Instrument pwrite() failure.
This will shed more light on the circumstances in which
DeltaPerformerTest.RunAsRootSmallImageTest is failing.
BUG=chromium-os:31077
TEST=Builds and passes unit tests
Change-Id: I9b97191b62ef6cf3b39bdb68fa40d758b0632283
Reviewed-on: https://gerrit.chromium.org/gerrit/27185
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Ready: Gilad Arnold <garnold@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
diff --git a/utils.cc b/utils.cc
index f4b3b24..9cb8053 100644
--- a/utils.cc
+++ b/utils.cc
@@ -105,10 +105,18 @@
bool PWriteAll(int fd, const void* buf, size_t count, off_t offset) {
const char* c_buf = static_cast<const char*>(buf);
- ssize_t bytes_written = 0;
- while (bytes_written < static_cast<ssize_t>(count)) {
+ size_t bytes_written = 0;
+ int num_attempts = 0;
+ while (bytes_written < count) {
+ num_attempts++;
ssize_t rc = pwrite(fd, c_buf + bytes_written, count - bytes_written,
offset + bytes_written);
+ // TODO(garnold) for debugging failure in chromium-os:31077; to be removed.
+ if (rc < 0) {
+ PLOG(ERROR) << "pwrite error; num_attempts=" << num_attempts
+ << " bytes_written=" << bytes_written
+ << " count=" << count << " offset=" << offset;
+ }
TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
bytes_written += rc;
}