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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 <bool.h>
  42.  
  43. #define dprintf(...)    printf(__VA_ARGS__)
  44.  
  45. #define VFS_FIRST   IPC_FIRST_USER_METHOD
  46.  
  47. #define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST)  
  48.  
  49. /* Basic types. */
  50. typedef int16_t fs_handle_t;
  51. typedef int16_t dev_handle_t;
  52. typedef uint32_t fs_index_t;
  53.  
  54. typedef enum {
  55.     VFS_READ = VFS_FIRST,
  56.     VFS_WRITE,
  57.     VFS_TRUNCATE,
  58.     VFS_MOUNT,
  59.     VFS_UNMOUNT,
  60.     VFS_LAST_CMN,   /* keep this the last member of this enum */
  61. } vfs_request_cmn_t;
  62.  
  63. typedef enum {
  64.     VFS_LOOKUP = VFS_LAST_CMN,
  65.     VFS_DESTROY,
  66.     VFS_LAST_CLNT,  /* keep this the last member of this enum */
  67. } vfs_request_clnt_t;
  68.  
  69. typedef enum {
  70.     VFS_REGISTER = VFS_LAST_CMN,
  71.     VFS_OPEN,
  72.     VFS_CLOSE,
  73.     VFS_SEEK,
  74.     VFS_MKDIR,
  75.     VFS_UNLINK,
  76.     VFS_RENAME,
  77.     VFS_LAST_SRV,   /* keep this the last member of this enum */
  78. } vfs_request_srv_t;
  79.  
  80.  
  81. /**
  82.  * An instance of this structure is associated with a particular FS operation.
  83.  * It tells VFS if the FS supports the operation or maybe if a default one
  84.  * should be used.
  85.  */
  86. typedef enum {
  87.     VFS_OP_NULL = 0,
  88.     VFS_OP_DEFAULT,
  89.     VFS_OP_DEFINED
  90. } vfs_op_t;
  91.  
  92. #define FS_NAME_MAXLEN  20
  93.  
  94. /**
  95.  * A structure like this is passed to VFS by each individual FS upon its
  96.  * registration. It assosiates a human-readable identifier with each
  97.  * registered FS. More importantly, through this structure, the FS announces
  98.  * what operations it supports.
  99.  */
  100. typedef struct {
  101.     /** Unique identifier of the fs. */
  102.     char name[FS_NAME_MAXLEN + 1];
  103.    
  104.     /** Operations. */
  105.     vfs_op_t ops[VFS_LAST_CLNT - VFS_FIRST];
  106. } vfs_info_t;
  107.  
  108. /**
  109.  * A structure like this will be allocated for each registered file system.
  110.  */
  111. typedef struct {
  112.     link_t fs_link;
  113.     vfs_info_t vfs_info;
  114.     fs_handle_t fs_handle;
  115.     futex_t phone_futex;    /**< Phone serializing futex. */
  116.     ipcarg_t phone;
  117. } fs_info_t;
  118.  
  119. /**
  120.  * VFS_PAIR uniquely represents a file system instance.
  121.  */
  122. #define VFS_PAIR        \
  123.     fs_handle_t fs_handle;  \
  124.     dev_handle_t dev_handle;
  125.  
  126. /**
  127.  * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
  128.  * doesn't contain any state. For a stateful structure, see vfs_node_t.
  129.  *
  130.  * @note    fs_handle, dev_handle and index are meant to be returned in one
  131.  *      IPC reply.
  132.  */
  133. #define VFS_TRIPLET \
  134.     VFS_PAIR;   \
  135.     fs_index_t index;
  136.  
  137. typedef struct {
  138.     VFS_PAIR;
  139. } vfs_pair_t;
  140.  
  141. typedef struct {
  142.     VFS_TRIPLET;
  143. } vfs_triplet_t;
  144.  
  145. /*
  146.  * Lookup flags.
  147.  */
  148. /**
  149.  * No lookup flags used.
  150.  */
  151. #define L_NONE      0
  152. /**
  153.  * Lookup will succeed only if the object is a regular file.  If L_CREATE is
  154.  * specified, an empty file will be created. This flag is mutually exclusive
  155.  * with L_DIRECTORY.
  156.  */
  157. #define L_FILE      1
  158. /**
  159.  * Lookup wil succeed only if the object is a directory. If L_CREATE is
  160.  * specified, an empty directory will be created. This flag is mutually
  161.  * exclusive with L_FILE.
  162.  */
  163. #define L_DIRECTORY 2
  164. /**
  165.  * When used with L_CREATE, L_EXCLUSIVE will cause the lookup to fail if the
  166.  * object already exists. L_EXCLUSIVE is implied when L_DIRECTORY is used.
  167.  */
  168. #define L_EXCLUSIVE 4
  169. /**
  170.  * L_CREATE is used for creating both regular files and directories.
  171.  */
  172. #define L_CREATE    8
  173. /**
  174.  * L_LINK is used for linking to an already existing nodes.
  175.  */
  176. #define L_LINK      16
  177. /**
  178.  * L_UNLINK is used to remove leaves from the file system namespace. This flag
  179.  * cannot be passed directly by the client, but will be set by VFS during
  180.  * VFS_UNLINK.
  181.  */
  182. #define L_UNLINK    32 
  183. /**
  184.  * L_PARENT performs a lookup but returns the triplet of the parent node.
  185.  * This flag may not be combined with any other lookup flag.
  186.  */
  187. #define L_PARENT    64 
  188.  
  189. typedef struct {
  190.     vfs_triplet_t triplet;
  191.     size_t size;
  192.     unsigned lnkcnt;
  193. } vfs_lookup_res_t;
  194.  
  195. /**
  196.  * Instances of this type represent an active, in-memory VFS node and any state
  197.  * which may be associated with it.
  198.  */
  199. typedef struct {
  200.     VFS_TRIPLET;        /**< Identity of the node. */
  201.  
  202.     /**
  203.      * Usage counter.  This includes, but is not limited to, all vfs_file_t
  204.      * structures that reference this node.
  205.      */
  206.     unsigned refcnt;
  207.    
  208.     /** Number of names this node has in the file system namespace. */
  209.     unsigned lnkcnt;
  210.  
  211.     link_t nh_link;     /**< Node hash-table link. */
  212.     size_t size;        /**< Cached size if the node is a file. */
  213.  
  214.     /**
  215.      * Holding this rwlock prevents modifications of the node's contents.
  216.      */
  217.     rwlock_t contents_rwlock;
  218. } vfs_node_t;
  219.  
  220. /**
  221.  * Instances of this type represent an open file. If the file is opened by more
  222.  * than one task, there will be a separate structure allocated for each task.
  223.  */
  224. typedef struct {
  225.     /** Serializes access to this open file. */
  226.     futex_t lock;
  227.  
  228.     vfs_node_t *node;
  229.    
  230.     /** Number of file handles referencing this file. */
  231.     unsigned refcnt;
  232.  
  233.     /** Append on write. */
  234.     bool append;
  235.  
  236.     /** Current position in the file. */
  237.     off_t pos;
  238. } vfs_file_t;
  239.  
  240. extern futex_t nodes_futex;
  241.  
  242. extern link_t fs_head;      /**< List of registered file systems. */
  243.  
  244. extern vfs_triplet_t rootfs;    /**< Root node of the root file system. */
  245.  
  246. #define MAX_PATH_LEN        (64 * 1024)
  247.  
  248. #define PLB_SIZE        (2 * MAX_PATH_LEN)
  249.  
  250. /** Each instance of this type describes one path lookup in progress. */
  251. typedef struct {
  252.     link_t  plb_link;   /**< Active PLB entries list link. */
  253.     unsigned index;     /**< Index of the first character in PLB. */
  254.     size_t len;     /**< Number of characters in this PLB entry. */
  255. } plb_entry_t;
  256.  
  257. extern futex_t plb_futex;   /**< Futex protecting plb and plb_head. */
  258. extern uint8_t *plb;        /**< Path Lookup Buffer */
  259. extern link_t plb_head;     /**< List of active PLB entries. */
  260.  
  261. /** Holding this rwlock prevents changes in file system namespace. */
  262. extern rwlock_t namespace_rwlock;
  263.  
  264. extern int vfs_grab_phone(fs_handle_t);
  265. extern void vfs_release_phone(int);
  266.  
  267. extern fs_handle_t fs_name_to_handle(char *, bool);
  268.  
  269. extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *, vfs_pair_t *,
  270.     ...);
  271.  
  272. extern bool vfs_nodes_init(void);
  273. extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *);
  274. extern void vfs_node_put(vfs_node_t *);
  275.  
  276. #define MAX_OPEN_FILES  128
  277.  
  278. extern bool vfs_files_init(void);
  279. extern vfs_file_t *vfs_file_get(int);
  280. extern int vfs_fd_alloc(void);
  281. extern void vfs_fd_free(int);
  282.  
  283. extern void vfs_file_addref(vfs_file_t *);
  284. extern void vfs_file_delref(vfs_file_t *);
  285.  
  286. extern void vfs_node_addref(vfs_node_t *);
  287. extern void vfs_node_delref(vfs_node_t *);
  288.  
  289. extern void vfs_register(ipc_callid_t, ipc_call_t *);
  290. extern void vfs_mount(ipc_callid_t, ipc_call_t *);
  291. extern void vfs_open(ipc_callid_t, ipc_call_t *);
  292. extern void vfs_close(ipc_callid_t, ipc_call_t *);
  293. extern void vfs_read(ipc_callid_t, ipc_call_t *);
  294. extern void vfs_write(ipc_callid_t, ipc_call_t *);
  295. extern void vfs_seek(ipc_callid_t, ipc_call_t *);
  296. extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
  297. extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
  298. extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
  299. extern void vfs_rename(ipc_callid_t, ipc_call_t *);
  300.  
  301. #endif
  302.  
  303. /**
  304.  * @}
  305.  */
  306.