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[/] [test_project/] [trunk/] [linux_sd_driver/] [fs/] [ocfs2/] [dlmglue.c] - Blame information for rev 62

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1 62 marcus.erl
/* -*- 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>
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"
48
#include "dcache.h"
49
#include "dlmglue.h"
50
#include "extent_map.h"
51
#include "file.h"
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"
58
#include "vote.h"
59
 
60
#include "buffer_head_io.h"
61
 
62
struct ocfs2_mask_waiter {
63
        struct list_head        mw_item;
64
        int                     mw_status;
65
        struct completion       mw_complete;
66
        unsigned long           mw_mask;
67
        unsigned long           mw_goal;
68
};
69
 
70
static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
71
static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
72
 
73
/*
74
 * Return value from ->downconvert_worker functions.
75
 *
76
 * These control the precise actions of ocfs2_unblock_lock()
77
 * and ocfs2_process_blocked_lock()
78
 *
79
 */
80
enum 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
 
88
struct ocfs2_unblock_ctl {
89
        int requeue;
90
        enum ocfs2_unblock_action unblock_action;
91
};
92
 
93
static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
94
                                        int new_level);
95
static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
96
 
97
static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
98
                                     int blocking);
99
 
100
static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
101
                                       int blocking);
102
 
103
static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
104
                                     struct ocfs2_lock_res *lockres);
105
 
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. */
110
static 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
 
135
/*
136
 * OCFS2 Lock Resource Operations
137
 *
138
 * These fine tune the behavior of the generic dlmglue locking infrastructure.
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).
147
 */
148
struct ocfs2_lock_res_ops {
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 *);
154
 
155
        /*
156
         * Optionally called in the downconvert (or "vote") thread
157
         * after a successful downconvert. The lockres will not be
158
         * referenced after this callback is called, so it is safe to
159
         * free memory, etc.
160
         *
161
         * The exact semantics of when this is called are controlled
162
         * by ->downconvert_worker()
163
         */
164
        void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
165
 
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
 
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
 
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
 
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;
205
};
206
 
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
 
217
/*
218
 * Indicate that a lock type makes use of the lock value block. The
219
 * ->set_lvb lock type callback must be defined.
220
 */
221
#define LOCK_TYPE_USES_LVB              0x2
222
 
223
static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
224
        .get_osb        = ocfs2_get_inode_osb,
225
        .flags          = 0,
226
};
227
 
228
static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
229
        .get_osb        = ocfs2_get_inode_osb,
230
        .check_downconvert = ocfs2_check_meta_downconvert,
231
        .set_lvb        = ocfs2_set_meta_lvb,
232
        .flags          = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
233
};
234
 
235
static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
236
        .get_osb        = ocfs2_get_inode_osb,
237
        .downconvert_worker = ocfs2_data_convert_worker,
238
        .flags          = 0,
239
};
240
 
241
static struct ocfs2_lock_res_ops ocfs2_super_lops = {
242
        .flags          = LOCK_TYPE_REQUIRES_REFRESH,
243
};
244
 
245
static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
246
        .flags          = 0,
247
};
248
 
249
static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
250
        .get_osb        = ocfs2_get_dentry_osb,
251
        .post_unlock    = ocfs2_dentry_post_unlock,
252
        .downconvert_worker = ocfs2_dentry_convert_worker,
253
        .flags          = 0,
254
};
255
 
256
static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
257
        .get_osb        = ocfs2_get_inode_osb,
258
        .flags          = 0,
259
};
260
 
261
static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
262
{
263
        return lockres->l_type == OCFS2_LOCK_TYPE_META ||
264
                lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
265
                lockres->l_type == OCFS2_LOCK_TYPE_RW ||
266
                lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
267
}
268
 
269
static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
270
{
271
        BUG_ON(!ocfs2_is_inode_lock(lockres));
272
 
273
        return (struct inode *) lockres->l_priv;
274
}
275
 
276
static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
277
{
278
        BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
279
 
280
        return (struct ocfs2_dentry_lock *)lockres->l_priv;
281
}
282
 
283
static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
284
{
285
        if (lockres->l_ops->get_osb)
286
                return lockres->l_ops->get_osb(lockres);
287
 
288
        return (struct ocfs2_super *)lockres->l_priv;
289
}
290
 
291
static int ocfs2_lock_create(struct ocfs2_super *osb,
292
                             struct ocfs2_lock_res *lockres,
293
                             int level,
294
                             int dlm_flags);
295
static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
296
                                                     int wanted);
297
static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
298
                                 struct ocfs2_lock_res *lockres,
299
                                 int level);
300
static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
301
static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
302
static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
303
static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
304
static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
305
                                        struct ocfs2_lock_res *lockres);
306
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
307
                                                int convert);
308
#define ocfs2_log_dlm_error(_func, _stat, _lockres) do {        \
309
        mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on "  \
310
                "resource %s: %s\n", dlm_errname(_stat), _func, \
311
                _lockres->l_name, dlm_errmsg(_stat));           \
312
} while (0)
313
static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
314
                                 struct ocfs2_lock_res *lockres);
315
static int ocfs2_meta_lock_update(struct inode *inode,
316
                                  struct buffer_head **bh);
317
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
318
static inline int ocfs2_highest_compat_lock_level(int level);
319
 
320
static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
321
                                  u64 blkno,
322
                                  u32 generation,
323
                                  char *name)
324
{
325
        int len;
326
 
327
        mlog_entry_void();
328
 
329
        BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
330
 
331
        len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
332
                       ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
333
                       (long long)blkno, generation);
334
 
335
        BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
336
 
337
        mlog(0, "built lock resource with name: %s\n", name);
338
 
339
        mlog_exit_void();
340
}
341
 
342
static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
343
 
344
static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
345
                                       struct ocfs2_dlm_debug *dlm_debug)
346
{
347
        mlog(0, "Add tracking for lockres %s\n", res->l_name);
348
 
349
        spin_lock(&ocfs2_dlm_tracking_lock);
350
        list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
351
        spin_unlock(&ocfs2_dlm_tracking_lock);
352
}
353
 
354
static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
355
{
356
        spin_lock(&ocfs2_dlm_tracking_lock);
357
        if (!list_empty(&res->l_debug_list))
358
                list_del_init(&res->l_debug_list);
359
        spin_unlock(&ocfs2_dlm_tracking_lock);
360
}
361
 
362
static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
363
                                       struct ocfs2_lock_res *res,
364
                                       enum ocfs2_lock_type type,
365
                                       struct ocfs2_lock_res_ops *ops,
366
                                       void *priv)
367
{
368
        res->l_type          = type;
369
        res->l_ops           = ops;
370
        res->l_priv          = priv;
371
 
372
        res->l_level         = LKM_IVMODE;
373
        res->l_requested     = LKM_IVMODE;
374
        res->l_blocking      = LKM_IVMODE;
375
        res->l_action        = OCFS2_AST_INVALID;
376
        res->l_unlock_action = OCFS2_UNLOCK_INVALID;
377
 
378
        res->l_flags         = OCFS2_LOCK_INITIALIZED;
379
 
380
        ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
381
}
382
 
383
void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
384
{
385
        /* This also clears out the lock status block */
386
        memset(res, 0, sizeof(struct ocfs2_lock_res));
387
        spin_lock_init(&res->l_lock);
388
        init_waitqueue_head(&res->l_event);
389
        INIT_LIST_HEAD(&res->l_blocked_list);
390
        INIT_LIST_HEAD(&res->l_mask_waiters);
391
}
392
 
393
void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
394
                               enum ocfs2_lock_type type,
395
                               unsigned int generation,
396
                               struct inode *inode)
397
{
398
        struct ocfs2_lock_res_ops *ops;
399
 
400
        switch(type) {
401
                case OCFS2_LOCK_TYPE_RW:
402
                        ops = &ocfs2_inode_rw_lops;
403
                        break;
404
                case OCFS2_LOCK_TYPE_META:
405
                        ops = &ocfs2_inode_meta_lops;
406
                        break;
407
                case OCFS2_LOCK_TYPE_DATA:
408
                        ops = &ocfs2_inode_data_lops;
409
                        break;
410
                case OCFS2_LOCK_TYPE_OPEN:
411
                        ops = &ocfs2_inode_open_lops;
412
                        break;
413
                default:
414
                        mlog_bug_on_msg(1, "type: %d\n", type);
415
                        ops = NULL; /* thanks, gcc */
416
                        break;
417
        };
418
 
419
        ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
420
                              generation, res->l_name);
421
        ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
422
}
423
 
424
static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
425
{
426
        struct inode *inode = ocfs2_lock_res_inode(lockres);
427
 
428
        return OCFS2_SB(inode->i_sb);
429
}
430
 
431
static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
432
{
433
        __be64 inode_blkno_be;
434
 
435
        memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
436
               sizeof(__be64));
437
 
438
        return be64_to_cpu(inode_blkno_be);
439
}
440
 
441
static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
442
{
443
        struct ocfs2_dentry_lock *dl = lockres->l_priv;
444
 
445
        return OCFS2_SB(dl->dl_inode->i_sb);
446
}
447
 
448
void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
449
                                u64 parent, struct inode *inode)
450
{
451
        int len;
452
        u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
453
        __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
454
        struct ocfs2_lock_res *lockres = &dl->dl_lockres;
455
 
456
        ocfs2_lock_res_init_once(lockres);
457
 
458
        /*
459
         * Unfortunately, the standard lock naming scheme won't work
460
         * here because we have two 16 byte values to use. Instead,
461
         * we'll stuff the inode number as a binary value. We still
462
         * want error prints to show something without garbling the
463
         * display, so drop a null byte in there before the inode
464
         * number. A future version of OCFS2 will likely use all
465
         * binary lock names. The stringified names have been a
466
         * tremendous aid in debugging, but now that the debugfs
467
         * interface exists, we can mangle things there if need be.
468
         *
469
         * NOTE: We also drop the standard "pad" value (the total lock
470
         * name size stays the same though - the last part is all
471
         * zeros due to the memset in ocfs2_lock_res_init_once()
472
         */
473
        len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
474
                       "%c%016llx",
475
                       ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
476
                       (long long)parent);
477
 
478
        BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
479
 
480
        memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
481
               sizeof(__be64));
482
 
483
        ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
484
                                   OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
485
                                   dl);
486
}
487
 
488
static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
489
                                      struct ocfs2_super *osb)
490
{
491
        /* Superblock lockres doesn't come from a slab so we call init
492
         * once on it manually.  */
493
        ocfs2_lock_res_init_once(res);
494
        ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
495
                              0, res->l_name);
496
        ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
497
                                   &ocfs2_super_lops, osb);
498
}
499
 
500
static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
501
                                       struct ocfs2_super *osb)
502
{
503
        /* Rename lockres doesn't come from a slab so we call init
504
         * once on it manually.  */
505
        ocfs2_lock_res_init_once(res);
506
        ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
507
        ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
508
                                   &ocfs2_rename_lops, osb);
509
}
510
 
511
void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
512
{
513
        mlog_entry_void();
514
 
515
        if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
516
                return;
517
 
518
        ocfs2_remove_lockres_tracking(res);
519
 
520
        mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
521
                        "Lockres %s is on the blocked list\n",
522
                        res->l_name);
523
        mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
524
                        "Lockres %s has mask waiters pending\n",
525
                        res->l_name);
526
        mlog_bug_on_msg(spin_is_locked(&res->l_lock),
527
                        "Lockres %s is locked\n",
528
                        res->l_name);
529
        mlog_bug_on_msg(res->l_ro_holders,
530
                        "Lockres %s has %u ro holders\n",
531
                        res->l_name, res->l_ro_holders);
532
        mlog_bug_on_msg(res->l_ex_holders,
533
                        "Lockres %s has %u ex holders\n",
534
                        res->l_name, res->l_ex_holders);
535
 
536
        /* Need to clear out the lock status block for the dlm */
537
        memset(&res->l_lksb, 0, sizeof(res->l_lksb));
538
 
539
        res->l_flags = 0UL;
540
        mlog_exit_void();
541
}
542
 
543
static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
544
                                     int level)
545
{
546
        mlog_entry_void();
547
 
