[SCSI] libiscsi: Reduce locking contention in fast path
Replace the session lock with two locks, a forward lock and
a backwards lock named frwd_lock and back_lock respectively.
The forward lock protects resources that change while sending a
request to the target, such as cmdsn, queued_cmdsn, and allocating
task from the commands' pool with kfifo_out.
The backward lock protects resources that change while processing
a response or in error path, such as cmdsn_exp, cmdsn_max, and
returning tasks to the commands' pool with kfifo_in.
Under a steady state fast-path situation, that is when one
or more processes/threads submit IO to an iscsi device and
a single kernel upcall (e.g softirq) is dealing with processing
of responses without errors, this patch eliminates the contention
between the queuecommand()/request response/scsi_done() flows
associated with iscsi sessions.
Between the forward and the backward locks exists a strict locking
hierarchy. The mutual exclusion zone protected by the forward lock can
enclose the mutual exclusion zone protected by the backward lock but not
vice versa.
For example, in iscsi_conn_teardown or in iscsi_xmit_data when there is
a failure and __iscsi_put_task is called, the backward lock is taken while
the forward lock is still taken. On the other hand, if in the RX path a nop
is to be sent, for example in iscsi_handle_reject or __iscsi_complete_pdu
than the forward lock is released and the backward lock is taken for the
duration of iscsi_send_nopout, later the backward lock is released and the
forward lock is retaken.
libiscsi_tcp uses two kernel fifos the r2t pool and the r2t queue.
The insertion and deletion from these queues didn't corespond to the
assumption taken by the new forward/backwards session locking paradigm.
That is, in iscsi_tcp_clenup_task which belongs to the RX (backwards)
path, r2t is taken out from r2t queue and inserted to the r2t pool.
In iscsi_tcp_get_curr_r2t which belong to the TX (forward) path, r2t
is also inserted to the r2t pool and another r2t is pulled from r2t
queue.
Only in iscsi_tcp_r2t_rsp which is called in the RX path but can requeue
to the TX path, r2t is taken from the r2t pool and inserted to the r2t
queue.
In order to cope with this situation, two spin locks were added,
pool2queue and queue2pool. The former protects extracting from the
r2t pool and inserting to the r2t queue, and the later protects the
extracing from the r2t queue and inserting to the r2t pool.
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
[minor fix up to apply cleanly and compile fix]
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index 3cd4693..9be818f 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -233,20 +233,20 @@
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (!aborted_task || !aborted_task->sc) {
/* we raced */
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return SUCCESS;
}
aborted_io_task = aborted_task->dd_data;
if (!aborted_io_task->scsi_cmnd) {
/* raced or invalid command */
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return SUCCESS;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
/* Invalidate WRB Posted for this Task */
AMAP_SET_BITS(struct amap_iscsi_wrb, invld,
aborted_io_task->pwrb_handle->pwrb,
@@ -311,9 +311,9 @@
/* invalidate iocbs */
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return FAILED;
}
conn = session->leadconn;
@@ -342,7 +342,7 @@
num_invalidate++;
inv_tbl++;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
inv_tbl = phba->inv_tbl;
nonemb_cmd.va = pci_alloc_consistent(phba->ctrl.pdev,
@@ -1185,9 +1185,9 @@
return 1;
}
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->back_lock);
__iscsi_complete_pdu(conn, (struct iscsi_hdr *)ppdu, pbuffer, buf_len);
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->back_lock);
return 0;
}
@@ -1606,7 +1606,7 @@
pwrb = pwrb_handle->pwrb;
type = ((struct beiscsi_io_task *)task->dd_data)->wrb_type;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->back_lock);
switch (type) {
case HWH_TYPE_IO:
case HWH_TYPE_IO_RD:
@@ -1645,7 +1645,7 @@
break;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->back_lock);
}
static struct list_head *hwi_get_async_busy_list(struct hwi_async_pdu_context
@@ -4693,9 +4693,9 @@
* login/startup related tasks.
