summaryrefslogtreecommitdiffstats
path: root/xlators/features/bit-rot/src/stub/bit-rot-stub-helpers.c
blob: 8ac13a09941897223306be3cda22a5eb7e5b0707 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
/*
   Copyright (c) 2015 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/

#include "bit-rot-stub.h"

br_stub_fd_t *
br_stub_fd_new(void)
{
    br_stub_fd_t *br_stub_fd = NULL;

    br_stub_fd = GF_CALLOC(1, sizeof(*br_stub_fd), gf_br_stub_mt_br_stub_fd_t);

    return br_stub_fd;
}

int
__br_stub_fd_ctx_set(xlator_t *this, fd_t *fd, br_stub_fd_t *br_stub_fd)
{
    uint64_t value = 0;
    int ret = -1;

    GF_VALIDATE_OR_GOTO("bit-rot-stub", this, out);
    GF_VALIDATE_OR_GOTO(this->name, fd, out);
    GF_VALIDATE_OR_GOTO(this->name, br_stub_fd, out);

    value = (uint64_t)(long)br_stub_fd;

    ret = __fd_ctx_set(fd, this, value);

out:
    return ret;
}

br_stub_fd_t *
__br_stub_fd_ctx_get(xlator_t *this, fd_t *fd)
{
    br_stub_fd_t *br_stub_fd = NULL;
    uint64_t value = 0;
    int ret = -1;

    GF_VALIDATE_OR_GOTO("bit-rot-stub", this, out);
    GF_VALIDATE_OR_GOTO(this->name, fd, out);

    ret = __fd_ctx_get(fd, this, &value);
    if (ret)
        return NULL;

    br_stub_fd = (br_stub_fd_t *)((long)value);

out:
    return br_stub_fd;
}

br_stub_fd_t *
br_stub_fd_ctx_get(xlator_t *this, fd_t *fd)
{
    br_stub_fd_t *br_stub_fd = NULL;

    GF_VALIDATE_OR_GOTO("bit-rot-stub", this, out);
    GF_VALIDATE_OR_GOTO(this->name, fd, out);

    LOCK(&fd->lock);
    {
        br_stub_fd = __br_stub_fd_ctx_get(this, fd);
    }
    UNLOCK(&fd->lock);

out:
    return br_stub_fd;
}

int32_t
br_stub_fd_ctx_set(xlator_t *this, fd_t *fd, br_stub_fd_t *br_stub_fd)
{
    int32_t ret = -1;

    GF_VALIDATE_OR_GOTO("bit-rot-stub", this, out);
    GF_VALIDATE_OR_GOTO(this->name, fd, out);
    GF_VALIDATE_OR_GOTO(this->name, br_stub_fd, out);

    LOCK(&fd->lock);
    {
        ret = __br_stub_fd_ctx_set(this, fd, br_stub_fd);
    }
    UNLOCK(&fd->lock);

out:
    return ret;
}

/**
 * Adds an entry to the bad objects directory.
 * @gfid: gfid of the bad object being added to the bad objects directory
 */
int
br_stub_add(xlator_t *this, uuid_t gfid)
{
    char gfid_path[BR_PATH_MAX_PLUS] = {0};
    char bad_gfid_path[BR_PATH_MAX_PLUS] = {0};
    int ret = 0;
    br_stub_private_t *priv = NULL;
    struct stat st = {0};

    priv = this->private;
    GF_ASSERT_AND_GOTO_WITH_ERROR(this->name, !gf_uuid_is_null(gfid), out,
                                  errno, EINVAL);

    snprintf(gfid_path, sizeof(gfid_path), "%s/%s", priv->stub_basepath,
             uuid_utoa(gfid));

    ret = sys_stat(gfid_path, &st);
    if (!ret)
        goto out;
    snprintf(bad_gfid_path, sizeof(bad_gfid_path), "%s/stub-%s",
             priv->stub_basepath, uuid_utoa(priv->bad_object_dir_gfid));

    ret = sys_link(bad_gfid_path, gfid_path);
    if (ret) {
        if ((errno != ENOENT) && (errno != EMLINK) && (errno != EEXIST))
            goto out;

