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![Yihao Wu](/assets/img/avatar_default.png)
Deleting list entry within hlist_for_each_entry_safe is not safe unless next pointer (tmp) is protected too. It's not, because once hash_lock is released, cache_clean may delete the entry that tmp points to. Then cache_purge can walk to a deleted entry and tries to double free it. Fix this bug by holding only the deleted entry's reference. Suggested-by: NeilBrown <neilb@suse.de> Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com> Reviewed-by: NeilBrown <neilb@suse.de> [ cel: removed unused variable ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
1920 lines
46 KiB
C
1920 lines
46 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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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#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 <linux/string_helpers.h>
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#include <linux/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 <linux/pagemap.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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#include <linux/sunrpc/rpc_pipe_fs.h>
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#include <trace/events/sunrpc.h>
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#include "netns.h"
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#define RPCDBG_FACILITY RPCDBG_CACHE
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static bool 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, struct cache_detail *detail)
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{
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time64_t now = seconds_since_boot();
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INIT_HLIST_NODE(&h->cache_list);
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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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if (now <= detail->flush_time)
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/* ensure it isn't already expired */
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now = detail->flush_time + 1;
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h->last_refresh = now;
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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);
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static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail,
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struct cache_head *key,
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int hash)
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{
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struct hlist_head *head = &detail->hash_table[hash];
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struct cache_head *tmp;
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rcu_read_lock();
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hlist_for_each_entry_rcu(tmp, head, cache_list) {
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if (!detail->match(tmp, key))
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continue;
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if (test_bit(CACHE_VALID, &tmp->flags) &&
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cache_is_expired(detail, tmp))
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continue;
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tmp = cache_get_rcu(tmp);
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rcu_read_unlock();
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return tmp;
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}
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rcu_read_unlock();
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return NULL;
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}
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static void sunrpc_begin_cache_remove_entry(struct cache_head *ch,
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struct cache_detail *cd)
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{
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/* Must be called under cd->hash_lock */
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hlist_del_init_rcu(&ch->cache_list);
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set_bit(CACHE_CLEANED, &ch->flags);
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cd->entries --;
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}
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static void sunrpc_end_cache_remove_entry(struct cache_head *ch,
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struct cache_detail *cd)
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{
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cache_fresh_unlocked(ch, cd);
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cache_put(ch, cd);
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}
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static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
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struct cache_head *key,
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int hash)
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{
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struct cache_head *new, *tmp, *freeme = NULL;
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struct hlist_head *head = &detail->hash_table[hash];
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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, detail);
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detail->init(new, key);
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spin_lock(&detail->hash_lock);
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/* check if entry appeared while we slept */
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hlist_for_each_entry_rcu(tmp, head, cache_list,
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lockdep_is_held(&detail->hash_lock)) {
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if (!detail->match(tmp, key))
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continue;
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if (test_bit(CACHE_VALID, &tmp->flags) &&
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cache_is_expired(detail, tmp)) {
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sunrpc_begin_cache_remove_entry(tmp, detail);
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trace_cache_entry_expired(detail, tmp);
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freeme = tmp;
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break;
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}
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cache_get(tmp);
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spin_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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hlist_add_head_rcu(&new->cache_list, head);
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detail->entries++;
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cache_get(new);
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spin_unlock(&detail->hash_lock);
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if (freeme)
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sunrpc_end_cache_remove_entry(freeme, detail);
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return new;
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}
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struct cache_head *sunrpc_cache_lookup_rcu(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 *ret;
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ret = sunrpc_cache_find_rcu(detail, key, hash);
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if (ret)
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return ret;
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/* Didn't find anything, insert an empty entry */
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return sunrpc_cache_add_entry(detail, key, hash);
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}
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EXPORT_SYMBOL_GPL(sunrpc_cache_lookup_rcu);
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static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
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static void cache_fresh_locked(struct cache_head *head, time64_t expiry,
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struct cache_detail *detail)
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{
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time64_t now = seconds_since_boot();
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if (now <= detail->flush_time)
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/* ensure it isn't immediately treated as expired */
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now = detail->flush_time + 1;
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head->expiry_time = expiry;
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head->last_refresh = now;
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smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
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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)
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{
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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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cache_dequeue(detail, head);
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}
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}
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static void cache_make_negative(struct cache_detail *detail,
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struct cache_head *h)
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{
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set_bit(CACHE_NEGATIVE, &h->flags);
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trace_cache_entry_make_negative(detail, h);
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}
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static void cache_entry_update(struct cache_detail *detail,
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struct cache_head *h,
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struct cache_head *new)
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{
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if (!test_bit(CACHE_NEGATIVE, &new->flags)) {
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detail->update(h, new);
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trace_cache_entry_update(detail, h);
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} else {
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cache_make_negative(detail, h);
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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 *tmp;
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if (!test_bit(CACHE_VALID, &old->flags)) {
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spin_lock(&detail->hash_lock);
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if (!test_bit(CACHE_VALID, &old->flags)) {
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cache_entry_update(detail, old, new);
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cache_fresh_locked(old, new->expiry_time, detail);
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spin_unlock(&detail->hash_lock);
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cache_fresh_unlocked(old, detail);
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return old;
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}
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spin_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, detail);
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detail->init(tmp, old);
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spin_lock(&detail->hash_lock);
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cache_entry_update(detail, tmp, new);
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hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
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detail->entries++;
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cache_get(tmp);
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cache_fresh_locked(tmp, new->expiry_time, detail);
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cache_fresh_locked(old, 0, detail);
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spin_unlock(&detail->hash_lock);
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cache_fresh_unlocked(tmp, detail);
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cache_fresh_unlocked(old, detail);
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cache_put(old, detail);
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return tmp;
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}
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EXPORT_SYMBOL_GPL(sunrpc_cache_update);
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static inline int cache_is_valid(struct cache_head *h)
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{
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if (!test_bit(CACHE_VALID, &h->flags))
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return -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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return -ENOENT;
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else {
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/*
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* In combination with write barrier in
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* sunrpc_cache_update, ensures that anyone
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* using the cache entry after this sees the
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* updated contents:
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*/
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smp_rmb();
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return 0;
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}
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}
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}
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static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
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{
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int rv;
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spin_lock(&detail->hash_lock);
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rv = cache_is_valid(h);
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if (rv == -EAGAIN) {
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cache_make_negative(detail, h);
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cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
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detail);
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rv = -ENOENT;
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}
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spin_unlock(&detail->hash_lock);
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cache_fresh_unlocked(h, detail);
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return rv;
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}
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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 and request has been queued
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* -ETIMEDOUT if upcall failed or request could not be queue or
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* upcall completed but item is still invalid (implying that
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* the cache item has been replaced with a newer one).