*/
beiscsi_conn->login_in_progress = 0;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->back_lock);
beiscsi_cleanup_task(task);
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->back_lock);
pwrb_handle = alloc_wrb_handle(phba, beiscsi_conn->beiscsi_conn_cid);
diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c
index e4cf23d..da9cf04 100644
--- a/drivers/scsi/bnx2i/bnx2i_hwi.c
+++ b/drivers/scsi/bnx2i/bnx2i_hwi.c
@@ -1361,7 +1361,7 @@
u32 datalen = 0;
resp_cqe = (struct bnx2i_cmd_response *)cqe;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->back_lock);
task = iscsi_itt_to_task(conn,
resp_cqe->itt & ISCSI_CMD_RESPONSE_INDEX);
if (!task)
@@ -1432,7 +1432,7 @@
__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr,
conn->data, datalen);
fail:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->back_lock);
return 0;
}
@@ -1457,7 +1457,7 @@
int pad_len;
login = (struct bnx2i_login_response *) cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(conn,
login->itt & ISCSI_LOGIN_RESPONSE_INDEX);
if (!task)
@@ -1500,7 +1500,7 @@
bnx2i_conn->gen_pdu.resp_buf,
bnx2i_conn->gen_pdu.resp_wr_ptr - bnx2i_conn->gen_pdu.resp_buf);
done:
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
return 0;
}
@@ -1525,7 +1525,7 @@
int pad_len;
text = (struct bnx2i_text_response *) cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(conn, text->itt & ISCSI_LOGIN_RESPONSE_INDEX);
if (!task)
goto done;
@@ -1561,7 +1561,7 @@
bnx2i_conn->gen_pdu.resp_wr_ptr -
bnx2i_conn->gen_pdu.resp_buf);
done:
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
return 0;
}
@@ -1584,7 +1584,7 @@
struct iscsi_tm_rsp *resp_hdr;
tmf_cqe = (struct bnx2i_tmf_response *)cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(conn,
tmf_cqe->itt & ISCSI_TMF_RESPONSE_INDEX);
if (!task)
@@ -1600,7 +1600,7 @@
__iscsi_complete_pdu(conn, (struct iscsi_hdr *)resp_hdr, NULL, 0);
done:
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
return 0;
}
@@ -1623,7 +1623,7 @@
struct iscsi_logout_rsp *resp_hdr;
logout = (struct bnx2i_logout_response *) cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(conn,
logout->itt & ISCSI_LOGOUT_RESPONSE_INDEX);
if (!task)
@@ -1647,7 +1647,7 @@
bnx2i_conn->ep->state = EP_STATE_LOGOUT_RESP_RCVD;
done:
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
return 0;
}
@@ -1668,12 +1668,12 @@
struct iscsi_task *task;
nop_in = (struct bnx2i_nop_in_msg *)cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(conn,
nop_in->itt & ISCSI_NOP_IN_MSG_INDEX);
if (task)
__iscsi_put_task(task);
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
}
/**
@@ -1712,7 +1712,7 @@
nop_in = (struct bnx2i_nop_in_msg *)cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
hdr = (struct iscsi_nopin *)&bnx2i_conn->gen_pdu.resp_hdr;
memset(hdr, 0, sizeof(struct iscsi_hdr));
hdr->opcode = nop_in->op_code;
@@ -1738,7 +1738,7 @@
}
done:
__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr, NULL, 0);
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
return tgt_async_nop;
}
@@ -1771,7 +1771,7 @@
return;
}
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
resp_hdr = (struct iscsi_async *) &bnx2i_conn->gen_pdu.resp_hdr;
memset(resp_hdr, 0, sizeof(struct iscsi_hdr));
resp_hdr->opcode = async_cqe->op_code;
@@ -1790,7 +1790,7 @@
__iscsi_complete_pdu(bnx2i_conn->cls_conn->dd_data,
(struct iscsi_hdr *)resp_hdr, NULL, 0);
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
}
@@ -1817,7 +1817,7 @@
} else
bnx2i_unsol_pdu_adjust_rq(bnx2i_conn);
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
hdr = (struct iscsi_reject *) &bnx2i_conn->gen_pdu.resp_hdr;
memset(hdr, 0, sizeof(struct iscsi_hdr));
hdr->opcode = reject->op_code;
@@ -1828,7 +1828,7 @@
hdr->ffffffff = cpu_to_be32(RESERVED_ITT);
__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr, conn->data,
reject->data_length);
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
}
/**
@@ -1848,13 +1848,13 @@
struct iscsi_task *task;
cmd_clean_rsp = (struct bnx2i_cleanup_response *)cqe;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(conn,
cmd_clean_rsp->itt & ISCSI_CLEANUP_RESPONSE_INDEX);
if (!task)
