support watch/notify version 2

From: Mike Christie <[email protected]>

This patch adds support for proto version 1 of watch-notify, so drivers like rbd can be sent a buffer with information like the notify operation being performed.

Signed-off-by Mike Christie <[email protected]>

---
  drivers/block/rbd.c             |  3 ++-
  include/linux/ceph/osd_client.h |  7 +++++--
  net/ceph/osd_client.c           | 21 ++++++++++++++++-----
  3 files changed, 23 insertions(+), 8 deletions(-)

drivers/block/rbd.c +2 -1

index 89fe8a4..4b9ba9f 100644
@@ -3103,7 +3103,8 @@ out:
  	return ret;
  }
 
-static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
+static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data,
+			 void *payload, int payload_len)
  {
  	struct rbd_device *rbd_dev = (struct rbd_device *)data;
  	int ret;

include/linux/ceph/osd_client.h +5 -2

index 7506b48..eab96b5 100644
@@ -184,7 +184,7 @@ struct ceph_osd_event {
  	u64 cookie;
  	int one_shot;
  	struct ceph_osd_client *osdc;
-	void (*cb)(u64, u64, u8, void *);
+	void (*cb)(u64, u64, u8, void *, void *, int);
  	void *data;
  	struct rb_node node;
  	struct list_head osd_node;

@@ -197,6 +197,8 @@ struct ceph_osd_event_work {
          u64 ver;
          u64 notify_id;
          u8 opcode;
+	void *payload;
+	int payload_len;
  };
 
  struct ceph_osd_client {

@@ -369,7 +371,8 @@ extern int ceph_osdc_writepages(struct ceph_osd_client *osdc,
 
  /* watch/notify events */
  extern int ceph_osdc_create_event(struct ceph_osd_client *osdc,
-				  void (*event_cb)(u64, u64, u8, void *),
+				  void (*event_cb)(u64, u64, u8, void *, void *,
+						   int),
  				  void *data, struct ceph_osd_event **pevent);
  extern void ceph_osdc_cancel_event(struct ceph_osd_event *event);
  extern void ceph_osdc_put_event(struct ceph_osd_event *event);

net/ceph/osd_client.c +16 -5

index 5003367..aa1c5c46 100644
@@ -2277,7 +2277,7 @@ static void __remove_event(struct ceph_osd_event *event)
  }
 
  int ceph_osdc_create_event(struct ceph_osd_client *osdc,
-			   void (*event_cb)(u64, u64, u8, void *),
+			   void (*event_cb)(u64, u64, u8, void *, void *, int),
  			   void *data, struct ceph_osd_event **pevent)
  {
  	struct ceph_osd_event *event;

@@ -2329,7 +2329,8 @@ static void do_event_work(struct work_struct *work)
  	u8 opcode = event_work->opcode;
 
  	dout("do_event_work completing %p\n", event);
-	event->cb(ver, notify_id, opcode, event->data);
+	event->cb(ver, notify_id, opcode, event->data, event_work->payload,
+		  event_work->payload_len);
  	dout("do_event_work completed %p\n", event);
  	ceph_osdc_put_event(event);
  	kfree(event_work);

@@ -2342,10 +2343,11 @@ static void do_event_work(struct work_struct *work)
  static void handle_watch_notify(struct ceph_osd_client *osdc,
  				struct ceph_msg *msg)
  {
-	void *p, *end;
+	void *p, *end, *payload = NULL;
  	u8 proto_ver;
  	u64 cookie, ver, notify_id;
  	u8 opcode;
+	u32 payload_len = 0;
  	struct ceph_osd_event *event;
  	struct ceph_osd_event_work *event_work;
 

@@ -2358,6 +2360,13 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  	ceph_decode_64_safe(&p, end, ver, bad);
  	ceph_decode_64_safe(&p, end, notify_id, bad);
 
+	if (proto_ver >= 1) {
+		ceph_decode_32_safe(&p, end, payload_len, bad);
+		if (end - p < payload_len)
+			goto bad;
+		payload = p;
+	}
+
  	spin_lock(&osdc->event_lock);
  	event = __find_event(osdc, cookie);
  	if (event) {

@@ -2365,8 +2374,8 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  		get_event(event);
  	}
  	spin_unlock(&osdc->event_lock);
-	dout("handle_watch_notify cookie %lld ver %lld event %p\n",
-	     cookie, ver, event);
+	dout("handle_watch_notify cookie %lld ver %lld event %p notify id %llu payload len %u\n",
+	     cookie, ver, event, notify_id, payload_len);
  	if (event) {
  		event_work = kmalloc(sizeof(*event_work), GFP_NOIO);
  		if (!event_work) {

@@ -2379,6 +2388,8 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  		event_work->ver = ver;
  		event_work->notify_id = notify_id;
  		event_work->opcode = opcode;
+		event_work->payload = payload;
+		event_work->payload_len = payload_len;
 
  		queue_work(osdc->notify_wq, &event_work->work);
  	}

From: Mike Christie <[email protected]>

This adds support watch-notify header 2 and 3 support, so we can get a return_code from those operations.

