xfs: close the external block devices in xfs_mount_free

blkdev_put must not be called under sb->s_umount to avoid a lock order
reversal with disk->open_mutex.  Move closing the buftargs into ->kill_sb
to archive that.  Note that the flushing of the disk caches and
block device mapping invalidated needs to stay in ->put_super as the main
block device is closed in kill_block_super already.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Message-Id: <20230809220545.1308228-7-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 65110df..f2e5a2c 100644 (file)
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1945,8 +1945,6 @@ xfs_free_buftarg(
        percpu_counter_destroy(&btp->bt_io_count);
        list_lru_destroy(&btp->bt_lru);
 
-       blkdev_issue_flush(btp->bt_bdev);
-       invalidate_bdev(btp->bt_bdev);
        fs_put_dax(btp->bt_daxdev, btp->bt_mount);
        /* the main block device is closed by kill_block_super */
        if (bdev != btp->bt_mount->m_super->s_bdev)

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 332e32d..18d34e8 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -407,22 +407,19 @@ xfs_blkdev_get(
 }
 
 STATIC void
-xfs_close_devices(
+xfs_shutdown_devices(
        struct xfs_mount        *mp)
 {
        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
-               struct block_device *logdev = mp->m_logdev_targp->bt_bdev;
-
-               xfs_free_buftarg(mp->m_logdev_targp);
-               blkdev_put(logdev, mp);
+               blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
+               invalidate_bdev(mp->m_logdev_targp->bt_bdev);
        }
        if (mp->m_rtdev_targp) {
-               struct block_device *rtdev = mp->m_rtdev_targp->bt_bdev;
-
-               xfs_free_buftarg(mp->m_rtdev_targp);
-               blkdev_put(rtdev, mp);
+               blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
+               invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
        }
-       xfs_free_buftarg(mp->m_ddev_targp);
+       blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
+       invalidate_bdev(mp->m_ddev_targp->bt_bdev);
 }
 
 /*
@@ -750,6 +747,17 @@ static void
 xfs_mount_free(
        struct xfs_mount        *mp)
 {
+       /*
+        * Free the buftargs here because blkdev_put needs to be called outside
+        * of sb->s_umount, which is held around the call to ->put_super.
+        */
+       if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
+               xfs_free_buftarg(mp->m_logdev_targp);
+       if (mp->m_rtdev_targp)
+               xfs_free_buftarg(mp->m_rtdev_targp);
+       if (mp->m_ddev_targp)
+               xfs_free_buftarg(mp->m_ddev_targp);
+
        kfree(mp->m_rtname);
        kfree(mp->m_logname);
        kmem_free(mp);
@@ -1135,7 +1143,7 @@ xfs_fs_put_super(
        xfs_inodegc_free_percpu(mp);
        xfs_destroy_percpu_counters(mp);
        xfs_destroy_mount_workqueues(mp);
-       xfs_close_devices(mp);
+       xfs_shutdown_devices(mp);
 }
 
 static long
@@ -1508,7 +1516,7 @@ xfs_fs_fill_super(
 
        error = xfs_init_mount_workqueues(mp);
        if (error)
-               goto out_close_devices;
+               goto out_shutdown_devices;
 
        error = xfs_init_percpu_counters(mp);
        if (error)
@@ -1722,8 +1730,8 @@ xfs_fs_fill_super(
        xfs_destroy_percpu_counters(mp);
  out_destroy_workqueues:
        xfs_destroy_mount_workqueues(mp);
- out_close_devices:
-       xfs_close_devices(mp);
+ out_shutdown_devices:
+       xfs_shutdown_devices(mp);
        return error;
 
  out_unmount: