drivers/staging/lustre/lustre/lmv/lmv_intent.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_LMV
  38 #include <linux/slab.h>
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/pagemap.h>
  42 #include <asm/div64.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/namei.h>
  45 #include <linux/lustre_intent.h>
  46
  47 #include <obd_support.h>
  48 #include <lustre/lustre_idl.h>
  49 #include <lustre_lib.h>
  50 #include <lustre_net.h>
  51 #include <lustre_dlm.h>
  52 #include <obd_class.h>
  53 #include <lprocfs_status.h>
  54 #include "lmv_internal.h"
  55
  56 static int lmv_intent_remote(struct obd_export *exp, void *lmm,
  57                              int lmmsize, struct lookup_intent *it,
  58                              const struct lu_fid *parent_fid, int flags,
  59                              struct ptlrpc_request **reqp,
  60                              ldlm_blocking_callback cb_blocking,
  61                              __u64 extra_lock_flags)
  62 {
  63         struct obd_device       *obd = exp->exp_obd;
  64         struct lmv_obd          *lmv = &obd->u.lmv;
  65         struct ptlrpc_request   *req = NULL;
  66         struct lustre_handle    plock;
  67         struct md_op_data       *op_data;
  68         struct lmv_tgt_desc     *tgt;
  69         struct mdt_body         *body;
  70         int                     pmode;
  71         int                     rc = 0;
  72
  73         body = req_capsule_server_get(&(*reqp)->rq_pill, &RMF_MDT_BODY);
  74         if (body == NULL)
  75                 return -EPROTO;
  76
  77         LASSERT((body->valid & OBD_MD_MDS));
  78
  79         /*
  80          * Unfortunately, we have to lie to MDC/MDS to retrieve
  81          * attributes llite needs and provideproper locking.
  82          */
  83         if (it->it_op & IT_LOOKUP)
  84                 it->it_op = IT_GETATTR;
  85
  86         /*
  87          * We got LOOKUP lock, but we really need attrs.
  88          */
  89         pmode = it->d.lustre.it_lock_mode;
  90         if (pmode) {
  91                 plock.cookie = it->d.lustre.it_lock_handle;
  92                 it->d.lustre.it_lock_mode = 0;
  93                 it->d.lustre.it_data = NULL;
  94         }
  95
  96         LASSERT(fid_is_sane(&body->fid1));
  97
  98         tgt = lmv_find_target(lmv, &body->fid1);
  99         if (IS_ERR(tgt))
 100                 GOTO(out, rc = PTR_ERR(tgt));
 101
 102         OBD_ALLOC_PTR(op_data);
 103         if (op_data == NULL)
 104                 GOTO(out, rc = -ENOMEM);
 105
 106         op_data->op_fid1 = body->fid1;
 107         /* Sent the parent FID to the remote MDT */
 108         if (parent_fid != NULL) {
 109                 /* The parent fid is only for remote open to
 110                  * check whether the open is from OBF,
 111                  * see mdt_cross_open */
 112                 LASSERT(it->it_op & IT_OPEN);
 113                 op_data->op_fid2 = *parent_fid;
 114                 /* Add object FID to op_fid3, in case it needs to check stale
 115                  * (M_CHECK_STALE), see mdc_finish_intent_lock */
 116                 op_data->op_fid3 = body->fid1;
 117         }
 118
 119         op_data->op_bias = MDS_CROSS_REF;
 120         CDEBUG(D_INODE, "REMOTE_INTENT with fid="DFID" -> mds #%d\n",
 121                PFID(&body->fid1), tgt->ltd_idx);
 122
 123         it->d.lustre.it_disposition &= ~DISP_ENQ_COMPLETE;
 124         rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it,
 125                             flags, &req, cb_blocking, extra_lock_flags);
 126         if (rc)
 127                 GOTO(out_free_op_data, rc);
 128
 129         /*
 130          * LLite needs LOOKUP lock to track dentry revocation in order to
 131          * maintain dcache consistency. Thus drop UPDATE|PERM lock here
 132          * and put LOOKUP in request.
