Re: [PATCH 15/22] xfs: use perag for ialloc btree cursors

[Brian Foster <bfoster@redhat.com>]

On Thu, May 06, 2021 at 05:20:47PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/libxfs/xfs_ialloc.c       | 177 ++++++++++++++++---------------
>  fs/xfs/libxfs/xfs_ialloc_btree.c |  27 ++---
>  fs/xfs/libxfs/xfs_ialloc_btree.h |   6 +-
>  fs/xfs/scrub/agheader_repair.c   |   4 +-
>  fs/xfs/scrub/common.c            |   5 +-
>  fs/xfs/xfs_iwalk.c               |   6 +-
>  6 files changed, 109 insertions(+), 116 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
> index 905872bab426..e6f64d41e208 100644
> --- a/fs/xfs/libxfs/xfs_ialloc.c
> +++ b/fs/xfs/libxfs/xfs_ialloc.c
> @@ -172,18 +172,17 @@ xfs_inobt_insert(
>  	struct xfs_mount	*mp,
>  	struct xfs_trans	*tp,
>  	struct xfs_buf		*agbp,
> +	struct xfs_perag	*pag,
>  	xfs_agino_t		newino,
>  	xfs_agino_t		newlen,
>  	xfs_btnum_t		btnum)
>  {
>  	struct xfs_btree_cur	*cur;
> -	struct xfs_agi		*agi = agbp->b_addr;
> -	xfs_agnumber_t		agno = be32_to_cpu(agi->agi_seqno);
>  	xfs_agino_t		thisino;
>  	int			i;
>  	int			error;
>  
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, btnum);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, btnum);
>  
>  	for (thisino = newino;
>  	     thisino < newino + newlen;
> @@ -520,18 +519,17 @@ xfs_inobt_insert_sprec(
>  	struct xfs_mount		*mp,
>  	struct xfs_trans		*tp,
>  	struct xfs_buf			*agbp,
> +	struct xfs_perag		*pag,
>  	int				btnum,
>  	struct xfs_inobt_rec_incore	*nrec,	/* in/out: new/merged rec. */
>  	bool				merge)	/* merge or replace */
>  {
>  	struct xfs_btree_cur		*cur;
> -	struct xfs_agi			*agi = agbp->b_addr;
> -	xfs_agnumber_t			agno = be32_to_cpu(agi->agi_seqno);
>  	int				error;
>  	int				i;
>  	struct xfs_inobt_rec_incore	rec;
>  
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, btnum);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, btnum);
>  
>  	/* the new record is pre-aligned so we know where to look */
>  	error = xfs_inobt_lookup(cur, nrec->ir_startino, XFS_LOOKUP_EQ, &i);
> @@ -578,14 +576,14 @@ xfs_inobt_insert_sprec(
>  			goto error;
>  		}
>  
> -		trace_xfs_irec_merge_pre(mp, agno, rec.ir_startino,
> +		trace_xfs_irec_merge_pre(mp, pag->pag_agno, rec.ir_startino,
>  					 rec.ir_holemask, nrec->ir_startino,
>  					 nrec->ir_holemask);
>  
>  		/* merge to nrec to output the updated record */
>  		__xfs_inobt_rec_merge(nrec, &rec);
>  
> -		trace_xfs_irec_merge_post(mp, agno, nrec->ir_startino,
> +		trace_xfs_irec_merge_post(mp, pag->pag_agno, nrec->ir_startino,
>  					  nrec->ir_holemask);
>  
>  		error = xfs_inobt_rec_check_count(mp, nrec);
> @@ -613,21 +611,20 @@ xfs_inobt_insert_sprec(
>  STATIC int
>  xfs_ialloc_ag_alloc(
>  	struct xfs_trans	*tp,
> -	struct xfs_buf		*agbp)
> +	struct xfs_buf		*agbp,
> +	struct xfs_perag	*pag)
>  {
>  	struct xfs_agi		*agi;
>  	struct xfs_alloc_arg	args;
> -	xfs_agnumber_t		agno;
>  	int			error;
>  	xfs_agino_t		newino;		/* new first inode's number */
>  	xfs_agino_t		newlen;		/* new number of inodes */
>  	int			isaligned = 0;	/* inode allocation at stripe */
>  						/* unit boundary */
>  	/* init. to full chunk */
> -	uint16_t		allocmask = (uint16_t) -1;
>  	struct xfs_inobt_rec_incore rec;
> -	struct xfs_perag	*pag;
>  	struct xfs_ino_geometry	*igeo = M_IGEO(tp->t_mountp);
> +	uint16_t		allocmask = (uint16_t) -1;
>  	int			do_sparse = 0;
>  
>  	memset(&args, 0, sizeof(args));
> @@ -660,14 +657,13 @@ xfs_ialloc_ag_alloc(
>  	 */
>  	agi = agbp->b_addr;
>  	newino = be32_to_cpu(agi->agi_newino);
> -	agno = be32_to_cpu(agi->agi_seqno);
>  	args.agbno = XFS_AGINO_TO_AGBNO(args.mp, newino) +
>  		     igeo->ialloc_blks;
>  	if (do_sparse)
>  		goto sparse_alloc;
>  	if (likely(newino != NULLAGINO &&
>  		  (args.agbno < be32_to_cpu(agi->agi_length)))) {
> -		args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
> +		args.fsbno = XFS_AGB_TO_FSB(args.mp, pag->pag_agno, args.agbno);
>  		args.type = XFS_ALLOCTYPE_THIS_BNO;
>  		args.prod = 1;
>  
> @@ -727,7 +723,7 @@ xfs_ialloc_ag_alloc(
>  		 * For now, just allocate blocks up front.
