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