Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 3008 insertions, 0 deletions

diff --git a/kernel/net/ceph/osd_client.c b/kernel/net/ceph/osd_client.c
new file mode 100644
index 000000000..c4ec92392
--- /dev/null
+++ b/kernel/net/ceph/osd_client.c
@@ -0,0 +1,3008 @@
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#ifdef CONFIG_BLOCK
+#include <linux/bio.h>
+#endif
+
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/osd_client.h>
+#include <linux/ceph/messenger.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/auth.h>
+#include <linux/ceph/pagelist.h>
+
+#define OSD_OP_FRONT_LEN	4096
+#define OSD_OPREPLY_FRONT_LEN	512
+
+static struct kmem_cache	*ceph_osd_request_cache;
+
+static const struct ceph_connection_operations osd_con_ops;
+
+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_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 void __enqueue_request(struct ceph_osd_request *req);
+static void __send_request(struct ceph_osd_client *osdc,
+			   struct ceph_osd_request *req);
+
+/*
+ * Implement client access to distributed object storage cluster.
+ *
+ * All data objects are stored within a cluster/cloud of OSDs, or
+ * "object storage devices."  (Note that Ceph OSDs have _nothing_ to
+ * do with the T10 OSD extensions to SCSI.)  Ceph OSDs are simply
+ * remote daemons serving up and coordinating consistent and safe
+ * access to storage.
+ *
+ * Cluster membership and the mapping of data objects onto storage devices
+ * are described by the osd map.
+ *
+ * We keep track of pending OSD requests (read, write), resubmit
+ * requests to different OSDs when the cluster topology/data layout
+ * change, or retry the affected requests when the communications
+ * channel with an OSD is reset.
+ */
+
+/*
+ * calculate the mapping of a file extent onto an object, and fill out the
+ * request accordingly.  shorten extent as necessary if it crosses an
+ * object boundary.
+ *
+ * fill osd op in request message.
+ */
+static int calc_layout(struct ceph_file_layout *layout, u64 off, u64 *plen,
+			u64 *objnum, u64 *objoff, u64 *objlen)
+{
+	u64 orig_len = *plen;
+	int r;
+
+	/* object extent? */
+	r = ceph_calc_file_object_mapping(layout, off, orig_len, objnum,
+					  objoff, objlen);
+	if (r < 0)
+		return r;
+	if (*objlen < orig_len) {
+		*plen = *objlen;
+		dout(" skipping last %llu, final file extent %llu~%llu\n",
+		     orig_len - *plen, off, *plen);
+	}
+
+	dout("calc_layout objnum=%llx %llu~%llu\n", *objnum, *objoff, *objlen);
+
+	return 0;
+}
+
+static void ceph_osd_data_init(struct ceph_osd_data *osd_data)
+{
+	memset(osd_data, 0, sizeof (*osd_data));
+	osd_data->type = CEPH_OSD_DATA_TYPE_NONE;
+}
+
+static void ceph_osd_data_pages_init(struct ceph_osd_data *osd_data,
+			struct page **pages, u64 length, u32 alignment,
+			bool pages_from_pool, bool own_pages)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_PAGES;
+	osd_data->pages = pages;
+	osd_data->length = length;
+	osd_data->alignment = alignment;
+	osd_data->pages_from_pool = pages_from_pool;
+	osd_data->own_pages = own_pages;
+}
+
+static void ceph_osd_data_pagelist_init(struct ceph_osd_data *osd_data,
+			struct ceph_pagelist *pagelist)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_PAGELIST;
+	osd_data->pagelist = pagelist;
+}
+
+#ifdef CONFIG_BLOCK
+static void ceph_osd_data_bio_init(struct ceph_osd_data *osd_data,
+			struct bio *bio, size_t bio_length)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_BIO;
+	osd_data->bio = bio;
+	osd_data->bio_length = bio_length;
+}
+#endif /* CONFIG_BLOCK */
+
+#define osd_req_op_data(oreq, whch, typ, fld)	\
+	({						\
+		BUG_ON(whch >= (oreq)->r_num_ops);	\
+		&(oreq)->r_ops[whch].typ.fld;		\
+	})
+
+static struct ceph_osd_data *
+osd_req_op_raw_data_in(struct ceph_osd_request *osd_req, unsigned int which)
+{
+	BUG_ON(which >= osd_req->r_num_ops);
+
+	return &osd_req->r_ops[which].raw_data_in;
+}
+
+struct ceph_osd_data *
+osd_req_op_extent_osd_data(struct ceph_osd_request *osd_req,
+			unsigned int which)
+{
+	return osd_req_op_data(osd_req, which, extent, osd_data);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data);
+
+struct ceph_osd_data *
+osd_req_op_cls_response_data(struct ceph_osd_request *osd_req,
+			unsigned int which)
+{
+	return osd_req_op_data(osd_req, which, cls, response_data);
+}
+EXPORT_SYMBOL(osd_req_op_cls_response_data);	/* ??? */
+
+void osd_req_op_raw_data_in_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_raw_data_in(osd_req, which);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_raw_data_in_pages);
+
+void osd_req_op_extent_osd_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, extent, osd_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_pages);
+
+void osd_req_op_extent_osd_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, extent, osd_data);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_pagelist);
+
+#ifdef CONFIG_BLOCK
+void osd_req_op_extent_osd_data_bio(struct ceph_osd_request *osd_req,
+			unsigned int which, struct bio *bio, size_t bio_length)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
+	ceph_osd_data_bio_init(osd_data, bio, bio_length);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_bio);
+#endif /* CONFIG_BLOCK */
+
+static void osd_req_op_cls_request_info_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, cls, request_info);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+}
+
+void osd_req_op_cls_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, cls, request_data);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+}
+EXPORT_SYMBOL(osd_req_op_cls_request_data_pagelist);
+
+void osd_req_op_cls_request_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, cls, request_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_cls_request_data_pages);
+
+void osd_req_op_cls_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, cls, response_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_cls_response_data_pages);
+
+static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
+{
+	switch (osd_data->type) {
+	case CEPH_OSD_DATA_TYPE_NONE:
+		return 0;
+	case CEPH_OSD_DATA_TYPE_PAGES:
+		return osd_data->length;
+	case CEPH_OSD_DATA_TYPE_PAGELIST:
+		return (u64)osd_data->pagelist->length;
+#ifdef CONFIG_BLOCK
+	case CEPH_OSD_DATA_TYPE_BIO:
+		return (u64)osd_data->bio_length;
+#endif /* CONFIG_BLOCK */
+	default:
+		WARN(true, "unrecognized data type %d\n", (int)osd_data->type);
+		return 0;
+	}
+}
+
+static void ceph_osd_data_release(struct ceph_osd_data *osd_data)
+{
+	if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES && osd_data->own_pages) {
+		int num_pages;
+
+		num_pages = calc_pages_for((u64)osd_data->alignment,
+						(u64)osd_data->length);
+		ceph_release_page_vector(osd_data->pages, num_pages);
+	}
+	ceph_osd_data_init(osd_data);
+}
+
+static void osd_req_op_data_release(struct ceph_osd_request *osd_req,
+			unsigned int which)
+{
+	struct ceph_osd_req_op *op;
+
+	BUG_ON(which >= osd_req->r_num_ops);
+	op = &osd_req->r_ops[which];
+
+	switch (op->op) {
+	case CEPH_OSD_OP_READ:
+	case CEPH_OSD_OP_WRITE:
+		ceph_osd_data_release(&op->extent.osd_data);
+		break;
+	case CEPH_OSD_OP_CALL:
+		ceph_osd_data_release(&op->cls.request_info);
+		ceph_osd_data_release(&op->cls.request_data);
+		ceph_osd_data_release(&op->cls.response_data);
+		break;
+	case CEPH_OSD_OP_SETXATTR:
+	case CEPH_OSD_OP_CMPXATTR:
+		ceph_osd_data_release(&op->xattr.osd_data);
+		break;
+	default:
+		break;
+	}
+}
+
+/*
+ * requests
+ */
+static void ceph_osdc_release_request(struct kref *kref)
+{
+	struct ceph_osd_request *req = container_of(kref,
+					    struct ceph_osd_request, r_kref);
+	unsigned int which;
+
+	dout("%s %p (r_request %p r_reply %p)\n", __func__, req,
+	     req->r_request, req->r_reply);
+	WARN_ON(!RB_EMPTY_NODE(&req->r_node));
+	WARN_ON(!list_empty(&req->r_req_lru_item));
+	WARN_ON(!list_empty(&req->r_osd_item));
+	WARN_ON(!list_empty(&req->r_linger_item));
+	WARN_ON(!list_empty(&req->r_linger_osd_item));
+	WARN_ON(req->r_osd);
+
+	if (req->r_request)
+		ceph_msg_put(req->r_request);
+	if (req->r_reply) {
+		ceph_msg_revoke_incoming(req->r_reply);
+		ceph_msg_put(req->r_reply);
+	}
+
+	for (which = 0; which < req->r_num_ops; which++)
+		osd_req_op_data_release(req, which);
+
+	ceph_put_snap_context(req->r_snapc);
+	if (req->r_mempool)
+		mempool_free(req, req->r_osdc->req_mempool);
+	else
+		kmem_cache_free(ceph_osd_request_cache, req);
+
+}
+
+void ceph_osdc_get_request(struct ceph_osd_request *req)
+{
+	dout("%s %p (was %d)\n", __func__, req,
+	     atomic_read(&req->r_kref.refcount));
+	kref_get(&req->r_kref);
+}
+EXPORT_SYMBOL(ceph_osdc_get_request);
+
+void ceph_osdc_put_request(struct ceph_osd_request *req)
+{
+	dout("%s %p (was %d)\n", __func__, req,
+	     atomic_read(&req->r_kref.refcount));
+	kref_put(&req->r_kref, ceph_osdc_release_request);
+}
+EXPORT_SYMBOL(ceph_osdc_put_request);
+
+struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
+					       struct ceph_snap_context *snapc,
+					       unsigned int num_ops,
+					       bool use_mempool,
+					       gfp_t gfp_flags)
+{
+	struct ceph_osd_request *req;
+	struct ceph_msg *msg;
+	size_t msg_size;
+
+	BUILD_BUG_ON(CEPH_OSD_MAX_OP > U16_MAX);
+	BUG_ON(num_ops > CEPH_OSD_MAX_OP);
+
+	msg_size = 4 + 4 + 8 + 8 + 4+8;
+	msg_size += 2 + 4 + 8 + 4 + 4; /* oloc */
+	msg_size += 1 + 8 + 4 + 4;     /* pg_t */
+	msg_size += 4 + CEPH_MAX_OID_NAME_LEN; /* oid */
+	msg_size += 2 + num_ops*sizeof(struct ceph_osd_op);
+	msg_size += 8;  /* snapid */
+	msg_size += 8;  /* snap_seq */
+	msg_size += 8 * (snapc ? snapc->num_snaps : 0);  /* snaps */
+	msg_size += 4;
+
+	if (use_mempool) {
+		req = mempool_alloc(osdc->req_mempool, gfp_flags);
+		memset(req, 0, sizeof(*req));
+	} else {
+		req = kmem_cache_zalloc(ceph_osd_request_cache, gfp_flags);
+	}
+	if (req == NULL)
+		return NULL;
+
+	req->r_osdc = osdc;
+	req->r_mempool = use_mempool;
+	req->r_num_ops = num_ops;
+
+	kref_init(&req->r_kref);
+	init_completion(&req->r_completion);
+	init_completion(&req->r_safe_completion);
+	RB_CLEAR_NODE(&req->r_node);
+	INIT_LIST_HEAD(&req->r_unsafe_item);
+	INIT_LIST_HEAD(&req->r_linger_item);
+	INIT_LIST_HEAD(&req->r_linger_osd_item);
+	INIT_LIST_HEAD(&req->r_req_lru_item);
+	INIT_LIST_HEAD(&req->r_osd_item);
+
+	req->r_base_oloc.pool = -1;
+	req->r_target_oloc.pool = -1;
+
+	/* create reply message */
+	if (use_mempool)
+		msg = ceph_msgpool_get(&osdc->msgpool_op_reply, 0);
+	else
+		msg = ceph_msg_new(CEPH_MSG_OSD_OPREPLY,
+				   OSD_OPREPLY_FRONT_LEN, gfp_flags, true);
+	if (!msg) {
+		ceph_osdc_put_request(req);
+		return NULL;
+	}
+	req->r_reply = msg;
+
+	/* create request message; allow space for oid */
+	if (use_mempool)
+		msg = ceph_msgpool_get(&osdc->msgpool_op, 0);
+	else
+		msg = ceph_msg_new(CEPH_MSG_OSD_OP, msg_size, gfp_flags, true);
+	if (!msg) {
+		ceph_osdc_put_request(req);
+		return NULL;
+	}
+
+	memset(msg->front.iov_base, 0, msg->front.iov_len);
+
+	req->r_request = msg;
+
+	return req;
+}
+EXPORT_SYMBOL(ceph_osdc_alloc_request);
+
+static bool osd_req_opcode_valid(u16 opcode)
+{
+	switch (opcode) {
+#define GENERATE_CASE(op, opcode, str)	case CEPH_OSD_OP_##op: return true;
+__CEPH_FORALL_OSD_OPS(GENERATE_CASE)
+#undef GENERATE_CASE
+	default:
+		return false;
+	}
+}
+
+/*
+ * This is an osd op init function for opcodes that have no data or
+ * other information associated with them.  It also serves as a
+ * common init routine for all the other init functions, below.
+ */
+static struct ceph_osd_req_op *
+_osd_req_op_init(struct ceph_osd_request *osd_req, unsigned int which,
+				u16 opcode)
+{
+	struct ceph_osd_req_op *op;
+
+	BUG_ON(which >= osd_req->r_num_ops);
+	BUG_ON(!osd_req_opcode_valid(opcode));
+
+	op = &osd_req->r_ops[which];
+	memset(op, 0, sizeof (*op));
+	op->op = opcode;
+
+	return op;
+}
+
+void osd_req_op_init(struct ceph_osd_request *osd_req,
+				unsigned int which, u16 opcode)
+{
+	(void)_osd_req_op_init(osd_req, which, opcode);
+}
+EXPORT_SYMBOL(osd_req_op_init);
+
+void osd_req_op_extent_init(struct ceph_osd_request *osd_req,
+				unsigned int which, u16 opcode,
+				u64 offset, u64 length,
+				u64 truncate_size, u32 truncate_seq)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which, opcode);
+	size_t payload_len = 0;
+
+	BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
+	       opcode != CEPH_OSD_OP_ZERO && opcode != CEPH_OSD_OP_TRUNCATE);
+
+	op->extent.offset = offset;
+	op->extent.length = length;
+	op->extent.truncate_size = truncate_size;
+	op->extent.truncate_seq = truncate_seq;
+	if (opcode == CEPH_OSD_OP_WRITE)
+		payload_len += length;
+
+	op->payload_len = payload_len;
+}
+EXPORT_SYMBOL(osd_req_op_extent_init);
+
+void osd_req_op_extent_update(struct ceph_osd_request *osd_req,
+				unsigned int which, u64 length)
+{
+	struct ceph_osd_req_op *op;
+	u64 previous;
+
+	BUG_ON(which >= osd_req->r_num_ops);
+	op = &osd_req->r_ops[which];
+	previous = op->extent.length;
+
+	if (length == previous)
+		return;		/* Nothing to do */
+	BUG_ON(length > previous);
+
+	op->extent.length = length;
+	op->payload_len -= previous - length;
+}
+EXPORT_SYMBOL(osd_req_op_extent_update);
+
+void osd_req_op_cls_init(struct ceph_osd_request *osd_req, unsigned int which,
+			u16 opcode, const char *class, const char *method)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which, opcode);
+	struct ceph_pagelist *pagelist;
+	size_t payload_len = 0;
+	size_t size;
+
+	BUG_ON(opcode != CEPH_OSD_OP_CALL);
+
+	pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
+	BUG_ON(!pagelist);
+	ceph_pagelist_init(pagelist);
+
+	op->cls.class_name = class;
+	size = strlen(class);
+	BUG_ON(size > (size_t) U8_MAX);
+	op->cls.class_len = size;
+	ceph_pagelist_append(pagelist, class, size);
+	payload_len += size;
+
+	op->cls.method_name = method;
+	size = strlen(method);
+	BUG_ON(size > (size_t) U8_MAX);
+	op->cls.method_len = size;
+	ceph_pagelist_append(pagelist, method, size);
+	payload_len += size;
+
+	osd_req_op_cls_request_info_pagelist(osd_req, which, pagelist);
+
+	op->cls.argc = 0;	/* currently unused */
+
+	op->payload_len = payload_len;
+}
+EXPORT_SYMBOL(osd_req_op_cls_init);
+
+int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int which,
+			  u16 opcode, const char *name, const void *value,
+			  size_t size, u8 cmp_op, u8 cmp_mode)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which, opcode);
+	struct ceph_pagelist *pagelist;
+	size_t payload_len;
+
+	BUG_ON(opcode != CEPH_OSD_OP_SETXATTR && opcode != CEPH_OSD_OP_CMPXATTR);
+
+	pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
+	if (!pagelist)
+		return -ENOMEM;
+
+	ceph_pagelist_init(pagelist);
+
+	payload_len = strlen(name);
+	op->xattr.name_len = payload_len;
+	ceph_pagelist_append(pagelist, name, payload_len);
+
+	op->xattr.value_len = size;
+	ceph_pagelist_append(pagelist, value, size);
+	payload_len += size;
+
+	op->xattr.cmp_op = cmp_op;
+	op->xattr.cmp_mode = cmp_mode;
+
+	ceph_osd_data_pagelist_init(&op->xattr.osd_data, pagelist);
+	op->payload_len = payload_len;
+	return 0;
+}
+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)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which, opcode);
+
+	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;
+}
+EXPORT_SYMBOL(osd_req_op_watch_init);
+
+void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
+				unsigned int which,
+				u64 expected_object_size,
+				u64 expected_write_size)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
+						      CEPH_OSD_OP_SETALLOCHINT);
+
+	op->alloc_hint.expected_object_size = expected_object_size;
+	op->alloc_hint.expected_write_size = expected_write_size;
+
+	/*
+	 * CEPH_OSD_OP_SETALLOCHINT op is advisory and therefore deemed
+	 * not worth a feature bit.  Set FAILOK per-op flag to make
+	 * sure older osds don't trip over an unsupported opcode.
+	 */
+	op->flags |= CEPH_OSD_OP_FLAG_FAILOK;
+}
+EXPORT_SYMBOL(osd_req_op_alloc_hint_init);
+
+static void ceph_osdc_msg_data_add(struct ceph_msg *msg,
+				struct ceph_osd_data *osd_data)
+{
+	u64 length = ceph_osd_data_length(osd_data);
+
+	if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
+		BUG_ON(length > (u64) SIZE_MAX);
+		if (length)
+			ceph_msg_data_add_pages(msg, osd_data->pages,
+					length, osd_data->alignment);
+	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
+		BUG_ON(!length);
+		ceph_msg_data_add_pagelist(msg, osd_data->pagelist);
+#ifdef CONFIG_BLOCK
+	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
+		ceph_msg_data_add_bio(msg, osd_data->bio, length);
+#endif
+	} else {
+		BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_NONE);
+	}
+}
+
+static u64 osd_req_encode_op(struct ceph_osd_request *req,
+			      struct ceph_osd_op *dst, unsigned int which)
+{
+	struct ceph_osd_req_op *src;
+	struct ceph_osd_data *osd_data;
+	u64 request_data_len = 0;
+	u64 data_length;
+
+	BUG_ON(which >= req->r_num_ops);
+	src = &req->r_ops[which];
+	if (WARN_ON(!osd_req_opcode_valid(src->op))) {
+		pr_err("unrecognized osd opcode %d\n", src->op);
+
+		return 0;
+	}
+
+	switch (src->op) {
+	case CEPH_OSD_OP_STAT:
+		osd_data = &src->raw_data_in;
+		ceph_osdc_msg_data_add(req->r_reply, osd_data);
+		break;
+	case CEPH_OSD_OP_READ:
+	case CEPH_OSD_OP_WRITE:
+	case CEPH_OSD_OP_ZERO:
+	case CEPH_OSD_OP_TRUNCATE:
+		if (src->op == CEPH_OSD_OP_WRITE)
+			request_data_len = src->extent.length;
+		dst->extent.offset = cpu_to_le64(src->extent.offset);
+		dst->extent.length = cpu_to_le64(src->extent.length);
+		dst->extent.truncate_size =
+			cpu_to_le64(src->extent.truncate_size);
+		dst->extent.truncate_seq =
+			cpu_to_le32(src->extent.truncate_seq);
+		osd_data = &src->extent.osd_data;
+		if (src->op == CEPH_OSD_OP_WRITE)
+			ceph_osdc_msg_data_add(req->r_request, osd_data);
+		else
+			ceph_osdc_msg_data_add(req->r_reply, osd_data);
+		break;
+	case CEPH_OSD_OP_CALL:
+		dst->cls.class_len = src->cls.class_len;
+		dst->cls.method_len = src->cls.method_len;
+		osd_data = &src->cls.request_info;
+		ceph_osdc_msg_data_add(req->r_request, osd_data);
+		BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGELIST);
+		request_data_len = osd_data->pagelist->length;
+
+		osd_data = &src->cls.request_data;
+		data_length = ceph_osd_data_length(osd_data);
+		if (data_length) {
+			BUG_ON(osd_data->type == CEPH_OSD_DATA_TYPE_NONE);
+			dst->cls.indata_len = cpu_to_le32(data_length);
+			ceph_osdc_msg_data_add(req->r_request, osd_data);
+			src->payload_len += data_length;
+			request_data_len += data_length;
+		}
+		osd_data = &src->cls.response_data;
+		ceph_osdc_msg_data_add(req->r_reply, osd_data);
+		break;
+	case CEPH_OSD_OP_STARTSYNC:
+		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;
+		break;
+	case CEPH_OSD_OP_SETALLOCHINT:
+		dst->alloc_hint.expected_object_size =
+		    cpu_to_le64(src->alloc_hint.expected_object_size);
+		dst->alloc_hint.expected_write_size =
+		    cpu_to_le64(src->alloc_hint.expected_write_size);
+		break;
+	case CEPH_OSD_OP_SETXATTR:
+	case CEPH_OSD_OP_CMPXATTR:
+		dst->xattr.name_len = cpu_to_le32(src->xattr.name_len);
+		dst->xattr.value_len = cpu_to_le32(src->xattr.value_len);
+		dst->xattr.cmp_op = src->xattr.cmp_op;
+		dst->xattr.cmp_mode = src->xattr.cmp_mode;
+		osd_data = &src->xattr.osd_data;
+		ceph_osdc_msg_data_add(req->r_request, osd_data);
+		request_data_len = osd_data->pagelist->length;
+		break;
+	case CEPH_OSD_OP_CREATE:
+	case CEPH_OSD_OP_DELETE:
+		break;
+	default:
+		pr_err("unsupported osd opcode %s\n",
+			ceph_osd_op_name(src->op));
+		WARN_ON(1);
+
+		return 0;
+	}
+
+	dst->op = cpu_to_le16(src->op);
+	dst->flags = cpu_to_le32(src->flags);
+	dst->payload_len = cpu_to_le32(src->payload_len);
+
+	return request_data_len;
+}
+
+/*
+ * build new request AND message, calculate layout, and adjust file
+ * extent as needed.
