From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: Re: [PATCH v2] xen-block: handle resize callback Date: Thu, 31 Jan 2019 15:25:02 +0000 Message-ID: <20190131152502.GG2306@perard.uk.xensource.com> References: <20190130161948.15888-1-paul.durrant@citrix.com> <20190131152042.GF2306@perard.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1gpEGM-0007iw-SS for xen-devel@lists.xenproject.org; Thu, 31 Jan 2019 15:28:22 +0000 Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: Paul Durrant Cc: Kevin Wolf , Stefano Stabellini , "qemu-block@nongnu.org" , "qemu-devel@nongnu.org" , Max Reitz , Stefan Hajnoczi , "xen-devel@lists.xenproject.org" List-Id: xen-devel@lists.xenproject.org T24gVGh1LCBKYW4gMzEsIDIwMTkgYXQgMDM6MjI6MThQTSArMDAwMCwgUGF1bCBEdXJyYW50IHdy b3RlOgo+ID4gLS0tLS1PcmlnaW5hbCBNZXNzYWdlLS0tLS0KPiA+IEZyb206IEFudGhvbnkgUEVS QVJEIFttYWlsdG86YW50aG9ueS5wZXJhcmRAY2l0cml4LmNvbV0KPiA+IFNlbnQ6IDMxIEphbnVh cnkgMjAxOSAxNToyMQo+ID4gVG86IFBhdWwgRHVycmFudCA8UGF1bC5EdXJyYW50QGNpdHJpeC5j b20+Cj4gPiBDYzogcWVtdS1kZXZlbEBub25nbnUub3JnOyBxZW11LWJsb2NrQG5vbmdudS5vcmc7 IHhlbi0KPiA+IGRldmVsQGxpc3RzLnhlbnByb2plY3Qub3JnOyBTdGVmYW4gSGFqbm9jemkgPHN0 ZWZhbmhhQHJlZGhhdC5jb20+OyBTdGVmYW5vCj4gPiBTdGFiZWxsaW5pIDxzc3RhYmVsbGluaUBr ZXJuZWwub3JnPjsgS2V2aW4gV29sZiA8a3dvbGZAcmVkaGF0LmNvbT47IE1heAo+ID4gUmVpdHog PG1yZWl0ekByZWRoYXQuY29tPgo+ID4gU3ViamVjdDogUmU6IFtQQVRDSCB2Ml0geGVuLWJsb2Nr OiBoYW5kbGUgcmVzaXplIGNhbGxiYWNrCj4gPiAKPiA+IE9uIFdlZCwgSmFuIDMwLCAyMDE5IGF0 IDA0OjE5OjQ4UE0gKzAwMDAsIFBhdWwgRHVycmFudCB3cm90ZToKPiA+ID4gU29tZSBmcm9udGVu ZCBkcml2ZXJzIHdpbGwgaGFuZGxlIGR5bmFtaWMgcmVzaXppbmcgb2YgUFYgZGlza3MsIHNvIHNl dAo+ID4gdXAKPiA+ID4gdGhlIEJsb2NrRGV2T3BzIHJlc2l6ZV9jYigpIG1ldGhvZCBkdXJpbmcg eGVuX2Jsb2NrX3JlYWxpemUoKSB0byBhbGxvdwo+ID4gPiB0aGlzIHRvIGJlIGRvbmUuCj4gPiA+ Cj4gPiA+IFNpZ25lZC1vZmYtYnk6IFBhdWwgRHVycmFudCA8cGF1bC5kdXJyYW50QGNpdHJpeC5j b20+Cj4gPiA+IC0tLQo+ID4gCj4gPiAKPiA+ID4gKyAgICAvKgo+ID4gPiArICAgICAqIE1pbWlj IHRoZSBiZWhhdmlvdXIgb2YgTGludXggeGVuLWJsa2JhY2sgYW5kIHJlLXdyaXRlIHRoZSBzdGF0 ZQo+ID4gPiArICAgICAqIHRvIHRyaWdnZXIgdGhlIGZyb250ZW5kIHdhdGNoLgo+ID4gPiArICAg ICAqLwo+ID4gPiArICAgIHhlbl9kZXZpY2VfYmFja2VuZF9zZXRfc3RhdGUoeGVuZGV2LCBiYWNr ZW5kX3N0YXRlKTsKPiA+IAo+ID4gOigsIHRoYXQgZnVuY3Rpb24gZG9lc24ndCB3cml0ZSB0aGUg c3RhdGUgYWdhaW4gaWYgaXQgaGFzbid0IGNoYW5nZWQuCj4gPiBTbyBpbiBteSB0ZXN0aW5nLCBM aW51eCBuZXZlciBkaWQgYW55dGhpbmcuCj4gCj4gR2FoISBJIGZvcmdvdCBhYm91dCB0aGF0LiBB bHJpZ2h0LCBpdCdzIGdvaW5nIHRvIGhhdmUgdG8gYmUgYSBiaXQgbW9yZSBjcnVkZS4KCm1vcmUg