static int raw_import_try_reflink(RawImport *i) {
off_t p;
int r;
assert(i);
assert(i->input_fd >= 0);
assert(i->output_fd >= 0);
if (i->compress.type != IMPORT_COMPRESS_UNCOMPRESSED)
return 0;
if (!S_ISREG(i->st.st_mode))
return 0;
p = lseek(i->input_fd, 0, SEEK_CUR);
if (p == (off_t) -1)
return log_error_errno(errno, "Failed to read file offset of input file: %m");
/* Let's only try a btrfs reflink, if we are reading from the beginning of the file */
if ((uint64_t) p != (uint64_t) i->buffer_size)
return 0;
r = btrfs_reflink(i->input_fd, i->output_fd);
if (r >= 0)
return 1;
return 0;
}
static int reflink_snapshot(int fd, const char *path) {
char *p, *d;
int new_fd, r;
p = strdupa(path);
d = dirname(p);
new_fd = open(d, O_TMPFILE|O_CLOEXEC|O_NOCTTY|O_RDWR, 0600);
if (new_fd < 0) {
_cleanup_free_ char *t = NULL;
r = tempfn_random(path, NULL, &t);
if (r < 0)
return r;
new_fd = open(t, O_CLOEXEC|O_CREAT|O_NOCTTY|O_RDWR, 0600);
if (new_fd < 0)
return -errno;
(void) unlink(t);
}
r = btrfs_reflink(fd, new_fd);
if (r < 0) {
safe_close(new_fd);
return r;
}
return new_fd;
}
static int raw_export_process(RawExport *e) {
ssize_t l;
int r;
assert(e);
if (!e->tried_reflink && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
/* If we shall take an uncompressed snapshot we can
* reflink source to destination directly. Let's see
* if this works. */
r = btrfs_reflink(e->input_fd, e->output_fd);
if (r >= 0) {
r = 0;
goto finish;
}
e->tried_reflink = true;
}
if (!e->tried_sendfile && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
l = sendfile(e->output_fd, e->input_fd, NULL, COPY_BUFFER_SIZE);
if (l < 0) {
if (errno == EAGAIN)
return 0;
e->tried_sendfile = true;
} else if (l == 0) {
r = 0;
goto finish;
} else {
e->written_uncompressed += l;
e->written_compressed += l;
raw_export_report_progress(e);
return 0;
}
}
while (e->buffer_size <= 0) {
uint8_t input[COPY_BUFFER_SIZE];
if (e->eof) {
r = 0;
goto finish;
}
l = read(e->input_fd, input, sizeof(input));
if (l < 0) {
r = log_error_errno(errno, "Failed to read raw file: %m");
goto finish;
}
if (l == 0) {
e->eof = true;
r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated);
} else {
e->written_uncompressed += l;
r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated);
}
if (r < 0) {
r = log_error_errno(r, "Failed to encode: %m");
goto finish;
}
}
l = write(e->output_fd, e->buffer, e->buffer_size);
if (l < 0) {
if (errno == EAGAIN)
return 0;
r = log_error_errno(errno, "Failed to write output file: %m");
goto finish;
}
assert((size_t) l <= e->buffer_size);
memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l);
e->buffer_size -= l;
e->written_compressed += l;
raw_export_report_progress(e);
return 0;
finish:
if (r >= 0) {
(void) copy_times(e->input_fd, e->output_fd);
(void) copy_xattr(e->input_fd, e->output_fd);
}
if (e->on_finished)
e->on_finished(e, r, e->userdata);
else
sd_event_exit(e->event, r);
return 0;
}
int copy_bytes(int fdf, int fdt, off_t max_bytes, bool try_reflink) {
bool try_sendfile = true;
int r;
assert(fdf >= 0);
assert(fdt >= 0);
/* Try btrfs reflinks first. */
if (try_reflink && max_bytes == (off_t) -1) {
r = btrfs_reflink(fdf, fdt);
if (r >= 0)
return r;
}
for (;;) {
size_t m = COPY_BUFFER_SIZE;
ssize_t n;
if (max_bytes != (off_t) -1) {
if (max_bytes <= 0)
return -EFBIG;
if ((off_t) m > max_bytes)
m = (size_t) max_bytes;
}
/* First try sendfile(), unless we already tried */
if (try_sendfile) {
n = sendfile(fdt, fdf, NULL, m);
if (n < 0) {
if (errno != EINVAL && errno != ENOSYS)
return -errno;
try_sendfile = false;
/* use fallback below */
} else if (n == 0) /* EOF */
break;
else if (n > 0)
/* Succcess! */
goto next;
}
/* As a fallback just copy bits by hand */
{
char buf[m];
n = read(fdf, buf, m);
if (n < 0)
return -errno;
if (n == 0) /* EOF */
break;
r = loop_write(fdt, buf, (size_t) n, false);
if (r < 0)
return r;
}
next:
if (max_bytes != (off_t) -1) {
assert(max_bytes >= n);
max_bytes -= n;
}
}
return 0;
}