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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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time64_t refresh_age, age;
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/* First decide return status as best we can */
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rv = cache_is_valid(h);
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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 = seconds_since_boot() - 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 ||
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(h->expiry_time != 0 && age > refresh_age/2)) {
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dprintk("RPC: Want update, refage=%lld, age=%lld\n",
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refresh_age, age);
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switch (detail->cache_upcall(detail, h)) {
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case -EINVAL:
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rv = try_to_negate_entry(detail, h);
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break;
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case -EAGAIN:
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cache_fresh_unlocked(h, detail);
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break;
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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)) {
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/*
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* Request was not deferred; handle it as best
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* we can ourselves:
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*/
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rv = cache_is_valid(h);
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if (rv == -EAGAIN)
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rv = -ETIMEDOUT;
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}
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}
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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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EXPORT_SYMBOL_GPL(cache_check);
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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 cache_clean 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 void do_cache_clean(struct work_struct *work);
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static struct delayed_work cache_cleaner;
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void sunrpc_init_cache_detail(struct cache_detail *cd)
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{
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spin_lock_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->writers, 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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queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0);
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}
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EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
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void sunrpc_destroy_cache_detail(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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spin_lock(&cd->hash_lock);
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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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spin_unlock(&cd->hash_lock);
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spin_unlock(&cache_list_lock);
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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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}
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EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
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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 > seconds_since_boot())
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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 = seconds_since_boot()+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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hlist_empty(¤t_detail->hash_table[current_index]))
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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 = NULL;
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struct cache_detail *d;
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struct hlist_head *head;
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struct hlist_node *tmp;
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spin_lock(¤t_detail->hash_lock);
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/* Ok, now to clean this strand */
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head = ¤t_detail->hash_table[current_index];
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hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
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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 (!cache_is_expired(current_detail, ch))
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continue;
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sunrpc_begin_cache_remove_entry(ch, current_detail);
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trace_cache_entry_expired(current_detail, ch);
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rv = 1;
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break;
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}
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spin_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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sunrpc_end_cache_remove_entry(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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* 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)
|
|
delay = round_jiffies_relative(30*HZ);
|
|
|
|
if (list_empty(&cache_list))
|
|
delay = 0;
|
|
|
|
if (delay)
|
|
queue_delayed_work(system_power_efficient_wq,
|
|
&cache_cleaner, delay);
|
|
}
|
|
|
|
|
|
/*
|
|
* Clean all caches promptly. This just calls cache_clean
|
|
* repeatedly until we are sure that every cache has had a chance to
|
|
* be fully cleaned
|
|
*/
|
|
void cache_flush(void)
|
|
{
|
|
while (cache_clean() != -1)
|
|
cond_resched();
|
|
while (cache_clean() != -1)
|
|
cond_resched();
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_flush);
|
|
|
|
void cache_purge(struct cache_detail *detail)
|
|
{
|
|
struct cache_head *ch = NULL;
|
|
struct hlist_head *head = NULL;
|
|
int i = 0;
|
|
|
|
spin_lock(&detail->hash_lock);
|
|
if (!detail->entries) {
|
|
spin_unlock(&detail->hash_lock);
|
|
return;
|
|
}
|
|
|
|
dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name);
|
|
for (i = 0; i < detail->hash_size; i++) {
|
|
head = &detail->hash_table[i];
|
|
while (!hlist_empty(head)) {
|
|
ch = hlist_entry(head->first, struct cache_head,
|
|
cache_list);
|
|
sunrpc_begin_cache_remove_entry(ch, detail);
|
|
spin_unlock(&detail->hash_lock);
|
|
sunrpc_end_cache_remove_entry(ch, detail);
|
|
spin_lock(&detail->hash_lock);
|
|
}
|
|
}
|
|
spin_unlock(&detail->hash_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_purge);
|
|
|
|
|
|
/*
|
|
* Deferral and Revisiting of Requests.
