All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use blk_queue_dead() to test whether the queue is dead instead
of !sdev. Since scsi_prep_fn() may be invoked concurrently with
__scsi_remove_device(), keep the queuedata (sdev) pointer in
__scsi_remove_device(). This patch fixes a kernel oops that
can be triggered by USB device removal. See also
http://www.spinics.net/lists/linux-scsi/msg56254.html.

Other changes included in this patch:
- Swap the blk_cleanup_queue() and kfree() calls in
  scsi_host_dev_release() to make that code easier to grasp.
- Remove the queue dead check from scsi_run_queue() since the
  queue state can change anyway at any point in that function
  where the queue lock is not held.
- Remove the queue dead check from the start of scsi_request_fn()
  since it is redundant with the scsi_device_online() check.
Reported-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NTejun Heo <tj@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Initialize atomic_t scsi_host_next_hn and ioerr_cntas per the guidelines
defined in Documentation/atomic_ops.txt
Signed-off-by: NJosh Hunt <johunt@akamai.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Commit 6f381fa3
Author: Lin Ming <ming.m.lin@intel.com>

[SCSI] scsi_lib: use correct DMA device in __scsi_alloc_queue
 
Caused a regression where we oops in every legacy mode SCSI host driver
because they supply a NULL pointer to scsi_add_host().  Fix this by checking
for the NULL in scsi_add_host_with_dma() and changing the DMA device to being
the platform_bus in that case (which replicates the original behaviour).
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Make sure that SCSI device removal via scsi_remove_host() does finish
all pending SCSI commands. Currently that's not the case and hence
removal of a SCSI host during I/O can cause a deadlock. See also
"blkdev_issue_discard() hangs forever if underlying storage device is
removed" (http://bugzilla.kernel.org/show_bug.cgi?id=40472). See also
http://lkml.org/lkml/2011/8/27/6.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Cc: <stable@kernel.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option,
but it keeps the logic around to handle block devices in the old manner
as some people like to run new kernel versions on old (pre 2007/2008)
distros.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.

Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.

Add support for honoring the integrity segment limit when merging both
bios and requests.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@carl.home.kernel.dk>

This patch (as1398b) adds runtime PM support to the SCSI layer.  Only
the machanism is provided; use of it is up to the various high-level
drivers, and the patch doesn't change any of them.  Except for sg --
the patch expicitly prevents a device from being runtime-suspended
while its sg device file is open.

The implementation is simplistic.  In general, hosts and targets are
automatically suspended when all their children are asleep, but for
them the runtime-suspend code doesn't actually do anything.  (A host's
runtime PM status is propagated up the device tree, though, so a
runtime-PM-aware lower-level driver could power down the host adapter
hardware at the appropriate times.)  There are comments indicating
where a transport class might be notified or some other hooks added.

LUNs are runtime-suspended by calling the drivers' existing suspend
handlers (and likewise for runtime-resume).  Somewhat arbitrarily, the
implementation delays for 100 ms before suspending an eligible LUN.
This is because there typically are occasions during bootup when the
same device file is opened and closed several times in quick
succession.

The way this all works is that the SCSI core increments a device's
PM-usage count when it is registered.  If a high-level driver does
nothing then the device will not be eligible for runtime-suspend
because of the elevated usage count.  If a high-level driver wants to
use runtime PM then it can call scsi_autopm_put_device() in its probe
routine to decrement the usage count and scsi_autopm_get_device() in
its remove routine to restore the original count.

Hosts, targets, and LUNs are not suspended while they are being probed
or removed, or while the error handler is running.  In fact, a fairly
large part of the patch consists of code to make sure that things
aren't suspended at such times.

[jejb: fix up compile issues in PM config variations]
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The below patch fixes a warning message generated by gcc 4.6.0
  CC      drivers/scsi/hosts.o
drivers/scsi/hosts.c: In function 'scsi_host_alloc':
drivers/scsi/hosts.c:328:6: warning: variable 'rval' set but not used

Fix this by removing the rval but placing a printk warning where it
would have been set.
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
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>

Set power.async_suspend for all SCSI devices, targets and hosts, so
that they can be suspended and resumed in parallel with the main
suspend/resume thread and possibly with other devices they don't
depend on in a known way (i.e. devices which are not their parents or
children).

