From nobody Tue Apr 18 12:23:44 2023 X-Original-To: freebsd-fs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Q134Q2kwmz4528b for ; Tue, 18 Apr 2023 12:23:50 +0000 (UTC) (envelope-from alexander.lochmann@tu-dortmund.de) Received: from unimail.uni-dortmund.de (mx1.hrz.uni-dortmund.de [129.217.128.51]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "unimail.tu-dortmund.de", Issuer "GEANT OV RSA CA 4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Q134N5Zc5z4Y7t for ; Tue, 18 Apr 2023 12:23:48 +0000 (UTC) (envelope-from alexander.lochmann@tu-dortmund.de) Authentication-Results: mx1.freebsd.org; dkim=pass header.d=tu-dortmund.de header.s=unimail header.b=On7QblbQ; spf=pass (mx1.freebsd.org: domain of alexander.lochmann@tu-dortmund.de designates 129.217.128.51 as permitted sender) smtp.mailfrom=alexander.lochmann@tu-dortmund.de; 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FROM_EQ_ENVFROM(0.00)[]; ASN(0.00)[asn:680, ipnet:129.217.0.0/16, country:DE]; RCVD_COUNT_TWO(0.00)[2] X-Rspamd-Queue-Id: 4Q134N5Zc5z4Y7t X-Spamd-Bar: ------- X-ThisMailContainsUnwantedMimeParts: N This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --------------DJtOup0CQKKsBQoU0Miorus7 Content-Type: multipart/mixed; boundary="------------7afhr1SJezfV9o1qGNBaaeMn"; protected-headers="v1" From: Alexander Lochmann To: Kirk McKusick Cc: Konstantin Belousov , freebsd-fs@freebsd.org Message-ID: Subject: Re: Understanding locking for buf References: <202304132224.33DMONo4027229@chez.mckusick.com> In-Reply-To: <202304132224.33DMONo4027229@chez.mckusick.com> --------------7afhr1SJezfV9o1qGNBaaeMn Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: base64 VGhhbmtzLCBLaXJrLCBmb3IgeW91ciBleHBsYW5hdGlvbiENCg0KT24gMTQuMDQuMjMgMDA6 MjQsIEtpcmsgTWNLdXNpY2sgd3JvdGU6DQo+IExldCBtZSB0cnkgdG8gZ2l2ZSBhIGRpZmZl cmVudCBleHBsYW5hdGlvbiBmb3IgaG93IGJ1ZmZlciBsb2NraW5nDQo+IGlzIGhhbmRsZWQg d2hpY2ggbWF5IGhlbHAgY2xlYXIgdXAgd2hhdCBpcyBoYXBwZW5pbmcuIFdoZW4gYSBzeXN0 ZW0NCj4gY2FsbCBpbnRvIGEgZmlsZXN5c3RlbSB1c2luZyBidWZmZXJzIGxvY2tzIGEgYnVm ZmVyIGl0IGlzIHJlcXVpcmVkDQo+IHRvIHJlbGVhc2UgdGhlIGxvY2sgYmVmb3JlIGl0IHJl dHVybnMuIFdoZW4gcmVhZGluZyBhIGJsb2NrIHRoaXMNCj4gcmVxdWlyZW1lbnQgaXMgZWFz eSB0byBmdWxmaWxsIGJlY2F1c2UgdGhlIHRocmVhZCBibGNrcyBpbiB0aGUNCj4ga2VybmVs IHdoaWxlIHRoZSByZWFkIGlzIGRvbmUgdGhlbiB3YWtlcyB1cCwgY29waWVzIG91dCB0aGUg ZGF0YSwNCj4gdW5sb2NrcyB0aGUgYnVmZmVyLCBhbmQgcmV0dXJucy4NCk1pZ2h0IGl0IGJl IHBvc3NpYmxlIHRoYXQgSSBtaXhlZCB1cCB0aGUgKGFzc29jaWF0ZWQpIGJ1ZmZlciBhbmQg c3RydWN0IA0KYnVmPyBDdXJyZW50bHksIEknbSBvbmx5IGludGVyZXN0ZWQgaW4gdGhlIHN0 cnVjdCBidWYuDQoNCkxldCBtZSByZS1waHJhc2UgdG8gc2VlIGlmIEkgZ290IGl0IHJpZ2h0 Og0KIEZyb20gYSBzeXN0ZW0td2lkZSBwZXJzcGVjdGl2ZSwgYSBwYXJ0aWN1bGFyIHN0cnVj