If entry does not fulfill current mark_idle() parameters, e.g. cutoff time, then we should clear its ZRAM_IDLE from previous mark_idle() invocations. Consider the following case: - mark_idle() cutoff time 8h - mark_idle() cutoff time 4h - writeback() idle - will writeback entries with cutoff time 8h, while it should only pick entries with cutoff time 4h The bug was reported by Shin Kawamura. Link: https://lkml.kernel.org/r/20241028153629.1479791-3-senozhatsky@xxxxxxxxxxxx Fixes: 755804d16965 ("zram: introduce an aged idle interface") Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> Reported-by: Shin Kawamura <kawasin@xxxxxxxxxx> Acked-by: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index a16dbffcdca3..cee49bb0126d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -410,6 +410,8 @@ static void mark_idle(struct zram *zram, ktime_t cutoff) #endif if (is_idle) zram_set_flag(zram, index, ZRAM_IDLE); + else + zram_clear_flag(zram, index, ZRAM_IDLE); zram_slot_unlock(zram, index); } }