548
        BUG_ON(!lockres);
549
 
550
        switch(level) {
551
        case LKM_EXMODE:
552
                lockres->l_ex_holders++;
553
                break;
554
        case LKM_PRMODE:
555
                lockres->l_ro_holders++;
556
                break;
557
        default:
558
                BUG();
559
        }
560
 
561
        mlog_exit_void();
562
}
563
 
564
static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
565
                                     int level)
566
{
567
        mlog_entry_void();
568
 
569
        BUG_ON(!lockres);
570
 
571
        switch(level) {
572
        case LKM_EXMODE:
573
                BUG_ON(!lockres->l_ex_holders);
574
                lockres->l_ex_holders--;
575
                break;
576
        case LKM_PRMODE:
577
                BUG_ON(!lockres->l_ro_holders);
578
                lockres->l_ro_holders--;
579
                break;
580
        default:
581
                BUG();
582
        }
583
        mlog_exit_void();
584
}
585
 
586
/* WARNING: This function lives in a world where the only three lock
587
 * levels are EX, PR, and NL. It *will* have to be adjusted when more
588
 * lock types are added. */
589
static inline int ocfs2_highest_compat_lock_level(int level)
590
{
591
        int new_level = LKM_EXMODE;
592
 
593
        if (level == LKM_EXMODE)
594
                new_level = LKM_NLMODE;
595
        else if (level == LKM_PRMODE)
596
                new_level = LKM_PRMODE;
597
        return new_level;
598
}
599
 
600
static void lockres_set_flags(struct ocfs2_lock_res *lockres,
601
                              unsigned long newflags)
602
{
603
        struct ocfs2_mask_waiter *mw, *tmp;
604
 
605
        assert_spin_locked(&lockres->l_lock);
606
 
607
        lockres->l_flags = newflags;
608
 
609
        list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
610
                if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
611
                        continue;
612
 
613
                list_del_init(&mw->mw_item);
614
                mw->mw_status = 0;
615
                complete(&mw->mw_complete);
616
        }
617
}
618
static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
619
{
620
        lockres_set_flags(lockres, lockres->l_flags | or);
621
}
622
static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
623
                                unsigned long clear)
624
{
625
        lockres_set_flags(lockres, lockres->l_flags & ~clear);
626
}
627
 
628
static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
629
{
630
        mlog_entry_void();
631
 
632
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
633
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
634
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
635
        BUG_ON(lockres->l_blocking <= LKM_NLMODE);
636
 
637
        lockres->l_level = lockres->l_requested;
638
        if (lockres->l_level <=
639
            ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
640
                lockres->l_blocking = LKM_NLMODE;
641
                lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
642
        }
643
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
644
 
645
        mlog_exit_void();
646
}
647
 
648
static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
649
{
650
        mlog_entry_void();
651
 
652
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
653
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
654
 
655
        /* Convert from RO to EX doesn't really need anything as our
656
         * information is already up to data. Convert from NL to
657
         * *anything* however should mark ourselves as needing an
658
         * update */
659
        if (lockres->l_level == LKM_NLMODE &&
660
            lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
661
                lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
662
 
663
        lockres->l_level = lockres->l_requested;
664
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
665
 
666
        mlog_exit_void();
667
}
668
 
669
static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
670
{
671
        mlog_entry_void();
672
 
673
        BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
674
        BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
675
 
676
        if (lockres->l_requested > LKM_NLMODE &&
677
            !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
678
            lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
679
                lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
680
 
681
        lockres->l_level = lockres->l_requested;
682
        lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
683
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
684
 
685
        mlog_exit_void();
686
}
687
 
688
static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
689
                                     int level)
690
{
691
        int needs_downconvert = 0;
692
        mlog_entry_void();
693
 
694
        assert_spin_locked(&lockres->l_lock);
695
 
696
        lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
697
 
698
        if (level > lockres->l_blocking) {
699
                /* only schedule a downconvert if we haven't already scheduled
700
                 * one that goes low enough to satisfy the level we're
701
                 * blocking.  this also catches the case where we get
702
                 * duplicate BASTs */
703
                if (ocfs2_highest_compat_lock_level(level) <
704
                    ocfs2_highest_compat_lock_level(lockres->l_blocking))
705
                        needs_downconvert = 1;
706
 
707
                lockres->l_blocking = level;
708
        }
709
 
710
        mlog_exit(needs_downconvert);
711
        return needs_downconvert;
712
}
713
 
714
static void ocfs2_blocking_ast(void *opaque, int level)
715
{
716
        struct ocfs2_lock_res *lockres = opaque;
717
        struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
718
        int needs_downconvert;
719
        unsigned long flags;
720
 
721
        BUG_ON(level <= LKM_NLMODE);
722
 
723
        mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n",
724
             lockres->l_name, level, lockres->l_level,
725
             ocfs2_lock_type_string(lockres->l_type));
726
 
727
        spin_lock_irqsave(&lockres->l_lock, flags);
728
        needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
729
        if (needs_downconvert)
730
                ocfs2_schedule_blocked_lock(osb, lockres);
731
        spin_unlock_irqrestore(&lockres->l_lock, flags);
732
 
733
        wake_up(&lockres->l_event);
734
 
735
        ocfs2_kick_vote_thread(osb);
736
}
737
 
738
static void ocfs2_locking_ast(void *opaque)
739
{
740
        struct ocfs2_lock_res *lockres = opaque;
741
        struct dlm_lockstatus *lksb = &lockres->l_lksb;
742
        unsigned long flags;
743
 
744
        spin_lock_irqsave(&lockres->l_lock, flags);
745
 
746
        if (lksb->status != DLM_NORMAL) {
747
                mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n",
748
                     lockres->l_name, lksb->status);
749
                spin_unlock_irqrestore(&lockres->l_lock, flags);
750
                return;
751
        }
752
 
753
        switch(lockres->l_action) {
754
        case OCFS2_AST_ATTACH:
755
                ocfs2_generic_handle_attach_action(lockres);
756
                lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
757
                break;
758
        case OCFS2_AST_CONVERT:
759
                ocfs2_generic_handle_convert_action(lockres);
760
                break;
761
        case OCFS2_AST_DOWNCONVERT:
762
                ocfs2_generic_handle_downconvert_action(lockres);
763
                break;
764
        default:
765
                mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u "
766
                     "lockres flags = 0x%lx, unlock action: %u\n",
767
                     lockres->l_name, lockres->l_action, lockres->l_flags,
768
                     lockres->l_unlock_action);
769
                BUG();
770
        }
771
 
772
        /* set it to something invalid so if we get called again we
773
         * can catch it. */
774
        lockres->l_action = OCFS2_AST_INVALID;
775
 
776
        wake_up(&lockres->l_event);
777
        spin_unlock_irqrestore(&lockres->l_lock, flags);
778
}
779
 
780
static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
781
                                                int convert)
782
{
783
        unsigned long flags;
784
 
785
        mlog_entry_void();
786
        spin_lock_irqsave(&lockres->l_lock, flags);
787
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
788
        if (convert)
789
                lockres->l_action = OCFS2_AST_INVALID;
790
        else
791
                lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
792
        spin_unlock_irqrestore(&lockres->l_lock, flags);
793
 
794
        wake_up(&lockres->l_event);
795
        mlog_exit_void();
796
}
797
 
798
/* Note: If we detect another process working on the lock (i.e.,
799
 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
800
 * to do the right thing in that case.
801
 */
802
static int ocfs2_lock_create(struct ocfs2_super *osb,
803
                             struct ocfs2_lock_res *lockres,
804
                             int level,
805
                             int dlm_flags)
806
{
807
        int ret = 0;
808
        enum dlm_status status = DLM_NORMAL;
809
        unsigned long flags;
810
 
811
        mlog_entry_void();
812
 
813
        mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level,
814
             dlm_flags);
815
 
816
        spin_lock_irqsave(&lockres->l_lock, flags);
817
        if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
818
            (lockres->l_flags & OCFS2_LOCK_BUSY)) {
819
                spin_unlock_irqrestore(&lockres->l_lock, flags);
820
                goto bail;
821
        }
822
 
823
        lockres->l_action = OCFS2_AST_ATTACH;
824
        lockres->l_requested = level;
825
        lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
826
        spin_unlock_irqrestore(&lockres->l_lock, flags);
827
 
828
        status = dlmlock(osb->dlm,
829
                         level,
830
                         &lockres->l_lksb,
831
                         dlm_flags,
832
                         lockres->l_name,
833
                         OCFS2_LOCK_ID_MAX_LEN - 1,
834
                         ocfs2_locking_ast,
835
                         lockres,
836
                         ocfs2_blocking_ast);
837
        if (status != DLM_NORMAL) {
838
                ocfs2_log_dlm_error("dlmlock", status, lockres);
839
                ret = -EINVAL;
840
                ocfs2_recover_from_dlm_error(lockres, 1);
841
        }
842
 
843
        mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name);
844
 
845
bail:
846
        mlog_exit(ret);
847
        return ret;
848
}
849
 
850
static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
851
                                        int flag)
852
{
853
        unsigned long flags;
854
        int ret;
855
 
856
        spin_lock_irqsave(&lockres->l_lock, flags);
857
        ret = lockres->l_flags & flag;
858
        spin_unlock_irqrestore(&lockres->l_lock, flags);
859
 
860
        return ret;
861
}
862
 
863
static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
864
 
865
{
866
        wait_event(lockres->l_event,
867
                   !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
868
}
869
 
870
static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
871
 
872
{
873
        wait_event(lockres->l_event,
874
                   !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
875
}
876
 
877
/* predict what lock level we'll be dropping down to on behalf
878
 * of another node, and return true if the currently wanted
879
 * level will be compatible with it. */
880
static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
881
                                                     int wanted)
882
{
883
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
884
 
885
        return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
886
}
887
 
888
static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
889
{
890
        INIT_LIST_HEAD(&mw->mw_item);
891
        init_completion(&mw->mw_complete);
892
}
893
 
894
static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
895
{
896
        wait_for_completion(&mw->mw_complete);
897
        /* Re-arm the completion in case we want to wait on it again */
898
        INIT_COMPLETION(mw->mw_complete);
899
        return mw->mw_status;
900
}
901
 
902
static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
903
                                    struct ocfs2_mask_waiter *mw,
904
                                    unsigned long mask,
905
                                    unsigned long goal)
906
{
907
        BUG_ON(!list_empty(&mw->mw_item));
908
 
909
        assert_spin_locked(&lockres->l_lock);
910
 
911
        list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
912
        mw->mw_mask = mask;
913
        mw->mw_goal = goal;
914
}
915
 
916
/* returns 0 if the mw that was removed was already satisfied, -EBUSY
917
 * if the mask still hadn't reached its goal */
918
static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
919
                                      struct ocfs2_mask_waiter *mw)
920
{
921
        unsigned long flags;
922
        int ret = 0;
923
 
924
        spin_lock_irqsave(&lockres->l_lock, flags);
925
        if (!list_empty(&mw->mw_item)) {
926
                if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
927
                        ret = -EBUSY;
928
 
929
                list_del_init(&mw->mw_item);
930
                init_completion(&mw->mw_complete);
931
        }
932
        spin_unlock_irqrestore(&lockres->l_lock, flags);
933
 
934
        return ret;
935
 
936
}
937
 
938
static int ocfs2_cluster_lock(struct ocfs2_super *osb,
939
                              struct ocfs2_lock_res *lockres,
940
                              int level,
941
                              int lkm_flags,
942
                              int arg_flags)
943
{
944
        struct ocfs2_mask_waiter mw;
945
        enum dlm_status status;
946
        int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
947
        int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
948
        unsigned long flags;
949
 
950
        mlog_entry_void();
951
 
952
        ocfs2_init_mask_waiter(&mw);
953
 
954
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
955
                lkm_flags |= LKM_VALBLK;
956
 
957
again:
958
        wait = 0;
959
 
960
        if (catch_signals && signal_pending(current)) {
961
                ret = -ERESTARTSYS;
962
                goto out;
963
        }
964
 
965
        spin_lock_irqsave(&lockres->l_lock, flags);
966
 
967
        mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
968
                        "Cluster lock called on freeing lockres %s! flags "
969
                        "0x%lx\n", lockres->l_name, lockres->l_flags);
970
 