        /*
         * Continue with success. At least we'll have half of the
         * functionality, in the sense, object is marked bad and
         * would be inaccessible. It's only scrub status that would
         * show up less number of objects. That's fine as we'll have
         * the log files that will have the missing information.
         */
        gf_smsg(this->name, GF_LOG_WARNING, errno, BRS_MSG_LINK_FAIL, "gfid=%s",
                uuid_utoa(gfid), NULL);
    }

    return 0;
out:
    return -1;
}

int
br_stub_del(xlator_t *this, uuid_t gfid)
{
    int32_t op_errno __attribute__((unused)) = 0;
    br_stub_private_t *priv = NULL;
    int ret = 0;
    char gfid_path[BR_PATH_MAX_PLUS] = {0};

    priv = this->private;
    GF_ASSERT_AND_GOTO_WITH_ERROR(this->name, !gf_uuid_is_null(gfid), out,
                                  op_errno, EINVAL);
    snprintf(gfid_path, sizeof(gfid_path), "%s/%s", priv->stub_basepath,
             uuid_utoa(gfid));
    ret = sys_unlink(gfid_path);
    if (ret && (errno != ENOENT)) {
        gf_smsg(this->name, GF_LOG_ERROR, errno, BRS_MSG_BAD_OBJ_UNLINK_FAIL,
                "path=%s", gfid_path, NULL);
        ret = -errno;
        goto out;
    }

    ret = 0;

out:
    return ret;
}

static int
br_stub_check_stub_directory(xlator_t *this, char *fullpath)
{
    int ret = 0;
    struct stat st = {
        0,
    };
    char oldpath[BR_PATH_MAX_PLUS] = {0};
    br_stub_private_t *priv = NULL;

    priv = this->private;

    snprintf(oldpath, sizeof(oldpath), "%s/%s", priv->export,
             OLD_BR_STUB_QUARANTINE_DIR);

    ret = sys_stat(fullpath, &st);
    if (!ret && !S_ISDIR(st.st_mode))
        goto error_return;
    if (ret) {
        if (errno != ENOENT)
            goto error_return;
        ret = sys_stat(oldpath, &st);
        if (ret)
            ret = mkdir_p(fullpath, 0600, _gf_true);
        else
            ret = sys_rename(oldpath, fullpath);
    }

    if (ret)
        gf_smsg(this->name, GF_LOG_ERROR, errno, BRS_MSG_BAD_OBJECT_DIR_FAIL,
                "create-path=%s", fullpath, NULL);
    return ret;

error_return:
    gf_smsg(this->name, GF_LOG_ERROR, errno, BRS_MSG_BAD_OBJECT_DIR_FAIL,
            "verify-path=%s", fullpath, NULL);
    return -1;
}

/**
 * Function to create the container for the bad objects within the bad objects
 * directory.
 */
static int
br_stub_check_stub_file(xlator_t *this, char *path)
{
    int ret = 0;
    int fd = -1;
    struct stat st = {
        0,
    };

    ret = sys_stat(path, &st);
    if (!ret && !S_ISREG(st.st_mode))
        goto error_return;
    if (ret) {
        if (errno != ENOENT)
            goto error_return;
        fd = sys_creat(path, 0);
        if (fd < 0)
            gf_smsg(this->name, GF_LOG_ERROR, errno,
                    BRS_MSG_BAD_OBJECT_DIR_FAIL, "create-path=%s", path, NULL);
    }

    if (fd >= 0) {
        sys_close(fd);
        ret = 0;
    }

    return ret;

error_return:
    gf_smsg(this->name, GF_LOG_ERROR, errno, BRS_MSG_BAD_OBJECT_DIR_FAIL,
            "verify-path=%s", path, NULL);
    return -1;
}

int
br_stub_dir_create(xlator_t *this, br_stub_private_t *priv)
{
    int ret = -1;
    char fullpath[BR_PATH_MAX_PLUS] = {
        0,
    };
    char stub_gfid_path[BR_PATH_MAX_PLUS] = {
        0,
    };

    gf_uuid_copy(priv->bad_object_dir_gfid, BR_BAD_OBJ_CONTAINER);

    if (snprintf(fullpath, sizeof(fullpath), "%s", priv->stub_basepath) >=
        sizeof(fullpath))
        goto out;

    if (snprintf(stub_gfid_path, sizeof(stub_gfid_path), "%s/stub-%s",
                 priv->stub_basepath, uuid_utoa(priv->bad_object_dir_gfid)) >=
        sizeof(stub_gfid_path))
        goto out;

    ret = br_stub_check_stub_directory(this, fullpath);
    if (ret)
        goto out;
    ret = br_stub_check_stub_file(this, stub_gfid_path);
    if (ret)
        goto out;

