With this change the sysctl inodes can be cached and nothing needs to be done
when removing a sysctl table.

For a cost of 2K code we will save about 4K of static tables (when we remove
de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or
about half that on a 32bit arch.

The speed feels about the same, even though we can now cache the sysctl
dentries :(

We get the core advantage that we don't need to have a 1 to 1 mapping between
ctl table entries and proc files.  Making it possible to have /proc/sys vary
depending on the namespace you are in.  The currently merged namespaces don't
have an issue here but the network namespace under /proc/sys/net needs to have
different directories depending on which network adapters are visible.  By
simply being a cache different directories being visible depending on who you
are is trivial to implement.

[akpm@osdl.org: fix uninitialised var]
[akpm@osdl.org: fix ARM build]
[bunk@stusta.de: make things static]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current logic to walk through the list of sysctl table headers is slightly
painful and implement in a way it cannot be used by code outside sysctl.c

I am in the process of implementing a version of the sysctl proc support that
instead of using the proc generic non-caching monster, just uses the existing
sysctl data structure as backing store for building the dcache entries and for
doing directory reads.  To use the existing data structures however I need a
way to get at them.

[akpm@osdl.org: warning fix]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NMartin 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

parse_table has support for calling a strategy routine when descending into a
directory.  To date no one has used this functionality and the /proc/sys
interface has no analog to it.

So no one is using this functionality kill it and make the binary sysctl code
easier to follow.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are currently no users in the kernel for CTL_ANY and it only has effect
on the binary interface which is practically unused.

So this complicates sysctl lookups for no good reason so just remove it.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

binfmt_misc has a mount point in the middle of the sysctl and that mount point
is created as a proc_generic directory.

Doing it that way gets in the way of cleaning up the sysctl proc support as it
continues the existence of a horrible hack.  So instead simply create the
directory as an ordinary sysctl directory.  At least that removes the magic
special case.

[akpm@osdl.org: warning fix]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is just a simple cleanup to keep kernel/sysctl.c from getting to crowded
with special cases, and by keeping all of the ipc logic to together it makes
the code a little more readable.

[gcoady.lk@gmail.com: build fix]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: NGrant Coady <gcoady.lk@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is just a simple cleanup to keep kernel/sysctl.c from getting to crowded
with special cases, and by keeping all of the utsname logic to together it
makes the code a little more readable.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ocfs2 was did not have the binary number it uses under CTL_FS registered in
sysctl.h.  Register it to avoid future conflicts, and change the name of the
definition to be in line with the rest of the sysctl numbers.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NMark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Putting ntfs-debug under FS_NRINODE was not a kosher thing to do so don't give
it any binary number.

[akpm@osdl.org: build fix]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Will converting the coda sysctl initializers I discovered that it is yet
another user of sysctl that was stomping CTL_KERN.  So off with it's
sys_sysctl support since it wasn't done in a supportable way.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The real time clock driver was using the binary number reserved for cdroms in
the sysctl binary number interface, which is a no-no.  So since the sysctl
binary interface is wrong remove it.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the binary sysctl interface the hpet driver was claiming to be the cdrom
driver.  This is a no-no so remove support for the binary interface.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Basically everything was done but I removed all element initializers from the
trailing entries to make it clear the entire last entry should be zero filled.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The only sysctl x86_64 provides are not provided elsewhere, so insert_at_head
is unnecessary.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While doing the C99 conversion I notices that the top level sh64 directory was
using the binary number for CTL_KERN.  That is a no-no so I removed the
support for the sysctl binary interface only leaving sysctl /proc support.

At least the sysctl tables were placed at the end of the list so user space
did not see this mistake.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

And make the mode of the kernel directory 0555 no one is allowed to write to
sysctl directories.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This was partially done already and there was no ABI breakage what a relief.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We need to have the the definition of all top level sysctl directories
registers in sysctl.h so we don't conflict by accident and cause abi problems.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While C99 converting the ctl_table initializers I realized that the binary
sysctl numbers were in conflict with the binary values under CTL_KERN.
Including CTL_KERN KERN_VERSION as used by glibc.  So I just removed the
sysctl binary interface for these values, as it was unsupportable.

Luckily these sysctl were inserted at the end of the sysctl list so this bug
was not visible to userspace.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The assignment of binary numbers for sys_sysctl use was in shambles and
despite requiring methods.  Nothing was implemented on the sys_sysctl side.

So this patch gives a mercy killing to the sys_sysctl support for
powermanagment on mips/au1000.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This convters the sysctl ctl_tables to use C99 initializers.  While I was
looking at it I discovered it was using a portion of the sysctl binary
addresses space under CTL_KERN KERN_OSTYPE which was completely inappropriate.
 So I completely removed all of the sysctl binary names, to remove and avoid
the ABI conflict.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

By not using the enumeration in sysctl.h (or even understanding it) the SN
platform placed their arch specific xpc directory on top of CTL_KERN and only
because they didn't have 4 entries in their xpc directory got lucky and didn't
break glibc.

This is totally irresponsible.  So this patch entirely removes sys_sysctl
support from their sysctl code.  Hopefully they don't have ascii name
conflicts as well.

And now that they have no ABI numbers add them to the end instead of the
sysctl list instead of the head so nothing else will be overridden.

Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since the binary sysctl numbers are unique putting the registered sysctls at
the head of the sysctl list where they can override existing sysctls serves no
useful purpose.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With unique binary numbers setting insert_at_head to insert yourself at the
head of sysctl list and thus override existing sysctl entries serves no point.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no need for open files in /proc/sys/XXX to hold a reference count on
the module that provides the file to prevent module unload races.  While there
is code active in the module p->used in the sysctl_table_header is
incremented, preventing the sysctl from being unregisted.  Once the sysctl is
unregistered it cannot be found.  Open files are also not a problem as they
revalidate the sysctl information and bump p->used before accessing module
code.

So setting de->owner is unnecessary, makes for a bad example and gets in my
way of removing ctl_table->de.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NJens Axboe <jens.axboe@oracle.com>
Acked-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With unique binary sysctl numbers setting insert_at_head to override other
sysctl entries is pointless.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>