Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759177AbbFBPMf (ORCPT ); Tue, 2 Jun 2015 11:12:35 -0400 Received: from mail-ob0-f178.google.com ([209.85.214.178]:36584 "EHLO mail-ob0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759290AbbFBPMS (ORCPT ); Tue, 2 Jun 2015 11:12:18 -0400 From: Dan Streetman To: Seth Jennings , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, 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> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1433257917-13090-1-git-send-email-ddstreet@ieee.org> References: <1433257917-13090-1-git-send-email-ddstreet@ieee.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2028 Lines: 71 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/