lustre/osd-zfs/osd_io.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) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2015, 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  * lustre/osd-zfs/osd_io.c
  33  *
  34  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  35  * Author: Mike Pershin <tappro@whamcloud.com>
  36  */
  37
  38 #define DEBUG_SUBSYSTEM S_OSD
  39
  40 #include <lustre_ver.h>
  41 #include <libcfs/libcfs.h>
  42 #include <obd_support.h>
  43 #include <lustre_net.h>
  44 #include <obd.h>
  45 #include <obd_class.h>
  46 #include <lustre_disk.h>
  47 #include <lustre_fid.h>
  48 #include <lustre/lustre_idl.h>  /* LLOG_MIN_CHUNK_SIZE definition */
  49
  50 #include "osd_internal.h"
  51
  52 #include <sys/dnode.h>
  53 #include <sys/dbuf.h>
  54 #include <sys/spa.h>
  55 #include <sys/stat.h>
  56 #include <sys/zap.h>
  57 #include <sys/spa_impl.h>
  58 #include <sys/zfs_znode.h>
  59 #include <sys/dmu_tx.h>
  60 #include <sys/dmu_objset.h>
  61 #include <sys/dsl_prop.h>
  62 #include <sys/sa_impl.h>
  63 #include <sys/txg.h>
  64
  65 static char *osd_zerocopy_tag = "zerocopy";
  66
  67
  68 static void record_start_io(struct osd_device *osd, int rw, int discont_pages)
  69 {
  70         struct obd_histogram *h = osd->od_brw_stats.hist;
  71
  72         if (rw == READ) {
  73                 atomic_inc(&osd->od_r_in_flight);
  74                 lprocfs_oh_tally(&h[BRW_R_RPC_HIST],
  75                                  atomic_read(&osd->od_r_in_flight));
  76                 lprocfs_oh_tally(&h[BRW_R_DISCONT_PAGES], discont_pages);
  77
  78         } else {
  79                 atomic_inc(&osd->od_w_in_flight);
  80                 lprocfs_oh_tally(&h[BRW_W_RPC_HIST],
  81                                  atomic_read(&osd->od_w_in_flight));
  82                 lprocfs_oh_tally(&h[BRW_W_DISCONT_PAGES], discont_pages);
  83
  84         }
  85 }
  86
  87 static void record_end_io(struct osd_device *osd, int rw,
  88                           unsigned long elapsed, int disksize, int npages)
  89 {
  90         struct obd_histogram *h = osd->od_brw_stats.hist;
  91
  92         if (rw == READ) {
  93                 atomic_dec(&osd->od_r_in_flight);
  94                 lprocfs_oh_tally_log2(&h[BRW_R_PAGES], npages);
  95                 if (disksize > 0)
  96                         lprocfs_oh_tally_log2(&h[BRW_R_DISK_IOSIZE], disksize);
  97                 if (elapsed)
  98                         lprocfs_oh_tally_log2(&h[BRW_R_IO_TIME], elapsed);
  99
 100         } else {
 101                 atomic_dec(&osd->od_w_in_flight);
 102                 lprocfs_oh_tally_log2(&h[BRW_W_PAGES], npages);
 103                 if (disksize > 0)
 104                         lprocfs_oh_tally_log2(&h[BRW_W_DISK_IOSIZE], disksize);
 105                 if (elapsed)
 106                         lprocfs_oh_tally_log2(&h[BRW_W_IO_TIME], elapsed);
 107         }
 108 }
 109
 110 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
 111                         struct lu_buf *buf, loff_t *pos)
 112 {
 113         struct osd_object *obj  = osd_dt_obj(dt);
 114         struct osd_device *osd = osd_obj2dev(obj);
 115         uint64_t           old_size;
 116         int                size = buf->lb_len;
 117         int                rc;
 118         unsigned long      start;
 119
 120         LASSERT(dt_object_exists(dt));
 121         LASSERT(obj->oo_db);
 122
 123         start = cfs_time_current();
 124
 125         read_lock(&obj->oo_attr_lock);
 126         old_size = obj->oo_attr.la_size;
 127         read_unlock(&obj->oo_attr_lock);
 128
 129         if (*pos + size > old_size) {
 130                 if (old_size < *pos)
 131                         return 0;
 132                 else
 133                         size = old_size - *pos;
 134         }
 135
 136         record_start_io(osd, READ, 0);
 137
 138         rc = -dmu_read(osd->od_os, obj->oo_db->db_object, *pos, size,
 139                         buf->lb_buf, DMU_READ_PREFETCH);
 140
 141         record_end_io(osd, READ, cfs_time_current() - start, size,
 142                       size >> PAGE_SHIFT);
 143         if (rc == 0) {
 144                 rc = size;
 145                 *pos += size;
 146         }
 147         return rc;
 148 }
 149
 150 static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
 151                                 const struct lu_buf *buf, loff_t pos,
 152                                 struct thandle *th)
 153 {
 154         struct osd_object  *obj  = osd_dt_obj(dt);
 155         struct osd_device  *osd = osd_obj2dev(obj);
 156         struct osd_thandle *oh;
 157         uint64_t            oid;
 158         ENTRY;
 159
 160         oh = container_of0(th, struct osd_thandle, ot_super);
 161
 162         /* in some cases declare can race with creation (e.g. llog)
 163          * and we need to wait till object is initialized. notice
 164          * LOHA_EXISTs is supposed to be the last step in the
 165          * initialization */
 166
 167         /* size change (in dnode) will be declared by dmu_tx_hold_write() */
