Commit Graph

85 Commits

Author SHA1 Message Date
Chris Leech 6f8830f5bb scsi: libiscsi: add lock around task lists to fix list corruption regression
There's a rather long standing regression from the commit "libiscsi:
Reduce locking contention in fast path"

Depending on iSCSI target behavior, it's possible to hit the case in
iscsi_complete_task where the task is still on a pending list
(!list_empty(&task->running)).  When that happens the task is removed
from the list while holding the session back_lock, but other task list
modification occur under the frwd_lock.  That leads to linked list
corruption and eventually a panicked system.

Rather than back out the session lock split entirely, in order to try
and keep some of the performance gains this patch adds another lock to
maintain the task lists integrity.

Major enterprise supported kernels have been backing out the lock split
for while now, thanks to the efforts at IBM where a lab setup has the
most reliable reproducer I've seen on this issue.  This patch has been
tested there successfully.

Signed-off-by: Chris Leech <cleech@redhat.com>
Fixes: 659743b02c ("[SCSI] libiscsi: Reduce locking contention in fast path")
Reported-by: Prashantha Subbarao <psubbara@us.ibm.com>
Reviewed-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-02-28 22:05:22 -05:00
Christoph Hellwig b6a05c823f scsi: remove eh_timed_out methods in the transport template
Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates.  This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-02-06 19:10:03 -05:00
Christoph Hellwig db5ed4dfd5 scsi: drop reason argument from ->change_queue_depth
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 <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24 14:45:27 +01:00
Linus Torvalds 877f075aac Main batch of InfiniBand/RDMA changes for 3.15:
- The biggest change is core API extensions and mlx5 low-level driver
    support for handling DIF/DIX-style protection information, and the
    addition of PI support to the iSER initiator.  Target support will be
    arriving shortly through the SCSI target tree.
 
  - A nice simplification to the "umem" memory pinning library now that
    we have chained sg lists.  Kudos to Yishai Hadas for realizing our
    code didn't have to be so crazy.
 
  - Another nice simplification to the sg wrappers used by qib, ipath and
    ehca to handle their mapping of memory to adapter.
 
  - The usual batch of fixes to bugs found by static checkers etc. from
    intrepid people like Dan Carpenter and Yann Droneaud.
 
  - A large batch of cxgb4, ocrdma, qib driver updates.
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Merge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband

Pull infiniband updates from Roland Dreier:
 "Main batch of InfiniBand/RDMA changes for 3.15:

   - The biggest change is core API extensions and mlx5 low-level driver
     support for handling DIF/DIX-style protection information, and the
     addition of PI support to the iSER initiator.  Target support will
     be arriving shortly through the SCSI target tree.

   - A nice simplification to the "umem" memory pinning library now that
     we have chained sg lists.  Kudos to Yishai Hadas for realizing our
     code didn't have to be so crazy.

   - Another nice simplification to the sg wrappers used by qib, ipath
     and ehca to handle their mapping of memory to adapter.

   - The usual batch of fixes to bugs found by static checkers etc.
     from intrepid people like Dan Carpenter and Yann Droneaud.

   - A large batch of cxgb4, ocrdma, qib driver updates"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (102 commits)
  RDMA/ocrdma: Unregister inet notifier when unloading ocrdma
  RDMA/ocrdma: Fix warnings about pointer <-> integer casts
  RDMA/ocrdma: Code clean-up
  RDMA/ocrdma: Display FW version
  RDMA/ocrdma: Query controller information
  RDMA/ocrdma: Support non-embedded mailbox commands
  RDMA/ocrdma: Handle CQ overrun error
  RDMA/ocrdma: Display proper value for max_mw
  RDMA/ocrdma: Use non-zero tag in SRQ posting
  RDMA/ocrdma: Memory leak fix in ocrdma_dereg_mr()
  RDMA/ocrdma: Increment abi version count
  RDMA/ocrdma: Update version string
  be2net: Add abi version between be2net and ocrdma
  RDMA/ocrdma: ABI versioning between ocrdma and be2net
  RDMA/ocrdma: Allow DPP QP creation
  RDMA/ocrdma: Read ASIC_ID register to select asic_gen
  RDMA/ocrdma: SQ and RQ doorbell offset clean up
  RDMA/ocrdma: EQ full catastrophe avoidance
  RDMA/cxgb4: Disable DSGL use by default
  RDMA/cxgb4: rx_data() needs to hold the ep mutex
  ...
2014-04-03 16:57:19 -07:00
Sagi Grimberg 55e51eda48 SCSI/libiscsi: Add check_protection callback for transports
iSCSI needs to be at least aware that a task involves protection
information.  In case it does, after the transaction completed libiscsi
will ask the transport to check the protection status of the
transaction.

