From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
darrick.wong@oracle.com, linux-xfs@vger.kernel.org,
Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 02/15] iomap: Read page from srcmap if IOMAP_F_COW is set
Date: Thu, 5 Sep 2019 15:28:05 -0500 [thread overview]
Message-ID: <20190905202805.nhhmsyiicnyeaeuy@fiona> (raw)
In-Reply-To: <20190905163756.GA22883@lst.de>
On 18:37 05/09, Christoph Hellwig wrote:
> On Thu, Sep 05, 2019 at 10:06:37AM -0500, Goldwyn Rodrigues wrote:
> > - else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
> > + } else if (iomap->flags & IOMAP_F_COW) {
> > + if (WARN_ON_ONCE(iomap->flags & IOMAP_F_BUFFER_HEAD)) {
> > + status = -EIO;
> > + goto out_no_page;
> > + }
> > + if (WARN_ON_ONCE(srcmap->type == IOMAP_HOLE &&
> > + srcmap->addr != IOMAP_NULL_ADDR)) {
>
> Well, we want HOLES to have IOMAP_NULL_ADDR everywhere, so not sure
> why the assert is just here.
This came up as one of the review comments for checking srcmap.
This does look ugly after taking out iomap_assert(). Removing.
>
> > + status = -EIO;
> > + goto out_no_page;
> > + }
> > + status = __iomap_write_begin(inode, pos, len, page, srcmap);
> > + } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
> > status = __block_write_begin_int(page, pos, len, NULL, iomap);
> > - else
> > + } else {
> > status = __iomap_write_begin(inode, pos, len, page, iomap);
> > + }
>
> Maybe a good way to structure this is:
>
> if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
> if (WARN_ON_ONCE(iomap->flags & IOMAP_F_COW)) {
> status = -EIO;
> goto out_no_page;
> }
> status = __block_write_begin_int(page, pos, len, NULL, iomap);
> } else {
> status = __iomap_write_begin(inode, pos, len, page,
> (iomap->flags & IOMAP_F_COW) ? srcmap : iomap);
> }
Yes, this looks much better. Will incorporate.
--
Goldwyn
next prev parent reply other threads:[~2019-09-05 20:28 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 15:06 [PATCH v4 0/15] CoW support for iomap Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 01/15] iomap: Use a srcmap for a read-modify-write I/O Goldwyn Rodrigues
2019-09-05 23:23 ` Darrick J. Wong
2019-09-05 15:06 ` [PATCH 02/15] iomap: Read page from srcmap if IOMAP_F_COW is set Goldwyn Rodrigues
2019-09-05 16:37 ` Christoph Hellwig
2019-09-05 20:28 ` Goldwyn Rodrigues [this message]
2019-09-05 15:06 ` [PATCH 03/15] btrfs: Eliminate PagePrivate for btrfs data pages Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 04/15] btrfs: Add a simple buffered iomap write Goldwyn Rodrigues
2019-09-05 16:23 ` Christoph Hellwig
2019-09-05 20:42 ` Goldwyn Rodrigues
2019-09-06 5:54 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 05/15] btrfs: Add CoW in iomap based writes Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 06/15] btrfs: remove buffered write code made unnecessary Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 07/15] fs: Export generic_file_buffered_read() Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 08/15] btrfs: basic direct read operation Goldwyn Rodrigues
2019-09-05 16:25 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 09/15] btrfs: Carve out btrfs_get_extent_map_write() out of btrfs_get_blocks_write() Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 10/15] btrfs: Rename __endio_write_update_ordered() to btrfs_update_ordered_extent() Goldwyn Rodrigues
2019-09-05 15:06 ` [PATCH 11/15] iomap: use a function pointer for dio submits Goldwyn Rodrigues
2019-09-05 16:27 ` Christoph Hellwig
2019-09-05 23:24 ` Darrick J. Wong
2019-09-05 15:06 ` [PATCH 12/15] btrfs: Use iomap_dio_rw for performing direct I/O writes Goldwyn Rodrigues
2019-09-05 16:31 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 13/15] btrfs: Remove btrfs_dio_data and __btrfs_direct_write Goldwyn Rodrigues
2019-09-05 16:32 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 14/15] btrfs: update inode size during bio completion Goldwyn Rodrigues
2019-09-05 16:33 ` Christoph Hellwig
2019-09-05 15:06 ` [PATCH 15/15] xfs: Use the new iomap infrastructure for CoW Goldwyn Rodrigues
2019-09-06 16:55 ` Christoph Hellwig
2019-09-06 23:28 ` Dave Chinner
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