btrfs-progs/mkfs/rootdir.c
Vladimir Panteleev 11e126b162 btrfs-progs: mkfs: fix xattr enumeration
Use the return value of listxattr instead of tokenizing.

The end of the extended attribute list is indicated by the return value,
not an empty list item (two consecutive NULs). Using strtok in this way
thus sometimes caused add_xattr_item to reuse stack data in xattr_list
from the previous invocation, thus querying attributes that are not
actually in the file's xattr list.

Issue: #194
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Vladimir Panteleev <git@vladimir.panteleev.md>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-10-14 17:27:56 +02:00

960 lines
23 KiB
C

/*
* Copyright (C) 2017 SUSE. 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.
*/
#include "kerncompat.h"
#include "androidcompat.h"
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <linux/limits.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#include <ftw.h>
#include "ctree.h"
#include "volumes.h"
#include "common/internal.h"
#include "disk-io.h"
#include "common/messages.h"
#include "transaction.h"
#include "common/utils.h"
#include "mkfs/rootdir.h"
#include "mkfs/common.h"
#include "send-utils.h"
static u32 fs_block_size;
static u64 index_cnt = 2;
/*
* Size estimate will be done using the following data:
* 1) Number of inodes
* Since we will later shrink the fs, over-estimate is completely fine here
* as long as our estimate ensures we can populate the image without ENOSPC.
* So we only record how many inodes there are, and account the maximum
* space for each inode.
*
* 2) Data space for each (regular) inode
* To estimate data chunk size.
* Don't care if it can fit as an inline extent.
* Always round them up to sectorsize.
*/
static u64 ftw_meta_nr_inode;
static u64 ftw_data_size;
static int add_directory_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid,
ino_t parent_inum, const char *name,
struct stat *st, int *dir_index_cnt)
{
int ret;
int name_len;
struct btrfs_key location;
u8 filetype = 0;
name_len = strlen(name);
location.objectid = objectid;
location.offset = 0;
location.type = BTRFS_INODE_ITEM_KEY;
if (S_ISDIR(st->st_mode))
filetype = BTRFS_FT_DIR;
if (S_ISREG(st->st_mode))
filetype = BTRFS_FT_REG_FILE;
if (S_ISLNK(st->st_mode))
filetype = BTRFS_FT_SYMLINK;
if (S_ISSOCK(st->st_mode))
filetype = BTRFS_FT_SOCK;
if (S_ISCHR(st->st_mode))
filetype = BTRFS_FT_CHRDEV;
if (S_ISBLK(st->st_mode))
filetype = BTRFS_FT_BLKDEV;
if (S_ISFIFO(st->st_mode))
filetype = BTRFS_FT_FIFO;
ret = btrfs_insert_dir_item(trans, root, name, name_len,
parent_inum, &location,
filetype, index_cnt);
if (ret)
return ret;
ret = btrfs_insert_inode_ref(trans, root, name, name_len,
objectid, parent_inum, index_cnt);
*dir_index_cnt = index_cnt;
index_cnt++;
return ret;
}
static int fill_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode_item *dst, struct stat *src)
{
u64 blocks = 0;
u64 sectorsize = root->fs_info->sectorsize;
/*
* btrfs_inode_item has some reserved fields
* and represents on-disk inode entry, so
* zero everything to prevent information leak
*/
memset(dst, 0, sizeof(*dst));
btrfs_set_stack_inode_generation(dst, trans->transid);
btrfs_set_stack_inode_size(dst, src->st_size);
btrfs_set_stack_inode_nbytes(dst, 0);
btrfs_set_stack_inode_block_group(dst, 0);
btrfs_set_stack_inode_nlink(dst, src->st_nlink);
btrfs_set_stack_inode_uid(dst, src->st_uid);
btrfs_set_stack_inode_gid(dst, src->st_gid);
btrfs_set_stack_inode_mode(dst, src->st_mode);
btrfs_set_stack_inode_rdev(dst, 0);
btrfs_set_stack_inode_flags(dst, 0);
btrfs_set_stack_timespec_sec(&dst->atime, src->st_atime);
btrfs_set_stack_timespec_nsec(&dst->atime, 0);
btrfs_set_stack_timespec_sec(&dst->ctime, src->st_ctime);
btrfs_set_stack_timespec_nsec(&dst->ctime, 0);
