![J. Bruce Fields](/assets/img/avatar_default.png)
Just some minor cleanup. Also I don't see much point in trying to register further proc entries if initial entries fail; so just stop trying in that case. Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
1302 lines
30 KiB
C
1302 lines
30 KiB
C
/*
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* net/sunrpc/cache.c
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*
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* Generic code for various authentication-related caches
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* used by sunrpc clients and servers.
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*
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* Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au>
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*
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* Released under terms in GPL version 2. See COPYING.
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*
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*/
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#include <linux/types.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kmod.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/ctype.h>
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#include <asm/uaccess.h>
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#include <linux/poll.h>
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#include <linux/seq_file.h>
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#include <linux/proc_fs.h>
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#include <linux/net.h>
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#include <linux/workqueue.h>
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#include <linux/mutex.h>
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#include <asm/ioctls.h>
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#include <linux/sunrpc/types.h>
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#include <linux/sunrpc/cache.h>
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#include <linux/sunrpc/stats.h>
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#define RPCDBG_FACILITY RPCDBG_CACHE
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static int cache_defer_req(struct cache_req *req, struct cache_head *item);
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static void cache_revisit_request(struct cache_head *item);
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static void cache_init(struct cache_head *h)
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{
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time_t now = get_seconds();
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h->next = NULL;
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h->flags = 0;
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kref_init(&h->ref);
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h->expiry_time = now + CACHE_NEW_EXPIRY;
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h->last_refresh = now;
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}
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struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
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struct cache_head *key, int hash)
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{
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struct cache_head **head, **hp;
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struct cache_head *new = NULL;
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head = &detail->hash_table[hash];
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read_lock(&detail->hash_lock);
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for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
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struct cache_head *tmp = *hp;
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if (detail->match(tmp, key)) {
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cache_get(tmp);
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read_unlock(&detail->hash_lock);
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return tmp;
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}
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}
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read_unlock(&detail->hash_lock);
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/* Didn't find anything, insert an empty entry */
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new = detail->alloc();
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if (!new)
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return NULL;
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/* must fully initialise 'new', else
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* we might get lose if we need to
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* cache_put it soon.
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*/
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cache_init(new);
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detail->init(new, key);
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write_lock(&detail->hash_lock);
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/* check if entry appeared while we slept */
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for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
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struct cache_head *tmp = *hp;
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if (detail->match(tmp, key)) {
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cache_get(tmp);
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write_unlock(&detail->hash_lock);
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cache_put(new, detail);
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return tmp;
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}
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}
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new->next = *head;
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*head = new;
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detail->entries++;
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cache_get(new);
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write_unlock(&detail->hash_lock);
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return new;
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}
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EXPORT_SYMBOL(sunrpc_cache_lookup);
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static void queue_loose(struct cache_detail *detail, struct cache_head *ch);
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static int cache_fresh_locked(struct cache_head *head, time_t expiry)
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{
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head->expiry_time = expiry;
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head->last_refresh = get_seconds();
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return !test_and_set_bit(CACHE_VALID, &head->flags);
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}
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static void cache_fresh_unlocked(struct cache_head *head,
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struct cache_detail *detail, int new)
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{
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if (new)
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cache_revisit_request(head);
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if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
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cache_revisit_request(head);
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queue_loose(detail, head);
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}
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}
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struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
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struct cache_head *new, struct cache_head *old, int hash)
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{
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/* The 'old' entry is to be replaced by 'new'.
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* If 'old' is not VALID, we update it directly,
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* otherwise we need to replace it
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*/
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struct cache_head **head;
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struct cache_head *tmp;
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int is_new;
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if (!test_bit(CACHE_VALID, &old->flags)) {
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write_lock(&detail->hash_lock);
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if (!test_bit(CACHE_VALID, &old->flags)) {
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if (test_bit(CACHE_NEGATIVE, &new->flags))
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set_bit(CACHE_NEGATIVE, &old->flags);
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else
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detail->update(old, new);
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is_new = cache_fresh_locked(old, new->expiry_time);
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write_unlock(&detail->hash_lock);
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cache_fresh_unlocked(old, detail, is_new);
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return old;
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}
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write_unlock(&detail->hash_lock);
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}
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/* We need to insert a new entry */
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tmp = detail->alloc();
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if (!tmp) {
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cache_put(old, detail);
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return NULL;
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}
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cache_init(tmp);
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detail->init(tmp, old);
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head = &detail->hash_table[hash];
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write_lock(&detail->hash_lock);
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if (test_bit(CACHE_NEGATIVE, &new->flags))
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set_bit(CACHE_NEGATIVE, &tmp->flags);
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else
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detail->update(tmp, new);
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tmp->next = *head;
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*head = tmp;
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detail->entries++;
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cache_get(tmp);
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is_new = cache_fresh_locked(tmp, new->expiry_time);
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cache_fresh_locked(old, 0);
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write_unlock(&detail->hash_lock);
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cache_fresh_unlocked(tmp, detail, is_new);
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cache_fresh_unlocked(old, detail, 0);
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cache_put(old, detail);
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return tmp;
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}
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EXPORT_SYMBOL(sunrpc_cache_update);
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static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h);
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/*
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* This is the generic cache management routine for all
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* the authentication caches.