>  		 */
>  		args.agbno = be32_to_cpu(agi->agi_root);
> -		args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
> +		args.fsbno = XFS_AGB_TO_FSB(args.mp, pag->pag_agno, args.agbno);
>  		/*
>  		 * Allocate a fixed-size extent of inodes.
>  		 */
> @@ -748,7 +744,7 @@ xfs_ialloc_ag_alloc(
>  	if (isaligned && args.fsbno == NULLFSBLOCK) {
>  		args.type = XFS_ALLOCTYPE_NEAR_BNO;
>  		args.agbno = be32_to_cpu(agi->agi_root);
> -		args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
> +		args.fsbno = XFS_AGB_TO_FSB(args.mp, pag->pag_agno, args.agbno);
>  		args.alignment = igeo->cluster_align;
>  		if ((error = xfs_alloc_vextent(&args)))
>  			return error;
> @@ -764,7 +760,7 @@ xfs_ialloc_ag_alloc(
>  sparse_alloc:
>  		args.type = XFS_ALLOCTYPE_NEAR_BNO;
>  		args.agbno = be32_to_cpu(agi->agi_root);
> -		args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
> +		args.fsbno = XFS_AGB_TO_FSB(args.mp, pag->pag_agno, args.agbno);
>  		args.alignment = args.mp->m_sb.sb_spino_align;
>  		args.prod = 1;
>  
> @@ -809,7 +805,7 @@ xfs_ialloc_ag_alloc(
>  	 * rather than a linear progression to prevent the next generation
>  	 * number from being easily guessable.
>  	 */
> -	error = xfs_ialloc_inode_init(args.mp, tp, NULL, newlen, agno,
> +	error = xfs_ialloc_inode_init(args.mp, tp, NULL, newlen, pag->pag_agno,
>  			args.agbno, args.len, prandom_u32());
>  
>  	if (error)
> @@ -836,12 +832,12 @@ xfs_ialloc_ag_alloc(
>  		 * if necessary. If a merge does occur, rec is updated to the
>  		 * merged record.
>  		 */
> -		error = xfs_inobt_insert_sprec(args.mp, tp, agbp, XFS_BTNUM_INO,
> -					       &rec, true);
> +		error = xfs_inobt_insert_sprec(args.mp, tp, agbp, pag,
> +				XFS_BTNUM_INO, &rec, true);
>  		if (error == -EFSCORRUPTED) {
>  			xfs_alert(args.mp,
>  	"invalid sparse inode record: ino 0x%llx holemask 0x%x count %u",
> -				  XFS_AGINO_TO_INO(args.mp, agno,
> +				  XFS_AGINO_TO_INO(args.mp, pag->pag_agno,
>  						   rec.ir_startino),
>  				  rec.ir_holemask, rec.ir_count);
>  			xfs_force_shutdown(args.mp, SHUTDOWN_CORRUPT_INCORE);
> @@ -861,21 +857,20 @@ xfs_ialloc_ag_alloc(
>  		 * existing record with this one.
