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btrfs-progs/utils.c
Qu Wenruo 53c4e289c2 btrfs-progs: mkfs: Warn user for minimal RAID5/6 devices setup 
For RAID5, 2 devices setup is just RAID1 with more overhead.
For RAID6, 3 devices setup is RAID1 with 3 copies, not what most user
want.

So warn user at mkfs time for such case, and add explain in man pages.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-09-21 11:47:31 +02:00

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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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <uuid/uuid.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 <sys/vfs.h>
#include <sys/statfs.h>
#include <linux/magic.h>
#include <getopt.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"
#include "commands.h"
#ifndef BLKDISCARD
#define BLKDISCARD _IO(0x12,119)
#endif
static int btrfs_scan_done = 0;
static char argv0_buf[ARGV0_BUF_SIZE] = "btrfs";
static int rand_seed_initlized = 0;
static unsigned short rand_seed[3];
const char *get_argv0_buf(void)
{
return argv0_buf;
}
void fixup_argv0(char **argv, const char *token)
{
int len = strlen(argv0_buf);
snprintf(argv0_buf + len, sizeof(argv0_buf) - len, " %s", token);
argv[0] = argv0_buf;
}
void set_argv0(char **argv)
{
strncpy(argv0_buf, argv[0], sizeof(argv0_buf));
argv0_buf[sizeof(argv0_buf) - 1] = 0;
}
int check_argc_exact(int nargs, int expected)
{
if (nargs < expected)
fprintf(stderr, "%s: too few arguments\n", argv0_buf);
if (nargs > expected)
fprintf(stderr, "%s: too many arguments\n", argv0_buf);
return nargs != expected;
}
int check_argc_min(int nargs, int expected)
{
if (nargs < expected) {
fprintf(stderr, "%s: too few arguments\n", argv0_buf);
return 1;
}
return 0;
}
int check_argc_max(int nargs, int expected)
{
if (nargs > expected) {
fprintf(stderr, "%s: too many arguments\n", argv0_buf);
return 1;
}
return 0;
}
/*
* Discard the given range in one go
*/
static int discard_range(int fd, u64 start, u64 len)
{
u64 range[2] = { start, len };
if (ioctl(fd, BLKDISCARD, &range) < 0)
return errno;
return 0;
}
/*
* Discard blocks in the given range in 1G chunks, the process is interruptible
*/
static int discard_blocks(int fd, u64 start, u64 len)
{
while (len > 0) {
/* 1G granularity */
u64 chunk_size = min_t(u64, len, 1*1024*1024*1024);
int ret;
ret = discard_range(fd, start, chunk_size);
if (ret)
return ret;
len -= chunk_size;
start += chunk_size;
}
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 test_uuid_unique(char *fs_uuid)
{
int unique = 1;
blkid_dev_iterate iter = NULL;
blkid_dev dev = NULL;
blkid_cache cache = NULL;
if (blkid_get_cache(&cache, NULL) < 0) {
printf("ERROR: lblkid cache get failed\n");
return 1;
}
blkid_probe_all(cache);
iter = blkid_dev_iterate_begin(cache);
blkid_dev_set_search(iter, "UUID", fs_uuid);
while (blkid_dev_next(iter, &dev) == 0) {
dev = blkid_verify(cache, dev);
if (dev) {
unique = 0;
break;
}
}
blkid_dev_iterate_end(iter);
blkid_put_cache(cache);
return unique;
}
/*
* Reserve space from free_tree.
* The algorithm is very simple, find the first cache_extent with enough space
* and allocate from its beginning.
*/
static int reserve_free_space(struct cache_tree *free_tree, u64 len,
u64 *ret_start)
{
struct cache_extent *cache;
int found = 0;
BUG_ON(!ret_start);
cache = first_cache_extent(free_tree);
while (cache) {
if (cache->size > len) {
found = 1;
*ret_start = cache->start;
cache->size -= len;
if (cache->size == 0) {
remove_cache_extent(free_tree, cache);
free(cache);
} else {
cache->start += len;
}
break;
}
cache = next_cache_extent(cache);
}
if (!found)
return -ENOSPC;
return 0;
}
static inline int write_temp_super(int fd, struct btrfs_super_block *sb,
u64 sb_bytenr)
{
u32 crc = ~(u32)0;
int ret;
crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, (char *)&sb->csum[0]);
ret = pwrite(fd, sb, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
if (ret < BTRFS_SUPER_INFO_SIZE)
ret = (ret < 0 ? -errno : -EIO);
else
ret = 0;
return ret;
}
/*
* Setup temporary superblock at cfg->super_bynter
* Needed info are extracted from cfg, and root_bytenr, chunk_bytenr
*
* For now sys chunk array will be empty and dev_item is empty too.
* They will be re-initialized at temp chunk tree setup.
*
* The superblock signature is not valid, denotes a partially created
* filesystem, needs to be finalized.
*/
static int setup_temp_super(int fd, struct btrfs_mkfs_config *cfg,
u64 root_bytenr, u64 chunk_bytenr)
{
unsigned char chunk_uuid[BTRFS_UUID_SIZE];
char super_buf[BTRFS_SUPER_INFO_SIZE];
struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf;
int ret;
/*
* We rely on cfg->chunk_uuid and cfg->fs_uuid to pass uuid
* for other functions.
* Caller must allocate space for them
*/
BUG_ON(!cfg->chunk_uuid || !cfg->fs_uuid);
memset(super_buf, 0, BTRFS_SUPER_INFO_SIZE);
cfg->num_bytes = round_down(cfg->num_bytes, cfg->sectorsize);
if (cfg->fs_uuid && *cfg->fs_uuid) {
if (uuid_parse(cfg->fs_uuid, super->fsid) != 0) {
error("cound not parse UUID: %s", cfg->fs_uuid);
ret = -EINVAL;
goto out;
}
if (!test_uuid_unique(cfg->fs_uuid)) {
error("non-unique UUID: %s", cfg->fs_uuid);
ret = -EINVAL;
goto out;
}
} else {
uuid_generate(super->fsid);
uuid_unparse(super->fsid, cfg->fs_uuid);
}
uuid_generate(chunk_uuid);
uuid_unparse(chunk_uuid, cfg->chunk_uuid);
btrfs_set_super_bytenr(super, cfg->super_bytenr);
btrfs_set_super_num_devices(super, 1);
btrfs_set_super_magic(super, BTRFS_MAGIC_PARTIAL);
btrfs_set_super_generation(super, 1);
btrfs_set_super_root(super, root_bytenr);
btrfs_set_super_chunk_root(super, chunk_bytenr);
btrfs_set_super_total_bytes(super, cfg->num_bytes);
/*
* Temporary filesystem will only have 6 tree roots:
* chunk tree, root tree, extent_tree, device tree, fs tree
* and csum tree.
*/
btrfs_set_super_bytes_used(super, 6 * cfg->nodesize);
btrfs_set_super_sectorsize(super, cfg->sectorsize);
btrfs_set_super_leafsize(super, cfg->nodesize);
btrfs_set_super_nodesize(super, cfg->nodesize);
btrfs_set_super_stripesize(super, cfg->stripesize);
btrfs_set_super_csum_type(super, BTRFS_CSUM_TYPE_CRC32);
btrfs_set_super_chunk_root(super, chunk_bytenr);
btrfs_set_super_cache_generation(super, -1);
btrfs_set_super_incompat_flags(super, cfg->features);
if (cfg->label)
__strncpy_null(super->label, cfg->label, BTRFS_LABEL_SIZE - 1);
/* Sys chunk array will be re-initialized at chunk tree init time */
super->sys_chunk_array_size = 0;
ret = write_temp_super(fd, super, cfg->super_bytenr);
out:
return ret;
}
/*
* Setup an extent buffer for tree block.
*/
static int setup_temp_extent_buffer(struct extent_buffer *buf,
struct btrfs_mkfs_config *cfg,
u64 bytenr, u64 owner)
{
unsigned char fsid[BTRFS_FSID_SIZE];
unsigned char chunk_uuid[BTRFS_UUID_SIZE];
int ret;
/* We rely on cfg->fs_uuid and chunk_uuid to fsid and chunk uuid */
BUG_ON(!cfg->fs_uuid || !cfg->chunk_uuid);
ret = uuid_parse(cfg->fs_uuid, fsid);
if (ret)
return -EINVAL;
ret = uuid_parse(cfg->chunk_uuid, chunk_uuid);
if (ret)
return -EINVAL;
memset(buf->data, 0, cfg->nodesize);
buf->len = cfg->nodesize;
btrfs_set_header_bytenr(buf, bytenr);
btrfs_set_header_generation(buf, 1);
btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
btrfs_set_header_owner(buf, owner);
btrfs_set_header_flags(buf, BTRFS_HEADER_FLAG_WRITTEN);
write_extent_buffer(buf, chunk_uuid, btrfs_header_chunk_tree_uuid(buf),
BTRFS_UUID_SIZE);
write_extent_buffer(buf, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
return 0;
}
static inline int write_temp_extent_buffer(int fd, struct extent_buffer *buf,
u64 bytenr)
{
int ret;
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
/* Temporary extent buffer is always mapped 1:1 on disk */
ret = pwrite(fd, buf->data, buf->len, bytenr);
if (ret < buf->len)
ret = (ret < 0 ? ret : -EIO);
else
ret = 0;
return ret;
}
/*
* Insert a root item for temporary tree root
*
* Only used in make_btrfs_v2().
*/
static void insert_temp_root_item(struct extent_buffer *buf,
struct btrfs_mkfs_config *cfg,
int *slot, u32 *itemoff, u64 objectid,
u64 bytenr)
{
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct btrfs_disk_key disk_key;
btrfs_set_header_nritems(buf, *slot + 1);
(*itemoff) -= sizeof(root_item);
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, cfg->nodesize);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, cfg->nodesize);
btrfs_set_root_generation(&root_item, 1);
btrfs_set_root_bytenr(&root_item, bytenr);
memset(&disk_key, 0, sizeof(disk_key));
btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
btrfs_set_disk_key_objectid(&disk_key, objectid);
btrfs_set_disk_key_offset(&disk_key, 0);
btrfs_set_item_key(buf, &disk_key, *slot);
btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, *slot),
sizeof(root_item));
(*slot)++;
}
static int setup_temp_root_tree(int fd, struct btrfs_mkfs_config *cfg,
u64 root_bytenr, u64 extent_bytenr,
u64 dev_bytenr, u64 fs_bytenr, u64 csum_bytenr)
{
struct extent_buffer *buf = NULL;
u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
int slot = 0;
int ret;
/*
* Provided bytenr must in ascending order, or tree root will have a
* bad key order.
