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author | Nigel Croxon <ncroxon@redhat.com> | 2019-03-29 20:46:15 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-16 20:41:28 +0300 |
commit | 85f347944a6b5235a202aee717a765e5d60dbb24 (patch) | |
tree | f40f07e388adb9964e3705823fd51d3a6a3bbe4e | |
parent | ace28a8efdd4a22bebc6f3ac374afbb958d1ff4a (diff) | |
download | linux-85f347944a6b5235a202aee717a765e5d60dbb24.tar.xz |
Don't jump to compute_result state from check_result state
commit 4f4fd7c5798bbdd5a03a60f6269cf1177fbd11ef upstream.
Changing state from check_state_check_result to
check_state_compute_result not only is unsafe but also doesn't
appear to serve a valid purpose. A raid6 check should only be
pushing out extra writes if doing repair and a mis-match occurs.
The stripe dev management will already try and do repair writes
for failing sectors.
This patch makes the raid6 check_state_check_result handling
work more like raid5's. If somehow too many failures for a
check, just quit the check operation for the stripe. When any
checks pass, don't try and use check_state_compute_result for
a purpose it isn't needed for and is unsafe for. Just mark the
stripe as in sync for passing its parity checks and let the
stripe dev read/write code and the bad blocks list do their
job handling I/O errors.
Repro steps from Xiao:
These are the steps to reproduce this problem:
1. redefined OPT_MEDIUM_ERR_ADDR to 12000 in scsi_debug.c
2. insmod scsi_debug.ko dev_size_mb=11000 max_luns=1 num_tgts=1
3. mdadm --create /dev/md127 --level=6 --raid-devices=5 /dev/sde1 /dev/sde2 /dev/sde3 /dev/sde5 /dev/sde6
sde is the disk created by scsi_debug
4. echo "2" >/sys/module/scsi_debug/parameters/opts
5. raid-check
It panic:
[ 4854.730899] md: data-check of RAID array md127
[ 4854.857455] sd 5:0:0:0: [sdr] tag#80 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.859246] sd 5:0:0:0: [sdr] tag#80 Sense Key : Medium Error [current]
[ 4854.860694] sd 5:0:0:0: [sdr] tag#80 Add. Sense: Unrecovered read error
[ 4854.862207] sd 5:0:0:0: [sdr] tag#80 CDB: Read(10) 28 00 00 00 2d 88 00 04 00 00
[ 4854.864196] print_req_error: critical medium error, dev sdr, sector 11656 flags 0
[ 4854.867409] sd 5:0:0:0: [sdr] tag#100 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.869469] sd 5:0:0:0: [sdr] tag#100 Sense Key : Medium Error [current]
[ 4854.871206] sd 5:0:0:0: [sdr] tag#100 Add. Sense: Unrecovered read error
[ 4854.872858] sd 5:0:0:0: [sdr] tag#100 CDB: Read(10) 28 00 00 00 2e e0 00 00 08 00
[ 4854.874587] print_req_error: critical medium error, dev sdr, sector 12000 flags 4000
[ 4854.876456] sd 5:0:0:0: [sdr] tag#101 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.878552] sd 5:0:0:0: [sdr] tag#101 Sense Key : Medium Error [current]
[ 4854.880278] sd 5:0:0:0: [sdr] tag#101 Add. Sense: Unrecovered read error
[ 4854.881846] sd 5:0:0:0: [sdr] tag#101 CDB: Read(10) 28 00 00 00 2e e8 00 00 08 00
[ 4854.883691] print_req_error: critical medium error, dev sdr, sector 12008 flags 4000
[ 4854.893927] sd 5:0:0:0: [sdr] tag#166 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.896002] sd 5:0:0:0: [sdr] tag#166 Sense Key : Medium Error [current]
[ 4854.897561] sd 5:0:0:0: [sdr] tag#166 Add. Sense: Unrecovered read error
[ 4854.899110] sd 5:0:0:0: [sdr] tag#166 CDB: Read(10) 28 00 00 00 2e e0 00 00 10 00
[ 4854.900989] print_req_error: critical medium error, dev sdr, sector 12000 flags 0
[ 4854.902757] md/raid:md127: read error NOT corrected!! (sector 9952 on sdr1).
[ 4854.904375] md/raid:md127: read error NOT corrected!! (sector 9960 on sdr1).
[ 4854.906201] ------------[ cut here ]------------
[ 4854.907341] kernel BUG at drivers/md/raid5.c:4190!
raid5.c:4190 above is this BUG_ON:
handle_parity_checks6()
...
BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
Cc: <stable@vger.kernel.org> # v3.16+
OriginalAuthor: David Jeffery <djeffery@redhat.com>
Cc: Xiao Ni <xni@redhat.com>
Tested-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: David Jeffy <djeffery@redhat.com>
Signed-off-by: Nigel Croxon <ncroxon@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/md/raid5.c | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index ae38895c44b2..828d86605fb6 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4221,26 +4221,15 @@ static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh, case check_state_check_result: sh->check_state = check_state_idle; + if (s->failed > 1) + break; /* handle a successful check operation, if parity is correct * we are done. Otherwise update the mismatch count and repair * parity if !MD_RECOVERY_CHECK */ if (sh->ops.zero_sum_result == 0) { - /* both parities are correct */ - if (!s->failed) - set_bit(STRIPE_INSYNC, &sh->state); - else { - /* in contrast to the raid5 case we can validate - * parity, but still have a failure to write - * back - */ - sh->check_state = check_state_compute_result; - /* Returning at this point means that we may go - * off and bring p and/or q uptodate again so - * we make sure to check zero_sum_result again - * to verify if p or q need writeback - */ - } + /* Any parity checked was correct */ + set_bit(STRIPE_INSYNC, &sh->state); } else { atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches); if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) { |