 168         if (dt_object_exists(dt))
 169                 oid = obj->oo_db->db_object;
 170         else
 171                 oid = DMU_NEW_OBJECT;
 172
 173         /* XXX: we still miss for append declaration support in ZFS
 174          *      -1 means append which is used by llog mostly, llog
 175          *      can grow upto LLOG_MIN_CHUNK_SIZE*8 records */
 176         if (pos == -1)
 177                 pos = max_t(loff_t, 256 * 8 * LLOG_MIN_CHUNK_SIZE,
 178                             obj->oo_attr.la_size + (2 << 20));
 179         dmu_tx_hold_write(oh->ot_tx, oid, pos, buf->lb_len);
 180
 181         /* dt_declare_write() is usually called for system objects, such
 182          * as llog or last_rcvd files. We needn't enforce quota on those
 183          * objects, so always set the lqi_space as 0. */
 184         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 185                                  obj->oo_attr.la_gid, 0, oh, true, NULL,
 186                                  false));
 187 }
 188
 189 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
 190                         const struct lu_buf *buf, loff_t *pos,
 191                         struct thandle *th, int ignore_quota)
 192 {
 193         struct osd_object  *obj  = osd_dt_obj(dt);
 194         struct osd_device  *osd = osd_obj2dev(obj);
 195         struct osd_thandle *oh;
 196         uint64_t            offset = *pos;
 197         int                 rc;
 198
 199         ENTRY;
 200
 201         LASSERT(dt_object_exists(dt));
 202         LASSERT(obj->oo_db);
 203
 204         LASSERT(th != NULL);
 205         oh = container_of0(th, struct osd_thandle, ot_super);
 206
 207         dmu_write(osd->od_os, obj->oo_db->db_object, offset,
 208                 (uint64_t)buf->lb_len, buf->lb_buf, oh->ot_tx);
 209         write_lock(&obj->oo_attr_lock);
 210         if (obj->oo_attr.la_size < offset + buf->lb_len) {
 211                 obj->oo_attr.la_size = offset + buf->lb_len;
 212                 write_unlock(&obj->oo_attr_lock);
 213                 /* osd_object_sa_update() will be copying directly from oo_attr
 214                  * into dbuf.  any update within a single txg will copy the
 215                  * most actual */
 216                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 217                                         &obj->oo_attr.la_size, 8, oh);
 218                 if (unlikely(rc))
 219                         GOTO(out, rc);
 220         } else {
 221                 write_unlock(&obj->oo_attr_lock);
 222         }
 223
 224         *pos += buf->lb_len;
 225         rc = buf->lb_len;
 226
 227 out:
 228         RETURN(rc);
 229 }
 230
 231 /*
 232  * XXX: for the moment I don't want to use lnb_flags for osd-internal
 233  *      purposes as it's not very well defined ...
 234  *      instead I use the lowest bit of the address so that:
 235  *        arc buffer:  .lnb_data = abuf          (arc we loan for write)
 236  *        dbuf buffer: .lnb_data = dbuf | 1      (dbuf we get for read)
 237  *        copy buffer: .lnb_page->mapping = obj (page we allocate for write)
 238  *
 239  *      bzzz, to blame
 240  */
 241 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
 242                         struct niobuf_local *lnb, int npages)
 243 {
 244         struct osd_object *obj  = osd_dt_obj(dt);
 245         struct osd_device *osd = osd_obj2dev(obj);
 246         unsigned long      ptr;
 247         int                i;
 248
 249         LASSERT(dt_object_exists(dt));
 250         LASSERT(obj->oo_db);
 251
 252         for (i = 0; i < npages; i++) {
 253                 if (lnb[i].lnb_page == NULL)
 254                         continue;
 255                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 256                         /* this is anonymous page allocated for copy-write */
 257                         lnb[i].lnb_page->mapping = NULL;
 258                         __free_page(lnb[i].lnb_page);
 259                         atomic_dec(&osd->od_zerocopy_alloc);
 260                 } else {
 261                         /* see comment in osd_bufs_get_read() */
 262                         ptr = (unsigned long)lnb[i].lnb_data;
 263                         if (ptr & 1UL) {
 264                                 ptr &= ~1UL;
 265                                 dmu_buf_rele((void *)ptr, osd_zerocopy_tag);
 266                                 atomic_dec(&osd->od_zerocopy_pin);
 267                         } else if (lnb[i].lnb_data != NULL) {
 268                                 dmu_return_arcbuf(lnb[i].lnb_data);
 269                                 atomic_dec(&osd->od_zerocopy_loan);
 270                         }
 271                 }
 272                 lnb[i].lnb_page = NULL;
 273                 lnb[i].lnb_data = NULL;
 274         }
 275
 276         return 0;
 277 }
 278
 279 static inline struct page *kmem_to_page(void *addr)
 280 {
 281         if (is_vmalloc_addr(addr))
 282                 return vmalloc_to_page(addr);
 283         else
 284                 return virt_to_page(addr);
 285 }
 286
 287 /**
 288  * Prepare buffers for read.
