[PATCH v2 2/2] xfs: clean up calculation of LR header blocks

[Gao Xiang <hsiangkao@xxxxxxxxxx>]

Let's use DIV_ROUND_UP() to calculate log record header
blocks as what did in xlog_get_iclog_buffer_size() and
wrap up common helpers for log recovery.

Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxx>
---
v1: https://lore.kernel.org/r/20200902140923.24392-1-hsiangkao@xxxxxxxxxx

changes since v1:
 - add another helper xlog_logrec_hblks() for the cases with
   xfs_sb_version_haslogv2(), and use xlog_logrecv2_hblks()
   for the case of xlog_do_recovery_pass() since it has more
   complex logic other than just calculate hblks...

 fs/xfs/xfs_log.c         |  4 +--
 fs/xfs/xfs_log_recover.c | 53 ++++++++++++++++------------------------
 2 files changed, 22 insertions(+), 35 deletions(-)

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index ad0c69ee8947..7a4ba408a3a2 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1604,9 +1604,7 @@ xlog_cksum(
 		int		i;
 		int		xheads;
 
-		xheads = size / XLOG_HEADER_CYCLE_SIZE;
-		if (size % XLOG_HEADER_CYCLE_SIZE)
-			xheads++;
+		xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
 
 		for (i = 1; i < xheads; i++) {
 			crc = crc32c(crc, &xhdr[i].hic_xheader,
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 28d952794bfa..c6163065f6e0 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -397,6 +397,23 @@ xlog_find_verify_cycle(
 	return error;
 }
 
+static inline int xlog_logrecv2_hblks(struct xlog_rec_header *rh)
+{
+	int	h_size = be32_to_cpu(rh->h_size);
+
+	if ((be32_to_cpu(rh->h_version) & XLOG_VERSION_2) &&
+	    h_size > XLOG_HEADER_CYCLE_SIZE)
+		return DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE);
+	return 1;
+}
+
+static inline int xlog_logrec_hblks(struct xlog *log, xlog_rec_header_t *rh)
+{
+	if (!xfs_sb_version_haslogv2(&log->l_mp->m_sb))
+		return 1;
+	return xlog_logrecv2_hblks(rh);
+}
+
 /*
  * Potentially backup over partial log record write.
  *
@@ -489,15 +506,7 @@ xlog_find_verify_log_record(
 	 * reset last_blk.  Only when last_blk points in the middle of a log
 	 * record do we update last_blk.
 	 */
-	if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
-		uint	h_size = be32_to_cpu(head->h_size);
-
-		xhdrs = h_size / XLOG_HEADER_CYCLE_SIZE;
-		if (h_size % XLOG_HEADER_CYCLE_SIZE)
-			xhdrs++;
-	} else {
-		xhdrs = 1;
-	}
+	xhdrs = xlog_logrec_hblks(log, head);
 
 	if (*last_blk - i + extra_bblks !=
 	    BTOBB(be32_to_cpu(head->h_len)) + xhdrs)
@@ -1184,22 +1193,7 @@ xlog_check_unmount_rec(
 	 * below. We won't want to clear the unmount record if there is one, so
 	 * we pass the lsn of the unmount record rather than the block after it.
 	 */
-	if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
-		int	h_size = be32_to_cpu(rhead->h_size);
-		int	h_version = be32_to_cpu(rhead->h_version);
-
-		if ((h_version & XLOG_VERSION_2) &&
-		    (h_size > XLOG_HEADER_CYCLE_SIZE)) {
-			hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
-			if (h_size % XLOG_HEADER_CYCLE_SIZE)
-				hblks++;
-		} else {
-			hblks = 1;
-		}
-	} else {
-		hblks = 1;
-	}
-
+	hblks = xlog_logrec_hblks(log, rhead);
 	after_umount_blk = xlog_wrap_logbno(log,
 			rhead_blk + hblks + BTOBB(be32_to_cpu(rhead->h_len)));
 
@@ -3024,15 +3018,10 @@ xlog_do_recovery_pass(
 		if (error)
 			goto bread_err1;
 
-		if ((be32_to_cpu(rhead->h_version) & XLOG_VERSION_2) &&
-		    (h_size > XLOG_HEADER_CYCLE_SIZE)) {
-			hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
-			if (h_size % XLOG_HEADER_CYCLE_SIZE)
-				hblks++;
+		hblks = xlog_logrecv2_hblks(rhead);
+		if (hblks != 1) {
 			kmem_free(hbp);
 			hbp = xlog_alloc_buffer(log, hblks);
-		} else {
-			hblks = 1;
 		}
 	} else {
 		ASSERT(log->l_sectBBsize == 1);
-- 
2.18.1