make the feature checks in ->fallocate future proof

Instead of various home grown checks that might need updates for new
flags just check for any bit outside the mask of the features supported
by the filesystem.  This makes the check future proof for any newly
added flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/btrfs/inode.c

@@ -7116,7 +7116,7 @@ static long btrfs_fallocate(struct inode *inode, int mode,
 	alloc_end =  (offset + len + mask) & ~mask;
 
 	/* We only support the FALLOC_FL_KEEP_SIZE mode */
-	if (mode && (mode != FALLOC_FL_KEEP_SIZE))
+	if (mode & ~FALLOC_FL_KEEP_SIZE)
 		return -EOPNOTSUPP;
 
 	/*

fs/ext4/extents.c

@@ -3645,7 +3645,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
 	unsigned int credits, blkbits = inode->i_blkbits;
 
 	/* We only support the FALLOC_FL_KEEP_SIZE mode */
-	if (mode && (mode != FALLOC_FL_KEEP_SIZE))
+	if (mode & ~FALLOC_FL_KEEP_SIZE)
 		return -EOPNOTSUPP;
 
 	/*

fs/gfs2/ops_inode.c

@@ -1426,7 +1426,7 @@ static long gfs2_fallocate(struct inode *inode, int mode, loff_t offset,
 	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
 
 	/* We only support the FALLOC_FL_KEEP_SIZE mode */
-	if (mode && (mode != FALLOC_FL_KEEP_SIZE))
+	if (mode & ~FALLOC_FL_KEEP_SIZE)
 		return -EOPNOTSUPP;
 
 	offset = (offset >> sdp->sd_sb.sb_bsize_shift) <<

fs/ocfs2/file.c

@@ -1997,6 +1997,8 @@ static long ocfs2_fallocate(struct inode *inode, int mode, loff_t offset,
 	int change_size = 1;
 	int cmd = OCFS2_IOC_RESVSP64;
 
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+		return -EOPNOTSUPP;
 	if (!ocfs2_writes_unwritten_extents(osb))
 		return -EOPNOTSUPP;
 

fs/xfs/linux-2.6/xfs_iops.c

@@ -518,6 +518,9 @@ xfs_vn_fallocate(
 	xfs_inode_t	*ip = XFS_I(inode);
 	int		cmd = XFS_IOC_RESVSP;
 
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+		return -EOPNOTSUPP;
+
 	/* preallocation on directories not yet supported */
 	error = -ENODEV;
 	if (S_ISDIR(inode->i_mode))