cifs: reinstate sharing of SMB sessions sans races
We do this by abandoning the global list of SMB sessions and instead
moving to a per-server list. This entails adding a new list head to the
TCP_Server_Info struct. The refcounting for the cifsSesInfo is moved to
a non-atomic variable. We have to protect it by a lock anyway, so there's
no benefit to making it an atomic. The list and refcount are protected
by the global cifs_tcp_ses_lock.
The patch also adds a new routines to find and put SMB sessions and
that properly take and put references under the lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 313f7bf..631a99f 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -195,14 +195,14 @@
* Session structure. One of these for each uid session with a particular host
*/
struct cifsSesInfo {
- struct list_head cifsSessionList;
+ struct list_head smb_ses_list;
struct list_head tcon_list;
struct semaphore sesSem;
#if 0
struct cifsUidInfo *uidInfo; /* pointer to user info */
#endif
struct TCP_Server_Info *server; /* pointer to server info */
- atomic_t inUse; /* # of mounts (tree connections) on this ses */
+ int ses_count; /* reference counter */
enum statusEnum status;
unsigned overrideSecFlg; /* if non-zero override global sec flags */
__u16 ipc_tid; /* special tid for connection to IPC share */
@@ -602,8 +602,6 @@
/* protects cifs_tcp_ses_list and srv_count for each tcp session */
GLOBAL_EXTERN rwlock_t cifs_tcp_ses_lock;
-
-GLOBAL_EXTERN struct list_head GlobalSMBSessionList; /* BB to be removed by jl*/
GLOBAL_EXTERN struct list_head GlobalTreeConnectionList; /* BB to be removed */
GLOBAL_EXTERN rwlock_t GlobalSMBSeslock; /* protects list inserts on 3 above */