From: Anand Jain <anand.jain@oracle.com>
To: Naohiro Aota <naohiro.aota@wdc.com>,
linux-btrfs@vger.kernel.org, dsterba@suse.com
Cc: hare@suse.com, linux-fsdevel@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>,
Christoph Hellwig <hch@infradead.org>,
"Darrick J. Wong" <darrick.wong@oracle.com>
Subject: Re: [PATCH v10 11/41] btrfs: implement log-structured superblock for ZONED mode
Date: Tue, 24 Nov 2020 14:46:32 +0800 [thread overview]
Message-ID: <69855ff1-4737-3d4c-f191-f31f8307fe88@oracle.com> (raw)
In-Reply-To: <5aa30b45e2e29018e19e47181586f3f436759b69.1605007036.git.naohiro.aota@wdc.com>
On 10/11/20 7:26 pm, Naohiro Aota wrote:
> Superblock (and its copies) is the only data structure in btrfs which has a
> fixed location on a device. Since we cannot overwrite in a sequential write
> required zone, we cannot place superblock in the zone. One easy solution is
> limiting superblock and copies to be placed only in conventional zones.
> However, this method has two downsides: one is reduced number of superblock
> copies. The location of the second copy of superblock is 256GB, which is in
> a sequential write required zone on typical devices in the market today.
> So, the number of superblock and copies is limited to be two. Second
> downside is that we cannot support devices which have no conventional zones
> at all.
>
> To solve these two problems, we employ superblock log writing. It uses two
> zones as a circular buffer to write updated superblocks. Once the first
> zone is filled up, start writing into the second buffer. Then, when the
> both zones are filled up and before start writing to the first zone again,
> it reset the first zone.
>
> We can determine the position of the latest superblock by reading write
> pointer information from a device. One corner case is when the both zones
> are full. For this situation, we read out the last superblock of each
> zone, and compare them to determine which zone is older.
>
> The following zones are reserved as the circular buffer on ZONED btrfs.
>
> - The primary superblock: zones 0 and 1
> - The first copy: zones 16 and 17
> - The second copy: zones 1024 or zone at 256GB which is minimum, and next
> to it
Superblock log approach needs a non-deterministic and inconsistent
number of blocks to be read to find copy #0. And, to use 4K bytes
we are reserving a lot more space. But I don't know any better way.
I am just checking with you...
At the time of mkfs, is it possible to format the block device to
add conventional zones as needed to support our sb LBAs?
OR
For superblock zones why not reset the write pointer before the
transaction commit?
Thanks.
> If these reserved zones are conventional, superblock is written fixed at
> the start of the zone without logging.
>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
next prev parent reply other threads:[~2020-11-24 6:49 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 11:26 [PATCH v10 00/41] btrfs: zoned block device support Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 01/41] block: add bio_add_zone_append_page Naohiro Aota
2020-11-10 17:20 ` Christoph Hellwig
2020-11-11 7:20 ` Johannes Thumshirn
2020-11-10 11:26 ` [PATCH v10 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
2020-11-10 17:25 ` Christoph Hellwig
2020-11-10 18:55 ` Darrick J. Wong
2020-11-10 19:01 ` Darrick J. Wong
2020-11-24 11:29 ` Christoph Hellwig
2020-11-30 18:11 ` Darrick J. Wong
2020-12-01 10:16 ` Johannes Thumshirn
2020-12-09 9:31 ` Christoph Hellwig
2020-12-09 10:08 ` Johannes Thumshirn
2020-12-09 10:10 ` hch
2020-12-09 10:16 ` Johannes Thumshirn
2020-12-09 13:38 ` Johannes Thumshirn
2020-12-11 7:26 ` Johannes Thumshirn
2020-12-11 21:24 ` Chaitanya Kulkarni
2020-12-12 10:22 ` Johannes Thumshirn
2020-11-10 11:26 ` [PATCH v10 03/41] btrfs: introduce ZONED feature flag Naohiro Aota
2020-11-19 21:31 ` David Sterba
2020-11-10 11:26 ` [PATCH v10 04/41] btrfs: get zone information of zoned block devices Naohiro Aota
2020-11-12 6:57 ` Anand Jain
2020-11-12 7:35 ` Johannes Thumshirn
2020-11-12 7:44 ` Damien Le Moal
2020-11-12 9:44 ` Anand Jain
2020-11-13 21:34 ` David Sterba
2020-11-12 9:39 ` Johannes Thumshirn
2020-11-12 12:57 ` Naohiro Aota
2020-11-18 11:17 ` Anand Jain
2020-11-30 11:16 ` Anand Jain
2020-11-25 21:47 ` David Sterba
2020-11-25 22:07 ` David Sterba
2020-11-25 23:50 ` Damien Le Moal
2020-11-26 14:11 ` David Sterba
2020-11-25 22:16 ` David Sterba
2020-11-10 11:26 ` [PATCH v10 05/41] btrfs: check and enable ZONED mode Naohiro Aota
2020-11-18 11:29 ` Anand Jain
2020-11-27 18:44 ` David Sterba
2020-11-30 12:12 ` Anand Jain
2020-11-30 13:15 ` Damien Le Moal
2020-12-01 2:19 ` Anand Jain
2020-12-01 2:29 ` Damien Le Moal
2020-12-01 5:53 ` Anand Jain
2020-12-01 6:09 ` Damien Le Moal
2020-12-01 7:12 ` Anand Jain
2020-12-01 10:45 ` Graham Cobb
2020-12-01 11:03 ` Damien Le Moal
2020-12-01 11:11 ` hch
