From: "Eric W. Biederman" <ebiederm@xmission.com>
To: <linux-kernel@vger.kernel.org>
Cc: <linux-fsdevel@vger.kernel.org>, <netdev@vger.kernel.org>,
Lucian Adrian Grijincu <lucian.grijincu@gmail.com>,
Damien Millescamps <damien.millescamps@6wind.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: [PATCH 15/29] sysctl: Initial support for auto-unregistering sysctl tables.
Date: Thu, 26 Jan 2012 20:51:51 -0800 [thread overview]
Message-ID: <1327639925-12920-15-git-send-email-ebiederm@xmission.com> (raw)
In-Reply-To: <m1pqe5ah3z.fsf@fess.ebiederm.org>
Add nreg to ctl_table_header. When nreg drops to 0 the ctl_table_header
will be unregistered.
Factor out drop_sysctl_table from unregister_sysctl_table, and add
the logic for decrementing nreg.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
fs/proc/proc_sysctl.c | 28 +++++++++++++++++++---------
include/linux/sysctl.h | 1 +
2 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 1544485..13faa48 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -29,8 +29,9 @@ static struct ctl_table root_table[1];
static struct ctl_table_root sysctl_table_root;
static struct ctl_table_header root_table_header = {
{{.count = 1,
- .ctl_table = root_table,
- .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
+ .nreg = 1,
+ .ctl_table = root_table,
+ .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
.root = &sysctl_table_root,
.set = &sysctl_table_root.default_set,
};
@@ -938,6 +939,7 @@ struct ctl_table_header *__register_sysctl_table(
header->unregistering = NULL;
header->root = root;
header->count = 1;
+ header->nreg = 1;
if (sysctl_check_table(path, table))
goto fail;
@@ -1192,6 +1194,20 @@ struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
}
EXPORT_SYMBOL(register_sysctl_table);
+static void drop_sysctl_table(struct ctl_table_header *header)
+{
+ if (--header->nreg)
+ return;
+
+ start_unregistering(header);
+ if (!--header->parent->count) {
+ WARN_ON(1);
+ kfree_rcu(header->parent, rcu);
+ }
+ if (!--header->count)
+ kfree_rcu(header, rcu);
+}
+
/**
* unregister_sysctl_table - unregister a sysctl table hierarchy
* @header: the header returned from register_sysctl_table
@@ -1224,13 +1240,7 @@ void unregister_sysctl_table(struct ctl_table_header * header)
}
spin_lock(&sysctl_lock);
- start_unregistering(header);
- if (!--header->parent->count) {
- WARN_ON(1);
- kfree_rcu(header->parent, rcu);
- }
- if (!--header->count)
- kfree_rcu(header, rcu);
+ drop_sysctl_table(header);
spin_unlock(&sysctl_lock);
}
EXPORT_SYMBOL(unregister_sysctl_table);
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 094bc5c..e40b8f6 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -1032,6 +1032,7 @@ struct ctl_table_header
struct list_head ctl_entry;
int used;
int count;
+ int nreg;
};
struct rcu_head rcu;
};
--
1.7.2.5
next prev parent reply other threads:[~2012-01-27 4:55 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-27 4:45 [Review][PATCH][0/29] sysctl rewrite for speed and clarity Eric W. Biederman
2012-01-27 4:49 ` [PATCH 01/29] sysctl: remove impossible condition check Eric W. Biederman
2012-01-27 4:49 ` [PATCH 02/29] sysctl: Consolidate !CONFIG_SYSCTL handling Eric W. Biederman
2012-01-27 4:49 ` [PATCH 03/29] sysctl: Register the base sysctl table like any other sysctl table Eric W. Biederman
