Initial import

6 files changed, 3695 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lustre/lmv/Makefile b/drivers/staging/lustre/lustre/lmv/Makefile
new file mode 100644
index 000000000..a7a15369a
--- /dev/null
+++ b/drivers/staging/lustre/lustre/lmv/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_LUSTRE_FS) += lmv.o
+lmv-y := lmv_obd.o lmv_intent.o lmv_fld.o
+lmv-$(CONFIG_PROC_FS) += lproc_lmv.o
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_fld.c b/drivers/staging/lustre/lustre/lmv/lmv_fld.c
new file mode 100644
index 000000000..ee235926f
--- /dev/null
+++ b/drivers/staging/lustre/lustre/lmv/lmv_fld.c
@@ -0,0 +1,83 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2013, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#define DEBUG_SUBSYSTEM S_LMV
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <asm/div64.h>
+#include <linux/seq_file.h>
+
+#include "../include/obd_support.h"
+#include "../include/lustre/lustre_idl.h"
+#include "../include/lustre_fid.h"
+#include "../include/lustre_lib.h"
+#include "../include/lustre_net.h"
+#include "../include/lustre_dlm.h"
+#include "../include/obd_class.h"
+#include "../include/lprocfs_status.h"
+#include "lmv_internal.h"
+
+int lmv_fld_lookup(struct lmv_obd *lmv,
+		   const struct lu_fid *fid,
+		   u32 *mds)
+{
+	int rc;
+
+	/* FIXME: Currently ZFS still use local seq for ROOT unfortunately, and
+	 * this fid_is_local check should be removed once LU-2240 is fixed */
+	LASSERTF((fid_seq_in_fldb(fid_seq(fid)) ||
+		  fid_seq_is_local_file(fid_seq(fid))) &&
+		 fid_is_sane(fid), DFID" is insane!\n", PFID(fid));
+
+	rc = fld_client_lookup(&lmv->lmv_fld, fid_seq(fid), mds,
+			       LU_SEQ_RANGE_MDT, NULL);
+	if (rc) {
+		CERROR("Error while looking for mds number. Seq %#llx, err = %d\n",
+		       fid_seq(fid), rc);
+		return rc;
+	}
+
+	CDEBUG(D_INODE, "FLD lookup got mds #%x for fid="DFID"\n",
+	       *mds, PFID(fid));
+
+	if (*mds >= lmv->desc.ld_tgt_count) {
+		CERROR("FLD lookup got invalid mds #%x (max: %x) for fid=" DFID "\n", *mds, lmv->desc.ld_tgt_count,
+		       PFID(fid));
+		rc = -EINVAL;
+	}
+	return rc;
+}
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_intent.c b/drivers/staging/lustre/lustre/lmv/lmv_intent.c
new file mode 100644
index 000000000..d22d57b4f
--- /dev/null
+++ b/drivers/staging/lustre/lustre/lmv/lmv_intent.c
@@ -0,0 +1,323 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#define DEBUG_SUBSYSTEM S_LMV
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <asm/div64.h>
+#include <linux/seq_file.h>
+#include <linux/namei.h>
+#include "../include/lustre_intent.h"
+#include "../include/obd_support.h"
+#include "../include/lustre/lustre_idl.h"
+#include "../include/lustre_lib.h"
+#include "../include/lustre_net.h"
+#include "../include/lustre_dlm.h"
+#include "../include/obd_class.h"
+#include "../include/lprocfs_status.h"
+#include "lmv_internal.h"
+
+static int lmv_intent_remote(struct obd_export *exp, void *lmm,
+			     int lmmsize, struct lookup_intent *it,
+			     const struct lu_fid *parent_fid, int flags,
+			     struct ptlrpc_request **reqp,
+			     ldlm_blocking_callback cb_blocking,
+			     __u64 extra_lock_flags)
+{
+	struct obd_device	*obd = exp->exp_obd;
+	struct lmv_obd		*lmv = &obd->u.lmv;
+	struct ptlrpc_request	*req = NULL;
+	struct lustre_handle	plock;
+	struct md_op_data	*op_data;
+	struct lmv_tgt_desc	*tgt;
+	struct mdt_body		*body;
+	int			pmode;
+	int			rc = 0;
+
+	body = req_capsule_server_get(&(*reqp)->rq_pill, &RMF_MDT_BODY);
+	if (body == NULL)
+		return -EPROTO;
+
+	LASSERT((body->valid & OBD_MD_MDS));
+
+	/*
+	 * Unfortunately, we have to lie to MDC/MDS to retrieve
+	 * attributes llite needs and provideproper locking.
+	 */
+	if (it->it_op & IT_LOOKUP)
+		it->it_op = IT_GETATTR;
+
+	/*
+	 * We got LOOKUP lock, but we really need attrs.
+	 */
+	pmode = it->d.lustre.it_lock_mode;
+	if (pmode) {
+		plock.cookie = it->d.lustre.it_lock_handle;
+		it->d.lustre.it_lock_mode = 0;
+		it->d.lustre.it_data = NULL;
+	}
+
+	LASSERT(fid_is_sane(&body->fid1));
+
+	tgt = lmv_find_target(lmv, &body->fid1);
+	if (IS_ERR(tgt)) {
+		rc = PTR_ERR(tgt);
+		goto out;
+	}
+
+	OBD_ALLOC_PTR(op_data);
+	if (op_data == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	op_data->op_fid1 = body->fid1;
+	/* Sent the parent FID to the remote MDT */
+	if (parent_fid != NULL) {
+		/* The parent fid is only for remote open to
+		 * check whether the open is from OBF,
+		 * see mdt_cross_open */
+		LASSERT(it->it_op & IT_OPEN);
+		op_data->op_fid2 = *parent_fid;
+		/* Add object FID to op_fid3, in case it needs to check stale
+		 * (M_CHECK_STALE), see mdc_finish_intent_lock */
+		op_data->op_fid3 = body->fid1;
+	}
+
+	op_data->op_bias = MDS_CROSS_REF;
+	CDEBUG(D_INODE, "REMOTE_INTENT with fid="DFID" -> mds #%d\n",
+	       PFID(&body->fid1), tgt->ltd_idx);
+
+	rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it,
+			    flags, &req, cb_blocking, extra_lock_flags);
+	if (rc)
+		goto out_free_op_data;
+
+	/*
+	 * LLite needs LOOKUP lock to track dentry revocation in order to
+	 * maintain dcache consistency. Thus drop UPDATE|PERM lock here
+	 * and put LOOKUP in request.
+	 */
+	if (it->d.lustre.it_lock_mode != 0) {
+		it->d.lustre.it_remote_lock_handle =
+					it->d.lustre.it_lock_handle;
+		it->d.lustre.it_remote_lock_mode = it->d.lustre.it_lock_mode;
+	}
+
+	it->d.lustre.it_lock_handle = plock.cookie;
+	it->d.lustre.it_lock_mode = pmode;
+
+out_free_op_data:
+	OBD_FREE_PTR(op_data);
+out:
+	if (rc && pmode)
+		ldlm_lock_decref(&plock, pmode);
+
+	ptlrpc_req_finished(*reqp);
+	*reqp = req;
+	return rc;
+}
+
+/*
+ * IT_OPEN is intended to open (and create, possible) an object. Parent (pid)
+ * may be split dir.
+ */
+int lmv_intent_open(struct obd_export *exp, struct md_op_data *op_data,
+		    void *lmm, int lmmsize, struct lookup_intent *it,
+		    int flags, struct ptlrpc_request **reqp,
+		    ldlm_blocking_callback cb_blocking,
+		    __u64 extra_lock_flags)
+{
+	struct obd_device	*obd = exp->exp_obd;
+	struct lmv_obd		*lmv = &obd->u.lmv;
+	struct lmv_tgt_desc	*tgt;
+	struct mdt_body		*body;
+	int			rc;
+
+	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	/* If it is ready to open the file by FID, do not need
+	 * allocate FID at all, otherwise it will confuse MDT */
+	if ((it->it_op & IT_CREAT) &&
+	    !(it->it_flags & MDS_OPEN_BY_FID)) {
+		/*
+		 * For open with IT_CREATE and for IT_CREATE cases allocate new
+		 * fid and setup FLD for it.
+		 */
+		op_data->op_fid3 = op_data->op_fid2;
+		rc = lmv_fid_alloc(exp, &op_data->op_fid2, op_data);
+		if (rc != 0)
+			return rc;
+	}
+
+	CDEBUG(D_INODE, "OPEN_INTENT with fid1=" DFID ", fid2=" DFID ", name='%s' -> mds #%d\n",
+	       PFID(&op_data->op_fid1),
+	       PFID(&op_data->op_fid2), op_data->op_name, tgt->ltd_idx);
+
+	rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it, flags,
+			    reqp, cb_blocking, extra_lock_flags);
+	if (rc != 0)
+		return rc;
+	/*
+	 * Nothing is found, do not access body->fid1 as it is zero and thus
+	 * pointless.
+	 */
+	if ((it->d.lustre.it_disposition & DISP_LOOKUP_NEG) &&
+	    !(it->d.lustre.it_disposition & DISP_OPEN_CREATE) &&
+	    !(it->d.lustre.it_disposition & DISP_OPEN_OPEN))
+		return rc;
+
+	body = req_capsule_server_get(&(*reqp)->rq_pill, &RMF_MDT_BODY);
+	if (body == NULL)
+		return -EPROTO;
+	/*
+	 * Not cross-ref case, just get out of here.
+	 */
+	if (likely(!(body->valid & OBD_MD_MDS)))
+		return 0;
+
+	/*
+	 * Okay, MDS has returned success. Probably name has been resolved in
+	 * remote inode.
+	 */
+	rc = lmv_intent_remote(exp, lmm, lmmsize, it, &op_data->op_fid1, flags,
+			       reqp, cb_blocking, extra_lock_flags);
+	if (rc != 0) {
+		LASSERT(rc < 0);
+		/*
+		 * This is possible, that some userspace application will try to
+		 * open file as directory and we will have -ENOTDIR here. As
+		 * this is normal situation, we should not print error here,
+		 * only debug info.
+		 */
+		CDEBUG(D_INODE, "Can't handle remote %s: dir " DFID "(" DFID "):%*s: %d\n",
+		       LL_IT2STR(it), PFID(&op_data->op_fid2),
+		       PFID(&op_data->op_fid1), op_data->op_namelen,
+		       op_data->op_name, rc);
+		return rc;
+	}
+
+	return rc;
+}
+
+/*
+ * Handler for: getattr, lookup and revalidate cases.
+ */
+int lmv_intent_lookup(struct obd_export *exp, struct md_op_data *op_data,
+		      void *lmm, int lmmsize, struct lookup_intent *it,
+		      int flags, struct ptlrpc_request **reqp,
+		      ldlm_blocking_callback cb_blocking,
+		      __u64 extra_lock_flags)
+{
+	struct obd_device      *obd = exp->exp_obd;
+	struct lmv_obd	 *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc    *tgt = NULL;
+	struct mdt_body	*body;
+	int		     rc = 0;
+
+	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	if (!fid_is_sane(&op_data->op_fid2))
+		fid_zero(&op_data->op_fid2);
+
+	CDEBUG(D_INODE, "LOOKUP_INTENT with fid1="DFID", fid2="DFID
+	       ", name='%s' -> mds #%d\n", PFID(&op_data->op_fid1),
+	       PFID(&op_data->op_fid2),
+	       op_data->op_name ? op_data->op_name : "<NULL>",
+	       tgt->ltd_idx);
+
+	op_data->op_bias &= ~MDS_CROSS_REF;
+
+	rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it,
+			     flags, reqp, cb_blocking, extra_lock_flags);
+
+	if (rc < 0 || *reqp == NULL)
+		return rc;
+
+	/*
+	 * MDS has returned success. Probably name has been resolved in
+	 * remote inode. Let's check this.
