From 814a7e034516b8a917c7313d9800b45c9f5193df Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 1 Feb 2021 17:12:12 +0100
Subject: [PATCH] fs-util: add API for fsync()ing parent dir of path

---
 src/basic/fs-util.c | 24 ++++++++++++++++++++++++
 src/basic/fs-util.h |  1 +
 2 files changed, 25 insertions(+)

diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index 127f709cd9c..62c7954c843 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -1484,6 +1484,30 @@ int fsync_path_at(int at_fd, const char *path) {
         return 0;
 }
 
+int fsync_parent_at(int at_fd, const char *path) {
+        _cleanup_close_ int opened_fd = -1;
+
+        if (isempty(path)) {
+                if (at_fd != AT_FDCWD)
+                        return fsync_directory_of_file(at_fd);
+
+                opened_fd = open("..", O_RDONLY|O_DIRECTORY|O_CLOEXEC);
+                if (opened_fd < 0)
+                        return -errno;
+
+                if (fsync(opened_fd) < 0)
+                        return -errno;
+
+                return 0;
+        }
+
+        opened_fd = openat(at_fd, path, O_PATH|O_CLOEXEC|O_NOFOLLOW);
+        if (opened_fd < 0)
+                return -errno;
+
+        return fsync_directory_of_file(opened_fd);
+}
+
 int syncfs_path(int atfd, const char *path) {
         _cleanup_close_ int fd = -1;
 
diff --git a/src/basic/fs-util.h b/src/basic/fs-util.h
index 7f15b558ca8..c4ab98dbb4e 100644
--- a/src/basic/fs-util.h
+++ b/src/basic/fs-util.h
@@ -140,6 +140,7 @@ int unlinkat_deallocate(int fd, const char *name, UnlinkDeallocateFlags flags);
 int fsync_directory_of_file(int fd);
 int fsync_full(int fd);
 int fsync_path_at(int at_fd, const char *path);
+int fsync_parent_at(int at_fd, const char *path);
 
 int syncfs_path(int atfd, const char *path);