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[SCSI] iscsi_tcp: convert to new alloc_hdr api
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This converts iscsi_tcp to the new api and modifies how
it handles r2ts.

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 Dec 29, 2008
1 parent 0f9c744 commit e5a7efe
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Showing 2 changed files with 121 additions and 149 deletions.
249 changes: 119 additions & 130 deletions drivers/scsi/iscsi_tcp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -57,13 +57,6 @@ MODULE_LICENSE("GPL");
#define debug_tcp(fmt...)
#endif

#ifndef DEBUG_ASSERT
#ifdef BUG_ON
#undef BUG_ON
#endif
#define BUG_ON(expr)
#endif

static struct scsi_transport_template *iscsi_tcp_scsi_transport;
static struct scsi_host_template iscsi_sht;
static struct iscsi_transport iscsi_tcp_transport;
Expand Down Expand Up @@ -498,14 +491,13 @@ iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
/*
* must be called with session lock
*/
static void
iscsi_tcp_cleanup_task(struct iscsi_conn *conn, struct iscsi_task *task)
static void iscsi_tcp_cleanup_task(struct iscsi_task *task)
{
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_r2t_info *r2t;

/* nothing to do for mgmt tasks */
if (!task->sc)
/* nothing to do for mgmt or pending tasks */
if (!task->sc || task->state == ISCSI_TASK_PENDING)
return;

/* flush task's r2t queues */
Expand Down Expand Up @@ -611,11 +603,11 @@ iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_task *task,
static int
iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
{
struct iscsi_r2t_info *r2t;
struct iscsi_session *session = conn->session;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
struct iscsi_r2t_info *r2t;
int r2tsn = be32_to_cpu(rhdr->r2tsn);
int rc;

Expand Down Expand Up @@ -643,7 +635,12 @@ iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
}

rc = __kfifo_get(tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*));
BUG_ON(!rc);
if (!rc) {
iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
"Target has sent more R2Ts than it "
"negotiated for or driver has has leaked.\n");
return ISCSI_ERR_PROTO;
}

r2t->exp_statsn = rhdr->statsn;
r2t->data_length = be32_to_cpu(rhdr->data_length);
Expand Down Expand Up @@ -672,9 +669,8 @@ iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
}

r2t->ttt = rhdr->ttt; /* no flip */
r2t->solicit_datasn = 0;

iscsi_solicit_data_init(conn, task, r2t);
r2t->datasn = 0;
r2t->sent = 0;

tcp_task->exp_datasn = r2tsn + 1;
__kfifo_put(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
Expand Down Expand Up @@ -1199,9 +1195,9 @@ iscsi_tcp_xmit_qlen(struct iscsi_conn *conn)
return segment->total_copied - segment->total_size;
}

static inline int
iscsi_tcp_flush(struct iscsi_conn *conn)
static int iscsi_tcp_flush(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
int rc;

while (iscsi_tcp_xmit_qlen(conn)) {
Expand Down Expand Up @@ -1364,14 +1360,49 @@ iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_task *task,
return 1;
}

static int iscsi_tcp_pdu_init(struct iscsi_task *task,
unsigned int offset, unsigned int count)
{
struct iscsi_conn *conn = task->conn;
int err = 0;

iscsi_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);

if (!count)
return 0;

if (!task->sc)
iscsi_tcp_send_linear_data_prepare(conn, task->data, count);
else {
struct scsi_data_buffer *sdb = scsi_out(task->sc);

err = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
sdb->table.nents, offset, count);
}

if (err) {
iscsi_conn_failure(conn, err);
return -EIO;
}
return 0;
}

static int iscsi_tcp_pdu_alloc(struct iscsi_task *task)
{
struct iscsi_tcp_task *tcp_task = task->dd_data;

task->hdr = &tcp_task->hdr.hdrbuf;
task->hdr_max = sizeof(tcp_task->hdr) - ISCSI_DIGEST_SIZE;
return 0;
}

/**
* iscsi_tcp_task - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
* @conn: iscsi connection
* @task: scsi command task
* @sc: scsi command
**/
static int
iscsi_tcp_task_init(struct iscsi_task *task)
static int iscsi_tcp_task_init(struct iscsi_task *task)
{
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_conn *conn = task->conn;
Expand All @@ -1386,40 +1417,57 @@ iscsi_tcp_task_init(struct iscsi_task *task)
debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id,
task->itt);