    return 0;

out:
    return -1;
}

call_stub_t *
__br_stub_dequeue(struct list_head *callstubs)
{
    call_stub_t *stub = NULL;

    if (!list_empty(callstubs)) {
        stub = list_entry(callstubs->next, call_stub_t, list);
        list_del_init(&stub->list);
    }

    return stub;
}

void
__br_stub_enqueue(struct list_head *callstubs, call_stub_t *stub)
{
    list_add_tail(&stub->list, callstubs);
}

void
br_stub_worker_enqueue(xlator_t *this, call_stub_t *stub)
{
    br_stub_private_t *priv = NULL;

    priv = this->private;
    pthread_mutex_lock(&priv->container.bad_lock);
    {
        __br_stub_enqueue(&priv->container.bad_queue, stub);
        pthread_cond_signal(&priv->container.bad_cond);
    }
    pthread_mutex_unlock(&priv->container.bad_lock);
}

void *
br_stub_worker(void *data)
{
    br_stub_private_t *priv = NULL;
    xlator_t *this = NULL;
    call_stub_t *stub = NULL;

    THIS = data;
    this = data;
    priv = this->private;

    for (;;) {
        pthread_mutex_lock(&priv->container.bad_lock);
        {
            while (list_empty(&priv->container.bad_queue)) {
                (void)pthread_cond_wait(&priv->container.bad_cond,
                                        &priv->container.bad_lock);
            }

            stub = __br_stub_dequeue(&priv->container.bad_queue);
        }
        pthread_mutex_unlock(&priv->container.bad_lock);

        if (stub) /* guard against spurious wakeups */
            call_resume(stub);
    }

    return NULL;
}

int32_t
br_stub_lookup_wrapper(call_frame_t *frame, xlator_t *this, loc_t *loc,
                       dict_t *xattr_req)
{
    br_stub_private_t *priv = NULL;
    struct stat lstatbuf = {0};
    int ret = 0;
    int32_t op_errno = EINVAL;
    int32_t op_ret = -1;
    struct iatt stbuf = {
        0,
    };
    struct iatt postparent = {
        0,
    };
    dict_t *xattr = NULL;
    gf_boolean_t ver_enabled = _gf_false;

    BR_STUB_VER_ENABLED_IN_CALLPATH(frame, ver_enabled);
    priv = this->private;
    BR_STUB_VER_COND_GOTO(priv, (!ver_enabled), done);

    VALIDATE_OR_GOTO(loc, done);
    if (gf_uuid_compare(loc->gfid, priv->bad_object_dir_gfid))
        goto done;

    ret = sys_lstat(priv->stub_basepath, &lstatbuf);
    if (ret) {
        gf_msg_debug(this->name, errno,
                     "Stat failed on stub bad "
                     "object dir");
        op_errno = errno;
        goto done;
    } else if (!S_ISDIR(lstatbuf.st_mode)) {
        gf_msg_debug(this->name, errno,
                     "bad object container is not "
                     "a directory");
        op_errno = ENOTDIR;
        goto done;
    }

    iatt_from_stat(&stbuf, &lstatbuf);
    gf_uuid_copy(stbuf.ia_gfid, priv->bad_object_dir_gfid);

    op_ret = op_errno = 0;
    xattr = dict_new();
    if (!xattr) {
        op_ret = -1;
        op_errno = ENOMEM;
    }

done:
    STACK_UNWIND_STRICT(lookup, frame, op_ret, op_errno, loc->inode, &stbuf,
                        xattr, &postparent);
    if (xattr)
        dict_unref(xattr);
    return 0;
}

static int
is_bad_gfid_file_current(char *filename, uuid_t gfid)
{
    char current_stub_gfid[GF_UUID_BUF_SIZE + 16] = {
        0,
    };

    snprintf(current_stub_gfid, sizeof current_stub_gfid, "stub-%s",
             uuid_utoa(gfid));
    return (!strcmp(filename, current_stub_gfid));
}

static void
check_delete_stale_bad_file(xlator_t *this, char *filename)
{
    int ret = 0;
    struct stat st = {0};
    char filepath[BR_PATH_MAX_PLUS] = {0};
    br_stub_private_t *priv = NULL;

    priv = this->private;

    if (is_bad_gfid_file_current(filename, priv->bad_object_dir_gfid))
        return;

    snprintf(filepath, sizeof(filepath), "%s/%s", priv->stub_basepath,
             filename);

