?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
btrfs-progs: doc: make all commands and subcommands bold
[btrfs-progs-unstable/devel.git] / utils.c
blobe130849c7bb5e9d6e4b4f9adf5d929cd14c33c76
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 #define _XOPEN_SOURCE 700
21 #define __USE_XOPEN2K8
22 #define __XOPEN2K8 /* due to an error in dirent.h, to get dirfd() */
23 #define _GNU_SOURCE /* O_NOATIME */
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/ioctl.h>
28 #include <sys/mount.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <uuid/uuid.h>
32 #include <fcntl.h>
33 #include <unistd.h>
34 #include <mntent.h>
35 #include <ctype.h>
36 #include <linux/loop.h>
37 #include <linux/major.h>
38 #include <linux/kdev_t.h>
39 #include <limits.h>
40 #include <blkid/blkid.h>
41 #include "kerncompat.h"
42 #include "radix-tree.h"
43 #include "ctree.h"
44 #include "disk-io.h"
45 #include "transaction.h"
46 #include "crc32c.h"
47 #include "utils.h"
48 #include "volumes.h"
49 #include "ioctl.h"
50
51 #ifndef BLKDISCARD
52 #define BLKDISCARD _IO(0x12,119)
53 #endif
54
55 /*
56 * Discard the given range in one go
57 */
58 static int discard_range(int fd, u64 start, u64 len)
59 {
60 u64 range[2] = { start, len };
61
62 if (ioctl(fd, BLKDISCARD, &range) < 0)
63 return errno;
64 return 0;
65 }
66
67 /*
68 * Discard blocks in the given range in 1G chunks, the process is interruptible
69 */
70 static int discard_blocks(int fd, u64 start, u64 len)
71 {
72 while (len > 0) {
73 /* 1G granularity */
74 u64 chunk_size = min_t(u64, len, 1*1024*1024*1024);
75 int ret;
76
77 ret = discard_range(fd, start, chunk_size);
78 if (ret)
79 return ret;
80 len -= chunk_size;
81 start += chunk_size;
82 }
83
84 return 0;
85 }
86
87 static u64 reference_root_table[] = {
88 [1] = BTRFS_ROOT_TREE_OBJECTID,
89 [2] = BTRFS_EXTENT_TREE_OBJECTID,
90 [3] = BTRFS_CHUNK_TREE_OBJECTID,
91 [4] = BTRFS_DEV_TREE_OBJECTID,
92 [5] = BTRFS_FS_TREE_OBJECTID,
93 [6] = BTRFS_CSUM_TREE_OBJECTID,
94 };
95
96 int make_btrfs(int fd, const char *device, const char *label,
97 u64 blocks[7], u64 num_bytes, u32 nodesize,
98 u32 leafsize, u32 sectorsize, u32 stripesize, u64 features)
99 {
100 struct btrfs_super_block super;
101 struct extent_buffer *buf;
102 struct btrfs_root_item root_item;
103 struct btrfs_disk_key disk_key;
104 struct btrfs_extent_item *extent_item;
105 struct btrfs_inode_item *inode_item;
106 struct btrfs_chunk *chunk;
107 struct btrfs_dev_item *dev_item;
108 struct btrfs_dev_extent *dev_extent;
109 u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
110 u8 *ptr;
111 int i;
112 int ret;
113 u32 itemoff;
114 u32 nritems = 0;
115 u64 first_free;
116 u64 ref_root;
117 u32 array_size;
118 u32 item_size;
119 int skinny_metadata = !!(features &
120 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
121
122 first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
123 first_free &= ~((u64)sectorsize - 1);
124
125 memset(&super, 0, sizeof(super));
126
127 num_bytes = (num_bytes / sectorsize) * sectorsize;
128 uuid_generate(super.fsid);
129 uuid_generate(super.dev_item.uuid);
130 uuid_generate(chunk_tree_uuid);
131
132 btrfs_set_super_bytenr(&super, blocks[0]);
133 btrfs_set_super_num_devices(&super, 1);
134 btrfs_set_super_magic(&super, BTRFS_MAGIC);
135 btrfs_set_super_generation(&super, 1);
136 btrfs_set_super_root(&super, blocks[1]);
137 btrfs_set_super_chunk_root(&super, blocks[3]);
138 btrfs_set_super_total_bytes(&super, num_bytes);
139 btrfs_set_super_bytes_used(&super, 6 * leafsize);
140 btrfs_set_super_sectorsize(&super, sectorsize);
141 btrfs_set_super_leafsize(&super, leafsize);
142 btrfs_set_super_nodesize(&super, nodesize);
143 btrfs_set_super_stripesize(&super, stripesize);
144 btrfs_set_super_csum_type(&super, BTRFS_CSUM_TYPE_CRC32);
145 btrfs_set_super_chunk_root_generation(&super, 1);
146 btrfs_set_super_cache_generation(&super, -1);
147 btrfs_set_super_incompat_flags(&super, features);
148 if (label)
149 strncpy(super.label, label, BTRFS_LABEL_SIZE - 1);
150
151 buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));
152
153 /* create the tree of root objects */
154 memset(buf->data, 0, leafsize);
155 buf->len = leafsize;
156 btrfs_set_header_bytenr(buf, blocks[1]);
157 btrfs_set_header_nritems(buf, 4);
158 btrfs_set_header_generation(buf, 1);
159 btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
160 btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
161 write_extent_buffer(buf, super.fsid, btrfs_header_fsid(),
162 BTRFS_FSID_SIZE);
163
164 write_extent_buffer(buf, chunk_tree_uuid,
165 btrfs_header_chunk_tree_uuid(buf),
166 BTRFS_UUID_SIZE);
167
168 /* create the items for the root tree */
169 memset(&root_item, 0, sizeof(root_item));
170 inode_item = &root_item.inode;
171 btrfs_set_stack_inode_generation(inode_item, 1);
172 btrfs_set_stack_inode_size(inode_item, 3);
173 btrfs_set_stack_inode_nlink(inode_item, 1);
174 btrfs_set_stack_inode_nbytes(inode_item, leafsize);
175 btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
176 btrfs_set_root_refs(&root_item, 1);
177 btrfs_set_root_used(&root_item, leafsize);
178 btrfs_set_root_generation(&root_item, 1);
179
180 memset(&disk_key, 0, sizeof(disk_key));
181 btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
182 btrfs_set_disk_key_offset(&disk_key, 0);
183 nritems = 0;
184
185 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
186 btrfs_set_root_bytenr(&root_item, blocks[2]);
187 btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
188 btrfs_set_item_key(buf, &disk_key, nritems);
189 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
190 btrfs_set_item_size(buf, btrfs_item_nr(nritems),
191 sizeof(root_item));
192 write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,
193 nritems), sizeof(root_item));
194 nritems++;
195
196 itemoff = itemoff - sizeof(root_item);
197 btrfs_set_root_bytenr(&root_item, blocks[4]);
198 btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);
199 btrfs_set_item_key(buf, &disk_key, nritems);
200 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
201 btrfs_set_item_size(buf, btrfs_item_nr(nritems),
202 sizeof(root_item));
203 write_extent_buffer(buf, &root_item,
204 btrfs_item_ptr_offset(buf, nritems),
205 sizeof(root_item));
206 nritems++;
207
208 itemoff = itemoff - sizeof(root_item);
209 btrfs_set_root_bytenr(&root_item, blocks[5]);
210 btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
211 btrfs_set_item_key(buf, &disk_key, nritems);
212 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
213 btrfs_set_item_size(buf, btrfs_item_nr(nritems),
214 sizeof(root_item));
215 write_extent_buffer(buf, &root_item,
216 btrfs_item_ptr_offset(buf, nritems),
217 sizeof(root_item));
218 nritems++;
219
220 itemoff = itemoff - sizeof(root_item);
221 btrfs_set_root_bytenr(&root_item, blocks[6]);
222 btrfs_set_disk_key_objectid(&disk_key, BTRFS_CSUM_TREE_OBJECTID);
223 btrfs_set_item_key(buf, &disk_key, nritems);
224 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
225 btrfs_set_item_size(buf, btrfs_item_nr(nritems),
226 sizeof(root_item));
227 write_extent_buffer(buf, &root_item,
228 btrfs_item_ptr_offset(buf, nritems),
229 sizeof(root_item));
230 nritems++;
231
232
233 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
234 ret = pwrite(fd, buf->data, leafsize, blocks[1]);
235 if (ret != leafsize) {
236 ret = (ret < 0 ? -errno : -EIO);
237 goto out;
238 }
239
240 /* create the items for the extent tree */
241 memset(buf->data+sizeof(struct btrfs_header), 0,
242 leafsize-sizeof(struct btrfs_header));
243 nritems = 0;
244 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize);
245 for (i = 1; i < 7; i++) {
246 item_size = sizeof(struct btrfs_extent_item);
247 if (!skinny_metadata)
248 item_size += sizeof(struct btrfs_tree_block_info);
249
250 BUG_ON(blocks[i] < first_free);
251 BUG_ON(blocks[i] < blocks[i - 1]);
252
253 /* create extent item */
254 itemoff -= item_size;
