Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965111AbcDYVWj (ORCPT ); Mon, 25 Apr 2016 17:22:39 -0400 Received: from mail-qk0-f193.google.com ([209.85.220.193]:33815 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964914AbcDYVWh (ORCPT ); Mon, 25 Apr 2016 17:22:37 -0400 From: Dan Streetman To: Yu Zhao , Andrew Morton , Seth Jennings Cc: Sergey Senozhatsky , Minchan Kim , Nitin Gupta , Linux-MM , Sergey Senozhatsky , linux-kernel , Dan Streetman , Dan Streetman Subject: [PATCH] mm/zpool: use workqueue for zpool_destroy Date: Mon, 25 Apr 2016 17:20:10 -0400 Message-Id: <1461619210-10057-1-git-send-email-ddstreet@ieee.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2251 Lines: 71 Add a work_struct to struct zpool, and change zpool_destroy_pool to defer calling the pool implementation destroy. The zsmalloc pool destroy function, which is one of the zpool implementations, may sleep during destruction of the pool. However zswap, which uses zpool, may call zpool_destroy_pool from atomic context. So we need to defer the call to the zpool implementation to destroy the pool. This is essentially the same as Yu Zhao's proposed patch to zsmalloc, but moved to zpool. Reported-by: Yu Zhao Signed-off-by: Dan Streetman Cc: Dan Streetman --- mm/zpool.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/mm/zpool.c b/mm/zpool.c index fd3ff71..ea12069 100644 --- a/mm/zpool.c +++ b/mm/zpool.c @@ -23,6 +23,7 @@ struct zpool { const struct zpool_ops *ops; struct list_head list; + struct work_struct work; }; static LIST_HEAD(drivers_head); @@ -197,6 +198,15 @@ struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp, return zpool; } +static void zpool_destroy_pool_work(struct work_struct *work) +{ + struct zpool *zpool = container_of(work, struct zpool, work); + + zpool->driver->destroy(zpool->pool); + zpool_put_driver(zpool->driver); + kfree(zpool); +} + /** * zpool_destroy_pool() - Destroy a zpool * @pool The zpool to destroy. @@ -204,7 +214,8 @@ struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp, * Implementations must guarantee this to be thread-safe, * however only when destroying different pools. The same * pool should only be destroyed once, and should not be used - * after it is destroyed. + * after it is destroyed. This defers calling the implementation + * to a workqueue, so the implementation may sleep. * * This destroys an existing zpool. The zpool should not be in use. */ @@ -215,9 +226,8 @@ void zpool_destroy_pool(struct zpool *zpool) spin_lock(&pools_lock); list_del(&zpool->list); spin_unlock(&pools_lock); - zpool->driver->destroy(zpool->pool); - zpool_put_driver(zpool->driver); - kfree(zpool); + INIT_WORK(&zpool->work, zpool_destroy_pool_work); + schedule_work(&zpool->work); } /** -- 2.7.4