1 |
1275 |
phoenix |
/*
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2 |
|
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* linux/fs/fat/misc.c
|
3 |
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*
|
4 |
|
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* Written 1992,1993 by Werner Almesberger
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5 |
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* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
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6 |
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* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
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7 |
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*/
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8 |
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9 |
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#include <linux/fs.h>
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10 |
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#include <linux/msdos_fs.h>
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11 |
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#include <linux/sched.h>
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12 |
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#include <linux/kernel.h>
|
13 |
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#include <linux/errno.h>
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14 |
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#include <linux/string.h>
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15 |
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#include <linux/stat.h>
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16 |
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17 |
|
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#if 0
|
18 |
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# define PRINTK(x) printk x
|
19 |
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#else
|
20 |
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# define PRINTK(x)
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21 |
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#endif
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22 |
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#define Printk(x) printk x
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23 |
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|
24 |
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/* Well-known binary file extensions - of course there are many more */
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25 |
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26 |
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static char ascii_extensions[] =
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27 |
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"TXT" "ME " "HTM" "1ST" "LOG" " " /* text files */
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28 |
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"C " "H " "CPP" "LIS" "PAS" "FOR" /* programming languages */
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29 |
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"F " "MAK" "INC" "BAS" /* programming languages */
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30 |
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"BAT" "SH " /* program code :) */
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31 |
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"INI" /* config files */
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32 |
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"PBM" "PGM" "DXF" /* graphics */
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33 |
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"TEX"; /* TeX */
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34 |
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35 |
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36 |
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/*
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37 |
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* fat_fs_panic reports a severe file system problem and sets the file system
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38 |
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* read-only. The file system can be made writable again by remounting it.
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39 |
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*/
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40 |
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41 |
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void fat_fs_panic(struct super_block *s,const char *msg)
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42 |
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{
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43 |
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int not_ro;
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44 |
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45 |
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not_ro = !(s->s_flags & MS_RDONLY);
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46 |
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if (not_ro) s->s_flags |= MS_RDONLY;
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47 |
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printk("Filesystem panic (dev %s).\n %s\n", kdevname(s->s_dev), msg);
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48 |
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if (not_ro)
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49 |
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printk(" File system has been set read-only\n");
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50 |
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}
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51 |
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52 |
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53 |
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/*
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54 |
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* fat_is_binary selects optional text conversion based on the conversion mode
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55 |
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* and the extension part of the file name.
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56 |
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*/
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57 |
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58 |
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int fat_is_binary(char conversion,char *extension)
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59 |
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{
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60 |
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char *walk;
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61 |
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62 |
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switch (conversion) {
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63 |
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case 'b':
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64 |
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return 1;
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65 |
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case 't':
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66 |
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return 0;
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67 |
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case 'a':
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68 |
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for (walk = ascii_extensions; *walk; walk += 3)
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69 |
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if (!strncmp(extension,walk,3)) return 0;
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70 |
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return 1; /* default binary conversion */
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71 |
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default:
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72 |
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printk("Invalid conversion mode - defaulting to "
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73 |
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"binary.\n");
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74 |
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return 1;
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75 |
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}
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76 |
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}
|
77 |
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|
78 |
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void lock_fat(struct super_block *sb)
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79 |
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{
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80 |
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down(&(MSDOS_SB(sb)->fat_lock));
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81 |
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}
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82 |
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83 |
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void unlock_fat(struct super_block *sb)
|
84 |
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{
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85 |
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up(&(MSDOS_SB(sb)->fat_lock));
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86 |
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}
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87 |
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|
88 |
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/* Flushes the number of free clusters on FAT32 */
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89 |
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/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
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90 |
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void fat_clusters_flush(struct super_block *sb)
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91 |
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{
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92 |
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struct buffer_head *bh;
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93 |
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struct fat_boot_fsinfo *fsinfo;
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94 |
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95 |
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bh = fat_bread(sb, MSDOS_SB(sb)->fsinfo_sector);
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96 |
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if (bh == NULL) {
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97 |
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printk("FAT bread failed in fat_clusters_flush\n");
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98 |
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return;
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99 |
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}
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100 |
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101 |
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fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
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102 |
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/* Sanity check */
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103 |
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if (!IS_FSINFO(fsinfo)) {
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104 |
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printk("FAT: Did not find valid FSINFO signature.\n"
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105 |
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"Found signature1 0x%x signature2 0x%x sector=%ld.\n",
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106 |
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CF_LE_L(fsinfo->signature1), CF_LE_L(fsinfo->signature2),
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107 |
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MSDOS_SB(sb)->fsinfo_sector);
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108 |
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return;
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109 |
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}
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110 |
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fsinfo->free_clusters = CF_LE_L(MSDOS_SB(sb)->free_clusters);
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111 |
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fsinfo->next_cluster = CF_LE_L(MSDOS_SB(sb)->prev_free);
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112 |
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fat_mark_buffer_dirty(sb, bh);
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113 |
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fat_brelse(sb, bh);
|
114 |
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}
|
115 |
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|
116 |
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/*
|
117 |
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* fat_add_cluster tries to allocate a new cluster and adds it to the
|
118 |
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* file represented by inode.
