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[SCSI] iscsi lib: have lib create work queue for transmitting IO

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We were using the shost work queue which ended up being
a little akward since all iscsi hosts need a thread for
scanning, but only drivers hooked into libiscsi need
a workqueue for transmitting. So this patch moves the
xmit workqueue to the lib.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Mike Christie
2009-03-05 14:46:03 -06:00
committed by James Bottomley
parent 06d25af4ed
commit 32ae763e3f
7 changed files with 48 additions and 16 deletions
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45
drivers/scsi/libiscsi.c
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@@ -76,6 +76,15 @@ static int iscsi_sna_lte(u32 n1, u32 n2)
(n1 > n2 && (n2 - n1 < SNA32_CHECK)));
}
inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
{
struct Scsi_Host *shost = conn->session->host;
struct iscsi_host *ihost = shost_priv(shost);
queue_work(ihost->workq, &conn->xmitwork);
}
EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
void
iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
{
@@ -103,8 +112,7 @@ iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
if (!list_empty(&session->leadconn->xmitqueue) ||
!list_empty(&session->leadconn->mgmtqueue)) {
if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
scsi_queue_work(session->host,
&session->leadconn->xmitwork);
iscsi_conn_queue_work(session->leadconn);
}
}
}
@@ -586,7 +594,7 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
goto free_task;
} else
scsi_queue_work(conn->session->host, &conn->xmitwork);
iscsi_conn_queue_work(conn);
return task;
@@ -1160,7 +1168,7 @@ void iscsi_requeue_task(struct iscsi_task *task)
struct iscsi_conn *conn = task->conn;
list_move_tail(&task->running, &conn->requeue);
scsi_queue_work(conn->session->host, &conn->xmitwork);
iscsi_conn_queue_work(conn);
}
EXPORT_SYMBOL_GPL(iscsi_requeue_task);
@@ -1413,7 +1421,7 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
goto prepd_reject;
}
} else
scsi_queue_work(session->host, &conn->xmitwork);
iscsi_conn_queue_work(conn);
session->queued_cmdsn++;
spin_unlock(&session->lock);
@@ -1631,9 +1639,12 @@ static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
void iscsi_suspend_tx(struct iscsi_conn *conn)
{
struct Scsi_Host *shost = conn->session->host;
struct iscsi_host *ihost = shost_priv(shost);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
scsi_flush_work(conn->session->host);
flush_workqueue(ihost->workq);
}
EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
@@ -1641,7 +1652,7 @@ static void iscsi_start_tx(struct iscsi_conn *conn)
{
clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
scsi_queue_work(conn->session->host, &conn->xmitwork);
iscsi_conn_queue_work(conn);
}
static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
@@ -2046,12 +2057,14 @@ EXPORT_SYMBOL_GPL(iscsi_host_add);
* @sht: scsi host template
* @dd_data_size: driver host data size
* @qdepth: default device queue depth
* @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
*
* This should be called by partial offload and software iscsi drivers.
* To access the driver specific memory use the iscsi_host_priv() macro.
*/
struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
int dd_data_size, uint16_t qdepth)
int dd_data_size, uint16_t qdepth,
bool xmit_can_sleep)
{
struct Scsi_Host *shost;
struct iscsi_host *ihost;
@@ -2063,13 +2076,25 @@ struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
if (qdepth == 0)
qdepth = ISCSI_DEF_CMD_PER_LUN;
shost->cmd_per_lun = qdepth;
ihost = shost_priv(shost);
if (xmit_can_sleep) {
snprintf(ihost->workq_name, sizeof(ihost->workq_name),
"iscsi_q_%d", shost->host_no);
ihost->workq = create_singlethread_workqueue(ihost->workq_name);
if (!ihost->workq)
goto free_host;
}
spin_lock_init(&ihost->lock);
ihost->state = ISCSI_HOST_SETUP;
ihost->num_sessions = 0;
init_waitqueue_head(&ihost->session_removal_wq);
return shost;
free_host:
scsi_host_put(shost);
return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_host_alloc);
@@ -2101,6 +2126,8 @@ void iscsi_host_remove(struct Scsi_Host *shost)
flush_signals(current);
scsi_remove_host(shost);
if (ihost->workq)
destroy_workqueue(ihost->workq);
}
EXPORT_SYMBOL_GPL(iscsi_host_remove);