[PATCH 03/17] btrfs: call btrfs_close_devices from ->kill_sb

[Christoph Hellwig <hch@lst.de>]

blkdev_put must not be called under sb->s_umount to avoid a lock order
reversal with disk->open_mutex once call backs from block devices to
the file system using the holder ops are supported.  Move the call
to btrfs_close_devices into btrfs_free_fs_info so that it is closed
from ->kill_sb (which is also called from the mount failure handling
path unlike ->put_super) as well as when an fs_info is freed because
an existing superblock already exists.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/btrfs/disk-io.c | 4 ++--
 fs/btrfs/super.c   | 7 ++-----
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 7513388b0567be..3788b55638392e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1243,6 +1243,8 @@ static void free_global_roots(struct btrfs_fs_info *fs_info)
 
 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 {
+	if (fs_info->fs_devices)
+		btrfs_close_devices(fs_info->fs_devices);
 	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
 	percpu_counter_destroy(&fs_info->delalloc_bytes);
 	percpu_counter_destroy(&fs_info->ordered_bytes);
@@ -3554,7 +3556,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 
 	iput(fs_info->btree_inode);
 fail:
-	btrfs_close_devices(fs_info->fs_devices);
 	ASSERT(ret < 0);
 	return ret;
 }
@@ -4408,7 +4409,6 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info)
 #endif
 
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
-	btrfs_close_devices(fs_info->fs_devices);
 }
 
 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b318bddefd5236..2bbc041ac2e2c5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1494,7 +1494,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 
 	if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
 		error = -EACCES;
-		goto error_close_devices;
+		goto error_fs_info;
 	}
 
 	bdev = fs_devices->latest_dev->bdev;
@@ -1502,11 +1502,10 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 		 fs_info);
 	if (IS_ERR(s)) {
 		error = PTR_ERR(s);
-		goto error_close_devices;
+		goto error_fs_info;
 	}
 
 	if (s->s_root) {
-		btrfs_close_devices(fs_devices);
 		btrfs_free_fs_info(fs_info);
 		if ((flags ^ s->s_flags) & SB_RDONLY)
 			error = -EBUSY;
@@ -1527,8 +1526,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 
 	return dget(s->s_root);
 
-error_close_devices:
-	btrfs_close_devices(fs_devices);
 error_fs_info:
 	btrfs_free_fs_info(fs_info);
 error_sec_opts:
-- 
2.39.2