[3/4] xfs_db/mdrestore/repair: don't use the incore struct xfs_sb for offsets into struct xfs_dsb

Commit Message

Darrick J. Wong Oct. 2, 2024, 1:25 a.m. UTC

From: Darrick J. Wong <[e-mail]>

Source kernel commit: ac3a0275165b4f80d9b7b516d6a8f8b308644fff

Currently, the XFS_SB_CRC_OFF macro uses the incore superblock struct
(xfs_sb) to compute the address of sb_crc within the ondisk superblock
struct (xfs_dsb).  This is a landmine if we ever change the layout of
the incore superblock (as we're about to do), so redefine the macro
to use xfs_dsb to compute the layout of xfs_dsb.

Port the userspace utilities to the new code just like we did for the
kernel.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 db/sb.c                   |    4 ++--
 mdrestore/xfs_mdrestore.c |    6 ++----
 repair/agheader.c         |   12 ++++++------
 3 files changed, 10 insertions(+), 12 deletions(-)

Comments

Christoph Hellwig Oct. 2, 2024, 5:54 a.m. UTC | #1

>  	if (xfs_sb_version_hasmetauuid(sb))
> -		size = offsetof(xfs_sb_t, sb_meta_uuid)
> +		size = offsetof(struct xfs_dsb, sb_meta_uuid)
>  			+ sizeof(sb->sb_meta_uuid);

It would be nice to fix the formatting here, or maybe even add a a
field_end() or simіlar helper here..

Otherwise looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/db/sb.c b/db/sb.c
index 7836384a1..9fcb7340f 100644
--- a/db/sb.c
+++ b/db/sb.c
@@ -50,8 +50,8 @@  sb_init(void)
 	add_command(&version_cmd);
 }
 
-#define	OFF(f)	bitize(offsetof(xfs_sb_t, sb_ ## f))
-#define	SZC(f)	szcount(xfs_sb_t, sb_ ## f)
+#define	OFF(f)	bitize(offsetof(struct xfs_dsb, sb_ ## f))
+#define	SZC(f)	szcount(struct xfs_dsb, sb_ ## f)
 const field_t	sb_flds[] = {
 	{ "magicnum", FLDT_UINT32X, OI(OFF(magicnum)), C1, 0, TYP_NONE },
 	{ "blocksize", FLDT_UINT32D, OI(OFF(blocksize)), C1, 0, TYP_NONE },
diff --git a/mdrestore/xfs_mdrestore.c b/mdrestore/xfs_mdrestore.c
index 334bdd228..269edb8f8 100644
--- a/mdrestore/xfs_mdrestore.c
+++ b/mdrestore/xfs_mdrestore.c
@@ -101,10 +101,8 @@  fixup_superblock(
 	memset(block_buffer, 0, sb->sb_sectsize);
 	sb->sb_inprogress = 0;
 	libxfs_sb_to_disk((struct xfs_dsb *)block_buffer, sb);
-	if (xfs_sb_version_hascrc(sb)) {
-		xfs_update_cksum(block_buffer, sb->sb_sectsize,
-				 offsetof(struct xfs_sb, sb_crc));
-	}
+	if (xfs_sb_version_hascrc(sb))
+		xfs_update_cksum(block_buffer, sb->sb_sectsize, XFS_SB_CRC_OFF);
 
 	if (pwrite(ddev_fd, block_buffer, sb->sb_sectsize, 0) < 0)
 		fatal("error writing primary superblock: %s\n", strerror(errno));
diff --git a/repair/agheader.c b/repair/agheader.c
index 762901581..3930a0ac0 100644
--- a/repair/agheader.c
+++ b/repair/agheader.c
@@ -358,22 +358,22 @@  secondary_sb_whack(
 	 * size is the size of data which is valid for this sb.
 	 */
 	if (xfs_sb_version_hasmetauuid(sb))
-		size = offsetof(xfs_sb_t, sb_meta_uuid)
+		size = offsetof(struct xfs_dsb, sb_meta_uuid)
 			+ sizeof(sb->sb_meta_uuid);
 	else if (xfs_sb_version_hascrc(sb))
-		size = offsetof(xfs_sb_t, sb_lsn)
+		size = offsetof(struct xfs_dsb, sb_lsn)
 			+ sizeof(sb->sb_lsn);
 	else if (xfs_sb_version_hasmorebits(sb))
-		size = offsetof(xfs_sb_t, sb_bad_features2)
+		size = offsetof(struct xfs_dsb, sb_bad_features2)
 			+ sizeof(sb->sb_bad_features2);
 	else if (xfs_sb_version_haslogv2(sb))
-		size = offsetof(xfs_sb_t, sb_logsunit)
+		size = offsetof(struct xfs_dsb, sb_logsunit)
 			+ sizeof(sb->sb_logsunit);
 	else if (xfs_sb_version_hassector(sb))
-		size = offsetof(xfs_sb_t, sb_logsectsize)
+		size = offsetof(struct xfs_dsb, sb_logsectsize)
 			+ sizeof(sb->sb_logsectsize);
 	else /* only support dirv2 or more recent */
-		size = offsetof(xfs_sb_t, sb_dirblklog)
+		size = offsetof(struct xfs_dsb, sb_dirblklog)
 			+ sizeof(sb->sb_dirblklog);
 
 	/* Check the buffer we read from disk for garbage outside size */