Scheduler hooks to see/change which process is deemed to be on a cpu.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove these ifdefs - there's no need to have more than one definition of
these multipliers anywhere.

Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clarify the human-time units to jiffies conversion functions by using the
constants in time.h.  This makes many of the subsequent patches direct
copies of the current code.
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add schedule_timeout_{,un}interruptible() interfaces so that
schedule_timeout() callers don't have to worry about forgetting to add the
set_current_state() call beforehand.
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

"extern inline" doesn't make much sense.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

"extern inline" doesn't make much sense.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

"extern inline" doesn't make much sense.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: NVictor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: NDomen Puncer <domen@coderock.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: NVictor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: NDomen Puncer <domen@coderock.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: NVictor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: NDomen Puncer <domen@coderock.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With Nick Piggin <npiggin@suse.de>

Give some things static scope.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch implements a task state bit (TASK_NONINTERACTIVE), which can be
used by blocking points to mark the task's wait as "non-interactive".  This
does not mean the task will be considered a CPU-hog - the wait will simply
not have an effect on the waiting task's priority - positive or negative
alike.  Right now only pipe_wait() will make use of it, because it's a
common source of not-so-interactive waits (kernel compilation jobs, etc.).
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The cpusets-formalize-intermediate-gfp_kernel-containment patch
has a deadlock problem.

This patch was part of a set of four patches to make more
extensive use of the cpuset 'mem_exclusive' attribute to
manage kernel GFP_KERNEL memory allocations and to constrain
the out-of-memory (oom) killer.

A task that is changing cpusets in particular ways on a system
when it is very short of free memory could double trip over
the global cpuset_sem semaphore (get the lock and then deadlock
trying to get it again).

The second attempt to get cpuset_sem would be in the routine
cpuset_zone_allowed().  This was discovered by code inspection.
I can not reproduce the problem except with an artifically
hacked kernel and a specialized stress test.

In real life you cannot hit this unless you are manipulating
cpusets, and are very unlikely to hit it unless you are rapidly
modifying cpusets on a memory tight system.  Even then it would
be a rare occurence.

If you did hit it, the task double tripping over cpuset_sem
would deadlock in the kernel, and any other task also trying
to manipulate cpusets would deadlock there too, on cpuset_sem.
Your batch manager would be wedged solid (if it was cpuset
savvy), but classic Unix shells and utilities would work well
enough to reboot the system.

The unusual condition that led to this bug is that unlike most
semaphores, cpuset_sem _can_ be acquired while in the page
allocation code, when __alloc_pages() calls cpuset_zone_allowed.
So it easy to mistakenly perform the following sequence:
  1) task makes system call to alter a cpuset
  2) take cpuset_sem
  3) try to allocate memory
  4) memory allocator, via cpuset_zone_allowed, trys to take cpuset_sem
  5) deadlock

The reason that this is not a serious bug for most users
is that almost all calls to allocate memory don't require
taking cpuset_sem.  Only some code paths off the beaten
track require taking cpuset_sem -- which is good.  Taking
a global semaphore on the main code path for allocating
memory would not scale well.

This patch fixes this deadlock by wrapping the up() and down()
calls on cpuset_sem in kernel/cpuset.c with code that tracks
the nesting depth of the current task on that semaphore, and
only does the real down() if the task doesn't hold the lock
already, and only does the real up() if the nesting depth
(number of unmatched downs) is exactly one.

The previous required use of refresh_mems(), anytime that
the cpuset_sem semaphore was acquired and the code executed
while holding that semaphore might try to allocate memory, is
no longer required.  Two refresh_mems() calls were removed
thanks to this.  This is a good change, as failing to get
all the necessary refresh_mems() calls placed was a primary
source of bugs in this cpuset code.  The only remaining call
to refresh_mems() is made while doing a memory allocation,
if certain task memory placement data needs to be updated
from its cpuset, due to the cpuset having been changed behind
the tasks back.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch (written by me and also containing many suggestions of Arjan van
de Ven) does a major cleanup of the spinlock code.  It does the following
things:

 - consolidates and enhances the spinlock/rwlock debugging code

 - simplifies the asm/spinlock.h files

 - encapsulates the raw spinlock type and moves generic spinlock
   features (such as ->break_lock) into the generic code.

 - cleans up the spinlock code hierarchy to get rid of the spaghetti.

Most notably there's now only a single variant of the debugging code,
located in lib/spinlock_debug.c.  (previously we had one SMP debugging
variant per architecture, plus a separate generic one for UP builds)

Also, i've enhanced the rwlock debugging facility, it will now track
write-owners.  There is new spinlock-owner/CPU-tracking on SMP builds too.
All locks have lockup detection now, which will work for both soft and hard
spin/rwlock lockups.

The arch-level include files now only contain the minimally necessary
subset of the spinlock code - all the rest that can be generalized now
lives in the generic headers:

 include/asm-i386/spinlock_types.h       |   16
 include/asm-x86_64/spinlock_types.h     |   16

I have also split up the various spinlock variants into separate files,
making it easier to see which does what. The new layout is:

   SMP                         |  UP
   ----------------------------|-----------------------------------
   asm/spinlock_types_smp.h    |  linux/spinlock_types_up.h
   linux/spinlock_types.h      |  linux/spinlock_types.h
   asm/spinlock_smp.h          |  linux/spinlock_up.h
   linux/spinlock_api_smp.h    |  linux/spinlock_api_up.h
   linux/spinlock.h            |  linux/spinlock.h

/*
 * here's the role of the various spinlock/rwlock related include files:
 *
 * on SMP builds:
 *
 *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
 *                        initializers
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
 *                        implementations, mostly inline assembly code
 *
 *   (also included on UP-debug builds:)
 *
 *  linux/spinlock_api_smp.h:
 *                        contains the prototypes for the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 *
 * on UP builds:
 *
 *  linux/spinlock_type_up.h:
 *                        contains the generic, simplified UP spinlock type.
 *                        (which is an empty structure on non-debug builds)
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  linux/spinlock_up.h:
 *                        contains the __raw_spin_*()/etc. version of UP
 *                        builds. (which are NOPs on non-debug, non-preempt
 *                        builds)
 *
 *   (included on UP-non-debug builds:)
 *
 *  linux/spinlock_api_up.h:
 *                        builds the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 */

All SMP and UP architectures are converted by this patch.

arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers.  m32r, mips, sh, sparc, have not been tested yet, but should
be mostly fine.

From: Grant Grundler <grundler@parisc-linux.org>

  Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
  Builds 32-bit SMP kernel (not booted or tested).  I did not try to build
  non-SMP kernels.  That should be trivial to fix up later if necessary.

  I converted bit ops atomic_hash lock to raw_spinlock_t.  Doing so avoids
  some ugly nesting of linux/*.h and asm/*.h files.  Those particular locks
  are well tested and contained entirely inside arch specific code.  I do NOT
  expect any new issues to arise with them.

 If someone does ever need to use debug/metrics with them, then they will
  need to unravel this hairball between spinlocks, atomic ops, and bit ops
  that exist only because parisc has exactly one atomic instruction: LDCW
  (load and clear word).

From: "Luck, Tony" <tony.luck@intel.com>

   ia64 fix
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjanv@infradead.org>
Signed-off-by: NGrant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: NHirokazu Takata <takata@linux-m32r.org>
Signed-off-by: NMikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: NBenoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To avoid future conflicts, add a note values allocated for ip6_tables.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

64, 65 are already used in ip6_tables.
Pointed out by Patrick McHardy <kaber@trash.net>.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Most awkward part of this is delaying write requests until bitmap updates have
been flushed.

To achieve this, we have a sequence number (seq_flush) which is incremented
each time the raid5 is unplugged.

If the raid thread notices that this has changed, it flushes bitmap changes,
and assigned the value of seq_flush to seq_write.

