[PATCH] sysctl: remove insert_at_head from register_sysctl

The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 3 insertions, 8 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index cb46d0156840..6ccb6cc19e28 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1244,7 +1244,6 @@ int do_sysctl_strategy (ctl_table *table,
 /**
  * register_sysctl_table - register a sysctl hierarchy
  * @table: the top-level table structure
- * @insert_at_head: whether the entry should be inserted in front or at the end
  *
  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
  * array. An entry with a ctl_name of 0 terminates the table. 
@@ -1310,8 +1309,7 @@ int do_sysctl_strategy (ctl_table *table,
  * This routine returns %NULL on a failure to register, and a pointer
  * to the table header on success.
  */
-struct ctl_table_header *register_sysctl_table(ctl_table * table, 
-                                               int insert_at_head)
+struct ctl_table_header *register_sysctl_table(ctl_table * table)
 {
         struct ctl_table_header *tmp;
         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
@@ -1322,10 +1320,7 @@ struct ctl_table_header *register_sysctl_table(ctl_table * table,
         tmp->used = 0;
         tmp->unregistering = NULL;
         spin_lock(&sysctl_lock);
-        if (insert_at_head)
-                list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
-        else
-                list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
+        list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
         spin_unlock(&sysctl_lock);
 #ifdef CONFIG_PROC_SYSCTL
         register_proc_table(table, proc_sys_root, tmp);
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 324aa1341b5f..f22b9dbd2a9c 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -139,7 +139,7 @@ static struct ctl_table uts_root_table[] = {
 
 static int __init utsname_sysctl_init(void)
 {
-        register_sysctl_table(uts_root_table, 0);
+        register_sysctl_table(uts_root_table);
         return 0;
 }