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| author | Minchan Kim <minchan@kernel.org> | 2016-04-28 16:18:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-04-28 19:34:04 -0700 |
| commit | b06bad17c7435b600a1d7a35b56eff25e1d3dbc0 (patch) | |
| tree | b75e803dfc71fb95ec67cba0cc17876ca48942f9 /mm/page_io.c | |
| parent | 7bf52fb891b64b8d61caf0b82060adb9db761aec (diff) | |
| download | lwn-b06bad17c7435b600a1d7a35b56eff25e1d3dbc0.tar.gz lwn-b06bad17c7435b600a1d7a35b56eff25e1d3dbc0.zip | |
mm: call swap_slot_free_notify() with page lock held
Kyeongdon reported below error which is BUG_ON(!PageSwapCache(page)) in
page_swap_info. The reason is that page_endio in rw_page unlocks the
page if read I/O is completed so we need to hold a PG_lock again to
check PageSwapCache. Otherwise, the page can be removed from swapcache.
Kernel BUG at c00f9040 [verbose debug info unavailable]
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 4 PID: 13446 Comm: RenderThread Tainted: G W 3.10.84-g9f14aec-dirty #73
task: c3b73200 ti: dd192000 task.ti: dd192000
PC is at page_swap_info+0x10/0x2c
LR is at swap_slot_free_notify+0x18/0x6c
pc : [<c00f9040>] lr : [<c00f5560>] psr: 400f0113
sp : dd193d78 ip : c2deb1e4 fp : da015180
r10: 00000000 r9 : 000200da r8 : c120fe08
r7 : 00000000 r6 : 00000000 r5 : c249a6c0 r4 : = c249a6c0
r3 : 00000000 r2 : 40080009 r1 : 200f0113 r0 : = c249a6c0
..<snip> ..
Call Trace:
page_swap_info+0x10/0x2c
swap_slot_free_notify+0x18/0x6c
swap_readpage+0x90/0x11c
read_swap_cache_async+0x134/0x1ac
swapin_readahead+0x70/0xb0
handle_pte_fault+0x320/0x6fc
handle_mm_fault+0xc0/0xf0
do_page_fault+0x11c/0x36c
do_DataAbort+0x34/0x118
Fixes: 3f2b1a04f44933f2 ("zram: revive swap_slot_free_notify")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Tested-by: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_io.c')
| -rw-r--r-- | mm/page_io.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/page_io.c b/mm/page_io.c index cd92e3d67a32..985f23cfa79b 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -353,7 +353,11 @@ int swap_readpage(struct page *page) ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); if (!ret) { - swap_slot_free_notify(page); + if (trylock_page(page)) { + swap_slot_free_notify(page); + unlock_page(page); + } + count_vm_event(PSWPIN); return 0; } |