971
        /* We only compare against the currently granted level
972
         * here. If the lock is blocked waiting on a downconvert,
973
         * we'll get caught below. */
974
        if (lockres->l_flags & OCFS2_LOCK_BUSY &&
975
            level > lockres->l_level) {
976
                /* is someone sitting in dlm_lock? If so, wait on
977
                 * them. */
978
                lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
979
                wait = 1;
980
                goto unlock;
981
        }
982
 
983
        if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
984
            !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
985
                /* is the lock is currently blocked on behalf of
986
                 * another node */
987
                lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
988
                wait = 1;
989
                goto unlock;
990
        }
991
 
992
        if (level > lockres->l_level) {
993
                if (lockres->l_action != OCFS2_AST_INVALID)
994
                        mlog(ML_ERROR, "lockres %s has action %u pending\n",
995
                             lockres->l_name, lockres->l_action);
996
 
997
                if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
998
                        lockres->l_action = OCFS2_AST_ATTACH;
999
                        lkm_flags &= ~LKM_CONVERT;
1000
                } else {
1001
                        lockres->l_action = OCFS2_AST_CONVERT;
1002
                        lkm_flags |= LKM_CONVERT;
1003
                }
1004
 
1005
                lockres->l_requested = level;
1006
                lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
1007
                spin_unlock_irqrestore(&lockres->l_lock, flags);
1008
 
1009
                BUG_ON(level == LKM_IVMODE);
1010
                BUG_ON(level == LKM_NLMODE);
1011
 
1012
                mlog(0, "lock %s, convert from %d to level = %d\n",
1013
                     lockres->l_name, lockres->l_level, level);
1014
 
1015
                /* call dlm_lock to upgrade lock now */
1016
                status = dlmlock(osb->dlm,
1017
                                 level,
1018
                                 &lockres->l_lksb,
1019
                                 lkm_flags,
1020
                                 lockres->l_name,
1021
                                 OCFS2_LOCK_ID_MAX_LEN - 1,
1022
                                 ocfs2_locking_ast,
1023
                                 lockres,
1024
                                 ocfs2_blocking_ast);
1025
                if (status != DLM_NORMAL) {
1026
                        if ((lkm_flags & LKM_NOQUEUE) &&
1027
                            (status == DLM_NOTQUEUED))
1028
                                ret = -EAGAIN;
1029
                        else {
1030
                                ocfs2_log_dlm_error("dlmlock", status,
1031
                                                    lockres);
1032
                                ret = -EINVAL;
1033
                        }
1034
                        ocfs2_recover_from_dlm_error(lockres, 1);
1035
                        goto out;
1036
                }
1037
 
1038
                mlog(0, "lock %s, successfull return from dlmlock\n",
1039
                     lockres->l_name);
1040
 
1041
                /* At this point we've gone inside the dlm and need to
1042
                 * complete our work regardless. */
1043
                catch_signals = 0;
1044
 
1045
                /* wait for busy to clear and carry on */
1046
                goto again;
1047
        }
1048
 
1049
        /* Ok, if we get here then we're good to go. */
1050
        ocfs2_inc_holders(lockres, level);
1051
 
1052
        ret = 0;
1053
unlock:
1054
        spin_unlock_irqrestore(&lockres->l_lock, flags);
1055
out:
1056
        /*
1057
         * This is helping work around a lock inversion between the page lock
1058
         * and dlm locks.  One path holds the page lock while calling aops
1059
         * which block acquiring dlm locks.  The voting thread holds dlm
1060
         * locks while acquiring page locks while down converting data locks.
1061
         * This block is helping an aop path notice the inversion and back
1062
         * off to unlock its page lock before trying the dlm lock again.
1063
         */
1064
        if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
1065
            mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
1066
                wait = 0;
1067
                if (lockres_remove_mask_waiter(lockres, &mw))
1068
                        ret = -EAGAIN;
1069
                else
1070
                        goto again;
1071
        }
1072
        if (wait) {
1073
                ret = ocfs2_wait_for_mask(&mw);
1074
                if (ret == 0)
1075
                        goto again;
1076
                mlog_errno(ret);
1077
        }
1078
 
1079
        mlog_exit(ret);
1080
        return ret;
1081
}
1082
 
1083
static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
1084
                                 struct ocfs2_lock_res *lockres,
1085
                                 int level)
1086
{
1087
        unsigned long flags;
1088
 
1089
        mlog_entry_void();
1090
        spin_lock_irqsave(&lockres->l_lock, flags);
1091
        ocfs2_dec_holders(lockres, level);
1092
        ocfs2_vote_on_unlock(osb, lockres);
1093
        spin_unlock_irqrestore(&lockres->l_lock, flags);
1094
        mlog_exit_void();
1095
}
1096
 
1097
static int ocfs2_create_new_lock(struct ocfs2_super *osb,
1098
                                 struct ocfs2_lock_res *lockres,
1099
                                 int ex,
1100
                                 int local)
1101
{
1102
        int level =  ex ? LKM_EXMODE : LKM_PRMODE;
1103
        unsigned long flags;
1104
        int lkm_flags = local ? LKM_LOCAL : 0;
1105
 
1106
        spin_lock_irqsave(&lockres->l_lock, flags);
1107
        BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
1108
        lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
1109
        spin_unlock_irqrestore(&lockres->l_lock, flags);
1110
 
1111
        return ocfs2_lock_create(osb, lockres, level, lkm_flags);
1112
}
1113
 
1114
/* Grants us an EX lock on the data and metadata resources, skipping
1115
 * the normal cluster directory lookup. Use this ONLY on newly created
1116
 * inodes which other nodes can't possibly see, and which haven't been
1117
 * hashed in the inode hash yet. This can give us a good performance
1118
 * increase as it'll skip the network broadcast normally associated
1119
 * with creating a new lock resource. */
1120
int ocfs2_create_new_inode_locks(struct inode *inode)
1121
{
1122
        int ret;
1123
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1124
 
1125
        BUG_ON(!inode);
1126
        BUG_ON(!ocfs2_inode_is_new(inode));
1127
 
1128
        mlog_entry_void();
1129
 
1130
        mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
1131
 
1132
        /* NOTE: That we don't increment any of the holder counts, nor
1133
         * do we add anything to a journal handle. Since this is
1134
         * supposed to be a new inode which the cluster doesn't know
1135
         * about yet, there is no need to.  As far as the LVB handling
1136
         * is concerned, this is basically like acquiring an EX lock
1137
         * on a resource which has an invalid one -- we'll set it
1138
         * valid when we release the EX. */
1139
 
1140
        ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
1141
        if (ret) {
1142
                mlog_errno(ret);
1143
                goto bail;
1144
        }
1145
 
1146
        /*
1147
         * We don't want to use LKM_LOCAL on a meta data lock as they
1148
         * don't use a generation in their lock names.
1149
         */
1150
        ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0);
1151
        if (ret) {
1152
                mlog_errno(ret);
1153
                goto bail;
1154
        }
1155
 
1156
        ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1);
1157
        if (ret) {
1158
                mlog_errno(ret);
1159
                goto bail;
1160
        }
1161
 
1162
        ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
1163
        if (ret) {
1164
                mlog_errno(ret);
1165
                goto bail;
1166
        }
1167
 
1168
bail:
1169
        mlog_exit(ret);
1170
        return ret;
1171
}
1172
 
1173
int ocfs2_rw_lock(struct inode *inode, int write)
1174
{
1175
        int status, level;
1176
        struct ocfs2_lock_res *lockres;
1177
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1178
 
1179
        BUG_ON(!inode);
1180
 
1181
        mlog_entry_void();
1182
 
1183
        mlog(0, "inode %llu take %s RW lock\n",
1184
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1185
             write ? "EXMODE" : "PRMODE");
1186
 
1187
        if (ocfs2_mount_local(osb))
1188
                return 0;
1189
 
1190
        lockres = &OCFS2_I(inode)->ip_rw_lockres;
1191
 
1192
        level = write ? LKM_EXMODE : LKM_PRMODE;
1193
 
1194
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
1195
                                    0);
1196
        if (status < 0)
1197
                mlog_errno(status);
1198
 
1199
        mlog_exit(status);
1200
        return status;
1201
}
1202
 
1203
void ocfs2_rw_unlock(struct inode *inode, int write)
1204
{
1205
        int level = write ? LKM_EXMODE : LKM_PRMODE;
1206
        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
1207
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1208
 
1209
        mlog_entry_void();
1210
 
1211
        mlog(0, "inode %llu drop %s RW lock\n",
1212
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1213
             write ? "EXMODE" : "PRMODE");
1214
 
1215
        if (!ocfs2_mount_local(osb))
1216
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
1217
 
1218
        mlog_exit_void();
1219
}
1220
 
1221
/*
1222
 * ocfs2_open_lock always get PR mode lock.
1223
 */
1224
int ocfs2_open_lock(struct inode *inode)
1225
{
1226
        int status = 0;
1227
        struct ocfs2_lock_res *lockres;
1228
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1229
 
1230
        BUG_ON(!inode);
1231
 
1232
        mlog_entry_void();
1233
 
1234
        mlog(0, "inode %llu take PRMODE open lock\n",
1235
             (unsigned long long)OCFS2_I(inode)->ip_blkno);
1236
 
1237
        if (ocfs2_mount_local(osb))
1238
                goto out;
1239
 
1240
        lockres = &OCFS2_I(inode)->ip_open_lockres;
1241
 
1242
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
1243
                                    LKM_PRMODE, 0, 0);
1244
        if (status < 0)
1245
                mlog_errno(status);
1246
 
1247
out:
1248
        mlog_exit(status);
1249
        return status;
1250
}
1251
 
1252
int ocfs2_try_open_lock(struct inode *inode, int write)
1253
{
1254
        int status = 0, level;
1255
        struct ocfs2_lock_res *lockres;
1256
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1257
 
1258
        BUG_ON(!inode);
1259
 
1260
        mlog_entry_void();
1261
 
1262
        mlog(0, "inode %llu try to take %s open lock\n",
1263
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1264
             write ? "EXMODE" : "PRMODE");
1265
 
1266
        if (ocfs2_mount_local(osb))
1267
                goto out;
1268
 
1269
        lockres = &OCFS2_I(inode)->ip_open_lockres;
1270
 
1271
        level = write ? LKM_EXMODE : LKM_PRMODE;
1272
 
1273
        /*
1274
         * The file system may already holding a PRMODE/EXMODE open lock.
1275
         * Since we pass LKM_NOQUEUE, the request won't block waiting on
1276
         * other nodes and the -EAGAIN will indicate to the caller that
1277
         * this inode is still in use.
1278
         */
1279
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
1280
                                    level, LKM_NOQUEUE, 0);
1281
 
1282
out:
1283
        mlog_exit(status);
1284
        return status;
1285
}
1286
 
1287
/*
1288
 * ocfs2_open_unlock unlock PR and EX mode open locks.
1289
 */
1290
void ocfs2_open_unlock(struct inode *inode)
1291
{
1292
        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
1293
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1294
 
1295
        mlog_entry_void();
1296
 
1297
        mlog(0, "inode %llu drop open lock\n",
1298
             (unsigned long long)OCFS2_I(inode)->ip_blkno);
1299
 
1300
        if (ocfs2_mount_local(osb))
1301
                goto out;
1302
 
1303
        if(lockres->l_ro_holders)
1304
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
1305
                                     LKM_PRMODE);
1306
        if(lockres->l_ex_holders)
1307
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
1308
                                     LKM_EXMODE);
1309
 
1310
out:
1311
        mlog_exit_void();
1312
}
1313
 
1314
int ocfs2_data_lock_full(struct inode *inode,
1315
                         int write,
1316
                         int arg_flags)
1317
{
1318
        int status = 0, level;
1319
        struct ocfs2_lock_res *lockres;
1320
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1321
 
1322
        BUG_ON(!inode);
1323
 
1324
        mlog_entry_void();
1325
 
1326
        mlog(0, "inode %llu take %s DATA lock\n",
1327
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1328
             write ? "EXMODE" : "PRMODE");
1329
 
1330
        /* We'll allow faking a readonly data lock for
1331
         * rodevices. */
1332
        if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) {
1333
                if (write) {
1334
                        status = -EROFS;
1335
                        mlog_errno(status);
1336
                }
1337
                goto out;
1338
        }
1339
 
