From ce53e8e6f2cb02d69f0a1d7954e10d3231bc75f5 Mon Sep 17 00:00:00 2001
From: Mike Rapoport <rppt@linux.vnet.ibm.com>
Date: Wed, 6 Sep 2017 16:23:12 -0700
Subject: [PATCH] userfaultfd: report UFFDIO_ZEROPAGE as available for shmem
VMAs
Now when shmem VMAs can be filled with zero page via userfaultfd we can
report that UFFDIO_ZEROPAGE is available for those VMAs
Link: http://lkml.kernel.org/r/1497939652-16528-7-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/userfaultfd.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 886085b47c75e..01a85e2660b8d 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1194,7 +1194,7 @@ 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;
@@ -1260,7 +1260,7 @@ 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();
@@ -1299,8 +1299,8 @@ 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;
}
@@ -1371,7 +1371,7 @@ 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;
--
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