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btrfs-progs/utils.c

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
* Copyright (C) 2008 Morey Roof. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#define _XOPEN_SOURCE 700
#define __USE_XOPEN2K8
#define __XOPEN2K8 /* due to an error in dirent.h, to get dirfd() */
#define _GNU_SOURCE /* O_NOATIME */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef __CHECKER__
#include <sys/ioctl.h>
#include <sys/mount.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <uuid/uuid.h>
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
#include <mntent.h>
#include <ctype.h>
#include <linux/loop.h>
#include <linux/major.h>
#include <linux/kdev_t.h>
#include <limits.h>
#include <blkid/blkid.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "crc32c.h"
#include "utils.h"
#include "volumes.h"
#include "ioctl.h"
#ifdef __CHECKER__
#define BLKGETSIZE64 0
static inline int ioctl(int fd, int define, u64 *size) { return 0; }
#endif
#ifndef BLKDISCARD
#define BLKDISCARD _IO(0x12,119)
#endif
static int
discard_blocks(int fd, u64 start, u64 len)
{
u64 range[2] = { start, len };
if (ioctl(fd, BLKDISCARD, &range) < 0)
return errno;
return 0;
}
static u64 reference_root_table[] = {
[1] = BTRFS_ROOT_TREE_OBJECTID,
[2] = BTRFS_EXTENT_TREE_OBJECTID,
[3] = BTRFS_CHUNK_TREE_OBJECTID,
[4] = BTRFS_DEV_TREE_OBJECTID,
[5] = BTRFS_FS_TREE_OBJECTID,
[6] = BTRFS_CSUM_TREE_OBJECTID,
};
int make_btrfs(int fd, const char *device, const char *label,
u64 blocks[7], u64 num_bytes, u32 nodesize,
u32 leafsize, u32 sectorsize, u32 stripesize)
{
struct btrfs_super_block super;
struct extent_buffer *buf;
struct btrfs_root_item root_item;
struct btrfs_disk_key disk_key;
struct btrfs_extent_item *extent_item;
struct btrfs_inode_item *inode_item;
struct btrfs_chunk *chunk;
struct btrfs_dev_item *dev_item;
struct btrfs_dev_extent *dev_extent;
u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
u8 *ptr;
int i;
int ret;
u32 itemoff;
u32 nritems = 0;
u64 first_free;
u64 ref_root;
u32 array_size;
u32 item_size;
first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
first_free &= ~((u64)sectorsize - 1);
memset(&super, 0, sizeof(super));
num_bytes = (num_bytes / sectorsize) * sectorsize;
uuid_generate(super.fsid);
uuid_generate(super.dev_item.uuid);
uuid_generate(chunk_tree_uuid);
btrfs_set_super_bytenr(&super, blocks[0]);
btrfs_set_super_num_devices(&super, 1);
super.magic = cpu_to_le64(BTRFS_MAGIC);
btrfs_set_super_generation(&super, 1);
btrfs_set_super_root(&super, blocks[1]);
btrfs_set_super_chunk_root(&super, blocks[3]);
btrfs_set_super_total_bytes(&super, num_bytes);
btrfs_set_super_bytes_used(&super, 6 * leafsize);
btrfs_set_super_sectorsize(&super, sectorsize);
btrfs_set_super_leafsize(&super, leafsize);
btrfs_set_super_nodesize(&super, nodesize);
btrfs_set_super_stripesize(&super, stripesize);
btrfs_set_super_csum_type(&super, BTRFS_CSUM_TYPE_CRC32);
btrfs_set_super_chunk_root_generation(&super, 1);
btrfs_set_super_cache_generation(&super, -1);
if (label)
strncpy(super.label, label, BTRFS_LABEL_SIZE - 1);
buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));
/* create the tree of root objects */
memset(buf->data, 0, leafsize);
buf->len = leafsize;
btrfs_set_header_bytenr(buf, blocks[1]);
btrfs_set_header_nritems(buf, 4);
btrfs_set_header_generation(buf, 1);
btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
write_extent_buffer(buf, super.fsid, (unsigned long)
btrfs_header_fsid(buf), BTRFS_FSID_SIZE);
write_extent_buffer(buf, chunk_tree_uuid, (unsigned long)
btrfs_header_chunk_tree_uuid(buf),
BTRFS_UUID_SIZE);
/* create the items for the root tree */
memset(&root_item, 0, sizeof(root_item));
inode_item = &root_item.inode;
btrfs_set_stack_inode_generation(inode_item, 1);
btrfs_set_stack_inode_size(inode_item, 3);
btrfs_set_stack_inode_nlink(inode_item, 1);
btrfs_set_stack_inode_nbytes(inode_item, leafsize);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, leafsize);
btrfs_set_root_generation(&root_item, 1);
memset(&disk_key, 0, sizeof(disk_key));
btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, 0);
nritems = 0;
itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, blocks[2]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,
nritems), sizeof(root_item));
nritems++;
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, blocks[4]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, blocks[5]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, blocks[6]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_CSUM_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[1]);
BUG_ON(ret != leafsize);
/* create the items for the extent tree */
memset(buf->data+sizeof(struct btrfs_header), 0,
leafsize-sizeof(struct btrfs_header));
nritems = 0;
itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize);
for (i = 1; i < 7; i++) {
BUG_ON(blocks[i] < first_free);
BUG_ON(blocks[i] < blocks[i - 1]);
/* create extent item */
itemoff -= sizeof(struct btrfs_extent_item) +
sizeof(struct btrfs_tree_block_info);
btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
btrfs_set_disk_key_offset(&disk_key, leafsize);
btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(struct btrfs_extent_item) +
sizeof(struct btrfs_tree_block_info));
extent_item = btrfs_item_ptr(buf, nritems,
struct btrfs_extent_item);
btrfs_set_extent_refs(buf, extent_item, 1);
btrfs_set_extent_generation(buf, extent_item, 1);
btrfs_set_extent_flags(buf, extent_item,
