From: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Date: Fri, 19 Jul 2013 06:31:34 +0000 (+0800)
Subject: Btrfs-progs: make btrfs-map-logical handle error gracefully
X-Git-Tag: upstream/4.16.1~3208
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=af6c1650cf38395143157a674344e195d47c0517;p=platform%2Fupstream%2Fbtrfs-progs.git

Btrfs-progs: make btrfs-map-logical handle error gracefully

If an overflow logical address is passed(for example),the original
code will cause segmentation, this is unfriendly to users,fix it.

Signed-off-by: Wang Shilong<wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
---

diff --git a/btrfs-map-logical.c b/btrfs-map-logical.c
index b9635f7..fce6504 100644
--- a/btrfs-map-logical.c
+++ b/btrfs-map-logical.c
@@ -57,7 +57,14 @@ struct extent_buffer *debug_read_block(struct btrfs_root *root, u64 bytenr,
 		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
 				      eb->start, &length, &multi,
 				      mirror_num, NULL);
-		BUG_ON(ret);
+		if (ret) {
+			fprintf(info_file,
+				"Error: fails to map mirror%d logical %llu: %s\n",
+				mirror_num, (unsigned long long)eb->start,
+				strerror(-ret));
+			free_extent_buffer(eb);
+			return NULL;
+		}
 		device = multi->stripes[0].dev;
 		eb->fd = device->fd;
 		device->total_ios++;