diff --git a/Documentation/ABI/testing/sysfs-bus-rbd b/Documentation/ABI/testing/sysfs-bus-rbd
index 90a87e2a572ba47b8549c182facfc3407f2793bd..fa72ccb2282e77c879c0a7a135f6d86828a143cc 100644
--- a/Documentation/ABI/testing/sysfs-bus-rbd
+++ b/Documentation/ABI/testing/sysfs-bus-rbd
@@ -1,6 +1,6 @@
 What:		/sys/bus/rbd/
 Date:		November 2010
-Contact:	Yehuda Sadeh <yehuda@hq.newdream.net>,
+Contact:	Yehuda Sadeh <yehuda@newdream.net>,
 		Sage Weil <sage@newdream.net>
 Description:
 
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index e1e38b11f48ae3b60f15a27f0242b4b9c100dde5..16dc3645291cd7bbb3eab203b83dde68939b61d7 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -31,6 +31,7 @@
 #include <linux/ceph/osd_client.h>
 #include <linux/ceph/mon_client.h>
 #include <linux/ceph/decode.h>
+#include <linux/parser.h>
 
 #include <linux/kernel.h>
 #include <linux/device.h>
@@ -54,6 +55,8 @@
 
 #define DEV_NAME_LEN		32
 
+#define RBD_NOTIFY_TIMEOUT_DEFAULT 10
+
 /*
  * block device image metadata (in-memory version)
  */
@@ -71,6 +74,12 @@ struct rbd_image_header {
 
 	char *snap_names;
 	u64 *snap_sizes;
+
+	u64 obj_version;
+};
+
+struct rbd_options {
+	int	notify_timeout;
 };
 
 /*
@@ -78,6 +87,7 @@ struct rbd_image_header {
  */
 struct rbd_client {
 	struct ceph_client	*client;
+	struct rbd_options	*rbd_opts;
 	struct kref		kref;
 	struct list_head	node;
 };
@@ -124,6 +134,9 @@ struct rbd_device {
 	char			pool_name[RBD_MAX_POOL_NAME_LEN];
 	int			poolid;
 
+	struct ceph_osd_event   *watch_event;
+	struct ceph_osd_request *watch_request;
+
 	char                    snap_name[RBD_MAX_SNAP_NAME_LEN];
 	u32 cur_snap;	/* index+1 of current snapshot within snap context
 			   0 - for the head */
@@ -177,6 +190,8 @@ static void rbd_put_dev(struct rbd_device *rbd_dev)
 	put_device(&rbd_dev->dev);
 }
 
+static int __rbd_update_snaps(struct rbd_device *rbd_dev);
+
 static int rbd_open(struct block_device *bdev, fmode_t mode)
 {
 	struct gendisk *disk = bdev->bd_disk;
@@ -211,7 +226,8 @@ static const struct block_device_operations rbd_bd_ops = {
  * Initialize an rbd client instance.
  * We own *opt.
  */
-static struct rbd_client *rbd_client_create(struct ceph_options *opt)
+static struct rbd_client *rbd_client_create(struct ceph_options *opt,
+					    struct rbd_options *rbd_opts)
 {
 	struct rbd_client *rbdc;
 	int ret = -ENOMEM;
@@ -233,6 +249,8 @@ static struct rbd_client *rbd_client_create(struct ceph_options *opt)
 	if (ret < 0)
 		goto out_err;
 
+	rbdc->rbd_opts = rbd_opts;
+
 	spin_lock(&node_lock);
 	list_add_tail(&rbdc->node, &rbd_client_list);
 	spin_unlock(&node_lock);
@@ -266,6 +284,59 @@ static struct rbd_client *__rbd_client_find(struct ceph_options *opt)
 	return NULL;
 }
 
+/*
+ * mount options
+ */
+enum {
+	Opt_notify_timeout,
+	Opt_last_int,
+	/* int args above */
+	Opt_last_string,
+	/* string args above */
+};
+
+static match_table_t rbdopt_tokens = {
+	{Opt_notify_timeout, "notify_timeout=%d"},
+	/* int args above */
+	/* string args above */
+	{-1, NULL}
+};
+
+static int parse_rbd_opts_token(char *c, void *private)
+{
+	struct rbd_options *rbdopt = private;
+	substring_t argstr[MAX_OPT_ARGS];
+	int token, intval, ret;
+
+	token = match_token((char *)c, rbdopt_tokens, argstr);
+	if (token < 0)
+		return -EINVAL;
+
+	if (token < Opt_last_int) {
+		ret = match_int(&argstr[0], &intval);
+		if (ret < 0) {
+			pr_err("bad mount option arg (not int) "
+			       "at '%s'\n", c);
+			return ret;
+		}
+		dout("got int token %d val %d\n", token, intval);
+	} else if (token > Opt_last_int && token < Opt_last_string) {
+		dout("got string token %d val %s\n", token,
+		     argstr[0].from);
+	} else {
+		dout("got token %d\n", token);
+	}
+
+	switch (token) {
+	case Opt_notify_timeout:
+		rbdopt->notify_timeout = intval;
+		break;
+	default:
+		BUG_ON(token);
+	}
+	return 0;
+}
+
 /*
  * Get a ceph client with specific addr and configuration, if one does
  * not exist create it.
@@ -276,11 +347,18 @@ static int rbd_get_client(struct rbd_device *rbd_dev, const char *mon_addr,
 	struct rbd_client *rbdc;
 	struct ceph_options *opt;
 	int ret;
+	struct rbd_options *rbd_opts;
+
+	rbd_opts = kzalloc(sizeof(*rbd_opts), GFP_KERNEL);
+	if (!rbd_opts)
+		return -ENOMEM;
+
+	rbd_opts->notify_timeout = RBD_NOTIFY_TIMEOUT_DEFAULT;
 
 	ret = ceph_parse_options(&opt, options, mon_addr,
-				 mon_addr + strlen(mon_addr), NULL, NULL);
+				 mon_addr + strlen(mon_addr), parse_rbd_opts_token, rbd_opts);
 	if (ret < 0)
-		return ret;
+		goto done_err;
 
 	spin_lock(&node_lock);
 	rbdc = __rbd_client_find(opt);
@@ -296,13 +374,18 @@ static int rbd_get_client(struct rbd_device *rbd_dev, const char *mon_addr,
 	}
 	spin_unlock(&node_lock);
 
-	rbdc = rbd_client_create(opt);
-	if (IS_ERR(rbdc))
-		return PTR_ERR(rbdc);
+	rbdc = rbd_client_create(opt, rbd_opts);
+	if (IS_ERR(rbdc)) {
+		ret = PTR_ERR(rbdc);
+		goto done_err;
+	}
 
 	rbd_dev->rbd_client = rbdc;
 	rbd_dev->client = rbdc->client;
 	return 0;
+done_err:
+	kfree(rbd_opts);
+	return ret;
 }
 
 /*
@@ -318,6 +401,7 @@ static void rbd_client_release(struct kref *kref)
 	spin_unlock(&node_lock);
 
 	ceph_destroy_client(rbdc->client);
+	kfree(rbdc->rbd_opts);
 	kfree(rbdc);
 }
 
@@ -666,7 +750,9 @@ static int rbd_do_request(struct request *rq,
 			  struct ceph_osd_req_op *ops,
 			  int num_reply,
 			  void (*rbd_cb)(struct ceph_osd_request *req,
-					 struct ceph_msg *msg))
+					 struct ceph_msg *msg),
+			  struct ceph_osd_request **linger_req,
+			  u64 *ver)
 {
 	struct ceph_osd_request *req;
 	struct ceph_file_layout *layout;
@@ -729,12 +815,20 @@ static int rbd_do_request(struct request *rq,
 				req->r_oid, req->r_oid_len);
 	up_read(&header->snap_rwsem);
 
+	if (linger_req) {
+		ceph_osdc_set_request_linger(&dev->client->osdc, req);
+		*linger_req = req;
+	}
+
 	ret = ceph_osdc_start_request(&dev->client->osdc, req, false);
 	if (ret < 0)
 		goto done_err;
 
 	if (!rbd_cb) {
 		ret = ceph_osdc_wait_request(&dev->client->osdc, req);
+		if (ver)
+			*ver = le64_to_cpu(req->r_reassert_version.version);
+		dout("reassert_ver=%lld\n", le64_to_cpu(req->r_reassert_version.version));
 		ceph_osdc_put_request(req);
 	}
 	return ret;
@@ -789,6 +883,11 @@ static void rbd_req_cb(struct ceph_osd_request *req, struct ceph_msg *msg)
 	kfree(req_data);
 }
 
+static void rbd_simple_req_cb(struct ceph_osd_request *req, struct ceph_msg *msg)
+{
+	ceph_osdc_put_request(req);
+}
+
 /*
  * Do a synchronous ceph osd operation
  */
@@ -801,7 +900,9 @@ static int rbd_req_sync_op(struct rbd_device *dev,
 			   int num_reply,
 			   const char *obj,
 			   u64 ofs, u64 len,
-			   char *buf)
+			   char *buf,
+			   struct ceph_osd_request **linger_req,
+			   u64 *ver)
 {
 	int ret;
 	struct page **pages;
@@ -833,7 +934,8 @@ static int rbd_req_sync_op(struct rbd_device *dev,
 			  flags,
 			  ops,
 			  2,
-			  NULL);
+			  NULL,
+			  linger_req, ver);
 	if (ret < 0)
 		goto done_ops;
 
@@ -893,7 +995,7 @@ static int rbd_do_op(struct request *rq,
 			     flags,
 			     ops,
 			     num_reply,
-			     rbd_req_cb);
+			     rbd_req_cb, 0, NULL);
 done:
 	kfree(seg_name);
 	return ret;
@@ -940,18 +1042,174 @@ static int rbd_req_sync_read(struct rbd_device *dev,
 			  u64 snapid,
 			  const char *obj,
 			  u64 ofs, u64 len,
-			  char *buf)
+			  char *buf,
+			  u64 *ver)
 {
 	return rbd_req_sync_op(dev, NULL,
 			       (snapid ? snapid : CEPH_NOSNAP),
 			       CEPH_OSD_OP_READ,
 			       CEPH_OSD_FLAG_READ,
 			       NULL,
-			       1, obj, ofs, len, buf);
+			       1, obj, ofs, len, buf, NULL, ver);
 }
 
