libceph: update osd request/reply encoding

Use the new version of the encoding for osd requests and replies.  In the
process, update the way we are tracking request ops and reply lengths and
results in the struct ceph_osd_request.  Update the rbd and fs/ceph users
appropriately.

The main changes are:
 - we keep pointers into the request memory for fields we need to update
   each time the request is sent out over the wire
 - we keep information about the result in an array in the request struct
   where the users can easily get at it.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

2 files changed, 174 insertions, 77 deletions

diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
index f4d4b27d6026..00d051f4894e 100644
--- a/net/ceph/debugfs.c
+++ b/net/ceph/debugfs.c
@@ -123,10 +123,7 @@ static int osdc_show(struct seq_file *s, void *pp)
 	mutex_lock(&osdc->request_mutex);
 	for (p = rb_first(&osdc->requests); p; p = rb_next(p)) {
 		struct ceph_osd_request *req;
-		struct ceph_osd_request_head *head;
-		struct ceph_osd_op *op;
-		int num_ops;
-		int opcode, olen;
+		int opcode;
 		int i;
 
 		req = rb_entry(p, struct ceph_osd_request, r_node);
@@ -135,13 +132,7 @@ static int osdc_show(struct seq_file *s, void *pp)
 			   req->r_osd ? req->r_osd->o_osd : -1,
 			   req->r_pgid.pool, req->r_pgid.seed);
 
-		head = req->r_request->front.iov_base;
-		op = (void *)(head + 1);
-
-		num_ops = le16_to_cpu(head->num_ops);
-		olen = le32_to_cpu(head->object_len);
-		seq_printf(s, "%.*s", olen,
-			   (const char *)(head->ops + num_ops));
+		seq_printf(s, "%.*s", req->r_oid_len, req->r_oid);
 
 		if (req->r_reassert_version.epoch)
 			seq_printf(s, "\t%u'%llu",
@@ -150,10 +141,9 @@ static int osdc_show(struct seq_file *s, void *pp)
 		else
 			seq_printf(s, "\t");
 
-		for (i = 0; i < num_ops; i++) {
-			opcode = le16_to_cpu(op->op);
+		for (i = 0; i < req->r_num_ops; i++) {
+			opcode = le16_to_cpu(req->r_request_ops[i].op);
 			seq_printf(s, "\t%s", ceph_osd_op_name(opcode));
-			op++;
 		}
 
 		seq_printf(s, "\n");
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 5584f0a08e28..d730dd4d8eb2 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -146,15 +146,23 @@ EXPORT_SYMBOL(ceph_osdc_release_request);
 
 struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
 					       struct ceph_snap_context *snapc,
-					       unsigned int num_op,
+					       unsigned int num_ops,
 					       bool use_mempool,
 					       gfp_t gfp_flags)
 {
 	struct ceph_osd_request *req;
 	struct ceph_msg *msg;
-	size_t msg_size = sizeof(struct ceph_osd_request_head);
-
-	msg_size += num_op*sizeof(struct ceph_osd_op);
+	size_t msg_size;
+
+	msg_size = 4 + 4 + 8 + 8 + 4+8;
+	msg_size += 2 + 4 + 8 + 4 + 4; /* oloc */
+	msg_size += 1 + 8 + 4 + 4;     /* pg_t */
+	msg_size += 4 + MAX_OBJ_NAME_SIZE;
+	msg_size += 2 + num_ops*sizeof(struct ceph_osd_op);
+	msg_size += 8;  /* snapid */
+	msg_size += 8;  /* snap_seq */
+	msg_size += 8 * (snapc ? snapc->num_snaps : 0);  /* snaps */
+	msg_size += 4;
 
 	if (use_mempool) {
 		req = mempool_alloc(osdc->req_mempool, gfp_flags);
@@ -193,9 +201,6 @@ struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
 	ceph_pagelist_init(&req->r_trail);
 
