diff options
author | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-05-15 00:52:44 -0700 |
---|---|---|
committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-05-29 21:30:33 -0700 |
commit | 9b31a328e344e62e7cc98ae574edcb7b674719bb (patch) | |
tree | 07baf7e2854dcd8f08066e7285ee68a89a4b9ff8 | |
parent | be646c2d2ba8e2e56596d72633705f8286698c25 (diff) | |
download | linux-9b31a328e344e62e7cc98ae574edcb7b674719bb.tar.bz2 |
target: Re-instate sess_wait_list for target_wait_for_sess_cmds
Switch back to pre commit 1c7b13fe652 list splicing logic for active I/O
shutdown with tcm_qla2xxx + ib_srpt fabrics.
The original commit was done under the incorrect assumption that it's safe to
walk se_sess->sess_cmd_list unprotected in target_wait_for_sess_cmds() after
sess->sess_tearing_down = 1 has been set by target_sess_cmd_list_set_waiting()
during session shutdown.
So instead of adding sess->sess_cmd_lock protection around sess->sess_cmd_list
during target_wait_for_sess_cmds(), switch back to sess->sess_wait_list to
allow wait_for_completion() + TFO->release_cmd() to occur without having to
walk ->sess_cmd_list after the list_splice.
Also add a check to exit if target_sess_cmd_list_set_waiting() has already
been called, and add a WARN_ON to check for any fabric bug where new se_cmds
are added to sess->sess_cmd_list after sess->sess_tearing_down = 1 has already
been set.
Cc: Joern Engel <joern@logfs.org>
Cc: Roland Dreier <roland@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
-rw-r--r-- | drivers/target/target_core_transport.c | 18 | ||||
-rw-r--r-- | include/target/target_core_base.h | 1 |
2 files changed, 15 insertions, 4 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 311c11349aab..bbca144821c5 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -221,6 +221,7 @@ struct se_session *transport_init_session(void) INIT_LIST_HEAD(&se_sess->sess_list); INIT_LIST_HEAD(&se_sess->sess_acl_list); INIT_LIST_HEAD(&se_sess->sess_cmd_list); + INIT_LIST_HEAD(&se_sess->sess_wait_list); spin_lock_init(&se_sess->sess_cmd_lock); kref_init(&se_sess->sess_kref); @@ -2250,11 +2251,14 @@ void target_sess_cmd_list_set_waiting(struct se_session *se_sess) unsigned long flags; spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); - - WARN_ON(se_sess->sess_tearing_down); + if (se_sess->sess_tearing_down) { + spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + return; + } se_sess->sess_tearing_down = 1; + list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list); - list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) + list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) se_cmd->cmd_wait_set = 1; spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); @@ -2267,9 +2271,10 @@ EXPORT_SYMBOL(target_sess_cmd_list_set_waiting); void target_wait_for_sess_cmds(struct se_session *se_sess) { struct se_cmd *se_cmd, *tmp_cmd; + unsigned long flags; list_for_each_entry_safe(se_cmd, tmp_cmd, - &se_sess->sess_cmd_list, se_cmd_list) { + &se_sess->sess_wait_list, se_cmd_list) { list_del(&se_cmd->se_cmd_list); pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:" @@ -2283,6 +2288,11 @@ void target_wait_for_sess_cmds(struct se_session *se_sess) se_cmd->se_tfo->release_cmd(se_cmd); } + + spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); + WARN_ON(!list_empty(&se_sess->sess_cmd_list)); + spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + } EXPORT_SYMBOL(target_wait_for_sess_cmds); diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index e773dfa5f98f..4ea4f985f394 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -543,6 +543,7 @@ struct se_session { struct list_head sess_list; struct list_head sess_acl_list; struct list_head sess_cmd_list; + struct list_head sess_wait_list; spinlock_t sess_cmd_lock; struct kref sess_kref; }; |