[48/50] e2fsck: Verify data block checksums when recovering journal

diff --git a/e2fsck/jfs_user.h b/e2fsck/jfs_user.h
index 9e33306..4baba54 100644
--- a/e2fsck/jfs_user.h
+++ b/e2fsck/jfs_user.h
@@ -104,17 +104,6 @@  _INLINE_ void do_cache_destroy(lkmem_cache_t *cache)
 	free(cache);
 }
 
-/*
- * helper functions to deal with 32 or 64bit block numbers.
- */
-_INLINE_ size_t journal_tag_bytes(journal_t *journal)
-{
-	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
-		return JBD_TAG_SIZE64;
-	else
-		return JBD_TAG_SIZE32;
-}
-
 #undef _INLINE_
 #endif
 
diff --git a/e2fsck/recovery.c b/e2fsck/recovery.c
index beafacc..5cda381 100644
--- a/e2fsck/recovery.c
+++ b/e2fsck/recovery.c
@@ -395,6 +395,25 @@  static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 	return provided == calculated;
 }
 
+static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
+				      void *buf, __u32 sequence)
+{
+	__u32 provided, calculated;
+
+	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+		return 1;
+
+	sequence = ext2fs_cpu_to_be32(sequence);
+	calculated = ext2fs_crc32c_le(~0, j->j_superblock->s_uuid,
+				      sizeof(j->j_superblock->s_uuid));
+	calculated = ext2fs_crc32c_le(calculated, (__u8 *)&sequence,
+				      sizeof(sequence));
+	calculated = ext2fs_crc32c_le(calculated, buf, j->j_blocksize);
+	provided = ext2fs_be32_to_cpu(tag->t_checksum);
+
+	return provided == ext2fs_cpu_to_be32(calculated);
+}
+
 static int do_one_pass(journal_t *journal,
 			struct recovery_info *info, enum passtype pass)
 {
@@ -575,6 +594,19 @@  static int do_one_pass(journal_t *journal,
 						goto skip_write;
 					}
 
+					/* Look for block corruption */
+					if (!jbd2_block_tag_csum_verify(
+						journal, tag, obh->b_data,
+						be32_to_cpu(tmp->h_sequence))) {
+						brelse(obh);
+						success = -EIO;
+						printk(KERN_ERR "JBD: Invalid "
+						       "checksum recovering "
+						       "block %ld in log\n",
+						       blocknr);
+						continue;
+					}
+
 					/* Find a buffer for the new
 					 * data being restored */
 					nbh = __getblk(journal->j_fs_dev,
diff --git a/lib/ext2fs/kernel-jbd.h b/lib/ext2fs/kernel-jbd.h
index c650582..a86150c 100644
--- a/lib/ext2fs/kernel-jbd.h
+++ b/lib/ext2fs/kernel-jbd.h
@@ -153,6 +153,7 @@  typedef struct journal_block_tag_s
 	__u32		t_blocknr;	/* The on-disk block number */
 	__u32		t_flags;	/* See below */
 	__u32		t_blocknr_high; /* most-significant high 32bits. */
+	__u32		t_checksum;	/* crc32c(uuid+seq+block) */
 } journal_block_tag_t;
 
 #define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t))
@@ -261,6 +262,36 @@  typedef struct journal_superblock_s
 					 JFS_FEATURE_INCOMPAT_64BIT|\
 					 JFS_FEATURE_INCOMPAT_CSUM_V2)
 
+#if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
+#ifdef E2FSCK_INCLUDE_INLINE_FUNCS
+#define _INLINE_ extern
+#else
+#ifdef __GNUC__
+#define _INLINE_ extern __inline__
+#else				/* For Watcom C */
+#define _INLINE_ extern inline
+#endif
+#endif
+
+/*
+ * helper functions to deal with 32 or 64bit block numbers.
+ */
+_INLINE_ size_t journal_tag_bytes(journal_t *journal)
+{
+	journal_block_tag_t tag;
+	size_t x = 0;
+
+	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
+		x += sizeof(tag.t_checksum);
+
+	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
+		return x + JBD_TAG_SIZE64;
+	else
+		return x + JBD_TAG_SIZE32;
+}
+#undef _INLINE_
+#endif
+
 #ifdef __KERNEL__
 
 #include <linux/fs.h>