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Merge git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / ocfs2 / dlmglue.c
CommitLineData
ccd979bd
MF		 1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmglue.c
5 *
6 * Code which implements an OCFS2 specific interface to our DLM.
7 *
8 * Copyright (C) 2003, 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26#include <linux/types.h>
27#include <linux/slab.h>
28#include <linux/highmem.h>
29#include <linux/mm.h>
ccd979bd
MF		 30#include <linux/crc32.h>
31#include <linux/kthread.h>
32#include <linux/pagemap.h>
33#include <linux/debugfs.h>
34#include <linux/seq_file.h>
35
36#include <cluster/heartbeat.h>
37#include <cluster/nodemanager.h>
38#include <cluster/tcp.h>
39
40#include <dlm/dlmapi.h>
41
42#define MLOG_MASK_PREFIX ML_DLM_GLUE
43#include <cluster/masklog.h>
44
45#include "ocfs2.h"
46
47#include "alloc.h"
d680efe9 48#include "dcache.h"
ccd979bd
MF		 49#include "dlmglue.h"
50#include "extent_map.h"
7f1a37e3 51#include "file.h"
ccd979bd
MF		 52#include "heartbeat.h"
53#include "inode.h"
54#include "journal.h"
55#include "slot_map.h"
56#include "super.h"
57#include "uptodate.h"
ccd979bd
MF		 58
59#include "buffer_head_io.h"
60
61struct ocfs2_mask_waiter {
62 struct list_head mw_item;
63 int mw_status;
64 struct completion mw_complete;
65 unsigned long mw_mask;
66 unsigned long mw_goal;
67};
68
54a7e755
MF		 69static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
70static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
cf8e06f1 71static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
ccd979bd 72
d680efe9 73/*
cc567d89 74 * Return value from ->downconvert_worker functions.
d680efe9 75 *
b5e500e2 76 * These control the precise actions of ocfs2_unblock_lock()
d680efe9
MF		 77 * and ocfs2_process_blocked_lock()
78 *
79 */
80enum ocfs2_unblock_action {
81 UNBLOCK_CONTINUE = 0, /* Continue downconvert */
82 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire
83 * ->post_unlock callback */
84 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire
85 * ->post_unlock() callback. */
86};
87
88struct ocfs2_unblock_ctl {
89 int requeue;
90 enum ocfs2_unblock_action unblock_action;
91};
92
810d5aeb
MF		 93static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
94 int new_level);
95static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
96
cc567d89
MF		 97static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
98 int blocking);
99
cc567d89
MF		 100static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
101 int blocking);
d680efe9
MF		 102
103static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
104 struct ocfs2_lock_res *lockres);
ccd979bd 105
6cb129f5
AB		 106
107#define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
108
109/* This aids in debugging situations where a bad LVB might be involved. */
110static void ocfs2_dump_meta_lvb_info(u64 level,
111 const char *function,
112 unsigned int line,
113 struct ocfs2_lock_res *lockres)
114{
115 struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
116
117 mlog(level, "LVB information for %s (called from %s:%u):\n",
118 lockres->l_name, function, line);
119 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n",
120 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters),
121 be32_to_cpu(lvb->lvb_igeneration));
122 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
123 (unsigned long long)be64_to_cpu(lvb->lvb_isize),
124 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
125 be16_to_cpu(lvb->lvb_imode));
126 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
127 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
128 (long long)be64_to_cpu(lvb->lvb_iatime_packed),
129 (long long)be64_to_cpu(lvb->lvb_ictime_packed),
130 (long long)be64_to_cpu(lvb->lvb_imtime_packed),
131 be32_to_cpu(lvb->lvb_iattr));
132}
133
134
f625c979
MF		 135/*
136 * OCFS2 Lock Resource Operations
137 *
138 * These fine tune the behavior of the generic dlmglue locking infrastructure.
0d5dc6c2
MF		 139 *
140 * The most basic of lock types can point ->l_priv to their respective
141 * struct ocfs2_super and allow the default actions to manage things.
142 *
143 * Right now, each lock type also needs to implement an init function,
144 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
145 * should be called when the lock is no longer needed (i.e., object
146 * destruction time).
f625c979 147 */
ccd979bd 148struct ocfs2_lock_res_ops {
54a7e755
MF		 149 /*
150 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
151 * this callback if ->l_priv is not an ocfs2_super pointer
152 */
153 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
b5e500e2 154
0d5dc6c2 155 /*
34d024f8
MF		 156 * Optionally called in the downconvert thread after a
157 * successful downconvert. The lockres will not be referenced
158 * after this callback is called, so it is safe to free
159 * memory, etc.
0d5dc6c2
MF		 160 *
161 * The exact semantics of when this is called are controlled
162 * by ->downconvert_worker()
163 */
d680efe9 164 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
f625c979 165
16d5b956
MF		 166 /*
167 * Allow a lock type to add checks to determine whether it is
168 * safe to downconvert a lock. Return 0 to re-queue the
169 * downconvert at a later time, nonzero to continue.
170 *
171 * For most locks, the default checks that there are no
172 * incompatible holders are sufficient.
173 *
174 * Called with the lockres spinlock held.
175 */
176 int (*check_downconvert)(struct ocfs2_lock_res *, int);
177
5ef0d4ea
MF		 178 /*
179 * Allows a lock type to populate the lock value block. This
180 * is called on downconvert, and when we drop a lock.
181 *
182 * Locks that want to use this should set LOCK_TYPE_USES_LVB
183 * in the flags field.
184 *
185 * Called with the lockres spinlock held.
186 */
187 void (*set_lvb)(struct ocfs2_lock_res *);
188
cc567d89
MF		 189 /*
190 * Called from the downconvert thread when it is determined
191 * that a lock will be downconverted. This is called without
192 * any locks held so the function can do work that might
193 * schedule (syncing out data, etc).
194 *
195 * This should return any one of the ocfs2_unblock_action
196 * values, depending on what it wants the thread to do.
197 */
198 int (*downconvert_worker)(struct ocfs2_lock_res *, int);
199
f625c979
MF		 200 /*
201 * LOCK_TYPE_* flags which describe the specific requirements
202 * of a lock type. Descriptions of each individual flag follow.
203 */
204 int flags;
ccd979bd
MF		 205};
206
f625c979
MF		 207/*
208 * Some locks want to "refresh" potentially stale data when a
209 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this
210 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the
211 * individual lockres l_flags member from the ast function. It is
212 * expected that the locking wrapper will clear the
213 * OCFS2_LOCK_NEEDS_REFRESH flag when done.
214 */
215#define LOCK_TYPE_REQUIRES_REFRESH 0x1
216
b80fc012 217/*
5ef0d4ea
MF		 218 * Indicate that a lock type makes use of the lock value block. The
219 * ->set_lvb lock type callback must be defined.
b80fc012
MF		 220 */
221#define LOCK_TYPE_USES_LVB 0x2
222
ccd979bd 223static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
54a7e755 224 .get_osb = ocfs2_get_inode_osb,
f625c979 225 .flags = 0,
ccd979bd
MF		 226};
227
e63aecb6 228static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
54a7e755 229 .get_osb = ocfs2_get_inode_osb,
810d5aeb
MF		 230 .check_downconvert = ocfs2_check_meta_downconvert,
231 .set_lvb = ocfs2_set_meta_lvb,
f1f54068 232 .downconvert_worker = ocfs2_data_convert_worker,
b80fc012 233 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
ccd979bd
MF		 234};
235
ccd979bd 236static struct ocfs2_lock_res_ops ocfs2_super_lops = {
f625c979 237 .flags = LOCK_TYPE_REQUIRES_REFRESH,
ccd979bd
MF		 238};
239
240static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
f625c979 241 .flags = 0,
ccd979bd
MF		 242};
243
d680efe9 244static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
54a7e755 245 .get_osb = ocfs2_get_dentry_osb,
d680efe9 246 .post_unlock = ocfs2_dentry_post_unlock,
cc567d89 247 .downconvert_worker = ocfs2_dentry_convert_worker,
f625c979 248 .flags = 0,
d680efe9
MF		 249};
250
50008630
TY		 251static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
252 .get_osb = ocfs2_get_inode_osb,
253 .flags = 0,
254};
255
cf8e06f1
MF		 256static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
257 .get_osb = ocfs2_get_file_osb,
258 .flags = 0,
259};
260
ccd979bd
MF		 261static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
262{
263 return lockres->l_type == OCFS2_LOCK_TYPE_META ||
50008630
TY		 264 lockres->l_type == OCFS2_LOCK_TYPE_RW ||
265 lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
ccd979bd
MF		 266}
267
ccd979bd
MF		 268static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
269{
270 BUG_ON(!ocfs2_is_inode_lock(lockres));
271
272 return (struct inode *) lockres->l_priv;
273}
274
d680efe9
MF		 275static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
276{
277 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
278
279 return (struct ocfs2_dentry_lock *)lockres->l_priv;
280}
281
54a7e755
MF		 282static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
283{
284 if (lockres->l_ops->get_osb)
285 return lockres->l_ops->get_osb(lockres);
286
287 return (struct ocfs2_super *)lockres->l_priv;
288}
289
ccd979bd
MF		 290static int ocfs2_lock_create(struct ocfs2_super *osb,
291 struct ocfs2_lock_res *lockres,
292 int level,
293 int dlm_flags);
294static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
295 int wanted);
296static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
297 struct ocfs2_lock_res *lockres,
298 int level);
299static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
300static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
301static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
302static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
303static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
304 struct ocfs2_lock_res *lockres);
305static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
306 int convert);
307#define ocfs2_log_dlm_error(_func, _stat, _lockres) do { \
308 mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on " \
309 "resource %s: %s\n", dlm_errname(_stat), _func, \
310 _lockres->l_name, dlm_errmsg(_stat)); \
311} while (0)
34d024f8
MF		 312static int ocfs2_downconvert_thread(void *arg);
313static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
314 struct ocfs2_lock_res *lockres);
e63aecb6 315static int ocfs2_inode_lock_update(struct inode *inode,
ccd979bd
MF		 316 struct buffer_head **bh);
317static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
318static inline int ocfs2_highest_compat_lock_level(int level);
cf8e06f1
MF		 319static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
320 int new_level);
321static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
322 struct ocfs2_lock_res *lockres,
323 int new_level,
324 int lvb);
325static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
326 struct ocfs2_lock_res *lockres);
327static int ocfs2_cancel_convert(struct ocfs2_super *osb,
328 struct ocfs2_lock_res *lockres);
329
ccd979bd 330
ccd979bd
MF		 331static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
332 u64 blkno,
333 u32 generation,
334 char *name)
335{
336 int len;
337
338 mlog_entry_void();
339
340 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
341
b0697053
MF		 342 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
343 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
344 (long long)blkno, generation);
ccd979bd
MF		 345
346 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
347
348 mlog(0, "built lock resource with name: %s\n", name);
349
350 mlog_exit_void();
351}
352
34af946a 353static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
ccd979bd
MF		 354
355static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
356 struct ocfs2_dlm_debug *dlm_debug)
357{
358 mlog(0, "Add tracking for lockres %s\n", res->l_name);
359
360 spin_lock(&ocfs2_dlm_tracking_lock);
361 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
362 spin_unlock(&ocfs2_dlm_tracking_lock);
363}
364
365static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
366{
367 spin_lock(&ocfs2_dlm_tracking_lock);
368 if (!list_empty(&res->l_debug_list))
369 list_del_init(&res->l_debug_list);
370 spin_unlock(&ocfs2_dlm_tracking_lock);
371}
372
373static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
374 struct ocfs2_lock_res *res,
375 enum ocfs2_lock_type type,
ccd979bd
MF		 376 struct ocfs2_lock_res_ops *ops,
377 void *priv)
378{
ccd979bd
MF		 379 res->l_type = type;
380 res->l_ops = ops;
381 res->l_priv = priv;
382
383 res->l_level = LKM_IVMODE;
384 res->l_requested = LKM_IVMODE;
385 res->l_blocking = LKM_IVMODE;
386 res->l_action = OCFS2_AST_INVALID;
387 res->l_unlock_action = OCFS2_UNLOCK_INVALID;
388
389 res->l_flags = OCFS2_LOCK_INITIALIZED;
390
391 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
392}
393
394void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
395{
396 /* This also clears out the lock status block */
397 memset(res, 0, sizeof(struct ocfs2_lock_res));
398 spin_lock_init(&res->l_lock);
399 init_waitqueue_head(&res->l_event);
400 INIT_LIST_HEAD(&res->l_blocked_list);
401 INIT_LIST_HEAD(&res->l_mask_waiters);
402}
403
404void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
405 enum ocfs2_lock_type type,
24c19ef4 406 unsigned int generation,
ccd979bd
MF		 407 struct inode *inode)
408{
409 struct ocfs2_lock_res_ops *ops;
410
411 switch(type) {
412 case OCFS2_LOCK_TYPE_RW:
413 ops = &ocfs2_inode_rw_lops;
414 break;
415 case OCFS2_LOCK_TYPE_META:
e63aecb6 416 ops = &ocfs2_inode_inode_lops;
ccd979bd 417 break;
50008630
TY		 418 case OCFS2_LOCK_TYPE_OPEN:
419 ops = &ocfs2_inode_open_lops;
420 break;
ccd979bd
MF		 421 default:
422 mlog_bug_on_msg(1, "type: %d\n", type);
423 ops = NULL; /* thanks, gcc */
424 break;
425 };
426
d680efe9 427 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
24c19ef4 428 generation, res->l_name);
d680efe9
MF		 429 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
430}
431
54a7e755
MF		 432static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
433{
434 struct inode *inode = ocfs2_lock_res_inode(lockres);
435
436 return OCFS2_SB(inode->i_sb);
437}
438
cf8e06f1
MF		 439static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
440{
441 struct ocfs2_file_private *fp = lockres->l_priv;
442
443 return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
444}
445
d680efe9
MF		 446static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
447{
448 __be64 inode_blkno_be;
449
450 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
451 sizeof(__be64));
452
453 return be64_to_cpu(inode_blkno_be);
454}
455
54a7e755
MF		 456static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
457{
458 struct ocfs2_dentry_lock *dl = lockres->l_priv;
459
460 return OCFS2_SB(dl->dl_inode->i_sb);
461}
462
d680efe9
MF		 463void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
464 u64 parent, struct inode *inode)
465{
466 int len;
467 u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
468 __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
469 struct ocfs2_lock_res *lockres = &dl->dl_lockres;
470
471 ocfs2_lock_res_init_once(lockres);
472
473 /*
474 * Unfortunately, the standard lock naming scheme won't work
475 * here because we have two 16 byte values to use. Instead,
476 * we'll stuff the inode number as a binary value. We still
477 * want error prints to show something without garbling the
478 * display, so drop a null byte in there before the inode
479 * number. A future version of OCFS2 will likely use all
480 * binary lock names. The stringified names have been a
481 * tremendous aid in debugging, but now that the debugfs
482 * interface exists, we can mangle things there if need be.
