diff options
| author | santosh.shilimkar@oracle.com <santosh.shilimkar@oracle.com> | 2015-08-23 00:45:33 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-08-25 22:35:31 +0200 |
| commit | dfcec251d22bab947d10cf37e9ad67085cf7f097 (patch) | |
| tree | dd9ef3f30a176b7aebe4dd24f9c73a1ff49939a9 /net/rds | |
| parent | RDS: Don't destroy the rdma id until after we're done using it (diff) | |
| download | linux-dfcec251d22bab947d10cf37e9ad67085cf7f097.tar.xz linux-dfcec251d22bab947d10cf37e9ad67085cf7f097.zip | |
RDS: make sure rds_send_drop_to properly takes the m_rs_lock
rds_send_drop_to() is used during socket tear down to find all the
messages on the socket and flush them . It can race with the
acking code unless it takes the m_rs_lock on each and every message.
This plugs a hole where we didn't take m_rs_lock on any message that
didn't have the RDS_MSG_ON_CONN set. Taking m_rs_lock avoids
double frees and other memory corruptions as the ack code trusts
the message m_rs pointer on a socket that had actually been freed.
We must take m_rs_lock to access m_rs. Because of lock nesting and
rs access, we also need to acquire rs_lock.
Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds')
| -rw-r--r-- | net/rds/send.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/net/rds/send.c b/net/rds/send.c index faad1be61ab6..b40c2ea8e89a 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -778,8 +778,22 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) while (!list_empty(&list)) { rm = list_entry(list.next, struct rds_message, m_sock_item); list_del_init(&rm->m_sock_item); - rds_message_wait(rm); + + /* just in case the code above skipped this message + * because RDS_MSG_ON_CONN wasn't set, run it again here + * taking m_rs_lock is the only thing that keeps us + * from racing with ack processing. + */ + spin_lock_irqsave(&rm->m_rs_lock, flags); + + spin_lock(&rs->rs_lock); + __rds_send_complete(rs, rm, RDS_RDMA_CANCELED); + spin_unlock(&rs->rs_lock); + + rm->m_rs = NULL; + spin_unlock_irqrestore(&rm->m_rs_lock, flags); + rds_message_put(rm); } } |