X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=fd.c;h=9b6c6917232eb5063bb3acaad51a24ea53226389;hb=d9566a07057f68b0effd404e2da7817555f35383;hp=2e05313ea26ece1fd65315e80561fdd626f45fe1;hpb=9de1287d67c9562e9140c6dc7deb0c01c4e10cc0;p=paraslash.git

diff --git a/fd.c b/fd.c
index 2e05313e..9b6c6917 100644
--- a/fd.c
+++ b/fd.c
@@ -541,6 +541,22 @@ int mmap_full_file(const char *path, int open_mode, void **map,
 		goto out;
 	}
 	*size = file_status.st_size;
+	/*
+	 * If the file is empty, *size is zero and mmap() would return EINVAL
+	 * (Invalid argument). This error is common enough to spend an extra
+	 * error code which explicitly states the problem.
+	 */
+	ret = -E_EMPTY;
+	if (*size == 0)
+		goto out;
+	/*
+	 * If fd refers to a directory, mmap() returns ENODEV (No such device),
+	 * at least on Linux. "Is a directory" seems to be more to the point.
+	 */
+	ret = -ERRNO_TO_PARA_ERROR(EISDIR);
+	if (S_ISDIR(file_status.st_mode))
+		goto out;
+
 	ret = para_mmap(*size, mmap_prot, mmap_flags, fd, 0, map);
 out:
 	if (ret < 0 || !fd_ptr)