*/
BUG_ON(!(root_bytenr < extent_bytenr && extent_bytenr < dev_bytenr &&
dev_bytenr < fs_bytenr && fs_bytenr < csum_bytenr));
buf = malloc(sizeof(*buf) + cfg->nodesize);
if (!buf)
return -ENOMEM;
ret = setup_temp_extent_buffer(buf, cfg, root_bytenr,
BTRFS_ROOT_TREE_OBJECTID);
if (ret < 0)
goto out;
insert_temp_root_item(buf, cfg, &slot, &itemoff,
BTRFS_EXTENT_TREE_OBJECTID, extent_bytenr);
insert_temp_root_item(buf, cfg, &slot, &itemoff,
BTRFS_DEV_TREE_OBJECTID, dev_bytenr);
insert_temp_root_item(buf, cfg, &slot, &itemoff,
BTRFS_FS_TREE_OBJECTID, fs_bytenr);
insert_temp_root_item(buf, cfg, &slot, &itemoff,
BTRFS_CSUM_TREE_OBJECTID, csum_bytenr);
ret = write_temp_extent_buffer(fd, buf, root_bytenr);
out:
free(buf);
return ret;
}
static int insert_temp_dev_item(int fd, struct extent_buffer *buf,
struct btrfs_mkfs_config *cfg,
int *slot, u32 *itemoff)
{
struct btrfs_disk_key disk_key;
struct btrfs_dev_item *dev_item;
char super_buf[BTRFS_SUPER_INFO_SIZE];
unsigned char dev_uuid[BTRFS_UUID_SIZE];
unsigned char fsid[BTRFS_FSID_SIZE];
struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf;
int ret;
ret = pread(fd, super_buf, BTRFS_SUPER_INFO_SIZE, cfg->super_bytenr);
if (ret < BTRFS_SUPER_INFO_SIZE) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
btrfs_set_header_nritems(buf, *slot + 1);
(*itemoff) -= sizeof(*dev_item);
/* setup device item 1, 0 is for replace case */
btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
btrfs_set_disk_key_offset(&disk_key, 1);
btrfs_set_item_key(buf, &disk_key, *slot);
btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_item));
dev_item = btrfs_item_ptr(buf, *slot, struct btrfs_dev_item);
/* Generate device uuid */
uuid_generate(dev_uuid);
write_extent_buffer(buf, dev_uuid,
(unsigned long)btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
uuid_parse(cfg->fs_uuid, fsid);
write_extent_buffer(buf, fsid,
(unsigned long)btrfs_device_fsid(dev_item),
BTRFS_FSID_SIZE);
btrfs_set_device_id(buf, dev_item, 1);
btrfs_set_device_generation(buf, dev_item, 0);
btrfs_set_device_total_bytes(buf, dev_item, cfg->num_bytes);
/*
* The number must match the initial SYSTEM and META chunk size
*/
btrfs_set_device_bytes_used(buf, dev_item,
BTRFS_MKFS_SYSTEM_GROUP_SIZE +
BTRFS_CONVERT_META_GROUP_SIZE);
btrfs_set_device_io_align(buf, dev_item, cfg->sectorsize);
btrfs_set_device_io_width(buf, dev_item, cfg->sectorsize);
btrfs_set_device_sector_size(buf, dev_item, cfg->sectorsize);
btrfs_set_device_type(buf, dev_item, 0);
/* Super dev_item is not complete, copy the complete one to sb */
read_extent_buffer(buf, &super->dev_item, (unsigned long)dev_item,
sizeof(*dev_item));
ret = write_temp_super(fd, super, cfg->super_bytenr);
(*slot)++;
out:
return ret;
}
static int insert_temp_chunk_item(int fd, struct extent_buffer *buf,
struct btrfs_mkfs_config *cfg,
int *slot, u32 *itemoff, u64 start, u64 len,
u64 type)
{
struct btrfs_chunk *chunk;
struct btrfs_disk_key disk_key;
char super_buf[BTRFS_SUPER_INFO_SIZE];
struct btrfs_super_block *sb = (struct btrfs_super_block *)super_buf;
int ret = 0;
ret = pread(fd, super_buf, BTRFS_SUPER_INFO_SIZE,
cfg->super_bytenr);
if (ret < BTRFS_SUPER_INFO_SIZE) {
ret = (ret < 0 ? ret : -EIO);
return ret;
}
btrfs_set_header_nritems(buf, *slot + 1);
(*itemoff) -= btrfs_chunk_item_size(1);
btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_disk_key_offset(&disk_key, start);
btrfs_set_item_key(buf, &disk_key, *slot);
btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(*slot),
btrfs_chunk_item_size(1));
chunk = btrfs_item_ptr(buf, *slot, struct btrfs_chunk);
btrfs_set_chunk_length(buf, chunk, len);
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, type);
btrfs_set_chunk_io_align(buf, chunk, cfg->sectorsize);
btrfs_set_chunk_io_width(buf, chunk, cfg->sectorsize);
btrfs_set_chunk_sector_size(buf, chunk, cfg->sectorsize);
btrfs_set_chunk_num_stripes(buf, chunk, 1);
/* TODO: Support DUP profile for system chunk */
btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
/* We are doing 1:1 mapping, so start is its dev offset */
btrfs_set_stripe_offset_nr(buf, chunk, 0, start);
write_extent_buffer(buf, &sb->dev_item.uuid,
(unsigned long)btrfs_stripe_dev_uuid_nr(chunk, 0),
BTRFS_UUID_SIZE);
(*slot)++;
/*
* If it's system chunk, also copy it to super block.
*/
if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
char *cur;
cur = (char *)sb->sys_chunk_array + sb->sys_chunk_array_size;
memcpy(cur, &disk_key, sizeof(disk_key));
cur += sizeof(disk_key);
read_extent_buffer(buf, cur, (unsigned long int)chunk,
btrfs_chunk_item_size(1));
sb->sys_chunk_array_size += btrfs_chunk_item_size(1) +
sizeof(disk_key);
ret = write_temp_super(fd, sb, cfg->super_bytenr);
}
return ret;
}
static int setup_temp_chunk_tree(int fd, struct btrfs_mkfs_config *cfg,
u64 sys_chunk_start, u64 meta_chunk_start,
u64 chunk_bytenr)
{
struct extent_buffer *buf = NULL;
u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
int slot = 0;
int ret;
/* Must ensure SYS chunk starts before META chunk */
BUG_ON(meta_chunk_start < sys_chunk_start);
buf = malloc(sizeof(*buf) + cfg->nodesize);
if (!buf)
return -ENOMEM;
ret = setup_temp_extent_buffer(buf, cfg, chunk_bytenr,
BTRFS_CHUNK_TREE_OBJECTID);
if (ret < 0)
goto out;
ret = insert_temp_dev_item(fd, buf, cfg, &slot, &itemoff);
if (ret < 0)
goto out;
ret = insert_temp_chunk_item(fd, buf, cfg, &slot, &itemoff,
sys_chunk_start,
BTRFS_MKFS_SYSTEM_GROUP_SIZE,
BTRFS_BLOCK_GROUP_SYSTEM);
if (ret < 0)
goto out;
ret = insert_temp_chunk_item(fd, buf, cfg, &slot, &itemoff,
meta_chunk_start,
BTRFS_CONVERT_META_GROUP_SIZE,
BTRFS_BLOCK_GROUP_METADATA);
if (ret < 0)
goto out;
ret = write_temp_extent_buffer(fd, buf, chunk_bytenr);
out:
free(buf);
return ret;
}
static void insert_temp_dev_extent(struct extent_buffer *buf,
int *slot, u32 *itemoff, u64 start, u64 len)
{
struct btrfs_dev_extent *dev_extent;
struct btrfs_disk_key disk_key;
btrfs_set_header_nritems(buf, *slot + 1);
(*itemoff) -= sizeof(*dev_extent);
btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
btrfs_set_disk_key_objectid(&disk_key, 1);
btrfs_set_disk_key_offset(&disk_key, start);
btrfs_set_item_key(buf, &disk_key, *slot);
btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_extent));
dev_extent = btrfs_item_ptr(buf, *slot, struct btrfs_dev_extent);
btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_length(buf, dev_extent, len);
btrfs_set_dev_extent_chunk_offset(buf, dev_extent, start);
btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
BTRFS_CHUNK_TREE_OBJECTID);
(*slot)++;
}
static int setup_temp_dev_tree(int fd, struct btrfs_mkfs_config *cfg,
u64 sys_chunk_start, u64 meta_chunk_start,
u64 dev_bytenr)
{
struct extent_buffer *buf = NULL;
u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
int slot = 0;
int ret;
/* Must ensure SYS chunk starts before META chunk */
BUG_ON(meta_chunk_start < sys_chunk_start);
buf = malloc(sizeof(*buf) + cfg->nodesize);
if (!buf)
return -ENOMEM;
ret = setup_temp_extent_buffer(buf, cfg, dev_bytenr,
BTRFS_DEV_TREE_OBJECTID);
if (ret < 0)
goto out;
insert_temp_dev_extent(buf, &slot, &itemoff, sys_chunk_start,
BTRFS_MKFS_SYSTEM_GROUP_SIZE);
insert_temp_dev_extent(buf, &slot, &itemoff, meta_chunk_start,
BTRFS_CONVERT_META_GROUP_SIZE);
ret = write_temp_extent_buffer(fd, buf, dev_bytenr);
out:
free(buf);
return ret;
}
static int setup_temp_fs_tree(int fd, struct btrfs_mkfs_config *cfg,
u64 fs_bytenr)
{
struct extent_buffer *buf = NULL;
int ret;
buf = malloc(sizeof(*buf) + cfg->nodesize);
if (!buf)
return -ENOMEM;
ret = setup_temp_extent_buffer(buf, cfg, fs_bytenr,
BTRFS_FS_TREE_OBJECTID);
if (ret < 0)
goto out;
/*
* Temporary fs tree is completely empty.
*/
ret = write_temp_extent_buffer(fd, buf, fs_bytenr);
out:
free(buf);
return ret;
}
static int setup_temp_csum_tree(int fd, struct btrfs_mkfs_config *cfg,
u64 csum_bytenr)
{
struct extent_buffer *buf = NULL;
int ret;
buf = malloc(sizeof(*buf) + cfg->nodesize);
if (!buf)
return -ENOMEM;
ret = setup_temp_extent_buffer(buf, cfg, csum_bytenr,
BTRFS_CSUM_TREE_OBJECTID);
if (ret < 0)
goto out;
/*
* Temporary csum tree is completely empty.
*/
ret = write_temp_extent_buffer(fd, buf, csum_bytenr);
out:
free(buf);
return ret;
}
/*
* Insert one temporary extent item.
*
* NOTE: if skinny_metadata is not enabled, this function must be called
* after all other trees are initialized.
* Or fs without skinny-metadata will be screwed up.