483 *
484 * NOTE: We also drop the standard "pad" value (the total lock
485 * name size stays the same though - the last part is all
486 * zeros due to the memset in ocfs2_lock_res_init_once()
487 */
488 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
489 "%c%016llx",
490 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
491 (long long)parent);
492
493 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
494
495 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
496 sizeof(__be64));
497
498 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
499 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
500 dl);
ccd979bd
MF		 501}
502
503static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
504 struct ocfs2_super *osb)
505{
506 /* Superblock lockres doesn't come from a slab so we call init
507 * once on it manually. */
508 ocfs2_lock_res_init_once(res);
d680efe9
MF		 509 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
510 0, res->l_name);
ccd979bd 511 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
ccd979bd
MF		 512 &ocfs2_super_lops, osb);
513}
514
515static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
516 struct ocfs2_super *osb)
517{
518 /* Rename lockres doesn't come from a slab so we call init
519 * once on it manually. */
520 ocfs2_lock_res_init_once(res);
d680efe9
MF		 521 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
522 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
ccd979bd
MF		 523 &ocfs2_rename_lops, osb);
524}
525
cf8e06f1
MF		 526void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
527 struct ocfs2_file_private *fp)
528{
529 struct inode *inode = fp->fp_file->f_mapping->host;
530 struct ocfs2_inode_info *oi = OCFS2_I(inode);
531
532 ocfs2_lock_res_init_once(lockres);
533 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
534 inode->i_generation, lockres->l_name);
535 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
536 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
537 fp);
538 lockres->l_flags |= OCFS2_LOCK_NOCACHE;
539}
540
ccd979bd
MF		 541void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
542{
543 mlog_entry_void();
544
545 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
546 return;
547
548 ocfs2_remove_lockres_tracking(res);
549
550 mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
551 "Lockres %s is on the blocked list\n",
552 res->l_name);
553 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
554 "Lockres %s has mask waiters pending\n",
555 res->l_name);
556 mlog_bug_on_msg(spin_is_locked(&res->l_lock),
557 "Lockres %s is locked\n",
558 res->l_name);
559 mlog_bug_on_msg(res->l_ro_holders,
560 "Lockres %s has %u ro holders\n",
561 res->l_name, res->l_ro_holders);
562 mlog_bug_on_msg(res->l_ex_holders,
563 "Lockres %s has %u ex holders\n",
564 res->l_name, res->l_ex_holders);
565
566 /* Need to clear out the lock status block for the dlm */
567 memset(&res->l_lksb, 0, sizeof(res->l_lksb));
568
569 res->l_flags = 0UL;
570 mlog_exit_void();
571}
572
573static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
574 int level)
575{
576 mlog_entry_void();
577
578 BUG_ON(!lockres);
579
580 switch(level) {
581 case LKM_EXMODE:
582 lockres->l_ex_holders++;
583 break;
584 case LKM_PRMODE:
585 lockres->l_ro_holders++;
586 break;
587 default:
588 BUG();
589 }
590
591 mlog_exit_void();
592}
593
594static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
595 int level)
596{
597 mlog_entry_void();
598
599 BUG_ON(!lockres);
600
601 switch(level) {
602 case LKM_EXMODE:
603 BUG_ON(!lockres->l_ex_holders);
604 lockres->l_ex_holders--;
605 break;
606 case LKM_PRMODE:
607 BUG_ON(!lockres->l_ro_holders);
608 lockres->l_ro_holders--;
609 break;
610 default:
611 BUG();
612 }
613 mlog_exit_void();
614}
615
616/* WARNING: This function lives in a world where the only three lock
617 * levels are EX, PR, and NL. It *will* have to be adjusted when more
618 * lock types are added. */
619static inline int ocfs2_highest_compat_lock_level(int level)
620{
621 int new_level = LKM_EXMODE;
622
623 if (level == LKM_EXMODE)
624 new_level = LKM_NLMODE;
625 else if (level == LKM_PRMODE)
626 new_level = LKM_PRMODE;
627 return new_level;
628}
629
630static void lockres_set_flags(struct ocfs2_lock_res *lockres,
631 unsigned long newflags)
632{
800deef3 633 struct ocfs2_mask_waiter *mw, *tmp;
ccd979bd
MF		 634
635 assert_spin_locked(&lockres->l_lock);
636
637 lockres->l_flags = newflags;
638
800deef3 639 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
ccd979bd
MF		 640 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
641 continue;
642
643 list_del_init(&mw->mw_item);
644 mw->mw_status = 0;
645 complete(&mw->mw_complete);
646 }
647}
648static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
649{
650 lockres_set_flags(lockres, lockres->l_flags | or);
651}
652static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
653 unsigned long clear)
654{
655 lockres_set_flags(lockres, lockres->l_flags & ~clear);
656}
657
658static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
659{
660 mlog_entry_void();
661
662 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
663 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
664 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
665 BUG_ON(lockres->l_blocking <= LKM_NLMODE);
666
667 lockres->l_level = lockres->l_requested;
668 if (lockres->l_level <=
669 ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
670 lockres->l_blocking = LKM_NLMODE;
671 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
672 }
673 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
674
675 mlog_exit_void();
676}
677
678static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
679{
680 mlog_entry_void();
681
682 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
683 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
684
685 /* Convert from RO to EX doesn't really need anything as our
686 * information is already up to data. Convert from NL to
687 * *anything* however should mark ourselves as needing an
688 * update */
f625c979
MF		 689 if (lockres->l_level == LKM_NLMODE &&
690 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
ccd979bd
MF		 691 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
692
693 lockres->l_level = lockres->l_requested;
694 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
695
696 mlog_exit_void();
697}
698
699static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
700{
701 mlog_entry_void();
702
3cf0c507 703 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
ccd979bd
MF		 704 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
705
706 if (lockres->l_requested > LKM_NLMODE &&
f625c979
MF		 707 !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
708 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
ccd979bd
MF		 709 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
710
711 lockres->l_level = lockres->l_requested;
712 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
713 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
714
715 mlog_exit_void();
716}
717
ccd979bd
MF		 718static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
719 int level)
720{
721 int needs_downconvert = 0;
722 mlog_entry_void();
723
724 assert_spin_locked(&lockres->l_lock);
725
726 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
727
728 if (level > lockres->l_blocking) {
729 /* only schedule a downconvert if we haven't already scheduled
730 * one that goes low enough to satisfy the level we're
731 * blocking. this also catches the case where we get
732 * duplicate BASTs */
733 if (ocfs2_highest_compat_lock_level(level) <
734 ocfs2_highest_compat_lock_level(lockres->l_blocking))
735 needs_downconvert = 1;
736
737 lockres->l_blocking = level;
738 }
739
740 mlog_exit(needs_downconvert);
741 return needs_downconvert;
742}
743
aa2623ad 744static void ocfs2_blocking_ast(void *opaque, int level)
ccd979bd 745{
aa2623ad
MF		 746 struct ocfs2_lock_res *lockres = opaque;
747 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
ccd979bd
MF		 748 int needs_downconvert;
749 unsigned long flags;
750
ccd979bd
MF		 751 BUG_ON(level <= LKM_NLMODE);
752
aa2623ad
MF		 753 mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n",
754 lockres->l_name, level, lockres->l_level,
755 ocfs2_lock_type_string(lockres->l_type));
756
cf8e06f1
MF		 757 /*
758 * We can skip the bast for locks which don't enable caching -
759 * they'll be dropped at the earliest possible time anyway.
760 */
761 if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
762 return;
763
ccd979bd
MF		 764 spin_lock_irqsave(&lockres->l_lock, flags);
765 needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
766 if (needs_downconvert)
767 ocfs2_schedule_blocked_lock(osb, lockres);
768 spin_unlock_irqrestore(&lockres->l_lock, flags);
769
d680efe9
MF		 770 wake_up(&lockres->l_event);
771
34d024f8 772 ocfs2_wake_downconvert_thread(osb);
ccd979bd
MF		 773}
774
e92d57df 775static void ocfs2_locking_ast(void *opaque)
ccd979bd 776{
e92d57df 777 struct ocfs2_lock_res *lockres = opaque;
ccd979bd
MF		 778 struct dlm_lockstatus *lksb = &lockres->l_lksb;
779 unsigned long flags;
780
781 spin_lock_irqsave(&lockres->l_lock, flags);
782
783 if (lksb->status != DLM_NORMAL) {
784 mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n",
785 lockres->l_name, lksb->status);
786 spin_unlock_irqrestore(&lockres->l_lock, flags);
787 return;
788 }
789
790 switch(lockres->l_action) {
791 case OCFS2_AST_ATTACH:
792 ocfs2_generic_handle_attach_action(lockres);
e92d57df 793 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
ccd979bd
MF		 794 break;
795 case OCFS2_AST_CONVERT:
796 ocfs2_generic_handle_convert_action(lockres);
797 break;
798 case OCFS2_AST_DOWNCONVERT:
799 ocfs2_generic_handle_downconvert_action(lockres);
800 break;
801 default:
e92d57df
MF		 802 mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u "
803 "lockres flags = 0x%lx, unlock action: %u\n",
804 lockres->l_name, lockres->l_action, lockres->l_flags,
805 lockres->l_unlock_action);
ccd979bd
MF		 806 BUG();
807 }
808
ccd979bd
MF		 809 /* set it to something invalid so if we get called again we
810 * can catch it. */
811 lockres->l_action = OCFS2_AST_INVALID;
ccd979bd
MF		 812
813 wake_up(&lockres->l_event);
d680efe9 814 spin_unlock_irqrestore(&lockres->l_lock, flags);
ccd979bd
MF		 815}
816
ccd979bd
MF		 817static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
818 int convert)
819{
820 unsigned long flags;
821
822 mlog_entry_void();
823 spin_lock_irqsave(&lockres->l_lock, flags);
824 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
825 if (convert)
826 lockres->l_action = OCFS2_AST_INVALID;
827 else
828 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
829 spin_unlock_irqrestore(&lockres->l_lock, flags);
830
831 wake_up(&lockres->l_event);
832 mlog_exit_void();
833}
834
835/* Note: If we detect another process working on the lock (i.e.,
836 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
837 * to do the right thing in that case.