|
|
*
|
|
* If a cache lookup finds a pending entry, we
|
|
* 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 hlist_head cache_defer_hash[DFR_HASHSIZE];
|
|
static int cache_defer_cnt;
|
|
|
|
static void __unhash_deferred_req(struct cache_deferred_req *dreq)
|
|
{
|
|
hlist_del_init(&dreq->hash);
|
|
if (!list_empty(&dreq->recent)) {
|
|
list_del_init(&dreq->recent);
|
|
cache_defer_cnt--;
|
|
}
|
|
}
|
|
|
|
static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
|
|
{
|
|
int hash = DFR_HASH(item);
|
|
|
|
INIT_LIST_HEAD(&dreq->recent);
|
|
hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
|
|
}
|
|
|
|
static void setup_deferral(struct cache_deferred_req *dreq,
|
|
struct cache_head *item,
|
|
int count_me)
|
|
{
|
|
|
|
dreq->item = item;
|
|
|
|
spin_lock(&cache_defer_lock);
|
|
|
|
__hash_deferred_req(dreq, item);
|
|
|
|
if (count_me) {
|
|
cache_defer_cnt++;
|
|
list_add(&dreq->recent, &cache_defer_list);
|
|
}
|
|
|
|
spin_unlock(&cache_defer_lock);
|
|
|
|
}
|
|
|
|
struct thread_deferred_req {
|
|
struct cache_deferred_req handle;
|
|
struct completion completion;
|
|
};
|
|
|
|
static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
|
|
{
|
|
struct thread_deferred_req *dr =
|
|
container_of(dreq, struct thread_deferred_req, handle);
|
|
complete(&dr->completion);
|
|
}
|
|
|
|
static void cache_wait_req(struct cache_req *req, struct cache_head *item)
|
|
{
|
|
struct thread_deferred_req sleeper;
|
|
struct cache_deferred_req *dreq = &sleeper.handle;
|
|
|
|
sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
|
|
dreq->revisit = cache_restart_thread;
|
|
|
|
setup_deferral(dreq, item, 0);
|
|
|
|
if (!test_bit(CACHE_PENDING, &item->flags) ||
|
|
wait_for_completion_interruptible_timeout(
|
|
&sleeper.completion, req->thread_wait) <= 0) {
|
|
/* The completion wasn't completed, so we need
|
|
* to clean up
|
|
*/
|
|
spin_lock(&cache_defer_lock);
|
|
if (!hlist_unhashed(&sleeper.handle.hash)) {
|
|
__unhash_deferred_req(&sleeper.handle);
|
|
spin_unlock(&cache_defer_lock);
|
|
} else {
|
|
/* cache_revisit_request already removed
|
|
* this from the hash table, but hasn't
|
|
* called ->revisit yet. It will very soon
|
|
* and we need to wait for it.
|
|
*/
|
|
spin_unlock(&cache_defer_lock);
|
|
wait_for_completion(&sleeper.completion);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void cache_limit_defers(void)
|
|
{
|
|
/* Make sure we haven't exceed the limit of allowed deferred
|
|
* requests.
|
|
*/
|
|
struct cache_deferred_req *discard = NULL;
|
|
|
|
if (cache_defer_cnt <= DFR_MAX)
|
|
return;
|
|
|
|
spin_lock(&cache_defer_lock);
|
|
|
|
/* Consider removing either the first or the last */
|
|
if (cache_defer_cnt > DFR_MAX) {
|
|
if (prandom_u32() & 1)
|
|
discard = list_entry(cache_defer_list.next,
|
|
struct cache_deferred_req, recent);
|
|
else
|
|
discard = list_entry(cache_defer_list.prev,
|
|
struct cache_deferred_req, recent);
|
|
__unhash_deferred_req(discard);
|
|
}
|
|
spin_unlock(&cache_defer_lock);
|
|
if (discard)
|
|
discard->revisit(discard, 1);
|
|
}
|
|
|
|
/* Return true if and only if a deferred request is queued. */
|
|
static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
|
|
{
|
|
struct cache_deferred_req *dreq;
|
|
|
|
if (req->thread_wait) {
|
|
cache_wait_req(req, item);
|
|
if (!test_bit(CACHE_PENDING, &item->flags))
|
|
return false;
|
|
}
|
|
dreq = req->defer(req);
|
|
if (dreq == NULL)
|
|
return false;
|
|
setup_deferral(dreq, item, 1);
|
|
if (!test_bit(CACHE_PENDING, &item->flags))
|
|
/* Bit could have been cleared before we managed to
|
|
* set up the deferral, so need to revisit just in case
|
|
*/
|
|
cache_revisit_request(item);
|
|
|
|
cache_limit_defers();
|
|
return true;
|
|
}
|
|
|
|
static void cache_revisit_request(struct cache_head *item)
|
|
{
|
|
struct cache_deferred_req *dreq;
|
|
struct list_head pending;
|
|
struct hlist_node *tmp;
|
|
int hash = DFR_HASH(item);
|
|
|
|
INIT_LIST_HEAD(&pending);
|
|
spin_lock(&cache_defer_lock);
|
|
|
|
hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash)
|
|
if (dreq->item == item) {
|
|
__unhash_deferred_req(dreq);
|
|
list_add(&dreq->recent, &pending);
|
|
}
|
|
|
|
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) {
|
|
__unhash_deferred_req(dreq);
|
|
list_add(&dreq->recent, &pending);
|
|
}
|
|
}
|
|
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/net/rpc/<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 int cache_request(struct cache_detail *detail,
|
|
struct cache_request *crq)
|
|
{
|
|
char *bp = crq->buf;
|
|
int len = PAGE_SIZE;
|
|
|
|
detail->cache_request(detail, crq->item, &bp, &len);
|
|
if (len < 0)
|
|
return -EAGAIN;
|
|
return PAGE_SIZE - len;
|
|
}
|
|
|
|
static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
|
|
loff_t *ppos, struct cache_detail *cd)
|
|
{
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_request *rq;
|
|
struct inode *inode = file_inode(filp);
|
|
int err;
|
|
|
|
if (count == 0)
|
|
return 0;
|
|
|
|
inode_lock(inode); /* 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);
|
|
inode_unlock(inode);
|
|
WARN_ON_ONCE(rp->offset);
|
|
return 0;
|
|
}
|
|
rq = container_of(rp->q.list.next, struct cache_request, q.list);
|
|
WARN_ON_ONCE(rq->q.reader);
|
|
if (rp->offset == 0)
|
|
rq->readers++;
|
|
spin_unlock(&queue_lock);
|
|
|
|
if (rq->len == 0) {
|
|
err = cache_request(cd, rq);
|
|
if (err < 0)
|
|
goto out;
|
|
rq->len = err;
|
|
}
|
|
|
|
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;
|
|
inode_unlock(inode);
|
|
return err ? err : count;
|
|
}
|
|
|
|
static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
|
|
size_t count, struct cache_detail *cd)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (count == 0)
|
|
return -EINVAL;
|
|
if (copy_from_user(kaddr, buf, count))
|
|
return -EFAULT;
|
|
kaddr[count] = '\0';
|
|
ret = cd->cache_parse(cd, kaddr, count);
|
|
if (!ret)
|
|
ret = count;
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t cache_slow_downcall(const char __user *buf,
|
|
size_t count, struct cache_detail *cd)
|
|
{
|
|
static char write_buf[8192]; /* protected by queue_io_mutex */
|
|
ssize_t ret = -EINVAL;
|
|
|
|
if (count >= sizeof(write_buf))
|
|
goto out;
|
|
mutex_lock(&queue_io_mutex);
|
|
ret = cache_do_downcall(write_buf, buf, count, cd);
|
|
mutex_unlock(&queue_io_mutex);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t cache_downcall(struct address_space *mapping,
|
|
const char __user *buf,
|
|
size_t count, struct cache_detail *cd)
|
|
{
|
|
struct page *page;
|
|
char *kaddr;
|
|
ssize_t ret = -ENOMEM;
|
|
|
|
if (count >= PAGE_SIZE)
|
|
goto out_slow;
|
|
|
|
page = find_or_create_page(mapping, 0, GFP_KERNEL);
|
|
if (!page)
|
|
goto out_slow;
|
|
|
|
kaddr = kmap(page);
|
|
ret = cache_do_downcall(kaddr, buf, count, cd);
|
|
kunmap(page);
|
|
unlock_page(page);
|
|
put_page(page);
|
|
return ret;
|
|
out_slow:
|
|
return cache_slow_downcall(buf, count, cd);
|
|
}
|
|
|
|
static ssize_t cache_write(struct file *filp, const char __user *buf,
|
|
size_t count, loff_t *ppos,
|
|
struct cache_detail *cd)
|
|
{
|
|
struct address_space *mapping = filp->f_mapping;
|
|
struct inode *inode = file_inode(filp);
|
|
ssize_t ret = -EINVAL;
|
|
|
|
if (!cd->cache_parse)
|
|
goto out;
|
|
|
|
inode_lock(inode);
|
|
ret = cache_downcall(mapping, buf, count, cd);
|
|
inode_unlock(inode);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
|
|
|
|
static __poll_t cache_poll(struct file *filp, poll_table *wait,
|
|
struct cache_detail *cd)
|
|
{
|
|
__poll_t mask;
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_queue *cq;
|
|
|
|
poll_wait(filp, &queue_wait, wait);
|
|
|
|
/* alway allow write */
|
|
mask = EPOLLOUT | EPOLLWRNORM;
|
|
|
|
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 |= EPOLLIN | EPOLLRDNORM;
|
|
break;
|
|
}
|
|
spin_unlock(&queue_lock);
|
|
return mask;
|
|
}
|
|
|
|
static int cache_ioctl(struct inode *ino, struct file *filp,
|
|
unsigned int cmd, unsigned long arg,
|
|
struct cache_detail *cd)
|
|
{
|
|
int len = 0;
|
|
struct cache_reader *rp = filp->private_data;
|
|
struct cache_queue *cq;
|
|
|
|
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_detail *cd)
|
|
{
|
|
struct cache_reader *rp = NULL;
|
|
|
|
if (!cd || !try_module_get(cd->owner))
|
|
return -EACCES;
|
|
nonseekable_open(inode, filp);
|
|
if (filp->f_mode & FMODE_READ) {
|
|
rp = kmalloc(sizeof(*rp), GFP_KERNEL);
|
|
if (!rp) {
|
|
module_put(cd->owner);
|
|
return -ENOMEM;
|
|
}
|
|
rp->offset = 0;
|
|
rp->q.reader = 1;
|
|
|
|
spin_lock(&queue_lock);
|
|
list_add(&rp->q.list, &cd->queue);
|
|
spin_unlock(&queue_lock);
|
|
}
|
|
if (filp->f_mode & FMODE_WRITE)
|
|
atomic_inc(&cd->writers);
|
|
filp->private_data = rp;
|
|
return 0;
|
|
}
|
|
|
|
static int cache_release(struct inode *inode, struct file *filp,
|
|
struct cache_detail *cd)
|
|
{
|
|
struct cache_reader *rp = filp->private_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);
|
|
|
|
}
|
|
if (filp->f_mode & FMODE_WRITE) {
|
|
atomic_dec(&cd->writers);
|
|
cd->last_close = seconds_since_boot();
|
|
}
|
|
