From: Tejun Heo <teheo-l3A5Bk7waGM@public.gmane.org>
To: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Linux Containers
<containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org>,
Greg KH <greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>,
Greg KH <gregkh-l3A5Bk7waGM@public.gmane.org>,
Dave Hansen <hansendc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH 2/4] sysfs: Implement sysfs manged shadow directory support.
Date: Mon, 30 Jul 2007 16:09:06 +0900 [thread overview]
Message-ID: <46AD8E92.7080002@suse.de> (raw)
In-Reply-To: <46A425F9.1030008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Hello, Eric.
Tejun Heo wrote:
> Eric W. Biederman wrote:
>> Further while there are a few little nits I think mostly Tejun is
>> mostly objecting to the fundamental complexity of the problem rather
>> then to things that can be fixed by a cleaner implementation.
>
> Oh well, I don't think so but I might be wrong.
And I'm wrong. Mine didn't turn out to be much cleaner than yours.
What I did was (still broken)...
* No shadower/shadowee. Each dentry is tagged.
* dentries of tagged sd's are taken out of dcache and always go through
->lookup() where the correct sd is looked up considering the current tag.
Tagging and adding new entries could be done rather cleanly but shooting
down existing dentries on rename/move turned out to be a mess. Things
will be much simpler if no sysfs dentry is hashed on dcache and always
go through ->lookup() but that will hurt big machines.
The basic problem here is that dcache layer doesn't allow different
views and sysfs shadow is trying to work behind its back. I don't think
this is a viable approach. Both implementations bend too many rules and
are too fragile. It will be a genuine pain in the ass to maintain.
Sorry that I can't come up with an alternative but NACK.
--
tejun
next prev parent reply other threads:[~2007-07-30 7:09 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4676C798.2090404@bull.net>
[not found] ` <1182446577.8138.29.camel@localhost>
[not found] ` <m1odj9dofp.fsf@ebiederm.dsl.xmission.com>
[not found] ` <20070621211637.GB10583@suse.de>
[not found] ` <m1fy4ldldm.fsf@ebiederm.dsl.xmission.com>
[not found] ` <20070622001328.GA14113@suse.de>
[not found] ` <m1tzt0cujt.fsf_-_@ebiederm.dsl.xmission.com>
[not found] ` <20070625212339.GA13398@kroah.com>
[not found] ` <20070625212339.GA13398-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2007-07-19 4:43 ` [PATCH 1/4] sysfs: Remove first pass at shadow directory support Eric W. Biederman
[not found] ` <m14pk13svx.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-19 4:45 ` [PATCH 2/4] sysfs: Implement sysfs manged " Eric W. Biederman
[not found] ` <m1zm1t2e92.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-19 4:46 ` [PATCH 3/4] sysfs: Implement sysfs_delete_link and sysfs_rename_link Eric W. Biederman
[not found] ` <m1vech2e6o.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-19 4:47 ` [PATCH 4/4] driver core: Implement shadow directory support for device classes Eric W. Biederman
[not found] ` <m1r6n52e5c.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-21 6:36 ` patch driver-core-implement-shadow-directory-support-for-device-classes.patch added to gregkh-2.6 tree gregkh-l3A5Bk7waGM
[not found] ` <20070721063634.9337314458DB-j1pC+zEt+uWoYr4blSSd5g@public.gmane.org>
2007-07-21 10:00 ` Eric W. Biederman
2007-07-21 6:36 ` patch sysfs-implement-sysfs_delete_link-and-sysfs_rename_link.patch " gregkh-l3A5Bk7waGM
2007-07-21 6:36 ` patch sysfs-implement-sysfs-manged-shadow-directory-support.patch " gregkh-l3A5Bk7waGM
2007-07-22 19:47 ` [PATCH 2/4] sysfs: Implement sysfs manged shadow directory support Tejun Heo
[not found] ` <46A3B449.3090409-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-07-22 20:25 ` Greg KH
[not found] ` <20070722202508.GA18018-l3A5Bk7waGM@public.gmane.org>