838 */
839static int ocfs2_lock_create(struct ocfs2_super *osb,
840 struct ocfs2_lock_res *lockres,
841 int level,
842 int dlm_flags)
843{
844 int ret = 0;
c271c5c2 845 enum dlm_status status = DLM_NORMAL;
ccd979bd
MF		 846 unsigned long flags;
847
848 mlog_entry_void();
849
850 mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level,
851 dlm_flags);
852
853 spin_lock_irqsave(&lockres->l_lock, flags);
854 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
855 (lockres->l_flags & OCFS2_LOCK_BUSY)) {
856 spin_unlock_irqrestore(&lockres->l_lock, flags);
857 goto bail;
858 }
859
860 lockres->l_action = OCFS2_AST_ATTACH;
861 lockres->l_requested = level;
862 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
863 spin_unlock_irqrestore(&lockres->l_lock, flags);
864
865 status = dlmlock(osb->dlm,
866 level,
867 &lockres->l_lksb,
868 dlm_flags,
869 lockres->l_name,
f0681062 870 OCFS2_LOCK_ID_MAX_LEN - 1,
e92d57df 871 ocfs2_locking_ast,
ccd979bd 872 lockres,
aa2623ad 873 ocfs2_blocking_ast);
ccd979bd
MF		 874 if (status != DLM_NORMAL) {
875 ocfs2_log_dlm_error("dlmlock", status, lockres);
876 ret = -EINVAL;
877 ocfs2_recover_from_dlm_error(lockres, 1);
878 }
879
880 mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name);
881
882bail:
883 mlog_exit(ret);
884 return ret;
885}
886
887static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
888 int flag)
889{
890 unsigned long flags;
891 int ret;
892
893 spin_lock_irqsave(&lockres->l_lock, flags);
894 ret = lockres->l_flags & flag;
895 spin_unlock_irqrestore(&lockres->l_lock, flags);
896
897 return ret;
898}
899
900static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
901
902{
903 wait_event(lockres->l_event,
904 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
905}
906
907static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
908
909{
910 wait_event(lockres->l_event,
911 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
912}
913
914/* predict what lock level we'll be dropping down to on behalf
915 * of another node, and return true if the currently wanted
916 * level will be compatible with it. */
917static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
918 int wanted)
919{
920 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
921
922 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
923}
924
925static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
926{
927 INIT_LIST_HEAD(&mw->mw_item);
928 init_completion(&mw->mw_complete);
929}
930
931static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
932{
933 wait_for_completion(&mw->mw_complete);
934 /* Re-arm the completion in case we want to wait on it again */
935 INIT_COMPLETION(mw->mw_complete);
936 return mw->mw_status;
937}
938
939static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
940 struct ocfs2_mask_waiter *mw,
941 unsigned long mask,
942 unsigned long goal)
943{
944 BUG_ON(!list_empty(&mw->mw_item));
945
946 assert_spin_locked(&lockres->l_lock);
947
948 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
949 mw->mw_mask = mask;
950 mw->mw_goal = goal;
951}
952
953/* returns 0 if the mw that was removed was already satisfied, -EBUSY
954 * if the mask still hadn't reached its goal */
955static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
956 struct ocfs2_mask_waiter *mw)
957{
958 unsigned long flags;
959 int ret = 0;
960
961 spin_lock_irqsave(&lockres->l_lock, flags);
962 if (!list_empty(&mw->mw_item)) {
963 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
964 ret = -EBUSY;
965
966 list_del_init(&mw->mw_item);
967 init_completion(&mw->mw_complete);
968 }
969 spin_unlock_irqrestore(&lockres->l_lock, flags);
970
971 return ret;
972
973}
974
cf8e06f1
MF		 975static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
976 struct ocfs2_lock_res *lockres)
977{
978 int ret;
979
980 ret = wait_for_completion_interruptible(&mw->mw_complete);
981 if (ret)
982 lockres_remove_mask_waiter(lockres, mw);
983 else
984 ret = mw->mw_status;
985 /* Re-arm the completion in case we want to wait on it again */
986 INIT_COMPLETION(mw->mw_complete);
987 return ret;
988}
989
ccd979bd
MF		 990static int ocfs2_cluster_lock(struct ocfs2_super *osb,
991 struct ocfs2_lock_res *lockres,
992 int level,
993 int lkm_flags,
994 int arg_flags)
995{
996 struct ocfs2_mask_waiter mw;
997 enum dlm_status status;
998 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
999 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
1000 unsigned long flags;
1001
1002 mlog_entry_void();
1003
1004 ocfs2_init_mask_waiter(&mw);
1005
b80fc012
MF		 1006 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
1007 lkm_flags |= LKM_VALBLK;
1008
ccd979bd
MF		 1009again:
1010 wait = 0;
1011
1012 if (catch_signals && signal_pending(current)) {
1013 ret = -ERESTARTSYS;
1014 goto out;
1015 }
1016
1017 spin_lock_irqsave(&lockres->l_lock, flags);
1018
1019 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
1020 "Cluster lock called on freeing lockres %s! flags "
1021 "0x%lx\n", lockres->l_name, lockres->l_flags);
1022
1023 /* We only compare against the currently granted level
1024 * here. If the lock is blocked waiting on a downconvert,
1025 * we'll get caught below. */
1026 if (lockres->l_flags & OCFS2_LOCK_BUSY &&
1027 level > lockres->l_level) {
1028 /* is someone sitting in dlm_lock? If so, wait on
1029 * them. */
1030 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1031 wait = 1;
1032 goto unlock;
1033 }
1034
ccd979bd
MF		 1035 if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
1036 !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
1037 /* is the lock is currently blocked on behalf of
1038 * another node */
1039 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
1040 wait = 1;
1041 goto unlock;
1042 }
1043
1044 if (level > lockres->l_level) {
1045 if (lockres->l_action != OCFS2_AST_INVALID)
1046 mlog(ML_ERROR, "lockres %s has action %u pending\n",
1047 lockres->l_name, lockres->l_action);
1048
019d1b22
MF		 1049 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1050 lockres->l_action = OCFS2_AST_ATTACH;
1051 lkm_flags &= ~LKM_CONVERT;
1052 } else {
1053 lockres->l_action = OCFS2_AST_CONVERT;
1054 lkm_flags |= LKM_CONVERT;
1055 }
1056
ccd979bd
MF		 1057 lockres->l_requested = level;
1058 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1059 spin_unlock_irqrestore(&lockres->l_lock, flags);
1060
1061 BUG_ON(level == LKM_IVMODE);
1062 BUG_ON(level == LKM_NLMODE);
1063
1064 mlog(0, "lock %s, convert from %d to level = %d\n",
1065 lockres->l_name, lockres->l_level, level);
1066
1067 /* call dlm_lock to upgrade lock now */
1068 status = dlmlock(osb->dlm,
1069 level,
1070 &lockres->l_lksb,
019d1b22 1071 lkm_flags,
ccd979bd 1072 lockres->l_name,
f0681062 1073 OCFS2_LOCK_ID_MAX_LEN - 1,
e92d57df 1074 ocfs2_locking_ast,
ccd979bd 1075 lockres,
aa2623ad 1076 ocfs2_blocking_ast);
ccd979bd
MF		 1077 if (status != DLM_NORMAL) {
1078 if ((lkm_flags & LKM_NOQUEUE) &&
1079 (status == DLM_NOTQUEUED))
1080 ret = -EAGAIN;
1081 else {
1082 ocfs2_log_dlm_error("dlmlock", status,
1083 lockres);
1084 ret = -EINVAL;
1085 }
1086 ocfs2_recover_from_dlm_error(lockres, 1);
1087 goto out;
1088 }
1089
1090 mlog(0, "lock %s, successfull return from dlmlock\n",
1091 lockres->l_name);
1092
1093 /* At this point we've gone inside the dlm and need to
1094 * complete our work regardless. */
1095 catch_signals = 0;
1096
1097 /* wait for busy to clear and carry on */
1098 goto again;
1099 }
1100
1101 /* Ok, if we get here then we're good to go. */
1102 ocfs2_inc_holders(lockres, level);
1103
1104 ret = 0;
1105unlock:
1106 spin_unlock_irqrestore(&lockres->l_lock, flags);
1107out:
1108 /*
1109 * This is helping work around a lock inversion between the page lock
1110 * and dlm locks. One path holds the page lock while calling aops
1111 * which block acquiring dlm locks. The voting thread holds dlm
1112 * locks while acquiring page locks while down converting data locks.
1113 * This block is helping an aop path notice the inversion and back
1114 * off to unlock its page lock before trying the dlm lock again.
1115 */
1116 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
1117 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
1118 wait = 0;
1119 if (lockres_remove_mask_waiter(lockres, &mw))
1120 ret = -EAGAIN;
1121 else
1122 goto again;
1123 }
1124 if (wait) {
1125 ret = ocfs2_wait_for_mask(&mw);
1126 if (ret == 0)
1127 goto again;
1128 mlog_errno(ret);
1129 }
1130
1131 mlog_exit(ret);
1132 return ret;
1133}
1134
1135static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
1136 struct ocfs2_lock_res *lockres,
1137 int level)
1138{
1139 unsigned long flags;
1140
1141 mlog_entry_void();
1142 spin_lock_irqsave(&lockres->l_lock, flags);
1143 ocfs2_dec_holders(lockres, level);
34d024f8 1144 ocfs2_downconvert_on_unlock(osb, lockres);
ccd979bd
MF		 1145 spin_unlock_irqrestore(&lockres->l_lock, flags);
1146 mlog_exit_void();
1147}
1148
da66116e
AB		 1149static int ocfs2_create_new_lock(struct ocfs2_super *osb,
1150 struct ocfs2_lock_res *lockres,
1151 int ex,
1152 int local)
ccd979bd 1153{
d680efe9 1154 int level = ex ? LKM_EXMODE : LKM_PRMODE;
ccd979bd 1155 unsigned long flags;
24c19ef4 1156 int lkm_flags = local ? LKM_LOCAL : 0;
ccd979bd
MF		 1157
1158 spin_lock_irqsave(&lockres->l_lock, flags);
1159 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
1160 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
1161 spin_unlock_irqrestore(&lockres->l_lock, flags);
1162
24c19ef4 1163 return ocfs2_lock_create(osb, lockres, level, lkm_flags);
ccd979bd
MF		 1164}
1165
1166/* Grants us an EX lock on the data and metadata resources, skipping
1167 * the normal cluster directory lookup. Use this ONLY on newly created
1168 * inodes which other nodes can't possibly see, and which haven't been
1169 * hashed in the inode hash yet. This can give us a good performance
1170 * increase as it'll skip the network broadcast normally associated
1171 * with creating a new lock resource. */
1172int ocfs2_create_new_inode_locks(struct inode *inode)
1173{
1174 int ret;
d680efe9 1175 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ccd979bd
MF		 1176
1177 BUG_ON(!inode);
1178 BUG_ON(!ocfs2_inode_is_new(inode));
1179
1180 mlog_entry_void();
1181
b0697053 1182 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
ccd979bd
MF		 1183
1184 /* NOTE: That we don't increment any of the holder counts, nor
1185 * do we add anything to a journal handle. Since this is
1186 * supposed to be a new inode which the cluster doesn't know
1187 * about yet, there is no need to. As far as the LVB handling
1188 * is concerned, this is basically like acquiring an EX lock
1189 * on a resource which has an invalid one -- we'll set it
1190 * valid when we release the EX. */
1191
24c19ef4 1192 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
ccd979bd
MF		 1193 if (ret) {
1194 mlog_errno(ret);
1195 goto bail;
1196 }
1197
24c19ef4
MF		 1198 /*
1199 * We don't want to use LKM_LOCAL on a meta data lock as they
1200 * don't use a generation in their lock names.
1201 */
e63aecb6 1202 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
ccd979bd
MF		 1203 if (ret) {
1204 mlog_errno(ret);
1205 goto bail;
1206 }
1207
50008630
TY		 1208 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
1209 if (ret) {
1210 mlog_errno(ret);
1211 goto bail;
1212 }
1213
ccd979bd
MF		 1214bail:
1215 mlog_exit(ret);
1216 return ret;
1217}
1218
1219int ocfs2_rw_lock(struct inode *inode, int write)
1220{
1221 int status, level;
1222 struct ocfs2_lock_res *lockres;
c271c5c2 1223 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ccd979bd
MF		 1224
1225 BUG_ON(!inode);
1226
1227 mlog_entry_void();
1228
b0697053
MF		 1229 mlog(0, "inode %llu take %s RW lock\n",
1230 (unsigned long long)OCFS2_I(inode)->ip_blkno,
ccd979bd
MF		 1231 write ? "EXMODE" : "PRMODE");
1232
c271c5c2
SM		 1233 if (ocfs2_mount_local(osb))
1234 return 0;
1235
ccd979bd
MF		 1236 lockres = &OCFS2_I(inode)->ip_rw_lockres;
1237
1238 level = write ? LKM_EXMODE : LKM_PRMODE;
1239
1240 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
1241 0);
1242 if (status < 0)
1243 mlog_errno(status);
1244
1245 mlog_exit(status);
1246 return status;
1247}
1248
1249void ocfs2_rw_unlock(struct inode *inode, int write)
1250{
1251 int level = write ? LKM_EXMODE : LKM_PRMODE;
1252 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
c271c5c2 1253 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ccd979bd
MF		 1254
1255 mlog_entry_void();
1256
b0697053
MF		 1257 mlog(0, "inode %llu drop %s RW lock\n",
1258 (unsigned long long)OCFS2_I(inode)->ip_blkno,
ccd979bd
MF		 1259 write ? "EXMODE" : "PRMODE");
1260
c271c5c2
SM		 1261 if (!ocfs2_mount_local(osb))
1262 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
ccd979bd
MF		 1263
1264 mlog_exit_void();
1265}
1266
50008630
TY		 1267/*
1268 * ocfs2_open_lock always get PR mode lock.
1269 */
1270int ocfs2_open_lock(struct inode *inode)
1271{
1272 int status = 0;
1273 struct ocfs2_lock_res *lockres;
1274 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1275
1276 BUG_ON(!inode);
1277
1278 mlog_entry_void();
1279
1280 mlog(0, "inode %llu take PRMODE open lock\n",
1281 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1282
1283 if (ocfs2_mount_local(osb))
1284 goto out;
1285
1286 lockres = &OCFS2_I(inode)->ip_open_lockres;
1287
1288 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
1289 LKM_PRMODE, 0, 0);
1290 if (status < 0)
1291 mlog_errno(status);
1292
1293out:
1294 mlog_exit(status);
1295 return status;
1296}
1297
1298int ocfs2_try_open_lock(struct inode *inode, int write)
1299{
1300 int status = 0, level;
1301 struct ocfs2_lock_res *lockres;
1302 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1303
1304 BUG_ON(!inode);
1305
1306 mlog_entry_void();
1307
1308 mlog(0, "inode %llu try to take %s open lock\n",
1309 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1310 write ? "EXMODE" : "PRMODE");
1311
1312 if (ocfs2_mount_local(osb))
1313 goto out;
1314
1315 lockres = &OCFS2_I(inode)->ip_open_lockres;
1316
1317 level = write ? LKM_EXMODE : LKM_PRMODE;
1318
1319 /*
1320 * The file system may already holding a PRMODE/EXMODE open lock.
1321 * Since we pass LKM_NOQUEUE, the request won't block waiting on
1322 * other nodes and the -EAGAIN will indicate to the caller that
1323 * this inode is still in use.
1324 */
1325 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
1326 level, LKM_NOQUEUE, 0);
1327
1328out:
1329 mlog_exit(status);
1330 return status;
1331}
1332
1333/*
1334 * ocfs2_open_unlock unlock PR and EX mode open locks.
