/* * mm/shmem_acl.c * * (C) 2005 Andreas Gruenbacher <agruen@suse.de> * * This file is released under the GPL. */#include <linux/fs.h>#include <linux/shmem_fs.h>#include <linux/xattr.h>#include <linux/generic_acl.h>/** * shmem_get_acl  -   generic_acl_operations->getacl() operation */static struct posix_acl *shmem_get_acl(struct inode *inode, int type){	struct posix_acl *acl = NULL;	spin_lock(&inode->i_lock);	switch(type) {		case ACL_TYPE_ACCESS:			acl = posix_acl_dup(SHMEM_I(inode)->i_acl);			break;		case ACL_TYPE_DEFAULT:			acl = posix_acl_dup(SHMEM_I(inode)->i_default_acl);			break;	}	spin_unlock(&inode->i_lock);	return acl;}/** * shmem_set_acl  -   generic_acl_operations->setacl() operation */static voidshmem_set_acl(struct inode *inode, int type, struct posix_acl *acl){	struct posix_acl *free = NULL;	spin_lock(&inode->i_lock);	switch(type) {		case ACL_TYPE_ACCESS:			free = SHMEM_I(inode)->i_acl;			SHMEM_I(inode)->i_acl = posix_acl_dup(acl);			break;		case ACL_TYPE_DEFAULT:			free = SHMEM_I(inode)->i_default_acl;			SHMEM_I(inode)->i_default_acl = posix_acl_dup(acl);			break;	}	spin_unlock(&inode->i_lock);	posix_acl_release(free);}struct generic_acl_operations shmem_acl_ops = {	.getacl = shmem_get_acl,	.setacl = shmem_set_acl,};/** * shmem_list_acl_access, shmem_get_acl_access, shmem_set_acl_access, * shmem_xattr_acl_access_handler  -  plumbing code to implement the * system.posix_acl_access xattr using the generic acl functions. */static size_tshmem_list_acl_access(struct inode *inode, char *list, size_t list_size,		      const char *name, size_t name_len){	return generic_acl_list(inode, &shmem_acl_ops, ACL_TYPE_ACCESS,				list, list_size);}static intshmem_get_acl_access(struct inode *inode, const char *name, void *buffer,		     size_t size){	if (strcmp(name, "") != 0)		return -EINVAL;	return generic_acl_get(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, buffer,			       size);}static intshmem_set_acl_access(struct inode *inode, const char *name, const void *value,		     size_t size, int flags){	if (strcmp(name, "") != 0)		return -EINVAL;	return generic_acl_set(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, value,			       size);}struct xattr_handler shmem_xattr_acl_access_handler = {	.prefix = POSIX_ACL_XATTR_ACCESS,	.list	= shmem_list_acl_access,	.get	= shmem_get_acl_access,	.set	= shmem_set_acl_access,};/** * shmem_list_acl_default, shmem_get_acl_default, shmem_set_acl_default, * shmem_xattr_acl_default_handler  -  plumbing code to implement the * system.posix_acl_default xattr using the generic acl functions. */static size_tshmem_list_acl_default(struct inode *inode, char *list, size_t list_size,		       const char *name, size_t name_len){	return generic_acl_list(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT,				list, list_size);}static intshmem_get_acl_default(struct inode *inode, const char *name, void *buffer,		      size_t size){	if (strcmp(name, "") != 0)		return -EINVAL;	return generic_acl_get(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, buffer,			       size);}static intshmem_set_acl_default(struct inode *inode, const char *name, const void *value,		      size_t size, int flags){	if (strcmp(name, "") != 0)		return -EINVAL;	return generic_acl_set(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, value,			       size);}struct xattr_handler shmem_xattr_acl_default_handler = {	.prefix = POSIX_ACL_XATTR_DEFAULT,	.list	= shmem_list_acl_default,	.get	= shmem_get_acl_default,	.set	= shmem_set_acl_default,};/** * shmem_acl_init  -  Inizialize the acl(s) of a new inode */intshmem_acl_init(struct inode *inode, struct inode *dir){	return generic_acl_init(inode, dir, &shmem_acl_ops);}/** * shmem_acl_destroy_inode  -  destroy acls hanging off the in-memory inode * * This is done before destroying the actual inode. */voidshmem_acl_destroy_inode(struct inode *inode){	if (SHMEM_I(inode)->i_acl)		posix_acl_release(SHMEM_I(inode)->i_acl);	SHMEM_I(inode)->i_acl = NULL;	if (SHMEM_I(inode)->i_default_acl)		posix_acl_release(SHMEM_I(inode)->i_default_acl);	SHMEM_I(inode)->i_default_acl = NULL;}/** * shmem_check_acl  -  check_acl() callback for generic_permission() */static intshmem_check_acl(struct inode *inode, int mask){	struct posix_acl *acl = shmem_get_acl(inode, ACL_TYPE_ACCESS);	if (acl) {		int error = posix_acl_permission(inode, acl, mask);		posix_acl_release(acl);		return error;	}	return -EAGAIN;}/** * shmem_permission  -  permission() inode operation */intshmem_permission(struct inode *inode, int mask){	return generic_permission(inode, mask, shmem_check_acl);}