From 6f3c0e69a9c20441bdc6d3b2d18b83b244384ec6 Mon Sep 17 00:00:00 2001 From: Andy Grover Date: Tue, 3 Apr 2012 15:51:09 -0700 Subject: [PATCH] target/iscsi: Refactor target_tx_thread immediate+response queue loops Immediate queue: Consolidate down to one switch statement by moving send_tx_data and stuff from second switch into the first switch, or the functions the first switch calls. Response queue: Do not lock istate_lock except directly around i_state modifications. Put entire ISTATE_SEND_DATAIN path within first switch statement, in prep for further refactoring. All other cases set use_misc = 1 and will not be using sendpage, so just use send_tx_data for these and set use_misc param to 1. map_sg, sent_status, use_misc, and se_cmd vars no longer needed. Then put immediate and response handling in separate functions in order to get iscsi_target_tx_thread down to where it fits on a page. Signed-off-by: Andy Grover Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target.c | 487 ++++++++++++++-------------- drivers/target/iscsi/iscsi_target.h | 1 - 2 files changed, 244 insertions(+), 244 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 8428fa51beed..fd2b6381cb48 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -2434,10 +2434,19 @@ static int iscsit_send_conn_drop_async_message( return 0; } +static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn) +{ + if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) || + (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) { + wait_for_completion_interruptible_timeout( + &conn->tx_half_close_comp, + ISCSI_TX_THREAD_TCP_TIMEOUT * HZ); + } +} + static int iscsit_send_data_in( struct iscsi_cmd *cmd, - struct iscsi_conn *conn, - int *eodr) + struct iscsi_conn *conn) { int iov_ret = 0, set_statsn = 0; u32 iov_count = 0, tx_size = 0; @@ -2445,6 +2454,8 @@ static int iscsit_send_data_in( struct iscsi_datain_req *dr; struct iscsi_data_rsp *hdr; struct kvec *iov; + int eodr = 0; + int ret; memset(&datain, 0, sizeof(struct iscsi_datain)); dr = iscsit_get_datain_values(cmd, &datain); @@ -2577,13 +2588,26 @@ static int iscsit_send_data_in( cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn), ntohl(hdr->offset), datain.length, conn->cid); + /* sendpage is preferred but can't insert markers */ + if (!conn->conn_ops->IFMarker) + ret = iscsit_fe_sendpage_sg(cmd, conn); + else + ret = iscsit_send_tx_data(cmd, conn, 0); + + iscsit_unmap_iovec(cmd); + + if (ret < 0) { + iscsit_tx_thread_wait_for_tcp(conn); + return ret; + } + if (dr->dr_complete) { - *eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ? + eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ? 2 : 1; iscsit_free_datain_req(cmd, dr); } - return 0; + return eodr; } static int iscsit_send_logout_response( @@ -2715,6 +2739,7 @@ static int iscsit_send_unsolicited_nopin( { int tx_size = ISCSI_HDR_LEN; struct iscsi_nopin *hdr; + int ret; hdr = (struct iscsi_nopin *) cmd->pdu; memset(hdr, 0, ISCSI_HDR_LEN); @@ -2747,6 +2772,17 @@ static int iscsit_send_unsolicited_nopin( pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:" " 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid); + ret = iscsit_send_tx_data(cmd, conn, 1); + if (ret < 0) { + iscsit_tx_thread_wait_for_tcp(conn); + return ret; + } + + spin_lock_bh(&cmd->istate_lock); + cmd->i_state = want_response ? + ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS; + spin_unlock_bh(&cmd->istate_lock); + return 0; } @@ -2837,13 +2873,14 @@ static int iscsit_send_nopin_response( return 0; } -int iscsit_send_r2t( +static int iscsit_send_r2t( struct iscsi_cmd *cmd, struct iscsi_conn *conn) { int tx_size = 0; struct iscsi_r2t *r2t; struct iscsi_r2t_rsp *hdr; + int ret; r2t = iscsit_get_r2t_from_list(cmd); if (!r2t) @@ -2899,6 +2936,16 @@ int iscsit_send_r2t( r2t->sent_r2t = 1; spin_unlock_bh(&cmd->r2t_lock); + ret = iscsit_send_tx_data(cmd, conn, 1); + if (ret < 0) { + iscsit_tx_thread_wait_for_tcp(conn); + return ret; + } + + spin_lock_bh(&cmd->dataout_timeout_lock); + iscsit_start_dataout_timer(cmd, conn); + spin_unlock_bh(&cmd->dataout_timeout_lock); + return 0; } @@ -3407,16 +3454,6 @@ static int iscsit_send_reject( return 0; } -static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn) -{ - if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) || - (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) { - wait_for_completion_interruptible_timeout( - &conn->tx_half_close_comp, - ISCSI_TX_THREAD_TCP_TIMEOUT * HZ); - } -} - void iscsit_thread_get_cpumask(struct iscsi_conn *conn) { struct iscsi_thread_set *ts = conn->thread_set; @@ -3472,17 +3509,193 @@ static inline void iscsit_thread_check_cpumask( set_cpus_allowed_ptr(p, conn->conn_cpumask); } +static int handle_immediate_queue(struct iscsi_conn *conn) +{ + struct iscsi_queue_req *qr; + struct iscsi_cmd *cmd; + u8 state; + int ret; + + while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) { + atomic_set(&conn->check_immediate_queue, 0); + cmd = qr->cmd; + state = qr->state; + kmem_cache_free(lio_qr_cache, qr); + + switch (state) { + case ISTATE_SEND_R2T: + ret = iscsit_send_r2t(cmd, conn); + if (ret < 0) + goto err; + break; + case ISTATE_REMOVE: + if (cmd->data_direction == DMA_TO_DEVICE) + iscsit_stop_dataout_timer(cmd); + + spin_lock_bh(&conn->cmd_lock); + list_del(&cmd->i_conn_node); + spin_unlock_bh(&conn->cmd_lock); + + iscsit_free_cmd(cmd); + continue; + case ISTATE_SEND_NOPIN_WANT_RESPONSE: + iscsit_mod_nopin_response_timer(conn); + ret = iscsit_send_unsolicited_nopin(cmd, + conn, 1); + if (ret < 0) + goto err; + break; + case ISTATE_SEND_NOPIN_NO_RESPONSE: + ret = iscsit_send_unsolicited_nopin(cmd, + conn, 0); + if (ret < 0) + goto err; + break; + default: + pr_err("Unknown Opcode: 0x%02x ITT:" + " 0x%08x, i_state: %d on CID: %hu\n", + cmd->iscsi_opcode, cmd->init_task_tag, state, + conn->cid); + goto err; + } + } + + return 0; + +err: + return -1; +} + +static int handle_response_queue(struct iscsi_conn *conn) +{ + struct iscsi_queue_req *qr; + struct iscsi_cmd *cmd; + u8 state; + int ret; + + while ((qr = iscsit_get_cmd_from_response_queue(conn))) { + cmd = qr->cmd; + state = qr->state; + kmem_cache_free(lio_qr_cache, qr); + +check_rsp_state: + switch (state) { + case ISTATE_SEND_DATAIN: + ret = iscsit_send_data_in(cmd, conn); + if (ret < 0) + goto err; + else