/* Prepare PDU, optionally w/ immediate data */
iscsi_tcp_send_hdr_prep(conn, task->hdr, sizeof(*task->hdr));

/* If we have immediate data, attach a payload */
if (task->data_count)
iscsi_tcp_send_linear_data_prepare(conn, task->data,
task->data_count);
return 0;
return conn->session->tt->init_pdu(task, 0, task->data_count);
}

BUG_ON(__kfifo_len(tcp_task->r2tqueue));
tcp_task->sent = 0;
tcp_task->exp_datasn = 0;

/* Prepare PDU, optionally w/ immediate data */
debug_scsi("task deq [cid %d itt 0x%x imm %d unsol %d]\n",
conn->id, task->itt, task->imm_count,
task->unsol_count);
iscsi_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
task->unsol_r2t.data_length);

if (!task->imm_count)
return 0;

/* If we have immediate data, attach a payload */
err = iscsi_tcp_send_data_prep(conn, scsi_out(sc)->table.sgl,
scsi_out(sc)->table.nents,
0, task->imm_count);
err = conn->session->tt->init_pdu(task, 0, task->imm_count);
if (err)
return err;
tcp_task->sent += task->imm_count;
task->imm_count = 0;
return 0;
}

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);
if (tcp_task->r2t) {
r2t = tcp_task->r2t;
/* Continue with this R2T? */
if (r2t->data_length <= r2t->sent) {
debug_scsi(" done with r2t %p\n", r2t);
__kfifo_put(tcp_task->r2tpool.queue,
(void *)&tcp_task->r2t,
sizeof(void *));
tcp_task->r2t = r2t = NULL;
}
}

if (r2t == NULL) {
__kfifo_get(tcp_task->r2tqueue,
(void *)&tcp_task->r2t, sizeof(void *));
r2t = tcp_task->r2t;
}
spin_unlock_bh(&session->lock);
}

return r2t;
}

/*
* iscsi_tcp_task_xmit - xmit normal PDU task
* @task: iscsi command task
Expand All @@ -1428,108 +1476,52 @@ iscsi_tcp_task_init(struct iscsi_task *task)
* -EAGAIN if there's still data in the queue, or != 0 for any other kind
* of error.
*/
static int
iscsi_tcp_task_xmit(struct iscsi_task *task)
static int iscsi_tcp_task_xmit(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct scsi_cmnd *sc = task->sc;
struct scsi_data_buffer *sdb;
struct iscsi_session *session = conn->session;
struct iscsi_r2t_info *r2t;
int rc = 0;

flush:
/* Flush any pending data first. */
rc = iscsi_tcp_flush(conn);
rc = session->tt->xmit_pdu(task);
if (rc < 0)
return rc;

/* mgmt command */
if (!sc) {
if (!task->sc) {
if (task->hdr->itt == RESERVED_ITT)
iscsi_put_task(task);
return 0;
}

/* Are we done already? */
if (sc->sc_data_direction != DMA_TO_DEVICE)
if (task->sc->sc_data_direction != DMA_TO_DEVICE)
return 0;

sdb = scsi_out(sc);
if (task->unsol_count != 0) {
struct iscsi_data *hdr = &tcp_task->unsol_dtask.hdr;

/* Prepare a header for the unsolicited PDU.
* The amount of data we want to send will be
* in task->data_count.
* FIXME: return the data count instead.
*/
iscsi_prep_unsolicit_data_pdu(task, hdr);

debug_tcp("unsol dout [itt 0x%x doff %d dlen %d]\n",
task->itt, tcp_task->sent, task->data_count);

iscsi_tcp_send_hdr_prep(conn, hdr, sizeof(*hdr));
rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
sdb->table.nents, tcp_task->sent,
task->data_count);
if (rc)
goto fail;
tcp_task->sent += task->data_count;
task->unsol_count -= task->data_count;
goto flush;
} else {
struct iscsi_session *session = conn->session;
struct iscsi_r2t_info *r2t;

/* All unsolicited PDUs sent. Check for solicited PDUs.
*/
spin_lock_bh(&session->lock);
r2t = tcp_task->r2t;
if (r2t != NULL) {
/* Continue with this R2T? */
if (!iscsi_solicit_data_cont(conn, task, r2t)) {
debug_scsi(" done with r2t %p\n", r2t);

