Convert xmit to iscsi chunks.

from michaelc@cs.wisc.edu:

Bug fixes, more digest integration, sg chaining conversion and other
sg wrapper changes, coding style sync up, and removal of io fields,
like pdu_sent, that are not needed.
Signed-off-by: NOlaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The driver does not need the host lock in queuecommand so drop it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

If the current ctask is failed early, we legt the conn->ctask pointer
pointing to a invalid task. When the xmit thread would send data for
it, we would then oops.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

If the target requests a logout, then we do not want
to fail commands to scsi-ml right away. This patch just
fails in pending commands for a requeue immediately, and then lets
iscsid handle running commands like normal recovery.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

During root boot and shutdown the target could send us nops.
At this time iscsid cannot be running, so the target will drop
the session and the boot or shutdown will hang.

To handle this and allow us to better control when to check the network
this patch moves the nop handling to the kernel.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We were using the device delete sysfs file to remove each device
then logout. Now in 2.6.21 this will not work because
the sysfs delete file returns immediately and does not wait for
the device removal to complete. This causes a hang if a cache sync
is needed during shutdown. Before .21, that approach had other
problems, so this patch fixes the shutdown code so that we remove the target
and unbind the session before logging out and shut down the session
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

I thought we may not need the eh mutex during host reset, but that is wrong
with the new shutdown code. When start_session_recovery sets the state to
terminate then drops the session lock. The scsi eh thread could then grab the
session lock see that we are terminating and then return failed to scsi-ml.
scsi-ml's eh then owns the command and will do whatever it wants
with it. But then the iscsi eh thread could grab the session lock
and want to complete the scsi commands that we in the LLD, but
it no longer owns them and kaboom.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

There is not need to block the session during logout. Since
we are going to fail the commands that were blocked just fail them
immediately instead.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

iscsi_pool_init simplified

iscsi_pool_init currently has a lot of duplicate kfree() calls it does
when some allocation fails. This patch simplifies the code a little by
using iscsi_pool_free to tear down the pool in case of an error.

iscsi_pool_init also returns a copy of the item array to the caller.
Not all callers use this array, so we make it optional.

Instead of allocating a second array and return that, allocate just one
array, of twice the size.

Update users of iscsi_pool_{init,free}

This patch drops the (now useless) second argument to
iscsi_pool_free, and updates all callers.

It also removes the ctask->r2ts array, which was never
used anyway. Since the items argument to iscsi_pool_init
is now optional, we can pass NULL instead.
Signed-off-by: NOlaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

  - The default initialization of hdr_max is the minimum -
    sizeof(struct iscsi_cmd) - Once this patch goes into iser the default
    initialization at libiscsi can be removed.
  - This is not yet full support for AHSs at iser end. But it should be easy.
    Just allocate more space at iser_desc right after iscsi_hdr. Than
    at transmission time use ctask->hdr_len to retrieve the total
    size of all iscsi pdu headers. See previous patch at iscsi_tcp.[ch]
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

  at libiscsi generic code
  - currently code assumes a storage space of pdu header is allocated
    at llds ctask and is pointed to by iscsi_cmd_task->hdr. Here I add
    a hdr_max field pertaining to that storage, and an hdr_len that
    accumulates the current use of the pdu-header.

  - Add an iscsi_next_hdr() inline which returns the next free space
    to write new Header at. Also iscsi_next_hdr() is used to retrieve
    the address at which to write the header-digest.

  - Add iscsi_add_hdr(length). What the user do is calls iscsi_next_hdr()
    for address of the new header, than calls iscsi_add_hdr(length) with
    the size of the new header. iscsi_add_hdr() will check if space is
    available and update to the new size. length must be padded according
    to standard.

  - Add 2 padding inline helpers thanks to Olaf. Current patch does not
    use them but Following patches will.
    Also moved definition of ISCSI_PAD_LEN to iscsi_proto.h which had
    PAD_WORD_LEN that was never used anywhere.

  - Let iscsi_prep_scsi_cmd_pdu() signal an Error return since now  it is
    possible that it will fail.

  - I was tired of yet again writing a "this is a digest" comment next to
    sizeof(__u32) so I defined a new ISCSI_DIGEST_SIZE. Now I don't need
    any comments. Changed all places that used sizeof(__u32) or "4" in
    connection to a digest.

  iscsi_tcp specific code
  - At struct iscsi_tcp_cmd_task allocate maximum space allowed in
    standard for all headers following the iscsi_cmd header. and mark
    it so in iscsi_tcp_session_create()
  - At iscsi_send_cmd_hdr() retrieve the correct headers size and
    write header digest at iscsi_next_hdr().
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NOlaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

  - Check to see that OVERFLOW is not negative indicating
    a bug.
  - Unify handling of UNDERFLOW and OVERFLOW to the same
    code.
  - Also handle BIDI_OVERFLOW.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch adds logical unit reset support. This should work for ib_iser,
but I have not finished testing that driver so it is not hooked in yet.

This patch also temporarily reverts the iscsi_tcp r2t write out patch.
That code is completely rewritten in this patchset.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Currently, the iSCSI driver returns the data transfer residual for
data-in commands (e.g. read) but not data-out commands (e.g. write).
This patch makes it return the data transfer residual for both types of
commands.
Signed-off-by: NTony Battersby <tonyb@cybernetics.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The iscsi eh could be tearing down the session/connection while
the scsi eh is still sending task management functions. If when
we drop the session lock to grab the recv lock, the iscsi eh
tears down the connection we will oops.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We do not want to send data if we are aborting a task. There is
a check in iscsi_xmit_ctask, but right before calling this we overwrite
the state so we always go right past the test. Sending data causes problems
because when we clean up from a successful abort the LLD assumes that
the task is not running.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We should not be checking the cmd windown for just handling r2t responses.
And if the window closes in on us, always have scsi-ml requeue the command
from our queuecommand function.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

When we logout we block the session since we are not taking any more
commands, but when we call remove host we want to make sure any
IO that got queued up and blocked gets failed upwards quickly, so
we unblock the session and fail it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

- remove the unnecessary map_single path.

