From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa1.hgst.iphmx.com ([68.232.141.245]:58034 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752259AbdIVRyv (ORCPT ); Fri, 22 Sep 2017 13:54:51 -0400 From: Bart Van Assche To: "ming.lei@redhat.com" CC: "dm-devel@redhat.com" , "hch@infradead.org" , "linux-block@vger.kernel.org" , "axboe@fb.com" , "snitzer@redhat.com" , "loberman@redhat.com" Subject: Re: [PATCH] dm-mpath: return DM_MAPIO_REQUEUE in case of rq allocation failure Date: Fri, 22 Sep 2017 17:54:48 +0000 Message-ID: <1506102888.2512.9.camel@wdc.com> References: <20170922013506.22510-1-ming.lei@redhat.com> <1506092775.2512.5.camel@wdc.com> <20170922174431.GA21108@ming.t460p> In-Reply-To: <20170922174431.GA21108@ming.t460p> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org T24gU2F0LCAyMDE3LTA5LTIzIGF0IDAxOjQ0ICswODAwLCBNaW5nIExlaSB3cm90ZToNCj4gT24g RnJpLCBTZXAgMjIsIDIwMTcgYXQgMDM6MDY6MTZQTSArMDAwMCwgQmFydCBWYW4gQXNzY2hlIHdy b3RlOg0KPiA+IE9uIEZyaSwgMjAxNy0wOS0yMiBhdCAwOTozNSArMDgwMCwgTWluZyBMZWkgd3Jv dGU6DQo+ID4gPiArCQkvKg0KPiA+ID4gKwkJICogYmxrLW1xJ3MgU0NIRURfUkVTVEFSVCBjYW4g Y292ZXIgdGhpcyByZXF1ZXVlLCBzbw0KPiA+ID4gKwkJICogd2UgbmVlZG4ndCB0byBkZWFsIHdp dGggaXQgYnkgREVMQVlfUkVRVUVVRS4gTW9yZQ0KPiA+ID4gKwkJICogaW1wb3J0YW50bHksIHdl IGhhdmUgdG8gcmV0dXJuIERNX01BUElPX1JFUVVFVUUNCj4gPiA+ICsJCSAqIHNvIHRoYXQgYmxr LW1xIGNhbiBnZXQgdGhlIHF1ZXVlIGJ1c3kgZmVlZGJhY2ssDQo+ID4gPiArCQkgKiBvdGhlcndp c2UgSS9PIG1lcmdlIGNhbiBiZSBodXJ0Lg0KPiA+ID4gKwkJICovDQo+ID4gPiArCQlpZiAocS0+ bXFfb3BzKQ0KPiA+ID4gKwkJCXJldHVybiBETV9NQVBJT19SRVFVRVVFOw0KPiA+ID4gKwkJZWxz ZQ0KPiA+ID4gKwkJCXJldHVybiBETV9NQVBJT19ERUxBWV9SRVFVRVVFOw0KPiA+ID4gIAl9DQo+ ID4gDQo+ID4gVGhpcyBwYXRjaCBpcyBpbmZlcmlvciB0byB3aGF0IEkgcG9zdGVkIGJlY2F1c2Ug dGhpcyBwYXRjaCBkb2VzIG5vdCBhdm9pZA0KPiA+IHRoZSBkZWxheSBpZiBtdWx0aXBsZSBMVU5z IGFyZSBhc3NvY2lhdGVkIHdpdGggdGhlIHNhbWUgU0NTSSBob3N0LiBDb25zaWRlcg0KPiA+IGUu Zy4gdGhlIGZvbGxvd2luZyBjb25maWd1cmF0aW9uOg0KPiA+ICogQSBzaW5nbGUgU0NTSSBob3N0 IHdpdGggdHdvIFNDU0kgTFVOcyBhc3NvY2lhdGVkIHRvIHRoYXQgaG9zdCwgZS5nLiAvZGV2L3Nk