xfs: remove bitfield based superblock updates

When we log changes to the superblock, we first have to write them
to the on-disk buffer, and then log that. Right now we have a
complex bitfield based arrangement to only write the modified field
to the buffer before we log it.

This used to be necessary as a performance optimisation because we
logged the superblock buffer in every extent or inode allocation or
freeing, and so performance was extremely important. We haven't done
this for years, however, ever since the lazy superblock counters
pulled the superblock logging out of the transaction commit
fast path.

Hence we have a bunch of complexity that is not necessary that makes
writing the in-core superblock to disk much more complex than it
needs to be. We only need to log the superblock now during
management operations (e.g. during mount, unmount or quota control
operations) so it is not a performance critical path anymore.

As such, remove the complex field based logging mechanism and
replace it with a simple conversion function similar to what we use
for all other on-disk structures.

This means we always log the entirity of the superblock, but again
because we rarely modify the superblock this is not an issue for log
bandwidth or CPU time. Indeed, if we do log the superblock
frequently, delayed logging will minimise the impact of this
overhead.

[Fixed gquota/pquota inode sharing regression noticed by bfoster.]

Signed-off-by: Dave Chinner <[e-mail]>
Reviewed-by: Brian Foster <[e-mail]>
Signed-off-by: Dave Chinner <[e-mail]>

fs/xfs/libxfs/xfs_attr_leaf.c

···
 		if (!xfs_sb_version_hasattr2(&mp->m_sb)) {
 			xfs_sb_version_addattr2(&mp->m_sb);
 			spin_unlock(&mp->m_sb_lock);
-			xfs_mod_sb(tp, XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
+			xfs_mod_sb(tp);
 		} else
 			spin_unlock(&mp->m_sb_lock);
 	}

fs/xfs/libxfs/xfs_bmap.c

···
 		goto bmap_cancel;
 	if (!xfs_sb_version_hasattr(&mp->m_sb) ||
 	   (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2)) {
-		__int64_t sbfields = 0;
+		bool mod_sb = false;
 
 		spin_lock(&mp->m_sb_lock);
 		if (!xfs_sb_version_hasattr(&mp->m_sb)) {
 			xfs_sb_version_addattr(&mp->m_sb);
-			sbfields |= XFS_SB_VERSIONNUM;
+			mod_sb = true;
 		}
 		if (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2) {
 			xfs_sb_version_addattr2(&mp->m_sb);
-			sbfields |= (XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
+			mod_sb = true;
 		}
-		if (sbfields) {
-			spin_unlock(&mp->m_sb_lock);
-			xfs_mod_sb(tp, sbfields);
-		} else
-			spin_unlock(&mp->m_sb_lock);
+		spin_unlock(&mp->m_sb_lock);
+		if (mod_sb)
+			xfs_mod_sb(tp);
 	}
 
 	error = xfs_bmap_finish(&tp, &flist, &committed);

