This is a note to let you know that I've just added the patch titled
md: Flush workqueue md_rdev_misc_wq in md_alloc()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-flush-workqueue-md_rdev_misc_wq-in-md_alloc.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5e8daf906f890560df430d30617c692a794acb73 Mon Sep 17 00:00:00 2001
From: David Sloan <david.sloan@xxxxxxxxxxxxx>
Date: Thu, 11 Aug 2022 11:14:13 -0600
Subject: md: Flush workqueue md_rdev_misc_wq in md_alloc()
From: David Sloan <david.sloan@xxxxxxxxxxxxx>
commit 5e8daf906f890560df430d30617c692a794acb73 upstream.
A race condition still exists when removing and re-creating md devices
in test cases. However, it is only seen on some setups.
The race condition was tracked down to a reference still being held
to the kobject by the rdev in the md_rdev_misc_wq which will be released
in rdev_delayed_delete().
md_alloc() waits for previous deletions by waiting on the md_misc_wq,
but the md_rdev_misc_wq may still be holding a reference to a recently
removed device.
To fix this, also flush the md_rdev_misc_wq in md_alloc().
Signed-off-by: David Sloan <david.sloan@xxxxxxxxxxxxx>
[logang@xxxxxxxxxxxx: rewrote commit message]
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5683,6 +5683,7 @@ static int md_alloc(dev_t dev, char *nam
* completely removed (mddev_delayed_delete).
*/
flush_workqueue(md_misc_wq);
+ flush_workqueue(md_rdev_misc_wq);
mutex_lock(&disks_mutex);
error = -EEXIST;
Patches currently in stable-queue which might be from david.sloan@xxxxxxxxxxxxx are
queue-5.10/md-flush-workqueue-md_rdev_misc_wq-in-md_alloc.patch
