So far we have only issued DIF commands if CONFIG_BLK_DEV_INTEGRITY is
enabled.  However, communication between initiator and target should be
independent of protection information DMA.  There are DIF-only host
adapters coming out that will be able to take advantage of this.

Move the relevant DIF bits to sd.c.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Chris Webb reported:
  p0# uname -a
  Linux f7ea8425-d45b-490f-a738-d181d0df6963.host.elastichosts.com 2.6.30.4-elastic-lon-p #2 SMP PREEMPT Thu Aug 20 14:30:50 BST 2009 x86_64 Intel(R) Xeon(R) CPU E5420 @ 2.50GHz GenuineIntel GNU/Linux
  p0# zgrep SCAN_ASYNC /proc/config.gz
  # CONFIG_SCSI_SCAN_ASYNC is not set

  p0# cat /var/log/kern/2009-08-20
  [...]
  15:27:10.485 kernel: scsi9 : iSCSI Initiator over TCP/IP
  15:27:11.493 kernel: scsi 9:0:0:0: RAID              IET      Controller       0001 PQ: 0 ANSI: 5
  15:27:11.493 kernel: scsi 9:0:0:0: Attached scsi generic sg6 type 12
  15:27:11.495 kernel: scsi 9:0:0:1: Direct-Access     IET      VIRTUAL-DISK     0001 PQ: 0 ANSI: 5
  15:27:11.495 kernel: sd 9:0:0:1: Attached scsi generic sg7 type 0
  15:27:11.495 kernel: sd 9:0:0:1: [sdg] 4194304 512-byte hardware sectors: (2.14 GB/2.00 GiB)
  15:27:11.495 kernel: sd 9:0:0:1: [sdg] Write Protect is off
  15:27:11.495 kernel: sd 9:0:0:1: [sdg] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
  15:27:13.012 kernel: sdg:<6>scsi 9:0:0:1: [sdg] Unhandled error code
  15:27:13.012 kernel: scsi 9:0:0:1: [sdg] Result: hostbyte=0x07 driverbyte=0x00
  15:27:13.012 kernel: end_request: I/O error, dev sdg, sector 0
  15:27:13.012 kernel: Buffer I/O error on device sdg, logical block 0
  15:27:13.012 kernel: ldm_validate_partition_table(): Disk read failed.
  15:27:13.012 kernel: unable to read partition table
  15:27:13.014 kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
  15:27:13.014 kernel: IP: [<ffffffff803f0d77>] disk_part_iter_next+0x74/0xfd
  15:27:13.014 kernel: PGD 82ad0b067 PUD 82cd7e067 PMD 0 
  15:27:13.014 kernel: Oops: 0000 [#1] PREEMPT SMP 
  15:27:13.014 kernel: last sysfs file: /sys/devices/platform/host9/session4/iscsi_session/session4/ifacename
  15:27:13.014 kernel: CPU 5 
  15:27:13.014 kernel: Modules linked in:
  15:27:13.014 kernel: Pid: 13999, comm: async/0 Not tainted 2.6.30.4-elastic-lon-p #2 X7DBN
  15:27:13.014 kernel: RIP: 0010:[<ffffffff803f0d77>]  [<ffffffff803f0d77>] disk_part_iter_next+0x74/0xfd
  15:27:13.014 kernel: RSP: 0018:ffff88066afa3dd0  EFLAGS: 00010246
  15:27:13.014 kernel: RAX: ffff88082b58a000 RBX: ffff88066afa3e00 RCX: 0000000000000000
  15:27:13.014 kernel: RDX: 0000000000000000 RSI: ffff88082b58a000 RDI: 0000000000000000
  15:27:13.014 kernel: RBP: ffff88066afa3df0 R08: ffff88066afa2000 R09: ffff8806a204f000
  15:27:13.014 kernel: R10: 000000fb12c7d274 R11: ffff8806c2bf0628 R12: ffff88066afa3e00
  15:27:13.014 kernel: R13: ffff88082c829a00 R14: 0000000000000000 R15: ffff8806bc50c920
  15:27:13.014 kernel: FS:  0000000000000000(0000) GS:ffff88002818a000(0000) knlGS:0000000000000000
  15:27:13.014 kernel: CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
  15:27:13.014 kernel: CR2: 0000000000000010 CR3: 000000082ade3000 CR4: 00000000000426e0
  15:27:13.014 kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  15:27:13.014 kernel: DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  15:27:13.014 kernel: Process async/0 (pid: 13999, threadinfo ffff88066afa2000, task ffff8806c2bf05e0)
  15:27:13.014 kernel: Stack:
  15:27:13.014 kernel: 0000000000000000 ffff88066afa3e00 ffff88066afa3e00 ffff88082c829a00
  15:27:13.014 kernel: ffff88066afa3e40 ffffffff80306feb ffff88082b58a000 0000000000000000
  15:27:13.014 kernel: 0000000000000001 ffff8806bc50c920 ffff88066afa3e40 ffff88082b58a000
  15:27:13.014 kernel: Call Trace:
  15:27:13.014 kernel: [<ffffffff80306feb>] register_disk+0x122/0x13a
  15:27:13.014 kernel: [<ffffffff803f0b0f>] add_disk+0xaa/0x106
  15:27:13.014 kernel: [<ffffffff80493609>] sd_probe_async+0x198/0x25b
  15:27:13.014 kernel: [<ffffffff80270482>] async_thread+0x10c/0x20d
  15:27:13.014 kernel: [<ffffffff802545ff>] ? default_wake_function+0x0/0xf
  15:27:13.014 kernel: [<ffffffff80270376>] ? async_thread+0x0/0x20d
  15:27:13.014 kernel: [<ffffffff8026ad89>] kthread+0x55/0x80
  15:27:13.014 kernel: [<ffffffff8022be6a>] child_rip+0xa/0x20
  15:27:13.014 kernel: [<ffffffff8026ad34>] ? kthread+0x0/0x80
  15:27:13.014 kernel: [<ffffffff8022be60>] ? child_rip+0x0/0x20
  15:27:13.014 kernel: Code: c8 ff 80 e1 0c b9 00 00 00 00 0f 44 c1 41 83 cd ff 48 8d 7a 20 48 be ff ff ff ff 08 00 00 00 48 b9 00 00 00 00 08 00 00 00 eb 50 <8b> 42 10 41 bd 01 00 00 00 eb db 4c 63 c2 4e 8d 04 c7 4d 8b 20 
  15:27:13.015 kernel: RIP  [<ffffffff803f0d77>] disk_part_iter_next+0x74/0xfd
  15:27:13.015 kernel: RSP <ffff88066afa3dd0>
  15:27:13.015 kernel: CR2: 0000000000000010
  15:27:13.015 kernel: ---[ end trace 6104b56ef5590e25 ]---

