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From:   Miaohe Lin <linmiaohe@huawei.com>
To:     <akpm@linux-foundation.org>
CC:     <hannes@cmpxchg.org>, <mhocko@suse.com>, <iamjoonsoo.kim@lge.com>,
        <vbabka@suse.cz>, <alex.shi@linux.alibaba.com>,
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        <richard.weiyang@gmail.com>, <ying.huang@intel.com>,
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        <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        <linmiaohe@huawei.com>
Subject: [PATCH 0/5] close various race windows for swap
Date:   Thu, 8 Apr 2021 09:08:15 -0400
Message-ID: <20210408130820.48233-1-linmiaohe@huawei.com>
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Hi all,
When I was investigating the swap code, I found some possible race
windows. This series aims to fix all these races. But using current
get/put_swap_device() to guard against concurrent swapoff for
swap_readpage() looks terrible because swap_readpage() may take really
long time. And to reduce the performance overhead on the hot-path as
much as possible, it appears we can use the percpu_ref to close this
race window(as suggested by Huang, Ying). The patch 1 adds percpu_ref
support for swap and the rest of the patches use this to close various
race windows. More details can be found in the respective changelogs.
Thanks!

Miaohe Lin (5):
  mm/swapfile: add percpu_ref support for swap
  swap: fix do_swap_page() race with swapoff
  mm/swap_state: fix get_shadow_from_swap_cache() race with swapoff
  mm/swap_state: fix potential faulted in race in swap_ra_info()
  mm/swap_state: fix swap_cluster_readahead() race with swapoff

 include/linux/swap.h |  4 +++-
 mm/memory.c          | 10 +++++++++
 mm/swap_state.c      | 33 +++++++++++++++++++++--------
 mm/swapfile.c        | 50 +++++++++++++++++++++++++++-----------------
 4 files changed, 68 insertions(+), 29 deletions(-)

-- 
2.19.1