BTRFS_EXTENT_FLAG_TREE_BLOCK);
nritems++;
/* create extent ref */
ref_root = reference_root_table[i];
btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
btrfs_set_disk_key_offset(&disk_key, ref_root);
btrfs_set_disk_key_type(&disk_key, BTRFS_TREE_BLOCK_REF_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), 0);
nritems++;
}
btrfs_set_header_bytenr(buf, blocks[2]);
btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_header_nritems(buf, nritems);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[2]);
BUG_ON(ret != leafsize);
/* create the chunk tree */
memset(buf->data+sizeof(struct btrfs_header), 0,
leafsize-sizeof(struct btrfs_header));
nritems = 0;
item_size = sizeof(*dev_item);
itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - item_size;
/* first device 1 (there is no device 0) */
btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
btrfs_set_disk_key_offset(&disk_key, 1);
btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);
dev_item = btrfs_item_ptr(buf, nritems, struct btrfs_dev_item);
btrfs_set_device_id(buf, dev_item, 1);
btrfs_set_device_generation(buf, dev_item, 0);
btrfs_set_device_total_bytes(buf, dev_item, num_bytes);
btrfs_set_device_bytes_used(buf, dev_item,
BTRFS_MKFS_SYSTEM_GROUP_SIZE);
btrfs_set_device_io_align(buf, dev_item, sectorsize);
btrfs_set_device_io_width(buf, dev_item, sectorsize);
btrfs_set_device_sector_size(buf, dev_item, sectorsize);
btrfs_set_device_type(buf, dev_item, 0);
write_extent_buffer(buf, super.dev_item.uuid,
(unsigned long)btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
write_extent_buffer(buf, super.fsid,
(unsigned long)btrfs_device_fsid(dev_item),
BTRFS_UUID_SIZE);
read_extent_buffer(buf, &super.dev_item, (unsigned long)dev_item,
sizeof(*dev_item));
nritems++;
item_size = btrfs_chunk_item_size(1);
itemoff = itemoff - item_size;
/* then we have chunk 0 */
btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_disk_key_offset(&disk_key, 0);
btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);
chunk = btrfs_item_ptr(buf, nritems, struct btrfs_chunk);
btrfs_set_chunk_length(buf, chunk, BTRFS_MKFS_SYSTEM_GROUP_SIZE);
btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);
btrfs_set_chunk_type(buf, chunk, BTRFS_BLOCK_GROUP_SYSTEM);
btrfs_set_chunk_io_align(buf, chunk, sectorsize);
btrfs_set_chunk_io_width(buf, chunk, sectorsize);
btrfs_set_chunk_sector_size(buf, chunk, sectorsize);
btrfs_set_chunk_num_stripes(buf, chunk, 1);
btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
btrfs_set_stripe_offset_nr(buf, chunk, 0, 0);
nritems++;
write_extent_buffer(buf, super.dev_item.uuid,
(unsigned long)btrfs_stripe_dev_uuid(&chunk->stripe),
BTRFS_UUID_SIZE);
/* copy the key for the chunk to the system array */
ptr = super.sys_chunk_array;
array_size = sizeof(disk_key);
memcpy(ptr, &disk_key, sizeof(disk_key));
ptr += sizeof(disk_key);
/* copy the chunk to the system array */
read_extent_buffer(buf, ptr, (unsigned long)chunk, item_size);
array_size += item_size;
ptr += item_size;
btrfs_set_super_sys_array_size(&super, array_size);
btrfs_set_header_bytenr(buf, blocks[3]);
btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);
btrfs_set_header_nritems(buf, nritems);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[3]);
/* create the device tree */
memset(buf->data+sizeof(struct btrfs_header), 0,
leafsize-sizeof(struct btrfs_header));
nritems = 0;
itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
sizeof(struct btrfs_dev_extent);
btrfs_set_disk_key_objectid(&disk_key, 1);
btrfs_set_disk_key_offset(&disk_key, 0);
btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(struct btrfs_dev_extent));
dev_extent = btrfs_item_ptr(buf, nritems, struct btrfs_dev_extent);
btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
BTRFS_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_chunk_offset(buf, dev_extent, 0);
write_extent_buffer(buf, chunk_tree_uuid,
(unsigned long)btrfs_dev_extent_chunk_tree_uuid(dev_extent),
BTRFS_UUID_SIZE);
btrfs_set_dev_extent_length(buf, dev_extent,
BTRFS_MKFS_SYSTEM_GROUP_SIZE);
nritems++;
btrfs_set_header_bytenr(buf, blocks[4]);
btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);
btrfs_set_header_nritems(buf, nritems);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[4]);
/* create the FS root */
memset(buf->data+sizeof(struct btrfs_header), 0,
leafsize-sizeof(struct btrfs_header));
btrfs_set_header_bytenr(buf, blocks[5]);
btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
btrfs_set_header_nritems(buf, 0);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[5]);
BUG_ON(ret != leafsize);
/* finally create the csum root */
memset(buf->data+sizeof(struct btrfs_header), 0,
leafsize-sizeof(struct btrfs_header));
btrfs_set_header_bytenr(buf, blocks[6]);
btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);
btrfs_set_header_nritems(buf, 0);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[6]);
BUG_ON(ret != leafsize);
/* and write out the super block */
BUG_ON(sizeof(super) > sectorsize);
memset(buf->data, 0, sectorsize);
memcpy(buf->data, &super, sizeof(super));
buf->len = sectorsize;
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
BUG_ON(ret != sectorsize);
free(buf);
return 0;
}
u64 btrfs_device_size(int fd, struct stat *st)
{
u64 size;
if (S_ISREG(st->st_mode)) {
return st->st_size;
}
if (!S_ISBLK(st->st_mode)) {
return 0;
}
if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
return size;
}
return 0;
}
static int zero_blocks(int fd, off_t start, size_t len)