Signed-off-by Mike Christie <[email protected]>

---
  drivers/block/rbd.c             |  5 +++--
  include/linux/ceph/osd_client.h | 10 ++++++----
  net/ceph/osd_client.c           | 25 +++++++++++++++++++------
  3 files changed, 28 insertions(+), 12 deletions(-)

drivers/block/rbd.c +3 -2

index 4b9ba9f..65421eb 100644
@@ -3103,8 +3103,9 @@ out:
  	return ret;
  }
 
-static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data,
-			 void *payload, int payload_len)
+static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code,
+			 u64 notifier_gid, void *data, void *payload,
+			 u32 payload_len)
  {
  	struct rbd_device *rbd_dev = (struct rbd_device *)data;
  	int ret;

include/linux/ceph/osd_client.h +6 -4

index eab96b5..1c4e472 100644
@@ -184,7 +184,7 @@ struct ceph_osd_event {
  	u64 cookie;
  	int one_shot;
  	struct ceph_osd_client *osdc;
-	void (*cb)(u64, u64, u8, void *, void *, int);
+	void (*cb)(u64, u64, u8, s32, u64, void *, void *, u32);
  	void *data;
  	struct rb_node node;
  	struct list_head osd_node;

@@ -197,8 +197,10 @@ struct ceph_osd_event_work {
          u64 ver;
          u64 notify_id;
          u8 opcode;
+	s32 return_code;
+	u64 notifier_gid;
  	void *payload;
-	int payload_len;
+	u32 payload_len;
  };
 
  struct ceph_osd_client {

@@ -371,8 +373,8 @@ extern int ceph_osdc_writepages(struct ceph_osd_client *osdc,
 
  /* watch/notify events */
  extern int ceph_osdc_create_event(struct ceph_osd_client *osdc,
-				  void (*event_cb)(u64, u64, u8, void *, void *,
-						   int),
+				  void (*event_cb)(u64, u64, u8, s32, u64,
+						   void *, void *, u32),
  				  void *data, struct ceph_osd_event **pevent);
  extern void ceph_osdc_cancel_event(struct ceph_osd_event *event);
  extern void ceph_osdc_put_event(struct ceph_osd_event *event);

net/ceph/osd_client.c +8 -4

index aa1c5c46..590cf9c 100644
@@ -2277,7 +2277,8 @@ static void __remove_event(struct ceph_osd_event *event)
  }
 
  int ceph_osdc_create_event(struct ceph_osd_client *osdc,
-			   void (*event_cb)(u64, u64, u8, void *, void *, int),
+			   void (*event_cb)(u64, u64, u8, s32, u64, void *,
+					    void *, u32),
  			   void *data, struct ceph_osd_event **pevent)
  {
  	struct ceph_osd_event *event;

@@ -2327,10 +2328,12 @@ static void do_event_work(struct work_struct *work)
  	u64 ver = event_work->ver;
  	u64 notify_id = event_work->notify_id;
  	u8 opcode = event_work->opcode;
+	s32 return_code = event_work->return_code;
+	u64 notifier_gid = event_work->notifier_gid;
 
  	dout("do_event_work completing %p\n", event);
-	event->cb(ver, notify_id, opcode, event->data, event_work->payload,
-		  event_work->payload_len);
+	event->cb(ver, notify_id, opcode, return_code, notifier_gid,
+		  event->data, event_work->payload, event_work->payload_len);
  	dout("do_event_work completed %p\n", event);
  	ceph_osdc_put_event(event);
  	kfree(event_work);

@@ -2345,9 +2348,10 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  {
  	void *p, *end, *payload = NULL;
  	u8 proto_ver;
-	u64 cookie, ver, notify_id;
+	u64 cookie, ver, notify_id, notifier_gid = 0;
  	u8 opcode;
  	u32 payload_len = 0;
+	s32 return_code = 0;
  	struct ceph_osd_event *event;
  	struct ceph_osd_event_work *event_work;
 

@@ -2365,8 +2369,15 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  		if (end - p < payload_len)
  			goto bad;

net/ceph/osd_client.c +4 -2

  	spin_lock(&osdc->event_lock);
  	event = __find_event(osdc, cookie);
  	if (event) {

