[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.

Make the in-kernel AFS filesystem use AF_RXRPC instead of the old RxRPC code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 553 insertions, 46 deletions

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index b6dd20a93cc..afc6f0f3025 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1,6 +1,6 @@
 /* internal AFS stuff
  *
- * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -9,48 +9,321 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#ifndef AFS_INTERNAL_H
-#define AFS_INTERNAL_H
-
 #include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
+#include <linux/skbuff.h>
+#include <linux/rxrpc.h>
+#include "afs.h"
+#include "afs_vl.h"
+
+#define AFS_CELL_MAX_ADDRS 15
+
+struct afs_call;
+
+typedef enum {
+	AFS_VL_NEW,			/* new, uninitialised record */
+	AFS_VL_CREATING,		/* creating record */
+	AFS_VL_VALID,			/* record is pending */
+	AFS_VL_NO_VOLUME,		/* no such volume available */
+	AFS_VL_UPDATING,		/* update in progress */
+	AFS_VL_VOLUME_DELETED,		/* volume was deleted */
+	AFS_VL_UNCERTAIN,		/* uncertain state (update failed) */
+} __attribute__((packed)) afs_vlocation_state_t;
 
 /*
- * debug tracing
+ * definition of how to wait for the completion of an operation
  */
-#define kenter(FMT, a...)	printk("==> %s("FMT")\n",__FUNCTION__ , ## a)
-#define kleave(FMT, a...)	printk("<== %s()"FMT"\n",__FUNCTION__ , ## a)
-#define kdebug(FMT, a...)	printk(FMT"\n" , ## a)
-#define kproto(FMT, a...)	printk("### "FMT"\n" , ## a)
-#define knet(FMT, a...)		printk(FMT"\n" , ## a)
-
-#ifdef __KDEBUG
-#define _enter(FMT, a...)	kenter(FMT , ## a)
-#define _leave(FMT, a...)	kleave(FMT , ## a)
-#define _debug(FMT, a...)	kdebug(FMT , ## a)
-#define _proto(FMT, a...)	kproto(FMT , ## a)
-#define _net(FMT, a...)		knet(FMT , ## a)
-#else
-#define _enter(FMT, a...)	do { } while(0)
-#define _leave(FMT, a...)	do { } while(0)
-#define _debug(FMT, a...)	do { } while(0)
-#define _proto(FMT, a...)	do { } while(0)
-#define _net(FMT, a...)		do { } while(0)
-#endif
+struct afs_wait_mode {
+	/* RxRPC received message notification */
+	void (*rx_wakeup)(struct afs_call *call);
 
-static inline void afs_discard_my_signals(void)
-{
-	while (signal_pending(current)) {
-		siginfo_t sinfo;
+	/* synchronous call waiter and call dispatched notification */
+	int (*wait)(struct afs_call *call);
+
+	/* asynchronous call completion */
+	void (*async_complete)(void *reply, int error);
+};
+
+extern const struct afs_wait_mode afs_sync_call;
+extern const struct afs_wait_mode afs_async_call;
+
+/*
+ * a record of an in-progress RxRPC call
+ */
+struct afs_call {
+	const struct afs_call_type *type;	/* type of call */
+	const struct afs_wait_mode *wait_mode;	/* completion wait mode */
+	wait_queue_head_t	waitq;		/* processes awaiting completion */
+	struct work_struct	async_work;	/* asynchronous work processor */
+	struct work_struct	work;		/* actual work processor */
+	struct sk_buff_head	rx_queue;	/* received packets */
+	struct rxrpc_call	*rxcall;	/* RxRPC call handle */
+	struct key		*key;		/* security for this call */
+	struct afs_server	*server;	/* server affected by incoming CM call */
+	void			*request;	/* request data (first part) */
+	void			*request2;	/* request data (second part) */
+	void			*buffer;	/* reply receive buffer */
+	void			*reply;		/* reply buffer (first part) */
+	void			*reply2;	/* reply buffer (second part) */
+	void			*reply3;	/* reply buffer (third part) */
+	enum {					/* call state */
+		AFS_CALL_REQUESTING,	/* request is being sent for outgoing call */
+		AFS_CALL_AWAIT_REPLY,	/* awaiting reply to outgoing call */
+		AFS_CALL_AWAIT_OP_ID,	/* awaiting op ID on incoming call */
+		AFS_CALL_AWAIT_REQUEST,	/* awaiting request data on incoming call */
+		AFS_CALL_REPLYING,	/* replying to incoming call */
+		AFS_CALL_AWAIT_ACK,	/* awaiting final ACK of incoming call */
+		AFS_CALL_COMPLETE,	/* successfully completed */
+		AFS_CALL_BUSY,		/* server was busy */
+		AFS_CALL_ABORTED,	/* call was aborted */
+		AFS_CALL_ERROR,		/* call failed due to error */
+	}			state;
+	int			error;		/* error code */
+	unsigned		request_size;	/* size of request data */
+	unsigned		reply_max;	/* maximum size of reply */
+	unsigned		reply_size;	/* current size of reply */
+	unsigned short		offset;		/* offset into received data store */
+	unsigned char		unmarshall;	/* unmarshalling phase */
+	bool			incoming;	/* T if incoming call */
+	u16			service_id;	/* RxRPC service ID to call */
+	__be16			port;		/* target UDP port */
+	__be32			operation_ID;	/* operation ID for an incoming call */
+	u32			count;		/* count for use in unmarshalling */
+	__be32			tmp;		/* place to extract temporary data */
+};
+
+struct afs_call_type {
+	/* deliver request or reply data to an call
+	 * - returning an error will cause the call to be aborted
+	 */
+	int (*deliver)(struct afs_call *call, struct sk_buff *skb,
+		       bool last);
+
+	/* map an abort code to an error number */
+	int (*abort_to_error)(u32 abort_code);
+
+	/* clean up a call */
+	void (*destructor)(struct afs_call *call);
+};
+
+/*
+ * AFS superblock private data
+ * - there's one superblock per volume
+ */
+struct afs_super_info {
+	struct afs_volume	*volume;	/* volume record */
+	char			rwparent;	/* T if parent is R/W AFS volume */
+};
 
-		spin_lock_irq(&current->sighand->siglock);
-		dequeue_signal(current,&current->blocked, &sinfo);
-		spin_unlock_irq(&current->sighand->siglock);
-	}
+static inline struct afs_super_info *AFS_FS_S(struct super_block *sb)
+{
+	return sb->s_fs_info;
 }
 
