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btrfs-progs/convert/main.c

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
/*
* Btrfs convert design:
*
* The overall design of btrfs convert is like the following:
*
* |<------------------Old fs----------------------------->|
* |<- used ->| |<- used ->| |<- used ->|
* ||
* \/
* |<---------------Btrfs fs------------------------------>|
* |<- Old data chunk ->|< new chunk (D/M/S)>|<- ODC ->|
* |<-Old-FE->| |<-Old-FE->|<- Btrfs extents ->|<-Old-FE->|
*
* ODC = Old data chunk, btrfs chunks containing old fs data
* Mapped 1:1 (logical address == device offset)
* Old-FE = file extents pointing to old fs.
*
* So old fs used space is (mostly) kept as is, while btrfs will insert
* its chunk (Data/Meta/Sys) into large enough free space.
* In this way, we can create different profiles for metadata/data for
* converted fs.
*
* We must reserve and relocate 3 ranges for btrfs:
* * [0, 1M) - area never used for any data except the first
* superblock
* * [btrfs_sb_offset(1), +64K) - 1st superblock backup copy
* * [btrfs_sb_offset(2), +64K) - 2nd, dtto
*
* Most work is spent handling corner cases around these reserved ranges.
*
* Detailed workflow is:
* 1) Scan old fs used space and calculate data chunk layout
* 1.1) Scan old fs
* We can a map used space of old fs
*
* 1.2) Calculate data chunk layout - this is the hard part
* New data chunks must meet 3 conditions using result from 1.1
* a. Large enough to be a chunk
* b. Doesn't intersect reserved ranges
* c. Covers all the remaining old fs used space
*
* NOTE: This can be simplified if we don't need to handle backup supers
*
* 1.3) Calculate usable space for new btrfs chunks
* Btrfs chunk usable space must meet 3 conditions using result from 1.2
* a. Large enough to be a chunk
* b. Doesn't intersect reserved ranges
* c. Doesn't cover any data chunks in 1.1
*
* 2) Create basic btrfs filesystem structure
* Initial metadata and sys chunks are inserted in the first available
* space found in step 1.3
* Then insert all data chunks into the basic btrfs
*
* 3) Create convert image
* We need to relocate reserved ranges here.
* After this step, the convert image is done, and we can use the image
* as reflink source to create old files
*
* 4) Iterate old fs to create files
* We just reflink file extents from old fs to newly created files on
* btrfs.
*/
#include "kerncompat.h"
#include <sys/stat.h>
#include <linux/fs.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <getopt.h>
#include <pthread.h>
#include <stdbool.h>
#include <errno.h>
#include <limits.h>
#include <string.h>
#include <uuid/uuid.h>
#include "kernel-lib/sizes.h"
#include "kernel-shared/accessors.h"
#include "kernel-shared/uapi/btrfs_tree.h"
#include "kernel-shared/extent_io.h"
#include "kernel-shared/ctree.h"
#include "kernel-shared/disk-io.h"
#include "kernel-shared/volumes.h"
#include "kernel-shared/transaction.h"
#include "kernel-shared/free-space-tree.h"
#include "kernel-shared/file-item.h"
#include "crypto/hash.h"
#include "common/defs.h"
#include "common/extent-cache.h"
#include "common/internal.h"
#include "common/cpu-utils.h"
#include "common/messages.h"
#include "common/task-utils.h"
#include "common/path-utils.h"
#include "common/help.h"
#include "common/parse-utils.h"
#include "common/string-utils.h"
#include "common/fsfeatures.h"
#include "common/device-scan.h"
#include "common/box.h"
#include "common/open-utils.h"
#include "common/extent-tree-utils.h"
#include "common/root-tree-utils.h"
#include "common/clear-cache.h"
#include "cmds/commands.h"
#include "check/repair.h"
#include "mkfs/common.h"
#include "convert/common.h"
#include "convert/source-fs.h"
extern const struct btrfs_convert_operations ext2_convert_ops;
extern const struct btrfs_convert_operations reiserfs_convert_ops;
static const struct btrfs_convert_operations *convert_operations[] = {
#if BTRFSCONVERT_EXT2
&ext2_convert_ops,
#endif
#if BTRFSCONVERT_REISERFS
&reiserfs_convert_ops,
#endif
};
static void *print_copied_inodes(void *p)
{
struct task_ctx *priv = p;
const char work_indicator[] = { '.', 'o', 'O', 'o' };
u64 count = 0;
task_period_start(priv->info, 1000 /* 1s */);
while (1) {
count++;
pthread_mutex_lock(&priv->mutex);
printf("Copy inodes [%c] [%10llu/%10llu]\r",
work_indicator[count % 4],
priv->cur_copy_inodes, priv->max_copy_inodes);
pthread_mutex_unlock(&priv->mutex);
fflush(stdout);
task_period_wait(priv->info);
}
return NULL;
}
static int after_copied_inodes(void *p)
{
printf("\n");
fflush(stdout);
return 0;
}
static inline int copy_inodes(struct btrfs_convert_context *cctx,
struct btrfs_root *root, u32 convert_flags,
struct task_ctx *p)
{
return cctx->convert_ops->copy_inodes(cctx, root, convert_flags, p);
}
static inline void convert_close_fs(struct btrfs_convert_context *cctx)
{
cctx->convert_ops->close_fs(cctx);
}
static inline int convert_check_state(struct btrfs_convert_context *cctx)
{
return cctx->convert_ops->check_state(cctx);
}
static int csum_disk_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 disk_bytenr, u64 num_bytes)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
u32 blocksize = fs_info->sectorsize;
u64 offset;
char *buffer;
int ret = 0;
buffer = malloc(blocksize);
if (!buffer)
return -ENOMEM;
for (offset = 0; offset < num_bytes; offset += blocksize) {
u64 read_len = blocksize;
ret = read_data_from_disk(fs_info, buffer,
disk_bytenr + offset, &read_len, 0);
if (ret)
break;
if (read_len == 0) {
error("failed to read logical bytenr %llu",
disk_bytenr + offset);
ret = -EIO;
break;
}
ret = btrfs_csum_file_block(trans, disk_bytenr + offset,
BTRFS_EXTENT_CSUM_OBJECTID,
fs_info->csum_type, buffer);
if (ret)
break;
}
free(buffer);
return ret;
}
static int create_image_file_range(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct cache_tree *used,
struct btrfs_inode_item *inode,
u64 ino, u64 bytenr, u64 *ret_len,
u32 convert_flags)
{
struct cache_extent *cache;
struct btrfs_block_group *bg_cache;
const struct simple_range *reserved;
u64 len = *ret_len;
u64 disk_bytenr;
int ret;
u32 datacsum = convert_flags & CONVERT_FLAG_DATACSUM;
if (bytenr != round_down(bytenr, root->fs_info->sectorsize)) {
error("bytenr not sectorsize aligned: %llu", bytenr);
return -EINVAL;
}
if (len != round_down(len, root->fs_info->sectorsize)) {
error("length not sectorsize aligned: %llu", len);
return -EINVAL;
}
len = min_t(u64, len, BTRFS_MAX_EXTENT_SIZE);
/*
* Skip reserved ranges first
*
* Or we will insert a hole into current image file, and later
* migrate block will fail as there is already a file extent.
