static int FSWrite(const char *destination, int dd, const char *buf, size_t n_write)
{
const void *cur = buf;
const void *end = buf + n_write;
while (cur < end)
{
const void *skip_span = MemSpan(cur, 0, end - cur);
if (skip_span > cur)
{
if (lseek(dd, skip_span - cur, SEEK_CUR) < 0)
{
Log(LOG_LEVEL_ERR, "Copy failed (no space?) while copying to '%s' from network '%s'", destination, GetErrorStr());
return false;
}
cur = skip_span;
}
const void *copy_span = MemSpanInverse(cur, 0, end - cur);
if (copy_span > cur)
{
if (FullWrite(dd, cur, copy_span - cur) < 0)
{
Log(LOG_LEVEL_ERR, "Copy failed (no space?) while copying to '%s' from network '%s'", destination, GetErrorStr());
return false;
}
cur = copy_span;
}
}
return true;
}
/*
* Copy data jumping over areas filled by '\0', so files automatically become sparse if possible.
*/
static bool CopyData(const char *source, int sd, const char *destination, int dd, char *buf, size_t buf_size)
{
off_t n_read_total = 0;
while (true)
{
ssize_t n_read = read(sd, buf, buf_size);
if (n_read == -1)
{
if (errno == EINTR)
{
continue;
}
CfOut(OUTPUT_LEVEL_ERROR, "read", "Unable to read source file while doing %s to %s", source, destination);
return false;
}
if (n_read == 0)
{
/*
* As the tail of file may contain of bytes '\0' (and hence
* lseek(2)ed on destination instead of being written), do a
* ftruncate(2) here to ensure the whole file is written to the
* disc.
*/
if (ftruncate(dd, n_read_total) < 0)
{
CfOut(OUTPUT_LEVEL_ERROR, "ftruncate", "Copy failed (no space?) while doing %s to %s", source, destination);
return false;
}
return true;
}
n_read_total += n_read;
/* Copy/seek */
void *cur = buf;
void *end = buf + n_read;
while (cur < end)
{
void *skip_span = MemSpan(cur, 0, end - cur);
if (skip_span > cur)
{
if (lseek(dd, skip_span - cur, SEEK_CUR) < 0)
{
CfOut(OUTPUT_LEVEL_ERROR, "lseek", "Copy failed (no space?) while doing %s to %s", source, destination);
return false;
}
cur = skip_span;
}
void *copy_span = MemSpanInverse(cur, 0, end - cur);
if (copy_span > cur)
{
if (FullWrite(dd, cur, copy_span - cur) < 0)
{
CfOut(OUTPUT_LEVEL_ERROR, "write", "Copy failed (no space?) while doing %s to %s", source, destination);
return false;
}
cur = copy_span;
}
}
}
}