btrfs_set_stack_timespec_sec(&dst->mtime, src->st_mtime);
btrfs_set_stack_timespec_nsec(&dst->mtime, 0);
btrfs_set_stack_timespec_sec(&dst->otime, 0);
btrfs_set_stack_timespec_nsec(&dst->otime, 0);
if (S_ISDIR(src->st_mode)) {
btrfs_set_stack_inode_size(dst, 0);
btrfs_set_stack_inode_nlink(dst, 1);
}
if (S_ISREG(src->st_mode)) {
btrfs_set_stack_inode_size(dst, (u64)src->st_size);
if (src->st_size <= BTRFS_MAX_INLINE_DATA_SIZE(root->fs_info) &&
src->st_size < sectorsize)
btrfs_set_stack_inode_nbytes(dst, src->st_size);
else {
blocks = src->st_size / sectorsize;
if (src->st_size % sectorsize)
blocks += 1;
blocks *= sectorsize;
btrfs_set_stack_inode_nbytes(dst, blocks);
}
}
if (S_ISLNK(src->st_mode))
btrfs_set_stack_inode_nbytes(dst, src->st_size + 1);
return 0;
}
static int directory_select(const struct direct *entry)
{
if (entry->d_name[0] == '.' &&
(entry->d_name[1] == 0 ||
(entry->d_name[1] == '.' && entry->d_name[2] == 0)))
return 0;
return 1;
}
static void free_namelist(struct direct **files, int count)
{
int i;
if (count < 0)
return;
for (i = 0; i < count; ++i)
free(files[i]);
free(files);
}
static u64 calculate_dir_inode_size(const char *dirname)
{
int count, i;
struct direct **files, *cur_file;
u64 dir_inode_size = 0;
count = scandir(dirname, &files, directory_select, NULL);
for (i = 0; i < count; i++) {
cur_file = files[i];
dir_inode_size += strlen(cur_file->d_name);
}
free_namelist(files, count);
dir_inode_size *= 2;
return dir_inode_size;
}
static int add_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct stat *st, const char *name,
u64 self_objectid,
struct btrfs_inode_item *inode_ret)
{
int ret;
struct btrfs_inode_item btrfs_inode;
u64 objectid;
u64 inode_size = 0;
fill_inode_item(trans, root, &btrfs_inode, st);
objectid = self_objectid;
if (S_ISDIR(st->st_mode)) {
inode_size = calculate_dir_inode_size(name);
btrfs_set_stack_inode_size(&btrfs_inode, inode_size);
}
ret = btrfs_insert_inode(trans, root, objectid, &btrfs_inode);
*inode_ret = btrfs_inode;
return ret;
}
static int add_xattr_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid,
const char *file_name)
{
int ret;
int cur_name_len;
char xattr_list[XATTR_LIST_MAX];
char *xattr_list_end;
char *cur_name;
char cur_value[XATTR_SIZE_MAX];
ret = llistxattr(file_name, xattr_list, XATTR_LIST_MAX);
if (ret < 0) {
if (errno == ENOTSUP)
return 0;
error("getting a list of xattr failed for %s: %m", file_name);
return ret;
}
if (ret == 0)
return ret;
xattr_list_end = xattr_list + ret;
cur_name = xattr_list;
while (cur_name < xattr_list_end) {
cur_name_len = strlen(cur_name);
ret = lgetxattr(file_name, cur_name, cur_value, XATTR_SIZE_MAX);
if (ret < 0) {
if (errno == ENOTSUP)
return 0;
error("getting a xattr value failed for %s attr %s: %m",
file_name, cur_name);
return ret;
}
ret = btrfs_insert_xattr_item(trans, root, cur_name,
cur_name_len, cur_value,
ret, objectid);
if (ret) {
errno = -ret;
error("inserting a xattr item failed for %s: %m",
file_name);
}
cur_name += cur_name_len + 1;
}
return ret;
}
static int add_symbolic_link(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, const char *path_name)
{
int ret;
char buf[PATH_MAX];
ret = readlink(path_name, buf, sizeof(buf));
if (ret <= 0) {
error("readlink failed for %s: %m", path_name);
goto fail;
}
if (ret >= sizeof(buf)) {
error("symlink too long for %s", path_name);
ret = -1;
goto fail;
}
buf[ret] = '\0'; /* readlink does not do it for us */
ret = btrfs_insert_inline_extent(trans, root, objectid, 0,
buf, ret + 1);
fail:
return ret;
}
static int add_file_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode_item *btrfs_inode, u64 objectid,
struct stat *st, const char *path_name)
{
int ret = -1;
ssize_t ret_read;
u64 bytes_read = 0;
struct btrfs_key key;
int blocks;
u32 sectorsize = root->fs_info->sectorsize;