 	/* create request message; allow space for oid */
-	msg_size += MAX_OBJ_NAME_SIZE;
-	if (snapc)
-		msg_size += sizeof(u64) * snapc->num_snaps;
 	if (use_mempool)
 		msg = ceph_msgpool_get(&osdc->msgpool_op, 0);
 	else
@@ -324,55 +329,80 @@ static void osd_req_encode_op(struct ceph_osd_request *req,
  *
  */
 void ceph_osdc_build_request(struct ceph_osd_request *req,
-			     u64 off, u64 len, unsigned int num_op,
+			     u64 off, u64 len, unsigned int num_ops,
 			     struct ceph_osd_req_op *src_ops,
 			     struct ceph_snap_context *snapc, u64 snap_id,
 			     struct timespec *mtime)
 {
 	struct ceph_msg *msg = req->r_request;
-	struct ceph_osd_request_head *head;
 	struct ceph_osd_req_op *src_op;
-	struct ceph_osd_op *op;
 	void *p;
-	size_t msg_size = sizeof(*head) + num_op*sizeof(*op);
+	size_t msg_size;
 	int flags = req->r_flags;
 	u64 data_len;
 	int i;
 
-	WARN_ON((flags & (CEPH_OSD_FLAG_READ|CEPH_OSD_FLAG_WRITE)) == 0);
-
-	head = msg->front.iov_base;
-	head->snapid = cpu_to_le64(snap_id);
-	op = (void *)(head + 1);
-	p = (void *)(op + num_op);
-
+	req->r_num_ops = num_ops;
+	req->r_snapid = snap_id;
 	req->r_snapc = ceph_get_snap_context(snapc);
 
-	head->client_inc = cpu_to_le32(1); /* always, for now. */
-	head->flags = cpu_to_le32(flags);
-	if (flags & CEPH_OSD_FLAG_WRITE)
-		ceph_encode_timespec(&head->mtime, mtime);
-	BUG_ON(num_op > (unsigned int) ((u16) -1));
-	head->num_ops = cpu_to_le16(num_op);
+	/* encode request */
+	msg->hdr.version = cpu_to_le16(4);
 
-	/* fill in oid */
-	head->object_len = cpu_to_le32(req->r_oid_len);
+	p = msg->front.iov_base;
+	ceph_encode_32(&p, 1);   /* client_inc  is always 1 */
+	req->r_request_osdmap_epoch = p;
+	p += 4;
+	req->r_request_flags = p;
+	p += 4;
+	if (req->r_flags & CEPH_OSD_FLAG_WRITE)
+		ceph_encode_timespec(p, mtime);
+	p += sizeof(struct ceph_timespec);
+	req->r_request_reassert_version = p;
+	p += sizeof(struct ceph_eversion); /* will get filled in */
+
+	/* oloc */
+	ceph_encode_8(&p, 4);
+	ceph_encode_8(&p, 4);
+	ceph_encode_32(&p, 8 + 4 + 4);
+	req->r_request_pool = p;
+	p += 8;
+	ceph_encode_32(&p, -1);  /* preferred */
+	ceph_encode_32(&p, 0);   /* key len */
+
+	ceph_encode_8(&p, 1);
+	req->r_request_pgid = p;
+	p += 8 + 4;
+	ceph_encode_32(&p, -1);  /* preferred */
+
+	/* oid */
+	ceph_encode_32(&p, req->r_oid_len);
 	memcpy(p, req->r_oid, req->r_oid_len);
+	dout("oid '%.*s' len %d\n", req->r_oid_len, req->r_oid, req->r_oid_len);
 	p += req->r_oid_len;
 
+	/* ops */
+	ceph_encode_16(&p, num_ops);
 	src_op = src_ops;
-	while (num_op--)
-		osd_req_encode_op(req, op++, src_op++);
+	req->r_request_ops = p;
+	for (i = 0; i < num_ops; i++, src_op++) {
+		osd_req_encode_op(req, p, src_op);
+		p += sizeof(struct ceph_osd_op);
+	}
 
-	if (snapc) {
-		head->snap_seq = cpu_to_le64(snapc->seq);
-		head->num_snaps = cpu_to_le32(snapc->num_snaps);
+	/* snaps */
+	ceph_encode_64(&p, req->r_snapid);
+	ceph_encode_64(&p, req->r_snapc ? req->r_snapc->seq : 0);
+	ceph_encode_32(&p, req->r_snapc ? req->r_snapc->num_snaps : 0);
+	if (req->r_snapc) {
 		for (i = 0; i < snapc->num_snaps; i++) {
-			put_unaligned_le64(snapc->snaps[i], p);
-			p += sizeof(u64);
+			ceph_encode_64(&p, req->r_snapc->snaps[i]);
 		}
 	}
 
