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| author | Hugh Dickins <hughd@google.com> | 2018-12-01 01:10:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 21:31:57 +0300 |
| commit | d31ff4722f45560a6daf3df9d15a6b88da0e5080 (patch) | |
| tree | 64586c00e8fbdb2ba636b7ec037754fd164a8a5a /mm/percpu-internal.h | |
| parent | 7e18656c9a2c642ac8abb7b7934367fdd26f8a3f (diff) | |
| download | linux-d31ff4722f45560a6daf3df9d15a6b88da0e5080.tar.xz | |
mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
commit 006d3ff27e884f80bd7d306b041afc415f63598f upstream.
Huge tmpfs testing, on 32-bit kernel with lockdep enabled, showed that
__split_huge_page() was using i_size_read() while holding the irq-safe
lru_lock and page tree lock, but the 32-bit i_size_read() uses an
irq-unsafe seqlock which should not be nested inside them.
Instead, read the i_size earlier in split_huge_page_to_list(), and pass
the end offset down to __split_huge_page(): all while holding head page
lock, which is enough to prevent truncation of that extent before the
page tree lock has been taken.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261520070.2275@eggly.anvils
Fixes: baa355fd33142 ("thp: file pages support for split_huge_page()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'mm/percpu-internal.h')
0 files changed, 0 insertions, 0 deletions