WebSVN – HelenOS – Blame – //branches/dd/uspace/srv/vfs/vfs.h

Rev	Author	Line No.	Line
4419	trochtova	1	/*
		2	* Copyright (c) 2008 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
		36	#include <ipc/ipc.h>
		37	#include <libadt/list.h>
		38	#include <futex.h>
		39	#include <rwlock.h>
		40	#include <sys/types.h>
		41	#include <bool.h>
		42
		43	// FIXME: according to CONFIG_DEBUG
		44	// #define dprintf(...) printf(__VA_ARGS__)
		45
		46	#define dprintf(...)
		47
		48	#define VFS_FIRST IPC_FIRST_USER_METHOD
		49
		50	/* Basic types. */
		51	typedef int16_t fs_handle_t;
		52	typedef int16_t dev_handle_t;
		53	typedef uint32_t fs_index_t;
		54
		55	typedef enum {
		56	VFS_READ = VFS_FIRST,
		57	VFS_WRITE,
		58	VFS_TRUNCATE,
		59	VFS_MOUNT,
		60	VFS_UNMOUNT,
		61	VFS_LAST_CMN, /* keep this the last member of this enum */
		62	} vfs_request_cmn_t;
		63
		64	typedef enum {
		65	VFS_LOOKUP = VFS_LAST_CMN,
		66	VFS_MOUNTED,
		67	VFS_DESTROY,
		68	VFS_LAST_CLNT, /* keep this the last member of this enum */
		69	} vfs_request_clnt_t;
		70
		71	typedef enum {
		72	VFS_REGISTER = VFS_LAST_CMN,
		73	VFS_OPEN,
		74	VFS_CLOSE,
		75	VFS_SEEK,
		76	VFS_MKDIR,
		77	VFS_UNLINK,
		78	VFS_RENAME,
		79	VFS_LAST_SRV, /* keep this the last member of this enum */
		80	} vfs_request_srv_t;
		81
		82	#define FS_NAME_MAXLEN 20
		83
		84	/**
		85	* A structure like this is passed to VFS by each individual FS upon its
		86	* registration. It assosiates a human-readable identifier with each
		87	* registered FS.
		88	*/
		89	typedef struct {
		90	/** Unique identifier of the fs. */
		91	char name[FS_NAME_MAXLEN + 1];
		92	} vfs_info_t;
		93
		94	/**
		95	* A structure like this will be allocated for each registered file system.
		96	*/
		97	typedef struct {
		98	link_t fs_link;
		99	vfs_info_t vfs_info;
		100	fs_handle_t fs_handle;
		101	futex_t phone_futex; /*< Phone serializing futex. /
		102	ipcarg_t phone;
		103	} fs_info_t;
		104
		105	/**
		106	* VFS_PAIR uniquely represents a file system instance.
		107	*/
		108	#define VFS_PAIR \
		109	fs_handle_t fs_handle; \
		110	dev_handle_t dev_handle;
		111
		112	/**
		113	* VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
		114	* doesn't contain any state. For a stateful structure, see vfs_node_t.
		115	*
		116	* @note fs_handle, dev_handle and index are meant to be returned in one
		117	* IPC reply.
		118	*/
		119	#define VFS_TRIPLET \
		120	VFS_PAIR; \
		121	fs_index_t index;
		122
		123	typedef struct {
		124	VFS_PAIR;
		125	} vfs_pair_t;
		126
		127	typedef struct {
		128	VFS_TRIPLET;
		129	} vfs_triplet_t;
		130
		131	/*
		132	* Lookup flags.
		133	*/
		134	/**
		135	* No lookup flags used.
		136	*/
		137	#define L_NONE 0
		138	/**
		139	* Lookup will succeed only if the object is a regular file. If L_CREATE is
		140	* specified, an empty file will be created. This flag is mutually exclusive
		141	* with L_DIRECTORY.
		142	*/
		143	#define L_FILE 1
		144	/**
		145	* Lookup wil succeed only if the object is a directory. If L_CREATE is
		146	* specified, an empty directory will be created. This flag is mutually
		147	* exclusive with L_FILE.
		148	*/
		149	#define L_DIRECTORY 2
		150	/**
		151	* When used with L_CREATE, L_EXCLUSIVE will cause the lookup to fail if the
		152	* object already exists. L_EXCLUSIVE is implied when L_DIRECTORY is used.
		153	*/
		154	#define L_EXCLUSIVE 4
		155	/**
		156	* L_CREATE is used for creating both regular files and directories.
		157	*/
		158	#define L_CREATE 8
		159	/**
		160	* L_LINK is used for linking to an already existing nodes.
		161	*/
		162	#define L_LINK 16
		163	/**
		164	* L_UNLINK is used to remove leaves from the file system namespace. This flag
		165	* cannot be passed directly by the client, but will be set by VFS during
		166	* VFS_UNLINK.
		167	*/
		168	#define L_UNLINK 32
		169	/**
		170	* L_PARENT performs a lookup but returns the triplet of the parent node.
