From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mateusz Guzik Subject: Re: [PATCH V2 2/2] fs: print a message when freezing/unfreezing filesystems Date: Wed, 14 May 2014 13:26:21 +0200 Message-ID: <20140514112619.GA10637@mguzik.redhat.com> References: <1400018683-5565-1-git-send-email-mguzik@redhat.com> <1400018683-5565-2-git-send-email-mguzik@redhat.com> <20140514111449.GB5824@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Josef Bacik , Al Viro , Eric Sandeen , Joe Perches To: Jan Kara Return-path: Content-Disposition: inline In-Reply-To: <20140514111449.GB5824@quack.suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, May 14, 2014 at 01:14:49PM +0200, Jan Kara wrote: > On Wed 14-05-14 00:04:43, Mateusz Guzik wrote: > > This helps hang troubleshooting efforts when only dmesg is available. > > > > While here remove code duplication with MS_RDONLY case and fix a > > whitespace nit. > I'm somewhat undecided here I have to say. On one hand I don't like > printing to kernel log when everything is fine and kernel is operating > normally. On the other hand I've seen quite a few cases where people have > shot themselves in the foot with filesystem freezing so having some trace > of this in the log doesn't seem like a completely bad thing either. What do > other people think? > I would like to note that the kernel already prints messages when e.g. filesystems get mounted. And yes, situations where I/O is frozen and hung task detector comes into play happen more often than you may think. I can hide these behind a sysctl if this helps. Finally, somewhat related to the first mail, my preferred message format (which I was somewhat reluctant to propose earlier) would be: VFS (%s): Filesystem frozen by %s:%d with device, process and pid respectively. -- Mateusz Guzik