From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f179.google.com (mail-ob0-f179.google.com [209.85.214.179]) by kanga.kvack.org (Postfix) with ESMTP id C35346B006C for ; Tue, 2 Jun 2015 11:12:18 -0400 (EDT) Received: by obbnx5 with SMTP id nx5so129749850obb.0 for ; Tue, 02 Jun 2015 08:12:18 -0700 (PDT) Received: from mail-oi0-x229.google.com (mail-oi0-x229.google.com. [2607:f8b0:4003:c06::229]) by mx.google.com with ESMTPS id j8si1733777oia.52.2015.06.02.08.12.17 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Jun 2015 08:12:18 -0700 (PDT) Received: by oiww2 with SMTP id w2so127948062oiw.0 for ; Tue, 02 Jun 2015 08:12:17 -0700 (PDT) From: Dan Streetman Subject: [PATCH 1/5] zpool: add zpool_has_pool() Date: Tue, 2 Jun 2015 11:11:53 -0400 Message-Id: <1433257917-13090-2-git-send-email-ddstreet@ieee.org> In-Reply-To: <1433257917-13090-1-git-send-email-ddstreet@ieee.org> References: <1433257917-13090-1-git-send-email-ddstreet@ieee.org> Sender: owner-linux-mm@kvack.org List-ID: To: Seth Jennings , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dan Streetman Add zpool_has_pool() function, indicating if the specified type of zpool is available (i.e. zsmalloc or zbud). This allows checking if a pool is available, without actually trying to allocate it, similar to crypto_has_alg(). This is used by a following patch to zswap that enables the dynamic runtime creation of zswap zpools. Signed-off-by: Dan Streetman --- include/linux/zpool.h | 2 ++ mm/zpool.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/linux/zpool.h b/include/linux/zpool.h index 56529b3..31b79e2 100644 --- a/include/linux/zpool.h +++ b/include/linux/zpool.h @@ -36,6 +36,8 @@ enum zpool_mapmode { ZPOOL_MM_DEFAULT = ZPOOL_MM_RW }; +bool zpool_has_pool(char *type); + struct zpool *zpool_create_pool(char *type, char *name, gfp_t gfp, struct zpool_ops *ops); diff --git a/mm/zpool.c b/mm/zpool.c index 884659d..bff40ce 100644 --- a/mm/zpool.c +++ b/mm/zpool.c @@ -127,6 +127,31 @@ static void zpool_put_driver(struct zpool_driver *driver) } /** + * zpool_has_pool() - Check if the pool driver is available + * @type The type of the zpool to check (e.g. zbud, zsmalloc) + * + * This checks if the @type pool driver is available. + * + * Returns: true if @type pool is available, false if not + */ +bool zpool_has_pool(char *type) +{ + struct zpool_driver *driver = zpool_get_driver(type); + + if (!driver) { + request_module("zpool-%s", type); + driver = zpool_get_driver(type); + } + + if (!driver) + return false; + + zpool_put_driver(driver); + return true; +} +EXPORT_SYMBOL(zpool_has_pool); + +/** * zpool_create_pool() - Create a new zpool * @type The type of the zpool to create (e.g. zbud, zsmalloc) * @name The name of the zpool (e.g. zram0, zswap) -- 2.1.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org