RDMA/srpt: Fix TPG creation

Unlike the iSCSI target driver, for the SRP target driver it is sufficient
if a single TPG can be associated with each RDMA port name. However, users
started associating multiple TPGs with RDMA port names. Support this by
converting the single TPG in struct srpt_port_id into a list. This patch
fixes the following list corruption issue:

 list_add corruption. prev->next should be next (ffffffffc0a080c0), but was ffffa08a994ce6f0. (prev=ffffa08a994ce6f0).
 WARNING: CPU: 2 PID: 2597 at lib/list_debug.c:28 __list_add_valid+0x6a/0x70
 CPU: 2 PID: 2597 Comm: targetcli Not tainted 5.4.0-rc1.3bfa3c9602a7 #1
 RIP: 0010:__list_add_valid+0x6a/0x70
 Call Trace:
  core_tpg_register+0x116/0x200 [target_core_mod]
  srpt_make_tpg+0x3f/0x60 [ib_srpt]
  target_fabric_make_tpg+0x41/0x290 [target_core_mod]
  configfs_mkdir+0x158/0x3e0
  vfs_mkdir+0x108/0x1a0
  do_mkdirat+0x77/0xe0
  do_syscall_64+0x55/0x1d0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Link: https://lore.kernel.org/r/20191023204106.23326-1-bvanassche@acm.org
Reported-by: Honggang LI <honli@redhat.com>
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index daf811abf40a6ebbc5400b6a597ac0e533a53033..a278e76b9e02241de908438f0df1930b6e6d6b5c 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2131,6 +2131,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
        char i_port_id[36];
        u32 it_iu_len;
        int i, tag_num, tag_size, ret;
+       struct srpt_tpg *stpg;
 
        WARN_ON_ONCE(irqs_disabled());
 
@@ -2288,19 +2289,33 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
 
        tag_num = ch->rq_size;
        tag_size = 1; /* ib_srpt does not use se_sess->sess_cmd_map */
-       if (sport->port_guid_id.tpg.se_tpg_wwn)
-               ch->sess = target_setup_session(&sport->port_guid_id.tpg, tag_num,
+
+       mutex_lock(&sport->port_guid_id.mutex);
+       list_for_each_entry(stpg, &sport->port_guid_id.tpg_list, entry) {
+               if (!IS_ERR_OR_NULL(ch->sess))
+                       break;
+               ch->sess = target_setup_session(&stpg->tpg, tag_num,
                                                tag_size, TARGET_PROT_NORMAL,
                                                ch->sess_name, ch, NULL);
-       if (sport->port_gid_id.tpg.se_tpg_wwn && IS_ERR_OR_NULL(ch->sess))
-               ch->sess = target_setup_session(&sport->port_gid_id.tpg, tag_num,
+       }
+       mutex_unlock(&sport->port_guid_id.mutex);
+
+       mutex_lock(&sport->port_gid_id.mutex);
+       list_for_each_entry(stpg, &sport->port_gid_id.tpg_list, entry) {
+               if (!IS_ERR_OR_NULL(ch->sess))
+                       break;
+               ch->sess = target_setup_session(&stpg->tpg, tag_num,
                                        tag_size, TARGET_PROT_NORMAL, i_port_id,
                                        ch, NULL);
-       /* Retry without leading "0x" */
-       if (sport->port_gid_id.tpg.se_tpg_wwn && IS_ERR_OR_NULL(ch->sess))
-               ch->sess = target_setup_session(&sport->port_gid_id.tpg, tag_num,
+               if (!IS_ERR_OR_NULL(ch->sess))
+                       break;
+               /* Retry without leading "0x" */
+               ch->sess = target_setup_session(&stpg->tpg, tag_num,
                                                tag_size, TARGET_PROT_NORMAL,
                                                i_port_id + 2, ch, NULL);
+       }
+       mutex_unlock(&sport->port_gid_id.mutex);
+
        if (IS_ERR_OR_NULL(ch->sess)) {
                WARN_ON_ONCE(ch->sess == NULL);
                ret = PTR_ERR(ch->sess);
@@ -3140,6 +3155,10 @@ static void srpt_add_one(struct ib_device *device)
                sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE;
                sport->port_attrib.use_srq = false;
                INIT_WORK(&sport->work, srpt_refresh_port_work);
+               mutex_init(&sport->port_guid_id.mutex);
+               INIT_LIST_HEAD(&sport->port_guid_id.tpg_list);
+               mutex_init(&sport->port_gid_id.mutex);
+               INIT_LIST_HEAD(&sport->port_gid_id.tpg_list);
 
                if (srpt_refresh_port(sport)) {
                        pr_err("MAD registration failed for %s-%d.\n",
@@ -3242,18 +3261,6 @@ static struct srpt_port *srpt_tpg_to_sport(struct se_portal_group *tpg)
        return tpg->se_tpg_wwn->priv;
 }
 