 /*
- * Request sync osd read
+ * Request sync osd watch
+ */
+static int rbd_req_sync_notify_ack(struct rbd_device *dev,
+				   u64 ver,
+				   u64 notify_id,
+				   const char *obj)
+{
+	struct ceph_osd_req_op *ops;
+	struct page **pages = NULL;
+	int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_NOTIFY_ACK, 0);
+	if (ret < 0)
+		return ret;
+
+	ops[0].watch.ver = cpu_to_le64(dev->header.obj_version);
+	ops[0].watch.cookie = notify_id;
+	ops[0].watch.flag = 0;
+
+	ret = rbd_do_request(NULL, dev, NULL, CEPH_NOSNAP,
+			  obj, 0, 0, NULL,
+			  pages, 0,
+			  CEPH_OSD_FLAG_READ,
+			  ops,
+			  1,
+			  rbd_simple_req_cb, 0, NULL);
+
+	rbd_destroy_ops(ops);
+	return ret;
+}
+
+static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
+{
+	struct rbd_device *dev = (struct rbd_device *)data;
+	if (!dev)
+		return;
+
+	dout("rbd_watch_cb %s notify_id=%lld opcode=%d\n", dev->obj_md_name,
+		notify_id, (int)opcode);
+	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+	__rbd_update_snaps(dev);
+	mutex_unlock(&ctl_mutex);
+
+	rbd_req_sync_notify_ack(dev, ver, notify_id, dev->obj_md_name);
+}
+
+/*
+ * Request sync osd watch
+ */
+static int rbd_req_sync_watch(struct rbd_device *dev,
+			      const char *obj,
+			      u64 ver)
+{
+	struct ceph_osd_req_op *ops;
+	struct ceph_osd_client *osdc = &dev->client->osdc;
+
+	int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_WATCH, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = ceph_osdc_create_event(osdc, rbd_watch_cb, 0,
+				     (void *)dev, &dev->watch_event);
+	if (ret < 0)
+		goto fail;
+
+	ops[0].watch.ver = cpu_to_le64(ver);
+	ops[0].watch.cookie = cpu_to_le64(dev->watch_event->cookie);
+	ops[0].watch.flag = 1;
+
+	ret = rbd_req_sync_op(dev, NULL,
+			      CEPH_NOSNAP,
+			      0,
+			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
+			      ops,
+			      1, obj, 0, 0, NULL,
+			      &dev->watch_request, NULL);
+
+	if (ret < 0)
+		goto fail_event;
+
+	rbd_destroy_ops(ops);
+	return 0;
+
+fail_event:
+	ceph_osdc_cancel_event(dev->watch_event);
+	dev->watch_event = NULL;
+fail:
+	rbd_destroy_ops(ops);
+	return ret;
+}
+
+struct rbd_notify_info {
+	struct rbd_device *dev;
+};
+
+static void rbd_notify_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
+{
+	struct rbd_device *dev = (struct rbd_device *)data;
+	if (!dev)
+		return;
+
+	dout("rbd_notify_cb %s notify_id=%lld opcode=%d\n", dev->obj_md_name,
+		notify_id, (int)opcode);
+}
+
+/*
+ * Request sync osd notify
+ */
+static int rbd_req_sync_notify(struct rbd_device *dev,
+		          const char *obj)
+{
+	struct ceph_osd_req_op *ops;
+	struct ceph_osd_client *osdc = &dev->client->osdc;
+	struct ceph_osd_event *event;
+	struct rbd_notify_info info;
+	int payload_len = sizeof(u32) + sizeof(u32);
+	int ret;
+
+	ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_NOTIFY, payload_len);
+	if (ret < 0)
+		return ret;
+
+	info.dev = dev;
+
+	ret = ceph_osdc_create_event(osdc, rbd_notify_cb, 1,
+				     (void *)&info, &event);
+	if (ret < 0)
+		goto fail;
+
+	ops[0].watch.ver = 1;
+	ops[0].watch.flag = 1;
+	ops[0].watch.cookie = event->cookie;
+	ops[0].watch.prot_ver = RADOS_NOTIFY_VER;
+	ops[0].watch.timeout = 12;
+
+	ret = rbd_req_sync_op(dev, NULL,
+			       CEPH_NOSNAP,
+			       0,
+			       CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
+			       ops,
+			       1, obj, 0, 0, NULL, NULL, NULL);
+	if (ret < 0)
+		goto fail_event;
+
+	ret = ceph_osdc_wait_event(event, CEPH_OSD_TIMEOUT_DEFAULT);
+	dout("ceph_osdc_wait_event returned %d\n", ret);
+	rbd_destroy_ops(ops);
+	return 0;
+
+fail_event:
+	ceph_osdc_cancel_event(event);
+fail:
+	rbd_destroy_ops(ops);
+	return ret;
+}
+
+/*
+ * Request sync osd rollback
  */
 static int rbd_req_sync_rollback_obj(struct rbd_device *dev,
 				     u64 snapid,
@@ -969,13 +1227,10 @@ static int rbd_req_sync_rollback_obj(struct rbd_device *dev,
 			       0,
 			       CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
 			       ops,
-			       1, obj, 0, 0, NULL);
+			       1, obj, 0, 0, NULL, NULL, NULL);
 
 	rbd_destroy_ops(ops);
 
-	if (ret < 0)
-		return ret;
-
 	return ret;
 }
 
@@ -987,7 +1242,8 @@ static int rbd_req_sync_exec(struct rbd_device *dev,
 			     const char *cls,
 			     const char *method,
 			     const char *data,
-			     int len)
+			     int len,
+			     u64 *ver)
 {
 	struct ceph_osd_req_op *ops;
 	int cls_len = strlen(cls);
@@ -1010,7 +1266,7 @@ static int rbd_req_sync_exec(struct rbd_device *dev,
 			       0,
 			       CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
 			       ops,
-			       1, obj, 0, 0, NULL);
+			       1, obj, 0, 0, NULL, NULL, ver);
 
 	rbd_destroy_ops(ops);
 
@@ -1156,6 +1412,7 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
 	struct rbd_image_header_ondisk *dh;
 	int snap_count = 0;
 	u64 snap_names_len = 0;
+	u64 ver;
 
 	while (1) {
 		int len = sizeof(*dh) +
@@ -1171,7 +1428,7 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
 				       NULL, CEPH_NOSNAP,
 				       rbd_dev->obj_md_name,
 				       0, len,
-				       (char *)dh);
+				       (char *)dh, &ver);
 		if (rc < 0)
 			goto out_dh;
 
@@ -1188,6 +1445,7 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
 		}
 		break;
 	}
+	header->obj_version = ver;
 
 out_dh:
 	kfree(dh);
@@ -1205,6 +1463,7 @@ static int rbd_header_add_snap(struct rbd_device *dev,
 	u64 new_snapid;
 	int ret;
 	void *data, *data_start, *data_end;
+	u64 ver;
 
 	/* we should create a snapshot only if we're pointing at the head */
 	if (dev->cur_snap)
@@ -1227,7 +1486,7 @@ static int rbd_header_add_snap(struct rbd_device *dev,
 	ceph_encode_64_safe(&data, data_end, new_snapid, bad);
 
 	ret = rbd_req_sync_exec(dev, dev->obj_md_name, "rbd", "snap_add",
-				data_start, data - data_start);
+				data_start, data - data_start, &ver);
 
 	kfree(data_start);
 
@@ -1259,6 +1518,7 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev)
 	int ret;
 	struct rbd_image_header h;
 	u64 snap_seq;
+	int follow_seq = 0;
 
 	ret = rbd_read_header(rbd_dev, &h);
 	if (ret < 0)
@@ -1267,6 +1527,11 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev)
 	down_write(&rbd_dev->header.snap_rwsem);
 
 	snap_seq = rbd_dev->header.snapc->seq;
+	if (rbd_dev->header.total_snaps &&
+	    rbd_dev->header.snapc->snaps[0] == snap_seq)
+		/* pointing at the head, will need to follow that
+		   if head moves */
+		follow_seq = 1;
 
 	kfree(rbd_dev->header.snapc);
 	kfree(rbd_dev->header.snap_names);
@@ -1277,7 +1542,10 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev)
 	rbd_dev->header.snap_names = h.snap_names;
 	rbd_dev->header.snap_names_len = h.snap_names_len;
 	rbd_dev->header.snap_sizes = h.snap_sizes;
-	rbd_dev->header.snapc->seq = snap_seq;
+	if (follow_seq)
+		rbd_dev->header.snapc->seq = rbd_dev->header.snapc->snaps[0];
+	else
+		rbd_dev->header.snapc->seq = snap_seq;
 
 	ret = __rbd_init_snaps_header(rbd_dev);
 
@@ -1699,7 +1967,28 @@ static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
 	device_unregister(&rbd_dev->dev);
 }
 
-static ssize_t rbd_add(struct bus_type *bus, const char *buf, size_t count)
+static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
+{
+	int ret, rc;
+
+	do {
+		ret = rbd_req_sync_watch(rbd_dev, rbd_dev->obj_md_name,
+					 rbd_dev->header.obj_version);
+		if (ret == -ERANGE) {
+			mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+			rc = __rbd_update_snaps(rbd_dev);
+			mutex_unlock(&ctl_mutex);
+			if (rc < 0)
+				return rc;
+		}
+	} while (ret == -ERANGE);
+
+	return ret;
+}
+
+static ssize_t rbd_add(struct bus_type *bus,
+		       const char *buf,
+		       size_t count)
 {
 	struct ceph_osd_client *osdc;
 	struct rbd_device *rbd_dev;
@@ -1797,6 +2086,10 @@ static ssize_t rbd_add(struct bus_type *bus, const char *buf, size_t count)
 	if (rc)
 		goto err_out_bus;
 
+	rc = rbd_init_watch_dev(rbd_dev);
+	if (rc)
+		goto err_out_bus;
+
 	return count;
 
 err_out_bus:
@@ -1849,6 +2142,12 @@ static void rbd_dev_release(struct device *dev)
 	struct rbd_device *rbd_dev =
 			container_of(dev, struct rbd_device, dev);
 
+	if (rbd_dev->watch_request)
+		ceph_osdc_unregister_linger_request(&rbd_dev->client->osdc,
+						    rbd_dev->watch_request);
+	if (rbd_dev->watch_event)
+		ceph_osdc_cancel_event(rbd_dev->watch_event);
+
 	rbd_put_client(rbd_dev);
 
