new helpers - get_capacity(gendisk)/set_capacity(gendisk, sectors).
Drivers switched to these; that eliminates most of the accesses to
disk->part[]... in the drivers (and makes code more readable, while
we are at it).  That had caught several bugs when minor had been
used in place of minor>>minor_shift (acsi.c is especially nasty in
that respect; I don't know if it had ever been used with multiple
devices...)

	Since ->nr_real is always 1 now, we can remove that field completely.
Removed the last remnants of switch in disk_name() (it could be killed
a long time ago, I just forgot to remove the last two cases when md and i2o
got converted).  Collapsed several instances of
disk->part[minor - disk->first_minor] - in cases when we know that we deal
with disk->part[0].

Misc.  compile fixes, xd.c switched to per-disk gendisks, Alan's 2.4
fixes for xd.c ported.

ps2esdi.c switched to per-disk gendisks

Big One.  Flushing/rereading partition tables is taken from
->revalidate() for partitioned devices; now it's done in the
caller (check_disk_change()).  BLKRRPART handling also moved
out of drivers - they are still allowed to override it (DAC960
and i2o are the only remaining ones), but common case is handled
in fs/block_dev.c.

Note: we are still only shifting stuff - bd_sem deadlocks in
check_disk_change() are still there.  However, now we have all
relevant code outside of drivers and that will allow to fix the
thing (see next patches).

kills use of blk_size[] for partitioned devices, removes ->sizes from
struct gendisk.

Use register_blkdev and unregister_blkdev as before, and everything will work just fine.

blk_ioctl() not exported anymore; calls moved from drivers to block_dev.c.

Horrors with open/reread_partition exclusion are starting to get fixed.

It's not the final variant, but at least we are getting the logics into
one place; switch to final variant will happen once we get per-disk
analog of gendisks.  New fields - ->bd_part_sem and ->bd_part_count.

The latter counts the amount of opened partitions.  The former protects
said count _and_ is held while we are rereading partition tables.
Helpers - dev_part_lock()/dev_part_unlock() (currently taking kdev_t; that
will change pretty soon).  No more ->open() and ->release() for partitions,
all that logics went to generic code.  Lock hierachy is currently messy:

  ->bd_sem for partitions -> ->bd_part_sem -> ->bd_sem for entire disks

Ugly, but that'll go away and to get the final variant of locking right
now would take _really_ big patch - with a lot of steps glued together.
The damn thing is large as it is...

end_request(int) turned to end_request(req, int); all old callers
are converted to end_request(CURRENT, value).  Now we can start
killing CURRENT/QUEUE - end_request() was the last obstacle to
that.

ditto for DEVICE_INTR/CLEAR_INTR.  do_mfm/do_acsi/do_hd/... are
explicitly declared in the drivers that use DEVICE_INTR stuff;
DEVICE_INTR/CLEAR_INTR is gone from blk.h.

monstrous cascade of #ifdefs is gone from blk.h.  This is the first
step of cleanup - we move #define in question into the code that
includes blk.h (i.e. DEVICE_NR, DEVICE_NAME and DEVICE_INTR are
explicitly set by drivers).

checks return codes, and sanitises resource allocation.

 - Eliminate all usages of the obscure QUEUE_EMPTY macro.

 - Eliminate all unneccessary checks for RQ_INACTIVE, this can't happen during
   the time we run the request strategy routine of a single major number block
   device. Perhaps the still remaining usage in scsi and i2o_block.c should be
   killed as well, since the upper ll_rw_blk layer shouldn't pass inactive
   requests down.

Those are all places where we have deeply burried and hidden major number
indexed arrays. Let's deal with them slowly...

 - Move ll_10byte_cmd_build to the only place where it's used: ide-cd.  The SCSI
   layer does have it's own implementation which additionally it's messing
   around with the hard_nr_sectors struct request value.  One should *not*
   provide "infrastructure" until its really used as such.

   If anywhere this should reside in a file called ATAPI.

 - Unfold the INIT_REQUEST macro from blk.h. This showed up plenty of duplicate
   checks for QUEUE_EMPTY. Clean them as well. Remove the over cautious
   major(CURRENT->rq_dev != MAJOR_NR) checks. During the last several years I
   never saw any report about it. Looking at the !CURRENT->bio it is clear that
   dereferencing NULL will provide the same kind of panic as the check.  Some
   comments around the code in question show nicely that indeed INIT_REQUEST
   was a good example of code obfuscation.

