Hi,
在 2023/12/02 4:53, Song Liu 写道:
On Tue, Nov 28, 2023 at 8:32 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
From: Yu Kuai <yukuai3@xxxxxxxxxx>
If md_set_readonly() failed, the array could still be read-write, however
'MD_RECOVERY_FROZEN' could still be set, which leave the array in an
abnormal state that sync or recovery can't continue anymore.
Hence make sure the flag is cleared after md_set_readonly() returns.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Acked-by: Xiao Ni <xni@xxxxxxxxxx>
Since we are shipping this via the md-fixes branch, we need a Fixes tag.
Okay, I'll add following fix tag:
Fixes: 88724bfa68be ("md: wait for pending superblock updates before
switching to read-only")
---
drivers/md/md.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5640a948086b..2d8e45a1af23 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6355,6 +6355,9 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
int err = 0;
int did_freeze = 0;
+ if (mddev->external && test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
+ return -EBUSY;
+
if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
did_freeze = 1;
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
@@ -6369,8 +6372,6 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
*/
md_wakeup_thread_directly(mddev->sync_thread);
- if (mddev->external && test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
- return -EBUSY;
mddev_unlock(mddev);
wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
&mddev->recovery));
@@ -6383,29 +6384,30 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
pr_warn("md: %s still in use.\n",mdname(mddev));
- if (did_freeze) {
- clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
- md_wakeup_thread(mddev->thread);
- }
This change (move did_freeze, etc.) is not explained in the commit log.
Is it just refactor?
It is refactor, but it is also part of "make sure the flag is cleared
after md_set_readonly() returns", because now that MD_RECOVERY_FROZEN
will be cleared:
if ((mddev->pers && !err) || did_freeze)
Which means,
- If set readonly succeed, or;
- if something is wrong and did_freeze is set, exactly what this patch
tries to do;
Thanks,
Kuai
Thanks,
Song
err = -EBUSY;
goto out;
}
+
if (mddev->pers) {
__md_stop_writes(mddev);
- err = -ENXIO;
- if (mddev->ro == MD_RDONLY)
+ if (mddev->ro == MD_RDONLY) {
+ err = -ENXIO;
goto out;
+ }
+
mddev->ro = MD_RDONLY;
set_disk_ro(mddev->gendisk, 1);
+ }
+
+out:
+ if ((mddev->pers && !err) || did_freeze) {
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
sysfs_notify_dirent_safe(mddev->sysfs_state);
- err = 0;
}
-out:
+
mutex_unlock(&mddev->open_mutex);
return err;
}
--
2.39.2
.
