From: Tejun Heo <htejun@gmail.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg KH <gregkh@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Daniel Lezcano <dlezcano@fr.ibm.com>,
linux-kernel@vger.kernel.org, Al Viro <viro@ftp.linux.org.uk>,
Linux Containers <containers@lists.osdl.org>,
Benjamin Thery <benjamin.thery@bull.net>,
netdev@vger.kernel.org
Subject: Re: [PATCH 12/15] driver core: Implement tagged directory support for device classes.
Date: Wed, 16 Jul 2008 14:50:02 +0900 [thread overview]
Message-ID: <487D8C0A.9060100@gmail.com> (raw)
In-Reply-To: <m17ibmbd39.fsf@frodo.ebiederm.org>
Hello,
Eric W. Biederman wrote:
>> Eric, with the multiple superblocks, sysfs now uses inode from the
>> default sysfs_sb with dentries from other sb's. Is this okay? Are
>> there any other filesystems which do this?
>
> I don't know of any other filesystems where this unique challenge arises.
> /proc almost qualifies but it never needs to be modified.
>
> It is certainly ok to go from multiple dentries to a single inode.
> I'm trying to remember why I choose to do that. I think both because it simplifies
> the locking and keeps us more efficient in the icache.
It's a bit scary tho. Working inode->i_dentry or dentry->d_alias
crosses multiple sb's. sysfs isn't too greedy about dcache/icache.
Only open files and directories hold them and only single copy of
sysfs_dirent is there for most nodes. Wouldn't it be better to stay on
the safer side and use separate inode hierarchy?
Thanks.
--
tejun
next prev parent reply other threads:[~2008-07-16 5:50 UTC|newest]
Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-18 17:07 [PATCH 00/11] sysfs tagged directories V6 Benjamin Thery
2008-06-18 17:07 ` [PATCH 01/11] sysfs: Support for preventing unmounts Benjamin Thery
2008-06-18 17:44 ` Dave Hansen
2008-06-18 20:12 ` Eric W. Biederman
2008-06-19 8:54 ` Benjamin Thery
2008-06-19 16:32 ` Dave Hansen
2008-06-19 20:19 ` Benjamin Thery
2008-06-18 17:07 ` [PATCH 02/11] sysfs: sysfs_get_dentry add a sb parameter Benjamin Thery
2008-06-18 17:07 ` [PATCH 03/11] sysfs: Implement __sysfs_get_dentry Benjamin Thery
2008-06-18 17:08 ` [PATCH 04/11] sysfs: Rename Support multiple superblocks Benjamin Thery
2008-06-18 17:08 ` [PATCH 05/11] sysfs: sysfs_chmod_file handle " Benjamin Thery
2008-06-22 4:46 ` Tejun Heo
2008-06-23 21:42 ` Daniel Lezcano
2008-06-24 4:45 ` Tejun Heo
2008-06-24 10:39 ` Daniel Lezcano
2008-06-24 13:37 ` Daniel Lezcano
2008-06-25 12:31 ` Tejun Heo
2008-06-18 17:08 ` [PATCH 06/11] sysfs: Implement sysfs tagged directory support Benjamin Thery
2008-06-23 2:05 ` Tejun Heo
2008-06-26 20:21 ` Eric W. Biederman
2008-06-29 3:51 ` Tejun Heo
2008-06-30 18:56 ` Eric W. Biederman
2008-06-30 21:44 ` Serge E. Hallyn
2008-07-01 7:50 ` Eric W. Biederman
2008-07-01 6:47 ` Tejun Heo
2008-07-01 9:20 ` Eric W. Biederman
2008-07-01 10:30 ` Tejun Heo
2008-07-01 12:30 ` Eric W. Biederman
2008-07-02 3:24 ` Tejun Heo
2008-07-02 3:53 ` Eric W. Biederman
2008-07-02 4:37 ` Tejun Heo
2008-07-02 16:49 ` Eric W. Biederman
