Initial import

1 files changed, 298 insertions, 0 deletions

diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
new file mode 100644
index 000000000..437ddb6c4
--- /dev/null
+++ b/include/linux/sunrpc/cache.h
@@ -0,0 +1,298 @@
+/*
+ * include/linux/sunrpc/cache.h
+ *
+ * Generic code for various authentication-related caches
+ * used by sunrpc clients and servers.
+ *
+ * Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au>
+ *
+ * Released under terms in GPL version 2.  See COPYING.
+ *
+ */
+
+#ifndef _LINUX_SUNRPC_CACHE_H_
+#define _LINUX_SUNRPC_CACHE_H_
+
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
+#include <linux/proc_fs.h>
+
+/*
+ * Each cache requires:
+ *  - A 'struct cache_detail' which contains information specific to the cache
+ *    for common code to use.
+ *  - An item structure that must contain a "struct cache_head"
+ *  - A lookup function defined using DefineCacheLookup
+ *  - A 'put' function that can release a cache item. It will only
+ *    be called after cache_put has succeed, so there are guarantee
+ *    to be no references.
+ *  - A function to calculate a hash of an item's key.
+ *
+ * as well as assorted code fragments (e.g. compare keys) and numbers
+ * (e.g. hash size, goal_age, etc).
+ *
+ * Each cache must be registered so that it can be cleaned regularly.
+ * When the cache is unregistered, it is flushed completely.
+ *
+ * Entries have a ref count and a 'hashed' flag which counts the existence
+ * in the hash table.
+ * We only expire entries when refcount is zero.
+ * Existence in the cache is counted  the refcount.
+ */
+
+/* Every cache item has a common header that is used
+ * for expiring and refreshing entries.
+ * 
+ */
+struct cache_head {
+	struct cache_head * next;
+	time_t		expiry_time;	/* After time time, don't use the data */
+	time_t		last_refresh;   /* If CACHE_PENDING, this is when upcall 
+					 * was sent, else this is when update was received
+					 */
+	struct kref	ref;
+	unsigned long	flags;
+};
+#define	CACHE_VALID	0	/* Entry contains valid data */
+#define	CACHE_NEGATIVE	1	/* Negative entry - there is no match for the key */
+#define	CACHE_PENDING	2	/* An upcall has been sent but no reply received yet*/
+#define	CACHE_CLEANED	3	/* Entry has been cleaned from cache */
+
+#define	CACHE_NEW_EXPIRY 120	/* keep new things pending confirmation for 120 seconds */
+
+struct cache_detail_procfs {
+	struct proc_dir_entry	*proc_ent;
+	struct proc_dir_entry   *flush_ent, *channel_ent, *content_ent;
+};
+
+struct cache_detail_pipefs {
+	struct dentry *dir;
+};
+
+struct cache_detail {
+	struct module *		owner;
+	int			hash_size;
+	struct cache_head **	hash_table;
+	rwlock_t		hash_lock;
+
+	atomic_t		inuse; /* active user-space update or lookup */
+
+	char			*name;
+	void			(*cache_put)(struct kref *);
+
+	int			(*cache_upcall)(struct cache_detail *,
+						struct cache_head *);
+
+	void			(*cache_request)(struct cache_detail *cd,
+						 struct cache_head *ch,
+						 char **bpp, int *blen);
+
+	int			(*cache_parse)(struct cache_detail *,
+					       char *buf, int len);
+
+	int			(*cache_show)(struct seq_file *m,
+					      struct cache_detail *cd,
+					      struct cache_head *h);
+	void			(*warn_no_listener)(struct cache_detail *cd,
+					      int has_died);
+
+	struct cache_head *	(*alloc)(void);
+	int			(*match)(struct cache_head *orig, struct cache_head *new);
+	void			(*init)(struct cache_head *orig, struct cache_head *new);
+	void			(*update)(struct cache_head *orig, struct cache_head *new);
+
+	/* fields below this comment are for internal use
+	 * and should not be touched by cache owners
+	 */
+	time_t			flush_time;		/* flush all cache items with last_refresh
+							 * earlier than this */
+	struct list_head	others;
+	time_t			nextcheck;
+	int			entries;
+
+	/* fields for communication over channel */
+	struct list_head	queue;
+
+	atomic_t		readers;		/* how many time is /chennel open */
+	time_t			last_close;		/* if no readers, when did last close */
+	time_t			last_warn;		/* when we last warned about no readers */
+
+	union {
+		struct cache_detail_procfs procfs;
+		struct cache_detail_pipefs pipefs;
+	} u;
+	struct net		*net;
+};
+
+
+/* this must be embedded in any request structure that
+ * identifies an object that will want a callback on
+ * a cache fill
+ */
+struct cache_req {
+	struct cache_deferred_req *(*defer)(struct cache_req *req);
+	int thread_wait;  /* How long (jiffies) we can block the
+			   * current thread to wait for updates.
