/* * linux/fs/xiafs/dir.c * * Copyright (C) Q. Frank Xia, 1993. * * Based on Linus' minix/dir.c * Copyright (C) Linus Torvalds, 1991, 1992. * * This software may be redistributed per Linux Copyright. */ #ifdef MODULE #include #endif #include #include #include #include #include #include #include #include "xiafs_mac.h" #define NAME_OFFSET(de) ((int) ((de)->d_name - (char *) (de))) #define ROUND_UP(x) (((x)+3) & ~3) static int xiafs_dir_read(struct inode *, struct file *, char *, int); static int xiafs_readdir(struct inode *, struct file *, struct dirent *, int); static struct file_operations xiafs_dir_operations = { NULL, /* lseek - default */ xiafs_dir_read, /* read */ NULL, /* write - bad */ xiafs_readdir, /* readdir */ NULL, /* select - default */ NULL, /* ioctl - default */ NULL, /* mmap */ NULL, /* no special open code */ NULL, /* no special release code */ file_fsync /* default fsync */ }; /* * directories can handle most operations... */ struct inode_operations xiafs_dir_inode_operations = { &xiafs_dir_operations, /* default directory file-ops */ xiafs_create, /* create */ xiafs_lookup, /* lookup */ xiafs_link, /* link */ xiafs_unlink, /* unlink */ xiafs_symlink, /* symlink */ xiafs_mkdir, /* mkdir */ xiafs_rmdir, /* rmdir */ xiafs_mknod, /* mknod */ xiafs_rename, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* bmap */ xiafs_truncate, /* truncate */ NULL /* permission */ }; static int xiafs_dir_read(struct inode * inode, struct file * filp, char * buf, int count) { return -EISDIR; } static int xiafs_readdir(struct inode * inode, struct file * filp, struct dirent * dirent, int count) { u_int offset, i,ret; struct buffer_head * bh; struct xiafs_direct * de; if (!inode || !inode->i_sb || !S_ISDIR(inode->i_mode)) return -EBADF; if (inode->i_size & (XIAFS_ZSIZE(inode->i_sb) - 1) ) return -EBADF; ret = 0; while (!ret && filp->f_pos < inode->i_size) { offset = filp->f_pos & (XIAFS_ZSIZE(inode->i_sb) - 1); bh = xiafs_bread(inode, filp->f_pos >> XIAFS_ZSIZE_BITS(inode->i_sb),0); if (!bh) { filp->f_pos += XIAFS_ZSIZE(inode->i_sb)-offset; continue; } for (i = 0; i < XIAFS_ZSIZE(inode->i_sb) && i < offset; ) { de = (struct xiafs_direct *) (bh->b_data + i); if (!de->d_rec_len) break; i += de->d_rec_len; } offset = i; de = (struct xiafs_direct *) (offset + bh->b_data); while (!ret && offset < XIAFS_ZSIZE(inode->i_sb) && filp->f_pos < inode->i_size) { if (de->d_ino > inode->i_sb->u.xiafs_sb.s_ninodes || de->d_rec_len < 12 || (char *)de+de->d_rec_len > XIAFS_ZSIZE(inode->i_sb)+bh->b_data || de->d_name_len < 1 || de->d_name_len + 8 > de->d_rec_len || de->d_name_len > _XIAFS_NAME_LEN || de->d_name[de->d_name_len] ) { printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR); brelse(bh); return 0; } offset += de->d_rec_len; filp->f_pos += de->d_rec_len; if (de->d_ino) { for (i = 0; i < de->d_name_len ; i++) put_fs_byte(de->d_name[i],i+dirent->d_name); put_fs_byte(0,i+dirent->d_name); put_fs_long(de->d_ino,&dirent->d_ino); put_fs_word(i,&dirent->d_reclen); if (!IS_RDONLY (inode)) { inode->i_atime=CURRENT_TIME; inode->i_dirt=1; } ret = ROUND_UP(NAME_OFFSET(dirent)+i+1); break; } de = (struct xiafs_direct *) (offset + bh->b_data); } brelse(bh); if (offset > XIAFS_ZSIZE(inode->i_sb)) { printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); return 0; } } if (!IS_RDONLY (inode)) { inode->i_atime=CURRENT_TIME; inode->i_dirt=1; } return ret; }