2 * Copyright (C) 2007 Oracle. All rights reserved.
3 * Copyright (C) 2008 Morey Roof. All rights reserved.
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.
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.
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.
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 */
27 #include <sys/ioctl.h>
28 #include <sys/mount.h>
29 #include <sys/types.h>
31 #include <uuid/uuid.h>
36 #include <linux/loop.h>
37 #include <linux/major.h>
38 #include <linux/kdev_t.h>
40 #include <blkid/blkid.h>
41 #include "kerncompat.h"
42 #include "radix-tree.h"
45 #include "transaction.h"
52 #define BLKDISCARD _IO(0x12,119)
56 discard_blocks(int fd, u64 start, u64 len)
58 u64 range[2] = { start, len };
60 if (ioctl(fd, BLKDISCARD, &range) < 0)
65 static u64 reference_root_table[] = {
66 [1] = BTRFS_ROOT_TREE_OBJECTID,
67 [2] = BTRFS_EXTENT_TREE_OBJECTID,
68 [3] = BTRFS_CHUNK_TREE_OBJECTID,
69 [4] = BTRFS_DEV_TREE_OBJECTID,
70 [5] = BTRFS_FS_TREE_OBJECTID,
71 [6] = BTRFS_CSUM_TREE_OBJECTID,
74 int make_btrfs(int fd, const char *device, const char *label,
75 u64 blocks[7], u64 num_bytes, u32 nodesize,
76 u32 leafsize, u32 sectorsize, u32 stripesize)
78 struct btrfs_super_block super;
79 struct extent_buffer *buf;
80 struct btrfs_root_item root_item;
81 struct btrfs_disk_key disk_key;
82 struct btrfs_extent_item *extent_item;
83 struct btrfs_inode_item *inode_item;
84 struct btrfs_chunk *chunk;
85 struct btrfs_dev_item *dev_item;
86 struct btrfs_dev_extent *dev_extent;
87 u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
98 first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
99 first_free &= ~((u64)sectorsize - 1);
101 memset(&super, 0, sizeof(super));
103 num_bytes = (num_bytes / sectorsize) * sectorsize;
104 uuid_generate(super.fsid);
105 uuid_generate(super.dev_item.uuid);
106 uuid_generate(chunk_tree_uuid);
108 btrfs_set_super_bytenr(&super, blocks[0]);
109 btrfs_set_super_num_devices(&super, 1);
110 btrfs_set_super_magic(&super, BTRFS_MAGIC);
111 btrfs_set_super_generation(&super, 1);
112 btrfs_set_super_root(&super, blocks[1]);
113 btrfs_set_super_chunk_root(&super, blocks[3]);
114 btrfs_set_super_total_bytes(&super, num_bytes);
115 btrfs_set_super_bytes_used(&super, 6 * leafsize);
116 btrfs_set_super_sectorsize(&super, sectorsize);
117 btrfs_set_super_leafsize(&super, leafsize);
118 btrfs_set_super_nodesize(&super, nodesize);
119 btrfs_set_super_stripesize(&super, stripesize);
120 btrfs_set_super_csum_type(&super, BTRFS_CSUM_TYPE_CRC32);
121 btrfs_set_super_chunk_root_generation(&super, 1);
122 btrfs_set_super_cache_generation(&super, -1);
124 strncpy(super.label, label, BTRFS_LABEL_SIZE - 1);
126 buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));
128 /* create the tree of root objects */
129 memset(buf->data, 0, leafsize);
131 btrfs_set_header_bytenr(buf, blocks[1]);
132 btrfs_set_header_nritems(buf, 4);
133 btrfs_set_header_generation(buf, 1);
134 btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
135 btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
136 write_extent_buffer(buf, super.fsid, (unsigned long)
137 btrfs_header_fsid(buf), BTRFS_FSID_SIZE);
139 write_extent_buffer(buf, chunk_tree_uuid, (unsigned long)
140 btrfs_header_chunk_tree_uuid(buf),
143 /* create the items for the root tree */
144 memset(&root_item, 0, sizeof(root_item));
145 inode_item = &root_item.inode;
146 btrfs_set_stack_inode_generation(inode_item, 1);
147 btrfs_set_stack_inode_size(inode_item, 3);
148 btrfs_set_stack_inode_nlink(inode_item, 1);
149 btrfs_set_stack_inode_nbytes(inode_item, leafsize);
150 btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
151 btrfs_set_root_refs(&root_item, 1);
152 btrfs_set_root_used(&root_item, leafsize);
153 btrfs_set_root_generation(&root_item, 1);
155 memset(&disk_key, 0, sizeof(disk_key));
156 btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
157 btrfs_set_disk_key_offset(&disk_key, 0);
160 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
161 btrfs_set_root_bytenr(&root_item, blocks[2]);
162 btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
163 btrfs_set_item_key(buf, &disk_key, nritems);
164 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
165 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
167 write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,
168 nritems), sizeof(root_item));
171 itemoff = itemoff - sizeof(root_item);
172 btrfs_set_root_bytenr(&root_item, blocks[4]);
173 btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);
174 btrfs_set_item_key(buf, &disk_key, nritems);
175 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
176 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
178 write_extent_buffer(buf, &root_item,
179 btrfs_item_ptr_offset(buf, nritems),
183 itemoff = itemoff - sizeof(root_item);
184 btrfs_set_root_bytenr(&root_item, blocks[5]);
185 btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
