struct export_operations: adjust comments to match current members

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

diff --git a/ipc/util.h b/ipc/util.h
index e3aa2c5c97dc1f996add0ba9e2827c8cca8d7b28..f37d160c98fe7c5c42b44d9611979a4a79d793fc 100644 (file)
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -10,6 +10,8 @@
 #ifndef _IPC_UTIL_H
 #define _IPC_UTIL_H
 
+#include <linux/err.h>
+
 #define USHRT_MAX 0xffff
 #define SEQ_MULTIPLIER (IPCMNI)
 
@@ -17,36 +19,49 @@ 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_id_ary {
-       int size;
-       struct kern_ipc_perm *p[0];
+/*
+ * Structure that holds the parameters needed by the ipc operations
+ * (see after)
+ */
+struct ipc_params {
+       key_t key;
+       int flg;
+       union {
+               size_t size;    /* for shared memories */
+               int nsems;      /* for semaphores */
+       } u;                    /* holds the getnew() specific param */
 };
 
-struct ipc_ids {
-       int in_use;
-       int max_id;
-       unsigned short seq;
-       unsigned short seq_max;
-       struct mutex mutex;
-       struct ipc_id_ary nullentry;
-       struct ipc_id_ary* entries;
+/*
+ * Structure that holds some ipc operations. This structure is used to unify
+ * 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 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
+ */
+struct ipc_ops {
+       int (*getnew) (struct ipc_namespace *, struct ipc_params *);
+       int (*associate) (struct kern_ipc_perm *, int);
+       int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
 };
 
 struct seq_file;
-#ifdef CONFIG_IPC_NS
-#define __ipc_init
-#else
-#define __ipc_init     __init
-#endif
-void __ipc_init ipc_init_ids(struct ipc_ids *ids, int size);
+struct ipc_ids;
+
+void ipc_init_ids(struct ipc_ids *);
 #ifdef CONFIG_PROC_FS
 void __init ipc_init_proc_interface(const char *path, const char *header,
                int ids, int (*show)(struct seq_file *, void *));
@@ -58,14 +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.*/
-int ipc_findkey(struct ipc_ids* ids, key_t key);
-int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
+#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. */
-struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
+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
@@ -83,24 +103,12 @@ void* ipc_rcu_alloc(int size);
 void ipc_rcu_getref(void *ptr);
 void ipc_rcu_putref(void *ptr);
 
-static inline void __ipc_fini_ids(struct ipc_ids *ids,
-               struct ipc_id_ary *entries)
-{
-       if (entries != &ids->nullentry)
-               ipc_rcu_putref(entries);
-}
-
-static inline void ipc_fini_ids(struct ipc_ids *ids)
-{
-       __ipc_fini_ids(ids, ids->entries);
-}
-
-struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
-struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
-void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
-void ipc_unlock(struct kern_ipc_perm* perm);
-int ipc_buildid(struct ipc_ids* ids, int id, int seq);
-int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
+/*
+ * 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);
 
 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);
@@ -116,4 +124,36 @@ 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);
 
+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;
+       return 0;
+}
+
+static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
+{
+       rcu_read_lock();
+       spin_lock(&perm->lock);
+}
+
+static inline void ipc_unlock(struct kern_ipc_perm *perm)
+{
+       spin_unlock(&perm->lock);
+       rcu_read_unlock();
+}
+
+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