From: Paulo Alcantara pc@manguebit.com

[ Upstream commit 7ccc1465465d78e6411b7bd730d06e7435802b5c ]

Call cifs_reconnect() to wake up processes waiting on negotiate protocol to handle the case where server abruptly shut down and had no chance to properly close the socket.

Simple reproducer:

ssh 192.168.2.100 pkill -STOP smbd mount.cifs //192.168.2.100/test /mnt -o ... [never returns]

Cc: Rickard Andersson rickaran@axis.com Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/connect.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index d2307162a2de..e325e06357ff 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -656,6 +656,19 @@ allocate_buffers(struct TCP_Server_Info *server) static bool server_unresponsive(struct TCP_Server_Info *server) { + /* + * If we're in the process of mounting a share or reconnecting a session + * and the server abruptly shut down (e.g. socket wasn't closed, packet + * had been ACK'ed but no SMB response), don't wait longer than 20s to + * negotiate protocol. + */ + spin_lock(&server->srv_lock); + if (server->tcpStatus == CifsInNegotiate && + time_after(jiffies, server->lstrp + 20 * HZ)) { + spin_unlock(&server->srv_lock); + cifs_reconnect(server, false); + return true; + } /* * We need to wait 3 echo intervals to make sure we handle such * situations right: @@ -667,7 +680,6 @@ server_unresponsive(struct TCP_Server_Info *server) * 65s kernel_recvmsg times out, and we see that we haven't gotten * a response in >60s. */ - spin_lock(&server->srv_lock); if ((server->tcpStatus == CifsGood || server->tcpStatus == CifsNeedNegotiate) && (!server->ops->can_echo || server->ops->can_echo(server)) &&