Patch "md: Don't clear MD_CLOSING when the raid is about to stop" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    md: Don't clear MD_CLOSING when the raid is about to stop

to the 6.6-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-don-t-clear-md_closing-when-the-raid-is-about-to-.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7692ae5e001940d84694149b9b994a032d270271
Author: Li Nan <linan122@xxxxxxxxxx>
Date:   Mon Feb 26 11:14:40 2024 +0800

    md: Don't clear MD_CLOSING when the raid is about to stop
    
    [ Upstream commit 9674f54e41fffaf06f6a60202e1fa4cc13de3cf5 ]
    
    The raid should not be opened anymore when it is about to be stopped.
    However, other processes can open it again if the flag MD_CLOSING is
    cleared before exiting. From now on, this flag will not be cleared when
    the raid will be stopped.
    
    Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop")
    Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
    Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
    Signed-off-by: Song Liu <song@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240226031444.3606764-6-linan666@xxxxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index ce0516bdf8fa8..624259f79337f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6235,7 +6235,15 @@ static void md_clean(struct mddev *mddev)
 	mddev->persistent = 0;
 	mddev->level = LEVEL_NONE;
 	mddev->clevel[0] = 0;
-	mddev->flags = 0;
+	/*
+	 * Don't clear MD_CLOSING, or mddev can be opened again.
+	 * 'hold_active != 0' means mddev is still in the creation
+	 * process and will be used later.
+	 */
+	if (mddev->hold_active)
+		mddev->flags = 0;
+	else
+		mddev->flags &= BIT_ULL_MASK(MD_CLOSING);
 	mddev->sb_flags = 0;
 	mddev->ro = MD_RDWR;
 	mddev->metadata_type[0] = 0;
@@ -7609,7 +7617,6 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
 	int err = 0;
 	void __user *argp = (void __user *)arg;
 	struct mddev *mddev = NULL;
-	bool did_set_md_closing = false;
 
 	if (!md_ioctl_valid(cmd))
 		return -ENOTTY;
@@ -7693,7 +7700,6 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
 			err = -EBUSY;
 			goto out;
 		}
-		did_set_md_closing = true;
 		mutex_unlock(&mddev->open_mutex);
 		sync_blockdev(bdev);
 	}
@@ -7827,7 +7833,7 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
 		mddev->hold_active = 0;
 	mddev_unlock(mddev);
 out:
-	if(did_set_md_closing)
+	if (cmd == STOP_ARRAY_RO || (err && cmd == STOP_ARRAY))
 		clear_bit(MD_CLOSING, &mddev->flags);
 	return err;
 }