bfd: Don't flush read-only images

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

bfd.c

@@ -86,13 +86,14 @@ static void buf_put(struct xbuf *xb)
 	xb->data = NULL;
 }
 
-int bfdopen(struct bfd *f)
+int bfdopen(struct bfd *f, int mode)
 {
 	if (buf_get(&f->b)) {
 		close(f->fd);
 		return -1;
 	}
 
+	f->mode = mode;
 	return 0;
 }
 
@@ -107,13 +108,7 @@ int bfd_flush_images(void)
 void bclose(struct bfd *f)
 {
 	if (bfd_buffered(f)) {
-		/*
-		 * FIXME -- when we bread from images we don't
-		 * need to flush. This call doesn't fail simply
-		 * becase we read _all_ data from them and the
-		 * b->sz would be 0 by the time we close them.
-		 */
-		if (bflush(f) < 0) {
+		if ((f->mode != O_RDONLY) && bflush(f) < 0) {
 			/*
 			 * This is to propagate error up. It's
 			 * hardly possible by returning and

image.c

@@ -235,7 +235,7 @@ struct cr_img *open_image_at(int dfd, int type, unsigned long flags, ...)
 	img->_x.fd = ret;
 	if (oflags & O_NOBUF)
 		bfd_setraw(&img->_x);
-	else if (bfdopen(&img->_x))
+	else if (bfdopen(&img->_x, flags))
 		goto err;
 
 	if (imgset_template[type].magic == RAW_IMAGE_MAGIC)

include/bfd.h

@@ -13,6 +13,7 @@ struct xbuf {
 
 struct bfd {
 	int fd;
+	int mode;
 	struct xbuf b;
 };
 
@@ -26,7 +27,7 @@ static inline void bfd_setraw(struct bfd *b)
 	b->b.mem = NULL;
 }
 
-int bfdopen(struct bfd *f);
+int bfdopen(struct bfd *f, int mode);
 void bclose(struct bfd *f);
 char *breadline(struct bfd *f);
 int bwrite(struct bfd *f, const void *buf, int sz);

proc_parse.c

@@ -313,7 +313,7 @@ int parse_smaps(pid_t pid, struct vm_area_list *vma_area_list, bool use_map_file
 	if (f.fd < 0)
 		goto err_n;
 
-	if (bfdopen(&f))
+	if (bfdopen(&f, O_RDONLY))
 		goto err_n;
 
 	if (use_map_files) {
@@ -1158,7 +1158,7 @@ static int parse_fdinfo_pid_s(int pid, int fd, int type,
 		return -1;
 	}
 
-	if (bfdopen(&f))
+	if (bfdopen(&f, O_RDONLY))
 		return -1;
 
 	while (1) {
@@ -1613,7 +1613,7 @@ int parse_posix_timers(pid_t pid, struct proc_posix_timers_stat *args)
 		return -1;
 	}
 
-	if (bfdopen(&f))
+	if (bfdopen(&f, O_RDONLY))
 		return -1;
 
 	while (1) {