]> git.baikalelectronics.ru Git - kernel.git/commit
hugetlb: allocate vma lock for all sharable vmas
authorMike Kravetz <mike.kravetz@oracle.com>
Wed, 5 Oct 2022 01:17:07 +0000 (18:17 -0700)
committerAndrew Morton <akpm@linux-foundation.org>
Fri, 7 Oct 2022 21:28:40 +0000 (14:28 -0700)
commitaf1a944e86929f81997d53a8a75e17c3de0906a8
tree8866b90080b9e9042eef198c6aa12d70b5c3c8ed
parenta44c2e118340fa3f6994bf6f3a3eca50a3d3dd4c
hugetlb: allocate vma lock for all sharable vmas

The hugetlb vma lock was originally designed to synchronize pmd sharing.
As such, it was only necessary to allocate the lock for vmas that were
capable of pmd sharing.  Later in the development cycle, it was discovered
that it could also be used to simplify fault/truncation races as described
in [1].  However, a subsequent change to allocate the lock for all vmas
that use the page cache was never made.  A fault/truncation race could
leave pages in a file past i_size until the file is removed.

Remove the previous restriction and allocate lock for all VM_MAYSHARE
vmas.  Warn in the unlikely event of allocation failure.

[1] https://lore.kernel.org/lkml/Yxiv0SkMkZ0JWGGp@monkey/#t

Link: https://lkml.kernel.org/r/20221005011707.514612-4-mike.kravetz@oracle.com
Fixes: "hugetlb: clean up code checking for fault/truncation races"
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/hugetlb.c