On 2/3/25 4:26 PM, Darrick J. Wong wrote:
> On Mon, Feb 03, 2025 at 09:55:13AM +0100, Lukas Herbolt wrote:
>> If there is corrutpion on the filesystem andxfs_repair
>> fails to repair it. The last resort of getting the data
>> is to use norecovery,ro mount. But if the NEEDSREPAIR is
>> set the filesystem cannot be mounted. The flag must be
>> cleared out manually using xfs_db, to get access to what
>> left over of the corrupted fs.
>>
>> Signed-off-by: Lukas Herbolt <lukas@xxxxxxxxxxx>
>> ---
>> fs/xfs/xfs_super.c | 8 ++++++--
>> 1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
>> index 394fdf3bb535..c2566dcc4f88 100644
>> --- a/fs/xfs/xfs_super.c
>> +++ b/fs/xfs/xfs_super.c
>> @@ -1635,8 +1635,12 @@ xfs_fs_fill_super(
>> #endif
>> }
>>
>> - /* Filesystem claims it needs repair, so refuse the mount. */
>> - if (xfs_has_needsrepair(mp)) {
>> + /*
>> + * Filesystem claims it needs repair, so refuse the mount unless
>> + * norecovery is also specified, in which case the filesystem can
>> + * be mounted with no risk of further damage.
>> + */
>> + if (xfs_has_needsrepair(mp) && !xfs_has_norecovery(mp)) {
>
> I think a better way to handle badly damaged filesystems is for us to
> provide a means to extract directory trees in userspace, rather than
> making the user take the risk of mounting a known-bad filesystem.
> I've a draft of an xfs_db subcommand for doing exactly that and will
> share for xfsprogs 6.14.
I think whether a userspace extractor is better or not depends on the
usecase. I suppose there's some truth that a NEEDSREPAIR filesystem is
"known bad" but we already suffer the risk of "unknown bad" filesystems
today. (Or for that matter, the fact that we allow "norecovery" today,
which also guarantees a mount of an inconsistent filesystem.)
"Something is wrong with this filesystem, let's mount it readonly and
copy off the data" is a pretty time-tested approach, I think, hampered
only by the fairly recent addition of NEEDSREPAIR.
a userspace scrape-the-device tool may well be useful for some, but
I don't think that vs. this kernelspace option needs to be an either/or
decision.
Thanks,
-Eric
> --D
>
>> xfs_warn(mp, "Filesystem needs repair. Please run xfs_repair.");
>> error = -EFSCORRUPTED;
>> goto out_free_sb;
>> --
>> 2.48.1
>>
>>
>