The problem is caused because the async scanning split in sd.c doesn't hold
any reference to the device when it kicks off the async piece.  What's
happening is that an iSCSI disconnect is destorying the device again *before*
the async sd scanning thread even starts.  Fix this by taking a reference
before starting the thread and dropping it again when the thread completes.
Reported-by: NChris Webb <chris@arachsys.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Some USB devices crash when we send them an inquiry with the EVPD bit
set, regardless of page requested (i.e. including page 0).

We only need the extended inquiry to gain access to VPD pages 0xB0 and
0xB1.  These appeared in SBC2 and SBC3 respectively, so we can restrict
sending the extended inquiry to devices reporting SPC3 or higher.

This fixes bugzilla.kernel.org #13657.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
[jejb: added comment]
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

If a SCSI ULD driver sets blk_queue_prep_rq(), it should clean it
up itself on remove(), and not from the bus callbacks. This
removes the need to hook into bus->remove(), which should not
be used at the same time as driver->remove().

[jejb: fix sdkp initialisation problem due to mismerge]
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Query the block limits VPD page and adjust queue minimum and optimal I/O
sizes.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Detect non-rotational devices and set the queue flag accordingly.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Extract physical block size and lowest aligned LBA from READ
CAPACITY(16) response and adjust queue parameters.

Report physical block size and alignment when applicable.

[jejb: fix up trailing whitespace]
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The async split up of probing in sd.c created a potential failure case where
something goes wrong with device_add(), but which we don't recover properly.
Since, in general, asynchronous error handling is hard, move the device_add()
into the asynchronous path (it should be fast) and make sure all the deferred
processing cannot fail.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case.  The
sector size will be 4KB but the logical block size will remain
512-bytes.  Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

With recent cleanups, there is no place where low level driver
directly manipulates request fields.  This means that the 'hard'
request fields always equal the !hard fields.  Convert all
rq->sectors, nr_sectors and current_nr_sectors references to
accessors.

