[PATCH 15/50] xfs_repair: refactor offsetof+sizeof to offsetofend

Darrick J. Wong
2024-12-07T00:08:49Z

From: Darrick J. Wong <djwong@kernel.org>

Replace this open-coded logic with the kernel's offsetofend macro before
we start adding more in the next patch.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
include/xfs.h | 15 +++++++++++++++
repair/agheader.c | 21 +++++++--------------
2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/include/xfs.h b/include/xfs.h
index e97158c8d223f5..a2f159a586ee71 100644
--- a/include/xfs.h
+++ b/include/xfs.h
@@ -38,8 +38,23 @@ extern int xfs_assert_largefile[sizeof(off_t)-8];
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
#endif

+/**
+ * sizeof_field() - Report the size of a struct field in bytes
+ *
+ * @TYPE: The structure containing the field of interest
+ * @MEMBER: The field to return the size of
+ */
#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))

+/**
+ * offsetofend() - Report the offset of a struct field within the struct
+ *
+ * @TYPE: The type of the structure
+ * @MEMBER: The member within the structure to get the end offset of
+ */
+#define offsetofend(TYPE, MEMBER) \
+ (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
+
#include <xfs/xfs_types.h>
/* Include deprecated/compat pre-vfs xfs-specific symbols */
#include <xfs/xfs_fs_compat.h>
diff --git a/repair/agheader.c b/repair/agheader.c
index fe58d833b8bafa..14aedece3d07b0 100644
--- a/repair/agheader.c
+++ b/repair/agheader.c
@@ -364,26 +364,19 @@ secondary_sb_whack(
* size is the size of data which is valid for this sb.
*/
if (xfs_sb_version_hasmetadir(sb))
- size = offsetof(struct xfs_dsb, sb_metadirino)
- + sizeof(sb->sb_metadirino);
+ size = offsetofend(struct xfs_dsb, sb_metadirino);
else if (xfs_sb_version_hasmetauuid(sb))
- size = offsetof(struct xfs_dsb, sb_meta_uuid)
- + sizeof(sb->sb_meta_uuid);
+ size = offsetofend(struct xfs_dsb, sb_meta_uuid);
else if (xfs_sb_version_hascrc(sb))
- size = offsetof(struct xfs_dsb, sb_lsn)
- + sizeof(sb->sb_lsn);
+ size = offsetofend(struct xfs_dsb, sb_lsn);
else if (xfs_sb_version_hasmorebits(sb))
- size = offsetof(struct xfs_dsb, sb_bad_features2)
- + sizeof(sb->sb_bad_features2);
+ size = offsetofend(struct xfs_dsb, sb_bad_features2);
else if (xfs_sb_version_haslogv2(sb))
- size = offsetof(struct xfs_dsb, sb_logsunit)
- + sizeof(sb->sb_logsunit);
+ size = offsetofend(struct xfs_dsb, sb_logsunit);
else if (xfs_sb_version_hassector(sb))
- size = offsetof(struct xfs_dsb, sb_logsectsize)
- + sizeof(sb->sb_logsectsize);
+ size = offsetofend(struct xfs_dsb, sb_logsectsize);
else /* only support dirv2 or more recent */
- size = offsetof(struct xfs_dsb, sb_dirblklog)
- + sizeof(sb->sb_dirblklog);
+ size = offsetofend(struct xfs_dsb, sb_dirblklog);

/* Check the buffer we read from disk for garbage outside size */
for (ip = (char *)sbuf->b_addr + size;