255 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
256 if (skinny_metadata) {
257 btrfs_set_disk_key_type(&disk_key,
258 BTRFS_METADATA_ITEM_KEY);
259 btrfs_set_disk_key_offset(&disk_key, 0);
260 } else {
261 btrfs_set_disk_key_type(&disk_key,
262 BTRFS_EXTENT_ITEM_KEY);
263 btrfs_set_disk_key_offset(&disk_key, leafsize);
264 }
265 btrfs_set_item_key(buf, &disk_key, nritems);
266 btrfs_set_item_offset(buf, btrfs_item_nr(nritems),
267 itemoff);
268 btrfs_set_item_size(buf, btrfs_item_nr(nritems),
269 item_size);
270 extent_item = btrfs_item_ptr(buf, nritems,
271 struct btrfs_extent_item);
272 btrfs_set_extent_refs(buf, extent_item, 1);
273 btrfs_set_extent_generation(buf, extent_item, 1);
274 btrfs_set_extent_flags(buf, extent_item,
275 BTRFS_EXTENT_FLAG_TREE_BLOCK);
276 nritems++;
277
278 /* create extent ref */
279 ref_root = reference_root_table[i];
280 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
281 btrfs_set_disk_key_offset(&disk_key, ref_root);
282 btrfs_set_disk_key_type(&disk_key, BTRFS_TREE_BLOCK_REF_KEY);
283 btrfs_set_item_key(buf, &disk_key, nritems);
284 btrfs_set_item_offset(buf, btrfs_item_nr(nritems),
285 itemoff);
286 btrfs_set_item_size(buf, btrfs_item_nr(nritems), 0);
287 nritems++;
288 }
289 btrfs_set_header_bytenr(buf, blocks[2]);
290 btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
291 btrfs_set_header_nritems(buf, nritems);
292 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
293 ret = pwrite(fd, buf->data, leafsize, blocks[2]);
294 if (ret != leafsize) {
295 ret = (ret < 0 ? -errno : -EIO);
296 goto out;
297 }
298
299 /* create the chunk tree */
300 memset(buf->data+sizeof(struct btrfs_header), 0,
301 leafsize-sizeof(struct btrfs_header));
302 nritems = 0;
303 item_size = sizeof(*dev_item);
304 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - item_size;
305
306 /* first device 1 (there is no device 0) */
307 btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
308 btrfs_set_disk_key_offset(&disk_key, 1);
309 btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
310 btrfs_set_item_key(buf, &disk_key, nritems);
311 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
312 btrfs_set_item_size(buf, btrfs_item_nr(nritems), item_size);
313
314 dev_item = btrfs_item_ptr(buf, nritems, struct btrfs_dev_item);
315 btrfs_set_device_id(buf, dev_item, 1);
316 btrfs_set_device_generation(buf, dev_item, 0);
317 btrfs_set_device_total_bytes(buf, dev_item, num_bytes);
318 btrfs_set_device_bytes_used(buf, dev_item,
319 BTRFS_MKFS_SYSTEM_GROUP_SIZE);
320 btrfs_set_device_io_align(buf, dev_item, sectorsize);
321 btrfs_set_device_io_width(buf, dev_item, sectorsize);
322 btrfs_set_device_sector_size(buf, dev_item, sectorsize);
323 btrfs_set_device_type(buf, dev_item, 0);
324
325 write_extent_buffer(buf, super.dev_item.uuid,
326 (unsigned long)btrfs_device_uuid(dev_item),
327 BTRFS_UUID_SIZE);
328 write_extent_buffer(buf, super.fsid,
329 (unsigned long)btrfs_device_fsid(dev_item),
330 BTRFS_UUID_SIZE);
331 read_extent_buffer(buf, &super.dev_item, (unsigned long)dev_item,
332 sizeof(*dev_item));
333
334 nritems++;
335 item_size = btrfs_chunk_item_size(1);
336 itemoff = itemoff - item_size;
337
338 /* then we have chunk 0 */
339 btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
340 btrfs_set_disk_key_offset(&disk_key, 0);
341 btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
342 btrfs_set_item_key(buf, &disk_key, nritems);
343 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
344 btrfs_set_item_size(buf, btrfs_item_nr(nritems), item_size);
345
346 chunk = btrfs_item_ptr(buf, nritems, struct btrfs_chunk);
347 btrfs_set_chunk_length(buf, chunk, BTRFS_MKFS_SYSTEM_GROUP_SIZE);
348 btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
349 btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);
350 btrfs_set_chunk_type(buf, chunk, BTRFS_BLOCK_GROUP_SYSTEM);
351 btrfs_set_chunk_io_align(buf, chunk, sectorsize);
352 btrfs_set_chunk_io_width(buf, chunk, sectorsize);
353 btrfs_set_chunk_sector_size(buf, chunk, sectorsize);
354 btrfs_set_chunk_num_stripes(buf, chunk, 1);
355 btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
356 btrfs_set_stripe_offset_nr(buf, chunk, 0, 0);
357 nritems++;
358
359 write_extent_buffer(buf, super.dev_item.uuid,
360 (unsigned long)btrfs_stripe_dev_uuid(&chunk->stripe),
361 BTRFS_UUID_SIZE);
362
363 /* copy the key for the chunk to the system array */
364 ptr = super.sys_chunk_array;
365 array_size = sizeof(disk_key);
366
367 memcpy(ptr, &disk_key, sizeof(disk_key));
368 ptr += sizeof(disk_key);
369
370 /* copy the chunk to the system array */
371 read_extent_buffer(buf, ptr, (unsigned long)chunk, item_size);
372 array_size += item_size;
373 ptr += item_size;
374 btrfs_set_super_sys_array_size(&super, array_size);
375
376 btrfs_set_header_bytenr(buf, blocks[3]);
377 btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);
378 btrfs_set_header_nritems(buf, nritems);
379 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
380 ret = pwrite(fd, buf->data, leafsize, blocks[3]);
381 if (ret != leafsize) {
382 ret = (ret < 0 ? -errno : -EIO);
383 goto out;
384 }
385
386 /* create the device tree */
387 memset(buf->data+sizeof(struct btrfs_header), 0,
388 leafsize-sizeof(struct btrfs_header));
389 nritems = 0;
390 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
391 sizeof(struct btrfs_dev_extent);
392
393 btrfs_set_disk_key_objectid(&disk_key, 1);
394 btrfs_set_disk_key_offset(&disk_key, 0);
395 btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
396 btrfs_set_item_key(buf, &disk_key, nritems);
397 btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
398 btrfs_set_item_size(buf, btrfs_item_nr(nritems),
399 sizeof(struct btrfs_dev_extent));
400 dev_extent = btrfs_item_ptr(buf, nritems, struct btrfs_dev_extent);
401 btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
402 BTRFS_CHUNK_TREE_OBJECTID);
403 btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
404 BTRFS_FIRST_CHUNK_TREE_OBJECTID);
405 btrfs_set_dev_extent_chunk_offset(buf, dev_extent, 0);
406
407 write_extent_buffer(buf, chunk_tree_uuid,
408 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(dev_extent),
409 BTRFS_UUID_SIZE);
410
411 btrfs_set_dev_extent_length(buf, dev_extent,
412 BTRFS_MKFS_SYSTEM_GROUP_SIZE);
413 nritems++;
414
415 btrfs_set_header_bytenr(buf, blocks[4]);
416 btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);
417 btrfs_set_header_nritems(buf, nritems);
418 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
419 ret = pwrite(fd, buf->data, leafsize, blocks[4]);
420 if (ret != leafsize) {
421 ret = (ret < 0 ? -errno : -EIO);
422 goto out;
423 }
424
425 /* create the FS root */
426 memset(buf->data+sizeof(struct btrfs_header), 0,
427 leafsize-sizeof(struct btrfs_header));
428 btrfs_set_header_bytenr(buf, blocks[5]);
429 btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
430 btrfs_set_header_nritems(buf, 0);
431 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
432 ret = pwrite(fd, buf->data, leafsize, blocks[5]);
433 if (ret != leafsize) {
434 ret = (ret < 0 ? -errno : -EIO);
435 goto out;
436 }
437 /* finally create the csum root */
438 memset(buf->data+sizeof(struct btrfs_header), 0,
439 leafsize-sizeof(struct btrfs_header));
440 btrfs_set_header_bytenr(buf, blocks[6]);
441 btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);
442 btrfs_set_header_nritems(buf, 0);
443 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
444 ret = pwrite(fd, buf->data, leafsize, blocks[6]);
445 if (ret != leafsize) {
446 ret = (ret < 0 ? -errno : -EIO);
447 goto out;
448 }
449
450 /* and write out the super block */
451 BUG_ON(sizeof(super) > sectorsize);
452 memset(buf->data, 0, sectorsize);
453 memcpy(buf->data, &super, sizeof(super));
454 buf->len = sectorsize;
455 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
456 ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
