The patch titled
Subject: mm: call swap_slot_free_notify() with page lock held
has been removed from the -mm tree. Its filename was
mm-call-swap_slot_free_notify-with-holding-page-lock.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Minchan Kim <minchan@xxxxxxxxxx>
Subject: 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.
[27833.995833] ------------[ cut here ]------------
[27833.995853] Kernel BUG at c00f9040 [verbose debug info unavailable]
[27833.995865] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
[27833.995876] Modules linked in:
[27833.995892] CPU: 4 PID: 13446 Comm: RenderThread Tainted: G W 3.10.84-g9f14aec-dirty #73
[27833.995903] task: c3b73200 ti: dd192000 task.ti: dd192000
[27833.995922] PC is at page_swap_info+0x10/0x2c
[27833.995934] LR is at swap_slot_free_notify+0x18/0x6c
[27833.995946] pc : [<c00f9040>] lr : [<c00f5560>] psr: 400f0113
[27833.995946] sp : dd193d78 ip : c2deb1e4 fp : da015180
[27833.995959] r10: 00000000 r9 : 000200da r8 : c120fe08
[27833.995968] r7 : 00000000 r6 : 00000000 r5 : c249a6c0 r4 : = c249a6c0
[27833.995979] r3 : 00000000 r2 : 40080009 r1 : 200f0113 r0 : = c249a6c0
..<snip>
[27833.996273] [<c00f9040>] (page_swap_info+0x10/0x2c) from [<c00f5560>] (swap_slot_free_notify+0x18/0x6c)
[27833.996288] [<c00f5560>] (swap_slot_free_notify+0x18/0x6c) from [<c00f5c5c>] (swap_readpage+0x90/0x11c)
[27833.996302] [<c00f5c5c>] (swap_readpage+0x90/0x11c) from [<c00f62dc>] (read_swap_cache_async+0x134/0x1ac)
[27833.996317] [<c00f62dc>] (read_swap_cache_async+0x134/0x1ac) from [<c00f63c4>] (swapin_readahead+0x70/0xb0)
[27833.996334] [<c00f63c4>] (swapin_readahead+0x70/0xb0) from = [<c00e87e0>] (handle_pte_fault+0x320/0x6fc)
[27833.996348] [<c00e87e0>] (handle_pte_fault+0x320/0x6fc) from [<c00e8c7c>] (handle_mm_fault+0xc0/0xf0)
[27833.996363] [<c00e8c7c>] (handle_mm_fault+0xc0/0xf0) from = [<c001ac18>] (do_page_fault+0x11c/0x36c)
[27833.996378] [<c001ac18>] (do_page_fault+0x11c/0x36c) from = [<c000838c>] (do_DataAbort+0x34/0x118)
[27833.996392] [<c000838c>] (do_DataAbort+0x34/0x118) from [<c000d8b4>] (__dabt_usr+0x34/0x40)
Fixes: 3f2b1a04f44933f2 ("zram: revive swap_slot_free_notify")
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Tested-by: Kyeongdon Kim <kyeongdon.kim@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_io.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff -puN mm/page_io.c~mm-call-swap_slot_free_notify-with-holding-page-lock mm/page_io.c
--- a/mm/page_io.c~mm-call-swap_slot_free_notify-with-holding-page-lock
+++ a/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;
}
_
Patches currently in -mm which might be from minchan@xxxxxxxxxx are
zsmalloc-use-first_page-rather-than-page.patch
zsmalloc-clean-up-many-bug_on.patch
zsmalloc-reordering-function-parameter.patch
zsmalloc-remove-unused-pool-param-in-obj_free.patch
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