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, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * lustre/osd-zfs/osd_io.c
  32  *
  33  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  34  * Author: Mike Pershin <tappro@whamcloud.com>
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_OSD
  38
  39 #include <libcfs/libcfs.h>
  40 #include <obd_support.h>
  41 #include <lustre_net.h>
  42 #include <obd.h>
  43 #include <obd_class.h>
  44 #include <lustre_disk.h>
  45 #include <lustre_fid.h>
  46 #include <lustre_quota.h>
  47
  48 #include "osd_internal.h"
  49
  50 #include <sys/dnode.h>
  51 #include <sys/dbuf.h>
  52 #include <sys/spa.h>
  53 #include <sys/stat.h>
  54 #include <sys/zap.h>
  55 #include <sys/spa_impl.h>
  56 #include <sys/zfs_znode.h>
  57 #include <sys/dmu_tx.h>
  58 #include <sys/dmu_objset.h>
  59 #include <sys/dsl_prop.h>
  60 #include <sys/sa_impl.h>
  61 #include <sys/txg.h>
  62
  63 static char osd_0copy_tag[] = "zerocopy";
  64
  65 static void dbuf_set_pending_evict(dmu_buf_t *db)
  66 {
  67         dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
  68         dbi->db_pending_evict = TRUE;
  69 }
  70
  71 static void record_start_io(struct osd_device *osd, int rw, int discont_pages)
  72 {
  73         struct brw_stats *h = &osd->od_brw_stats;
  74
  75         if (rw == READ) {
  76                 atomic_inc(&osd->od_r_in_flight);
  77                 lprocfs_oh_tally_pcpu(&h->bs_hist[BRW_R_RPC_HIST],
  78                                       atomic_read(&osd->od_r_in_flight));
  79                 lprocfs_oh_tally_pcpu(&h->bs_hist[BRW_R_DISCONT_PAGES],
  80                                       discont_pages);
  81         } else {
  82                 atomic_inc(&osd->od_w_in_flight);
  83                 lprocfs_oh_tally_pcpu(&h->bs_hist[BRW_W_RPC_HIST],
  84                                       atomic_read(&osd->od_w_in_flight));
  85                 lprocfs_oh_tally_pcpu(&h->bs_hist[BRW_W_DISCONT_PAGES],
  86                                       discont_pages);
  87         }
  88 }
  89
  90 static void record_end_io(struct osd_device *osd, int rw,
  91                           unsigned long elapsed, int disksize, int npages)
  92 {
  93         struct brw_stats *h = &osd->od_brw_stats;
  94
  95         if (rw == READ)
  96                 atomic_dec(&osd->od_r_in_flight);
  97         else
  98                 atomic_dec(&osd->od_w_in_flight);
  99
 100         lprocfs_oh_tally_log2_pcpu(&h->bs_hist[BRW_R_PAGES + rw], npages);
 101         if (disksize > 0)
 102                 lprocfs_oh_tally_log2_pcpu(&h->bs_hist[BRW_R_DISK_IOSIZE + rw],
 103                                            disksize);
 104         if (elapsed)
 105                 lprocfs_oh_tally_log2_pcpu(&h->bs_hist[BRW_R_IO_TIME + rw],
 106                                             elapsed);
 107 }
 108
 109 static ssize_t __osd_read(const struct lu_env *env, struct dt_object *dt,
 110                           struct lu_buf *buf, loff_t *pos, size_t *size)
 111 {
 112         struct osd_object *obj = osd_dt_obj(dt);
 113         uint64_t old_size;
 114         int rc;
 115
 116         LASSERT(dt_object_exists(dt));
 117         LASSERT(obj->oo_dn);
 118
 119         read_lock(&obj->oo_attr_lock);
 120         old_size = obj->oo_attr.la_size;
 121         read_unlock(&obj->oo_attr_lock);
 122
 123         if (*pos + *size > old_size) {
 124                 if (old_size < *pos)
 125                         return 0;
 126
 127                 *size = old_size - *pos;
 128         }
 129
 130         rc = osd_dmu_read(osd_obj2dev(obj), obj->oo_dn, *pos, *size,
 131                           buf->lb_buf, DMU_READ_PREFETCH);
 132         if (!rc) {
 133                 rc = *size;
 134                 *pos += *size;
 135         }
 136
 137         return rc;
 138 }
 139
 140 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
 141                         struct lu_buf *buf, loff_t *pos)
 142 {
 143         struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
 144         size_t size = buf->lb_len;
 145         hrtime_t start = gethrtime();
 146         s64 delta_ms;
 147         int rc;
 148
 149         record_start_io(osd, READ, 0);
 150         rc = __osd_read(env, dt, buf, pos, &size);
 151         delta_ms = gethrtime() - start;
 152         do_div(delta_ms, NSEC_PER_MSEC);
 153         record_end_io(osd, READ, delta_ms, size, size >> PAGE_SHIFT);
 154
 155         return rc;
 156 }
 157
 158 static inline ssize_t osd_read_no_record(const struct lu_env *env,
 159                                          struct dt_object *dt,
 160                                          struct lu_buf *buf, loff_t *pos)
 161 {
 162         size_t size = buf->lb_len;
 163
 164         return __osd_read(env, dt, buf, pos, &size);
 165 }
 166
 167 static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
 168                                 const struct lu_buf *buf, loff_t pos,
 169                                 struct thandle *th)
 170 {
 171         struct osd_object  *obj  = osd_dt_obj(dt);
 172         struct osd_device  *osd = osd_obj2dev(obj);
 173         struct osd_thandle *oh;
 174         uint64_t            oid;
 175         ENTRY;
 176
 177         oh = container_of(th, struct osd_thandle, ot_super);
 178
 179         /* in some cases declare can race with creation (e.g. llog)
 180          * and we need to wait till object is initialized. notice
 181          * LOHA_EXISTs is supposed to be the last step in the
 182          * initialization */
 183
 184         /* size change (in dnode) will be declared by dmu_tx_hold_write() */
 185         if (dt_object_exists(dt))
 186                 oid = obj->oo_dn->dn_object;
 187         else
 188                 oid = DMU_NEW_OBJECT;
 189
 190         /* XXX: we still miss for append declaration support in ZFS
 191          *      -1 means append which is used by llog mostly, llog
 192          *      can grow upto LLOG_MIN_CHUNK_SIZE*8 records */
 193         if (pos == -1)
 194                 pos = max_t(loff_t, 256 * 8 * LLOG_MIN_CHUNK_SIZE,
 195                             obj->oo_attr.la_size + (2 << 20));
 196         osd_tx_hold_write(oh->ot_tx, oid, obj->oo_dn, pos, buf->lb_len);
 197
 198         /* dt_declare_write() is usually called for system objects, such
 199          * as llog or last_rcvd files. We needn't enforce quota on those
 200          * objects, so always set the lqi_space as 0. */
 201         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 202                                  obj->oo_attr.la_gid, obj->oo_attr.la_projid,
 203                                  0, oh, NULL, OSD_QID_BLK));
