tree abe932c45768b11bd1cdd59922f5e30de1f60590
parent 31747eda41ef3c30c09c5c096b380bf54013746a
author Amir Goldstein <amir73il@gmail.com> 1510126786 +0200
committer Miklos Szeredi <mszeredi@redhat.com> 1516366473 +0100

ovl: fix failure to fsync lower dir

As a writable mount, it is not expected for overlayfs to return
EINVAL/EROFS for fsync, even if dir/file is not changed.

This commit fixes the case of fsync of directory, which is easier to
address, because overlayfs already implements fsync file operation for
directories.

The problem reported by Raphael is that new PostgreSQL 10.0 with a
database in overlayfs where lower layer in squashfs fails to start.
The failure is due to fsync error, when PostgreSQL does fsync on all
existing db directories on startup and a specific directory exists
lower layer with no changes.

Reported-by: Raphael Hertzog <raphael@ouaza.com>
Cc: <stable@vger.kernel.org> # v3.18
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Raphaël Hertzog <hertzog@debian.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>