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[SCSI] libiscsi, iser, tcp: remove recv_lock

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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>
This commit is contained in:
Mike Christie
2008-05-21 15:54:18 -05:00
committed by James Bottomley
parent 3cf7b233ff
commit 913e5bf435
6 changed files with 144 additions and 117 deletions
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152
drivers/scsi/libiscsi.c
View File

@@ -362,10 +362,11 @@ static void iscsi_complete_command(struct iscsi_task *task)
}
}
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 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
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 {
@@ -696,6 +701,31 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
return 0;
}
/**
* 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
@@ -707,8 +737,8 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
* 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 @@ static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
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 @@ static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
__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 @@ recv_pdu:
__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 @@ EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
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 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
(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 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
"%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)
return NULL;
task = session->cmds[i];
if (!task->sc)
return NULL;
if (task->sc->SCp.phase != session->age)
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;
}
return task;
}
@@ -1620,16 +1654,20 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
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 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
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;
@@ -2256,17 +2292,6 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
return;
}
/*
* 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
@@ -2283,11 +2308,6 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
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