From: Al Viro <viro@ZenIV.linux.org.uk>
To: Nigel Cunningham <ncunningham@crca.org.au>
Cc: Josef Bacik <josef@redhat.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
chris.mason@oracle.com, hch@lst.de
Subject: Re: [PATCH] Introduce freeze_super and thaw_super for the fsfreeze ioctl
Date: Tue, 23 Mar 2010 23:47:19 +0000 [thread overview]
Message-ID: <20100323234719.GM30031@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20100323231802.GL30031@ZenIV.linux.org.uk>
On Tue, Mar 23, 2010 at 11:18:03PM +0000, Al Viro wrote:
> [snip the horror]
>
> a) traversing superblock list without any locking whatsoever
> b) accessing superblock fields <....>
> c) <.........................> without making sure that it's not
> going to disappear
> d) calling freeze_bdev() without any warranties that its argument
> is not going to be freed under you
> e) layering violations all over the place
> etc.
BTW, superblock can be kept alive by an opened file. umount -l, for example,
will give that. So it can get freed whenever the last reference to struct
file can go away (AF_UNIX garbage collection, etc.)
next prev parent reply other threads:[~2010-03-23 23:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-23 14:22 [PATCH] Introduce freeze_super and thaw_super for the fsfreeze ioctl Josef Bacik
2010-03-23 14:28 ` Al Viro
2010-03-23 14:34 ` Josef Bacik
2010-03-23 14:48 ` Al Viro
2010-03-23 15:03 ` Josef Bacik
2010-03-23 15:09 ` Al Viro
2010-03-23 15:12 ` Al Viro
2010-03-23 15:15 ` Al Viro
2010-03-23 22:31 ` Nigel Cunningham
2010-03-23 23:18 ` Al Viro
2010-03-23 23:47 ` Al Viro [this message]
2010-03-23 23:52 ` Nigel Cunningham
2010-03-23 23:55 ` Nigel Cunningham
2010-03-24 0:21 ` Al Viro
2010-03-24 0:25 ` Nigel Cunningham
2010-03-24 0:03 ` Nigel Cunningham
2010-03-23 18:19 ` Sunil Mushran
2010-03-23 22:25 ` Nigel Cunningham
2010-03-24 1:17 ` Josef Bacik
2010-03-24 5:16 ` Nigel Cunningham
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