xfs: pass perag to xfs_alloc_read_agf()

xfs_alloc_read_agf() initialises the perag if it hasn't been done
yet, so it makes sense to pass it the perag rather than pull a
reference from the buffer. This allows callers to be per-ag centric
rather than passing mount/agno pairs everywhere.

Whilst modifying the xfs_reflink_find_shared() function definition,
declare it static and remove the extern declaration as it is an
internal function only these days.

Signed-off-by: Dave Chinner <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>

fs/xfs/libxfs/xfs_ag.c

···
 
 	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_read_agf(mp, NULL, index, 0, NULL);
-		if (error)
-			return error;
-
 		pag = xfs_perag_get(mp, index);
-		error = xfs_ialloc_read_agi(pag, NULL, NULL);
+		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;
···
 
 	agi = agibp->b_addr;
 
-	error = xfs_alloc_read_agf(mp, *tpp, pag->pag_agno, 0, &agfbp);
+	error = xfs_alloc_read_agf(pag, *tpp, 0, &agfbp);
 	if (error)
 		return error;
 
···
 	/*
 	 * Change agf length.
 	 */
-	error = xfs_alloc_read_agf(pag->pag_mount, tp, pag->pag_agno, 0, &bp);
+	error = xfs_alloc_read_agf(pag, tp, 0, &bp);
 	if (error)
 		return error;
 
···
 	error = xfs_ialloc_read_agi(pag, NULL, &agi_bp);
 	if (error)
 		return error;
-	error = xfs_alloc_read_agf(pag->pag_mount, NULL, pag->pag_agno, 0,
-			&agf_bp);
+	error = xfs_alloc_read_agf(pag, NULL, 0, &agf_bp);
 	if (error)
 		goto out_agi;
 

fs/xfs/libxfs/xfs_ag_resv.c

···
 	 * address.
 	 */
 	if (has_resv) {
-		error2 = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, NULL);
+		error2 = xfs_alloc_read_agf(pag, tp, 0, NULL);
 		if (error2)
 			return error2;
 

fs/xfs/libxfs/xfs_alloc.c

···
 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
 
 	if (!pag->pagf_init) {
-		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
+		error = xfs_alloc_read_agf(pag, tp, flags, &agbp);
 		if (error) {
 			/* Couldn't lock the AGF so skip this AG. */
 			if (error == -EAGAIN)
···
 	 * Can fail if we're not blocking on locks, and it's held.
 	 */
 	if (!agbp) {
-		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
+		error = xfs_alloc_read_agf(pag, tp, flags, &agbp);
 		if (error) {
 			/* Couldn't lock the AGF so skip this AG. */
 			if (error == -EAGAIN)
···
  * perag structure if necessary. If the caller provides @agfbpp, then return the
  * locked buffer to the caller, otherwise free it.
  */
-int					/* error */
+int
 xfs_alloc_read_agf(
-	struct xfs_mount	*mp,	/* mount point structure */
-	struct xfs_trans	*tp,	/* transaction pointer */
-	xfs_agnumber_t		agno,	/* allocation group number */
-	int			flags,	/* XFS_ALLOC_FLAG_... */
+	struct xfs_perag	*pag,
+	struct xfs_trans	*tp,
+	int			flags,
 	struct xfs_buf		**agfbpp)
 {
 	struct xfs_buf		*agfbp;
-	struct xfs_agf		*agf;		/* ag freelist header */
-	struct xfs_perag	*pag;		/* per allocation group data */
+	struct xfs_agf		*agf;
 	int			error;
 	int			allocbt_blks;
 
-	trace_xfs_alloc_read_agf(mp, agno);
+	trace_xfs_alloc_read_agf(pag->pag_mount, pag->pag_agno);
 
 	/* We don't support trylock when freeing. */
 	ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) !=
 			(XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK));
-	ASSERT(agno != NULLAGNUMBER);
-	error = xfs_read_agf(mp, tp, agno,
+	error = xfs_read_agf(pag->pag_mount, tp, pag->pag_agno,
 			(flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
 			&agfbp);
 	if (error)
 		return error;
 
 	agf = agfbp->b_addr;
-	pag = agfbp->b_pag;
 	if (!pag->pagf_init) {
 		pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
 		pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
···
 			be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
 		pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
 		pag->pagf_init = 1;
-		pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf);
+		pag->pagf_agflreset = xfs_agfl_needs_reset(pag->pag_mount, agf);
 
