From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail104.syd.optusnet.com.au (mail104.syd.optusnet.com.au [211.29.132.246]) by ml01.01.org (Postfix) with ESMTP id DD76020216B84 for ; Mon, 19 Aug 2019 02:26:51 -0700 (PDT) Date: Mon, 19 Aug 2019 19:24:09 +1000 From: Dave Chinner Subject: Re: [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ; -) Message-ID: <20190819092409.GM7777@dread.disaster.area> References: <20190809225833.6657-1-ira.weiny@intel.com> <20190814101714.GA26273@quack2.suse.cz> <20190814180848.GB31490@iweiny-DESK2.sc.intel.com> <20190815130558.GF14313@quack2.suse.cz> <20190816190528.GB371@iweiny-DESK2.sc.intel.com> <20190817022603.GW6129@dread.disaster.area> <20190819063412.GA20455@quack2.suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190819063412.GA20455@quack2.suse.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Jan Kara Cc: Michal Hocko , Theodore Ts'o , linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, John Hubbard , linux-kernel@vger.kernel.org, Matthew Wilcox , linux-xfs@vger.kernel.org, Jason Gunthorpe , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Andrew Morton , linux-ext4@vger.kernel.org List-ID: T24gTW9uLCBBdWcgMTksIDIwMTkgYXQgMDg6MzQ6MTJBTSArMDIwMCwgSmFuIEthcmEgd3JvdGU6 Cj4gT24gU2F0IDE3LTA4LTE5IDEyOjI2OjAzLCBEYXZlIENoaW5uZXIgd3JvdGU6Cj4gPiBPbiBG cmksIEF1ZyAxNiwgMjAxOSBhdCAxMjowNToyOFBNIC0wNzAwLCBJcmEgV2Vpbnkgd3JvdGU6Cj4g PiA+IE9uIFRodSwgQXVnIDE1LCAyMDE5IGF0IDAzOjA1OjU4UE0gKzAyMDAsIEphbiBLYXJhIHdy b3RlOgo+ID4gPiA+IE9uIFdlZCAxNC0wOC0xOSAxMTowODo0OSwgSXJhIFdlaW55IHdyb3RlOgo+ ID4gPiA+ID4gT24gV2VkLCBBdWcgMTQsIDIwMTkgYXQgMTI6MTc6MTRQTSArMDIwMCwgSmFuIEth cmEgd3JvdGU6Cj4gPiA+IDIpIFNlY29uZCByZWFzb24gaXMgdGhhdCBJIHRob3VnaHQgSSBkaWQg bm90IGhhdmUgYSBnb29kIHdheSB0byB0ZWxsIGlmIHRoZQo+ID4gPiAgICBsZWFzZSB3YXMgYWN0 dWFsbHkgaW4gdXNlLiAgV2hhdCBJIG1lYW4gaXMgdGhhdCBsZXR0aW5nIHRoZSBsZWFzZSBnbyBz aG91bGQKPiA+ID4gICAgYmUgb2sgSUZGIHdlIGRvbid0IGhhdmUgYW55IHBpbnMuLi4gIEkgd2Fz IHRoaW5raW5nIHRoYXQgd2l0aG91dCBKb2huJ3MgY29kZQo+ID4gPiAgICB3ZSBkb24ndCBoYXZl