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* It checks the currency of a cache item and will (later)
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* initiate an upcall to fill it if needed.
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*
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*
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* Returns 0 if the cache_head can be used, or cache_puts it and returns
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* -EAGAIN if upcall is pending,
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* -ETIMEDOUT if upcall failed and should be retried,
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* -ENOENT if cache entry was negative
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*/
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int cache_check(struct cache_detail *detail,
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struct cache_head *h, struct cache_req *rqstp)
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{
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int rv;
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long refresh_age, age;
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/* First decide return status as best we can */
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if (!test_bit(CACHE_VALID, &h->flags) ||
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h->expiry_time < get_seconds())
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rv = -EAGAIN;
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else if (detail->flush_time > h->last_refresh)
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rv = -EAGAIN;
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else {
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/* entry is valid */
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if (test_bit(CACHE_NEGATIVE, &h->flags))
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rv = -ENOENT;
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else rv = 0;
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}
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/* now see if we want to start an upcall */
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refresh_age = (h->expiry_time - h->last_refresh);
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age = get_seconds() - h->last_refresh;
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if (rqstp == NULL) {
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if (rv == -EAGAIN)
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rv = -ENOENT;
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} else if (rv == -EAGAIN || age > refresh_age/2) {
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dprintk("RPC: Want update, refage=%ld, age=%ld\n",
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refresh_age, age);
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if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
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switch (cache_make_upcall(detail, h)) {
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case -EINVAL:
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clear_bit(CACHE_PENDING, &h->flags);
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if (rv == -EAGAIN) {
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set_bit(CACHE_NEGATIVE, &h->flags);
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cache_fresh_unlocked(h, detail,
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cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY));
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rv = -ENOENT;
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}
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break;
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case -EAGAIN:
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clear_bit(CACHE_PENDING, &h->flags);
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cache_revisit_request(h);
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break;
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}
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}
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}
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if (rv == -EAGAIN)
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if (cache_defer_req(rqstp, h) != 0)
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rv = -ETIMEDOUT;
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if (rv)
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cache_put(h, detail);
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return rv;
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}
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/*
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* caches need to be periodically cleaned.
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* For this we maintain a list of cache_detail and
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* a current pointer into that list and into the table
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* for that entry.
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*
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* Each time clean_cache is called it finds the next non-empty entry
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* in the current table and walks the list in that entry
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* looking for entries that can be removed.
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*
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* An entry gets removed if:
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* - The expiry is before current time
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* - The last_refresh time is before the flush_time for that cache
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*
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* later we might drop old entries with non-NEVER expiry if that table
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* is getting 'full' for some definition of 'full'
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*
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* The question of "how often to scan a table" is an interesting one
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* and is answered in part by the use of the "nextcheck" field in the
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* cache_detail.
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* When a scan of a table begins, the nextcheck field is set to a time
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* that is well into the future.
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* While scanning, if an expiry time is found that is earlier than the
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* current nextcheck time, nextcheck is set to that expiry time.
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* If the flush_time is ever set to a time earlier than the nextcheck
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* time, the nextcheck time is then set to that flush_time.
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*
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* A table is then only scanned if the current time is at least
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* the nextcheck time.
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*
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*/
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static LIST_HEAD(cache_list);
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static DEFINE_SPINLOCK(cache_list_lock);
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static struct cache_detail *current_detail;
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static int current_index;
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static const struct file_operations cache_file_operations;
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static const struct file_operations content_file_operations;
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static const struct file_operations cache_flush_operations;
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static void do_cache_clean(struct work_struct *work);
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static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean);
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static void remove_cache_proc_entries(struct cache_detail *cd)
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{
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if (cd->proc_ent == NULL)
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return;
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if (cd->flush_ent)
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remove_proc_entry("flush", cd->proc_ent);
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if (cd->channel_ent)
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remove_proc_entry("channel", cd->proc_ent);
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if (cd->content_ent)
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remove_proc_entry("content", cd->proc_ent);
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cd->proc_ent = NULL;
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remove_proc_entry(cd->name, proc_net_rpc);
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}
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static void create_cache_proc_entries(struct cache_detail *cd)
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{
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struct proc_dir_entry *p;
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cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
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if (cd->proc_ent == NULL)
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return;
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cd->proc_ent->owner = cd->owner;
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cd->channel_ent = cd->content_ent = NULL;
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p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR, cd->proc_ent);
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cd->flush_ent = p;
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if (p == NULL)
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return;
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p->proc_fops = &cache_flush_operations;
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p->owner = cd->owner;
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p->data = cd;
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if (cd->cache_request || cd->cache_parse) {
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p = create_proc_entry("channel", S_IFREG|S_IRUSR|S_IWUSR,
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cd->proc_ent);
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cd->channel_ent = p;
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if (p == NULL)
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return;
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p->proc_fops = &cache_file_operations;
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p->owner = cd->owner;
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p->data = cd;
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}
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if (cd->cache_show) {
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p = create_proc_entry("content", S_IFREG|S_IRUSR|S_IWUSR,
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cd->proc_ent);
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cd->content_ent = p;
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if (p == NULL)
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return;
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p->proc_fops = &content_file_operations;
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p->owner = cd->owner;
