From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751838AbeCCIQj (ORCPT ); Sat, 3 Mar 2018 03:16:39 -0500 Received: from mx2.suse.de ([195.135.220.15]:48850 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751566AbeCCIQi (ORCPT ); Sat, 3 Mar 2018 03:16:38 -0500 Subject: Re: [PATCH] direct-io: Minor cleanups in do_blockdev_direct_IO To: Andrew Morton Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk References: <1519638870-17756-1-git-send-email-nborisov@suse.com> <20180302162400.f36d0d068bd0a08442536a2c@linux-foundation.org> From: Nikolay Borisov Message-ID: Date: Sat, 3 Mar 2018 10:16:35 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180302162400.f36d0d068bd0a08442536a2c@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3.03.2018 02:24, Andrew Morton wrote: > On Mon, 26 Feb 2018 11:54:30 +0200 Nikolay Borisov wrote: > >> We already get the block counts and the calculate the end block at the >> beginning of the function. Let's use the local variables for consistency and >> readability. No functional changes >> > > Fair enough. > >> --- a/fs/direct-io.c >> +++ b/fs/direct-io.c >> @@ -1200,7 +1200,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, >> } >> >> /* watch out for a 0 len io from a tricksy fs */ >> - if (iov_iter_rw(iter) == READ && !iov_iter_count(iter)) >> + if (iov_iter_rw(iter) == READ && !count) >> return 0; >> >> dio = kmem_cache_alloc(dio_cache, GFP_KERNEL); >> @@ -1316,8 +1316,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, >> >> dio->should_dirty = (iter->type == ITER_IOVEC); >> sdio.iter = iter; >> - sdio.final_block_in_request = >> - (offset + iov_iter_count(iter)) >> blkbits; >> + sdio.final_block_in_request = end >> blkbits; >> >> /* >> * In case of non-aligned buffers, we may need 2 more > > It's always scary to see a local being used in this fashion so far away > from where it was initialized. However, we can get our warm fuzzy > feelings by doing this: > Good point ! > --- a/fs/direct-io.c~direct-io-minor-cleanups-in-do_blockdev_direct_io-fix > +++ a/fs/direct-io.c > @@ -1178,9 +1178,9 @@ do_blockdev_direct_IO(struct kiocb *iocb > unsigned blkbits = i_blkbits; > unsigned blocksize_mask = (1 << blkbits) - 1; > ssize_t retval = -EINVAL; > - size_t count = iov_iter_count(iter); > + const size_t count = iov_iter_count(iter); > loff_t offset = iocb->ki_pos; > - loff_t end = offset + count; > + const loff_t end = offset + count; > struct dio *dio; > struct dio_submit sdio = { 0, }; > struct buffer_head map_bh = { 0, }; > _ I assume you don't want me to resend but will just fold the changes yourself? > >