linux.git/include/target, branch v4.13.7

iscsi-target: Fix iscsi_np reset hung task during parallel delete

2017-08-06T21:41:41+00:00

This patch fixes a bug associated with iscsit_reset_np_thread()
that can occur during parallel configfs rmdir of a single iscsi_np
used across multiple iscsi-target instances, that would result in
hung task(s) similar to below where configfs rmdir process context
was blocked indefinately waiting for iscsi_np->np_restart_comp
to finish:

[ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds.
[ 6726.119440]       Tainted: G        W  O     4.1.26-3321 #2
[ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88     0 15550      1 0x00000000
[ 6726.140058]  ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08
[ 6726.147593]  ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0
[ 6726.155132]  ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8
[ 6726.162667] Call Trace:
[ 6726.165150]  [] schedule+0x32/0x80
[ 6726.170156]  [] schedule_timeout+0x214/0x290
[ 6726.176030]  [] ? __send_signal+0x52/0x4a0
[ 6726.181728]  [] wait_for_completion+0x96/0x100
[ 6726.187774]  [] ? wake_up_state+0x10/0x10
[ 6726.193395]  [] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod]
[ 6726.201278]  [] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod]
[ 6726.210033]  [] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod]
[ 6726.218351]  [] configfs_write_file+0xaa/0x110
[ 6726.224392]  [] vfs_write+0xa4/0x1b0
[ 6726.229576]  [] SyS_write+0x41/0xb0
[ 6726.234659]  [] system_call_fastpath+0x12/0x71

It would happen because each iscsit_reset_np_thread() sets state
to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting
for completion on iscsi_np->np_restart_comp.

However, if iscsi_np was active processing a login request and
more than a single iscsit_reset_np_thread() caller to the same
iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np
kthread process context in __iscsi_target_login_thread() would
flush pending signals and only perform a single completion of
np->np_restart_comp before going back to sleep within transport
specific iscsit_transport->iscsi_accept_np code.

To address this bug, add a iscsi_np->np_reset_count and update
__iscsi_target_login_thread() to keep completing np->np_restart_comp
until ->np_reset_count has reached zero.

Reported-by: Gary Guo 
Tested-by: Gary Guo 
Cc: Mike Christie 
Cc: Hannes Reinecke 
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger

iscsi-target: Add login_keys_workaround attribute for non RFC initiators

2017-07-11T17:56:39+00:00

This patch re-introduces part of a long standing login workaround that
was recently dropped by:

  commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46
  Author: Nicholas Bellinger 
  Date:   Sun Apr 2 13:36:44 2017 -0700

      iscsi-target: Drop work-around for legacy GlobalSAN initiator

Namely, the workaround for FirstBurstLength ended up being required by
Mellanox Flexboot PXE boot ROMs as reported by Robert.

So this patch re-adds the work-around for FirstBurstLength within
iscsi_check_proposer_for_optional_reply(), and makes the key optional
to respond when the initiator does not propose, nor respond to it.

Also as requested by Arun, this patch introduces a new TPG attribute
named 'login_keys_workaround' that controls the use of both the
FirstBurstLength workaround, as well as the two other existing
workarounds for gPXE iSCSI boot client.

By default, the workaround is enabled with login_keys_workaround=1,
since Mellanox FlexBoot requires it, and Arun has verified the Qlogic
MSFT initiator already proposes FirstBurstLength, so it's uneffected
by this re-adding this part of the original work-around.

Reported-by: Robert LeBlanc 
Cc: Robert LeBlanc 
Reviewed-by: Arun Easi 
Cc:  # 3.1+
Signed-off-by: Nicholas Bellinger

target: remove transport_complete

2017-07-07T06:11:47+00:00

transport_complete is no longer used, so drop the code.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

target: add helper to copy sense to se_cmd buffer

2017-07-07T06:11:45+00:00

This adds a helper to copy sense from backend module buffer to
the se_cmd's sense buffer.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

target: remove g_device_list

2017-07-07T06:11:41+00:00

g_device_list is no longer needed because we now use the idr code
for lookups and seaches.

Signed-off-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger

target: add helper to find se_device by dev_index

2017-07-07T06:11:38+00:00

This adds a helper to find a se_device by dev_index. It will
be used in the next patches so tcmu's netlink interface can
execute commands on specific devices.

Signed-off-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger

target: use idr for se_device dev index

2017-07-07T06:11:37+00:00

In the next patches we will add tcmu netlink support that allows
userspace to send commands to target_core_user. To execute operations
on a se_device/tcmu_dev we need to be able to look up a dev by any old
id. This patch replaces the se_device->dev_index with a idr created
id.

The next patches will also remove the g_device_list and replace it with
the idr.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

target: break up free_device callback

2017-07-07T06:11:37+00:00

With this patch free_device is now used to free what is allocated in the
alloc_device callback and destroy_device tears down the resources that are
setup in the configure_device callback.

This patch will be needed in the next patch where tcmu needs
to be able to look up the device in the destroy callback.

Signed-off-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger

target: Introduce a function that shows the command state

2017-07-07T05:58:04+00:00

Introduce target_show_cmd() and use it where appropriate. If
transport_wait_for_tasks() takes too long, make it show the
state of the command it is waiting for.

(Add missing brackets around multi-line conditions - nab)

Signed-off-by: Bart Van Assche 
Cc: Hannes Reinecke 
Cc: Christoph Hellwig 
Cc: Andy Grover 
Cc: David Disseldorp 
Signed-off-by: Nicholas Bellinger

iscsi-target: Kill left-over iscsi_target_do_cleanup

2017-07-07T05:58:04+00:00

With commit 25cdda95fda7 in place to address the initial login
PDU asynchronous socket close OOPs, go ahead and kill off the
left-over iscsi_target_do_cleanup() and ->login_cleanup_work.

Reported-by: Mike Christie 
Cc: Mike Christie 
Signed-off-by: Nicholas Bellinger