iscsi-target: Always wait for kthread_should_stop() before kthread exit

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commit 5e0cf5e6c4 upstream.

There are three timing problems in the kthread usages of iscsi_target_mod:

 - np_thread of struct iscsi_np
 - rx_thread and tx_thread of struct iscsi_conn

In iscsit_close_connection(), it calls

 send_sig(SIGINT, conn->tx_thread, 1);
 kthread_stop(conn->tx_thread);

In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive
SIGINT the kthread will exit without checking the return value of
kthread_should_stop().

So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...)
and kthread_stop(...), the kthread_stop() will try to stop an already
stopped kthread.

This is invalid according to the documentation of kthread_stop().

(Fix -ECONNRESET logout handling in iscsi_target_tx_thread and
 early iscsi_target_rx_thread failure case - nab)

Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Jiang Yi 2017-05-16 17:57:55 +08:00 • committed by Greg Kroah-Hartman

parent ecbf0f48d6

commit 49d33fd100

4 changed files with 34 additions and 8 deletions

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30

drivers/target/iscsi/iscsi_target.c

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6

drivers/target/iscsi/iscsi_target_erl0.c

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2

drivers/target/iscsi/iscsi_target_erl0.h

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4

drivers/target/iscsi/iscsi_target_login.c

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