From: jing zhang Subject: Re: [PATCH] ext4: memory leakage in ext4_mb_init() Date: Sun, 28 Mar 2010 16:13:51 +0800 Message-ID: References: <20100322012758.GE11560@thunk.org> <87sk7nv4sp.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: tytso@mit.edu, linux-ext4 , Andreas Dilger , Dave Kleikamp To: "Aneesh Kumar K. V" Return-path: Received: from mail-yx0-f191.google.com ([209.85.210.191]:57666 "EHLO mail-yx0-f191.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753789Ab0C1INy (ORCPT ); Sun, 28 Mar 2010 04:13:54 -0400 Received: by yxe29 with SMTP id 29so1497947yxe.4 for ; Sun, 28 Mar 2010 01:13:52 -0700 (PDT) In-Reply-To: <87sk7nv4sp.fsf@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2010/3/26, Aneesh Kumar K. V : > On Tue, 23 Mar 2010 20:47:39 +0800, jing zhang wrote: >> 2010/3/22, tytso@mit.edu : >> > On Sun, Mar 21, 2010 at 10:01:06PM +0800, jing zhang wrote: >> >> From: Jing Zhang >> >> >> >> Date: Sun Mar 21 21:59:35 2010 >> >> >> >> 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/mballoc3.c 2010-03-21 21:37:18.000000000 +0800 >> >> @@ -2360,6 +2360,24 @@ err_freesgi: >> >> return -ENOMEM; >> >> } >> >> >> >> +static void ext4_mb_destroy_backend(struct super_block *sb) >> >> +{ >> >> + ext4_group_t ngroups = ext4_get_groups_count(sb); >> >> + ext4_group_t i; >> >> + struct ext4_sb_info *sbi = EXT4_SB(sb); >> >> + int j; >> >> + int num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) -1) >> >> + >> EXT4_DESC_PER_BLOCK_BITS(sb); >> >> + for (i = 0; i < ngroups; i++) >> >> + kfree(ext4_get_group_info(sb, i)); >> >> + >> >> + for (j = 0; j < num_meta_group_infos; j++) >> >> + kfree(sbi->s_group_info[j]); >> >> + >> >> + kfree(sbi->s_group_info); >> >> + iput(sbi->s_buddy_cache); >> >> +} >> >> + >> > >> > It would be better if this could be done by making ext4_mb_release() >> > more flexible, and then calling ext4_mb_release() if there is an error >> > setting up the data structures in ext4_mb_init(). >> > >> > - Ted >> > >> >> Yeah, Ted, going through ext4_mb_release() is clearer. >> >> --- >> >> diff --git a/linux-2.6.32/fs/ext4/mballoc.c b/ext4_mm_leak/mballoc3.c >> index bba1282..99ca2de 100644 >> --- a/linux-2.6.32/fs/ext4/mballoc.c >> +++ b/ext4_mm_leak/mballoc3.c >> @@ -2417,8 +2417,7 @@ int ext4_mb_init(struct super_block *sb, int >> needs_recovery) >> >> sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); >> if (sbi->s_locality_groups == NULL) { >> - kfree(sbi->s_mb_offsets); >> - kfree(sbi->s_mb_maxs); >> + ext4_mb_release(sb); > > We may want to make sure that we can safely call ext4_mb_release that > early. what i would suggest is to move s_locality_group allocation > before ext4_mb_init. that makes error handling easy > cool idea, Aneesh, and I got it. --- --- old-linux-2.6.32/fs/ext4/mballoc.c 2009-12-03 11:51:22.000000000 +0800 +++ ext4_mm_leak/mballoc3-2.c 2010-03-28 16:13:20.000000000 +0800 @@ -2397,11 +2397,27 @@ int ext4_mb_init(struct super_block *sb, i++; } while (i <= sb->s_blocksize_bits + 1); + sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); + if (sbi->s_locality_groups == NULL) { + kfree(sbi->s_mb_offsets); + kfree(sbi->s_mb_maxs); + return -ENOMEM; + } + for_each_possible_cpu(i) { + struct ext4_locality_group *lg; + lg = per_cpu_ptr(sbi->s_locality_groups, i); + mutex_init(&lg->lg_mutex); + for (j = 0; j < PREALLOC_TB_SIZE; j++) + INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); + spin_lock_init(&lg->lg_prealloc_lock); + } + /* init file for buddy data */ ret = ext4_mb_init_backend(sb); if (ret != 0) { kfree(sbi->s_mb_offsets); kfree(sbi->s_mb_maxs); + free_percpu(sbi->s_locality_groups); return ret; } @@ -2415,20 +2431,6 @@ int ext4_mb_init(struct super_block *sb, sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC; - sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); - if (sbi->s_locality_groups == NULL) { - kfree(sbi->s_mb_offsets); - kfree(sbi->s_mb_maxs); - return -ENOMEM; - } - for_each_possible_cpu(i) { - struct ext4_locality_group *lg; - lg = per_cpu_ptr(sbi->s_locality_groups, i); - mutex_init(&lg->lg_mutex); - for (j = 0; j < PREALLOC_TB_SIZE; j++) - INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); - spin_lock_init(&lg->lg_prealloc_lock); - } if (sbi->s_proc) proc_create_data("mb_groups", S_IRUGO, sbi->s_proc, > > >> return -ENOMEM; >> } >> for_each_possible_cpu(i) { >> @@ -2511,7 +2510,8 @@ int ext4_mb_release(struct super_block *sb) >> atomic_read(&sbi->s_mb_discarded)); >> } >> >> - free_percpu(sbi->s_locality_groups); >> + if (sbi->s_locality_groups) >> + free_percpu(sbi->s_locality_groups); >> if (sbi->s_proc) >> remove_proc_entry("mb_groups", sbi->s_proc); >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -aneesh >