1. /* This is a wrapper to the write syscall in order to retry on short writes
    2.  * or if the syscall gets interrupted. It could look strange that we retry
    3.  * on short writes given that we are writing to a block device: normally if
    4.  * the first call is short, there is a end-of-space condition, so the next
    5.  * is likely to fail. However apparently in modern systems this is no longer
    6.  * true, and in general it looks just more resilient to retry the write. If
    7.  * there is an actual error condition we'll get it at the next try. */
    8. ssize_t aofWrite(int fd, const char *buf, size_t len)
    9. {
    10.     ssize_t nwritten = 0, totwritten = 0;
    12.     while (len)
    13.     {
    14.         nwritten = write(fd, buf, len);
    16.         if (nwritten < 0)
    17.         {
    18.             if (errno == EINTR)
    19.                 continue;
    20.             return totwritten ? totwritten : -1;
    21.         }
    23.         len -= nwritten;
    24.         buf += nwritten;
    25.         totwritten += nwritten;
    26.     }
    28.     return totwritten;
    29. }