[PATCH 6.7 104/713] md: Don't clear MD_CLOSING when the raid is about to stop

Sasha Levin
2024-03-24T22:49:03Z

From: Li Nan <linan122@huawei.com>

[ 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>
---
drivers/md/md.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0b49033afa6bc..b2f27ac51bfb6 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6304,7 +6304,15 @@ 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;
@@ -7650,7 +7658,6 @@ 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;
@@ -7734,7 +7741,6 @@ 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);
}
@@ -7876,7 +7882,7 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
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;
}
--
2.43.0