linux-toradex.git/include/scsi/scsi_dh.h, branch v4.4.65

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

scsi_dh: integrate into the core SCSI code

2015-08-28T20:14:56+00:00

Stop building scsi_dh as a separate module and integrate it fully into the
core SCSI code with explicit callouts at bus scan time.  For now the
callouts are placed at the same point as the old bus notifiers were called,
but in the future we will be able to look at ALUA INQUIRY data earlier on.

Note that this also means that the device handler modules need to be loaded
by the time we scan the bus.  The next patches will add support for
autoloading device handlers at bus scan time to make sure they are always
loaded if they are enabled in the kernel config.

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

dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath

2015-08-28T20:14:55+00:00

This way we can reused the same code any attachment method, not just those
requested from dm-mpath.

[jejb: fixup checkpatch error]
Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Acked-by: Mike Snitzer 
Signed-off-by: James Bottomley

dm-mpath, scsi_dh: don't let dm detach device handlers

2015-08-28T20:14:54+00:00

While allowing dm-mpath to attach device handlers is a functionality we need
for backwards compatibility reason there is no reason to reference count
them and detach them if dm-mpath stops using the device for some reason.

If the device handler works for the given device it can just stay attached,
and we can take the retain_hw_handler codepath.

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

[SCSI] scsi_dh: add scsi_dh_attached_handler_name

2012-07-20T07:58:42+00:00

Introduce scsi_dh_attached_handler_name() to retrieve the name of the
scsi_dh that is attached to the scsi_device associated with the provided
request queue.  Returns NULL if a scsi_dh is not attached.

Also, fix scsi_dh_{attach,detach} function header comments to document
@q rather than @sdev.

Signed-off-by: Mike Snitzer 
Tested-by: Babu Moger 
Reviewed-by: Chandra Seetharaman 
Acked-by: Hannes Reinecke 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronous

2009-12-04T18:00:46+00:00

Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.

Signed-off-by: Chandra Seetharaman 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: add the interface scsi_dh_set_params()

2009-08-22T22:52:14+00:00

When we moved the device handler functionality from dm layer to SCSI layer
we dropped the parameter functionality.

This path adds an interface to scsi dh layer to set device handler
parameters.

Basically, multipath layer need to create a string with all the parameters
and call scsi_dh_set_params() after it called scsi_dh_attach() on a
device.

If a device handler provides such an interface it will handle the parameters
as it expects them.

Reported-by: Eddie Williams 
Signed-off-by: Chandra Seetharaman 
Tested-by: Eddie Williams 
Signed-off-by: James Bottomley 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: attach to hardware handler from dm-mpath

2008-07-26T19:14:53+00:00

multipath keeps a separate device table which may be
more current than the built-in one.
So we should make sure to always call ->attach whenever
a multipath map with hardware handler is instantiated.
And we should call ->detach on removal, too.

[sekharan: update as per comments from agk]
Signed-off-by: Hannes Reinecke 
Signed-off-by: Chandra Seetharaman 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: Update EMC handler

2008-07-26T19:14:51+00:00

This patch converts the EMC device handler to use a proper
state machine. We now also parse the extended INQUIRY
information to determine if long trespass commands are
supported. And we're now using the long trespass command
correctly. And finally there's now an check at init time
to refuse to attach to devices not supporting EMC-specific
VPD pages.

Signed-off-by: Hannes Reinecke 
Signed-off-by: Chandra Seetharaman 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: fix kconfig related build errors

2008-07-15T14:16:43+00:00

Do not automatically "select" SCSI_DH for dm-multipath. If SCSI_DH
doesn't exist,just do not allow  hardware handlers to be used.

Handle SCSI_DH being a module also. Make sure it doesn't allow DM_MULTIPATH
to be compiled in when SCSI_DH is a module.

[jejb: added comment for Kconfig syntax]
Signed-off-by: Chandra Seetharaman 
Reported-by: Randy Dunlap 
Reported-by: Andrew Morton 
Signed-off-by: James Bottomley