 204 }
 205
 206 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
 207                         const struct lu_buf *buf, loff_t *pos,
 208                          struct thandle *th)
 209 {
 210         struct osd_object  *obj  = osd_dt_obj(dt);
 211         struct osd_device  *osd = osd_obj2dev(obj);
 212         struct osd_thandle *oh;
 213         uint64_t            offset = *pos;
 214         int                 rc;
 215
 216         ENTRY;
 217
 218         LASSERT(dt_object_exists(dt));
 219         LASSERT(obj->oo_dn);
 220
 221         LASSERT(th != NULL);
 222         oh = container_of(th, struct osd_thandle, ot_super);
 223
 224         down_read(&obj->oo_guard);
 225         if (obj->oo_destroyed)
 226                 GOTO(out, rc = -ENOENT);
 227
 228         osd_dmu_write(osd, obj->oo_dn, offset, (uint64_t)buf->lb_len,
 229                       buf->lb_buf, oh->ot_tx);
 230         write_lock(&obj->oo_attr_lock);
 231         if (obj->oo_attr.la_size < offset + buf->lb_len) {
 232                 obj->oo_attr.la_size = offset + buf->lb_len;
 233                 write_unlock(&obj->oo_attr_lock);
 234                 /* osd_object_sa_update() will be copying directly from oo_attr
 235                  * into dbuf.  any update within a single txg will copy the
 236                  * most actual */
 237                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 238                                         &obj->oo_attr.la_size, 8, oh);
 239                 if (unlikely(rc))
 240                         GOTO(out, rc);
 241         } else {
 242                 write_unlock(&obj->oo_attr_lock);
 243         }
 244
 245         *pos += buf->lb_len;
 246         rc = buf->lb_len;
 247
 248 out:
 249         up_read(&obj->oo_guard);
 250         RETURN(rc);
 251 }
 252
 253 /*
 254  * XXX: for the moment I don't want to use lnb_flags for osd-internal
 255  *      purposes as it's not very well defined ...
 256  *      instead I use the lowest bit of the address so that:
 257  *        arc buffer:  .lnb_data = abuf          (arc we loan for write)
 258  *        dbuf buffer: .lnb_data = dbuf | 1      (dbuf we get for read)
 259  *        copy buffer: .lnb_page->mapping = obj (page we allocate for write)
 260  *
 261  *      bzzz, to blame
 262  */
 263 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
 264                         struct niobuf_local *lnb, int npages)
 265 {
 266         struct osd_object *obj  = osd_dt_obj(dt);
 267         struct osd_device *osd = osd_obj2dev(obj);
 268         unsigned long      ptr;
 269         int                i;
 270
 271         LASSERT(dt_object_exists(dt));
 272         LASSERT(obj->oo_dn);
 273
 274         for (i = 0; i < npages; i++) {
 275                 if (lnb[i].lnb_page == NULL)
 276                         continue;
 277                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 278                         /* this is anonymous page allocated for copy-write */
 279                         lnb[i].lnb_page->mapping = NULL;
 280                         __free_page(lnb[i].lnb_page);
 281                         atomic_dec(&osd->od_zerocopy_alloc);
 282                 } else {
 283                         /* see comment in osd_bufs_get_read() */
 284                         ptr = (unsigned long)lnb[i].lnb_data;
 285                         if (ptr & 1UL) {
 286                                 ptr &= ~1UL;
 287                                 dmu_buf_rele((void *)ptr, osd_0copy_tag);
 288                                 atomic_dec(&osd->od_zerocopy_pin);
 289                         } else if (lnb[i].lnb_data != NULL) {
 290                                 int j, apages, abufsz;
 291                                 abufsz = arc_buf_size(lnb[i].lnb_data);
 292                                 apages = abufsz >> PAGE_SHIFT;
 293                                 /* these references to pages must be invalidated
 294                                  * to prevent access in osd_bufs_put() */
 295                                 for (j = 0; j < apages; j++)
 296                                         lnb[i + j].lnb_page = NULL;
 297                                 dmu_return_arcbuf(lnb[i].lnb_data);
 298                                 atomic_dec(&osd->od_zerocopy_loan);
 299                         }
 300                 }
 301                 lnb[i].lnb_page = NULL;
 302                 lnb[i].lnb_data = NULL;
 303         }
 304
 305         return 0;
 306 }
 307
 308 static inline struct page *kmem_to_page(void *addr)
 309 {
 310         LASSERT(!((unsigned long)addr & ~PAGE_MASK));
 311         if (is_vmalloc_addr(addr))
 312                 return vmalloc_to_page(addr);
 313         else
 314                 return virt_to_page(addr);
 315 }
 316
 317 /**
 318  * Prepare buffers for read.
 319  *
 320  * The function maps the range described by \a off and \a len to \a lnb array.
 321  * dmu_buf_hold_array_by_bonus() finds/creates appropriate ARC buffers, then
 322  * we fill \a lnb array with the pages storing ARC buffers. Notice the current
 323  * implementationt passes TRUE to dmu_buf_hold_array_by_bonus() to fill ARC
 324  * buffers with actual data, I/O is done in the conext of osd_bufs_get_read().
 325  * A better implementation would just return the buffers (potentially unfilled)
 326  * and subsequent osd_read_prep() would do I/O for many ranges concurrently.
 327  *
 328  * \param[in] env       environment
 329  * \param[in] obj       object
 330  * \param[in] off       offset in bytes
 331  * \param[in] len       the number of bytes to access
 332  * \param[out] lnb      array of local niobufs pointing to the buffers with data
 333  *
 334  * \retval              0 for success
 335  * \retval              negative error number of failure
 336  */
 337 static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
 338                              loff_t off, ssize_t len, struct niobuf_local *lnb,
 339                              int maxlnb)
 340 {
 341         struct osd_device *osd = osd_obj2dev(obj);
 342         int rc, i, numbufs, npages = 0, drop_cache = 0;
 343         hrtime_t start = gethrtime();
 344         dmu_buf_t **dbp;
 345         s64 delta_ms;
 346
 347         ENTRY;
 348         record_start_io(osd, READ, 0);
 349
 350         if (obj->oo_attr.la_size >= osd->od_readcache_max_filesize)
 351                 drop_cache = 1;
 352
 353         /* grab buffers for read:
 354          * OSD API let us to grab buffers first, then initiate IO(s)
 355          * so that all required IOs will be done in parallel, but at the
 356          * moment DMU doesn't provide us with a method to grab buffers.
