Commit 073900bd authored by Nicholas Bellinger's avatar Nicholas Bellinger

iscsi-target: Drop legacy iscsi_target_tq.c logic

Now that iscsi_conn allocates new [rx,tx] threads using kthread.h
primitives on the fly, and kthread_stop() is called directly during
connection shutdown, it's time to go ahead and drop iscsi_target_tq.c
legacy code.

The use of multiple struct completion in iscsi_activate_thread_set()
has been proven to cause issues during repeated iser login/logout.
Tested-by: default avatarSagi Grimberg <sagig@mellanox.com>
Cc: Slava Shwartsman <valyushash@gmail.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 88dcd2da
iscsi_target_mod-y += iscsi_target_parameters.o \
iscsi_target_seq_pdu_list.o \
iscsi_target_tq.o \
iscsi_target_auth.o \
iscsi_target_datain_values.o \
iscsi_target_device.o \
......
......@@ -33,7 +33,6 @@
#include <target/iscsi/iscsi_target_core.h>
#include "iscsi_target_parameters.h"
#include "iscsi_target_seq_pdu_list.h"
#include "iscsi_target_tq.h"
#include "iscsi_target_configfs.h"
#include "iscsi_target_datain_values.h"
#include "iscsi_target_erl0.h"
......@@ -4360,8 +4359,6 @@ int iscsit_close_connection(
iscsit_put_transport(conn->conn_transport);
conn->thread_set = NULL;
pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
conn->conn_state = TARG_CONN_STATE_FREE;
kfree(conn);
......
......@@ -24,7 +24,6 @@
#include <target/iscsi/iscsi_target_core.h>
#include <target/iscsi/iscsi_transport.h>
#include "iscsi_target_seq_pdu_list.h"
#include "iscsi_target_tq.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl1.h"
#include "iscsi_target_erl2.h"
......
......@@ -26,7 +26,6 @@
#include <target/iscsi/iscsi_target_core.h>
#include <target/iscsi/iscsi_target_stat.h>
#include "iscsi_target_tq.h"
#include "iscsi_target_device.h"
#include "iscsi_target_nego.h"
#include "iscsi_target_erl0.h"
......
/*******************************************************************************
* This file contains the iSCSI Login Thread and Thread Queue functions.
*
* (c) Copyright 2007-2013 Datera, Inc.
*
* Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
******************************************************************************/
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/bitmap.h>
#include <target/iscsi/iscsi_target_core.h>
#include "iscsi_target_tq.h"
#include "iscsi_target.h"
static LIST_HEAD(inactive_ts_list);
static DEFINE_SPINLOCK(inactive_ts_lock);
static DEFINE_SPINLOCK(ts_bitmap_lock);
static void iscsi_add_ts_to_inactive_list(struct iscsi_thread_set *ts)
{
if (!list_empty(&ts->ts_list)) {
WARN_ON(1);
return;
}
spin_lock(&inactive_ts_lock);
list_add_tail(&ts->ts_list, &inactive_ts_list);
iscsit_global->inactive_ts++;
spin_unlock(&inactive_ts_lock);
}
static struct iscsi_thread_set *iscsi_get_ts_from_inactive_list(void)
{
struct iscsi_thread_set *ts;
spin_lock(&inactive_ts_lock);
if (list_empty(&inactive_ts_list)) {
spin_unlock(&inactive_ts_lock);
return NULL;
}
ts = list_first_entry(&inactive_ts_list, struct iscsi_thread_set, ts_list);
list_del_init(&ts->ts_list);
iscsit_global->inactive_ts--;
spin_unlock(&inactive_ts_lock);
return ts;