1335 */
1336void ocfs2_open_unlock(struct inode *inode)
1337{
1338 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
1339 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1340
1341 mlog_entry_void();
1342
1343 mlog(0, "inode %llu drop open lock\n",
1344 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1345
1346 if (ocfs2_mount_local(osb))
1347 goto out;
1348
1349 if(lockres->l_ro_holders)
1350 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
1351 LKM_PRMODE);
1352 if(lockres->l_ex_holders)
1353 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
1354 LKM_EXMODE);
1355
1356out:
1357 mlog_exit_void();
1358}
1359
cf8e06f1
MF		 1360static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
1361 int level)
1362{
1363 int ret;
1364 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
1365 unsigned long flags;
1366 struct ocfs2_mask_waiter mw;
1367
1368 ocfs2_init_mask_waiter(&mw);
1369
1370retry_cancel:
1371 spin_lock_irqsave(&lockres->l_lock, flags);
1372 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
1373 ret = ocfs2_prepare_cancel_convert(osb, lockres);
1374 if (ret) {
1375 spin_unlock_irqrestore(&lockres->l_lock, flags);
1376 ret = ocfs2_cancel_convert(osb, lockres);
1377 if (ret < 0) {
1378 mlog_errno(ret);
1379 goto out;
1380 }
1381 goto retry_cancel;
1382 }
1383 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1384 spin_unlock_irqrestore(&lockres->l_lock, flags);
1385
1386 ocfs2_wait_for_mask(&mw);
1387 goto retry_cancel;
1388 }
1389
1390 ret = -ERESTARTSYS;
1391 /*
1392 * We may still have gotten the lock, in which case there's no
1393 * point to restarting the syscall.
1394 */
1395 if (lockres->l_level == level)
1396 ret = 0;
1397
1398 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
1399 lockres->l_flags, lockres->l_level, lockres->l_action);
1400
1401 spin_unlock_irqrestore(&lockres->l_lock, flags);
1402
1403out:
1404 return ret;
1405}
1406
1407/*
1408 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
1409 * flock() calls. The locking approach this requires is sufficiently
1410 * different from all other cluster lock types that we implement a
1411 * seperate path to the "low-level" dlm calls. In particular:
1412 *
1413 * - No optimization of lock levels is done - we take at exactly
1414 * what's been requested.
1415 *
1416 * - No lock caching is employed. We immediately downconvert to
1417 * no-lock at unlock time. This also means flock locks never go on
1418 * the blocking list).
1419 *
1420 * - Since userspace can trivially deadlock itself with flock, we make
1421 * sure to allow cancellation of a misbehaving applications flock()
1422 * request.
1423 *
1424 * - Access to any flock lockres doesn't require concurrency, so we
1425 * can simplify the code by requiring the caller to guarantee
1426 * serialization of dlmglue flock calls.
1427 */
1428int ocfs2_file_lock(struct file *file, int ex, int trylock)
1429{
1430 int ret, level = ex ? LKM_EXMODE : LKM_PRMODE;
1431 unsigned int lkm_flags = trylock ? LKM_NOQUEUE : 0;
1432 unsigned long flags;
1433 struct ocfs2_file_private *fp = file->private_data;
1434 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1435 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1436 struct ocfs2_mask_waiter mw;
1437
1438 ocfs2_init_mask_waiter(&mw);
1439
1440 if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
1441 (lockres->l_level > LKM_NLMODE)) {
1442 mlog(ML_ERROR,
1443 "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
1444 "level: %u\n", lockres->l_name, lockres->l_flags,
1445 lockres->l_level);
1446 return -EINVAL;
1447 }
1448
1449 spin_lock_irqsave(&lockres->l_lock, flags);
1450 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
1451 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1452 spin_unlock_irqrestore(&lockres->l_lock, flags);
1453
1454 /*
1455 * Get the lock at NLMODE to start - that way we
1456 * can cancel the upconvert request if need be.
1457 */
1458 ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
1459 if (ret < 0) {
1460 mlog_errno(ret);
1461 goto out;
1462 }
1463
1464 ret = ocfs2_wait_for_mask(&mw);
1465 if (ret) {
1466 mlog_errno(ret);
1467 goto out;
1468 }
1469 spin_lock_irqsave(&lockres->l_lock, flags);
1470 }
1471
1472 lockres->l_action = OCFS2_AST_CONVERT;
1473 lkm_flags |= LKM_CONVERT;
1474 lockres->l_requested = level;
1475 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1476
1477 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1478 spin_unlock_irqrestore(&lockres->l_lock, flags);
1479
1480 ret = dlmlock(osb->dlm, level, &lockres->l_lksb, lkm_flags,
1481 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1,
1482 ocfs2_locking_ast, lockres, ocfs2_blocking_ast);
1483 if (ret != DLM_NORMAL) {
1484 if (trylock && ret == DLM_NOTQUEUED)
1485 ret = -EAGAIN;
1486 else {
1487 ocfs2_log_dlm_error("dlmlock", ret, lockres);
1488 ret = -EINVAL;
1489 }
1490
1491 ocfs2_recover_from_dlm_error(lockres, 1);
1492 lockres_remove_mask_waiter(lockres, &mw);
1493 goto out;
1494 }
1495
1496 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
1497 if (ret == -ERESTARTSYS) {
1498 /*
1499 * Userspace can cause deadlock itself with
1500 * flock(). Current behavior locally is to allow the
1501 * deadlock, but abort the system call if a signal is
1502 * received. We follow this example, otherwise a
1503 * poorly written program could sit in kernel until
1504 * reboot.
1505 *
1506 * Handling this is a bit more complicated for Ocfs2
1507 * though. We can't exit this function with an
1508 * outstanding lock request, so a cancel convert is
1509 * required. We intentionally overwrite 'ret' - if the
1510 * cancel fails and the lock was granted, it's easier
1511 * to just bubble sucess back up to the user.
1512 */
1513 ret = ocfs2_flock_handle_signal(lockres, level);
1514 }
1515
1516out:
1517
1518 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
1519 lockres->l_name, ex, trylock, ret);
1520 return ret;
1521}
1522
1523void ocfs2_file_unlock(struct file *file)
1524{
1525 int ret;
1526 unsigned long flags;
1527 struct ocfs2_file_private *fp = file->private_data;
1528 struct ocfs2_lock_res *lockres = &fp->fp_flock;
1529 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
1530 struct ocfs2_mask_waiter mw;
1531
1532 ocfs2_init_mask_waiter(&mw);
1533
1534 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
1535 return;
1536
1537 if (lockres->l_level == LKM_NLMODE)
1538 return;
1539
1540 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
1541 lockres->l_name, lockres->l_flags, lockres->l_level,
1542 lockres->l_action);
1543
1544 spin_lock_irqsave(&lockres->l_lock, flags);
1545 /*
1546 * Fake a blocking ast for the downconvert code.
1547 */
1548 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
1549 lockres->l_blocking = LKM_EXMODE;
1550
1551 ocfs2_prepare_downconvert(lockres, LKM_NLMODE);
1552 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
1553 spin_unlock_irqrestore(&lockres->l_lock, flags);
1554
1555 ret = ocfs2_downconvert_lock(osb, lockres, LKM_NLMODE, 0);
1556 if (ret) {
1557 mlog_errno(ret);
1558 return;
1559 }
1560
1561 ret = ocfs2_wait_for_mask(&mw);
1562 if (ret)
1563 mlog_errno(ret);
1564}
1565
34d024f8
MF		 1566static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
1567 struct ocfs2_lock_res *lockres)
ccd979bd
MF		 1568{
1569 int kick = 0;
1570
1571 mlog_entry_void();
1572
1573 /* If we know that another node is waiting on our lock, kick
34d024f8 1574 * the downconvert thread * pre-emptively when we reach a release
ccd979bd
MF		 1575 * condition. */
1576 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
1577 switch(lockres->l_blocking) {
1578 case LKM_EXMODE:
1579 if (!lockres->l_ex_holders && !lockres->l_ro_holders)
1580 kick = 1;
1581 break;
1582 case LKM_PRMODE:
1583 if (!lockres->l_ex_holders)
1584 kick = 1;
1585 break;
1586 default:
1587 BUG();
1588 }
1589 }
1590
1591 if (kick)
34d024f8 1592 ocfs2_wake_downconvert_thread(osb);
ccd979bd
MF		 1593
1594 mlog_exit_void();
1595}
1596
ccd979bd
MF		 1597#define OCFS2_SEC_BITS 34
1598#define OCFS2_SEC_SHIFT (64 - 34)
1599#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
1600
1601/* LVB only has room for 64 bits of time here so we pack it for
1602 * now. */
1603static u64 ocfs2_pack_timespec(struct timespec *spec)
1604{
1605 u64 res;
1606 u64 sec = spec->tv_sec;
1607 u32 nsec = spec->tv_nsec;
1608
1609 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
1610
1611 return res;
1612}
1613
1614/* Call this with the lockres locked. I am reasonably sure we don't
1615 * need ip_lock in this function as anyone who would be changing those
e63aecb6 1616 * values is supposed to be blocked in ocfs2_inode_lock right now. */
ccd979bd
MF		 1617static void __ocfs2_stuff_meta_lvb(struct inode *inode)
1618{
1619 struct ocfs2_inode_info *oi = OCFS2_I(inode);
e63aecb6 1620 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
ccd979bd
MF		 1621 struct ocfs2_meta_lvb *lvb;
1622
1623 mlog_entry_void();
1624
1625 lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
1626
24c19ef4
MF		 1627 /*
1628 * Invalidate the LVB of a deleted inode - this way other
1629 * nodes are forced to go to disk and discover the new inode
1630 * status.
1631 */
1632 if (oi->ip_flags & OCFS2_INODE_DELETED) {
1633 lvb->lvb_version = 0;
1634 goto out;
1635 }
1636
4d3b83f7 1637 lvb->lvb_version = OCFS2_LVB_VERSION;
ccd979bd
MF		 1638 lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
1639 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
1640 lvb->lvb_iuid = cpu_to_be32(inode->i_uid);
1641 lvb->lvb_igid = cpu_to_be32(inode->i_gid);
1642 lvb->lvb_imode = cpu_to_be16(inode->i_mode);
1643 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
1644 lvb->lvb_iatime_packed =
1645 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
1646 lvb->lvb_ictime_packed =
1647 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
1648 lvb->lvb_imtime_packed =
1649 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
ca4d147e 1650 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
15b1e36b 1651 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
f9e2d82e 1652 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
ccd979bd 1653
24c19ef4 1654out:
ccd979bd
MF		 1655 mlog_meta_lvb(0, lockres);
1656
1657 mlog_exit_void();
1658}
1659
1660static void ocfs2_unpack_timespec(struct timespec *spec,
1661 u64 packed_time)
1662{
1663 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
1664 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
1665}
1666
1667static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
1668{
1669 struct ocfs2_inode_info *oi = OCFS2_I(inode);
e63aecb6 1670 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
ccd979bd
MF		 1671 struct ocfs2_meta_lvb *lvb;
1672
1673 mlog_entry_void();
1674
1675 mlog_meta_lvb(0, lockres);
1676
1677 lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
1678
1679 /* We're safe here without the lockres lock... */
1680 spin_lock(&oi->ip_lock);
1681 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
1682 i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
1683
ca4d147e 1684 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
15b1e36b 1685 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
ca4d147e
HP		 1686 ocfs2_set_inode_flags(inode);
1687
ccd979bd
MF		 1688 /* fast-symlinks are a special case */
1689 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
1690 inode->i_blocks = 0;
1691 else
8110b073 1692 inode->i_blocks = ocfs2_inode_sector_count(inode);
ccd979bd
MF		 1693
1694 inode->i_uid = be32_to_cpu(lvb->lvb_iuid);
1695 inode->i_gid = be32_to_cpu(lvb->lvb_igid);
1696 inode->i_mode = be16_to_cpu(lvb->lvb_imode);
1697 inode->i_nlink = be16_to_cpu(lvb->lvb_inlink);
1698 ocfs2_unpack_timespec(&inode->i_atime,
1699 be64_to_cpu(lvb->lvb_iatime_packed));
1700 ocfs2_unpack_timespec(&inode->i_mtime,
1701 be64_to_cpu(lvb->lvb_imtime_packed));
1702 ocfs2_unpack_timespec(&inode->i_ctime,
1703 be64_to_cpu(lvb->lvb_ictime_packed));
1704 spin_unlock(&oi->ip_lock);
1705
1706 mlog_exit_void();
1707}
1708
f9e2d82e
MF		 1709static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
1710 struct ocfs2_lock_res *lockres)
ccd979bd
MF		 1711{
1712 struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
1713
f9e2d82e
MF		 1714 if (lvb->lvb_version == OCFS2_LVB_VERSION
1715 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
ccd979bd
MF		 1716 return 1;
1717 return 0;
1718}
1719
1720/* Determine whether a lock resource needs to be refreshed, and
1721 * arbitrate who gets to refresh it.
1722 *
1723 * 0 means no refresh needed.
