From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chandra Seetharaman Subject: Re: [dm-devel] [PATCH 06/10] scsi_dh: Do not allow arguments for hardware handlers Date: Fri, 02 May 2008 17:01:07 -0700 Message-ID: <1209772867.21974.90.camel@chandra-ubuntu> References: <20080501214941.27759.95121.sendpatchset@chandra-ubuntu> <20080501215017.27759.37314.sendpatchset@chandra-ubuntu> <20080502224731.GH18935@agk.fab.redhat.com> Reply-To: sekharan@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080502224731.GH18935@agk.fab.redhat.com> Sender: linux-scsi-owner@vger.kernel.org To: Alasdair G Kergon Cc: linux-scsi@vger.kernel.org, andmike@us.ibm.com, michaelc@cs.wisc.edu, asson_ronald@emc.com, James.Bottomley@HansenPartnership.com, dm-devel@redhat.com, Benoit_Arthur@emc.com, jens.axboe@oracle.com List-Id: dm-devel.ids On Fri, 2008-05-02 at 23:47 +0100, Alasdair G Kergon wrote: > On Thu, May 01, 2008 at 02:50:17PM -0700, Chandra Seetharaman wrote: > > Subject: [PATCH 06/10] scsi_dh: Do not allow arguments for hardware handlers > > From: Chandra Seetharaman > > The new implementation does not use the arguments provided with the > > hardware handler. This patch makes the change visible to the user by > > failing table load when arguments are provided with the hardware handler. > > But then someone supplying such an arg may need to update their > userspace multipath config file before they can use this new kernel. > > Past experience suggests that changes like that usually come back > and bite us. Let's instead just have the kernel log a message noting > that the args have been ignored and allow people to deal with it at > their leisure. Understand. How does the following patch look ? -------------------- Subject: [PATCH 06/10] scsi_dh: Print warning when arguments were provided for hardware handlers From: Chandra Seetharaman The new implementation does not use the arguments provided with the hardware handler. This patch makes the change visible to the user by printing a warning to the kernel log. Signed-off-by: Chandra Seetharaman --- Index: linux-2.6.25/drivers/md/dm-mpath.c =================================================================== --- linux-2.6.25.orig/drivers/md/dm-mpath.c +++ linux-2.6.25/drivers/md/dm-mpath.c @@ -656,8 +656,11 @@ static int parse_hw_handler(struct arg_s {0, 1024, "invalid number of hardware handler args"}, }; - if (read_param(_params, shift(as), &hw_argc, &ti->error)) - return -EINVAL; + if (read_param(_params, shift(as), &hw_argc, &ti->error)) { + if (hw_argc > 1) + printk(KERN_WARN "Additional arguments provided to " + "hardware handler were ignored\n"); + } if (!hw_argc) return 0; ------------------------ > > Alasdair