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1902 lines
46 KiB
1902 lines
46 KiB
// 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 <[email protected]> |
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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 <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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|
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#define RPCDBG_FACILITY RPCDBG_CACHE |
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|
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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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|
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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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|
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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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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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spin_lock(&detail->hash_lock); |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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spin_lock(&cache_list_lock); |
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|
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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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|
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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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|
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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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|
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spin_lock(¤t_detail->hash_lock); |
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|
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/* Ok, now to clean this strand */ |
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|
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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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|
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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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|
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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; |
|
|
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if (list_empty(&cache_list)) |
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return; |
|
|
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if (cache_clean() == -1) |
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delay = round_jiffies_relative(30*HZ); |
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else |
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delay = 5; |
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|
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queue_delayed_work(system_power_efficient_wq, &cache_cleaner, delay); |
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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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EXPORT_SYMBOL_GPL(cache_flush); |
|
|
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void cache_purge(struct cache_detail *detail) |
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{ |
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struct cache_head *ch = NULL; |
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struct hlist_head *head = NULL; |
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int i = 0; |
|
|
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spin_lock(&detail->hash_lock); |
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if (!detail->entries) { |
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spin_unlock(&detail->hash_lock); |
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return; |
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} |
|
|
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dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name); |
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for (i = 0; i < detail->hash_size; i++) { |
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head = &detail->hash_table[i]; |
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while (!hlist_empty(head)) { |
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ch = hlist_entry(head->first, struct cache_head, |
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cache_list); |
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sunrpc_begin_cache_remove_entry(ch, detail); |
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spin_unlock(&detail->hash_lock); |
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sunrpc_end_cache_remove_entry(ch, detail); |
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spin_lock(&detail->hash_lock); |
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} |
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} |
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spin_unlock(&detail->hash_lock); |
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} |
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EXPORT_SYMBOL_GPL(cache_purge); |
|
|
|
|
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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. |
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* All deferred requests are stored in a hash table, |
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* indexed by "struct cache_head *". |
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* As it may be wasteful to store a whole request |
|
* structure, we allow the request to provide a |
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* deferred form, which must contain a |
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* 'struct cache_deferred_req' |
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* This cache_deferred_req contains a method to allow |
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* it to be revisited when cache info is available |
|
*/ |
|
|
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#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) |
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#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) |
|
|
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#define DFR_MAX 300 /* ??? */ |
|
|
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static DEFINE_SPINLOCK(cache_defer_lock); |
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static LIST_HEAD(cache_defer_list); |
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static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; |
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static int cache_defer_cnt; |
|
|
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static void __unhash_deferred_req(struct cache_deferred_req *dreq) |
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{ |
|
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); |
|
|
|
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 -E2BIG; |
|
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_downcall(struct address_space *mapping, |
|
const char __user *buf, |
|
size_t count, struct cache_detail *cd) |
|
{ |
|
char *write_buf; |
|
ssize_t ret = -ENOMEM; |
|
|
|
if (count >= 32768) { /* 32k is max userland buffer, lets check anyway */ |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
write_buf = kvmalloc(count + 1, GFP_KERNEL); |
|
if (!write_buf) |
|
goto out; |
|
|
|
ret = cache_do_downcall(write_buf, buf, count, cd); |
|
kvfree(write_buf); |
|
out: |
|
return ret; |
|
} |
|
|
|
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_puts(m, "# "); |
|
else { |
|
if (cache_is_expired(cd, cp)) |
|
seq_puts(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);
|
|
|