xfs: move the min and max group block numbers to xfs_group

Move the min and max agblock numbers to the generic xfs_group structure
so that we can start building validators for extents within an rtgroup.
While we're at it, use check_add_overflow for the extent length
computation because that has much better overflow checking.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Author: Darrick J. Wong

fs/xfs/libxfs/xfs_ag.c

@@ -205,9 +205,10 @@ xfs_update_last_ag_size(
 
 	if (!pag)
 		return -EFSCORRUPTED;
-	pag->block_count = __xfs_ag_block_count(mp, prev_agcount - 1,
-			mp->m_sb.sb_agcount, mp->m_sb.sb_dblocks);
-	__xfs_agino_range(mp, pag->block_count, &pag->agino_min,
+	pag_group(pag)->xg_block_count = __xfs_ag_block_count(mp,
+			prev_agcount - 1, mp->m_sb.sb_agcount,
+			mp->m_sb.sb_dblocks);
+	__xfs_agino_range(mp, pag_group(pag)->xg_block_count, &pag->agino_min,
 			&pag->agino_max);
 	xfs_perag_rele(pag);
 	return 0;
@@ -241,9 +242,10 @@ xfs_perag_alloc(
 	/*
 	 * Pre-calculated geometry
 	 */
-	pag->block_count = __xfs_ag_block_count(mp, index, agcount, dblocks);
-	pag->min_block = XFS_AGFL_BLOCK(mp) + 1;
-	__xfs_agino_range(mp, pag->block_count, &pag->agino_min,
+	pag_group(pag)->xg_block_count = __xfs_ag_block_count(mp, index, agcount,
+				dblocks);
+	pag_group(pag)->xg_min_gbno = XFS_AGFL_BLOCK(mp) + 1;
+	__xfs_agino_range(mp, pag_group(pag)->xg_block_count, &pag->agino_min,
 			&pag->agino_max);
 
 	error = xfs_group_insert(mp, pag_group(pag), index, XG_TYPE_AG);
@@ -852,8 +854,8 @@ xfs_ag_shrink_space(
 	}
 
 	/* Update perag geometry */
-	pag->block_count -= delta;
-	__xfs_agino_range(mp, pag->block_count, &pag->agino_min,
+	pag_group(pag)->xg_block_count -= delta;
+	__xfs_agino_range(mp, pag_group(pag)->xg_block_count, &pag->agino_min,
 			&pag->agino_max);
 
 	xfs_ialloc_log_agi(*tpp, agibp, XFS_AGI_LENGTH);
@@ -924,8 +926,8 @@ xfs_ag_extend_space(
 		return error;
 
 	/* Update perag geometry */
-	pag->block_count = be32_to_cpu(agf->agf_length);
-	__xfs_agino_range(mp, pag->block_count, &pag->agino_min,
+	pag_group(pag)->xg_block_count = be32_to_cpu(agf->agf_length);
+	__xfs_agino_range(mp, pag_group(pag)->xg_block_count, &pag->agino_min,
 			&pag->agino_max);
 	return 0;
 }

fs/xfs/libxfs/xfs_ag.h

@@ -61,8 +61,6 @@ struct xfs_perag {
 	struct xfs_ag_resv	pag_rmapbt_resv;
 
 	/* Precalculated geometry info */
-	xfs_agblock_t		block_count;
-	xfs_agblock_t		min_block;
 	xfs_agino_t		agino_min;
 	xfs_agino_t		agino_max;
 
@@ -220,11 +218,7 @@ void xfs_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,
 static inline bool
 xfs_verify_agbno(struct xfs_perag *pag, xfs_agblock_t agbno)
 {
-	if (agbno >= pag->block_count)
-		return false;
-	if (agbno < pag->min_block)
-		return false;
-	return true;
+	return xfs_verify_gbno(pag_group(pag), agbno);
 }
 
 static inline bool
@@ -233,13 +227,7 @@ xfs_verify_agbext(
 	xfs_agblock_t		agbno,
 	xfs_agblock_t		len)
 {
-	if (agbno + len <= agbno)
-		return false;
-
-	if (!xfs_verify_agbno(pag, agbno))
-		return false;
-
-	return xfs_verify_agbno(pag, agbno + len - 1);
+	return xfs_verify_gbext(pag_group(pag), agbno, len);
 }
 
 /*

fs/xfs/libxfs/xfs_group.h

@@ -12,6 +12,10 @@ struct xfs_group {
 	atomic_t		xg_ref;		/* passive reference count */
 	atomic_t		xg_active_ref;	/* active reference count */
 
