xfs: make last AG grow/shrink perag centric

Because the perag must exist for these operations, look it up as
part of the common shrink operations and pass it instead of the
mount/agno pair.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_ag.c

@@ -761,11 +761,11 @@ xfs_ag_init_headers(
 
 int
 xfs_ag_shrink_space(
-	struct xfs_mount	*mp,
+	struct xfs_perag	*pag,
 	struct xfs_trans	**tpp,
-	xfs_agnumber_t		agno,
 	xfs_extlen_t		delta)
 {
+	struct xfs_mount	*mp = pag->pag_mount;
 	struct xfs_alloc_arg	args = {
 		.tp	= *tpp,
 		.mp	= mp,
@@ -782,14 +782,14 @@ xfs_ag_shrink_space(
 	xfs_agblock_t		aglen;
 	int			error, err2;
 
-	ASSERT(agno == mp->m_sb.sb_agcount - 1);
-	error = xfs_ialloc_read_agi(mp, *tpp, agno, &agibp);
+	ASSERT(pag->pag_agno == mp->m_sb.sb_agcount - 1);
+	error = xfs_ialloc_read_agi(mp, *tpp, pag->pag_agno, &agibp);
 	if (error)
 		return error;
 
 	agi = agibp->b_addr;
 
-	error = xfs_alloc_read_agf(mp, *tpp, agno, 0, &agfbp);
+	error = xfs_alloc_read_agf(mp, *tpp, pag->pag_agno, 0, &agfbp);
 	if (error)
 		return error;
 
@@ -801,13 +801,14 @@ xfs_ag_shrink_space(
 	if (delta >= aglen)
 		return -EINVAL;
 
-	args.fsbno = XFS_AGB_TO_FSB(mp, agno, aglen - delta);
+	args.fsbno = XFS_AGB_TO_FSB(mp, pag->pag_agno, aglen - delta);
 
 	/*
 	 * Make sure that the last inode cluster cannot overlap with the new
 	 * end of the AG, even if it's sparse.
 	 */
-	error = xfs_ialloc_check_shrink(*tpp, agno, agibp, aglen - delta);
+	error = xfs_ialloc_check_shrink(*tpp, pag->pag_agno, agibp,
+			aglen - delta);
 	if (error)
 		return error;
 
@@ -883,9 +884,8 @@ xfs_ag_shrink_space(
  */
 int
 xfs_ag_extend_space(
-	struct xfs_mount	*mp,
+	struct xfs_perag	*pag,
 	struct xfs_trans	*tp,
-	struct aghdr_init_data	*id,
 	xfs_extlen_t		len)
 {
 	struct xfs_buf		*bp;
@@ -893,23 +893,20 @@ xfs_ag_extend_space(
 	struct xfs_agf		*agf;
 	int			error;
 
-	/*
-	 * Change the agi length.
-	 */
-	error = xfs_ialloc_read_agi(mp, tp, id->agno, &bp);
+	ASSERT(pag->pag_agno == pag->pag_mount->m_sb.sb_agcount - 1);
+
+	error = xfs_ialloc_read_agi(pag->pag_mount, tp, pag->pag_agno, &bp);
 	if (error)
 		return error;
 
 	agi = bp->b_addr;
 	be32_add_cpu(&agi->agi_length, len);
-	ASSERT(id->agno == mp->m_sb.sb_agcount - 1 ||
-	       be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
 	xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
 
 	/*
 	 * Change agf length.
 	 */
-	error = xfs_alloc_read_agf(mp, tp, id->agno, 0, &bp);
+	error = xfs_alloc_read_agf(pag->pag_mount, tp, pag->pag_agno, 0, &bp);
 	if (error)
 		return error;
 
@@ -924,13 +921,12 @@ xfs_ag_extend_space(
 	 * XFS_RMAP_OINFO_SKIP_UPDATE is used here to tell the rmap btree that
 	 * this doesn't actually exist in the rmap btree.
 	 */
-	error = xfs_rmap_free(tp, bp, bp->b_pag,
-				be32_to_cpu(agf->agf_length) - len,
+	error = xfs_rmap_free(tp, bp, pag, be32_to_cpu(agf->agf_length) - len,
 				len, &XFS_RMAP_OINFO_SKIP_UPDATE);
 	if (error)
 		return error;
 
-	return  xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, id->agno,
+	return  xfs_free_extent(tp, XFS_AGB_TO_FSB(pag->pag_mount, pag->pag_agno,
 					be32_to_cpu(agf->agf_length) - len),
 				len, &XFS_RMAP_OINFO_SKIP_UPDATE,
 				XFS_AG_RESV_NONE);
@@ -939,34 +935,29 @@ xfs_ag_extend_space(
 /* Retrieve AG geometry. */
 int
 xfs_ag_get_geometry(
-	struct xfs_mount	*mp,
-	xfs_agnumber_t		agno,
+	struct xfs_perag	*pag,
 	struct xfs_ag_geometry	*ageo)
 {
 	struct xfs_buf		*agi_bp;
 	struct xfs_buf		*agf_bp;
 	struct xfs_agi		*agi;
 	struct xfs_agf		*agf;
-	struct xfs_perag	*pag;
 	unsigned int		freeblks;
 	int			error;
 
