[PATCH 3.12 099/123] iscsi-target: Convert iscsi_thread_set usage to kthread.h
From: Jiri Slaby
Date: Tue Aug 04 2015 - 10:50:15 EST
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 88dcd2dab5c23b1c9cfc396246d8f476c872f0ca upstream.
This patch converts iscsi-target code to use modern kthread.h API
callers for creating RX/TX threads for each new iscsi_conn descriptor,
and releasing associated RX/TX threads during connection shutdown.
This is done using iscsit_start_kthreads() -> kthread_run() to start
new kthreads from within iscsi_post_login_handler(), and invoking
kthread_stop() from existing iscsit_close_connection() code.
Also, convert iscsit_logout_post_handler_closesession() code to use
cmpxchg when determing when iscsit_cause_connection_reinstatement()
needs to sleep waiting for completion.
Reported-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Tested-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: Slava Shwartsman <valyushash@xxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/target/iscsi/iscsi_target.c | 104 +++++++++++++-----------------
drivers/target/iscsi/iscsi_target_core.h | 7 ++
drivers/target/iscsi/iscsi_target_erl0.c | 13 ++--
drivers/target/iscsi/iscsi_target_login.c | 59 +++++++++++++++--
4 files changed, 114 insertions(+), 69 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index a16a6ff73db9..8ac1800eef06 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -518,7 +518,7 @@ static struct iscsit_transport iscsi_target_transport = {
static int __init iscsi_target_init_module(void)
{
- int ret = 0;
+ int ret = 0, size;
pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
@@ -527,6 +527,7 @@ static int __init iscsi_target_init_module(void)
pr_err("Unable to allocate memory for iscsit_global\n");
return -1;
}
+ spin_lock_init(&iscsit_global->ts_bitmap_lock);
mutex_init(&auth_id_lock);
spin_lock_init(&sess_idr_lock);
idr_init(&tiqn_idr);
@@ -536,15 +537,11 @@ static int __init iscsi_target_init_module(void)
if (ret < 0)
goto out;
- ret = iscsi_thread_set_init();
- if (ret < 0)
+ size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
+ iscsit_global->ts_bitmap = vzalloc(size);
+ if (!iscsit_global->ts_bitmap) {
+ pr_err("Unable to allocate iscsit_global->ts_bitmap\n");
goto configfs_out;
-
- if (iscsi_allocate_thread_sets(TARGET_THREAD_SET_COUNT) !=
- TARGET_THREAD_SET_COUNT) {
- pr_err("iscsi_allocate_thread_sets() returned"
- " unexpected value!\n");
- goto ts_out1;
}
lio_qr_cache = kmem_cache_create("lio_qr_cache",
@@ -553,7 +550,7 @@ static int __init iscsi_target_init_module(void)
if (!lio_qr_cache) {
pr_err("nable to kmem_cache_create() for"
" lio_qr_cache\n");
- goto ts_out2;
+ goto bitmap_out;
}
lio_dr_cache = kmem_cache_create("lio_dr_cache",
@@ -597,10 +594,8 @@ dr_out:
kmem_cache_destroy(lio_dr_cache);
qr_out:
kmem_cache_destroy(lio_qr_cache);
-ts_out2:
- iscsi_deallocate_thread_sets();
-ts_out1:
- iscsi_thread_set_free();
+bitmap_out:
+ vfree(iscsit_global->ts_bitmap);
configfs_out:
iscsi_target_deregister_configfs();
out:
@@ -610,8 +605,6 @@ out:
static void __exit iscsi_target_cleanup_module(void)
{
- iscsi_deallocate_thread_sets();
- iscsi_thread_set_free();
iscsit_release_discovery_tpg();
iscsit_unregister_transport(&iscsi_target_transport);
kmem_cache_destroy(lio_qr_cache);
@@ -621,6 +614,7 @@ static void __exit iscsi_target_cleanup_module(void)
iscsi_target_deregister_configfs();
+ vfree(iscsit_global->ts_bitmap);
kfree(iscsit_global);
}
@@ -3649,17 +3643,16 @@ static int iscsit_send_reject(
void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
{
- struct iscsi_thread_set *ts = conn->thread_set;
int ord, cpu;
/*
- * thread_id is assigned from iscsit_global->ts_bitmap from
- * within iscsi_thread_set.c:iscsi_allocate_thread_sets()
+ * bitmap_id is assigned from iscsit_global->ts_bitmap from
+ * within iscsit_start_kthreads()
*
- * Here we use thread_id to determine which CPU that this
- * iSCSI connection's iscsi_thread_set will be scheduled to
+ * Here we use bitmap_id to determine which CPU that this
+ * iSCSI connection's RX/TX threads will be scheduled to
* execute upon.