1340
        if (ocfs2_mount_local(osb))
1341
                goto out;
1342
 
1343
        lockres = &OCFS2_I(inode)->ip_data_lockres;
1344
 
1345
        level = write ? LKM_EXMODE : LKM_PRMODE;
1346
 
1347
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level,
1348
                                    0, arg_flags);
1349
        if (status < 0 && status != -EAGAIN)
1350
                mlog_errno(status);
1351
 
1352
out:
1353
        mlog_exit(status);
1354
        return status;
1355
}
1356
 
1357
/* see ocfs2_meta_lock_with_page() */
1358
int ocfs2_data_lock_with_page(struct inode *inode,
1359
                              int write,
1360
                              struct page *page)
1361
{
1362
        int ret;
1363
 
1364
        ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK);
1365
        if (ret == -EAGAIN) {
1366
                unlock_page(page);
1367
                if (ocfs2_data_lock(inode, write) == 0)
1368
                        ocfs2_data_unlock(inode, write);
1369
                ret = AOP_TRUNCATED_PAGE;
1370
        }
1371
 
1372
        return ret;
1373
}
1374
 
1375
static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
1376
                                 struct ocfs2_lock_res *lockres)
1377
{
1378
        int kick = 0;
1379
 
1380
        mlog_entry_void();
1381
 
1382
        /* If we know that another node is waiting on our lock, kick
1383
         * the vote thread * pre-emptively when we reach a release
1384
         * condition. */
1385
        if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
1386
                switch(lockres->l_blocking) {
1387
                case LKM_EXMODE:
1388
                        if (!lockres->l_ex_holders && !lockres->l_ro_holders)
1389
                                kick = 1;
1390
                        break;
1391
                case LKM_PRMODE:
1392
                        if (!lockres->l_ex_holders)
1393
                                kick = 1;
1394
                        break;
1395
                default:
1396
                        BUG();
1397
                }
1398
        }
1399
 
1400
        if (kick)
1401
                ocfs2_kick_vote_thread(osb);
1402
 
1403
        mlog_exit_void();
1404
}
1405
 
1406
void ocfs2_data_unlock(struct inode *inode,
1407
                       int write)
1408
{
1409
        int level = write ? LKM_EXMODE : LKM_PRMODE;
1410
        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres;
1411
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1412
 
1413
        mlog_entry_void();
1414
 
1415
        mlog(0, "inode %llu drop %s DATA lock\n",
1416
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1417
             write ? "EXMODE" : "PRMODE");
1418
 
1419
        if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
1420
            !ocfs2_mount_local(osb))
1421
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
1422
 
1423
        mlog_exit_void();
1424
}
1425
 
1426
#define OCFS2_SEC_BITS   34
1427
#define OCFS2_SEC_SHIFT  (64 - 34)
1428
#define OCFS2_NSEC_MASK  ((1ULL << OCFS2_SEC_SHIFT) - 1)
1429
 
1430
/* LVB only has room for 64 bits of time here so we pack it for
1431
 * now. */
1432
static u64 ocfs2_pack_timespec(struct timespec *spec)
1433
{
1434
        u64 res;
1435
        u64 sec = spec->tv_sec;
1436
        u32 nsec = spec->tv_nsec;
1437
 
1438
        res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
1439
 
1440
        return res;
1441
}
1442
 
1443
/* Call this with the lockres locked. I am reasonably sure we don't
1444
 * need ip_lock in this function as anyone who would be changing those
1445
 * values is supposed to be blocked in ocfs2_meta_lock right now. */
1446
static void __ocfs2_stuff_meta_lvb(struct inode *inode)
1447
{
1448
        struct ocfs2_inode_info *oi = OCFS2_I(inode);
1449
        struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
1450
        struct ocfs2_meta_lvb *lvb;
1451
 
1452
        mlog_entry_void();
1453
 
1454
        lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
1455
 
1456
        /*
1457
         * Invalidate the LVB of a deleted inode - this way other
1458
         * nodes are forced to go to disk and discover the new inode
1459
         * status.
1460
         */
1461
        if (oi->ip_flags & OCFS2_INODE_DELETED) {
1462
                lvb->lvb_version = 0;
1463
                goto out;
1464
        }
1465
 
1466
        lvb->lvb_version   = OCFS2_LVB_VERSION;
1467
        lvb->lvb_isize     = cpu_to_be64(i_size_read(inode));
1468
        lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
1469
        lvb->lvb_iuid      = cpu_to_be32(inode->i_uid);
1470
        lvb->lvb_igid      = cpu_to_be32(inode->i_gid);
1471
        lvb->lvb_imode     = cpu_to_be16(inode->i_mode);
1472
        lvb->lvb_inlink    = cpu_to_be16(inode->i_nlink);
1473
        lvb->lvb_iatime_packed  =
1474
                cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
1475
        lvb->lvb_ictime_packed =
1476
                cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
1477
        lvb->lvb_imtime_packed =
1478
                cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
1479
        lvb->lvb_iattr    = cpu_to_be32(oi->ip_attr);
1480
        lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
1481
        lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
1482
 
1483
out:
1484
        mlog_meta_lvb(0, lockres);
1485
 
1486
        mlog_exit_void();
1487
}
1488
 
1489
static void ocfs2_unpack_timespec(struct timespec *spec,
1490
                                  u64 packed_time)
1491
{
1492
        spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
1493
        spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
1494
}
1495
 
1496
static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
1497
{
1498
        struct ocfs2_inode_info *oi = OCFS2_I(inode);
1499
        struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
1500
        struct ocfs2_meta_lvb *lvb;
1501
 
1502
        mlog_entry_void();
1503
 
1504
        mlog_meta_lvb(0, lockres);
1505
 
1506
        lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
1507
 
1508
        /* We're safe here without the lockres lock... */
1509
        spin_lock(&oi->ip_lock);
1510
        oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
1511
        i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
1512
 
1513
        oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
1514
        oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
1515
        ocfs2_set_inode_flags(inode);
1516
 
1517
        /* fast-symlinks are a special case */
1518
        if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
1519
                inode->i_blocks = 0;
1520
        else
1521
                inode->i_blocks = ocfs2_inode_sector_count(inode);
1522
 
1523
        inode->i_uid     = be32_to_cpu(lvb->lvb_iuid);
1524
        inode->i_gid     = be32_to_cpu(lvb->lvb_igid);
1525
        inode->i_mode    = be16_to_cpu(lvb->lvb_imode);
1526
        inode->i_nlink   = be16_to_cpu(lvb->lvb_inlink);
1527
        ocfs2_unpack_timespec(&inode->i_atime,
1528
                              be64_to_cpu(lvb->lvb_iatime_packed));
1529
        ocfs2_unpack_timespec(&inode->i_mtime,
1530
                              be64_to_cpu(lvb->lvb_imtime_packed));
1531
        ocfs2_unpack_timespec(&inode->i_ctime,
1532
                              be64_to_cpu(lvb->lvb_ictime_packed));
1533
        spin_unlock(&oi->ip_lock);
1534
 
1535
        mlog_exit_void();
1536
}
1537
 
1538
static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
1539
                                              struct ocfs2_lock_res *lockres)
1540
{
1541
        struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
1542
 
1543
        if (lvb->lvb_version == OCFS2_LVB_VERSION
1544
            && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
1545
                return 1;
1546
        return 0;
1547
}
1548
 
1549
/* Determine whether a lock resource needs to be refreshed, and
1550
 * arbitrate who gets to refresh it.
1551
 *
1552
 *   0 means no refresh needed.
1553
 *
1554
 *   > 0 means you need to refresh this and you MUST call
1555
 *   ocfs2_complete_lock_res_refresh afterwards. */
1556
static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
1557
{
1558
        unsigned long flags;
1559
        int status = 0;
1560
 
1561
        mlog_entry_void();
1562
 
1563
refresh_check:
1564
        spin_lock_irqsave(&lockres->l_lock, flags);
1565
        if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
1566
                spin_unlock_irqrestore(&lockres->l_lock, flags);
1567
                goto bail;
1568
        }
1569
 
1570
        if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
1571
                spin_unlock_irqrestore(&lockres->l_lock, flags);
1572
 
1573
                ocfs2_wait_on_refreshing_lock(lockres);
1574
                goto refresh_check;
1575
        }
1576
 
1577
        /* Ok, I'll be the one to refresh this lock. */
1578
        lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
1579
        spin_unlock_irqrestore(&lockres->l_lock, flags);
1580
 
1581
        status = 1;
1582
bail:
1583
        mlog_exit(status);
1584
        return status;
1585
}
1586
 
1587
/* If status is non zero, I'll mark it as not being in refresh
1588
 * anymroe, but i won't clear the needs refresh flag. */
1589
static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
1590
                                                   int status)
1591
{
1592
        unsigned long flags;
1593
        mlog_entry_void();
1594
 
1595
        spin_lock_irqsave(&lockres->l_lock, flags);
1596
        lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
1597
        if (!status)
1598
                lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
1599
        spin_unlock_irqrestore(&lockres->l_lock, flags);
1600
 
1601
        wake_up(&lockres->l_event);
1602
 
1603
        mlog_exit_void();
1604
}
1605
 
1606
/* may or may not return a bh if it went to disk. */
1607
static int ocfs2_meta_lock_update(struct inode *inode,
1608
                                  struct buffer_head **bh)
1609
{
1610
        int status = 0;
1611
        struct ocfs2_inode_info *oi = OCFS2_I(inode);
1612
        struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
1613
        struct ocfs2_dinode *fe;
1614
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1615
 
1616
        mlog_entry_void();
1617
 
1618
        if (ocfs2_mount_local(osb))
1619
                goto bail;
1620
 
1621
        spin_lock(&oi->ip_lock);
1622
        if (oi->ip_flags & OCFS2_INODE_DELETED) {
1623
                mlog(0, "Orphaned inode %llu was deleted while we "
1624
                     "were waiting on a lock. ip_flags = 0x%x\n",
1625
                     (unsigned long long)oi->ip_blkno, oi->ip_flags);
1626
                spin_unlock(&oi->ip_lock);
1627
                status = -ENOENT;
1628
                goto bail;
1629
        }
1630
        spin_unlock(&oi->ip_lock);
1631
 
1632
        if (!ocfs2_should_refresh_lock_res(lockres))
1633
                goto bail;
1634
 
1635
        /* This will discard any caching information we might have had
1636
         * for the inode metadata. */
1637
        ocfs2_metadata_cache_purge(inode);
1638
 
1639
        ocfs2_extent_map_trunc(inode, 0);
1640
 
1641
        if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
1642
                mlog(0, "Trusting LVB on inode %llu\n",
1643
                     (unsigned long long)oi->ip_blkno);
1644
                ocfs2_refresh_inode_from_lvb(inode);
1645
        } else {
1646
                /* Boo, we have to go to disk. */
1647
                /* read bh, cast, ocfs2_refresh_inode */
1648
                status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno,
1649
                                          bh, OCFS2_BH_CACHED, inode);
1650
                if (status < 0) {
1651
                        mlog_errno(status);
1652
                        goto bail_refresh;
1653
                }
1654
                fe = (struct ocfs2_dinode *) (*bh)->b_data;
1655
 
1656
                /* This is a good chance to make sure we're not
1657
                 * locking an invalid object.
1658
                 *
1659
                 * We bug on a stale inode here because we checked
1660
                 * above whether it was wiped from disk. The wiping
1661
                 * node provides a guarantee that we receive that
1662
                 * message and can mark the inode before dropping any
1663
                 * locks associated with it. */
1664
                if (!OCFS2_IS_VALID_DINODE(fe)) {
1665
                        OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
1666
                        status = -EIO;
1667
                        goto bail_refresh;
1668
                }
1669
                mlog_bug_on_msg(inode->i_generation !=
1670
                                le32_to_cpu(fe->i_generation),
1671
                                "Invalid dinode %llu disk generation: %u "
1672
                                "inode->i_generation: %u\n",
1673
                                (unsigned long long)oi->ip_blkno,
1674
                                le32_to_cpu(fe->i_generation),
1675
                                inode->i_generation);
1676
                mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
1677
                                !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
1678
                                "Stale dinode %llu dtime: %llu flags: 0x%x\n",
1679
                                (unsigned long long)oi->ip_blkno,
1680
                                (unsigned long long)le64_to_cpu(fe->i_dtime),
1681
                                le32_to_cpu(fe->i_flags));
1682
 