Y3J1ZGUgPiBZZXMsIEkgdHJpZWQgdG8gaWdub3JlIHRoZSBjaGVjayBpbiBfc2V0X3N0YXRlIGFu ZCBlbmQtdXAKd2l0aCBhbiBpbmZpbml0IGxvb3AuCgotLSAKQW50aG9ueSBQRVJBUkQKCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhlbi1kZXZlbCBtYWls aW5nIGxpc3QKWGVuLWRldmVsQGxpc3RzLnhlbnByb2plY3Qub3JnCmh0dHBzOi8vbGlzdHMueGVu cHJvamVjdC5vcmcvbWFpbG1hbi9saXN0aW5mby94ZW4tZGV2ZWw= From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:49492) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gpEGN-0001AP-UO for qemu-devel@nongnu.org; Thu, 31 Jan 2019 10:28:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gpEGN-00031W-21 for qemu-devel@nongnu.org; Thu, 31 Jan 2019 10:28:23 -0500 Date: Thu, 31 Jan 2019 15:25:02 +0000 From: Anthony PERARD Message-ID: <20190131152502.GG2306@perard.uk.xensource.com> References: <20190130161948.15888-1-paul.durrant@citrix.com> <20190131152042.GF2306@perard.uk.xensource.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v2] xen-block: handle resize callback List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Durrant Cc: "qemu-devel@nongnu.org" , "qemu-block@nongnu.org" , "xen-devel@lists.xenproject.org" , Stefan Hajnoczi , Stefano Stabellini , Kevin Wolf , Max Reitz On Thu, Jan 31, 2019 at 03:22:18PM +0000, Paul Durrant wrote: > > -----Original Message----- > > From: Anthony PERARD [mailto:anthony.perard@citrix.com] > > Sent: 31 January 2019 15:21 > > To: Paul Durrant > > Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; xen- > > devel@lists.xenproject.org; Stefan Hajnoczi ; Stefano > > Stabellini ; Kevin Wolf ; Max > > Reitz > > Subject: Re: [PATCH v2] xen-block: handle resize callback > > > > On Wed, Jan 30, 2019 at 04:19:48PM +0000, Paul Durrant wrote: > > > Some frontend drivers will handle dynamic resizing of PV disks, so set > > up > > > the BlockDevOps resize_cb() method during xen_block_realize() to allow > > > this to be done. > > > > > > Signed-off-by: Paul Durrant > > > --- > > > > > > > + /* > > > + * Mimic the behaviour of Linux xen-blkback and re-write the state > > > + * to trigger the frontend watch. > > > + */ > > > + xen_device_backend_set_state(xendev, backend_state); > > > > :(, that function doesn't write the state again if it hasn't changed. > > So in my testing, Linux never did anything. > > Gah! I forgot about that. Alright, it's going to have to be a bit more crude. more crude > Yes, I tried to ignore the check in _set_state and end-up with an infinit loop. -- Anthony PERARD