/* * linux/fs/minix/dir.c * * (C) 1991 Linus Torvalds * * minix directory handling functions */ #include <errno.h> #include <asm/segment.h> #include <linux/fs.h> #include <linux/minix_fs.h> #include <linux/stat.h> static int minix_readdir(struct inode *, struct file *, struct dirent *, int); static struct file_operations minix_dir_operations = { NULL, /* lseek - default */ minix_file_read, /* read */ NULL, /* write - bad */ minix_readdir, /* readdir */ NULL, /* select - default */ NULL, /* ioctl - default */ NULL, /* no special open code */ NULL /* no special release code */ }; /* * directories can handle most operations... */ struct inode_operations minix_dir_inode_operations = { &minix_dir_operations, /* default directory file-ops */ minix_create, /* create */ minix_lookup, /* lookup */ minix_link, /* link */ minix_unlink, /* unlink */ minix_symlink, /* symlink */ minix_mkdir, /* mkdir */ minix_rmdir, /* rmdir */ minix_mknod, /* mknod */ minix_rename, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ minix_bmap, /* bmap */ minix_truncate /* truncate */ }; static int minix_readdir(struct inode * inode, struct file * filp, struct dirent * dirent, int count) { unsigned int block,offset,i; char c; struct buffer_head * bh; struct minix_dir_entry * de; if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF; if (filp->f_pos & (sizeof (struct minix_dir_entry) - 1)) return -EBADF; while (filp->f_pos < inode->i_size) { offset = filp->f_pos & 1023; block = minix_bmap(inode,(filp->f_pos)>>BLOCK_SIZE_BITS); if (!block || !(bh = bread(inode->i_dev,block))) { filp->f_pos += 1024-offset; continue; } de = (struct minix_dir_entry *) (offset + bh->b_data); while (offset < 1024 && filp->f_pos < inode->i_size) { offset += sizeof (struct minix_dir_entry); filp->f_pos += sizeof (struct minix_dir_entry); if (de->inode) { for (i = 0; i < MINIX_NAME_LEN; i++) if (c = de->name[i]) put_fs_byte(c,i+dirent->d_name); else break; if (i) { put_fs_long(de->inode,&dirent->d_ino); put_fs_byte(0,i+dirent->d_name); put_fs_word(i,&dirent->d_reclen); brelse(bh); return i; } } de++; } brelse(bh); } return 0; }