IGEgd2F5IHRvIGtub3cgaWYgdGhlcmUgYXJlIGFueSBwaW5zLi4uICBCdXQgdGhhdCBpcyB3cm9u Zy4uLgo+ID4gPiAgICBBbGwgd2UgaGF2ZSB0byBkbyBpcyBjaGVjawo+ID4gPiAKPiA+ID4gCSFs aXN0X2VtcHR5KGZpbGUtPmZpbGVfcGlucykKPiA+ID4gCj4gPiA+IFNvIG5vdyB3aXRoIHRoaXMg ZGV0YWlsIEkgdGhpbmsgeW91IGFyZSByaWdodCwgd2Ugc2hvdWxkIGJlIGFibGUgdG8gaG9sZCB0 aGUKPiA+ID4gbGVhc2UgdGhyb3VnaCB0aGUgc3RydWN0IGZpbGUgZXZlbiBpZiB0aGUgcHJvY2Vz cyBubyBsb25nZXIgaGFzIGFueQo+ID4gPiAicmVmZXJlbmNlcyIgdG8gaXQgKGllIGNsb3NlcyBh bmQgbXVubWFwcyB0aGUgZmlsZSkuCj4gPiAKPiA+IEkgcmVhbGx5LCByZWFsbHkgZGlzbGlrZSB0 aGUgaWRlYSBvZiB6b21iaWUgbGF5b3V0IGxlYXNlcy4gSXQncyBhCj4gPiBuYXN0eSBoYWNrIGZv ciBwb29yIGFwcGxpY2F0aW9uIGJlaGF2aW91ci4gVGhpcyBpcyBhICJ3ZSBhbGxvdyB1c2UKPiA+ IGFmdGVyIGxheW91dCBsZWFzZSByZWxlYXNlIiBBUEksIGFuZCBJIHRoaW5rIGVuY29kaW5nIGxh cmdlbHkKPiA+IHVudHJhY2VhYmxlIHpvbWJpZSBvYmplY3RzIGludG8gYW4gQVBJIGlzIHZlcnkg cG9vciBkZXNpZ24uCj4gPiAKPiA+IEZyb20gdGhlIGZjbnRsIG1hbiBwYWdlOgo+ID4gCj4gPiBM RUFTRVMKPiA+IAlMZWFzZXMgYXJlIGFzc29jaWF0ZWQgd2l0aCBhbiBvcGVuIGZpbGUgZGVzY3Jp cHRpb24gKHNlZQo+ID4gCW9wZW4oMikpLiAgVGhpcyBtZWFucyB0aGF0IGR1cGxpY2F0ZSBmaWxl IGRlc2NyaXB0b3JzCj4gPiAJKGNyZWF0ZWQgYnksIGZvciBleGFtcGxlLCBmb3JrKDIpIG9yIGR1 cCgyKSkgIHJl4oCQIGZlciAgdG8KPiA+IAl0aGUgIHNhbWUgIGxlYXNlLCAgYW5kIHRoaXMgbGVh c2UgbWF5IGJlIG1vZGlmaWVkIG9yCj4gPiAJcmVsZWFzZWQgdXNpbmcgYW55IG9mIHRoZXNlIGRl c2NyaXB0b3JzLiAgRnVydGhlcm1vcmUsIHRoZQo+ID4gCWxlYXNlIGlzIHJlbGVhc2VkIGJ5IGVp dGhlciBhbiBleHBsaWNpdCBGX1VOTENLIG9wZXJhdGlvbiBvbgo+ID4gCWFueSBvZiB0aGVzZSBk dXBsaWNhdGUgZmlsZSBkZXNjcmlwdG9ycywgb3Igd2hlbiBhbGwgc3VjaAo+ID4gCWZpbGUgZGVz Y3JpcHRvcnMgaGF2ZSBiZWVuIGNsb3NlZC4KPiA+IAo+ID4gTGVhc2VzIGFyZSBhc3NvY2lhdGVk IHdpdGggKm9wZW4qIGZpbGUgZGVzY3JpcHRvcnMsIG5vdCB0aGUKPiA+IGxpZmV0aW1lIG9mIHRo ZSBzdHJ1Y3QgZmlsZSBpbiB0aGUga2VybmVsLiBJZiB0aGUgYXBwbGljYXRpb24gY2xvc2VzCj4g PiB0aGUgb3BlbiBmZHMgdGhhdCByZWZlciB0byB0aGUgbGVhc2UsIHRoZW4gdGhlIGtlcm5lbCBk b2VzIG5vdAo+ID4gZ3VhcmFudGVlLCBhbmQgdGhlIGFwcGxpY2F0aW9uIGhhcyBubyByaWdodCB0 byBleHBlY3QsIHRoYXQgdGhlCj4gPiBsZWFzZSByZW1haW5zIGFjdGl2ZSBpbiBhbnkgd2F5IG9u Y2UgdGhlIGFwcGxpY2F0aW9uIGNsb3NlcyBhbGwKPiA+IGRpcmVjdCByZWZlcmVuY2VzIHRvIHRo