diff --git a/debugfs/jfs_user.h b/debugfs/jfs_user.h
index 3070cd55..66756fc7 100644
--- a/debugfs/jfs_user.h
+++ b/debugfs/jfs_user.h
@@ -5,4 +5,25 @@ typedef unsigned short kdev_t;
 
 #include <ext2fs/kernel-jbd.h>
 
+#define JSB_HAS_INCOMPAT_FEATURE(jsb, mask)				\
+	((jsb)->s_header.h_blocktype == ext2fs_cpu_to_be32(JFS_SUPERBLOCK_V2) &&	\
+	 ((jsb)->s_feature_incompat & ext2fs_cpu_to_be32((mask))))
+static inline size_t journal_super_tag_bytes(journal_superblock_t *jsb)
+{
+	size_t sz;
+
+	if (JSB_HAS_INCOMPAT_FEATURE(jsb, JFS_FEATURE_INCOMPAT_CSUM_V3))
+		return sizeof(journal_block_tag3_t);
+
+	sz = sizeof(journal_block_tag_t);
+
+	if (JSB_HAS_INCOMPAT_FEATURE(jsb, JFS_FEATURE_INCOMPAT_CSUM_V2))
+		sz += sizeof(__u16);
+
+	if (JSB_HAS_INCOMPAT_FEATURE(jsb, JFS_FEATURE_INCOMPAT_64BIT))
+		return sz;
+
+	return sz - sizeof(__u32);
+}
+
 #endif /* _JFS_USER_H */
diff --git a/debugfs/logdump.c b/debugfs/logdump.c
index 9f9594f1..70a7c363 100644
--- a/debugfs/logdump.c
+++ b/debugfs/logdump.c
@@ -476,19 +476,21 @@ static void dump_descriptor_block(FILE *out_file,
 				  unsigned int *blockp, int blocksize,
 				  tid_t transaction)
 {
-	int			offset, tag_size = JBD_TAG_SIZE32;
+	int			offset, tag_size, csum_size = 0;
 	char			*tagp;
 	journal_block_tag_t	*tag;
 	unsigned int		blocknr;
 	__u32			tag_block;
 	__u32			tag_flags;
 
-	if (be32_to_cpu(jsb->s_feature_incompat) & JFS_FEATURE_INCOMPAT_64BIT)
-		tag_size = JBD_TAG_SIZE64;
-
+	tag_size = journal_super_tag_bytes(jsb);
 	offset = sizeof(journal_header_t);
 	blocknr = *blockp;
 
+	if (JSB_HAS_INCOMPAT_FEATURE(jsb, JFS_FEATURE_INCOMPAT_CSUM_V3) ||
+	    JSB_HAS_INCOMPAT_FEATURE(jsb, JFS_FEATURE_INCOMPAT_CSUM_V2))
+		csum_size = sizeof(struct journal_block_tail);
+
 	if (dump_all)
 		fprintf(out_file, "Dumping descriptor block, sequence %u, at "
 			"block %u:\n", transaction, blocknr);
@@ -505,7 +507,7 @@ static void dump_descriptor_block(FILE *out_file,
 
 		/* ... and if we have gone too far, then we've reached the
 		   end of this block. */
-		if (offset > blocksize)
+		if (offset > blocksize - csum_size)
 			break;
 
 		tag_block = be32_to_cpu(tag->t_blocknr);
diff --git a/e2fsck/journal.c b/e2fsck/journal.c
index 533b1d6f..a19d40b6 100644
--- a/e2fsck/journal.c
+++ b/e2fsck/journal.c
@@ -44,7 +44,7 @@ static int bh_count = 0;
 static int e2fsck_journal_verify_csum_type(journal_t *j,
 					   journal_superblock_t *jsb)
 {
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 1;
 
 	return jsb->s_checksum_type == JBD2_CRC32C_CHKSUM;
@@ -68,7 +68,7 @@ static int e2fsck_journal_sb_csum_verify(journal_t *j,
 {
 	__u32 provided, calculated;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 1;
 
 	provided = ext2fs_be32_to_cpu(jsb->s_checksum);
@@ -82,7 +82,7 @@ static errcode_t e2fsck_journal_sb_csum_set(journal_t *j,
 {
 	__u32 crc;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 0;
 
 	crc = e2fsck_journal_sb_csum(jsb);
@@ -623,8 +623,12 @@ static errcode_t e2fsck_journal_load(journal_t *journal)
 	if (JFS_HAS_RO_COMPAT_FEATURE(journal, ~JFS_KNOWN_ROCOMPAT_FEATURES))
 		return EXT2_ET_RO_UNSUPP_FEATURE;
 
-	/* Checksum v1 and v2 are mutually exclusive features. */
+	/* Checksum v1-3 are mutually exclusive features. */
 	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2) &&
+	    JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V3))
+		return EXT2_ET_CORRUPT_SUPERBLOCK;
+
+	if (journal_has_csum_v2or3(journal) &&
 	    JFS_HAS_COMPAT_FEATURE(journal, JFS_FEATURE_COMPAT_CHECKSUM))
 		return EXT2_ET_CORRUPT_SUPERBLOCK;
 
