lvb = ocfs2_set_meta_lvb, |
233 | .downconvert_worker = ocfs2_data_convert_worker, |
234 | .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, |
235 | }; |
236 | |
237 | static struct ocfs2_lock_res_ops ocfs2_super_lops = { |
238 | .flags = LOCK_TYPE_REQUIRES_REFRESH, |
239 | }; |
240 | |
241 | static struct ocfs2_lock_res_ops ocfs2_rename_lops = { |
242 | .flags = 0, |
243 | }; |
244 | |
245 | static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = { |
246 | .flags = 0, |
247 | }; |
248 | |
249 | static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = { |
250 | .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, |
251 | }; |
252 | |
253 | static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = { |
254 | .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, |
255 | }; |
256 | |
257 | static struct ocfs2_lock_res_ops ocfs2_dentry_lops = { |
258 | .get_osb = ocfs2_get_dentry_osb, |
259 | .post_unlock = ocfs2_dentry_post_unlock, |
260 | .downconvert_worker = ocfs2_dentry_convert_worker, |
261 | .flags = 0, |
262 | }; |
263 | |
264 | static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = { |
265 | .get_osb = ocfs2_get_inode_osb, |
266 | .flags = 0, |
267 | }; |
268 | |
269 | static struct ocfs2_lock_res_ops ocfs2_flock_lops = { |
270 | .get_osb = ocfs2_get_file_osb, |
271 | .flags = 0, |
272 | }; |
273 | |
274 | static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = { |
275 | .set_lvb = ocfs2_set_qinfo_lvb, |
276 | .get_osb = ocfs2_get_qinfo_osb, |
277 | .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB, |
278 | }; |
279 | |
280 | static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = { |
281 | .check_downconvert = ocfs2_check_refcount_downconvert, |
282 | .downconvert_worker = ocfs2_refcount_convert_worker, |
283 | .flags = 0, |
284 | }; |
285 | |
286 | static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres) |
287 | { |
288 | return lockres->l_type == OCFS2_LOCK_TYPE_META || |
289 | lockres->l_type == OCFS2_LOCK_TYPE_RW || |
290 | lockres->l_type == OCFS2_LOCK_TYPE_OPEN; |
291 | } |
292 | |
293 | static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb) |
294 | { |
295 | return container_of(lksb, struct ocfs2_lock_res, l_lksb); |
296 | } |
297 | |
298 | static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres) |
299 | { |
300 | BUG_ON(!ocfs2_is_inode_lock(lockres)); |
301 | |
302 | return (struct inode *) lockres->l_priv; |
303 | } |
304 | |
305 | static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres) |
306 | { |
307 | BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY); |
308 | |
309 | return (struct ocfs2_dentry_lock *)lockres->l_priv; |
310 | } |
311 | |
312 | static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres) |
313 | { |
314 | BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO); |
315 | |
316 | return (struct ocfs2_mem_dqinfo *)lockres->l_priv; |
317 | } |
318 | |
319 | static inline struct ocfs2_refcount_tree * |
320 | ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res) |
321 | { |
322 | return container_of(res, struct ocfs2_refcount_tree, rf_lockres); |
323 | } |
324 | |
325 | static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres) |
326 | { |
327 | if (lockres->l_ops->get_osb) |
328 | return lockres->l_ops->get_osb(lockres); |
329 | |
330 | return (struct ocfs2_super *)lockres->l_priv; |
331 | } |
332 | |
333 | static int ocfs2_lock_create(struct ocfs2_super *osb, |
334 | struct ocfs2_lock_res *lockres, |
335 | int level, |
336 | u32 dlm_flags); |
337 | static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, |
338 | int wanted); |
339 | static void __ocfs2_cluster_unlock(struct ocfs2_super *osb, |
340 | struct ocfs2_lock_res *lockres, |
341 | int level, unsigned long caller_ip); |
342 | static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb, |
343 | struct ocfs2_lock_res *lockres, |
344 | int level) |
345 | { |
346 | __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_); |
347 | } |
348 | |
349 | static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres); |
350 | static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres); |
351 | static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres); |
352 | static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level); |
353 | static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, |
354 | struct ocfs2_lock_res *lockres); |
355 | static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, |
356 | int convert); |
357 | #define ocfs2_log_dlm_error(_func, _err, _lockres) do { \ |
358 | if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \ |
359 | mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \ |
360 | _err, _func, _lockres->l_name); \ |
361 | else \ |
362 | mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \ |
363 | _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \ |
364 | (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \ |
365 | } while (0) |
366 | static int ocfs2_downconvert_thread(void *arg); |
367 | static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb, |
368 | struct ocfs2_lock_res *lockres); |
369 | static int ocfs2_inode_lock_update(struct inode *inode, |
370 | struct buffer_head **bh); |
371 | static void ocfs2_drop_osb_locks(struct ocfs2_super *osb); |
372 | static inline int ocfs2_highest_compat_lock_level(int level); |
373 | static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, |
374 | int new_level); |
375 | static int ocfs2_downconvert_lock(struct ocfs2_super *osb, |
376 | struct ocfs2_lock_res *lockres, |
377 | int new_level, |
378 | int lvb, |
379 | unsigned int generation); |
380 | static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, |
381 | struct ocfs2_lock_res *lockres); |
382 | static int ocfs2_cancel_convert(struct ocfs2_super *osb, |
383 | struct ocfs2_lock_res *lockres); |
384 | |
385 | |
386 | static void ocfs2_build_lock_name(enum ocfs2_lock_type type, |
387 | u64 blkno, |
388 | u32 generation, |
389 | char *name) |
390 | { |
391 | int len; |
392 | |
393 | BUG_ON(type >= OCFS2_NUM_LOCK_TYPES); |
394 | |
395 | len = snprintf(buf: name, OCFS2_LOCK_ID_MAX_LEN, fmt: "%c%s%016llx%08x" , |
396 | ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD, |
397 | (long long)blkno, generation); |
398 | |
399 | BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1)); |
400 | |
401 | mlog(0, "built lock resource with name: %s\n" , name); |
402 | } |
403 | |
404 | static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock); |
405 | |
406 | static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res, |
407 | struct ocfs2_dlm_debug *dlm_debug) |
408 | { |
409 | mlog(0, "Add tracking for lockres %s\n" , res->l_name); |
410 | |
411 | spin_lock(lock: &ocfs2_dlm_tracking_lock); |
412 | list_add(new: &res->l_debug_list, head: &dlm_debug->d_lockres_tracking); |
413 | spin_unlock(lock: &ocfs2_dlm_tracking_lock); |
414 | } |
415 | |
416 | static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res) |
417 | { |
418 | spin_lock(lock: &ocfs2_dlm_tracking_lock); |
419 | if (!list_empty(head: &res->l_debug_list)) |
420 | list_del_init(entry: &res->l_debug_list); |
421 | spin_unlock(lock: &ocfs2_dlm_tracking_lock); |
422 | } |
423 | |
424 | #ifdef CONFIG_OCFS2_FS_STATS |
425 | static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res) |
426 | { |
427 | res->l_lock_refresh = 0; |
428 | res->l_lock_wait = 0; |
429 | memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats)); |
430 | memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats)); |
431 | } |
432 | |
433 | static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level, |
434 | struct ocfs2_mask_waiter *mw, int ret) |
435 | { |
436 | u32 usec; |
437 | ktime_t kt; |
438 | struct ocfs2_lock_stats *stats; |
439 | |
440 | if (level == LKM_PRMODE) |
441 | stats = &res->l_lock_prmode; |
442 | else if (level == LKM_EXMODE) |
443 | stats = &res->l_lock_exmode; |
444 | else |
445 | return; |
446 | |
447 | kt = ktime_sub(ktime_get(), mw->mw_lock_start); |
448 | usec = ktime_to_us(kt); |
449 | |
450 | stats->ls_gets++; |
451 | stats->ls_total += ktime_to_ns(kt); |
452 | /* overflow */ |
453 | if (unlikely(stats->ls_gets == 0)) { |
454 | stats->ls_gets++; |
455 | stats->ls_total = ktime_to_ns(kt); |
456 | } |
457 | |
458 | if (stats->ls_max < usec) |
459 | stats->ls_max = usec; |
460 | |
461 | if (ret) |
462 | stats->ls_fail++; |
463 | |
464 | stats->ls_last = ktime_to_us(kt: ktime_get_real()); |
465 | } |
466 | |
467 | static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres) |
468 | { |
469 | lockres->l_lock_refresh++; |
470 | } |
471 | |
472 | static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres) |
473 | { |
474 | struct ocfs2_mask_waiter *mw; |
475 | |
476 | if (list_empty(head: &lockres->l_mask_waiters)) { |
477 | lockres->l_lock_wait = 0; |
478 | return; |
479 | } |
480 | |
481 | mw = list_first_entry(&lockres->l_mask_waiters, |
482 | struct ocfs2_mask_waiter, mw_item); |
483 | lockres->l_lock_wait = |
484 | ktime_to_us(kt: ktime_mono_to_real(mono: mw->mw_lock_start)); |
485 | } |
486 | |
487 | static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw) |
488 | { |
489 | mw->mw_lock_start = ktime_get(); |
490 | } |
491 | #else |
492 | static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res) |
493 | { |
494 | } |
495 | static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, |
496 | int level, struct ocfs2_mask_waiter *mw, int ret) |
497 | { |
498 | } |
499 | static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres) |
500 | { |
501 | } |
502 | static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres) |
503 | { |
504 | } |
505 | static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw) |
506 | { |
507 | } |
508 | #endif |
509 | |
510 | static void ocfs2_lock_res_init_common(struct ocfs2_super *osb, |
511 | struct ocfs2_lock_res *res, |
512 | enum ocfs2_lock_type type, |
513 | struct ocfs2_lock_res_ops *ops, |
514 | void *priv) |
515 | { |
516 | res->l_type = type; |
517 | res->l_ops = ops; |
518 | res->l_priv = priv; |
519 | |
520 | res->l_level = DLM_LOCK_IV; |
521 | res->l_requested = DLM_LOCK_IV; |
522 | res->l_blocking = DLM_LOCK_IV; |
523 | res->l_action = OCFS2_AST_INVALID; |
524 | res->l_unlock_action = OCFS2_UNLOCK_INVALID; |
525 | |
526 | res->l_flags = OCFS2_LOCK_INITIALIZED; |
527 | |
528 | ocfs2_add_lockres_tracking(res, dlm_debug: osb->osb_dlm_debug); |
529 | |
530 | ocfs2_init_lock_stats(res); |
531 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
532 | if (type != OCFS2_LOCK_TYPE_OPEN) |
533 | lockdep_init_map(lock: &res->l_lockdep_map, name: ocfs2_lock_type_strings[type], |
534 | key: &lockdep_keys[type], subclass: 0); |
535 | else |
536 | res->l_lockdep_map.key = NULL; |
537 | #endif |
538 | } |
539 | |
540 | void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res) |
541 | { |
542 | /* This also clears out the lock status block */ |
543 | memset(res, 0, sizeof(struct ocfs2_lock_res)); |
544 | spin_lock_init(&res->l_lock); |
545 | init_waitqueue_head(&res->l_event); |
546 | INIT_LIST_HEAD(list: &res->l_blocked_list); |
547 | INIT_LIST_HEAD(list: &res->l_mask_waiters); |
548 | INIT_LIST_HEAD(list: &res->l_holders); |
549 | } |
550 | |
551 | void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, |
552 | enum ocfs2_lock_type type, |
553 | unsigned int generation, |
554 | struct inode *inode) |
555 | { |
556 | struct ocfs2_lock_res_ops *ops; |
557 | |
558 | switch(type) { |
559 | case OCFS2_LOCK_TYPE_RW: |
560 | ops = &ocfs2_inode_rw_lops; |
561 | break; |
562 | case OCFS2_LOCK_TYPE_META: |
563 | ops = &ocfs2_inode_inode_lops; |
564 | break; |
565 | case OCFS2_LOCK_TYPE_OPEN: |
566 | ops = &ocfs2_inode_open_lops; |
567 | break; |
568 | default: |
569 | mlog_bug_on_msg(1, "type: %d\n" , type); |
570 | ops = NULL; /* thanks, gcc */ |
571 | break; |
572 | } |
573 | |
574 | ocfs2_build_lock_name(type, blkno: OCFS2_I(inode)->ip_blkno, |
575 | generation, name: res->l_name); |
576 | ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, priv: inode); |
577 | } |
578 | |
579 | static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres) |
580 | { |
581 | struct inode *inode = ocfs2_lock_res_inode(lockres); |
582 | |
583 | return OCFS2_SB(inode->i_sb); |
584 | } |
585 | |
586 | static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres) |
587 | { |
588 | struct ocfs2_mem_dqinfo *info = lockres->l_priv; |
589 | |
590 | return OCFS2_SB(info->dqi_gi.dqi_sb); |
591 | } |
592 | |
593 | static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres) |
594 | { |
595 | struct ocfs2_file_private *fp = lockres->l_priv; |
596 | |
597 | return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb); |
598 | } |
599 | |
600 | static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres) |
601 | { |
602 | __be64 inode_blkno_be; |
603 | |
604 | memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], |
605 | sizeof(__be64)); |
606 | |
607 | return be64_to_cpu(inode_blkno_be); |
608 | } |
609 | |
610 | static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres) |
611 | { |
612 | struct ocfs2_dentry_lock *dl = lockres->l_priv; |
613 | |
614 | return OCFS2_SB(dl->dl_inode->i_sb); |
615 | } |
616 | |
617 | void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl, |
618 | u64 parent, struct inode *inode) |
619 | { |
620 | int len; |
621 | u64 inode_blkno = OCFS2_I(inode)->ip_blkno; |
622 | __be64 inode_blkno_be = cpu_to_be64(inode_blkno); |
623 | struct ocfs2_lock_res *lockres = &dl->dl_lockres; |
624 | |
625 | ocfs2_lock_res_init_once(res: lockres); |
626 | |
627 | /* |
628 | * Unfortunately, the standard lock naming scheme won't work |
629 | * here because we have two 16 byte values to use. Instead, |
630 | * we'll stuff the inode number as a binary value. We still |
631 | * want error prints to show something without garbling the |
632 | * display, so drop a null byte in there before the inode |
633 | * number. A future version of OCFS2 will likely use all |
634 | * binary lock names. The stringified names have been a |
635 | * tremendous aid in debugging, but now that the debugfs |
636 | * interface exists, we can mangle things there if need be. |
637 | * |
638 | * NOTE: We also drop the standard "pad" value (the total lock |
639 | * name size stays the same though - the last part is all |
640 | * zeros due to the memset in ocfs2_lock_res_init_once() |
641 | */ |
642 | len = snprintf(buf: lockres->l_name, OCFS2_DENTRY_LOCK_INO_START, |
643 | fmt: "%c%016llx" , |
644 | ocfs2_lock_type_char(type: OCFS2_LOCK_TYPE_DENTRY), |
645 | (long long)parent); |
646 | |
647 | BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1)); |
648 | |
649 | memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be, |
650 | sizeof(__be64)); |
651 | |
652 | ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res: lockres, |
653 | type: OCFS2_LOCK_TYPE_DENTRY, ops: &ocfs2_dentry_lops, |
654 | priv: dl); |
655 | } |
656 | |
657 | static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res, |
658 | struct ocfs2_super *osb) |
659 | { |
660 | /* Superblock lockres doesn't come from a slab so we call init |
661 | * once on it manually. */ |
662 | ocfs2_lock_res_init_once(res); |
663 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO, |
664 | generation: 0, name: res->l_name); |
665 | ocfs2_lock_res_init_common(osb, res, type: OCFS2_LOCK_TYPE_SUPER, |
666 | ops: &ocfs2_super_lops, priv: osb); |
667 | } |
668 | |
669 | static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res, |
670 | struct ocfs2_super *osb) |
671 | { |
672 | /* Rename lockres doesn't come from a slab so we call init |
673 | * once on it manually. */ |
674 | ocfs2_lock_res_init_once(res); |
675 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_RENAME, blkno: 0, generation: 0, name: res->l_name); |
676 | ocfs2_lock_res_init_common(osb, res, type: OCFS2_LOCK_TYPE_RENAME, |
677 | ops: &ocfs2_rename_lops, priv: osb); |
678 | } |
679 | |
680 | static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res, |
681 | struct ocfs2_super *osb) |
682 | { |
683 | /* nfs_sync lockres doesn't come from a slab so we call init |
684 | * once on it manually. */ |
685 | ocfs2_lock_res_init_once(res); |
686 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_NFS_SYNC, blkno: 0, generation: 0, name: res->l_name); |
687 | ocfs2_lock_res_init_common(osb, res, type: OCFS2_LOCK_TYPE_NFS_SYNC, |
688 | ops: &ocfs2_nfs_sync_lops, priv: osb); |
689 | } |
690 | |
691 | static void ocfs2_nfs_sync_lock_init(struct ocfs2_super *osb) |
692 | { |
693 | ocfs2_nfs_sync_lock_res_init(res: &osb->osb_nfs_sync_lockres, osb); |
694 | init_rwsem(&osb->nfs_sync_rwlock); |
695 | } |
696 | |
697 | void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb) |
698 | { |
699 | struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; |
700 | |
701 | /* Only one trimfs thread are allowed to work at the same time. */ |
702 | mutex_lock(&osb->obs_trim_fs_mutex); |
703 | |
704 | ocfs2_lock_res_init_once(res: lockres); |
705 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_TRIM_FS, blkno: 0, generation: 0, name: lockres->l_name); |
706 | ocfs2_lock_res_init_common(osb, res: lockres, type: OCFS2_LOCK_TYPE_TRIM_FS, |
707 | ops: &ocfs2_trim_fs_lops, priv: osb); |
708 | } |
709 | |
710 | void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb) |
711 | { |
712 | struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; |
713 | |
714 | ocfs2_simple_drop_lockres(osb, lockres); |
715 | ocfs2_lock_res_free(res: lockres); |
716 | |
717 | mutex_unlock(lock: &osb->obs_trim_fs_mutex); |
718 | } |
719 | |
720 | static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res, |
721 | struct ocfs2_super *osb) |
722 | { |
723 | ocfs2_lock_res_init_once(res); |
724 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_ORPHAN_SCAN, blkno: 0, generation: 0, name: res->l_name); |
725 | ocfs2_lock_res_init_common(osb, res, type: OCFS2_LOCK_TYPE_ORPHAN_SCAN, |
726 | ops: &ocfs2_orphan_scan_lops, priv: osb); |
727 | } |
728 | |
729 | void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres, |
730 | struct ocfs2_file_private *fp) |
731 | { |
732 | struct inode *inode = fp->fp_file->f_mapping->host; |
733 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
734 | |
735 | ocfs2_lock_res_init_once(res: lockres); |
736 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_FLOCK, blkno: oi->ip_blkno, |
737 | generation: inode->i_generation, name: lockres->l_name); |
738 | ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res: lockres, |
739 | type: OCFS2_LOCK_TYPE_FLOCK, ops: &ocfs2_flock_lops, |
740 | priv: fp); |
741 | lockres->l_flags |= OCFS2_LOCK_NOCACHE; |
742 | } |
743 | |
744 | void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres, |
745 | struct ocfs2_mem_dqinfo *info) |
746 | { |
747 | ocfs2_lock_res_init_once(res: lockres); |
748 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_QINFO, blkno: info->dqi_gi.dqi_type, |
749 | generation: 0, name: lockres->l_name); |
750 | ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), res: lockres, |
751 | type: OCFS2_LOCK_TYPE_QINFO, ops: &ocfs2_qinfo_lops, |
752 | priv: info); |
753 | } |
754 | |
755 | void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres, |
