This patch converts tcm_fc to use transport_init_session_tags()
pre-allocation logic for struct ft_cmd descriptors using per-cpu
session tag pooling in order to effectively avoid memory allocation
+ release for each received I/O.

It adds percpu_ida_alloc() in ft_recv_cmd() to obtain an tag and
locate ft_cmd from se_sess->sess_cmd_map[], and percpu_ida_free()
in ft_free_cmd() to release the tag based upon se_cmd->map_tag id.

It also uses a TCM_FC_DEFAULT_TAGS value of 512, that puts the
per se_sess->sess_cmd_map allocation at ~360K on 64-bit.

v2 changes:

  - Handle possible tag < 0 failure with GFP_ATOMIC

Cc: Mark Rustad <mark.d.rustad@intel.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: NNicholas Bellinger <nab@daterainc.com>

The callback function of call_rcu() just calls a kfree(), so we
can use kfree_rcu() instead of call_rcu() + callback function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clear the target role when no target is provided for
the node performing a PRLI.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Reviewed-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Acked by Robert Love <robert.w.love@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

When generating a PRLI response to an initiator, clear the
FCP_SPPF_RETRY bit in the response.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Reviewed-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Acked by Robert Love <robert.w.love@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The lockdep warning below is in theory correct but it will be in really weird
rare situation that ends up that deadlock since the tcm fc session is hashed
based the rport id. Nonetheless, the complaining below is about rcu callback
that does the transport_deregister_session() is happening in softirq, where
transport_register_session() that happens earlier is not. This triggers the
lockdep warning below. So, just fix this to make lockdep happy by disabling
the soft irq before calling transport_register_session() in ft_prli.

BTW, this was found in FCoE VN2VN over two VMs, couple of create and destroy
would get this triggered.

v1: was enforcing register to be in softirq context which was not righ. See,
http://www.spinics.net/lists/target-devel/msg03614.html

v2: following comments from Roland&Nick (thanks), it seems we don't have to
do transport_deregister_session() in rcu callback, so move it into ft_sess_free()
but still do kfree() of the corresponding ft_sess struct in rcu callback to
make sure the ft_sess is not freed till the rcu callback.

