On 2/10/20 3:10 PM, Vincent Fazio wrote:
> Previously, XFS would fail to mount if there was an error during log
> recovery. This can occur as a result of inevitable I/O errors when
> trying to apply the log on read-only ATA devices since the ATA layer
> does not support reporting a device as read-only.
>
> Now, if there's an error during log recovery, fall back to norecovery
> mode and mark the filesystem as read-only in the XFS and VFS layers.
>
> This roughly approximates the 'errors=remount-ro' mount option in ext4
> but is implicit and the scope only covers errors during log recovery.
> Since XFS is the default filesystem for some distributions, this change
> allows users to continue to use XFS on these read-only ATA devices.
What is the workload or scenario where you need this behavior?
I'm not a big fan of ~silently mounting a filesystem with latent errors,
tbh, but maybe you can explain a bit more about the problem you're solving
here?
Thanks,
-Eric
> Reviewed-by: Aaron Sierra <asierra@xxxxxxxxxxx>
> Signed-off-by: Vincent Fazio <vfazio@xxxxxxxxxxx>
> ---
> fs/xfs/xfs_log.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index f6006d94a581..f5b3528ee028 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -739,7 +739,6 @@ xfs_log_mount(
> xfs_warn(mp, "log mount/recovery failed: error %d",
> error);
> xlog_recover_cancel(mp->m_log);
> - goto out_destroy_ail;
> }
> }
>
> @@ -3873,10 +3872,17 @@ xfs_log_force_umount(
> /*
> * If this happens during log recovery, don't worry about
> * locking; the log isn't open for business yet.
> + *
> + * Attempt a read-only, norecovery mount. Ensure the VFS layer is updated.
> */
> if (!log ||
> log->l_flags & XLOG_ACTIVE_RECOVERY) {
> - mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
> +
> + xfs_notice(mp,
> +"Falling back to no-recovery mode. Filesystem will be inconsistent.");
> + mp->m_flags |= (XFS_MOUNT_RDONLY | XFS_MOUNT_NORECOVERY);
> + mp->m_super->s_flags |= SB_RDONLY;
> +
> if (mp->m_sb_bp)
> mp->m_sb_bp->b_flags |= XBF_DONE;
> return 0;
>