1683
                ocfs2_refresh_inode(inode, fe);
1684
        }
1685
 
1686
        status = 0;
1687
bail_refresh:
1688
        ocfs2_complete_lock_res_refresh(lockres, status);
1689
bail:
1690
        mlog_exit(status);
1691
        return status;
1692
}
1693
 
1694
static int ocfs2_assign_bh(struct inode *inode,
1695
                           struct buffer_head **ret_bh,
1696
                           struct buffer_head *passed_bh)
1697
{
1698
        int status;
1699
 
1700
        if (passed_bh) {
1701
                /* Ok, the update went to disk for us, use the
1702
                 * returned bh. */
1703
                *ret_bh = passed_bh;
1704
                get_bh(*ret_bh);
1705
 
1706
                return 0;
1707
        }
1708
 
1709
        status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
1710
                                  OCFS2_I(inode)->ip_blkno,
1711
                                  ret_bh,
1712
                                  OCFS2_BH_CACHED,
1713
                                  inode);
1714
        if (status < 0)
1715
                mlog_errno(status);
1716
 
1717
        return status;
1718
}
1719
 
1720
/*
1721
 * returns < 0 error if the callback will never be called, otherwise
1722
 * the result of the lock will be communicated via the callback.
1723
 */
1724
int ocfs2_meta_lock_full(struct inode *inode,
1725
                         struct buffer_head **ret_bh,
1726
                         int ex,
1727
                         int arg_flags)
1728
{
1729
        int status, level, dlm_flags, acquired;
1730
        struct ocfs2_lock_res *lockres = NULL;
1731
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1732
        struct buffer_head *local_bh = NULL;
1733
 
1734
        BUG_ON(!inode);
1735
 
1736
        mlog_entry_void();
1737
 
1738
        mlog(0, "inode %llu, take %s META lock\n",
1739
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1740
             ex ? "EXMODE" : "PRMODE");
1741
 
1742
        status = 0;
1743
        acquired = 0;
1744
        /* We'll allow faking a readonly metadata lock for
1745
         * rodevices. */
1746
        if (ocfs2_is_hard_readonly(osb)) {
1747
                if (ex)
1748
                        status = -EROFS;
1749
                goto bail;
1750
        }
1751
 
1752
        if (ocfs2_mount_local(osb))
1753
                goto local;
1754
 
1755
        if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
1756
                wait_event(osb->recovery_event,
1757
                           ocfs2_node_map_is_empty(osb, &osb->recovery_map));
1758
 
1759
        lockres = &OCFS2_I(inode)->ip_meta_lockres;
1760
        level = ex ? LKM_EXMODE : LKM_PRMODE;
1761
        dlm_flags = 0;
1762
        if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
1763
                dlm_flags |= LKM_NOQUEUE;
1764
 
1765
        status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags);
1766
        if (status < 0) {
1767
                if (status != -EAGAIN && status != -EIOCBRETRY)
1768
                        mlog_errno(status);
1769
                goto bail;
1770
        }
1771
 
1772
        /* Notify the error cleanup path to drop the cluster lock. */
1773
        acquired = 1;
1774
 
1775
        /* We wait twice because a node may have died while we were in
1776
         * the lower dlm layers. The second time though, we've
1777
         * committed to owning this lock so we don't allow signals to
1778
         * abort the operation. */
1779
        if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
1780
                wait_event(osb->recovery_event,
1781
                           ocfs2_node_map_is_empty(osb, &osb->recovery_map));
1782
 
1783
local:
1784
        /*
1785
         * We only see this flag if we're being called from
1786
         * ocfs2_read_locked_inode(). It means we're locking an inode
1787
         * which hasn't been populated yet, so clear the refresh flag
1788
         * and let the caller handle it.
1789
         */
1790
        if (inode->i_state & I_NEW) {
1791
                status = 0;
1792
                if (lockres)
1793
                        ocfs2_complete_lock_res_refresh(lockres, 0);
1794
                goto bail;
1795
        }
1796
 
1797
        /* This is fun. The caller may want a bh back, or it may
1798
         * not. ocfs2_meta_lock_update definitely wants one in, but
1799
         * may or may not read one, depending on what's in the
1800
         * LVB. The result of all of this is that we've *only* gone to
1801
         * disk if we have to, so the complexity is worthwhile. */
1802
        status = ocfs2_meta_lock_update(inode, &local_bh);
1803
        if (status < 0) {
1804
                if (status != -ENOENT)
1805
                        mlog_errno(status);
1806
                goto bail;
1807
        }
1808
 
1809
        if (ret_bh) {
1810
                status = ocfs2_assign_bh(inode, ret_bh, local_bh);
1811
                if (status < 0) {
1812
                        mlog_errno(status);
1813
                        goto bail;
1814
                }
1815
        }
1816
 
1817
bail:
1818
        if (status < 0) {
1819
                if (ret_bh && (*ret_bh)) {
1820
                        brelse(*ret_bh);
1821
                        *ret_bh = NULL;
1822
                }
1823
                if (acquired)
1824
                        ocfs2_meta_unlock(inode, ex);
1825
        }
1826
 
1827
        if (local_bh)
1828
                brelse(local_bh);
1829
 
1830
        mlog_exit(status);
1831
        return status;
1832
}
1833
 
1834
/*
1835
 * This is working around a lock inversion between tasks acquiring DLM locks
1836
 * while holding a page lock and the vote thread which blocks dlm lock acquiry
1837
 * while acquiring page locks.
1838
 *
1839
 * ** These _with_page variantes are only intended to be called from aop
1840
 * methods that hold page locks and return a very specific *positive* error
1841
 * code that aop methods pass up to the VFS -- test for errors with != 0. **
1842
 *
1843
 * The DLM is called such that it returns -EAGAIN if it would have blocked
1844
 * waiting for the vote thread.  In that case we unlock our page so the vote
1845
 * thread can make progress.  Once we've done this we have to return
1846
 * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up
1847
 * into the VFS who will then immediately retry the aop call.
1848
 *
1849
 * We do a blocking lock and immediate unlock before returning, though, so that
1850
 * the lock has a great chance of being cached on this node by the time the VFS
1851
 * calls back to retry the aop.    This has a potential to livelock as nodes
1852
 * ping locks back and forth, but that's a risk we're willing to take to avoid
1853
 * the lock inversion simply.
1854
 */
1855
int ocfs2_meta_lock_with_page(struct inode *inode,
1856
                              struct buffer_head **ret_bh,
1857
                              int ex,
1858
                              struct page *page)
1859
{
1860
        int ret;
1861
 
1862
        ret = ocfs2_meta_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
1863
        if (ret == -EAGAIN) {
1864
                unlock_page(page);
1865
                if (ocfs2_meta_lock(inode, ret_bh, ex) == 0)
1866
                        ocfs2_meta_unlock(inode, ex);
1867
                ret = AOP_TRUNCATED_PAGE;
1868
        }
1869
 
1870
        return ret;
1871
}
1872
 
1873
int ocfs2_meta_lock_atime(struct inode *inode,
1874
                          struct vfsmount *vfsmnt,
1875
                          int *level)
1876
{
1877
        int ret;
1878
 
1879
        mlog_entry_void();
1880
        ret = ocfs2_meta_lock(inode, NULL, 0);
1881
        if (ret < 0) {
1882
                mlog_errno(ret);
1883
                return ret;
1884
        }
1885
 
1886
        /*
1887
         * If we should update atime, we will get EX lock,
1888
         * otherwise we just get PR lock.
1889
         */
1890
        if (ocfs2_should_update_atime(inode, vfsmnt)) {
1891
                struct buffer_head *bh = NULL;
1892
 
1893
                ocfs2_meta_unlock(inode, 0);
1894
                ret = ocfs2_meta_lock(inode, &bh, 1);
1895
                if (ret < 0) {
1896
                        mlog_errno(ret);
1897
                        return ret;
1898
                }
1899
                *level = 1;
1900
                if (ocfs2_should_update_atime(inode, vfsmnt))
1901
                        ocfs2_update_inode_atime(inode, bh);
1902
                if (bh)
1903
                        brelse(bh);
1904
        } else
1905
                *level = 0;
1906
 
1907
        mlog_exit(ret);
1908
        return ret;
1909
}
1910
 
1911
void ocfs2_meta_unlock(struct inode *inode,
1912
                       int ex)
1913
{
1914
        int level = ex ? LKM_EXMODE : LKM_PRMODE;
1915
        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
1916
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1917
 
1918
        mlog_entry_void();
1919
 
1920
        mlog(0, "inode %llu drop %s META lock\n",
1921
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1922
             ex ? "EXMODE" : "PRMODE");
1923
 
1924
        if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
1925
            !ocfs2_mount_local(osb))
1926
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
1927
 
1928
        mlog_exit_void();
1929
}
1930
 
1931
int ocfs2_super_lock(struct ocfs2_super *osb,
1932
                     int ex)
1933
{
1934
        int status = 0;
1935
        int level = ex ? LKM_EXMODE : LKM_PRMODE;
1936
        struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
1937
        struct buffer_head *bh;
1938
        struct ocfs2_slot_info *si = osb->slot_info;
1939
 
1940
        mlog_entry_void();
1941
 
1942
        if (ocfs2_is_hard_readonly(osb))
1943
                return -EROFS;
1944
 
1945
        if (ocfs2_mount_local(osb))
1946
                goto bail;
1947
 
1948
        status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
1949
        if (status < 0) {
1950
                mlog_errno(status);
1951
                goto bail;
1952
        }
1953
 
1954
        /* The super block lock path is really in the best position to
1955
         * know when resources covered by the lock need to be
1956
         * refreshed, so we do it here. Of course, making sense of
1957
         * everything is up to the caller :) */
1958
        status = ocfs2_should_refresh_lock_res(lockres);
1959
        if (status < 0) {
1960
                mlog_errno(status);
1961
                goto bail;
1962
        }
1963
        if (status) {
1964
                bh = si->si_bh;
1965
                status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0,
1966
                                          si->si_inode);
1967
                if (status == 0)
1968
                        ocfs2_update_slot_info(si);
1969
 
1970
                ocfs2_complete_lock_res_refresh(lockres, status);
1971
 
1972
                if (status < 0)
1973
                        mlog_errno(status);
1974
        }
1975
bail:
1976
        mlog_exit(status);
1977
        return status;
1978
}
1979
 
1980
void ocfs2_super_unlock(struct ocfs2_super *osb,
1981
                        int ex)
1982
{
1983
        int level = ex ? LKM_EXMODE : LKM_PRMODE;
1984
        struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
1985
 
1986
        if (!ocfs2_mount_local(osb))
1987
                ocfs2_cluster_unlock(osb, lockres, level);
1988
}
1989
 
1990
int ocfs2_rename_lock(struct ocfs2_super *osb)
1991
{
1992
        int status;
1993
        struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
1994
 
1995
        if (ocfs2_is_hard_readonly(osb))
1996
                return -EROFS;
1997
 
1998
        if (ocfs2_mount_local(osb))
1999
                return 0;
2000
 
2001
        status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0);
2002
        if (status < 0)
2003
                mlog_errno(status);
2004
 
2005
        return status;
2006
}
2007
 
2008
void ocfs2_rename_unlock(struct ocfs2_super *osb)
2009
{
2010
        struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
2011
 
2012
        if (!ocfs2_mount_local(osb))
2013
                ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE);
2014
}
2015
 
2016
int ocfs2_dentry_lock(struct dentry *dentry, int ex)
2017
{
2018
        int ret;
2019
        int level = ex ? LKM_EXMODE : LKM_PRMODE;
2020
        struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2021
        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2022
 
2023
        BUG_ON(!dl);
2024
 
2025
        if (ocfs2_is_hard_readonly(osb))
2026
                return -EROFS;
2027
 
2028
        if (ocfs2_mount_local(osb))
2029
                return 0;
2030
 
2031
        ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
2032
        if (ret < 0)
2033
                mlog_errno(ret);
2034
 
2035
        return ret;
2036
}
2037
 
2038
void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
2039
{
2040
        int level = ex ? LKM_EXMODE : LKM_PRMODE;
2041
        struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
2042
        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
2043
 
2044
        if (!ocfs2_mount_local(osb))
2045
                ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
2046
}
2047
 