{
char *buf = malloc(len);
int ret = 0;
ssize_t written;
if (!buf)
return -ENOMEM;
memset(buf, 0, len);
written = pwrite(fd, buf, len, start);
if (written != len)
ret = -EIO;
free(buf);
return ret;
}
static int zero_dev_start(int fd)
{
off_t start = 0;
size_t len = 2 * 1024 * 1024;
#ifdef __sparc__
/* don't overwrite the disk labels on sparc */
start = 1024;
len -= 1024;
#endif
return zero_blocks(fd, start, len);
}
static int zero_dev_end(int fd, u64 dev_size)
{
size_t len = 2 * 1024 * 1024;
off_t start = dev_size - len;
return zero_blocks(fd, start, len);
}
int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
struct btrfs_root *root, int fd, char *path,
u64 block_count, u32 io_width, u32 io_align,
u32 sectorsize)
{
struct btrfs_super_block *disk_super;
struct btrfs_super_block *super = root->fs_info->super_copy;
struct btrfs_device *device;
struct btrfs_dev_item *dev_item;
char *buf;
u64 total_bytes;
u64 num_devs;
int ret;
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device)
return -ENOMEM;
buf = kmalloc(sectorsize, GFP_NOFS);
if (!buf) {
kfree(device);
return -ENOMEM;
}
BUG_ON(sizeof(*disk_super) > sectorsize);
memset(buf, 0, sectorsize);
disk_super = (struct btrfs_super_block *)buf;
dev_item = &disk_super->dev_item;
uuid_generate(device->uuid);
device->devid = 0;
device->type = 0;
device->io_width = io_width;
device->io_align = io_align;
device->sector_size = sectorsize;
device->fd = fd;
device->writeable = 1;
device->total_bytes = block_count;
device->bytes_used = 0;
device->total_ios = 0;
device->dev_root = root->fs_info->dev_root;
ret = btrfs_add_device(trans, root, device);
BUG_ON(ret);
total_bytes = btrfs_super_total_bytes(super) + block_count;
btrfs_set_super_total_bytes(super, total_bytes);
num_devs = btrfs_super_num_devices(super) + 1;
btrfs_set_super_num_devices(super, num_devs);
memcpy(disk_super, super, sizeof(*disk_super));
printf("adding device %s id %llu\n", path,
(unsigned long long)device->devid);
btrfs_set_super_bytenr(disk_super, BTRFS_SUPER_INFO_OFFSET);
btrfs_set_stack_device_id(dev_item, device->devid);
btrfs_set_stack_device_type(dev_item, device->type);
btrfs_set_stack_device_io_align(dev_item, device->io_align);
btrfs_set_stack_device_io_width(dev_item, device->io_width);
btrfs_set_stack_device_sector_size(dev_item, device->sector_size);
btrfs_set_stack_device_total_bytes(dev_item, device->total_bytes);
btrfs_set_stack_device_bytes_used(dev_item, device->bytes_used);
memcpy(&dev_item->uuid, device->uuid, BTRFS_UUID_SIZE);
ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
BUG_ON(ret != sectorsize);
kfree(buf);
list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
device->fs_devices = root->fs_info->fs_devices;
return 0;
}
int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret,
u64 max_block_count, int *mixed, int nodiscard)
{
u64 block_count;
u64 bytenr;
struct stat st;
int i, ret;
ret = fstat(fd, &st);
if (ret < 0) {
fprintf(stderr, "unable to stat %s\n", file);
exit(1);
}
block_count = btrfs_device_size(fd, &st);
if (block_count == 0) {
fprintf(stderr, "unable to find %s size\n", file);
exit(1);
}
if (max_block_count)
block_count = min(block_count, max_block_count);
zero_end = 1;
if (block_count < 1024 * 1024 * 1024 && !(*mixed)) {
printf("SMALL VOLUME: forcing mixed metadata/data groups\n");
*mixed = 1;
}
if (!nodiscard) {
/*
* We intentionally ignore errors from the discard ioctl. It is
* not necessary for the mkfs functionality but just an optimization.
*/
discard_blocks(fd, 0, block_count);
}
ret = zero_dev_start(fd);
if (ret) {
fprintf(stderr, "failed to zero device start %d\n", ret);
exit(1);
}
for (i = 0 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr >= block_count)
break;
zero_blocks(fd, bytenr, BTRFS_SUPER_INFO_SIZE);
}
if (zero_end) {
ret = zero_dev_end(fd, block_count);
if (ret) {
fprintf(stderr, "failed to zero device end %d\n", ret);
exit(1);
}
}
*block_count_ret = block_count;
return 0;
}
int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid)
{
int ret;
struct btrfs_inode_item inode_item;
time_t now = time(NULL);
memset(&inode_item, 0, sizeof(inode_item));
btrfs_set_stack_inode_generation(&inode_item, trans->transid);
btrfs_set_stack_inode_size(&inode_item, 0);
btrfs_set_stack_inode_nlink(&inode_item, 1);
btrfs_set_stack_inode_nbytes(&inode_item, root->leafsize);
btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);
btrfs_set_stack_timespec_sec(&inode_item.atime, now);
btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);
btrfs_set_stack_timespec_sec(&inode_item.ctime, now);
btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);
btrfs_set_stack_timespec_sec(&inode_item.mtime, now);
btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);
btrfs_set_stack_timespec_sec(&inode_item.otime, 0);
btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);
if (root->fs_info->tree_root == root)
btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);
ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
if (ret)
goto error;
ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);
if (ret)
goto error;
btrfs_set_root_dirid(&root->root_item, objectid);
ret = 0;
error:
return ret;
}
/*
* checks if a path is a block device node
* Returns negative errno on failure, otherwise
* returns 1 for blockdev, 0 for not-blockdev
*/
int is_block_device(const char *path) {
struct stat statbuf;
if (stat(path, &statbuf) < 0)
return -errno;
return S_ISBLK(statbuf.st_mode);
}
/*
* Find the mount point for a mounted device.