u64 first_block = 0;
u64 file_pos = 0;
u64 cur_bytes;
u64 total_bytes;
struct extent_buffer *eb = NULL;
int fd;
if (st->st_size == 0)
return 0;
fd = open(path_name, O_RDONLY);
if (fd == -1) {
error("cannot open %s: %m", path_name);
return ret;
}
blocks = st->st_size / sectorsize;
if (st->st_size % sectorsize)
blocks += 1;
if (st->st_size <= BTRFS_MAX_INLINE_DATA_SIZE(root->fs_info) &&
st->st_size < sectorsize) {
char *buffer = malloc(st->st_size);
if (!buffer) {
ret = -ENOMEM;
goto end;
}
ret_read = pread64(fd, buffer, st->st_size, bytes_read);
if (ret_read == -1) {
error("cannot read %s at offset %llu length %llu: %m",
path_name, (unsigned long long)bytes_read,
(unsigned long long)st->st_size);
free(buffer);
goto end;
}
ret = btrfs_insert_inline_extent(trans, root, objectid, 0,
buffer, st->st_size);
free(buffer);
goto end;
}
/* round up our st_size to the FS blocksize */
total_bytes = (u64)blocks * sectorsize;
/*
* do our IO in extent buffers so it can work
* against any raid type
*/
eb = calloc(1, sizeof(*eb) + sectorsize);
if (!eb) {
ret = -ENOMEM;
goto end;
}
again:
/*
* keep our extent size at 1MB max, this makes it easier to work inside
* the tiny block groups created during mkfs
*/
cur_bytes = min(total_bytes, (u64)SZ_1M);
ret = btrfs_reserve_extent(trans, root, cur_bytes, 0, 0, (u64)-1,
&key, 1);
if (ret)
goto end;
first_block = key.objectid;
bytes_read = 0;
while (bytes_read < cur_bytes) {
memset(eb->data, 0, sectorsize);
ret_read = pread64(fd, eb->data, sectorsize, file_pos +
bytes_read);
if (ret_read == -1) {
error("cannot read %s at offset %llu length %llu: %m",
path_name,
(unsigned long long)file_pos + bytes_read,
(unsigned long long)sectorsize);
goto end;
}
eb->start = first_block + bytes_read;
eb->len = sectorsize;
/*
* we're doing the csum before we record the extent, but
* that's ok
*/
ret = btrfs_csum_file_block(trans, root->fs_info->csum_root,
first_block + bytes_read + sectorsize,
first_block + bytes_read,
eb->data, sectorsize);
if (ret)
goto end;
ret = write_and_map_eb(root->fs_info, eb);
if (ret) {
error("failed to write %s", path_name);
goto end;
}
bytes_read += sectorsize;
}
if (bytes_read) {
ret = btrfs_record_file_extent(trans, root, objectid,
btrfs_inode, file_pos, first_block, cur_bytes);
if (ret)
goto end;
}
file_pos += cur_bytes;
total_bytes -= cur_bytes;
if (total_bytes)
goto again;
end:
free(eb);
close(fd);
return ret;
}
static int traverse_directory(struct btrfs_trans_handle *trans,
struct btrfs_root *root, const char *dir_name,
struct directory_name_entry *dir_head)
{
int ret = 0;
struct btrfs_inode_item cur_inode;
struct btrfs_inode_item *inode_item;
int count, i, dir_index_cnt;
struct direct **files;
struct stat st;
struct directory_name_entry *dir_entry, *parent_dir_entry;
struct direct *cur_file;
ino_t parent_inum, cur_inum;
ino_t highest_inum = 0;
const char *parent_dir_name;
struct btrfs_path path;
struct extent_buffer *leaf;
struct btrfs_key root_dir_key;
u64 root_dir_inode_size = 0;
/* Add list for source directory */
dir_entry = malloc(sizeof(struct directory_name_entry));
if (!dir_entry)
return -ENOMEM;
dir_entry->dir_name = dir_name;
dir_entry->path = realpath(dir_name, NULL);
if (!dir_entry->path) {
error("realpath failed for %s: %m", dir_name);
ret = -1;
goto fail_no_dir;
}
parent_inum = highest_inum + BTRFS_FIRST_FREE_OBJECTID;
dir_entry->inum = parent_inum;
list_add_tail(&dir_entry->list, &dir_head->list);
btrfs_init_path(&path);
root_dir_key.objectid = btrfs_root_dirid(&root->root_item);
root_dir_key.offset = 0;
root_dir_key.type = BTRFS_INODE_ITEM_KEY;
ret = btrfs_lookup_inode(trans, root, &path, &root_dir_key, 1);
if (ret) {
error("failed to lookup root dir: %d", ret);
goto fail_no_dir;
}
leaf = path.nodes[0];