 289  *
 290  * The function maps the range described by \a off and \a len to \a lnb array.
 291  * dmu_buf_hold_array_by_bonus() finds/creates appropriate ARC buffers, then
 292  * we fill \a lnb array with the pages storing ARC buffers. Notice the current
 293  * implementationt passes TRUE to dmu_buf_hold_array_by_bonus() to fill ARC
 294  * buffers with actual data, I/O is done in the conext of osd_bufs_get_read().
 295  * A better implementation would just return the buffers (potentially unfilled)
 296  * and subsequent osd_read_prep() would do I/O for many ranges concurrently.
 297  *
 298  * \param[in] env       environment
 299  * \param[in] obj       object
 300  * \param[in] off       offset in bytes
 301  * \param[in] len       the number of bytes to access
 302  * \param[out] lnb      array of local niobufs pointing to the buffers with data
 303  *
 304  * \retval              0 for success
 305  * \retval              negative error number of failure
 306  */
 307 static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
 308                                 loff_t off, ssize_t len, struct niobuf_local *lnb)
 309 {
 310         struct osd_device *osd = osd_obj2dev(obj);
 311         unsigned long      start = cfs_time_current();
 312         int                rc, i, numbufs, npages = 0;
 313         dmu_buf_t        **dbp;
 314         ENTRY;
 315
 316         record_start_io(osd, READ, 0);
 317
 318         /* grab buffers for read:
 319          * OSD API let us to grab buffers first, then initiate IO(s)
 320          * so that all required IOs will be done in parallel, but at the
 321          * moment DMU doesn't provide us with a method to grab buffers.
 322          * If we discover this is a vital for good performance we
 323          * can get own replacement for dmu_buf_hold_array_by_bonus().
 324          */
 325         while (len > 0) {
 326                 rc = -dmu_buf_hold_array_by_bonus(obj->oo_db, off, len, TRUE,
 327                                                   osd_zerocopy_tag, &numbufs,
 328                                                   &dbp);
 329                 if (unlikely(rc))
 330                         GOTO(err, rc);
 331
 332                 for (i = 0; i < numbufs; i++) {
 333                         int bufoff, tocpy, thispage;
 334                         void *dbf = dbp[i];
 335
 336                         LASSERT(len > 0);
 337
 338                         atomic_inc(&osd->od_zerocopy_pin);
 339
 340                         bufoff = off - dbp[i]->db_offset;
 341                         tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
 342
 343                         /* kind of trick to differentiate dbuf vs. arcbuf */
 344                         LASSERT(((unsigned long)dbp[i] & 1) == 0);
 345                         dbf = (void *) ((unsigned long)dbp[i] | 1);
 346
 347                         while (tocpy > 0) {
 348                                 thispage = PAGE_SIZE;
 349                                 thispage -= bufoff & (PAGE_SIZE - 1);
 350                                 thispage = min(tocpy, thispage);
 351
 352                                 lnb->lnb_rc = 0;
 353                                 lnb->lnb_file_offset = off;
 354                                 lnb->lnb_page_offset = bufoff & ~PAGE_MASK;
 355                                 lnb->lnb_len = thispage;
 356                                 lnb->lnb_page = kmem_to_page(dbp[i]->db_data +
 357                                                              bufoff);
 358                                 /* mark just a single slot: we need this
 359                                  * reference to dbuf to be released once */
 360                                 lnb->lnb_data = dbf;
 361                                 dbf = NULL;
 362
 363                                 tocpy -= thispage;
 364                                 len -= thispage;
 365                                 bufoff += thispage;
 366                                 off += thispage;
 367
 368                                 npages++;
 369                                 lnb++;
 370                         }
 371
 372                         /* steal dbuf so dmu_buf_rele_array() can't release
 373                          * it */
 374                         dbp[i] = NULL;
 375                 }
 376
 377                 dmu_buf_rele_array(dbp, numbufs, osd_zerocopy_tag);
 378         }
 379
 380         record_end_io(osd, READ, cfs_time_current() - start,
 381                       npages * PAGE_SIZE, npages);
 382
 383         RETURN(npages);
 384
 385 err:
 386         LASSERT(rc < 0);
 387         osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
 388         RETURN(rc);
 389 }
 390
 391 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
 392                                 loff_t off, ssize_t len, struct niobuf_local *lnb)
 393 {
 394         struct osd_device *osd = osd_obj2dev(obj);
 395         int                plen, off_in_block, sz_in_block;
 396         int                rc, i = 0, npages = 0;
 397         arc_buf_t         *abuf;
 398         uint32_t           bs;
