[Devel] Re: [PATCH] incorrect error handling inside generic_file_direct_write

['Christoph Hellwig']

> +ssize_t
> +__generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
> +				unsigned long nr_segs, loff_t pos)

I'd still call this generic_file_aio_write_nolock.

> +	loff_t		*ppos = &iocb->ki_pos;

I'd rather use iocb->ki_pos directly in the few places ppos is referenced
currently.

>  	if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
> -		ssize_t err;
> -
>  		err = sync_page_range_nolock(inode, mapping, pos, ret);
>  		if (err < 0)
>  			ret = err;
>  	}

So we're doing the sync_page_range once in __generic_file_aio_write
with i_mutex held.


>  	mutex_lock(&inode->i_mutex);
> -	ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
> -			&iocb->ki_pos);
> +	ret = __generic_file_aio_write(iocb, iov, nr_segs, pos);
>  	mutex_unlock(&inode->i_mutex);
>  
>  	if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {

And then another time after it's unlocked, this seems wrong.