120 lines
4.8 KiB
C
120 lines
4.8 KiB
C
/* $NetBSD: tmpfs_pool.h,v 1.6 2006/11/09 16:20:56 jmmv Exp $ */
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/*
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* Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Julio M. Merino Vidal, developed as part of Google's Summer of Code
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* 2005 program.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _FS_TMPFS_TMPFS_POOL_H_
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#define _FS_TMPFS_TMPFS_POOL_H_
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/* --------------------------------------------------------------------- */
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/*
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* tmpfs_pool is an extension of regular system pools to also hold data
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* specific to tmpfs. More specifically, we want a pointer to the
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* tmpfs_mount structure using the pool so that we can update its memory
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* usage statistics.
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*/
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struct tmpfs_pool {
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struct pool tp_pool;
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/* Reference to the mount point that holds the pool. This is used
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* by the tmpfs_pool_allocator to access and modify the memory
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* accounting variables for the mount point. */
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struct tmpfs_mount * tp_mount;
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/* The pool's name. Used as the wait channel. */
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char tp_name[64];
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};
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/* --------------------------------------------------------------------- */
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/*
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* tmpfs uses variable-length strings to store file names and to store
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* link targets. Reserving a fixed-size buffer for each of them is
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* inefficient because it will consume a lot more memory than is really
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* necessary. However, managing variable-sized buffers is difficult as
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* regards memory allocation and very inefficient in computation time.
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* This is why tmpfs provides an hybrid scheme to store strings: string
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* pools.
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*
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* A string pool is a collection of memory pools, each one with elements
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* of a fixed size. In tmpfs's case, a string pool contains independent
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* memory pools for 16-byte, 32-byte, 64-byte, 128-byte, 256-byte,
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* 512-byte and 1024-byte long objects. Whenever an object is requested
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* from the pool, the new object's size is rounded to the closest upper
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* match and an item from the corresponding pool is returned.
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*/
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struct tmpfs_str_pool {
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struct tmpfs_pool tsp_pool_16;
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struct tmpfs_pool tsp_pool_32;
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struct tmpfs_pool tsp_pool_64;
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struct tmpfs_pool tsp_pool_128;
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struct tmpfs_pool tsp_pool_256;
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struct tmpfs_pool tsp_pool_512;
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struct tmpfs_pool tsp_pool_1024;
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};
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/* --------------------------------------------------------------------- */
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#ifdef _KERNEL
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/*
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* Convenience functions and macros to manipulate a tmpfs_pool.
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*/
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void tmpfs_pool_init(struct tmpfs_pool *tpp, size_t size,
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const char *what, struct tmpfs_mount *tmp);
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void tmpfs_pool_destroy(struct tmpfs_pool *tpp);
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#define TMPFS_POOL_GET(tpp, flags) pool_get((struct pool *)(tpp), flags)
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#define TMPFS_POOL_PUT(tpp, v) pool_put((struct pool *)(tpp), v)
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/* --------------------------------------------------------------------- */
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/*
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* Functions to manipulate a tmpfs_str_pool.
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*/
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void tmpfs_str_pool_init(struct tmpfs_str_pool *, struct tmpfs_mount *);
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void tmpfs_str_pool_destroy(struct tmpfs_str_pool *);
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char * tmpfs_str_pool_get(struct tmpfs_str_pool *, size_t, int);
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void tmpfs_str_pool_put(struct tmpfs_str_pool *, char *, size_t);
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#endif
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#endif /* _FS_TMPFS_TMPFS_POOL_H_ */
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