1724 *
1725 * > 0 means you need to refresh this and you MUST call
1726 * ocfs2_complete_lock_res_refresh afterwards. */
1727static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
1728{
1729 unsigned long flags;
1730 int status = 0;
1731
1732 mlog_entry_void();
1733
1734refresh_check:
1735 spin_lock_irqsave(&lockres->l_lock, flags);
1736 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
1737 spin_unlock_irqrestore(&lockres->l_lock, flags);
1738 goto bail;
1739 }
1740
1741 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
1742 spin_unlock_irqrestore(&lockres->l_lock, flags);
1743
1744 ocfs2_wait_on_refreshing_lock(lockres);
1745 goto refresh_check;
1746 }
1747
1748 /* Ok, I'll be the one to refresh this lock. */
1749 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
1750 spin_unlock_irqrestore(&lockres->l_lock, flags);
1751
1752 status = 1;
1753bail:
1754 mlog_exit(status);
1755 return status;
1756}
1757
1758/* If status is non zero, I'll mark it as not being in refresh
1759 * anymroe, but i won't clear the needs refresh flag. */
1760static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
1761 int status)
1762{
1763 unsigned long flags;
1764 mlog_entry_void();
1765
1766 spin_lock_irqsave(&lockres->l_lock, flags);
1767 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
1768 if (!status)
1769 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
1770 spin_unlock_irqrestore(&lockres->l_lock, flags);
1771
1772 wake_up(&lockres->l_event);
1773
1774 mlog_exit_void();
1775}
1776
1777/* may or may not return a bh if it went to disk. */
e63aecb6 1778static int ocfs2_inode_lock_update(struct inode *inode,
ccd979bd
MF		 1779 struct buffer_head **bh)
1780{
1781 int status = 0;
1782 struct ocfs2_inode_info *oi = OCFS2_I(inode);
e63aecb6 1783 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
ccd979bd 1784 struct ocfs2_dinode *fe;
c271c5c2 1785 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ccd979bd
MF		 1786
1787 mlog_entry_void();
1788
be9e986b
MF		 1789 if (ocfs2_mount_local(osb))
1790 goto bail;
1791
ccd979bd
MF		 1792 spin_lock(&oi->ip_lock);
1793 if (oi->ip_flags & OCFS2_INODE_DELETED) {
b0697053 1794 mlog(0, "Orphaned inode %llu was deleted while we "
ccd979bd 1795 "were waiting on a lock. ip_flags = 0x%x\n",
b0697053 1796 (unsigned long long)oi->ip_blkno, oi->ip_flags);
ccd979bd
MF		 1797 spin_unlock(&oi->ip_lock);
1798 status = -ENOENT;
1799 goto bail;
1800 }
1801 spin_unlock(&oi->ip_lock);
1802
be9e986b
MF		 1803 if (!ocfs2_should_refresh_lock_res(lockres))
1804 goto bail;
ccd979bd
MF		 1805
1806 /* This will discard any caching information we might have had
1807 * for the inode metadata. */
1808 ocfs2_metadata_cache_purge(inode);
1809
83418978
MF		 1810 ocfs2_extent_map_trunc(inode, 0);
1811
be9e986b 1812 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
b0697053
MF		 1813 mlog(0, "Trusting LVB on inode %llu\n",
1814 (unsigned long long)oi->ip_blkno);
ccd979bd
MF		 1815 ocfs2_refresh_inode_from_lvb(inode);
1816 } else {
1817 /* Boo, we have to go to disk. */
1818 /* read bh, cast, ocfs2_refresh_inode */
1819 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno,
1820 bh, OCFS2_BH_CACHED, inode);
1821 if (status < 0) {
1822 mlog_errno(status);
1823 goto bail_refresh;
1824 }
1825 fe = (struct ocfs2_dinode *) (*bh)->b_data;
1826
1827 /* This is a good chance to make sure we're not
1828 * locking an invalid object.
1829 *
1830 * We bug on a stale inode here because we checked
1831 * above whether it was wiped from disk. The wiping
1832 * node provides a guarantee that we receive that
1833 * message and can mark the inode before dropping any
1834 * locks associated with it. */
1835 if (!OCFS2_IS_VALID_DINODE(fe)) {
1836 OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
1837 status = -EIO;
1838 goto bail_refresh;
1839 }
1840 mlog_bug_on_msg(inode->i_generation !=
1841 le32_to_cpu(fe->i_generation),
b0697053 1842 "Invalid dinode %llu disk generation: %u "
ccd979bd 1843 "inode->i_generation: %u\n",
b0697053
MF		 1844 (unsigned long long)oi->ip_blkno,
1845 le32_to_cpu(fe->i_generation),
ccd979bd
MF		 1846 inode->i_generation);
1847 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
1848 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
b0697053
MF		 1849 "Stale dinode %llu dtime: %llu flags: 0x%x\n",
1850 (unsigned long long)oi->ip_blkno,
1851 (unsigned long long)le64_to_cpu(fe->i_dtime),
ccd979bd
MF		 1852 le32_to_cpu(fe->i_flags));
1853
1854 ocfs2_refresh_inode(inode, fe);
1855 }
1856
1857 status = 0;
1858bail_refresh:
be9e986b 1859 ocfs2_complete_lock_res_refresh(lockres, status);
ccd979bd
MF		 1860bail:
1861 mlog_exit(status);
1862 return status;
1863}
1864
1865static int ocfs2_assign_bh(struct inode *inode,
1866 struct buffer_head **ret_bh,
1867 struct buffer_head *passed_bh)
1868{
1869 int status;
1870
1871 if (passed_bh) {
1872 /* Ok, the update went to disk for us, use the
1873 * returned bh. */
1874 *ret_bh = passed_bh;
1875 get_bh(*ret_bh);
1876
1877 return 0;
1878 }
1879
1880 status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
1881 OCFS2_I(inode)->ip_blkno,
1882 ret_bh,
1883 OCFS2_BH_CACHED,
1884 inode);
1885 if (status < 0)
1886 mlog_errno(status);
1887
1888 return status;
1889}
1890
1891/*
1892 * returns < 0 error if the callback will never be called, otherwise
1893 * the result of the lock will be communicated via the callback.
1894 */
e63aecb6 1895int ocfs2_inode_lock_full(struct inode *inode,
ccd979bd
MF		 1896 struct buffer_head **ret_bh,
1897 int ex,
1898 int arg_flags)
1899{
1900 int status, level, dlm_flags, acquired;
c271c5c2 1901 struct ocfs2_lock_res *lockres = NULL;
ccd979bd
MF		 1902 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1903 struct buffer_head *local_bh = NULL;
1904
1905 BUG_ON(!inode);
1906
1907 mlog_entry_void();
1908
b0697053
MF		 1909 mlog(0, "inode %llu, take %s META lock\n",
1910 (unsigned long long)OCFS2_I(inode)->ip_blkno,
ccd979bd
MF		 1911 ex ? "EXMODE" : "PRMODE");
1912
1913 status = 0;
1914 acquired = 0;
1915 /* We'll allow faking a readonly metadata lock for
1916 * rodevices. */
1917 if (ocfs2_is_hard_readonly(osb)) {
1918 if (ex)
1919 status = -EROFS;
1920 goto bail;
1921 }
1922
c271c5c2
SM		 1923 if (ocfs2_mount_local(osb))
1924 goto local;
1925
ccd979bd
MF		 1926 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
1927 wait_event(osb->recovery_event,
1928 ocfs2_node_map_is_empty(osb, &osb->recovery_map));
1929
e63aecb6 1930 lockres = &OCFS2_I(inode)->ip_inode_lockres;
ccd979bd
MF		 1931 level = ex ? LKM_EXMODE : LKM_PRMODE;
1932 dlm_flags = 0;
1933 if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
1934 dlm_flags |= LKM_NOQUEUE;
1935
1936 status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags);
1937 if (status < 0) {
1938 if (status != -EAGAIN && status != -EIOCBRETRY)
1939 mlog_errno(status);
1940 goto bail;
1941 }
1942
1943 /* Notify the error cleanup path to drop the cluster lock. */
1944 acquired = 1;
1945
1946 /* We wait twice because a node may have died while we were in
1947 * the lower dlm layers. The second time though, we've
1948 * committed to owning this lock so we don't allow signals to
1949 * abort the operation. */
1950 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
1951 wait_event(osb->recovery_event,
1952 ocfs2_node_map_is_empty(osb, &osb->recovery_map));
1953
c271c5c2 1954local:
24c19ef4
MF		 1955 /*
1956 * We only see this flag if we're being called from
1957 * ocfs2_read_locked_inode(). It means we're locking an inode
1958 * which hasn't been populated yet, so clear the refresh flag
1959 * and let the caller handle it.
1960 */
1961 if (inode->i_state & I_NEW) {
1962 status = 0;
c271c5c2
SM		 1963 if (lockres)
1964 ocfs2_complete_lock_res_refresh(lockres, 0);
24c19ef4
MF		 1965 goto bail;
1966 }
1967
ccd979bd 1968 /* This is fun. The caller may want a bh back, or it may
e63aecb6 1969 * not. ocfs2_inode_lock_update definitely wants one in, but
ccd979bd
MF		 1970 * may or may not read one, depending on what's in the
1971 * LVB. The result of all of this is that we've *only* gone to
1972 * disk if we have to, so the complexity is worthwhile. */
e63aecb6 1973 status = ocfs2_inode_lock_update(inode, &local_bh);
ccd979bd
MF		 1974 if (status < 0) {
1975 if (status != -ENOENT)
1976 mlog_errno(status);
1977 goto bail;
1978 }
1979
1980 if (ret_bh) {
1981 status = ocfs2_assign_bh(inode, ret_bh, local_bh);
1982 if (status < 0) {
1983 mlog_errno(status);
1984 goto bail;
1985 }
1986 }
1987
ccd979bd
MF		 1988bail:
1989 if (status < 0) {
1990 if (ret_bh && (*ret_bh)) {
1991 brelse(*ret_bh);
1992 *ret_bh = NULL;
1993 }
1994 if (acquired)
e63aecb6 1995 ocfs2_inode_unlock(inode, ex);
ccd979bd
MF		 1996 }
1997
1998 if (local_bh)
1999 brelse(local_bh);
2000
2001 mlog_exit(status);
2002 return status;
2003}
2004
2005/*
34d024f8
MF		 2006 * This is working around a lock inversion between tasks acquiring DLM
2007 * locks while holding a page lock and the downconvert thread which
2008 * blocks dlm lock acquiry while acquiring page locks.
ccd979bd
MF		 2009 *
2010 * ** These _with_page variantes are only intended to be called from aop
2011 * methods that hold page locks and return a very specific *positive* error
2012 * code that aop methods pass up to the VFS -- test for errors with != 0. **
2013 *
34d024f8
MF		 2014 * The DLM is called such that it returns -EAGAIN if it would have
2015 * blocked waiting for the downconvert thread. In that case we unlock
2016 * our page so the downconvert thread can make progress. Once we've
2017 * done this we have to return AOP_TRUNCATED_PAGE so the aop method
2018 * that called us can bubble that back up into the VFS who will then
2019 * immediately retry the aop call.
ccd979bd
MF		 2020 *
2021 * We do a blocking lock and immediate unlock before returning, though, so that
2022 * the lock has a great chance of being cached on this node by the time the VFS
2023 * calls back to retry the aop. This has a potential to livelock as nodes
2024 * ping locks back and forth, but that's a risk we're willing to take to avoid
2025 * the lock inversion simply.
2026 */
e63aecb6 2027int ocfs2_inode_lock_with_page(struct inode *inode,
ccd979bd
MF		 2028 struct buffer_head **ret_bh,
2029 int ex,
2030 struct page *page)
2031{
2032 int ret;
2033
e63aecb6 2034 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
ccd979bd
MF		 2035 if (ret == -EAGAIN) {
2036 unlock_page(page);
e63aecb6
MF		 2037 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
2038 ocfs2_inode_unlock(inode, ex);
ccd979bd
MF		 2039 ret = AOP_TRUNCATED_PAGE;
2040 }
2041
2042 return ret;
2043}
2044
e63aecb6 2045int ocfs2_inode_lock_atime(struct inode *inode,
7f1a37e3
TY		 2046 struct vfsmount *vfsmnt,
2047 int *level)
2048{
2049 int ret;
2050
2051 mlog_entry_void();
e63aecb6 2052 ret = ocfs2_inode_lock(inode, NULL, 0);
7f1a37e3
TY		 2053 if (ret < 0) {
2054 mlog_errno(ret);
2055 return ret;
2056 }
2057
2058 /*
2059 * If we should update atime, we will get EX lock,
2060 * otherwise we just get PR lock.