186 btrfs_set_item_key(buf, &disk_key, nritems);
187 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
188 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
190 write_extent_buffer(buf, &root_item,
191 btrfs_item_ptr_offset(buf, nritems),
195 itemoff = itemoff - sizeof(root_item);
196 btrfs_set_root_bytenr(&root_item, blocks[6]);
197 btrfs_set_disk_key_objectid(&disk_key, BTRFS_CSUM_TREE_OBJECTID);
198 btrfs_set_item_key(buf, &disk_key, nritems);
199 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
200 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
202 write_extent_buffer(buf, &root_item,
203 btrfs_item_ptr_offset(buf, nritems),
208 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
209 ret = pwrite(fd, buf->data, leafsize, blocks[1]);
212 else if (ret != leafsize)
215 /* create the items for the extent tree */
216 memset(buf->data+sizeof(struct btrfs_header), 0,
217 leafsize-sizeof(struct btrfs_header));
219 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize);
220 for (i = 1; i < 7; i++) {
221 BUG_ON(blocks[i] < first_free);
222 BUG_ON(blocks[i] < blocks[i - 1]);
224 /* create extent item */
225 itemoff -= sizeof(struct btrfs_extent_item) +
226 sizeof(struct btrfs_tree_block_info);
227 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
228 btrfs_set_disk_key_offset(&disk_key, leafsize);
229 btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
230 btrfs_set_item_key(buf, &disk_key, nritems);
231 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
233 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
234 sizeof(struct btrfs_extent_item) +
235 sizeof(struct btrfs_tree_block_info));
236 extent_item = btrfs_item_ptr(buf, nritems,
237 struct btrfs_extent_item);
238 btrfs_set_extent_refs(buf, extent_item, 1);
239 btrfs_set_extent_generation(buf, extent_item, 1);
240 btrfs_set_extent_flags(buf, extent_item,
241 BTRFS_EXTENT_FLAG_TREE_BLOCK);
244 /* create extent ref */
245 ref_root = reference_root_table[i];
246 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
247 btrfs_set_disk_key_offset(&disk_key, ref_root);
248 btrfs_set_disk_key_type(&disk_key, BTRFS_TREE_BLOCK_REF_KEY);
249 btrfs_set_item_key(buf, &disk_key, nritems);
250 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
252 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), 0);
255 btrfs_set_header_bytenr(buf, blocks[2]);
256 btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
257 btrfs_set_header_nritems(buf, nritems);
258 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
259 ret = pwrite(fd, buf->data, leafsize, blocks[2]);
262 else if (ret != leafsize)
265 /* create the chunk tree */
266 memset(buf->data+sizeof(struct btrfs_header), 0,
267 leafsize-sizeof(struct btrfs_header));
269 item_size = sizeof(*dev_item);
270 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - item_size;
272 /* first device 1 (there is no device 0) */
273 btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
274 btrfs_set_disk_key_offset(&disk_key, 1);
275 btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
276 btrfs_set_item_key(buf, &disk_key, nritems);
277 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
278 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);
280 dev_item = btrfs_item_ptr(buf, nritems, struct btrfs_dev_item);
281 btrfs_set_device_id(buf, dev_item, 1);
282 btrfs_set_device_generation(buf, dev_item, 0);
283 btrfs_set_device_total_bytes(buf, dev_item, num_bytes);
284 btrfs_set_device_bytes_used(buf, dev_item,
285 BTRFS_MKFS_SYSTEM_GROUP_SIZE);
286 btrfs_set_device_io_align(buf, dev_item, sectorsize);
287 btrfs_set_device_io_width(buf, dev_item, sectorsize);
288 btrfs_set_device_sector_size(buf, dev_item, sectorsize);
289 btrfs_set_device_type(buf, dev_item, 0);
291 write_extent_buffer(buf, super.dev_item.uuid,
292 (unsigned long)btrfs_device_uuid(dev_item),
294 write_extent_buffer(buf, super.fsid,
295 (unsigned long)btrfs_device_fsid(dev_item),
297 read_extent_buffer(buf, &super.dev_item, (unsigned long)dev_item,
301 item_size = btrfs_chunk_item_size(1);
302 itemoff = itemoff - item_size;
304 /* then we have chunk 0 */
305 btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
306 btrfs_set_disk_key_offset(&disk_key, 0);
307 btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
308 btrfs_set_item_key(buf, &disk_key, nritems);
309 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
310 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);
312 chunk = btrfs_item_ptr(buf, nritems, struct btrfs_chunk);
313 btrfs_set_chunk_length(buf, chunk, BTRFS_MKFS_SYSTEM_GROUP_SIZE);
314 btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
315 btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);
316 btrfs_set_chunk_type(buf, chunk, BTRFS_BLOCK_GROUP_SYSTEM);
317 btrfs_set_chunk_io_align(buf, chunk, sectorsize);
318 btrfs_set_chunk_io_width(buf, chunk, sectorsize);
319 btrfs_set_chunk_sector_size(buf, chunk, sectorsize);
