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authorMORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>2013-04-26 01:19:54 +0900
committerStefan Hajnoczi <stefanha@redhat.com>2013-04-26 13:26:28 +0200
commit13c31de2fdd534c065ce4710f6e8df3921e98c4f (patch)
tree754b5f7b68017f4bc0e9a8cf343f8f54e9099388 /block
parent9ff53a0eb89afacfa1ba56b009d40be942d3bd63 (diff)
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sheepdog: resend write requests when SD_RES_READONLY is received
When a snapshot is taken from out side of qemu (e.g. qemu-img snapshot), write requests to the current vdi return SD_RES_READONLY. In this case, the sheepdog block driver needs to update the current inode to the latest one and resend the write requests. Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/sheepdog.c60
1 files changed, 59 insertions, 1 deletions
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 0eaf4c3..77e21fd 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -605,6 +605,7 @@ static int do_req(int sockfd, SheepdogReq *hdr, void *data,
static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
struct iovec *iov, int niov, bool create,
enum AIOCBState aiocb_type);
+static int coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req);
static AIOReq *find_pending_req(BDRVSheepdogState *s, uint64_t oid)
@@ -749,9 +750,19 @@ static void coroutine_fn aio_read_response(void *opaque)
}
}
- if (rsp.result != SD_RES_SUCCESS) {
+ switch (rsp.result) {
+ case SD_RES_SUCCESS:
+ break;
+ case SD_RES_READONLY:
+ ret = resend_aioreq(s, aio_req);
+ if (ret == SD_RES_SUCCESS) {
+ goto out;
+ }
+ /* fall through */
+ default:
acb->ret = -EIO;
error_report("%s", sd_strerror(rsp.result));
+ break;
}
free_aio_req(s, aio_req);
@@ -1186,6 +1197,53 @@ out:
return ret;
}
+static int coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req)
+{
+ SheepdogAIOCB *acb = aio_req->aiocb;
+ bool create = false;
+ int ret;
+
+ ret = reload_inode(s, 0, "");
+ if (ret < 0) {
+ return ret;
+ }
+
+ aio_req->oid = vid_to_data_oid(s->inode.vdi_id,
+ data_oid_to_idx(aio_req->oid));
+
+ /* check whether this request becomes a CoW one */
+ if (acb->aiocb_type == AIOCB_WRITE_UDATA) {
+ int idx = data_oid_to_idx(aio_req->oid);
+ AIOReq *areq;
+
+ if (s->inode.data_vdi_id[idx] == 0) {
+ create = true;
+ goto out;
+ }
+ if (is_data_obj_writable(&s->inode, idx)) {
+ goto out;
+ }
+
+ /* link to the pending list if there is another CoW request to
+ * the same object */
+ QLIST_FOREACH(areq, &s->inflight_aio_head, aio_siblings) {
+ if (areq != aio_req && areq->oid == aio_req->oid) {
+ dprintf("simultaneous CoW to %" PRIx64 "\n", aio_req->oid);
+ QLIST_REMOVE(aio_req, aio_siblings);
+ QLIST_INSERT_HEAD(&s->pending_aio_head, aio_req, aio_siblings);
+ return SD_RES_SUCCESS;
+ }
+ }
+
+ aio_req->base_oid = vid_to_data_oid(s->inode.data_vdi_id[idx], idx);
+ aio_req->flags |= SD_FLAG_CMD_COW;
+ create = true;
+ }
+out:
+ return add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov,
+ create, acb->aiocb_type);
+}
+
/* TODO Convert to fine grained options */
static QemuOptsList runtime_opts = {
.name = "sheepdog",