Btrfs: print btrfs specific info for some fatal error cases

Marc argued that if there are several btrfs filesystems mounted,
while users even don't know which filesystem hit the corrupted
errors something like generation verification failure.

Since @extent_buffer structure has a member @fs_info, let's output
btrfs device info.
Reported-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/disk-io.c

@@ -348,9 +348,9 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 		ret = 0;
 		goto out;
 	}
-	printk_ratelimited("parent transid verify failed on %llu wanted %llu "
-		       "found %llu\n",
-		       eb->start, parent_transid, btrfs_header_generation(eb));
+	printk_ratelimited(KERN_INFO "BTRFS (device %s): parent transid verify failed on %llu wanted %llu found %llu\n",
+			eb->fs_info->sb->s_id, eb->start,
+			parent_transid, btrfs_header_generation(eb));
 	ret = 1;
 
 	/*
@@ -614,15 +614,15 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 
 	found_start = btrfs_header_bytenr(eb);
 	if (found_start != eb->start) {
-		printk_ratelimited(KERN_INFO "BTRFS: bad tree block start "
+		printk_ratelimited(KERN_INFO "BTRFS (device %s): bad tree block start "
 			       "%llu %llu\n",
-			       found_start, eb->start);
+			       eb->fs_info->sb->s_id, found_start, eb->start);
 		ret = -EIO;
 		goto err;
 	}
 	if (check_tree_block_fsid(root, eb)) {
-		printk_ratelimited(KERN_INFO "BTRFS: bad fsid on block %llu\n",
-			       eb->start);
+		printk_ratelimited(KERN_INFO "BTRFS (device %s): bad fsid on block %llu\n",
+			       eb->fs_info->sb->s_id, eb->start);
 		ret = -EIO;
 		goto err;
 	}