fs/xfs/libxfs/xfs_sb.c

···
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
  */
 
-static const struct {
-	short offset;
-	short type;	/* 0 = integer
-			 * 1 = binary / string (no translation)
-			 */
-} xfs_sb_info[] = {
-	{ offsetof(xfs_sb_t, sb_magicnum),	0 },
-	{ offsetof(xfs_sb_t, sb_blocksize),	0 },
-	{ offsetof(xfs_sb_t, sb_dblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_rblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_rextents),	0 },
-	{ offsetof(xfs_sb_t, sb_uuid),		1 },
-	{ offsetof(xfs_sb_t, sb_logstart),	0 },
-	{ offsetof(xfs_sb_t, sb_rootino),	0 },
-	{ offsetof(xfs_sb_t, sb_rbmino),	0 },
-	{ offsetof(xfs_sb_t, sb_rsumino),	0 },
-	{ offsetof(xfs_sb_t, sb_rextsize),	0 },
-	{ offsetof(xfs_sb_t, sb_agblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_agcount),	0 },
-	{ offsetof(xfs_sb_t, sb_rbmblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_logblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_versionnum),	0 },
-	{ offsetof(xfs_sb_t, sb_sectsize),	0 },
-	{ offsetof(xfs_sb_t, sb_inodesize),	0 },
-	{ offsetof(xfs_sb_t, sb_inopblock),	0 },
-	{ offsetof(xfs_sb_t, sb_fname[0]),	1 },
-	{ offsetof(xfs_sb_t, sb_blocklog),	0 },
-	{ offsetof(xfs_sb_t, sb_sectlog),	0 },
-	{ offsetof(xfs_sb_t, sb_inodelog),	0 },
-	{ offsetof(xfs_sb_t, sb_inopblog),	0 },
-	{ offsetof(xfs_sb_t, sb_agblklog),	0 },
-	{ offsetof(xfs_sb_t, sb_rextslog),	0 },
-	{ offsetof(xfs_sb_t, sb_inprogress),	0 },
-	{ offsetof(xfs_sb_t, sb_imax_pct),	0 },
-	{ offsetof(xfs_sb_t, sb_icount),	0 },
-	{ offsetof(xfs_sb_t, sb_ifree),		0 },
-	{ offsetof(xfs_sb_t, sb_fdblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_frextents),	0 },
-	{ offsetof(xfs_sb_t, sb_uquotino),	0 },
-	{ offsetof(xfs_sb_t, sb_gquotino),	0 },
-	{ offsetof(xfs_sb_t, sb_qflags),	0 },
-	{ offsetof(xfs_sb_t, sb_flags),		0 },
-	{ offsetof(xfs_sb_t, sb_shared_vn),	0 },
-	{ offsetof(xfs_sb_t, sb_inoalignmt),	0 },
-	{ offsetof(xfs_sb_t, sb_unit),		0 },
-	{ offsetof(xfs_sb_t, sb_width),		0 },
-	{ offsetof(xfs_sb_t, sb_dirblklog),	0 },
-	{ offsetof(xfs_sb_t, sb_logsectlog),	0 },
-	{ offsetof(xfs_sb_t, sb_logsectsize),	0 },
-	{ offsetof(xfs_sb_t, sb_logsunit),	0 },
-	{ offsetof(xfs_sb_t, sb_features2),	0 },
-	{ offsetof(xfs_sb_t, sb_bad_features2),	0 },
-	{ offsetof(xfs_sb_t, sb_features_compat),	0 },
-	{ offsetof(xfs_sb_t, sb_features_ro_compat),	0 },
-	{ offsetof(xfs_sb_t, sb_features_incompat),	0 },
-	{ offsetof(xfs_sb_t, sb_features_log_incompat),	0 },
-	{ offsetof(xfs_sb_t, sb_crc),		0 },
-	{ offsetof(xfs_sb_t, sb_pad),		0 },
-	{ offsetof(xfs_sb_t, sb_pquotino),	0 },
-	{ offsetof(xfs_sb_t, sb_lsn),		0 },
-	{ sizeof(xfs_sb_t),			0 }
-};
-
 /*
  * Reference counting access wrappers to the perag structures.
  * Because we never free per-ag structures, the only thing we
···
 	__xfs_sb_from_disk(to, from, true);
 }
 
-static inline void
+static void
 xfs_sb_quota_to_disk(
-	xfs_dsb_t	*to,
-	xfs_sb_t	*from,
-	__int64_t	*fields)
+	struct xfs_dsb	*to,
+	struct xfs_sb	*from)
 {
 	__uint16_t	qflags = from->sb_qflags;
 
-	/*
-	 * We need to do these manipilations only if we are working
-	 * with an older version of on-disk superblock.
-	 */
-	if (xfs_sb_version_has_pquotino(from))
+	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
+	if (xfs_sb_version_has_pquotino(from)) {
+		to->sb_qflags = cpu_to_be16(from->sb_qflags);
+		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
+		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
 		return;
-
-	if (*fields & XFS_SB_QFLAGS) {
-		/*
-		 * The in-core version of sb_qflags do not have
-		 * XFS_OQUOTA_* flags, whereas the on-disk version
-		 * does.  So, convert incore XFS_{PG}QUOTA_* flags
-		 * to on-disk XFS_OQUOTA_* flags.
-		 */
-		qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
-				XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
-
-		if (from->sb_qflags &
-				(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
-			qflags |= XFS_OQUOTA_ENFD;
-		if (from->sb_qflags &
-				(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
-			qflags |= XFS_OQUOTA_CHKD;
-		to->sb_qflags = cpu_to_be16(qflags);
-		*fields &= ~XFS_SB_QFLAGS;
 	}
 