The power.async_suspend flag is also set for devices that don't have
suspend or resume callbacks, because otherwise they would make the
main suspend/resume thread wait for their "asynchronous" children
(during suspend) or parents (during resume), effectively negating the
possible gains from executing these devices' suspend and resume
callbacks asynchronously.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Some of our virtual SCSI hosts don't have a proper bus parent at the
top, which can be a problem for doing DMA on them

This patch makes the host device cache a pointer to the physical bus
device and provides an extra API for setting it (the normal API picks
it up from the parent).  This patch also modifies the qla2xxx and lpfc
vport logic to use the new DMA host setting API.
Acked-By: NJames Smart  <james.smart@emulex.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

__scsi_remove_device() in scsi_forget_host() is executed out of scan_mutex
and races with scsi_destroy_sdev() <- scsi_sysfs_add_devices() <-
scsi_finish_async_scan().  The result is use after free and/or double
free, oops.

The fix is simple, move scsi_forget_host() under scan_mutex.

scsi_forget_host() is just sequence of __scsi_remove_device().  All
another calls of __scsi_remove_device() are made under scan_mutex.  So
that it is safe.
Signed-off-by: NAlexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Just once, two fcoe instances got the same host number
from scsi_add_host().

Use atomic_t and atomic_inc_return() to get next host number.
Subtract 1, so that scsi_host still starts with 0.

[jejb: added comment about unusual subtraction]
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The SCSI core calls scsi_proc_hostdir_add() from within
scsi_host_alloc(), but the corresponding scsi_proc_hostdir_rm()
routine is called from within scsi_remove_host().  As a result, if a
host is allocated and then deallocated without ever being registered,
the host's directory in /proc is leaked.

This patch (as1181b) fixes this bug in the SCSI core by moving
scsi_proc_hostdir_rm() into scsi_host_dev_release().
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.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>

This patch cleans up the behavior of scsi_host_lookup().

The original implementation attempted to use the dual role of
either returning a pointer value, or a negative error code.
User's needed to use IS_ERR() to check the result. Additionally,
the IS_ERR() macro never checks for when a NULL pointer was
returned, so a NULL pointer actually passes with a success case.
Note: scsi_host_get(), used by scsi_host_lookup(), can return
a NULL pointer.

Talk about a mudhole for the unitiated to step into....

This patch converts scsi_host_lookup() to return either NULL
or a valid pointer. The consumers were updated for the change.
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Kobjects do not have a limit in name size since a while, so stop
pretending that they do.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This mirrors the functionality that driver_find_device has as well.

We add a start variable, and all callers of the function are fixed up at
the same time.

The block layer will be using this new functionality in a follow-on
patch.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make the needlessly global struct scsi_{host,target}_type static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

commit 9c770108
Author: Dave Young <hidave.darkstar@gmail.com>
Date:   Tue Jan 22 14:01:34 2008 +0800

    scsi: use class iteration api

Isn't a correct replacement for the original hand rolled host
lookup. The problem is that class_find_child would get a reference to
the host's class device which is never released.  Since the host class
device holds a reference to the host gendev, the host can never be
freed.

In 2.6.26 we started using class_find_device, and this function also
gets a reference to the device, so we end up with an extra ref
and the host will not get released.

This patch adds a put_device to balance the class_find_device() get. I
kept the scsi_host_get in scsi_host_lookup, because the target layer
is using scsi_host_lookup and it looks like it needs the SHOST_DEL
check.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We're getting a WARN_ON from SLUB indicating that we're trying to free
caches with in-use objects.  The root cause is a new dependency in the
command/sense free on unchecked_isa_dma.  The WARN_ON is caused by
drivers which change this in their setup after the command/sense cache
is allocated.

The fix is to move the allocation of this cache into scsi_add_host()
so things like gdth have an opportunity to modify it between alloc and
add (but *not* after).