printk(KERN_ALERT "bnx2i: cmd clean ITT %x not active\n",
cmd_clean_rsp->itt & ISCSI_CLEANUP_RESPONSE_INDEX);
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
complete(&bnx2i_conn->cmd_cleanup_cmpl);
}
@@ -1921,11 +1921,11 @@
int rc = 0;
int cpu;
- spin_lock(&session->lock);
+ spin_lock(&session->back_lock);
task = iscsi_itt_to_task(bnx2i_conn->cls_conn->dd_data,
cqe->itt & ISCSI_CMD_RESPONSE_INDEX);
if (!task || !task->sc) {
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
return -EINVAL;
}
sc = task->sc;
@@ -1935,7 +1935,7 @@
else
cpu = sc->request->cpu;
- spin_unlock(&session->lock);
+ spin_unlock(&session->back_lock);
p = &per_cpu(bnx2i_percpu, cpu);
spin_lock(&p->p_work_lock);
diff --git a/drivers/scsi/bnx2i/bnx2i_iscsi.c b/drivers/scsi/bnx2i/bnx2i_iscsi.c
index 854dad7..c00642f 100644
--- a/drivers/scsi/bnx2i/bnx2i_iscsi.c
+++ b/drivers/scsi/bnx2i/bnx2i_iscsi.c
@@ -1169,10 +1169,10 @@
if (task->state == ISCSI_TASK_ABRT_TMF) {
bnx2i_send_cmd_cleanup_req(hba, task->dd_data);
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->back_lock);
wait_for_completion_timeout(&bnx2i_conn->cmd_cleanup_cmpl,
msecs_to_jiffies(ISCSI_CMD_CLEANUP_TIMEOUT));
- spin_lock_bh(&conn->session->lock);
+ spin_lock_bh(&conn->session->back_lock);
}
bnx2i_iscsi_unmap_sg_list(task->dd_data);
}
@@ -2059,7 +2059,7 @@
goto out;
if (session) {
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (bnx2i_ep->state != EP_STATE_TCP_FIN_RCVD) {
if (session->state == ISCSI_STATE_LOGGING_OUT) {
if (bnx2i_ep->state == EP_STATE_LOGOUT_SENT) {
@@ -2075,7 +2075,7 @@
} else
close = 1;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
}
bnx2i_ep->state = EP_STATE_DISCONN_START;
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index add6d15..12b3512 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -593,9 +593,9 @@
iscsi_sw_tcp_conn_restore_callbacks(conn);
sock_put(sock->sk);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
tcp_sw_conn->sock = NULL;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
sockfd_put(sock);
}
@@ -663,10 +663,10 @@
if (err)
goto free_socket;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
/* bind iSCSI connection and socket */
tcp_sw_conn->sock = sock;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
/* setup Socket parameters */
sk = sock->sk;
@@ -726,14 +726,14 @@
switch(param) {
case ISCSI_PARAM_CONN_PORT:
case ISCSI_PARAM_CONN_ADDRESS:
- spin_lock_bh(&conn->session->lock);
+ spin_lock_bh(&conn->session->frwd_lock);
if (!tcp_sw_conn || !tcp_sw_conn->sock) {
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
return -ENOTCONN;
}
rc = kernel_getpeername(tcp_sw_conn->sock,
(struct sockaddr *)&addr, &len);
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
if (rc)
return rc;
@@ -759,23 +759,23 @@
switch (param) {
case ISCSI_HOST_PARAM_IPADDRESS:
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
conn = session->leadconn;
if (!conn) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return -ENOTCONN;
}
tcp_conn = conn->dd_data;
tcp_sw_conn = tcp_conn->dd_data;
if (!tcp_sw_conn->sock) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return -ENOTCONN;
}
rc = kernel_getsockname(tcp_sw_conn->sock,
(struct sockaddr *)&addr, &len);
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
if (rc)
return rc;
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index cd330c0..8738b98 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -481,7 +481,7 @@
* iscsi_free_task - free a task
* @task: iscsi cmd task
*
- * Must be called with session lock.
+ * Must be called with session back_lock.
* This function returns the scsi command to scsi-ml or cleans
* up mgmt tasks then returns the task to the pool.
*/
@@ -535,9 +535,10 @@
{
struct iscsi_session *session = task->conn->session;
- spin_lock_bh(&session->lock);
+ /* regular RX path uses back_lock */
+ spin_lock_bh(&session->back_lock);
__iscsi_put_task(task);
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->back_lock);
}
EXPORT_SYMBOL_GPL(iscsi_put_task);
@@ -546,7 +547,7 @@
* @task: iscsi cmd task
* @state: state to complete task with
*
- * Must be called with session lock.
+ * Must be called with session back_lock.
