From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH V5 1/5] virtio-scsi: redo allocation of target data Date: Tue, 19 Mar 2013 12:45:06 +0100 Message-ID: <51484FC2.6030601@redhat.com> References: <1363687057-13580-1-git-send-email-gaowanlong@cn.fujitsu.com> <1363687057-13580-2-git-send-email-gaowanlong@cn.fujitsu.com> <1363692727.2377.53.camel@dabdike.int.hansenpartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1363692727.2377.53.camel@dabdike.int.hansenpartnership.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: James Bottomley Cc: kvm@vger.kernel.org, linux-scsi@vger.kernel.org, mst@redhat.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org Il 19/03/2013 12:32, James Bottomley ha scritto: > On Tue, 2013-03-19 at 17:57 +0800, Wanlong Gao wrote: >> From: Paolo Bonzini >> >> virtio_scsi_target_state is now empty. We will find new uses for it in >> the next few patches, so this patch does not drop it completely. >> However, having dropped the sglist flexible array member, we can turn >> the tgt array-of-pointers into a simple array. This simplifies the >> allocation. >> >> Even simpler would be to place the virtio_scsi_target_state structs in a >> flexible array member at the end of struct virtio_scsi. But we do not >> do that, because we will place the virtqueues there in the next patches. > > I'm really sorry, but I must have been asleep at the wheel when I let > code like this go in. No modern driver should have fixed arrays for > target information. The way this is supposed to work is that you have > entries in the host template for target_alloc and target_destroy. You > hook into these and attach your struct virtio_scsi_target_state to > scsi_target->hostdata, So that would be sc->device->sdev_target->hostdata. > which you kmalloc in the target_alloc routine and > kfree in the target_destroy routine. Now you get at it from the sdev > with scsi_target(sdev)->hostdata. No messing around with fixed size > arrays and bulk memory allocation and no need to pass in the maximum > target size as a parameter because everything should now happen > dynamically. The maximum target size is not a module parameter, it is given by the host; so the module itself is not placing arbitrary limitation. Still it is a good idea to do it like this. Thanks for the review. Paolo > Since you're redoing the code anyway, can you fix it to work this way? > > Thanks, > > James > >