2007-07-22 22:19 ` Eric W. Biederman
[not found] ` <m17iosw075.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-23 3:52 ` Tejun Heo
[not found] ` <46A425F9.1030008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-07-24 7:26 ` Greg KH
2007-07-30 7:09 ` Tejun Heo [this message]
[not found] ` <46AD8E92.7080002-l3A5Bk7waGM@public.gmane.org>
2007-07-30 12:41 ` Kirill Korotaev
[not found] ` <46ADDC7F.1090306-3ImXcnM4P+0@public.gmane.org>
2007-07-30 13:06 ` Tejun Heo
[not found] ` <46ADE24E.8020502-l3A5Bk7waGM@public.gmane.org>
2007-07-30 13:57 ` Kirill Korotaev
[not found] ` <46ADEE35.8000109-3ImXcnM4P+0@public.gmane.org>
2007-07-30 14:04 ` Tejun Heo
[not found] ` <46ADF003.3010100-l3A5Bk7waGM@public.gmane.org>
2007-07-30 15:51 ` Eric W. Biederman
[not found] ` <m1ps29vqin.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 3:24 ` Eric W. Biederman
[not found] ` <m1k5shuugc.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 3:41 ` Tejun Heo
[not found] ` <46AEAF79.6080404-l3A5Bk7waGM@public.gmane.org>
2007-07-31 4:02 ` Eric W. Biederman
[not found] ` <m1fy35uso4.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 4:28 ` Tejun Heo
[not found] ` <46AEBA87.6000400-l3A5Bk7waGM@public.gmane.org>
2007-07-31 7:59 ` Eric W. Biederman
[not found] ` <m1bqdtt34l.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 8:14 ` Tejun Heo
[not found] ` <46AEEF75.2030101-l3A5Bk7waGM@public.gmane.org>
2007-07-31 8:15 ` Tejun Heo
[not found] ` <46AEEFA6.4000901-l3A5Bk7waGM@public.gmane.org>
2007-07-31 10:16 ` [PATCH 0/14] sysfs cleanups Eric W. Biederman
[not found] ` <m14pjkubd2.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:18 ` [PATCH 01/14] sysfs: Remove first pass at shadow directory support Eric W. Biederman
[not found] ` <m1zm1cswp0.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:20 ` [PATCH 02/14] sysfs: In sysfs_lookup protect s_parent with sysfs_mutex Eric W. Biederman
[not found] ` <m1vec0swmi.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:22 ` [PATCH 03/14] sysfs: Move all of inode initialization into sysfs_init_inode Eric W. Biederman
[not found] ` <m1r6moswhr.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:24 ` [PATCH 04/14] sysfs: Remove unnecessary variable found from sysfs_lookup Eric W. Biederman
[not found] ` <m1myxcswfr.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:25 ` [PATCH 05/14] sysfs: Remove sysfs_instantiate Eric W. Biederman
[not found] ` <m1ir80swdl.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:27 ` [PATCH 06/14] sysfs: Rewrite sysfs_get_dentry Eric W. Biederman
[not found] ` <m1ejioswai.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:28 ` [PATCH 07/14] vfs: Remove lookup_one_len_kern Eric W. Biederman
[not found] ` <m1abtcsw8w.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:29 ` [PATCH 08/14] sysfs: Perform renames under sysfs_mutex Eric W. Biederman
[not found] ` <m16440sw6d.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:33 ` [PATCH 09/14] sysfs: Move all of sysfs_move_dir " Eric W. Biederman
[not found] ` <m11weosvzz.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:37 ` [PATCH 10/14] sysfs: Rework sysfs_drop_dentry Eric W. Biederman
[not found] ` <m1wswgrh8x.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:39 ` [PATCH 11/14] sysfs: Remove s_dentry form sysfs_dirent Eric W. Biederman
[not found] ` <m1sl74rh6e.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:40 ` [PATCH 12/14] sysfs: Make sysfs_mount static Eric W. Biederman
[not found] ` <m1odhsrh46.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:42 ` [PATCH 13/14] sysfs: Simplify readdir Eric W. Biederman
[not found] ` <m1k5sgrh1h.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:42 ` [PATCH 14/14] sysfs: In sysfs_lookup don't open code sysfs_find_dirent Eric W. Biederman
[not found] ` <m1fy34rh08.fsf_-_-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 11:38 ` Tejun Heo