dCBidWYgKGFuZCB0aGUgYnVmZmVyIA0KaXRzZWxmKSBpcyBzZWN1cmVkIGFnYWluc3QgY29u Y3VycmVudCB1c2FnZSBieSBvdGhlciB0aHJlYWRzLg0KVGhlIGdlb20gdGhyZWFkLCBob3dl dmVyLCBjb21wbGV0ZXMgYSByZWFkIHJlcXVlc3QsIGFuZCBtb2RpZmllcyB0aGUgDQpzdHJ1 Y3QgYnVmLiBUaGUgYnVmZmVyIGl0c2VsZiBpcyBhbHNvIG1vZGlmaWVkIGJ1dCBJIGlnbm9y ZWQgdGhhdCBmb3IgYSANCm1vbWVudC4gSW4gdGhhdCBwYXJ0aWN1bGFyIHBhcnQgb2YgdGhl IGNvZGUgKGdfdmZzX2RvbmUoKSksIG5vIGxvY2sgaXMgDQpuZWVkZWQgc2luY2UgdGhlIHN0 cnVjdCBidWYgaXMgYWxyZWFkeSBnbG9iYWxseSAgbG9ja2VkLCBhbmQgbm8gb3RoZXIgDQpj b25jdXJyZW50IGFjY2Vzc2VzIGFyZSBwb3NzaWJsZS4NClRoYXQgaXMgd2hhdCBJIG1lYW50 IGJ5ICd2YWxpZCBleGNlcHRpb24nLiBGcm9tIGEgdGV4dGJvb2sgcGVyc3BlY3RpdmUsIA0K b25lIHNob3VsZCBhY3F1aXJlIGEgbG9jayBzb21ld2hhdCBiZWZvcmUgdGhlIGFjY2Vzcywg YW5kIHJlbGVhc2UgaXQgDQphZnRlcndhcmRzLiBUaGF0IGlzIHRoZSBiYXNlbGluZSBJJ20g Y29tcGFyaW5nIHRvLg0KDQoNCi0gQWxleA0KPiANCj4gSG93ZXZlciB3aGVuIGRvaW5nIGEg d3JpdGUsIHRoZSBidWZmZXIgaXMgbG9ja2VkIGFuZCB0aGUgZGF0YSBjb3BpZWQNCj4gaW50 byBpdC4gSWYgdGhlIHdyaXRlIGlzIGRlbGF5ZWQgKGJkd3JpdGUpIG9yIHN5bmNocm9ub3Vz IChid3JpdGUpDQo+IHRoZW4gdGhlIGJ1ZmZlciBpcyB1bmxvY2tlZCBhbmQgdGhlIHN5c3Rl bSBjYWxsIHJldHVybnMuIEhvd2V2ZXIgaWYNCj4gYW4gYXN5bmNocm9ub3VzIHdyaXRlIGlz IGRvbmUgKGJhd3JpdGUpIHRoZW4gdGhlbiB0aGUgc3lzdGVtIGNhbGwNCj4gd2FudHMgdG8g cmV0dXJuIGJlZm9yZSB0aGUgd3JpdGUgaGFzIG9jY3VycmVkLiBEb2luZyBzbyBob3dldmVy IHdvdWxkDQo+IHZpb2xhdGUgdGhlIHJlcXVpcmVtZW50IHRoYXQgdGhlIGJ1ZmZlciBiZSB1 bmxvY2tlZC4gQW5kIHVubG9ja2luZyB0aGUNCj4gYnVmZmVyIHdvdWxkIGFsbG93IG90aGVy IHdyaXRlcyB0byBvY2N1ciBvbiBhIGJ1ZmZlciB0aGF0IHdhcyBwb3NzaWJseQ0KPiBiZWlu ZyB3cml0dGVuIHRodXMgaGF2aW5nIGluY29uc2lzdGVudCBkYXRhIG9uIHRoZSBkaXNrLiBU aGUgc29sdXRpb24NCj4gaXMgdG8gInBhc3Mgb3duZXJzaGlwIiB0byB0aGUga2VybmVsICh1 c2luZyBLRVJOUFJPQykuIFRodXMgdGhlIHN5c3RlbQ0KPiBjYWxsIGNhbiByZXR1cm4gYXMg aXQgbm8gbG9uZ2VyIG93bnMgYW55IGxvY2tlZCBidWZmZXJzLiBJbnN0ZWFkIHRoZQ0KPiBr ZXJuZWwgdGFrZXMgcmVzcG9uc2liaWxpdHkgZm9yIHVubG9ja2luZyB0aGUgYnVmZmVyIHdo ZW4gdGhlIHdyaXRlDQo+IGhhcyBiZWVuIGNvbXBsZXRlZC4gVGh1cyB0aGUgYnVmZmVyIHVu bG9jayBpcyBkb25lIGJ5IHRoZSBrZXJuZWwgaW4NCj4gZ192ZnNfZG9uZSgpIHdoaWNoIGFs bG93cyBvdGhlciB0aHJlYWRzIHdpc2hpbmcgdG8gYWNjZXNzIHRoZSBidWZmZXINCj4gdG8g cHJvY2VlZC4NCj4gDQo+IAlLaXJrIE1jS3VzaWNrDQoNCi0tIA0KVGVjaG5pc2NoZSBVbml2 ZXJzaXTDpHQgRG9ydG11bmQNCkNvbXB1dGVyIFNjaWVuY2UgWElJIC0gU3lzdGVtIFNvZnR3 YXJlIEdyb3VwDQpBbGV4YW5kZXIgTG9jaG1hbm4gICAgICAgICAgICAgICAgUEdQIGtleTog MHhCQzNFRjZGRA0KT3R0by1IYWhuLVN0ci4gMTYgICAgICAgICAgICAgICAgIHBob25lOiAg KzQ5LjIzMS43NTU2MTQxDQpELTQ0MjI3IERvcnRtdW5kICAgICAgICAgICAgICAgICAgZmF4 OiAgICArNDkuMjMxLjc1NTYxMTYNCmh0dHBzOi8vc3lzLmNzLnR1LWRvcnRtdW5kLmRlL2Fs DQo= --------------7afhr1SJezfV9o1qGNBaaeMn-- --------------DJtOup0CQKKsBQoU0Miorus7 Content-Type: application/pgp-signature; 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