+	 */
+	body = req_capsule_server_get(&(*reqp)->rq_pill, &RMF_MDT_BODY);
+	if (body == NULL)
+		return -EPROTO;
+	/* Not cross-ref case, just get out of here. */
+	if (likely(!(body->valid & OBD_MD_MDS)))
+		return 0;
+
+	rc = lmv_intent_remote(exp, lmm, lmmsize, it, NULL, flags, reqp,
+			       cb_blocking, extra_lock_flags);
+
+	return rc;
+}
+
+int lmv_intent_lock(struct obd_export *exp, struct md_op_data *op_data,
+		    void *lmm, int lmmsize, struct lookup_intent *it,
+		    int flags, struct ptlrpc_request **reqp,
+		    ldlm_blocking_callback cb_blocking,
+		    __u64 extra_lock_flags)
+{
+	struct obd_device *obd = exp->exp_obd;
+	int		rc;
+
+	LASSERT(it != NULL);
+	LASSERT(fid_is_sane(&op_data->op_fid1));
+
+	CDEBUG(D_INODE, "INTENT LOCK '%s' for '%*s' on "DFID"\n",
+	       LL_IT2STR(it), op_data->op_namelen, op_data->op_name,
+	       PFID(&op_data->op_fid1));
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	if (it->it_op & (IT_LOOKUP | IT_GETATTR | IT_LAYOUT))
+		rc = lmv_intent_lookup(exp, op_data, lmm, lmmsize, it,
+				       flags, reqp, cb_blocking,
+				       extra_lock_flags);
+	else if (it->it_op & IT_OPEN)
+		rc = lmv_intent_open(exp, op_data, lmm, lmmsize, it,
+				     flags, reqp, cb_blocking,
+				     extra_lock_flags);
+	else
+		LBUG();
+	return rc;
+}
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_internal.h b/drivers/staging/lustre/lustre/lmv/lmv_internal.h
new file mode 100644
index 000000000..852d78721
--- /dev/null
+++ b/drivers/staging/lustre/lustre/lmv/lmv_internal.h
@@ -0,0 +1,157 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#ifndef _LMV_INTERNAL_H_
+#define _LMV_INTERNAL_H_
+
+#include "../include/lustre/lustre_idl.h"
+#include "../include/obd.h"
+
+#define LMV_MAX_TGT_COUNT 128
+
+#define lmv_init_lock(lmv)   mutex_lock(&lmv->init_mutex)
+#define lmv_init_unlock(lmv) mutex_unlock(&lmv->init_mutex)
+
+#define LL_IT2STR(it)					\
+	((it) ? ldlm_it2str((it)->it_op) : "0")
+
+int lmv_check_connect(struct obd_device *obd);
+
+int lmv_intent_lock(struct obd_export *exp, struct md_op_data *op_data,
+		    void *lmm, int lmmsize, struct lookup_intent *it,
+		    int flags, struct ptlrpc_request **reqp,
+		    ldlm_blocking_callback cb_blocking,
+		    __u64 extra_lock_flags);
+
+int lmv_intent_lookup(struct obd_export *exp, struct md_op_data *op_data,
+		      void *lmm, int lmmsize, struct lookup_intent *it,
+		      int flags, struct ptlrpc_request **reqp,
+		      ldlm_blocking_callback cb_blocking,
+		      __u64 extra_lock_flags);
+
+int lmv_intent_open(struct obd_export *exp, struct md_op_data *op_data,
+		    void *lmm, int lmmsize, struct lookup_intent *it,
+		    int flags, struct ptlrpc_request **reqp,
+		    ldlm_blocking_callback cb_blocking,
+		    __u64 extra_lock_flags);
+
+int lmv_blocking_ast(struct ldlm_lock *, struct ldlm_lock_desc *,
+		     void *, int);
+int lmv_fld_lookup(struct lmv_obd *lmv, const struct lu_fid *fid, u32 *mds);
+int __lmv_fid_alloc(struct lmv_obd *lmv, struct lu_fid *fid, u32 mds);
+int lmv_fid_alloc(struct obd_export *exp, struct lu_fid *fid,
+		  struct md_op_data *op_data);
+
+static inline struct lmv_stripe_md *lmv_get_mea(struct ptlrpc_request *req)
+{
+	struct mdt_body	 *body;
+	struct lmv_stripe_md    *mea;
+
+	LASSERT(req != NULL);
+
+	body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
+
+	if (!body || !S_ISDIR(body->mode) || !body->eadatasize)
+		return NULL;
+
+	mea = req_capsule_server_sized_get(&req->rq_pill, &RMF_MDT_MD,
+					   body->eadatasize);
+	LASSERT(mea != NULL);
+
+	if (mea->mea_count == 0)
+		return NULL;
+	if (mea->mea_magic != MEA_MAGIC_LAST_CHAR &&
+		mea->mea_magic != MEA_MAGIC_ALL_CHARS &&
+		mea->mea_magic != MEA_MAGIC_HASH_SEGMENT)
+		return NULL;
+
+	return mea;
+}
+
+static inline int lmv_get_easize(struct lmv_obd *lmv)
+{
+	return sizeof(struct lmv_stripe_md) +
+		lmv->desc.ld_tgt_count *
+		sizeof(struct lu_fid);
+}
+
+static inline struct lmv_tgt_desc *
+lmv_get_target(struct lmv_obd *lmv, u32 mds)
+{
+	int count = lmv->desc.ld_tgt_count;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		if (lmv->tgts[i] == NULL)
+			continue;
+
+		if (lmv->tgts[i]->ltd_idx == mds)
+			return lmv->tgts[i];
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+static inline struct lmv_tgt_desc *
+lmv_find_target(struct lmv_obd *lmv, const struct lu_fid *fid)
+{
+	u32 mds = 0;
+	int rc;
+
+	if (lmv->desc.ld_tgt_count > 1) {
+		rc = lmv_fld_lookup(lmv, fid, &mds);
+		if (rc)
+			return ERR_PTR(rc);
+	}
+
+	return lmv_get_target(lmv, mds);
+}
+
+struct lmv_tgt_desc
+*lmv_locate_mds(struct lmv_obd *lmv, struct md_op_data *op_data,
+		struct lu_fid *fid);
+/* lproc_lmv.c */
+#if defined(CONFIG_PROC_FS)
+void lprocfs_lmv_init_vars(struct lprocfs_static_vars *lvars);
+#else
+static inline void lprocfs_lmv_init_vars(struct lprocfs_static_vars *lvars)
+{
+	memset(lvars, 0, sizeof(*lvars));
+}
+#endif
+extern struct file_operations lmv_proc_target_fops;
+
+#endif
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_obd.c b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
new file mode 100644
index 000000000..b9459faf8
--- /dev/null
+++ b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
@@ -0,0 +1,2892 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#define DEBUG_SUBSYSTEM S_LMV
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/mm.h>
+#include <asm/div64.h>
+#include <linux/seq_file.h>
+#include <linux/namei.h>
+#include <linux/uaccess.h>
+
+#include "../include/lustre/lustre_idl.h"
+#include "../include/obd_support.h"
+#include "../include/lustre_lib.h"
+#include "../include/lustre_net.h"
+#include "../include/obd_class.h"
+#include "../include/lprocfs_status.h"
+#include "../include/lustre_lite.h"
+#include "../include/lustre_fid.h"
+#include "lmv_internal.h"
+
+static void lmv_activate_target(struct lmv_obd *lmv,
+				struct lmv_tgt_desc *tgt,
+				int activate)
+{
+	if (tgt->ltd_active == activate)
+		return;
+
+	tgt->ltd_active = activate;
+	lmv->desc.ld_active_tgt_count += (activate ? 1 : -1);
+}
+
+/**
+ * Error codes:
+ *
+ *  -EINVAL  : UUID can't be found in the LMV's target list
+ *  -ENOTCONN: The UUID is found, but the target connection is bad (!)
+ *  -EBADF   : The UUID is found, but the OBD of the wrong type (!)
+ */
+static int lmv_set_mdc_active(struct lmv_obd *lmv, struct obd_uuid *uuid,
+			      int activate)
+{
+	struct lmv_tgt_desc    *uninitialized_var(tgt);
+	struct obd_device      *obd;
+	int		     i;
+	int		     rc = 0;
+
+	CDEBUG(D_INFO, "Searching in lmv %p for uuid %s (activate=%d)\n",
+	       lmv, uuid->uuid, activate);
+
+	spin_lock(&lmv->lmv_lock);
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[i];
+		if (tgt == NULL || tgt->ltd_exp == NULL)
+			continue;
+
+		CDEBUG(D_INFO, "Target idx %d is %s conn %#llx\n", i,
+		       tgt->ltd_uuid.uuid, tgt->ltd_exp->exp_handle.h_cookie);
+
+		if (obd_uuid_equals(uuid, &tgt->ltd_uuid))
+			break;
+	}
+
+	if (i == lmv->desc.ld_tgt_count) {
+		rc = -EINVAL;
+		goto out_lmv_lock;
+	}
+
+	obd = class_exp2obd(tgt->ltd_exp);
+	if (obd == NULL) {
+		rc = -ENOTCONN;
+		goto out_lmv_lock;
+	}
+
+	CDEBUG(D_INFO, "Found OBD %s=%s device %d (%p) type %s at LMV idx %d\n",
+	       obd->obd_name, obd->obd_uuid.uuid, obd->obd_minor, obd,
+	       obd->obd_type->typ_name, i);
+	LASSERT(strcmp(obd->obd_type->typ_name, LUSTRE_MDC_NAME) == 0);
+
+	if (tgt->ltd_active == activate) {
+		CDEBUG(D_INFO, "OBD %p already %sactive!\n", obd,
+		       activate ? "" : "in");
+		goto out_lmv_lock;
+	}
+
+	CDEBUG(D_INFO, "Marking OBD %p %sactive\n", obd,
+	       activate ? "" : "in");
+	lmv_activate_target(lmv, tgt, activate);
+
+ out_lmv_lock:
+	spin_unlock(&lmv->lmv_lock);
+	return rc;
+}
+
+static struct obd_uuid *lmv_get_uuid(struct obd_export *exp)
+{
+	struct lmv_obd *lmv = &exp->exp_obd->u.lmv;
+
+	return obd_get_uuid(lmv->tgts[0]->ltd_exp);
+}
+
+static int lmv_notify(struct obd_device *obd, struct obd_device *watched,
+		      enum obd_notify_event ev, void *data)
+{
+	struct obd_connect_data *conn_data;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct obd_uuid	 *uuid;
+	int		      rc = 0;
+
+	if (strcmp(watched->obd_type->typ_name, LUSTRE_MDC_NAME)) {
+		CERROR("unexpected notification of %s %s!\n",
+		       watched->obd_type->typ_name,
+		       watched->obd_name);
+		return -EINVAL;
+	}
+
+	uuid = &watched->u.cli.cl_target_uuid;
+	if (ev == OBD_NOTIFY_ACTIVE || ev == OBD_NOTIFY_INACTIVE) {
+		/*
+		 * Set MDC as active before notifying the observer, so the
+		 * observer can use the MDC normally.
+		 */
+		rc = lmv_set_mdc_active(lmv, uuid,
+					ev == OBD_NOTIFY_ACTIVE);
+		if (rc) {
+			CERROR("%sactivation of %s failed: %d\n",
+			       ev == OBD_NOTIFY_ACTIVE ? "" : "de",
+			       uuid->uuid, rc);
+			return rc;
+		}
+	} else if (ev == OBD_NOTIFY_OCD) {
+		conn_data = &watched->u.cli.cl_import->imp_connect_data;
+		/*
+		 * XXX: Make sure that ocd_connect_flags from all targets are
+		 * the same. Otherwise one of MDTs runs wrong version or
+		 * something like this.  --umka
+		 */
+		obd->obd_self_export->exp_connect_data = *conn_data;
+	}
+#if 0
+	else if (ev == OBD_NOTIFY_DISCON) {
+		/*
+		 * For disconnect event, flush fld cache for failout MDS case.
+		 */
+		fld_client_flush(&lmv->lmv_fld);
+	}
+#endif
+	/*
+	 * Pass the notification up the chain.
+	 */
+	if (obd->obd_observer)
+		rc = obd_notify(obd->obd_observer, watched, ev, data);
+
+	return rc;
+}
+
+/**
+ * This is fake connect function. Its purpose is to initialize lmv and say
+ * caller that everything is okay. Real connection will be performed later.
+ */
+static int lmv_connect(const struct lu_env *env,
+		       struct obd_export **exp, struct obd_device *obd,
+		       struct obd_uuid *cluuid, struct obd_connect_data *data,
+		       void *localdata)
+{
+	struct proc_dir_entry *lmv_proc_dir;
+	struct lmv_obd	*lmv = &obd->u.lmv;
+	struct lustre_handle  conn = { 0 };
+	int		    rc = 0;
+
+	/*
+	 * We don't want to actually do the underlying connections more than
+	 * once, so keep track.
+	 */
+	lmv->refcount++;
+	if (lmv->refcount > 1) {
+		*exp = NULL;
+		return 0;
+	}
+
+	rc = class_connect(&conn, obd, cluuid);
+	if (rc) {
+		CERROR("class_connection() returned %d\n", rc);
+		return rc;
+	}
+
+	*exp = class_conn2export(&conn);
+	class_export_get(*exp);
+
+	lmv->exp = *exp;
+	lmv->connected = 0;
+	lmv->cluuid = *cluuid;
+
+	if (data)
+		lmv->conn_data = *data;
+
+	if (obd->obd_proc_private != NULL) {
+		lmv_proc_dir = obd->obd_proc_private;
+	} else {
+		lmv_proc_dir = lprocfs_register("target_obds", obd->obd_proc_entry,
+						NULL, NULL);
+		if (IS_ERR(lmv_proc_dir)) {
+			CERROR("could not register /proc/fs/lustre/%s/%s/target_obds.",
+			       obd->obd_type->typ_name, obd->obd_name);
+			lmv_proc_dir = NULL;
+		}
+		obd->obd_proc_private = lmv_proc_dir;
+	}
+
+	/*
+	 * All real clients should perform actual connection right away, because
+	 * it is possible, that LMV will not have opportunity to connect targets
+	 * and MDC stuff will be called directly, for instance while reading
+	 * ../mdc/../kbytesfree procfs file, etc.
+	 */
+	if (data->ocd_connect_flags & OBD_CONNECT_REAL)
+		rc = lmv_check_connect(obd);
+
+	if (rc && lmv_proc_dir) {
+		lprocfs_remove(&lmv_proc_dir);
+		obd->obd_proc_private = NULL;
+	}
+
+	return rc;
+}
+
+static void lmv_set_timeouts(struct obd_device *obd)
+{
+	struct lmv_tgt_desc   *tgt;
+	struct lmv_obd	*lmv;
+	int		    i;
+
+	lmv = &obd->u.lmv;
+	if (lmv->server_timeout == 0)
+		return;
+
+	if (lmv->connected == 0)
+		return;
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[i];
+		if (tgt == NULL || tgt->ltd_exp == NULL || tgt->ltd_active == 0)
+			continue;
+
+		obd_set_info_async(NULL, tgt->ltd_exp, sizeof(KEY_INTERMDS),
+				   KEY_INTERMDS, 0, NULL, NULL);
+	}
+}
+
+static int lmv_init_ea_size(struct obd_export *exp, int easize,
+			    int def_easize, int cookiesize, int def_cookiesize)
+{
+	struct obd_device   *obd = exp->exp_obd;
+	struct lmv_obd      *lmv = &obd->u.lmv;
+	int		  i;
+	int		  rc = 0;
+	int		  change = 0;
+
+	if (lmv->max_easize < easize) {
+		lmv->max_easize = easize;
+		change = 1;
+	}
+	if (lmv->max_def_easize < def_easize) {
+		lmv->max_def_easize = def_easize;
+		change = 1;
+	}
+	if (lmv->max_cookiesize < cookiesize) {
+		lmv->max_cookiesize = cookiesize;
+		change = 1;
+	}
+	if (lmv->max_def_cookiesize < def_cookiesize) {
+		lmv->max_def_cookiesize = def_cookiesize;
+		change = 1;
+	}
+	if (change == 0)
+		return 0;
+
+	if (lmv->connected == 0)
+		return 0;
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL ||
+		    lmv->tgts[i]->ltd_exp == NULL ||
+		    lmv->tgts[i]->ltd_active == 0) {
+			CWARN("%s: NULL export for %d\n", obd->obd_name, i);
+			continue;
+		}
+
+		rc = md_init_ea_size(lmv->tgts[i]->ltd_exp, easize, def_easize,
+				     cookiesize, def_cookiesize);
+		if (rc) {
+			CERROR("%s: obd_init_ea_size() failed on MDT target %d: rc = %d.\n",
+			       obd->obd_name, i, rc);
+			break;
+		}
+	}
+	return rc;
+}
+
+#define MAX_STRING_SIZE 128
+
+static int lmv_connect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
+{
+	struct proc_dir_entry   *lmv_proc_dir;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct obd_uuid	 *cluuid = &lmv->cluuid;
+	struct obd_uuid	  lmv_mdc_uuid = { "LMV_MDC_UUID" };
+	struct obd_device       *mdc_obd;
+	struct obd_export       *mdc_exp;
+	struct lu_fld_target     target;
+	int		      rc;
+
+	mdc_obd = class_find_client_obd(&tgt->ltd_uuid, LUSTRE_MDC_NAME,
+					&obd->obd_uuid);
+	if (!mdc_obd) {
+		CERROR("target %s not attached\n", tgt->ltd_uuid.uuid);
+		return -EINVAL;
+	}
+
+	CDEBUG(D_CONFIG, "connect to %s(%s) - %s, %s FOR %s\n",
+		mdc_obd->obd_name, mdc_obd->obd_uuid.uuid,
+		tgt->ltd_uuid.uuid, obd->obd_uuid.uuid,
+		cluuid->uuid);
+
+	if (!mdc_obd->obd_set_up) {
+		CERROR("target %s is not set up\n", tgt->ltd_uuid.uuid);
+		return -EINVAL;
+	}
+
+	rc = obd_connect(NULL, &mdc_exp, mdc_obd, &lmv_mdc_uuid,
+			 &lmv->conn_data, NULL);
+	if (rc) {
+		CERROR("target %s connect error %d\n", tgt->ltd_uuid.uuid, rc);
+		return rc;
+	}
+
+	/*
+	 * Init fid sequence client for this mdc and add new fld target.