756 | struct ocfs2_super *osb, u64 ref_blkno, |
757 | unsigned int generation) |
758 | { |
759 | ocfs2_lock_res_init_once(res: lockres); |
760 | ocfs2_build_lock_name(type: OCFS2_LOCK_TYPE_REFCOUNT, blkno: ref_blkno, |
761 | generation, name: lockres->l_name); |
762 | ocfs2_lock_res_init_common(osb, res: lockres, type: OCFS2_LOCK_TYPE_REFCOUNT, |
763 | ops: &ocfs2_refcount_block_lops, priv: osb); |
764 | } |
765 | |
766 | void ocfs2_lock_res_free(struct ocfs2_lock_res *res) |
767 | { |
768 | if (!(res->l_flags & OCFS2_LOCK_INITIALIZED)) |
769 | return; |
770 | |
771 | ocfs2_remove_lockres_tracking(res); |
772 | |
773 | mlog_bug_on_msg(!list_empty(&res->l_blocked_list), |
774 | "Lockres %s is on the blocked list\n" , |
775 | res->l_name); |
776 | mlog_bug_on_msg(!list_empty(&res->l_mask_waiters), |
777 | "Lockres %s has mask waiters pending\n" , |
778 | res->l_name); |
779 | mlog_bug_on_msg(spin_is_locked(&res->l_lock), |
780 | "Lockres %s is locked\n" , |
781 | res->l_name); |
782 | mlog_bug_on_msg(res->l_ro_holders, |
783 | "Lockres %s has %u ro holders\n" , |
784 | res->l_name, res->l_ro_holders); |
785 | mlog_bug_on_msg(res->l_ex_holders, |
786 | "Lockres %s has %u ex holders\n" , |
787 | res->l_name, res->l_ex_holders); |
788 | |
789 | /* Need to clear out the lock status block for the dlm */ |
790 | memset(&res->l_lksb, 0, sizeof(res->l_lksb)); |
791 | |
792 | res->l_flags = 0UL; |
793 | } |
794 | |
795 | /* |
796 | * Keep a list of processes who have interest in a lockres. |
797 | * Note: this is now only uesed for check recursive cluster locking. |
798 | */ |
799 | static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, |
800 | struct ocfs2_lock_holder *oh) |
801 | { |
802 | INIT_LIST_HEAD(list: &oh->oh_list); |
803 | oh->oh_owner_pid = get_pid(pid: task_pid(current)); |
804 | |
805 | spin_lock(lock: &lockres->l_lock); |
806 | list_add_tail(new: &oh->oh_list, head: &lockres->l_holders); |
807 | spin_unlock(lock: &lockres->l_lock); |
808 | } |
809 | |
810 | static struct ocfs2_lock_holder * |
811 | ocfs2_pid_holder(struct ocfs2_lock_res *lockres, |
812 | struct pid *pid) |
813 | { |
814 | struct ocfs2_lock_holder *oh; |
815 | |
816 | spin_lock(lock: &lockres->l_lock); |
817 | list_for_each_entry(oh, &lockres->l_holders, oh_list) { |
818 | if (oh->oh_owner_pid == pid) { |
819 | spin_unlock(lock: &lockres->l_lock); |
820 | return oh; |
821 | } |
822 | } |
823 | spin_unlock(lock: &lockres->l_lock); |
824 | return NULL; |
825 | } |
826 | |
827 | static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, |
828 | struct ocfs2_lock_holder *oh) |
829 | { |
830 | spin_lock(lock: &lockres->l_lock); |
831 | list_del(entry: &oh->oh_list); |
832 | spin_unlock(lock: &lockres->l_lock); |
833 | |
834 | put_pid(pid: oh->oh_owner_pid); |
835 | } |
836 | |
837 | |
838 | static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres, |
839 | int level) |
840 | { |
841 | BUG_ON(!lockres); |
842 | |
843 | switch(level) { |
844 | case DLM_LOCK_EX: |
845 | lockres->l_ex_holders++; |
846 | break; |
847 | case DLM_LOCK_PR: |
848 | lockres->l_ro_holders++; |
849 | break; |
850 | default: |
851 | BUG(); |
852 | } |
853 | } |
854 | |
855 | static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres, |
856 | int level) |
857 | { |
858 | BUG_ON(!lockres); |
859 | |
860 | switch(level) { |
861 | case DLM_LOCK_EX: |
862 | BUG_ON(!lockres->l_ex_holders); |
863 | lockres->l_ex_holders--; |
864 | break; |
865 | case DLM_LOCK_PR: |
866 | BUG_ON(!lockres->l_ro_holders); |
867 | lockres->l_ro_holders--; |
868 | break; |
869 | default: |
870 | BUG(); |
871 | } |
872 | } |
873 | |
874 | /* WARNING: This function lives in a world where the only three lock |
875 | * levels are EX, PR, and NL. It *will* have to be adjusted when more |
876 | * lock types are added. */ |
877 | static inline int ocfs2_highest_compat_lock_level(int level) |
878 | { |
879 | int new_level = DLM_LOCK_EX; |
880 | |
881 | if (level == DLM_LOCK_EX) |
882 | new_level = DLM_LOCK_NL; |
883 | else if (level == DLM_LOCK_PR) |
884 | new_level = DLM_LOCK_PR; |
885 | return new_level; |
886 | } |
887 | |
888 | static void lockres_set_flags(struct ocfs2_lock_res *lockres, |
889 | unsigned long newflags) |
890 | { |
891 | struct ocfs2_mask_waiter *mw, *tmp; |
892 | |
893 | assert_spin_locked(&lockres->l_lock); |
894 | |
895 | lockres->l_flags = newflags; |
896 | |
897 | list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) { |
898 | if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) |
899 | continue; |
900 | |
901 | list_del_init(entry: &mw->mw_item); |
902 | mw->mw_status = 0; |
903 | complete(&mw->mw_complete); |
904 | ocfs2_track_lock_wait(lockres); |
905 | } |
906 | } |
907 | static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or) |
908 | { |
909 | lockres_set_flags(lockres, newflags: lockres->l_flags | or); |
910 | } |
911 | static void lockres_clear_flags(struct ocfs2_lock_res *lockres, |
912 | unsigned long clear) |
913 | { |
914 | lockres_set_flags(lockres, newflags: lockres->l_flags & ~clear); |
915 | } |
916 | |
917 | static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres) |
918 | { |
919 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); |
920 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); |
921 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); |
922 | BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); |
923 | |
924 | lockres->l_level = lockres->l_requested; |
925 | if (lockres->l_level <= |
926 | ocfs2_highest_compat_lock_level(level: lockres->l_blocking)) { |
927 | lockres->l_blocking = DLM_LOCK_NL; |
928 | lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); |
929 | } |
930 | lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); |
931 | } |
932 | |
933 | static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres) |
934 | { |
935 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); |
936 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); |
937 | |
938 | /* Convert from RO to EX doesn't really need anything as our |
939 | * information is already up to data. Convert from NL to |
940 | * *anything* however should mark ourselves as needing an |
941 | * update */ |
942 | if (lockres->l_level == DLM_LOCK_NL && |
943 | lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) |
944 | lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); |
945 | |
946 | lockres->l_level = lockres->l_requested; |
947 | |
948 | /* |
949 | * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing |
950 | * the OCFS2_LOCK_BUSY flag to prevent the dc thread from |
951 | * downconverting the lock before the upconvert has fully completed. |
952 | * Do not prevent the dc thread from downconverting if NONBLOCK lock |
953 | * had already returned. |
954 | */ |
955 | if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED)) |
956 | lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); |
957 | else |
958 | lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED); |
959 | |
960 | lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); |
961 | } |
962 | |
963 | static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres) |
964 | { |
965 | BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY))); |
966 | BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); |
967 | |
968 | if (lockres->l_requested > DLM_LOCK_NL && |
969 | !(lockres->l_flags & OCFS2_LOCK_LOCAL) && |
970 | lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) |
971 | lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); |
972 | |
973 | lockres->l_level = lockres->l_requested; |
974 | lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED); |
975 | lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); |
976 | } |
977 | |
978 | static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, |
979 | int level) |
980 | { |
981 | int needs_downconvert = 0; |
982 | |
983 | assert_spin_locked(&lockres->l_lock); |
984 | |
985 | if (level > lockres->l_blocking) { |
986 | /* only schedule a downconvert if we haven't already scheduled |
987 | * one that goes low enough to satisfy the level we're |
988 | * blocking. this also catches the case where we get |
989 | * duplicate BASTs */ |
990 | if (ocfs2_highest_compat_lock_level(level) < |
991 | ocfs2_highest_compat_lock_level(level: lockres->l_blocking)) |
992 | needs_downconvert = 1; |
993 | |
994 | lockres->l_blocking = level; |
995 | } |
996 | |
997 | mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n" , |
998 | lockres->l_name, level, lockres->l_level, lockres->l_blocking, |
999 | needs_downconvert); |
1000 | |
1001 | if (needs_downconvert) |
1002 | lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); |
1003 | mlog(0, "needs_downconvert = %d\n" , needs_downconvert); |
1004 | return needs_downconvert; |
1005 | } |
1006 | |
1007 | /* |
1008 | * OCFS2_LOCK_PENDING and l_pending_gen. |
1009 | * |
1010 | * Why does OCFS2_LOCK_PENDING exist? To close a race between setting |
1011 | * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock() |
1012 | * for more details on the race. |
1013 | * |
1014 | * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces |
1015 | * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock() |
1016 | * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear |
1017 | * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns, |
1018 | * the caller is going to try to clear PENDING again. If nothing else is |
1019 | * happening, __lockres_clear_pending() sees PENDING is unset and does |
1020 | * nothing. |
1021 | * |
1022 | * But what if another path (eg downconvert thread) has just started a |
1023 | * new locking action? The other path has re-set PENDING. Our path |
1024 | * cannot clear PENDING, because that will re-open the original race |
1025 | * window. |
1026 | * |
1027 | * [Example] |
1028 | * |
1029 | * ocfs2_meta_lock() |
1030 | * ocfs2_cluster_lock() |
1031 | * set BUSY |
1032 | * set PENDING |
1033 | * drop l_lock |
1034 | * ocfs2_dlm_lock() |
1035 | * ocfs2_locking_ast() ocfs2_downconvert_thread() |
1036 | * clear PENDING ocfs2_unblock_lock() |
1037 | * take_l_lock |
1038 | * !BUSY |
1039 | * ocfs2_prepare_downconvert() |
1040 | * set BUSY |
1041 | * set PENDING |
1042 | * drop l_lock |
1043 | * take l_lock |
1044 | * clear PENDING |
1045 | * drop l_lock |
1046 | * <window> |
1047 | * ocfs2_dlm_lock() |
1048 | * |
1049 | * So as you can see, we now have a window where l_lock is not held, |
1050 | * PENDING is not set, and ocfs2_dlm_lock() has not been called. |
1051 | * |
1052 | * The core problem is that ocfs2_cluster_lock() has cleared the PENDING |
1053 | * set by ocfs2_prepare_downconvert(). That wasn't nice. |
1054 | * |
1055 | * To solve this we introduce l_pending_gen. A call to |
1056 | * lockres_clear_pending() will only do so when it is passed a generation |
1057 | * number that matches the lockres. lockres_set_pending() will return the |
1058 | * current generation number. When ocfs2_cluster_lock() goes to clear |
1059 | * PENDING, it passes the generation it got from set_pending(). In our |
1060 | * example above, the generation numbers will *not* match. Thus, |
1061 | * ocfs2_cluster_lock() will not clear the PENDING set by |
1062 | * ocfs2_prepare_downconvert(). |
1063 | */ |
1064 | |
1065 | /* Unlocked version for ocfs2_locking_ast() */ |
1066 | static void __lockres_clear_pending(struct ocfs2_lock_res *lockres, |
1067 | unsigned int generation, |
1068 | struct ocfs2_super *osb) |
1069 | { |
1070 | assert_spin_locked(&lockres->l_lock); |
1071 | |
1072 | /* |
1073 | * The ast and locking functions can race us here. The winner |
1074 | * will clear pending, the loser will not. |
1075 | */ |
1076 | if (!(lockres->l_flags & OCFS2_LOCK_PENDING) || |
1077 | (lockres->l_pending_gen != generation)) |
1078 | return; |
1079 | |
1080 | lockres_clear_flags(lockres, OCFS2_LOCK_PENDING); |
1081 | lockres->l_pending_gen++; |
1082 | |
1083 | /* |
1084 | * The downconvert thread may have skipped us because we |
1085 | * were PENDING. Wake it up. |
1086 | */ |
1087 | if (lockres->l_flags & OCFS2_LOCK_BLOCKED) |
1088 | ocfs2_wake_downconvert_thread(osb); |
1089 | } |
1090 | |
1091 | /* Locked version for callers of ocfs2_dlm_lock() */ |
1092 | static void lockres_clear_pending(struct ocfs2_lock_res *lockres, |
1093 | unsigned int generation, |
1094 | struct ocfs2_super *osb) |
1095 | { |
1096 | unsigned long flags; |
1097 | |
1098 | spin_lock_irqsave(&lockres->l_lock, flags); |
1099 | __lockres_clear_pending(lockres, generation, osb); |
1100 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1101 | } |
1102 | |
1103 | static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres) |
1104 | { |
1105 | assert_spin_locked(&lockres->l_lock); |
1106 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); |
1107 | |
1108 | lockres_or_flags(lockres, OCFS2_LOCK_PENDING); |
1109 | |
1110 | return lockres->l_pending_gen; |
1111 | } |
1112 | |
1113 | static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level) |
1114 | { |
1115 | struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); |
1116 | struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); |
1117 | int needs_downconvert; |
1118 | unsigned long flags; |
1119 | |
1120 | BUG_ON(level <= DLM_LOCK_NL); |
1121 | |
1122 | mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, " |
1123 | "type %s\n" , lockres->l_name, level, lockres->l_level, |
1124 | ocfs2_lock_type_string(lockres->l_type)); |
1125 | |
1126 | /* |
1127 | * We can skip the bast for locks which don't enable caching - |
1128 | * they'll be dropped at the earliest possible time anyway. |
1129 | */ |
1130 | if (lockres->l_flags & OCFS2_LOCK_NOCACHE) |
1131 | return; |
1132 | |
1133 | spin_lock_irqsave(&lockres->l_lock, flags); |
1134 | needs_downconvert = ocfs2_generic_handle_bast(lockres, level); |
1135 | if (needs_downconvert) |
1136 | ocfs2_schedule_blocked_lock(osb, lockres); |
1137 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1138 | |
1139 | wake_up(&lockres->l_event); |
1140 | |
1141 | ocfs2_wake_downconvert_thread(osb); |
1142 | } |
1143 | |
1144 | static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb) |
1145 | { |
1146 | struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); |
1147 | struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); |
1148 | unsigned long flags; |
1149 | int status; |
1150 | |
1151 | spin_lock_irqsave(&lockres->l_lock, flags); |
1152 | |
1153 | status = ocfs2_dlm_lock_status(lksb: &lockres->l_lksb); |
1154 | |
1155 | if (status == -EAGAIN) { |
1156 | lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); |
1157 | goto out; |
1158 | } |
1159 | |
1160 | if (status) { |
1161 | mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n" , |
1162 | lockres->l_name, status); |
1163 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1164 | return; |
1165 | } |
1166 | |
1167 | mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, " |
1168 | "level %d => %d\n" , lockres->l_name, lockres->l_action, |
1169 | lockres->l_unlock_action, lockres->l_level, lockres->l_requested); |
1170 | |
1171 | switch(lockres->l_action) { |
1172 | case OCFS2_AST_ATTACH: |
1173 | ocfs2_generic_handle_attach_action(lockres); |
1174 | lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL); |
1175 | break; |
1176 | case OCFS2_AST_CONVERT: |
1177 | ocfs2_generic_handle_convert_action(lockres); |
1178 | break; |
1179 | case OCFS2_AST_DOWNCONVERT: |
1180 | ocfs2_generic_handle_downconvert_action(lockres); |
1181 | break; |
1182 | default: |
1183 | mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, " |
1184 | "flags 0x%lx, unlock: %u\n" , |
1185 | lockres->l_name, lockres->l_action, lockres->l_flags, |
1186 | lockres->l_unlock_action); |
1187 | BUG(); |
1188 | } |
1189 | out: |
1190 | /* set it to something invalid so if we get called again we |
1191 | * can catch it. */ |
1192 | lockres->l_action = OCFS2_AST_INVALID; |
1193 | |
1194 | /* Did we try to cancel this lock? Clear that state */ |
1195 | if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) |
1196 | lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; |
1197 | |
1198 | /* |
1199 | * We may have beaten the locking functions here. We certainly |
1200 | * know that dlm_lock() has been called :-) |
1201 | * Because we can't have two lock calls in flight at once, we |
1202 | * can use lockres->l_pending_gen. |
1203 | */ |
1204 | __lockres_clear_pending(lockres, generation: lockres->l_pending_gen, osb); |
1205 | |
1206 | wake_up(&lockres->l_event); |
1207 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1208 | } |
1209 | |
1210 | static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error) |
1211 | { |
1212 | struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); |
1213 | unsigned long flags; |
1214 | |
1215 | mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n" , |
1216 | lockres->l_name, lockres->l_unlock_action); |
1217 | |
1218 | spin_lock_irqsave(&lockres->l_lock, flags); |
1219 | if (error) { |
1220 | mlog(ML_ERROR, "Dlm passes error %d for lock %s, " |
1221 | "unlock_action %d\n" , error, lockres->l_name, |
1222 | lockres->l_unlock_action); |
1223 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1224 | return; |
1225 | } |
1226 | |
1227 | switch(lockres->l_unlock_action) { |
1228 | case OCFS2_UNLOCK_CANCEL_CONVERT: |
1229 | mlog(0, "Cancel convert success for %s\n" , lockres->l_name); |
1230 | lockres->l_action = OCFS2_AST_INVALID; |
1231 | /* Downconvert thread may have requeued this lock, we |
1232 | * need to wake it. */ |
1233 | if (lockres->l_flags & OCFS2_LOCK_BLOCKED) |
1234 | ocfs2_wake_downconvert_thread(osb: ocfs2_get_lockres_osb(lockres)); |
1235 | break; |
1236 | case OCFS2_UNLOCK_DROP_LOCK: |
1237 | lockres->l_level = DLM_LOCK_IV; |
1238 | break; |
1239 | default: |
1240 | BUG(); |
1241 | } |
1242 | |
1243 | lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); |
1244 | lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; |
1245 | wake_up(&lockres->l_event); |
1246 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1247 | } |
1248 | |
1249 | /* |
1250 | * This is the filesystem locking protocol. It provides the lock handling |
1251 | * hooks for the underlying DLM. It has a maximum version number. |
1252 | * The version number allows interoperability with systems running at |
1253 | * the same major number and an equal or smaller minor number. |
1254 | * |
1255 | * Whenever the filesystem does new things with locks (adds or removes a |
1256 | * lock, orders them differently, does different things underneath a lock), |
1257 | * the version must be changed. The protocol is negotiated when joining |
1258 | * the dlm domain. A node may join the domain if its major version is |
1259 | * identical to all other nodes and its minor version is greater than |
1260 | * or equal to all other nodes. When its minor version is greater than |
1261 | * the other nodes, it will run at the minor version specified by the |
1262 | * other nodes. |
1263 | * |
1264 | * If a locking change is made that will not be compatible with older |
1265 | * versions, the major number must be increased and the minor version set |
1266 | * to zero. If a change merely adds a behavior that can be disabled when |