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p->data = cd;
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}
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}
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void cache_register(struct cache_detail *cd)
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{
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create_cache_proc_entries(cd);
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rwlock_init(&cd->hash_lock);
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INIT_LIST_HEAD(&cd->queue);
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spin_lock(&cache_list_lock);
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cd->nextcheck = 0;
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cd->entries = 0;
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atomic_set(&cd->readers, 0);
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cd->last_close = 0;
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cd->last_warn = -1;
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list_add(&cd->others, &cache_list);
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spin_unlock(&cache_list_lock);
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/* start the cleaning process */
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schedule_delayed_work(&cache_cleaner, 0);
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}
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void cache_unregister(struct cache_detail *cd)
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{
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cache_purge(cd);
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spin_lock(&cache_list_lock);
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write_lock(&cd->hash_lock);
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if (cd->entries || atomic_read(&cd->inuse)) {
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write_unlock(&cd->hash_lock);
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spin_unlock(&cache_list_lock);
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goto out;
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}
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if (current_detail == cd)
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current_detail = NULL;
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list_del_init(&cd->others);
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write_unlock(&cd->hash_lock);
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spin_unlock(&cache_list_lock);
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remove_cache_proc_entries(cd);
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if (list_empty(&cache_list)) {
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/* module must be being unloaded so its safe to kill the worker */
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cancel_delayed_work_sync(&cache_cleaner);
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}
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return;
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out:
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printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
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}
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/* clean cache tries to find something to clean
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* and cleans it.
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* It returns 1 if it cleaned something,
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* 0 if it didn't find anything this time
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* -1 if it fell off the end of the list.
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*/
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static int cache_clean(void)
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{
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int rv = 0;
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struct list_head *next;
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spin_lock(&cache_list_lock);
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/* find a suitable table if we don't already have one */
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while (current_detail == NULL ||
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current_index >= current_detail->hash_size) {
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if (current_detail)
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next = current_detail->others.next;
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else
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next = cache_list.next;
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if (next == &cache_list) {
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current_detail = NULL;
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spin_unlock(&cache_list_lock);
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return -1;
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}
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current_detail = list_entry(next, struct cache_detail, others);
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if (current_detail->nextcheck > get_seconds())
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current_index = current_detail->hash_size;
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else {
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current_index = 0;
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current_detail->nextcheck = get_seconds()+30*60;
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}
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}
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/* find a non-empty bucket in the table */
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while (current_detail &&
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current_index < current_detail->hash_size &&
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current_detail->hash_table[current_index] == NULL)
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current_index++;
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/* find a cleanable entry in the bucket and clean it, or set to next bucket */
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if (current_detail && current_index < current_detail->hash_size) {
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struct cache_head *ch, **cp;
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struct cache_detail *d;
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write_lock(¤t_detail->hash_lock);
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/* Ok, now to clean this strand */
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cp = & current_detail->hash_table[current_index];
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ch = *cp;
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for (; ch; cp= & ch->next, ch= *cp) {
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if (current_detail->nextcheck > ch->expiry_time)
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current_detail->nextcheck = ch->expiry_time+1;
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if (ch->expiry_time >= get_seconds()
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&& ch->last_refresh >= current_detail->flush_time
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)
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continue;
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if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
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queue_loose(current_detail, ch);
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if (atomic_read(&ch->ref.refcount) == 1)
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break;
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}
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if (ch) {
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*cp = ch->next;
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ch->next = NULL;
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current_detail->entries--;
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rv = 1;
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}
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write_unlock(¤t_detail->hash_lock);
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d = current_detail;
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if (!ch)
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current_index ++;
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spin_unlock(&cache_list_lock);
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if (ch)
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cache_put(ch, d);
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} else
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spin_unlock(&cache_list_lock);
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return rv;
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}
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|
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/*
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* We want to regularly clean the cache, so we need to schedule some work ...
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*/
|
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static void do_cache_clean(struct work_struct *work)
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{
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int delay = 5;
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if (cache_clean() == -1)
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delay = 30*HZ;
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|
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if (list_empty(&cache_list))
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delay = 0;
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if (delay)
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schedule_delayed_work(&cache_cleaner, delay);
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}
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|
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|
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/*
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* Clean all caches promptly. This just calls cache_clean
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* repeatedly until we are sure that every cache has had a chance to
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* be fully cleaned
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*/
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void cache_flush(void)
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{
|
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while (cache_clean() != -1)
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cond_resched();
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while (cache_clean() != -1)
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cond_resched();
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}
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|
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void cache_purge(struct cache_detail *detail)
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{
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detail->flush_time = LONG_MAX;
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detail->nextcheck = get_seconds();
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cache_flush();
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detail->flush_time = 1;
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}
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|
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|
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/*
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* Deferral and Revisiting of Requests.
