linux-stable.git/drivers/scsi/device_handler, branch linux-2.6.38.y

scsi_dh: fix reference counting in scsi_dh_activate error path

2011-05-09T22:06:35+00:00

commit 0b8393578c70bc1f09790eeae7d918f38da2e010 upstream.

Commit db422318cbca55168cf965f655471dbf8be82433 ([SCSI] scsi_dh:
propagate SCSI device deletion) introduced a regression where the device
reference is not dropped prior to scsi_dh_activate's early return from
the error path.

Signed-off-by: Mike Snitzer 
Reviewed-by: Mike Christie 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

scsi_dh_alua: fix deadlock in stpg_endio

2011-03-23T20:04:03+00:00

commit ed0f36bc5719b25659b637f80ceea85494b84502 upstream.

The use of blk_execute_rq_nowait() implies __blk_put_request() is needed
in stpg_endio() rather than blk_put_request() -- blk_finish_request() is
called with queue lock already held.

Signed-off-by: Joseph Gruher 
Signed-off-by: Ilgu Hong 
Signed-off-by: Mike Snitzer 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

[SCSI] scsi_dh: propagate SCSI device deletion

2010-12-21T18:37:27+00:00

Currently, when scsi_dh_activate() returns with an error
(e.g. SCSI_DH_NOSYS) the activate_complete callback is not called and
the error is not propagated to DM mpath.

When a SCSI device attached to a device handler is deleted, userland
processes currently performing I/O on the device will have their I/O
hang forever.

- Set SCSI_DH_NOSYS error when the handler is in the process of being
  deleted (e.g. the SCSI device is in a SDEV_CANCEL or SDEV_DEL state).

- Set SCSI_DH_DEV_OFFLINED error when device is in SDEV_OFFLINE state.

- Call the activate_complete callback function directly from
  scsi_dh_activate if an error has been set (when either the scsi_dh
  internal data has already been deleted or is in the process of being
  deleted).

The patch was tested in an iSCSI environment, RDAC H/W handler and
multipath.  In the following reproduction process, dd will I/O hang
forever and the only way to release it will be to reboot the machine:
1) Perform I/O on a multipath device:
    dd if=/dev/dm-0 of=/dev/zero bs=8k count=1000000 &
2) Delete all slave SCSI devices contained in the mpath device:
   I)  In an iSCSI environment, the easiest way to do this is by
   stopping iSCSI:
       /etc/init.d/iscsi stop
   II) Another way to delete the devices is by applying the following
   bash scriptlet:
       dm_devs=$(ls /sys/block/ | grep dm- | xargs)
       for dm_dev in $dm_devs; do
         devices=$(ls /sys/block/$dm_dev/slaves)
         for device in $devices; do
            echo 1 > /sys/block/$device/device/delete
         done
       done

NOTE: when DM mpath's fail_path uses blk_abort_queue this scsi_dh change
isn't strictly required.  However, DM mpath's call to blk_abort_queue
will soon be reverted because it has proven to be unsafe due to a race
(between blk_abort_queue and scsi_request_fn) that can lead to list
corruption.  Therefore we cannot rely on blk_abort_queue via fail_path,
but even if we could this scsi_dh change is still preferrable.

Signed-off-by: Menny Hamburger 
Signed-off-by: Mike Snitzer 
Reviewed-by: Babu Moger 
Signed-off-by: James Bottomley

[SCSI] scsi_dh_rdac: Add two new SUN devices to rdac_dev_list

2010-10-25T21:13:24+00:00

Signed-off-by: Vijay Chauhan 
Acked-by: Chandra Seetharaman 
Signed-off-by: James Bottomley

[SCSI] scsi_dh_alua: Handle all states correctly

2010-10-07T22:22:22+00:00

For ALUA we should be handling all states, independent of whether
the mode is explicit or implicit. For 'Transitioning' we should retry
for a certain amount of time; after that we're setting the port
to 'Standby' and return SCSI_DH_RETRY to signal upper layers
a retry is in order here.

Signed-off-by: Hannes Reinecke 
Acked-by: Mike Snitzer 
Signed-off-by: James Bottomley

[SCSI] scsi_dh_rdac: Add Dell MD36xxi controller into RDAC device list

2010-07-28T14:05:43+00:00

This patch is to add next generation of Dell iSCSI PowerVault
controller MD36xxi into RDAC device list.

Signed-off-by: Yanqing Liu 
Signed-off-by: James Bottomley

[SCSI] scsi_dh_emc: request flag cleanup

2010-04-11T19:04:02+00:00

blk_get_request sets the cmd_flags, so we should not and do not
need to set them. If we did set them to a different value then
it can cause a oops in the elevator code.

Signed-off-by: Mike Christie 
Signed-off-by: James Bottomley

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

2010-03-30T13:02:32+00:00

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: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

[SCSI] scsi_dh_emc: fix mode select request setup

2010-03-03T10:30:11+00:00

This patch fixes the request setup code for mode selects. I got the fixes from
Hannes Reinecke while trying to hunt down some problems and merged it
into one patch. I am sending it because Hannes is busy with other things.

The patch fixes:
- setting of the length for mode selects.
- setting of the data direction for mode select 10.

Signed-off-by: Hannes Reinecke 
Signed-off-by: Mike Christie 
Signed-off-by: James Bottomley

[SCSI] scsi_dh_alua: Add IBM Power Virtual SCSI ALUA device to dev list

2010-02-19T16:52:54+00:00

Adds IBM Power Virtual SCSI ALUA devices to the ALUA device handler.

Signed-off-by: Brian King 
Signed-off-by: James Bottomley