xfs: m_maxioffset is redundant

The m_maxioffset field in the struct xfs_mount contains the same
value as the superblock s_maxbytes field. There is no need to carry
two copies of this limit around, so use the VFS superblock version.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

fs/xfs/xfs_aops.c

@@ -323,10 +323,10 @@ xfs_map_blocks(
 
 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
 	       (ip->i_df.if_flags & XFS_IFEXTENTS));
-	ASSERT(offset <= mp->m_maxioffset);
+	ASSERT(offset <= mp->m_super->s_maxbytes);
 
-	if (offset + count > mp->m_maxioffset)
-		count = mp->m_maxioffset - offset;
+	if (offset + count > mp->m_super->s_maxbytes)
+		count = mp->m_super->s_maxbytes - offset;
 	end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
 	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
@@ -1162,9 +1162,9 @@ __xfs_get_blocks(
 		lockmode = xfs_ilock_map_shared(ip);
 	}
 
-	ASSERT(offset <= mp->m_maxioffset);
-	if (offset + size > mp->m_maxioffset)
-		size = mp->m_maxioffset - offset;
+	ASSERT(offset <= mp->m_super->s_maxbytes);
+	if (offset + size > mp->m_super->s_maxbytes)
+		size = mp->m_super->s_maxbytes - offset;
 	end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
 

fs/xfs/xfs_iomap.c

@@ -416,8 +416,8 @@ xfs_iomap_write_delay(
 	 * Make sure preallocation does not create extents beyond the range we
 	 * actually support in this filesystem.
 	 */
-	if (last_fsb > XFS_B_TO_FSB(mp, mp->m_maxioffset))
-		last_fsb = XFS_B_TO_FSB(mp, mp->m_maxioffset);
+	if (last_fsb > XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes))
+		last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
 
 	ASSERT(last_fsb > offset_fsb);
 

fs/xfs/xfs_mount.c

@@ -1200,8 +1200,6 @@ xfs_mountfs(
 
 	xfs_set_maxicount(mp);
 
-	mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
-
 	error = xfs_uuid_mount(mp);
 	if (error)
 		goto out;

fs/xfs/xfs_mount.h

@@ -176,7 +176,6 @@ typedef struct xfs_mount {
 	uint			m_qflags;	/* quota status flags */
 	xfs_trans_reservations_t m_reservations;/* precomputed res values */
 	__uint64_t		m_maxicount;	/* maximum inode count */
-	__uint64_t		m_maxioffset;	/* maximum inode offset */
 	__uint64_t		m_resblks;	/* total reserved blocks */
 	__uint64_t		m_resblks_avail;/* available reserved blocks */
 	__uint64_t		m_resblks_save;	/* reserved blks @ remount,ro */
@@ -297,7 +296,7 @@ xfs_preferred_iosize(xfs_mount_t *mp)
 			PAGE_CACHE_SIZE));
 }
 
-#define XFS_MAXIOFFSET(mp)	((mp)->m_maxioffset)
+#define XFS_MAXIOFFSET(mp)	((mp)->m_super->s_maxbytes)
 
 #define XFS_LAST_UNMOUNT_WAS_CLEAN(mp)	\
 				((mp)->m_flags & XFS_MOUNT_WAS_CLEAN)