linux.git/include/scsi/libiscsi.h, branch v2.6.38

[SCSI] libiscsi: do not take host lock in queuecommand

2010-12-31T15:52:44+00:00

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 
Signed-off-by: James Bottomley

[SCSI] bnx2i: Added fix for NOP-Out response panic from unsolicited NOP-In

2010-12-21T18:24:10+00:00

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 
Reviewed-by: Michael Chan 
Reviewed-by: Anil Veerabhadrappa 
Acked-by: Benjamin Li 
Reviewed-by: Mike Christie 
Signed-off-by: James Bottomley

SCSI host lock push-down

2010-11-16T21:33:23+00:00

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 
Acked-by: James Bottomley 
Signed-off-by: Linus Torvalds

[SCSI] libiscsi: Make iscsi_eh_target_reset start with session reset

2010-03-03T12:09:04+00:00

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 
Signed-off-by: Jayamohan Kallickal 
Signed-off-by: James Bottomley

kfifo: move struct kfifo in place

2009-12-22T22:17:55+00:00

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 
Acked-by: Greg Kroah-Hartman 
Acked-by: Mauro Carvalho Chehab 
Acked-by: Andi Kleen 
Acked-by: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[SCSI] libiscsi: add warm target reset tmf support

2009-12-04T18:01:36+00:00

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 
Signed-off-by: James Bottomley

[SCSI] modify change_queue_depth to take in reason why it is being called

2009-12-04T18:00:41+00:00

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 

[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 
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley

[SCSI] libiscsi: iscsi_session_setup to allow for private space

2009-10-02T19:01:39+00:00

This patch contains changes that allow iscsi_session_setup
to allocate private space for LLD's

Signed-off-by: Jayamohan Kallickal 
Acked-by: Mike Christie 
Signed-off-by: James Bottomley

[SCSI] libiscsi, bnx2i: make bound ep check common

2009-09-12T14:35:33+00:00

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 
Signed-off-by: Jayamohan Kallickal 
Signed-off-by: James Bottomley

[SCSI] libiscsi: add completion function for drivers that do not need pdu processing

2009-09-12T14:35:33+00:00

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 
Signed-off-by: Jayamohan Kallickal 
Signed-off-by: James Bottomley