From 6ec9d4d2310e8fc54fc638e4454271d1fcaefa95 Mon Sep 17 00:00:00 2001 From: Max Gurtovoy Date: Sun, 7 Dec 2014 16:09:56 +0200 Subject: [PATCH] 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 Signed-off-by: Sagi Grimberg Signed-off-by: Or Gerlitz Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/iser/iscsi_iser.h | 2 ++ drivers/infiniband/ulp/iser/iser_initiator.c | 6 +++--- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h index 44d64b74c365..8a5663dae87a 100644 --- a/drivers/infiniband/ulp/iser/iscsi_iser.h +++ b/drivers/infiniband/ulp/iser/iscsi_iser.h @@ -437,6 +437,7 @@ struct fast_reg_descriptor { * @cma_id: rdma_cm connection maneger handle * @qp: Connection Queue-pair * @post_recv_buf_count: post receive counter + * @sig_count: send work request signal count * @rx_wr: receive work request for batch posts * @device: reference to iser device * @comp: iser completion context @@ -457,6 +458,7 @@ struct ib_conn { struct rdma_cm_id *cma_id; struct ib_qp *qp; int post_recv_buf_count; + u8 sig_count; struct ib_recv_wr rx_wr[ISER_MIN_POSTED_RX]; struct iser_device *device; struct iser_comp *comp; diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c index 5a489ea63732..3821633f1065 100644 --- a/drivers/infiniband/ulp/iser/iser_initiator.c +++ b/drivers/infiniband/ulp/iser/iser_initiator.c @@ -369,7 +369,7 @@ static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req) 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 @@ int iser_send_command(struct iscsi_conn *conn, 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 @@ int iser_send_command(struct iscsi_conn *conn, 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; -- 2.20.1