diff options
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/ulp/iser/iscsi_iser.c | 169 |
1 files changed, 160 insertions, 9 deletions
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c index decf696e7ea5..8c04c2d3cfd9 100644 --- a/drivers/infiniband/ulp/iser/iscsi_iser.c +++ b/drivers/infiniband/ulp/iser/iscsi_iser.c @@ -102,9 +102,19 @@ MODULE_PARM_DESC(pi_guard, "T10-PI guard_type, 0:CRC|1:IP_CSUM (default:CRC)"); static struct workqueue_struct *release_wq; struct iser_global ig; +/* + * iscsi_iser_recv() - Process a successfull recv completion + * @conn: iscsi connection + * @hdr: iscsi header + * @rx_data: buffer containing receive data payload + * @rx_data_len: length of rx_data + * + * Notes: In case of data length errors or iscsi PDU completion failures + * this routine will signal iscsi layer of connection failure. + */ void -iscsi_iser_recv(struct iscsi_conn *conn, - struct iscsi_hdr *hdr, char *rx_data, int rx_data_len) +iscsi_iser_recv(struct iscsi_conn *conn, struct iscsi_hdr *hdr, + char *rx_data, int rx_data_len) { int rc = 0; int datalen; @@ -135,12 +145,22 @@ error: iscsi_conn_failure(conn, rc); } -static int iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode) +/** + * iscsi_iser_pdu_alloc() - allocate an iscsi-iser PDU + * @task: iscsi task + * @opcode: iscsi command opcode + * + * Netes: This routine can't fail, just assign iscsi task + * hdr and max hdr size. + */ +static int +iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode) { struct iscsi_iser_task *iser_task = task->dd_data; task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header; task->hdr_max = sizeof(iser_task->desc.iscsi_header); + return 0; } @@ -165,11 +185,15 @@ int iser_initialize_task_headers(struct iscsi_task *task, iser_task->iser_conn = iser_conn; return 0; } + /** - * iscsi_iser_task_init - Initialize task + * iscsi_iser_task_init() - Initialize iscsi-iser task * @task: iscsi task * * Initialize the task for the scsi command or mgmt command. + * + * Return: Returns zero on success or -ENOMEM when failing + * to init task headers (dma mapping error). */ static int iscsi_iser_task_init(struct iscsi_task *task) @@ -191,7 +215,7 @@ iscsi_iser_task_init(struct iscsi_task *task) } /** - * iscsi_iser_mtask_xmit - xmit management(immediate) task + * iscsi_iser_mtask_xmit() - xmit management (immediate) task * @conn: iscsi connection * @task: task management task * @@ -249,6 +273,12 @@ iscsi_iser_task_xmit_unsol_data_exit: return error; } +/** + * iscsi_iser_task_xmit() - xmit iscsi-iser task + * @task: iscsi task + * + * Return: zero on success or escalates $error on failure. + */ static int iscsi_iser_task_xmit(struct iscsi_task *task) { @@ -286,6 +316,14 @@ iscsi_iser_task_xmit(struct iscsi_task *task) return error; } +/** + * iscsi_iser_cleanup_task() - cleanup an iscsi-iser task + * @task: iscsi task + * + * Notes: In case the RDMA device is already NULL (might have + * been removed in DEVICE_REMOVAL CM event it will bail-out + * without doing dma unmapping. + */ static void iscsi_iser_cleanup_task(struct iscsi_task *task) { struct iscsi_iser_task *iser_task = task->dd_data; @@ -310,7 +348,20 @@ static void iscsi_iser_cleanup_task(struct iscsi_task *task) } } -static u8 iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector) +/** + * iscsi_iser_check_protection() - check protection information status of task. + * @task: iscsi task + * @sector: error sector if exsists (output) + * + * Return: zero if no data-integrity errors have occured + * 0x1: data-integrity error occured in the guard-block + * 0x2: data-integrity error occured in the reference tag + * 0x3: data-integrity error occured in the application tag + * + * In addition the error sector is marked. + */ +static u8 +iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector) { struct iscsi_iser_task *iser_task = task->dd_data; @@ -322,8 +373,17 @@ static u8 iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector) sector); } +/** + * iscsi_iser_conn_create() - create a new iscsi-iser connection + * @cls_session: iscsi class connection + * @conn_idx: connection index within the session (for MCS) + * + * Return: iscsi_cls_conn when iscsi_conn_setup succeeds or NULL + * otherwise. + */ static struct iscsi_cls_conn * -iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx) +iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, + uint32_t conn_idx) { struct iscsi_conn *conn; struct iscsi_cls_conn *cls_conn; @@ -342,9 +402,21 @@ iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx) return cls_conn; } +/** + * iscsi_iser_conn_bind() - bind iscsi and iser connection structures + * @cls_session: iscsi class session + * @cls_conn: iscsi class connection + * @transport_eph: transport end-point handle + * @is_leading: indicate if this is the session leading connection (MCS) + * + * Return: zero on success, $error if iscsi_conn_bind fails and + * -EINVAL in case end-point doesn't exsits anymore or iser connection + * state is not UP (teardown already started). + */ static int iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session, - struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, + struct iscsi_cls_conn *cls_conn, + uint64_t transport_eph, int is_leading) { struct iscsi_conn *conn = cls_conn->dd_data; @@ -391,6 +463,14 @@ out: return error; } +/** + * iscsi_iser_conn_start() - start iscsi-iser connection + * @cls_conn: iscsi class connection + * + * Notes: Here iser intialize (or re-initialize) stop_completion as + * from this point iscsi must call conn_stop in session/connection + * teardown so iser transport must wait for it. + */ static int iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn) { @@ -404,6 +484,16 @@ iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn) return iscsi_conn_start(cls_conn); } +/** + * iscsi_iser_conn_stop() - stop iscsi-iser connection + * @cls_conn: iscsi class connection + * @flag: indicate if recover or terminate (passed as is) + * + * Notes: Calling iscsi_conn_stop might theoretically race with + * DEVICE_REMOVAL event and dereference a previously freed RDMA device + * handle, so we call it under iser the state lock to protect against + * this kind of race. + */ static void iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) { @@ -432,7 +522,14 @@ iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) } } -static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session) +/** + * iscsi_iser_session_destroy() - destroy iscsi-iser session + * @cls_session: iscsi class session + * + * Removes and free iscsi host. + */ +static void +iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session) { struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); @@ -452,6 +549,16 @@ iser_dif_prot_caps(int prot_caps) SHOST_DIX_TYPE3_PROTECTION : 0); } +/** + * iscsi_iser_session_create() - create an iscsi-iser session + * @ep: iscsi end-point handle + * @cmds_max: maximum commands in this session + * @qdepth: session command queue depth + * @initial_cmdsn: initiator command sequnce number + * + * Allocates and adds a scsi host, expose DIF supprot if + * exists, and sets up an iscsi session. + */ static struct iscsi_cls_session * iscsi_iser_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, uint16_t qdepth, @@ -564,6 +671,13 @@ iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn, return 0; } +/** + * iscsi_iser_set_param() - set class connection parameter + * @cls_conn: iscsi class connection + * @stats: iscsi stats to output + * + * Output connection statistics. + */ static void iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats) { @@ -612,6 +726,21 @@ static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep, return len; } +/** + * iscsi_iser_ep_connect() - Initiate iSER connection establishment + * @shost: scsi_host + * @dst_addr: destination address + * @non-blocking: indicate if routine can block + * + * Allocate an iscsi endpoint, an iser_conn structure and bind them. + * After that start RDMA connection establishment via rdma_cm. We + * don't allocate iser_conn embedded in iscsi_endpoint since in teardown + * the endpoint will be destroyed at ep_disconnect while iser_conn will + * cleanup its resources asynchronuously. + * + * Return: iscsi_endpoint created by iscsi layer or ERR_PTR(error) + * if fails. + */ static struct iscsi_endpoint * iscsi_iser_ep_connect(struct Scsi_Host *shost, struct sockaddr *dst_addr, int non_blocking) @@ -644,6 +773,19 @@ failure: return ERR_PTR(err); } +/** + * iscsi_iser_ep_poll() - poll for iser connection establishment to complete + * @ep: iscsi endpoint (created at ep_connect) + * @timeout_ms: polling timeout allowed in ms. + * + * This routine boils down to waiting for up_completion signaling + * that cma_id got CONNECTED event. + * + * Return: 1 if succeeded in connection establishment, 0 if timeout expired + * (libiscsi will retry will kick in) or -1 if interrupted by signal + * or more likely iser connection state transitioned to TEMINATING or + * DOWN during the wait period. + */ static int iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms) { @@ -672,6 +814,15 @@ iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms) return rc; /* signal */ } +/** + * iscsi_iser_ep_disconnect() - Initiate connection teardown process + * @ep: iscsi endpoint handle + * + * This routine is not blocked by iser and RDMA termination process + * completion as we queue a deffered work for iser/RDMA destruction + * and cleanup or actually call it immediately in case we didn't pass + * iscsi conn bind/start stage, thus it is safe. + */ static void iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep) { |