 399         uint64_t           dummy;
 400         ENTRY;
 401
 402         dmu_object_size_from_db(obj->oo_db, &bs, &dummy);
 403
 404         /*
 405          * currently only full blocks are subject to zerocopy approach:
 406          * so that we're sure nobody is trying to update the same block
 407          */
 408         while (len > 0) {
 409                 LASSERT(npages < PTLRPC_MAX_BRW_PAGES);
 410
 411                 off_in_block = off & (bs - 1);
 412                 sz_in_block = min_t(int, bs - off_in_block, len);
 413
 414                 if (sz_in_block == bs) {
 415                         /* full block, try to use zerocopy */
 416
 417                         abuf = dmu_request_arcbuf(obj->oo_db, bs);
 418                         if (unlikely(abuf == NULL))
 419                                 GOTO(out_err, rc = -ENOMEM);
 420
 421                         atomic_inc(&osd->od_zerocopy_loan);
 422
 423                         /* go over pages arcbuf contains, put them as
 424                          * local niobufs for ptlrpc's bulks */
 425                         while (sz_in_block > 0) {
 426                                 plen = min_t(int, sz_in_block, PAGE_SIZE);
 427
 428                                 lnb[i].lnb_file_offset = off;
 429                                 lnb[i].lnb_page_offset = 0;
 430                                 lnb[i].lnb_len = plen;
 431                                 lnb[i].lnb_rc = 0;
 432                                 if (sz_in_block == bs)
 433                                         lnb[i].lnb_data = abuf;
 434                                 else
 435                                         lnb[i].lnb_data = NULL;
 436
 437                                 /* this one is not supposed to fail */
 438                                 lnb[i].lnb_page = kmem_to_page(abuf->b_data +
 439                                                         off_in_block);
 440                                 LASSERT(lnb[i].lnb_page);
 441
 442                                 lprocfs_counter_add(osd->od_stats,
 443                                                 LPROC_OSD_ZEROCOPY_IO, 1);
 444
 445                                 sz_in_block -= plen;
 446                                 len -= plen;
 447                                 off += plen;
 448                                 off_in_block += plen;
 449                                 i++;
 450                                 npages++;
 451                         }
 452                 } else {
 453                         if (off_in_block == 0 && len < bs &&
 454                                         off + len >= obj->oo_attr.la_size)
 455                                 lprocfs_counter_add(osd->od_stats,
 456                                                 LPROC_OSD_TAIL_IO, 1);
 457
 458                         /* can't use zerocopy, allocate temp. buffers */
 459                         while (sz_in_block > 0) {
 460                                 plen = min_t(int, sz_in_block, PAGE_SIZE);
 461
 462                                 lnb[i].lnb_file_offset = off;
 463                                 lnb[i].lnb_page_offset = 0;
 464                                 lnb[i].lnb_len = plen;
 465                                 lnb[i].lnb_rc = 0;
 466                                 lnb[i].lnb_data = NULL;
 467
 468                                 lnb[i].lnb_page = alloc_page(OSD_GFP_IO);
 469                                 if (unlikely(lnb[i].lnb_page == NULL))
 470                                         GOTO(out_err, rc = -ENOMEM);
 471
 472                                 LASSERT(lnb[i].lnb_page->mapping == NULL);
 473                                 lnb[i].lnb_page->mapping = (void *)obj;
 474
 475                                 atomic_inc(&osd->od_zerocopy_alloc);
 476                                 lprocfs_counter_add(osd->od_stats,
 477                                                 LPROC_OSD_COPY_IO, 1);
 478
 479                                 sz_in_block -= plen;
 480                                 len -= plen;
 481                                 off += plen;
 482                                 i++;
 483                                 npages++;
 484                         }
 485                 }
 486         }
 487
 488         RETURN(npages);
 489
 490 out_err:
 491         osd_bufs_put(env, &obj->oo_dt, lnb, npages);
 492         RETURN(rc);
 493 }
 494
 495 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
 496                         loff_t offset, ssize_t len, struct niobuf_local *lnb,
 497                         int rw)
 498 {
 499         struct osd_object *obj  = osd_dt_obj(dt);
 500         int                rc;
 501
 502         LASSERT(dt_object_exists(dt));
 503         LASSERT(obj->oo_db);
 504
 505         if (rw == 0)
 506                 rc = osd_bufs_get_read(env, obj, offset, len, lnb);
 507         else
 508                 rc = osd_bufs_get_write(env, obj, offset, len, lnb);
 509
 510         return rc;
 511 }
 512
 513 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
 514                         struct niobuf_local *lnb, int npages)
 515 {
 516         struct osd_object *obj = osd_dt_obj(dt);
