Return-Path: Received: from us-smtp-delivery-194.mimecast.com ([63.128.21.194]:25969 "EHLO us-smtp-delivery-194.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbdLCUMw (ORCPT ); Sun, 3 Dec 2017 15:12:52 -0500 From: Trond Myklebust To: "chucklever@gmail.com" CC: "Anna.Schumaker@Netapp.com" , "linux-nfs@vger.kernel.org" Subject: Re: [PATCH] SUNRPC: Fix a race in the receive code path Date: Sun, 3 Dec 2017 20:12:47 +0000 Message-ID: <1512331965.24703.5.camel@primarydata.com> References: <20171203185012.24473-1-trond.myklebust@primarydata.com> <9F7B84A7-B241-49D3-8F9D-36338669C827@gmail.com> In-Reply-To: <9F7B84A7-B241-49D3-8F9D-36338669C827@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: T24gU3VuLCAyMDE3LTEyLTAzIGF0IDEzOjU0IC0wNTAwLCBDaHVjayBMZXZlciB3cm90ZToNCj4g PiBPbiBEZWMgMywgMjAxNywgYXQgMTo1MCBQTSwgVHJvbmQgTXlrbGVidXN0IDx0cm9uZC5teWts ZWJ1c3RAcHJpbWFyDQo+ID4geWRhdGEuY29tPiB3cm90ZToNCj4gPiANCj4gPiBXZSBtdXN0IGVu c3VyZSB0aGF0IHRoZSBjYWxsIHRvIHJwY19zbGVlcF9vbigpIGluIHhwcnRfdHJhbnNtaXQoKQ0K PiA+IGNhbm5vdA0KPiA+IHJhY2Ugd2l0aCB0aGUgY2FsbCB0byB4cHJ0X2NvbXBsZXRlX3Jxc3Qo KS4NCj4gDQo+IDotKCB0aGlzIHdpbGwga2lsbCBzY2FsYWJpbGl0eSwgd2UgbWlnaHQgYXMgd2Vs bCBqdXN0IGdvIGJhY2sNCj4gdG8gdGhlIG9sZCBsb2NraW5nIHNjaGVtZS4NCg0KSXQgc2hvdWxk bid0IG1ha2UgYSBodWdlIGRpZmZlcmVuY2UsIGJ1dCBJIGFncmVlIHRoYXQgd2UgZG8gd2FudCB0 byBnZXQNCnJpZCBvZiB0aGF0IHRyYW5zcG9ydCBsb2NrLg0KDQpIb3cgYWJvdXQgdGhlIGZvbGxv d2luZywgdGhlbj8NCg0KODwtLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0NCkZyb20gNmEwYzUwN2YxNjBkNTYyNGQ5MDQ5Mjgx Y2Q5ZGZlMjIyYTg2NmYwNiBNb24gU2VwIDE3IDAwOjAwOjAwIDIwMDENCkZyb206IFRyb25kIE15 a2xlYnVzdCA8dHJvbmQubXlrbGVidXN0QHByaW1hcnlkYXRhLmNvbT4NCkRhdGU6IFN1biwgMyBE ZWMgMjAxNyAxMzozNzoyNyAtMDUwMA0KU3ViamVjdDogW1BBVENIIHYyXSBTVU5SUEM6IEZpeCBh IHJhY2UgaW4gdGhlIHJlY2VpdmUgY29kZSBwYXRoDQoNCldlIG11c3QgZW5zdXJlIHRoYXQgdGhl IGNhbGwgdG8gcnBjX3NsZWVwX29uKCkgaW4geHBydF90cmFuc21pdCgpIGNhbm5vdA0KcmFjZSB3 aXRoIHRoZSBjYWxsIHRvIHhwcnRfY29tcGxldGVfcnFzdCgpLg0KDQpSZXBvcnRlZC1ieTogQ2h1 Y2sgTGV2ZXIgPGNodWNrLmxldmVyQG9yYWNsZS5jb20+DQpMaW5rOiBodHRwczovL2J1Z3ppbGxh LmxpbnV4LW5mcy5vcmcvc2hvd19idWcuY2dpP2lkPTMxNw0KRml4ZXM6IGNlN2MyNTJhOGM3NCAo IlNVTlJQQzogQWRkIGEgc2VwYXJhdGUgc3BpbmxvY2sgdG8gcHJvdGVjdC4uIikNCkNjOiBzdGFi bGVAdmdlci5rZXJuZWwub3JnICMgNC4xNCsNClNpZ25lZC1vZmYtYnk6IFRyb25kIE15a2xlYnVz