 133          */
 134         if (it->d.lustre.it_lock_mode != 0) {
 135                 it->d.lustre.it_remote_lock_handle =
 136                                         it->d.lustre.it_lock_handle;
 137                 it->d.lustre.it_remote_lock_mode = it->d.lustre.it_lock_mode;
 138         }
 139
 140         it->d.lustre.it_lock_handle = plock.cookie;
 141         it->d.lustre.it_lock_mode = pmode;
 142
 143 out_free_op_data:
 144         OBD_FREE_PTR(op_data);
 145 out:
 146         if (rc && pmode)
 147                 ldlm_lock_decref(&plock, pmode);
 148
 149         ptlrpc_req_finished(*reqp);
 150         *reqp = req;
 151         return rc;
 152 }
 153
 154 /*
 155  * IT_OPEN is intended to open (and create, possible) an object. Parent (pid)
 156  * may be split dir.
 157  */
 158 int lmv_intent_open(struct obd_export *exp, struct md_op_data *op_data,
 159                     void *lmm, int lmmsize, struct lookup_intent *it,
 160                     int flags, struct ptlrpc_request **reqp,
 161                     ldlm_blocking_callback cb_blocking,
 162                     __u64 extra_lock_flags)
 163 {
 164         struct obd_device       *obd = exp->exp_obd;
 165         struct lmv_obd          *lmv = &obd->u.lmv;
 166         struct lmv_tgt_desc     *tgt;
 167         struct mdt_body         *body;
 168         int                     rc;
 169
 170         tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
 171         if (IS_ERR(tgt))
 172                 return PTR_ERR(tgt);
 173
 174         /* If it is ready to open the file by FID, do not need
 175          * allocate FID at all, otherwise it will confuse MDT */
 176         if ((it->it_op & IT_CREAT) &&
 177             !(it->it_flags & MDS_OPEN_BY_FID)) {
 178                 /*
 179                  * For open with IT_CREATE and for IT_CREATE cases allocate new
 180                  * fid and setup FLD for it.
 181                  */
 182                 op_data->op_fid3 = op_data->op_fid2;
 183                 rc = lmv_fid_alloc(exp, &op_data->op_fid2, op_data);
 184                 if (rc != 0)
 185                         return rc;
 186         }
 187
 188         CDEBUG(D_INODE, "OPEN_INTENT with fid1="DFID", fid2="DFID","
 189                " name='%s' -> mds #%d\n", PFID(&op_data->op_fid1),
 190                PFID(&op_data->op_fid2), op_data->op_name, tgt->ltd_idx);
 191
 192         rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it, flags,
 193                             reqp, cb_blocking, extra_lock_flags);
 194         if (rc != 0)
 195                 return rc;
 196         /*
 197          * Nothing is found, do not access body->fid1 as it is zero and thus
 198          * pointless.
 199          */
 200         if ((it->d.lustre.it_disposition & DISP_LOOKUP_NEG) &&
 201             !(it->d.lustre.it_disposition & DISP_OPEN_CREATE) &&
 202             !(it->d.lustre.it_disposition & DISP_OPEN_OPEN))
 203                 return rc;
 204
 205         body = req_capsule_server_get(&(*reqp)->rq_pill, &RMF_MDT_BODY);
 206         if (body == NULL)
 207                 return -EPROTO;
 208         /*
 209          * Not cross-ref case, just get out of here.
 210          */
 211         if (likely(!(body->valid & OBD_MD_MDS)))
 212                 return 0;
 213
 214         /*
 215          * Okay, MDS has returned success. Probably name has been resolved in
 216          * remote inode.
 217          */
 218         rc = lmv_intent_remote(exp, lmm, lmmsize, it, &op_data->op_fid1, flags,
 219                                reqp, cb_blocking, extra_lock_flags);
 220         if (rc != 0) {
 221                 LASSERT(rc < 0);
 222                 /*
 223                  * This is possible, that some userspace application will try to
 224                  * open file as directory and we will have -ENOTDIR here. As
 225                  * this is normal situation, we should not print error here,
 226                  * only debug info.
