On 7.02.20 г. 12:02 ч., Qu Wenruo wrote:
>
>
> On 2020/2/7 下午5:41, Nikolay Borisov wrote:
>>
>>
>> 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 $name$"
>
> That \s is needed. Or the following case can't be handled:
>
> ID 256 gen 9 top level 5 path subv1
> ID 257 gen 7 top level 256 path subv1/subv1
Good point.
>
> Thanks,
> Qu
>
>>
>>> }
>>>
>>> # _require_btrfs_command <command> [<subcommand>|<option>]
>>>
