Make write() write all its data even if it takes time

This commit is contained in:
benrubson 2017-08-11 07:51:21 +02:00
parent 8e13120b18
commit acbeb64765

View File

@ -203,10 +203,10 @@ ssize_t RawFileIO::read(const IORequest &req) const {
rAssert(fd >= 0); rAssert(fd >= 0);
ssize_t readSize = pread(fd, req.data, req.dataLen, req.offset); ssize_t readSize = pread(fd, req.data, req.dataLen, req.offset);
int eno = errno;
errno = 0; //just to be sure error seen in integration tests really comes from the function rc.
if (readSize < 0) { if (readSize < 0) {
int eno = errno;
errno = 0; //just to be sure error seen in integration tests really comes from the function rc.
RLOG(WARNING) << "read failed at offset " << req.offset << " for " RLOG(WARNING) << "read failed at offset " << req.offset << " for "
<< req.dataLen << " bytes: " << strerror(eno); << req.dataLen << " bytes: " << strerror(eno);
return -eno; return -eno;
@ -219,37 +219,43 @@ ssize_t RawFileIO::write(const IORequest &req) {
rAssert(fd >= 0); rAssert(fd >= 0);
rAssert(canWrite); rAssert(canWrite);
int retrys = 10; // int retrys = 10;
void *buf = req.data; void *buf = req.data;
ssize_t bytes = req.dataLen; ssize_t bytes = req.dataLen;
off_t offset = req.offset; off_t offset = req.offset;
int eno = 0; /*
while ((bytes != 0) && retrys > 0) { * Let's write while pwrite() writes, to avoid writing only a part of the request,
errno = 0; * whereas it could have been fully written. This to avoid inconsistencies / corruption.
*/
// while ((bytes != 0) && retrys > 0) {
while (bytes != 0) {
ssize_t writeSize = ::pwrite(fd, buf, bytes, offset); ssize_t writeSize = ::pwrite(fd, buf, bytes, offset);
eno = errno;
errno = 0; //just to be sure error seen in integration tests really comes from the function rc.
if (writeSize < 0) { if (writeSize <= 0) {
int eno = errno;
errno = 0; //just to be sure error seen in integration tests really comes from the function rc.
knownSize = false; knownSize = false;
RLOG(WARNING) << "write failed at offset " << offset << " for " << bytes RLOG(WARNING) << "write failed at offset " << offset << " for " << bytes
<< " bytes: " << strerror(eno); << " bytes: " << strerror(eno);
return -eno; // pwrite is not expected to return 0, so eno should always be set, but we never know...
if (eno) {
return -eno;
}
return -EIO;
} }
bytes -= writeSize; bytes -= writeSize;
offset += writeSize; offset += writeSize;
buf = (void *)((char *)buf + writeSize); buf = (void *)((char *)buf + writeSize);
--retrys;
} }
if (bytes != 0) { // if (bytes != 0) {
RLOG(ERROR) << "Write error: wrote " << req.dataLen - bytes << " bytes of " // RLOG(ERROR) << "Write error: wrote " << req.dataLen - bytes << " bytes of "
<< req.dataLen << ", max retries reached"; // << req.dataLen << ", max retries reached";
knownSize = false; // knownSize = false;
return (eno) ? -eno : -EIO; // return (eno) ? -eno : -EIO;
} // }
if (knownSize) { if (knownSize) {
off_t last = req.offset + req.dataLen; off_t last = req.offset + req.dataLen;
if (last > fileSize) { if (last > fileSize) {