fs/minix/dir.c

/* */
This source file includes following definitions.
minix_dir_read
minix_readdir
   1 /*
   2  *  linux/fs/minix/dir.c
   3  *
   4  *  Copyright (C) 1991, 1992 Linus Torvalds
   5  *
   6  *  minix directory handling functions
   7  */
   8 
   9 #include <linux/string.h>
  10 #include <linux/errno.h>
  11 #include <linux/fs.h>
  12 #include <linux/minix_fs.h>
  13 #include <linux/stat.h>
  14 
  15 #include <asm/segment.h>
  16 
  17 static int minix_dir_read(struct inode * inode, struct file * filp, char * buf, int count)
     /*  */
  18 {
  19         return -EISDIR;
  20 }
  21 
  22 static int minix_readdir(struct inode *, struct file *, void *, filldir_t);
  23 
  24 static struct file_operations minix_dir_operations = {
  25         NULL,                   /* lseek - default */
  26         minix_dir_read,         /* read */
  27         NULL,                   /* write - bad */
  28         minix_readdir,          /* readdir */
  29         NULL,                   /* select - default */
  30         NULL,                   /* ioctl - default */
  31         NULL,                   /* mmap */
  32         NULL,                   /* no special open code */
  33         NULL,                   /* no special release code */
  34         file_fsync              /* default fsync */
  35 };
  36 
  37 /*
  38  * directories can handle most operations...
  39  */
  40 struct inode_operations minix_dir_inode_operations = {
  41         &minix_dir_operations,  /* default directory file-ops */
  42         minix_create,           /* create */
  43         minix_lookup,           /* lookup */
  44         minix_link,             /* link */
  45         minix_unlink,           /* unlink */
  46         minix_symlink,          /* symlink */
  47         minix_mkdir,            /* mkdir */
  48         minix_rmdir,            /* rmdir */
  49         minix_mknod,            /* mknod */
  50         minix_rename,           /* rename */
  51         NULL,                   /* readlink */
  52         NULL,                   /* follow_link */
  53         NULL,                   /* readpage */
  54         NULL,                   /* writepage */
  55         NULL,                   /* bmap */
  56         minix_truncate,         /* truncate */
  57         NULL                    /* permission */
  58 };
  59 
  60 static int minix_readdir(struct inode * inode, struct file * filp,
     /*  */
  61         void * dirent, filldir_t filldir)
  62 {
  63         unsigned int offset;
  64         struct buffer_head * bh;
  65         struct minix_dir_entry * de;
  66         struct minix_sb_info * info;
  67 
  68         if (!inode || !inode->i_sb || !S_ISDIR(inode->i_mode))
  69                 return -EBADF;
  70         info = &inode->i_sb->u.minix_sb;
  71         if (filp->f_pos & (info->s_dirsize - 1))
  72                 return -EBADF;
  73         while (filp->f_pos < inode->i_size) {
  74                 offset = filp->f_pos & 1023;
  75                 bh = minix_bread(inode,(filp->f_pos)>>BLOCK_SIZE_BITS,0);
  76                 if (!bh) {
  77                         filp->f_pos += 1024-offset;
  78                         continue;
  79                 }
  80                 do {
  81                         de = (struct minix_dir_entry *) (offset + bh->b_data);
  82                         if (de->inode) {
  83                                 int size = strnlen(de->name, info->s_namelen);
  84                                 if (filldir(dirent, de->name, size, filp->f_pos, de->inode) < 0) {
  85                                         brelse(bh);
  86                                         return 0;
  87                                 }
  88                         }
  89                         offset += info->s_dirsize;
  90                         filp->f_pos += info->s_dirsize;
  91                 } while (offset < 1024 && filp->f_pos < inode->i_size);
  92                 brelse(bh);
  93         }
  94         return 0;
  95 }
/* */
root/fs/minix/dir.c

DEFINITIONS