The true fix would be to move unchecked_isa_dma into the template and
out of the host, so it because a truly read only variable.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch removes the unused sysfs attibute overwriting logic for
the scsi host attibutes, and plugs them into the driver core default
attribute creation.
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>

This patch implements scsi_host and scsi_target device types
and adds both to the scsi_bus.
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>

It's big, but there doesn't seem to be a way to split it up smaller...
Signed-off-by: NTony Jones <tonyj@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In the following if/else statement, shost->active_mode will always be set,
so this assignment is unneeded.
Signed-off-by: NDenis Cheng <crquan@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch corrects some cases in scsi_add_host() that fail, but the "error"
return code was not reset after a prior use which set it to a non-error value.

Patch cut against scsi-rc-fixes-2.6
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

With the sg table code, every SCSI driver is now either chain capable
or broken (or has sg_tablesize set so chaining is never activated), so
there's no need to have a check in the host template.

Also tidy up the code by moving the scatterlist size defines into the
SCSI includes and permit the last entry of the scatterlist pools not
to be a power of two.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Convert to use the class iteration api.
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Only hosts which actually have ISA DMA requirements need sense buffers
coming out of ZONE_DMA, so only use the __GFP_DMA flag for that case
to avoid allocating this scarce resource if it's not necessary.

[tomo: fixed slab leak in failure case]
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This removes static array sense_buffer in scsi_cmnd and uses
dynamically allocated sense_buffer (with GFP_DMA).

The reason for doing this is that some architectures need cacheline
aligned buffer for DMA:

http://lkml.org/lkml/2007/11/19/2

The problems are that scsi_eh_prep_cmnd puts scsi_cmnd::sense_buffer
to sglist and some LLDs directly DMA to scsi_cmnd::sense_buffer. It's
necessary to DMA to scsi_cmnd::sense_buffer safely. This patch solves
these issues.

__scsi_get_command allocates sense_buffer via kmem_cache_alloc and
attaches it to a scsi_cmnd so everything just work as before.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update
lots of kerneldoc comments in drivers/scsi/*.

Updated with comments from Stefan Richter, Stephen M. Cameron,
 James Bottomley and Randy Dunlap.
Signed-off-by: NRob Landley <rob@landley.net>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

if shost->supported mode is zero (i.e. MODE_UNKNOWN) show it as
initiator (it's obviously an unconverted driver that won't do target).
Acked-by: NFUJITA Tomonori <tomof@acm.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This option is true if a low-level driver can support sg
chaining. This will be removed eventually when all the drivers are
converted to support sg chaining. q->max_phys_segments is set to
SCSI_MAX_SG_SEGMENTS if false.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

This adds supported_mode and active_mode attributes to
/sys/class/sys_host/hostX/ for specifying the mode that a lld supports
and the currently activated mode. The output format is similar to fc
rport roles:

luce:/sys/class/scsi_host/host0$ cat supported_mode
Initiator
luce:/sys/class/scsi_host/host0$ cat active_mode
Initiator

The mode values uses bitmap since we would support dual-mode llds in
the future like this:

luce:/sys/class/scsi_host/host0$ cat supported_mode
Initiator, Target

The supported_mode attribute looks at a scsi_host_template and the
active_mode attribute looks at a scsi_host. We would add a hook to a
scsi_host_template to change the active_mode attribute
dynamically. But now there is no hook since no lld supports that
feature.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

It's better to initialize host->shost_data to zero like
target->starget_data and device->sdev_data.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

SCSI was using the incorrect lock to protect walking the list of all
devices in the class.  This patch fixes this.

Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch contains the needed changes to the scsi-ml for the target
mode support.

Note, per the last review we moved almost all the fields we added
to the scsi_cmnd to our internal data structure which we are going
to try and kill off when we can replace it with support from other
parts of the kernel.

The one field we left on was the offset variable. This is needed to handle
the case where the target gets request that is so large that it cannot
execute it in one dma operation. So max_secotors or a segment limit may
limit the size of the transfer. In this case our tgt core code will
break up the command into managable transfers and send them to the
LLD one at a time. The offset is then used to tell the LLD where in
the command we are at. Is there another field on the scsi_cmd for
that?
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

scsi_assign_lock has been unused for a long time and is a bad idea
in general, so kill it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds support for sharing tag maps at the host level
(i.e. either every queue [LUN] has its own tag map or there's a single
one for the entire host).  This formulation is primarily intended to
help single issue queue hardware, like the aic7xxx
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>