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btrfs-progs: image: add reverse CRC32C table
[btrfs-progs-unstable/devel.git] / utils.c
blob7a2710fe57415c9e8e913827db6f3bbf5de3c40b
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 * Copyright (C) 2008 Morey Roof. All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public
7 * License v2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public
15 * License along with this program; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 021110-1307, USA.
18 */
19
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/ioctl.h>
24 #include <sys/mount.h>
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <uuid/uuid.h>
28 #include <fcntl.h>
29 #include <unistd.h>
30 #include <mntent.h>
31 #include <ctype.h>
32 #include <linux/loop.h>
33 #include <linux/major.h>
34 #include <linux/kdev_t.h>
35 #include <limits.h>
36 #include <blkid/blkid.h>
37 #include <sys/vfs.h>
38 #include <sys/statfs.h>
39 #include <linux/magic.h>
40 #include <getopt.h>
41
42 #include "kerncompat.h"
43 #include "radix-tree.h"
44 #include "ctree.h"
45 #include "disk-io.h"
46 #include "transaction.h"
47 #include "crc32c.h"
48 #include "utils.h"
49 #include "volumes.h"
50 #include "ioctl.h"
51 #include "commands.h"
52 #include "mkfs/common.h"
53
54 #ifndef BLKDISCARD
55 #define BLKDISCARD _IO(0x12,119)
56 #endif
57
58 static int btrfs_scan_done = 0;
59
60 static int rand_seed_initlized = 0;
61 static unsigned short rand_seed[3];
62
63 struct btrfs_config bconf;
64
65 /*
66 * Discard the given range in one go
67 */
68 static int discard_range(int fd, u64 start, u64 len)
69 {
70 u64 range[2] = { start, len };
71
72 if (ioctl(fd, BLKDISCARD, &range) < 0)
73 return errno;
74 return 0;
75 }
76
77 /*
78 * Discard blocks in the given range in 1G chunks, the process is interruptible
79 */
80 static int discard_blocks(int fd, u64 start, u64 len)
81 {
82 while (len > 0) {
83 /* 1G granularity */
84 u64 chunk_size = min_t(u64, len, SZ_1G);
85 int ret;
86
87 ret = discard_range(fd, start, chunk_size);
88 if (ret)
89 return ret;
90 len -= chunk_size;
91 start += chunk_size;
92 }
93
94 return 0;
95 }
96
97 int test_uuid_unique(char *fs_uuid)
98 {
99 int unique = 1;
100 blkid_dev_iterate iter = NULL;
101 blkid_dev dev = NULL;
102 blkid_cache cache = NULL;
103
104 if (blkid_get_cache(&cache, NULL) < 0) {
105 printf("ERROR: lblkid cache get failed\n");
106 return 1;
107 }
108 blkid_probe_all(cache);
109 iter = blkid_dev_iterate_begin(cache);
110 blkid_dev_set_search(iter, "UUID", fs_uuid);
111
112 while (blkid_dev_next(iter, &dev) == 0) {
113 dev = blkid_verify(cache, dev);
114 if (dev) {
115 unique = 0;
116 break;
117 }
118 }
119
120 blkid_dev_iterate_end(iter);
121 blkid_put_cache(cache);
122
123 return unique;
124 }
125
126 u64 btrfs_device_size(int fd, struct stat *st)
127 {
128 u64 size;
129 if (S_ISREG(st->st_mode)) {
130 return st->st_size;
131 }
132 if (!S_ISBLK(st->st_mode)) {
133 return 0;
134 }
135 if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
136 return size;
137 }
138 return 0;
139 }
140
141 static int zero_blocks(int fd, off_t start, size_t len)
142 {
143 char *buf = malloc(len);
144 int ret = 0;
145 ssize_t written;
146
147 if (!buf)
148 return -ENOMEM;
149 memset(buf, 0, len);
150 written = pwrite(fd, buf, len, start);
151 if (written != len)
152 ret = -EIO;
153 free(buf);
154 return ret;
155 }
156
157 #define ZERO_DEV_BYTES SZ_2M
158
159 /* don't write outside the device by clamping the region to the device size */
160 static int zero_dev_clamped(int fd, off_t start, ssize_t len, u64 dev_size)
161 {
162 off_t end = max(start, start + len);
163
164 #ifdef __sparc__
165 /* and don't overwrite the disk labels on sparc */
166 start = max(start, 1024);
167 end = max(end, 1024);
168 #endif
169
170 start = min_t(u64, start, dev_size);
171 end = min_t(u64, end, dev_size);
172
173 return zero_blocks(fd, start, end - start);
174 }
175
176 int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
177 struct btrfs_root *root, int fd, const char *path,
178 u64 device_total_bytes, u32 io_width, u32 io_align,
179 u32 sectorsize)
180 {
181 struct btrfs_super_block *disk_super;
182 struct btrfs_fs_info *fs_info = root->fs_info;
183 struct btrfs_super_block *super = fs_info->super_copy;
184 struct btrfs_device *device;
185 struct btrfs_dev_item *dev_item;
186 char *buf = NULL;
187 u64 fs_total_bytes;
188 u64 num_devs;
189 int ret;
190
191 device_total_bytes = (device_total_bytes / sectorsize) * sectorsize;
192
193 device = calloc(1, sizeof(*device));
194 if (!device) {
195 ret = -ENOMEM;
196 goto out;
197 }
198 buf = calloc(1, sectorsize);
199 if (!buf) {
200 ret = -ENOMEM;
201 goto out;
202 }
203
204 disk_super = (struct btrfs_super_block *)buf;
205 dev_item = &disk_super->dev_item;
206
207 uuid_generate(device->uuid);
208 device->devid = 0;
209 device->type = 0;
210 device->io_width = io_width;
211 device->io_align = io_align;
212 device->sector_size = sectorsize;
213 device->fd = fd;
214 device->writeable = 1;
215 device->total_bytes = device_total_bytes;
216 device->bytes_used = 0;
217 device->total_ios = 0;
218 device->dev_root = fs_info->dev_root;
219 device->name = strdup(path);
220 if (!device->name) {
221 ret = -ENOMEM;
222 goto out;
223 }
224
225 INIT_LIST_HEAD(&device->dev_list);
226 ret = btrfs_add_device(trans, fs_info, device);
227 if (ret)
228 goto out;
229
230 fs_total_bytes = btrfs_super_total_bytes(super) + device_total_bytes;
231 btrfs_set_super_total_bytes(super, fs_total_bytes);
232
233 num_devs = btrfs_super_num_devices(super) + 1;
234 btrfs_set_super_num_devices(super, num_devs);
235
236 memcpy(disk_super, super, sizeof(*disk_super));
237
238 btrfs_set_super_bytenr(disk_super, BTRFS_SUPER_INFO_OFFSET);
239 btrfs_set_stack_device_id(dev_item, device->devid);
240 btrfs_set_stack_device_type(dev_item, device->type);
241 btrfs_set_stack_device_io_align(dev_item, device->io_align);
242 btrfs_set_stack_device_io_width(dev_item, device->io_width);
243 btrfs_set_stack_device_sector_size(dev_item, device->sector_size);
244 btrfs_set_stack_device_total_bytes(dev_item, device->total_bytes);
245 btrfs_set_stack_device_bytes_used(dev_item, device->bytes_used);
246 memcpy(&dev_item->uuid, device->uuid, BTRFS_UUID_SIZE);
247
248 ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
249 BUG_ON(ret != sectorsize);
250
251 free(buf);
252 list_add(&device->dev_list, &fs_info->fs_devices->devices);
253 device->fs_devices = fs_info->fs_devices;
254 return 0;
255
256 out:
257 free(device);
258 free(buf);
259 return ret;
260 }
261
262 static int btrfs_wipe_existing_sb(int fd)
263 {
264 const char *off = NULL;
265 size_t len = 0;
266 loff_t offset;
267 char buf[BUFSIZ];
268 int ret = 0;
269 blkid_probe pr = NULL;
270
271 pr = blkid_new_probe();
272 if (!pr)
273 return -1;
274
275 if (blkid_probe_set_device(pr, fd, 0, 0)) {
276 ret = -1;
277 goto out;
278 }
279
280 ret = blkid_probe_lookup_value(pr, "SBMAGIC_OFFSET", &off, NULL);
281 if (!ret)
282 ret = blkid_probe_lookup_value(pr, "SBMAGIC", NULL, &len);
283
284 if (ret || len == 0 || off == NULL) {
285 /*
286 * If lookup fails, the probe did not find any values, eg. for
287 * a file image or a loop device. Soft error.
288 */
289 ret = 1;
290 goto out;
291 }
292
293 offset = strtoll(off, NULL, 10);
294 if (len > sizeof(buf))
295 len = sizeof(buf);
296
297 memset(buf, 0, len);
298 ret = pwrite(fd, buf, len, offset);
299 if (ret < 0) {
300 error("cannot wipe existing superblock: %s", strerror(errno));
301 ret = -1;
302 } else if (ret != len) {
303 error("cannot wipe existing superblock: wrote %d of %zd", ret, len);
304 ret = -1;
305 }
306 fsync(fd);
307
308 out:
309 blkid_free_probe(pr);
310 return ret;
311 }
312
313 int btrfs_prepare_device(int fd, const char *file, u64 *block_count_ret,
314 u64 max_block_count, unsigned opflags)
315 {
316 u64 block_count;
317 struct stat st;
318 int i, ret;
319
320 ret = fstat(fd, &st);
321 if (ret < 0) {
322 error("unable to stat %s: %s", file, strerror(errno));
323 return 1;
324 }
325
326 block_count = btrfs_device_size(fd, &st);
327 if (block_count == 0) {
328 error("unable to determine size of %s", file);
329 return 1;
330 }
331 if (max_block_count)
332 block_count = min(block_count, max_block_count);
333
334 if (opflags & PREP_DEVICE_DISCARD) {
335 /*
336 * We intentionally ignore errors from the discard ioctl. It
337 * is not necessary for the mkfs functionality but just an
338 * optimization.