    ret = sys_stat(filepath, &st);
    if (!ret && st.st_nlink == 1)
        sys_unlink(filepath);
}

static int
br_stub_fill_readdir(fd_t *fd, br_stub_fd_t *fctx, DIR *dir, off_t off,
                     size_t size, gf_dirent_t *entries)
{
    off_t in_case = -1;
    off_t last_off = 0;
    size_t filled = 0;
    int count = 0;
    int32_t this_size = -1;
    gf_dirent_t *this_entry = NULL;
    xlator_t *this = NULL;
    struct dirent *entry = NULL;
    struct dirent scratch[2] = {
        {
            0,
        },
    };

    this = THIS;
    if (!off) {
        rewinddir(dir);
    } else {
        seekdir(dir, off);
#ifndef GF_LINUX_HOST_OS
        if ((u_long)telldir(dir) != off && off != fctx->bad_object.dir_eof) {
            gf_smsg(THIS->name, GF_LOG_ERROR, 0,
                    BRS_MSG_BAD_OBJECT_DIR_SEEK_FAIL, "off=(0x%llx)", off,
                    "dir=%p", dir, NULL);
            errno = EINVAL;
            count = -1;
            goto out;
        }
#endif /* GF_LINUX_HOST_OS */
    }

    while (filled <= size) {
        in_case = (u_long)telldir(dir);

        if (in_case == -1) {
            gf_smsg(THIS->name, GF_LOG_ERROR, 0,
                    BRS_MSG_BAD_OBJECT_DIR_TELL_FAIL, "dir=%p", dir, "err=%s",
                    strerror(errno), NULL);
            goto out;
        }

        errno = 0;
        entry = sys_readdir(dir, scratch);
        if (!entry || errno != 0) {
            if (errno == EBADF) {
                gf_smsg(THIS->name, GF_LOG_WARNING, 0,
                        BRS_MSG_BAD_OBJECT_DIR_READ_FAIL, "dir=%p", dir,
                        "err=%s", strerror(errno), NULL);
                goto out;
            }
            break;
        }

        if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, ".."))
            continue;

        if (!strncmp(entry->d_name, "stub-", strlen("stub-"))) {
            check_delete_stale_bad_file(this, entry->d_name);
            continue;
        }

        this_size = max(sizeof(gf_dirent_t), sizeof(gfs3_dirplist)) +
                    strlen(entry->d_name) + 1;

        if (this_size + filled > size) {
            seekdir(dir, in_case);
#ifndef GF_LINUX_HOST_OS
            if ((u_long)telldir(dir) != in_case &&
                in_case != fctx->bad_object.dir_eof) {
                gf_smsg(THIS->name, GF_LOG_ERROR, 0,
                        BRS_MSG_BAD_OBJECT_DIR_SEEK_FAIL, "in_case=(0x%llx)",
                        in_case, "dir=%p", dir, NULL);
                errno = EINVAL;
                count = -1;
                goto out;
            }
#endif /* GF_LINUX_HOST_OS */
            break;
        }

        this_entry = gf_dirent_for_name(entry->d_name);

        if (!this_entry) {
            gf_smsg(THIS->name, GF_LOG_ERROR, 0,
                    BRS_MSG_CREATE_GF_DIRENT_FAILED, "entry-name=%s",
                    entry->d_name, "err=%s", strerror(errno), NULL);
            goto out;
        }
        /*
         * we store the offset of next entry here, which is
         * probably not intended, but code using syncop_readdir()
         * (glfs-heal.c, afr-self-heald.c, pump.c) rely on it
         * for directory read resumption.
         */
        last_off = (u_long)telldir(dir);
        this_entry->d_off = last_off;
        this_entry->d_ino = entry->d_ino;

        list_add_tail(&this_entry->list, &entries->list);

        filled += this_size;
        count++;
    }

    if ((!sys_readdir(dir, scratch) && (errno == 0))) {
        /* Indicate EOF */
        errno = ENOENT;
        /* Remember EOF offset for later detection */
        fctx->bad_object.dir_eof = last_off;
    }
out:
    return count;
}

int32_t
br_stub_readdir_wrapper(call_frame_t *frame, xlator_t *this, fd_t *fd,
                        size_t size, off_t off, dict_t *xdata)
{
    br_stub_fd_t *fctx = NULL;
    DIR *dir = NULL;
    int ret = -1;
    int32_t op_ret = -1;
    int32_t op_errno = 0;
    int count = 0;
    gf_dirent_t entries;
    gf_boolean_t xdata_unref = _gf_false;
    dict_t *dict = NULL;

