fs/sysv/dir.c

/* */
This source file includes following definitions.
sysv_dir_read
sysv_readdir
   1 /*
   2  *  linux/fs/sysv/dir.c
   3  *
   4  *  minix/dir.c
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *
   7  *  coh/dir.c
   8  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
   9  *
  10  *  sysv/dir.c
  11  *  Copyright (C) 1993  Bruno Haible
  12  *
  13  *  SystemV/Coherent directory handling functions
  14  */
  15 
  16 #include <asm/segment.h>
  17 
  18 #include <linux/errno.h>
  19 #include <linux/fs.h>
  20 #include <linux/sysv_fs.h>
  21 #include <linux/stat.h>
  22 
  23 static int sysv_dir_read(struct inode * inode, struct file * filp, char * buf, int count)
     /*  */
  24 {
  25         return -EISDIR;
  26 }
  27 
  28 static int sysv_readdir(struct inode *, struct file *, struct dirent *, int);
  29 
  30 static struct file_operations sysv_dir_operations = {
  31         NULL,                   /* lseek - default */
  32         sysv_dir_read,          /* read */
  33         NULL,                   /* write - bad */
  34         sysv_readdir,           /* readdir */
  35         NULL,                   /* select - default */
  36         NULL,                   /* ioctl - default */
  37         NULL,                   /* mmap */
  38         NULL,                   /* no special open code */
  39         NULL,                   /* no special release code */
  40         file_fsync              /* default fsync */
  41 };
  42 
  43 /*
  44  * directories can handle most operations...
  45  */
  46 struct inode_operations sysv_dir_inode_operations = {
  47         &sysv_dir_operations,   /* default directory file-ops */
  48         sysv_create,            /* create */
  49         sysv_lookup,            /* lookup */
  50         sysv_link,              /* link */
  51         sysv_unlink,            /* unlink */
  52         sysv_symlink,           /* symlink */
  53         sysv_mkdir,             /* mkdir */
  54         sysv_rmdir,             /* rmdir */
  55         sysv_mknod,             /* mknod */
  56         sysv_rename,            /* rename */
  57         NULL,                   /* readlink */
  58         NULL,                   /* follow_link */
  59         NULL,                   /* bmap */
  60         sysv_truncate,          /* truncate */
  61         NULL                    /* permission */
  62 };
  63 
  64 static int sysv_readdir(struct inode * inode, struct file * filp,
     /*  */
  65         struct dirent * dirent, int count)
  66 {
  67         struct super_block * sb;
  68         unsigned int offset,i;
  69         char c;
  70         struct buffer_head * bh;
  71         char* bh_data;
  72         struct sysv_dir_entry * de;
  73 
  74         if (!inode || !(sb = inode->i_sb) || !S_ISDIR(inode->i_mode))
  75                 return -EBADF;
  76         if ((unsigned long)(filp->f_pos) % SYSV_DIRSIZE)
  77                 return -EBADF;
  78         while (filp->f_pos < inode->i_size) {
  79                 offset = filp->f_pos & sb->sv_block_size_1;
  80                 bh = sysv_file_bread(inode, filp->f_pos >> sb->sv_block_size_bits, 0, &bh_data);
  81                 if (!bh) {
  82                         filp->f_pos += sb->sv_block_size - offset;
  83                         continue;
  84                 }
  85                 while (offset < sb->sv_block_size && filp->f_pos < inode->i_size) {
  86                         de = (struct sysv_dir_entry *) (offset + bh_data);
  87                         offset += SYSV_DIRSIZE;
  88                         filp->f_pos += SYSV_DIRSIZE;
  89                         if (de->inode) {
  90                                 for (i = 0; i < SYSV_NAMELEN; i++)
  91                                         if ((c = de->name[i]) != 0)
  92                                                 put_fs_byte(c,i+dirent->d_name);
  93                                         else
  94                                                 break;
  95                                 if (i) {
  96                                         if (de->inode > inode->i_sb->sv_ninodes)
  97                                                 printk("sysv_readdir: Bad inode number on dev 0x%04x, ino %ld, offset 0x%04lx: %d is out of range\n",
  98                                                         inode->i_dev, inode->i_ino, filp->f_pos - SYSV_DIRSIZE, de->inode);
  99                                         put_fs_long(de->inode,&dirent->d_ino);
 100                                         put_fs_byte(0,i+dirent->d_name);
 101                                         put_fs_word(i,&dirent->d_reclen);
 102                                         brelse(bh);
 103                                         return i;
 104                                 }
 105                         }
 106                 }
 107                 brelse(bh);
 108         }
 109         return 0;
 110 }
/* */
root/fs/sysv/dir.c

DEFINITIONS