339 */
340 if (discard_range(fd, 0, 0) == 0) {
341 if (opflags & PREP_DEVICE_VERBOSE)
342 printf("Performing full device TRIM %s (%s) ...\n",
343 file, pretty_size(block_count));
344 discard_blocks(fd, 0, block_count);
345 }
346 }
347
348 ret = zero_dev_clamped(fd, 0, ZERO_DEV_BYTES, block_count);
349 for (i = 0 ; !ret && i < BTRFS_SUPER_MIRROR_MAX; i++)
350 ret = zero_dev_clamped(fd, btrfs_sb_offset(i),
351 BTRFS_SUPER_INFO_SIZE, block_count);
352 if (!ret && (opflags & PREP_DEVICE_ZERO_END))
353 ret = zero_dev_clamped(fd, block_count - ZERO_DEV_BYTES,
354 ZERO_DEV_BYTES, block_count);
355
356 if (ret < 0) {
357 error("failed to zero device '%s': %s", file, strerror(-ret));
358 return 1;
359 }
360
361 ret = btrfs_wipe_existing_sb(fd);
362 if (ret < 0) {
363 error("cannot wipe superblocks on %s", file);
364 return 1;
365 }
366
367 *block_count_ret = block_count;
368 return 0;
369 }
370
371 int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
372 struct btrfs_root *root, u64 objectid)
373 {
374 int ret;
375 struct btrfs_inode_item inode_item;
376 time_t now = time(NULL);
377
378 memset(&inode_item, 0, sizeof(inode_item));
379 btrfs_set_stack_inode_generation(&inode_item, trans->transid);
380 btrfs_set_stack_inode_size(&inode_item, 0);
381 btrfs_set_stack_inode_nlink(&inode_item, 1);
382 btrfs_set_stack_inode_nbytes(&inode_item, root->fs_info->nodesize);
383 btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);
384 btrfs_set_stack_timespec_sec(&inode_item.atime, now);
385 btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);
386 btrfs_set_stack_timespec_sec(&inode_item.ctime, now);
387 btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);
388 btrfs_set_stack_timespec_sec(&inode_item.mtime, now);
389 btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);
390 btrfs_set_stack_timespec_sec(&inode_item.otime, now);
391 btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);
392
393 if (root->fs_info->tree_root == root)
394 btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);
395
396 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
397 if (ret)
398 goto error;
399
400 ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);
401 if (ret)
402 goto error;
403
404 btrfs_set_root_dirid(&root->root_item, objectid);
405 ret = 0;
406 error:
407 return ret;
408 }
409
410 /*
411 * checks if a path is a block device node
412 * Returns negative errno on failure, otherwise
413 * returns 1 for blockdev, 0 for not-blockdev
414 */
415 int is_block_device(const char *path)
416 {
417 struct stat statbuf;
418
419 if (stat(path, &statbuf) < 0)
420 return -errno;
421
422 return !!S_ISBLK(statbuf.st_mode);
423 }
424
425 /*
426 * check if given path is a mount point
427 * return 1 if yes. 0 if no. -1 for error
428 */
429 int is_mount_point(const char *path)
430 {
431 FILE *f;
432 struct mntent *mnt;
433 int ret = 0;
434
435 f = setmntent("/proc/self/mounts", "r");
436 if (f == NULL)
437 return -1;
438
439 while ((mnt = getmntent(f)) != NULL) {
440 if (strcmp(mnt->mnt_dir, path))
441 continue;
442 ret = 1;
443 break;
444 }
445 endmntent(f);
446 return ret;
447 }
448
449 static int is_reg_file(const char *path)
450 {
451 struct stat statbuf;
452
453 if (stat(path, &statbuf) < 0)
454 return -errno;
455 return S_ISREG(statbuf.st_mode);
456 }
457
458 /*
459 * This function checks if the given input parameter is
460 * an uuid or a path
461 * return <0 : some error in the given input
462 * return BTRFS_ARG_UNKNOWN: unknown input
463 * return BTRFS_ARG_UUID: given input is uuid
464 * return BTRFS_ARG_MNTPOINT: given input is path
465 * return BTRFS_ARG_REG: given input is regular file
466 * return BTRFS_ARG_BLKDEV: given input is block device
467 */
468 int check_arg_type(const char *input)
469 {
470 uuid_t uuid;
471 char path[PATH_MAX];
472
473 if (!input)
474 return -EINVAL;
475
476 if (realpath(input, path)) {
477 if (is_block_device(path) == 1)
478 return BTRFS_ARG_BLKDEV;
479
480 if (is_mount_point(path) == 1)
481 return BTRFS_ARG_MNTPOINT;
482
483 if (is_reg_file(path))
484 return BTRFS_ARG_REG;
485
486 return BTRFS_ARG_UNKNOWN;
487 }
488
489 if (strlen(input) == (BTRFS_UUID_UNPARSED_SIZE - 1) &&
490 !uuid_parse(input, uuid))
491 return BTRFS_ARG_UUID;
492
493 return BTRFS_ARG_UNKNOWN;
494 }
495
496 /*
497 * Find the mount point for a mounted device.
498 * On success, returns 0 with mountpoint in *mp.
499 * On failure, returns -errno (not mounted yields -EINVAL)
500 * Is noisy on failures, expects to be given a mounted device.
501 */
502 int get_btrfs_mount(const char *dev, char *mp, size_t mp_size)
503 {
504 int ret;
505 int fd = -1;
506
507 ret = is_block_device(dev);
508 if (ret <= 0) {
509 if (!ret) {
510 error("not a block device: %s", dev);
511 ret = -EINVAL;
512 } else {
513 error("cannot check %s: %s", dev, strerror(-ret));
514 }
515 goto out;
516 }
517
518 fd = open(dev, O_RDONLY);
519 if (fd < 0) {
520 ret = -errno;
521 error("cannot open %s: %s", dev, strerror(errno));
522 goto out;
523 }
524
525 ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
526 if (!ret) {
527 ret = -EINVAL;
528 } else { /* mounted, all good */
529 ret = 0;
530 }
531 out:
532 if (fd != -1)
533 close(fd);
534 return ret;
535 }
536
537 /*
538 * Given a pathname, return a filehandle to:
539 * the original pathname or,
540 * if the pathname is a mounted btrfs device, to its mountpoint.
541 *
542 * On error, return -1, errno should be set.
543 */
544 int open_path_or_dev_mnt(const char *path, DIR **dirstream, int verbose)
545 {
546 char mp[PATH_MAX];
547 int ret;
548
549 if (is_block_device(path)) {
550 ret = get_btrfs_mount(path, mp, sizeof(mp));
551 if (ret < 0) {
552 /* not a mounted btrfs dev */
553 error_on(verbose, "'%s' is not a mounted btrfs device",
554 path);
555 errno = EINVAL;
556 return -1;
557 }
558 ret = open_file_or_dir(mp, dirstream);
559 error_on(verbose && ret < 0, "can't access '%s': %s",
560 path, strerror(errno));
561 } else {
562 ret = btrfs_open_dir(path, dirstream, 1);
563 }
564
565 return ret;
566 }
567
568 /*
569 * Do the following checks before calling open_file_or_dir():
570 * 1: path is in a btrfs filesystem
571 * 2: path is a directory if dir_only is 1
572 */
573 int btrfs_open(const char *path, DIR **dirstream, int verbose, int dir_only)
574 {
575 struct statfs stfs;
576 struct stat st;
577 int ret;
578
579 if (statfs(path, &stfs) != 0) {
580 error_on(verbose, "cannot access '%s': %s", path,
581 strerror(errno));
582 return -1;
583 }
584
585 if (stfs.f_type != BTRFS_SUPER_MAGIC) {
586 error_on(verbose, "not a btrfs filesystem: %s", path);
587 return -2;
588 }
589
590 if (stat(path, &st) != 0) {
591 error_on(verbose, "cannot access '%s': %s", path,
592 strerror(errno));
593 return -1;
594 }
595
596 if (dir_only && !S_ISDIR(st.st_mode)) {
597 error_on(verbose, "not a directory: %s", path);
598 return -3;
599 }
600
601 ret = open_file_or_dir(path, dirstream);
602 if (ret < 0) {
603 error_on(verbose, "cannot access '%s': %s", path,
604 strerror(errno));
605 }
606
607 return ret;
608 }
609
610 int btrfs_open_dir(const char *path, DIR **dirstream, int verbose)
611 {
612 return btrfs_open(path, dirstream, verbose, 1);
613 }
614
615 int btrfs_open_file_or_dir(const char *path, DIR **dirstream, int verbose)
616 {
617 return btrfs_open(path, dirstream, verbose, 0);
618 }
619
620 /* checks if a device is a loop device */
621 static int is_loop_device (const char* device) {
622 struct stat statbuf;
623
624 if(stat(device, &statbuf) < 0)
625 return -errno;
626
627 return (S_ISBLK(statbuf.st_mode) &&
628 MAJOR(statbuf.st_rdev) == LOOP_MAJOR);
629 }
630
631 /*
632 * Takes a loop device path (e.g. /dev/loop0) and returns
633 * the associated file (e.g. /images/my_btrfs.img) using
634 * loopdev API
635 */
636 static int resolve_loop_device_with_loopdev(const char* loop_dev, char* loop_file)
637 {
638 int fd;
639 int ret;
640 struct loop_info64 lo64;
641
642 fd = open(loop_dev, O_RDONLY | O_NONBLOCK);
643 if (fd < 0)
644 return -errno;
645 ret = ioctl(fd, LOOP_GET_STATUS64, &lo64);
646 if (ret < 0) {
647 ret = -errno;
648 goto out;
649 }
650
651 memcpy(loop_file, lo64.lo_file_name, sizeof(lo64.lo_file_name));
652 loop_file[sizeof(lo64.lo_file_name)] = 0;
653
654 out:
655 close(fd);
656
657 return ret;
658 }
659
660 /* Takes a loop device path (e.g. /dev/loop0) and returns
661 * the associated file (e.g. /images/my_btrfs.img) */
662 static int resolve_loop_device(const char* loop_dev, char* loop_file,
663 int max_len)
664 {
665 int ret;
666 FILE *f;
667 char fmt[20];
668 char p[PATH_MAX];
669 char real_loop_dev[PATH_MAX];
670
671 if (!realpath(loop_dev, real_loop_dev))
672 return -errno;
673 snprintf(p, PATH_MAX, "/sys/block/%s/loop/backing_file", strrchr(real_loop_dev, '/'));
674 if (!(f = fopen(p, "r"))) {
675 if (errno == ENOENT)
676 /*
677 * It's possibly a partitioned loop device, which is
678 * resolvable with loopdev API.
