Michal Hocko [off-list ref] writes:

On Fri 16-03-12 23:09:22, Aneesh Kumar K.V wrote:

quoted

From: "Aneesh Kumar K.V" <redacted>

Using VM_FAULT_* codes with ERR_PTR will require us to make sure
VM_FAULT_* values will not exceed MAX_ERRNO value.

Signed-off-by: Aneesh Kumar K.V <redacted>
---
 mm/hugetlb.c |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d623e71..3782da8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c

[...]

quoted

@@ -1047,7 +1047,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
 		page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
 		if (!page) {
 			hugetlb_put_quota(inode->i_mapping, chg);
-			return ERR_PTR(-VM_FAULT_SIGBUS);
+			return ERR_PTR(-ENOSPC);

Hmm, so one error code abuse replaced by another?
I know that ENOMEM would revert 4a6018f7 which would be unfortunate but
ENOSPC doesn't feel right as well.

File systems do map ENOSPC to SIGBUS. block_page_mkwrite_return() does
that.

-aneesh