diff options
author | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-07-23 06:43:04 +0000 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-07-26 09:16:43 +0000 |
commit | e48354ce078c079996f89d715dfa44814b4eba01 (patch) | |
tree | 7a593b6dd4864073944160fe227aae5d54e587ab /drivers/target/iscsi/iscsi_target_tq.c | |
parent | 8304bbceee505742925b487fd8ea56e1f8b4b805 (diff) | |
download | linux-e48354ce078c079996f89d715dfa44814b4eba01.tar.gz linux-e48354ce078c079996f89d715dfa44814b4eba01.tar.bz2 linux-e48354ce078c079996f89d715dfa44814b4eba01.zip |
iscsi-target: Add iSCSI fabric support for target v4.1
The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel. More information can be found here:
http://linux-iscsi.org/wiki/ISCSI
This includes support for:
* RFC-3720 defined request / response state machines and support for
all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
include/scsi/iscsi_proto.h PDU definitions
* Target v4.1 compatible control plane using the generic layout in
target_core_fabric_configfs.c and fabric dependent attributes
within /sys/kernel/config/target/iscsi/ subdirectories.
* Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
* Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
* iSCSI Error Recovery Hierarchy support
* Per iSCSI connection RX/TX thread pair scheduling affinity
* crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
* CHAP Authentication support using libcrypto
* Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
transport_generic_map_mem_to_cmd()
(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/iscsi/iscsi_target_tq.c')
-rw-r--r-- | drivers/target/iscsi/iscsi_target_tq.c | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/drivers/target/iscsi/iscsi_target_tq.c b/drivers/target/iscsi/iscsi_target_tq.c new file mode 100644 index 000000000000..0baac5bcebd4 --- /dev/null +++ b/drivers/target/iscsi/iscsi_target_tq.c @@ -0,0 +1,551 @@ +/******************************************************************************* + * This file contains the iSCSI Login Thread and Thread Queue functions. + * + * \u00a9 Copyright 2007-2011 RisingTide Systems LLC. + * + * Licensed to the Linux Foundation under the General Public License (GPL) version 2. + * + * 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 "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); +} + +extern 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; + } + + list_for_each_entry(ts, &inactive_ts_list, ts_list) + break; + + list_del(&ts->ts_list); + iscsit_global->inactive_ts--; + spin_unlock(&inactive_ts_lock); + + return ts; +} + +extern 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_post_start_comp); + init_completion(&ts->tx_post_start_comp); + init_completion(&ts->rx_restart_comp); + init_completion(&ts->tx_restart_comp); + init_completion(&ts->rx_start_comp); + init_completion(&ts->tx_start_comp); + + 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; +} + +extern void iscsi_deallocate_thread_sets(void) +{ + u32 released_count = 0; + struct iscsi_thread_set *ts = NULL; + + while ((ts = iscsi_get_ts_from_inactive_list())) { + + spin_lock_bh(&ts->ts_state_lock); + ts->status = ISCSI_THREAD_SET_DIE; + spin_unlock_bh(&ts->ts_state_lock); + + if (ts->rx_thread) { + send_sig(SIGINT, ts->rx_thread, 1); + kthread_stop(ts->rx_thread); + } + if (ts->tx_thread) { + send_sig(SIGINT, ts->tx_thread, 1); + kthread_stop(ts->tx_thread); + } + /* + * 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); + + released_count++; + kfree(ts); + } + + 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; + + spin_lock_bh(&ts->ts_state_lock); + ts->status = ISCSI_THREAD_SET_DIE; + spin_unlock_bh(&ts->ts_state_lock); + + if (ts->rx_thread) { + send_sig(SIGINT, ts->rx_thread, 1); + kthread_stop(ts->rx_thread); + } + if (ts->tx_thread) { + send_sig(SIGINT, ts->tx_thread, 1); + kthread_stop(ts->tx_thread); + } + /* + * 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); + + released_count++; + kfree(ts); + } + + 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; + spin_unlock_bh(&ts->ts_state_lock); + /* + * Start up the RX thread and wait on rx_post_start_comp. The RX + * Thread will then do the same for the TX Thread in + * iscsi_rx_thread_pre_handler(). + */ + complete(&ts->rx_start_comp); + wait_for_completion(&ts->rx_post_start_comp); +} + +struct iscsi_thread_set *iscsi_get_thread_set(void) +{ + int allocate_ts = 0; + struct completion comp; + struct iscsi_thread_set *ts = NULL; + /* + * If no inactive thread set is available on the first call to + * iscsi_get_ts_from_inactive_list(), sleep for a second and + * try again. If still none are available after two attempts, + * allocate a set ourselves. + */ +get_set: + ts = iscsi_get_ts_from_inactive_list(); + if (!ts) { + if (allocate_ts == 2) + iscsi_allocate_thread_sets(1); + + init_completion(&comp); + wait_for_completion_timeout(&comp, 1 * HZ); + + allocate_ts++; + 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); + + 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) || 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; + } + + flush_signals(current); + + if (ts->delay_inactive && (--ts->thread_count == 0)) { + spin_unlock_bh(&ts->ts_state_lock); + iscsi_del_ts_from_active_list(ts); + + 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; + + if (!ts->conn) { + pr_err("struct iscsi_thread_set->conn is NULL for" + " thread_id: %d, going back to sleep\n", ts->thread_id); + goto sleep; + } + iscsi_check_to_add_additional_sets(); + /* + * The RX Thread starts up the TX Thread and sleeps. + */ + ts->thread_clear |= ISCSI_CLEAR_RX_THREAD; + complete(&ts->tx_start_comp); + wait_for_completion(&ts->tx_post_start_comp); + + 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; + } + + flush_signals(current); + + if (ts->delay_inactive && (--ts->thread_count == 0)) { + spin_unlock_bh(&ts->ts_state_lock); + iscsi_del_ts_from_active_list(ts); + + 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; + + if (!ts->conn) { + pr_err("struct iscsi_thread_set->conn is NULL for " + " thread_id: %d, going back to sleep\n", + ts->thread_id); + goto sleep; + } + + iscsi_check_to_add_additional_sets(); + /* + * From the TX thread, up the tx_post_start_comp that the RX Thread is + * sleeping on in iscsi_rx_thread_pre_handler(), then up the + * rx_post_start_comp that iscsi_activate_thread_set() is sleeping on. + */ + ts->thread_clear |= ISCSI_CLEAR_TX_THREAD; + complete(&ts->tx_post_start_comp); + complete(&ts->rx_post_start_comp); + + spin_lock_bh(&ts->ts_state_lock); + ts->status = ISCSI_THREAD_SET_ACTIVE; + spin_unlock_bh(&ts->ts_state_lock); + + 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; + } + + spin_lock_init(&active_ts_lock); + spin_lock_init(&inactive_ts_lock); + spin_lock_init(&ts_bitmap_lock); + INIT_LIST_HEAD(&active_ts_list); + INIT_LIST_HEAD(&inactive_ts_list); + + return 0; +} + +void iscsi_thread_set_free(void) +{ + kfree(iscsit_global->ts_bitmap); +} |