679 */
680 return resolve_loop_device_with_loopdev(loop_dev, loop_file);
681 return -errno;
682 }
683
684 snprintf(fmt, 20, "%%%i[^\n]", max_len-1);
685 ret = fscanf(f, fmt, loop_file);
686 fclose(f);
687 if (ret == EOF)
688 return -errno;
689
690 return 0;
691 }
692
693 /*
694 * Checks whether a and b are identical or device
695 * files associated with the same block device
696 */
697 static int is_same_blk_file(const char* a, const char* b)
698 {
699 struct stat st_buf_a, st_buf_b;
700 char real_a[PATH_MAX];
701 char real_b[PATH_MAX];
702
703 if (!realpath(a, real_a))
704 strncpy_null(real_a, a);
705
706 if (!realpath(b, real_b))
707 strncpy_null(real_b, b);
708
709 /* Identical path? */
710 if (strcmp(real_a, real_b) == 0)
711 return 1;
712
713 if (stat(a, &st_buf_a) < 0 || stat(b, &st_buf_b) < 0) {
714 if (errno == ENOENT)
715 return 0;
716 return -errno;
717 }
718
719 /* Same blockdevice? */
720 if (S_ISBLK(st_buf_a.st_mode) && S_ISBLK(st_buf_b.st_mode) &&
721 st_buf_a.st_rdev == st_buf_b.st_rdev) {
722 return 1;
723 }
724
725 /* Hardlink? */
726 if (st_buf_a.st_dev == st_buf_b.st_dev &&
727 st_buf_a.st_ino == st_buf_b.st_ino) {
728 return 1;
729 }
730
731 return 0;
732 }
733
734 /* checks if a and b are identical or device
735 * files associated with the same block device or
736 * if one file is a loop device that uses the other
737 * file.
738 */
739 static int is_same_loop_file(const char* a, const char* b)
740 {
741 char res_a[PATH_MAX];
742 char res_b[PATH_MAX];
743 const char* final_a = NULL;
744 const char* final_b = NULL;
745 int ret;
746
747 /* Resolve a if it is a loop device */
748 if((ret = is_loop_device(a)) < 0) {
749 if (ret == -ENOENT)
750 return 0;
751 return ret;
752 } else if (ret) {
753 ret = resolve_loop_device(a, res_a, sizeof(res_a));
754 if (ret < 0) {
755 if (errno != EPERM)
756 return ret;
757 } else {
758 final_a = res_a;
759 }
760 } else {
761 final_a = a;
762 }
763
764 /* Resolve b if it is a loop device */
765 if ((ret = is_loop_device(b)) < 0) {
766 if (ret == -ENOENT)
767 return 0;
768 return ret;
769 } else if (ret) {
770 ret = resolve_loop_device(b, res_b, sizeof(res_b));
771 if (ret < 0) {
772 if (errno != EPERM)
773 return ret;
774 } else {
775 final_b = res_b;
776 }
777 } else {
778 final_b = b;
779 }
780
781 return is_same_blk_file(final_a, final_b);
782 }
783
784 /* Checks if a file exists and is a block or regular file*/
785 static int is_existing_blk_or_reg_file(const char* filename)
786 {
787 struct stat st_buf;
788
789 if(stat(filename, &st_buf) < 0) {
790 if(errno == ENOENT)
791 return 0;
792 else
793 return -errno;
794 }
795
796 return (S_ISBLK(st_buf.st_mode) || S_ISREG(st_buf.st_mode));
797 }
798
799 /* Checks if a file is used (directly or indirectly via a loop device)
800 * by a device in fs_devices
801 */
802 static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices,
803 const char* file)
804 {
805 int ret;
806 struct list_head *head;
807 struct list_head *cur;
808 struct btrfs_device *device;
809
810 head = &fs_devices->devices;
811 list_for_each(cur, head) {
812 device = list_entry(cur, struct btrfs_device, dev_list);
813
814 if((ret = is_same_loop_file(device->name, file)))
815 return ret;
816 }
817
818 return 0;
819 }
820
821 /*
822 * Resolve a pathname to a device mapper node to /dev/mapper/<name>
823 * Returns NULL on invalid input or malloc failure; Other failures
824 * will be handled by the caller using the input pathame.
825 */
826 char *canonicalize_dm_name(const char *ptname)
827 {
828 FILE *f;
829 size_t sz;
830 char path[PATH_MAX], name[PATH_MAX], *res = NULL;
831
832 if (!ptname || !*ptname)
833 return NULL;
834
835 snprintf(path, sizeof(path), "/sys/block/%s/dm/name", ptname);
836 if (!(f = fopen(path, "r")))
837 return NULL;
838
839 /* read <name>\n from sysfs */
840 if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) {
841 name[sz - 1] = '\0';
842 snprintf(path, sizeof(path), "/dev/mapper/%s", name);
843
844 if (access(path, F_OK) == 0)
845 res = strdup(path);
846 }
847 fclose(f);
848 return res;
849 }
850
851 /*
852 * Resolve a pathname to a canonical device node, e.g. /dev/sda1 or
853 * to a device mapper pathname.
854 * Returns NULL on invalid input or malloc failure; Other failures
855 * will be handled by the caller using the input pathame.
856 */
857 char *canonicalize_path(const char *path)
858 {
859 char *canonical, *p;
860
861 if (!path || !*path)
862 return NULL;
863
864 canonical = realpath(path, NULL);
865 if (!canonical)
866 return strdup(path);
867 p = strrchr(canonical, '/');
868 if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4))) {
869 char *dm = canonicalize_dm_name(p + 1);
870
871 if (dm) {
872 free(canonical);
873 return dm;
874 }
875 }
876 return canonical;
877 }
878
879 /*
880 * returns 1 if the device was mounted, < 0 on error or 0 if everything
881 * is safe to continue.
882 */
883 int check_mounted(const char* file)
884 {
885 int fd;
886 int ret;
887
888 fd = open(file, O_RDONLY);
889 if (fd < 0) {
890 error("mount check: cannot open %s: %s", file,
891 strerror(errno));
892 return -errno;
893 }
894
895 ret = check_mounted_where(fd, file, NULL, 0, NULL);
896 close(fd);
897
898 return ret;
899 }
900
901 int check_mounted_where(int fd, const char *file, char *where, int size,
902 struct btrfs_fs_devices **fs_dev_ret)
903 {
904 int ret;
905 u64 total_devs = 1;
906 int is_btrfs;
907 struct btrfs_fs_devices *fs_devices_mnt = NULL;
908 FILE *f;
909 struct mntent *mnt;
910
911 /* scan the initial device */
912 ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
913 &total_devs, BTRFS_SUPER_INFO_OFFSET, SBREAD_DEFAULT);
914 is_btrfs = (ret >= 0);
915
916 /* scan other devices */
917 if (is_btrfs && total_devs > 1) {
918 ret = btrfs_scan_devices();
919 if (ret)
920 return ret;
921 }
922
923 /* iterate over the list of currently mounted filesystems */
924 if ((f = setmntent ("/proc/self/mounts", "r")) == NULL)
925 return -errno;
926
927 while ((mnt = getmntent (f)) != NULL) {
928 if(is_btrfs) {
929 if(strcmp(mnt->mnt_type, "btrfs") != 0)
930 continue;
931
932 ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname);
933 } else {
934 /* ignore entries in the mount table that are not
935 associated with a file*/
936 if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0)
937 goto out_mntloop_err;
938 else if(!ret)
939 continue;
940
941 ret = is_same_loop_file(file, mnt->mnt_fsname);
942 }
943
944 if(ret < 0)
945 goto out_mntloop_err;
946 else if(ret)
947 break;
948 }
949
950 /* Did we find an entry in mnt table? */
951 if (mnt && size && where) {
952 strncpy(where, mnt->mnt_dir, size);
953 where[size-1] = 0;
954 }
955 if (fs_dev_ret)
956 *fs_dev_ret = fs_devices_mnt;
957
958 ret = (mnt != NULL);
959
960 out_mntloop_err:
961 endmntent (f);
962
963 return ret;
964 }
965
966 struct pending_dir {
967 struct list_head list;
968 char name[PATH_MAX];
969 };
970
971 int btrfs_register_one_device(const char *fname)
972 {
973 struct btrfs_ioctl_vol_args args;
974 int fd;
975 int ret;
976
977 fd = open("/dev/btrfs-control", O_RDWR);
978 if (fd < 0) {
979 warning(
980 "failed to open /dev/btrfs-control, skipping device registration: %s",
981 strerror(errno));
982 return -errno;
983 }
984 memset(&args, 0, sizeof(args));
985 strncpy_null(args.name, fname);
986 ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
987 if (ret < 0) {
988 error("device scan failed on '%s': %s", fname,
989 strerror(errno));
990 ret = -errno;
991 }
992 close(fd);
993 return ret;
994 }
995
996 /*
997 * Register all devices in the fs_uuid list created in the user
998 * space. Ensure btrfs_scan_devices() is called before this func.
999 */
1000 int btrfs_register_all_devices(void)
1001 {
1002 int err = 0;
1003 int ret = 0;
1004 struct btrfs_fs_devices *fs_devices;
1005 struct btrfs_device *device;
1006 struct list_head *all_uuids;
1007
1008 all_uuids = btrfs_scanned_uuids();
1009
1010 list_for_each_entry(fs_devices, all_uuids, list) {
1011 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1012 if (*device->name)
1013 err = btrfs_register_one_device(device->name);
1014
1015 if (err)
1016 ret++;
1017 }
1018 }
1019
1020 return ret;
1021 }
1022
1023 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
1024 int super_offset)
1025 {
1026 struct btrfs_super_block *disk_super;
1027 char *buf;
1028 int ret = 0;
1029
1030 buf = malloc(BTRFS_SUPER_INFO_SIZE);
1031 if (!buf) {
1032 ret = -ENOMEM;
1033 goto out;
1034 }
1035 ret = pread(fd, buf, BTRFS_SUPER_INFO_SIZE, super_offset);
1036 if (ret != BTRFS_SUPER_INFO_SIZE)
1037 goto brelse;
1038
1039 ret = 0;
1040 disk_super = (struct btrfs_super_block *)buf;
1041 /*
1042 * Accept devices from the same filesystem, allow partially created
1043 * structures.
