437 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			437 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Internal definitions for FS-Cache
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 *
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 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
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 * Written by David Howells (dhowells@redhat.com)
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License
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 * as published by the Free Software Foundation; either version
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 * 2 of the License, or (at your option) any later version.
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 */
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/*
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 * Lock order, in the order in which multiple locks should be obtained:
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 * - fscache_addremove_sem
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 * - cookie->lock
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 * - cookie->parent->lock
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 * - cache->object_list_lock
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 * - object->lock
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 * - object->parent->lock
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 * - cookie->stores_lock
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 * - fscache_thread_lock
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 *
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 */
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#include <linux/fscache-cache.h>
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#include <linux/sched.h>
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#define FSCACHE_MIN_THREADS	4
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#define FSCACHE_MAX_THREADS	32
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/*
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 * cache.c
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 */
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extern struct list_head fscache_cache_list;
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extern struct rw_semaphore fscache_addremove_sem;
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extern struct fscache_cache *fscache_select_cache_for_object(
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	struct fscache_cookie *);
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/*
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 * cookie.c
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 */
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extern struct kmem_cache *fscache_cookie_jar;
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extern void fscache_cookie_init_once(void *);
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extern void __fscache_cookie_put(struct fscache_cookie *);
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/*
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 * fsdef.c
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 */
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extern struct fscache_cookie fscache_fsdef_index;
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extern struct fscache_cookie_def fscache_fsdef_netfs_def;
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/*
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 * histogram.c
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 */
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#ifdef CONFIG_FSCACHE_HISTOGRAM
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extern atomic_t fscache_obj_instantiate_histogram[HZ];
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extern atomic_t fscache_objs_histogram[HZ];
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extern atomic_t fscache_ops_histogram[HZ];
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extern atomic_t fscache_retrieval_delay_histogram[HZ];
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extern atomic_t fscache_retrieval_histogram[HZ];
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static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
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{
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	unsigned long jif = jiffies - start_jif;
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	if (jif >= HZ)
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		jif = HZ - 1;
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	atomic_inc(&histogram[jif]);
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}
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extern const struct file_operations fscache_histogram_fops;
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#else
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#define fscache_hist(hist, start_jif) do {} while (0)
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#endif
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/*
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 * main.c
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 */
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extern unsigned fscache_defer_lookup;
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extern unsigned fscache_defer_create;
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extern unsigned fscache_debug;
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extern struct kobject *fscache_root;
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extern int fscache_wait_bit(void *);
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extern int fscache_wait_bit_interruptible(void *);
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/*
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 * object.c
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 */
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extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
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extern void fscache_withdrawing_object(struct fscache_cache *,
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				       struct fscache_object *);
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extern void fscache_enqueue_object(struct fscache_object *);
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/*
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 * object-list.c
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 */
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#ifdef CONFIG_FSCACHE_OBJECT_LIST
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extern const struct file_operations fscache_objlist_fops;
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extern void fscache_objlist_add(struct fscache_object *);
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#else
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#define fscache_objlist_add(object) do {} while(0)
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#endif
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/*
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 * operation.c
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 */
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extern int fscache_submit_exclusive_op(struct fscache_object *,
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				       struct fscache_operation *);
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extern int fscache_submit_op(struct fscache_object *,
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			     struct fscache_operation *);
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extern int fscache_cancel_op(struct fscache_operation *);
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extern void fscache_abort_object(struct fscache_object *);
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extern void fscache_start_operations(struct fscache_object *);
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extern void fscache_operation_gc(struct work_struct *);
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/*
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 * proc.c
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 */
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#ifdef CONFIG_PROC_FS
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extern int __init fscache_proc_init(void);
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extern void fscache_proc_cleanup(void);
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#else
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#define fscache_proc_init()	(0)
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#define fscache_proc_cleanup()	do {} while (0)
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#endif
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/*
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 * stats.c
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 */
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#ifdef CONFIG_FSCACHE_STATS
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extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
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extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
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extern atomic_t fscache_n_op_pend;
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extern atomic_t fscache_n_op_run;
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extern atomic_t fscache_n_op_enqueue;
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extern atomic_t fscache_n_op_deferred_release;
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extern atomic_t fscache_n_op_release;