...
[ 1328.370592] scsi2 : FCoE Driver
[ 1328.383429] fcoe: No FDMI support.
[ 1328.384509] host2: libfc: Link up on port (000000)
[ 1328.934229] host2: Assigned Port ID 00a292
[ 1357.232132] host2: rport 00a393: Remove port
[ 1357.232568] host2: rport 00a393: Port sending LOGO from Ready state
[ 1357.233692] host2: rport 00a393: Delete port
[ 1357.234472] host2: rport 00a393: work event 3
[ 1357.234969] host2: rport 00a393: callback ev 3
[ 1357.235979] host2: rport 00a393: Received a LOGO response closed
[ 1357.236706] host2: rport 00a393: work delete
[ 1357.237481]
[ 1357.237631] =================================
[ 1357.238064] [ INFO: inconsistent lock state ]
[ 1357.238450] 3.7.0-rc7-yikvm+ #3 Tainted: G           O
[ 1357.238450] ---------------------------------
[ 1357.238450] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 1357.238450] ksoftirqd/0/3 [HC0[0]:SC1[1]:HE0:SE0] takes:
[ 1357.238450]  (&(&se_tpg->session_lock)->rlock){+.?...}, at: [<ffffffffa01eacd4>] transport_deregister_session+0x41/0x148 [target_core_mod]
[ 1357.238450] {SOFTIRQ-ON-W} state was registered at:
[ 1357.238450]   [<ffffffff810834f5>] mark_held_locks+0x6d/0x95
[ 1357.238450]   [<ffffffff8108364a>] trace_hardirqs_on_caller+0x12d/0x197
[ 1357.238450]   [<ffffffff810836c1>] trace_hardirqs_on+0xd/0xf
[ 1357.238450]   [<ffffffff8149caba>] _raw_spin_unlock_irq+0x2d/0x45
[ 1357.238450]   [<ffffffffa01e8d10>] __transport_register_session+0xb8/0x122 [target_core_mod]
[ 1357.238450]   [<ffffffffa01e8dbe>] transport_register_session+0x44/0x5a [target_core_mod]
[ 1357.238450]   [<ffffffffa018e32c>] ft_prli+0x1e3/0x275 [tcm_fc]
[ 1357.238450]   [<ffffffffa0160e8d>] fc_rport_recv_req+0x95e/0xdc5 [libfc]
[ 1357.238450]   [<ffffffffa015be88>] fc_lport_recv_els_req+0xc4/0xd5 [libfc]
[ 1357.238450]   [<ffffffffa015c778>] fc_lport_recv_req+0x12f/0x18f [libfc]
[ 1357.238450]   [<ffffffffa015a6d7>] fc_exch_recv+0x8ba/0x981 [libfc]
[ 1357.238450]   [<ffffffffa0176d7a>] fcoe_percpu_receive_thread+0x47a/0x4e2 [fcoe]
[ 1357.238450]   [<ffffffff810549f1>] kthread+0xb1/0xb9
[ 1357.238450]   [<ffffffff814a40ec>] ret_from_fork+0x7c/0xb0
[ 1357.238450] irq event stamp: 275411
[ 1357.238450] hardirqs last  enabled at (275410): [<ffffffff810bb6a0>] rcu_process_callbacks+0x229/0x42a
[ 1357.238450] hardirqs last disabled at (275411): [<ffffffff8149c2f7>] _raw_spin_lock_irqsave+0x22/0x8e
[ 1357.238450] softirqs last  enabled at (275394): [<ffffffff8103d669>] __do_softirq+0x246/0x26f
[ 1357.238450] softirqs last disabled at (275399): [<ffffffff8103d6bb>] run_ksoftirqd+0x29/0x62
[ 1357.238450]
[ 1357.238450] other info that might help us debug this:
[ 1357.238450]  Possible unsafe locking scenario:
[ 1357.238450]
[ 1357.238450]        CPU0
[ 1357.238450]        ----
[ 1357.238450]   lock(&(&se_tpg->session_lock)->rlock);
[ 1357.238450]   <Interrupt>
[ 1357.238450]     lock(&(&se_tpg->session_lock)->rlock);
[ 1357.238450]
[ 1357.238450]  *** DEADLOCK ***
[ 1357.238450]
[ 1357.238450] no locks held by ksoftirqd/0/3.
[ 1357.238450]
[ 1357.238450] stack backtrace:
[ 1357.238450] Pid: 3, comm: ksoftirqd/0 Tainted: G           O 3.7.0-rc7-yikvm+ #3
[ 1357.238450] Call Trace:
[ 1357.238450]  [<ffffffff8149399a>] print_usage_bug+0x1f5/0x206
[ 1357.238450]  [<ffffffff8100da59>] ? save_stack_trace+0x2c/0x49
[ 1357.238450]  [<ffffffff81082aae>] ? print_irq_inversion_bug.part.14+0x1ae/0x1ae
[ 1357.238450]  [<ffffffff81083336>] mark_lock+0x106/0x258
[ 1357.238450]  [<ffffffff81084e34>] __lock_acquire+0x2e7/0xe53
[ 1357.238450]  [<ffffffff8102903d>] ? pvclock_clocksource_read+0x48/0xb4
[ 1357.238450]  [<ffffffff810ba6a3>] ? rcu_process_gp_end+0xc0/0xc9
[ 1357.238450]  [<ffffffffa01eacd4>] ? transport_deregister_session+0x41/0x148 [target_core_mod]
[ 1357.238450]  [<ffffffff81085ef1>] lock_acquire+0x119/0x143
[ 1357.238450]  [<ffffffffa01eacd4>] ? transport_deregister_session+0x41/0x148 [target_core_mod]
[ 1357.238450]  [<ffffffff8149c329>] _raw_spin_lock_irqsave+0x54/0x8e
[ 1357.238450]  [<ffffffffa01eacd4>] ? transport_deregister_session+0x41/0x148 [target_core_mod]
[ 1357.238450]  [<ffffffffa01eacd4>] transport_deregister_session+0x41/0x148 [target_core_mod]
[ 1357.238450]  [<ffffffff810bb6a0>] ? rcu_process_callbacks+0x229/0x42a
[ 1357.238450]  [<ffffffffa018ddc5>] ft_sess_rcu_free+0x17/0x24 [tcm_fc]
[ 1357.238450]  [<ffffffffa018ddae>] ? ft_sess_free+0x1b/0x1b [tcm_fc]
[ 1357.238450]  [<ffffffff810bb6d7>] rcu_process_callbacks+0x260/0x42a
[ 1357.238450]  [<ffffffff8103d55d>] __do_softirq+0x13a/0x26f
[ 1357.238450]  [<ffffffff8149b34e>] ? __schedule+0x65f/0x68e
[ 1357.238450]  [<ffffffff8103d6bb>] run_ksoftirqd+0x29/0x62
[ 1357.238450]  [<ffffffff8105c83c>] smpboot_thread_fn+0x1a5/0x1aa
[ 1357.238450]  [<ffffffff8105c697>] ? smpboot_unregister_percpu_thread+0x47/0x47
[ 1357.238450]  [<ffffffff810549f1>] kthread+0xb1/0xb9
[ 1357.238450]  [<ffffffff8149b49d>] ? wait_for_common+0xbb/0x10a
[ 1357.238450]  [<ffffffff81054940>] ? __init_kthread_worker+0x59/0x59
[ 1357.238450]  [<ffffffff814a40ec>] ret_from_fork+0x7c/0xb0
[ 1357.238450]  [<ffffffff81054940>] ? __init_kthread_worker+0x59/0x59
[ 1417.440099]  rport-2:0-0: blocked FC remote port time out: removing rport
Signed-off-by: NYi Zou <yi.zou@intel.com>
Cc: Open-FCoE <devel@open-fcoe.org>
Cc: Nicholas A. Bellinger <nab@risingtidesystems.com>
Cc: stable@vger.kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Remove including <generated/utsrelease.h> that don't need it.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Use rcu_dereference_protected in order to prevent lockdep
complaint. Sequel of the patch 863555be