if (!ret) + /* more drs */ + goto check_rsp_state; + else if (ret == 1) { + /* all done */ + spin_lock_bh(&cmd->istate_lock); + cmd->i_state = ISTATE_SENT_STATUS; + spin_unlock_bh(&cmd->istate_lock); + continue; + } else if (ret == 2) { + /* Still must send status, + SCF_TRANSPORT_TASK_SENSE was set */ + spin_lock_bh(&cmd->istate_lock); + cmd->i_state = ISTATE_SEND_STATUS; + spin_unlock_bh(&cmd->istate_lock); + state = ISTATE_SEND_STATUS; + goto check_rsp_state; + } + + break; + case ISTATE_SEND_STATUS: + case ISTATE_SEND_STATUS_RECOVERY: + ret = iscsit_send_status(cmd, conn); + break; + case ISTATE_SEND_LOGOUTRSP: + ret = iscsit_send_logout_response(cmd, conn); + break; + case ISTATE_SEND_ASYNCMSG: + ret = iscsit_send_conn_drop_async_message( + cmd, conn); + break; + case ISTATE_SEND_NOPIN: + ret = iscsit_send_nopin_response(cmd, conn); + break; + case ISTATE_SEND_REJECT: + ret = iscsit_send_reject(cmd, conn); + break; + case ISTATE_SEND_TASKMGTRSP: + ret = iscsit_send_task_mgt_rsp(cmd, conn); + if (ret != 0) + break; + ret = iscsit_tmr_post_handler(cmd, conn); + if (ret != 0) + iscsit_fall_back_to_erl0(conn->sess); + break; + case ISTATE_SEND_TEXTRSP: + ret = iscsit_send_text_rsp(cmd, conn); + break; + default: + pr_err("Unknown Opcode: 0x%02x ITT:" + " 0x%08x, i_state: %d on CID: %hu\n", + cmd->iscsi_opcode, cmd->init_task_tag, + state, conn->cid); + goto err; + } + if (ret < 0) + goto err; + + if (iscsit_send_tx_data(cmd, conn, 1) < 0) { + iscsit_tx_thread_wait_for_tcp(conn); + iscsit_unmap_iovec(cmd); + goto err; + } + iscsit_unmap_iovec(cmd); + + switch (state) { + case ISTATE_SEND_LOGOUTRSP: + if (!iscsit_logout_post_handler(cmd, conn)) + goto restart; + /* fall through */ + case ISTATE_SEND_STATUS: + case ISTATE_SEND_ASYNCMSG: + case ISTATE_SEND_NOPIN: + case ISTATE_SEND_STATUS_RECOVERY: + case ISTATE_SEND_TEXTRSP: + case ISTATE_SEND_TASKMGTRSP: + spin_lock_bh(&cmd->istate_lock); + cmd->i_state = ISTATE_SENT_STATUS; + spin_unlock_bh(&cmd->istate_lock); + break; + case ISTATE_SEND_REJECT: + if (cmd->cmd_flags & ICF_REJECT_FAIL_CONN) { + cmd->cmd_flags &= ~ICF_REJECT_FAIL_CONN; + complete(&cmd->reject_comp); + goto err; + } + complete(&cmd->reject_comp); + break; + default: + pr_err("Unknown Opcode: 0x%02x ITT:" + " 0x%08x, i_state: %d on CID: %hu\n", + cmd->iscsi_opcode, cmd->init_task_tag, + cmd->i_state, conn->cid); + goto err; + } + + if (atomic_read(&conn->check_immediate_queue)) + break; + } + + return 0; + +err: + return -1; +restart: + return -EAGAIN; +} + int iscsi_target_tx_thread(void *arg) { - u8 state; - int eodr = 0; int ret = 0; - int sent_status = 0; - int use_misc = 0; - int map_sg = 0; - struct iscsi_cmd *cmd = NULL; struct iscsi_conn *conn; - struct iscsi_queue_req *qr = NULL; struct iscsi_thread_set *ts = arg; /* * Allow ourselves to be interrupted by SIGINT so that a @@ -3495,7 +3708,7 @@ int iscsi_target_tx_thread(void *arg) if (!conn) goto out; - eodr = map_sg = ret = sent_status = use_misc = 0; + ret = 0; while (!kthread_should_stop()) { /* @@ -3510,227 +3723,15 @@ int iscsi_target_tx_thread(void *arg) signal_pending(current)) goto