|
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*
|
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* If a cache lookup finds a pending entry, we
|
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* need to defer the request and revisit it later.
|
|
* All deferred requests are stored in a hash table,
|
|
* indexed by "struct cache_head *".
|
|
* As it may be wasteful to store a whole request
|
|
* structure, we allow the request to provide a
|
|
* deferred form, which must contain a
|
|
* 'struct cache_deferred_req'
|
|
* This cache_deferred_req contains a method to allow
|
|
* it to be revisited when cache info is available
|
|
*/
|
|
|
|
#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
|
|
#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
|
|
|
|
#define DFR_MAX 300 /* ??? */
|
|
|
|
static DEFINE_SPINLOCK(cache_defer_lock);
|
|
static LIST_HEAD(cache_defer_list);
|
|
static struct list_head cache_defer_hash[DFR_HASHSIZE];
|
|
static int cache_defer_cnt;
|
|
|
|
static int cache_defer_req(struct cache_req *req, struct cache_head *item)
|
|
{
|
|
struct cache_deferred_req *dreq;
|
|
int hash = DFR_HASH(item);
|
|
|
|
if (cache_defer_cnt >= DFR_MAX) {
|
|
/* too much in the cache, randomly drop this one,
|
|
* or continue and drop the oldest below
|
|
*/
|
|
if (net_random()&1)
|
|
return -ETIMEDOUT;
|
|
}
|
|
dreq = req->defer(req);
|
|
if (dreq == NULL)
|
|
return -ETIMEDOUT;
|
|
|
|
dreq->item = item;
|
|
dreq->recv_time = get_seconds();
|
|
|
|
spin_lock(&cache_defer_lock);
|
|
|
|
list_add(&dreq->recent, &cache_defer_list);
|
|
|
|
if (cache_defer_hash[hash].next == NULL)
|
|
INIT_LIST_HEAD(&cache_defer_hash[hash]);
|
|
list_add(&dreq->hash, &cache_defer_hash[hash]);
|
|
|
|
/* it is in, now maybe clean up */
|
|
dreq = NULL;
|
|
if (++cache_defer_cnt > DFR_MAX) {
|
|
dreq = list_entry(cache_defer_list.prev,
|
|
struct cache_deferred_req, recent);
|
|
list_del(&dreq->recent);
|
|
list_del(&dreq->hash);
|
|
cache_defer_cnt--;
|
|
}
|
|
spin_unlock(&cache_defer_lock);
|
|
|
|
if (dreq) {
|
|
/* there was one too many */
|
|
dreq->revisit(dreq, 1);
|
|
}
|
|
if (!test_bit(CACHE_PENDING, &item->flags)) {
|
|
/* must have just been validated... */
|
|
cache_revisit_request(item);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void cache_revisit_request(struct cache_head *item)
|
|
{
|
|
struct cache_deferred_req *dreq;
|
|
struct list_head pending;
|
|
|
|
struct list_head *lp;
|
|
int hash = DFR_HASH(item);
|
|
|
|
INIT_LIST_HEAD(&pending);
|
|
spin_lock(&cache_defer_lock);
|
|
|
|
lp = cache_defer_hash[hash].next;
|
|
if (lp) {
|
|
while (lp != &cache_defer_hash[hash]) {
|
|
dreq = list_entry(lp, struct cache_deferred_req, hash);
|
|
lp = lp->next;
|
|
if (dreq->item == item) {
|
|
list_del(&dreq->hash);
|
|
list_move(&dreq->recent, &pending);
|
|
cache_defer_cnt--;
|
|
}
|
|
}
|
|
}
|
|
spin_unlock(&cache_defer_lock);
|
|
|
|
while (!list_empty(&pending)) {
|
|
dreq = list_entry(pending.next, struct cache_deferred_req, recent);
|
|
list_del_init(&dreq->recent);
|
|
dreq->revisit(dreq, 0);
|
|
}
|
|
}
|
|
|
|
void cache_clean_deferred(void *owner)
|
|
{
|
|
struct cache_deferred_req *dreq, *tmp;
|
|
struct list_head pending;
|
|
|
|
|
|
INIT_LIST_HEAD(&pending);
|
|
spin_lock(&cache_defer_lock);
|
|
|
|
list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
|
|
if (dreq->owner == owner) {
|
|
list_del(&dreq->hash);
|
|
list_move(&dreq->recent, &pending);
|
|
cache_defer_cnt--;
|
|
}
|
|
}
|
|
spin_unlock(&cache_defer_lock);
|
|
|
|
while (!list_empty(&pending)) {
|
|
dreq = list_entry(pending.next, struct cache_deferred_req, recent);
|
|
list_del_init(&dreq->recent);
|
|
dreq->revisit(dreq, 1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* communicate with user-space
|
|
*
|
|
* We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
|
|
* On read, you get a full request, or block.
|
|
* On write, an update request is processed.
|
|
* Poll works if anything to read, and always allows write.
|
|
*
|
|
* Implemented by linked list of requests. Each open file has
|
|
* a ->private that also exists in this list. New requests are added
|
|
* to the end and may wakeup and preceding readers.
