From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id 061796B0032 for ; Fri, 23 Jan 2015 00:58:27 -0500 (EST) Received: by mail-pa0-f48.google.com with SMTP id ey11so6493264pad.7 for ; Thu, 22 Jan 2015 21:58:26 -0800 (PST) Received: from lgeamrelo01.lge.com (lgeamrelo01.lge.com. [156.147.1.125]) by mx.google.com with ESMTP id qn8si681422pab.101.2015.01.22.21.58.22 for ; Thu, 22 Jan 2015 21:58:26 -0800 (PST) From: Minchan Kim Subject: [PATCH 1/2] zram: free meta out of init_lock Date: Fri, 23 Jan 2015 14:58:26 +0900 Message-Id: <1421992707-32658-1-git-send-email-minchan@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Nitin Gupta , Jerome Marchand , Sergey Senozhatsky , Minchan Kim We don't need to call zram_meta_free, zcomp_destroy and zs_free under init_lock. What we need to prevent race with init_lock in reset is setting NULL into zram->meta (ie, init_done). This patch does it. Signed-off-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 9250b3f54a8f..0299d82275e7 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -708,6 +708,7 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) { size_t index; struct zram_meta *meta; + struct zcomp *comp; down_write(&zram->init_lock); @@ -719,20 +720,10 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) } meta = zram->meta; - /* Free all pages that are still in this zram device */ - for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { - unsigned long handle = meta->table[index].handle; - if (!handle) - continue; - - zs_free(meta->mem_pool, handle); - } - - zcomp_destroy(zram->comp); + comp = zram->comp; + zram->meta = NULL; zram->max_comp_streams = 1; - zram_meta_free(zram->meta); - zram->meta = NULL; /* Reset stats */ memset(&zram->stats, 0, sizeof(zram->stats)); @@ -742,6 +733,19 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) up_write(&zram->init_lock); + /* Free all pages that are still in this zram device */ + for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { + unsigned long handle = meta->table[index].handle; + + if (!handle) + continue; + + zs_free(meta->mem_pool, handle); + } + + zcomp_destroy(comp); + zram_meta_free(meta); + /* * Revalidate disk out of the init_lock to avoid lockdep splat. * It's okay because disk's capacity is protected by init_lock -- 1.9.1 -- 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