320 btrfs_set_chunk_num_stripes(buf, chunk, 1);
321 btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
322 btrfs_set_stripe_offset_nr(buf, chunk, 0, 0);
325 write_extent_buffer(buf, super.dev_item.uuid,
326 (unsigned long)btrfs_stripe_dev_uuid(&chunk->stripe),
329 /* copy the key for the chunk to the system array */
330 ptr = super.sys_chunk_array;
331 array_size = sizeof(disk_key);
333 memcpy(ptr, &disk_key, sizeof(disk_key));
334 ptr += sizeof(disk_key);
336 /* copy the chunk to the system array */
337 read_extent_buffer(buf, ptr, (unsigned long)chunk, item_size);
338 array_size += item_size;
340 btrfs_set_super_sys_array_size(&super, array_size);
342 btrfs_set_header_bytenr(buf, blocks[3]);
343 btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);
344 btrfs_set_header_nritems(buf, nritems);
345 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
346 ret = pwrite(fd, buf->data, leafsize, blocks[3]);
349 else if (ret != leafsize)
352 /* create the device tree */
353 memset(buf->data+sizeof(struct btrfs_header), 0,
354 leafsize-sizeof(struct btrfs_header));
356 itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
357 sizeof(struct btrfs_dev_extent);
359 btrfs_set_disk_key_objectid(&disk_key, 1);
360 btrfs_set_disk_key_offset(&disk_key, 0);
361 btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
362 btrfs_set_item_key(buf, &disk_key, nritems);
363 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
364 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
365 sizeof(struct btrfs_dev_extent));
366 dev_extent = btrfs_item_ptr(buf, nritems, struct btrfs_dev_extent);
367 btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
368 BTRFS_CHUNK_TREE_OBJECTID);
369 btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
370 BTRFS_FIRST_CHUNK_TREE_OBJECTID);
371 btrfs_set_dev_extent_chunk_offset(buf, dev_extent, 0);
373 write_extent_buffer(buf, chunk_tree_uuid,
374 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(dev_extent),
377 btrfs_set_dev_extent_length(buf, dev_extent,
378 BTRFS_MKFS_SYSTEM_GROUP_SIZE);
381 btrfs_set_header_bytenr(buf, blocks[4]);
382 btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);
383 btrfs_set_header_nritems(buf, nritems);
384 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
385 ret = pwrite(fd, buf->data, leafsize, blocks[4]);
388 else if (ret != leafsize)
391 /* create the FS root */
392 memset(buf->data+sizeof(struct btrfs_header), 0,
393 leafsize-sizeof(struct btrfs_header));
394 btrfs_set_header_bytenr(buf, blocks[5]);
395 btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
396 btrfs_set_header_nritems(buf, 0);
397 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
398 ret = pwrite(fd, buf->data, leafsize, blocks[5]);
401 else if (ret != leafsize)
404 /* finally create the csum root */
405 memset(buf->data+sizeof(struct btrfs_header), 0,
406 leafsize-sizeof(struct btrfs_header));
407 btrfs_set_header_bytenr(buf, blocks[6]);
408 btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);
409 btrfs_set_header_nritems(buf, 0);
410 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
411 ret = pwrite(fd, buf->data, leafsize, blocks[6]);
414 else if (ret != leafsize)
417 /* and write out the super block */
418 BUG_ON(sizeof(super) > sectorsize);
419 memset(buf->data, 0, sectorsize);
420 memcpy(buf->data, &super, sizeof(super));
421 buf->len = sectorsize;
422 csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
423 ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
426 else if (ret != sectorsize)
433 u64 btrfs_device_size(int fd, struct stat *st)
436 if (S_ISREG(st->st_mode)) {
439 if (!S_ISBLK(st->st_mode)) {
442 if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
448 static int zero_blocks(int fd, off_t start, size_t len)
450 char *buf = malloc(len);
457 written = pwrite(fd, buf, len, start);
464 static int zero_dev_start(int fd)
467 size_t len = 2 * 1024 * 1024;
470 /* don't overwrite the disk labels on sparc */
474 return zero_blocks(fd, start, len);
477 static int zero_dev_end(int fd, u64 dev_size)
479 size_t len = 2 * 1024 * 1024;
480 off_t start = dev_size - len;
482 return zero_blocks(fd, start, len);
485 int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
486 struct btrfs_root *root, int fd, char *path,
487 u64 block_count, u32 io_width, u32 io_align,
490 struct btrfs_super_block *disk_super;
491 struct btrfs_super_block *super = root->fs_info->super_copy;
492 struct btrfs_device *device;
493 struct btrfs_dev_item *dev_item;
499 device = kzalloc(sizeof(*device), GFP_NOFS);
502 buf = kmalloc(sectorsize, GFP_NOFS);
507 BUG_ON(sizeof(*disk_super) > sectorsize);
508 memset(buf, 0, sectorsize);
510 disk_super = (struct btrfs_super_block *)buf;
511 dev_item = &disk_super->dev_item;
513 uuid_generate(device->uuid);
516 device->io_width = io_width;
517 device->io_align = io_align;
518 device->sector_size = sectorsize;
520 device->writeable = 1;
