/*
* This file contains the iSCSI Login Thread and Thread Queue functions.
*/
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/bitmap.h>
#include "iscsi_target_core.h"
#include "iscsi_target_tq.h"
#include "iscsi_target.h"
static LIST_HEAD(active_ts_list);
static LIST_HEAD(inactive_ts_list);
static DEFINE_SPINLOCK(active_ts_lock);
static DEFINE_SPINLOCK(inactive_ts_lock);
static DEFINE_SPINLOCK(ts_bitmap_lock);
static void iscsi_add_ts_to_active_list(struct iscsi_thread_set *ts)
{
spin_lock(&active_ts_lock);
list_add_tail(&ts->ts_list, &active_ts_list);
iscsit_global->active_ts++;
spin_unlock(&active_ts_lock);
}
static void iscsi_add_ts_to_inactive_list(struct iscsi_thread_set *ts)
{
spin_lock(&inactive_ts_lock);
list_add_tail(&ts->ts_list, &inactive_ts_list);
iscsit_global->inactive_ts++;
spin_unlock(&inactive_ts_lock);
}
static void iscsi_del_ts_from_active_list(struct iscsi_thread_set *ts)
{
spin_lock(&active_ts_lock);
list_del(&ts->ts_list);
iscsit_global->active_ts--;
spin_unlock(&active_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(&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)
{
iscsi_add_ts_to_active_list(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