@@ -2374,8 +2385,8 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  		get_event(event);
  	}
  	spin_unlock(&osdc->event_lock);
-	dout("handle_watch_notify cookie %lld ver %lld event %p notify id %llu payload len %u\n",
-	     cookie, ver, event, notify_id, payload_len);
+	dout("handle_watch_notify cookie %lld ver %lld event %p notify id %llu payload len %u return code %d notifier gid %llu\n",
+	     cookie, ver, event, notify_id, payload_len, return_code, notifier_gid);
  	if (event) {
  		event_work = kmalloc(sizeof(*event_work), GFP_NOIO);
  		if (!event_work) {

@@ -2388,6 +2399,8 @@ static void handle_watch_notify(struct ceph_osd_client *osdc,
  		event_work->ver = ver;
  		event_work->notify_id = notify_id;
  		event_work->opcode = opcode;
+		event_work->return_code = return_code;
+		event_work->notifier_gid = notifier_gid;
  		event_work->payload = payload;
  		event_work->payload_len = payload_len;
 

From: Mike Christie <[email protected]>

This syncs the ceph_osd_op struct with the current version of ceph where the watch struct has been updated to support more ops and the notify-ack support has been broken out of the watch struct.

Ceph commits
1a82cc3926fc7bc4cfbdd2fd4dfee8660d5107a1
2288f318e1b1f6a1c42b185fc1b4c41f23995247
73720130c34424bf1fe36058ebe8da66976f40fb

It still has us use the legacy watch op for now. I will add support later. It is mostly a prepartion patch for more advanced notify support.

Questions:

1. Should linger also be set for CEPH_OSD_WATCH_OP_RECONNECT?
2. Not sure what watch.gen is used for. Is that for our internal use or does the osd do something with it.

djf: removed changes to rbd.c for SCSI

Signed-off-by Mike Christie <[email protected]>

---
  drivers/block/rbd.c             | 19 +++++++-----
  include/linux/ceph/osd_client.h | 23 +++++++++++----
  include/linux/ceph/rados.h      | 24 +++++++++++++--
  net/ceph/osd_client.c           | 65 ++++++++++++++++++++++++++++++++++++-----
  4 files changed, 109 insertions(+), 22 deletions(-)

drivers/block/rbd.c +11 -8

index 65421eb..ed170b1 100644
@@ -3089,8 +3089,8 @@ static int rbd_obj_notify_ack_sync(struct rbd_device *rbd_dev, u64 notify_id)
  	if (!obj_request->osd_req)
  		goto out;
 
-	osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
-					notify_id, 0, 0);
+	osd_req_op_watch_init(obj_request->osd_req, 0,
+			      CEPH_OSD_OP_NOTIFY_ACK, 0, notify_id);
  	rbd_osd_req_format_read(obj_request);
 
  	ret = rbd_obj_request_submit(osdc, obj_request);

@@ -3138,7 +3138,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code,
   */
  static struct rbd_obj_request *rbd_obj_watch_request_helper(
  						struct rbd_device *rbd_dev,
-						bool watch)
+						u8 watch_opcode)
  {
  	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
  	struct ceph_options *opts = osdc->client->options;

@@ -3158,10 +3158,11 @@ static struct rbd_obj_request *rbd_obj_watch_request_helper(
  	}
 
  	osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
-			      rbd_dev->watch_event->cookie, 0, watch);
+			      watch_opcode, rbd_dev->watch_event->cookie);
  	rbd_osd_req_format_write(obj_request);
 
-	if (watch)
+	if (watch_opcode == CEPH_OSD_WATCH_OP_LEGACY_WATCH ||
+	    watch_opcode == CEPH_OSD_WATCH_OP_WATCH)
  		ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
 
  	ret = rbd_obj_request_submit(osdc, obj_request);

@@ -3174,7 +3175,7 @@ static struct rbd_obj_request *rbd_obj_watch_request_helper(
 
  	ret = obj_request->result;
  	if (ret) {
-		if (watch)
+		if (watch_opcode != CEPH_OSD_WATCH_OP_UNWATCH)
  			rbd_obj_request_end(obj_request);
  		goto out;
  	}

@@ -3203,7 +3204,8 @@ static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev)
  	if (ret < 0)
  		return ret;
 
-	obj_request = rbd_obj_watch_request_helper(rbd_dev, true);
+	obj_request = rbd_obj_watch_request_helper(rbd_dev,
+						CEPH_OSD_WATCH_OP_LEGACY_WATCH);
  	if (IS_ERR(obj_request)) {
  		ceph_osdc_cancel_event(rbd_dev->watch_event);
  		rbd_dev->watch_event = NULL;

@@ -3237,7 +3239,8 @@ static void rbd_dev_header_unwatch_sync(struct rbd_device *rbd_dev)
  	rbd_obj_request_put(rbd_dev->watch_request);
  	rbd_dev->watch_request = NULL;
 