457 if (ret != sectorsize) {
458 ret = (ret < 0 ? -errno : -EIO);
459 goto out;
460 }
461
462 ret = 0;
463
464 out:
465 free(buf);
466 return ret;
467 }
468
469 u64 btrfs_device_size(int fd, struct stat *st)
470 {
471 u64 size;
472 if (S_ISREG(st->st_mode)) {
473 return st->st_size;
474 }
475 if (!S_ISBLK(st->st_mode)) {
476 return 0;
477 }
478 if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
479 return size;
480 }
481 return 0;
482 }
483
484 static int zero_blocks(int fd, off_t start, size_t len)
485 {
486 char *buf = malloc(len);
487 int ret = 0;
488 ssize_t written;
489
490 if (!buf)
491 return -ENOMEM;
492 memset(buf, 0, len);
493 written = pwrite(fd, buf, len, start);
494 if (written != len)
495 ret = -EIO;
496 free(buf);
497 return ret;
498 }
499
500 static int zero_dev_start(int fd)
501 {
502 off_t start = 0;
503 size_t len = 2 * 1024 * 1024;
504
505 #ifdef __sparc__
506 /* don't overwrite the disk labels on sparc */
507 start = 1024;
508 len -= 1024;
509 #endif
510 return zero_blocks(fd, start, len);
511 }
512
513 static int zero_dev_end(int fd, u64 dev_size)
514 {
515 size_t len = 2 * 1024 * 1024;
516 off_t start = dev_size - len;
517
518 return zero_blocks(fd, start, len);
519 }
520
521 int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
522 struct btrfs_root *root, int fd, char *path,
523 u64 block_count, u32 io_width, u32 io_align,
524 u32 sectorsize)
525 {
526 struct btrfs_super_block *disk_super;
527 struct btrfs_super_block *super = root->fs_info->super_copy;
528 struct btrfs_device *device;
529 struct btrfs_dev_item *dev_item;
530 char *buf;
531 u64 total_bytes;
532 u64 num_devs;
533 int ret;
534
535 device = kzalloc(sizeof(*device), GFP_NOFS);
536 if (!device)
537 return -ENOMEM;
538 buf = kmalloc(sectorsize, GFP_NOFS);
539 if (!buf) {
540 kfree(device);
541 return -ENOMEM;
542 }
543 BUG_ON(sizeof(*disk_super) > sectorsize);
544 memset(buf, 0, sectorsize);
545
546 disk_super = (struct btrfs_super_block *)buf;
547 dev_item = &disk_super->dev_item;
548
549 uuid_generate(device->uuid);
550 device->devid = 0;
551 device->type = 0;
552 device->io_width = io_width;
553 device->io_align = io_align;
554 device->sector_size = sectorsize;
555 device->fd = fd;
556 device->writeable = 1;
557 device->total_bytes = block_count;
558 device->bytes_used = 0;
559 device->total_ios = 0;
560 device->dev_root = root->fs_info->dev_root;
561
562 ret = btrfs_add_device(trans, root, device);
563 BUG_ON(ret);
564
565 total_bytes = btrfs_super_total_bytes(super) + block_count;
566 btrfs_set_super_total_bytes(super, total_bytes);
567
568 num_devs = btrfs_super_num_devices(super) + 1;
569 btrfs_set_super_num_devices(super, num_devs);
570
571 memcpy(disk_super, super, sizeof(*disk_super));
572
573 printf("adding device %s id %llu\n", path,
574 (unsigned long long)device->devid);
575
576 btrfs_set_super_bytenr(disk_super, BTRFS_SUPER_INFO_OFFSET);
577 btrfs_set_stack_device_id(dev_item, device->devid);
578 btrfs_set_stack_device_type(dev_item, device->type);
579 btrfs_set_stack_device_io_align(dev_item, device->io_align);
580 btrfs_set_stack_device_io_width(dev_item, device->io_width);
581 btrfs_set_stack_device_sector_size(dev_item, device->sector_size);
582 btrfs_set_stack_device_total_bytes(dev_item, device->total_bytes);
583 btrfs_set_stack_device_bytes_used(dev_item, device->bytes_used);
584 memcpy(&dev_item->uuid, device->uuid, BTRFS_UUID_SIZE);
585
586 ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
587 BUG_ON(ret != sectorsize);
588
589 kfree(buf);
590 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
591 device->fs_devices = root->fs_info->fs_devices;
592 return 0;
593 }
594
595 int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret,
596 u64 max_block_count, int *mixed, int discard)
597 {
598 u64 block_count;
599 u64 bytenr;
600 struct stat st;
601 int i, ret;
602
603 ret = fstat(fd, &st);
604 if (ret < 0) {
605 fprintf(stderr, "unable to stat %s\n", file);
606 return 1;
607 }
608
609 block_count = btrfs_device_size(fd, &st);
610 if (block_count == 0) {
611 fprintf(stderr, "unable to find %s size\n", file);
612 return 1;
613 }
614 if (max_block_count)
615 block_count = min(block_count, max_block_count);
616
617 if (block_count < 1024 * 1024 * 1024 && !(*mixed)) {
618 printf("SMALL VOLUME: forcing mixed metadata/data groups\n");
619 *mixed = 1;
620 }
621
622 if (discard) {
623 /*
624 * We intentionally ignore errors from the discard ioctl. It
625 * is not necessary for the mkfs functionality but just an
626 * optimization.
627 */
628 if (discard_range(fd, 0, 0) == 0) {
629 fprintf(stderr, "Performing full device TRIM (%s) ...\n",
630 pretty_size(block_count));
631 discard_blocks(fd, 0, block_count);
632 }
633 }
634
635 ret = zero_dev_start(fd);
636 if (ret)
637 goto zero_dev_error;
638
639 for (i = 0 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {
640 bytenr = btrfs_sb_offset(i);
641 if (bytenr >= block_count)
642 break;
643 ret = zero_blocks(fd, bytenr, BTRFS_SUPER_INFO_SIZE);
644 if (ret)
645 goto zero_dev_error;
646 }
647
648 if (zero_end) {
649 ret = zero_dev_end(fd, block_count);
650 if (ret)
651 goto zero_dev_error;
652 }
653 *block_count_ret = block_count;
654
655 zero_dev_error:
656 if (ret < 0) {
657 fprintf(stderr, "ERROR: failed to zero device '%s' - %s\n",
658 file, strerror(-ret));
659 return 1;
660 } else if (ret > 0) {
661 fprintf(stderr, "ERROR: failed to zero device '%s' - %d\n",
662 file, ret);
663 return 1;
664 }
665 return 0;
666 }
667
668 int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
669 struct btrfs_root *root, u64 objectid)
670 {
671 int ret;
672 struct btrfs_inode_item inode_item;
673 time_t now = time(NULL);
674
675 memset(&inode_item, 0, sizeof(inode_item));
676 btrfs_set_stack_inode_generation(&inode_item, trans->transid);
677 btrfs_set_stack_inode_size(&inode_item, 0);
678 btrfs_set_stack_inode_nlink(&inode_item, 1);
679 btrfs_set_stack_inode_nbytes(&inode_item, root->leafsize);
680 btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);
681 btrfs_set_stack_timespec_sec(&inode_item.atime, now);
682 btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);
683 btrfs_set_stack_timespec_sec(&inode_item.ctime, now);
684 btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);
685 btrfs_set_stack_timespec_sec(&inode_item.mtime, now);
686 btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);
687 btrfs_set_stack_timespec_sec(&inode_item.otime, 0);
688 btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);
689
690 if (root->fs_info->tree_root == root)
691 btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);
692
693 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
694 if (ret)
695 goto error;
696
697 ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);
698 if (ret)
699 goto error;
700
701 btrfs_set_root_dirid(&root->root_item, objectid);
702 ret = 0;
703 error:
704 return ret;
705 }
706
707 /*
708 * checks if a path is a block device node
709 * Returns negative errno on failure, otherwise
710 * returns 1 for blockdev, 0 for not-blockdev
711 */
712 int is_block_device(const char *path)
713 {
714 struct stat statbuf;
715
716 if (stat(path, &statbuf) < 0)
717 return -errno;
718
719 return S_ISBLK(statbuf.st_mode);
720 }
721
722 /*
723 * check if given path is a mount point
724 * return 1 if yes. 0 if no. -1 for error
725 */
726 int is_mount_point(const char *path)
727 {
728 FILE *f;
729 struct mntent *mnt;
730 int ret = 0;
731
732 f = setmntent("/proc/self/mounts", "r");
733 if (f == NULL)
734 return -1;
735
736 while ((mnt = getmntent(f)) != NULL) {
737 if (strcmp(mnt->mnt_dir, path))
738 continue;
739 ret = 1;
740 break;
741 }
742 endmntent(f);
743 return ret;
744 }
745
746 /*
747 * Find the mount point for a mounted device.
748 * On success, returns 0 with mountpoint in *mp.
749 * On failure, returns -errno (not mounted yields -EINVAL)
750 * Is noisy on failures, expects to be given a mounted device.