1267 | * speaking to older versions, the minor version must be increased. If a |
1268 | * change adds a fully backwards compatible change (eg, LVB changes that |
1269 | * are just ignored by older versions), the version does not need to be |
1270 | * updated. |
1271 | */ |
1272 | static struct ocfs2_locking_protocol lproto = { |
1273 | .lp_max_version = { |
1274 | .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR, |
1275 | .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR, |
1276 | }, |
1277 | .lp_lock_ast = ocfs2_locking_ast, |
1278 | .lp_blocking_ast = ocfs2_blocking_ast, |
1279 | .lp_unlock_ast = ocfs2_unlock_ast, |
1280 | }; |
1281 | |
1282 | void ocfs2_set_locking_protocol(void) |
1283 | { |
1284 | ocfs2_stack_glue_set_max_proto_version(max_proto: &lproto.lp_max_version); |
1285 | } |
1286 | |
1287 | static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, |
1288 | int convert) |
1289 | { |
1290 | unsigned long flags; |
1291 | |
1292 | spin_lock_irqsave(&lockres->l_lock, flags); |
1293 | lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); |
1294 | lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); |
1295 | if (convert) |
1296 | lockres->l_action = OCFS2_AST_INVALID; |
1297 | else |
1298 | lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; |
1299 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1300 | |
1301 | wake_up(&lockres->l_event); |
1302 | } |
1303 | |
1304 | /* Note: If we detect another process working on the lock (i.e., |
1305 | * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller |
1306 | * to do the right thing in that case. |
1307 | */ |
1308 | static int ocfs2_lock_create(struct ocfs2_super *osb, |
1309 | struct ocfs2_lock_res *lockres, |
1310 | int level, |
1311 | u32 dlm_flags) |
1312 | { |
1313 | int ret = 0; |
1314 | unsigned long flags; |
1315 | unsigned int gen; |
1316 | |
1317 | mlog(0, "lock %s, level = %d, flags = %u\n" , lockres->l_name, level, |
1318 | dlm_flags); |
1319 | |
1320 | spin_lock_irqsave(&lockres->l_lock, flags); |
1321 | if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) || |
1322 | (lockres->l_flags & OCFS2_LOCK_BUSY)) { |
1323 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1324 | goto bail; |
1325 | } |
1326 | |
1327 | lockres->l_action = OCFS2_AST_ATTACH; |
1328 | lockres->l_requested = level; |
1329 | lockres_or_flags(lockres, OCFS2_LOCK_BUSY); |
1330 | gen = lockres_set_pending(lockres); |
1331 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1332 | |
1333 | ret = ocfs2_dlm_lock(conn: osb->cconn, |
1334 | mode: level, |
1335 | lksb: &lockres->l_lksb, |
1336 | flags: dlm_flags, |
1337 | name: lockres->l_name, |
1338 | OCFS2_LOCK_ID_MAX_LEN - 1); |
1339 | lockres_clear_pending(lockres, generation: gen, osb); |
1340 | if (ret) { |
1341 | ocfs2_log_dlm_error("ocfs2_dlm_lock" , ret, lockres); |
1342 | ocfs2_recover_from_dlm_error(lockres, convert: 1); |
1343 | } |
1344 | |
1345 | mlog(0, "lock %s, return from ocfs2_dlm_lock\n" , lockres->l_name); |
1346 | |
1347 | bail: |
1348 | return ret; |
1349 | } |
1350 | |
1351 | static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres, |
1352 | int flag) |
1353 | { |
1354 | unsigned long flags; |
1355 | int ret; |
1356 | |
1357 | spin_lock_irqsave(&lockres->l_lock, flags); |
1358 | ret = lockres->l_flags & flag; |
1359 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1360 | |
1361 | return ret; |
1362 | } |
1363 | |
1364 | static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres) |
1365 | |
1366 | { |
1367 | wait_event(lockres->l_event, |
1368 | !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY)); |
1369 | } |
1370 | |
1371 | static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres) |
1372 | |
1373 | { |
1374 | wait_event(lockres->l_event, |
1375 | !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING)); |
1376 | } |
1377 | |
1378 | /* predict what lock level we'll be dropping down to on behalf |
1379 | * of another node, and return true if the currently wanted |
1380 | * level will be compatible with it. */ |
1381 | static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, |
1382 | int wanted) |
1383 | { |
1384 | BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); |
1385 | |
1386 | return wanted <= ocfs2_highest_compat_lock_level(level: lockres->l_blocking); |
1387 | } |
1388 | |
1389 | static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw) |
1390 | { |
1391 | INIT_LIST_HEAD(list: &mw->mw_item); |
1392 | init_completion(x: &mw->mw_complete); |
1393 | ocfs2_init_start_time(mw); |
1394 | } |
1395 | |
1396 | static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw) |
1397 | { |
1398 | wait_for_completion(&mw->mw_complete); |
1399 | /* Re-arm the completion in case we want to wait on it again */ |
1400 | reinit_completion(x: &mw->mw_complete); |
1401 | return mw->mw_status; |
1402 | } |
1403 | |
1404 | static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres, |
1405 | struct ocfs2_mask_waiter *mw, |
1406 | unsigned long mask, |
1407 | unsigned long goal) |
1408 | { |
1409 | BUG_ON(!list_empty(&mw->mw_item)); |
1410 | |
1411 | assert_spin_locked(&lockres->l_lock); |
1412 | |
1413 | list_add_tail(new: &mw->mw_item, head: &lockres->l_mask_waiters); |
1414 | mw->mw_mask = mask; |
1415 | mw->mw_goal = goal; |
1416 | ocfs2_track_lock_wait(lockres); |
1417 | } |
1418 | |
1419 | /* returns 0 if the mw that was removed was already satisfied, -EBUSY |
1420 | * if the mask still hadn't reached its goal */ |
1421 | static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, |
1422 | struct ocfs2_mask_waiter *mw) |
1423 | { |
1424 | int ret = 0; |
1425 | |
1426 | assert_spin_locked(&lockres->l_lock); |
1427 | if (!list_empty(head: &mw->mw_item)) { |
1428 | if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) |
1429 | ret = -EBUSY; |
1430 | |
1431 | list_del_init(entry: &mw->mw_item); |
1432 | init_completion(x: &mw->mw_complete); |
1433 | ocfs2_track_lock_wait(lockres); |
1434 | } |
1435 | |
1436 | return ret; |
1437 | } |
1438 | |
1439 | static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, |
1440 | struct ocfs2_mask_waiter *mw) |
1441 | { |
1442 | unsigned long flags; |
1443 | int ret = 0; |
1444 | |
1445 | spin_lock_irqsave(&lockres->l_lock, flags); |
1446 | ret = __lockres_remove_mask_waiter(lockres, mw); |
1447 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1448 | |
1449 | return ret; |
1450 | |
1451 | } |
1452 | |
1453 | static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw, |
1454 | struct ocfs2_lock_res *lockres) |
1455 | { |
1456 | int ret; |
1457 | |
1458 | ret = wait_for_completion_interruptible(x: &mw->mw_complete); |
1459 | if (ret) |
1460 | lockres_remove_mask_waiter(lockres, mw); |
1461 | else |
1462 | ret = mw->mw_status; |
1463 | /* Re-arm the completion in case we want to wait on it again */ |
1464 | reinit_completion(x: &mw->mw_complete); |
1465 | return ret; |
1466 | } |
1467 | |
1468 | static int __ocfs2_cluster_lock(struct ocfs2_super *osb, |
1469 | struct ocfs2_lock_res *lockres, |
1470 | int level, |
1471 | u32 lkm_flags, |
1472 | int arg_flags, |
1473 | int l_subclass, |
1474 | unsigned long caller_ip) |
1475 | { |
1476 | struct ocfs2_mask_waiter mw; |
1477 | int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR); |
1478 | int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */ |
1479 | unsigned long flags; |
1480 | unsigned int gen; |
1481 | int noqueue_attempted = 0; |
1482 | int dlm_locked = 0; |
1483 | int kick_dc = 0; |
1484 | |
1485 | if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) { |
1486 | mlog_errno(-EINVAL); |
1487 | return -EINVAL; |
1488 | } |
1489 | |
1490 | ocfs2_init_mask_waiter(mw: &mw); |
1491 | |
1492 | if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) |
1493 | lkm_flags |= DLM_LKF_VALBLK; |
1494 | |
1495 | again: |
1496 | wait = 0; |
1497 | |
1498 | spin_lock_irqsave(&lockres->l_lock, flags); |
1499 | |
1500 | if (catch_signals && signal_pending(current)) { |
1501 | ret = -ERESTARTSYS; |
1502 | goto unlock; |
1503 | } |
1504 | |
1505 | mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING, |
1506 | "Cluster lock called on freeing lockres %s! flags " |
1507 | "0x%lx\n" , lockres->l_name, lockres->l_flags); |
1508 | |
1509 | /* We only compare against the currently granted level |
1510 | * here. If the lock is blocked waiting on a downconvert, |
1511 | * we'll get caught below. */ |
1512 | if (lockres->l_flags & OCFS2_LOCK_BUSY && |
1513 | level > lockres->l_level) { |
1514 | /* is someone sitting in dlm_lock? If so, wait on |
1515 | * them. */ |
1516 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_BUSY, goal: 0); |
1517 | wait = 1; |
1518 | goto unlock; |
1519 | } |
1520 | |
1521 | if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) { |
1522 | /* |
1523 | * We've upconverted. If the lock now has a level we can |
1524 | * work with, we take it. If, however, the lock is not at the |
1525 | * required level, we go thru the full cycle. One way this could |
1526 | * happen is if a process requesting an upconvert to PR is |
1527 | * closely followed by another requesting upconvert to an EX. |
1528 | * If the process requesting EX lands here, we want it to |
1529 | * continue attempting to upconvert and let the process |
1530 | * requesting PR take the lock. |
1531 | * If multiple processes request upconvert to PR, the first one |
1532 | * here will take the lock. The others will have to go thru the |
1533 | * OCFS2_LOCK_BLOCKED check to ensure that there is no pending |
1534 | * downconvert request. |
1535 | */ |
1536 | if (level <= lockres->l_level) |
1537 | goto update_holders; |
1538 | } |
1539 | |
1540 | if (lockres->l_flags & OCFS2_LOCK_BLOCKED && |
1541 | !ocfs2_may_continue_on_blocked_lock(lockres, wanted: level)) { |
1542 | /* is the lock is currently blocked on behalf of |
1543 | * another node */ |
1544 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_BLOCKED, goal: 0); |
1545 | wait = 1; |
1546 | goto unlock; |
1547 | } |
1548 | |
1549 | if (level > lockres->l_level) { |
1550 | if (noqueue_attempted > 0) { |
1551 | ret = -EAGAIN; |
1552 | goto unlock; |
1553 | } |
1554 | if (lkm_flags & DLM_LKF_NOQUEUE) |
1555 | noqueue_attempted = 1; |
1556 | |
1557 | if (lockres->l_action != OCFS2_AST_INVALID) |
1558 | mlog(ML_ERROR, "lockres %s has action %u pending\n" , |
1559 | lockres->l_name, lockres->l_action); |
1560 | |
1561 | if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { |
1562 | lockres->l_action = OCFS2_AST_ATTACH; |
1563 | lkm_flags &= ~DLM_LKF_CONVERT; |
1564 | } else { |
1565 | lockres->l_action = OCFS2_AST_CONVERT; |
1566 | lkm_flags |= DLM_LKF_CONVERT; |
1567 | } |
1568 | |
1569 | lockres->l_requested = level; |
1570 | lockres_or_flags(lockres, OCFS2_LOCK_BUSY); |
1571 | gen = lockres_set_pending(lockres); |
1572 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1573 | |
1574 | BUG_ON(level == DLM_LOCK_IV); |
1575 | BUG_ON(level == DLM_LOCK_NL); |
1576 | |
1577 | mlog(ML_BASTS, "lockres %s, convert from %d to %d\n" , |
1578 | lockres->l_name, lockres->l_level, level); |
1579 | |
1580 | /* call dlm_lock to upgrade lock now */ |
1581 | ret = ocfs2_dlm_lock(conn: osb->cconn, |
1582 | mode: level, |
1583 | lksb: &lockres->l_lksb, |
1584 | flags: lkm_flags, |
1585 | name: lockres->l_name, |
1586 | OCFS2_LOCK_ID_MAX_LEN - 1); |
1587 | lockres_clear_pending(lockres, generation: gen, osb); |
1588 | if (ret) { |
1589 | if (!(lkm_flags & DLM_LKF_NOQUEUE) || |
1590 | (ret != -EAGAIN)) { |
1591 | ocfs2_log_dlm_error("ocfs2_dlm_lock" , |
1592 | ret, lockres); |
1593 | } |
1594 | ocfs2_recover_from_dlm_error(lockres, convert: 1); |
1595 | goto out; |
1596 | } |
1597 | dlm_locked = 1; |
1598 | |
1599 | mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n" , |
1600 | lockres->l_name); |
1601 | |
1602 | /* At this point we've gone inside the dlm and need to |
1603 | * complete our work regardless. */ |
1604 | catch_signals = 0; |
1605 | |
1606 | /* wait for busy to clear and carry on */ |
1607 | goto again; |
1608 | } |
1609 | |
1610 | update_holders: |
1611 | /* Ok, if we get here then we're good to go. */ |
1612 | ocfs2_inc_holders(lockres, level); |
1613 | |
1614 | ret = 0; |
1615 | unlock: |
1616 | lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); |
1617 | |
1618 | /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */ |
1619 | kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED); |
1620 | |
1621 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1622 | if (kick_dc) |
1623 | ocfs2_wake_downconvert_thread(osb); |
1624 | out: |
1625 | /* |
1626 | * This is helping work around a lock inversion between the page lock |
1627 | * and dlm locks. One path holds the page lock while calling aops |
1628 | * which block acquiring dlm locks. The voting thread holds dlm |
1629 | * locks while acquiring page locks while down converting data locks. |
1630 | * This block is helping an aop path notice the inversion and back |
1631 | * off to unlock its page lock before trying the dlm lock again. |
1632 | */ |
1633 | if (wait && arg_flags & OCFS2_LOCK_NONBLOCK && |
1634 | mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) { |
1635 | wait = 0; |
1636 | spin_lock_irqsave(&lockres->l_lock, flags); |
1637 | if (__lockres_remove_mask_waiter(lockres, mw: &mw)) { |
1638 | if (dlm_locked) |
1639 | lockres_or_flags(lockres, |
1640 | OCFS2_LOCK_NONBLOCK_FINISHED); |
1641 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1642 | ret = -EAGAIN; |
1643 | } else { |
1644 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1645 | goto again; |
1646 | } |
1647 | } |
1648 | if (wait) { |
1649 | ret = ocfs2_wait_for_mask(mw: &mw); |
1650 | if (ret == 0) |
1651 | goto again; |
1652 | mlog_errno(ret); |
1653 | } |
1654 | ocfs2_update_lock_stats(res: lockres, level, mw: &mw, ret); |
1655 | |
1656 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
1657 | if (!ret && lockres->l_lockdep_map.key != NULL) { |
1658 | if (level == DLM_LOCK_PR) |
1659 | rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass, |
1660 | !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), |
1661 | caller_ip); |
1662 | else |
1663 | rwsem_acquire(&lockres->l_lockdep_map, l_subclass, |
1664 | !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), |
1665 | caller_ip); |
1666 | } |
1667 | #endif |
1668 | return ret; |
1669 | } |
1670 | |
1671 | static inline int ocfs2_cluster_lock(struct ocfs2_super *osb, |
1672 | struct ocfs2_lock_res *lockres, |
1673 | int level, |
1674 | u32 lkm_flags, |
1675 | int arg_flags) |
1676 | { |
1677 | return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags, |
1678 | l_subclass: 0, _RET_IP_); |
1679 | } |
1680 | |
1681 | |
1682 | static void __ocfs2_cluster_unlock(struct ocfs2_super *osb, |
1683 | struct ocfs2_lock_res *lockres, |
1684 | int level, |
1685 | unsigned long caller_ip) |
1686 | { |
1687 | unsigned long flags; |
1688 | |
1689 | spin_lock_irqsave(&lockres->l_lock, flags); |
1690 | ocfs2_dec_holders(lockres, level); |
1691 | ocfs2_downconvert_on_unlock(osb, lockres); |
1692 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1693 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
1694 | if (lockres->l_lockdep_map.key != NULL) |
1695 | rwsem_release(&lockres->l_lockdep_map, caller_ip); |
1696 | #endif |
1697 | } |
1698 | |
1699 | static int ocfs2_create_new_lock(struct ocfs2_super *osb, |
1700 | struct ocfs2_lock_res *lockres, |
1701 | int ex, |
1702 | int local) |
1703 | { |
1704 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
1705 | unsigned long flags; |
1706 | u32 lkm_flags = local ? DLM_LKF_LOCAL : 0; |
1707 | |
1708 | spin_lock_irqsave(&lockres->l_lock, flags); |
1709 | BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); |
1710 | lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); |
1711 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1712 | |
1713 | return ocfs2_lock_create(osb, lockres, level, dlm_flags: lkm_flags); |
1714 | } |
1715 | |
1716 | /* Grants us an EX lock on the data and metadata resources, skipping |
1717 | * the normal cluster directory lookup. Use this ONLY on newly created |
1718 | * inodes which other nodes can't possibly see, and which haven't been |
1719 | * hashed in the inode hash yet. This can give us a good performance |
1720 | * increase as it'll skip the network broadcast normally associated |
1721 | * with creating a new lock resource. */ |
1722 | int ocfs2_create_new_inode_locks(struct inode *inode) |
1723 | { |
1724 | int ret; |
1725 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1726 | |
1727 | BUG_ON(!ocfs2_inode_is_new(inode)); |
1728 | |
1729 | mlog(0, "Inode %llu\n" , (unsigned long long)OCFS2_I(inode)->ip_blkno); |
1730 | |
1731 | /* NOTE: That we don't increment any of the holder counts, nor |
1732 | * do we add anything to a journal handle. Since this is |
1733 | * supposed to be a new inode which the cluster doesn't know |
1734 | * about yet, there is no need to. As far as the LVB handling |
1735 | * is concerned, this is basically like acquiring an EX lock |
1736 | * on a resource which has an invalid one -- we'll set it |
1737 | * valid when we release the EX. */ |
1738 | |
1739 | ret = ocfs2_create_new_lock(osb, lockres: &OCFS2_I(inode)->ip_rw_lockres, ex: 1, local: 1); |
1740 | if (ret) { |
1741 | mlog_errno(ret); |
1742 | goto bail; |
1743 | } |
1744 | |
1745 | /* |
1746 | * We don't want to use DLM_LKF_LOCAL on a meta data lock as they |
1747 | * don't use a generation in their lock names. |
1748 | */ |
1749 | ret = ocfs2_create_new_lock(osb, lockres: &OCFS2_I(inode)->ip_inode_lockres, ex: 1, local: 0); |
1750 | if (ret) { |
1751 | mlog_errno(ret); |
1752 | goto bail; |
1753 | } |
1754 | |
1755 | ret = ocfs2_create_new_lock(osb, lockres: &OCFS2_I(inode)->ip_open_lockres, ex: 0, local: 0); |
1756 | if (ret) |
1757 | mlog_errno(ret); |
1758 | |
1759 | bail: |
1760 | return ret; |
1761 | } |
1762 | |
1763 | int ocfs2_rw_lock(struct inode *inode, int write) |
1764 | { |
1765 | int status, level; |
1766 | struct ocfs2_lock_res *lockres; |
1767 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1768 | |
1769 | mlog(0, "inode %llu take %s RW lock\n" , |
1770 | (unsigned long long)OCFS2_I(inode)->ip_blkno, |
1771 | write ? "EXMODE" : "PRMODE" ); |
1772 | |
1773 | if (ocfs2_mount_local(osb)) |
1774 | return 0; |
1775 | |
1776 | lockres = &OCFS2_I(inode)->ip_rw_lockres; |
1777 | |
1778 | level = write ? DLM_LOCK_EX : DLM_LOCK_PR; |
1779 | |
1780 | status = ocfs2_cluster_lock(osb, lockres, level, lkm_flags: 0, arg_flags: 0); |
1781 | if (status < 0) |
1782 | mlog_errno(status); |
1783 | |
1784 | return status; |
1785 | } |
1786 | |
1787 | int ocfs2_try_rw_lock(struct inode *inode, int write) |
1788 | { |
1789 | int status, level; |
1790 | struct ocfs2_lock_res *lockres; |
1791 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1792 | |
1793 | mlog(0, "inode %llu try to take %s RW lock\n" , |
1794 | (unsigned long long)OCFS2_I(inode)->ip_blkno, |
1795 | write ? "EXMODE" : "PRMODE" ); |
1796 | |
1797 | if (ocfs2_mount_local(osb)) |
1798 | return 0; |
1799 | |
1800 | lockres = &OCFS2_I(inode)->ip_rw_lockres; |
1801 | |
1802 | level = write ? DLM_LOCK_EX : DLM_LOCK_PR; |
1803 | |
1804 | status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, arg_flags: 0); |
