Apparmor: mediated_filesystem() should use dentry->d_sb not inode->i_sb

mediated_filesystem() should use dentry->d_sb not dentry->d_inode->i_sb and
should avoid file_inode() also since it is really dealing with the path.

Signed-off-by: David Howells <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

security/apparmor/include/apparmor.h

···
 	return aa_dfa_next(dfa, start, 0);
 }
 
-static inline bool mediated_filesystem(struct inode *inode)
+static inline bool mediated_filesystem(struct dentry *dentry)
 {
-	return !(inode->i_sb->s_flags & MS_NOUSER);
+	return !(dentry->d_sb->s_flags & MS_NOUSER);
 }
 
 #endif /* __APPARMOR_H */

security/apparmor/lsm.c

···
 	struct inode *inode = dentry->d_inode;
 	struct path_cond cond = { };
 
-	if (!inode || !dir->mnt || !mediated_filesystem(inode))
+	if (!inode || !dir->mnt || !mediated_filesystem(dentry))
 		return 0;
 
 	cond.uid = inode->i_uid;
···
 {
 	struct path_cond cond = { current_fsuid(), mode };
 
-	if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
+	if (!dir->mnt || !mediated_filesystem(dir->dentry))
 		return 0;
 
 	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
···
 				  path->dentry->d_inode->i_mode
 	};
 
-	if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
+	if (!path->mnt || !mediated_filesystem(path->dentry))
 		return 0;
 
 	return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
···
 	struct aa_profile *profile;
 	int error = 0;
 
-	if (!mediated_filesystem(old_dentry->d_inode))
+	if (!mediated_filesystem(old_dentry))
 		return 0;
 
 	profile = aa_current_profile();
···
 	struct aa_profile *profile;
 	int error = 0;
 
-	if (!mediated_filesystem(old_dentry->d_inode))
+	if (!mediated_filesystem(old_dentry))
 		return 0;
 
 	profile = aa_current_profile();
···
 
 static int apparmor_path_chmod(struct path *path, umode_t mode)
 {
-	if (!mediated_filesystem(path->dentry->d_inode))
+	if (!mediated_filesystem(path->dentry))
 		return 0;
 
 	return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
···
 				   path->dentry->d_inode->i_mode
 	};
 
-	if (!mediated_filesystem(path->dentry->d_inode))
+	if (!mediated_filesystem(path->dentry))
 		return 0;
 
 	return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
···
 
 static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 {
-	if (!mediated_filesystem(dentry->d_inode))
+	if (!mediated_filesystem(dentry))
 		return 0;
 
 	return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
···
 	struct aa_profile *profile;
 	int error = 0;
 
-	if (!mediated_filesystem(file_inode(file)))
+	if (!mediated_filesystem(file->f_path.dentry))
 		return 0;
 
 	/* If in exec, permission is handled by bprm hooks.
···
 	BUG_ON(!fprofile);
 
 	if (!file->f_path.mnt ||
-	    !mediated_filesystem(file_inode(file)))
+	    !mediated_filesystem(file->f_path.dentry))
 		return 0;
 
 	profile = __aa_current_profile();