From: Hannes Reinecke <hare@suse.com>
To: Naohiro Aota <naota@elisp.net>, David Sterba <dsterba@suse.com>,
linux-btrfs@vger.kernel.org
Cc: Chris Mason <clm@fb.com>, Josef Bacik <jbacik@fb.com>,
linux-kernel@vger.kernel.org,
Damien Le Moal <damien.lemoal@wdc.com>,
Bart Van Assche <bart.vanassche@wdc.com>,
Matias Bjorling <mb@lightnvm.io>
Subject: Re: [RFC PATCH 00/17] btrfs zoned block device support
Date: Fri, 10 Aug 2018 09:26:03 +0200 [thread overview]
Message-ID: <9a37f119-5e9f-ef98-88a3-45c0f936d9ad@suse.com> (raw)
In-Reply-To: <20180809180450.5091-1-naota@elisp.net>
On 08/09/2018 08:04 PM, Naohiro Aota wrote:
> This series adds zoned block device support to btrfs.
>
> A zoned block device consists of a number of zones. Zones are either
> conventional and accepting random writes or sequential and requiring that
> writes be issued in LBA order from each zone write pointer position. This
> patch series ensures that the sequential write constraint of sequential
> zones is respected while fundamentally not changing BtrFS block and I/O
> management for block stored in conventional zones.
>
> To achieve this, the default dev extent size of btrfs is changed on zoned
> block devices so that dev extents are always aligned to a zone. Allocation
> of blocks within a block group is changed so that the allocation is always
> sequential from the beginning of the block groups. To do so, an allocation
> pointer is added to block groups and used as the allocation hint. The
> allocation changes also ensures that block freed below the allocation
> pointer are ignored, resulting in sequential block allocation regardless of
> the block group usage.
>
> While the introduction of the allocation pointer ensure that blocks will be
> allocated sequentially, I/Os to write out newly allocated blocks may be
> issued out of order, causing errors when writing to sequential zones. This
> problem s solved by introducing a submit_buffer() function and changes to
> the internal I/O scheduler to ensure in-order issuing of write I/Os for
> each chunk and corresponding to the block allocation order in the chunk.
>
> The zones of a chunk are reset to allow reusing of the zone only when the
> block group is being freed, that is, when all the extents of the block group
> are unused.
>
> For btrfs volumes composed of multiple zoned disks, restrictions are added
> to ensure that all disks have the same zone size. This matches the existing
> constraint that all dev extents in a chunk must have the same size.
>
> It requires zoned block devices to test the patchset. Even if you don't
> have zone devices, you can use tcmu-runner [1] to emulate zoned block
> devices. It can export emulated zoned block devices via iSCSI. Please see
> the README.md of tcmu-runner [2] for howtos to generate a zoned block
> device on tcmu-runner.
>
> [1] https://github.com/open-iscsi/tcmu-runner
> [2] https://github.com/open-iscsi/tcmu-runner/blob/master/README.md
>
> Patch 1 introduces the HMZONED incompatible feature flag to indicate that
> the btrfs volume was formatted for use on zoned block devices.
>
> Patches 2 and 3 implement functions to gather information on the zones of
> the device (zones type and write pointer position).
>
> Patch 4 restrict the possible locations of super blocks to conventional
> zones to preserve the existing update in-place mechanism for the super
> blocks.
>
> Patches 5 to 7 disable features which are not compatible with the sequential
> write constraints of zoned block devices. This includes fallocate and
> direct I/O support. Device replace is also disabled for now.
>
> Patches 8 and 9 tweak the extent buffer allocation for HMZONED mode to
> implement sequential block allocation in block groups and chunks.
>
> Patches 10 to 12 implement the new submit buffer I/O path to ensure sequential
> write I/O delivery to the device zones.
>
> Patches 13 to 16 modify several parts of btrfs to handle free blocks
> without breaking the sequential block allocation and sequential write order
> as well as zone reset for unused chunks.
>
> Finally, patch 17 adds the HMZONED feature to the list of supported
> features.
>
> Naohiro Aota (17):
> btrfs: introduce HMZONED feature flag
> btrfs: Get zone information of zoned block devices
> btrfs: Check and enable HMZONED mode
> btrfs: limit super block locations in HMZONED mode
> btrfs: disable fallocate in HMZONED mode
> btrfs: disable direct IO in HMZONED mode
> btrfs: disable device replace in HMZONED mode
> btrfs: align extent allocation to zone boundary
> btrfs: do sequential allocation on HMZONED drives
> btrfs: split btrfs_map_bio()
> btrfs: introduce submit buffer
> btrfs: expire submit buffer on timeout
> btrfs: avoid sync IO prioritization on checksum in HMZONED mode
> btrfs: redirty released extent buffers in sequential BGs
> btrfs: reset zones of unused block groups
> btrfs: wait existing extents before truncating
> btrfs: enable to mount HMZONED incompat flag
>
And unfortunately this series fails to boot for me:
BTRFS error (device nvme0n1p5): zoned devices mixed with regular devices
BTRFS error (device nvme0n1p5): failed to init hmzoned mode: -22
BTRFS error (device nvme0n1p5): open_ctree failed
Needless to say, /dev/nvme0n1p5 is _not_ a zoned device.
