Change the test for if a cmd is a tmr request to checking if
SCF_SCSI_TMR_CDB (a new flag) is set in cmd->se_cmd_flags.

Also remove se_tmr_req_cache usage in favor of kzalloc usage,
and make core_tmr_alloc_req() return int + setup se_cmd->se_tmr_req
directly and fix up various fabric module usages

Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch addresses a bug where iscsit_free_cmd() was incorrectly calling
iscsit_release_cmd() for ISCSI_OP_REJECT because iscsi_add_reject*() will
overwrite the original iscsi_cmd->iscsi_opcode assignment.  This bug was
introduced with the following commit:

commit 0be67f2ed8f577d2c72d917928394c5885fa9134
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date:   Sun Oct 9 01:48:14 2011 -0700

    iscsi-target: Remove SCF_SE_LUN_CMD flag abuses

and was manifesting itself as list corruption with the following:

[  131.191092] ------------[ cut here ]------------
[  131.191092] WARNING: at lib/list_debug.c:53 __list_del_entry+0x8d/0x98()
[  131.191092] Hardware name: VMware Virtual Platform
[  131.191092] list_del corruption. prev->next should be ffff880022d3c100, but was 6b6b6b6b6b6b6b6b
[  131.191092] Modules linked in: tcm_vhost ib_srpt ib_cm ib_sa ib_mad ib_core tcm_qla2xxx qla2xxx tcm_loop tcm_fc libfc scsi_transport_fc crc32c iscsi_target_mod target_core_stgt scsi_tgt target_core_pscsi target_core_file target_core_iblock target_core_mod configfs ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi sr_mod cdrom sd_mod e1000 ata_piix libata mptspi mptscsih mptbase [last unloaded: scsi_wait_scan]
[  131.191092] Pid: 2250, comm: iscsi_ttx Tainted: G        W    3.2.0-rc4+ #42
[  131.191092] Call Trace:
[  131.191092]  [<ffffffff8103b553>] warn_slowpath_common+0x80/0x98
[  131.191092]  [<ffffffff8103b5ff>] warn_slowpath_fmt+0x41/0x43
[  131.191092]  [<ffffffff811d0279>] __list_del_entry+0x8d/0x98
[  131.191092]  [<ffffffffa01395c9>] transport_lun_remove_cmd+0x9b/0xb7 [target_core_mod]
[  131.191092]  [<ffffffffa013a55c>] transport_generic_free_cmd+0x5d/0x71 [target_core_mod]
[  131.191092]  [<ffffffffa01a012b>] iscsit_free_cmd+0x1e/0x27 [iscsi_target_mod]
[  131.191092]  [<ffffffffa01a13be>] iscsit_close_connection+0x14d/0x5b2 [iscsi_target_mod]
[  131.191092]  [<ffffffffa0196a0c>] iscsit_take_action_for_connection_exit+0xdb/0xe0 [iscsi_target_mod]
[  131.191092]  [<ffffffffa01a55d4>] iscsi_target_tx_thread+0x15cb/0x1608 [iscsi_target_mod]
[  131.191092]  [<ffffffff8103609a>] ? check_preempt_wakeup+0x121/0x185
[  131.191092]  [<ffffffff81030801>] ? __dequeue_entity+0x2e/0x33
[  131.191092]  [<ffffffffa01a4009>] ? iscsit_send_text_rsp+0x25f/0x25f [iscsi_target_mod]
[  131.191092]  [<ffffffffa01a4009>] ? iscsit_send_text_rsp+0x25f/0x25f [iscsi_target_mod]
[  131.191092]  [<ffffffff8138f706>] ? schedule+0x55/0x57
[  131.191092]  [<ffffffff81056c7d>] kthread+0x7d/0x85
[  131.191092]  [<ffffffff81399534>] kernel_thread_helper+0x4/0x10
[  131.191092]  [<ffffffff81056c00>] ? kthread_worker_fn+0x16d/0x16d
[  131.191092]  [<ffffffff81399530>] ? gs_change+0x13/0x13

Reported-by: <jrepac@yahoo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

A reader should spend an extra moment whenever noticing a cast,
because either something special is going on that deserves extra
attention or, as is all too often the case, the code is wrong.