751 */
752 int get_btrfs_mount(const char *dev, char *mp, size_t mp_size)
753 {
754 int ret;
755 int fd = -1;
756
757 ret = is_block_device(dev);
758 if (ret <= 0) {
759 if (!ret) {
760 fprintf(stderr, "%s is not a block device\n", dev);
761 ret = -EINVAL;
762 } else {
763 fprintf(stderr, "Could not check %s: %s\n",
764 dev, strerror(-ret));
765 }
766 goto out;
767 }
768
769 fd = open(dev, O_RDONLY);
770 if (fd < 0) {
771 ret = -errno;
772 fprintf(stderr, "Could not open %s: %s\n", dev, strerror(errno));
773 goto out;
774 }
775
776 ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
777 if (!ret) {
778 ret = -EINVAL;
779 } else { /* mounted, all good */
780 ret = 0;
781 }
782 out:
783 if (fd != -1)
784 close(fd);
785 return ret;
786 }
787
788 /*
789 * Given a pathname, return a filehandle to:
790 * the original pathname or,
791 * if the pathname is a mounted btrfs device, to its mountpoint.
792 *
793 * On error, return -1, errno should be set.
794 */
795 int open_path_or_dev_mnt(const char *path, DIR **dirstream)
796 {
797 char mp[BTRFS_PATH_NAME_MAX + 1];
798 int fdmnt;
799
800 if (is_block_device(path)) {
801 int ret;
802
803 ret = get_btrfs_mount(path, mp, sizeof(mp));
804 if (ret < 0) {
805 /* not a mounted btrfs dev */
806 errno = EINVAL;
807 return -1;
808 }
809 fdmnt = open_file_or_dir(mp, dirstream);
810 } else {
811 fdmnt = open_file_or_dir(path, dirstream);
812 }
813
814 return fdmnt;
815 }
816
817 /* checks if a device is a loop device */
818 static int is_loop_device (const char* device) {
819 struct stat statbuf;
820
821 if(stat(device, &statbuf) < 0)
822 return -errno;
823
824 return (S_ISBLK(statbuf.st_mode) &&
825 MAJOR(statbuf.st_rdev) == LOOP_MAJOR);
826 }
827
828
829 /* Takes a loop device path (e.g. /dev/loop0) and returns
830 * the associated file (e.g. /images/my_btrfs.img) */
831 static int resolve_loop_device(const char* loop_dev, char* loop_file,
832 int max_len)
833 {
834 int ret;
835 FILE *f;
836 char fmt[20];
837 char p[PATH_MAX];
838 char real_loop_dev[PATH_MAX];
839
840 if (!realpath(loop_dev, real_loop_dev))
841 return -errno;
842 snprintf(p, PATH_MAX, "/sys/block/%s/loop/backing_file", strrchr(real_loop_dev, '/'));
843 if (!(f = fopen(p, "r")))
844 return -errno;
845
846 snprintf(fmt, 20, "%%%i[^\n]", max_len-1);
847 ret = fscanf(f, fmt, loop_file);
848 fclose(f);
849 if (ret == EOF)
850 return -errno;
851
852 return 0;
853 }
854
855 /* Checks whether a and b are identical or device
856 * files associated with the same block device
857 */
858 static int is_same_blk_file(const char* a, const char* b)
859 {
860 struct stat st_buf_a, st_buf_b;
861 char real_a[PATH_MAX];
862 char real_b[PATH_MAX];
863
864 if(!realpath(a, real_a))
865 strcpy(real_a, a);
866
867 if (!realpath(b, real_b))
868 strcpy(real_b, b);
869
870 /* Identical path? */
871 if(strcmp(real_a, real_b) == 0)
872 return 1;
873
874 if(stat(a, &st_buf_a) < 0 ||
875 stat(b, &st_buf_b) < 0)
876 {
877 if (errno == ENOENT)
878 return 0;
879 return -errno;
880 }
881
882 /* Same blockdevice? */
883 if(S_ISBLK(st_buf_a.st_mode) &&
884 S_ISBLK(st_buf_b.st_mode) &&
885 st_buf_a.st_rdev == st_buf_b.st_rdev)
886 {
887 return 1;
888 }
889
890 /* Hardlink? */
891 if (st_buf_a.st_dev == st_buf_b.st_dev &&
892 st_buf_a.st_ino == st_buf_b.st_ino)
893 {
894 return 1;
895 }
896
897 return 0;
898 }
899
900 /* checks if a and b are identical or device
901 * files associated with the same block device or
902 * if one file is a loop device that uses the other
903 * file.
904 */
905 static int is_same_loop_file(const char* a, const char* b)
906 {
907 char res_a[PATH_MAX];
908 char res_b[PATH_MAX];
909 const char* final_a = NULL;
910 const char* final_b = NULL;
911 int ret;
912
913 /* Resolve a if it is a loop device */
914 if((ret = is_loop_device(a)) < 0) {
915 if (ret == -ENOENT)
916 return 0;
917 return ret;
918 } else if (ret) {
919 ret = resolve_loop_device(a, res_a, sizeof(res_a));
920 if (ret < 0) {
921 if (errno != EPERM)
922 return ret;
923 } else {
924 final_a = res_a;
925 }
926 } else {
927 final_a = a;
928 }
929
930 /* Resolve b if it is a loop device */
931 if ((ret = is_loop_device(b)) < 0) {
932 if (ret == -ENOENT)
933 return 0;
934 return ret;
935 } else if (ret) {
936 ret = resolve_loop_device(b, res_b, sizeof(res_b));
937 if (ret < 0) {
938 if (errno != EPERM)
939 return ret;
940 } else {
941 final_b = res_b;
942 }
943 } else {
944 final_b = b;
945 }
946
947 return is_same_blk_file(final_a, final_b);
948 }
949
950 /* Checks if a file exists and is a block or regular file*/
951 static int is_existing_blk_or_reg_file(const char* filename)
952 {
953 struct stat st_buf;
954
955 if(stat(filename, &st_buf) < 0) {
956 if(errno == ENOENT)
957 return 0;
958 else
959 return -errno;
960 }
961
962 return (S_ISBLK(st_buf.st_mode) || S_ISREG(st_buf.st_mode));
963 }
964
965 /* Checks if a file is used (directly or indirectly via a loop device)
966 * by a device in fs_devices
967 */
968 static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices,
969 const char* file)
970 {
971 int ret;
972 struct list_head *head;
973 struct list_head *cur;
974 struct btrfs_device *device;
975
976 head = &fs_devices->devices;
977 list_for_each(cur, head) {
978 device = list_entry(cur, struct btrfs_device, dev_list);
979
980 if((ret = is_same_loop_file(device->name, file)))
981 return ret;
982 }
983
984 return 0;
985 }
986
987 /*
988 * returns 1 if the device was mounted, < 0 on error or 0 if everything
989 * is safe to continue.