module_put(cd->owner);
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
|
|
{
|
|
struct cache_queue *cq, *tmp;
|
|
struct cache_request *cr;
|
|
struct list_head dequeued;
|
|
|
|
INIT_LIST_HEAD(&dequeued);
|
|
spin_lock(&queue_lock);
|
|
list_for_each_entry_safe(cq, tmp, &detail->queue, list)
|
|
if (!cq->reader) {
|
|
cr = container_of(cq, struct cache_request, q);
|
|
if (cr->item != ch)
|
|
continue;
|
|
if (test_bit(CACHE_PENDING, &ch->flags))
|
|
/* Lost a race and it is pending again */
|
|
break;
|
|
if (cr->readers != 0)
|
|
continue;
|
|
list_move(&cr->q.list, &dequeued);
|
|
}
|
|
spin_unlock(&queue_lock);
|
|
while (!list_empty(&dequeued)) {
|
|
cr = list_entry(dequeued.next, struct cache_request, q.list);
|
|
list_del(&cr->q.list);
|
|
cache_put(cr->item, detail);
|
|
kfree(cr->buf);
|
|
kfree(cr);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
int ret;
|
|
|
|
if (len < 0) return;
|
|
|
|
ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
|
|
if (ret >= len) {
|
|
bp += len;
|
|
len = -1;
|
|
} else {
|
|
bp += ret;
|
|
len -= ret;
|
|
*bp++ = ' ';
|
|
len--;
|
|
}
|
|
*bpp = bp;
|
|
*lp = len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(qword_add);
|
|
|
|
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) {
|
|
bp = hex_byte_pack(bp, *buf++);
|
|
len -= 2;
|
|
blen--;
|
|
}
|
|
}
|
|
if (blen || len<1) len = -1;
|
|
else {
|
|
*bp++ = ' ';
|
|
len--;
|
|
}
|
|
*bpp = bp;
|
|
*lp = len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(qword_addhex);
|
|
|
|
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, detail->last_close != 0);
|
|
}
|
|
}
|
|
|
|
static bool cache_listeners_exist(struct cache_detail *detail)
|
|
{
|
|
if (atomic_read(&detail->writers))
|
|
return true;
|
|
if (detail->last_close == 0)
|
|
/* This cache was never opened */
|
|
return false;
|
|
if (detail->last_close < seconds_since_boot() - 30)
|
|
/*
|
|
* We allow for the possibility that someone might
|
|
* restart a userspace daemon without restarting the
|
|
* server; but after 30 seconds, we give up.
|
|
*/
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* register an upcall request to user-space and queue it up for read() by the
|
|
* upcall daemon.
|
|
*
|
|
* Each request is at most one page long.
|
|
*/
|
|
static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
|
|
{
|
|
char *buf;
|
|
struct cache_request *crq;
|
|
int ret = 0;
|
|
|
|
if (test_bit(CACHE_CLEANED, &h->flags))
|
|
/* Too late to make an upcall */
|
|
return -EAGAIN;
|
|
|
|
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!buf)
|
|
return -EAGAIN;
|
|
|
|
crq = kmalloc(sizeof (*crq), GFP_KERNEL);
|
|
if (!crq) {
|
|
kfree(buf);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
crq->q.reader = 0;
|
|
crq->buf = buf;
|
|
crq->len = 0;
|
|
crq->readers = 0;
|
|
spin_lock(&queue_lock);
|
|
if (test_bit(CACHE_PENDING, &h->flags)) {
|
|
crq->item = cache_get(h);
|
|
list_add_tail(&crq->q.list, &detail->queue);
|
|
trace_cache_entry_upcall(detail, h);
|
|
} else
|
|
/* Lost a race, no longer PENDING, so don't enqueue */
|
|
ret = -EAGAIN;
|
|
spin_unlock(&queue_lock);
|
|
wake_up(&queue_wait);
|
|
if (ret == -EAGAIN) {
|
|
kfree(buf);
|
|
kfree(crq);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
|
|
{
|
|
if (test_and_set_bit(CACHE_PENDING, &h->flags))
|
|
return 0;
|
|
return cache_pipe_upcall(detail, h);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
|
|
|
|
int sunrpc_cache_pipe_upcall_timeout(struct cache_detail *detail,
|
|
struct cache_head *h)
|
|
{
|
|
if (!cache_listeners_exist(detail)) {
|
|
warn_no_listener(detail);
|
|
trace_cache_entry_no_listener(detail, h);
|
|
return -EINVAL;
|
|
}
|
|
return sunrpc_cache_pipe_upcall(detail, h);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall_timeout);
|
|
|
|
/*
|
|
* 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
|
|
*/
|
|
|
|
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 (len < bufsize - 1) {
|
|
int h, l;
|
|
|
|
h = hex_to_bin(bp[0]);
|
|
if (h < 0)
|
|
break;
|
|
|
|
l = hex_to_bin(bp[1]);
|
|
if (l < 0)
|
|
break;
|
|
|
|
*dest++ = (h << 4) | l;
|
|
bp += 2;
|
|
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;
|
|
}
|
|
EXPORT_SYMBOL_GPL(qword_get);
|
|
|
|
|
|
/*
|
|
* support /proc/net/rpc/$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
|
|
*/
|
|
|
|
static void *__cache_seq_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
loff_t n = *pos;
|
|
unsigned int hash, entry;
|
|
struct cache_head *ch;
|
|
struct cache_detail *cd = m->private;
|
|
|
|
if (!n--)
|
|
