X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Flov%2Flov_object.c;h=afe3b9f532070058b879dcf4cb03486ec53fed25;hb=49b17944e1a61f88bddb5595bb053a555c8c08da;hp=658b34d7dba03d68f7709e11ed42216670e5966e;hpb=f95393b0d0a59cf3dc2f29cffc35dcc4cc9d7728;p=fs%2Flustre-release.git

diff --git a/lustre/lov/lov_object.c b/lustre/lov/lov_object.c
index 658b34d..afe3b9f 100644
--- a/lustre/lov/lov_object.c
+++ b/lustre/lov/lov_object.c
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -28,6 +26,8 @@
 /*
  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -36,6 +36,7 @@
  * Implementation of cl_object for LOV layer.
  *
  *   Author: Nikita Danilov <nikita.danilov@sun.com>
+ *   Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
  */
 
 #define DEBUG_SUBSYSTEM S_LOV
@@ -57,7 +58,7 @@ struct lov_layout_operations {
                         struct lov_object *lov,
                         const struct cl_object_conf *conf,
                         union lov_layout_state *state);
-        void (*llo_delete)(const struct lu_env *env, struct lov_object *lov,
+	int (*llo_delete)(const struct lu_env *env, struct lov_object *lov,
                            union lov_layout_state *state);
         void (*llo_fini)(const struct lu_env *env, struct lov_object *lov,
                          union lov_layout_state *state);
@@ -65,10 +66,8 @@ struct lov_layout_operations {
                             union lov_layout_state *state);
         int  (*llo_print)(const struct lu_env *env, void *cookie,
                           lu_printer_t p, const struct lu_object *o);
-        struct cl_page *(*llo_page_init)(const struct lu_env *env,
-                                         struct cl_object *obj,
-                                         struct cl_page *page,
-                                         cfs_page_t *vmpage);
+        int  (*llo_page_init)(const struct lu_env *env, struct cl_object *obj,
+			      struct cl_page *page, pgoff_t index);
         int  (*llo_lock_init)(const struct lu_env *env,
                               struct cl_object *obj, struct cl_lock *lock,
                               const struct cl_io *io);
@@ -76,8 +75,35 @@ struct lov_layout_operations {
                             struct cl_object *obj, struct cl_io *io);
         int  (*llo_getattr)(const struct lu_env *env, struct cl_object *obj,
                             struct cl_attr *attr);
+	int  (*llo_find_cbdata)(const struct lu_env *env, struct cl_object *obj,
+				ldlm_iterator_t iter, void *data);
 };
 
+static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov);
+
+struct lov_stripe_md *lov_lsm_get(struct cl_object *clobj)
+{
+	struct lu_object *luobj;
+	struct lov_stripe_md *lsm = NULL;
+
+	if (clobj == NULL)
+		return NULL;
+
+	luobj = lu_object_locate(&cl_object_header(clobj)->coh_lu,
+				 &lov_device_type);
+	if (luobj != NULL)
+		lsm = lov_lsm_addref(lu2lov(luobj));
+	return lsm;
+}
+EXPORT_SYMBOL(lov_lsm_get);
+
+void lov_lsm_put(struct cl_object *unused, struct lov_stripe_md *lsm)
+{
+	if (lsm != NULL)
+		lov_free_memmd(&lsm);
+}
+EXPORT_SYMBOL(lov_lsm_put);
+
 /*****************************************************************************
  *
  * Lov object layout operations.
@@ -105,7 +131,6 @@ static void lov_install_raid0(const struct lu_env *env,
                               struct lov_object *lov,
                               union  lov_layout_state *state)
 {
-        lov->u = *state;
 }
 
 static struct cl_object *lov_sub_find(const struct lu_env *env,
@@ -122,45 +147,90 @@ static struct cl_object *lov_sub_find(const struct lu_env *env,
 }
 
 static int lov_init_sub(const struct lu_env *env, struct lov_object *lov,
-                        struct cl_object *stripe,
-                        struct lov_layout_raid0 *r0, int idx)
+			struct cl_object *stripe, struct lov_layout_raid0 *r0,
+			int idx)
 {
-        struct cl_object_header *hdr;
-        struct cl_object_header *subhdr;
-        struct cl_object_header *parent;
-        struct lov_oinfo        *oinfo;
-        int result;
+	struct cl_object_header *hdr;
+	struct cl_object_header *subhdr;
+	struct cl_object_header *parent;
+	struct lov_oinfo        *oinfo;
+	int result;
+
+	if (OBD_FAIL_CHECK(OBD_FAIL_LOV_INIT)) {
+		/* For sanity:test_206.
+		 * Do not leave the object in cache to avoid accessing
+		 * freed memory. This is because osc_object is referring to
+		 * lov_oinfo of lsm_stripe_data which will be freed due to
+		 * this failure. */
+		cl_object_kill(env, stripe);
+		cl_object_put(env, stripe);
+		return -EIO;
+	}
+
+	hdr    = cl_object_header(lov2cl(lov));
+	subhdr = cl_object_header(stripe);
+
+	oinfo = lov->lo_lsm->lsm_oinfo[idx];
+	CDEBUG(D_INODE, DFID"@%p[%d] -> "DFID"@%p: ostid: "DOSTID
+	       " idx: %d gen: %d\n",
+	       PFID(&subhdr->coh_lu.loh_fid), subhdr, idx,
+	       PFID(&hdr->coh_lu.loh_fid), hdr, POSTID(&oinfo->loi_oi),
+	       oinfo->loi_ost_idx, oinfo->loi_ost_gen);
+
+	/* reuse ->coh_attr_guard to protect coh_parent change */
+	spin_lock(&subhdr->coh_attr_guard);
+	parent = subhdr->coh_parent;
+	if (parent == NULL) {
+		subhdr->coh_parent = hdr;
+		spin_unlock(&subhdr->coh_attr_guard);
+		subhdr->coh_nesting = hdr->coh_nesting + 1;
+		lu_object_ref_add(&stripe->co_lu, "lov-parent", lov);
+		r0->lo_sub[idx] = cl2lovsub(stripe);
+		r0->lo_sub[idx]->lso_super = lov;
+		r0->lo_sub[idx]->lso_index = idx;
+		result = 0;
+	} else {
+		struct lu_object  *old_obj;
+		struct lov_object *old_lov;
+		unsigned int mask = D_INODE;
+
+		spin_unlock(&subhdr->coh_attr_guard);
+		old_obj = lu_object_locate(&parent->coh_lu, &lov_device_type);
+		LASSERT(old_obj != NULL);
+		old_lov = cl2lov(lu2cl(old_obj));
+		if (old_lov->lo_layout_invalid) {
+			/* the object's layout has already changed but isn't
+			 * refreshed */
+			lu_object_unhash(env, &stripe->co_lu);
+			result = -EAGAIN;
+		} else {
+			mask = D_ERROR;
+			result = -EIO;
+		}
+
+		LU_OBJECT_DEBUG(mask, env, &stripe->co_lu,
+				"stripe %d is already owned.\n", idx);
+		LU_OBJECT_DEBUG(mask, env, old_obj, "owned.\n");
+		LU_OBJECT_HEADER(mask, env, lov2lu(lov), "try to own.\n");
+		cl_object_put(env, stripe);
+	}
+	return result;
+}
 
-        hdr    = cl_object_header(lov2cl(lov));
-        subhdr = cl_object_header(stripe);
-        parent = subhdr->coh_parent;
-
-        oinfo = r0->lo_lsm->lsm_oinfo[idx];
-        CDEBUG(D_INODE, DFID"@%p[%d] -> "DFID"@%p: id: "LPU64" seq: "LPU64
-               " idx: %d gen: %d\n",
-               PFID(&subhdr->coh_lu.loh_fid), subhdr, idx,
-               PFID(&hdr->coh_lu.loh_fid), hdr,
-               oinfo->loi_id, oinfo->loi_seq,
-               oinfo->loi_ost_idx, oinfo->loi_ost_gen);
-
-        if (parent == NULL) {
-                subhdr->coh_parent = hdr;
-                subhdr->coh_nesting = hdr->coh_nesting + 1;
-                lu_object_ref_add(&stripe->co_lu, "lov-parent", lov);
-                r0->lo_sub[idx] = cl2lovsub(stripe);
-                r0->lo_sub[idx]->lso_super = lov;
-                r0->lo_sub[idx]->lso_index = idx;
-                result = 0;
-        } else {
-                CERROR("Stripe is already owned by other file (%i).\n", idx);
-                LU_OBJECT_DEBUG(D_ERROR, env, &stripe->co_lu, "\n");
-                LU_OBJECT_DEBUG(D_ERROR, env, lu_object_top(&parent->coh_lu),
-                                "old\n");
-                LU_OBJECT_HEADER(D_ERROR, env, lov2lu(lov), "new\n");
-                cl_object_put(env, stripe);
-                result = -EIO;
-        }
-        return result;
+static int lov_page_slice_fixup(struct lov_object *lov,
+				struct cl_object *stripe)
+{
+	struct cl_object_header *hdr = cl_object_header(&lov->lo_cl);
+	struct cl_object *o;
+
+	if (stripe == NULL)
+		return hdr->coh_page_bufsize - lov->lo_cl.co_slice_off -
+		       cfs_size_round(sizeof(struct lov_page));
+
+	cl_object_for_each(o, stripe)
+		o->co_slice_off += hdr->coh_page_bufsize;
+
+	return cl_object_header(stripe)->coh_page_bufsize;
 }
 
 static int lov_init_raid0(const struct lu_env *env,
@@ -179,15 +249,27 @@ static int lov_init_raid0(const struct lu_env *env,
         struct lov_layout_raid0 *r0      = &state->raid0;
 
