xfs: clean up xfs_buftarg

Clean up the xfs_buftarg structure a bit:
- remove bt_bsize which is never used
- replace bt_sshift with bt_ssize; we only ever shift it back

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 9fccfb5..b664bce 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -445,7 +445,7 @@
 	numbytes = BBTOB(numblks);
 
 	/* Check for IOs smaller than the sector size / not sector aligned */
-	ASSERT(!(numbytes < (1 << btp->bt_sshift)));
+	ASSERT(!(numbytes < btp->bt_ssize));
 	ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask));
 
 	/*
@@ -1599,8 +1599,7 @@
 	unsigned int		blocksize,
 	unsigned int		sectorsize)
 {
-	btp->bt_bsize = blocksize;
-	btp->bt_sshift = ffs(sectorsize) - 1;
+	btp->bt_ssize = sectorsize;
 	btp->bt_smask = sectorsize - 1;
 
 	if (set_blocksize(btp->bt_bdev, sectorsize)) {
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 1cf21a4..4ef949a 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -93,8 +93,7 @@
 	struct block_device	*bt_bdev;
 	struct backing_dev_info	*bt_bdi;
 	struct xfs_mount	*bt_mount;
-	unsigned int		bt_bsize;
-	unsigned int		bt_sshift;
+	unsigned int		bt_ssize;
 	size_t			bt_smask;
 
 	/* LRU control structures */
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 518aa56..584e092 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1583,7 +1583,7 @@
 			XFS_IS_REALTIME_INODE(ip) ?
 			mp->m_rtdev_targp : mp->m_ddev_targp;
 
-		da.d_mem = da.d_miniosz = 1 << target->bt_sshift;
+		da.d_mem = da.d_miniosz = target->bt_ssize;
 		da.d_maxiosz = INT_MAX & ~(da.d_miniosz - 1);
 
 		if (copy_to_user(arg, &da, sizeof(da)))