Walking the btree can trigger a number of single block synchronous reads.
This patch does btree readahead during operations that are likely to be long
and sequential.  So far, that only includes directory reads and truncates, but
it can make both much faster.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove debugging warning from the reiserfs block allocator code
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

reiserfsck --rebuild-tree expects the only key with a packing locality of 1 to
be for the root directory (key [1 2]).  The new block allocator inherited that
packing locality down to subdirectories, which triggers failures in reiserfsck
--rebuild-tree

reiserfsck in readonly check mode doesn't complain about this, thanks to Jeff
Mahoney for finding it.

The fix is to never inherit packing locality #1
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

From: <mason@suse.com>
From: <jeffm@suse.com>

The current reiserfs allocator pretty much allocates things sequentially
from the start of the disk, it works very nicely for desktop loads but
once you've got more then one proc doing io data files can fragment badly.

One obvious solution is something like ext2's bitmap groups, which puts
file data into different areas of the disk based on which subdirectory
they are in.  The problem with bitmap groups is that if you've got a
group of subdirectories their contents will be spread out all over the
disk, leading to lots of seeks during a sequential read.

This allocator patch uses the packing locality to determine which bitmap
group to allocate from, but when you create a file it looks in the bitmaps
to see how 'full' that packing locality already is.  If it hasn't been
heavily used yet, the packing locality is inherited from the parent
directory putting files in new subdirs close to the parent subdir,
otherwise it is the inode number of the parent directory putting new
files far away from the parent subdir.

The end result is fewer bitmap groups for the same working set.  For
example, one test data set created by 20 procs running in parallel has
6822 subdirs.  And with vanilla reiserfs that would mean 6822
packing localities.  This patch turns that into 26 packing localities.

This makes sequential reads of big directory trees more efficient, but
it also makes the btree more efficient in general.  Things end up sorted
better because groups of subdirs end up with similar keys in the btree,
instead of being spread out all over.

The bitmap grouping code tries to use the start of each bitmap group
for metadata, and offsets the data slightly.  The data and metadata
are still close together, but not completely intermixed like they are
in the default allocator.  The end result is that leaf nodes tend to be
close to each other, making metadata readahead more effective.

The old block allocator had the ability to enforce a minimum
allocation size, but did not use it.  It now tries to do a pass looking
for larger allocation chunks before falling back to the old behaviour
of taking any blocks it can find.

The patch changes the defaults to:

mount -o alloc=skip_busy:dirid_groups:packing_groups

You can get back the old behaviour with mount -o alloc=skip_busy

mount -o alloc=dirid_groups will turn on the bitmap groups
mount -o alloc=packing_groups turns on the packing locality reduction code
mount -o alloc=skip_busy:dirid_groups turns on both dirid_groups and
skip_busy

Finally the patch adds a mount -o alloc=oid_groups, which puts files into
bitmap groups based on a hash of their objectid.  This would be used for
databases or other situations where you have a limited number of very
large files.

This command will tell you how many packing localities are actually in
use:

debugreiserfs -d /dev/xxx | grep '^|.*SD' | sed 's/^.....//' | awk '{print $1}' | sort -u | wc -l
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The pgalloc.h changes broke ppc64:

In file included from include/asm-generic/tlb.h:18,
                 from include/asm/tlb.h:24,
                 from arch/ppc64/mm/hash_utils.c:48:
include/asm/pgalloc.h: In function `__pte_free_tlb':
include/asm/pgalloc.h:110: dereferencing pointer to incomplete type
include/asm/pgalloc.h:111: dereferencing pointer to incomplete type

Uninlining __pte_free_tlb() fixes that.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch cleans up needless includes of asm/pgalloc.h from the arch/i386/
subtree.  Compile tested on x86_pc SMP.

[I also tried VISWS + SMP without PM doesn't build in smpboot.c,
 though I don't believe its caused by this patch.  With PM, fails
 to link complaining maxcpus is undefined.  Therefore, I presume
 VISWS + SMP is an invalid configuration.]

This patch is part of a larger patch aiming towards getting the include of
asm/pgtable.h out of linux/mm.h, so that asm/pgtable.h can sanely get at
things like mm_struct and friends.

I suggest testing in -mm for a while to ensure there aren't any hidden arch
issues.