1805 | return status; |
1806 | } |
1807 | |
1808 | void ocfs2_rw_unlock(struct inode *inode, int write) |
1809 | { |
1810 | int level = write ? DLM_LOCK_EX : DLM_LOCK_PR; |
1811 | struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres; |
1812 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1813 | |
1814 | mlog(0, "inode %llu drop %s RW lock\n" , |
1815 | (unsigned long long)OCFS2_I(inode)->ip_blkno, |
1816 | write ? "EXMODE" : "PRMODE" ); |
1817 | |
1818 | if (!ocfs2_mount_local(osb)) |
1819 | ocfs2_cluster_unlock(osb, lockres, level); |
1820 | } |
1821 | |
1822 | /* |
1823 | * ocfs2_open_lock always get PR mode lock. |
1824 | */ |
1825 | int ocfs2_open_lock(struct inode *inode) |
1826 | { |
1827 | int status = 0; |
1828 | struct ocfs2_lock_res *lockres; |
1829 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1830 | |
1831 | mlog(0, "inode %llu take PRMODE open lock\n" , |
1832 | (unsigned long long)OCFS2_I(inode)->ip_blkno); |
1833 | |
1834 | if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb)) |
1835 | goto out; |
1836 | |
1837 | lockres = &OCFS2_I(inode)->ip_open_lockres; |
1838 | |
1839 | status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_PR, lkm_flags: 0, arg_flags: 0); |
1840 | if (status < 0) |
1841 | mlog_errno(status); |
1842 | |
1843 | out: |
1844 | return status; |
1845 | } |
1846 | |
1847 | int ocfs2_try_open_lock(struct inode *inode, int write) |
1848 | { |
1849 | int status = 0, level; |
1850 | struct ocfs2_lock_res *lockres; |
1851 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1852 | |
1853 | mlog(0, "inode %llu try to take %s open lock\n" , |
1854 | (unsigned long long)OCFS2_I(inode)->ip_blkno, |
1855 | write ? "EXMODE" : "PRMODE" ); |
1856 | |
1857 | if (ocfs2_is_hard_readonly(osb)) { |
1858 | if (write) |
1859 | status = -EROFS; |
1860 | goto out; |
1861 | } |
1862 | |
1863 | if (ocfs2_mount_local(osb)) |
1864 | goto out; |
1865 | |
1866 | lockres = &OCFS2_I(inode)->ip_open_lockres; |
1867 | |
1868 | level = write ? DLM_LOCK_EX : DLM_LOCK_PR; |
1869 | |
1870 | /* |
1871 | * The file system may already holding a PRMODE/EXMODE open lock. |
1872 | * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on |
1873 | * other nodes and the -EAGAIN will indicate to the caller that |
1874 | * this inode is still in use. |
1875 | */ |
1876 | status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, arg_flags: 0); |
1877 | |
1878 | out: |
1879 | return status; |
1880 | } |
1881 | |
1882 | /* |
1883 | * ocfs2_open_unlock unlock PR and EX mode open locks. |
1884 | */ |
1885 | void ocfs2_open_unlock(struct inode *inode) |
1886 | { |
1887 | struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres; |
1888 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
1889 | |
1890 | mlog(0, "inode %llu drop open lock\n" , |
1891 | (unsigned long long)OCFS2_I(inode)->ip_blkno); |
1892 | |
1893 | if (ocfs2_mount_local(osb)) |
1894 | goto out; |
1895 | |
1896 | if(lockres->l_ro_holders) |
1897 | ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_PR); |
1898 | if(lockres->l_ex_holders) |
1899 | ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); |
1900 | |
1901 | out: |
1902 | return; |
1903 | } |
1904 | |
1905 | static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres, |
1906 | int level) |
1907 | { |
1908 | int ret; |
1909 | struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); |
1910 | unsigned long flags; |
1911 | struct ocfs2_mask_waiter mw; |
1912 | |
1913 | ocfs2_init_mask_waiter(mw: &mw); |
1914 | |
1915 | retry_cancel: |
1916 | spin_lock_irqsave(&lockres->l_lock, flags); |
1917 | if (lockres->l_flags & OCFS2_LOCK_BUSY) { |
1918 | ret = ocfs2_prepare_cancel_convert(osb, lockres); |
1919 | if (ret) { |
1920 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1921 | ret = ocfs2_cancel_convert(osb, lockres); |
1922 | if (ret < 0) { |
1923 | mlog_errno(ret); |
1924 | goto out; |
1925 | } |
1926 | goto retry_cancel; |
1927 | } |
1928 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_BUSY, goal: 0); |
1929 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1930 | |
1931 | ocfs2_wait_for_mask(mw: &mw); |
1932 | goto retry_cancel; |
1933 | } |
1934 | |
1935 | ret = -ERESTARTSYS; |
1936 | /* |
1937 | * We may still have gotten the lock, in which case there's no |
1938 | * point to restarting the syscall. |
1939 | */ |
1940 | if (lockres->l_level == level) |
1941 | ret = 0; |
1942 | |
1943 | mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n" , ret, |
1944 | lockres->l_flags, lockres->l_level, lockres->l_action); |
1945 | |
1946 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1947 | |
1948 | out: |
1949 | return ret; |
1950 | } |
1951 | |
1952 | /* |
1953 | * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of |
1954 | * flock() calls. The locking approach this requires is sufficiently |
1955 | * different from all other cluster lock types that we implement a |
1956 | * separate path to the "low-level" dlm calls. In particular: |
1957 | * |
1958 | * - No optimization of lock levels is done - we take at exactly |
1959 | * what's been requested. |
1960 | * |
1961 | * - No lock caching is employed. We immediately downconvert to |
1962 | * no-lock at unlock time. This also means flock locks never go on |
1963 | * the blocking list). |
1964 | * |
1965 | * - Since userspace can trivially deadlock itself with flock, we make |
1966 | * sure to allow cancellation of a misbehaving applications flock() |
1967 | * request. |
1968 | * |
1969 | * - Access to any flock lockres doesn't require concurrency, so we |
1970 | * can simplify the code by requiring the caller to guarantee |
1971 | * serialization of dlmglue flock calls. |
1972 | */ |
1973 | int ocfs2_file_lock(struct file *file, int ex, int trylock) |
1974 | { |
1975 | int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
1976 | unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0; |
1977 | unsigned long flags; |
1978 | struct ocfs2_file_private *fp = file->private_data; |
1979 | struct ocfs2_lock_res *lockres = &fp->fp_flock; |
1980 | struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb); |
1981 | struct ocfs2_mask_waiter mw; |
1982 | |
1983 | ocfs2_init_mask_waiter(mw: &mw); |
1984 | |
1985 | if ((lockres->l_flags & OCFS2_LOCK_BUSY) || |
1986 | (lockres->l_level > DLM_LOCK_NL)) { |
1987 | mlog(ML_ERROR, |
1988 | "File lock \"%s\" has busy or locked state: flags: 0x%lx, " |
1989 | "level: %u\n" , lockres->l_name, lockres->l_flags, |
1990 | lockres->l_level); |
1991 | return -EINVAL; |
1992 | } |
1993 | |
1994 | spin_lock_irqsave(&lockres->l_lock, flags); |
1995 | if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { |
1996 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_BUSY, goal: 0); |
1997 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
1998 | |
1999 | /* |
2000 | * Get the lock at NLMODE to start - that way we |
2001 | * can cancel the upconvert request if need be. |
2002 | */ |
2003 | ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, dlm_flags: 0); |
2004 | if (ret < 0) { |
2005 | mlog_errno(ret); |
2006 | goto out; |
2007 | } |
2008 | |
2009 | ret = ocfs2_wait_for_mask(mw: &mw); |
2010 | if (ret) { |
2011 | mlog_errno(ret); |
2012 | goto out; |
2013 | } |
2014 | spin_lock_irqsave(&lockres->l_lock, flags); |
2015 | } |
2016 | |
2017 | lockres->l_action = OCFS2_AST_CONVERT; |
2018 | lkm_flags |= DLM_LKF_CONVERT; |
2019 | lockres->l_requested = level; |
2020 | lockres_or_flags(lockres, OCFS2_LOCK_BUSY); |
2021 | |
2022 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_BUSY, goal: 0); |
2023 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
2024 | |
2025 | ret = ocfs2_dlm_lock(conn: osb->cconn, mode: level, lksb: &lockres->l_lksb, flags: lkm_flags, |
2026 | name: lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1); |
2027 | if (ret) { |
2028 | if (!trylock || (ret != -EAGAIN)) { |
2029 | ocfs2_log_dlm_error("ocfs2_dlm_lock" , ret, lockres); |
2030 | ret = -EINVAL; |
2031 | } |
2032 | |
2033 | ocfs2_recover_from_dlm_error(lockres, convert: 1); |
2034 | lockres_remove_mask_waiter(lockres, mw: &mw); |
2035 | goto out; |
2036 | } |
2037 | |
2038 | ret = ocfs2_wait_for_mask_interruptible(mw: &mw, lockres); |
2039 | if (ret == -ERESTARTSYS) { |
2040 | /* |
2041 | * Userspace can cause deadlock itself with |
2042 | * flock(). Current behavior locally is to allow the |
2043 | * deadlock, but abort the system call if a signal is |
2044 | * received. We follow this example, otherwise a |
2045 | * poorly written program could sit in kernel until |
2046 | * reboot. |
2047 | * |
2048 | * Handling this is a bit more complicated for Ocfs2 |
2049 | * though. We can't exit this function with an |
2050 | * outstanding lock request, so a cancel convert is |
2051 | * required. We intentionally overwrite 'ret' - if the |
2052 | * cancel fails and the lock was granted, it's easier |
2053 | * to just bubble success back up to the user. |
2054 | */ |
2055 | ret = ocfs2_flock_handle_signal(lockres, level); |
2056 | } else if (!ret && (level > lockres->l_level)) { |
2057 | /* Trylock failed asynchronously */ |
2058 | BUG_ON(!trylock); |
2059 | ret = -EAGAIN; |
2060 | } |
2061 | |
2062 | out: |
2063 | |
2064 | mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n" , |
2065 | lockres->l_name, ex, trylock, ret); |
2066 | return ret; |
2067 | } |
2068 | |
2069 | void ocfs2_file_unlock(struct file *file) |
2070 | { |
2071 | int ret; |
2072 | unsigned int gen; |
2073 | unsigned long flags; |
2074 | struct ocfs2_file_private *fp = file->private_data; |
2075 | struct ocfs2_lock_res *lockres = &fp->fp_flock; |
2076 | struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb); |
2077 | struct ocfs2_mask_waiter mw; |
2078 | |
2079 | ocfs2_init_mask_waiter(mw: &mw); |
2080 | |
2081 | if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) |
2082 | return; |
2083 | |
2084 | if (lockres->l_level == DLM_LOCK_NL) |
2085 | return; |
2086 | |
2087 | mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n" , |
2088 | lockres->l_name, lockres->l_flags, lockres->l_level, |
2089 | lockres->l_action); |
2090 | |
2091 | spin_lock_irqsave(&lockres->l_lock, flags); |
2092 | /* |
2093 | * Fake a blocking ast for the downconvert code. |
2094 | */ |
2095 | lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); |
2096 | lockres->l_blocking = DLM_LOCK_EX; |
2097 | |
2098 | gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL); |
2099 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_BUSY, goal: 0); |
2100 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
2101 | |
2102 | ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, lvb: 0, generation: gen); |
2103 | if (ret) { |
2104 | mlog_errno(ret); |
2105 | return; |
2106 | } |
2107 | |
2108 | ret = ocfs2_wait_for_mask(mw: &mw); |
2109 | if (ret) |
2110 | mlog_errno(ret); |
2111 | } |
2112 | |
2113 | static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb, |
2114 | struct ocfs2_lock_res *lockres) |
2115 | { |
2116 | int kick = 0; |
2117 | |
2118 | /* If we know that another node is waiting on our lock, kick |
2119 | * the downconvert thread * pre-emptively when we reach a release |
2120 | * condition. */ |
2121 | if (lockres->l_flags & OCFS2_LOCK_BLOCKED) { |
2122 | switch(lockres->l_blocking) { |
2123 | case DLM_LOCK_EX: |
2124 | if (!lockres->l_ex_holders && !lockres->l_ro_holders) |
2125 | kick = 1; |
2126 | break; |
2127 | case DLM_LOCK_PR: |
2128 | if (!lockres->l_ex_holders) |
2129 | kick = 1; |
2130 | break; |
2131 | default: |
2132 | BUG(); |
2133 | } |
2134 | } |
2135 | |
2136 | if (kick) |
2137 | ocfs2_wake_downconvert_thread(osb); |
2138 | } |
2139 | |
2140 | #define OCFS2_SEC_BITS 34 |
2141 | #define OCFS2_SEC_SHIFT (64 - OCFS2_SEC_BITS) |
2142 | #define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1) |
2143 | |
2144 | /* LVB only has room for 64 bits of time here so we pack it for |
2145 | * now. */ |
2146 | static u64 ocfs2_pack_timespec(struct timespec64 *spec) |
2147 | { |
2148 | u64 res; |
2149 | u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull); |
2150 | u32 nsec = spec->tv_nsec; |
2151 | |
2152 | res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK); |
2153 | |
2154 | return res; |
2155 | } |
2156 | |
2157 | /* Call this with the lockres locked. I am reasonably sure we don't |
2158 | * need ip_lock in this function as anyone who would be changing those |
2159 | * values is supposed to be blocked in ocfs2_inode_lock right now. */ |
2160 | static void __ocfs2_stuff_meta_lvb(struct inode *inode) |
2161 | { |
2162 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
2163 | struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; |
2164 | struct ocfs2_meta_lvb *lvb; |
2165 | struct timespec64 ts; |
2166 | |
2167 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2168 | |
2169 | /* |
2170 | * Invalidate the LVB of a deleted inode - this way other |
2171 | * nodes are forced to go to disk and discover the new inode |
2172 | * status. |
2173 | */ |
2174 | if (oi->ip_flags & OCFS2_INODE_DELETED) { |
2175 | lvb->lvb_version = 0; |
2176 | goto out; |
2177 | } |
2178 | |
2179 | lvb->lvb_version = OCFS2_LVB_VERSION; |
2180 | lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); |
2181 | lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); |
2182 | lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode)); |
2183 | lvb->lvb_igid = cpu_to_be32(i_gid_read(inode)); |
2184 | lvb->lvb_imode = cpu_to_be16(inode->i_mode); |
2185 | lvb->lvb_inlink = cpu_to_be16(inode->i_nlink); |
2186 | ts = inode_get_atime(inode); |
2187 | lvb->lvb_iatime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts)); |
2188 | ts = inode_get_ctime(inode); |
2189 | lvb->lvb_ictime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts)); |
2190 | ts = inode_get_mtime(inode); |
2191 | lvb->lvb_imtime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts)); |
2192 | lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); |
2193 | lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features); |
2194 | lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); |
2195 | |
2196 | out: |
2197 | mlog_meta_lvb(0, lockres); |
2198 | } |
2199 | |
2200 | static void ocfs2_unpack_timespec(struct timespec64 *spec, |
2201 | u64 packed_time) |
2202 | { |
2203 | spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT; |
2204 | spec->tv_nsec = packed_time & OCFS2_NSEC_MASK; |
2205 | } |
2206 | |
2207 | static int ocfs2_refresh_inode_from_lvb(struct inode *inode) |
2208 | { |
2209 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
2210 | struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; |
2211 | struct ocfs2_meta_lvb *lvb; |
2212 | struct timespec64 ts; |
2213 | |
2214 | mlog_meta_lvb(0, lockres); |
2215 | |
2216 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2217 | if (inode_wrong_type(inode, be16_to_cpu(lvb->lvb_imode))) |
2218 | return -ESTALE; |
2219 | |
2220 | /* We're safe here without the lockres lock... */ |
2221 | spin_lock(lock: &oi->ip_lock); |
2222 | oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters); |
2223 | i_size_write(inode, be64_to_cpu(lvb->lvb_isize)); |
2224 | |
2225 | oi->ip_attr = be32_to_cpu(lvb->lvb_iattr); |
2226 | oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures); |
2227 | ocfs2_set_inode_flags(inode); |
2228 | |
2229 | /* fast-symlinks are a special case */ |
2230 | if (S_ISLNK(inode->i_mode) && !oi->ip_clusters) |
2231 | inode->i_blocks = 0; |
2232 | else |
2233 | inode->i_blocks = ocfs2_inode_sector_count(inode); |
2234 | |
2235 | i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid)); |
2236 | i_gid_write(inode, be32_to_cpu(lvb->lvb_igid)); |
2237 | inode->i_mode = be16_to_cpu(lvb->lvb_imode); |
2238 | set_nlink(inode, be16_to_cpu(lvb->lvb_inlink)); |
2239 | ocfs2_unpack_timespec(spec: &ts, be64_to_cpu(lvb->lvb_iatime_packed)); |
2240 | inode_set_atime_to_ts(inode, ts); |
2241 | ocfs2_unpack_timespec(spec: &ts, be64_to_cpu(lvb->lvb_imtime_packed)); |
2242 | inode_set_mtime_to_ts(inode, ts); |
2243 | ocfs2_unpack_timespec(spec: &ts, be64_to_cpu(lvb->lvb_ictime_packed)); |
2244 | inode_set_ctime_to_ts(inode, ts); |
2245 | spin_unlock(lock: &oi->ip_lock); |
2246 | return 0; |
2247 | } |
2248 | |
2249 | static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode, |
2250 | struct ocfs2_lock_res *lockres) |
2251 | { |
2252 | struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2253 | |
2254 | if (ocfs2_dlm_lvb_valid(lksb: &lockres->l_lksb) |
2255 | && lvb->lvb_version == OCFS2_LVB_VERSION |
2256 | && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation) |
2257 | return 1; |
2258 | return 0; |
2259 | } |
2260 | |
2261 | /* Determine whether a lock resource needs to be refreshed, and |
2262 | * arbitrate who gets to refresh it. |
2263 | * |
2264 | * 0 means no refresh needed. |
2265 | * |
2266 | * > 0 means you need to refresh this and you MUST call |
2267 | * ocfs2_complete_lock_res_refresh afterwards. */ |
2268 | static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres) |
2269 | { |
2270 | unsigned long flags; |
2271 | int status = 0; |
2272 | |
2273 | refresh_check: |
2274 | spin_lock_irqsave(&lockres->l_lock, flags); |
2275 | if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) { |
2276 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
2277 | goto bail; |
2278 | } |
2279 | |
2280 | if (lockres->l_flags & OCFS2_LOCK_REFRESHING) { |
2281 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
2282 | |
2283 | ocfs2_wait_on_refreshing_lock(lockres); |
2284 | goto refresh_check; |
2285 | } |
2286 | |
2287 | /* Ok, I'll be the one to refresh this lock. */ |
2288 | lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING); |
2289 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
2290 | |
2291 | status = 1; |
2292 | bail: |
2293 | mlog(0, "status %d\n" , status); |
2294 | return status; |
2295 | } |
2296 | |
2297 | /* If status is non zero, I'll mark it as not being in refresh |
2298 | * anymroe, but i won't clear the needs refresh flag. */ |
2299 | static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres, |
2300 | int status) |
2301 | { |
2302 | unsigned long flags; |
2303 | |
2304 | spin_lock_irqsave(&lockres->l_lock, flags); |
2305 | lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING); |
2306 | if (!status) |
2307 | lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); |
2308 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
2309 | |
2310 | wake_up(&lockres->l_event); |
2311 | } |
2312 | |
2313 | /* may or may not return a bh if it went to disk. */ |
2314 | static int ocfs2_inode_lock_update(struct inode *inode, |
2315 | struct buffer_head **bh) |
2316 | { |
2317 | int status = 0; |
2318 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
2319 | struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; |
2320 | struct ocfs2_dinode *fe; |
2321 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
2322 | |
2323 | if (ocfs2_mount_local(osb)) |
2324 | goto bail; |
2325 | |
2326 | spin_lock(lock: &oi->ip_lock); |
2327 | if (oi->ip_flags & OCFS2_INODE_DELETED) { |
2328 | mlog(0, "Orphaned inode %llu was deleted while we " |
2329 | "were waiting on a lock. ip_flags = 0x%x\n" , |