*/
static void iscsi_complete_task(struct iscsi_task *task, int state)
{
@@ -585,7 +586,7 @@
* This is used when drivers do not need or cannot perform
* lower level pdu processing.
*
- * Called with session lock
+ * Called with session back_lock
*/
void iscsi_complete_scsi_task(struct iscsi_task *task,
uint32_t exp_cmdsn, uint32_t max_cmdsn)
@@ -602,7 +603,7 @@
/*
- * session lock must be held and if not called for a task that is
+ * session back_lock must be held and if not called for a task that is
* still pending or from the xmit thread, then xmit thread must
* be suspended.
*/
@@ -642,7 +643,10 @@
scsi_in(sc)->resid = scsi_in(sc)->length;
}
+ /* regular RX path uses back_lock */
+ spin_lock_bh(&conn->session->back_lock);
iscsi_complete_task(task, state);
+ spin_unlock_bh(&conn->session->back_lock);
}
static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
@@ -780,7 +784,10 @@
return task;
free_task:
+ /* regular RX path uses back_lock */
+ spin_lock_bh(&session->back_lock);
__iscsi_put_task(task);
+ spin_unlock_bh(&session->back_lock);
return NULL;
}
@@ -791,10 +798,10 @@
struct iscsi_session *session = conn->session;
int err = 0;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
err = -EPERM;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return err;
}
EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
@@ -1031,14 +1038,19 @@
if (opcode != ISCSI_OP_NOOP_OUT)
return 0;
- if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
+ if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
/*
* nop-out in response to target's nop-out rejected.
* Just resend.
*/
+ /* In RX path we are under back lock */
+ spin_unlock(&conn->session->back_lock);
+ spin_lock(&conn->session->frwd_lock);
iscsi_send_nopout(conn,
(struct iscsi_nopin*)&rejected_pdu);
- else {
+ spin_unlock(&conn->session->frwd_lock);
+ spin_lock(&conn->session->back_lock);
+ } else {
struct iscsi_task *task;
/*
* Our nop as ping got dropped. We know the target
@@ -1074,7 +1086,7 @@
* This should be used for mgmt tasks like login and nops, or if
* the LDD's itt space does not include the session age.
*
- * The session lock must be held.
+ * The session back_lock must be held.
*/
struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
{
@@ -1103,7 +1115,7 @@
* @datalen: len of data buffer
*
* Completes pdu processing by freeing any resources allocated at
- * queuecommand or send generic. session lock must be held and verify
+ * queuecommand or send generic. session back_lock must be held and verify
* itt must have been called.
*/
int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
@@ -1140,7 +1152,12 @@
if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
break;
+ /* In RX path we are under back lock */
+ spin_unlock(&session->back_lock);
+ spin_lock(&session->frwd_lock);
iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
+ spin_unlock(&session->frwd_lock);
+ spin_lock(&session->back_lock);
break;
case ISCSI_OP_REJECT:
rc = iscsi_handle_reject(conn, hdr, data, datalen);
@@ -1247,9 +1264,9 @@
{
int rc;
- spin_lock(&conn->session->lock);
+ spin_lock(&conn->session->back_lock);
rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
- spin_unlock(&conn->session->lock);
+ spin_unlock(&conn->session->back_lock);
return rc;
}
EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
@@ -1293,7 +1310,7 @@
*
* This should be used for cmd tasks.
*
- * The session lock must be held.
+ * The session back_lock must be held.
*/
struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
{
@@ -1323,15 +1340,15 @@
struct iscsi_conn *conn;
struct device *dev;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
conn = session->leadconn;
if (session->state == ISCSI_STATE_TERMINATE || !conn) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return;
}
dev = get_device(&conn->cls_conn->dev);
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
if (!dev)
return;
/*
@@ -1351,15 +1368,15 @@
{
struct iscsi_session *session = conn->session;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (session->state == ISCSI_STATE_FAILED) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return;
}
if (conn->stop_stage == 0)
session->state = ISCSI_STATE_FAILED;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
@@ -1393,15 +1410,18 @@
return -ENODATA;
__iscsi_get_task(task);
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
rc = conn->session->tt->xmit_task(task);
- spin_lock_bh(&conn->session->lock);
+ spin_lock_bh(&conn->session->frwd_lock);
if (!rc) {
/* done with this task */
task->last_xfer = jiffies;
conn->task = NULL;
}
+ /* regular RX path uses back_lock */
+ spin_lock_bh(&conn->session->back_lock);
__iscsi_put_task(task);
+ spin_unlock_bh(&conn->session->back_lock);
return rc;
}
@@ -1410,7 +1430,7 @@
* @task: task to requeue
*
* LLDs that need to run a task from the session workqueue should call
- * this. The session lock must be held. This should only be called
+ * this. The session frwd_lock must be held. This should only be called
* by software drivers.