1044 */
1045 if (btrfs_super_magic(disk_super) != BTRFS_MAGIC &&
1046 btrfs_super_magic(disk_super) != BTRFS_MAGIC_PARTIAL)
1047 goto brelse;
1048
1049 if (!memcmp(disk_super->fsid, root->fs_info->super_copy->fsid,
1050 BTRFS_FSID_SIZE))
1051 ret = 1;
1052 brelse:
1053 free(buf);
1054 out:
1055 return ret;
1056 }
1057
1058 /*
1059 * Note: this function uses a static per-thread buffer. Do not call this
1060 * function more than 10 times within one argument list!
1061 */
1062 const char *pretty_size_mode(u64 size, unsigned mode)
1063 {
1064 static __thread int ps_index = 0;
1065 static __thread char ps_array[10][32];
1066 char *ret;
1067
1068 ret = ps_array[ps_index];
1069 ps_index++;
1070 ps_index %= 10;
1071 (void)pretty_size_snprintf(size, ret, 32, mode);
1072
1073 return ret;
1074 }
1075
1076 static const char* unit_suffix_binary[] =
1077 { "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"};
1078 static const char* unit_suffix_decimal[] =
1079 { "B", "kB", "MB", "GB", "TB", "PB", "EB"};
1080
1081 int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode)
1082 {
1083 int num_divs;
1084 float fraction;
1085 u64 base = 0;
1086 int mult = 0;
1087 const char** suffix = NULL;
1088 u64 last_size;
1089 int negative;
1090
1091 if (str_size == 0)
1092 return 0;
1093
1094 negative = !!(unit_mode & UNITS_NEGATIVE);
1095 unit_mode &= ~UNITS_NEGATIVE;
1096
1097 if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) {
1098 if (negative)
1099 snprintf(str, str_size, "%lld", size);
1100 else
1101 snprintf(str, str_size, "%llu", size);
1102 return 0;
1103 }
1104
1105 if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_BINARY) {
1106 base = 1024;
1107 mult = 1024;
1108 suffix = unit_suffix_binary;
1109 } else if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_DECIMAL) {
1110 base = 1000;
1111 mult = 1000;
1112 suffix = unit_suffix_decimal;
1113 }
1114
1115 /* Unknown mode */
1116 if (!base) {
1117 fprintf(stderr, "INTERNAL ERROR: unknown unit base, mode %d\n",
1118 unit_mode);
1119 assert(0);
1120 return -1;
1121 }
1122
1123 num_divs = 0;
1124 last_size = size;
1125 switch (unit_mode & UNITS_MODE_MASK) {
1126 case UNITS_TBYTES: base *= mult; num_divs++;
1127 case UNITS_GBYTES: base *= mult; num_divs++;
1128 case UNITS_MBYTES: base *= mult; num_divs++;
1129 case UNITS_KBYTES: num_divs++;
1130 break;
1131 case UNITS_BYTES:
1132 base = 1;
1133 num_divs = 0;
1134 break;
1135 default:
1136 if (negative) {
1137 s64 ssize = (s64)size;
1138 s64 last_ssize = ssize;
1139
1140 while ((ssize < 0 ? -ssize : ssize) >= mult) {
1141 last_ssize = ssize;
1142 ssize /= mult;
1143 num_divs++;
1144 }
1145 last_size = (u64)last_ssize;
1146 } else {
1147 while (size >= mult) {
1148 last_size = size;
1149 size /= mult;
1150 num_divs++;
1151 }
1152 }
1153 /*
1154 * If the value is smaller than base, we didn't do any
1155 * division, in that case, base should be 1, not original
1156 * base, or the unit will be wrong
1157 */
1158 if (num_divs == 0)
1159 base = 1;
1160 }
1161
1162 if (num_divs >= ARRAY_SIZE(unit_suffix_binary)) {
1163 str[0] = '\0';
1164 printf("INTERNAL ERROR: unsupported unit suffix, index %d\n",
1165 num_divs);
1166 assert(0);
1167 return -1;
1168 }
1169
1170 if (negative) {
1171 fraction = (float)(s64)last_size / base;
1172 } else {
1173 fraction = (float)last_size / base;
1174 }
1175
1176 return snprintf(str, str_size, "%.2f%s", fraction, suffix[num_divs]);
1177 }
1178
1179 /*
1180 * __strncpy_null - strncpy with null termination
1181 * @dest: the target array
1182 * @src: the source string
1183 * @n: maximum bytes to copy (size of *dest)
1184 *
1185 * Like strncpy, but ensures destination is null-terminated.
1186 *
1187 * Copies the string pointed to by src, including the terminating null
1188 * byte ('\0'), to the buffer pointed to by dest, up to a maximum
1189 * of n bytes. Then ensure that dest is null-terminated.
1190 */
1191 char *__strncpy_null(char *dest, const char *src, size_t n)
1192 {
1193 strncpy(dest, src, n);
1194 if (n > 0)
1195 dest[n - 1] = '\0';
1196 return dest;
1197 }
1198
1199 /*
1200 * Checks to make sure that the label matches our requirements.
1201 * Returns:
1202 0 if everything is safe and usable
1203 -1 if the label is too long
1204 */
1205 static int check_label(const char *input)
1206 {
1207 int len = strlen(input);
1208
1209 if (len > BTRFS_LABEL_SIZE - 1) {
1210 error("label %s is too long (max %d)", input,
1211 BTRFS_LABEL_SIZE - 1);
1212 return -1;
1213 }
1214
1215 return 0;
1216 }
1217
1218 static int set_label_unmounted(const char *dev, const char *label)
1219 {
1220 struct btrfs_trans_handle *trans;
1221 struct btrfs_root *root;
1222 int ret;
1223
1224 ret = check_mounted(dev);
1225 if (ret < 0) {
1226 error("checking mount status of %s failed: %d", dev, ret);
1227 return -1;
1228 }
1229 if (ret > 0) {
1230 error("device %s is mounted, use mount point", dev);
1231 return -1;
1232 }
1233
1234 /* Open the super_block at the default location
1235 * and as read-write.
1236 */
1237 root = open_ctree(dev, 0, OPEN_CTREE_WRITES);
1238 if (!root) /* errors are printed by open_ctree() */
1239 return -1;
1240
1241 trans = btrfs_start_transaction(root, 1);
1242 BUG_ON(IS_ERR(trans));
1243 __strncpy_null(root->fs_info->super_copy->label, label, BTRFS_LABEL_SIZE - 1);
1244
1245 btrfs_commit_transaction(trans, root);
1246
1247 /* Now we close it since we are done. */
1248 close_ctree(root);
1249 return 0;
1250 }
1251
1252 static int set_label_mounted(const char *mount_path, const char *labelp)
1253 {
1254 int fd;
1255 char label[BTRFS_LABEL_SIZE];
1256
1257 fd = open(mount_path, O_RDONLY | O_NOATIME);
1258 if (fd < 0) {
1259 error("unable to access %s: %s", mount_path, strerror(errno));
1260 return -1;
1261 }
1262
1263 memset(label, 0, sizeof(label));
1264 __strncpy_null(label, labelp, BTRFS_LABEL_SIZE - 1);
1265 if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) {
1266 error("unable to set label of %s: %s", mount_path,
1267 strerror(errno));
1268 close(fd);
1269 return -1;
1270 }
1271
1272 close(fd);
1273 return 0;
1274 }
1275
1276 int get_label_unmounted(const char *dev, char *label)
1277 {
1278 struct btrfs_root *root;
1279 int ret;
1280
1281 ret = check_mounted(dev);
1282 if (ret < 0) {
1283 error("checking mount status of %s failed: %d", dev, ret);
1284 return -1;
1285 }
1286
1287 /* Open the super_block at the default location
1288 * and as read-only.
1289 */
1290 root = open_ctree(dev, 0, 0);
1291 if(!root)
1292 return -1;
1293
1294 __strncpy_null(label, root->fs_info->super_copy->label,
1295 BTRFS_LABEL_SIZE - 1);
1296
1297 /* Now we close it since we are done. */
1298 close_ctree(root);
1299 return 0;
1300 }
1301
1302 /*
1303 * If a partition is mounted, try to get the filesystem label via its
1304 * mounted path rather than device. Return the corresponding error
1305 * the user specified the device path.