YQ0KPiA+ICAgYW5kIC9kZXYvc2RiLg0KPiA+ICogQSBkbS1tcGF0aCBpbnN0YW5jZSBoYXMgYmVl biBjcmVhdGVkIG9uIHRvcCBvZiAvZGV2L3NkYS4NCj4gPiBJZiBhbGwgdGFncyBhcmUgaW4gdXNl IGJ5IHJlcXVlc3RzIHF1ZXVlZCB0byAvZGV2L3NkYiwgbm8gZG0gcmVxdWVzdHMgYXJlIGluDQo+ ID4gcHJvZ3Jlc3MgYW5kIGEgcmVxdWVzdCBpcyBzdWJtaXR0ZWQgYWdhaW5zdCB0aGUgZG0tbXBh dGggZGV2aWNlIHRoZW4gdGhlDQo+ID4gYmxrX2dldF9yZXF1ZXN0KHEsIEdGUF9BVE9NSUMpIGNh bGwgd2lsbCBmYWlsLiBUaGUgcmVxdWVzdCB3aWxsIGJlIHJlcXVldWVkDQo+ID4gYW5kIHRoZSBx dWV1ZSB3aWxsIGJlIHJlcnVuIGFmdGVyIGEgZGVsYXkuDQo+ID4gDQo+ID4gTXkgcGF0Y2ggZG9l cyBub3QgaW50cm9kdWNlIGEgZGVsYXkgaW4gdGhpcyBjYXNlLg0KPiANCj4gVGhhdCBkZWxheSBt YXkgbm90IG1hdHRlciBiZWNhdXNlIFNDSEVEX1JFU1RBUlQgd2lsbCBydW4gcXVldWUganVzdA0K PiBhZnRlciBvbmUgcmVxdWVzdCBpcyBjb21wbGV0ZWQuDQoNCkRpZCB5b3UgdW5kZXJzdGFuZCB3 aGF0IEkgd3JvdGU/IFNDSEVEX1JFU1RBUlQgd2lsbCBiZSBzZXQgZm9yIC9kZXYvc2RiIGJ1dCBu b3QNCmZvciB0aGUgZG0gcXVldWUuIFRoYXQncyB3aGF0IEkgd2FzIHRyeWluZyB0byBleHBsYWlu IHRvIHlvdSBpbiBteSBwcmV2aW91cyBlLW1haWwuDQoNCj4gVGhlcmUgaXMgYXQgbGVhc3Qgb25l IGlzc3VlIHdpdGggZ2V0X3JlcXVlc3QoR0ZQX05PSU8pOiBBSU8NCj4gcGVyZm9ybWFuY2UgcmVn cmVzc2lvbiBtYXkgbm90IGJlIGNhdXNlZCwgb3IgZXZlbiBBSU8gbWF5IG5vdA0KPiBiZSBwb3Nz aWJsZS4gRm9yIGV4YW1wbGUsIHVzZXIgcnVucyBmaW8obGliYWlvLCByYW5kcmVhZCwgc2luZ2xl DQo+IGpvYiwgcXVldWUgZGVwdGg6IDY0LCBkZXZpY2U6IGRtLW1wYXRoIGRpc2spLCBpZiBnZXRf cmVxdWVzdChHRlBfTk9JTykNCj4gb2Z0ZW4gYmxvY2tzIGJlY2F1c2Ugb2Ygc2hhcmVkIHRhZ3Mg b3Igb3V0IG9mIHRhZywgdGhlIGFjdHVhbCBxdWV1ZQ0KPiBkZXB0aCB3b24ndCByZWFjaCA2NCBh dCBhbGwsIGFuZCBtYXkgYmUganVzdCAxIGluIHRoZSB3b3JzdCBjYXNlLg0KPiBPbmNlIHRoZSBh Y3R1YWwgcXVldWUgZGVwdGggaXMgZGVjcmVhc2VkIG11Y2gsIHJhbmRvbSBJL08gcGVyZm9ybWFu Y2UNCj4gc2hvdWxkIGJlIGh1cnQgYSBsb3QuDQoNClRoYXQncyB3aHkgd2UgbmVlZCB0byBtb2Rp Znkgc2NzaV9sbGRfYnVzeSgpLiBJZiBzY3NpX2xsZF9idXN5KCkgd2lsbCBiZQ0KbW9kaWZpZWQg YXMgSSBwcm9wb3NlZCBpbiBhIHByZXZpb3VzIGUtbWFpbCB0aGVuIGl0IHdpbGwgYmVjb21lIHZl cnkNCnVubGlrZWx5IHRoYXQgbm8gdGFnIGlzIGF2YWlsYWJsZSB3aGVuIGJsa19nZXRfcmVxdWVz dCgpIGlzIGNhbGxlZC4gV2l0aCB0aGF0DQpzY3NpX2xsZF9idXN5KCkgbW9kaWZpY2F0aW9uIGl0 IGlzIGV2ZW4gcG9zc2libGUgdGhhdCB3ZSBkb24ndCBuZWVkIHRvIG1vZGlmeQ0KdGhlIGRtLW1w YXRoIGRyaXZlci4NCg0KQmFydC4=