From b02efbfc9a051b41e71fe8f94ddf967260e024a6 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Tue, 2 Dec 2014 16:57:29 +0200 Subject: [PATCH] iser-target: Fix implicit termination of connections In situations such as bond failover, The new session establishment implicitly invokes the termination of the old connection. So, we don't want to wait for the old connection wait_conn to completely terminate before we accept the new connection and post a login response. The solution is to deffer the comp_wait completion and the conn_put to a work so wait_conn will effectively be non-blocking (flush errors are assumed to come very fast). We allocate isert_release_wq with WQ_UNBOUND and WQ_UNBOUND_MAX_ACTIVE to spread the concurrency of release works. Reported-by: Slava Shwartsman Signed-off-by: Sagi Grimberg Cc: # v3.10+ Signed-off-by: Nicholas Bellinger --- drivers/infiniband/ulp/isert/ib_isert.c | 42 ++++++++++++++++++++----- drivers/infiniband/ulp/isert/ib_isert.h | 1 + 2 files changed, 35 insertions(+), 8 deletions(-) diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c index f4b14ede18e4..33b549e752c1 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.c +++ b/drivers/infiniband/ulp/isert/ib_isert.c @@ -41,6 +41,7 @@ static DEFINE_MUTEX(device_list_mutex); static LIST_HEAD(device_list); static struct workqueue_struct *isert_rx_wq; static struct workqueue_struct *isert_comp_wq; +static struct workqueue_struct *isert_release_wq; static void isert_unmap_cmd(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn); @@ -3326,6 +3327,24 @@ isert_free_np(struct iscsi_np *np) kfree(isert_np); } +static void isert_release_work(struct work_struct *work) +{ + struct isert_conn *isert_conn = container_of(work, + struct isert_conn, + release_work); + + pr_info("Starting release conn %p\n", isert_conn); + + wait_for_completion(&isert_conn->conn_wait); + + mutex_lock(&isert_conn->conn_mutex); + isert_conn->state = ISER_CONN_DOWN; + mutex_unlock(&isert_conn->conn_mutex); + + pr_info("Destroying conn %p\n", isert_conn); + isert_put_conn(isert_conn); +} + static void isert_wait_conn(struct iscsi_conn *conn) { struct isert_conn *isert_conn = conn->context; @@ -3345,14 +3364,9 @@ static void isert_wait_conn(struct iscsi_conn *conn) mutex_unlock(&isert_conn->conn_mutex); wait_for_completion(&isert_conn->conn_wait_comp_err); - wait_for_completion(&isert_conn->conn_wait); - - mutex_lock(&isert_conn->conn_mutex); - isert_conn->state = ISER_CONN_DOWN; - mutex_unlock(&isert_conn->conn_mutex); - pr_info("Destroying conn %p\n", isert_conn); - isert_put_conn(isert_conn); + INIT_WORK(&isert_conn->release_work, isert_release_work); + queue_work(isert_release_wq, &isert_conn->release_work); } static void isert_free_conn(struct iscsi_conn *conn) @@ -3400,10 +3414,21 @@ static int __init isert_init(void) goto destroy_rx_wq; } + isert_release_wq = alloc_workqueue("isert_release_wq", WQ_UNBOUND, + WQ_UNBOUND_MAX_ACTIVE); + if (!isert_release_wq) { + pr_err("Unable to allocate isert_release_wq\n"); + ret = -ENOMEM; + goto destroy_comp_wq; + } + iscsit_register_transport(&iser_target_transport); - pr_debug("iSER_TARGET[0] - Loaded iser_target_transport\n"); + pr_info("iSER_TARGET[0] - Loaded iser_target_transport\n"); + return 0; +destroy_comp_wq: + destroy_workqueue(isert_comp_wq); destroy_rx_wq: destroy_workqueue(isert_rx_wq); return ret; @@ -3412,6 +3437,7 @@ destroy_rx_wq: static void __exit isert_exit(void) { flush_scheduled_work(); + destroy_workqueue(isert_release_wq); destroy_workqueue(isert_comp_wq); destroy_workqueue(isert_rx_wq); iscsit_unregister_transport(&iser_target_transport); diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h index 5cad43d3de44..9372d4d4d14a 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.h +++ b/drivers/infiniband/ulp/isert/ib_isert.h @@ -149,6 +149,7 @@ struct isert_conn { int conn_fr_pool_size; /* lock to protect fastreg pool */ spinlock_t conn_lock; + struct work_struct release_work; #define ISERT_COMP_BATCH_COUNT 8 int conn_comp_batch; struct llist_head conn_comp_llist; -- 2.20.1