*/
reserved = intersect_with_reserved(bytenr, len);
if (reserved) {
/*
* |-- reserved --|
* |-- range --|
* or
* |---- reserved ----|
* |-- range --|
* Skip to reserved range end
*/
if (bytenr >= reserved->start) {
*ret_len = range_end(reserved) - bytenr;
return 0;
}
/*
* |-- reserved --|
* |-- range --|
* or
* |-- reserved --|
* |------- range -------|
* Leading part may still create a file extent
*/
len = min_t(u64, len, reserved->start - bytenr);
}
/* Check if we are going to insert regular file extent, or hole */
cache = search_cache_extent(used, bytenr);
if (cache) {
if (cache->start <= bytenr) {
/*
* |///////Used///////|
* |<--insert--->|
* bytenr
* Insert one real file extent
*/
len = min_t(u64, len, cache->start + cache->size -
bytenr);
disk_bytenr = bytenr;
} else {
/*
* |//Used//|
* |<-insert-->|
* bytenr
* Insert one hole
*/
len = min(len, cache->start - bytenr);
disk_bytenr = 0;
datacsum = 0;
}
} else {
/*
* |//Used//| |EOF
* |<-insert-->|
* bytenr
* Insert one hole
*/
disk_bytenr = 0;
datacsum = 0;
}
if (disk_bytenr) {
/* Check if the range is in a data block group */
bg_cache = btrfs_lookup_block_group(root->fs_info, bytenr);
if (!bg_cache) {
error("missing data block for bytenr %llu", bytenr);
return -ENOENT;
}
if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_DATA)) {
error(
"data bytenr %llu is covered by non-data block group %llu flags 0x%llu",
bytenr, bg_cache->start, bg_cache->flags);
return -EINVAL;
}
/* The extent should never cross block group boundary */
len = min_t(u64, len, bg_cache->start + bg_cache->length -
bytenr);
}
if (len != round_down(len, root->fs_info->sectorsize)) {
error("remaining length not sectorsize aligned: %llu", len);
return -EINVAL;
}
ret = btrfs_record_file_extent(trans, root, ino, inode, bytenr,
disk_bytenr, len);
if (ret < 0)
return ret;
if (datacsum) {
ret = csum_disk_extent(trans, root, bytenr, len);
if (ret < 0) {
errno = -ret;
error(
"failed to calculate csum for bytenr %llu len %llu: %m",
bytenr, len);
}
}
*ret_len = len;
return ret;
}
/*
* Relocate old fs data in one reserved ranges
*
* Since all old fs data in reserved range is not covered by any chunk nor
* data extent, we don't need to handle any reference but add new
* extent/reference, which makes codes more clear
*/
static int migrate_one_reserved_range(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct cache_tree *used,
struct btrfs_inode_item *inode, int fd,
u64 ino, const struct simple_range *range,
u32 convert_flags)
{
u64 cur_off = range->start;
u64 cur_len = range->len;
u64 hole_start = range->start;
u64 hole_len;
struct cache_extent *cache;
struct btrfs_key key;
int ret = 0;
/*
* It's possible that there are holes in reserved range:
* |<---------------- Reserved range ---------------------->|
* |<- Old fs data ->| |<- Old fs data ->|
* So here we need to iterate through old fs used space and only
* migrate ranges that covered by old fs data.
*/
while (cur_off < range_end(range)) {
void *buf;
cache = search_cache_extent(used, cur_off);
if (!cache)
break;
cur_off = max(cache->start, cur_off);
if (cur_off >= range_end(range))
break;
cur_len = min(cache->start + cache->size, range_end(range)) -
cur_off;
if (cur_len < root->fs_info->sectorsize) {
error("reserved range cannot be migrated: length %llu < sectorsize %u",
cur_len, root->fs_info->sectorsize);
ret = -EUCLEAN;
break;
}
/* reserve extent for the data */
ret = btrfs_reserve_extent(trans, root, cur_len, 0, 0, (u64)-1,
&key, 1);
if (ret < 0)
break;
buf = malloc(cur_len);
if (!buf) {
ret = -ENOMEM;
break;
}
ret = pread(fd, buf, cur_len, cur_off);
if (ret < cur_len) {
ret = (ret < 0 ? ret : -EIO);
free(buf);
break;
}
ret = write_data_to_disk(root->fs_info, buf, key.objectid, key.offset);
free(buf);
if (ret < 0)
break;
/* Now handle extent item and file extent things */
ret = btrfs_record_file_extent(trans, root, ino, inode, cur_off,
key.objectid, key.offset);
if (ret < 0)
break;
/* Finally, insert csum items */
if (convert_flags & CONVERT_FLAG_DATACSUM)
ret = csum_disk_extent(trans, root, key.objectid,
key.offset);
/* Don't forget to insert hole */
hole_len = cur_off - hole_start;
if (hole_len) {
ret = btrfs_record_file_extent(trans, root, ino, inode,
hole_start, 0, hole_len);
if (ret < 0)
break;
}
cur_off += key.offset;
hole_start = cur_off;
cur_len = range_end(range) - cur_off;
}
/*
* Last hole
* |<---- reserved -------->|
* |<- Old fs data ->| |
* | Hole |
*/
if (range_end(range) - hole_start > 0)
ret = btrfs_record_file_extent(trans, root, ino, inode,
hole_start, 0, range_end(range) - hole_start);
return ret;
}
/*
* Relocate the used source fs data in reserved ranges
*/
static int migrate_reserved_ranges(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct cache_tree *used,
struct btrfs_inode_item *inode, int fd,
u64 ino, u64 total_bytes, u32 convert_flags)
{
int i;
int ret = 0;
for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
const struct simple_range *range = &btrfs_reserved_ranges[i];
if (range->start > total_bytes)
return ret;
ret = migrate_one_reserved_range(trans, root, used, inode, fd,
ino, range, convert_flags);
if (ret < 0)
return ret;
}
return ret;
}
/*
* Helper for expand and merge extent_cache for wipe_one_reserved_range() to
* handle wiping a range that exists in cache.
*/
static int _expand_extent_cache(struct cache_tree *tree,
struct cache_extent *entry,
u64 min_stripe_size, int backward)
{
struct cache_extent *ce;
int diff;
if (entry->size >= min_stripe_size)
return 0;
diff = min_stripe_size - entry->size;
if (backward) {
ce = prev_cache_extent(entry);
if (!ce)
goto expand_back;
if (ce->start + ce->size >= entry->start - diff) {
/* Directly merge with previous extent */
ce->size = entry->start + entry->size - ce->start;
remove_cache_extent(tree, entry);
free(entry);
return 0;
}
expand_back:
/* No overlap, normal extent */
if (entry->start < diff) {
error("cannot find space for data chunk layout");
return -ENOSPC;
}
entry->start -= diff;
entry->size += diff;
return 0;
}
ce = next_cache_extent(entry);
if (!ce)
goto expand_after;
if (entry->start + entry->size + diff >= ce->start) {
/* Directly merge with next extent */
entry->size = ce->start + ce->size - entry->start;
remove_cache_extent(tree, ce);
free(ce);
return 0;
}
expand_after:
entry->size += diff;
return 0;
}
/*
* Remove one reserve range from given cache tree
* if min_stripe_size is non-zero, it will ensure for split case,
* all its split cache extent is no smaller than @min_strip_size / 2.