ZSBsZWFzZS4KPiA+IAo+ID4gSU9XcywgYXBwbGljYXRpb25zIHVzaW5nIGxheW91dCBsZWFzZXMg bmVlZCB0byBob2xkIHRoZSBsZWFzZSBmZAo+ID4gb3BlbiBmb3IgYXMgbG9uZyBhcyB0aGUgd2Fu dCBhY2Nlc3MgdG8gdGhlIHBoeXNpY2FsIGZpbGUgbGF5b3V0LiBJdAo+ID4gaXMgYSBhbHNvIGEg cmVxdWlyZW1lbnQgb2YgdGhlIGxheW91dCBsZWFzZSB0aGF0IHRoZSBob2xkZXIgcmVsZWFzZXMK PiA+IHRoZSByZXNvdXJjZXMgaXQgaG9sZHMgb24gdGhlIGxheW91dCBiZWZvcmUgaXQgcmVsZWFz ZXMgdGhlIGxheW91dAo+ID4gbGVhc2UsIGV4Y2x1c2l2ZSBsZWFzZSBvciBub3QuIENsb3Npbmcg dGhlIGZkIGluZGljYXRlcyB0aGV5IGRvIG5vdAo+ID4gbmVlZCBhY2Nlc3MgdG8gdGhlIGZpbGUg YW55IG1vcmUsIGFuZCBzbyB0aGUgbGVhc2Ugc2hvdWxkIGJlCj4gPiByZWNsYWltZWQgYXQgdGhh dCBwb2ludC4KPiA+IAo+ID4gSSdtIG9mIGEgbWluZCB0byBtYWtlIHRoZSBsYXN0IGNsb3NlKCkg b24gYSBmaWxlIGJsb2NrIGlmIHRoZXJlJ3MgYW4KPiA+IGFjdGl2ZSBsYXlvdXQgbGVhc2UgdG8g cHJldmVudCBwcm9jZXNzZXMgZnJvbSB6b21iaWUtaW5nIGxheW91dAo+ID4gbGVhc2VzIGxpa2Ug dGhpcy4gaS5lLiB5b3UgY2FuJ3QgY2xvc2UgdGhlIGZkIHVudGlsIHJlc291cmNlcyB0aGF0Cj4g PiBwaW4gdGhlIGxlYXNlIGhhdmUgYmVlbiByZWxlYXNlZC4KPiAKPiBZZWFoLCBzbyB0aGlzIHdh cyBteSBpbml0aWFsIHRob3VnaCBhcyB3ZWxsIFsxXS4gQnV0IGFzIHRoZSBkaXNjdXNzaW9uIGlu Cj4gdGhhdCB0aHJlYWQgcmV2ZWFsZWQsIHRoZSBwcm9ibGVtIHdpdGggYmxvY2tpbmcgbGFzdCBj bG9zZSBpcyB0aGF0IGtlcm5lbAo+IGRvZXMgbm90IHJlYWxseSBleHBlY3QgY2xvc2UgdG8gYmxv Y2suIFlvdSBjb3VsZCBlYXNpbHkgZGVhZGxvY2sgZS5nLiBpZgo+IHRoZSBwcm9jZXNzIGdldHMg U0lHS0lMTCwgZmlsZSB3aXRoIGxlYXNlIGhhcyBmZCAxMCwgYW5kIHRoZSBSRE1BIGNvbnRleHQK PiBob2xkaW5nIHBhZ2VzIHBpbm5lZCBoYXMgZmQgMTUuCgpTdXJlLCBJIGRpZCB0aGluayBhYm91 dCB0aGlzIGEgYml0IGFib3V0IGl0IGJlZm9yZSBzdWdnZXN0aW5nIGl0IDopCgpUaGUgbGFzdCBj bG9zZSBpcyBhbiBpbnRlcmVzdGluZyBjYXNlIGJlY2F1c2UgdGhlIF9fZnB1dCgpIGNhbGwKYWN0 dWFsbHkgcnVucyBmcm9tIHRhc2tfd29yaygpIGNvbnRleHQsIG5vdCB3aGVyZSB0aGUgbGFzdCBy ZWZlcmVuY2UKaXMgYWN0dWFsbHkgZHJvcHBlZC4gU28gaXQgYWxyZWFkeSBoYXMgY2VydGFpbiBz cGVjaWZpYyBpbnRlcmFjdGlvbnMKd2l0aCBzaWduYWxzIGFuZCB0YXNrIGV4aXQgcHJvY2Vzc2lu ZyB2aWEgdGFza19hZGRfd29yaygpIGFuZAp0YXNrX3dvcmtfcnVuKCkuCgp0YXNrX2FkZF93b3Jr KCkgY2FsbHMgc2V0X25vdGlmeV9yZXN1bWUodGFzayksIHNvIGlmIG5vdGhpbmcgZWxzZQp0cmln