2008-07-03 0:15 ` Greg KH
2008-07-03 3:18 ` Tejun Heo
2008-07-03 5:11 ` Eric W. Biederman
2008-07-03 10:56 ` Daniel Lezcano
2008-07-03 12:27 ` Eric W. Biederman
2008-07-03 12:37 ` Benjamin Thery
2008-07-03 19:57 ` Eric W. Biederman
2008-07-03 12:55 ` Daniel Lezcano
2008-07-03 15:58 ` Tejun Heo
2008-07-03 18:29 ` Daniel Lezcano
2008-07-03 20:08 ` Eric W. Biederman
2008-07-04 0:48 ` [PATCH 00/15] sysfs support for namespaces Eric W. Biederman
2008-07-04 1:05 ` [PATCH 01/15] kobject: Cleanup kobject_rename and !CONFIG_SYSFS Eric W. Biederman
2008-07-04 1:07 ` [PATCH 02/15] sysfs: Support for preventing unmounts Eric W. Biederman
2008-07-04 1:08 ` [PATCH 03/15] sysfs: sysfs_get_dentry add a sb parameter Eric W. Biederman
2008-07-04 1:09 ` [PATCH 04/15] sysfs: Implement __sysfs_get_dentry Eric W. Biederman
2008-07-04 1:10 ` [PATCH 05/15] sysfs: Rename Support multiple superblocks Eric W. Biederman
2008-07-04 1:11 ` [PATCH 06/15] Introduce sysfs_sd_setattr and fix sysfs_chmod Eric W. Biederman
2008-07-04 1:13 ` [PATCH 07/15] sysfs: sysfs_chmod_file handle multiple superblocks Eric W. Biederman
2008-07-04 1:14 ` [PATCH 08/15] sysfs: Make sysfs_mount static once again Eric W. Biederman
2008-07-04 1:16 ` [PATCH 09/15] sysfs: Implement sysfs tagged directory support Eric W. Biederman
2008-07-04 1:17 ` [PATCH 10/15] sysfs: Merge sysfs_rename_dir and sysfs_move_dir Eric W. Biederman
2008-07-04 1:18 ` [PATCH 11/15] sysfs: Implement sysfs_delete_link and sysfs_rename_link Eric W. Biederman
2008-07-04 1:20 ` [PATCH 12/15] driver core: Implement tagged directory support for device classes Eric W. Biederman
2008-07-04 1:21 ` [PATCH 13/15] Revert "netns: Fix device renaming for sysfs" Eric W. Biederman
2008-07-04 1:22 ` [PATCH 14/15] netns: Enable tagging for net_class directories in sysfs Eric W. Biederman
2008-07-04 1:23 ` [PATCH 15/15] sysfs: user namespaces: fix bug with clone(CLONE_NEWUSER) with fairsched Eric W. Biederman
2008-07-04 7:50 ` [PATCH 12/15] driver core: Implement tagged directory support for device classes Tejun Heo
2008-07-04 13:31 ` Eric W. Biederman
2008-07-04 13:57 ` Tejun Heo
2008-07-04 16:12 ` Greg KH
2008-07-04 21:49 ` Eric W. Biederman
2008-07-14 1:54 ` Eric W. Biederman
2008-07-16 3:25 ` Tejun Heo
2008-07-16 5:41 ` Eric W. Biederman
2008-07-16 5:50 ` Tejun Heo [this message]
2008-07-16 6:32 ` Eric W. Biederman
2008-07-16 6:48 ` Tejun Heo
2008-07-16 7:02 ` Tejun Heo
2008-07-16 19:07 ` Eric W. Biederman
2008-07-16 21:09 ` Eric W. Biederman
2008-07-17 23:08 ` Greg KH
2008-07-18 12:41 ` Tejun Heo
2008-07-18 18:49 ` Greg KH
2008-07-18 20:19 ` Eric W. Biederman
2008-07-19 1:07 ` Tejun Heo
2008-08-03 6:59 ` Eric W. Biederman
2008-09-11 12:45 ` Jiri Slaby
2008-09-11 13:05 ` Benjamin Thery
2008-09-12 6:32 ` Jiri Slaby
2008-07-04 22:00 ` Eric W. Biederman
2008-08-20 2:17 ` [PATCH 09/15] sysfs: Implement sysfs tagged directory support Greg KH
2008-08-20 6:58 ` Eric W. Biederman
2008-08-21 6:31 ` [PATCH 0/8] sysfs namespace support Eric W. Biederman
2008-08-21 6:33 ` [PATCH 1/8] sysfs: Implement sysfs tagged directory support Eric W. Biederman
