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| author | Weijie Yang <weijie.yang@samsung.com> | 2014-12-02 15:59:25 -0800 |
|---|---|---|
| committer | Chanho Park <chanho61.park@samsung.com> | 2015-12-22 13:44:14 +0900 |
| commit | eb882011a4a359434619d178c03618046f75a9a9 (patch) | |
| tree | f6cf63ec76fb0b6a2a37905da46c6bf215f756f1 /mm | |
| parent | a68e678d43f80f8a4c0b97b25e149fc04c44e19a (diff) | |
| download | linux-3.10-artik-eb882011a4a359434619d178c03618046f75a9a9.tar.gz linux-3.10-artik-eb882011a4a359434619d178c03618046f75a9a9.tar.bz2 linux-3.10-artik-eb882011a4a359434619d178c03618046f75a9a9.zip | |
mm: frontswap: invalidate expired data on a dup-store failure
commit fb993fa1a2f669215fa03a09eed7848f2663e336 upstream.
If a frontswap dup-store failed, it should invalidate the expired page
in the backend, or it could trigger some data corruption issue.
Such as:
1. use zswap as the frontswap backend with writeback feature
2. store a swap page(version_1) to entry A, success
3. dup-store a newer page(version_2) to the same entry A, fail
4. use __swap_writepage() write version_2 page to swapfile, success
5. zswap do shrink, writeback version_1 page to swapfile
6. version_2 page is overwrited by version_1, data corrupt.
This patch fixes this issue by invalidating expired data immediately
when meet a dup-store failure.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/frontswap.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/frontswap.c b/mm/frontswap.c index 1b24bdcb319..a55036a6848 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -244,8 +244,10 @@ int __frontswap_store(struct page *page) the (older) page from frontswap */ inc_frontswap_failed_stores(); - if (dup) + if (dup) { __frontswap_clear(sis, offset); + frontswap_ops->invalidate_page(type, offset); + } } if (frontswap_writethrough_enabled) /* report failure so swap also writes to swap device */ |