@@ -632,7 +636,7 @@ static errcode_t e2fsck_journal_load(journal_t *journal)
 	    !e2fsck_journal_sb_csum_verify(journal, jsb))
 		return EXT2_ET_CORRUPT_SUPERBLOCK;
 
-	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (journal_has_csum_v2or3(journal))
 		journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
 						   sizeof(jsb->s_uuid));
 
diff --git a/e2fsck/recovery.c b/e2fsck/recovery.c
index dae72398..3dc7c06c 100644
--- a/e2fsck/recovery.c
+++ b/e2fsck/recovery.c
@@ -181,7 +181,7 @@ static int jbd2_descr_block_csum_verify(journal_t *j,
 	__u32 provided;
 	__u32 calculated;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 1;
 
 	tail = (struct journal_block_tail *)(buf + j->j_blocksize -
@@ -205,7 +205,7 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
 	int			nr = 0, size = journal->j_blocksize;
 	int			tag_bytes = journal_tag_bytes(journal);
 
-	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (journal_has_csum_v2or3(journal))
 		size -= sizeof(struct journal_block_tail);
 
 	tagp = &bh->b_data[sizeof(journal_header_t)];
@@ -338,10 +338,11 @@ int journal_skip_recovery(journal_t *journal)
 	return err;
 }
 
-static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
+static inline unsigned long long read_tag_block(journal_t *journal,
+						journal_block_tag_t *tag)
 {
 	unsigned long long block = ext2fs_be32_to_cpu(tag->t_blocknr);
-	if (tag_bytes > JFS_TAG_SIZE32)
+	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
 		block |= (u64)ext2fs_be32_to_cpu(tag->t_blocknr_high) << 32;
 	return block;
 }
@@ -384,7 +385,7 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 	__u32 provided;
 	__u32 calculated;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 1;
 
 	h = buf;
@@ -399,16 +400,20 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
 				      void *buf, __u32 sequence)
 {
+	journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
 	__u32 csum32;
 	__u32 seq;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 1;
 
 	seq = ext2fs_cpu_to_be32(sequence);
 	csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
 	csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
 
+	if (JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V3))
+		return tag3->t_checksum == ext2fs_cpu_to_be32(csum32);
+
 	return tag->t_checksum == ext2fs_cpu_to_be16(csum32);
 }
 
@@ -513,8 +518,7 @@ static int do_one_pass(journal_t *journal,
 		switch(blocktype) {
 		case JFS_DESCRIPTOR_BLOCK:
 			/* Verify checksum first */
-			if (JFS_HAS_INCOMPAT_FEATURE(journal,
-					JFS_FEATURE_INCOMPAT_CSUM_V2))
+			if (journal_has_csum_v2or3(journal))
 				descr_csum_size =
 					sizeof(struct journal_block_tail);
 			if (descr_csum_size > 0 &&
@@ -575,7 +579,7 @@ static int do_one_pass(journal_t *journal,
 					unsigned long long blocknr;
 
 					J_ASSERT(obh != NULL);
-					blocknr = read_tag_block(tag_bytes,
+					blocknr = read_tag_block(journal,
 								 tag);
 
 					/* If the block has been
@@ -814,7 +818,7 @@ static int jbd2_revoke_block_csum_verify(journal_t *j,
 	__u32 provided;
 	__u32 calculated;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return 1;
 
 	tail = (struct journal_revoke_tail *)(buf + j->j_blocksize -
diff --git a/e2fsck/revoke.c b/e2fsck/revoke.c
index 383164ea..b4c3f5f4 100644
--- a/e2fsck/revoke.c
+++ b/e2fsck/revoke.c
@@ -597,7 +597,7 @@ static void write_one_revoke_record(journal_t *journal,
 	offset = *offsetp;
 
 	/* Do we need to leave space at the end for a checksum? */
-	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (journal_has_csum_v2or3(journal))
 		csum_size = sizeof(struct journal_revoke_tail);
 
 	/* Make sure we have a descriptor with space left for the record */
@@ -644,7 +644,7 @@ static void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
 	struct journal_revoke_tail *tail;
 	__u32 csum;
 
-	if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if (!journal_has_csum_v2or3(j))
 		return;
 
 	tail = (struct journal_revoke_tail *)(bh->b_data + j->j_blocksize -
diff --git a/lib/e2p/feature.c b/lib/e2p/feature.c
index d0e29b89..6e53cfe8 100644
--- a/lib/e2p/feature.c
+++ b/lib/e2p/feature.c
@@ -112,6 +112,8 @@ static struct feature jrnl_feature_list[] = {
                        "journal_async_commit" },
        {       E2P_FEATURE_INCOMPAT, JFS_FEATURE_INCOMPAT_CSUM_V2,
                        "journal_checksum_v2" },
+       {       E2P_FEATURE_INCOMPAT, JFS_FEATURE_INCOMPAT_CSUM_V3,
+                       "journal_checksum_v3" },
        {       0, 0, 0 },
 };
 
