cifs: no need to mark smb_ses_list as cifs_demultiplex_thread is exiting

The TCP_Server_Info is refcounted and every SMB session holds a
reference to it. Thus, smb_ses_list is always going to be empty when
cifsd is coming down. This is dead code.

Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 3 insertions, 41 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 9f59887badd2..75b538f50b12 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -346,7 +346,6 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
         struct kvec iov;
         struct socket *csocket = server->ssocket;
         struct list_head *tmp;
-        struct cifsSesInfo *ses;
         struct task_struct *task_to_wake = NULL;
         struct mid_q_entry *mid_entry;
         char temp;
@@ -677,44 +676,19 @@ multi_t2_fnd:
         if (smallbuf) /* no sense logging a debug message if NULL */
                 cifs_small_buf_release(smallbuf);
 
-        /*
-         * BB: we shouldn't have to do any of this. It shouldn't be
-         * possible to exit from the thread with active SMB sessions
-         */
-        spin_lock(&cifs_tcp_ses_lock);
-        if (list_empty(&server->pending_mid_q)) {
-                /* loop through server session structures attached to this and
-                    mark them dead */
-                list_for_each(tmp, &server->smb_ses_list) {
-                        ses = list_entry(tmp, struct cifsSesInfo,
-                                         smb_ses_list);
-                        ses->status = CifsExiting;
-                        ses->server = NULL;
-                }
-                spin_unlock(&cifs_tcp_ses_lock);
-        } else {
-                /* although we can not zero the server struct pointer yet,
-                since there are active requests which may depnd on them,
-                mark the corresponding SMB sessions as exiting too */
-                list_for_each(tmp, &server->smb_ses_list) {
-                        ses = list_entry(tmp, struct cifsSesInfo,
-                                         smb_ses_list);
-                        ses->status = CifsExiting;
-                }
-
+        if (!list_empty(&server->pending_mid_q)) {
                 spin_lock(&GlobalMid_Lock);
                 list_for_each(tmp, &server->pending_mid_q) {
-                mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
+                        mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                         if (mid_entry->midState == MID_REQUEST_SUBMITTED) {
                                 cFYI(1, "Clearing Mid 0x%x - waking up ",
-                                         mid_entry->mid);
+                                        mid_entry->mid);
                                 task_to_wake = mid_entry->tsk;
                                 if (task_to_wake)
                                         wake_up_process(task_to_wake);
                         }
                 }
                 spin_unlock(&GlobalMid_Lock);
-                spin_unlock(&cifs_tcp_ses_lock);
                 /* 1/8th of sec is more than enough time for them to exit */
                 msleep(125);
         }
@@ -732,18 +706,6 @@ multi_t2_fnd:
                 coming home not much else we can do but free the memory */
         }
 
-        /* last chance to mark ses pointers invalid
-        if there are any pointing to this (e.g
-        if a crazy root user tried to kill cifsd
-        kernel thread explicitly this might happen) */
-        /* BB: This shouldn't be necessary, see above */
-        spin_lock(&cifs_tcp_ses_lock);
-        list_for_each(tmp, &server->smb_ses_list) {
-                ses = list_entry(tmp, struct cifsSesInfo, smb_ses_list);
-                ses->server = NULL;
-        }
-        spin_unlock(&cifs_tcp_ses_lock);
-
         kfree(server->hostname);
         task_to_wake = xchg(&server->tsk, NULL);
         kfree(server);