While at it, drop superflous blk_rq_pos() < 0 test in swim.c.

[ Impact: use pos and nr_sectors accessors ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Tested-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Tested-by: NAdrian McMenamin <adrian@mcmen.demon.co.uk>
Acked-by: NAdrian McMenamin <adrian@mcmen.demon.co.uk>
Acked-by: NMike Miller <mike.miller@hp.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Dario Ballabio <ballabio_dario@emc.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: unsik Kim <donari75@gmail.com>
Cc: Laurent Vivier <Laurent@lvivier.info>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Shifting an unsigned char implicitly casts it to a signed int.  This
caused 'lba' to sign-extend and Linux would then try READ CAPACITY 16
which was not supported by at least one drive.  Using the
get_unaligned_be*() helpers keeps us from having to worry about how the
extension might occur.
Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We have a problem with recovered error handling in that any command
which goes down as BLOCK_PC but which returns a sense code of RECOVERED
ERROR gets completed with -EIO.  For actual SG_IO commands, this doesn't
matter at all, since the error return code gets dropped in favour of
req->errors which contain the SCSI completion code.

However, if this command is part of the block system, then it will pay
attention to the returned error code.  In particularly if a SYNCHRONIZE
CACHE from a barrier command completes with RECOVERED ERROR, the
resulting -EIO on the barrier causes block to error the request and
return it to the filesystem.  Fix this by converting the -EIO for
recovered error to zero, plus remove the printing of this from sd and sr
so the message isn't double printed.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

sd_revalidate ends up being called several times during device setup.
With this patch we print everything during the first scan.  Subsequent
invocations will only print a message if the parameter in question has
actually changed (LUN capacity has increased, etc.).
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

New features are being added to the READ CAPACITY 16 results, so we
want to issue it in preference to READ CAPACITY 10.  Unfortunately, some
devices misbehave when they see a READ CAPACITY 16, so we restrict this
command to devices which claim conformance to SPC-3 (aka SBC-2), or claim
they have features which are only reported in the READ CAPACITY 16 data.

The READ CAPACITY 16 command is optional, even for SBC-2 devices, so
we fall back to READ CAPACITY 10 if READ CAPACITY 16 fails.

[jejb: don't error if device supports SBC-2 but doesn't support RC16]
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Tested-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The sd_read_capacity() function was about 180 lines long and
included a backwards goto and a tricky state variable.  Splitting out
read_capacity_10() and read_capacity_16() (about 50 lines each) reduces
sd_read_capacity to about 100 lines and gets rid of the backwards goto
and the state variable.  I've tried to avoid any behaviour change with
this patch.

[jejb: upped transfer request to standard recommended 32 for RC16]
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch (as1188) combines the tests for decrementing a drive's
reported capacity and expands the comment.  It also adds an
informational message to the system log, informing the user when the
reported value has been changed.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We currently try to spin up drives connected to standby and unavailable
ports.  This will never succeed and wastes a lot of time.  Fail quickly
if the sense data reports the port is in standby or unavailable state.
Reported-by: NNarayanan Rengarajan <narayanan.rengarajan@hp.com>
Tested-by: NNarayanan Rengarajan <narayanan.rengarajan@hp.com>
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Commit f27bac27 which converted sd to
use ida instead of idr incorrectly removed sd_index_lock around id
allocation and free.  idr/ida do have internal locks but they protect
their free object lists not the allocation itself.  The caller is
responsible for that.  This missing synchronization led to the same id
being assigned to multiple devices leading to oops.

Reported and tracked down by Stuart Hayes of Dell.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch makes part of the scsi probe (which is mostly device spin up and the
partition scan) asynchronous. Only the part that runs after getting the device
number allocated is asynchronous, ensuring that device numbering remains stable.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

[jejb: limit ioctl to returning 20 characters to avoid overrun
       on long device names and add a few more conversions]
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

scsi_execute() and scsi_execute_req() discard the residual length
information. Some callers need it. This adds residual argument
(optional) to scsi_execute and scsi_execute_req.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Update FMODE_NDELAY before each ioctl call so that we can kill the
magic FMODE_NDELAY_NOW.  It would be even better to do this directly
in setfl(), but for that we'd need to have FMODE_NDELAY for all files,
not just block special files.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When computing the full size of the device, we need to cast
sdkp->capacity before shifting, since in some configurations sector_t
can be a 32-bit number.