 517
 518         LASSERT(dt_object_exists(dt));
 519         LASSERT(obj->oo_db);
 520
 521         return 0;
 522 }
 523
 524 static inline uint32_t osd_get_blocksz(struct osd_object *obj)
 525 {
 526         uint32_t blksz;
 527         u_longlong_t unused;
 528
 529         LASSERT(obj->oo_db);
 530
 531         dmu_object_size_from_db(obj->oo_db, &blksz, &unused);
 532         return blksz;
 533 }
 534
 535 static inline uint64_t osd_roundup2blocksz(uint64_t size,
 536                                            uint64_t offset,
 537                                            uint32_t blksz)
 538 {
 539         LASSERT(blksz > 0);
 540
 541         size += offset % blksz;
 542
 543         if (likely(IS_PO2(blksz)))
 544                 return PO2_ROUNDUP_TYPED(size, blksz, uint64_t);
 545
 546         size += blksz - 1;
 547         do_div(size, blksz);
 548         return size * blksz;
 549 }
 550
 551 static int osd_declare_write_commit(const struct lu_env *env,
 552                                     struct dt_object *dt,
 553                                     struct niobuf_local *lnb, int npages,
 554                                     struct thandle *th)
 555 {
 556         struct osd_object  *obj = osd_dt_obj(dt);
 557         struct osd_device  *osd = osd_obj2dev(obj);
 558         struct osd_thandle *oh;
 559         uint64_t            offset = 0;
 560         uint32_t            size = 0;
 561         uint32_t            blksz = osd_get_blocksz(obj);
 562         int                 i, rc, flags = 0;
 563         bool                ignore_quota = false, synced = false;
 564         long long           space = 0;
 565         struct page        *last_page = NULL;
 566         unsigned long       discont_pages = 0;
 567         ENTRY;
 568
 569         LASSERT(dt_object_exists(dt));
 570         LASSERT(obj->oo_db);
 571
 572         LASSERT(lnb);
 573         LASSERT(npages > 0);
 574
 575         oh = container_of0(th, struct osd_thandle, ot_super);
 576
 577         for (i = 0; i < npages; i++) {
 578                 if (last_page && lnb[i].lnb_page->index != (last_page->index + 1))
 579                         ++discont_pages;
 580                 last_page = lnb[i].lnb_page;
 581                 if (lnb[i].lnb_rc)
 582                         /* ENOSPC, network RPC error, etc.
 583                          * We don't want to book space for pages which will be
 584                          * skipped in osd_write_commit(). Hence we skip pages
 585                          * with lnb_rc != 0 here too */
 586                         continue;
 587                 /* ignore quota for the whole request if any page is from
 588                  * client cache or written by root.
 589                  *
 590                  * XXX once we drop the 1.8 client support, the checking
 591                  * for whether page is from cache can be simplified as:
 592                  * !(lnb[i].flags & OBD_BRW_SYNC)
 593                  *
 594                  * XXX we could handle this on per-lnb basis as done by
 595                  * grant. */
 596                 if ((lnb[i].lnb_flags & OBD_BRW_NOQUOTA) ||
 597                     (lnb[i].lnb_flags & (OBD_BRW_FROM_GRANT | OBD_BRW_SYNC)) ==
 598                     OBD_BRW_FROM_GRANT)
 599                         ignore_quota = true;
 600                 if (size == 0) {
 601                         /* first valid lnb */
 602                         offset = lnb[i].lnb_file_offset;
 603                         size = lnb[i].lnb_len;
 604                         continue;
 605                 }
 606                 if (offset + size == lnb[i].lnb_file_offset) {
 607                         /* this lnb is contiguous to the previous one */
 608                         size += lnb[i].lnb_len;
 609                         continue;
 610                 }
 611
 612                 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object,
 613                                   offset, size);
 614                 /* Estimating space to be consumed by a write is rather
 615                  * complicated with ZFS. As a consequence, we don't account for
 616                  * indirect blocks and just use as a rough estimate the worse
 617                  * case where the old space is being held by a snapshot. Quota
 618                  * overrun will be adjusted once the operation is committed, if
 619                  * required. */
 620                 space += osd_roundup2blocksz(size, offset, blksz);
 621
 622                 offset = lnb[i].lnb_file_offset;
 623                 size = lnb[i].lnb_len;
 624         }
 625
 626         if (size) {
 627                 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object,
 628                                   offset, size);
 629                 space += osd_roundup2blocksz(size, offset, blksz);
 630         }
 631
 632         dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 633
 634         oh->ot_write_commit = 1; /* used in osd_trans_start() for fail_loc */
 635
 636         /* backend zfs filesystem might be configured to store multiple data
 637          * copies */
