xfs: replace xfs_ag_block_count() with perag accesses

Many of the places that call xfs_ag_block_count() have a perag
available. These places can just read pag->block_count directly
instead of calculating the AG block count from first principles.
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_ialloc_btree.c

@@ -683,10 +683,10 @@ xfs_inobt_rec_check_count(
 
 static xfs_extlen_t
 xfs_inobt_max_size(
-	struct xfs_mount	*mp,
-	xfs_agnumber_t		agno)
+	struct xfs_perag	*pag)
 {
-	xfs_agblock_t		agblocks = xfs_ag_block_count(mp, agno);
+	struct xfs_mount	*mp = pag->pag_mount;
+	xfs_agblock_t		agblocks = pag->block_count;
 
 	/* Bail out if we're uninitialized, which can happen in mkfs. */
 	if (M_IGEO(mp)->inobt_mxr[0] == 0)
@@ -698,7 +698,7 @@ xfs_inobt_max_size(
 	 * expansion.  We therefore can pretend the space isn't there.
 	 */
 	if (mp->m_sb.sb_logstart &&
-	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == agno)
+	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == pag->pag_agno)
 		agblocks -= mp->m_sb.sb_logblocks;
 
 	return xfs_btree_calc_size(M_IGEO(mp)->inobt_mnr,
@@ -800,7 +800,7 @@ xfs_finobt_calc_reserves(
 	if (error)
 		return error;
 
-	*ask += xfs_inobt_max_size(mp, pag->pag_agno);
+	*ask += xfs_inobt_max_size(pag);
 	*used += tree_len;
 	return 0;
 }

fs/xfs/scrub/agheader_repair.c

@@ -198,8 +198,7 @@ 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(sc->sa.pag->pag_agno);
-	agf->agf_length = cpu_to_be32(xfs_ag_block_count(mp,
-							sc->sa.pag->pag_agno));
+	agf->agf_length = cpu_to_be32(sc->sa.pag->block_count);
 	agf->agf_flfirst = old_agf->agf_flfirst;
 	agf->agf_fllast = old_agf->agf_fllast;
 	agf->agf_flcount = old_agf->agf_flcount;
@@ -777,8 +776,7 @@ 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(sc->sa.pag->pag_agno);
-	agi->agi_length = cpu_to_be32(xfs_ag_block_count(mp,
-							sc->sa.pag->pag_agno));
+	agi->agi_length = cpu_to_be32(sc->sa.pag->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

@@ -209,7 +209,7 @@ xrep_calc_ag_resblks(
 	/* Now grab the block counters from the AGF. */
 	error = xfs_alloc_read_agf(pag, NULL, 0, &bp);
 	if (error) {
-		aglen = xfs_ag_block_count(mp, sm->sm_agno);
+		aglen = pag->block_count;
 		freelen = aglen;
 		usedlen = aglen;
 	} else {
@@ -226,16 +226,16 @@ xrep_calc_ag_resblks(
 	    !xfs_verify_agino(pag, icount)) {
 		icount = pag->agino_max - pag->agino_min + 1;
 	}
-	xfs_perag_put(pag);
 
 	/* If the block counts are impossible, make worst-case assumptions. */
 	if (aglen == NULLAGBLOCK ||
-	    aglen != xfs_ag_block_count(mp, sm->sm_agno) ||
+	    aglen != pag->block_count ||
 	    freelen >= aglen) {
-		aglen = xfs_ag_block_count(mp, sm->sm_agno);
+		aglen = pag->block_count;
 		freelen = aglen;
 		usedlen = aglen;
 	}
+	xfs_perag_put(pag);
 
 	trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen,
 			freelen, usedlen);