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>

1 files changed, 31 insertions, 19 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 008b3622b286..85e3b65286ac 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/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. */