* On success, returns 0 with mountpoint in *mp.
* On failure, returns -errno (not mounted yields -EINVAL)
* Is noisy on failures, expects to be given a mounted device.
*/
int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {
int ret;
int fd = -1;
ret = is_block_device(dev);
if (ret <= 0) {
if (!ret) {
fprintf(stderr, "%s is not a block device\n", dev);
ret = -EINVAL;
} else {
fprintf(stderr, "Could not check %s: %s\n",
dev, strerror(-ret));
}
goto out;
}
fd = open(dev, O_RDONLY);
if (fd < 0) {
ret = -errno;
fprintf(stderr, "Could not open %s: %s\n", dev, strerror(errno));
goto out;
}
ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
if (!ret) {
fprintf(stderr, "%s is not a mounted btrfs device\n", dev);
ret = -EINVAL;
} else { /* mounted, all good */
ret = 0;
}
out:
if (fd != -1)
close(fd);
if (ret)
fprintf(stderr, "Could not get mountpoint for %s\n", dev);
return ret;
}
/*
* Given a pathname, return a filehandle to:
* the original pathname or,
* if the pathname is a mounted btrfs device, to its mountpoint.
*
* On error, return -1, errno should be set.
*/
int open_path_or_dev_mnt(const char *path)
{
char mp[BTRFS_PATH_NAME_MAX + 1];
int fdmnt;
if (is_block_device(path)) {
int ret;
ret = get_btrfs_mount(path, mp, sizeof(mp));
if (ret < 0) {
/* not a mounted btrfs dev */
errno = EINVAL;
return -1;
}
fdmnt = open_file_or_dir(mp);
} else {
fdmnt = open_file_or_dir(path);
}
return fdmnt;
}
/* checks if a device is a loop device */
int is_loop_device (const char* device) {
struct stat statbuf;
if(stat(device, &statbuf) < 0)
return -errno;
return (S_ISBLK(statbuf.st_mode) &&
MAJOR(statbuf.st_rdev) == LOOP_MAJOR);
}
/* Takes a loop device path (e.g. /dev/loop0) and returns
* the associated file (e.g. /images/my_btrfs.img) */
int resolve_loop_device(const char* loop_dev, char* loop_file, int max_len)
{
int ret;
FILE *f;
char fmt[20];
char p[PATH_MAX];
char real_loop_dev[PATH_MAX];
if (!realpath(loop_dev, real_loop_dev))
return -errno;
snprintf(p, PATH_MAX, "/sys/block/%s/loop/backing_file", strrchr(real_loop_dev, '/'));
if (!(f = fopen(p, "r")))
return -errno;
snprintf(fmt, 20, "%%%i[^\n]", max_len-1);
ret = fscanf(f, fmt, loop_file);
fclose(f);
if (ret == EOF)
return -errno;
return 0;
}
/* Checks whether a and b are identical or device
* files associated with the same block device
*/
int is_same_blk_file(const char* a, const char* b)
{
struct stat st_buf_a, st_buf_b;
char real_a[PATH_MAX];
char real_b[PATH_MAX];
if(!realpath(a, real_a) ||
!realpath(b, real_b))
{
return -errno;
}
/* Identical path? */
if(strcmp(real_a, real_b) == 0)
return 1;
if(stat(a, &st_buf_a) < 0 ||
stat(b, &st_buf_b) < 0)
{
if (errno == ENOENT)
return 0;
return -errno;
}
/* Same blockdevice? */
if(S_ISBLK(st_buf_a.st_mode) &&
S_ISBLK(st_buf_b.st_mode) &&
st_buf_a.st_rdev == st_buf_b.st_rdev)
{
return 1;
}
/* Hardlink? */
if (st_buf_a.st_dev == st_buf_b.st_dev &&
st_buf_a.st_ino == st_buf_b.st_ino)
{
return 1;
}
return 0;
}
/* checks if a and b are identical or device
* files associated with the same block device or
* if one file is a loop device that uses the other
* file.
*/
int is_same_loop_file(const char* a, const char* b)
{
char res_a[PATH_MAX];
char res_b[PATH_MAX];
const char* final_a;
const char* final_b;
int ret;
/* Resolve a if it is a loop device */
if((ret = is_loop_device(a)) < 0) {
if (ret == -ENOENT)
return 0;
return ret;
} else if (ret) {
if ((ret = resolve_loop_device(a, res_a, sizeof(res_a))) < 0)
return ret;
final_a = res_a;
} else {
final_a = a;
}
/* Resolve b if it is a loop device */
if ((ret = is_loop_device(b)) < 0) {
if (ret == -ENOENT)
return 0;
return ret;
} else if (ret) {
if((ret = resolve_loop_device(b, res_b, sizeof(res_b))) < 0)
return ret;
final_b = res_b;
} else {
final_b = b;
}
return is_same_blk_file(final_a, final_b);
}
/* Checks if a file exists and is a block or regular file*/
int is_existing_blk_or_reg_file(const char* filename)
{
struct stat st_buf;
if(stat(filename, &st_buf) < 0) {
if(errno == ENOENT)
return 0;
else
return -errno;
}
return (S_ISBLK(st_buf.st_mode) || S_ISREG(st_buf.st_mode));
}
/* Checks if a file is used (directly or indirectly via a loop device)
* by a device in fs_devices
*/
int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, const char* file)
{
int ret;
struct list_head *head;
struct list_head *cur;
struct btrfs_device *device;
head = &fs_devices->devices;
list_for_each(cur, head) {
device = list_entry(cur, struct btrfs_device, dev_list);
if((ret = is_same_loop_file(device->name, file)))
return ret;
}
return 0;
}
/*
* returns 1 if the device was mounted, < 0 on error or 0 if everything
* is safe to continue.