-	obj_request = rbd_obj_watch_request_helper(rbd_dev, false);
+	obj_request = rbd_obj_watch_request_helper(rbd_dev,
+						   CEPH_OSD_WATCH_OP_UNWATCH);
  	if (!IS_ERR(obj_request))
  		rbd_obj_request_put(obj_request);
  	else

include/linux/ceph/osd_client.h +18 -5

index 1c4e472..12732d3 100644
@@ -106,11 +106,15 @@ struct ceph_osd_req_op {
  		struct {
  			u64 cookie;
  			u64 ver;
-			u32 prot_ver;
-			u32 timeout;
-			__u8 flag;
+			__u8 op;
+			u32 gen;
  		} watch;
  		struct {
+			u64 cookie;
+			struct ceph_osd_data request_data;
+			struct ceph_osd_data response_data;
+		} notify;
+		struct {
  			u64 expected_object_size;
  			u64 expected_write_size;
  		} alloc_hint;

@@ -302,7 +306,16 @@ extern void osd_req_op_cls_response_data_pages(struct ceph_osd_request *,
  					struct page **pages, u64 length,
  					u32 alignment, bool pages_from_pool,
  					bool own_pages);
-
+extern void osd_req_op_notify_request_data_pagelist(struct ceph_osd_request *,
+					unsigned int which,
+					struct ceph_pagelist *pagelist);
+extern void osd_req_op_notify_response_data_pages(struct ceph_osd_request *,
+					unsigned int which,
+					struct page **pages, u64 length,
+					u32 alignment, bool pages_from_pool,
+					bool own_pages);
+extern void osd_req_op_notify_init(struct ceph_osd_request *osd_req,
+				   unsigned int which, u16 opcode, u64 cookie);
  extern void osd_req_op_cls_init(struct ceph_osd_request *osd_req,
  					unsigned int which, u16 opcode,
  					const char *class, const char *method);

@@ -311,7 +324,7 @@ extern int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int
  				 size_t size, u8 cmp_op, u8 cmp_mode);
  extern void osd_req_op_watch_init(struct ceph_osd_request *osd_req,
  					unsigned int which, u16 opcode,
-					u64 cookie, u64 version, int flag);
+					u8 watch_opcode, u64 cookie);
  extern void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
  				       unsigned int which,
  				       u64 expected_object_size,

include/linux/ceph/rados.h +5 -0

index 2f822dc..cae82b36 100644
@@ -417,6 +417,22 @@ enum {
 
  #define RADOS_NOTIFY_VER	1
 
+enum {
+	CEPH_OSD_WATCH_OP_UNWATCH = 0,
+	CEPH_OSD_WATCH_OP_LEGACY_WATCH = 1,
+	/* note: use only ODD ids to prevent pre-giant code from
+	 * interpreting the op as UNWATCH */

include/linux/ceph/rados.h +6 -2

  /*
   * an individual object operation.  each may be accompanied by some data
   * payload

@@ -450,10 +466,14 @@ struct ceph_osd_op {
  	        } __attribute__ ((packed)) snap;
  		struct {
  			__le64 cookie;
-			__le64 ver;
-			__u8 flag;	/* 0 = unwatch, 1 = watch */
+			__le64 ver;	/* no longer used */
+			__u8 op;	/* CEPH_OSD_WATCH_OP_* */
+			__u32 gen;	/* registration generation */
  		} __attribute__ ((packed)) watch;
  		struct {
+			__le64 cookie;
+		} __attribute__ ((packed)) notify;
+		struct {
  			__le64 offset, length;
  			__le64 src_offset;
  		} __attribute__ ((packed)) clonerange;

net/ceph/osd_client.c +58 -7

index 590cf9c..74650e1 100644
@@ -243,6 +243,29 @@ void osd_req_op_cls_response_data_pages(struct ceph_osd_request *osd_req,
  }
  EXPORT_SYMBOL(osd_req_op_cls_response_data_pages);
 
+void osd_req_op_notify_response_data_pages(struct ceph_osd_request *osd_req,
+			unsigned int which, struct page **pages, u64 length,
+			u32 alignment, bool pages_from_pool, bool own_pages)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, notify, response_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_notify_response_data_pages);
+
+void osd_req_op_notify_request_data_pagelist(
+			struct ceph_osd_request *osd_req,
+			unsigned int which, struct ceph_pagelist *pagelist)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, notify, request_data);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+}
+EXPORT_SYMBOL(osd_req_op_notify_request_data_pagelist);
+
  static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
  {
  	switch (osd_data->type) {

