linux-kernel - Re: [PATCH v2 04/17] ext2: don't test/clear AS

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Date:   Wed, 12 Apr 2017 14:29:21 +0200
From:   Jan Kara <jack@...e.cz>
To:     Jeff Layton <jlayton@...hat.com>
Cc:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        akpm@...ux-foundation.org, tytso@....edu, jack@...e.cz,
        willy@...radead.org, neilb@...e.com, viro@...iv.linux.org.uk
Subject: Re: [PATCH v2 04/17] ext2: don't test/clear AS_EIO flag

On Wed 12-04-17 08:06:01, Jeff Layton wrote:
> ext2 does a test+clear of AS_EIO flag. With the new error reporting
> infrastructure, we don't need to clear anything. Sample the file's
> current error code, and after writeback just report whether any
> errors have been seen since then.
> 
> Signed-off-by: Jeff Layton <jlayton@...hat.com>
> ---
>  fs/ext2/file.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext2/file.c b/fs/ext2/file.c
> index b21891a6bfca..0ca77d337c94 100644
> --- a/fs/ext2/file.c
> +++ b/fs/ext2/file.c
> @@ -177,7 +177,12 @@ int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
>  	struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
>  
>  	ret = generic_file_fsync(file, start, end, datasync);
> -	if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) {
> +	if (ret == -EIO)
> +		ret = -EIO;
> +	else
> +		ret = filemap_check_errors(mapping);
> +

IMO making __generic_file_fsync() perform the filemap_check_errors() after
sync_mapping_buffers() is better and deals with all filesystem using
generic_file_fsync(). Then we can just remove the AS_EIO check here.

								Honza

> +	if (ret) {
>  		/* We don't really know where the IO error happened... */
>  		ext2_error(sb, __func__,
>  			   "detected IO error when writing metadata buffers");
> -- 
> 2.9.3
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR