The following command has been used to verify that the kernel-doc
tool no longer complains about undocumented fields:
scripts/kernel-doc -html drivers/scsi/scsi_transport_srp.c \
include/scsi/scsi_transport_srp.h >srp-transport-doc.html
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The rport timers must be stopped before the SRP initiator destroys the
resources associated with the SCSI host. This is necessary because
otherwise the callback functions invoked from the SRP transport layer
could trigger a use-after-free. Stopping the rport timers before
invoking scsi_remove_host() can trigger long delays in the SCSI error
handler if a transport layer failure occurs while scsi_remove_host()
is in progress. Hence move the code for stopping the rport timers from
srp_rport_release() into a new function and invoke that function after
scsi_remove_host() has finished. This patch fixes the following
sporadic kernel crash:
kernel BUG at include/asm-generic/dma-mapping-common.h:64!
invalid opcode: 0000 [#1] SMP
RIP: 0010:[<ffffffffa03b20b1>] [<ffffffffa03b20b1>] srp_unmap_data+0x121/0x130 [ib_srp]
Call Trace:
[<ffffffffa03b20fc>] srp_free_req+0x3c/0x80 [ib_srp]
[<ffffffffa03b2188>] srp_finish_req+0x48/0x70 [ib_srp]
[<ffffffffa03b21fb>] srp_terminate_io+0x4b/0x60 [ib_srp]
[<ffffffffa03a6fb5>] __rport_fail_io_fast+0x75/0x80 [scsi_transport_srp]
[<ffffffffa03a7438>] rport_fast_io_fail_timedout+0x88/0xc0 [scsi_transport_srp]
[<ffffffff8108b370>] worker_thread+0x170/0x2a0
[<ffffffff81090876>] kthread+0x96/0xa0
[<ffffffff8100c0ca>] child_rip+0xa/0x20
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The current behavior of the SRP transport layer when a transport layer
error is encountered is to block SCSI command processing only if
fast_io_fail_tmo != off. The current behavior of the FC transport
layer when a transport layer error is encountered is to block SCSI
command processing no matter which value fast_io_fail_tmo has been set
to. Make the behavior of the SRP transport layer consistent with that
of the FC transport layer to avoid confusion.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Add support for periodically reconnecting to an SRP target until
the dev_loss timer expires. After the tenth reconnection attempt,
gradually slow down subsequent reconnect attempts.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Add the necessary functions in the SRP transport module to allow an
SRP initiator driver to implement transport layer error handling
similar to the functionality already provided by the FC transport
layer. This includes:
- Support for implementing fast_io_fail_tmo, the time that should
elapse after having detected a transport layer problem and
before failing I/O.
- Support for implementing dev_loss_tmo, the time that should
elapse after having detected a transport layer problem and
before removing a remote port.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Keep the rport data structure around after srp_remove_host() has
finished until cleanup of the IB transport layer has finished
completely. This is necessary because later patches use the rport
pointer inside the queuecommand callback. Without this patch
accessing the rport from inside a queuecommand callback is racy
because srp_remove_host() must be invoked before scsi_remove_host()
and because the queuecommand callback could get invoked after
srp_remove_host() has finished. In other words, without this patch
the queuecommand callback can get invoked after the rport data
structure has been freed.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Make it possible to disconnect the IB RC connection used by the SRP
protocol to communicate with a target.
Have the SRP transport layer create a sysfs "delete" attribute for
initiator drivers that support this functionality.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Eliminate the private_rport_attrs[] array and the SETUP_*() macros
used to set up that array since the information in that array
duplicates the information in the static device attributes. Also,
verify whether SRP_RPORT_ATTRS is large enough since it is easy to
forget to update that macro when adding new attributes.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Register transport attributes after the attribute array has been set
up instead of before. The current code can trigger a race condition
because the code reading the attribute array can run on another thread
than the code that initialized that array. Make sure that any code
reading the attribute array will see all values written into that
array.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
[jejb: limit ioctl to returning 20 characters to avoid overrun
on long device names and add a few more conversions]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
It's big, but there doesn't seem to be a way to split it up smaller...
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Change title to remove "Mid-Layer" since the doc is about all of the
SCSI layers.
- Use "SCSI" instead of "scsi" in docbook text.
- Use "*/" to end kernel-doc notation blocks.
- A few other minor typo fixes.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update
lots of kerneldoc comments in drivers/scsi/*.
Updated with comments from Stefan Richter, Stephen M. Cameron,
James Bottomley and Randy Dunlap.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The SCSI SRP transport class currently iterates over all children
devices of the host that is being removed in srp_remove_host(). However,
not all of those children were created by the SRP transport, and
removing them will cause corruption and an oops when their creator tries
to remove them.
Signed-off-by: David Dillow <dillowda@ornl.gov>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
srp transport works for target drivers without supported_mode
attribute but it would be better to use it explicitly.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
it's better to remove tgt dependencies in srp transport class since
most people want only initiator support.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This moves tsk_mgmt_response callback in struct scsi_host_template to
struct scsi_transport_template since struct scsi_transport_template is
more suitable for the task management stuff.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This adds minimum target driver support:
- srp_rport_{add,del} calls scsi_tgt_it_nexus_{create,destroy} for
target drivers.
- add a callback to notify target drivers of the nexus operation
results to srp_function_template.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This adds a 'roles' attribute to rport like transport_fc. The role can
be initiator or target. That is, the initiator driver creates target
remote ports and the target driver creates initiator remote ports.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This adds srp transport class that works with ib_srp and ibmvscsi.
It creates only /sys/class/{srp_host,srp_remote_ports} and
srp_remote_ports has only "port_id" attribute.
viola:/sys/class/srp_remote_ports/port-0:1# ls
device port_id subsystem uevent
viola:/sys/class/srp_remote_ports/port-0:1# cat port_id
4c:49:4e:55:58:20:56:49:4f:00:00:00:00:00:00:00
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
