On 7.02.20 г. 3:59 ч., Qu Wenruo wrote:
> Current _btrfs_get_subvolid() can't handle the following case at all:
> # btrfs subvol list $SCRATCH_MNT
> ID 256 gen 9 top level 5 path subv1
> ID 257 gen 7 top level 256 path subv1/subv2
> ID 258 gen 8 top level 256 path subv1/subv3
> ID 259 gen 9 top level 256 path subv1/subv4
>
> If we call "_btrfs_get_subvolid $SCRATCH_MNT subv1" we will get a list
> of all subvolumes, not the subvolid of subv1.
>
> To address this problem, we go egrep to match $name which starts with a
> space, and at the end of a line.
> So that all other subvolumes won't hit.
>
> Suggested-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> common/btrfs | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/common/btrfs b/common/btrfs
> index 19ac7cc4..85b33e4c 100644
> --- a/common/btrfs
> +++ b/common/btrfs
> @@ -7,7 +7,7 @@ _btrfs_get_subvolid()
> mnt=$1
> name=$2
>
> - $BTRFS_UTIL_PROG sub list $mnt | grep $name | awk '{ print $2 }'
> + $BTRFS_UTIL_PROG sub list $mnt | egrep "\s$name$" | awk '{ print $2 }'
nit: But you don't even need egrep for this, you could have simply used
"grep $name$"
> }
>
> # _require_btrfs_command <command> [<subcommand>|<option>]
>