These casts, afaics, have all been useless.  They cast a foo* to a
foo*, cast a void* to the assigned type, cast a foo* to void*, before
assigning it to a void* variable, etc.

In a few cases I also removed an additional &...[0], which is equally
useless.

Lastly I added three FIXMEs where, to the best of my judgement, the
code appears to have a bug.  It would be good if someone could check
these.
Signed-off-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This reorganized the headers under include/target into:

 - target_core_base.h stays as is with all target-wide data stuctures and defines
 - target_core_backend.h contains the whole interface to I/O backends
 - target_core_fabric.h contains the whole interface to fabric modules

Except for those only the various configfs macro headers stay around.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch removes a number of SCF_SE_LUN_CMD flag abuses within iscsi-target
code to determine when iscsit_release_cmd() or transport_generic_free_cmd()
should be called while releasing an individual iscsi_cmd descriptor.

In the place of SCF_SE_LUN_CMD checks, this patch converts existing code to
use a new iscsit_free_cmd() that inspects iscsi_cmd->iscsi_opcode types to
determine which of the above functions should be invoked.  It also removes the
now unnecessary special case checking in iscsit_release_commands_from_conn().

(hch: Use iscsit_free_cmd instead of open-coded alternative)
Reported-by: NChristoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Testing in_interrupt() to know when sleeping is allowed is not really
reliable (since eg it won't be true if the caller is holding a spinlock).
Instead have the caller tell core_tmr_alloc_req() what GFP_xxx to use;
every caller except tcm_qla2xxx can use GFP_KERNEL.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a bug in the iscsit_fe_sendpage_sg() transmit codepath that
was originally introduced with the v3.1 iscsi-target merge that incorrectly
uses hardcoded cmd->iov_data_count values to determine cmd->iov_data[] offsets
for extra outgoing padding and DataDigest payload vectors.

This code is obviously incorrect for the DataDigest enabled case with sendpage
offload, and this fix ensures correct operation for padding + DataDigest,
padding only, and DataDigest only cases.  The bug was introduced during a
pre-merge change in iscsit_fe_sendpage_sg() to natively use struct scatterlist
instead of the legacy v3.0 struct se_mem logic.

Cc: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch makes iscsi-target explictly disable OFMarker=Yes and IFMarker=yes
parameter key usage during iscsi login by setting IFMarkInt_Reject and
OFMarkInt_Reject values in iscsi_enforce_integrity_rules() to effectively
disable iscsi marker usage.  With this patch, an initiator proposer asking
to enable either marker parameter keys will be issued a 'No' response, and
the target sets OFMarkInt + IFMarkInt parameter key response to 'Irrelevant'.

With markers disabled during iscsi login, this patch removes the problematic
on-stack local-scope array for marker intervals in iscsit_do_rx_data() +
iscsit_do_tx_data(), and other related marker code in iscsi_target_util.c.
This fixes a potentional stack smashing scenario with small range markers
enabled and a large MRDSL as reported by DanC here:

[bug report] target: stack can be smashed
http://www.spinics.net/lists/target-devel/msg00453.htmlReported-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes two bugs in allocation failure handling in
iscsit_allocate_se_cmd_for_tmr():

This first reported by DanC is a free-after call to transport_free_se_cmd(), this
patch drops the transport_free_se_cmd() call all together, as iscsit_release_cmd()
will release existing allocations as expected.

The second is a bug where iscsi_cmd_t was being leaked on a cmd->tmr_req allocation
failure, so make this jump to iscsit_release_cmd() as well.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel.  More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

   * RFC-3720 defined request / response state machines and support for
     all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
     include/scsi/iscsi_proto.h PDU definitions
   * Target v4.1 compatible control plane using the generic layout in
     target_core_fabric_configfs.c and fabric dependent attributes
     within /sys/kernel/config/target/iscsi/ subdirectories.
   * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
   * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
   * iSCSI Error Recovery Hierarchy support
   * Per iSCSI connection RX/TX thread pair scheduling affinity
   * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
   * CHAP Authentication support using libcrypto
   * Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
     transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
      iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAndy Grover <agrover@redhat.com>
Acked-by: NRoland Dreier <roland@kernel.org>
Signed-off-by: NNicholas A. Bellinger <nab@linux-iscsi.org>