+	req->r_request_attempts = p;
+	p += 4;
+
 	data_len = req->r_trail.length;
 	if (flags & CEPH_OSD_FLAG_WRITE) {
 		req->r_request->hdr.data_off = cpu_to_le16(off);
@@ -385,6 +415,9 @@ void ceph_osdc_build_request(struct ceph_osd_request *req,
 	msg_size = p - msg->front.iov_base;
 	msg->front.iov_len = msg_size;
 	msg->hdr.front_len = cpu_to_le32(msg_size);
+
+	dout("build_request msg_size was %d num_ops %d\n", (int)msg_size,
+	     num_ops);
 	return;
 }
 EXPORT_SYMBOL(ceph_osdc_build_request);
@@ -991,21 +1024,22 @@ out:
 static void __send_request(struct ceph_osd_client *osdc,
 			   struct ceph_osd_request *req)
 {
-	struct ceph_osd_request_head *reqhead;
-
-	dout("send_request %p tid %llu to osd%d flags %d\n",
-	     req, req->r_tid, req->r_osd->o_osd, req->r_flags);
-
-	reqhead = req->r_request->front.iov_base;
-	reqhead->snapid = cpu_to_le64(req->r_snapid);
-	reqhead->osdmap_epoch = cpu_to_le32(osdc->osdmap->epoch);
-	reqhead->flags |= cpu_to_le32(req->r_flags);  /* e.g., RETRY */
-	reqhead->reassert_version = req->r_reassert_version;
+	void *p;
 
-	reqhead->layout.ol_pgid.ps = cpu_to_le16(req->r_pgid.seed);
-	reqhead->layout.ol_pgid.pool = cpu_to_le32(req->r_pgid.pool);
-	reqhead->layout.ol_pgid.preferred = cpu_to_le16(-1);
-	reqhead->layout.ol_stripe_unit = 0;
+	dout("send_request %p tid %llu to osd%d flags %d pg %lld.%x\n",
+	     req, req->r_tid, req->r_osd->o_osd, req->r_flags,
+	     (unsigned long long)req->r_pgid.pool, req->r_pgid.seed);
+
+	/* fill in message content that changes each time we send it */
+	put_unaligned_le32(osdc->osdmap->epoch, req->r_request_osdmap_epoch);
+	put_unaligned_le32(req->r_flags, req->r_request_flags);
+	put_unaligned_le64(req->r_pgid.pool, req->r_request_pool);
+	p = req->r_request_pgid;
+	ceph_encode_64(&p, req->r_pgid.pool);
+	ceph_encode_32(&p, req->r_pgid.seed);
+	put_unaligned_le64(1, req->r_request_attempts);  /* FIXME */
+	memcpy(req->r_request_reassert_version, &req->r_reassert_version,
+	       sizeof(req->r_reassert_version));
 
 	req->r_stamp = jiffies;
 	list_move_tail(&req->r_req_lru_item, &osdc->req_lru);
@@ -1105,6 +1139,26 @@ static void complete_request(struct ceph_osd_request *req)
 	complete_all(&req->r_safe_completion);  /* fsync waiter */
 }
 
+static int __decode_pgid(void **p, void *end, struct ceph_pg *pgid)
+{
+	__u8 v;
+
+	ceph_decode_need(p, end, 1 + 8 + 4 + 4, bad);
+	v = ceph_decode_8(p);
+	if (v > 1) {
+		pr_warning("do not understand pg encoding %d > 1", v);
+		return -EINVAL;
+	}
+	pgid->pool = ceph_decode_64(p);
+	pgid->seed = ceph_decode_32(p);
+	*p += 4;
+	return 0;
+
+bad:
+	pr_warning("incomplete pg encoding");
+	return -EINVAL;
+}
+
 /*
  * handle osd op reply.  either call the callback if it is specified,
  * or do the completion to wake up the waiting thread.
@@ -1112,22 +1166,42 @@ static void complete_request(struct ceph_osd_request *req)
 static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 			 struct ceph_connection *con)
 {
-	struct ceph_osd_reply_head *rhead = msg->front.iov_base;
+	void *p, *end;
 	struct ceph_osd_request *req;
 	u64 tid;
-	int numops, object_len, flags;
+	int object_len;
+	int numops, payload_len, flags;
 	s32 result;
+	s32 retry_attempt;
+	struct ceph_pg pg;
+	int err;
+	u32 reassert_epoch;
+	u64 reassert_version;
+	u32 osdmap_epoch;
+	int i;
 
