If on an initiator system a LUN reset is issued while I/O is in progress with queue depth > 1, avoid that data corruption occurs as follows: - The initiator submits a READ (a). - The initiator submits a LUN reset before READ (a) completes. - The target responds that the LUN reset succeeded after READ (a) has been marked as CMD_T_COMPLETE and before .queue_status() has been called. - The initiator receives the LUN reset response and frees the tag used by READ (a). - The initiator submits READ (b) and reuses the tag of READ (a). - The initiator receives the response for READ (a) and interprets this as a completion for READ (b). - The initiator receives the completion for READ (b) and discards it.
With the SRP initiator and target drivers and when running fio concurrently with sg_reset -d it only takes a few minutes to reproduce this.
Signed-off-by: Bart Van Assche bvanassche@acm.org Fixes: commit febe562c20df ("target: Fix LUN_RESET active I/O handling for ACK_KREF") Cc: Nicholas Bellinger nab@linux-iscsi.org Cc: Mike Christie mchristi@redhat.com Cc: Christoph Hellwig hch@lst.de Cc: Hannes Reinecke hare@suse.de Cc: stable@vger.kernel.org --- drivers/target/target_core_tmr.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c index 2750a2c7b563..6e419396c1e4 100644 --- a/drivers/target/target_core_tmr.c +++ b/drivers/target/target_core_tmr.c @@ -90,7 +90,7 @@ static int target_check_cdb_and_preempt(struct list_head *list, return 1; }
-static bool __target_check_io_state(struct se_cmd *se_cmd, +static bool __target_check_io_state(struct se_cmd *se_cmd, u32 skip_flags, struct se_session *tmr_sess, int tas) { struct se_session *sess = se_cmd->se_sess; @@ -108,7 +108,7 @@ static bool __target_check_io_state(struct se_cmd *se_cmd, * long as se_cmd->cmd_kref is still active unless zero. */ spin_lock(&se_cmd->t_state_lock); - if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { + if (se_cmd->transport_state & (skip_flags | CMD_T_FABRIC_STOP)) { pr_debug("Attempted to abort io tag: %llu already complete or" " fabric stop, skipping\n", se_cmd->tag); spin_unlock(&se_cmd->t_state_lock); @@ -165,7 +165,8 @@ void core_tmr_abort_task( printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", se_cmd->se_tfo->get_fabric_name(), ref_tag);
- if (!__target_check_io_state(se_cmd, se_sess, 0)) + if (!__target_check_io_state(se_cmd, CMD_T_COMPLETE, se_sess, + 0)) continue;
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); @@ -349,7 +350,7 @@ static void core_tmr_drain_state_list( continue;
spin_lock(&sess->sess_cmd_lock); - rc = __target_check_io_state(cmd, tmr_sess, tas); + rc = __target_check_io_state(cmd, 0, tmr_sess, tas); spin_unlock(&sess->sess_cmd_lock); if (!rc) continue;