4 files changed, 62 insertions, 40 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index c2a6b0894022..5c9d2d80ff70 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -505,6 +505,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
 	struct dentry *upper;
 	struct dentry *opaquedir = NULL;
 	int err;
+	int flags = 0;
 
 	if (WARN_ON(!workdir))
 		return -EROFS;
@@ -534,46 +535,39 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
 	if (err)
 		goto out_dput;
 
-	whiteout = ovl_whiteout(workdir, dentry);
-	err = PTR_ERR(whiteout);
-	if (IS_ERR(whiteout))
+	upper = lookup_one_len(dentry->d_name.name, upperdir,
+			       dentry->d_name.len);
+	err = PTR_ERR(upper);
+	if (IS_ERR(upper))
 		goto out_unlock;
 
-	upper = ovl_dentry_upper(dentry);
-	if (!upper) {
-		upper = lookup_one_len(dentry->d_name.name, upperdir,
-				       dentry->d_name.len);
-		err = PTR_ERR(upper);
-		if (IS_ERR(upper))
-			goto kill_whiteout;
-
-		err = ovl_do_rename(wdir, whiteout, udir, upper, 0);
-		dput(upper);
-		if (err)
-			goto kill_whiteout;
-	} else {
-		int flags = 0;
+	err = -ESTALE;
+	if ((opaquedir && upper != opaquedir) ||
+	    (!opaquedir && ovl_dentry_upper(dentry) &&
+	     upper != ovl_dentry_upper(dentry))) {
+		goto out_dput_upper;
+	}
 
-		if (opaquedir)
-			upper = opaquedir;
-		err = -ESTALE;
-		if (upper->d_parent != upperdir)
-			goto kill_whiteout;
+	whiteout = ovl_whiteout(workdir, dentry);
+	err = PTR_ERR(whiteout);
+	if (IS_ERR(whiteout))
+		goto out_dput_upper;
 
-		if (is_dir)
-			flags |= RENAME_EXCHANGE;
+	if (d_is_dir(upper))
+		flags = RENAME_EXCHANGE;
 
-		err = ovl_do_rename(wdir, whiteout, udir, upper, flags);
-		if (err)
-			goto kill_whiteout;
+	err = ovl_do_rename(wdir, whiteout, udir, upper, flags);
+	if (err)
+		goto kill_whiteout;
+	if (flags)
+		ovl_cleanup(wdir, upper);
 
-		if (is_dir)
-			ovl_cleanup(wdir, upper);
-	}
 	ovl_dentry_version_inc(dentry->d_parent);
 out_d_drop:
 	d_drop(dentry);
 	dput(whiteout);
+out_dput_upper:
+	dput(upper);
 out_unlock:
 	unlock_rename(workdir, upperdir);
 out_dput:
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index e08cd94d7b26..d554e86abbe3 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -59,16 +59,40 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 	if (err)
 		goto out;
 
+	if (attr->ia_valid & ATTR_SIZE) {
+		struct inode *realinode = d_inode(ovl_dentry_real(dentry));
+
+		err = -ETXTBSY;
+		if (atomic_read(&realinode->i_writecount) < 0)
+			goto out_drop_write;
+	}
+
 	err = ovl_copy_up(dentry);
 	if (!err) {
+		struct inode *winode = NULL;
+
 		upperdentry = ovl_dentry_upper(dentry);
 
+		if (attr->ia_valid & ATTR_SIZE) {
+			winode = d_inode(upperdentry);
+			err = get_write_access(winode);
+			if (err)
+				goto out_drop_write;
+		}
+
+		if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
+			attr->ia_valid &= ~ATTR_MODE;
+
 		inode_lock(upperdentry->d_inode);
 		err = notify_change(upperdentry, attr, NULL);
 		if (!err)
 			ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
 		inode_unlock(upperdentry->d_inode);
+
+		if (winode)
+			put_write_access(winode);
 	}
+out_drop_write:
 	ovl_drop_write(dentry);
 out:
 	return err;
@@ -121,16 +145,18 @@ int ovl_permission(struct inode *inode, int mask)
 
 		err = vfs_getattr(&realpath, &stat);
 		if (err)
-			return err;
+			goto out_dput;
 
+		err = -ESTALE;
 		if ((stat.mode ^ inode->i_mode) & S_IFMT)
-			return -ESTALE;
+			goto out_dput;
 
 		inode->i_mode = stat.mode;
 		inode->i_uid = stat.uid;
 		inode->i_gid = stat.gid;
 
-		return generic_permission(inode, mask);
+		err = generic_permission(inode, mask);
+		goto out_dput;
 	}
 
 	/* Careful in RCU walk mode */
@@ -376,12 +402,11 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
 	if (!inode)
 		return NULL;
 
-	mode &= S_IFMT;
-
 	inode->i_ino = get_next_ino();
 	inode->i_mode = mode;
 	inode->i_flags |= S_NOATIME | S_NOCMTIME;
 
+	mode &= S_IFMT;
 	switch (mode) {
 	case S_IFDIR:
 		inode->i_private = oe;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 6b9fd25c5ad4..0d3f2ad45708 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -187,6 +187,7 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to)
 {
 	to->i_uid = from->i_uid;
 	to->i_gid = from->i_gid;
+	to->i_mode = from->i_mode;
 }
 
 /* dir.c */
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 035c176edf00..5e254b3a8c56 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1090,11 +1090,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 			if (err < 0)
 				goto out_put_workdir;
 
-			if (!err) {
-				pr_err("overlayfs: upper fs needs to support d_type.\n");
-				err = -EINVAL;
-				goto out_put_workdir;
-			}
+			/*
+			 * We allowed this configuration and don't want to
+			 * break users over kernel upgrade. So warn instead
+			 * of erroring out.
+			 */
+			if (!err)
+				pr_warn("overlayfs: upper fs needs to support d_type.\n");
 		}
 	}