990 */
991 int check_mounted(const char* file)
992 {
993 int fd;
994 int ret;
995
996 fd = open(file, O_RDONLY);
997 if (fd < 0) {
998 fprintf (stderr, "check_mounted(): Could not open %s\n", file);
999 return -errno;
1000 }
1001
1002 ret = check_mounted_where(fd, file, NULL, 0, NULL);
1003 close(fd);
1004
1005 return ret;
1006 }
1007
1008 int check_mounted_where(int fd, const char *file, char *where, int size,
1009 struct btrfs_fs_devices **fs_dev_ret)
1010 {
1011 int ret;
1012 u64 total_devs = 1;
1013 int is_btrfs;
1014 struct btrfs_fs_devices *fs_devices_mnt = NULL;
1015 FILE *f;
1016 struct mntent *mnt;
1017
1018 /* scan the initial device */
1019 ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
1020 &total_devs, BTRFS_SUPER_INFO_OFFSET);
1021 is_btrfs = (ret >= 0);
1022
1023 /* scan other devices */
1024 if (is_btrfs && total_devs > 1) {
1025 if ((ret = btrfs_scan_for_fsid(!BTRFS_UPDATE_KERNEL)))
1026 return ret;
1027 }
1028
1029 /* iterate over the list of currently mountes filesystems */
1030 if ((f = setmntent ("/proc/self/mounts", "r")) == NULL)
1031 return -errno;
1032
1033 while ((mnt = getmntent (f)) != NULL) {
1034 if(is_btrfs) {
1035 if(strcmp(mnt->mnt_type, "btrfs") != 0)
1036 continue;
1037
1038 ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname);
1039 } else {
1040 /* ignore entries in the mount table that are not
1041 associated with a file*/
1042 if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0)
1043 goto out_mntloop_err;
1044 else if(!ret)
1045 continue;
1046
1047 ret = is_same_loop_file(file, mnt->mnt_fsname);
1048 }
1049
1050 if(ret < 0)
1051 goto out_mntloop_err;
1052 else if(ret)
1053 break;
1054 }
1055
1056 /* Did we find an entry in mnt table? */
1057 if (mnt && size && where) {
1058 strncpy(where, mnt->mnt_dir, size);
1059 where[size-1] = 0;
1060 }
1061 if (fs_dev_ret)
1062 *fs_dev_ret = fs_devices_mnt;
1063
1064 ret = (mnt != NULL);
1065
1066 out_mntloop_err:
1067 endmntent (f);
1068
1069 return ret;
1070 }
1071
1072 struct pending_dir {
1073 struct list_head list;
1074 char name[PATH_MAX];
1075 };
1076
1077 void btrfs_register_one_device(char *fname)
1078 {
1079 struct btrfs_ioctl_vol_args args;
1080 int fd;
1081 int ret;
1082 int e;
1083
1084 fd = open("/dev/btrfs-control", O_RDONLY);
1085 if (fd < 0) {
1086 fprintf(stderr, "failed to open /dev/btrfs-control "
1087 "skipping device registration: %s\n",
1088 strerror(errno));
1089 return;
1090 }
1091 strncpy(args.name, fname, BTRFS_PATH_NAME_MAX);
1092 args.name[BTRFS_PATH_NAME_MAX-1] = 0;
1093 ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
1094 e = errno;
1095 if(ret<0){
1096 fprintf(stderr, "ERROR: device scan failed '%s' - %s\n",
1097 fname, strerror(e));
1098 }
1099 close(fd);
1100 }
1101
1102 int btrfs_scan_one_dir(char *dirname, int run_ioctl)
1103 {
1104 DIR *dirp = NULL;
1105 struct dirent *dirent;
1106 struct pending_dir *pending;
1107 struct stat st;
1108 int ret;
1109 int fd;
1110 int dirname_len;
1111 char *fullpath;
1112 struct list_head pending_list;
1113 struct btrfs_fs_devices *tmp_devices;
1114 u64 num_devices;
1115
1116 INIT_LIST_HEAD(&pending_list);
1117
1118 pending = malloc(sizeof(*pending));
1119 if (!pending)
1120 return -ENOMEM;
1121 strcpy(pending->name, dirname);
1122
1123 again:
1124 dirname_len = strlen(pending->name);
1125 fullpath = malloc(PATH_MAX);
1126 dirname = pending->name;
1127
1128 if (!fullpath) {
1129 ret = -ENOMEM;
1130 goto fail;
1131 }
1132 dirp = opendir(dirname);
1133 if (!dirp) {
1134 fprintf(stderr, "Unable to open %s for scanning\n", dirname);
1135 ret = -errno;
1136 goto fail;
1137 }
1138 while(1) {
1139 dirent = readdir(dirp);
1140 if (!dirent)
1141 break;
1142 if (dirent->d_name[0] == '.')
1143 continue;
1144 if (dirname_len + strlen(dirent->d_name) + 2 > PATH_MAX) {
1145 ret = -EFAULT;
1146 goto fail;
1147 }
1148 snprintf(fullpath, PATH_MAX, "%s/%s", dirname, dirent->d_name);
1149 ret = lstat(fullpath, &st);
1150 if (ret < 0) {
1151 fprintf(stderr, "failed to stat %s\n", fullpath);
1152 continue;
1153 }
1154 if (S_ISLNK(st.st_mode))
1155 continue;
1156 if (S_ISDIR(st.st_mode)) {
1157 struct pending_dir *next = malloc(sizeof(*next));
1158 if (!next) {
1159 ret = -ENOMEM;
1160 goto fail;
1161 }
1162 strcpy(next->name, fullpath);
1163 list_add_tail(&next->list, &pending_list);
1164 }
1165 if (!S_ISBLK(st.st_mode)) {
1166 continue;
1167 }
1168 fd = open(fullpath, O_RDONLY);
1169 if (fd < 0) {
1170 /* ignore the following errors:
1171 ENXIO (device don't exists)
1172 ENOMEDIUM (No medium found ->
1173 like a cd tray empty)
1174 */
1175 if(errno != ENXIO && errno != ENOMEDIUM)
1176 fprintf(stderr, "failed to read %s: %s\n",
1177 fullpath, strerror(errno));
1178 continue;
1179 }
1180 ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
1181 &num_devices,
1182 BTRFS_SUPER_INFO_OFFSET);
1183 if (ret == 0 && run_ioctl > 0) {
1184 btrfs_register_one_device(fullpath);
1185 }
1186 close(fd);
1187 }
1188 if (!list_empty(&pending_list)) {
1189 free(pending);
1190 pending = list_entry(pending_list.next, struct pending_dir,
1191 list);
1192 free(fullpath);
1193 list_del(&pending->list);
1194 closedir(dirp);
1195 dirp = NULL;
1196 goto again;
1197 }
1198 ret = 0;
1199 fail:
1200 free(pending);
1201 free(fullpath);
1202 while (!list_empty(&pending_list)) {
1203 pending = list_entry(pending_list.next, struct pending_dir,
1204 list);
1205 list_del(&pending->list);
1206 free(pending);
1207 }
1208 if (dirp)
1209 closedir(dirp);
1210 return ret;
1211 }
1212
1213 int btrfs_scan_for_fsid(int run_ioctls)
1214 {
1215 int ret;
1216
1217 ret = scan_for_btrfs(BTRFS_SCAN_PROC, run_ioctls);
1218 if (ret)
1219 ret = scan_for_btrfs(BTRFS_SCAN_DEV, run_ioctls);
1220 return ret;
1221 }
1222
1223 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
1224 int super_offset)
1225 {
1226 struct btrfs_super_block *disk_super;
1227 char *buf;
1228 int ret = 0;
1229
1230 buf = malloc(BTRFS_SUPER_INFO_SIZE);
1231 if (!buf) {
1232 ret = -ENOMEM;
1233 goto out;
1234 }
1235 ret = pread(fd, buf, BTRFS_SUPER_INFO_SIZE, super_offset);
1236 if (ret != BTRFS_SUPER_INFO_SIZE)
1237 goto brelse;
1238
1239 ret = 0;
1240 disk_super = (struct btrfs_super_block *)buf;
1241 if (btrfs_super_magic(disk_super) != BTRFS_MAGIC)
1242 goto brelse;
1243
1244 if (!memcmp(disk_super->fsid, root->fs_info->super_copy->fsid,
1245 BTRFS_FSID_SIZE))
1246 ret = 1;
1247 brelse:
1248 free(buf);
1249 out:
1250 return ret;
1251 }
1252
1253 static char *size_strs[] = { "", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"};
1254 int pretty_size_snprintf(u64 size, char *str, size_t str_bytes)
1255 {
1256 int num_divs = 0;
1257 float fraction;
1258
1259 if (str_bytes == 0)
1260 return 0;
1261
1262 if( size < 1024 ){
1263 fraction = size;
1264 num_divs = 0;
1265 } else {
1266 u64 last_size = size;
1267 num_divs = 0;
1268 while(size >= 1024){
1269 last_size = size;
1270 size /= 1024;
1271 num_divs ++;
1272 }
1273
1274 if (num_divs >= ARRAY_SIZE(size_strs)) {
1275 str[0] = '\0';
1276 return -1;
1277 }
1278 fraction = (float)last_size / 1024;
1279 }
1280 return snprintf(str, str_bytes, "%.2f%s", fraction,
1281 size_strs[num_divs]);
1282 }
1283
1284 /*
1285 * __strncpy__null - strncpy with null termination
1286 * @dest: the target array
1287 * @src: the source string
1288 * @n: maximum bytes to copy (size of *dest)
1289 *
1290 * Like strncpy, but ensures destination is null-terminated.
1291 *
1292 * Copies the string pointed to by src, including the terminating null
1293 * byte ('\0'), to the buffer pointed to by dest, up to a maximum
1294 * of n bytes. Then ensure that dest is null-terminated.
1295 */
1296 char *__strncpy__null(char *dest, const char *src, size_t n)
1297 {
1298 strncpy(dest, src, n);
1299 if (n > 0)
1300 dest[n - 1] = '\0';
1301 return dest;
1302 }
1303
1304 /*
1305 * Checks to make sure that the label matches our requirements.
1306 * Returns:
1307 0 if everything is safe and usable
1308 -1 if the label is too long
1309 */
1310 static int check_label(const char *input)
1311 {
1312 int len = strlen(input);
1313
1314 if (len > BTRFS_LABEL_SIZE - 1) {
1315 fprintf(stderr, "ERROR: Label %s is too long (max %d)\n",
1316 input, BTRFS_LABEL_SIZE - 1);
1317 return -1;
1318 }
1319
1320 return 0;
1321 }
1322
1323 static int set_label_unmounted(const char *dev, const char *label)
1324 {
1325 struct btrfs_trans_handle *trans;
1326 struct btrfs_root *root;
1327 int ret;
1328
1329 ret = check_mounted(dev);
1330 if (ret < 0) {
1331 fprintf(stderr, "FATAL: error checking %s mount status\n", dev);
1332 return -1;
1333 }
1334 if (ret > 0) {
1335 fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n",
1336 dev);
1337 return -1;
1338 }
1339
1340 /* Open the super_block at the default location
1341 * and as read-write.