The outstanding list of files for other architectures can be found
at http://www.arm.linux.org.uk/misc/pgalloc.txtSigned-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch cleans up needless includes of asm/pgalloc.h from the drivers/
subtree.  drivers/char/mem.c has been compile tested; the others have not,
since they are for non-x86 and non-ARM architectures.

This patch is part of a larger patch aiming towards getting the include of
asm/pgtable.h out of linux/mm.h, so that asm/pgtable.h can sanely get at
things like mm_struct and friends.

I suggest testing in -mm for a while to ensure there aren't any hidden arch
issues.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch cleans up needless includes of asm/pgalloc.h from the fs/
kernel/ and mm/ subtrees.  Compile tested on multiple ARM platforms, and
x86, this patch appears safe.

This patch is part of a larger patch aiming towards getting the include of
asm/pgtable.h out of linux/mm.h, so that asm/pgtable.h can sanely get at
things like mm_struct and friends.

I suggest testing in -mm for a while to ensure there aren't any hidden arch
issues.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch allows for misc binaries to run with credentials and security
token that are calculated according to the binaries, and not according to the
interpreter, which is the legacy behavior of binfmt_misc.

The way it is done is by calling prepare_binprm, which is where these
attributes are calculated, before switching the 'file' field in the bprm from
the binary to the interpreter.

This feature should be used with care, since the interpreter will have root
permissions when running a setuid binary owned by root.

Please note -

- Only root can register an interpreter with binfmt_misc.  The feature is
  documented and the administrator is advised to handle it with care

- The new feature is enabled only with a special flag in the registration
  string.  When this flag is not specified the current behavior of
  binfmt_misc is kept

- This is the only 'right' way for an interpreter to know the correct
  AT_SECURE value for the interpreted binary


From: Chris Wright <chrisw@osdl.org>

  This patchset looks OK, except for one problem.  It installs the fd (which
  could've been unreadable) without unsharing the ->files.  So someone can use
  this to read unreadable yet executable files.  Here's a patch which fixes
  that up.  I added one bit that's commented out because I'm not positive if a
  final steal_locks() is needed.

  I did a fair amount of rearranging to simplify the error conditions
  relative to the fd_install(), and unshare_files().

From: Chris Wright <chrisw@osdl.org>

  I found that the intel patchset (and mine as well) leaked i_writecount on
  the original executed file.  In addition, I verified that the steal_locks()
  bit is indeed needed.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

<background>

I work in a group that works on enabling the IA-32 Execution Layer
(http://www.intel.com/pressroom/archive/releases/20040113comp.htm) on Linux.
In a few words - this is a dynamic translator for IA-32 binaries on IPF
platform.  Following David Mosberger's advice - we use the binfmt_misc
mechanism for the invocation of the translator whenever the user tries to
exec an IA-32 binary.

The EL is meant to help in the migration path from IA-32 to IPF.  From our
beta customers we learnt that at first stage - they tend to keep their
environment mostly intact, using the legacy IA-32 binaries.

Such an environment has, naturally, setuid and non-readable binaries.  It
will be useless to ask the administrator to change the settings of such an
environment - some of them are very complex, and the administrators are
reluctant to make any changes in a system that already proved itself to be
robust and secure.  So, our target with these patches is not to enhance the
support for scripts but rather to allow a translator to be integrated into a
working environment that is not (and should not be) aware to the fact it's
being emulated.

As I said before - it is practically hopeless to expect an administrator of
such a system to change it so that it will suit the current behavior of
binfmt_misc.  But, even if we could do that,

I'm not sure it would be a good idea - these changes are likely to be less
secure than the suggested patches -

- In order to execute non-readable binaries the binary will have to be made
  readable, which is obviously less secure than allowing only a trusted
  translator to read it

- There will be no way for the translator to calculate the accurate
  AT_SECURE value for the translated process.  This might end up with the
  translated process running in a non-secured mode when it actually needs to
  be secured.

