[Libguestfs] [PATCH 1/2] sparsify: ignore read-only btrfs snapshots (RHBZ#1079625)

In copy mode, make sure to not zero-free-space read-only btrfs snapshots, as we cannot write to them. --- sparsify/copying.ml | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/sparsify/copying.ml b/sparsify/copying.ml index 8d77964..4c23939 100644 --- a/sparsify/copying.ml +++ b/sparsify/copying.ml @@ -208,6 +208,11 @@ You can ignore this warning or change it to a hard failure using the * and selected swap partitions. *) let filesystems = g#list_filesystems () in + let btrfs_filesystems = List.filter ( + fun (fs, fstype) -> + fstype = "btrfs" + ) filesystems in + let btrfs_filesystems = List.map fst btrfs_filesystems in let filesystems = List.map fst filesystems in let filesystems = List.sort compare filesystems in @@ -216,6 +221,18 @@ You can ignore this warning or change it to a hard failure using the List.exists (fun fs' -> fs = g#canonical_device_name fs') ignores in + let is_readonly_btrfs_snapshot fs mp = + try + let is_btrfs = List.mem fs btrfs_filesystems in + if is_btrfs then ( + try + let vol_info = g#btrfs_subvolume_show mp in + string_find (List.assoc "Flags" vol_info) "readonly" <> -1 + with _ -> false + ) else false + with Not_found -> false + in + List.iter ( fun fs -> if not (is_ignored fs) then ( @@ -230,10 +247,15 @@ You can ignore this warning or change it to a hard failure using the with _ -> false in if mounted then ( - if not quiet then - printf (f_"Fill free space in %s with zero ...\n%!") fs; + if is_readonly_btrfs_snapshot fs "/" then ( + if not quiet then + printf (f_"Skipping %s, as it is a read-only btrfs snapshot.\n%!") fs; + ) else ( + if not quiet then + printf (f_"Fill free space in %s with zero ...\n%!") fs; - g#zero_free_space "/" + g#zero_free_space "/" + ) ) else ( let is_linux_x86_swap = (* Look for the signature for Linux swap on i386. -- 1.9.3