 	/*
-	 * GQUOTINO and PQUOTINO cannot be used together in versions of
-	 * superblock that do not have pquotino. from->sb_flags tells us which
-	 * quota is active and should be copied to disk. If neither are active,
-	 * make sure we write NULLFSINO to the sb_gquotino field as a quota
-	 * inode value of "0" is invalid when the XFS_SB_VERSION_QUOTA feature
-	 * bit is set.
-	 *
-	 * Note that we don't need to handle the sb_uquotino or sb_pquotino here
-	 * as they do not require any translation. Hence the main sb field loop
-	 * will write them appropriately from the in-core superblock.
+	 * The in-core version of sb_qflags do not have XFS_OQUOTA_*
+	 * flags, whereas the on-disk version does.  So, convert incore
+	 * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
 	 */
-	if ((*fields & XFS_SB_GQUOTINO) &&
-				(from->sb_qflags & XFS_GQUOTA_ACCT))
+	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
+			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
+
+	if (from->sb_qflags &
+			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
+		qflags |= XFS_OQUOTA_ENFD;
+	if (from->sb_qflags &
+			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
+		qflags |= XFS_OQUOTA_CHKD;
+	to->sb_qflags = cpu_to_be16(qflags);
+
+	/*
+	 * GQUOTINO and PQUOTINO cannot be used together in versions
+	 * of superblock that do not have pquotino. from->sb_flags
+	 * tells us which quota is active and should be copied to
+	 * disk. If neither are active, we should NULL the inode.
+	 *
+	 * In all cases, the separate pquotino must remain 0 because it
+	 * it beyond the "end" of the valid non-pquotino superblock.
+	 */
+	if (from->sb_qflags & XFS_GQUOTA_ACCT)
 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
-	else if ((*fields & XFS_SB_PQUOTINO) &&
-				(from->sb_qflags & XFS_PQUOTA_ACCT))
+	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
 	else {
 		/*
···
 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
 	}
 
-	*fields &= ~(XFS_SB_PQUOTINO | XFS_SB_GQUOTINO);
+	to->sb_pquotino = 0;
 }
 
-/*
- * Copy in core superblock to ondisk one.
- *
- * The fields argument is mask of superblock fields to copy.
- */
 void
 xfs_sb_to_disk(
-	xfs_dsb_t	*to,
-	xfs_sb_t	*from,
-	__int64_t	fields)
+	struct xfs_dsb	*to,
+	struct xfs_sb	*from)
 {
-	xfs_caddr_t	to_ptr = (xfs_caddr_t)to;
-	xfs_caddr_t	from_ptr = (xfs_caddr_t)from;
-	xfs_sb_field_t	f;
-	int		first;
-	int		size;
+	xfs_sb_quota_to_disk(to, from);
 
-	ASSERT(fields);
-	if (!fields)
-		return;
+	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
+	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
+	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
+	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
+	to->sb_rextents = cpu_to_be64(from->sb_rextents);
+	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
+	to->sb_logstart = cpu_to_be64(from->sb_logstart);
+	to->sb_rootino = cpu_to_be64(from->sb_rootino);
+	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
+	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
+	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
+	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
+	to->sb_agcount = cpu_to_be32(from->sb_agcount);
+	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
+	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
+	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
+	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
+	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
+	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
+	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
+	to->sb_blocklog = from->sb_blocklog;
+	to->sb_sectlog = from->sb_sectlog;
+	to->sb_inodelog = from->sb_inodelog;
+	to->sb_inopblog = from->sb_inopblog;
+	to->sb_agblklog = from->sb_agblklog;
+	to->sb_rextslog = from->sb_rextslog;
+	to->sb_inprogress = from->sb_inprogress;
+	to->sb_imax_pct = from->sb_imax_pct;
+	to->sb_icount = cpu_to_be64(from->sb_icount);
+	to->sb_ifree = cpu_to_be64(from->sb_ifree);
+	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
+	to->sb_frextents = cpu_to_be64(from->sb_frextents);
 
-	/* We should never write the crc here, it's updated in the IO path */
-	fields &= ~XFS_SB_CRC;
 