- convert to use the new accessors for the sg lists and the
parameters.

TODO: use scsi_for_each_sg().
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

iSCSI must support software iscsi (iscsi_tcp, iser), hardware iscsi (qla4xxx),
and partial offload (broadcom). To be able to allow each stack or driver
or port (virtual or physical) to be able to log into the same target portal
we use the initiator tuple [[HWADDRESS | NETDEVNAME], INITIATOR_NAME] and
the target tuple [TARGETNAME, CONN_ADDRESS, CONN_PORT] to id a session.
This patch adds the netdev name, which is used by software iscsi when
it binds a session to a netdevice using the SO_BINDTODEVICE sock opt.
It cannot use HWADDRESS because if someone did vlans then the same netdevice
will have the same mac and the initiator,target id will not be unique.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: David C Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch allows us to set can_queue and cmds_per_lun from userspace
when we create the session/host. From there we can set it on a per
target basis. The patch fully converts iscsi_tcp, but only hooks
up ib_iser for cmd_per_lun since it currently has a lots of preallocations
based on can_queue.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The cmdsn allocation and pdu transmit code can race, and we can end
up sending a pdu with cmdsn 10 before a pdu with 5. The target will
then fail the connection/session. This patch fixes the problem by
delaying the cmdsn allocation until we are about to send the pdu.

This also removes the xmitmutex. We were using the connection xmitmutex
during error handling to handle races with mtask and ctask cleanup and
completion. For ctasks we now have nice refcounting and for the mtask,
if we hit the case where the mtask timesout and it is floating
around somewhere in the driver, we end up dropping the session.
And to handle session level cleanup, we use the xmit suspend bit
along with scsi_flush_queue and the session lock to make sure
that the xmit thread is not possibly transmitting a task while
we are trying to kill it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

If iscsi_tcp partially sends a header, it would recalculate the
header size and readd the size of the digest (if header digests
are used).This would cause us to send sizeof(digest) extra bytes
when we sent the rest of the header.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The attached patches add sysfs files for the chap settings
to the iscsi transport class, iscsi_tcp and ib_iser. This is
needed for software iscsi because there are times when iscsid
can die and it will need to reread the values it was using.
And it is needed by qla4xxx for basic management opertaions.
This patch does not hook in qla4xxx yet, because I am not sure
the mbx command to use.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

- Remove shadow of request length from struct iscsi_cmd_task.
- change all users to use scsi_cmnd->request_bufflen directly

(With bidi we will use scsi-ml API to retrieve in/out length)
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch fixes handling of expected datasn/r2tsn as received from
target. It is done according to: T10 rfc3720 section 3.2.2.3. Data Sequencing.

. unify expected datasn/r2tsn into one counter
. calculate than check expected datasn/r2tsn. On error print a message
  and fail the request. (TODO use iscsi retransmits)
. remove the FIXME   ;)
. avoid zero length memset
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

For iscsi root boot, software iscsi needs to know what the BIOS/OF
initiator used for the initiator name so this puts it in sysfs
for userspace to be able to pick up.

For hw iscsi, it is nice to see what the card is using.

This patch adds the new param, and hooks in qla4xxx, iscsi_tcp, and ib_iser.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: David C Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

iscsid and udev need to key off the hw address being
used so add some helpers for iser and iscsi tcp.

Also convert them
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Dave Miller meantioned that the data buffer in a past
sense fixup patch was not gauranteed to be aligned
properly for ia64. This patch has libiscsi use get_unalinged
to make sure. There are a couple more places in the
digest handling we may need to do this, but we are in the middle
of fixing that code for big endien systems so just the sense
access is fixed here.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch renames DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH to avoid
confusion with the drivers default values (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH
is the iscsi RFC specific default).
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Consolidate the mtask clearing code.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

It's possible that we call iscsi_xmitworker after iscsi_conn_release
which causes a oops. This patch flushes the workqueue.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Yanling Qi, noted that when the sense data length of
a check-condition is greater than 0x7f (127), senselen = (data[0] << 8)
| data[1] will become negative. It causes different kinds of panics from
GPF, spin_lock deadlock to spin_lock recursion.

We were also swapping this value on big endien machines.

This patch fixes both issues by using be16_to_cpu().
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fix up for make allyesconfig.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

Some messages from debug_scsi do not have trailing newlines,
making console messages difficult to read.  Fix that.
Signed-off-by: NPete Wyckoff <pw@osc.edu>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

According to the iscsi RFC, we cannot send other requests if
we have sent a logout pdu. This patch enforces this requirement
by blocking the session and suspending the send thread. Userspace
decides if we restart the connection or if we just free everything.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We have been dropping the pdu. We should just send it to userspace
and let it handle it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

from bhalevy@gmail.com:

It looks like change 652 to libiscsi.c added some dead code around line
670
                if (rc) {
                        spin_unlock_bh(&conn->session->lock);
                        goto again;
                }

since 5 lines above we goto again if (rc).

It looks like the previous if (rc) should go away if we want to put the
ctask before
breaking out of the while loop with "goto again" (see following patch).
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

If connection creation fails we end up calling list_del
on a invalid struct. This then causes an oops. We are not
acutally using the lists (old MCS code we thought might
be useful elsewhere) so this patch just removes that
code.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>