From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Kulikov Subject: Re: [PATCH v2] /proc/pid/status: show all sets of pid according to ns Date: Sat, 31 May 2014 10:07:13 +0400 Message-ID: <20140531060713.GA5315@cachalot> References: <1401272683-1659-1-git-send-email-chenhanxiao@cn.fujitsu.com> <5385DA19.2060008@parallels.com> <20140528182824.GA5057@cachalot> <53863889.9080509@parallels.com> <20140529055954.GA10354@cachalot> <5386F8EA.8050501@parallels.com> <20140529111236.GA14576@cachalot> <53871A92.9000004@parallels.com> <20140529115946.GA19889@cachalot> <53872DAD.1070502@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <53872DAD.1070502-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Pavel Emelyanov Cc: Richard Weinberger , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Serge Hallyn , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Oleg Nesterov , David Howells , "Eric W. Biederman" , Andrew Morton , Al Viro List-Id: containers.vger.kernel.org T24gVGh1LCBNYXkgMjksIDIwMTQgYXQgMTY6NTMgKzA0MDAsIFBhdmVsIEVtZWx5YW5vdiB3cm90 ZToKPiBPbiAwNS8yOS8yMDE0IDAzOjU5IFBNLCBWYXNpbHkgS3VsaWtvdiB3cm90ZToKPiA+IE9u IFRodSwgTWF5IDI5LCAyMDE0IGF0IDE1OjMxICswNDAwLCBQYXZlbCBFbWVseWFub3Ygd3JvdGU6 Cj4gPj4gT24gMDUvMjkvMjAxNCAwMzoxMiBQTSwgVmFzaWx5IEt1bGlrb3Ygd3JvdGU6Cj4gPj4+ IE9uIFRodSwgTWF5IDI5LCAyMDE0IGF0IDEzOjA3ICswNDAwLCBQYXZlbCBFbWVseWFub3Ygd3Jv dGU6Cj4gPj4+PiBPbiAwNS8yOS8yMDE0IDA5OjU5IEFNLCBWYXNpbHkgS3VsaWtvdiB3cm90ZToK PiA+Pj4+PiBPbiBXZWQsIE1heSAyOCwgMjAxNCBhdCAyMzoyNyArMDQwMCwgUGF2ZWwgRW1lbHlh bm92IHdyb3RlOgo+ID4+Pj4+IF0gV2UgbmVlZCBhIGRpcmVjdCBtZXRob2Qgb2YgZ2V0dGluZyB0 aGUgcGlkIGluc2lkZSBjb250YWluZXJzLgo+ID4+Pj4+IF0gSWYgc29tZSBpc3N1ZXMgb2NjdXJy ZWQgaW5zaWRlIGNvbnRhaW5lciBndWVzdCwgaG9zdCB1c2VyCj4gPj4+Pj4gXSBjb3VsZCBub3Qg a25vdyB3aGljaCBwcm9jZXNzIGlzIGluIHRyb3VibGUganVzdCBieSBndWVzdCBwaWQ6Cj4gPj4+ Pj4gXSB0aGUgdXNlcnMgb2YgY29udGFpbmVyIGd1ZXN0IG9ubHkga25ldyB0aGUgcGlkIGluc2lk ZSBjb250YWluZXJzLgo+ID4+Pj4+IF0gVGhpcyB3aWxsIGJyaW5nIG9ic3RhY2xlIGZvciB0cm91 YmxlIHNob290aW5nLgo+ID4+Pj4+Cj4gPj4+Pj4gQSBuZXcgc3lzY2FsbCBtaWdodCBjb21wbGlj YXRlIHRyb3VibGUgc2hvb3RpbmcgYnkgYWRtaW4uCj4gPj4+Pgo+ID4+Pj4gUHVyZSBzeXNjYWxs IC0tIHllcy4gV2hhdCBpZiB3ZSB0ZWFjaCB0aGUgcHMgYW5kIHRvcCB1dGlsaXRpZXMgdG8gc2hv dyBhZGRpdGlvbmFsCj4gPj4+PiBpbmZvPyBJIHRoaW5rIHRoYXQgd291bGQgaGVscC4KPiA+Pj4K PiA+Pj4gSSBsaWtlIHRoZSBpZGVhIHdpdGggbG93IGxldmVsIG5vbi1zaGVsbCBBUEkgd2hpY2gg Y2FuIGJlIHVzZWQgYnkKPiA+Pj4gdXRpbGl0eSBsaWtlIHBzIChvciBpbXBsZW1lbnRhdGlvbiBv ZiBhIG5ldyB0b29sIHRvIHdvcmsgd2l0aCBjb21wbGV4Cj4gPj4+IG5hbWVzcGFjZSBoaWVyYXJj aGllcykuICBJdCBzaG91bGQgZml0IGZvciB0cm91Ymxlc29vdGluZy4gIFRoZW4gdGhlcmUKPiA+ Pj4gc2hvdWxkIGJlIG5vIHJlYXNvbiB0byBpbXBsZW1lbnQgdHdvIGRpZmZlcmVudCBBUElzIGZv