On Tue, Oct 19, 2021 at 08:28:21AM -0700, Luis Chamberlain wrote: > On Tue, Oct 19, 2021 at 10:34:41AM +0800, Ming Lei wrote: > > Please try the following patch against upstream(linus or next) tree(basically > > fold revised 2 and 3 of V1, and cover two issues: not fail zram_remove in > > module_exit(), race between zram_remove() and disksize_store()), and see if > > everything is fine for you: > > Page fault ... > > [ 18.284256] zram: Removed device: zram0 > [ 18.312974] BUG: unable to handle page fault for address: > ffffad86de903008 > [ 18.313707] #PF: supervisor read access in kernel mode > [ 18.314248] #PF: error_code(0x0000) - not-present page > [ 18.314797] PGD 100000067 P4D 100000067 PUD 10031e067 PMD 136a28067 That is another race between zram_reset_device() and disksize_store(), which is supposed to be covered by ->init_lock, and follows the delta fix against the last patch I posted, and the whole patch can be found in the github link: https://github.com/ming1/linux/commit/fa6045b1371eb301f392ac84adaf3ad53bb16894 diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index d0cae7a42f4d..a14ba3d350ea 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1704,12 +1704,12 @@ static void zram_reset_device(struct zram *zram) set_capacity_and_notify(zram->disk, 0); part_stat_set_all(zram->disk->part0, 0); - up_write(&zram->init_lock); /* I/O operation under all of CPU are done so let's free */ zram_meta_free(zram, disksize); memset(&zram->stats, 0, sizeof(zram->stats)); zcomp_destroy(comp); reset_bdev(zram); + up_write(&zram->init_lock); } static ssize_t disksize_store(struct device *dev, -- Ming
