lustre/lov/lov_lock.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.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * Implementation of cl_lock for LOV layer.
  32  *
  33  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  34  */
  35
  36 #define DEBUG_SUBSYSTEM S_LOV
  37
  38 #include "lov_cl_internal.h"
  39
  40 /** \addtogroup lov
  41  *  @{
  42  */
  43
  44 /*****************************************************************************
  45  *
  46  * Lov lock operations.
  47  *
  48  */
  49
  50 static struct lov_sublock_env *lov_sublock_env_get(const struct lu_env *env,
  51                                                    const struct cl_lock *parent,
  52                                                    struct lov_lock_sub *lls)
  53 {
  54         struct lov_sublock_env *subenv;
  55         struct lov_io          *lio    = lov_env_io(env);
  56         struct cl_io           *io     = lio->lis_cl.cis_io;
  57         struct lov_io_sub      *sub;
  58
  59         subenv = &lov_env_session(env)->ls_subenv;
  60
  61         /*
  62          * FIXME: We tend to use the subio's env & io to call the sublock
  63          * lock operations because osc lock sometimes stores some control
  64          * variables in thread's IO infomation(Now only lockless information).
  65          * However, if the lock's host(object) is different from the object
  66          * for current IO, we have no way to get the subenv and subio because
  67          * they are not initialized at all. As a temp fix, in this case,
  68          * we still borrow the parent's env to call sublock operations.
  69          */
  70         if (!io || !cl_object_same(io->ci_obj, parent->cll_descr.cld_obj)) {
  71                 subenv->lse_env = env;
  72                 subenv->lse_io = io;
  73         } else {
  74                 sub = lov_sub_get(env, lio, lls->sub_index);
  75                 if (!IS_ERR(sub)) {
  76                         subenv->lse_env = sub->sub_env;
  77                         subenv->lse_io  = &sub->sub_io;
  78                 } else {
  79                         subenv = (void *)sub;
  80                 }
  81         }
  82         return subenv;
  83 }
  84
  85 static int lov_sublock_init(const struct lu_env *env,
  86                             const struct cl_lock *parent,
  87                             struct lov_lock_sub *lls)
  88 {
  89         struct lov_sublock_env *subenv;
  90         int result;
  91
  92         ENTRY;
  93
  94         subenv = lov_sublock_env_get(env, parent, lls);
  95         if (!IS_ERR(subenv)) {
  96                 result = cl_lock_init(subenv->lse_env, &lls->sub_lock,
  97                                       subenv->lse_io);
  98         } else {
  99                 /* error occurs. */
 100                 result = PTR_ERR(subenv);
 101         }
 102         RETURN(result);
 103 }
 104
 105 /**
 106  * Creates sub-locks for a given lov_lock for the first time.
 107  *
 108  * Goes through all sub-objects of top-object, and creates sub-locks on every
 109  * sub-object intersecting with top-lock extent. This is complicated by the
 110  * fact that top-lock (that is being created) can be accessed concurrently
 111  * through already created sub-locks (possibly shared with other top-locks).
 112  */
 113 static struct lov_lock *lov_lock_sub_init(const struct lu_env *env,
 114                                           const struct cl_io *io,
 115                                           const struct cl_object *obj,
 116                                           struct cl_lock *lock)
 117 {
 118         struct lov_object *lov = cl2lov(obj);
 119         struct lov_lock *lovlck;
 120         struct lu_extent ext;
 121         loff_t start;
 122         loff_t end;
 123         int result = 0;
 124         int i;
 125         int index;
 126         int nr;
 127
 128         ENTRY;
 129
 130         ext.e_start = cl_offset(obj, lock->cll_descr.cld_start);
 131         if (lock->cll_descr.cld_end == CL_PAGE_EOF)
 132                 ext.e_end = OBD_OBJECT_EOF;
 133         else
 134                 ext.e_end  = cl_offset(obj, lock->cll_descr.cld_end + 1);
 135
 136         nr = 0;
 137         lov_foreach_io_layout(index, lov_env_io(env), &ext) {
 138                 struct lov_layout_raid0 *r0 = lov_r0(lov, index);
 139
 140                 for (i = 0; i < r0->lo_nr; i++) {
 141                         if (likely(r0->lo_sub[i])) {/* spare layout */
 142                                 if (lov_stripe_intersects(lov->lo_lsm, index, i,
 143                                                           &ext, &start, &end))
 144                                         nr++;
 145                                 else if (cl_io_is_trunc(io) &&
 146                                          r0->lo_trunc_stripeno == i)
 147                                         nr++;
 148                         }
 149                 }
 150         }
 151         /**
 152          * Aggressive lock request (from cl_setattr_ost) which asks for
 153          * [eof, -1) lock, could come across uninstantiated layout extent,
 154          * hence a 0 nr is possible.
 155          */
 156
 157         OBD_ALLOC_LARGE(lovlck, offsetof(struct lov_lock, lls_sub[nr]));
 158         if (!lovlck)
 159                 RETURN(ERR_PTR(-ENOMEM));
 160
 161         lovlck->lls_nr = nr;
 162         nr = 0;
 163         lov_foreach_io_layout(index, lov_env_io(env), &ext) {
 164                 struct lov_layout_raid0 *r0 = lov_r0(lov, index);
 165
 166                 for (i = 0; i < r0->lo_nr; ++i) {
 167                         struct lov_lock_sub *lls = &lovlck->lls_sub[nr];
 168                         struct cl_lock_descr *descr = &lls->sub_lock.cll_descr;
 169                         bool intersect = false;
 170
 171                         if (unlikely(!r0->lo_sub[i]))
 172                                 continue;
 173
 174                         intersect = lov_stripe_intersects(lov->lo_lsm, index, i,
 175                                                           &ext, &start, &end);
 176                         if (intersect)
 177                                 goto init_sublock;
 178
 179                         if (cl_io_is_trunc(io) && i == r0->lo_trunc_stripeno)
 180                                 goto init_sublock;
 181
 182                         continue;
 183
 184 init_sublock:
 185                         LASSERT(descr->cld_obj == NULL);
 186                         descr->cld_obj   = lovsub2cl(r0->lo_sub[i]);
 187                         descr->cld_start = cl_index(descr->cld_obj, start);
 188                         descr->cld_end   = cl_index(descr->cld_obj, end);
 189                         descr->cld_mode  = lock->cll_descr.cld_mode;
 190                         descr->cld_gid   = lock->cll_descr.cld_gid;
 191                         descr->cld_enq_flags = lock->cll_descr.cld_enq_flags;
 192
 193                         lls->sub_index = lov_comp_index(index, i);
 194
 195                         /* initialize sub lock */
 196                         result = lov_sublock_init(env, lock, lls);
 197                         if (result < 0)
 198                                 break;
 199
 200                         lls->sub_initialized = 1;
 201                         nr++;
 202                 }
 203         }
 204         LASSERT(ergo(result == 0, nr == lovlck->lls_nr));
 205
 206         if (result != 0) {
 207                 for (i = 0; i < nr; ++i) {
 208                         if (!lovlck->lls_sub[i].sub_initialized)
 209                                 break;
 210
 211                         cl_lock_fini(env, &lovlck->lls_sub[i].sub_lock);
 212                 }
 213
 214                 OBD_FREE_LARGE(lovlck,
 215                                 offsetof(struct lov_lock, lls_sub[nr]));
 216                 lovlck = ERR_PTR(result);
 217         }
 218
 219         RETURN(lovlck);
 220 }
 221
 222 static void lov_lock_fini(const struct lu_env *env,
 223                           struct cl_lock_slice *slice)
 224 {
 225         struct lov_lock *lovlck;
 226         int i;
 227
 228         ENTRY;
 229         lovlck = cl2lov_lock(slice);
 230         for (i = 0; i < lovlck->lls_nr; ++i) {
 231                 LASSERT(!lovlck->lls_sub[i].sub_is_enqueued);
 232                 if (lovlck->lls_sub[i].sub_initialized)
 233                         cl_lock_fini(env, &lovlck->lls_sub[i].sub_lock);
 234         }
 235         OBD_FREE_LARGE(lovlck,
 236                        offsetof(struct lov_lock, lls_sub[lovlck->lls_nr]));
 237         EXIT;
 238 }
 239
 240 /**
 241  * Implementation of cl_lock_operations::clo_enqueue() for lov layer. This
 242  * function is rather subtle, as it enqueues top-lock (i.e., advances top-lock
 243  * state machine from CLS_QUEUING to CLS_ENQUEUED states) by juggling sub-lock
 244  * state machines in the face of sub-locks sharing (by multiple top-locks),
 245  * and concurrent sub-lock cancellations.