*/
static int insert_temp_extent_item(int fd, struct extent_buffer *buf,
struct btrfs_mkfs_config *cfg,
int *slot, u32 *itemoff, u64 bytenr,
u64 ref_root)
{
struct extent_buffer *tmp;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
struct btrfs_disk_key disk_key;
struct btrfs_disk_key tree_info_key;
struct btrfs_tree_block_info *info;
int itemsize;
int skinny_metadata = cfg->features &
BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
int ret;
if (skinny_metadata)
itemsize = sizeof(*ei) + sizeof(*iref);
else
itemsize = sizeof(*ei) + sizeof(*iref) +
sizeof(struct btrfs_tree_block_info);
btrfs_set_header_nritems(buf, *slot + 1);
*(itemoff) -= itemsize;
if (skinny_metadata) {
btrfs_set_disk_key_type(&disk_key, BTRFS_METADATA_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, 0);
} else {
btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, cfg->nodesize);
}
btrfs_set_disk_key_objectid(&disk_key, bytenr);
btrfs_set_item_key(buf, &disk_key, *slot);
btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(*slot), itemsize);
ei = btrfs_item_ptr(buf, *slot, struct btrfs_extent_item);
btrfs_set_extent_refs(buf, ei, 1);
btrfs_set_extent_generation(buf, ei, 1);
btrfs_set_extent_flags(buf, ei, BTRFS_EXTENT_FLAG_TREE_BLOCK);
if (skinny_metadata) {
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
} else {
info = (struct btrfs_tree_block_info *)(ei + 1);
iref = (struct btrfs_extent_inline_ref *)(info + 1);
}
btrfs_set_extent_inline_ref_type(buf, iref,
BTRFS_TREE_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(buf, iref, ref_root);
(*slot)++;
if (skinny_metadata)
return 0;
/*
* Lastly, check the tree block key by read the tree block
* Since we do 1:1 mapping for convert case, we can directly
* read the bytenr from disk
*/
tmp = malloc(sizeof(*tmp) + cfg->nodesize);
if (!tmp)
return -ENOMEM;
ret = setup_temp_extent_buffer(tmp, cfg, bytenr, ref_root);
if (ret < 0)
goto out;
ret = pread(fd, tmp->data, cfg->nodesize, bytenr);
if (ret < cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
if (btrfs_header_nritems(tmp) == 0) {
btrfs_set_disk_key_type(&tree_info_key, 0);
btrfs_set_disk_key_objectid(&tree_info_key, 0);
btrfs_set_disk_key_offset(&tree_info_key, 0);
} else {
btrfs_item_key(tmp, &tree_info_key, 0);
}
btrfs_set_tree_block_key(buf, info, &tree_info_key);
out:
free(tmp);
return ret;
}
static void insert_temp_block_group(struct extent_buffer *buf,
struct btrfs_mkfs_config *cfg,
int *slot, u32 *itemoff,
u64 bytenr, u64 len, u64 used, u64 flag)
{
struct btrfs_block_group_item bgi;
struct btrfs_disk_key disk_key;
btrfs_set_header_nritems(buf, *slot + 1);
(*itemoff) -= sizeof(bgi);
btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
btrfs_set_disk_key_objectid(&disk_key, bytenr);
btrfs_set_disk_key_offset(&disk_key, len);
btrfs_set_item_key(buf, &disk_key, *slot);
btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(bgi));
btrfs_set_block_group_flags(&bgi, flag);
btrfs_set_block_group_used(&bgi, used);
btrfs_set_block_group_chunk_objectid(&bgi,
BTRFS_FIRST_CHUNK_TREE_OBJECTID);
write_extent_buffer(buf, &bgi, btrfs_item_ptr_offset(buf, *slot),
sizeof(bgi));
(*slot)++;
}
static int setup_temp_extent_tree(int fd, struct btrfs_mkfs_config *cfg,
u64 chunk_bytenr, u64 root_bytenr,
u64 extent_bytenr, u64 dev_bytenr,
u64 fs_bytenr, u64 csum_bytenr)
{
struct extent_buffer *buf = NULL;
u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
int slot = 0;
int ret;
/*
* We must ensure provided bytenr are in ascending order,
* or extent tree key order will be broken.
*/
BUG_ON(!(chunk_bytenr < root_bytenr && root_bytenr < extent_bytenr &&
extent_bytenr < dev_bytenr && dev_bytenr < fs_bytenr &&
fs_bytenr < csum_bytenr));
buf = malloc(sizeof(*buf) + cfg->nodesize);
if (!buf)
return -ENOMEM;
ret = setup_temp_extent_buffer(buf, cfg, extent_bytenr,
BTRFS_EXTENT_TREE_OBJECTID);
if (ret < 0)
goto out;
ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
chunk_bytenr, BTRFS_CHUNK_TREE_OBJECTID);
if (ret < 0)
goto out;
insert_temp_block_group(buf, cfg, &slot, &itemoff, chunk_bytenr,
BTRFS_MKFS_SYSTEM_GROUP_SIZE, cfg->nodesize,
BTRFS_BLOCK_GROUP_SYSTEM);
ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
root_bytenr, BTRFS_ROOT_TREE_OBJECTID);
if (ret < 0)
goto out;
/* 5 tree block used, root, extent, dev, fs and csum*/
insert_temp_block_group(buf, cfg, &slot, &itemoff, root_bytenr,
BTRFS_CONVERT_META_GROUP_SIZE, cfg->nodesize * 5,
BTRFS_BLOCK_GROUP_METADATA);
ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
extent_bytenr, BTRFS_EXTENT_TREE_OBJECTID);
if (ret < 0)
goto out;
ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
dev_bytenr, BTRFS_DEV_TREE_OBJECTID);
if (ret < 0)
goto out;
ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
fs_bytenr, BTRFS_FS_TREE_OBJECTID);
if (ret < 0)
goto out;
ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
csum_bytenr, BTRFS_CSUM_TREE_OBJECTID);
if (ret < 0)
goto out;
ret = write_temp_extent_buffer(fd, buf, extent_bytenr);
out:
free(buf);
return ret;
}
/*
* Improved version of make_btrfs().
*
* This one will
* 1) Do chunk allocation to avoid used data
* And after this function, extent type matches chunk type
* 2) Better structured code
* No super long hand written codes to initialized all tree blocks
* Split into small blocks and reuse codes.
* TODO: Reuse tree operation facilities by introducing new flags
*/
static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg,
struct btrfs_convert_context *cctx)
{
struct cache_tree *free = &cctx->free;
struct cache_tree *used = &cctx->used;
u64 sys_chunk_start;
u64 meta_chunk_start;
/* chunk tree bytenr, in system chunk */
u64 chunk_bytenr;
/* metadata trees bytenr, in metadata chunk */
u64 root_bytenr;
u64 extent_bytenr;
u64 dev_bytenr;
u64 fs_bytenr;
u64 csum_bytenr;
int ret;
/* Shouldn't happen */
BUG_ON(cache_tree_empty(used));
/*
* reserve space for temporary superblock first
* Here we allocate a little larger space, to keep later
* free space will be STRIPE_LEN aligned
*/
ret = reserve_free_space(free, BTRFS_STRIPE_LEN,
&cfg->super_bytenr);
if (ret < 0)
goto out;
/*
* Then reserve system chunk space
* TODO: Change system group size depending on cctx->total_bytes.
* If using current 4M, it can only handle less than one TB for
* worst case and then run out of sys space.
*/
ret = reserve_free_space(free, BTRFS_MKFS_SYSTEM_GROUP_SIZE,
&sys_chunk_start);
if (ret < 0)
goto out;
ret = reserve_free_space(free, BTRFS_CONVERT_META_GROUP_SIZE,
&meta_chunk_start);
if (ret < 0)
goto out;
/*
* Allocated meta/sys chunks will be mapped 1:1 with device offset.
*
* Inside the allocated metadata chunk, the layout will be:
* | offset | contents |
* -------------------------------------
* | +0 | tree root |
* | +nodesize | extent root |
* | +nodesize * 2 | device root |
* | +nodesize * 3 | fs tree |
* | +nodesize * 4 | csum tree |
* -------------------------------------
* Inside the allocated system chunk, the layout will be:
* | offset | contents |
* -------------------------------------
* | +0 | chunk root |
* -------------------------------------
*/
chunk_bytenr = sys_chunk_start;
root_bytenr = meta_chunk_start;
extent_bytenr = meta_chunk_start + cfg->nodesize;
dev_bytenr = meta_chunk_start + cfg->nodesize * 2;
fs_bytenr = meta_chunk_start + cfg->nodesize * 3;
csum_bytenr = meta_chunk_start + cfg->nodesize * 4;
ret = setup_temp_super(fd, cfg, root_bytenr, chunk_bytenr);
if (ret < 0)
goto out;
ret = setup_temp_root_tree(fd, cfg, root_bytenr, extent_bytenr,
dev_bytenr, fs_bytenr, csum_bytenr);
if (ret < 0)
goto out;
ret = setup_temp_chunk_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
chunk_bytenr);
if (ret < 0)
goto out;
ret = setup_temp_dev_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
dev_bytenr);
if (ret < 0)
goto out;
ret = setup_temp_fs_tree(fd, cfg, fs_bytenr);
if (ret < 0)
goto out;
ret = setup_temp_csum_tree(fd, cfg, csum_bytenr);
if (ret < 0)
goto out;
/*
* Setup extent tree last, since it may need to read tree block key
* for non-skinny metadata case.
*/
ret = setup_temp_extent_tree(fd, cfg, chunk_bytenr, root_bytenr,
extent_bytenr, dev_bytenr, fs_bytenr,
csum_bytenr);
out:
return ret;
}
/*
* @fs_uuid - if NULL, generates a UUID, returns back the new filesystem UUID
*
* The superblock signature is not valid, denotes a partially created
* filesystem, needs to be finalized.
