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authorChao Yu <yuchao0@huawei.com>2018-02-03 17:44:39 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2018-03-13 08:05:40 +0900
commitfb0e72c8b94903be3a7e742ab0a4b53b89e7ee35 (patch)
treefdbc7f7837aeec1a0f453a17b2640cb41249bc4b /fs/f2fs/recovery.c
parent0f9ec2a8f65d72a454e99fb4f7351d7e01070385 (diff)
downloadlinux-fb0e72c8b94903be3a7e742ab0a4b53b89e7ee35.tar.gz
f2fs: fix to handle looped node chain during recovery
There is no checksum in node block now, so bit-transition from hardware
can make node_footer.next_blkaddr being corrupted w/o any detection,
result in node chain becoming looped one.

For this condition, during recovery, in order to avoid running into dead
loop, let's detect it and just skip out.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/recovery.c')
-rw-r--r--fs/f2fs/recovery.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index c5e5c45130b5..1b23d3febe4c 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -242,6 +242,9 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head,
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	block_t blkaddr;
+	unsigned int loop_cnt = 0;
+	unsigned int free_blocks = sbi->user_block_count -
+					valid_user_blocks(sbi);
 	int err = 0;
 
 	/* get node pages in the current segment */
@@ -294,6 +297,17 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head,
 		if (IS_INODE(page) && is_dent_dnode(page))
 			entry->last_dentry = blkaddr;
 next:
+		/* sanity check in order to detect looped node chain */
+		if (++loop_cnt >= free_blocks ||
+			blkaddr == next_blkaddr_of_node(page)) {
+			f2fs_msg(sbi->sb, KERN_NOTICE,
+				"%s: detect looped node chain, "
+				"blkaddr:%u, next:%u",
+				__func__, blkaddr, next_blkaddr_of_node(page));
+			err = -EINVAL;
+			break;
+		}
+
 		/* check next segment */
 		blkaddr = next_blkaddr_of_node(page);
 		f2fs_put_page(page, 1);