    INIT_LIST_HEAD(&entries.list);

    fctx = br_stub_fd_ctx_get(this, fd);
    if (!fctx) {
        gf_smsg(this->name, GF_LOG_WARNING, 0, BRS_MSG_GET_FD_CONTEXT_FAILED,
                "fd=%p", fd, NULL);
        op_errno = -ret;
        goto done;
    }

    dir = fctx->bad_object.dir;

    if (!dir) {
        gf_smsg(this->name, GF_LOG_WARNING, 0, BRS_MSG_BAD_HANDLE_DIR_NULL,
                "fd=%p", fd, NULL);
        op_errno = EINVAL;
        goto done;
    }

    count = br_stub_fill_readdir(fd, fctx, dir, off, size, &entries);

    /* pick ENOENT to indicate EOF */
    op_errno = errno;
    op_ret = count;

    dict = xdata;
    (void)br_stub_bad_objects_path(this, fd, &entries, &dict);
    if (!xdata && dict) {
        xdata = dict;
        xdata_unref = _gf_true;
    }

done:
    STACK_UNWIND_STRICT(readdir, frame, op_ret, op_errno, &entries, xdata);
    gf_dirent_free(&entries);
    if (xdata_unref)
        dict_unref(xdata);
    return 0;
}

/**
 * This function is called to mainly obtain the paths of the corrupt
 * objects (files as of now). Currently scrub status prints only the
 * gfid of the corrupted files. Reason is, bitrot-stub maintains the
 * list of the corrupted objects as entries inside the quarantine
 * directory (<brick export>/.glusterfs/quarantine)
 *
 * And the name of each entry in the qurantine directory is the gfid
 * of the corrupted object. So scrub status will just show that info.
 * But it helps the users a lot if the actual path to the object is
 * also reported. Hence the below function to get that information.
 * The function allocates a new dict to be returned (if it does not
 * get one from the caller of readdir i.e. scrubber as of now), and
 * stores the paths of each corrupted gfid there. The gfid is used as
 * the key and path is used as the value.
 *
 * NOTE: The path will be there in following situations
 * 1) gfid2path option has been enabled (posix xlator option)
 *    and the corrupted file contains the path as an extended
 *    attribute.
 * 2) If the gfid2path option is not enabled, OR if the xattr
 *    is absent, then the inode table should have it.
 *    The path will be there if a name based lookup has happened
 *    on the file which has been corrupted. With lookup a inode and
 *    dentry would be created in the inode table. And the path is
 *    constructed using the in memory inode and dentry. If a lookup
 *    has not happened OR the inode corresponding to the corrupted
 *    file does not exist in the inode table (because it got purged
 *    as lru limit of the inodes exceeded) OR a nameless lookup had
 *    happened to populate the inode in the inode table, then the
 *    path will not be printed in scrub and only the gfid will be there.
 **/
int
br_stub_bad_objects_path(xlator_t *this, fd_t *fd, gf_dirent_t *entries,
                         dict_t **dict)
{
    gf_dirent_t *entry = NULL;
    inode_t *inode = NULL;
    char *hpath = NULL;
    uuid_t gfid = {0};
    int ret = -1;
    dict_t *tmp_dict = NULL;
    char str_gfid[64] = {0};

    if (list_empty(&entries->list))
        return 0;

    tmp_dict = *dict;

    if (!tmp_dict) {
        tmp_dict = dict_new();
        /*
         * If the allocation of dict fails then no need treat it
         * it as a error. This path (or function) is executed when
         * "gluster volume bitrot <volume name> scrub status" is
         * executed, to get the list of the corrupted objects.
         * And the motive of this function is to get the paths of
         * the corrupted objects. If the dict allocation fails, then
         * the scrub status will only show the gfids of those corrupted
         * objects (which is the behavior as of the time of this patch
         * being worked upon). So just return and only the gfids will
         * be shown.
         */
        if (!tmp_dict) {
            gf_smsg(this->name, GF_LOG_ERROR, 0, BRS_MSG_ALLOC_FAILED, NULL);
            goto out;
        }
    }

    list_for_each_entry(entry, &entries->list, list)
    {
        gf_uuid_clear(gfid);
        gf_uuid_parse(entry->d_name, gfid);

        inode = inode_find(fd->inode->table, gfid);