>  		 */
>  		if (xfs_sb_version_hasfinobt(&args.mp->m_sb)) {
> -			error = xfs_inobt_insert_sprec(args.mp, tp, agbp,
> -						       XFS_BTNUM_FINO, &rec,
> -						       false);
> +			error = xfs_inobt_insert_sprec(args.mp, tp, agbp, pag,
> +				       XFS_BTNUM_FINO, &rec, false);
>  			if (error)
>  				return error;
>  		}
>  	} else {
>  		/* full chunk - insert new records to both btrees */
> -		error = xfs_inobt_insert(args.mp, tp, agbp, newino, newlen,
> +		error = xfs_inobt_insert(args.mp, tp, agbp, pag, newino, newlen,
>  					 XFS_BTNUM_INO);
>  		if (error)
>  			return error;
>  
>  		if (xfs_sb_version_hasfinobt(&args.mp->m_sb)) {
> -			error = xfs_inobt_insert(args.mp, tp, agbp, newino,
> +			error = xfs_inobt_insert(args.mp, tp, agbp, pag, newino,
>  						 newlen, XFS_BTNUM_FINO);
>  			if (error)
>  				return error;
> @@ -887,7 +882,6 @@ xfs_ialloc_ag_alloc(
>  	 */
>  	be32_add_cpu(&agi->agi_count, newlen);
>  	be32_add_cpu(&agi->agi_freecount, newlen);
> -	pag = agbp->b_pag;
>  	pag->pagi_freecount += newlen;
>  	pag->pagi_count += newlen;
>  	agi->agi_newino = cpu_to_be32(newino);
> @@ -1123,15 +1117,14 @@ STATIC int
>  xfs_dialloc_ag_inobt(
>  	struct xfs_trans	*tp,
>  	struct xfs_buf		*agbp,
> +	struct xfs_perag	*pag,
>  	xfs_ino_t		parent,
>  	xfs_ino_t		*inop)
>  {
>  	struct xfs_mount	*mp = tp->t_mountp;
>  	struct xfs_agi		*agi = agbp->b_addr;
> -	xfs_agnumber_t		agno = be32_to_cpu(agi->agi_seqno);
>  	xfs_agnumber_t		pagno = XFS_INO_TO_AGNO(mp, parent);
>  	xfs_agino_t		pagino = XFS_INO_TO_AGINO(mp, parent);
> -	struct xfs_perag	*pag = agbp->b_pag;
>  	struct xfs_btree_cur	*cur, *tcur;
>  	struct xfs_inobt_rec_incore rec, trec;
>  	xfs_ino_t		ino;
> @@ -1145,7 +1138,7 @@ xfs_dialloc_ag_inobt(
>  	ASSERT(pag->pagi_freecount > 0);
>  
>   restart_pagno:
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, XFS_BTNUM_INO);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_INO);
>  	/*
>  	 * If pagino is 0 (this is the root inode allocation) use newino.
>  	 * This must work because we've just allocated some.
> @@ -1160,7 +1153,7 @@ xfs_dialloc_ag_inobt(
>  	/*
>  	 * If in the same AG as the parent, try to get near the parent.
>  	 */
> -	if (pagno == agno) {
> +	if (pagno == pag->pag_agno) {
>  		int		doneleft;	/* done, to the left */
>  		int		doneright;	/* done, to the right */
>  
> @@ -1363,7 +1356,7 @@ xfs_dialloc_ag_inobt(
>  	ASSERT(offset < XFS_INODES_PER_CHUNK);
>  	ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
>  				   XFS_INODES_PER_CHUNK) == 0);
> -	ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
> +	ino = XFS_AGINO_TO_INO(mp, pag->pag_agno, rec.ir_startino + offset);
>  	rec.ir_free &= ~XFS_INOBT_MASK(offset);
>  	rec.ir_freecount--;
>  	error = xfs_inobt_update(cur, &rec);
> @@ -1577,7 +1570,6 @@ xfs_dialloc_ag(
>  {
>  	struct xfs_mount		*mp = tp->t_mountp;
>  	struct xfs_agi			*agi = agbp->b_addr;
> -	xfs_agnumber_t			agno = be32_to_cpu(agi->agi_seqno);
>  	xfs_agnumber_t			pagno = XFS_INO_TO_AGNO(mp, parent);
>  	xfs_agino_t			pagino = XFS_INO_TO_AGINO(mp, parent);
>  	struct xfs_btree_cur		*cur;	/* finobt cursor */
> @@ -1587,9 +1579,10 @@ xfs_dialloc_ag(
>  	int				error;
>  	int				offset;
>  	int				i;
> +	struct xfs_perag		*pag = agbp->b_pag;
>  
>  	if (!xfs_sb_version_hasfinobt(&mp->m_sb))
> -		return xfs_dialloc_ag_inobt(tp, agbp, parent, inop);
> +		return xfs_dialloc_ag_inobt(tp, agbp, pag, parent, inop);
>  
>  	/*
>  	 * If pagino is 0 (this is the root inode allocation) use newino.
> @@ -1598,7 +1591,7 @@ xfs_dialloc_ag(
>  	if (!pagino)
>  		pagino = be32_to_cpu(agi->agi_newino);
>  
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, XFS_BTNUM_FINO);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_FINO);
>  
>  	error = xfs_check_agi_freecount(cur, agi);
>  	if (error)
> @@ -1609,7 +1602,7 @@ xfs_dialloc_ag(
>  	 * parent. If so, find the closest available inode to the parent. If
>  	 * not, consider the agi hint or find the first free inode in the AG.
>  	 */
> -	if (agno == pagno)
> +	if (pag->pag_agno == pagno)
>  		error = xfs_dialloc_ag_finobt_near(pagino, &cur, &rec);
>  	else
>  		error = xfs_dialloc_ag_finobt_newino(agi, cur, &rec);
> @@ -1621,7 +1614,7 @@ xfs_dialloc_ag(
>  	ASSERT(offset < XFS_INODES_PER_CHUNK);
>  	ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
>  				   XFS_INODES_PER_CHUNK) == 0);
> -	ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
> +	ino = XFS_AGINO_TO_INO(mp, pag->pag_agno, rec.ir_startino + offset);
>  
>  	/*
>  	 * Modify or remove the finobt record.