*/
static int wipe_one_reserved_range(struct cache_tree *tree,
u64 start, u64 len, u64 min_stripe_size,
int ensure_size)
{
struct cache_extent *cache;
int ret;
BUG_ON(ensure_size && min_stripe_size == 0);
/*
* The logical here is simplified to handle special cases only
* So we don't need to consider merge case for ensure_size
*/
BUG_ON(min_stripe_size && (min_stripe_size < len * 2 ||
min_stripe_size / 2 < BTRFS_STRIPE_LEN));
/* Also, wipe range should already be aligned */
BUG_ON(start != round_down(start, BTRFS_STRIPE_LEN) ||
start + len != round_up(start + len, BTRFS_STRIPE_LEN));
min_stripe_size /= 2;
cache = lookup_cache_extent(tree, start, len);
if (!cache)
return 0;
if (start <= cache->start) {
/*
* |--------cache---------|
* |-wipe-|
*/
BUG_ON(start + len <= cache->start);
/*
* The wipe size is smaller than min_stripe_size / 2,
* so the result length should still meet min_stripe_size
* And no need to do alignment
*/
cache->size -= (start + len - cache->start);
if (cache->size == 0) {
remove_cache_extent(tree, cache);
free(cache);
return 0;
}
BUG_ON(ensure_size && cache->size < min_stripe_size);
cache->start = start + len;
return 0;
} else if (start > cache->start && start + len < cache->start +
cache->size) {
/*
* |-------cache-----|
* |-wipe-|
*/
u64 old_start = cache->start;
u64 old_len = cache->size;
u64 insert_start = start + len;
u64 insert_len;
cache->size = start - cache->start;
/* Expand the leading half part if needed */
if (ensure_size && cache->size < min_stripe_size) {
ret = _expand_extent_cache(tree, cache,
min_stripe_size, 1);
if (ret < 0)
return ret;
}
/* And insert the new one */
insert_len = old_start + old_len - start - len;
ret = add_merge_cache_extent(tree, insert_start, insert_len);
if (ret < 0)
return ret;
/* Expand the last half part if needed */
if (ensure_size && insert_len < min_stripe_size) {
cache = lookup_cache_extent(tree, insert_start,
insert_len);
if (!cache || cache->start != insert_start ||
cache->size != insert_len)
return -ENOENT;
ret = _expand_extent_cache(tree, cache,
min_stripe_size, 0);
}
return ret;
}
/*
* |----cache-----|
* |--wipe-|
* Wipe len should be small enough and no need to expand the
* remaining extent
*/
cache->size = start - cache->start;
BUG_ON(ensure_size && cache->size < min_stripe_size);
return 0;
}
/*
* Remove reserved ranges from given cache_tree
*
* It will remove the following ranges
* 1) 0~1M
* 2) 2nd superblock, +64K (make sure chunks are 64K aligned)
* 3) 3rd superblock, +64K
*
* @min_stripe must be given for safety check
* and if @ensure_size is given, it will ensure affected cache_extent will be
* larger than min_stripe_size
*/
static int wipe_reserved_ranges(struct cache_tree *tree, u64 min_stripe_size,
int ensure_size)
{
int i;
int ret;
for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
const struct simple_range *range = &btrfs_reserved_ranges[i];
ret = wipe_one_reserved_range(tree, range->start, range->len,
min_stripe_size, ensure_size);
if (ret < 0)
return ret;
}
return ret;
}
static int calculate_available_space(struct btrfs_convert_context *cctx)
{
struct cache_tree *used = &cctx->used_space;
struct cache_tree *data_chunks = &cctx->data_chunks;
struct cache_tree *free = &cctx->free_space;
struct cache_extent *cache;
u64 cur_off = 0;
/*
* Twice the minimal chunk size, to allow later wipe_reserved_ranges()
* works without need to consider overlap
*/
u64 min_stripe_size = SZ_32M;
int ret;
/* Calculate data_chunks */
for (cache = first_cache_extent(used); cache;
cache = next_cache_extent(cache)) {
u64 cur_len;
if (cache->start + cache->size < cur_off)
continue;
if (cache->start > cur_off + min_stripe_size)
cur_off = cache->start;
cur_len = max(cache->start + cache->size - cur_off,
min_stripe_size);
/* data chunks should never exceed device boundary */
cur_len = min(cctx->total_bytes - cur_off, cur_len);
ret = add_merge_cache_extent(data_chunks, cur_off, cur_len);
if (ret < 0)
goto out;
cur_off += cur_len;
}
/*
* remove reserved ranges, so we won't ever bother relocating an old
* filesystem extent to other place.
*/
ret = wipe_reserved_ranges(data_chunks, min_stripe_size, 1);
if (ret < 0)
goto out;
cur_off = 0;
/*
* Calculate free space
* Always round up the start bytenr, to avoid metadata extent cross
* stripe boundary, as later mkfs_convert() won't have all the extent
* allocation check
*/
for (cache = first_cache_extent(data_chunks); cache;
cache = next_cache_extent(cache)) {
if (cache->start < cur_off)
continue;
if (cache->start > cur_off) {
u64 insert_start;
u64 len;
len = cache->start - round_up(cur_off,
BTRFS_STRIPE_LEN);
insert_start = round_up(cur_off, BTRFS_STRIPE_LEN);
ret = add_merge_cache_extent(free, insert_start, len);
if (ret < 0)
goto out;
}
cur_off = cache->start + cache->size;
}
/* Don't forget the last range */
if (cctx->total_bytes > cur_off) {
u64 len = cctx->total_bytes - cur_off;
u64 insert_start;
insert_start = round_up(cur_off, BTRFS_STRIPE_LEN);
ret = add_merge_cache_extent(free, insert_start, len);
if (ret < 0)
goto out;
}
/* Remove reserved bytes */
ret = wipe_reserved_ranges(free, min_stripe_size, 0);
out:
return ret;
}
static int copy_free_space_tree(struct btrfs_convert_context *cctx)
{
struct cache_tree *src = &cctx->free_space;
struct cache_tree *dst = &cctx->free_space_initial;
struct cache_extent *cache;
int ret = 0;
for (cache = search_cache_extent(src, 0);
cache;
cache = next_cache_extent(cache)) {
ret = add_merge_cache_extent(dst, cache->start, cache->size);
if (ret < 0)
return ret;
cctx->free_bytes_initial += cache->size;
}
return ret;
}
/*
* Read used space, and since we have the used space,
* calculate data_chunks and free for later mkfs
*/
static int convert_read_used_space(struct btrfs_convert_context *cctx)
{
int ret;
ret = cctx->convert_ops->read_used_space(cctx);
if (ret)
return ret;
ret = calculate_available_space(cctx);
if (ret < 0)
return ret;
return copy_free_space_tree(cctx);
}
/*
* Create the fs image file of old filesystem.
*
* This is completely fs independent as we have cctx->used, only
* need to create file extents pointing to all the positions.