*/
int make_btrfs(int fd, struct btrfs_mkfs_config *cfg,
struct btrfs_convert_context *cctx)
{
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;
int skinny_metadata = !!(cfg->features &
BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
u64 num_bytes;
if (cctx)
return make_convert_btrfs(fd, cfg, cctx);
buf = malloc(sizeof(*buf) + max(cfg->sectorsize, cfg->nodesize));
if (!buf)
return -ENOMEM;
first_free = BTRFS_SUPER_INFO_OFFSET + cfg->sectorsize * 2 - 1;
first_free &= ~((u64)cfg->sectorsize - 1);
memset(&super, 0, sizeof(super));
num_bytes = (cfg->num_bytes / cfg->sectorsize) * cfg->sectorsize;
if (cfg->fs_uuid && *cfg->fs_uuid) {
if (uuid_parse(cfg->fs_uuid, super.fsid) != 0) {
error("cannot not parse UUID: %s", cfg->fs_uuid);
ret = -EINVAL;
goto out;
}
if (!test_uuid_unique(cfg->fs_uuid)) {
error("non-unique UUID: %s", cfg->fs_uuid);
ret = -EBUSY;
goto out;
}
} else {
uuid_generate(super.fsid);
if (cfg->fs_uuid)
uuid_unparse(super.fsid, cfg->fs_uuid);
}
uuid_generate(super.dev_item.uuid);
uuid_generate(chunk_tree_uuid);
btrfs_set_super_bytenr(&super, cfg->blocks[0]);
btrfs_set_super_num_devices(&super, 1);
btrfs_set_super_magic(&super, BTRFS_MAGIC_PARTIAL);
btrfs_set_super_generation(&super, 1);
btrfs_set_super_root(&super, cfg->blocks[1]);
btrfs_set_super_chunk_root(&super, cfg->blocks[3]);
btrfs_set_super_total_bytes(&super, num_bytes);
btrfs_set_super_bytes_used(&super, 6 * cfg->nodesize);
btrfs_set_super_sectorsize(&super, cfg->sectorsize);
btrfs_set_super_leafsize(&super, cfg->nodesize);
btrfs_set_super_nodesize(&super, cfg->nodesize);
btrfs_set_super_stripesize(&super, cfg->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);
btrfs_set_super_incompat_flags(&super, cfg->features);
if (cfg->label)
__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE - 1);
/* create the tree of root objects */
memset(buf->data, 0, cfg->nodesize);
buf->len = cfg->nodesize;
btrfs_set_header_bytenr(buf, cfg->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, btrfs_header_fsid(),
BTRFS_FSID_SIZE);
write_extent_buffer(buf, chunk_tree_uuid,
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, cfg->nodesize);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, cfg->nodesize);
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(cfg->nodesize) - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, cfg->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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->nodesize, cfg->blocks[1]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
/* create the items for the extent tree */
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
nritems = 0;
itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
for (i = 1; i < 7; i++) {
item_size = sizeof(struct btrfs_extent_item);
if (!skinny_metadata)
item_size += sizeof(struct btrfs_tree_block_info);
BUG_ON(cfg->blocks[i] < first_free);
BUG_ON(cfg->blocks[i] < cfg->blocks[i - 1]);
/* create extent item */
itemoff -= item_size;
btrfs_set_disk_key_objectid(&disk_key, cfg->blocks[i]);
if (skinny_metadata) {
btrfs_set_disk_key_type(&disk_key,
BTRFS_METADATA_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, 0);
} else {
btrfs_set_disk_key_type(&disk_key,
BTRFS_EXTENT_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, cfg->nodesize);
}
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems),
itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
item_size);
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, cfg->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(nritems),
itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems), 0);
nritems++;
}
btrfs_set_header_bytenr(buf, cfg->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, cfg->nodesize, cfg->blocks[2]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
/* create the chunk tree */
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
nritems = 0;
item_size = sizeof(*dev_item);
itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) - 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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->sectorsize);
btrfs_set_device_io_width(buf, dev_item, cfg->sectorsize);
btrfs_set_device_sector_size(buf, dev_item, cfg->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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->sectorsize);
btrfs_set_chunk_io_width(buf, chunk, cfg->sectorsize);
btrfs_set_chunk_sector_size(buf, chunk, cfg->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, cfg->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, cfg->nodesize, cfg->blocks[3]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
/* create the device tree */
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
nritems = 0;
itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) -
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(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(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, cfg->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, cfg->nodesize, cfg->blocks[4]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
/* create the FS root */
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
btrfs_set_header_bytenr(buf, cfg->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, cfg->nodesize, cfg->blocks[5]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
/* finally create the csum root */
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
btrfs_set_header_bytenr(buf, cfg->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, cfg->nodesize, cfg->blocks[6]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
/* and write out the super block */
BUG_ON(sizeof(super) > cfg->sectorsize);
memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
memcpy(buf->data, &super, sizeof(super));
buf->len = BTRFS_SUPER_INFO_SIZE;
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, BTRFS_SUPER_INFO_SIZE, cfg->blocks[0]);
if (ret != BTRFS_SUPER_INFO_SIZE) {
ret = (ret < 0 ? -errno : -EIO);
goto out;
}
ret = 0;
out:
free(buf);
return ret;
}
static const struct btrfs_fs_feature {
const char *name;
u64 flag;
const char *desc;
} mkfs_features[] = {
{ "mixed-bg", BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS,
"mixed data and metadata block groups" },
{ "extref", BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF,
"increased hardlink limit per file to 65536" },
{ "raid56", BTRFS_FEATURE_INCOMPAT_RAID56,
"raid56 extended format" },
{ "skinny-metadata", BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA,
"reduced-size metadata extent refs" },
{ "no-holes", BTRFS_FEATURE_INCOMPAT_NO_HOLES,
"no explicit hole extents for files" },
/* Keep this one last */
{ "list-all", BTRFS_FEATURE_LIST_ALL, NULL }
};
static int parse_one_fs_feature(const char *name, u64 *flags)
{
int i;
int found = 0;
for (i = 0; i < ARRAY_SIZE(mkfs_features); i++) {
if (name[0] == '^' &&
!strcmp(mkfs_features[i].name, name + 1)) {
*flags &= ~ mkfs_features[i].flag;
found = 1;
} else if (!strcmp(mkfs_features[i].name, name)) {
*flags |= mkfs_features[i].flag;
found = 1;
}
}
return !found;
}
void btrfs_parse_features_to_string(char *buf, u64 flags)
{
int i;
buf[0] = 0;
for (i = 0; i < ARRAY_SIZE(mkfs_features); i++) {
if (flags & mkfs_features[i].flag) {
if (*buf)
strcat(buf, ", ");
strcat(buf, mkfs_features[i].name);
}
}
}
void btrfs_process_fs_features(u64 flags)
{
int i;
for (i = 0; i < ARRAY_SIZE(mkfs_features); i++) {
if (flags & mkfs_features[i].flag) {
printf("Turning ON incompat feature '%s': %s\n",
mkfs_features[i].name,
mkfs_features[i].desc);
}
}
}
void btrfs_list_all_fs_features(u64 mask_disallowed)
{
int i;
fprintf(stderr, "Filesystem features available:\n");
for (i = 0; i < ARRAY_SIZE(mkfs_features) - 1; i++) {
char *is_default = "";
if (mkfs_features[i].flag & mask_disallowed)
continue;
if (mkfs_features[i].flag & BTRFS_MKFS_DEFAULT_FEATURES)
is_default = ", default";
fprintf(stderr, "%-20s- %s (0x%llx%s)\n",
mkfs_features[i].name,
mkfs_features[i].desc,
mkfs_features[i].flag,
is_default);
}
}
/*
* Return NULL if all features were parsed fine, otherwise return the name of
* the first unparsed.
*/
char* btrfs_parse_fs_features(char *namelist, u64 *flags)
{
char *this_char;
char *save_ptr = NULL; /* Satisfy static checkers */
for (this_char = strtok_r(namelist, ",", &save_ptr);
this_char != NULL;
this_char = strtok_r(NULL, ",", &save_ptr)) {
if (parse_one_fs_feature(this_char, flags))
return this_char;
}
return NULL;
}
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;
}
#define ZERO_DEV_BYTES (2 * 1024 * 1024)
/* don't write outside the device by clamping the region to the device size */
static int zero_dev_clamped(int fd, off_t start, ssize_t len, u64 dev_size)
{
off_t end = max(start, start + len);
#ifdef __sparc__
/* and don't overwrite the disk labels on sparc */
start = max(start, 1024);
end = max(end, 1024);
#endif
start = min_t(u64, start, dev_size);
end = min_t(u64, end, dev_size);
return zero_blocks(fd, start, end - start);
}
int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
struct btrfs_root *root, int fd, char *path,
u64 device_total_bytes, 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 = NULL;
u64 fs_total_bytes;
u64 num_devs;
int ret;
device_total_bytes = (device_total_bytes / sectorsize) * sectorsize;
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device)
goto err_nomem;
buf = kzalloc(sectorsize, GFP_NOFS);
if (!buf)
goto err_nomem;
BUG_ON(sizeof(*disk_super) > 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 = device_total_bytes;
device->bytes_used = 0;
device->total_ios = 0;
device->dev_root = root->fs_info->dev_root;
device->name = strdup(path);
if (!device->name)
goto err_nomem;
INIT_LIST_HEAD(&device->dev_list);
ret = btrfs_add_device(trans, root, device);
BUG_ON(ret);
fs_total_bytes = btrfs_super_total_bytes(super) + device_total_bytes;
btrfs_set_super_total_bytes(super, fs_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));
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;
err_nomem:
kfree(device);
kfree(buf);
return -ENOMEM;
}
static int btrfs_wipe_existing_sb(int fd)
{
const char *off = NULL;
size_t len = 0;
loff_t offset;
char buf[BUFSIZ];
int ret = 0;
blkid_probe pr = NULL;
pr = blkid_new_probe();
if (!pr)
return -1;
if (blkid_probe_set_device(pr, fd, 0, 0)) {
ret = -1;
goto out;
}
ret = blkid_probe_lookup_value(pr, "SBMAGIC_OFFSET", &off, NULL);
if (!ret)
ret = blkid_probe_lookup_value(pr, "SBMAGIC", NULL, &len);
if (ret || len == 0 || off == NULL) {
/*
* If lookup fails, the probe did not find any values, eg. for
* a file image or a loop device. Soft error.
*/
ret = 1;
goto out;
}
offset = strtoll(off, NULL, 10);
if (len > sizeof(buf))
len = sizeof(buf);
memset(buf, 0, len);
ret = pwrite(fd, buf, len, offset);
if (ret < 0) {
error("cannot wipe existing superblock: %s", strerror(errno));
ret = -1;
} else if (ret != len) {
error("cannot wipe existing superblock: wrote %d of %zd", ret, len);
ret = -1;
}
fsync(fd);
out:
blkid_free_probe(pr);
return ret;
}
int btrfs_prepare_device(int fd, const char *file, u64 *block_count_ret,
u64 max_block_count, unsigned opflags)
{
u64 block_count;
struct stat st;
int i, ret;
ret = fstat(fd, &st);
if (ret < 0) {
error("unable to stat %s: %s", file, strerror(errno));
return 1;
}
block_count = btrfs_device_size(fd, &st);
if (block_count == 0) {
error("unable to determine size of %s", file);
return 1;
}
if (max_block_count)
block_count = min(block_count, max_block_count);
if (opflags & PREP_DEVICE_DISCARD) {
/*
* We intentionally ignore errors from the discard ioctl. It
* is not necessary for the mkfs functionality but just an
* optimization.
