From e9e3fc8b50b1b492f0ee77bd503a729bfc2c98fe Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Fri, 5 May 2017 18:41:00 -0400 Subject: makechrootpkg: sync_chroot: Make more general. This is inspired by the thought that went in to the delete_chroot is_subvolume commit. sync_chroot($chrootdir, $copydir) copies `$chrootdir/root` to `$copydir`. That seems a little silly; why do we care about "$chrootdir"? Have it just be sync_chroot(source, destination) like every other sync/copy command. Where this becomes tricky is check to decide if we are going to use btrfs subvolumes or not. We don't care if "$source/.." is on btrfs; the root could be a directly-mounted subvolume, but and the destination could be another subvolume of the same btrfs mounted somewhere else. The things we do care about are: - The source is a btrfs subvolume (so that we can snapshot it) - The source is on the same filesystem as the directory that the copy will be created in. - If the destination exists: * that it is not a mountpoint (so that we can delete and recreate it) * that it is a btrfs subvolume (so that we can quickly delete it) On the last point, it isn't necessary for creating the new snapshot, just for quick deletion. That can be a separate check, where we use regular `rm` for deleting the existing copy, but use subvolume snapshots for creating the new one. --- lib/archroot.sh | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib') diff --git a/lib/archroot.sh b/lib/archroot.sh index 87c28a2..6b1b52e 100644 --- a/lib/archroot.sh +++ b/lib/archroot.sh @@ -33,6 +33,14 @@ is_subvolume() { [[ -e "$1" && "$(stat -f -c %T "$1")" == btrfs && "$(stat -c %i "$1")" == 256 ]] } +## +# usage : is_same_fs( $path_a, $path_b ) +# return : whether $path_a and $path_b are on the same filesystem +## +is_same_fs() { + [[ "$(stat -c %d "$1")" == "$(stat -c %d "$1")" ]] +} + ## # usage : subvolume_delete_recursive( $path ) # -- cgit v1.2.3-70-g09d2