transport_err; - while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) { - atomic_set(&conn->check_immediate_queue, 0); - cmd = qr->cmd; - state = qr->state; - kmem_cache_free(lio_qr_cache, qr); + ret = handle_immediate_queue(conn); + if (ret < 0) + goto transport_err; - switch (state) { - case ISTATE_SEND_R2T: - ret = iscsit_send_r2t(cmd, conn); - break; - case ISTATE_REMOVE: - if (cmd->data_direction == DMA_TO_DEVICE) - iscsit_stop_dataout_timer(cmd); - - spin_lock_bh(&conn->cmd_lock); - list_del(&cmd->i_conn_node); - spin_unlock_bh(&conn->cmd_lock); - - iscsit_free_cmd(cmd); - continue; - case ISTATE_SEND_NOPIN_WANT_RESPONSE: - iscsit_mod_nopin_response_timer(conn); - ret = iscsit_send_unsolicited_nopin(cmd, - conn, 1); - break; - case ISTATE_SEND_NOPIN_NO_RESPONSE: - ret = iscsit_send_unsolicited_nopin(cmd, - conn, 0); - break; - default: - pr_err("Unknown Opcode: 0x%02x ITT:" - " 0x%08x, i_state: %d on CID: %hu\n", - cmd->iscsi_opcode, cmd->init_task_tag, state, - conn->cid); - goto transport_err; - } - if (ret < 0) - goto transport_err; - - if (iscsit_send_tx_data(cmd, conn, 1) < 0) { - iscsit_tx_thread_wait_for_tcp(conn); - goto transport_err; - } - - switch (state) { - case ISTATE_SEND_R2T: - spin_lock_bh(&cmd->dataout_timeout_lock); - iscsit_start_dataout_timer(cmd, conn); - spin_unlock_bh(&cmd->dataout_timeout_lock); - break; - case ISTATE_SEND_NOPIN_WANT_RESPONSE: - spin_lock_bh(&cmd->istate_lock); - cmd->i_state = ISTATE_SENT_NOPIN_WANT_RESPONSE; - spin_unlock_bh(&cmd->istate_lock); - break; - case ISTATE_SEND_NOPIN_NO_RESPONSE: - spin_lock_bh(&cmd->istate_lock); - cmd->i_state = ISTATE_SENT_STATUS; - spin_unlock_bh(&cmd->istate_lock); - break; - default: - pr_err("Unknown Opcode: 0x%02x ITT:" - " 0x%08x, i_state: %d on CID: %hu\n", - cmd->iscsi_opcode, cmd->init_task_tag, - state, conn->cid); - goto transport_err; - } - } - - while ((qr = iscsit_get_cmd_from_response_queue(conn))) { - cmd = qr->cmd; - state = qr->state; - kmem_cache_free(lio_qr_cache, qr); - - spin_lock_bh(&cmd->istate_lock); -check_rsp_state: - switch (state) { - case ISTATE_SEND_DATAIN: - spin_unlock_bh(&cmd->istate_lock); - ret = iscsit_send_data_in(cmd, conn, - &eodr); - map_sg = 1; - break; - case ISTATE_SEND_STATUS: - case ISTATE_SEND_STATUS_RECOVERY: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_status(cmd, conn); - break; - case ISTATE_SEND_LOGOUTRSP: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_logout_response(cmd, conn); - break; - case ISTATE_SEND_ASYNCMSG: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_conn_drop_async_message( - cmd, conn); - break; - case ISTATE_SEND_NOPIN: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_nopin_response(cmd, conn); - break; - case ISTATE_SEND_REJECT: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_reject(cmd, conn); - break; - case ISTATE_SEND_TASKMGTRSP: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_task_mgt_rsp(cmd, conn); - if (ret != 0) - break; - ret = iscsit_tmr_post_handler(cmd, conn); - if (ret != 0) - iscsit_fall_back_to_erl0(conn->sess); - break; - case ISTATE_SEND_TEXTRSP: - spin_unlock_bh(&cmd->istate_lock); - use_misc = 1; - ret = iscsit_send_text_rsp(cmd, conn); - break; - default: - pr_err("Unknown Opcode: 0x%02x ITT:" - " 0x%08x, i_state: %d on CID: %hu\n", - cmd->iscsi_opcode, cmd->init_task_tag, - state, conn->cid); - spin_unlock_bh(&cmd->istate_lock); - goto transport_err; - } - if (ret < 0) - goto transport_err; - - if (map_sg && !conn->conn_ops->IFMarker) { - if (iscsit_fe_sendpage_sg(cmd, conn) < 0) { - iscsit_tx_thread_wait_for_tcp(conn); - iscsit_unmap_iovec(cmd); - goto transport_err; - } - } else { - if (iscsit_send_tx_data(cmd, conn, use_misc) < 0) { - iscsit_tx_thread_wait_for_tcp(conn); - iscsit_unmap_iovec(cmd); - goto transport_err; - } - } - map_sg = 0; - iscsit_unmap_iovec(cmd); - - spin_lock_bh(&cmd->istate_lock); - switch (state) { - case ISTATE_SEND_DATAIN: - if (!eodr) - goto check_rsp_state; - - if (eodr == 1) { - cmd->i_state = ISTATE_SENT_LAST_DATAIN; - sent_status = 1; - eodr = use_misc = 0; - } else if (eodr == 2) { - cmd->i_state = state = - ISTATE_SEND_STATUS; - sent_status = 0; - eodr = use_misc = 0; - goto check_rsp_state; - } - break; - case ISTATE_SEND_STATUS: - use_misc = 0; - sent_status = 1; - break; - case ISTATE_SEND_ASYNCMSG: - case ISTATE_SEND_NOPIN: - case ISTATE_SEND_STATUS_RECOVERY: - case ISTATE_SEND_TEXTRSP: - use_misc = 0; - sent_status = 1; - break; - case ISTATE_SEND_REJECT: - use_misc = 0; - if (cmd->cmd_flags & ICF_REJECT_FAIL_CONN) { - cmd->cmd_flags &= ~ICF_REJECT_FAIL_CONN; - spin_unlock_bh(&cmd->istate_lock); - complete(&cmd->reject_comp); - goto transport_err; - } - complete(&cmd->reject_comp); - break; - case ISTATE_SEND_TASKMGTRSP: - use_misc = 0; - sent_status = 1; - break; - case ISTATE_SEND_LOGOUTRSP: - spin_unlock_bh(&cmd->istate_lock); - if (!iscsit_logout_post_handler(cmd, conn)) - goto restart; - spin_lock_bh(&cmd->istate_lock); - use_misc = 0; - sent_status = 1; - break; - default: - pr_err("Unknown Opcode: 0x%02x ITT:" - " 0x%08x, i_state: %d on CID: %hu\n", - cmd->iscsi_opcode, cmd->init_task_tag, - cmd->i_state, conn->cid); - spin_unlock_bh(&cmd->istate_lock); - goto transport_err; - } - - if (sent_status) { - cmd->i_state = ISTATE_SENT_STATUS; - sent_status = 0; - } - spin_unlock_bh(&cmd->istate_lock); - - if (atomic_read(&conn->check_immediate_queue)) - break; - } + ret = handle_response_queue(conn); + if (ret == -EAGAIN) + goto restart; + else if (ret < 0) + goto transport_err; } transport_err: diff --git a/drivers/target/iscsi/iscsi_target.h b/drivers/target/iscsi/iscsi_target.h index 5db2ddeed5eb..7934cdc91356 100644 --- a/drivers/target/iscsi/iscsi_target.h +++ b/drivers/target/iscsi/iscsi_target.h @@ -18,7 +18,6 @@ extern int iscsit_logout_closesession(struct iscsi_cmd *, struct iscsi_conn *); extern int iscsit_logout_closeconnection(struct iscsi_cmd *, struct iscsi_conn *); extern int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *, struct iscsi_conn *); extern int iscsit_send_async_msg(struct iscsi_conn *, u16, u8, u8); -extern int iscsit_send_r2t(struct iscsi_cmd *, struct iscsi_conn *); extern int iscsit_build_r2ts_for_cmd(struct iscsi_cmd *, struct iscsi_conn *, int); extern void iscsit_thread_get_cpumask(struct iscsi_conn *); extern int iscsi_target_tx_thread(void *);