xfs: encapsulate bbcount validity checking

Index: b/fs/xfs/xfs_log_recover.c
===================================================================
@@ -63,15 +63,29 @@ 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.
+ * Returns nonzero if the count is valid, 0 otherwise.
+ */
+
+inline static int
+xlog_buf_bbcount_valid(
+	xlog_t		*log,
+	int		bbcount)
+{
+	return bbcount > 0 && bbcount <= log->l_logBBsize;
+}
+
 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)) {
+		xlog_warn("XFS: Invalid block length (0x%x) given for buffer",
+			nbblks);
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_HIGH, log->l_mp);
 		return NULL;
 	}
 

@@ -121,10 +135,10 @@ 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)) {
+		xlog_warn("XFS: Invalid block length (0x%x) given for buffer",
+			nbblks);
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_HIGH, log->l_mp);
 		return EFSCORRUPTED;
 	}
 

@@ -183,10 +197,10 @@ 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)) {
+		xlog_warn("XFS: Invalid block length (0x%x) given for buffer",
+			nbblks);
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_HIGH, log->l_mp);
 		return EFSCORRUPTED;
 	}