*/
void iscsi_requeue_task(struct iscsi_task *task)
@@ -1441,10 +1461,10 @@
struct iscsi_task *task;
int rc = 0;
- spin_lock_bh(&conn->session->lock);
+ spin_lock_bh(&conn->session->frwd_lock);
if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
return -ENODATA;
}
@@ -1465,7 +1485,10 @@
struct iscsi_task, running);
list_del_init(&conn->task->running);
if (iscsi_prep_mgmt_task(conn, conn->task)) {
+ /* regular RX path uses back_lock */
+ spin_lock_bh(&conn->session->back_lock);
__iscsi_put_task(conn->task);
+ spin_unlock_bh(&conn->session->back_lock);
conn->task = NULL;
continue;
}
@@ -1527,11 +1550,11 @@
if (!list_empty(&conn->mgmtqueue))
goto check_mgmt;
}
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
return -ENODATA;
done:
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
return rc;
}
@@ -1600,7 +1623,7 @@
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
reason = iscsi_session_chkready(cls_session);
if (reason) {
@@ -1686,13 +1709,13 @@
}
session->queued_cmdsn++;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
return 0;
prepd_reject:
iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
reject:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
sc->cmnd[0], reason);
return SCSI_MLQUEUE_TARGET_BUSY;
@@ -1700,7 +1723,7 @@
prepd_fault:
iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
fault:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
sc->cmnd[0], reason);
if (!scsi_bidi_cmnd(sc))
@@ -1748,14 +1771,14 @@
struct iscsi_conn *conn = (struct iscsi_conn *)data;
struct iscsi_session *session = conn->session;
- spin_lock(&session->lock);
+ spin_lock(&session->frwd_lock);
if (conn->tmf_state == TMF_QUEUED) {
conn->tmf_state = TMF_TIMEDOUT;
ISCSI_DBG_EH(session, "tmf timedout\n");
/* unblock eh_abort() */
wake_up(&conn->ehwait);
}
- spin_unlock(&session->lock);
+ spin_unlock(&session->frwd_lock);
}
static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
@@ -1768,10 +1791,10 @@
task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
NULL, 0);
if (!task) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
return -EPERM;
}
conn->tmfcmd_pdus_cnt++;
@@ -1781,7 +1804,7 @@
add_timer(&conn->tmf_timer);
ISCSI_DBG_EH(session, "tmf set timeout\n");
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
/*
@@ -1800,7 +1823,7 @@
del_timer_sync(&conn->tmf_timer);
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
/* if the session drops it will clean up the task */
if (age != session->age ||
session->state != ISCSI_STATE_LOGGED_IN)
@@ -1837,7 +1860,7 @@
* iscsi_suspend_queue - suspend iscsi_queuecommand
* @conn: iscsi conn to stop queueing IO on
*
- * This grabs the session lock to make sure no one is in
+ * This grabs the session frwd_lock to make sure no one is in
* xmit_task/queuecommand, and then sets suspend to prevent
* new commands from being queued. This only needs to be called
* by offload drivers that need to sync a path like ep disconnect
@@ -1846,9 +1869,9 @@
*/
void iscsi_suspend_queue(struct iscsi_conn *conn)
{
- spin_lock_bh(&conn->session->lock);
+ spin_lock_bh(&conn->session->frwd_lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
- spin_unlock_bh(&conn->session->lock);
+ spin_unlock_bh(&conn->session->frwd_lock);
}
EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
@@ -1907,7 +1930,7 @@
ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
- spin_lock(&session->lock);
+ spin_lock(&session->frwd_lock);
task = (struct iscsi_task *)sc->SCp.ptr;
if (!task) {
/*
@@ -2021,7 +2044,7 @@
done:
if (task)
task->last_timeout = jiffies;
- spin_unlock(&session->lock);
+ spin_unlock(&session->frwd_lock);
ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
"timer reset" : "nh");
return rc;
@@ -2033,7 +2056,7 @@
struct iscsi_session *session = conn->session;
unsigned long recv_timeout, next_timeout = 0, last_recv;
- spin_lock(&session->lock);
+ spin_lock(&session->frwd_lock);
if (session->state != ISCSI_STATE_LOGGED_IN)
goto done;
@@ -2050,7 +2073,7 @@
"last ping %lu, now %lu\n",
conn->ping_timeout, conn->recv_timeout,
last_recv, conn->last_ping, jiffies);
- spin_unlock(&session->lock);
+ spin_unlock(&session->frwd_lock);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return;
}
@@ -2066,7 +2089,7 @@
ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
mod_timer(&conn->transport_timer, next_timeout);
done:
- spin_unlock(&session->lock);
+ spin_unlock(&session->frwd_lock);
}
static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
@@ -2096,7 +2119,7 @@
ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
/*
* if session was ISCSI_STATE_IN_RECOVERY then we may not have
* got the command.
