WebSVN – HelenOS – Blame – /branches/network/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,
2593	jermar	59	VFS_RENAME,
		60	VFS_UNLINK,
2521	jermar	61	VFS_LAST, /* keep this the last member of the enum */
2520	jermar	62	} vfs_request_t;
		63
2521	jermar	64
		65	/**
		66	* An instance of this structure is associated with a particular FS operation.
		67	* It tells VFS if the FS supports the operation or maybe if a default one
		68	* should be used.
		69	*/
		70	typedef enum {
2523	jermar	71	VFS_OP_NULL = 0,
2521	jermar	72	VFS_OP_DEFAULT,
		73	VFS_OP_DEFINED
		74	} vfs_op_t;
		75
		76	#define FS_NAME_MAXLEN 20
		77
		78	/**
		79	* A structure like this is passed to VFS by each individual FS upon its
		80	* registration. It assosiates a human-readable identifier with each
		81	* registered FS. More importantly, through this structure, the FS announces
		82	* what operations it supports.
		83	*/
		84	typedef struct {
2523	jermar	85	/** Unique identifier of the fs. */
2526	jermar	86	char name[FS_NAME_MAXLEN];
2523	jermar	87
		88	/** Operations. */
		89	vfs_op_t ops[VFS_LAST - VFS_FIRST];
2521	jermar	90	} vfs_info_t;
		91
2540	jermar	92	/**
		93	* A structure like this will be allocated for each registered file system.
		94	*/
2526	jermar	95	typedef struct {
		96	link_t fs_link;
		97	vfs_info_t vfs_info;
2546	jermar	98	int fs_handle;
		99	atomic_t phone_futex; /*< Phone serializing futex. /
2527	jermar	100	ipcarg_t phone;
2526	jermar	101	} fs_info_t;
		102
2540	jermar	103	/**
2587	jermar	104	* VFS_PAIR uniquely represents a file system instance.
		105	*/
		106	#define VFS_PAIR \
		107	int fs_handle; \
		108	int dev_handle;
		109
		110	/**
		111	* VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
		112	* doesn't contain any state. For a stateful structure, see vfs_node_t.
2540	jermar	113	*
		114	* @note fs_handle, dev_handle and index are meant to be returned in one
		115	* IPC reply.
		116	*/
2587	jermar	117	#define VFS_TRIPLET \
		118	VFS_PAIR; \
		119	uint64_t index;
		120
2540	jermar	121	typedef struct {
2587	jermar	122	VFS_PAIR;
		123	} vfs_pair_t;
		124
		125	typedef struct {
		126	VFS_TRIPLET;
		127	} vfs_triplet_t;
		128
		129	/**
		130	* Instances of this type represent an active, in-memory VFS node and any state
		131	* which may be associated with it.
		132	*/
		133	typedef struct {
		134	VFS_TRIPLET; /*< Identity of the node. /
2593	jermar	135	unsigned refcnt; /*< Usage counter. /
		136	link_t nh_link; /*< Node hash-table link. /
2540	jermar	137	} vfs_node_t;
		138
		139	/**
		140	* Instances of this type represent an open file. If the file is opened by more
		141	* than one task, there will be a separate structure allocated for each task.
		142	*/
		143	typedef struct {
		144	vfs_node_t *node;
		145
		146	/** Number of file handles referencing this file. */
2593	jermar	147	unsigned refcnt;
2540	jermar	148
		149	/** Current position in the file. */
		150	off_t pos;
		151	} vfs_file_t;
		152
2542	jermar	153	extern link_t fs_head; /*< List of registered file systems. /
2535	jermar	154
2587	jermar	155	extern vfs_triplet_t rootfs; /*< Root node of the root file system. /
2535	jermar	156
2542	jermar	157	#define MAX_PATH_LEN (64 * 1024)
		158
		159	#define PLB_SIZE (2 * MAX_PATH_LEN)
		160
		161	/** Each instance of this type describes one path lookup in progress. */
		162	typedef struct {
		163	link_t plb_link; /*< Active PLB entries list link. /
		164	unsigned index; /*< Index of the first character in PLB. /
		165	size_t len; /*< Number of characters in this PLB entry. /
		166	} plb_entry_t;
		167
		168	extern atomic_t plb_futex; /*< Futex protecting plb and plb_head. /
		169	extern uint8_t plb; /< Path Lookup Buffer /
		170	extern link_t plb_head; /*< List of active PLB entries. /
		171
2593	jermar	172	extern atomic_t unlink_futex; /*< VFS_{CREATE\|OPEN\|UNLINK} serialization. /
		173
2546	jermar	174	extern int vfs_grab_phone(int);
		175	extern void vfs_release_phone(int);
		176
2552	jermar	177	extern int fs_name_to_handle(char *, bool);
2548	jermar	178
2587	jermar	179	extern int vfs_lookup_internal(char , size_t, vfs_triplet_t , vfs_pair_t *);
2593	jermar	180
		181
2590	jermar	182	extern vfs_node_t vfs_node_get(vfs_triplet_t );
2593	jermar	183	extern void vfs_node_put(vfs_node_t *);
2544	jermar	184
2593	jermar	185	extern bool vfs_files_init(void);
		186	extern vfs_file_t *vfs_file_get(int);
		187	extern int vfs_fd_alloc(void);
		188	extern void vfs_fd_free(int);
		189
		190	extern void vfs_file_addref(vfs_file_t *);
		191	extern void vfs_file_delref(vfs_file_t *);
		192
		193	extern void vfs_node_addref(vfs_node_t *);
		194	extern void vfs_node_delref(vfs_node_t *);
		195
2560	jermar	196	#define MAX_OPEN_FILES 128
		197
2542	jermar	198	extern void vfs_register(ipc_callid_t, ipc_call_t *);
2544	jermar	199	extern void vfs_mount(ipc_callid_t, ipc_call_t *);
2560	jermar	200	extern void vfs_open(ipc_callid_t, ipc_call_t *);
2542	jermar	201
2520	jermar	202	#endif
		203
		204	/**
		205	* @}
2523	jermar	206	*/

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