[not found] ` <46AF1F28.3000101-l3A5Bk7waGM@public.gmane.org>
2007-07-31 16:01 ` Eric W. Biederman
2007-07-31 11:36 ` [PATCH 13/14] sysfs: Simplify readdir Tejun Heo
2007-07-31 11:19 ` [PATCH 12/14] sysfs: Make sysfs_mount static Tejun Heo
2007-07-31 11:18 ` [PATCH 11/14] sysfs: Remove s_dentry form sysfs_dirent Tejun Heo
2007-07-31 11:17 ` [PATCH 10/14] sysfs: Rework sysfs_drop_dentry Tejun Heo
2007-07-31 11:09 ` [PATCH 09/14] sysfs: Move all of sysfs_move_dir under sysfs_mutex Tejun Heo
2007-07-31 11:06 ` [PATCH 08/14] sysfs: Perform renames " Tejun Heo
[not found] ` <46AF17A1.2010203-l3A5Bk7waGM@public.gmane.org>
2007-07-31 11:10 ` Tejun Heo
2007-07-31 10:59 ` [PATCH 06/14] sysfs: Rewrite sysfs_get_dentry Tejun Heo
[not found] ` <46AF15F6.6010202-l3A5Bk7waGM@public.gmane.org>
2007-07-31 11:23 ` Eric W. Biederman
[not found] ` <m11weorf3l.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 11:34 ` Tejun Heo
[not found] ` <46AF1E57.3030209-l3A5Bk7waGM@public.gmane.org>
2007-07-31 14:16 ` Tejun Heo
[not found] ` <20070731141613.GC13674-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2007-07-31 19:24 ` Eric W. Biederman
2007-08-01 9:22 ` Eric W. Biederman
[not found] ` <m1fy33pq1r.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-08-01 10:02 ` Tejun Heo
[not found] ` <46B05A1D.5000703-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-08-01 17:07 ` Eric W. Biederman
[not found] ` <m1vebznpyc.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-08-01 17:20 ` Tejun Heo
[not found] ` <46B0C0E6.5030008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-08-01 17:40 ` Eric W. Biederman
[not found] ` <m1ir7znog9.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-08-01 17:51 ` Tejun Heo
[not found] ` <46B0C817.7060106-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-08-02 8:28 ` Cornelia Huck
[not found] ` <20070802102819.183720a4-XQvu0L+U/CiXI4yAdoq52KN5r0PSdgG1zG2AekJRRhI@public.gmane.org>
2007-08-03 19:29 ` Eric W. Biederman
[not found] ` <m1tzrgl8mo.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-08-06 15:06 ` Cornelia Huck
2007-07-31 10:44 ` [PATCH 05/14] sysfs: Remove sysfs_instantiate Tejun Heo
2007-07-31 10:45 ` [PATCH 04/14] sysfs: Remove unnecessary variable found from sysfs_lookup Tejun Heo
2007-07-31 10:43 ` [PATCH 03/14] sysfs: Move all of inode initialization into sysfs_init_inode Tejun Heo
2007-07-31 10:36 ` [PATCH 02/14] sysfs: In sysfs_lookup protect s_parent with sysfs_mutex Tejun Heo
[not found] ` <46AF10B7.3070600-l3A5Bk7waGM@public.gmane.org>
2007-07-31 10:45 ` Eric W. Biederman
[not found] ` <m1bqdsrgvy.fsf-T1Yj925okcoyDheHMi7gv2pdwda3JcWeAL8bYrjMMd8@public.gmane.org>
2007-07-31 10:47 ` Tejun Heo
2007-07-31 3:51 ` [PATCH 2/4] sysfs: Implement sysfs manged shadow directory support Tejun Heo
2007-07-26 8:00 ` Tejun Heo
[not found] ` <46A85485.40502-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-07-27 10:58 ` [Devel] " Kirill Korotaev
2007-07-27 20:59 ` Carl-Daniel Hailfinger
2007-07-30 15:36 ` Eric W. Biederman
2007-07-22 22:07 ` Eric W. Biederman
2007-07-21 6:36 ` patch sysfs-remove-first-pass-at-shadow-directory-support.patch added to gregkh-2.6 tree gregkh-l3A5Bk7waGM
2007-07-22 18:35 ` [PATCH 1/4] sysfs: Remove first pass at shadow directory support Tejun Heo
[not found] ` <46A3A36F.9070904-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-07-22 19:17 ` Eric W. Biederman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=46AD8E92.7080002@suse.de \
--to=teheo-l3a5bk7wagm@public.gmane.org \
--cc=containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org \
--cc=ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org \
--cc=greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org \
--cc=gregkh-l3A5Bk7waGM@public.gmane.org \
--cc=hansendc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.