        /* No need to check the return value here.
         * Because @hpath is examined.
         */
        (void)br_stub_get_path_of_gfid(this, fd->inode, inode, gfid, &hpath);

        if (hpath) {
            gf_msg_debug(this->name, 0,
                         "path of the corrupted "
                         "object (gfid: %s) is %s",
                         uuid_utoa(gfid), hpath);
            br_stub_entry_xattr_fill(this, hpath, entry, tmp_dict);
        } else
            gf_smsg(this->name, GF_LOG_WARNING, 0, BRS_MSG_PATH_GET_FAILED,
                    "gfid=%s", uuid_utoa_r(gfid, str_gfid), NULL);

        inode = NULL;
        hpath = NULL;
    }

    ret = 0;
    *dict = tmp_dict;

out:
    return ret;
}

int
br_stub_get_path_of_gfid(xlator_t *this, inode_t *parent, inode_t *inode,
                         uuid_t gfid, char **path)
{
    int32_t ret = -1;
    char gfid_str[64] = {0};

    GF_VALIDATE_OR_GOTO("bitrot-stub", this, out);
    GF_VALIDATE_OR_GOTO(this->name, parent, out);
    GF_VALIDATE_OR_GOTO(this->name, path, out);

    /* Above, No need to validate the @inode for hard resolution. Because
     * inode can be NULL and if it is NULL, then syncop_gfid_to_path_hard
     * will allocate a new inode and proceed. So no need to bother about
     * @inode. Because we need it only to send a syncop_getxattr call
     * from inside syncop_gfid_to_path_hard. And getxattr fetches the
     * path from the backend.
     */

    ret = syncop_gfid_to_path_hard(parent->table, FIRST_CHILD(this), gfid,
                                   inode, path, _gf_true);
    if (ret < 0)
        gf_smsg(this->name, GF_LOG_WARNING, 0, BRS_MSG_PATH_GET_FAILED,
                "gfid=%s", uuid_utoa_r(gfid, gfid_str), NULL);

    /*
     * Try with soft resolution of path if hard resolve fails. Because
     * checking the xattr on disk to get the path of a inode (or gfid)
     * is dependent on whether that option is enabled in the posix
     * xlator or not. If it is not enabled, then hard resolution by
     * checking the on disk xattr fails.
     *
     * Thus in such situations fall back to the soft resolution which
     * mainly depends on the inode_path() function. And for using
     * inode_path, @inode has to be linked i.e. a successful lookup should
     * have happened on the gfid (or the path) to link the inode to the
     * inode table. And if @inode is NULL, means, the inode has not been
     * found in the inode table and better not to do inode_path() on the
     * inode which has not been linked.
     */
    if (ret < 0 && inode) {
        ret = syncop_gfid_to_path_hard(parent->table, FIRST_CHILD(this), gfid,
                                       inode, path, _gf_false);
        if (ret < 0)
            gf_smsg(this->name, GF_LOG_WARNING, 0, BRS_MSG_PATH_GET_FAILED,
                    "from-memory  gfid=%s", uuid_utoa_r(gfid, gfid_str), NULL);
    }

out:
    return ret;
}

/**
 * NOTE: If the file has multiple hardlinks (in gluster volume
 * namespace), the path would be one of the hardlinks. Its up to
 * the user to find the remaining hardlinks (using find -samefile)
 * and remove them.
 **/
void
br_stub_entry_xattr_fill(xlator_t *this, char *hpath, gf_dirent_t *entry,
                         dict_t *dict)
{
    int32_t ret = -1;

    GF_VALIDATE_OR_GOTO("bit-rot-stub", this, out);
    GF_VALIDATE_OR_GOTO(this->name, hpath, out);

    /*
     * Use the entry->d_name (which is nothing but the gfid of the
     * corrupted object) as the key. And the value will be the actual
     * path of that object (or file).
     *
     * ALso ignore the dict_set errors. scrubber will get the gfid of
     * the corrupted object for sure. So, for now lets just log the
     * dict_set_dynstr failure and move on.
     */

    ret = dict_set_dynstr(dict, entry->d_name, hpath);
    if (ret)
        gf_smsg(this->name, GF_LOG_WARNING, 0, BRS_MSG_DICT_SET_FAILED,
                "path=%s", hpath, "object-name=%s", entry->d_name, NULL);
out:
    return;
}