Merge tag 'xfs-perag-conv-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.20-mergeA

xfs: per-ag conversions for 5.20

This series drives the perag down into the AGI, AGF and AGFL access
routines and unifies the perag structure initialisation with the
high level AG header read functions. This largely replaces the
xfs_mount/agno pair that is passed to all these functions with a
perag, and in most places we already have a perag ready to pass in.
There are a few places where perags need to be grabbed before
reading the AG header buffers - some of these will need to be driven
to higher layers to ensure we can run operations on AGs without
getting stuck part way through waiting on a perag reference.

The latter section of this patchset moves some of the AG geometry
information from the xfs_mount to the xfs_perag, and starts
converting code that requires geometry validation to use a perag
instead of a mount and having to extract the AGNO from the object
location. This also allows us to store the AG size in the perag and
then we can stop having to compare the agno against sb_agcount to
determine if the AG is the last AG and so has a runt size.  This
greatly simplifies some of the type validity checking we do and
substantially reduces the CPU overhead of type validity checking. It
also cuts over 1.2kB out of the binary size.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

* tag 'xfs-perag-conv-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: make is_log_ag() a first class helper
  xfs: replace xfs_ag_block_count() with perag accesses
  xfs: Pre-calculate per-AG agino geometry
  xfs: Pre-calculate per-AG agbno geometry
  xfs: pass perag to xfs_alloc_read_agfl
  xfs: pass perag to xfs_alloc_put_freelist
  xfs: pass perag to xfs_alloc_get_freelist
  xfs: pass perag to xfs_read_agf
  xfs: pass perag to xfs_read_agi
  xfs: pass perag to xfs_alloc_read_agf()
  xfs: kill xfs_alloc_pagf_init()
  xfs: pass perag to xfs_ialloc_read_agi()
  xfs: kill xfs_ialloc_pagi_init()
  xfs: make last AG grow/shrink perag centric

Author: Darrick J. Wong

fs/xfs/libxfs/xfs_ag.c

@@ -120,18 +120,18 @@ xfs_initialize_perag_data(
 
 	for (index = 0; index < agcount; index++) {
 		/*
-		 * read the agf, then the agi. This gets us
-		 * all the information we need and populates the
-		 * per-ag structures for us.
+		 * Read the AGF and AGI buffers to populate the per-ag
+		 * structures for us.
 		 */
-		error = xfs_alloc_pagf_init(mp, NULL, index, 0);
-		if (error)
+		pag = xfs_perag_get(mp, index);
+		error = xfs_alloc_read_agf(pag, NULL, 0, NULL);
+		if (!error)
+			error = xfs_ialloc_read_agi(pag, NULL, NULL);
+		if (error) {
+			xfs_perag_put(pag);
 			return error;
+		}
 
-		error = xfs_ialloc_pagi_init(mp, NULL, index);
-		if (error)
-			return error;
-		pag = xfs_perag_get(mp, index);
 		ifree += pag->pagi_freecount;
 		ialloc += pag->pagi_count;
 		bfree += pag->pagf_freeblks;
@@ -201,10 +201,70 @@ xfs_free_perag(
 	}
 }
 
+/* Find the size of the AG, in blocks. */
+static xfs_agblock_t
+__xfs_ag_block_count(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno,
+	xfs_agnumber_t		agcount,
+	xfs_rfsblock_t		dblocks)
+{
+	ASSERT(agno < agcount);
+
+	if (agno < agcount - 1)
+		return mp->m_sb.sb_agblocks;
+	return dblocks - (agno * mp->m_sb.sb_agblocks);
+}
+
+xfs_agblock_t
+xfs_ag_block_count(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno)
+{
+	return __xfs_ag_block_count(mp, agno, mp->m_sb.sb_agcount,
+			mp->m_sb.sb_dblocks);
+}
+
+/* Calculate the first and last possible inode number in an AG. */
+static void
+__xfs_agino_range(
+	struct xfs_mount	*mp,
+	xfs_agblock_t		eoag,
+	xfs_agino_t		*first,
+	xfs_agino_t		*last)
+{
+	xfs_agblock_t		bno;
+
+	/*
+	 * Calculate the first inode, which will be in the first
+	 * cluster-aligned block after the AGFL.
+	 */
+	bno = round_up(XFS_AGFL_BLOCK(mp) + 1, M_IGEO(mp)->cluster_align);
+	*first = XFS_AGB_TO_AGINO(mp, bno);
+
+	/*
+	 * Calculate the last inode, which will be at the end of the
+	 * last (aligned) cluster that can be allocated in the AG.
+	 */
+	bno = round_down(eoag, M_IGEO(mp)->cluster_align);
+	*last = XFS_AGB_TO_AGINO(mp, bno) - 1;
+}
+
+void
+xfs_agino_range(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno,
+	xfs_agino_t		*first,
+	xfs_agino_t		*last)
+{
+	return __xfs_agino_range(mp, xfs_ag_block_count(mp, agno), first, last);
+}
+
 int
 xfs_initialize_perag(
 	struct xfs_mount	*mp,
 	xfs_agnumber_t		agcount,
+	xfs_rfsblock_t		dblocks,
 	xfs_agnumber_t		*maxagi)
 {
 	struct xfs_perag	*pag;
@@ -270,6 +330,15 @@ xfs_initialize_perag(
 		/* first new pag is fully initialized */
 		if (first_initialised == NULLAGNUMBER)
 			first_initialised = index;
+
+		/*
+		 * Pre-calculated geometry
+		 */
+		pag->block_count = __xfs_ag_block_count(mp, index, agcount,
+				dblocks);
+		pag->min_block = XFS_AGFL_BLOCK(mp);
+		__xfs_agino_range(mp, pag->block_count, &pag->agino_min,
+				&pag->agino_max);
 	}
 
