iscsi-target: Drop bogus struct file usage for iSCSI/SCTP

From Al Viro:

	BTW, speaking of struct file treatment related to sockets -
        there's this piece of code in iscsi:
        /*
         * The SCTP stack needs struct socket->file.
         */
        if ((np->np_network_transport == ISCSI_SCTP_TCP) ||
            (np->np_network_transport == ISCSI_SCTP_UDP)) {
                if (!new_sock->file) {
                        new_sock->file = kzalloc(
                                        sizeof(struct file), GFP_KERNEL);

For one thing, as far as I can see it'not true - sctp does *not* depend on
socket->file being non-NULL; it does, in one place, check socket->file->f_flags
for O_NONBLOCK, but there it treats NULL socket->file as "flag not set".
Which is the case here anyway - the fake struct file created in
__iscsi_target_login_thread() (and in iscsi_target_setup_login_socket(), with
the same excuse) do *not* get that flag set.

Moreover, it's a bloody serious violation of a bunch of asserts in VFS;
all struct file instances should come from filp_cachep, via get_empty_filp()
(or alloc_file(), which is a wrapper for it).  FWIW, I'm very tempted to
do this and be done with the entire mess:

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Grover <agrover@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 3 insertions, 19 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 5d56ce44a6c5..97c0f78c3c9c 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -429,19 +429,8 @@ int iscsit_reset_np_thread(
 
 int iscsit_del_np_comm(struct iscsi_np *np)
 {
-        if (!np->np_socket)
-                return 0;
-
-        /*
-         * Some network transports allocate their own struct sock->file,
-         * see  if we need to free any additional allocated resources.
-         */
-        if (np->np_flags & NPF_SCTP_STRUCT_FILE) {
-                kfree(np->np_socket->file);
-                np->np_socket->file = NULL;
-        }
-
-        sock_release(np->np_socket);
+        if (np->np_socket)
+                sock_release(np->np_socket);
         return 0;
 }
 
@@ -4079,13 +4068,8 @@ int iscsit_close_connection(
         kfree(conn->conn_ops);
         conn->conn_ops = NULL;
 
-        if (conn->sock) {
-                if (conn->conn_flags & CONNFLAG_SCTP_STRUCT_FILE) {
-                        kfree(conn->sock->file);
-                        conn->sock->file = NULL;
-                }
+        if (conn->sock)
                 sock_release(conn->sock);
-        }
         conn->thread_set = NULL;
 
         pr_debug("Moving to TARG_CONN_STATE_FREE.\n");