ovl: pass ofs to creation operations

Pass down struct ovl_fs to all creation helpers so we can ultimately
retrieve the relevant upper mount and take the mount's idmapping into
account when creating new filesystem objects. This is needed to support
idmapped base layers with overlay.

Cc: <linux-unionfs@vger.kernel.org>
Tested-by: Giuseppe Scrivano <gscrivan@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

1 files changed, 45 insertions, 40 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 8bf800c5796a..6245016c4a08 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -23,15 +23,15 @@ MODULE_PARM_DESC(redirect_max,
 
 static int ovl_set_redirect(struct dentry *dentry, bool samedir);
 
-int ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
+int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry)
 {
 	int err;
 
 	dget(wdentry);
 	if (d_is_dir(wdentry))
-		err = ovl_do_rmdir(wdir, wdentry);
+		err = ovl_do_rmdir(ofs, wdir, wdentry);
 	else
-		err = ovl_do_unlink(wdir, wdentry);
+		err = ovl_do_unlink(ofs, wdir, wdentry);
 	dput(wdentry);
 
 	if (err) {
@@ -42,7 +42,7 @@ int ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
 	return err;
 }
 
-struct dentry *ovl_lookup_temp(struct dentry *workdir)
+struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir)
 {
 	struct dentry *temp;
 	char name[20];
@@ -70,11 +70,11 @@ static struct dentry *ovl_whiteout(struct ovl_fs *ofs)
 	struct inode *wdir = workdir->d_inode;
 
 	if (!ofs->whiteout) {
-		whiteout = ovl_lookup_temp(workdir);
+		whiteout = ovl_lookup_temp(ofs, workdir);
 		if (IS_ERR(whiteout))
 			goto out;
 
-		err = ovl_do_whiteout(wdir, whiteout);
+		err = ovl_do_whiteout(ofs, wdir, whiteout);
 		if (err) {
 			dput(whiteout);
 			whiteout = ERR_PTR(err);
@@ -84,11 +84,11 @@ static struct dentry *ovl_whiteout(struct ovl_fs *ofs)
 	}
 
 	if (ofs->share_whiteout) {
-		whiteout = ovl_lookup_temp(workdir);
+		whiteout = ovl_lookup_temp(ofs, workdir);
 		if (IS_ERR(whiteout))
 			goto out;
 
-		err = ovl_do_link(ofs->whiteout, wdir, whiteout);
+		err = ovl_do_link(ofs, ofs->whiteout, wdir, whiteout);
 		if (!err)
 			goto out;
 
@@ -122,27 +122,28 @@ int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
 	if (d_is_dir(dentry))
 		flags = RENAME_EXCHANGE;
 
-	err = ovl_do_rename(wdir, whiteout, dir, dentry, flags);
+	err = ovl_do_rename(ofs, wdir, whiteout, dir, dentry, flags);
 	if (err)
 		goto kill_whiteout;
 	if (flags)
-		ovl_cleanup(wdir, dentry);
+		ovl_cleanup(ofs, wdir, dentry);
 
 out:
 	dput(whiteout);
 	return err;
 
 kill_whiteout:
-	ovl_cleanup(wdir, whiteout);
+	ovl_cleanup(ofs, wdir, whiteout);
 	goto out;
 }
 
-int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry, umode_t mode)
+int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
+		   struct dentry **newdentry, umode_t mode)
 {
 	int err;
 	struct dentry *d, *dentry = *newdentry;
 
-	err = ovl_do_mkdir(dir, dentry, mode);
+	err = ovl_do_mkdir(ofs, dir, dentry, mode);
 	if (err)
 		return err;
 
@@ -167,8 +168,8 @@ int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry, umode_t mode)
 	return 0;
 }
 
-struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
-			       struct ovl_cattr *attr)
+struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
+			       struct dentry *newdentry, struct ovl_cattr *attr)
 {
 	int err;
 
@@ -180,28 +181,28 @@ struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
 		goto out;
 
 	if (attr->hardlink) {
-		err = ovl_do_link(attr->hardlink, dir, newdentry);
+		err = ovl_do_link(ofs, attr->hardlink, dir, newdentry);
 	} else {
 		switch (attr->mode & S_IFMT) {
 		case S_IFREG:
-			err = ovl_do_create(dir, newdentry, attr->mode);
+			err = ovl_do_create(ofs, dir, newdentry, attr->mode);
 			break;
 
 		case S_IFDIR:
 			/* mkdir is special... */
-			err =  ovl_mkdir_real(dir, &newdentry, attr->mode);
+			err =  ovl_mkdir_real(ofs, dir, &newdentry, attr->mode);
 			break;
 
 		case S_IFCHR:
 		case S_IFBLK:
 		case S_IFIFO:
 		case S_IFSOCK:
-			err = ovl_do_mknod(dir, newdentry, attr->mode,
+			err = ovl_do_mknod(ofs, dir, newdentry, attr->mode,
 					   attr->rdev);
 			break;
 
 		case S_IFLNK:
-			err = ovl_do_symlink(dir, newdentry, attr->link);
+			err = ovl_do_symlink(ofs, dir, newdentry, attr->link);
 			break;
 
 		default:
@@ -223,10 +224,11 @@ out:
 	return newdentry;
 }
 
-struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr)
+struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir,
+			       struct ovl_cattr *attr)
 {
-	return ovl_create_real(d_inode(workdir), ovl_lookup_temp(workdir),
-			       attr);
+	return ovl_create_real(ofs, d_inode(workdir),
+			       ovl_lookup_temp(ofs, workdir), attr);
 }
 
 static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,
@@ -330,7 +332,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
 		attr->mode &= ~current_umask();
 
 	inode_lock_nested(udir, I_MUTEX_PARENT);
-	newdentry = ovl_create_real(udir,
+	newdentry = ovl_create_real(ofs, udir,
 				    lookup_one_len(dentry->d_name.name,
 						   upperdir,
 						   dentry->d_name.len),
@@ -353,7 +355,7 @@ out_unlock:
 	return err;
 
 out_cleanup:
-	ovl_cleanup(udir, newdentry);
+	ovl_cleanup(ofs, udir, newdentry);
 	dput(newdentry);
 	goto out_unlock;
 }
@@ -361,6 +363,7 @@ out_cleanup:
 static struct dentry *ovl_clear_empty(struct dentry *dentry,
 				      struct list_head *list)
 {
+	struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
 	struct dentry *workdir = ovl_workdir(dentry);
 	struct inode *wdir = workdir->d_inode;
 	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
@@ -391,7 +394,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
 	if (upper->d_parent->d_inode != udir)
 		goto out_unlock;
 
-	opaquedir = ovl_create_temp(workdir, OVL_CATTR(stat.mode));
+	opaquedir = ovl_create_temp(ofs, workdir, OVL_CATTR(stat.mode));
 	err = PTR_ERR(opaquedir);
 	if (IS_ERR(opaquedir))
 		goto out_unlock;
@@ -410,12 +413,12 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
 	if (err)
 		goto out_cleanup;
 
-	err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
+	err = ovl_do_rename(ofs, wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
 	if (err)
 		goto out_cleanup;
 
-	ovl_cleanup_whiteouts(upper, list);
-	ovl_cleanup(wdir, upper);
+	ovl_cleanup_whiteouts(ofs, upper, list);
+	ovl_cleanup(ofs, wdir, upper);
 	unlock_rename(workdir, upperdir);
 
 	/* dentry's upper doesn't match now, get rid of it */
@@ -424,7 +427,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
 	return opaquedir;
 
 out_cleanup:
-	ovl_cleanup(wdir, opaquedir);
+	ovl_cleanup(ofs, wdir, opaquedir);
 	dput(opaquedir);
 out_unlock:
 	unlock_rename(workdir, upperdir);
@@ -495,7 +498,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
 	if (d_is_negative(upper) || !IS_WHITEOUT(d_inode(upper)))
 		goto out_dput;
 
-	newdentry = ovl_create_temp(workdir, cattr);
+	newdentry = ovl_create_temp(ofs, workdir, cattr);
 	err = PTR_ERR(newdentry);
 	if (IS_ERR(newdentry))
 		goto out_dput;
@@ -533,20 +536,20 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
 		if (err)
 			goto out_cleanup;
 
-		err = ovl_do_rename(wdir, newdentry, udir, upper,
+		err = ovl_do_rename(ofs, wdir, newdentry, udir, upper,
 				    RENAME_EXCHANGE);
 		if (err)
 			goto out_cleanup;
 
-		ovl_cleanup(wdir, upper);
+		ovl_cleanup(ofs, wdir, upper);
 	} else {
-		err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
+		err = ovl_do_rename(ofs, wdir, newdentry, udir, upper, 0);
 		if (err)
 			goto out_cleanup;
 	}
 	err = ovl_instantiate(dentry, inode, newdentry, hardlink);
 	if (err) {
-		ovl_cleanup(udir, newdentry);
+		ovl_cleanup(ofs, udir, newdentry);
 		dput(newdentry);
 	}
 out_dput:
@@ -561,7 +564,7 @@ out:
 	return err;
 
 out_cleanup:
-	ovl_cleanup(wdir, newdentry);
+	ovl_cleanup(ofs, wdir, newdentry);
 	dput(newdentry);
 	goto out_dput;
 }
@@ -801,6 +804,7 @@ out:
 static int ovl_remove_upper(struct dentry *dentry, bool is_dir,
 			    struct list_head *list)
 {
+	struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
 	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
 	struct inode *dir = upperdir->d_inode;
 	struct dentry *upper;
@@ -827,9 +831,9 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir,
 		goto out_dput_upper;
 
 	if (is_dir)
-		err = vfs_rmdir(&init_user_ns, dir, upper);
+		err = ovl_do_rmdir(ofs, dir, upper);
 	else
-		err = vfs_unlink(&init_user_ns, dir, upper, NULL);
+		err = ovl_do_unlink(ofs, dir, upper);
 	ovl_dir_modified(dentry->d_parent, ovl_type_origin(dentry));
 
 	/*
@@ -1096,6 +1100,7 @@ static int ovl_rename(struct user_namespace *mnt_userns, struct inode *olddir,
 	bool samedir = olddir == newdir;
 	struct dentry *opaquedir = NULL;
 	const struct cred *old_cred = NULL;
+	struct ovl_fs *ofs = OVL_FS(old->d_sb);
 	LIST_HEAD(list);
 
 	err = -EINVAL;
@@ -1252,13 +1257,13 @@ static int ovl_rename(struct user_namespace *mnt_userns, struct inode *olddir,
 	if (err)
 		goto out_dput;
 
-	err = ovl_do_rename(old_upperdir->d_inode, olddentry,
+	err = ovl_do_rename(ofs, old_upperdir->d_inode, olddentry,
 			    new_upperdir->d_inode, newdentry, flags);
 	if (err)
 		goto out_dput;
 
 	if (cleanup_whiteout)
-		ovl_cleanup(old_upperdir->d_inode, newdentry);
+		ovl_cleanup(ofs, old_upperdir->d_inode, newdentry);
 
 	if (overwrite && d_inode(new)) {
 		if (new_is_dir)