|
119 |
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*/
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120 |
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int fat_add_cluster(struct inode *inode)
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121 |
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{
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122 |
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struct super_block *sb = inode->i_sb;
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123 |
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int count, nr, limit, last, curr, file_cluster;
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124 |
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int cluster_size = MSDOS_SB(sb)->cluster_size;
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125 |
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int res = -ENOSPC;
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126 |
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127 |
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lock_fat(sb);
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128 |
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129 |
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if (MSDOS_SB(sb)->free_clusters == 0) {
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130 |
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unlock_fat(sb);
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131 |
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return res;
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132 |
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}
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133 |
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limit = MSDOS_SB(sb)->clusters;
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134 |
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nr = limit; /* to keep GCC happy */
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135 |
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for (count = 0; count < limit; count++) {
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136 |
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nr = ((count + MSDOS_SB(sb)->prev_free) % limit) + 2;
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137 |
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if (fat_access(sb, nr, -1) == 0)
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138 |
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break;
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139 |
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}
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140 |
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if (count >= limit) {
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141 |
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MSDOS_SB(sb)->free_clusters = 0;
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142 |
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unlock_fat(sb);
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143 |
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return res;
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144 |
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}
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145 |
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146 |
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MSDOS_SB(sb)->prev_free = (count + MSDOS_SB(sb)->prev_free + 1) % limit;
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147 |
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fat_access(sb, nr, EOF_FAT(sb));
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148 |
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if (MSDOS_SB(sb)->free_clusters != -1)
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149 |
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MSDOS_SB(sb)->free_clusters--;
|
150 |
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if (MSDOS_SB(sb)->fat_bits == 32)
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151 |
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fat_clusters_flush(sb);
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152 |
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|
153 |
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unlock_fat(sb);
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154 |
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|
155 |
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/* We must locate the last cluster of the file to add this
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156 |
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new one (nr) to the end of the link list (the FAT).
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157 |
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|
158 |
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Here file_cluster will be the number of the last cluster of the
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159 |
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file (before we add nr).
|
160 |
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|
161 |
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last is the corresponding cluster number on the disk. We will
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162 |
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use last to plug the nr cluster. We will use file_cluster to
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163 |
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update the cache.
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164 |
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*/
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165 |
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last = file_cluster = 0;
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166 |
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if ((curr = MSDOS_I(inode)->i_start) != 0) {
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167 |
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fat_cache_lookup(inode, INT_MAX, &last, &curr);
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168 |
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file_cluster = last;
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169 |
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while (curr && curr != -1){
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170 |
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file_cluster++;
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171 |
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if (!(curr = fat_access(sb, last = curr,-1))) {
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172 |
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fat_fs_panic(sb, "File without EOF");
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173 |
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return res;
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174 |
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}
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175 |
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}
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176 |
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}
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177 |
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if (last) {
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178 |
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fat_access(sb, last, nr);
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179 |
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fat_cache_add(inode, file_cluster, nr);
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180 |
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} else {
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181 |
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MSDOS_I(inode)->i_start = nr;
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182 |
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MSDOS_I(inode)->i_logstart = nr;
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183 |
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mark_inode_dirty(inode);
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184 |
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}
|
185 |
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if (file_cluster
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186 |
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!= inode->i_blocks / cluster_size / (sb->s_blocksize / 512)) {
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187 |
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printk ("file_cluster badly computed!!! %d <> %ld\n",
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188 |
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file_cluster,
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189 |
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inode->i_blocks / cluster_size / (sb->s_blocksize / 512));
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190 |
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fat_cache_inval_inode(inode);
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191 |
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}
|
192 |
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inode->i_blocks += (1 << MSDOS_SB(sb)->cluster_bits) / 512;
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193 |
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|
194 |
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return nr;
|
195 |
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}
|
196 |
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|
197 |
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struct buffer_head *fat_extend_dir(struct inode *inode)
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198 |
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{
|
199 |
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struct super_block *sb = inode->i_sb;
|
200 |
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int nr, sector, last_sector;
|
201 |
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struct buffer_head *bh, *res = NULL;
|
202 |
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int cluster_size = MSDOS_SB(sb)->cluster_size;
|
203 |
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|
204 |
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if (MSDOS_SB(sb)->fat_bits != 32) {
|
205 |
|
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if (inode->i_ino == MSDOS_ROOT_INO)
|
206 |
|
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return res;
|
207 |
|
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}
|
208 |
|
|
|
209 |
|
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nr = fat_add_cluster(inode);
|
210 |
|
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if (nr < 0)
|
211 |
|
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return res;
|
212 |
|
|
|
213 |
|
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sector = MSDOS_SB(sb)->data_start + (nr - 2) * cluster_size;
|
214 |
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last_sector = sector + cluster_size;
|
215 |
|
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if (MSDOS_SB(sb)->cvf_format && MSDOS_SB(sb)->cvf_format->zero_out_cluster)
|
216 |
|
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MSDOS_SB(sb)->cvf_format->zero_out_cluster(inode, nr);
|
217 |
|
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else {
|
218 |
|
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for ( ; sector < last_sector; sector++) {
|
219 |
|
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#ifdef DEBUG
|
220 |
|
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printk("zeroing sector %d\n", sector);
|
221 |
|
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#endif
|
222 |
|
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if (!(bh = fat_getblk(sb, sector)))
|
223 |
|
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printk("getblk failed\n");
|
224 |
|
|
else {
|
225 |
|
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memset(bh->b_data, 0, sb->s_blocksize);
|
226 |
|
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fat_set_uptodate(sb, bh, 1);
|
227 |
|
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fat_mark_buffer_dirty(sb, bh);
|
228 |
|
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if (!res)
|
229 |
|
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res = bh;
|
230 |
|
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else
|
231 |
|
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fat_brelse(sb, bh);
|
232 |
|
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}
|
233 |
|
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}
|
234 |
|
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}
|
235 |
|
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if (inode->i_size & (sb->s_blocksize - 1)) {
|
236 |
|
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fat_fs_panic(sb, "Odd directory size");
|
237 |
|
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inode->i_size = (inode->i_size + sb->s_blocksize)
|
238 |
|
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& ~(sb->s_blocksize - 1);
|
239 |
|
|
}
|
240 |
|
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inode->i_size += 1 << MSDOS_SB(sb)->cluster_bits;
|
241 |
|
|
MSDOS_I(inode)->mmu_private += 1 << MSDOS_SB(sb)->cluster_bits;
|
242 |
|
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mark_inode_dirty(inode);
|
243 |
|
|
|
244 |
|
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return res;
|
245 |
|
|
}
|
246 |
|
|
|
247 |
|
|
/* Linear day numbers of the respective 1sts in non-leap years. */
|
248 |
|
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|
249 |
|
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static int day_n[] = { 0,31,59,90,120,151,181,212,243,273,304,334,0,0,0,0 };
|
250 |
|
|
/* JanFebMarApr May Jun Jul Aug Sep Oct Nov Dec */
|
251 |
|
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|
252 |
|
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|
253 |
|
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extern struct timezone sys_tz;
|
254 |
|
|
|
255 |
|
|
|
256 |
|
|
/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */
|
257 |
|
|
|
258 |
|
|
int date_dos2unix(unsigned short time,unsigned short date)
|
259 |
|
|
{
|
260 |
|
|
int month,year,secs;
|
261 |
|
|
|
262 |
|
|
/* first subtract and mask after that... Otherwise, if
|
263 |
|
|
date == 0, bad things happen */
|
264 |
|
|
month = ((date >> 5) - 1) & 15;
|
265 |
|
|
year = date >> 9;
|
266 |
|
|
secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400*
|
267 |
|
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((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
|
268 |
|
|
month < 2 ? 1 : 0)+3653);
|
269 |
|
|
/* days since 1.1.70 plus 80's leap day */
|
270 |
|
|
secs += sys_tz.tz_minuteswest*60;
|
271 |
|
|
return secs;
|
272 |
|
|
}
|
273 |
|
|
|
274 |
|
|
|
275 |
|
|
/* Convert linear UNIX date to a MS-DOS time/date pair. */
|
276 |
|
|
|
277 |
|
|
void fat_date_unix2dos(int unix_date,unsigned short *time,
|
278 |
|
|
unsigned short *date)
|
279 |
|
|
{
|
280 |
|
|
int day,year,nl_day,month;
|
281 |
|
|
|
282 |
|
|
unix_date -= sys_tz.tz_minuteswest*60;
|
283 |
|
|
|
284 |
|
|
/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
|
285 |
|
|
if (unix_date < 315532800)
|
286 |
|
|
unix_date = 315532800;
|
287 |
|
|
|
288 |
|
|
*time = (unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
|
289 |
|
|
(((unix_date/3600) % 24) << 11);
|
290 |
|
|
day = unix_date/86400-3652;
|
291 |
|
|
year = day/365;
|
292 |
|
|
if ((year+3)/4+365*year > day) year--;
|
293 |
|
|
day -= (year+3)/4+365*year;
|
294 |
|
|
if (day == 59 && !(year & 3)) {
|
295 |
|
|
nl_day = day;
|
296 |
|
|
month = 2;
|
297 |
|
|
}
|
298 |
|
|
else {
|
299 |
|
|
nl_day = (year & 3) || day <= 59 ? day : day-1;
|
300 |
|
|
for (month = 0; month < 12; month++)
|
301 |
|
|
if (day_n[month] > nl_day) break;
|
302 |
|
|
}
|
303 |
|
|
*date = nl_day-day_n[month-1]+1+(month << 5)+(year << 9);
|
304 |
|
|
}
|
305 |
|
|
|
306 |
|
|
|
307 |
|
|
/* Returns the inode number of the directory entry at offset pos. If bh is
|
308 |
|
|
non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
|
309 |
|
|
returned in bh.
|
310 |
|
|
AV. Most often we do it item-by-item. Makes sense to optimize.
|
311 |
|
|
AV. OK, there we go: if both bh and de are non-NULL we assume that we just
|
312 |
|
|
AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
|
313 |
|
|
AV. It's done in fat_get_entry() (inlined), here the slow case lives.
|
314 |
|
|
AV. Additionally, when we return -1 (i.e. reached the end of directory)
|
315 |
|
|
AV. we make bh NULL.
|
316 |
|
|
*/
|
317 |
|
|
|
318 |
|
|
int fat__get_entry(struct inode *dir, loff_t *pos,struct buffer_head **bh,
|
319 |
|
|
struct msdos_dir_entry **de, loff_t *i_pos)
|
320 |
|
|
{
|
321 |
|
|
struct super_block *sb = dir->i_sb;
|
322 |
|
|
struct msdos_sb_info *sbi = MSDOS_SB(sb);
|
323 |
|
|
int sector;
|
324 |
|
|
loff_t offset;
|
325 |
|
|
|
326 |
|
|
while (1) {
|
327 |
|
|
offset = *pos;
|
328 |
|
|
PRINTK (("get_entry offset %d\n",offset));
|
329 |
|
|
if (*bh)
|
330 |
|
|
fat_brelse(sb, *bh);
|
331 |
|
|
*bh = NULL;
|
332 |
|
|
if ((sector = fat_bmap(dir,offset >> sb->s_blocksize_bits)) == -1)
|
333 |
|
|
return -1;
|
334 |
|
|
PRINTK (("get_entry sector %d %p\n",sector,*bh));
|
335 |
|
|
PRINTK (("get_entry sector apres brelse\n"));
|
336 |
|
|
if (!sector)
|
337 |
|
|
return -1; /* beyond EOF */
|
338 |
|
|
*pos += sizeof(struct msdos_dir_entry);
|
339 |
|
|
if (!(*bh = fat_bread(sb, sector))) {
|
340 |
|
|
printk("Directory sread (sector 0x%x) failed\n",sector);
|
341 |
|
|
continue;
|
342 |
|
|
}
|
343 |
|
|
PRINTK (("get_entry apres sread\n"));
|
344 |
|
|
|
345 |
|
|
offset &= sb->s_blocksize - 1;
|
346 |
|
|
*de = (struct msdos_dir_entry *) ((*bh)->b_data + offset);
|
347 |
|
|
*i_pos = ((loff_t)sector << sbi->dir_per_block_bits) + (offset >> MSDOS_DIR_BITS);
|
348 |
|
|
|
349 |
|
|
return 0;
|
350 |
|
|
}
|
351 |
|
|
}
|
352 |
|
|
|
353 |
|
|
|
354 |
|
|
/*
|
355 |
|
|
* Now an ugly part: this set of directory scan routines works on clusters
|
356 |
|
|
* rather than on inodes and sectors. They are necessary to locate the '..'
|
357 |
|
|
* directory "inode". raw_scan_sector operates in four modes:
|
358 |
|
|
*
|
359 |
|
|
* name number ino action
|
360 |
|
|
* -------- -------- -------- -------------------------------------------------
|
361 |
|
|
* non-NULL - X Find an entry with that name
|
362 |
|
|
* NULL non-NULL non-NULL Find an entry whose data starts at *number
|
363 |
|
|
* NULL non-NULL NULL Count subdirectories in *number. (*)
|
364 |
|
|
* NULL NULL non-NULL Find an empty entry
|
365 |
|
|
*
|
366 |
|
|
* (*) The return code should be ignored. It DOES NOT indicate success or
|
367 |
|
|
* failure. *number has to be initialized to zero.
|
368 |
|
|
*
|
369 |
|
|
* - = not used, X = a value is returned unless NULL
|
370 |
|
|
*
|
371 |
|
|
* If res_bh is non-NULL, the buffer is not deallocated but returned to the
|
372 |
|
|
* caller on success. res_de is set accordingly.
|
373 |
|
|
*
|
374 |
|
|
* If cont is non-zero, raw_found continues with the entry after the one
|
375 |
|
|
* res_bh/res_de point to.
|
376 |
|
|
*/
|
377 |
|
|
|
378 |
|
|
|
379 |
|
|
#define RSS_NAME /* search for name */ \
|
380 |
|
|
done = !strncmp(data[entry].name,name,MSDOS_NAME) && \
|
381 |
|
|
!(data[entry].attr & ATTR_VOLUME);
|
382 |
|
|
|
383 |
|
|
#define RSS_START /* search for start cluster */ \
|
384 |
|
|
done = !IS_FREE(data[entry].name) \
|
385 |
|
|
&& ( \
|
386 |
|
|
( \
|
387 |
|
|
(sbi->fat_bits != 32) ? 0 : (CF_LE_W(data[entry].starthi) << 16) \
|
388 |
|
|
) \
|
389 |
|
|
| CF_LE_W(data[entry].start) \
|
390 |
|
|
) == *number;
|
391 |
|
|
|
392 |
|
|
#define RSS_FREE /* search for free entry */ \
|
393 |
|
|
{ \
|
394 |
|
|
done = IS_FREE(data[entry].name); \
|
395 |
|
|
}
|
396 |
|
|
|
397 |
|
|
#define RSS_COUNT /* count subdirectories */ \
|
398 |
|
|
{ \
|
399 |
|
|
done = 0; \
|
400 |
|
|
if (!IS_FREE(data[entry].name) && (data[entry].attr & ATTR_DIR)) \
|
401 |
|
|
(*number)++; \
|
402 |
|
|
}
|
403 |
|
|
|
404 |
|
|
static int raw_scan_sector(struct super_block *sb, int sector,
|
405 |
|
|
const char *name, int *number, loff_t *i_pos,
|
406 |
|
|
struct buffer_head **res_bh,
|
407 |
|
|
struct msdos_dir_entry **res_de)
|
408 |
|
|
{
|
409 |
|
|
struct msdos_sb_info *sbi = MSDOS_SB(sb);
|
410 |
|
|
struct buffer_head *bh;
|
411 |
|
|
struct msdos_dir_entry *data;
|
412 |
|
|
int entry,start,done;
|
413 |
|
|
|
414 |
|
|
if (!(bh = fat_bread(sb, sector)))
|
415 |
|
|
return -EIO;
|
416 |
|
|
data = (struct msdos_dir_entry *) bh->b_data;
|
417 |
|
|
for (entry = 0; entry < sbi->dir_per_block; entry++) {
|
418 |
|
|
/* RSS_COUNT: if (data[entry].name == name) done=true else done=false. */
|
419 |
|
|
if (name) {
|
420 |
|
|
RSS_NAME
|
421 |
|
|
} else {
|
422 |
|
|
if (!i_pos) RSS_COUNT
|
423 |
|
|
else {
|
424 |
|
|
if (number) RSS_START
|
425 |
|
|
else RSS_FREE
|
426 |
|
|
}
|
427 |
|
|
}
|
428 |
|
|
if (done) {
|
429 |
|
|
if (i_pos) {
|
430 |
|
|
*i_pos = ((loff_t)sector << sbi->dir_per_block_bits) + entry;
|
431 |
|
|
}
|
432 |
|
|
start = CF_LE_W(data[entry].start);
|
433 |
|
|
if (sbi->fat_bits == 32)
|
434 |
|
|
start |= (CF_LE_W(data[entry].starthi) << 16);
|
435 |
|
|
|
436 |
|
|
if (!res_bh)
|
437 |
|
|
fat_brelse(sb, bh);
|
438 |
|
|
else {
|
439 |
|
|
*res_bh = bh;
|
440 |
|
|
*res_de = &data[entry];
|
441 |
|
|
}
|
442 |
|
|
return start;
|
443 |
|
|
}
|
444 |
|
|
}
|
445 |
|
|
fat_brelse(sb, bh);
|
446 |
|
|
return -ENOENT;
|
447 |
|
|
}
|
448 |
|
|
|
449 |
|
|
|
450 |
|
|
/*
|
451 |
|
|
* raw_scan_root performs raw_scan_sector on the root directory until the
|
452 |
|
|
* requested entry is found or the end of the directory is reached.
|
453 |
|
|
*/
|
454 |
|
|
|
455 |
|
|
static int raw_scan_root(struct super_block *sb, const char *name,
|
456 |
|
|
int *number, loff_t *i_pos,
|
457 |
|
|
struct buffer_head **res_bh,
|
458 |
|
|
struct msdos_dir_entry **res_de)
|
459 |
|
|
{
|
460 |
|
|
int count,cluster;
|
461 |
|
|
|
462 |
|
|
for (count = 0;
|
463 |
|
|
count < MSDOS_SB(sb)->dir_entries / MSDOS_SB(sb)->dir_per_block;
|
464 |
|
|
count++) {
|
465 |
|
|
cluster = raw_scan_sector(sb, MSDOS_SB(sb)->dir_start + count,
|
466 |
|
|
name, number, i_pos, res_bh, res_de);
|
467 |
|
|
if (cluster >= 0)
|
468 |
|
|
return cluster;
|
469 |
|
|
}
|
470 |
|
|
return -ENOENT;
|
471 |
|
|
}
|
472 |
|
|
|
473 |
|
|
|
474 |
|
|
/*
|
475 |
|
|
* raw_scan_nonroot performs raw_scan_sector on a non-root directory until the
|
476 |
|
|
* requested entry is found or the end of the directory is reached.
|
477 |
|
|
*/
|
478 |
|
|
|
479 |
|
|
static int raw_scan_nonroot(struct super_block *sb, int start, const char *name,
|
480 |
|
|
int *number, loff_t *i_pos,
|
481 |
|
|
struct buffer_head **res_bh,
|
482 |
|
|
struct msdos_dir_entry **res_de)
|
483 |
|
|
{
|
484 |
|
|
struct msdos_sb_info *sbi = MSDOS_SB(sb);
|
485 |
|
|
int count, cluster, sector;
|
486 |
|
|
|
487 |
|
|
#ifdef DEBUG
|
488 |
|
|
printk("raw_scan_nonroot: start=%d\n",start);
|
489 |
|
|
#endif
|
490 |
|
|
do {
|
491 |
|
|
for (count = 0; count < sbi->cluster_size; count++) {
|
492 |
|
|
sector = (start - 2) * sbi->cluster_size
|
493 |
|
|
+ count + sbi->data_start;
|
494 |
|
|
cluster = raw_scan_sector(sb, sector, name, number,
|
495 |
|
|
i_pos, res_bh, res_de);
|
496 |
|
|
if (cluster >= 0)
|
497 |
|
|
return cluster;
|
498 |
|
|
}
|
499 |
|
|
if (!(start = fat_access(sb,start,-1))) {
|
500 |
|
|
fat_fs_panic(sb,"FAT error");
|
501 |
|
|
break;
|
502 |
|
|
}
|
503 |
|
|
#ifdef DEBUG
|
504 |
|
|
printk("next start: %d\n",start);
|
505 |
|
|
#endif
|
506 |
|
|
}
|
507 |
|
|
while (start != -1);
|
508 |
|
|
return -ENOENT;
|
509 |
|
|
}
|
510 |
|
|
|
511 |
|
|
|
512 |
|
|
/*
|
513 |
|
|
* raw_scan performs raw_scan_sector on any sector.
|
514 |
|
|
*
|
515 |
|
|
* NOTE: raw_scan must not be used on a directory that is is the process of
|
516 |
|
|
* being created.
|
517 |
|
|
*/
|
518 |
|
|
|
519 |
|
|
static int raw_scan(struct super_block *sb, int start, const char *name,
|
520 |
|
|
loff_t *i_pos, struct buffer_head **res_bh,
|
521 |
|
|
struct msdos_dir_entry **res_de)
|
522 |
|
|
{
|
523 |
|
|
if (start)
|
524 |
|
|
return raw_scan_nonroot(sb,start,name,NULL,i_pos,res_bh,res_de);
|
525 |
|
|
else
|
526 |
|
|
return raw_scan_root(sb,name,NULL,i_pos,res_bh,res_de);
|
527 |
|
|
}
|
528 |
|
|
|
529 |
|
|
/*
|
530 |
|
|
* fat_subdirs counts the number of sub-directories of dir. It can be run
|
531 |
|
|
* on directories being created.
|
532 |
|
|
*/
|
533 |
|
|
int fat_subdirs(struct inode *dir)
|
534 |
|
|
{
|
535 |
|
|
struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
|
536 |
|
|
int number;
|
537 |
|
|
|
538 |
|
|
number = 0;
|
539 |
|
|
if ((dir->i_ino == MSDOS_ROOT_INO) && (sbi->fat_bits != 32))
|
540 |
|
|
raw_scan_root(dir->i_sb, NULL, &number, NULL, NULL, NULL);
|
541 |
|
|
else {
|
542 |
|
|
if ((dir->i_ino != MSDOS_ROOT_INO) && !MSDOS_I(dir)->i_start)
|
543 |
|
|
return 0; /* in mkdir */
|
544 |
|
|
else {
|
545 |
|
|
raw_scan_nonroot(dir->i_sb, MSDOS_I(dir)->i_start,
|
546 |
|
|
NULL, &number, NULL, NULL, NULL);
|
547 |
|
|
}
|
548 |
|
|
}
|
549 |
|
|
return number;
|
550 |
|
|
}
|
551 |
|
|
|
552 |
|
|
|
553 |
|
|
/*
|
554 |
|
|
* Scans a directory for a given file (name points to its formatted name) or
|
555 |
|
|
* for an empty directory slot (name is NULL). Returns an error code or zero.
|
556 |
|
|
*/
|
557 |
|
|
|
558 |
|
|
int fat_scan(struct inode *dir, const char *name, struct buffer_head **res_bh,
|
559 |
|
|
struct msdos_dir_entry **res_de, loff_t *i_pos)
|
560 |
|
|
{
|
561 |
|
|
int res;
|
562 |
|
|
|
563 |
|
|
res = raw_scan(dir->i_sb, MSDOS_I(dir)->i_start, name, i_pos,
|
564 |
|
|
res_bh, res_de);
|
565 |
|
|
return (res < 0) ? res : 0;
|
566 |
|
|
}
|