static int get_object_path(uint64_t oid, uint32_t epoch, char *path)
{
if (default_exist(oid)) {
get_obj_path(oid, path);
} else {
get_stale_obj_path(oid, epoch, path);
if (access(path, F_OK) < 0) {
if (errno == ENOENT)
return SD_RES_NO_OBJ;
return SD_RES_EIO;
}
}
return SD_RES_SUCCESS;
}
static int move_object_to_stale_dir(uint64_t oid, void *arg)
{
char path[PATH_MAX], stale_path[PATH_MAX];
uint32_t tgt_epoch = *(int *)arg;
get_obj_path(oid, path);
get_stale_obj_path(oid, tgt_epoch, stale_path);
if (rename(path, stale_path) < 0) {
eprintf("failed to move stale object %"PRIX64" to %s, %m\n",
oid, path);
return SD_RES_EIO;
}
dprintf("moved object %"PRIx64"\n", oid);
return SD_RES_SUCCESS;
}
int default_link(uint64_t oid, struct siocb *iocb, uint32_t tgt_epoch)
{
char path[PATH_MAX], stale_path[PATH_MAX];
dprintf("try link %"PRIx64" from snapshot with epoch %d\n", oid,
tgt_epoch);
get_obj_path(oid, path);
get_stale_obj_path(oid, tgt_epoch, stale_path);
if (link(stale_path, path) < 0) {
eprintf("failed to link from %s to %s, %m\n", stale_path,
path);
return err_to_sderr(oid, errno);
}
return SD_RES_SUCCESS;
}
int default_read(uint64_t oid, struct siocb *iocb)
{
int ret;
char path[PATH_MAX];
uint32_t epoch = sys_epoch();
get_obj_path(oid, path);
ret = default_read_from_path(oid, path, iocb);
/* If the request is againt the older epoch, try to read from
* the stale directory */
while (ret == SD_RES_NO_OBJ && iocb->epoch < epoch) {
epoch--;
get_stale_obj_path(oid, epoch, path);
ret = default_read_from_path(oid, path, iocb);
}
return ret;
}
int default_read(uint64_t oid, const struct siocb *iocb)
{
int ret;
char path[PATH_MAX];
get_obj_path(oid, path);
ret = default_read_from_path(oid, path, iocb);
/*
* If the request is againt the older epoch, try to read from
* the stale directory
*/
if (ret == SD_RES_NO_OBJ && iocb->epoch > 0 &&
iocb->epoch < sys_epoch()) {
get_stale_obj_path(oid, iocb->epoch, path);
ret = default_read_from_path(oid, path, iocb);
}
return ret;
}
int default_link(uint64_t oid, uint32_t tgt_epoch)
{
char path[PATH_MAX], stale_path[PATH_MAX];
sd_debug("try link %"PRIx64" from snapshot with epoch %d", oid,
tgt_epoch);
get_obj_path(oid, path);
get_stale_obj_path(oid, tgt_epoch, stale_path);
if (link(stale_path, path) < 0) {
/*
* Recovery thread and main thread might try to recover the
* same object and we might get EEXIST in such case.
*/
if (errno == EEXIST)
goto out;
sd_debug("failed to link from %s to %s, %m", stale_path, path);
return err_to_sderr(path, oid, errno);
}
out:
return SD_RES_SUCCESS;
}
