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  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 <devmap.h>
  42. #include <bool.h>
  43. #include <ipc/vfs.h>
  44.  
  45. // FIXME: according to CONFIG_DEBUG
  46. // #define dprintf(...)  printf(__VA_ARGS__)
  47.  
  48. #define dprintf(...)
  49.  
  50. /**
  51.  * A structure like this will be allocated for each registered file system.
  52.  */
  53. typedef struct {
  54.     link_t fs_link;
  55.     vfs_info_t vfs_info;
  56.     fs_handle_t fs_handle;
  57.     futex_t phone_futex;    /**< Phone serializing futex. */
  58.     ipcarg_t phone;
  59. } fs_info_t;
  60.  
  61. /**
  62.  * VFS_PAIR uniquely represents a file system instance.
  63.  */
  64. #define VFS_PAIR \
  65.     fs_handle_t fs_handle; \
  66.     dev_handle_t dev_handle;
  67.  
  68. /**
  69.  * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
  70.  * doesn't contain any state. For a stateful structure, see vfs_node_t.
  71.  *
  72.  * @note    fs_handle, dev_handle and index are meant to be returned in one
  73.  *      IPC reply.
  74.  */
  75. #define VFS_TRIPLET \
  76.     VFS_PAIR; \
  77.     fs_index_t index;
  78.  
  79. typedef struct {
  80.     VFS_PAIR;
  81. } vfs_pair_t;
  82.  
  83. typedef struct {
  84.     VFS_TRIPLET;
  85. } vfs_triplet_t;
  86.  
  87. typedef enum vfs_node_type {
  88.     VFS_NODE_UNKNOWN,
  89.     VFS_NODE_FILE,
  90.     VFS_NODE_DIRECTORY,
  91. } vfs_node_type_t;
  92.  
  93. typedef struct {
  94.     vfs_triplet_t triplet;
  95.     vfs_node_type_t type;
  96.     size_t size;
  97.     unsigned lnkcnt;
  98. } vfs_lookup_res_t;
  99.  
  100. /**
  101.  * Instances of this type represent an active, in-memory VFS node and any state
  102.  * which may be associated with it.
  103.  */
  104. typedef struct {
  105.     VFS_TRIPLET;        /**< Identity of the node. */
  106.  
  107.     /**
  108.      * Usage counter.  This includes, but is not limited to, all vfs_file_t
  109.      * structures that reference this node.
  110.      */
  111.     unsigned refcnt;
  112.    
  113.     /** Number of names this node has in the file system namespace. */
  114.     unsigned lnkcnt;
  115.  
  116.     link_t nh_link;     /**< Node hash-table link. */
  117.  
  118.     vfs_node_type_t type;   /**< Partial info about the node type. */
  119.  
  120.     size_t size;        /**< Cached size if the node is a file. */
  121.  
  122.     /**
  123.      * Holding this rwlock prevents modifications of the node's contents.
  124.      */
  125.     rwlock_t contents_rwlock;
  126. } vfs_node_t;
  127.  
  128. /**
  129.  * Instances of this type represent an open file. If the file is opened by more
  130.  * than one task, there will be a separate structure allocated for each task.
  131.  */
  132. typedef struct {
  133.     /** Serializes access to this open file. */
  134.     futex_t lock;
  135.  
  136.     vfs_node_t *node;
  137.    
  138.     /** Number of file handles referencing this file. */
  139.     unsigned refcnt;
  140.  
  141.     /** Append on write. */
  142.     bool append;
  143.  
  144.     /** Current position in the file. */
  145.     off_t pos;
  146. } vfs_file_t;
  147.  
  148. extern futex_t nodes_futex;
  149.  
  150. extern link_t fs_head;      /**< List of registered file systems. */
  151.  
  152. extern vfs_pair_t rootfs;   /**< Root file system. */
  153.  
  154. /** Each instance of this type describes one path lookup in progress. */
  155. typedef struct {
  156.     link_t  plb_link;   /**< Active PLB entries list link. */
  157.     unsigned index;     /**< Index of the first character in PLB. */
  158.     size_t len;     /**< Number of characters in this PLB entry. */
  159. } plb_entry_t;
  160.  
  161. extern futex_t plb_futex;   /**< Futex protecting plb and plb_head. */
  162. extern uint8_t *plb;        /**< Path Lookup Buffer */
  163. extern link_t plb_head;     /**< List of active PLB entries. */
  164.  
  165. #define MAX_MNTOPTS_LEN     256
  166.  
  167. /** Holding this rwlock prevents changes in file system namespace. */
  168. extern rwlock_t namespace_rwlock;
  169.  
  170. extern int vfs_grab_phone(fs_handle_t);
  171. extern void vfs_release_phone(int);
  172.  
  173. extern fs_handle_t fs_name_to_handle(char *, bool);
  174.  
  175. extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *,
  176.     vfs_pair_t *, ...);
  177. extern int vfs_open_node_internal(vfs_lookup_res_t *);
  178.  
  179. extern bool vfs_nodes_init(void);
  180. extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *);
  181. extern void vfs_node_put(vfs_node_t *);
  182.  
  183. #define MAX_OPEN_FILES  128
  184.  
  185. extern bool vfs_files_init(void);
  186. extern vfs_file_t *vfs_file_get(int);
  187. extern int vfs_fd_alloc(void);
  188. extern int vfs_fd_free(int);
  189.  
  190. extern void vfs_file_addref(vfs_file_t *);
  191. extern void vfs_file_delref(vfs_file_t *);
  192.  
  193. extern void vfs_node_addref(vfs_node_t *);
  194. extern void vfs_node_delref(vfs_node_t *);
  195.  
  196. extern void vfs_process_pending_mount(void);
  197. extern void vfs_register(ipc_callid_t, ipc_call_t *);
  198. extern void vfs_mount(ipc_callid_t, ipc_call_t *);
  199. extern void vfs_open(ipc_callid_t, ipc_call_t *);
  200. extern void vfs_open_node(ipc_callid_t, ipc_call_t *);
  201. extern void vfs_device(ipc_callid_t, ipc_call_t *);
  202. extern void vfs_sync(ipc_callid_t, ipc_call_t *);
  203. extern void vfs_node(ipc_callid_t, ipc_call_t *);
  204. extern void vfs_close(ipc_callid_t, ipc_call_t *);
  205. extern void vfs_read(ipc_callid_t, ipc_call_t *);
  206. extern void vfs_write(ipc_callid_t, ipc_call_t *);
  207. extern void vfs_seek(ipc_callid_t, ipc_call_t *);
  208. extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
  209. extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
  210. extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
  211. extern void vfs_rename(ipc_callid_t, ipc_call_t *);
  212.  
  213. #endif
  214.  
  215. /**
  216.  * @}
  217.  */
  218.