+extern struct file_system_type afs_fs_type;
+
+/*
+ * entry in the cached cell catalogue
+ */
+struct afs_cache_cell {
+	char			name[64];	/* cell name (padded with NULs) */
+	struct in_addr		vl_servers[15];	/* cached cell VL servers */
+};
+
+/*
+ * AFS cell record
+ */
+struct afs_cell {
+	atomic_t		usage;
+	struct list_head	link;		/* main cell list link */
+	struct list_head	proc_link;	/* /proc cell list link */
+	struct proc_dir_entry	*proc_dir;	/* /proc dir for this cell */
+#ifdef AFS_CACHING_SUPPORT
+	struct cachefs_cookie	*cache;		/* caching cookie */
+#endif
+
+	/* server record management */
+	rwlock_t		servers_lock;	/* active server list lock */
+	struct list_head	servers;	/* active server list */
+
+	/* volume location record management */
+	struct rw_semaphore	vl_sem;		/* volume management serialisation semaphore */
+	struct list_head	vl_list;	/* cell's active VL record list */
+	spinlock_t		vl_lock;	/* vl_list lock */
+	unsigned short		vl_naddrs;	/* number of VL servers in addr list */
+	unsigned short		vl_curr_svix;	/* current server index */
+	struct in_addr		vl_addrs[AFS_CELL_MAX_ADDRS];	/* cell VL server addresses */
+
+	char			name[0];	/* cell name - must go last */
+};
+
+/*
+ * entry in the cached volume location catalogue
+ */
+struct afs_cache_vlocation {
+	uint8_t			name[64 + 1];	/* volume name (lowercase, padded with NULs) */
+	uint8_t			nservers;	/* number of entries used in servers[] */
+	uint8_t			vidmask;	/* voltype mask for vid[] */
+	uint8_t			srvtmask[8];	/* voltype masks for servers[] */
+#define AFS_VOL_VTM_RW	0x01 /* R/W version of the volume is available (on this server) */
+#define AFS_VOL_VTM_RO	0x02 /* R/O version of the volume is available (on this server) */
+#define AFS_VOL_VTM_BAK	0x04 /* backup version of the volume is available (on this server) */
+
+	afs_volid_t		vid[3];		/* volume IDs for R/W, R/O and Bak volumes */
+	struct in_addr		servers[8];	/* fileserver addresses */
+	time_t			rtime;		/* last retrieval time */
+};
+
+/*
+ * volume -> vnode hash table entry
+ */
+struct afs_cache_vhash {
+	afs_voltype_t		vtype;		/* which volume variation */
+	uint8_t			hash_bucket;	/* which hash bucket this represents */
+} __attribute__((packed));
+
+/*
+ * AFS volume location record
+ */
+struct afs_vlocation {
+	atomic_t		usage;
+	time_t			time_of_death;	/* time at which put reduced usage to 0 */
+	struct list_head	link;		/* link in cell volume location list */
+	struct list_head	grave;		/* link in master graveyard list */
+	struct list_head	update;		/* link in master update list */
+	struct afs_cell		*cell;		/* cell to which volume belongs */
+#ifdef AFS_CACHING_SUPPORT
+	struct cachefs_cookie	*cache;		/* caching cookie */
+#endif
+	struct afs_cache_vlocation vldb;	/* volume information DB record */
+	struct afs_volume	*vols[3];	/* volume access record pointer (index by type) */
+	wait_queue_head_t	waitq;		/* status change waitqueue */
+	time_t			update_at;	/* time at which record should be updated */
+	rwlock_t		lock;		/* access lock */
+	afs_vlocation_state_t	state;		/* volume location state */
+	unsigned short		upd_rej_cnt;	/* ENOMEDIUM count during update */
+	unsigned short		upd_busy_cnt;	/* EBUSY count during update */
+	bool			valid;		/* T if valid */
+};
+
+/*
+ * AFS fileserver record
+ */
+struct afs_server {
+	atomic_t		usage;
+	time_t			time_of_death;	/* time at which put reduced usage to 0 */
+	struct in_addr		addr;		/* server address */
+	struct afs_cell		*cell;		/* cell in which server resides */
+	struct list_head	link;		/* link in cell's server list */
+	struct list_head	grave;		/* link in master graveyard list */
+	struct rb_node		master_rb;	/* link in master by-addr tree */
+	struct rw_semaphore	sem;		/* access lock */
+
+	/* file service access */
+	struct rb_root		fs_vnodes;	/* vnodes backed by this server (ordered by FID) */
+	unsigned long		fs_act_jif;	/* time at which last activity occurred */
+	unsigned long		fs_dead_jif;	/* time at which no longer to be considered dead */
+	spinlock_t		fs_lock;	/* access lock */
+	int			fs_state;      	/* 0 or reason FS currently marked dead (-errno) */
+
+	/* callback promise management */
+	struct rb_root		cb_promises;	/* vnode expiration list (ordered earliest first) */