         ENTRY;
-        r0->lo_nr  = conf->u.coc_md->lsm->lsm_stripe_count;
-        r0->lo_lsm = conf->u.coc_md->lsm;
-        LASSERT(r0->lo_nr <= lov_targets_nr(dev));
 
-        OBD_ALLOC(r0->lo_sub, r0->lo_nr * sizeof r0->lo_sub[0]);
-        if (r0->lo_sub != NULL) {
-                result = 0;
-                subconf->coc_inode = conf->coc_inode;
-                cfs_spin_lock_init(&r0->lo_sub_lock);
+	if (lsm->lsm_magic != LOV_MAGIC_V1 && lsm->lsm_magic != LOV_MAGIC_V3) {
+		dump_lsm(D_ERROR, lsm);
+		LASSERTF(0, "magic mismatch, expected %d/%d, actual %d.\n",
+			 LOV_MAGIC_V1, LOV_MAGIC_V3, lsm->lsm_magic);
+	}
+
+	LASSERT(lov->lo_lsm == NULL);
+	lov->lo_lsm = lsm_addref(lsm);
+	r0->lo_nr  = lsm->lsm_stripe_count;
+	LASSERT(r0->lo_nr <= lov_targets_nr(dev));
+
+	lov->lo_layout_invalid = true;
+
+	OBD_ALLOC_LARGE(r0->lo_sub, r0->lo_nr * sizeof r0->lo_sub[0]);
+	if (r0->lo_sub != NULL) {
+		int psz = 0;
+
+		result = 0;
+		subconf->coc_inode = conf->coc_inode;
+		spin_lock_init(&r0->lo_sub_lock);
                 /*
                  * Create stripe cl_objects.
                  */
@@ -196,41 +278,115 @@ static int lov_init_raid0(const struct lu_env *env,
                         struct lov_oinfo *oinfo = lsm->lsm_oinfo[i];
                         int ost_idx = oinfo->loi_ost_idx;
 
-                        fid_ostid_unpack(ofid, &oinfo->loi_oi,
-                                         oinfo->loi_ost_idx);
-                        subdev = lovsub2cl_dev(dev->ld_target[ost_idx]);
-                        subconf->u.coc_oinfo = oinfo;
-                        LASSERTF(subdev != NULL, "not init ost %d\n", ost_idx);
-                        stripe = lov_sub_find(env, subdev, ofid, subconf);
-                        if (!IS_ERR(stripe))
-                                result = lov_init_sub(env, lov, stripe, r0, i);
-                        else
-                                result = PTR_ERR(stripe);
+			if (lov_oinfo_is_dummy(oinfo))
+				continue;
+
+			result = ostid_to_fid(ofid, &oinfo->loi_oi,
+					      oinfo->loi_ost_idx);
+			if (result != 0)
+				GOTO(out, result);
+
+			subdev = lovsub2cl_dev(dev->ld_target[ost_idx]);
+			subconf->u.coc_oinfo = oinfo;
+			LASSERTF(subdev != NULL, "not init ost %d\n", ost_idx);
+			/* In the function below, .hs_keycmp resolves to
+			 * lu_obj_hop_keycmp() */
+			/* coverity[overrun-buffer-val] */
+			stripe = lov_sub_find(env, subdev, ofid, subconf);
+			if (!IS_ERR(stripe)) {
+				result = lov_init_sub(env, lov, stripe, r0, i);
+				if (result == -EAGAIN) { /* try again */
+					--i;
+					result = 0;
+					continue;
+				}
+			} else {
+				result = PTR_ERR(stripe);
+			}
+
+			if (result == 0) {
+				int sz = lov_page_slice_fixup(lov, stripe);
+				LASSERT(ergo(psz > 0, psz == sz));
+				psz = sz;
+			}
                 }
-        } else
-                result = -ENOMEM;
-        RETURN(result);
+		if (result == 0)
+			cl_object_header(&lov->lo_cl)->coh_page_bufsize += psz;
+	} else
+		result = -ENOMEM;
+out:
+	RETURN(result);
+}
+
+static int lov_init_released(const struct lu_env *env,
+			struct lov_device *dev, struct lov_object *lov,
+			const struct cl_object_conf *conf,
+			union  lov_layout_state *state)
+{
+	struct lov_stripe_md *lsm = conf->u.coc_md->lsm;
+
+	LASSERT(lsm != NULL);
+	LASSERT(lsm_is_released(lsm));
+	LASSERT(lov->lo_lsm == NULL);
+
+	lov->lo_lsm = lsm_addref(lsm);
+	return 0;
+}
+
+static struct cl_object *lov_find_subobj(const struct lu_env *env,
+					 struct lov_object *lov,
+					 struct lov_stripe_md *lsm,
+					 int stripe_idx)
+{
+	struct lov_device	*dev = lu2lov_dev(lov2lu(lov)->lo_dev);
+	struct lov_oinfo	*oinfo = lsm->lsm_oinfo[stripe_idx];
+	struct lov_thread_info  *lti = lov_env_info(env);
+	struct lu_fid		*ofid = &lti->lti_fid;
+	struct cl_device	*subdev;
+	int			ost_idx;
+	int			rc;
+	struct cl_object	*result;
+
+	if (lov->lo_type != LLT_RAID0)
+		GOTO(out, result = NULL);
+
+	ost_idx = oinfo->loi_ost_idx;
+	rc = ostid_to_fid(ofid, &oinfo->loi_oi, ost_idx);
+	if (rc != 0)
+		GOTO(out, result = NULL);
+
+	subdev = lovsub2cl_dev(dev->ld_target[ost_idx]);
+	result = lov_sub_find(env, subdev, ofid, NULL);
+out:
+	if (result == NULL)
+		result = ERR_PTR(-EINVAL);
+	return result;
 }
 
-static void lov_delete_empty(const struct lu_env *env, struct lov_object *lov,
-                             union lov_layout_state *state)
+static int lov_delete_empty(const struct lu_env *env, struct lov_object *lov,
+			    union lov_layout_state *state)
 {
-        LASSERT(lov->lo_type == LLT_EMPTY);
+	LASSERT(lov->lo_type == LLT_EMPTY || lov->lo_type == LLT_RELEASED);
+
+	lov_layout_wait(env, lov);
+	return 0;
 }
 
 static void lov_subobject_kill(const struct lu_env *env, struct lov_object *lov,
-                               struct lovsub_object *los, int idx)
+			       struct lovsub_object *los, int idx)
 {
-        struct cl_object        *sub;
-        struct lov_layout_raid0 *r0;
-        struct lu_site          *site;
-        cfs_waitlink_t          *waiter;
+	struct cl_object        *sub;
+	struct lov_layout_raid0 *r0;
+	struct lu_site          *site;
+	struct lu_site_bkt_data *bkt;
+	wait_queue_t          *waiter;
 
         r0  = &lov->u.raid0;
         LASSERT(r0->lo_sub[idx] == los);
 
         sub  = lovsub2cl(los);
         site = sub->co_lu.lo_dev->ld_site;
+        bkt  = lu_site_bkt_from_fid(site, &sub->co_lu.lo_header->loh_fid);
 
         cl_object_kill(env, sub);
         /* release a reference to the sub-object and ... */
@@ -239,96 +395,135 @@ static void lov_subobject_kill(const struct lu_env *env, struct lov_object *lov,
 
         /* ... wait until it is actually destroyed---sub-object clears its
          * ->lo_sub[] slot in lovsub_object_fini() */
-        if (r0->lo_sub[idx] == los) {
-                waiter = &lov_env_info(env)->lti_waiter;
-                cfs_waitlink_init(waiter);
-                cfs_waitq_add(&site->ls_marche_funebre, waiter);
-                cfs_set_current_state(CFS_TASK_UNINT);
-                while (1) {
-                        /* this wait-queue is signaled at the end of
-                         * lu_object_free(). */
-                        cfs_set_current_state(CFS_TASK_UNINT);
-                        cfs_spin_lock(&r0->lo_sub_lock);
-                        if (r0->lo_sub[idx] == los) {
-                                cfs_spin_unlock(&r0->lo_sub_lock);
-                                cfs_waitq_wait(waiter, CFS_TASK_UNINT);
-                        } else {
-                                cfs_spin_unlock(&r0->lo_sub_lock);
-                                cfs_set_current_state(CFS_TASK_RUNNING);
-                                break;
-                        }
-                }
-                cfs_waitq_del(&site->ls_marche_funebre, waiter);
-        }
-        LASSERT(r0->lo_sub[idx] == NULL);
+	if (r0->lo_sub[idx] == los) {
+		waiter = &lov_env_info(env)->lti_waiter;
+		init_waitqueue_entry_current(waiter);
+		add_wait_queue(&bkt->lsb_marche_funebre, waiter);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		while (1) {
+			/* this wait-queue is signaled at the end of
+			 * lu_object_free(). */
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			spin_lock(&r0->lo_sub_lock);
+			if (r0->lo_sub[idx] == los) {
+				spin_unlock(&r0->lo_sub_lock);
+				waitq_wait(waiter, TASK_UNINTERRUPTIBLE);
+			} else {
+				spin_unlock(&r0->lo_sub_lock);
+				set_current_state(TASK_RUNNING);
+				break;
+			}
+		}
+		remove_wait_queue(&bkt->lsb_marche_funebre, waiter);
+	}
+	LASSERT(r0->lo_sub[idx] == NULL);
 }
 