-	xfs_sb_quota_to_disk(to, from, &fields);
-	while (fields) {
-		f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
-		first = xfs_sb_info[f].offset;
-		size = xfs_sb_info[f + 1].offset - first;
+	to->sb_flags = from->sb_flags;
+	to->sb_shared_vn = from->sb_shared_vn;
+	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
+	to->sb_unit = cpu_to_be32(from->sb_unit);
+	to->sb_width = cpu_to_be32(from->sb_width);
+	to->sb_dirblklog = from->sb_dirblklog;
+	to->sb_logsectlog = from->sb_logsectlog;
+	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
+	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
+	to->sb_features2 = cpu_to_be32(from->sb_features2);
+	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
 
-		ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
-
-		if (size == 1 || xfs_sb_info[f].type == 1) {
-			memcpy(to_ptr + first, from_ptr + first, size);
-		} else {
-			switch (size) {
-			case 2:
-				*(__be16 *)(to_ptr + first) =
-				      cpu_to_be16(*(__u16 *)(from_ptr + first));
-				break;
-			case 4:
-				*(__be32 *)(to_ptr + first) =
-				      cpu_to_be32(*(__u32 *)(from_ptr + first));
-				break;
-			case 8:
-				*(__be64 *)(to_ptr + first) =
-				      cpu_to_be64(*(__u64 *)(from_ptr + first));
-				break;
-			default:
-				ASSERT(0);
-			}
-		}
-
-		fields &= ~(1LL << f);
+	if (xfs_sb_version_hascrc(from)) {
+		to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
+		to->sb_features_ro_compat =
+				cpu_to_be32(from->sb_features_ro_compat);
+		to->sb_features_incompat =
+				cpu_to_be32(from->sb_features_incompat);
+		to->sb_features_log_incompat =
+				cpu_to_be32(from->sb_features_log_incompat);
+		to->sb_pad = 0;
+		to->sb_lsn = cpu_to_be64(from->sb_lsn);
 	}
 }
 
···
  * access.
  */
 void
-xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
+xfs_mod_sb(
+	struct xfs_trans	*tp)
 {
-	xfs_buf_t	*bp;
-	int		first;
-	int		last;
-	xfs_mount_t	*mp;
-	xfs_sb_field_t	f;
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_buf		*bp = xfs_trans_getsb(tp, mp, 0);
 
-	ASSERT(fields);
-	if (!fields)
-		return;
-	mp = tp->t_mountp;
-	bp = xfs_trans_getsb(tp, mp, 0);
-	first = sizeof(xfs_sb_t);
-	last = 0;
-
-	/* translate/copy */
-
-	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
-
-	/* find modified range */
-	f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
-	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
-	last = xfs_sb_info[f + 1].offset - 1;
-
-	f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
-	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
-	first = xfs_sb_info[f].offset;
-
+	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
-	xfs_trans_log_buf(tp, bp, first, last);
+	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
 }

fs/xfs/libxfs/xfs_sb.h

···
 extern void	xfs_perag_put(struct xfs_perag *pag);
 extern int	xfs_initialize_perag_data(struct xfs_mount *, xfs_agnumber_t);
 
-extern void	xfs_sb_calc_crc(struct xfs_buf	*);
-extern void	xfs_mod_sb(struct xfs_trans *, __int64_t);
-extern void	xfs_sb_mount_common(struct xfs_mount *, struct xfs_sb *);
-extern void	xfs_sb_from_disk(struct xfs_sb *, struct xfs_dsb *);
-extern void	xfs_sb_to_disk(struct xfs_dsb *, struct xfs_sb *, __int64_t);
+extern void	xfs_sb_calc_crc(struct xfs_buf *bp);
+extern void	xfs_mod_sb(struct xfs_trans *tp);
+extern void	xfs_sb_mount_common(struct xfs_mount *mp, struct xfs_sb *sbp);
+extern void	xfs_sb_from_disk(struct xfs_sb *to, struct xfs_dsb *from);
+extern void	xfs_sb_to_disk(struct xfs_dsb *to, struct xfs_sb *from);
 extern void	xfs_sb_quota_from_disk(struct xfs_sb *sbp);
 
