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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 /*
  31  * Copyright (c) 2012, 2013, Intel Corporation.
  32  * Use is subject to license terms.
  33  */
  34 /*
  35  * This file is part of Lustre, http://www.lustre.org/
  36  * Lustre is a trademark of Sun Microsystems, Inc.
  37  *
  38  * lustre/osd-zfs/osd_io.c
  39  *
  40  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  41  * Author: Mike Pershin <tappro@whamcloud.com>
  42  */
  43
  44 #define DEBUG_SUBSYSTEM S_OSD
  45
  46 #include <lustre_ver.h>
  47 #include <libcfs/libcfs.h>
  48 #include <obd_support.h>
  49 #include <lustre_net.h>
  50 #include <obd.h>
  51 #include <obd_class.h>
  52 #include <lustre_disk.h>
  53 #include <lustre_fid.h>
  54 #include <lustre/lustre_idl.h>  /* LLOG_CHUNK_SIZE definition */
  55
  56 #include "osd_internal.h"
  57
  58 #include <sys/dnode.h>
  59 #include <sys/dbuf.h>
  60 #include <sys/spa.h>
  61 #include <sys/stat.h>
  62 #include <sys/zap.h>
  63 #include <sys/spa_impl.h>
  64 #include <sys/zfs_znode.h>
  65 #include <sys/dmu_tx.h>
  66 #include <sys/dmu_objset.h>
  67 #include <sys/dsl_prop.h>
  68 #include <sys/sa_impl.h>
  69 #include <sys/txg.h>
  70
  71 static char *osd_zerocopy_tag = "zerocopy";
  72
  73 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
  74                         struct lu_buf *buf, loff_t *pos,
  75                         struct lustre_capa *capa)
  76 {
  77         struct osd_object *obj  = osd_dt_obj(dt);
  78         struct osd_device *osd = osd_obj2dev(obj);
  79         uint64_t           old_size;
  80         int                size = buf->lb_len;
  81         int                rc;
  82
  83         LASSERT(dt_object_exists(dt));
  84         LASSERT(obj->oo_db);
  85
  86         read_lock(&obj->oo_attr_lock);
  87         old_size = obj->oo_attr.la_size;
  88         read_unlock(&obj->oo_attr_lock);
  89
  90         if (*pos + size > old_size) {
  91                 if (old_size < *pos)
  92                         return 0;
  93                 else
  94                         size = old_size - *pos;
  95         }
  96
  97         rc = -dmu_read(osd->od_objset.os, obj->oo_db->db_object, *pos, size,
  98                         buf->lb_buf, DMU_READ_PREFETCH);
  99         if (rc == 0) {
 100                 rc = size;
 101                 *pos += size;
 102
 103                 /* XXX: workaround for bug in HEAD: fsfilt_ldiskfs_read() returns
 104                  * requested number of bytes, not actually read ones */
 105                 if (S_ISLNK(obj->oo_dt.do_lu.lo_header->loh_attr))
 106                         rc = buf->lb_len;
 107         }
 108         return rc;
 109 }
 110
 111 static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
 112                                 const struct lu_buf *buf, loff_t pos,
 113                                 struct thandle *th)
 114 {
 115         struct osd_object  *obj  = osd_dt_obj(dt);
 116         struct osd_device  *osd = osd_obj2dev(obj);
 117         struct osd_thandle *oh;
 118         uint64_t            oid;
 119         ENTRY;
 120
 121         oh = container_of0(th, struct osd_thandle, ot_super);
 122
 123         /* in some cases declare can race with creation (e.g. llog)
 124          * and we need to wait till object is initialized. notice
 125          * LOHA_EXISTs is supposed to be the last step in the
 126          * initialization */
 127
 128         /* declare possible size change. notice we can't check
 129          * current size here as another thread can change it */
 130
 131         if (dt_object_exists(dt)) {
 132                 LASSERT(obj->oo_db);
 133                 oid = obj->oo_db->db_object;
 134
 135                 dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 136         } else {
 137                 oid = DMU_NEW_OBJECT;
 138                 dmu_tx_hold_sa_create(oh->ot_tx, ZFS_SA_BASE_ATTR_SIZE);
 139         }
 140
 141         /* XXX: we still miss for append declaration support in ZFS
 142          *      -1 means append which is used by llog mostly, llog
 143          *      can grow upto LLOG_CHUNK_SIZE*8 records */
 144         if (pos == -1)
 145                 pos = max_t(loff_t, 256 * 8 * LLOG_CHUNK_SIZE,
 146                             obj->oo_attr.la_size + (2 << 20));
 147         dmu_tx_hold_write(oh->ot_tx, oid, pos, buf->lb_len);
 148
 149         /* dt_declare_write() is usually called for system objects, such
 150          * as llog or last_rcvd files. We needn't enforce quota on those
 151          * objects, so always set the lqi_space as 0. */
 152         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 153                                  obj->oo_attr.la_gid, 0, oh, true, NULL,
 154                                  false));
 155 }
 156
 157 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
 158                         const struct lu_buf *buf, loff_t *pos,
 159                         struct thandle *th, struct lustre_capa *capa,
 160                         int ignore_quota)
 161 {
 162         struct osd_object  *obj  = osd_dt_obj(dt);
 163         struct osd_device  *osd = osd_obj2dev(obj);
 164         udmu_objset_t      *uos = &osd->od_objset;
 165         struct osd_thandle *oh;
 166         uint64_t            offset = *pos;
 167         int                 rc;
 168         ENTRY;
 169
 170         LASSERT(dt_object_exists(dt));
 171         LASSERT(obj->oo_db);
 172
 173         LASSERT(th != NULL);
 174         oh = container_of0(th, struct osd_thandle, ot_super);
 175
 176         dmu_write(osd->od_objset.os, obj->oo_db->db_object, offset,
 177                 (uint64_t)buf->lb_len, buf->lb_buf, oh->ot_tx);
 178         write_lock(&obj->oo_attr_lock);
 179         if (obj->oo_attr.la_size < offset + buf->lb_len) {
 180                 obj->oo_attr.la_size = offset + buf->lb_len;
 181                 write_unlock(&obj->oo_attr_lock);
 182                 /* osd_object_sa_update() will be copying directly from oo_attr
 183                  * into dbuf.  any update within a single txg will copy the
 184                  * most actual */
 185                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(uos),
 186                                         &obj->oo_attr.la_size, 8, oh);
 187                 if (unlikely(rc))
 188                         GOTO(out, rc);
 189         } else {
 190                 write_unlock(&obj->oo_attr_lock);
 191         }
 192
 193         *pos += buf->lb_len;
 194         rc = buf->lb_len;
 195
 196 out:
 197         RETURN(rc);
 198 }
 199
 200 /*
 201  * XXX: for the moment I don't want to use lnb_flags for osd-internal
 202  *      purposes as it's not very well defined ...
 203  *      instead I use the lowest bit of the address so that:
 204  *        arc buffer:  .lnb_obj = abuf          (arc we loan for write)
 205  *        dbuf buffer: .lnb_obj = dbuf | 1      (dbuf we get for read)
 206  *        copy buffer: .lnb_page->mapping = obj (page we allocate for write)
 207  *
 208  *      bzzz, to blame
 209  */
 210 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
 211                         struct niobuf_local *lnb, int npages)
 212 {
 213         struct osd_object *obj  = osd_dt_obj(dt);
 214         struct osd_device *osd = osd_obj2dev(obj);
 215         unsigned long      ptr;
 216         int                i;
 217
 218         LASSERT(dt_object_exists(dt));
 219         LASSERT(obj->oo_db);
 220
 221         for (i = 0; i < npages; i++) {
 222                 if (lnb[i].page == NULL)
 223                         continue;
 224                 if (lnb[i].page->mapping == (void *)obj) {
 225                         /* this is anonymous page allocated for copy-write */
 226                         lnb[i].page->mapping = NULL;
 227                         __free_page(lnb[i].page);
 228                         atomic_dec(&osd->od_zerocopy_alloc);
 229                 } else {
 230                         /* see comment in osd_bufs_get_read() */
 231                         ptr = (unsigned long)lnb[i].dentry;
 232                         if (ptr & 1UL) {
 233                                 ptr &= ~1UL;
 234                                 dmu_buf_rele((void *)ptr, osd_zerocopy_tag);
 235                                 atomic_dec(&osd->od_zerocopy_pin);
 236                         } else if (lnb[i].dentry != NULL) {
 237                                 dmu_return_arcbuf((void *)lnb[i].dentry);
 238                                 atomic_dec(&osd->od_zerocopy_loan);
 239                         }
 240                 }
 241                 lnb[i].page = NULL;
 242                 lnb[i].dentry = NULL;
 243         }
 244
 245         return 0;
 246 }
 247
 248 static inline struct page *kmem_to_page(void *addr)
 249 {
 250         if (is_vmalloc_addr(addr))
 251                 return vmalloc_to_page(addr);
 252         else
 253                 return virt_to_page(addr);
 254 }
 255
 256 static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
 257                                 loff_t off, ssize_t len, struct niobuf_local *lnb)
 258 {
 259         struct osd_device *osd = osd_obj2dev(obj);
 260         dmu_buf_t        **dbp;
 261         int                rc, i, numbufs, npages = 0;
 262         ENTRY;
 263
 264         /* grab buffers for read:
 265          * OSD API let us to grab buffers first, then initiate IO(s)
 266          * so that all required IOs will be done in parallel, but at the
 267          * moment DMU doesn't provide us with a method to grab buffers.
 268          * If we discover this is a vital for good performance we
 269          * can get own replacement for dmu_buf_hold_array_by_bonus().
 270          */
 271         while (len > 0) {
 272                 rc = -dmu_buf_hold_array_by_bonus(obj->oo_db, off, len, TRUE,
 273                                                   osd_zerocopy_tag, &numbufs,
 274                                                   &dbp);
 275                 if (unlikely(rc))
 276                         GOTO(err, rc);
 277
 278                 for (i = 0; i < numbufs; i++) {
 279                         int bufoff, tocpy, thispage;
 280                         void *dbf = dbp[i];
 281
 282                         LASSERT(len > 0);
 283
 284                         atomic_inc(&osd->od_zerocopy_pin);
 285
 286                         bufoff = off - dbp[i]->db_offset;
 287                         tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
 288
 289                         /* kind of trick to differentiate dbuf vs. arcbuf */
 290                         LASSERT(((unsigned long)dbp[i] & 1) == 0);
 291                         dbf = (void *) ((unsigned long)dbp[i] | 1);
 292
 293                         while (tocpy > 0) {
 294                                 thispage = PAGE_CACHE_SIZE;
 295                                 thispage -= bufoff & (PAGE_CACHE_SIZE - 1);
 296                                 thispage = min(tocpy, thispage);
 297
 298                                 lnb->rc = 0;
 299                                 lnb->lnb_file_offset = off;
 300                                 lnb->lnb_page_offset = bufoff & ~CFS_PAGE_MASK;
 301                                 lnb->len = thispage;
 302                                 lnb->page = kmem_to_page(dbp[i]->db_data +
 303                                                                 bufoff);
 304                                 /* mark just a single slot: we need this
 305                                  * reference to dbuf to be release once */
 306                                 lnb->dentry = dbf;
 307                                 dbf = NULL;
 308
 309                                 tocpy -= thispage;
 310                                 len -= thispage;
 311                                 bufoff += thispage;
 312                                 off += thispage;
 313
 314                                 npages++;
 315                                 lnb++;
 316                         }
 317
 318                         /* steal dbuf so dmu_buf_rele_array() cant release it */
 319                         dbp[i] = NULL;
 320                 }
 321
 322                 dmu_buf_rele_array(dbp, numbufs, osd_zerocopy_tag);
 323         }
 324
 325         RETURN(npages);
 326
 327 err:
 328         LASSERT(rc < 0);
 329         osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
 330         RETURN(rc);
 331 }
 332
 333 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
 334                                 loff_t off, ssize_t len, struct niobuf_local *lnb)
 335 {
 336         struct osd_device *osd = osd_obj2dev(obj);
 337         int                plen, off_in_block, sz_in_block;
 338         int                rc, i = 0, npages = 0;
 339         arc_buf_t         *abuf;
 340         uint32_t           bs;
 341         uint64_t           dummy;
 342         ENTRY;
 343
 344         dmu_object_size_from_db(obj->oo_db, &bs, &dummy);
 345
 346         /*
 347          * currently only full blocks are subject to zerocopy approach:
 348          * so that we're sure nobody is trying to update the same block
 349          */
 350         while (len > 0) {
 351                 LASSERT(npages < PTLRPC_MAX_BRW_PAGES);
 352
 353                 off_in_block = off & (bs - 1);
 354                 sz_in_block = min_t(int, bs - off_in_block, len);
 355
 356                 if (sz_in_block == bs) {
 357                         /* full block, try to use zerocopy */
 358
 359                         abuf = dmu_request_arcbuf(obj->oo_db, bs);
 360                         if (unlikely(abuf == NULL))
 361                                 GOTO(out_err, rc = -ENOMEM);
 362
 363                         atomic_inc(&osd->od_zerocopy_loan);
 364
 365                         /* go over pages arcbuf contains, put them as
 366                          * local niobufs for ptlrpc's bulks */
 367                         while (sz_in_block > 0) {
 368                                 plen = min_t(int, sz_in_block, PAGE_CACHE_SIZE);
 369
 370                                 lnb[i].lnb_file_offset = off;
 371                                 lnb[i].lnb_page_offset = 0;
 372                                 lnb[i].len = plen;
 373                                 lnb[i].rc = 0;
 374                                 if (sz_in_block == bs)
 375                                         lnb[i].dentry = (void *)abuf;
 376                                 else
 377                                         lnb[i].dentry = NULL;
 378
 379                                 /* this one is not supposed to fail */
 380                                 lnb[i].page = kmem_to_page(abuf->b_data +
 381                                                         off_in_block);
 382                                 LASSERT(lnb[i].page);
 383
 384                                 lprocfs_counter_add(osd->od_stats,
 385                                                 LPROC_OSD_ZEROCOPY_IO, 1);
 386
 387                                 sz_in_block -= plen;
 388                                 len -= plen;
 389                                 off += plen;
 390                                 off_in_block += plen;
 391                                 i++;
 392                                 npages++;
 393                         }
 394                 } else {
 395                         if (off_in_block == 0 && len < bs &&
 396                                         off + len >= obj->oo_attr.la_size)
 397                                 lprocfs_counter_add(osd->od_stats,
 398                                                 LPROC_OSD_TAIL_IO, 1);
 399
 400                         /* can't use zerocopy, allocate temp. buffers */
 401                         while (sz_in_block > 0) {
 402                                 plen = min_t(int, sz_in_block, PAGE_CACHE_SIZE);
 403
 404                                 lnb[i].lnb_file_offset = off;
 405                                 lnb[i].lnb_page_offset = 0;
 406                                 lnb[i].len = plen;
 407                                 lnb[i].rc = 0;
 408                                 lnb[i].dentry = NULL;
 409
 410                                 lnb[i].page = alloc_page(OSD_GFP_IO);
 411                                 if (unlikely(lnb[i].page == NULL))
 412                                         GOTO(out_err, rc = -ENOMEM);
 413
 414                                 LASSERT(lnb[i].page->mapping == NULL);
 415                                 lnb[i].page->mapping = (void *)obj;
 416
 417                                 atomic_inc(&osd->od_zerocopy_alloc);
 418                                 lprocfs_counter_add(osd->od_stats,
 419                                                 LPROC_OSD_COPY_IO, 1);
 420
 421                                 sz_in_block -= plen;
 422                                 len -= plen;
 423                                 off += plen;
 424                                 i++;
 425                                 npages++;
 426                         }
 427                 }
 428         }
 429
 430         RETURN(npages);
 431
 432 out_err:
 433         osd_bufs_put(env, &obj->oo_dt, lnb, npages);
 434         RETURN(rc);
 435 }
 436
 437 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
 438                         loff_t offset, ssize_t len, struct niobuf_local *lnb,
 439                         int rw, struct lustre_capa *capa)
 440 {
 441         struct osd_object *obj  = osd_dt_obj(dt);
 442         int                rc;
 443
 444         LASSERT(dt_object_exists(dt));
 445         LASSERT(obj->oo_db);
 446
 447         if (rw == 0)
 448                 rc = osd_bufs_get_read(env, obj, offset, len, lnb);
 449         else
 450                 rc = osd_bufs_get_write(env, obj, offset, len, lnb);
 451
 452         return rc;
 453 }
 454
 455 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
 456                         struct niobuf_local *lnb, int npages)
 457 {
 458         struct osd_object *obj = osd_dt_obj(dt);
 459
 460         LASSERT(dt_object_exists(dt));
 461         LASSERT(obj->oo_db);
 462
 463         return 0;
 464 }
 465
 466 /* Return number of blocks that aren't mapped in the [start, start + size]
 467  * region */
 468 static int osd_count_not_mapped(struct osd_object *obj, uint64_t start,
 469                                 uint32_t size)
 470 {
 471         dmu_buf_impl_t  *dbi = (dmu_buf_impl_t *)obj->oo_db;
 472         dmu_buf_impl_t  *db;
 473         dnode_t         *dn;
 474         uint32_t         blkshift;
 475         uint64_t         end, blkid;
 476         int              rc;
 477         ENTRY;
 478
 479         DB_DNODE_ENTER(dbi);
 480         dn = DB_DNODE(dbi);
 481
 482         if (dn->dn_maxblkid == 0) {
 483                 if (start + size <= dn->dn_datablksz)
 484                         GOTO(out, size = 0);
 485                 if (start < dn->dn_datablksz)
 486                         start = dn->dn_datablksz;
 487                 /* assume largest block size */
 488                 blkshift = SPA_MAXBLOCKSHIFT;
 489         } else {
 490                 /* blocksize can't change */
 491                 blkshift = dn->dn_datablkshift;
 492         }
 493
 494         /* compute address of last block */
 495         end = (start + size - 1) >> blkshift;
 496         /* align start on block boundaries */
 497         start >>= blkshift;
 498
 499         /* size is null, can't be mapped */
 500         if (obj->oo_attr.la_size == 0 || dn->dn_maxblkid == 0)
 501                 GOTO(out, size = (end - start + 1) << blkshift);
 502
 503         /* beyond EOF, can't be mapped */
 504         if (start > dn->dn_maxblkid)
 505                 GOTO(out, size = (end - start + 1) << blkshift);
 506
 507         size = 0;
 508         for (blkid = start; blkid <= end; blkid++) {
 509                 if (blkid == dn->dn_maxblkid)
 510                         /* this one is mapped for sure */
 511                         continue;
 512                 if (blkid > dn->dn_maxblkid) {
 513                         size += (end - blkid + 1) << blkshift;
 514                         GOTO(out, size);
 515                 }
 516
 517                 rc = dbuf_hold_impl(dn, 0, blkid, TRUE, FTAG, &db);
 518                 if (rc) {
 519                         /* for ENOENT (block not mapped) and any other errors,
 520                          * assume the block isn't mapped */
 521                         size += 1 << blkshift;
 522                         continue;
 523                 }
 524                 dbuf_rele(db, FTAG);
 525         }
 526
 527         GOTO(out, size);
 528 out:
 529         DB_DNODE_EXIT(dbi);
 530         return size;
 531 }
 532
 533 static int osd_declare_write_commit(const struct lu_env *env,
 534                                 struct dt_object *dt,
 535                                 struct niobuf_local *lnb, int npages,
 536                                 struct thandle *th)
 537 {
 538         struct osd_object  *obj = osd_dt_obj(dt);
 539         struct osd_device  *osd = osd_obj2dev(obj);
 540         struct osd_thandle *oh;
 541         uint64_t            offset = 0;
 542         uint32_t            size = 0;
 543         int                 i, rc, flags = 0;
 544         bool                ignore_quota = false, synced = false;
 545         long long           space = 0;
 546         ENTRY;
 547
 548         LASSERT(dt_object_exists(dt));
 549         LASSERT(obj->oo_db);
 550
 551         LASSERT(lnb);
 552         LASSERT(npages > 0);
 553
 554         oh = container_of0(th, struct osd_thandle, ot_super);
 555
 556         for (i = 0; i < npages; i++) {
 557                 if (lnb[i].rc)
 558                         /* ENOSPC, network RPC error, etc.
 559                          * We don't want to book space for pages which will be
 560                          * skipped in osd_write_commit(). Hence we skip pages
 561                          * with lnb_rc != 0 here too */
 562                         continue;
 563                 /* ignore quota for the whole request if any page is from
 564                  * client cache or written by root.