2061 */
2062 if (ocfs2_should_update_atime(inode, vfsmnt)) {
2063 struct buffer_head *bh = NULL;
2064
e63aecb6
MF		 2065 ocfs2_inode_unlock(inode, 0);
2066 ret = ocfs2_inode_lock(inode, &bh, 1);
7f1a37e3
TY		 2067 if (ret < 0) {
2068 mlog_errno(ret);
2069 return ret;
2070 }
2071 *level = 1;
2072 if (ocfs2_should_update_atime(inode, vfsmnt))
2073 ocfs2_update_inode_atime(inode, bh);
2074 if (bh)
2075 brelse(bh);
2076 } else
2077 *level = 0;
2078
2079 mlog_exit(ret);
2080 return ret;
2081}
2082
e63aecb6 2083void ocfs2_inode_unlock(struct inode *inode,
ccd979bd
MF		 2084 int ex)
2085{
2086 int level = ex ? LKM_EXMODE : LKM_PRMODE;
e63aecb6 2087 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
c271c5c2 2088 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ccd979bd
MF		 2089
2090 mlog_entry_void();
2091
b0697053
MF		 2092 mlog(0, "inode %llu drop %s META lock\n",
2093 (unsigned long long)OCFS2_I(inode)->ip_blkno,
ccd979bd
MF		 2094 ex ? "EXMODE" : "PRMODE");
2095
c271c5c2
SM		 2096 if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
2097 !ocfs2_mount_local(osb))
ccd979bd
MF		 2098 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
2099
2100 mlog_exit_void();
2101}
2102
2103int ocfs2_super_lock(struct ocfs2_super *osb,
2104 int ex)
2105{
c271c5c2 2106 int status = 0;
ccd979bd
MF		 2107 int level = ex ? LKM_EXMODE : LKM_PRMODE;
2108 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2109 struct buffer_head *bh;
2110 struct ocfs2_slot_info *si = osb->slot_info;
2111
2112 mlog_entry_void();
2113
2114 if (ocfs2_is_hard_readonly(osb))
2115 return -EROFS;
2116
c271c5c2
SM		 2117 if (ocfs2_mount_local(osb))
2118 goto bail;
2119
ccd979bd
MF		 2120 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
2121 if (status < 0) {
2122 mlog_errno(status);
2123 goto bail;
2124 }
2125
2126 /* The super block lock path is really in the best position to
2127 * know when resources covered by the lock need to be
2128 * refreshed, so we do it here. Of course, making sense of
2129 * everything is up to the caller :) */
2130 status = ocfs2_should_refresh_lock_res(lockres);
2131 if (status < 0) {
2132 mlog_errno(status);
2133 goto bail;
2134 }
2135 if (status) {
2136 bh = si->si_bh;
2137 status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0,
2138 si->si_inode);
2139 if (status == 0)
2140 ocfs2_update_slot_info(si);
2141
2142 ocfs2_complete_lock_res_refresh(lockres, status);
2143
2144 if (status < 0)
2145 mlog_errno(status);
2146 }
2147bail:
2148 mlog_exit(status);
2149 return status;
2150}
2151
2152void ocfs2_super_unlock(struct ocfs2_super *osb,
2153 int ex)
2154{
2155 int level = ex ? LKM_EXMODE : LKM_PRMODE;
2156 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
2157
c271c5c2
SM		 2158 if (!ocfs2_mount_local(osb))
2159 ocfs2_cluster_unlock(osb, lockres, level);
ccd979bd
MF		 2160}
2161
2162int ocfs2_rename_lock(struct ocfs2_super *osb)
2163{
2164 int status;
2165 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2166
2167 if (ocfs2_is_hard_readonly(osb))
2168 return -EROFS;
2169
c271c5c2
SM		 2170 if (ocfs2_mount_local(osb))
2171 return 0;
2172
ccd979bd
MF		 2173 status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0);
2174 if (status < 0)
2175 mlog_errno(status);
2176
2177 return status;
2178}
2179
2180void ocfs2_rename_unlock(struct ocfs2_super *osb)
2181{
2182 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2183
c271c5c2
SM		 2184 if (!ocfs2_mount_local(osb))
2185 ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE);
ccd979bd
MF		 2186}
2187
d680efe9
MF		 2188int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2189{
2190 int ret;
2191 int level = ex ? LKM_EXMODE : LKM_PRMODE;
2192 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2193 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2194
2195 BUG_ON(!dl);
2196
2197 if (ocfs2_is_hard_readonly(osb))
2198 return -EROFS;
2199
c271c5c2
SM		 2200 if (ocfs2_mount_local(osb))
2201 return 0;
2202
d680efe9
MF		 2203 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2204 if (ret < 0)
2205 mlog_errno(ret);
2206
2207 return ret;
2208}
2209
2210void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2211{
2212 int level = ex ? LKM_EXMODE : LKM_PRMODE;
2213 struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2214 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2215
c271c5c2
SM		 2216 if (!ocfs2_mount_local(osb))
2217 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
d680efe9
MF		 2218}
2219
ccd979bd
MF		 2220/* Reference counting of the dlm debug structure. We want this because
2221 * open references on the debug inodes can live on after a mount, so
2222 * we can't rely on the ocfs2_super to always exist. */
2223static void ocfs2_dlm_debug_free(struct kref *kref)
2224{
2225 struct ocfs2_dlm_debug *dlm_debug;
2226
2227 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
2228
2229 kfree(dlm_debug);
2230}
2231
2232void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
2233{
2234 if (dlm_debug)
2235 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
2236}
2237
2238static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
2239{
2240 kref_get(&debug->d_refcnt);
2241}
2242
2243struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
2244{
2245 struct ocfs2_dlm_debug *dlm_debug;
2246
2247 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
2248 if (!dlm_debug) {
2249 mlog_errno(-ENOMEM);
2250 goto out;
2251 }
2252
2253 kref_init(&dlm_debug->d_refcnt);
2254 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
2255 dlm_debug->d_locking_state = NULL;
2256out:
2257 return dlm_debug;
2258}
2259
2260/* Access to this is arbitrated for us via seq_file->sem. */
2261struct ocfs2_dlm_seq_priv {
2262 struct ocfs2_dlm_debug *p_dlm_debug;
2263 struct ocfs2_lock_res p_iter_res;
2264 struct ocfs2_lock_res p_tmp_res;
2265};
2266
2267static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
2268 struct ocfs2_dlm_seq_priv *priv)
2269{
2270 struct ocfs2_lock_res *iter, *ret = NULL;
2271 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
2272
2273 assert_spin_locked(&ocfs2_dlm_tracking_lock);
2274
2275 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
2276 /* discover the head of the list */
2277 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
2278 mlog(0, "End of list found, %p\n", ret);
2279 break;
2280 }
2281
2282 /* We track our "dummy" iteration lockres' by a NULL
2283 * l_ops field. */
2284 if (iter->l_ops != NULL) {
2285 ret = iter;
2286 break;
2287 }
2288 }
2289
2290 return ret;
2291}
2292
2293static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
2294{
2295 struct ocfs2_dlm_seq_priv *priv = m->private;
2296 struct ocfs2_lock_res *iter;
2297
2298 spin_lock(&ocfs2_dlm_tracking_lock);
2299 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
2300 if (iter) {
2301 /* Since lockres' have the lifetime of their container
2302 * (which can be inodes, ocfs2_supers, etc) we want to
2303 * copy this out to a temporary lockres while still
2304 * under the spinlock. Obviously after this we can't
2305 * trust any pointers on the copy returned, but that's
2306 * ok as the information we want isn't typically held
2307 * in them. */
2308 priv->p_tmp_res = *iter;
2309 iter = &priv->p_tmp_res;
2310 }
2311 spin_unlock(&ocfs2_dlm_tracking_lock);
2312
2313 return iter;
2314}
2315
2316static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
2317{
2318}
2319
2320static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
2321{
2322 struct ocfs2_dlm_seq_priv *priv = m->private;
2323 struct ocfs2_lock_res *iter = v;
2324 struct ocfs2_lock_res *dummy = &priv->p_iter_res;
2325
2326 spin_lock(&ocfs2_dlm_tracking_lock);
2327 iter = ocfs2_dlm_next_res(iter, priv);
2328 list_del_init(&dummy->l_debug_list);
2329 if (iter) {
2330 list_add(&dummy->l_debug_list, &iter->l_debug_list);
2331 priv->p_tmp_res = *iter;
2332 iter = &priv->p_tmp_res;
2333 }
2334 spin_unlock(&ocfs2_dlm_tracking_lock);
2335
2336 return iter;
2337}
2338
2339/* So that debugfs.ocfs2 can determine which format is being used */
2340#define OCFS2_DLM_DEBUG_STR_VERSION 1
2341static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
2342{
2343 int i;
2344 char *lvb;
2345 struct ocfs2_lock_res *lockres = v;
2346
2347 if (!lockres)
2348 return -EINVAL;
2349
d680efe9
MF		 2350 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
2351
2352 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
2353 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
2354 lockres->l_name,
2355 (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
2356 else
2357 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
2358
2359 seq_printf(m, "%d\t"
ccd979bd
MF		 2360 "0x%lx\t"
2361 "0x%x\t"
2362 "0x%x\t"
2363 "%u\t"
2364 "%u\t"
2365 "%d\t"
2366 "%d\t",
ccd979bd
MF		 2367 lockres->l_level,
2368 lockres->l_flags,
2369 lockres->l_action,
2370 lockres->l_unlock_action,
2371 lockres->l_ro_holders,
2372 lockres->l_ex_holders,
2373 lockres->l_requested,
2374 lockres->l_blocking);
2375
2376 /* Dump the raw LVB */
2377 lvb = lockres->l_lksb.lvb;
2378 for(i = 0; i < DLM_LVB_LEN; i++)
2379 seq_printf(m, "0x%x\t", lvb[i]);
2380
2381 /* End the line */
2382 seq_printf(m, "\n");
2383 return 0;
2384}
2385
2386static struct seq_operations ocfs2_dlm_seq_ops = {
2387 .start = ocfs2_dlm_seq_start,
2388 .stop = ocfs2_dlm_seq_stop,
2389 .next = ocfs2_dlm_seq_next,
2390 .show = ocfs2_dlm_seq_show,
2391};
2392
2393static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
2394{
2395 struct seq_file *seq = (struct seq_file *) file->private_data;
2396 struct ocfs2_dlm_seq_priv *priv = seq->private;
2397 struct ocfs2_lock_res *res = &priv->p_iter_res;
2398
2399 ocfs2_remove_lockres_tracking(res);
2400 ocfs2_put_dlm_debug(priv->p_dlm_debug);
2401 return seq_release_private(inode, file);
2402}
2403
2404static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
2405{
2406 int ret;
2407 struct ocfs2_dlm_seq_priv *priv;
2408 struct seq_file *seq;
2409 struct ocfs2_super *osb;
2410
2411 priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL);
2412 if (!priv) {
2413 ret = -ENOMEM;
2414 mlog_errno(ret);
2415 goto out;
2416 }
8e18e294 2417 osb = inode->i_private;
ccd979bd
MF		 2418 ocfs2_get_dlm_debug(osb->osb_dlm_debug);
2419 priv->p_dlm_debug = osb->osb_dlm_debug;
2420 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
2421
2422 ret = seq_open(file, &ocfs2_dlm_seq_ops);
2423 if (ret) {
2424 kfree(priv);
2425 mlog_errno(ret);
2426 goto out;
2427 }
2428
2429 seq = (struct seq_file *) file->private_data;
2430 seq->private = priv;
2431
2432 ocfs2_add_lockres_tracking(&priv->p_iter_res,
2433 priv->p_dlm_debug);
2434
2435out:
2436 return ret;
2437}
2438
4b6f5d20 2439static const struct file_operations ocfs2_dlm_debug_fops = {
ccd979bd
MF		 2440 .open = ocfs2_dlm_debug_open,
2441 .release = ocfs2_dlm_debug_release,
2442 .read = seq_read,
2443 .llseek = seq_lseek,
2444};
2445
2446static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
2447{
2448 int ret = 0;
2449 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
2450
2451 dlm_debug->d_locking_state = debugfs_create_file("locking_state",
2452 S_IFREG|S_IRUSR,
2453 osb->osb_debug_root,
2454 osb,
2455 &ocfs2_dlm_debug_fops);
2456 if (!dlm_debug->d_locking_state) {
2457 ret = -EINVAL;
2458 mlog(ML_ERROR,
2459 "Unable to create locking state debugfs file.\n");
2460 goto out;
2461 }
2462
2463 ocfs2_get_dlm_debug(dlm_debug);
2464out:
2465 return ret;
2466}
2467
2468static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
2469{
2470 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
2471
2472 if (dlm_debug) {
2473 debugfs_remove(dlm_debug->d_locking_state);
2474 ocfs2_put_dlm_debug(dlm_debug);
2475 }
2476}
2477
2478int ocfs2_dlm_init(struct ocfs2_super *osb)
2479{
c271c5c2 2480 int status = 0;
ccd979bd 2481 u32 dlm_key;
c271c5c2 2482 struct dlm_ctxt *dlm = NULL;
ccd979bd
MF		 2483
2484 mlog_entry_void();
2485
c271c5c2
SM		 2486 if (ocfs2_mount_local(osb))
2487 goto local;
2488
ccd979bd
MF		 2489 status = ocfs2_dlm_init_debug(osb);
2490 if (status < 0) {
2491 mlog_errno(status);
2492 goto bail;
2493 }
2494
34d024f8
MF		 2495 /* launch downconvert thread */
2496 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc");
2497 if (IS_ERR(osb->dc_task)) {
2498 status = PTR_ERR(osb->dc_task);
2499 osb->dc_task = NULL;
ccd979bd
MF		 2500 mlog_errno(status);
2501 goto bail;
2502 }
2503
2504 /* used by the dlm code to make message headers unique, each
2505 * node in this domain must agree on this. */
2506 dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str));
2507
2508 /* for now, uuid == domain */
2509 dlm = dlm_register_domain(osb->uuid_str, dlm_key);
2510 if (IS_ERR(dlm)) {
2511 status = PTR_ERR(dlm);
2512 mlog_errno(status);
2513 goto bail;
2514 }
2515
c271c5c2
SM		 2516 dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb);
2517
2518local:
ccd979bd
MF		 2519 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
2520 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
2521
ccd979bd
MF		 2522 osb->dlm = dlm;
2523
2524 status = 0;
2525bail:
2526 if (status < 0) {
2527 ocfs2_dlm_shutdown_debug(osb);
34d024f8
MF		 2528 if (osb->dc_task)
2529 kthread_stop(osb->dc_task);
ccd979bd
MF		 2530 }
2531
2532 mlog_exit(status);
2533 return status;
2534}
2535
2536void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
2537{
2538 mlog_entry_void();
2539
2540 dlm_unregister_eviction_cb(&osb->osb_eviction_cb);
2541
2542 ocfs2_drop_osb_locks(osb);
2543
34d024f8
MF		 2544 if (osb->dc_task) {
2545 kthread_stop(osb->dc_task);
2546 osb->dc_task = NULL;
ccd979bd
MF		 2547 }
2548
2549 ocfs2_lock_res_free(&osb->osb_super_lockres);
2550 ocfs2_lock_res_free(&osb->osb_rename_lockres);
2551
2552 dlm_unregister_domain(osb->dlm);
2553 osb->dlm = NULL;
2554
2555 ocfs2_dlm_shutdown_debug(osb);