+ *
+ * if the file was recently truncated, we include information about its
+ * old and new size so that the object can be updated appropriately.  (we
+ * avoid synchronously deleting truncated objects because it's slow.)
+ *
+ * if @do_sync, include a 'startsync' command so that the osd will flush
+ * data quickly.
+ */
+struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
+					       struct ceph_file_layout *layout,
+					       struct ceph_vino vino,
+					       u64 off, u64 *plen,
+					       unsigned int which, int num_ops,
+					       int opcode, int flags,
+					       struct ceph_snap_context *snapc,
+					       u32 truncate_seq,
+					       u64 truncate_size,
+					       bool use_mempool)
+{
+	struct ceph_osd_request *req;
+	u64 objnum = 0;
+	u64 objoff = 0;
+	u64 objlen = 0;
+	int r;
+
+	BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
+	       opcode != CEPH_OSD_OP_ZERO && opcode != CEPH_OSD_OP_TRUNCATE &&
+	       opcode != CEPH_OSD_OP_CREATE && opcode != CEPH_OSD_OP_DELETE);
+
+	req = ceph_osdc_alloc_request(osdc, snapc, num_ops, use_mempool,
+					GFP_NOFS);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	req->r_flags = flags;
+
+	/* calculate max write size */
+	r = calc_layout(layout, off, plen, &objnum, &objoff, &objlen);
+	if (r < 0) {
+		ceph_osdc_put_request(req);
+		return ERR_PTR(r);
+	}
+
+	if (opcode == CEPH_OSD_OP_CREATE || opcode == CEPH_OSD_OP_DELETE) {
+		osd_req_op_init(req, which, opcode);
+	} else {
+		u32 object_size = le32_to_cpu(layout->fl_object_size);
+		u32 object_base = off - objoff;
+		if (!(truncate_seq == 1 && truncate_size == -1ULL)) {
+			if (truncate_size <= object_base) {
+				truncate_size = 0;
+			} else {
+				truncate_size -= object_base;
+				if (truncate_size > object_size)
+					truncate_size = object_size;
+			}
+		}
+		osd_req_op_extent_init(req, which, opcode, objoff, objlen,
+				       truncate_size, truncate_seq);
+	}
+
+	req->r_base_oloc.pool = ceph_file_layout_pg_pool(*layout);
+
+	snprintf(req->r_base_oid.name, sizeof(req->r_base_oid.name),
+		 "%llx.%08llx", vino.ino, objnum);
+	req->r_base_oid.name_len = strlen(req->r_base_oid.name);
+
+	return req;
+}
+EXPORT_SYMBOL(ceph_osdc_new_request);
+
+/*
+ * We keep osd requests in an rbtree, sorted by ->r_tid.
+ */
+static void __insert_request(struct ceph_osd_client *osdc,
+			     struct ceph_osd_request *new)
+{
+	struct rb_node **p = &osdc->requests.rb_node;
+	struct rb_node *parent = NULL;
+	struct ceph_osd_request *req = NULL;
+
+	while (*p) {
+		parent = *p;
+		req = rb_entry(parent, struct ceph_osd_request, r_node);
+		if (new->r_tid < req->r_tid)
+			p = &(*p)->rb_left;
+		else if (new->r_tid > req->r_tid)
+			p = &(*p)->rb_right;
+		else
+			BUG();
+	}
+
+	rb_link_node(&new->r_node, parent, p);
+	rb_insert_color(&new->r_node, &osdc->requests);
+}
+
+static struct ceph_osd_request *__lookup_request(struct ceph_osd_client *osdc,
+						 u64 tid)
+{
+	struct ceph_osd_request *req;
+	struct rb_node *n = osdc->requests.rb_node;
+
+	while (n) {
+		req = rb_entry(n, struct ceph_osd_request, r_node);
+		if (tid < req->r_tid)
+			n = n->rb_left;
+		else if (tid > req->r_tid)
+			n = n->rb_right;
+		else
+			return req;
+	}
+	return NULL;
+}
+
+static struct ceph_osd_request *
+__lookup_request_ge(struct ceph_osd_client *osdc,
+		    u64 tid)
+{
+	struct ceph_osd_request *req;
+	struct rb_node *n = osdc->requests.rb_node;
+
+	while (n) {
+		req = rb_entry(n, struct ceph_osd_request, r_node);
+		if (tid < req->r_tid) {
+			if (!n->rb_left)
+				return req;
+			n = n->rb_left;
+		} else if (tid > req->r_tid) {
+			n = n->rb_right;
+		} else {
+			return req;
+		}
+	}
+	return NULL;
+}
+
+static void __kick_linger_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	struct ceph_osd *osd = req->r_osd;
+
+	/*
+	 * Linger requests need to be resent with a new tid to avoid
+	 * the dup op detection logic on the OSDs.  Achieve this with
+	 * a re-register dance instead of open-coding.
+	 */
+	ceph_osdc_get_request(req);
+	if (!list_empty(&req->r_linger_item))
+		__unregister_linger_request(osdc, req);
+	else
+		__unregister_request(osdc, req);
+	__register_request(osdc, req);
+	ceph_osdc_put_request(req);
+
+	/*
+	 * Unless request has been registered as both normal and
+	 * lingering, __unregister{,_linger}_request clears r_osd.
+	 * However, here we need to preserve r_osd to make sure we
+	 * requeue on the same OSD.
+	 */
+	WARN_ON(req->r_osd || !osd);
+	req->r_osd = osd;
+
+	dout("%s requeueing %p tid %llu\n", __func__, req, req->r_tid);
+	__enqueue_request(req);
+}
+
+/*
+ * 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;
+	LIST_HEAD(resend);
+	LIST_HEAD(resend_linger);
+	int err;
+
+	dout("%s osd%d\n", __func__, osd->o_osd);
+	err = __reset_osd(osdc, osd);
+	if (err)
+		return;
+
+	/*
+	 * Build up a list of requests to resend by traversing the
+	 * osd's list of requests.  Requests for a given object are
+	 * sent in tid order, and that is also the order they're
+	 * kept on this list.  Therefore all requests that are in
+	 * flight will be found first, followed by all requests that
+	 * have not yet been sent.  And to resend requests while
+	 * preserving this order we will want to put any sent
+	 * requests back on the front of the osd client's unsent
+	 * list.
+	 *
+	 * So we build a separate ordered list of already-sent
+	 * requests for the affected osd and splice it onto the
+	 * front of the osd client's unsent list.  Once we've seen a
+	 * request that has not yet been sent we're done.  Those
+	 * requests are already sitting right where they belong.
+	 */
+	list_for_each_entry(req, &osd->o_requests, r_osd_item) {
+		if (!req->r_sent)
+			break;
+
+		if (!req->r_linger) {
+			dout("%s requeueing %p tid %llu\n", __func__, req,
+			     req->r_tid);
+			list_move_tail(&req->r_req_lru_item, &resend);
+			req->r_flags |= CEPH_OSD_FLAG_RETRY;
+		} else {
+			list_move_tail(&req->r_req_lru_item, &resend_linger);
+		}
+	}
+	list_splice(&resend, &osdc->req_unsent);
+
+	/*
+	 * Both registered and not yet registered linger requests are
+	 * enqueued with a new tid on the same OSD.  We add/move them
+	 * to req_unsent/o_requests at the end to keep things in tid
+	 * order.
+	 */
+	list_for_each_entry_safe(req, nreq, &osd->o_linger_requests,
+				 r_linger_osd_item) {
+		WARN_ON(!list_empty(&req->r_req_lru_item));
+		__kick_linger_request(req);
+	}
+
+	list_for_each_entry_safe(req, nreq, &resend_linger, r_req_lru_item)
+		__kick_linger_request(req);
+}
+
+/*
+ * If the osd connection drops, we need to resubmit all requests.
+ */
+static void osd_reset(struct ceph_connection *con)
+{
+	struct ceph_osd *osd = con->private;
+	struct ceph_osd_client *osdc;
+
+	if (!osd)
+		return;
+	dout("osd_reset osd%d\n", osd->o_osd);
+	osdc = osd->o_osdc;
+	down_read(&osdc->map_sem);
+	mutex_lock(&osdc->request_mutex);
+	__kick_osd_requests(osdc, osd);
+	__send_queued(osdc);
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+}
+
+/*
+ * Track open sessions with osds.
