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>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 9f59887..75b538f 100644 (file)
--- 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);