1342 */
1343 root = open_ctree(dev, 0, OPEN_CTREE_WRITES);
1344 if (!root) /* errors are printed by open_ctree() */
1345 return -1;
1346
1347 trans = btrfs_start_transaction(root, 1);
1348 snprintf(root->fs_info->super_copy->label, BTRFS_LABEL_SIZE, "%s",
1349 label);
1350 btrfs_commit_transaction(trans, root);
1351
1352 /* Now we close it since we are done. */
1353 close_ctree(root);
1354 return 0;
1355 }
1356
1357 static int set_label_mounted(const char *mount_path, const char *label)
1358 {
1359 int fd;
1360
1361 fd = open(mount_path, O_RDONLY | O_NOATIME);
1362 if (fd < 0) {
1363 fprintf(stderr, "ERROR: unable to access '%s'\n", mount_path);
1364 return -1;
1365 }
1366
1367 if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) {
1368 fprintf(stderr, "ERROR: unable to set label %s\n",
1369 strerror(errno));
1370 close(fd);
1371 return -1;
1372 }
1373
1374 close(fd);
1375 return 0;
1376 }
1377
1378 static int get_label_unmounted(const char *dev, char *label)
1379 {
1380 struct btrfs_root *root;
1381 int ret;
1382
1383 ret = check_mounted(dev);
1384 if (ret < 0) {
1385 fprintf(stderr, "FATAL: error checking %s mount status\n", dev);
1386 return -1;
1387 }
1388 if (ret > 0) {
1389 fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n",
1390 dev);
1391 return -1;
1392 }
1393
1394 /* Open the super_block at the default location
1395 * and as read-only.
1396 */
1397 root = open_ctree(dev, 0, 0);
1398 if(!root)
1399 return -1;
1400
1401 memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
1402
1403 /* Now we close it since we are done. */
1404 close_ctree(root);
1405 return 0;
1406 }
1407
1408 /*
1409 * If a partition is mounted, try to get the filesystem label via its
1410 * mounted path rather than device. Return the corresponding error
1411 * the user specified the device path.
1412 */
1413 int get_label_mounted(const char *mount_path, char *labelp)
1414 {
1415 char label[BTRFS_LABEL_SIZE];
1416 int fd;
1417
1418 fd = open(mount_path, O_RDONLY | O_NOATIME);
1419 if (fd < 0) {
1420 fprintf(stderr, "ERROR: unable to access '%s'\n", mount_path);
1421 return -1;
1422 }
1423
1424 memset(label, '\0', sizeof(label));
1425 if (ioctl(fd, BTRFS_IOC_GET_FSLABEL, label) < 0) {
1426 fprintf(stderr, "ERROR: unable get label %s\n", strerror(errno));
1427 close(fd);
1428 return -1;
1429 }
1430
1431 strncpy(labelp, label, sizeof(label));
1432 close(fd);
1433 return 0;
1434 }
1435
1436 int get_label(const char *btrfs_dev, char *label)
1437 {
1438 int ret;
1439
1440 if (is_existing_blk_or_reg_file(btrfs_dev))
1441 ret = get_label_unmounted(btrfs_dev, label);
1442 else
1443 ret = get_label_mounted(btrfs_dev, label);
1444
1445 return ret;
1446 }
1447
1448 int set_label(const char *btrfs_dev, const char *label)
1449 {
1450 if (check_label(label))
1451 return -1;
1452
1453 return is_existing_blk_or_reg_file(btrfs_dev) ?
1454 set_label_unmounted(btrfs_dev, label) :
1455 set_label_mounted(btrfs_dev, label);
1456 }
1457
1458 int btrfs_scan_block_devices(int run_ioctl)
1459 {
1460
1461 struct stat st;
1462 int ret;
1463 int fd;
1464 struct btrfs_fs_devices *tmp_devices;
1465 u64 num_devices;
1466 FILE *proc_partitions;
1467 int i;
1468 char buf[1024];
1469 char fullpath[110];
1470 int scans = 0;
1471 int special;
1472
1473 scan_again:
1474 proc_partitions = fopen("/proc/partitions","r");
1475 if (!proc_partitions) {
1476 fprintf(stderr, "Unable to open '/proc/partitions' for scanning\n");
1477 return -ENOENT;
1478 }
1479 /* skip the header */
1480 for (i = 0; i < 2; i++)
1481 if (!fgets(buf, 1023, proc_partitions)) {
1482 fprintf(stderr,
1483 "Unable to read '/proc/partitions' for scanning\n");
1484 fclose(proc_partitions);
1485 return -ENOENT;
1486 }
1487
1488 strcpy(fullpath,"/dev/");
1489 while(fgets(buf, 1023, proc_partitions)) {
1490 i = sscanf(buf," %*d %*d %*d %99s", fullpath+5);
1491
1492 /*
1493 * multipath and MD devices may register as a btrfs filesystem
1494 * both through the original block device and through
1495 * the special (/dev/mapper or /dev/mdX) entry.
1496 * This scans the special entries last
1497 */
1498 special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0;
1499 if (!special)
1500 special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0;
1501
1502 if (scans == 0 && special)
1503 continue;
1504 if (scans > 0 && !special)
1505 continue;
1506
1507 ret = lstat(fullpath, &st);
1508 if (ret < 0) {
1509 fprintf(stderr, "failed to stat %s\n", fullpath);
1510 continue;
1511 }
1512 if (!S_ISBLK(st.st_mode)) {
1513 continue;
1514 }
1515
1516 fd = open(fullpath, O_RDONLY);
1517 if (fd < 0) {
1518 if (errno != ENOMEDIUM)
1519 fprintf(stderr, "failed to open %s: %s\n",
1520 fullpath, strerror(errno));
1521 continue;
1522 }
1523 ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
1524 &num_devices,
1525 BTRFS_SUPER_INFO_OFFSET);
1526 if (ret == 0 && run_ioctl > 0) {
1527 btrfs_register_one_device(fullpath);
1528 }
1529 close(fd);
1530 }
1531
1532 fclose(proc_partitions);
1533
1534 if (scans == 0) {
1535 scans++;
1536 goto scan_again;
1537 }
1538 return 0;
1539 }
1540
1541 u64 parse_size(char *s)
1542 {
1543 int i;
1544 char c;
1545 u64 mult = 1;
1546
1547 for (i = 0; s && s[i] && isdigit(s[i]); i++) ;
1548 if (!i) {
1549 fprintf(stderr, "ERROR: size value is empty\n");
1550 exit(50);
1551 }
1552
1553 if (s[i]) {
1554 c = tolower(s[i]);
1555 switch (c) {
1556 case 'e':
1557 mult *= 1024;
1558 /* fallthrough */
1559 case 'p':
1560 mult *= 1024;
1561 /* fallthrough */
1562 case 't':
1563 mult *= 1024;
1564 /* fallthrough */
1565 case 'g':
1566 mult *= 1024;
1567 /* fallthrough */
1568 case 'm':
1569 mult *= 1024;
1570 /* fallthrough */
1571 case 'k':
1572 mult *= 1024;
1573 /* fallthrough */
1574 case 'b':
1575 break;
1576 default:
1577 fprintf(stderr, "ERROR: Unknown size descriptor "
1578 "'%c'\n", c);
1579 exit(1);
1580 }
1581 }
1582 if (s[i] && s[i+1]) {
1583 fprintf(stderr, "ERROR: Illegal suffix contains "
1584 "character '%c' in wrong position\n",
1585 s[i+1]);
1586 exit(51);
1587 }
1588 return strtoull(s, NULL, 10) * mult;
1589 }
1590
1591 int open_file_or_dir3(const char *fname, DIR **dirstream, int open_flags)
1592 {
1593 int ret;
1594 struct stat st;
1595 int fd;
1596
1597 ret = stat(fname, &st);
1598 if (ret < 0) {
1599 return -1;
1600 }
1601 if (S_ISDIR(st.st_mode)) {
1602 *dirstream = opendir(fname);
1603 if (!*dirstream)
1604 return -1;
1605 fd = dirfd(*dirstream);
1606 } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
1607 fd = open(fname, open_flags);
1608 } else {
1609 /*
1610 * we set this on purpose, in case the caller output
1611 * strerror(errno) as success
1612 */
1613 errno = EINVAL;
1614 return -1;
1615 }
1616 if (fd < 0) {
1617 fd = -1;
1618 if (*dirstream)
1619 closedir(*dirstream);
1620 }
1621 return fd;
1622 }
1623
1624 int open_file_or_dir(const char *fname, DIR **dirstream)
1625 {
1626 return open_file_or_dir3(fname, dirstream, O_RDWR);
1627 }
1628
1629 void close_file_or_dir(int fd, DIR *dirstream)
1630 {
1631 if (dirstream)
1632 closedir(dirstream);
1633 else if (fd >= 0)
1634 close(fd);
1635 }
1636
1637 int get_device_info(int fd, u64 devid,
1638 struct btrfs_ioctl_dev_info_args *di_args)
1639 {
1640 int ret;
1641
1642 di_args->devid = devid;
1643 memset(&di_args->uuid, '\0', sizeof(di_args->uuid));
1644
1645 ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args);
1646 return ret ? -errno : 0;
1647 }
1648
1649 /*
1650 * For a given path, fill in the ioctl fs_ and info_ args.
