From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965281AbbHKOj6 (ORCPT ); Tue, 11 Aug 2015 10:39:58 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:36509 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964946AbbHKOj5 (ORCPT ); Tue, 11 Aug 2015 10:39:57 -0400 Date: Tue, 11 Aug 2015 23:38:56 +0900 From: Sergey Senozhatsky To: Sergey Senozhatsky Cc: Andrew Morton , Minchan Kim , linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: Re: [PATCH] zram: fix max pool limitation Message-ID: <20150811143856.GA3417@swordfish> References: <1439299983-8070-1-git-send-email-sergey.senozhatsky@gmail.com> <1439299983-8070-2-git-send-email-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1439299983-8070-2-git-send-email-sergey.senozhatsky@gmail.com> User-Agent: Mutt/1.5.23+102 (2ca89bed6448) (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (08/11/15 22:33), Sergey Senozhatsky wrote: > zram_meta_alloc() constructs a pool name for zs_create_pool() call > as > snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); > > However, it defines pool name buffer to be only 8 chars long > (minus trailing zero), which means that we can have only 1000 > pool names: zram0 -- zram999. > > With CONFIG_ZSMALLOC_STAT enabled an attempt to create a device > zram1000 can fail if device zram100 already exists, because > snprintf() will truncate new pool name to zram100 and pass it > to debugfs_create_dir(), causing: > > debugfs dir creation failed > zram: Error creating memory pool > > ... and so on (zram101 - zram1010, etc). > > Fix it by increasing pool_name buffer size to 11: oh... don't know how this happened. to 15. -ss > -- zram prefix (length 4) > -- int device_id can use up to 10 chars > -- terminating zero byte > > Signed-off-by: Sergey Senozhatsky > --- > drivers/block/zram/zram_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index b088ca9..1dec01d 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -502,7 +502,7 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize) > static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) > { > size_t num_pages; > - char pool_name[8]; > + char pool_name[15]; > struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); > > if (!meta) > -- > 2.5.0 >