WebSVN – HelenOS – Blame – /trunk/uspace/srv/vfs/vfs.h/

Rev	Author	Line No.	Line
2520	jermar	1	/*
		2	* Copyright (c) 2007 Jakub Jermar
		3	* All rights reserved.
		4	*
		5	* Redistribution and use in source and binary forms, with or without
		6	* modification, are permitted provided that the following conditions
		7	* are met:
		8	*
		9	* - Redistributions of source code must retain the above copyright
		10	* notice, this list of conditions and the following disclaimer.
		11	* - Redistributions in binary form must reproduce the above copyright
		12	* notice, this list of conditions and the following disclaimer in the
		13	* documentation and/or other materials provided with the distribution.
		14	* - The name of the author may not be used to endorse or promote products
		15	* derived from this software without specific prior written permission.
		16	*
		17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		27	*/
		28
		29	/** @addtogroup fs
		30	* @{
		31	*/
		32
		33	#ifndef VFS_VFS_H_
		34	#define VFS_VFS_H_
		35
2523	jermar	36	#include <ipc/ipc.h>
2529	jermar	37	#include <libadt/list.h>
2540	jermar	38	#include <atomic.h>
2542	jermar	39	#include <sys/types.h>
2523	jermar	40
2535	jermar	41	#define dprintf(...) printf(__VA_ARGS__)
		42
2523	jermar	43	#define VFS_FIRST FIRST_USER_METHOD
		44
2526	jermar	45	#define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST)
		46
2520	jermar	47	typedef enum {
2523	jermar	48	VFS_REGISTER = VFS_FIRST,
2520	jermar	49	VFS_MOUNT,
		50	VFS_UNMOUNT,
2527	jermar	51	VFS_LOOKUP,
2521	jermar	52	VFS_OPEN,
2523	jermar	53	VFS_CREATE,
		54	VFS_CLOSE,
		55	VFS_READ,
		56	VFS_WRITE,
		57	VFS_SEEK,
2521	jermar	58	VFS_LAST, /* keep this the last member of the enum */
2520	jermar	59	} vfs_request_t;
		60
2521	jermar	61
		62	/**
		63	* An instance of this structure is associated with a particular FS operation.
		64	* It tells VFS if the FS supports the operation or maybe if a default one
		65	* should be used.
		66	*/
		67	typedef enum {
2523	jermar	68	VFS_OP_NULL = 0,
2521	jermar	69	VFS_OP_DEFAULT,
		70	VFS_OP_DEFINED
		71	} vfs_op_t;
		72
		73	#define FS_NAME_MAXLEN 20
		74
		75	/**
		76	* A structure like this is passed to VFS by each individual FS upon its
		77	* registration. It assosiates a human-readable identifier with each
		78	* registered FS. More importantly, through this structure, the FS announces
		79	* what operations it supports.
		80	*/
		81	typedef struct {
2523	jermar	82	/** Unique identifier of the fs. */
2526	jermar	83	char name[FS_NAME_MAXLEN];
2523	jermar	84
		85	/** Operations. */
		86	vfs_op_t ops[VFS_LAST - VFS_FIRST];
2521	jermar	87	} vfs_info_t;
		88
2540	jermar	89	/**
		90	* A structure like this will be allocated for each registered file system.
		91	*/
2526	jermar	92	typedef struct {
		93	link_t fs_link;
		94	vfs_info_t vfs_info;
2527	jermar	95	ipcarg_t phone;
2526	jermar	96	} fs_info_t;
		97
2540	jermar	98	/**
		99	* Instances of this type represent a file system node (e.g. directory, file).
		100	* They are abstracted away from any file system implementation and contain just
		101	* enough bits to uniquely identify the object in its file system instance.
		102	*
		103	* @note fs_handle, dev_handle and index are meant to be returned in one
		104	* IPC reply.
		105	*/
		106	typedef struct {
		107	int fs_handle; /*< Global file system ID. /
		108	int dev_handle; /*< Global mount device devno. /
		109	uint64_t index; /*< Index of the node on its file system. /
		110	} vfs_node_t;
		111
		112	/**
		113	* Instances of this type represent an open file. If the file is opened by more
		114	* than one task, there will be a separate structure allocated for each task.
		115	*/
		116	typedef struct {
		117	vfs_node_t *node;
		118
		119	/** Number of file handles referencing this file. */
		120	atomic_t refcnt;
		121
		122	/** Current position in the file. */
		123	off_t pos;
		124	} vfs_file_t;
		125
2542	jermar	126	extern link_t fs_head; /*< List of registered file systems. /
2535	jermar	127
2542	jermar	128	extern vfs_node_t rootfs; /< Root node of the root file system. /
2535	jermar	129
2542	jermar	130	#define MAX_PATH_LEN (64 * 1024)
		131
		132	#define PLB_SIZE (2 * MAX_PATH_LEN)
		133
		134	/** Each instance of this type describes one path lookup in progress. */
		135	typedef struct {
		136	link_t plb_link; /*< Active PLB entries list link. /
		137	unsigned index; /*< Index of the first character in PLB. /
		138	size_t len; /*< Number of characters in this PLB entry. /
		139	} plb_entry_t;
		140
		141	extern atomic_t plb_futex; /*< Futex protecting plb and plb_head. /
		142	extern uint8_t plb; /< Path Lookup Buffer /
		143	extern link_t plb_head; /*< List of active PLB entries. /
		144
		145	extern void vfs_register(ipc_callid_t, ipc_call_t *);
		146	extern void vfs_lookup(ipc_callid_t, ipc_call_t *);
		147
2520	jermar	148	#endif
		149
		150	/**
		151	* @}
2523	jermar	152	*/

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