2048
/* Reference counting of the dlm debug structure. We want this because
2049
 * open references on the debug inodes can live on after a mount, so
2050
 * we can't rely on the ocfs2_super to always exist. */
2051
static void ocfs2_dlm_debug_free(struct kref *kref)
2052
{
2053
        struct ocfs2_dlm_debug *dlm_debug;
2054
 
2055
        dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
2056
 
2057
        kfree(dlm_debug);
2058
}
2059
 
2060
void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
2061
{
2062
        if (dlm_debug)
2063
                kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
2064
}
2065
 
2066
static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
2067
{
2068
        kref_get(&debug->d_refcnt);
2069
}
2070
 
2071
struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
2072
{
2073
        struct ocfs2_dlm_debug *dlm_debug;
2074
 
2075
        dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
2076
        if (!dlm_debug) {
2077
                mlog_errno(-ENOMEM);
2078
                goto out;
2079
        }
2080
 
2081
        kref_init(&dlm_debug->d_refcnt);
2082
        INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
2083
        dlm_debug->d_locking_state = NULL;
2084
out:
2085
        return dlm_debug;
2086
}
2087
 
2088
/* Access to this is arbitrated for us via seq_file->sem. */
2089
struct ocfs2_dlm_seq_priv {
2090
        struct ocfs2_dlm_debug *p_dlm_debug;
2091
        struct ocfs2_lock_res p_iter_res;
2092
        struct ocfs2_lock_res p_tmp_res;
2093
};
2094
 
2095
static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
2096
                                                 struct ocfs2_dlm_seq_priv *priv)
2097
{
2098
        struct ocfs2_lock_res *iter, *ret = NULL;
2099
        struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
2100
 
2101
        assert_spin_locked(&ocfs2_dlm_tracking_lock);
2102
 
2103
        list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
2104
                /* discover the head of the list */
2105
                if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
2106
                        mlog(0, "End of list found, %p\n", ret);
2107
                        break;
2108
                }
2109
 
2110
                /* We track our "dummy" iteration lockres' by a NULL
2111
                 * l_ops field. */
2112
                if (iter->l_ops != NULL) {
2113
                        ret = iter;
2114
                        break;
2115
                }
2116
        }
2117
 
2118
        return ret;
2119
}
2120
 
2121
static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
2122
{
2123
        struct ocfs2_dlm_seq_priv *priv = m->private;
2124
        struct ocfs2_lock_res *iter;
2125
 
2126
        spin_lock(&ocfs2_dlm_tracking_lock);
2127
        iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
2128
        if (iter) {
2129
                /* Since lockres' have the lifetime of their container
2130
                 * (which can be inodes, ocfs2_supers, etc) we want to
2131
                 * copy this out to a temporary lockres while still
2132
                 * under the spinlock. Obviously after this we can't
2133
                 * trust any pointers on the copy returned, but that's
2134
                 * ok as the information we want isn't typically held
2135
                 * in them. */
2136
                priv->p_tmp_res = *iter;
2137
                iter = &priv->p_tmp_res;
2138
        }
2139
        spin_unlock(&ocfs2_dlm_tracking_lock);
2140
 
2141
        return iter;
2142
}
2143
 
2144
static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
2145
{
2146
}
2147
 
2148
static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
2149
{
2150
        struct ocfs2_dlm_seq_priv *priv = m->private;
2151
        struct ocfs2_lock_res *iter = v;
2152
        struct ocfs2_lock_res *dummy = &priv->p_iter_res;
2153
 
2154
        spin_lock(&ocfs2_dlm_tracking_lock);
2155
        iter = ocfs2_dlm_next_res(iter, priv);
2156
        list_del_init(&dummy->l_debug_list);
2157
        if (iter) {
2158
                list_add(&dummy->l_debug_list, &iter->l_debug_list);
2159
                priv->p_tmp_res = *iter;
2160
                iter = &priv->p_tmp_res;
2161
        }
2162
        spin_unlock(&ocfs2_dlm_tracking_lock);
2163
 
2164
        return iter;
2165
}
2166
 
2167
/* So that debugfs.ocfs2 can determine which format is being used */
2168
#define OCFS2_DLM_DEBUG_STR_VERSION 1
2169
static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
2170
{
2171
        int i;
2172
        char *lvb;
2173
        struct ocfs2_lock_res *lockres = v;
2174
 
2175
        if (!lockres)
2176
                return -EINVAL;
2177
 
2178
        seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
2179
 
2180
        if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
2181
                seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
2182
                           lockres->l_name,
2183
                           (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
2184
        else
2185
                seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
2186
 
2187
        seq_printf(m, "%d\t"
2188
                   "0x%lx\t"
2189
                   "0x%x\t"
2190
                   "0x%x\t"
2191
                   "%u\t"
2192
                   "%u\t"
2193
                   "%d\t"
2194
                   "%d\t",
2195
                   lockres->l_level,
2196
                   lockres->l_flags,
2197
                   lockres->l_action,
2198
                   lockres->l_unlock_action,
2199
                   lockres->l_ro_holders,
2200
                   lockres->l_ex_holders,
2201
                   lockres->l_requested,
2202
                   lockres->l_blocking);
2203
 
2204
        /* Dump the raw LVB */
2205
        lvb = lockres->l_lksb.lvb;
2206
        for(i = 0; i < DLM_LVB_LEN; i++)
2207
                seq_printf(m, "0x%x\t", lvb[i]);
2208
 
2209
        /* End the line */
2210
        seq_printf(m, "\n");
2211
        return 0;
2212
}
2213
 
2214
static struct seq_operations ocfs2_dlm_seq_ops = {
2215
        .start =        ocfs2_dlm_seq_start,
2216
        .stop =         ocfs2_dlm_seq_stop,
2217
        .next =         ocfs2_dlm_seq_next,
2218
        .show =         ocfs2_dlm_seq_show,
2219
};
2220
 
2221
static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
2222
{
2223
        struct seq_file *seq = (struct seq_file *) file->private_data;
2224
        struct ocfs2_dlm_seq_priv *priv = seq->private;
2225
        struct ocfs2_lock_res *res = &priv->p_iter_res;
2226
 
2227
        ocfs2_remove_lockres_tracking(res);
2228
        ocfs2_put_dlm_debug(priv->p_dlm_debug);
2229
        return seq_release_private(inode, file);
2230
}
2231
 
2232
static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
2233
{
2234
        int ret;
2235
        struct ocfs2_dlm_seq_priv *priv;
2236
        struct seq_file *seq;
2237
        struct ocfs2_super *osb;
2238
 
2239
        priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL);
2240
        if (!priv) {
2241
                ret = -ENOMEM;
2242
                mlog_errno(ret);
2243
                goto out;
2244
        }
2245
        osb = inode->i_private;
2246
        ocfs2_get_dlm_debug(osb->osb_dlm_debug);
2247
        priv->p_dlm_debug = osb->osb_dlm_debug;
2248
        INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
2249
 
2250
        ret = seq_open(file, &ocfs2_dlm_seq_ops);
2251
        if (ret) {
2252
                kfree(priv);
2253
                mlog_errno(ret);
2254
                goto out;
2255
        }
2256
 
2257
        seq = (struct seq_file *) file->private_data;
2258
        seq->private = priv;
2259
 
2260
        ocfs2_add_lockres_tracking(&priv->p_iter_res,
2261
                                   priv->p_dlm_debug);
2262
 
2263
out:
2264
        return ret;
2265
}
2266
 
2267
static const struct file_operations ocfs2_dlm_debug_fops = {
2268
        .open =         ocfs2_dlm_debug_open,
2269
        .release =      ocfs2_dlm_debug_release,
2270
        .read =         seq_read,
2271
        .llseek =       seq_lseek,
2272
};
2273
 
2274
static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
2275
{
2276
        int ret = 0;
2277
        struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
2278
 
2279
        dlm_debug->d_locking_state = debugfs_create_file("locking_state",
2280
                                                         S_IFREG|S_IRUSR,
2281
                                                         osb->osb_debug_root,
2282
                                                         osb,
2283
                                                         &ocfs2_dlm_debug_fops);
2284
        if (!dlm_debug->d_locking_state) {
2285
                ret = -EINVAL;
2286
                mlog(ML_ERROR,
2287
                     "Unable to create locking state debugfs file.\n");
2288
                goto out;
2289
        }
2290
 
2291
        ocfs2_get_dlm_debug(dlm_debug);
2292
out:
2293
        return ret;
2294
}
2295
 
2296
static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
2297
{
2298
        struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
2299
 
2300
        if (dlm_debug) {
2301
                debugfs_remove(dlm_debug->d_locking_state);
2302
                ocfs2_put_dlm_debug(dlm_debug);
2303
        }
2304
}
2305
 
2306
int ocfs2_dlm_init(struct ocfs2_super *osb)
2307
{
2308
        int status = 0;
2309
        u32 dlm_key;
2310
        struct dlm_ctxt *dlm = NULL;
2311
 
2312
        mlog_entry_void();
2313
 
2314
        if (ocfs2_mount_local(osb))
2315
                goto local;
2316
 
2317
        status = ocfs2_dlm_init_debug(osb);
2318
        if (status < 0) {
2319
                mlog_errno(status);
2320
                goto bail;
2321
        }
2322
 
2323
        /* launch vote thread */
2324
        osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote");
2325
        if (IS_ERR(osb->vote_task)) {
2326
                status = PTR_ERR(osb->vote_task);
2327
                osb->vote_task = NULL;
2328
                mlog_errno(status);
2329
                goto bail;
2330
        }
2331
 
2332
        /* used by the dlm code to make message headers unique, each
2333
         * node in this domain must agree on this. */
2334
        dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str));
2335
 
2336
        /* for now, uuid == domain */
2337
        dlm = dlm_register_domain(osb->uuid_str, dlm_key);
2338
        if (IS_ERR(dlm)) {
2339
                status = PTR_ERR(dlm);
2340
                mlog_errno(status);
2341
                goto bail;
2342
        }
2343
 
2344
        dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb);
2345
 
2346
local:
2347
        ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
2348
        ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
2349
 
2350
        osb->dlm = dlm;
2351
 
2352
        status = 0;
2353
bail:
2354
        if (status < 0) {
2355
                ocfs2_dlm_shutdown_debug(osb);
2356
                if (osb->vote_task)
2357
                        kthread_stop(osb->vote_task);
2358
        }
2359
 
2360
        mlog_exit(status);
2361
        return status;
2362
}
2363
 
2364
void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
2365
{
2366
        mlog_entry_void();
2367
 
2368
        dlm_unregister_eviction_cb(&osb->osb_eviction_cb);
2369
 
2370
        ocfs2_drop_osb_locks(osb);
2371
 
2372
        if (osb->vote_task) {
2373
                kthread_stop(osb->vote_task);
2374
                osb->vote_task = NULL;
2375
        }
2376
 
2377
        ocfs2_lock_res_free(&osb->osb_super_lockres);
2378
        ocfs2_lock_res_free(&osb->osb_rename_lockres);
2379
 
2380
        dlm_unregister_domain(osb->dlm);
2381
        osb->dlm = NULL;
2382
 
2383
        ocfs2_dlm_shutdown_debug(osb);
2384
 
2385
        mlog_exit_void();
2386
}
2387
 
2388
static void ocfs2_unlock_ast(void *opaque, enum dlm_status status)
2389
{
2390
        struct ocfs2_lock_res *lockres = opaque;
2391
        unsigned long flags;
2392
 
2393
        mlog_entry_void();
2394
 
2395
        mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
2396
             lockres->l_unlock_action);
2397
 
2398
        spin_lock_irqsave(&lockres->l_lock, flags);
2399
        /* We tried to cancel a convert request, but it was already
2400
         * granted. All we want to do here is clear our unlock
2401
         * state. The wake_up call done at the bottom is redundant
2402
         * (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't
2403
         * hurt anything anyway */
2404
        if (status == DLM_CANCELGRANT &&
2405
            lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
2406
                mlog(0, "Got cancelgrant for %s\n", lockres->l_name);
2407
 
2408
                /* We don't clear the busy flag in this case as it
2409
                 * should have been cleared by the ast which the dlm
2410
                 * has called. */
2411
                goto complete_unlock;
2412
        }
2413
 
