We have been seeing the flush request timeout with a wide
range of hardware from tgt+iser to FC targets from a major vendor.

After discussions about if the value should be configurable and
what the best value should be, this patch just increases the flush/sync
cache timeout to 1 minute. 2 minutes was determined to be too long, and
making it configurable was troublesome for users.

This patch was made over Linus's tree. It is not made over scsi-misc
or scsi-rc-fixes, because Linus's had block layer changes that my
patch was built over.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Acked-by: NJens Axboe <jaxboe@fusionio.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

In sd_store_cache_type the symbol 'len' is declared twice.  Remove the
second declaration to quiet the following sparse warning.

warning: symbol 'len' shadows an earlier one

In sd_probe the variable 'index' is declared as a u32.  This variable is
used in a call to ida_get_new which is expecting an int *.  Make the
variable an int to quiet the following sparse warning.

warning: incorrect type in argument 2 (different signedness)

There are 4 symbols in the file that are not exported and produce
the following sparse warnings.

warning: symbol 'sd_cdb_cache' was not declared. Should it be static?
warning: symbol 'sd_cdb_pool' was not declared. Should it be static?
warning: symbol 'sd_read_protection_type' was not declared. Should it be static?
warning: symbol 'sd_read_app_tag_own' was not declared. Should it be static?

Make them static to quiet the warnings.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scsi-ml uses REQ_TYPE_BLOCK_PC for flush requests from file
systems. The definition of REQ_TYPE_BLOCK_PC is that we don't retry
requests even when we can (e.g. UNIT ATTENTION) and we send the
response to the callers (then the callers can decide what they want).
We need a workaround such as the commit
77a42297 to retry BLOCK_PC flush
requests. We will need the similar workaround for discard requests too
since SCSI-ml handle them as BLOCK_PC internally.

This uses REQ_TYPE_FS for flush requests from file systems instead of
REQ_TYPE_BLOCK_PC.

scsi-ml retries only REQ_TYPE_FS requests that have data to
transfer when we can retry them (e.g. UNIT_ATTENTION). However, we
also need to retry REQ_TYPE_FS requests without data because the
callers don't.

This also changes scsi_check_sense() to retry all the REQ_TYPE_FS
requests when appropriate. Thanks to scsi_noretry_cmd(),
REQ_TYPE_BLOCK_PC requests don't be retried as before.

Note that basically, this reverts the commit
77a42297 since now we use REQ_TYPE_FS
for flush requests.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Jens, any reason why this isn't included in your for-2.6.36 yet?

=
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Subject: [PATCH resend] scsi: convert discard to REQ_TYPE_FS from REQ_TYPE_BLOCK_PC

The block layer (file systems) sends discard requests as REQ_TYPE_FS
(the role of REQ_TYPE_FS is that setting up commands and interpreting
the results). But SCSI-ml treats discard requests as
REQ_TYPE_BLOCK_PC.

scsi-ml can handle discard requests as REQ_TYPE_FS
easily. scsi_setup_discard_cmnd() sets up struct request and the bio
nicely. Only remaining issue is that discard requests can't be
completed partially so we need to modify sd_done.

This conversion also fixes the problem that discard requests aren't
retried when possible (e.g. UNIT ATTENTION).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Every user of the BKL in the sd driver is the
result of the pushdown from the block layer
into the open/close/ioctl functions.

The only place that used to rely on the BKL is
the sdkp->openers variable, which gets converted
into an atomic_t.

Nothing else seems to rely on the BKL, since the
functions do not touch global data without holding
another lock, and the open/close functions are
still protected from concurrent execution using
the bdev->bd_mutex.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

We leak a page allocated for discard on some error conditions
(e.g. scsi_prep_state_check returns BLKPREP_DEFER in
scsi_setup_blk_pc_cmnd).

We unprep on requests that weren't prepped in the error path of
scsi_init_io. It makes the error path to clean up scsi commands messy.

Let's strictly apply the rule that we can't unprep on a request that
wasn't prepped.

Calling just scsi_put_command() in the error path of scsi_init_io() is
enough. We don't set REQ_DONTPREP yet.

scsi_setup_discard_cmnd can safely free a page on the error case with
the above rule.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This is for block's for-2.6.36.

We need to reset q->unprep_rq_fn in sd_remove. Otherwise we hit kernel
oops if we access to a scsi disk device via sg after removing scsi
disk module.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This removes q->prepare_flush_fn completely (changes the
blk_queue_ordered API).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

scsi-ml builds flush requests via q->prepare_flush_fn(), however,
builds discard requests via q->prep_rq_fn.

