From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>,
linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
david@fromorbit.com, riteshh@linux.ibm.com,
Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 02/15] iomap: Use a IOMAP_COW/srcmap for a read-modify-write I/O
Date: Mon, 2 Sep 2019 20:18:43 -0700 [thread overview]
Message-ID: <20190903031843.GC5340@magnolia> (raw)
In-Reply-To: <20190902163104.GB6263@lst.de>
On Mon, Sep 02, 2019 at 06:31:04PM +0200, Christoph Hellwig wrote:
> On Sun, Sep 01, 2019 at 03:08:23PM -0500, Goldwyn Rodrigues wrote:
> > --- a/include/linux/iomap.h
> > +++ b/include/linux/iomap.h
> > @@ -37,6 +37,7 @@ struct vm_fault;
> > #define IOMAP_MAPPED 0x03 /* blocks allocated at @addr */
> > #define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */
> > #define IOMAP_INLINE 0x05 /* data inline in the inode */
> > +#define IOMAP_COW 0x06 /* copy data from srcmap before writing */
>
> I don't think IOMAP_COW can be a type - it is a flag given that we
> can do COW operations that allocate normal written extents (e.g. for
> direct I/O or DAX) and for delayed allocations.
If iomap_apply always zeros out @srcmap before calling ->iomap_begin, do
we even need a flag/type code? Or does it suffice to check that
srcmap.length > 0 and use it appropriately?
--D
next prev parent reply other threads:[~2019-09-03 3:37 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-01 20:08 [PATCH v3 0/15] Btrfs iomap Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 01/15] iomap: Introduce CONFIG_FS_IOMAP_DEBUG Goldwyn Rodrigues
2019-09-01 20:50 ` Darrick J. Wong
2019-09-02 16:29 ` Christoph Hellwig
2019-09-02 17:09 ` Darrick J. Wong
2019-09-02 17:18 ` Christoph Hellwig
2019-09-03 15:06 ` Darrick J. Wong
2019-09-01 20:08 ` [PATCH 02/15] iomap: Use a IOMAP_COW/srcmap for a read-modify-write I/O Goldwyn Rodrigues
2019-09-02 16:31 ` Christoph Hellwig
2019-09-03 3:18 ` Darrick J. Wong [this message]
2019-09-03 14:12 ` Goldwyn Rodrigues
2019-09-03 14:05 ` Goldwyn Rodrigues
2019-09-03 14:56 ` Darrick J. Wong
2019-09-01 20:08 ` [PATCH 03/15] iomap: Read page from srcmap for IOMAP_COW Goldwyn Rodrigues
2019-09-02 16:31 ` Christoph Hellwig
2019-09-02 17:01 ` Darrick J. Wong
2019-09-02 17:13 ` Christoph Hellwig
2019-09-01 20:08 ` [PATCH 04/15] btrfs: Eliminate PagePrivate for btrfs data pages Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 05/15] btrfs: Add a simple buffered iomap write Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 06/15] btrfs: Add CoW in iomap based writes Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 07/15] btrfs: remove buffered write code made unnecessary Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 08/15] fs: Export generic_file_buffered_read() Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 09/15] btrfs: basic direct read operation Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 10/15] btrfs: Carve out btrfs_get_extent_map_write() out of btrfs_get_blocks_write() Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 11/15] btrfs: Rename __endio_write_update_ordered() to btrfs_update_ordered_extent() Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 12/15] iomap: use a function pointer for dio submits Goldwyn Rodrigues
2019-09-02 16:41 ` Christoph Hellwig
2019-09-01 20:08 ` [PATCH 13/15] btrfs: Use iomap_dio_rw for performing direct I/O writes Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 14/15] btrfs: Remove btrfs_dio_data and __btrfs_direct_write Goldwyn Rodrigues
2019-09-01 20:08 ` [PATCH 15/15] btrfs: update inode size during bio completion Goldwyn Rodrigues
2019-09-02 16:43 ` [PATCH v3 0/15] Btrfs iomap Christoph Hellwig
2019-09-03 3:51 ` Shiyang Ruan
2019-09-03 4:29 ` Darrick J. Wong
2019-09-03 5:00 ` Shiyang Ruan
2019-09-03 6:21 ` Christoph Hellwig
2019-09-03 13:44 ` Goldwyn Rodrigues
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190903031843.GC5340@magnolia \
--to=darrick.wong@oracle.com \
--cc=david@fromorbit.com \
--cc=hch@lst.de \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=rgoldwyn@suse.com \
--cc=rgoldwyn@suse.de \
--cc=riteshh@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.