[PATCH v2 4/6] mm: hugetlb: Use error variable in alloc_hugetlb_folio

[Ackerley Tng via B4 Relay]

From: Ackerley Tng <ackerleytng@xxxxxxxxxx>

Refactor alloc_hugetlb_folio to use a local variable for returning error
codes. Instead of returning ERR_PTR(-ENOSPC) at the end of the error
path, assign -ENOSPC to a return variable at each failure point and
return that variable at the end.

This allows the cleanup goto targets to be used with other errors in a
later patch.

No functional change intended.

Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
---
 mm/hugetlb.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3395de4d0999a..68c21305fc86a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2894,8 +2894,10 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
 	 */
 	if (map_chg) {
 		gbl_chg = hugepage_subpool_get_pages(spool, 1);
-		if (gbl_chg < 0)
+		if (gbl_chg < 0) {
+			ret = -ENOSPC;
 			goto out_end_reservation;
+		}
 	} else {
 		/*
 		 * If we have the vma reservation ready, no need for extra
@@ -2911,13 +2913,17 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
 	if (map_chg) {
 		ret = hugetlb_cgroup_charge_cgroup_rsvd(
 			idx, pages_per_huge_page(h), &h_cg);
-		if (ret)
+		if (ret) {
+			ret = -ENOSPC;
 			goto out_subpool_put;
+		}
 	}
 
 	ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
-	if (ret)
+	if (ret) {
+		ret = -ENOSPC;
 		goto out_uncharge_cgroup_reservation;
+	}
 
 	spin_lock_irq(&hugetlb_lock);
 
@@ -2938,6 +2944,7 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
 		folio = alloc_buddy_hugetlb_folio_with_mpol(h, mpol, nid, nodemask);
 		if (!folio) {
 			mpol_cond_put(mpol);
+			ret = -ENOSPC;
 			goto out_uncharge_cgroup;
 		}
 		spin_lock_irq(&hugetlb_lock);
@@ -3030,7 +3037,7 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
 out_end_reservation:
 	if (map_chg != MAP_CHG_ENFORCED)
 		vma_end_reservation(h, vma, addr);
-	return ERR_PTR(-ENOSPC);
+	return ERR_PTR(ret);
 }
 
 static __init void *alloc_bootmem(struct hstate *h, int nid, bool node_exact)

-- 
2.54.0.545.g6539524ca2-goog