 357          * If we discover this is a vital for good performance we
 358          * can get own replacement for dmu_buf_hold_array_by_bonus().
 359          */
 360         while (len > 0 &&
 361                (obj->oo_dn->dn_datablkshift != 0 ||
 362                 off < obj->oo_dn->dn_datablksz)) {
 363                 if (obj->oo_dn->dn_datablkshift == 0 &&
 364                     off + len > obj->oo_dn->dn_datablksz)
 365                         len = obj->oo_dn->dn_datablksz - off;
 366
 367                 dbp = NULL;
 368                 if (unlikely(npages >= maxlnb))
 369                         GOTO(err, rc = -EOVERFLOW);
 370
 371                 rc = -dmu_buf_hold_array_by_bonus(&obj->oo_dn->dn_bonus->db,
 372                                                   off, len, TRUE, osd_0copy_tag,
 373                                                   &numbufs, &dbp);
 374                 if (unlikely(rc))
 375                         GOTO(err, rc);
 376
 377                 for (i = 0; i < numbufs; i++) {
 378                         int bufoff, tocpy, thispage;
 379                         void *dbf = dbp[i];
 380
 381                         LASSERT(len > 0);
 382
 383                         atomic_inc(&osd->od_zerocopy_pin);
 384
 385                         bufoff = off - dbp[i]->db_offset;
 386                         tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
 387
 388                         /* kind of trick to differentiate dbuf vs. arcbuf */
 389                         LASSERT(((unsigned long)dbp[i] & 1) == 0);
 390                         dbf = (void *) ((unsigned long)dbp[i] | 1);
 391
 392                         while (tocpy > 0) {
 393                                 if (unlikely(npages >= maxlnb))
 394                                         GOTO(err, rc = -EOVERFLOW);
 395
 396                                 thispage = PAGE_SIZE;
 397                                 thispage -= bufoff & (PAGE_SIZE - 1);
 398                                 thispage = min(tocpy, thispage);
 399
 400                                 lnb->lnb_rc = 0;
 401                                 lnb->lnb_file_offset = off;
 402                                 lnb->lnb_page_offset = bufoff & ~PAGE_MASK;
 403                                 lnb->lnb_len = thispage;
 404                                 lnb->lnb_page = kmem_to_page(dbp[i]->db_data +
 405                                                              bufoff);
 406                                 /* mark just a single slot: we need this
 407                                  * reference to dbuf to be released once */
 408                                 lnb->lnb_data = dbf;
 409                                 dbf = NULL;
 410
 411                                 tocpy -= thispage;
 412                                 len -= thispage;
 413                                 bufoff += thispage;
 414                                 off += thispage;
 415
 416                                 npages++;
 417                                 lnb++;
 418                         }
 419
 420                         if (drop_cache)
 421                                 dbuf_set_pending_evict(dbp[i]);
 422
 423                         /* steal dbuf so dmu_buf_rele_array() can't release
 424                          * it */
 425                         dbp[i] = NULL;
 426                 }
 427
 428                 dmu_buf_rele_array(dbp, numbufs, osd_0copy_tag);
 429         }
 430
 431         delta_ms = gethrtime() - start;
 432         do_div(delta_ms, NSEC_PER_MSEC);
 433         record_end_io(osd, READ, delta_ms, npages * PAGE_SIZE, npages);
 434
 435         RETURN(npages);
 436
 437 err:
 438         LASSERT(rc < 0);
 439         if (dbp)
 440                 dmu_buf_rele_array(dbp, numbufs, osd_0copy_tag);
 441         osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
 442         RETURN(rc);
 443 }
 444
 445 static inline arc_buf_t *osd_request_arcbuf(dnode_t *dn, size_t bs)
 446 {
 447         arc_buf_t *abuf;
 448
 449         abuf = dmu_request_arcbuf(&dn->dn_bonus->db, bs);
 450         if (unlikely(!abuf))
 451                 return ERR_PTR(-ENOMEM);
 452
 453 #if ZFS_VERSION_CODE < OBD_OCD_VERSION(0, 7, 0, 0)
 454         /**
 455          * ZFS prior to 0.7.0 doesn't guarantee PAGE_SIZE alignment for zio
 456          * blocks smaller than (PAGE_SIZE << 2). This poses a problem of
 457          * setting up page array for RDMA transfer. See LU-9305.
 458          */
 459         if ((unsigned long)abuf->b_data & ~PAGE_MASK) {
 460                 dmu_return_arcbuf(abuf);
 461                 return NULL;
 462         }
 463 #endif
 464
 465         return abuf;
 466 }
 467
 468 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
 469                               loff_t off, ssize_t len, struct niobuf_local *lnb,
 470                               int maxlnb)
 471 {
 472         struct osd_device *osd = osd_obj2dev(obj);
 473         int                poff, plen, off_in_block, sz_in_block;
 474         int                rc, i = 0, npages = 0;
 475         dnode_t *dn = obj->oo_dn;
 476         arc_buf_t *abuf;
 477         uint32_t bs = dn->dn_datablksz;
 478         ENTRY;
 479
 480         /*
 481          * currently only full blocks are subject to zerocopy approach:
 482          * so that we're sure nobody is trying to update the same block
 483          */
 484         while (len > 0) {
 485                 if (unlikely(npages >= maxlnb))
 486                         GOTO(out_err, rc = -EOVERFLOW);
 487
 488                 off_in_block = off & (bs - 1);
 489                 sz_in_block = min_t(int, bs - off_in_block, len);
 490
 491                 abuf = NULL;
 492                 if (sz_in_block == bs) {
 493                         /* full block, try to use zerocopy */
 494                         abuf = osd_request_arcbuf(dn, bs);
 495                         if (unlikely(IS_ERR(abuf)))
 496                                 GOTO(out_err, rc = PTR_ERR(abuf));
 497                 }
 498
 499                 if (abuf != NULL) {
 500                         atomic_inc(&osd->od_zerocopy_loan);
 501
 502                         /* go over pages arcbuf contains, put them as
 503                          * local niobufs for ptlrpc's bulks */
 504                         while (sz_in_block > 0) {
 505                                 plen = min_t(int, sz_in_block, PAGE_SIZE);
 506
 507                                 if (unlikely(npages >= maxlnb))
 508                                         GOTO(out_err, rc = -EOVERFLOW);
 509
 510                                 lnb[i].lnb_file_offset = off;
 511                                 lnb[i].lnb_page_offset = 0;
 512                                 lnb[i].lnb_len = plen;
 513                                 lnb[i].lnb_rc = 0;
 514                                 if (sz_in_block == bs)
 515                                         lnb[i].lnb_data = abuf;
 516                                 else
 517                                         lnb[i].lnb_data = NULL;
 518
 519                                 /* this one is not supposed to fail */
 520                                 lnb[i].lnb_page = kmem_to_page(abuf->b_data +
 521                                                         off_in_block);
 522                                 LASSERT(lnb[i].lnb_page);
 523
 524                                 lprocfs_counter_add(osd->od_stats,
 525                                                 LPROC_OSD_ZEROCOPY_IO, 1);
 526
 527                                 sz_in_block -= plen;
 528                                 len -= plen;
 529                                 off += plen;
 530                                 off_in_block += plen;
 531                                 i++;
 532                                 npages++;
 533                         }
 534                 } else {
 535                         if (off_in_block == 0 && len < bs &&
 536                                         off + len >= obj->oo_attr.la_size)
 537                                 lprocfs_counter_add(osd->od_stats,
 538                                                 LPROC_OSD_TAIL_IO, 1);
 539
 540                         /* can't use zerocopy, allocate temp. buffers */
 541                         poff = off & (PAGE_SIZE - 1);
 542                         while (sz_in_block > 0) {
 543                                 plen = min_t(int, poff + sz_in_block,
 544                                              PAGE_SIZE);
 545                                 plen -= poff;
 546
 547                                 if (unlikely(npages >= maxlnb))
 548                                         GOTO(out_err, rc = -EOVERFLOW);
 549
 550                                 lnb[i].lnb_file_offset = off;
 551                                 lnb[i].lnb_page_offset = poff;
 552                                 poff = 0;
 553
 554                                 lnb[i].lnb_len = plen;
 555                                 lnb[i].lnb_rc = 0;
 556                                 lnb[i].lnb_data = NULL;
 557
 558                                 lnb[i].lnb_page = alloc_page(OSD_GFP_IO);
 559                                 if (unlikely(lnb[i].lnb_page == NULL))
 560                                         GOTO(out_err, rc = -ENOMEM);
 561
 562                                 LASSERT(lnb[i].lnb_page->mapping == NULL);
 563                                 lnb[i].lnb_page->mapping = (void *)obj;
 564
 565                                 atomic_inc(&osd->od_zerocopy_alloc);
 566                                 lprocfs_counter_add(osd->od_stats,
 567                                                 LPROC_OSD_COPY_IO, 1);
 568
 569                                 sz_in_block -= plen;
 570                                 len -= plen;
 571                                 off += plen;
 572                                 i++;
 573                                 npages++;
 574                         }
 575                 }
 576         }
 577
 578         RETURN(npages);
 579
 580 out_err:
 581         osd_bufs_put(env, &obj->oo_dt, lnb, npages);
 582         RETURN(rc);
 583 }
 584
 585 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
 586                         loff_t offset, ssize_t len, struct niobuf_local *lnb,
 587                         int maxlnb, enum dt_bufs_type rw)
 588 {
 589         struct osd_object *obj  = osd_dt_obj(dt);
 590         int                rc;
 591
 592         down_read(&obj->oo_guard);
 593
 594         if (unlikely(!dt_object_exists(dt) || obj->oo_destroyed))
 595                 GOTO(out, rc = -ENOENT);
 596
 597         if (rw & DT_BUFS_TYPE_WRITE)
 598                 rc = osd_bufs_get_write(env, obj, offset, len, lnb, maxlnb);
 599         else
 600                 rc = osd_bufs_get_read(env, obj, offset, len, lnb, maxlnb);
 601
 602 out:
 603         up_read(&obj->oo_guard);
 604         return rc;
 605 }
 606
 607 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
 608                         struct niobuf_local *lnb, int npages)
 609 {
 610         struct osd_object *obj = osd_dt_obj(dt);
 611
 612         LASSERT(dt_object_exists(dt));
 613         LASSERT(obj->oo_dn);
 614
 615         return 0;
 616 }
 617
 618 static inline uint64_t osd_roundup2blocksz(uint64_t size,
 619                                            uint64_t offset,
 620                                            uint32_t blksz)
 621 {
 622         LASSERT(blksz > 0);
 623
 624         size += offset % blksz;
 625
 626         if (likely(is_power_of_2(blksz)))
 627                 return round_up(size, blksz);
 628         else
 629                 return DIV_ROUND_UP_ULL(size, blksz) * blksz;
 630 }
 631
 632 static int osd_declare_write_commit(const struct lu_env *env,
 633                                     struct dt_object *dt,
 634                                     struct niobuf_local *lnb, int npages,
 635                                     struct thandle *th)
 636 {
 637         struct osd_object  *obj = osd_dt_obj(dt);
 638         struct osd_device  *osd = osd_obj2dev(obj);
 639         struct osd_thandle *oh;
 640         uint64_t            offset = 0;
 641         uint32_t            size = 0;
 642         uint32_t blksz = obj->oo_dn->dn_datablksz;
 643         int                 i, rc;
 644         bool synced = false;
 645         long long           space = 0;
 646         struct page        *last_page = NULL;
 647         unsigned long       discont_pages = 0;
 648         enum osd_quota_local_flags local_flags = 0;
 649         enum osd_qid_declare_flags declare_flags = OSD_QID_BLK;
 650         ENTRY;
 651
 652         LASSERT(dt_object_exists(dt));
 653         LASSERT(obj->oo_dn);
 654
 655         LASSERT(lnb);
 656         LASSERT(npages > 0);
 657
 658         oh = container_of(th, struct osd_thandle, ot_super);
 659
 660         for (i = 0; i < npages; i++) {
 661                 if (last_page && lnb[i].lnb_page->index != (last_page->index + 1))
 662                         ++discont_pages;
 663                 last_page = lnb[i].lnb_page;
 664                 if (lnb[i].lnb_rc)
 665                         /* ENOSPC, network RPC error, etc.