inode_item = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_inode_item);
root_dir_inode_size = calculate_dir_inode_size(dir_name);
btrfs_set_inode_size(leaf, inode_item, root_dir_inode_size);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(&path);
do {
parent_dir_entry = list_entry(dir_head->list.next,
struct directory_name_entry,
list);
list_del(&parent_dir_entry->list);
parent_inum = parent_dir_entry->inum;
parent_dir_name = parent_dir_entry->dir_name;
if (chdir(parent_dir_entry->path)) {
error("chdir failed for %s: %m",
parent_dir_name);
ret = -1;
goto fail_no_files;
}
count = scandir(parent_dir_entry->path, &files,
directory_select, NULL);
if (count == -1) {
error("scandir failed for %s: %m",
parent_dir_name);
ret = -1;
goto fail;
}
for (i = 0; i < count; i++) {
cur_file = files[i];
if (lstat(cur_file->d_name, &st) == -1) {
error("lstat failed for %s: %m",
cur_file->d_name);
ret = -1;
goto fail;
}
cur_inum = st.st_ino;
ret = add_directory_items(trans, root,
cur_inum, parent_inum,
cur_file->d_name,
&st, &dir_index_cnt);
if (ret) {
error("unable to add directory items for %s: %d",
cur_file->d_name, ret);
goto fail;
}
ret = add_inode_items(trans, root, &st,
cur_file->d_name, cur_inum,
&cur_inode);
if (ret == -EEXIST) {
if (st.st_nlink <= 1) {
error(
"item %s already exists but has wrong st_nlink %lu <= 1",
cur_file->d_name,
(unsigned long)st.st_nlink);
goto fail;
}
ret = 0;
continue;
}
if (ret) {
error("unable to add inode items for %s: %d",
cur_file->d_name, ret);
goto fail;
}
ret = add_xattr_item(trans, root,
cur_inum, cur_file->d_name);
if (ret) {
error("unable to add xattr items for %s: %d",
cur_file->d_name, ret);
if (ret != -ENOTSUP)
goto fail;
}
if (S_ISDIR(st.st_mode)) {
char tmp[PATH_MAX];
dir_entry = malloc(sizeof(*dir_entry));
if (!dir_entry) {
ret = -ENOMEM;
goto fail;
}
dir_entry->dir_name = cur_file->d_name;
if (path_cat_out(tmp, parent_dir_entry->path,
cur_file->d_name)) {
error("invalid path: %s/%s",
parent_dir_entry->path,
cur_file->d_name);
ret = -EINVAL;
goto fail;
}
dir_entry->path = strdup(tmp);
if (!dir_entry->path) {
error("not enough memory to store path");
ret = -ENOMEM;
goto fail;
}
dir_entry->inum = cur_inum;
list_add_tail(&dir_entry->list,
&dir_head->list);
} else if (S_ISREG(st.st_mode)) {
ret = add_file_items(trans, root, &cur_inode,
cur_inum, &st,
cur_file->d_name);
if (ret) {
error("unable to add file items for %s: %d",
cur_file->d_name, ret);
goto fail;
}
} else if (S_ISLNK(st.st_mode)) {
ret = add_symbolic_link(trans, root,
cur_inum, cur_file->d_name);
if (ret) {
error("unable to add symlink for %s: %d",
cur_file->d_name, ret);
goto fail;
}
}
}
free_namelist(files, count);
free(parent_dir_entry->path);
free(parent_dir_entry);
index_cnt = 2;
} while (!list_empty(&dir_head->list));
out:
return !!ret;
fail:
free_namelist(files, count);
fail_no_files:
free(parent_dir_entry);
goto out;
fail_no_dir:
free(dir_entry);
goto out;
}
int btrfs_mkfs_fill_dir(const char *source_dir, struct btrfs_root *root,
bool verbose)
{
int ret;
struct btrfs_trans_handle *trans;
struct stat root_st;
struct directory_name_entry dir_head;
struct directory_name_entry *dir_entry = NULL;
ret = lstat(source_dir, &root_st);
if (ret) {
error("unable to lstat %s: %m", source_dir);
ret = -errno;
goto out;
}
INIT_LIST_HEAD(&dir_head.list);
trans = btrfs_start_transaction(root, 1);
BUG_ON(IS_ERR(trans));
ret = traverse_directory(trans, root, source_dir, &dir_head);
if (ret) {
error("unable to traverse directory %s: %d", source_dir, ret);
goto fail;
}
ret = btrfs_commit_transaction(trans, root);
if (ret) {
error("transaction commit failed: %d", ret);
goto out;
}
if (verbose)
printf("Making image is completed.\n");
return 0;
fail:
/*
* Since we don't have btrfs_abort_transaction() yet, uncommitted trans
* will trigger a BUG_ON().