2556
2557 mlog_exit_void();
2558}
2559
2a45f2d1 2560static void ocfs2_unlock_ast(void *opaque, enum dlm_status status)
ccd979bd
MF		 2561{
2562 struct ocfs2_lock_res *lockres = opaque;
2563 unsigned long flags;
2564
2565 mlog_entry_void();
2566
2567 mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
2568 lockres->l_unlock_action);
2569
2570 spin_lock_irqsave(&lockres->l_lock, flags);
2571 /* We tried to cancel a convert request, but it was already
2572 * granted. All we want to do here is clear our unlock
2573 * state. The wake_up call done at the bottom is redundant
2574 * (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't
2575 * hurt anything anyway */
2576 if (status == DLM_CANCELGRANT &&
2577 lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
2578 mlog(0, "Got cancelgrant for %s\n", lockres->l_name);
2579
2580 /* We don't clear the busy flag in this case as it
2581 * should have been cleared by the ast which the dlm
2582 * has called. */
2583 goto complete_unlock;
2584 }
2585
2586 if (status != DLM_NORMAL) {
2587 mlog(ML_ERROR, "Dlm passes status %d for lock %s, "
2588 "unlock_action %d\n", status, lockres->l_name,
2589 lockres->l_unlock_action);
2590 spin_unlock_irqrestore(&lockres->l_lock, flags);
2591 return;
2592 }
2593
2594 switch(lockres->l_unlock_action) {
2595 case OCFS2_UNLOCK_CANCEL_CONVERT:
2596 mlog(0, "Cancel convert success for %s\n", lockres->l_name);
2597 lockres->l_action = OCFS2_AST_INVALID;
2598 break;
2599 case OCFS2_UNLOCK_DROP_LOCK:
2600 lockres->l_level = LKM_IVMODE;
2601 break;
2602 default:
2603 BUG();
2604 }
2605
2606 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
2607complete_unlock:
2608 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
2609 spin_unlock_irqrestore(&lockres->l_lock, flags);
2610
2611 wake_up(&lockres->l_event);
2612
2613 mlog_exit_void();
2614}
2615
ccd979bd 2616static int ocfs2_drop_lock(struct ocfs2_super *osb,
0d5dc6c2 2617 struct ocfs2_lock_res *lockres)
ccd979bd
MF		 2618{
2619 enum dlm_status status;
2620 unsigned long flags;
b80fc012 2621 int lkm_flags = 0;
ccd979bd
MF		 2622
2623 /* We didn't get anywhere near actually using this lockres. */
2624 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
2625 goto out;
2626
b80fc012
MF		 2627 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
2628 lkm_flags |= LKM_VALBLK;
2629
ccd979bd
MF		 2630 spin_lock_irqsave(&lockres->l_lock, flags);
2631
2632 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
2633 "lockres %s, flags 0x%lx\n",
2634 lockres->l_name, lockres->l_flags);
2635
2636 while (lockres->l_flags & OCFS2_LOCK_BUSY) {
2637 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
2638 "%u, unlock_action = %u\n",
2639 lockres->l_name, lockres->l_flags, lockres->l_action,
2640 lockres->l_unlock_action);
2641
2642 spin_unlock_irqrestore(&lockres->l_lock, flags);
2643
2644 /* XXX: Today we just wait on any busy
2645 * locks... Perhaps we need to cancel converts in the
2646 * future? */
2647 ocfs2_wait_on_busy_lock(lockres);
2648
2649 spin_lock_irqsave(&lockres->l_lock, flags);
2650 }
2651
0d5dc6c2
MF		 2652 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
2653 if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
2654 lockres->l_level == LKM_EXMODE &&
2655 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
2656 lockres->l_ops->set_lvb(lockres);
2657 }
ccd979bd
MF		 2658
2659 if (lockres->l_flags & OCFS2_LOCK_BUSY)
2660 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
2661 lockres->l_name);
2662 if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
2663 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
2664
2665 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
2666 spin_unlock_irqrestore(&lockres->l_lock, flags);
2667 goto out;
2668 }
2669
2670 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
2671
2672 /* make sure we never get here while waiting for an ast to
2673 * fire. */
2674 BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
2675
2676 /* is this necessary? */
2677 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2678 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
2679 spin_unlock_irqrestore(&lockres->l_lock, flags);
2680
2681 mlog(0, "lock %s\n", lockres->l_name);
2682
b80fc012 2683 status = dlmunlock(osb->dlm, &lockres->l_lksb, lkm_flags,
2a45f2d1 2684 ocfs2_unlock_ast, lockres);
ccd979bd
MF		 2685 if (status != DLM_NORMAL) {
2686 ocfs2_log_dlm_error("dlmunlock", status, lockres);
2687 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
2688 dlm_print_one_lock(lockres->l_lksb.lockid);
2689 BUG();
2690 }
2691 mlog(0, "lock %s, successfull return from dlmunlock\n",
2692 lockres->l_name);
2693
2694 ocfs2_wait_on_busy_lock(lockres);
2695out:
2696 mlog_exit(0);
2697 return 0;
2698}
2699
2700/* Mark the lockres as being dropped. It will no longer be
2701 * queued if blocking, but we still may have to wait on it
34d024f8 2702 * being dequeued from the downconvert thread before we can consider
ccd979bd
MF		 2703 * it safe to drop.
2704 *
2705 * You can *not* attempt to call cluster_lock on this lockres anymore. */
2706void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres)
2707{
2708 int status;
2709 struct ocfs2_mask_waiter mw;
2710 unsigned long flags;
2711
2712 ocfs2_init_mask_waiter(&mw);
2713
2714 spin_lock_irqsave(&lockres->l_lock, flags);
2715 lockres->l_flags |= OCFS2_LOCK_FREEING;
2716 while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
2717 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
2718 spin_unlock_irqrestore(&lockres->l_lock, flags);
2719
2720 mlog(0, "Waiting on lockres %s\n", lockres->l_name);
2721
2722 status = ocfs2_wait_for_mask(&mw);
2723 if (status)
2724 mlog_errno(status);
2725
2726 spin_lock_irqsave(&lockres->l_lock, flags);
2727 }
2728 spin_unlock_irqrestore(&lockres->l_lock, flags);
2729}
2730
d680efe9
MF		 2731void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
2732 struct ocfs2_lock_res *lockres)
ccd979bd 2733{
d680efe9 2734 int ret;
ccd979bd 2735
d680efe9 2736 ocfs2_mark_lockres_freeing(lockres);
0d5dc6c2 2737 ret = ocfs2_drop_lock(osb, lockres);
d680efe9
MF		 2738 if (ret)
2739 mlog_errno(ret);
2740}
ccd979bd 2741
d680efe9
MF		 2742static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
2743{
2744 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
2745 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
ccd979bd
MF		 2746}
2747
ccd979bd
MF		 2748int ocfs2_drop_inode_locks(struct inode *inode)
2749{
2750 int status, err;
ccd979bd
MF		 2751
2752 mlog_entry_void();
2753
2754 /* No need to call ocfs2_mark_lockres_freeing here -
2755 * ocfs2_clear_inode has done it for us. */
2756
2757 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
50008630 2758 &OCFS2_I(inode)->ip_open_lockres);
ccd979bd
MF		 2759 if (err < 0)
2760 mlog_errno(err);
2761
2762 status = err;
2763
2764 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
e63aecb6 2765 &OCFS2_I(inode)->ip_inode_lockres);
ccd979bd
MF		 2766 if (err < 0)
2767 mlog_errno(err);
2768 if (err < 0 && !status)
2769 status = err;
2770
2771 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
0d5dc6c2 2772 &OCFS2_I(inode)->ip_rw_lockres);
ccd979bd
MF		 2773 if (err < 0)
2774 mlog_errno(err);
2775 if (err < 0 && !status)
2776 status = err;
2777
2778 mlog_exit(status);
2779 return status;
2780}
2781
2782static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
2783 int new_level)
2784{
2785 assert_spin_locked(&lockres->l_lock);
2786
2787 BUG_ON(lockres->l_blocking <= LKM_NLMODE);
2788
2789 if (lockres->l_level <= new_level) {
2790 mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n",
2791 lockres->l_level, new_level);
2792 BUG();
2793 }
2794
2795 mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
2796 lockres->l_name, new_level, lockres->l_blocking);
2797
2798 lockres->l_action = OCFS2_AST_DOWNCONVERT;
2799 lockres->l_requested = new_level;
2800 lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2801}
2802
2803static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
2804 struct ocfs2_lock_res *lockres,
2805 int new_level,
2806 int lvb)
2807{
2808 int ret, dlm_flags = LKM_CONVERT;
2809 enum dlm_status status;
2810
2811 mlog_entry_void();
2812
2813 if (lvb)
2814 dlm_flags |= LKM_VALBLK;
2815
2816 status = dlmlock(osb->dlm,
2817 new_level,
2818 &lockres->l_lksb,
2819 dlm_flags,
2820 lockres->l_name,
f0681062 2821 OCFS2_LOCK_ID_MAX_LEN - 1,
e92d57df 2822 ocfs2_locking_ast,
ccd979bd 2823 lockres,
aa2623ad 2824 ocfs2_blocking_ast);
ccd979bd
MF		 2825 if (status != DLM_NORMAL) {
2826 ocfs2_log_dlm_error("dlmlock", status, lockres);
2827 ret = -EINVAL;
2828 ocfs2_recover_from_dlm_error(lockres, 1);
2829 goto bail;
2830 }
2831
2832 ret = 0;
2833bail:
2834 mlog_exit(ret);
2835 return ret;
2836}
2837
2838/* returns 1 when the caller should unlock and call dlmunlock */
2839static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
2840 struct ocfs2_lock_res *lockres)
2841{
2842 assert_spin_locked(&lockres->l_lock);
2843
2844 mlog_entry_void();
2845 mlog(0, "lock %s\n", lockres->l_name);
2846
2847 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
2848 /* If we're already trying to cancel a lock conversion
2849 * then just drop the spinlock and allow the caller to
2850 * requeue this lock. */
2851
2852 mlog(0, "Lockres %s, skip convert\n", lockres->l_name);
2853 return 0;
2854 }
2855
2856 /* were we in a convert when we got the bast fire? */
2857 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
2858 lockres->l_action != OCFS2_AST_DOWNCONVERT);
2859 /* set things up for the unlockast to know to just
2860 * clear out the ast_action and unset busy, etc. */
2861 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
2862
2863 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
2864 "lock %s, invalid flags: 0x%lx\n",
2865 lockres->l_name, lockres->l_flags);
2866
2867 return 1;
2868}
2869
2870static int ocfs2_cancel_convert(struct ocfs2_super *osb,
2871 struct ocfs2_lock_res *lockres)
2872{
2873 int ret;
2874 enum dlm_status status;
2875
2876 mlog_entry_void();
2877 mlog(0, "lock %s\n", lockres->l_name);
2878
2879 ret = 0;
2880 status = dlmunlock(osb->dlm,
2881 &lockres->l_lksb,
2882 LKM_CANCEL,
2a45f2d1 2883 ocfs2_unlock_ast,
ccd979bd
MF		 2884 lockres);
2885 if (status != DLM_NORMAL) {
2886 ocfs2_log_dlm_error("dlmunlock", status, lockres);
2887 ret = -EINVAL;
2888 ocfs2_recover_from_dlm_error(lockres, 0);
2889 }
2890
2891 mlog(0, "lock %s return from dlmunlock\n", lockres->l_name);
2892
ccd979bd
MF		 2893 mlog_exit(ret);
2894 return ret;
2895}
2896
b5e500e2
MF		 2897static int ocfs2_unblock_lock(struct ocfs2_super *osb,
2898 struct ocfs2_lock_res *lockres,
2899 struct ocfs2_unblock_ctl *ctl)
ccd979bd
MF		 2900{
2901 unsigned long flags;
2902 int blocking;
2903 int new_level;
2904 int ret = 0;
5ef0d4ea 2905 int set_lvb = 0;
ccd979bd
MF		 2906
2907 mlog_entry_void();
2908
2909 spin_lock_irqsave(&lockres->l_lock, flags);
2910
2911 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
2912
2913recheck:
2914 if (lockres->l_flags & OCFS2_LOCK_BUSY) {
d680efe9 2915 ctl->requeue = 1;
ccd979bd
MF		 2916 ret = ocfs2_prepare_cancel_convert(osb, lockres);
2917 spin_unlock_irqrestore(&lockres->l_lock, flags);
2918 if (ret) {
2919 ret = ocfs2_cancel_convert(osb, lockres);
2920 if (ret < 0)
2921 mlog_errno(ret);
2922 }
2923 goto leave;
2924 }
2925
2926 /* if we're blocking an exclusive and we have *any* holders,
2927 * then requeue. */
2928 if ((lockres->l_blocking == LKM_EXMODE)
f7fbfdd1
MF		 2929 && (lockres->l_ex_holders || lockres->l_ro_holders))
2930 goto leave_requeue;
ccd979bd
MF		 2931
2932 /* If it's a PR we're blocking, then only
2933 * requeue if we've got any EX holders */
2934 if (lockres->l_blocking == LKM_PRMODE &&
f7fbfdd1
MF		 2935 lockres->l_ex_holders)
2936 goto leave_requeue;
2937
2938 /*
2939 * Can we get a lock in this state if the holder counts are
2940 * zero? The meta data unblock code used to check this.
2941 */
2942 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
2943 && (lockres->l_flags & OCFS2_LOCK_REFRESHING))
2944 goto leave_requeue;
ccd979bd 2945
16d5b956
MF		 2946 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
2947
2948 if (lockres->l_ops->check_downconvert
2949 && !lockres->l_ops->check_downconvert(lockres, new_level))
2950 goto leave_requeue;
2951
ccd979bd
MF		 2952 /* If we get here, then we know that there are no more
2953 * incompatible holders (and anyone asking for an incompatible
2954 * lock is blocked). We can now downconvert the lock */
cc567d89 2955 if (!lockres->l_ops->downconvert_worker)
ccd979bd
MF		 2956 goto downconvert;
2957
2958 /* Some lockres types want to do a bit of work before
2959 * downconverting a lock. Allow that here. The worker function
2960 * may sleep, so we save off a copy of what we're blocking as
2961 * it may change while we're not holding the spin lock. */
2962 blocking = lockres->l_blocking;
2963 spin_unlock_irqrestore(&lockres->l_lock, flags);
2964
cc567d89 2965 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
d680efe9
MF		 2966
2967 if (ctl->unblock_action == UNBLOCK_STOP_POST)
2968 goto leave;
ccd979bd
MF		 2969
2970 spin_lock_irqsave(&lockres->l_lock, flags);
2971 if (blocking != lockres->l_blocking) {
2972 /* If this changed underneath us, then we can't drop
2973 * it just yet. */
2974 goto recheck;
2975 }
2976
2977downconvert:
d680efe9 2978 ctl->requeue = 0;
ccd979bd 2979
5ef0d4ea
MF		 2980 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
2981 if (lockres->l_level == LKM_EXMODE)
2982 set_lvb = 1;
2983
2984 /*
2985 * We only set the lvb if the lock has been fully
2986 * refreshed - otherwise we risk setting stale
2987 * data. Otherwise, there's no need to actually clear
2988 * out the lvb here as it's value is still valid.
