From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Luis Chamberlain <mcgrof@kernel.org>,
Minchan Kim <minchan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, Ming Lei <ming.lei@redhat.com>
Subject: [PATCH V2 3/4] zram: avoid race between zram_remove and disksize_store
Date: Wed, 20 Oct 2021 09:55:47 +0800 [thread overview]
Message-ID: <20211020015548.2374568-4-ming.lei@redhat.com> (raw)
In-Reply-To: <20211020015548.2374568-1-ming.lei@redhat.com>
After resetting device in zram_remove(), disksize_store still may come and
allocate resources again before deleting gendisk, fix the race by resetting
zram after del_gendisk() returns. At that time, disksize_store can't come
any more.
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/zram/zram_drv.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 8883de7aa3d7..6078d1dae44a 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2002,6 +2002,13 @@ static int zram_remove(struct zram *zram)
/* del_gendisk drains pending reset_store */
WARN_ON_ONCE(claimed && zram->claim);
+ /*
+ * disksize store may come between zram_reset_device and del_gendisk, so
+ * run the last reset for avoiding leak anything allocated in
+ * disksize_store().
+ */
+ zram_reset_device(zram);
+
blk_cleanup_disk(zram->disk);
kfree(zram);
return 0;
--
2.31.1
next prev parent reply other threads:[~2021-10-20 1:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-20 1:55 [PATCH V2 0/4] zram: fix two races and one zram leak Ming Lei
2021-10-20 1:55 ` [PATCH V2 1/4] zram: fix race between zram_reset_device() and disksize_store() Ming Lei
2021-10-21 23:03 ` Luis Chamberlain
2021-10-20 1:55 ` [PATCH V2 2/4] zram: don't fail to remove zram during unloading module Ming Lei
2021-10-21 23:50 ` Luis Chamberlain
2021-10-22 0:38 ` Ming Lei
2021-10-20 1:55 ` Ming Lei [this message]
2021-10-22 19:02 ` [PATCH V2 3/4] zram: avoid race between zram_remove and disksize_store Luis Chamberlain
2021-10-20 1:55 ` [PATCH V2 4/4] zram: replace fsync_bdev with sync_blockdev Ming Lei
2021-10-22 19:06 ` Luis Chamberlain
2021-10-20 21:40 ` [PATCH V2 0/4] zram: fix two races and one zram leak Minchan Kim
2021-10-21 17:39 ` Luis Chamberlain
2021-10-21 17:46 ` Luis Chamberlain
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