*/
- ord = ts->thread_id % cpumask_weight(cpu_online_mask);
+ ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
for_each_online_cpu(cpu) {
if (ord-- == 0) {
cpumask_set_cpu(cpu, conn->conn_cpumask);
@@ -3851,7 +3844,7 @@ check_rsp_state:
switch (state) {
case ISTATE_SEND_LOGOUTRSP:
if (!iscsit_logout_post_handler(cmd, conn))
- goto restart;
+ return -ECONNRESET;
/* fall through */
case ISTATE_SEND_STATUS:
case ISTATE_SEND_ASYNCMSG:
@@ -3879,8 +3872,6 @@ check_rsp_state:
err:
return -1;
-restart:
- return -EAGAIN;
}
static int iscsit_handle_response_queue(struct iscsi_conn *conn)
@@ -3907,21 +3898,13 @@ static int iscsit_handle_response_queue(struct iscsi_conn *conn)
int iscsi_target_tx_thread(void *arg)
{
int ret = 0;
- struct iscsi_conn *conn;
- struct iscsi_thread_set *ts = arg;
+ struct iscsi_conn *conn = arg;
/*
* Allow ourselves to be interrupted by SIGINT so that a
* connection recovery / failure event can be triggered externally.
*/
allow_signal(SIGINT);
-restart:
- conn = iscsi_tx_thread_pre_handler(ts);
- if (!conn)
- goto out;
-
- ret = 0;
-
while (!kthread_should_stop()) {
/*
* Ensure that both TX and RX per connection kthreads
@@ -3930,11 +3913,9 @@ restart:
iscsit_thread_check_cpumask(conn, current, 1);
wait_event_interruptible(conn->queues_wq,
- !iscsit_conn_all_queues_empty(conn) ||
- ts->status == ISCSI_THREAD_SET_RESET);
+ !iscsit_conn_all_queues_empty(conn));
- if ((ts->status == ISCSI_THREAD_SET_RESET) ||
- signal_pending(current))
+ if (signal_pending(current))
goto transport_err;
get_immediate:
@@ -3945,15 +3926,14 @@ get_immediate:
ret = iscsit_handle_response_queue(conn);
if (ret == 1)
goto get_immediate;
- else if (ret == -EAGAIN)
- goto restart;
+ else if (ret == -ECONNRESET)
+ goto out;
else if (ret < 0)
goto transport_err;
}
transport_err:
iscsit_take_action_for_connection_exit(conn);
- goto restart;
out:
return 0;
}
@@ -4042,8 +4022,7 @@ int iscsi_target_rx_thread(void *arg)
int ret;
u8 buffer[ISCSI_HDR_LEN], opcode;
u32 checksum = 0, digest = 0;
- struct iscsi_conn *conn = NULL;
- struct iscsi_thread_set *ts = arg;
+ struct iscsi_conn *conn = arg;
struct kvec iov;
/*
* Allow ourselves to be interrupted by SIGINT so that a
@@ -4051,11 +4030,6 @@ int iscsi_target_rx_thread(void *arg)
*/
allow_signal(SIGINT);
-restart:
- conn = iscsi_rx_thread_pre_handler(ts);
- if (!conn)
- goto out;
-
if (conn->conn_transport->transport_type == ISCSI_INFINIBAND) {
struct completion comp;
int rc;
@@ -4065,7 +4039,7 @@ restart:
if (rc < 0)
goto transport_err;
- goto out;
+ goto transport_err;
}
while (!kthread_should_stop()) {
@@ -4143,8 +4117,6 @@ transport_err:
if (!signal_pending(current))
atomic_set(&conn->transport_failed, 1);
iscsit_take_action_for_connection_exit(conn);
- goto restart;
-out:
return 0;
}
@@ -4206,7 +4178,24 @@ int iscsit_close_connection(
if (conn->conn_transport->transport_type == ISCSI_TCP)
complete(&conn->conn_logout_comp);
- iscsi_release_thread_set(conn);
+ if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
+ if (conn->tx_thread &&
+ cmpxchg(&conn->tx_thread_active, true, false)) {
+ send_sig(SIGINT, conn->tx_thread, 1);
+ kthread_stop(conn->tx_thread);
+ }
+ } else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
+ if (conn->rx_thread &&