-	if (agno >= mp->m_sb.sb_agcount)
-		return -EINVAL;
-
 	/* Lock the AG headers. */
-	error = xfs_ialloc_read_agi(mp, NULL, agno, &agi_bp);
+	error = xfs_ialloc_read_agi(pag->pag_mount, NULL, pag->pag_agno,
+			&agi_bp);
 	if (error)
 		return error;
-	error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agf_bp);
+	error = xfs_alloc_read_agf(pag->pag_mount, NULL, pag->pag_agno, 0,
+			&agf_bp);
 	if (error)
 		goto out_agi;
 
-	pag = agi_bp->b_pag;
-
 	/* Fill out form. */
 	memset(ageo, 0, sizeof(*ageo));
-	ageo->ag_number = agno;
+	ageo->ag_number = pag->pag_agno;
 
 	agi = agi_bp->b_addr;
 	ageo->ag_icount = be32_to_cpu(agi->agi_count);

fs/xfs/libxfs/xfs_ag.h

@@ -168,11 +168,10 @@ struct aghdr_init_data {
 };
 
 int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
-int xfs_ag_shrink_space(struct xfs_mount *mp, struct xfs_trans **tpp,
-			xfs_agnumber_t agno, xfs_extlen_t delta);
-int xfs_ag_extend_space(struct xfs_mount *mp, struct xfs_trans *tp,
-			struct aghdr_init_data *id, xfs_extlen_t len);
-int xfs_ag_get_geometry(struct xfs_mount *mp, xfs_agnumber_t agno,
-			struct xfs_ag_geometry *ageo);
+int xfs_ag_shrink_space(struct xfs_perag *pag, struct xfs_trans **tpp,
+			xfs_extlen_t delta);
+int xfs_ag_extend_space(struct xfs_perag *pag, struct xfs_trans *tp,
+			xfs_extlen_t len);
+int xfs_ag_get_geometry(struct xfs_perag *pag, struct xfs_ag_geometry *ageo);
 
 #endif /* __LIBXFS_AG_H */

fs/xfs/xfs_fsops.c

@@ -41,6 +41,7 @@ xfs_resizefs_init_new_ags(
 	xfs_agnumber_t		oagcount,
 	xfs_agnumber_t		nagcount,
 	xfs_rfsblock_t		delta,
+	struct xfs_perag	*last_pag,
 	bool			*lastag_extended)
 {
 	struct xfs_mount	*mp = tp->t_mountp;
@@ -73,7 +74,7 @@ xfs_resizefs_init_new_ags(
 
 	if (delta) {
 		*lastag_extended = true;
-		error = xfs_ag_extend_space(mp, tp, id, delta);
+		error = xfs_ag_extend_space(last_pag, tp, delta);
 	}
 	return error;
 }
@@ -96,6 +97,7 @@ xfs_growfs_data_private(
 	xfs_agnumber_t		oagcount;
 	struct xfs_trans	*tp;
 	struct aghdr_init_data	id = {};
+	struct xfs_perag	*last_pag;
 
 	nb = in->newblocks;
 	error = xfs_sb_validate_fsb_count(&mp->m_sb, nb);
@@ -128,7 +130,6 @@ xfs_growfs_data_private(
 		return -EINVAL;
 
 	oagcount = mp->m_sb.sb_agcount;
-
 	/* allocate the new per-ag structures */
 	if (nagcount > oagcount) {
 		error = xfs_initialize_perag(mp, nagcount, &nagimax);
@@ -145,15 +146,17 @@ xfs_growfs_data_private(
 	if (error)
 		return error;
 
+	last_pag = xfs_perag_get(mp, oagcount - 1);
 	if (delta > 0) {
 		error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount,
-						  delta, &lastag_extended);
+				delta, last_pag, &lastag_extended);
 	} else {
 		xfs_warn_mount(mp, XFS_OPSTATE_WARNED_SHRINK,
 	"EXPERIMENTAL online shrink feature in use. Use at your own risk!");
 
-		error = xfs_ag_shrink_space(mp, &tp, nagcount - 1, -delta);
+		error = xfs_ag_shrink_space(last_pag, &tp, -delta);
 	}
+	xfs_perag_put(last_pag);
 	if (error)
 		goto out_trans_cancel;
 

fs/xfs/xfs_ioctl.c

@@ -955,6 +955,7 @@ xfs_ioc_ag_geometry(
 	struct xfs_mount	*mp,
 	void			__user *arg)
 {
+	struct xfs_perag	*pag;
 	struct xfs_ag_geometry	ageo;
 	int			error;
 
@@ -965,7 +966,12 @@ xfs_ioc_ag_geometry(
 	if (memchr_inv(&ageo.ag_reserved, 0, sizeof(ageo.ag_reserved)))
 		return -EINVAL;
 
-	error = xfs_ag_get_geometry(mp, ageo.ag_number, &ageo);
+	pag = xfs_perag_get(mp, ageo.ag_number);
+	if (!pag)
+		return -EINVAL;
+
+	error = xfs_ag_get_geometry(pag, &ageo);
+	xfs_perag_put(pag);
 	if (error)
 		return error;