Z2VycyB3aGVuIHJldHVybmluZyB0byB1c2Vyc3BhY2Ugd2UgcnVuIHRoaXMgcGF0aDoKCmV4aXRf dG9fdXNlcm1vZGVfbG9vcCgpCiAgdHJhY2Vob29rX25vdGlmeV9yZXN1bWUoKQogICAgdGFza193 b3JrX3J1bigpCiAgICAgIF9fZnB1dCgpCglsb2Nrc19yZW1vdmVfZmlsZSgpCgkgIGxvY2tzX3Jl bW92ZV9sZWFzZSgpCgkgICAgLi4uLgoKSXQncyB3b3J0aCBub3RpbmcgdGhhdCBsb2Nrc19yZW1v dmVfbGVhc2UoKSBkb2VzIGEKcGVyY3B1X2Rvd25fcmVhZCgpIHdoaWNoIG1lYW5zIHdlIGNhbiBh bHJlYWR5IGJsb2NrIGluIHRoaXMgY29udGV4dApyZW1vdmluZyBsZWFzZXMuLi4uCgpJZiB0aGVy ZSBpcyBhIHNpZ25hbCBwZW5kaW5nLCB0aGUgdGFzayB3b3JrIGlzIHJ1biB0aGlzIHdheSAoYmVm b3JlCnRoZSBhYm92ZSBub3RpZnkgcGF0aCk6CgpleGl0X3RvX3VzZXJtb2RlX2xvb3AoKQogIGRv X3NpZ25hbCgpCiAgICBnZXRfc2lnbmFsKCkKICAgICAgdGFza193b3JrX3J1bigpCiAgICAgICAg X19mcHV0KCkKCldlIGNhbiBkZXRlY3QgdGhpcyBjYXNlIHZpYSBzaWduYWxfcGVuZGluZygpIGFu ZCBldmVuIFNJR0tJTEwgdmlhCmZhdGFsX3NpZ25hbF9wZW5kaW5nKCksIGFuZCBzbyB3ZSBjYW4g ZGVjaWRlIG5vdCB0byBibG9jayBiYXNlZCBvbgp0aGUgZmFjdCB0aGUgcHJvY2VzcyBpcyBhYm91 dCB0byBiZSByZWFwZWQgYW5kIHNvIHRoZSBsZWFzZSBsYXJnZWx5CmRvZXNuJ3QgbWF0dGVyIGFu eW1vcmUuIEknZCBhcmd1ZSB0aGF0IGl0IGlzIGNsb3NlIGFuZCB3ZSBjYW4ndAplYXNpbHkgYmFj ayBvdXQsIHNvIHdlJ2Qgb25seSBicmVhayB0aGUgYmxvY2sgb24gYSBmYXRhbCBzaWduYWwuLi4u CgpBbmQgdGhlbiwgb2YgY291cnNlLCBpcyB0aGUgY2FsbCBwYXRoIHRocm91Z2ggZG9fZXhpdCgp LCB3aGljaCBoYXMKdGhlIFBGX0VYSVRJTkcgdGFzayBmbGFnIHNldDoKCmRvX2V4aXQoKQogIGV4 aXRfdGFza193b3JrKCkKICAgIHRhc2tfd29ya19ydW4oKQogICAgICBfX2ZwdXQoKQoKYW5kIHNv IGl0J3MgZWFzeSB0byBhdm9pZCBibG9ja2luZyBpbiB0aGlzIGNhc2UsIHRvby4KClNvIHRoYXQg bGVhdmVzIGp1c3QgdGhlIG5vcm1hbCBjbG9zZSgpIHN5c2NhbGwgZXhpdCBjYXNlLCB3aGVyZSB0 aGUKYXBwbGljYXRpb24gaGFzIGZ1bGwgY29udHJvbCBvZiB0aGUgb3JkZXIgaW4gd2hpY2ggcmVz b3VyY2VzIGFyZQpyZWxlYXNlZC4gV2UndmUgYWxyZWFkeSBlc3RhYmxpc2hlZCB0aGF0IHdlIGNh biBibG9jayBpbiB0aGlzCmNvbnRleHQuICBCbG9ja2luZyBpbiBhbiBpbnRlcnJ1cHRpYmxlIHN0 YXRlIHdpbGwgYWxsb3cgZmF0YWwgc2lnbmFsCmRlbGl2ZXJ5IHRvIHdha2UgdXMsIGFuZCB0aGVu IHdlIGZhbGwgaW50byB0aGUKZmF0YWxfc2lnbmFsX3BlbmRpbmcoKSBjYXNlIGlmIHdlIGdldCBh IFNJR0tJTEwgd2hpbGUgYmxvY2tpbmcuCgpIZW5jZSBJIHRoaW5rIGJsb2NraW5nIGluIHRoaXMg Y2FzZSB3b3VsZCBiZSBPSyAtIGl0IGluZGljYXRlcyBhbgphcHBsaWNhdGlvbiBidWcgKHJlbGVh