 	/* clean up and free blkdev */
@@ -1914,14 +2213,24 @@ static ssize_t rbd_snap_add(struct device *dev,
 	ret = rbd_header_add_snap(rbd_dev,
 				  name, GFP_KERNEL);
 	if (ret < 0)
-		goto done_unlock;
+		goto err_unlock;
 
 	ret = __rbd_update_snaps(rbd_dev);
 	if (ret < 0)
-		goto done_unlock;
+		goto err_unlock;
+
+	/* shouldn't hold ctl_mutex when notifying.. notify might
+	   trigger a watch callback that would need to get that mutex */
+	mutex_unlock(&ctl_mutex);
+
+	/* make a best effort, don't error if failed */
+	rbd_req_sync_notify(rbd_dev, rbd_dev->obj_md_name);
 
 	ret = count;
-done_unlock:
+	kfree(name);
+	return ret;
+
+err_unlock:
 	mutex_unlock(&ctl_mutex);
 	kfree(name);
 	return ret;
diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index 08f65faac1126aa7a5096ec2a7233e5fb332242b..0dba6915712becaef62b6802bb88d1a7b36ea854 100644
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -210,8 +210,6 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
 	if (!fsc->debugfs_congestion_kb)
 		goto out;
 
-	dout("a\n");
-
 	snprintf(name, sizeof(name), "../../bdi/%s",
 		 dev_name(fsc->backing_dev_info.dev));
 	fsc->debugfs_bdi =
@@ -221,7 +219,6 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
 	if (!fsc->debugfs_bdi)
 		goto out;
 
-	dout("b\n");
 	fsc->debugfs_mdsmap = debugfs_create_file("mdsmap",
 					0600,
 					fsc->client->debugfs_dir,
@@ -230,7 +227,6 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
 	if (!fsc->debugfs_mdsmap)
 		goto out;
 
-	dout("ca\n");
 	fsc->debugfs_mdsc = debugfs_create_file("mdsc",
 						0600,
 						fsc->client->debugfs_dir,
@@ -239,7 +235,6 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
 	if (!fsc->debugfs_mdsc)
 		goto out;
 
-	dout("da\n");
 	fsc->debugfs_caps = debugfs_create_file("caps",
 						   0400,
 						   fsc->client->debugfs_dir,
@@ -248,7 +243,6 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
 	if (!fsc->debugfs_caps)
 		goto out;
 
-	dout("ea\n");
 	fsc->debugfs_dentry_lru = debugfs_create_file("dentry_lru",
 					0600,
 					fsc->client->debugfs_dir,
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index ebafa65a29b6580619c75256195547a5107cb86d..1a867a3601aea88ee25c9fadf399d4a2a3472498 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -161,7 +161,7 @@ static int __dcache_readdir(struct file *filp,
 	filp->f_pos = di->offset;
 	err = filldir(dirent, dentry->d_name.name,
 		      dentry->d_name.len, di->offset,
-		      dentry->d_inode->i_ino,
+		      ceph_translate_ino(dentry->d_sb, dentry->d_inode->i_ino),
 		      dentry->d_inode->i_mode >> 12);
 
 	if (last) {
@@ -245,15 +245,17 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
 		dout("readdir off 0 -> '.'\n");
 		if (filldir(dirent, ".", 1, ceph_make_fpos(0, 0),
-			    inode->i_ino, inode->i_mode >> 12) < 0)
+			    ceph_translate_ino(inode->i_sb, inode->i_ino),
+			    inode->i_mode >> 12) < 0)
 			return 0;
 		filp->f_pos = 1;
 		off = 1;
 	}
 	if (filp->f_pos == 1) {
+		ino_t ino = filp->f_dentry->d_parent->d_inode->i_ino;
 		dout("readdir off 1 -> '..'\n");
 		if (filldir(dirent, "..", 2, ceph_make_fpos(0, 1),
-			    filp->f_dentry->d_parent->d_inode->i_ino,
+			    ceph_translate_ino(inode->i_sb, ino),
 			    inode->i_mode >> 12) < 0)
 			return 0;
 		filp->f_pos = 2;
@@ -377,7 +379,8 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		if (filldir(dirent,
 			    rinfo->dir_dname[off - fi->offset],
 			    rinfo->dir_dname_len[off - fi->offset],
-			    pos, ino, ftype) < 0) {
+			    pos,
+			    ceph_translate_ino(inode->i_sb, ino), ftype) < 0) {
 			dout("filldir stopping us...\n");
 			return 0;
 		}
@@ -1024,14 +1027,13 @@ static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 }
 
 /*
- * When a dentry is released, clear the dir I_COMPLETE if it was part
- * of the current dir gen or if this is in the snapshot namespace.
+ * Release our ceph_dentry_info.
  */
-static void ceph_dentry_release(struct dentry *dentry)
+static void ceph_d_release(struct dentry *dentry)
 {
 	struct ceph_dentry_info *di = ceph_dentry(dentry);
 
-	dout("dentry_release %p\n", dentry);
+	dout("d_release %p\n", dentry);
 	if (di) {
 		ceph_dentry_lru_del(dentry);
 		if (di->lease_session)
@@ -1256,14 +1258,14 @@ const struct inode_operations ceph_dir_iops = {
 
 const struct dentry_operations ceph_dentry_ops = {
 	.d_revalidate = ceph_d_revalidate,
-	.d_release = ceph_dentry_release,
+	.d_release = ceph_d_release,
 };
 
 const struct dentry_operations ceph_snapdir_dentry_ops = {
 	.d_revalidate = ceph_snapdir_d_revalidate,
-	.d_release = ceph_dentry_release,
+	.d_release = ceph_d_release,
 };
 
 const struct dentry_operations ceph_snap_dentry_ops = {
-	.d_release = ceph_dentry_release,
+	.d_release = ceph_d_release,
 };
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 7d0e4a82d898a83f2695eead6ffc767689ffe140..159b512d5a271379abf0bde217fd46feeb38c79b 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -564,11 +564,19 @@ static ssize_t ceph_sync_write(struct file *file, const char __user *data,
 			 * start_request so that a tid has been assigned.
 			 */
 			spin_lock(&ci->i_unsafe_lock);
-			list_add(&req->r_unsafe_item, &ci->i_unsafe_writes);
+			list_add_tail(&req->r_unsafe_item,
+				      &ci->i_unsafe_writes);
 			spin_unlock(&ci->i_unsafe_lock);
 			ceph_get_cap_refs(ci, CEPH_CAP_FILE_WR);
 		}
+		
 		ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
+		if (ret < 0 && req->r_safe_callback) {
+			spin_lock(&ci->i_unsafe_lock);
+			list_del_init(&req->r_unsafe_item);
+			spin_unlock(&ci->i_unsafe_lock);
+			ceph_put_cap_refs(ci, CEPH_CAP_FILE_WR);
+		}
 	}
 
 	if (file->f_flags & O_DIRECT)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 193bfa5e9cbd7943bcb2a8124b5fa9ed6717cac4..b54c97da1c43fd8a4d52238d469c0aa6cb904772 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -36,6 +36,13 @@ static void ceph_vmtruncate_work(struct work_struct *work);
 /*
  * find or create an inode, given the ceph ino number
  */
+static int ceph_set_ino_cb(struct inode *inode, void *data)
+{
+	ceph_inode(inode)->i_vino = *(struct ceph_vino *)data;
+	inode->i_ino = ceph_vino_to_ino(*(struct ceph_vino *)data);
+	return 0;
+}
+
 struct inode *ceph_get_inode(struct super_block *sb, struct ceph_vino vino)
 {
 	struct inode *inode;
@@ -1030,9 +1037,6 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 			dout("fill_trace doing d_move %p -> %p\n",
 			     req->r_old_dentry, dn);
 
-			/* d_move screws up d_subdirs order */
-			ceph_i_clear(dir, CEPH_I_COMPLETE);
-
 			d_move(req->r_old_dentry, dn);
 			dout(" src %p '%.*s' dst %p '%.*s'\n",
 			     req->r_old_dentry,
@@ -1044,12 +1048,15 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 			   rehashing bug in vfs_rename_dir */
 			ceph_invalidate_dentry_lease(dn);
 
-			/* take overwritten dentry's readdir offset */
-			dout("dn %p gets %p offset %lld (old offset %lld)\n",
-			     req->r_old_dentry, dn, ceph_dentry(dn)->offset,
+			/*
+			 * d_move() puts the renamed dentry at the end of
+			 * d_subdirs.  We need to assign it an appropriate
+			 * directory offset so we can behave when holding
+			 * I_COMPLETE.
+			 */
+			ceph_set_dentry_offset(req->r_old_dentry);
+			dout("dn %p gets new offset %lld\n", req->r_old_dentry, 
 			     ceph_dentry(req->r_old_dentry)->offset);
-			ceph_dentry(req->r_old_dentry)->offset =
-				ceph_dentry(dn)->offset;
 
 			dn = req->r_old_dentry;  /* use old_dentry */
 			in = dn->d_inode;
@@ -1809,7 +1816,7 @@ int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	err = ceph_do_getattr(inode, CEPH_STAT_CAP_INODE_ALL);
 	if (!err) {
 		generic_fillattr(inode, stat);
-		stat->ino = inode->i_ino;
+		stat->ino = ceph_translate_ino(inode->i_sb, inode->i_ino);
 		if (ceph_snap(inode) != CEPH_NOSNAP)
 			stat->dev = ceph_snap(inode);
 		else
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 9c5085465a63056ac493a5febe8b184163c933a6..a9e78b4a258c9adf55b7d48b8f77208619993472 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -131,6 +131,7 @@ enum {
 	Opt_rbytes,
 	Opt_norbytes,
 	Opt_noasyncreaddir,
+	Opt_ino32,
 };
 
 static match_table_t fsopt_tokens = {
@@ -150,6 +151,7 @@ static match_table_t fsopt_tokens = {
 	{Opt_rbytes, "rbytes"},
 	{Opt_norbytes, "norbytes"},
 	{Opt_noasyncreaddir, "noasyncreaddir"},
+	{Opt_ino32, "ino32"},
 	{-1, NULL}
 };
 
@@ -225,6 +227,9 @@ static int parse_fsopt_token(char *c, void *private)
 	case Opt_noasyncreaddir:
 		fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
 		break;
+	case Opt_ino32:
+		fsopt->flags |= CEPH_MOUNT_OPT_INO32;
+		break;
 	default:
 		BUG_ON(token);
 	}
@@ -288,7 +293,7 @@ static int parse_mount_options(struct ceph_mount_options **pfsopt,
         fsopt->sb_flags = flags;
         fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
 