 - A short look at RQ_INACTIVE shows that it is only used inside the scsi.c file
   and during the removal of devices. This shows that the many checks for
   RQ_INACTIVE are not necessary. Looking closer even shows that some of them
   did happen before checks for an empty queue. Plenty of drivers didn't care
   about it and the CD-ROM ones should be handled properly, because the
   most common drivers would fail as well. Comments indicate that this
   was an leftover from 1.3 days...

Done by William Stinson.
Adds error handling to request_region() calls,
and converts some old check_region() calls too.

 - put block size in bdev->bd_block_size, make do_open() and
   check_partition() to set it (see above), switch set_blocksize() and
   block_size() to use of ->bd_block_size.  Remove manipulations with
   blksize_size[] from drivers, remove blksize_size[] itself.

Originally by Christoph Hellwig back in February.
It recieved no objections when posted to l-k & Jens.

o remove DEVICE_REQUEST definitions - never used in blk.h itself.
o remove DEVICE_ON() - never used at all.
o define LOCAL_END_REQUEST when we do not want end_request() instead
  of other hacks.
o remove DEVICE_OFF() - only used in floppy driver, thus one now has
  a private end_request().
o use private end_request() functions for drivers not providing
  randomness.
o remove TIMEOUT_VALUE - only ever used in hd.c

Just the usual removal of the dead global arrays and associated cruft.
(Thistime not affecting lvm, which BTW. doesn't compile currently anyway
;-).

- Al Viro: VFS inode allocation moved down to filesystem, trim inodes
- Greg KH: USB update, hotplug documentation
- Kai Germaschewski: ISDN update
- Ingo Molnar: scheduler tweaking ("J2")
- Arnaldo: emu10k kdev_t updates
- Ben Collins: firewire updates
- Björn Wesen: cris arch update
- Hal Duston: ps2esdi driver bio/kdev_t fixes
- Jean Tourrilhes: move wireless drivers into drivers/net/wireless,
update wireless API #1
- Richard Gooch: devfs race fix
- OGAWA Hirofumi: FATFS update

- Davide Libenzi: nicer timeslices for scheduler
- Arnaldo: wd7000 scsi driver cleanups and bio update
- Greg KH: USB update (including initial 2.0 support)
- me: strict typechecking on "kdev_t"

- Dave Jones: more merging, fix up last merge..
- release to sync with Dave

- Jens Axboe: more bio updates, fix some request list bogosity under load
- Al Viro: export seq_xxx functions
- Manfred Spraul: include file cleanups, pc110pad compile fix
- David Woodhouse: fix JFFS2 write error handling
- Dave Jones: start merging up with 2.4.x patches
- Manfred Spraul: coredump fixes, FS event counter cleanups
- me: fix SCSI CD-ROM sectorsize BIO breakage

- Al Viro: floppy_eject cleanup, mount cleanups
- Jens Axboe: bio updates
- Ingo Molnar: mempool fixes
- GOTO Masanori: Fix O_DIRECT error handling

- Jeff Garzik: no longer support old cards in tulip driver
(see separate driver for old tulip chips)
- Pat Mochel: driverfs/device model documentation
- Ballabio Dario: update eata driver to new IO locking
- Ingo Molnar: raid resync with new bio structures (much more efficient)
and mempool_resize()
- Jens Axboe: bio queue locking

- Jeff Garzik: separate out handling of older tulip chips
- Jens Axboe: more bio stuff
- Anton Altaparmakov: NTFS 1.1.21 update

- Greg KH: USB update
- Richard Gooch: refcounting for devfs
- Jens Axboe: start of new block IO layer

  - Ivan Kokshaysky: fix alpha dec_and_lock with modules, for alpha config entry
  - Kai Germaschewski: ISDN updates
  - Jeff Garzik: network driver updates, sysv fs update
  - Kai Mäkisara: SCSI tape update
  - Alan Cox: large drivers merge
  - Nikita Danilov: reiserfs procfs information
  - Andrew Morton: ext3 merge
  - Christoph Hellwig: vxfs livelock fix
  - Trond Myklebust: NFS updates
  - Jens Axboe: cpqarray + cciss dequeue fix
  - Tim Waugh: parport_serial base_baud setting
  - Matthew Dharm: usb-storage Freecom driver fixes
  - Dave McCracken: wait4() thread group race fix

  - me: fix page flags race condition Andrea found
  - David Miller: sparc and network updates
  - various: fix loop driver that thought it was part of the VM system
  - me: teach DRM about VM_RESERVED
  - Alan Cox: more merging

