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 patches.
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
---
drivers/scsi/cxgbi/libcxgbi.c | 2 +-
drivers/scsi/libiscsi.c | 151 +++++++++++++++++++---------------
include/scsi/libiscsi.h | 46 +++++++----
3 files changed, 116 insertions(+), 83 deletions(-)
diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c
index 919451810018..cdaa67fd8c2e 100644
--- a/drivers/scsi/cxgbi/libcxgbi.c
+++ b/drivers/scsi/cxgbi/libcxgbi.c
@@ -366,7 +366,7 @@ int cxgbi_hbas_add(struct cxgbi_device *cdev, u64 max_lun,
chba->ndev = cdev->ports[i];
chba->shost = shost;
- shost->can_queue = sht->can_queue - ISCSI_MGMT_CMDS_MAX;
+ shost->can_queue = sht->can_queue - ISCSI_INFLIGHT_MGMT_MAX;
log_debug(1 << CXGBI_DBG_DEV,
"cdev 0x%p, p#%d %s: chba 0x%p.\n",
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index cadbe1d19344..46ab51e5a87b 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -463,9 +463,9 @@ 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 (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;
/*
@@ -716,8 +716,8 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
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;
}
/*
@@ -1118,7 +1118,7 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
{
struct iscsi_session *session = conn->session;
- int i;
+ uint32_t i;
if (itt == RESERVED_ITT)
return NULL;
@@ -1127,10 +1127,17 @@ 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)
- return NULL;
- return session->cmds[i];
+ if (i & ISCSI_TASK_TYPE_MGMT) {
+ i &= ~ISCSI_TASK_TYPE_MGMT;
+
+ if (i >= ISCSI_MGMT_CMDS_MAX)
+ return NULL;
+
+ return session->mgmt_cmds[i];
+ } else {
+ return iscsi_itt_to_ctask(conn, itt);
+ }
}
EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
@@ -1348,12 +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);
@@ -1369,19 +1370,30 @@ EXPORT_SYMBOL_GPL(iscsi_verify_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;
- if (task->sc->SCp.phase != conn->session->age) {
+ task = scsi_cmd_priv(sc);
+ if (!task->sc)
+ return NULL;
+
+ 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;
}
@@ -1679,19 +1691,16 @@ 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;
@@ -1805,12 +1814,7 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
goto reject;
}
- 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);
if (!ihost->workq) {
reason = iscsi_prep_scsi_cmd_pdu(task);
@@ -2745,9 +2749,8 @@ int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
if (!total_cmds)
total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
/*
- * The iscsi layer needs some tasks for nop handling and tmfs,
- * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
- * + 1 command for scsi IO.
+ * The iscsi layer needs some tasks for nop handling and tmfs, so the
+ * cmds_max must at least be greater than ISCSI_INFLIGHT_MGMT_MAX
*/
if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
@@ -2773,7 +2776,7 @@ int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
requested_cmds_max, total_cmds);
}
- scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
+ scsi_cmds = total_cmds - ISCSI_INFLIGHT_MGMT_MAX;
if (shost->can_queue && scsi_cmds > shost->can_queue) {
total_cmds = shost->can_queue;
@@ -2799,9 +2802,25 @@ int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
if (!shost->can_queue)
shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
+ if (shost->can_queue > ISCSI_TOTAL_CMDS_MAX) {
+ shost_printk(KERN_INFO, shost,
+ "Requested scsi host can_queue was %u. Limiting to %u\n",
+ shost->can_queue, ISCSI_TOTAL_CMDS_MAX);
+ shost->can_queue = ISCSI_TOTAL_CMDS_MAX;
+ }
+
if (!shost->cmd_per_lun)
shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
+ shost->host_tagset = 1;
+ /*
+ * We currently do not support nr_hw_queues > 1 because the iscsi spec
+ * itt is limited to 32 bits, and for drivers that support it, libiscsi
+ * uses some of the bits past BLK_MQ_UNIQUE_TAG_BITS for target sanity
+ * checks. Plus other drivers/fw can limit the itt to less than 16 bits.
+ */
+ BUG_ON(shost->nr_hw_queues > 1);
+
return scsi_add_host(shost, pdev);
}
EXPORT_SYMBOL_GPL(iscsi_host_add);
@@ -2914,9 +2933,11 @@ static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
scsi_host_put(shost);
}
-static void iscsi_init_task(struct iscsi_task *task)
+static void iscsi_init_task(struct iscsi_task *task, int dd_task_size)
{
task->dd_data = &task[1];
+ if (dd_task_size > 0)
+ memset(task->dd_data, 0, dd_task_size);
task->itt = ISCSI_RESERVED_TAG;
task->state = ISCSI_TASK_FREE;
INIT_LIST_HEAD(&task->running);
@@ -2926,7 +2947,7 @@ int iscsi_init_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *sc)
{
struct iscsi_task *task = scsi_cmd_priv(sc);
- iscsi_init_task(task);
+ iscsi_init_task(task, shost->hostt->cmd_size - sizeof(*task));
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_init_cmd_priv);
@@ -2945,8 +2966,8 @@ EXPORT_SYMBOL_GPL(iscsi_init_cmd_priv);
* a session per scsi host.