 666                          * We don't want to book space for pages which will be
 667                          * skipped in osd_write_commit(). Hence we skip pages
 668                          * with lnb_rc != 0 here too */
 669                         continue;
 670                 /* ignore quota for the whole request if any page is from
 671                  * client cache or written by root.
 672                  *
 673                  * XXX we could handle this on per-lnb basis as done by
 674                  * grant. */
 675                 if ((lnb[i].lnb_flags & OBD_BRW_NOQUOTA) ||
 676                     (lnb[i].lnb_flags & OBD_BRW_SYS_RESOURCE) ||
 677                     !(lnb[i].lnb_flags & OBD_BRW_SYNC))
 678                         declare_flags |= OSD_QID_FORCE;
 679
 680                 if (size == 0) {
 681                         /* first valid lnb */
 682                         offset = lnb[i].lnb_file_offset;
 683                         size = lnb[i].lnb_len;
 684                         continue;
 685                 }
 686                 if (offset + size == lnb[i].lnb_file_offset) {
 687                         /* this lnb is contiguous to the previous one */
 688                         size += lnb[i].lnb_len;
 689                         continue;
 690                 }
 691
 692                 osd_tx_hold_write(oh->ot_tx, obj->oo_dn->dn_object,
 693                                   obj->oo_dn, offset, size);
 694                 /* Estimating space to be consumed by a write is rather
 695                  * complicated with ZFS. As a consequence, we don't account for
 696                  * indirect blocks and just use as a rough estimate the worse
 697                  * case where the old space is being held by a snapshot. Quota
 698                  * overrun will be adjusted once the operation is committed, if
 699                  * required. */
 700                 space += osd_roundup2blocksz(size, offset, blksz);
 701
 702                 offset = lnb[i].lnb_file_offset;
 703                 size = lnb[i].lnb_len;
 704         }
 705
 706         if (size) {
 707                 osd_tx_hold_write(oh->ot_tx, obj->oo_dn->dn_object, obj->oo_dn,
 708                                   offset, size);
 709                 space += osd_roundup2blocksz(size, offset, blksz);
 710         }
 711
 712         /* backend zfs filesystem might be configured to store multiple data
 713          * copies */
 714         space  *= osd->od_os->os_copies;
 715         space   = toqb(space);
 716         CDEBUG(D_QUOTA, "writing %d pages, reserving %lldK of quota space\n",
 717                npages, space);
 718
 719         record_start_io(osd, WRITE, discont_pages);
 720 retry:
 721         /* acquire quota space if needed */
 722         rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 723                                obj->oo_attr.la_gid, obj->oo_attr.la_projid,
 724                                space, oh, &local_flags, declare_flags);
 725
 726         if (!synced && rc == -EDQUOT &&
 727             (local_flags & QUOTA_FL_SYNC) != 0) {
 728                 dt_sync(env, th->th_dev);
 729                 synced = true;
 730                 CDEBUG(D_QUOTA, "retry after sync\n");
 731                 local_flags = 0;
 732                 goto retry;
 733         }
 734
 735         /* we need only to store the overquota flags in the first lnb for
 736          * now, once we support multiple objects BRW, this code needs be
 737          * revised. */
 738         if (local_flags & QUOTA_FL_OVER_USRQUOTA)
 739                 lnb[0].lnb_flags |= OBD_BRW_OVER_USRQUOTA;
 740         if (local_flags & QUOTA_FL_OVER_GRPQUOTA)
 741                 lnb[0].lnb_flags |= OBD_BRW_OVER_GRPQUOTA;
 742 #ifdef ZFS_PROJINHERIT
 743         if (local_flags & QUOTA_FL_OVER_PRJQUOTA)
 744                 lnb[0].lnb_flags |= OBD_BRW_OVER_PRJQUOTA;
 745 #endif
 746
 747         RETURN(rc);
 748 }
 749
 750 /**
 751  * Policy to grow ZFS block size by write pattern.
 752  * For sequential write, it grows block size gradually until it reaches the
 753  * maximum blocksize the dataset can support. Otherwise, it will pick a
 754  * a block size by the writing region of this I/O.
 755  */
 756 static int osd_grow_blocksize(struct osd_object *obj, struct osd_thandle *oh,
 757                               uint64_t start, uint64_t end)
 758 {
 759         struct osd_device       *osd = osd_obj2dev(obj);
 760         dnode_t *dn = obj->oo_dn;
 761         uint32_t                 blksz;
 762         int                      rc = 0;
 763
 764         ENTRY;
 765
 766         if (dn->dn_maxblkid > 0) /* can't change block size */
 767                 GOTO(out, rc);
 768
 769         if (dn->dn_datablksz >= osd->od_max_blksz)
 770                 GOTO(out, rc);
 771
 772         down_write(&obj->oo_guard);
 773
 774         blksz = dn->dn_datablksz;
 775         if (blksz >= osd->od_max_blksz) /* check again after grabbing lock */
 776                 GOTO(out_unlock, rc);
 777
 778         /* now ZFS can support up to 16MB block size, and if the write
 779          * is sequential, it just increases the block size gradually */
 780         if (start <= blksz) { /* sequential */
 781                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz, end);
 782         } else { /* sparse, pick a block size by write region */
 783                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz,
 784                                         end - start);
 785         }
 786
 787         if (!is_power_of_2(blksz))
 788                 blksz = size_roundup_power2(blksz);
 789
 790         if (blksz > dn->dn_datablksz) {
 791                 rc = -dmu_object_set_blocksize(osd->od_os, dn->dn_object,
 792                                                blksz, 0, oh->ot_tx);
