This has us use the blk/scsi-ml mq cmd pre-allocator for scsi tasks.
We now do not need the back/frwd locks for scsi task allocation.
We still need it for mgmt tasks, but that will be fixed in the next
patch.
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
---
drivers/scsi/libiscsi.c | 84 ++++++++++++++++++-------------------------------
include/scsi/libiscsi.h | 13 +++++---
2 files changed, 38 insertions(+), 59 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index ea1ef77..85c6730 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -547,14 +547,15 @@ static void iscsi_free_task(struct iscsi_task *task)
return;
iscsi_free_itt(session, task);
- kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
if (session->win_opened && !work_pending(&conn->xmitwork)) {
session->win_opened = false;
iscsi_conn_queue_work(conn);
}
- if (sc) {
+ if (!sc) {
+ kfifo_in(&session->mgmt_pool.queue, (void*)&task, sizeof(void*));
+ } else {
/* SCSI eh reuses commands to verify us */
sc->SCp.ptr = NULL;
/*
@@ -803,13 +804,13 @@ static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
- if (!kfifo_out(&session->cmdpool.queue,
+ if (!kfifo_out(&session->mgmt_pool.queue,
(void*)&task, sizeof(void*)))
return NULL;
if (iscsi_alloc_itt(session, task)) {
spin_lock(&session->back_lock);
- kfifo_in(&session->cmdpool.queue, (void*)&task,
+ kfifo_in(&session->mgmt_pool.queue, (void*)&task,
sizeof(void*));
spin_unlock(&session->back_lock);
return NULL;
@@ -1712,14 +1713,10 @@ static void iscsi_xmitworker(struct work_struct *work)
} while (rc >= 0 || rc == -EAGAIN);
}
-static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
- struct scsi_cmnd *sc)
+static struct iscsi_task *iscsi_init_scsi_task(struct iscsi_conn *conn,
+ struct scsi_cmnd *sc)
{
- struct iscsi_task *task;
-
- if (!kfifo_out(&conn->session->cmdpool.queue,
- (void *) &task, sizeof(void *)))
- return NULL;
+ struct iscsi_task *task = scsi_cmd_priv(sc);
sc->SCp.phase = conn->session->age;
sc->SCp.ptr = (char *) task;
@@ -1822,22 +1819,16 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
goto fault;
}
- spin_lock_bh(&session->frwd_lock);
- if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
- spin_unlock_bh(&session->frwd_lock);
- reason = FAILURE_SESSION_IN_RECOVERY;
- sc->result = DID_REQUEUE << 16;
- goto fault;
- }
-
- task = iscsi_alloc_task(conn, sc);
- if (!task) {
- spin_unlock_bh(&session->frwd_lock);
- reason = FAILURE_OOM;
- goto reject;
- }
+ task = iscsi_init_scsi_task(conn, sc);
+ spin_lock_bh(&session->frwd_lock);
if (!ihost->workq) {
+ if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
+ reason = FAILURE_SESSION_IN_RECOVERY;
+ sc->result = DID_REQUEUE << 16;
+ goto prepd_fault;
+ }
+
if (iscsi_check_cmdsn_window_closed(conn)) {
reason = FAILURE_WINDOW_CLOSED;
goto prepd_reject;
@@ -1872,7 +1863,7 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
spin_lock_bh(&session->back_lock);
iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
spin_unlock_bh(&session->back_lock);
-reject:
+
ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
sc->cmnd[0], reason);
return SCSI_MLQUEUE_TARGET_BUSY;
@@ -2873,7 +2864,6 @@ struct iscsi_cls_session *
struct iscsi_session *session;
struct iscsi_cls_session *cls_session;
int cmd_i, scsi_cmds, total_cmds = cmds_max;
- struct iscsi_task *task;
unsigned long flags;
spin_lock_irqsave(&ihost->lock, flags);
@@ -2951,30 +2941,16 @@ struct iscsi_cls_session *
if (!session->cmds)
goto cmds_alloc_fail;
- /* initialize SCSI PDU commands pool */
- if (iscsi_pool_init(&session->cmdpool, session->cmds_max, NULL,
+ /* initialize mgmt PDU pool */
+ if (iscsi_pool_init(&session->mgmt_pool, ISCSI_MGMT_CMDS_MAX,
+ (void***)&session->mgmt_cmds,
cmd_task_size + sizeof(struct iscsi_task)))
- goto cmdpool_alloc_fail;
-
- /*
- * This is a temp change to allow drivers that prealloc task resources
- * during session setup to continue to work. The next patches convert
- * the drivers to use the blk/scsi-ml init/exit callouts then this
- * will be removed.
