linux/drivers/target/tcm_fc/tfc_sess.c
Mike Christie 60daca1006 scsi: tcm_fc: use target_remove_session
This converts tcm_fc to use target_remove_session

tcm_fc was calling transport_deregister_session_configfs then calling
transport_deregister_session when commands have completed. It should be ok
for it to call transport_deregister_session_configfs later via
target_remove_session because transport_deregister_session_configfs only
prevents access from configfs via tpg removal and its call to the
close_session callback for that driver, and this is already protected by
the ft_lport_lock and its port lookup handling.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02 15:29:31 -04:00

516 lines
12 KiB
C

/*
* Copyright (c) 2010 Cisco Systems, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* XXX TBD some includes may be extraneous */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/utsname.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/configfs.h>
#include <linux/ctype.h>
#include <linux/hash.h>
#include <linux/rcupdate.h>
#include <linux/rculist.h>
#include <linux/kref.h>
#include <asm/unaligned.h>
#include <scsi/libfc.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include "tcm_fc.h"
#define TFC_SESS_DBG(lport, fmt, args...) \
pr_debug("host%u: rport %6.6x: " fmt, \
(lport)->host->host_no, \
(lport)->port_id, ##args )
static void ft_sess_delete_all(struct ft_tport *);
/*
* Lookup or allocate target local port.
* Caller holds ft_lport_lock.
*/
static struct ft_tport *ft_tport_get(struct fc_lport *lport)
{
struct ft_tpg *tpg;
struct ft_tport *tport;
int i;
tport = rcu_dereference_protected(lport->prov[FC_TYPE_FCP],
lockdep_is_held(&ft_lport_lock));
if (tport && tport->tpg)
return tport;
tpg = ft_lport_find_tpg(lport);
if (!tpg)
return NULL;
if (tport) {
tport->tpg = tpg;
tpg->tport = tport;
return tport;
}
tport = kzalloc(sizeof(*tport), GFP_KERNEL);
if (!tport)
return NULL;
tport->lport = lport;
tport->tpg = tpg;
tpg->tport = tport;
for (i = 0; i < FT_SESS_HASH_SIZE; i++)
INIT_HLIST_HEAD(&tport->hash[i]);
rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
return tport;
}
/*
* Delete a target local port.
* Caller holds ft_lport_lock.
*/
static void ft_tport_delete(struct ft_tport *tport)
{
struct fc_lport *lport;
struct ft_tpg *tpg;
ft_sess_delete_all(tport);
lport = tport->lport;
lport->service_params &= ~FCP_SPPF_TARG_FCN;
BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
RCU_INIT_POINTER(lport->prov[FC_TYPE_FCP], NULL);
tpg = tport->tpg;
if (tpg) {
tpg->tport = NULL;
tport->tpg = NULL;
}
kfree_rcu(tport, rcu);
}
/*
* Add local port.
* Called thru fc_lport_iterate().
*/
void ft_lport_add(struct fc_lport *lport, void *arg)
{
mutex_lock(&ft_lport_lock);
ft_tport_get(lport);
lport->service_params |= FCP_SPPF_TARG_FCN;
mutex_unlock(&ft_lport_lock);
}
/*
* Delete local port.
* Called thru fc_lport_iterate().
*/
void ft_lport_del(struct fc_lport *lport, void *arg)
{
struct ft_tport *tport;
mutex_lock(&ft_lport_lock);
tport = lport->prov[FC_TYPE_FCP];
if (tport)
ft_tport_delete(tport);
mutex_unlock(&ft_lport_lock);
}
/*
* Notification of local port change from libfc.
* Create or delete local port and associated tport.
*/
int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
{
struct fc_lport *lport = arg;
switch (event) {
case FC_LPORT_EV_ADD:
ft_lport_add(lport, NULL);
break;
case FC_LPORT_EV_DEL:
ft_lport_del(lport, NULL);
break;
}
return NOTIFY_DONE;
}
/*
* Hash function for FC_IDs.
*/
static u32 ft_sess_hash(u32 port_id)
{
return hash_32(port_id, FT_SESS_HASH_BITS);
}
/*
* Find session in local port.
* Sessions and hash lists are RCU-protected.
* A reference is taken which must be eventually freed.