1651 * If the path is a btrfs mountpoint, fill info for all devices.
1652 * If the path is a btrfs device, fill in only that device.
1653 *
1654 * The path provided must be either on a mounted btrfs fs,
1655 * or be a mounted btrfs device.
1656 *
1657 * Returns 0 on success, or a negative errno.
1658 */
1659 int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args,
1660 struct btrfs_ioctl_dev_info_args **di_ret)
1661 {
1662 int fd = -1;
1663 int ret = 0;
1664 int ndevs = 0;
1665 int i = 0;
1666 struct btrfs_fs_devices *fs_devices_mnt = NULL;
1667 struct btrfs_ioctl_dev_info_args *di_args;
1668 char mp[BTRFS_PATH_NAME_MAX + 1];
1669 DIR *dirstream = NULL;
1670
1671 memset(fi_args, 0, sizeof(*fi_args));
1672
1673 if (is_block_device(path)) {
1674 struct btrfs_super_block *disk_super;
1675 char buf[BTRFS_SUPER_INFO_SIZE];
1676 u64 devid;
1677
1678 /* Ensure it's mounted, then set path to the mountpoint */
1679 fd = open(path, O_RDONLY);
1680 if (fd < 0) {
1681 ret = -errno;
1682 fprintf(stderr, "Couldn't open %s: %s\n",
1683 path, strerror(errno));
1684 goto out;
1685 }
1686 ret = check_mounted_where(fd, path, mp, sizeof(mp),
1687 &fs_devices_mnt);
1688 if (!ret) {
1689 ret = -EINVAL;
1690 goto out;
1691 }
1692 if (ret < 0)
1693 goto out;
1694 path = mp;
1695 /* Only fill in this one device */
1696 fi_args->num_devices = 1;
1697
1698 disk_super = (struct btrfs_super_block *)buf;
1699 ret = btrfs_read_dev_super(fd, disk_super, BTRFS_SUPER_INFO_OFFSET);
1700 if (ret < 0) {
1701 ret = -EIO;
1702 goto out;
1703 }
1704 devid = btrfs_stack_device_id(&disk_super->dev_item);
1705
1706 fi_args->max_id = devid;
1707 i = devid;
1708
1709 memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE);
1710 close(fd);
1711 }
1712
1713 /* at this point path must not be for a block device */
1714 fd = open_file_or_dir(path, &dirstream);
1715 if (fd < 0) {
1716 ret = -errno;
1717 goto out;
1718 }
1719
1720 /* fill in fi_args if not just a single device */
1721 if (fi_args->num_devices != 1) {
1722 ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
1723 if (ret < 0) {
1724 ret = -errno;
1725 goto out;
1726 }
1727 }
1728
1729 if (!fi_args->num_devices)
1730 goto out;
1731
1732 di_args = *di_ret = malloc(fi_args->num_devices * sizeof(*di_args));
1733 if (!di_args) {
1734 ret = -errno;
1735 goto out;
1736 }
1737
1738 for (; i <= fi_args->max_id; ++i) {
1739 BUG_ON(ndevs >= fi_args->num_devices);
1740 ret = get_device_info(fd, i, &di_args[ndevs]);
1741 if (ret == -ENODEV)
1742 continue;
1743 if (ret)
1744 goto out;
1745 ndevs++;
1746 }
1747
1748 /*
1749 * only when the only dev we wanted to find is not there then
1750 * let any error be returned
1751 */
1752 if (fi_args->num_devices != 1) {
1753 BUG_ON(ndevs == 0);
1754 ret = 0;
1755 }
1756
1757 out:
1758 close_file_or_dir(fd, dirstream);
1759 return ret;
1760 }
1761
1762 #define isoctal(c) (((c) & ~7) == '0')
1763
1764 static inline void translate(char *f, char *t)
1765 {
1766 while (*f != '\0') {
1767 if (*f == '\\' &&
1768 isoctal(f[1]) && isoctal(f[2]) && isoctal(f[3])) {
1769 *t++ = 64*(f[1] & 7) + 8*(f[2] & 7) + (f[3] & 7);
1770 f += 4;
1771 } else
1772 *t++ = *f++;
1773 }
1774 *t = '\0';
1775 return;
1776 }
1777
1778 /*
1779 * Checks if the swap device.
1780 * Returns 1 if swap device, < 0 on error or 0 if not swap device.
1781 */
1782 static int is_swap_device(const char *file)
1783 {
1784 FILE *f;
1785 struct stat st_buf;
1786 dev_t dev;
1787 ino_t ino = 0;
1788 char tmp[PATH_MAX];
1789 char buf[PATH_MAX];
1790 char *cp;
1791 int ret = 0;
1792
1793 if (stat(file, &st_buf) < 0)
1794 return -errno;
1795 if (S_ISBLK(st_buf.st_mode))
1796 dev = st_buf.st_rdev;
1797 else if (S_ISREG(st_buf.st_mode)) {
1798 dev = st_buf.st_dev;
1799 ino = st_buf.st_ino;
1800 } else
1801 return 0;
1802
1803 if ((f = fopen("/proc/swaps", "r")) == NULL)
1804 return 0;
1805
1806 /* skip the first line */
1807 if (fgets(tmp, sizeof(tmp), f) == NULL)
1808 goto out;
1809
1810 while (fgets(tmp, sizeof(tmp), f) != NULL) {
1811 if ((cp = strchr(tmp, ' ')) != NULL)
1812 *cp = '\0';
1813 if ((cp = strchr(tmp, '\t')) != NULL)
1814 *cp = '\0';
1815 translate(tmp, buf);
1816 if (stat(buf, &st_buf) != 0)
1817 continue;
1818 if (S_ISBLK(st_buf.st_mode)) {
1819 if (dev == st_buf.st_rdev) {
1820 ret = 1;
1821 break;
1822 }
1823 } else if (S_ISREG(st_buf.st_mode)) {
1824 if (dev == st_buf.st_dev && ino == st_buf.st_ino) {
1825 ret = 1;
1826 break;
1827 }
1828 }
1829 }
1830
1831 out:
1832 fclose(f);
1833
1834 return ret;
1835 }
1836
1837 /*
1838 * Check for existing filesystem or partition table on device.
1839 * Returns:
1840 * 1 for existing fs or partition
1841 * 0 for nothing found
1842 * -1 for internal error
1843 */
1844 static int
1845 check_overwrite(
1846 char *device)
1847 {
1848 const char *type;
1849 blkid_probe pr = NULL;
1850 int ret;
1851 blkid_loff_t size;
1852
1853 if (!device || !*device)
1854 return 0;
1855
1856 ret = -1; /* will reset on success of all setup calls */
1857
1858 pr = blkid_new_probe_from_filename(device);
1859 if (!pr)
1860 goto out;
1861
1862 size = blkid_probe_get_size(pr);
1863 if (size < 0)
1864 goto out;
1865
1866 /* nothing to overwrite on a 0-length device */
1867 if (size == 0) {
1868 ret = 0;
1869 goto out;
1870 }
1871
1872 ret = blkid_probe_enable_partitions(pr, 1);
1873 if (ret < 0)
1874 goto out;
1875
1876 ret = blkid_do_fullprobe(pr);
1877 if (ret < 0)
1878 goto out;
1879
1880 /*
1881 * Blkid returns 1 for nothing found and 0 when it finds a signature,
1882 * but we want the exact opposite, so reverse the return value here.
1883 *
1884 * In addition print some useful diagnostics about what actually is
1885 * on the device.