-        fsopt->rsize = CEPH_MOUNT_RSIZE_DEFAULT;
+        fsopt->rsize = CEPH_RSIZE_DEFAULT;
         fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
 	fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
 	fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
@@ -370,7 +375,7 @@ static int ceph_show_options(struct seq_file *m, struct vfsmount *mnt)
 
 	if (fsopt->wsize)
 		seq_printf(m, ",wsize=%d", fsopt->wsize);
-	if (fsopt->rsize != CEPH_MOUNT_RSIZE_DEFAULT)
+	if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
 		seq_printf(m, ",rsize=%d", fsopt->rsize);
 	if (fsopt->congestion_kb != default_congestion_kb())
 		seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 20b907d76ae2f1be3b9e5ef4859bb1866b833c8a..619fe719968ff124771de1811b80ba165a54c2b3 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -27,6 +27,7 @@
 #define CEPH_MOUNT_OPT_DIRSTAT         (1<<4) /* `cat dirname` for stats */
 #define CEPH_MOUNT_OPT_RBYTES          (1<<5) /* dir st_bytes = rbytes */
 #define CEPH_MOUNT_OPT_NOASYNCREADDIR  (1<<7) /* no dcache readdir */
+#define CEPH_MOUNT_OPT_INO32           (1<<8) /* 32 bit inos */
 
 #define CEPH_MOUNT_OPT_DEFAULT    (CEPH_MOUNT_OPT_RBYTES)
 
@@ -35,6 +36,7 @@
 #define ceph_test_mount_opt(fsc, opt) \
 	(!!((fsc)->mount_options->flags & CEPH_MOUNT_OPT_##opt))
 
+#define CEPH_RSIZE_DEFAULT             (512*1024) /* readahead */
 #define CEPH_MAX_READDIR_DEFAULT        1024
 #define CEPH_MAX_READDIR_BYTES_DEFAULT  (512*1024)
 #define CEPH_SNAPDIRNAME_DEFAULT        ".snap"
@@ -319,6 +321,16 @@ static inline struct ceph_inode_info *ceph_inode(struct inode *inode)
 	return container_of(inode, struct ceph_inode_info, vfs_inode);
 }
 
+static inline struct ceph_fs_client *ceph_inode_to_client(struct inode *inode)
+{
+	return (struct ceph_fs_client *)inode->i_sb->s_fs_info;
+}
+
+static inline struct ceph_fs_client *ceph_sb_to_client(struct super_block *sb)
+{
+	return (struct ceph_fs_client *)sb->s_fs_info;
+}
+
 static inline struct ceph_vino ceph_vino(struct inode *inode)
 {
 	return ceph_inode(inode)->i_vino;
@@ -327,19 +339,49 @@ static inline struct ceph_vino ceph_vino(struct inode *inode)
 /*
  * ino_t is <64 bits on many architectures, blech.
  *
- * don't include snap in ino hash, at least for now.
+ *               i_ino (kernel inode)   st_ino (userspace)
+ * i386          32                     32
+ * x86_64+ino32  64                     32
+ * x86_64        64                     64
+ */
+static inline u32 ceph_ino_to_ino32(ino_t ino)
+{
+	ino ^= ino >> (sizeof(ino) * 8 - 32);
+	if (!ino)
+		ino = 1;
+	return ino;
+}
+
+/*
+ * kernel i_ino value
  */
 static inline ino_t ceph_vino_to_ino(struct ceph_vino vino)
 {
 	ino_t ino = (ino_t)vino.ino;  /* ^ (vino.snap << 20); */
 #if BITS_PER_LONG == 32
-	ino ^= vino.ino >> (sizeof(u64)-sizeof(ino_t)) * 8;
-	if (!ino)
-		ino = 1;
+	ino = ceph_ino_to_ino32(ino);
 #endif
 	return ino;
 }
 
+/*
+ * user-visible ino (stat, filldir)
+ */
+#if BITS_PER_LONG == 32
+static inline ino_t ceph_translate_ino(struct super_block *sb, ino_t ino)
+{
+	return ino;
+}
+#else
+static inline ino_t ceph_translate_ino(struct super_block *sb, ino_t ino)
+{
+	if (ceph_test_mount_opt(ceph_sb_to_client(sb), INO32))
+		ino = ceph_ino_to_ino32(ino);
+	return ino;
+}
+#endif
+
+
 /* for printf-style formatting */
 #define ceph_vinop(i) ceph_inode(i)->i_vino.ino, ceph_inode(i)->i_vino.snap
 
@@ -428,13 +470,6 @@ static inline loff_t ceph_make_fpos(unsigned frag, unsigned off)
 	return ((loff_t)frag << 32) | (loff_t)off;
 }
 
-static inline int ceph_set_ino_cb(struct inode *inode, void *data)
-{
-	ceph_inode(inode)->i_vino = *(struct ceph_vino *)data;
-	inode->i_ino = ceph_vino_to_ino(*(struct ceph_vino *)data);
-	return 0;
-}
-
 /*
  * caps helpers
  */
@@ -503,15 +538,6 @@ extern void ceph_reservation_status(struct ceph_fs_client *client,
 				    int *total, int *avail, int *used,
 				    int *reserved, int *min);
 
-static inline struct ceph_fs_client *ceph_inode_to_client(struct inode *inode)
-{
-	return (struct ceph_fs_client *)inode->i_sb->s_fs_info;
-}
-
-static inline struct ceph_fs_client *ceph_sb_to_client(struct super_block *sb)
-{
-	return (struct ceph_fs_client *)sb->s_fs_info;
-}
 
 
 /*
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 09dcc0c2ffd52bd8d69d04ace79a00ca6d909f5c..b8e995fbd8670a2c7303d590432dc2a5e1f62b0d 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -136,9 +136,18 @@ struct ceph_dir_layout {
 
 
 /* osd */
-#define CEPH_MSG_OSD_MAP          41
-#define CEPH_MSG_OSD_OP           42
-#define CEPH_MSG_OSD_OPREPLY      43
+#define CEPH_MSG_OSD_MAP                41
+#define CEPH_MSG_OSD_OP                 42
+#define CEPH_MSG_OSD_OPREPLY            43
+#define CEPH_MSG_WATCH_NOTIFY           44
+
+
+/* watch-notify operations */
+enum {
+  WATCH_NOTIFY				= 1, /* notifying watcher */
+  WATCH_NOTIFY_COMPLETE			= 2, /* notifier notified when done */
+};
+
 
 /* pool operations */
 enum {
@@ -213,8 +222,10 @@ struct ceph_client_mount {
 	struct ceph_mon_request_header monhdr;
 } __attribute__ ((packed));
 
+#define CEPH_SUBSCRIBE_ONETIME    1  /* i want only 1 update after have */
+
 struct ceph_mon_subscribe_item {
-	__le64 have_version;	__le64 have;
+	__le64 have_version;    __le64 have;
 	__u8 onetime;
 } __attribute__ ((packed));
 
diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 72c72bfccb88181b8b7c480e445849bfc0c8ab28..0d2e0fffb470734d90cb1248ee9f02613764f54f 100644
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -71,7 +71,6 @@ struct ceph_options {
 #define CEPH_OSD_TIMEOUT_DEFAULT    60  /* seconds */
 #define CEPH_OSD_KEEPALIVE_DEFAULT  5
 #define CEPH_OSD_IDLE_TTL_DEFAULT    60
-#define CEPH_MOUNT_RSIZE_DEFAULT    (512*1024) /* readahead */
 
 #define CEPH_MSG_MAX_FRONT_LEN	(16*1024*1024)
 #define CEPH_MSG_MAX_DATA_LEN	(16*1024*1024)
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index a1af29648fb54be5c0b5ac1cfc62879314145d56..f88eacb111d4151dc5491797fe0e03faaadc26a9 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -32,6 +32,7 @@ struct ceph_osd {
 	struct rb_node o_node;
 	struct ceph_connection o_con;
 	struct list_head o_requests;
+	struct list_head o_linger_requests;
 	struct list_head o_osd_lru;
 	struct ceph_authorizer *o_authorizer;
 	void *o_authorizer_buf, *o_authorizer_reply_buf;
@@ -47,6 +48,8 @@ struct ceph_osd_request {
 	struct rb_node  r_node;
 	struct list_head r_req_lru_item;
 	struct list_head r_osd_item;
+	struct list_head r_linger_item;
+	struct list_head r_linger_osd;
 	struct ceph_osd *r_osd;
 	struct ceph_pg   r_pgid;
 	int              r_pg_osds[CEPH_PG_MAX_SIZE];
@@ -59,6 +62,7 @@ struct ceph_osd_request {
 	int               r_flags;     /* any additional flags for the osd */
 	u32               r_sent;      /* >0 if r_request is sending/sent */
 	int               r_got_reply;
+	int		  r_linger;
 
 	struct ceph_osd_client *r_osdc;
 	struct kref       r_kref;
@@ -74,7 +78,6 @@ struct ceph_osd_request {
 	char              r_oid[40];          /* object name */
 	int               r_oid_len;
 	unsigned long     r_stamp;            /* send OR check time */
-	bool              r_resend;           /* msg send failed, needs retry */
 
 	struct ceph_file_layout r_file_layout;
 	struct ceph_snap_context *r_snapc;    /* snap context for writes */
@@ -90,6 +93,26 @@ struct ceph_osd_request {
 	struct ceph_pagelist *r_trail;	      /* trailing part of the data */
 };
 
+struct ceph_osd_event {
+	u64 cookie;
+	int one_shot;
+	struct ceph_osd_client *osdc;
+	void (*cb)(u64, u64, u8, void *);
+	void *data;
+	struct rb_node node;
+	struct list_head osd_node;
+	struct kref kref;
+	struct completion completion;
+};
+
+struct ceph_osd_event_work {
+	struct work_struct work;
+	struct ceph_osd_event *event;
+        u64 ver;
+        u64 notify_id;
+        u8 opcode;
+};
+
 struct ceph_osd_client {
 	struct ceph_client     *client;
 
@@ -104,7 +127,10 @@ struct ceph_osd_client {
 	u64                    timeout_tid;   /* tid of timeout triggering rq */
 	u64                    last_tid;      /* tid of last request */
 	struct rb_root         requests;      /* pending requests */
-	struct list_head       req_lru;	      /* pending requests lru */
+	struct list_head       req_lru;	      /* in-flight lru */
+	struct list_head       req_unsent;    /* unsent/need-resend queue */
+	struct list_head       req_notarget;  /* map to no osd */
+	struct list_head       req_linger;    /* lingering requests */
 	int                    num_requests;
 	struct delayed_work    timeout_work;
 	struct delayed_work    osds_timeout_work;
@@ -116,6 +142,12 @@ struct ceph_osd_client {
 
 	struct ceph_msgpool	msgpool_op;
 	struct ceph_msgpool	msgpool_op_reply;
+
+	spinlock_t		event_lock;
+	struct rb_root		event_tree;
+	u64			event_count;
+
+	struct workqueue_struct	*notify_wq;
 };
 
 struct ceph_osd_req_op {
@@ -150,6 +182,13 @@ struct ceph_osd_req_op {
 	        struct {
 		        u64 snapid;
 	        } snap;
+		struct {
+			u64 cookie;
+			u64 ver;
+			__u8 flag;
+			u32 prot_ver;
+			u32 timeout;
+		} watch;
 	};
 	u32 payload_len;
 };
@@ -198,6 +237,11 @@ extern struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *,
 				      bool use_mempool, int num_reply,
 				      int page_align);
 