2020-12-01 11:27 ` Damien Le Moal
2020-11-10 11:26 ` [PATCH v10 06/41] btrfs: introduce max_zone_append_size Naohiro Aota
2020-11-19 9:23 ` Anand Jain
2020-11-27 18:47 ` David Sterba
2020-11-10 11:26 ` [PATCH v10 07/41] btrfs: disallow space_cache in ZONED mode Naohiro Aota
2020-11-19 10:42 ` Anand Jain
2020-11-20 4:08 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 08/41] btrfs: disallow NODATACOW " Naohiro Aota
2020-11-20 4:17 ` Anand Jain
2020-11-23 17:21 ` David Sterba
2020-11-24 3:29 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 09/41] btrfs: disable fallocate " Naohiro Aota
2020-11-20 4:28 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 10/41] btrfs: disallow mixed-bg " Naohiro Aota
2020-11-20 4:32 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
2020-11-23 17:46 ` David Sterba
2020-11-24 9:30 ` Johannes Thumshirn
2020-11-24 6:46 ` Anand Jain [this message]
2020-11-24 7:16 ` Hannes Reinecke
2020-11-10 11:26 ` [PATCH v10 12/41] btrfs: implement zoned chunk allocator Naohiro Aota
2020-11-24 11:36 ` Anand Jain
2020-11-25 1:57 ` Naohiro Aota
2020-11-25 7:17 ` Anand Jain
2020-11-25 11:48 ` Naohiro Aota
2020-11-25 9:59 ` Graham Cobb
2020-11-25 11:50 ` Naohiro Aota
2020-12-09 5:27 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 13/41] btrfs: verify device extent is aligned to zone Naohiro Aota
2020-11-27 6:27 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 14/41] btrfs: load zone's alloction offset Naohiro Aota
2020-12-08 9:54 ` Anand Jain
2020-11-10 11:26 ` [PATCH v10 15/41] btrfs: emulate write pointer for conventional zones Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 16/41] btrfs: track unusable bytes for zones Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 17/41] btrfs: do sequential extent allocation in ZONED mode Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 18/41] btrfs: reset zones of unused block groups Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 19/41] btrfs: redirty released extent buffers in ZONED mode Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 20/41] btrfs: extract page adding function Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 23/41] btrfs: split ordered extent when bio is sent Naohiro Aota
2020-11-11 2:01 ` kernel test robot
2020-11-11 2:26 ` kernel test robot
2020-11-11 3:46 ` kernel test robot
2020-11-11 3:46 ` [RFC PATCH] btrfs: extract_ordered_extent() can be static kernel test robot
2020-11-11 4:12 ` [PATCH v10.1 23/41] btrfs: split ordered extent when bio is sent Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 24/41] btrfs: extend btrfs_rmap_block for specifying a device Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 26/41] btrfs: enable zone append writing for direct IO Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 27/41] btrfs: introduce dedicated data write path for ZONED mode Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 28/41] btrfs: serialize meta IOs on " Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 29/41] btrfs: wait existing extents before truncating Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 30/41] btrfs: avoid async metadata checksum on ZONED mode Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 31/41] btrfs: mark block groups to copy for device-replace Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 32/41] btrfs: implement cloning for ZONED device-replace Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 33/41] btrfs: implement copying " Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 34/41] btrfs: support dev-replace in ZONED mode Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 35/41] btrfs: enable relocation " Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 36/41] btrfs: relocate block group to repair IO failure in ZONED Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 37/41] btrfs: split alloc_log_tree() Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group Naohiro Aota
2020-11-11 4:58 ` [PATCH v10.1 " Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 39/41] btrfs: serialize log transaction on ZONED mode Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 40/41] btrfs: reorder log node allocation Naohiro Aota
2020-11-10 11:26 ` [PATCH v10 41/41] btrfs: enable to mount ZONED incompat flag Naohiro Aota
2020-11-10 14:00 ` [PATCH v10 00/41] btrfs: zoned block device support Anand Jain
2020-11-11 5:07 ` Naohiro Aota
2020-11-27 19:28 ` David Sterba
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=69855ff1-4737-3d4c-f191-f31f8307fe88@oracle.com \
--to=anand.jain@oracle.com \
--cc=axboe@kernel.dk \
--cc=darrick.wong@oracle.com \
--cc=dsterba@suse.com \
--cc=hare@suse.com \
--cc=hch@infradead.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=naohiro.aota@wdc.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 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).