 565                  *
 566                  * XXX once we drop the 1.8 client support, the checking
 567                  * for whether page is from cache can be simplified as:
 568                  * !(lnb[i].flags & OBD_BRW_SYNC)
 569                  *
 570                  * XXX we could handle this on per-lnb basis as done by
 571                  * grant. */
 572                 if ((lnb[i].flags & OBD_BRW_NOQUOTA) ||
 573                     (lnb[i].flags & (OBD_BRW_FROM_GRANT | OBD_BRW_SYNC)) ==
 574                     OBD_BRW_FROM_GRANT)
 575                         ignore_quota = true;
 576                 if (size == 0) {
 577                         /* first valid lnb */
 578                         offset = lnb[i].lnb_file_offset;
 579                         size = lnb[i].len;
 580                         continue;
 581                 }
 582                 if (offset + size == lnb[i].lnb_file_offset) {
 583                         /* this lnb is contiguous to the previous one */
 584                         size += lnb[i].len;
 585                         continue;
 586                 }
 587
 588                 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object,
 589                                   offset, size);
 590                 /* estimating space that will be consumed by a write is rather
 591                  * complicated with ZFS. As a consequence, we don't account for
 592                  * indirect blocks and quota overrun will be adjusted once the
 593                  * operation is committed, if required. */
 594                 space += osd_count_not_mapped(obj, offset, size);
 595
 596                 offset = lnb[i].lnb_file_offset;
 597                 size = lnb[i].len;
 598         }
 599
 600         if (size) {
 601                 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object,
 602                                   offset, size);
 603                 space += osd_count_not_mapped(obj, offset, size);
 604         }
 605
 606         dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 607
 608         oh->ot_write_commit = 1; /* used in osd_trans_start() for fail_loc */
 609
 610         /* backend zfs filesystem might be configured to store multiple data
 611          * copies */
 612         space  *= osd->od_objset.os->os_copies;
 613         space   = toqb(space);
 614         CDEBUG(D_QUOTA, "writting %d pages, reserving "LPD64"K of quota "
 615                "space\n", npages, space);
 616
 617 retry:
 618         /* acquire quota space if needed */
 619         rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 620                                obj->oo_attr.la_gid, space, oh, true, &flags,
 621                                ignore_quota);
 622
 623         if (!synced && rc == -EDQUOT && (flags & QUOTA_FL_SYNC) != 0) {
 624                 dt_sync(env, th->th_dev);
 625                 synced = true;
 626                 CDEBUG(D_QUOTA, "retry after sync\n");
 627                 flags = 0;
 628                 goto retry;
 629         }
 630
 631         /* we need only to store the overquota flags in the first lnb for
 632          * now, once we support multiple objects BRW, this code needs be
 633          * revised. */
 634         if (flags & QUOTA_FL_OVER_USRQUOTA)
 635                 lnb[0].flags |= OBD_BRW_OVER_USRQUOTA;
 636         if (flags & QUOTA_FL_OVER_GRPQUOTA)
 637                 lnb[0].flags |= OBD_BRW_OVER_GRPQUOTA;
 638
 639         RETURN(rc);
 640 }
 641
 642 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 643                         struct niobuf_local *lnb, int npages,
 644                         struct thandle *th)
 645 {
 646         struct osd_object  *obj  = osd_dt_obj(dt);
 647         struct osd_device  *osd = osd_obj2dev(obj);
 648         udmu_objset_t      *uos = &osd->od_objset;
 649         struct osd_thandle *oh;
 650         uint64_t            new_size = 0;
 651         int                 i, rc = 0;
 652         ENTRY;
 653
 654         LASSERT(dt_object_exists(dt));
 655         LASSERT(obj->oo_db);
 656
 657         LASSERT(th != NULL);
 658         oh = container_of0(th, struct osd_thandle, ot_super);
 659
 660         for (i = 0; i < npages; i++) {
 661                 CDEBUG(D_INODE, "write %u bytes at %u\n",
 662                         (unsigned) lnb[i].len,
 663                         (unsigned) lnb[i].lnb_file_offset);
 664
 665                 if (lnb[i].rc) {
 666                         /* ENOSPC, network RPC error, etc.