 		/*
 		 * Update the in-core allocbt counter. Filter out the rmapbt
···
 		 * counter only tracks non-root blocks.
 		 */
 		allocbt_blks = pag->pagf_btreeblks;
-		if (xfs_has_rmapbt(mp))
+		if (xfs_has_rmapbt(pag->pag_mount))
 			allocbt_blks -= be32_to_cpu(agf->agf_rmap_blocks) - 1;
 		if (allocbt_blks > 0)
-			atomic64_add(allocbt_blks, &mp->m_allocbt_blks);
+			atomic64_add(allocbt_blks,
+					&pag->pag_mount->m_allocbt_blks);
 	}
 #ifdef DEBUG
-	else if (!xfs_is_shutdown(mp)) {
+	else if (!xfs_is_shutdown(pag->pag_mount)) {
 		ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
 		ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
 		ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));

fs/xfs/libxfs/xfs_alloc.h

···
 	int		btreeblk); /* owner was a AGF btree */
 
 /*
- * Read in the allocation group header (free/alloc section).
- */
-int					/* error  */
-xfs_alloc_read_agf(
-	struct xfs_mount *mp,		/* mount point structure */
-	struct xfs_trans *tp,		/* transaction pointer */
-	xfs_agnumber_t	agno,		/* allocation group number */
-	int		flags,		/* XFS_ALLOC_FLAG_... */
-	struct xfs_buf	**bpp);		/* buffer for the ag freelist header */
-
-/*
  * Allocate an extent (variable-size).
  */
 int				/* error */
···
 
 int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
 			xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
+int xfs_alloc_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,
+		struct xfs_buf **agfbpp);
 int xfs_alloc_read_agfl(struct xfs_mount *mp, struct xfs_trans *tp,
 			xfs_agnumber_t agno, struct xfs_buf **bpp);
 int xfs_free_agfl_block(struct xfs_trans *, xfs_agnumber_t, xfs_agblock_t,

fs/xfs/libxfs/xfs_bmap.c

···
 
 	pag = xfs_perag_get(mp, ag);
 	if (!pag->pagf_init) {
-		error = xfs_alloc_read_agf(mp, tp, ag, XFS_ALLOC_FLAG_TRYLOCK,
+		error = xfs_alloc_read_agf(pag, tp, XFS_ALLOC_FLAG_TRYLOCK,
 				NULL);
 		if (error) {
 			/* Couldn't lock the AGF, so skip this AG. */

fs/xfs/libxfs/xfs_ialloc.c

···
 		return false;
 
 	if (!pag->pagf_init) {
-		error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, flags, NULL);
+		error = xfs_alloc_read_agf(pag, tp, flags, NULL);
 		if (error)
 			return false;
 	}

fs/xfs/libxfs/xfs_refcount.c

···
 		*pcur = NULL;
 	}
 	if (rcur == NULL) {
-		error = xfs_alloc_read_agf(tp->t_mountp, tp, pag->pag_agno,
-				XFS_ALLOC_FLAG_FREEING, &agbp);
+		error = xfs_alloc_read_agf(pag, tp, XFS_ALLOC_FLAG_FREEING,
+				&agbp);
 		if (error)
 			goto out_drop;
 
···
 	if (error)
 		return error;
 
-	error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, &agbp);
+	error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
 	if (error)
 		goto out_trans;
 	cur = xfs_refcountbt_init_cursor(mp, tp, agbp, pag);

fs/xfs/libxfs/xfs_refcount_btree.c

···
 	if (!xfs_has_reflink(mp))
 		return 0;
 
-	error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, &agbp);
+	error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
 	if (error)
 		return error;
 

fs/xfs/libxfs/xfs_rmap_btree.c

···
 	if (!xfs_has_rmapbt(mp))
 		return 0;
 
-	error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, &agbp);
+	error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
 	if (error)
 		return error;
 

fs/xfs/scrub/agheader_repair.c

···
 	 * nothing wrong with the AGF, but all the AG header repair functions
 	 * have this chicken-and-egg problem.
 	 */
-	error = xfs_alloc_read_agf(mp, sc->tp, sc->sa.pag->pag_agno, 0,
-			&agf_bp);
+	error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
 	if (error)
 		return error;
 