*/
if (discard_range(fd, 0, 0) == 0) {
if (opflags & PREP_DEVICE_VERBOSE)
printf("Performing full device TRIM (%s) ...\n",
pretty_size(block_count));
discard_blocks(fd, 0, block_count);
}
}
ret = zero_dev_clamped(fd, 0, ZERO_DEV_BYTES, block_count);
for (i = 0 ; !ret && i < BTRFS_SUPER_MIRROR_MAX; i++)
ret = zero_dev_clamped(fd, btrfs_sb_offset(i),
BTRFS_SUPER_INFO_SIZE, block_count);
if (!ret && (opflags & PREP_DEVICE_ZERO_END))
ret = zero_dev_clamped(fd, block_count - ZERO_DEV_BYTES,
ZERO_DEV_BYTES, block_count);
if (ret < 0) {
error("failed to zero device '%s': %s", file, strerror(-ret));
return 1;
}
ret = btrfs_wipe_existing_sb(fd);
if (ret < 0) {
error("cannot wipe superblocks on %s", file);
return 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->nodesize);
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);
}
/*
* check if given path is a mount point
* return 1 if yes. 0 if no. -1 for error
*/
int is_mount_point(const char *path)
{
FILE *f;
struct mntent *mnt;
int ret = 0;
f = setmntent("/proc/self/mounts", "r");
if (f == NULL)
return -1;
while ((mnt = getmntent(f)) != NULL) {
if (strcmp(mnt->mnt_dir, path))
continue;
ret = 1;
break;
}
endmntent(f);
return ret;
}
static int is_reg_file(const char *path)
{
struct stat statbuf;
if (stat(path, &statbuf) < 0)
return -errno;
return S_ISREG(statbuf.st_mode);
}
/*
* This function checks if the given input parameter is
* an uuid or a path
* return <0 : some error in the given input
* return BTRFS_ARG_UNKNOWN: unknown input
* return BTRFS_ARG_UUID: given input is uuid
* return BTRFS_ARG_MNTPOINT: given input is path
* return BTRFS_ARG_REG: given input is regular file
* return BTRFS_ARG_BLKDEV: given input is block device
*/
int check_arg_type(const char *input)
{
uuid_t uuid;
char path[PATH_MAX];
if (!input)
return -EINVAL;
if (realpath(input, path)) {
if (is_block_device(path) == 1)
return BTRFS_ARG_BLKDEV;
if (is_mount_point(path) == 1)
return BTRFS_ARG_MNTPOINT;
if (is_reg_file(path))
return BTRFS_ARG_REG;
return BTRFS_ARG_UNKNOWN;
}
if (strlen(input) == (BTRFS_UUID_UNPARSED_SIZE - 1) &&
!uuid_parse(input, uuid))
return BTRFS_ARG_UUID;
return BTRFS_ARG_UNKNOWN;
}
/*
* 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) {
error("not a block device: %s", dev);
ret = -EINVAL;
} else {
error("cannot check %s: %s", dev, strerror(-ret));
}
goto out;
}
fd = open(dev, O_RDONLY);
if (fd < 0) {
ret = -errno;
error("cannot open %s: %s", dev, strerror(errno));
goto out;
}
ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
if (!ret) {
ret = -EINVAL;
} else { /* mounted, all good */
ret = 0;
}
out:
if (fd != -1)
close(fd);
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, DIR **dirstream, int verbose)
{
char mp[PATH_MAX];
int ret;
if (is_block_device(path)) {
ret = get_btrfs_mount(path, mp, sizeof(mp));
if (ret < 0) {
/* not a mounted btrfs dev */
error_on(verbose, "'%s' is not a mounted btrfs device",
path);
errno = EINVAL;
return -1;
}
ret = open_file_or_dir(mp, dirstream);
error_on(verbose && ret < 0, "can't access '%s': %s",
path, strerror(errno));
} else {
ret = btrfs_open_dir(path, dirstream, 1);
}
return ret;
}
/*
* Do the following checks before calling open_file_or_dir():
* 1: path is in a btrfs filesystem
* 2: path is a directory
*/
int btrfs_open_dir(const char *path, DIR **dirstream, int verbose)
{
struct statfs stfs;
struct stat st;
int ret;
if (statfs(path, &stfs) != 0) {
error_on(verbose, "cannot access '%s': %s", path,
strerror(errno));
return -1;
}
if (stfs.f_type != BTRFS_SUPER_MAGIC) {
error_on(verbose, "not a btrfs filesystem: %s", path);
return -2;
}
if (stat(path, &st) != 0) {
error_on(verbose, "cannot access '%s': %s", path,
strerror(errno));
return -1;
}
if (!S_ISDIR(st.st_mode)) {
error_on(verbose, "not a directory: %s", path);
return -3;
}
ret = open_file_or_dir(path, dirstream);
if (ret < 0) {
error_on(verbose, "cannot access '%s': %s", path,
strerror(errno));
}
return ret;
}
/* checks if a device is a loop device */
static 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) using
* loopdev API
*/
static int resolve_loop_device_with_loopdev(const char* loop_dev, char* loop_file)
{
int fd;
int ret;
struct loop_info64 lo64;
fd = open(loop_dev, O_RDONLY | O_NONBLOCK);
if (fd < 0)
return -errno;
ret = ioctl(fd, LOOP_GET_STATUS64, &lo64);
if (ret < 0) {
ret = -errno;
goto out;
}
memcpy(loop_file, lo64.lo_file_name, sizeof(lo64.lo_file_name));
loop_file[sizeof(lo64.lo_file_name)] = 0;
out:
close(fd);
return ret;
}
/* Takes a loop device path (e.g. /dev/loop0) and returns
* the associated file (e.g. /images/my_btrfs.img) */
static 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"))) {
if (errno == ENOENT)
/*
* It's possibly a partitioned loop device, which is
* resolvable with loopdev API.
*/
return resolve_loop_device_with_loopdev(loop_dev, loop_file);
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
*/
static 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))
strncpy_null(real_a, a);
if (!realpath(b, real_b))
strncpy_null(real_b, b);
/* 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.
*/
static 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 = NULL;
const char* final_b = NULL;
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) {
ret = resolve_loop_device(a, res_a, sizeof(res_a));
if (ret < 0) {
if (errno != EPERM)
return ret;
} else {
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) {
ret = resolve_loop_device(b, res_b, sizeof(res_b));
if (ret < 0) {
if (errno != EPERM)
return ret;
} else {
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*/
static 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
*/
static 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;
}
/*
* Resolve a pathname to a device mapper node to /dev/mapper/<name>
* Returns NULL on invalid input or malloc failure; Other failures
* will be handled by the caller using the input pathame.
*/
char *canonicalize_dm_name(const char *ptname)
{
FILE *f;
size_t sz;
char path[PATH_MAX], name[PATH_MAX], *res = NULL;
if (!ptname || !*ptname)
return NULL;
snprintf(path, sizeof(path), "/sys/block/%s/dm/name", ptname);
if (!(f = fopen(path, "r")))
return NULL;
/* read <name>\n from sysfs */
if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) {
name[sz - 1] = '\0';
snprintf(path, sizeof(path), "/dev/mapper/%s", name);
if (access(path, F_OK) == 0)
res = strdup(path);
}
fclose(f);
return res;
}
/*
* Resolve a pathname to a canonical device node, e.g. /dev/sda1 or
* to a device mapper pathname.
* Returns NULL on invalid input or malloc failure; Other failures
* will be handled by the caller using the input pathame.
*/
char *canonicalize_path(const char *path)
{
char *canonical, *p;
if (!path || !*path)
return NULL;
canonical = realpath(path, NULL);
if (!canonical)
return strdup(path);
p = strrchr(canonical, '/');
if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4))) {
char *dm = canonicalize_dm_name(p + 1);
if (dm) {
free(canonical);
return dm;
}
}
return canonical;
}
/*
* 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) {
error("mount check: cannot open %s: %s", file,
strerror(errno));
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, SBREAD_DEFAULT);
is_btrfs = (ret >= 0);
/* scan other devices */
if (is_btrfs && total_devs > 1) {
ret = btrfs_scan_lblkid();
if (ret)
return ret;
}
/* iterate over the list of currently mounted filesystems */
if ((f = setmntent ("/proc/self/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];
};
int btrfs_register_one_device(const char *fname)
{
struct btrfs_ioctl_vol_args args;
int fd;
int ret;
fd = open("/dev/btrfs-control", O_RDWR);
if (fd < 0) {
warning(
"failed to open /dev/btrfs-control, skipping device registration: %s",
strerror(errno));
return -errno;
}
memset(&args, 0, sizeof(args));
strncpy_null(args.name, fname);
ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
if (ret < 0) {
error("device scan failed on '%s': %s", fname,
strerror(errno));
ret = -errno;
}
close(fd);
return ret;
}
/*
* Register all devices in the fs_uuid list created in the user
* space. Ensure btrfs_scan_lblkid() is called before this func.
*/
int btrfs_register_all_devices(void)
{
int err = 0;
int ret = 0;
struct btrfs_fs_devices *fs_devices;
struct btrfs_device *device;
struct list_head *all_uuids;
all_uuids = btrfs_scanned_uuids();
list_for_each_entry(fs_devices, all_uuids, list) {
list_for_each_entry(device, &fs_devices->devices, dev_list) {
if (*device->name)
err = btrfs_register_one_device(device->name);
if (err)
ret++;
}
}
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;
/*
* Accept devices from the same filesystem, allow partially created
* structures.
*/
if (btrfs_super_magic(disk_super) != BTRFS_MAGIC &&
btrfs_super_magic(disk_super) != BTRFS_MAGIC_PARTIAL)
goto brelse;
if (!memcmp(disk_super->fsid, root->fs_info->super_copy->fsid,
BTRFS_FSID_SIZE))
ret = 1;
brelse:
free(buf);
out:
return ret;
}
/*
* Note: this function uses a static per-thread buffer. Do not call this
* function more than 10 times within one argument list!
*/
const char *pretty_size_mode(u64 size, unsigned mode)
{
static __thread int ps_index = 0;
static __thread char ps_array[10][32];
char *ret;
ret = ps_array[ps_index];
ps_index++;
ps_index %= 10;
(void)pretty_size_snprintf(size, ret, 32, mode);
return ret;
}
static const char* unit_suffix_binary[] =
{ "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"};
static const char* unit_suffix_decimal[] =
{ "B", "kB", "MB", "GB", "TB", "PB", "EB"};
int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode)
{
int num_divs;
float fraction;
u64 base = 0;
int mult = 0;
const char** suffix = NULL;
u64 last_size;
if (str_size == 0)
return 0;
if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) {
snprintf(str, str_size, "%llu", size);
return 0;
}
if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_BINARY) {
base = 1024;
mult = 1024;
suffix = unit_suffix_binary;
} else if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_DECIMAL) {
base = 1000;
mult = 1000;
suffix = unit_suffix_decimal;
}
/* Unknown mode */
if (!base) {
fprintf(stderr, "INTERNAL ERROR: unknown unit base, mode %d\n",
unit_mode);
assert(0);
return -1;
}
num_divs = 0;
last_size = size;
switch (unit_mode & UNITS_MODE_MASK) {
case UNITS_TBYTES: base *= mult; num_divs++;
case UNITS_GBYTES: base *= mult; num_divs++;
case UNITS_MBYTES: base *= mult; num_divs++;
case UNITS_KBYTES: num_divs++;
break;
case UNITS_BYTES:
base = 1;
num_divs = 0;
break;
default:
while (size >= mult) {
last_size = size;
size /= mult;
num_divs++;
}
/*
* If the value is smaller than base, we didn't do any
* division, in that case, base should be 1, not original
* base, or the unit will be wrong
*/
if (num_divs == 0)
base = 1;
}
if (num_divs >= ARRAY_SIZE(unit_suffix_binary)) {
str[0] = '\0';
printf("INTERNAL ERROR: unsupported unit suffix, index %d\n",
num_divs);
assert(0);
return -1;
}
fraction = (float)last_size / base;
return snprintf(str, str_size, "%.2f%s", fraction, suffix[num_divs]);
}
/*
* __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) {
error("label %s is too long (max %d)", 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) {
error("checking mount status of %s failed: %d", dev, ret);
return -1;
}
if (ret > 0) {
error("device %s is mounted, use mount point", dev);
return -1;
}
/* Open the super_block at the default location
* and as read-write.