+	 */
+	rc = obd_fid_init(mdc_obd, mdc_exp, LUSTRE_SEQ_METADATA);
+	if (rc)
+		return rc;
+
+	target.ft_srv = NULL;
+	target.ft_exp = mdc_exp;
+	target.ft_idx = tgt->ltd_idx;
+
+	fld_client_add_target(&lmv->lmv_fld, &target);
+
+	rc = obd_register_observer(mdc_obd, obd);
+	if (rc) {
+		obd_disconnect(mdc_exp);
+		CERROR("target %s register_observer error %d\n",
+		       tgt->ltd_uuid.uuid, rc);
+		return rc;
+	}
+
+	if (obd->obd_observer) {
+		/*
+		 * Tell the observer about the new target.
+		 */
+		rc = obd_notify(obd->obd_observer, mdc_exp->exp_obd,
+				OBD_NOTIFY_ACTIVE,
+				(void *)(tgt - lmv->tgts[0]));
+		if (rc) {
+			obd_disconnect(mdc_exp);
+			return rc;
+		}
+	}
+
+	tgt->ltd_active = 1;
+	tgt->ltd_exp = mdc_exp;
+	lmv->desc.ld_active_tgt_count++;
+
+	md_init_ea_size(tgt->ltd_exp, lmv->max_easize, lmv->max_def_easize,
+			lmv->max_cookiesize, lmv->max_def_cookiesize);
+
+	CDEBUG(D_CONFIG, "Connected to %s(%s) successfully (%d)\n",
+		mdc_obd->obd_name, mdc_obd->obd_uuid.uuid,
+		atomic_read(&obd->obd_refcount));
+
+	lmv_proc_dir = obd->obd_proc_private;
+	if (lmv_proc_dir) {
+		struct proc_dir_entry *mdc_symlink;
+
+		LASSERT(mdc_obd->obd_type != NULL);
+		LASSERT(mdc_obd->obd_type->typ_name != NULL);
+		mdc_symlink = lprocfs_add_symlink(mdc_obd->obd_name,
+						  lmv_proc_dir,
+						  "../../../%s/%s",
+						  mdc_obd->obd_type->typ_name,
+						  mdc_obd->obd_name);
+		if (mdc_symlink == NULL) {
+			CERROR("Could not register LMV target /proc/fs/lustre/%s/%s/target_obds/%s.",
+			       obd->obd_type->typ_name, obd->obd_name,
+			       mdc_obd->obd_name);
+			lprocfs_remove(&lmv_proc_dir);
+			obd->obd_proc_private = NULL;
+		}
+	}
+	return 0;
+}
+
+static void lmv_del_target(struct lmv_obd *lmv, int index)
+{
+	if (lmv->tgts[index] == NULL)
+		return;
+
+	OBD_FREE_PTR(lmv->tgts[index]);
+	lmv->tgts[index] = NULL;
+	return;
+}
+
+static int lmv_add_target(struct obd_device *obd, struct obd_uuid *uuidp,
+			   __u32 index, int gen)
+{
+	struct lmv_obd      *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc *tgt;
+	int		  rc = 0;
+
+	CDEBUG(D_CONFIG, "Target uuid: %s. index %d\n", uuidp->uuid, index);
+
+	lmv_init_lock(lmv);
+
+	if (lmv->desc.ld_tgt_count == 0) {
+		struct obd_device *mdc_obd;
+
+		mdc_obd = class_find_client_obd(uuidp, LUSTRE_MDC_NAME,
+						&obd->obd_uuid);
+		if (!mdc_obd) {
+			lmv_init_unlock(lmv);
+			CERROR("%s: Target %s not attached: rc = %d\n",
+			       obd->obd_name, uuidp->uuid, -EINVAL);
+			return -EINVAL;
+		}
+	}
+
+	if ((index < lmv->tgts_size) && (lmv->tgts[index] != NULL)) {
+		tgt = lmv->tgts[index];
+		CERROR("%s: UUID %s already assigned at LOV target index %d: rc = %d\n",
+		       obd->obd_name,
+		       obd_uuid2str(&tgt->ltd_uuid), index, -EEXIST);
+		lmv_init_unlock(lmv);
+		return -EEXIST;
+	}
+
+	if (index >= lmv->tgts_size) {
+		/* We need to reallocate the lmv target array. */
+		struct lmv_tgt_desc **newtgts, **old = NULL;
+		__u32 newsize = 1;
+		__u32 oldsize = 0;
+
+		while (newsize < index + 1)
+			newsize <<= 1;
+		OBD_ALLOC(newtgts, sizeof(*newtgts) * newsize);
+		if (newtgts == NULL) {
+			lmv_init_unlock(lmv);
+			return -ENOMEM;
+		}
+
+		if (lmv->tgts_size) {
+			memcpy(newtgts, lmv->tgts,
+			       sizeof(*newtgts) * lmv->tgts_size);
+			old = lmv->tgts;
+			oldsize = lmv->tgts_size;
+		}
+
+		lmv->tgts = newtgts;
+		lmv->tgts_size = newsize;
+		smp_rmb();
+		if (old)
+			OBD_FREE(old, sizeof(*old) * oldsize);
+
+		CDEBUG(D_CONFIG, "tgts: %p size: %d\n", lmv->tgts,
+		       lmv->tgts_size);
+	}
+
+	OBD_ALLOC_PTR(tgt);
+	if (!tgt) {
+		lmv_init_unlock(lmv);
+		return -ENOMEM;
+	}
+
+	mutex_init(&tgt->ltd_fid_mutex);
+	tgt->ltd_idx = index;
+	tgt->ltd_uuid = *uuidp;
+	tgt->ltd_active = 0;
+	lmv->tgts[index] = tgt;
+	if (index >= lmv->desc.ld_tgt_count)
+		lmv->desc.ld_tgt_count = index + 1;
+
+	if (lmv->connected) {
+		rc = lmv_connect_mdc(obd, tgt);
+		if (rc) {
+			spin_lock(&lmv->lmv_lock);
+			lmv->desc.ld_tgt_count--;
+			memset(tgt, 0, sizeof(*tgt));
+			spin_unlock(&lmv->lmv_lock);
+		} else {
+			int easize = sizeof(struct lmv_stripe_md) +
+				lmv->desc.ld_tgt_count * sizeof(struct lu_fid);
+			lmv_init_ea_size(obd->obd_self_export, easize, 0, 0, 0);
+		}
+	}
+
+	lmv_init_unlock(lmv);
+	return rc;
+}
+
+int lmv_check_connect(struct obd_device *obd)
+{
+	struct lmv_obd       *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc  *tgt;
+	int		   i;
+	int		   rc;
+	int		   easize;
+
+	if (lmv->connected)
+		return 0;
+
+	lmv_init_lock(lmv);
+	if (lmv->connected) {
+		lmv_init_unlock(lmv);
+		return 0;
+	}
+
+	if (lmv->desc.ld_tgt_count == 0) {
+		lmv_init_unlock(lmv);
+		CERROR("%s: no targets configured.\n", obd->obd_name);
+		return -EINVAL;
+	}
+
+	CDEBUG(D_CONFIG, "Time to connect %s to %s\n",
+	       lmv->cluuid.uuid, obd->obd_name);
+
+	LASSERT(lmv->tgts != NULL);
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[i];
+		if (tgt == NULL)
+			continue;
+		rc = lmv_connect_mdc(obd, tgt);
+		if (rc)
+			goto out_disc;
+	}
+
+	lmv_set_timeouts(obd);
+	class_export_put(lmv->exp);
+	lmv->connected = 1;
+	easize = lmv_get_easize(lmv);
+	lmv_init_ea_size(obd->obd_self_export, easize, 0, 0, 0);
+	lmv_init_unlock(lmv);
+	return 0;
+
+ out_disc:
+	while (i-- > 0) {
+		int rc2;
+		tgt = lmv->tgts[i];
+		if (tgt == NULL)
+			continue;
+		tgt->ltd_active = 0;
+		if (tgt->ltd_exp) {
+			--lmv->desc.ld_active_tgt_count;
+			rc2 = obd_disconnect(tgt->ltd_exp);
+			if (rc2) {
+				CERROR("LMV target %s disconnect on MDC idx %d: error %d\n",
+				       tgt->ltd_uuid.uuid, i, rc2);
+			}
+		}
+	}
+	class_disconnect(lmv->exp);
+	lmv_init_unlock(lmv);
+	return rc;
+}
+
+static int lmv_disconnect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
+{
+	struct proc_dir_entry  *lmv_proc_dir;
+	struct lmv_obd	 *lmv = &obd->u.lmv;
+	struct obd_device      *mdc_obd;
+	int		     rc;
+
+	LASSERT(tgt != NULL);
+	LASSERT(obd != NULL);
+
+	mdc_obd = class_exp2obd(tgt->ltd_exp);
+
+	if (mdc_obd) {
+		mdc_obd->obd_force = obd->obd_force;
+		mdc_obd->obd_fail = obd->obd_fail;
+		mdc_obd->obd_no_recov = obd->obd_no_recov;
+	}
+
+	lmv_proc_dir = obd->obd_proc_private;
+	if (lmv_proc_dir)
+		lprocfs_remove_proc_entry(mdc_obd->obd_name, lmv_proc_dir);
+
+	rc = obd_fid_fini(tgt->ltd_exp->exp_obd);
+	if (rc)
+		CERROR("Can't finalize fids factory\n");
+
+	CDEBUG(D_INFO, "Disconnected from %s(%s) successfully\n",
+	       tgt->ltd_exp->exp_obd->obd_name,
+	       tgt->ltd_exp->exp_obd->obd_uuid.uuid);
+
+	obd_register_observer(tgt->ltd_exp->exp_obd, NULL);
+	rc = obd_disconnect(tgt->ltd_exp);
+	if (rc) {
+		if (tgt->ltd_active) {
+			CERROR("Target %s disconnect error %d\n",
+			       tgt->ltd_uuid.uuid, rc);
+		}
+	}
+
+	lmv_activate_target(lmv, tgt, 0);
+	tgt->ltd_exp = NULL;
+	return 0;
+}
+
+static int lmv_disconnect(struct obd_export *exp)
+{
+	struct obd_device     *obd = class_exp2obd(exp);
+	struct lmv_obd	*lmv = &obd->u.lmv;
+	int		    rc;
+	int		    i;
+
+	if (!lmv->tgts)
+		goto out_local;
+
+	/*
+	 * Only disconnect the underlying layers on the final disconnect.
+	 */
+	lmv->refcount--;
+	if (lmv->refcount != 0)
+		goto out_local;
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
+			continue;
+
+		lmv_disconnect_mdc(obd, lmv->tgts[i]);
+	}
+
+	if (obd->obd_proc_private)
+		lprocfs_remove((struct proc_dir_entry **)&obd->obd_proc_private);
+	else
+		CERROR("/proc/fs/lustre/%s/%s/target_obds missing\n",
+		       obd->obd_type->typ_name, obd->obd_name);
+
+out_local:
+	/*
+	 * This is the case when no real connection is established by
+	 * lmv_check_connect().
+	 */
+	if (!lmv->connected)
+		class_export_put(exp);
+	rc = class_disconnect(exp);
+	if (lmv->refcount == 0)
+		lmv->connected = 0;
+	return rc;
+}
+
+static int lmv_fid2path(struct obd_export *exp, int len, void *karg, void *uarg)
+{
+	struct obd_device	*obddev = class_exp2obd(exp);
+	struct lmv_obd		*lmv = &obddev->u.lmv;
+	struct getinfo_fid2path *gf;
+	struct lmv_tgt_desc     *tgt;
+	struct getinfo_fid2path *remote_gf = NULL;
+	int			remote_gf_size = 0;
+	int			rc;
+
+	gf = (struct getinfo_fid2path *)karg;
+	tgt = lmv_find_target(lmv, &gf->gf_fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+repeat_fid2path:
+	rc = obd_iocontrol(OBD_IOC_FID2PATH, tgt->ltd_exp, len, gf, uarg);
+	if (rc != 0 && rc != -EREMOTE)
+		goto out_fid2path;
+
+	/* If remote_gf != NULL, it means just building the
+	 * path on the remote MDT, copy this path segment to gf */
+	if (remote_gf != NULL) {
+		struct getinfo_fid2path *ori_gf;
+		char *ptr;
+
+		ori_gf = (struct getinfo_fid2path *)karg;
+		if (strlen(ori_gf->gf_path) +
+		    strlen(gf->gf_path) > ori_gf->gf_pathlen) {
+			rc = -EOVERFLOW;
+			goto out_fid2path;
+		}
+
+		ptr = ori_gf->gf_path;
+
+		memmove(ptr + strlen(gf->gf_path) + 1, ptr,
+			strlen(ori_gf->gf_path));
+
+		strncpy(ptr, gf->gf_path, strlen(gf->gf_path));
+		ptr += strlen(gf->gf_path);
+		*ptr = '/';
+	}
+
+	CDEBUG(D_INFO, "%s: get path %s "DFID" rec: %llu ln: %u\n",
+	       tgt->ltd_exp->exp_obd->obd_name,
+	       gf->gf_path, PFID(&gf->gf_fid), gf->gf_recno,
+	       gf->gf_linkno);
+
+	if (rc == 0)
+		goto out_fid2path;
+
+	/* sigh, has to go to another MDT to do path building further */
+	if (remote_gf == NULL) {
+		remote_gf_size = sizeof(*remote_gf) + PATH_MAX;
+		OBD_ALLOC(remote_gf, remote_gf_size);
+		if (remote_gf == NULL) {
+			rc = -ENOMEM;
+			goto out_fid2path;
+		}
+		remote_gf->gf_pathlen = PATH_MAX;
+	}
+
+	if (!fid_is_sane(&gf->gf_fid)) {
+		CERROR("%s: invalid FID "DFID": rc = %d\n",
+		       tgt->ltd_exp->exp_obd->obd_name,
+		       PFID(&gf->gf_fid), -EINVAL);
+		rc = -EINVAL;
+		goto out_fid2path;
+	}
+
+	tgt = lmv_find_target(lmv, &gf->gf_fid);
+	if (IS_ERR(tgt)) {
+		rc = -EINVAL;
+		goto out_fid2path;
+	}
+
+	remote_gf->gf_fid = gf->gf_fid;
+	remote_gf->gf_recno = -1;
+	remote_gf->gf_linkno = -1;
+	memset(remote_gf->gf_path, 0, remote_gf->gf_pathlen);
+	gf = remote_gf;
+	goto repeat_fid2path;
+
+out_fid2path:
+	if (remote_gf != NULL)
+		OBD_FREE(remote_gf, remote_gf_size);
+	return rc;
+}
+
+static int lmv_hsm_req_count(struct lmv_obd *lmv,
+			     const struct hsm_user_request *hur,
+			     const struct lmv_tgt_desc *tgt_mds)
+{
+	int			i, nr = 0;
+	struct lmv_tgt_desc    *curr_tgt;
+
+	/* count how many requests must be sent to the given target */
+	for (i = 0; i < hur->hur_request.hr_itemcount; i++) {
+		curr_tgt = lmv_find_target(lmv, &hur->hur_user_item[i].hui_fid);
+		if (obd_uuid_equals(&curr_tgt->ltd_uuid, &tgt_mds->ltd_uuid))
+			nr++;
+	}
+	return nr;
+}
+
+static void lmv_hsm_req_build(struct lmv_obd *lmv,
+			      struct hsm_user_request *hur_in,
+			      const struct lmv_tgt_desc *tgt_mds,
+			      struct hsm_user_request *hur_out)
+{
+	int			i, nr_out;
+	struct lmv_tgt_desc    *curr_tgt;
+
+	/* build the hsm_user_request for the given target */
+	hur_out->hur_request = hur_in->hur_request;
+	nr_out = 0;
+	for (i = 0; i < hur_in->hur_request.hr_itemcount; i++) {
+		curr_tgt = lmv_find_target(lmv,
+					&hur_in->hur_user_item[i].hui_fid);
+		if (obd_uuid_equals(&curr_tgt->ltd_uuid, &tgt_mds->ltd_uuid)) {
+			hur_out->hur_user_item[nr_out] =
+				hur_in->hur_user_item[i];
+			nr_out++;
+		}
+	}
+	hur_out->hur_request.hr_itemcount = nr_out;
+	memcpy(hur_data(hur_out), hur_data(hur_in),
+	       hur_in->hur_request.hr_data_len);
+}
+
+static int lmv_hsm_ct_unregister(struct lmv_obd *lmv, unsigned int cmd, int len,
+				 struct lustre_kernelcomm *lk, void *uarg)
+{
+	int	i, rc = 0;
+
+	/* unregister request (call from llapi_hsm_copytool_fini) */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		/* best effort: try to clean as much as possible
+		 * (continue on error) */
+		obd_iocontrol(cmd, lmv->tgts[i]->ltd_exp, len, lk, uarg);
+	}
+
+	/* Whatever the result, remove copytool from kuc groups.
+	 * Unreached coordinators will get EPIPE on next requests
+	 * and will unregister automatically.
+	 */
+	rc = libcfs_kkuc_group_rem(lk->lk_uid, lk->lk_group);
+	return rc;
+}
+
+static int lmv_hsm_ct_register(struct lmv_obd *lmv, unsigned int cmd, int len,
+			       struct lustre_kernelcomm *lk, void *uarg)
+{
+	struct file	*filp;
+	int		 i, j, err;
+	int		 rc = 0;
+	bool		 any_set = false;
+
+	/* All or nothing: try to register to all MDS.
+	 * In case of failure, unregister from previous MDS,
+	 * except if it because of inactive target. */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		err = obd_iocontrol(cmd, lmv->tgts[i]->ltd_exp,
+				   len, lk, uarg);
+		if (err) {
+			if (lmv->tgts[i]->ltd_active) {
+				/* permanent error */
+				CERROR("error: iocontrol MDC %s on MDTidx %d cmd %x: err = %d\n",
+				       lmv->tgts[i]->ltd_uuid.uuid,
+				       i, cmd, err);
+				rc = err;
+				lk->lk_flags |= LK_FLG_STOP;
+				/* unregister from previous MDS */
+				for (j = 0; j < i; j++)
+					obd_iocontrol(cmd,
+						  lmv->tgts[j]->ltd_exp,
+						  len, lk, uarg);
+				return rc;
+			}
+			/* else: transient error.
+			 * kuc will register to the missing MDT
+			 * when it is back */
+		} else {
+			any_set = true;
+		}
+	}
+
+	if (!any_set)
+		/* no registration done: return error */
+		return -ENOTCONN;
+
+	/* at least one registration done, with no failure */
+	filp = fget(lk->lk_wfd);
+	if (filp == NULL) {
+		return -EBADF;
+	}
+	rc = libcfs_kkuc_group_add(filp, lk->lk_uid, lk->lk_group, lk->lk_data);
+	if (rc != 0 && filp != NULL)
+		fput(filp);
+	return rc;
+}
+
+
+
+
+static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
+			 int len, void *karg, void *uarg)
+{
+	struct obd_device    *obddev = class_exp2obd(exp);
+	struct lmv_obd       *lmv = &obddev->u.lmv;
+	int		   i = 0;
+	int		   rc = 0;
+	int		   set = 0;
+	int		   count = lmv->desc.ld_tgt_count;
+
+	if (count == 0)
+		return -ENOTTY;
+
+	switch (cmd) {
+	case IOC_OBD_STATFS: {
+		struct obd_ioctl_data *data = karg;
+		struct obd_device *mdc_obd;
+		struct obd_statfs stat_buf = {0};
+		__u32 index;
+
+		memcpy(&index, data->ioc_inlbuf2, sizeof(__u32));
+		if (index >= count)
+			return -ENODEV;
+
+		if (lmv->tgts[index] == NULL ||
+		    lmv->tgts[index]->ltd_active == 0)
+			return -ENODATA;
+
+		mdc_obd = class_exp2obd(lmv->tgts[index]->ltd_exp);
+		if (!mdc_obd)
+			return -EINVAL;
+
+		/* copy UUID */
+		if (copy_to_user(data->ioc_pbuf2, obd2cli_tgt(mdc_obd),
+				     min((int) data->ioc_plen2,
+					 (int) sizeof(struct obd_uuid))))
+			return -EFAULT;
+
+		rc = obd_statfs(NULL, lmv->tgts[index]->ltd_exp, &stat_buf,
+				cfs_time_shift_64(-OBD_STATFS_CACHE_SECONDS),
+				0);
+		if (rc)
+			return rc;
+		if (copy_to_user(data->ioc_pbuf1, &stat_buf,
+				     min((int) data->ioc_plen1,
+					 (int) sizeof(stat_buf))))
+			return -EFAULT;
+		break;
+	}
+	case OBD_IOC_QUOTACTL: {
+		struct if_quotactl *qctl = karg;
+		struct lmv_tgt_desc *tgt = NULL;
+		struct obd_quotactl *oqctl;
+
+		if (qctl->qc_valid == QC_MDTIDX) {
+			if (qctl->qc_idx < 0 || count <= qctl->qc_idx)
+				return -EINVAL;
+
+			tgt = lmv->tgts[qctl->qc_idx];
+			if (tgt == NULL || tgt->ltd_exp == NULL)
+				return -EINVAL;
+		} else if (qctl->qc_valid == QC_UUID) {
+			for (i = 0; i < count; i++) {
+				tgt = lmv->tgts[i];
+				if (tgt == NULL)
+					continue;
+				if (!obd_uuid_equals(&tgt->ltd_uuid,
+						     &qctl->obd_uuid))
+					continue;
+
+				if (tgt->ltd_exp == NULL)
+					return -EINVAL;
+
+				break;
+			}
+		} else {
+			return -EINVAL;
+		}
+
+		if (i >= count)
+			return -EAGAIN;
+
+		LASSERT(tgt && tgt->ltd_exp);
+		OBD_ALLOC_PTR(oqctl);
+		if (!oqctl)
+			return -ENOMEM;
+
+		QCTL_COPY(oqctl, qctl);
+		rc = obd_quotactl(tgt->ltd_exp, oqctl);
+		if (rc == 0) {
+			QCTL_COPY(qctl, oqctl);
+			qctl->qc_valid = QC_MDTIDX;
+			qctl->obd_uuid = tgt->ltd_uuid;
+		}
+		OBD_FREE_PTR(oqctl);
+		break;
+	}
+	case OBD_IOC_CHANGELOG_SEND:
+	case OBD_IOC_CHANGELOG_CLEAR: {
+		struct ioc_changelog *icc = karg;
+
+		if (icc->icc_mdtindex >= count)
+			return -ENODEV;
+
+		if (lmv->tgts[icc->icc_mdtindex] == NULL ||
+		    lmv->tgts[icc->icc_mdtindex]->ltd_exp == NULL ||
+		    lmv->tgts[icc->icc_mdtindex]->ltd_active == 0)
+			return -ENODEV;
+		rc = obd_iocontrol(cmd, lmv->tgts[icc->icc_mdtindex]->ltd_exp,
+				   sizeof(*icc), icc, NULL);
+		break;
+	}
+	case LL_IOC_GET_CONNECT_FLAGS: {
+		if (lmv->tgts[0] == NULL)
+			return -ENODATA;
+		rc = obd_iocontrol(cmd, lmv->tgts[0]->ltd_exp, len, karg, uarg);
+		break;
+	}
+	case OBD_IOC_FID2PATH: {
+		rc = lmv_fid2path(exp, len, karg, uarg);
+		break;
+	}
+	case LL_IOC_HSM_STATE_GET:
+	case LL_IOC_HSM_STATE_SET:
+	case LL_IOC_HSM_ACTION: {
+		struct md_op_data	*op_data = karg;
+		struct lmv_tgt_desc	*tgt;
+
+		tgt = lmv_find_target(lmv, &op_data->op_fid1);
+		if (IS_ERR(tgt))
+				return PTR_ERR(tgt);
+
+		if (tgt->ltd_exp == NULL)
+				return -EINVAL;
+
+		rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
+		break;
+	}
+	case LL_IOC_HSM_PROGRESS: {
+		const struct hsm_progress_kernel *hpk = karg;
+		struct lmv_tgt_desc	*tgt;
+
+		tgt = lmv_find_target(lmv, &hpk->hpk_fid);
+		if (IS_ERR(tgt))
+			return PTR_ERR(tgt);
+		rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
+		break;
+	}
+	case LL_IOC_HSM_REQUEST: {
+		struct hsm_user_request *hur = karg;
+		struct lmv_tgt_desc	*tgt;
+		unsigned int reqcount = hur->hur_request.hr_itemcount;
+
+		if (reqcount == 0)
+			return 0;
+
+		/* if the request is about a single fid
+		 * or if there is a single MDS, no need to split
+		 * the request. */
+		if (reqcount == 1 || count == 1) {
+			tgt = lmv_find_target(lmv,
+					      &hur->hur_user_item[0].hui_fid);
+			if (IS_ERR(tgt))
+				return PTR_ERR(tgt);
+			rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
+		} else {
+			/* split fid list to their respective MDS */
+			for (i = 0; i < count; i++) {
+				unsigned int		nr, reqlen;
+				int			rc1;
+				struct hsm_user_request *req;
+
+				nr = lmv_hsm_req_count(lmv, hur, lmv->tgts[i]);
+				if (nr == 0) /* nothing for this MDS */
+					continue;
+
+				/* build a request with fids for this MDS */
+				reqlen = offsetof(typeof(*hur),
+						  hur_user_item[nr])
+					 + hur->hur_request.hr_data_len;
+				OBD_ALLOC_LARGE(req, reqlen);
+				if (req == NULL)
+					return -ENOMEM;
+
+				lmv_hsm_req_build(lmv, hur, lmv->tgts[i], req);
+
+				rc1 = obd_iocontrol(cmd, lmv->tgts[i]->ltd_exp,
+						    reqlen, req, uarg);
+				if (rc1 != 0 && rc == 0)
+					rc = rc1;
+				OBD_FREE_LARGE(req, reqlen);
+			}
+		}
+		break;
+	}
+	case LL_IOC_LOV_SWAP_LAYOUTS: {
+		struct md_op_data	*op_data = karg;
+		struct lmv_tgt_desc	*tgt1, *tgt2;
+
+		tgt1 = lmv_find_target(lmv, &op_data->op_fid1);
+		if (IS_ERR(tgt1))
+			return PTR_ERR(tgt1);
+
+		tgt2 = lmv_find_target(lmv, &op_data->op_fid2);
+		if (IS_ERR(tgt2))
+			return PTR_ERR(tgt2);
+
+		if ((tgt1->ltd_exp == NULL) || (tgt2->ltd_exp == NULL))
+			return -EINVAL;
+
+		/* only files on same MDT can have their layouts swapped */
+		if (tgt1->ltd_idx != tgt2->ltd_idx)
+			return -EPERM;
+
+		rc = obd_iocontrol(cmd, tgt1->ltd_exp, len, karg, uarg);
+		break;
+	}
+	case LL_IOC_HSM_CT_START: {
+		struct lustre_kernelcomm *lk = karg;
+		if (lk->lk_flags & LK_FLG_STOP)
+			rc = lmv_hsm_ct_unregister(lmv, cmd, len, lk, uarg);
+		else
+			rc = lmv_hsm_ct_register(lmv, cmd, len, lk, uarg);
+		break;
+	}
+	default:
+		for (i = 0; i < count; i++) {
+			struct obd_device *mdc_obd;
+			int err;
+
+			if (lmv->tgts[i] == NULL ||
+			    lmv->tgts[i]->ltd_exp == NULL)
+				continue;
+			/* ll_umount_begin() sets force flag but for lmv, not
+			 * mdc. Let's pass it through */
+			mdc_obd = class_exp2obd(lmv->tgts[i]->ltd_exp);
+			mdc_obd->obd_force = obddev->obd_force;
+			err = obd_iocontrol(cmd, lmv->tgts[i]->ltd_exp, len,
+					    karg, uarg);
+			if (err == -ENODATA && cmd == OBD_IOC_POLL_QUOTACHECK) {
+				return err;
+			} else if (err) {
+				if (lmv->tgts[i]->ltd_active) {
+					CERROR("error: iocontrol MDC %s on MDTidx %d cmd %x: err = %d\n",
+					       lmv->tgts[i]->ltd_uuid.uuid,
+					       i, cmd, err);
+					if (!rc)
+						rc = err;
+				}
+			} else
+				set = 1;
+		}
+		if (!set && !rc)
+			rc = -EIO;
+	}
+	return rc;
+}
+
+#if 0
+static int lmv_all_chars_policy(int count, const char *name,
+				int len)
+{
+	unsigned int c = 0;
+
+	while (len > 0)
+		c += name[--len];
+	c = c % count;
+	return c;
+}
+
+static int lmv_nid_policy(struct lmv_obd *lmv)
+{
+	struct obd_import *imp;
+	__u32	      id;
+
+	/*
+	 * XXX: To get nid we assume that underlying obd device is mdc.
+	 */
+	imp = class_exp2cliimp(lmv->tgts[0].ltd_exp);
+	id = imp->imp_connection->c_self ^ (imp->imp_connection->c_self >> 32);
+	return id % lmv->desc.ld_tgt_count;
+}
+
+static int lmv_choose_mds(struct lmv_obd *lmv, struct md_op_data *op_data,
+			  enum placement_policy placement)
+{
+	switch (placement) {
+	case PLACEMENT_CHAR_POLICY:
+		return lmv_all_chars_policy(lmv->desc.ld_tgt_count,
+					    op_data->op_name,
+					    op_data->op_namelen);
+	case PLACEMENT_NID_POLICY:
+		return lmv_nid_policy(lmv);
+
+	default:
+		break;
+	}
+
+	CERROR("Unsupported placement policy %x\n", placement);
+	return -EINVAL;
+}
+#endif
+
+/**
+ * This is _inode_ placement policy function (not name).
+ */
+static int lmv_placement_policy(struct obd_device *obd,
+				struct md_op_data *op_data, u32 *mds)
+{
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+
+	LASSERT(mds != NULL);
+
+	if (lmv->desc.ld_tgt_count == 1) {
+		*mds = 0;
+		return 0;
+	}
+
+	/**
+	 * If stripe_offset is provided during setdirstripe
+	 * (setdirstripe -i xx), xx MDS will be chosen.
