From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.hgst.iphmx.com ([68.232.143.124]:9892 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbdHRQWg (ORCPT ); Fri, 18 Aug 2017 12:22:36 -0400 From: Bart Van Assche To: "longman@redhat.com" , "rostedt@goodmis.org" CC: "bfields@fieldses.org" , "mingo@kernel.org" , "jlayton@poochiereds.net" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "axboe@kernel.dk" , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH v2] blktrace: Fix potentail deadlock between delete & sysfs ops Date: Fri, 18 Aug 2017 16:21:46 +0000 Message-ID: <1503073304.2622.5.camel@wdc.com> References: <1502916040-18067-1-git-send-email-longman@redhat.com> <20170817093444.3276f7ab@gandalf.local.home> <20170817171007.1ab33b8f@gandalf.local.home> <20170817173004.263d2891@gandalf.local.home> <5a5d0743-d2db-89c8-59cc-542835baeccf@redhat.com> In-Reply-To: <5a5d0743-d2db-89c8-59cc-542835baeccf@redhat.com> Content-Language: en-US Content-Type: text/plain; charset="utf-8" Content-ID: <294544477A4E8B4DAC47AF44D42F4FCC@namprd04.prod.outlook.com> Content-Transfer-Encoding: base64 MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: T24gRnJpLCAyMDE3LTA4LTE4IGF0IDA5OjU1IC0wNDAwLCBXYWltYW4gTG9uZyB3cm90ZToNCj4g T24gMDgvMTcvMjAxNyAwNTozMCBQTSwgU3RldmVuIFJvc3RlZHQgd3JvdGU6DQo+ID4gT24gVGh1 LCAxNyBBdWcgMjAxNyAxNzoxMDowNyAtMDQwMA0KPiA+IFN0ZXZlbiBSb3N0ZWR0IDxyb3N0ZWR0 QGdvb2RtaXMub3JnPiB3cm90ZToNCj4gPiA+IEluc3RlYWQgb2YgcGxheWluZyBnYW1lcyB3aXRo IHRha2luZyB0aGUgbG9jaywgdGhlIG9ubHkgd2F5IHRoaXMgcmFjZQ0KPiA+ID4gaXMgaGl0LCBp cyBpZiB0aGUgcGFydGl0aW9uIGlzIGJlaW5nIGRlbGV0ZWQgYW5kIHRoZSBzeXNmcyBhdHRyaWJ1 dGUgaXMNCj4gPiA+IGJlaW5nIHJlYWQgYXQgdGhlIHNhbWUgdGltZSwgY29ycmVjdD8gSW4gdGhh dCBjYXNlLCBqdXN0IHJldHVybg0KPiA+ID4gLUVOT0RFViwgYW5kIGJlIGRvbmUgd2l0aCBpdC4N Cj4gPiANCj4gPiBOZXZlcm1pbmQgdGhhdCB3b250IHdvcmsuIFRvbyBiYWQgdGhlcmUncyBub3Qg YSBtdXRleF9sb2NrX3RpbWVvdXQoKQ0KPiA+IHRoYXQgd2UgY291bGQgdXNlIGluIGEgbG9vcC4g SXQgd291bGQgc29sdmUgdGhlIGlzc3VlIG9mIGZvcndhcmQNCj4gPiBwcm9ncmVzcyB3aXRoIFJU IHRhc2tzLCBhbmQgd2lsbCBicmVhayBhZnRlciBhIHRpbWVvdXQgaW4gY2FzZSBvZg0KPiA+IGRl YWRsb2NrLg0KPiANCj4gSSB0aGluayBpdCB3aWxsIGJlIHVzZWZ1bCB0byBoYXZlIG11dGV4X3Rp bWVkX2xvY2soKS4gUlQtbXV0ZXggZG9lcyBoYXZlDQo+IGEgdGltZWQgdmVyc2lvbiwgc28gSSBn dWVzcyBpdCBzaG91bGRuJ3QgYmUgaGFyZCB0byBpbXBsZW1lbnQgb25lIGZvcg0KPiBtdXRleC4g SSBjYW4gdGFrZSBhIHNob3QgYXQgdHJ5aW5nIHRvIGRvIHRoYXQuDQoNCihqdXN0IGNhdWdodCB1 cCB3aXRoIHRoZSBlbnRpcmUgZS1tYWlsIHRocmVhZCkNCg0KU29ycnkgV2FpbWFuIGJ1dCBwZXJz b25hbGx5IEkgdGhvcm91Z2hseSBkZXRlc3QgbG9vcHMgYXJvdW5kIG11dGV4X3RyeWxvY2soKSBv cg0KbXV0ZXhfdGltZWRfbG9jaygpIGJlY2F1c2Ugc3VjaCBsb29wcyBhcmUgdXN1YWxseSB1c2Vk IHRvIHBhcGVyIG92ZXIgYSBwcm9ibGVtDQppbnN0ZWFkIG9mIGZpeGluZyB0aGUgcm9vdCBjYXVz ZS4gV2hhdCBJIHVuZGVyc3Rvb2QgZnJvbSB0aGUgY29tbWVudCBpbiB2MSBvZiB5b3VyDQpwYXRj aCBpcyB0aGF0IGJkX211dGV4IGlzIG5vdCBvbmx5IGhlbGQgZHVyaW5nIGJsb2NrIGRldmljZSBj cmVhdGlvbiBhbmQgcmVtb3ZhbA0KYnV0IGFkZGl0aW9uYWxseSB0aGF0IGJkX211dGV4IGlzIG9i dGFpbmVkIGluc2lkZSBzeXNmcyBhdHRyaWJ1dGUgY2FsbGJhY2sgbWV0aG9kcz8NClRoYXQgcGF0 dGVybiBpcyBndWFyYW50ZWVkIHRvIGxlYWQgdG8gZGVhZGxvY2tzLiBTaW5jZSB0aGUgYmxvY2sg ZGV2aWNlIHJlbW92YWwNCmNvZGUgd2FpdHMgdW50aWwgYWxsIHN5c2ZzIGNhbGxiYWNrIG1ldGhv ZHMgaGF2ZSBmaW5pc2hlZCB0aGVyZSBpcyBubyBuZWVkIHRvDQpwcm90ZWN0IGFnYWluc3QgYmxv Y2sgZGV2aWNlIHJlbW92YWwgaW5zaWRlIHRoZSBzeXNmcyBjYWxsYmFjayBtZXRob2RzLiBNeSBw cm9wb3NhbA0KaXMgdG8gc3BsaXQgYmRfbXV0ZXg6IG9uZSBnbG9iYWwgbXV0ZXggdGhhdCBzZXJp YWxpemVzIGJsb2NrIGRldmljZSBjcmVhdGlvbiBhbmQNCnJlbW92YWwgYW5kIG9uZSBtdXRleCBw ZXIgYmxvY2sgZGV2aWNlIHRoYXQgc2VyaWFsaXplcyBjaGFuZ2VzIHRvIGEgc2luZ2xlIGJsb2Nr DQpkZXZpY2UuIE9idGFpbmluZyB0aGUgZ2xvYmFsIG11dGV4IGZyb20gaW5zaWRlIGEgYmxvY2sg ZGV2aWNlIHN5c2ZzIGNhbGxiYWNrDQpmdW5jdGlvbiBpcyBub3Qgc2FmZSBidXQgb2J0YWluaW5n IHRoZSBwZXItYmxvY2stZGV2aWNlIG11dGV4IGZyb20gaW5zaWRlIGEgc3lzZnMNCmNhbGxiYWNr IGZ1bmN0aW9uIGlzIHNhZmUuDQoNCkJhcnQu