}
int iscsi_allocate_thread_sets(u32 thread_pair_count)
{
int allocated_thread_pair_count = 0, i, thread_id;
struct iscsi_thread_set *ts = NULL;
for (i = 0; i < thread_pair_count; i++) {
ts = kzalloc(sizeof(struct iscsi_thread_set), GFP_KERNEL);
if (!ts) {
pr_err("Unable to allocate memory for"
" thread set.\n");
return allocated_thread_pair_count;
}
/*
* Locate the next available regision in the thread_set_bitmap
*/
spin_lock(&ts_bitmap_lock);
thread_id = bitmap_find_free_region(iscsit_global->ts_bitmap,
iscsit_global->ts_bitmap_count, get_order(1));
spin_unlock(&ts_bitmap_lock);
if (thread_id < 0) {
pr_err("bitmap_find_free_region() failed for"
" thread_set_bitmap\n");
kfree(ts);
return allocated_thread_pair_count;
}
ts->thread_id = thread_id;
ts->status = ISCSI_THREAD_SET_FREE;
INIT_LIST_HEAD(&ts->ts_list);
spin_lock_init(&ts->ts_state_lock);
init_completion(&ts->rx_restart_comp);
init_completion(&ts->tx_restart_comp);
init_completion(&ts->rx_start_comp);
init_completion(&ts->tx_start_comp);
sema_init(&ts->ts_activate_sem, 0);
ts->create_threads = 1;
ts->tx_thread = kthread_run(iscsi_target_tx_thread, ts, "%s",
ISCSI_TX_THREAD_NAME);
if (IS_ERR(ts->tx_thread)) {
dump_stack();
pr_err("Unable to start iscsi_target_tx_thread\n");
break;
}
ts->rx_thread = kthread_run(iscsi_target_rx_thread, ts, "%s",
ISCSI_RX_THREAD_NAME);
if (IS_ERR(ts->rx_thread)) {
kthread_stop(ts->tx_thread);
pr_err("Unable to start iscsi_target_rx_thread\n");
break;
}
ts->create_threads = 0;
iscsi_add_ts_to_inactive_list(ts);
allocated_thread_pair_count++;
}
pr_debug("Spawned %d thread set(s) (%d total threads).\n",
allocated_thread_pair_count, allocated_thread_pair_count * 2);
return allocated_thread_pair_count;
}
static void iscsi_deallocate_thread_one(struct iscsi_thread_set *ts)
{
spin_lock_bh(&ts->ts_state_lock);
ts->status = ISCSI_THREAD_SET_DIE;
if (ts->rx_thread) {
complete(&ts->rx_start_comp);
spin_unlock_bh(&ts->ts_state_lock);
kthread_stop(ts->rx_thread);
spin_lock_bh(&ts->ts_state_lock);
}
if (ts->tx_thread) {
complete(&ts->tx_start_comp);
spin_unlock_bh(&ts->ts_state_lock);
kthread_stop(ts->tx_thread);
spin_lock_bh(&ts->ts_state_lock);
}
spin_unlock_bh(&ts->ts_state_lock);
/*
* Release this thread_id in the thread_set_bitmap
*/
spin_lock(&ts_bitmap_lock);
bitmap_release_region(iscsit_global->ts_bitmap,
ts->thread_id, get_order(1));
spin_unlock(&ts_bitmap_lock);
kfree(ts);
}
void iscsi_deallocate_thread_sets(void)
{
struct iscsi_thread_set *ts = NULL;
u32 released_count = 0;
while ((ts = iscsi_get_ts_from_inactive_list())) {
iscsi_deallocate_thread_one(ts);
released_count++;
}
if (released_count)
pr_debug("Stopped %d thread set(s) (%d total threads)."
"\n", released_count, released_count * 2);
}
static void iscsi_deallocate_extra_thread_sets(void)
{
u32 orig_count, released_count = 0;
struct iscsi_thread_set *ts = NULL;
orig_count = TARGET_THREAD_SET_COUNT;
while ((iscsit_global->inactive_ts + 1) > orig_count) {
ts = iscsi_get_ts_from_inactive_list();
if (!ts)
break;
iscsi_deallocate_thread_one(ts);
released_count++;
}
if (released_count)
pr_debug("Stopped %d thread set(s) (%d total threads)."
