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| author | Hugh Dickins <hughd@google.com> | 2018-11-30 23:10:47 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-11-30 23:56:15 +0100 |
| commit | 06a5e1268a5fb9c2b346a3da6b97e85f2eba0f07 (patch) | |
| tree | a2ccdfe76f11e07f2538884cb9c607cc90079492 /fs/ocfs2/export.c | |
| parent | mm/khugepaged: collapse_shmem() without freezing new_page (diff) | |
| download | linux-06a5e1268a5fb9c2b346a3da6b97e85f2eba0f07.tar.xz linux-06a5e1268a5fb9c2b346a3da6b97e85f2eba0f07.zip | |
mm/khugepaged: collapse_shmem() do not crash on Compound
collapse_shmem()'s VM_BUG_ON_PAGE(PageTransCompound) was unsafe: before
it holds page lock of the first page, racing truncation then extension
might conceivably have inserted a hugepage there already. Fail with the
SCAN_PAGE_COMPOUND result, instead of crashing (CONFIG_DEBUG_VM=y) or
otherwise mishandling the unexpected hugepage - though later we might
code up a more constructive way of handling it, with SCAN_SUCCESS.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261529310.2275@eggly.anvils
Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: 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>
Diffstat (limited to 'fs/ocfs2/export.c')
0 files changed, 0 insertions, 0 deletions