|
|
* New readers are added to the head. If, on read, an item is found with
|
|
* CACHE_UPCALLING clear, we free it from the list.
|
|
*
|
|
*/
|
|
|
|
static DEFINE_SPINLOCK(queue_lock);
|
|
static DEFINE_MUTEX(queue_io_mutex);
|
|
|
|
struct cache_queue {
|
|
struct list_head list;
|
|
int reader; /* if 0, then request */
|
|
};
|
|
struct cache_request {
|
|
struct cache_queue q;
|
|
struct cache_head *item;
|
|
char * buf;
|
|
int len;
|
|
int readers;
|
|
};
|
|
struct cache_reader {
|
|
struct cache_queue q;
|
|
int offset; /* if non-0, we have a refcnt on next request */
|
|
};
|
|
|
|
static ssize_t
|
|
cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_request *rq;
|
|
struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
|
|
int err;
|
|
|
|
if (count == 0)
|
|
return 0;
|
|
|
|
mutex_lock(&queue_io_mutex); /* protect against multiple concurrent
|
|
* readers on this file */
|
|
again:
|
|
spin_lock(&queue_lock);
|
|
/* need to find next request */
|
|
while (rp->q.list.next != &cd->queue &&
|
|
list_entry(rp->q.list.next, struct cache_queue, list)
|
|
->reader) {
|
|
struct list_head *next = rp->q.list.next;
|
|
list_move(&rp->q.list, next);
|
|
}
|
|
if (rp->q.list.next == &cd->queue) {
|
|
spin_unlock(&queue_lock);
|
|
mutex_unlock(&queue_io_mutex);
|
|
BUG_ON(rp->offset);
|
|
return 0;
|
|
}
|
|
rq = container_of(rp->q.list.next, struct cache_request, q.list);
|
|
BUG_ON(rq->q.reader);
|
|
if (rp->offset == 0)
|
|
rq->readers++;
|
|
spin_unlock(&queue_lock);
|
|
|
|
if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
|
|
err = -EAGAIN;
|
|
spin_lock(&queue_lock);
|
|
list_move(&rp->q.list, &rq->q.list);
|
|
spin_unlock(&queue_lock);
|
|
} else {
|
|
if (rp->offset + count > rq->len)
|
|
count = rq->len - rp->offset;
|
|
err = -EFAULT;
|
|
if (copy_to_user(buf, rq->buf + rp->offset, count))
|
|
goto out;
|
|
rp->offset += count;
|
|
if (rp->offset >= rq->len) {
|
|
rp->offset = 0;
|
|
spin_lock(&queue_lock);
|
|
list_move(&rp->q.list, &rq->q.list);
|
|
spin_unlock(&queue_lock);
|
|
}
|
|
err = 0;
|
|
}
|
|
out:
|
|
if (rp->offset == 0) {
|
|
/* need to release rq */
|
|
spin_lock(&queue_lock);
|
|
rq->readers--;
|
|
if (rq->readers == 0 &&
|
|
!test_bit(CACHE_PENDING, &rq->item->flags)) {
|
|
list_del(&rq->q.list);
|
|
spin_unlock(&queue_lock);
|
|
cache_put(rq->item, cd);
|
|
kfree(rq->buf);
|
|
kfree(rq);
|
|
} else
|
|
spin_unlock(&queue_lock);
|
|
}
|
|
if (err == -EAGAIN)
|
|
goto again;
|
|
mutex_unlock(&queue_io_mutex);
|
|
return err ? err : count;
|
|
}
|
|
|
|
static char write_buf[8192]; /* protected by queue_io_mutex */
|
|
|
|
static ssize_t
|
|
cache_write(struct file *filp, const char __user *buf, size_t count,
|
|
loff_t *ppos)
|
|
{
|
|
int err;
|
|
struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
|
|
|
|
if (count == 0)
|
|
return 0;
|
|
if (count >= sizeof(write_buf))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&queue_io_mutex);
|
|
|
|
if (copy_from_user(write_buf, buf, count)) {
|
|
mutex_unlock(&queue_io_mutex);
|
|
return -EFAULT;
|
|
}
|
|
write_buf[count] = '\0';
|
|
if (cd->cache_parse)
|
|
err = cd->cache_parse(cd, write_buf, count);
|
|
else
|
|
err = -EINVAL;
|
|
|
|
mutex_unlock(&queue_io_mutex);
|
|
return err ? err : count;
|
|
}
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
|
|
|
|
static unsigned int
|
|
cache_poll(struct file *filp, poll_table *wait)
|
|
{
|
|
unsigned int mask;
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_queue *cq;
|
|
struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
