IB/iser: Fix possible SQ overflow
Fix a regression was introduced in commit 6df5a128f0fd ("IB/iser:
Suppress scsi command send completions").
The sig_count was wrongly set to be static variable, thus it is
possible that we won't reach to (sig_count % ISER_SIGNAL_BATCH) == 0
condition (due to races) and the send queue will be overflowed.
Instead keep sig_count per connection. We don't need it to be atomic
as we are safe under the iscsi session frwd_lock taken by libiscsi on
the queuecommand path.
Fixes: 6df5a128f0fd ("IB/iser: Suppress scsi command send completions")
Signed-off-by: Max Gurtovoy <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>
Signed-off-by: Or Gerlitz <[email protected]>
Signed-off-by: Roland Dreier <[email protected]>
diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index 5a489ea..3821633 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -369,7 +369,7 @@
return 0;
}
-static inline bool iser_signal_comp(int sig_count)
+static inline bool iser_signal_comp(u8 sig_count)
{
return ((sig_count % ISER_SIGNAL_CMD_COUNT) == 0);
}
@@ -388,7 +388,7 @@
struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
struct scsi_cmnd *sc = task->sc;
struct iser_tx_desc *tx_desc = &iser_task->desc;
- static unsigned sig_count;
+ u8 sig_count = ++iser_conn->ib_conn.sig_count;
edtl = ntohl(hdr->data_length);
@@ -435,7 +435,7 @@
iser_task->status = ISER_TASK_STATUS_STARTED;
err = iser_post_send(&iser_conn->ib_conn, tx_desc,
- iser_signal_comp(++sig_count));
+ iser_signal_comp(sig_count));
if (!err)
return 0;