+extern void ceph_osdc_set_request_linger(struct ceph_osd_client *osdc,
+					 struct ceph_osd_request *req);
+extern void ceph_osdc_unregister_linger_request(struct ceph_osd_client *osdc,
+						struct ceph_osd_request *req);
+
 static inline void ceph_osdc_get_request(struct ceph_osd_request *req)
 {
 	kref_get(&req->r_kref);
@@ -233,5 +277,14 @@ extern int ceph_osdc_writepages(struct ceph_osd_client *osdc,
 				struct page **pages, int nr_pages,
 				int flags, int do_sync, bool nofail);
 
+/* watch/notify events */
+extern int ceph_osdc_create_event(struct ceph_osd_client *osdc,
+				  void (*event_cb)(u64, u64, u8, void *),
+				  int one_shot, void *data,
+				  struct ceph_osd_event **pevent);
+extern void ceph_osdc_cancel_event(struct ceph_osd_event *event);
+extern int ceph_osdc_wait_event(struct ceph_osd_event *event,
+				unsigned long timeout);
+extern void ceph_osdc_put_event(struct ceph_osd_event *event);
 #endif
 
diff --git a/include/linux/ceph/rados.h b/include/linux/ceph/rados.h
index 6d5247f2e81b273538e78df5db1dc9204674a2d3..0a99099801a4ec56ad04e0dcbe1e25e28eba2210 100644
--- a/include/linux/ceph/rados.h
+++ b/include/linux/ceph/rados.h
@@ -12,9 +12,9 @@
  * osdmap encoding versions
  */
 #define CEPH_OSDMAP_INC_VERSION     5
-#define CEPH_OSDMAP_INC_VERSION_EXT 5
+#define CEPH_OSDMAP_INC_VERSION_EXT 6
 #define CEPH_OSDMAP_VERSION         5
-#define CEPH_OSDMAP_VERSION_EXT     5
+#define CEPH_OSDMAP_VERSION_EXT     6
 
 /*
  * fs id
@@ -181,9 +181,17 @@ enum {
 	/* read */
 	CEPH_OSD_OP_READ      = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 1,
 	CEPH_OSD_OP_STAT      = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 2,
+	CEPH_OSD_OP_MAPEXT    = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 3,
 
 	/* fancy read */
-	CEPH_OSD_OP_MASKTRUNC = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 4,
+	CEPH_OSD_OP_MASKTRUNC   = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 4,
+	CEPH_OSD_OP_SPARSE_READ = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 5,
+
+	CEPH_OSD_OP_NOTIFY    = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 6,
+	CEPH_OSD_OP_NOTIFY_ACK = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 7,
+
+	/* versioning */
+	CEPH_OSD_OP_ASSERT_VER = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_DATA | 8,
 
 	/* write */
 	CEPH_OSD_OP_WRITE     = CEPH_OSD_OP_MODE_WR | CEPH_OSD_OP_TYPE_DATA | 1,
@@ -205,6 +213,8 @@ enum {
 	CEPH_OSD_OP_CREATE  = CEPH_OSD_OP_MODE_WR | CEPH_OSD_OP_TYPE_DATA | 13,
 	CEPH_OSD_OP_ROLLBACK= CEPH_OSD_OP_MODE_WR | CEPH_OSD_OP_TYPE_DATA | 14,
 
+	CEPH_OSD_OP_WATCH   = CEPH_OSD_OP_MODE_WR | CEPH_OSD_OP_TYPE_DATA | 15,
+
 	/** attrs **/
 	/* read */
 	CEPH_OSD_OP_GETXATTR  = CEPH_OSD_OP_MODE_RD | CEPH_OSD_OP_TYPE_ATTR | 1,
@@ -218,11 +228,14 @@ enum {
 	CEPH_OSD_OP_RMXATTR   = CEPH_OSD_OP_MODE_WR | CEPH_OSD_OP_TYPE_ATTR | 4,
 
 	/** subop **/
-	CEPH_OSD_OP_PULL           = CEPH_OSD_OP_MODE_SUB | 1,
-	CEPH_OSD_OP_PUSH           = CEPH_OSD_OP_MODE_SUB | 2,
-	CEPH_OSD_OP_BALANCEREADS   = CEPH_OSD_OP_MODE_SUB | 3,
-	CEPH_OSD_OP_UNBALANCEREADS = CEPH_OSD_OP_MODE_SUB | 4,
-	CEPH_OSD_OP_SCRUB          = CEPH_OSD_OP_MODE_SUB | 5,
+	CEPH_OSD_OP_PULL            = CEPH_OSD_OP_MODE_SUB | 1,
+	CEPH_OSD_OP_PUSH            = CEPH_OSD_OP_MODE_SUB | 2,
+	CEPH_OSD_OP_BALANCEREADS    = CEPH_OSD_OP_MODE_SUB | 3,
+	CEPH_OSD_OP_UNBALANCEREADS  = CEPH_OSD_OP_MODE_SUB | 4,
+	CEPH_OSD_OP_SCRUB           = CEPH_OSD_OP_MODE_SUB | 5,
+	CEPH_OSD_OP_SCRUB_RESERVE   = CEPH_OSD_OP_MODE_SUB | 6,
+	CEPH_OSD_OP_SCRUB_UNRESERVE = CEPH_OSD_OP_MODE_SUB | 7,
+	CEPH_OSD_OP_SCRUB_STOP      = CEPH_OSD_OP_MODE_SUB | 8,
 
 	/** lock **/
 	CEPH_OSD_OP_WRLOCK    = CEPH_OSD_OP_MODE_WR | CEPH_OSD_OP_TYPE_LOCK | 1,
@@ -328,6 +341,8 @@ enum {
 	CEPH_OSD_CMPXATTR_MODE_U64    = 2
 };
 
+#define RADOS_NOTIFY_VER	1
+
 /*
  * an individual object operation.  each may be accompanied by some data
  * payload
@@ -359,7 +374,12 @@ struct ceph_osd_op {
 	        struct {
 		        __le64 snapid;
 	        } __attribute__ ((packed)) snap;
-	};
+		struct {
+			__le64 cookie;
+			__le64 ver;
+			__u8 flag;	/* 0 = unwatch, 1 = watch */
+		} __attribute__ ((packed)) watch;
+};
 	__le32 payload_len;
 } __attribute__ ((packed));
 
@@ -402,4 +422,5 @@ struct ceph_osd_reply_head {
 } __attribute__ ((packed));
 
 
+
 #endif
diff --git a/net/ceph/armor.c b/net/ceph/armor.c
index eb2a666b0be7011e9b27618c62060416543cb706..1fc1ee11dfa28088f00becf58d7c22fd2420cb36 100644
--- a/net/ceph/armor.c
+++ b/net/ceph/armor.c
@@ -78,8 +78,10 @@ int ceph_unarmor(char *dst, const char *src, const char *end)
 	while (src < end) {
 		int a, b, c, d;
 
-		if (src < end && src[0] == '\n')
+		if (src[0] == '\n') {
 			src++;
+			continue;
+		}
 		if (src + 4 > end)
 			return -EINVAL;
 		a = decode_bits(src[0]);
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index f3e4a13fea0c8a5337ce5383951fb389ea24144a..95f96ab94bba12b57052705d385be749d6183c53 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -62,6 +62,7 @@ const char *ceph_msg_type_name(int type)
 	case CEPH_MSG_OSD_MAP: return "osd_map";
 	case CEPH_MSG_OSD_OP: return "osd_op";
 	case CEPH_MSG_OSD_OPREPLY: return "osd_opreply";
+	case CEPH_MSG_WATCH_NOTIFY: return "watch_notify";
 	default: return "unknown";
 	}
 }
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 3e20a122ffa2f2bf40a91596fe12bb93e6874b64..02212ed50852eaa41b5d0c75c7f121b77f074ce3 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -22,10 +22,15 @@
 #define OSD_OPREPLY_FRONT_LEN	512
 
 static const struct ceph_connection_operations osd_con_ops;
-static int __kick_requests(struct ceph_osd_client *osdc,
-			  struct ceph_osd *kickosd);
 
-static void kick_requests(struct ceph_osd_client *osdc, struct ceph_osd *osd);
+static void send_queued(struct ceph_osd_client *osdc);
+static int __reset_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd);
+static void __register_request(struct ceph_osd_client *osdc,
+			       struct ceph_osd_request *req);
+static void __unregister_linger_request(struct ceph_osd_client *osdc,
+					struct ceph_osd_request *req);
+static int __send_request(struct ceph_osd_client *osdc,
+			  struct ceph_osd_request *req);
 
 static int op_needs_trail(int op)
 {
@@ -34,6 +39,7 @@ static int op_needs_trail(int op)
 	case CEPH_OSD_OP_SETXATTR:
 	case CEPH_OSD_OP_CMPXATTR:
 	case CEPH_OSD_OP_CALL:
+	case CEPH_OSD_OP_NOTIFY:
 		return 1;
 	default:
 		return 0;
@@ -209,6 +215,8 @@ struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
 	init_completion(&req->r_completion);
 	init_completion(&req->r_safe_completion);
 	INIT_LIST_HEAD(&req->r_unsafe_item);
+	INIT_LIST_HEAD(&req->r_linger_item);
+	INIT_LIST_HEAD(&req->r_linger_osd);
 	req->r_flags = flags;
 
 	WARN_ON((flags & (CEPH_OSD_FLAG_READ|CEPH_OSD_FLAG_WRITE)) == 0);
@@ -315,6 +323,24 @@ static void osd_req_encode_op(struct ceph_osd_request *req,
 		break;
 	case CEPH_OSD_OP_STARTSYNC:
 		break;
+	case CEPH_OSD_OP_NOTIFY:
+		{
+			__le32 prot_ver = cpu_to_le32(src->watch.prot_ver);
+			__le32 timeout = cpu_to_le32(src->watch.timeout);
+
+			BUG_ON(!req->r_trail);
+
+			ceph_pagelist_append(req->r_trail,
+						&prot_ver, sizeof(prot_ver));
+			ceph_pagelist_append(req->r_trail,
+						&timeout, sizeof(timeout));
+		}
+	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;
+		break;
 	default:
 		pr_err("unrecognized osd opcode %d\n", dst->op);
 		WARN_ON(1);
@@ -529,6 +555,45 @@ __lookup_request_ge(struct ceph_osd_client *osdc,
 	return NULL;
 }
 