@@ -292,6 +315,10 @@ static void osd_req_op_data_release(struct ceph_osd_request *osd_req,
  		ceph_osd_data_release(&op->cls.request_data);
  		ceph_osd_data_release(&op->cls.response_data);
  		break;
+	case CEPH_OSD_OP_NOTIFY:
+		ceph_osd_data_release(&op->notify.request_data);
+		ceph_osd_data_release(&op->notify.response_data);
+		break;
  	case CEPH_OSD_OP_SETXATTR:
  	case CEPH_OSD_OP_CMPXATTR:
  		ceph_osd_data_release(&op->xattr.osd_data);

@@ -588,9 +615,18 @@ int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int which,
  }
  EXPORT_SYMBOL(osd_req_op_xattr_init);
 
-void osd_req_op_watch_init(struct ceph_osd_request *osd_req,
-				unsigned int which, u16 opcode,
-				u64 cookie, u64 version, int flag)
+void osd_req_op_notify_init(struct ceph_osd_request *osd_req, unsigned int which,
+			    u16 opcode, u64 cookie)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which, opcode);
+
+	BUG_ON(opcode != CEPH_OSD_OP_NOTIFY);
+	op->watch.cookie = cookie;
+}
+EXPORT_SYMBOL(osd_req_op_notify_init);
+
+void osd_req_op_watch_init(struct ceph_osd_request *osd_req, unsigned int which,
+			   u16 opcode, u8 watch_opcode, u64 cookie)
  {
  	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
  						      opcode, 0);

@@ -598,9 +634,9 @@ void osd_req_op_watch_init(struct ceph_osd_request *osd_req,
  	BUG_ON(opcode != CEPH_OSD_OP_NOTIFY_ACK && opcode != CEPH_OSD_OP_WATCH);
 
  	op->watch.cookie = cookie;
-	op->watch.ver = version;
-	if (opcode == CEPH_OSD_OP_WATCH && flag)
-		op->watch.flag = (u8)1;
+	op->watch.ver = 0;
+	op->watch.op = watch_opcode;
+	op->watch.gen = 0;
  }
  EXPORT_SYMBOL(osd_req_op_watch_init);
 

@@ -708,11 +744,26 @@ static u64 osd_req_encode_op(struct ceph_osd_request *req,
  		break;
  	case CEPH_OSD_OP_STARTSYNC:
  		break;
+	case CEPH_OSD_OP_NOTIFY:
+		dst->notify.cookie = cpu_to_le64(src->notify.cookie);
+
+		osd_data = &src->notify.request_data;
+		data_length = ceph_osd_data_length(osd_data);
+		if (data_length) {
+			BUG_ON(osd_data->type == CEPH_OSD_DATA_TYPE_NONE);
+			ceph_osdc_msg_data_add(req->r_request, osd_data);
+			src->payload_len += data_length;
+			request_data_len += data_length;
+		}
+		osd_data = &src->notify.response_data;
+		ceph_osdc_msg_data_add(req->r_reply, osd_data);
+		break;
  	case CEPH_OSD_OP_NOTIFY_ACK:
  	case CEPH_OSD_OP_WATCH:
  		dst->watch.cookie = cpu_to_le64(src->watch.cookie);
  		dst->watch.ver = cpu_to_le64(src->watch.ver);
-		dst->watch.flag = src->watch.flag;
+		dst->watch.op = src->watch.op;
+		dst->watch.gen = cpu_to_le32(src->watch.gen);
  		break;
  	case CEPH_OSD_OP_SETALLOCHINT:
  		dst->alloc_hint.expected_object_size =

drivers/block/rbd.c +5 -0

+static void rbd_watch_error_cb(void *arg, u64 cookie, int err)
+{
+	struct rbd_device *rbd_dev = (struct rbd_device *)arg;
+	int ret;
+

drivers/block/rbd.c +5 -0

+	rbd_dev_refresh(rbd_dev);
+	if (ret)
+		rbd_warn(rbd_dev, "refresh failed: %d", ret);
+}
+
 /*

net/ceph/osd_client.c +0 -0

index 74650e1..d435bf2 100644
@@ -36,7 +36,13 @@ static void __unregister_linger_request(struct ceph_osd_client *osdc,
 					struct ceph_osd_request *req);

