linux-toradex.git/drivers/scsi/libfc, branch v4.2.5

libfc: Fix fc_fcp_cleanup_each_cmd()

2015-08-12T18:24:21+00:00

Since fc_fcp_cleanup_cmd() can sleep this function must not
be called while holding a spinlock. This patch avoids that
fc_fcp_cleanup_each_cmd() triggers the following bug:

BUG: scheduling while atomic: sg_reset/1512/0x00000202
1 lock held by sg_reset/1512:
 #0:  (&(&fsp->scsi_pkt_lock)->rlock){+.-...}, at: [] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Preemption disabled at:[] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Call Trace:
 [] dump_stack+0x4f/0x7b
 [] __schedule_bug+0x6c/0xd0
 [] __schedule+0x71a/0xa10
 [] schedule+0x32/0x80
 [] fc_seq_set_resp+0xac/0x100 [libfc]
 [] fc_exch_done+0x41/0x60 [libfc]
 [] fc_fcp_cleanup_each_cmd.isra.21+0xcf/0x150 [libfc]
 [] fc_eh_device_reset+0x1c3/0x270 [libfc]
 [] scsi_try_bus_device_reset+0x29/0x60
 [] scsi_ioctl_reset+0x258/0x2d0
 [] scsi_ioctl+0x150/0x440
 [] sd_ioctl+0xad/0x120
 [] blkdev_ioctl+0x1b6/0x810
 [] block_ioctl+0x38/0x40
 [] do_vfs_ioctl+0x2f8/0x530
 [] SyS_ioctl+0x81/0xa0
 [] system_call_fastpath+0x16/0x7a

Signed-off-by: Bart Van Assche 
Cc: stable 
Signed-off-by: Vasu Dev 
Signed-off-by: James Bottomley

libfc: Fix fc_exch_recv_req() error path

2015-08-12T18:23:30+00:00

Due to patch "libfc: Do not invoke the response handler after
fc_exch_done()" (commit ID 7030fd62) the lport_recv() call
in fc_exch_recv_req() is passed a dangling pointer. Avoid this
by moving the fc_frame_free() call from fc_invoke_resp() to its
callers. This patch fixes the following crash:

general protection fault: 0000 [#3] PREEMPT SMP
RIP: fc_lport_recv_req+0x72/0x280 [libfc]
Call Trace:
 fc_exch_recv+0x642/0xde0 [libfc]
 fcoe_percpu_receive_thread+0x46a/0x5ed [fcoe]
 kthread+0x10a/0x120
 ret_from_fork+0x42/0x70

Signed-off-by: Bart Van Assche 
Cc: stable 
Signed-off-by: Vasu Dev 
Signed-off-by: James Bottomley

scsi: drop reason argument from ->change_queue_depth

2014-11-24T13:45:27+00:00

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Mike Christie 
Reviewed-by: Hannes Reinecke

scsi: avoid ->change_queue_depth indirection for queue full tracking

2014-11-24T13:45:12+00:00

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Mike Christie 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Venkatesh Srinivas

scsi: don't set tagging state from scsi_adjust_queue_depth

2014-11-12T10:19:43+00:00

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Mike Christie 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Martin K. Petersen

scsi: always assign block layer tags if enabled

2014-11-12T10:19:43+00:00

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Mike Christie 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke

scsi: provide a generic change_queue_type method

2014-11-12T10:19:39+00:00

Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Bart Van Assche 
Reviewed-by: Mike Christie 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke

libfc: Replace rcu_assign_pointer() with RCU_INIT_POINTER()

2014-09-30T07:28:36+00:00

The uses of "rcu_assign_pointer()" are NULLing out the pointers.
According to RCU_INIT_POINTER()'s block comment:
"1.   This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
  (..., NULL)

Signed-off-by: Andreea-Cristina Bernat 
Acked-by: Vasu Dev 
Signed-off-by: Christoph Hellwig

fcp: Do not interpret check condition as underrun

2013-09-04T20:52:35+00:00

This patch avoids that the FCoE initiator sends a REC message after
having received a SCSI response with non-zero status and non-zero
DATA IN buffer length.

Signed-off-by: Bart Van Assche 
Cc: Neil Horman 
Signed-off-by: Robert Love

libfc: Do not invoke the response handler after fc_exch_done()

2013-09-04T20:45:22+00:00

While the FCoE initiator driver invokes fc_exch_done() from inside
the libfc response handler, FCoE target drivers typically invoke
fc_exch_done() from outside the libfc response handler. The object
fc_exch.arg points at may disappear as soon as fc_exch_done() has
finished. So it's important not to invoke the response handler
function after fc_exch_done() has finished. Modify libfc such that
this guarantee is provided if fc_exch_done() is invoked from
outside a response handler. This patch fixes a sporadic crash in
FCoE target implementations after a command has been aborted.

Signed-off-by: Bart Van Assche 
Cc: Neil Horman 
Signed-off-by: Robert Love