xfs: check sizes of XFS on-disk structures at compile time

Check the sizes of XFS on-disk structures when compiling the kernel.
Use this to catch inadvertent changes in structure size due to padding
and alignment issues, etc.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
new file mode 100644 (file)
index 0000000..184c44e
--- /dev/null
+++ b/fs/xfs/xfs_ondisk.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2016 Oracle.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#ifndef __XFS_ONDISK_H
+#define __XFS_ONDISK_H
+
+#define XFS_CHECK_STRUCT_SIZE(structname, size) \
+       BUILD_BUG_ON_MSG(sizeof(structname) != (size), "XFS: sizeof(" \
+               #structname ") is wrong, expected " #size)
+
+static inline void __init
+xfs_check_ondisk_structs(void)
+{
+       /* ag/file structures */
+       XFS_CHECK_STRUCT_SIZE(struct xfs_acl,                   4);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_acl_entry,             12);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_agf,                   224);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_agfl,                  36);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_agi,                   336);
+       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,           72);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dinode,                176);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_disk_dquot,            104);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dqblk,                 136);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dsb,                   264);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dsymlink_hdr,          56);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_inobt_key,             4);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_inobt_rec,             16);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_timestamp,             8);
+       XFS_CHECK_STRUCT_SIZE(xfs_alloc_key_t,                  8);
+       XFS_CHECK_STRUCT_SIZE(xfs_alloc_ptr_t,                  4);
+       XFS_CHECK_STRUCT_SIZE(xfs_alloc_rec_t,                  8);
+       XFS_CHECK_STRUCT_SIZE(xfs_inobt_ptr_t,                  4);
+
+       /* dir/attr trees */
+       XFS_CHECK_STRUCT_SIZE(struct xfs_attr3_leaf_hdr,        80);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_attr3_leafblock,       88);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_attr3_rmt_hdr,         56);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_da3_blkinfo,           56);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_da3_intnode,           64);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_da3_node_hdr,          64);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dir3_blk_hdr,          48);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dir3_data_hdr,         64);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dir3_free,             64);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dir3_free_hdr,         64);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dir3_leaf,             64);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dir3_leaf_hdr,         64);
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_leaf_entry_t,            8);
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_leaf_hdr_t,              32);
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_leaf_map_t,              4);
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_leaf_name_local_t,       4);
+
+       /*
+        * m68k has problems with xfs_attr_leaf_name_remote_t, but we pad it to
+        * 4 bytes anyway so it's not obviously a problem.  Hence for the moment
+        * we don't check this structure. This can be re-instated when the attr
+        * definitions are updated to use c99 VLA definitions.
+        *
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_leaf_name_remote_t,      12);
+        */
+
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_leafblock_t,             40);
+       XFS_CHECK_STRUCT_SIZE(xfs_attr_shortform_t,             8);
+       XFS_CHECK_STRUCT_SIZE(xfs_da_blkinfo_t,                 12);
+       XFS_CHECK_STRUCT_SIZE(xfs_da_intnode_t,                 16);
+       XFS_CHECK_STRUCT_SIZE(xfs_da_node_entry_t,              8);
+       XFS_CHECK_STRUCT_SIZE(xfs_da_node_hdr_t,                16);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_data_free_t,             4);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_data_hdr_t,              16);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_data_unused_t,           6);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_free_hdr_t,              16);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_free_t,                  16);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_ino4_t,                  4);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_ino8_t,                  8);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_inou_t,                  8);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_leaf_entry_t,            8);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_leaf_hdr_t,              16);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_leaf_t,                  16);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_leaf_tail_t,             4);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_sf_entry_t,              3);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_sf_hdr_t,                10);
+       XFS_CHECK_STRUCT_SIZE(xfs_dir2_sf_off_t,                2);
+
+       /* log structures */
+       XFS_CHECK_STRUCT_SIZE(struct xfs_dq_logformat,          24);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_32,     28);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_64,     32);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32,     28);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_64,     32);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_extent_32,             12);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_extent_64,             16);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_log_dinode,            176);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_icreate_log,           28);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_ictimestamp,           8);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_32,   52);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_64,   56);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_qoff_logformat,        20);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_trans_header,          16);
+}
+
+#endif /* __XFS_ONDISK_H */

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 59c9b7b..3bd2027 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -45,6 +45,7 @@
 #include "xfs_filestream.h"
 #include "xfs_quota.h"
 #include "xfs_sysfs.h"
+#include "xfs_ondisk.h"
 
 #include <linux/namei.h>
 #include <linux/init.h>
@@ -1817,6 +1818,8 @@ init_xfs_fs(void)
 {
        int                     error;
 
+       xfs_check_ondisk_structs();
+
        printk(KERN_INFO XFS_VERSION_STRING " with "
                         XFS_BUILD_OPTIONS " enabled\n");