2330 | (unsigned long long)oi->ip_blkno, oi->ip_flags); |
2331 | spin_unlock(lock: &oi->ip_lock); |
2332 | status = -ENOENT; |
2333 | goto bail; |
2334 | } |
2335 | spin_unlock(lock: &oi->ip_lock); |
2336 | |
2337 | if (!ocfs2_should_refresh_lock_res(lockres)) |
2338 | goto bail; |
2339 | |
2340 | /* This will discard any caching information we might have had |
2341 | * for the inode metadata. */ |
2342 | ocfs2_metadata_cache_purge(ci: INODE_CACHE(inode)); |
2343 | |
2344 | ocfs2_extent_map_trunc(inode, cluster: 0); |
2345 | |
2346 | if (ocfs2_meta_lvb_is_trustable(inode, lockres)) { |
2347 | mlog(0, "Trusting LVB on inode %llu\n" , |
2348 | (unsigned long long)oi->ip_blkno); |
2349 | status = ocfs2_refresh_inode_from_lvb(inode); |
2350 | goto bail_refresh; |
2351 | } else { |
2352 | /* Boo, we have to go to disk. */ |
2353 | /* read bh, cast, ocfs2_refresh_inode */ |
2354 | status = ocfs2_read_inode_block(inode, bh); |
2355 | if (status < 0) { |
2356 | mlog_errno(status); |
2357 | goto bail_refresh; |
2358 | } |
2359 | fe = (struct ocfs2_dinode *) (*bh)->b_data; |
2360 | if (inode_wrong_type(inode, le16_to_cpu(fe->i_mode))) { |
2361 | status = -ESTALE; |
2362 | goto bail_refresh; |
2363 | } |
2364 | |
2365 | /* This is a good chance to make sure we're not |
2366 | * locking an invalid object. ocfs2_read_inode_block() |
2367 | * already checked that the inode block is sane. |
2368 | * |
2369 | * We bug on a stale inode here because we checked |
2370 | * above whether it was wiped from disk. The wiping |
2371 | * node provides a guarantee that we receive that |
2372 | * message and can mark the inode before dropping any |
2373 | * locks associated with it. */ |
2374 | mlog_bug_on_msg(inode->i_generation != |
2375 | le32_to_cpu(fe->i_generation), |
2376 | "Invalid dinode %llu disk generation: %u " |
2377 | "inode->i_generation: %u\n" , |
2378 | (unsigned long long)oi->ip_blkno, |
2379 | le32_to_cpu(fe->i_generation), |
2380 | inode->i_generation); |
2381 | mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) || |
2382 | !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)), |
2383 | "Stale dinode %llu dtime: %llu flags: 0x%x\n" , |
2384 | (unsigned long long)oi->ip_blkno, |
2385 | (unsigned long long)le64_to_cpu(fe->i_dtime), |
2386 | le32_to_cpu(fe->i_flags)); |
2387 | |
2388 | ocfs2_refresh_inode(inode, fe); |
2389 | ocfs2_track_lock_refresh(lockres); |
2390 | } |
2391 | |
2392 | status = 0; |
2393 | bail_refresh: |
2394 | ocfs2_complete_lock_res_refresh(lockres, status); |
2395 | bail: |
2396 | return status; |
2397 | } |
2398 | |
2399 | static int ocfs2_assign_bh(struct inode *inode, |
2400 | struct buffer_head **ret_bh, |
2401 | struct buffer_head *passed_bh) |
2402 | { |
2403 | int status; |
2404 | |
2405 | if (passed_bh) { |
2406 | /* Ok, the update went to disk for us, use the |
2407 | * returned bh. */ |
2408 | *ret_bh = passed_bh; |
2409 | get_bh(bh: *ret_bh); |
2410 | |
2411 | return 0; |
2412 | } |
2413 | |
2414 | status = ocfs2_read_inode_block(inode, bh: ret_bh); |
2415 | if (status < 0) |
2416 | mlog_errno(status); |
2417 | |
2418 | return status; |
2419 | } |
2420 | |
2421 | /* |
2422 | * returns < 0 error if the callback will never be called, otherwise |
2423 | * the result of the lock will be communicated via the callback. |
2424 | */ |
2425 | int ocfs2_inode_lock_full_nested(struct inode *inode, |
2426 | struct buffer_head **ret_bh, |
2427 | int ex, |
2428 | int arg_flags, |
2429 | int subclass) |
2430 | { |
2431 | int status, level, acquired; |
2432 | u32 dlm_flags; |
2433 | struct ocfs2_lock_res *lockres = NULL; |
2434 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
2435 | struct buffer_head *local_bh = NULL; |
2436 | |
2437 | mlog(0, "inode %llu, take %s META lock\n" , |
2438 | (unsigned long long)OCFS2_I(inode)->ip_blkno, |
2439 | ex ? "EXMODE" : "PRMODE" ); |
2440 | |
2441 | status = 0; |
2442 | acquired = 0; |
2443 | /* We'll allow faking a readonly metadata lock for |
2444 | * rodevices. */ |
2445 | if (ocfs2_is_hard_readonly(osb)) { |
2446 | if (ex) |
2447 | status = -EROFS; |
2448 | goto getbh; |
2449 | } |
2450 | |
2451 | if ((arg_flags & OCFS2_META_LOCK_GETBH) || |
2452 | ocfs2_mount_local(osb)) |
2453 | goto update; |
2454 | |
2455 | if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) |
2456 | ocfs2_wait_for_recovery(osb); |
2457 | |
2458 | lockres = &OCFS2_I(inode)->ip_inode_lockres; |
2459 | level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
2460 | dlm_flags = 0; |
2461 | if (arg_flags & OCFS2_META_LOCK_NOQUEUE) |
2462 | dlm_flags |= DLM_LKF_NOQUEUE; |
2463 | |
2464 | status = __ocfs2_cluster_lock(osb, lockres, level, lkm_flags: dlm_flags, |
2465 | arg_flags, l_subclass: subclass, _RET_IP_); |
2466 | if (status < 0) { |
2467 | if (status != -EAGAIN) |
2468 | mlog_errno(status); |
2469 | goto bail; |
2470 | } |
2471 | |
2472 | /* Notify the error cleanup path to drop the cluster lock. */ |
2473 | acquired = 1; |
2474 | |
2475 | /* We wait twice because a node may have died while we were in |
2476 | * the lower dlm layers. The second time though, we've |
2477 | * committed to owning this lock so we don't allow signals to |
2478 | * abort the operation. */ |
2479 | if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) |
2480 | ocfs2_wait_for_recovery(osb); |
2481 | |
2482 | update: |
2483 | /* |
2484 | * We only see this flag if we're being called from |
2485 | * ocfs2_read_locked_inode(). It means we're locking an inode |
2486 | * which hasn't been populated yet, so clear the refresh flag |
2487 | * and let the caller handle it. |
2488 | */ |
2489 | if (inode->i_state & I_NEW) { |
2490 | status = 0; |
2491 | if (lockres) |
2492 | ocfs2_complete_lock_res_refresh(lockres, status: 0); |
2493 | goto bail; |
2494 | } |
2495 | |
2496 | /* This is fun. The caller may want a bh back, or it may |
2497 | * not. ocfs2_inode_lock_update definitely wants one in, but |
2498 | * may or may not read one, depending on what's in the |
2499 | * LVB. The result of all of this is that we've *only* gone to |
2500 | * disk if we have to, so the complexity is worthwhile. */ |
2501 | status = ocfs2_inode_lock_update(inode, bh: &local_bh); |
2502 | if (status < 0) { |
2503 | if (status != -ENOENT) |
2504 | mlog_errno(status); |
2505 | goto bail; |
2506 | } |
2507 | getbh: |
2508 | if (ret_bh) { |
2509 | status = ocfs2_assign_bh(inode, ret_bh, passed_bh: local_bh); |
2510 | if (status < 0) { |
2511 | mlog_errno(status); |
2512 | goto bail; |
2513 | } |
2514 | } |
2515 | |
2516 | bail: |
2517 | if (status < 0) { |
2518 | if (ret_bh && (*ret_bh)) { |
2519 | brelse(bh: *ret_bh); |
2520 | *ret_bh = NULL; |
2521 | } |
2522 | if (acquired) |
2523 | ocfs2_inode_unlock(inode, ex); |
2524 | } |
2525 | |
2526 | brelse(bh: local_bh); |
2527 | return status; |
2528 | } |
2529 | |
2530 | /* |
2531 | * This is working around a lock inversion between tasks acquiring DLM |
2532 | * locks while holding a page lock and the downconvert thread which |
2533 | * blocks dlm lock acquiry while acquiring page locks. |
2534 | * |
2535 | * ** These _with_page variantes are only intended to be called from aop |
2536 | * methods that hold page locks and return a very specific *positive* error |
2537 | * code that aop methods pass up to the VFS -- test for errors with != 0. ** |
2538 | * |
2539 | * The DLM is called such that it returns -EAGAIN if it would have |
2540 | * blocked waiting for the downconvert thread. In that case we unlock |
2541 | * our page so the downconvert thread can make progress. Once we've |
2542 | * done this we have to return AOP_TRUNCATED_PAGE so the aop method |
2543 | * that called us can bubble that back up into the VFS who will then |
2544 | * immediately retry the aop call. |
2545 | */ |
2546 | int ocfs2_inode_lock_with_page(struct inode *inode, |
2547 | struct buffer_head **ret_bh, |
2548 | int ex, |
2549 | struct page *page) |
2550 | { |
2551 | int ret; |
2552 | |
2553 | ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK); |
2554 | if (ret == -EAGAIN) { |
2555 | unlock_page(page); |
2556 | /* |
2557 | * If we can't get inode lock immediately, we should not return |
2558 | * directly here, since this will lead to a softlockup problem. |
2559 | * The method is to get a blocking lock and immediately unlock |
2560 | * before returning, this can avoid CPU resource waste due to |
2561 | * lots of retries, and benefits fairness in getting lock. |
2562 | */ |
2563 | if (ocfs2_inode_lock(inode, ret_bh, ex) == 0) |
2564 | ocfs2_inode_unlock(inode, ex); |
2565 | ret = AOP_TRUNCATED_PAGE; |
2566 | } |
2567 | |
2568 | return ret; |
2569 | } |
2570 | |
2571 | int ocfs2_inode_lock_atime(struct inode *inode, |
2572 | struct vfsmount *vfsmnt, |
2573 | int *level, int wait) |
2574 | { |
2575 | int ret; |
2576 | |
2577 | if (wait) |
2578 | ret = ocfs2_inode_lock(inode, NULL, 0); |
2579 | else |
2580 | ret = ocfs2_try_inode_lock(inode, NULL, 0); |
2581 | |
2582 | if (ret < 0) { |
2583 | if (ret != -EAGAIN) |
2584 | mlog_errno(ret); |
2585 | return ret; |
2586 | } |
2587 | |
2588 | /* |
2589 | * If we should update atime, we will get EX lock, |
2590 | * otherwise we just get PR lock. |
2591 | */ |
2592 | if (ocfs2_should_update_atime(inode, vfsmnt)) { |
2593 | struct buffer_head *bh = NULL; |
2594 | |
2595 | ocfs2_inode_unlock(inode, ex: 0); |
2596 | if (wait) |
2597 | ret = ocfs2_inode_lock(inode, &bh, 1); |
2598 | else |
2599 | ret = ocfs2_try_inode_lock(inode, &bh, 1); |
2600 | |
2601 | if (ret < 0) { |
2602 | if (ret != -EAGAIN) |
2603 | mlog_errno(ret); |
2604 | return ret; |
2605 | } |
2606 | *level = 1; |
2607 | if (ocfs2_should_update_atime(inode, vfsmnt)) |
2608 | ocfs2_update_inode_atime(inode, bh); |
2609 | brelse(bh); |
2610 | } else |
2611 | *level = 0; |
2612 | |
2613 | return ret; |
2614 | } |
2615 | |
2616 | void ocfs2_inode_unlock(struct inode *inode, |
2617 | int ex) |
2618 | { |
2619 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
2620 | struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres; |
2621 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); |
2622 | |
2623 | mlog(0, "inode %llu drop %s META lock\n" , |
2624 | (unsigned long long)OCFS2_I(inode)->ip_blkno, |
2625 | ex ? "EXMODE" : "PRMODE" ); |
2626 | |
2627 | if (!ocfs2_is_hard_readonly(osb) && |
2628 | !ocfs2_mount_local(osb)) |
2629 | ocfs2_cluster_unlock(osb, lockres, level); |
2630 | } |
2631 | |
2632 | /* |
2633 | * This _tracker variantes are introduced to deal with the recursive cluster |
2634 | * locking issue. The idea is to keep track of a lock holder on the stack of |
2635 | * the current process. If there's a lock holder on the stack, we know the |
2636 | * task context is already protected by cluster locking. Currently, they're |
2637 | * used in some VFS entry routines. |
2638 | * |
2639 | * return < 0 on error, return == 0 if there's no lock holder on the stack |
2640 | * before this call, return == 1 if this call would be a recursive locking. |
2641 | * return == -1 if this lock attempt will cause an upgrade which is forbidden. |
2642 | * |
2643 | * When taking lock levels into account,we face some different situations. |
2644 | * |
2645 | * 1. no lock is held |
2646 | * In this case, just lock the inode as requested and return 0 |
2647 | * |
2648 | * 2. We are holding a lock |
2649 | * For this situation, things diverges into several cases |
2650 | * |
2651 | * wanted holding what to do |
2652 | * ex ex see 2.1 below |
2653 | * ex pr see 2.2 below |
2654 | * pr ex see 2.1 below |
2655 | * pr pr see 2.1 below |
2656 | * |
2657 | * 2.1 lock level that is been held is compatible |
2658 | * with the wanted level, so no lock action will be tacken. |
2659 | * |
2660 | * 2.2 Otherwise, an upgrade is needed, but it is forbidden. |
2661 | * |
2662 | * Reason why upgrade within a process is forbidden is that |
2663 | * lock upgrade may cause dead lock. The following illustrates |
2664 | * how it happens. |
2665 | * |
2666 | * thread on node1 thread on node2 |
2667 | * ocfs2_inode_lock_tracker(ex=0) |
2668 | * |
2669 | * <====== ocfs2_inode_lock_tracker(ex=1) |
2670 | * |
2671 | * ocfs2_inode_lock_tracker(ex=1) |
2672 | */ |
2673 | int ocfs2_inode_lock_tracker(struct inode *inode, |
2674 | struct buffer_head **ret_bh, |
2675 | int ex, |
2676 | struct ocfs2_lock_holder *oh) |
2677 | { |
2678 | int status = 0; |
2679 | struct ocfs2_lock_res *lockres; |
2680 | struct ocfs2_lock_holder *tmp_oh; |
2681 | struct pid *pid = task_pid(current); |
2682 | |
2683 | |
2684 | lockres = &OCFS2_I(inode)->ip_inode_lockres; |
2685 | tmp_oh = ocfs2_pid_holder(lockres, pid); |
2686 | |
2687 | if (!tmp_oh) { |
2688 | /* |
2689 | * This corresponds to the case 1. |
2690 | * We haven't got any lock before. |
2691 | */ |
2692 | status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0); |
2693 | if (status < 0) { |
2694 | if (status != -ENOENT) |
2695 | mlog_errno(status); |
2696 | return status; |
2697 | } |
2698 | |
2699 | oh->oh_ex = ex; |
2700 | ocfs2_add_holder(lockres, oh); |
2701 | return 0; |
2702 | } |
2703 | |
2704 | if (unlikely(ex && !tmp_oh->oh_ex)) { |
2705 | /* |
2706 | * case 2.2 upgrade may cause dead lock, forbid it. |
2707 | */ |
2708 | mlog(ML_ERROR, "Recursive locking is not permitted to " |
2709 | "upgrade to EX level from PR level.\n" ); |
2710 | dump_stack(); |
2711 | return -EINVAL; |
2712 | } |
2713 | |
2714 | /* |
2715 | * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full. |
2716 | * ignore the lock level and just update it. |
2717 | */ |
2718 | if (ret_bh) { |
2719 | status = ocfs2_inode_lock_full(inode, ret_bh, ex, |
2720 | OCFS2_META_LOCK_GETBH); |
2721 | if (status < 0) { |
2722 | if (status != -ENOENT) |
2723 | mlog_errno(status); |
2724 | return status; |
2725 | } |
2726 | } |
2727 | return 1; |
2728 | } |
2729 | |
2730 | void ocfs2_inode_unlock_tracker(struct inode *inode, |
2731 | int ex, |
2732 | struct ocfs2_lock_holder *oh, |
2733 | int had_lock) |
2734 | { |
2735 | struct ocfs2_lock_res *lockres; |
2736 | |
2737 | lockres = &OCFS2_I(inode)->ip_inode_lockres; |
2738 | /* had_lock means that the currect process already takes the cluster |
2739 | * lock previously. |
2740 | * If had_lock is 1, we have nothing to do here. |
2741 | * If had_lock is 0, we will release the lock. |
2742 | */ |
2743 | if (!had_lock) { |
2744 | ocfs2_inode_unlock(inode, ex: oh->oh_ex); |
2745 | ocfs2_remove_holder(lockres, oh); |
2746 | } |
2747 | } |
2748 | |
2749 | int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno) |
2750 | { |
2751 | struct ocfs2_lock_res *lockres; |
2752 | struct ocfs2_orphan_scan_lvb *lvb; |
2753 | int status = 0; |
2754 | |
2755 | if (ocfs2_is_hard_readonly(osb)) |
2756 | return -EROFS; |
2757 | |
2758 | if (ocfs2_mount_local(osb)) |
2759 | return 0; |
2760 | |
2761 | lockres = &osb->osb_orphan_scan.os_lockres; |
2762 | status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, lkm_flags: 0, arg_flags: 0); |
2763 | if (status < 0) |
2764 | return status; |
2765 | |
2766 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2767 | if (ocfs2_dlm_lvb_valid(lksb: &lockres->l_lksb) && |
2768 | lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION) |
2769 | *seqno = be32_to_cpu(lvb->lvb_os_seqno); |
2770 | else |
2771 | *seqno = osb->osb_orphan_scan.os_seqno + 1; |
2772 | |
2773 | return status; |
2774 | } |
2775 | |
2776 | void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno) |
2777 | { |
2778 | struct ocfs2_lock_res *lockres; |
2779 | struct ocfs2_orphan_scan_lvb *lvb; |
2780 | |
2781 | if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) { |
2782 | lockres = &osb->osb_orphan_scan.os_lockres; |
2783 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2784 | lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION; |
2785 | lvb->lvb_os_seqno = cpu_to_be32(seqno); |
2786 | ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); |
2787 | } |
2788 | } |
2789 | |
2790 | int ocfs2_super_lock(struct ocfs2_super *osb, |
2791 | int ex) |
2792 | { |
2793 | int status = 0; |
2794 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
2795 | struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; |
2796 | |
2797 | if (ocfs2_is_hard_readonly(osb)) |
2798 | return -EROFS; |
2799 | |
2800 | if (ocfs2_mount_local(osb)) |
2801 | goto bail; |
2802 | |
2803 | status = ocfs2_cluster_lock(osb, lockres, level, lkm_flags: 0, arg_flags: 0); |
2804 | if (status < 0) { |
2805 | mlog_errno(status); |
2806 | goto bail; |
2807 | } |
2808 | |
2809 | /* The super block lock path is really in the best position to |
2810 | * know when resources covered by the lock need to be |
2811 | * refreshed, so we do it here. Of course, making sense of |
2812 | * everything is up to the caller :) */ |
2813 | status = ocfs2_should_refresh_lock_res(lockres); |
2814 | if (status) { |
2815 | status = ocfs2_refresh_slot_info(osb); |
2816 | |
2817 | ocfs2_complete_lock_res_refresh(lockres, status); |
2818 | |
2819 | if (status < 0) { |
2820 | ocfs2_cluster_unlock(osb, lockres, level); |
2821 | mlog_errno(status); |
2822 | } |
2823 | ocfs2_track_lock_refresh(lockres); |
2824 | } |
2825 | bail: |
2826 | return status; |
2827 | } |
2828 | |
2829 | void ocfs2_super_unlock(struct ocfs2_super *osb, |
2830 | int ex) |
2831 | { |
2832 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
2833 | struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; |
2834 | |
2835 | if (!ocfs2_mount_local(osb)) |
2836 | ocfs2_cluster_unlock(osb, lockres, level); |
2837 | } |
2838 | |
2839 | int ocfs2_rename_lock(struct ocfs2_super *osb) |
2840 | { |
2841 | int status; |
2842 | struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; |
2843 | |
2844 | if (ocfs2_is_hard_readonly(osb)) |
2845 | return -EROFS; |
2846 | |
2847 | if (ocfs2_mount_local(osb)) |
2848 | return 0; |
2849 | |
2850 | status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, lkm_flags: 0, arg_flags: 0); |
2851 | if (status < 0) |
2852 | mlog_errno(status); |
2853 | |
2854 | return status; |
2855 | } |
2856 | |
2857 | void ocfs2_rename_unlock(struct ocfs2_super *osb) |
2858 | { |
2859 | struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; |
2860 | |
2861 | if (!ocfs2_mount_local(osb)) |
2862 | ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); |
2863 | } |
2864 | |
2865 | int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex) |
2866 | { |
2867 | int status; |
2868 | struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; |
2869 | |
2870 | if (ocfs2_is_hard_readonly(osb)) |
2871 | return -EROFS; |
2872 | |
2873 | if (ex) |
2874 | down_write(sem: &osb->nfs_sync_rwlock); |
2875 | else |
2876 | down_read(sem: &osb->nfs_sync_rwlock); |
2877 | |
2878 | if (ocfs2_mount_local(osb)) |
2879 | return 0; |
2880 | |
2881 | status = ocfs2_cluster_lock(osb, lockres, level: ex ? LKM_EXMODE : LKM_PRMODE, |
2882 | lkm_flags: 0, arg_flags: 0); |
2883 | if (status < 0) { |
2884 | mlog(ML_ERROR, "lock on nfs sync lock failed %d\n" , status); |
2885 | |
2886 | if (ex) |
2887 | up_write(sem: &osb->nfs_sync_rwlock); |
2888 | else |
2889 | up_read(sem: &osb->nfs_sync_rwlock); |
2890 | } |
2891 | |
2892 | return status; |
2893 | } |
2894 | |
2895 | void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex) |
2896 | { |
2897 | struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; |