> @@ -1641,7 +1634,7 @@ xfs_dialloc_ag(
>  	 * the original freecount. If all is well, make the equivalent update to
>  	 * the inobt using the finobt record and offset information.
>  	 */
> -	icur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, XFS_BTNUM_INO);
> +	icur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_INO);
>  
>  	error = xfs_check_agi_freecount(icur, agi);
>  	if (error)
> @@ -1657,7 +1650,7 @@ xfs_dialloc_ag(
>  	 */
>  	be32_add_cpu(&agi->agi_freecount, -1);
>  	xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
> -	agbp->b_pag->pagi_freecount--;
> +	pag->pagi_freecount--;
>  
>  	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
>  
> @@ -1809,7 +1802,7 @@ xfs_dialloc_select_ag(
>  		if (!okalloc)
>  			goto nextag_relse_buffer;
>  
> -		error = xfs_ialloc_ag_alloc(*tpp, agbp);
> +		error = xfs_ialloc_ag_alloc(*tpp, agbp, pag);
>  		if (error < 0) {
>  			xfs_trans_brelse(*tpp, agbp);
>  
> @@ -1935,12 +1928,12 @@ xfs_difree_inobt(
>  	struct xfs_mount		*mp,
>  	struct xfs_trans		*tp,
>  	struct xfs_buf			*agbp,
> +	struct xfs_perag		*pag,
>  	xfs_agino_t			agino,
>  	struct xfs_icluster		*xic,
>  	struct xfs_inobt_rec_incore	*orec)
>  {
>  	struct xfs_agi			*agi = agbp->b_addr;
> -	xfs_agnumber_t			agno = be32_to_cpu(agi->agi_seqno);
>  	struct xfs_btree_cur		*cur;
>  	struct xfs_inobt_rec_incore	rec;
>  	int				ilen;
> @@ -1954,7 +1947,7 @@ xfs_difree_inobt(
>  	/*
>  	 * Initialize the cursor.
>  	 */
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, XFS_BTNUM_INO);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_INO);
>  
>  	error = xfs_check_agi_freecount(cur, agi);
>  	if (error)
> @@ -2005,7 +1998,8 @@ xfs_difree_inobt(
>  		struct xfs_perag	*pag = agbp->b_pag;
>  
>  		xic->deleted = true;
> -		xic->first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
> +		xic->first_ino = XFS_AGINO_TO_INO(mp, pag->pag_agno,
> +				rec.ir_startino);
>  		xic->alloc = xfs_inobt_irec_to_allocmask(&rec);
>  
>  		/*
> @@ -2028,7 +2022,7 @@ xfs_difree_inobt(
>  			goto error0;
>  		}
>  
> -		xfs_difree_inode_chunk(tp, agno, &rec);
> +		xfs_difree_inode_chunk(tp, pag->pag_agno, &rec);
>  	} else {
>  		xic->deleted = false;
>  
> @@ -2044,7 +2038,7 @@ xfs_difree_inobt(
>  		 */
>  		be32_add_cpu(&agi->agi_freecount, 1);
>  		xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
> -		agbp->b_pag->pagi_freecount++;
> +		pag->pagi_freecount++;
>  		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
>  	}
>  
> @@ -2069,18 +2063,18 @@ xfs_difree_finobt(
>  	struct xfs_mount		*mp,
>  	struct xfs_trans		*tp,
>  	struct xfs_buf			*agbp,
> +	struct xfs_perag		*pag,
>  	xfs_agino_t			agino,
>  	struct xfs_inobt_rec_incore	*ibtrec) /* inobt record */
>  {
>  	struct xfs_agi			*agi = agbp->b_addr;
> -	xfs_agnumber_t			agno = be32_to_cpu(agi->agi_seqno);
>  	struct xfs_btree_cur		*cur;
>  	struct xfs_inobt_rec_incore	rec;
>  	int				offset = agino - ibtrec->ir_startino;
>  	int				error;
>  	int				i;
>  
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, XFS_BTNUM_FINO);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_FINO);
>  
>  	error = xfs_inobt_lookup(cur, ibtrec->ir_startino, XFS_LOOKUP_EQ, &i);
>  	if (error)
> @@ -2188,16 +2182,15 @@ xfs_difree(
>  	xfs_agino_t		agino;	/* allocation group inode number */
>  	xfs_agnumber_t		agno;	/* allocation group number */
>  	int			error;	/* error return value */
> -	struct xfs_mount	*mp;	/* mount structure for filesystem */
> +	struct xfs_mount	*mp = tp->t_mountp;
>  	struct xfs_inobt_rec_incore rec;/* btree record */
> -
> -	mp = tp->t_mountp;
> +	struct xfs_perag	*pag;
>  
>  	/*
>  	 * Break up inode number into its components.
