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 <bart.vanassche@xxxxxxxxxxx>
Fixes: commit febe562c20df ("target: Fix LUN_RESET active I/O handling for ACK_KREF")
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Andy Grover <agrover@xxxxxxxxxx>
Cc: David Disseldorp <ddiss@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
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 32ea7c61d6ac..16e748eb32d2 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -109,7 +109,7 @@ 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;
@@ -127,7 +127,7 @@ 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);
@@ -182,7 +182,8 @@ 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;
list_del_init(&se_cmd->se_cmd_list);
@@ -354,7 +355,7 @@ 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;
--
2.11.0