[2/3] design: document the actual ondisk superblock

Commit Message

Darrick J. Wong Nov. 7, 2024, 11:25 p.m. UTC

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

struct xfs_dsb is the ondisk superblock, not struct xfs_sb.  Replace the
struct definition with the one for the the ondisk superblock.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 .../XFS_Filesystem_Structure/superblock.asciidoc   |  117 ++++++++++----------
 1 file changed, 58 insertions(+), 59 deletions(-)

Comments

Christoph Hellwig Nov. 8, 2024, 2:16 p.m. UTC | #1

Looks good:

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

Patch

diff --git a/design/XFS_Filesystem_Structure/superblock.asciidoc b/design/XFS_Filesystem_Structure/superblock.asciidoc
index 16c31116ffafd4..79e8c30dc93e79 100644
--- a/design/XFS_Filesystem_Structure/superblock.asciidoc
+++ b/design/XFS_Filesystem_Structure/superblock.asciidoc
@@ -11,68 +11,67 @@  field follows.
 
 [source, c]
 ----
-struct xfs_sb
-{
-	__uint32_t		sb_magicnum;
-	__uint32_t		sb_blocksize;
-	xfs_rfsblock_t		sb_dblocks;
-	xfs_rfsblock_t		sb_rblocks;
-	xfs_rtblock_t		sb_rextents;
-	uuid_t			sb_uuid;
-	xfs_fsblock_t		sb_logstart;
-	xfs_ino_t		sb_rootino;
-	xfs_ino_t		sb_rbmino;
-	xfs_ino_t		sb_rsumino;
-	xfs_agblock_t		sb_rextsize;
-	xfs_agblock_t		sb_agblocks;
-	xfs_agnumber_t		sb_agcount;
-	xfs_extlen_t		sb_rbmblocks;
-	xfs_extlen_t		sb_logblocks;
-	__uint16_t		sb_versionnum;
-	__uint16_t		sb_sectsize;
-	__uint16_t		sb_inodesize;
-	__uint16_t		sb_inopblock;
-	char			sb_fname[12];
-	__uint8_t		sb_blocklog;
-	__uint8_t		sb_sectlog;
-	__uint8_t		sb_inodelog;
-	__uint8_t		sb_inopblog;
-	__uint8_t		sb_agblklog;
-	__uint8_t		sb_rextslog;
-	__uint8_t		sb_inprogress;
-	__uint8_t		sb_imax_pct;
-	__uint64_t		sb_icount;
-	__uint64_t		sb_ifree;
-	__uint64_t		sb_fdblocks;
-	__uint64_t		sb_frextents;
-	xfs_ino_t		sb_uquotino;
-	xfs_ino_t		sb_gquotino;
-	__uint16_t		sb_qflags;
-	__uint8_t		sb_flags;
-	__uint8_t		sb_shared_vn;
-	xfs_extlen_t		sb_inoalignmt;
-	__uint32_t		sb_unit;
-	__uint32_t		sb_width;
-	__uint8_t		sb_dirblklog;
-	__uint8_t		sb_logsectlog;
-	__uint16_t		sb_logsectsize;
-	__uint32_t		sb_logsunit;
-	__uint32_t		sb_features2;
-	__uint32_t		sb_bad_features2;
+struct xfs_dsb {
+	__be32		sb_magicnum;
+	__be32		sb_blocksize;
+	__be64		sb_dblocks;
+	__be64		sb_rblocks;
+	__be64		sb_rextents;
+	uuid_t		sb_uuid;
+	__be64		sb_logstart;
+	__be64		sb_rootino;
+	__be64		sb_rbmino;
+	__be64		sb_rsumino;
+	__be32		sb_rextsize;
+	__be32		sb_agblocks;
+	__be32		sb_agcount;
+	__be32		sb_rbmblocks;
+	__be32		sb_logblocks;
+	__be16		sb_versionnum;
+	__be16		sb_sectsize;
+	__be16		sb_inodesize;
+	__be16		sb_inopblock;
+	char		sb_fname[XFSLABEL_MAX];
+	__u8		sb_blocklog;
+	__u8		sb_sectlog;
+	__u8		sb_inodelog;
+	__u8		sb_inopblog;
+	__u8		sb_agblklog;
+	__u8		sb_rextslog;
+	__u8		sb_inprogress;
+	__u8		sb_imax_pct;
+	__be64		sb_icount;
+	__be64		sb_ifree;
+	__be64		sb_fdblocks;
+	__be64		sb_frextents;
+	__be64		sb_uquotino;
+	__be64		sb_gquotino;
+	__be16		sb_qflags;
+	__u8		sb_flags;
+	__u8		sb_shared_vn;
+	__be32		sb_inoalignmt;
+	__be32		sb_unit;
+	__be32		sb_width;
+	__u8		sb_dirblklog;
+	__u8		sb_logsectlog;
+	__be16		sb_logsectsize;
+	__be32		sb_logsunit;
+	__be32		sb_features2;
+	__be32		sb_bad_features2;
 
 	/* version 5 superblock fields start here */
-	__uint32_t		sb_features_compat;
-	__uint32_t		sb_features_ro_compat;
-	__uint32_t		sb_features_incompat;
-	__uint32_t		sb_features_log_incompat;
+	__be32		sb_features_compat;
+	__be32		sb_features_ro_compat;
+	__be32		sb_features_incompat;
+	__be32		sb_features_log_incompat;
+	__le32		sb_crc;
+	__be32		sb_spino_align;
+	__be64		sb_pquotino;
+	__be64		sb_lsn;
+	uuid_t		sb_meta_uuid;
+	__be64		sb_rrmapino;
 
-	__uint32_t		sb_crc;
-	xfs_extlen_t		sb_spino_align;
-
-	xfs_ino_t		sb_pquotino;
-	xfs_lsn_t		sb_lsn;
-	uuid_t			sb_meta_uuid;
-	xfs_ino_t		sb_rrmapino;
+	/* must be padded to 64 bit alignment */
 };
 ----
 *sb_magicnum*::