| From 105fa2f44e504c830697b0c794822112d79808dc Mon Sep 17 00:00:00 2001 |
| From: Nicholas Bellinger <nab@linux-iscsi.org> |
| Date: Sat, 3 Jun 2017 05:35:47 -0700 |
| Subject: iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP |
| |
| From: Nicholas Bellinger <nab@linux-iscsi.org> |
| |
| commit 105fa2f44e504c830697b0c794822112d79808dc upstream. |
| |
| This patch fixes a BUG() in iscsit_close_session() that could be |
| triggered when iscsit_logout_post_handler() execution from within |
| tx thread context was not run for more than SECONDS_FOR_LOGOUT_COMP |
| (15 seconds), and the TCP connection didn't already close before |
| then forcing tx thread context to automatically exit. |
| |
| This would manifest itself during explicit logout as: |
| |
| [33206.974254] 1 connection(s) still exist for iSCSI session to iqn.1993-08.org.debian:01:3f5523242179 |
| [33206.980184] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 2100.772 msecs |
| [33209.078643] ------------[ cut here ]------------ |
| [33209.078646] kernel BUG at drivers/target/iscsi/iscsi_target.c:4346! |
| |
| Normally when explicit logout attempt fails, the tx thread context |
| exits and iscsit_close_connection() from rx thread context does the |
| extra cleanup once it detects conn->conn_logout_remove has not been |
| cleared by the logout type specific post handlers. |
| |
| To address this special case, if the logout post handler in tx thread |
| context detects conn->tx_thread_active has already been cleared, simply |
| return and exit in order for existing iscsit_close_connection() |
| logic from rx thread context do failed logout cleanup. |
| |
| Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> |
| Tested-by: Bart Van Assche <bart.vanassche@sandisk.com> |
| Cc: Mike Christie <mchristi@redhat.com> |
| Cc: Hannes Reinecke <hare@suse.de> |
| Cc: Sagi Grimberg <sagig@mellanox.com> |
| Tested-by: Gary Guo <ghg@datera.io> |
| Tested-by: Chu Yuan Lin <cyl@datera.io> |
| Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| |
| --- |
| drivers/target/iscsi/iscsi_target.c | 10 ++++++++-- |
| 1 file changed, 8 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/target/iscsi/iscsi_target.c |
| +++ b/drivers/target/iscsi/iscsi_target.c |
| @@ -4591,8 +4591,11 @@ static void iscsit_logout_post_handler_c |
| * always sleep waiting for RX/TX thread shutdown to complete |
| * within iscsit_close_connection(). |
| */ |
| - if (conn->conn_transport->transport_type == ISCSI_TCP) |
| + if (conn->conn_transport->transport_type == ISCSI_TCP) { |
| sleep = cmpxchg(&conn->tx_thread_active, true, false); |
| + if (!sleep) |
| + return; |
| + } |
| |
| atomic_set(&conn->conn_logout_remove, 0); |
| complete(&conn->conn_logout_comp); |
| @@ -4608,8 +4611,11 @@ static void iscsit_logout_post_handler_s |
| { |
| int sleep = 1; |
| |
| - if (conn->conn_transport->transport_type == ISCSI_TCP) |
| + if (conn->conn_transport->transport_type == ISCSI_TCP) { |
| sleep = cmpxchg(&conn->tx_thread_active, true, false); |
| + if (!sleep) |
| + return; |
| + } |
| |
| atomic_set(&conn->conn_logout_remove, 0); |
| complete(&conn->conn_logout_comp); |