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/*

 * 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 <adt/list.h>

#include <fibril_sync.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;

	fibril_mutex_t phone_lock;

	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.

	 */

	fibril_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. */

	fibril_mutex_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 fibril_mutex_t nodes_mutex;

extern fibril_condvar_t fs_head_cv;

extern fibril_mutex_t fs_head_lock;

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 fibril_mutex_t plb_mutex;/**< Mutex 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 fibril_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_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_sync(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_fstat(ipc_callid_t, ipc_call_t *);

extern void vfs_fstat(ipc_callid_t, ipc_call_t *);

extern void vfs_stat(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

/**

 * @}

 */