2414
        if (status != DLM_NORMAL) {
2415
                mlog(ML_ERROR, "Dlm passes status %d for lock %s, "
2416
                     "unlock_action %d\n", status, lockres->l_name,
2417
                     lockres->l_unlock_action);
2418
                spin_unlock_irqrestore(&lockres->l_lock, flags);
2419
                return;
2420
        }
2421
 
2422
        switch(lockres->l_unlock_action) {
2423
        case OCFS2_UNLOCK_CANCEL_CONVERT:
2424
                mlog(0, "Cancel convert success for %s\n", lockres->l_name);
2425
                lockres->l_action = OCFS2_AST_INVALID;
2426
                break;
2427
        case OCFS2_UNLOCK_DROP_LOCK:
2428
                lockres->l_level = LKM_IVMODE;
2429
                break;
2430
        default:
2431
                BUG();
2432
        }
2433
 
2434
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
2435
complete_unlock:
2436
        lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
2437
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2438
 
2439
        wake_up(&lockres->l_event);
2440
 
2441
        mlog_exit_void();
2442
}
2443
 
2444
static int ocfs2_drop_lock(struct ocfs2_super *osb,
2445
                           struct ocfs2_lock_res *lockres)
2446
{
2447
        enum dlm_status status;
2448
        unsigned long flags;
2449
        int lkm_flags = 0;
2450
 
2451
        /* We didn't get anywhere near actually using this lockres. */
2452
        if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
2453
                goto out;
2454
 
2455
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
2456
                lkm_flags |= LKM_VALBLK;
2457
 
2458
        spin_lock_irqsave(&lockres->l_lock, flags);
2459
 
2460
        mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
2461
                        "lockres %s, flags 0x%lx\n",
2462
                        lockres->l_name, lockres->l_flags);
2463
 
2464
        while (lockres->l_flags & OCFS2_LOCK_BUSY) {
2465
                mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
2466
                     "%u, unlock_action = %u\n",
2467
                     lockres->l_name, lockres->l_flags, lockres->l_action,
2468
                     lockres->l_unlock_action);
2469
 
2470
                spin_unlock_irqrestore(&lockres->l_lock, flags);
2471
 
2472
                /* XXX: Today we just wait on any busy
2473
                 * locks... Perhaps we need to cancel converts in the
2474
                 * future? */
2475
                ocfs2_wait_on_busy_lock(lockres);
2476
 
2477
                spin_lock_irqsave(&lockres->l_lock, flags);
2478
        }
2479
 
2480
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
2481
                if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
2482
                    lockres->l_level == LKM_EXMODE &&
2483
                    !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
2484
                        lockres->l_ops->set_lvb(lockres);
2485
        }
2486
 
2487
        if (lockres->l_flags & OCFS2_LOCK_BUSY)
2488
                mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
2489
                     lockres->l_name);
2490
        if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
2491
                mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
2492
 
2493
        if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
2494
                spin_unlock_irqrestore(&lockres->l_lock, flags);
2495
                goto out;
2496
        }
2497
 
2498
        lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
2499
 
2500
        /* make sure we never get here while waiting for an ast to
2501
         * fire. */
2502
        BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
2503
 
2504
        /* is this necessary? */
2505
        lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2506
        lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
2507
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2508
 
2509
        mlog(0, "lock %s\n", lockres->l_name);
2510
 
2511
        status = dlmunlock(osb->dlm, &lockres->l_lksb, lkm_flags,
2512
                           ocfs2_unlock_ast, lockres);
2513
        if (status != DLM_NORMAL) {
2514
                ocfs2_log_dlm_error("dlmunlock", status, lockres);
2515
                mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
2516
                dlm_print_one_lock(lockres->l_lksb.lockid);
2517
                BUG();
2518
        }
2519
        mlog(0, "lock %s, successfull return from dlmunlock\n",
2520
             lockres->l_name);
2521
 
2522
        ocfs2_wait_on_busy_lock(lockres);
2523
out:
2524
        mlog_exit(0);
2525
        return 0;
2526
}
2527
 
2528
/* Mark the lockres as being dropped. It will no longer be
2529
 * queued if blocking, but we still may have to wait on it
2530
 * being dequeued from the vote thread before we can consider
2531
 * it safe to drop.
2532
 *
2533
 * You can *not* attempt to call cluster_lock on this lockres anymore. */
2534
void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres)
2535
{
2536
        int status;
2537
        struct ocfs2_mask_waiter mw;
2538
        unsigned long flags;
2539
 
2540
        ocfs2_init_mask_waiter(&mw);
2541
 
2542
        spin_lock_irqsave(&lockres->l_lock, flags);
2543
        lockres->l_flags |= OCFS2_LOCK_FREEING;
2544
        while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
2545
                lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
2546
                spin_unlock_irqrestore(&lockres->l_lock, flags);
2547
 
2548
                mlog(0, "Waiting on lockres %s\n", lockres->l_name);
2549
 
2550
                status = ocfs2_wait_for_mask(&mw);
2551
                if (status)
2552
                        mlog_errno(status);
2553
 
2554
                spin_lock_irqsave(&lockres->l_lock, flags);
2555
        }
2556
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2557
}
2558
 
2559
void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
2560
                               struct ocfs2_lock_res *lockres)
2561
{
2562
        int ret;
2563
 
2564
        ocfs2_mark_lockres_freeing(lockres);
2565
        ret = ocfs2_drop_lock(osb, lockres);
2566
        if (ret)
2567
                mlog_errno(ret);
2568
}
2569
 
2570
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
2571
{
2572
        ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
2573
        ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
2574
}
2575
 
2576
int ocfs2_drop_inode_locks(struct inode *inode)
2577
{
2578
        int status, err;
2579
 
2580
        mlog_entry_void();
2581
 
2582
        /* No need to call ocfs2_mark_lockres_freeing here -
2583
         * ocfs2_clear_inode has done it for us. */
2584
 
2585
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
2586
                              &OCFS2_I(inode)->ip_open_lockres);
2587
        if (err < 0)
2588
                mlog_errno(err);
2589
 
2590
        status = err;
2591
 
2592
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
2593
                              &OCFS2_I(inode)->ip_data_lockres);
2594
        if (err < 0)
2595
                mlog_errno(err);
2596
        if (err < 0 && !status)
2597
                status = err;
2598
 
2599
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
2600
                              &OCFS2_I(inode)->ip_meta_lockres);
2601
        if (err < 0)
2602
                mlog_errno(err);
2603
        if (err < 0 && !status)
2604
                status = err;
2605
 
2606
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
2607
                              &OCFS2_I(inode)->ip_rw_lockres);
2608
        if (err < 0)
2609
                mlog_errno(err);
2610
        if (err < 0 && !status)
2611
                status = err;
2612
 
2613
        mlog_exit(status);
2614
        return status;
2615
}
2616
 
2617
static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
2618
                                      int new_level)
2619
{
2620
        assert_spin_locked(&lockres->l_lock);
2621
 
2622
        BUG_ON(lockres->l_blocking <= LKM_NLMODE);
2623
 
2624
        if (lockres->l_level <= new_level) {
2625
                mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n",
2626
                     lockres->l_level, new_level);
2627
                BUG();
2628
        }
2629
 
2630
        mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
2631
             lockres->l_name, new_level, lockres->l_blocking);
2632
 
2633
        lockres->l_action = OCFS2_AST_DOWNCONVERT;
2634
        lockres->l_requested = new_level;
2635
        lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
2636
}
2637
 
2638
static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
2639
                                  struct ocfs2_lock_res *lockres,
2640
                                  int new_level,
2641
                                  int lvb)
2642
{
2643
        int ret, dlm_flags = LKM_CONVERT;
2644
        enum dlm_status status;
2645
 
2646
        mlog_entry_void();
2647
 
2648
        if (lvb)
2649
                dlm_flags |= LKM_VALBLK;
2650
 
2651
        status = dlmlock(osb->dlm,
2652
                         new_level,
2653
                         &lockres->l_lksb,
2654
                         dlm_flags,
2655
                         lockres->l_name,
2656
                         OCFS2_LOCK_ID_MAX_LEN - 1,
2657
                         ocfs2_locking_ast,
2658
                         lockres,
2659
                         ocfs2_blocking_ast);
2660
        if (status != DLM_NORMAL) {
2661
                ocfs2_log_dlm_error("dlmlock", status, lockres);
2662
                ret = -EINVAL;
2663
                ocfs2_recover_from_dlm_error(lockres, 1);
2664
                goto bail;
2665
        }
2666
 
2667
        ret = 0;
2668
bail:
2669
        mlog_exit(ret);
2670
        return ret;
2671
}
2672
 
2673
/* returns 1 when the caller should unlock and call dlmunlock */
2674
static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
2675
                                        struct ocfs2_lock_res *lockres)
2676
{
2677
        assert_spin_locked(&lockres->l_lock);
2678
 
2679
        mlog_entry_void();
2680
        mlog(0, "lock %s\n", lockres->l_name);
2681
 
2682
        if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
2683
                /* If we're already trying to cancel a lock conversion
2684
                 * then just drop the spinlock and allow the caller to
2685
                 * requeue this lock. */
2686
 
2687
                mlog(0, "Lockres %s, skip convert\n", lockres->l_name);
2688
                return 0;
2689
        }
2690
 
2691
        /* were we in a convert when we got the bast fire? */
2692
        BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
2693
               lockres->l_action != OCFS2_AST_DOWNCONVERT);
2694
        /* set things up for the unlockast to know to just
2695
         * clear out the ast_action and unset busy, etc. */
2696
        lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
2697
 
2698
        mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
2699
                        "lock %s, invalid flags: 0x%lx\n",
2700
                        lockres->l_name, lockres->l_flags);
2701
 
2702
        return 1;
2703
}
2704
 
2705
static int ocfs2_cancel_convert(struct ocfs2_super *osb,
2706
                                struct ocfs2_lock_res *lockres)
2707
{
2708
        int ret;
2709
        enum dlm_status status;
2710
 
2711
        mlog_entry_void();
2712
        mlog(0, "lock %s\n", lockres->l_name);
2713
 
2714
        ret = 0;
2715
        status = dlmunlock(osb->dlm,
2716
                           &lockres->l_lksb,
2717
                           LKM_CANCEL,
2718
                           ocfs2_unlock_ast,
2719
                           lockres);
2720
        if (status != DLM_NORMAL) {
2721
                ocfs2_log_dlm_error("dlmunlock", status, lockres);
2722
                ret = -EINVAL;
2723
                ocfs2_recover_from_dlm_error(lockres, 0);
2724
        }
2725
 
2726
        mlog(0, "lock %s return from dlmunlock\n", lockres->l_name);
2727
 
2728
        mlog_exit(ret);
2729
        return ret;
2730
}
2731
 
2732
static int ocfs2_unblock_lock(struct ocfs2_super *osb,
2733
                              struct ocfs2_lock_res *lockres,
2734
                              struct ocfs2_unblock_ctl *ctl)
2735
{
2736
        unsigned long flags;
2737
        int blocking;
2738
        int new_level;
2739
        int ret = 0;
2740
        int set_lvb = 0;
2741
 
2742
        mlog_entry_void();
2743
 
2744
        spin_lock_irqsave(&lockres->l_lock, flags);
2745
 
2746
        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
2747
 
2748
recheck:
2749
        if (lockres->l_flags & OCFS2_LOCK_BUSY) {
2750
                ctl->requeue = 1;
2751
                ret = ocfs2_prepare_cancel_convert(osb, lockres);
2752
                spin_unlock_irqrestore(&lockres->l_lock, flags);
2753
                if (ret) {
2754
                        ret = ocfs2_cancel_convert(osb, lockres);
2755
                        if (ret < 0)
2756
                                mlog_errno(ret);
2757
                }
2758
                goto leave;
2759
        }
2760
 
2761
        /* if we're blocking an exclusive and we have *any* holders,
2762
         * then requeue. */
2763
        if ((lockres->l_blocking == LKM_EXMODE)
2764
            && (lockres->l_ex_holders || lockres->l_ro_holders))
2765
                goto leave_requeue;
2766
 
2767
        /* If it's a PR we're blocking, then only
2768
         * requeue if we've got any EX holders */
2769
        if (lockres->l_blocking == LKM_PRMODE &&
2770
            lockres->l_ex_holders)
2771
                goto leave_requeue;
2772
 
