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>
2680	jermar	39	#include <rwlock.h>
2542	jermar	40	#include <sys/types.h>
2550	cejka	41	#include <bool.h>
2523	jermar	42
2535	jermar	43	#define dprintf(...) printf(__VA_ARGS__)
		44
2550	cejka	45	#define VFS_FIRST IPC_FIRST_USER_METHOD
2523	jermar	46
2526	jermar	47	#define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST)
		48
2520	jermar	49	typedef enum {
2523	jermar	50	VFS_REGISTER = VFS_FIRST,
2520	jermar	51	VFS_MOUNT,
		52	VFS_UNMOUNT,
2527	jermar	53	VFS_LOOKUP,
2521	jermar	54	VFS_OPEN,
2523	jermar	55	VFS_CREATE,
		56	VFS_CLOSE,
		57	VFS_READ,
		58	VFS_WRITE,
		59	VFS_SEEK,
2593	jermar	60	VFS_RENAME,
		61	VFS_UNLINK,
2521	jermar	62	VFS_LAST, /* keep this the last member of the enum */
2520	jermar	63	} vfs_request_t;
		64
2521	jermar	65
		66	/**
		67	* An instance of this structure is associated with a particular FS operation.
		68	* It tells VFS if the FS supports the operation or maybe if a default one
		69	* should be used.
		70	*/
		71	typedef enum {
2523	jermar	72	VFS_OP_NULL = 0,
2521	jermar	73	VFS_OP_DEFAULT,
		74	VFS_OP_DEFINED
		75	} vfs_op_t;
		76
		77	#define FS_NAME_MAXLEN 20
		78
		79	/**
		80	* A structure like this is passed to VFS by each individual FS upon its
		81	* registration. It assosiates a human-readable identifier with each
		82	* registered FS. More importantly, through this structure, the FS announces
		83	* what operations it supports.
		84	*/
		85	typedef struct {
2523	jermar	86	/** Unique identifier of the fs. */
2641	jermar	87	char name[FS_NAME_MAXLEN + 1];
2523	jermar	88
		89	/** Operations. */
		90	vfs_op_t ops[VFS_LAST - VFS_FIRST];
2521	jermar	91	} vfs_info_t;
		92
2540	jermar	93	/**
		94	* A structure like this will be allocated for each registered file system.
		95	*/
2526	jermar	96	typedef struct {
		97	link_t fs_link;
		98	vfs_info_t vfs_info;
2546	jermar	99	int fs_handle;
		100	atomic_t phone_futex; /*< Phone serializing futex. /
2527	jermar	101	ipcarg_t phone;
2526	jermar	102	} fs_info_t;
		103
2540	jermar	104	/**
2587	jermar	105	* VFS_PAIR uniquely represents a file system instance.
		106	*/
		107	#define VFS_PAIR \
		108	int fs_handle; \
		109	int dev_handle;
		110
		111	/**
		112	* VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
		113	* doesn't contain any state. For a stateful structure, see vfs_node_t.
2540	jermar	114	*
		115	* @note fs_handle, dev_handle and index are meant to be returned in one
		116	* IPC reply.
		117	*/
2587	jermar	118	#define VFS_TRIPLET \
		119	VFS_PAIR; \
		120	uint64_t index;
		121
2540	jermar	122	typedef struct {
2587	jermar	123	VFS_PAIR;
		124	} vfs_pair_t;
		125
		126	typedef struct {
		127	VFS_TRIPLET;
		128	} vfs_triplet_t;
		129
		130	/**
		131	* Instances of this type represent an active, in-memory VFS node and any state
		132	* which may be associated with it.
		133	*/
		134	typedef struct {
		135	VFS_TRIPLET; /*< Identity of the node. /
2593	jermar	136	unsigned refcnt; /*< Usage counter. /
		137	link_t nh_link; /*< Node hash-table link. /
2679	jermar	138
2680	jermar	139	/** Holding this rwlock prevents modifications of the node's contents. */
		140	atomic_t contents_rwlock;
2540	jermar	141	} vfs_node_t;
		142
		143	/**
		144	* Instances of this type represent an open file. If the file is opened by more
		145	* than one task, there will be a separate structure allocated for each task.
		146	*/
		147	typedef struct {
		148	vfs_node_t *node;
		149
		150	/** Number of file handles referencing this file. */
2593	jermar	151	unsigned refcnt;
2540	jermar	152
		153	/** Current position in the file. */
		154	off_t pos;
		155	} vfs_file_t;
		156
2542	jermar	157	extern link_t fs_head; /*< List of registered file systems. /
2535	jermar	158
2587	jermar	159	extern vfs_triplet_t rootfs; /*< Root node of the root file system. /
2535	jermar	160
2542	jermar	161	#define MAX_PATH_LEN (64 * 1024)
		162
		163	#define PLB_SIZE (2 * MAX_PATH_LEN)
		164
		165	/** Each instance of this type describes one path lookup in progress. */
		166	typedef struct {
		167	link_t plb_link; /*< Active PLB entries list link. /
		168	unsigned index; /*< Index of the first character in PLB. /
		169	size_t len; /*< Number of characters in this PLB entry. /
		170	} plb_entry_t;
		171
		172	extern atomic_t plb_futex; /*< Futex protecting plb and plb_head. /
		173	extern uint8_t plb; /< Path Lookup Buffer /
		174	extern link_t plb_head; /*< List of active PLB entries. /
		175
2681	jermar	176	/** Holding this rwlock prevents changes in file system namespace. */
		177	extern rwlock_t namespace_rwlock;
2593	jermar	178
2546	jermar	179	extern int vfs_grab_phone(int);
		180	extern void vfs_release_phone(int);
		181
2552	jermar	182	extern int fs_name_to_handle(char *, bool);
2548	jermar	183
2587	jermar	184	extern int vfs_lookup_internal(char , size_t, vfs_triplet_t , vfs_pair_t *);
2593	jermar	185
2596	jermar	186	extern bool vfs_nodes_init(void);
2590	jermar	187	extern vfs_node_t vfs_node_get(vfs_triplet_t );
2593	jermar	188	extern void vfs_node_put(vfs_node_t *);
2544	jermar	189
2596	jermar	190	#define MAX_OPEN_FILES 128
		191
2593	jermar	192	extern bool vfs_files_init(void);
		193	extern vfs_file_t *vfs_file_get(int);
		194	extern int vfs_fd_alloc(void);
		195	extern void vfs_fd_free(int);
		196
		197	extern void vfs_file_addref(vfs_file_t *);
		198	extern void vfs_file_delref(vfs_file_t *);
		199
		200	extern void vfs_node_addref(vfs_node_t *);
		201	extern void vfs_node_delref(vfs_node_t *);
		202
2542	jermar	203	extern void vfs_register(ipc_callid_t, ipc_call_t *);
2544	jermar	204	extern void vfs_mount(ipc_callid_t, ipc_call_t *);
2560	jermar	205	extern void vfs_open(ipc_callid_t, ipc_call_t *);
2625	jermar	206	extern void vfs_read(ipc_callid_t, ipc_call_t *);
2666	jermar	207	extern void vfs_write(ipc_callid_t, ipc_call_t *);
2542	jermar	208
2520	jermar	209	#endif
		210
		211	/**
		212	* @}
2523	jermar	213	*/

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