xfs: record log sector size rather than log2(that)

Change struct log so it keeps track of the size (in basic blocks) of
a log sector in l_sectBBsize rather than the log-base-2 of that
value (previously, l_sectbb_log).  The name was chosen for
consistency with the other fields in the structure that represent
a number of basic blocks.

(Updated so that a variable used in computing and verifying a log's
sector size is named "log2_size".  Also added the "BB" to the
structure field name, based on feedback from Eric Sandeen.  Also
dropped some superfluous parentheses.)

Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>

1 files changed, 18 insertions, 15 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 77593c2ead4..36e09e362f7 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1039,6 +1039,7 @@ xlog_alloc_log(xfs_mount_t	*mp,
 	int			i;
 	int			iclogsize;
 	int			error = ENOMEM;
+	uint			log2_size = 0;
 
 	log = kmem_zalloc(sizeof(xlog_t), KM_MAYFAIL);
 	if (!log) {
@@ -1064,29 +1065,31 @@ xlog_alloc_log(xfs_mount_t	*mp,
 
 	error = EFSCORRUPTED;
 	if (xfs_sb_version_hassector(&mp->m_sb)) {
-		log->l_sectbb_log = mp->m_sb.sb_logsectlog - BBSHIFT;
-		if (log->l_sectbb_log < 0 ||
-		    log->l_sectbb_log > mp->m_sectbb_log) {
-			xlog_warn("XFS: Log sector size (0x%x) out of range.",
-						log->l_sectbb_log);
+	        log2_size = mp->m_sb.sb_logsectlog;
+		if (log2_size < BBSHIFT) {
+			xlog_warn("XFS: Log sector size too small "
+				"(0x%x < 0x%x)", log2_size, BBSHIFT);
 			goto out_free_log;
 		}
 
-		/* for larger sector sizes, must have v2 or external log */
-		if (log->l_sectbb_log != 0 &&
-		    (log->l_logBBstart != 0 &&
-		     !xfs_sb_version_haslogv2(&mp->m_sb))) {
-			xlog_warn("XFS: log sector size (0x%x) invalid "
-				  "for configuration.", log->l_sectbb_log);
+	        log2_size -= BBSHIFT;
+		if (log2_size > mp->m_sectbb_log) {
+			xlog_warn("XFS: Log sector size too large "
+				"(0x%x > 0x%x)", log2_size, mp->m_sectbb_log);
 			goto out_free_log;
 		}
-		if (mp->m_sb.sb_logsectlog < BBSHIFT) {
-			xlog_warn("XFS: Log sector log (0x%x) too small.",
-						mp->m_sb.sb_logsectlog);
+
+		/* for larger sector sizes, must have v2 or external log */
+		if (log2_size && log->l_logBBstart > 0 &&
+			    !xfs_sb_version_haslogv2(&mp->m_sb)) {
+
+			xlog_warn("XFS: log sector size (0x%x) invalid "
+				  "for configuration.", log2_size);
 			goto out_free_log;
 		}
 	}
-	log->l_sectbb_mask = (1 << log->l_sectbb_log) - 1;
+	log->l_sectBBsize = 1 << log2_size;
+	log->l_sectbb_mask = log->l_sectBBsize - 1;
 
 	xlog_get_iclog_buffer_size(mp, log);