 246  */
 247 static int lov_lock_enqueue(const struct lu_env *env,
 248                             const struct cl_lock_slice *slice,
 249                             struct cl_io *io, struct cl_sync_io *anchor)
 250 {
 251         struct cl_lock *lock = slice->cls_lock;
 252         struct lov_lock *lovlck = cl2lov_lock(slice);
 253         int i;
 254         int rc = 0;
 255
 256         ENTRY;
 257
 258         for (i = 0; i < lovlck->lls_nr; ++i) {
 259                 struct lov_lock_sub     *lls = &lovlck->lls_sub[i];
 260                 struct lov_sublock_env  *subenv;
 261
 262                 subenv = lov_sublock_env_get(env, lock, lls);
 263                 if (IS_ERR(subenv)) {
 264                         rc = PTR_ERR(subenv);
 265                         break;
 266                 }
 267
 268                 rc = cl_lock_enqueue(subenv->lse_env, subenv->lse_io,
 269                                      &lls->sub_lock, anchor);
 270                 if (rc != 0)
 271                         break;
 272
 273                 lls->sub_is_enqueued = 1;
 274         }
 275         RETURN(rc);
 276 }
 277
 278 static void lov_lock_cancel(const struct lu_env *env,
 279                             const struct cl_lock_slice *slice)
 280 {
 281         struct cl_lock *lock = slice->cls_lock;
 282         struct lov_lock *lovlck = cl2lov_lock(slice);
 283         int i;
 284
 285         ENTRY;
 286
 287         for (i = 0; i < lovlck->lls_nr; ++i) {
 288                 struct lov_lock_sub *lls = &lovlck->lls_sub[i];
 289                 struct cl_lock *sublock = &lls->sub_lock;
 290                 struct lov_sublock_env *subenv;
 291
 292                 if (!lls->sub_is_enqueued)
 293                         continue;
 294
 295                 lls->sub_is_enqueued = 0;
 296                 subenv = lov_sublock_env_get(env, lock, lls);
 297                 if (!IS_ERR(subenv)) {
 298                         cl_lock_cancel(subenv->lse_env, sublock);
 299                 } else {
 300                         CL_LOCK_DEBUG(D_ERROR, env, slice->cls_lock,
 301                                       "lov_lock_cancel fails with %ld.\n",
 302                                       PTR_ERR(subenv));
 303                 }
 304         }
 305 }
 306
 307 static int lov_lock_print(const struct lu_env *env, void *cookie,
 308                           lu_printer_t p, const struct cl_lock_slice *slice)
 309 {
 310         struct lov_lock *lck = cl2lov_lock(slice);
 311         int i;
 312
 313         (*p)(env, cookie, "%d\n", lck->lls_nr);
 314         for (i = 0; i < lck->lls_nr; ++i) {
 315                 struct lov_lock_sub *sub;
 316
 317                 sub = &lck->lls_sub[i];
 318                 (*p)(env, cookie, "    %d %x: ", i, sub->sub_is_enqueued);
 319                 cl_lock_print(env, cookie, p, &sub->sub_lock);
 320         }
 321         return 0;
 322 }
 323
 324 static const struct cl_lock_operations lov_lock_ops = {
 325         .clo_fini      = lov_lock_fini,
 326         .clo_enqueue   = lov_lock_enqueue,
 327         .clo_cancel    = lov_lock_cancel,
 328         .clo_print     = lov_lock_print
 329 };
 330
 331 int lov_lock_init_composite(const struct lu_env *env, struct cl_object *obj,
 332                             struct cl_lock *lock, const struct cl_io *io)
 333 {
 334         struct lov_lock *lck;
 335         int result = 0;
 336
 337         ENTRY;
 338         lck = lov_lock_sub_init(env, io, obj, lock);
 339         if (!IS_ERR(lck))
 340                 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_lock_ops);
 341         else
 342                 result = PTR_ERR(lck);
 343         RETURN(result);
 344 }
 345
 346 static void lov_empty_lock_fini(const struct lu_env *env,
 347                                 struct cl_lock_slice *slice)
 348 {
 349         struct lov_lock *lck = cl2lov_lock(slice);
 350
 351         OBD_SLAB_FREE_PTR(lck, lov_lock_kmem);
 352 }
 353
 354 static int lov_empty_lock_print(const struct lu_env *env, void *cookie,
 355                         lu_printer_t p, const struct cl_lock_slice *slice)
 356 {
 357         (*p)(env, cookie, "empty\n");
 358         return 0;
 359 }
 360
 361 /* XXX: more methods will be added later. */
 362 static const struct cl_lock_operations lov_empty_lock_ops = {
 363         .clo_fini  = lov_empty_lock_fini,
 364         .clo_print = lov_empty_lock_print
 365 };
 366
 367 int lov_lock_init_empty(const struct lu_env *env, struct cl_object *obj,
 368                         struct cl_lock *lock, const struct cl_io *io)
 369 {
 370         struct lov_lock *lck;
 371         int result = -ENOMEM;
 372
 373         ENTRY;
 374         OBD_SLAB_ALLOC_PTR_GFP(lck, lov_lock_kmem, GFP_NOFS);
 375         if (lck) {
 376                 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_empty_lock_ops);
 377                 result = 0;
 378         }
 379         RETURN(result);
 380 }
 381
 382 /** @} lov */