+			   */
+};
+/* this must be embedded in a deferred_request that is being
+ * delayed awaiting cache-fill
+ */
+struct cache_deferred_req {
+	struct hlist_node	hash;	/* on hash chain */
+	struct list_head	recent; /* on fifo */
+	struct cache_head	*item;  /* cache item we wait on */
+	void			*owner; /* we might need to discard all defered requests
+					 * owned by someone */
+	void			(*revisit)(struct cache_deferred_req *req,
+					   int too_many);
+};
+
+/*
+ * timestamps kept in the cache are expressed in seconds
+ * since boot.  This is the best for measuring differences in
+ * real time.
+ */
+static inline time_t seconds_since_boot(void)
+{
+	struct timespec boot;
+	getboottime(&boot);
+	return get_seconds() - boot.tv_sec;
+}
+
+static inline time_t convert_to_wallclock(time_t sinceboot)
+{
+	struct timespec boot;
+	getboottime(&boot);
+	return boot.tv_sec + sinceboot;
+}
+
+extern const struct file_operations cache_file_operations_pipefs;
+extern const struct file_operations content_file_operations_pipefs;
+extern const struct file_operations cache_flush_operations_pipefs;
+
+extern struct cache_head *
+sunrpc_cache_lookup(struct cache_detail *detail,
+		    struct cache_head *key, int hash);
+extern struct cache_head *
+sunrpc_cache_update(struct cache_detail *detail,
+		    struct cache_head *new, struct cache_head *old, int hash);
+
+extern int
+sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h);
+
+
+extern void cache_clean_deferred(void *owner);
+
+static inline struct cache_head  *cache_get(struct cache_head *h)
+{
+	kref_get(&h->ref);
+	return h;
+}
+
+
+static inline void cache_put(struct cache_head *h, struct cache_detail *cd)
+{
+	if (atomic_read(&h->ref.refcount) <= 2 &&
+	    h->expiry_time < cd->nextcheck)
+		cd->nextcheck = h->expiry_time;
+	kref_put(&h->ref, cd->cache_put);
+}
+
+static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h)
+{
+	return  (h->expiry_time < seconds_since_boot()) ||
+		(detail->flush_time > h->last_refresh);
+}
+
+extern int cache_check(struct cache_detail *detail,
+		       struct cache_head *h, struct cache_req *rqstp);
+extern void cache_flush(void);
+extern void cache_purge(struct cache_detail *detail);
+#define NEVER (0x7FFFFFFF)
+extern void __init cache_initialize(void);
+extern int cache_register_net(struct cache_detail *cd, struct net *net);
+extern void cache_unregister_net(struct cache_detail *cd, struct net *net);
+
+extern struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net);
+extern void cache_destroy_net(struct cache_detail *cd, struct net *net);
+
+extern void sunrpc_init_cache_detail(struct cache_detail *cd);
+extern void sunrpc_destroy_cache_detail(struct cache_detail *cd);
+extern int sunrpc_cache_register_pipefs(struct dentry *parent, const char *,
+					umode_t, struct cache_detail *);
+extern void sunrpc_cache_unregister_pipefs(struct cache_detail *);
+
+extern void qword_add(char **bpp, int *lp, char *str);
+extern void qword_addhex(char **bpp, int *lp, char *buf, int blen);
+extern int qword_get(char **bpp, char *dest, int bufsize);
+
+static inline int get_int(char **bpp, int *anint)
+{
+	char buf[50];
+	char *ep;
+	int rv;
+	int len = qword_get(bpp, buf, sizeof(buf));
+
+	if (len < 0)
+		return -EINVAL;
+	if (len == 0)
+		return -ENOENT;
+
+	rv = simple_strtol(buf, &ep, 0);
+	if (*ep)
+		return -EINVAL;
+
+	*anint = rv;
+	return 0;
+}
+
+static inline int get_uint(char **bpp, unsigned int *anint)
+{
+	char buf[50];
+	int len = qword_get(bpp, buf, sizeof(buf));
+
+	if (len < 0)
+		return -EINVAL;
+	if (len == 0)
+		return -ENOENT;
+
+	if (kstrtouint(buf, 0, anint))
+		return -EINVAL;
+
+	return 0;
+}
+
+static inline int get_time(char **bpp, time_t *time)
+{
+	char buf[50];
+	long long ll;
+	int len = qword_get(bpp, buf, sizeof(buf));
+
+	if (len < 0)
+		return -EINVAL;
+	if (len == 0)
+		return -ENOENT;
+
+	if (kstrtoll(buf, 0, &ll))
+		return -EINVAL;
+
+	*time = (time_t)ll;
+	return 0;
+}
+
+static inline time_t get_expiry(char **bpp)
+{
+	time_t rv;
+	struct timespec boot;
+
+	if (get_time(bpp, &rv))
+		return 0;
+	if (rv < 0)
+		return 0;
+	getboottime(&boot);
+	return rv - boot.tv_sec;
+}
+
+#endif /*  _LINUX_SUNRPC_CACHE_H_ */