[SCSI] libiscsi, iser, tcp: remove recv_lock
The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.
We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.
This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index c723e60..9c267b4 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -362,10 +362,11 @@
}
}
-static void __iscsi_get_task(struct iscsi_task *task)
+void __iscsi_get_task(struct iscsi_task *task)
{
atomic_inc(&task->refcount);
}
+EXPORT_SYMBOL_GPL(__iscsi_get_task);
static void __iscsi_put_task(struct iscsi_task *task)
{
@@ -403,9 +404,13 @@
conn->session->queued_cmdsn--;
else
conn->session->tt->cleanup_task(conn, task);
+ /*
+ * Check if cleanup_task dropped the lock and the command completed,
+ */
+ if (!task->sc)
+ return;
sc->result = err;
-
if (!scsi_bidi_cmnd(sc))
scsi_set_resid(sc, scsi_bufflen(sc));
else {
@@ -697,6 +702,31 @@
}
/**
+ * iscsi_itt_to_task - look up task by itt
+ * @conn: iscsi connection
+ * @itt: itt
+ *
+ * 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.
+ */
+static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
+{
+ struct iscsi_session *session = conn->session;
+ uint32_t i;
+
+ if (itt == RESERVED_ITT)
+ return NULL;
+
+ i = get_itt(itt);
+ if (i >= session->cmds_max)
+ return NULL;
+
+ return session->cmds[i];
+}
+
+/**
* __iscsi_complete_pdu - complete pdu
* @conn: iscsi conn
* @hdr: iscsi header
@@ -707,8 +737,8 @@
* queuecommand or send generic. session lock must be held and verify
* itt must have been called.
*/
-static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
- char *data, int datalen)
+int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+ char *data, int datalen)
{
struct iscsi_session *session = conn->session;
int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
@@ -758,22 +788,36 @@
goto out;
}
- task = session->cmds[itt];
switch(opcode) {
case ISCSI_OP_SCSI_CMD_RSP:
- if (!task->sc) {
- rc = ISCSI_ERR_NO_SCSI_CMD;
- break;
- }
- BUG_ON((void*)task != task->sc->SCp.ptr);
+ case ISCSI_OP_SCSI_DATA_IN:
+ task = iscsi_itt_to_ctask(conn, hdr->itt);
+ if (!task)
+ return ISCSI_ERR_BAD_ITT;
+ break;
+ case ISCSI_OP_R2T:
+ /*
+ * LLD handles R2Ts if they need to.
+ */
+ return 0;
+ case ISCSI_OP_LOGOUT_RSP:
+ case ISCSI_OP_LOGIN_RSP:
+ case ISCSI_OP_TEXT_RSP:
+ case ISCSI_OP_SCSI_TMFUNC_RSP:
+ case ISCSI_OP_NOOP_IN:
+ task = iscsi_itt_to_task(conn, hdr->itt);
+ if (!task)
+ return ISCSI_ERR_BAD_ITT;
+ break;
+ default:
+ return ISCSI_ERR_BAD_OPCODE;
+ }
+
+ switch(opcode) {
+ case ISCSI_OP_SCSI_CMD_RSP:
iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
break;
case ISCSI_OP_SCSI_DATA_IN:
- if (!task->sc) {
- rc = ISCSI_ERR_NO_SCSI_CMD;
- break;
- }
- BUG_ON((void*)task != task->sc->SCp.ptr);
if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
conn->scsirsp_pdus_cnt++;
iscsi_update_cmdsn(session,
@@ -781,9 +825,6 @@
__iscsi_put_task(task);
}
break;
- case ISCSI_OP_R2T:
- /* LLD handles this for now */
- break;
case ISCSI_OP_LOGOUT_RSP:
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
if (datalen) {
@@ -841,6 +882,7 @@
__iscsi_put_task(task);
return rc;
}
+EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, int datalen)
@@ -857,7 +899,6 @@
int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
{
struct iscsi_session *session = conn->session;
- struct iscsi_task *task;
uint32_t i;
if (itt == RESERVED_ITT)
@@ -867,8 +908,7 @@
(session->age << ISCSI_AGE_SHIFT)) {
iscsi_conn_printk(KERN_ERR, conn,
"received itt %x expected session age (%x)\n",
- (__force u32)itt,
- session->age & ISCSI_AGE_MASK);
+ (__force u32)itt, session->age);
return ISCSI_ERR_BAD_ITT;
}
@@ -879,42 +919,36 @@
"%u.\n", i, session->cmds_max);
return ISCSI_ERR_BAD_ITT;
}
-
- task = session->cmds[i];
- if (task->sc && task->sc->SCp.phase != session->age) {
- iscsi_conn_printk(KERN_ERR, conn,
- "iscsi: task's session age %d, "
- "expected %d\n", task->sc->SCp.phase,
- session->age);
- return ISCSI_ERR_SESSION_FAILED;
- }
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_verify_itt);
-struct iscsi_task *
-iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
+/**
+ * iscsi_itt_to_ctask - look up ctask by itt
+ * @conn: iscsi connection
+ * @itt: itt
+ *
+ * This should be used for cmd tasks.
