text: /*
   * 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, 2015, 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;
  	}
  
  	op_data = kzalloc(sizeof(*op_data), GFP_NOFS);
  	if (!op_data) {
  		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:
  	kfree(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.
   */
  static 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.
   */
  static 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;
  }
  