</background>


I prepared a patch that solves a couple of problems that interpreters have
when invoked via binfmt_misc.  currently -

1) such interpreters cannot open non-readable binaries

2) the processes will have their credentials and security attributes
   calculated according to interpreter permissions and not those of the
   original binary

the proposed patch solves these problems by -

1) opening the binary on behalf of the interpreter and passing its fd
   instead of the path as argv[1] to the interpreter

2) calling prepare_binprm with the file struct of the binary and not the
   one of the interpreter

The new functionality is enabled by adding a special flag to the registration
string.  If this flag is not added then old behavior is not changed.

A preliminary version of this patch was sent to the list on 9/1/2003 with the
title "[PATCH]: non-readable binaries - binfmt_misc 2.6.0-test4".  This new
version fixes the concerns that were raised by the patch, except of calling
unshare_files() before allocating a new fd.  this is because this feature did
not enter 2.6 yet.


Arun Sharma <arun.sharma@intel.com> says:

We were going through an internal review of this patch:

http://marc.theaimsgroup.com/?l=linux-kernel&m=107424598901720&w=2

which is in your tree already.  I'm not sure if this line of code got
sufficient review.

+               /* call prepare_binprm before switching to interpreter's file
+                * so that all security calculation will be done according to
+                * binary and not interpreter */
+               retval = prepare_binprm(bprm);

The case that concerns me is: unprivileged interpreter and a privileged
binary.  One can use binfmt_misc to execute untrusted code (interpreter) with
elevated privileges.  One could argue that all binfmt_misc interpreters are
trusted, because only root can register them.  But that's a change from the
traditional behavior of binfmt_misc (and binfmt_script).


(Update):

Arun pointed out that calculating the process credentials according to the
binary that needs to be translated is a bit risky, since it requires the
administrator to pay extra attention not to register an interpreter which is
not intended to run with root credentials.

After discussing this issue with him, I would like to propose a modified
patch: The old patch did 2 things - 1) open the binary for reading and 2)
calculate the credentials according to the binary.

I removed the riskier part of changing the credentials calculation, so the
revised patch only opens the binary for reading.  It also includes few words
of warning in the description of the 'open-binary' feature in
binfmt_misc.txt, and makes the function entry_status print the flags in use.

As for the 'credentials' part of the patch, I will prepare a separate patch
for it and send it again to the LKML, describe the problem and ask for people
comments.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add myself as the PPC4xx maintainer. Merge CREDITS entry from 2.4
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

/proc/cmdline is filled via an OS400 call iSeries_init().  It scans the
returned data from the end, instead of the beginning.  This leads to
multiple lines in /proc/cmdline

Just scan from the beginning and stop at the first newline.  This patch
changes also the /proc/iSeries/mf/*/cmdline interface to do the same as the
initial setup.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2.6.7-rc3-mm1 changed cpumask_t from ulong to a struct, causing
compile-time errors in arch/ppc/kernel/irq.c.

Proposed fix below. Tested on a G3.
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Here is both a GNU style and BK patch for adding support for the e500 core and
85xx platform to 2.6.  This is pretty much a direct port from 2.4 with a bit
of cleanup around the edges.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Test for pte_young before going to the costlier atomic test_and_clear, as
asm-generic does.  Test for pte_dirty before going to the costlier atomic
test_and_clear, as asm-generic does (I said before that I would not do so for
pte_dirty, but was missing the point: there is nothing atomic about deciding
to do nothing).  But I've not touched the rather different ppc and ppc64.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Traditionally we've not flushed TLB after clearing the young/referenced bit,
it has seemed just a waste of time.  Russell King points out that on some
architectures, with the move from 2.4 mm sweeping to 2.6 rmap, this may be a
serious omission: very frequently referenced pages never re-marked young, and
the worst choices made for unmapping.

So, replace ptep_test_and_clear_young by ptep_clear_flush_young throughout
rmap.c.  Originally I'd imagined making some kind of TLB gather optimization,
but don't see what now: whether worth it rather depends on how common
cross-cpu flushes are, and whether global or not.

ppc and ppc64 have already found this issue, and worked around it by arranging
TLB flush from their ptep_test_and_clear_young: with the aid of pgtable rmap
pointers.  I'm hoping ptep_clear_flush_young will allow ppc and ppc64 to
remove that special code, but won't change them myself.

It's worth noting that it is Andrea's anon_vma rmap which makes the vma
available for ptep_clear_flush_young in page_referenced_one: anonmm and
pte_chains would both need an additional find_vma for that.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

Compilation fails due to incorrect usage of NODE_DATA().

