xfs: kill off l_sectbb_mask

There remains only one user of the l_sectbb_mask field in the log
structure.  Just kill it off and compute the mask where needed from
the power-of-2 sector size.

(Only update from last post is to accomodate the changes in the
previous patch in the series.)

Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

3 files changed, 10 insertions, 9 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 36e09e362f7f..3038dd52c72a 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1089,7 +1089,6 @@ xlog_alloc_log(xfs_mount_t	*mp,
                 }
         }
         log->l_sectBBsize = 1 << log2_size;
-        log->l_sectbb_mask = log->l_sectBBsize - 1;
 
         xlog_get_iclog_buffer_size(mp, log);
 
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 56f221d7bf61..9cf695154451 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -396,9 +396,7 @@ typedef struct log {
         struct xfs_buf_cancel   **l_buf_cancel_table;
         int                     l_iclog_hsize;  /* size of iclog header */
         int                     l_iclog_heads;  /* # of iclog header sectors */
-        uint                    l_sectBBsize;   /* sector size in BBs */
-        uint                    l_sectbb_mask;  /* sector size (in BBs)
-                                                 * alignment mask */
+        uint                    l_sectBBsize;   /* sector size in BBs (2^n) */
         int                     l_iclog_size;   /* size of log in bytes */
         int                     l_iclog_size_log; /* log power size of log */
         int                     l_iclog_bufs;   /* number of iclog buffers */
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index f1220ec1896f..0de08e366315 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -121,6 +121,10 @@ xlog_put_bp(
         xfs_buf_free(bp);
 }
 
+/*
+ * Return the address of the start of the given block number's data
+ * in a log buffer.  The buffer covers a log sector-aligned region.
+ */
 STATIC xfs_caddr_t
 xlog_align(
         xlog_t          *log,
@@ -128,14 +132,14 @@ xlog_align(
         int             nbblks,
         xfs_buf_t       *bp)
 {
+        xfs_daddr_t     offset;
         xfs_caddr_t     ptr;
 
-        if (log->l_sectBBsize == 1)
-                return XFS_BUF_PTR(bp);
+        offset = blk_no & ((xfs_daddr_t) log->l_sectBBsize - 1);
+        ptr = XFS_BUF_PTR(bp) + BBTOB(offset);
+
+        ASSERT(ptr + BBTOB(nbblks) <= XFS_BUF_PTR(bp) + XFS_BUF_SIZE(bp));
 
-        ptr = XFS_BUF_PTR(bp) + BBTOB((int)blk_no & log->l_sectbb_mask);
-        ASSERT(XFS_BUF_SIZE(bp) >=
-                BBTOB(nbblks + (blk_no & log->l_sectbb_mask)));
         return ptr;
 }