		171	* This flag may not be combined with any other lookup flag.
		172	*/
		173	#define L_PARENT 64
		174
		175	typedef enum vfs_node_type {
		176	VFS_NODE_UNKNOWN,
		177	VFS_NODE_FILE,
		178	VFS_NODE_DIRECTORY,
		179	} vfs_node_type_t;
		180
		181	typedef struct {
		182	vfs_triplet_t triplet;
		183	vfs_node_type_t type;
		184	size_t size;
		185	unsigned lnkcnt;
		186	} vfs_lookup_res_t;
		187
		188	/**
		189	* Instances of this type represent an active, in-memory VFS node and any state
		190	* which may be associated with it.
		191	*/
		192	typedef struct {
		193	VFS_TRIPLET; /*< Identity of the node. /
		194
		195	/**
		196	* Usage counter. This includes, but is not limited to, all vfs_file_t
		197	* structures that reference this node.
		198	*/
		199	unsigned refcnt;
		200
		201	/** Number of names this node has in the file system namespace. */
		202	unsigned lnkcnt;
		203
		204	link_t nh_link; /*< Node hash-table link. /
		205
		206	vfs_node_type_t type; /*< Partial info about the node type. /
		207
		208	size_t size; /*< Cached size if the node is a file. /
		209
		210	/**
		211	* Holding this rwlock prevents modifications of the node's contents.
		212	*/
		213	rwlock_t contents_rwlock;
		214	} vfs_node_t;
		215
		216	/**
		217	* Instances of this type represent an open file. If the file is opened by more
		218	* than one task, there will be a separate structure allocated for each task.
		219	*/
		220	typedef struct {
		221	/** Serializes access to this open file. */
		222	futex_t lock;
		223
		224	vfs_node_t *node;
		225
		226	/** Number of file handles referencing this file. */
		227	unsigned refcnt;
		228
		229	/** Append on write. */
		230	bool append;
		231
		232	/** Current position in the file. */
		233	off_t pos;
		234	} vfs_file_t;
		235
		236	extern futex_t nodes_futex;
		237
		238	extern link_t fs_head; /*< List of registered file systems. /
		239
		240	extern vfs_pair_t rootfs; /*< Root file system. /
		241
		242	#define MAX_PATH_LEN (64 * 1024)
		243
		244	#define PLB_SIZE (2 * MAX_PATH_LEN)
		245
		246	/** Each instance of this type describes one path lookup in progress. */
		247	typedef struct {
		248	link_t plb_link; /*< Active PLB entries list link. /
		249	unsigned index; /*< Index of the first character in PLB. /
		250	size_t len; /*< Number of characters in this PLB entry. /
		251	} plb_entry_t;
		252
		253	extern futex_t plb_futex; /*< Futex protecting plb and plb_head. /
		254	extern uint8_t plb; /< Path Lookup Buffer /
		255	extern link_t plb_head; /*< List of active PLB entries. /
		256
		257	/** Holding this rwlock prevents changes in file system namespace. */
		258	extern rwlock_t namespace_rwlock;
		259
		260	extern int vfs_grab_phone(fs_handle_t);
		261	extern void vfs_release_phone(int);
		262
		263	extern fs_handle_t fs_name_to_handle(char *, bool);
		264
		265	extern int vfs_lookup_internal(char , int, vfs_lookup_res_t , vfs_pair_t *,
		266	...);
		267
		268	extern bool vfs_nodes_init(void);
		269	extern vfs_node_t vfs_node_get(vfs_lookup_res_t );
		270	extern void vfs_node_put(vfs_node_t *);
		271
		272	#define MAX_OPEN_FILES 128
		273
		274	extern bool vfs_files_init(void);
		275	extern vfs_file_t *vfs_file_get(int);
		276	extern int vfs_fd_alloc(void);
		277	extern int vfs_fd_free(int);
		278
		279	extern void vfs_file_addref(vfs_file_t *);
		280	extern void vfs_file_delref(vfs_file_t *);
		281
		282	extern void vfs_node_addref(vfs_node_t *);
		283	extern void vfs_node_delref(vfs_node_t *);
		284
		285	extern void vfs_process_pending_mount(void);
		286	extern void vfs_register(ipc_callid_t, ipc_call_t *);
		287	extern void vfs_mount(ipc_callid_t, ipc_call_t *);
		288	extern void vfs_open(ipc_callid_t, ipc_call_t *);
		289	extern void vfs_close(ipc_callid_t, ipc_call_t *);
		290	extern void vfs_read(ipc_callid_t, ipc_call_t *);
		291	extern void vfs_write(ipc_callid_t, ipc_call_t *);
		292	extern void vfs_seek(ipc_callid_t, ipc_call_t *);
		293	extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
		294	extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
		295	extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
		296	extern void vfs_rename(ipc_callid_t, ipc_call_t *);
		297
		298	#endif
		299
		300	/**
		301	* @}
		302	*/

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