linux.git/drivers/target/tcm_fc, branch v3.12 Linux kernel source tree target: replace strict_strto*() with kstrto*() 2013-08-13T03:31:44+00:00 Jingoo Han jg1.han@samsung.com 2013-07-19T07:22:19+00:00 57103d7fe1833857cf542a482c1eb8da0bf86e5d The usage of strict_strtoul() and strict_strtoull() is not preferred, because strict_strtoul() and strict_strtoull() are obsolete. Thus, kstrtoul() and kstrtoull() should be used. v2: Fix incorrect return in ft_add_tpg (Fengguang) Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
The usage of strict_strtoul() and strict_strtoull() is not preferred,
because strict_strtoul() and strict_strtoull() are obsolete. Thus,
kstrtoul() and kstrtoull() should be used.

v2: Fix incorrect return in ft_add_tpg (Fengguang)

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
target: make queue_tm_rsp() return void 2013-07-08T01:36:53+00:00 Joern Engel joern@logfs.org 2013-07-03T15:22:17+00:00 b79fafac70fc9bbe640b8193ed772eb850efdfe6 The return value wasn't checked by any of the callers. Assuming this is correct behaviour, we can simplify some code by not bothering to generate it. nab: Add srpt_queue_data_in() + srpt_queue_tm_rsp() nops around srpt_queue_response() void return Signed-off-by: Joern Engel <joern@logfs.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
The return value wasn't checked by any of the callers.  Assuming this is
correct behaviour, we can simplify some code by not bothering to
generate it.

nab: Add srpt_queue_data_in() + srpt_queue_tm_rsp() nops around
     srpt_queue_response() void return

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
target: remove unused codes from enum tcm_tmrsp_table 2013-07-08T01:36:52+00:00 Joern Engel joern@logfs.org 2013-07-03T15:22:16+00:00 11fee8a751670cf6d60b1912e2e9cb1c7e392842 Three have been checked for but were never set. Remove the dead code. Also renumbers the remaining ones to a) get rid of the holes after the removal and b) avoid a collision between TMR_FUNCTION_COMPLETE==0 and the uninitialized case. If we failed to set a code, we should rather fall into the default case then return success. Signed-off-by: Joern Engel <joern@logfs.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
Three have been checked for but were never set.  Remove the dead code.
Also renumbers the remaining ones to a) get rid of the holes after the
removal and b) avoid a collision between TMR_FUNCTION_COMPLETE==0 and
the uninitialized case.  If we failed to set a code, we should rather
fall into the default case then return success.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
tcm_fc: Check for aborted sequence 2013-04-25T08:05:28+00:00 Mark Rustad mark.d.rustad@intel.com 2013-04-22T16:49:55+00:00 d3682b1aeba088957a210e3abc2c71dba63d6def Add a check for an aborted sequence, which has a NULL sequence pointer, to avoid target crashes. The most relevant messages from the crash (entered from video capture) include: BUG: unable to handle kernel paging request at ffffffffffffffdf IP: [<ffffffffa02d514c>] fc_seq_send+0x3c/0x150 [libfc] ... Call Trace: [<ffffffffa0443de6>] ft_queue_data_in+0x266/0x560 [tcm_fc] Signed-off-by: Mark Rustad <mark.d.rustad@intel.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
Add a check for an aborted sequence, which has a
NULL sequence pointer, to avoid target crashes.
The most relevant messages from the crash (entered
from video capture) include:

BUG: unable to handle kernel paging request at ffffffffffffffdf
IP: [<ffffffffa02d514c>] fc_seq_send+0x3c/0x150 [libfc]
...
Call Trace:
 [<ffffffffa0443de6>] ft_queue_data_in+0x266/0x560 [tcm_fc]

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
tcm_fc: using kfree_rcu() to simplify the code 2013-04-25T08:05:23+00:00 Wei Yongjun yongjun_wei@trendmicro.com.cn 2013-03-11T13:48:28+00:00 a6ad57efc39ca0ed58733f13f658ac14317a90ba 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: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
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: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
hlist: drop the node parameter from iterators 2013-02-28T03:10:24+00:00 Sasha Levin sasha.levin@oracle.com 2013-02-28T01:06:00+00:00 b67bfe0d42cac56c512dd5da4b1b347a23f4b70a 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: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tcm_fc: Do not report target role when target is not defined 2013-01-11T04:08:58+00:00 Mark Rustad mark.d.rustad@intel.com 2012-12-21T18:58:19+00:00 edec8dfefa1f372b2dd8197da555352e76a10c03 Clear the target role when no target is provided for the node performing a PRLI. Signed-off-by: Mark Rustad <mark.d.rustad@intel.com> Reviewed-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com> Acked by Robert Love <robert.w.love@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
Clear the target role when no target is provided for
the node performing a PRLI.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Reviewed-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Acked by Robert Love <robert.w.love@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
tcm_fc: Do not indicate retry capability to initiators 2013-01-11T04:07:47+00:00 Mark Rustad mark.d.rustad@intel.com 2012-12-21T18:58:14+00:00 f2eeba214bcd0215b7f558cab6420e5fd153042b When generating a PRLI response to an initiator, clear the FCP_SPPF_RETRY bit in the response. Signed-off-by: Mark Rustad <mark.d.rustad@intel.com> Reviewed-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com> Acked by Robert Love <robert.w.love@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Nicholas 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: Mark Rustad <mark.d.rustad@intel.com>
Reviewed-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Acked by Robert Love <robert.w.love@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
target/tcm_fc: fix the lockdep warning due to inconsistent lock state 2012-12-13T05:18:01+00:00 Yi Zou yi.zou@intel.com 2012-12-11T01:04:00+00:00 9f4ad44b264f8bb61ffdd607148215566568430d 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: Yi 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: Nicholas 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: Yi 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: Nicholas Bellinger <nab@linux-iscsi.org>
tcm_fc: move the dereference below the NULL test 2012-09-18T01:04:09+00:00 Wei Yongjun yongjun_wei@trendmicro.com.cn 2012-09-07T06:55:32+00:00 7875f179085608c659b676be74d33a2e515d8f43 The dereference should be moved below the NULL test. spatch with a semantic match is used to found this. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> 
The dereference should be moved below the NULL test.

spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>