int raw_export_start(RawExport *e, const char *path, int fd, ImportCompressType compress) {
_cleanup_close_ int sfd = -1, tfd = -1;
int r;
assert(e);
assert(path);
assert(fd >= 0);
assert(compress < _IMPORT_COMPRESS_TYPE_MAX);
assert(compress != IMPORT_COMPRESS_UNKNOWN);
if (e->output_fd >= 0)
return -EBUSY;
r = fd_nonblock(fd, true);
if (r < 0)
return r;
r = free_and_strdup(&e->path, path);
if (r < 0)
return r;
sfd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (sfd < 0)
return -errno;
if (fstat(sfd, &e->st) < 0)
return -errno;
r = stat_verify_regular(&e->st);
if (r < 0)
return r;
/* Try to take a reflink snapshot of the file, if we can t make the export atomic */
tfd = reflink_snapshot(sfd, path);
if (tfd >= 0)
e->input_fd = TAKE_FD(tfd);
else
e->input_fd = TAKE_FD(sfd);
r = import_compress_init(&e->compress, compress);
if (r < 0)
return r;
r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, raw_export_on_output, e);
if (r == -EPERM) {
r = sd_event_add_defer(e->event, &e->output_event_source, raw_export_on_defer, e);
if (r < 0)
return r;
r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON);
}
if (r < 0)
return r;
e->output_fd = fd;
return r;
}
int fd_verify_regular(int fd) {
struct stat st;
assert(fd >= 0);
if (fstat(fd, &st) < 0)
return -errno;
return stat_verify_regular(&st);
}