+	struct delayed_work	cb_updater;	/* callback updater */
+	struct delayed_work	cb_break_work;	/* collected break dispatcher */
+	wait_queue_head_t	cb_break_waitq;	/* space available in cb_break waitqueue */
+	spinlock_t		cb_lock;	/* access lock */
+	struct afs_callback	cb_break[64];	/* ring of callbacks awaiting breaking */
+	atomic_t		cb_break_n;	/* number of pending breaks */
+	u8			cb_break_head;	/* head of callback breaking ring */
+	u8			cb_break_tail;	/* tail of callback breaking ring */
+};
+
+/*
+ * AFS volume access record
+ */
+struct afs_volume {
+	atomic_t		usage;
+	struct afs_cell		*cell;		/* cell to which belongs (unrefd ptr) */
+	struct afs_vlocation	*vlocation;	/* volume location */
+#ifdef AFS_CACHING_SUPPORT
+	struct cachefs_cookie	*cache;		/* caching cookie */
+#endif
+	afs_volid_t		vid;		/* volume ID */
+	afs_voltype_t		type;		/* type of volume */
+	char			type_force;	/* force volume type (suppress R/O -> R/W) */
+	unsigned short		nservers;	/* number of server slots filled */
+	unsigned short		rjservers;	/* number of servers discarded due to -ENOMEDIUM */
+	struct afs_server	*servers[8];	/* servers on which volume resides (ordered) */
+	struct rw_semaphore	server_sem;	/* lock for accessing current server */
+};
+
+/*
+ * vnode catalogue entry
+ */
+struct afs_cache_vnode {
+	afs_vnodeid_t		vnode_id;	/* vnode ID */
+	unsigned		vnode_unique;	/* vnode ID uniquifier */
+	afs_dataversion_t	data_version;	/* data version */
+};
+
+/*
+ * AFS inode private data
+ */
+struct afs_vnode {
+	struct inode		vfs_inode;	/* the VFS's inode record */
+
+	struct afs_volume	*volume;	/* volume on which vnode resides */
+	struct afs_server	*server;	/* server currently supplying this file */
+	struct afs_fid		fid;		/* the file identifier for this inode */
+	struct afs_file_status	status;		/* AFS status info for this file */
+#ifdef AFS_CACHING_SUPPORT
+	struct cachefs_cookie	*cache;		/* caching cookie */
+#endif
+
+	wait_queue_head_t	update_waitq;	/* status fetch waitqueue */
+	unsigned		update_cnt;	/* number of outstanding ops that will update the
+						 * status */
+	spinlock_t		lock;		/* waitqueue/flags lock */
+	unsigned long		flags;
+#define AFS_VNODE_CB_BROKEN	0		/* set if vnode's callback was broken */
+#define AFS_VNODE_CHANGED	1		/* set if vnode's metadata changed */
+#define AFS_VNODE_MODIFIED	2		/* set if vnode's data modified */
+#define AFS_VNODE_ZAP_DATA	3		/* set if vnode's data should be invalidated */
+#define AFS_VNODE_DELETED	4		/* set if vnode deleted on server */
+#define AFS_VNODE_MOUNTPOINT	5		/* set if vnode is a mountpoint symlink */
+#define AFS_VNODE_DIR_CHANGED	6		/* set if vnode's parent dir metadata changed */
+#define AFS_VNODE_DIR_MODIFIED	7		/* set if vnode's parent dir data modified */
+
+	/* outstanding callback notification on this file */
+	struct rb_node		server_rb;	/* link in server->fs_vnodes */
+	struct rb_node		cb_promise;	/* link in server->cb_promises */
+	struct work_struct	cb_broken_work;	/* work to be done on callback break */
+	struct mutex		cb_broken_lock;	/* lock against multiple attempts to fix break */
+//	struct list_head	cb_hash_link;	/* link in master callback hash */
+	time_t			cb_expires;	/* time at which callback expires */
+	time_t			cb_expires_at;	/* time used to order cb_promise */
+	unsigned		cb_version;	/* callback version */
+	unsigned		cb_expiry;	/* callback expiry time */
+	afs_callback_type_t	cb_type;	/* type of callback */
+	bool			cb_promised;	/* true if promise still holds */
+};
+
+/*****************************************************************************/
+/*
+ * callback.c
+ */
+extern void afs_init_callback_state(struct afs_server *);
+extern void afs_broken_callback_work(struct work_struct *);
+extern void afs_break_callbacks(struct afs_server *, size_t,
+				struct afs_callback[]);
+extern void afs_give_up_callback(struct afs_vnode *);
+extern void afs_dispatch_give_up_callbacks(struct work_struct *);
+extern void afs_flush_callback_breaks(struct afs_server *);
+extern int __init afs_callback_update_init(void);
+extern void __exit afs_callback_update_kill(void);
+
 /*
  * cell.c
  */
@@ -60,6 +333,19 @@ extern struct list_head afs_proc_cells;
 extern struct cachefs_index_def afs_cache_cell_index_def;
 #endif
 