 #endif	/* __XFS_SB_H__ */

fs/xfs/xfs_fsops.c

···
 			saved_error = error;
 			continue;
 		}
-		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
+		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 
 		error = xfs_bwrite(bp);
 		xfs_buf_relse(bp);
···
 		xfs_trans_cancel(tp, 0);
 		return error;
 	}
-
-	/* log the UUID because it is an unchanging field */
-	xfs_mod_sb(tp, XFS_SB_UUID);
+	xfs_mod_sb(tp);
 	xfs_trans_set_sync(tp);
 	return xfs_trans_commit(tp, 0);
 }

fs/xfs/xfs_mount.c

···
 		return error;
 	}
 
-	xfs_mod_sb(tp, XFS_SB_QFLAGS);
+	xfs_mod_sb(tp);
 	return xfs_trans_commit(tp, 0);
 }
 
···
 	 * perform the update e.g. for the root filesystem.
 	 */
 	if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
-		error = xfs_mount_log_sb(mp, mp->m_update_flags);
+		error = xfs_mount_log_sb(mp);
 		if (error) {
 			xfs_warn(mp, "failed to write sb changes");
 			goto out_rtunmount;
···
 		return error;
 	}
 
-	xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
+	xfs_mod_sb(tp);
 	xfs_trans_set_sync(tp);
 	error = xfs_trans_commit(tp, 0);
 	return error;
···
  */
 int
 xfs_mount_log_sb(
-	xfs_mount_t	*mp,
-	__int64_t	fields)
+	struct xfs_mount	*mp)
 {
-	xfs_trans_t	*tp;
-	int		error;
-
-	ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
-			 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
-			 XFS_SB_VERSIONNUM));
+	struct xfs_trans	*tp;
+	int			error;
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
 	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
···
 		xfs_trans_cancel(tp, 0);
 		return error;
 	}
-	xfs_mod_sb(tp, fields);
-	error = xfs_trans_commit(tp, 0);
-	return error;
+	xfs_mod_sb(tp);
+	return xfs_trans_commit(tp, 0);
 }
 
 /*

fs/xfs/xfs_mount.h

···
 extern int	xfs_mod_incore_sb(xfs_mount_t *, xfs_sb_field_t, int64_t, int);
 extern int	xfs_mod_incore_sb_batch(xfs_mount_t *, xfs_mod_sb_t *,
 			uint, int);
-extern int	xfs_mount_log_sb(xfs_mount_t *, __int64_t);
+extern int	xfs_mount_log_sb(xfs_mount_t *);
 extern struct xfs_buf *xfs_getsb(xfs_mount_t *, int);
 extern int	xfs_readsb(xfs_mount_t *, int);
 extern void	xfs_freesb(xfs_mount_t *);

fs/xfs/xfs_qm.c

···
 xfs_qm_qino_alloc(
 	xfs_mount_t	*mp,
 	xfs_inode_t	**ip,
-	__int64_t	sbfields,
 	uint		flags)
 {
 	xfs_trans_t	*tp;
···
 	spin_lock(&mp->m_sb_lock);
 	if (flags & XFS_QMOPT_SBVERSION) {
 		ASSERT(!xfs_sb_version_hasquota(&mp->m_sb));
-		ASSERT((sbfields & (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
-			XFS_SB_GQUOTINO | XFS_SB_PQUOTINO | XFS_SB_QFLAGS)) ==
-				(XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
-				 XFS_SB_GQUOTINO | XFS_SB_PQUOTINO |
-				 XFS_SB_QFLAGS));
 
 		xfs_sb_version_addquota(&mp->m_sb);
 		mp->m_sb.sb_uquotino = NULLFSINO;
···
 	else
 		mp->m_sb.sb_pquotino = (*ip)->i_ino;
 	spin_unlock(&mp->m_sb_lock);
-	xfs_mod_sb(tp, sbfields);
+	xfs_mod_sb(tp);
 
 	if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES))) {
 		xfs_alert(mp, "%s failed (error %d)!", __func__, error);
···
 	spin_unlock(&mp->m_sb_lock);
 
 	if (sbf != (mp->m_qflags & XFS_MOUNT_QUOTA_ALL)) {
-		if (xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS)) {
+		if (xfs_qm_write_sb_changes(mp)) {
 			/*
 			 * We could only have been turning quotas off.
 			 * We aren't in very good shape actually because
···
 	struct xfs_inode	*gip = NULL;
 	struct xfs_inode	*pip = NULL;
 	int			error;
-	__int64_t		sbflags = 0;
 	uint			flags = 0;
 
