[PATCH 5/7] xfs: encapsulate bbcount validity checking

[Alex Elder]

This replaces is a duplicated block of essentially identical code
in three spots with a call to a common helper routine.

Signed-off-by: Alex Elder <aelder at sgi.com>

---
 fs/xfs/xfs_log_recover.c |   44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

Index: b/fs/xfs/xfs_log_recover.c
===================================================================
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -63,17 +63,39 @@ STATIC void	xlog_recover_check_summary(x
 /* Number of basic blocks in a log sector */
 #define xlog_sectbb(log) (1 << (log)->l_sectbb_log)
 
+/*
+ * Verify the given count of basic blocks is valid number of blocks
+ * to specify for an operation involving the given XFS log buffer.
+ * If not, report the error.
+ *
+ * Returns 1 if the count is valid, 0 otherwise.
+ */
+
+#define xlog_buf_bbcount_valid(log, bbcount) \
+		_xlog_buf_bbcount_valid(log, bbcount, __func__)
+inline static int
+_xlog_buf_bbcount_valid(
+	xlog_t		*log,
+	int		bbcount,
+	const void	*function)
+{
+	if (bbcount > 0 && bbcount <= log->l_logBBsize)
+	    	return 1;
+
+	xlog_warn("XFS: Invalid block length (0x%x) given for buffer",
+		bbcount);
+	XFS_ERROR_REPORT(function, XFS_ERRLEVEL_HIGH, log->l_mp);
+
+	return 0;	/* Basic block count out of log's range */
+}
+
 STATIC xfs_buf_t *
 xlog_get_bp(
 	xlog_t		*log,
 	int		nbblks)
 {
-	if (nbblks <= 0 || nbblks > log->l_logBBsize) {
-		xlog_warn("XFS: Invalid block length (0x%x) given for buffer", nbblks);
-		XFS_ERROR_REPORT("xlog_get_bp(1)",
-				 XFS_ERRLEVEL_HIGH, log->l_mp);
+	if (!xlog_buf_bbcount_valid(log, nbblks))
 		return NULL;
-	}
 
 	if (log->l_sectbb_log) {
 		if (nbblks > 1)
@@ -121,12 +143,8 @@ xlog_bread_noalign(
 {
 	int		error;
 
-	if (nbblks <= 0 || nbblks > log->l_logBBsize) {
-		xlog_warn("XFS: Invalid block length (0x%x) given for buffer", nbblks);
-		XFS_ERROR_REPORT("xlog_bread(1)",
-				 XFS_ERRLEVEL_HIGH, log->l_mp);
+	if (!xlog_buf_bbcount_valid(log, nbblks))
 		return EFSCORRUPTED;
-	}
 
 	if (log->l_sectbb_log) {
 		blk_no = round_down(blk_no, xlog_sectbb(log));
@@ -183,12 +201,8 @@ xlog_bwrite(
 {
 	int		error;
 
-	if (nbblks <= 0 || nbblks > log->l_logBBsize) {
-		xlog_warn("XFS: Invalid block length (0x%x) given for buffer", nbblks);
-		XFS_ERROR_REPORT("xlog_bwrite(1)",
-				 XFS_ERRLEVEL_HIGH, log->l_mp);
+	if (!xlog_buf_bbcount_valid(log, nbblks))
 		return EFSCORRUPTED;
-	}
 
 	if (log->l_sectbb_log) {
 		blk_no = round_down(blk_no, xlog_sectbb(log));