With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now.  Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Overriding the whole EH code is a per-transport, not per-host thing.
Move ->eh_strategy_handler to the transport class, same as
->eh_timed_out.

Downside is that scsi_host_alloc can't check for the total lack of EH
anymore, but the transition period from old EH where we needed it is
long gone already.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This moves the eh_timed_out functionality from the scsi_host_template
to the transport_template. Given that this is now a transport function,
the EH_RESET_TIMER case no longer caps the timer reschedulings. The
transport guarantees that this is not an infinite condition.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fix up an off by one error in calculating retries for scsi
commands. This bug was discovered when an SG_IO request
was sent to scsi core with retries = 0, causing the overall
timeout check to go off in scsi_softirq_done.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Export two SCSI EH command handling functions.  To be used by libata EH.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

When the scsi_execute_async interface was added it ended up reducing
the flexibility of userspace to send arbitrary scsi commands through
sg using SG_IO. The SG_IO interface allows userspace to specify the
CDB length. This is now ignored in scsi_execute_async and it is
guessed using the COMMAND_SIZE macro, which is not always correct,
particularly for vendor specific commands. This patch adds a cmd_len
parameter to the scsi_execute_async interface to allow the caller
to specify the length of the CDB.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Add scsi helpers to create really-large-requests and convert
scsi-ml to scsi_execute_async().

Per Jens's previous comments, I placed this function in scsi_lib.c.
I made it follow all the queue's limits - I think I did at least :), so
I removed the warning on the function header.

I think the scsi_execute_* functions should eventually take a request_queue
and be placed some place where the dm-multipath hw_handler can use them
if that failover code is going to stay in the kernel. That conversion
patch will be sent in another mail though.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The eh_action semaphore in scsi_eh_send_command is cleared after a
command timeout.  The command is subsequently aborted and the abort
will try to call scsi_done() on it.  Unfortunately, the scsi_eh_done()
routine unconditinally completes the semaphore (which is now null).
Fix this race by makiong the scsi_eh_done() routine check that the
semaphore is non null before completing it (mirroring the ordinary
command done/timeout logic).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

scsi_send_eh_cmnd currently uses a semaphore and an overload of eh_timer
to either get a completion for a command for a timeout.
Switch to using a completion and wait_for_completion_timeout to simply
the code and not having to deal with the races ourselves.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

now that the abuse in qla2xxx is gone this field can be remove.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

adjust comments, remove a useless cast and remove a write-only variable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Wrap a highly common idiom.  Makes the code easier to read, helps pave
the way for sdev->{id,channel} removal, and adds a token that can easily
by grepped-for in the future.

There are a couple sdev_id() and scmd_printk() updates thrown in as well.

Rejections fixed up and
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

rejections fixed and
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This should eliminate (at least in the mid layer) to make numeric
assumptions about any of the enumeration variables.  As a side effect,
it will also make all the messages consistent and line us up nicely for
the error logging strategy (if it ever shows itself again).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Found in the -rt patch set.  The scsi_error thread likely will be in the
TASK_INTERRUPTIBLE state upon exit.  This patch fixes this bug.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Found in the -rt patch set.  The scsi_error thread likely will be in the
TASK_INTERRUPTIBLE state upon exit.  This patch fixes this bug.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

From: 	Alan Stern <stern@rowland.harvard.edu>

This patch (as561) fixes the error handler's thread-exit code.  The
kthread_stop call won't wake the thread from a down_interruptible, so
the patch gets rid of the semaphore and simply does

        set_current_state(TASK_INTERRUPTIBLE);
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>

Modified to simplify the termination loop and correct the sleep condition.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We fix the oops by enforcing the host state model.  There have also
been two extra states added: SHOST_CANCEL_RECOVERY and
SHOST_DEL_RECOVERY so we can take the model through host removal while
the recovery thread is active.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The problem lies in the way the error handler uses TEST UNIT READY to
tell whether error recovery has succeeded.  The scsi_eh_tur function
gives up after one round of retrying; after that it decides that more
error recovery is needed.

However TUR is liable to report sense data indicating a retry is needed
when in fact error recovery has succeeded.  A typical example might be
SK=2, ASC=4, ASCQ=1 (Logical unit in process of becoming ready).  The mere
fact that we were able to get a sensible reply to the TUR should indicate
that the device is working well enough to stop error recovery.

I ran across a case back in January where this happened.  A CD-ROM drive
timed out the INQUIRY command, and a device reset fixed the blockage.
But then the drive kept responding with 2/4/1 -- because it was spinning
up I suppose -- until the error handler gave up and placed it offline.
If the initial INQUIRY had received the 2/4/1 instead, everything would
have worked okay.  It doesn't seem reasonable for things to fail just
because the error handler had started running.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This one's slightly more difficult.  The transport class uses
REQ_FAILFAST, so another interface (scsi_execute) had to be invented to
take the extra flag.  Also, the sense functions are shifted around to
allow spi_execute to place data directly into a struct scsi_sense_hdr.
With this change, there's probably a lot of unnecessary sense buffer
allocation going on which we can fix later.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Migrate the current SCSI host state model to a model like SCSI
device is using.
Signed-off-by: NMike Anderson <andmike@us.ibm.com>

Rejections fixed up and
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Just opencoded access to eh_eflags, it's much more readable anyway.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We never look at it except for the old megaraid driver that abuses it
for sending internal commands.  That usage can be fixed easily because
those internal commands are single-threaded by a mutex and we can easily
use a completion there.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

never checked anywhere
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Never used for anything but printing it out in debug routines.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Save and restore the scmd->result, so that timed out commands do not
return the result of the TEST UNIT READY or the start/stop commands. Code
is already in place to save and restore the result for the request sense
case.

The previous version of this patch erroneously removed the "if" check,
instead add a comment as to why the "if" is needed.
Signed-off-by: NPatrick Mansfield <patmans@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

'if' tests which check if eh_action isn't NULL in both
functions are always true.  Remove the redundant if's as it
can give wrong impressions.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

scsi_reset_provider() calls scsi_delete_timer() on exit which
isn't necessary.  Remove it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Somebody forgot that | has higher priority than ?:.  As the result,
allocation is done with bogus flags - instead of GFP_ATOMIC + possibly
GFP_DMA we always get GFP_DMA and no GFP_ATOMIC. 
Signed-off-by: NAl Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes scsi_send_eh_cmnd() use sdev and shost instead of
referencing them through scmd-> everytime.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We have a DID_IMM_RETRY to require a retry at once, but we could do with
a DID_REQUEUE to instruct the mid-layer to treat this command in the
same manner as QUEUE_FULL or BUSY (i.e. halt the submission until
another command returns ... or the queue pressure builds if there are no
outstanding commands).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

scsi_cmnd->serial_number_at_timeout doesn't serve any purpose
anymore.  All serial_number == serial_number_at_timeout tests
are always true in abort callbacks.  Kill the field.  Also, as
->pid always equals ->serial_number and ->serial_number
doesn't have any special meaning anymore, update comments
above ->serial_number accordingly.  Once we remove all uses of
this field from all lldd's, this field should go.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

scsi_cmnd->internal_timeout field doesn't have any meaning
anymore.  Kill the field.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>