*/
root = open_ctree(dev, 0, OPEN_CTREE_WRITES);
if (!root) /* errors are printed by open_ctree() */
return -1;
trans = btrfs_start_transaction(root, 1);
__strncpy_null(root->fs_info->super_copy->label, label, BTRFS_LABEL_SIZE - 1);
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 *labelp)
{
int fd;
char label[BTRFS_LABEL_SIZE];
fd = open(mount_path, O_RDONLY | O_NOATIME);
if (fd < 0) {
error("unable to access %s: %s", mount_path, strerror(errno));
return -1;
}
memset(label, 0, sizeof(label));
__strncpy_null(label, labelp, BTRFS_LABEL_SIZE - 1);
if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) {
error("unable to set label of %s: %s", mount_path,
strerror(errno));
close(fd);
return -1;
}
close(fd);
return 0;
}
int get_label_unmounted(const char *dev, char *label)
{
struct btrfs_root *root;
int ret;
ret = check_mounted(dev);
if (ret < 0) {
error("checking mount status of %s failed: %d", dev, ret);
return -1;
}
/* Open the super_block at the default location
* and as read-only.
*/
root = open_ctree(dev, 0, 0);
if(!root)
return -1;
__strncpy_null(label, root->fs_info->super_copy->label,
BTRFS_LABEL_SIZE - 1);
/* 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.
*/
int get_label_mounted(const char *mount_path, char *labelp)
{
char label[BTRFS_LABEL_SIZE];
int fd;
int ret;
fd = open(mount_path, O_RDONLY | O_NOATIME);
if (fd < 0) {
error("unable to access %s: %s", mount_path, strerror(errno));
return -1;
}
memset(label, '\0', sizeof(label));
ret = ioctl(fd, BTRFS_IOC_GET_FSLABEL, label);
if (ret < 0) {
if (errno != ENOTTY)
error("unable to get label of %s: %s", mount_path,
strerror(errno));
ret = -errno;
close(fd);
return ret;
}
__strncpy_null(labelp, label, BTRFS_LABEL_SIZE - 1);
close(fd);
return 0;
}
int get_label(const char *btrfs_dev, char *label)
{
int ret;
ret = is_existing_blk_or_reg_file(btrfs_dev);
if (!ret)
ret = get_label_mounted(btrfs_dev, label);
else if (ret > 0)
ret = get_label_unmounted(btrfs_dev, label);
return ret;
}
int set_label(const char *btrfs_dev, const char *label)
{
int ret;
if (check_label(label))
return -1;
ret = is_existing_blk_or_reg_file(btrfs_dev);
if (!ret)
ret = set_label_mounted(btrfs_dev, label);
else if (ret > 0)
ret = set_label_unmounted(btrfs_dev, label);
return ret;
}
/*
* A not-so-good version fls64. No fascinating optimization since
* no one except parse_size use it
*/
static int fls64(u64 x)
{
int i;
for (i = 0; i <64; i++)
if (x << i & (1ULL << 63))
return 64 - i;
return 64 - i;
}
u64 parse_size(char *s)
{
char c;
char *endptr;
u64 mult = 1;
u64 ret;
if (!s) {
error("size value is empty");
exit(1);
}
if (s[0] == '-') {
error("size value '%s' is less equal than 0", s);
exit(1);
}
ret = strtoull(s, &endptr, 10);
if (endptr == s) {
error("size value '%s' is invalid", s);
exit(1);
}
if (endptr[0] && endptr[1]) {
error("illegal suffix contains character '%c' in wrong position",
endptr[1]);
exit(1);
}
/*
* strtoll returns LLONG_MAX when overflow, if this happens,
* need to call strtoull to get the real size
*/
if (errno == ERANGE && ret == ULLONG_MAX) {
error("size value '%s' is too large for u64", s);
exit(1);
}
if (endptr[0]) {
c = tolower(endptr[0]);
switch (c) {
case 'e':
mult *= 1024;
/* fallthrough */
case 'p':
mult *= 1024;
/* fallthrough */
case 't':
mult *= 1024;
/* fallthrough */
case 'g':
mult *= 1024;
/* fallthrough */
case 'm':
mult *= 1024;
/* fallthrough */
case 'k':
mult *= 1024;
/* fallthrough */
case 'b':
break;
default:
error("unknown size descriptor '%c'", c);
exit(1);
}
}
/* Check whether ret * mult overflow */
if (fls64(ret) + fls64(mult) - 1 > 64) {
error("size value '%s' is too large for u64", s);
exit(1);
}
ret *= mult;
return ret;
}
u64 parse_qgroupid(const char *p)
{
char *s = strchr(p, '/');
const char *ptr_src_end = p + strlen(p);
char *ptr_parse_end = NULL;
u64 level;
u64 id;
int fd;
int ret = 0;
if (p[0] == '/')
goto path;
/* Numeric format like '0/257' is the primary case */
if (!s) {
id = strtoull(p, &ptr_parse_end, 10);
if (ptr_parse_end != ptr_src_end)
goto path;
return id;
}
level = strtoull(p, &ptr_parse_end, 10);
if (ptr_parse_end != s)
goto path;
id = strtoull(s + 1, &ptr_parse_end, 10);
if (ptr_parse_end != ptr_src_end)
goto path;
return (level << BTRFS_QGROUP_LEVEL_SHIFT) | id;
path:
/* Path format like subv at 'my_subvol' is the fallback case */
ret = test_issubvolume(p);
if (ret < 0 || !ret)
goto err;
fd = open(p, O_RDONLY);
if (fd < 0)
goto err;
ret = lookup_ino_rootid(fd, &id);
if (ret)
error("failed to lookup root id: %s", strerror(-ret));
close(fd);
if (ret < 0)
goto err;
return id;
err:
error("invalid qgroupid or subvolume path: %s", p);
exit(-1);
}
int open_file_or_dir3(const char *fname, DIR **dirstream, int open_flags)
{
int ret;
struct stat st;
int fd;
ret = stat(fname, &st);
if (ret < 0) {
return -1;
}
if (S_ISDIR(st.st_mode)) {
*dirstream = opendir(fname);
if (!*dirstream)
return -1;
fd = dirfd(*dirstream);
} else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
fd = open(fname, open_flags);
} else {
/*
* we set this on purpose, in case the caller output
* strerror(errno) as success
*/
errno = EINVAL;
return -1;
}
if (fd < 0) {
fd = -1;
if (*dirstream) {
closedir(*dirstream);
*dirstream = NULL;
}
}
return fd;
}
int open_file_or_dir(const char *fname, DIR **dirstream)
{
return open_file_or_dir3(fname, dirstream, O_RDWR);
}
void close_file_or_dir(int fd, DIR *dirstream)
{
if (dirstream)
closedir(dirstream);
else if (fd >= 0)
close(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 < 0 ? -errno : 0;
}
static u64 find_max_device_id(struct btrfs_ioctl_search_args *search_args,
int nr_items)
{
struct btrfs_dev_item *dev_item;
char *buf = search_args->buf;
buf += (nr_items - 1) * (sizeof(struct btrfs_ioctl_search_header)
+ sizeof(struct btrfs_dev_item));
buf += sizeof(struct btrfs_ioctl_search_header);
dev_item = (struct btrfs_dev_item *)buf;
return btrfs_stack_device_id(dev_item);
}
static int search_chunk_tree_for_fs_info(int fd,
struct btrfs_ioctl_fs_info_args *fi_args)
{
int ret;
int max_items;
u64 start_devid = 1;
struct btrfs_ioctl_search_args search_args;
struct btrfs_ioctl_search_key *search_key = &search_args.key;
fi_args->num_devices = 0;
max_items = BTRFS_SEARCH_ARGS_BUFSIZE
/ (sizeof(struct btrfs_ioctl_search_header)
+ sizeof(struct btrfs_dev_item));
search_key->tree_id = BTRFS_CHUNK_TREE_OBJECTID;
search_key->min_objectid = BTRFS_DEV_ITEMS_OBJECTID;
search_key->max_objectid = BTRFS_DEV_ITEMS_OBJECTID;
search_key->min_type = BTRFS_DEV_ITEM_KEY;
search_key->max_type = BTRFS_DEV_ITEM_KEY;
search_key->min_transid = 0;
search_key->max_transid = (u64)-1;
search_key->nr_items = max_items;
search_key->max_offset = (u64)-1;
again:
search_key->min_offset = start_devid;
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_args);
if (ret < 0)
return -errno;
fi_args->num_devices += (u64)search_key->nr_items;
if (search_key->nr_items == max_items) {
start_devid = find_max_device_id(&search_args,
search_key->nr_items) + 1;
goto again;
}
/* get the lastest max_id to stay consistent with the num_devices */
if (search_key->nr_items == 0)
/*
* last tree_search returns an empty buf, use the devid of
* the last dev_item of the previous tree_search
*/
fi_args->max_id = start_devid - 1;
else
fi_args->max_id = find_max_device_id(&search_args,
search_key->nr_items);
return 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 = 0;
int replacing = 0;
struct btrfs_fs_devices *fs_devices_mnt = NULL;
struct btrfs_ioctl_dev_info_args *di_args;
struct btrfs_ioctl_dev_info_args tmp;
char mp[PATH_MAX];
DIR *dirstream = NULL;
memset(fi_args, 0, sizeof(*fi_args));
if (is_block_device(path) == 1) {
struct btrfs_super_block *disk_super;
char buf[BTRFS_SUPER_INFO_SIZE];
u64 devid;
/* Ensure it's mounted, then set path to the mountpoint */
fd = open(path, O_RDONLY);
if (fd < 0) {
ret = -errno;
error("cannot open %s: %s", 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;
disk_super = (struct btrfs_super_block *)buf;
ret = btrfs_read_dev_super(fd, disk_super,
BTRFS_SUPER_INFO_OFFSET, 0);
if (ret < 0) {
ret = -EIO;
goto out;
}
devid = btrfs_stack_device_id(&disk_super->dev_item);
fi_args->max_id = devid;
i = 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, &dirstream);
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;
}
/*
* The fs_args->num_devices does not include seed devices
*/
ret = search_chunk_tree_for_fs_info(fd, fi_args);
if (ret)
goto out;
/*
* search_chunk_tree_for_fs_info() will lacks the devid 0
* so manual probe for it here.
*/
ret = get_device_info(fd, 0, &tmp);
if (!ret) {
fi_args->num_devices++;
ndevs++;
replacing = 1;
if (i == 0)
i++;
}
}
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;
}
if (replacing)
memcpy(di_args, &tmp, sizeof(tmp));
for (; i <= fi_args->max_id; ++i) {
ret = get_device_info(fd, i, &di_args[ndevs]);
if (ret == -ENODEV)
continue;
if (ret)
goto out;
ndevs++;
}
/*
* only when the only dev we wanted to find is not there then
* let any error be returned
*/
if (fi_args->num_devices != 1) {
BUG_ON(ndevs == 0);
ret = 0;
}
out:
close_file_or_dir(fd, dirstream);
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.