"\n", released_count, released_count * 2);
}
void iscsi_activate_thread_set(struct iscsi_conn *conn, struct iscsi_thread_set *ts)
{
spin_lock_bh(&ts->ts_state_lock);
conn->thread_set = ts;
ts->conn = conn;
ts->status = ISCSI_THREAD_SET_ACTIVE;
spin_unlock_bh(&ts->ts_state_lock);
complete(&ts->rx_start_comp);
complete(&ts->tx_start_comp);
down(&ts->ts_activate_sem);
}
struct iscsi_thread_set *iscsi_get_thread_set(void)
{
struct iscsi_thread_set *ts;
get_set:
ts = iscsi_get_ts_from_inactive_list();
if (!ts) {
iscsi_allocate_thread_sets(1);
goto get_set;
}
ts->delay_inactive = 1;
ts->signal_sent = 0;
ts->thread_count = 2;
init_completion(&ts->rx_restart_comp);
init_completion(&ts->tx_restart_comp);
sema_init(&ts->ts_activate_sem, 0);
return ts;
}
void iscsi_set_thread_clear(struct iscsi_conn *conn, u8 thread_clear)
{
struct iscsi_thread_set *ts = NULL;
if (!conn->thread_set) {
pr_err("struct iscsi_conn->thread_set is NULL\n");
return;
}
ts = conn->thread_set;
spin_lock_bh(&ts->ts_state_lock);
ts->thread_clear &= ~thread_clear;
if ((thread_clear & ISCSI_CLEAR_RX_THREAD) &&
(ts->blocked_threads & ISCSI_BLOCK_RX_THREAD))
complete(&ts->rx_restart_comp);
else if ((thread_clear & ISCSI_CLEAR_TX_THREAD) &&
(ts->blocked_threads & ISCSI_BLOCK_TX_THREAD))
complete(&ts->tx_restart_comp);
spin_unlock_bh(&ts->ts_state_lock);
}
void iscsi_set_thread_set_signal(struct iscsi_conn *conn, u8 signal_sent)
{
struct iscsi_thread_set *ts = NULL;
if (!conn->thread_set) {
pr_err("struct iscsi_conn->thread_set is NULL\n");
return;
}
ts = conn->thread_set;
spin_lock_bh(&ts->ts_state_lock);
ts->signal_sent |= signal_sent;
spin_unlock_bh(&ts->ts_state_lock);
}
int iscsi_release_thread_set(struct iscsi_conn *conn)
{
int thread_called = 0;
struct iscsi_thread_set *ts = NULL;
if (!conn || !conn->thread_set) {
pr_err("connection or thread set pointer is NULL\n");
BUG();
}
ts = conn->thread_set;
spin_lock_bh(&ts->ts_state_lock);
ts->status = ISCSI_THREAD_SET_RESET;
if (!strncmp(current->comm, ISCSI_RX_THREAD_NAME,
strlen(ISCSI_RX_THREAD_NAME)))
thread_called = ISCSI_RX_THREAD;
else if (!strncmp(current->comm, ISCSI_TX_THREAD_NAME,
strlen(ISCSI_TX_THREAD_NAME)))
thread_called = ISCSI_TX_THREAD;
if (ts->rx_thread && (thread_called == ISCSI_TX_THREAD) &&
(ts->thread_clear & ISCSI_CLEAR_RX_THREAD)) {
if (!(ts->signal_sent & ISCSI_SIGNAL_RX_THREAD)) {
send_sig(SIGINT, ts->rx_thread, 1);
ts->signal_sent |= ISCSI_SIGNAL_RX_THREAD;
}
ts->blocked_threads |= ISCSI_BLOCK_RX_THREAD;
spin_unlock_bh(&ts->ts_state_lock);
wait_for_completion(&ts->rx_restart_comp);
spin_lock_bh(&ts->ts_state_lock);
ts->blocked_threads &= ~ISCSI_BLOCK_RX_THREAD;
}
if (ts->tx_thread && (thread_called == ISCSI_RX_THREAD) &&
(ts->thread_clear & ISCSI_CLEAR_TX_THREAD)) {
if (!(ts->signal_sent & ISCSI_SIGNAL_TX_THREAD)) {
send_sig(SIGINT, ts->tx_thread, 1);
ts->signal_sent |= ISCSI_SIGNAL_TX_THREAD;
}
ts->blocked_threads |= ISCSI_BLOCK_TX_THREAD;
spin_unlock_bh(&ts->ts_state_lock);
wait_for_completion(&ts->tx_restart_comp);
spin_lock_bh(&ts->ts_state_lock);
ts->blocked_threads &= ~ISCSI_BLOCK_TX_THREAD;
}
ts->conn = NULL;
ts->status = ISCSI_THREAD_SET_FREE;
spin_unlock_bh(&ts->ts_state_lock);
return 0;
}
int iscsi_thread_set_force_reinstatement(struct iscsi_conn *conn)
{
struct iscsi_thread_set *ts;
if (!conn->thread_set)
return -1;
ts = conn->thread_set;
spin_lock_bh(&ts->ts_state_lock);
if (ts->status != ISCSI_THREAD_SET_ACTIVE) {
spin_unlock_bh(&ts->ts_state_lock);
return -1;
}
if (ts->tx_thread && (!(ts->signal_sent & ISCSI_SIGNAL_TX_THREAD))) {
send_sig(SIGINT, ts->tx_thread, 1);
ts->signal_sent |= ISCSI_SIGNAL_TX_THREAD;
}
if (ts->rx_thread && (!(ts->signal_sent & ISCSI_SIGNAL_RX_THREAD))) {
send_sig(SIGINT, ts->rx_thread, 1);
ts->signal_sent |= ISCSI_SIGNAL_RX_THREAD;
}
spin_unlock_bh(&ts->ts_state_lock);
return 0;
}
static void iscsi_check_to_add_additional_sets(void)
{
int thread_sets_add;
spin_lock(&inactive_ts_lock);
thread_sets_add = iscsit_global->inactive_ts;
spin_unlock(&inactive_ts_lock);
if (thread_sets_add == 1)
iscsi_allocate_thread_sets(1);
}
static int iscsi_signal_thread_pre_handler(struct iscsi_thread_set *ts)
{
spin_lock_bh(&ts->ts_state_lock);
if (ts->status == ISCSI_THREAD_SET_DIE || kthread_should_stop() ||
signal_pending(current)) {
spin_unlock_bh(&ts->ts_state_lock);
return -1;
}
spin_unlock_bh(&ts->ts_state_lock);
return 0;
}
struct iscsi_conn *iscsi_rx_thread_pre_handler(struct iscsi_thread_set *ts)
{
int ret;
spin_lock_bh(&ts->ts_state_lock);
if (ts->create_threads) {
spin_unlock_bh(&ts->ts_state_lock);
goto sleep;
}
if (ts->status != ISCSI_THREAD_SET_DIE)
flush_signals(current);
if (ts->delay_inactive && (--ts->thread_count == 0)) {
spin_unlock_bh(&ts->ts_state_lock);
if (!iscsit_global->in_shutdown)
iscsi_deallocate_extra_thread_sets();
iscsi_add_ts_to_inactive_list(ts);
spin_lock_bh(&ts->ts_state_lock);
}
if ((ts->status == ISCSI_THREAD_SET_RESET) &&
(ts->thread_clear & ISCSI_CLEAR_RX_THREAD))
complete(&ts->rx_restart_comp);
ts->thread_clear &= ~ISCSI_CLEAR_RX_THREAD;
spin_unlock_bh(&ts->ts_state_lock);
sleep:
ret = wait_for_completion_interruptible(&ts->rx_start_comp);
if (ret != 0)
return NULL;
if (iscsi_signal_thread_pre_handler(ts) < 0)
return NULL;
iscsi_check_to_add_additional_sets();
spin_lock_bh(&ts->ts_state_lock);
if (!ts->conn) {
pr_err("struct iscsi_thread_set->conn is NULL for"
" RX thread_id: %s/%d\n", current->comm, current->pid);
spin_unlock_bh(&ts->ts_state_lock);
return NULL;
}
ts->thread_clear |= ISCSI_CLEAR_RX_THREAD;
spin_unlock_bh(&ts->ts_state_lock);
up(&ts->ts_activate_sem);
return ts->conn;
}
struct iscsi_conn *iscsi_tx_thread_pre_handler(struct iscsi_thread_set *ts)
{
int ret;
spin_lock_bh(&ts->ts_state_lock);
if (ts->create_threads) {
spin_unlock_bh(&ts->ts_state_lock);
goto sleep;
}
if (ts->status != ISCSI_THREAD_SET_DIE)
flush_signals(current);
if (ts->delay_inactive && (--ts->thread_count == 0)) {
spin_unlock_bh(&ts->ts_state_lock);
if (!iscsit_global->in_shutdown)
iscsi_deallocate_extra_thread_sets();
iscsi_add_ts_to_inactive_list(ts);
spin_lock_bh(&ts->ts_state_lock);
}
if ((ts->status == ISCSI_THREAD_SET_RESET) &&
(ts->thread_clear & ISCSI_CLEAR_TX_THREAD))
complete(&ts->tx_restart_comp);
ts->thread_clear &= ~ISCSI_CLEAR_TX_THREAD;
spin_unlock_bh(&ts->ts_state_lock);
sleep:
ret = wait_for_completion_interruptible(&ts->tx_start_comp);
if (ret != 0)
return NULL;
if (iscsi_signal_thread_pre_handler(ts) < 0)
return NULL;
iscsi_check_to_add_additional_sets();
spin_lock_bh(&ts->ts_state_lock);
if (!ts->conn) {
pr_err("struct iscsi_thread_set->conn is NULL for"
" TX thread_id: %s/%d\n", current->comm, current->pid);
spin_unlock_bh(&ts->ts_state_lock);
return NULL;
}
ts->thread_clear |= ISCSI_CLEAR_TX_THREAD;
spin_unlock_bh(&ts->ts_state_lock);
up(&ts->ts_activate_sem);
return ts->conn;
}
int iscsi_thread_set_init(void)
{
int size;
iscsit_global->ts_bitmap_count = ISCSI_TS_BITMAP_BITS;
size = BITS_TO_LONGS(iscsit_global->ts_bitmap_count) * sizeof(long);
iscsit_global->ts_bitmap = kzalloc(size, GFP_KERNEL);
if (!iscsit_global->ts_bitmap) {
pr_err("Unable to allocate iscsit_global->ts_bitmap\n");
return -ENOMEM;
}
return 0;
}
void iscsi_thread_set_free(void)
{
kfree(iscsit_global->ts_bitmap);
}
#ifndef ISCSI_THREAD_QUEUE_H
#define ISCSI_THREAD_QUEUE_H
/*
* Defines for thread sets.