net/ceph/osd_client.c +33 -0

+                         void (*watchcb)(void *, u64, u64, u64, void *, size_t),
+                         void (*errcb)(void *, u64, int),
+                         void *data, struct ceph_osd_event **pevent)
+{
+	struct ceph_osd_event *event;
+	
+	event = __alloc_event(osdc, data);
+	if (!event)
+		return -ENOMEM;
+
+	event->watch.watchcb = watchcb;
+	event->watch.errcb = errcb;
+
+	spin_lock(&osdc->event_lock);
+	event->cookie = ++osdc->event_count;
+	__insert_event(osdc, event);
+	spin_unlock(&osdc->event_lock);
+	*pevent = event;
+	return 0;
+}
+EXPORT_SYMBOL(ceph_osdc_create_watch_event);
+
+int ceph_osdc_create_notify_event(struct ceph_osd_client *osdc,
+                                  struct ceph_osd_event **pevent)
+{
+	struct ceph_osd_event *event;
+	
+	event = __alloc_event(osdc, NULL);
+	if (!event)
+		return -ENOMEM;
+
+	init_completion(&event->notify.complete);
+
 	spin_lock(&osdc->event_lock);
 	event->cookie = ++osdc->event_count;
 	__insert_event(osdc, event);

@@ -2356,7 +2397,15 @@ int ceph_osdc_create_event(struct ceph_osd_client *osdc,
 	*pevent = event;

net/ceph/osd_client.c +52 -3

+}
+EXPORT_SYMBOL(ceph_osdc_wait_event);
 
 void ceph_osdc_cancel_event(struct ceph_osd_event *event)
 {

@@ -2376,20 +2425,79 @@ static void do_event_work(struct work_struct *work)
 	struct ceph_osd_event_work *event_work =
 		container_of(work, struct ceph_osd_event_work, work);
 	struct ceph_osd_event *event = event_work->event;
-	u64 ver = event_work->ver;
 	u64 notify_id = event_work->notify_id;
 	u8 opcode = event_work->opcode;
 	s32 return_code = event_work->return_code;
 	u64 notifier_gid = event_work->notifier_gid;
 
 	dout("do_event_work completing %p\n", event);
-	event->cb(ver, notify_id, opcode, return_code, notifier_gid,
-		  event->data, event_work->payload, event_work->payload_len);
+	if (opcode == CEPH_WATCH_EVENT_NOTIFY)
+		event->watch.watchcb(event->data, notify_id,
+		                     event->cookie, notifier_gid,
+		                     event_work->payload,
+		                     event_work->payload_len);
+	else if (opcode == CEPH_WATCH_EVENT_DISCONNECT && event->watch.errcb)
+		event->watch.errcb(event->data, event->cookie, return_code);
 	dout("do_event_work completed %p\n", event);
 	ceph_osdc_put_event(event);
 	kfree(event_work);
 }
 
+static void __do_event(struct ceph_osd_client *osdc, u8 opcode,
+                       u64 cookie, u64 notify_id, u32 payload_len,
+                       void *payload, s32 return_code, u64 notifier_gid,
+                       struct ceph_msg_data *data)
+{
+	struct ceph_osd_event *event;
+	struct ceph_osd_event_work *event_work;
+
+	spin_lock(&osdc->event_lock);
+	event = __find_event(osdc, cookie);
+	if (event)
+		get_event(event);
+	spin_unlock(&osdc->event_lock);
+
+	dout("handle_watch_notify cookie %lld event %p notify id %llu payload "
+	     "len %u return code %d notifier gid %llu\n",
+             cookie, event, notify_id, payload_len, return_code, notifier_gid);
+	switch(opcode) {
+		case CEPH_WATCH_EVENT_NOTIFY:
+		case CEPH_WATCH_EVENT_DISCONNECT:
+			if (event) {
+				event_work = kmalloc(sizeof(*event_work),
+				                     GFP_NOIO);
+				if (!event_work) {
+					pr_err("couldn't allocate event_work\n");
+					ceph_osdc_put_event(event);
+					return;
+				}
+				INIT_WORK(&event_work->work, do_event_work);
+				event_work->event = event;
+				event_work->notify_id = notify_id;
+				event_work->opcode = opcode;
+				event_work->return_code = return_code;
+				event_work->notifier_gid = notifier_gid;
+				event_work->payload = payload;
+				event_work->payload_len = payload_len;
+
+				queue_work(osdc->notify_wq, &event_work->work);
+			}
+			break;
+		case CEPH_WATCH_EVENT_NOTIFY_COMPLETE:
+			if (event) {
+				event->notify.notify_data = data;

From: "Mike Christie" <[email protected]>
To: "Douglas Fuller" <[email protected]>, [email protected]
Sent: Tuesday, June 16, 2015 10:58:07 AM
Subject: Re: [PATCH 4/6] osd_client, rbd: update event interface for watch/notify2

Quoted 5 lines · Douglas Fuller

drivers/block/rbd.c +5 -0

+static void rbd_watch_error_cb(void *arg, u64 cookie, int err)
+{
+	struct rbd_device *rbd_dev = (struct rbd_device *)arg;
+	int ret;
+

drivers/block/rbd.c static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code, · line 3149

Quoted 10 lines

drivers/block/rbd.c +10 -0

+	dout("%s: watch error %d on cookie %llu\n", rbd_dev->header_name,
+		err, cookie);
+	rbd_warn(rbd_dev, "%s: watch error %d on cookie %llu\n",
+	         rbd_dev->header_name, err, cookie);
+
+	/* reset watch */
+	rbd_dev_refresh(rbd_dev);
+	rbd_dev_header_unwatch_sync(rbd_dev);
+	ret = rbd_dev_header_watch_sync(rbd_dev);
+	BUG_ON(ret); /* XXX: was the image deleted? can we be more graceful? */

Is this for debugging only? BUG()/BUG_ON() can kill the system. We normally use it for cases where proceeding might cause something like data corruption or where we want to catch programming bugs early on like passing incorrect args to a function.

The other caller if this function does not escalate like this function. Are you sure you need to here? The code below will not run if we BUG above, so if you did want to BUG, you would want to move the rbd_warn before it.

Change unused ceph_osd_event structure to refer to pending watch/notify2 messages. Watch events include the separate watch and watch error callbacks used for watch/notify2. Update rbd to use separate watch and watch error callbacks via the new watch event.

Signed-off-by Douglas Fuller <[email protected]>

---
  drivers/block/rbd.c             |  41 +++++++---
  include/linux/ceph/osd_client.h |  27 +++++--
  net/ceph/osd_client.c           | 175 +++++++++++++++++++++++++++++-----------
  3 files changed, 179 insertions(+), 64 deletions(-)

drivers/block/rbd.c +13 -7

index ed170b1..20b3b23 100644
@@ -427,6 +427,8 @@ static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
  				       size_t count);
  static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping);
  static void rbd_spec_put(struct rbd_spec *spec);
+static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev);
+static void rbd_dev_header_unwatch_sync(struct rbd_device *rbd_dev);
 
  static int rbd_dev_id_to_minor(int dev_id)
  {

@@ -3103,19 +3105,17 @@ out:
  	return ret;
  }
 
-static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code,
-			 u64 notifier_gid, void *data, void *payload,
-			 u32 payload_len)
+static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie, u64 notifier_id,
+                        void *data, size_t data_len)
  {
-	struct rbd_device *rbd_dev = (struct rbd_device *)data;
+	struct rbd_device *rbd_dev = (struct rbd_device *)arg;
  	int ret;
 
  	if (!rbd_dev)
  		return;
 
-	dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
-		rbd_dev->header_name, (unsigned long long)notify_id,
-		(unsigned int)opcode);
+	dout("%s: \"%s\" notify_id %llu bl len %lu\n", __func__,
+	    rbd_dev->header_name, (unsigned long long)notify_id, data_len);
 
  	/*
  	 * Until adequate refresh error handling is in place, there is

@@ -3132,6 +3132,26 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code,
  		rbd_warn(rbd_dev, "notify_ack ret %d", ret);
  }
 
+static void rbd_watch_error_cb(void *arg, u64 cookie, int err)
+{
+	struct rbd_device *rbd_dev = (struct rbd_device *)arg;
+	int ret;
+
+	dout("%s: watch error %d on cookie %llu\n", rbd_dev->header_name,

Quoted 16 lines · Douglas Fuller

drivers/block/rbd.c +11 -0

@@ -3132,6 +3132,26 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code,
 		rbd_warn(rbd_dev, "notify_ack ret %d", ret);
 }
 
+static void rbd_watch_error_cb(void *arg, u64 cookie, int err)
+{
+	struct rbd_device *rbd_dev = (struct rbd_device *)arg;
+	int ret;
+
+	dout("%s: watch error %d on cookie %llu\n", rbd_dev->header_name,
+		err, cookie);
+	rbd_warn(rbd_dev, "%s: watch error %d on cookie %llu\n",
+	         rbd_dev->header_name, err, cookie);
+
+	/* reset watch */

drivers/block/rbd.c static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code, · line 3150

Quoted 5 lines

drivers/block/rbd.c +5 -0

+	rbd_dev_refresh(rbd_dev);
+	rbd_dev_header_unwatch_sync(rbd_dev);
+	ret = rbd_dev_header_watch_sync(rbd_dev);
+	BUG_ON(ret); /* XXX: was the image deleted? can we be more graceful? */
+	rbd_dev_refresh(rbd_dev);

Why refresh before and after unwatching? Only the second one seems necessary.