521 device->total_bytes = block_count;
522 device->bytes_used = 0;
523 device->total_ios = 0;
524 device->dev_root = root->fs_info->dev_root;
526 ret = btrfs_add_device(trans, root, device);
529 total_bytes = btrfs_super_total_bytes(super) + block_count;
530 btrfs_set_super_total_bytes(super, total_bytes);
532 num_devs = btrfs_super_num_devices(super) + 1;
533 btrfs_set_super_num_devices(super, num_devs);
535 memcpy(disk_super, super, sizeof(*disk_super));
537 printf("adding device %s id %llu\n", path,
538 (unsigned long long)device->devid);
540 btrfs_set_super_bytenr(disk_super, BTRFS_SUPER_INFO_OFFSET);
541 btrfs_set_stack_device_id(dev_item, device->devid);
542 btrfs_set_stack_device_type(dev_item, device->type);
543 btrfs_set_stack_device_io_align(dev_item, device->io_align);
544 btrfs_set_stack_device_io_width(dev_item, device->io_width);
545 btrfs_set_stack_device_sector_size(dev_item, device->sector_size);
546 btrfs_set_stack_device_total_bytes(dev_item, device->total_bytes);
547 btrfs_set_stack_device_bytes_used(dev_item, device->bytes_used);
548 memcpy(&dev_item->uuid, device->uuid, BTRFS_UUID_SIZE);
550 ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
551 BUG_ON(ret != sectorsize);
554 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
555 device->fs_devices = root->fs_info->fs_devices;
559 int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret,
560 u64 max_block_count, int *mixed, int nodiscard)
567 ret = fstat(fd, &st);
569 fprintf(stderr, "unable to stat %s\n", file);
573 block_count = btrfs_device_size(fd, &st);
574 if (block_count == 0) {
575 fprintf(stderr, "unable to find %s size\n", file);
579 block_count = min(block_count, max_block_count);
582 if (block_count < 1024 * 1024 * 1024 && !(*mixed)) {
583 printf("SMALL VOLUME: forcing mixed metadata/data groups\n");
589 * We intentionally ignore errors from the discard ioctl. It is
590 * not necessary for the mkfs functionality but just an optimization.
592 discard_blocks(fd, 0, block_count);
595 ret = zero_dev_start(fd);
597 fprintf(stderr, "failed to zero device start %d\n", ret);
601 for (i = 0 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {
602 bytenr = btrfs_sb_offset(i);
603 if (bytenr >= block_count)
605 zero_blocks(fd, bytenr, BTRFS_SUPER_INFO_SIZE);
609 ret = zero_dev_end(fd, block_count);
611 fprintf(stderr, "failed to zero device end %d\n", ret);
615 *block_count_ret = block_count;
619 int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
620 struct btrfs_root *root, u64 objectid)
623 struct btrfs_inode_item inode_item;
624 time_t now = time(NULL);
626 memset(&inode_item, 0, sizeof(inode_item));
627 btrfs_set_stack_inode_generation(&inode_item, trans->transid);
628 btrfs_set_stack_inode_size(&inode_item, 0);
629 btrfs_set_stack_inode_nlink(&inode_item, 1);
630 btrfs_set_stack_inode_nbytes(&inode_item, root->leafsize);
631 btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);
632 btrfs_set_stack_timespec_sec(&inode_item.atime, now);
633 btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);
634 btrfs_set_stack_timespec_sec(&inode_item.ctime, now);
635 btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);
636 btrfs_set_stack_timespec_sec(&inode_item.mtime, now);
637 btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);
638 btrfs_set_stack_timespec_sec(&inode_item.otime, 0);
639 btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);
641 if (root->fs_info->tree_root == root)
642 btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);
644 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
648 ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);
652 btrfs_set_root_dirid(&root->root_item, objectid);
659 * checks if a path is a block device node
660 * Returns negative errno on failure, otherwise
661 * returns 1 for blockdev, 0 for not-blockdev
663 int is_block_device(const char *path) {
666 if (stat(path, &statbuf) < 0)
669 return S_ISBLK(statbuf.st_mode);
673 * Find the mount point for a mounted device.
674 * On success, returns 0 with mountpoint in *mp.
675 * On failure, returns -errno (not mounted yields -EINVAL)
676 * Is noisy on failures, expects to be given a mounted device.
678 static int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {
682 ret = is_block_device(dev);
685 fprintf(stderr, "%s is not a block device\n", dev);
688 fprintf(stderr, "Could not check %s: %s\n",
689 dev, strerror(-ret));
694 fd = open(dev, O_RDONLY);
697 fprintf(stderr, "Could not open %s: %s\n", dev, strerror(errno));
701 ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
703 fprintf(stderr, "%s is not a mounted btrfs device\n", dev);
705 } else { /* mounted, all good */
712 fprintf(stderr, "Could not get mountpoint for %s\n", dev);
717 * Given a pathname, return a filehandle to:
718 * the original pathname or,
719 * if the pathname is a mounted btrfs device, to its mountpoint.
721 * On error, return -1, errno should be set.
