From: David Sterba <dsterba@suse.cz>
To: Timofey Titovets <nefelim4ag@gmail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 2/4] Btrfs: clear_dirty only on pages only in compression range
Date: Tue, 10 Oct 2017 18:22:28 +0200 [thread overview]
Message-ID: <20171010162228.GQ3521@twin.jikos.cz> (raw)
In-Reply-To: <20171003150604.19596-3-nefelim4ag@gmail.com>
On Tue, Oct 03, 2017 at 06:06:02PM +0300, Timofey Titovets wrote:
> We need to call extent_range_clear_dirty_for_io()
> on compression range to prevent application from changing
> page content, while pages compressing.
>
> but "(end - start)" can be much (up to 1024 times) bigger
> then compression range (BTRFS_MAX_UNCOMPRESSED), so optimize that
> by calculating compression range for
> that loop iteration, and flip bits only on that range
I'm not sure this is safe to do. Compress_file_range gets the whole
range [start,end] from async_cow_start, and other parts of code might
rely on the status of the whole range, ie. not partially redirtied.
next prev parent reply other threads:[~2017-10-10 16:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-03 15:06 [PATCH 0/4] Just bunch of btrfs patches Timofey Titovets
2017-10-03 15:06 ` [PATCH 1/4] Btrfs: compress_file_range() remove dead variable num_bytes Timofey Titovets
2017-10-10 17:39 ` David Sterba
2017-10-03 15:06 ` [PATCH 2/4] Btrfs: clear_dirty only on pages only in compression range Timofey Titovets
2017-10-10 16:22 ` David Sterba [this message]
2017-10-13 22:31 ` Timofey Titovets
2017-10-03 15:06 ` [PATCH 3/4] Btrfs: handle unaligned tail of data ranges more efficient Timofey Titovets
2017-10-10 16:37 ` David Sterba
2017-10-15 22:09 ` Timofey Titovets
2017-10-17 15:52 ` David Sterba
2017-10-03 15:06 ` [PATCH 4/4] Btrfs: btrfs_dedupe_file_range() ioctl, remove 16MiB restriction Timofey Titovets
2017-10-10 17:36 ` David Sterba
2017-11-14 10:19 ` Timofey Titovets
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=20171010162228.GQ3521@twin.jikos.cz \
--to=dsterba@suse.cz \
--cc=linux-btrfs@vger.kernel.org \
--cc=nefelim4ag@gmail.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.