*/
static int create_image(struct btrfs_root *root,
struct btrfs_mkfs_config *cfg,
struct btrfs_convert_context *cctx, int fd,
u64 size, char *name, u32 convert_flags)
{
struct btrfs_inode_item buf;
struct btrfs_trans_handle *trans;
struct btrfs_path path = { 0 };
struct btrfs_key key;
struct cache_extent *cache;
struct cache_tree used_tmp;
u64 cur;
u64 ino;
u64 flags = BTRFS_INODE_READONLY;
int ret;
if (!(convert_flags & CONVERT_FLAG_DATACSUM))
flags |= BTRFS_INODE_NODATASUM;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
cache_tree_init(&used_tmp);
ret = btrfs_find_free_objectid(trans, root, BTRFS_FIRST_FREE_OBJECTID,
&ino);
if (ret < 0) {
errno = -ret;
error("failed to find free objectid for root %llu: %m",
root->root_key.objectid);
goto out;
}
ret = btrfs_new_inode(trans, root, ino, 0400 | S_IFREG);
if (ret < 0) {
errno = -ret;
error("failed to create new inode for root %llu: %m",
root->root_key.objectid);
goto out;
}
ret = btrfs_change_inode_flags(trans, root, ino, flags);
if (ret < 0) {
errno = -ret;
error("failed to change inode flag for ino %llu root %llu: %m",
ino, root->root_key.objectid);
goto out;
}
ret = btrfs_add_link(trans, root, ino, BTRFS_FIRST_FREE_OBJECTID, name,
strlen(name), BTRFS_FT_REG_FILE, NULL, 1, 0);
if (ret < 0) {
errno = -ret;
error("failed to link ino %llu to '/%s' in root %llu: %m",
ino, name, root->root_key.objectid);
goto out;
}
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, &path, 0, 1);
if (ret) {
ret = (ret > 0 ? -ENOENT : ret);
goto out;
}
read_extent_buffer(path.nodes[0], &buf,
btrfs_item_ptr_offset(path.nodes[0], path.slots[0]),
sizeof(buf));
btrfs_release_path(&path);
/*
* Create a new used space cache, which doesn't contain the reserved
* range
*/
for (cache = first_cache_extent(&cctx->used_space); cache;
cache = next_cache_extent(cache)) {
ret = add_cache_extent(&used_tmp, cache->start, cache->size);
if (ret < 0)
goto out;
}
ret = wipe_reserved_ranges(&used_tmp, 0, 0);
if (ret < 0)
goto out;
/*
* Start from 1M, as 0~1M is reserved, and create_image_file_range()
* can't handle bytenr 0(will consider it as a hole)
*/
cur = SZ_1M;
while (cur < size) {
u64 len = size - cur;
ret = create_image_file_range(trans, root, &used_tmp,
&buf, ino, cur, &len,
convert_flags);
if (ret < 0)
goto out;
cur += len;
}
/* Handle the reserved ranges */
ret = migrate_reserved_ranges(trans, root, &cctx->used_space, &buf, fd,
ino, cfg->num_bytes, convert_flags);
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, &path, 0, 1);
if (ret) {
ret = (ret > 0 ? -ENOENT : ret);
goto out;
}
btrfs_set_stack_inode_size(&buf, cfg->num_bytes);
write_extent_buffer(path.nodes[0], &buf,
btrfs_item_ptr_offset(path.nodes[0], path.slots[0]),
sizeof(buf));
out:
free_extent_cache_tree(&used_tmp);
btrfs_release_path(&path);
btrfs_commit_transaction(trans, root);
return ret;
}
/*
* New make_btrfs() has handle system and meta chunks quite well.
* So only need to add remaining data chunks.
*/
static int make_convert_data_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_mkfs_config *cfg,
struct btrfs_convert_context *cctx)
{
struct cache_tree *data_chunks = &cctx->data_chunks;
struct cache_extent *cache;
u64 max_chunk_size;
int ret = 0;
/*
* Don't create data chunk over 10% of the convert device
* And for single chunk, don't create chunk larger than 1G.
*/
max_chunk_size = cfg->num_bytes / 10;
max_chunk_size = min((u64)(SZ_1G), max_chunk_size);
max_chunk_size = round_down(max_chunk_size, fs_info->sectorsize);
for (cache = first_cache_extent(data_chunks); cache;
cache = next_cache_extent(cache)) {
u64 cur = cache->start;
while (cur < cache->start + cache->size) {
u64 len;
u64 cur_backup = cur;
len = min(max_chunk_size,
round_up(cache->start + cache->size,
BTRFS_STRIPE_LEN) - cur);
ret = btrfs_alloc_data_chunk(trans, fs_info, &cur_backup, len);
if (ret < 0)
break;
ret = btrfs_make_block_group(trans, fs_info, 0,
BTRFS_BLOCK_GROUP_DATA, cur, len);
if (ret < 0)
break;
cur += len;
}
}
return ret;
}
/*
* Init the temp btrfs to a operational status.
*
* It will fix the extent usage accounting(XXX: Do we really need?) and
* insert needed data chunks, to ensure all old fs data extents are covered
* by DATA chunks, preventing wrong chunks are allocated.
*
* And also create convert image subvolume and relocation tree.
* (XXX: Not need again?)
* But the convert image subvolume is *NOT* linked to fs tree yet.
*/
static int init_btrfs(struct btrfs_mkfs_config *cfg, struct btrfs_root *root,
struct btrfs_convert_context *cctx, u32 convert_flags)
{
struct btrfs_key location;
struct btrfs_trans_handle *trans;
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
/*
* Don't alloc any metadata/system chunk, as we don't want
* any meta/sys chunk allocated before all data chunks are inserted.
* Or we screw up the chunk layout just like the old implement.
*/
fs_info->avoid_sys_chunk_alloc = 1;
fs_info->avoid_meta_chunk_alloc = 1;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
errno = -ret;
error_msg(ERROR_MSG_START_TRANS, "%m");
goto err;
}
ret = btrfs_fix_block_accounting(trans);
if (ret)
goto err;
ret = make_convert_data_block_groups(trans, fs_info, cfg, cctx);
if (ret)
goto err;
ret = btrfs_make_root_dir(trans, fs_info->tree_root,
BTRFS_ROOT_TREE_DIR_OBJECTID);
if (ret)
goto err;
memcpy(&location, &root->root_key, sizeof(location));
location.offset = (u64)-1;
ret = btrfs_insert_dir_item(trans, fs_info->tree_root, "default", 7,
btrfs_super_root_dir(fs_info->super_copy),
&location, BTRFS_FT_DIR, 0);
if (ret)
goto err;
ret = btrfs_insert_inode_ref(trans, fs_info->tree_root, "default", 7,
location.objectid,
btrfs_super_root_dir(fs_info->super_copy), 0);
if (ret)
goto err;
btrfs_set_root_dirid(&fs_info->fs_root->root_item,
BTRFS_FIRST_FREE_OBJECTID);
/* subvol for fs image file */
ret = btrfs_make_subvolume(trans, CONV_IMAGE_SUBVOL_OBJECTID);
if (ret < 0) {
error("failed to create subvolume image root: %d", ret);
goto err;
}
/* subvol for data relocation tree */
ret = btrfs_make_subvolume(trans, BTRFS_DATA_RELOC_TREE_OBJECTID);
if (ret < 0) {
error("failed to create DATA_RELOC root: %d", ret);
goto err;
}
ret = btrfs_commit_transaction(trans, root);
fs_info->avoid_sys_chunk_alloc = 0;
fs_info->avoid_meta_chunk_alloc = 0;
err:
return ret;
}
/*
* Migrate super block to its default position and zero 0 ~ 16k
*/
static int migrate_super_block(int fd, u64 old_bytenr)
{
int ret;
struct btrfs_super_block super;
u8 result[BTRFS_CSUM_SIZE] = {};
u32 len;
u32 bytenr;
ret = pread(fd, &super, BTRFS_SUPER_INFO_SIZE, old_bytenr);
if (ret != BTRFS_SUPER_INFO_SIZE)
goto fail;
BUG_ON(btrfs_super_bytenr(&super) != old_bytenr);
btrfs_set_super_bytenr(&super, BTRFS_SUPER_INFO_OFFSET);
btrfs_csum_data(NULL, btrfs_super_csum_type(&super),
(u8 *)&super + BTRFS_CSUM_SIZE, result,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
memcpy(&super.csum[0], result, BTRFS_CSUM_SIZE);
ret = pwrite(fd, &super , BTRFS_SUPER_INFO_SIZE,
BTRFS_SUPER_INFO_OFFSET);
if (ret != BTRFS_SUPER_INFO_SIZE)
goto fail;
ret = fsync(fd);
if (ret)
goto fail;
memset(&super, 0, BTRFS_SUPER_INFO_SIZE);
for (bytenr = 0; bytenr < BTRFS_SUPER_INFO_OFFSET; ) {
len = BTRFS_SUPER_INFO_OFFSET - bytenr;
if (len > BTRFS_SUPER_INFO_SIZE)
len = BTRFS_SUPER_INFO_SIZE;
ret = pwrite(fd, &super, len, bytenr);
if (ret != len) {
error("unable to zero fill device");
break;
}
bytenr += len;
}
ret = 0;
fsync(fd);
fail:
if (ret > 0)
ret = -1;
return ret;
}
static int convert_open_fs(const char *devname,
struct btrfs_convert_context *cctx)
{
int i;
for (i = 0; i < ARRAY_SIZE(convert_operations); i++) {
int ret = convert_operations[i]->open_fs(cctx, devname);
if (ret == 0) {
cctx->convert_ops = convert_operations[i];
return ret;
}
}
error("no file system found to convert");
return -1;
}
static int link_image_subvolume(struct btrfs_root *image_root, char *name)
{
struct btrfs_fs_info *fs_info = image_root->fs_info;
struct btrfs_root *fs_root = fs_info->fs_root;
struct btrfs_trans_handle *trans;
char buf[BTRFS_NAME_LEN + 1]; /* for snprintf, null terminated. */
int ret;
/*
* 1 root backref 1 root forward ref, 1 dir item 1 dir index,
* and finally one root item.