1306 */
1307 int get_label_mounted(const char *mount_path, char *labelp)
1308 {
1309 char label[BTRFS_LABEL_SIZE];
1310 int fd;
1311 int ret;
1312
1313 fd = open(mount_path, O_RDONLY | O_NOATIME);
1314 if (fd < 0) {
1315 error("unable to access %s: %s", mount_path, strerror(errno));
1316 return -1;
1317 }
1318
1319 memset(label, '\0', sizeof(label));
1320 ret = ioctl(fd, BTRFS_IOC_GET_FSLABEL, label);
1321 if (ret < 0) {
1322 if (errno != ENOTTY)
1323 error("unable to get label of %s: %s", mount_path,
1324 strerror(errno));
1325 ret = -errno;
1326 close(fd);
1327 return ret;
1328 }
1329
1330 __strncpy_null(labelp, label, BTRFS_LABEL_SIZE - 1);
1331 close(fd);
1332 return 0;
1333 }
1334
1335 int get_label(const char *btrfs_dev, char *label)
1336 {
1337 int ret;
1338
1339 ret = is_existing_blk_or_reg_file(btrfs_dev);
1340 if (!ret)
1341 ret = get_label_mounted(btrfs_dev, label);
1342 else if (ret > 0)
1343 ret = get_label_unmounted(btrfs_dev, label);
1344
1345 return ret;
1346 }
1347
1348 int set_label(const char *btrfs_dev, const char *label)
1349 {
1350 int ret;
1351
1352 if (check_label(label))
1353 return -1;
1354
1355 ret = is_existing_blk_or_reg_file(btrfs_dev);
1356 if (!ret)
1357 ret = set_label_mounted(btrfs_dev, label);
1358 else if (ret > 0)
1359 ret = set_label_unmounted(btrfs_dev, label);
1360
1361 return ret;
1362 }
1363
1364 /*
1365 * A not-so-good version fls64. No fascinating optimization since
1366 * no one except parse_size use it
1367 */
1368 static int fls64(u64 x)
1369 {
1370 int i;
1371
1372 for (i = 0; i <64; i++)
1373 if (x << i & (1ULL << 63))
1374 return 64 - i;
1375 return 64 - i;
1376 }
1377
1378 u64 parse_size(char *s)
1379 {
1380 char c;
1381 char *endptr;
1382 u64 mult = 1;
1383 u64 ret;
1384
1385 if (!s) {
1386 error("size value is empty");
1387 exit(1);
1388 }
1389 if (s[0] == '-') {
1390 error("size value '%s' is less equal than 0", s);
1391 exit(1);
1392 }
1393 ret = strtoull(s, &endptr, 10);
1394 if (endptr == s) {
1395 error("size value '%s' is invalid", s);
1396 exit(1);
1397 }
1398 if (endptr[0] && endptr[1]) {
1399 error("illegal suffix contains character '%c' in wrong position",
1400 endptr[1]);
1401 exit(1);
1402 }
1403 /*
1404 * strtoll returns LLONG_MAX when overflow, if this happens,
1405 * need to call strtoull to get the real size
1406 */
1407 if (errno == ERANGE && ret == ULLONG_MAX) {
1408 error("size value '%s' is too large for u64", s);
1409 exit(1);
1410 }
1411 if (endptr[0]) {
1412 c = tolower(endptr[0]);
1413 switch (c) {
1414 case 'e':
1415 mult *= 1024;
1416 /* fallthrough */
1417 case 'p':
1418 mult *= 1024;
1419 /* fallthrough */
1420 case 't':
1421 mult *= 1024;
1422 /* fallthrough */
1423 case 'g':
1424 mult *= 1024;
1425 /* fallthrough */
1426 case 'm':
1427 mult *= 1024;
1428 /* fallthrough */
1429 case 'k':
1430 mult *= 1024;
1431 /* fallthrough */
1432 case 'b':
1433 break;
1434 default:
1435 error("unknown size descriptor '%c'", c);
1436 exit(1);
1437 }
1438 }
1439 /* Check whether ret * mult overflow */
1440 if (fls64(ret) + fls64(mult) - 1 > 64) {
1441 error("size value '%s' is too large for u64", s);
1442 exit(1);
1443 }
1444 ret *= mult;
1445 return ret;
1446 }
1447
1448 u64 parse_qgroupid(const char *p)
1449 {
1450 char *s = strchr(p, '/');
1451 const char *ptr_src_end = p + strlen(p);
1452 char *ptr_parse_end = NULL;
1453 u64 level;
1454 u64 id;
1455 int fd;
1456 int ret = 0;
1457
1458 if (p[0] == '/')
1459 goto path;
1460
1461 /* Numeric format like '0/257' is the primary case */
1462 if (!s) {
1463 id = strtoull(p, &ptr_parse_end, 10);
1464 if (ptr_parse_end != ptr_src_end)
1465 goto path;
1466 return id;
1467 }
1468 level = strtoull(p, &ptr_parse_end, 10);
1469 if (ptr_parse_end != s)
1470 goto path;
1471
1472 id = strtoull(s + 1, &ptr_parse_end, 10);
1473 if (ptr_parse_end != ptr_src_end)
1474 goto path;
1475
1476 return (level << BTRFS_QGROUP_LEVEL_SHIFT) | id;
1477
1478 path:
1479 /* Path format like subv at 'my_subvol' is the fallback case */
1480 ret = test_issubvolume(p);
1481 if (ret < 0 || !ret)
1482 goto err;
1483 fd = open(p, O_RDONLY);
1484 if (fd < 0)
1485 goto err;
1486 ret = lookup_path_rootid(fd, &id);
1487 if (ret)
1488 error("failed to lookup root id: %s", strerror(-ret));
1489 close(fd);
1490 if (ret < 0)
1491 goto err;
1492 return id;
1493
1494 err:
1495 error("invalid qgroupid or subvolume path: %s", p);
1496 exit(-1);
1497 }
1498
1499 int open_file_or_dir3(const char *fname, DIR **dirstream, int open_flags)
1500 {
1501 int ret;
1502 struct stat st;
1503 int fd;
1504
1505 ret = stat(fname, &st);
1506 if (ret < 0) {
1507 return -1;
1508 }
1509 if (S_ISDIR(st.st_mode)) {
1510 *dirstream = opendir(fname);
1511 if (!*dirstream)
1512 return -1;
1513 fd = dirfd(*dirstream);
1514 } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
1515 fd = open(fname, open_flags);
1516 } else {
1517 /*
1518 * we set this on purpose, in case the caller output
1519 * strerror(errno) as success
1520 */
1521 errno = EINVAL;
1522 return -1;
1523 }
1524 if (fd < 0) {
1525 fd = -1;
1526 if (*dirstream) {
1527 closedir(*dirstream);
1528 *dirstream = NULL;
1529 }
1530 }
1531 return fd;
1532 }
1533
1534 int open_file_or_dir(const char *fname, DIR **dirstream)
1535 {
1536 return open_file_or_dir3(fname, dirstream, O_RDWR);
1537 }
1538
1539 void close_file_or_dir(int fd, DIR *dirstream)
1540 {
1541 if (dirstream)
1542 closedir(dirstream);
1543 else if (fd >= 0)
1544 close(fd);
1545 }
1546
1547 int get_device_info(int fd, u64 devid,
1548 struct btrfs_ioctl_dev_info_args *di_args)
1549 {
1550 int ret;
1551
1552 di_args->devid = devid;
1553 memset(&di_args->uuid, '\0', sizeof(di_args->uuid));
1554
1555 ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args);
1556 return ret < 0 ? -errno : 0;
1557 }
1558
1559 static u64 find_max_device_id(struct btrfs_ioctl_search_args *search_args,
1560 int nr_items)
1561 {
1562 struct btrfs_dev_item *dev_item;
1563 char *buf = search_args->buf;
1564
1565 buf += (nr_items - 1) * (sizeof(struct btrfs_ioctl_search_header)
1566 + sizeof(struct btrfs_dev_item));
1567 buf += sizeof(struct btrfs_ioctl_search_header);
1568
1569 dev_item = (struct btrfs_dev_item *)buf;
1570
1571 return btrfs_stack_device_id(dev_item);
1572 }
1573
1574 static int search_chunk_tree_for_fs_info(int fd,
1575 struct btrfs_ioctl_fs_info_args *fi_args)
1576 {
1577 int ret;
1578 int max_items;
1579 u64 start_devid = 1;
1580 struct btrfs_ioctl_search_args search_args;
1581 struct btrfs_ioctl_search_key *search_key = &search_args.key;
1582
1583 fi_args->num_devices = 0;
1584
1585 max_items = BTRFS_SEARCH_ARGS_BUFSIZE
1586 / (sizeof(struct btrfs_ioctl_search_header)
1587 + sizeof(struct btrfs_dev_item));
1588
1589 search_key->tree_id = BTRFS_CHUNK_TREE_OBJECTID;
1590 search_key->min_objectid = BTRFS_DEV_ITEMS_OBJECTID;
1591 search_key->max_objectid = BTRFS_DEV_ITEMS_OBJECTID;
1592 search_key->min_type = BTRFS_DEV_ITEM_KEY;
1593 search_key->max_type = BTRFS_DEV_ITEM_KEY;
1594 search_key->min_transid = 0;
1595 search_key->max_transid = (u64)-1;
1596 search_key->nr_items = max_items;
1597 search_key->max_offset = (u64)-1;
1598
1599 again:
1600 search_key->min_offset = start_devid;
1601
1602 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_args);
1603 if (ret < 0)
1604 return -errno;
1605
1606 fi_args->num_devices += (u64)search_key->nr_items;
1607
1608 if (search_key->nr_items == max_items) {
1609 start_devid = find_max_device_id(&search_args,
1610 search_key->nr_items) + 1;
1611 goto again;
1612 }
1613
1614 /* get the lastest max_id to stay consistent with the num_devices */
1615 if (search_key->nr_items == 0)
1616 /*
1617 * last tree_search returns an empty buf, use the devid of
1618 * the last dev_item of the previous tree_search
1619 */
1620 fi_args->max_id = start_devid - 1;
1621 else
1622 fi_args->max_id = find_max_device_id(&search_args,
1623 search_key->nr_items);
1624
1625 return 0;
1626 }
1627
1628 /*
1629 * For a given path, fill in the ioctl fs_ and info_ args.
1630 * If the path is a btrfs mountpoint, fill info for all devices.
1631 * If the path is a btrfs device, fill in only that device.
1632 *
1633 * The path provided must be either on a mounted btrfs fs,
1634 * or be a mounted btrfs device.
1635 *
1636 * Returns 0 on success, or a negative errno.