Unlike transport errors, DIF errors should not prevent successful
completion of the transaction from the transport point of view, but
should be escelated to scsi mid-layer when constructing the scsi
result and sense data.

check_protection routine will return the ascq corresponding to the DIF
error that occured (or 0 if no error happened).

return ascq:
- 0x1: GUARD_CHECK_FAILED
- 0x2: APPTAG_CHECK_FAILED
- 0x3: REFTAG_CHECK_FAILED

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Alex Tabachnik <alext@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-17 22:33:58 -07:00
Shlomo Pongratz 659743b02c [SCSI] libiscsi: Reduce locking contention in fast path
Replace the session lock with two locks, a forward lock and
a backwards lock named frwd_lock and back_lock respectively.

The forward lock protects resources that change while sending a
request to the target, such as cmdsn, queued_cmdsn, and allocating
task from the commands' pool with kfifo_out.

The backward lock protects resources that change while processing
a response or in error path, such as cmdsn_exp, cmdsn_max, and
returning tasks to the commands' pool with kfifo_in.

Under a steady state fast-path situation, that is when one
or more processes/threads submit IO to an iscsi device and
a single kernel upcall (e.g softirq) is dealing with processing
of responses without errors, this patch eliminates the contention
between the queuecommand()/request response/scsi_done() flows
associated with iscsi sessions.

Between the forward and the backward locks exists a strict locking
hierarchy. The mutual exclusion zone protected by the forward lock can
enclose the mutual exclusion zone protected by the backward lock but not
vice versa.

For example, in iscsi_conn_teardown or in iscsi_xmit_data when there is
a failure and __iscsi_put_task is called, the backward lock is taken while
the forward lock is still taken. On the other hand, if in the RX path a nop
is to be sent, for example in iscsi_handle_reject or __iscsi_complete_pdu
than the forward lock is released and the backward lock is taken for the
duration of iscsi_send_nopout, later the backward lock is released and the
forward lock is retaken.

libiscsi_tcp uses two kernel fifos the r2t pool and the r2t queue.

The insertion and deletion from these queues didn't corespond to the
assumption taken by the new forward/backwards session locking paradigm.

That is, in iscsi_tcp_clenup_task which belongs to the RX (backwards)
path, r2t is taken out from r2t queue and inserted to the r2t pool.
In iscsi_tcp_get_curr_r2t which belong to the TX (forward) path, r2t
is also inserted to the r2t pool and another r2t is pulled from r2t
queue.

Only in iscsi_tcp_r2t_rsp which is called in the RX path but can requeue
to the TX path, r2t is taken from the r2t pool and inserted to the r2t
queue.

In order to cope with this situation, two spin locks were added,
pool2queue and queue2pool. The former protects extracting from the
r2t pool and inserting to the r2t queue, and the later protects the
extracing from the r2t queue and inserting to the r2t pool.

Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
[minor fix up to apply cleanly and compile fix]
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:18 -07:00
Adheer Chandravanshi ae56ff4084 [SCSI] libiscsi: Add local_ipaddr parameter in iscsi_conn struct
Add local_ipaddr param and support get/set operations on it.

Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:26 -08:00
Adheer Chandravanshi f8525eb4cf [SCSI] libiscsi: Exporting new attrs for iscsi session and connection in sysfs
Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-23 13:10:16 -04:00
Eddie Wai 3b9373e95a [SCSI] libiscsi: Added new boot entries in the session sysfs
This is the kernel part of the modification to extract the net params
from the ibft sysfs to the iface struct used for the connection
request upon sync_session in the open-iscsi util.