*/
trans = btrfs_start_transaction(fs_root, 5);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
errno = -ret;
error("failed to start transaction to link subvolume: %m");
return PTR_ERR(trans);
}
ret = btrfs_link_subvolume(trans, fs_root, btrfs_root_dirid(&fs_root->root_item),
name, strlen(name), image_root);
/* No filename conflicts, all done. */
if (!ret)
goto commit;
/* Other unexpected errors. */
if (ret != -EEXIST) {
btrfs_abort_transaction(trans, ret);
return ret;
}
/* Filename conflicts detected, try different names. */
for (int i = 0; i < 1024; i++) {
int len;
len = snprintf(buf, ARRAY_SIZE(buf), "%s%d", name, i);
if (len == 0 || len > BTRFS_NAME_LEN) {
error("failed to find an alternative name for image_root");
ret = -EINVAL;
goto abort;
}
ret = btrfs_link_subvolume(trans, fs_root,
btrfs_root_dirid(&fs_root->root_item),
buf, len, image_root);
if (!ret)
break;
if (ret != -EEXIST)
goto abort;
}
commit:
ret = btrfs_commit_transaction(trans, fs_info->tree_root);
return ret;
abort:
btrfs_abort_transaction(trans, ret);
return ret;
}
static int do_convert(const char *devname, u32 convert_flags, u32 nodesize,
const char *fslabel, int progress,
struct btrfs_mkfs_features *features, u16 csum_type,
char fsid[BTRFS_UUID_UNPARSED_SIZE])
{
int ret;
int fd = -1;
u32 blocksize;
struct btrfs_root *root;
struct btrfs_root *image_root;
struct btrfs_convert_context cctx;
struct btrfs_key key;
char subvol_name[SOURCE_FS_NAME_LEN + 8];
struct task_ctx ctx;
char features_buf[BTRFS_FEATURE_STRING_BUF_SIZE];
char fsid_str[BTRFS_UUID_UNPARSED_SIZE];
struct btrfs_mkfs_config mkfs_cfg;
bool btrfs_sb_committed = false;
memset(&mkfs_cfg, 0, sizeof(mkfs_cfg));
init_convert_context(&cctx);
ret = convert_open_fs(devname, &cctx);
if (ret)
goto fail;
ret = convert_check_state(&cctx);
if (ret)
warning(
"source filesystem is not clean, running filesystem check is recommended");
ret = convert_read_used_space(&cctx);
if (ret)
goto fail;
UASSERT(cctx.total_bytes != 0);
blocksize = cctx.blocksize;
if (blocksize < 4096) {
error("block size is too small: %u < 4096", blocksize);
goto fail;
}
if (blocksize != getpagesize())
warning(
"blocksize %u is not equal to the page size %u, converted filesystem won't mount on this system",
blocksize, getpagesize());
if (btrfs_check_nodesize(nodesize, blocksize, features))
goto fail;
fd = open(devname, O_RDWR);
if (fd < 0) {
error("unable to open %s: %m", devname);
goto fail;
}
btrfs_parse_fs_features_to_string(features_buf, features);
if (!memcmp(features, &btrfs_mkfs_default_features,
sizeof(struct btrfs_mkfs_features)))
strcat(features_buf, " (default)");
if (convert_flags & CONVERT_FLAG_COPY_FSID) {
uuid_unparse(cctx.fs_uuid, mkfs_cfg.fs_uuid);
if (!test_uuid_unique(mkfs_cfg.fs_uuid))
warning("non-unique UUID (copy): %s", mkfs_cfg.fs_uuid);
} else if (fsid[0] == 0) {
uuid_t uuid;
uuid_generate(uuid);
uuid_unparse(uuid, mkfs_cfg.fs_uuid);
} else {
memcpy(mkfs_cfg.fs_uuid, fsid, BTRFS_UUID_UNPARSED_SIZE);
if (!test_uuid_unique(mkfs_cfg.fs_uuid))
warning("non-unique UUID (user set): %s", mkfs_cfg.fs_uuid);
}
printf("Source filesystem:\n");
printf(" Type: %s\n", cctx.convert_ops->name);
printf(" Label: %s\n", cctx.label);
printf(" Blocksize: %u\n", blocksize);
uuid_unparse(cctx.fs_uuid, fsid_str);
printf(" UUID: %s\n", fsid_str);
printf("Target filesystem:\n");
printf(" Label: %s\n", fslabel);
printf(" Blocksize: %u\n", blocksize);
printf(" Nodesize: %u\n", nodesize);
printf(" UUID: %s\n", mkfs_cfg.fs_uuid);
printf(" Checksum: %s\n", btrfs_super_csum_name(csum_type));
printf(" Features: %s\n", features_buf);
printf(" Data csum: %s\n", (convert_flags & CONVERT_FLAG_DATACSUM) ? "yes" : "no");
printf(" Inline data: %s\n", (convert_flags & CONVERT_FLAG_INLINE_DATA) ? "yes" : "no");
printf(" Copy xattr: %s\n", (convert_flags & CONVERT_FLAG_XATTR) ? "yes" : "no");
printf("Reported stats:\n");
printf(" Total space: %12llu\n", cctx.total_bytes);
printf(" Free space: %12llu (%.2f%%)\n", cctx.free_bytes_initial,
100.0 * cctx.free_bytes_initial / cctx.total_bytes);
printf(" Inode count: %12llu\n", cctx.inodes_count);
printf(" Free inodes: %12llu\n", cctx.free_inodes_count);
printf(" Block count: %12llu\n", cctx.block_count);
mkfs_cfg.csum_type = csum_type;
mkfs_cfg.label = cctx.label;
mkfs_cfg.num_bytes = cctx.total_bytes;
mkfs_cfg.nodesize = nodesize;
mkfs_cfg.sectorsize = blocksize;
mkfs_cfg.stripesize = blocksize;
memcpy(&mkfs_cfg.features, features, sizeof(struct btrfs_mkfs_features));
mkfs_cfg.leaf_data_size = __BTRFS_LEAF_DATA_SIZE(nodesize);
printf("Create initial btrfs filesystem\n");
ret = make_convert_btrfs(fd, &mkfs_cfg, &cctx);
if (ret) {
errno = -ret;
error("unable to create initial ctree: %m");
goto fail;
}
root = open_ctree_fd(fd, devname, mkfs_cfg.super_bytenr,
OPEN_CTREE_WRITES | OPEN_CTREE_TEMPORARY_SUPER);
if (!root) {
error("unable to open ctree");
goto fail;
}
ret = init_btrfs(&mkfs_cfg, root, &cctx, convert_flags);
if (ret) {
error("unable to setup the root tree: %d", ret);
goto fail;
}
printf("Create %s image file\n", cctx.convert_ops->name);
snprintf(subvol_name, sizeof(subvol_name), "%s_saved",
cctx.convert_ops->name);
key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
image_root = btrfs_read_fs_root(root->fs_info, &key);
if (!image_root) {
error("unable to create image subvolume");
goto fail;
}
ret = create_image(image_root, &mkfs_cfg, &cctx, fd,
mkfs_cfg.num_bytes, "image",
convert_flags);
if (ret) {
error("failed to create %s/image: %d", subvol_name, ret);
goto fail;
}
printf("Create btrfs metadata\n");
ret = pthread_mutex_init(&ctx.mutex, NULL);
if (ret) {
error("failed to initialize mutex: %d", ret);
goto fail;
}
ctx.max_copy_inodes = (cctx.inodes_count - cctx.free_inodes_count);
ctx.cur_copy_inodes = 0;
if (progress) {
ctx.info = task_init(print_copied_inodes, after_copied_inodes,
&ctx);
task_start(ctx.info, NULL, NULL);
