diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index a6779b3e873c..07eeb0b4ca74 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -543,12 +543,12 @@ xfs_btree_ptr_addr(
  */
 STATIC struct xfs_btree_block *
 xfs_btree_get_iroot(
-       struct xfs_btree_cur    *cur)
+	struct xfs_btree_cur	*cur)
 {
-       struct xfs_ifork        *ifp;
+	struct xfs_ifork	*ifp;
 
-       ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
-       return (struct xfs_btree_block *)ifp->if_broot;
+	ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
+	return (struct xfs_btree_block *)ifp->if_broot;
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index dc97eb21af07..adb204d40f22 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -1435,41 +1435,57 @@ typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
  * with the crc feature bit, and all accesses to them must be conditional on
  * that flag.
  */
+/* short form block header */
+struct xfs_btree_block_shdr {
+	__be32		bb_leftsib;
+	__be32		bb_rightsib;
+
+	__be64		bb_blkno;
+	__be64		bb_lsn;
+	uuid_t		bb_uuid;
+	__be32		bb_owner;
+	__le32		bb_crc;
+};
+
+/* long form block header */
+struct xfs_btree_block_lhdr {
+	__be64		bb_leftsib;
+	__be64		bb_rightsib;
+
+	__be64		bb_blkno;
+	__be64		bb_lsn;
+	uuid_t		bb_uuid;
+	__be64		bb_owner;
+	__le32		bb_crc;
+	__be32		bb_pad; /* padding for alignment */
+};
+
 struct xfs_btree_block {
 	__be32		bb_magic;	/* magic number for block type */
 	__be16		bb_level;	/* 0 is a leaf */
 	__be16		bb_numrecs;	/* current # of data records */
 	union {
-		struct {
-			__be32		bb_leftsib;
-			__be32		bb_rightsib;
-
-			__be64		bb_blkno;
-			__be64		bb_lsn;
-			uuid_t		bb_uuid;
-			__be32		bb_owner;
-			__le32		bb_crc;
-		} s;			/* short form pointers */
-		struct	{
-			__be64		bb_leftsib;
-			__be64		bb_rightsib;
-
-			__be64		bb_blkno;
-			__be64		bb_lsn;
-			uuid_t		bb_uuid;
-			__be64		bb_owner;
-			__le32		bb_crc;
-			__be32		bb_pad; /* padding for alignment */
-		} l;			/* long form pointers */
+		struct xfs_btree_block_shdr s;
+		struct xfs_btree_block_lhdr l;
 	} bb_u;				/* rest */
 };
 
-#define XFS_BTREE_SBLOCK_LEN	16	/* size of a short form block */
-#define XFS_BTREE_LBLOCK_LEN	24	/* size of a long form block */
+/* size of a short form block */
+#define XFS_BTREE_SBLOCK_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 offsetof(struct xfs_btree_block_shdr, bb_blkno))
+/* size of a long form block */
+#define XFS_BTREE_LBLOCK_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 offsetof(struct xfs_btree_block_lhdr, bb_blkno))
 
 /* sizes of CRC enabled btree blocks */
-#define XFS_BTREE_SBLOCK_CRC_LEN	(XFS_BTREE_SBLOCK_LEN + 40)
-#define XFS_BTREE_LBLOCK_CRC_LEN	(XFS_BTREE_LBLOCK_LEN + 48)
+#define XFS_BTREE_SBLOCK_CRC_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 sizeof(struct xfs_btree_block_shdr))
+#define XFS_BTREE_LBLOCK_CRC_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 sizeof(struct xfs_btree_block_lhdr))
 
 #define XFS_BTREE_SBLOCK_CRC_OFF \
 	offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index 355619ae5e3e..ed7ee4e8af73 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -55,7 +55,7 @@ xfs_error_test(int error_tag, int *fsidp, char *expression,
 }
 
 int
-xfs_errortag_add(int error_tag, xfs_mount_t *mp)
+xfs_errortag_add(unsigned int error_tag, xfs_mount_t *mp)
 {
 	int i;
 	int len;
diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
index 4ed3042a0f16..2e4f67f68856 100644
--- a/fs/xfs/xfs_error.h
+++ b/fs/xfs/xfs_error.h
@@ -128,7 +128,7 @@ extern int xfs_error_test(int, int *, char *, int, char *, unsigned long);
 	 xfs_error_test((tag), (mp)->m_fixedfsid, "expr", __LINE__, __FILE__, \
 			(rf))))
 
-extern int xfs_errortag_add(int error_tag, struct xfs_mount *mp);
+extern int xfs_errortag_add(unsigned int error_tag, struct xfs_mount *mp);
 extern int xfs_errortag_clearall(struct xfs_mount *mp, int loud);
 #else
 #define XFS_TEST_ERROR(expr, mp, tag, rf)	(expr)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index dbca7375deef..408f3ad348ab 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1575,6 +1575,17 @@ xfs_ioc_swapext(
 		goto out_put_tmp_file;
 	}
 
+	/*
+	 * We need to ensure that the fds passed in point to XFS inodes
+	 * before we cast and access them as XFS structures as we have no
+	 * control over what the user passes us here.
+	 */
+	if (f.file->f_op != &xfs_file_operations ||
+	    tmp.file->f_op != &xfs_file_operations) {
+		error = -EINVAL;
+		goto out_put_tmp_file;
+	}
+
 	ip = XFS_I(file_inode(f.file));
 	tip = XFS_I(file_inode(tmp.file));
 
diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
index 027230134098..17ec0248f771 100644
--- a/fs/xfs/xfs_ondisk.h
+++ b/fs/xfs/xfs_ondisk.h
@@ -39,6 +39,8 @@ xfs_check_ondisk_structs(void)
 	XFS_CHECK_STRUCT_SIZE(struct xfs_bmbt_key,		8);
 	XFS_CHECK_STRUCT_SIZE(struct xfs_bmbt_rec,		16);
 	XFS_CHECK_STRUCT_SIZE(struct xfs_bmdr_block,		4);
+	XFS_CHECK_STRUCT_SIZE(struct xfs_btree_block_shdr,	48);
+	XFS_CHECK_STRUCT_SIZE(struct xfs_btree_block_lhdr,	64);
 	XFS_CHECK_STRUCT_SIZE(struct xfs_btree_block,		72);
 	XFS_CHECK_STRUCT_SIZE(struct xfs_dinode,		176);
 	XFS_CHECK_STRUCT_SIZE(struct xfs_disk_dquot,		104);