From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "tj@kernel.org" CC: "linux-block@vger.kernel.org" , "israelr@mellanox.com" , "sagi@grimberg.me" , "hch@lst.de" , "martin@lichtvoll.de" , "stable@vger.kernel.org" , "axboe@kernel.dk" , "ming.lei@redhat.com" , "maxg@mellanox.com" Subject: Re: [PATCH v4] blk-mq: Fix race conditions in request timeout handling Date: Wed, 11 Apr 2018 12:50:51 +0000 Message-ID: References: <20180410135541.GA22340@ming.t460p> <7c4a8b019182d5a9259ef20e6462b3f6a533abed.camel@wdc.com> <20180410143007.GB22340@ming.t460p> <20180410152553.GC22340@ming.t460p> <20180410153031.GO3126663@devbig577.frc2.facebook.com> <20180410153812.GA3219@ming.t460p> <20180410154043.GP3126663@devbig577.frc2.facebook.com> <20180410213323.GC793541@devbig577.frc2.facebook.com> <20180410215456.GD793541@devbig577.frc2.facebook.com> In-Reply-To: <20180410215456.GD793541@devbig577.frc2.facebook.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gVHVlLCAyMDE4LTA0LTEwIGF0IDE0OjU0IC0wNzAwLCB0akBrZXJuZWwub3JnIHdyb3RlOg0K PiBBaCwgeWVhaCwgSSB3YXMgbW92aW5nIGl0IG91dCBvZiBhZGRfdGltZXIgYnV0IGZvcmdvdCB0 byBhY3R1bGx5IGFkZA0KPiBpdCB0byB0aGUgaXNzdWUgcGF0aC4gIEZpeGVkIHBhdGNoIGJlbG93 Lg0KPiANCj4gQlRXLCBubyBtYXR0ZXIgd2hhdCB3ZSBkbyB3LyB0aGUgcmVxdWVzdCBoYW5kb3Zl ciBiZXR3ZWVuIG5vcm1hbCBhbmQNCj4gdGltZW91dCBwYXRocywgd2UnZCBuZWVkIHNvbWV0aGlu ZyBzaW1pbGFyLiAgT3RoZXJ3aXNlLCB3aGlsZSB3ZSBjYW4NCj4gcmVkdWNlIHRoZSB3aW5kb3cs IHdlIGNhbid0IGdldCByaWQgb2YgaXQuDQoNCigrTWFydGluIFN0ZWlnZXJ3YWxkKQ0KDQpIZWxs byBUZWp1biwNCg0KVGhhbmsgeW91IGZvciBoYXZpbmcgc2hhcmVkIHRoaXMgcGF0Y2guIEl0IGxv b2tzIGludGVyZXN0aW5nIHRvIG1lLiBXaGF0IEkNCmtub3cgYWJvdXQgdGhlIGJsay1tcSB0aW1l b3V0IGhhbmRsaW5nIGlzIGFzIGZvbGxvd3M6DQoqIE5vYm9keSB3aG8gaGFzIHJldmlld2VkIHRo ZSBibGstbXEgdGltZW91dCBoYW5kbGluZyBjb2RlIHdpdGggdGhpcyBwYXRjaA0KICBhcHBsaWVk IGhhcyByZXBvcnRlZCBhbnkgc2hvcnRjb21pbmdzIGZvciB0aGF0IGNvZGUuDQoqIEhvd2V2ZXIs IHNldmVyYWwgcGVvcGxlIGhhdmUgcmVwb3J0ZWQga2VybmVsIGNyYXNoZXMgdGhhdCBkaXNhcHBl YXIgd2hlbg0KICB0aGUgYmxrLW1xIHRpbWVvdXQgY29kZSBpcyByZXdvcmtlZC4gSSdtIHJlZmVy cmluZyB0byAibnZtZS1yZG1hIGNvcnJ1cHRzDQogIG1lbW9yeSB1cG9uIHRpbWVvdXQiDQogICho dHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9waXBlcm1haWwvbGludXgtbnZtZS8yMDE4LUZlYnJ1 