723 int open_path_or_dev_mnt(const char *path, DIR **dirstream)
725 char mp[BTRFS_PATH_NAME_MAX + 1];
728 if (is_block_device(path)) {
731 ret = get_btrfs_mount(path, mp, sizeof(mp));
733 /* not a mounted btrfs dev */
737 fdmnt = open_file_or_dir(mp, dirstream);
739 fdmnt = open_file_or_dir(path, dirstream);
745 /* checks if a device is a loop device */
746 static int is_loop_device (const char* device) {
749 if(stat(device, &statbuf) < 0)
752 return (S_ISBLK(statbuf.st_mode) &&
753 MAJOR(statbuf.st_rdev) == LOOP_MAJOR);
757 /* Takes a loop device path (e.g. /dev/loop0) and returns
758 * the associated file (e.g. /images/my_btrfs.img) */
759 static int resolve_loop_device(const char* loop_dev, char* loop_file,
766 char real_loop_dev[PATH_MAX];
768 if (!realpath(loop_dev, real_loop_dev))
770 snprintf(p, PATH_MAX, "/sys/block/%s/loop/backing_file", strrchr(real_loop_dev, '/'));
771 if (!(f = fopen(p, "r")))
774 snprintf(fmt, 20, "%%%i[^\n]", max_len-1);
775 ret = fscanf(f, fmt, loop_file);
783 /* Checks whether a and b are identical or device
784 * files associated with the same block device
786 static int is_same_blk_file(const char* a, const char* b)
788 struct stat st_buf_a, st_buf_b;
789 char real_a[PATH_MAX];
790 char real_b[PATH_MAX];
792 if(!realpath(a, real_a) ||
793 !realpath(b, real_b))
798 /* Identical path? */
799 if(strcmp(real_a, real_b) == 0)
802 if(stat(a, &st_buf_a) < 0 ||
803 stat(b, &st_buf_b) < 0)
810 /* Same blockdevice? */
811 if(S_ISBLK(st_buf_a.st_mode) &&
812 S_ISBLK(st_buf_b.st_mode) &&
813 st_buf_a.st_rdev == st_buf_b.st_rdev)
819 if (st_buf_a.st_dev == st_buf_b.st_dev &&
820 st_buf_a.st_ino == st_buf_b.st_ino)
828 /* checks if a and b are identical or device
829 * files associated with the same block device or
830 * if one file is a loop device that uses the other
833 static int is_same_loop_file(const char* a, const char* b)
835 char res_a[PATH_MAX];
836 char res_b[PATH_MAX];
841 /* Resolve a if it is a loop device */
842 if((ret = is_loop_device(a)) < 0) {
847 if ((ret = resolve_loop_device(a, res_a, sizeof(res_a))) < 0)
855 /* Resolve b if it is a loop device */
856 if ((ret = is_loop_device(b)) < 0) {
861 if((ret = resolve_loop_device(b, res_b, sizeof(res_b))) < 0)
869 return is_same_blk_file(final_a, final_b);
872 /* Checks if a file exists and is a block or regular file*/
873 static int is_existing_blk_or_reg_file(const char* filename)
877 if(stat(filename, &st_buf) < 0) {
884 return (S_ISBLK(st_buf.st_mode) || S_ISREG(st_buf.st_mode));
887 /* Checks if a file is used (directly or indirectly via a loop device)
888 * by a device in fs_devices
890 static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices,
894 struct list_head *head;
895 struct list_head *cur;
896 struct btrfs_device *device;
898 head = &fs_devices->devices;
899 list_for_each(cur, head) {
900 device = list_entry(cur, struct btrfs_device, dev_list);
902 if((ret = is_same_loop_file(device->name, file)))
910 * returns 1 if the device was mounted, < 0 on error or 0 if everything
911 * is safe to continue.
913 int check_mounted(const char* file)
918 fd = open(file, O_RDONLY);
920 fprintf (stderr, "check_mounted(): Could not open %s\n", file);
924 ret = check_mounted_where(fd, file, NULL, 0, NULL);
930 int check_mounted_where(int fd, const char *file, char *where, int size,
931 struct btrfs_fs_devices **fs_dev_ret)
936 struct btrfs_fs_devices *fs_devices_mnt = NULL;
940 /* scan the initial device */
941 ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
942 &total_devs, BTRFS_SUPER_INFO_OFFSET);
943 is_btrfs = (ret >= 0);
945 /* scan other devices */
946 if (is_btrfs && total_devs > 1) {
947 if((ret = btrfs_scan_for_fsid(1)))
951 /* iterate over the list of currently mountes filesystems */
952 if ((f = setmntent ("/proc/mounts", "r")) == NULL)
955 while ((mnt = getmntent (f)) != NULL) {
957 if(strcmp(mnt->mnt_type, "btrfs") != 0)
960 ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname);
962 /* ignore entries in the mount table that are not
963 associated with a file*/
964 if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0)
965 goto out_mntloop_err;
969 ret = is_same_loop_file(file, mnt->mnt_fsname);
973 goto out_mntloop_err;
978 /* Did we find an entry in mnt table? */
979 if (mnt && size && where) {
980 strncpy(where, mnt->mnt_dir, size);
984 *fs_dev_ret = fs_devices_mnt;
995 struct list_head list;
999 void btrfs_register_one_device(char *fname)
1001 struct btrfs_ioctl_vol_args args;
1006 fd = open("/dev/btrfs-control", O_RDONLY);
1008 fprintf(stderr, "failed to open /dev/btrfs-control "
1009 "skipping device registration: %s\n",
1013 strncpy(args.name, fname, BTRFS_PATH_NAME_MAX);
1014 args.name[BTRFS_PATH_NAME_MAX-1] = 0;
1015 ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
1018 fprintf(stderr, "ERROR: device scan failed '%s' - %s\n",
1019 fname, strerror(e));
1024 int btrfs_scan_one_dir(char *dirname, int run_ioctl)
1027 struct dirent *dirent;
1028 struct pending_dir *pending;
1034 struct list_head pending_list;
1035 struct btrfs_fs_devices *tmp_devices;
1038 INIT_LIST_HEAD(&pending_list);
1040 pending = malloc(sizeof(*pending));
1043 strcpy(pending->name, dirname);
1046 dirname_len = strlen(pending->name);
1047 fullpath = malloc(PATH_MAX);
1048 dirname = pending->name;
1054 dirp = opendir(dirname);
1056 fprintf(stderr, "Unable to open %s for scanning\n", dirname);
1061 dirent = readdir(dirp);
1064 if (dirent->d_name[0] == '.')