···
 	int				error;
 
 	/* Read the AGF. */
-	error = xfs_alloc_read_agf(mp, sc->tp, sc->sa.pag->pag_agno, 0,
-			&agf_bp);
+	error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
 	if (error)
 		return error;
 

fs/xfs/scrub/bmap.c

···
 	struct xfs_buf			*agf;
 	int				error;
 
-	error = xfs_alloc_read_agf(sc->mp, sc->tp, pag->pag_agno, 0, &agf);
+	error = xfs_alloc_read_agf(pag, sc->tp, 0, &agf);
 	if (error)
 		return error;
 

fs/xfs/scrub/common.c

···
 	if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGI))
 		return error;
 
-	error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, &sa->agf_bp);
+	error = xfs_alloc_read_agf(sa->pag, sc->tp, 0, &sa->agf_bp);
 	if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGF))
 		return error;
 

fs/xfs/scrub/fscounters.c

···
 		error = xfs_ialloc_read_agi(pag, sc->tp, &agi_bp);
 		if (error)
 			break;
-		error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, &agf_bp);
+		error = xfs_alloc_read_agf(pag, sc->tp, 0, &agf_bp);
 		if (error)
 			break;
 

fs/xfs/scrub/repair.c

···
 	}
 
 	/* Now grab the block counters from the AGF. */
-	error = xfs_alloc_read_agf(mp, NULL, sm->sm_agno, 0, &bp);
+	error = xfs_alloc_read_agf(pag, NULL, 0, &bp);
 	if (error) {
 		aglen = xfs_ag_block_count(mp, sm->sm_agno);
 		freelen = aglen;
···
 
 	agno = XFS_FSB_TO_AGNO(sc->mp, fsbno);
 	agbno = XFS_FSB_TO_AGBNO(sc->mp, fsbno);
+	ASSERT(agno == sc->sa.pag->pag_agno);
 
 	/*
 	 * If we are repairing per-inode metadata, we need to read in the AGF
···
 	 * the AGF buffer that the setup functions already grabbed.
 	 */
 	if (sc->ip) {
-		error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf_bp);
+		error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
 		if (error)
 			return error;
 	} else {

fs/xfs/xfs_discard.c

···
 	 */
 	xfs_log_force(mp, XFS_LOG_SYNC);
 
-	error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp);
+	error = xfs_alloc_read_agf(pag, NULL, 0, &agbp);
 	if (error)
 		goto out_put_perag;
 	agf = agbp->b_addr;

fs/xfs/xfs_extfree_item.c

···
 #include "xfs_bit.h"
 #include "xfs_shared.h"
 #include "xfs_mount.h"
+#include "xfs_ag.h"
 #include "xfs_defer.h"
 #include "xfs_trans.h"
 #include "xfs_trans_priv.h"
···
 	xfs_agnumber_t			agno;
 	xfs_agblock_t			agbno;
 	uint				next_extent;
+	struct xfs_perag		*pag;
 
 	free = container_of(item, struct xfs_extent_free_item, xefi_list);
 	ASSERT(free->xefi_blockcount == 1);
···
 
 	trace_xfs_agfl_free_deferred(mp, agno, 0, agbno, free->xefi_blockcount);
 
-	error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
+	pag = xfs_perag_get(mp, agno);
+	error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
 	if (!error)
 		error = xfs_free_agfl_block(tp, agno, agbno, agbp, &oinfo);
+	xfs_perag_put(pag);
 
 	/*
 	 * Mark the transaction dirty, even on error. This ensures the

fs/xfs/xfs_filestream.c

···
 		pag = xfs_perag_get(mp, ag);
 
 		if (!pag->pagf_init) {
-			err = xfs_alloc_read_agf(mp, NULL, ag, trylock, NULL);
+			err = xfs_alloc_read_agf(pag, NULL, trylock, NULL);
 			if (err) {
 				if (err != -EAGAIN) {
 					xfs_perag_put(pag);

fs/xfs/xfs_fsmap.c

···
 			info->agf_bp = NULL;
 		}
 
-		error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0,
-				&info->agf_bp);
+		error = xfs_alloc_read_agf(pag, tp, 0, &info->agf_bp);
 		if (error)
 			break;
 