Three new session sysfs params are defined:
boot_root - holds the name of the /sys/firmware/ibft or iscsi_rootN
boot_nic  - holds the ethernetN name
boot_target - holds the targetN name

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-06-26 18:04:11 -07:00
Adheer Chandravanshi adaf6990dd [SCSI] libiscsi: export function iscsi_switch_str_param
Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-04-11 15:26:48 -07:00
Mike Christie 1304be5fe0 [SCSI] libiscsi_tcp: fix max_r2t manipulation
Problem description from Xi Wang:
A large max_r2t could lead to integer overflow in subsequent call to
iscsi_tcp_r2tpool_alloc(), allocating a smaller buffer than expected
and leading to out-of-bounds write.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19 08:09:00 -06:00
Vikas Chaudhary 3c5c480118 [SCSI] libiscsi: Added support to show targetalias in sysfs
sysfs patch to view target alias:
  /sys/class/iscsi_session/session*/targetalias

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19 08:08:54 -06:00
Andy Grover 516f43a2a5 [SCSI] iscsi: Use struct scsi_lun in iscsi structs instead of u8[8]
struct scsi_lun is also just a struct with an array of 8 octets (64 bits)
but using it instead in iscsi structs lets us call scsilun_to_int
without a cast, and also lets us copy it using assignment, instead of
memcpy().

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-06-29 16:22:13 -05:00
Mike Christie c71b9b669e [SCSI] cxgbi: convert to use iscsi_conn_get_addr_param
This has cxgbi use the iscsi_conn_get_addr_param helper
and the get ep callback.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-24 12:41:15 -05:00
Mike Christie 00f3708e6e [SCSI] libiscsi: add helper to convert addr to string
This adds a helper to convert a addr struct to
a string. This will be used by the drivers in
the next patches.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-24 12:41:08 -05:00
Mike Christie f41d472179 [SCSI] libiscsi: do not take host lock in queuecommand
iscsi_tcp, ib_iser, cxgb*, be2iscsi and bnx2i do not use
the host lock and do not take the session lock against
a irq, so this patch drops the DEF_SCSI_QCMD use. Instead
we just take the session lock and disable bhs.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-31 09:52:44 -06:00
Eddie Wai 8eea2f55a6 [SCSI] bnx2i: Added fix for NOP-Out response panic from unsolicited NOP-In
The patch fixes the following situations where NOP-Out pkt is called for:
- local unsolicited NOP-Out requests (requesting no NOP-In response)
- local NOP-Out responses to unsolicited NOP-In requests

kernel panic is observed due to double session spin_lock requests; one in the
bnx2i_process_nopin_local_cmpl routine in bnx2i_hwi.c and the other in the
iscsi_put_task routine in libiscsi.c

The proposed fix is to export the currently static __iscsi_put_task() routine
and have bnx2i call it directly instead of the iscsi_put_task() routine which
holds the session spin lock.

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Anil Veerabhadrappa <anilgv@broadcom.com>
Acked-by: Benjamin Li <benli@broadcom.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-21 12:24:10 -06:00
Jeff Garzik f281233d3e SCSI host lock push-down
Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16 13:33:23 -08:00
Jayamohan Kallickal 309ce156aa [SCSI] libiscsi: Make iscsi_eh_target_reset start with session reset
The iscsi_eh_target_reset has been modified to attempt
target reset only. If it fails, then iscsi_eh_session_reset
will be called.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jayamohan Kallickal <jayamohank@serverengines.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-03-03 17:39:04 +05:30
Stefani Seibold 4546548789 kfifo: move struct kfifo in place
This is a new generic kernel FIFO implementation.

The current kernel fifo API is not very widely used, because it has to
many constrains.  Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.

