Fixed MTP to work with TWRP

drivers/target/tcm_fc/tfc_sess.c

@@ -0,0 +1,504 @@
+/*
+ * 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/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/libfc.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_configfs.h>
+#include <target/configfs_macros.h>
+
+#include "tcm_fc.h"
+
+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;
+	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);
+	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;
+
+	rcu_read_lock();
+	tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
+	if (!tport)
+		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();
+			pr_debug("port_id %x found %p\n", port_id, sess);
+			return sess;
+		}
+	}
+out:
+	rcu_read_unlock();
+	pr_debug("port_id %x not found\n", port_id);
+	return NULL;
+}
+
+/*
+ * 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 ft_node_acl *acl)
+{
+	struct ft_sess *sess;
+	struct hlist_head *head;
+
+	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 NULL;
+
+	sess->se_sess = transport_init_session_tags(TCM_FC_DEFAULT_TAGS,
+						    sizeof(struct ft_cmd),
+						    TARGET_PROT_NORMAL);
+	if (IS_ERR(sess->se_sess)) {
+		kfree(sess);
+		return NULL;
+	}
+	sess->se_sess->se_node_acl = &acl->se_node_acl;
+	sess->tport = tport;
+	sess->port_id = port_id;
+	kref_init(&sess->kref);	/* ref for table entry */
+	hlist_add_head_rcu(&sess->hash, head);
+	tport->sess_count++;
+
+	pr_debug("port_id %x sess %p\n", port_id, sess);
+
+	transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
+				   sess->se_sess, sess);
+	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;
+}
+
+/*
+ * 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);
+			transport_deregister_session_configfs(sess->se_sess);
+			ft_sess_put(sess);	/* release from table */
+		}
+	}
+}
+
+/*
+ * TCM ops for sessions.
+ */
+
+/*
+ * Determine whether session is allowed to be shutdown in the current context.
+ * Returns non-zero if the session should be shutdown.
+ */
+int ft_sess_shutdown(struct se_session *se_sess)
+{
+	struct ft_sess *sess = se_sess->fabric_sess_ptr;
+
+	pr_debug("port_id %x\n", sess->port_id);
+	return 1;
+}
+
+/*
+ * 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;
+	}
+	pr_debug("port_id %x\n", port_id);
+	ft_sess_unhash(sess);
+	mutex_unlock(&ft_lport_lock);
+	transport_deregister_session_configfs(se_sess);
+	ft_sess_put(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;
+	struct ft_node_acl *acl;
+	u32 fcp_parm;
+
+	tport = ft_tport_get(rdata->local_port);
+	if (!tport)
+		goto not_target;	/* not a target for this local port */
+
+	acl = ft_acl_get(tport->tpg, rdata);
+	if (!acl)
+		goto not_target;	/* no target for this remote */
+
+	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, acl);
+		if (!sess)
+			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);
+	pr_debug("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);
+
+	transport_deregister_session(sess->se_sess);
+	kfree_rcu(sess, rcu);
+}
+
+void ft_sess_put(struct ft_sess *sess)
+{
+	int sess_held = atomic_read(&sess->kref.refcount);
+
+	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);
+	transport_deregister_session_configfs(sess->se_sess);
+	ft_sess_put(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);
+
+	pr_debug("sid %x\n", sid);
+
+	sess = ft_sess_get(lport, sid);
+	if (!sess) {
+		pr_debug("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,
+};