+#define afs_get_cell(C) do { atomic_inc(&(C)->usage); } while(0)
+extern int afs_cell_init(char *);
+extern struct afs_cell *afs_cell_create(const char *, char *);
+extern struct afs_cell *afs_cell_lookup(const char *, unsigned);
+extern struct afs_cell *afs_grab_cell(struct afs_cell *);
+extern void afs_put_cell(struct afs_cell *);
+extern void afs_cell_purge(void);
+
+/*
+ * cmservice.c
+ */
+extern bool afs_cm_incoming_call(struct afs_call *);
+
 /*
  * dir.c
  */
@@ -77,9 +363,22 @@ extern int afs_cache_get_page_cookie(struct page *, struct cachefs_page **);
 #endif
 
 /*
+ * fsclient.c
+ */
+extern int afs_fs_fetch_file_status(struct afs_server *,
+				    struct afs_vnode *,
+				    struct afs_volsync *,
+				    const struct afs_wait_mode *);
+extern int afs_fs_give_up_callbacks(struct afs_server *,
+				    const struct afs_wait_mode *);
+extern int afs_fs_fetch_data(struct afs_server *, struct afs_vnode *, off_t,
+			     size_t, struct page *, struct afs_volsync *,
+			     const struct afs_wait_mode *);
+
+/*
  * inode.c
  */
-extern int afs_iget(struct super_block *, struct afs_fid *, struct inode **);
+extern struct inode *afs_iget(struct super_block *, struct afs_fid *);
 extern int afs_inode_getattr(struct vfsmount *, struct dentry *,
 			     struct kstat *);
 extern void afs_clear_inode(struct inode *);
@@ -92,15 +391,20 @@ extern struct cachefs_netfs afs_cache_netfs;
 #endif
 
 /*
+ * misc.c
+ */
+extern int afs_abort_to_error(u32);
+
+/*
  * mntpt.c
  */
 extern const struct inode_operations afs_mntpt_inode_operations;
 extern const struct file_operations afs_mntpt_file_operations;
-extern struct afs_timer afs_mntpt_expiry_timer;
-extern struct afs_timer_ops afs_mntpt_expiry_timer_ops;
 extern unsigned long afs_mntpt_expiry_timeout;
 
 extern int afs_mntpt_check_symlink(struct afs_vnode *);
+extern void afs_mntpt_kill_timer(void);
+extern void afs_umount_begin(struct vfsmount *, int);
 
 /*
  * super.c
@@ -108,16 +412,6 @@ extern int afs_mntpt_check_symlink(struct afs_vnode *);
 extern int afs_fs_init(void);
 extern void afs_fs_exit(void);
 
-#define AFS_CB_HASH_COUNT (PAGE_SIZE / sizeof(struct list_head))
-
-extern struct list_head afs_cb_hash_tbl[];
-extern spinlock_t afs_cb_hash_lock;
-
-#define afs_cb_hash(SRV, FID)						\
-	afs_cb_hash_tbl[((unsigned long)(SRV) +				\
-			 (FID)->vid + (FID)->vnode + (FID)->unique) &	\
-			(AFS_CB_HASH_COUNT - 1)]
-
 /*
  * proc.c
  */
@@ -126,4 +420,217 @@ extern void afs_proc_cleanup(void);
 extern int afs_proc_cell_setup(struct afs_cell *);
 extern void afs_proc_cell_remove(struct afs_cell *);
 
