linux-toradex.git/drivers/scsi/scsi_dh.c, branch v4.9.43

scsi: use 'scsi_device_from_queue()' for scsi_dh

2017-03-12T05:41:45+00:00

commit 857de6e00778738dc3d61f75acbac35bdc48e533 upstream.

The device handler needs to check if a given queue belongs to a scsi
device; only then does it make sense to attach a device handler.

[mkp: dropped flags]

Signed-off-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

scsi: Replace wrong device handler name for CLARiiON arrays

2016-10-11T21:56:51+00:00

At drivers/scsi/device_handler/scsi_dh_emc.c it was defined as:

Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Christophe Varoqui 
Cc: James E.J. Bottomley 
Cc: Martin K. Petersen 
Cc: SCSI ML 
Cc: device-mapper development 
Signed-off-by: Xose Vazquez Perez 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi_dh: move 'dh_state' sysfs attribute to generic code

2015-12-02T21:29:19+00:00

As scsi_dh.c is now always compiled in we should be moving
the 'dh_state' attribute to the generic code.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi_dh: don't try to load a device handler during async probing

2015-10-27T06:03:31+00:00

Request_module gets really unhappy when called from async probing, so
revert to not auto load device handler modules during the SCSI bus
scan.  While autoloading would be really useful we never did this
until 4.3-rc and it turns out that functionality doesn't actually
work.

Fixes: 566079 ("dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath")
Signed-off-by: Christoph Hellwig 
Reported-by: Paul Mackerras 
Tested-by: Paul Mackerras 
Signed-off-by: James Bottomley

scsi_dh: fix use-after-free when removing scsi device

2015-10-27T02:22:37+00:00

The commit 1bab0de0274f ("dm-mpath, scsi_dh: don't let dm detach device
handlers") removed reference counting of attached scsi device handler.
As a result, handler data is freed immediately via scsi_dh->detach()
in the context of scsi_remove_device() where activation request can be
still in flight.

This patch moves scsi_dh_handler_detach() to sdev releasing function,
scsi_device_dev_release_usercontext(), at that point the device
is already in quiesced state.

Fixes: 1bab0de0274f ("dm-mpath, scsi_dh: don't let dm detach device handlers")
Signed-off-by: Jun'ichi Nomura 
Acked-by: Christoph Hellwig 
Signed-off-by: James Bottomley

scsi_dh: Use the correct module name when loading device handler

2015-10-01T17:46:28+00:00

This fixes a bug in recent kernels which results in failure to boot
on systems that have multipath SCSI disks.  I observed this failure
on a POWER8 server where all the disks are multipath SCSI disks.
The symptoms are several messages like this on the console:

[    3.018700] device-mapper: table: 253:0: multipath: error attaching hardware handler
[    3.018828] device-mapper: ioctl: error adding target to table

and the system does not find its disks, and therefore fails to boot.

Bisection revealed that the bug was introduced in commit 566079c849cf,
"dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath".
The specific reason for the failure is that where we previously loaded
the "scsi_dh_alua" module, we are now trying to load the "alua" module,
which doesn't exist.

To fix this, we change the request_module call in scsi_dh_lookup()
to prepend "scsi_dh_" to the name, just like the old code in
drivers/md/dm-mpath.c:parse_hw_handler() used to do.

[jejb: also fixes issue spotted by Sasha Levin that formatting
characters could be passed in via sysfs and cause issues with
request_module()]

Fixes: 566079c849cf
Signed-off-by: Paul Mackerras 
Cc: Sasha Levin 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Signed-off-by: James Bottomley

scsi_dh: return SCSI_DH_NOTCONN in scsi_dh_activate()

2015-08-28T20:14:58+00:00

When calling scsi_dh_activate() we should be returning
SCSI_DH_NOTCONN if the device handler couldn't be attached.

Reviewed-by: Bart van Assche 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Hannes Reinecke 
Signed-off-by: James Bottomley

scsi_dh: don't allow to detach device handlers at runtime

2015-08-28T20:14:58+00:00

The I/O submission and completion paths call into the device handler
without any synchronization agains detachment.  So disallow detaching
device handlers at runtime.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Signed-off-by: James Bottomley

scsi_dh: add a common helper to get a scsi_device from a request_queue

2015-08-28T20:14:57+00:00

And cleanup the various messy opencoded versions of this.  Note that this
moves the sdev_state checks outside the queue_lock coverage, but as
we don't hold the lock over the activation they are only advisory anyway.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Signed-off-by: James Bottomley

scsi_dh: kill struct scsi_dh_data

2015-08-28T20:14:57+00:00

Add a ->handler and a ->handler_data field to struct scsi_device and kill
this indirection.  Also move struct scsi_device_handler to scsi_dh.h so that
changes to it don't require rebuilding every SCSI LLDD.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Signed-off-by: James Bottomley