 793                 LASSERT(ergo(rc == 0, dn->dn_datablksz >= blksz));
 794                 if (rc < 0)
 795                         CDEBUG(D_INODE, "object "DFID": change block size"
 796                                "%u -> %u error rc = %d\n",
 797                                PFID(lu_object_fid(&obj->oo_dt.do_lu)),
 798                                dn->dn_datablksz, blksz, rc);
 799         }
 800         EXIT;
 801 out_unlock:
 802         up_write(&obj->oo_guard);
 803 out:
 804         return rc;
 805 }
 806
 807 static void osd_evict_dbufs_after_write(struct osd_object *obj,
 808                                         loff_t off, ssize_t len)
 809 {
 810         dmu_buf_t **dbp;
 811         int i, rc, numbufs;
 812
 813         rc = -dmu_buf_hold_array_by_bonus(&obj->oo_dn->dn_bonus->db, off, len,
 814                                           TRUE, osd_0copy_tag, &numbufs, &dbp);
 815         if (unlikely(rc))
 816                 return;
 817
 818         for (i = 0; i < numbufs; i++)
 819                 dbuf_set_pending_evict(dbp[i]);
 820
 821         dmu_buf_rele_array(dbp, numbufs, osd_0copy_tag);
 822 }
 823
 824 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 825                         struct niobuf_local *lnb, int npages,
 826                         struct thandle *th, __u64 user_size)
 827 {
 828         struct osd_object  *obj  = osd_dt_obj(dt);
 829         struct osd_device  *osd = osd_obj2dev(obj);
 830         struct osd_thandle *oh;
 831         uint64_t            new_size = 0;
 832         int                 i, abufsz, rc = 0, drop_cache = 0;
 833         unsigned long      iosize = 0;
 834         ENTRY;
 835
 836         LASSERT(dt_object_exists(dt));
 837         LASSERT(obj->oo_dn);
 838
 839         LASSERT(th != NULL);
 840         oh = container_of(th, struct osd_thandle, ot_super);
 841
 842         /* adjust block size. Assume the buffers are sorted. */
 843         (void)osd_grow_blocksize(obj, oh, lnb[0].lnb_file_offset,
 844                                  lnb[npages - 1].lnb_file_offset +
 845                                  lnb[npages - 1].lnb_len);
 846
 847         if (obj->oo_attr.la_size >= osd->od_readcache_max_filesize ||
 848             lnb[npages - 1].lnb_file_offset + lnb[npages - 1].lnb_len >=
 849             osd->od_readcache_max_filesize)
 850                 drop_cache = 1;
 851
 852         if (OBD_FAIL_CHECK(OBD_FAIL_OST_MAPBLK_ENOSPC))
 853                 RETURN(-ENOSPC);
 854
 855         /* if la_size is already bigger than specified user_size,
 856          * ignore user_size
 857          */
 858         if (obj->oo_attr.la_size > user_size)
 859                 user_size = 0;
 860
 861         /* LU-8791: take oo_guard to avoid the deadlock that changing block
 862          * size and assigning arcbuf take place at the same time.
 863          *
 864          * Thread 1:
 865          * osd_write_commit()
 866          *  -> osd_grow_blocksize() with osd_object::oo_guard held
 867          *   -> dmu_object_set_blocksize()
 868          *    -> dnode_set_blksz(), with dnode_t::dn_struct_rwlock
 869          *       write lock held
 870          *     -> dbuf_new_size()
 871          *      -> dmu_buf_will_dirty()
 872          *       -> dbuf_read()
 873          *        -> wait for the dbuf state to change
 874          * Thread 2:
 875          * osd_write_commit()
 876          *  -> dmu_assign_arcbuf()
 877          *   -> dbuf_assign_arcbuf(), set dbuf state to DB_FILL
 878          *    -> dbuf_dirty()
 879          *     -> try to hold the read lock of dnode_t::dn_struct_rwlock
 880          *
 881          * By taking the read lock, it can avoid thread 2 to enter into the
 882          * critical section of assigning the arcbuf, while thread 1 is
 883          * changing the block size.
 884          */
 885         down_read(&obj->oo_guard);
 886         if (obj->oo_destroyed) {
 887                 up_read(&obj->oo_guard);
 888                 RETURN(-ENOENT);
 889         }
 890
 891         for (i = 0; i < npages; i++) {
 892                 CDEBUG(D_INODE, "write %u bytes at %u\n",
 893                         (unsigned) lnb[i].lnb_len,
 894                         (unsigned) lnb[i].lnb_file_offset);
 895
 896                 if (lnb[i].lnb_rc) {
 897                         /* ENOSPC, network RPC error, etc.
 898                          * Unlike ldiskfs, zfs allocates new blocks on rewrite,
 899                          * so we skip this page if lnb_rc is set to -ENOSPC */
 900                         CDEBUG(D_INODE, "obj "DFID": skipping lnb[%u]: rc=%d\n",
 901                                 PFID(lu_object_fid(&dt->do_lu)), i,
 902                                 lnb[i].lnb_rc);
 903                         continue;
 904                 }
 905
 906                 if (new_size < lnb[i].lnb_file_offset + lnb[i].lnb_len)
 907                         new_size = lnb[i].lnb_file_offset + lnb[i].lnb_len;
 908                 if (lnb[i].lnb_page == NULL)
 909                         continue;
 910
 911                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 912                         osd_dmu_write(osd, obj->oo_dn, lnb[i].lnb_file_offset,
 913                                       lnb[i].lnb_len, kmap(lnb[i].lnb_page) +
 914                                       lnb[i].lnb_page_offset, oh->ot_tx);
 915                         kunmap(lnb[i].lnb_page);
 916                         iosize += lnb[i].lnb_len;
 917                         abufsz = lnb[i].lnb_len; /* to drop cache below */
 918                 } else if (lnb[i].lnb_data) {
 919                         int j, apages;
 920                         LASSERT(((unsigned long)lnb[i].lnb_data & 1) == 0);
 921                         /* buffer loaned for zerocopy, try to use it.
