Re: [PATCH 04/13] btrfs: Add a simple buffered iomap write

From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
	hch@lst.de, darrick.wong@oracle.com, ruansy.fnst@cn.fujitsu.com,
	Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 04/13] btrfs: Add a simple buffered iomap write
Date: Thu, 22 Aug 2019 10:05:35 -0500	[thread overview]
Message-ID: <20190822150535.quzdzrvjqhzzo2sv@fiona> (raw)
In-Reply-To: <20190805001107.GF7689@dread.disaster.area>

On 10:11 05/08, Dave Chinner wrote:
> On Fri, Aug 02, 2019 at 05:00:39PM -0500, Goldwyn Rodrigues wrote:
> > From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> > 
> > Introduce a new btrfs_iomap structure which contains information
> > about the filesystem between the iomap_begin() and iomap_end() calls.
> > This contains information about reservations and extent locking.
> > 
> > This one is a long patch. Most of the code is "inspired" by
> > fs/btrfs/file.c. To keep the size small, all removals are in
> > following patches.
> 
> I can't comment on the btrfs code but this:
> 
> > +size_t btrfs_buffered_iomap_write(struct kiocb *iocb, struct iov_iter *from)
> > +{
> > +	ssize_t written;
> > +	struct inode *inode = file_inode(iocb->ki_filp);
> > +	written = iomap_file_buffered_write(iocb, from, &btrfs_buffered_iomap_ops);
> > +	if (written > 0)
> > +		iocb->ki_pos += written;
> > +	if (iocb->ki_pos > i_size_read(inode))
> > +		i_size_write(inode, iocb->ki_pos);
> > +	return written;
> 
> Looks like it fails to handle O_[D]SYNC writes.
> 

It does in btrfs_file_write_iter(), which calls btrfs_buffered_iomap_write().
btrfs_file_write_iter() calls generic_write_sync().

-- 
Goldwyn