2773
        /*
2774
         * Can we get a lock in this state if the holder counts are
2775
         * zero? The meta data unblock code used to check this.
2776
         */
2777
        if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
2778
            && (lockres->l_flags & OCFS2_LOCK_REFRESHING))
2779
                goto leave_requeue;
2780
 
2781
        new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
2782
 
2783
        if (lockres->l_ops->check_downconvert
2784
            && !lockres->l_ops->check_downconvert(lockres, new_level))
2785
                goto leave_requeue;
2786
 
2787
        /* If we get here, then we know that there are no more
2788
         * incompatible holders (and anyone asking for an incompatible
2789
         * lock is blocked). We can now downconvert the lock */
2790
        if (!lockres->l_ops->downconvert_worker)
2791
                goto downconvert;
2792
 
2793
        /* Some lockres types want to do a bit of work before
2794
         * downconverting a lock. Allow that here. The worker function
2795
         * may sleep, so we save off a copy of what we're blocking as
2796
         * it may change while we're not holding the spin lock. */
2797
        blocking = lockres->l_blocking;
2798
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2799
 
2800
        ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
2801
 
2802
        if (ctl->unblock_action == UNBLOCK_STOP_POST)
2803
                goto leave;
2804
 
2805
        spin_lock_irqsave(&lockres->l_lock, flags);
2806
        if (blocking != lockres->l_blocking) {
2807
                /* If this changed underneath us, then we can't drop
2808
                 * it just yet. */
2809
                goto recheck;
2810
        }
2811
 
2812
downconvert:
2813
        ctl->requeue = 0;
2814
 
2815
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
2816
                if (lockres->l_level == LKM_EXMODE)
2817
                        set_lvb = 1;
2818
 
2819
                /*
2820
                 * We only set the lvb if the lock has been fully
2821
                 * refreshed - otherwise we risk setting stale
2822
                 * data. Otherwise, there's no need to actually clear
2823
                 * out the lvb here as it's value is still valid.
2824
                 */
2825
                if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
2826
                        lockres->l_ops->set_lvb(lockres);
2827
        }
2828
 
2829
        ocfs2_prepare_downconvert(lockres, new_level);
2830
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2831
        ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
2832
leave:
2833
        mlog_exit(ret);
2834
        return ret;
2835
 
2836
leave_requeue:
2837
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2838
        ctl->requeue = 1;
2839
 
2840
        mlog_exit(0);
2841
        return 0;
2842
}
2843
 
2844
static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
2845
                                     int blocking)
2846
{
2847
        struct inode *inode;
2848
        struct address_space *mapping;
2849
 
2850
        inode = ocfs2_lock_res_inode(lockres);
2851
        mapping = inode->i_mapping;
2852
 
2853
        /*
2854
         * We need this before the filemap_fdatawrite() so that it can
2855
         * transfer the dirty bit from the PTE to the
2856
         * page. Unfortunately this means that even for EX->PR
2857
         * downconverts, we'll lose our mappings and have to build
2858
         * them up again.
2859
         */
2860
        unmap_mapping_range(mapping, 0, 0, 0);
2861
 
2862
        if (filemap_fdatawrite(mapping)) {
2863
                mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
2864
                     (unsigned long long)OCFS2_I(inode)->ip_blkno);
2865
        }
2866
        sync_mapping_buffers(mapping);
2867
        if (blocking == LKM_EXMODE) {
2868
                truncate_inode_pages(mapping, 0);
2869
        } else {
2870
                /* We only need to wait on the I/O if we're not also
2871
                 * truncating pages because truncate_inode_pages waits
2872
                 * for us above. We don't truncate pages if we're
2873
                 * blocking anything < EXMODE because we want to keep
2874
                 * them around in that case. */
2875
                filemap_fdatawait(mapping);
2876
        }
2877
 
2878
        return UNBLOCK_CONTINUE;
2879
}
2880
 
2881
static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
2882
                                        int new_level)
2883
{
2884
        struct inode *inode = ocfs2_lock_res_inode(lockres);
2885
        int checkpointed = ocfs2_inode_fully_checkpointed(inode);
2886
 
2887
        BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
2888
        BUG_ON(lockres->l_level != LKM_EXMODE && !checkpointed);
2889
 
2890
        if (checkpointed)
2891
                return 1;
2892
 
2893
        ocfs2_start_checkpoint(OCFS2_SB(inode->i_sb));
2894
        return 0;
2895
}
2896
 
2897
static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
2898
{
2899
        struct inode *inode = ocfs2_lock_res_inode(lockres);
2900
 
2901
        __ocfs2_stuff_meta_lvb(inode);
2902
}
2903
 
2904
/*
2905
 * Does the final reference drop on our dentry lock. Right now this
2906
 * happens in the vote thread, but we could choose to simplify the
2907
 * dlmglue API and push these off to the ocfs2_wq in the future.
2908
 */
2909
static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
2910
                                     struct ocfs2_lock_res *lockres)
2911
{
2912
        struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
2913
        ocfs2_dentry_lock_put(osb, dl);
2914
}
2915
 
2916
/*
2917
 * d_delete() matching dentries before the lock downconvert.
2918
 *
2919
 * At this point, any process waiting to destroy the
2920
 * dentry_lock due to last ref count is stopped by the
2921
 * OCFS2_LOCK_QUEUED flag.
2922
 *
2923
 * We have two potential problems
2924
 *
2925
 * 1) If we do the last reference drop on our dentry_lock (via dput)
2926
 *    we'll wind up in ocfs2_release_dentry_lock(), waiting on
2927
 *    the downconvert to finish. Instead we take an elevated
2928
 *    reference and push the drop until after we've completed our
2929
 *    unblock processing.
2930
 *
2931
 * 2) There might be another process with a final reference,
2932
 *    waiting on us to finish processing. If this is the case, we
2933
 *    detect it and exit out - there's no more dentries anyway.
2934
 */
2935
static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
2936
                                       int blocking)
2937
{
2938
        struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
2939
        struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
2940
        struct dentry *dentry;
2941
        unsigned long flags;
2942
        int extra_ref = 0;
2943
 
2944
        /*
2945
         * This node is blocking another node from getting a read
2946
         * lock. This happens when we've renamed within a
2947
         * directory. We've forced the other nodes to d_delete(), but
2948
         * we never actually dropped our lock because it's still
2949
         * valid. The downconvert code will retain a PR for this node,
2950
         * so there's no further work to do.
2951
         */
2952
        if (blocking == LKM_PRMODE)
2953
                return UNBLOCK_CONTINUE;
2954
 
2955
        /*
2956
         * Mark this inode as potentially orphaned. The code in
2957
         * ocfs2_delete_inode() will figure out whether it actually
2958
         * needs to be freed or not.
2959
         */
2960
        spin_lock(&oi->ip_lock);
2961
        oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
2962
        spin_unlock(&oi->ip_lock);
2963
 
2964
        /*
2965
         * Yuck. We need to make sure however that the check of
2966
         * OCFS2_LOCK_FREEING and the extra reference are atomic with
2967
         * respect to a reference decrement or the setting of that
2968
         * flag.
2969
         */
2970
        spin_lock_irqsave(&lockres->l_lock, flags);
2971
        spin_lock(&dentry_attach_lock);
2972
        if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
2973
            && dl->dl_count) {
2974
                dl->dl_count++;
2975
                extra_ref = 1;
2976
        }
2977
        spin_unlock(&dentry_attach_lock);
2978
        spin_unlock_irqrestore(&lockres->l_lock, flags);
2979
 
2980
        mlog(0, "extra_ref = %d\n", extra_ref);
2981
 
2982
        /*
2983
         * We have a process waiting on us in ocfs2_dentry_iput(),
2984
         * which means we can't have any more outstanding
2985
         * aliases. There's no need to do any more work.
2986
         */
2987
        if (!extra_ref)
2988
                return UNBLOCK_CONTINUE;
2989
 
2990
        spin_lock(&dentry_attach_lock);
2991
        while (1) {
2992
                dentry = ocfs2_find_local_alias(dl->dl_inode,
2993
                                                dl->dl_parent_blkno, 1);
2994
                if (!dentry)
2995
                        break;
2996
                spin_unlock(&dentry_attach_lock);
2997
 
2998
                mlog(0, "d_delete(%.*s);\n", dentry->d_name.len,
2999
                     dentry->d_name.name);
3000
 
3001
                /*
3002
                 * The following dcache calls may do an
3003
                 * iput(). Normally we don't want that from the
3004
                 * downconverting thread, but in this case it's ok
3005
                 * because the requesting node already has an
3006
                 * exclusive lock on the inode, so it can't be queued
3007
                 * for a downconvert.
3008
                 */
3009
                d_delete(dentry);
3010
                dput(dentry);
3011
 
3012
                spin_lock(&dentry_attach_lock);
3013
        }
3014
        spin_unlock(&dentry_attach_lock);
3015
 
3016
        /*
3017
         * If we are the last holder of this dentry lock, there is no
3018
         * reason to downconvert so skip straight to the unlock.
3019
         */
3020
        if (dl->dl_count == 1)
3021
                return UNBLOCK_STOP_POST;
3022
 
3023
        return UNBLOCK_CONTINUE_POST;
3024
}
3025
 
3026
void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
3027
                                struct ocfs2_lock_res *lockres)
3028
{
3029
        int status;
3030
        struct ocfs2_unblock_ctl ctl = {0, 0,};
3031
        unsigned long flags;
3032
 
3033
        /* Our reference to the lockres in this function can be
3034
         * considered valid until we remove the OCFS2_LOCK_QUEUED
3035
         * flag. */
3036
 
3037
        mlog_entry_void();
3038
 
3039
        BUG_ON(!lockres);
3040
        BUG_ON(!lockres->l_ops);
3041
 
3042
        mlog(0, "lockres %s blocked.\n", lockres->l_name);
3043
 
3044
        /* Detect whether a lock has been marked as going away while
3045
         * the vote thread was processing other things. A lock can
3046
         * still be marked with OCFS2_LOCK_FREEING after this check,
3047
         * but short circuiting here will still save us some
3048
         * performance. */
3049
        spin_lock_irqsave(&lockres->l_lock, flags);
3050
        if (lockres->l_flags & OCFS2_LOCK_FREEING)
3051
                goto unqueue;
3052
        spin_unlock_irqrestore(&lockres->l_lock, flags);
3053
 
3054
        status = ocfs2_unblock_lock(osb, lockres, &ctl);
3055
        if (status < 0)
3056
                mlog_errno(status);
3057
 
3058
        spin_lock_irqsave(&lockres->l_lock, flags);
3059
unqueue:
3060
        if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
3061
                lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
3062
        } else
3063
                ocfs2_schedule_blocked_lock(osb, lockres);
3064
 
3065
        mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
3066
             ctl.requeue ? "yes" : "no");
3067
        spin_unlock_irqrestore(&lockres->l_lock, flags);
3068
 
3069
        if (ctl.unblock_action != UNBLOCK_CONTINUE
3070
            && lockres->l_ops->post_unlock)
3071
                lockres->l_ops->post_unlock(osb, lockres);
3072
 
3073
        mlog_exit_void();
3074
}
3075
 
3076
static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
3077
                                        struct ocfs2_lock_res *lockres)
3078
{
3079
        mlog_entry_void();
3080
 
3081
        assert_spin_locked(&lockres->l_lock);
3082
 
3083
        if (lockres->l_flags & OCFS2_LOCK_FREEING) {
3084
                /* Do not schedule a lock for downconvert when it's on
3085
                 * the way to destruction - any nodes wanting access
3086
                 * to the resource will get it soon. */
3087
                mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n",
3088
                     lockres->l_name, lockres->l_flags);
3089
                return;
3090
        }
3091
 
3092
        lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
3093
 
3094
        spin_lock(&osb->vote_task_lock);
3095
        if (list_empty(&lockres->l_blocked_list)) {
3096
                list_add_tail(&lockres->l_blocked_list,
3097
                              &osb->blocked_lock_list);
3098
                osb->blocked_lock_count++;
3099
        }
3100
        spin_unlock(&osb->vote_task_lock);
3101
 
3102
        mlog_exit_void();
3103
}

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