+ cmpxchg(&conn->rx_thread_active, true, false)) {
+ send_sig(SIGINT, conn->rx_thread, 1);
+ kthread_stop(conn->rx_thread);
+ }
+ }
+
+ spin_lock(&iscsit_global->ts_bitmap_lock);
+ bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
+ get_order(1));
+ spin_unlock(&iscsit_global->ts_bitmap_lock);
iscsit_stop_timers_for_cmds(conn);
iscsit_stop_nopin_response_timer(conn);
@@ -4485,15 +4474,13 @@ static void iscsit_logout_post_handler_closesession(
struct iscsi_conn *conn)
{
struct iscsi_session *sess = conn->sess;
-
- iscsi_set_thread_clear(conn, ISCSI_CLEAR_TX_THREAD);
- iscsi_set_thread_set_signal(conn, ISCSI_SIGNAL_TX_THREAD);
+ int sleep = cmpxchg(&conn->tx_thread_active, true, false);
atomic_set(&conn->conn_logout_remove, 0);
complete(&conn->conn_logout_comp);
iscsit_dec_conn_usage_count(conn);
- iscsit_stop_session(sess, 1, 1);
+ iscsit_stop_session(sess, sleep, sleep);
iscsit_dec_session_usage_count(sess);
target_put_session(sess->se_sess);
}
@@ -4501,13 +4488,12 @@ static void iscsit_logout_post_handler_closesession(
static void iscsit_logout_post_handler_samecid(
struct iscsi_conn *conn)
{
- iscsi_set_thread_clear(conn, ISCSI_CLEAR_TX_THREAD);
- iscsi_set_thread_set_signal(conn, ISCSI_SIGNAL_TX_THREAD);
+ int sleep = cmpxchg(&conn->tx_thread_active, true, false);
atomic_set(&conn->conn_logout_remove, 0);
complete(&conn->conn_logout_comp);
- iscsit_cause_connection_reinstatement(conn, 1);
+ iscsit_cause_connection_reinstatement(conn, sleep);
iscsit_dec_conn_usage_count(conn);
}
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index e2e1e63237d9..1c232c509dae 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -601,6 +601,11 @@ struct iscsi_conn {
struct iscsi_session *sess;
/* Pointer to thread_set in use for this conn's threads */
struct iscsi_thread_set *thread_set;
+ int bitmap_id;
+ int rx_thread_active;
+ struct task_struct *rx_thread;
+ int tx_thread_active;
+ struct task_struct *tx_thread;
/* list_head for session connection list */
struct list_head conn_list;
} ____cacheline_aligned;
@@ -881,10 +886,12 @@ struct iscsit_global {
/* Unique identifier used for the authentication daemon */
u32 auth_id;
u32 inactive_ts;
+#define ISCSIT_BITMAP_BITS 262144
/* Thread Set bitmap count */
int ts_bitmap_count;
/* Thread Set bitmap pointer */
unsigned long *ts_bitmap;
+ spinlock_t ts_bitmap_lock;
/* Used for iSCSI discovery session authentication */
struct iscsi_node_acl discovery_acl;
struct iscsi_portal_group *discovery_tpg;
diff --git a/drivers/target/iscsi/iscsi_target_erl0.c b/drivers/target/iscsi/iscsi_target_erl0.c
index 41052e512d92..27e34a7b212e 100644
--- a/drivers/target/iscsi/iscsi_target_erl0.c
+++ b/drivers/target/iscsi/iscsi_target_erl0.c
@@ -864,7 +864,10 @@ void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *conn)
}
spin_unlock_bh(&conn->state_lock);
- iscsi_thread_set_force_reinstatement(conn);
+ if (conn->tx_thread && conn->tx_thread_active)
+ send_sig(SIGINT, conn->tx_thread, 1);
+ if (conn->rx_thread && conn->rx_thread_active)
+ send_sig(SIGINT, conn->rx_thread, 1);
sleep:
wait_for_completion(&conn->conn_wait_rcfr_comp);
@@ -889,10 +892,10 @@ void iscsit_cause_connection_reinstatement(struct iscsi_conn *conn, int sleep)
return;
}
