[PATCH 6/7] userfaultfd: report UFFDIO_ZEROPAGE as available for shmem VMAs

From: Mike Rapoport
Date: Tue Jun 20 2017 - 02:21:27 EST


Now when shmem VMAs can be filled with zero page via userfaultfd we can
report that UFFDIO_ZEROPAGE is available for those VMAs

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index f7555fc..57794c2 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1183,7 +1183,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
struct uffdio_register __user *user_uffdio_register;
unsigned long vm_flags, new_flags;
bool found;
- bool non_anon_pages;
+ bool basic_ioctls;
unsigned long start, end, vma_end;

user_uffdio_register = (struct uffdio_register __user *) arg;
@@ -1249,7 +1249,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
* Search for not compatible vmas.
*/
found = false;
- non_anon_pages = false;
+ basic_ioctls = false;
for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) {
cond_resched();

@@ -1288,8 +1288,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
/*
* Note vmas containing huge pages
*/
- if (is_vm_hugetlb_page(cur) || vma_is_shmem(cur))
- non_anon_pages = true;
+ if (is_vm_hugetlb_page(cur))
+ basic_ioctls = true;

found = true;
}
@@ -1360,7 +1360,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
* userland which ioctls methods are guaranteed to
* succeed on this range.
*/
- if (put_user(non_anon_pages ? UFFD_API_RANGE_IOCTLS_BASIC :
+ if (put_user(basic_ioctls ? UFFD_API_RANGE_IOCTLS_BASIC :
UFFD_API_RANGE_IOCTLS,
&user_uffdio_register->ioctls))
ret = -EFAULT;
--
2.7.4