Commit fb993fa1a2f669215fa03a09eed7848f2663e336
Committed by
Linus Torvalds
1 parent
bc127bda37
Exists in
ti-lsk-linux-4.1.y
and in
10 other branches
mm: frontswap: invalidate expired data on a dup-store failure
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> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 3 additions and 1 deletions Side-by-side Diff
mm/frontswap.c
... | ... | @@ -244,8 +244,10 @@ |
244 | 244 | the (older) page from frontswap |
245 | 245 | */ |
246 | 246 | inc_frontswap_failed_stores(); |
247 | - if (dup) | |
247 | + if (dup) { | |
248 | 248 | __frontswap_clear(sis, offset); |
249 | + frontswap_ops->invalidate_page(type, offset); | |
250 | + } | |
249 | 251 | } |
250 | 252 | if (frontswap_writethrough_enabled) |
251 | 253 | /* report failure so swap also writes to swap device */ |