+++ /dev/null
-/*******************************************************************************
- * 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);
-}
+++ /dev/null
-#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 ***/
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