1637 */
1638 int get_fs_info(const char *path, struct btrfs_ioctl_fs_info_args *fi_args,
1639 struct btrfs_ioctl_dev_info_args **di_ret)
1640 {
1641 int fd = -1;
1642 int ret = 0;
1643 int ndevs = 0;
1644 u64 last_devid = 0;
1645 int replacing = 0;
1646 struct btrfs_fs_devices *fs_devices_mnt = NULL;
1647 struct btrfs_ioctl_dev_info_args *di_args;
1648 struct btrfs_ioctl_dev_info_args tmp;
1649 char mp[PATH_MAX];
1650 DIR *dirstream = NULL;
1651
1652 memset(fi_args, 0, sizeof(*fi_args));
1653
1654 if (is_block_device(path) == 1) {
1655 struct btrfs_super_block *disk_super;
1656 char buf[BTRFS_SUPER_INFO_SIZE];
1657
1658 /* Ensure it's mounted, then set path to the mountpoint */
1659 fd = open(path, O_RDONLY);
1660 if (fd < 0) {
1661 ret = -errno;
1662 error("cannot open %s: %s", path, strerror(errno));
1663 goto out;
1664 }
1665 ret = check_mounted_where(fd, path, mp, sizeof(mp),
1666 &fs_devices_mnt);
1667 if (!ret) {
1668 ret = -EINVAL;
1669 goto out;
1670 }
1671 if (ret < 0)
1672 goto out;
1673 path = mp;
1674 /* Only fill in this one device */
1675 fi_args->num_devices = 1;
1676
1677 disk_super = (struct btrfs_super_block *)buf;
1678 ret = btrfs_read_dev_super(fd, disk_super,
1679 BTRFS_SUPER_INFO_OFFSET, 0);
1680 if (ret < 0) {
1681 ret = -EIO;
1682 goto out;
1683 }
1684 last_devid = btrfs_stack_device_id(&disk_super->dev_item);
1685 fi_args->max_id = last_devid;
1686
1687 memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE);
1688 close(fd);
1689 }
1690
1691 /* at this point path must not be for a block device */
1692 fd = open_file_or_dir(path, &dirstream);
1693 if (fd < 0) {
1694 ret = -errno;
1695 goto out;
1696 }
1697
1698 /* fill in fi_args if not just a single device */
1699 if (fi_args->num_devices != 1) {
1700 ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
1701 if (ret < 0) {
1702 ret = -errno;
1703 goto out;
1704 }
1705
1706 /*
1707 * The fs_args->num_devices does not include seed devices
1708 */
1709 ret = search_chunk_tree_for_fs_info(fd, fi_args);
1710 if (ret)
1711 goto out;
1712
1713 /*
1714 * search_chunk_tree_for_fs_info() will lacks the devid 0
1715 * so manual probe for it here.
1716 */
1717 ret = get_device_info(fd, 0, &tmp);
1718 if (!ret) {
1719 fi_args->num_devices++;
1720 ndevs++;
1721 replacing = 1;
1722 if (last_devid == 0)
1723 last_devid++;
1724 }
1725 }
1726
1727 if (!fi_args->num_devices)
1728 goto out;
1729
1730 di_args = *di_ret = malloc((fi_args->num_devices) * sizeof(*di_args));
1731 if (!di_args) {
1732 ret = -errno;
1733 goto out;
1734 }
1735
1736 if (replacing)
1737 memcpy(di_args, &tmp, sizeof(tmp));
1738 for (; last_devid <= fi_args->max_id; last_devid++) {
1739 ret = get_device_info(fd, last_devid, &di_args[ndevs]);
1740 if (ret == -ENODEV)
1741 continue;
1742 if (ret)
1743 goto out;
1744 ndevs++;
1745 }
1746
1747 /*
1748 * only when the only dev we wanted to find is not there then
1749 * let any error be returned
1750 */
1751 if (fi_args->num_devices != 1) {
1752 BUG_ON(ndevs == 0);
1753 ret = 0;
1754 }
1755
1756 out:
1757 close_file_or_dir(fd, dirstream);
1758 return ret;
1759 }
1760
1761 static int group_profile_devs_min(u64 flag)
1762 {
1763 switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
1764 case 0: /* single */
1765 case BTRFS_BLOCK_GROUP_DUP:
1766 return 1;
1767 case BTRFS_BLOCK_GROUP_RAID0:
1768 case BTRFS_BLOCK_GROUP_RAID1:
1769 case BTRFS_BLOCK_GROUP_RAID5:
1770 return 2;
1771 case BTRFS_BLOCK_GROUP_RAID6:
1772 return 3;
1773 case BTRFS_BLOCK_GROUP_RAID10:
1774 return 4;
1775 default:
1776 return -1;
1777 }
1778 }
1779
1780 int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
1781 u64 dev_cnt, int mixed, int ssd)
1782 {
1783 u64 allowed = 0;
1784 u64 profile = metadata_profile | data_profile;
1785
1786 switch (dev_cnt) {
1787 default:
1788 case 4:
1789 allowed |= BTRFS_BLOCK_GROUP_RAID10;
1790 case 3:
1791 allowed |= BTRFS_BLOCK_GROUP_RAID6;
1792 case 2:
1793 allowed |= BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1794 BTRFS_BLOCK_GROUP_RAID5;
1795 case 1:
1796 allowed |= BTRFS_BLOCK_GROUP_DUP;
1797 }
1798
1799 if (dev_cnt > 1 && profile & BTRFS_BLOCK_GROUP_DUP) {
1800 warning("DUP is not recommended on filesystem with multiple devices");
1801 }
1802 if (metadata_profile & ~allowed) {
1803 fprintf(stderr,
1804 "ERROR: unable to create FS with metadata profile %s "
1805 "(have %llu devices but %d devices are required)\n",
1806 btrfs_group_profile_str(metadata_profile), dev_cnt,
1807 group_profile_devs_min(metadata_profile));
1808 return 1;
1809 }
1810 if (data_profile & ~allowed) {
1811 fprintf(stderr,
1812 "ERROR: unable to create FS with data profile %s "
1813 "(have %llu devices but %d devices are required)\n",
1814 btrfs_group_profile_str(data_profile), dev_cnt,
1815 group_profile_devs_min(data_profile));
1816 return 1;
1817 }
1818
1819 if (dev_cnt == 3 && profile & BTRFS_BLOCK_GROUP_RAID6) {
1820 warning("RAID6 is not recommended on filesystem with 3 devices only");
1821 }
1822 if (dev_cnt == 2 && profile & BTRFS_BLOCK_GROUP_RAID5) {
1823 warning("RAID5 is not recommended on filesystem with 2 devices only");
1824 }
1825 warning_on(!mixed && (data_profile & BTRFS_BLOCK_GROUP_DUP) && ssd,
1826 "DUP may not actually lead to 2 copies on the device, see manual page");
1827
1828 return 0;
1829 }
1830
1831 int group_profile_max_safe_loss(u64 flags)
1832 {
1833 switch (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
1834 case 0: /* single */
1835 case BTRFS_BLOCK_GROUP_DUP:
1836 case BTRFS_BLOCK_GROUP_RAID0:
1837 return 0;
1838 case BTRFS_BLOCK_GROUP_RAID1:
1839 case BTRFS_BLOCK_GROUP_RAID5:
1840 case BTRFS_BLOCK_GROUP_RAID10:
1841 return 1;
1842 case BTRFS_BLOCK_GROUP_RAID6:
1843 return 2;
1844 default:
1845 return -1;
1846 }
1847 }
1848
1849 int btrfs_scan_devices(void)
1850 {
1851 int fd = -1;
1852 int ret;
1853 u64 num_devices;
1854 struct btrfs_fs_devices *tmp_devices;
1855 blkid_dev_iterate iter = NULL;
1856 blkid_dev dev = NULL;
1857 blkid_cache cache = NULL;
1858 char path[PATH_MAX];
1859
1860 if (btrfs_scan_done)
1861 return 0;
1862
1863 if (blkid_get_cache(&cache, NULL) < 0) {
1864 error("blkid cache get failed");
1865 return 1;
1866 }
1867 blkid_probe_all(cache);
1868 iter = blkid_dev_iterate_begin(cache);
1869 blkid_dev_set_search(iter, "TYPE", "btrfs");
1870 while (blkid_dev_next(iter, &dev) == 0) {
1871 dev = blkid_verify(cache, dev);
1872 if (!dev)
1873 continue;
1874 /* if we are here its definitely a btrfs disk*/
1875 strncpy_null(path, blkid_dev_devname(dev));
1876
1877 fd = open(path, O_RDONLY);
1878 if (fd < 0) {
1879 error("cannot open %s: %s", path, strerror(errno));
1880 continue;
1881 }
1882 ret = btrfs_scan_one_device(fd, path, &tmp_devices,
1883 &num_devices, BTRFS_SUPER_INFO_OFFSET,
1884 SBREAD_DEFAULT);
1885 if (ret) {
1886 error("cannot scan %s: %s", path, strerror(-ret));
1887 close (fd);
1888 continue;
1889 }
1890
1891 close(fd);
1892 }
1893 blkid_dev_iterate_end(iter);
1894 blkid_put_cache(cache);
1895
1896 btrfs_scan_done = 1;
1897
1898 return 0;
1899 }
1900
1901 /*
1902 * This reads a line from the stdin and only returns non-zero if the
1903 * first whitespace delimited token is a case insensitive match with yes
1904 * or y.