2989 */
2990 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
2991 lockres->l_ops->set_lvb(lockres);
2992 }
2993
ccd979bd
MF		 2994 ocfs2_prepare_downconvert(lockres, new_level);
2995 spin_unlock_irqrestore(&lockres->l_lock, flags);
5ef0d4ea 2996 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
ccd979bd
MF		 2997leave:
2998 mlog_exit(ret);
2999 return ret;
f7fbfdd1
MF		 3000
3001leave_requeue:
3002 spin_unlock_irqrestore(&lockres->l_lock, flags);
3003 ctl->requeue = 1;
3004
3005 mlog_exit(0);
3006 return 0;
ccd979bd
MF		 3007}
3008
d680efe9
MF		 3009static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
3010 int blocking)
ccd979bd
MF		 3011{
3012 struct inode *inode;
3013 struct address_space *mapping;
3014
ccd979bd
MF		 3015 inode = ocfs2_lock_res_inode(lockres);
3016 mapping = inode->i_mapping;
3017
f1f54068
MF		 3018 if (S_ISREG(inode->i_mode))
3019 goto out;
3020
7f4a2a97
MF		 3021 /*
3022 * We need this before the filemap_fdatawrite() so that it can
3023 * transfer the dirty bit from the PTE to the
3024 * page. Unfortunately this means that even for EX->PR
3025 * downconverts, we'll lose our mappings and have to build
3026 * them up again.
3027 */
3028 unmap_mapping_range(mapping, 0, 0, 0);
3029
ccd979bd 3030 if (filemap_fdatawrite(mapping)) {
b0697053
MF		 3031 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
3032 (unsigned long long)OCFS2_I(inode)->ip_blkno);
ccd979bd
MF		 3033 }
3034 sync_mapping_buffers(mapping);
3035 if (blocking == LKM_EXMODE) {
3036 truncate_inode_pages(mapping, 0);
ccd979bd
MF		 3037 } else {
3038 /* We only need to wait on the I/O if we're not also
3039 * truncating pages because truncate_inode_pages waits
3040 * for us above. We don't truncate pages if we're
3041 * blocking anything < EXMODE because we want to keep
3042 * them around in that case. */
3043 filemap_fdatawait(mapping);
3044 }
3045
f1f54068 3046out:
d680efe9 3047 return UNBLOCK_CONTINUE;
ccd979bd
MF		 3048}
3049
810d5aeb
MF		 3050static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
3051 int new_level)
3052{
3053 struct inode *inode = ocfs2_lock_res_inode(lockres);
3054 int checkpointed = ocfs2_inode_fully_checkpointed(inode);
3055
3056 BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
3057 BUG_ON(lockres->l_level != LKM_EXMODE && !checkpointed);
3058
3059 if (checkpointed)
3060 return 1;
3061
3062 ocfs2_start_checkpoint(OCFS2_SB(inode->i_sb));
3063 return 0;
3064}
3065
3066static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
3067{
3068 struct inode *inode = ocfs2_lock_res_inode(lockres);
3069
3070 __ocfs2_stuff_meta_lvb(inode);
3071}
3072
d680efe9
MF		 3073/*
3074 * Does the final reference drop on our dentry lock. Right now this
34d024f8 3075 * happens in the downconvert thread, but we could choose to simplify the
d680efe9
MF		 3076 * dlmglue API and push these off to the ocfs2_wq in the future.
3077 */
3078static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
3079 struct ocfs2_lock_res *lockres)
3080{
3081 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
3082 ocfs2_dentry_lock_put(osb, dl);
3083}
3084
3085/*
3086 * d_delete() matching dentries before the lock downconvert.
3087 *
3088 * At this point, any process waiting to destroy the
3089 * dentry_lock due to last ref count is stopped by the
3090 * OCFS2_LOCK_QUEUED flag.
3091 *
3092 * We have two potential problems
3093 *
3094 * 1) If we do the last reference drop on our dentry_lock (via dput)
3095 * we'll wind up in ocfs2_release_dentry_lock(), waiting on
3096 * the downconvert to finish. Instead we take an elevated
3097 * reference and push the drop until after we've completed our
3098 * unblock processing.
3099 *
3100 * 2) There might be another process with a final reference,
3101 * waiting on us to finish processing. If this is the case, we
3102 * detect it and exit out - there's no more dentries anyway.
3103 */
3104static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
3105 int blocking)
3106{
3107 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
3108 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
3109 struct dentry *dentry;
3110 unsigned long flags;
3111 int extra_ref = 0;
3112
3113 /*
3114 * This node is blocking another node from getting a read
3115 * lock. This happens when we've renamed within a
3116 * directory. We've forced the other nodes to d_delete(), but
3117 * we never actually dropped our lock because it's still
3118 * valid. The downconvert code will retain a PR for this node,
3119 * so there's no further work to do.
3120 */
3121 if (blocking == LKM_PRMODE)
3122 return UNBLOCK_CONTINUE;
3123
3124 /*
3125 * Mark this inode as potentially orphaned. The code in
3126 * ocfs2_delete_inode() will figure out whether it actually
3127 * needs to be freed or not.
3128 */
3129 spin_lock(&oi->ip_lock);
3130 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
3131 spin_unlock(&oi->ip_lock);
3132
3133 /*
3134 * Yuck. We need to make sure however that the check of
3135 * OCFS2_LOCK_FREEING and the extra reference are atomic with
3136 * respect to a reference decrement or the setting of that
3137 * flag.
3138 */
3139 spin_lock_irqsave(&lockres->l_lock, flags);
3140 spin_lock(&dentry_attach_lock);
3141 if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
3142 && dl->dl_count) {
3143 dl->dl_count++;
3144 extra_ref = 1;
3145 }
3146 spin_unlock(&dentry_attach_lock);
3147 spin_unlock_irqrestore(&lockres->l_lock, flags);
3148
3149 mlog(0, "extra_ref = %d\n", extra_ref);
3150
3151 /*
3152 * We have a process waiting on us in ocfs2_dentry_iput(),
3153 * which means we can't have any more outstanding
3154 * aliases. There's no need to do any more work.
3155 */
3156 if (!extra_ref)
3157 return UNBLOCK_CONTINUE;
3158
3159 spin_lock(&dentry_attach_lock);
3160 while (1) {
3161 dentry = ocfs2_find_local_alias(dl->dl_inode,
3162 dl->dl_parent_blkno, 1);
3163 if (!dentry)
3164 break;
3165 spin_unlock(&dentry_attach_lock);
3166
3167 mlog(0, "d_delete(%.*s);\n", dentry->d_name.len,
3168 dentry->d_name.name);
3169
3170 /*
3171 * The following dcache calls may do an
3172 * iput(). Normally we don't want that from the
3173 * downconverting thread, but in this case it's ok
3174 * because the requesting node already has an
3175 * exclusive lock on the inode, so it can't be queued
3176 * for a downconvert.
3177 */
3178 d_delete(dentry);
3179 dput(dentry);
3180
3181 spin_lock(&dentry_attach_lock);
3182 }
3183 spin_unlock(&dentry_attach_lock);
3184
3185 /*
3186 * If we are the last holder of this dentry lock, there is no
3187 * reason to downconvert so skip straight to the unlock.
3188 */
3189 if (dl->dl_count == 1)
3190 return UNBLOCK_STOP_POST;
3191
3192 return UNBLOCK_CONTINUE_POST;
3193}
3194
ccd979bd
MF		 3195void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3196 struct ocfs2_lock_res *lockres)
3197{
3198 int status;
d680efe9 3199 struct ocfs2_unblock_ctl ctl = {0, 0,};
ccd979bd
MF		 3200 unsigned long flags;
3201
3202 /* Our reference to the lockres in this function can be
3203 * considered valid until we remove the OCFS2_LOCK_QUEUED
3204 * flag. */
3205
3206 mlog_entry_void();
3207
3208 BUG_ON(!lockres);
3209 BUG_ON(!lockres->l_ops);
ccd979bd
MF		 3210
3211 mlog(0, "lockres %s blocked.\n", lockres->l_name);
3212
3213 /* Detect whether a lock has been marked as going away while
34d024f8 3214 * the downconvert thread was processing other things. A lock can
ccd979bd
MF		 3215 * still be marked with OCFS2_LOCK_FREEING after this check,
3216 * but short circuiting here will still save us some
3217 * performance. */
3218 spin_lock_irqsave(&lockres->l_lock, flags);
3219 if (lockres->l_flags & OCFS2_LOCK_FREEING)
3220 goto unqueue;
3221 spin_unlock_irqrestore(&lockres->l_lock, flags);
3222
b5e500e2 3223 status = ocfs2_unblock_lock(osb, lockres, &ctl);
ccd979bd
MF		 3224 if (status < 0)
3225 mlog_errno(status);
3226
3227 spin_lock_irqsave(&lockres->l_lock, flags);
3228unqueue:
d680efe9 3229 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
ccd979bd
MF		 3230 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
3231 } else
3232 ocfs2_schedule_blocked_lock(osb, lockres);
3233
3234 mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
d680efe9 3235 ctl.requeue ? "yes" : "no");
ccd979bd
MF		 3236 spin_unlock_irqrestore(&lockres->l_lock, flags);
3237
d680efe9
MF		 3238 if (ctl.unblock_action != UNBLOCK_CONTINUE
3239 && lockres->l_ops->post_unlock)
3240 lockres->l_ops->post_unlock(osb, lockres);
3241
ccd979bd
MF		 3242 mlog_exit_void();
3243}
3244
3245static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
3246 struct ocfs2_lock_res *lockres)
3247{
3248 mlog_entry_void();
3249
3250 assert_spin_locked(&lockres->l_lock);
3251
3252 if (lockres->l_flags & OCFS2_LOCK_FREEING) {
3253 /* Do not schedule a lock for downconvert when it's on
3254 * the way to destruction - any nodes wanting access
3255 * to the resource will get it soon. */
3256 mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n",
3257 lockres->l_name, lockres->l_flags);
3258 return;
3259 }
3260
3261 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
3262
34d024f8 3263 spin_lock(&osb->dc_task_lock);
ccd979bd
MF		 3264 if (list_empty(&lockres->l_blocked_list)) {
3265 list_add_tail(&lockres->l_blocked_list,
3266 &osb->blocked_lock_list);
3267 osb->blocked_lock_count++;
3268 }
34d024f8 3269 spin_unlock(&osb->dc_task_lock);
ccd979bd
MF		 3270
3271 mlog_exit_void();
3272}
34d024f8
MF		 3273
3274static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
3275{
3276 unsigned long processed;
3277 struct ocfs2_lock_res *lockres;
3278
3279 mlog_entry_void();
3280
3281 spin_lock(&osb->dc_task_lock);
3282 /* grab this early so we know to try again if a state change and
3283 * wake happens part-way through our work */
3284 osb->dc_work_sequence = osb->dc_wake_sequence;
3285
3286 processed = osb->blocked_lock_count;
3287 while (processed) {
3288 BUG_ON(list_empty(&osb->blocked_lock_list));
3289
3290 lockres = list_entry(osb->blocked_lock_list.next,
3291 struct ocfs2_lock_res, l_blocked_list);
3292 list_del_init(&lockres->l_blocked_list);
3293 osb->blocked_lock_count--;
3294 spin_unlock(&osb->dc_task_lock);
3295
3296 BUG_ON(!processed);
3297 processed--;
3298
3299 ocfs2_process_blocked_lock(osb, lockres);
3300
3301 spin_lock(&osb->dc_task_lock);
3302 }
3303 spin_unlock(&osb->dc_task_lock);
3304
3305 mlog_exit_void();
3306}
3307
3308static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
3309{
3310 int empty = 0;
3311
3312 spin_lock(&osb->dc_task_lock);
3313 if (list_empty(&osb->blocked_lock_list))
3314 empty = 1;
3315
3316 spin_unlock(&osb->dc_task_lock);
3317 return empty;
3318}
3319
3320static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
3321{
3322 int should_wake = 0;
3323
3324 spin_lock(&osb->dc_task_lock);
3325 if (osb->dc_work_sequence != osb->dc_wake_sequence)
3326 should_wake = 1;
3327 spin_unlock(&osb->dc_task_lock);
3328
3329 return should_wake;
3330}
3331
3332int ocfs2_downconvert_thread(void *arg)
3333{
3334 int status = 0;
3335 struct ocfs2_super *osb = arg;
3336
3337 /* only quit once we've been asked to stop and there is no more
3338 * work available */
3339 while (!(kthread_should_stop() &&
3340 ocfs2_downconvert_thread_lists_empty(osb))) {
3341
3342 wait_event_interruptible(osb->dc_event,
3343 ocfs2_downconvert_thread_should_wake(osb) ||
3344 kthread_should_stop());
3345
3346 mlog(0, "downconvert_thread: awoken\n");
3347
3348 ocfs2_downconvert_thread_do_work(osb);
3349 }
3350
3351 osb->dc_task = NULL;
3352 return status;
3353}
3354
3355void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
3356{
3357 spin_lock(&osb->dc_task_lock);
3358 /* make sure the voting thread gets a swipe at whatever changes
3359 * the caller may have made to the voting state */
3360 osb->dc_wake_sequence++;
3361 spin_unlock(&osb->dc_task_lock);
3362 wake_up(&osb->dc_event);
3363}
kernel source for telekom puls (alcatel/mediatek)