2008-08-21 6:34 ` [PATCH 2/8] sysfs: Merge sysfs_rename_dir and sysfs_move_dir Eric W. Biederman
2008-08-21 6:35 ` [PATCH 3/8] sysfs: Implement sysfs_delete_link and sysfs_rename_link Eric W. Biederman
2008-08-21 6:36 ` [PATCH 5/8] sysfs: Remove sysfs_create_link_nowarn Eric W. Biederman
2008-08-21 6:38 ` [PATCH 6/8] Revert "netns: Fix device renaming for sysfs" Eric W. Biederman
2008-08-21 6:39 ` [PATCH 7/8] netns: Enable tagging for net_class directories in sysfs Eric W. Biederman
2008-08-21 6:40 ` [PATCH 8/8] sysfs: user namespaces: fix bug with clone(CLONE_NEWUSER) with fairsched Eric W. Biederman
2008-08-21 6:47 ` [PATCH 7/8] netns: Enable tagging for net_class directories in sysfs David Miller
2008-08-21 6:47 ` [PATCH 6/8] Revert "netns: Fix device renaming for sysfs" David Miller
2008-08-21 6:37 ` [PATCH 4/8] driver core: Implement tagged directory support for device classes Eric W. Biederman
2008-08-27 15:18 ` [PATCH 1/8] sysfs: Implement sysfs tagged directory support Benjamin Thery
2008-09-02 13:54 ` Mark Ryden
2008-09-02 14:03 ` Benjamin Thery
2008-09-02 17:01 ` Greg KH
2008-09-04 5:33 ` David Shwatrz
2008-09-04 6:44 ` Benjamin Thery
2008-09-08 18:39 ` Mark Ryden
2008-10-07 16:39 ` Mark Ryden
2008-10-07 16:48 ` Greg KH
2008-10-07 20:31 ` Eric W. Biederman
2008-10-07 21:09 ` Greg KH
2008-10-07 22:27 ` Eric W. Biederman
2008-10-08 13:00 ` Christoph Hellwig
2008-10-14 3:20 ` Eric W. Biederman
2008-10-07 16:52 ` Daniel Lezcano
2008-08-21 6:37 ` [PATCH 0/8] sysfs namespace support David Miller
2008-07-04 6:44 ` [PATCH 08/15] sysfs: Make sysfs_mount static once again Tejun Heo
2008-07-04 6:44 ` [PATCH 07/15] sysfs: sysfs_chmod_file handle multiple superblocks Tejun Heo
2008-07-04 6:40 ` [PATCH 06/15] Introduce sysfs_sd_setattr and fix sysfs_chmod Tejun Heo
2008-07-04 6:33 ` [PATCH 01/15] kobject: Cleanup kobject_rename and !CONFIG_SYSFS Tejun Heo
2008-07-04 1:27 ` [PATCH 00/15] sysfs support for namespaces Eric W. Biederman
2008-07-06 4:42 ` Eric W. Biederman
2008-07-07 11:41 ` Cornelia Huck
2008-07-07 12:22 ` Eric W. Biederman
2008-06-18 17:08 ` [PATCH 07/11] sysfs: Implement sysfs_delete_link and sysfs_rename_link Benjamin Thery
2008-06-23 2:13 ` Tejun Heo
2008-06-26 20:24 ` Eric W. Biederman
2008-06-29 3:35 ` Tejun Heo
2008-06-30 3:02 ` Eric W. Biederman
2008-06-18 17:08 ` [PATCH 08/11] driver core: Implement tagged directory support for device classes Benjamin Thery
2008-06-18 17:08 ` [PATCH 09/11] sysfs: add sysfs_ns_exit routine Benjamin Thery
2008-06-18 20:19 ` Eric W. Biederman
2008-06-23 2:16 ` Tejun Heo
2008-06-18 17:09 ` [PATCH 10/11] netns: Enable tagging for net_class directories in sysfs Benjamin Thery
2008-06-23 2:18 ` Tejun Heo
2008-06-18 17:09 ` [PATCH 11/11] sysfs: user namespaces: fix bug with clone(CLONE_NEWUSER) with fairsched Benjamin Thery
2008-06-23 2:18 ` Tejun Heo
2008-06-25 18:44 ` Serge E. Hallyn
2008-06-25 21:11 ` Eric W. Biederman
2008-06-26 13:07 ` Serge E. Hallyn
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