The audit of _p usage shows various drivers assume inb_p is somehow atomic.
 Of course it isn't and the delay can be split from the I/O cycle causing a
timing violation on chips that matter (eg this one)

With the proposed use of udelay() for some _p delays this will cease to be
a mostly theoretical bug (as the delay stall is unsplittable) and wants
fixing.

Lots of other drivers need fixing this way too.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
  selinux: make mls_compute_sid always polyinstantiate
  security/selinux: constify function pointer tables and fields
  security: add a secctx_to_secid() hook
  security: call security_file_permission from rw_verify_area
  security: remove security_sb_post_mountroot hook
  Security: remove security.h include from mm.h
  Security: remove security_file_mmap hook sparse-warnings (NULL as 0).
  Security: add get, set, and cloning of superblock security information
  security/selinux: Add missing "space"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
  [AVR32] extint: Set initial irq type to low level
  [AVR32] extint: change set_irq_type() handling
  [AVR32] NMI debugging
  [AVR32] constify function pointer tables
  [AVR32] ATNGW100: Update defconfig
  [AVR32] ATSTK1002: Update defconfig
  [AVR32] Kconfig: Choose daughterboard instead of CPU
  [AVR32] Add support for ATSTK1003 and ATSTK1004
  [AVR32] Clean up external DAC setup code
  [AVR32] ATSTK1000: Move gpio-leds setup to setup.c
  [AVR32] Add support for AT32AP7001 and AT32AP7002
  [AVR32] Provide more CPU information in /proc/cpuinfo and dmesg
  [AVR32] Oprofile support
  [AVR32] Include instrumentation menu
  Disable VGA text console for AVR32 architecture
  [AVR32] Enable debugging only when needed
  ptrace: Call arch_ptrace_attach() when request=PTRACE_TRACEME
  [AVR32] Remove redundant try_to_freeze() call from do_signal()
  [AVR32] Drop GFP_COMP for DMA memory allocations

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw: (56 commits)
  [GFS2] Allow journal recovery on read-only mount
  [GFS2] Lockup on error
  [GFS2] Fix page_mkwrite truncation race path
  [GFS2] Fix typo
  [GFS2] Fix write alloc required shortcut calculation
  [GFS2] gfs2_alloc_required performance
  [GFS2] Remove unneeded i_spin
  [GFS2] Reduce inode size by moving i_alloc out of line
  [GFS2] Fix assert in log code
  [GFS2] Fix problems relating to execution of files on GFS2
  [GFS2] Initialize extent_list earlier
  [GFS2] Allow page migration for writeback and ordered pages
  [GFS2] Remove unused variable
  [GFS2] Fix log block mapper
  [GFS2] Minor correction
  [GFS2] Eliminate the no longer needed sd_statfs_mutex
  [GFS2] Incremental patch to fix compiler warning
  [GFS2] Function meta_read optimization
  [GFS2] Only fetch the dinode once in block_map
  [GFS2] Reorganize function gfs2_glmutex_lock
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (125 commits)
  [CRYPTO] twofish: Merge common glue code
  [CRYPTO] hifn_795x: Fixup container_of() usage
  [CRYPTO] cast6: inline bloat--
  [CRYPTO] api: Set default CRYPTO_MINALIGN to unsigned long long
  [CRYPTO] tcrypt: Make xcbc available as a standalone test
  [CRYPTO] xcbc: Remove bogus hash/cipher test
  [CRYPTO] xcbc: Fix algorithm leak when block size check fails
  [CRYPTO] tcrypt: Zero axbuf in the right function
  [CRYPTO] padlock: Only reset the key once for each CBC and ECB operation
  [CRYPTO] api: Include sched.h for cond_resched in scatterwalk.h
  [CRYPTO] salsa20-asm: Remove unnecessary dependency on CRYPTO_SALSA20
  [CRYPTO] tcrypt: Add select of AEAD
  [CRYPTO] salsa20: Add x86-64 assembly version
  [CRYPTO] salsa20_i586: Salsa20 stream cipher algorithm (i586 version)
  [CRYPTO] gcm: Introduce rfc4106
  [CRYPTO] api: Show async type
  [CRYPTO] chainiv: Avoid lock spinning where possible
  [CRYPTO] seqiv: Add select AEAD in Kconfig
  [CRYPTO] scatterwalk: Handle zero nbytes in scatterwalk_map_and_copy
  [CRYPTO] null: Allow setkey on digest_null 
  ...