*
* However before mkfs is fully finished, the magic number is invalid,
* so even we commit transaction here, the fs still can't be mounted.
*
* To do a graceful error out, here we commit transaction as a
* workaround.
* Since we have already hit some problem, the return value doesn't
* matter now.
*/
btrfs_commit_transaction(trans, root);
while (!list_empty(&dir_head.list)) {
dir_entry = list_entry(dir_head.list.next,
struct directory_name_entry, list);
list_del(&dir_entry->list);
free(dir_entry->path);
free(dir_entry);
}
out:
return ret;
}
static int ftw_add_entry_size(const char *fpath, const struct stat *st,
int type, struct FTW *ftwbuf)
{
/*
* Failed to read the directory, mostly due to EPERM. Abort ASAP, so
* we don't need to populate the fs.
*/
if (type == FTW_DNR || type == FTW_NS)
return -EPERM;
if (S_ISREG(st->st_mode))
ftw_data_size += round_up(st->st_size, fs_block_size);
ftw_meta_nr_inode++;
return 0;
}
u64 btrfs_mkfs_size_dir(const char *dir_name, u32 sectorsize, u64 min_dev_size,
u64 meta_profile, u64 data_profile)
{
u64 total_size = 0;
int ret;
u64 meta_size = 0; /* Based on @ftw_meta_nr_inode */
u64 meta_chunk_size = 0; /* Based on @meta_size */
u64 data_chunk_size = 0; /* Based on @ftw_data_size */
u64 meta_threshold = SZ_8M;
u64 data_threshold = SZ_8M;
float data_multiplier = 1;
float meta_multiplier = 1;
fs_block_size = sectorsize;
ftw_data_size = 0;
ftw_meta_nr_inode = 0;
/*
* Symbolic link is not followed when creating files, so no need to
* follow them here.
*/
ret = nftw(dir_name, ftw_add_entry_size, 10, FTW_PHYS);
if (ret < 0) {
error("ftw subdir walk of %s failed: %m", dir_name);
exit(1);
}
/*
* Maximum metadata usage for every inode, which will be PATH_MAX
* for the following items:
* 1) DIR_ITEM
* 2) DIR_INDEX
* 3) INODE_REF
*
* Plus possible inline extent size, which is sectorsize.
*
* And finally, allow metadata usage to increase with data size.
* Follow the old kernel 8:1 data:meta ratio.
* This is especially important for --rootdir, as the file extent size
* upper limit is 1M, instead of 128M in kernel.
* This can bump meta usage easily.
*/
meta_size = ftw_meta_nr_inode * (PATH_MAX * 3 + sectorsize) +
ftw_data_size / 8;
/* Minimal chunk size from btrfs_alloc_chunk(). */
if (meta_profile & BTRFS_BLOCK_GROUP_DUP) {
meta_threshold = SZ_32M;
meta_multiplier = 2;
}
if (data_profile & BTRFS_BLOCK_GROUP_DUP) {
data_threshold = SZ_64M;
data_multiplier = 2;
}
/*
* Only when the usage is larger than the minimal chunk size (threshold)
* we need to allocate new chunk, or the initial chunk in the image is
* large enough.
