From: Al Viro <viro@ZenIV.linux.org.uk>
To: Eric Paris <eparis@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org, hch@infradead.org,
zohar@us.ibm.com, warthog9@kernel.org, david@fromorbit.com,
jmorris@namei.org, kyle@mcmartin.ca, hpa@zytor.com,
akpm@linux-foundation.org, mingo@elte.hu
Subject: Re: [PATCH 1/3] IMA: move read/write counters into struct inode
Date: Tue, 19 Oct 2010 17:55:30 +0100 [thread overview]
Message-ID: <20101019165530.GT19804@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1287506215.2530.187.camel@localhost.localdomain>
On Tue, Oct 19, 2010 at 12:36:55PM -0400, Eric Paris wrote:
> I ask Al about reusing this field long ago and he indicated it had a
> very different meaning. I can't remember what he indicated it meant off
> the top of my head but I'll take a look at it again.
> i_count, I believe, is much different. i_count is counting the number
> of dentries in core referencing the inode, even if none of them are
> being used in any struct file or if one dentry is being referenced in
> 1000 struct files. The IMA counters are from a higher level, they
> counts the number of struct files referencing this inode.
a) i_writecount is about VM_DENYWRITE, basically. Reusing it for ima could
get unpleasant; when it's positive, we are fine, but it can get negative as
well. IMA will have interesting time dealing with that.
b) i_count is simply a refcount for struct inode. Not exactly the number
of dentries, but that's the main contributor. Basically, that's "how many
pointers outside of inode hash chains point that that struct inode at the
moment".
next prev parent reply other threads:[~2010-10-19 16:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-19 1:16 [PATCH 1/3] IMA: move read/write counters into struct inode Eric Paris
2010-10-19 1:16 ` [PATCH 2/3] IMA: only allocate iint when needed Eric Paris
2010-10-19 1:17 ` [PATCH 3/3] IMA: use rbtree instead of radix tree for inode information cache Eric Paris
2010-10-19 1:30 ` [PATCH 1/3] IMA: move read/write counters into struct inode Christoph Hellwig
2010-10-19 2:14 ` Eric Paris
2010-10-19 7:39 ` Dave Chinner
2010-10-19 16:24 ` Eric Paris
2010-10-19 16:29 ` Christoph Hellwig
2010-10-19 8:39 ` Ingo Molnar
2010-10-19 2:46 ` Eric Paris
2010-10-19 15:52 ` Linus Torvalds
2010-10-19 16:36 ` Eric Paris
2010-10-19 16:55 ` Al Viro [this message]
2010-10-19 17:03 ` Linus Torvalds
2010-10-19 17:28 ` Al Viro
2010-10-19 18:16 ` Mimi Zohar
2010-10-20 13:10 ` John Stoffel
2010-10-20 13:36 ` Al Viro
2010-10-20 14:09 ` John Stoffel
2010-10-19 19:11 ` Matthew Wilcox
2010-10-20 3:15 ` Al Viro
2010-10-20 17:38 ` J. Bruce Fields
2010-10-19 22:49 ` Eric Paris
2010-10-20 14:38 ` Ingo Molnar
2010-10-20 14:46 ` Eric Paris
2010-10-20 15:15 ` Ingo Molnar
2010-10-20 15:25 ` Eric Paris
2010-10-21 16:15 ` Casey Schaufler
2010-10-22 8:48 ` Ingo Molnar
2010-10-22 17:50 ` Casey Schaufler
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=20101019165530.GT19804@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=akpm@linux-foundation.org \
--cc=david@fromorbit.com \
--cc=eparis@redhat.com \
--cc=hch@infradead.org \
--cc=hpa@zytor.com \
--cc=jmorris@namei.org \
--cc=kyle@mcmartin.ca \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=torvalds@linux-foundation.org \
--cc=warthog9@kernel.org \
--cc=zohar@us.ibm.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).