LU-5095 hsm: Allow receiving messages to be non-blocking

[fs/lustre-release.git] / libcfs / include / libcfs / libcfs_kernelcomm.h

diff --git a/libcfs/include/libcfs/libcfs_kernelcomm.h b/libcfs/include/libcfs/libcfs_kernelcomm.h
index 8da8c96..0de5cd1 100644 (file)
--- a/libcfs/include/libcfs/libcfs_kernelcomm.h
+++ b/libcfs/include/libcfs/libcfs_kernelcomm.h
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -26,7 +24,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright  2009 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  */
 /*
@@ -37,9 +35,7 @@
  *
  * libcfs/include/libcfs/libcfs_kernelcomm.h
  *
- * Kernel <-> userspace communication routines.  We'll use a shorthand term
- * "lnl" (Lustre NetLink) for this interface name for all arches, even though
- * an implemtation may not use NetLink.
+ * Kernel <-> userspace communication routines.
  * The definitions below are used in the kernel and userspace.
  *
  */
@@ -51,65 +47,76 @@
 #error Do not #include this file directly. #include <libcfs/libcfs.h> instead
 #endif
 
-/* LNL message header.
- * All current and future LNL messages should use this header.
+
+/* KUC message header.
+ * All current and future KUC messages should use this header.
  * To avoid having to include Lustre headers from libcfs, define this here.
  */
-struct lnl_hdr {
-        __u16 lnl_magic;
-        __u8  lnl_transport;  /* Each new Lustre feature should use a different
+struct kuc_hdr {
+        __u16 kuc_magic;
+        __u8  kuc_transport;  /* Each new Lustre feature should use a different
                                  transport */
-        __u8  padding1;
-        __u16 lnl_msgtype;    /* Message type or opcode, transport-specific */
-        __u16 lnl_msglen;
+        __u8  kuc_flags;
+        __u16 kuc_msgtype;    /* Message type or opcode, transport-specific */
+        __u16 kuc_msglen;     /* Including header */
 } __attribute__((aligned(sizeof(__u64))));
 
-#define LNL_MAGIC  0x191C /*Lustre9etLinC */
+#define KUC_CHANGELOG_MSG_MAXSIZE (sizeof(struct kuc_hdr)+CR_MAXSIZE)
 
-/* lnl_msgtype values are defined in each transport */
-enum lnl_transport_type {
-        LNL_TRANSPORT_GENERIC = 1,
-        LNL_TRANSPORT_HSM     = 2,
+#define KUC_MAGIC  0x191C /*Lustre9etLinC */
+#define KUC_FL_BLOCK 0x01   /* Wait for send */
+
+/* kuc_msgtype values are defined in each transport */
+enum kuc_transport_type {
+        KUC_TRANSPORT_GENERIC   = 1,
+        KUC_TRANSPORT_HSM       = 2,
+        KUC_TRANSPORT_CHANGELOG = 3,
 };
 
-enum lnl_generic_message_type {
-        LNL_MSG_SHUTDOWN = 1,
+enum kuc_generic_message_type {
+        KUC_MSG_SHUTDOWN = 1,
 };
 
-/* LNL Broadcast Groups. This determines which userspace process hears which
+/* prototype for callback function on kuc groups */
+typedef int (*libcfs_kkuc_cb_t)(void *data, void *cb_arg);
+
+/* KUC Broadcast Groups. This determines which userspace process hears which
  * messages.  Mutliple transports may be used within a group, or multiple
  * groups may use the same transport.  Broadcast
- * groups need not be used if e.g. a PID is specified instead.
- * Leaving group 0 unassigned at the moment.
+ * groups need not be used if e.g. a UID is specified instead;
+ * use group 0 to signify unicast.
  */
-#define LNL_GRP_HSM           0x02
-#define LNL_GRP_CNT              2
-
-
-#if defined(HAVE_NETLINK) && defined (__KERNEL__)
-extern int libcfs_klnl_start(int transport);
-extern int libcfs_klnl_stop(int transport, int group);
-extern int libcfs_klnl_msg_put(int pid, int group, void *payload);
-#else
-static inline int libcfs_klnl_start(int transport) {
-        return -ENOSYS;
-}
-static inline int libcfs_klnl_stop(int transport, int group) {
-        return 0;
-}
-static inline int libcfs_klnl_msg_put(int pid, int group, void *payload) {
-        return -ENOSYS;
-}
-#endif
+#define KUC_GRP_HSM           0x02
+#define KUC_GRP_MAX           KUC_GRP_HSM
 
-/*
- * NetLink socket number, see include/linux/netlink.h
- * All LNL users share a single netlink socket.  This actually is NetLink
- * specific, but is not to be used outside of the Linux implementation
- * (linux-kernelcomm.c and posix-kernelcomm.c).
- */
-#define LNL_SOCKET 26
+/* Kernel methods */
+extern int libcfs_kkuc_msg_put(struct file *fp, void *payload);
+extern int libcfs_kkuc_group_put(int group, void *payload);
+extern int libcfs_kkuc_group_add(struct file *fp, int uid, int group,
+                                void *data);
+extern int libcfs_kkuc_group_rem(int uid, int group, void **pdata);
+extern int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func,
+                                    void *cb_arg);
+
+#define LK_FLG_STOP 0x01
+#define LK_NOFD -1U
+
+/* kernelcomm control structure, passed from userspace to kernel */
+typedef struct lustre_kernelcomm {
+        __u32 lk_wfd;
+        __u32 lk_rfd;
+        __u32 lk_uid;
+        __u32 lk_group;
+        __u32 lk_data;
+        __u32 lk_flags;
+} __attribute__((packed)) lustre_kernelcomm;
 
+/* Userspace methods */
+extern int libcfs_ukuc_start(lustre_kernelcomm *l, int groups, int rfd_flags);
+extern int libcfs_ukuc_stop(lustre_kernelcomm *l);
+int libcfs_ukuc_get_rfd(lustre_kernelcomm *link);
+extern int libcfs_ukuc_msg_get(lustre_kernelcomm *l, char *buf, int maxsize,
+                               int transport);
 
 #endif /* __LIBCFS_KERNELCOMM_H__ */