/*
* Initialize the ACLs of a new inode. Called from ext4_new_inode.
*
* dir->i_mutex: down
* inode->i_mutex: up (access to inode is still exclusive)
*/
int
ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
{
struct posix_acl *acl = NULL;
int error = 0;
if (!S_ISLNK(inode->i_mode)) {
if (test_opt(dir->i_sb, POSIX_ACL)) {
acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
if (!acl)
inode->i_mode &= ~current_umask();
}
if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
if (S_ISDIR(inode->i_mode)) {
error = ext4_set_acl(handle, inode,
ACL_TYPE_DEFAULT, acl);
if (error)
goto cleanup;
}
error = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
if (error < 0)
return error;
if (error > 0) {
/* This is an extended ACL */
error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
}
}
cleanup:
posix_acl_release(acl);
return error;
}
int
ext4_check_acl(struct inode *inode, int mask)
{
struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
int error = posix_acl_permission(inode, acl, mask);
posix_acl_release(acl);
return error;
}
return -EAGAIN;
}
/*
* Does chmod for an inode that may have an Access Control List. The
* inode->i_mode field must be updated to the desired value by the caller
* before calling this function.
* Returns 0 on success, or a negative error number.
*
* We change the ACL rather than storing some ACL entries in the file
* mode permission bits (which would be more efficient), because that
* would break once additional permissions (like ACL_APPEND, ACL_DELETE
* for directories) are added. There are no more bits available in the
* file mode.
*
* inode->i_mutex: down
*/
int
ext4_acl_chmod(struct inode *inode)
{
struct posix_acl *acl, *clone;
int error;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (!test_opt(inode->i_sb, POSIX_ACL))
return 0;
acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl) || !acl)
return PTR_ERR(acl);
clone = posix_acl_clone(acl, GFP_KERNEL);
posix_acl_release(acl);
if (!clone)
return -ENOMEM;
error = posix_acl_chmod_masq(clone, inode->i_mode);
if (!error) {
handle_t *handle;
int retries = 0;
retry:
handle = ext4_journal_start(inode,
EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
if (IS_ERR(handle)) {
error = PTR_ERR(handle);
ext4_std_error(inode->i_sb, error);
goto out;
}
error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
ext4_journal_stop(handle);
if (error == -ENOSPC &&
ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry;
}
out:
posix_acl_release(clone);
return error;
}
static int
ext4_xattr_get_acl(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;
if (!test_opt(dentry->d_sb, POSIX_ACL))
return -EOPNOTSUPP;
acl = ext4_get_acl(dentry->d_inode, type);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl == NULL)
return -ENODATA;
error = posix_acl_to_xattr(acl, buffer, size);
posix_acl_release(acl);
return error;
}