source: mainline/uspace/srv/fs/tmpfs/tmpfs.h@ 69a60c4

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 69a60c4 was ed903174, checked in by Martin Decky <martin@…>, 15 years ago

implement support for 64bit file offsets

  • the libc API is a small deviation from standard, but we have no reason to keep a strict backward compatibility with ancient code so far
    • the basic signed 64bit offset type is called off64_t
      • lseek() and fseek() take off64_t arguments (since the argument represents a relative offset)
      • ftell() returns off64_t values (since it is a wrapper of lseek())
      • vfs_seek() implementation supports negative offsets when SEEK_CUR and SEEK_END is used
    • aoff64_t is used for internal unsigned representation of sizes (in bytes, blocks, etc.) and absolute offsets
      • mmap() and ftruncate() take aoff64_t arguments (since the full range of the absolute file offset should be used here)
      • struct stat stores the file size as aoff64_t
    • in both cases the explicit range of the types shown in the names is helpful for proper filesystem and IPC interaction
    • note: size_t should be used only for representing in-memory sizes and offsets, not device and file-related information, and vice versa
      • the code base still needs a thorough revision with respect to this rule
    • PRIdOFF64 and PRIuOFF64 can be used for printing the offsets
  • VFS_OUT_LOOKUP returns the 64bit file size in two IPC arguments
    • since all 5 IPC arguments have already been taken, the fs_handle is returned as the return value (fs_handle has only 16 bits, thus the return value can be used for both indicating errors as negative values and returning positive handles)
  • VFS_OUT_READ and VFS_OUT_WRITE use aoff64_t absolute offsets split into two IPC arguments

replace bn_t with aoff64_t as a generic 64bit bytes/block counter type

note: filesystem drivers need to be revised with respect to make sure that all out-of-range checks are correct (especially w.r.t. file and block offsets)
  • Property mode set to 100644
File size: 3.4 KB
Line 
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 TMPFS_TMPFS_H_
34#define TMPFS_TMPFS_H_
35
36#include <ipc/ipc.h>
37#include <libfs.h>
38#include <atomic.h>
39#include <sys/types.h>
40#include <bool.h>
41#include <adt/hash_table.h>
42
43#define TMPFS_NODE(node) ((node) ? (tmpfs_node_t *)(node)->data : NULL)
44#define FS_NODE(node) ((node) ? (node)->bp : NULL)
45
46typedef enum {
47 TMPFS_NONE,
48 TMPFS_FILE,
49 TMPFS_DIRECTORY
50} tmpfs_dentry_type_t;
51
52/* forward declaration */
53struct tmpfs_node;
54
55typedef struct tmpfs_dentry {
56 link_t link; /**< Linkage for the list of siblings. */
57 struct tmpfs_node *node;/**< Back pointer to TMPFS node. */
58 char *name; /**< Name of dentry. */
59} tmpfs_dentry_t;
60
61typedef struct tmpfs_node {
62 fs_node_t *bp; /**< Back pointer to the FS node. */
63 fs_index_t index; /**< TMPFS node index. */
64 dev_handle_t dev_handle;/**< Device handle. */
65 link_t nh_link; /**< Nodes hash table link. */
66 tmpfs_dentry_type_t type;
67 unsigned lnkcnt; /**< Link count. */
68 size_t size; /**< File size if type is TMPFS_FILE. */
69 void *data; /**< File content's if type is TMPFS_FILE. */
70 link_t cs_head; /**< Head of child's siblings list. */
71} tmpfs_node_t;
72
73extern fs_reg_t tmpfs_reg;
74
75extern libfs_ops_t tmpfs_libfs_ops;
76
77extern bool tmpfs_init(void);
78
79extern void tmpfs_mounted(ipc_callid_t, ipc_call_t *);
80extern void tmpfs_mount(ipc_callid_t, ipc_call_t *);
81extern void tmpfs_unmounted(ipc_callid_t, ipc_call_t *);
82extern void tmpfs_unmount(ipc_callid_t, ipc_call_t *);
83extern void tmpfs_lookup(ipc_callid_t, ipc_call_t *);
84extern void tmpfs_read(ipc_callid_t, ipc_call_t *);
85extern void tmpfs_write(ipc_callid_t, ipc_call_t *);
86extern void tmpfs_truncate(ipc_callid_t, ipc_call_t *);
87extern void tmpfs_stat(ipc_callid_t, ipc_call_t *);
88extern void tmpfs_close(ipc_callid_t, ipc_call_t *);
89extern void tmpfs_destroy(ipc_callid_t, ipc_call_t *);
90extern void tmpfs_open_node(ipc_callid_t, ipc_call_t *);
91extern void tmpfs_sync(ipc_callid_t, ipc_call_t *);
92
93extern bool tmpfs_restore(dev_handle_t);
94
95#endif
96
97/**
98 * @}
99 */
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