*/
int check_mounted(const char* file)
{
int fd;
int ret;
fd = open(file, O_RDONLY);
if (fd < 0) {
fprintf (stderr, "check_mounted(): Could not open %s\n", file);
return -errno;
}
ret = check_mounted_where(fd, file, NULL, 0, NULL);
close(fd);
return ret;
}
int check_mounted_where(int fd, const char *file, char *where, int size,
struct btrfs_fs_devices **fs_dev_ret)
{
int ret;
u64 total_devs = 1;
int is_btrfs;
struct btrfs_fs_devices *fs_devices_mnt = NULL;
FILE *f;
struct mntent *mnt;
/* scan the initial device */
ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
&total_devs, BTRFS_SUPER_INFO_OFFSET);
is_btrfs = (ret >= 0);
/* scan other devices */
if (is_btrfs && total_devs > 1) {
if((ret = btrfs_scan_for_fsid(fs_devices_mnt, total_devs, 1)))
return ret;
}
/* iterate over the list of currently mountes filesystems */
if ((f = setmntent ("/proc/mounts", "r")) == NULL)
return -errno;
while ((mnt = getmntent (f)) != NULL) {
if(is_btrfs) {
if(strcmp(mnt->mnt_type, "btrfs") != 0)
continue;
ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname);
} else {
/* ignore entries in the mount table that are not
associated with a file*/
if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0)
goto out_mntloop_err;
else if(!ret)
continue;
ret = is_same_loop_file(file, mnt->mnt_fsname);
}
if(ret < 0)
goto out_mntloop_err;
else if(ret)
break;
}
/* Did we find an entry in mnt table? */
if (mnt && size && where) {
strncpy(where, mnt->mnt_dir, size);
where[size-1] = 0;
}
if (fs_dev_ret)
*fs_dev_ret = fs_devices_mnt;
ret = (mnt != NULL);
out_mntloop_err:
endmntent (f);
return ret;
}
struct pending_dir {
struct list_head list;
char name[PATH_MAX];
};
void btrfs_register_one_device(char *fname)
{
struct btrfs_ioctl_vol_args args;
int fd;
int ret;
int e;
fd = open("/dev/btrfs-control", O_RDONLY);
if (fd < 0) {
fprintf(stderr, "failed to open /dev/btrfs-control "
"skipping device registration: %s\n",
strerror(errno));
return;
}
strncpy(args.name, fname, BTRFS_PATH_NAME_MAX);
args.name[BTRFS_PATH_NAME_MAX-1] = 0;
ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
e = errno;
if(ret<0){
fprintf(stderr, "ERROR: device scan failed '%s' - %s\n",
fname, strerror(e));
}
close(fd);
}
int btrfs_scan_one_dir(char *dirname, int run_ioctl)
{
DIR *dirp = NULL;
struct dirent *dirent;
struct pending_dir *pending;
struct stat st;
int ret;
int fd;
int dirname_len;
char *fullpath;
struct list_head pending_list;
struct btrfs_fs_devices *tmp_devices;
u64 num_devices;
INIT_LIST_HEAD(&pending_list);
pending = malloc(sizeof(*pending));
if (!pending)
return -ENOMEM;
strcpy(pending->name, dirname);
again:
dirname_len = strlen(pending->name);
fullpath = malloc(PATH_MAX);
dirname = pending->name;
if (!fullpath) {
ret = -ENOMEM;
goto fail;
}
dirp = opendir(dirname);
if (!dirp) {
fprintf(stderr, "Unable to open %s for scanning\n", dirname);
free(fullpath);
return -ENOENT;
}
while(1) {
dirent = readdir(dirp);
if (!dirent)
break;
if (dirent->d_name[0] == '.')