2898 | |
2899 | if (!ocfs2_mount_local(osb)) |
2900 | ocfs2_cluster_unlock(osb, lockres, |
2901 | level: ex ? LKM_EXMODE : LKM_PRMODE); |
2902 | if (ex) |
2903 | up_write(sem: &osb->nfs_sync_rwlock); |
2904 | else |
2905 | up_read(sem: &osb->nfs_sync_rwlock); |
2906 | } |
2907 | |
2908 | int ocfs2_trim_fs_lock(struct ocfs2_super *osb, |
2909 | struct ocfs2_trim_fs_info *info, int trylock) |
2910 | { |
2911 | int status; |
2912 | struct ocfs2_trim_fs_lvb *lvb; |
2913 | struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; |
2914 | |
2915 | if (info) |
2916 | info->tf_valid = 0; |
2917 | |
2918 | if (ocfs2_is_hard_readonly(osb)) |
2919 | return -EROFS; |
2920 | |
2921 | if (ocfs2_mount_local(osb)) |
2922 | return 0; |
2923 | |
2924 | status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, |
2925 | lkm_flags: trylock ? DLM_LKF_NOQUEUE : 0, arg_flags: 0); |
2926 | if (status < 0) { |
2927 | if (status != -EAGAIN) |
2928 | mlog_errno(status); |
2929 | return status; |
2930 | } |
2931 | |
2932 | if (info) { |
2933 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2934 | if (ocfs2_dlm_lvb_valid(lksb: &lockres->l_lksb) && |
2935 | lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) { |
2936 | info->tf_valid = 1; |
2937 | info->tf_success = lvb->lvb_success; |
2938 | info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum); |
2939 | info->tf_start = be64_to_cpu(lvb->lvb_start); |
2940 | info->tf_len = be64_to_cpu(lvb->lvb_len); |
2941 | info->tf_minlen = be64_to_cpu(lvb->lvb_minlen); |
2942 | info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen); |
2943 | } |
2944 | } |
2945 | |
2946 | return status; |
2947 | } |
2948 | |
2949 | void ocfs2_trim_fs_unlock(struct ocfs2_super *osb, |
2950 | struct ocfs2_trim_fs_info *info) |
2951 | { |
2952 | struct ocfs2_trim_fs_lvb *lvb; |
2953 | struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; |
2954 | |
2955 | if (ocfs2_mount_local(osb)) |
2956 | return; |
2957 | |
2958 | if (info) { |
2959 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
2960 | lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION; |
2961 | lvb->lvb_success = info->tf_success; |
2962 | lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum); |
2963 | lvb->lvb_start = cpu_to_be64(info->tf_start); |
2964 | lvb->lvb_len = cpu_to_be64(info->tf_len); |
2965 | lvb->lvb_minlen = cpu_to_be64(info->tf_minlen); |
2966 | lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen); |
2967 | } |
2968 | |
2969 | ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); |
2970 | } |
2971 | |
2972 | int ocfs2_dentry_lock(struct dentry *dentry, int ex) |
2973 | { |
2974 | int ret; |
2975 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
2976 | struct ocfs2_dentry_lock *dl = dentry->d_fsdata; |
2977 | struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); |
2978 | |
2979 | BUG_ON(!dl); |
2980 | |
2981 | if (ocfs2_is_hard_readonly(osb)) { |
2982 | if (ex) |
2983 | return -EROFS; |
2984 | return 0; |
2985 | } |
2986 | |
2987 | if (ocfs2_mount_local(osb)) |
2988 | return 0; |
2989 | |
2990 | ret = ocfs2_cluster_lock(osb, lockres: &dl->dl_lockres, level, lkm_flags: 0, arg_flags: 0); |
2991 | if (ret < 0) |
2992 | mlog_errno(ret); |
2993 | |
2994 | return ret; |
2995 | } |
2996 | |
2997 | void ocfs2_dentry_unlock(struct dentry *dentry, int ex) |
2998 | { |
2999 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
3000 | struct ocfs2_dentry_lock *dl = dentry->d_fsdata; |
3001 | struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); |
3002 | |
3003 | if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) |
3004 | ocfs2_cluster_unlock(osb, lockres: &dl->dl_lockres, level); |
3005 | } |
3006 | |
3007 | /* Reference counting of the dlm debug structure. We want this because |
3008 | * open references on the debug inodes can live on after a mount, so |
3009 | * we can't rely on the ocfs2_super to always exist. */ |
3010 | static void ocfs2_dlm_debug_free(struct kref *kref) |
3011 | { |
3012 | struct ocfs2_dlm_debug *dlm_debug; |
3013 | |
3014 | dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt); |
3015 | |
3016 | kfree(objp: dlm_debug); |
3017 | } |
3018 | |
3019 | void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug) |
3020 | { |
3021 | if (dlm_debug) |
3022 | kref_put(kref: &dlm_debug->d_refcnt, release: ocfs2_dlm_debug_free); |
3023 | } |
3024 | |
3025 | static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug) |
3026 | { |
3027 | kref_get(kref: &debug->d_refcnt); |
3028 | } |
3029 | |
3030 | struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void) |
3031 | { |
3032 | struct ocfs2_dlm_debug *dlm_debug; |
3033 | |
3034 | dlm_debug = kmalloc(size: sizeof(struct ocfs2_dlm_debug), GFP_KERNEL); |
3035 | if (!dlm_debug) { |
3036 | mlog_errno(-ENOMEM); |
3037 | goto out; |
3038 | } |
3039 | |
3040 | kref_init(kref: &dlm_debug->d_refcnt); |
3041 | INIT_LIST_HEAD(list: &dlm_debug->d_lockres_tracking); |
3042 | dlm_debug->d_filter_secs = 0; |
3043 | out: |
3044 | return dlm_debug; |
3045 | } |
3046 | |
3047 | /* Access to this is arbitrated for us via seq_file->sem. */ |
3048 | struct ocfs2_dlm_seq_priv { |
3049 | struct ocfs2_dlm_debug *p_dlm_debug; |
3050 | struct ocfs2_lock_res p_iter_res; |
3051 | struct ocfs2_lock_res p_tmp_res; |
3052 | }; |
3053 | |
3054 | static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start, |
3055 | struct ocfs2_dlm_seq_priv *priv) |
3056 | { |
3057 | struct ocfs2_lock_res *iter, *ret = NULL; |
3058 | struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug; |
3059 | |
3060 | assert_spin_locked(&ocfs2_dlm_tracking_lock); |
3061 | |
3062 | list_for_each_entry(iter, &start->l_debug_list, l_debug_list) { |
3063 | /* discover the head of the list */ |
3064 | if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) { |
3065 | mlog(0, "End of list found, %p\n" , ret); |
3066 | break; |
3067 | } |
3068 | |
3069 | /* We track our "dummy" iteration lockres' by a NULL |
3070 | * l_ops field. */ |
3071 | if (iter->l_ops != NULL) { |
3072 | ret = iter; |
3073 | break; |
3074 | } |
3075 | } |
3076 | |
3077 | return ret; |
3078 | } |
3079 | |
3080 | static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos) |
3081 | { |
3082 | struct ocfs2_dlm_seq_priv *priv = m->private; |
3083 | struct ocfs2_lock_res *iter; |
3084 | |
3085 | spin_lock(lock: &ocfs2_dlm_tracking_lock); |
3086 | iter = ocfs2_dlm_next_res(start: &priv->p_iter_res, priv); |
3087 | if (iter) { |
3088 | /* Since lockres' have the lifetime of their container |
3089 | * (which can be inodes, ocfs2_supers, etc) we want to |
3090 | * copy this out to a temporary lockres while still |
3091 | * under the spinlock. Obviously after this we can't |
3092 | * trust any pointers on the copy returned, but that's |
3093 | * ok as the information we want isn't typically held |
3094 | * in them. */ |
3095 | priv->p_tmp_res = *iter; |
3096 | iter = &priv->p_tmp_res; |
3097 | } |
3098 | spin_unlock(lock: &ocfs2_dlm_tracking_lock); |
3099 | |
3100 | return iter; |
3101 | } |
3102 | |
3103 | static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v) |
3104 | { |
3105 | } |
3106 | |
3107 | static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos) |
3108 | { |
3109 | struct ocfs2_dlm_seq_priv *priv = m->private; |
3110 | struct ocfs2_lock_res *iter = v; |
3111 | struct ocfs2_lock_res *dummy = &priv->p_iter_res; |
3112 | |
3113 | spin_lock(lock: &ocfs2_dlm_tracking_lock); |
3114 | iter = ocfs2_dlm_next_res(start: iter, priv); |
3115 | list_del_init(entry: &dummy->l_debug_list); |
3116 | if (iter) { |
3117 | list_add(new: &dummy->l_debug_list, head: &iter->l_debug_list); |
3118 | priv->p_tmp_res = *iter; |
3119 | iter = &priv->p_tmp_res; |
3120 | } |
3121 | spin_unlock(lock: &ocfs2_dlm_tracking_lock); |
3122 | |
3123 | return iter; |
3124 | } |
3125 | |
3126 | /* |
3127 | * Version is used by debugfs.ocfs2 to determine the format being used |
3128 | * |
3129 | * New in version 2 |
3130 | * - Lock stats printed |
3131 | * New in version 3 |
3132 | * - Max time in lock stats is in usecs (instead of nsecs) |
3133 | * New in version 4 |
3134 | * - Add last pr/ex unlock times and first lock wait time in usecs |
3135 | */ |
3136 | #define OCFS2_DLM_DEBUG_STR_VERSION 4 |
3137 | static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) |
3138 | { |
3139 | int i; |
3140 | char *lvb; |
3141 | struct ocfs2_lock_res *lockres = v; |
3142 | #ifdef CONFIG_OCFS2_FS_STATS |
3143 | u64 now, last; |
3144 | struct ocfs2_dlm_debug *dlm_debug = |
3145 | ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug; |
3146 | #endif |
3147 | |
3148 | if (!lockres) |
3149 | return -EINVAL; |
3150 | |
3151 | #ifdef CONFIG_OCFS2_FS_STATS |
3152 | if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) { |
3153 | now = ktime_to_us(kt: ktime_get_real()); |
3154 | if (lockres->l_lock_prmode.ls_last > |
3155 | lockres->l_lock_exmode.ls_last) |
3156 | last = lockres->l_lock_prmode.ls_last; |
3157 | else |
3158 | last = lockres->l_lock_exmode.ls_last; |
3159 | /* |
3160 | * Use d_filter_secs field to filter lock resources dump, |
3161 | * the default d_filter_secs(0) value filters nothing, |
3162 | * otherwise, only dump the last N seconds active lock |
3163 | * resources. |
3164 | */ |
3165 | if (div_u64(dividend: now - last, divisor: 1000000) > dlm_debug->d_filter_secs) |
3166 | return 0; |
3167 | } |
3168 | #endif |
3169 | |
3170 | seq_printf(m, fmt: "0x%x\t" , OCFS2_DLM_DEBUG_STR_VERSION); |
3171 | |
3172 | if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY) |
3173 | seq_printf(m, fmt: "%.*s%08x\t" , OCFS2_DENTRY_LOCK_INO_START - 1, |
3174 | lockres->l_name, |
3175 | (unsigned int)ocfs2_get_dentry_lock_ino(lockres)); |
3176 | else |
3177 | seq_printf(m, fmt: "%.*s\t" , OCFS2_LOCK_ID_MAX_LEN, lockres->l_name); |
3178 | |
3179 | seq_printf(m, fmt: "%d\t" |
3180 | "0x%lx\t" |
3181 | "0x%x\t" |
3182 | "0x%x\t" |
3183 | "%u\t" |
3184 | "%u\t" |
3185 | "%d\t" |
3186 | "%d\t" , |
3187 | lockres->l_level, |
3188 | lockres->l_flags, |
3189 | lockres->l_action, |
3190 | lockres->l_unlock_action, |
3191 | lockres->l_ro_holders, |
3192 | lockres->l_ex_holders, |
3193 | lockres->l_requested, |
3194 | lockres->l_blocking); |
3195 | |
3196 | /* Dump the raw LVB */ |
3197 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
3198 | for(i = 0; i < DLM_LVB_LEN; i++) |
3199 | seq_printf(m, fmt: "0x%x\t" , lvb[i]); |
3200 | |
3201 | #ifdef CONFIG_OCFS2_FS_STATS |
3202 | # define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets) |
3203 | # define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets) |
3204 | # define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail) |
3205 | # define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail) |
3206 | # define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total) |
3207 | # define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total) |
3208 | # define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max) |
3209 | # define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max) |
3210 | # define lock_refresh(_l) ((_l)->l_lock_refresh) |
3211 | # define lock_last_prmode(_l) ((_l)->l_lock_prmode.ls_last) |
3212 | # define lock_last_exmode(_l) ((_l)->l_lock_exmode.ls_last) |
3213 | # define lock_wait(_l) ((_l)->l_lock_wait) |
3214 | #else |
3215 | # define lock_num_prmode(_l) (0) |
3216 | # define lock_num_exmode(_l) (0) |
3217 | # define lock_num_prmode_failed(_l) (0) |
3218 | # define lock_num_exmode_failed(_l) (0) |
3219 | # define lock_total_prmode(_l) (0ULL) |
3220 | # define lock_total_exmode(_l) (0ULL) |
3221 | # define lock_max_prmode(_l) (0) |
3222 | # define lock_max_exmode(_l) (0) |
3223 | # define lock_refresh(_l) (0) |
3224 | # define lock_last_prmode(_l) (0ULL) |
3225 | # define lock_last_exmode(_l) (0ULL) |
3226 | # define lock_wait(_l) (0ULL) |
3227 | #endif |
3228 | /* The following seq_print was added in version 2 of this output */ |
3229 | seq_printf(m, fmt: "%u\t" |
3230 | "%u\t" |
3231 | "%u\t" |
3232 | "%u\t" |
3233 | "%llu\t" |
3234 | "%llu\t" |
3235 | "%u\t" |
3236 | "%u\t" |
3237 | "%u\t" |
3238 | "%llu\t" |
3239 | "%llu\t" |
3240 | "%llu\t" , |
3241 | lock_num_prmode(lockres), |
3242 | lock_num_exmode(lockres), |
3243 | lock_num_prmode_failed(lockres), |
3244 | lock_num_exmode_failed(lockres), |
3245 | lock_total_prmode(lockres), |
3246 | lock_total_exmode(lockres), |
3247 | lock_max_prmode(lockres), |
3248 | lock_max_exmode(lockres), |
3249 | lock_refresh(lockres), |
3250 | lock_last_prmode(lockres), |
3251 | lock_last_exmode(lockres), |
3252 | lock_wait(lockres)); |
3253 | |
3254 | /* End the line */ |
3255 | seq_printf(m, fmt: "\n" ); |
3256 | return 0; |
3257 | } |
3258 | |
3259 | static const struct seq_operations ocfs2_dlm_seq_ops = { |
3260 | .start = ocfs2_dlm_seq_start, |
3261 | .stop = ocfs2_dlm_seq_stop, |
3262 | .next = ocfs2_dlm_seq_next, |
3263 | .show = ocfs2_dlm_seq_show, |
3264 | }; |
3265 | |
3266 | static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file) |
3267 | { |
3268 | struct seq_file *seq = file->private_data; |
3269 | struct ocfs2_dlm_seq_priv *priv = seq->private; |
3270 | struct ocfs2_lock_res *res = &priv->p_iter_res; |
3271 | |
3272 | ocfs2_remove_lockres_tracking(res); |
3273 | ocfs2_put_dlm_debug(dlm_debug: priv->p_dlm_debug); |
3274 | return seq_release_private(inode, file); |
3275 | } |
3276 | |
3277 | static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) |
3278 | { |
3279 | struct ocfs2_dlm_seq_priv *priv; |
3280 | struct ocfs2_super *osb; |
3281 | |
3282 | priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv)); |
3283 | if (!priv) { |
3284 | mlog_errno(-ENOMEM); |
3285 | return -ENOMEM; |
3286 | } |
3287 | |
3288 | osb = inode->i_private; |
3289 | ocfs2_get_dlm_debug(debug: osb->osb_dlm_debug); |
3290 | priv->p_dlm_debug = osb->osb_dlm_debug; |
3291 | INIT_LIST_HEAD(list: &priv->p_iter_res.l_debug_list); |
3292 | |
3293 | ocfs2_add_lockres_tracking(res: &priv->p_iter_res, |
3294 | dlm_debug: priv->p_dlm_debug); |
3295 | |
3296 | return 0; |
3297 | } |
3298 | |
3299 | static const struct file_operations ocfs2_dlm_debug_fops = { |
3300 | .open = ocfs2_dlm_debug_open, |
3301 | .release = ocfs2_dlm_debug_release, |
3302 | .read = seq_read, |
3303 | .llseek = seq_lseek, |
3304 | }; |
3305 | |
3306 | static void ocfs2_dlm_init_debug(struct ocfs2_super *osb) |
3307 | { |
3308 | struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; |
3309 | |
3310 | debugfs_create_file(name: "locking_state" , S_IFREG|S_IRUSR, |
3311 | parent: osb->osb_debug_root, data: osb, fops: &ocfs2_dlm_debug_fops); |
3312 | |
3313 | debugfs_create_u32(name: "locking_filter" , mode: 0600, parent: osb->osb_debug_root, |
3314 | value: &dlm_debug->d_filter_secs); |
3315 | ocfs2_get_dlm_debug(debug: dlm_debug); |
3316 | } |
3317 | |
3318 | static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb) |
3319 | { |
3320 | struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; |
3321 | |
3322 | if (dlm_debug) |
3323 | ocfs2_put_dlm_debug(dlm_debug); |
3324 | } |
3325 | |
3326 | int ocfs2_dlm_init(struct ocfs2_super *osb) |
3327 | { |
3328 | int status = 0; |
3329 | struct ocfs2_cluster_connection *conn = NULL; |
3330 | |
3331 | if (ocfs2_mount_local(osb)) { |
3332 | osb->node_num = 0; |
3333 | goto local; |
3334 | } |
3335 | |
3336 | ocfs2_dlm_init_debug(osb); |
3337 | |
3338 | /* launch downconvert thread */ |
3339 | osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s" , |
3340 | osb->uuid_str); |
3341 | if (IS_ERR(ptr: osb->dc_task)) { |
3342 | status = PTR_ERR(ptr: osb->dc_task); |
3343 | osb->dc_task = NULL; |
3344 | mlog_errno(status); |
3345 | goto bail; |
3346 | } |
3347 | |
3348 | /* for now, uuid == domain */ |
3349 | status = ocfs2_cluster_connect(stack_name: osb->osb_cluster_stack, |
3350 | cluster_name: osb->osb_cluster_name, |
3351 | strlen(osb->osb_cluster_name), |
3352 | group: osb->uuid_str, |
3353 | strlen(osb->uuid_str), |
3354 | lproto: &lproto, recovery_handler: ocfs2_do_node_down, recovery_data: osb, |
3355 | conn: &conn); |
3356 | if (status) { |
3357 | mlog_errno(status); |
3358 | goto bail; |
3359 | } |
3360 | |
3361 | status = ocfs2_cluster_this_node(conn, node: &osb->node_num); |
3362 | if (status < 0) { |
3363 | mlog_errno(status); |
3364 | mlog(ML_ERROR, |
3365 | "could not find this host's node number\n" ); |
3366 | ocfs2_cluster_disconnect(conn, hangup_pending: 0); |
3367 | goto bail; |
3368 | } |
3369 | |
3370 | local: |
3371 | ocfs2_super_lock_res_init(res: &osb->osb_super_lockres, osb); |
3372 | ocfs2_rename_lock_res_init(res: &osb->osb_rename_lockres, osb); |
3373 | ocfs2_nfs_sync_lock_init(osb); |
3374 | ocfs2_orphan_scan_lock_res_init(res: &osb->osb_orphan_scan.os_lockres, osb); |
3375 | |
3376 | osb->cconn = conn; |
3377 | bail: |
3378 | if (status < 0) { |
3379 | ocfs2_dlm_shutdown_debug(osb); |
3380 | if (osb->dc_task) |
3381 | kthread_stop(k: osb->dc_task); |
3382 | } |
3383 | |
3384 | return status; |
3385 | } |
3386 | |
3387 | void ocfs2_dlm_shutdown(struct ocfs2_super *osb, |
3388 | int hangup_pending) |
3389 | { |
3390 | ocfs2_drop_osb_locks(osb); |
3391 | |
3392 | /* |
3393 | * Now that we have dropped all locks and ocfs2_dismount_volume() |
3394 | * has disabled recovery, the DLM won't be talking to us. It's |
3395 | * safe to tear things down before disconnecting the cluster. |
3396 | */ |
3397 | |
3398 | if (osb->dc_task) { |
3399 | kthread_stop(k: osb->dc_task); |
3400 | osb->dc_task = NULL; |
3401 | } |
3402 | |
3403 | ocfs2_lock_res_free(res: &osb->osb_super_lockres); |
3404 | ocfs2_lock_res_free(res: &osb->osb_rename_lockres); |
3405 | ocfs2_lock_res_free(res: &osb->osb_nfs_sync_lockres); |
3406 | ocfs2_lock_res_free(res: &osb->osb_orphan_scan.os_lockres); |
3407 | |
3408 | if (osb->cconn) { |
3409 | ocfs2_cluster_disconnect(conn: osb->cconn, hangup_pending); |
3410 | osb->cconn = NULL; |
3411 | |
3412 | ocfs2_dlm_shutdown_debug(osb); |
3413 | } |
3414 | } |
3415 | |
3416 | static int ocfs2_drop_lock(struct ocfs2_super *osb, |
3417 | struct ocfs2_lock_res *lockres) |
3418 | { |
3419 | int ret; |
3420 | unsigned long flags; |
3421 | u32 lkm_flags = 0; |
3422 | |
3423 | /* We didn't get anywhere near actually using this lockres. */ |
3424 | if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) |
3425 | goto out; |
3426 | |
3427 | if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) |
3428 | lkm_flags |= DLM_LKF_VALBLK; |
3429 | |
3430 | spin_lock_irqsave(&lockres->l_lock, flags); |
3431 | |
3432 | mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING), |
3433 | "lockres %s, flags 0x%lx\n" , |
3434 | lockres->l_name, lockres->l_flags); |
3435 | |
3436 | while (lockres->l_flags & OCFS2_LOCK_BUSY) { |
3437 | mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = " |
3438 | "%u, unlock_action = %u\n" , |
3439 | lockres->l_name, lockres->l_flags, lockres->l_action, |
3440 | lockres->l_unlock_action); |
3441 | |
3442 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3443 | |
3444 | /* XXX: Today we just wait on any busy |
3445 | * locks... Perhaps we need to cancel converts in the |
3446 | * future? */ |
3447 | ocfs2_wait_on_busy_lock(lockres); |
3448 | |
3449 | spin_lock_irqsave(&lockres->l_lock, flags); |
3450 | } |
