On 1/16/20 11:56 PM, Josef Bacik wrote:
On 10/7/19 5:45 AM, Anand Jain wrote:
In open_fs_devices() we identify alien device but we don't reset its
the device::name. So progs device list does not show the device missing
as shown in the script below.
mkfs.btrfs -fq /dev/sdd && mount /dev/sdd /btrfs
mkfs.btrfs -fq -draid1 -mraid1 /dev/sdc /dev/sdb
sleep 3 # avoid racing with udev's useless scans if needed
btrfs dev add -f /dev/sdb /btrfs
mount -o degraded /dev/sdc /btrfs1
No missing device:
btrfs fi show -m /btrfs1
Label: none uuid: 3eb7cd50-4594-458f-9d68-c243cc49954d
Total devices 2 FS bytes used 128.00KiB
devid 1 size 12.00GiB used 1.26GiB path /dev/sdc
devid 2 size 12.00GiB used 1.26GiB path /dev/sdb
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Why not just remove the device if there's any error? I'm not sure why
these particular checks make a difference from any other error? Thanks,
That's interesting, but disadvantage is user has to re-run the
device scan if we remove the device for a non-alien device which can
fail temporarily in btrfs_open_one_device() function stack such as
*bdev = blkdev_get_by_path(device_path, flags, holder);
If user land has opened the device with O_EXCL this shall
fail with -EBUSY. So here we shouldn't remove.
ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE);
This can fail if the bdev does not accept the blocksize and its
rather a good idea to remove the device as we won't be able to
use this device any time. So as this is not a temporary issue,
here we could remove the device.
*bh = btrfs_read_dev_super(*bdev);
This function is still an incomplete (because we don't yet handle
the corrupted super block #1, there is a patch in the ML but
in dispute, I think). Needs clarity on how a completed function
will look like. So here it depends on when this function completes.
bh = __bread(bdev, bytenr / BTRFS_BDEV_BLOCKSIZE,
BTRFS_SUPER_INFO_SIZE);
Read can fail momentarily for transport/disconnect/plug-out issue
and which can reappears and assume if there isn't systemd auto scan
so here we shouldn't remove.
Thanks, Anand
Josef
