Hi,
在 2025/08/12 17:01, Kenta Akagi 写道:
It is not intended for the array to fail when a metadata write with
MD_FAILFAST fails.
After commit 9631abdbf406 ("md: Set MD_BROKEN for RAID1 and RAID10"),
when md_error is called on the last device in RAID1/10,
the MD_BROKEN flag is set on the array.
Because of this, a failfast metadata write failure will
make the array "broken" state.
If rdev is not Faulty even after calling md_error,
the rdev is the last device, and there is nothing except
MD_BROKEN that prevents writes to the array.
Therefore, by clearing MD_BROKEN, the array will not become
"broken" after a failfast metadata write failure.
I don't understand here, I think MD_BROKEN is expected, the last
rdev has IO error while updating metadata, the array is now broken
and you can only read it afterwards. Allow using this broken array
read-write might causing more severe problem like data loss.
Thanks,
Kuai
Fixes: 9631abdbf406 ("md: Set MD_BROKEN for RAID1 and RAID10")
Signed-off-by: Kenta Akagi <k@xxxxxxx>
---
drivers/md/md.c | 1 +
drivers/md/md.h | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index ac85ec73a409..3ec4abf02fa0 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1002,6 +1002,7 @@ static void super_written(struct bio *bio)
md_error(mddev, rdev);
if (!test_bit(Faulty, &rdev->flags)
&& (bio->bi_opf & MD_FAILFAST)) {
+ clear_bit(MD_BROKEN, &mddev->flags);
set_bit(MD_SB_NEED_REWRITE, &mddev->sb_flags);
set_bit(LastDev, &rdev->flags);
}
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 51af29a03079..2f87bcc5d834 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -332,7 +332,7 @@ struct md_cluster_operations;
* resync lock, need to release the lock.
* @MD_FAILFAST_SUPPORTED: Using MD_FAILFAST on metadata writes is supported as
* calls to md_error() will never cause the array to
- * become failed.
+ * become failed while fail_last_dev is not set.
* @MD_HAS_PPL: The raid array has PPL feature set.
* @MD_HAS_MULTIPLE_PPLS: The raid array has multiple PPLs feature set.
* @MD_NOT_READY: do_md_run() is active, so 'array_state', ust not report that
