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>
2550	cejka	40	#include <bool.h>
2523	jermar	41
2535	jermar	42	#define dprintf(...) printf(__VA_ARGS__)
		43
2550	cejka	44	#define VFS_FIRST IPC_FIRST_USER_METHOD
2523	jermar	45
2526	jermar	46	#define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST)
		47
2520	jermar	48	typedef enum {
2523	jermar	49	VFS_REGISTER = VFS_FIRST,
2520	jermar	50	VFS_MOUNT,
		51	VFS_UNMOUNT,
2527	jermar	52	VFS_LOOKUP,
2521	jermar	53	VFS_OPEN,
2523	jermar	54	VFS_CREATE,
		55	VFS_CLOSE,
		56	VFS_READ,
		57	VFS_WRITE,
		58	VFS_SEEK,
2521	jermar	59	VFS_LAST, /* keep this the last member of the enum */
2520	jermar	60	} vfs_request_t;
		61
2521	jermar	62
		63	/**
		64	* An instance of this structure is associated with a particular FS operation.
		65	* It tells VFS if the FS supports the operation or maybe if a default one
		66	* should be used.
		67	*/
		68	typedef enum {
2523	jermar	69	VFS_OP_NULL = 0,
2521	jermar	70	VFS_OP_DEFAULT,
		71	VFS_OP_DEFINED
		72	} vfs_op_t;
		73
		74	#define FS_NAME_MAXLEN 20
		75
		76	/**
		77	* A structure like this is passed to VFS by each individual FS upon its
		78	* registration. It assosiates a human-readable identifier with each
		79	* registered FS. More importantly, through this structure, the FS announces
		80	* what operations it supports.
		81	*/
		82	typedef struct {
2523	jermar	83	/** Unique identifier of the fs. */
2526	jermar	84	char name[FS_NAME_MAXLEN];
2523	jermar	85
		86	/** Operations. */
		87	vfs_op_t ops[VFS_LAST - VFS_FIRST];
2521	jermar	88	} vfs_info_t;
		89
2540	jermar	90	/**
		91	* A structure like this will be allocated for each registered file system.
		92	*/
2526	jermar	93	typedef struct {
		94	link_t fs_link;
		95	vfs_info_t vfs_info;
2546	jermar	96	int fs_handle;
		97	atomic_t phone_futex; /*< Phone serializing futex. /
2527	jermar	98	ipcarg_t phone;
2526	jermar	99	} fs_info_t;
		100
2540	jermar	101	/**
		102	* Instances of this type represent a file system node (e.g. directory, file).
		103	* They are abstracted away from any file system implementation and contain just
		104	* enough bits to uniquely identify the object in its file system instance.
		105	*
		106	* @note fs_handle, dev_handle and index are meant to be returned in one
		107	* IPC reply.
		108	*/
		109	typedef struct {
		110	int fs_handle; /*< Global file system ID. /
		111	int dev_handle; /*< Global mount device devno. /
		112	uint64_t index; /*< Index of the node on its file system. /
		113	} vfs_node_t;
		114
		115	/**
		116	* Instances of this type represent an open file. If the file is opened by more
		117	* than one task, there will be a separate structure allocated for each task.
		118	*/
		119	typedef struct {
		120	vfs_node_t *node;
		121
		122	/** Number of file handles referencing this file. */
		123	atomic_t refcnt;
		124
		125	/** Current position in the file. */
		126	off_t pos;
		127	} vfs_file_t;
		128
2542	jermar	129	extern link_t fs_head; /*< List of registered file systems. /
2535	jermar	130
2542	jermar	131	extern vfs_node_t rootfs; /< Root node of the root file system. /
2535	jermar	132
2542	jermar	133	#define MAX_PATH_LEN (64 * 1024)
		134
		135	#define PLB_SIZE (2 * MAX_PATH_LEN)
		136
		137	/** Each instance of this type describes one path lookup in progress. */
		138	typedef struct {
		139	link_t plb_link; /*< Active PLB entries list link. /
		140	unsigned index; /*< Index of the first character in PLB. /
		141	size_t len; /*< Number of characters in this PLB entry. /
		142	} plb_entry_t;
		143
		144	extern atomic_t plb_futex; /*< Futex protecting plb and plb_head. /
		145	extern uint8_t plb; /< Path Lookup Buffer /
		146	extern link_t plb_head; /*< List of active PLB entries. /
		147
2546	jermar	148	extern int vfs_grab_phone(int);
		149	extern void vfs_release_phone(int);
		150
2548	jermar	151	extern int fs_name_to_handle(char *name, bool lock);
		152
2549	jermar	153	extern int vfs_lookup_internal(char path, size_t len, vfs_node_t result,
		154	vfs_node_t *altroot);
2544	jermar	155
2542	jermar	156	extern void vfs_register(ipc_callid_t, ipc_call_t *);
2544	jermar	157	extern void vfs_mount(ipc_callid_t, ipc_call_t *);
2542	jermar	158
2520	jermar	159	#endif
		160
		161	/**
		162	* @}
2523	jermar	163	*/

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