btrfs-progs: btrfstune: add ability to restore unfinished fsid change

Now change_uuid() can auto detected unfinished fsid change and restore
it.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
Qu Wenruo 2015-05-15 14:28:24 +08:00 committed by David Sterba
parent e737a9d56b
commit 0522713f3c

View File

@ -267,7 +267,9 @@ out:
static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *tree_root = fs_info->tree_root;
u64 flags = btrfs_super_flags(fs_info->super_copy);
int ret = 0;
if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
return 0;
@ -276,7 +278,16 @@ static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
btrfs_set_super_flags(fs_info->super_copy, flags);
return write_all_supers(fs_info->tree_root);
memcpy(fs_info->super_copy->fsid, fs_info->new_fsid, BTRFS_FSID_SIZE);
ret = write_all_supers(tree_root);
if (ret < 0)
return ret;
/* also restore new chunk_tree_id into tree_root for restore */
write_extent_buffer(tree_root->node, fs_info->new_chunk_tree_uuid,
btrfs_header_chunk_tree_uuid(tree_root->node),
BTRFS_UUID_SIZE);
return write_tree_block(NULL, tree_root, tree_root->node);
}
static int change_fsid_done(struct btrfs_fs_info *fs_info)
@ -293,10 +304,32 @@ static int change_fsid_done(struct btrfs_fs_info *fs_info)
return write_all_supers(fs_info->tree_root);
}
/*
* Return 0 for no unfinished fsid change.
* Return >0 for unfinished fsid change, and restore unfinished fsid/
* chunk_tree_id into fsid_ret/chunk_id_ret.
*/
static int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
uuid_t fsid_ret, uuid_t chunk_id_ret)
{
struct btrfs_root *tree_root = fs_info->tree_root;
u64 flags = btrfs_super_flags(fs_info->super_copy);
if (flags & BTRFS_SUPER_FLAG_CHANGING_FSID) {
memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
read_extent_buffer(tree_root->node, chunk_id_ret,
btrfs_header_chunk_tree_uuid(tree_root->node),
BTRFS_UUID_SIZE);
return 1;
}
return 0;
}
/*
* Change fsid of a given fs.
*
* If new_fsid_str is not given, use a random generated UUID.
* Caller should check new_fsid_str is valid
*/
static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
{
@ -305,13 +338,26 @@ static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
int ret = 0;
/* caller should do extra check on passed uuid */
if (new_fsid_str)
uuid_parse(new_fsid_str, new_fsid);
else
uuid_generate(new_fsid);
if (check_unfinished_fsid_change(fs_info, new_fsid, new_chunk_id)) {
if (new_fsid_str) {
uuid_t tmp;
uuid_generate(new_chunk_id);
uuid_parse(new_fsid_str, tmp);
if (memcmp(tmp, new_fsid, BTRFS_FSID_SIZE)) {
fprintf(stderr,
"ERROR: New fsid %s is not the same with unfinished fsid change\n",
new_fsid_str);
return -EINVAL;
}
}
} else {
if (new_fsid_str)
uuid_parse(new_fsid_str, new_fsid);
else
uuid_generate(new_fsid);
uuid_generate(new_chunk_id);
}
fs_info->new_fsid = new_fsid;
fs_info->new_chunk_tree_uuid = new_chunk_id;