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authorNeilBrown <neilb@suse.com>2016-12-05 16:40:50 +1100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-12 11:39:35 +0100
commit5cc85ef4ffe6c3f1d35b75975c5731248c5af4a7 (patch)
treef3af49785da96504d22cedc42688cdaecdbc53af
parent60a931c20d1a401b79ff742142225c300d545af0 (diff)
md: fix refcount problem on mddev when stopping array.
commit e2342ca832726a840ca6bd196dd2cc073815b08a upstream. md_open() gets a counted reference on an mddev using mddev_find(). If it ends up returning an error, it must drop this reference. There are two error paths where the reference is not dropped. One only happens if the process is signalled and an awkward time, which is quite unlikely. The other was introduced recently in commit af8d8e6f0. Change the code to ensure the drop the reference when returning an error, and make it harded to re-introduce this sort of bug in the future. Reported-by: Marc Smith <marc.smith@mcc.edu> Fixes: af8d8e6f0315 ("md: changes for MD_STILL_CLOSED flag") Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/md/md.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1a9131b6594c..24925f2aa235 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7092,7 +7092,8 @@ static int md_open(struct block_device *bdev, fmode_t mode)
if (test_bit(MD_CLOSING, &mddev->flags)) {
mutex_unlock(&mddev->open_mutex);
- return -ENODEV;
+ err = -ENODEV;
+ goto out;
}
err = 0;
@@ -7101,6 +7102,8 @@ static int md_open(struct block_device *bdev, fmode_t mode)
check_disk_change(bdev);
out:
+ if (err)
+ mddev_put(mddev);
return err;
}