 638         space  *= osd->od_os->os_copies;
 639         space   = toqb(space);
 640         CDEBUG(D_QUOTA, "writing %d pages, reserving %lldK of quota space\n",
 641                npages, space);
 642
 643         record_start_io(osd, WRITE, discont_pages);
 644 retry:
 645         /* acquire quota space if needed */
 646         rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 647                                obj->oo_attr.la_gid, space, oh, true, &flags,
 648                                ignore_quota);
 649
 650         if (!synced && rc == -EDQUOT && (flags & QUOTA_FL_SYNC) != 0) {
 651                 dt_sync(env, th->th_dev);
 652                 synced = true;
 653                 CDEBUG(D_QUOTA, "retry after sync\n");
 654                 flags = 0;
 655                 goto retry;
 656         }
 657
 658         /* we need only to store the overquota flags in the first lnb for
 659          * now, once we support multiple objects BRW, this code needs be
 660          * revised. */
 661         if (flags & QUOTA_FL_OVER_USRQUOTA)
 662                 lnb[0].lnb_flags |= OBD_BRW_OVER_USRQUOTA;
 663         if (flags & QUOTA_FL_OVER_GRPQUOTA)
 664                 lnb[0].lnb_flags |= OBD_BRW_OVER_GRPQUOTA;
 665
 666         RETURN(rc);
 667 }
 668
 669 /**
 670  * Policy to grow ZFS block size by write pattern.
 671  * For sequential write, it grows block size gradually until it reaches the
 672  * maximum blocksize the dataset can support. Otherwise, it will pick a
 673  * a block size by the writing region of this I/O.
 674  */
 675 static int osd_grow_blocksize(struct osd_object *obj, struct osd_thandle *oh,
 676                               uint64_t start, uint64_t end)
 677 {
 678         struct osd_device       *osd = osd_obj2dev(obj);
 679         dmu_buf_impl_t          *db = (dmu_buf_impl_t *)obj->oo_db;
 680         dnode_t                 *dn;
 681         uint32_t                 blksz;
 682         int                      rc = 0;
 683
 684         ENTRY;
 685
 686         DB_DNODE_ENTER(db);
 687         dn = DB_DNODE(db);
 688
 689         if (dn->dn_maxblkid > 0) /* can't change block size */
 690                 GOTO(out, rc);
 691
 692         if (dn->dn_datablksz >= osd->od_max_blksz)
 693                 GOTO(out, rc);
 694
 695         down_write(&obj->oo_guard);
 696
 697         blksz = dn->dn_datablksz;
 698         if (blksz >= osd->od_max_blksz) /* check again after grabbing lock */
 699                 GOTO(out_unlock, rc);
 700
 701         /* now ZFS can support up to 16MB block size, and if the write
 702          * is sequential, it just increases the block size gradually */
 703         if (start <= blksz) { /* sequential */
 704                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz, end);
 705         } else { /* sparse, pick a block size by write region */
 706                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz,
 707                                         end - start);
 708         }
 709
 710         if (!is_power_of_2(blksz))
 711                 blksz = size_roundup_power2(blksz);
 712
 713         if (blksz > dn->dn_datablksz) {
 714                 rc = -dmu_object_set_blocksize(osd->od_os, dn->dn_object,
 715                                                blksz, 0, oh->ot_tx);
 716                 LASSERT(ergo(rc == 0, dn->dn_datablksz >= blksz));
 717                 if (rc < 0)
 718                         CDEBUG(D_INODE, "object "DFID": change block size"
 719                                "%u -> %u error rc = %d\n",
 720                                PFID(lu_object_fid(&obj->oo_dt.do_lu)),
 721                                dn->dn_datablksz, blksz, rc);
 722         }
 723         EXIT;
 724 out_unlock:
 725         up_write(&obj->oo_guard);
 726 out:
 727         DB_DNODE_EXIT(db);
 728         return rc;
 729 }
 730
 731 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 732                         struct niobuf_local *lnb, int npages,
 733                         struct thandle *th)
 734 {
 735         struct osd_object  *obj  = osd_dt_obj(dt);
 736         struct osd_device  *osd = osd_obj2dev(obj);
 737         struct osd_thandle *oh;
 738         uint64_t            new_size = 0;
 739         int                 i, rc = 0;
 740         unsigned long      iosize = 0;
 741         ENTRY;
 742
 743         LASSERT(dt_object_exists(dt));
 744         LASSERT(obj->oo_db);
 745
 746         LASSERT(th != NULL);
 747         oh = container_of0(th, struct osd_thandle, ot_super);
 748
 749         /* adjust block size. Assume the buffers are sorted. */
 750         (void)osd_grow_blocksize(obj, oh, lnb[0].lnb_file_offset,
 751                                  lnb[npages - 1].lnb_file_offset +
 752                                  lnb[npages - 1].lnb_len);
 753         for (i = 0; i < npages; i++) {
 754                 CDEBUG(D_INODE, "write %u bytes at %u\n",
 755                         (unsigned) lnb[i].lnb_len,
 756                         (unsigned) lnb[i].lnb_file_offset);
 757
 758                 if (lnb[i].lnb_rc) {
 759                         /* ENOSPC, network RPC error, etc.