}
ret = copy_inodes(&cctx, root, convert_flags, &ctx);
if (ret) {
error("error during copy_inodes %d", ret);
goto fail;
}
if (progress) {
task_stop(ctx.info);
task_deinit(ctx.info);
}
ret = link_image_subvolume(image_root, subvol_name);
if (ret < 0) {
errno = -ret;
error("unable to link subvolume %s: %m", subvol_name);
goto fail;
}
memset(root->fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
if (convert_flags & CONVERT_FLAG_COPY_LABEL) {
strncpy_null(root->fs_info->super_copy->label, cctx.label, BTRFS_LABEL_SIZE);
printf("Copy label '%s'\n", root->fs_info->super_copy->label);
} else if (convert_flags & CONVERT_FLAG_SET_LABEL) {
strcpy(root->fs_info->super_copy->label, fslabel);
printf("Set label to '%s'\n", fslabel);
}
ret = close_ctree(root);
if (ret) {
error("close_ctree failed: %d", ret);
goto fail;
}
convert_close_fs(&cctx);
clean_convert_context(&cctx);
/*
* If this step succeed, we get a mountable btrfs. Otherwise
* the source fs is left unchanged.
*/
ret = migrate_super_block(fd, mkfs_cfg.super_bytenr);
if (ret) {
error("unable to migrate super block: %d", ret);
goto fail;
}
btrfs_sb_committed = true;
root = open_ctree_fd(fd, devname, 0,
OPEN_CTREE_WRITES | OPEN_CTREE_TEMPORARY_SUPER);
if (!root) {
error("unable to open ctree for finalization");
goto fail;
}
/*
* Setup free space tree.
*
* - Clear any v1 cache first
* - Create v2 free space tree
*/
if (mkfs_cfg.features.compat_ro_flags & BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE) {
ret = do_clear_free_space_cache(root->fs_info, 1);
if (ret < 0) {
errno = -ret;
error("failed to clear v1 space cache: %m");
goto fail;
}
ret = btrfs_create_free_space_tree(root->fs_info);
if (ret < 0) {
errno = -ret;
error("failed to create v2 space cache: %m");
goto fail;
}
}
root->fs_info->finalize_on_close = 1;
close_ctree(root);
close(fd);
printf("Conversion complete\n");
return 0;
fail:
clean_convert_context(&cctx);
if (fd != -1)
close(fd);
if (btrfs_sb_committed)
warning(
"error during conversion, filesystem is partially created but not finalized and not mountable");
else
warning(
"error during conversion, the original filesystem is not modified");
return -1;
}
/*
* Read out data of convert image which is in btrfs reserved ranges so we can
* use them to overwrite the ranges during rollback.
*/
static int read_reserved_ranges(struct btrfs_root *root, u64 ino,
u64 total_bytes, char *reserved_ranges[])
{
int i;
int ret = 0;
for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
const struct simple_range *range = &btrfs_reserved_ranges[i];
if (range->start + range->len >= total_bytes)
break;
ret = btrfs_read_file(root, ino, range->start, range->len,
reserved_ranges[i]);
if (ret < range->len) {
error(
"failed to read data of convert image, offset=%llu len=%llu ret=%d",
range->start, range->len, ret);
if (ret >= 0)
ret = -EIO;
break;
}
ret = 0;
}
return ret;
}
static bool is_subset_of_reserved_ranges(u64 start, u64 len)
{
int i;
bool ret = false;
for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
const struct simple_range *range = &btrfs_reserved_ranges[i];
if (start >= range->start && start + len <= range_end(range)) {
ret = true;
break;
}
}
return ret;
}
static bool is_chunk_direct_mapped(struct btrfs_fs_info *fs_info, u64 start)
{
struct cache_extent *ce;
struct map_lookup *map;
bool ret = false;
ce = search_cache_extent(&fs_info->mapping_tree.cache_tree, start);
if (!ce)
goto out;
if (ce->start > start || ce->start + ce->size < start)
goto out;
map = container_of(ce, struct map_lookup, ce);
/* Not SINGLE chunk */
if (map->num_stripes != 1)
goto out;
/* Chunk's logical doesn't match with physical, not 1:1 mapped */
if (map->ce.start != map->stripes[0].physical)
goto out;
ret = true;
out:
return ret;
}
/*
* Iterate all file extents of the convert image.
*
* All file extents except ones in btrfs_reserved_ranges must be mapped 1:1
* on disk. (Means their file_offset must match their on disk bytenr)
*
* File extents in reserved ranges can be relocated to other place, and in
* that case we will read them out for later use.
*/
static int check_convert_image(struct btrfs_root *image_root, u64 ino,
u64 total_size, char *reserved_ranges[])
{
struct btrfs_key key;
struct btrfs_path path = { 0 };
struct btrfs_fs_info *fs_info = image_root->fs_info;
u64 checked_bytes = 0;
int ret;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, image_root, &key, &path, 0, 0);
/*
* It's possible that some fs doesn't store any (including sb)
* data into 0~1M range, and NO_HOLES is enabled.
*
* So we only need to check if ret < 0
*/
if (ret < 0) {
errno = -ret;
error("failed to iterate file extents at offset 0: %m");
btrfs_release_path(&path);
return ret;
}
/* Loop from the first file extents */
while (1) {
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf = path.nodes[0];
u64 disk_bytenr;
u64 file_offset;
u64 ram_bytes;
int slot = path.slots[0];
if (slot >= btrfs_header_nritems(leaf))
goto next;
btrfs_item_key_to_cpu(leaf, &key, slot);
/*
* Iteration is done, exit normally, we have extra check out of
* the loop
*/
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
ret = 0;
break;
}
file_offset = key.offset;
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) {
ret = -EINVAL;
error(
"ino %llu offset %llu doesn't have a regular file extent",
ino, file_offset);
break;
}
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi)) {
ret = -EINVAL;
error(
"ino %llu offset %llu doesn't have a plain file extent",
ino, file_offset);
break;
}
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
checked_bytes += ram_bytes;
/* Skip hole */
if (disk_bytenr == 0)
goto next;
/*
* Most file extents must be 1:1 mapped, which means 2 things:
* 1) File extent file offset == disk_bytenr
* 2) That data chunk's logical == chunk's physical
*
* So file extent's file offset == physical position on disk.