>  	 */
>  	agno = XFS_INO_TO_AGNO(mp, inode);
> -	if (agno >= mp->m_sb.sb_agcount)  {
> +	if (agno >= mp->m_sb.sb_agcount) {
>  		xfs_warn(mp, "%s: agno >= mp->m_sb.sb_agcount (%d >= %d).",
>  			__func__, agno, mp->m_sb.sb_agcount);
>  		ASSERT(0);
> @@ -2231,7 +2224,8 @@ xfs_difree(
>  	/*
>  	 * Fix up the inode allocation btree.
>  	 */
> -	error = xfs_difree_inobt(mp, tp, agbp, agino, xic, &rec);
> +	pag = agbp->b_pag;
> +	error = xfs_difree_inobt(mp, tp, agbp, pag, agino, xic, &rec);
>  	if (error)
>  		goto error0;
>  
> @@ -2239,7 +2233,7 @@ xfs_difree(
>  	 * Fix up the free inode btree.
>  	 */
>  	if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
> -		error = xfs_difree_finobt(mp, tp, agbp, agino, &rec);
> +		error = xfs_difree_finobt(mp, tp, agbp, pag, agino, &rec);
>  		if (error)
>  			goto error0;
>  	}
> @@ -2254,7 +2248,7 @@ STATIC int
>  xfs_imap_lookup(
>  	struct xfs_mount	*mp,
>  	struct xfs_trans	*tp,
> -	xfs_agnumber_t		agno,
> +	struct xfs_perag	*pag,
>  	xfs_agino_t		agino,
>  	xfs_agblock_t		agbno,
>  	xfs_agblock_t		*chunk_agbno,
> @@ -2267,11 +2261,11 @@ xfs_imap_lookup(
>  	int			error;
>  	int			i;
>  
> -	error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
> +	error = xfs_ialloc_read_agi(mp, tp, pag->pag_agno, &agbp);
>  	if (error) {
>  		xfs_alert(mp,
>  			"%s: xfs_ialloc_read_agi() returned error %d, agno %d",
> -			__func__, error, agno);
> +			__func__, error, pag->pag_agno);
>  		return error;
>  	}
>  
> @@ -2281,7 +2275,7 @@ xfs_imap_lookup(
>  	 * we have a record, we need to ensure it contains the inode number
>  	 * we are looking up.
>  	 */
> -	cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, NULL, XFS_BTNUM_INO);
> +	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_INO);
>  	error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &i);
>  	if (!error) {
>  		if (i)
> @@ -2315,42 +2309,44 @@ xfs_imap_lookup(
>   */
>  int
>  xfs_imap(
> -	xfs_mount_t	 *mp,	/* file system mount structure */
> -	xfs_trans_t	 *tp,	/* transaction pointer */
> -	xfs_ino_t	ino,	/* inode to locate */
> -	struct xfs_imap	*imap,	/* location map structure */
> -	uint		flags)	/* flags for inode btree lookup */
> +	struct xfs_mount	 *mp,	/* file system mount structure */
> +	struct xfs_trans	 *tp,	/* transaction pointer */
> +	xfs_ino_t		ino,	/* inode to locate */
> +	struct xfs_imap		*imap,	/* location map structure */
> +	uint			flags)	/* flags for inode btree lookup */
>  {
> -	xfs_agblock_t	agbno;	/* block number of inode in the alloc group */
> -	xfs_agino_t	agino;	/* inode number within alloc group */
> -	xfs_agnumber_t	agno;	/* allocation group number */
> -	xfs_agblock_t	chunk_agbno;	/* first block in inode chunk */
> -	xfs_agblock_t	cluster_agbno;	/* first block in inode cluster */
> -	int		error;	/* error code */
> -	int		offset;	/* index of inode in its buffer */
> -	xfs_agblock_t	offset_agbno;	/* blks from chunk start to inode */
> +	xfs_agblock_t		agbno;	/* block number of inode in the alloc group */
> +	xfs_agino_t		agino;	/* inode number within alloc group */
> +	xfs_agblock_t		chunk_agbno;	/* first block in inode chunk */
> +	xfs_agblock_t		cluster_agbno;	/* first block in inode cluster */
> +	int			error;	/* error code */
> +	int			offset;	/* index of inode in its buffer */
> +	xfs_agblock_t		offset_agbno;	/* blks from chunk start to inode */
> +	struct xfs_perag	*pag;
>  
>  	ASSERT(ino != NULLFSINO);
>  
>  	/*
>  	 * Split up the inode number into its parts.
>  	 */
> -	agno = XFS_INO_TO_AGNO(mp, ino);
> +	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
>  	agino = XFS_INO_TO_AGINO(mp, ino);
>  	agbno = XFS_AGINO_TO_AGBNO(mp, agino);
> -	if (agno >= mp->m_sb.sb_agcount || agbno >= mp->m_sb.sb_agblocks ||
> -	    ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
> +	if (!pag || agbno >= mp->m_sb.sb_agblocks ||
> +	    ino != XFS_AGINO_TO_INO(mp, pag->pag_agno, agino)) {
> +		error = -EINVAL;
>  #ifdef DEBUG
>  		/*
>  		 * Don't output diagnostic information for untrusted inodes
>  		 * as they can be invalid without implying corruption.