return SEQ_START_TOKEN;
|
|
hash = n >> 32;
|
|
entry = n & ((1LL<<32) - 1);
|
|
|
|
hlist_for_each_entry_rcu(ch, &cd->hash_table[hash], cache_list)
|
|
if (!entry--)
|
|
return ch;
|
|
n &= ~((1LL<<32) - 1);
|
|
do {
|
|
hash++;
|
|
n += 1LL<<32;
|
|
} while(hash < cd->hash_size &&
|
|
hlist_empty(&cd->hash_table[hash]));
|
|
if (hash >= cd->hash_size)
|
|
return NULL;
|
|
*pos = n+1;
|
|
return hlist_entry_safe(rcu_dereference_raw(
|
|
hlist_first_rcu(&cd->hash_table[hash])),
|
|
struct cache_head, cache_list);
|
|
}
|
|
|
|
static void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
|
|
{
|
|
struct cache_head *ch = p;
|
|
int hash = (*pos >> 32);
|
|
struct cache_detail *cd = m->private;
|
|
|
|
if (p == SEQ_START_TOKEN)
|
|
hash = 0;
|
|
else if (ch->cache_list.next == NULL) {
|
|
hash++;
|
|
*pos += 1LL<<32;
|
|
} else {
|
|
++*pos;
|
|
return hlist_entry_safe(rcu_dereference_raw(
|
|
hlist_next_rcu(&ch->cache_list)),
|
|
struct cache_head, cache_list);
|
|
}
|
|
*pos &= ~((1LL<<32) - 1);
|
|
while (hash < cd->hash_size &&
|
|
hlist_empty(&cd->hash_table[hash])) {
|
|
hash++;
|
|
*pos += 1LL<<32;
|
|
}
|
|
if (hash >= cd->hash_size)
|
|
return NULL;
|
|
++*pos;
|
|
return hlist_entry_safe(rcu_dereference_raw(
|
|
hlist_first_rcu(&cd->hash_table[hash])),
|
|
struct cache_head, cache_list);
|
|
}
|
|
|
|
void *cache_seq_start_rcu(struct seq_file *m, loff_t *pos)
|
|
__acquires(RCU)
|
|
{
|
|
rcu_read_lock();
|
|
return __cache_seq_start(m, pos);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_seq_start_rcu);
|
|
|
|
void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos)
|
|
{
|
|
return cache_seq_next(file, p, pos);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_seq_next_rcu);
|
|
|
|
void cache_seq_stop_rcu(struct seq_file *m, void *p)
|
|
__releases(RCU)
|
|
{
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_seq_stop_rcu);
|
|
|
|
static int c_show(struct seq_file *m, void *p)
|
|
{
|
|
struct cache_head *cp = p;
|
|
struct cache_detail *cd = m->private;
|
|
|
|
if (p == SEQ_START_TOKEN)
|
|
return cd->cache_show(m, cd, NULL);
|
|
|
|
ifdebug(CACHE)
|
|
seq_printf(m, "# expiry=%lld refcnt=%d flags=%lx\n",
|
|
convert_to_wallclock(cp->expiry_time),
|
|
kref_read(&cp->ref), cp->flags);
|
|
cache_get(cp);
|
|
if (cache_check(cd, cp, NULL))
|
|
/* cache_check does a cache_put on failure */
|
|
seq_printf(m, "# ");
|
|
else {
|
|
if (cache_is_expired(cd, cp))
|
|
seq_printf(m, "# ");
|
|
cache_put(cp, cd);
|
|
}
|
|
|
|
return cd->cache_show(m, cd, cp);
|
|
}
|
|
|
|
static const struct seq_operations cache_content_op = {
|
|
.start = cache_seq_start_rcu,
|
|
.next = cache_seq_next_rcu,
|
|
.stop = cache_seq_stop_rcu,
|
|
.show = c_show,
|
|
};
|
|
|
|
static int content_open(struct inode *inode, struct file *file,
|
|
struct cache_detail *cd)
|
|
{
|
|
struct seq_file *seq;
|
|
int err;
|
|
|
|
if (!cd || !try_module_get(cd->owner))
|
|
return -EACCES;
|
|
|
|
err = seq_open(file, &cache_content_op);
|
|
if (err) {
|
|
module_put(cd->owner);
|
|
return err;
|
|
}
|
|
|
|
seq = file->private_data;
|
|
seq->private = cd;
|
|
return 0;
|
|
}
|
|
|
|
static int content_release(struct inode *inode, struct file *file,
|
|
struct cache_detail *cd)
|
|
{
|
|
int ret = seq_release(inode, file);
|
|
module_put(cd->owner);
|
|
return ret;
|
|
}
|
|
|
|
static int open_flush(struct inode *inode, struct file *file,
|
|
struct cache_detail *cd)
|
|
{
|
|
if (!cd || !try_module_get(cd->owner))
|
|
return -EACCES;
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int release_flush(struct inode *inode, struct file *file,
|
|
struct cache_detail *cd)
|
|
{
|
|
module_put(cd->owner);
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t read_flush(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos,
|
|
struct cache_detail *cd)
|
|
{
|
|
char tbuf[22];
|
|
size_t len;
|
|
|
|
len = snprintf(tbuf, sizeof(tbuf), "%llu\n",
|
|
convert_to_wallclock(cd->flush_time));
|
|
return simple_read_from_buffer(buf, count, ppos, tbuf, len);
|
|
}
|
|
|
|
static ssize_t write_flush(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos,
|
|
struct cache_detail *cd)
|
|
{
|
|
char tbuf[20];
|
|
char *ep;
|
|
time64_t now;
|
|
|
|
if (*ppos || count > sizeof(tbuf)-1)
|
|
return -EINVAL;
|
|
if (copy_from_user(tbuf, buf, count))
|
|
return -EFAULT;
|
|
tbuf[count] = 0;
|
|
simple_strtoul(tbuf, &ep, 0);
|
|
if (*ep && *ep != '\n')
|
|
return -EINVAL;
|
|
/* Note that while we check that 'buf' holds a valid number,
|
|
* we always ignore the value and just flush everything.