 227                  */
 228                 CDEBUG(D_INODE, "Can't handle remote %s: dir "DFID"("DFID"):"
 229                        "%*s: %d\n", LL_IT2STR(it), PFID(&op_data->op_fid2),
 230                        PFID(&op_data->op_fid1), op_data->op_namelen,
 231                        op_data->op_name, rc);
 232                 return rc;
 233         }
 234
 235         return rc;
 236 }
 237
 238 /*
 239  * Handler for: getattr, lookup and revalidate cases.
 240  */
 241 int lmv_intent_lookup(struct obd_export *exp, struct md_op_data *op_data,
 242                       void *lmm, int lmmsize, struct lookup_intent *it,
 243                       int flags, struct ptlrpc_request **reqp,
 244                       ldlm_blocking_callback cb_blocking,
 245                       __u64 extra_lock_flags)
 246 {
 247         struct obd_device      *obd = exp->exp_obd;
 248         struct lmv_obd   *lmv = &obd->u.lmv;
 249         struct lmv_tgt_desc    *tgt = NULL;
 250         struct mdt_body *body;
 251         int                  rc = 0;
 252
 253         tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
 254         if (IS_ERR(tgt))
 255                 return PTR_ERR(tgt);
 256
 257         if (!fid_is_sane(&op_data->op_fid2))
 258                 fid_zero(&op_data->op_fid2);
 259
 260         CDEBUG(D_INODE, "LOOKUP_INTENT with fid1="DFID", fid2="DFID
 261                ", name='%s' -> mds #%d\n", PFID(&op_data->op_fid1),
 262                PFID(&op_data->op_fid2),
 263                op_data->op_name ? op_data->op_name : "<NULL>",
 264                tgt->ltd_idx);
 265
 266         op_data->op_bias &= ~MDS_CROSS_REF;
 267
 268         rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it,
 269                              flags, reqp, cb_blocking, extra_lock_flags);
 270
 271         if (rc < 0 || *reqp == NULL)
 272                 return rc;
 273
 274         /*
 275          * MDS has returned success. Probably name has been resolved in
 276          * remote inode. Let's check this.
 277          */
 278         body = req_capsule_server_get(&(*reqp)->rq_pill, &RMF_MDT_BODY);
 279         if (body == NULL)
 280                 return -EPROTO;
 281         /* Not cross-ref case, just get out of here. */
 282         if (likely(!(body->valid & OBD_MD_MDS)))
 283                 return 0;
 284
 285         rc = lmv_intent_remote(exp, lmm, lmmsize, it, NULL, flags, reqp,
 286                                cb_blocking, extra_lock_flags);
 287
 288         return rc;
 289 }
 290
 291 int lmv_intent_lock(struct obd_export *exp, struct md_op_data *op_data,
 292                     void *lmm, int lmmsize, struct lookup_intent *it,
 293                     int flags, struct ptlrpc_request **reqp,
 294                     ldlm_blocking_callback cb_blocking,
 295                     __u64 extra_lock_flags)
 296 {
 297         struct obd_device *obd = exp->exp_obd;
 298         int             rc;
 299
 300         LASSERT(it != NULL);
 301         LASSERT(fid_is_sane(&op_data->op_fid1));
 302
 303         CDEBUG(D_INODE, "INTENT LOCK '%s' for '%*s' on "DFID"\n",
 304                LL_IT2STR(it), op_data->op_namelen, op_data->op_name,
 305                PFID(&op_data->op_fid1));
 306
 307         rc = lmv_check_connect(obd);
 308         if (rc)
 309                 return rc;
 310
 311         if (it->it_op & (IT_LOOKUP | IT_GETATTR | IT_LAYOUT))
 312                 rc = lmv_intent_lookup(exp, op_data, lmm, lmmsize, it,
 313                                        flags, reqp, cb_blocking,
 314                                        extra_lock_flags);
 315         else if (it->it_op & IT_OPEN)
 316                 rc = lmv_intent_open(exp, op_data, lmm, lmmsize, it,
 317                                      flags, reqp, cb_blocking,
 318                                      extra_lock_flags);
 319         else
 320                 LBUG();
 321         return rc;
 322 }