From: "Aneesh Kumar K. V" Subject: Re: [PATCH] ext4: memory leakage in ext4_mb_free_blocks() Date: Wed, 24 Mar 2010 22:31:54 +0530 Message-ID: <87d3ytd56l.fsf@linux.vnet.ibm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Theodore Ts'o" , Andreas Dilger , Dave Kleikamp To: jing zhang , linux-ext4 Return-path: Received: from e23smtp08.au.ibm.com ([202.81.31.141]:37701 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932074Ab0CXRCC (ORCPT ); Wed, 24 Mar 2010 13:02:02 -0400 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [202.81.31.246]) by e23smtp08.au.ibm.com (8.14.3/8.13.1) with ESMTP id o2OH20cv014841 for ; Thu, 25 Mar 2010 04:02:00 +1100 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o2OGu0Yu864508 for ; Thu, 25 Mar 2010 03:56:00 +1100 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o2OH1xf3023949 for ; Thu, 25 Mar 2010 04:02:00 +1100 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, 24 Mar 2010 21:55:55 +0800, jing zhang wrote: > From: Jing Zhang > > Date: Wed Mar 24 21:54:22 2010 > > There is memory leakage in ext4_mb_free_blocks(), if error, double > free of blocks, occurs in ext4_mb_free_metadata(). > > Cc: Theodore Ts'o > Cc: Andreas Dilger > Cc: Dave Kleikamp > Signed-off-by: Jing Zhang > > --- > > --- linux-2.6.32/fs/ext4/mballoc.c 2009-12-03 11:51:22.000000000 +0800 > +++ ext4_mm_leak/mballoc8.c 2010-03-24 21:46:50.000000000 +0800 > @@ -4419,7 +4419,8 @@ ext4_mb_free_metadata(handle_t *handle, > spin_lock(&sbi->s_md_lock); > list_add(&new_entry->list, &handle->h_transaction->t_private_list); > spin_unlock(&sbi->s_md_lock); > - return 0; > + /* info the caller new_entry is used */ > + return 1; > } > return 0 on success and -1 on failure > /* > @@ -4547,7 +4548,8 @@ do_more: > > ext4_lock_group(sb, block_group); > mb_clear_bits(bitmap_bh->b_data, bit, count); > - ext4_mb_free_metadata(handle, &e4b, new_entry); > + if (0 == ext4_mb_free_metadata(handle, &e4b, new_entry)) > + kmem_cache_free(ext4_free_ext_cachep, > new_entry); I guess it would be better to be if (ext4_mb_free_metadat() == -1) kmem_cache_free(..) > } else { > /* need to update group_info->bb_free and bitmap > * with group lock held. generate_buddy look at -aneesh