From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch converts the iscsi_thread_queue.c:iscsi_allocate_thread_sets()
to use a iscsi_global->ts_bitmap and lib/bitmap.c:bitmap_find_free_region()
for handling the allocation of the unique thread_id per thread_set. It also
includes the addtion of bitmap_release_region() in the thread_set release
patch in iscsi_deallocate_thread_sets() and iscsi_deallocate_extra_thread_sets().
This patch ensures by using bitmap_find_free_region() that the lowest free thread_id
will be always allocated.
This patch also includes adding iscsi_thread_set_init() and iscsi_thread_set_free()
which are called during module init/free to handle the kzalloc() / kfree()
of iscsi_global->ts_bitmap. Also note that this includes:
/* By default allow a maximum of 32K iSCSI connections */
#define ISCSI_TS_BITMAP_BITS 32768
which is used as the hardcoded maximum of the iscsi_global->ts_bitmap. This
should be a reasonable default for some time into the future, but having this
value becoming a iscsi_target_mod module parameter may also be useful.
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/lio-target/iscsi_target.c | 11 +++--
drivers/target/lio-target/iscsi_target_core.h | 8 +++-
drivers/target/lio-target/iscsi_thread_queue.c | 58 +++++++++++++++++++++--
drivers/target/lio-target/iscsi_thread_queue.h | 5 ++
4 files changed, 71 insertions(+), 11 deletions(-)
diff --git a/drivers/target/lio-target/iscsi_target.c b/drivers/target/lio-target/iscsi_target.c
index 59f3e87..9b7c86c 100644
--- a/drivers/target/lio-target/iscsi_target.c
+++ b/drivers/target/lio-target/iscsi_target.c
@@ -821,6 +821,7 @@ static int init_iscsi_global(struct iscsi_global *global)
spin_lock_init(&global->np_lock);
spin_lock_init(&global->shutdown_lock);
spin_lock_init(&global->tiqn_lock);
+ spin_lock_init(&global->ts_bitmap_lock);
spin_lock_init(&global->g_tpg_lock);
INIT_LIST_HEAD(&global->g_tiqn_list);
INIT_LIST_HEAD(&global->g_tpg_list);
@@ -969,6 +970,8 @@ static int iscsi_target_detect(void)
init_iscsi_target_mib();
iscsi_target_register_configfs();
+ iscsi_thread_set_init();
+
if (iscsi_allocate_thread_sets(TARGET_THREAD_SET_COUNT, TARGET) !=
TARGET_THREAD_SET_COUNT) {
printk(KERN_ERR "iscsi_allocate_thread_sets() returned"
@@ -1074,6 +1077,7 @@ out:
if (lio_tpg_cache)
kmem_cache_destroy(lio_tpg_cache);
iscsi_deallocate_thread_sets(TARGET);
+ iscsi_thread_set_free();
iscsi_target_deregister_configfs();
remove_iscsi_target_mib();
@@ -1117,6 +1121,7 @@ void iscsi_target_release_phase2(void)
core_reset_nps();
iscsi_disable_all_tpgs();
iscsi_deallocate_thread_sets(TARGET);
+ iscsi_thread_set_free();
iscsi_remove_all_tpgs();
core_release_nps();
core_release_discovery_tpg();
@@ -4452,11 +4457,10 @@ int iscsi_target_tx_thread(void *arg)
struct se_unmap_sg unmap_sg;
{
- static unsigned int x = 1; /* unique number added to thread name */
char name[20];
memset(name, 0, 20);
- sprintf(name, "%s/%u", ISCSI_TX_THREAD_NAME, x++);
+ sprintf(name, "%s/%u", ISCSI_TX_THREAD_NAME, ts->thread_id);
iscsi_daemon(ts->tx_thread, name, SHUTDOWN_SIGS);
}
@@ -4800,11 +4804,10 @@ int iscsi_target_rx_thread(void *arg)
struct scatterlist sg;
{
- static unsigned int x = 1; /* unique number added to thread name */
char name[20];
memset(name, 0, 20);
- sprintf(name, "%s/%u", ISCSI_RX_THREAD_NAME, x++);
+ sprintf(name, "%s/%u", ISCSI_RX_THREAD_NAME, ts->thread_id);
iscsi_daemon(ts->rx_thread, name, SHUTDOWN_SIGS);
}
diff --git a/drivers/target/lio-target/iscsi_target_core.h b/drivers/target/lio-target/iscsi_target_core.h
index 0673d2c..733f09f 100644
--- a/drivers/target/lio-target/iscsi_target_core.h
+++ b/drivers/target/lio-target/iscsi_target_core.h
@@ -907,8 +907,10 @@ struct iscsi_global {
/* Unique identifier used for the authentication daemon */
u32 auth_id;
u32 inactive_ts;
- /* Thread ID counter */
- u32 thread_id;
+ /* Thread Set bitmap count */
+ int ts_bitmap_count;
+ /* Thread Set bitmap pointer */
+ unsigned long *ts_bitmap;
int (*ti_forcechanoffline)(void *);
struct list_head g_tiqn_list;
struct list_head g_tpg_list;
@@ -924,6 +926,8 @@ struct iscsi_global {