@@ -2104,7 +2127,7 @@
if (!sc->SCp.ptr) {
ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
"it completed.\n");
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
}
@@ -2115,7 +2138,7 @@
*/
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
sc->SCp.phase != session->age) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
ISCSI_DBG_EH(session, "failing abort due to dropped "
"session.\n");
@@ -2156,7 +2179,7 @@
switch (conn->tmf_state) {
case TMF_SUCCESS:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
/*
* stop tx side incase the target had sent a abort rsp but
* the initiator was still writing out data.
@@ -2167,15 +2190,15 @@
* good and have never sent us a successful tmf response
* then sent more data for the cmd.
*/
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
fail_scsi_task(task, DID_ABORT);
conn->tmf_state = TMF_INITIAL;
memset(hdr, 0, sizeof(*hdr));
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_start_tx(conn);
goto success_unlocked;
case TMF_TIMEDOUT:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
goto failed_unlocked;
case TMF_NOT_FOUND:
@@ -2194,7 +2217,7 @@
}
success:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
success_unlocked:
ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
sc, task->itt);
@@ -2202,7 +2225,7 @@
return SUCCESS;
failed:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
failed_unlocked:
ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
task ? task->itt : 0);
@@ -2235,7 +2258,7 @@
ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
/*
* Just check if we are not logged in. We cannot check for
* the phase because the reset could come from a ioctl.
@@ -2262,7 +2285,7 @@
case TMF_SUCCESS:
break;
case TMF_TIMEDOUT:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
goto done;
default:
@@ -2271,21 +2294,21 @@
}
rc = SUCCESS;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_suspend_tx(conn);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
memset(hdr, 0, sizeof(*hdr));
fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_start_tx(conn);
goto done;
unlock:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
done:
ISCSI_DBG_EH(session, "dev reset result = %s\n",
rc == SUCCESS ? "SUCCESS" : "FAILED");
@@ -2298,13 +2321,13 @@
{
struct iscsi_session *session = cls_session->dd_data;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (session->state != ISCSI_STATE_LOGGED_IN) {
session->state = ISCSI_STATE_RECOVERY_FAILED;
if (session->leadconn)
wake_up(&session->leadconn->ehwait);
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
}
EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
@@ -2326,19 +2349,19 @@
conn = session->leadconn;
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (session->state == ISCSI_STATE_TERMINATE) {
failed:
ISCSI_DBG_EH(session,
"failing session reset: Could not log back into "
"%s, %s [age %d]\n", session->targetname,
conn->persistent_address, session->age);
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
return FAILED;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
/*
* we drop the lock here but the leadconn cannot be destoyed while
@@ -2355,14 +2378,14 @@
flush_signals(current);
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (session->state == ISCSI_STATE_LOGGED_IN) {
ISCSI_DBG_EH(session,
"session reset succeeded for %s,%s\n",
session->targetname, conn->persistent_address);
} else
goto failed;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
}
@@ -2398,7 +2421,7 @@
session->targetname);
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
/*
* Just check if we are not logged in. We cannot check for
* the phase because the reset could come from a ioctl.