*/
if (meta_size > meta_threshold)
meta_chunk_size = (round_up(meta_size, meta_threshold) -
meta_threshold) * meta_multiplier;
if (ftw_data_size > data_threshold)
data_chunk_size = (round_up(ftw_data_size, data_threshold) -
data_threshold) * data_multiplier;
total_size = data_chunk_size + meta_chunk_size + min_dev_size;
return total_size;
}
/*
* Get the end position of the last device extent for given @devid;
* @size_ret is exclusive (means it should be aligned to sectorsize)
*/
static int get_device_extent_end(struct btrfs_fs_info *fs_info,
u64 devid, u64 *size_ret)
{
struct btrfs_root *dev_root = fs_info->dev_root;
struct btrfs_key key;
struct btrfs_path path;
struct btrfs_dev_extent *de;
int ret;
key.objectid = devid;
key.type = BTRFS_DEV_EXTENT_KEY;
key.offset = (u64)-1;
btrfs_init_path(&path);
ret = btrfs_search_slot(NULL, dev_root, &key, &path, 0, 0);
/* Not really possible */
BUG_ON(ret == 0);
ret = btrfs_previous_item(dev_root, &path, devid, BTRFS_DEV_EXTENT_KEY);
if (ret < 0)
goto out;
/* No dev_extent at all, not really possible for rootdir case */
if (ret > 0) {
*size_ret = 0;
ret = -EUCLEAN;
goto out;
}
btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
de = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_dev_extent);
*size_ret = key.offset + btrfs_dev_extent_length(path.nodes[0], de);
out:
btrfs_release_path(&path);
return ret;
}
/*
* Set device size to @new_size.
*
* Only used for --rootdir option.
* We will need to reset the following values:
* 1) dev item in chunk tree
* 2) super->dev_item
* 3) super->total_bytes
*/
static int set_device_size(struct btrfs_fs_info *fs_info,
struct btrfs_device *device, u64 new_size)
{
struct btrfs_root *chunk_root = fs_info->chunk_root;
struct btrfs_trans_handle *trans;
struct btrfs_dev_item *di;
struct btrfs_path path;
struct btrfs_key key;
int ret;
/*
* Update in-memory device->total_bytes, so that at trans commit time,
* super->dev_item will also get updated
*/
device->total_bytes = new_size;
btrfs_init_path(&path);
/* Update device item in chunk tree */
trans = btrfs_start_transaction(chunk_root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
errno = -ret;
error("failed to start transaction: %d (%m)", ret);
return ret;
}
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(trans, chunk_root, &key, &path, 0, 1);
if (ret < 0)
goto err;
if (ret > 0)
ret = -ENOENT;
di = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_dev_item);
btrfs_set_device_total_bytes(path.nodes[0], di, new_size);
btrfs_mark_buffer_dirty(path.nodes[0]);
/*
* Update super->total_bytes, since it's only used for --rootdir,
* there is only one device, just use the @new_size.
*/
btrfs_set_super_total_bytes(fs_info->super_copy, new_size);
/*
* Commit transaction to reflect the updated super->total_bytes and
* super->dev_item
*/
ret = btrfs_commit_transaction(trans, chunk_root);
if (ret < 0) {
errno = -ret;
error("failed to commit current transaction: %d (%m)", ret);
}
btrfs_release_path(&path);
return ret;
err:
btrfs_release_path(&path);
/*
* Committing the transaction here won't cause problems since the fs
* still has an invalid magic number, and something wrong already
* happened, we don't care the return value anyway.
*/
btrfs_commit_transaction(trans, chunk_root);
return ret;
}
int btrfs_mkfs_shrink_fs(struct btrfs_fs_info *fs_info, u64 *new_size_ret,
bool shrink_file_size)
{
u64 new_size;
struct btrfs_device *device;
struct list_head *cur;
struct stat64 file_stat;
int nr_devs = 0;
int ret;
list_for_each(cur, &fs_info->fs_devices->devices)
nr_devs++;
if (nr_devs > 1) {
error("cannot shrink fs with more than 1 device");
return -ENOTTY;
}
ret = get_device_extent_end(fs_info, 1, &new_size);
if (ret < 0) {
errno = -ret;
error("failed to get minimal device size: %d (%m)", ret);
return ret;
}
BUG_ON(!IS_ALIGNED(new_size, fs_info->sectorsize));
device = list_entry(fs_info->fs_devices->devices.next,
struct btrfs_device, dev_list);
ret = set_device_size(fs_info, device, new_size);
if (ret < 0)
return ret;
if (new_size_ret)
*new_size_ret = new_size;
if (shrink_file_size) {
ret = fstat64(device->fd, &file_stat);
if (ret < 0) {
error("failed to stat devid %llu: %m", device->devid);
return ret;
}
if (!S_ISREG(file_stat.st_mode))
return ret;
ret = ftruncate64(device->fd, new_size);
if (ret < 0) {
error("failed to truncate device file of devid %llu: %m",
device->devid);
return ret;
}
}
return ret;
}