From: Jan Kara <jack@suse.cz>
To: Matthew Bobrowski <mbobrowski@mbobrowski.org>
Cc: Jan Kara <jack@suse.cz>,
tytso@mit.edu, adilger.kernel@dilger.ca,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
hch@infradead.org, david@fromorbit.com, darrick.wong@oracle.com
Subject: Re: [PATCH v5 12/12] ext4: introduce direct I/O write using iomap infrastructure
Date: Tue, 22 Oct 2019 09:55:48 +0200 [thread overview]
Message-ID: <20191022075548.GB2436@quack2.suse.cz> (raw)
In-Reply-To: <20191022030235.GG5092@athena.bobrowski.net>
On Tue 22-10-19 14:02:35, Matthew Bobrowski wrote:
> On Mon, Oct 21, 2019 at 06:18:48PM +0200, Jan Kara wrote:
> > > + if (extend) {
> > > + ret = ext4_handle_inode_extension(inode, ret, offset, count);
> > > +
> > > + /*
> > > + * We may have failed to remove the inode from the orphan list
> > > + * in the case that the i_disksize got update due to delalloc
> > > + * writeback while the direct I/O was running. We need to make
> > > + * sure we remove it from the orphan list as if we've
> > > + * prematurely popped it onto the list.
> > > + */
> > > + if (!list_empty(&EXT4_I(inode)->i_orphan)) {
> > > + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
> > > + if (IS_ERR(handle)) {
> > > + ret = PTR_ERR(handle);
> > > + if (inode->i_nlink)
> > > + ext4_orphan_del(NULL, inode);
> > > + goto out;
> > > + }
> > > +
> > > + if (inode->i_nlink)
> >
> > This check can be joined with the list_empty() check above to save us from
> > unnecessarily starting a transaction.
>
> Yes, easy done.
>
> > Also I was wondering whether it would not make more sense have this
> > orphan handling bit also in
> > ext4_handle_inode_extension(). ext4_dax_write_iter() doesn't
> > strictly need it (as for DAX i_disksize cannot currently change
> > while ext4_dax_write_iter() is running) but it would look more
> > robust to me for the future users and it certainly doesn't hurt
> > ext4_dax_write_iter() case.
>
> I was thinking the same, but to be honest I wasn't entirely sure how
> it would pan out for the DAX code path. However, seeing as though you
> don't forsee there being any problems, then I can't really think of a
> reason not to roll this up into ext4_handle_inode_extension().
>
> So, in ext4_handle_inode_extension() for the initial check against
> i_disksize, rather than returning 'written' and then having
> ext4_dio_write_iter() perform the cleanup, we could simply jump to a
> chunk of code in ext4_handle_inode_extension() and deal with it there,
> or quite literally just cleanup if that branch is taken there and then
> seeing as though it's not really needed in any other case? What do you
> think?
Yeah, the last option makes the most sense to me.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2019-10-22 8:50 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-21 9:17 [PATCH v5 00/12] ext4: port direct I/O to iomap infrastructure Matthew Bobrowski
2019-10-21 9:17 ` [PATCH v5 01/12] ext4: move set iomap routines into separate helper ext4_set_iomap() Matthew Bobrowski
2019-10-21 13:23 ` Jan Kara
2019-10-23 6:31 ` Ritesh Harjani
2019-10-23 10:14 ` Matthew Bobrowski
2019-10-21 9:17 ` [PATCH v5 02/12] ext4: iomap that extends beyond EOF should be marked dirty Matthew Bobrowski
2019-10-21 13:28 ` Jan Kara
2019-10-22 1:49 ` Matthew Bobrowski
2019-10-23 6:35 ` Ritesh Harjani
2019-10-23 10:20 ` Matthew Bobrowski
2019-10-21 9:18 ` [PATCH v5 03/12] ext4: split IOMAP_WRITE branch in ext4_iomap_begin() into helper Matthew Bobrowski
2019-10-21 13:31 ` Jan Kara
2019-10-23 6:37 ` Ritesh Harjani
2019-10-21 9:18 ` [PATCH v5 04/12] ext4: introduce new callback for IOMAP_REPORT Matthew Bobrowski
2019-10-21 13:37 ` Jan Kara
2019-10-22 1:55 ` Matthew Bobrowski
2019-10-23 6:39 ` Ritesh Harjani
2019-10-23 10:35 ` Matthew Bobrowski
2019-10-21 9:18 ` [PATCH v5 05/12] iomap: Allow forcing of waiting for running DIO in iomap_dio_rw() mbobrowski
2019-10-24 1:41 ` Christoph Hellwig
2019-10-24 11:17 ` Matthew Bobrowski
2019-10-21 9:18 ` [PATCH v5 06/12] xfs: Use iomap_dio_rw_wait() mbobrowski
2019-10-21 13:38 ` Jan Kara
2019-10-21 9:18 ` [PATCH v5 07/12] ext4: introduce direct I/O read using iomap infrastructure Matthew Bobrowski
2019-10-21 13:41 ` Jan Kara
2019-10-22 1:58 ` Matthew Bobrowski
2019-10-23 6:40 ` Ritesh Harjani
2019-10-21 9:18 ` [PATCH v5 08/12] ext4: update direct I/O read to do trylock in IOCB_NOWAIT cases Matthew Bobrowski
2019-10-21 13:48 ` Jan Kara
2019-10-22 2:04 ` Matthew Bobrowski
2019-10-22 7:50 ` Jan Kara
2019-10-23 6:51 ` Ritesh Harjani
2019-10-21 9:18 ` [PATCH v5 09/12] ext4: move inode extension/truncate code out from ->iomap_end() callback Matthew Bobrowski
2019-10-21 13:53 ` Jan Kara
2019-10-22 2:07 ` Matthew Bobrowski
2019-10-21 9:20 ` [PATCH v5 12/12] ext4: introduce direct I/O write using iomap infrastructure Matthew Bobrowski
2019-10-21 16:18 ` Jan Kara
2019-10-22 3:02 ` Matthew Bobrowski
2019-10-22 7:55 ` Jan Kara [this message]
2019-10-21 9:20 ` [PATCH v5 11/12] ext4: reorder map->m_flags checks in ext4_set_iomap() Matthew Bobrowski
2019-10-21 9:20 ` [PATCH v5 10/12] ext4: move inode extension check out from ext4_iomap_alloc() Matthew Bobrowski
2019-10-21 13:31 ` [PATCH v5 00/12] ext4: port direct I/O to iomap infrastructure Theodore Y. Ts'o
2019-10-21 19:43 ` Jan Kara
2019-10-21 22:38 ` Dave Chinner
2019-10-22 8:01 ` Jan Kara
2019-10-23 2:35 ` Matthew Bobrowski
2019-10-23 10:01 ` Jan Kara
2019-10-23 10:11 ` Matthew Bobrowski
2019-10-24 1:58 ` Christoph Hellwig
2019-10-24 11:09 ` Matthew Bobrowski
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