RDS: Rewrite connection cleanup, fixing oops on rmmod
This fixes a bug where a connection was unexpectedly
not on *any* list while being destroyed. It also
cleans up some code duplication and regularizes some
function names.
* Grab appropriate lock in conn_free() and explain in comment
* Ensure via locking that a conn is never not on either
a dev's list or the nodev list
* Add rds_xx_remove_conn() to match rds_xx_add_conn()
* Make rds_xx_add_conn() return void
* Rename remove_{,nodev_}conns() to
destroy_{,nodev_}conns() and unify their implementation
in a helper function
* Document lock ordering as nodev conn_lock before
dev_conn_lock
Reported-by: Yosef Etigin <yosefe@voltaire.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/ib.c b/net/rds/ib.c
index 06a7b79..4933b38 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -51,6 +51,7 @@
struct list_head rds_ib_devices;
+/* NOTE: if also grabbing ibdev lock, grab this first */
DEFINE_SPINLOCK(ib_nodev_conns_lock);
LIST_HEAD(ib_nodev_conns);
@@ -137,7 +138,7 @@
kfree(i_ipaddr);
}
- rds_ib_remove_conns(rds_ibdev);
+ rds_ib_destroy_conns(rds_ibdev);
if (rds_ibdev->mr_pool)
rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
@@ -249,7 +250,7 @@
void rds_ib_exit(void)
{
rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
- rds_ib_remove_nodev_conns();
+ rds_ib_destroy_nodev_conns();
ib_unregister_client(&rds_ib_client);
rds_ib_sysctl_exit();
rds_ib_recv_exit();
diff --git a/net/rds/ib.h b/net/rds/ib.h
index 8be563a..c08ffff 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -267,9 +267,17 @@
/* ib_rdma.c */
int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr);
-int rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
-void rds_ib_remove_nodev_conns(void);
-void rds_ib_remove_conns(struct rds_ib_device *rds_ibdev);
+void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
+void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
+void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock);
+static inline void rds_ib_destroy_nodev_conns(void)
+{
+ __rds_ib_destroy_conns(&ib_nodev_conns, &ib_nodev_conns_lock);
+}
+static inline void rds_ib_destroy_conns(struct rds_ib_device *rds_ibdev)
+{
+ __rds_ib_destroy_conns(&rds_ibdev->conn_list, &rds_ibdev->spinlock);
+}
struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *);
void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo);
void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *);
diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c
index 0532237..889ab04 100644
--- a/net/rds/ib_cm.c
+++ b/net/rds/ib_cm.c
@@ -126,9 +126,7 @@
err = rds_ib_update_ipaddr(rds_ibdev, conn->c_laddr);
if (err)
printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n", err);
- err = rds_ib_add_conn(rds_ibdev, conn);
- if (err)
- printk(KERN_ERR "rds_ib_add_conn failed (%d)\n", err);
+ rds_ib_add_conn(rds_ibdev, conn);
/* If the peer gave us the last packet it saw, process this as if
* we had received a regular ACK. */
@@ -616,18 +614,8 @@
/*
* Move connection back to the nodev list.
*/
- if (ic->rds_ibdev) {
-
- spin_lock_irq(&ic->rds_ibdev->spinlock);
- BUG_ON(list_empty(&ic->ib_node));
- list_del(&ic->ib_node);
- spin_unlock_irq(&ic->rds_ibdev->spinlock);
-
- spin_lock_irq(&ib_nodev_conns_lock);
- list_add_tail(&ic->ib_node, &ib_nodev_conns);
- spin_unlock_irq(&ib_nodev_conns_lock);
- ic->rds_ibdev = NULL;
- }
+ if (ic->rds_ibdev)
+ rds_ib_remove_conn(ic->rds_ibdev, conn);
ic->i_cm_id = NULL;
ic->i_pd = NULL;
@@ -701,11 +689,27 @@
return 0;
}
+/*
+ * Free a connection. Connection must be shut down and not set for reconnect.
+ */
void rds_ib_conn_free(void *arg)
{
struct rds_ib_connection *ic = arg;
+ spinlock_t *lock_ptr;
+
rdsdebug("ic %p\n", ic);
+
+ /*
+ * Conn is either on a dev's list or on the nodev list.
+ * A race with shutdown() or connect() would cause problems
+ * (since rds_ibdev would change) but that should never happen.
