Don't just do nothing: it'll cause busywaits all over writeback and page
reclaim.

For now, take a fixed-length nap.  Will improve when NFS starts waking up
throttled processes.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the Ext3 device ioctl compat stuff from fs/compat_ioctl.c to the Ext3
driver so that the Ext3 header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the ReiserFS device ioctl compat stuff from fs/compat_ioctl.c to the
ReiserFS driver so that the ReiserFS header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move common FS-specific ioctls from linux/ext2_fs.h to linux/fs.h as FS_IOC_*
and FS_IOC32_* and have the users of them use those as a base.

Also move the GETFLAGS/SETFLAGS flags to linux/fs.h as FS_*_FL macros, and then
have the other users use them as a base.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the loop device ioctl compat stuff from fs/compat_ioctl.c to the loop
driver so that the loop header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Dissociate the generic_writepages() function from the mpage stuff, moving its
declaration to linux/mm.h and actually emitting a full implementation into
mm/page-writeback.c.

The implementation is a partial duplicate of mpage_writepages() with all BIO
references removed.

It is used by NFS to do writeback.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Create a new header file, fs/internal.h, for common definitions local to the
sources in the fs/ directory.

Move extern definitions that should be in header files from fs/*.c to
fs/internal.h or other main header files where they span directories.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove the duplicate declaration of exit_io_context() from linux/sched.h.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move some functions out of the buffering code that aren't strictly buffering
specific.  This is a precursor to being able to disable the block layer.

 (*) Moved some stuff out of fs/buffer.c:

     (*) The file sync and general sync stuff moved to fs/sync.c.

     (*) The superblock sync stuff moved to fs/super.c.

     (*) do_invalidatepage() moved to mm/truncate.c.

     (*) try_to_release_page() moved to mm/filemap.c.

 (*) Moved some related declarations between header files:

     (*) declarations for do_invalidatepage() and try_to_release_page() moved
     	 to linux/mm.h.

     (*) __set_page_dirty_buffers() moved to linux/buffer_head.h.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NJens Axboe <axboe@suse.de>

We can use this information for making more intelligent priority
decisions, and it will also be useful for blktrace.
Signed-off-by: NJens Axboe <axboe@suse.de>

CFQ implements this on its own now, but it's really block layer
knowledge. Tells a device queue to start dispatching requests to
the driver, taking care to unplug if needed. Also fixes the issue
where as/cfq will invoke a stopped queue, which we really don't
want.
Signed-off-by: NJens Axboe <axboe@suse.de>

Some were kmalloc_node(), some were still kmalloc(). Change them all to
kmalloc_node().
Signed-off-by: NJens Axboe <axboe@suse.de>

Signed-off-by: NJens Axboe <axboe@suse.de>

None of the in-kernel primitives for handling "atomic" counting seem
to be a good fit. We need something that is essentially free for
incrementing/decrementing, while the read side may be more expensive
as we only ever need to do that when a device is removed from the
kernel.

Use a per-cpu variable for maintaining a per-cpu ioc count and define
a reading mechanism that just sums up the values.
Signed-off-by: NJens Axboe <axboe@suse.de>

cfq_exit_lock is protecting two things now:

- The per-ioc rbtree of cfq_io_contexts

- The per-cfqd linked list of cfq_io_contexts

The per-cfqd linked list can be protected by the queue lock, as it is (by
definition) per cfqd as the queue lock is.

The per-ioc rbtree is mainly used and updated by the process itself only.
The only outside use is the io priority changing. If we move the
priority changing to not browsing the rbtree, we can remove any locking
from the rbtree updates and lookup completely. Let the sys_ioprio syscall
just mark processes as having the iopriority changed and lazily update
the private cfq io contexts the next time io is queued, and we can
remove this locking as well.
Signed-off-by: NJens Axboe <axboe@suse.de>

Move some members around and unionize completion_data and rb_node since
they cannot ever be used at the same time.
Signed-off-by: NJens Axboe <axboe@suse.de>

It's not needed for anything, so kill the bio passing.
Signed-off-by: NJens Axboe <axboe@suse.de>

After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.