 760                          * Unlike ldiskfs, zfs allocates new blocks on rewrite,
 761                          * so we skip this page if lnb_rc is set to -ENOSPC */
 762                         CDEBUG(D_INODE, "obj "DFID": skipping lnb[%u]: rc=%d\n",
 763                                 PFID(lu_object_fid(&dt->do_lu)), i,
 764                                 lnb[i].lnb_rc);
 765                         continue;
 766                 }
 767
 768                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 769                         dmu_write(osd->od_os, obj->oo_db->db_object,
 770                                 lnb[i].lnb_file_offset, lnb[i].lnb_len,
 771                                 kmap(lnb[i].lnb_page), oh->ot_tx);
 772                         kunmap(lnb[i].lnb_page);
 773                 } else if (lnb[i].lnb_data) {
 774                         LASSERT(((unsigned long)lnb[i].lnb_data & 1) == 0);
 775                         /* buffer loaned for zerocopy, try to use it.
 776                          * notice that dmu_assign_arcbuf() is smart
 777                          * enough to recognize changed blocksize
 778                          * in this case it fallbacks to dmu_write() */
 779                         dmu_assign_arcbuf(obj->oo_db, lnb[i].lnb_file_offset,
 780                                           lnb[i].lnb_data, oh->ot_tx);
 781                         /* drop the reference, otherwise osd_put_bufs()
 782                          * will be releasing it - bad! */
 783                         lnb[i].lnb_data = NULL;
 784                         atomic_dec(&osd->od_zerocopy_loan);
 785                 }
 786
 787                 if (new_size < lnb[i].lnb_file_offset + lnb[i].lnb_len)
 788                         new_size = lnb[i].lnb_file_offset + lnb[i].lnb_len;
 789                 iosize += lnb[i].lnb_len;
 790         }
 791
 792         if (unlikely(new_size == 0)) {
 793                 /* no pages to write, no transno is needed */
 794                 th->th_local = 1;
 795                 /* it is important to return 0 even when all lnb_rc == -ENOSPC
 796                  * since ofd_commitrw_write() retries several times on ENOSPC */
 797                 record_end_io(osd, WRITE, 0, 0, 0);
 798                 RETURN(0);
 799         }
 800
 801         write_lock(&obj->oo_attr_lock);
 802         if (obj->oo_attr.la_size < new_size) {
 803                 obj->oo_attr.la_size = new_size;
 804                 write_unlock(&obj->oo_attr_lock);
 805                 /* osd_object_sa_update() will be copying directly from
 806                  * oo_attr into dbuf. any update within a single txg will copy
 807                  * the most actual */
 808                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 809                                           &obj->oo_attr.la_size, 8, oh);
 810         } else {
 811                 write_unlock(&obj->oo_attr_lock);
 812         }
 813
 814         record_end_io(osd, WRITE, 0, iosize, npages);
 815
 816         RETURN(rc);
 817 }
 818
 819 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 820                         struct niobuf_local *lnb, int npages)
 821 {
 822         struct osd_object *obj  = osd_dt_obj(dt);
 823         int                i;
 824         loff_t             eof;
 825
 826         LASSERT(dt_object_exists(dt));
 827         LASSERT(obj->oo_db);
 828
 829         read_lock(&obj->oo_attr_lock);
 830         eof = obj->oo_attr.la_size;
 831         read_unlock(&obj->oo_attr_lock);
 832
 833         for (i = 0; i < npages; i++) {
 834                 if (unlikely(lnb[i].lnb_rc < 0))
 835                         continue;
 836
 837                 lnb[i].lnb_rc = lnb[i].lnb_len;
 838
 839                 if (lnb[i].lnb_file_offset + lnb[i].lnb_len >= eof) {
 840                         if (eof <= lnb[i].lnb_file_offset)
 841                                 lnb[i].lnb_rc = 0;
 842                         else
 843                                 lnb[i].lnb_rc = eof - lnb[i].lnb_file_offset;
 844
 845                         /* all subsequent rc should be 0 */
 846                         while (++i < npages)
 847                                 lnb[i].lnb_rc = 0;
 848                         break;
 849                 }
 850         }
 851
 852         return 0;
 853 }
 854
 855 /*
 856  * Punch/truncate an object
 857  *
 858  *      IN:     db  - dmu_buf of the object to free data in.
