diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2016-05-25 12:25:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-20 18:09:26 +0200 |
| commit | 60ba156dda2c11ff7a44d78ec64abd21b9813115 (patch) | |
| tree | 153237069818a29c034c0890b3c158cea424357f | |
| parent | 6492c1c5b95658bc070d5d231bc32568b84b49bb (diff) | |
target: Fix missing complete during ABORT_TASK + CMD_T_FABRIC_STOP
commit 5e2c956b8aa24d4f33ff7afef92d409eed164746 upstream.
During transport_generic_free_cmd() with a concurrent TMR
ABORT_TASK and shutdown CMD_T_FABRIC_STOP bit set, the
caller will be blocked on se_cmd->cmd_wait_stop completion
until the final kref_put() -> target_release_cmd_kref()
has been invoked to call complete().
However, when ABORT_TASK is completed with FUNCTION_COMPLETE
in core_tmr_abort_task(), the aborted se_cmd will have already
been removed from se_sess->sess_cmd_list via list_del_init().
This results in target_release_cmd_kref() hitting the
legacy list_empty() == true check, invoking ->release_cmd()
but skipping complete() to wakeup se_cmd->cmd_wait_stop
blocked earlier in transport_generic_free_cmd() code.
To address this bug, it's safe to go ahead and drop the
original list_empty() check so that fabric_stop invokes
the complete() as expected, since list_del_init() can
safely be used on a empty list.
Cc: Mike Christie <mchristi@redhat.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/target/target_core_transport.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 7f4cdc82234b..93fb7c0dfa3c 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2541,12 +2541,6 @@ static void target_release_cmd_kref(struct kref *kref) bool fabric_stop; spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); - if (list_empty(&se_cmd->se_cmd_list)) { - spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); - target_free_cmd_mem(se_cmd); - se_cmd->se_tfo->release_cmd(se_cmd); - return; - } spin_lock(&se_cmd->t_state_lock); fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP); |