 667                          * Unlike ldiskfs, zfs allocates new blocks on rewrite,
 668                          * so we skip this page if lnb_rc is set to -ENOSPC */
 669                         CDEBUG(D_INODE, "obj "DFID": skipping lnb[%u]: rc=%d\n",
 670                                 PFID(lu_object_fid(&dt->do_lu)), i,
 671                                 lnb[i].rc);
 672                         continue;
 673                 }
 674
 675                 if (lnb[i].page->mapping == (void *)obj) {
 676                         dmu_write(osd->od_objset.os, obj->oo_db->db_object,
 677                                 lnb[i].lnb_file_offset, lnb[i].len,
 678                                 kmap(lnb[i].page), oh->ot_tx);
 679                         kunmap(lnb[i].page);
 680                 } else if (lnb[i].dentry) {
 681                         LASSERT(((unsigned long)lnb[i].dentry & 1) == 0);
 682                         /* buffer loaned for zerocopy, try to use it.
 683                          * notice that dmu_assign_arcbuf() is smart
 684                          * enough to recognize changed blocksize
 685                          * in this case it fallbacks to dmu_write() */
 686                         dmu_assign_arcbuf(obj->oo_db, lnb[i].lnb_file_offset,
 687                                         (void *)lnb[i].dentry, oh->ot_tx);
 688                         /* drop the reference, otherwise osd_put_bufs()
 689                          * will be releasing it - bad! */
 690                         lnb[i].dentry = NULL;
 691                         atomic_dec(&osd->od_zerocopy_loan);
 692                 }
 693
 694                 if (new_size < lnb[i].lnb_file_offset + lnb[i].len)
 695                         new_size = lnb[i].lnb_file_offset + lnb[i].len;
 696         }
 697
 698         if (unlikely(new_size == 0)) {
 699                 /* no pages to write, no transno is needed */
 700                 th->th_local = 1;
 701                 /* it is important to return 0 even when all lnb_rc == -ENOSPC
 702                  * since ofd_commitrw_write() retries several times on ENOSPC */
 703                 RETURN(0);
 704         }
 705
 706         write_lock(&obj->oo_attr_lock);
 707         if (obj->oo_attr.la_size < new_size) {
 708                 obj->oo_attr.la_size = new_size;
 709                 write_unlock(&obj->oo_attr_lock);
 710                 /* osd_object_sa_update() will be copying directly from
 711                  * oo_attr into dbuf. any update within a single txg will copy
 712                  * the most actual */
 713                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(uos),
 714                                         &obj->oo_attr.la_size, 8, oh);
 715         } else {
 716                 write_unlock(&obj->oo_attr_lock);
 717         }
 718
 719         RETURN(rc);
 720 }
 721
 722 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 723                         struct niobuf_local *lnb, int npages)
 724 {
 725         struct osd_object *obj  = osd_dt_obj(dt);
 726         struct lu_buf      buf;
 727         loff_t             offset;
 728         int                i;
 729
 730         LASSERT(dt_object_exists(dt));
 731         LASSERT(obj->oo_db);
 732
 733         for (i = 0; i < npages; i++) {
 734                 buf.lb_buf = kmap(lnb[i].page);
 735                 buf.lb_len = lnb[i].len;
 736                 offset = lnb[i].lnb_file_offset;
 737
 738                 CDEBUG(D_OTHER, "read %u bytes at %u\n",
 739                         (unsigned) lnb[i].len,
 740                         (unsigned) lnb[i].lnb_file_offset);
 741                 lnb[i].rc = osd_read(env, dt, &buf, &offset, NULL);
 742                 kunmap(lnb[i].page);
 743
 744                 if (lnb[i].rc < buf.lb_len) {
 745                         /* all subsequent rc should be 0 */
 746                         while (++i < npages)
 747                                 lnb[i].rc = 0;
 748                         break;
 749                 }
 750         }
 751
 752         return 0;
 753 }
 754
 755 /*
 756  * Punch/truncate an object
 757  *
 758  *      IN:     db  - dmu_buf of the object to free data in.
 759  *              off - start of section to free.
 760  *              len - length of section to free (DMU_OBJECT_END => to EOF).
