xfs: introduce xfs_alloc_vextent_near_bno()

The remaining callers of xfs_alloc_vextent() are all doing NEAR_BNO
allocations. We can replace that function with a new
xfs_alloc_vextent_near_bno() function that does this explicitly.

We also multiplex NEAR_BNO allocations through
xfs_alloc_vextent_this_ag via args->type. Replace all of these with
direct calls to xfs_alloc_vextent_near_bno(), too.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_alloc.c

@@ -3479,35 +3479,47 @@ xfs_alloc_vextent_first_ag(
 }
 
 /*
- * Allocate an extent (variable-size).
- * Depending on the allocation type, we either look in a single allocation
- * group or loop over the allocation groups to find the result.
+ * Allocate an extent as close to the target as possible. If there are not
+ * viable candidates in the AG, then fail the allocation.
  */
 int
-xfs_alloc_vextent(
-	struct xfs_alloc_arg	*args)
+xfs_alloc_vextent_near_bno(
+	struct xfs_alloc_arg	*args,
+	xfs_fsblock_t		target)
 {
+	struct xfs_mount	*mp = args->mp;
+	bool			need_pag = !args->pag;
 	xfs_agnumber_t		minimum_agno = 0;
 	int			error;
 
 	if (args->tp->t_highest_agno != NULLAGNUMBER)
 		minimum_agno = args->tp->t_highest_agno;
 
-	switch (args->type) {
-	case XFS_ALLOCTYPE_THIS_AG:
-	case XFS_ALLOCTYPE_NEAR_BNO:
-	case XFS_ALLOCTYPE_THIS_BNO:
-		args->pag = xfs_perag_get(args->mp,
-				XFS_FSB_TO_AGNO(args->mp, args->fsbno));
-		error = xfs_alloc_vextent_this_ag(args);
-		xfs_perag_put(args->pag);
-		break;
-	default:
-		error = -EFSCORRUPTED;
-		ASSERT(0);
-		break;
+	error = xfs_alloc_vextent_check_args(args, target);
+	if (error) {
+		if (error == -ENOSPC)
+			return 0;
+		return error;
 	}
-	return error;
+
+	args->agno = XFS_FSB_TO_AGNO(mp, target);
+	if (minimum_agno > args->agno) {
+		trace_xfs_alloc_vextent_skip_deadlock(args);
+		return 0;
+	}
+
+	args->agbno = XFS_FSB_TO_AGBNO(mp, target);
+	args->type = XFS_ALLOCTYPE_NEAR_BNO;
+	if (need_pag)
+		args->pag = xfs_perag_get(args->mp, args->agno);
+	error = xfs_alloc_ag_vextent(args);
+	if (need_pag)
+		xfs_perag_put(args->pag);
+	if (error)
+		return error;
+
+	xfs_alloc_vextent_set_fsbno(args, minimum_agno);
+	return 0;
 }
 
 /* Ensure that the freelist is at full capacity. */

fs/xfs/libxfs/xfs_alloc.h

@@ -113,19 +113,19 @@ xfs_alloc_log_agf(
 	struct xfs_buf	*bp,	/* buffer for a.g. freelist header */
 	uint32_t	fields);/* mask of fields to be logged (XFS_AGF_...) */
 
-/*
- * Allocate an extent (variable-size).
- */
-int				/* error */
-xfs_alloc_vextent(
-	xfs_alloc_arg_t	*args);	/* allocation argument structure */
-
 /*
  * Allocate an extent in the specific AG defined by args->fsbno. If there is no
  * space in that AG, then the allocation will fail.
  */
 int xfs_alloc_vextent_this_ag(struct xfs_alloc_arg *args);
 
+/*
+ * Allocate an extent as close to the target as possible. If there are not
+ * viable candidates in the AG, then fail the allocation.
+ */
+int xfs_alloc_vextent_near_bno(struct xfs_alloc_arg *args,
+		xfs_fsblock_t target);
+
 /*
  * Best effort full filesystem allocation scan.
  *

fs/xfs/libxfs/xfs_bmap.c

@@ -3246,7 +3246,6 @@ xfs_bmap_btalloc_filestreams(
 	int			notinit = 0;
 	int			error;
 
-	args->type = XFS_ALLOCTYPE_NEAR_BNO;
 	args->total = ap->total;
 
 	start_agno = XFS_FSB_TO_AGNO(mp, ap->blkno);
@@ -3565,7 +3564,7 @@ xfs_bmap_btalloc_at_eof(
 	}
 
 	if (ag_only)
-		error = xfs_alloc_vextent(args);
+		error = xfs_alloc_vextent_near_bno(args, ap->blkno);
 	else
 		error = xfs_alloc_vextent_start_ag(args, ap->blkno);
 	if (error)
@@ -3612,7 +3611,6 @@ xfs_bmap_btalloc_best_length(
 		ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
 	}
 	xfs_bmap_adjacent(ap);
-	args->fsbno = ap->blkno;
 