2012-01-27 4:49 ` [PATCH 04/29] sysctl: Move the implementation into fs/proc/proc_sysctl.c Eric W. Biederman
2012-01-27 4:49 ` [PATCH 05/29] sysctl: Make the directories have nlink == 1 Eric W. Biederman
2012-01-27 4:49 ` [PATCH 06/29] sysctl: Implement retire_sysctl_set Eric W. Biederman
2012-01-27 4:49 ` [PATCH 07/29] sysctl: Remove the unnecessary sysctl_set parent concept Eric W. Biederman
2012-01-27 4:49 ` [PATCH 08/29] sysctl: Create local copies of directory names used in paths Eric W. Biederman
2012-01-27 4:49 ` [PATCH 09/29] sysctl: Add support for register sysctl tables with a normal cstring path Eric W. Biederman
2012-01-27 4:49 ` [PATCH 10/29] sysctl: Add ctl_table chains into cstring paths Eric W. Biederman
2012-01-27 4:49 ` [PATCH 11/29] sysctl: register only tables of sysctl files Eric W. Biederman
2012-01-27 4:49 ` [PATCH 12/29] sysctl: Improve the sysctl sanity checks Eric W. Biederman
2012-01-27 4:49 ` [PATCH 13/29] sysctl: Remove the now unused ctl_table parent field Eric W. Biederman
2012-01-27 4:49 ` [PATCH 14/29] sysctl: A more obvious version of grab_header Eric W. Biederman
2012-01-27 4:49 ` [PATCH 15/29] sysctl: Initial support for auto-unregistering sysctl tables Eric W. Biederman
2012-01-27 4:49 ` [PATCH 16/29] sysctl: Factor out init_header from __register_sysctl_paths Eric W. Biederman
2012-01-27 4:49 ` [PATCH 17/29] sysctl: Factor out insert_header and erase_header Eric W. Biederman
2012-01-27 4:49 ` [PATCH 18/29] sysctl: Normalize the root_table data structure Eric W. Biederman
2012-01-27 4:50 ` [PATCH 19/29] sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry Eric W. Biederman
2012-01-27 4:50 ` [PATCH 20/29] sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry Eric W. Biederman
2012-01-27 4:50 ` [PATCH 21/29] sysctl: Add a root pointer to ctl_table_set Eric W. Biederman
2012-01-27 4:50 ` [PATCH 22/29] sysctl: Stop requiring explicit management of sysctl directories Eric W. Biederman
2012-01-27 4:50 ` [PATCH 23/29] sysctl: Add sysctl_print_dir and use it in get_subdir Eric W. Biederman
2012-01-27 4:50 ` [PATCH 24/29] sysctl: Replace root_list with links between sysctl_table_sets Eric W. Biederman
2012-01-27 4:50 ` [PATCH 25/29] sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy Eric W. Biederman
2012-01-27 4:50 ` [PATCH 26/29] sysctl: Move sysctl_check_dups into insert_header Eric W. Biederman
2012-01-27 4:50 ` [PATCH 27/29] sysctl: Make the header lists per directory Eric W. Biederman
2012-01-27 4:50 ` [PATCH 28/29] sysctl: Index sysctl directories with rbtrees Eric W. Biederman
2012-01-27 4:50 ` [PATCH 29/29] sysctl: Add register_sysctl for normal sysctl users Eric W. Biederman
2012-01-27 4:51 ` [PATCH 01/29] sysctl: remove impossible condition check Eric W. Biederman
2012-01-27 4:51 ` [PATCH 02/29] sysctl: Consolidate !CONFIG_SYSCTL handling Eric W. Biederman
2012-01-27 4:51 ` [PATCH 03/29] sysctl: Register the base sysctl table like any other sysctl table Eric W. Biederman
2012-01-27 4:51 ` [PATCH 04/29] sysctl: Move the implementation into fs/proc/proc_sysctl.c Eric W. Biederman
2012-01-27 4:51 ` [PATCH 05/29] sysctl: Make the directories have nlink == 1 Eric W. Biederman
2012-01-27 4:51 ` [PATCH 06/29] sysctl: Implement retire_sysctl_set Eric W. Biederman