Nor has the zoned device a btrfs superblock ATM.
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.com +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
next prev parent reply other threads:[~2018-08-10 7:26 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-09 18:04 [RFC PATCH 00/17] btrfs zoned block device support Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 01/17] btrfs: introduce HMZONED feature flag Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 02/17] btrfs: Get zone information of zoned block devices Naohiro Aota
2018-08-10 7:41 ` Nikolay Borisov
2018-08-09 18:04 ` [RFC PATCH 03/17] btrfs: Check and enable HMZONED mode Naohiro Aota
2018-08-10 12:25 ` Hannes Reinecke
2018-08-10 13:15 ` Naohiro Aota
2018-08-10 13:41 ` Hannes Reinecke
2018-08-09 18:04 ` [RFC PATCH 04/17] btrfs: limit super block locations in " Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 05/17] btrfs: disable fallocate " Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 06/17] btrfs: disable direct IO " Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 07/17] btrfs: disable device replace " Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 08/17] btrfs: align extent allocation to zone boundary Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 09/17] btrfs: do sequential allocation on HMZONED drives Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 10/17] btrfs: split btrfs_map_bio() Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 11/17] btrfs: introduce submit buffer Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 12/17] btrfs: expire submit buffer on timeout Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 13/17] btrfs: avoid sync IO prioritization on checksum in HMZONED mode Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 14/17] btrfs: redirty released extent buffers in sequential BGs Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 15/17] btrfs: reset zones of unused block groups Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 16/17] btrfs: wait existing extents before truncating Naohiro Aota
2018-08-09 18:04 ` [RFC PATCH 17/17] btrfs: enable to mount HMZONED incompat flag Naohiro Aota
2018-08-09 18:10 ` [RFC PATCH 01/12] btrfs-progs: build: Check zoned block device support Naohiro Aota
2018-08-09 18:10 ` [RFC PATCH 02/12] btrfs-progs: utils: Introduce queue_param Naohiro Aota
2018-08-09 18:10 ` [RFC PATCH 03/12] btrfs-progs: add new HMZONED feature flag Naohiro Aota
2018-08-09 18:10 ` [RFC PATCH 04/12] btrfs-progs: Introduce zone block device helper functions Naohiro Aota
2018-08-09 18:10 ` [RFC PATCH 05/12] btrfs-progs: load and check zone information Naohiro Aota
2018-08-09 18:10 ` [RFC PATCH 06/12] btrfs-progs: avoid writing super block to sequential zones Naohiro Aota
2018-08-09 18:11 ` [RFC PATCH 07/12] btrfs-progs: support discarding zoned device Naohiro Aota
2018-08-09 18:11 ` [RFC PATCH 08/12] btrfs-progs: volume: align chunk allocation to zones Naohiro Aota
2018-08-09 18:11 ` [RFC PATCH 09/12] btrfs-progs: mkfs: Zoned block device support Naohiro Aota
2018-08-09 18:11 ` [RFC PATCH 10/12] btrfs-progs: device-add: support HMZONED device Naohiro Aota
2018-08-09 18:11 ` [RFC PATCH 11/12] btrfs-progs: replace: disable in " Naohiro Aota
2018-08-09 18:11 ` [RFC PATCH 12/12] btrfs-progs: do sequential allocation Naohiro Aota
2018-08-10 7:04 ` [RFC PATCH 00/17] btrfs zoned block device support Hannes Reinecke
2018-08-10 14:24 ` Naohiro Aota
2018-08-10 7:26 ` Hannes Reinecke [this message]
2018-08-10 7:28 ` Qu Wenruo
2018-08-16 9:05 ` Naohiro Aota
2018-08-10 7:53 ` Nikolay Borisov
2018-08-10 7:55 ` Nikolay Borisov
2018-08-13 18:42 ` David Sterba
2018-08-13 19:20 ` Hannes Reinecke
2018-08-13 19:29 ` Austin S. Hemmelgarn
2018-08-14 7:41 ` Hannes Reinecke
2018-08-15 11:25 ` Austin S. Hemmelgarn
2018-08-28 10:33 ` Naohiro Aota
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=9a37f119-5e9f-ef98-88a3-45c0f936d9ad@suse.com \
--to=hare@suse.com \
--cc=bart.vanassche@wdc.com \
--cc=clm@fb.com \
--cc=damien.lemoal@wdc.com \
--cc=dsterba@suse.com \
--cc=jbacik@fb.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mb@lightnvm.io \
--cc=naota@elisp.net \
/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).