I think this are the reasons why kfifo is not in use:

 - The API is to simple, important functions are missing
 - A fifo can be only allocated dynamically
 - There is a requirement of a spinlock whether you need it or not
 - There is no support for data records inside a fifo

So I decided to extend the kfifo in a more generic way without blowing up
the API to much.  The new API has the following benefits:

 - Generic usage: For kernel internal use and/or device driver.
 - Provide an API for the most use case.
 - Slim API: The whole API provides 25 functions.
 - Linux style habit.
 - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
 - Direct copy_to_user from the fifo and copy_from_user into the fifo.
 - The kfifo itself is an in place member of the using data structure, this save an
   indirection access and does not waste the kernel allocator.
 - Lockless access: if only one reader and one writer is active on the fifo,
   which is the common use case, no additional locking is necessary.
 - Remove spinlock - give the user the freedom of choice what kind of locking to use if
   one is required.
 - Ability to handle records. Three type of records are supported:
   - Variable length records between 0-255 bytes, with a record size
     field of 1 bytes.
   - Variable length records between 0-65535 bytes, with a record size
     field of 2 bytes.
   - Fixed size records, which no record size field.
 - Preserve memory resource.
 - Performance!
 - Easy to use!

This patch:

Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure.  This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them.  This
patch changes the implementation and all existing users.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:55 -08:00
Mike Christie 3fe5ae8b4c [SCSI] libiscsi: add warm target reset tmf support
This implements warm target reset tmf support for
the scsi-ml target reset callback. Previously we would
just drop the session in that callback. This patch will
now try a target reset and if that fails drop the session.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04 12:01:36 -06:00
Mike Christie e881a172da [SCSI] modify change_queue_depth to take in reason why it is being called
This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
	Also converted pmcraid_change_queue_depth and then verified
all modules compile  using "make allmodconfig" for any new build
warnings on X86_64.

	Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04 12:00:41 -06:00
Jayamohan Kallickal b8b9e1b812 [SCSI] libiscsi: iscsi_session_setup to allow for private space
This patch contains changes that allow iscsi_session_setup
to allocate private space for LLD's

Signed-off-by: Jayamohan Kallickal <jayamohank@serverengines.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-10-02 14:01:39 -05:00
Mike Christie 661134ad37 [SCSI] libiscsi, bnx2i: make bound ep check common
bnx2i currently has a check for if a ep is properly bound, so if
iscsi_queuecommand/xmit_task is called while there is no ep
we will not queue IO.

be2iscsi sends IO from queuecommand/xmit_task like how bnx2i does
and needs a similar test. This patch has us just use the suspend_bit
test for this.

When ep_poll has succeeed iscsid will call conn_bind, the LLD will
then call iscsi_conn_bind which will clear the suspend bit.
When ep_disconnect is called (or if there is a conn error) we set
the suspend bit. For the ep_disconnect case I am adding a helper
in this patch that will take the session lock to make sure
iscsi_queuecommand/xmit_task is not running and it will set
the suspend bit.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jayamohan Kallickal <jayamohank@serverengines.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-09-12 09:35:33 -05:00
Mike Christie 4c0ba5d259 [SCSI] libiscsi: add completion function for drivers that do not need pdu processing
beiscsi does not need the iscsi scsi cmd processing. It does not
even get this info on the completion path. This adds a function
to just update the sequencing numbers and complete a task.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jayamohan Kallickal <jayamohank@serverengines.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-09-12 09:35:33 -05:00
Mike Christie d355e57d58 libiscsi: don't run scsi eh if iscsi task is making progress
If we are sending or receiving data for the task successfully do
not run the scsi eh, because we know the task is making progress.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-21 10:52:39 -05:00
Mike Christie b3cd5050bf [SCSI] libiscsi: add task aborted state
If a task did not complete normally due to a TMF, libiscsi will
now complete the task with the state ISCSI_TASK_ABRT_TMF. Drivers
like bnx2i that need to free resources if a command did not complete normally
can then check the task state. If a driver does not need to send
a special command if we have dropped the session then they can check
for ISCSI_TASK_ABRT_SESS_RECOV.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-05-23 15:44:13 -05:00
Mike Christie 3bbaaad95f [SCSI] libiscsi: handle cleanup task races
bnx2i needs to send a hardware specific cleanup command if
a command has not completed normally (iscsi/scsi response from
target), and the session is still ok (this is the case when we
send a TMF to stop the command).

At this time it will need to drop the session lock. The problem
with the current code is that fail_all_commands assumes we
will hold the lock the entire time, so it uses list_for_each_entry_safe.
If while bnx2i drops the session lock multiple cmds complete then
list_for_each_entry_safe will not handle this correctly.

