This has us use the blk/scsi-ml mq cmd pre-allocator and blk tags
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 | 124 +++++++++++++++++++++++-------------------------
include/scsi/libiscsi.h | 26 ++++++----
2 files changed, 77 insertions(+), 73 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 2b3dd42..ef9fd93 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -498,8 +498,6 @@ static void iscsi_free_task(struct iscsi_task *task)
if (conn->login_task == task)
return;
- kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
-
/*
* if the window opened when we processed a data/r2t pdu make sure we
* see the updated win_opened value.
@@ -510,7 +508,9 @@ static void iscsi_free_task(struct iscsi_task *task)
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;
/*
@@ -749,8 +749,8 @@ 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,
- (void*)&task, sizeof(void*)))
+ if (!kfifo_out(&session->mgmt_pool.queue, (void *)&task,
+ sizeof(void *)))
return NULL;
}
/*
@@ -1160,10 +1160,12 @@ struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
session->tt->parse_pdu_itt(conn, itt, &i, NULL);
else
i = get_itt(itt);
- if (i >= session->cmds_max)
+ i = i >> ISCSI_MGMT_SHIFT;
+
+ if (i >= ISCSI_MGMT_CMDS_MAX)
return NULL;
- return session->cmds[i];
+ return session->mgmt_cmds[i];
}
EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
@@ -1353,12 +1355,6 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
return ISCSI_ERR_BAD_ITT;
}
- if (i >= session->cmds_max) {
- iscsi_conn_printk(KERN_ERR, conn,
- "received invalid itt index %u (max cmds "
- "%u.\n", i, session->cmds_max);
- return ISCSI_ERR_BAD_ITT;
- }
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_verify_itt);
@@ -1374,19 +1370,30 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
*/
struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
{
+ struct iscsi_session *session = conn->session;
struct iscsi_task *task;
+ struct scsi_cmnd *sc;
+ int tag;
if (iscsi_verify_itt(conn, itt))
return NULL;
- task = iscsi_itt_to_task(conn, itt);
- if (!task || !task->sc)
+ if (session->tt->parse_pdu_itt)
+ session->tt->parse_pdu_itt(conn, itt, &tag, NULL);
+ else
+ tag = get_itt(itt);
+ sc = scsi_host_find_tag(session->host, tag);
+ if (!sc)
+ return NULL;
+
+ task = scsi_cmd_priv(sc);
+ if (!task->sc)
return NULL;
- if (task->sc->SCp.phase != conn->session->age) {
+ if (task->sc->SCp.phase != session->age) {
iscsi_session_printk(KERN_ERR, conn->session,
"task's session age %d, expected %d\n",
- task->sc->SCp.phase, conn->session->age);
+ task->sc->SCp.phase, session->age);
return NULL;
}
@@ -1649,19 +1656,16 @@ 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;
refcount_set(&task->refcount, 1);
+ task->itt = blk_mq_unique_tag(sc->request);
task->state = ISCSI_TASK_PENDING;
task->conn = conn;
task->sc = sc;
@@ -1758,22 +1762,16 @@ 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;
@@ -1808,7 +1806,7 @@ 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;
@@ -2942,21 +2940,18 @@ struct iscsi_cls_session *
spin_lock_init(&session->frwd_lock);
spin_lock_init(&session->back_lock);
- /* initialize SCSI PDU commands pool */
- if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
- (void***)&session->cmds,
+ /* initialize mgmt task 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;
+ goto mgmt_pool_alloc_fail;
/* pre-format cmds pool with ITT */
- for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
- struct iscsi_task *task = session->cmds[cmd_i];
+ for (cmd_i = 0; cmd_i < ISCSI_MGMT_CMDS_MAX; cmd_i++) {
+ struct iscsi_task *task = session->mgmt_cmds[cmd_i];
- if (cmd_task_size)
- task->dd_data = &task[1];
- task->itt = cmd_i;
- task->state = ISCSI_TASK_FREE;
- INIT_LIST_HEAD(&task->running);
+ iscsi_init_task(task);