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: NDenis Efremov <yefremov.denis@gmail.com>
Acked-by: NMark D. Rustad <mark.d.rustad@intel.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Use rcu_dereference_protected to tell rcu that the ft_lport_lock
is held during ft_lport_create. This resolved "suspicious RCU usage"
warnings when debugging options are turned on.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Get rid of a bunch of write-only variables.  In a number of cases I
suspect actual bugs to be present, so I left all of those for a second
look.

(nab: fix lio-core patch fuzz)
Signed-off-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch drops the following unused legacy API callers from target_core_fabric.h:

*) TFO->fall_back_to_erl0()
*) TFO->stop_session()
*) TFO->sess_logged_in()
*) TFO->is_state_remove()

This patch also removes the stub usage in loopback, tcm_fc, iscsi_target,
and ib_srpt fabric modules.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The call_rcu() in ft_tport_delete() invokes ft_tport_rcu_free(),
which just does a kfree().  So convert the call_rcu() to kfree_rcu(),
allowing ft_tport_rcu_free() to be eliminated.
Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.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>

It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/target/.
This patch removes them.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/target/.
This patch removes them.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This patch contains the squashed version of forth round series cleanups
from Andy and Christoph following the post heavy lifting in the preceeding:
'Eliminate usage of struct se_mem' and 'Make all control CDBs scatter-gather'
changes.  This also includes a conversion of target core and the v3.0
mainline fabric modules (loopback and tcm_fc) to use pr_debug and the
CONFIG_DYNAMIC_DEBUG infrastructure!

These have been squashed into this third and final round for v3.1.

target: Remove ifdeffed code in t_g_process_write
target: Remove direct ramdisk code
target: Rename task_sg_num to task_sg_nents
target: Remove custom debug macros for pr_debug. Use pr_err().
target: Remove custom debug macros in mainline fabrics
target: Set WSNZ=1 in block limits VPD. Abort if WRITE_SAME sectors = 0
target: Remove transport do_se_mem_map callback
target: Further simplify transport_free_pages
target: Redo task allocation return value handling
target: Remove extra parentheses
target: change alloc_task call to take *cdb, not *cmd

(nab: Fix bogus struct file assignments in fd_do_readv and fd_do_writev)
Signed-off-by: NAndy Grover <agrover@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

There is a typo here, it should be an unlock instead of a lock.  The
original code will deadlock.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

transport_init_session() and core_tmr_alloc_req() never return NULL,
they only return ERR_PTRs on error.

v2: Fix patch to return PTR_ERR(tl_nexus->se_sess) from Ankit Jain's
feedback.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NAnkit Jain <jankit@suse.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Many stupid corrections of duplicated includes based on the output of
scripts/checkincludes.pl.
Signed-off-by: NVitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This is a comprehensive patch for FC-FC4 provider. tcm_fc is a FC-FC4
provider which glues target core (TCM) with Fiber channel library
(libfc). tcm_fc uses existing FC4 provider hooks from Fiber channel
library. This Fiber channel library is used by FCoE (transport - FC
over Ethernet) protocol driver as well.

Combination of modules such as Fiber channel library, tcm_fc, TCM
target core, and FCoE protocol driver enables functional FCoE target.

This patch includes initial commit for tcm_fc plus additional
enhancement, bug fixes.

This tcm_fc module essentially contains 3 entry points such as "prli",
"prlo", "recv".  When process login request (ELS_PRLI) request is
received, Fiber channel library (libfc) module calls passive providers
(FC-FC4, tcm_fc) (if any registered) "prli" function. Likewise when
LOGO request is received, "prlo" function of passive provider is
invoked by libfc.  For all other request (e.g. any read/write, task
management, LUN inquiry commands), "recv" function of passiver
provider is invoked by libfc. Those passive providers "prli, prlo,
recv" functions interact with TCM target core for requested operation.

This module was primarily developed by "Joe Eykholt" and there were
significant contributions from the people listed under signed-off.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NNicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NKiran Patil <kiran.patil@intel.com>
Acked-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <jbottomley@parallels.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>