Commit 9f43d0ff authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: call btrfs_close_devices() from ->kill_sb 



Although btrfs is not yet implementing blk_holder_ops, there is a
requirement for proper blk_holder_ops:

- blkdev_put() must not be called under sb->s_umount
  The blkdev_put()/bdev_fput() must not be called under sb->s_umount to
  avoid lock order reversal with disk->open_mutex.
  This is for the proper blk_holder_ops callbacks.

  Currently we're fine because we call regular fput() which defers the
  blk holder reclaiming.

To prepare for the future of blk_holder_ops, move the
btrfs_close_devices() calls into btrfs_free_fs_info().

That will be called from kill_sb() callbacks, which is also called for
error handing during mount failures, or there is already an existing
super block.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 2936a6ac

fs/btrfs/disk-io.c

+2 −2
Original line number Diff line number Diff line
@@ -1246,6 +1246,8 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info) 
{

	struct percpu_counter *em_counter = &fs_info->evictable_extent_maps;



	if (fs_info->fs_devices)

		btrfs_close_devices(fs_info->fs_devices);

	percpu_counter_destroy(&fs_info->stats_read_blocks);

	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);

	percpu_counter_destroy(&fs_info->delalloc_bytes);
@@ -3681,7 +3683,6 @@ 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;

}
@@ -4428,7 +4429,6 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info) 
	iput(fs_info->btree_inode);



	btrfs_mapping_tree_free(fs_info);

	btrfs_close_devices(fs_info->fs_devices);

}



void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,

fs/btrfs/super.c

+8 −19
Original line number Diff line number Diff line
@@ -1869,18 +1869,14 @@ static int btrfs_get_tree_super(struct fs_context *fc) 
	if (ret)

		return ret;



	if (!(fc->sb_flags & SB_RDONLY) && fs_devices->rw_devices == 0) {

		ret = -EACCES;

		goto error;

	}

	if (!(fc->sb_flags & SB_RDONLY) && fs_devices->rw_devices == 0)

		return -EACCES;



	bdev = fs_devices->latest_dev->bdev;



	sb = sget_fc(fc, btrfs_fc_test_super, set_anon_super_fc);

	if (IS_ERR(sb)) {

		ret = PTR_ERR(sb);

		goto error;

	}

	if (IS_ERR(sb))

		return PTR_ERR(sb);



	set_device_specific_options(fs_info);
@@ -1888,17 +1884,14 @@ static int btrfs_get_tree_super(struct fs_context *fc) 
		/*

		 * Not the first mount of the fs thus got an existing super block.

		 * Will reuse the returned super block, fs_info and fs_devices.

		 */

		ASSERT(fc->s_fs_info == fs_info);



		/*

		 *

		 * fc->s_fs_info is not touched and will be later freed by

		 * put_fs_context() through btrfs_free_fs_context().

		 *

		 * But we have opened fs_devices at the beginning of the

		 * function, thus still need to close them manually.

		 * The fs_info->fs_devices will also be closed by btrfs_free_fs_context().

		 */

		btrfs_close_devices(fs_devices);

		ASSERT(fc->s_fs_info == fs_info);



		/*

		 * At this stage we may have RO flag mismatch between

		 * fc->sb_flags and sb->s_flags.  Caller should detect such
@@ -1927,10 +1920,6 @@ static int btrfs_get_tree_super(struct fs_context *fc) 


	fc->root = dget(sb->s_root);

	return 0;



error:

	btrfs_close_devices(fs_devices);

	return ret;

}



/*