| From 6ec9d4d2310e8fc54fc638e4454271d1fcaefa95 Mon Sep 17 00:00:00 2001 |
| From: Max Gurtovoy <maxg@mellanox.com> |
| Date: Sun, 7 Dec 2014 16:09:56 +0200 |
| Subject: IB/iser: Fix possible SQ overflow |
| |
| From: Max Gurtovoy <maxg@mellanox.com> |
| |
| commit 6ec9d4d2310e8fc54fc638e4454271d1fcaefa95 upstream. |
| |
| 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 <maxg@mellanox.com> |
| Signed-off-by: Sagi Grimberg <sagig@mellanox.com> |
| Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> |
| Signed-off-by: Roland Dreier <roland@purestorage.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/infiniband/ulp/iser/iscsi_iser.h | 2 ++ |
| drivers/infiniband/ulp/iser/iser_initiator.c | 6 +++--- |
| 2 files changed, 5 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/infiniband/ulp/iser/iscsi_iser.h |
| +++ b/drivers/infiniband/ulp/iser/iscsi_iser.h |
| @@ -432,6 +432,7 @@ 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 |
| @@ -452,6 +453,7 @@ 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; |
| --- 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 iscs |
| 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 |
| 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 |
| 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; |
| |