 761  *
 762  *      RETURN: 0 if success
 763  *              error code if failure
 764  *
 765  * The transaction passed to this routine must have
 766  * dmu_tx_hold_sa() and if off < size, dmu_tx_hold_free()
 767  * called and then assigned to a transaction group.
 768  */
 769 static int __osd_object_punch(objset_t *os, dmu_buf_t *db, dmu_tx_t *tx,
 770                                 uint64_t size, uint64_t off, uint64_t len)
 771 {
 772         int rc = 0;
 773
 774         /* Assert that the transaction has been assigned to a
 775            transaction group. */
 776         LASSERT(tx->tx_txg != 0);
 777         /*
 778          * Nothing to do if file already at desired length.
 779          */
 780         if (len == DMU_OBJECT_END && size == off)
 781                 return 0;
 782
 783         if (off < size)
 784                 rc = -dmu_free_range(os, db->db_object, off, len, tx);
 785
 786         return rc;
 787 }
 788
 789 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
 790                         __u64 start, __u64 end, struct thandle *th,
 791                         struct lustre_capa *capa)
 792 {
 793         struct osd_object  *obj = osd_dt_obj(dt);
 794         struct osd_device  *osd = osd_obj2dev(obj);
 795         udmu_objset_t      *uos = &osd->od_objset;
 796         struct osd_thandle *oh;
 797         __u64               len;
 798         int                 rc = 0;
 799         ENTRY;
 800
 801         LASSERT(dt_object_exists(dt));
 802         LASSERT(osd_invariant(obj));
 803
 804         LASSERT(th != NULL);
 805         oh = container_of0(th, struct osd_thandle, ot_super);
 806
 807         write_lock(&obj->oo_attr_lock);
 808         /* truncate */
 809         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
 810                 len = DMU_OBJECT_END;
 811         else
 812                 len = end - start;
 813         write_unlock(&obj->oo_attr_lock);
 814
 815         rc = __osd_object_punch(osd->od_objset.os, obj->oo_db, oh->ot_tx,
 816                                 obj->oo_attr.la_size, start, len);
 817         /* set new size */
 818         if (len == DMU_OBJECT_END) {
 819                 write_lock(&obj->oo_attr_lock);
 820                 obj->oo_attr.la_size = start;
 821                 write_unlock(&obj->oo_attr_lock);
 822                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(uos),
 823                                         &obj->oo_attr.la_size, 8, oh);
 824         }
 825         RETURN(rc);
 826 }
 827
 828 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
 829                         __u64 start, __u64 end, struct thandle *handle)
 830 {
 831         struct osd_object  *obj = osd_dt_obj(dt);
 832         struct osd_device  *osd = osd_obj2dev(obj);
 833         struct osd_thandle *oh;
 834         __u64               len;
 835         ENTRY;
 836
 837         oh = container_of0(handle, struct osd_thandle, ot_super);
 838
 839         read_lock(&obj->oo_attr_lock);
 840         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
 841                 len = DMU_OBJECT_END;
 842         else
 843                 len = end - start;
 844
 845         /* declare we'll free some blocks ... */
 846         if (start < obj->oo_attr.la_size) {
 847                 read_unlock(&obj->oo_attr_lock);
 848                 dmu_tx_hold_free(oh->ot_tx, obj->oo_db->db_object, start, len);
 849         } else {
 850                 read_unlock(&obj->oo_attr_lock);
 851         }
 852
 853         /* ... and we'll modify size attribute */
 854         dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 855
 856         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 857                                  obj->oo_attr.la_gid, 0, oh, true, NULL,
 858                                  false));
 859 }
 860
 861
 862 struct dt_body_operations osd_body_ops = {
 863         .dbo_read                       = osd_read,
 864         .dbo_declare_write              = osd_declare_write,
 865         .dbo_write                      = osd_write,
 866         .dbo_bufs_get                   = osd_bufs_get,
 867         .dbo_bufs_put                   = osd_bufs_put,
 868         .dbo_write_prep                 = osd_write_prep,
 869         .dbo_declare_write_commit       = osd_declare_write_commit,
 870         .dbo_write_commit               = osd_write_commit,
 871         .dbo_read_prep                  = osd_read_prep,
 872         .dbo_declare_punch              = osd_declare_punch,
 873         .dbo_punch                      = osd_punch,
 874 };
 875