Current cinfo_collection_work() and SD_OP_VDI_STATE_SNAPSHOT_CTL doesn't handle a case of small buffer. This patch solves it.
Cc: Saeki Masaki <[email protected]> Cc: Yuka Kawasaki <[email protected]> Signed-off-by: Hitoshi Mitake <[email protected]> --- sheep/group.c | 56 +++++++++++++++++++++++++++++++++++++++--------------- sheep/ops.c | 21 ++++++++++---------- sheep/sheep_priv.h | 3 ++- sheep/vdi.c | 24 ++++++++++++++++------- 4 files changed, 71 insertions(+), 33 deletions(-) v2: calculate correct length of buffer diff --git a/sheep/group.c b/sheep/group.c index 2b98a9b..e633bc3 100644 --- a/sheep/group.c +++ b/sheep/group.c @@ -694,43 +694,69 @@ struct cinfo_collection_work { static struct cinfo_collection_work *collect_work; -static void cinfo_collection_work(struct work *work) +static struct vdi_state *do_cinfo_collection_work(uint32_t epoch, + struct sd_node *n, + int *nr_vdi_states) { + struct vdi_state *vs = NULL; + unsigned int rlen = 512; struct sd_req hdr; struct sd_rsp *rsp = (struct sd_rsp *)&hdr; + int ret; + + vs = xcalloc(rlen, sizeof(*vs)); + +retry: + sd_init_req(&hdr, SD_OP_VDI_STATE_SNAPSHOT_CTL); + hdr.vdi_state_snapshot.get = 1; + hdr.vdi_state_snapshot.tgt_epoch = epoch; + hdr.data_length = rlen; + + ret = sheep_exec_req(&n->nid, &hdr, (char *)vs); + if (ret == SD_RES_SUCCESS) { + sd_debug("succeed to obtain snapshot of vdi states"); + *nr_vdi_states = rsp->data_length / sizeof(*vs); + return vs; + } else if (ret == SD_RES_BUFFER_SMALL) { + sd_debug("buffer is small for obtaining snapshot of vdi states," + " doubling it (%lu -> %lu)", rlen * sizeof(*vs), + rlen * 2 * sizeof(*vs)); + rlen *= 2; + vs = xrealloc(vs, sizeof(*vs) * rlen); + goto retry; + } + + sd_err("failed to obtain snapshot of vdi states from node %s", + node_to_str(n)); + return NULL; +} + +static void cinfo_collection_work(struct work *work) +{ + struct sd_req hdr; struct vdi_state *vs = NULL; - unsigned int rlen; struct cinfo_collection_work *w = container_of(work, struct cinfo_collection_work, work); struct sd_node *n; - int ret; + int ret, nr_vdi_states = 0; sd_debug("start collection of cinfo..."); assert(w == collect_work); - rlen = SD_DATA_OBJ_SIZE; /* FIXME */ - vs = xzalloc(rlen); - rb_for_each_entry(n, &w->members->nroot, rb) { if (node_is_local(n)) continue; - sd_init_req(&hdr, SD_OP_VDI_STATE_SNAPSHOT_CTL); - hdr.vdi_state_snapshot.get = 1; - hdr.vdi_state_snapshot.tgt_epoch = w->epoch; - hdr.data_length = rlen; - - ret = sheep_exec_req(&n->nid, &hdr, (char *)vs); - if (ret == SD_RES_SUCCESS) + vs = do_cinfo_collection_work(w->epoch, n, &nr_vdi_states); + if (vs) goto get_succeed; } panic("getting a snapshot of vdi state at epoch %d failed", w->epoch); get_succeed: - - w->nr_vdi_states = rsp->data_length / sizeof(*vs); + w->nr_vdi_states = nr_vdi_states; w->result = vs; sd_debug("collecting cinfo done, freeing from remote nodes"); diff --git a/sheep/ops.c b/sheep/ops.c index a617a83..3991060 100644 --- a/sheep/ops.c +++ b/sheep/ops.c @@ -1391,21 +1391,22 @@ static int local_vdi_state_snapshot_ctl(const struct sd_req *req, { bool get = !!req->vdi_state_snapshot.get; int epoch = req->vdi_state_snapshot.tgt_epoch; - int ret; + int ret, length = 0; sd_info("%s vdi state snapshot at epoch %d", get ? "getting" : "freeing", epoch); if (get) { - /* - * FIXME: assuming request has enough space for storing - * the snapshot - */ - ret = get_vdi_state_snapshot(epoch, data); - if (0 <= ret) - rsp->data_length = ret; - else - return SD_RES_AGAIN; + ret = get_vdi_state_snapshot(epoch, data, req->data_length, + &length); + if (ret == SD_RES_SUCCESS) + rsp->data_length = length; + else { + sd_err("failed to get vdi state snapshot: %s", + sd_strerror(ret)); + + return ret; + } } else free_vdi_state_snapshot(epoch); diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h index 5fc6b90..72817b9 100644 --- a/sheep/sheep_priv.h +++ b/sheep/sheep_priv.h @@ -344,7 +344,8 @@ bool vdi_lock(uint32_t vid, const struct node_id *owner, int type); bool vdi_unlock(uint32_t vid, const struct node_id *owner, int type); void apply_vdi_lock_state(struct vdi_state *vs); void take_vdi_state_snapshot(int epoch); -int get_vdi_state_snapshot(int epoch, void *data); +int get_vdi_state_snapshot(int epoch, void *data, int data_len_max, + int *data_len_result); void free_vdi_state_snapshot(int epoch); void log_vdi_op_lock(uint32_t vid, const struct node_id *owner, int type); void log_vdi_op_unlock(uint32_t vid, const struct node_id *owner, int type); diff --git a/sheep/vdi.c b/sheep/vdi.c index 1c8fb36..a85bbf5 100644 --- a/sheep/vdi.c +++ b/sheep/vdi.c @@ -1793,21 +1793,31 @@ main_fn void take_vdi_state_snapshot(int epoch) sd_debug("a number of vdi state: %d", snapshot->nr_vs); } -main_fn int get_vdi_state_snapshot(int epoch, void *data) +main_fn int get_vdi_state_snapshot(int epoch, void *data, int data_len_max, + int *data_len_result) { struct vdi_state_snapshot *snapshot; + int len; list_for_each_entry(snapshot, &vdi_state_snapshot_list, list) { - if (snapshot->epoch == epoch) { - memcpy(data, snapshot->vs, - sizeof(*snapshot->vs) * snapshot->nr_vs); - return sizeof(*snapshot->vs) * snapshot->nr_vs; - } + if (snapshot->epoch == epoch) + goto found; } sd_info("get request for not prepared vdi state snapshot, epoch: %d", epoch); - return -1; + return SD_RES_AGAIN; + +found: + len = sizeof(*snapshot->vs) * snapshot->nr_vs; + if (data_len_max < len) { + sd_info("maximum allowed length: %d, required length: %d", + data_len_max, len); + return SD_RES_BUFFER_SMALL; + } + + memcpy(data, snapshot->vs, len); + return len; } main_fn void free_vdi_state_snapshot(int epoch) -- 1.8.3.2 -- sheepdog mailing list [email protected] http://lists.wpkg.org/mailman/listinfo/sheepdog
