linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 01/15] btrfs: create a mount option for dax
Date: Tue, 26 Mar 2019 12:10:01 -0700	[thread overview]
Message-ID: <20190326191001.GP10344@bombadil.infradead.org> (raw)
In-Reply-To: <20190326190301.32365-2-rgoldwyn@suse.de>

On Tue, Mar 26, 2019 at 02:02:47PM -0500, Goldwyn Rodrigues wrote:
> This sets S_DAX in inode->i_flags, which can be used with
> IS_DAX().
> 
> The dax option is restricted to non multi-device mounts.
> dax interacts with the device directly instead of using bio, so
> all bio-hooks which we use for multi-device cannot be performed
> here. While regular read/writes could be manipulated with
> RAID0/1, mmap() is still an issue.
> 
> Auto-setting free space tree, because dealing with free space
> inode (specifically readpages) is a nightmare.
> Auto-setting nodatasum because we don't get callback for writing
> checksums after mmap()s.

Congratulations on getting the bear to dance.  But why?

To me, the point of btrfs is all the cool stuff it does with built-in
checksumming and snapshots and RAID and so on.  DAX doesn't let you do
any of that, so why would somebody want to use btrfs to manage DAX?


  reply	other threads:[~2019-03-26 19:10 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190326190301.32365-1-rgoldwyn@suse.de>
2019-03-26 19:02 ` [PATCH 01/15] btrfs: create a mount option for dax Goldwyn Rodrigues
2019-03-26 19:10   ` Matthew Wilcox [this message]
2019-03-27 11:00     ` Goldwyn Rodrigues
2019-03-27 12:00       ` Matthew Wilcox
2019-03-27 12:26         ` Goldwyn Rodrigues
2019-03-27 23:31         ` Goldwyn Rodrigues
2019-03-27 17:38     ` Adam Borowski
2019-03-28 14:49   ` David Sterba
2019-03-28 17:28   ` David Sterba
2019-03-28 17:57     ` Darrick J. Wong
2019-04-01 20:43     ` Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 02/15] btrfs: Carve out btrfs_get_extent_map_write() out of btrfs_get_blocks_write() Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 03/15] btrfs: basic dax read Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 04/15] dax: Introduce IOMAP_F_COW for copy-on-write Goldwyn Rodrigues
2019-03-27 17:54   ` Darrick J. Wong
2019-03-27 18:58     ` Goldwyn Rodrigues
2019-03-28 14:45       ` Darrick J. Wong
2019-04-01  4:38   ` Dave Chinner
2019-04-01 21:41     ` Goldwyn Rodrigues
2019-04-01 23:06       ` Dave Chinner
2019-04-03  1:56         ` Goldwyn Rodrigues
2019-04-03  3:20           ` Dave Chinner
2019-04-07  7:26     ` Christoph Hellwig
2019-03-26 19:02 ` [PATCH 05/15] btrfs: return whether extent is nocow or not Goldwyn Rodrigues
2019-03-31 18:42   ` Nikolay Borisov
2019-03-26 19:02 ` [PATCH 06/15] btrfs: Rename __endio_write_update_ordered() to btrfs_update_ordered_extent() Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 07/15] btrfs: add dax write support Goldwyn Rodrigues
2019-03-28 14:53   ` Darrick J. Wong
2019-04-01 20:39     ` Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 08/15] dax: add dax_iomap_cow to copy a mmap page before writing Goldwyn Rodrigues
2019-03-28 15:41   ` Darrick J. Wong
2019-03-26 19:02 ` [PATCH 09/15] btrfs: add dax mmap support Goldwyn Rodrigues
2019-03-28 15:45   ` Darrick J. Wong
2019-03-26 19:02 ` [PATCH 10/15] btrfs: Add dax specific address_space_operations Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 11/15] fs: dedup file range to use a compare function Goldwyn Rodrigues
2019-03-28 17:04   ` Darrick J. Wong
2019-04-01 20:36     ` Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 12/15] btrfs: trace functions for btrfs_iomap_begin/end Goldwyn Rodrigues
2019-03-26 19:02 ` [PATCH 13/15] btrfs: handle dax page zeroing Goldwyn Rodrigues
2019-03-26 19:03 ` [PATCH 14/15] btrfs: Disable dax-based defrag and send Goldwyn Rodrigues
2019-03-26 19:03 ` [PATCH 15/15] btrfs: Writeprotect mmap pages on snapshot Goldwyn Rodrigues
2019-03-28 15:48   ` Darrick J. Wong
2019-03-26 19:09 ` [PATCH v2 00/15] btrfs dax support Goldwyn Rodrigues
2019-03-27 20:14   ` Adam Borowski
2019-03-27 23:26     ` Goldwyn Rodrigues
2019-03-28 10:24       ` [PATCH] btrfs: allow MAP_SYNC mmap Adam Borowski
2019-03-28 10:42         ` Adam Borowski
2019-04-01 20:08         ` 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=20190326191001.GP10344@bombadil.infradead.org \
    --to=willy@infradead.org \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=rgoldwyn@suse.com \
    --cc=rgoldwyn@suse.de \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).