fs/xfs/xfs_reflink.c

···
  * shared blocks.  If there are no shared extents, fbno and flen will
  * be set to NULLAGBLOCK and 0, respectively.
  */
-int
+static int
 xfs_reflink_find_shared(
-	struct xfs_mount	*mp,
+	struct xfs_perag	*pag,
 	struct xfs_trans	*tp,
-	xfs_agnumber_t		agno,
 	xfs_agblock_t		agbno,
 	xfs_extlen_t		aglen,
 	xfs_agblock_t		*fbno,
···
 	struct xfs_btree_cur	*cur;
 	int			error;
 
-	error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
+	error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
 	if (error)
 		return error;
 
-	cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agbp->b_pag);
+	cur = xfs_refcountbt_init_cursor(pag->pag_mount, tp, agbp, pag);
 
 	error = xfs_refcount_find_shared(cur, agbno, aglen, fbno, flen,
 			find_end_of_shared);
···
 	struct xfs_bmbt_irec	*irec,
 	bool			*shared)
 {
-	xfs_agnumber_t		agno;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_perag	*pag;
 	xfs_agblock_t		agbno;
 	xfs_extlen_t		aglen;
 	xfs_agblock_t		fbno;
···
 
 	trace_xfs_reflink_trim_around_shared(ip, irec);
 
-	agno = XFS_FSB_TO_AGNO(ip->i_mount, irec->br_startblock);
-	agbno = XFS_FSB_TO_AGBNO(ip->i_mount, irec->br_startblock);
+	pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, irec->br_startblock));
+	agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
 	aglen = irec->br_blockcount;
 
-	error = xfs_reflink_find_shared(ip->i_mount, NULL, agno, agbno,
-			aglen, &fbno, &flen, true);
+	error = xfs_reflink_find_shared(pag, NULL, agbno, aglen, &fbno, &flen,
+			true);
+	xfs_perag_put(pag);
 	if (error)
 		return error;
 
···
 	struct xfs_bmbt_irec		got;
 	struct xfs_mount		*mp = ip->i_mount;
 	struct xfs_ifork		*ifp;
-	xfs_agnumber_t			agno;
-	xfs_agblock_t			agbno;
-	xfs_extlen_t			aglen;
-	xfs_agblock_t			rbno;
-	xfs_extlen_t			rlen;
 	struct xfs_iext_cursor		icur;
 	bool				found;
 	int				error;
···
 	*has_shared = false;
 	found = xfs_iext_lookup_extent(ip, ifp, 0, &icur, &got);
 	while (found) {
+		struct xfs_perag	*pag;
+		xfs_agblock_t		agbno;
+		xfs_extlen_t		aglen;
+		xfs_agblock_t		rbno;
+		xfs_extlen_t		rlen;
+
 		if (isnullstartblock(got.br_startblock) ||
 		    got.br_state != XFS_EXT_NORM)
 			goto next;
-		agno = XFS_FSB_TO_AGNO(mp, got.br_startblock);
+
+		pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, got.br_startblock));
 		agbno = XFS_FSB_TO_AGBNO(mp, got.br_startblock);
 		aglen = got.br_blockcount;
-
-		error = xfs_reflink_find_shared(mp, tp, agno, agbno, aglen,
+		error = xfs_reflink_find_shared(pag, tp, agbno, aglen,
 				&rbno, &rlen, false);
+		xfs_perag_put(pag);
 		if (error)
 			return error;
+
 		/* Is there still a shared block here? */
 		if (rbno != NULLAGBLOCK) {
 			*has_shared = true;

fs/xfs/xfs_reflink.h

···
 	return xfs_is_reflink_inode(ip) || xfs_is_always_cow_inode(ip);
 }
 
-extern int xfs_reflink_find_shared(struct xfs_mount *mp, struct xfs_trans *tp,
-		xfs_agnumber_t agno, xfs_agblock_t agbno, xfs_extlen_t aglen,
-		xfs_agblock_t *fbno, xfs_extlen_t *flen, bool find_maximal);
 extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip,
 		struct xfs_bmbt_irec *irec, bool *shared);
 int xfs_bmap_trim_cow(struct xfs_inode *ip, struct xfs_bmbt_irec *imap,