1905 */
1906 int ask_user(const char *question)
1907 {
1908 char buf[30] = {0,};
1909 char *saveptr = NULL;
1910 char *answer;
1911
1912 printf("%s [y/N]: ", question);
1913
1914 return fgets(buf, sizeof(buf) - 1, stdin) &&
1915 (answer = strtok_r(buf, " \t\n\r", &saveptr)) &&
1916 (!strcasecmp(answer, "yes") || !strcasecmp(answer, "y"));
1917 }
1918
1919 /*
1920 * return 0 if a btrfs mount point is found
1921 * return 1 if a mount point is found but not btrfs
1922 * return <0 if something goes wrong
1923 */
1924 int find_mount_root(const char *path, char **mount_root)
1925 {
1926 FILE *mnttab;
1927 int fd;
1928 struct mntent *ent;
1929 int len;
1930 int ret;
1931 int not_btrfs = 1;
1932 int longest_matchlen = 0;
1933 char *longest_match = NULL;
1934
1935 fd = open(path, O_RDONLY | O_NOATIME);
1936 if (fd < 0)
1937 return -errno;
1938 close(fd);
1939
1940 mnttab = setmntent("/proc/self/mounts", "r");
1941 if (!mnttab)
1942 return -errno;
1943
1944 while ((ent = getmntent(mnttab))) {
1945 len = strlen(ent->mnt_dir);
1946 if (strncmp(ent->mnt_dir, path, len) == 0) {
1947 /* match found and use the latest match */
1948 if (longest_matchlen <= len) {
1949 free(longest_match);
1950 longest_matchlen = len;
1951 longest_match = strdup(ent->mnt_dir);
1952 not_btrfs = strcmp(ent->mnt_type, "btrfs");
1953 }
1954 }
1955 }
1956 endmntent(mnttab);
1957
1958 if (!longest_match)
1959 return -ENOENT;
1960 if (not_btrfs) {
1961 free(longest_match);
1962 return 1;
1963 }
1964
1965 ret = 0;
1966 *mount_root = realpath(longest_match, NULL);
1967 if (!*mount_root)
1968 ret = -errno;
1969
1970 free(longest_match);
1971 return ret;
1972 }
1973
1974 /*
1975 * Test if path is a directory
1976 * Returns:
1977 * 0 - path exists but it is not a directory
1978 * 1 - path exists and it is a directory
1979 * < 0 - error
1980 */
1981 int test_isdir(const char *path)
1982 {
1983 struct stat st;
1984 int ret;
1985
1986 ret = stat(path, &st);
1987 if (ret < 0)
1988 return -errno;
1989
1990 return !!S_ISDIR(st.st_mode);
1991 }
1992
1993 void units_set_mode(unsigned *units, unsigned mode)
1994 {
1995 unsigned base = *units & UNITS_MODE_MASK;
1996
1997 *units = base | mode;
1998 }
1999
2000 void units_set_base(unsigned *units, unsigned base)
2001 {
2002 unsigned mode = *units & ~UNITS_MODE_MASK;
2003
2004 *units = base | mode;
2005 }
2006
2007 int find_next_key(struct btrfs_path *path, struct btrfs_key *key)
2008 {
2009 int level;
2010
2011 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2012 if (!path->nodes[level])
2013 break;
2014 if (path->slots[level] + 1 >=
2015 btrfs_header_nritems(path->nodes[level]))
2016 continue;
2017 if (level == 0)
2018 btrfs_item_key_to_cpu(path->nodes[level], key,
2019 path->slots[level] + 1);
2020 else
2021 btrfs_node_key_to_cpu(path->nodes[level], key,
2022 path->slots[level] + 1);
2023 return 0;
2024 }
2025 return 1;
2026 }
2027
2028 const char* btrfs_group_type_str(u64 flag)
2029 {
2030 u64 mask = BTRFS_BLOCK_GROUP_TYPE_MASK |
2031 BTRFS_SPACE_INFO_GLOBAL_RSV;
2032
2033 switch (flag & mask) {
2034 case BTRFS_BLOCK_GROUP_DATA:
2035 return "Data";
2036 case BTRFS_BLOCK_GROUP_SYSTEM:
2037 return "System";
2038 case BTRFS_BLOCK_GROUP_METADATA:
2039 return "Metadata";
2040 case BTRFS_BLOCK_GROUP_DATA|BTRFS_BLOCK_GROUP_METADATA:
2041 return "Data+Metadata";
2042 case BTRFS_SPACE_INFO_GLOBAL_RSV:
2043 return "GlobalReserve";
2044 default:
2045 return "unknown";
2046 }
2047 }
2048
2049 const char* btrfs_group_profile_str(u64 flag)
2050 {
2051 switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
2052 case 0:
2053 return "single";
2054 case BTRFS_BLOCK_GROUP_RAID0:
2055 return "RAID0";
2056 case BTRFS_BLOCK_GROUP_RAID1:
2057 return "RAID1";
2058 case BTRFS_BLOCK_GROUP_RAID5:
2059 return "RAID5";
2060 case BTRFS_BLOCK_GROUP_RAID6:
2061 return "RAID6";
2062 case BTRFS_BLOCK_GROUP_DUP:
2063 return "DUP";
2064 case BTRFS_BLOCK_GROUP_RAID10:
2065 return "RAID10";
2066 default:
2067 return "unknown";
2068 }
2069 }
2070
2071 u64 disk_size(const char *path)
2072 {
2073 struct statfs sfs;
2074
2075 if (statfs(path, &sfs) < 0)
2076 return 0;
2077 else
2078 return sfs.f_bsize * sfs.f_blocks;
2079 }
2080
2081 u64 get_partition_size(const char *dev)
2082 {
2083 u64 result;
2084 int fd = open(dev, O_RDONLY);
2085
2086 if (fd < 0)
2087 return 0;
2088 if (ioctl(fd, BLKGETSIZE64, &result) < 0) {
2089 close(fd);
2090 return 0;
2091 }
2092 close(fd);
2093
2094 return result;
2095 }
2096
2097 /*
2098 * Check if the BTRFS_IOC_TREE_SEARCH_V2 ioctl is supported on a given
2099 * filesystem, opened at fd
2100 */
2101 int btrfs_tree_search2_ioctl_supported(int fd)
2102 {
2103 struct btrfs_ioctl_search_args_v2 *args2;
2104 struct btrfs_ioctl_search_key *sk;
2105 int args2_size = 1024;
2106 char args2_buf[args2_size];
2107 int ret;
2108
2109 args2 = (struct btrfs_ioctl_search_args_v2 *)args2_buf;
2110 sk = &(args2->key);
2111
2112 /*
2113 * Search for the extent tree item in the root tree.
2114 */
2115 sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
2116 sk->min_objectid = BTRFS_EXTENT_TREE_OBJECTID;
2117 sk->max_objectid = BTRFS_EXTENT_TREE_OBJECTID;
2118 sk->min_type = BTRFS_ROOT_ITEM_KEY;
2119 sk->max_type = BTRFS_ROOT_ITEM_KEY;
2120 sk->min_offset = 0;
2121 sk->max_offset = (u64)-1;
2122 sk->min_transid = 0;
2123 sk->max_transid = (u64)-1;
2124 sk->nr_items = 1;
2125 args2->buf_size = args2_size - sizeof(struct btrfs_ioctl_search_args_v2);
2126 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH_V2, args2);
2127 if (ret == -EOPNOTSUPP)
2128 return 0;
2129 else if (ret == 0)
2130 return 1;
2131 return ret;
2132 }
2133
2134 int btrfs_check_nodesize(u32 nodesize, u32 sectorsize, u64 features)
2135 {
2136 if (nodesize < sectorsize) {
2137 error("illegal nodesize %u (smaller than %u)",
2138 nodesize, sectorsize);
2139 return -1;
2140 } else if (nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2141 error("illegal nodesize %u (larger than %u)",
2142 nodesize, BTRFS_MAX_METADATA_BLOCKSIZE);
2143 return -1;
2144 } else if (nodesize & (sectorsize - 1)) {
2145 error("illegal nodesize %u (not aligned to %u)",
2146 nodesize, sectorsize);
2147 return -1;
2148 } else if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS &&
2149 nodesize != sectorsize) {
2150 error("illegal nodesize %u (not equal to %u for mixed block group)",
2151 nodesize, sectorsize);
2152 return -1;
2153 }
2154 return 0;
2155 }
2156
2157 /*
2158 * Copy a path argument from SRC to DEST and check the SRC length if it's at
2159 * most PATH_MAX and fits into DEST. DESTLEN is supposed to be exact size of
2160 * the buffer.
2161 * The destination buffer is zero terminated.
2162 * Return < 0 for error, 0 otherwise.
2163 */
2164 int arg_copy_path(char *dest, const char *src, int destlen)
2165 {
2166 size_t len = strlen(src);
2167
2168 if (len >= PATH_MAX || len >= destlen)
2169 return -ENAMETOOLONG;
2170
2171 __strncpy_null(dest, src, destlen);
2172
2173 return 0;
2174 }
2175
2176 unsigned int get_unit_mode_from_arg(int *argc, char *argv[], int df_mode)
2177 {
2178 unsigned int unit_mode = UNITS_DEFAULT;
2179 int arg_i;
2180 int arg_end;
2181
2182 for (arg_i = 0; arg_i < *argc; arg_i++) {
2183 if (!strcmp(argv[arg_i], "--"))
2184 break;
2185
2186 if (!strcmp(argv[arg_i], "--raw")) {
2187 unit_mode = UNITS_RAW;
2188 argv[arg_i] = NULL;
2189 continue;
2190 }
2191 if (!strcmp(argv[arg_i], "--human-readable")) {
2192 unit_mode = UNITS_HUMAN_BINARY;
2193 argv[arg_i] = NULL;
2194 continue;
2195 }
2196
2197 if (!strcmp(argv[arg_i], "--iec")) {
2198 units_set_mode(&unit_mode, UNITS_BINARY);
2199 argv[arg_i] = NULL;
2200 continue;
2201 }
2202 if (!strcmp(argv[arg_i], "--si")) {
2203 units_set_mode(&unit_mode, UNITS_DECIMAL);
2204 argv[arg_i] = NULL;
2205 continue;
2206 }
2207
2208 if (!strcmp(argv[arg_i], "--kbytes")) {
2209 units_set_base(&unit_mode, UNITS_KBYTES);
2210 argv[arg_i] = NULL;
2211 continue;
2212 }
2213 if (!strcmp(argv[arg_i], "--mbytes")) {
2214 units_set_base(&unit_mode, UNITS_MBYTES);
2215 argv[arg_i] = NULL;
2216 continue;
2217 }
2218 if (!strcmp(argv[arg_i], "--gbytes")) {
2219 units_set_base(&unit_mode, UNITS_GBYTES);
2220 argv[arg_i] = NULL;
2221 continue;
2222 }
2223 if (!strcmp(argv[arg_i], "--tbytes")) {
2224 units_set_base(&unit_mode, UNITS_TBYTES);
2225 argv[arg_i] = NULL;
2226 continue;
2227 }
2228
2229 if (!df_mode)
2230 continue;
2231
2232 if (!strcmp(argv[arg_i], "-b")) {
2233 unit_mode = UNITS_RAW;
2234 argv[arg_i] = NULL;
2235 continue;
2236 }
2237 if (!strcmp(argv[arg_i], "-h")) {
2238 unit_mode = UNITS_HUMAN_BINARY;
2239 argv[arg_i] = NULL;
2240 continue;
2241 }
2242 if (!strcmp(argv[arg_i], "-H")) {
2243 unit_mode = UNITS_HUMAN_DECIMAL;
2244 argv[arg_i] = NULL;
2245 continue;
2246 }
2247 if (!strcmp(argv[arg_i], "-k")) {
2248 units_set_base(&unit_mode, UNITS_KBYTES);
2249 argv[arg_i] = NULL;
2250 continue;
2251 }
2252 if (!strcmp(argv[arg_i], "-m")) {
2253 units_set_base(&unit_mode, UNITS_MBYTES);
2254 argv[arg_i] = NULL;
2255 continue;
2256 }
2257 if (!strcmp(argv[arg_i], "-g")) {
2258 units_set_base(&unit_mode, UNITS_GBYTES);
2259 argv[arg_i] = NULL;
2260 continue;
2261 }
2262 if (!strcmp(argv[arg_i], "-t")) {
2263 units_set_base(&unit_mode, UNITS_TBYTES);
2264 argv[arg_i] = NULL;
2265 continue;
2266 }
2267 }
2268
2269 for (arg_i = 0, arg_end = 0; arg_i < *argc; arg_i++) {
2270 if (!argv[arg_i])
2271 continue;
2272 argv[arg_end] = argv[arg_i];
2273 arg_end++;
2274 }
2275
2276 *argc = arg_end;
2277
2278 return unit_mode;
2279 }
2280
2281 u64 div_factor(u64 num, int factor)
2282 {
2283 if (factor == 10)
2284 return num;
2285 num *= factor;
2286 num /= 10;
2287 return num;
2288 }
2289 /*
2290 * Get the length of the string converted from a u64 number.