3451 | |
3452 | if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { |
3453 | if (lockres->l_flags & OCFS2_LOCK_ATTACHED && |
3454 | lockres->l_level == DLM_LOCK_EX && |
3455 | !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) |
3456 | lockres->l_ops->set_lvb(lockres); |
3457 | } |
3458 | |
3459 | if (lockres->l_flags & OCFS2_LOCK_BUSY) |
3460 | mlog(ML_ERROR, "destroying busy lock: \"%s\"\n" , |
3461 | lockres->l_name); |
3462 | if (lockres->l_flags & OCFS2_LOCK_BLOCKED) |
3463 | mlog(0, "destroying blocked lock: \"%s\"\n" , lockres->l_name); |
3464 | |
3465 | if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { |
3466 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3467 | goto out; |
3468 | } |
3469 | |
3470 | lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED); |
3471 | |
3472 | /* make sure we never get here while waiting for an ast to |
3473 | * fire. */ |
3474 | BUG_ON(lockres->l_action != OCFS2_AST_INVALID); |
3475 | |
3476 | /* is this necessary? */ |
3477 | lockres_or_flags(lockres, OCFS2_LOCK_BUSY); |
3478 | lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK; |
3479 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3480 | |
3481 | mlog(0, "lock %s\n" , lockres->l_name); |
3482 | |
3483 | ret = ocfs2_dlm_unlock(conn: osb->cconn, lksb: &lockres->l_lksb, flags: lkm_flags); |
3484 | if (ret) { |
3485 | ocfs2_log_dlm_error("ocfs2_dlm_unlock" , ret, lockres); |
3486 | mlog(ML_ERROR, "lockres flags: %lu\n" , lockres->l_flags); |
3487 | ocfs2_dlm_dump_lksb(lksb: &lockres->l_lksb); |
3488 | BUG(); |
3489 | } |
3490 | mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n" , |
3491 | lockres->l_name); |
3492 | |
3493 | ocfs2_wait_on_busy_lock(lockres); |
3494 | out: |
3495 | return 0; |
3496 | } |
3497 | |
3498 | static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, |
3499 | struct ocfs2_lock_res *lockres); |
3500 | |
3501 | /* Mark the lockres as being dropped. It will no longer be |
3502 | * queued if blocking, but we still may have to wait on it |
3503 | * being dequeued from the downconvert thread before we can consider |
3504 | * it safe to drop. |
3505 | * |
3506 | * You can *not* attempt to call cluster_lock on this lockres anymore. */ |
3507 | void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb, |
3508 | struct ocfs2_lock_res *lockres) |
3509 | { |
3510 | int status; |
3511 | struct ocfs2_mask_waiter mw; |
3512 | unsigned long flags, flags2; |
3513 | |
3514 | ocfs2_init_mask_waiter(mw: &mw); |
3515 | |
3516 | spin_lock_irqsave(&lockres->l_lock, flags); |
3517 | lockres->l_flags |= OCFS2_LOCK_FREEING; |
3518 | if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) { |
3519 | /* |
3520 | * We know the downconvert is queued but not in progress |
3521 | * because we are the downconvert thread and processing |
3522 | * different lock. So we can just remove the lock from the |
3523 | * queue. This is not only an optimization but also a way |
3524 | * to avoid the following deadlock: |
3525 | * ocfs2_dentry_post_unlock() |
3526 | * ocfs2_dentry_lock_put() |
3527 | * ocfs2_drop_dentry_lock() |
3528 | * iput() |
3529 | * ocfs2_evict_inode() |
3530 | * ocfs2_clear_inode() |
3531 | * ocfs2_mark_lockres_freeing() |
3532 | * ... blocks waiting for OCFS2_LOCK_QUEUED |
3533 | * since we are the downconvert thread which |
3534 | * should clear the flag. |
3535 | */ |
3536 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3537 | spin_lock_irqsave(&osb->dc_task_lock, flags2); |
3538 | list_del_init(entry: &lockres->l_blocked_list); |
3539 | osb->blocked_lock_count--; |
3540 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags: flags2); |
3541 | /* |
3542 | * Warn if we recurse into another post_unlock call. Strictly |
3543 | * speaking it isn't a problem but we need to be careful if |
3544 | * that happens (stack overflow, deadlocks, ...) so warn if |
3545 | * ocfs2 grows a path for which this can happen. |
3546 | */ |
3547 | WARN_ON_ONCE(lockres->l_ops->post_unlock); |
3548 | /* Since the lock is freeing we don't do much in the fn below */ |
3549 | ocfs2_process_blocked_lock(osb, lockres); |
3550 | return; |
3551 | } |
3552 | while (lockres->l_flags & OCFS2_LOCK_QUEUED) { |
3553 | lockres_add_mask_waiter(lockres, mw: &mw, OCFS2_LOCK_QUEUED, goal: 0); |
3554 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3555 | |
3556 | mlog(0, "Waiting on lockres %s\n" , lockres->l_name); |
3557 | |
3558 | status = ocfs2_wait_for_mask(mw: &mw); |
3559 | if (status) |
3560 | mlog_errno(status); |
3561 | |
3562 | spin_lock_irqsave(&lockres->l_lock, flags); |
3563 | } |
3564 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3565 | } |
3566 | |
3567 | void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, |
3568 | struct ocfs2_lock_res *lockres) |
3569 | { |
3570 | int ret; |
3571 | |
3572 | ocfs2_mark_lockres_freeing(osb, lockres); |
3573 | ret = ocfs2_drop_lock(osb, lockres); |
3574 | if (ret) |
3575 | mlog_errno(ret); |
3576 | } |
3577 | |
3578 | static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) |
3579 | { |
3580 | ocfs2_simple_drop_lockres(osb, lockres: &osb->osb_super_lockres); |
3581 | ocfs2_simple_drop_lockres(osb, lockres: &osb->osb_rename_lockres); |
3582 | ocfs2_simple_drop_lockres(osb, lockres: &osb->osb_nfs_sync_lockres); |
3583 | ocfs2_simple_drop_lockres(osb, lockres: &osb->osb_orphan_scan.os_lockres); |
3584 | } |
3585 | |
3586 | int ocfs2_drop_inode_locks(struct inode *inode) |
3587 | { |
3588 | int status, err; |
3589 | |
3590 | /* No need to call ocfs2_mark_lockres_freeing here - |
3591 | * ocfs2_clear_inode has done it for us. */ |
3592 | |
3593 | err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), |
3594 | lockres: &OCFS2_I(inode)->ip_open_lockres); |
3595 | if (err < 0) |
3596 | mlog_errno(err); |
3597 | |
3598 | status = err; |
3599 | |
3600 | err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), |
3601 | lockres: &OCFS2_I(inode)->ip_inode_lockres); |
3602 | if (err < 0) |
3603 | mlog_errno(err); |
3604 | if (err < 0 && !status) |
3605 | status = err; |
3606 | |
3607 | err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), |
3608 | lockres: &OCFS2_I(inode)->ip_rw_lockres); |
3609 | if (err < 0) |
3610 | mlog_errno(err); |
3611 | if (err < 0 && !status) |
3612 | status = err; |
3613 | |
3614 | return status; |
3615 | } |
3616 | |
3617 | static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, |
3618 | int new_level) |
3619 | { |
3620 | assert_spin_locked(&lockres->l_lock); |
3621 | |
3622 | BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); |
3623 | |
3624 | if (lockres->l_level <= new_level) { |
3625 | mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, " |
3626 | "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, " |
3627 | "block %d, pgen %d\n" , lockres->l_name, lockres->l_level, |
3628 | new_level, list_empty(&lockres->l_blocked_list), |
3629 | list_empty(&lockres->l_mask_waiters), lockres->l_type, |
3630 | lockres->l_flags, lockres->l_ro_holders, |
3631 | lockres->l_ex_holders, lockres->l_action, |
3632 | lockres->l_unlock_action, lockres->l_requested, |
3633 | lockres->l_blocking, lockres->l_pending_gen); |
3634 | BUG(); |
3635 | } |
3636 | |
3637 | mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n" , |
3638 | lockres->l_name, lockres->l_level, new_level, lockres->l_blocking); |
3639 | |
3640 | lockres->l_action = OCFS2_AST_DOWNCONVERT; |
3641 | lockres->l_requested = new_level; |
3642 | lockres_or_flags(lockres, OCFS2_LOCK_BUSY); |
3643 | return lockres_set_pending(lockres); |
3644 | } |
3645 | |
3646 | static int ocfs2_downconvert_lock(struct ocfs2_super *osb, |
3647 | struct ocfs2_lock_res *lockres, |
3648 | int new_level, |
3649 | int lvb, |
3650 | unsigned int generation) |
3651 | { |
3652 | int ret; |
3653 | u32 dlm_flags = DLM_LKF_CONVERT; |
3654 | |
3655 | mlog(ML_BASTS, "lockres %s, level %d => %d\n" , lockres->l_name, |
3656 | lockres->l_level, new_level); |
3657 | |
3658 | /* |
3659 | * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always |
3660 | * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that |
3661 | * we can recover correctly from node failure. Otherwise, we may get |
3662 | * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set. |
3663 | */ |
3664 | if (ocfs2_userspace_stack(osb) && |
3665 | lockres->l_ops->flags & LOCK_TYPE_USES_LVB) |
3666 | lvb = 1; |
3667 | |
3668 | if (lvb) |
3669 | dlm_flags |= DLM_LKF_VALBLK; |
3670 | |
3671 | ret = ocfs2_dlm_lock(conn: osb->cconn, |
3672 | mode: new_level, |
3673 | lksb: &lockres->l_lksb, |
3674 | flags: dlm_flags, |
3675 | name: lockres->l_name, |
3676 | OCFS2_LOCK_ID_MAX_LEN - 1); |
3677 | lockres_clear_pending(lockres, generation, osb); |
3678 | if (ret) { |
3679 | ocfs2_log_dlm_error("ocfs2_dlm_lock" , ret, lockres); |
3680 | ocfs2_recover_from_dlm_error(lockres, convert: 1); |
3681 | goto bail; |
3682 | } |
3683 | |
3684 | ret = 0; |
3685 | bail: |
3686 | return ret; |
3687 | } |
3688 | |
3689 | /* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */ |
3690 | static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, |
3691 | struct ocfs2_lock_res *lockres) |
3692 | { |
3693 | assert_spin_locked(&lockres->l_lock); |
3694 | |
3695 | if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { |
3696 | /* If we're already trying to cancel a lock conversion |
3697 | * then just drop the spinlock and allow the caller to |
3698 | * requeue this lock. */ |
3699 | mlog(ML_BASTS, "lockres %s, skip convert\n" , lockres->l_name); |
3700 | return 0; |
3701 | } |
3702 | |
3703 | /* were we in a convert when we got the bast fire? */ |
3704 | BUG_ON(lockres->l_action != OCFS2_AST_CONVERT && |
3705 | lockres->l_action != OCFS2_AST_DOWNCONVERT); |
3706 | /* set things up for the unlockast to know to just |
3707 | * clear out the ast_action and unset busy, etc. */ |
3708 | lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT; |
3709 | |
3710 | mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY), |
3711 | "lock %s, invalid flags: 0x%lx\n" , |
3712 | lockres->l_name, lockres->l_flags); |
3713 | |
3714 | mlog(ML_BASTS, "lockres %s\n" , lockres->l_name); |
3715 | |
3716 | return 1; |
3717 | } |
3718 | |
3719 | static int ocfs2_cancel_convert(struct ocfs2_super *osb, |
3720 | struct ocfs2_lock_res *lockres) |
3721 | { |
3722 | int ret; |
3723 | |
3724 | ret = ocfs2_dlm_unlock(conn: osb->cconn, lksb: &lockres->l_lksb, |
3725 | DLM_LKF_CANCEL); |
3726 | if (ret) { |
3727 | ocfs2_log_dlm_error("ocfs2_dlm_unlock" , ret, lockres); |
3728 | ocfs2_recover_from_dlm_error(lockres, convert: 0); |
3729 | } |
3730 | |
3731 | mlog(ML_BASTS, "lockres %s\n" , lockres->l_name); |
3732 | |
3733 | return ret; |
3734 | } |
3735 | |
3736 | static int ocfs2_unblock_lock(struct ocfs2_super *osb, |
3737 | struct ocfs2_lock_res *lockres, |
3738 | struct ocfs2_unblock_ctl *ctl) |
3739 | { |
3740 | unsigned long flags; |
3741 | int blocking; |
3742 | int new_level; |
3743 | int level; |
3744 | int ret = 0; |
3745 | int set_lvb = 0; |
3746 | unsigned int gen; |
3747 | |
3748 | spin_lock_irqsave(&lockres->l_lock, flags); |
3749 | |
3750 | recheck: |
3751 | /* |
3752 | * Is it still blocking? If not, we have no more work to do. |
3753 | */ |
3754 | if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) { |
3755 | BUG_ON(lockres->l_blocking != DLM_LOCK_NL); |
3756 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3757 | ret = 0; |
3758 | goto leave; |
3759 | } |
3760 | |
3761 | if (lockres->l_flags & OCFS2_LOCK_BUSY) { |
3762 | /* XXX |
3763 | * This is a *big* race. The OCFS2_LOCK_PENDING flag |
3764 | * exists entirely for one reason - another thread has set |
3765 | * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock(). |
3766 | * |
3767 | * If we do ocfs2_cancel_convert() before the other thread |
3768 | * calls dlm_lock(), our cancel will do nothing. We will |
3769 | * get no ast, and we will have no way of knowing the |
3770 | * cancel failed. Meanwhile, the other thread will call |
3771 | * into dlm_lock() and wait...forever. |
3772 | * |
3773 | * Why forever? Because another node has asked for the |
3774 | * lock first; that's why we're here in unblock_lock(). |
3775 | * |
3776 | * The solution is OCFS2_LOCK_PENDING. When PENDING is |
3777 | * set, we just requeue the unblock. Only when the other |
3778 | * thread has called dlm_lock() and cleared PENDING will |
3779 | * we then cancel their request. |
3780 | * |
3781 | * All callers of dlm_lock() must set OCFS2_DLM_PENDING |
3782 | * at the same time they set OCFS2_DLM_BUSY. They must |
3783 | * clear OCFS2_DLM_PENDING after dlm_lock() returns. |
3784 | */ |
3785 | if (lockres->l_flags & OCFS2_LOCK_PENDING) { |
3786 | mlog(ML_BASTS, "lockres %s, ReQ: Pending\n" , |
3787 | lockres->l_name); |
3788 | goto leave_requeue; |
3789 | } |
3790 | |
3791 | ctl->requeue = 1; |
3792 | ret = ocfs2_prepare_cancel_convert(osb, lockres); |
3793 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3794 | if (ret) { |
3795 | ret = ocfs2_cancel_convert(osb, lockres); |
3796 | if (ret < 0) |
3797 | mlog_errno(ret); |
3798 | } |
3799 | goto leave; |
3800 | } |
3801 | |
3802 | /* |
3803 | * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is |
3804 | * set when the ast is received for an upconvert just before the |
3805 | * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast |
3806 | * on the heels of the ast, we want to delay the downconvert just |
3807 | * enough to allow the up requestor to do its task. Because this |
3808 | * lock is in the blocked queue, the lock will be downconverted |
3809 | * as soon as the requestor is done with the lock. |
3810 | */ |
3811 | if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) |
3812 | goto leave_requeue; |
3813 | |
3814 | /* |
3815 | * How can we block and yet be at NL? We were trying to upconvert |
3816 | * from NL and got canceled. The code comes back here, and now |
3817 | * we notice and clear BLOCKING. |
3818 | */ |
3819 | if (lockres->l_level == DLM_LOCK_NL) { |
3820 | BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders); |
3821 | mlog(ML_BASTS, "lockres %s, Aborting dc\n" , lockres->l_name); |
3822 | lockres->l_blocking = DLM_LOCK_NL; |
3823 | lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); |
3824 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3825 | goto leave; |
3826 | } |
3827 | |
3828 | /* if we're blocking an exclusive and we have *any* holders, |
3829 | * then requeue. */ |
3830 | if ((lockres->l_blocking == DLM_LOCK_EX) |
3831 | && (lockres->l_ex_holders || lockres->l_ro_holders)) { |
3832 | mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n" , |
3833 | lockres->l_name, lockres->l_ex_holders, |
3834 | lockres->l_ro_holders); |
3835 | goto leave_requeue; |
3836 | } |
3837 | |
3838 | /* If it's a PR we're blocking, then only |
3839 | * requeue if we've got any EX holders */ |
3840 | if (lockres->l_blocking == DLM_LOCK_PR && |
3841 | lockres->l_ex_holders) { |
3842 | mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n" , |
3843 | lockres->l_name, lockres->l_ex_holders); |
3844 | goto leave_requeue; |
3845 | } |
3846 | |
3847 | /* |
3848 | * Can we get a lock in this state if the holder counts are |
3849 | * zero? The meta data unblock code used to check this. |
3850 | */ |
3851 | if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) |
3852 | && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) { |
3853 | mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n" , |
3854 | lockres->l_name); |
3855 | goto leave_requeue; |
3856 | } |
3857 | |
3858 | new_level = ocfs2_highest_compat_lock_level(level: lockres->l_blocking); |
3859 | |
3860 | if (lockres->l_ops->check_downconvert |
3861 | && !lockres->l_ops->check_downconvert(lockres, new_level)) { |
3862 | mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n" , |
3863 | lockres->l_name); |
3864 | goto leave_requeue; |
3865 | } |
3866 | |
3867 | /* If we get here, then we know that there are no more |
3868 | * incompatible holders (and anyone asking for an incompatible |
3869 | * lock is blocked). We can now downconvert the lock */ |
3870 | if (!lockres->l_ops->downconvert_worker) |
3871 | goto downconvert; |
3872 | |
3873 | /* Some lockres types want to do a bit of work before |
3874 | * downconverting a lock. Allow that here. The worker function |
3875 | * may sleep, so we save off a copy of what we're blocking as |
3876 | * it may change while we're not holding the spin lock. */ |
3877 | blocking = lockres->l_blocking; |
3878 | level = lockres->l_level; |
3879 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3880 | |
3881 | ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking); |
3882 | |
3883 | if (ctl->unblock_action == UNBLOCK_STOP_POST) { |
3884 | mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n" , |
3885 | lockres->l_name); |
3886 | goto leave; |
3887 | } |
3888 | |
3889 | spin_lock_irqsave(&lockres->l_lock, flags); |
3890 | if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) { |
3891 | /* If this changed underneath us, then we can't drop |
3892 | * it just yet. */ |
3893 | mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, " |
3894 | "Recheck\n" , lockres->l_name, blocking, |
3895 | lockres->l_blocking, level, lockres->l_level); |
3896 | goto recheck; |
3897 | } |
3898 | |
3899 | downconvert: |
3900 | ctl->requeue = 0; |
3901 | |
3902 | if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { |
3903 | if (lockres->l_level == DLM_LOCK_EX) |
3904 | set_lvb = 1; |
3905 | |
3906 | /* |
3907 | * We only set the lvb if the lock has been fully |
3908 | * refreshed - otherwise we risk setting stale |
3909 | * data. Otherwise, there's no need to actually clear |
3910 | * out the lvb here as it's value is still valid. |
3911 | */ |
3912 | if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) |
3913 | lockres->l_ops->set_lvb(lockres); |
3914 | } |
3915 | |
3916 | gen = ocfs2_prepare_downconvert(lockres, new_level); |
3917 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3918 | ret = ocfs2_downconvert_lock(osb, lockres, new_level, lvb: set_lvb, |
3919 | generation: gen); |
3920 | /* The dlm lock convert is being cancelled in background, |
3921 | * ocfs2_cancel_convert() is asynchronous in fs/dlm, |
3922 | * requeue it, try again later. |
3923 | */ |
3924 | if (ret == -EBUSY) { |
3925 | ctl->requeue = 1; |
3926 | mlog(ML_BASTS, "lockres %s, ReQ: Downconvert busy\n" , |
3927 | lockres->l_name); |
3928 | ret = 0; |
3929 | msleep(msecs: 20); |
3930 | } |
3931 | |
3932 | leave: |
3933 | if (ret) |
3934 | mlog_errno(ret); |
3935 | return ret; |
3936 | |
3937 | leave_requeue: |
3938 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
3939 | ctl->requeue = 1; |
3940 | |
3941 | return 0; |
3942 | } |
3943 | |
3944 | static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, |
3945 | int blocking) |
3946 | { |
3947 | struct inode *inode; |
3948 | struct address_space *mapping; |
3949 | struct ocfs2_inode_info *oi; |
3950 | |
3951 | inode = ocfs2_lock_res_inode(lockres); |
3952 | mapping = inode->i_mapping; |
3953 | |
3954 | if (S_ISDIR(inode->i_mode)) { |
3955 | oi = OCFS2_I(inode); |
3956 | oi->ip_dir_lock_gen++; |
3957 | mlog(0, "generation: %u\n" , oi->ip_dir_lock_gen); |
3958 | goto out_forget; |
3959 | } |
3960 | |