*/
static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
{
struct ft_tport *tport;
struct hlist_head *head;
struct ft_sess *sess;
char *reason = "no session created";
rcu_read_lock();
tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
if (!tport) {
reason = "not an FCP port";
goto out;
}
head = &tport->hash[ft_sess_hash(port_id)];
hlist_for_each_entry_rcu(sess, head, hash) {
if (sess->port_id == port_id) {
kref_get(&sess->kref);
rcu_read_unlock();
TFC_SESS_DBG(lport, "port_id %x found %p\n",
port_id, sess);
return sess;
}
}
out:
rcu_read_unlock();
TFC_SESS_DBG(lport, "port_id %x not found, %s\n",
port_id, reason);
return NULL;
}
static int ft_sess_alloc_cb(struct se_portal_group *se_tpg,
struct se_session *se_sess, void *p)
{
struct ft_sess *sess = p;
struct ft_tport *tport = sess->tport;
struct hlist_head *head = &tport->hash[ft_sess_hash(sess->port_id)];
TFC_SESS_DBG(tport->lport, "port_id %x sess %p\n", sess->port_id, sess);
hlist_add_head_rcu(&sess->hash, head);
tport->sess_count++;
return 0;
}
/*
* Allocate session and enter it in the hash for the local port.
* Caller holds ft_lport_lock.
*/
static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
struct fc_rport_priv *rdata)
{
struct se_portal_group *se_tpg = &tport->tpg->se_tpg;
struct ft_sess *sess;
struct hlist_head *head;
unsigned char initiatorname[TRANSPORT_IQN_LEN];
ft_format_wwn(&initiatorname[0], TRANSPORT_IQN_LEN, rdata->ids.port_name);
head = &tport->hash[ft_sess_hash(port_id)];
hlist_for_each_entry_rcu(sess, head, hash)
if (sess->port_id == port_id)
return sess;
sess = kzalloc(sizeof(*sess), GFP_KERNEL);
if (!sess)
return ERR_PTR(-ENOMEM);
kref_init(&sess->kref); /* ref for table entry */
sess->tport = tport;
sess->port_id = port_id;
sess->se_sess = target_setup_session(se_tpg, TCM_FC_DEFAULT_TAGS,
sizeof(struct ft_cmd),
TARGET_PROT_NORMAL, &initiatorname[0],
sess, ft_sess_alloc_cb);
if (IS_ERR(sess->se_sess)) {
int rc = PTR_ERR(sess->se_sess);
kfree(sess);
sess = ERR_PTR(rc);
}
return sess;
}
/*
* Unhash the session.
* Caller holds ft_lport_lock.
*/
static void ft_sess_unhash(struct ft_sess *sess)
{
struct ft_tport *tport = sess->tport;
hlist_del_rcu(&sess->hash);
BUG_ON(!tport->sess_count);
tport->sess_count--;
sess->port_id = -1;
sess->params = 0;
}
/*
* Delete session from hash.
* Caller holds ft_lport_lock.
*/
static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
{
struct hlist_head *head;
struct ft_sess *sess;
head = &tport->hash[ft_sess_hash(port_id)];
hlist_for_each_entry_rcu(sess, head, hash) {
if (sess->port_id == port_id) {
ft_sess_unhash(sess);
return sess;
}
}
return NULL;
}
static void ft_close_sess(struct ft_sess *sess)
{
target_sess_cmd_list_set_waiting(sess->se_sess);
target_wait_for_sess_cmds(sess->se_sess);
ft_sess_put(sess);
}
/*
* Delete all sessions from tport.
* Caller holds ft_lport_lock.
*/
static void ft_sess_delete_all(struct ft_tport *tport)
{
struct hlist_head *head;
struct ft_sess *sess;
for (head = tport->hash;
head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
hlist_for_each_entry_rcu(sess, head, hash) {
ft_sess_unhash(sess);
ft_close_sess(sess); /* release from table */
}
}
}
/*
* TCM ops for sessions.
*/
/*
* Remove session and send PRLO.
* This is called when the ACL is being deleted or queue depth is changing.
*/
void ft_sess_close(struct se_session *se_sess)
{
struct ft_sess *sess = se_sess->fabric_sess_ptr;
u32 port_id;
mutex_lock(&ft_lport_lock);
port_id = sess->port_id;
if (port_id == -1) {
mutex_unlock(&ft_lport_lock);
return;
}
TFC_SESS_DBG(sess->tport->lport, "port_id %x close session\n", port_id);
ft_sess_unhash(sess);
mutex_unlock(&ft_lport_lock);
ft_close_sess(sess);
/* XXX Send LOGO or PRLO */
synchronize_rcu(); /* let transport deregister happen */
}
u32 ft_sess_get_index(struct se_session *se_sess)
{
struct ft_sess *sess = se_sess->fabric_sess_ptr;
return sess->port_id; /* XXX TBD probably not what is needed */
}
u32 ft_sess_get_port_name(struct se_session *se_sess,
unsigned char *buf, u32 len)
{
struct ft_sess *sess = se_sess->fabric_sess_ptr;
return ft_format_wwn(buf, len, sess->port_name);
}
/*
* libfc ops involving sessions.