- */
- while (kfifo_out(&session->cmdpool.queue, (void *) &task,
- sizeof(void *))) {
- session->cmds[cmd_i++] = task;
+ goto mgmt_pool_alloc_fail;
- if (cmd_task_size)
- task->dd_data = &task[1];
- task->state = ISCSI_TASK_FREE;
- INIT_LIST_HEAD(&task->running);
- }
+ for (cmd_i = 0; cmd_i < ISCSI_MGMT_CMDS_MAX; cmd_i++) {
+ struct iscsi_task *task = session->mgmt_cmds[cmd_i];
- for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
- task = session->cmds[cmd_i];
- kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
+ iscsi_init_task(task);
}
if (!try_module_get(iscsit->owner))
@@ -2988,8 +2964,8 @@ struct iscsi_cls_session *
cls_session_fail:
module_put(iscsit->owner);
module_get_fail:
- iscsi_pool_free(&session->cmdpool);
-cmdpool_alloc_fail:
+ iscsi_pool_free(&session->mgmt_pool);
+mgmt_pool_alloc_fail:
kfree(session->cmds);
cmds_alloc_fail:
sbitmap_free(&session->itts);
@@ -3011,7 +2987,7 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
struct module *owner = cls_session->transport->owner;
struct Scsi_Host *shost = session->host;
- iscsi_pool_free(&session->cmdpool);
+ iscsi_pool_free(&session->mgmt_pool);
iscsi_remove_session(cls_session);
@@ -3078,7 +3054,7 @@ struct iscsi_cls_conn *
/* allocate login_task used for the login/text sequences */
spin_lock_bh(&session->frwd_lock);
- if (!kfifo_out(&session->cmdpool.queue,
+ if (!kfifo_out(&session->mgmt_pool.queue,
(void*)&conn->login_task,
sizeof(void*))) {
spin_unlock_bh(&session->frwd_lock);
@@ -3104,7 +3080,7 @@ struct iscsi_cls_conn *
iscsi_free_itt(session, conn->login_task);
login_itt_fail:
spin_lock_bh(&session->frwd_lock);
- kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
+ kfifo_in(&session->mgmt_pool.queue, (void*)&conn->login_task,
sizeof(void*));
spin_unlock_bh(&session->frwd_lock);
login_task_alloc_fail:
@@ -3149,7 +3125,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
kfree(conn->local_ipaddr);
/* regular RX path uses back_lock */
spin_lock_bh(&session->back_lock);
- kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
+ kfifo_in(&session->mgmt_pool.queue, (void*)&conn->login_task,
sizeof(void*));
spin_unlock_bh(&session->back_lock);
iscsi_free_itt(session, conn->login_task);
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index c2283f9..1c851b6 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -331,19 +331,22 @@ struct iscsi_session {
* in the eh paths, cmdsn *
* suspend bit and session *
* resources: *
- * - cmdpool kfifo_out , *
- * - mgmtpool, queues */
+ * - kfifo_out mgmt_pool, *
+ * - queues */
spinlock_t back_lock; /* protects cmdsn_exp *
* cmdsn_max, *
- * cmdpool kfifo_in */
+ * mgmt_pool kfifo_in */
int state; /* session state */
int age; /* counts session re-opens */
int scsi_cmds_max; /* max scsi commands */
int cmds_max; /* size of cmds array */
- struct iscsi_task **cmds; /* Original Cmds arr */
- struct iscsi_pool cmdpool; /* PDU's pool */
+ struct iscsi_task **cmds; /* Lookup map of all tasks */
struct sbitmap itts;
+
+ struct iscsi_task **mgmt_cmds;
+ struct iscsi_pool mgmt_pool;
+
void *dd_data; /* LLD private data */
};
--
1.8.3.1