*/
static 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(const 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;
}
static int group_profile_devs_min(u64 flag)
{
switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
case 0: /* single */
case BTRFS_BLOCK_GROUP_DUP:
return 1;
case BTRFS_BLOCK_GROUP_RAID0:
case BTRFS_BLOCK_GROUP_RAID1:
case BTRFS_BLOCK_GROUP_RAID5:
return 2;
case BTRFS_BLOCK_GROUP_RAID6:
return 3;
case BTRFS_BLOCK_GROUP_RAID10:
return 4;
default:
return -1;
}
}
int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
u64 dev_cnt, int mixed, int ssd)
{
u64 allowed = 0;
u64 profile = metadata_profile | data_profile;
switch (dev_cnt) {
default:
case 4:
allowed |= BTRFS_BLOCK_GROUP_RAID10;
case 3:
allowed |= BTRFS_BLOCK_GROUP_RAID6;
case 2:
allowed |= BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID5;
case 1:
allowed |= BTRFS_BLOCK_GROUP_DUP;
}
if (dev_cnt > 1 && profile & BTRFS_BLOCK_GROUP_DUP) {
warning("DUP is not recommended on filesystem with multiple devices");
}
if (metadata_profile & ~allowed) {
fprintf(stderr,
"ERROR: unable to create FS with metadata profile %s "
"(have %llu devices but %d devices are required)\n",
btrfs_group_profile_str(metadata_profile), dev_cnt,
group_profile_devs_min(metadata_profile));
return 1;
}
if (data_profile & ~allowed) {
fprintf(stderr,
"ERROR: unable to create FS with data profile %s "
"(have %llu devices but %d devices are required)\n",
btrfs_group_profile_str(data_profile), dev_cnt,
group_profile_devs_min(data_profile));
return 1;
}
if (dev_cnt == 3 && profile & BTRFS_BLOCK_GROUP_RAID6) {
warning("RAID6 is not recommended on filesystem with 3 devices only");
}
if (dev_cnt == 2 && profile & BTRFS_BLOCK_GROUP_RAID5) {
warning("RAID5 is not recommended on filesystem with 2 devices only");
}
warning_on(!mixed && (data_profile & BTRFS_BLOCK_GROUP_DUP) && ssd,
"DUP may not actually lead to 2 copies on the device, see manual page");
return 0;
}
int group_profile_max_safe_loss(u64 flags)
{
switch (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
case 0: /* single */
case BTRFS_BLOCK_GROUP_DUP:
case BTRFS_BLOCK_GROUP_RAID0:
return 0;
case BTRFS_BLOCK_GROUP_RAID1:
case BTRFS_BLOCK_GROUP_RAID5:
case BTRFS_BLOCK_GROUP_RAID10:
return 1;
case BTRFS_BLOCK_GROUP_RAID6:
return 2;
default:
return -1;
}
}
/*
* Check if a device is suitable for btrfs
* returns:
* 1: something is wrong, an error is printed
* 0: all is fine
*/
int test_dev_for_mkfs(const char *file, int force_overwrite)
{
int ret, fd;
struct stat st;
ret = is_swap_device(file);
if (ret < 0) {
error("checking status of %s: %s", file, strerror(-ret));
return 1;
}
if (ret == 1) {
error("%s is a swap device", file);
return 1;
}
if (!force_overwrite) {
if (check_overwrite(file)) {
error("use the -f option to force overwrite of %s",
file);
return 1;
}
}
ret = check_mounted(file);
if (ret < 0) {
error("cannot check mount status of %s: %s", file,
strerror(-ret));
return 1;
}
if (ret == 1) {
error("%s is mounted", file);
return 1;
}
/* check if the device is busy */
fd = open(file, O_RDWR|O_EXCL);
if (fd < 0) {
error("unable to open %s: %s", file, strerror(errno));
return 1;
}
if (fstat(fd, &st)) {
error("unable to stat %s: %s", file, strerror(errno));
close(fd);
return 1;
}
if (!S_ISBLK(st.st_mode)) {
error("%s is not a block device", file);
close(fd);
return 1;
}
close(fd);
return 0;
}
int btrfs_scan_lblkid(void)
{
int fd = -1;
int ret;
u64 num_devices;
struct btrfs_fs_devices *tmp_devices;
blkid_dev_iterate iter = NULL;
blkid_dev dev = NULL;
blkid_cache cache = NULL;
char path[PATH_MAX];
if (btrfs_scan_done)
return 0;
if (blkid_get_cache(&cache, NULL) < 0) {
error("blkid cache get failed");
return 1;
}
blkid_probe_all(cache);
iter = blkid_dev_iterate_begin(cache);
blkid_dev_set_search(iter, "TYPE", "btrfs");
while (blkid_dev_next(iter, &dev) == 0) {
dev = blkid_verify(cache, dev);
if (!dev)
continue;
/* if we are here its definitely a btrfs disk*/
strncpy_null(path, blkid_dev_devname(dev));
fd = open(path, O_RDONLY);
if (fd < 0) {
error("cannot open %s: %s", path, strerror(errno));
continue;
}
ret = btrfs_scan_one_device(fd, path, &tmp_devices,
&num_devices, BTRFS_SUPER_INFO_OFFSET,
SBREAD_DEFAULT);
if (ret) {
error("cannot scan %s: %s", path, strerror(-ret));
close (fd);
continue;
}
close(fd);
}
blkid_dev_iterate_end(iter);
blkid_put_cache(cache);
btrfs_scan_done = 1;
return 0;
}
int is_vol_small(const char *file)
{
int fd = -1;
int e;
struct stat st;
u64 size;
fd = open(file, O_RDONLY);
if (fd < 0)
return -errno;
if (fstat(fd, &st) < 0) {
e = -errno;
close(fd);
return e;
}
size = btrfs_device_size(fd, &st);
if (size == 0) {
close(fd);
return -1;
}
if (size < BTRFS_MKFS_SMALL_VOLUME_SIZE) {
close(fd);
return 1;
} else {
close(fd);
return 0;
}
}
/*
* This reads a line from the stdin and only returns non-zero if the
* first whitespace delimited token is a case insensitive match with yes
* or y.
*/
int ask_user(const char *question)
{
char buf[30] = {0,};
char *saveptr = NULL;
char *answer;
printf("%s [y/N]: ", question);
return fgets(buf, sizeof(buf) - 1, stdin) &&
(answer = strtok_r(buf, " \t\n\r", &saveptr)) &&
(!strcasecmp(answer, "yes") || !strcasecmp(answer, "y"));
}
/*
* For a given:
* - file or directory return the containing tree root id
* - subvolume return its own tree id
* - BTRFS_EMPTY_SUBVOL_DIR_OBJECTID (directory with ino == 2) the result is
* undefined and function returns -1
*/
int lookup_ino_rootid(int fd, u64 *rootid)
{
struct btrfs_ioctl_ino_lookup_args args;
int ret;
memset(&args, 0, sizeof(args));
args.treeid = 0;
args.objectid = BTRFS_FIRST_FREE_OBJECTID;
ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
if (ret < 0)
return -errno;
*rootid = args.treeid;
return 0;
}
/*
* return 0 if a btrfs mount point is found
* return 1 if a mount point is found but not btrfs
* return <0 if something goes wrong
*/
int find_mount_root(const char *path, char **mount_root)
{
FILE *mnttab;
int fd;
struct mntent *ent;
int len;
int ret;
int not_btrfs = 1;
int longest_matchlen = 0;
char *longest_match = NULL;
fd = open(path, O_RDONLY | O_NOATIME);
if (fd < 0)
return -errno;
close(fd);
mnttab = setmntent("/proc/self/mounts", "r");
if (!mnttab)
return -errno;
while ((ent = getmntent(mnttab))) {
len = strlen(ent->mnt_dir);
if (strncmp(ent->mnt_dir, path, len) == 0) {
/* match found and use the latest match */
if (longest_matchlen <= len) {
free(longest_match);
longest_matchlen = len;
longest_match = strdup(ent->mnt_dir);
not_btrfs = strcmp(ent->mnt_type, "btrfs");
}
}
}
endmntent(mnttab);
if (!longest_match)
return -ENOENT;
if (not_btrfs) {
free(longest_match);
return 1;
}
ret = 0;
*mount_root = realpath(longest_match, NULL);
if (!*mount_root)
ret = -errno;
free(longest_match);
return ret;
}
int test_minimum_size(const char *file, u32 nodesize)
{
int fd;
struct stat statbuf;
fd = open(file, O_RDONLY);
if (fd < 0)
return -errno;
if (stat(file, &statbuf) < 0) {
close(fd);
return -errno;
}
if (btrfs_device_size(fd, &statbuf) < btrfs_min_dev_size(nodesize)) {
close(fd);
return 1;
}
close(fd);
return 0;
}
/*
* Test if path is a directory
* Returns:
* 0 - path exists but it is not a directory
* 1 - path exists and it is a directory
* < 0 - error
*/
int test_isdir(const char *path)
{
struct stat st;
int ret;
ret = stat(path, &st);
if (ret < 0)
return -errno;
return !!S_ISDIR(st.st_mode);
}
void units_set_mode(unsigned *units, unsigned mode)
{
unsigned base = *units & UNITS_MODE_MASK;
*units = base | mode;
}
void units_set_base(unsigned *units, unsigned base)
{
unsigned mode = *units & ~UNITS_MODE_MASK;
*units = base | mode;
}
int find_next_key(struct btrfs_path *path, struct btrfs_key *key)
{
int level;
for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
if (!path->nodes[level])
break;
if (path->slots[level] + 1 >=
btrfs_header_nritems(path->nodes[level]))
continue;
if (level == 0)
btrfs_item_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
else
btrfs_node_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
return 0;
}
return 1;
}
const char* btrfs_group_type_str(u64 flag)
{
u64 mask = BTRFS_BLOCK_GROUP_TYPE_MASK |
BTRFS_SPACE_INFO_GLOBAL_RSV;
switch (flag & mask) {
case BTRFS_BLOCK_GROUP_DATA:
return "Data";
case BTRFS_BLOCK_GROUP_SYSTEM:
return "System";
case BTRFS_BLOCK_GROUP_METADATA:
return "Metadata";
case BTRFS_BLOCK_GROUP_DATA|BTRFS_BLOCK_GROUP_METADATA:
return "Data+Metadata";
case BTRFS_SPACE_INFO_GLOBAL_RSV:
return "GlobalReserve";
default:
return "unknown";
}
}
const char* btrfs_group_profile_str(u64 flag)
{
switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
case 0:
return "single";
case BTRFS_BLOCK_GROUP_RAID0:
return "RAID0";
case BTRFS_BLOCK_GROUP_RAID1:
return "RAID1";
case BTRFS_BLOCK_GROUP_RAID5:
return "RAID5";
case BTRFS_BLOCK_GROUP_RAID6:
return "RAID6";
case BTRFS_BLOCK_GROUP_DUP:
return "DUP";
case BTRFS_BLOCK_GROUP_RAID10:
return "RAID10";
default:
return "unknown";
}
}
u64 disk_size(const char *path)
{
struct statfs sfs;
if (statfs(path, &sfs) < 0)
return 0;
else
return sfs.f_bsize * sfs.f_blocks;
}
u64 get_partition_size(const char *dev)
{
u64 result;
int fd = open(dev, O_RDONLY);
if (fd < 0)
return 0;
if (ioctl(fd, BLKGETSIZE64, &result) < 0) {
close(fd);
return 0;
}
close(fd);
return result;
}
int btrfs_tree_search2_ioctl_supported(int fd)
{
struct btrfs_ioctl_search_args_v2 *args2;
struct btrfs_ioctl_search_key *sk;
int args2_size = 1024;
char args2_buf[args2_size];
int ret;
static int v2_supported = -1;
if (v2_supported != -1)
return v2_supported;
args2 = (struct btrfs_ioctl_search_args_v2 *)args2_buf;
sk = &(args2->key);
/*
* Search for the extent tree item in the root tree.