*/
static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
const struct fc_els_spp *rspp, struct fc_els_spp *spp)
{
struct ft_tport *tport;
struct ft_sess *sess;
u32 fcp_parm;
tport = ft_tport_get(rdata->local_port);
if (!tport)
goto not_target; /* not a target for this local port */
if (!rspp)
goto fill;
if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
return FC_SPP_RESP_NO_PA;
/*
* If both target and initiator bits are off, the SPP is invalid.
*/
fcp_parm = ntohl(rspp->spp_params);
if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
return FC_SPP_RESP_INVL;
/*
* Create session (image pair) only if requested by
* EST_IMG_PAIR flag and if the requestor is an initiator.
*/
if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
if (!(fcp_parm & FCP_SPPF_INIT_FCN))
return FC_SPP_RESP_CONF;
sess = ft_sess_create(tport, rdata->ids.port_id, rdata);
if (IS_ERR(sess)) {
if (PTR_ERR(sess) == -EACCES) {
spp->spp_flags &= ~FC_SPP_EST_IMG_PAIR;
return FC_SPP_RESP_CONF;
} else
return FC_SPP_RESP_RES;
}
if (!sess->params)
rdata->prli_count++;
sess->params = fcp_parm;
sess->port_name = rdata->ids.port_name;
sess->max_frame = rdata->maxframe_size;
/* XXX TBD - clearing actions. unit attn, see 4.10 */
}
/*
* OR in our service parameters with other provider (initiator), if any.
*/
fill:
fcp_parm = ntohl(spp->spp_params);
fcp_parm &= ~FCP_SPPF_RETRY;
spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
return FC_SPP_RESP_ACK;
not_target:
fcp_parm = ntohl(spp->spp_params);
fcp_parm &= ~FCP_SPPF_TARG_FCN;
spp->spp_params = htonl(fcp_parm);
return 0;
}
/**
* tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
* @rdata: remote port private
* @spp_len: service parameter page length
* @rspp: received service parameter page (NULL for outgoing PRLI)
* @spp: response service parameter page
*
* Returns spp response code.
*/
static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
const struct fc_els_spp *rspp, struct fc_els_spp *spp)
{
int ret;
mutex_lock(&ft_lport_lock);
ret = ft_prli_locked(rdata, spp_len, rspp, spp);
mutex_unlock(&ft_lport_lock);
TFC_SESS_DBG(rdata->local_port, "port_id %x flags %x ret %x\n",
rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
return ret;
}
static void ft_sess_free(struct kref *kref)
{
struct ft_sess *sess = container_of(kref, struct ft_sess, kref);
target_remove_session(sess->se_sess);
kfree_rcu(sess, rcu);
}
void ft_sess_put(struct ft_sess *sess)
{
int sess_held = kref_read(&sess->kref);
BUG_ON(!sess_held);
kref_put(&sess->kref, ft_sess_free);
}
static void ft_prlo(struct fc_rport_priv *rdata)
{
struct ft_sess *sess;
struct ft_tport *tport;
mutex_lock(&ft_lport_lock);
tport = rcu_dereference_protected(rdata->local_port->prov[FC_TYPE_FCP],
lockdep_is_held(&ft_lport_lock));
if (!tport) {
mutex_unlock(&ft_lport_lock);
return;
}
sess = ft_sess_delete(tport, rdata->ids.port_id);
if (!sess) {
mutex_unlock(&ft_lport_lock);
return;
}
mutex_unlock(&ft_lport_lock);
ft_close_sess(sess); /* release from table */
rdata->prli_count--;
/* XXX TBD - clearing actions. unit attn, see 4.10 */
}
/*
* Handle incoming FCP request.
* Caller has verified that the frame is type FCP.
*/
static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
{
struct ft_sess *sess;
u32 sid = fc_frame_sid(fp);
TFC_SESS_DBG(lport, "recv sid %x\n", sid);
sess = ft_sess_get(lport, sid);
if (!sess) {
TFC_SESS_DBG(lport, "sid %x sess lookup failed\n", sid);
/* TBD XXX - if FCP_CMND, send PRLO */
fc_frame_free(fp);
return;
}
ft_recv_req(sess, fp); /* must do ft_sess_put() */
}
/*
* Provider ops for libfc.
*/
struct fc4_prov ft_prov = {
.prli = ft_prli,
.prlo = ft_prlo,
.recv = ft_recv,
.module = THIS_MODULE,
};