*
* And after rolling back btrfs reserved range, other part
* remains what old fs used to be.
*/
if (file_offset != disk_bytenr ||
!is_chunk_direct_mapped(fs_info, disk_bytenr)) {
/*
* Only file extent in btrfs reserved ranges are
* allowed to be non-1:1 mapped
*/
if (!is_subset_of_reserved_ranges(file_offset,
ram_bytes)) {
ret = -EINVAL;
error(
"ino %llu offset %llu file extent should not be relocated",
ino, file_offset);
break;
}
}
next:
ret = btrfs_next_item(image_root, &path);
if (ret) {
if (ret > 0)
ret = 0;
break;
}
}
btrfs_release_path(&path);
if (ret)
return ret;
/*
* For HOLES mode (without NO_HOLES), we must ensure file extents
* cover the whole range of the image
*/
if (!ret && !btrfs_fs_incompat(fs_info, NO_HOLES)) {
if (checked_bytes != total_size) {
ret = -EINVAL;
error("inode %llu has some file extents not checked",
ino);
return ret;
}
}
/* So far so good, read old data located in btrfs reserved ranges */
ret = read_reserved_ranges(image_root, ino, total_size,
reserved_ranges);
return ret;
}
/*
* btrfs rollback is just reverted convert:
* |<---------------Btrfs fs------------------------------>|
* |<- Old data chunk ->|< new chunk (D/M/S)>|<- ODC ->|
* |<-Old-FE->| |<-Old-FE->|<- Btrfs extents ->|<-Old-FE->|
* ||
* \/
* |<------------------Old fs----------------------------->|
* |<- used ->| |<- used ->| |<- used ->|
*
* However things are much easier than convert, we don't really need to
* do the complex space calculation, but only to handle btrfs reserved space
*
* |<---------------------------Btrfs fs----------------------------->|
* | RSV 1 | | Old | | RSV 2 | | Old | | RSV 3 |
* | 0~1M | | Fs | | SB2 + 64K | | Fs | | SB3 + 64K |
*
* On the other hand, the converted fs image in btrfs is a completely
* valid old fs.
*
* |<-----------------Converted fs image in btrfs-------------------->|
* | RSV 1 | | Old | | RSV 2 | | Old | | RSV 3 |
* | Relocated | | Fs | | Relocated | | Fs | | Relocated |
*
* Used space in fs image should be at the same physical position on disk.
* We only need to recover the data in reserved ranges, so the whole
* old fs is back.
*
* The idea to rollback is also straightforward, we just "read" out the data
* of reserved ranges, and write them back to there they should be.
* Then the old fs is back.
*/
static int do_rollback(const char *devname)
{
struct btrfs_root *root;
struct btrfs_root *image_root;
struct btrfs_fs_info *fs_info;
struct btrfs_key key;
struct btrfs_path path = { 0 };
struct btrfs_dir_item *dir;
struct btrfs_inode_item *inode_item;
struct btrfs_root_ref *root_ref_item;
char *image_name = "image";
char dir_name[PATH_MAX];
int name_len;
char fsid_str[BTRFS_UUID_UNPARSED_SIZE];
char *reserved_ranges[ARRAY_SIZE(btrfs_reserved_ranges)] = { NULL };
u64 total_bytes;
u64 fsize;
u64 root_dir;
u64 ino;
int fd = -1;
int ret;
int i;
printf("Open filesystem for rollback:\n");
for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
const struct simple_range *range = &btrfs_reserved_ranges[i];
reserved_ranges[i] = calloc(1, range->len);
if (!reserved_ranges[i]) {
ret = -ENOMEM;
goto free_mem;
}
}
fd = open(devname, O_RDWR);
if (fd < 0) {
error("unable to open %s: %m", devname);
ret = -EIO;
goto free_mem;
}
fsize = lseek(fd, 0, SEEK_END);
/*
* For rollback, we don't really need to write anything so open it
* read-only. The write part will happen after we close the
* filesystem.
*/
root = open_ctree_fd(fd, devname, 0, 0);
if (!root) {
error("unable to open ctree");
ret = -EIO;
goto free_mem;
}
fs_info = root->fs_info;
printf(" Label: %s\n", fs_info->super_copy->label);
uuid_unparse(fs_info->super_copy->fsid, fsid_str);
printf(" UUID: %s\n", fsid_str);
/*
* Search root backref first, or after subvolume deletion (orphan),
* we can still rollback the image.
*/
key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
key.type = BTRFS_ROOT_BACKREF_KEY;
key.offset = BTRFS_FS_TREE_OBJECTID;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, &path, 0, 0);
if (ret > 0) {
error("unable to find source fs image subvolume, is it deleted?");
ret = -ENOENT;
goto close_fs;
} else if (ret < 0) {
errno = -ret;
error("failed to find source fs image subvolume: %m");
goto close_fs;
}
/* (256 ROOT_BACKREF 5) */
/* root backref key dirid 256 sequence 3 name ext2_saved */
root_ref_item = btrfs_item_ptr(path.nodes[0], path.slots[0], struct btrfs_root_ref);
name_len = btrfs_root_ref_name_len(path.nodes[0], root_ref_item);
if (name_len > sizeof(dir_name))
name_len = sizeof(dir_name) - 1;
read_extent_buffer(path.nodes[0], dir_name, (unsigned long)(root_ref_item + 1), name_len);
dir_name[sizeof(dir_name) - 1] = 0;
printf(" Restoring from: %s/%s\n", dir_name, image_name);
btrfs_release_path(&path);
/* Search convert subvolume */
key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
image_root = btrfs_read_fs_root(fs_info, &key);
if (IS_ERR(image_root)) {
ret = PTR_ERR(image_root);
errno = -ret;
error("failed to open convert image subvolume: %m");
goto close_fs;
}
/* Search the image file */
root_dir = btrfs_root_dirid(&image_root->root_item);
dir = btrfs_lookup_dir_item(NULL, image_root, &path, root_dir,
image_name, strlen(image_name), 0);
if (!dir || IS_ERR(dir)) {
btrfs_release_path(&path);
if (dir)
ret = PTR_ERR(dir);
else
ret = -ENOENT;
errno = -ret;
error("failed to locate file %s: %m", image_name);
goto close_fs;
}
btrfs_dir_item_key_to_cpu(path.nodes[0], dir, &key);
btrfs_release_path(&path);
/* Get total size of the original image */
ino = key.objectid;
ret = btrfs_lookup_inode(NULL, image_root, &path, &key, 0);
if (ret < 0) {
btrfs_release_path(&path);
errno = -ret;
error("unable to find inode %llu: %m", ino);
goto close_fs;
}
inode_item = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_inode_item);
total_bytes = btrfs_inode_size(path.nodes[0], inode_item);
btrfs_release_path(&path);
/* Check if we can rollback the image */
ret = check_convert_image(image_root, ino, total_bytes, reserved_ranges);
if (ret < 0) {
error("old fs image can't be rolled back");
goto close_fs;
}
close_fs:
btrfs_release_path(&path);
close_ctree_fs_info(fs_info);
if (ret)
goto free_mem;
/*
