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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* devfs (Device FileSystem) utilities.
2
3 Copyright (C) 1999-2002 Richard Gooch
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18
19 Richard Gooch may be reached by email at rgooch@atnf.csiro.au
20 The postal address is:
21 Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
22
23 ChangeLog
24
25 19991031 Richard Gooch <rgooch@atnf.csiro.au>
26 Created.
27 19991103 Richard Gooch <rgooch@atnf.csiro.au>
28 Created <_devfs_convert_name> and supported SCSI and IDE CD-ROMs
29 20000203 Richard Gooch <rgooch@atnf.csiro.au>
30 Changed operations pointer type to void *.
31 20000621 Richard Gooch <rgooch@atnf.csiro.au>
32 Changed interface to <devfs_register_series>.
33 20000622 Richard Gooch <rgooch@atnf.csiro.au>
34 Took account of interface change to <devfs_mk_symlink>.
35 Took account of interface change to <devfs_mk_dir>.
36 20010519 Richard Gooch <rgooch@atnf.csiro.au>
37 Documentation cleanup.
38 20010709 Richard Gooch <rgooch@atnf.csiro.au>
39 Created <devfs_*alloc_major> and <devfs_*alloc_devnum>.
40 20010710 Richard Gooch <rgooch@atnf.csiro.au>
41 Created <devfs_*alloc_unique_number>.
42 20010730 Richard Gooch <rgooch@atnf.csiro.au>
43 Documentation typo fix.
44 20010806 Richard Gooch <rgooch@atnf.csiro.au>
45 Made <block_semaphore> and <char_semaphore> private.
46 20010813 Richard Gooch <rgooch@atnf.csiro.au>
47 Fixed bug in <devfs_alloc_unique_number>: limited to 128 numbers
48 20010818 Richard Gooch <rgooch@atnf.csiro.au>
49 Updated major masks up to Linus' "no new majors" proclamation.
50 Block: were 126 now 122 free, char: were 26 now 19 free.
51 20020324 Richard Gooch <rgooch@atnf.csiro.au>
52 Fixed bug in <devfs_alloc_unique_number>: was clearing beyond
53 bitfield.
54 20020326 Richard Gooch <rgooch@atnf.csiro.au>
55 Fixed bitfield data type for <devfs_*alloc_devnum>.
56 Made major bitfield type and initialiser 64 bit safe.
57 20020413 Richard Gooch <rgooch@atnf.csiro.au>
58 Fixed shift warning on 64 bit machines.
59 20020428 Richard Gooch <rgooch@atnf.csiro.au>
60 Copied and used macro for error messages from fs/devfs/base.c
61 20021013 Richard Gooch <rgooch@atnf.csiro.au>
62 Documentation fix.
63 20030101 Adam J. Richter <adam@yggdrasil.com>
64 Eliminate DEVFS_SPECIAL_{CHR,BLK}. Use mode_t instead.
65 20030106 Christoph Hellwig <hch@infradead.org>
66 Rewrite devfs_{,de}alloc_devnum to look like C code.
67*/
68#include <linux/module.h>
69#include <linux/init.h>
70#include <linux/devfs_fs_kernel.h>
71#include <linux/slab.h>
72#include <linux/vmalloc.h>
73#include <linux/genhd.h>
74#include <linux/bitops.h>
75
76int devfs_register_tape(const char *name)
77{
78 char tname[32], dest[64];
79 static unsigned int tape_counter;
80 unsigned int n = tape_counter++;
81
82 sprintf(dest, "../%s", name);
83 sprintf(tname, "tapes/tape%u", n);
84 devfs_mk_symlink(tname, dest);
85
86 return n;
87}
88
89EXPORT_SYMBOL(devfs_register_tape);
90
91void devfs_unregister_tape(int num)
92{
93 if (num >= 0)
94 devfs_remove("tapes/tape%u", num);
95}
96
97EXPORT_SYMBOL(devfs_unregister_tape);