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[SCSI] libiscsi: do not block session during logout
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There is not need to block the session during logout. Since
we are going to fail the commands that were blocked just fail them
immediately instead.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Mike Christie authored and James Bottomley committed Jan 12, 2008
1 parent 6320377 commit b3a7ea8
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Showing 5 changed files with 88 additions and 76 deletions.
4 changes: 1 addition & 3 deletions drivers/infiniband/ulp/iser/iser_initiator.c
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Original file line number Diff line number Diff line change
Expand Up @@ -621,9 +621,7 @@ void iser_snd_completion(struct iser_desc *tx_desc)
struct iscsi_session *session = conn->session;

spin_lock(&conn->session->lock);
list_del(&mtask->running);
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
iscsi_free_mgmt_task(conn, mtask);
spin_unlock(&session->lock);
}
}
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4 changes: 1 addition & 3 deletions drivers/scsi/iscsi_tcp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1349,9 +1349,7 @@ iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
struct iscsi_session *session = conn->session;

spin_lock_bh(&session->lock);
list_del(&conn->mtask->running);
__kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
sizeof(void*));
iscsi_free_mgmt_task(conn, mtask);
spin_unlock_bh(&session->lock);
}
return 0;
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153 changes: 83 additions & 70 deletions drivers/scsi/libiscsi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -37,9 +37,6 @@
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/libiscsi.h>

static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
int err);

struct iscsi_session *
class_to_transport_session(struct iscsi_cls_session *cls_session)
{
Expand Down Expand Up @@ -274,6 +271,53 @@ static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
iscsi_complete_command(ctask);
}

/*
* session lock must be held
*/
static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
int err)
{
struct scsi_cmnd *sc;

sc = ctask->sc;
if (!sc)
return;

if (ctask->state == ISCSI_TASK_PENDING)
/*
* cmd never made it to the xmit thread, so we should not count
* the cmd in the sequencing
*/
conn->session->queued_cmdsn--;
else
conn->session->tt->cleanup_cmd_task(conn, ctask);

sc->result = err;
scsi_set_resid(sc, scsi_bufflen(sc));
if (conn->ctask == ctask)
conn->ctask = NULL;
/* release ref from queuecommand */
__iscsi_put_ctask(ctask);
}

/**
* iscsi_free_mgmt_task - return mgmt task back to pool
* @conn: iscsi connection
* @mtask: mtask
*
* Must be called with session lock.
*/
void iscsi_free_mgmt_task(struct iscsi_conn *conn,
struct iscsi_mgmt_task *mtask)
{
list_del_init(&mtask->running);
if (conn->login_mtask == mtask)
return;
__kfifo_put(conn->session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
}
EXPORT_SYMBOL_GPL(iscsi_free_mgmt_task);

/**
* iscsi_cmd_rsp - SCSI Command Response processing
* @conn: iscsi connection
Expand Down Expand Up @@ -464,10 +508,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
*/
if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
list_del_init(&mtask->running);
if (conn->login_mtask != mtask)
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
iscsi_free_mgmt_task(conn, mtask);
break;
case ISCSI_OP_SCSI_TMFUNC_RSP:
if (datalen) {
Expand All @@ -476,6 +517,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
}

iscsi_tmf_rsp(conn, hdr);
iscsi_free_mgmt_task(conn, mtask);
break;
case ISCSI_OP_NOOP_IN:
if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
Expand All @@ -486,9 +528,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,

if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
list_del_init(&mtask->running);
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
iscsi_free_mgmt_task(conn, mtask);
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
Expand Down Expand Up @@ -650,26 +690,19 @@ static void iscsi_prep_mtask(struct iscsi_conn *conn,
static int iscsi_xmit_mtask(struct iscsi_conn *conn)
{
struct iscsi_hdr *hdr = conn->mtask->hdr;
int rc, was_logout = 0;
int rc;

if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
conn->session->state = ISCSI_STATE_LOGGING_OUT;
spin_unlock_bh(&conn->session->lock);
if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT) {
conn->session->state = ISCSI_STATE_IN_RECOVERY;
iscsi_block_session(session_to_cls(conn->session));
was_logout = 1;
}

rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
spin_lock_bh(&conn->session->lock);
if (rc)
return rc;

/* done with this in-progress mtask */
conn->mtask = NULL;

if (was_logout) {
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
return -ENODATA;
}
return 0;
}