-static void lov_delete_raid0(const struct lu_env *env, struct lov_object *lov,
-                             union lov_layout_state *state)
+static int lov_delete_raid0(const struct lu_env *env, struct lov_object *lov,
+			    union lov_layout_state *state)
 {
-        struct lov_layout_raid0 *r0 = &state->raid0;
-        int                      i;
+	struct lov_layout_raid0 *r0 = &state->raid0;
+	struct lov_stripe_md    *lsm = lov->lo_lsm;
+	int i;
 
-        ENTRY;
+	ENTRY;
+
+	dump_lsm(D_INODE, lsm);
+
+	lov_layout_wait(env, lov);
         if (r0->lo_sub != NULL) {
                 for (i = 0; i < r0->lo_nr; ++i) {
                         struct lovsub_object *los = r0->lo_sub[i];
 
-                        if (los != NULL)
+                        if (los != NULL) {
+				cl_object_prune(env, &los->lso_cl);
                                 /*
                                  * If top-level object is to be evicted from
                                  * the cache, so are its sub-objects.
                                  */
                                 lov_subobject_kill(env, lov, los, i);
-                }
-        }
-        EXIT;
+			}
+		}
+	}
+	RETURN(0);
 }
 
 static void lov_fini_empty(const struct lu_env *env, struct lov_object *lov,
                            union lov_layout_state *state)
 {
-        LASSERT(lov->lo_type == LLT_EMPTY);
+	LASSERT(lov->lo_type == LLT_EMPTY || lov->lo_type == LLT_RELEASED);
 }
 
 static void lov_fini_raid0(const struct lu_env *env, struct lov_object *lov,
                            union lov_layout_state *state)
 {
-        struct lov_layout_raid0 *r0 = &state->raid0;
+	struct lov_layout_raid0 *r0 = &state->raid0;
+	ENTRY;
 
-        ENTRY;
-        if (r0->lo_sub != NULL) {
-                OBD_FREE(r0->lo_sub, r0->lo_nr * sizeof r0->lo_sub[0]);
-                r0->lo_sub = NULL;
-        }
-        EXIT;
+	if (r0->lo_sub != NULL) {
+		OBD_FREE_LARGE(r0->lo_sub, r0->lo_nr * sizeof r0->lo_sub[0]);
+		r0->lo_sub = NULL;
+	}
+
+	dump_lsm(D_INODE, lov->lo_lsm);
+	lov_free_memmd(&lov->lo_lsm);
+
+	EXIT;
+}
+
+static void lov_fini_released(const struct lu_env *env, struct lov_object *lov,
+				union lov_layout_state *state)
+{
+	ENTRY;
+	dump_lsm(D_INODE, lov->lo_lsm);
+	lov_free_memmd(&lov->lo_lsm);
+	EXIT;
 }
 
 static int lov_print_empty(const struct lu_env *env, void *cookie,
                            lu_printer_t p, const struct lu_object *o)
 {
-        (*p)(env, cookie, "empty\n");
+        (*p)(env, cookie, "empty %d\n", lu2lov(o)->lo_layout_invalid);
         return 0;
 }
 
 static int lov_print_raid0(const struct lu_env *env, void *cookie,
-                           lu_printer_t p, const struct lu_object *o)
+			   lu_printer_t p, const struct lu_object *o)
 {
-        struct lov_object       *lov = lu2lov(o);
-        struct lov_layout_raid0 *r0  = lov_r0(lov);
-        int i;
-
-        (*p)(env, cookie, "stripes: %d:\n", r0->lo_nr);
-        for (i = 0; i < r0->lo_nr; ++i) {
-                struct lu_object *sub;
+	struct lov_object	*lov = lu2lov(o);
+	struct lov_layout_raid0	*r0  = lov_r0(lov);
+	struct lov_stripe_md	*lsm = lov->lo_lsm;
+	int			 i;
+
+	(*p)(env, cookie, "stripes: %d, %s, lsm{%p 0x%08X %d %u %u}:\n",
+		r0->lo_nr, lov->lo_layout_invalid ? "invalid" : "valid", lsm,
+		lsm->lsm_magic, atomic_read(&lsm->lsm_refc),
+		lsm->lsm_stripe_count, lsm->lsm_layout_gen);
+	for (i = 0; i < r0->lo_nr; ++i) {
+		struct lu_object *sub;
+
+		if (r0->lo_sub[i] != NULL) {
+			sub = lovsub2lu(r0->lo_sub[i]);
+			lu_object_print(env, cookie, p, sub);
+		} else {
+			(*p)(env, cookie, "sub %d absent\n", i);
+		}
+	}
+	return 0;
+}
 
-                if (r0->lo_sub[i] != NULL) {
-                        sub = lovsub2lu(r0->lo_sub[i]);
-                        lu_object_print(env, cookie, p, sub);
-                } else
-                        (*p)(env, cookie, "sub %d absent\n", i);
-        }
-        return 0;
+static int lov_print_released(const struct lu_env *env, void *cookie,
+				lu_printer_t p, const struct lu_object *o)
+{
+	struct lov_object	*lov = lu2lov(o);
+	struct lov_stripe_md	*lsm = lov->lo_lsm;
+
+	(*p)(env, cookie,
+		"released: %s, lsm{%p 0x%08X %d %u %u}:\n",
+		lov->lo_layout_invalid ? "invalid" : "valid", lsm,
+		lsm->lsm_magic, atomic_read(&lsm->lsm_refc),
+		lsm->lsm_stripe_count, lsm->lsm_layout_gen);
+	return 0;
 }
 
 /**
@@ -348,46 +543,99 @@ static int lov_attr_get_empty(const struct lu_env *env, struct cl_object *obj,
 static int lov_attr_get_raid0(const struct lu_env *env, struct cl_object *obj,
                               struct cl_attr *attr)
 {
-        struct lov_object       *lov = cl2lov(obj);
-        struct lov_layout_raid0 *r0 = lov_r0(lov);
-        struct lov_stripe_md    *lsm = lov->u.raid0.lo_lsm;
-        struct ost_lvb          *lvb = &lov_env_info(env)->lti_lvb;
-        __u64                    kms;
-        int                      result = 0;
+	struct lov_object	*lov = cl2lov(obj);
+	struct lov_layout_raid0 *r0 = lov_r0(lov);
+	struct cl_attr		*lov_attr = &r0->lo_attr;
+	int			 result = 0;
 
         ENTRY;
-        if (!r0->lo_attr_valid) {
-                /*
-                 * Fill LVB with attributes already initialized by the upper
-                 * layer.
-                 */
-                cl_attr2lvb(lvb, attr);
-                kms = attr->cat_kms;
 
-                /*
-                 * XXX that should be replaced with a loop over sub-objects,
-                 * doing cl_object_attr_get() on them. But for now, let's
-                 * reuse old lov code.
-                 */
+	/* this is called w/o holding type guard mutex, so it must be inside
+	 * an on going IO otherwise lsm may be replaced.
+	 * LU-2117: it turns out there exists one exception. For mmaped files,
+	 * the lock of those files may be requested in the other file's IO
+	 * context, and this function is called in ccc_lock_state(), it will
+	 * hit this assertion.
+	 * Anyway, it's still okay to call attr_get w/o type guard as layout
+	 * can't go if locks exist. */
+	/* LASSERT(atomic_read(&lsm->lsm_refc) > 1); */
+
+	if (!r0->lo_attr_valid) {
+		struct lov_stripe_md    *lsm = lov->lo_lsm;
+		struct ost_lvb          *lvb = &lov_env_info(env)->lti_lvb;
+		__u64                    kms = 0;
+
+		memset(lvb, 0, sizeof(*lvb));
+		/* XXX: timestamps can be negative by sanity:test_39m,
+		 * how can it be? */
+		lvb->lvb_atime = LLONG_MIN;
+		lvb->lvb_ctime = LLONG_MIN;
+		lvb->lvb_mtime = LLONG_MIN;
+
+		/*
+		 * XXX that should be replaced with a loop over sub-objects,
+		 * doing cl_object_attr_get() on them. But for now, let's
+		 * reuse old lov code.
+		 */
+
+		/*
+		 * XXX take lsm spin-lock to keep lov_merge_lvb_kms()
+		 * happy. It's not needed, because new code uses
+		 * ->coh_attr_guard spin-lock to protect consistency of
+		 * sub-object attributes.
+		 */
+		lov_stripe_lock(lsm);
+		result = lov_merge_lvb_kms(lsm, lvb, &kms);
+		lov_stripe_unlock(lsm);
+		if (result == 0) {
+			cl_lvb2attr(lov_attr, lvb);
+			lov_attr->cat_kms = kms;
+			r0->lo_attr_valid = 1;
+		}
+	}
+	if (result == 0) { /* merge results */
+		attr->cat_blocks = lov_attr->cat_blocks;
+		attr->cat_size = lov_attr->cat_size;
+		attr->cat_kms = lov_attr->cat_kms;
+		if (attr->cat_atime < lov_attr->cat_atime)
+			attr->cat_atime = lov_attr->cat_atime;
+		if (attr->cat_ctime < lov_attr->cat_ctime)
+			attr->cat_ctime = lov_attr->cat_ctime;
+		if (attr->cat_mtime < lov_attr->cat_mtime)
+			attr->cat_mtime = lov_attr->cat_mtime;
+	}
+	RETURN(result);
+}
 
-                /*
-                 * XXX take lsm spin-lock to keep lov_merge_lvb_kms()
-                 * happy. It's not needed, because new code uses
-                 * ->coh_attr_guard spin-lock to protect consistency of
-                 * sub-object attributes.
-                 */
-                lov_stripe_lock(lsm);
-                result = lov_merge_lvb_kms(lsm, lvb, &kms);
-                lov_stripe_unlock(lsm);
-                if (result == 0) {
-                        cl_lvb2attr(attr, lvb);
-                        attr->cat_kms = kms;
-                        r0->lo_attr_valid = 1;
-                        r0->lo_attr = *attr;
-                }
-        } else
-                *attr = r0->lo_attr;
-        RETURN(result);
+static int lov_find_cbdata_empty(const struct lu_env *env,
+				 struct cl_object *obj, ldlm_iterator_t iter,
+				 void *data)
+{
+	return 0;
+}
+
+static int lov_find_cbdata_raid0(const struct lu_env *env,
+				 struct cl_object *obj, ldlm_iterator_t iter,
+				 void *data)
+{
+	struct lov_object	*lov = cl2lov(obj);
+	struct lov_layout_raid0	*r0 = lov_r0(lov);
+	struct cl_object	*subobj;
+	int			i;
+	int			rc = 0;
+
+	for (i = 0; i < r0->lo_nr; ++i) {
+		if (r0->lo_sub[i] == NULL)
+			continue;
+
+		subobj = lovsub2cl(r0->lo_sub[i]);
+
+		rc = cl_object_find_cbdata(env, subobj, iter, data);
+		if (rc != 0)
+			break;
+	}
+
+	return rc;
 }
 
 const static struct lov_layout_operations lov_dispatch[] = {
@@ -398,9 +646,10 @@ const static struct lov_layout_operations lov_dispatch[] = {
                 .llo_install   = lov_install_empty,
                 .llo_print     = lov_print_empty,
                 .llo_page_init = lov_page_init_empty,
-                .llo_lock_init = NULL,
+                .llo_lock_init = lov_lock_init_empty,
                 .llo_io_init   = lov_io_init_empty,
-                .llo_getattr   = lov_attr_get_empty
+		.llo_getattr   = lov_attr_get_empty,
+		.llo_find_cbdata = lov_find_cbdata_empty
         },
         [LLT_RAID0] = {
                 .llo_init      = lov_init_raid0,
@@ -411,11 +660,23 @@ const static struct lov_layout_operations lov_dispatch[] = {
                 .llo_page_init = lov_page_init_raid0,
                 .llo_lock_init = lov_lock_init_raid0,
                 .llo_io_init   = lov_io_init_raid0,
-                .llo_getattr   = lov_attr_get_raid0
+		.llo_getattr   = lov_attr_get_raid0,
+		.llo_find_cbdata = lov_find_cbdata_raid0
+	},
+        [LLT_RELEASED] = {
+                .llo_init      = lov_init_released,
+                .llo_delete    = lov_delete_empty,
+                .llo_fini      = lov_fini_released,
+                .llo_install   = lov_install_empty,
+                .llo_print     = lov_print_released,
+                .llo_page_init = lov_page_init_empty,
+                .llo_lock_init = lov_lock_init_empty,
+                .llo_io_init   = lov_io_init_released,
+		.llo_getattr   = lov_attr_get_empty,
+		.llo_find_cbdata = lov_find_cbdata_empty
         }
 };
 
-
 /**
  * Performs a double-dispatch based on the layout type of an object.
  */
@@ -429,18 +690,41 @@ const static struct lov_layout_operations lov_dispatch[] = {
         lov_dispatch[__llt].op(__VA_ARGS__);                            \
 })
 
+/**
+ * Return lov_layout_type associated with a given lsm
+ */
+static enum lov_layout_type lov_type(struct lov_stripe_md *lsm)
+{
+	if (lsm == NULL)
+		return LLT_EMPTY;
+	if (lsm_is_released(lsm))
+		return LLT_RELEASED;
+	return LLT_RAID0;
+}
+
+static inline void lov_conf_freeze(struct lov_object *lov)
+{
+	if (lov->lo_owner != current)
+		down_read(&lov->lo_type_guard);
+}
+
+static inline void lov_conf_thaw(struct lov_object *lov)
+{
+	if (lov->lo_owner != current)
+		up_read(&lov->lo_type_guard);
+}
+
 #define LOV_2DISPATCH_MAYLOCK(obj, op, lock, ...)                       \
 ({                                                                      \
         struct lov_object                      *__obj = (obj);          \
         int                                     __lock = !!(lock);      \
         typeof(lov_dispatch[0].op(__VA_ARGS__)) __result;               \
                                                                         \
-        __lock &= __obj->lo_owner != cfs_current();                     \
         if (__lock)                                                     \
-                cfs_down_read(&__obj->lo_type_guard);                   \
+                lov_conf_freeze(__obj);					\
         __result = LOV_2DISPATCH_NOLOCK(obj, op, __VA_ARGS__);          \
         if (__lock)                                                     \
-                cfs_up_read(&__obj->lo_type_guard);                     \
+                lov_conf_thaw(__obj);					\
         __result;                                                       \
 })
 
@@ -455,58 +739,110 @@ do {                                                                    \
         struct lov_object                      *__obj = (obj);          \
         enum lov_layout_type                    __llt;                  \
                                                                         \
-        if (__obj->lo_owner != cfs_current())                           \
-                cfs_down_read(&__obj->lo_type_guard);                   \
+	lov_conf_freeze(__obj);						\
         __llt = __obj->lo_type;                                         \
         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
         lov_dispatch[__llt].op(__VA_ARGS__);                            \
-        if (__obj->lo_owner != cfs_current())                           \
-                cfs_up_read(&__obj->lo_type_guard);                     \
+	lov_conf_thaw(__obj);						\
 } while (0)
 
-static int lov_layout_change(const struct lu_env *env,
-                             struct lov_object *obj, enum lov_layout_type llt,
-                             const struct cl_object_conf *conf)
+static void lov_conf_lock(struct lov_object *lov)
 {
-        int result;
-        union lov_layout_state       *state = &lov_env_info(env)->lti_state;
-        const struct lov_layout_operations *old_ops;
-        const struct lov_layout_operations *new_ops;
+	LASSERT(lov->lo_owner != current);
+	down_write(&lov->lo_type_guard);
+	LASSERT(lov->lo_owner == NULL);
+	lov->lo_owner = current;
+}
 
-        LASSERT(0 <= obj->lo_type && obj->lo_type < ARRAY_SIZE(lov_dispatch));
-        LASSERT(0 <= llt && llt < ARRAY_SIZE(lov_dispatch));
-        ENTRY;
+static void lov_conf_unlock(struct lov_object *lov)
+{
+	lov->lo_owner = NULL;
+	up_write(&lov->lo_type_guard);
+}
 
-        old_ops = &lov_dispatch[obj->lo_type];
-        new_ops = &lov_dispatch[llt];
-
-        result = new_ops->llo_init(env, lu2lov_dev(obj->lo_cl.co_lu.lo_dev),
-                                   obj, conf, state);
-        if (result == 0) {
-                struct cl_object_header *hdr = cl_object_header(&obj->lo_cl);
-                void                    *cookie;
-                struct lu_env           *nested;
-                int                      refcheck;
-
-                cookie = cl_env_reenter();
-                nested = cl_env_get(&refcheck);
-                if (!IS_ERR(nested))
-                        cl_object_prune(nested, &obj->lo_cl);
-                else
-                        result = PTR_ERR(nested);
-                cl_env_put(nested, &refcheck);
-                cl_env_reexit(cookie);
-
-                old_ops->llo_fini(env, obj, &obj->u);
-                LASSERT(cfs_list_empty(&hdr->coh_locks));
-                LASSERT(hdr->coh_tree.rnode == NULL);
-                LASSERT(hdr->coh_pages == 0);
-
-                new_ops->llo_install(env, obj, state);
-                obj->lo_type = llt;
-        } else
-                new_ops->llo_fini(env, obj, state);
-        RETURN(result);
+static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov)
+{
+	struct l_wait_info lwi = { 0 };
+	ENTRY;
+
+	while (atomic_read(&lov->lo_active_ios) > 0) {
+		CDEBUG(D_INODE, "file:"DFID" wait for active IO, now: %d.\n",
+			PFID(lu_object_fid(lov2lu(lov))),
+			atomic_read(&lov->lo_active_ios));
+
+		l_wait_event(lov->lo_waitq,
+			     atomic_read(&lov->lo_active_ios) == 0, &lwi);
+	}
+	RETURN(0);
+}
+
+static int lov_layout_change(const struct lu_env *unused,
+			     struct lov_object *lov,
+			     const struct cl_object_conf *conf)
+{
+	int result;
+	enum lov_layout_type llt = LLT_EMPTY;
+	union lov_layout_state *state = &lov->u;
+	const struct lov_layout_operations *old_ops;
+	const struct lov_layout_operations *new_ops;
+
+	void *cookie;
+	struct lu_env *env;
+	int refcheck;
+	ENTRY;
+
+	LASSERT(0 <= lov->lo_type && lov->lo_type < ARRAY_SIZE(lov_dispatch));
+
+	if (conf->u.coc_md != NULL)
+		llt = lov_type(conf->u.coc_md->lsm);
+	LASSERT(0 <= llt && llt < ARRAY_SIZE(lov_dispatch));
+
+	cookie = cl_env_reenter();
+	env = cl_env_get(&refcheck);
+	if (IS_ERR(env)) {
+		cl_env_reexit(cookie);
+		RETURN(PTR_ERR(env));
+	}
+
+	CDEBUG(D_INODE, DFID" from %s to %s\n",
+	       PFID(lu_object_fid(lov2lu(lov))),
+	       llt2str(lov->lo_type), llt2str(llt));
+
+	old_ops = &lov_dispatch[lov->lo_type];
+	new_ops = &lov_dispatch[llt];
+
+	result = cl_object_prune(env, &lov->lo_cl);
+	if (result != 0)
+		GOTO(out, result);
+
+	result = old_ops->llo_delete(env, lov, &lov->u);
+	if (result == 0) {
+		old_ops->llo_fini(env, lov, &lov->u);
+
+		LASSERT(atomic_read(&lov->lo_active_ios) == 0);
+
+		lov->lo_type = LLT_EMPTY;
+		/* page bufsize fixup */
+		cl_object_header(&lov->lo_cl)->coh_page_bufsize -=
+			lov_page_slice_fixup(lov, NULL);
+
+		result = new_ops->llo_init(env,
+					lu2lov_dev(lov->lo_cl.co_lu.lo_dev),
+					lov, conf, state);
+		if (result == 0) {
+			new_ops->llo_install(env, lov, state);
+			lov->lo_type = llt;
+		} else {
+			new_ops->llo_delete(env, lov, state);
+			new_ops->llo_fini(env, lov, state);
+			/* this file becomes an EMPTY file. */
+		}
+	}
+
+out:
+	cl_env_put(env, &refcheck);
+	cl_env_reexit(cookie);
+	RETURN(result);
 }
 
 /*****************************************************************************
@@ -514,52 +850,84 @@ static int lov_layout_change(const struct lu_env *env,
  * Lov object operations.
  *
  */
-
 int lov_object_init(const struct lu_env *env, struct lu_object *obj,
                     const struct lu_object_conf *conf)
 {
         struct lov_device            *dev   = lu2lov_dev(obj->lo_dev);
         struct lov_object            *lov   = lu2lov(obj);
         const struct cl_object_conf  *cconf = lu2cl_conf(conf);
-        union  lov_layout_state      *set   = &lov_env_info(env)->lti_state;
+        union  lov_layout_state      *set   = &lov->u;
         const struct lov_layout_operations *ops;
         int result;
 
         ENTRY;
-        cfs_init_rwsem(&lov->lo_type_guard);
+	init_rwsem(&lov->lo_type_guard);
+	atomic_set(&lov->lo_active_ios, 0);
+	init_waitqueue_head(&lov->lo_waitq);
+
+	cl_object_page_init(lu2cl(obj), sizeof(struct lov_page));
 
         /* no locking is necessary, as object is being created */
-        lov->lo_type = cconf->u.coc_md->lsm != NULL ? LLT_RAID0 : LLT_EMPTY;
+	lov->lo_type = lov_type(cconf->u.coc_md->lsm);
         ops = &lov_dispatch[lov->lo_type];
         result = ops->llo_init(env, dev, lov, cconf, set);
         if (result == 0)
                 ops->llo_install(env, lov, set);
-        else
-                ops->llo_fini(env, lov, set);
         RETURN(result);
 }
 
 static int lov_conf_set(const struct lu_env *env, struct cl_object *obj,
                         const struct cl_object_conf *conf)
 {
-        struct lov_object *lov = cl2lov(obj);
-        int result;
-
-        ENTRY;
-        /*
-         * Currently only LLT_EMPTY -> LLT_RAID0 transition is supported.
-         */
-        LASSERT(lov->lo_owner != cfs_current());
-        cfs_down_write(&lov->lo_type_guard);
-        LASSERT(lov->lo_owner == NULL);
-        lov->lo_owner = cfs_current();
-        if (lov->lo_type == LLT_EMPTY && conf->u.coc_md->lsm != NULL)
-                result = lov_layout_change(env, lov, LLT_RAID0, conf);
-        else
-                result = -EOPNOTSUPP;
-        lov->lo_owner = NULL;
-        cfs_up_write(&lov->lo_type_guard);
-        RETURN(result);
+	struct lov_stripe_md	*lsm = NULL;
+	struct lov_object	*lov = cl2lov(obj);
+	int			 result = 0;
+	ENTRY;
+
+	lov_conf_lock(lov);
+	if (conf->coc_opc == OBJECT_CONF_INVALIDATE) {
+		lov->lo_layout_invalid = true;
+		GOTO(out, result = 0);
+	}
+
+	if (conf->coc_opc == OBJECT_CONF_WAIT) {
+		if (lov->lo_layout_invalid &&
+		    atomic_read(&lov->lo_active_ios) > 0) {
+			lov_conf_unlock(lov);
+			result = lov_layout_wait(env, lov);
+			lov_conf_lock(lov);
+		}
+		GOTO(out, result);
+	}
+
+	LASSERT(conf->coc_opc == OBJECT_CONF_SET);
+
+	if (conf->u.coc_md != NULL)
+		lsm = conf->u.coc_md->lsm;
+	if ((lsm == NULL && lov->lo_lsm == NULL) ||
+	    ((lsm != NULL && lov->lo_lsm != NULL) &&
+	     (lov->lo_lsm->lsm_layout_gen == lsm->lsm_layout_gen) &&
+	     (lov->lo_lsm->lsm_pattern == lsm->lsm_pattern))) {
+		/* same version of layout */
+		lov->lo_layout_invalid = false;
+		GOTO(out, result = 0);
+	}
+
+	/* will change layout - check if there still exists active IO. */
+	if (atomic_read(&lov->lo_active_ios) > 0) {
+		lov->lo_layout_invalid = true;
+		GOTO(out, result = -EBUSY);
+	}
+
+	result = lov_layout_change(env, lov, conf);
+	lov->lo_layout_invalid = result != 0;
+	EXIT;
+
+out:
+	lov_conf_unlock(lov);
+	CDEBUG(D_INODE, DFID" lo_layout_invalid=%d\n",
+	       PFID(lu_object_fid(lov2lu(lov))), lov->lo_layout_invalid);
+	RETURN(result);
 }
 
 static void lov_object_delete(const struct lu_env *env, struct lu_object *obj)
@@ -585,14 +953,14 @@ static void lov_object_free(const struct lu_env *env, struct lu_object *obj)
 static int lov_object_print(const struct lu_env *env, void *cookie,
                             lu_printer_t p, const struct lu_object *o)
 {
-        return LOV_2DISPATCH(lu2lov(o), llo_print, env, cookie, p, o);
+        return LOV_2DISPATCH_NOLOCK(lu2lov(o), llo_print, env, cookie, p, o);
 }
 
-struct cl_page *lov_page_init(const struct lu_env *env, struct cl_object *obj,
-                              struct cl_page *page, cfs_page_t *vmpage)
+int lov_page_init(const struct lu_env *env, struct cl_object *obj,
+		  struct cl_page *page, pgoff_t index)
 {
-        return LOV_2DISPATCH(cl2lov(obj),
-                             llo_page_init, env, obj, page, vmpage);
+	return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_page_init, env, obj, page,
+				    index);
 }
 
 /**
@@ -600,23 +968,11 @@ struct cl_page *lov_page_init(const struct lu_env *env, struct cl_object *obj,
  * layer. Dispatches to the appropriate layout io initialization method.
  */
 int lov_io_init(const struct lu_env *env, struct cl_object *obj,
-                struct cl_io *io)
+		struct cl_io *io)
 {
-        CL_IO_SLICE_CLEAN(lov_env_io(env), lis_cl);
-        /*
-         * Do not take lock in case of CIT_MISC io, because
-         *
-         *     - if this is an io for a glimpse, then we don't care;
-         *
-         *     - if this not a glimpse (writepage or lock cancellation), then
-         *       layout change cannot happen because a page or a lock
-         *       already exist; and
-         *
-         *     - lock ordering (lock mutex nests within layout rw-semaphore)
-         *       is obeyed in case of lock cancellation.
-         */
-        return LOV_2DISPATCH_MAYLOCK(cl2lov(obj), llo_io_init,
-                                     io->ci_type != CIT_MISC, env, obj, io);
+	CL_IO_SLICE_CLEAN(lov_env_io(env), lis_cl);
+	return LOV_2DISPATCH_MAYLOCK(cl2lov(obj), llo_io_init,
+				     !io->ci_ignore_layout, env, obj, io);
 }
 
 /**
@@ -632,28 +988,628 @@ static int lov_attr_get(const struct lu_env *env, struct cl_object *obj,
         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_getattr, env, obj, attr);
 }
 