 	ASSERT(mp->m_quotainfo);
···
 		}
 	} else {
 		flags |= XFS_QMOPT_SBVERSION;
-		sbflags |= (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
-			    XFS_SB_GQUOTINO | XFS_SB_PQUOTINO |
-			    XFS_SB_QFLAGS);
 	}
 
 	/*
···
 	 */
 	if (XFS_IS_UQUOTA_ON(mp) && uip == NULL) {
 		error = xfs_qm_qino_alloc(mp, &uip,
-					      sbflags | XFS_SB_UQUOTINO,
 					      flags | XFS_QMOPT_UQUOTA);
 		if (error)
 			goto error_rele;
···
 	}
 	if (XFS_IS_GQUOTA_ON(mp) && gip == NULL) {
 		error = xfs_qm_qino_alloc(mp, &gip,
-					  sbflags | XFS_SB_GQUOTINO,
 					  flags | XFS_QMOPT_GQUOTA);
 		if (error)
 			goto error_rele;
···
 	}
 	if (XFS_IS_PQUOTA_ON(mp) && pip == NULL) {
 		error = xfs_qm_qino_alloc(mp, &pip,
-					  sbflags | XFS_SB_PQUOTINO,
 					  flags | XFS_QMOPT_PQUOTA);
 		if (error)
 			goto error_rele;
···
  */
 int
 xfs_qm_write_sb_changes(
-	xfs_mount_t	*mp,
-	__int64_t	flags)
+	struct xfs_mount *mp)
 {
 	xfs_trans_t	*tp;
 	int		error;
···
 		return error;
 	}
 
-	xfs_mod_sb(tp, flags);
-	error = xfs_trans_commit(tp, 0);
-
-	return error;
+	xfs_mod_sb(tp);
+	return xfs_trans_commit(tp, 0);
 }
 
 

fs/xfs/xfs_qm.h

···
 #define XFS_QM_RTBWARNLIMIT	5
 
 extern void		xfs_qm_destroy_quotainfo(struct xfs_mount *);
-extern int		xfs_qm_write_sb_changes(struct xfs_mount *, __int64_t);
+extern int		xfs_qm_write_sb_changes(struct xfs_mount *);
 
 /* dquot stuff */
 extern void		xfs_qm_dqpurge_all(struct xfs_mount *, uint);

fs/xfs/xfs_qm_syscalls.c

···
 		mutex_unlock(&q->qi_quotaofflock);
 
 		/* XXX what to do if error ? Revert back to old vals incore ? */
-		error = xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS);
-		return error;
+		return xfs_qm_write_sb_changes(mp);
 	}
 
 	dqtype = 0;
···
 {
 	int		error;
 	uint		qf;
-	__int64_t	sbflags;
 
 	flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD);
 	/*
 	 * Switching on quota accounting must be done at mount time.
 	 */
 	flags &= ~(XFS_ALL_QUOTA_ACCT);
-
-	sbflags = 0;
 
 	if (flags == 0) {
 		xfs_debug(mp, "%s: zero flags, m_qflags=%x",
···
 	/*
 	 * There's nothing to change if it's the same.
 	 */
-	if ((qf & flags) == flags && sbflags == 0)
+	if ((qf & flags) == flags)
 		return -EEXIST;
-	sbflags |= XFS_SB_QFLAGS;
 
-	if ((error = xfs_qm_write_sb_changes(mp, sbflags)))
+	if ((error = xfs_qm_write_sb_changes(mp)))
 		return error;
 	/*
 	 * If we aren't trying to switch on quota enforcement, we are done.
···
 	mp->m_sb.sb_qflags = (mp->m_qflags & ~(flags)) & XFS_MOUNT_QUOTA_ALL;
 	spin_unlock(&mp->m_sb_lock);
 
-	xfs_mod_sb(tp, XFS_SB_QFLAGS);
+	xfs_mod_sb(tp);
 
 	/*
 	 * We have to make sure that the transaction is secure on disk before we

fs/xfs/xfs_super.c

···
 		 * might have some superblock changes to update.
 		 */
 		if (mp->m_update_flags) {
-			error = xfs_mount_log_sb(mp, mp->m_update_flags);
+			error = xfs_mount_log_sb(mp);
 			if (error) {
 				xfs_warn(mp, "failed to write sb changes");
 				return error;