>  		 */
>  		if (flags & XFS_IGET_UNTRUSTED)
> -			return -EINVAL;
> -		if (agno >= mp->m_sb.sb_agcount) {
> +			goto out_drop;
> +		if (!pag) {
>  			xfs_alert(mp,
>  				"%s: agno (%d) >= mp->m_sb.sb_agcount (%d)",
> -				__func__, agno, mp->m_sb.sb_agcount);
> +				__func__, XFS_INO_TO_AGNO(mp, ino),
> +				mp->m_sb.sb_agcount);
>  		}
>  		if (agbno >= mp->m_sb.sb_agblocks) {
>  			xfs_alert(mp,
> @@ -2358,15 +2354,15 @@ xfs_imap(
>  				__func__, (unsigned long long)agbno,
>  				(unsigned long)mp->m_sb.sb_agblocks);
>  		}
> -		if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
> +		if (pag && ino != XFS_AGINO_TO_INO(mp, pag->pag_agno, agino)) {
>  			xfs_alert(mp,
>  		"%s: ino (0x%llx) != XFS_AGINO_TO_INO() (0x%llx)",
>  				__func__, ino,
> -				XFS_AGINO_TO_INO(mp, agno, agino));
> +				XFS_AGINO_TO_INO(mp, pag->pag_agno, agino));
>  		}
>  		xfs_stack_trace();
>  #endif /* DEBUG */
> -		return -EINVAL;
> +		goto out_drop;
>  	}
>  
>  	/*
> @@ -2377,10 +2373,10 @@ xfs_imap(
>  	 * in all cases where an untrusted inode number is passed.
>  	 */
>  	if (flags & XFS_IGET_UNTRUSTED) {
> -		error = xfs_imap_lookup(mp, tp, agno, agino, agbno,
> +		error = xfs_imap_lookup(mp, tp, pag, agino, agbno,
>  					&chunk_agbno, &offset_agbno, flags);
>  		if (error)
> -			return error;
> +			goto out_drop;
>  		goto out_map;
>  	}
>  
> @@ -2392,11 +2388,12 @@ xfs_imap(
>  		offset = XFS_INO_TO_OFFSET(mp, ino);
>  		ASSERT(offset < mp->m_sb.sb_inopblock);
>  
> -		imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, agbno);
> +		imap->im_blkno = XFS_AGB_TO_DADDR(mp, pag->pag_agno, agbno);
>  		imap->im_len = XFS_FSB_TO_BB(mp, 1);
>  		imap->im_boffset = (unsigned short)(offset <<
>  							mp->m_sb.sb_inodelog);
> -		return 0;
> +		error = 0;
> +		goto out_drop;
>  	}
>  
>  	/*
> @@ -2408,10 +2405,10 @@ xfs_imap(
>  		offset_agbno = agbno & M_IGEO(mp)->inoalign_mask;
>  		chunk_agbno = agbno - offset_agbno;
>  	} else {
> -		error = xfs_imap_lookup(mp, tp, agno, agino, agbno,
> +		error = xfs_imap_lookup(mp, tp, pag, agino, agbno,
>  					&chunk_agbno, &offset_agbno, flags);
>  		if (error)
> -			return error;
> +			goto out_drop;
>  	}
>  
>  out_map:
> @@ -2422,7 +2419,7 @@ xfs_imap(
>  	offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
>  		XFS_INO_TO_OFFSET(mp, ino);
>  
> -	imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, cluster_agbno);
> +	imap->im_blkno = XFS_AGB_TO_DADDR(mp, pag->pag_agno, cluster_agbno);
>  	imap->im_len = XFS_FSB_TO_BB(mp, M_IGEO(mp)->blocks_per_cluster);
>  	imap->im_boffset = (unsigned short)(offset << mp->m_sb.sb_inodelog);
>  
> @@ -2439,9 +2436,13 @@ xfs_imap(
>  			__func__, (unsigned long long) imap->im_blkno,
>  			(unsigned long long) imap->im_len,
>  			XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
> -		return -EINVAL;
> +		error = -EINVAL;
> +		goto out_drop;
>  	}
> -	return 0;
> +	error = 0;
> +out_drop:
> +	xfs_perag_put(pag);
> +	return error;
>  }
>  
>  /*
> diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
> index 6c4efdf01674..450161b53648 100644
> --- a/fs/xfs/libxfs/xfs_ialloc_btree.c
> +++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
> @@ -35,8 +35,7 @@ xfs_inobt_dup_cursor(
>  	struct xfs_btree_cur	*cur)
>  {
>  	return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
> -			cur->bc_ag.agbp, cur->bc_ag.agno,