+	 */
+	if (op_data->op_cli_flags & CLI_SET_MEA) {
+		struct lmv_user_md *lum;
+
+		lum = (struct lmv_user_md *)op_data->op_data;
+		if (lum->lum_type == LMV_STRIPE_TYPE &&
+		    lum->lum_stripe_offset != -1) {
+			if (lum->lum_stripe_offset >= lmv->desc.ld_tgt_count) {
+				CERROR("%s: Stripe_offset %d > MDT count %d: rc = %d\n",
+				       obd->obd_name,
+				       lum->lum_stripe_offset,
+				       lmv->desc.ld_tgt_count, -ERANGE);
+				return -ERANGE;
+			}
+			*mds = lum->lum_stripe_offset;
+			return 0;
+		}
+	}
+
+	/* Allocate new fid on target according to operation type and parent
+	 * home mds. */
+	*mds = op_data->op_mds;
+	return 0;
+}
+
+int __lmv_fid_alloc(struct lmv_obd *lmv, struct lu_fid *fid, u32 mds)
+{
+	struct lmv_tgt_desc	*tgt;
+	int			 rc;
+
+	tgt = lmv_get_target(lmv, mds);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	/*
+	 * New seq alloc and FLD setup should be atomic. Otherwise we may find
+	 * on server that seq in new allocated fid is not yet known.
+	 */
+	mutex_lock(&tgt->ltd_fid_mutex);
+
+	if (tgt->ltd_active == 0 || tgt->ltd_exp == NULL) {
+		rc = -ENODEV;
+		goto out;
+	}
+
+	/*
+	 * Asking underlaying tgt layer to allocate new fid.
+	 */
+	rc = obd_fid_alloc(tgt->ltd_exp, fid, NULL);
+	if (rc > 0) {
+		LASSERT(fid_is_sane(fid));
+		rc = 0;
+	}
+
+out:
+	mutex_unlock(&tgt->ltd_fid_mutex);
+	return rc;
+}
+
+int lmv_fid_alloc(struct obd_export *exp, struct lu_fid *fid,
+		  struct md_op_data *op_data)
+{
+	struct obd_device     *obd = class_exp2obd(exp);
+	struct lmv_obd	*lmv = &obd->u.lmv;
+	u32		       mds = 0;
+	int		    rc;
+
+	LASSERT(op_data != NULL);
+	LASSERT(fid != NULL);
+
+	rc = lmv_placement_policy(obd, op_data, &mds);
+	if (rc) {
+		CERROR("Can't get target for allocating fid, rc %d\n",
+		       rc);
+		return rc;
+	}
+
+	rc = __lmv_fid_alloc(lmv, fid, mds);
+	if (rc) {
+		CERROR("Can't alloc new fid, rc %d\n", rc);
+		return rc;
+	}
+
+	return rc;
+}
+
+static int lmv_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
+{
+	struct lmv_obd	     *lmv = &obd->u.lmv;
+	struct lprocfs_static_vars  lvars;
+	struct lmv_desc	    *desc;
+	int			 rc;
+
+	if (LUSTRE_CFG_BUFLEN(lcfg, 1) < 1) {
+		CERROR("LMV setup requires a descriptor\n");
+		return -EINVAL;
+	}
+
+	desc = (struct lmv_desc *)lustre_cfg_buf(lcfg, 1);
+	if (sizeof(*desc) > LUSTRE_CFG_BUFLEN(lcfg, 1)) {
+		CERROR("Lmv descriptor size wrong: %d > %d\n",
+		       (int)sizeof(*desc), LUSTRE_CFG_BUFLEN(lcfg, 1));
+		return -EINVAL;
+	}
+
+	OBD_ALLOC(lmv->tgts, sizeof(*lmv->tgts) * 32);
+	if (lmv->tgts == NULL)
+		return -ENOMEM;
+	lmv->tgts_size = 32;
+
+	obd_str2uuid(&lmv->desc.ld_uuid, desc->ld_uuid.uuid);
+	lmv->desc.ld_tgt_count = 0;
+	lmv->desc.ld_active_tgt_count = 0;
+	lmv->max_cookiesize = 0;
+	lmv->max_def_easize = 0;
+	lmv->max_easize = 0;
+	lmv->lmv_placement = PLACEMENT_CHAR_POLICY;
+
+	spin_lock_init(&lmv->lmv_lock);
+	mutex_init(&lmv->init_mutex);
+
+	lprocfs_lmv_init_vars(&lvars);
+
+	lprocfs_obd_setup(obd, lvars.obd_vars);
+#if defined (CONFIG_PROC_FS)
+	{
+		rc = lprocfs_seq_create(obd->obd_proc_entry, "target_obd",
+					0444, &lmv_proc_target_fops, obd);
+		if (rc)
+			CWARN("%s: error adding LMV target_obd file: rc = %d\n",
+			       obd->obd_name, rc);
+       }
+#endif
+	rc = fld_client_init(&lmv->lmv_fld, obd->obd_name,
+			     LUSTRE_CLI_FLD_HASH_DHT);
+	if (rc) {
+		CERROR("Can't init FLD, err %d\n", rc);
+		goto out;
+	}
+
+	return 0;
+
+out:
+	return rc;
+}
+
+static int lmv_cleanup(struct obd_device *obd)
+{
+	struct lmv_obd   *lmv = &obd->u.lmv;
+
+	fld_client_fini(&lmv->lmv_fld);
+	if (lmv->tgts != NULL) {
+		int i;
+		for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+			if (lmv->tgts[i] == NULL)
+				continue;
+			lmv_del_target(lmv, i);
+		}
+		OBD_FREE(lmv->tgts, sizeof(*lmv->tgts) * lmv->tgts_size);
+		lmv->tgts_size = 0;
+	}
+	return 0;
+}
+
+static int lmv_process_config(struct obd_device *obd, u32 len, void *buf)
+{
+	struct lustre_cfg	*lcfg = buf;
+	struct obd_uuid		obd_uuid;
+	int			gen;
+	__u32			index;
+	int			rc;
+
+	switch (lcfg->lcfg_command) {
+	case LCFG_ADD_MDC:
+		/* modify_mdc_tgts add 0:lustre-clilmv  1:lustre-MDT0000_UUID
+		 * 2:0  3:1  4:lustre-MDT0000-mdc_UUID */
+		if (LUSTRE_CFG_BUFLEN(lcfg, 1) > sizeof(obd_uuid.uuid)) {
+			rc = -EINVAL;
+			goto out;
+		}
+
+		obd_str2uuid(&obd_uuid,  lustre_cfg_buf(lcfg, 1));
+
+		if (sscanf(lustre_cfg_buf(lcfg, 2), "%d", &index) != 1) {
+			rc = -EINVAL;
+			goto out;
+		}
+		if (sscanf(lustre_cfg_buf(lcfg, 3), "%d", &gen) != 1) {
+			rc = -EINVAL;
+			goto out;
+		}
+		rc = lmv_add_target(obd, &obd_uuid, index, gen);
+		goto out;
+	default:
+		CERROR("Unknown command: %d\n", lcfg->lcfg_command);
+		rc = -EINVAL;
+		goto out;
+	}
+out:
+	return rc;
+}
+
+static int lmv_statfs(const struct lu_env *env, struct obd_export *exp,
+		      struct obd_statfs *osfs, __u64 max_age, __u32 flags)
+{
+	struct obd_device     *obd = class_exp2obd(exp);
+	struct lmv_obd	*lmv = &obd->u.lmv;
+	struct obd_statfs     *temp;
+	int		    rc = 0;
+	int		    i;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	OBD_ALLOC(temp, sizeof(*temp));
+	if (temp == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
+			continue;
+
+		rc = obd_statfs(env, lmv->tgts[i]->ltd_exp, temp,
+				max_age, flags);
+		if (rc) {
+			CERROR("can't stat MDS #%d (%s), error %d\n", i,
+			       lmv->tgts[i]->ltd_exp->exp_obd->obd_name,
+			       rc);
+			goto out_free_temp;
+		}
+
+		if (i == 0) {
+			*osfs = *temp;
+			/* If the statfs is from mount, it will needs
+			 * retrieve necessary information from MDT0.
+			 * i.e. mount does not need the merged osfs
+			 * from all of MDT.
+			 * And also clients can be mounted as long as
+			 * MDT0 is in service*/
+			if (flags & OBD_STATFS_FOR_MDT0)
+				goto out_free_temp;
+		} else {
+			osfs->os_bavail += temp->os_bavail;
+			osfs->os_blocks += temp->os_blocks;
+			osfs->os_ffree += temp->os_ffree;
+			osfs->os_files += temp->os_files;
+		}
+	}
+
+out_free_temp:
+	OBD_FREE(temp, sizeof(*temp));
+	return rc;
+}
+
+static int lmv_getstatus(struct obd_export *exp,
+			 struct lu_fid *fid,
+			 struct obd_capa **pc)
+{
+	struct obd_device    *obd = exp->exp_obd;
+	struct lmv_obd       *lmv = &obd->u.lmv;
+	int		   rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	rc = md_getstatus(lmv->tgts[0]->ltd_exp, fid, pc);
+	return rc;
+}
+
+static int lmv_getxattr(struct obd_export *exp, const struct lu_fid *fid,
+			struct obd_capa *oc, u64 valid, const char *name,
+			const char *input, int input_size, int output_size,
+			int flags, struct ptlrpc_request **request)
+{
+	struct obd_device      *obd = exp->exp_obd;
+	struct lmv_obd	 *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc    *tgt;
+	int		     rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_getxattr(tgt->ltd_exp, fid, oc, valid, name, input,
+			 input_size, output_size, flags, request);
+
+	return rc;
+}
+
+static int lmv_setxattr(struct obd_export *exp, const struct lu_fid *fid,
+			struct obd_capa *oc, u64 valid, const char *name,
+			const char *input, int input_size, int output_size,
+			int flags, __u32 suppgid,
+			struct ptlrpc_request **request)
+{
+	struct obd_device      *obd = exp->exp_obd;
+	struct lmv_obd	 *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc    *tgt;
+	int		     rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_setxattr(tgt->ltd_exp, fid, oc, valid, name, input,
+			 input_size, output_size, flags, suppgid,
+			 request);
+
+	return rc;
+}
+
+static int lmv_getattr(struct obd_export *exp, struct md_op_data *op_data,
+		       struct ptlrpc_request **request)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	if (op_data->op_flags & MF_GET_MDT_IDX) {
+		op_data->op_mds = tgt->ltd_idx;
+		return 0;
+	}
+
+	rc = md_getattr(tgt->ltd_exp, op_data, request);
+
+	return rc;
+}
+
+static int lmv_null_inode(struct obd_export *exp, const struct lu_fid *fid)
+{
+	struct obd_device   *obd = exp->exp_obd;
+	struct lmv_obd      *lmv = &obd->u.lmv;
+	int		  i;
+	int		  rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	CDEBUG(D_INODE, "CBDATA for "DFID"\n", PFID(fid));
+
+	/*
+	 * With DNE every object can have two locks in different namespaces:
+	 * lookup lock in space of MDT storing direntry and update/open lock in
+	 * space of MDT storing inode.
+	 */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
+			continue;
+		md_null_inode(lmv->tgts[i]->ltd_exp, fid);
+	}
+
+	return 0;
+}
+
+static int lmv_find_cbdata(struct obd_export *exp, const struct lu_fid *fid,
+			   ldlm_iterator_t it, void *data)
+{
+	struct obd_device   *obd = exp->exp_obd;
+	struct lmv_obd      *lmv = &obd->u.lmv;
+	int		  i;
+	int		  rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	CDEBUG(D_INODE, "CBDATA for "DFID"\n", PFID(fid));
+
+	/*
+	 * With DNE every object can have two locks in different namespaces:
+	 * lookup lock in space of MDT storing direntry and update/open lock in
+	 * space of MDT storing inode.
+	 */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
+			continue;
+		rc = md_find_cbdata(lmv->tgts[i]->ltd_exp, fid, it, data);
+		if (rc)
+			return rc;
+	}
+
+	return rc;
+}
+
+
+static int lmv_close(struct obd_export *exp, struct md_op_data *op_data,
+		     struct md_open_data *mod, struct ptlrpc_request **request)
+{
+	struct obd_device     *obd = exp->exp_obd;
+	struct lmv_obd	*lmv = &obd->u.lmv;
+	struct lmv_tgt_desc   *tgt;
+	int		    rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	CDEBUG(D_INODE, "CLOSE "DFID"\n", PFID(&op_data->op_fid1));
+	rc = md_close(tgt->ltd_exp, op_data, mod, request);
+	return rc;
+}
+
+struct lmv_tgt_desc
+*lmv_locate_mds(struct lmv_obd *lmv, struct md_op_data *op_data,
+		struct lu_fid *fid)
+{
+	struct lmv_tgt_desc *tgt;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return tgt;
+
+	op_data->op_mds = tgt->ltd_idx;
+
+	return tgt;
+}
+
+static int lmv_create(struct obd_export *exp, struct md_op_data *op_data,
+		      const void *data, int datalen, int mode, __u32 uid,
+		      __u32 gid, cfs_cap_t cap_effective, __u64 rdev,
+		      struct ptlrpc_request **request)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	if (!lmv->desc.ld_active_tgt_count)
+		return -EIO;
+
+	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = lmv_fid_alloc(exp, &op_data->op_fid2, op_data);
+	if (rc)
+		return rc;
+
+	CDEBUG(D_INODE, "CREATE '%*s' on "DFID" -> mds #%x\n",
+	       op_data->op_namelen, op_data->op_name, PFID(&op_data->op_fid1),
+	       op_data->op_mds);
+
+	op_data->op_flags |= MF_MDC_CANCEL_FID1;
+	rc = md_create(tgt->ltd_exp, op_data, data, datalen, mode, uid, gid,
+		       cap_effective, rdev, request);
+
+	if (rc == 0) {
+		if (*request == NULL)
+			return rc;
+		CDEBUG(D_INODE, "Created - "DFID"\n", PFID(&op_data->op_fid2));
+	}
+	return rc;
+}
+
+static int lmv_done_writing(struct obd_export *exp,
+			    struct md_op_data *op_data,
+			    struct md_open_data *mod)
+{
+	struct obd_device     *obd = exp->exp_obd;
+	struct lmv_obd	*lmv = &obd->u.lmv;
+	struct lmv_tgt_desc   *tgt;
+	int		    rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_done_writing(tgt->ltd_exp, op_data, mod);
+	return rc;
+}
+
+static int
+lmv_enqueue_remote(struct obd_export *exp, struct ldlm_enqueue_info *einfo,
+		   struct lookup_intent *it, struct md_op_data *op_data,
+		   struct lustre_handle *lockh, void *lmm, int lmmsize,
+		   __u64 extra_lock_flags)
+{
+	struct ptlrpc_request      *req = it->d.lustre.it_data;
+	struct obd_device	  *obd = exp->exp_obd;
+	struct lmv_obd	     *lmv = &obd->u.lmv;
+	struct lustre_handle	plock;
+	struct lmv_tgt_desc	*tgt;
+	struct md_op_data	  *rdata;
+	struct lu_fid	       fid1;
+	struct mdt_body	    *body;
+	int			 rc = 0;
+	int			 pmode;
+
+	body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
+	LASSERT(body != NULL);
+
+	if (!(body->valid & OBD_MD_MDS))
+		return 0;
+
+	CDEBUG(D_INODE, "REMOTE_ENQUEUE '%s' on "DFID" -> "DFID"\n",
+	       LL_IT2STR(it), PFID(&op_data->op_fid1), PFID(&body->fid1));
+
+	/*
+	 * We got LOOKUP lock, but we really need attrs.
+	 */
+	pmode = it->d.lustre.it_lock_mode;
+	LASSERT(pmode != 0);
+	memcpy(&plock, lockh, sizeof(plock));
+	it->d.lustre.it_lock_mode = 0;
+	it->d.lustre.it_data = NULL;
+	fid1 = body->fid1;
+
+	ptlrpc_req_finished(req);
+
+	tgt = lmv_find_target(lmv, &fid1);
+	if (IS_ERR(tgt)) {
+		rc = PTR_ERR(tgt);
+		goto out;
+	}
+
+	OBD_ALLOC_PTR(rdata);
+	if (rdata == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	rdata->op_fid1 = fid1;
+	rdata->op_bias = MDS_CROSS_REF;
+
+	rc = md_enqueue(tgt->ltd_exp, einfo, it, rdata, lockh,
+			lmm, lmmsize, NULL, extra_lock_flags);
+	OBD_FREE_PTR(rdata);
+out:
+	ldlm_lock_decref(&plock, pmode);
+	return rc;
+}
+
+static int
+lmv_enqueue(struct obd_export *exp, struct ldlm_enqueue_info *einfo,
+	    struct lookup_intent *it, struct md_op_data *op_data,
+	    struct lustre_handle *lockh, void *lmm, int lmmsize,
+	    struct ptlrpc_request **req, __u64 extra_lock_flags)
+{
+	struct obd_device	*obd = exp->exp_obd;
+	struct lmv_obd	   *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc      *tgt;
+	int		       rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	CDEBUG(D_INODE, "ENQUEUE '%s' on "DFID"\n",
+	       LL_IT2STR(it), PFID(&op_data->op_fid1));
+
+	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	CDEBUG(D_INODE, "ENQUEUE '%s' on "DFID" -> mds #%d\n",
+	       LL_IT2STR(it), PFID(&op_data->op_fid1), tgt->ltd_idx);
+
+	rc = md_enqueue(tgt->ltd_exp, einfo, it, op_data, lockh,
+			lmm, lmmsize, req, extra_lock_flags);
+
+	if (rc == 0 && it && it->it_op == IT_OPEN) {
+		rc = lmv_enqueue_remote(exp, einfo, it, op_data, lockh,
+					lmm, lmmsize, extra_lock_flags);
+	}
+	return rc;
+}
+
+static int
+lmv_getattr_name(struct obd_export *exp, struct md_op_data *op_data,
+		 struct ptlrpc_request **request)
+{
+	struct ptlrpc_request   *req = NULL;
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	struct mdt_body	 *body;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	CDEBUG(D_INODE, "GETATTR_NAME for %*s on "DFID" -> mds #%d\n",
+	       op_data->op_namelen, op_data->op_name, PFID(&op_data->op_fid1),
+	       tgt->ltd_idx);
+
+	rc = md_getattr_name(tgt->ltd_exp, op_data, request);
+	if (rc != 0)
+		return rc;
+
+	body = req_capsule_server_get(&(*request)->rq_pill,
+				      &RMF_MDT_BODY);
+	LASSERT(body != NULL);
+
+	if (body->valid & OBD_MD_MDS) {
+		struct lu_fid rid = body->fid1;
+		CDEBUG(D_INODE, "Request attrs for "DFID"\n",
+		       PFID(&rid));
+
+		tgt = lmv_find_target(lmv, &rid);
+		if (IS_ERR(tgt)) {
+			ptlrpc_req_finished(*request);
+			return PTR_ERR(tgt);
+		}
+
+		op_data->op_fid1 = rid;
+		op_data->op_valid |= OBD_MD_FLCROSSREF;
+		op_data->op_namelen = 0;
+		op_data->op_name = NULL;
+		rc = md_getattr_name(tgt->ltd_exp, op_data, &req);
+		ptlrpc_req_finished(*request);
+		*request = req;
+	}
+
+	return rc;
+}
+
+#define md_op_data_fid(op_data, fl)		     \
+	(fl == MF_MDC_CANCEL_FID1 ? &op_data->op_fid1 : \
+	 fl == MF_MDC_CANCEL_FID2 ? &op_data->op_fid2 : \
+	 fl == MF_MDC_CANCEL_FID3 ? &op_data->op_fid3 : \
+	 fl == MF_MDC_CANCEL_FID4 ? &op_data->op_fid4 : \
+	 NULL)
+
+static int lmv_early_cancel(struct obd_export *exp, struct md_op_data *op_data,
+			    int op_tgt, ldlm_mode_t mode, int bits, int flag)
+{
+	struct lu_fid	  *fid = md_op_data_fid(op_data, flag);
+	struct obd_device      *obd = exp->exp_obd;
+	struct lmv_obd	 *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc    *tgt;
+	ldlm_policy_data_t      policy = {{0}};
+	int		     rc = 0;
+
+	if (!fid_is_sane(fid))
+		return 0;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	if (tgt->ltd_idx != op_tgt) {
+		CDEBUG(D_INODE, "EARLY_CANCEL on "DFID"\n", PFID(fid));
+		policy.l_inodebits.bits = bits;
+		rc = md_cancel_unused(tgt->ltd_exp, fid, &policy,
+				      mode, LCF_ASYNC, NULL);
+	} else {
+		CDEBUG(D_INODE,
+		       "EARLY_CANCEL skip operation target %d on "DFID"\n",
+		       op_tgt, PFID(fid));
+		op_data->op_flags |= flag;
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/*
+ * llite passes fid of an target inode in op_data->op_fid1 and id of directory in
+ * op_data->op_fid2
+ */
+static int lmv_link(struct obd_export *exp, struct md_op_data *op_data,
+		    struct ptlrpc_request **request)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	LASSERT(op_data->op_namelen != 0);
+
+	CDEBUG(D_INODE, "LINK "DFID":%*s to "DFID"\n",
+	       PFID(&op_data->op_fid2), op_data->op_namelen,
+	       op_data->op_name, PFID(&op_data->op_fid1));
+
+	op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
+	op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
+	op_data->op_cap = cfs_curproc_cap_pack();
+	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid2);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	/*
+	 * Cancel UPDATE lock on child (fid1).
+	 */
+	op_data->op_flags |= MF_MDC_CANCEL_FID2;
+	rc = lmv_early_cancel(exp, op_data, tgt->ltd_idx, LCK_EX,
+			      MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID1);
+	if (rc != 0)
+		return rc;
+
+	rc = md_link(tgt->ltd_exp, op_data, request);
+
+	return rc;
+}
+
+static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
+		      const char *old, int oldlen, const char *new, int newlen,
+		      struct ptlrpc_request **request)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *src_tgt;
+	struct lmv_tgt_desc     *tgt_tgt;
+	int			rc;
+
+	LASSERT(oldlen != 0);
+
+	CDEBUG(D_INODE, "RENAME %*s in "DFID" to %*s in "DFID"\n",
+	       oldlen, old, PFID(&op_data->op_fid1),
+	       newlen, new, PFID(&op_data->op_fid2));
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
+	op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
+	op_data->op_cap = cfs_curproc_cap_pack();
+	src_tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(src_tgt))
+		return PTR_ERR(src_tgt);
+
+	tgt_tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid2);
+	if (IS_ERR(tgt_tgt))
+		return PTR_ERR(tgt_tgt);
+	/*
+	 * LOOKUP lock on src child (fid3) should also be cancelled for
+	 * src_tgt in mdc_rename.
+	 */
+	op_data->op_flags |= MF_MDC_CANCEL_FID1 | MF_MDC_CANCEL_FID3;
+
+	/*
+	 * Cancel UPDATE locks on tgt parent (fid2), tgt_tgt is its
+	 * own target.
+	 */
+	rc = lmv_early_cancel(exp, op_data, src_tgt->ltd_idx,
+			      LCK_EX, MDS_INODELOCK_UPDATE,
+			      MF_MDC_CANCEL_FID2);
+
+	/*
+	 * Cancel LOOKUP locks on tgt child (fid4) for parent tgt_tgt.
+	 */
+	if (rc == 0) {
+		rc = lmv_early_cancel(exp, op_data, src_tgt->ltd_idx,
+				      LCK_EX, MDS_INODELOCK_LOOKUP,
+				      MF_MDC_CANCEL_FID4);
+	}
+
+	/*
+	 * Cancel all the locks on tgt child (fid4).
+	 */
+	if (rc == 0)
+		rc = lmv_early_cancel(exp, op_data, src_tgt->ltd_idx,
+				      LCK_EX, MDS_INODELOCK_FULL,
+				      MF_MDC_CANCEL_FID4);
+
+	if (rc == 0)
+		rc = md_rename(src_tgt->ltd_exp, op_data, old, oldlen,
+			       new, newlen, request);
+	return rc;
+}
+
+static int lmv_setattr(struct obd_export *exp, struct md_op_data *op_data,
+		       void *ea, int ealen, void *ea2, int ea2len,
+		       struct ptlrpc_request **request,
+		       struct md_open_data **mod)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc = 0;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	CDEBUG(D_INODE, "SETATTR for "DFID", valid 0x%x\n",
+	       PFID(&op_data->op_fid1), op_data->op_attr.ia_valid);
+
+	op_data->op_flags |= MF_MDC_CANCEL_FID1;
+	tgt = lmv_find_target(lmv, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_setattr(tgt->ltd_exp, op_data, ea, ealen, ea2,
+			ea2len, request, mod);
+
+	return rc;
+}
+
+static int lmv_sync(struct obd_export *exp, const struct lu_fid *fid,
+		    struct obd_capa *oc, struct ptlrpc_request **request)
+{
+	struct obd_device	 *obd = exp->exp_obd;
+	struct lmv_obd	    *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc       *tgt;
+	int			rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_sync(tgt->ltd_exp, fid, oc, request);
+	return rc;
+}
+
+/*
+ * Adjust a set of pages, each page containing an array of lu_dirpages,
+ * so that each page can be used as a single logical lu_dirpage.
+ *
+ * A lu_dirpage is laid out as follows, where s = ldp_hash_start,
+ * e = ldp_hash_end, f = ldp_flags, p = padding, and each "ent" is a
+ * struct lu_dirent.  It has size up to LU_PAGE_SIZE. The ldp_hash_end
+ * value is used as a cookie to request the next lu_dirpage in a
+ * directory listing that spans multiple pages (two in this example):
+ *   ________
+ *  |	|
+ * .|--------v-------   -----.
+ * |s|e|f|p|ent|ent| ... |ent|
+ * '--|--------------   -----'   Each CFS_PAGE contains a single
+ *    '------.		   lu_dirpage.
+ * .---------v-------   -----.
+ * |s|e|f|p|ent| 0 | ... | 0 |
+ * '-----------------   -----'
+ *
+ * However, on hosts where the native VM page size (PAGE_CACHE_SIZE) is
+ * larger than LU_PAGE_SIZE, a single host page may contain multiple
+ * lu_dirpages. After reading the lu_dirpages from the MDS, the
+ * ldp_hash_end of the first lu_dirpage refers to the one immediately
+ * after it in the same CFS_PAGE (arrows simplified for brevity, but
+ * in general e0==s1, e1==s2, etc.):
+ *
+ * .--------------------   -----.
+ * |s0|e0|f0|p|ent|ent| ... |ent|
+ * |---v----------------   -----|
+ * |s1|e1|f1|p|ent|ent| ... |ent|
+ * |---v----------------   -----|  Here, each CFS_PAGE contains
+ *	     ...		 multiple lu_dirpages.
+ * |---v----------------   -----|
+ * |s'|e'|f'|p|ent|ent| ... |ent|
+ * '---|----------------   -----'
+ *     v
+ * .----------------------------.
+ * |	next CFS_PAGE       |
+ *
+ * This structure is transformed into a single logical lu_dirpage as follows:
+ *
+ * - Replace e0 with e' so the request for the next lu_dirpage gets the page
+ *   labeled 'next CFS_PAGE'.
+ *
+ * - Copy the LDF_COLLIDE flag from f' to f0 to correctly reflect whether
+ *   a hash collision with the next page exists.
+ *
+ * - Adjust the lde_reclen of the ending entry of each lu_dirpage to span
+ *   to the first entry of the next lu_dirpage.
+ */
+#if PAGE_CACHE_SIZE > LU_PAGE_SIZE
+static void lmv_adjust_dirpages(struct page **pages, int ncfspgs, int nlupgs)
+{
+	int i;
+
+	for (i = 0; i < ncfspgs; i++) {
+		struct lu_dirpage	*dp = kmap(pages[i]);
+		struct lu_dirpage	*first = dp;
+		struct lu_dirent	*end_dirent = NULL;
+		struct lu_dirent	*ent;
+		__u64			hash_end = dp->ldp_hash_end;
+		__u32			flags = dp->ldp_flags;
+
+		while (--nlupgs > 0) {
+			ent = lu_dirent_start(dp);
+			for (end_dirent = ent; ent != NULL;
+			     end_dirent = ent, ent = lu_dirent_next(ent));
+
+			/* Advance dp to next lu_dirpage. */
+			dp = (struct lu_dirpage *)((char *)dp + LU_PAGE_SIZE);
+
+			/* Check if we've reached the end of the CFS_PAGE. */
+			if (!((unsigned long)dp & ~CFS_PAGE_MASK))
+				break;
+
+			/* Save the hash and flags of this lu_dirpage. */
+			hash_end = dp->ldp_hash_end;
+			flags = dp->ldp_flags;
+
+			/* Check if lu_dirpage contains no entries. */
+			if (!end_dirent)
+				break;
+
+			/* Enlarge the end entry lde_reclen from 0 to
+			 * first entry of next lu_dirpage. */
+			LASSERT(le16_to_cpu(end_dirent->lde_reclen) == 0);
+			end_dirent->lde_reclen =
+				cpu_to_le16((char *)(dp->ldp_entries) -
+					    (char *)end_dirent);
+		}
+
+		first->ldp_hash_end = hash_end;
+		first->ldp_flags &= ~cpu_to_le32(LDF_COLLIDE);
+		first->ldp_flags |= flags & cpu_to_le32(LDF_COLLIDE);
+
+		kunmap(pages[i]);
+	}
+	LASSERTF(nlupgs == 0, "left = %d", nlupgs);
+}
+#else
+#define lmv_adjust_dirpages(pages, ncfspgs, nlupgs) do {} while (0)
+#endif	/* PAGE_CACHE_SIZE > LU_PAGE_SIZE */
+
+static int lmv_readpage(struct obd_export *exp, struct md_op_data *op_data,
+			struct page **pages, struct ptlrpc_request **request)
+{
+	struct obd_device	*obd = exp->exp_obd;
+	struct lmv_obd		*lmv = &obd->u.lmv;
+	__u64			offset = op_data->op_offset;
+	int			rc;
+	int			ncfspgs; /* pages read in PAGE_CACHE_SIZE */
+	int			nlupgs; /* pages read in LU_PAGE_SIZE */
+	struct lmv_tgt_desc	*tgt;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	CDEBUG(D_INODE, "READPAGE at %#llx from "DFID"\n",
+	       offset, PFID(&op_data->op_fid1));
+
+	tgt = lmv_find_target(lmv, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_readpage(tgt->ltd_exp, op_data, pages, request);
+	if (rc != 0)
+		return rc;
+
+	ncfspgs = ((*request)->rq_bulk->bd_nob_transferred + PAGE_CACHE_SIZE - 1)
+		 >> PAGE_CACHE_SHIFT;
+	nlupgs = (*request)->rq_bulk->bd_nob_transferred >> LU_PAGE_SHIFT;
+	LASSERT(!((*request)->rq_bulk->bd_nob_transferred & ~LU_PAGE_MASK));
+	LASSERT(ncfspgs > 0 && ncfspgs <= op_data->op_npages);
+
+	CDEBUG(D_INODE, "read %d(%d)/%d pages\n", ncfspgs, nlupgs,
+	       op_data->op_npages);
+
+	lmv_adjust_dirpages(pages, ncfspgs, nlupgs);
+
+	return rc;
+}
+
+static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
+		      struct ptlrpc_request **request)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt = NULL;
+	struct mdt_body		*body;
+	int		     rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+retry:
+	/* Send unlink requests to the MDT where the child is located */
+	if (likely(!fid_is_zero(&op_data->op_fid2)))
+		tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid2);
+	else
+		tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
+	op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
+	op_data->op_cap = cfs_curproc_cap_pack();
+
+	/*
+	 * If child's fid is given, cancel unused locks for it if it is from
+	 * another export than parent.
+	 *
+	 * LOOKUP lock for child (fid3) should also be cancelled on parent
+	 * tgt_tgt in mdc_unlink().
+	 */
+	op_data->op_flags |= MF_MDC_CANCEL_FID1 | MF_MDC_CANCEL_FID3;
+
+	/*
+	 * Cancel FULL locks on child (fid3).
+	 */
+	rc = lmv_early_cancel(exp, op_data, tgt->ltd_idx, LCK_EX,
+			      MDS_INODELOCK_FULL, MF_MDC_CANCEL_FID3);
+
+	if (rc != 0)
+		return rc;
+
+	CDEBUG(D_INODE, "unlink with fid="DFID"/"DFID" -> mds #%d\n",
+	       PFID(&op_data->op_fid1), PFID(&op_data->op_fid2), tgt->ltd_idx);
+
+	rc = md_unlink(tgt->ltd_exp, op_data, request);
+	if (rc != 0 && rc != -EREMOTE)
+		return rc;
+
+	body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
+	if (body == NULL)
+		return -EPROTO;
+
+	/* Not cross-ref case, just get out of here. */
+	if (likely(!(body->valid & OBD_MD_MDS)))
+		return 0;
+
+	CDEBUG(D_INODE, "%s: try unlink to another MDT for "DFID"\n",
+	       exp->exp_obd->obd_name, PFID(&body->fid1));
+
+	/* This is a remote object, try remote MDT, Note: it may
+	 * try more than 1 time here, Considering following case
+	 * /mnt/lustre is root on MDT0, remote1 is on MDT1
+	 * 1. Initially A does not know where remote1 is, it send
+	 *    unlink RPC to MDT0, MDT0 return -EREMOTE, it will
+	 *    resend unlink RPC to MDT1 (retry 1st time).
+	 *
+	 * 2. During the unlink RPC in flight,
+	 *    client B mv /mnt/lustre/remote1 /mnt/lustre/remote2
+	 *    and create new remote1, but on MDT0
+	 *
+	 * 3. MDT1 get unlink RPC(from A), then do remote lock on
+	 *    /mnt/lustre, then lookup get fid of remote1, and find
+	 *    it is remote dir again, and replay -EREMOTE again.
+	 *
+	 * 4. Then A will resend unlink RPC to MDT0. (retry 2nd times).
+	 *
+	 * In theory, it might try unlimited time here, but it should
+	 * be very rare case.  */
+	op_data->op_fid2 = body->fid1;
+	ptlrpc_req_finished(*request);
+	*request = NULL;
+
+	goto retry;
+}
+
+static int lmv_precleanup(struct obd_device *obd, enum obd_cleanup_stage stage)
+{
+	struct lmv_obd *lmv = &obd->u.lmv;
+
+	switch (stage) {
+	case OBD_CLEANUP_EARLY:
+		/* XXX: here should be calling obd_precleanup() down to
+		 * stack. */
+		break;
+	case OBD_CLEANUP_EXPORTS:
+		fld_client_proc_fini(&lmv->lmv_fld);
+		lprocfs_obd_cleanup(obd);
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static int lmv_get_info(const struct lu_env *env, struct obd_export *exp,
+			__u32 keylen, void *key, __u32 *vallen, void *val,
+			struct lov_stripe_md *lsm)
+{
+	struct obd_device       *obd;
+	struct lmv_obd	  *lmv;
+	int		      rc = 0;
+
+	obd = class_exp2obd(exp);
+	if (obd == NULL) {
+		CDEBUG(D_IOCTL, "Invalid client cookie %#llx\n",
+		       exp->exp_handle.h_cookie);
+		return -EINVAL;
+	}
+
+	lmv = &obd->u.lmv;
+	if (keylen >= strlen("remote_flag") && !strcmp(key, "remote_flag")) {
+		struct lmv_tgt_desc *tgt;
+		int i;
+
+		rc = lmv_check_connect(obd);
+		if (rc)
+			return rc;
+
+		LASSERT(*vallen == sizeof(__u32));
+		for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+			tgt = lmv->tgts[i];
+			/*
+			 * All tgts should be connected when this gets called.
+			 */
+			if (tgt == NULL || tgt->ltd_exp == NULL)
+				continue;
+
+			if (!obd_get_info(env, tgt->ltd_exp, keylen, key,
+					  vallen, val, NULL))
+				return 0;
+		}
+		return -EINVAL;
+	} else if (KEY_IS(KEY_MAX_EASIZE) ||
+		   KEY_IS(KEY_DEFAULT_EASIZE) ||
+		   KEY_IS(KEY_MAX_COOKIESIZE) ||
+		   KEY_IS(KEY_DEFAULT_COOKIESIZE) ||
+		   KEY_IS(KEY_CONN_DATA)) {
+		rc = lmv_check_connect(obd);
+		if (rc)
+			return rc;
+
+		/*
+		 * Forwarding this request to first MDS, it should know LOV
+		 * desc.
+		 */
+		rc = obd_get_info(env, lmv->tgts[0]->ltd_exp, keylen, key,
+				  vallen, val, NULL);
+		if (!rc && KEY_IS(KEY_CONN_DATA))
+			exp->exp_connect_data = *(struct obd_connect_data *)val;
+		return rc;
+	} else if (KEY_IS(KEY_TGT_COUNT)) {
+		*((int *)val) = lmv->desc.ld_tgt_count;
+		return 0;
+	}
+
+	CDEBUG(D_IOCTL, "Invalid key\n");
+	return -EINVAL;
+}
+
+static int lmv_set_info_async(const struct lu_env *env, struct obd_export *exp,
+			      u32 keylen, void *key, u32 vallen,
+			      void *val, struct ptlrpc_request_set *set)
+{
+	struct lmv_tgt_desc    *tgt;
+	struct obd_device      *obd;
+	struct lmv_obd	 *lmv;
+	int rc = 0;
+
+	obd = class_exp2obd(exp);
+	if (obd == NULL) {
+		CDEBUG(D_IOCTL, "Invalid client cookie %#llx\n",
+		       exp->exp_handle.h_cookie);
+		return -EINVAL;
+	}
+	lmv = &obd->u.lmv;
+
+	if (KEY_IS(KEY_READ_ONLY) || KEY_IS(KEY_FLUSH_CTX)) {
+		int i, err = 0;
+
+		for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+			tgt = lmv->tgts[i];
+
+			if (tgt == NULL || tgt->ltd_exp == NULL)
+				continue;
+
+			err = obd_set_info_async(env, tgt->ltd_exp,
+						 keylen, key, vallen, val, set);
+			if (err && rc == 0)
+				rc = err;
+		}
+
+		return rc;
+	}
+
+	return -EINVAL;
+}
+
+static int lmv_packmd(struct obd_export *exp, struct lov_mds_md **lmmp,
+		      struct lov_stripe_md *lsm)
+{
+	struct obd_device	 *obd = class_exp2obd(exp);
+	struct lmv_obd	    *lmv = &obd->u.lmv;
+	struct lmv_stripe_md      *meap;
+	struct lmv_stripe_md      *lsmp;
+	int			mea_size;
+	int			i;
+
+	mea_size = lmv_get_easize(lmv);
+	if (!lmmp)
+		return mea_size;
+
+	if (*lmmp && !lsm) {
+		OBD_FREE_LARGE(*lmmp, mea_size);
+		*lmmp = NULL;
+		return 0;
+	}
+
+	if (*lmmp == NULL) {
+		OBD_ALLOC_LARGE(*lmmp, mea_size);
+		if (*lmmp == NULL)
+			return -ENOMEM;
+	}
+
+	if (!lsm)
+		return mea_size;
+
+	lsmp = (struct lmv_stripe_md *)lsm;
+	meap = (struct lmv_stripe_md *)*lmmp;
+
+	if (lsmp->mea_magic != MEA_MAGIC_LAST_CHAR &&
+	    lsmp->mea_magic != MEA_MAGIC_ALL_CHARS)
+		return -EINVAL;
+
+	meap->mea_magic = cpu_to_le32(lsmp->mea_magic);
+	meap->mea_count = cpu_to_le32(lsmp->mea_count);
+	meap->mea_master = cpu_to_le32(lsmp->mea_master);
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		meap->mea_ids[i] = lsmp->mea_ids[i];
+		fid_cpu_to_le(&meap->mea_ids[i], &lsmp->mea_ids[i]);
+	}
+
+	return mea_size;
+}
+
+static int lmv_unpackmd(struct obd_export *exp, struct lov_stripe_md **lsmp,
+			struct lov_mds_md *lmm, int lmm_size)
+{
+	struct obd_device	  *obd = class_exp2obd(exp);
+	struct lmv_stripe_md      **tmea = (struct lmv_stripe_md **)lsmp;
+	struct lmv_stripe_md       *mea = (struct lmv_stripe_md *)lmm;
+	struct lmv_obd	     *lmv = &obd->u.lmv;
+	int			 mea_size;
+	int			 i;
+	__u32		       magic;
+
+	mea_size = lmv_get_easize(lmv);
+	if (lsmp == NULL)
+		return mea_size;
+
+	if (*lsmp != NULL && lmm == NULL) {
+		OBD_FREE_LARGE(*tmea, mea_size);
+		*lsmp = NULL;
+		return 0;
+	}
+
+	LASSERT(mea_size == lmm_size);
+
+	OBD_ALLOC_LARGE(*tmea, mea_size);
+	if (*tmea == NULL)
+		return -ENOMEM;
+
+	if (!lmm)
+		return mea_size;
+
+	if (mea->mea_magic == MEA_MAGIC_LAST_CHAR ||
+	    mea->mea_magic == MEA_MAGIC_ALL_CHARS ||
+	    mea->mea_magic == MEA_MAGIC_HASH_SEGMENT) {
+		magic = le32_to_cpu(mea->mea_magic);
+	} else {
+		/*
+		 * Old mea is not handled here.
+		 */
+		CERROR("Old not supportable EA is found\n");
+		LBUG();
+	}
+
+	(*tmea)->mea_magic = magic;
+	(*tmea)->mea_count = le32_to_cpu(mea->mea_count);
+	(*tmea)->mea_master = le32_to_cpu(mea->mea_master);
+
+	for (i = 0; i < (*tmea)->mea_count; i++) {
+		(*tmea)->mea_ids[i] = mea->mea_ids[i];
+		fid_le_to_cpu(&(*tmea)->mea_ids[i], &(*tmea)->mea_ids[i]);
+	}
+	return mea_size;
+}
+
+static int lmv_cancel_unused(struct obd_export *exp, const struct lu_fid *fid,
+			     ldlm_policy_data_t *policy, ldlm_mode_t mode,
+			     ldlm_cancel_flags_t flags, void *opaque)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	int		      rc = 0;
+	int		      err;
+	int		      i;
+
+	LASSERT(fid != NULL);
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL ||
+		    lmv->tgts[i]->ltd_active == 0)
+			continue;
+
+		err = md_cancel_unused(lmv->tgts[i]->ltd_exp, fid,
+				       policy, mode, flags, opaque);
+		if (!rc)
+			rc = err;
+	}
+	return rc;
+}
+
+static int lmv_set_lock_data(struct obd_export *exp, __u64 *lockh, void *data,
+			     __u64 *bits)
+{
+	struct lmv_obd	  *lmv = &exp->exp_obd->u.lmv;
+	int		      rc;
+
+	rc =  md_set_lock_data(lmv->tgts[0]->ltd_exp, lockh, data, bits);
+	return rc;
+}
+
+static ldlm_mode_t lmv_lock_match(struct obd_export *exp, __u64 flags,
+				  const struct lu_fid *fid, ldlm_type_t type,
+				  ldlm_policy_data_t *policy, ldlm_mode_t mode,
+				  struct lustre_handle *lockh)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	ldlm_mode_t	      rc;
+	int		      i;
+
+	CDEBUG(D_INODE, "Lock match for "DFID"\n", PFID(fid));
+
+	/*
+	 * With CMD every object can have two locks in different namespaces:
+	 * lookup lock in space of mds storing direntry and update/open lock in
+	 * space of mds storing inode. Thus we check all targets, not only that
+	 * one fid was created in.
+	 */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		if (lmv->tgts[i] == NULL ||
+		    lmv->tgts[i]->ltd_exp == NULL ||
+		    lmv->tgts[i]->ltd_active == 0)
+			continue;
+
+		rc = md_lock_match(lmv->tgts[i]->ltd_exp, flags, fid,
+				   type, policy, mode, lockh);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+static int lmv_get_lustre_md(struct obd_export *exp,
+			     struct ptlrpc_request *req,
+			     struct obd_export *dt_exp,
+			     struct obd_export *md_exp,
+			     struct lustre_md *md)
+{
+	struct lmv_obd	  *lmv = &exp->exp_obd->u.lmv;
+
+	return md_get_lustre_md(lmv->tgts[0]->ltd_exp, req, dt_exp, md_exp, md);
+}
+
+static int lmv_free_lustre_md(struct obd_export *exp, struct lustre_md *md)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+
+	if (md->mea)
+		obd_free_memmd(exp, (void *)&md->mea);
+	return md_free_lustre_md(lmv->tgts[0]->ltd_exp, md);
+}
+
+static int lmv_set_open_replay_data(struct obd_export *exp,
+				    struct obd_client_handle *och,
+				    struct lookup_intent *it)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+
+	tgt = lmv_find_target(lmv, &och->och_fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	return md_set_open_replay_data(tgt->ltd_exp, och, it);
+}
+
+static int lmv_clear_open_replay_data(struct obd_export *exp,
+				      struct obd_client_handle *och)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+
+	tgt = lmv_find_target(lmv, &och->och_fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	return md_clear_open_replay_data(tgt->ltd_exp, och);
+}
+
+static int lmv_get_remote_perm(struct obd_export *exp,
+			       const struct lu_fid *fid,
+			       struct obd_capa *oc, __u32 suppgid,
+			       struct ptlrpc_request **request)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_get_remote_perm(tgt->ltd_exp, fid, oc, suppgid, request);
+	return rc;
+}
+
+static int lmv_renew_capa(struct obd_export *exp, struct obd_capa *oc,
+			  renew_capa_cb_t cb)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, &oc->c_capa.lc_fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_renew_capa(tgt->ltd_exp, oc, cb);
+	return rc;
+}
+
+static int lmv_unpack_capa(struct obd_export *exp, struct ptlrpc_request *req,
+			   const struct req_msg_field *field,
+			   struct obd_capa **oc)
+{
+	struct lmv_obd *lmv = &exp->exp_obd->u.lmv;
+
+	return md_unpack_capa(lmv->tgts[0]->ltd_exp, req, field, oc);
+}
+
+static int lmv_intent_getattr_async(struct obd_export *exp,
+				    struct md_enqueue_info *minfo,
+				    struct ldlm_enqueue_info *einfo)
+{
+	struct md_op_data       *op_data = &minfo->mi_data;
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt = NULL;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, &op_data->op_fid1);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_intent_getattr_async(tgt->ltd_exp, minfo, einfo);
+	return rc;
+}
+
+static int lmv_revalidate_lock(struct obd_export *exp, struct lookup_intent *it,
+			       struct lu_fid *fid, __u64 *bits)
+{
+	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_obd	  *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc     *tgt;
+	int		      rc;
+
+	rc = lmv_check_connect(obd);
+	if (rc)
+		return rc;
+
+	tgt = lmv_find_target(lmv, fid);
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
+	rc = md_revalidate_lock(tgt->ltd_exp, it, fid, bits);
+	return rc;
+}
+
+/**
+ * For lmv, only need to send request to master MDT, and the master MDT will
+ * process with other slave MDTs. The only exception is Q_GETOQUOTA for which
+ * we directly fetch data from the slave MDTs.
