linux-ext4 - Re: [PATCH 23/30] ext2: Use kmemdup rather than duplicating its implementation

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Message-ID: <20190703142457.GA26423@quack2.suse.cz>
Date:   Wed, 3 Jul 2019 16:24:57 +0200
From:   Jan Kara <jack@...e.cz>
To:     Fuqian Huang <huangfq.daxian@...il.com>
Cc:     Jan Kara <jack@...e.com>, linux-ext4@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 23/30] ext2: Use kmemdup rather than duplicating its
 implementation

On Wed 03-07-19 21:17:27, Fuqian Huang wrote:
> kmemdup is introduced to duplicate a region of memory in a neat way.
> Rather than kmalloc/kzalloc + memset, which the programmer needs to
> write the size twice (sometimes lead to mistakes), kmemdup improves
> readability, leads to smaller code and also reduce the chances of mistakes.
> Suggestion to use kmemdup rather than using kmalloc/kzalloc + memset.
> 
> Signed-off-by: Fuqian Huang <huangfq.daxian@...il.com>

Thanks. Added to my tree.

								Honza

> ---
>  fs/ext2/xattr.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
> index 1e33e0ac8cf1..a9c641cd5484 100644
> --- a/fs/ext2/xattr.c
> +++ b/fs/ext2/xattr.c
> @@ -506,11 +506,10 @@ bad_block:		ext2_error(sb, "ext2_xattr_set",
>  
>  			unlock_buffer(bh);
>  			ea_bdebug(bh, "cloning");
> -			header = kmalloc(bh->b_size, GFP_KERNEL);
> +			header = kmemdup(HDR(bh), bh->b_size, GFP_KERNEL);
>  			error = -ENOMEM;
>  			if (header == NULL)
>  				goto cleanup;
> -			memcpy(header, HDR(bh), bh->b_size);
>  			header->h_refcount = cpu_to_le32(1);
>  
>  			offset = (char *)here - bh->b_data;
> -- 
> 2.11.0
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR