/*
* Copyright (c) 2008 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup fs
* @{
*/
#ifndef VFS_VFS_H_
#define VFS_VFS_H_
#include <ipc/ipc.h>
#include <libadt/list.h>
#include <futex.h>
#include <rwlock.h>
#include <sys/types.h>
#include <devmap.h>
#include <bool.h>
#include <ipc/vfs.h>
// FIXME: according to CONFIG_DEBUG
// #define dprintf(...) printf(__VA_ARGS__)
#define dprintf(...)
/**
* A structure like this will be allocated for each registered file system.
*/
typedef struct {
link_t fs_link;
vfs_info_t vfs_info;
fs_handle_t fs_handle;
futex_t phone_futex; /**< Phone serializing futex. */
ipcarg_t phone;
} fs_info_t;
/**
* VFS_PAIR uniquely represents a file system instance.
*/
#define VFS_PAIR \
fs_handle_t fs_handle; \
dev_handle_t dev_handle;
/**
* VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
* doesn't contain any state. For a stateful structure, see vfs_node_t.
*
* @note fs_handle, dev_handle and index are meant to be returned in one
* IPC reply.
*/
#define VFS_TRIPLET \
VFS_PAIR; \
fs_index_t index;
typedef struct {
VFS_PAIR;
} vfs_pair_t;
typedef struct {
VFS_TRIPLET;
} vfs_triplet_t;
typedef enum vfs_node_type {
VFS_NODE_UNKNOWN,
VFS_NODE_FILE,
VFS_NODE_DIRECTORY,
} vfs_node_type_t;
typedef struct {
vfs_triplet_t triplet;
vfs_node_type_t type;
size_t size;
unsigned lnkcnt;
} vfs_lookup_res_t;
/**
* Instances of this type represent an active, in-memory VFS node and any state
* which may be associated with it.
*/
typedef struct {
VFS_TRIPLET; /**< Identity of the node. */
/**
* Usage counter. This includes, but is not limited to, all vfs_file_t
* structures that reference this node.
*/
unsigned refcnt;
/** Number of names this node has in the file system namespace. */
unsigned lnkcnt;
link_t nh_link; /**< Node hash-table link. */
vfs_node_type_t type; /**< Partial info about the node type. */
size_t size; /**< Cached size if the node is a file. */
/**
* Holding this rwlock prevents modifications of the node's contents.
*/
rwlock_t contents_rwlock;
} vfs_node_t;
/**
* Instances of this type represent an open file. If the file is opened by more
* than one task, there will be a separate structure allocated for each task.
*/
typedef struct {
/** Serializes access to this open file. */
futex_t lock;
vfs_node_t *node;
/** Number of file handles referencing this file. */
unsigned refcnt;
/** Append on write. */
bool append;
/** Current position in the file. */
off_t pos;
} vfs_file_t;
extern futex_t nodes_futex;
extern link_t fs_head; /**< List of registered file systems. */
extern vfs_pair_t rootfs; /**< Root file system. */
/** Each instance of this type describes one path lookup in progress. */
typedef struct {
link_t plb_link; /**< Active PLB entries list link. */
unsigned index; /**< Index of the first character in PLB. */
size_t len; /**< Number of characters in this PLB entry. */
} plb_entry_t;
extern futex_t plb_futex; /**< Futex protecting plb and plb_head. */
extern uint8_t *plb; /**< Path Lookup Buffer */
extern link_t plb_head; /**< List of active PLB entries. */
#define MAX_MNTOPTS_LEN 256
/** Holding this rwlock prevents changes in file system namespace. */
extern rwlock_t namespace_rwlock;
extern int vfs_grab_phone(fs_handle_t);
extern void vfs_release_phone(int);
extern fs_handle_t fs_name_to_handle(char *, bool);
extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *,
vfs_pair_t *, ...);
extern int vfs_open_node_internal(vfs_lookup_res_t *);
extern bool vfs_nodes_init(void);
extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *);
extern void vfs_node_put(vfs_node_t *);
#define MAX_OPEN_FILES 128
extern bool vfs_files_init(void);
extern vfs_file_t *vfs_file_get(int);
extern int vfs_fd_alloc(void);
extern int vfs_fd_free(int);
extern void vfs_file_addref(vfs_file_t *);
extern void vfs_file_delref(vfs_file_t *);
extern void vfs_node_addref(vfs_node_t *);
extern void vfs_node_delref(vfs_node_t *);
extern void vfs_process_pending_mount(void);
extern void vfs_register(ipc_callid_t, ipc_call_t *);
extern void vfs_mount(ipc_callid_t, ipc_call_t *);
extern void vfs_open(ipc_callid_t, ipc_call_t *);
extern void vfs_open_node(ipc_callid_t, ipc_call_t *);
extern void vfs_device(ipc_callid_t, ipc_call_t *);
extern void vfs_sync(ipc_callid_t, ipc_call_t *);
extern void vfs_node(ipc_callid_t, ipc_call_t *);
extern void vfs_close(ipc_callid_t, ipc_call_t *);
extern void vfs_read(ipc_callid_t, ipc_call_t *);
extern void vfs_write(ipc_callid_t, ipc_call_t *);
extern void vfs_seek(ipc_callid_t, ipc_call_t *);
extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
extern void vfs_rename(ipc_callid_t, ipc_call_t *);
#endif
/**
* @}
*/