So kill/clean the remaining users, straight forward.
Signed-off-by: NJens Axboe <axboe@suse.de>

It is always identical to &q->rq, and we only use it for detecting
whether this request came out of our mempool or not. So replace it
with an additional ->flags bit flag.
Signed-off-by: NJens Axboe <axboe@suse.de>

As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Then we have enough room in the request to get rid of the dynamic
allocations in CFQ/AS.
Signed-off-by: NJens Axboe <axboe@suse.de>

We can track this in struct request.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>

The io schedulers can use this instead of having to allocate space for
it themselves.
Signed-off-by: NJens Axboe <axboe@suse.de>

The rbtree sort/lookup/reposition logic is mostly duplicated in
cfq/deadline/as, so move it to the elevator core. The io schedulers
still provide the actual rb root, as we don't want to impose any sort
of specific handling on the schedulers.

Introduce the helpers and rb_node in struct request to help migrate the
IO schedulers.
Signed-off-by: NJens Axboe <axboe@suse.de>

The conditions got reserved. Also make rb_next() and rb_prev() check
for the empty condition.
Signed-off-by: NJens Axboe <axboe@suse.de>

Right now, every IO scheduler implements its own backmerging (except for
noop, which does no merging). That results in duplicated code for
essentially the same operation, which is never a good thing. This patch
moves the backmerging out of the io schedulers and into the elevator
core. We save 1.6kb of text and as a bonus get backmerging for noop as
well. Win-win!
Signed-off-by: NJens Axboe <axboe@suse.de>

Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: NJens Axboe <axboe@suse.de>

Signed-off-by: NChas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MSI is defined to be 32-bit write.  The 5706 does 64-bit MSI writes
with byte enables disabled on the unused 32-bit word.  This is legal
but causes problems on the AMD 8132 which will eventually stop
responding after a while.

Without this patch, the MSI test done by the driver during open will
pass, but MSI will eventually stop working after a few MSIs are
written by the device.

AMD believes this incompatibility is unique to the 5706, and
prefers to locally disable MSI rather than globally disabling it
using pci_msi_quirk.

Update version to 1.4.45.
Signed-off-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix some issues Steve Grubb had with the way NetLabel was using the audit
subsystem.  This should make NetLabel more consistent with other kernel
generated audit messages specifying configuration changes.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NSteve Grubb <sgrubb@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New code clobbers the result always early, so tell gcc about it
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

Use prototypes in headers
Don't define panic_on_unrecovered_nmi for all architectures

Cc: dzickus@redhat.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Noticed by Al Viro

Cc: viro@ftp.linux.org.uk
Signed-off-by: NAndi Kleen <ak@suse.de>

Add access control lists for tmpfs.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The patches solve the following problem: We want to grant access to devices
based on who is logged in from where, etc.  This includes switching back and
forth between multiple user sessions, etc.

Using ACLs to define device access for logged-in users gives us all the
flexibility we need in order to fully solve the problem.

Device special files nowadays usually live on tmpfs, hence tmpfs ACLs.

Different distros have come up with solutions that solve the problem to
different degrees: SUSE uses a resource manager which tracks login sessions
and sets ACLs on device inodes as appropriate.  RedHat uses pam_console, which
changes the primary file ownership to the logged-in user.  Others use a set of
groups that users must be in in order to be granted the appropriate accesses.

The freedesktop.org project plans to implement a combination of a
console-tracker and a HAL-device-list based solution to grant access to
devices to users, and more distros will likely follow this approach.

These patches have first been posted here on 2 February 2005, and again
on 8 January 2006. We have been shipping them in SLES9 and SLES10 with
no problems reported.  The previous submission is archived here:

   http://lkml.org/lkml/2006/1/8/229
   http://lkml.org/lkml/2006/1/8/230
   http://lkml.org/lkml/2006/1/8/231

This patch:

Add some infrastructure for access control lists on in-memory
filesystems such as tmpfs.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I've been using systemtap for some debugging and I noticed that it can't
probe a lot of modules.  Turns out it's kind of silly, the sections section
of /sys/module is limited to 32byte filenames and many of the actual
sections are a a bit longer than that.

[akpm@osdl.org: rewrite to use dymanic allocation]
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ratelimit_pages in page-writeback.c is recalculated (in set_ratelimit())
every time a CPU is hot-added/removed.  But this value is not recalculated
when new pages are hot-added.

This patch fixes that problem by calling set_ratelimit() when new pages
are hot-added.

[akpm@osdl.org: cleanups]
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>