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@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240226031444.3606764-6-linan666@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index d6f12338cb98999c9c50332b6b3d1155ca21085e..09c7f52156f3f4e79319846110c453a46716f850 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6243,7 +6243,15 @@ 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 = 0;
        mddev->metadata_type[0] = 0;
@@ -7562,7 +7570,6 @@ static int md_ioctl(struct block_device *bdev, fmode_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;
@@ -7649,7 +7656,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                        err = -EBUSY;
                        goto out;
                }
-               did_set_md_closing = true;
                mutex_unlock(&mddev->open_mutex);
                sync_blockdev(bdev);
        }
@@ -7813,7 +7819,7 @@ unlock:
                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;
 }