-#endif /* AFS_INTERNAL_H */
+/*
+ * rxrpc.c
+ */
+extern int afs_open_socket(void);
+extern void afs_close_socket(void);
+extern int afs_make_call(struct in_addr *, struct afs_call *, gfp_t,
+			 const struct afs_wait_mode *);
+extern struct afs_call *afs_alloc_flat_call(const struct afs_call_type *,
+					    size_t, size_t);
+extern void afs_flat_call_destructor(struct afs_call *);
+extern void afs_transfer_reply(struct afs_call *, struct sk_buff *);
+extern void afs_send_empty_reply(struct afs_call *);
+extern int afs_extract_data(struct afs_call *, struct sk_buff *, bool, void *,
+			    size_t);
+
+/*
+ * server.c
+ */
+extern spinlock_t afs_server_peer_lock;
+
+#define afs_get_server(S) do { atomic_inc(&(S)->usage); } while(0)
+
+extern struct afs_server *afs_lookup_server(struct afs_cell *,
+					    const struct in_addr *);
+extern struct afs_server *afs_find_server(const struct in_addr *);
+extern void afs_put_server(struct afs_server *);
+extern void __exit afs_purge_servers(void);
+
+/*
+ * vlclient.c
+ */
+#ifdef AFS_CACHING_SUPPORT
+extern struct cachefs_index_def afs_vlocation_cache_index_def;
+#endif
+
+extern int afs_vl_get_entry_by_name(struct in_addr *, const char *,
+				    struct afs_cache_vlocation *,
+				    const struct afs_wait_mode *);
+extern int afs_vl_get_entry_by_id(struct in_addr *, afs_volid_t, afs_voltype_t,
+				  struct afs_cache_vlocation *,
+				  const struct afs_wait_mode *);
+
+/*
+ * vlocation.c
+ */
+#define afs_get_vlocation(V) do { atomic_inc(&(V)->usage); } while(0)
+
+extern int __init afs_vlocation_update_init(void);
+extern struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *,
+						  const char *, size_t);
+extern void afs_put_vlocation(struct afs_vlocation *);
+extern void __exit afs_vlocation_purge(void);
+
+/*
+ * vnode.c
+ */
+#ifdef AFS_CACHING_SUPPORT
+extern struct cachefs_index_def afs_vnode_cache_index_def;
+#endif
+
+extern struct afs_timer_ops afs_vnode_cb_timed_out_ops;
+
+static inline struct afs_vnode *AFS_FS_I(struct inode *inode)
+{
+	return container_of(inode, struct afs_vnode, vfs_inode);
+}
+
+static inline struct inode *AFS_VNODE_TO_I(struct afs_vnode *vnode)
+{
+	return &vnode->vfs_inode;
+}
+
+extern int afs_vnode_fetch_status(struct afs_vnode *);
+extern int afs_vnode_fetch_data(struct afs_vnode *vnode, off_t, size_t,
+				struct page *);
+
+/*
+ * volume.c
+ */
+#ifdef AFS_CACHING_SUPPORT
+extern struct cachefs_index_def afs_volume_cache_index_def;
+#endif
+
+#define afs_get_volume(V) do { atomic_inc(&(V)->usage); } while(0)
+
+extern void afs_put_volume(struct afs_volume *);
+extern struct afs_volume *afs_volume_lookup(const char *, struct afs_cell *,
+					    int);
+extern struct afs_server *afs_volume_pick_fileserver(struct afs_vnode *);
+extern int afs_volume_release_fileserver(struct afs_vnode *,
+					 struct afs_server *, int);
+
+/*****************************************************************************/
+/*
+ * debug tracing
+ */
+extern unsigned afs_debug;
+
+#define dbgprintk(FMT,...) \
