linux-ext4 - Re: [PATCH] ext2: fix improper assignment for e_value

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Date:   Fri, 5 Jun 2020 17:20:05 +0200
From:   Jan Kara <jack@...e.cz>
To:     Chengguang Xu <cgxu519@...ernel.net>
Cc:     jack@...e.com, linux-ext4@...r.kernel.org
Subject: Re: [PATCH] ext2: fix improper assignment for e_value_offs

On Wed 03-06-20 16:44:29, Chengguang Xu wrote:
> In the process of changing value for existing EA,
> there is an improper assignment of e_value_offs(setting to 0),
> because it will be reset to incorrect value in the following
> loop(shifting EA values before target). Delayed assignment
> can avoid this issue.
> 
> Signed-off-by: Chengguang Xu <cgxu519@...ernel.net>

Thanks. I've added the patch to my tree.

								Honza

> ---
>  fs/ext2/xattr.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
> index 943cc469f42f..c802ea682e7f 100644
> --- a/fs/ext2/xattr.c
> +++ b/fs/ext2/xattr.c
> @@ -588,7 +588,6 @@ ext2_xattr_set(struct inode *inode, int name_index, const char *name,
>  			/* Remove the old value. */
>  			memmove(first_val + size, first_val, val - first_val);
>  			memset(first_val, 0, size);
> -			here->e_value_offs = 0;
>  			min_offs += size;
>  
>  			/* Adjust all value offsets. */
> @@ -600,6 +599,8 @@ ext2_xattr_set(struct inode *inode, int name_index, const char *name,
>  						cpu_to_le16(o + size);
>  				last = EXT2_XATTR_NEXT(last);
>  			}
> +
> +			here->e_value_offs = 0;
>  		}
>  		if (value == NULL) {
>  			/* Remove the old name. */
> -- 
> 2.20.1
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR