btrfs: don't double-defer bio completions for compressed reads

The bio completion handler of the bio used for the compressed data is
already run in a workqueue using btrfs_bio_wq_end_io, so don't schedule
the completion of the original bio to the same workqueue again but just
execute it directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -2631,12 +2631,6 @@ void btrfs_submit_data_read_bio(struct inode *inode, struct bio *bio,
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	blk_status_t ret;
 
-	ret = btrfs_bio_wq_end_io(fs_info, bio,
-			btrfs_is_free_space_inode(BTRFS_I(inode)) ?
-			BTRFS_WQ_ENDIO_FREE_SPACE : BTRFS_WQ_ENDIO_DATA);
-	if (ret)
-		goto out;
-
 	if (compress_type != BTRFS_COMPRESS_NONE) {
 		/*
 		 * btrfs_submit_compressed_read will handle completing the bio
@@ -2646,6 +2640,12 @@ void btrfs_submit_data_read_bio(struct inode *inode, struct bio *bio,
 		return;
 	}
 
+	ret = btrfs_bio_wq_end_io(fs_info, bio,
+			btrfs_is_free_space_inode(BTRFS_I(inode)) ?
+			BTRFS_WQ_ENDIO_FREE_SPACE : BTRFS_WQ_ENDIO_DATA);
+	if (ret)
+		goto out;
+
 	/*
 	 * Lookup bio sums does extra checks around whether we need to csum or
 	 * not, which is why we ignore skip_sum here.