+/*
+ * Resubmit requests pending on the given osd.
+ */
+static void __kick_osd_requests(struct ceph_osd_client *osdc,
+				struct ceph_osd *osd)
+{
+	struct ceph_osd_request *req, *nreq;
+	int err;
+
+	dout("__kick_osd_requests osd%d\n", osd->o_osd);
+	err = __reset_osd(osdc, osd);
+	if (err == -EAGAIN)
+		return;
+
+	list_for_each_entry(req, &osd->o_requests, r_osd_item) {
+		list_move(&req->r_req_lru_item, &osdc->req_unsent);
+		dout("requeued %p tid %llu osd%d\n", req, req->r_tid,
+		     osd->o_osd);
+		if (!req->r_linger)
+			req->r_flags |= CEPH_OSD_FLAG_RETRY;
+	}
+
+	list_for_each_entry_safe(req, nreq, &osd->o_linger_requests,
+				 r_linger_osd) {
+		__unregister_linger_request(osdc, req);
+		__register_request(osdc, req);
+		list_move(&req->r_req_lru_item, &osdc->req_unsent);
+		dout("requeued lingering %p tid %llu osd%d\n", req, req->r_tid,
+		     osd->o_osd);
+	}
+}
+
+static void kick_osd_requests(struct ceph_osd_client *osdc,
+			      struct ceph_osd *kickosd)
+{
+	mutex_lock(&osdc->request_mutex);
+	__kick_osd_requests(osdc, kickosd);
+	mutex_unlock(&osdc->request_mutex);
+}
 
 /*
  * If the osd connection drops, we need to resubmit all requests.
@@ -543,7 +608,8 @@ static void osd_reset(struct ceph_connection *con)
 	dout("osd_reset osd%d\n", osd->o_osd);
 	osdc = osd->o_osdc;
 	down_read(&osdc->map_sem);
-	kick_requests(osdc, osd);
+	kick_osd_requests(osdc, osd);
+	send_queued(osdc);
 	up_read(&osdc->map_sem);
 }
 
@@ -561,6 +627,7 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc)
 	atomic_set(&osd->o_ref, 1);
 	osd->o_osdc = osdc;
 	INIT_LIST_HEAD(&osd->o_requests);
+	INIT_LIST_HEAD(&osd->o_linger_requests);
 	INIT_LIST_HEAD(&osd->o_osd_lru);
 	osd->o_incarnation = 1;
 
@@ -650,7 +717,8 @@ static int __reset_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
 	int ret = 0;
 
 	dout("__reset_osd %p osd%d\n", osd, osd->o_osd);
-	if (list_empty(&osd->o_requests)) {
+	if (list_empty(&osd->o_requests) &&
+	    list_empty(&osd->o_linger_requests)) {
 		__remove_osd(osdc, osd);
 	} else if (memcmp(&osdc->osdmap->osd_addr[osd->o_osd],
 			  &osd->o_con.peer_addr,
@@ -723,10 +791,9 @@ static void __cancel_osd_timeout(struct ceph_osd_client *osdc)
  * Register request, assign tid.  If this is the first request, set up
  * the timeout event.
  */
-static void register_request(struct ceph_osd_client *osdc,
-			     struct ceph_osd_request *req)
+static void __register_request(struct ceph_osd_client *osdc,
+			       struct ceph_osd_request *req)
 {
-	mutex_lock(&osdc->request_mutex);
 	req->r_tid = ++osdc->last_tid;
 	req->r_request->hdr.tid = cpu_to_le64(req->r_tid);
 	INIT_LIST_HEAD(&req->r_req_lru_item);
@@ -740,6 +807,13 @@ static void register_request(struct ceph_osd_client *osdc,
 		dout(" first request, scheduling timeout\n");
 		__schedule_osd_timeout(osdc);
 	}
+}
+
+static void register_request(struct ceph_osd_client *osdc,
+			     struct ceph_osd_request *req)
+{
+	mutex_lock(&osdc->request_mutex);
+	__register_request(osdc, req);
 	mutex_unlock(&osdc->request_mutex);
 }
 
@@ -758,9 +832,14 @@ static void __unregister_request(struct ceph_osd_client *osdc,
 		ceph_con_revoke(&req->r_osd->o_con, req->r_request);
 
 		list_del_init(&req->r_osd_item);
-		if (list_empty(&req->r_osd->o_requests))
+		if (list_empty(&req->r_osd->o_requests) &&
+		    list_empty(&req->r_osd->o_linger_requests)) {
+			dout("moving osd to %p lru\n", req->r_osd);
 			__move_osd_to_lru(osdc, req->r_osd);
-		req->r_osd = NULL;
+		}
+		if (list_empty(&req->r_osd_item) &&
+		    list_empty(&req->r_linger_item))
+			req->r_osd = NULL;
 	}
 
 	ceph_osdc_put_request(req);
@@ -781,20 +860,72 @@ static void __cancel_request(struct ceph_osd_request *req)
 		ceph_con_revoke(&req->r_osd->o_con, req->r_request);
 		req->r_sent = 0;
 	}
-	list_del_init(&req->r_req_lru_item);
 }
 
+static void __register_linger_request(struct ceph_osd_client *osdc,
+				    struct ceph_osd_request *req)
+{
+	dout("__register_linger_request %p\n", req);
+	list_add_tail(&req->r_linger_item, &osdc->req_linger);
+	list_add_tail(&req->r_linger_osd, &req->r_osd->o_linger_requests);
+}
+
+static void __unregister_linger_request(struct ceph_osd_client *osdc,
+					struct ceph_osd_request *req)
+{
+	dout("__unregister_linger_request %p\n", req);
+	if (req->r_osd) {
+		list_del_init(&req->r_linger_item);
+		list_del_init(&req->r_linger_osd);
+
+		if (list_empty(&req->r_osd->o_requests) &&
+		    list_empty(&req->r_osd->o_linger_requests)) {
+			dout("moving osd to %p lru\n", req->r_osd);
+			__move_osd_to_lru(osdc, req->r_osd);
+		}
+		req->r_osd = NULL;
+	}
+}
+
+void ceph_osdc_unregister_linger_request(struct ceph_osd_client *osdc,
+					 struct ceph_osd_request *req)
+{
+	mutex_lock(&osdc->request_mutex);
+	if (req->r_linger) {
+		__unregister_linger_request(osdc, req);
+		ceph_osdc_put_request(req);
+	}
+	mutex_unlock(&osdc->request_mutex);
+}
+EXPORT_SYMBOL(ceph_osdc_unregister_linger_request);
+
+void ceph_osdc_set_request_linger(struct ceph_osd_client *osdc,
+				  struct ceph_osd_request *req)
+{
+	if (!req->r_linger) {
+		dout("set_request_linger %p\n", req);
+		req->r_linger = 1;
+		/*
+		 * caller is now responsible for calling
+		 * unregister_linger_request
+		 */
+		ceph_osdc_get_request(req);
+	}
+}
+EXPORT_SYMBOL(ceph_osdc_set_request_linger);
+
 /*
  * Pick an osd (the first 'up' osd in the pg), allocate the osd struct
  * (as needed), and set the request r_osd appropriately.  If there is
- * no up osd, set r_osd to NULL.
+ * no up osd, set r_osd to NULL.  Move the request to the appropiate list
+ * (unsent, homeless) or leave on in-flight lru.
  *
  * Return 0 if unchanged, 1 if changed, or negative on error.
  *
  * Caller should hold map_sem for read and request_mutex.
  */
-static int __map_osds(struct ceph_osd_client *osdc,
-		      struct ceph_osd_request *req)
+static int __map_request(struct ceph_osd_client *osdc,
+			 struct ceph_osd_request *req)
 {
 	struct ceph_osd_request_head *reqhead = req->r_request->front.iov_base;
 	struct ceph_pg pgid;
@@ -802,11 +933,13 @@ static int __map_osds(struct ceph_osd_client *osdc,
 	int o = -1, num = 0;
 	int err;
 
-	dout("map_osds %p tid %lld\n", req, req->r_tid);
+	dout("map_request %p tid %lld\n", req, req->r_tid);
 	err = ceph_calc_object_layout(&reqhead->layout, req->r_oid,
 				      &req->r_file_layout, osdc->osdmap);
-	if (err)
+	if (err) {
+		list_move(&req->r_req_lru_item, &osdc->req_notarget);
 		return err;
+	}
 	pgid = reqhead->layout.ol_pgid;
 	req->r_pgid = pgid;
 
@@ -823,7 +956,7 @@ static int __map_osds(struct ceph_osd_client *osdc,
 	    (req->r_osd == NULL && o == -1))
 		return 0;  /* no change */
 
-	dout("map_osds tid %llu pgid %d.%x osd%d (was osd%d)\n",
+	dout("map_request tid %llu pgid %d.%x osd%d (was osd%d)\n",
 	     req->r_tid, le32_to_cpu(pgid.pool), le16_to_cpu(pgid.ps), o,
 	     req->r_osd ? req->r_osd->o_osd : -1);
 
@@ -841,10 +974,12 @@ static int __map_osds(struct ceph_osd_client *osdc,
 	if (!req->r_osd && o >= 0) {
 		err = -ENOMEM;
 		req->r_osd = create_osd(osdc);
-		if (!req->r_osd)
+		if (!req->r_osd) {
+			list_move(&req->r_req_lru_item, &osdc->req_notarget);
 			goto out;
+		}
 
-		dout("map_osds osd %p is osd%d\n", req->r_osd, o);
+		dout("map_request osd %p is osd%d\n", req->r_osd, o);
 		req->r_osd->o_osd = o;
 		req->r_osd->o_con.peer_name.num = cpu_to_le64(o);
 		__insert_osd(osdc, req->r_osd);
@@ -855,6 +990,9 @@ static int __map_osds(struct ceph_osd_client *osdc,
 	if (req->r_osd) {
 		__remove_osd_from_lru(req->r_osd);
 		list_add(&req->r_osd_item, &req->r_osd->o_requests);
+		list_move(&req->r_req_lru_item, &osdc->req_unsent);
+	} else {
+		list_move(&req->r_req_lru_item, &osdc->req_notarget);
 	}
 	err = 1;   /* osd or pg changed */
 
