md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop

commit 065e519e71b2c1f41936cce75b46b5ab34adb588 upstream.

if called md_set_readonly and set MD_CLOSING bit, the mddev cannot
be opened any more due to the MD_CLOING bit wasn't cleared. Thus it
needs to be cleared in md_ioctl after any call to md_set_readonly()
or do_md_stop().

Signed-off-by: NeilBrown <neilb@suse.com>
Fixes: af8d8e6f0315 ("md: changes for MD_STILL_CLOSED flag")
Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 24925f2aa235..eddd360624a1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6752,6 +6752,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
         void __user *argp = (void __user *)arg;
         struct mddev *mddev = NULL;
         int ro;
+        bool did_set_md_closing = false;
 
         if (!md_ioctl_valid(cmd))
                 return -ENOTTY;
@@ -6841,7 +6842,9 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                         err = -EBUSY;
                         goto out;
                 }
+                WARN_ON_ONCE(test_bit(MD_CLOSING, &mddev->flags));
                 set_bit(MD_CLOSING, &mddev->flags);
+                did_set_md_closing = true;
                 mutex_unlock(&mddev->open_mutex);
                 sync_blockdev(bdev);
         }
@@ -7041,6 +7044,8 @@ unlock:
                 mddev->hold_active = 0;
         mddev_unlock(mddev);
 out:
+        if(did_set_md_closing)
+                clear_bit(MD_CLOSING, &mddev->flags);
         return err;
 }
 #ifdef CONFIG_COMPAT