-static struct srpt_port_id *srpt_tpg_to_sport_id(struct se_portal_group *tpg)
-{
-       struct srpt_port *sport = srpt_tpg_to_sport(tpg);
-
-       if (tpg == &sport->port_guid_id.tpg)
-               return &sport->port_guid_id;
-       if (tpg == &sport->port_gid_id.tpg)
-               return &sport->port_gid_id;
-       WARN_ON_ONCE(true);
-       return NULL;
-}
-
 static struct srpt_port_id *srpt_wwn_to_sport_id(struct se_wwn *wwn)
 {
        struct srpt_port *sport = wwn->priv;
@@ -3268,7 +3275,9 @@ static struct srpt_port_id *srpt_wwn_to_sport_id(struct se_wwn *wwn)
 
 static char *srpt_get_fabric_wwn(struct se_portal_group *tpg)
 {
-       return srpt_tpg_to_sport_id(tpg)->name;
+       struct srpt_tpg *stpg = container_of(tpg, typeof(*stpg), tpg);
+
+       return stpg->sport_id->name;
 }
 
 static u16 srpt_get_tag(struct se_portal_group *tpg)
@@ -3725,16 +3734,27 @@ static struct se_portal_group *srpt_make_tpg(struct se_wwn *wwn,
                                             const char *name)
 {
        struct srpt_port *sport = wwn->priv;
-       struct se_portal_group *tpg = &srpt_wwn_to_sport_id(wwn)->tpg;
-       int res;
+       struct srpt_port_id *sport_id = srpt_wwn_to_sport_id(wwn);
+       struct srpt_tpg *stpg;
+       int res = -ENOMEM;
 
-       res = core_tpg_register(wwn, tpg, SCSI_PROTOCOL_SRP);
-       if (res)
+       stpg = kzalloc(sizeof(*stpg), GFP_KERNEL);
+       if (!stpg)
+               return ERR_PTR(res);
+       stpg->sport_id = sport_id;
+       res = core_tpg_register(wwn, &stpg->tpg, SCSI_PROTOCOL_SRP);
+       if (res) {
+               kfree(stpg);
                return ERR_PTR(res);
+       }
+
+       mutex_lock(&sport_id->mutex);
+       list_add_tail(&stpg->entry, &sport_id->tpg_list);
+       mutex_unlock(&sport_id->mutex);
 
        atomic_inc(&sport->refcount);
 
-       return tpg;
+       return &stpg->tpg;
 }
 
 /**
@@ -3743,10 +3763,17 @@ static struct se_portal_group *srpt_make_tpg(struct se_wwn *wwn,
  */
 static void srpt_drop_tpg(struct se_portal_group *tpg)
 {
+       struct srpt_tpg *stpg = container_of(tpg, typeof(*stpg), tpg);
+       struct srpt_port_id *sport_id = stpg->sport_id;
        struct srpt_port *sport = srpt_tpg_to_sport(tpg);
 
+       mutex_lock(&sport_id->mutex);
+       list_del(&stpg->entry);
+       mutex_unlock(&sport_id->mutex);
+
        sport->enabled = false;
        core_tpg_deregister(tpg);
+       kfree(stpg);
        srpt_drop_sport_ref(sport);
 }
 

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h
index 54b03ab4ab1a37caaffe66c04783ad3525d89fe9..2e1a69840857bf7260aeb867f669992fa90c44df 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.h
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.h
@@ -363,17 +363,34 @@ struct srpt_port_attrib {
        bool                    use_srq;
 };
 
+/**
+ * struct srpt_tpg - information about a single "target portal group"
+ * @entry:     Entry in @sport_id->tpg_list.
+ * @sport_id:  Port name this TPG is associated with.
+ * @tpg:       LIO TPG data structure.
+ *
+ * Zero or more target portal groups are associated with each port name
+ * (srpt_port_id). With each TPG an ACL list is associated.
+ */
+struct srpt_tpg {
+       struct list_head        entry;
+       struct srpt_port_id     *sport_id;
+       struct se_portal_group  tpg;
+};
+
 /**
  * struct srpt_port_id - information about an RDMA port name
- * @tpg: TPG associated with the RDMA port.
- * @wwn: WWN associated with the RDMA port.
- * @name: ASCII representation of the port name.
+ * @mutex:     Protects @tpg_list changes.
+ * @tpg_list:  TPGs associated with the RDMA port name.
+ * @wwn:       WWN associated with the RDMA port name.
+ * @name:      ASCII representation of the port name.
  *
  * Multiple sysfs directories can be associated with a single RDMA port. This
  * data structure represents a single (port, name) pair.
  */
 struct srpt_port_id {
-       struct se_portal_group  tpg;
+       struct mutex            mutex;
+       struct list_head        tpg_list;
        struct se_wwn           wwn;
        char                    name[64];
 };