1886 */
1887 if (ret) {
1888 ret = 0;
1889 goto out;
1890 }
1891
1892 if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
1893 fprintf(stderr,
1894 "%s appears to contain an existing "
1895 "filesystem (%s).\n", device, type);
1896 } else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
1897 fprintf(stderr,
1898 "%s appears to contain a partition "
1899 "table (%s).\n", device, type);
1900 } else {
1901 fprintf(stderr,
1902 "%s appears to contain something weird "
1903 "according to blkid\n", device);
1904 }
1905 ret = 1;
1906
1907 out:
1908 if (pr)
1909 blkid_free_probe(pr);
1910 if (ret == -1)
1911 fprintf(stderr,
1912 "probe of %s failed, cannot detect "
1913 "existing filesystem.\n", device);
1914 return ret;
1915 }
1916
1917 int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
1918 u64 dev_cnt, int mixed, char *estr)
1919 {
1920 size_t sz = 100;
1921 u64 allowed = 0;
1922
1923 switch (dev_cnt) {
1924 default:
1925 case 4:
1926 allowed |= BTRFS_BLOCK_GROUP_RAID10;
1927 case 3:
1928 allowed |= BTRFS_BLOCK_GROUP_RAID6;
1929 case 2:
1930 allowed |= BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1931 BTRFS_BLOCK_GROUP_RAID5;
1932 break;
1933 case 1:
1934 allowed |= BTRFS_BLOCK_GROUP_DUP;
1935 }
1936
1937 if (metadata_profile & ~allowed) {
1938 snprintf(estr, sz, "unable to create FS with metadata "
1939 "profile %llu (have %llu devices)\n",
1940 metadata_profile, dev_cnt);
1941 return 1;
1942 }
1943 if (data_profile & ~allowed) {
1944 snprintf(estr, sz, "unable to create FS with data "
1945 "profile %llu (have %llu devices)\n",
1946 metadata_profile, dev_cnt);
1947 return 1;
1948 }
1949
1950 if (!mixed && (data_profile & BTRFS_BLOCK_GROUP_DUP)) {
1951 snprintf(estr, sz,
1952 "dup for data is allowed only in mixed mode");
1953 return 1;
1954 }
1955 return 0;
1956 }
1957
1958 /* Check if disk is suitable for btrfs
1959 * returns:
1960 * 1: something is wrong, estr provides the error
1961 * 0: all is fine
1962 */
1963 int test_dev_for_mkfs(char *file, int force_overwrite, char *estr)
1964 {
1965 int ret, fd;
1966 size_t sz = 100;
1967 struct stat st;
1968
1969 ret = is_swap_device(file);
1970 if (ret < 0) {
1971 snprintf(estr, sz, "error checking %s status: %s\n", file,
1972 strerror(-ret));
1973 return 1;
1974 }
1975 if (ret == 1) {
1976 snprintf(estr, sz, "%s is a swap device\n", file);
1977 return 1;
1978 }
1979 if (!force_overwrite) {
1980 if (check_overwrite(file)) {
1981 snprintf(estr, sz, "Use the -f option to force overwrite.\n");
1982 return 1;
1983 }
1984 }
1985 ret = check_mounted(file);
1986 if (ret < 0) {
1987 snprintf(estr, sz, "error checking %s mount status\n",
1988 file);
1989 return 1;
1990 }
1991 if (ret == 1) {
1992 snprintf(estr, sz, "%s is mounted\n", file);
1993 return 1;
1994 }
1995 /* check if the device is busy */
1996 fd = open(file, O_RDWR|O_EXCL);
1997 if (fd < 0) {
1998 snprintf(estr, sz, "unable to open %s: %s\n", file,
1999 strerror(errno));
2000 return 1;
2001 }
2002 if (fstat(fd, &st)) {
2003 snprintf(estr, sz, "unable to stat %s: %s\n", file,
2004 strerror(errno));
2005 close(fd);
2006 return 1;
2007 }
2008 if (!S_ISBLK(st.st_mode)) {
2009 fprintf(stderr, "'%s' is not a block device\n", file);
2010 close(fd);
2011 return 1;
2012 }
2013 close(fd);
2014 return 0;
2015 }
2016
2017 int btrfs_scan_lblkid(int update_kernel)
2018 {
2019 int fd = -1;
2020 int ret;
2021 u64 num_devices;
2022 struct btrfs_fs_devices *tmp_devices;
2023 blkid_dev_iterate iter = NULL;
2024 blkid_dev dev = NULL;
2025 blkid_cache cache = NULL;
2026 char path[PATH_MAX];
2027
2028 if (blkid_get_cache(&cache, 0) < 0) {
2029 printf("ERROR: lblkid cache get failed\n");
2030 return 1;
2031 }
2032 blkid_probe_all(cache);
2033 iter = blkid_dev_iterate_begin(cache);
2034 blkid_dev_set_search(iter, "TYPE", "btrfs");
2035 while (blkid_dev_next(iter, &dev) == 0) {
2036 dev = blkid_verify(cache, dev);
2037 if (!dev)
2038 continue;
2039 /* if we are here its definitely a btrfs disk*/
2040 strncpy(path, blkid_dev_devname(dev), PATH_MAX);
2041
2042 fd = open(path, O_RDONLY);
2043 if (fd < 0) {
2044 printf("ERROR: could not open %s\n", path);
2045 continue;
2046 }
2047 ret = btrfs_scan_one_device(fd, path, &tmp_devices,
2048 &num_devices, BTRFS_SUPER_INFO_OFFSET);
2049 if (ret) {
2050 printf("ERROR: could not scan %s\n", path);
2051 close (fd);
2052 continue;
2053 }
2054
2055 close(fd);
2056 if (update_kernel)
2057 btrfs_register_one_device(path);
2058 }
2059 blkid_dev_iterate_end(iter);
2060 blkid_put_cache(cache);
2061 return 0;
2062 }
2063
2064 /*
2065 * scans devs for the btrfs
2066 */
2067 int scan_for_btrfs(int where, int update_kernel)
2068 {
2069 int ret = 0;
2070
2071 switch (where) {
2072 case BTRFS_SCAN_PROC:
2073 ret = btrfs_scan_block_devices(update_kernel);
2074 break;
2075 case BTRFS_SCAN_DEV:
2076 ret = btrfs_scan_one_dir("/dev", update_kernel);
2077 break;
2078 case BTRFS_SCAN_LBLKID:
2079 ret = btrfs_scan_lblkid(update_kernel);
2080 break;
2081 }
2082 return ret;
2083 }
2084
2085 int is_vol_small(char *file)
2086 {
2087 int fd = -1;
2088 int e;
2089 struct stat st;
2090 u64 size;
2091
2092 fd = open(file, O_RDONLY);
2093 if (fd < 0)
2094 return -errno;
2095 if (fstat(fd, &st) < 0) {
2096 e = -errno;
2097 close(fd);
2098 return e;
2099 }
2100 size = btrfs_device_size(fd, &st);
2101 if (size == 0) {
2102 close(fd);
2103 return -1;
2104 }
2105 if (size < 1024 * 1024 * 1024) {
2106 close(fd);
2107 return 1;
2108 } else {
2109 close(fd);
2110 return 0;
2111 }
2112 }
2113
2114 /*
2115 * This reads a line from the stdin and only returns non-zero if the
2116 * first whitespace delimited token is a case insensitive match with yes
2117 * or y.
2118 */
2119 int ask_user(char *question)
2120 {
2121 char buf[30] = {0,};
2122 char *saveptr = NULL;
2123 char *answer;
2124
2125 printf("%s [y/N]: ", question);
2126
2127 return fgets(buf, sizeof(buf) - 1, stdin) &&
2128 (answer = strtok_r(buf, " \t\n\r", &saveptr)) &&
2129 (!strcasecmp(answer, "yes") || !strcasecmp(answer, "y"));
2130 }
2131
2132 /*
2133 * For a given:
2134 * - file or directory return the containing tree root id
2135 * - subvolume return it's own tree id
2136 * - BTRFS_EMPTY_SUBVOL_DIR_OBJECTID (directory with ino == 2) the result is
2137 * undefined and function returns -1
2138 */
2139 int lookup_ino_rootid(int fd, u64 *rootid)
2140 {
2141 struct btrfs_ioctl_ino_lookup_args args;
2142 int ret;
2143 int e;
2144
2145 memset(&args, 0, sizeof(args));
2146 args.treeid = 0;
2147 args.objectid = BTRFS_FIRST_FREE_OBJECTID;
2148
2149 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
2150 e = errno;
2151 if (ret) {
2152 fprintf(stderr, "ERROR: Failed to lookup root id - %s\n",
2153 strerror(e));
2154 return ret;
2155 }
2156
2157 *rootid = args.treeid;
2158
2159 return 0;
2160 }
2161
2162 int find_mount_root(const char *path, char **mount_root)
2163 {
2164 FILE *mnttab;
2165 int fd;
2166 struct mntent *ent;
2167 int len;
2168 int ret;
2169 int longest_matchlen = 0;
2170 char *longest_match = NULL;
2171
2172 fd = open(path, O_RDONLY | O_NOATIME);
2173 if (fd < 0)
2174 return -errno;
2175 close(fd);
2176
2177 mnttab = setmntent("/proc/self/mounts", "r");
2178 if (!mnttab)
2179 return -errno;
2180
2181 while ((ent = getmntent(mnttab))) {
2182 len = strlen(ent->mnt_dir);
2183 if (strncmp(ent->mnt_dir, path, len) == 0) {
2184 /* match found */
2185 if (longest_matchlen < len) {
2186 free(longest_match);
2187 longest_matchlen = len;
2188 longest_match = strdup(ent->mnt_dir);
2189 }
2190 }
2191 }
2192 endmntent(mnttab);
2193
2194 if (!longest_match) {
2195 fprintf(stderr,
2196 "ERROR: Failed to find mount root for path %s.\n",
2197 path);
2198 return -ENOENT;
2199 }
2200
2201 ret = 0;
2202 *mount_root = realpath(longest_match, NULL);
2203 if (!*mount_root)
2204 ret = -errno;
2205
2206 free(longest_match);
2207 return ret;
2208 }
(deprecated) Btrfs progs developments and patch integration