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