spinlock_t shutdown_lock;
/* Spinlock for adding/removing thread sets */
spinlock_t thread_set_lock;
+ /* Spinlock for iscsi_global->ts_bitmap */
+ spinlock_t ts_bitmap_lock;
/* Spinlock for struct iscsi_tiqn */
spinlock_t tiqn_lock;
spinlock_t g_tpg_lock;
diff --git a/drivers/target/lio-target/iscsi_thread_queue.c b/drivers/target/lio-target/iscsi_thread_queue.c
index f63169e..8009332 100644
--- a/drivers/target/lio-target/iscsi_thread_queue.c
+++ b/drivers/target/lio-target/iscsi_thread_queue.c
@@ -32,6 +32,7 @@
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/list.h>
+#include <linux/bitmap.h>
#include <iscsi_debug.h>
#include <iscsi_protocol.h>
@@ -118,7 +119,7 @@ static struct se_thread_set *iscsi_get_ts_from_inactive_list(void)
*/
extern int iscsi_allocate_thread_sets(u32 thread_pair_count, int role)
{
- int allocated_thread_pair_count = 0, i;
+ int allocated_thread_pair_count = 0, i, thread_id;
struct se_thread_set *ts = NULL;
for (i = 0; i < thread_pair_count; i++) {
@@ -128,7 +129,21 @@ extern int iscsi_allocate_thread_sets(u32 thread_pair_count, int role)
" thread set.\n");
return allocated_thread_pair_count;
}
+ /*
+ * Locate the next available regision in the thread_set_bitmap
+ */
+ spin_lock(&iscsi_global->ts_bitmap_lock);
+ thread_id = bitmap_find_free_region(iscsi_global->ts_bitmap,
+ iscsi_global->ts_bitmap_count, get_order(1));
+ spin_unlock(&iscsi_global->ts_bitmap_lock);
+ if (thread_id < 0) {
+ printk(KERN_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);
@@ -144,10 +159,6 @@ extern int iscsi_allocate_thread_sets(u32 thread_pair_count, int role)
init_MUTEX_LOCKED(&ts->rx_start_sem);
init_MUTEX_LOCKED(&ts->tx_start_sem);
- ts->thread_id = iscsi_global->thread_id++;
- if (!ts->thread_id)
- ts->thread_id = iscsi_global->thread_id++;
-
ts->create_threads = 1;
kernel_thread(iscsi_target_rx_thread,
(void *)ts, 0);
@@ -195,6 +206,14 @@ extern void iscsi_deallocate_thread_sets(int role)
#if 0
printk(KERN_INFO "Deallocated THREAD_ID: %d\n", ts->thread_id);
#endif
+ /*
+ * Release this thread_id in the thread_set_bitmap
+ */
+ spin_lock(&iscsi_global->ts_bitmap_lock);
+ bitmap_release_region(iscsi_global->ts_bitmap,
+ ts->thread_id, get_order(1));
+ spin_unlock(&iscsi_global->ts_bitmap_lock);
+
released_count++;
kfree(ts);
}
@@ -238,6 +257,14 @@ static void iscsi_deallocate_extra_thread_sets(int role)
#if 0
printk(KERN_INFO "Deallocated THREAD_ID: %d\n", ts->thread_id);
#endif
+ /*
+ * Release this thread_id in the thread_set_bitmap
+ */
+ spin_lock(&iscsi_global->ts_bitmap_lock);
+ bitmap_release_region(iscsi_global->ts_bitmap,
+ ts->thread_id, get_order(1));
+ spin_unlock(&iscsi_global->ts_bitmap_lock);
+
released_count++;
kfree(ts);
}
@@ -652,3 +679,24 @@ sleep:
spin_unlock_bh(&ts->ts_state_lock);
return ts->conn;
}
+
+int iscsi_thread_set_init(void)
+{
+ int size;
+
+ iscsi_global->ts_bitmap_count = ISCSI_TS_BITMAP_BITS;
+
+ size = BITS_TO_LONGS(iscsi_global->ts_bitmap_count) * sizeof(long);
+ iscsi_global->ts_bitmap = kzalloc(size, GFP_KERNEL);
+ if (!(iscsi_global->ts_bitmap)) {
+ printk(KERN_ERR "Unable to allocate iscsi_global->ts_bitmap\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+void iscsi_thread_set_free(void)
+{
+ kfree(iscsi_global->ts_bitmap);
+}
diff --git a/drivers/target/lio-target/iscsi_thread_queue.h b/drivers/target/lio-target/iscsi_thread_queue.h
index c2aaa57..d44e4a6 100644
--- a/drivers/target/lio-target/iscsi_thread_queue.h
+++ b/drivers/target/lio-target/iscsi_thread_queue.h
@@ -15,6 +15,8 @@ extern void iscsi_set_thread_set_signal(struct iscsi_conn *, u8);
extern int iscsi_release_thread_set(struct iscsi_conn *, int);
extern struct iscsi_conn *iscsi_rx_thread_pre_handler(struct se_thread_set *, int);
extern struct iscsi_conn *iscsi_tx_thread_pre_handler(struct se_thread_set *, int);
+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 *);
@@ -41,6 +43,9 @@ extern struct iscsi_global *iscsi_global;
#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 se_thread_set {
/* flags used for blocking and restarting sets */
u8 blocked_threads;
--
1.5.6.5
--
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