- if (iscsi_thread_set_force_reinstatement(conn) < 0) {
- spin_unlock_bh(&conn->state_lock);
- return;
- }
+ if (conn->tx_thread && conn->tx_thread_active)
+ send_sig(SIGINT, conn->tx_thread, 1);
+ if (conn->rx_thread && conn->rx_thread_active)
+ send_sig(SIGINT, conn->rx_thread, 1);
atomic_set(&conn->connection_reinstatement, 1);
if (!sleep) {
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index eb92af05ee12..9d5762011413 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -682,6 +682,51 @@ static void iscsi_post_login_start_timers(struct iscsi_conn *conn)
iscsit_start_nopin_timer(conn);
}
+int iscsit_start_kthreads(struct iscsi_conn *conn)
+{
+ int ret = 0;
+
+ spin_lock(&iscsit_global->ts_bitmap_lock);
+ conn->bitmap_id = bitmap_find_free_region(iscsit_global->ts_bitmap,
+ ISCSIT_BITMAP_BITS, get_order(1));
+ spin_unlock(&iscsit_global->ts_bitmap_lock);
+
+ if (conn->bitmap_id < 0) {
+ pr_err("bitmap_find_free_region() failed for"
+ " iscsit_start_kthreads()\n");
+ return -ENOMEM;
+ }
+
+ conn->tx_thread = kthread_run(iscsi_target_tx_thread, conn,
+ "%s", ISCSI_TX_THREAD_NAME);
+ if (IS_ERR(conn->tx_thread)) {
+ pr_err("Unable to start iscsi_target_tx_thread\n");
+ ret = PTR_ERR(conn->tx_thread);
+ goto out_bitmap;
+ }
+ conn->tx_thread_active = true;
+
+ conn->rx_thread = kthread_run(iscsi_target_rx_thread, conn,
+ "%s", ISCSI_RX_THREAD_NAME);
+ if (IS_ERR(conn->rx_thread)) {
+ pr_err("Unable to start iscsi_target_rx_thread\n");
+ ret = PTR_ERR(conn->rx_thread);
+ goto out_tx;
+ }
+ conn->rx_thread_active = true;
+
+ return 0;
+out_tx:
+ kthread_stop(conn->tx_thread);
+ conn->tx_thread_active = false;
+out_bitmap:
+ spin_lock(&iscsit_global->ts_bitmap_lock);
+ bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
+ get_order(1));
+ spin_unlock(&iscsit_global->ts_bitmap_lock);
+ return ret;
+}
+
int iscsi_post_login_handler(
struct iscsi_np *np,
struct iscsi_conn *conn,
@@ -692,7 +737,7 @@ int iscsi_post_login_handler(
struct se_session *se_sess = sess->se_sess;
struct iscsi_portal_group *tpg = ISCSI_TPG_S(sess);
struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
- struct iscsi_thread_set *ts;
+ int rc;
iscsit_inc_conn_usage_count(conn);
@@ -707,7 +752,6 @@ int iscsi_post_login_handler(
/*
* SCSI Initiator -> SCSI Target Port Mapping
*/
- ts = iscsi_get_thread_set();
if (!zero_tsih) {
iscsi_set_session_parameters(sess->sess_ops,
conn->param_list, 0);
@@ -734,9 +778,11 @@ int iscsi_post_login_handler(
sess->sess_ops->InitiatorName);
spin_unlock_bh(&sess->conn_lock);
- iscsi_post_login_start_timers(conn);
+ rc = iscsit_start_kthreads(conn);
+ if (rc)
+ return rc;
- iscsi_activate_thread_set(conn, ts);
+ iscsi_post_login_start_timers(conn);
/*
* Determine CPU mask to ensure connection's RX and TX kthreads
* are scheduled on the same CPU.
@@ -793,8 +839,11 @@ int iscsi_post_login_handler(
" iSCSI Target Portal Group: %hu\n", tpg->nsessions, tpg->tpgt);
spin_unlock_bh(&se_tpg->session_lock);
+ rc = iscsit_start_kthreads(conn);
+ if (rc)
+ return rc;
+
iscsi_post_login_start_timers(conn);
- iscsi_activate_thread_set(conn, ts);
/*
* Determine CPU mask to ensure connection's RX and TX kthreads
* are scheduled on the same CPU.
--
2.5.0
--
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