/* * (C) 2005 Andreas Gruenbacher <agruen@suse.de> * * This file is released under the GPL. * * Generic ACL support for in-memory filesystems. */ #include <linux/sched.h>#include <linux/gfp.h>#include <linux/fs.h>#include <linux/generic_acl.h>#include <linux/posix_acl.h>#include <linux/posix_acl_xattr.h>  static size_tgeneric_acl_list(struct dentry *dentry, char *list, size_t list_size,		const char *name, size_t name_len, int type){	struct posix_acl *acl;	const char *xname;	size_t size; 	acl = get_cached_acl(dentry->d_inode, type);	if (!acl)		return 0;	posix_acl_release(acl); 	switch (type) {	case ACL_TYPE_ACCESS:		xname = POSIX_ACL_XATTR_ACCESS;		break;	case ACL_TYPE_DEFAULT:		xname = POSIX_ACL_XATTR_DEFAULT;		break;	default:		return 0;	}	size = strlen(xname) + 1;	if (list && size <= list_size)		memcpy(list, xname, size);	return size;} static intgeneric_acl_get(struct dentry *dentry, const char *name, void *buffer,		     size_t size, int type){	struct posix_acl *acl;	int error; 	if (strcmp(name, "") != 0)		return -EINVAL; 	acl = get_cached_acl(dentry->d_inode, type);	if (!acl)		return -ENODATA;	error = posix_acl_to_xattr(acl, buffer, size);	posix_acl_release(acl); 	return error;} static intgeneric_acl_set(struct dentry *dentry, const char *name, const void *value,		     size_t size, int flags, int type){	struct inode *inode = dentry->d_inode;	struct posix_acl *acl = NULL;	int error; 	if (strcmp(name, "") != 0)		return -EINVAL;	if (S_ISLNK(inode->i_mode))		return -EOPNOTSUPP;	if (!inode_owner_or_capable(inode))		return -EPERM;	if (value) {		acl = posix_acl_from_xattr(value, size);		if (IS_ERR(acl))			return PTR_ERR(acl);	}	if (acl) {		error = posix_acl_valid(acl);		if (error)			goto failed;		switch (type) {		case ACL_TYPE_ACCESS:			error = posix_acl_equiv_mode(acl, &inode->i_mode);			if (error < 0)				goto failed;			inode->i_ctime = CURRENT_TIME;			if (error == 0) {				posix_acl_release(acl);				acl = NULL;			}			break;		case ACL_TYPE_DEFAULT:			if (!S_ISDIR(inode->i_mode)) {				error = -EINVAL;				goto failed;			}			break;		}	}	set_cached_acl(inode, type, acl);	error = 0;failed:	posix_acl_release(acl);	return error;} /** * generic_acl_init  -  Take care of acl inheritance at @inode create time * * Files created inside a directory with a default ACL inherit the * directory's default ACL. */intgeneric_acl_init(struct inode *inode, struct inode *dir){	struct posix_acl *acl = NULL;	int error; 	if (!S_ISLNK(inode->i_mode))		acl = get_cached_acl(dir, ACL_TYPE_DEFAULT);	if (acl) {		if (S_ISDIR(inode->i_mode))			set_cached_acl(inode, ACL_TYPE_DEFAULT, acl);		error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);		if (error < 0)			return error;		if (error > 0)			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);	} else {		inode->i_mode &= ~current_umask();	}	error = 0; 	posix_acl_release(acl);	return error;} /** * generic_acl_chmod  -  change the access acl of @inode upon chmod() * * A chmod also changes the permissions of the owner, group/mask, and * other ACL entries. */intgeneric_acl_chmod(struct inode *inode){	struct posix_acl *acl;	int error = 0; 	if (S_ISLNK(inode->i_mode))		return -EOPNOTSUPP;	acl = get_cached_acl(inode, ACL_TYPE_ACCESS);	if (acl) {		error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);		if (error)			return error;		set_cached_acl(inode, ACL_TYPE_ACCESS, acl);		posix_acl_release(acl);	}	return error;} const struct xattr_handler generic_acl_access_handler = {	.prefix = POSIX_ACL_XATTR_ACCESS,	.flags	= ACL_TYPE_ACCESS,	.list	= generic_acl_list,	.get	= generic_acl_get,	.set	= generic_acl_set,}; const struct xattr_handler generic_acl_default_handler = {	.prefix = POSIX_ACL_XATTR_DEFAULT,	.flags	= ACL_TYPE_DEFAULT,	.list	= generic_acl_list,	.get	= generic_acl_get,	.set	= generic_acl_set,};