rootless: provide workaround for missing renameat2
on RHEL 7.7 renameat2 is not implemented for s390x, provide a
workaround.
Closes:
@@ -27,9 +27,13 @@ int renameat2 (int olddirfd, const char *oldpath, int newdirfd, const char *newp
# ifdef SYS_renameat2
return (int) syscall (SYS_renameat2, olddirfd, oldpath, newdirfd, newpath, flags);
# else
- /* no way to implement it atomically. */
- errno = ENOSYS;
- return -1;
+ /* This might be an issue if another process is trying to read the file while it is empty. */
+ int fd = open (newpath, O_EXCL|O_CREAT, 0700);
+ if (fd < 0)
+ return fd;
+ close (fd);
+ /* We are sure we created the file, let's overwrite it. */
+ return rename (oldpath, newpath);
# endif
}
#endif