YXJ5LzAxNTg0OC5odG1sKQ0KICBhbmQgYWxzbyB0byBhICJSSVA6IHNjc2lfdGltZXNfb3V0KzB4 MTciIGNyYXNoIGR1cmluZyBib290DQogIChodHRwczovL2J1Z3ppbGxhLmtlcm5lbC5vcmcvc2hv d19idWcuY2dpP2lkPTE5OTA3NykuDQoNClNvIHdlIGhhdmUgdGhlIGNob2ljZSBiZXR3ZWVuIHR3 byBhcHByb2FjaGVzOg0KKDEpIGFwcGx5IHRoZSBwYXRjaCBmcm9tIHlvdXIgcHJldmlvdXMgZS1t YWlsIGFuZCByb290LWNhdXNlIGFuZCBmaXggdGhlDQogICAgY3Jhc2hlcyByZWZlcnJlZCB0byBh Ym92ZS4NCigyKSBhcHBseSBhIHBhdGNoIHRoYXQgbWFrZXMgdGhlIGNyYXNoZXMgcmVwb3J0ZWQg YWdhaW5zdCB2NC4xNiBkaXNhcHBlYXIgYW5kDQogICAgcmVtb3ZlIHRoZSBhdG9taWMgaW5zdHJ1 Y3Rpb25zIGludHJvZHVjZWQgYnkgc3VjaCBhIHBhdGNoIGF0IGEgbGF0ZXIgdGltZS4NCg0KU2lu Y2UgY3Jhc2hlcyBoYXZlIGJlZW4gcmVwb3J0ZWQgZm9yIGtlcm5lbCB2NC4xNiBJIHRoaW5rIHdl IHNob3VsZCBmb2xsb3cNCmFwcHJvYWNoICgyKS4gVGhhdCB3aWxsIHJlbW92ZSB0aGUgdGltZSBw cmVzc3VyZSBmcm9tIHJvb3QtY2F1c2luZyBhbmQgZml4aW5nDQp0aGUgY3Jhc2hlcyByZXBvcnRl ZCBmb3IgdGhlIE5WTWVPRiBpbml0aWF0b3IgYW5kIFNDU0kgaW5pdGlhdG9yIGRyaXZlcnMuDQoN ClRoYW5rcywNCg0KQmFydC4NCg0KDQoNCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa4.hgst.iphmx.com ([216.71.154.42]:31990 "EHLO esa4.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753095AbeDKMuy (ORCPT ); Wed, 11 Apr 2018 08:50:54 -0400 From: Bart Van Assche To: "tj@kernel.org" CC: "linux-block@vger.kernel.org" , "israelr@mellanox.com" , "sagi@grimberg.me" , "hch@lst.de" , "martin@lichtvoll.de" , "stable@vger.kernel.org" , "axboe@kernel.dk" , "ming.lei@redhat.com" , "maxg@mellanox.com" Subject: Re: [PATCH v4] blk-mq: Fix race conditions in request timeout handling Date: Wed, 11 Apr 2018 12:50:51 +0000 Message-ID: References: <20180410135541.GA22340@ming.t460p> <7c4a8b019182d5a9259ef20e6462b3f6a533abed.camel@wdc.com> <20180410143007.GB22340@ming.t460p> <20180410152553.GC22340@ming.t460p> <20180410153031.GO3126663@devbig577.frc2.facebook.com> <20180410153812.GA3219@ming.t460p> <20180410154043.GP3126663@devbig577.frc2.facebook.com> <20180410213323.GC793541@devbig577.frc2.facebook.com> <20180410215456.GD793541@devbig577.frc2.facebook.com> In-Reply-To: <20180410215456.GD793541@devbig577.frc2.facebook.com> Content-Language: en-US Content-Type: text/plain; charset="utf-8" Content-ID: Content-Transfer-Encoding: base64 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: