[PATCH 3/8] fsck.f2fs: fix corrupted dentries

[Jaegeuk Kim <jaegeuk@kernel.org>]

This patch fixes corrupted dentries such as name_len == 0.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fsck/fsck.c | 47 +++++++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index ecb18f2..debae1c 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -796,22 +796,24 @@ static int __chk_dentries(struct f2fs_sb_info *sbi, u32 *child_cnt,
 	int i;
 
 	/* readahead inode blocks */
-	for (i = 0; i < max;) {
-		if (test_bit(i, bitmap) == 0) {
-			i++;
+	for (i = 0; i < max; i++) {
+		if (test_bit(i, bitmap) == 0)
 			continue;
-		}
+
 		ino = le32_to_cpu(dentry[i].ino);
 
 		if (IS_VALID_NID(sbi, ino)) {
 			struct node_info ni;
 
 			get_node_info(sbi, ino, &ni);
-			if (IS_VALID_BLK_ADDR(sbi, ni.blk_addr))
+			if (IS_VALID_BLK_ADDR(sbi, ni.blk_addr)) {
 				dev_reada_block(ni.blk_addr);
+				name_len = le16_to_cpu(dentry[i].name_len);
+				if (name_len > 0)
+					i += (name_len + F2FS_SLOT_LEN - 1) / F2FS_SLOT_LEN - 1;
+				continue;
+			}
 		}
-		name_len = le16_to_cpu(dentry[i].name_len);
-		i += (name_len + F2FS_SLOT_LEN - 1) / F2FS_SLOT_LEN;
 	}
 
 	for (i = 0; i < max;) {
@@ -820,31 +822,44 @@ static int __chk_dentries(struct f2fs_sb_info *sbi, u32 *child_cnt,
 			continue;
 		}
 		if (!IS_VALID_NID(sbi, le32_to_cpu(dentry[i].ino))) {
-			DBG(1, "Bad dentry 0x%x with invalid NID/ino 0x%x",
-			    i, le32_to_cpu(dentry[i].ino));
+			ASSERT_MSG("Bad dentry 0x%x with invalid NID/ino 0x%x",
+				    i, le32_to_cpu(dentry[i].ino));
 			if (config.fix_on) {
 				FIX_MSG("Clear bad dentry 0x%x with bad ino 0x%x",
 					i, le32_to_cpu(dentry[i].ino));
 				clear_bit(i, bitmap);
-				i++;
 				fixed = 1;
-				continue;
 			}
+			i++;
+			continue;
 		}
+
 		ftype = dentry[i].file_type;
-		if ((ftype <= F2FS_FT_UNKNOWN || ftype > F2FS_FT_LAST_FILE_TYPE) && config.fix_on) {
-			DBG(1, "Bad dentry 0x%x with unexpected ftype 0x%x",
-			    i, ftype);
+		if ((ftype <= F2FS_FT_UNKNOWN || ftype > F2FS_FT_LAST_FILE_TYPE)) {
+			ASSERT_MSG("Bad dentry 0x%x with unexpected ftype 0x%x", i, ftype);
 			if (config.fix_on) {
 				FIX_MSG("Clear bad dentry 0x%x with bad ftype 0x%x",
 					i, ftype);
 				clear_bit(i, bitmap);
-				i++;
 				fixed = 1;
-				continue;
 			}
+			i++;
+			continue;
 		}
+
 		name_len = le16_to_cpu(dentry[i].name_len);
+
+		if (name_len == 0) {
+			ASSERT_MSG("Bad dentry 0x%x with zero name_len", i);
+			if (config.fix_on) {
+				FIX_MSG("Clear bad dentry 0x%x", i);
+				clear_bit(i, bitmap);
+				fixed = 1;
+			}
+			i++;
+			continue;
+		}
+
 		name = calloc(name_len + 1, 1);
 		memcpy(name, filenames[i], name_len);
 		hash_code = f2fs_dentry_hash((const unsigned char *)name,
-- 
2.1.1


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