1066 if (dirname_len + strlen(dirent->d_name) + 2 > PATH_MAX) {
1070 snprintf(fullpath, PATH_MAX, "%s/%s", dirname, dirent->d_name);
1071 ret = lstat(fullpath, &st);
1073 fprintf(stderr, "failed to stat %s\n", fullpath);
1076 if (S_ISLNK(st.st_mode))
1078 if (S_ISDIR(st.st_mode)) {
1079 struct pending_dir *next = malloc(sizeof(*next));
1084 strcpy(next->name, fullpath);
1085 list_add_tail(&next->list, &pending_list);
1087 if (!S_ISBLK(st.st_mode)) {
1090 fd = open(fullpath, O_RDONLY);
1092 /* ignore the following errors:
1093 ENXIO (device don't exists)
1094 ENOMEDIUM (No medium found ->
1095 like a cd tray empty)
1097 if(errno != ENXIO && errno != ENOMEDIUM)
1098 fprintf(stderr, "failed to read %s: %s\n",
1099 fullpath, strerror(errno));
1102 ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
1104 BTRFS_SUPER_INFO_OFFSET);
1105 if (ret == 0 && run_ioctl > 0) {
1106 btrfs_register_one_device(fullpath);
1110 if (!list_empty(&pending_list)) {
1112 pending = list_entry(pending_list.next, struct pending_dir,
1115 list_del(&pending->list);
1129 int btrfs_scan_for_fsid(int run_ioctls)
1133 ret = scan_for_btrfs(BTRFS_SCAN_PROC, run_ioctls);
1135 ret = scan_for_btrfs(BTRFS_SCAN_DEV, run_ioctls);
1139 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
1142 struct btrfs_super_block *disk_super;
1146 buf = malloc(BTRFS_SUPER_INFO_SIZE);
1151 ret = pread(fd, buf, BTRFS_SUPER_INFO_SIZE, super_offset);
1152 if (ret != BTRFS_SUPER_INFO_SIZE)
1156 disk_super = (struct btrfs_super_block *)buf;
1157 if (btrfs_super_magic(disk_super) != BTRFS_MAGIC)
1160 if (!memcmp(disk_super->fsid, root->fs_info->super_copy->fsid,
1169 static char *size_strs[] = { "", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"};
1170 void pretty_size_snprintf(u64 size, char *str, size_t str_bytes)
1182 u64 last_size = size;
1184 while(size >= 1024){
1190 if (num_divs >= ARRAY_SIZE(size_strs)) {
1194 fraction = (float)last_size / 1024;
1196 snprintf(str, str_bytes, "%.2f%s", fraction, size_strs[num_divs]);
1200 * __strncpy__null - strncpy with null termination
1201 * @dest: the target array
1202 * @src: the source string
1203 * @n: maximum bytes to copy (size of *dest)
1205 * Like strncpy, but ensures destination is null-terminated.
1207 * Copies the string pointed to by src, including the terminating null
1208 * byte ('\0'), to the buffer pointed to by dest, up to a maximum
1209 * of n bytes. Then ensure that dest is null-terminated.
1211 char *__strncpy__null(char *dest, const char *src, size_t n)
1213 strncpy(dest, src, n);
1220 * Checks to make sure that the label matches our requirements.
1222 0 if everything is safe and usable
1223 -1 if the label is too long
1225 static int check_label(const char *input)
1227 int len = strlen(input);
1229 if (len > BTRFS_LABEL_SIZE - 1) {
1230 fprintf(stderr, "ERROR: Label %s is too long (max %d)\n",
1231 input, BTRFS_LABEL_SIZE - 1);
1238 static int set_label_unmounted(const char *dev, const char *label)
1240 struct btrfs_trans_handle *trans;
1241 struct btrfs_root *root;
1244 ret = check_mounted(dev);
1246 fprintf(stderr, "FATAL: error checking %s mount status\n", dev);
1250 fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n",
1255 /* Open the super_block at the default location
1256 * and as read-write.
1258 root = open_ctree(dev, 0, 1);
1259 if (!root) /* errors are printed by open_ctree() */
1262 trans = btrfs_start_transaction(root, 1);
1263 snprintf(root->fs_info->super_copy->label, BTRFS_LABEL_SIZE, "%s",
1265 btrfs_commit_transaction(trans, root);
1267 /* Now we close it since we are done. */
1272 static int set_label_mounted(const char *mount_path, const char *label)
1276 fd = open(mount_path, O_RDONLY | O_NOATIME);
1278 fprintf(stderr, "ERROR: unable access to '%s'\n", mount_path);
1282 if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) {
1283 fprintf(stderr, "ERROR: unable to set label %s\n",
1293 static int get_label_unmounted(const char *dev)
1295 struct btrfs_root *root;
1298 ret = check_mounted(dev);
1300 fprintf(stderr, "FATAL: error checking %s mount status\n", dev);
1304 fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n",
1309 /* Open the super_block at the default location
1312 root = open_ctree(dev, 0, 0);
1316 fprintf(stdout, "%s\n", root->fs_info->super_copy->label);
1318 /* Now we close it since we are done. */
1324 * If a partition is mounted, try to get the filesystem label via its
1325 * mounted path rather than device. Return the corresponding error
1326 * the user specified the device path.