This patch removes the running lists and just has us loop over
the cmds array (in later patches we will then replace that
array with a block tag map at the session level). It also fixes
up the completion path so that if the TMF code and the normal recv
path were completing the same command then they both do not try
to do release the refcount taken when the task is queued.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-05-23 15:44:12 -05:00
Mike Christie 8f9256cea1 [SCSI] libiscsi: export iscsi_itt_to_task for bnx2i
bnx2i needs to be able to look up mgmt task like login and nop, because
it does some processing of them on the completion path. This exports
iscsi_itt_to_task so it can look up the task.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-05-23 15:44:10 -05:00
Mike Christie 6b5d6c443a [SCSI] cxgb3i, iser, iscsi_tcp: set target can queue
Set target can queue limit to the number of preallocated
session tasks we have.

This along with the cxgb3i can_queue patch will fix a throughput
problem where it could only queue one LU worth of data at a time.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-04-27 10:09:54 -05:00
Mike Christie 40a06e755d [SCSI] libiscsi: pass session failure a session struct
The api for conn and session failures is akward because
one takes a conn from the lib and one takes a session
from the class. This syncs up the interfaces to use
structs from the lib.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13 15:29:12 -05:00
Mike Christie 4d1083509a [SCSI] iscsi lib: remove qdepth param from iscsi host allocation
The qdepth setting was useful when we needed libiscsi to verify
the setting. Now we just need to make sure if older tools
passed in zero then we need to set some default.

So this patch just has us use the sht->cmd_per_lun or if
for LLD does a host per session then we can set it on per
host basis.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13 15:28:55 -05:00
Mike Christie 32ae763e3f [SCSI] iscsi lib: have lib create work queue for transmitting IO
We were using the shost work queue which ended up being
a little akward since all iscsi hosts need a thread for
scanning, but only drivers hooked into libiscsi need
a workqueue for transmitting. So this patch moves the
xmit workqueue to the lib.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13 15:28:37 -05:00
Mike Christie e28f3d5b51 [SCSI] libiscsi: don't cap queue depth in iscsi modules
There is no need to cap the queue depth in the modules. We set
this in userspace and can do that there. For performance testing
with ram based targets, this is helpful since we can have very
high queue depths.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13 15:28:06 -05:00
Mike Christie 1b2c7af877 [SCSI] libiscsi: replace scsi_debug logging with session/conn logging
This makes the logging a compile time option and replaces
the scsi_debug macro with session and connection ones
that print out a driver model id prefix.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13 15:27:09 -05:00
Mike Christie 262ef63627 [SCSI] libiscsi: allow drivers to modify the itt sent to the target
bnx2i and cxgb3i need to encode LLD info in the itt so that
the firmware/hardware can process the pdu. This patch allows
the LLDs to encode info in the task->hdr->itt that they
setup in the alloc_pdu callout (any resources that are allocated
can be freed with the pdu in the cleanup_task callout). If
the LLD encodes info in the itt they should implement a
parse_pdu_itt callout. If parse_pdu_itt is not implemented
libiscsi will do the right thing for the LLD.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29 11:24:22 -06:00
Mike Christie 577577da6d [SCSI] libiscsi: prepare libiscsi for new offload engines by modifying unsol data code
cxgb3i offloads data transfers. It does not offload the entire scsi/iscsi
procssing like qla4xxx and it does not offload the iscsi sequence
processing like how bnx2i does. cxgb3i relies on iscsi_tcp for the
seqeunce handling so this changes how we transfer unsolicitied data by
adding a common r2t struct and helpers.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29 11:24:20 -06:00
Mike Christie 8e12452549 [SCSI] libiscsi: rename host reset to target reset
I had this in my patchset to add target reset support, but
it got dropped due to patching conflicts. This initial patch
just renames the function and users. We are actually just
dropping the session, and so this does not have anything to do
with the host exactly. It does for software iscsi because
we allocate a host per session, but for cxgb3i this makes no
sense.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13 09:28:59 -04:00
Mike Christie e5bd7b54e9 [SCSI] libiscsi: Support drivers initiating session removal
If the driver knows when hardware is removed like with cxgb3i,
bnx2i, qla4xxx and iser then we will want to remove the sessions/devices
that are bound to that device before removing the host.

cxgb3i and in the future bnx2i will remove the host and that will
remove all the sessions on the hba. iser can call iscsi_kill_session
when it gets an event that indicates that a hca is removed.
And when qla4xxx is hooked in to the lib (it is only hooked into
the class right now) it can call iscsi remove host like the
partial offload card drivers.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13 09:28:59 -04:00
Mike Christie 913e5bf435 [SCSI] libiscsi, iser, tcp: remove recv_lock
The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.