ciBvYnNlcnZhdGlvbiBmcm9tCj4gPj4+IHNoZWxsIHZpYSBGUyBhbmQgZnJvbSBhcHBsaWNhdGlv bnMuCj4gPj4KPiA+PiBNYXliZSB3ZSBjYW4gcmV1c2UgdGhlIGV4aXN0aW5nIGtjbXAoKSBzeXN0 ZW0gY2FsbD8gV2Ugd291bGQgaGF2ZSB0byBzdG9yZQo+ID4+IHRoZSBjb2xsZWN0ZWQgcGlkIHZh bHVlcyBpbiBzb21lIGhhc2gvdHJlZSBhbnl3YXksIGFuZCBrY21wKCkgcHJvdmlkZXMgdXMKPiA+ PiBnb29kIGNvbXBhcmluZyBmdW5jdGlvbiBmb3IgZG9pbmcgdGhpcy4KPiA+Pgo+ID4+IExpa2Ug d2UgY2FuIGNhbGwga2NtcChwaWQxLCBwaWQyLCBLQ01QX1BJRCwgbnNmZDEsIG5zZmQyKSB3aGlj aCB3aWxsIG1lYW4KPiA+PiAiQXJlIHRhc2tzIHdpdGggcGlkMSBpbiBuYW1lc3BhY2UgcG9pbnRl ZCBieSBuc2ZkMSBhbmQgd2l0aCBwaWQyIGluIG5hbWVzcGFjZQo+ID4+IG5zZmQyIHRoZSBzYW1l PyIKPiA+Pgo+ID4+IFdoYXQgZG8geW91IHRoaW5rPwo+ID4gCj4gPiBrY21wKCkgaXMgbm90IG5l ZWRlZCwganVzdCBjb21wYXJlIGlub2RlIG51bWJlcnM6Cj4gPiAKPiA+ICAgICAjIGxzIC1pbCAv cHJvYy97NDMsc2VsZn0vbnMvbW50Cj4gPiAgICAgMjA4MTgyIGxyd3hyd3hyd3ggMSByb290IHJv b3QgMCDQvNCw0Y8gICAyOSAxNTo1MiAvcHJvYy80My9ucy9tbnQgLT4gbW50Ols0MDI2NTMxODU2 XQo+ID4gICAgIDIxNjU1NiBscnd4cnd4cnd4IDEgcm9vdCByb290IDAg0LzQsNGPICAgMjkgMTU6 NTcgL3Byb2Mvc2VsZi9ucy9tbnQgLT4gbW50Ols0MDI2NTMxODQwXQo+IAo+IEJ1dCB0aGF0J3Mg Zm9yIGNvbXBhcmluZyB0aGUgbmFtZXNwYWNlcywgd2hpbGUgSSdtIHByb3Bvc2luZyB0aGUga2Nt cCB0bwo+IGNoZWNrIGZvciBQSURzLgoKSG0sIHJpZ2h0LgoKV2hhdCBhYm91dCB0aGUgZm9sbG93 aW5nIHNvbHV0aW9uOiBleHBvcnQgZ2xvYmFsIHByb2Nlc3MgSUQgKFBJRCBpbgppbml0IG5zKSB3 aGljaCBpcyB2aXNpYmxlIGluc2lkZSBvZiBhbnkgbmFtZXNwYWNlLiAgVGhlbiB5b3UgY2FuIGNv bXBhcmUKbnVtYmVycyByZWdhcmRsZXNzIGluIHdoYXQgbmFtZXNwYWNlIHlvdSBhcmUuCgotLSAK VmFzaWx5IEt1bGlrb3YKaHR0cDovL3d3dy5vcGVud2FsbC5jb20gLSBicmluZ2luZyBzZWN1cml0 eSBpbnRvIG9wZW4gY29tcHV0aW5nIGVudmlyb25tZW50cwpfX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fXwpDb250YWluZXJzIG1haWxpbmcgbGlzdApDb250YWlu ZXJzQGxpc3RzLmxpbnV4LWZvdW5kYXRpb24ub3JnCmh0dHBzOi8vbGlzdHMubGludXhmb3VuZGF0 aW9uLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2NvbnRhaW5lcnM= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751983AbaEaGHV (ORCPT ); Sat, 31 May 2014 02:07:21 -0400 Received: from mail-la0-f47.google.com ([209.85.215.47]:49371 "EHLO mail-la0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121AbaEaGHT (ORCPT ); Sat, 31 May 2014 02:07:19 -0400 Date: Sat, 31 May 2014 10:07:13 +0400 From: Vasily Kulikov To: Pavel Emelyanov Cc: Richard Weinberger , containers@lists.linux-foundation.org, Serge Hallyn , linux-kernel@vger.kernel.org, Oleg Nesterov , David Howells , "Eric W. Biederman" , Andrew Morton , Al Viro Subject: Re: [PATCH v2] /proc/pid/status: show all sets of pid according to ns Message-ID: <20140531060713.GA5315@cachalot> References: <1401272683-1659-1-git-send-email-chenhanxiao@cn.fujitsu.com> <5385DA19.2060008@parallels.com> <20140528182824.GA5057@cachalot> <53863889.9080509@parallels.com> <20140529055954.GA10354@cachalot> <5386F8EA.8050501@parallels.com> <20140529111236.GA14576@cachalot> <53871A92.9000004@parallels.com> <20140529115946.GA19889@cachalot> <53872DAD.1070502@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <53872DAD.1070502@parallels.