C++ coda_i2f函数代码示例

/* try to make de an entry in dir_inodde linked to source_de */ 
static int coda_link(struct dentry *source_de, struct inode *dir_inode, 
	  struct dentry *de)
{
	struct inode *inode = source_de->d_inode;
        const char * name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
		
#ifdef CONFIG_GOD_MODE
{
 if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif

	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
			   coda_i2f(dir_inode), (const char *)name, len);
	if (error) {
		d_drop(de);
		return error;
	}

	coda_dir_update_mtime(dir_inode);
	ihold(inode);
	d_instantiate(de, inode);
	inc_nlink(inode);
	return 0;
}

/* try to make de an entry in dir_inodde linked to source_de */ 
static int coda_link(struct dentry *source_de, struct inode *dir_inode, 
	  struct dentry *de)
{
	struct inode *inode = source_de->d_inode;
        const char * name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	lock_kernel();

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
		unlock_kernel();
		return -EPERM;
	}

	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
			   coda_i2f(dir_inode), (const char *)name, len);

	if (error) {
		d_drop(de);
		goto out;
	}

	coda_dir_update_mtime(dir_inode);
	atomic_inc(&inode->i_count);
	d_instantiate(de, inode);
	inc_nlink(inode);

out:
	unlock_kernel();
	return(error);
}

/* rename */
static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
		       struct inode *new_dir, struct dentry *new_dentry)
{
	const char *old_name = old_dentry->d_name.name;
	const char *new_name = new_dentry->d_name.name;
	int old_length = old_dentry->d_name.len;
	int new_length = new_dentry->d_name.len;
	int error;

	lock_kernel();

	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
			     coda_i2f(new_dir), old_length, new_length,
			     (const char *) old_name, (const char *)new_name);

	if ( !error ) {
		if ( new_dentry->d_inode ) {
			if ( S_ISDIR(new_dentry->d_inode->i_mode) ) {
				coda_dir_drop_nlink(old_dir);
				coda_dir_inc_nlink(new_dir);
			}
			coda_dir_update_mtime(old_dir);
			coda_dir_update_mtime(new_dir);
			coda_flag_inode(new_dentry->d_inode, C_VATTR);
		} else {
			coda_flag_inode(old_dir, C_VATTR);
			coda_flag_inode(new_dir, C_VATTR);
		}
	}
	unlock_kernel();

	return error;
}

/* try to make de an entry in dir_inodde linked to source_de */ 
static int coda_link(struct dentry *source_de, struct inode *dir_inode, 
	  struct dentry *de)
{
	struct inode *inode = source_de->d_inode;
        const char * name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	coda_vfs_stat.link++;

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
		return -EPERM;

	CDEBUG(D_INODE, "old: fid: %s\n", coda_i2s(inode));
	CDEBUG(D_INODE, "directory: %s\n", coda_i2s(dir_inode));

	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
			   coda_i2f(dir_inode), (const char *)name, len);

	if (error) { 
		d_drop(de);
		goto out;
	}

	coda_dir_changed(dir_inode, 0);
	atomic_inc(&inode->i_count);
	d_instantiate(de, inode);
	inode->i_nlink++;
        
out:
	CDEBUG(D_INODE, "link result %d\n",error);
	return(error);
}

/* rename */
static int coda_rename(struct inode *old_dir, struct dentry *old_dentry, 
		       struct inode *new_dir, struct dentry *new_dentry)
{
        const char *old_name = old_dentry->d_name.name;
        const char *new_name = new_dentry->d_name.name;
	int old_length = old_dentry->d_name.len;
	int new_length = new_dentry->d_name.len;
        int link_adjust = 0;
        int error;

	lock_kernel();
	coda_vfs_stat.rename++;

        error = venus_rename(old_dir->i_sb, coda_i2f(old_dir), 
			     coda_i2f(new_dir), old_length, new_length, 
			     (const char *) old_name, (const char *)new_name);

        if ( !error ) {
		if ( new_dentry->d_inode ) {
			if ( S_ISDIR(new_dentry->d_inode->i_mode) )
                        	link_adjust = 1;

                        coda_dir_changed(old_dir, -link_adjust);
                        coda_dir_changed(new_dir,  link_adjust);
			coda_flag_inode(new_dentry->d_inode, C_VATTR);
		} else {
			coda_flag_inode(old_dir, C_VATTR);
			coda_flag_inode(new_dir, C_VATTR);
                }
	}
	unlock_kernel();

	return error;
}

static int coda_symlink(struct inode *dir_inode, struct dentry *de,
			const char *symname)
{
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int symlen;
	int error;

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
		return -EPERM;

	symlen = strlen(symname);
	if (symlen > CODA_MAXPATHLEN)
		return -ENAMETOOLONG;

	/*
	 * This entry is now negative. Since we do not create
	 * an inode for the entry we have to drop it.
	 */
	d_drop(de);
	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
			      symname, symlen);

	/* mtime is no good anymore */
	if (!error)
		coda_dir_update_mtime(dir_inode);

	return error;
}

static int coda_mkdir(struct inode *dir, struct dentry *de, int mode)
{
	struct inode *inode;
	struct coda_vattr attrs;
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int error;
	struct CodaFid newfid;

	if (coda_isroot(dir) && coda_iscontrol(name, len))
		return -EPERM;

	attrs.va_mode = mode;
	error = venus_mkdir(dir->i_sb, coda_i2f(dir), 
			       name, len, &newfid, &attrs);
	if (error)
		goto err_out;
         
	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		goto err_out;
	}

	/* invalidate the directory cnode's attributes */
	coda_dir_inc_nlink(dir);
	coda_dir_update_mtime(dir);
	d_instantiate(de, inode);
	return 0;
err_out:
	d_drop(de);
	return error;
}

/* creation routines: create, mknod, mkdir, link, symlink */
static int coda_create(struct inode *dir, struct dentry *de, int mode, struct nameidata *nd)
{
	int error;
	const char *name=de->d_name.name;
	int length=de->d_name.len;
	struct inode *inode;
	struct CodaFid newfid;
	struct coda_vattr attrs;

	if (coda_isroot(dir) && coda_iscontrol(name, length))
		return -EPERM;

	error = venus_create(dir->i_sb, coda_i2f(dir), name, length, 
				0, mode, &newfid, &attrs);
	if (error)
		goto err_out;

	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		goto err_out;
	}

	/* invalidate the directory cnode's attributes */
	coda_dir_update_mtime(dir);
	d_instantiate(de, inode);
	return 0;
err_out:
	d_drop(de);
	return error;
}

int coda_permission(struct inode *inode, int mask)
{
	int error;

	if (mask & MAY_NOT_BLOCK)
		return -ECHILD;

	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 
	if (!mask)
		return 0;

	if ((mask & MAY_EXEC) && !execute_ok(inode))
		return -EACCES;

	if (coda_cache_check(inode, mask))
		return 0;

	error = venus_access(inode->i_sb, coda_i2f(inode), mask);
    
	if (!error)
		coda_cache_enter(inode, mask);

	return error;
}

/* access routines: lookup, readlink, permission */
static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struct nameidata *nd)
{
	struct super_block *sb = dir->i_sb;
	const char *name = entry->d_name.name;
	size_t length = entry->d_name.len;
	struct inode *inode;
	int type = 0;

	if (length > CODA_MAXNAMLEN) {
		printk(KERN_ERR "name too long: lookup, %s (%*s)\n",
		       coda_i2s(dir), (int)length, name);
		return ERR_PTR(-ENAMETOOLONG);
	}

	/* control object, create inode on the fly */
	if (coda_isroot(dir) && coda_iscontrol(name, length)) {
		inode = coda_cnode_makectl(sb);
		type = CODA_NOCACHE;
	} else {
		struct CodaFid fid = { { 0, } };
		int error = venus_lookup(sb, coda_i2f(dir), name, length,
				     &type, &fid);
		inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
	}

	if (!IS_ERR(inode) && (type & CODA_NOCACHE))
		coda_flag_inode(inode, C_VATTR | C_PURGE);

	if (inode == ERR_PTR(-ENOENT))
		inode = NULL;

	return d_splice_alias(inode, entry);
}

static int coda_symlink(struct inode *dir_inode, struct dentry *de,
			const char *symname)
{
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int symlen;
	int error;

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
		return -EPERM;

	symlen = strlen(symname);
	if (symlen > CODA_MAXPATHLEN)
		return -ENAMETOOLONG;

	d_drop(de);
	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
			      symname, symlen);

	
	if (!error)
		coda_dir_update_mtime(dir_inode);

	return error;
}

static int coda_symlink(struct inode *dir_inode, struct dentry *de,
			const char *symname)
{
        const char *name = de->d_name.name;
	int len = de->d_name.len;
	int symlen;
        int error=0;
        
	coda_vfs_stat.symlink++;

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
		return -EPERM;

	symlen = strlen(symname);
	if ( symlen > CODA_MAXPATHLEN )
                return -ENAMETOOLONG;

        CDEBUG(D_INODE, "symname: %s, length: %d\n", symname, symlen);

	/*
	 * This entry is now negative. Since we do not create
	 * an inode for the entry we have to drop it. 
	 */
	d_drop(de);
	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len, 
			      symname, symlen);

	/* mtime is no good anymore */
	if ( !error )
		coda_dir_changed(dir_inode, 0);

        CDEBUG(D_INODE, "in symlink result %d\n",error);
        return error;
}

int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
{
	struct file *host_file;
	struct inode *coda_inode = coda_file->f_path.dentry->d_inode;
	struct coda_file_info *cfi;
	int err;

	if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
	      S_ISLNK(coda_inode->i_mode)))
		return -EINVAL;

	err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
	if (err)
		return err;
	mutex_lock(&coda_inode->i_mutex);

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	err = vfs_fsync(host_file, datasync);
	if (!err && !datasync)
		err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	mutex_unlock(&coda_inode->i_mutex);

	return err;
}

int coda_permission(struct inode *inode, int mask)
{
        int error = 0;

	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 
	if (!mask)
		return 0; 

	if ((mask & MAY_EXEC) && !execute_ok(inode))
		return -EACCES;

	lock_kernel();

	if (coda_cache_check(inode, mask))
		goto out; 

        error = venus_access(inode->i_sb, coda_i2f(inode), mask);
    
	if (!error)
		coda_cache_enter(inode, mask);

 out:
	unlock_kernel();
	return error;
}

int coda_rmdir(struct inode *dir, struct dentry *de)
{
	const char *name = de->d_name.name;
	int len = de->d_name.len;
        int error;

	lock_kernel();
	coda_vfs_stat.rmdir++;

	if (!d_unhashed(de)) {
		unlock_kernel();
		return -EBUSY;
	}
	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);

        if ( error ) {
		unlock_kernel();
                return error;
        }

	coda_dir_changed(dir, -1);
	drop_nlink(de->d_inode);
	d_delete(de);
	unlock_kernel();

        return 0;
}