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btrfs-progs/utils.c

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/*
* Copyright (C) 2007 Oracle. 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 600
#define __USE_XOPEN2K
#include <stdio.h>
#include <stdlib.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 <linux/loop.h>
#include <linux/major.h>
#include <linux/kdev_t.h>
#include <limits.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
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);
strncpy((char *)&super.magic, BTRFS_MAGIC, sizeof(super.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);
if (label)
strcpy(super.label, label);
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 */
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 */
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 */
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 */
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 */
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;
}
static u64 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 = kmalloc(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 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 = device_size(fd, &st);
if (block_count == 0) {
fprintf(stderr, "unable to find %s size\n", file);
exit(1);
}
zero_end = 1;
if (block_count < 256 * 1024 * 1024) {
fprintf(stderr, "device %s is too small "
"(must be at least 256 MB)\n", file);
exit(1);
}
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;
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 | 0555);
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 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 loop_fd;
int ret_ioctl;
struct loop_info loopinfo;
if ((loop_fd = open(loop_dev, O_RDONLY)) < 0)
return -errno;
ret_ioctl = ioctl(loop_fd, LOOP_GET_STATUS, &loopinfo);
close(loop_fd);
if (ret_ioctl == 0)
strncpy(loop_file, loopinfo.lo_name, max_len);
else
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)
{
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) {
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) {
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 ret;
int fd;
u64 total_devs = 1;
int is_btrfs;
struct btrfs_fs_devices* fs_devices_mnt = NULL;
FILE *f;
struct mntent *mnt;
fd = open(file, O_RDONLY);
if (fd < 0) {
fprintf (stderr, "check_mounted(): Could not open %s\n", file);
return -errno;
}
/* scan the initial device */
ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
&total_devs, BTRFS_SUPER_INFO_OFFSET);
is_btrfs = (ret >= 0);
close(fd);
/* 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? */
ret = (mnt != NULL);
out_mntloop_err:
endmntent (f);
return ret;
}
struct pending_dir {
struct list_head list;
char name[256];
};
void btrfs_register_one_device(char *fname)
{
struct btrfs_ioctl_vol_args args;
int fd;
int ret;
fd = open("/dev/btrfs-control", O_RDONLY);
if (fd < 0) {
fprintf(stderr, "failed to open /dev/btrfs-control "
"skipping device registration\n");
return;
}
strcpy(args.name, fname);
ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
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;
int pathlen;
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);
pathlen = 1024;
fullpath = malloc(pathlen);
dirname = pending->name;
if (!fullpath) {
ret = -ENOMEM;
goto fail;
}
dirp = opendir(dirname);
if (!dirp) {
fprintf(stderr, "Unable to open /sys/block for scanning\n");
return -ENOENT;
}
while(1) {
dirent = readdir(dirp);
if (!dirent)
break;
if (dirent->d_name[0] == '.')
continue;
if (dirname_len + strlen(dirent->d_name) + 2 > pathlen) {
ret = -EFAULT;
goto fail;
}
snprintf(fullpath, pathlen, "%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) {
fprintf(stderr, "failed to read %s\n", fullpath);
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);
list_del(&pending->list);
closedir(dirp);
goto again;
}
ret = 0;
fail:
free(pending);
if (dirp)
closedir(dirp);
return ret;
}
int btrfs_scan_for_fsid(struct btrfs_fs_devices *fs_devices, u64 total_devs,
int run_ioctls)
{
return btrfs_scan_one_dir("/dev", run_ioctls);
}
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 (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
sizeof(disk_super->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;
u64 last_size = size;
u64 fract_size = size;
float fraction;
char *pretty;
while(size > 0) {
fract_size = last_size;
last_size = size;
size /= 1024;
num_divs++;
}
if (num_divs == 0)
num_divs = 1;
if (num_divs > ARRAY_SIZE(size_strs))
return NULL;
fraction = (float)fract_size / 1024;
pretty = malloc(16);
sprintf(pretty, "%.2f%s", fraction, size_strs[num_divs-1]);
return pretty;
}
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