This can be broken down into these major areas:
 - Documentation updates (language translations and fixes, as
   well as kobject and kset documenatation updates.)
 - major kset/kobject/ktype rework and fixes.  This cleans up the
   kset and kobject and ktype relationship and architecture,
   making sense of things now, and good documenation and samples
   are provided for others to use.  Also the attributes for
   kobjects are much easier to handle now.  This cleaned up a LOT
   of code all through the kernel, making kobjects easier to use
   if you want to.
 - struct bus_type has been reworked to now handle the lifetime
   rules properly, as the kobject is properly dynamic.
 - struct driver has also been reworked, and now the lifetime
   issues are resolved.
 - the block subsystem has been converted to use struct device
   now, and not "raw" kobjects.  This patch has been in the -mm
   tree for over a year now, and finally all the issues are
   worked out with it.  Older distros now properly work with new
   kernels, and no userspace updates are needed at all.
 - nozomi driver is added.  This has also been in -mm for a long
   time, and many people have asked for it to go in.  It is now
   in good enough shape to do so.
 - lots of class_device conversions to use struct device instead.
   The tree is almost all cleaned up now, only SCSI and IB is the
   remaining code to fix up...

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6: (196 commits)
  Driver core: coding style fixes
  Kobject: fix coding style issues in kobject c files
  Kobject: fix coding style issues in kobject.h
  Driver core: fix coding style issues in device.h
  spi: use class iteration api
  scsi: use class iteration api
  rtc: use class iteration api
  power supply : use class iteration api
  ieee1394: use class iteration api
  Driver Core: add class iteration api
  Driver core: Cleanup get_device_parent() in device_add() and device_move()
  UIO: constify function pointer tables
  Driver Core: constify the name passed to platform_device_register_simple
  driver core: fix build with SYSFS=n
  sysfs: make SYSFS_DEPRECATED depend on SYSFS
  Driver core: use LIST_HEAD instead of call to INIT_LIST_HEAD in __init
  kobject: add sample code for how to use ksets/ktypes/kobjects
  kobject: add sample code for how to use kobjects in a simple manner.
  kobject: update the kobject/kset documentation
  kobject: remove old, outdated documentation.
  ...

If the node we're booting on doesn't have memory, bootstrapping kmalloc()
caches resorts to fallback_alloc() which requires ->nodelists set for all
nodes.  Fix that by calling set_up_list3s() for CACHE_CACHE in
kmem_cache_init().

As kmem_getpages() is called with GFP_THISNODE set, this used to work before
because of breakage in 2.6.22 and before with GFP_THISNODE returning pages from
the wrong node if a node had no memory. So it may have worked accidentally and
in an unsafe manner because the pages would have been associated with the wrong
node which could trigger bug ons and locking troubles.
Tested-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[ With additional one-liner by Olaf Hering  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix overwriting the stack with the version string
(it is currently 10 bytes + zero) when unloading the
capidrv module. Safeguard against overwriting it
should the version string grow in the future.

Should fix Kernel Bug Tracker Bug 9696.
Signed-off-by: Gerd v. Egidy <gerd.von.egidy@intra2net.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch allows gfs2 to perform journal recovery even if it is mounted
read-only. Strictly speaking, a read-only mount should not be writing to
the filesystem, but we do this only to perform journal recovery. A
read-only mount will fail if we don't recover the dirty journal. Also,
when gfs2 is used as a root filesystem, it will be mounted read-only
before being mounted read-write during the boot sequence. A failed
read-only mount will panic the machine during bootup.
Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

I spotted this bug while I was digging around.  Looks like it could cause
a lockup in some rare error condition.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

There was a bug in the truncation/invalidation race path for
->page_mkwrite for gfs2. It ought to return 0 so that the effect is the
same as if the page was truncated at any of the other points at which
the page_lock is dropped. This will result in the restart of the whole
page fault path. If it was due to a real truncation (as opposed to an
invalidate because we let a glock go) then the ->fault path will pick
that up when it gets called again.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch fixes a minor typo.  Surprisingly, it still compiled.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

The comparison was being made against the wrong quantity.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This is a small I/O performance enhancement to gfs2.  (Actually, it is a rework of
an earlier version I got wrong).  The idea here is to check if the write extends
past the last block in the file.  If so, the function can save itself a lot of
time and trouble because it knows an allocate will be required.  Benchmarks like
iozone should see better performance.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch removes a vestigial variable "i_spin" from the gfs2_inode
structure.  This not only saves us memory (>300000 of these in memory
for the oom test) it also saves us time because we don't have to
spend time initializing it (i.e. slightly better performance).
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

It is possible to reduce the size of GFS2 inodes by taking the i_alloc
structure out of the gfs2_inode. This patch allocates the i_alloc
structure whenever its needed, and frees it afterward. This decreases
the amount of low memory we use at the expense of requiring a memory
allocation for each page or partial page that we write. A quick test
with postmark shows that the overhead is not measurable and I also note
that OCFS2 use the same approach.

