btrfs-progs/mkfs/rootdir.c
Qu Wenruo 2cdc8dddbf btrfs-progs: mkfs: offset inode numbers of the source filesystem
[BUG]
When running mkfs tests on a newly rebooted minimal system, it can cause
mkfs/009 to fail.

The reproduce steps requires /tmp to has minimal files in the first
place.

  # mkdir /tmp/rootdir
  # xfs_io -f -c "pwrite 0 16k" /tmp/rootdir
  # mkfs.btrfs --rootdir /tmp/rootdir -f $dev
  # btrfs check $dev
  Opening filesystem to check...
  Checking filesystem on /dev/test/scratch1
  UUID: 6821b3db-f056-4c18-b797-32679dcd4272
  [1/7] checking root items
  [2/7] checking extents
  data backref 13631488 root 5 owner 170 offset 0 num_refs 0 not found in extent tree
  incorrect local backref count on 13631488 root 5 owner 170 offset 0 found 1 wanted 0 back 0x55ff6cd72260
  backref 13631488 root 5 not referenced back 0x55ff6cd4c1f0
  incorrect global backref count on 13631488 found 2 wanted 1
  backpointer mismatch on [13631488 16384]
  ERROR: errors found in extent allocation tree or chunk allocation

[CAUSE]
The extent tree has the following weird item:

	item 0 key (13631488 EXTENT_ITEM 16384) itemoff 16250 itemsize 33
		refs 1 gen 0 flags DATA
		tree block backref root FS_TREE

This is an extent item for data, thus it should not have an inline tree
backref.

Then checking the fs tree:

	item 0 key (170 INODE_ITEM 0) itemoff 16123 itemsize 160
		generation 7 transid 0 size 16384 nbytes 16384
		block group 0 mode 100600 links 1 uid 1000 gid 1000 rdev 0
		sequence 0 flags 0x0(none)
		atime 1664866393.0 (2022-10-04 14:53:13)
		ctime 1664863510.0 (2022-10-04 14:05:10)
		mtime 1664863455.0 (2022-10-04 14:04:15)
		otime 0.0 (1970-01-01 08:00:00)

There is an inode item before the root dir inode.

And that inode number 170 is causing the problem.

In traverse_directory(), we use the inode number reported from stat()
directly as btrfs inode number, and pass it to
btrfs_record_file_extent(), which finally calls btrfs_inc_extent_ref(),
with above 170 passed as @owner parameter.

But inside btrfs_inc_extent_ref() we use that @owner value to determine
if it's a data backref.
Since we got a smaller than BTRFS_FIRST_FREE_OBJECTID, btrfs treats it
as tree block, and cause the above problem.

[FIX]
As a quick fix, always add BTRFS_FIRST_FREE_OBJECTID to all inode number
directly grabbed from stat().

And add an ASSERT() in __btrfs_record_file_extent() to catch unexpected
objectid.

This is not a perfect solution, as the resulted fs will has a huge gap
in its inodes:

	item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
	item 4 key (426 INODE_ITEM 0) itemoff 15883 itemsize 160

For a proper fix, we should allocate new btrfs inode numbers in a
sequential order, but that would be another series of patches.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-10-11 09:08:10 +02:00

982 lines
24 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; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include "kerncompat.h"
#include <sys/stat.h>
#include <sys/xattr.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#include <ftw.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "kernel-lib/sizes.h"
#include "kernel-shared/extent_io.h"
#include "kernel-shared/ctree.h"
#include "kernel-shared/volumes.h"
#include "kernel-shared/disk-io.h"
#include "kernel-shared/transaction.h"
#include "common/internal.h"
#include "common/messages.h"
#include "common/path-utils.h"
#include "mkfs/rootdir.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 dirent *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 dirent **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 dirent **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, 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 %u: %m",
path_name, file_pos + bytes_read, sectorsize);
goto end;
}
eb->start = first_block + bytes_read;
eb->len = sectorsize;
eb->fs_info = root->fs_info;
/*
* we're doing the csum before we record the extent, but
* that's ok
*/
ret = btrfs_csum_file_block(trans,
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 dirent **files;
struct stat st;
struct directory_name_entry *dir_entry, *parent_dir_entry;
struct dirent *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;
}
/*
* We can not directly use the source ino number,
* as there is a chance that the ino is smaller than
* BTRFS_FIRST_FREE_OBJECTID, which will screw up
* backref code.
*/
cur_inum = st.st_ino + BTRFS_FIRST_FREE_OBJECTID;
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_msg(ERROR_MSG_MEMORY, NULL);
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);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
errno = -ret;
error_msg(ERROR_MSG_START_TRANS, "%m");
goto fail;
}
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) {
errno = -ret;
error_msg(ERROR_MSG_COMMIT_TRANS, "%m");
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);
if (ret == 0) {
error("DEV_EXTENT for devid %llu not found", devid);
ret = -EUCLEAN;
goto out;
}
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_msg(ERROR_MSG_START_TRANS, "%m");
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_msg(ERROR_MSG_COMMIT_TRANS, "%m");
}
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;
}
if (!IS_ALIGNED(new_size, fs_info->sectorsize)) {
error("shrunk filesystem size %llu not aligned to %u",
new_size, fs_info->sectorsize);
return -EUCLEAN;
}
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;
}