[PATCH 1/2] Btrfs: move kobj stuff out of dev_replace lock range

[Liu Bo <bo.li.liu@oracle.com>]

To avoid deadlock described in commit 084b6e7c7607 ("btrfs: Fix a lockdep warning when running xfstest."),
we should move kobj stuff out of dev_replace lock range.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/dev-replace.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 862fbc2..9eb1401 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -376,10 +376,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 	WARN_ON(!tgt_device);
 	dev_replace->tgtdev = tgt_device;
 
-	ret = btrfs_kobj_add_device(tgt_device->fs_devices, tgt_device);
-	if (ret)
-		btrfs_error(root->fs_info, ret, "kobj add dev failed");
-
 	printk_in_rcu(KERN_INFO
 		      "BTRFS: dev_replace from %s (devid %llu) to %s started\n",
 		      src_device->missing ? "<missing disk>" :
@@ -402,6 +398,10 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 	args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
 	btrfs_dev_replace_unlock(dev_replace);
 
+	ret = btrfs_kobj_add_device(tgt_device->fs_devices, tgt_device);
+	if (ret)
+		btrfs_error(root->fs_info, ret, "kobj add dev failed");
+
 	btrfs_wait_ordered_roots(root->fs_info, -1);
 
 	/* force writing the updated state information to disk */
-- 
2.1.0