continue;
if (dirname_len + strlen(dirent->d_name) + 2 > PATH_MAX) {
ret = -EFAULT;
goto fail;
}
snprintf(fullpath, PATH_MAX, "%s/%s", dirname, dirent->d_name);
ret = lstat(fullpath, &st);
if (ret < 0) {
fprintf(stderr, "failed to stat %s\n", fullpath);
continue;
}
if (S_ISLNK(st.st_mode))
continue;
if (S_ISDIR(st.st_mode)) {
struct pending_dir *next = malloc(sizeof(*next));
if (!next) {
ret = -ENOMEM;
goto fail;
}
strcpy(next->name, fullpath);
list_add_tail(&next->list, &pending_list);
}
if (!S_ISBLK(st.st_mode)) {
continue;
}
fd = open(fullpath, O_RDONLY);
if (fd < 0) {
/* ignore the following errors:
ENXIO (device don't exists)
ENOMEDIUM (No medium found ->
like a cd tray empty)
*/
if(errno != ENXIO && errno != ENOMEDIUM)
fprintf(stderr, "failed to read %s: %s\n",
fullpath, strerror(errno));
continue;
}
ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
&num_devices,
BTRFS_SUPER_INFO_OFFSET);
if (ret == 0 && run_ioctl > 0) {
btrfs_register_one_device(fullpath);
}
close(fd);
}
if (!list_empty(&pending_list)) {
free(pending);
pending = list_entry(pending_list.next, struct pending_dir,
list);
free(fullpath);
list_del(&pending->list);
closedir(dirp);
dirp = NULL;
goto again;
}
ret = 0;
fail:
free(pending);
free(fullpath);
if (dirp)
closedir(dirp);
return ret;
}
int btrfs_scan_for_fsid(struct btrfs_fs_devices *fs_devices, u64 total_devs,
int run_ioctls)
{
int ret;
ret = btrfs_scan_block_devices(run_ioctls);
if (ret)
ret = btrfs_scan_one_dir("/dev", run_ioctls);
return ret;
}
int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
int super_offset)
{
struct btrfs_super_block *disk_super;
char *buf;
int ret = 0;
buf = malloc(BTRFS_SUPER_INFO_SIZE);
if (!buf) {
ret = -ENOMEM;
goto out;
}
ret = pread(fd, buf, BTRFS_SUPER_INFO_SIZE, super_offset);
if (ret != BTRFS_SUPER_INFO_SIZE)
goto brelse;
ret = 0;
disk_super = (struct btrfs_super_block *)buf;
if (disk_super->magic != cpu_to_le64(BTRFS_MAGIC))
goto brelse;
if (!memcmp(disk_super->fsid, root->fs_info->super_copy->fsid,
BTRFS_FSID_SIZE))
ret = 1;
brelse:
free(buf);
out:
return ret;
}
static char *size_strs[] = { "", "KB", "MB", "GB", "TB",
"PB", "EB", "ZB", "YB"};
char *pretty_sizes(u64 size)
{
int num_divs = 0;
int pretty_len = 16;
float fraction;
char *pretty;
if( size < 1024 ){
fraction = size;
num_divs = 0;
} else {
u64 last_size = size;
num_divs = 0;
while(size >= 1024){
last_size = size;
size /= 1024;
num_divs ++;
}
if (num_divs >= ARRAY_SIZE(size_strs))
return NULL;
fraction = (float)last_size / 1024;
}
pretty = malloc(pretty_len);
snprintf(pretty, pretty_len, "%.2f%s", fraction, size_strs[num_divs]);
return pretty;
}
/*
* __strncpy__null - strncpy with null termination
* @dest: the target array
* @src: the source string
* @n: maximum bytes to copy (size of *dest)
*
* Like strncpy, but ensures destination is null-terminated.
*
* Copies the string pointed to by src, including the terminating null
* byte ('\0'), to the buffer pointed to by dest, up to a maximum
* of n bytes. Then ensure that dest is null-terminated.
*/
char *__strncpy__null(char *dest, const char *src, size_t n)
{
strncpy(dest, src, n);
if (n > 0)
dest[n - 1] = '\0';
return dest;
}
/*
* Checks to make sure that the label matches our requirements.
* Returns:
0 if everything is safe and usable
-1 if the label is too long
*/
static int check_label(const char *input)
{
int len = strlen(input);
if (len > BTRFS_LABEL_SIZE - 1) {
fprintf(stderr, "ERROR: Label %s is too long (max %d)\n",
input, BTRFS_LABEL_SIZE - 1);
return -1;
}
return 0;
}
static int set_label_unmounted(const char *dev, const char *label)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
ret = check_mounted(dev);
if (ret < 0) {
fprintf(stderr, "FATAL: error checking %s mount status\n", dev);
return -1;
}
if (ret > 0) {
fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n",
dev);
return -1;
}
/* Open the super_block at the default location
* and as read-write.
*/
root = open_ctree(dev, 0, 1);
if (!root) /* errors are printed by open_ctree() */
return -1;
trans = btrfs_start_transaction(root, 1);
snprintf(root->fs_info->super_copy->label, BTRFS_LABEL_SIZE, "%s",
label);
btrfs_commit_transaction(trans, root);
/* Now we close it since we are done. */
close_ctree(root);
return 0;
}
static int set_label_mounted(const char *mount_path, const char *label)
{
int fd;
fd = open(mount_path, O_RDONLY | O_NOATIME);
if (fd < 0) {
fprintf(stderr, "ERROR: unable access to '%s'\n", mount_path);
return -1;
}
if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) {
fprintf(stderr, "ERROR: unable to set label %s\n",
strerror(errno));
close(fd);
return -1;
}
close(fd);
return 0;
}
static int get_label_unmounted(const char *dev)
{
struct btrfs_root *root;
int ret;
ret = check_mounted(dev);
if (ret < 0) {
fprintf(stderr, "FATAL: error checking %s mount status\n", dev);
return -1;
}
if (ret > 0) {
fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n",
dev);
return -1;
}
/* Open the super_block at the default location
* and as read-only.
*/
root = open_ctree(dev, 0, 0);
if(!root)
return -1;
fprintf(stdout, "%s\n", root->fs_info->super_copy->label);
/* Now we close it since we are done. */
close_ctree(root);
return 0;
}
/*
* If a partition is mounted, try to get the filesystem label via its
* mounted path rather than device. Return the corresponding error
* the user specified the device path.
