A rare out of memory error would prevent removal of the reserve map region
for a page. hugetlb_fix_reserve_counts() handles this rare case to avoid
dangling with incorrect counts. Unfortunately, hugepage_subpool_get_pages
and hugetlb_acct_memory could possibly fail too. We should correctly handle
these cases.
Fixes: b5cec28d36f5 ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/hugetlb.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 387c9a62615e..a14bb1a03ee4 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -745,13 +745,20 @@ void hugetlb_fix_reserve_counts(struct inode *inode)
{
struct hugepage_subpool *spool = subpool_inode(inode);
long rsv_adjust;
+ bool reserved = false;
rsv_adjust = hugepage_subpool_get_pages(spool, 1);
- if (rsv_adjust) {
+ if (rsv_adjust > 0) {
struct hstate *h = hstate_inode(inode);
- hugetlb_acct_memory(h, 1);
+ if (!hugetlb_acct_memory(h, 1))
+ reserved = true;
+ } else if (!rsv_adjust) {
+ reserved = true;
}
+
+ if (!reserved)
+ pr_warn("hugetlb: Huge Page Reserved count may go negative.\n");
}
/*
--
2.19.1