@@ -2425,7 +2448,7 @@
case TMF_SUCCESS:
break;
case TMF_TIMEDOUT:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
goto done;
default:
@@ -2434,21 +2457,21 @@
}
rc = SUCCESS;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_suspend_tx(conn);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
memset(hdr, 0, sizeof(*hdr));
fail_scsi_tasks(conn, -1, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_start_tx(conn);
goto done;
unlock:
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
done:
ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
rc == SUCCESS ? "SUCCESS" : "FAILED");
@@ -2746,8 +2769,10 @@
session->max_r2t = 1;
session->tt = iscsit;
session->dd_data = cls_session->dd_data + sizeof(*session);
+
mutex_init(&session->eh_mutex);
- spin_lock_init(&session->lock);
+ 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,
@@ -2861,14 +2886,14 @@
INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
/* allocate login_task used for the login/text sequences */
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (!kfifo_out(&session->cmdpool.queue,
(void*)&conn->login_task,
sizeof(void*))) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
goto login_task_alloc_fail;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
data = (char *) __get_free_pages(GFP_KERNEL,
get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
@@ -2905,7 +2930,7 @@
del_timer_sync(&conn->transport_timer);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
if (session->leadconn == conn) {
/*
@@ -2914,7 +2939,7 @@
session->state = ISCSI_STATE_TERMINATE;
wake_up(&conn->ehwait);
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
/*
* Block until all in-progress commands for this connection
@@ -2941,16 +2966,19 @@
/* flush queued up work because we free the connection below */
iscsi_suspend_tx(conn);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
free_pages((unsigned long) conn->data,
get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
kfree(conn->persistent_address);
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*));
+ spin_unlock_bh(&session->back_lock);
if (session->leadconn == conn)
session->leadconn = NULL;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_destroy_conn(cls_conn);
}
@@ -2987,7 +3015,7 @@
conn->ping_timeout = 5;
}
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
conn->c_stage = ISCSI_CONN_STARTED;
session->state = ISCSI_STATE_LOGGED_IN;
session->queued_cmdsn = session->cmdsn;
@@ -3016,7 +3044,7 @@
default:
break;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
iscsi_unblock_session(session->cls_session);
wake_up(&conn->ehwait);
@@ -3055,9 +3083,9 @@
int old_stop_stage;
mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (conn->stop_stage == STOP_CONN_TERM) {
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
return;
}
@@ -3074,14 +3102,14 @@
old_stop_stage = conn->stop_stage;
conn->stop_stage = flag;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
del_timer_sync(&conn->transport_timer);
iscsi_suspend_tx(conn);
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
conn->c_stage = ISCSI_CONN_STOPPED;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
/*
* for connection level recovery we should not calculate
@@ -3102,11 +3130,11 @@
/*
* flush queues.
*/
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
fail_mgmt_tasks(session, conn);
memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
}
@@ -3133,10 +3161,10 @@
struct iscsi_session *session = cls_session->dd_data;
struct iscsi_conn *conn = cls_conn->dd_data;
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&session->frwd_lock);
if (is_leading)
session->leadconn = conn;
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&session->frwd_lock);
/*
* Unblock xmitworker(), Login Phase will pass through.
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 2f738dd..60cb6dc 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -446,7 +446,7 @@
* iscsi_tcp_cleanup_task - free tcp_task resources
* @task: iscsi task
*
- * must be called with session lock
+ * must be called with session back_lock
*/
void iscsi_tcp_cleanup_task(struct iscsi_task *task)
{
@@ -457,6 +457,7 @@
if (!task->sc)
return;
+ spin_lock_bh(&tcp_task->queue2pool);
/* flush task's r2t queues */
while (kfifo_out(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) {
kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t,
@@ -470,6 +471,7 @@
sizeof(void*));
tcp_task->r2t = NULL;
}
+ spin_unlock_bh(&tcp_task->queue2pool);
}
EXPORT_SYMBOL_GPL(iscsi_tcp_cleanup_task);
