fs: implement pushd/popd chdir wrappers

We don't have dirfd's, so running operations relative to the current
working directory always involves some allocation/freeing boilerplate.

Add pushd/popd helpers to move the boilerplate out of the callsites.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20220108171555.588426-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/unistd.h b/include/unistd.h
index 06ce355809..f7fe737d00 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -20,6 +20,8 @@ int rmdir (const char *pathname);
 int symlink(const char *pathname, const char *newpath);
 int readlink(const char *path, char *buf, size_t bufsiz);
 int chdir(const char *pathname);
+char *pushd(const char *dir);
+int popd(char *dir);
 const char *getcwd(void);
 int ftruncate(int fd, loff_t length);