*/
static int get_label_mounted(const char *mount_path)
{
char label[BTRFS_LABEL_SIZE];
int fd;
fd = open(mount_path, O_RDONLY | O_NOATIME);
if (fd < 0) {
fprintf(stderr, "ERROR: unable access to '%s'\n", mount_path);
return -1;
}
memset(label, '\0', sizeof(label));
if (ioctl(fd, BTRFS_IOC_GET_FSLABEL, label) < 0) {
fprintf(stderr, "ERROR: unable get label %s\n", strerror(errno));
close(fd);
return -1;
}
fprintf(stdout, "%s\n", label);
close(fd);
return 0;
}
int get_label(const char *btrfs_dev)
{
return is_existing_blk_or_reg_file(btrfs_dev) ?
get_label_unmounted(btrfs_dev) :
get_label_mounted(btrfs_dev);
}
int set_label(const char *btrfs_dev, const char *label)
{
if (check_label(label))
return -1;
return is_existing_blk_or_reg_file(btrfs_dev) ?
set_label_unmounted(btrfs_dev, label) :
set_label_mounted(btrfs_dev, label);
}
int btrfs_scan_block_devices(int run_ioctl)
{
struct stat st;
int ret;
int fd;
struct btrfs_fs_devices *tmp_devices;
u64 num_devices;
FILE *proc_partitions;
int i;
char buf[1024];
char fullpath[110];
int scans = 0;
int special;
scan_again:
proc_partitions = fopen("/proc/partitions","r");
if (!proc_partitions) {
fprintf(stderr, "Unable to open '/proc/partitions' for scanning\n");
return -ENOENT;
}
/* skip the header */
for (i = 0; i < 2; i++)
if (!fgets(buf, 1023, proc_partitions)) {
fprintf(stderr,
"Unable to read '/proc/partitions' for scanning\n");
fclose(proc_partitions);
return -ENOENT;
}
strcpy(fullpath,"/dev/");
while(fgets(buf, 1023, proc_partitions)) {
i = sscanf(buf," %*d %*d %*d %99s", fullpath+5);
/*
* multipath and MD devices may register as a btrfs filesystem
* both through the original block device and through
* the special (/dev/mapper or /dev/mdX) entry.
* This scans the special entries last
*/
special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0;
if (!special)
special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0;
if (scans == 0 && special)
continue;
if (scans > 0 && !special)
continue;
ret = lstat(fullpath, &st);
if (ret < 0) {
fprintf(stderr, "failed to stat %s\n", fullpath);
continue;
}
if (!S_ISBLK(st.st_mode)) {
continue;
}
fd = open(fullpath, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "failed to open %s: %s\n",
fullpath, strerror(errno));
continue;
}
ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
&num_devices,
BTRFS_SUPER_INFO_OFFSET);
if (ret == 0 && run_ioctl > 0) {
btrfs_register_one_device(fullpath);
}
close(fd);
}
fclose(proc_partitions);
if (scans == 0) {
scans++;
goto scan_again;
}
return 0;
}
u64 parse_size(char *s)
{
int i;
char c;
u64 mult = 1;
for (i = 0; s && s[i] && isdigit(s[i]); i++) ;
if (!i) {
fprintf(stderr, "ERROR: size value is empty\n");
exit(50);
}
if (s[i]) {
c = tolower(s[i]);
switch (c) {
case 'e':
mult *= 1024;
case 'p':
mult *= 1024;
case 't':
mult *= 1024;
case 'g':
mult *= 1024;
case 'm':
mult *= 1024;
case 'k':
mult *= 1024;
case 'b':
break;
default:
fprintf(stderr, "ERROR: Unknown size descriptor "
"'%c'\n", c);
exit(1);
}
}
if (s[i] && s[i+1]) {
fprintf(stderr, "ERROR: Illegal suffix contains "
"character '%c' in wrong position\n",
s[i+1]);
exit(51);
}
return strtoull(s, NULL, 10) * mult;
}
int open_file_or_dir(const char *fname)
{
int ret;
struct stat st;
DIR *dirstream;
int fd;
ret = stat(fname, &st);
if (ret < 0) {
return -1;
}
if (S_ISDIR(st.st_mode)) {
dirstream = opendir(fname);
if (!dirstream) {
return -2;
}
fd = dirfd(dirstream);
} else {
fd = open(fname, O_RDWR);
}
if (fd < 0) {
return -3;
}
return fd;
}
int get_device_info(int fd, u64 devid,
struct btrfs_ioctl_dev_info_args *di_args)
{
int ret;
di_args->devid = devid;
memset(&di_args->uuid, '\0', sizeof(di_args->uuid));
ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args);
return ret ? -errno : 0;
}
/*
* For a given path, fill in the ioctl fs_ and info_ args.
* If the path is a btrfs mountpoint, fill info for all devices.
* If the path is a btrfs device, fill in only that device.
*
* The path provided must be either on a mounted btrfs fs,
* or be a mounted btrfs device.
*
* Returns 0 on success, or a negative errno.