 922                          * notice that dmu_assign_arcbuf() is smart
 923                          * enough to recognize changed blocksize
 924                          * in this case it fallbacks to dmu_write() */
 925                         abufsz = arc_buf_size(lnb[i].lnb_data);
 926                         LASSERT(abufsz & PAGE_MASK);
 927                         apages = abufsz >> PAGE_SHIFT;
 928                         LASSERT(i + apages <= npages);
 929                         /* these references to pages must be invalidated
 930                          * to prevent access in osd_bufs_put() */
 931                         for (j = 0; j < apages; j++)
 932                                 lnb[i + j].lnb_page = NULL;
 933                         dmu_assign_arcbuf(&obj->oo_dn->dn_bonus->db,
 934                                           lnb[i].lnb_file_offset,
 935                                           lnb[i].lnb_data, oh->ot_tx);
 936                         /* drop the reference, otherwise osd_put_bufs()
 937                          * will be releasing it - bad! */
 938                         lnb[i].lnb_data = NULL;
 939                         atomic_dec(&osd->od_zerocopy_loan);
 940                         iosize += abufsz;
 941                 } else {
 942                         /* we don't want to deal with cache if nothing
 943                          * has been send to ZFS at this step */
 944                         continue;
 945                 }
 946
 947                 if (!drop_cache)
 948                         continue;
 949
 950                 /* we have to mark dbufs for eviction here because
 951                  * dmu_assign_arcbuf() may create a new dbuf for
 952                  * loaned abuf */
 953                 osd_evict_dbufs_after_write(obj, lnb[i].lnb_file_offset,
 954                                             abufsz);
 955         }
 956
 957         if (unlikely(new_size == 0)) {
 958                 /* no pages to write, no transno is needed */
 959                 th->th_local = 1;
 960                 /* it is important to return 0 even when all lnb_rc == -ENOSPC
 961                  * since ofd_commitrw_write() retries several times on ENOSPC */
 962                 up_read(&obj->oo_guard);
 963                 record_end_io(osd, WRITE, 0, 0, 0);
 964                 RETURN(0);
 965         }
 966
 967         /* if file has grown, take user_size into account */
 968         if (user_size && new_size > user_size)
 969                 new_size = user_size;
 970         write_lock(&obj->oo_attr_lock);
 971         if (obj->oo_attr.la_size < new_size) {
 972                 obj->oo_attr.la_size = new_size;
 973                 write_unlock(&obj->oo_attr_lock);
 974                 /* osd_object_sa_update() will be copying directly from
 975                  * oo_attr into dbuf. any update within a single txg will copy
 976                  * the most actual */
 977                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 978                                           &obj->oo_attr.la_size, 8, oh);
 979         } else {
 980                 write_unlock(&obj->oo_attr_lock);
 981         }
 982
 983         up_read(&obj->oo_guard);
 984
 985         record_end_io(osd, WRITE, 0, iosize, npages);
 986
 987         RETURN(rc);
 988 }
 989
 990 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 991                         struct niobuf_local *lnb, int npages)
 992 {
 993         struct osd_object *obj  = osd_dt_obj(dt);
 994         int                i;
 995         loff_t             eof;
 996
 997         LASSERT(dt_object_exists(dt));
 998         LASSERT(obj->oo_dn);
 999
1000         read_lock(&obj->oo_attr_lock);
1001         eof = obj->oo_attr.la_size;
1002         read_unlock(&obj->oo_attr_lock);
1003
1004         for (i = 0; i < npages; i++) {
1005                 if (unlikely(lnb[i].lnb_rc < 0))
1006                         continue;
1007
1008                 lnb[i].lnb_rc = lnb[i].lnb_len;
1009
1010                 if (lnb[i].lnb_file_offset + lnb[i].lnb_len >= eof) {
1011                         /* send complete pages all the time */
1012                         if (eof <= lnb[i].lnb_file_offset)
1013                                 lnb[i].lnb_rc = 0;
1014
1015                         /* all subsequent rc should be 0 */
1016                         while (++i < npages)
1017                                 lnb[i].lnb_rc = 0;
1018                         break;
1019                 }
1020         }
1021
1022         return 0;
1023 }
1024
1025 /*
1026  * Punch/truncate an object
1027  *
1028  *      IN:     db  - dmu_buf of the object to free data in.
1029  *              off - start of section to free.
1030  *              len - length of section to free (DMU_OBJECT_END => to EOF).
1031  *
1032  *      RETURN: 0 if success
1033  *              error code if failure
1034  *
1035  * The transaction passed to this routine must have
1036  * dmu_tx_hold_sa() and if off < size, dmu_tx_hold_free()
1037  * called and then assigned to a transaction group.
1038  */
1039 static int __osd_object_punch(struct osd_object *obj, objset_t *os,
1040                               dmu_tx_t *tx, uint64_t off, uint64_t len)
1041 {
1042         dnode_t *dn = obj->oo_dn;
1043         uint64_t size = obj->oo_attr.la_size;
1044         int rc = 0;
1045
1046         /* Assert that the transaction has been assigned to a
1047            transaction group. */
1048         LASSERT(tx->tx_txg != 0);
1049         /*
1050          * Nothing to do if file already at desired length.
1051          */
1052         if (len == DMU_OBJECT_END && size == off)
1053                 return 0;
1054
1055         /* if object holds encrypted content, we need to make sure we truncate
1056          * on an encryption unit boundary, or subsequent reads will get
1057          * corrupted content
1058          */
1059         if (len != DMU_OBJECT_END)
1060                 len -= LUSTRE_ENCRYPTION_UNIT_SIZE -
1061                         (off & ~LUSTRE_ENCRYPTION_MASK);
1062         if (obj->oo_lma_flags & LUSTRE_ENCRYPT_FL &&
1063             off & ~LUSTRE_ENCRYPTION_MASK)
1064                 off = (off & LUSTRE_ENCRYPTION_MASK) +
1065                         LUSTRE_ENCRYPTION_UNIT_SIZE;
1066
1067
1068         /* XXX: dnode_free_range() can be used to save on dnode lookup */
1069         if (off < size)
1070                 dmu_free_range(os, dn->dn_object, off, len, tx);
1071
1072         return rc;
1073 }
1074
1075 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
1076                         __u64 start, __u64 end, struct thandle *th)
1077 {
1078         struct osd_object  *obj = osd_dt_obj(dt);
1079         struct osd_device  *osd = osd_obj2dev(obj);
1080         struct osd_thandle *oh;
1081         __u64               len;
1082         int                 rc = 0;
1083         ENTRY;
1084
1085         LASSERT(dt_object_exists(dt));
1086         LASSERT(osd_invariant(obj));
1087
1088         LASSERT(th != NULL);
1089         oh = container_of(th, struct osd_thandle, ot_super);
1090
1091         write_lock(&obj->oo_attr_lock);
1092         /* truncate */
1093         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
1094                 len = DMU_OBJECT_END;
1095         else
1096                 len = end - start;
1097         write_unlock(&obj->oo_attr_lock);
1098
1099         down_read(&obj->oo_guard);
1100         if (obj->oo_destroyed)
1101                 GOTO(out, rc = -ENOENT);
1102