+ *
+ * The session lock must be held.
+ */
+struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
{
- struct iscsi_session *session = conn->session;
struct iscsi_task *task;
- uint32_t i;
if (iscsi_verify_itt(conn, itt))
return NULL;
- if (itt == RESERVED_ITT)
+ task = iscsi_itt_to_task(conn, itt);
+ if (!task || !task->sc)
return NULL;
- i = get_itt(itt);
- if (i >= session->cmds_max)
+ if (task->sc->SCp.phase != conn->session->age) {
+ iscsi_session_printk(KERN_ERR, conn->session,
+ "task's session age %d, expected %d\n",
+ task->sc->SCp.phase, conn->session->age);
return NULL;
-
- task = session->cmds[i];
- if (!task->sc)
- return NULL;
-
- if (task->sc->SCp.phase != session->age)
- return NULL;
+ }
return task;
}
@@ -1620,16 +1654,20 @@
switch (conn->tmf_state) {
case TMF_SUCCESS:
spin_unlock_bh(&session->lock);
+ /*
+ * stop tx side incase the target had sent a abort rsp but
+ * the initiator was still writing out data.
+ */
iscsi_suspend_tx(conn);
/*
- * clean up task if aborted. grab the recv lock as a writer
+ * we do not stop the recv side because targets have been
+ * good and have never sent us a successful tmf response
+ * then sent more data for the cmd.
*/
- write_lock_bh(conn->recv_lock);
spin_lock(&session->lock);
fail_command(conn, task, DID_ABORT << 16);
conn->tmf_state = TMF_INITIAL;
spin_unlock(&session->lock);
- write_unlock_bh(conn->recv_lock);
iscsi_start_tx(conn);
goto success_unlocked;
case TMF_TIMEDOUT:
@@ -1729,13 +1767,11 @@
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
- /* need to grab the recv lock then session lock */
- write_lock_bh(conn->recv_lock);
+
spin_lock(&session->lock);
fail_all_commands(conn, sc->device->lun, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
spin_unlock(&session->lock);
- write_unlock_bh(conn->recv_lock);
iscsi_start_tx(conn);
goto done;
@@ -2257,17 +2293,6 @@
}
/*
- * The LLD either freed/unset the lock on us, or userspace called
- * stop but did not create a proper connection (connection was never
- * bound or it was unbound then stop was called).
- */
- if (!conn->recv_lock) {
- spin_unlock_bh(&session->lock);
- mutex_unlock(&session->eh_mutex);
- return;
- }
-
- /*
* When this is called for the in_login state, we only want to clean
* up the login task and connection. We do not need to block and set
* the recovery state again
@@ -2283,11 +2308,6 @@
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
-
- write_lock_bh(conn->recv_lock);
- set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
- write_unlock_bh(conn->recv_lock);
-
/*
* for connection level recovery we should not calculate
* header digest. conn->hdr_size used for optimization