+	printk("[%x%-6.6s] "FMT"\n", smp_processor_id(), current->comm ,##__VA_ARGS__)
+
+/* make sure we maintain the format strings, even when debugging is disabled */
+static inline __attribute__((format(printf,1,2)))
+void _dbprintk(const char *fmt, ...)
+{
+}
+
+#define kenter(FMT,...)	dbgprintk("==> %s("FMT")",__FUNCTION__ ,##__VA_ARGS__)
+#define kleave(FMT,...)	dbgprintk("<== %s()"FMT"",__FUNCTION__ ,##__VA_ARGS__)
+#define kdebug(FMT,...)	dbgprintk("    "FMT ,##__VA_ARGS__)
+
+
+#if defined(__KDEBUG)
+#define _enter(FMT,...)	kenter(FMT,##__VA_ARGS__)
+#define _leave(FMT,...)	kleave(FMT,##__VA_ARGS__)
+#define _debug(FMT,...)	kdebug(FMT,##__VA_ARGS__)
+
+#elif defined(CONFIG_AFS_DEBUG)
+#define AFS_DEBUG_KENTER	0x01
+#define AFS_DEBUG_KLEAVE	0x02
+#define AFS_DEBUG_KDEBUG	0x04
+
+#define _enter(FMT,...)					\
+do {							\
+	if (unlikely(afs_debug & AFS_DEBUG_KENTER))	\
+		kenter(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _leave(FMT,...)					\
+do {							\
+	if (unlikely(afs_debug & AFS_DEBUG_KLEAVE))	\
+		kleave(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _debug(FMT,...)					\
+do {							\
+	if (unlikely(afs_debug & AFS_DEBUG_KDEBUG))	\
+		kdebug(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#else
+#define _enter(FMT,...)	_dbprintk("==> %s("FMT")",__FUNCTION__ ,##__VA_ARGS__)
+#define _leave(FMT,...)	_dbprintk("<== %s()"FMT"",__FUNCTION__ ,##__VA_ARGS__)
+#define _debug(FMT,...)	_dbprintk("    "FMT ,##__VA_ARGS__)
+#endif
+
+/*
+ * debug assertion checking
+ */
+#if 1 // defined(__KDEBUGALL)
+
+#define ASSERT(X)						\
+do {								\
+	if (unlikely(!(X))) {					\
+		printk(KERN_ERR "\n");				\
+		printk(KERN_ERR "AFS: Assertion failed\n");	\
+		BUG();						\
+	}							\
+} while(0)
+
+#define ASSERTCMP(X, OP, Y)						\
+do {									\
+	if (unlikely(!((X) OP (Y)))) {					\
+		printk(KERN_ERR "\n");					\
+		printk(KERN_ERR "AFS: Assertion failed\n");		\
+		printk(KERN_ERR "%lu " #OP " %lu is false\n",		\
+		       (unsigned long)(X), (unsigned long)(Y));		\
+		printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",	\
+		       (unsigned long)(X), (unsigned long)(Y));		\
+		BUG();							\
+	}								\
+} while(0)
+
+#define ASSERTIF(C, X)						\
+do {								\
+	if (unlikely((C) && !(X))) {				\
+		printk(KERN_ERR "\n");				\
+		printk(KERN_ERR "AFS: Assertion failed\n");	\
+		BUG();						\
+	}							\
+} while(0)
+
+#define ASSERTIFCMP(C, X, OP, Y)					\
+do {									\
+	if (unlikely((C) && !((X) OP (Y)))) {				\
+		printk(KERN_ERR "\n");					\
+		printk(KERN_ERR "AFS: Assertion failed\n");		\
+		printk(KERN_ERR "%lu " #OP " %lu is false\n",		\
+		       (unsigned long)(X), (unsigned long)(Y));		\
+		printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",	\
+		       (unsigned long)(X), (unsigned long)(Y));		\
+		BUG();							\
+	}								\
+} while(0)
+
+#else
+
+#define ASSERT(X)				\
+do {						\
+} while(0)
+
+#define ASSERTCMP(X, OP, Y)			\
+do {						\
+} while(0)
+
+#define ASSERTIF(C, X)				\
+do {						\
+} while(0)
+
+#define ASSERTIFCMP(C, X, OP, Y)		\
+do {						\
+} while(0)
+
+#endif /* __KDEBUGALL */