Quoted 20 lines · Josh Durgin

Quoted 16 lines · Douglas Fuller

drivers/block/rbd.c +11 -0

@@ -3132,6 +3132,26 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code,
             rbd_warn(rbd_dev, "notify_ack ret %d", ret);
 }
 
+static void rbd_watch_error_cb(void *arg, u64 cookie, int err)
+{
+    struct rbd_device *rbd_dev = (struct rbd_device *)arg;
+    int ret;
+
+    dout("%s: watch error %d on cookie %llu\n", rbd_dev->header_name,
+            err, cookie);
+    rbd_warn(rbd_dev, "%s: watch error %d on cookie %llu\n",
+             rbd_dev->header_name, err, cookie);
+
+    /* reset watch */

Quoted 8 lines

drivers/block/rbd.c static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, s32 return_code, · line 3150

Quoted 5 lines

drivers/block/rbd.c +5 -0

+    rbd_dev_refresh(rbd_dev);
+    rbd_dev_header_unwatch_sync(rbd_dev);
+    ret = rbd_dev_header_watch_sync(rbd_dev);
+    BUG_ON(ret); /* XXX: was the image deleted? can we be more graceful? */
+    rbd_dev_refresh(rbd_dev);

Why refresh before and after unwatching? Only the second one seems necessary.

The first one isn’t strictly necessary; I can remove it if you want.

If we get a watch error, we may very well have a situation in which we need to stop I/O to the device because the underlying image has been deleted or its features have changed. We don’t actually do that yet (we just print a warning message), but the extra refresh was to handle that case early, even before we bothered trying to re-establish the watch.--

net/ceph/osd_client.c +1 -0

+	}
 
 	__do_event(osdc, opcode, cookie, notify_id, payload_len, payload,
 		return_code, notifier_gid, data);

@@ -3061,7 +3078,23 @@ static struct ceph_msg *alloc_msg(struct ceph_connection *con,
 	switch (type) {

net/ceph/osd_client.c +10 -0

+				osd_data.type = CEPH_OSD_DATA_TYPE_PAGES;
+				osd_data.pages = pages;
+				osd_data.length = len;
+				osd_data.alignment = 0;
+				osd_data.pages_from_pool = false;
+				osd_data.own_pages = false;
+				ceph_osdc_msg_data_add(m, &osd_data);
+			}
+			return m;
+		}
 	case CEPH_MSG_OSD_OPREPLY:
 		return get_reply(con, hdr, skip);
 	default:

From: "Mike Christie" <[email protected]>
To: "Douglas Fuller" <[email protected]>, [email protected]
Sent: Tuesday, June 16, 2015 11:26:43 AM
Subject: Re: [PATCH 5/6] osd_client: add support for notify payloads via notify event

Quoted 5 lines · Douglas Fuller

net/ceph/osd_client.c +0 -0

@@ -2533,8 +2548,10 @@ static void handle_watch_notify(struct
 ceph_osd_client *osdc,
 	if (msg->hdr.version >= 2)
 		ceph_decode_32_safe(&p, end, return_code, bad);
 

net/ceph/osd_client.c static void handle_watch_notify(struct ceph_osd_client *osdc, · line 2553

Quoted 4 lines

net/ceph/osd_client.c +2 -1

-	if (msg->hdr.version >= 3)
+	if (msg->hdr.version >= 3) {
 		ceph_decode_32_safe(&p, end, notifier_gid, bad);
+		data = list_first_entry(&msg->data, struct ceph_msg_data, links);

It's not completely clear how/who can use this data. Would rbd be calling ceph_osdc_create_notify_event/ceph_osdc_create_notify_event, or is some libceph code (net/ceph)?

If it's rbd, is it supposed to be digging into ceph_msg_data structs? Did we want to pass it a pagelist or CEPH_OSD_DATA_TYPE_PAGES type of pages array?

static int ceph_oloc_decode(void **p, void *end,

net/ceph/osd_client.c +1 -1

 			    struct ceph_object_locator *oloc)
 {

@@ -2795,6 +2889,7 @@ int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
 	osdc->num_requests = 0;
 	INIT_DELAYED_WORK(&osdc->timeout_work, handle_timeout);
 	INIT_DELAYED_WORK(&osdc->osds_timeout_work, handle_osds_timeout);
+	INIT_DELAYED_WORK(&osdc->linger_ping_work, handle_linger_ping);
 	spin_lock_init(&osdc->event_lock);
 	osdc->event_tree = RB_ROOT;
 	osdc->event_count = 0;

@@ -3079,12 +3174,15 @@ static struct ceph_msg *alloc_msg(struct ceph_connection *con,
 	case CEPH_MSG_OSD_MAP:
 	case CEPH_MSG_WATCH_NOTIFY:
 		{
-			struct ceph_msg *m = ceph_msg_new(type, front, GFP_NOFS, false);