> -			cur->bc_ag.pag, cur->bc_btnum);
> +			cur->bc_ag.agbp, cur->bc_ag.pag, cur->bc_btnum);
>  }
>  
>  STATIC void
> @@ -428,7 +427,6 @@ static struct xfs_btree_cur *
>  xfs_inobt_init_common(
>  	struct xfs_mount	*mp,		/* file system mount point */
>  	struct xfs_trans	*tp,		/* transaction pointer */
> -	xfs_agnumber_t		agno,		/* allocation group number */
>  	struct xfs_perag	*pag,
>  	xfs_btnum_t		btnum)		/* ialloc or free ino btree */
>  {
> @@ -451,12 +449,10 @@ xfs_inobt_init_common(
>  	if (xfs_sb_version_hascrc(&mp->m_sb))
>  		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
>  
> -	cur->bc_ag.agno = agno;
> -	if (pag) {
> -		/* take a reference for the cursor */
> -		atomic_inc(&pag->pag_ref);
> -	}
> +	/* take a reference for the cursor */
> +	atomic_inc(&pag->pag_ref);
>  	cur->bc_ag.pag = pag;
> +	cur->bc_ag.agno = pag->pag_agno;
>  	return cur;
>  }
>  
> @@ -466,14 +462,13 @@ xfs_inobt_init_cursor(
>  	struct xfs_mount	*mp,
>  	struct xfs_trans	*tp,
>  	struct xfs_buf		*agbp,
> -	xfs_agnumber_t		agno,
>  	struct xfs_perag	*pag,
>  	xfs_btnum_t		btnum)
>  {
>  	struct xfs_btree_cur	*cur;
>  	struct xfs_agi		*agi = agbp->b_addr;
>  
> -	cur = xfs_inobt_init_common(mp, tp, agno, pag, btnum);
> +	cur = xfs_inobt_init_common(mp, tp, pag, btnum);
>  	if (btnum == XFS_BTNUM_INO)
>  		cur->bc_nlevels = be32_to_cpu(agi->agi_level);
>  	else
> @@ -487,12 +482,12 @@ struct xfs_btree_cur *
>  xfs_inobt_stage_cursor(
>  	struct xfs_mount	*mp,
>  	struct xbtree_afakeroot	*afake,
> -	xfs_agnumber_t		agno,
> +	struct xfs_perag	*pag,
>  	xfs_btnum_t		btnum)
>  {
>  	struct xfs_btree_cur	*cur;
>  
> -	cur = xfs_inobt_init_common(mp, NULL, agno, NULL, btnum);
> +	cur = xfs_inobt_init_common(mp, NULL, pag, btnum);
>  	xfs_btree_stage_afakeroot(cur, afake);
>  	return cur;
>  }
> @@ -664,7 +659,7 @@ int
>  xfs_inobt_cur(
>  	struct xfs_mount	*mp,
>  	struct xfs_trans	*tp,
> -	xfs_agnumber_t		agno,
> +	struct xfs_perag	*pag,
>  	xfs_btnum_t		which,
>  	struct xfs_btree_cur	**curpp,
>  	struct xfs_buf		**agi_bpp)
> @@ -675,11 +670,11 @@ xfs_inobt_cur(
>  	ASSERT(*agi_bpp == NULL);
>  	ASSERT(*curpp == NULL);
>  
> -	error = xfs_ialloc_read_agi(mp, tp, agno, agi_bpp);
> +	error = xfs_ialloc_read_agi(mp, tp, pag->pag_agno, agi_bpp);
>  	if (error)
>  		return error;
>  
> -	cur = xfs_inobt_init_cursor(mp, tp, *agi_bpp, agno, NULL, which);
> +	cur = xfs_inobt_init_cursor(mp, tp, *agi_bpp, pag, which);
>  	*curpp = cur;
>  	return 0;
>  }
> @@ -696,7 +691,7 @@ xfs_inobt_count_blocks(
>  	struct xfs_btree_cur	*cur = NULL;
>  	int			error;
>  
> -	error = xfs_inobt_cur(mp, tp, pag->pag_agno, btnum, &cur, &agbp);
> +	error = xfs_inobt_cur(mp, tp, pag, btnum, &cur, &agbp);
>  	if (error)
>  		return error;
>  
> diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.h b/fs/xfs/libxfs/xfs_ialloc_btree.h
> index 04dfa7eee81f..e530c82b2217 100644
> --- a/fs/xfs/libxfs/xfs_ialloc_btree.h
> +++ b/fs/xfs/libxfs/xfs_ialloc_btree.h
> @@ -47,10 +47,10 @@ struct xfs_perag;
>  		 ((index) - 1) * sizeof(xfs_inobt_ptr_t)))
>  
>  extern struct xfs_btree_cur *xfs_inobt_init_cursor(struct xfs_mount *mp,
> -		struct xfs_trans *tp, struct xfs_buf *agbp, xfs_agnumber_t agno,
> +		struct xfs_trans *tp, struct xfs_buf *agbp,
>  		struct xfs_perag *pag, xfs_btnum_t btnum);
>  struct xfs_btree_cur *xfs_inobt_stage_cursor(struct xfs_mount *mp,
