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  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/osd-zfs/osd_io.c
  33  *
  34  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  35  * Author: Mike Pershin <tappro@whamcloud.com>
  36  */
  37
  38 #define DEBUG_SUBSYSTEM S_OSD
  39
  40 #include <libcfs/libcfs.h>
  41 #include <obd_support.h>
  42 #include <lustre_net.h>
  43 #include <obd.h>
  44 #include <obd_class.h>
  45 #include <lustre_disk.h>
  46 #include <lustre_fid.h>
  47 #include <lustre_quota.h>
  48
  49 #include "osd_internal.h"
  50
  51 #include <sys/dnode.h>
  52 #include <sys/dbuf.h>
  53 #include <sys/spa.h>
  54 #include <sys/stat.h>
  55 #include <sys/zap.h>
  56 #include <sys/spa_impl.h>
  57 #include <sys/zfs_znode.h>
  58 #include <sys/dmu_tx.h>
  59 #include <sys/dmu_objset.h>
  60 #include <sys/dsl_prop.h>
  61 #include <sys/sa_impl.h>
  62 #include <sys/txg.h>
  63
  64 static char *osd_0copy_tag = "zerocopy";
  65
  66
  67 static void dbuf_set_pending_evict(dmu_buf_t *db)
  68 {
  69         dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
  70         dbi->db_pending_evict = TRUE;
  71 }
  72
  73 static void record_start_io(struct osd_device *osd, int rw, int discont_pages)
  74 {
  75         struct obd_histogram *h = osd->od_brw_stats.hist;
  76
  77         if (rw == READ) {
  78                 atomic_inc(&osd->od_r_in_flight);
  79                 lprocfs_oh_tally(&h[BRW_R_RPC_HIST],
  80                                  atomic_read(&osd->od_r_in_flight));
  81                 lprocfs_oh_tally(&h[BRW_R_DISCONT_PAGES], discont_pages);
  82
  83         } else {
  84                 atomic_inc(&osd->od_w_in_flight);
  85                 lprocfs_oh_tally(&h[BRW_W_RPC_HIST],
  86                                  atomic_read(&osd->od_w_in_flight));
  87                 lprocfs_oh_tally(&h[BRW_W_DISCONT_PAGES], discont_pages);
  88
  89         }
  90 }
  91
  92 static void record_end_io(struct osd_device *osd, int rw,
  93                           unsigned long elapsed, int disksize, int npages)
  94 {
  95         struct obd_histogram *h = osd->od_brw_stats.hist;
  96
  97         if (rw == READ)
  98                 atomic_dec(&osd->od_r_in_flight);
  99         else
 100                 atomic_dec(&osd->od_w_in_flight);
 101
 102         lprocfs_oh_tally_log2(&h[BRW_R_PAGES + rw], npages);
 103         if (disksize > 0)
 104                 lprocfs_oh_tally_log2(&h[BRW_R_DISK_IOSIZE + rw], disksize);
 105         if (elapsed)
 106                 lprocfs_oh_tally_log2(&h[BRW_R_IO_TIME + rw], 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         ktime_t start;
 146         s64 delta_ms;
 147         int rc;
 148
 149         start = ktime_get();
 150         record_start_io(osd, READ, 0);
 151         rc = __osd_read(env, dt, buf, pos, &size);
 152         delta_ms = ktime_ms_delta(ktime_get(), start);
 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_of0(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_of0(th, struct osd_thandle, ot_super);
 223
 224         osd_dmu_write(osd, obj->oo_dn, offset, (uint64_t)buf->lb_len,
 225                       buf->lb_buf, oh->ot_tx);
 226         write_lock(&obj->oo_attr_lock);
 227         if (obj->oo_attr.la_size < offset + buf->lb_len) {
 228                 obj->oo_attr.la_size = offset + buf->lb_len;
 229                 write_unlock(&obj->oo_attr_lock);
 230                 /* osd_object_sa_update() will be copying directly from oo_attr
 231                  * into dbuf.  any update within a single txg will copy the
 232                  * most actual */
 233                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 234                                         &obj->oo_attr.la_size, 8, oh);
 235                 if (unlikely(rc))
 236                         GOTO(out, rc);
 237         } else {
 238                 write_unlock(&obj->oo_attr_lock);
 239         }
 240
 241         *pos += buf->lb_len;
 242         rc = buf->lb_len;
 243
 244 out:
 245         RETURN(rc);
 246 }
 247
 248 /*
 249  * XXX: for the moment I don't want to use lnb_flags for osd-internal
 250  *      purposes as it's not very well defined ...
 251  *      instead I use the lowest bit of the address so that:
 252  *        arc buffer:  .lnb_data = abuf          (arc we loan for write)
 253  *        dbuf buffer: .lnb_data = dbuf | 1      (dbuf we get for read)
 254  *        copy buffer: .lnb_page->mapping = obj (page we allocate for write)
 255  *
 256  *      bzzz, to blame
 257  */
 258 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
 259                         struct niobuf_local *lnb, int npages)
 260 {
 261         struct osd_object *obj  = osd_dt_obj(dt);
 262         struct osd_device *osd = osd_obj2dev(obj);
 263         unsigned long      ptr;
 264         int                i;
 265
 266         LASSERT(dt_object_exists(dt));
 267         LASSERT(obj->oo_dn);
 268
 269         for (i = 0; i < npages; i++) {
 270                 if (lnb[i].lnb_page == NULL)
 271                         continue;
 272                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 273                         /* this is anonymous page allocated for copy-write */
 274                         lnb[i].lnb_page->mapping = NULL;
 275                         __free_page(lnb[i].lnb_page);
 276                         atomic_dec(&osd->od_zerocopy_alloc);
 277                 } else {
 278                         /* see comment in osd_bufs_get_read() */
 279                         ptr = (unsigned long)lnb[i].lnb_data;
 280                         if (ptr & 1UL) {
 281                                 ptr &= ~1UL;
 282                                 dmu_buf_rele((void *)ptr, osd_0copy_tag);
 283                                 atomic_dec(&osd->od_zerocopy_pin);
 284                         } else if (lnb[i].lnb_data != NULL) {
 285                                 int j, apages, abufsz;
 286                                 abufsz = arc_buf_size(lnb[i].lnb_data);
 287                                 apages = abufsz / PAGE_SIZE;
 288                                 /* these references to pages must be invalidated
 289                                  * to prevent access in osd_bufs_put() */
 290                                 for (j = 0; j < apages; j++)
 291                                         lnb[i + j].lnb_page = NULL;
 292                                 dmu_return_arcbuf(lnb[i].lnb_data);
 293                                 atomic_dec(&osd->od_zerocopy_loan);
 294                         }
 295                 }
 296                 lnb[i].lnb_page = NULL;
 297                 lnb[i].lnb_data = NULL;
 298         }
 299
 300         return 0;
 301 }
 302
 303 static inline struct page *kmem_to_page(void *addr)
 304 {
 305         LASSERT(!((unsigned long)addr & ~PAGE_MASK));
 306         if (is_vmalloc_addr(addr))
 307                 return vmalloc_to_page(addr);
 308         else
 309                 return virt_to_page(addr);
 310 }
 311
 312 /**
 313  * Prepare buffers for read.
 314  *
 315  * The function maps the range described by \a off and \a len to \a lnb array.
 316  * dmu_buf_hold_array_by_bonus() finds/creates appropriate ARC buffers, then
 317  * we fill \a lnb array with the pages storing ARC buffers. Notice the current
 318  * implementationt passes TRUE to dmu_buf_hold_array_by_bonus() to fill ARC
 319  * buffers with actual data, I/O is done in the conext of osd_bufs_get_read().
 320  * A better implementation would just return the buffers (potentially unfilled)
 321  * and subsequent osd_read_prep() would do I/O for many ranges concurrently.
 322  *
 323  * \param[in] env       environment
 324  * \param[in] obj       object
 325  * \param[in] off       offset in bytes
 326  * \param[in] len       the number of bytes to access
 327  * \param[out] lnb      array of local niobufs pointing to the buffers with data
 328  *
 329  * \retval              0 for success
 330  * \retval              negative error number of failure
 331  */
 332 static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
 333                              loff_t off, ssize_t len, struct niobuf_local *lnb,
 334                              int maxlnb)
 335 {
 336         struct osd_device *osd = osd_obj2dev(obj);
 337         int rc, i, numbufs, npages = 0, drop_cache = 0;
 338         ktime_t start = ktime_get();
 339         dmu_buf_t **dbp;
 340         s64 delta_ms;
 341
 342         ENTRY;
 343         record_start_io(osd, READ, 0);
 344
 345         if (obj->oo_attr.la_size >= osd->od_readcache_max_filesize)
 346                 drop_cache = 1;
 347
 348         /* grab buffers for read:
 349          * OSD API let us to grab buffers first, then initiate IO(s)
 350          * so that all required IOs will be done in parallel, but at the
 351          * moment DMU doesn't provide us with a method to grab buffers.
 352          * If we discover this is a vital for good performance we
 353          * can get own replacement for dmu_buf_hold_array_by_bonus().
 354          */
 355         while (len > 0 &&
 356                (obj->oo_dn->dn_datablkshift != 0 ||
 357                 off < obj->oo_dn->dn_datablksz)) {
 358                 if (obj->oo_dn->dn_datablkshift == 0 &&
 359                     off + len > obj->oo_dn->dn_datablksz)
 360                         len = obj->oo_dn->dn_datablksz - off;
 361
 362                 dbp = NULL;
 363                 if (unlikely(npages >= maxlnb))
 364                         GOTO(err, rc = -EOVERFLOW);
 365
 366                 rc = -dmu_buf_hold_array_by_bonus(&obj->oo_dn->dn_bonus->db,
 367                                                   off, len, TRUE, osd_0copy_tag,
 368                                                   &numbufs, &dbp);
 369                 if (unlikely(rc))
 370                         GOTO(err, rc);
 371
 372                 for (i = 0; i < numbufs; i++) {
 373                         int bufoff, tocpy, thispage;
 374                         void *dbf = dbp[i];
 375
 376                         LASSERT(len > 0);
 377
 378                         atomic_inc(&osd->od_zerocopy_pin);
 379
 380                         bufoff = off - dbp[i]->db_offset;
 381                         tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
 382
 383                         /* kind of trick to differentiate dbuf vs. arcbuf */
 384                         LASSERT(((unsigned long)dbp[i] & 1) == 0);
 385                         dbf = (void *) ((unsigned long)dbp[i] | 1);
 386
 387                         while (tocpy > 0) {
 388                                 if (unlikely(npages >= maxlnb))
 389                                         GOTO(err, rc = -EOVERFLOW);
 390
 391                                 thispage = PAGE_SIZE;
 392                                 thispage -= bufoff & (PAGE_SIZE - 1);
 393                                 thispage = min(tocpy, thispage);
 394
 395                                 lnb->lnb_rc = 0;
 396                                 lnb->lnb_file_offset = off;
 397                                 lnb->lnb_page_offset = bufoff & ~PAGE_MASK;
 398                                 lnb->lnb_len = thispage;
 399                                 lnb->lnb_page = kmem_to_page(dbp[i]->db_data +
 400                                                              bufoff);
 401                                 /* mark just a single slot: we need this
 402                                  * reference to dbuf to be released once */
 403                                 lnb->lnb_data = dbf;
 404                                 dbf = NULL;
 405
 406                                 tocpy -= thispage;
 407                                 len -= thispage;
 408                                 bufoff += thispage;
 409                                 off += thispage;
 410
 411                                 npages++;
 412                                 lnb++;
 413                         }
 414
 415                         if (drop_cache)
 416                                 dbuf_set_pending_evict(dbp[i]);
 417
 418                         /* steal dbuf so dmu_buf_rele_array() can't release
 419                          * it */
 420                         dbp[i] = NULL;
 421                 }
 422
 423                 dmu_buf_rele_array(dbp, numbufs, osd_0copy_tag);
 424         }
 425
 426         delta_ms = ktime_ms_delta(ktime_get(), start);
 427         record_end_io(osd, READ, delta_ms, npages * PAGE_SIZE, npages);
 428
 429         RETURN(npages);
 430
 431 err:
 432         LASSERT(rc < 0);
 433         if (dbp)
 434                 dmu_buf_rele_array(dbp, numbufs, osd_0copy_tag);
 435         osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
 436         RETURN(rc);
 437 }
 438
 439 static inline arc_buf_t *osd_request_arcbuf(dnode_t *dn, size_t bs)
 440 {
 441         arc_buf_t *abuf;
 442
 443         abuf = dmu_request_arcbuf(&dn->dn_bonus->db, bs);
 444         if (unlikely(!abuf))
 445                 return ERR_PTR(-ENOMEM);
 446
 447 #if ZFS_VERSION_CODE < OBD_OCD_VERSION(0, 7, 0, 0)
 448         /**
 449          * ZFS prior to 0.7.0 doesn't guarantee PAGE_SIZE alignment for zio
 450          * blocks smaller than (PAGE_SIZE << 2). This poses a problem of
 451          * setting up page array for RDMA transfer. See LU-9305.
 452          */
 453         if ((unsigned long)abuf->b_data & ~PAGE_MASK) {
 454                 dmu_return_arcbuf(abuf);
 455                 return NULL;
 456         }
 457 #endif
 458
 459         return abuf;
 460 }
 461
 462 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
 463                               loff_t off, ssize_t len, struct niobuf_local *lnb,
 464                               int maxlnb)
 465 {
 466         struct osd_device *osd = osd_obj2dev(obj);
 467         int                poff, plen, off_in_block, sz_in_block;
 468         int                rc, i = 0, npages = 0;
 469         dnode_t *dn = obj->oo_dn;
 470         arc_buf_t *abuf;
 471         uint32_t bs = dn->dn_datablksz;
 472         ENTRY;
 473
 474         /*
 475          * currently only full blocks are subject to zerocopy approach:
 476          * so that we're sure nobody is trying to update the same block
 477          */
 478         while (len > 0) {
 479                 if (unlikely(npages >= maxlnb))
 480                         GOTO(out_err, rc = -EOVERFLOW);
 481
 482                 off_in_block = off & (bs - 1);
 483                 sz_in_block = min_t(int, bs - off_in_block, len);
 484
 485                 abuf = NULL;
 486                 if (sz_in_block == bs) {
 487                         /* full block, try to use zerocopy */
 488                         abuf = osd_request_arcbuf(dn, bs);
 489                         if (unlikely(IS_ERR(abuf)))
 490                                 GOTO(out_err, rc = PTR_ERR(abuf));
 491                 }
 492
 493                 if (abuf != NULL) {
 494                         atomic_inc(&osd->od_zerocopy_loan);
 495
 496                         /* go over pages arcbuf contains, put them as
 497                          * local niobufs for ptlrpc's bulks */
 498                         while (sz_in_block > 0) {
 499                                 plen = min_t(int, sz_in_block, PAGE_SIZE);
 500
 501                                 if (unlikely(npages >= maxlnb))
 502                                         GOTO(out_err, rc = -EOVERFLOW);
 503
 504                                 lnb[i].lnb_file_offset = off;
 505                                 lnb[i].lnb_page_offset = 0;
 506                                 lnb[i].lnb_len = plen;
 507                                 lnb[i].lnb_rc = 0;
 508                                 if (sz_in_block == bs)
 509                                         lnb[i].lnb_data = abuf;
 510                                 else
 511                                         lnb[i].lnb_data = NULL;
 512
 513                                 /* this one is not supposed to fail */
 514                                 lnb[i].lnb_page = kmem_to_page(abuf->b_data +
 515                                                         off_in_block);
 516                                 LASSERT(lnb[i].lnb_page);
 517
 518                                 lprocfs_counter_add(osd->od_stats,
 519                                                 LPROC_OSD_ZEROCOPY_IO, 1);
 520
 521                                 sz_in_block -= plen;
 522                                 len -= plen;
 523                                 off += plen;
 524                                 off_in_block += plen;
 525                                 i++;
 526                                 npages++;
 527                         }
 528                 } else {
 529                         if (off_in_block == 0 && len < bs &&
 530                                         off + len >= obj->oo_attr.la_size)
 531                                 lprocfs_counter_add(osd->od_stats,
 532                                                 LPROC_OSD_TAIL_IO, 1);
 533
 534                         /* can't use zerocopy, allocate temp. buffers */
 535                         poff = off & (PAGE_SIZE - 1);
 536                         while (sz_in_block > 0) {
 537                                 plen = min_t(int, poff + sz_in_block,
 538                                              PAGE_SIZE);
 539                                 plen -= poff;
 540
 541                                 if (unlikely(npages >= maxlnb))
 542                                         GOTO(out_err, rc = -EOVERFLOW);
 543
 544                                 lnb[i].lnb_file_offset = off;
 545                                 lnb[i].lnb_page_offset = poff;
 546                                 poff = 0;
 547
 548                                 lnb[i].lnb_len = plen;
 549                                 lnb[i].lnb_rc = 0;
 550                                 lnb[i].lnb_data = NULL;
 551
 552                                 lnb[i].lnb_page = alloc_page(OSD_GFP_IO);
 553                                 if (unlikely(lnb[i].lnb_page == NULL))
 554                                         GOTO(out_err, rc = -ENOMEM);
 555
 556                                 LASSERT(lnb[i].lnb_page->mapping == NULL);
 557                                 lnb[i].lnb_page->mapping = (void *)obj;
 558
 559                                 atomic_inc(&osd->od_zerocopy_alloc);
 560                                 lprocfs_counter_add(osd->od_stats,
 561                                                 LPROC_OSD_COPY_IO, 1);
 562
 563                                 sz_in_block -= plen;
 564                                 len -= plen;
 565                                 off += plen;
 566                                 i++;
 567                                 npages++;
 568                         }
 569                 }
 570         }
 571
 572         RETURN(npages);
 573
 574 out_err:
 575         osd_bufs_put(env, &obj->oo_dt, lnb, npages);
 576         RETURN(rc);
 577 }
 578
 579 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
 580                         loff_t offset, ssize_t len, struct niobuf_local *lnb,
 581                         int maxlnb, enum dt_bufs_type rw)
 582 {
 583         struct osd_object *obj  = osd_dt_obj(dt);
 584         int                rc;
 585
 586         LASSERT(dt_object_exists(dt));
 587         LASSERT(obj->oo_dn);
 588
 589         if (rw & DT_BUFS_TYPE_WRITE)
 590                 rc = osd_bufs_get_write(env, obj, offset, len, lnb, maxlnb);
 591         else
 592                 rc = osd_bufs_get_read(env, obj, offset, len, lnb, maxlnb);
 593
 594         return rc;
 595 }
 596
 597 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
 598                         struct niobuf_local *lnb, int npages)
 599 {
 600         struct osd_object *obj = osd_dt_obj(dt);
 601
 602         LASSERT(dt_object_exists(dt));
 603         LASSERT(obj->oo_dn);
 604
 605         return 0;
 606 }
 607
 608 static inline uint64_t osd_roundup2blocksz(uint64_t size,
 609                                            uint64_t offset,
 610                                            uint32_t blksz)
 611 {
 612         LASSERT(blksz > 0);
 613
 614         size += offset % blksz;
 615
 616         if (likely(is_power_of_2(blksz)))
 617                 return PO2_ROUNDUP_TYPED(size, blksz, uint64_t);
 618
 619         size += blksz - 1;
 620         do_div(size, blksz);
 621         return size * blksz;
 622 }
 623
 624 static int osd_declare_write_commit(const struct lu_env *env,
 625                                     struct dt_object *dt,
 626                                     struct niobuf_local *lnb, int npages,
 627                                     struct thandle *th)
 628 {
 629         struct osd_object  *obj = osd_dt_obj(dt);
 630         struct osd_device  *osd = osd_obj2dev(obj);
 631         struct osd_thandle *oh;
 632         uint64_t            offset = 0;
 633         uint32_t            size = 0;
 634         uint32_t blksz = obj->oo_dn->dn_datablksz;
 635         int                 i, rc, flags = 0;
 636         bool synced = false;
 637         long long           space = 0;
 638         struct page        *last_page = NULL;
 639         unsigned long       discont_pages = 0;
 640         enum osd_qid_declare_flags declare_flags = OSD_QID_BLK;
 641         ENTRY;
 642
 643         LASSERT(dt_object_exists(dt));
 644         LASSERT(obj->oo_dn);
 645
 646         LASSERT(lnb);
 647         LASSERT(npages > 0);
 648
 649         oh = container_of0(th, struct osd_thandle, ot_super);
 650
 651         for (i = 0; i < npages; i++) {
 652                 if (last_page && lnb[i].lnb_page->index != (last_page->index + 1))
 653                         ++discont_pages;
 654                 last_page = lnb[i].lnb_page;
 655                 if (lnb[i].lnb_rc)
 656                         /* ENOSPC, network RPC error, etc.
 657                          * We don't want to book space for pages which will be
 658                          * skipped in osd_write_commit(). Hence we skip pages
 659                          * with lnb_rc != 0 here too */
 660                         continue;
 661                 /* ignore quota for the whole request if any page is from
 662                  * client cache or written by root.
 663                  *
 664                  * XXX once we drop the 1.8 client support, the checking
 665                  * for whether page is from cache can be simplified as:
 666                  * !(lnb[i].flags & OBD_BRW_SYNC)
 667                  *
 668                  * XXX we could handle this on per-lnb basis as done by
 669                  * grant. */
 670                 if ((lnb[i].lnb_flags & OBD_BRW_NOQUOTA) ||
 671                     (lnb[i].lnb_flags & (OBD_BRW_FROM_GRANT | OBD_BRW_SYNC)) ==
 672                     OBD_BRW_FROM_GRANT)
 673                         declare_flags |= OSD_QID_FORCE;
 674
 675                 if (size == 0) {
 676                         /* first valid lnb */
 677                         offset = lnb[i].lnb_file_offset;
 678                         size = lnb[i].lnb_len;
 679                         continue;
 680                 }
 681                 if (offset + size == lnb[i].lnb_file_offset) {
 682                         /* this lnb is contiguous to the previous one */
 683                         size += lnb[i].lnb_len;
 684                         continue;
 685                 }
 686
 687                 osd_tx_hold_write(oh->ot_tx, obj->oo_dn->dn_object,
 688                                   obj->oo_dn, offset, size);
 689                 /* Estimating space to be consumed by a write is rather
 690                  * complicated with ZFS. As a consequence, we don't account for
 691                  * indirect blocks and just use as a rough estimate the worse
 692                  * case where the old space is being held by a snapshot. Quota
 693                  * overrun will be adjusted once the operation is committed, if
 694                  * required. */
 695                 space += osd_roundup2blocksz(size, offset, blksz);
 696
 697                 offset = lnb[i].lnb_file_offset;
 698                 size = lnb[i].lnb_len;
 699         }
 700
 701         if (size) {
 702                 osd_tx_hold_write(oh->ot_tx, obj->oo_dn->dn_object, obj->oo_dn,
 703                                   offset, size);
 704                 space += osd_roundup2blocksz(size, offset, blksz);
 705         }
 706
 707         /* backend zfs filesystem might be configured to store multiple data
 708          * copies */
 709         space  *= osd->od_os->os_copies;
 710         space   = toqb(space);
 711         CDEBUG(D_QUOTA, "writing %d pages, reserving %lldK of quota space\n",
 712                npages, space);
 713
 714         record_start_io(osd, WRITE, discont_pages);
 715 retry:
 716         /* acquire quota space if needed */
 717         rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 718                                obj->oo_attr.la_gid, obj->oo_attr.la_projid,
 719                                space, oh, &flags, declare_flags);
 720
 721         if (!synced && rc == -EDQUOT && (flags & QUOTA_FL_SYNC) != 0) {
 722                 dt_sync(env, th->th_dev);
 723                 synced = true;
 724                 CDEBUG(D_QUOTA, "retry after sync\n");
 725                 flags = 0;
 726                 goto retry;
 727         }
 728
 729         /* we need only to store the overquota flags in the first lnb for
 730          * now, once we support multiple objects BRW, this code needs be
 731          * revised. */
 732         if (flags & QUOTA_FL_OVER_USRQUOTA)
 733                 lnb[0].lnb_flags |= OBD_BRW_OVER_USRQUOTA;
 734         if (flags & QUOTA_FL_OVER_GRPQUOTA)
 735                 lnb[0].lnb_flags |= OBD_BRW_OVER_GRPQUOTA;
 736 #ifdef ZFS_PROJINHERIT
 737         if (flags & QUOTA_FL_OVER_PRJQUOTA)
 738                 lnb[0].lnb_flags |= OBD_BRW_OVER_PRJQUOTA;
 739 #endif
 740
 741         RETURN(rc);
 742 }
 743
 744 /**
 745  * Policy to grow ZFS block size by write pattern.
 746  * For sequential write, it grows block size gradually until it reaches the
 747  * maximum blocksize the dataset can support. Otherwise, it will pick a
 748  * a block size by the writing region of this I/O.
 749  */
 750 static int osd_grow_blocksize(struct osd_object *obj, struct osd_thandle *oh,
 751                               uint64_t start, uint64_t end)
 752 {
 753         struct osd_device       *osd = osd_obj2dev(obj);
 754         dnode_t *dn = obj->oo_dn;
 755         uint32_t                 blksz;
 756         int                      rc = 0;
 757
 758         ENTRY;
 759
 760         if (dn->dn_maxblkid > 0) /* can't change block size */
 761                 GOTO(out, rc);
 762
 763         if (dn->dn_datablksz >= osd->od_max_blksz)
 764                 GOTO(out, rc);
 765
 766         down_write(&obj->oo_guard);
 767
 768         blksz = dn->dn_datablksz;
 769         if (blksz >= osd->od_max_blksz) /* check again after grabbing lock */
 770                 GOTO(out_unlock, rc);
 771
 772         /* now ZFS can support up to 16MB block size, and if the write
 773          * is sequential, it just increases the block size gradually */
 774         if (start <= blksz) { /* sequential */
 775                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz, end);
 776         } else { /* sparse, pick a block size by write region */
 777                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz,
 778                                         end - start);
 779         }
 780
 781         if (!is_power_of_2(blksz))
 782                 blksz = size_roundup_power2(blksz);
 783
 784         if (blksz > dn->dn_datablksz) {
 785                 rc = -dmu_object_set_blocksize(osd->od_os, dn->dn_object,
 786                                                blksz, 0, oh->ot_tx);
 787                 LASSERT(ergo(rc == 0, dn->dn_datablksz >= blksz));
 788                 if (rc < 0)
 789                         CDEBUG(D_INODE, "object "DFID": change block size"
 790                                "%u -> %u error rc = %d\n",
 791                                PFID(lu_object_fid(&obj->oo_dt.do_lu)),
 792                                dn->dn_datablksz, blksz, rc);
 793         }
 794         EXIT;
 795 out_unlock:
 796         up_write(&obj->oo_guard);
 797 out:
 798         return rc;
 799 }
 800
 801 static void osd_evict_dbufs_after_write(struct osd_object *obj,
 802                                         loff_t off, ssize_t len)
 803 {
 804         dmu_buf_t **dbp;
 805         int i, rc, numbufs;
 806
 807         rc = -dmu_buf_hold_array_by_bonus(&obj->oo_dn->dn_bonus->db, off, len,
 808                                           TRUE, osd_0copy_tag, &numbufs, &dbp);
 809         if (unlikely(rc))
 810                 return;
 811
 812         for (i = 0; i < numbufs; i++)
 813                 dbuf_set_pending_evict(dbp[i]);
 814
 815         dmu_buf_rele_array(dbp, numbufs, osd_0copy_tag);
 816 }
 817
 818 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 819                         struct niobuf_local *lnb, int npages,
 820                         struct thandle *th)
 821 {
 822         struct osd_object  *obj  = osd_dt_obj(dt);
 823         struct osd_device  *osd = osd_obj2dev(obj);
 824         struct osd_thandle *oh;
 825         uint64_t            new_size = 0;
 826         int                 i, abufsz, rc = 0, drop_cache = 0;
 827         unsigned long      iosize = 0;
 828         ENTRY;
 829
 830         LASSERT(dt_object_exists(dt));
 831         LASSERT(obj->oo_dn);
 832
 833         LASSERT(th != NULL);
 834         oh = container_of0(th, struct osd_thandle, ot_super);
 835
 836         /* adjust block size. Assume the buffers are sorted. */
 837         (void)osd_grow_blocksize(obj, oh, lnb[0].lnb_file_offset,
 838                                  lnb[npages - 1].lnb_file_offset +
 839                                  lnb[npages - 1].lnb_len);
 840
 841         if (obj->oo_attr.la_size >= osd->od_readcache_max_filesize ||
 842             lnb[npages - 1].lnb_file_offset + lnb[npages - 1].lnb_len >=
 843             osd->od_readcache_max_filesize)
 844                 drop_cache = 1;
 845
 846         if (OBD_FAIL_CHECK(OBD_FAIL_OST_MAPBLK_ENOSPC))
 847                 RETURN(-ENOSPC);
 848
 849         /* LU-8791: take oo_guard to avoid the deadlock that changing block
 850          * size and assigning arcbuf take place at the same time.