c2luZyBhIGxlYXNlIGJlZm9yZSByZWxlYXNpbmcgdGhlIHJlc291cmNlcykKYnV0IGxlYXZlcyBT SUdLSUxMIGF2YWlsYWJsZSB0byBhZG1pbmlzdHJhdG9ycyB0byByZXNvbHZlIHNpdHVhdGlvbnMK aW52b2x2aW5nIGJ1Z2d5IGFwcGxpY2F0aW9ucy4KClRoaXMgcmVxdWlyZXMgYXBwbGljYXRpb25z IHRvIGZvbGxvdyB0aGUgcnVsZXM6IGFueSBwcm9jZXNzCnRoYXQgcGlucyBwaHlzaWNhbCByZXNv dXJjZXMgbXVzdCBoYXZlIGFuIGFjdGl2ZSByZWZlcmVuY2UgdG8gYQpsYXlvdXQgbGVhc2UsIGVp dGhlciB2aWEgYSBkdXBsaWNhdGVkIGZkIG9yIGl0J3Mgb3duIHByaXZhdGUgbGVhc2UuCklmIHRo ZSBhcHAgZG9lc24ndCBwbGF5IGJ5IHRoZSBydWxlcywgaXQgaGFuZ3MgaW4gY2xvc2UoKSB1bnRp bCBpdAppcyBraWxsZWQuCgo+IE9yIHlvdSBjb3VsZCB3YWl0IGZvciBhbm90aGVyIHByb2Nlc3Mg dG8KPiByZWxlYXNlIHBhZ2UgcGlucyBhbmQgYmxvY2tpbmcgU0lHS0lMTCBvbiB0aGF0IGlzIGFs c28gYmFkLgoKQWdhaW4sIGVhY2ggaW5kaXZpZHVhbCBwcm9jZXNzIHRoYXQgcGlucyBwYWdlcyBm cm9tIHRoZSBsYXlvdXQgbXVzdApoYXZlIGl0J3Mgb3duIGFjdGl2ZSBsYXlvdXQgbGVhc2UgcmVm ZXJlbmNlLgoKPiBTbyBpbiB0aGUgZW5kCj4gdGhlIGxlYXN0IGJhZCBzb2x1dGlvbiB3ZSd2ZSBj b21lIHVwIHdpdGggd2VyZSB0aGVzZSAiem9tYmllIiBsZWFzZXMgYXMgeW91Cj4gY2FsbCB0aGVt IGFuZCB0cmFja2luZyB0aGVtIGluIC9wcm9jIHNvIHRoYXQgdXNlcnNwYWNlIGF0IGxlYXN0IGhh cyBhIHdheQo+IG9mIHNlZWluZyB0aGVtLiBCdXQgaWYgeW91IGNhbiBjb21lIHVwIHdpdGggYSBk aWZmZXJlbnQgc29sdXRpb24sIEknbQo+IGNlcnRhaW5seSBub3QgYXR0YWNoZWQgdG8gdGhlIGN1 cnJlbnQgb25lLi4uCgpJdCBtaWdodCBiZSB0aGUgImxlYXN0IGJhZCIgc29sdXRpb24sIGJ1dCBp dCdzIHN0aWxsIGEgcHJldHR5IGJhZApvbmUuIEFuZCBvbmUgdGhhdCBJIGRvbid0IHRoaW5rIGlz IG5lY2Vzc2FyeSBpZiB3ZSBzaW1wbHkgZW5mb3JjZQp0aGUgInByb2Nlc3MgbXVzdCBoYXZlIGFj dGl2ZSByZWZlcmVuY2VzIGZvciB0aGUgZW50aXJlIHRpbWUgdGhlCnByb2Nlc3MgdXNlcyB0aGUg cmVzb3VyY2UiIHJ1bGUuIFRoYXQncyB0aGUgd2F5IGZpbGUgYWNjZXNzIGhhcwphbHdheXMgd29y a2VkLCBJIGRvbid0IHNlZSB3aHkgd2Ugc2hvdWxkIGJlIGRvaW5nIGFueXRoaW5nIGRpZmZlcmVu dApmb3IgYWNjZXNzIHRvIHRoZSBwaHlzaWNhbCBsYXlvdXQgb2YgZmlsZXMuLi4KCkNoZWVycywK CkRhdmUuCi0tIApEYXZlIENoaW5uZXIKZGF2aWRAZnJvbW9yYml0LmNvbQpfX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpMaW51eC1udmRpbW0gbWFpbGluZyBs aXN0CkxpbnV4LW52ZGltbUBsaXN0cy4wMS5vcmcKaHR0cHM6Ly9saXN0cy4wMS5vcmcvbWFpbG1h bi9saXN0aW5mby9saW51eC1udmRpbW0K