In the future I'd like to solve the problem by shrinking down the size
of the members of the i_alloc structure, but for now, this reduces the
immediate problem of using too much low-memory on x86 and doesn't add
too much overhead.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Although the values were all being calculated correctly, there was a
race in the assert due to the way it was using atomic variables. This
changes the value we assert on so that we get the same effect by testing
a different variable. This prevents the assert triggering when it shouldn't.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch fixes a couple of problems which affected the execution of files
on GFS2. The first is that there was a corner case where inodes were not
always uptodate at the point at which permissions checks were being carried
out, this was resulting in refusal of execute permission, but only on the
first lookup, subsequent requests worked correctly. The second was a problem
relating to incorrect updating of file sizes which was introduced with the
write_begin/end code for GFS2 a little while back.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>

Here is a patch for the latest upstream GFS2 code:
The journal extent map needs to be initialized sooner than it
currently is.  Otherwise failed mount attempts (e.g. not enough
journals, etc.) may panic trying to access the uninitialized list.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

To improve performance on NUMA, we use the VM's standard page
migration for writeback and ordered pages. Probably we could
also do the same for journaled data, but that would need a
careful audit of the code, so will be the subject of a later
patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

The go_drop_th function is never called or referenced.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

A missing offset in the calculation.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This is a small correction to my previously posted patch1.
It just changes a divide to a shift.  It's faster and doesn't
introduce odd dependencies on 32-bit compiles.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch eliminates the unneeded sd_statfs_mutex mutex but preserves
the ordering as discussed.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch optimizes function gfs2_meta_read.  Basically, gfs2_meta_wait
was being called regardless of whether a disk read was requested.
This just pulls that wait into the if that triggers the read.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Function gfs2_block_map was often looking up the disk inode twice.
This optimizes it so that only does it once.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch optimizes the function gfs2_glmutex_lock.
The basic theory is: Why bother initializing a holder, setting up
wait bits and then waiting on them, if you know the glock can be
yours.  So the holder stuff is placed inside the if checking if the
glock is locked.  This one needs careful scrutiny because changing
anything to do with locking should strike terror into one's heart.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

I eliminated the passing of an unused parameter into gfs2_bitfit called rgd.

This also changes the gfs2_bitfit code that searches for free (or used) blocks.
Before, the code was trying to check for bytes that indicated 4 blocks in
the undesired state.  The problem is, it was spending more time trying to
do this than it actually was saving.  This version only optimizes the case
where we're looking for free blocks, and it checks a machine word at a time.
So on 32-bit machines, it will check 32-bits (16 blocks) and on 64-bit
machines, it will check 64-bits (32 blocks) at a time.  The compiler
optimizes that quite well and we save some time, especially when running
through full bitmaps (like the bitmaps allocated for the journals).

There's probably a more elegant or optimized way to do this, but I haven't
thought of it yet.  I'm open to suggestions.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This just eliminates an unused variable from the quota code.
Not likely to be a time saver.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch saves a little time when gfs2 writes to the journals by
keeping a mapping between logical and physical blocks on disk.
That's better than constantly looking up indirect pointers in
buffers, when the journals are several levels of indirection
(which they typically are).
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch is just a cleanup.  Function gfs2_get_block() just calls
function gfs2_block_map reversing the last two parameters.  By
reversing the parameters, gfs2_block_map() may be called directly
and function gfs2_get_block may be eliminated altogether.
Since this function is done for every block operation,
this streamlines the code and makes it a little bit more efficient.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

The fl_owner is that of lockd when posix locks arrive from nfs
clients, so it can't be used to distinguish between lock holders.
Use fl_pid as owner instead; it's the pid of the process on the
nfs client.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

A certain scenario in the rename code path triggers a kernel BUG()
because it accidentally does recursive locking The first lock is
requested to unlink an already existing inode (replacing a file) and the
second lock is requested when the destination directory needs to alloc
some space. It is rare that these two
events happen during the same rename call, and even more rare that these
two instances try to lock the same rgrp. It is, however, possible.
https://bugzilla.redhat.com/show_bug.cgi?id=404711Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2 supports two modes of locking - lock_nolock for single node filesystem
and lock_dlm for cluster mode locking. The gfs2 lock methods are removed from
file operation table for lock_nolock protocol. This would allow VFS to handle
posix lock and flock logics just like other in-tree filesystems without
duplication.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Hi Steven,

Steven Whitehouse wrote:
> Hi,
>
> Now in the -nmw git tree. Thanks,
>
> Steve.
>
> On Wed, 2007-11-21 at 11:54 -0600, Ryan O'Hara wrote:

this patch introduces a bunch of build warnings by leaving around

struct inode *inode = &ip->i_inode;

The patch in attachment cleans them up. Please apply.
Signed-off-by: Fabio Massimo Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Remove read/write permission() checks from xattr operations.
VFS layer is already handling permission for xattrs via the
xattr_permission() call, so there is no need for gfs2 to
check permissions. Futhermore, using permission() for SELinux
xattrs ops is incorrect.
Signed-off-by: Ryan O'Hara <rohara@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

The issue is indeed UP vs SMP and it is totally random.

spin_is_locked() is a bad assertion because there is no correct answer on UP.
on UP spin_is_locked() has to return either one value or another, always.

This means that in my setup I am lucky enough to trigger the issue and your you
are lucky enough not to.

the patch in attachment removes the bogus calls to BUG_ON and according to David
(in CC and thanks for the long explanation on the problem) we can rely upon
things like lockdep to find problem that might be trying to catch.
Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>