When a write request arrives, it is given the number from seq_write, and that
write request may not complete until seq_flush is larger than the saved seq
number.

We have a new queue for storing stripes which are waiting for a bitmap flush
and an extra flag for stripes to record if the write was 'degraded' and so
should not clear the a bit in the bitmap.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

version-1 superblocks are not (normally) 4K long, and can be of variable size.
 Writing the full 4K can cause corruption (but only in non-default
configurations).

With this patch the super-block-flavour can choose a size to read, and set a
size to write based on what it finds.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

These inlines haven't been used for ages, they should go.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As this is used to flag an internal bitmap.

Also, introduce symbolic names for feature bits.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

linear currently uses division by the size of the smallest componenet device
to find which device a request goes to.  If that smallest device is larger
than 2 terabytes, then the division will not work on some systems.

So we introduce a pre-shift, and take care not to make the hash table too
large, much like the code in raid0.

Also get rid of conf->nr_zones, which is not needed.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If a device is flagged 'WriteMostly' and the array has a bitmap, and the
bitmap superblock indicates that write_behind is allowed, then write_behind is
enabled for WriteMostly devices.

Write requests will be acknowledges as complete to the caller (via b_end_io)
when all non-WriteMostly devices have completed the write, but will not be
cleared from the bitmap until all devices complete.

This requires memory allocation to make a local copy of the data being
written.  If there is insufficient memory, then we fall-back on normal write
semantics.
Signed-Off-By: NPaul Clements <paul.clements@steeleye.com>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This allows a device in a raid1 to be marked as "write mostly".  Read requests
will only be sent if there is no other option.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Both file-bitmaps and superblock bitmaps are supported.

If you add a bitmap file on the array device, you lose.

This introduces a 'default_bitmap_offset' field in mddev, as the ioctl used
for adding a superblock bitmap doesn't have room for giving an offset.  Later,
this value will be setable via sysfs.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Don't just irritate all other kernel developers.  Fix the users first,
then you can re-introduce the must-check infrastructure to avoid new
cases creeping in.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up timer initialization by introducing DEFINE_TIMER a'la
DEFINE_SPINLOCK.  Build and boot-tested on x86.  A similar patch has been
been in the -RT tree for some time.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds a new FSYNCDIR request, which is sent when fsync is called
on directories.  This operation is available in libfuse 2.3-pre1 or
greater.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make data caching behavior selectable on a per-open basis instead of
per-mount.  Compatibility for the old mount options 'kernel_cache' and
'direct_io' is retained in the userspace library (version 2.4.0-pre1 or
later).
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch removes a long lasting "hack" in FUSE, which used a separate
channel (a file descriptor refering to a disk-file) to transfer directory
contents from userspace to the kernel.

The patch adds three new operations (OPENDIR, READDIR, RELEASEDIR), which
have semantics and implementation exactly maching the respective file
operations (OPEN, READ, RELEASE).

This simplifies the directory reading code.  Also disk space is not
necessary, which can be important in embedded systems.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add padding to structures to make sizes the same on 32bit and 64bit archs.
Initial testing and test machine generously provided by Franco Broi.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds the extended attribute operations to FUSE.

The following operations are added:

 o getxattr
 o setxattr
 o listxattr
 o removexattr
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds the file operations of FUSE.

The following operations are added:

 o open
 o flush
 o release
 o fsync
 o readpage
 o commit_write
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds the write filesystem operations of FUSE.

The following operations are added:

 o setattr
 o symlink
 o mknod
 o mkdir
 o create
 o unlink
 o rmdir
 o rename
 o link
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds the read-only filesystem operations of FUSE.

This contains the following files:

 o dir.c
    - directory, symlink and file-inode operations

The following operations are added:

 o lookup
 o getattr
 o readlink
 o follow_link
 o directory open
 o readdir
 o directory release
 o permission
 o dentry revalidate
 o statfs
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds the FUSE device handling functions.

