Yes it's a GCC optimiser bug.  I'm surprised I didn't see it: I tried
a whole heap of different compilers on that code, and had problems
only on the earlier similar code in raid0_run().

I didn't try redhat's compilers (I run debian) but didn't expect the
behaviour to be that different.

Anyway, please apply this patch (which also fixes the chunk overlap
problems).

there was a bug in fysnc_buffers_list() in 2.4 (fixed in 2.4.19) that
could cause the function to return without having written the current
contents of all the buffers.

Obviously, this could be bad for anybody relying on ordering using
O_SYNC or fsync().  If an I/O was already in flight for a particular bh
at the time of the call to fsync_buffers_list(), ll_rw_block() will not
initiate a new I/O even though the contents may have changed.  It is
therefore necessary to wait before the call.  Here's a patch against
2.5.42 that applies the same fix.

into home.transmeta.com:/home/torvalds/v2.5/linux

into home.transmeta.com:/home/torvalds/v2.5/linux

Rename queue_depth to current_queue_depth so that:

A) we represent the true purpose of the variable
B) we catch anyone using it wrongly

This patch for dpt_i2o fixes TCQ stuff, but doesn't solve DMA mapping
issues (so it still doesn't work, but it's not because of TCQ).

Getting around to fixing DMA mapping API issues is much more work per
driver than the TCQ stuff, so I'm putting it off until later.

dpti.h:
  Update template
dpt_i2o.c:
  Update to new TCQ scheme

aic7xxx_linux_host.h:
  Update host template
aic7xxx_linux.c:
  Update to new TCQ scheme

linit.c:
  Update to use slave_attach

eata.h:
  Update template
eata.c:
  Add slave_attach and new TCQ method

qla1280.h:
  Update device template
qla1280.c:
  Update to use slave_attach for setting queue depth

advansys.h:
  Update host template to include slave_attach
advansys.c:
  Update to use slave_attach instead of select_queue_depths

drivers/scsi/esp.c:
  Fix the build.
scsi.h:
  Add struct list_head items for future (but soon) use
hosts.h:
  Remove select_queue_depths from host struct, add struct list
  stuff for proper list linking of host structs
hosts.c:
  Don't touch select_queue_depths any longer

ips.h:
  Since we now have proper tagged depth setting, make
  the cmd_per_lun value reasonable for untagged devices
  like it is suppossed to be.

More scsi TCQ updates, tweak to ServeRAID, tweak scsi_scan, make BusLogic
use new method

into home.transmeta.com:/home/torvalds/v2.5/linux

- switch to using scsi_ioctl() for drive door locking and unlocking
  instead of private code
- use a driver internal flag to save the reset status until tape is
  positioned into known location
- set driver state properly for all partitions after reset
- change put_device() to driver_unregister() in st_detach()
- C99 initializer changes (from Art Haas)

into home.transmeta.com:/home/torvalds/v2.5/linux

This is my current futex patchset against BK-curr.  It mostly includes
must-have crash/correctness fixes from Martin Wirth, tested and reworked
somewhat by myself:

 - crash fix: futex_close did not detach from the vcache. Detach cleanups.
   (Martin Wirth)

 - memory leak fix: forgotten put_page() in a rare path in __pin_page().
   (Martin Wirth)

 - crash fix: do not do any quickcheck in unqueue_me(). (Martin, me)

 - correctness fix: the fastpath in __pin_page() now handles reserved
   pages the same way get_user_pages() does. (Martin Wirth)

 - queueing improvement: __attach_vcache() now uses list_add_tail() to
   avoid the reversal of the futex queue if a COW happens. (Martin Wirth)

 - simplified alignment check in sys_futex. (Martin Wirth)

 - comment fix: make it clear how the vcache hash quickcheck works. (me)

Make dcookies use a stable size regardless of whether we're
on a 32-bit or 64-bit platform.

Finally, add the i386 timer-interrupt and perfctr drivers for i386

Add the oprofile core.  The core design is very similar to that we
discussed in private mail.  The nasty details should be documented in
the patch below.

Add the MSR defines oprofile uses

This provides a simple api to let oprofile hook into the NMI interrupt
for the perfctr profiler.

This implements a simple hook into the profiling timer for x86 so that
non-perfctr machines can still use oprofile.  This has proven useful for
laptops and the like.

It also reduces header dependencies a bit by centralising readprofile
code

This implements the persistent path-to-dcookies mapping, and adds a
system call for the user-space profiler to look up the profile data, so
it can tag profiles to specific binaries.

This implements the simple hooks we need to catch unmappings, and to
make sure no stale task_struct*'s are ever used by the main oprofile
core mechanism.  If disabled, it compiles to nothing.

Quite a few drivers don't need ->open() anymore - all it did was checking
that minor is good (== gendisk exists).  That is handled by generic code
now...

There we go - now we can put a reference to gendisk into block_device.  Which
we do in do_open().  Most of the callers of get_gendisk() are simply using
bdev->bd_disk now (and most of the put_disk() calls introduced on previous
step disappear).  We also put that pointer into struct request - ->rq_disk.
That allows to get rid of disk_index() kludges in md.c (we simply count
relevant IO in the struct gendisk fields) and kill the export of get_gendisk().
	Notice that by now we can move _all_ IO counters into gendisk.  That
will kill a bunch of per-major arrays and more importantly, allow to merge
sard in clean way.  FWIW, we probably could show them as disk/partitions
attributes in driverfs...

Finally.  We use disk->dev.refcount as a gendisk refcount.  New helper -
get_disk(): atomic_inc on refcount.  get_gendisk() does it on return,
callers of get_gendisk() do put_disk() when they are done.

	* disk->disk_dev is initialized in alloc_disk(), device_add()'d in
	  add_disk(), device_del()'d in unregister_disk() and device_put() in
	  put_disk().
	* devices of partitions are made its children.
	* attributes of disk one: dev (dev_t of the thing), range (number of
	  minors) and size (in sectors).
	* attributes of partition ones: dev (ditto), start (in sectors) and
	  size (in sectors).
	* disk devices are put on a new bus - "block"
	* if caller of add_disk() had set disk->driverfs_dev, we set symlinks:
	  "device" from disk to underlying device and "block" from underlying
	  device to disk.
	* ->release() of disk_dev frees disk and disk->part.
	At that point we have sane driverfs subtree for each gendisk and
refcount of its root (disk->disk_dev) can act as gendisk refcount.

	* update_partition() split into add_partition() and delete_partition().
	* all updating of ->part[] is switched to these two (including initial
filling/final cleaning).
	* per-partition devices are allocated on-demand and never reused.
We allocate struct device in add_partition() and put reference to it into
hd_struct.  ->release() for that struct device frees it.  delete_partition()
removes reference from hd_struct and does put_device() on it.  Basically,
we get rid of problems with reused struct device by never reusing them...
	At that point devices for partitions are nice and sane.

	guts of blkpg.c and blkdev_ioctl() sanitized up and moved into a new
file - drivers/block/ioctl.c.  blkpg.c is gone.

	new driverfs helpers - device_initialize/device_add and device_del.
The latter is device_unregister() sans the final put_device().  The former
is splitup of device_register() into initialization and insertion into tree.

	new field - disk->minors (1 << disk->minor_shift).  Almost all uses
of ->minor_shift had that form and thus had been replaced.

allocation of ->part[] moved to alloc_disk(); alloc_disk() got an
argument (number of minors expected).  Freeing is in put_disk().

into home.transmeta.com:/home/torvalds/v2.5/linux

arch and os Makefiles.