linux-ext4 - Re: [PATCH 1/2] ext4: cleanup GFP flags inside resize path V2

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Date:	Mon, 24 Nov 2014 15:55:13 +0300
From:	Dmitry Monakhov <dmonakhov@...nvz.org>
To:	linux-ext4@...r.kernel.org
Cc:	tytso@....edu, cmm@...ibm.com
Subject: Re: [PATCH 1/2] ext4: cleanup GFP flags inside resize path V2


Ping...


Dmitry Monakhov <dmonakhov@...nvz.org> writes:

> We must use GFP_NOFS instead GFP_KERNEL inside ext4_mb_add_groupinfo because resize-path
> call  it inside journal transaction. Call trace:
> ioctl
>  ->ext4_group_add
>    ->journal_start
>    ->ext4_setup_new_descs
>      ->ext4_mb_add_groupinfo -> GFP_KERNEL
>    ->ext4_flex_group_add
>      ->ext4_update_super
>        ->ext4_calculate_overhead  -> GFP_KERNEL
>    ->journal_stop
>
> Changes from V1:
>  - Fix up gfp flags for ext4_calculate_overhead
>
> ext4_update_super
>
> Signed-off-by: Dmitry Monakhov <dmonakhov@...nvz.org>
> ---
>  fs/ext4/mballoc.c |    6 +++---
>  fs/ext4/super.c   |    2 +-
>  2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index dbfe15c..654e70d 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2385,7 +2385,7 @@ int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
>  	if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
>  		metalen = sizeof(*meta_group_info) <<
>  			EXT4_DESC_PER_BLOCK_BITS(sb);
> -		meta_group_info = kmalloc(metalen, GFP_KERNEL);
> +		meta_group_info = kmalloc(metalen, GFP_NOFS);
>  		if (meta_group_info == NULL) {
>  			ext4_msg(sb, KERN_ERR, "can't allocate mem "
>  				 "for a buddy group");
> @@ -2399,7 +2399,7 @@ int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
>  		sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
>  	i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
>  
> -	meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_KERNEL);
> +	meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
>  	if (meta_group_info[i] == NULL) {
>  		ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
>  		goto exit_group_info;
> @@ -2428,7 +2428,7 @@ int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
>  	{
>  		struct buffer_head *bh;
>  		meta_group_info[i]->bb_bitmap =
> -			kmalloc(sb->s_blocksize, GFP_KERNEL);
> +			kmalloc(sb->s_blocksize, GFP_NOFS);
>  		BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
>  		bh = ext4_read_block_bitmap(sb, group);
>  		BUG_ON(bh == NULL);
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 2c9e686..5f6cab8 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -3310,7 +3310,7 @@ int ext4_calculate_overhead(struct super_block *sb)
>  	struct ext4_super_block *es = sbi->s_es;
>  	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
>  	ext4_fsblk_t overhead = 0;
> -	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
> +	char *buf = (char *) get_zeroed_page(GFP_NOFS);
>  
>  	if (!buf)
>  		return -ENOMEM;
> -- 
> 1.7.1

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