*
* Callers should set cmds_max to the largest total numer (mgmt + scsi) of
- * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
- * for nop handling and login/logout requests.
+ * tasks they support. The iscsi layer reserves ISCSI_INFLIGHT_MGMT_MAX
+ * tasks for nop handling and login/logout requests.
*/
struct iscsi_cls_session *
iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
@@ -2985,7 +3006,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
session->lu_reset_timeout = 15;
session->abort_timeout = 10;
session->scsi_cmds_max = scsi_cmds;
- session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
+ session->cmds_max = scsi_cmds + ISCSI_INFLIGHT_MGMT_MAX;
session->queued_cmdsn = session->cmdsn = initial_cmdsn;
session->exp_cmdsn = initial_cmdsn + 1;
session->max_cmdsn = initial_cmdsn + 1;
@@ -2997,21 +3018,18 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
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, cmd_task_size);
+ task->itt = cmd_i | ISCSI_TASK_TYPE_MGMT;
if (iscsit->alloc_task_priv) {
if (iscsit->alloc_task_priv(session, task))
@@ -3032,11 +3050,11 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
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);
@@ -3055,13 +3073,13 @@ 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);
@@ -3125,9 +3143,8 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
/* 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;
}
@@ -3145,8 +3162,8 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
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;
@@ -3189,8 +3206,8 @@ 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;
@@ -3275,8 +3292,8 @@ fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *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 8e01beba62f1..7a78f8c5d670 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -35,8 +35,18 @@ struct iscsi_session;
struct iscsi_nopin;
struct device;
-#define ISCSI_DEF_XMIT_CMDS_MAX 128 /* must be power of 2 */
-#define ISCSI_MGMT_CMDS_MAX 15
+#define ISCSI_DEF_XMIT_CMDS_MAX 128
+/*
+ * Max number of mgmt cmds we will preallocate and add to our mgmt fifo.
+ * This must be a pow of 2 due to the kfifo use.
+ */
+#define ISCSI_MGMT_CMDS_MAX 16
+/*
+ * For userspace compat we must allow at least 16 total cmds, so we have the
+ * the mgmt allocation limit above and this limit is the number of mgmt cmds
+ * that can be running.
+ */
+#define ISCSI_INFLIGHT_MGMT_MAX 15
#define ISCSI_DEF_CMD_PER_LUN 32
@@ -55,10 +65,19 @@ enum {
/* Connection suspend "bit" */
#define ISCSI_SUSPEND_BIT 1
-#define ISCSI_ITT_MASK 0x1fff
-#define ISCSI_TOTAL_CMDS_MAX 4096
-/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
-#define ISCSI_TOTAL_CMDS_MIN 16
+/*
+ * Note:
+ * - bnx2i needs the tag to be <= 0x3fff to fit in its fw req, and has a
+ * different itt space for scsi and mgmt cmds.
+ * - cxgbi assumes the tag will be at most 0x7fff.
+ * - iser needs the total cmds to be a pow of 2.
+ * - qedi, qla4xxx and be2iscsi ignore or pass through the libiscsi itt.
+ */
+#define ISCSI_ITT_MASK 0x3fff
+#define ISCSI_TOTAL_CMDS_MAX 8192
+/* bit 14 is set for MGMT tasks and cleared for scsi cmds */
+#define ISCSI_TASK_TYPE_MGMT 0x2000
+#define ISCSI_TOTAL_CMDS_MIN (ISCSI_INFLIGHT_MGMT_MAX + 1)
#define ISCSI_AGE_SHIFT 28
#define ISCSI_AGE_MASK 0xf
@@ -331,13 +350,10 @@ struct iscsi_session {
spinlock_t frwd_lock; /* protects queued_cmdsn, *
* cmdsn, suspend_bit, *
* leadconn, _stage, *
- * tmf_state and session *
- * resources: *
- * - cmdpool kfifo_out , *
- * - mgmtpool, queues */
+ * tmf_state and mgmt *
+ * queues */
spinlock_t back_lock; /* protects cmdsn_exp *
- * cmdsn_max, *
- * cmdpool kfifo_in */
+ * cmdsn_max, mgmt queues */
/*
* frwd_lock must be held when transitioning states, but not needed
* if just checking the state in the scsi-ml or iscsi callouts.
@@ -346,9 +362,9 @@ struct iscsi_session {
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 */
+ int cmds_max; /* Total number of tasks */
+ struct iscsi_task **mgmt_cmds;
+ struct iscsi_pool mgmt_pool; /* mgmt task pool */
void *dd_data; /* LLD private data */
};
--
2.25.1
