Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.19 26/33] md: Flush workqueue md_rdev_misc_wq in md_alloc() | Date | Tue, 30 Aug 2022 13:18:17 -0400 |
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From: David Sloan <david.sloan@eideticom.com>
[ Upstream commit 5e8daf906f890560df430d30617c692a794acb73 ]
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@eideticom.com> [logang@deltatee.com: rewrote commit message] Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/md/md.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/md/md.c b/drivers/md/md.c index 522b3d6b8c46b..3f31db141b2f2 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5647,6 +5647,7 @@ static int md_alloc(dev_t dev, char *name) * removed (mddev_delayed_delete). */ flush_workqueue(md_misc_wq); + flush_workqueue(md_rdev_misc_wq); mutex_lock(&disks_mutex); mddev = mddev_alloc(dev); -- 2.35.1
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