|
|
* Making use of the number leads to races.
|
|
*/
|
|
|
|
now = seconds_since_boot();
|
|
/* Always flush everything, so behave like cache_purge()
|
|
* Do this by advancing flush_time to the current time,
|
|
* or by one second if it has already reached the current time.
|
|
* Newly added cache entries will always have ->last_refresh greater
|
|
* that ->flush_time, so they don't get flushed prematurely.
|
|
*/
|
|
|
|
if (cd->flush_time >= now)
|
|
now = cd->flush_time + 1;
|
|
|
|
cd->flush_time = now;
|
|
cd->nextcheck = now;
|
|
cache_flush();
|
|
|
|
if (cd->flush)
|
|
cd->flush();
|
|
|
|
*ppos += count;
|
|
return count;
|
|
}
|
|
|
|
static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(file_inode(filp));
|
|
|
|
return cache_read(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(file_inode(filp));
|
|
|
|
return cache_write(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static __poll_t cache_poll_procfs(struct file *filp, poll_table *wait)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(file_inode(filp));
|
|
|
|
return cache_poll(filp, wait, cd);
|
|
}
|
|
|
|
static long cache_ioctl_procfs(struct file *filp,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return cache_ioctl(inode, filp, cmd, arg, cd);
|
|
}
|
|
|
|
static int cache_open_procfs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return cache_open(inode, filp, cd);
|
|
}
|
|
|
|
static int cache_release_procfs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return cache_release(inode, filp, cd);
|
|
}
|
|
|
|
static const struct proc_ops cache_channel_proc_ops = {
|
|
.proc_lseek = no_llseek,
|
|
.proc_read = cache_read_procfs,
|
|
.proc_write = cache_write_procfs,
|
|
.proc_poll = cache_poll_procfs,
|
|
.proc_ioctl = cache_ioctl_procfs, /* for FIONREAD */
|
|
.proc_open = cache_open_procfs,
|
|
.proc_release = cache_release_procfs,
|
|
};
|
|
|
|
static int content_open_procfs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return content_open(inode, filp, cd);
|
|
}
|
|
|
|
static int content_release_procfs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return content_release(inode, filp, cd);
|
|
}
|
|
|
|
static const struct proc_ops content_proc_ops = {
|
|
.proc_open = content_open_procfs,
|
|
.proc_read = seq_read,
|
|
.proc_lseek = seq_lseek,
|
|
.proc_release = content_release_procfs,
|
|
};
|
|
|
|
static int open_flush_procfs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return open_flush(inode, filp, cd);
|
|
}
|
|
|
|
static int release_flush_procfs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(inode);
|
|
|
|
return release_flush(inode, filp, cd);
|
|
}
|
|
|
|
static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(file_inode(filp));
|
|
|
|
return read_flush(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static ssize_t write_flush_procfs(struct file *filp,
|
|
const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = PDE_DATA(file_inode(filp));
|
|
|
|
return write_flush(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static const struct proc_ops cache_flush_proc_ops = {
|
|
.proc_open = open_flush_procfs,
|
|
.proc_read = read_flush_procfs,
|
|
.proc_write = write_flush_procfs,
|
|
.proc_release = release_flush_procfs,
|
|
.proc_lseek = no_llseek,
|
|
};
|
|
|
|
static void remove_cache_proc_entries(struct cache_detail *cd)
|
|
{
|
|
if (cd->procfs) {
|
|
proc_remove(cd->procfs);
|
|
cd->procfs = NULL;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
|
|
{
|
|
struct proc_dir_entry *p;
|
|
struct sunrpc_net *sn;
|
|
|
|
sn = net_generic(net, sunrpc_net_id);
|
|
cd->procfs = proc_mkdir(cd->name, sn->proc_net_rpc);
|
|
if (cd->procfs == NULL)
|
|
goto out_nomem;
|
|
|
|
p = proc_create_data("flush", S_IFREG | 0600,
|
|
cd->procfs, &cache_flush_proc_ops, cd);
|
|
if (p == NULL)
|
|
goto out_nomem;
|
|
|
|
if (cd->cache_request || cd->cache_parse) {
|
|
p = proc_create_data("channel", S_IFREG | 0600, cd->procfs,
|
|
&cache_channel_proc_ops, cd);
|
|
if (p == NULL)
|
|
goto out_nomem;
|
|
}
|
|
if (cd->cache_show) {
|
|
p = proc_create_data("content", S_IFREG | 0400, cd->procfs,
|
|
&content_proc_ops, cd);
|
|
if (p == NULL)
|
|
goto out_nomem;
|
|
}
|
|
return 0;
|
|
out_nomem:
|
|
remove_cache_proc_entries(cd);
|
|
return -ENOMEM;
|
|
}
|
|
#else /* CONFIG_PROC_FS */
|
|
static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
void __init cache_initialize(void)
|
|
{
|
|
INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
|
|
}
|
|
|
|
int cache_register_net(struct cache_detail *cd, struct net *net)
|
|
{
|
|
int ret;
|
|
|
|
sunrpc_init_cache_detail(cd);
|
|
ret = create_cache_proc_entries(cd, net);
|
|
if (ret)