2291 *
2292 * Result is equal to log10(num) + 1, but without the use of math library.
2293 */
2294 int count_digits(u64 num)
2295 {
2296 int ret = 0;
2297
2298 if (num == 0)
2299 return 1;
2300 while (num > 0) {
2301 ret++;
2302 num /= 10;
2303 }
2304 return ret;
2305 }
2306
2307 int string_is_numerical(const char *str)
2308 {
2309 if (!str)
2310 return 0;
2311 if (!(*str >= '0' && *str <= '9'))
2312 return 0;
2313 while (*str >= '0' && *str <= '9')
2314 str++;
2315 if (*str != '\0')
2316 return 0;
2317 return 1;
2318 }
2319
2320 int prefixcmp(const char *str, const char *prefix)
2321 {
2322 for (; ; str++, prefix++)
2323 if (!*prefix)
2324 return 0;
2325 else if (*str != *prefix)
2326 return (unsigned char)*prefix - (unsigned char)*str;
2327 }
2328
2329 /* Subvolume helper functions */
2330 /*
2331 * test if name is a correct subvolume name
2332 * this function return
2333 * 0-> name is not a correct subvolume name
2334 * 1-> name is a correct subvolume name
2335 */
2336 int test_issubvolname(const char *name)
2337 {
2338 return name[0] != '\0' && !strchr(name, '/') &&
2339 strcmp(name, ".") && strcmp(name, "..");
2340 }
2341
2342 /*
2343 * Test if path is a subvolume
2344 * Returns:
2345 * 0 - path exists but it is not a subvolume
2346 * 1 - path exists and it is a subvolume
2347 * < 0 - error
2348 */
2349 int test_issubvolume(const char *path)
2350 {
2351 struct stat st;
2352 struct statfs stfs;
2353 int res;
2354
2355 res = stat(path, &st);
2356 if (res < 0)
2357 return -errno;
2358
2359 if (st.st_ino != BTRFS_FIRST_FREE_OBJECTID || !S_ISDIR(st.st_mode))
2360 return 0;
2361
2362 res = statfs(path, &stfs);
2363 if (res < 0)
2364 return -errno;
2365
2366 return (int)stfs.f_type == BTRFS_SUPER_MAGIC;
2367 }
2368
2369 const char *subvol_strip_mountpoint(const char *mnt, const char *full_path)
2370 {
2371 int len = strlen(mnt);
2372 if (!len)
2373 return full_path;
2374
2375 if (mnt[len - 1] != '/')
2376 len += 1;
2377
2378 return full_path + len;
2379 }
2380
2381 /*
2382 * Returns
2383 * <0: Std error
2384 * 0: All fine
2385 * 1: Error; and error info printed to the terminal. Fixme.
2386 * 2: If the fullpath is root tree instead of subvol tree
2387 */
2388 int get_subvol_info(const char *fullpath, struct root_info *get_ri)
2389 {
2390 u64 sv_id;
2391 int ret = 1;
2392 int fd = -1;
2393 int mntfd = -1;
2394 char *mnt = NULL;
2395 const char *svpath = NULL;
2396 DIR *dirstream1 = NULL;
2397 DIR *dirstream2 = NULL;
2398
2399 ret = test_issubvolume(fullpath);
2400 if (ret < 0)
2401 return ret;
2402 if (!ret) {
2403 error("not a subvolume: %s", fullpath);
2404 return 1;
2405 }
2406
2407 ret = find_mount_root(fullpath, &mnt);
2408 if (ret < 0)
2409 return ret;
2410 if (ret > 0) {
2411 error("%s doesn't belong to btrfs mount point", fullpath);
2412 return 1;
2413 }
2414 ret = 1;
2415 svpath = subvol_strip_mountpoint(mnt, fullpath);
2416
2417 fd = btrfs_open_dir(fullpath, &dirstream1, 1);
2418 if (fd < 0)
2419 goto out;
2420
2421 ret = btrfs_list_get_path_rootid(fd, &sv_id);
2422 if (ret)
2423 goto out;
2424
2425 mntfd = btrfs_open_dir(mnt, &dirstream2, 1);
2426 if (mntfd < 0)
2427 goto out;
2428
2429 memset(get_ri, 0, sizeof(*get_ri));
2430 get_ri->root_id = sv_id;
2431
2432 if (sv_id == BTRFS_FS_TREE_OBJECTID)
2433 ret = btrfs_get_toplevel_subvol(mntfd, get_ri);
2434 else
2435 ret = btrfs_get_subvol(mntfd, get_ri);
2436 if (ret)
2437 error("can't find '%s': %d", svpath, ret);
2438
2439 out:
2440 close_file_or_dir(mntfd, dirstream2);
2441 close_file_or_dir(fd, dirstream1);
2442 free(mnt);
2443
2444 return ret;
2445 }
2446
2447 int get_subvol_info_by_rootid(const char *mnt, struct root_info *get_ri, u64 r_id)
2448 {
2449 int fd;
2450 int ret;
2451 DIR *dirstream = NULL;
2452
2453 fd = btrfs_open_dir(mnt, &dirstream, 1);
2454 if (fd < 0)
2455 return -EINVAL;
2456
2457 memset(get_ri, 0, sizeof(*get_ri));
2458 get_ri->root_id = r_id;
2459
2460 if (r_id == BTRFS_FS_TREE_OBJECTID)
2461 ret = btrfs_get_toplevel_subvol(fd, get_ri);
2462 else
2463 ret = btrfs_get_subvol(fd, get_ri);
2464
2465 if (ret)
2466 error("can't find rootid '%llu' on '%s': %d", r_id, mnt, ret);
2467
2468 close_file_or_dir(fd, dirstream);
2469
2470 return ret;
2471 }
2472
2473 int get_subvol_info_by_uuid(const char *mnt, struct root_info *get_ri, u8 *uuid_arg)
2474 {
2475 int fd;
2476 int ret;
2477 DIR *dirstream = NULL;
2478
2479 fd = btrfs_open_dir(mnt, &dirstream, 1);
2480 if (fd < 0)
2481 return -EINVAL;
2482
2483 memset(get_ri, 0, sizeof(*get_ri));
2484 uuid_copy(get_ri->uuid, uuid_arg);
2485
2486 ret = btrfs_get_subvol(fd, get_ri);
2487 if (ret) {
2488 char uuid_parsed[BTRFS_UUID_UNPARSED_SIZE];
2489 uuid_unparse(uuid_arg, uuid_parsed);
2490 error("can't find uuid '%s' on '%s': %d",
2491 uuid_parsed, mnt, ret);
2492 }
2493
2494 close_file_or_dir(fd, dirstream);
2495
2496 return ret;
2497 }
2498
2499 /* Set the seed manually */
2500 void init_rand_seed(u64 seed)
2501 {
2502 int i;
2503
2504 /* only use the last 48 bits */
2505 for (i = 0; i < 3; i++) {
2506 rand_seed[i] = (unsigned short)(seed ^ (unsigned short)(-1));
2507 seed >>= 16;
2508 }
2509 rand_seed_initlized = 1;
2510 }
2511
2512 static void __init_seed(void)
2513 {
2514 struct timeval tv;
2515 int ret;
2516 int fd;
2517
2518 if(rand_seed_initlized)
2519 return;
2520 /* Use urandom as primary seed source. */
2521 fd = open("/dev/urandom", O_RDONLY);
2522 if (fd >= 0) {
2523 ret = read(fd, rand_seed, sizeof(rand_seed));
2524 close(fd);
2525 if (ret < sizeof(rand_seed))
2526 goto fallback;
2527 } else {
2528 fallback:
2529 /* Use time and pid as fallback seed */
2530 warning("failed to read /dev/urandom, use time and pid as random seed");
2531 gettimeofday(&tv, 0);
2532 rand_seed[0] = getpid() ^ (tv.tv_sec & 0xFFFF);
2533 rand_seed[1] = getppid() ^ (tv.tv_usec & 0xFFFF);
2534 rand_seed[2] = (tv.tv_sec ^ tv.tv_usec) >> 16;
2535 }
2536 rand_seed_initlized = 1;
2537 }
2538
2539 u32 rand_u32(void)
2540 {
2541 __init_seed();
2542 /*
2543 * Don't use nrand48, its range is [0,2^31) The highest bit will alwasy
2544 * be 0. Use jrand48 to include the highest bit.
2545 */
2546 return (u32)jrand48(rand_seed);
2547 }
2548
2549 /* Return random number in range [0, upper) */
2550 unsigned int rand_range(unsigned int upper)
2551 {
2552 __init_seed();
2553 /*
2554 * Use the full 48bits to mod, which would be more uniformly
2555 * distributed
2556 */
2557 return (unsigned int)(jrand48(rand_seed) % upper);
2558 }
2559
2560 int rand_int(void)
2561 {
2562 return (int)(rand_u32());
2563 }
2564
2565 u64 rand_u64(void)
2566 {
2567 u64 ret = 0;
2568
2569 ret += rand_u32();
2570 ret <<= 32;
2571 ret += rand_u32();
2572 return ret;
2573 }
2574
2575 u16 rand_u16(void)
2576 {
2577 return (u16)(rand_u32());
2578 }
2579
2580 u8 rand_u8(void)
2581 {
2582 return (u8)(rand_u32());
2583 }
2584
2585 void btrfs_config_init(void)
2586 {
2587 }
(deprecated) Btrfs progs developments and patch integration