From: Xiao Ni xni@redhat.com
commit 143f6e733b73051cd22dcb80951c6c929da413ce upstream.
7471fb77ce4d ("md/raid6: Fix anomily when recovering a single device in RAID6.") avoids rereading P when it can be computed from other members. However, this misses the chance to re-write the right data to P. This patch sets R5_ReadError if the re-read fails.
Also, when re-read is skipped, we also missed the chance to reset rdev->read_errors to 0. It can fail the disk when there are many read errors on P member disk (other disks don't have read error)
V2: upper layer read request don't read parity/Q data. So there is no need to consider such situation.
This is Reported-by: kbuild test robot lkp@intel.com
Fixes: 7471fb77ce4d ("md/raid6: Fix anomily when recovering a single device in RAID6.") Cc: stable@vger.kernel.org #4.4+ Signed-off-by: Xiao Ni xni@redhat.com Signed-off-by: Song Liu songliubraving@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/raid5.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2573,7 +2573,9 @@ static void raid5_end_read_request(struc && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) retry = 1; if (retry) - if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) { + if (sh->qd_idx >= 0 && sh->pd_idx == i) + set_bit(R5_ReadError, &sh->dev[i].flags); + else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) { set_bit(R5_ReadError, &sh->dev[i].flags); clear_bit(R5_ReadNoMerge, &sh->dev[i].flags); } else