+	/* Precalculated geometry info */
+	uint32_t		xg_block_count;	/* max usable gbno */
+	uint32_t		xg_min_gbno;	/* min usable gbno */
+
 #ifdef __KERNEL__
 	/* -- kernel only structures below this line -- */
 
@@ -128,4 +132,33 @@ xfs_fsb_to_gbno(
 	return fsbno & mp->m_groups[type].blkmask;
 }
 
+static inline bool
+xfs_verify_gbno(
+	struct xfs_group	*xg,
+	uint32_t		gbno)
+{
+	if (gbno >= xg->xg_block_count)
+		return false;
+	if (gbno < xg->xg_min_gbno)
+		return false;
+	return true;
+}
+
+static inline bool
+xfs_verify_gbext(
+	struct xfs_group	*xg,
+	uint32_t		gbno,
+	uint32_t		glen)
+{
+	uint32_t		end;
+
+	if (!xfs_verify_gbno(xg, gbno))
+		return false;
+	if (glen == 0 || check_add_overflow(gbno, glen - 1, &end))
+		return false;
+	if (!xfs_verify_gbno(xg, end))
+		return false;
+	return true;
+}
+
 #endif /* __LIBXFS_GROUP_H */

fs/xfs/libxfs/xfs_ialloc_btree.c

@@ -717,7 +717,7 @@ xfs_inobt_max_size(
 	struct xfs_perag	*pag)
 {
 	struct xfs_mount	*mp = pag_mount(pag);
-	xfs_agblock_t		agblocks = pag->block_count;
+	xfs_agblock_t		agblocks = pag_group(pag)->xg_block_count;
 
 	/* Bail out if we're uninitialized, which can happen in mkfs. */
 	if (M_IGEO(mp)->inobt_mxr[0] == 0)

fs/xfs/libxfs/xfs_rtgroup.c

@@ -34,6 +34,32 @@
 #include "xfs_metafile.h"
 #include "xfs_metadir.h"
 
+/* Find the first usable fsblock in this rtgroup. */
+static inline uint32_t
+xfs_rtgroup_min_block(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		rgno)
+{
+	if (xfs_has_rtsb(mp) && rgno == 0)
+		return mp->m_sb.sb_rextsize;
+
+	return 0;
+}
+
+/* Precompute this group's geometry */
+void
+xfs_rtgroup_calc_geometry(
+	struct xfs_mount	*mp,
+	struct xfs_rtgroup	*rtg,
+	xfs_rgnumber_t		rgno,
+	xfs_rgnumber_t		rgcount,
+	xfs_rtbxlen_t		rextents)
+{
+	rtg->rtg_extents = __xfs_rtgroup_extents(mp, rgno, rgcount, rextents);
+	rtg_group(rtg)->xg_block_count = rtg->rtg_extents * mp->m_sb.sb_rextsize;
+	rtg_group(rtg)->xg_min_gbno = xfs_rtgroup_min_block(mp, rgno);
+}
+
 int
 xfs_rtgroup_alloc(
 	struct xfs_mount	*mp,
@@ -48,6 +74,8 @@ xfs_rtgroup_alloc(
 	if (!rtg)
 		return -ENOMEM;
 
+	xfs_rtgroup_calc_geometry(mp, rtg, rgno, rgcount, rextents);
+
 	error = xfs_group_insert(mp, rtg_group(rtg), rgno, XG_TYPE_RTG);
 	if (error)
 		goto out_free_rtg;
@@ -149,6 +177,7 @@ xfs_update_last_rtgroup_size(
 		return -EFSCORRUPTED;
 	rtg->rtg_extents = __xfs_rtgroup_extents(mp, prev_rgcount - 1,
 			mp->m_sb.sb_rgcount, mp->m_sb.sb_rextents);
+	rtg_group(rtg)->xg_block_count = rtg->rtg_extents * mp->m_sb.sb_rextsize;
 	xfs_rtgroup_rele(rtg);
 	return 0;
 }
@@ -223,7 +252,7 @@ xfs_rtgroup_get_geometry(
 	/* Fill out form. */
 	memset(rgeo, 0, sizeof(*rgeo));
 	rgeo->rg_number = rtg_rgno(rtg);
-	rgeo->rg_length = rtg->rtg_extents * rtg_mount(rtg)->m_sb.sb_rextsize;
+	rgeo->rg_length = rtg_group(rtg)->xg_block_count;
 	xfs_rtgroup_geom_health(rtg, rgeo);
 	return 0;
 }

