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rds: Make rds_sock_lock BH rather than IRQ safe.

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rds_sock_info() triggers locking warnings because we try to perform a
local_bh_enable() (via sock_i_ino()) while hardware interrupts are
disabled (via taking rds_sock_lock).

There is no reason for rds_sock_lock to be a hardware IRQ disabling
lock, none of these access paths run in hardware interrupt context.

Therefore making it a BH disabling lock is safe and sufficient to
fix this bug.

Reported-by: Kumar Sanghvi <kumaras@chelsio.com>
Reported-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2012-01-24 17:03:44 -05:00
parent 36a1211970
commit efc3dbc374
1 changed files with 8 additions and 12 deletions
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20
net/rds/af_rds.c
View file

@ -68,7 +68,6 @@ static int rds_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct rds_sock *rs;
unsigned long flags;
if (!sk)
goto out;
@ -94,10 +93,10 @@ static int rds_release(struct socket *sock)
rds_rdma_drop_keys(rs);
rds_notify_queue_get(rs, NULL);
spin_lock_irqsave(&rds_sock_lock, flags);
spin_lock_bh(&rds_sock_lock);
list_del_init(&rs->rs_item);
rds_sock_count--;
spin_unlock_irqrestore(&rds_sock_lock, flags);
spin_unlock_bh(&rds_sock_lock);
rds_trans_put(rs->rs_transport);
@ -409,7 +408,6 @@ static const struct proto_ops rds_proto_ops = {
static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
{
unsigned long flags;
struct rds_sock *rs;
sock_init_data(sock, sk);
@ -426,10 +424,10 @@ static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
spin_lock_init(&rs->rs_rdma_lock);
rs->rs_rdma_keys = RB_ROOT;
spin_lock_irqsave(&rds_sock_lock, flags);
spin_lock_bh(&rds_sock_lock);
list_add_tail(&rs->rs_item, &rds_sock_list);
rds_sock_count++;
spin_unlock_irqrestore(&rds_sock_lock, flags);
spin_unlock_bh(&rds_sock_lock);
return 0;
}
@ -471,12 +469,11 @@ static void rds_sock_inc_info(struct socket *sock, unsigned int len,
{
struct rds_sock *rs;
struct rds_incoming *inc;
unsigned long flags;
unsigned int total = 0;
len /= sizeof(struct rds_info_message);
spin_lock_irqsave(&rds_sock_lock, flags);
spin_lock_bh(&rds_sock_lock);
list_for_each_entry(rs, &rds_sock_list, rs_item) {
read_lock(&rs->rs_recv_lock);
@ -492,7 +489,7 @@ static void rds_sock_inc_info(struct socket *sock, unsigned int len,
read_unlock(&rs->rs_recv_lock);
}
spin_unlock_irqrestore(&rds_sock_lock, flags);
spin_unlock_bh(&rds_sock_lock);
lens->nr = total;
lens->each = sizeof(struct rds_info_message);
@ -504,11 +501,10 @@ static void rds_sock_info(struct socket *sock, unsigned int len,
{
struct rds_info_socket sinfo;
struct rds_sock *rs;
unsigned long flags;
len /= sizeof(struct rds_info_socket);
spin_lock_irqsave(&rds_sock_lock, flags);
spin_lock_bh(&rds_sock_lock);
if (len < rds_sock_count)
goto out;
@ -529,7 +525,7 @@ static void rds_sock_info(struct socket *sock, unsigned int len,
lens->nr = rds_sock_count;
lens->each = sizeof(struct rds_info_socket);
spin_unlock_irqrestore(&rds_sock_lock, flags);
spin_unlock_bh(&rds_sock_lock);
}
static void rds_exit(void)