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 29, 2014 at 16:53 +0400, Pavel Emelyanov wrote: > On 05/29/2014 03:59 PM, Vasily Kulikov wrote: > > On Thu, May 29, 2014 at 15:31 +0400, Pavel Emelyanov wrote: > >> On 05/29/2014 03:12 PM, Vasily Kulikov wrote: > >>> On Thu, May 29, 2014 at 13:07 +0400, Pavel Emelyanov wrote: > >>>> On 05/29/2014 09:59 AM, Vasily Kulikov wrote: > >>>>> On Wed, May 28, 2014 at 23:27 +0400, Pavel Emelyanov wrote: > >>>>> ] We need a direct method of getting the pid inside containers. > >>>>> ] If some issues occurred inside container guest, host user > >>>>> ] could not know which process is in trouble just by guest pid: > >>>>> ] the users of container guest only knew the pid inside containers. > >>>>> ] This will bring obstacle for trouble shooting. > >>>>> > >>>>> A new syscall might complicate trouble shooting by admin. > >>>> > >>>> Pure syscall -- yes. What if we teach the ps and top utilities to show additional > >>>> info? I think that would help. > >>> > >>> I like the idea with low level non-shell API which can be used by > >>> utility like ps (or implementation of a new tool to work with complex > >>> namespace hierarchies). It should fit for troublesooting. Then there > >>> should be no reason to implement two different APIs for observation from > >>> shell via FS and from applications. > >> > >> Maybe we can reuse the existing kcmp() system call? We would have to store > >> the collected pid values in some hash/tree anyway, and kcmp() provides us > >> good comparing function for doing this. > >> > >> Like we can call kcmp(pid1, pid2, KCMP_PID, nsfd1, nsfd2) which will mean > >> "Are tasks with pid1 in namespace pointed by nsfd1 and with pid2 in namespace > >> nsfd2 the same?" > >> > >> What do you think? > > > > kcmp() is not needed, just compare inode numbers: > > > > # ls -il /proc/{43,self}/ns/mnt > > 208182 lrwxrwxrwx 1 root root 0 мая 29 15:52 /proc/43/ns/mnt -> mnt:[4026531856] > > 216556 lrwxrwxrwx 1 root root 0 мая 29 15:57 /proc/self/ns/mnt -> mnt:[4026531840] > > But that's for comparing the namespaces, while I'm proposing the kcmp to > check for PIDs. Hm, right. What about the following solution: export global process ID (PID in init ns) which is visible inside of any namespace. Then you can compare numbers regardless in what namespace you are. -- Vasily Kulikov http://www.openwall.com - bringing security into open computing environments