|
|
|
|
poll_wait(filp, &queue_wait, wait);
|
|
|
|
/* alway allow write */
|
|
mask = POLL_OUT | POLLWRNORM;
|
|
|
|
if (!rp)
|
|
return mask;
|
|
|
|
spin_lock(&queue_lock);
|
|
|
|
for (cq= &rp->q; &cq->list != &cd->queue;
|
|
cq = list_entry(cq->list.next, struct cache_queue, list))
|
|
if (!cq->reader) {
|
|
mask |= POLLIN | POLLRDNORM;
|
|
break;
|
|
}
|
|
spin_unlock(&queue_lock);
|
|
return mask;
|
|
}
|
|
|
|
static int
|
|
cache_ioctl(struct inode *ino, struct file *filp,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
int len = 0;
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_queue *cq;
|
|
struct cache_detail *cd = PDE(ino)->data;
|
|
|
|
if (cmd != FIONREAD || !rp)
|
|
return -EINVAL;
|
|
|
|
spin_lock(&queue_lock);
|
|
|
|
/* only find the length remaining in current request,
|
|
* or the length of the next request
|
|
*/
|
|
for (cq= &rp->q; &cq->list != &cd->queue;
|
|
cq = list_entry(cq->list.next, struct cache_queue, list))
|
|
if (!cq->reader) {
|
|
struct cache_request *cr =
|
|
container_of(cq, struct cache_request, q);
|
|
len = cr->len - rp->offset;
|
|
break;
|
|
}
|
|
spin_unlock(&queue_lock);
|
|
|
|
return put_user(len, (int __user *)arg);
|
|
}
|
|
|
|
static int
|
|
cache_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_reader *rp = NULL;
|
|
|
|
nonseekable_open(inode, filp);
|
|
if (filp->f_mode & FMODE_READ) {
|
|
struct cache_detail *cd = PDE(inode)->data;
|
|
|
|
rp = kmalloc(sizeof(*rp), GFP_KERNEL);
|
|
if (!rp)
|
|
return -ENOMEM;
|
|
rp->offset = 0;
|
|
rp->q.reader = 1;
|
|
atomic_inc(&cd->readers);
|
|
spin_lock(&queue_lock);
|
|
list_add(&rp->q.list, &cd->queue);
|
|
spin_unlock(&queue_lock);
|
|
}
|
|
filp->private_data = rp;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
cache_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_detail *cd = PDE(inode)->data;
|
|
|
|
if (rp) {
|
|
spin_lock(&queue_lock);
|
|
if (rp->offset) {
|
|
struct cache_queue *cq;
|
|
for (cq= &rp->q; &cq->list != &cd->queue;
|
|
cq = list_entry(cq->list.next, struct cache_queue, list))
|
|
if (!cq->reader) {
|
|
container_of(cq, struct cache_request, q)
|
|
->readers--;
|
|
break;
|
|
}
|
|
rp->offset = 0;
|
|
}
|
|
list_del(&rp->q.list);
|
|
spin_unlock(&queue_lock);
|
|
|
|
filp->private_data = NULL;
|
|
kfree(rp);
|
|
|
|
cd->last_close = get_seconds();
|
|
atomic_dec(&cd->readers);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
static const struct file_operations cache_file_operations = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.read = cache_read,
|
|
.write = cache_write,
|
|
.poll = cache_poll,
|
|
.ioctl = cache_ioctl, /* for FIONREAD */
|
|
.open = cache_open,
|
|
.release = cache_release,
|
|
};
|
|
|
|
|
|
static void queue_loose(struct cache_detail *detail, struct cache_head *ch)
|
|
{
|
|
struct cache_queue *cq;
|
|
spin_lock(&queue_lock);
|
|
list_for_each_entry(cq, &detail->queue, list)
|
|
if (!cq->reader) {
|
|
struct cache_request *cr = container_of(cq, struct cache_request, q);
|
|
if (cr->item != ch)
|
|
continue;
|
|
if (cr->readers != 0)
|
|
continue;
|
|
list_del(&cr->q.list);
|
|
spin_unlock(&queue_lock);
|
|
cache_put(cr->item, detail);
|
|
kfree(cr->buf);
|
|
kfree(cr);
|
|
return;
|
|
}
|
|
spin_unlock(&queue_lock);
|
|
}
|
|
|
|
/*
|
|
* Support routines for text-based upcalls.
|
|
* Fields are separated by spaces.
|
|
* Fields are either mangled to quote space tab newline slosh with slosh
|
|
* or a hexified with a leading \x
|
|
* Record is terminated with newline.