@@ -869,16 +1007,6 @@ static int __send_request(struct ceph_osd_client *osdc,
 			  struct ceph_osd_request *req)
 {
 	struct ceph_osd_request_head *reqhead;
-	int err;
-
-	err = __map_osds(osdc, req);
-	if (err < 0)
-		return err;
-	if (req->r_osd == NULL) {
-		dout("send_request %p no up osds in pg\n", req);
-		ceph_monc_request_next_osdmap(&osdc->client->monc);
-		return 0;
-	}
 
 	dout("send_request %p tid %llu to osd%d flags %d\n",
 	     req, req->r_tid, req->r_osd->o_osd, req->r_flags);
@@ -897,6 +1025,21 @@ static int __send_request(struct ceph_osd_client *osdc,
 	return 0;
 }
 
+/*
+ * Send any requests in the queue (req_unsent).
+ */
+static void send_queued(struct ceph_osd_client *osdc)
+{
+	struct ceph_osd_request *req, *tmp;
+
+	dout("send_queued\n");
+	mutex_lock(&osdc->request_mutex);
+	list_for_each_entry_safe(req, tmp, &osdc->req_unsent, r_req_lru_item) {
+		__send_request(osdc, req);
+	}
+	mutex_unlock(&osdc->request_mutex);
+}
+
 /*
  * Timeout callback, called every N seconds when 1 or more osd
  * requests has been active for more than N seconds.  When this
@@ -916,30 +1059,13 @@ static void handle_timeout(struct work_struct *work)
 	unsigned long keepalive =
 		osdc->client->options->osd_keepalive_timeout * HZ;
 	unsigned long last_stamp = 0;
-	struct rb_node *p;
 	struct list_head slow_osds;
-
 	dout("timeout\n");
 	down_read(&osdc->map_sem);
 
 	ceph_monc_request_next_osdmap(&osdc->client->monc);
 
 	mutex_lock(&osdc->request_mutex);
-	for (p = rb_first(&osdc->requests); p; p = rb_next(p)) {
-		req = rb_entry(p, struct ceph_osd_request, r_node);
-
-		if (req->r_resend) {
-			int err;
-
-			dout("osdc resending prev failed %lld\n", req->r_tid);
-			err = __send_request(osdc, req);
-			if (err)
-				dout("osdc failed again on %lld\n", req->r_tid);
-			else
-				req->r_resend = false;
-			continue;
-		}
-	}
 
 	/*
 	 * reset osds that appear to be _really_ unresponsive.  this
@@ -963,7 +1089,7 @@ static void handle_timeout(struct work_struct *work)
 		BUG_ON(!osd);
 		pr_warning(" tid %llu timed out on osd%d, will reset osd\n",
 			   req->r_tid, osd->o_osd);
-		__kick_requests(osdc, osd);
+		__kick_osd_requests(osdc, osd);
 	}
 
 	/*
@@ -991,7 +1117,7 @@ static void handle_timeout(struct work_struct *work)
 
 	__schedule_osd_timeout(osdc);
 	mutex_unlock(&osdc->request_mutex);
-
+	send_queued(osdc);
 	up_read(&osdc->map_sem);
 }
 
@@ -1035,7 +1161,6 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 	    numops * sizeof(struct ceph_osd_op))
 		goto bad;
 	dout("handle_reply %p tid %llu result %d\n", msg, tid, (int)result);
-
 	/* lookup */
 	mutex_lock(&osdc->request_mutex);
 	req = __lookup_request(osdc, tid);
@@ -1079,6 +1204,9 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 
 	dout("handle_reply tid %llu flags %d\n", tid, flags);
 
+	if (req->r_linger && (flags & CEPH_OSD_FLAG_ONDISK))
+		__register_linger_request(osdc, req);
+
 	/* either this is a read, or we got the safe response */
 	if (result < 0 ||
 	    (flags & CEPH_OSD_FLAG_ONDISK) ||
@@ -1099,6 +1227,7 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 	}
 
 done:
+	dout("req=%p req->r_linger=%d\n", req, req->r_linger);
 	ceph_osdc_put_request(req);
 	return;
 
@@ -1109,108 +1238,83 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 	ceph_msg_dump(msg);
 }
 
-
-static int __kick_requests(struct ceph_osd_client *osdc,
-			  struct ceph_osd *kickosd)
+static void reset_changed_osds(struct ceph_osd_client *osdc)
 {
-	struct ceph_osd_request *req;
 	struct rb_node *p, *n;
-	int needmap = 0;
-	int err;
 
-	dout("kick_requests osd%d\n", kickosd ? kickosd->o_osd : -1);
-	if (kickosd) {
-		err = __reset_osd(osdc, kickosd);
-		if (err == -EAGAIN)
-			return 1;
-	} else {
-		for (p = rb_first(&osdc->osds); p; p = n) {
-			struct ceph_osd *osd =
-				rb_entry(p, struct ceph_osd, o_node);
-
-			n = rb_next(p);
-			if (!ceph_osd_is_up(osdc->osdmap, osd->o_osd) ||
-			    memcmp(&osd->o_con.peer_addr,
-				   ceph_osd_addr(osdc->osdmap,
-						 osd->o_osd),
-				   sizeof(struct ceph_entity_addr)) != 0)
-				__reset_osd(osdc, osd);
-		}
+	for (p = rb_first(&osdc->osds); p; p = n) {
+		struct ceph_osd *osd = rb_entry(p, struct ceph_osd, o_node);
+
+		n = rb_next(p);
+		if (!ceph_osd_is_up(osdc->osdmap, osd->o_osd) ||
+		    memcmp(&osd->o_con.peer_addr,
+			   ceph_osd_addr(osdc->osdmap,
+					 osd->o_osd),
+			   sizeof(struct ceph_entity_addr)) != 0)
+			__reset_osd(osdc, osd);
 	}
+}
+
+/*
+ * Requeue requests whose mapping to an OSD has changed.  If requests map to
+ * no osd, request a new map.
+ *
+ * Caller should hold map_sem for read and request_mutex.
+ */
+static void kick_requests(struct ceph_osd_client *osdc)
+{
+	struct ceph_osd_request *req, *nreq;
+	struct rb_node *p;
+	int needmap = 0;
+	int err;
 
+	dout("kick_requests\n");
+	mutex_lock(&osdc->request_mutex);
 	for (p = rb_first(&osdc->requests); p; p = rb_next(p)) {
 		req = rb_entry(p, struct ceph_osd_request, r_node);
-
-		if (req->r_resend) {
-			dout(" r_resend set on tid %llu\n", req->r_tid);
-			__cancel_request(req);
-			goto kick;
-		}
-		if (req->r_osd && kickosd == req->r_osd) {
-			__cancel_request(req);
-			goto kick;
+		err = __map_request(osdc, req);
+		if (err < 0)
+			continue;  /* error */
+		if (req->r_osd == NULL) {
+			dout("%p tid %llu maps to no osd\n", req, req->r_tid);
+			needmap++;  /* request a newer map */
+		} else if (err > 0) {
+			dout("%p tid %llu requeued on osd%d\n", req, req->r_tid,
+			     req->r_osd ? req->r_osd->o_osd : -1);
+			if (!req->r_linger)
+				req->r_flags |= CEPH_OSD_FLAG_RETRY;
 		}
+	}
+
+	list_for_each_entry_safe(req, nreq, &osdc->req_linger,
+				 r_linger_item) {
+		dout("linger req=%p req->r_osd=%p\n", req, req->r_osd);
 
-		err = __map_osds(osdc, req);
+		err = __map_request(osdc, req);
 		if (err == 0)
-			continue;  /* no change */
-		if (err < 0) {
-			/*
-			 * FIXME: really, we should set the request
-			 * error and fail if this isn't a 'nofail'
-			 * request, but that's a fair bit more
-			 * complicated to do.  So retry!
-			 */
-			dout(" setting r_resend on %llu\n", req->r_tid);
-			req->r_resend = true;
-			continue;
-		}
+			continue;  /* no change and no osd was specified */
+		if (err < 0)
+			continue;  /* hrm! */
 		if (req->r_osd == NULL) {
 			dout("tid %llu maps to no valid osd\n", req->r_tid);
 			needmap++;  /* request a newer map */
 			continue;
 		}
 
-kick:
-		dout("kicking %p tid %llu osd%d\n", req, req->r_tid,
+		dout("kicking lingering %p tid %llu osd%d\n", req, req->r_tid,
 		     req->r_osd ? req->r_osd->o_osd : -1);
-		req->r_flags |= CEPH_OSD_FLAG_RETRY;
-		err = __send_request(osdc, req);
-		if (err) {
-			dout(" setting r_resend on %llu\n", req->r_tid);
-			req->r_resend = true;
-		}
+		__unregister_linger_request(osdc, req);
+		__register_request(osdc, req);
 	}
-
-	return needmap;
-}
-
-/*
- * Resubmit osd requests whose osd or osd address has changed.  Request
- * a new osd map if osds are down, or we are otherwise unable to determine
- * how to direct a request.
- *
- * Close connections to down osds.
- *
- * If @who is specified, resubmit requests for that specific osd.
- *
- * Caller should hold map_sem for read and request_mutex.
- */
-static void kick_requests(struct ceph_osd_client *osdc,
-			  struct ceph_osd *kickosd)
-{
-	int needmap;
-
-	mutex_lock(&osdc->request_mutex);
-	needmap = __kick_requests(osdc, kickosd);
 	mutex_unlock(&osdc->request_mutex);
 
 	if (needmap) {
 		dout("%d requests for down osds, need new map\n", needmap);
 		ceph_monc_request_next_osdmap(&osdc->client->monc);
 	}
-
 }
+
+
 /*
  * Process updated osd map.
  *
@@ -1263,6 +1367,8 @@ void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 				ceph_osdmap_destroy(osdc->osdmap);
 				osdc->osdmap = newmap;
 			}
+			kick_requests(osdc);
+			reset_changed_osds(osdc);
 		} else {
 			dout("ignoring incremental map %u len %d\n",
 			     epoch, maplen);
@@ -1300,6 +1406,7 @@ void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 			osdc->osdmap = newmap;
 			if (oldmap)
 				ceph_osdmap_destroy(oldmap);
+			kick_requests(osdc);
 		}
 		p += maplen;
 		nr_maps--;
@@ -1308,8 +1415,7 @@ void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 done:
 	downgrade_write(&osdc->map_sem);
 	ceph_monc_got_osdmap(&osdc->client->monc, osdc->osdmap->epoch);
-	if (newmap)
-		kick_requests(osdc, NULL);
+	send_queued(osdc);
 	up_read(&osdc->map_sem);
 	wake_up_all(&osdc->client->auth_wq);
 	return;
@@ -1321,6 +1427,223 @@ void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 	return;
 }
 