Also, change ffz(~x) to the more idiomatic ilog2(x).
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch (as1138) removes from sd.c some old code for switching from
10-byte commands to 6-byte commands.  This code is redundant -- the
switching for READ and WRITE is already handled in
scsi_io_completion() and the switching for MODE SENSE is already
handled in scsi_mode_sense().  (There is no comparable switch for MODE
SELECT, but I doubt one is needed.)

Furthermore the other handlers do a better job; they check for
appropriate ASC and ASCQ values before blindly switching the size.
The code in sd.c is known to cause problems with some devices by
switching when it shouldn't.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The current handling of NO_SENSE check condition is the same as
RECOVERED_ERROR, and assumes that in both cases, the I/O was fully
transferred.

We have seen cases of arrays returning with NO_SENSE (no error), but
the I/O was not completely transferred, thus residual set.  Thus,
rather than return good_bytes as the entire transfer, set good_bytes
to 0, so that the midlayer then applies the residual in calculating
the transfer, and for sd, will fail the I/O and fall into a retry
path.
Signed-off-by: NJamie Wellnitz <Jamie.Wellnitz@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

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

To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
	1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both.  That's this changeset.
	2) for each driver convert to new methods.  *ALL* drivers
are converted in this series.
	3) kill the old (renamed) methods.

Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain.  The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.

New methods:
	open(bdev, mode)
	release(disk, mode)
	ioctl(bdev, mode, cmd, arg)		/* Called without BKL */
	compat_ioctl(bdev, mode, cmd, arg)
	locked_ioctl(bdev, mode, cmd, arg)	/* Called with BKL, legacy */
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

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

store needed information in f_mode
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The old detection code couldn't handle all possible combinations of
DIX and DIF.  This version does, giving priority to DIX if the
controller is capable.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Now that we no longer use protection_type as trigger for preparing
protected CDBs we can remove the places that set it to zero.  This
allows userland to see which protection type the device is formatted
with regardless of whether the HBA supports DIF or not.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Use the same logic to prepare RD/WRPROTECT and the protection
operation.  Fixes a corner case where we could issue an unprotected
CDB and yet tell the HBA to do DIF to the drive.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: NMike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Modify the SCSI disk driver to call the revalidate_disk()
wrapper. This allows us to do some housekeeping such as accounting for
a disk being resized online. The wrapper will call
sd_revalidate_disk() at the appropriate time.
Signed-off-by: NAndrew Patterson <andrew.patterson@hp.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Now that disk and partition handlings are mostly unified, it's easy to
allow disk to have extended device number.  This patch makes
add_disk() use extended device number if disk->minors is zero.  Both
sd and ide-disk are updated to use this.

* sd_format_disk_name() is implemented which can generically determine
  the drive name.  This removes disk number restriction stemming from
  limited device names.

* If sd index goes over SD_MAX_DISKS (which can be increased now BTW),
  sd simply doesn't initialize minors letting block layer choose
  extended device number.

* If CONFIG_DEBUG_EXT_DEVT is set, both sd and ide-disk always set
  minors to 0 and use extended device numbers.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

With previous changes, it's meaningless to limit the number of
partitions.  Replace @ext_minors with GENHD_FL_EXT_DEVT such that
setting the flag allows the disk to have maximum number of allowed
partitions (only limited by the number of entries in parsed_partitions
as determined by MAX_PART constant).

This kills not-too-pretty alloc_disk_ext[_node]() functions and makes
@minors parameter to alloc_disk[_node]() unnecessary.  The parameter
is left alone to avoid disturbing the users.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Extended devt introduces non-contiguos device numbers.  This patch
implements a debug option which forces most devt allocations to be
from the extended area and spreads them out.  This is enabled by
default if DEBUG_KERNEL is set and achieves...

1. Detects code paths in kernel or userland which expect predetermined
   consecutive device numbers.

2. When something goes wrong, avoid corruption as adding to the minor
   of earlier partition won't lead to the wrong but valid device.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Update sd and ide-disk such that they can take advantage of extended
minors.

ide-disk already has 64 minors per device and currently doesn't use
extended minors although after this patch it can be turned on by
simply tweaking constants.

sd only had 16 minors per device causing problems on certain peculiar
configurations.  This patch lifts the restriction and enables it to
use upto 64 minors.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>