fs/xfs/libxfs/xfs_rtgroup.h

@@ -199,6 +199,9 @@ int xfs_initialize_rtgroups(struct xfs_mount *mp, xfs_rgnumber_t first_rgno,
 xfs_rtxnum_t __xfs_rtgroup_extents(struct xfs_mount *mp, xfs_rgnumber_t rgno,
 		xfs_rgnumber_t rgcount, xfs_rtbxlen_t rextents);
 xfs_rtxnum_t xfs_rtgroup_extents(struct xfs_mount *mp, xfs_rgnumber_t rgno);
+void xfs_rtgroup_calc_geometry(struct xfs_mount *mp, struct xfs_rtgroup *rtg,
+		xfs_rgnumber_t rgno, xfs_rgnumber_t rgcount,
+		xfs_rtbxlen_t rextents);
 
 int xfs_update_last_rtgroup_size(struct xfs_mount *mp,
 		xfs_rgnumber_t prev_rgcount);

fs/xfs/scrub/agheader.c

@@ -564,7 +564,7 @@ xchk_agf(
 
 	/* Check the AG length */
 	eoag = be32_to_cpu(agf->agf_length);
-	if (eoag != pag->block_count)
+	if (eoag != pag_group(pag)->xg_block_count)
 		xchk_block_set_corrupt(sc, sc->sa.agf_bp);
 
 	/* Check the AGF btree roots and levels */
@@ -944,7 +944,7 @@ xchk_agi(
 
 	/* Check the AG length */
 	eoag = be32_to_cpu(agi->agi_length);
-	if (eoag != pag->block_count)
+	if (eoag != pag_group(pag)->xg_block_count)
 		xchk_block_set_corrupt(sc, sc->sa.agi_bp);
 
 	/* Check btree roots and levels */

fs/xfs/scrub/agheader_repair.c

@@ -209,7 +209,7 @@ xrep_agf_init_header(
 	agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
 	agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
 	agf->agf_seqno = cpu_to_be32(pag_agno(pag));
-	agf->agf_length = cpu_to_be32(pag->block_count);
+	agf->agf_length = cpu_to_be32(pag_group(pag)->xg_block_count);
 	agf->agf_flfirst = old_agf->agf_flfirst;
 	agf->agf_fllast = old_agf->agf_fllast;
 	agf->agf_flcount = old_agf->agf_flcount;
@@ -898,7 +898,7 @@ xrep_agi_init_header(
 	agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
 	agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
 	agi->agi_seqno = cpu_to_be32(pag_agno(pag));
-	agi->agi_length = cpu_to_be32(pag->block_count);
+	agi->agi_length = cpu_to_be32(pag_group(pag)->xg_block_count);
 	agi->agi_newino = cpu_to_be32(NULLAGINO);
 	agi->agi_dirino = cpu_to_be32(NULLAGINO);
 	if (xfs_has_crc(mp))

fs/xfs/scrub/repair.c

@@ -306,7 +306,7 @@ xrep_calc_ag_resblks(
 	/* Now grab the block counters from the AGF. */
 	error = xfs_alloc_read_agf(pag, NULL, 0, &bp);
 	if (error) {
-		aglen = pag->block_count;
+		aglen = pag_group(pag)->xg_block_count;
 		freelen = aglen;
 		usedlen = aglen;
 	} else {
@@ -326,9 +326,9 @@ xrep_calc_ag_resblks(
 
 	/* If the block counts are impossible, make worst-case assumptions. */
 	if (aglen == NULLAGBLOCK ||
-	    aglen != pag->block_count ||
+	    aglen != pag_group(pag)->xg_block_count ||
 	    freelen >= aglen) {
-		aglen = pag->block_count;
+		aglen = pag_group(pag)->xg_block_count;
 		freelen = aglen;
 		usedlen = aglen;
 	}

fs/xfs/xfs_discard.c

@@ -337,7 +337,7 @@ xfs_trim_perag_extents(
 	};
 	int			error = 0;
 
-	if (start != 0 || end != pag->block_count)
+	if (start != 0 || end != pag_group(pag)->xg_block_count)
 		tcur.by_bno = true;
 
 	do {
@@ -403,7 +403,7 @@ xfs_trim_datadev_extents(
 	end_agbno = xfs_daddr_to_agbno(mp, ddev_end);
 
 	while ((pag = xfs_perag_next_range(mp, pag, start_agno, end_agno))) {
-		xfs_agblock_t	agend = pag->block_count;
+		xfs_agblock_t	agend = pag_group(pag)->xg_block_count;
 
 		if (pag_agno(pag) == end_agno)
 			agend = end_agbno;