1103         rc = __osd_object_punch(obj, osd->od_os, oh->ot_tx, start, len);
1104
1105         /* set new size */
1106         if (len == DMU_OBJECT_END) {
1107                 write_lock(&obj->oo_attr_lock);
1108                 obj->oo_attr.la_size = start;
1109                 write_unlock(&obj->oo_attr_lock);
1110                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
1111                                           &obj->oo_attr.la_size, 8, oh);
1112         }
1113 out:
1114         up_read(&obj->oo_guard);
1115         RETURN(rc);
1116 }
1117
1118 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
1119                         __u64 start, __u64 end, struct thandle *handle)
1120 {
1121         struct osd_object  *obj = osd_dt_obj(dt);
1122         struct osd_device  *osd = osd_obj2dev(obj);
1123         struct osd_thandle *oh;
1124         __u64               len;
1125         ENTRY;
1126
1127         oh = container_of(handle, struct osd_thandle, ot_super);
1128
1129         read_lock(&obj->oo_attr_lock);
1130         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
1131                 len = DMU_OBJECT_END;
1132         else
1133                 len = end - start;
1134
1135         /* declare we'll free some blocks ... */
1136         /* if object holds encrypted content, we need to make sure we truncate
1137          * on an encryption unit boundary, or subsequent reads will get
1138          * corrupted content
1139          */
1140         if (obj->oo_lma_flags & LUSTRE_ENCRYPT_FL &&
1141             start & ~LUSTRE_ENCRYPTION_MASK)
1142                 start = (start & LUSTRE_ENCRYPTION_MASK) +
1143                         LUSTRE_ENCRYPTION_UNIT_SIZE;
1144         if (start < obj->oo_attr.la_size) {
1145                 read_unlock(&obj->oo_attr_lock);
1146                 dmu_tx_mark_netfree(oh->ot_tx);
1147                 dmu_tx_hold_free(oh->ot_tx, obj->oo_dn->dn_object, start, len);
1148         } else {
1149                 read_unlock(&obj->oo_attr_lock);
1150         }
1151
1152         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
1153                                  obj->oo_attr.la_gid, obj->oo_attr.la_projid,
1154                                  0, oh, NULL, OSD_QID_BLK));
1155 }
1156
1157 static int osd_ladvise(const struct lu_env *env, struct dt_object *dt,
1158                        __u64 start, __u64 end, enum lu_ladvise_type advice)
1159 {
1160         int     rc;
1161         ENTRY;
1162
1163         switch (advice) {
1164         default:
1165                 rc = -ENOTSUPP;
1166                 break;
1167         }
1168
1169         RETURN(rc);
1170 }
1171
1172 static int osd_fallocate(const struct lu_env *env, struct dt_object *dt,
1173                          __u64 start, __u64 end, int mode, struct thandle *th)
1174 {
1175         int rc = -EOPNOTSUPP;
1176         ENTRY;
1177
1178          /*
1179           * space preallocation is not supported for ZFS
1180           * Returns -EOPNOTSUPP for now
1181           */
1182         RETURN(rc);
1183 }
1184
1185 static int osd_declare_fallocate(const struct lu_env *env,
1186                                  struct dt_object *dt, __u64 start, __u64 end,
1187                                  int mode, struct thandle *th)
1188 {
1189         int rc = -EOPNOTSUPP;
1190         ENTRY;
1191
1192          /*
1193           * space preallocation is not supported for ZFS
1194           * Returns -EOPNOTSUPP for now
1195           */
1196         RETURN(rc);
1197 }
1198
1199 static loff_t osd_lseek(const struct lu_env *env, struct dt_object *dt,
1200                         loff_t offset, int whence)
1201 {
1202         struct osd_object *obj = osd_dt_obj(dt);
1203         struct osd_device *osd = osd_obj2dev(obj);
1204         uint64_t size = obj->oo_attr.la_size;
1205         uint64_t result = offset;
1206         int rc;
1207         boolean_t hole = whence == SEEK_HOLE;
1208
1209         ENTRY;
1210
1211         LASSERT(dt_object_exists(dt));
1212         LASSERT(osd_invariant(obj));
1213         LASSERT(offset >= 0);
1214
1215         /* for SEEK_HOLE treat 'offset' beyond the end of file as in real
1216          * hole. LOV to decide after all if that real hole or not.
1217          */
1218         if (offset >= size)
1219                 RETURN(hole ? offset : -ENXIO);
1220
1221         /* Currently ZFS reports no valid DATA offset if object has dirty data
1222          * and we cannot just switch to generic way with reporting DATA on all
1223          * file offsets and HOLE beyond end of file, because we may get HOLE
1224          * reported correctly at some offset inside file then DATA will find
1225          * dirty state and be reported also at that offset by generic approach.
1226          * This is because for HOLE report ZFS doesn't check dirty state but
1227          * does for DATA.
1228          * The only way to get reliable results is to call txg_wait_synced()
1229          * when ZFS reports EBUSY result and repeat lseek call and that is
1230          * controlled via od_sync_on_lseek option.
1231          */
1232         if (!osd->od_sync_on_lseek)
1233                 result = hole ? size : offset;
1234
1235 again:
1236         rc = osd_dmu_offset_next(osd->od_os, obj->oo_dn->dn_object, hole,
1237                                  &result);
1238         /* dirty inode, lseek result is unreliable without sync */
1239         if (rc == EBUSY) {
1240                 txg_wait_synced(dmu_objset_pool(osd->od_os), 0ULL);
1241                 goto again;
1242         }
1243
1244         if (rc == ESRCH)
1245                 RETURN(-ENXIO);
1246
1247         /* ZFS is not exported all needed function, so fall back to the
1248          * generic logic: for HOLE return file size, for DATA return
1249          * the current offset
1250          */
1251         if (rc == EOPNOTSUPP)
1252                 result = hole ? size : offset;
1253         else if (rc)
1254                 return -rc;
1255
1256         /* dmu_offset_next() only works on whole blocks so may return SEEK_HOLE
1257          * result as end of the last block instead of logical EOF which we need
1258          */
1259         if (result > size)
1260                 result = size;
1261
1262         RETURN(result);
1263 }
1264
1265 const struct dt_body_operations osd_body_ops = {
1266         .dbo_read                       = osd_read,
1267         .dbo_declare_write              = osd_declare_write,
1268         .dbo_write                      = osd_write,
1269         .dbo_bufs_get                   = osd_bufs_get,
1270         .dbo_bufs_put                   = osd_bufs_put,
1271         .dbo_write_prep                 = osd_write_prep,
1272         .dbo_declare_write_commit       = osd_declare_write_commit,
1273         .dbo_write_commit               = osd_write_commit,
1274         .dbo_read_prep                  = osd_read_prep,
1275         .dbo_declare_punch              = osd_declare_punch,
1276         .dbo_punch                      = osd_punch,
1277         .dbo_ladvise                    = osd_ladvise,
1278         .dbo_declare_fallocate          = osd_declare_fallocate,
1279         .dbo_fallocate                  = osd_fallocate,
1280         .dbo_lseek                      = osd_lseek,
1281 };
1282
1283 const struct dt_body_operations osd_body_scrub_ops = {
1284         .dbo_read                       = osd_read_no_record,
1285         .dbo_declare_write              = osd_declare_write,
1286         .dbo_write                      = osd_write,
1287 };