+ */
+ lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
+
+ spin_lock_irq(lock_ptr);
list_del(&ic->ib_node);
+ spin_unlock_irq(lock_ptr);
+
kfree(ic);
}
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 69a6289..81033af 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -139,7 +139,7 @@
return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
}
-int rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
+void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
{
struct rds_ib_connection *ic = conn->c_transport_data;
@@ -148,45 +148,44 @@
BUG_ON(list_empty(&ib_nodev_conns));
BUG_ON(list_empty(&ic->ib_node));
list_del(&ic->ib_node);
- spin_unlock_irq(&ib_nodev_conns_lock);
spin_lock_irq(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
spin_unlock_irq(&rds_ibdev->spinlock);
-
- ic->rds_ibdev = rds_ibdev;
-
- return 0;
-}
-
-void rds_ib_remove_nodev_conns(void)
-{
- struct rds_ib_connection *ic, *_ic;
- LIST_HEAD(tmp_list);
-
- /* avoid calling conn_destroy with irqs off */
- spin_lock_irq(&ib_nodev_conns_lock);
- list_splice(&ib_nodev_conns, &tmp_list);
- INIT_LIST_HEAD(&ib_nodev_conns);
spin_unlock_irq(&ib_nodev_conns_lock);
- list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) {
- if (ic->conn->c_passive)
- rds_conn_destroy(ic->conn->c_passive);
- rds_conn_destroy(ic->conn);
- }
+ ic->rds_ibdev = rds_ibdev;
}
-void rds_ib_remove_conns(struct rds_ib_device *rds_ibdev)
+void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
+{
+ struct rds_ib_connection *ic = conn->c_transport_data;
+
+ /* place conn on nodev_conns_list */
+ spin_lock(&ib_nodev_conns_lock);
+
+ spin_lock_irq(&rds_ibdev->spinlock);
+ BUG_ON(list_empty(&ic->ib_node));
+ list_del(&ic->ib_node);
+ spin_unlock_irq(&rds_ibdev->spinlock);
+
+ list_add_tail(&ic->ib_node, &ib_nodev_conns);
+
+ spin_unlock(&ib_nodev_conns_lock);
+
+ ic->rds_ibdev = NULL;
+}
+
+void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock)
{
struct rds_ib_connection *ic, *_ic;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
- spin_lock_irq(&rds_ibdev->spinlock);
- list_splice(&rds_ibdev->conn_list, &tmp_list);
- INIT_LIST_HEAD(&rds_ibdev->conn_list);
- spin_unlock_irq(&rds_ibdev->spinlock);
+ spin_lock_irq(list_lock);
+ list_splice(list, &tmp_list);
+ INIT_LIST_HEAD(list);
+ spin_unlock_irq(list_lock);
list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) {
if (ic->conn->c_passive)
diff --git a/net/rds/iw.c b/net/rds/iw.c
index 1b56905..b732efb 100644
--- a/net/rds/iw.c
+++ b/net/rds/iw.c
@@ -51,6 +51,7 @@
struct list_head rds_iw_devices;
+/* NOTE: if also grabbing iwdev lock, grab this first */
DEFINE_SPINLOCK(iw_nodev_conns_lock);
LIST_HEAD(iw_nodev_conns);
@@ -145,7 +146,7 @@
}
spin_unlock_irq(&rds_iwdev->spinlock);
- rds_iw_remove_conns(rds_iwdev);
+ rds_iw_destroy_conns(rds_iwdev);
if (rds_iwdev->mr_pool)
rds_iw_destroy_mr_pool(rds_iwdev->mr_pool);
@@ -258,7 +259,7 @@
void rds_iw_exit(void)
{
rds_info_deregister_func(RDS_INFO_IWARP_CONNECTIONS, rds_iw_ic_info);
- rds_iw_remove_nodev_conns();
+ rds_iw_destroy_nodev_conns();
ib_unregister_client(&rds_iw_client);
rds_iw_sysctl_exit();
rds_iw_recv_exit();
diff --git a/net/rds/iw.h b/net/rds/iw.h
index 0ddda34..70eb948 100644
--- a/net/rds/iw.h
+++ b/net/rds/iw.h
@@ -294,9 +294,17 @@
/* ib_rdma.c */
int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id);
-int rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn);
-void rds_iw_remove_nodev_conns(void);
-void rds_iw_remove_conns(struct rds_iw_device *rds_iwdev);
+void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn);
+void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn);
+void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock);
+static inline void rds_iw_destroy_nodev_conns(void)
+{
+ __rds_iw_destroy_conns(&iw_nodev_conns, &iw_nodev_conns_lock);
+}
+static inline void rds_iw_destroy_conns(struct rds_iw_device *rds_iwdev)
+{
+ __rds_iw_destroy_conns(&rds_iwdev->conn_list, &rds_iwdev->spinlock);
+}
struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *);
void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo);
void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *);
diff --git a/net/rds/iw_cm.c b/net/rds/iw_cm.c
index 57ecb3d..0ffaa3e 100644
--- a/net/rds/iw_cm.c
+++ b/net/rds/iw_cm.c
@@ -86,9 +86,7 @@
err = rds_iw_update_cm_id(rds_iwdev, ic->i_cm_id);
if (err)
printk(KERN_ERR "rds_iw_update_ipaddr failed (%d)\n", err);
- err = rds_iw_add_conn(rds_iwdev, conn);
- if (err)
- printk(KERN_ERR "rds_iw_add_conn failed (%d)\n", err);
+ rds_iw_add_conn(rds_iwdev, conn);
/* If the peer gave us the last packet it saw, process this as if
* we had received a regular ACK. */
@@ -637,19 +635,8 @@
* Move connection back to the nodev list.
