From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa4.hgst.iphmx.com ([216.71.154.42]:3725 "EHLO esa4.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752632AbdHQUmA (ORCPT ); Thu, 17 Aug 2017 16:42:00 -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: Thu, 17 Aug 2017 20:41:10 +0000 Message-ID: <1503002469.2615.13.camel@wdc.com> References: <1502916040-18067-1-git-send-email-longman@redhat.com> <20170817093444.3276f7ab@gandalf.local.home> <20170817163056.19ea42c8@gandalf.local.home> In-Reply-To: <20170817163056.19ea42c8@gandalf.local.home> Content-Language: en-US Content-Type: text/plain; charset="utf-8" Content-ID: Content-Transfer-Encoding: base64 MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: T24gVGh1LCAyMDE3LTA4LTE3IGF0IDE2OjMwIC0wNDAwLCBTdGV2ZW4gUm9zdGVkdCB3cm90ZToN Cj4gT24gVGh1LCAxNyBBdWcgMjAxNyAxMjoyNDozOSAtMDQwMA0KPiBXYWltYW4gTG9uZyA8bG9u Z21hbkByZWRoYXQuY29tPiB3cm90ZToNCj4gDQo+ID4gT24gMDgvMTcvMjAxNyAwOTozNCBBTSwg U3RldmVuIFJvc3RlZHQgd3JvdGU6DQo+ID4gPiBPbiBXZWQsIDE2IEF1ZyAyMDE3IDE2OjQwOjQw IC0wNDAwDQo+ID4gPiBXYWltYW4gTG9uZyA8bG9uZ21hbkByZWRoYXQuY29tPiB3cm90ZToNCj4g PiA+ICANCj4gPiA+ID4gVGhlIGxvY2tkZXAgY29kZSBoYWQgcmVwb3J0ZWQgdGhlIGZvbGxvd2lu ZyB1bnNhZmUgbG9ja2luZyBzY2VuYXJpbzoNCj4gPiA+ID4gDQo+ID4gPiA+ICAgICAgICBDUFUw ICAgICAgICAgICAgICAgICAgICBDUFUxDQo+ID4gPiA+ICAgICAgICAtLS0tICAgICAgICAgICAg ICAgICAgICAtLS0tDQo+ID4gPiA+ICAgbG9jayhzX2FjdGl2ZSMyMjgpOw0KPiA+ID4gPiAgICAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgbG9jaygmYmRldi0+YmRfbXV0ZXgvMSk7DQo+ID4g PiA+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICBsb2NrKHNfYWN0aXZlIzIyOCk7DQo+ ID4gPiA+ICAgbG9jaygmYmRldi0+YmRfbXV0ZXgpOyAgDQo+ID4gPiANCj4gPiA+IENhbiB5b3Ug c2hvdyB0aGUgZXhhY3QgbG9jYXRpb25zIG9mIHRoZXNlIGxvY2tzLiBJIGhhdmUgbm8gaWRlYSB3 aGVyZQ0KPiA+ID4gdGhpcyAic19hY3RpdmUiIGlzLiAgDQo+ID4gDQo+ID4gVGhlIHNfYWN0aXZl IGlzbid0IGFuIGFjdHVhbCBsb2NrLiBJdCBpcyBhIHJlZmVyZW5jZSBjb3VudCAoa24tPmNvdW50 KQ0KPiA+IG9uIHRoZSBzeXNmcyAoa2VybmZzKSBmaWxlLiBSZW1vdmFsIG9mIGEgc3lzZnMgZmls ZSwgaG93ZXZlciwgcmVxdWlyZQ0KPiA+IGEgd2FpdCB1bnRpbCBhbGwgdGhlIHJlZmVyZW5jZXMg YXJlIGdvbmUuIFRoZSByZWZlcmVuY2UgY291bnQgaXMNCj4gPiB0cmVhdGVkIGxpa2UgYSByd3Nl bSB1c2luZyBsb2NrZGVwIGluc3RydW1lbnRhdGlvbiBjb2RlLg0KPiANCj4gV2hpY2gga2VybmVs IGlzIHRoaXM/IEkgZG9uJ3Qgc2VlIGFueSBsb2NrZGVwIGFubm90YXRpb24gYXJvdW5kDQo+IGtu LT5jb3VudCAoZG9pbmcgYSBnaXQgZ3JlcCwgSSBmaW5kIGl0IHJlZmVyZW5jZWQgaW4gZnMva2Vy bmZzL2Rpci5jKQ0KDQpBcyBmYXIgYXMgSSBrbm93IHRoZSBzX2FjdGl2ZSBsb2NrZGVwIGFubm90 YXRpb25zIHdlcmUgaW50cm9kdWNlZCBpbiAyMDA3DQp0aHJvdWdoIGNvbW1pdCAwYWI2NjA4OGM4 NTUgKCJzeXNmczogaW1wbGVtZW50IHN5c2ZzX2RpcmVudCBhY3RpdmUgcmVmZXJlbmNlDQphbmQg aW1tZWRpYXRlIGRpc2Nvbm5lY3QiKS4gVG9kYXkgdGhlc2UgYW5ub3RhdGlvbnMgZXhpc3QgaW4g a2VybmZzOg0KJCBnaXQgZ3JlcCAtbkh3IGRlcF9tYXAgZnMva2VybmZzDQpmcy9rZXJuZnMvZGly LmM6NDIxOgkJcndzZW1fYWNxdWlyZV9yZWFkKCZrbi0+ZGVwX21hcCwgMCwgMSwgX1JFVF9JUF8p Ow0KZnMva2VybmZzL2Rpci5jOjQ0MToJCXJ3c2VtX3JlbGVhc2UoJmtuLT5kZXBfbWFwLCAxLCBf UkVUX0lQXyk7DQpmcy9rZXJuZnMvZGlyLmM6NDY4OgkJcndzZW1fYWNxdWlyZSgma24tPmRlcF9t YXAsIDAsIDAsIF9SRVRfSVBfKTsNCmZzL2tlcm5mcy9kaXIuYzo0NzA6CQkJbG9ja19jb250ZW5k ZWQoJmtuLT5kZXBfbWFwLCBfUkVUX0lQXyk7DQpmcy9rZXJuZnMvZGlyLmM6NDc4OgkJbG9ja19h Y3F1aXJlZCgma24tPmRlcF9tYXAsIF9SRVRfSVBfKTsNCmZzL2tlcm5mcy9kaXIuYzo0Nzk6CQly d3NlbV9yZWxlYXNlKCZrbi0+ZGVwX21hcCwgMSwgX1JFVF9JUF8pOw0KZnMva2VybmZzL2Rpci5j OjEzODU6CQlyd3NlbV9hY3F1aXJlKCZrbi0+ZGVwX21hcCwgMCwgMSwgX1JFVF9JUF8pOw0KZnMv a2VybmZzL2ZpbGUuYzoxMDAwOgkJbG9ja2RlcF9pbml0X21hcCgma24tPmRlcF9tYXAsICJzX2Fj dGl2ZSIsIGtleSwgMCk7DQoNCkJhcnQu