From: Al Viro <viro@ZenIV.linux.org.uk>
To: Jan Kara <jack@suse.cz>
Cc: akpm@linux-foundation.org, fabf@skynet.be,
mm-commits@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: Elevated i_writecount doesn't guarantee ->release to be called
Date: Thu, 29 Jan 2015 17:35:33 +0000 [thread overview]
Message-ID: <20150129173532.GF29656@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20150129124630.GB11635@quack.suse.cz>
On Thu, Jan 29, 2015 at 01:46:30PM +0100, Jan Kara wrote:
> Thanks for pointing this out. You made me at look where exactly is
> get_write_access() called and there are even places where we call it
> without having file descriptor at all (e.g. truncate path). So ext3, ext4,
> udf, and gfs2 are racy. If we race, results aren't that bad (we just keep
> preallocated blocks in the inode) but still it would be nice to fix.
>
> Obviously we could maintain a private writecount in ->open() method but it
> would seem a bit sad to do that for this mostly theoretical issue. Maybe we
> just verify whether preallocation is truncated when evicting inode from
> memory and if not, do it there. It's not perfect but even with current racy
> solution noone noticed in practice.
The trouble with doing that on inode eviction is that we might have done
r/o remount by then, so any metadata writes are unexpected at that point...
next prev parent reply other threads:[~2015-01-29 17:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-28 21:45 + fs-affs-use-inode-writecount-instead-of-local-i_opencnt.patch added to -mm tree akpm
[not found] ` <20150128224534.GB29656@ZenIV.linux.org.uk>
2015-01-29 12:46 ` Elevated i_writecount doesn't guarantee ->release to be called Jan Kara
2015-01-29 16:47 ` Fabian Frederick
2015-01-29 16:57 ` Jan Kara
2015-01-29 17:35 ` Al Viro [this message]
2015-01-30 5:33 ` Fabian Frederick
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=20150129173532.GF29656@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=akpm@linux-foundation.org \
--cc=fabf@skynet.be \
--cc=jack@suse.cz \
--cc=linux-fsdevel@vger.kernel.org \
--cc=mm-commits@vger.kernel.org \
/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.