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extern atomic_t fscache_n_op_gc;
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extern atomic_t fscache_n_op_cancelled;
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extern atomic_t fscache_n_op_rejected;
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extern atomic_t fscache_n_attr_changed;
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extern atomic_t fscache_n_attr_changed_ok;
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extern atomic_t fscache_n_attr_changed_nobufs;
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extern atomic_t fscache_n_attr_changed_nomem;
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extern atomic_t fscache_n_attr_changed_calls;
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extern atomic_t fscache_n_allocs;
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extern atomic_t fscache_n_allocs_ok;
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extern atomic_t fscache_n_allocs_wait;
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extern atomic_t fscache_n_allocs_nobufs;
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extern atomic_t fscache_n_allocs_intr;
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extern atomic_t fscache_n_allocs_object_dead;
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extern atomic_t fscache_n_alloc_ops;
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extern atomic_t fscache_n_alloc_op_waits;
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extern atomic_t fscache_n_retrievals;
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extern atomic_t fscache_n_retrievals_ok;
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extern atomic_t fscache_n_retrievals_wait;
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extern atomic_t fscache_n_retrievals_nodata;
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extern atomic_t fscache_n_retrievals_nobufs;
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extern atomic_t fscache_n_retrievals_intr;
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extern atomic_t fscache_n_retrievals_nomem;
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extern atomic_t fscache_n_retrievals_object_dead;
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extern atomic_t fscache_n_retrieval_ops;
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extern atomic_t fscache_n_retrieval_op_waits;
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extern atomic_t fscache_n_stores;
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extern atomic_t fscache_n_stores_ok;
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extern atomic_t fscache_n_stores_again;
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extern atomic_t fscache_n_stores_nobufs;
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extern atomic_t fscache_n_stores_oom;
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extern atomic_t fscache_n_store_ops;
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extern atomic_t fscache_n_store_calls;
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extern atomic_t fscache_n_store_pages;
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extern atomic_t fscache_n_store_radix_deletes;
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extern atomic_t fscache_n_store_pages_over_limit;
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extern atomic_t fscache_n_store_vmscan_not_storing;
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extern atomic_t fscache_n_store_vmscan_gone;
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extern atomic_t fscache_n_store_vmscan_busy;
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extern atomic_t fscache_n_store_vmscan_cancelled;
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extern atomic_t fscache_n_marks;
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extern atomic_t fscache_n_uncaches;
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extern atomic_t fscache_n_acquires;
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extern atomic_t fscache_n_acquires_null;
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extern atomic_t fscache_n_acquires_no_cache;
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extern atomic_t fscache_n_acquires_ok;
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extern atomic_t fscache_n_acquires_nobufs;
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extern atomic_t fscache_n_acquires_oom;
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extern atomic_t fscache_n_updates;
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extern atomic_t fscache_n_updates_null;
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extern atomic_t fscache_n_updates_run;
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extern atomic_t fscache_n_relinquishes;
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extern atomic_t fscache_n_relinquishes_null;
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extern atomic_t fscache_n_relinquishes_waitcrt;
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extern atomic_t fscache_n_relinquishes_retire;
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extern atomic_t fscache_n_cookie_index;
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extern atomic_t fscache_n_cookie_data;
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extern atomic_t fscache_n_cookie_special;
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extern atomic_t fscache_n_object_alloc;
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extern atomic_t fscache_n_object_no_alloc;
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extern atomic_t fscache_n_object_lookups;
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extern atomic_t fscache_n_object_lookups_negative;
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extern atomic_t fscache_n_object_lookups_positive;
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extern atomic_t fscache_n_object_lookups_timed_out;
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extern atomic_t fscache_n_object_created;
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extern atomic_t fscache_n_object_avail;
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extern atomic_t fscache_n_object_dead;
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extern atomic_t fscache_n_checkaux_none;
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extern atomic_t fscache_n_checkaux_okay;
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extern atomic_t fscache_n_checkaux_update;
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extern atomic_t fscache_n_checkaux_obsolete;
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extern atomic_t fscache_n_cop_alloc_object;
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extern atomic_t fscache_n_cop_lookup_object;
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extern atomic_t fscache_n_cop_lookup_complete;
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extern atomic_t fscache_n_cop_grab_object;
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extern atomic_t fscache_n_cop_update_object;
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extern atomic_t fscache_n_cop_drop_object;
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extern atomic_t fscache_n_cop_put_object;
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extern atomic_t fscache_n_cop_sync_cache;
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extern atomic_t fscache_n_cop_attr_changed;
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extern atomic_t fscache_n_cop_read_or_alloc_page;
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extern atomic_t fscache_n_cop_read_or_alloc_pages;
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extern atomic_t fscache_n_cop_allocate_page;
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extern atomic_t fscache_n_cop_allocate_pages;
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extern atomic_t fscache_n_cop_write_page;
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extern atomic_t fscache_n_cop_uncache_page;
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extern atomic_t fscache_n_cop_dissociate_pages;
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static inline void fscache_stat(atomic_t *stat)
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{
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	atomic_inc(stat);
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}
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static inline void fscache_stat_d(atomic_t *stat)
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{
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	atomic_dec(stat);
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}
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#define __fscache_stat(stat) (stat)
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extern const struct file_operations fscache_stats_fops;
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#else
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#define __fscache_stat(stat) (NULL)
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#define fscache_stat(stat) do {} while (0)
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#define fscache_stat_d(stat) do {} while (0)
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#endif
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/*
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 * raise an event on an object
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 * - if the event is not masked for that object, then the object is
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 *   queued for attention by the thread pool.