  - Alan Cox: more merging
  - Alexander Viro: block device module race fixes
  - Richard Henderson: mmap for 32-bit alpha personality
  - Jeff Garzik: 8139 and natsemi update

  - Jens Axboe: clean up duplicate unused request list
  - Jeff Mahoney: reiserfs endianness finishing touches
  - Hugh Dickins: some further swapoff fixes and cleanups
  - prepare-for-Alan: move drivers/i2o into drivers/message/i2o
  - Leonard Zubkoff: 2TB disk device fixes
  - Paul Schroeder: mwave config enable
  - Urban Widmark: fix via-rhine double free..
  - Tom Rini: PPC fixes
  - NIIBE Yutaka: SuperH update

  - Alan Cox: continued merging
  - Mingming Cao: make msgrcv/shmat check the queue/segment ID's properly
  - Greg KH: USB serial init failure fix, Xircom serial converter driver
  - Neil Brown: nsfd/raid/md/lockd cleanups
  - Ingo Molnar: multipath RAID personality, raid xor update
  - Hugh Dickins/Marcelo Tosatti: swapin read-ahead race fix
  - Vojtech Pavlik: fix up some of the infrastructure for x86-64
  - Robert Love: AMD 761 AGP GART support
  - Jens Axboe: fix SCSI-generic queue handling race
  - me: be sane about page reference bits

  - Christoph Hellwig: clean up personality handling a bit
  - Robert Love: update sysctl/vm documentation
  - make the three-argument (that everybody hates) "min()" be "min_t()",
  and introduce a type-anal "min()" that complains about arguments of
  different types.

  - Alan Cox: big driver/mips sync
  - Andries Brouwer, Christoph Hellwig: more gendisk fixups
  - Tobias Ringstrom: tulip driver workaround for DC21143 erratum

  - Jens Axboe: remove trivially dead io_request_lock usage
  - Andrea Arcangeli: softirq cleanup and ARM fixes. Slab cleanups
  - Christoph Hellwig: gendisk handling helper functions/cleanups
  - Nikita Danilov: reiserfs dead code pruning
  - Anton Altaparmakov: NTFS update to 1.1.18
  - firestream network driver: patch reverted on authors request
  - NIIBE Yutaka: SH architecture update
  - Paul Mackerras: PPC cleanups, PPC8xx update.
  - me: reverse broken bootdata allocation patch that went into pre5

  - Johannes Erdfelt, Oliver Neukum: USB printer driver race fix
  - John Byrne: fix stupid i386-SMP irq stack layout bug
  - Andreas Bombe, me: yenta IO window fix
  - Neil Brown: raid1 buffer state fix
  - David Miller, Paul Mackerras: fix up sparc and ppc respectively for kmap/kbd_rate
  - Matija Nalis: umsdos fixes, and make it possible to boot up with umsdos
  - Francois Romieu: fix bugs in dscc4 driver
  - Andy Grover: new PCI config space access functions (eventually for ACPI)
  - Albert Cranford: fix incorrect e2fsprog data from ver_linux script
  - Dave Jones: re-sync x86 setup code, fix macsonic kmalloc use
  - Johannes Erdfelt: remove obsolete plusb USB driver
  - Andries Brouwer: fix USB compact flash version info, add blksize ioctls

  - me: fix more buffer head SMP races (non-x86 only - weak memory ordering)
  - Andrea Arkangeli: some bh cleanups from the buffer race condition fix
  - Tim Waugh: parport drievr documentation, init sanity
  - Ion Badulescu: starfire net driver update
  - David Miller: sparc and networking updates
  - Ivan Kokshaysky: alpha version of the inlined rw-semaphores
  - NIIBE Yutaka: SuperH update

  - David Miller: sparc and networking updates
  - Al Viro: SysV FS add_link off-by-two bogosity.
  - Jeff Garzik: merge D-Link DL2k GigE driver, other network driver cleanups
  - Kai Germaschewski: ISDN update
  - Alan Cox: more merging (MPT fusion core)
  - Johannes Erdfelt: USB updates
  - Stas Sergeev: make sure we return out of vm86 mode when interrupts
  get re.enabled
  - Rusty Russell: netfilter fixes for ipt_unclean and ip_queue
  - me: initialize page->age when adding it to the swap cache
  - Paul Mackerras: PPC updates
  - some subtle fs/buffer.c race conditions (Andrew Morton, me)