From 03e7848a64ed535a30f5d7fc6dede2d5a6a2534b Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 30 Mar 2014 15:50:03 -0700 Subject: [PATCH] iser-target: Add missing se_cmd put for WRITE_PENDING in tx_comp_err This patch fixes a bug where outstanding RDMA_READs with WRITE_PENDING status require an extra target_put_sess_cmd() in isert_put_cmd() code when called from isert_cq_tx_comp_err() + isert_cq_drain_comp_llist() context during session shutdown. The extra kref PUT is required so that transport_generic_free_cmd() invokes the last target_put_sess_cmd() -> target_release_cmd_kref(), which will complete(&se_cmd->cmd_wait_comp) the outstanding se_cmd descriptor with WRITE_PENDING status, and awake the completion in target_wait_for_sess_cmds() to invoke TFO->release_cmd(). The bug was manifesting itself in target_wait_for_sess_cmds() where a se_cmd descriptor with WRITE_PENDING status would end up sleeping indefinately. Acked-by: Sagi Grimberg Cc: Or Gerlitz Cc: #3.10+ Signed-off-by: Nicholas Bellinger --- drivers/infiniband/ulp/isert/ib_isert.c | 37 +++++++++++++++++-------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c index 18ada7fb0fc9..f7801aeb7628 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.c +++ b/drivers/infiniband/ulp/isert/ib_isert.c @@ -1580,7 +1580,7 @@ isert_unreg_rdma(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn) } static void -isert_put_cmd(struct isert_cmd *isert_cmd) +isert_put_cmd(struct isert_cmd *isert_cmd, bool comp_err) { struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd; struct isert_conn *isert_conn = isert_cmd->conn; @@ -1596,8 +1596,21 @@ isert_put_cmd(struct isert_cmd *isert_cmd) list_del_init(&cmd->i_conn_node); spin_unlock_bh(&conn->cmd_lock); - if (cmd->data_direction == DMA_TO_DEVICE) + if (cmd->data_direction == DMA_TO_DEVICE) { iscsit_stop_dataout_timer(cmd); + /* + * Check for special case during comp_err where + * WRITE_PENDING has been handed off from core, + * but requires an extra target_put_sess_cmd() + * before transport_generic_free_cmd() below. + */ + if (comp_err && + cmd->se_cmd.t_state == TRANSPORT_WRITE_PENDING) { + struct se_cmd *se_cmd = &cmd->se_cmd; + + target_put_sess_cmd(se_cmd->se_sess, se_cmd); + } + } device->unreg_rdma_mem(isert_cmd, isert_conn); transport_generic_free_cmd(&cmd->se_cmd, 0); @@ -1652,7 +1665,7 @@ isert_unmap_tx_desc(struct iser_tx_desc *tx_desc, struct ib_device *ib_dev) static void isert_completion_put(struct iser_tx_desc *tx_desc, struct isert_cmd *isert_cmd, - struct ib_device *ib_dev) + struct ib_device *ib_dev, bool comp_err) { if (isert_cmd->pdu_buf_dma != 0) { pr_debug("Calling ib_dma_unmap_single for isert_cmd->pdu_buf_dma\n"); @@ -1662,7 +1675,7 @@ isert_completion_put(struct iser_tx_desc *tx_desc, struct isert_cmd *isert_cmd, } isert_unmap_tx_desc(tx_desc, ib_dev); - isert_put_cmd(isert_cmd); + isert_put_cmd(isert_cmd, comp_err); } static int @@ -1787,14 +1800,14 @@ isert_do_control_comp(struct work_struct *work) iscsit_tmr_post_handler(cmd, cmd->conn); cmd->i_state = ISTATE_SENT_STATUS; - isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev); + isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev, false); break; case ISTATE_SEND_REJECT: pr_debug("Got isert_do_control_comp ISTATE_SEND_REJECT: >>>\n"); atomic_dec(&isert_conn->post_send_buf_count); cmd->i_state = ISTATE_SENT_STATUS; - isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev); + isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev, false); break; case ISTATE_SEND_LOGOUTRSP: pr_debug("Calling iscsit_logout_post_handler >>>>>>>>>>>>>>\n"); @@ -1808,7 +1821,7 @@ isert_do_control_comp(struct work_struct *work) case ISTATE_SEND_TEXTRSP: atomic_dec(&isert_conn->post_send_buf_count); cmd->i_state = ISTATE_SENT_STATUS; - isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev); + isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev, false); break; default: pr_err("Unknown do_control_comp i_state %d\n", cmd->i_state); @@ -1850,7 +1863,7 @@ isert_response_completion(struct iser_tx_desc *tx_desc, atomic_dec(&isert_conn->post_send_buf_count); cmd->i_state = ISTATE_SENT_STATUS; - isert_completion_put(tx_desc, isert_cmd, ib_dev); + isert_completion_put(tx_desc, isert_cmd, ib_dev, false); } static void @@ -1943,7 +1956,8 @@ isert_cq_drain_comp_llist(struct isert_conn *isert_conn, struct ib_device *ib_de &isert_conn->post_send_buf_count); else atomic_dec(&isert_conn->post_send_buf_count); - isert_completion_put(t, t->isert_cmd, ib_dev); + + isert_completion_put(t, t->isert_cmd, ib_dev, true); } } @@ -1973,14 +1987,15 @@ isert_cq_tx_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn &isert_conn->post_send_buf_count); else atomic_dec(&isert_conn->post_send_buf_count); - isert_completion_put(t, t->isert_cmd, ib_dev); + + isert_completion_put(t, t->isert_cmd, ib_dev, true); } tx_desc->comp_llnode_batch = NULL; if (!isert_cmd) isert_unmap_tx_desc(tx_desc, ib_dev); else - isert_completion_put(tx_desc, isert_cmd, ib_dev); + isert_completion_put(tx_desc, isert_cmd, ib_dev, true); } static void