+ task->itt = cmd_i << ISCSI_MGMT_SHIFT;
if (iscsit->alloc_task_priv) {
if (iscsit->alloc_task_priv(session, task))
@@ -2977,11 +2972,11 @@ struct iscsi_cls_session *
free_task_priv:
for (cmd_i--; cmd_i >= 0; cmd_i--) {
if (iscsit->free_task_priv)
- iscsit->free_task_priv(session, session->cmds[cmd_i]);
+ iscsit->free_task_priv(session, session->mgmt_cmds[cmd_i]);
}
- iscsi_pool_free(&session->cmdpool);
-cmdpool_alloc_fail:
+ iscsi_pool_free(&session->mgmt_pool);
+mgmt_pool_alloc_fail:
iscsi_free_session(cls_session);
dec_session_count:
iscsi_host_dec_session_cnt(shost);
@@ -3000,13 +2995,13 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
struct Scsi_Host *shost = session->host;
int cmd_i;
- for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
+ for (cmd_i = 0; cmd_i < ISCSI_MGMT_CMDS_MAX; cmd_i++) {
if (session->tt->free_task_priv)
session->tt->free_task_priv(session,
- session->cmds[cmd_i]);
+ session->mgmt_cmds[cmd_i]);
}
- iscsi_pool_free(&session->cmdpool);
+ iscsi_pool_free(&session->mgmt_pool);
iscsi_remove_session(cls_session);
@@ -3070,9 +3065,8 @@ 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,
- (void*)&conn->login_task,
- sizeof(void*))) {
+ if (!kfifo_out(&session->mgmt_pool.queue, (void *)&conn->login_task,
+ sizeof(void *))) {
spin_unlock_bh(&session->frwd_lock);
goto login_task_alloc_fail;
}
@@ -3090,8 +3084,8 @@ struct iscsi_cls_conn *
return cls_conn;
login_task_data_alloc_fail:
- kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
- sizeof(void*));
+ kfifo_in(&session->mgmt_pool.queue, (void*)&conn->login_task,
+ sizeof(void *));
login_task_alloc_fail:
iscsi_destroy_conn(cls_conn);
return NULL;
@@ -3134,8 +3128,8 @@ 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,
- sizeof(void*));
+ kfifo_in(&session->mgmt_pool.queue, (void *)&conn->login_task,
+ sizeof(void *));
spin_unlock_bh(&session->back_lock);
if (session->leadconn == conn)
session->leadconn = NULL;
@@ -3219,8 +3213,8 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
struct iscsi_task *task;
int i, state;
- for (i = 0; i < conn->session->cmds_max; i++) {
- task = conn->session->cmds[i];
+ for (i = 0; i < ISCSI_MGMT_CMDS_MAX; i++) {
+ task = conn->session->mgmt_cmds[i];
if (task->sc)
continue;
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 96aaf4b..7be30e0 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -36,7 +36,7 @@
struct device;
#define ISCSI_DEF_XMIT_CMDS_MAX 128 /* must be power of 2 */
-#define ISCSI_MGMT_CMDS_MAX 15
+#define ISCSI_MGMT_CMDS_MAX 4
#define ISCSI_DEF_CMD_PER_LUN 32
@@ -55,8 +55,18 @@ enum {
/* Connection suspend "bit" */
#define ISCSI_SUSPEND_BIT 1
-#define ISCSI_ITT_MASK 0x1fff
-#define ISCSI_TOTAL_CMDS_MAX 4096
+/*
+ * Note:
+ * qedi uses 16 bits for it's tag.
+ * bnx2i needs the tag to be <= 0x3FFF to fit in its fw req.
+ * cxgbi assumes the tag will be at most 0x7fff.
+ * qla4xxx/be2iscsi ignore/fake the libiscsi tag.
+ */
+#define ISCSI_ITT_MASK (ISCSI_ITT_CMD_MASK | ISCSI_MGMT_ITT_MASK)
+#define ISCSI_ITT_CMD_MASK 0x3fff
+#define ISCSI_TOTAL_CMDS_MAX 16384
+#define ISCSI_MGMT_ITT_MASK 0x3000
+#define ISCSI_MGMT_SHIFT 12
/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
#define ISCSI_TOTAL_CMDS_MIN 16
#define ISCSI_AGE_SHIFT 28
@@ -330,18 +340,18 @@ struct iscsi_session {
* in the eh paths, cmdsn *
* suspend bit and session *
* resources: *
- * - cmdpool kfifo_out , *
- * - mgmtpool, queues */
+ * - mgmt_pool, kfifo_out, *
+ * - queues */
spinlock_t back_lock; /* protects cmdsn_exp *
* cmdsn_max, *
- * cmdpool kfifo_in */
+ * mgmt_pool kfifo_i */
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 **mgmt_cmds; /* mgmt task arr */
+ struct iscsi_pool mgmt_pool; /* mgmt task pool */
void *dd_data; /* LLD private data */
};
--
1.8.3.1