 	tid = le64_to_cpu(msg->hdr.tid);
-	if (msg->front.iov_len < sizeof(*rhead))
-		goto bad;
-	numops = le32_to_cpu(rhead->num_ops);
-	object_len = le32_to_cpu(rhead->object_len);
-	result = le32_to_cpu(rhead->result);
-	if (msg->front.iov_len != sizeof(*rhead) + object_len +
-	    numops * sizeof(struct ceph_osd_op))
+	dout("handle_reply %p tid %llu\n", msg, tid);
+
+	p = msg->front.iov_base;
+	end = p + msg->front.iov_len;
+
+	ceph_decode_need(&p, end, 4, bad);
+	object_len = ceph_decode_32(&p);
+	ceph_decode_need(&p, end, object_len, bad);
+	p += object_len;
+
+	err = __decode_pgid(&p, end, &pg);
+	if (err)
 		goto bad;
-	dout("handle_reply %p tid %llu result %d\n", msg, tid, (int)result);
+
+	ceph_decode_need(&p, end, 8 + 4 + 4 + 8 + 4, bad);
+	flags = ceph_decode_64(&p);
+	result = ceph_decode_32(&p);
+	reassert_epoch = ceph_decode_32(&p);
+	reassert_version = ceph_decode_64(&p);
+	osdmap_epoch = ceph_decode_32(&p);
+
 	/* lookup */
 	mutex_lock(&osdc->request_mutex);
 	req = __lookup_request(osdc, tid);
@@ -1137,7 +1211,38 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 		return;
 	}
 	ceph_osdc_get_request(req);
-	flags = le32_to_cpu(rhead->flags);
+
+	dout("handle_reply %p tid %llu req %p result %d\n", msg, tid,
+	     req, result);
+
+	ceph_decode_need(&p, end, 4, bad);
+	numops = ceph_decode_32(&p);
+	if (numops > CEPH_OSD_MAX_OP)
+		goto bad_put;
+	if (numops != req->r_num_ops)
+		goto bad_put;
+	payload_len = 0;
+	ceph_decode_need(&p, end, numops * sizeof(struct ceph_osd_op), bad);
+	for (i = 0; i < numops; i++) {
+		struct ceph_osd_op *op = p;
+		int len;
+
+		len = le32_to_cpu(op->payload_len);
+		req->r_reply_op_len[i] = len;
+		dout(" op %d has %d bytes\n", i, len);
+		payload_len += len;
+		p += sizeof(*op);
+	}
+	if (payload_len != le32_to_cpu(msg->hdr.data_len)) {
+		pr_warning("sum of op payload lens %d != data_len %d",
+			   payload_len, le32_to_cpu(msg->hdr.data_len));
+		goto bad_put;
+	}
+
+	ceph_decode_need(&p, end, 4 + numops * 4, bad);
+	retry_attempt = ceph_decode_32(&p);
+	for (i = 0; i < numops; i++)
+		req->r_reply_op_result[i] = ceph_decode_32(&p);
 
 	/*
 	 * if this connection filled our message, drop our reference now, to
@@ -1152,7 +1257,7 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 	if (!req->r_got_reply) {
 		unsigned int bytes;
 
-		req->r_result = le32_to_cpu(rhead->result);
+		req->r_result = result;
 		bytes = le32_to_cpu(msg->hdr.data_len);
 		dout("handle_reply result %d bytes %d\n", req->r_result,
 		     bytes);
@@ -1160,7 +1265,8 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 			req->r_result = bytes;
 
 		/* in case this is a write and we need to replay, */
-		req->r_reassert_version = rhead->reassert_version;
+		req->r_reassert_version.epoch = cpu_to_le32(reassert_epoch);
+		req->r_reassert_version.version = cpu_to_le64(reassert_version);
 
 		req->r_got_reply = 1;
 	} else if ((flags & CEPH_OSD_FLAG_ONDISK) == 0) {
@@ -1195,10 +1301,11 @@ done:
 	ceph_osdc_put_request(req);
 	return;
 
+bad_put:
+	ceph_osdc_put_request(req);
 bad:
-	pr_err("corrupt osd_op_reply got %d %d expected %d\n",
-	       (int)msg->front.iov_len, le32_to_cpu(msg->hdr.front_len),
-	       (int)sizeof(*rhead));
+	pr_err("corrupt osd_op_reply got %d %d\n",
+	       (int)msg->front.iov_len, le32_to_cpu(msg->hdr.front_len));
 	ceph_msg_dump(msg);
 }