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 */
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static inline void fscache_raise_event(struct fscache_object *object,
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				       unsigned event)
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{
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	if (!test_and_set_bit(event, &object->events) &&
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	    test_bit(event, &object->event_mask))
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		fscache_enqueue_object(object);
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}
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/*
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 * drop a reference to a cookie
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 */
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static inline void fscache_cookie_put(struct fscache_cookie *cookie)
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{
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	BUG_ON(atomic_read(&cookie->usage) <= 0);
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	if (atomic_dec_and_test(&cookie->usage))
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		__fscache_cookie_put(cookie);
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}
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/*
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 * get an extra reference to a netfs retrieval context
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 */
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static inline
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void *fscache_get_context(struct fscache_cookie *cookie, void *context)
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{
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	if (cookie->def->get_context)
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		cookie->def->get_context(cookie->netfs_data, context);
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	return context;
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}
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/*
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 * release a reference to a netfs retrieval context
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 */
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static inline
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void fscache_put_context(struct fscache_cookie *cookie, void *context)
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{
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	if (cookie->def->put_context)
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		cookie->def->put_context(cookie->netfs_data, context);
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}
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/*****************************************************************************/
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/*
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 * debug tracing
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 */
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#define dbgprintk(FMT, ...) \
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	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
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/* make sure we maintain the format strings, even when debugging is disabled */
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static inline __attribute__((format(printf, 1, 2)))
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void _dbprintk(const char *fmt, ...)
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{
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}
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#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
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#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
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#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
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#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
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#ifdef __KDEBUG
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#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
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#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
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#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
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#elif defined(CONFIG_FSCACHE_DEBUG)
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#define _enter(FMT, ...)			\
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do {						\
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	if (__do_kdebug(ENTER))			\
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		kenter(FMT, ##__VA_ARGS__);	\
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} while (0)
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#define _leave(FMT, ...)			\
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do {						\
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	if (__do_kdebug(LEAVE))			\
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		kleave(FMT, ##__VA_ARGS__);	\
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} while (0)
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#define _debug(FMT, ...)			\
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do {						\
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	if (__do_kdebug(DEBUG))			\
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		kdebug(FMT, ##__VA_ARGS__);	\
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} while (0)
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#else
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#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
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#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
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#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
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#endif
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/*
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 * determine whether a particular optional debugging point should be logged
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 * - we need to go through three steps to persuade cpp to correctly join the
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 *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
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 */
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#define ____do_kdebug(LEVEL, POINT) \
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	unlikely((fscache_debug & \
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		  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
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#define ___do_kdebug(LEVEL, POINT) \
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	____do_kdebug(LEVEL, POINT)
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#define __do_kdebug(POINT) \
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	___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
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#define FSCACHE_DEBUG_CACHE	0
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#define FSCACHE_DEBUG_COOKIE	1
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#define FSCACHE_DEBUG_PAGE	2
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#define FSCACHE_DEBUG_OPERATION	3
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#define FSCACHE_POINT_ENTER	1
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#define FSCACHE_POINT_LEAVE	2
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#define FSCACHE_POINT_DEBUG	4
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#ifndef FSCACHE_DEBUG_LEVEL
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#define FSCACHE_DEBUG_LEVEL CACHE
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#endif
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/*
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 * assertions
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 */
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#if 1 /* defined(__KDEBUGALL) */
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#define ASSERT(X)							\
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do {									\
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	if (unlikely(!(X))) {						\
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		printk(KERN_ERR "\n");					\
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		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
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		BUG();							\
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	}								\
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} while (0)
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#define ASSERTCMP(X, OP, Y)						\
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do {									\
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	if (unlikely(!((X) OP (Y)))) {					\
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		printk(KERN_ERR "\n");					\
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		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
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		printk(KERN_ERR "%lx " #OP " %lx is false\n",		\
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		       (unsigned long)(X), (unsigned long)(Y));		\
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		BUG();							\
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	}								\
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} while (0)
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#define ASSERTIF(C, X)							\
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do {									\
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	if (unlikely((C) && !(X))) {					\
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		printk(KERN_ERR "\n");					\
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		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
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		BUG();							\
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	}								\
 | 
						|
} while (0)
 | 
						|
 | 
						|
#define ASSERTIFCMP(C, X, OP, Y)					\
 | 
						|
do {									\
 | 
						|
	if (unlikely((C) && !((X) OP (Y)))) {				\
 | 
						|
		printk(KERN_ERR "\n");					\
 | 
						|
		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
 | 
						|
		printk(KERN_ERR "%lx " #OP " %lx is false\n",		\
 | 
						|
		       (unsigned long)(X), (unsigned long)(Y));		\
 | 
						|
		BUG();							\
 | 
						|
	}								\
 | 
						|
} while (0)
 | 
						|
 | 
						|
#else
 | 
						|
 | 
						|
#define ASSERT(X)			do {} while (0)
 | 
						|
#define ASSERTCMP(X, OP, Y)		do {} while (0)
 | 
						|
#define ASSERTIF(C, X)			do {} while (0)
 | 
						|
#define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
 | 
						|
 | 
						|
#endif /* assert or not */
 |