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 <[email protected]> --- v2: Newly introduced to inform kernel and progs not to open fs with unfinished uuid change. --- props.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/props.c b/props.c index 59e09b3..0a1bc1e 100644 --- a/props.c +++ b/props.c @@ -351,6 +351,38 @@ out: return ret; } +static int change_id_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; + if (fs_info->new_chunk_tree_uuid) + flags |= BTRFS_SUPER_FLAG_CHANGING_CHUNK_TREE_ID; + btrfs_set_super_flags(fs_info->super_copy, flags); + + return write_all_supers(fs_info->tree_root); +} + +static int change_id_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; + if (fs_info->new_chunk_tree_uuid) + flags &= ~BTRFS_SUPER_FLAG_CHANGING_CHUNK_TREE_ID; + btrfs_set_super_flags(fs_info->super_copy, flags); + + return write_all_supers(fs_info->tree_root); +} + const struct prop_handler prop_handlers[] = { {"ro", "Set/get read-only flag of subvolume.", 0, prop_object_subvol, prop_read_only}, -- 2.4.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