 859  *              off - start of section to free.
 860  *              len - length of section to free (DMU_OBJECT_END => to EOF).
 861  *
 862  *      RETURN: 0 if success
 863  *              error code if failure
 864  *
 865  * The transaction passed to this routine must have
 866  * dmu_tx_hold_sa() and if off < size, dmu_tx_hold_free()
 867  * called and then assigned to a transaction group.
 868  */
 869 static int __osd_object_punch(objset_t *os, dmu_buf_t *db, dmu_tx_t *tx,
 870                                 uint64_t size, uint64_t off, uint64_t len)
 871 {
 872         int rc = 0;
 873
 874         /* Assert that the transaction has been assigned to a
 875            transaction group. */
 876         LASSERT(tx->tx_txg != 0);
 877         /*
 878          * Nothing to do if file already at desired length.
 879          */
 880         if (len == DMU_OBJECT_END && size == off)
 881                 return 0;
 882
 883         if (off < size)
 884                 rc = -dmu_free_range(os, db->db_object, off, len, tx);
 885
 886         return rc;
 887 }
 888
 889 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
 890                         __u64 start, __u64 end, struct thandle *th)
 891 {
 892         struct osd_object  *obj = osd_dt_obj(dt);
 893         struct osd_device  *osd = osd_obj2dev(obj);
 894         struct osd_thandle *oh;
 895         __u64               len;
 896         int                 rc = 0;
 897         ENTRY;
 898
 899         LASSERT(dt_object_exists(dt));
 900         LASSERT(osd_invariant(obj));
 901
 902         LASSERT(th != NULL);
 903         oh = container_of0(th, struct osd_thandle, ot_super);
 904
 905         write_lock(&obj->oo_attr_lock);
 906         /* truncate */
 907         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
 908                 len = DMU_OBJECT_END;
 909         else
 910                 len = end - start;
 911         write_unlock(&obj->oo_attr_lock);
 912
 913         rc = __osd_object_punch(osd->od_os, obj->oo_db, oh->ot_tx,
 914                                 obj->oo_attr.la_size, start, len);
 915         /* set new size */
 916         if (len == DMU_OBJECT_END) {
 917                 write_lock(&obj->oo_attr_lock);
 918                 obj->oo_attr.la_size = start;
 919                 write_unlock(&obj->oo_attr_lock);
 920                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 921                                           &obj->oo_attr.la_size, 8, oh);
 922         }
 923         RETURN(rc);
 924 }
 925
 926 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
 927                         __u64 start, __u64 end, struct thandle *handle)
 928 {
 929         struct osd_object  *obj = osd_dt_obj(dt);
 930         struct osd_device  *osd = osd_obj2dev(obj);
 931         struct osd_thandle *oh;
 932         __u64               len;
 933         ENTRY;
 934
 935         oh = container_of0(handle, struct osd_thandle, ot_super);
 936
 937         read_lock(&obj->oo_attr_lock);
 938         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
 939                 len = DMU_OBJECT_END;
 940         else
 941                 len = end - start;
 942
 943         /* declare we'll free some blocks ... */
 944         if (start < obj->oo_attr.la_size) {
 945                 read_unlock(&obj->oo_attr_lock);
 946                 dmu_tx_hold_free(oh->ot_tx, obj->oo_db->db_object, start, len);
 947         } else {
 948                 read_unlock(&obj->oo_attr_lock);
 949         }
 950
 951         /* ... and we'll modify size attribute */
 952         dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 953
 954         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 955                                  obj->oo_attr.la_gid, 0, oh, true, NULL,
 956                                  false));
 957 }
 958
 959 static int osd_ladvise(const struct lu_env *env, struct dt_object *dt,
 960                        __u64 start, __u64 end, enum lu_ladvise_type advice)
 961 {
 962         int     rc;
 963         ENTRY;
 964
 965         switch (advice) {
 966         default:
 967                 rc = -ENOTSUPP;
 968                 break;
 969         }
 970
 971         RETURN(rc);
 972 }
 973
 974 struct dt_body_operations osd_body_ops = {
 975         .dbo_read                       = osd_read,
 976         .dbo_declare_write              = osd_declare_write,
 977         .dbo_write                      = osd_write,
 978         .dbo_bufs_get                   = osd_bufs_get,
 979         .dbo_bufs_put                   = osd_bufs_put,
 980         .dbo_write_prep                 = osd_write_prep,
 981         .dbo_declare_write_commit       = osd_declare_write_commit,
 982         .dbo_write_commit               = osd_write_commit,
 983         .dbo_read_prep                  = osd_read_prep,
 984         .dbo_declare_punch              = osd_declare_punch,
 985         .dbo_punch                      = osd_punch,
 986         .dbo_ladvise                    = osd_ladvise,
 987 };