 	/*
 	 * Search for an allocation group with a single extent large enough for
@@ -3653,7 +3651,7 @@ xfs_bmap_btalloc_best_length(
 	}
 
 	if (is_filestream)
-		error = xfs_alloc_vextent(args);
+		error = xfs_alloc_vextent_near_bno(args, ap->blkno);
 	else
 		error = xfs_alloc_vextent_start_ag(args, ap->blkno);
 	if (error)

fs/xfs/libxfs/xfs_ialloc.c

@@ -717,23 +717,17 @@ xfs_ialloc_ag_alloc(
 			isaligned = 1;
 		} else
 			args.alignment = igeo->cluster_align;
-		/*
-		 * Need to figure out where to allocate the inode blocks.
-		 * Ideally they should be spaced out through the a.g.
-		 * For now, just allocate blocks up front.
-		 */
-		args.agbno = be32_to_cpu(agi->agi_root);
-		args.fsbno = XFS_AGB_TO_FSB(args.mp, pag->pag_agno, args.agbno);
 		/*
 		 * Allocate a fixed-size extent of inodes.
 		 */
-		args.type = XFS_ALLOCTYPE_NEAR_BNO;
 		args.prod = 1;
 		/*
 		 * Allow space for the inode btree to split.
 		 */
 		args.minleft = igeo->inobt_maxlevels;
-		error = xfs_alloc_vextent_this_ag(&args);
+		error = xfs_alloc_vextent_near_bno(&args,
+				XFS_AGB_TO_FSB(args.mp, pag->pag_agno,
+						be32_to_cpu(agi->agi_root)));
 		if (error)
 			return error;
 	}
@@ -743,11 +737,11 @@ xfs_ialloc_ag_alloc(
 	 * alignment.
 	 */
 	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, pag->pag_agno, args.agbno);
 		args.alignment = igeo->cluster_align;
-		if ((error = xfs_alloc_vextent(&args)))
+		error = xfs_alloc_vextent_near_bno(&args,
+				XFS_AGB_TO_FSB(args.mp, pag->pag_agno,
+						be32_to_cpu(agi->agi_root)));
+		if (error)
 			return error;
 	}
 
@@ -759,9 +753,6 @@ xfs_ialloc_ag_alloc(
 	    igeo->ialloc_min_blks < igeo->ialloc_blks &&
 	    args.fsbno == NULLFSBLOCK) {
 sparse_alloc:
-		args.type = XFS_ALLOCTYPE_NEAR_BNO;
-		args.agbno = be32_to_cpu(agi->agi_root);
-		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;
 
@@ -783,7 +774,9 @@ xfs_ialloc_ag_alloc(
 					    args.mp->m_sb.sb_inoalignmt) -
 				 igeo->ialloc_blks;
 
-		error = xfs_alloc_vextent_this_ag(&args);
+		error = xfs_alloc_vextent_near_bno(&args,
+				XFS_AGB_TO_FSB(args.mp, pag->pag_agno,
+						be32_to_cpu(agi->agi_root)));
 		if (error)
 			return error;
 

fs/xfs/libxfs/xfs_ialloc_btree.c

@@ -105,14 +105,13 @@ __xfs_inobt_alloc_block(
 	args.mp = cur->bc_mp;
 	args.pag = cur->bc_ag.pag;
 	args.oinfo = XFS_RMAP_OINFO_INOBT;
-	args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_ag.pag->pag_agno, sbno);
 	args.minlen = 1;
 	args.maxlen = 1;
 	args.prod = 1;
-	args.type = XFS_ALLOCTYPE_NEAR_BNO;
 	args.resv = resv;
 
-	error = xfs_alloc_vextent_this_ag(&args);
+	error = xfs_alloc_vextent_near_bno(&args,
+			XFS_AGB_TO_FSB(args.mp, args.pag->pag_agno, sbno));
 	if (error)
 		return error;
 

fs/xfs/libxfs/xfs_refcount_btree.c

@@ -68,14 +68,13 @@ xfs_refcountbt_alloc_block(
 	args.tp = cur->bc_tp;
 	args.mp = cur->bc_mp;
 	args.pag = cur->bc_ag.pag;
-	args.type = XFS_ALLOCTYPE_NEAR_BNO;
-	args.fsbno = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_ag.pag->pag_agno,
-			xfs_refc_block(args.mp));
 	args.oinfo = XFS_RMAP_OINFO_REFC;
 	args.minlen = args.maxlen = args.prod = 1;
 	args.resv = XFS_AG_RESV_METADATA;
 
-	error = xfs_alloc_vextent_this_ag(&args);
+	error = xfs_alloc_vextent_near_bno(&args,
+			XFS_AGB_TO_FSB(args.mp, args.pag->pag_agno,
+					xfs_refc_block(args.mp)));
 	if (error)
 		goto out_error;
 	trace_xfs_refcountbt_alloc_block(cur->bc_mp, cur->bc_ag.pag->pag_agno,