Using two different mechnisms for the similar requests (building
commands in SCSI ULD) doesn't make sense.

Handing both via q->prep_rq_fn makes the code design simpler.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

- sd_done isn't called for pc request so we never call the code.
- we use sd_unprep to free discard page now.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This fixes discard page leak by using q->unprep_rq_fn facility.

q->unprep_rq_fn is called when all the data buffer (req->bio and
scsi_data_buffer) in the request is freed.

sd_unprep() uses rq->buffer to free discard page allocated in
sd_prepare_discard().
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Allocating a fixed payload for discard requests always was a horrible hack,
and it's not coming to byte us when adding support for discard in DM/MD.

So change the code to leave the allocation of a payload to the lowlevel
driver.  Unfortunately that means we'll need another hack, which allows
us to update the various block layer length fields indicating that we
have a payload.  Instead of hiding this in sd.c, which we already partially
do for UNMAP support add a documented helper in the core block layer for it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This patch (as1399) adds runtime-PM support to the sd driver.  The
support is unsophisticated: If a SCSI disk device is mounted, or if
its device file is held open, then the device will not be
runtime-suspended; otherwise it will (provided userspace gives
permission by writing "auto" to the sysfs power/control attribute).

In order to make this work, a dev_set_drvdata() call had to be moved
from sd_probe_async() to sd_probe().  Also, a few lines of code were
changed to use a local variable instead of recalculating the address
of an embedded struct device.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Implement sd_unlock_native_capacity() method which calls into
hostt->unlock_native_capacity() if implemented.  This will be invoked
by block layer if partitions extend beyond the end of the device and
can be used to implement, for example, on-demand ATA host protected
area unlocking.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Some arrays are giving I/O errors with ext3 filesystems when
SYNCHRONIZE_CACHE gets a UNIT_ATTENTION.  What is happening is that
these commands have no retries, so the UNIT_ATTENTION causes the
barrier to fail.  We should be enable retries here to clear any
transient error and allow the barrier to succeed.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Hazard testing uncovered yet another bug in sd. Under heavy reset
activity the retry counter might be exhausted and the command will be
returned with sense UNIT_ATTENTION/0x29/00 (POWER ON, RESET, OR BUS
DEVICE RESET OCCURRED). In those cases we should just increase the
retry counter again, retrying one more to clear up this Unit Attention
state.

[jejb: update to work with RC16 devices and not to loop endlessly]
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

sd always tries to submit a READ_CAPACITY(16) CDB,
regardless whether the host actually supports it.
queuecommand() will then return DID_ABORT, which is
not qualified enough to detect the true cause here.
So better check in sd_try_rc16 first if the cdblen
is supported.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

This flag is not used, so best discarded.
Signed-off-by: NNeilBrown <neilb@suse.de>
--
Hi Jens,
 I came across this recently - these are the only two occurances
 of "GENHD_FL_DRIVERFS" in the kernel, so it cannot be needed.
NeilBrown
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Commit e3deec09 incorrectly assumed that the B0 and B1 page lengths were
limited to 32 bytes.  The B0 VPD page length is defined to be 64 bytes
when the device supports thin provisioning.  B1 is always defined to be
64 bytes.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reported-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Having the large CDB allocation logic in sd.c means that
scsi_io_completion does not have access to the command buffer. That in
turn causes garbage to be printed when a 32-byte command fails. Move the
command printing to sd_done where the command buffer is intact.  Clear
the command buffer pointer after the extended CDB has been freed.

Make scsi_print_command ignore commands with NULL CDB pointers to
inhibit printing of garbled command strings.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.
Signed-off-by: NDaniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

DIF and DIX errors are handled identically at this point.  Collapse the
switch cases into one and let scsi_io_completion print result and sense
data.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The best way to fix this is to eliminate the intenal kmalloc() and
make the caller allocate the required amount of storage.
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Implement a function for handling discard requests that sends either
WRITE SAME(16) or UNMAP(10) depending on parameters indicated by the
device in the block limits VPD.

Extract unmap constraints and report them to the block layer.

Based in part by a patch by Christoph Hellwig <hch@lst.de>.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Disks formatted with DIF Type 2 reject READ/WRITE 6/10/12/16 commands
when protection is enabled.  Only the 32-byte variants are supported.

Implement support for issusing 32-byte READ/WRITE and enable Type 2
drives in the protection type detection logic.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

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>