Expand Down Expand Up @@ -763,6 +796,12 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
while (!list_empty(&conn->mgmtqueue)) {
conn->mtask = list_entry(conn->mgmtqueue.next,
struct iscsi_mgmt_task, running);
if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
iscsi_free_mgmt_task(conn, conn->mtask);
conn->mtask = NULL;
continue;
}

iscsi_prep_mtask(conn, conn->mtask);
list_move_tail(conn->mgmtqueue.next, &conn->mgmt_run_list);
rc = iscsi_xmit_mtask(conn);
Expand All @@ -777,6 +816,10 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)

conn->ctask = list_entry(conn->xmitqueue.next,
struct iscsi_cmd_task, running);
if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
fail_command(conn, conn->ctask, DID_NO_CONNECT << 16);
continue;
}
if (iscsi_prep_scsi_cmd_pdu(conn->ctask)) {
fail_command(conn, conn->ctask, DID_ABORT << 16);
continue;
Expand All @@ -800,6 +843,12 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
break;

/*
* we always do fastlogout - conn stop code will clean up.
*/
if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
break;

conn->ctask = list_entry(conn->requeue.next,
struct iscsi_cmd_task, running);
conn->ctask->state = ISCSI_TASK_RUNNING;
Expand Down Expand Up @@ -842,6 +891,7 @@ enum {
FAILURE_SESSION_TERMINATE,
FAILURE_SESSION_IN_RECOVERY,
FAILURE_SESSION_RECOVERY_TIMEOUT,
FAILURE_SESSION_LOGGING_OUT,
};

int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
Expand Down Expand Up @@ -879,12 +929,19 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
goto reject;
}

if (session->state == ISCSI_STATE_RECOVERY_FAILED)
switch (session->state) {
case ISCSI_STATE_RECOVERY_FAILED:
reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
else if (session->state == ISCSI_STATE_TERMINATE)
break;
case ISCSI_STATE_TERMINATE:
reason = FAILURE_SESSION_TERMINATE;
else
break;
case ISCSI_STATE_LOGGING_OUT:
reason = FAILURE_SESSION_LOGGING_OUT;
break;
default:
reason = FAILURE_SESSION_FREED;
}
goto fault;
}

Expand Down Expand Up @@ -1120,44 +1177,9 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
if (age != session->age ||
session->state != ISCSI_STATE_LOGGED_IN)
return -ENOTCONN;

if (!list_empty(&mtask->running)) {
list_del_init(&mtask->running);
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
}
return 0;
}

/*
* session lock must be held
*/
static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
int err)
{
struct scsi_cmnd *sc;

sc = ctask->sc;
if (!sc)
return;

if (ctask->state == ISCSI_TASK_PENDING)
/*
* cmd never made it to the xmit thread, so we should not count
* the cmd in the sequencing
*/
conn->session->queued_cmdsn--;
else
conn->session->tt->cleanup_cmd_task(conn, ctask);

sc->result = err;
scsi_set_resid(sc, scsi_bufflen(sc));
if (conn->ctask == ctask)
conn->ctask = NULL;
/* release ref from queuecommand */
__iscsi_put_ctask(ctask);
}

/*
* Fail commands. session lock held and recv side suspended and xmit
* thread flushed
Expand Down Expand Up @@ -1837,22 +1859,13 @@ flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
/* handle pending */
list_for_each_entry_safe(mtask, tmp, &conn->mgmtqueue, running) {
debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
list_del_init(&mtask->running);
if (mtask == conn->login_mtask)
continue;
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
iscsi_free_mgmt_task(conn, mtask);
}

/* handle running */
list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
list_del_init(&mtask->running);

if (mtask == conn->login_mtask)
continue;
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
iscsi_free_mgmt_task(conn, mtask);
}

conn->mtask = NULL;
Expand Down
2 changes: 2 additions & 0 deletions include/scsi/libiscsi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -346,6 +346,8 @@ extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
uint32_t *);
extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
extern void iscsi_free_mgmt_task(struct iscsi_conn *conn,
struct iscsi_mgmt_task *mtask);

/*
* generic helpers
Expand Down
1 change: 1 addition & 0 deletions include/scsi/scsi_transport_iscsi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -176,6 +176,7 @@ struct iscsi_cls_conn {
#define ISCSI_STATE_TERMINATE 4
#define ISCSI_STATE_IN_RECOVERY 5
#define ISCSI_STATE_RECOVERY_FAILED 6
#define ISCSI_STATE_LOGGING_OUT 7

struct iscsi_cls_session {
struct list_head sess_list; /* item in session_list */
Expand Down

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