cifs: add refcounted and timestamped container for holding tcons

[mv-sheeva.git] / fs / cifs / cifsglob.h

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index c265ebdcd1774c61b1e078b2a07f596e5148e605..cdfd2db4e70d59cf4d01a589c3c099e990e7bec6 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -310,6 +310,44 @@ struct cifsTconInfo {
        /* BB add field for back pointer to sb struct(s)? */
 };
 
+/*
+ * This is a refcounted and timestamped container for a tcon pointer. The
+ * container holds a tcon reference. It is considered safe to free one of
+ * these when the tl_count goes to 0. The tl_time is the time of the last
+ * "get" on the container.
+ */
+struct tcon_link {
+       spinlock_t              tl_lock;
+       u32                     tl_count;
+       u64                     tl_time;
+       struct cifsTconInfo     *tl_tcon;
+};
+
+static inline struct tcon_link *
+cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
+{
+       return (struct tcon_link *)cifs_sb->ptcon;
+}
+
+static inline struct cifsTconInfo *
+tlink_tcon(struct tcon_link *tlink)
+{
+       return (struct cifsTconInfo *)tlink;
+}
+
+static inline void
+cifs_put_tlink(struct tcon_link *tlink)
+{
+       return;
+}
+
+/* This function is always expected to succeed */
+static inline struct cifsTconInfo *
+cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
+{
+       return cifs_sb->ptcon;
+}
+
 /*
  * This info hangs off the cifsFileInfo structure, pointed to by llist.
  * This is used to track byte stream locks on the file
@@ -413,19 +451,6 @@ CIFS_SB(struct super_block *sb)
        return sb->s_fs_info;
 }
 
-static inline struct cifsTconInfo *
-cifs_sb_tcon(struct cifs_sb_info *cifs_sb)
-{
-       return cifs_sb->ptcon;
-}
-
-/* This function is always expected to succeed */
-static inline struct cifsTconInfo *
-cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
-{
-       return cifs_sb->ptcon;
-}
-
 static inline char CIFS_DIR_SEP(const struct cifs_sb_info *cifs_sb)
 {
        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)