diff --git a/lib/ext2fs/kernel-jbd.h b/lib/ext2fs/kernel-jbd.h
index 407f4a56..40204299 100644
--- a/lib/ext2fs/kernel-jbd.h
+++ b/lib/ext2fs/kernel-jbd.h
@@ -131,7 +131,11 @@ typedef struct journal_header_s
  * journal_block_tag (in the descriptor).  The other h_chksum* fields are
  * not used.
  *
- * Checksum v1 and v2 are mutually exclusive features.
+ * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
+ * journal_block_tag3_t to store a full 32-bit checksum.  Everything else
+ * is the same as v2.
+ *
+ * Checksum v1, v2, and v3 are mutually exclusive features.
  */
 struct commit_header {
 	__u32		h_magic;
@@ -148,6 +152,14 @@ struct commit_header {
 /*
  * The block tag: used to describe a single buffer in the journal
  */
+typedef struct journal_block_tag3_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_tag3_t;
+
 typedef struct journal_block_tag_s
 {
 	__u32		t_blocknr;	/* The on-disk block number */
@@ -156,9 +168,6 @@ typedef struct journal_block_tag_s
 	__u32		t_blocknr_high; /* most-significant high 32bits. */
 } journal_block_tag_t;
 
-#define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t))
-#define JBD_TAG_SIZE32 (8)
-
 /* Tail of descriptor block, for checksumming */
 struct journal_block_tail {
 	__u32		t_checksum;
@@ -257,6 +266,7 @@ typedef struct journal_superblock_s
 #define JFS_FEATURE_INCOMPAT_64BIT		0x00000002
 #define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT	0x00000004
 #define JFS_FEATURE_INCOMPAT_CSUM_V2		0x00000008
+#define JFS_FEATURE_INCOMPAT_CSUM_V3		0x00000010
 
 /* Features known to this kernel version: */
 #define JFS_KNOWN_COMPAT_FEATURES	0
@@ -264,7 +274,8 @@ typedef struct journal_superblock_s
 #define JFS_KNOWN_INCOMPAT_FEATURES	(JFS_FEATURE_INCOMPAT_REVOKE|\
 					 JFS_FEATURE_INCOMPAT_ASYNC_COMMIT|\
 					 JFS_FEATURE_INCOMPAT_64BIT|\
-					 JFS_FEATURE_INCOMPAT_CSUM_V2)
+					 JFS_FEATURE_INCOMPAT_CSUM_V2|\
+					 JFS_FEATURE_INCOMPAT_CSUM_V3)
 
 #if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
 #ifdef E2FSCK_INCLUDE_INLINE_FUNCS
@@ -290,16 +301,29 @@ typedef struct journal_superblock_s
  */
 _INLINE_ size_t journal_tag_bytes(journal_t *journal)
 {
-	journal_block_tag_t tag;
-	size_t x = 0;
+	size_t sz;
+
+	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V3))
+		return sizeof(journal_block_tag3_t);
+
+	sz = sizeof(journal_block_tag_t);
 
 	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
-		x += sizeof(tag.t_checksum);
+		sz += sizeof(__u16);
 
 	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
-		return x + JBD_TAG_SIZE64;
-	else
-		return x + JBD_TAG_SIZE32;
+		return sz;
+
+	return sz - sizeof(__u32);
+}
+
+_INLINE_ int journal_has_csum_v2or3(journal_t *journal)
+{
+	if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2) ||
+	    JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V3))
+		return 1;
+
+	return 0;
 }
 #undef _INLINE_
 #endif
diff --git a/misc/dumpe2fs.c b/misc/dumpe2fs.c
index a1c5ba26..25dce9c5 100644
--- a/misc/dumpe2fs.c
+++ b/misc/dumpe2fs.c
@@ -415,8 +415,10 @@ static void print_inline_journal_information(ext2_filsys fs)
 	if (jsb->s_feature_compat &
 	    ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_CHECKSUM))
 		printf("%s", _("Journal checksum type:    crc32\n"));
-	if (jsb->s_feature_incompat &
-	    ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if ((jsb->s_feature_incompat &
+	     ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_CSUM_V3)) ||
+	    (jsb->s_feature_incompat &
+	     ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_CSUM_V2)))
 		printf(_("Journal checksum type:    %s\n"
 			 "Journal checksum:         0x%08x\n"),
 		       journal_checksum_type_str(jsb->s_checksum_type),
@@ -454,8 +456,10 @@ static void print_journal_information(ext2_filsys fs)
 	if (jsb->s_feature_compat &
 	    ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_CHECKSUM))
 		printf("%s", _("Journal checksum type:    crc32\n"));
-	if (jsb->s_feature_incompat &
-	    ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_CSUM_V2))
+	if ((jsb->s_feature_incompat &
+	     ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_CSUM_V3)) ||
+	    (jsb->s_feature_incompat &
+	     ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_CSUM_V2)))
 		printf(_("Journal checksum type:    %s\n"
 			 "Journal checksum:         0x%08x\n"),
 		       journal_checksum_type_str(jsb->s_checksum_type),