+ */
+static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
+{
+	struct ceph_osd *osd;
+
+	osd = kzalloc(sizeof(*osd), GFP_NOFS);
+	if (!osd)
+		return NULL;
+
+	atomic_set(&osd->o_ref, 1);
+	osd->o_osdc = osdc;
+	osd->o_osd = onum;
+	RB_CLEAR_NODE(&osd->o_node);
+	INIT_LIST_HEAD(&osd->o_requests);
+	INIT_LIST_HEAD(&osd->o_linger_requests);
+	INIT_LIST_HEAD(&osd->o_osd_lru);
+	osd->o_incarnation = 1;
+
+	ceph_con_init(&osd->o_con, osd, &osd_con_ops, &osdc->client->msgr);
+
+	INIT_LIST_HEAD(&osd->o_keepalive_item);
+	return osd;
+}
+
+static struct ceph_osd *get_osd(struct ceph_osd *osd)
+{
+	if (atomic_inc_not_zero(&osd->o_ref)) {
+		dout("get_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref)-1,
+		     atomic_read(&osd->o_ref));
+		return osd;
+	} else {
+		dout("get_osd %p FAIL\n", osd);
+		return NULL;
+	}
+}
+
+static void put_osd(struct ceph_osd *osd)
+{
+	dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref),
+	     atomic_read(&osd->o_ref) - 1);
+	if (atomic_dec_and_test(&osd->o_ref)) {
+		struct ceph_auth_client *ac = osd->o_osdc->client->monc.auth;
+
+		if (osd->o_auth.authorizer)
+			ceph_auth_destroy_authorizer(ac, osd->o_auth.authorizer);
+		kfree(osd);
+	}
+}
+
+/*
+ * remove an osd from our map
+ */
+static void __remove_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
+{
+	dout("%s %p osd%d\n", __func__, osd, osd->o_osd);
+	WARN_ON(!list_empty(&osd->o_requests));
+	WARN_ON(!list_empty(&osd->o_linger_requests));
+
+	list_del_init(&osd->o_osd_lru);
+	rb_erase(&osd->o_node, &osdc->osds);
+	RB_CLEAR_NODE(&osd->o_node);
+}
+
+static void remove_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
+{
+	dout("%s %p osd%d\n", __func__, osd, osd->o_osd);
+
+	if (!RB_EMPTY_NODE(&osd->o_node)) {
+		ceph_con_close(&osd->o_con);
+		__remove_osd(osdc, osd);
+		put_osd(osd);
+	}
+}
+
+static void remove_all_osds(struct ceph_osd_client *osdc)
+{
+	dout("%s %p\n", __func__, osdc);
+	mutex_lock(&osdc->request_mutex);
+	while (!RB_EMPTY_ROOT(&osdc->osds)) {
+		struct ceph_osd *osd = rb_entry(rb_first(&osdc->osds),
+						struct ceph_osd, o_node);
+		remove_osd(osdc, osd);
+	}
+	mutex_unlock(&osdc->request_mutex);
+}
+
+static void __move_osd_to_lru(struct ceph_osd_client *osdc,
+			      struct ceph_osd *osd)
+{
+	dout("%s %p\n", __func__, osd);
+	BUG_ON(!list_empty(&osd->o_osd_lru));
+
+	list_add_tail(&osd->o_osd_lru, &osdc->osd_lru);
+	osd->lru_ttl = jiffies + osdc->client->options->osd_idle_ttl * HZ;
+}
+
+static void maybe_move_osd_to_lru(struct ceph_osd_client *osdc,
+				  struct ceph_osd *osd)
+{
+	dout("%s %p\n", __func__, osd);
+
+	if (list_empty(&osd->o_requests) &&
+	    list_empty(&osd->o_linger_requests))
+		__move_osd_to_lru(osdc, osd);
+}
+
+static void __remove_osd_from_lru(struct ceph_osd *osd)
+{
+	dout("__remove_osd_from_lru %p\n", osd);
+	if (!list_empty(&osd->o_osd_lru))
+		list_del_init(&osd->o_osd_lru);
+}
+
+static void remove_old_osds(struct ceph_osd_client *osdc)
+{
+	struct ceph_osd *osd, *nosd;
+
+	dout("__remove_old_osds %p\n", osdc);
+	mutex_lock(&osdc->request_mutex);
+	list_for_each_entry_safe(osd, nosd, &osdc->osd_lru, o_osd_lru) {
+		if (time_before(jiffies, osd->lru_ttl))
+			break;
+		remove_osd(osdc, osd);
+	}
+	mutex_unlock(&osdc->request_mutex);
+}
+
+/*
+ * reset osd connect
+ */
+static int __reset_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
+{
+	struct ceph_entity_addr *peer_addr;
+
+	dout("__reset_osd %p osd%d\n", osd, osd->o_osd);
+	if (list_empty(&osd->o_requests) &&
+	    list_empty(&osd->o_linger_requests)) {
+		remove_osd(osdc, osd);
+		return -ENODEV;
+	}
+
+	peer_addr = &osdc->osdmap->osd_addr[osd->o_osd];
+	if (!memcmp(peer_addr, &osd->o_con.peer_addr, sizeof (*peer_addr)) &&
+			!ceph_con_opened(&osd->o_con)) {
+		struct ceph_osd_request *req;
+
+		dout("osd addr hasn't changed and connection never opened, "
+		     "letting msgr retry\n");
+		/* touch each r_stamp for handle_timeout()'s benfit */
+		list_for_each_entry(req, &osd->o_requests, r_osd_item)
+			req->r_stamp = jiffies;
+
+		return -EAGAIN;
+	}
+
+	ceph_con_close(&osd->o_con);
+	ceph_con_open(&osd->o_con, CEPH_ENTITY_TYPE_OSD, osd->o_osd, peer_addr);
+	osd->o_incarnation++;
+
+	return 0;
+}
+
+static void __insert_osd(struct ceph_osd_client *osdc, struct ceph_osd *new)
+{
+	struct rb_node **p = &osdc->osds.rb_node;
+	struct rb_node *parent = NULL;
+	struct ceph_osd *osd = NULL;
+
+	dout("__insert_osd %p osd%d\n", new, new->o_osd);
+	while (*p) {
+		parent = *p;
+		osd = rb_entry(parent, struct ceph_osd, o_node);
+		if (new->o_osd < osd->o_osd)
+			p = &(*p)->rb_left;
+		else if (new->o_osd > osd->o_osd)
+			p = &(*p)->rb_right;
+		else
+			BUG();
+	}
+
+	rb_link_node(&new->o_node, parent, p);
+	rb_insert_color(&new->o_node, &osdc->osds);
+}
+
+static struct ceph_osd *__lookup_osd(struct ceph_osd_client *osdc, int o)
+{
+	struct ceph_osd *osd;
+	struct rb_node *n = osdc->osds.rb_node;
+
+	while (n) {
+		osd = rb_entry(n, struct ceph_osd, o_node);
+		if (o < osd->o_osd)
+			n = n->rb_left;
+		else if (o > osd->o_osd)
+			n = n->rb_right;
+		else
+			return osd;
+	}
+	return NULL;
+}
+
+static void __schedule_osd_timeout(struct ceph_osd_client *osdc)
+{
+	schedule_delayed_work(&osdc->timeout_work,
+			osdc->client->options->osd_keepalive_timeout * HZ);
+}
+
+static void __cancel_osd_timeout(struct ceph_osd_client *osdc)
+{
+	cancel_delayed_work(&osdc->timeout_work);
+}
+
+/*
+ * 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)
+{
+	req->r_tid = ++osdc->last_tid;
+	req->r_request->hdr.tid = cpu_to_le64(req->r_tid);
+	dout("__register_request %p tid %lld\n", req, req->r_tid);
+	__insert_request(osdc, req);
+	ceph_osdc_get_request(req);
+	osdc->num_requests++;
+	if (osdc->num_requests == 1) {
+		dout(" first request, scheduling timeout\n");
+		__schedule_osd_timeout(osdc);
+	}
+}
+
+/*
+ * called under osdc->request_mutex
+ */
+static void __unregister_request(struct ceph_osd_client *osdc,
+				 struct ceph_osd_request *req)
+{
+	if (RB_EMPTY_NODE(&req->r_node)) {
+		dout("__unregister_request %p tid %lld not registered\n",
+			req, req->r_tid);
+		return;
+	}
+
+	dout("__unregister_request %p tid %lld\n", req, req->r_tid);
+	rb_erase(&req->r_node, &osdc->requests);
+	RB_CLEAR_NODE(&req->r_node);
+	osdc->num_requests--;
+
+	if (req->r_osd) {
+		/* make sure the original request isn't in flight. */
+		ceph_msg_revoke(req->r_request);
+
+		list_del_init(&req->r_osd_item);
+		maybe_move_osd_to_lru(osdc, req->r_osd);
+		if (list_empty(&req->r_linger_osd_item))
+			req->r_osd = NULL;
+	}
+
+	list_del_init(&req->r_req_lru_item);
+	ceph_osdc_put_request(req);
+
+	if (osdc->num_requests == 0) {
+		dout(" no requests, canceling timeout\n");
+		__cancel_osd_timeout(osdc);
+	}
+}
+
+/*
+ * Cancel a previously queued request message
+ */
+static void __cancel_request(struct ceph_osd_request *req)
+{
+	if (req->r_sent && req->r_osd) {
+		ceph_msg_revoke(req->r_request);
+		req->r_sent = 0;
+	}
+}
+
+static void __register_linger_request(struct ceph_osd_client *osdc,
+				    struct ceph_osd_request *req)
+{
+	dout("%s %p tid %llu\n", __func__, req, req->r_tid);
+	WARN_ON(!req->r_linger);
+
+	ceph_osdc_get_request(req);
+	list_add_tail(&req->r_linger_item, &osdc->req_linger);
+	if (req->r_osd)
+		list_add_tail(&req->r_linger_osd_item,
+			      &req->r_osd->o_linger_requests);
+}
+
+static void __unregister_linger_request(struct ceph_osd_client *osdc,
+					struct ceph_osd_request *req)
+{
+	WARN_ON(!req->r_linger);
+
+	if (list_empty(&req->r_linger_item)) {
+		dout("%s %p tid %llu not registered\n", __func__, req,
+		     req->r_tid);
+		return;
+	}
+
+	dout("%s %p tid %llu\n", __func__, req, req->r_tid);
+	list_del_init(&req->r_linger_item);
+
+	if (req->r_osd) {
+		list_del_init(&req->r_linger_osd_item);
+		maybe_move_osd_to_lru(osdc, req->r_osd);
+		if (list_empty(&req->r_osd_item))
+			req->r_osd = NULL;
+	}
+	ceph_osdc_put_request(req);
+}
+
+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;
+	}
+}
+EXPORT_SYMBOL(ceph_osdc_set_request_linger);
+
+/*
+ * Returns whether a request should be blocked from being sent
+ * based on the current osdmap and osd_client settings.
+ *
+ * Caller should hold map_sem for read.
+ */
+static bool __req_should_be_paused(struct ceph_osd_client *osdc,
+				   struct ceph_osd_request *req)
+{
+	bool pauserd = ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_PAUSERD);
+	bool pausewr = ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_PAUSEWR) ||
+		ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL);
+	return (req->r_flags & CEPH_OSD_FLAG_READ && pauserd) ||
+		(req->r_flags & CEPH_OSD_FLAG_WRITE && pausewr);
+}
+
+/*
+ * Calculate mapping of a request to a PG.  Takes tiering into account.
+ */
+static int __calc_request_pg(struct ceph_osdmap *osdmap,
+			     struct ceph_osd_request *req,
+			     struct ceph_pg *pg_out)
+{
+	bool need_check_tiering;
+
+	need_check_tiering = false;
+	if (req->r_target_oloc.pool == -1) {
+		req->r_target_oloc = req->r_base_oloc; /* struct */
+		need_check_tiering = true;
+	}
+	if (req->r_target_oid.name_len == 0) {
+		ceph_oid_copy(&req->r_target_oid, &req->r_base_oid);
+		need_check_tiering = true;
+	}
+
+	if (need_check_tiering &&
+	    (req->r_flags & CEPH_OSD_FLAG_IGNORE_OVERLAY) == 0) {
+		struct ceph_pg_pool_info *pi;
+
+		pi = ceph_pg_pool_by_id(osdmap, req->r_target_oloc.pool);
+		if (pi) {
+			if ((req->r_flags & CEPH_OSD_FLAG_READ) &&
+			    pi->read_tier >= 0)
+				req->r_target_oloc.pool = pi->read_tier;
+			if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
+			    pi->write_tier >= 0)
+				req->r_target_oloc.pool = pi->write_tier;
+		}
+		/* !pi is caught in ceph_oloc_oid_to_pg() */
+	}
+
+	return ceph_oloc_oid_to_pg(osdmap, &req->r_target_oloc,
+				   &req->r_target_oid, pg_out);
+}
+
+static void __enqueue_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+
+	dout("%s %p tid %llu to osd%d\n", __func__, req, req->r_tid,
+	     req->r_osd ? req->r_osd->o_osd : -1);
+
+	if (req->r_osd) {
+		__remove_osd_from_lru(req->r_osd);
+		list_add_tail(&req->r_osd_item, &req->r_osd->o_requests);
+		list_move_tail(&req->r_req_lru_item, &osdc->req_unsent);
+	} else {
+		list_move_tail(&req->r_req_lru_item, &osdc->req_notarget);
+	}
+}
+
+/*
+ * 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.  Move the request to the appropriate 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_request(struct ceph_osd_client *osdc,
+			 struct ceph_osd_request *req, int force_resend)
+{
+	struct ceph_pg pgid;
+	int acting[CEPH_PG_MAX_SIZE];
+	int num, o;
+	int err;
+	bool was_paused;
+
+	dout("map_request %p tid %lld\n", req, req->r_tid);
+
+	err = __calc_request_pg(osdc->osdmap, req, &pgid);
+	if (err) {
+		list_move(&req->r_req_lru_item, &osdc->req_notarget);
+		return err;
+	}
+	req->r_pgid = pgid;
+
+	num = ceph_calc_pg_acting(osdc->osdmap, pgid, acting, &o);
+	if (num < 0)
+		num = 0;
+
+	was_paused = req->r_paused;
+	req->r_paused = __req_should_be_paused(osdc, req);
+	if (was_paused && !req->r_paused)
+		force_resend = 1;
+
+	if ((!force_resend &&
+	     req->r_osd && req->r_osd->o_osd == o &&
+	     req->r_sent >= req->r_osd->o_incarnation &&
+	     req->r_num_pg_osds == num &&
+	     memcmp(req->r_pg_osds, acting, sizeof(acting[0])*num) == 0) ||
+	    (req->r_osd == NULL && o == -1) ||
+	    req->r_paused)
+		return 0;  /* no change */
+
+	dout("map_request tid %llu pgid %lld.%x osd%d (was osd%d)\n",
+	     req->r_tid, pgid.pool, pgid.seed, o,
+	     req->r_osd ? req->r_osd->o_osd : -1);
+
+	/* record full pg acting set */
+	memcpy(req->r_pg_osds, acting, sizeof(acting[0]) * num);
+	req->r_num_pg_osds = num;
+
+	if (req->r_osd) {
+		__cancel_request(req);
+		list_del_init(&req->r_osd_item);
+		list_del_init(&req->r_linger_osd_item);
+		req->r_osd = NULL;
+	}
+
+	req->r_osd = __lookup_osd(osdc, o);
+	if (!req->r_osd && o >= 0) {
+		err = -ENOMEM;
+		req->r_osd = create_osd(osdc, o);
+		if (!req->r_osd) {
+			list_move(&req->r_req_lru_item, &osdc->req_notarget);
+			goto out;
+		}
+
+		dout("map_request osd %p is osd%d\n", req->r_osd, o);
+		__insert_osd(osdc, req->r_osd);
+
+		ceph_con_open(&req->r_osd->o_con,
+			      CEPH_ENTITY_TYPE_OSD, o,
+			      &osdc->osdmap->osd_addr[o]);
+	}
+
+	__enqueue_request(req);
+	err = 1;   /* osd or pg changed */
+
+out:
+	return err;
+}
+
+/*
+ * caller should hold map_sem (for read) and request_mutex
+ */
+static void __send_request(struct ceph_osd_client *osdc,
+			   struct ceph_osd_request *req)
+{
+	void *p;
+
+	dout("send_request %p tid %llu to osd%d flags %d pg %lld.%x\n",
+	     req, req->r_tid, req->r_osd->o_osd, req->r_flags,
+	     (unsigned long long)req->r_pgid.pool, req->r_pgid.seed);
+
+	/* fill in message content that changes each time we send it */
+	put_unaligned_le32(osdc->osdmap->epoch, req->r_request_osdmap_epoch);
+	put_unaligned_le32(req->r_flags, req->r_request_flags);
+	put_unaligned_le64(req->r_target_oloc.pool, req->r_request_pool);
+	p = req->r_request_pgid;
+	ceph_encode_64(&p, req->r_pgid.pool);
+	ceph_encode_32(&p, req->r_pgid.seed);
+	put_unaligned_le64(1, req->r_request_attempts);  /* FIXME */
+	memcpy(req->r_request_reassert_version, &req->r_reassert_version,
+	       sizeof(req->r_reassert_version));
+
+	req->r_stamp = jiffies;
+	list_move_tail(&req->r_req_lru_item, &osdc->req_lru);
+
+	ceph_msg_get(req->r_request); /* send consumes a ref */
+
+	req->r_sent = req->r_osd->o_incarnation;
+
+	ceph_con_send(&req->r_osd->o_con, req->r_request);
+}
+
+/*
+ * 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");
+	list_for_each_entry_safe(req, tmp, &osdc->req_unsent, r_req_lru_item)
+		__send_request(osdc, req);
+}
+
+/*
+ * Caller should hold map_sem for read and request_mutex.
+ */
+static int __ceph_osdc_start_request(struct ceph_osd_client *osdc,
+				     struct ceph_osd_request *req,
+				     bool nofail)
+{
+	int rc;
+
+	__register_request(osdc, req);
+	req->r_sent = 0;
+	req->r_got_reply = 0;
+	rc = __map_request(osdc, req, 0);
+	if (rc < 0) {
+		if (nofail) {
+			dout("osdc_start_request failed map, "
+				" will retry %lld\n", req->r_tid);
+			rc = 0;
+		} else {
+			__unregister_request(osdc, req);
+		}
+		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 {
+		__send_queued(osdc);
+	}
+
+	return 0;
+}
+
+/*
+ * Timeout callback, called every N seconds when 1 or more osd
+ * requests has been active for more than N seconds.  When this
+ * happens, we ping all OSDs with requests who have timed out to
+ * ensure any communications channel reset is detected.  Reset the
+ * request timeouts another N seconds in the future as we go.
+ * Reschedule the timeout event another N seconds in future (unless
+ * there are no open requests).
+ */
+static void handle_timeout(struct work_struct *work)
+{
+	struct ceph_osd_client *osdc =
+		container_of(work, struct ceph_osd_client, timeout_work.work);
+	struct ceph_osd_request *req;
+	struct ceph_osd *osd;
+	unsigned long keepalive =
+		osdc->client->options->osd_keepalive_timeout * HZ;
+	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);
+
+	/*
+	 * ping osds that are a bit slow.  this ensures that if there
+	 * is a break in the TCP connection we will notice, and reopen
+	 * a connection with that osd (from the fault callback).
+	 */
+	INIT_LIST_HEAD(&slow_osds);
+	list_for_each_entry(req, &osdc->req_lru, r_req_lru_item) {
+		if (time_before(jiffies, req->r_stamp + keepalive))
+			break;
+
+		osd = req->r_osd;
+		BUG_ON(!osd);
+		dout(" tid %llu is slow, will send keepalive on osd%d\n",
+		     req->r_tid, osd->o_osd);
+		list_move_tail(&osd->o_keepalive_item, &slow_osds);
+	}
+	while (!list_empty(&slow_osds)) {
+		osd = list_entry(slow_osds.next, struct ceph_osd,
+				 o_keepalive_item);
+		list_del_init(&osd->o_keepalive_item);
+		ceph_con_keepalive(&osd->o_con);
+	}
+
+	__schedule_osd_timeout(osdc);
+	__send_queued(osdc);
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+}
+
+static void handle_osds_timeout(struct work_struct *work)
+{
+	struct ceph_osd_client *osdc =
+		container_of(work, struct ceph_osd_client,
+			     osds_timeout_work.work);
+	unsigned long delay =
+		osdc->client->options->osd_idle_ttl * HZ >> 2;
+
+	dout("osds timeout\n");
+	down_read(&osdc->map_sem);
+	remove_old_osds(osdc);
+	up_read(&osdc->map_sem);
+
+	schedule_delayed_work(&osdc->osds_timeout_work,
+			      round_jiffies_relative(delay));
+}
+
+static int ceph_oloc_decode(void **p, void *end,
+			    struct ceph_object_locator *oloc)
+{
+	u8 struct_v, struct_cv;
+	u32 len;
+	void *struct_end;
+	int ret = 0;
+
+	ceph_decode_need(p, end, 1 + 1 + 4, e_inval);
+	struct_v = ceph_decode_8(p);
+	struct_cv = ceph_decode_8(p);
+	if (struct_v < 3) {
+		pr_warn("got v %d < 3 cv %d of ceph_object_locator\n",
+			struct_v, struct_cv);
+		goto e_inval;
+	}
+	if (struct_cv > 6) {
+		pr_warn("got v %d cv %d > 6 of ceph_object_locator\n",
+			struct_v, struct_cv);
+		goto e_inval;
+	}
+	len = ceph_decode_32(p);
+	ceph_decode_need(p, end, len, e_inval);
+	struct_end = *p + len;
+
+	oloc->pool = ceph_decode_64(p);
+	*p += 4; /* skip preferred */
+
+	len = ceph_decode_32(p);
+	if (len > 0) {
+		pr_warn("ceph_object_locator::key is set\n");
+		goto e_inval;
+	}
+
+	if (struct_v >= 5) {
+		len = ceph_decode_32(p);
+		if (len > 0) {
+			pr_warn("ceph_object_locator::nspace is set\n");
+			goto e_inval;
+		}
+	}
+
+	if (struct_v >= 6) {
+		s64 hash = ceph_decode_64(p);
+		if (hash != -1) {
+			pr_warn("ceph_object_locator::hash is set\n");
+			goto e_inval;
+		}
+	}
+
+	/* skip the rest */
+	*p = struct_end;
+out:
+	return ret;
+
+e_inval:
+	ret = -EINVAL;
+	goto out;
+}
+
+static int ceph_redirect_decode(void **p, void *end,
+				struct ceph_request_redirect *redir)
+{
+	u8 struct_v, struct_cv;
+	u32 len;
+	void *struct_end;
+	int ret;
+
+	ceph_decode_need(p, end, 1 + 1 + 4, e_inval);
+	struct_v = ceph_decode_8(p);
+	struct_cv = ceph_decode_8(p);
+	if (struct_cv > 1) {
+		pr_warn("got v %d cv %d > 1 of ceph_request_redirect\n",
+			struct_v, struct_cv);
+		goto e_inval;
+	}
+	len = ceph_decode_32(p);
+	ceph_decode_need(p, end, len, e_inval);
+	struct_end = *p + len;
+
+	ret = ceph_oloc_decode(p, end, &redir->oloc);
+	if (ret)
+		goto out;
+
+	len = ceph_decode_32(p);
+	if (len > 0) {
+		pr_warn("ceph_request_redirect::object_name is set\n");
+		goto e_inval;
+	}
+
+	len = ceph_decode_32(p);
+	*p += len; /* skip osd_instructions */
+
+	/* skip the rest */
+	*p = struct_end;
+out:
+	return ret;
+
+e_inval:
+	ret = -EINVAL;
+	goto out;
+}
+
+static void complete_request(struct ceph_osd_request *req)
+{
+	complete_all(&req->r_safe_completion);  /* fsync waiter */
+}
+
+/*
+ * handle osd op reply.  either call the callback if it is specified,
+ * or do the completion to wake up the waiting thread.
