btrfs-progs: Introduce change_fsid_prepare and change_fsid_done functions

These two functions will write flags to all supers before and after
fsid/chunk tree id change, informing kernel not to mount a inconsistent
fs.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[removed chunk tree super flag]
Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
Qu Wenruo 2015-05-13 16:41:51 +02:00 committed by David Sterba
parent 01cdf01ecf
commit d275dbd183
1 changed files with 28 additions and 0 deletions

View File

@ -262,6 +262,34 @@ out:
return ret;
}
static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
{
u64 flags = btrfs_super_flags(fs_info->super_copy);
if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
return 0;
if (fs_info->new_fsid)
flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
btrfs_set_super_flags(fs_info->super_copy, flags);
return write_all_supers(fs_info->tree_root);
}
static int change_fsid_done(struct btrfs_fs_info *fs_info)
{
u64 flags = btrfs_super_flags(fs_info->super_copy);
if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
return 0;
if (fs_info->new_fsid)
flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
btrfs_set_super_flags(fs_info->super_copy, flags);
return write_all_supers(fs_info->tree_root);
}
static void print_usage(void)
{
fprintf(stderr, "usage: btrfstune [options] device\n");