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| author | Hugh Dickins <hughd@google.com> | 2012-04-19 10:34:46 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-04-19 10:40:57 +0400 |
| commit | 9b7f43afd417a6feb80841d30ced4051c362eb5d (patch) | |
| tree | 695f97a4d028a3463c8e7edaa4c6d410a941d0bb /mm | |
| parent | 932e9f352b5d685725076f21b237f7c7d804b29c (diff) | |
| download | linux-9b7f43afd417a6feb80841d30ced4051c362eb5d.tar.xz | |
memcg: fix Bad page state after replace_page_cache
My 9ce70c0240d0 "memcg: fix deadlock by inverting lrucare nesting" put a
nasty little bug into v3.3's version of mem_cgroup_replace_page_cache(),
sometimes used for FUSE. Replacing __mem_cgroup_commit_charge_lrucare()
by __mem_cgroup_commit_charge(), I used the "pc" pointer set up earlier:
but it's for oldpage, and needs now to be for newpage. Once oldpage was
freed, its PageCgroupUsed bit (cleared above but set again here) caused
"Bad page state" messages - and perhaps worse, being missed from newpage.
(I didn't find this by using FUSE, but in reusing the function for tmpfs.)
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org [v3.3 only]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a7165a60d0a7..b868def9bcc1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3392,6 +3392,7 @@ void mem_cgroup_replace_page_cache(struct page *oldpage, * the newpage may be on LRU(or pagevec for LRU) already. We lock * LRU while we overwrite pc->mem_cgroup. */ + pc = lookup_page_cgroup(newpage); __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true); } |