DO NOT MERGE ANYWHERE Use synchronous writes when setting up BCB.
Commit [1] made similar changes into AOSP code, but it requires multiple
CLs to cherry-pick into cw-e branch. So we make a separate CL to fix the
issue.
[1] commit bd82b27341336f0b375c3bc2a7bf48b2ccc20c1f
Bug: 27247370
Change-Id: Id5c08a6a29284353f891cdbaa224feee891f3807
diff --git a/bootloader.cpp b/bootloader.cpp
index 600d238..1c20979 100644
--- a/bootloader.cpp
+++ b/bootloader.cpp
@@ -21,9 +21,12 @@
#include "roots.h"
#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
+#include <sys/types.h>
#include <unistd.h>
static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
@@ -185,18 +188,30 @@
static int set_bootloader_message_block(const struct bootloader_message *in,
const Volume* v) {
wait_for_device(v->blk_device);
- FILE* f = fopen(v->blk_device, "wb");
- if (f == NULL) {
+ int fd = open(v->blk_device, O_WRONLY | O_SYNC);
+ if (fd == -1) {
LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
- int count = fwrite(in, sizeof(*in), 1, f);
- if (count != 1) {
- LOGE("Failed writing %s\n(%s)\n", v->blk_device, strerror(errno));
+ size_t written = 0;
+ const uint8_t* start = reinterpret_cast<const uint8_t*>(in);
+ size_t total = sizeof(*in);
+ while (written < total) {
+ ssize_t wrote = TEMP_FAILURE_RETRY(write(fd, start + written, total - written));
+ if (wrote == -1) {
+ LOGE("failed to write %" PRId64 " bytes: %s\n",
+ static_cast<off64_t>(written), strerror(errno));
+ return -1;
+ }
+ written += wrote;
+ }
+
+ if (fsync(fd) == -1) {
+ LOGE("failed to fsync \"%s\": %s\n", v->blk_device, strerror(errno));
return -1;
}
- if (fclose(f) != 0) {
- LOGE("Failed closing %s\n(%s)\n", v->blk_device, strerror(errno));
+ if (close(fd) == -1) {
+ LOGE("failed to close %s: %s\n", v->blk_device, strerror(errno));
return -1;
}
return 0;