*/
sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
sk->min_objectid = BTRFS_EXTENT_TREE_OBJECTID;
sk->max_objectid = BTRFS_EXTENT_TREE_OBJECTID;
sk->min_type = BTRFS_ROOT_ITEM_KEY;
sk->max_type = BTRFS_ROOT_ITEM_KEY;
sk->min_offset = 0;
sk->max_offset = (u64)-1;
sk->min_transid = 0;
sk->max_transid = (u64)-1;
sk->nr_items = 1;
args2->buf_size = args2_size - sizeof(struct btrfs_ioctl_search_args_v2);
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH_V2, args2);
if (ret == -EOPNOTSUPP)
v2_supported = 0;
else if (ret == 0)
v2_supported = 1;
else
return ret;
return v2_supported;
}
int btrfs_check_nodesize(u32 nodesize, u32 sectorsize, u64 features)
{
if (nodesize < sectorsize) {
error("illegal nodesize %u (smaller than %u)",
nodesize, sectorsize);
return -1;
} else if (nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
error("illegal nodesize %u (larger than %u)",
nodesize, BTRFS_MAX_METADATA_BLOCKSIZE);
return -1;
} else if (nodesize & (sectorsize - 1)) {
error("illegal nodesize %u (not aligned to %u)",
nodesize, sectorsize);
return -1;
} else if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS &&
nodesize != sectorsize) {
error("illegal nodesize %u (not equal to %u for mixed block group)",
nodesize, sectorsize);
return -1;
}
return 0;
}
/*
* Copy a path argument from SRC to DEST and check the SRC length if it's at
* most PATH_MAX and fits into DEST. DESTLEN is supposed to be exact size of
* the buffer.
* The destination buffer is zero terminated.
* Return < 0 for error, 0 otherwise.
*/
int arg_copy_path(char *dest, const char *src, int destlen)
{
size_t len = strlen(src);
if (len >= PATH_MAX || len >= destlen)
return -ENAMETOOLONG;
__strncpy_null(dest, src, destlen);
return 0;
}
unsigned int get_unit_mode_from_arg(int *argc, char *argv[], int df_mode)
{
unsigned int unit_mode = UNITS_DEFAULT;
int arg_i;
int arg_end;
for (arg_i = 0; arg_i < *argc; arg_i++) {
if (!strcmp(argv[arg_i], "--"))
break;
if (!strcmp(argv[arg_i], "--raw")) {
unit_mode = UNITS_RAW;
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--human-readable")) {
unit_mode = UNITS_HUMAN_BINARY;
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--iec")) {
units_set_mode(&unit_mode, UNITS_BINARY);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--si")) {
units_set_mode(&unit_mode, UNITS_DECIMAL);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--kbytes")) {
units_set_base(&unit_mode, UNITS_KBYTES);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--mbytes")) {
units_set_base(&unit_mode, UNITS_MBYTES);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--gbytes")) {
units_set_base(&unit_mode, UNITS_GBYTES);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "--tbytes")) {
units_set_base(&unit_mode, UNITS_TBYTES);
argv[arg_i] = NULL;
continue;
}
if (!df_mode)
continue;
if (!strcmp(argv[arg_i], "-b")) {
unit_mode = UNITS_RAW;
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "-h")) {
unit_mode = UNITS_HUMAN_BINARY;
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "-H")) {
unit_mode = UNITS_HUMAN_DECIMAL;
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "-k")) {
units_set_base(&unit_mode, UNITS_KBYTES);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "-m")) {
units_set_base(&unit_mode, UNITS_MBYTES);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "-g")) {
units_set_base(&unit_mode, UNITS_GBYTES);
argv[arg_i] = NULL;
continue;
}
if (!strcmp(argv[arg_i], "-t")) {
units_set_base(&unit_mode, UNITS_TBYTES);
argv[arg_i] = NULL;
continue;
}
}
for (arg_i = 0, arg_end = 0; arg_i < *argc; arg_i++) {
if (!argv[arg_i])
continue;
argv[arg_end] = argv[arg_i];
arg_end++;
}
*argc = arg_end;
return unit_mode;
}
int string_is_numerical(const char *str)
{
if (!(*str >= '0' && *str <= '9'))
return 0;
while (*str >= '0' && *str <= '9')
str++;
if (*str != '\0')
return 0;
return 1;
}
/*
* Preprocess @argv with getopt_long to reorder options and consume the "--"
* option separator.
* Unknown short and long options are reported, optionally the @usage is printed
* before exit.
*/
void clean_args_no_options(int argc, char *argv[], const char * const *usagestr)
{
static const struct option long_options[] = {
{NULL, 0, NULL, 0}
};
while (1) {
int c = getopt_long(argc, argv, "", long_options, NULL);
if (c < 0)
break;
switch (c) {
default:
if (usagestr)
usage(usagestr);
}
}
}
/*
* Same as clean_args_no_options but pass through arguments that could look
* like short options. Eg. reisze which takes a negative resize argument like
* '-123M' .
*
* This accepts only two forms:
* - "-- option1 option2 ..."
* - "option1 option2 ..."
*/
void clean_args_no_options_relaxed(int argc, char *argv[], const char * const *usagestr)
{
if (argc <= 1)
return;
if (strcmp(argv[1], "--") == 0)
optind = 2;
}
/* Subvolume helper functions */
/*
* test if name is a correct subvolume name
* this function return
* 0-> name is not a correct subvolume name
* 1-> name is a correct subvolume name
*/
int test_issubvolname(const char *name)
{
return name[0] != '\0' && !strchr(name, '/') &&
strcmp(name, ".") && strcmp(name, "..");
}
/*
* Test if path is a subvolume
* Returns:
* 0 - path exists but it is not a subvolume
* 1 - path exists and it is a subvolume
* < 0 - error
*/
int test_issubvolume(const char *path)
{
struct stat st;
struct statfs stfs;
int res;
res = stat(path, &st);
if (res < 0)
return -errno;
if (st.st_ino != BTRFS_FIRST_FREE_OBJECTID || !S_ISDIR(st.st_mode))
return 0;
res = statfs(path, &stfs);
if (res < 0)
return -errno;
return (int)stfs.f_type == BTRFS_SUPER_MAGIC;
}
const char *subvol_strip_mountpoint(const char *mnt, const char *full_path)
{
int len = strlen(mnt);
if (!len)
return full_path;
if (mnt[len - 1] != '/')
len += 1;
return full_path + len;
}
/*
* Returns
* <0: Std error
* 0: All fine
* 1: Error; and error info printed to the terminal. Fixme.
* 2: If the fullpath is root tree instead of subvol tree
*/
int get_subvol_info(const char *fullpath, struct root_info *get_ri)
{
u64 sv_id;
int ret = 1;
int fd = -1;
int mntfd = -1;
char *mnt = NULL;
const char *svpath = NULL;
DIR *dirstream1 = NULL;
DIR *dirstream2 = NULL;
ret = test_issubvolume(fullpath);
if (ret < 0)
return ret;
if (!ret) {
error("not a subvolume: %s", fullpath);
return 1;
}
ret = find_mount_root(fullpath, &mnt);
if (ret < 0)
return ret;
if (ret > 0) {
error("%s doesn't belong to btrfs mount point", fullpath);
return 1;
}
ret = 1;
svpath = subvol_strip_mountpoint(mnt, fullpath);
fd = btrfs_open_dir(fullpath, &dirstream1, 1);
if (fd < 0)
goto out;
ret = btrfs_list_get_path_rootid(fd, &sv_id);
if (ret) {
error("can't get rootid for '%s'", fullpath);
goto out;
}
mntfd = btrfs_open_dir(mnt, &dirstream2, 1);
if (mntfd < 0)
goto out;
if (sv_id == BTRFS_FS_TREE_OBJECTID) {
ret = 2;
/*
* So that caller may decide if thats an error or just fine.
*/
goto out;
}
memset(get_ri, 0, sizeof(*get_ri));
get_ri->root_id = sv_id;
ret = btrfs_get_subvol(mntfd, get_ri);
if (ret)
error("can't find '%s': %d", svpath, ret);
out:
close_file_or_dir(mntfd, dirstream2);
close_file_or_dir(fd, dirstream1);
free(mnt);
return ret;
}
void init_rand_seed(u64 seed)
{
int i;
/* only use the last 48 bits */
for (i = 0; i < 3; i++) {
rand_seed[i] = (unsigned short)(seed ^ (unsigned short)(-1));
seed >>= 16;
}
rand_seed_initlized = 1;
}
static void __init_seed(void)
{
struct timeval tv;
int ret;
int fd;
if(rand_seed_initlized)
return;
/* Use urandom as primary seed source. */
fd = open("/dev/urandom", O_RDONLY);
if (fd >= 0) {
ret = read(fd, rand_seed, sizeof(rand_seed));
close(fd);
if (ret < sizeof(rand_seed))
goto fallback;
} else {
fallback:
/* Use time and pid as fallback seed */
warning("failed to read /dev/urandom, use time and pid as random seed");
gettimeofday(&tv, 0);
rand_seed[0] = getpid() ^ (tv.tv_sec & 0xFFFF);
rand_seed[1] = getppid() ^ (tv.tv_usec & 0xFFFF);
rand_seed[2] = (tv.tv_sec ^ tv.tv_usec) >> 16;
}
rand_seed_initlized = 1;
}
u32 rand_u32(void)
{
__init_seed();
/*
* Don't use nrand48, its range is [0,2^31) The highest bit will alwasy
* be 0. Use jrand48 to include the highest bit.
*/
return (u32)jrand48(rand_seed);
}
unsigned int rand_range(unsigned int upper)
{
__init_seed();
/*
* Use the full 48bits to mod, which would be more uniformly
* distributed
*/
return (unsigned int)(jrand48(rand_seed) % upper);
}
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