* Remove cm_id from the device cm_id list.
*/
- if (ic->rds_iwdev) {
-
- spin_lock_irq(&ic->rds_iwdev->spinlock);
- BUG_ON(list_empty(&ic->iw_node));
- list_del(&ic->iw_node);
- spin_unlock_irq(&ic->rds_iwdev->spinlock);
-
- spin_lock_irq(&iw_nodev_conns_lock);
- list_add_tail(&ic->iw_node, &iw_nodev_conns);
- spin_unlock_irq(&iw_nodev_conns_lock);
- rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
- ic->rds_iwdev = NULL;
- }
+ if (ic->rds_iwdev)
+ rds_iw_remove_conn(ic->rds_iwdev, conn);
rdma_destroy_id(ic->i_cm_id);
@@ -726,11 +713,27 @@
return 0;
}
+/*
+ * Free a connection. Connection must be shut down and not set for reconnect.
+ */
void rds_iw_conn_free(void *arg)
{
struct rds_iw_connection *ic = arg;
+ spinlock_t *lock_ptr;
+
rdsdebug("ic %p\n", ic);
+
+ /*
+ * Conn is either on a dev's list or on the nodev list.
+ * A race with shutdown() or connect() would cause problems
+ * (since rds_iwdev would change) but that should never happen.
+ */
+ lock_ptr = ic->rds_iwdev ? &ic->rds_iwdev->spinlock : &iw_nodev_conns_lock;
+
+ spin_lock_irq(lock_ptr);
list_del(&ic->iw_node);
+ spin_unlock_irq(lock_ptr);
+
kfree(ic);
}
diff --git a/net/rds/iw_rdma.c b/net/rds/iw_rdma.c
index 1c02a8f..dcdb37d 100644
--- a/net/rds/iw_rdma.c
+++ b/net/rds/iw_rdma.c
@@ -196,7 +196,7 @@
return rds_iw_add_cm_id(rds_iwdev, cm_id);
}
-int rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
+void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
{
struct rds_iw_connection *ic = conn->c_transport_data;
@@ -205,45 +205,45 @@
BUG_ON(list_empty(&iw_nodev_conns));
BUG_ON(list_empty(&ic->iw_node));
list_del(&ic->iw_node);
- spin_unlock_irq(&iw_nodev_conns_lock);
spin_lock_irq(&rds_iwdev->spinlock);
list_add_tail(&ic->iw_node, &rds_iwdev->conn_list);
spin_unlock_irq(&rds_iwdev->spinlock);
-
- ic->rds_iwdev = rds_iwdev;
-
- return 0;
-}
-
-void rds_iw_remove_nodev_conns(void)
-{
- struct rds_iw_connection *ic, *_ic;
- LIST_HEAD(tmp_list);
-
- /* avoid calling conn_destroy with irqs off */
- spin_lock_irq(&iw_nodev_conns_lock);
- list_splice(&iw_nodev_conns, &tmp_list);
- INIT_LIST_HEAD(&iw_nodev_conns);
spin_unlock_irq(&iw_nodev_conns_lock);
- list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node) {
- if (ic->conn->c_passive)
- rds_conn_destroy(ic->conn->c_passive);
- rds_conn_destroy(ic->conn);
- }
+ ic->rds_iwdev = rds_iwdev;
}
-void rds_iw_remove_conns(struct rds_iw_device *rds_iwdev)
+void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
+{
+ struct rds_iw_connection *ic = conn->c_transport_data;
+
+ /* place conn on nodev_conns_list */
+ spin_lock(&iw_nodev_conns_lock);
+
+ spin_lock_irq(&rds_iwdev->spinlock);
+ BUG_ON(list_empty(&ic->iw_node));
+ list_del(&ic->iw_node);
+ spin_unlock_irq(&rds_iwdev->spinlock);
+
+ list_add_tail(&ic->iw_node, &iw_nodev_conns);
+
+ spin_unlock(&iw_nodev_conns_lock);
+
+ rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
+ ic->rds_iwdev = NULL;
+}
+
+void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock)
{
struct rds_iw_connection *ic, *_ic;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
- spin_lock_irq(&rds_iwdev->spinlock);
- list_splice(&rds_iwdev->conn_list, &tmp_list);
- INIT_LIST_HEAD(&rds_iwdev->conn_list);
- spin_unlock_irq(&rds_iwdev->spinlock);
+ spin_lock_irq(list_lock);
+ list_splice(list, &tmp_list);
+ INIT_LIST_HEAD(list);
+ spin_unlock_irq(list_lock);
list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node) {
if (ic->conn->c_passive)