3961 | if (!S_ISREG(inode->i_mode)) |
3962 | goto out; |
3963 | |
3964 | /* |
3965 | * We need this before the filemap_fdatawrite() so that it can |
3966 | * transfer the dirty bit from the PTE to the |
3967 | * page. Unfortunately this means that even for EX->PR |
3968 | * downconverts, we'll lose our mappings and have to build |
3969 | * them up again. |
3970 | */ |
3971 | unmap_mapping_range(mapping, holebegin: 0, holelen: 0, even_cows: 0); |
3972 | |
3973 | if (filemap_fdatawrite(mapping)) { |
3974 | mlog(ML_ERROR, "Could not sync inode %llu for downconvert!" , |
3975 | (unsigned long long)OCFS2_I(inode)->ip_blkno); |
3976 | } |
3977 | sync_mapping_buffers(mapping); |
3978 | if (blocking == DLM_LOCK_EX) { |
3979 | truncate_inode_pages(mapping, 0); |
3980 | } else { |
3981 | /* We only need to wait on the I/O if we're not also |
3982 | * truncating pages because truncate_inode_pages waits |
3983 | * for us above. We don't truncate pages if we're |
3984 | * blocking anything < EXMODE because we want to keep |
3985 | * them around in that case. */ |
3986 | filemap_fdatawait(mapping); |
3987 | } |
3988 | |
3989 | out_forget: |
3990 | forget_all_cached_acls(inode); |
3991 | |
3992 | out: |
3993 | return UNBLOCK_CONTINUE; |
3994 | } |
3995 | |
3996 | static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci, |
3997 | struct ocfs2_lock_res *lockres, |
3998 | int new_level) |
3999 | { |
4000 | int checkpointed = ocfs2_ci_fully_checkpointed(ci); |
4001 | |
4002 | BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR); |
4003 | BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed); |
4004 | |
4005 | if (checkpointed) |
4006 | return 1; |
4007 | |
4008 | ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci))); |
4009 | return 0; |
4010 | } |
4011 | |
4012 | static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, |
4013 | int new_level) |
4014 | { |
4015 | struct inode *inode = ocfs2_lock_res_inode(lockres); |
4016 | |
4017 | return ocfs2_ci_checkpointed(ci: INODE_CACHE(inode), lockres, new_level); |
4018 | } |
4019 | |
4020 | static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres) |
4021 | { |
4022 | struct inode *inode = ocfs2_lock_res_inode(lockres); |
4023 | |
4024 | __ocfs2_stuff_meta_lvb(inode); |
4025 | } |
4026 | |
4027 | /* |
4028 | * Does the final reference drop on our dentry lock. Right now this |
4029 | * happens in the downconvert thread, but we could choose to simplify the |
4030 | * dlmglue API and push these off to the ocfs2_wq in the future. |
4031 | */ |
4032 | static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, |
4033 | struct ocfs2_lock_res *lockres) |
4034 | { |
4035 | struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); |
4036 | ocfs2_dentry_lock_put(osb, dl); |
4037 | } |
4038 | |
4039 | /* |
4040 | * d_delete() matching dentries before the lock downconvert. |
4041 | * |
4042 | * At this point, any process waiting to destroy the |
4043 | * dentry_lock due to last ref count is stopped by the |
4044 | * OCFS2_LOCK_QUEUED flag. |
4045 | * |
4046 | * We have two potential problems |
4047 | * |
4048 | * 1) If we do the last reference drop on our dentry_lock (via dput) |
4049 | * we'll wind up in ocfs2_release_dentry_lock(), waiting on |
4050 | * the downconvert to finish. Instead we take an elevated |
4051 | * reference and push the drop until after we've completed our |
4052 | * unblock processing. |
4053 | * |
4054 | * 2) There might be another process with a final reference, |
4055 | * waiting on us to finish processing. If this is the case, we |
4056 | * detect it and exit out - there's no more dentries anyway. |
4057 | */ |
4058 | static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, |
4059 | int blocking) |
4060 | { |
4061 | struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); |
4062 | struct ocfs2_inode_info *oi = OCFS2_I(inode: dl->dl_inode); |
4063 | struct dentry *dentry; |
4064 | unsigned long flags; |
4065 | int = 0; |
4066 | |
4067 | /* |
4068 | * This node is blocking another node from getting a read |
4069 | * lock. This happens when we've renamed within a |
4070 | * directory. We've forced the other nodes to d_delete(), but |
4071 | * we never actually dropped our lock because it's still |
4072 | * valid. The downconvert code will retain a PR for this node, |
4073 | * so there's no further work to do. |
4074 | */ |
4075 | if (blocking == DLM_LOCK_PR) |
4076 | return UNBLOCK_CONTINUE; |
4077 | |
4078 | /* |
4079 | * Mark this inode as potentially orphaned. The code in |
4080 | * ocfs2_delete_inode() will figure out whether it actually |
4081 | * needs to be freed or not. |
4082 | */ |
4083 | spin_lock(lock: &oi->ip_lock); |
4084 | oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; |
4085 | spin_unlock(lock: &oi->ip_lock); |
4086 | |
4087 | /* |
4088 | * Yuck. We need to make sure however that the check of |
4089 | * OCFS2_LOCK_FREEING and the extra reference are atomic with |
4090 | * respect to a reference decrement or the setting of that |
4091 | * flag. |
4092 | */ |
4093 | spin_lock_irqsave(&lockres->l_lock, flags); |
4094 | spin_lock(lock: &dentry_attach_lock); |
4095 | if (!(lockres->l_flags & OCFS2_LOCK_FREEING) |
4096 | && dl->dl_count) { |
4097 | dl->dl_count++; |
4098 | extra_ref = 1; |
4099 | } |
4100 | spin_unlock(lock: &dentry_attach_lock); |
4101 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
4102 | |
4103 | mlog(0, "extra_ref = %d\n" , extra_ref); |
4104 | |
4105 | /* |
4106 | * We have a process waiting on us in ocfs2_dentry_iput(), |
4107 | * which means we can't have any more outstanding |
4108 | * aliases. There's no need to do any more work. |
4109 | */ |
4110 | if (!extra_ref) |
4111 | return UNBLOCK_CONTINUE; |
4112 | |
4113 | spin_lock(lock: &dentry_attach_lock); |
4114 | while (1) { |
4115 | dentry = ocfs2_find_local_alias(inode: dl->dl_inode, |
4116 | parent_blkno: dl->dl_parent_blkno, skip_unhashed: 1); |
4117 | if (!dentry) |
4118 | break; |
4119 | spin_unlock(lock: &dentry_attach_lock); |
4120 | |
4121 | if (S_ISDIR(dl->dl_inode->i_mode)) |
4122 | shrink_dcache_parent(dentry); |
4123 | |
4124 | mlog(0, "d_delete(%pd);\n" , dentry); |
4125 | |
4126 | /* |
4127 | * The following dcache calls may do an |
4128 | * iput(). Normally we don't want that from the |
4129 | * downconverting thread, but in this case it's ok |
4130 | * because the requesting node already has an |
4131 | * exclusive lock on the inode, so it can't be queued |
4132 | * for a downconvert. |
4133 | */ |
4134 | d_delete(dentry); |
4135 | dput(dentry); |
4136 | |
4137 | spin_lock(lock: &dentry_attach_lock); |
4138 | } |
4139 | spin_unlock(lock: &dentry_attach_lock); |
4140 | |
4141 | /* |
4142 | * If we are the last holder of this dentry lock, there is no |
4143 | * reason to downconvert so skip straight to the unlock. |
4144 | */ |
4145 | if (dl->dl_count == 1) |
4146 | return UNBLOCK_STOP_POST; |
4147 | |
4148 | return UNBLOCK_CONTINUE_POST; |
4149 | } |
4150 | |
4151 | static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres, |
4152 | int new_level) |
4153 | { |
4154 | struct ocfs2_refcount_tree *tree = |
4155 | ocfs2_lock_res_refcount_tree(res: lockres); |
4156 | |
4157 | return ocfs2_ci_checkpointed(ci: &tree->rf_ci, lockres, new_level); |
4158 | } |
4159 | |
4160 | static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres, |
4161 | int blocking) |
4162 | { |
4163 | struct ocfs2_refcount_tree *tree = |
4164 | ocfs2_lock_res_refcount_tree(res: lockres); |
4165 | |
4166 | ocfs2_metadata_cache_purge(ci: &tree->rf_ci); |
4167 | |
4168 | return UNBLOCK_CONTINUE; |
4169 | } |
4170 | |
4171 | static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres) |
4172 | { |
4173 | struct ocfs2_qinfo_lvb *lvb; |
4174 | struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres); |
4175 | struct mem_dqinfo *info = sb_dqinfo(sb: oinfo->dqi_gi.dqi_sb, |
4176 | type: oinfo->dqi_gi.dqi_type); |
4177 | |
4178 | lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
4179 | lvb->lvb_version = OCFS2_QINFO_LVB_VERSION; |
4180 | lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace); |
4181 | lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace); |
4182 | lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms); |
4183 | lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks); |
4184 | lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk); |
4185 | lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry); |
4186 | } |
4187 | |
4188 | void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex) |
4189 | { |
4190 | struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; |
4191 | struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); |
4192 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
4193 | |
4194 | if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) |
4195 | ocfs2_cluster_unlock(osb, lockres, level); |
4196 | } |
4197 | |
4198 | static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo) |
4199 | { |
4200 | struct mem_dqinfo *info = sb_dqinfo(sb: oinfo->dqi_gi.dqi_sb, |
4201 | type: oinfo->dqi_gi.dqi_type); |
4202 | struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; |
4203 | struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(lksb: &lockres->l_lksb); |
4204 | struct buffer_head *bh = NULL; |
4205 | struct ocfs2_global_disk_dqinfo *gdinfo; |
4206 | int status = 0; |
4207 | |
4208 | if (ocfs2_dlm_lvb_valid(lksb: &lockres->l_lksb) && |
4209 | lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) { |
4210 | info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace); |
4211 | info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace); |
4212 | oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms); |
4213 | oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks); |
4214 | oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk); |
4215 | oinfo->dqi_gi.dqi_free_entry = |
4216 | be32_to_cpu(lvb->lvb_free_entry); |
4217 | } else { |
4218 | status = ocfs2_read_quota_phys_block(inode: oinfo->dqi_gqinode, |
4219 | p_block: oinfo->dqi_giblk, bh: &bh); |
4220 | if (status) { |
4221 | mlog_errno(status); |
4222 | goto bail; |
4223 | } |
4224 | gdinfo = (struct ocfs2_global_disk_dqinfo *) |
4225 | (bh->b_data + OCFS2_GLOBAL_INFO_OFF); |
4226 | info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace); |
4227 | info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace); |
4228 | oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms); |
4229 | oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks); |
4230 | oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk); |
4231 | oinfo->dqi_gi.dqi_free_entry = |
4232 | le32_to_cpu(gdinfo->dqi_free_entry); |
4233 | brelse(bh); |
4234 | ocfs2_track_lock_refresh(lockres); |
4235 | } |
4236 | |
4237 | bail: |
4238 | return status; |
4239 | } |
4240 | |
4241 | /* Lock quota info, this function expects at least shared lock on the quota file |
4242 | * so that we can safely refresh quota info from disk. */ |
4243 | int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex) |
4244 | { |
4245 | struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; |
4246 | struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); |
4247 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
4248 | int status = 0; |
4249 | |
4250 | /* On RO devices, locking really isn't needed... */ |
4251 | if (ocfs2_is_hard_readonly(osb)) { |
4252 | if (ex) |
4253 | status = -EROFS; |
4254 | goto bail; |
4255 | } |
4256 | if (ocfs2_mount_local(osb)) |
4257 | goto bail; |
4258 | |
4259 | status = ocfs2_cluster_lock(osb, lockres, level, lkm_flags: 0, arg_flags: 0); |
4260 | if (status < 0) { |
4261 | mlog_errno(status); |
4262 | goto bail; |
4263 | } |
4264 | if (!ocfs2_should_refresh_lock_res(lockres)) |
4265 | goto bail; |
4266 | /* OK, we have the lock but we need to refresh the quota info */ |
4267 | status = ocfs2_refresh_qinfo(oinfo); |
4268 | if (status) |
4269 | ocfs2_qinfo_unlock(oinfo, ex); |
4270 | ocfs2_complete_lock_res_refresh(lockres, status); |
4271 | bail: |
4272 | return status; |
4273 | } |
4274 | |
4275 | int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex) |
4276 | { |
4277 | int status; |
4278 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
4279 | struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; |
4280 | struct ocfs2_super *osb = lockres->l_priv; |
4281 | |
4282 | |
4283 | if (ocfs2_is_hard_readonly(osb)) |
4284 | return -EROFS; |
4285 | |
4286 | if (ocfs2_mount_local(osb)) |
4287 | return 0; |
4288 | |
4289 | status = ocfs2_cluster_lock(osb, lockres, level, lkm_flags: 0, arg_flags: 0); |
4290 | if (status < 0) |
4291 | mlog_errno(status); |
4292 | |
4293 | return status; |
4294 | } |
4295 | |
4296 | void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex) |
4297 | { |
4298 | int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; |
4299 | struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; |
4300 | struct ocfs2_super *osb = lockres->l_priv; |
4301 | |
4302 | if (!ocfs2_mount_local(osb)) |
4303 | ocfs2_cluster_unlock(osb, lockres, level); |
4304 | } |
4305 | |
4306 | static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, |
4307 | struct ocfs2_lock_res *lockres) |
4308 | { |
4309 | int status; |
4310 | struct ocfs2_unblock_ctl ctl = {0, 0,}; |
4311 | unsigned long flags; |
4312 | |
4313 | /* Our reference to the lockres in this function can be |
4314 | * considered valid until we remove the OCFS2_LOCK_QUEUED |
4315 | * flag. */ |
4316 | |
4317 | BUG_ON(!lockres); |
4318 | BUG_ON(!lockres->l_ops); |
4319 | |
4320 | mlog(ML_BASTS, "lockres %s blocked\n" , lockres->l_name); |
4321 | |
4322 | /* Detect whether a lock has been marked as going away while |
4323 | * the downconvert thread was processing other things. A lock can |
4324 | * still be marked with OCFS2_LOCK_FREEING after this check, |
4325 | * but short circuiting here will still save us some |
4326 | * performance. */ |
4327 | spin_lock_irqsave(&lockres->l_lock, flags); |
4328 | if (lockres->l_flags & OCFS2_LOCK_FREEING) |
4329 | goto unqueue; |
4330 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
4331 | |
4332 | status = ocfs2_unblock_lock(osb, lockres, ctl: &ctl); |
4333 | if (status < 0) |
4334 | mlog_errno(status); |
4335 | |
4336 | spin_lock_irqsave(&lockres->l_lock, flags); |
4337 | unqueue: |
4338 | if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) { |
4339 | lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED); |
4340 | } else |
4341 | ocfs2_schedule_blocked_lock(osb, lockres); |
4342 | |
4343 | mlog(ML_BASTS, "lockres %s, requeue = %s.\n" , lockres->l_name, |
4344 | ctl.requeue ? "yes" : "no" ); |
4345 | spin_unlock_irqrestore(lock: &lockres->l_lock, flags); |
4346 | |
4347 | if (ctl.unblock_action != UNBLOCK_CONTINUE |
4348 | && lockres->l_ops->post_unlock) |
4349 | lockres->l_ops->post_unlock(osb, lockres); |
4350 | } |
4351 | |
4352 | static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, |
4353 | struct ocfs2_lock_res *lockres) |
4354 | { |
4355 | unsigned long flags; |
4356 | |
4357 | assert_spin_locked(&lockres->l_lock); |
4358 | |
4359 | if (lockres->l_flags & OCFS2_LOCK_FREEING) { |
4360 | /* Do not schedule a lock for downconvert when it's on |
4361 | * the way to destruction - any nodes wanting access |
4362 | * to the resource will get it soon. */ |
4363 | mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n" , |
4364 | lockres->l_name, lockres->l_flags); |
4365 | return; |
4366 | } |
4367 | |
4368 | lockres_or_flags(lockres, OCFS2_LOCK_QUEUED); |
4369 | |
4370 | spin_lock_irqsave(&osb->dc_task_lock, flags); |
4371 | if (list_empty(head: &lockres->l_blocked_list)) { |
4372 | list_add_tail(new: &lockres->l_blocked_list, |
4373 | head: &osb->blocked_lock_list); |
4374 | osb->blocked_lock_count++; |
4375 | } |
4376 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags); |
4377 | } |
4378 | |
4379 | static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb) |
4380 | { |
4381 | unsigned long processed; |
4382 | unsigned long flags; |
4383 | struct ocfs2_lock_res *lockres; |
4384 | |
4385 | spin_lock_irqsave(&osb->dc_task_lock, flags); |
4386 | /* grab this early so we know to try again if a state change and |
4387 | * wake happens part-way through our work */ |
4388 | osb->dc_work_sequence = osb->dc_wake_sequence; |
4389 | |
4390 | processed = osb->blocked_lock_count; |
4391 | /* |
4392 | * blocked lock processing in this loop might call iput which can |
4393 | * remove items off osb->blocked_lock_list. Downconvert up to |
4394 | * 'processed' number of locks, but stop short if we had some |
4395 | * removed in ocfs2_mark_lockres_freeing when downconverting. |
4396 | */ |
4397 | while (processed && !list_empty(head: &osb->blocked_lock_list)) { |
4398 | lockres = list_entry(osb->blocked_lock_list.next, |
4399 | struct ocfs2_lock_res, l_blocked_list); |
4400 | list_del_init(entry: &lockres->l_blocked_list); |
4401 | osb->blocked_lock_count--; |
4402 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags); |
4403 | |
4404 | BUG_ON(!processed); |
4405 | processed--; |
4406 | |
4407 | ocfs2_process_blocked_lock(osb, lockres); |
4408 | |
4409 | spin_lock_irqsave(&osb->dc_task_lock, flags); |
4410 | } |
4411 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags); |
4412 | } |
4413 | |
4414 | static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb) |
4415 | { |
4416 | int empty = 0; |
4417 | unsigned long flags; |
4418 | |
4419 | spin_lock_irqsave(&osb->dc_task_lock, flags); |
4420 | if (list_empty(head: &osb->blocked_lock_list)) |
4421 | empty = 1; |
4422 | |
4423 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags); |
4424 | return empty; |
4425 | } |
4426 | |
4427 | static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb) |
4428 | { |
4429 | int should_wake = 0; |
4430 | unsigned long flags; |
4431 | |
4432 | spin_lock_irqsave(&osb->dc_task_lock, flags); |
4433 | if (osb->dc_work_sequence != osb->dc_wake_sequence) |
4434 | should_wake = 1; |
4435 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags); |
4436 | |
4437 | return should_wake; |
4438 | } |
4439 | |
4440 | static int ocfs2_downconvert_thread(void *arg) |
4441 | { |
4442 | struct ocfs2_super *osb = arg; |
4443 | |
4444 | /* only quit once we've been asked to stop and there is no more |
4445 | * work available */ |
4446 | while (!(kthread_should_stop() && |
4447 | ocfs2_downconvert_thread_lists_empty(osb))) { |
4448 | |
4449 | wait_event_interruptible(osb->dc_event, |
4450 | ocfs2_downconvert_thread_should_wake(osb) || |
4451 | kthread_should_stop()); |
4452 | |
4453 | mlog(0, "downconvert_thread: awoken\n" ); |
4454 | |
4455 | ocfs2_downconvert_thread_do_work(osb); |
4456 | } |
4457 | |
4458 | osb->dc_task = NULL; |
4459 | return 0; |
4460 | } |
4461 | |
4462 | void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb) |
4463 | { |
4464 | unsigned long flags; |
4465 | |
4466 | spin_lock_irqsave(&osb->dc_task_lock, flags); |
4467 | /* make sure the voting thread gets a swipe at whatever changes |
4468 | * the caller may have made to the voting state */ |
4469 | osb->dc_wake_sequence++; |
4470 | spin_unlock_irqrestore(lock: &osb->dc_task_lock, flags); |
4471 | wake_up(&osb->dc_event); |
4472 | } |
4473 | |