Date: Wed, 26 Apr 2017 09:46:20 +0200
From: Jan Kara <jack@suse.cz>
To: Heloise <os@iscas.ac.cn>
Cc: akpm@linux-foundation.org, fabf@skynet.be, viro@zeniv.linux.org.uk,
        jack@suse.cz, mszeredi@redhat.com, mikulas@twibright.com,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fs:affs:fix sb_bread() return value
Message-ID: <20170426074620.GC21218@quack2.suse.cz>
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On Tue 25-04-17 23:59:14, Heloise wrote:
> When the function sb_bread() fails, the return value should
> be -EIO, fix it.
> 
> Signed-off-by: Heloise <os@iscas.ac.cn>

Well, in the mount(2) manpage we have:

EINVAL source had an invalid superblock. Or, a remount (MS_REMOUNT) was
attempted, but source was not already mounted on target. Or, a move
(MS_MOVE) was attempted, but source was not a mount point, or was '/'.

And EIO is not documented as possible error for mount(2). Looking at e.g.
ext4 it also returns EINVAL when superblock cannot be read so I guess it is
an expected return value in this case.

								Honza

> ---
>  fs/affs/super.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/affs/super.c b/fs/affs/super.c
> index c2c27a8..df1f4fe 100644
> --- a/fs/affs/super.c
> +++ b/fs/affs/super.c
> @@ -419,7 +419,7 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent)
>  	boot_bh = sb_bread(sb, 0);
>  	if (!boot_bh) {
>  		pr_err("Cannot read boot block\n");
> -		return -EINVAL;
> +		return -EIO;
>  	}
>  	memcpy(sig, boot_bh->b_data, 4);
>  	brelse(boot_bh);
> -- 
> 2.1.0
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR