fs/msdos/dir.c

/* */
This source file includes following definitions.
msdos_dummy_read
msdos_readdir
   1 /*
   2  *  linux/fs/msdos/dir.c
   3  *
   4  *  Written 1992 by Werner Almesberger
   5  *
   6  *  MS-DOS directory handling functions
   7  */
   8 
   9 #include <asm/segment.h>
  10 
  11 #include <linux/sched.h>
  12 #include <linux/fs.h>
  13 #include <linux/msdos_fs.h>
  14 #include <linux/errno.h>
  15 #include <linux/stat.h>
  16 
  17 static int msdos_dummy_read(struct inode *inode,struct file *filp,char *buf,
  18     int count);
  19 static int msdos_readdir(struct inode *inode,struct file *filp,
  20     struct dirent *dirent,int count);
  21 
  22 
  23 static struct file_operations msdos_dir_operations = {
  24         NULL,                   /* lseek - default */
  25         msdos_dummy_read,       /* read */
  26         NULL,                   /* write - bad */
  27         msdos_readdir,          /* readdir */
  28         NULL,                   /* select - default */
  29         NULL,                   /* ioctl - default */
  30         NULL,                   /* no special open code */
  31         NULL                    /* no special release code */
  32 };
  33 
  34 struct inode_operations msdos_dir_inode_operations = {
  35         &msdos_dir_operations,  /* default directory file-ops */
  36         msdos_create,           /* create */
  37         msdos_lookup,           /* lookup */
  38         NULL,                   /* link */
  39         msdos_unlink,           /* unlink */
  40         NULL,                   /* symlink */
  41         msdos_mkdir,            /* mkdir */
  42         msdos_rmdir,            /* rmdir */
  43         NULL,                   /* mknod */
  44         msdos_rename,           /* rename */
  45         NULL,                   /* readlink */
  46         NULL,                   /* follow_link */
  47         msdos_bmap,             /* bmap */
  48         NULL                    /* truncate */
  49 };
  50 
  51 
  52 /* So  grep *  doesn't complain in the presence of directories. */
  53 
  54 static int msdos_dummy_read(struct inode *inode,struct file *filp,char *buf,
     /*  */
  55     int count)
  56 {
  57         static long last_warning = 0;
  58 
  59         if (CURRENT_TIME-last_warning >= 10) {
  60                 printk("COMPATIBILITY WARNING: reading a directory\n");
  61                 last_warning = CURRENT_TIME;
  62         }
  63         return 0;
  64 }
  65 
  66 
  67 static int msdos_readdir(struct inode *inode,struct file *filp,
     /*  */
  68     struct dirent *dirent,int count)
  69 {
  70         int ino,i,i2,last;
  71         char c,*walk;
  72         struct buffer_head *bh;
  73         struct msdos_dir_entry *de;
  74 
  75         if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF;
  76         if (inode->i_ino == MSDOS_ROOT_INO) {
  77 /* Fake . and .. for the root directory. */
  78                 if (filp->f_pos == 2) filp->f_pos = 0;
  79                 else if (filp->f_pos < 2) {
  80                                 walk = filp->f_pos++ ? ".." : ".";
  81                                 for (i = 0; *walk; walk++)
  82                                         put_fs_byte(*walk,dirent->d_name+i++);
  83                                 put_fs_long(MSDOS_ROOT_INO,&dirent->d_ino);
  84                                 put_fs_byte(0,dirent->d_name+i);
  85                                 put_fs_word(i,&dirent->d_reclen);
  86                                 return i;
  87                         }
  88         }
  89         if (filp->f_pos & (sizeof(struct msdos_dir_entry)-1)) return -ENOENT;
  90         bh = NULL;
  91         while ((ino = msdos_get_entry(inode,&filp->f_pos,&bh,&de)) > -1) {
  92                 if (de->name[0] && ((unsigned char *) (de->name))[0] !=
  93                     DELETED_FLAG && !(de->attr & ATTR_VOLUME)) {
  94                         for (i = last = 0; i < 8; i++) {
  95                                 if (!(c = de->name[i])) break;
  96                                 if (c >= 'A' && c <= 'Z') c += 32;
  97                                 if (c != ' ') last = i+1;
  98                                 put_fs_byte(c,i+dirent->d_name);
  99                         }
 100                         i = last;
 101                         if (de->ext[0] && de->ext[0] != ' ') {
 102                                 put_fs_byte('.',i+dirent->d_name);
 103                                 i++;
 104                                 for (i2 = 0; i2 < 3; i2++) {
 105                                         if (!(c = de->ext[i2])) break;
 106                                         if (c >= 'A' && c <= 'Z') c += 32;
 107                                         put_fs_byte(c,i+dirent->d_name);
 108                                         i++;
 109                                         if (c != ' ') last = i;
 110                                 }
 111                         }
 112                         if (i = last) {
 113                                 if (!strcmp(de->name,MSDOS_DOT))
 114                                         ino = inode->i_ino;
 115                                 else if (!strcmp(de->name,MSDOS_DOTDOT))
 116                                                 ino = msdos_parent_ino(inode,0);
 117                                 put_fs_long(ino,&dirent->d_ino);
 118                                 put_fs_byte(0,i+dirent->d_name);
 119                                 put_fs_word(i,&dirent->d_reclen);
 120                                 brelse(bh);
 121                                 return i;
 122                         }
 123                 }
 124         }
 125         if (bh) brelse(bh);
 126         return 0;
 127 }
/* */
root/fs/msdos/dir.c

DEFINITIONS