-static int lov_attr_set(const struct lu_env *env, struct cl_object *obj,
-                        const struct cl_attr *attr, unsigned valid)
+static int lov_attr_update(const struct lu_env *env, struct cl_object *obj,
+			   const struct cl_attr *attr, unsigned valid)
 {
-        /*
-         * No dispatch is required here, as no layout implements this.
-         */
-        return 0;
+	/*
+	 * No dispatch is required here, as no layout implements this.
+	 */
+	return 0;
 }
 
 int lov_lock_init(const struct lu_env *env, struct cl_object *obj,
-                  struct cl_lock *lock, const struct cl_io *io)
+		  struct cl_lock *lock, const struct cl_io *io)
 {
-        return LOV_2DISPATCH(cl2lov(obj), llo_lock_init, env, obj, lock, io);
+	/* No need to lock because we've taken one refcount of layout.  */
+	return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_lock_init, env, obj, lock,
+				    io);
+}
+
+/**
+ * We calculate on which OST the mapping will end. If the length of mapping
+ * is greater than (stripe_size * stripe_count) then the last_stripe will
+ * will be one just before start_stripe. Else we check if the mapping
+ * intersects each OST and find last_stripe.
+ * This function returns the last_stripe and also sets the stripe_count
+ * over which the mapping is spread
+ *
+ * \param lsm [in]		striping information for the file
+ * \param fm_start [in]		logical start of mapping
+ * \param fm_end [in]		logical end of mapping
+ * \param start_stripe [in]	starting stripe of the mapping
+ * \param stripe_count [out]	the number of stripes across which to map is
+ *				returned
+ *
+ * \retval last_stripe		return the last stripe of the mapping
+ */
+static int fiemap_calc_last_stripe(struct lov_stripe_md *lsm,
+				   loff_t fm_start, loff_t fm_end,
+				   int start_stripe, int *stripe_count)
+{
+	int last_stripe;
+	loff_t obd_start;
+	loff_t obd_end;
+	int i, j;
+
+	if (fm_end - fm_start > lsm->lsm_stripe_size * lsm->lsm_stripe_count) {
+		last_stripe = (start_stripe < 1 ? lsm->lsm_stripe_count - 1 :
+							      start_stripe - 1);
+		*stripe_count = lsm->lsm_stripe_count;
+	} else {
+		for (j = 0, i = start_stripe; j < lsm->lsm_stripe_count;
+		     i = (i + 1) % lsm->lsm_stripe_count, j++) {
+			if ((lov_stripe_intersects(lsm, i, fm_start, fm_end,
+						   &obd_start, &obd_end)) == 0)
+				break;
+		}
+		*stripe_count = j;
+		last_stripe = (start_stripe + j - 1) % lsm->lsm_stripe_count;
+	}
+
+	return last_stripe;
+}
+
+/**
+ * Set fe_device and copy extents from local buffer into main return buffer.
+ *
+ * \param fiemap [out]		fiemap to hold all extents
+ * \param lcl_fm_ext [in]	array of fiemap extents get from OSC layer
+ * \param ost_index [in]	OST index to be written into the fm_device
+ *				field for each extent
+ * \param ext_count [in]	number of extents to be copied
+ * \param current_extent [in]	where to start copying in the extent array
+ */
+static void fiemap_prepare_and_copy_exts(struct fiemap *fiemap,
+					 struct ll_fiemap_extent *lcl_fm_ext,
+					 int ost_index, unsigned int ext_count,
+					 int current_extent)
+{
+	char		*to;
+	unsigned int	ext;
+
+	for (ext = 0; ext < ext_count; ext++) {
+		lcl_fm_ext[ext].fe_device = ost_index;
+		lcl_fm_ext[ext].fe_flags |= FIEMAP_EXTENT_NET;
+	}
+
+	/* Copy fm_extent's from fm_local to return buffer */
+	to = (char *)fiemap + fiemap_count_to_size(current_extent);
+	memcpy(to, lcl_fm_ext, ext_count * sizeof(struct ll_fiemap_extent));
+}
+
+#define FIEMAP_BUFFER_SIZE 4096
+
+/**
+ * Non-zero fe_logical indicates that this is a continuation FIEMAP
+ * call. The local end offset and the device are sent in the first
+ * fm_extent. This function calculates the stripe number from the index.
+ * This function returns a stripe_no on which mapping is to be restarted.
+ *
+ * This function returns fm_end_offset which is the in-OST offset at which
+ * mapping should be restarted. If fm_end_offset=0 is returned then caller
+ * will re-calculate proper offset in next stripe.
+ * Note that the first extent is passed to lov_get_info via the value field.
+ *
+ * \param fiemap [in]		fiemap request header
+ * \param lsm [in]		striping information for the file
+ * \param fm_start [in]		logical start of mapping
+ * \param fm_end [in]		logical end of mapping
+ * \param start_stripe [out]	starting stripe will be returned in this
+ */
+static loff_t fiemap_calc_fm_end_offset(struct fiemap *fiemap,
+					struct lov_stripe_md *lsm,
+					loff_t fm_start, loff_t fm_end,
+					int *start_stripe)
+{
+	loff_t local_end = fiemap->fm_extents[0].fe_logical;
+	loff_t lun_start;
+	loff_t lun_end;
+	loff_t fm_end_offset;
+	int stripe_no = -1;
+	int i;
+
+	if (fiemap->fm_extent_count == 0 ||
+	    fiemap->fm_extents[0].fe_logical == 0)
+		return 0;
+
+	/* Find out stripe_no from ost_index saved in the fe_device */
+	for (i = 0; i < lsm->lsm_stripe_count; i++) {
+		struct lov_oinfo *oinfo = lsm->lsm_oinfo[i];
+
+		if (lov_oinfo_is_dummy(oinfo))
+			continue;
+
+		if (oinfo->loi_ost_idx == fiemap->fm_extents[0].fe_device) {
+			stripe_no = i;
+			break;
+		}
+	}
+
+	if (stripe_no == -1)
+		return -EINVAL;
+
+	/* If we have finished mapping on previous device, shift logical
+	 * offset to start of next device */
+	if (lov_stripe_intersects(lsm, stripe_no, fm_start, fm_end,
+				  &lun_start, &lun_end) != 0 &&
+	    local_end < lun_end) {
+		fm_end_offset = local_end;
+		*start_stripe = stripe_no;
+	} else {
+		/* This is a special value to indicate that caller should
+		 * calculate offset in next stripe. */
+		fm_end_offset = 0;
+		*start_stripe = (stripe_no + 1) % lsm->lsm_stripe_count;
+	}
+
+	return fm_end_offset;
+}
+
+/**
+ * Break down the FIEMAP request and send appropriate calls to individual OSTs.
+ * This also handles the restarting of FIEMAP calls in case mapping overflows
+ * the available number of extents in single call.
+ *
+ * \param env [in]		lustre environment
+ * \param obj [in]		file object
+ * \param fmkey [in]		fiemap request header and other info
+ * \param fiemap [out]		fiemap buffer holding retrived map extents
+ * \param buflen [in/out]	max buffer length of @fiemap, when iterate
+ *				each OST, it is used to limit max map needed
+ * \retval 0	success
+ * \retval < 0	error
+ */
+static int lov_object_fiemap(const struct lu_env *env, struct cl_object *obj,
+			     struct ll_fiemap_info_key *fmkey,
+			     struct fiemap *fiemap, size_t *buflen)
+{
+	struct lov_stripe_md	*lsm;
+	struct cl_object	*subobj = NULL;
+	struct lov_obd		*lov = lu2lov_dev(obj->co_lu.lo_dev)->ld_lov;
+	struct fiemap		*fm_local = NULL;
+	struct ll_fiemap_extent	*lcl_fm_ext;
+	loff_t			fm_start;
+	loff_t			fm_end;
+	loff_t			fm_length;
+	loff_t			fm_end_offset;
+	int			count_local;
+	int			ost_index = 0;
+	int			start_stripe;
+	int			current_extent = 0;
+	int			rc = 0;
+	int			last_stripe;
+	int			cur_stripe = 0;
+	int			cur_stripe_wrap = 0;
+	int			stripe_count;
+	unsigned int		buffer_size = FIEMAP_BUFFER_SIZE;
+	/* Whether have we collected enough extents */
+	bool			enough = false;
+	/* EOF for object */
+	bool			ost_eof = false;
+	/* done with required mapping for this OST? */
+	bool			ost_done = false;
+	ENTRY;
+
+	lsm = lov_lsm_addref(cl2lov(obj));
+	if (lsm == NULL)
+		RETURN(-ENODATA);
+
+	/**
+	 * If the stripe_count > 1 and the application does not understand
+	 * DEVICE_ORDER flag, it cannot interpret the extents correctly.
+	 */
+	if (lsm->lsm_stripe_count > 1 && !(fiemap->fm_flags &
+					   FIEMAP_FLAG_DEVICE_ORDER))
+		GOTO(out, rc = -ENOTSUPP);
+
+	if (lsm_is_released(lsm)) {
+		if (fiemap->fm_start < fmkey->oa.o_size) {
+			/**
+			 * released file, return a minimal FIEMAP if
+			 * request fits in file-size.
+			 */
+			fiemap->fm_mapped_extents = 1;
+			fiemap->fm_extents[0].fe_logical = fiemap->fm_start;
+			if (fiemap->fm_start + fiemap->fm_length <
+			    fmkey->oa.o_size)
+				fiemap->fm_extents[0].fe_length =
+					fiemap->fm_length;
+			else
+				fiemap->fm_extents[0].fe_length =
+					fmkey->oa.o_size - fiemap->fm_start;
+			fiemap->fm_extents[0].fe_flags |=
+				FIEMAP_EXTENT_UNKNOWN | FIEMAP_EXTENT_LAST;
+		}
+		GOTO(out, rc = 0);
+	}
+
+	if (fiemap_count_to_size(fiemap->fm_extent_count) < buffer_size)
+		buffer_size = fiemap_count_to_size(fiemap->fm_extent_count);
+
+	OBD_ALLOC_LARGE(fm_local, buffer_size);
+	if (fm_local == NULL)
+		GOTO(out, rc = -ENOMEM);
+	lcl_fm_ext = &fm_local->fm_extents[0];
+	count_local = fiemap_size_to_count(buffer_size);
+
+	fm_start = fiemap->fm_start;
+	fm_length = fiemap->fm_length;
+	/* Calculate start stripe, last stripe and length of mapping */
+	start_stripe = lov_stripe_number(lsm, fm_start);
+	fm_end = (fm_length == ~0ULL) ? fmkey->oa.o_size :
+					fm_start + fm_length - 1;
+	/* If fm_length != ~0ULL but fm_start_fm_length-1 exceeds file size */
+	if (fm_end > fmkey->oa.o_size)
+		fm_end = fmkey->oa.o_size;
+
+	last_stripe = fiemap_calc_last_stripe(lsm, fm_start, fm_end,
+					      start_stripe, &stripe_count);
+	fm_end_offset = fiemap_calc_fm_end_offset(fiemap, lsm, fm_start, fm_end,
+						  &start_stripe);
+	if (fm_end_offset == -EINVAL)
+		GOTO(out, rc = -EINVAL);
+
+	/**
+	 * Requested extent count exceeds the fiemap buffer size, shrink our
+	 * ambition.
+	 */
+	if (fiemap_count_to_size(fiemap->fm_extent_count) > *buflen)
+		fiemap->fm_extent_count = fiemap_size_to_count(*buflen);
+	if (fiemap->fm_extent_count == 0)
+		count_local = 0;
+
+	/* Check each stripe */
+	for (cur_stripe = start_stripe; stripe_count > 0;
+	     --stripe_count,
+	     cur_stripe = (cur_stripe + 1) % lsm->lsm_stripe_count) {
+		loff_t req_fm_len; /* Stores length of required mapping */
+		loff_t len_mapped_single_call;
+		loff_t lun_start;
+		loff_t lun_end;
+		loff_t obd_object_end;
+		unsigned int ext_count;
+
+		cur_stripe_wrap = cur_stripe;
+
+		/* Find out range of mapping on this stripe */
+		if ((lov_stripe_intersects(lsm, cur_stripe, fm_start, fm_end,
+					   &lun_start, &obd_object_end)) == 0)
+			continue;
+
+		if (lov_oinfo_is_dummy(lsm->lsm_oinfo[cur_stripe]))
+			GOTO(out, rc = -EIO);
+
+		/* If this is a continuation FIEMAP call and we are on
+		 * starting stripe then lun_start needs to be set to
+		 * fm_end_offset */
+		if (fm_end_offset != 0 && cur_stripe == start_stripe)
+			lun_start = fm_end_offset;
+
+		if (fm_length != ~0ULL) {
+			/* Handle fm_start + fm_length overflow */
+			if (fm_start + fm_length < fm_start)
+				fm_length = ~0ULL - fm_start;
+			lun_end = lov_size_to_stripe(lsm, fm_start + fm_length,
+						     cur_stripe);
+		} else {
+			lun_end = ~0ULL;
+		}
+
+		if (lun_start == lun_end)
+			continue;
+
+		req_fm_len = obd_object_end - lun_start;
+		fm_local->fm_length = 0;
+		len_mapped_single_call = 0;
+
+		/* find lobsub object */
+		subobj = lov_find_subobj(env, cl2lov(obj), lsm,
+					     cur_stripe);
+		if (IS_ERR(subobj))
+			GOTO(out, rc = PTR_ERR(subobj));
+		/* If the output buffer is very large and the objects have many
+		 * extents we may need to loop on a single OST repeatedly */
+		ost_eof = false;
+		ost_done = false;
+		do {
+			if (fiemap->fm_extent_count > 0) {
+				/* Don't get too many extents. */
+				if (current_extent + count_local >
+				    fiemap->fm_extent_count)
+					count_local = fiemap->fm_extent_count -
+						      current_extent;
+			}
+
+			lun_start += len_mapped_single_call;
+			fm_local->fm_length = req_fm_len -
+					      len_mapped_single_call;
+			req_fm_len = fm_local->fm_length;
+			fm_local->fm_extent_count = enough ? 1 : count_local;
+			fm_local->fm_mapped_extents = 0;
+			fm_local->fm_flags = fiemap->fm_flags;
+
+			ost_index = lsm->lsm_oinfo[cur_stripe]->loi_ost_idx;
+
+			if (ost_index < 0 ||
+			    ost_index >= lov->desc.ld_tgt_count)
+				GOTO(obj_put, rc = -EINVAL);
+			/* If OST is inactive, return extent with UNKNOWN
+			 * flag. */
+			if (!lov->lov_tgts[ost_index]->ltd_active) {
+				fm_local->fm_flags |= FIEMAP_EXTENT_LAST;
+				fm_local->fm_mapped_extents = 1;
+
+				lcl_fm_ext[0].fe_logical = lun_start;
+				lcl_fm_ext[0].fe_length = obd_object_end -
+							  lun_start;
+				lcl_fm_ext[0].fe_flags |= FIEMAP_EXTENT_UNKNOWN;
+
+				goto inactive_tgt;
+			}
+
+			fm_local->fm_start = lun_start;
+			fm_local->fm_flags &= ~FIEMAP_FLAG_DEVICE_ORDER;
+			memcpy(&fmkey->fiemap, fm_local, sizeof(*fm_local));
+			*buflen = fiemap_count_to_size(
+						fm_local->fm_extent_count);
+
+			rc = cl_object_fiemap(env, subobj, fmkey, fm_local,
+					      buflen);
+			if (rc != 0)
+				GOTO(obj_put, rc);
+inactive_tgt:
+			ext_count = fm_local->fm_mapped_extents;
+			if (ext_count == 0) {
+				ost_done = true;
+				/* If last stripe has hold at the end,
+				 * we need to return */
+				if (cur_stripe_wrap == last_stripe) {
+					fiemap->fm_mapped_extents = 0;
+					goto finish;
+				}
+				break;
+			} else if (enough) {
+				/*
+				 * We've collected enough extents and there are
+				 * more extents after it.
+				 */
+				goto finish;
+			}
+
+			/* If we just need num of extents, got to next device */
+			if (fiemap->fm_extent_count == 0) {
+				current_extent += ext_count;
+				break;
+			}
+
+			/* prepare to copy retrived map extents */
+			len_mapped_single_call =
+				lcl_fm_ext[ext_count - 1].fe_logical -
+				lun_start + lcl_fm_ext[ext_count - 1].fe_length;
+
+			/* Have we finished mapping on this device? */
+			if (req_fm_len <= len_mapped_single_call)
+				ost_done = true;
+
+			/* Clear the EXTENT_LAST flag which can be present on
+			 * the last extent */
+			if (lcl_fm_ext[ext_count - 1].fe_flags &
+			    FIEMAP_EXTENT_LAST)
+				lcl_fm_ext[ext_count - 1].fe_flags &=
+							~FIEMAP_EXTENT_LAST;
+			if (lov_stripe_size(lsm,
+					lcl_fm_ext[ext_count - 1].fe_logical +
+					lcl_fm_ext[ext_count - 1].fe_length,
+					cur_stripe) >= fmkey->oa.o_size)
+				ost_eof = true;
+
+			fiemap_prepare_and_copy_exts(fiemap, lcl_fm_ext,
+						     ost_index, ext_count,
+						     current_extent);
+			current_extent += ext_count;
+
+			/* Ran out of available extents? */
+			if (current_extent >= fiemap->fm_extent_count)
+				enough = true;
+		} while (!ost_done && !ost_eof);
+
+		cl_object_put(env, subobj);
+		subobj = NULL;
+
+		if (cur_stripe_wrap == last_stripe)
+			goto finish;
+	} /* for each stripe */
+finish:
+	/* Indicate that we are returning device offsets unless file just has
+	 * single stripe */
+	if (lsm->lsm_stripe_count > 1)
+		fiemap->fm_flags |= FIEMAP_FLAG_DEVICE_ORDER;
+
+	if (fiemap->fm_extent_count == 0)
+		goto skip_last_device_calc;
+
+	/* Check if we have reached the last stripe and whether mapping for that
+	 * stripe is done. */
+	if ((cur_stripe_wrap == last_stripe) && (ost_done || ost_eof))
+		fiemap->fm_extents[current_extent - 1].fe_flags |=
+							     FIEMAP_EXTENT_LAST;
+skip_last_device_calc:
+	fiemap->fm_mapped_extents = current_extent;
+obj_put:
+	if (subobj != NULL)
+		cl_object_put(env, subobj);
+out:
+	if (fm_local != NULL)
+		OBD_FREE_LARGE(fm_local, buffer_size);
+	lov_lsm_put(obj, lsm);
+	RETURN(rc);
+}
+
+static int lov_dispatch_obd_info_get(const struct lu_env *env,
+				     struct cl_object *obj,
+				     struct obd_info *oinfo,
+				     struct ptlrpc_request_set *set)
+{
+	struct cl_object	*subobj = NULL;
+	struct lov_obd		*lov = lu2lov_dev(obj->co_lu.lo_dev)->ld_lov;
+	struct lov_request_set	*lovset;
+	struct list_head	*pos;
+	struct lov_request	*req;
+	int			rc;
+	int			rc2;
+	ENTRY;
+
+	rc = lov_prep_getattr_set(lov2obd(lov)->obd_self_export, oinfo,
+				  &lovset);
+	if (rc != 0)
+		RETURN(rc);
+
+	CDEBUG(D_INFO, "objid "DOSTID": %ux%u byte stripes.\n",
+	       POSTID(&oinfo->oi_md->lsm_oi),
+	       oinfo->oi_md->lsm_stripe_count,
+	       oinfo->oi_md->lsm_stripe_size);
+
+	list_for_each(pos, &lovset->set_list) {
+		req = list_entry(pos, struct lov_request, rq_link);
+
+		CDEBUG(D_INFO, "objid "DOSTID"[%d] has subobj "DOSTID" at idx"
+		       "%u\n", POSTID(&oinfo->oi_oa->o_oi), req->rq_stripe,
+		       POSTID(&req->rq_oi.oi_oa->o_oi), req->rq_idx);
+		subobj = lov_find_subobj(env, cl2lov(obj), oinfo->oi_md,
+					 req->rq_stripe);
+		if (IS_ERR(subobj))
+			GOTO(errout, rc = PTR_ERR(subobj));
+
+		rc = cl_object_obd_info_get(env, subobj, &req->rq_oi, set);
+		cl_object_put(env, subobj);
+		if (rc != 0) {
+			CERROR("%s: getattr objid "DOSTID" subobj"
+			       DOSTID" on OST idx %d: rc = %d\n",
+			       lov2obd(lov)->obd_name,
+			       POSTID(&oinfo->oi_oa->o_oi),
+			       POSTID(&req->rq_oi.oi_oa->o_oi),
+			       req->rq_idx, rc);
+			GOTO(errout, rc);
+		}
+	}
+
+	if (!list_empty(&set->set_requests)) {
+		LASSERT(rc == 0);
+		LASSERT(set->set_interpret == NULL);
+		set->set_interpret = lov_getattr_interpret;
+		set->set_arg = lovset;
+		GOTO(out, rc);
+	}
+errout:
+	if (rc)
+		atomic_set(&lovset->set_completes, 0);
+	rc2 = lov_fini_getattr_set(lovset);
+	rc = rc != 0 ? rc : rc2;
+out:
+	RETURN(rc);
+}
+
+static int lov_object_data_version(const struct lu_env *env,
+				   struct cl_object *obj, __u64 *data_version,
+				   int flags)
+{
+	struct ptlrpc_request_set	*set;
+	struct obd_info			oinfo =  { { { 0 } } };
+	struct obdo			*obdo = NULL;
+	struct lov_stripe_md		*lsm;
+	int				rc;
+	ENTRY;
+
+	lsm = lov_lsm_addref(cl2lov(obj));
+	if (!lsm_has_objects(lsm)) {
+		/* If no stripe, we consider version is 0. */
+		*data_version = 0;
+		GOTO(out, rc = 0);
+	}
+
+	OBD_ALLOC_PTR(obdo);
+	if (obdo == NULL)
+		GOTO(out, rc = -ENOMEM);
+
+	oinfo.oi_md = lsm;
+	oinfo.oi_oa = obdo;
+	obdo->o_oi = lsm->lsm_oi;
+	obdo->o_mode = S_IFREG;
+	obdo->o_valid = OBD_MD_FLID | OBD_MD_FLGROUP | OBD_MD_FLTYPE;
+	if (flags & (LL_DV_RD_FLUSH | LL_DV_WR_FLUSH)) {
+		obdo->o_valid |= OBD_MD_FLFLAGS;
+		obdo->o_flags |= OBD_FL_SRVLOCK;
+		if (flags & LL_DV_WR_FLUSH)
+			obdo->o_flags |= OBD_FL_FLUSH;
+	}
+
+	set = ptlrpc_prep_set();
+	if (set == NULL)
+		GOTO(out_obdo, rc = -ENOMEM);
+
+	rc = lov_dispatch_obd_info_get(env, obj, &oinfo, set);
+	if (rc == 0)
+		rc = ptlrpc_set_wait(set);
+	ptlrpc_set_destroy(set);
+	if (rc == 0) {
+		oinfo.oi_oa->o_valid &= OBD_MD_FLDATAVERSION | OBD_MD_FLFLAGS;
+		if (flags & LL_DV_WR_FLUSH &&
+		    !(oinfo.oi_oa->o_valid & OBD_MD_FLFLAGS &&
+		      oinfo.oi_oa->o_flags & OBD_FL_FLUSH))
+			rc = -EOPNOTSUPP;
+		else if (!(obdo->o_valid & OBD_MD_FLDATAVERSION))
+			rc = -EOPNOTSUPP;
+		else
+			*data_version = obdo->o_data_version;
+	}
+out_obdo:
+	OBD_FREE_PTR(obdo);
+out:
+	lov_lsm_put(obj, lsm);
+	RETURN(rc);
+}
+
+static int lov_object_getstripe(const struct lu_env *env, struct cl_object *obj,
+				struct lov_user_md __user *lum)
+{
+	struct lov_object	*lov = cl2lov(obj);
+	struct lov_stripe_md	*lsm;
+	int			rc = 0;
+	ENTRY;
+
+	lsm = lov_lsm_addref(lov);
+	if (lsm == NULL)
+		RETURN(-ENODATA);
+
+	rc = lov_getstripe(cl2lov(obj), lsm, lum);
+	lov_lsm_put(obj, lsm);
+	RETURN(rc);
+}
+
+static int lov_object_find_cbdata(const struct lu_env *env,
+				  struct cl_object *obj, ldlm_iterator_t iter,
+				  void *data)
+{
+	int rc;
+	ENTRY;
+
+	/* call cl_object_find_cbdata for sub obj */
+	rc = LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_find_cbdata,
+				  env, obj, iter, data);
+	RETURN(rc);
 }
 