 	index = xfs_set_inode_alloc(mp, agcount);
@@ -321,12 +390,6 @@ xfs_get_aghdr_buf(
 	return 0;
 }
 
-static inline bool is_log_ag(struct xfs_mount *mp, struct aghdr_init_data *id)
-{
-	return mp->m_sb.sb_logstart > 0 &&
-	       id->agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
-}
-
 /*
  * Generic btree root block init function
  */
@@ -352,7 +415,7 @@ xfs_freesp_init_recs(
 	arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
 	arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
 
-	if (is_log_ag(mp, id)) {
+	if (xfs_ag_contains_log(mp, id->agno)) {
 		struct xfs_alloc_rec	*nrec;
 		xfs_agblock_t		start = XFS_FSB_TO_AGBNO(mp,
 							mp->m_sb.sb_logstart);
@@ -479,7 +542,7 @@ xfs_rmaproot_init(
 	}
 
 	/* account for the log space */
-	if (is_log_ag(mp, id)) {
+	if (xfs_ag_contains_log(mp, id->agno)) {
 		rrec = XFS_RMAP_REC_ADDR(block,
 				be16_to_cpu(block->bb_numrecs) + 1);
 		rrec->rm_startblock = cpu_to_be32(
@@ -550,7 +613,7 @@ xfs_agfblock_init(
 		agf->agf_refcount_blocks = cpu_to_be32(1);
 	}
 
-	if (is_log_ag(mp, id)) {
+	if (xfs_ag_contains_log(mp, id->agno)) {
 		int64_t	logblocks = mp->m_sb.sb_logblocks;
 
 		be32_add_cpu(&agf->agf_freeblks, -logblocks);
@@ -761,11 +824,11 @@ 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 +845,14 @@ 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(pag, *tpp, &agibp);
 	if (error)
 		return error;
 
 	agi = agibp->b_addr;
 
-	error = xfs_alloc_read_agf(mp, *tpp, agno, 0, &agfbp);
+	error = xfs_alloc_read_agf(pag, *tpp, 0, &agfbp);
 	if (error)
 		return error;
 
@@ -801,21 +864,22 @@ 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;
 
 	/*
 	 * Disable perag reservations so it doesn't cause the allocation request
 	 * to fail. We'll reestablish reservation before we return.
 	 */
-	error = xfs_ag_resv_free(agibp->b_pag);
+	error = xfs_ag_resv_free(pag);
 	if (error)
 		return error;
 
@@ -844,7 +908,7 @@ xfs_ag_shrink_space(
 	be32_add_cpu(&agi->agi_length, -delta);
 	be32_add_cpu(&agf->agf_length, -delta);
 
-	err2 = xfs_ag_resv_init(agibp->b_pag, *tpp);
+	err2 = xfs_ag_resv_init(pag, *tpp);
 	if (err2) {
 		be32_add_cpu(&agi->agi_length, delta);
 		be32_add_cpu(&agf->agf_length, delta);
@@ -868,8 +932,9 @@ xfs_ag_shrink_space(
 	xfs_ialloc_log_agi(*tpp, agibp, XFS_AGI_LENGTH);
 	xfs_alloc_log_agf(*tpp, agfbp, XFS_AGF_LENGTH);
 	return 0;
+
 resv_init_out:
-	err2 = xfs_ag_resv_init(agibp->b_pag, *tpp);
+	err2 = xfs_ag_resv_init(pag, *tpp);
 	if (!err2)
 		return error;
 resv_err:
@@ -883,33 +948,29 @@ 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;
 	struct xfs_agi		*agi;
 	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, tp, &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, tp, 0, &bp);
 	if (error)
 		return error;
 
@@ -924,49 +985,49 @@ 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,
+	error = 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);
+	if (error)
+		return error;
+
+	/* Update perag geometry */
+	pag->block_count = be32_to_cpu(agf->agf_length);
+	__xfs_agino_range(pag->pag_mount, pag->block_count, &pag->agino_min,
+				&pag->agino_max);
+	return 0;
 }
 
 /* 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, NULL, &agi_bp);
 	if (error)
 		return error;
-	error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agf_bp);
+	error = xfs_alloc_read_agf(pag, NULL, 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);