1328 int get_label_mounted(const char *mount_path, char *labelp)
1330 char label[BTRFS_LABEL_SIZE];
1333 fd = open(mount_path, O_RDONLY | O_NOATIME);
1335 fprintf(stderr, "ERROR: unable access to '%s'\n", mount_path);
1339 memset(label, '\0', sizeof(label));
1340 if (ioctl(fd, BTRFS_IOC_GET_FSLABEL, label) < 0) {
1341 fprintf(stderr, "ERROR: unable get label %s\n", strerror(errno));
1346 strncpy(labelp, label, sizeof(label));
1351 int get_label(const char *btrfs_dev)
1354 char label[BTRFS_LABEL_SIZE];
1356 if (is_existing_blk_or_reg_file(btrfs_dev))
1357 ret = get_label_unmounted(btrfs_dev);
1359 ret = get_label_mounted(btrfs_dev, label);
1361 fprintf(stdout, "%s\n", label);
1366 int set_label(const char *btrfs_dev, const char *label)
1368 if (check_label(label))
1371 return is_existing_blk_or_reg_file(btrfs_dev) ?
1372 set_label_unmounted(btrfs_dev, label) :
1373 set_label_mounted(btrfs_dev, label);
1376 int btrfs_scan_block_devices(int run_ioctl)
1382 struct btrfs_fs_devices *tmp_devices;
1384 FILE *proc_partitions;
1392 proc_partitions = fopen("/proc/partitions","r");
1393 if (!proc_partitions) {
1394 fprintf(stderr, "Unable to open '/proc/partitions' for scanning\n");
1397 /* skip the header */
1398 for (i = 0; i < 2; i++)
1399 if (!fgets(buf, 1023, proc_partitions)) {
1401 "Unable to read '/proc/partitions' for scanning\n");
1402 fclose(proc_partitions);
1406 strcpy(fullpath,"/dev/");
1407 while(fgets(buf, 1023, proc_partitions)) {
1408 i = sscanf(buf," %*d %*d %*d %99s", fullpath+5);
1411 * multipath and MD devices may register as a btrfs filesystem
1412 * both through the original block device and through
1413 * the special (/dev/mapper or /dev/mdX) entry.
1414 * This scans the special entries last
1416 special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0;
1418 special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0;
1420 if (scans == 0 && special)
1422 if (scans > 0 && !special)
1425 ret = lstat(fullpath, &st);
1427 fprintf(stderr, "failed to stat %s\n", fullpath);
1430 if (!S_ISBLK(st.st_mode)) {
1434 fd = open(fullpath, O_RDONLY);
1436 if (errno != ENOMEDIUM)
1437 fprintf(stderr, "failed to open %s: %s\n",
1438 fullpath, strerror(errno));
1441 ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
1443 BTRFS_SUPER_INFO_OFFSET);
1444 if (ret == 0 && run_ioctl > 0) {
1445 btrfs_register_one_device(fullpath);
1450 fclose(proc_partitions);
1459 u64 parse_size(char *s)
1465 for (i = 0; s && s[i] && isdigit(s[i]); i++) ;
1467 fprintf(stderr, "ERROR: size value is empty\n");
1489 fprintf(stderr, "ERROR: Unknown size descriptor "
1494 if (s[i] && s[i+1]) {
1495 fprintf(stderr, "ERROR: Illegal suffix contains "
1496 "character '%c' in wrong position\n",
1500 return strtoull(s, NULL, 10) * mult;
1503 int open_file_or_dir(const char *fname, DIR **dirstream)
1509 ret = stat(fname, &st);
1513 if (S_ISDIR(st.st_mode)) {
1514 *dirstream = opendir(fname);
1517 fd = dirfd(*dirstream);
1519 fd = open(fname, O_RDWR);
1524 closedir(*dirstream);
1529 void close_file_or_dir(int fd, DIR *dirstream)
1532 closedir(dirstream);
1537 static int get_device_info(int fd, u64 devid,
1538 struct btrfs_ioctl_dev_info_args *di_args)
1542 di_args->devid = devid;
1543 memset(&di_args->uuid, '\0', sizeof(di_args->uuid));
1545 ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args);
1546 return ret ? -errno : 0;
1550 * For a given path, fill in the ioctl fs_ and info_ args.
1551 * If the path is a btrfs mountpoint, fill info for all devices.
1552 * If the path is a btrfs device, fill in only that device.
1554 * The path provided must be either on a mounted btrfs fs,
1555 * or be a mounted btrfs device.
1557 * Returns 0 on success, or a negative errno.
