linux-kernel - Re: fuse: fix hang on SMP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Tue, 17 Oct 2006 15:43:05 +0200
From:	Miklos Szeredi <miklos@...redi.hu>
To:	ncmike@...ltra.org
CC:	akpm@...l.org, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: fuse: fix hang on SMP

> On 16/10/06 16:51 -0700, Andrew Morton wrote:
> >On Mon, 16 Oct 2006 18:27:10 +0200
> >Miklos Szeredi <miklos@...redi.hu> wrote:
> >
> >> Fuse didn't always call i_size_write() with i_mutex held which caused
> >> rare hangs on SMP/32bit.
> >
> >Yes, that is a bit of a trap.  I'll maintain a patch in -mm which spits a
> >warning if i_size_write() is called without i_mutex held.
> >
> 
> >+void i_size_write(struct inode *inode, loff_t i_size)
> >+{
> >+	WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
> 
> 
> Miklos' patch would generate this warning because he uses the spinlock
> inside struct fuse_conn to synchronize the write:

Yes, this will cause a false alarm for FUSE, but it may still be
useful to find similar bugs in other filesystems.

Miklos
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/