fs/devfs/util.c

   1 /*  devfs (Device FileSystem) utilities.
   2
   3     Copyright (C) 1999-2000  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 */
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39 #include <linux/locks.h>
  40 #include <linux/kdev_t.h>
  41 #include <linux/devfs_fs_kernel.h>
  42
  43
  44 /*  Private functions follow  */
  45
  46 /**
  47  *      _devfs_convert_name - Convert from an old style location-based name to new style.
  48  *      @new: The new name will be written here.
  49  *      @old: The old name.
  50  *      @disc: If true, disc partitioning information should be processed.
  51  */
  52
  53 static void __init _devfs_convert_name (char *new, const char *old, int disc)
  54 {
  55     int host, bus, target, lun;
  56     char *ptr;
  57     char part[8];
  58
  59     /*  Decode "c#b#t#u#"  */
  60     if (old[0] != 'c') return;
  61     host = simple_strtol (old + 1, &ptr, 10);
  62     if (ptr[0] != 'b') return;
  63     bus = simple_strtol (ptr + 1, &ptr, 10);
  64     if (ptr[0] != 't') return;
  65     target = simple_strtol (ptr + 1, &ptr, 10);
  66     if (ptr[0] != 'u') return;
  67     lun = simple_strtol (ptr + 1, &ptr, 10);
  68     if (disc)
  69     {
  70         /*  Decode "p#"  */
  71         if (ptr[0] == 'p') sprintf (part, "part%s", ptr + 1);
  72         else strcpy (part, "disc");
  73     }
  74     else part[0] = '\0';
  75     sprintf (new, "/host%d/bus%d/target%d/lun%d/%s",
  76              host, bus, target, lun, part);
  77 }   /*  End Function _devfs_convert_name  */
  78
  79
  80 /*  Public functions follow  */
  81
  82 /**
  83  *      devfs_make_root - Create the root FS device entry if required.
  84  *      @name: The name of the root FS device, as passed by "root=".
  85  */
  86
  87 void __init devfs_make_root (const char *name)
  88 {
  89     char dest[64];
  90
  91     if ( (strncmp (name, "sd/", 3) == 0) || (strncmp (name, "sr/", 3) == 0) )
  92     {
  93         strcpy (dest, "../scsi");
  94         _devfs_convert_name (dest + 7, name + 3, (name[1] == 'd') ? 1 : 0);
  95     }
  96     else if ( (strncmp (name, "ide/hd/", 7) == 0) ||
  97               (strncmp (name, "ide/cd/", 7) == 0) )
  98     {
  99         strcpy (dest, "..");
 100         _devfs_convert_name (dest + 2, name + 7, (name[4] == 'h') ? 1 : 0);
 101     }
 102     else return;
 103     devfs_mk_symlink (NULL, name, DEVFS_FL_DEFAULT, dest, NULL, NULL);
 104 }   /*  End Function devfs_make_root  */
 105
 106
 107 /**
 108  *      devfs_register_tape - Register a tape device in the "/dev/tapes" hierarchy.
 109  *      @de: Any tape device entry in the device directory.
 110  */
 111
 112 void devfs_register_tape (devfs_handle_t de)
 113 {
 114     int pos;
 115     devfs_handle_t parent, slave;
 116     char name[16], dest[64];
 117     static unsigned int tape_counter = 0;
 118     static devfs_handle_t tape_dir = NULL;
 119
 120     if (tape_dir == NULL) tape_dir = devfs_mk_dir (NULL, "tapes", NULL);
 121     parent = devfs_get_parent (de);
 122     pos = devfs_generate_path (parent, dest + 3, sizeof dest - 3);
 123     if (pos < 0) return;
 124     strncpy (dest + pos, "../", 3);
 125     sprintf (name, "tape%u", tape_counter++);
 126     devfs_mk_symlink (tape_dir, name, DEVFS_FL_DEFAULT, dest + pos,
 127                       &slave, NULL);
 128     devfs_auto_unregister (de, slave);
 129 }   /*  End Function devfs_register_tape  */
 130 EXPORT_SYMBOL(devfs_register_tape);
 131
 132
 133 /**
 134  *      devfs_register_series - Register a sequence of device entries.
 135  *      @dir: The handle to the parent devfs directory entry. If this is %NULL the
 136  *              new names are relative to the root of the devfs.
 137  *      @format: The printf-style format string. A single "\%u" is allowed.
 138  *      @flags: A set of bitwise-ORed flags (DEVFS_FL_*).
 139  *      @major: The major number. Not needed for regular files.
 140  *      @minor_start: The starting minor number. Not needed for regular files.
 141  *      @mode: The default file mode.
 142  *      @ops: The &file_operations or &block_device_operations structure.
 143  *              This must not be externally deallocated.
 144  *      @info: An arbitrary pointer which will be written to the private_data
 145  *              field of the &file structure passed to the device driver. You can set
 146  *              this to whatever you like, and change it once the file is opened (the next
 147  *              file opened will not see this change).
 148  */
 149
 150 void devfs_register_series (devfs_handle_t dir, const char *format,
 151                             unsigned int num_entries, unsigned int flags,
 152                             unsigned int major, unsigned int minor_start,
 153                             umode_t mode, void *ops, void *info)
 154 {
 155     unsigned int count;
 156     char devname[128];
 157
 158     for (count = 0; count < num_entries; ++count)
 159     {
 160         sprintf (devname, format, count);
 161         devfs_register (dir, devname, flags, major, minor_start + count,
 162                         mode, ops, info);
 163     }
 164 }   /*  End Function devfs_register_series  */
 165 EXPORT_SYMBOL(devfs_register_series);