* Everything is OK, just write back old fs data into btrfs reserved
* ranges
*
* Here, we starts from the backup blocks first, so if something goes
* wrong, the fs is still mountable
*/
for (i = ARRAY_SIZE(btrfs_reserved_ranges) - 1; i >= 0; i--) {
u64 real_size;
const struct simple_range *range = &btrfs_reserved_ranges[i];
if (range_end(range) >= fsize)
continue;
real_size = min(range_end(range), fsize) - range->start;
ret = pwrite(fd, reserved_ranges[i], real_size, range->start);
if (ret < real_size) {
if (ret < 0)
ret = -errno;
else
ret = -EIO;
errno = -ret;
error("failed to recover range [%llu, %llu): %m",
range->start, real_size);
goto free_mem;
}
ret = 0;
}
free_mem:
for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++)
free(reserved_ranges[i]);
if (ret)
error("rollback failed");
else
printf("Rollback succeeded\n");
return ret;
}
static const char * const convert_usage[] = {
"btrfs-convert [options] device",
"In-place conversion from other filesystems to BTRFS",
"",
"Options:",
OPTLINE("-d|--no-datasum", "disable data checksum, sets NODATASUM"),
OPTLINE("-i|--no-xattr", "ignore xattrs and ACLs"),
OPTLINE("-n|--no-inline", "disable inlining of small files to metadata"),
OPTLINE("--csum TYPE", ""),
OPTLINE("--checksum TYPE", "checksum algorithm to use (default: crc32c)"),
OPTLINE("-N|--nodesize SIZE", "set filesystem metadata nodesize"),
OPTLINE("-r|--rollback", "roll back to the original filesystem"),
OPTLINE("-l|--label LABEL", "set filesystem label"),
OPTLINE("-L|--copy-label", "use label from converted filesystem"),
OPTLINE("--uuid SPEC", "new, copy or user-defined conforming UUID"),
OPTLINE("-p|--progress", "show converting progress (default)"),
OPTLINE("-O|--features LIST", "comma separated list of filesystem features"),
OPTLINE("--no-progress", "show only overview, not the detailed progress"),
"",
"Supported filesystems:",
"\text2/3/4: "
#if BTRFSCONVERT_EXT2
"yes",
#else
"no",
#endif
"\treiserfs: "
#if BTRFSCONVERT_REISERFS
"yes",
#else
"no",
#endif
NULL
};
static const struct cmd_struct convert_cmd = {
.usagestr = convert_usage
};
int BOX_MAIN(convert)(int argc, char *argv[])
{
int ret;
int packing = 1;
int noxattr = 0;
int datacsum = 1;
u32 nodesize = max_t(u32, sysconf(_SC_PAGESIZE),
BTRFS_MKFS_DEFAULT_NODE_SIZE);
int rollback = 0;
int copylabel = 0;
int usage_error = 0;
int progress = 1;
char *file;
char fslabel[BTRFS_LABEL_SIZE] = { 0 };
struct btrfs_mkfs_features features = btrfs_mkfs_default_features;
u16 csum_type = BTRFS_CSUM_TYPE_CRC32;
u32 copy_fsid = 0;
char fsid[BTRFS_UUID_UNPARSED_SIZE] = {0};
cpu_detect_flags();
hash_init_accel();
btrfs_assert_feature_buf_size();
printf("btrfs-convert from %s\n\n", PACKAGE_STRING);
while(1) {
enum { GETOPT_VAL_NO_PROGRESS = GETOPT_VAL_FIRST, GETOPT_VAL_CHECKSUM,
GETOPT_VAL_UUID };
static const struct option long_options[] = {
{ "no-progress", no_argument, NULL,
GETOPT_VAL_NO_PROGRESS },
{ "no-datasum", no_argument, NULL, 'd' },
{ "no-inline", no_argument, NULL, 'n' },
{ "no-xattr", no_argument, NULL, 'i' },
{ "checksum", required_argument, NULL,
GETOPT_VAL_CHECKSUM },
{ "csum", required_argument, NULL,
GETOPT_VAL_CHECKSUM },
{ "rollback", no_argument, NULL, 'r' },
{ "features", required_argument, NULL, 'O' },
{ "progress", no_argument, NULL, 'p' },
{ "label", required_argument, NULL, 'l' },
{ "copy-label", no_argument, NULL, 'L' },
{ "uuid", required_argument, NULL, GETOPT_VAL_UUID },
{ "nodesize", required_argument, NULL, 'N' },
{ "help", no_argument, NULL, GETOPT_VAL_HELP},
{ NULL, 0, NULL, 0 }
};
int c = getopt_long(argc, argv, "dinN:rl:LpO:", long_options, NULL);
if (c < 0)
break;
switch(c) {
case 'd':
datacsum = 0;
break;
case 'i':
noxattr = 1;
break;
case 'n':
packing = 0;
break;
case 'N':
nodesize = arg_strtou64_with_suffix(optarg);
break;
case 'r':
rollback = 1;
break;
case 'l':
copylabel = CONVERT_FLAG_SET_LABEL;
if (strlen(optarg) >= BTRFS_LABEL_SIZE) {
warning(
"label too long, trimmed to %d bytes",
BTRFS_LABEL_SIZE - 1);
}
strncpy_null(fslabel, optarg, BTRFS_LABEL_SIZE);
break;
case 'L':
copylabel = CONVERT_FLAG_COPY_LABEL;
break;
case 'p':
progress = 1;
break;
case 'O': {
char *orig = strdup(optarg);
char *tmp = orig;
tmp = btrfs_parse_fs_features(tmp, &features);
if (tmp) {
error("unrecognized filesystem feature: %s",
tmp);
free(orig);
exit(1);
}
free(orig);
if (features.runtime_flags &
BTRFS_FEATURE_RUNTIME_LIST_ALL) {
btrfs_list_all_fs_features(
&btrfs_convert_allowed_features);
exit(0);
}
if (btrfs_check_features(&features,
&btrfs_convert_allowed_features)) {
char buf[64];
btrfs_parse_fs_features_to_string(buf,
&btrfs_convert_allowed_features);
error("features not allowed for convert: %s",
buf);
exit(1);
}
break;
}
case GETOPT_VAL_NO_PROGRESS:
progress = 0;
break;
case GETOPT_VAL_CHECKSUM:
csum_type = parse_csum_type(optarg);
break;
case GETOPT_VAL_UUID:
copy_fsid = 0;
fsid[0] = 0;
if (strcmp(optarg, "copy") == 0) {
copy_fsid = CONVERT_FLAG_COPY_FSID;
} else if (strcmp(optarg, "new") == 0) {
/* Generated later */
} else {
uuid_t uuid;
if (uuid_parse(optarg, uuid) != 0) {
error("invalid UUID: %s\n", optarg);
return 1;
}
strncpy_null(fsid, optarg, sizeof(fsid));
}
break;
case GETOPT_VAL_HELP:
default:
usage(&convert_cmd, c != GETOPT_VAL_HELP);
}
}
set_argv0(argv);
if (check_argc_exact(argc - optind, 1)) {
usage(&convert_cmd, 1);
return 1;
}
if (rollback && (!datacsum || noxattr || !packing)) {
fprintf(stderr,
"Usage error: -d, -i, -n options do not apply to rollback\n");
usage_error++;
}
if (usage_error) {
usage(&convert_cmd, 1);
return 1;
}
file = argv[optind];
ret = check_mounted(file);
if (ret < 0) {
errno = -ret;
error("could not check mount status: %m");
return 1;
} else if (ret) {
error("%s is mounted", file);
return 1;
}
if (rollback) {
ret = do_rollback(file);
} else {
u32 cf = 0;
cf |= datacsum ? CONVERT_FLAG_DATACSUM : 0;
cf |= packing ? CONVERT_FLAG_INLINE_DATA : 0;
cf |= noxattr ? 0 : CONVERT_FLAG_XATTR;
cf |= copy_fsid;
cf |= copylabel;
ret = do_convert(file, cf, nodesize, fslabel, progress, &features,
csum_type, fsid);
}
if (ret)
return 1;
return 0;
}
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