在 2025/8/29 0:32, Kenta Akagi 写道:
This commit ensures that an MD_FAILFAST IO failure does not put
the array into a broken state.
When failfast is enabled on rdev in RAID1 or RAID10,
the array may be flagged MD_BROKEN in the following cases.
- If MD_FAILFAST IOs to multiple rdevs fail simultaneously
- If an MD_FAILFAST metadata write to the 'last' rdev fails
[...]
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 408c26398321..8a61fd93b3ff 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -470,6 +470,7 @@ static void raid1_end_write_request(struct bio *bio)
(bio->bi_opf & MD_FAILFAST) &&
/* We never try FailFast to WriteMostly devices */
!test_bit(WriteMostly, &rdev->flags)) {
+ set_bit(FailfastIOFailure, &rdev->flags);
md_error(r1_bio->mddev, rdev);
}
@@ -1746,8 +1747,12 @@ static void raid1_status(struct seq_file *seq, struct mddev *mddev)
* - recovery is interrupted.
* - &mddev->degraded is bumped.
*
- * @rdev is marked as &Faulty excluding case when array is failed and
- * &mddev->fail_last_dev is off.
+ * If @rdev has &FailfastIOFailure and it is the 'last' rdev,
+ * then @mddev and @rdev will not be marked as failed.
+ *
+ * @rdev is marked as &Faulty excluding any cases:
+ * - when @mddev is failed and &mddev->fail_last_dev is off
+ * - when @rdev is last device and &FailfastIOFailure flag is set
*/
static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
{
@@ -1758,6 +1763,13 @@ static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
if (test_bit(In_sync, &rdev->flags) &&
(conf->raid_disks - mddev->degraded) == 1) {
+ if (test_and_clear_bit(FailfastIOFailure, &rdev->flags)) {
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ pr_warn_ratelimited("md/raid1:%s: Failfast IO failure on %pg, "
+ "last device but ignoring it\n",
+ mdname(mddev), rdev->bdev);
+ return;
+ }
set_bit(MD_BROKEN, &mddev->flags);
if (!mddev->fail_last_dev) {
@@ -2148,6 +2160,7 @@ static int fix_sync_read_error(struct r1bio *r1_bio)
if (test_bit(FailFast, &rdev->flags)) {
/* Don't try recovering from here - just fail it
* ... unless it is the last working device of course */
+ set_bit(FailfastIOFailure, &rdev->flags);
md_error(mddev, rdev);
if (test_bit(Faulty, &rdev->flags))
/* Don't try to read from here, but make sure
@@ -2652,6 +2665,7 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
fix_read_error(conf, r1_bio);
unfreeze_array(conf);
} else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
+ set_bit(FailfastIOFailure, &rdev->flags);
md_error(mddev, rdev);
} else {
r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index b60c30bfb6c7..530ad6503189 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -488,6 +488,7 @@ static void raid10_end_write_request(struct bio *bio)
dec_rdev = 0;
if (test_bit(FailFast, &rdev->flags) &&
(bio->bi_opf & MD_FAILFAST)) {
+ set_bit(FailfastIOFailure, &rdev->flags);
md_error(rdev->mddev, rdev);
}
Thank you for the patch. There may be an issue with 'test_and_clear'.
If two write IO go to the same rdev, MD_BROKEN may be set as below:
IO1 IO2
set FailfastIOFailure
set FailfastIOFailure
md_error
raid1_error
test_and_clear FailfastIOFailur
md_error
raid1_error
//FailfastIOFailur is cleared
set MD_BROKEN
Maybe we should check whether FailfastIOFailure is already set before
setting it. It also needs to be considered in metadata writes.
@@ -1995,8 +1996,12 @@ static int enough(struct r10conf *conf, int ignore)
* - recovery is interrupted.
* - &mddev->degraded is bumped.
*
- * @rdev is marked as &Faulty excluding case when array is failed and
- * &mddev->fail_last_dev is off.
+ * If @rdev has &FailfastIOFailure and it is the 'last' rdev,
+ * then @mddev and @rdev will not be marked as failed.
+ *
+ * @rdev is marked as &Faulty excluding any cases:
+ * - when @mddev is failed and &mddev->fail_last_dev is off
+ * - when @rdev is last device and &FailfastIOFailure flag is set
*/
static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
{
@@ -2006,6 +2011,13 @@ static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags) && !enough(conf, rdev->raid_disk)) {
+ if (test_and_clear_bit(FailfastIOFailure, &rdev->flags)) {
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ pr_warn_ratelimited("md/raid10:%s: Failfast IO failure on %pg, "
+ "last device but ignoring it\n",
+ mdname(mddev), rdev->bdev);
+ return;
+ > set_bit(MD_BROKEN, &mddev->flags);
if (!mddev->fail_last_dev) {
@@ -2413,6 +2425,7 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
continue;
} else if (test_bit(FailFast, &rdev->flags)) {
/* Just give up on this device */
+ set_bit(FailfastIOFailure, &rdev->flags);
md_error(rdev->mddev, rdev);
continue;
}
@@ -2865,8 +2878,10 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
freeze_array(conf, 1);
fix_read_error(conf, mddev, r10_bio);
unfreeze_array(conf);
- } else
+ } else {
+ set_bit(FailfastIOFailure, &rdev->flags);
md_error(mddev, rdev);
+ }
rdev_dec_pending(rdev, mddev);
r10_bio->state = 0;
--
Thanks,
Nan
