jbd2: unify revoke and tag block checksum handling

Revoke and tag descriptor blocks are just different kinds of descriptor
blocks and thus have checksum in the same place. Unify computation and
checking of checksums for these.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

5 files changed, 25 insertions, 66 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index cf221f3d955a..ae832cd44dd8 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -317,22 +317,6 @@ static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
 		tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
 }
 
-static void jbd2_descr_block_csum_set(journal_t *j,
-				      struct buffer_head *bh)
-{
-	struct jbd2_journal_block_tail *tail;
-	__u32 csum;
-
-	if (!jbd2_journal_has_csum_v2or3(j))
-		return;
-
-	tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
-			sizeof(struct jbd2_journal_block_tail));
-	tail->t_checksum = 0;
-	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
-	tail->t_checksum = cpu_to_be32(csum);
-}
-
 static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
 				    struct buffer_head *bh, __u32 sequence)
 {
@@ -714,7 +698,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
 			tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
 
-			jbd2_descr_block_csum_set(journal, descriptor);
+			jbd2_descriptor_block_csum_set(journal, descriptor);
 start_journal_io:
 			for (i = 0; i < bufs; i++) {
 				struct buffer_head *bh = wbuf[i];
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 28d05bd9a588..defa962a8e15 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -834,6 +834,21 @@ jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type)
 	return bh;
 }
 
+void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh)
+{
+	struct jbd2_journal_block_tail *tail;
+	__u32 csum;
+
+	if (!jbd2_journal_has_csum_v2or3(j))
+		return;
+
+	tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
+			sizeof(struct jbd2_journal_block_tail));
+	tail->t_checksum = 0;
+	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
+	tail->t_checksum = cpu_to_be32(csum);
+}
+
 /*
  * Return tid of the oldest transaction in the journal and block in the journal
  * where the transaction starts.
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 7f277e49fe88..08a456b96e4e 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -174,8 +174,7 @@ static int jread(struct buffer_head **bhp, journal_t *journal,
 	return 0;
 }
 
-static int jbd2_descr_block_csum_verify(journal_t *j,
-					void *buf)
+static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf)
 {
 	struct jbd2_journal_block_tail *tail;
 	__be32 provided;
@@ -522,8 +521,8 @@ static int do_one_pass(journal_t *journal,
 				descr_csum_size =
 					sizeof(struct jbd2_journal_block_tail);
 			if (descr_csum_size > 0 &&
-			    !jbd2_descr_block_csum_verify(journal,
-							  bh->b_data)) {
+			    !jbd2_descriptor_block_csum_verify(journal,
+							       bh->b_data)) {
 				printk(KERN_ERR "JBD2: Invalid checksum "
 				       "recovering block %lu in log\n",
 				       next_log_block);
@@ -811,26 +810,6 @@ static int do_one_pass(journal_t *journal,
 	return err;
 }
 
-static int jbd2_revoke_block_csum_verify(journal_t *j,
-					 void *buf)
-{
-	struct jbd2_journal_revoke_tail *tail;
-	__be32 provided;
-	__u32 calculated;
-
-	if (!jbd2_journal_has_csum_v2or3(j))
-		return 1;
-
-	tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
-			sizeof(struct jbd2_journal_revoke_tail));
-	provided = tail->r_checksum;
-	tail->r_checksum = 0;
-	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
-	tail->r_checksum = provided;
-
-	return provided == cpu_to_be32(calculated);
-}
-
 /* Scan a revoke record, marking all blocks mentioned as revoked. */
 
 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
@@ -846,11 +825,11 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
 	offset = sizeof(jbd2_journal_revoke_header_t);
 	rcount = be32_to_cpu(header->r_count);
 
-	if (!jbd2_revoke_block_csum_verify(journal, header))
+	if (!jbd2_descriptor_block_csum_verify(journal, header))
 		return -EFSBADCRC;
 
 	if (jbd2_journal_has_csum_v2or3(journal))
-		csum_size = sizeof(struct jbd2_journal_revoke_tail);
+		csum_size = sizeof(struct jbd2_journal_block_tail);
 	if (rcount > journal->j_blocksize - csum_size)
 		return -EINVAL;
 	max = rcount;
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index d1ebb1d41d17..91171dc352cb 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -583,7 +583,7 @@ static void write_one_revoke_record(transaction_t *transaction,
 
 	/* Do we need to leave space at the end for a checksum? */
 	if (jbd2_journal_has_csum_v2or3(journal))
-		csum_size = sizeof(struct jbd2_journal_revoke_tail);
+		csum_size = sizeof(struct jbd2_journal_block_tail);
 
 	if (jbd2_has_feature_64bit(journal))
 		sz = 8;
@@ -623,21 +623,6 @@ static void write_one_revoke_record(transaction_t *transaction,
 	*offsetp = offset;
 }
 
-static void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
-{
-	struct jbd2_journal_revoke_tail *tail;
-	__u32 csum;
-
-	if (!jbd2_journal_has_csum_v2or3(j))
-		return;
-
-	tail = (struct jbd2_journal_revoke_tail *)(bh->b_data + j->j_blocksize -
-			sizeof(struct jbd2_journal_revoke_tail));
-	tail->r_checksum = 0;
-	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
-	tail->r_checksum = cpu_to_be32(csum);
-}
-
 /*
  * Flush a revoke descriptor out to the journal.  If we are aborting,
  * this is a noop; otherwise we are generating a buffer which needs to
@@ -658,7 +643,7 @@ static void flush_descriptor(journal_t *journal,
 
 	header = (jbd2_journal_revoke_header_t *)descriptor->b_data;
 	header->r_count = cpu_to_be32(offset);
-	jbd2_revoke_csum_set(journal, descriptor);
+	jbd2_descriptor_block_csum_set(journal, descriptor);
 
 	set_buffer_jwrite(descriptor);
 	BUFFER_TRACE(descriptor, "write");
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 3649cb8d3a41..fd1083c46c61 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -200,7 +200,7 @@ typedef struct journal_block_tag_s
 	__be32		t_blocknr_high; /* most-significant high 32bits. */
 } journal_block_tag_t;
 
-/* Tail of descriptor block, for checksumming */
+/* Tail of descriptor or revoke block, for checksumming */
 struct jbd2_journal_block_tail {
 	__be32		t_checksum;	/* crc32c(uuid+descr_block) */
 };
@@ -215,11 +215,6 @@ typedef struct jbd2_journal_revoke_header_s
 	__be32		 r_count;	/* Count of bytes used in the block */
 } jbd2_journal_revoke_header_t;
 
-/* Tail of revoke block, for checksumming */
-struct jbd2_journal_revoke_tail {
-	__be32		r_checksum;	/* crc32c(uuid+revoke_block) */
-};
-
 /* Definitions for the journal tag flags word: */
 #define JBD2_FLAG_ESCAPE		1	/* on-disk block is escaped */
 #define JBD2_FLAG_SAME_UUID	2	/* block has same uuid as previous */
@@ -1138,6 +1133,7 @@ static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
 
 /* Log buffer allocation */
 struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
+void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *);
 int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
 			      unsigned long *block);