 static const struct cl_object_operations lov_ops = {
-        .coo_page_init = lov_page_init,
-        .coo_lock_init = lov_lock_init,
-        .coo_io_init   = lov_io_init,
-        .coo_attr_get  = lov_attr_get,
-        .coo_attr_set  = lov_attr_set,
-        .coo_conf_set  = lov_conf_set
+	.coo_page_init    = lov_page_init,
+	.coo_lock_init    = lov_lock_init,
+	.coo_io_init      = lov_io_init,
+	.coo_attr_get     = lov_attr_get,
+	.coo_attr_update  = lov_attr_update,
+	.coo_conf_set     = lov_conf_set,
+	.coo_getstripe    = lov_object_getstripe,
+	.coo_find_cbdata  = lov_object_find_cbdata,
+	.coo_fiemap       = lov_object_fiemap,
+	.coo_data_version = lov_object_data_version,
 };
 
 static const struct lu_object_operations lov_lu_obj_ops = {
@@ -666,28 +1622,85 @@ static const struct lu_object_operations lov_lu_obj_ops = {
 };
 
 struct lu_object *lov_object_alloc(const struct lu_env *env,
-                                   const struct lu_object_header *unused,
-                                   struct lu_device *dev)
+				   const struct lu_object_header *unused,
+				   struct lu_device *dev)
 {
-        struct lov_object *lov;
-        struct lu_object  *obj;
+	struct lov_object *lov;
+	struct lu_object  *obj;
+
+	ENTRY;
+	OBD_SLAB_ALLOC_PTR_GFP(lov, lov_object_kmem, GFP_NOFS);
+	if (lov != NULL) {
+		obj = lov2lu(lov);
+		lu_object_init(obj, NULL, dev);
+		lov->lo_cl.co_ops = &lov_ops;
+		lov->lo_type = -1; /* invalid, to catch uninitialized type */
+		/*
+		 * object io operation vector (cl_object::co_iop) is installed
+		 * later in lov_object_init(), as different vectors are used
+		 * for object with different layouts.
+		 */
+		obj->lo_ops = &lov_lu_obj_ops;
+	} else
+		obj = NULL;
+	RETURN(obj);
+}
 
-        ENTRY;
-        OBD_SLAB_ALLOC_PTR_GFP(lov, lov_object_kmem, CFS_ALLOC_IO);
-        if (lov != NULL) {
-                obj = lov2lu(lov);
-                lu_object_init(obj, NULL, dev);
-                lov->lo_cl.co_ops = &lov_ops;
-                lov->lo_type = -1; /* invalid, to catch uninitialized type */
-                /*
-                 * object io operation vector (cl_object::co_iop) is installed
-                 * later in lov_object_init(), as different vectors are used
-                 * for object with different layouts.
-                 */
-                obj->lo_ops = &lov_lu_obj_ops;
-        } else
-                obj = NULL;
-        RETURN(obj);
+struct lov_stripe_md *lov_lsm_addref(struct lov_object *lov)
+{
+	struct lov_stripe_md *lsm = NULL;
+
+	lov_conf_freeze(lov);
+	if (lov->lo_lsm != NULL) {
+		lsm = lsm_addref(lov->lo_lsm);
+		CDEBUG(D_INODE, "lsm %p addref %d/%d by %p.\n",
+			lsm, atomic_read(&lsm->lsm_refc),
+			lov->lo_layout_invalid, current);
+	}
+	lov_conf_thaw(lov);
+	return lsm;
+}
+
+int lov_read_and_clear_async_rc(struct cl_object *clob)
+{
+	struct lu_object *luobj;
+	int rc = 0;
+	ENTRY;
+
+	luobj = lu_object_locate(&cl_object_header(clob)->coh_lu,
+				 &lov_device_type);
+	if (luobj != NULL) {
+		struct lov_object *lov = lu2lov(luobj);
+
+		lov_conf_freeze(lov);
+		switch (lov->lo_type) {
+		case LLT_RAID0: {
+			struct lov_stripe_md *lsm;
+			int i;
+
+			lsm = lov->lo_lsm;
+			LASSERT(lsm != NULL);
+			for (i = 0; i < lsm->lsm_stripe_count; i++) {
+				struct lov_oinfo *loi = lsm->lsm_oinfo[i];
+
+				if (lov_oinfo_is_dummy(loi))
+					continue;
+
+				if (loi->loi_ar.ar_rc && !rc)
+					rc = loi->loi_ar.ar_rc;
+				loi->loi_ar.ar_rc = 0;
+			}
+		}
+		case LLT_RELEASED:
+		case LLT_EMPTY:
+			break;
+		default:
+			LBUG();
+		}
+		lov_conf_thaw(lov);
+	}
+	RETURN(rc);
 }
+EXPORT_SYMBOL(lov_read_and_clear_async_rc);
 
 /** @} lov */