This contains the following files:

 o dev.c
    - fuse device operations (read, write, release, poll)
    - registers misc device
    - support for sending requests to userspace
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds FUSE core.

This contains the following files:

 o inode.c
    - superblock operations (alloc_inode, destroy_inode, read_inode,
      clear_inode, put_super, show_options)
    - registers FUSE filesystem

 o fuse_i.h
    - private header file

Requirements
============

 The most important difference between orinary filesystems and FUSE is
 the fact, that the filesystem data/metadata is provided by a userspace
 process run with the privileges of the mount "owner" instead of the
 kernel, or some remote entity usually running with elevated
 privileges.

 The security implication of this is that a non-privileged user must
 not be able to use this capability to compromise the system.  Obvious
 requirements arising from this are:

  - mount owner should not be able to get elevated privileges with the
    help of the mounted filesystem

  - mount owner should not be able to induce undesired behavior in
    other users' or the super user's processes

  - mount owner should not get illegitimate access to information from
    other users' and the super user's processes

 These are currently ensured with the following constraints:

  1) mount is only allowed to directory or file which the mount owner
    can modify without limitation (write access + no sticky bit for
    directories)

  2) nosuid,nodev mount options are forced

  3) any process running with fsuid different from the owner is denied
     all access to the filesystem

 1) and 2) are ensured by the "fusermount" mount utility which is a
    setuid root application doing the actual mount operation.

 3) is ensured by a check in the permission() method in kernel

 I started thinking about doing 3) in a different way because Christoph
 H. made a big deal out of it, saying that FUSE is unacceptable into
 mainline in this form.

 The suggested use of private namespaces would be OK, but in their
 current form have many limitations that make their use impractical (as
 discussed in this thread).

 Suggested improvements that would address these limitations:

   - implement shared subtrees

   - allow a process to join an existing namespace (make namespaces
     first-class objects)

   - implement the namespace creation/joining in a PAM module

 With all that in place the check of owner against current->fsuid may
 be removed from the FUSE kernel module, without compromising the
 security requirements.

 Suid programs still interesting questions, since they get access even
 to the private namespace causing some information leak (exact
 order/timing of filesystem operations performed), giving some
 ptrace-like capabilities to unprivileged users.  BTW this problem is
 not strictly limited to the namespace approach, since suid programs
 setting fsuid and accessing users' files will succeed with the current
 approach too.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The function bit_putcs() in drivers/video/console/bitblit.c is becoming large.
 Break it up into its component functions (bit_putcs_unaligned and
bit_putcs_aligned).

Incorporated fb_pad_aligned_buffer() optimization by Roman Zippel.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The Coordinated Video Timings (CVT) is the latest standard approved by VESA
concerning video timings generation.  It addresses the limitation of GTF which
is designed mainly for CRT displays.  CRT's have a high blanking requirement
(as much as 25% of the horizontal frame length) which artificially increases
the pixelclock.  Digital displays, on the other hand, needs to conserve the
pixelclock as much as possible.  The GTF also does not take into account the
different aspect ratios in its calculation.

The new function added is fb_find_mode_cvt().  It is called by fb_find_mode()
if it recognizes a mode option string formatted for CVT.  The format is:

<xres>x<yres>[M][R][-<bpp>][<at-sign><refresh>][i][m]

The 'M' tells the function to calculate using CVT.  On it's own, it will
compute a timing for CRT displays at 60Hz.  If the 'R' is specified, 'reduced
blanking' computation will be used, best for flatpanels.  The 'i' and the 'm'
is for 'interlaced mode' and 'with margins' respectively.

To determine if CVT was used, check for dmesg for something like this:

CVT Mode - <pix>M<n>[-R], ie: .480M3-R  (800x600 reduced blanking)

where: pix - product of xres and yres, in MB
    M   - is a CVT mode
    n   - the aspect ratio (3 - 4:3; 4 - 5:4; 9 - 16:9, 15:9; A - 16:10)
    -R   - reduced blanking
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>