[CIFS] Fix cifs reconnection flags

In preparation for Jeff's big umount/mount fixes to remove the possibility of
various races in cifs mount and linked list handling of sessions, sockets and
tree connections, this patch cleans up some repetitive code in cifs_mount,
and addresses a problem with ses->status and tcon->tidStatus in which we
were overloading the "need_reconnect" state with other status in that
field.  So the "need_reconnect" flag has been broken out from those
two state fields (need reconnect was not mutually exclusive from some of the
other possible tid and ses states).  In addition, a few exit cases in
cifs_mount were cleaned up, and a problem with a tcon flag (for lease support)
was not being set consistently for the 2nd mount of the same share

CC: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 22 insertions, 18 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index d5eac48fc415..7f0651b69573 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -190,10 +190,10 @@ small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
                 /* need to prevent multiple threads trying to
                 simultaneously reconnect the same SMB session */
                         down(&tcon->ses->sesSem);
-                        if (tcon->ses->status == CifsNeedReconnect)
+                        if (tcon->ses->need_reconnect)
                                 rc = cifs_setup_session(0, tcon->ses,
                                                         nls_codepage);
-                        if (!rc && (tcon->tidStatus == CifsNeedReconnect)) {
+                        if (!rc && (tcon->need_reconnect)) {
                                 mark_open_files_invalid(tcon);
                                 rc = CIFSTCon(0, tcon->ses, tcon->treeName,
                                               tcon, nls_codepage);
@@ -295,7 +295,7 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
            check for tcp and smb session status done differently
            for those three - in the calling routine */
         if (tcon) {
-                if (tcon->tidStatus == CifsExiting) {
+                if (tcon->need_reconnect) {
                         /* only tree disconnect, open, and write,
                           (and ulogoff which does not have tcon)
                           are allowed as we start force umount */
@@ -337,10 +337,10 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
                 /* need to prevent multiple threads trying to
                 simultaneously reconnect the same SMB session */
                         down(&tcon->ses->sesSem);
-                        if (tcon->ses->status == CifsNeedReconnect)
+                        if (tcon->ses->need_reconnect)
                                 rc = cifs_setup_session(0, tcon->ses,
                                                         nls_codepage);
-                        if (!rc && (tcon->tidStatus == CifsNeedReconnect)) {
+                        if (!rc && (tcon->need_reconnect)) {
                                 mark_open_files_invalid(tcon);
                                 rc = CIFSTCon(0, tcon->ses, tcon->treeName,
                                               tcon, nls_codepage);
@@ -759,7 +759,7 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
 
         /* No need to return error on this operation if tid invalidated and
         closed on server already e.g. due to tcp session crashing */
-        if (tcon->tidStatus == CifsNeedReconnect) {
+        if (tcon->need_reconnect) {
                 up(&tcon->tconSem);
                 return 0;
         }
@@ -806,32 +806,36 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
                 up(&ses->sesSem);
                 return -EBUSY;
         }
+
+        if (ses->server == NULL)
+                return -EIO;
+
+        if (ses->need_reconnect)
+                goto session_already_dead; /* no need to send SMBlogoff if uid
+                                              already closed due to reconnect */
         rc = small_smb_init(SMB_COM_LOGOFF_ANDX, 2, NULL, (void **)&pSMB);
         if (rc) {
                 up(&ses->sesSem);
                 return rc;
         }
 
-        if (ses->server) {
-                pSMB->hdr.Mid = GetNextMid(ses->server);
+        pSMB->hdr.Mid = GetNextMid(ses->server);
 
-                if (ses->server->secMode &
+        if (ses->server->secMode &
                    (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
                         pSMB->hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
-        }
 
         pSMB->hdr.Uid = ses->Suid;
 
         pSMB->AndXCommand = 0xFF;
         rc = SendReceiveNoRsp(xid, ses, (struct smb_hdr *) pSMB, 0);
-        if (ses->server) {
-                atomic_dec(&ses->server->socketUseCount);
-                if (atomic_read(&ses->server->socketUseCount) == 0) {
-                        spin_lock(&GlobalMid_Lock);
-                        ses->server->tcpStatus = CifsExiting;
-                        spin_unlock(&GlobalMid_Lock);
-                        rc = -ESHUTDOWN;
-                }
+session_already_dead:
+        atomic_dec(&ses->server->socketUseCount);
+        if (atomic_read(&ses->server->socketUseCount) == 0) {
+                spin_lock(&GlobalMid_Lock);
+                ses->server->tcpStatus = CifsExiting;
+                spin_unlock(&GlobalMid_Lock);
+                rc = -ESHUTDOWN;
         }
         up(&ses->sesSem);