|
|
*
|
|
*/
|
|
|
|
void qword_add(char **bpp, int *lp, char *str)
|
|
{
|
|
char *bp = *bpp;
|
|
int len = *lp;
|
|
char c;
|
|
|
|
if (len < 0) return;
|
|
|
|
while ((c=*str++) && len)
|
|
switch(c) {
|
|
case ' ':
|
|
case '\t':
|
|
case '\n':
|
|
case '\\':
|
|
if (len >= 4) {
|
|
*bp++ = '\\';
|
|
*bp++ = '0' + ((c & 0300)>>6);
|
|
*bp++ = '0' + ((c & 0070)>>3);
|
|
*bp++ = '0' + ((c & 0007)>>0);
|
|
}
|
|
len -= 4;
|
|
break;
|
|
default:
|
|
*bp++ = c;
|
|
len--;
|
|
}
|
|
if (c || len <1) len = -1;
|
|
else {
|
|
*bp++ = ' ';
|
|
len--;
|
|
}
|
|
*bpp = bp;
|
|
*lp = len;
|
|
}
|
|
|
|
void qword_addhex(char **bpp, int *lp, char *buf, int blen)
|
|
{
|
|
char *bp = *bpp;
|
|
int len = *lp;
|
|
|
|
if (len < 0) return;
|
|
|
|
if (len > 2) {
|
|
*bp++ = '\\';
|
|
*bp++ = 'x';
|
|
len -= 2;
|
|
while (blen && len >= 2) {
|
|
unsigned char c = *buf++;
|
|
*bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
|
|
*bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
|
|
len -= 2;
|
|
blen--;
|
|
}
|
|
}
|
|
if (blen || len<1) len = -1;
|
|
else {
|
|
*bp++ = ' ';
|
|
len--;
|
|
}
|
|
*bpp = bp;
|
|
*lp = len;
|
|
}
|
|
|
|
static void warn_no_listener(struct cache_detail *detail)
|
|
{
|
|
if (detail->last_warn != detail->last_close) {
|
|
detail->last_warn = detail->last_close;
|
|
if (detail->warn_no_listener)
|
|
detail->warn_no_listener(detail);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* register an upcall request to user-space.
|
|
* Each request is at most one page long.
|
|
*/
|
|
static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h)
|
|
{
|
|
|
|
char *buf;
|
|
struct cache_request *crq;
|
|
char *bp;
|
|
int len;
|
|
|
|
if (detail->cache_request == NULL)
|
|
return -EINVAL;
|
|
|
|
if (atomic_read(&detail->readers) == 0 &&
|
|
detail->last_close < get_seconds() - 30) {
|
|
warn_no_listener(detail);
|
|
return -EINVAL;
|
|
}
|
|
|
|
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!buf)
|
|
return -EAGAIN;
|
|
|
|
crq = kmalloc(sizeof (*crq), GFP_KERNEL);
|
|
if (!crq) {
|
|
kfree(buf);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
bp = buf; len = PAGE_SIZE;
|
|
|
|
detail->cache_request(detail, h, &bp, &len);
|
|
|
|
if (len < 0) {
|
|
kfree(buf);
|
|
kfree(crq);
|
|
return -EAGAIN;
|
|
}
|
|
crq->q.reader = 0;
|
|
crq->item = cache_get(h);
|
|
crq->buf = buf;
|
|
crq->len = PAGE_SIZE - len;
|
|
crq->readers = 0;
|
|
spin_lock(&queue_lock);
|
|
list_add_tail(&crq->q.list, &detail->queue);
|
|
spin_unlock(&queue_lock);
|
|
wake_up(&queue_wait);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* parse a message from user-space and pass it
|
|
* to an appropriate cache
|
|
* Messages are, like requests, separated into fields by
|
|
* spaces and dequotes as \xHEXSTRING or embedded \nnn octal
|
|
*
|
|
* Message is
|
|
* reply cachename expiry key ... content....
|
|
*
|
|
* key and content are both parsed by cache
|
|
*/
|
|
|
|
#define isodigit(c) (isdigit(c) && c <= '7')
|
|
int qword_get(char **bpp, char *dest, int bufsize)
|
|
{
|
|
/* return bytes copied, or -1 on error */
|
|
char *bp = *bpp;
|
|
int len = 0;
|
|
|
|
while (*bp == ' ') bp++;
|
|
|
|
if (bp[0] == '\\' && bp[1] == 'x') {
|
|
/* HEX STRING */
|
|
bp += 2;
|
|
while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) {
|
|
int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
|
|
bp++;
|
|
byte <<= 4;
|
|
byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
|
|
*dest++ = byte;
|
|
bp++;
|
|
len++;
|
|
}
|
|
} else {
|
|
/* text with \nnn octal quoting */
|
|
while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
|
|
if (*bp == '\\' &&
|
|
isodigit(bp[1]) && (bp[1] <= '3') &&
|
|
isodigit(bp[2]) &&
|
|
isodigit(bp[3])) {
|
|
int byte = (*++bp -'0');
|
|
bp++;
|
|
byte = (byte << 3) | (*bp++ - '0');
|
|
byte = (byte << 3) | (*bp++ - '0');
|
|
*dest++ = byte;
|
|
len++;
|
|
} else {
|
|
*dest++ = *bp++;
|
|
len++;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (*bp != ' ' && *bp != '\n' && *bp != '\0')
|
|
return -1;
|
|
while (*bp == ' ') bp++;
|
|
*bpp = bp;
|
|
*dest = '\0';
|
|
return len;
|
|
}
|
|
|
|
|
|
/*
|
|
* support /proc/sunrpc/cache/$CACHENAME/content
|
|
* as a seqfile.