> -		struct xbtree_afakeroot *afake, xfs_agnumber_t agno,
> +		struct xbtree_afakeroot *afake, struct xfs_perag *pag,
>  		xfs_btnum_t btnum);
>  extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
>  
> @@ -69,7 +69,7 @@ int xfs_finobt_calc_reserves(struct xfs_mount *mp, struct xfs_trans *tp,
>  extern xfs_extlen_t xfs_iallocbt_calc_size(struct xfs_mount *mp,
>  		unsigned long long len);
>  int xfs_inobt_cur(struct xfs_mount *mp, struct xfs_trans *tp,
> -		xfs_agnumber_t agno, xfs_btnum_t btnum,
> +		struct xfs_perag *pag, xfs_btnum_t btnum,
>  		struct xfs_btree_cur **curpp, struct xfs_buf **agi_bpp);
>  
>  void xfs_inobt_commit_staged_btree(struct xfs_btree_cur *cur,
> diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
> index ee2d85e3fd4a..ecc9146647ba 100644
> --- a/fs/xfs/scrub/agheader_repair.c
> +++ b/fs/xfs/scrub/agheader_repair.c
> @@ -806,7 +806,7 @@ xrep_agi_calc_from_btrees(
>  	xfs_agino_t		freecount;
>  	int			error;
>  
> -	cur = xfs_inobt_init_cursor(mp, sc->tp, agi_bp, sc->sa.agno,
> +	cur = xfs_inobt_init_cursor(mp, sc->tp, agi_bp,
>  			sc->sa.pag, XFS_BTNUM_INO);
>  	error = xfs_ialloc_count_inodes(cur, &count, &freecount);
>  	if (error)
> @@ -828,7 +828,7 @@ xrep_agi_calc_from_btrees(
>  	    xfs_sb_version_hasinobtcounts(&mp->m_sb)) {
>  		xfs_agblock_t	blocks;
>  
> -		cur = xfs_inobt_init_cursor(mp, sc->tp, agi_bp, sc->sa.agno,
> +		cur = xfs_inobt_init_cursor(mp, sc->tp, agi_bp,
>  				sc->sa.pag, XFS_BTNUM_FINO);
>  		error = xfs_btree_count_blocks(cur, &blocks);
>  		if (error)
> diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
> index 3035f8cee6f6..64c3b9b78d0d 100644
> --- a/fs/xfs/scrub/common.c
> +++ b/fs/xfs/scrub/common.c
> @@ -458,7 +458,6 @@ xchk_ag_btcur_init(
>  	struct xchk_ag		*sa)
>  {
>  	struct xfs_mount	*mp = sc->mp;
> -	xfs_agnumber_t		agno = sa->agno;
>  
>  	xchk_perag_get(sc->mp, sa);
>  	if (sa->agf_bp &&
> @@ -479,14 +478,14 @@ xchk_ag_btcur_init(
>  	if (sa->agi_bp &&
>  	    xchk_ag_btree_healthy_enough(sc, sa->pag, XFS_BTNUM_INO)) {
>  		sa->ino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,
> -				agno, sa->pag, XFS_BTNUM_INO);
> +				sa->pag, XFS_BTNUM_INO);
>  	}
>  
>  	/* Set up a finobt cursor for cross-referencing. */
>  	if (sa->agi_bp && xfs_sb_version_hasfinobt(&mp->m_sb) &&
>  	    xchk_ag_btree_healthy_enough(sc, sa->pag, XFS_BTNUM_FINO)) {
>  		sa->fino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,
> -				agno, sa->pag, XFS_BTNUM_FINO);
> +				sa->pag, XFS_BTNUM_FINO);
>  	}
>  
>  	/* Set up a rmapbt cursor for cross-referencing. */
> diff --git a/fs/xfs/xfs_iwalk.c b/fs/xfs/xfs_iwalk.c
> index c7e8f48a3ec4..917d51eefee3 100644
> --- a/fs/xfs/xfs_iwalk.c
> +++ b/fs/xfs/xfs_iwalk.c
> @@ -272,8 +272,7 @@ xfs_iwalk_ag_start(
>  
>  	/* Set up a fresh cursor and empty the inobt cache. */
>  	iwag->nr_recs = 0;
> -	error = xfs_inobt_cur(mp, tp, pag->pag_agno, XFS_BTNUM_INO,
> -				curpp, agi_bpp);
> +	error = xfs_inobt_cur(mp, tp, pag, XFS_BTNUM_INO, curpp, agi_bpp);
>  	if (error)
>  		return error;
>  
> @@ -378,8 +377,7 @@ xfs_iwalk_run_callbacks(
>  		return 0;
>  
>  	/* ...and recreate the cursor just past where we left off. */
> -	error = xfs_inobt_cur(mp, tp, iwag->pag->pag_agno, XFS_BTNUM_INO,
> -				curpp, agi_bpp);
> +	error = xfs_inobt_cur(mp, tp, iwag->pag, XFS_BTNUM_INO, curpp, agi_bpp);
>  	if (error)
>  		return error;
>  
> -- 
> 2.31.1
>