| Message ID | 20170517014121.8499-1-fdmanana@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 17, 2017 at 02:41:21AM +0100, fdmanana@kernel.org wrote: > From: Filipe Manana <fdmanana@suse.com> > > We correctly build an image from a multiple devices filesystem but when > restoring the image into a single device we were missing updating the > number of devices in the superblock to the value 1 (we already took care > of setting the number of stripes to 1 for each chunk item and setting > the device id for each chunk item to match the device id from the super > block). > > This missing update of the number of devices makes it impossible to mount > the restored filesystem on recent kernels, more specifically since the > linux kernel commit 99e3ecfcb9f4ca35192d20a5bea158b81f600062 > ("Btrfs: add more validation checks for superblock"), that produce the > following message in the dmesg/syslog: > > [21097.542047] BTRFS error (device sdi): super_num_devices 2 mismatch with num_devices 1 found here > [21097.543972] BTRFS error (device sdi): failed to read chunk tree: -22 > [21097.720360] BTRFS error (device sdi): open_ctree failed > > So fix this by updating the number of devices to 1 in the superblock. > > Signed-off-by: Filipe Manana <fdmanana@suse.com> Looks good. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Thanks, -liubo -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, May 18, 2017 at 05:11:35PM -0700, Liu Bo wrote: > On Wed, May 17, 2017 at 02:41:21AM +0100, fdmanana@kernel.org wrote: > > From: Filipe Manana <fdmanana@suse.com> > > > > We correctly build an image from a multiple devices filesystem but when > > restoring the image into a single device we were missing updating the > > number of devices in the superblock to the value 1 (we already took care > > of setting the number of stripes to 1 for each chunk item and setting > > the device id for each chunk item to match the device id from the super > > block). > > > > This missing update of the number of devices makes it impossible to mount > > the restored filesystem on recent kernels, more specifically since the > > linux kernel commit 99e3ecfcb9f4ca35192d20a5bea158b81f600062 > > ("Btrfs: add more validation checks for superblock"), that produce the > > following message in the dmesg/syslog: > > > > [21097.542047] BTRFS error (device sdi): super_num_devices 2 mismatch with num_devices 1 found here > > [21097.543972] BTRFS error (device sdi): failed to read chunk tree: -22 > > [21097.720360] BTRFS error (device sdi): open_ctree failed > > > > So fix this by updating the number of devices to 1 in the superblock. > > > > Signed-off-by: Filipe Manana <fdmanana@suse.com> > > Looks good. > > Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/image/main.c b/image/main.c index f1c28de1..1eca414b 100644 --- a/image/main.c +++ b/image/main.c @@ -1500,6 +1500,7 @@ static int update_super(struct mdrestore_struct *mdres, u8 *buffer) flags |= BTRFS_SUPER_FLAG_METADUMP_V2; btrfs_set_super_flags(super, flags); btrfs_set_super_sys_array_size(super, new_array_size); + btrfs_set_super_num_devices(super, 1); csum_block(buffer, BTRFS_SUPER_INFO_SIZE); return 0;