|
|
* We call ->cache_show passing NULL for the item to
|
|
* get a header, then pass each real item in the cache
|
|
*/
|
|
|
|
struct handle {
|
|
struct cache_detail *cd;
|
|
};
|
|
|
|
static void *c_start(struct seq_file *m, loff_t *pos)
|
|
__acquires(cd->hash_lock)
|
|
{
|
|
loff_t n = *pos;
|
|
unsigned hash, entry;
|
|
struct cache_head *ch;
|
|
struct cache_detail *cd = ((struct handle*)m->private)->cd;
|
|
|
|
|
|
read_lock(&cd->hash_lock);
|
|
if (!n--)
|
|
return SEQ_START_TOKEN;
|
|
hash = n >> 32;
|
|
entry = n & ((1LL<<32) - 1);
|
|
|
|
for (ch=cd->hash_table[hash]; ch; ch=ch->next)
|
|
if (!entry--)
|
|
return ch;
|
|
n &= ~((1LL<<32) - 1);
|
|
do {
|
|
hash++;
|
|
n += 1LL<<32;
|
|
} while(hash < cd->hash_size &&
|
|
cd->hash_table[hash]==NULL);
|
|
if (hash >= cd->hash_size)
|
|
return NULL;
|
|
*pos = n+1;
|
|
return cd->hash_table[hash];
|
|
}
|
|
|
|
static void *c_next(struct seq_file *m, void *p, loff_t *pos)
|
|
{
|
|
struct cache_head *ch = p;
|
|
int hash = (*pos >> 32);
|
|
struct cache_detail *cd = ((struct handle*)m->private)->cd;
|
|
|
|
if (p == SEQ_START_TOKEN)
|
|
hash = 0;
|
|
else if (ch->next == NULL) {
|
|
hash++;
|
|
*pos += 1LL<<32;
|
|
} else {
|
|
++*pos;
|
|
return ch->next;
|
|
}
|
|
*pos &= ~((1LL<<32) - 1);
|
|
while (hash < cd->hash_size &&
|
|
cd->hash_table[hash] == NULL) {
|
|
hash++;
|
|
*pos += 1LL<<32;
|
|
}
|
|
if (hash >= cd->hash_size)
|
|
return NULL;
|
|
++*pos;
|
|
return cd->hash_table[hash];
|
|
}
|
|
|
|
static void c_stop(struct seq_file *m, void *p)
|
|
__releases(cd->hash_lock)
|
|
{
|
|
struct cache_detail *cd = ((struct handle*)m->private)->cd;
|
|
read_unlock(&cd->hash_lock);
|
|
}
|
|
|
|
static int c_show(struct seq_file *m, void *p)
|
|
{
|
|
struct cache_head *cp = p;
|
|
struct cache_detail *cd = ((struct handle*)m->private)->cd;
|
|
|
|
if (p == SEQ_START_TOKEN)
|
|
return cd->cache_show(m, cd, NULL);
|
|
|
|
ifdebug(CACHE)
|
|
seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
|
|
cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags);
|
|
cache_get(cp);
|
|
if (cache_check(cd, cp, NULL))
|
|
/* cache_check does a cache_put on failure */
|
|
seq_printf(m, "# ");
|
|
else
|
|
cache_put(cp, cd);
|
|
|
|
return cd->cache_show(m, cd, cp);
|
|
}
|
|
|
|
static const struct seq_operations cache_content_op = {
|
|
.start = c_start,
|
|
.next = c_next,
|
|
.stop = c_stop,
|
|
.show = c_show,
|
|
};
|
|
|
|
static int content_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct handle *han;
|
|
struct cache_detail *cd = PDE(inode)->data;
|
|
|
|
han = __seq_open_private(file, &cache_content_op, sizeof(*han));
|
|
if (han == NULL)
|
|
return -ENOMEM;
|
|
|
|
han->cd = cd;
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations content_file_operations = {
|
|
.open = content_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
};
|
|
|
|
static ssize_t read_flush(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
|
|
char tbuf[20];
|
|
unsigned long p = *ppos;
|
|
size_t len;
|
|
|
|
sprintf(tbuf, "%lu\n", cd->flush_time);
|
|
len = strlen(tbuf);
|
|
if (p >= len)
|
|
return 0;
|
|
len -= p;
|
|
if (len > count)
|
|
len = count;
|
|
if (copy_to_user(buf, (void*)(tbuf+p), len))
|
|
return -EFAULT;
|
|
*ppos += len;
|
|
return len;
|
|
}
|
|
|
|
static ssize_t write_flush(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
|
|
char tbuf[20];
|
|
char *ep;
|
|
long flushtime;
|
|
if (*ppos || count > sizeof(tbuf)-1)
|
|
return -EINVAL;
|
|
if (copy_from_user(tbuf, buf, count))
|
|
return -EFAULT;
|
|
tbuf[count] = 0;
|
|
flushtime = simple_strtoul(tbuf, &ep, 0);
|
|
if (*ep && *ep != '\n')
|
|
return -EINVAL;
|
|
|
|
cd->flush_time = flushtime;
|
|
cd->nextcheck = get_seconds();
|
|
cache_flush();
|
|
|
|
*ppos += count;
|
|
return count;
|
|
}
|
|
|
|
static const struct file_operations cache_flush_operations = {
|
|
.open = nonseekable_open,
|
|
.read = read_flush,
|
|
.write = write_flush,
|
|
};
|