*/
extern int iscsi_thread_set_force_reinstatement(struct iscsi_conn *);
extern int iscsi_allocate_thread_sets(u32);
extern void iscsi_deallocate_thread_sets(void);
extern void iscsi_activate_thread_set(struct iscsi_conn *, struct iscsi_thread_set *);
extern struct iscsi_thread_set *iscsi_get_thread_set(void);
extern void iscsi_set_thread_clear(struct iscsi_conn *, u8);
extern void iscsi_set_thread_set_signal(struct iscsi_conn *, u8);
extern int iscsi_release_thread_set(struct iscsi_conn *);
extern struct iscsi_conn *iscsi_rx_thread_pre_handler(struct iscsi_thread_set *);
extern struct iscsi_conn *iscsi_tx_thread_pre_handler(struct iscsi_thread_set *);
extern int iscsi_thread_set_init(void);
extern void iscsi_thread_set_free(void);
extern int iscsi_target_tx_thread(void *);
extern int iscsi_target_rx_thread(void *);
#define TARGET_THREAD_SET_COUNT 4
#define ISCSI_RX_THREAD 1
#define ISCSI_TX_THREAD 2
#define ISCSI_RX_THREAD_NAME "iscsi_trx"
#define ISCSI_TX_THREAD_NAME "iscsi_ttx"
#define ISCSI_BLOCK_RX_THREAD 0x1
#define ISCSI_BLOCK_TX_THREAD 0x2
#define ISCSI_CLEAR_RX_THREAD 0x1
#define ISCSI_CLEAR_TX_THREAD 0x2
#define ISCSI_SIGNAL_RX_THREAD 0x1
#define ISCSI_SIGNAL_TX_THREAD 0x2
/* struct iscsi_thread_set->status */
#define ISCSI_THREAD_SET_FREE 1
#define ISCSI_THREAD_SET_ACTIVE 2
#define ISCSI_THREAD_SET_DIE 3
#define ISCSI_THREAD_SET_RESET 4
#define ISCSI_THREAD_SET_DEALLOCATE_THREADS 5
/* By default allow a maximum of 32K iSCSI connections */
#define ISCSI_TS_BITMAP_BITS 32768
struct iscsi_thread_set {
/* flags used for blocking and restarting sets */
int blocked_threads;
/* flag for creating threads */
int create_threads;
/* flag for delaying readding to inactive list */
int delay_inactive;
/* status for thread set */
int status;
/* which threads have had signals sent */
int signal_sent;
/* flag for which threads exited first */
int thread_clear;
/* Active threads in the thread set */
int thread_count;
/* Unique thread ID */
u32 thread_id;
/* pointer to connection if set is active */
struct iscsi_conn *conn;
/* used for controlling ts state accesses */
spinlock_t ts_state_lock;
/* used for restarting thread queue */
struct completion rx_restart_comp;
/* used for restarting thread queue */
struct completion tx_restart_comp;
/* used for normal unused blocking */
struct completion rx_start_comp;
/* used for normal unused blocking */
struct completion tx_start_comp;
/* OS descriptor for rx thread */
struct task_struct *rx_thread;
/* OS descriptor for tx thread */
struct task_struct *tx_thread;
/* struct iscsi_thread_set in list list head*/
struct list_head ts_list;
struct semaphore ts_activate_sem;
};
#endif /*** ISCSI_THREAD_QUEUE_H ***/
......@@ -33,7 +33,6 @@
#include "iscsi_target_erl1.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_tq.h"
#include "iscsi_target_util.h"
#include "iscsi_target.h"
......
......@@ -20,6 +20,8 @@
#define ISCSIT_MIN_TAGS 16
#define ISCSIT_EXTRA_TAGS 8
#define ISCSIT_TCP_BACKLOG 256
#define ISCSI_RX_THREAD_NAME "iscsi_trx"
#define ISCSI_TX_THREAD_NAME "iscsi_ttx"
/* struct iscsi_node_attrib sanity values */
#define NA_DATAOUT_TIMEOUT 3
......@@ -600,8 +602,6 @@ struct iscsi_conn {
struct iscsi_tpg_np *tpg_np;
/* Pointer to parent session */
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;
......@@ -877,8 +877,6 @@ struct iscsit_global {
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;
......
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