2012-01-27 4:51 ` [PATCH 07/29] sysctl: Remove the unnecessary sysctl_set parent concept Eric W. Biederman
2012-01-27 4:51 ` [PATCH 08/29] sysctl: Create local copies of directory names used in paths Eric W. Biederman
2012-01-27 4:51 ` [PATCH 09/29] sysctl: Add support for register sysctl tables with a normal cstring path Eric W. Biederman
2012-01-27 4:51 ` [PATCH 10/29] sysctl: Add ctl_table chains into cstring paths Eric W. Biederman
2012-01-27 4:51 ` [PATCH 11/29] sysctl: register only tables of sysctl files Eric W. Biederman
2012-01-27 4:51 ` [PATCH 12/29] sysctl: Improve the sysctl sanity checks Eric W. Biederman
2012-01-27 4:51 ` [PATCH 13/29] sysctl: Remove the now unused ctl_table parent field Eric W. Biederman
2012-01-27 4:51 ` [PATCH 14/29] sysctl: A more obvious version of grab_header Eric W. Biederman
2012-01-27 4:51 ` Eric W. Biederman [this message]
2012-01-27 4:51 ` [PATCH 16/29] sysctl: Factor out init_header from __register_sysctl_paths Eric W. Biederman
2012-01-27 4:51 ` [PATCH 17/29] sysctl: Factor out insert_header and erase_header Eric W. Biederman
2012-01-27 4:51 ` [PATCH 18/29] sysctl: Normalize the root_table data structure Eric W. Biederman
2012-01-29 17:36 ` Lucian Adrian Grijincu
2012-01-30 0:22 ` Eric W. Biederman
2012-01-27 4:51 ` [PATCH 19/29] sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry Eric W. Biederman
2012-01-29 15:49 ` Lucian Adrian Grijincu
2012-01-27 4:51 ` [PATCH 20/29] sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry Eric W. Biederman
2012-01-27 4:51 ` [PATCH 21/29] sysctl: Add a root pointer to ctl_table_set Eric W. Biederman
2012-01-29 17:19 ` Lucian Adrian Grijincu
2012-01-27 4:51 ` [PATCH 22/29] sysctl: Stop requiring explicit management of sysctl directories Eric W. Biederman
2012-01-29 19:31 ` Lucian Adrian Grijincu
2012-01-31 4:45 ` Eric W. Biederman
2012-01-27 4:51 ` [PATCH 23/29] sysctl: Add sysctl_print_dir and use it in get_subdir Eric W. Biederman
2012-01-27 4:52 ` [PATCH 24/29] sysctl: Replace root_list with links between sysctl_table_sets Eric W. Biederman
2012-01-30 0:01 ` Lucian Adrian Grijincu
2012-01-31 3:10 ` Eric W. Biederman
2012-01-30 17:51 ` Dave Jones
2012-01-31 2:11 ` Eric W. Biederman
2012-01-31 2:13 ` Joe Perches
2012-01-27 4:52 ` [PATCH 25/29] sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy Eric W. Biederman
2012-01-27 4:52 ` [PATCH 26/29] sysctl: Move sysctl_check_dups into insert_header Eric W. Biederman
2012-01-27 4:52 ` [PATCH 27/29] sysctl: Make the header lists per directory Eric W. Biederman
2012-01-27 4:52 ` [PATCH 28/29] sysctl: Index sysctl directories with rbtrees Eric W. Biederman
2012-01-27 4:52 ` [PATCH 29/29] sysctl: Add register_sysctl for normal sysctl users Eric W. Biederman
2012-02-02 3:27 ` [Review][PATCH][0/4] sysctl bitty fixes Eric W. Biederman
2012-02-02 3:28 ` [PATCH 1/4] sysctl: An easier to read version of find_subdir Eric W. Biederman
2012-02-02 3:29 ` [PATCH 2/4] sysctl: Correct error return from get_subdir Eric W. Biederman
2012-02-02 3:29 ` [PATCH 3/4] sysctl: Comments to make the code clearer Eric W. Biederman
2012-02-02 16:28 ` Ben Hutchings
2012-02-02 3:30 ` [PATCH 4/4] sysctl: Don't call sysctl_follow_link unless we are a link Eric W. Biederman
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