commit fd1b6c4a693c9cac59375ffb36ffe5d7c079037c upstream.

SCSI scanning of a channel:id:lun triplet in Linux works as follows
(function scsi_scan_target() in drivers/scsi/scsi_scan.c):

- If lun == SCAN_WILD_CARD, send a REPORT LUNS command to the target
  and process the result.

- If lun != SCAN_WILD_CARD, send an INQUIRY command to the LUN
  corresponding to the specified channel:id:lun triplet to verify
  whether the LUN exists.

So a SCSI driver must either take the channel and target id values in
account in its quecommand() function or it should declare that it only
supports one channel and one target id.

Currently the ib_srp driver does neither.  As a result scanning the
SCSI bus via e.g. rescan-scsi-bus.sh causes many duplicate SCSI
devices to be created. For each 0:0:L device, several duplicates are
created with the same LUN number and with (C:I) != (0:0). Fix this by
declaring that the ib_srp driver only supports one channel and one
target id.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  RDMA/cma: Save PID of ID's owner
  RDMA/cma: Add support for netlink statistics export
  RDMA/cma: Pass QP type into rdma_create_id()
  RDMA: Update exported headers list
  RDMA/cma: Export enum cma_state in <rdma/rdma_cm.h>
  RDMA/nes: Add a check for strict_strtoul()
  RDMA/cxgb3: Don't post zero-byte read if endpoint is going away
  RDMA/cxgb4: Use completion objects for event blocking
  IB/srp: Fix integer -> pointer cast warnings
  IB: Add devnode methods to cm_class and umad_class
  IB/mad: Return EPROTONOSUPPORT when an RDMA device lacks the QP required
  IB/uverbs: Add devnode method to set path/mode
  RDMA/ucma: Add .nodename/.mode to tell userspace where to create device node
  RDMA: Add netlink infrastructure
  RDMA: Add error handling to ib_core_init()

The RDMA CM currently infers the QP type from the port space selected
by the user.  In the future (eg with RDMA_PS_IB or XRC), there may not
be a 1-1 correspondence between port space and QP type.  For netlink
export of RDMA CM state, we want to export the QP type to userspace,
so it is cleaner to explicitly associate a QP type to an ID.

Modify rdma_create_id() to allow the user to specify the QP type, and
use it to make our selections of datagram versus connected mode.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

Fix

    drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_handle_recv':
    drivers/infiniband/ulp/srp/ib_srp.c:1150: warning: cast to pointer from integer of different size
    drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_send_completion':
    drivers/infiniband/ulp/srp/ib_srp.c:1234: warning: cast to pointer from integer of different size

by adding an intermediate cast to uintptr_t.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Acked-by: David Dillow <dillowda@ornl.gov>

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB: Increase DMA max_segment_size on Mellanox hardware
  IB/mad: Improve an error message so error code is included
  RDMA/nes: Don't print success message at level KERN_ERR
  RDMA/addr: Fix return of uninitialized ret value
  IB/srp: try to use larger FMR sizes to cover our mappings
  IB/srp: add support for indirect tables that don't fit in SRP_CMD
  IB/srp: rework mapping engine to use multiple FMR entries
  IB/srp: allow sg_tablesize to be set for each target
  IB/srp: move IB CM setup completion into its own function
  IB/srp: always avoid non-zero offsets into an FMR

Now that we can get larger SG lists, we can take advantage of HCAs that
allow us to use larger FMR sizes. In many cases, we can use up to 512
entries, so start there and work our way down.

Signed-off-by: David Dillow <dillowda@ornl.gov>

This allows us to guarantee the ability to submit up to 8 MB requests
based on the current value of SCSI_MAX_SG_CHAIN_SEGMENTS. While FMR will
usually condense the requests into 8 SG entries, it is imperative that
the target support external tables in case the FMR mapping fails or is
not supported.

We add a safety valve to allow targets without the needed support to
reap the benefits of the large tables, but fail in a manner that lets
the user know that the data didn't make it to the device. The user must
add "allow_ext_sg=1" to the target parameters to indicate that the
target has the needed support.

If indirect_sg_entries is not specified in the modules options, then
the sg_tablesize for the target will default to cmd_sg_entries unless
overridden by the target options.

Signed-off-by: David Dillow <dillowda@ornl.gov>