+/*
+ * watch/notify callback event infrastructure
+ *
+ * These callbacks are used both for watch and notify operations.
+ */
+static void __release_event(struct kref *kref)
+{
+	struct ceph_osd_event *event =
+		container_of(kref, struct ceph_osd_event, kref);
+
+	dout("__release_event %p\n", event);
+	kfree(event);
+}
+
+static void get_event(struct ceph_osd_event *event)
+{
+	kref_get(&event->kref);
+}
+
+void ceph_osdc_put_event(struct ceph_osd_event *event)
+{
+	kref_put(&event->kref, __release_event);
+}
+EXPORT_SYMBOL(ceph_osdc_put_event);
+
+static void __insert_event(struct ceph_osd_client *osdc,
+			     struct ceph_osd_event *new)
+{
+	struct rb_node **p = &osdc->event_tree.rb_node;
+	struct rb_node *parent = NULL;
+	struct ceph_osd_event *event = NULL;
+
+	while (*p) {
+		parent = *p;
+		event = rb_entry(parent, struct ceph_osd_event, node);
+		if (new->cookie < event->cookie)
+			p = &(*p)->rb_left;
+		else if (new->cookie > event->cookie)
+			p = &(*p)->rb_right;
+		else
+			BUG();
+	}
+
+	rb_link_node(&new->node, parent, p);
+	rb_insert_color(&new->node, &osdc->event_tree);
+}
+
+static struct ceph_osd_event *__find_event(struct ceph_osd_client *osdc,
+					        u64 cookie)
+{
+	struct rb_node **p = &osdc->event_tree.rb_node;
+	struct rb_node *parent = NULL;
+	struct ceph_osd_event *event = NULL;
+
+	while (*p) {
+		parent = *p;
+		event = rb_entry(parent, struct ceph_osd_event, node);
+		if (cookie < event->cookie)
+			p = &(*p)->rb_left;
+		else if (cookie > event->cookie)
+			p = &(*p)->rb_right;
+		else
+			return event;
+	}
+	return NULL;
+}
+
+static void __remove_event(struct ceph_osd_event *event)
+{
+	struct ceph_osd_client *osdc = event->osdc;
+
+	if (!RB_EMPTY_NODE(&event->node)) {
+		dout("__remove_event removed %p\n", event);
+		rb_erase(&event->node, &osdc->event_tree);
+		ceph_osdc_put_event(event);
+	} else {
+		dout("__remove_event didn't remove %p\n", event);
+	}
+}
+
+int ceph_osdc_create_event(struct ceph_osd_client *osdc,
+			   void (*event_cb)(u64, u64, u8, void *),
+			   int one_shot, void *data,
+			   struct ceph_osd_event **pevent)
+{
+	struct ceph_osd_event *event;
+
+	event = kmalloc(sizeof(*event), GFP_NOIO);
+	if (!event)
+		return -ENOMEM;
+
+	dout("create_event %p\n", event);
+	event->cb = event_cb;
+	event->one_shot = one_shot;
+	event->data = data;
+	event->osdc = osdc;
+	INIT_LIST_HEAD(&event->osd_node);
+	kref_init(&event->kref);   /* one ref for us */
+	kref_get(&event->kref);    /* one ref for the caller */
+	init_completion(&event->completion);
+
+	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_event);
+
+void ceph_osdc_cancel_event(struct ceph_osd_event *event)
+{
+	struct ceph_osd_client *osdc = event->osdc;
+
+	dout("cancel_event %p\n", event);
+	spin_lock(&osdc->event_lock);
+	__remove_event(event);
+	spin_unlock(&osdc->event_lock);
+	ceph_osdc_put_event(event); /* caller's */
+}
+EXPORT_SYMBOL(ceph_osdc_cancel_event);
+
+
+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;
+
+	dout("do_event_work completing %p\n", event);
+	event->cb(ver, notify_id, opcode, event->data);
+	complete(&event->completion);
+	dout("do_event_work completed %p\n", event);
+	ceph_osdc_put_event(event);
+	kfree(event_work);
+}
+
+
+/*
+ * Process osd watch notifications
+ */
+void handle_watch_notify(struct ceph_osd_client *osdc, struct ceph_msg *msg)
+{
+	void *p, *end;
+	u8 proto_ver;
+	u64 cookie, ver, notify_id;
+	u8 opcode;
+	struct ceph_osd_event *event;
+	struct ceph_osd_event_work *event_work;
+
+	p = msg->front.iov_base;
+	end = p + msg->front.iov_len;
+
+	ceph_decode_8_safe(&p, end, proto_ver, bad);
+	ceph_decode_8_safe(&p, end, opcode, bad);
+	ceph_decode_64_safe(&p, end, cookie, bad);
+	ceph_decode_64_safe(&p, end, ver, bad);
+	ceph_decode_64_safe(&p, end, notify_id, bad);
+
+	spin_lock(&osdc->event_lock);
+	event = __find_event(osdc, cookie);
+	if (event) {
+		get_event(event);
+		if (event->one_shot)
+			__remove_event(event);
+	}
+	spin_unlock(&osdc->event_lock);
+	dout("handle_watch_notify cookie %lld ver %lld event %p\n",
+	     cookie, ver, event);
+	if (event) {
+		event_work = kmalloc(sizeof(*event_work), GFP_NOIO);
+		INIT_WORK(&event_work->work, do_event_work);
+		if (!event_work) {
+			dout("ERROR: could not allocate event_work\n");
+			goto done_err;
+		}
+		event_work->event = event;
+		event_work->ver = ver;
+		event_work->notify_id = notify_id;
+		event_work->opcode = opcode;
+		if (!queue_work(osdc->notify_wq, &event_work->work)) {
+			dout("WARNING: failed to queue notify event work\n");
+			goto done_err;
+		}
+	}
+
+	return;
+
+done_err:
+	complete(&event->completion);
+	ceph_osdc_put_event(event);
+	return;
+
+bad:
+	pr_err("osdc handle_watch_notify corrupt msg\n");
+	return;
+}
+
+int ceph_osdc_wait_event(struct ceph_osd_event *event, unsigned long timeout)
+{
+	int err;
+
+	dout("wait_event %p\n", event);
+	err = wait_for_completion_interruptible_timeout(&event->completion,
+							timeout * HZ);
+	ceph_osdc_put_event(event);
+	if (err > 0)
+		err = 0;
+	dout("wait_event %p returns %d\n", event, err);
+	return err;
+}
+EXPORT_SYMBOL(ceph_osdc_wait_event);
+
 /*
  * Register request, send initial attempt.
  */
@@ -1347,15 +1670,22 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc,
 	 * the request still han't been touched yet.
 	 */
 	if (req->r_sent == 0) {
-		rc = __send_request(osdc, req);
-		if (rc) {
-			if (nofail) {
-				dout("osdc_start_request failed send, "
-				     " marking %lld\n", req->r_tid);
-				req->r_resend = true;
-				rc = 0;
-			} else {
-				__unregister_request(osdc, req);
+		rc = __map_request(osdc, req);
+		if (rc < 0)
+			return rc;
+		if (req->r_osd == NULL) {
+			dout("send_request %p no up osds in pg\n", req);
+			ceph_monc_request_next_osdmap(&osdc->client->monc);
+		} else {
+			rc = __send_request(osdc, req);
+			if (rc) {
+				if (nofail) {
+					dout("osdc_start_request failed send, "
+					     " will retry %lld\n", req->r_tid);
+					rc = 0;
+				} else {
+					__unregister_request(osdc, req);
+				}
 			}
 		}
 	}
@@ -1441,9 +1771,15 @@ int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
 	INIT_LIST_HEAD(&osdc->osd_lru);
 	osdc->requests = RB_ROOT;
 	INIT_LIST_HEAD(&osdc->req_lru);
+	INIT_LIST_HEAD(&osdc->req_unsent);
+	INIT_LIST_HEAD(&osdc->req_notarget);
+	INIT_LIST_HEAD(&osdc->req_linger);
 	osdc->num_requests = 0;
 	INIT_DELAYED_WORK(&osdc->timeout_work, handle_timeout);
 	INIT_DELAYED_WORK(&osdc->osds_timeout_work, handle_osds_timeout);
+	spin_lock_init(&osdc->event_lock);
+	osdc->event_tree = RB_ROOT;
+	osdc->event_count = 0;
 
 	schedule_delayed_work(&osdc->osds_timeout_work,
 	   round_jiffies_relative(osdc->client->options->osd_idle_ttl * HZ));
@@ -1463,6 +1799,13 @@ int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
 				"osd_op_reply");
 	if (err < 0)
 		goto out_msgpool;
+
+	osdc->notify_wq = create_singlethread_workqueue("ceph-watch-notify");
+	if (IS_ERR(osdc->notify_wq)) {
+		err = PTR_ERR(osdc->notify_wq);
+		osdc->notify_wq = NULL;
+		goto out_msgpool;
+	}
 	return 0;
 
 out_msgpool:
@@ -1476,6 +1819,8 @@ EXPORT_SYMBOL(ceph_osdc_init);
 
 void ceph_osdc_stop(struct ceph_osd_client *osdc)
 {
+	flush_workqueue(osdc->notify_wq);
+	destroy_workqueue(osdc->notify_wq);
 	cancel_delayed_work_sync(&osdc->timeout_work);
 	cancel_delayed_work_sync(&osdc->osds_timeout_work);
 	if (osdc->osdmap) {
@@ -1483,6 +1828,7 @@ void ceph_osdc_stop(struct ceph_osd_client *osdc)
 		osdc->osdmap = NULL;
 	}
 	remove_old_osds(osdc, 1);
+	WARN_ON(!RB_EMPTY_ROOT(&osdc->osds));
 	mempool_destroy(osdc->req_mempool);
 	ceph_msgpool_destroy(&osdc->msgpool_op);
 	ceph_msgpool_destroy(&osdc->msgpool_op_reply);
@@ -1591,6 +1937,9 @@ static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
 	case CEPH_MSG_OSD_OPREPLY:
 		handle_reply(osdc, msg, con);
 		break;
+	case CEPH_MSG_WATCH_NOTIFY:
+		handle_watch_notify(osdc, msg);
+		break;
 
 	default:
 		pr_err("received unknown message type %d %s\n", type,
@@ -1684,6 +2033,7 @@ static struct ceph_msg *alloc_msg(struct ceph_connection *con,
 
 	switch (type) {
 	case CEPH_MSG_OSD_MAP:
+	case CEPH_MSG_WATCH_NOTIFY:
 		return ceph_msg_new(type, front, GFP_NOFS);
 	case CEPH_MSG_OSD_OPREPLY:
 		return get_reply(con, hdr, skip);