From: Zach Brown <zab@zabbo.net>
To: Ric Wheeler <rwheeler@redhat.com>, Jan Kara <jack@suse.cz>,
Eric Sandeen <sandeen@redhat.com>, Theodore Ts'o <tytso@mit.edu>,
Fredrick <fjohnber@zoho.com>,
linux-ext4@vger.kernel.org, Andreas Dilger <adilger@dilger.ca>,
wenqing.lz@taobao.com
Subject: Re: ext4_fallocate
Date: Tue, 03 Jul 2012 10:57:35 -0700 [thread overview]
Message-ID: <4FF3328F.3090301@zabbo.net> (raw)
In-Reply-To: <20120703174147.GA14986@gmail.com>
> workload frequently does a uninitialized extent conversion. Thus, now
> we set it to 256 (1MB chunk), and put it into super block in order to
> adjust it dynamically in sysfs.
It's a bit of a tangent, but this caught my eye.
> + /* If extent has less than 2*s_extent_zeroout_len zerout directly */
> + if (ee_len<= 2*sbi->s_extent_zeroout_len&&
> (EXT4_EXT_MAY_ZEROOUT& split_flag)) {
> - if (allocated<= EXT4_EXT_ZERO_LEN&&
> + if (allocated<= sbi->s_extent_zeroout_len&&
> (EXT4_EXT_MAY_ZEROOUT& split_flag)) {
> } else if ((map->m_lblk - ee_block + map->m_len<
> - EXT4_EXT_ZERO_LEN)&&
> + sbi->s_extent_zeroout_len)&&
I'd be worried about having to verify that nothing bad happened if these
sbi s_extent_zeroout_len references could see different values if they
raced with a sysfs update. Can they do that?
Maybe avoid the risk all together and have an on-stack copy that's only
referenced once at the start?
- z
next prev parent reply other threads:[~2012-07-03 18:04 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-25 6:42 ext4_fallocate Fredrick
2012-06-25 7:33 ` ext4_fallocate Andreas Dilger
2012-06-28 15:12 ` ext4_fallocate Phillip Susi
2012-06-28 15:23 ` ext4_fallocate Eric Sandeen
2012-06-25 8:51 ` ext4_fallocate Zheng Liu
2012-06-25 19:04 ` ext4_fallocate Fredrick
2012-06-25 19:17 ` ext4_fallocate Theodore Ts'o
2012-06-26 1:23 ` ext4_fallocate Fredrick
2012-06-26 13:13 ` ext4_fallocate Ric Wheeler
2012-06-26 17:30 ` ext4_fallocate Theodore Ts'o
2012-06-26 18:06 ` ext4_fallocate Fredrick
2012-06-26 18:21 ` ext4_fallocate Ric Wheeler
2012-06-26 18:57 ` ext4_fallocate Ted Ts'o
2012-06-26 19:22 ` ext4_fallocate Ric Wheeler
2012-06-26 18:05 ` ext4_fallocate Fredrick
2012-06-26 18:59 ` ext4_fallocate Ted Ts'o
2012-06-26 19:30 ` ext4_fallocate Ric Wheeler
2012-06-26 19:57 ` ext4_fallocate Eric Sandeen
2012-06-26 20:44 ` ext4_fallocate Eric Sandeen
2012-06-27 15:14 ` ext4_fallocate Eric Sandeen
2012-06-27 19:30 ` ext4_fallocate Theodore Ts'o
2012-06-27 23:02 ` ext4_fallocate Eric Sandeen
2012-06-28 11:27 ` ext4_fallocate Ric Wheeler
2012-06-29 19:02 ` ext4_fallocate Andreas Dilger
2012-07-02 3:03 ` ext4_fallocate Zheng Liu
2012-06-28 12:48 ` ext4_fallocate Theodore Ts'o
2012-07-02 3:16 ` ext4_fallocate Zheng Liu
2012-07-02 16:33 ` ext4_fallocate Eric Sandeen
2012-07-02 17:44 ` ext4_fallocate Jan Kara
2012-07-02 17:48 ` ext4_fallocate Ric Wheeler
2012-07-03 17:41 ` ext4_fallocate Zheng Liu
2012-07-03 17:57 ` Zach Brown [this message]
2012-07-04 2:23 ` ext4_fallocate Zheng Liu
2012-07-02 18:01 ` ext4_fallocate Theodore Ts'o
2012-07-03 9:30 ` ext4_fallocate Jan Kara
2012-07-04 1:15 ` ext4_fallocate Phillip Susi
2012-07-04 2:36 ` ext4_fallocate Zheng Liu
2012-07-04 3:06 ` ext4_fallocate Phillip Susi
2012-07-04 3:48 ` ext4_fallocate Zheng Liu
2012-07-04 12:20 ` ext4_fallocate Ric Wheeler
2012-07-04 13:25 ` ext4_fallocate Zheng Liu
2012-06-26 13:06 ` ext4_fallocate Eric Sandeen
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=4FF3328F.3090301@zabbo.net \
--to=zab@zabbo.net \
--cc=adilger@dilger.ca \
--cc=fjohnber@zoho.com \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=rwheeler@redhat.com \
--cc=sandeen@redhat.com \
--cc=tytso@mit.edu \
--cc=wenqing.lz@taobao.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.