__kfifo_put(tcp_task->r2tpool.queue,
(void*)&r2t, sizeof(void*));
tcp_task->r2t = r2t = NULL;
}
}

if (r2t == NULL) {
__kfifo_get(tcp_task->r2tqueue, (void*)&tcp_task->r2t,
sizeof(void*));
r2t = tcp_task->r2t;
}
spin_unlock_bh(&session->lock);

r2t = iscsi_tcp_get_curr_r2t(task);
if (r2t == NULL) {
/* Waiting for more R2Ts to arrive. */
if (r2t == NULL) {
debug_tcp("no R2Ts yet\n");
return 0;
}
debug_tcp("no R2Ts yet\n");
return 0;
}

debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
r2t, r2t->solicit_datasn - 1, task->itt,
r2t->data_offset + r2t->sent, r2t->data_count);
rc = conn->session->tt->alloc_pdu(task);
if (rc)
return rc;
iscsi_prep_data_out_pdu(task, r2t, (struct iscsi_data *) task->hdr);

iscsi_tcp_send_hdr_prep(conn, &r2t->dtask.hdr,
sizeof(struct iscsi_hdr));
debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
r2t, r2t->datasn - 1, task->hdr->itt,
r2t->data_offset + r2t->sent, r2t->data_count);

rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
sdb->table.nents,
r2t->data_offset + r2t->sent,
r2t->data_count);
if (rc)
goto fail;
tcp_task->sent += r2t->data_count;
r2t->sent += r2t->data_count;
goto flush;
}
return 0;
fail:
iscsi_conn_failure(conn, rc);
return -EIO;
rc = conn->session->tt->init_pdu(task, r2t->data_offset + r2t->sent,
r2t->data_count);
if (rc)
return rc;
r2t->sent += r2t->data_count;
goto flush;
}

static struct iscsi_cls_conn *
Expand Down Expand Up @@ -1751,13 +1743,14 @@ iscsi_r2tpool_alloc(struct iscsi_session *session)
struct iscsi_tcp_task *tcp_task = task->dd_data;

/*
* pre-allocated x4 as much r2ts to handle race when
* pre-allocated x2 as much r2ts to handle race when
* target acks DataOut faster than we data_xmit() queues
* could replenish r2tqueue.
*/

/* R2T pool */
if (iscsi_pool_init(&tcp_task->r2tpool, session->max_r2t * 4, NULL,
if (iscsi_pool_init(&tcp_task->r2tpool,
session->max_r2t * 2, NULL,
sizeof(struct iscsi_r2t_info))) {
goto r2t_alloc_fail;
}
Expand Down Expand Up @@ -1891,7 +1884,6 @@ iscsi_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct Scsi_Host *shost;
int cmd_i;

if (ep) {
printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
Expand Down Expand Up @@ -1919,14 +1911,6 @@ iscsi_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
session = cls_session->dd_data;

shost->can_queue = session->scsi_cmds_max;
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
struct iscsi_task *task = session->cmds[cmd_i];
struct iscsi_tcp_task *tcp_task = task->dd_data;

task->hdr = &tcp_task->hdr.cmd_hdr;
task->hdr_max = sizeof(tcp_task->hdr) - ISCSI_DIGEST_SIZE;
}

if (iscsi_r2tpool_alloc(session))
goto remove_session;
return cls_session;
Expand Down Expand Up @@ -2026,9 +2010,14 @@ static struct iscsi_transport iscsi_tcp_transport = {
/* IO */
.send_pdu = iscsi_conn_send_pdu,
.get_stats = iscsi_conn_get_stats,
/* iscsi task/cmd helpers */
.init_task = iscsi_tcp_task_init,
.xmit_task = iscsi_tcp_task_xmit,
.cleanup_task = iscsi_tcp_cleanup_task,
/* low level pdu helpers */
.xmit_pdu = iscsi_tcp_flush,
.init_pdu = iscsi_tcp_pdu_init,
.alloc_pdu = iscsi_tcp_pdu_alloc,
/* recovery */
.session_recovery_timedout = iscsi_session_recovery_timedout,
};
Expand Down
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