From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "hch@lst.de" , "drjones@redhat.com" , "linux-block@vger.kernel.org" , "osandov@fb.com" , "ming.lei@redhat.com" , "axboe@kernel.dk" CC: "linux-scsi@vger.kernel.org" , "martin.petersen@oracle.com" Subject: Re: [blk-mq Bug] race on removing hctx->dispatch_wait from wait queue Date: Sun, 24 Jun 2018 16:33:21 +0000 Message-ID: References: <20180624101605.GA32610@ming.t460p> In-Reply-To: <20180624101605.GA32610@ming.t460p> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gU3VuLCAyMDE4LTA2LTI0IGF0IDE4OjE2ICswODAwLCBNaW5nIExlaSB3cm90ZToNCj4gTm93 IEkgYW0gcmV2aXNpdGluZyAnVEFHX1NIQVJFRCBpbiByZXN0YXJ0JyBhZ2FpbiBmb3IgdGhlIGxv bmcgZGVsYXkgaXNzdWUNCj4gb2YgU0NTSSBMVU4gcHJvYmUuIEFuZCBmb3VuZCB0aGVyZSBpcyBv bmUgYnVnIGluIGJsa19tcV9tYXJrX3RhZ193YWl0KCk6DQo+IA0KPiAtIGhjdHgtPmRpc3BhdGNo X3dhaXQgaXMgYWRkZWQgdG8gd2FpdCBxdWV1ZSBieSBob2xkaW5nIGhjdHgtPmxvY2sgYW5kDQo+ IHRoZSB3YWl0IHF1ZXVlJ3MgbG9jaw0KPiANCj4gLSBubyBoY3R4LT5sb2NrIGlzIGhlbGQgd2hl biByZW1vdmluZyBoY3R4LT5kaXNwYXRjaF93YWl0IGZyb20gd2FpdA0KPiAgIHF1ZXVlLg0KPiAN Cj4gLSBzbyB0aGUgdHdvIGFjdGlvbnMoYWRkLCByZW1vdmUpIG1heSBoYXBwZW4gbWVhbnRpbWUg c2luY2UNCj4gICBoY3R4LT5kaXNwYXRjaF93YWl0IGNhbiBiZSBhZGRlZCB0byBkaWZmZXJlbnQg d2FpdCBxdWV1ZXMuDQo+IA0KPiBUdXJucyBvdXQgdGhpcyBpc3N1ZSBjYW4gYmUgb2JzZXJ2ZWQg ZWFzaWx5IGJ5IGFwcGx5aW5nIHRoZSBwYXRjaGVzWzJdLA0KPiB3aGljaCBpcyBmb3IgcmVtb3Zp bmcgJ1RBR19TSEFSRUQgaW4gcmVzdGFydCcsIHRoZW4gcnVuIHNpbXBsZSBzaGFyZWQtdGFnDQo+ IG51bGxfYmxrIHRlc3RbNF0uDQo+IA0KPiBCdXQgaWYgdGhlIGhjdHgtPmxvY2sgaXMgaGVsZCBp biBibGtfbXFfZGlzcGF0Y2hfd2FrZSgpLCBhcyBkb25lIGluDQo+IHBhdGNoIFszXSwgdGhlcmUg aXNuJ3Qgc3VjaCBpc3N1ZSBhdCBhbGwsIHNvIGl0IHNob3dzIHRoaXMgaXNzdWUgaXMNCj4gcmVs YXRlZCB3aXRoIGhjdHgtPmxvY2ssIGFuZCBhZGRpbmcvcmVtb3ZpbmcgaGN0eC0+ZGlzcGF0Y2hf d2FpdCB0bw0KPiB3YWl0IHF1ZXVlLiBCdXQgdGhlIHdheSBvZiBob2xkaW5nIGhjdHgtPmxvY2sg aW4gaXJxIGNvbnRleHQgbWF5IG5vdA0KPiBiZSBvbmUgYWNjZXB0ZWQgc29sdXRpb24sIHNpbmNl IGl0IGhhcyBiZWVuIGF2b2lkZWQgZnJvbSB0aGUgYmVnaW5uaW5nDQo+IG9mIGJsay1tcS4NCj4g DQo+IFNvIGRvZXMgYW55b25lIGhhdmUgYmV0dGVyIGlkZWFzIGZvciB0aGlzIGlzc3VlPw0KPiAN Cj4gU28gZmFyLCBmb2xsb3dzIHdoYXQgSSB0aG91Z2h0IG9mOg0KPiANCj4gMSkgZml4IHRoZSBt ZWNoYW5pc20gb2YgYmxrX21xX21hcmtfdGFnX3dhaXQoKSwgYW5kIHJlbW92aW5nDQo+ICdUQUdf U0hBUkVEIGluIHJlc3RhcnQnLCB0aGVuIHdlIGNhbiBmaXggdGhlIGxvbmcgZGVsYXkgaXNzdWUg b2YNCj4gU0NTSSBMVU4gcHJvYmUsIG1lYW50aW1lIHBlcmZvcm1hbmNlIGNhbiBnb3QgaW1wcm92 ZWQsIGFzIEkgb2JzZXJ2ZWQsDQo+IHRoaXMgd2F5IG1heSBpbXByb3ZlIElPUFMgYnkgMjB+MzAl IGluIG11bHRpLUxVTiBzY3NpX2RlYnVnIHRlc3QuDQo+IEJ1dCB0aGUgaXNzdWUgaXMgaG93IHRv IGZpeD8NCj4gDQo+IDIpIGtlZXAgJ1RBR19TSEFSRUQgaW4gcmVzdGFydCcgYW5kIGxldCBpdCBj b3ZlciB0aGUgaXNzdWUgb2YNCj4gYmxrX21xX21hcmtfdGFnX3dhaXQoKSBhcyBub3csIHRoZW4g dHJ5IHRvIGltcHJvdmUgJ1RBR19TSEFSRUQgaW4gcmVzdGFydCcNCj4gaW4gYW5vdGhlciB3YXks IHNvIHRoYXQgcGVyZm9ybWFuY2UgY2FuIGJlIGJldHRlciwgYW5kIHN5bmNocm9uaXplX3JjdSgp DQo+IGNhbiBiZSByZW1vdmVkIGZyb20gYmxrX21xX2RlbF9xdWV1ZV90YWdfc2V0KCksIHRoZW4g U0NTSSBMVU4gcHJvYmUgbG9uZw0KPiBkZWxheSBjYW4gYmUgZml4ZWQuIEkgaGFkIHdyb3RlIHBh dGNoZXMgdG8gZG8gdGhhdCBsYXN0IHllYXIuIElmIGFueW9uZQ0KPiBpcyBpbnRlcmVzdGVkLCBJ IG1heSBwb3N0IGl0IG91dC4NCj4gDQo+IE9yIG90aGVyIGlkZWFzLCBhbnkgY29tbWVudHMgJiBp ZGVhcyBhcmUgd2VsY29tZSENCg0KUGxlYXNlIGhhdmUgYSBsb29rIGF0IFtQQVRDSF0gYmxrLW1x OiBGaXggYSByYWNlIGNvbmRpdGlvbiBpbiBibGtfbXFfbWFya190YWdfd2FpdCgpLA0KMTYgSmFu IDIwMTggKGh0dHBzOi8vd3d3Lm1haWwtYXJjaGl2ZS5jb20vbGludXgtYmxvY2tAdmdlci5rZXJu ZWwub3JnL21zZzE3NDc0Lmh0bWwpLg0KDQpUaGFua3MsDQoNCkJhcnQuDQoNCg0KDQoNCg==