@@ -577,11 +579,13 @@
return ISCSI_ERR_DATALEN;
}
+ spin_lock(&tcp_task->pool2queue);
rc = kfifo_out(&tcp_task->r2tpool.queue, (void *)&r2t, sizeof(void *));
if (!rc) {
iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
"Target has sent more R2Ts than it "
"negotiated for or driver has leaked.\n");
+ spin_unlock(&tcp_task->pool2queue);
return ISCSI_ERR_PROTO;
}
@@ -596,6 +600,7 @@
tcp_task->exp_datasn = r2tsn + 1;
kfifo_in(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
conn->r2t_pdus_cnt++;
+ spin_unlock(&tcp_task->pool2queue);
iscsi_requeue_task(task);
return 0;
@@ -668,14 +673,14 @@
switch(opcode) {
case ISCSI_OP_SCSI_DATA_IN:
- spin_lock(&conn->session->lock);
+ spin_lock(&conn->session->back_lock);
task = iscsi_itt_to_ctask(conn, hdr->itt);
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else
rc = iscsi_tcp_data_in(conn, task);
if (rc) {
- spin_unlock(&conn->session->lock);
+ spin_unlock(&conn->session->back_lock);
break;
}
@@ -708,11 +713,11 @@
tcp_conn->in.datalen,
iscsi_tcp_process_data_in,
rx_hash);
- spin_unlock(&conn->session->lock);
+ spin_unlock(&conn->session->back_lock);
return rc;
}
rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
- spin_unlock(&conn->session->lock);
+ spin_unlock(&conn->session->back_lock);
break;
case ISCSI_OP_SCSI_CMD_RSP:
if (tcp_conn->in.datalen) {
@@ -722,18 +727,20 @@
rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
case ISCSI_OP_R2T:
- spin_lock(&conn->session->lock);
+ spin_lock(&conn->session->back_lock);
task = iscsi_itt_to_ctask(conn, hdr->itt);
+ spin_unlock(&conn->session->back_lock);
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else if (ahslen)
rc = ISCSI_ERR_AHSLEN;
else if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
task->last_xfer = jiffies;
+ spin_lock(&conn->session->frwd_lock);
rc = iscsi_tcp_r2t_rsp(conn, task);
+ spin_unlock(&conn->session->frwd_lock);
} else
rc = ISCSI_ERR_PROTO;
- spin_unlock(&conn->session->lock);
break;
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
@@ -981,14 +988,13 @@
static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
{
- struct iscsi_session *session = task->conn->session;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_r2t_info *r2t = NULL;
if (iscsi_task_has_unsol_data(task))
r2t = &task->unsol_r2t;
else {
- spin_lock_bh(&session->lock);
+ spin_lock_bh(&tcp_task->queue2pool);
if (tcp_task->r2t) {
r2t = tcp_task->r2t;
/* Continue with this R2T? */
@@ -1010,7 +1016,7 @@
else
r2t = tcp_task->r2t;
}
- spin_unlock_bh(&session->lock);
+ spin_unlock_bh(&tcp_task->queue2pool);
}
return r2t;
@@ -1140,6 +1146,8 @@
iscsi_pool_free(&tcp_task->r2tpool);
goto r2t_alloc_fail;
}
+ spin_lock_init(&tcp_task->pool2queue);
+ spin_lock_init(&tcp_task->queue2pool);
}
return 0;
diff --git a/drivers/scsi/qla4xxx/ql4_isr.c b/drivers/scsi/qla4xxx/ql4_isr.c
index bb34ef8..b1925d1 100644
--- a/drivers/scsi/qla4xxx/ql4_isr.c
+++ b/drivers/scsi/qla4xxx/ql4_isr.c
@@ -385,9 +385,9 @@
cls_conn = ddb_entry->conn;
conn = cls_conn->dd_data;
- spin_lock(&conn->session->lock);
+ spin_lock(&conn->session->back_lock);
task = iscsi_itt_to_task(conn, itt);
- spin_unlock(&conn->session->lock);
+ spin_unlock(&conn->session->back_lock);
if (task == NULL) {
ql4_printk(KERN_ERR, ha, "%s: Task is NULL\n", __func__);
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 309f513..7221a24 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -327,12 +327,19 @@
struct iscsi_transport *tt;
struct Scsi_Host *host;
struct iscsi_conn *leadconn; /* leading connection */
- spinlock_t lock; /* protects session state, *
- * sequence numbers, *
+ /* Between the forward and the backward locks exists a strict locking
+ * hierarchy. The mutual exclusion zone protected by the forward lock
+ * can enclose the mutual exclusion zone protected by the backward lock
+ * but not vice versa.
+ */
+ spinlock_t frwd_lock; /* protects session state, *
+ * cmdsn, queued_cmdsn *
* session resources: *
- * - cmdpool, *
- * - mgmtpool, *
- * - r2tpool */
+ * - cmdpool kfifo_out , *
+ * - mgmtpool, */
+ spinlock_t back_lock; /* protects cmdsn_exp *
+ * cmdsn_max, *
+ * cmdpool kfifo_in */
int state; /* session state */
int age; /* counts session re-opens */
diff --git a/include/scsi/libiscsi_tcp.h b/include/scsi/libiscsi_tcp.h
index 215469a..2a7aa75 100644
--- a/include/scsi/libiscsi_tcp.h
+++ b/include/scsi/libiscsi_tcp.h
@@ -83,6 +83,8 @@
struct iscsi_pool r2tpool;
struct kfifo r2tqueue;
void *dd_data;
+ spinlock_t pool2queue;
+ spinlock_t queue2pool;
};
enum {