+ */
+static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
+			 struct ceph_connection *con)
+{
+	void *p, *end;
+	struct ceph_osd_request *req;
+	struct ceph_request_redirect redir;
+	u64 tid;
+	int object_len;
+	unsigned int numops;
+	int payload_len, flags;
+	s32 result;
+	s32 retry_attempt;
+	struct ceph_pg pg;
+	int err;
+	u32 reassert_epoch;
+	u64 reassert_version;
+	u32 osdmap_epoch;
+	int already_completed;
+	u32 bytes;
+	unsigned int i;
+
+	tid = le64_to_cpu(msg->hdr.tid);
+	dout("handle_reply %p tid %llu\n", msg, tid);
+
+	p = msg->front.iov_base;
+	end = p + msg->front.iov_len;
+
+	ceph_decode_need(&p, end, 4, bad);
+	object_len = ceph_decode_32(&p);
+	ceph_decode_need(&p, end, object_len, bad);
+	p += object_len;
+
+	err = ceph_decode_pgid(&p, end, &pg);
+	if (err)
+		goto bad;
+
+	ceph_decode_need(&p, end, 8 + 4 + 4 + 8 + 4, bad);
+	flags = ceph_decode_64(&p);
+	result = ceph_decode_32(&p);
+	reassert_epoch = ceph_decode_32(&p);
+	reassert_version = ceph_decode_64(&p);
+	osdmap_epoch = ceph_decode_32(&p);
+
+	/* lookup */
+	down_read(&osdc->map_sem);
+	mutex_lock(&osdc->request_mutex);
+	req = __lookup_request(osdc, tid);
+	if (req == NULL) {
+		dout("handle_reply tid %llu dne\n", tid);
+		goto bad_mutex;
+	}
+	ceph_osdc_get_request(req);
+
+	dout("handle_reply %p tid %llu req %p result %d\n", msg, tid,
+	     req, result);
+
+	ceph_decode_need(&p, end, 4, bad_put);
+	numops = ceph_decode_32(&p);
+	if (numops > CEPH_OSD_MAX_OP)
+		goto bad_put;
+	if (numops != req->r_num_ops)
+		goto bad_put;
+	payload_len = 0;
+	ceph_decode_need(&p, end, numops * sizeof(struct ceph_osd_op), bad_put);
+	for (i = 0; i < numops; i++) {
+		struct ceph_osd_op *op = p;
+		int len;
+
+		len = le32_to_cpu(op->payload_len);
+		req->r_reply_op_len[i] = len;
+		dout(" op %d has %d bytes\n", i, len);
+		payload_len += len;
+		p += sizeof(*op);
+	}
+	bytes = le32_to_cpu(msg->hdr.data_len);
+	if (payload_len != bytes) {
+		pr_warn("sum of op payload lens %d != data_len %d\n",
+			payload_len, bytes);
+		goto bad_put;
+	}
+
+	ceph_decode_need(&p, end, 4 + numops * 4, bad_put);
+	retry_attempt = ceph_decode_32(&p);
+	for (i = 0; i < numops; i++)
+		req->r_reply_op_result[i] = ceph_decode_32(&p);
+
+	if (le16_to_cpu(msg->hdr.version) >= 6) {
+		p += 8 + 4; /* skip replay_version */
+		p += 8; /* skip user_version */
+
+		err = ceph_redirect_decode(&p, end, &redir);
+		if (err)
+			goto bad_put;
+	} else {
+		redir.oloc.pool = -1;
+	}
+
+	if (redir.oloc.pool != -1) {
+		dout("redirect pool %lld\n", redir.oloc.pool);
+
+		__unregister_request(osdc, req);
+
+		req->r_target_oloc = redir.oloc; /* struct */
+
+		/*
+		 * Start redirect requests with nofail=true.  If
+		 * mapping fails, request will end up on the notarget
+		 * list, waiting for the new osdmap (which can take
+		 * a while), even though the original request mapped
+		 * successfully.  In the future we might want to follow
+		 * original request's nofail setting here.
+		 */
+		err = __ceph_osdc_start_request(osdc, req, true);
+		BUG_ON(err);
+
+		goto out_unlock;
+	}
+
+	already_completed = req->r_got_reply;
+	if (!req->r_got_reply) {
+		req->r_result = result;
+		dout("handle_reply result %d bytes %d\n", req->r_result,
+		     bytes);
+		if (req->r_result == 0)
+			req->r_result = bytes;
+
+		/* in case this is a write and we need to replay, */
+		req->r_reassert_version.epoch = cpu_to_le32(reassert_epoch);
+		req->r_reassert_version.version = cpu_to_le64(reassert_version);
+
+		req->r_got_reply = 1;
+	} else if ((flags & CEPH_OSD_FLAG_ONDISK) == 0) {
+		dout("handle_reply tid %llu dup ack\n", tid);
+		goto out_unlock;
+	}
+
+	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) ||
+	    ((flags & CEPH_OSD_FLAG_WRITE) == 0))
+		__unregister_request(osdc, req);
+
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+
+	if (!already_completed) {
+		if (req->r_unsafe_callback &&
+		    result >= 0 && !(flags & CEPH_OSD_FLAG_ONDISK))
+			req->r_unsafe_callback(req, true);
+		if (req->r_callback)
+			req->r_callback(req, msg);
+		else
+			complete_all(&req->r_completion);
+	}
+
+	if (flags & CEPH_OSD_FLAG_ONDISK) {
+		if (req->r_unsafe_callback && already_completed)
+			req->r_unsafe_callback(req, false);
+		complete_request(req);
+	}
+
+out:
+	dout("req=%p req->r_linger=%d\n", req, req->r_linger);
+	ceph_osdc_put_request(req);
+	return;
+out_unlock:
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+	goto out;
+
+bad_put:
+	req->r_result = -EIO;
+	__unregister_request(osdc, req);
+	if (req->r_callback)
+		req->r_callback(req, msg);
+	else
+		complete_all(&req->r_completion);
+	complete_request(req);
+	ceph_osdc_put_request(req);
+bad_mutex:
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+bad:
+	pr_err("corrupt osd_op_reply got %d %d\n",
+	       (int)msg->front.iov_len, le32_to_cpu(msg->hdr.front_len));
+	ceph_msg_dump(msg);
+}
+
+static void reset_changed_osds(struct ceph_osd_client *osdc)
+{
+	struct rb_node *p, *n;
+
+	dout("%s %p\n", __func__, osdc);
+	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.
+ */
+static void kick_requests(struct ceph_osd_client *osdc, bool force_resend,
+			  bool force_resend_writes)
+{
+	struct ceph_osd_request *req, *nreq;
+	struct rb_node *p;
+	int needmap = 0;
+	int err;
+	bool force_resend_req;
+
+	dout("kick_requests %s %s\n", force_resend ? " (force resend)" : "",
+		force_resend_writes ? " (force resend writes)" : "");
+	mutex_lock(&osdc->request_mutex);
+	for (p = rb_first(&osdc->requests); p; ) {
+		req = rb_entry(p, struct ceph_osd_request, r_node);
+		p = rb_next(p);
+
+		/*
+		 * For linger requests that have not yet been
+		 * registered, move them to the linger list; they'll
+		 * be sent to the osd in the loop below.  Unregister
+		 * the request before re-registering it as a linger
+		 * request to ensure the __map_request() below
+		 * will decide it needs to be sent.
+		 */
+		if (req->r_linger && list_empty(&req->r_linger_item)) {
+			dout("%p tid %llu restart on osd%d\n",
+			     req, req->r_tid,
+			     req->r_osd ? req->r_osd->o_osd : -1);
+			ceph_osdc_get_request(req);
+			__unregister_request(osdc, req);
+			__register_linger_request(osdc, req);
+			ceph_osdc_put_request(req);
+			continue;
+		}
+
+		force_resend_req = force_resend ||
+			(force_resend_writes &&
+				req->r_flags & CEPH_OSD_FLAG_WRITE);
+		err = __map_request(osdc, req, force_resend_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) {
+			if (!req->r_linger) {
+				dout("%p tid %llu requeued on osd%d\n", req,
+				     req->r_tid,
+				     req->r_osd ? req->r_osd->o_osd : -1);
+				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_request(osdc, req,
+				    force_resend || force_resend_writes);
+		dout("__map_request returned %d\n", err);
+		if (err < 0)
+			continue;  /* hrm! */
+		if (req->r_osd == NULL || err > 0) {
+			if (req->r_osd == NULL) {
+				dout("lingering %p tid %llu maps to no osd\n",
+				     req, req->r_tid);
+				/*
+				 * A homeless lingering request makes
+				 * no sense, as it's job is to keep
+				 * a particular OSD connection open.
+				 * Request a newer map and kick the
+				 * request, knowing that it won't be
+				 * resent until we actually get a map
+				 * that can tell us where to send it.
+				 */
+				needmap++;
+			}
+
+			dout("kicking lingering %p tid %llu osd%d\n", req,
+			     req->r_tid, req->r_osd ? req->r_osd->o_osd : -1);
+			__register_request(osdc, req);
+			__unregister_linger_request(osdc, req);
+		}
+	}
+	reset_changed_osds(osdc);
+	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.
+ *
+ * The message contains any number of incremental and full maps, normally
+ * indicating some sort of topology change in the cluster.  Kick requests
+ * off to different OSDs as needed.
+ */
+void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
+{
+	void *p, *end, *next;
+	u32 nr_maps, maplen;
+	u32 epoch;
+	struct ceph_osdmap *newmap = NULL, *oldmap;
+	int err;
+	struct ceph_fsid fsid;
+	bool was_full;
+
+	dout("handle_map have %u\n", osdc->osdmap ? osdc->osdmap->epoch : 0);
+	p = msg->front.iov_base;
+	end = p + msg->front.iov_len;
+
+	/* verify fsid */
+	ceph_decode_need(&p, end, sizeof(fsid), bad);
+	ceph_decode_copy(&p, &fsid, sizeof(fsid));
+	if (ceph_check_fsid(osdc->client, &fsid) < 0)
+		return;
+
+	down_write(&osdc->map_sem);
+
+	was_full = ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL);
+
+	/* incremental maps */
+	ceph_decode_32_safe(&p, end, nr_maps, bad);
+	dout(" %d inc maps\n", nr_maps);
+	while (nr_maps > 0) {
+		ceph_decode_need(&p, end, 2*sizeof(u32), bad);
+		epoch = ceph_decode_32(&p);
+		maplen = ceph_decode_32(&p);
+		ceph_decode_need(&p, end, maplen, bad);
+		next = p + maplen;
+		if (osdc->osdmap && osdc->osdmap->epoch+1 == epoch) {
+			dout("applying incremental map %u len %d\n",
+			     epoch, maplen);
+			newmap = osdmap_apply_incremental(&p, next,
+							  osdc->osdmap,
+							  &osdc->client->msgr);
+			if (IS_ERR(newmap)) {
+				err = PTR_ERR(newmap);
+				goto bad;
+			}
+			BUG_ON(!newmap);
+			if (newmap != osdc->osdmap) {
+				ceph_osdmap_destroy(osdc->osdmap);
+				osdc->osdmap = newmap;
+			}
+			was_full = was_full ||
+				ceph_osdmap_flag(osdc->osdmap,
+						 CEPH_OSDMAP_FULL);
+			kick_requests(osdc, 0, was_full);
+		} else {
+			dout("ignoring incremental map %u len %d\n",
+			     epoch, maplen);
+		}
+		p = next;
+		nr_maps--;
+	}
+	if (newmap)
+		goto done;
+
+	/* full maps */
+	ceph_decode_32_safe(&p, end, nr_maps, bad);
+	dout(" %d full maps\n", nr_maps);
+	while (nr_maps) {
+		ceph_decode_need(&p, end, 2*sizeof(u32), bad);
+		epoch = ceph_decode_32(&p);
+		maplen = ceph_decode_32(&p);
+		ceph_decode_need(&p, end, maplen, bad);
+		if (nr_maps > 1) {
+			dout("skipping non-latest full map %u len %d\n",
+			     epoch, maplen);
+		} else if (osdc->osdmap && osdc->osdmap->epoch >= epoch) {
+			dout("skipping full map %u len %d, "
+			     "older than our %u\n", epoch, maplen,
+			     osdc->osdmap->epoch);
+		} else {
+			int skipped_map = 0;
+
+			dout("taking full map %u len %d\n", epoch, maplen);
+			newmap = ceph_osdmap_decode(&p, p+maplen);
+			if (IS_ERR(newmap)) {
+				err = PTR_ERR(newmap);
+				goto bad;
+			}
+			BUG_ON(!newmap);
+			oldmap = osdc->osdmap;
+			osdc->osdmap = newmap;
+			if (oldmap) {
+				if (oldmap->epoch + 1 < newmap->epoch)
+					skipped_map = 1;
+				ceph_osdmap_destroy(oldmap);
+			}
+			was_full = was_full ||
+				ceph_osdmap_flag(osdc->osdmap,
+						 CEPH_OSDMAP_FULL);
+			kick_requests(osdc, skipped_map, was_full);
+		}
+		p += maplen;
+		nr_maps--;
+	}
+
+	if (!osdc->osdmap)
+		goto bad;
+done:
+	downgrade_write(&osdc->map_sem);
+	ceph_monc_got_osdmap(&osdc->client->monc, osdc->osdmap->epoch);
+
+	/*
+	 * subscribe to subsequent osdmap updates if full to ensure
+	 * we find out when we are no longer full and stop returning
+	 * ENOSPC.
