From:   David Stevens <stevensd@chromium.org>
To:     linux-mm@kvack.org, Peter Xu <peterx@redhat.com>,
        Matthew Wilcox <willy@infradead.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A . Shutemov" <kirill@shutemov.name>,
        Yang Shi <shy828301@gmail.com>,
        David Hildenbrand <david@redhat.com>,
        Hugh Dickins <hughd@google.com>, linux-kernel@vger.kernel.org,
        David Stevens <stevensd@chromium.org>
Subject: [PATCH v4 0/3] mm/khugepaged: fix khugepaged+shmem races
Date:   Fri, 17 Feb 2023 17:54:36 +0900
Message-Id: <20230217085439.2826375-1-stevensd@google.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: David Stevens <stevensd@chromium.org>

Fix two races in khugepaged+shmem that cause issues with userfaultfd and
lseek, respectively.

v3 -> v4:
 - Base changes on mm-everything (fba720cb4dc0)
 - Add patch to refactor error handling control flow in collapse_file
 - Rebase userfaultfd patch with no significant logic changes
 - Different approach for fixing lseek race
v2 -> v3:
 - Use XA_RETRY_ENTRY to synchronize with reads from the page cache
   under the RCU read lock in userfaultfd fix
 - Add patch to fix lseek race
v1 -> v2:
 - Different approach for userfaultfd fix

David Stevens (3):
  mm/khugepaged: refactor collapse_file control flow
  mm/khugepaged: skip shmem with userfaultfd
  mm/khugepaged: maintain page cache uptodate flag

 include/trace/events/huge_memory.h |   3 +-
 mm/khugepaged.c                    | 263 ++++++++++++++++-------------
 2 files changed, 144 insertions(+), 122 deletions(-)

-- 
2.39.2.637.g21b0678d19-goog