dCA8dHJvbmQubXlrbGVidXN0QHByaW1hcnlkYXRhLmNvbT4NCi0tLQ0KIG5ldC9zdW5ycGMveHBy dC5jIHwgMTggKysrKysrKysrKystLS0tLS0tDQogMSBmaWxlIGNoYW5nZWQsIDExIGluc2VydGlv bnMoKyksIDcgZGVsZXRpb25zKC0pDQoNCmRpZmYgLS1naXQgYS9uZXQvc3VucnBjL3hwcnQuYyBi L25ldC9zdW5ycGMveHBydC5jDQppbmRleCAzMzNiOWQ2OTdhZTUuLjM0ZjYxMzM4NTMxOSAxMDA2 NDQNCi0tLSBhL25ldC9zdW5ycGMveHBydC5jDQorKysgYi9uZXQvc3VucnBjL3hwcnQuYw0KQEAg LTEwMjQsNiArMTAyNCw3IEBAIHZvaWQgeHBydF90cmFuc21pdChzdHJ1Y3QgcnBjX3Rhc2sgKnRh c2spDQogCX0gZWxzZSBpZiAoIXJlcS0+cnFfYnl0ZXNfc2VudCkNCiAJCXJldHVybjsNCiANCisJ cmVxLT5ycV9jb25uZWN0X2Nvb2tpZSA9IHhwcnQtPmNvbm5lY3RfY29va2llOw0KIAlyZXEtPnJx X3h0aW1lID0ga3RpbWVfZ2V0KCk7DQogCXN0YXR1cyA9IHhwcnQtPm9wcy0+c2VuZF9yZXF1ZXN0 KHRhc2spOw0KIAl0cmFjZV94cHJ0X3RyYW5zbWl0KHhwcnQsIHJlcS0+cnFfeGlkLCBzdGF0dXMp Ow0KQEAgLTEwNDgsMTkgKzEwNDksMjIgQEAgdm9pZCB4cHJ0X3RyYW5zbWl0KHN0cnVjdCBycGNf dGFzayAqdGFzaykNCiAJeHBydC0+c3RhdC5zZW5kaW5nX3UgKz0geHBydC0+c2VuZGluZy5xbGVu Ow0KIAl4cHJ0LT5zdGF0LnBlbmRpbmdfdSArPSB4cHJ0LT5wZW5kaW5nLnFsZW47DQogDQotCS8q IERvbid0IHJhY2Ugd2l0aCBkaXNjb25uZWN0ICovDQotCWlmICgheHBydF9jb25uZWN0ZWQoeHBy dCkpDQotCQl0YXNrLT50a19zdGF0dXMgPSAtRU5PVENPTk47DQotCWVsc2Ugew0KKwlzcGluX3Vu bG9ja19iaCgmeHBydC0+dHJhbnNwb3J0X2xvY2spOw0KKw0KKwlpZiAoIVJFQURfT05DRShyZXEt PnJxX3JlcGx5X2J5dGVzX3JlY3ZkKSAmJiBycGNfcmVwbHlfZXhwZWN0ZWQodGFzaykpIHsNCisJ CXNwaW5fbG9jaygmeHBydC0+cmVjdl9sb2NrKTsNCiAJCS8qDQogCQkgKiBTbGVlcCBvbiB0aGUg cGVuZGluZyBxdWV1ZSBzaW5jZQ0KIAkJICogd2UncmUgZXhwZWN0aW5nIGEgcmVwbHkuDQogCQkg Ki8NCi0JCWlmICghcmVxLT5ycV9yZXBseV9ieXRlc19yZWN2ZCAmJiBycGNfcmVwbHlfZXhwZWN0 ZWQodGFzaykpDQorCQlpZiAoIXJlcS0+cnFfcmVwbHlfYnl0ZXNfcmVjdmQpIHsNCiAJCQlycGNf c2xlZXBfb24oJnhwcnQtPnBlbmRpbmcsIHRhc2ssIHhwcnRfdGltZXIpOw0KLQkJcmVxLT5ycV9j b25uZWN0X2Nvb2tpZSA9IHhwcnQtPmNvbm5lY3RfY29va2llOw0KKwkJCS8qIERlYWwgd2l0aCBk aXNjb25uZWN0IHJhY2VzICovDQorCQkJaWYgKCF4cHJ0X2Nvbm5lY3RlZCh4cHJ0KSkNCisJCQkJ eHBydF93YWtlX3BlbmRpbmdfdGFza3MoeHBydCwgLUVOT1RDT05OKTsNCisJCX0NCisJCXNwaW5f dW5sb2NrKCZ4cHJ0LT5yZWN2X2xvY2spOw0KIAl9DQotCXNwaW5fdW5sb2NrX2JoKCZ4cHJ0LT50 cmFuc3BvcnRfbG9jayk7DQogfQ0KIA0KIHN0YXRpYyB2b2lkIHhwcnRfYWRkX2JhY2tsb2coc3Ry dWN0IHJwY194cHJ0ICp4cHJ0LCBzdHJ1Y3QgcnBjX3Rhc2sgKnRhc2spDQotLSANCjIuMTQuMw0K DQotLSANClRyb25kIE15a2xlYnVzdA0KTGludXggTkZTIGNsaWVudCBtYWludGFpbmVyLCBQcmlt YXJ5RGF0YQ0KdHJvbmQubXlrbGVidXN0QHByaW1hcnlkYXRhLmNvbQ0K