+	 */
+	if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL) ||
+		ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_PAUSERD) ||
+		ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_PAUSEWR))
+		ceph_monc_request_next_osdmap(&osdc->client->monc);
+
+	mutex_lock(&osdc->request_mutex);
+	__send_queued(osdc);
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+	wake_up_all(&osdc->client->auth_wq);
+	return;
+
+bad:
+	pr_err("osdc handle_map corrupt msg\n");
+	ceph_msg_dump(msg);
+	up_write(&osdc->map_sem);
+}
+
+/*
+ * 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 *),
+			   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 = 0;
+	event->data = data;
+	event->osdc = osdc;
+	INIT_LIST_HEAD(&event->osd_node);
+	RB_CLEAR_NODE(&event->node);
+	kref_init(&event->kref);   /* one ref for us */
+	kref_get(&event->kref);    /* one ref for the caller */
+
+	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);
+	dout("do_event_work completed %p\n", event);
+	ceph_osdc_put_event(event);
+	kfree(event_work);
+}
+
+
+/*
+ * Process osd watch notifications
+ */
+static 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) {
+		BUG_ON(event->one_shot);
+		get_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);
+		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->ver = ver;
+		event_work->notify_id = notify_id;
+		event_work->opcode = opcode;
+
+		queue_work(osdc->notify_wq, &event_work->work);
+	}
+
+	return;
+
+bad:
+	pr_err("osdc handle_watch_notify corrupt msg\n");
+}
+
+/*
+ * build new request AND message
+ *
+ */
+void ceph_osdc_build_request(struct ceph_osd_request *req, u64 off,
+				struct ceph_snap_context *snapc, u64 snap_id,
+				struct timespec *mtime)
+{
+	struct ceph_msg *msg = req->r_request;
+	void *p;
+	size_t msg_size;
+	int flags = req->r_flags;
+	u64 data_len;
+	unsigned int i;
+
+	req->r_snapid = snap_id;
+	req->r_snapc = ceph_get_snap_context(snapc);
+
+	/* encode request */
+	msg->hdr.version = cpu_to_le16(4);
+
+	p = msg->front.iov_base;
+	ceph_encode_32(&p, 1);   /* client_inc  is always 1 */
+	req->r_request_osdmap_epoch = p;
+	p += 4;
+	req->r_request_flags = p;
+	p += 4;
+	if (req->r_flags & CEPH_OSD_FLAG_WRITE)
+		ceph_encode_timespec(p, mtime);
+	p += sizeof(struct ceph_timespec);
+	req->r_request_reassert_version = p;
+	p += sizeof(struct ceph_eversion); /* will get filled in */
+
+	/* oloc */
+	ceph_encode_8(&p, 4);
+	ceph_encode_8(&p, 4);
+	ceph_encode_32(&p, 8 + 4 + 4);
+	req->r_request_pool = p;
+	p += 8;
+	ceph_encode_32(&p, -1);  /* preferred */
+	ceph_encode_32(&p, 0);   /* key len */
+
+	ceph_encode_8(&p, 1);
+	req->r_request_pgid = p;
+	p += 8 + 4;
+	ceph_encode_32(&p, -1);  /* preferred */
+
+	/* oid */
+	ceph_encode_32(&p, req->r_base_oid.name_len);
+	memcpy(p, req->r_base_oid.name, req->r_base_oid.name_len);
+	dout("oid '%.*s' len %d\n", req->r_base_oid.name_len,
+	     req->r_base_oid.name, req->r_base_oid.name_len);
+	p += req->r_base_oid.name_len;
+
+	/* ops--can imply data */
+	ceph_encode_16(&p, (u16)req->r_num_ops);
+	data_len = 0;
+	for (i = 0; i < req->r_num_ops; i++) {
+		data_len += osd_req_encode_op(req, p, i);
+		p += sizeof(struct ceph_osd_op);
+	}
+
+	/* snaps */
+	ceph_encode_64(&p, req->r_snapid);
+	ceph_encode_64(&p, req->r_snapc ? req->r_snapc->seq : 0);
+	ceph_encode_32(&p, req->r_snapc ? req->r_snapc->num_snaps : 0);
+	if (req->r_snapc) {
+		for (i = 0; i < snapc->num_snaps; i++) {
+			ceph_encode_64(&p, req->r_snapc->snaps[i]);
+		}
+	}
+
+	req->r_request_attempts = p;
+	p += 4;
+
+	/* data */
+	if (flags & CEPH_OSD_FLAG_WRITE) {
+		u16 data_off;
+
+		/*
+		 * The header "data_off" is a hint to the receiver
+		 * allowing it to align received data into its
+		 * buffers such that there's no need to re-copy
+		 * it before writing it to disk (direct I/O).
+		 */
+		data_off = (u16) (off & 0xffff);
+		req->r_request->hdr.data_off = cpu_to_le16(data_off);
+	}
+	req->r_request->hdr.data_len = cpu_to_le32(data_len);
+
+	BUG_ON(p > msg->front.iov_base + msg->front.iov_len);
+	msg_size = p - msg->front.iov_base;
+	msg->front.iov_len = msg_size;
+	msg->hdr.front_len = cpu_to_le32(msg_size);
+
+	dout("build_request msg_size was %d\n", (int)msg_size);
+}
+EXPORT_SYMBOL(ceph_osdc_build_request);
+
+/*
+ * Register request, send initial attempt.
+ */
+int ceph_osdc_start_request(struct ceph_osd_client *osdc,
+			    struct ceph_osd_request *req,
+			    bool nofail)
+{
+	int rc;
+
+	down_read(&osdc->map_sem);
+	mutex_lock(&osdc->request_mutex);
+
+	rc = __ceph_osdc_start_request(osdc, req, nofail);
+
+	mutex_unlock(&osdc->request_mutex);
+	up_read(&osdc->map_sem);
+
+	return rc;
+}
+EXPORT_SYMBOL(ceph_osdc_start_request);
+
+/*
+ * Unregister a registered request.  The request is not completed (i.e.
+ * no callbacks or wakeups) - higher layers are supposed to know what
+ * they are canceling.
+ */
+void ceph_osdc_cancel_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+
+	mutex_lock(&osdc->request_mutex);
+	if (req->r_linger)
+		__unregister_linger_request(osdc, req);
+	__unregister_request(osdc, req);
+	mutex_unlock(&osdc->request_mutex);
+
+	dout("%s %p tid %llu canceled\n", __func__, req, req->r_tid);
+}
+EXPORT_SYMBOL(ceph_osdc_cancel_request);
+
+/*
+ * wait for a request to complete
+ */
+int ceph_osdc_wait_request(struct ceph_osd_client *osdc,
+			   struct ceph_osd_request *req)
+{
+	int rc;
+
+	dout("%s %p tid %llu\n", __func__, req, req->r_tid);
+
+	rc = wait_for_completion_interruptible(&req->r_completion);
+	if (rc < 0) {
+		dout("%s %p tid %llu interrupted\n", __func__, req, req->r_tid);
+		ceph_osdc_cancel_request(req);
+		complete_request(req);
+		return rc;
+	}
+
+	dout("%s %p tid %llu result %d\n", __func__, req, req->r_tid,
+	     req->r_result);
+	return req->r_result;
+}
+EXPORT_SYMBOL(ceph_osdc_wait_request);
+
+/*
+ * sync - wait for all in-flight requests to flush.  avoid starvation.
+ */
+void ceph_osdc_sync(struct ceph_osd_client *osdc)
+{
+	struct ceph_osd_request *req;
+	u64 last_tid, next_tid = 0;
+
+	mutex_lock(&osdc->request_mutex);
+	last_tid = osdc->last_tid;
+	while (1) {
+		req = __lookup_request_ge(osdc, next_tid);
+		if (!req)
+			break;
+		if (req->r_tid > last_tid)
+			break;
+
+		next_tid = req->r_tid + 1;
+		if ((req->r_flags & CEPH_OSD_FLAG_WRITE) == 0)
+			continue;
+
+		ceph_osdc_get_request(req);
+		mutex_unlock(&osdc->request_mutex);
+		dout("sync waiting on tid %llu (last is %llu)\n",
+		     req->r_tid, last_tid);
+		wait_for_completion(&req->r_safe_completion);
+		mutex_lock(&osdc->request_mutex);
+		ceph_osdc_put_request(req);
+	}
+	mutex_unlock(&osdc->request_mutex);
+	dout("sync done (thru tid %llu)\n", last_tid);
+}
+EXPORT_SYMBOL(ceph_osdc_sync);
+
+/*
+ * Call all pending notify callbacks - for use after a watch is
+ * unregistered, to make sure no more callbacks for it will be invoked
+ */
+void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc)
+{
+	flush_workqueue(osdc->notify_wq);
+}
+EXPORT_SYMBOL(ceph_osdc_flush_notifies);
+
+
+/*
+ * init, shutdown
+ */
+int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
+{
+	int err;
+
+	dout("init\n");
+	osdc->client = client;
+	osdc->osdmap = NULL;
+	init_rwsem(&osdc->map_sem);
+	init_completion(&osdc->map_waiters);
+	osdc->last_requested_map = 0;
+	mutex_init(&osdc->request_mutex);
+	osdc->last_tid = 0;
+	osdc->osds = RB_ROOT;
+	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));
+
+	err = -ENOMEM;
+	osdc->req_mempool = mempool_create_kmalloc_pool(10,
+					sizeof(struct ceph_osd_request));
+	if (!osdc->req_mempool)
+		goto out;
+
+	err = ceph_msgpool_init(&osdc->msgpool_op, CEPH_MSG_OSD_OP,
+				OSD_OP_FRONT_LEN, 10, true,
+				"osd_op");
+	if (err < 0)
+		goto out_mempool;
+	err = ceph_msgpool_init(&osdc->msgpool_op_reply, CEPH_MSG_OSD_OPREPLY,
+				OSD_OPREPLY_FRONT_LEN, 10, true,
+				"osd_op_reply");
+	if (err < 0)
+		goto out_msgpool;
+
+	err = -ENOMEM;
+	osdc->notify_wq = create_singlethread_workqueue("ceph-watch-notify");
+	if (!osdc->notify_wq)
+		goto out_msgpool_reply;
+
+	return 0;
+
+out_msgpool_reply:
+	ceph_msgpool_destroy(&osdc->msgpool_op_reply);
+out_msgpool:
+	ceph_msgpool_destroy(&osdc->msgpool_op);
+out_mempool:
+	mempool_destroy(osdc->req_mempool);
+out:
+	return err;
+}
+
+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) {
+		ceph_osdmap_destroy(osdc->osdmap);
+		osdc->osdmap = NULL;
+	}
+	remove_all_osds(osdc);
+	mempool_destroy(osdc->req_mempool);
+	ceph_msgpool_destroy(&osdc->msgpool_op);
+	ceph_msgpool_destroy(&osdc->msgpool_op_reply);
+}
+
+/*
+ * Read some contiguous pages.  If we cross a stripe boundary, shorten
+ * *plen.  Return number of bytes read, or error.
