+ userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte.patch added to -mm tree

+ userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte.patch added to -mm tree

[akpm]

The patch titled
     Subject: userfaultfd: shmem: wire up shmem_mfill_zeropage_pte
has been added to the -mm tree.  Its filename is
     userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Mike Rapoport <rppt@linux.vnet.ibm.com>
Subject: userfaultfd: shmem: wire up shmem_mfill_zeropage_pte

For shmem VMAs we can use shmem_mfill_zeropage_pte for UFFDIO_ZEROPAGE

Link: http://lkml.kernel.org/r/1497939652-16528-6-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>
---

 mm/userfaultfd.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff -puN mm/userfaultfd.c~userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte mm/userfaultfd.c
--- a/mm/userfaultfd.c~userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte
+++ a/mm/userfaultfd.c
@@ -389,11 +389,13 @@ static __always_inline ssize_t mfill_ato
 			err = mfill_zeropage_pte(dst_mm, dst_pmd,
 						 dst_vma, dst_addr);
 	} else {
-		err = -EINVAL; /* if zeropage is true return -EINVAL */
-		if (likely(!zeropage))
+		if (!zeropage)
 			err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd,
 						     dst_vma, dst_addr,
 						     src_addr, page);
+		else
+			err = shmem_mfill_zeropage_pte(dst_mm, dst_pmd,
+						       dst_vma, dst_addr);
 	}
 
 	return err;
_

Patches currently in -mm which might be from rppt@linux.vnet.ibm.com are

userfaultfd-non-cooperative-notify-about-unmap-of-destination-during-mremap.patch
userfaultfd_zeropage-return-enospc-in-case-mm-has-gone.patch
shmem-shmem_charge-verify-max_block-is-not-exceeded-before-inode-update.patch
shmem-introduce-shmem_inode_acct_block.patch
userfaultfd-shmem-add-shmem_mfill_zeropage_pte-for-userfaultfd-support.patch
userfaultfd-mcopy_atomic-introduce-mfill_atomic_pte-helper.patch
userfaultfd-shmem-wire-up-shmem_mfill_zeropage_pte.patch
userfaultfd-report-uffdio_zeropage-as-available-for-shmem-vmas.patch
userfaultfd-selftest-enable-testing-of-uffdio_zeropage-for-shmem.patch