T24gVHVlLCAyMDE4LTA0LTEwIGF0IDE0OjU0IC0wNzAwLCB0akBrZXJuZWwub3JnIHdyb3RlOg0K PiBBaCwgeWVhaCwgSSB3YXMgbW92aW5nIGl0IG91dCBvZiBhZGRfdGltZXIgYnV0IGZvcmdvdCB0 byBhY3R1bGx5IGFkZA0KPiBpdCB0byB0aGUgaXNzdWUgcGF0aC4gIEZpeGVkIHBhdGNoIGJlbG93 Lg0KPiANCj4gQlRXLCBubyBtYXR0ZXIgd2hhdCB3ZSBkbyB3LyB0aGUgcmVxdWVzdCBoYW5kb3Zl ciBiZXR3ZWVuIG5vcm1hbCBhbmQNCj4gdGltZW91dCBwYXRocywgd2UnZCBuZWVkIHNvbWV0aGlu ZyBzaW1pbGFyLiAgT3RoZXJ3aXNlLCB3aGlsZSB3ZSBjYW4NCj4gcmVkdWNlIHRoZSB3aW5kb3cs IHdlIGNhbid0IGdldCByaWQgb2YgaXQuDQoNCigrTWFydGluIFN0ZWlnZXJ3YWxkKQ0KDQpIZWxs byBUZWp1biwNCg0KVGhhbmsgeW91IGZvciBoYXZpbmcgc2hhcmVkIHRoaXMgcGF0Y2guIEl0IGxv b2tzIGludGVyZXN0aW5nIHRvIG1lLiBXaGF0IEkNCmtub3cgYWJvdXQgdGhlIGJsay1tcSB0aW1l b3V0IGhhbmRsaW5nIGlzIGFzIGZvbGxvd3M6DQoqIE5vYm9keSB3aG8gaGFzIHJldmlld2VkIHRo ZSBibGstbXEgdGltZW91dCBoYW5kbGluZyBjb2RlIHdpdGggdGhpcyBwYXRjaA0KICBhcHBsaWVk IGhhcyByZXBvcnRlZCBhbnkgc2hvcnRjb21pbmdzIGZvciB0aGF0IGNvZGUuDQoqIEhvd2V2ZXIs IHNldmVyYWwgcGVvcGxlIGhhdmUgcmVwb3J0ZWQga2VybmVsIGNyYXNoZXMgdGhhdCBkaXNhcHBl YXIgd2hlbg0KICB0aGUgYmxrLW1xIHRpbWVvdXQgY29kZSBpcyByZXdvcmtlZC4gSSdtIHJlZmVy cmluZyB0byAibnZtZS1yZG1hIGNvcnJ1cHRzDQogIG1lbW9yeSB1cG9uIHRpbWVvdXQiDQogICho dHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9waXBlcm1haWwvbGludXgtbnZtZS8yMDE4LUZlYnJ1 YXJ5LzAxNTg0OC5odG1sKQ0KICBhbmQgYWxzbyB0byBhICJSSVA6IHNjc2lfdGltZXNfb3V0KzB4 MTciIGNyYXNoIGR1cmluZyBib290DQogIChodHRwczovL2J1Z3ppbGxhLmtlcm5lbC5vcmcvc2hv d19idWcuY2dpP2lkPTE5OTA3NykuDQoNClNvIHdlIGhhdmUgdGhlIGNob2ljZSBiZXR3ZWVuIHR3 byBhcHByb2FjaGVzOg0KKDEpIGFwcGx5IHRoZSBwYXRjaCBmcm9tIHlvdXIgcHJldmlvdXMgZS1t YWlsIGFuZCByb290LWNhdXNlIGFuZCBmaXggdGhlDQogICAgY3Jhc2hlcyByZWZlcnJlZCB0byBh Ym92ZS4NCigyKSBhcHBseSBhIHBhdGNoIHRoYXQgbWFrZXMgdGhlIGNyYXNoZXMgcmVwb3J0ZWQg YWdhaW5zdCB2NC4xNiBkaXNhcHBlYXIgYW5kDQogICAgcmVtb3ZlIHRoZSBhdG9taWMgaW5zdHJ1 Y3Rpb25zIGludHJvZHVjZWQgYnkgc3VjaCBhIHBhdGNoIGF0IGEgbGF0ZXIgdGltZS4NCg0KU2lu Y2UgY3Jhc2hlcyBoYXZlIGJlZW4gcmVwb3J0ZWQgZm9yIGtlcm5lbCB2NC4xNiBJIHRoaW5rIHdl IHNob3VsZCBmb2xsb3cNCmFwcHJvYWNoICgyKS4gVGhhdCB3aWxsIHJlbW92ZSB0aGUgdGltZSBw cmVzc3VyZSBmcm9tIHJvb3QtY2F1c2luZyBhbmQgZml4aW5nDQp0aGUgY3Jhc2hlcyByZXBvcnRl ZCBmb3IgdGhlIE5WTWVPRiBpbml0aWF0b3IgYW5kIFNDU0kgaW5pdGlhdG9yIGRyaXZlcnMuDQoN ClRoYW5rcywNCg0KQmFydC4NCg0KDQoNCg==