diff options
Diffstat (limited to 'include/linux/sunrpc/cache.h')
| -rw-r--r-- | include/linux/sunrpc/cache.h | 163 |
1 files changed, 103 insertions, 60 deletions
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h index 6ce690de447f..e783132e481f 100644 --- a/include/linux/sunrpc/cache.h +++ b/include/linux/sunrpc/cache.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * include/linux/sunrpc/cache.h * @@ -5,9 +6,6 @@ * 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_ @@ -16,6 +14,7 @@ #include <linux/kref.h> #include <linux/slab.h> #include <linux/atomic.h> +#include <linux/kstrtox.h> #include <linux/proc_fs.h> /* @@ -46,37 +45,33 @@ * */ 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 hlist_node cache_list; + time64_t expiry_time; /* After time expiry_time, don't use + * the data */ + time64_t last_refresh; /* If CACHE_PENDING, this is when upcall was + * sent, else this is when update was + * received, though it is alway set to + * be *after* ->flush_time. */ 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; +/* cache_head.flags */ +enum { + CACHE_VALID, /* Entry contains valid data */ + CACHE_NEGATIVE, /* Negative entry - there is no match for the key */ + CACHE_PENDING, /* An upcall has been sent but no reply received yet*/ + CACHE_CLEANED, /* Entry has been cleaned from cache */ }; -struct cache_detail_pipefs { - struct dentry *dir; -}; +#define CACHE_NEW_EXPIRY 120 /* keep new things pending confirmation for 120 seconds */ 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 */ + struct hlist_head * hash_table; + spinlock_t hash_lock; char *name; void (*cache_put)(struct kref *); @@ -98,6 +93,7 @@ struct cache_detail { int has_died); struct cache_head * (*alloc)(void); + void (*flush)(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); @@ -105,37 +101,41 @@ struct cache_detail { /* 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 */ + time64_t flush_time; /* flush all cache items with + * last_refresh at or earlier + * than this. last_refresh + * is never set at or earlier + * than this. + */ struct list_head others; - time_t nextcheck; + time64_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 */ + atomic_t writers; /* how many time is /channel open */ + time64_t last_close; /* if no writers, when did last close */ + time64_t last_warn; /* when we last warned about no writers */ union { - struct cache_detail_procfs procfs; - struct cache_detail_pipefs pipefs; - } u; + struct proc_dir_entry *procfs; + struct dentry *pipefs; + }; 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. - */ + unsigned long 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 */ @@ -153,18 +153,22 @@ struct cache_deferred_req { * timestamps kept in the cache are expressed in seconds * since boot. This is the best for measuring differences in * real time. + * This reimplemnts ktime_get_boottime_seconds() in a slightly + * faster but less accurate way. When we end up converting + * back to wallclock (CLOCK_REALTIME), that error often + * cancels out during the reverse operation. */ -static inline time_t seconds_since_boot(void) +static inline time64_t seconds_since_boot(void) { - struct timespec boot; - getboottime(&boot); - return get_seconds() - boot.tv_sec; + struct timespec64 boot; + getboottime64(&boot); + return ktime_get_real_seconds() - boot.tv_sec; } -static inline time_t convert_to_wallclock(time_t sinceboot) +static inline time64_t convert_to_wallclock(time64_t sinceboot) { - struct timespec boot; - getboottime(&boot); + struct timespec64 boot; + getboottime64(&boot); return boot.tv_sec + sinceboot; } @@ -173,14 +177,17 @@ 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); +sunrpc_cache_lookup_rcu(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 int +sunrpc_cache_pipe_upcall_timeout(struct cache_detail *detail, + struct cache_head *h); extern void cache_clean_deferred(void *owner); @@ -191,21 +198,32 @@ static inline struct cache_head *cache_get(struct cache_head *h) return h; } +static inline struct cache_head *cache_get_rcu(struct cache_head *h) +{ + if (kref_get_unless_zero(&h->ref)) + return h; + return NULL; +} static inline void cache_put(struct cache_head *h, struct cache_detail *cd) { - if (atomic_read(&h->ref.refcount) <= 2 && + if (kref_read(&h->ref) <= 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) +static inline bool cache_is_expired(struct cache_detail *detail, struct cache_head *h) { - return (h->expiry_time < seconds_since_boot()) || - (detail->flush_time > h->last_refresh); + if (h->expiry_time < seconds_since_boot()) + return true; + if (!test_bit(CACHE_VALID, &h->flags)) + return false; + return detail->flush_time >= h->last_refresh; } +extern int cache_check_rcu(struct cache_detail *detail, + struct cache_head *h, struct cache_req *rqstp); extern int cache_check(struct cache_detail *detail, struct cache_head *h, struct cache_req *rqstp); extern void cache_flush(void); @@ -215,7 +233,7 @@ 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 struct cache_detail *cache_create_net(const 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); @@ -223,6 +241,12 @@ 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 sunrpc_cache_unhash(struct cache_detail *, struct cache_head *); + +/* Must store cache_detail in seq_file->private if using next three functions */ +extern void *cache_seq_start_rcu(struct seq_file *file, loff_t *pos); +extern void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos); +extern void cache_seq_stop_rcu(struct seq_file *file, void *p); extern void qword_add(char **bpp, int *lp, char *str); extern void qword_addhex(char **bpp, int *lp, char *buf, int blen); @@ -264,17 +288,36 @@ static inline int get_uint(char **bpp, unsigned int *anint) return 0; } -static inline time_t get_expiry(char **bpp) +static inline int get_time(char **bpp, time64_t *time) { - int rv; - struct timespec boot; - - if (get_int(bpp, &rv)) - return 0; - if (rv < 0) - return 0; - getboottime(&boot); - return rv - boot.tv_sec; + 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 = ll; + return 0; +} + +static inline int get_expiry(char **bpp, time64_t *rvp) +{ + int error; + struct timespec64 boot; + + error = get_time(bpp, rvp); + if (error) + return error; + + getboottime64(&boot); + (*rvp) -= boot.tv_sec; + return 0; } #endif /* _LINUX_SUNRPC_CACHE_H_ */ |