+ */
+int ceph_osdc_readpages(struct ceph_osd_client *osdc,
+			struct ceph_vino vino, struct ceph_file_layout *layout,
+			u64 off, u64 *plen,
+			u32 truncate_seq, u64 truncate_size,
+			struct page **pages, int num_pages, int page_align)
+{
+	struct ceph_osd_request *req;
+	int rc = 0;
+
+	dout("readpages on ino %llx.%llx on %llu~%llu\n", vino.ino,
+	     vino.snap, off, *plen);
+	req = ceph_osdc_new_request(osdc, layout, vino, off, plen, 0, 1,
+				    CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
+				    NULL, truncate_seq, truncate_size,
+				    false);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	/* it may be a short read due to an object boundary */
+
+	osd_req_op_extent_osd_data_pages(req, 0,
+				pages, *plen, page_align, false, false);
+
+	dout("readpages  final extent is %llu~%llu (%llu bytes align %d)\n",
+	     off, *plen, *plen, page_align);
+
+	ceph_osdc_build_request(req, off, NULL, vino.snap, NULL);
+
+	rc = ceph_osdc_start_request(osdc, req, false);
+	if (!rc)
+		rc = ceph_osdc_wait_request(osdc, req);
+
+	ceph_osdc_put_request(req);
+	dout("readpages result %d\n", rc);
+	return rc;
+}
+EXPORT_SYMBOL(ceph_osdc_readpages);
+
+/*
+ * do a synchronous write on N pages
+ */
+int ceph_osdc_writepages(struct ceph_osd_client *osdc, struct ceph_vino vino,
+			 struct ceph_file_layout *layout,
+			 struct ceph_snap_context *snapc,
+			 u64 off, u64 len,
+			 u32 truncate_seq, u64 truncate_size,
+			 struct timespec *mtime,
+			 struct page **pages, int num_pages)
+{
+	struct ceph_osd_request *req;
+	int rc = 0;
+	int page_align = off & ~PAGE_MASK;
+
+	BUG_ON(vino.snap != CEPH_NOSNAP);	/* snapshots aren't writeable */
+	req = ceph_osdc_new_request(osdc, layout, vino, off, &len, 0, 1,
+				    CEPH_OSD_OP_WRITE,
+				    CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
+				    snapc, truncate_seq, truncate_size,
+				    true);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	/* it may be a short write due to an object boundary */
+	osd_req_op_extent_osd_data_pages(req, 0, pages, len, page_align,
+				false, false);
+	dout("writepages %llu~%llu (%llu bytes)\n", off, len, len);
+
+	ceph_osdc_build_request(req, off, snapc, CEPH_NOSNAP, mtime);
+
+	rc = ceph_osdc_start_request(osdc, req, true);
+	if (!rc)
+		rc = ceph_osdc_wait_request(osdc, req);
+
+	ceph_osdc_put_request(req);
+	if (rc == 0)
+		rc = len;
+	dout("writepages result %d\n", rc);
+	return rc;
+}
+EXPORT_SYMBOL(ceph_osdc_writepages);
+
+int ceph_osdc_setup(void)
+{
+	BUG_ON(ceph_osd_request_cache);
+	ceph_osd_request_cache = kmem_cache_create("ceph_osd_request",
+					sizeof (struct ceph_osd_request),
+					__alignof__(struct ceph_osd_request),
+					0, NULL);
+
+	return ceph_osd_request_cache ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(ceph_osdc_setup);
+
+void ceph_osdc_cleanup(void)
+{
+	BUG_ON(!ceph_osd_request_cache);
+	kmem_cache_destroy(ceph_osd_request_cache);
+	ceph_osd_request_cache = NULL;
+}
+EXPORT_SYMBOL(ceph_osdc_cleanup);
+
+/*
+ * handle incoming message
+ */
+static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	struct ceph_osd *osd = con->private;
+	struct ceph_osd_client *osdc;
+	int type = le16_to_cpu(msg->hdr.type);
+
+	if (!osd)
+		goto out;
+	osdc = osd->o_osdc;
+
+	switch (type) {
+	case CEPH_MSG_OSD_MAP:
+		ceph_osdc_handle_map(osdc, msg);
+		break;
+	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,
+		       ceph_msg_type_name(type));
+	}
+out:
+	ceph_msg_put(msg);
+}
+
+/*
+ * lookup and return message for incoming reply.  set up reply message
+ * pages.
+ */
+static struct ceph_msg *get_reply(struct ceph_connection *con,
+				  struct ceph_msg_header *hdr,
+				  int *skip)
+{
+	struct ceph_osd *osd = con->private;
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	struct ceph_msg *m;
+	struct ceph_osd_request *req;
+	int front_len = le32_to_cpu(hdr->front_len);
+	int data_len = le32_to_cpu(hdr->data_len);
+	u64 tid;
+
+	tid = le64_to_cpu(hdr->tid);
+	mutex_lock(&osdc->request_mutex);
+	req = __lookup_request(osdc, tid);
+	if (!req) {
+		*skip = 1;
+		m = NULL;
+		dout("get_reply unknown tid %llu from osd%d\n", tid,
+		     osd->o_osd);
+		goto out;
+	}
+
+	if (req->r_reply->con)
+		dout("%s revoking msg %p from old con %p\n", __func__,
+		     req->r_reply, req->r_reply->con);
+	ceph_msg_revoke_incoming(req->r_reply);
+
+	if (front_len > req->r_reply->front_alloc_len) {
+		pr_warn("get_reply front %d > preallocated %d (%u#%llu)\n",
+			front_len, req->r_reply->front_alloc_len,
+			(unsigned int)con->peer_name.type,
+			le64_to_cpu(con->peer_name.num));
+		m = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, front_len, GFP_NOFS,
+				 false);
+		if (!m)
+			goto out;
+		ceph_msg_put(req->r_reply);
+		req->r_reply = m;
+	}
+	m = ceph_msg_get(req->r_reply);
+
+	if (data_len > 0) {
+		struct ceph_osd_data *osd_data;
+
+		/*
+		 * XXX This is assuming there is only one op containing
+		 * XXX page data.  Probably OK for reads, but this
+		 * XXX ought to be done more generally.
+		 */
+		osd_data = osd_req_op_extent_osd_data(req, 0);
+		if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
+			if (osd_data->pages &&
+				unlikely(osd_data->length < data_len)) {
+
+				pr_warn("tid %lld reply has %d bytes we had only %llu bytes ready\n",
+					tid, data_len, osd_data->length);
+				*skip = 1;
+				ceph_msg_put(m);
+				m = NULL;
+				goto out;
+			}
+		}
+	}
+	*skip = 0;
+	dout("get_reply tid %lld %p\n", tid, m);
+
+out:
+	mutex_unlock(&osdc->request_mutex);
+	return m;
+
+}
+
+static struct ceph_msg *alloc_msg(struct ceph_connection *con,
+				  struct ceph_msg_header *hdr,
+				  int *skip)
+{
+	struct ceph_osd *osd = con->private;
+	int type = le16_to_cpu(hdr->type);
+	int front = le32_to_cpu(hdr->front_len);
+
+	*skip = 0;
+	switch (type) {
+	case CEPH_MSG_OSD_MAP:
+	case CEPH_MSG_WATCH_NOTIFY:
+		return ceph_msg_new(type, front, GFP_NOFS, false);
+	case CEPH_MSG_OSD_OPREPLY:
+		return get_reply(con, hdr, skip);
+	default:
+		pr_info("alloc_msg unexpected msg type %d from osd%d\n", type,
+			osd->o_osd);
+		*skip = 1;
+		return NULL;
+	}
+}
+
+/*
+ * Wrappers to refcount containing ceph_osd struct
+ */
+static struct ceph_connection *get_osd_con(struct ceph_connection *con)
+{
+	struct ceph_osd *osd = con->private;
+	if (get_osd(osd))
+		return con;
+	return NULL;
+}
+
+static void put_osd_con(struct ceph_connection *con)
+{
+	struct ceph_osd *osd = con->private;
+	put_osd(osd);
+}
+
+/*
+ * authentication
+ */
+/*
+ * Note: returned pointer is the address of a structure that's
+ * managed separately.  Caller must *not* attempt to free it.
+ */
+static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
+					int *proto, int force_new)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+	struct ceph_auth_handshake *auth = &o->o_auth;
+
+	if (force_new && auth->authorizer) {
+		ceph_auth_destroy_authorizer(ac, auth->authorizer);
+		auth->authorizer = NULL;
+	}
+	if (!auth->authorizer) {
+		int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_OSD,
+						      auth);
+		if (ret)
+			return ERR_PTR(ret);
+	} else {
+		int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_OSD,
+						     auth);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+	*proto = ac->protocol;
+
+	return auth;
+}
+
+
+static int verify_authorizer_reply(struct ceph_connection *con, int len)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+
+	return ceph_auth_verify_authorizer_reply(ac, o->o_auth.authorizer, len);
+}
+
+static int invalidate_authorizer(struct ceph_connection *con)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+
+	ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_OSD);
+	return ceph_monc_validate_auth(&osdc->client->monc);
+}
+
+static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_auth_handshake *auth = &o->o_auth;
+	return ceph_auth_sign_message(auth, msg);
+}
+
+static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_auth_handshake *auth = &o->o_auth;
+	return ceph_auth_check_message_signature(auth, msg);
+}
+
+static const struct ceph_connection_operations osd_con_ops = {
+	.get = get_osd_con,
+	.put = put_osd_con,
+	.dispatch = dispatch,
+	.get_authorizer = get_authorizer,
+	.verify_authorizer_reply = verify_authorizer_reply,
+	.invalidate_authorizer = invalidate_authorizer,
+	.alloc_msg = alloc_msg,
+	.sign_message = sign_message,
+	.check_message_signature = check_message_signature,
+	.fault = osd_reset,
+};