Reported by hpa.

This rewrites the PPC64 exception entry/exit routines to make them
smaller and faster.

In particular we no longer save all of the registers for the common
exceptions - system calls, hardware interrupts and decrementer (timer)
interrupts - only the volatile registers.  The other registers are saved
and restored (if used) by the C functions we call.  This involved
changing the registers we use in early exception processing from r20-r23
to r9-r12, which ended up changing quite a lot of code in head.S. 
Overall this gives us about a 20% reduction in null syscall time. 

Some system calls need all the registers (e.g.  fork/clone/vfork and
[rt_]sigsuspend).  For these the syscall dispatch code calls a stub that
saves the nonvolatile registers before calling the real handler.

This also implements the force_successful_syscall_return() thing for
ppc64.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This implements CONFIG_PREEMPT for ppc64.  Aside from the entry.S
changes to check the _TIF_NEED_RESCHED bit when returning from an
exception, there are various changes to make the ppc64-specific code
preempt-safe, mostly adding preempt_enable/disable or get_cpu/put_cpu
calls where needed.  I have been using this on my desktop G5 for the
last week without problems.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

into kernel.bkbits.net:/home/davem/sparc-2.6

I noticed that insert_resource() incorrectly handles the case of an
existing parent resource with the same ending address as a newly added
child.  This results in incorrect nesting, like the following:

	# cat /proc/ioports
	<snip>
	002f0000-002fffff : PCI Bus #48
	  00200000-002fffff : /pci@800000020000003
	</snip>
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Make sure that number of sectors != 0 for in/out command before sending
it to drive.  Remove no longer needed checks from flagged_* PIO handlers.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

PIO handlers under CONFIG_IDE_TASKFILE_IO=n are never used for bio
based requests (rq->bio is always NULL) so we can use rq->buffer
directly instead of calling ide_[un]map_buffer().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

- merge status checking code for rq->current_nr_sectors
  and !rq->current_nr_sectors cases
- remove !rq->bio check as it is always true
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

These handlers are nowadays used only for REQ_DRIVE_TASKFILE
requests (rq->bio is always NULL) which aren't retried et all so
remove code 'rewinding' rq->current_nr_sectors and some FIXMEs.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

If REQ_DRIVE_* request fails ide_end_drive_cmd() should be called
for it not ->end_request().  This was broken by 2.6.5, fix it.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

'cat /proc/ide/hdx/identify' generates REQ_DRIVE_TASKFILE request
(for WIN_PIDENTIFY command) even for devices controlled by ide-cd.
All other drivers don't try to retry such requests.

Acked by Jens.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

First introduced in 2.4.19/2.5.3 as ALTSTAT_SCREW_UP, never used.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

- do not unregister ide-pnp driver while detaching random
  IDE device from random IDE device driver if IDE is modular
  (somebody added this in 2.3.51)
- clear 'hw_regs_t hw' allocated from stack
- mark idepnp_init() with __init
- use ide_std_init_ports() instead of ide_setup_ports()
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

From: Geert Uytterhoeven <geert@linux-m68k.org>

The IDE sparse fixups cause 2 warnings (unused variables `val' and
`reg') on m68k and APUS.  However, the reason why this code was
commented out is gone.  So just remove the special case.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

They are only included from these drivers.

While at it:
- remove redundant ide_pci_device_t tables
- add DECLARE_CS_DEV() (cs5520)
- remove duplicate DISPLAY_SC1200_TIMINGS define (sc1200)
- remove unused SIIMAGE_BUFFERED_TASKFILE, SII_DEBUG
  and siiprintk() defines + add DECLARE_SII_DEV() (siimage)
- remove unused SLC90E66_DEBUG_DRIVE_INFO define (slc90e66)
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Extracted from the Debian kernel package
(original patch is from Herbert Xu).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

into ppc970.osdl.org:/home/torvalds/v2.6/linux

into ppc970.osdl.org:/home/torvalds/v2.6/linux

Thanks to Ivan Kokshaysky for spotting this.

into ppc970.osdl.org:/home/torvalds/v2.6/linux

into ppc970.osdl.org:/home/torvalds/v2.6/linux