We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.

This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:22 -05:00
Mike Christie 3cf7b233ff [SCSI] libiscsi: fix cmds_max setting
Drivers expect that the cmds_max value they pass to the iscsi layer
is the max scsi commands  + mgmt tasks. This patch implements that
and fixes some checks for nr cmd limits.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:21 -05:00
Mike Christie 88dfd340b9 [SCSI] iscsi class: Add session initiatorname and ifacename sysfs attrs.
This adds two new attrs used for creating initiator ports and
binding sessions to hardware.

The session level initiatorname:

Since bnx2i does a scsi_host per host device, we need to add the
iface initiator port settings on the session, so we can create
multiple initiator ports (each with different inames) per device/scsi_host.

The current iname reflects that qla4xxx can have one iname per hba, and we are
allocating a host per session for software. The iname on the host will
remain so we can export and set the hba level qla4xxx setting.

The ifacename attr:

To bind a session to a some peice of hardware in userspace we maintain
some mappings, but during boot or iscsid restart (iscsid contains the user
space part of the driver) we need to be able to figure out which of those
host mappings abstractions maps to certain sessions. This patch adds
a ifacename attr, which userspace can set to id the host side of the
endpoint across pivot_roots and iscsid restarts.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:21 -05:00
Mike Christie 7970634b81 [SCSI] iscsi class: user device_for_each_child instead of duplicating session list
Currently we duplicate the list of sessions, because we were using the
test for if a session was on the host list to indicate if the session
was bound or unbound. We can instead use the target_id and fix up
the class so that drivers like bnx2i do not have to manage the target id
space.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:20 -05:00
Mike Christie 9c19a7d038 [SCSI] libiscsi: rename iscsi_cmd_task to iscsi_task
This is the second part of the iscsi task merging, and
all it does it rename iscsi_cmd_task to iscsi_task and
mtask/ctask to just task.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:19 -05:00
Mike Christie 3e5c28ad03 [SCSI] libiscsi: merge iscsi_mgmt_task and iscsi_cmd_task
There is no need to have the mgmt and cmd tasks separate
structs. It used to save a lot of memory when we overprealocated
memory for tasks, but the next patches will set up the
driver so in the future they can use a mempool or some other
common scsi command allocator and common tagging.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:19 -05:00
Mike Christie 0af967f5d4 [SCSI] libiscsi, iscsi_tcp, iser: add session cmds array accessor
Currently to get a ctask from the session cmd array, you have to
know to use the itt modifier. To make this easier on LLDs and
so in the future we can easilly kill the session array and use
the host shared map instead, this patch adds a nice wrapper
to strip the itt into a session->cmds index and return a ctask.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:18 -05:00
Mike Christie 5af3e91d23 [SCSI] iscsi: modify iscsi printk so it can take driver data pointers
Some drivers want to be able to just pass in the driver data pointers
to the iscsi objects. To enable this we need the iscsi printk macro
to cast the object.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:17 -05:00
Mike Christie 5d91e209fb [SCSI] iscsi: remove session/conn_data_size from iscsi_transport
This removes the session and conn data_size fields from the iscsi_transport.
Just pass in the value like with host allocation. This patch also makes
it so the LLD iscsi_conn data is allocated with the iscsi_cls_conn.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:16 -05:00
Mike Christie a4804cd6eb [SCSI] iscsi: add iscsi host helpers
This finishes the host/session unbinding, by adding some helpers
to add and remove hosts and the session they manage.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:16 -05:00
Mike Christie 756135215e [SCSI] iscsi: remove session and host binding in libiscsi
bnx2i allocates a host per netdevice but will use libiscsi,
so this unbinds the session from the host in that code.

This will also be useful for the iser parent device dma settings
fixes.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:16 -05:00