*/
int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args,
struct btrfs_ioctl_dev_info_args **di_ret)
{
int fd = -1;
int ret = 0;
int ndevs = 0;
int i = 1;
struct btrfs_fs_devices *fs_devices_mnt = NULL;
struct btrfs_ioctl_dev_info_args *di_args;
char mp[BTRFS_PATH_NAME_MAX + 1];
memset(fi_args, 0, sizeof(*fi_args));
if (is_block_device(path)) {
/* Ensure it's mounted, then set path to the mountpoint */
fd = open(path, O_RDONLY);
if (fd < 0) {
ret = -errno;
fprintf(stderr, "Couldn't open %s: %s\n",
path, strerror(errno));
goto out;
}
ret = check_mounted_where(fd, path, mp, sizeof(mp),
&fs_devices_mnt);
if (!ret) {
ret = -EINVAL;
goto out;
}
if (ret < 0)
goto out;
path = mp;
/* Only fill in this one device */
fi_args->num_devices = 1;
fi_args->max_id = fs_devices_mnt->latest_devid;
i = fs_devices_mnt->latest_devid;
memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE);
close(fd);
}
/* at this point path must not be for a block device */
fd = open_file_or_dir(path);
if (fd < 0) {
ret = -errno;
goto out;
}
/* fill in fi_args if not just a single device */
if (fi_args->num_devices != 1) {
ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
if (ret < 0) {
ret = -errno;
goto out;
}
}
if (!fi_args->num_devices)
goto out;
di_args = *di_ret = malloc(fi_args->num_devices * sizeof(*di_args));
if (!di_args) {
ret = -errno;
goto out;
}
for (; i <= fi_args->max_id; ++i) {
BUG_ON(ndevs >= fi_args->num_devices);
ret = get_device_info(fd, i, &di_args[ndevs]);
if (ret == -ENODEV)
continue;
if (ret)
goto out;
ndevs++;
}
BUG_ON(ndevs == 0);
ret = 0;
out:
if (fd != -1)
close(fd);
return ret;
}
#define isoctal(c) (((c) & ~7) == '0')
static inline void translate(char *f, char *t)
{
while (*f != '\0') {
if (*f == '\\' &&
isoctal(f[1]) && isoctal(f[2]) && isoctal(f[3])) {
*t++ = 64*(f[1] & 7) + 8*(f[2] & 7) + (f[3] & 7);
f += 4;
} else
*t++ = *f++;
}
*t = '\0';
return;
}
/*
* Checks if the swap device.
* Returns 1 if swap device, < 0 on error or 0 if not swap device.
*/
int is_swap_device(const char *file)
{
FILE *f;
struct stat st_buf;
dev_t dev;
ino_t ino = 0;
char tmp[PATH_MAX];
char buf[PATH_MAX];
char *cp;
int ret = 0;
if (stat(file, &st_buf) < 0)
return -errno;
if (S_ISBLK(st_buf.st_mode))
dev = st_buf.st_rdev;
else if (S_ISREG(st_buf.st_mode)) {
dev = st_buf.st_dev;
ino = st_buf.st_ino;
} else
return 0;
if ((f = fopen("/proc/swaps", "r")) == NULL)
return 0;
/* skip the first line */
if (fgets(tmp, sizeof(tmp), f) == NULL)
goto out;
while (fgets(tmp, sizeof(tmp), f) != NULL) {
if ((cp = strchr(tmp, ' ')) != NULL)
*cp = '\0';
if ((cp = strchr(tmp, '\t')) != NULL)
*cp = '\0';
translate(tmp, buf);
if (stat(buf, &st_buf) != 0)
continue;
if (S_ISBLK(st_buf.st_mode)) {
if (dev == st_buf.st_rdev) {
ret = 1;
break;
}
} else if (S_ISREG(st_buf.st_mode)) {
if (dev == st_buf.st_dev && ino == st_buf.st_ino) {
ret = 1;
break;
}
}
}
out:
fclose(f);
return ret;
}
/*
* Check for existing filesystem or partition table on device.
* Returns:
* 1 for existing fs or partition
* 0 for nothing found
* -1 for internal error
*/
static int
check_overwrite(
char *device)
{
const char *type;
blkid_probe pr = NULL;
int ret;
blkid_loff_t size;
if (!device || !*device)
return 0;
ret = -1; /* will reset on success of all setup calls */
pr = blkid_new_probe_from_filename(device);
if (!pr)
goto out;
size = blkid_probe_get_size(pr);
if (size < 0)
goto out;
/* nothing to overwrite on a 0-length device */
if (size == 0) {
ret = 0;
goto out;
}
ret = blkid_probe_enable_partitions(pr, 1);
if (ret < 0)
goto out;
ret = blkid_do_fullprobe(pr);
if (ret < 0)
goto out;
/*
* Blkid returns 1 for nothing found and 0 when it finds a signature,
* but we want the exact opposite, so reverse the return value here.
*
* In addition print some useful diagnostics about what actually is
* on the device.
*/
if (ret) {
ret = 0;
goto out;
}
if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
fprintf(stderr,
"%s appears to contain an existing "
"filesystem (%s).\n", device, type);
} else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
fprintf(stderr,
"%s appears to contain a partition "
"table (%s).\n", device, type);
} else {
fprintf(stderr,
"%s appears to contain something weird "
"according to blkid\n", device);
}
ret = 1;
out:
if (pr)
blkid_free_probe(pr);
if (ret == -1)
fprintf(stderr,
"probe of %s failed, cannot detect "
"existing filesystem.\n", device);
return ret;
}
/* Check if disk is suitable for btrfs
* returns:
* 1: something is wrong, estr provides the error
* 0: all is fine
*/
int test_dev_for_mkfs(char *file, int force_overwrite, char *estr)
{
int ret, fd;
size_t sz = 100;
ret = is_swap_device(file);
if (ret < 0) {
snprintf(estr, sz, "error checking %s status: %s\n", file,
strerror(-ret));
return 1;
}
if (ret == 1) {
snprintf(estr, sz, "%s is a swap device\n", file);
return 1;
}
if (!force_overwrite) {
if (check_overwrite(file)) {
snprintf(estr, sz, "Use the -f option to force overwrite.\n");
return 1;
}
}
ret = check_mounted(file);
if (ret < 0) {
snprintf(estr, sz, "error checking %s mount status\n",
file);
return 1;
}
if (ret == 1) {
snprintf(estr, sz, "%s is mounted\n", file);
return 1;
}
/* check if the device is busy */
fd = open(file, O_RDWR|O_EXCL);
if (fd < 0) {
snprintf(estr, sz, "unable to open %s: %s\n", file,
strerror(errno));
return 1;
}
close(fd);
return 0;
}
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