Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...

[sfrench/cifs-2.6.git] / ipc / util.h

diff --git a/ipc/util.h b/ipc/util.h
index 2a03d8cc6a01423bbb1cb9ce9289d79c3afa8cae..f37d160c98fe7c5c42b44d9611979a4a79d793fc 100644 (file)
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -10,7 +10,6 @@
 #ifndef _IPC_UTIL_H
 #define _IPC_UTIL_H
 
-#include <linux/idr.h>
 #include <linux/err.h>
 
 #define USHRT_MAX 0xffff
@@ -20,22 +19,16 @@ void sem_init (void);
 void msg_init (void);
 void shm_init (void);
 
-int sem_init_ns(struct ipc_namespace *ns);
-int msg_init_ns(struct ipc_namespace *ns);
-int shm_init_ns(struct ipc_namespace *ns);
+struct ipc_namespace;
+
+void sem_init_ns(struct ipc_namespace *ns);
+void msg_init_ns(struct ipc_namespace *ns);
+void shm_init_ns(struct ipc_namespace *ns);
 
 void sem_exit_ns(struct ipc_namespace *ns);
 void msg_exit_ns(struct ipc_namespace *ns);
 void shm_exit_ns(struct ipc_namespace *ns);
 
-struct ipc_ids {
-       int in_use;
-       unsigned short seq;
-       unsigned short seq_max;
-       struct mutex mutex;
-       struct idr ipcs_idr;
-};
-
 /*
  * Structure that holds the parameters needed by the ipc operations
  * (see after)
@@ -54,7 +47,7 @@ struct ipc_params {
  * the calls to sys_msgget(), sys_semget(), sys_shmget()
  *      . routine to call to create a new ipc object. Can be one of newque,
  *        newary, newseg
- *      . routine to call to call to check permissions for a new ipc object.
+ *      . routine to call to check permissions for a new ipc object.
  *        Can be one of security_msg_associate, security_sem_associate,
  *        security_shm_associate
  *      . routine to call for an extra check if needed
@@ -66,6 +59,7 @@ struct ipc_ops {
 };
 
 struct seq_file;
+struct ipc_ids;
 
 void ipc_init_ids(struct ipc_ids *);
 #ifdef CONFIG_PROC_FS
@@ -79,14 +73,19 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
 #define IPC_MSG_IDS    1
 #define IPC_SHM_IDS    2
 
-/* must be called with ids->mutex acquired.*/
+#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+
+/* must be called with ids->rw_mutex acquired for writing */
 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
+
+/* must be called with ids->rw_mutex acquired for reading */
 int ipc_get_maxid(struct ipc_ids *);
 
 /* must be called with both locks acquired. */
 void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
 
-int ipcperms (struct kern_ipc_perm *ipcp, short flg);
+/* must be called with ipcp locked */
+int ipcperms(struct kern_ipc_perm *ipcp, short flg);
 
 /* for rare, potentially huge allocations.
  * both function can sleep
@@ -104,8 +103,12 @@ void* ipc_rcu_alloc(int size);
 void ipc_rcu_getref(void *ptr);
 void ipc_rcu_putref(void *ptr);
 
+/*
+ * ipc_lock_down: called with rw_mutex held
+ * ipc_lock: called without that lock held
+ */
+struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *, int);
 struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
-int ipc_buildid(struct ipc_ids* ids, int id, int seq);
 
 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
@@ -120,13 +123,16 @@ int ipc_parse_version (int *cmd);
 extern void free_msg(struct msg_msg *msg);
 extern struct msg_msg *load_msg(const void __user *src, int len);
 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
-extern int ipcget_new(struct ipc_namespace *, struct ipc_ids *,
-                       struct ipc_ops *, struct ipc_params *);
-extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *,
-                       struct ipc_ops *, struct ipc_params *);
 
-static inline int ipc_checkid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp,
-                               int uid)
+static inline int ipc_buildid(int id, int seq)
+{
+       return SEQ_MULTIPLIER * seq + id;
+}
+
+/*
+ * Must be called with ipcp locked
+ */
+static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
 {
        if (uid / SEQ_MULTIPLIER != ipcp->seq)
                return 1;
@@ -145,30 +151,9 @@ static inline void ipc_unlock(struct kern_ipc_perm *perm)
        rcu_read_unlock();
 }
 
-static inline struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids,
-                                               int id)
-{
-       struct kern_ipc_perm *out;
-
-       out = ipc_lock(ids, id);
-       if (IS_ERR(out))
-               return out;
-
-       if (ipc_checkid(ids, out, id)) {
-               ipc_unlock(out);
-               return ERR_PTR(-EIDRM);
-       }
-
-       return out;
-}
-
-static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
-                       struct ipc_ops *ops, struct ipc_params *params)
-{
-       if (params->key == IPC_PRIVATE)
-               return ipcget_new(ns, ids, ops, params);
-       else
-               return ipcget_public(ns, ids, ops, params);
-}
+struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id);
+struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
+int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
+                       struct ipc_ops *ops, struct ipc_params *params);
 
 #endif