|
|
sunrpc_destroy_cache_detail(cd);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_register_net);
|
|
|
|
void cache_unregister_net(struct cache_detail *cd, struct net *net)
|
|
{
|
|
remove_cache_proc_entries(cd);
|
|
sunrpc_destroy_cache_detail(cd);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_unregister_net);
|
|
|
|
struct cache_detail *cache_create_net(const struct cache_detail *tmpl, struct net *net)
|
|
{
|
|
struct cache_detail *cd;
|
|
int i;
|
|
|
|
cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
|
|
if (cd == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
cd->hash_table = kcalloc(cd->hash_size, sizeof(struct hlist_head),
|
|
GFP_KERNEL);
|
|
if (cd->hash_table == NULL) {
|
|
kfree(cd);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
for (i = 0; i < cd->hash_size; i++)
|
|
INIT_HLIST_HEAD(&cd->hash_table[i]);
|
|
cd->net = net;
|
|
return cd;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_create_net);
|
|
|
|
void cache_destroy_net(struct cache_detail *cd, struct net *net)
|
|
{
|
|
kfree(cd->hash_table);
|
|
kfree(cd);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cache_destroy_net);
|
|
|
|
static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
|
|
|
|
return cache_read(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
|
|
|
|
return cache_write(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static __poll_t cache_poll_pipefs(struct file *filp, poll_table *wait)
|
|
{
|
|
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
|
|
|
|
return cache_poll(filp, wait, cd);
|
|
}
|
|
|
|
static long cache_ioctl_pipefs(struct file *filp,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return cache_ioctl(inode, filp, cmd, arg, cd);
|
|
}
|
|
|
|
static int cache_open_pipefs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return cache_open(inode, filp, cd);
|
|
}
|
|
|
|
static int cache_release_pipefs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return cache_release(inode, filp, cd);
|
|
}
|
|
|
|
const struct file_operations cache_file_operations_pipefs = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.read = cache_read_pipefs,
|
|
.write = cache_write_pipefs,
|
|
.poll = cache_poll_pipefs,
|
|
.unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
|
|
.open = cache_open_pipefs,
|
|
.release = cache_release_pipefs,
|
|
};
|
|
|
|
static int content_open_pipefs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return content_open(inode, filp, cd);
|
|
}
|
|
|
|
static int content_release_pipefs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return content_release(inode, filp, cd);
|
|
}
|
|
|
|
const struct file_operations content_file_operations_pipefs = {
|
|
.open = content_open_pipefs,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = content_release_pipefs,
|
|
};
|
|
|
|
static int open_flush_pipefs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return open_flush(inode, filp, cd);
|
|
}
|
|
|
|
static int release_flush_pipefs(struct inode *inode, struct file *filp)
|
|
{
|
|
struct cache_detail *cd = RPC_I(inode)->private;
|
|
|
|
return release_flush(inode, filp, cd);
|
|
}
|
|
|
|
static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
|
|
|
|
return read_flush(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
static ssize_t write_flush_pipefs(struct file *filp,
|
|
const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct cache_detail *cd = RPC_I(file_inode(filp))->private;
|
|
|
|
return write_flush(filp, buf, count, ppos, cd);
|
|
}
|
|
|
|
const struct file_operations cache_flush_operations_pipefs = {
|
|
.open = open_flush_pipefs,
|
|
.read = read_flush_pipefs,
|
|
.write = write_flush_pipefs,
|
|
.release = release_flush_pipefs,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
int sunrpc_cache_register_pipefs(struct dentry *parent,
|
|
const char *name, umode_t umode,
|
|
struct cache_detail *cd)
|
|
{
|
|
struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd);
|
|
if (IS_ERR(dir))
|
|
return PTR_ERR(dir);
|
|
cd->pipefs = dir;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
|
|
|
|
void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
|
|
{
|
|
if (cd->pipefs) {
|
|
rpc_remove_cache_dir(cd->pipefs);
|
|
cd->pipefs = NULL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
|
|
|
|
void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h)
|
|
{
|
|
spin_lock(&cd->hash_lock);
|
|
if (!hlist_unhashed(&h->cache_list)){
|
|
sunrpc_begin_cache_remove_entry(h, cd);
|
|
spin_unlock(&cd->hash_lock);
|
|
sunrpc_end_cache_remove_entry(h, cd);
|
|
} else
|
|
spin_unlock(&cd->hash_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sunrpc_cache_unhash);
|