X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Fio.c;h=d422d9632618fd47653878cd904a90b15645e878;hp=4166cd4c67caf0475684fc03a0e9de86e714500e;hb=6b7c3c840eafbec211b9f58751c5ff754302a68e;hpb=6e3d9e8a66bf8b45150500f176452ee8e9ee9927

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 4166cd4c..d422d963 100644
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -42,16 +42,23 @@ void tdb_munmap(struct tdb_file *file)
 
 void tdb_mmap(struct tdb_context *tdb)
 {
+	int mmap_flags;
+
 	if (tdb->flags & TDB_INTERNAL)
 		return;
 
 	if (tdb->flags & TDB_NOMMAP)
 		return;
 
+	if ((tdb->open_flags & O_ACCMODE) == O_RDONLY)
+		mmap_flags = PROT_READ;
+	else
+		mmap_flags = PROT_READ | PROT_WRITE;
+
 	/* size_t can be smaller than off_t. */
 	if ((size_t)tdb->file->map_size == tdb->file->map_size) {
 		tdb->file->map_ptr = mmap(NULL, tdb->file->map_size,
-					  tdb->mmap_flags,
+					  mmap_flags,
 					  MAP_SHARED, tdb->file->fd, 0);
 	} else
 		tdb->file->map_ptr = MAP_FAILED;