1559 int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args,
1560 struct btrfs_ioctl_dev_info_args **di_ret)
1566 struct btrfs_fs_devices *fs_devices_mnt = NULL;
1567 struct btrfs_ioctl_dev_info_args *di_args;
1568 char mp[BTRFS_PATH_NAME_MAX + 1];
1569 DIR *dirstream = NULL;
1571 memset(fi_args, 0, sizeof(*fi_args));
1573 if (is_block_device(path)) {
1574 /* Ensure it's mounted, then set path to the mountpoint */
1575 fd = open(path, O_RDONLY);
1578 fprintf(stderr, "Couldn't open %s: %s\n",
1579 path, strerror(errno));
1582 ret = check_mounted_where(fd, path, mp, sizeof(mp),
1591 /* Only fill in this one device */
1592 fi_args->num_devices = 1;
1593 fi_args->max_id = fs_devices_mnt->latest_devid;
1594 i = fs_devices_mnt->latest_devid;
1595 memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE);
1599 /* at this point path must not be for a block device */
1600 fd = open_file_or_dir(path, &dirstream);
1606 /* fill in fi_args if not just a single device */
1607 if (fi_args->num_devices != 1) {
1608 ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
1615 if (!fi_args->num_devices)
1618 di_args = *di_ret = malloc(fi_args->num_devices * sizeof(*di_args));
1624 for (; i <= fi_args->max_id; ++i) {
1625 BUG_ON(ndevs >= fi_args->num_devices);
1626 ret = get_device_info(fd, i, &di_args[ndevs]);
1637 close_file_or_dir(fd, dirstream);
1641 #define isoctal(c) (((c) & ~7) == '0')
1643 static inline void translate(char *f, char *t)
1645 while (*f != '\0') {
1647 isoctal(f[1]) && isoctal(f[2]) && isoctal(f[3])) {
1648 *t++ = 64*(f[1] & 7) + 8*(f[2] & 7) + (f[3] & 7);
1658 * Checks if the swap device.
1659 * Returns 1 if swap device, < 0 on error or 0 if not swap device.
1661 static int is_swap_device(const char *file)
1672 if (stat(file, &st_buf) < 0)
1674 if (S_ISBLK(st_buf.st_mode))
1675 dev = st_buf.st_rdev;
1676 else if (S_ISREG(st_buf.st_mode)) {
1677 dev = st_buf.st_dev;
1678 ino = st_buf.st_ino;
1682 if ((f = fopen("/proc/swaps", "r")) == NULL)
1685 /* skip the first line */
1686 if (fgets(tmp, sizeof(tmp), f) == NULL)
1689 while (fgets(tmp, sizeof(tmp), f) != NULL) {
1690 if ((cp = strchr(tmp, ' ')) != NULL)
1692 if ((cp = strchr(tmp, '\t')) != NULL)
1694 translate(tmp, buf);
1695 if (stat(buf, &st_buf) != 0)
1697 if (S_ISBLK(st_buf.st_mode)) {
1698 if (dev == st_buf.st_rdev) {
1702 } else if (S_ISREG(st_buf.st_mode)) {
1703 if (dev == st_buf.st_dev && ino == st_buf.st_ino) {
1717 * Check for existing filesystem or partition table on device.
1719 * 1 for existing fs or partition
1720 * 0 for nothing found
1721 * -1 for internal error
1728 blkid_probe pr = NULL;
1732 if (!device || !*device)
1735 ret = -1; /* will reset on success of all setup calls */
1737 pr = blkid_new_probe_from_filename(device);
1741 size = blkid_probe_get_size(pr);
1745 /* nothing to overwrite on a 0-length device */
1751 ret = blkid_probe_enable_partitions(pr, 1);
1755 ret = blkid_do_fullprobe(pr);
1760 * Blkid returns 1 for nothing found and 0 when it finds a signature,
1761 * but we want the exact opposite, so reverse the return value here.
1763 * In addition print some useful diagnostics about what actually is
1771 if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
1773 "%s appears to contain an existing "
1774 "filesystem (%s).\n", device, type);
1775 } else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
1777 "%s appears to contain a partition "
1778 "table (%s).\n", device, type);
1781 "%s appears to contain something weird "
1782 "according to blkid\n", device);
1788 blkid_free_probe(pr);
1791 "probe of %s failed, cannot detect "
1792 "existing filesystem.\n", device);
1796 /* Check if disk is suitable for btrfs
1798 * 1: something is wrong, estr provides the error
1801 int test_dev_for_mkfs(char *file, int force_overwrite, char *estr)
1807 ret = is_swap_device(file);
1809 snprintf(estr, sz, "error checking %s status: %s\n", file,
1814 snprintf(estr, sz, "%s is a swap device\n", file);
1817 if (!force_overwrite) {
1818 if (check_overwrite(file)) {
1819 snprintf(estr, sz, "Use the -f option to force overwrite.\n");
1823 ret = check_mounted(file);
1825 snprintf(estr, sz, "error checking %s mount status\n",
1830 snprintf(estr, sz, "%s is mounted\n", file);
1833 /* check if the device is busy */
1834 fd = open(file, O_RDWR|O_EXCL);
1836 snprintf(estr, sz, "unable to open %s: %s\n", file,
1840 if (fstat(fd, &st)) {
1841 snprintf(estr, sz, "unable to stat %s: %s\n", file,
1845 if (!S_ISBLK(st.st_mode)) {
1846 fprintf(stderr, "'%s' is not a block device\n", file);
1854 * scans devs for the btrfs
1856 int scan_for_btrfs(int where, int update_kernel)
1861 case BTRFS_SCAN_PROC:
1862 ret = btrfs_scan_block_devices(update_kernel);
1864 case BTRFS_SCAN_DEV:
1865 ret = btrfs_scan_one_dir("/dev", update_kernel);