+ */
+static int lmv_quotactl(struct obd_device *unused, struct obd_export *exp,
+			struct obd_quotactl *oqctl)
+{
+	struct obd_device   *obd = class_exp2obd(exp);
+	struct lmv_obd      *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc *tgt = lmv->tgts[0];
+	int		  rc = 0, i;
+	__u64		curspace, curinodes;
+
+	if (!lmv->desc.ld_tgt_count || !tgt->ltd_active) {
+		CERROR("master lmv inactive\n");
+		return -EIO;
+	}
+
+	if (oqctl->qc_cmd != Q_GETOQUOTA) {
+		rc = obd_quotactl(tgt->ltd_exp, oqctl);
+		return rc;
+	}
+
+	curspace = curinodes = 0;
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		int err;
+		tgt = lmv->tgts[i];
+
+		if (tgt == NULL || tgt->ltd_exp == NULL || tgt->ltd_active == 0)
+			continue;
+		if (!tgt->ltd_active) {
+			CDEBUG(D_HA, "mdt %d is inactive.\n", i);
+			continue;
+		}
+
+		err = obd_quotactl(tgt->ltd_exp, oqctl);
+		if (err) {
+			CERROR("getquota on mdt %d failed. %d\n", i, err);
+			if (!rc)
+				rc = err;
+		} else {
+			curspace += oqctl->qc_dqblk.dqb_curspace;
+			curinodes += oqctl->qc_dqblk.dqb_curinodes;
+		}
+	}
+	oqctl->qc_dqblk.dqb_curspace = curspace;
+	oqctl->qc_dqblk.dqb_curinodes = curinodes;
+
+	return rc;
+}
+
+static int lmv_quotacheck(struct obd_device *unused, struct obd_export *exp,
+			  struct obd_quotactl *oqctl)
+{
+	struct obd_device   *obd = class_exp2obd(exp);
+	struct lmv_obd      *lmv = &obd->u.lmv;
+	struct lmv_tgt_desc *tgt;
+	int		  i, rc = 0;
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		int err;
+		tgt = lmv->tgts[i];
+		if (tgt == NULL || tgt->ltd_exp == NULL || !tgt->ltd_active) {
+			CERROR("lmv idx %d inactive\n", i);
+			return -EIO;
+		}
+
+		err = obd_quotacheck(tgt->ltd_exp, oqctl);
+		if (err && !rc)
+			rc = err;
+	}
+
+	return rc;
+}
+
+static struct obd_ops lmv_obd_ops = {
+	.o_owner		= THIS_MODULE,
+	.o_setup		= lmv_setup,
+	.o_cleanup	      = lmv_cleanup,
+	.o_precleanup	   = lmv_precleanup,
+	.o_process_config       = lmv_process_config,
+	.o_connect	      = lmv_connect,
+	.o_disconnect	   = lmv_disconnect,
+	.o_statfs	       = lmv_statfs,
+	.o_get_info	     = lmv_get_info,
+	.o_set_info_async       = lmv_set_info_async,
+	.o_packmd	       = lmv_packmd,
+	.o_unpackmd	     = lmv_unpackmd,
+	.o_notify	       = lmv_notify,
+	.o_get_uuid	     = lmv_get_uuid,
+	.o_iocontrol	    = lmv_iocontrol,
+	.o_quotacheck	   = lmv_quotacheck,
+	.o_quotactl	     = lmv_quotactl
+};
+
+static struct md_ops lmv_md_ops = {
+	.m_getstatus	    = lmv_getstatus,
+	.m_null_inode		= lmv_null_inode,
+	.m_find_cbdata	  = lmv_find_cbdata,
+	.m_close		= lmv_close,
+	.m_create	       = lmv_create,
+	.m_done_writing	 = lmv_done_writing,
+	.m_enqueue	      = lmv_enqueue,
+	.m_getattr	      = lmv_getattr,
+	.m_getxattr	     = lmv_getxattr,
+	.m_getattr_name	 = lmv_getattr_name,
+	.m_intent_lock	  = lmv_intent_lock,
+	.m_link		 = lmv_link,
+	.m_rename	       = lmv_rename,
+	.m_setattr	      = lmv_setattr,
+	.m_setxattr	     = lmv_setxattr,
+	.m_sync		 = lmv_sync,
+	.m_readpage	     = lmv_readpage,
+	.m_unlink	       = lmv_unlink,
+	.m_init_ea_size	 = lmv_init_ea_size,
+	.m_cancel_unused	= lmv_cancel_unused,
+	.m_set_lock_data	= lmv_set_lock_data,
+	.m_lock_match	   = lmv_lock_match,
+	.m_get_lustre_md	= lmv_get_lustre_md,
+	.m_free_lustre_md       = lmv_free_lustre_md,
+	.m_set_open_replay_data = lmv_set_open_replay_data,
+	.m_clear_open_replay_data = lmv_clear_open_replay_data,
+	.m_renew_capa	   = lmv_renew_capa,
+	.m_unpack_capa	  = lmv_unpack_capa,
+	.m_get_remote_perm      = lmv_get_remote_perm,
+	.m_intent_getattr_async = lmv_intent_getattr_async,
+	.m_revalidate_lock      = lmv_revalidate_lock
+};
+
+static int __init lmv_init(void)
+{
+	struct lprocfs_static_vars lvars;
+	int			rc;
+
+	lprocfs_lmv_init_vars(&lvars);
+
+	rc = class_register_type(&lmv_obd_ops, &lmv_md_ops,
+				 lvars.module_vars, LUSTRE_LMV_NAME, NULL);
+	return rc;
+}
+
+static void lmv_exit(void)
+{
+	class_unregister_type(LUSTRE_LMV_NAME);
+}
+
+MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
+MODULE_DESCRIPTION("Lustre Logical Metadata Volume OBD driver");
+MODULE_LICENSE("GPL");
+
+module_init(lmv_init);
+module_exit(lmv_exit);
diff --git a/drivers/staging/lustre/lustre/lmv/lproc_lmv.c b/drivers/staging/lustre/lustre/lmv/lproc_lmv.c
new file mode 100644
index 000000000..22e5c315f
--- /dev/null
+++ b/drivers/staging/lustre/lustre/lmv/lproc_lmv.c
@@ -0,0 +1,237 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#define DEBUG_SUBSYSTEM S_CLASS
+
+#include <linux/seq_file.h>
+#include <linux/statfs.h>
+#include "../include/lprocfs_status.h"
+#include "../include/obd_class.h"
+#include "lmv_internal.h"
+
+static int lmv_numobd_seq_show(struct seq_file *m, void *v)
+{
+	struct obd_device       *dev = (struct obd_device *)m->private;
+	struct lmv_desc	 *desc;
+
+	LASSERT(dev != NULL);
+	desc = &dev->u.lmv.desc;
+	seq_printf(m, "%u\n", desc->ld_tgt_count);
+	return 0;
+}
+LPROC_SEQ_FOPS_RO(lmv_numobd);
+
+static const char *placement_name[] = {
+	[PLACEMENT_CHAR_POLICY] = "CHAR",
+	[PLACEMENT_NID_POLICY]  = "NID",
+	[PLACEMENT_INVAL_POLICY]  = "INVAL"
+};
+
+static enum placement_policy placement_name2policy(char *name, int len)
+{
+	int		     i;
+
+	for (i = 0; i < PLACEMENT_MAX_POLICY; i++) {
+		if (!strncmp(placement_name[i], name, len))
+			return i;
+	}
+	return PLACEMENT_INVAL_POLICY;
+}
+
+static const char *placement_policy2name(enum placement_policy placement)
+{
+	LASSERT(placement < PLACEMENT_MAX_POLICY);
+	return placement_name[placement];
+}
+
+static int lmv_placement_seq_show(struct seq_file *m, void *v)
+{
+	struct obd_device       *dev = (struct obd_device *)m->private;
+	struct lmv_obd	  *lmv;
+
+	LASSERT(dev != NULL);
+	lmv = &dev->u.lmv;
+	seq_printf(m, "%s\n", placement_policy2name(lmv->lmv_placement));
+	return 0;
+}
+
+#define MAX_POLICY_STRING_SIZE 64
+
+static ssize_t lmv_placement_seq_write(struct file *file,
+					const char __user *buffer,
+					size_t count, loff_t *off)
+{
+	struct obd_device *dev = ((struct seq_file *)file->private_data)->private;
+	char		     dummy[MAX_POLICY_STRING_SIZE + 1];
+	int		      len = count;
+	enum placement_policy       policy;
+	struct lmv_obd	  *lmv;
+
+	if (copy_from_user(dummy, buffer, MAX_POLICY_STRING_SIZE))
+		return -EFAULT;
+
+	LASSERT(dev != NULL);
+	lmv = &dev->u.lmv;
+
+	if (len > MAX_POLICY_STRING_SIZE)
+		len = MAX_POLICY_STRING_SIZE;
+
+	if (dummy[len - 1] == '\n')
+		len--;
+	dummy[len] = '\0';
+
+	policy = placement_name2policy(dummy, len);
+	if (policy != PLACEMENT_INVAL_POLICY) {
+		spin_lock(&lmv->lmv_lock);
+		lmv->lmv_placement = policy;
+		spin_unlock(&lmv->lmv_lock);
+	} else {
+		CERROR("Invalid placement policy \"%s\"!\n", dummy);
+		return -EINVAL;
+	}
+	return count;
+}
+LPROC_SEQ_FOPS(lmv_placement);
+
+static int lmv_activeobd_seq_show(struct seq_file *m, void *v)
+{
+	struct obd_device       *dev = (struct obd_device *)m->private;
+	struct lmv_desc	 *desc;
+
+	LASSERT(dev != NULL);
+	desc = &dev->u.lmv.desc;
+	seq_printf(m, "%u\n", desc->ld_active_tgt_count);
+	return 0;
+}
+LPROC_SEQ_FOPS_RO(lmv_activeobd);
+
+static int lmv_desc_uuid_seq_show(struct seq_file *m, void *v)
+{
+	struct obd_device *dev = (struct obd_device *)m->private;
+	struct lmv_obd	  *lmv;
+
+	LASSERT(dev != NULL);
+	lmv = &dev->u.lmv;
+	seq_printf(m, "%s\n", lmv->desc.ld_uuid.uuid);
+	return 0;
+}
+LPROC_SEQ_FOPS_RO(lmv_desc_uuid);
+
+static void *lmv_tgt_seq_start(struct seq_file *p, loff_t *pos)
+{
+	struct obd_device       *dev = p->private;
+	struct lmv_obd	  *lmv = &dev->u.lmv;
+	return (*pos >= lmv->desc.ld_tgt_count) ? NULL : lmv->tgts[*pos];
+}
+
+static void lmv_tgt_seq_stop(struct seq_file *p, void *v)
+{
+	return;
+}
+
+static void *lmv_tgt_seq_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct obd_device       *dev = p->private;
+	struct lmv_obd	  *lmv = &dev->u.lmv;
+	++*pos;
+	return (*pos >= lmv->desc.ld_tgt_count) ? NULL : lmv->tgts[*pos];
+}
+
+static int lmv_tgt_seq_show(struct seq_file *p, void *v)
+{
+	struct lmv_tgt_desc     *tgt = v;
+
+	if (tgt == NULL)
+		return 0;
+	seq_printf(p, "%d: %s %sACTIVE\n",
+		   tgt->ltd_idx, tgt->ltd_uuid.uuid,
+		   tgt->ltd_active ? "" : "IN");
+	return 0;
+}
+
+static struct seq_operations lmv_tgt_sops = {
+	.start		 = lmv_tgt_seq_start,
+	.stop		  = lmv_tgt_seq_stop,
+	.next		  = lmv_tgt_seq_next,
+	.show		  = lmv_tgt_seq_show,
+};
+
+static int lmv_target_seq_open(struct inode *inode, struct file *file)
+{
+	struct seq_file	 *seq;
+	int		     rc;
+
+	rc = seq_open(file, &lmv_tgt_sops);
+	if (rc)
+		return rc;
+
+	seq = file->private_data;
+	seq->private = PDE_DATA(inode);
+
+	return 0;
+}
+
+LPROC_SEQ_FOPS_RO_TYPE(lmv, uuid);
+
+static struct lprocfs_vars lprocfs_lmv_obd_vars[] = {
+	{ "numobd",	  &lmv_numobd_fops,	  NULL, 0 },
+	{ "placement",	  &lmv_placement_fops,    NULL, 0 },
+	{ "activeobd",	  &lmv_activeobd_fops,    NULL, 0 },
+	{ "uuid",	  &lmv_uuid_fops,	  NULL, 0 },
+	{ "desc_uuid",	  &lmv_desc_uuid_fops,    NULL, 0 },
+	{ NULL }
+};
+
+LPROC_SEQ_FOPS_RO_TYPE(lmv, numrefs);
+
+static struct lprocfs_vars lprocfs_lmv_module_vars[] = {
+	{ "num_refs",	   &lmv_numrefs_fops, NULL, 0 },
+	{ NULL }
+};
+
+struct file_operations lmv_proc_target_fops = {
+	.owner		= THIS_MODULE,
+	.open		 = lmv_target_seq_open,
+	.read		 = seq_read,
+	.llseek	       = seq_lseek,
+	.release	      = seq_release,
+};
+
+void lprocfs_lmv_init_vars(struct lprocfs_static_vars *lvars)
+{
+	lvars->module_vars    = lprocfs_lmv_module_vars;
+	lvars->obd_vars       = lprocfs_lmv_obd_vars;
+}