 851          *
 852          * Thread 1:
 853          * osd_write_commit()
 854          *  -> osd_grow_blocksize() with osd_object::oo_guard held
 855          *   -> dmu_object_set_blocksize()
 856          *    -> dnode_set_blksz(), with dnode_t::dn_struct_rwlock
 857          *       write lock held
 858          *     -> dbuf_new_size()
 859          *      -> dmu_buf_will_dirty()
 860          *       -> dbuf_read()
 861          *        -> wait for the dbuf state to change
 862          * Thread 2:
 863          * osd_write_commit()
 864          *  -> dmu_assign_arcbuf()
 865          *   -> dbuf_assign_arcbuf(), set dbuf state to DB_FILL
 866          *    -> dbuf_dirty()
 867          *     -> try to hold the read lock of dnode_t::dn_struct_rwlock
 868          *
 869          * By taking the read lock, it can avoid thread 2 to enter into the
 870          * critical section of assigning the arcbuf, while thread 1 is
 871          * changing the block size.
 872          */
 873         down_read(&obj->oo_guard);
 874         for (i = 0; i < npages; i++) {
 875                 CDEBUG(D_INODE, "write %u bytes at %u\n",
 876                         (unsigned) lnb[i].lnb_len,
 877                         (unsigned) lnb[i].lnb_file_offset);
 878
 879                 if (lnb[i].lnb_rc) {
 880                         /* ENOSPC, network RPC error, etc.
 881                          * Unlike ldiskfs, zfs allocates new blocks on rewrite,
 882                          * so we skip this page if lnb_rc is set to -ENOSPC */
 883                         CDEBUG(D_INODE, "obj "DFID": skipping lnb[%u]: rc=%d\n",
 884                                 PFID(lu_object_fid(&dt->do_lu)), i,
 885                                 lnb[i].lnb_rc);
 886                         continue;
 887                 }
 888
 889                 if (new_size < lnb[i].lnb_file_offset + lnb[i].lnb_len)
 890                         new_size = lnb[i].lnb_file_offset + lnb[i].lnb_len;
 891                 if (lnb[i].lnb_page == NULL)
 892                         continue;
 893
 894                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 895                         osd_dmu_write(osd, obj->oo_dn, lnb[i].lnb_file_offset,
 896                                       lnb[i].lnb_len, kmap(lnb[i].lnb_page) +
 897                                       lnb[i].lnb_page_offset, oh->ot_tx);
 898                         kunmap(lnb[i].lnb_page);
 899                         iosize += lnb[i].lnb_len;
 900                         abufsz = lnb[i].lnb_len; /* to drop cache below */
 901                 } else if (lnb[i].lnb_data) {
 902                         int j, apages;
 903                         LASSERT(((unsigned long)lnb[i].lnb_data & 1) == 0);
 904                         /* buffer loaned for zerocopy, try to use it.
 905                          * notice that dmu_assign_arcbuf() is smart
 906                          * enough to recognize changed blocksize
 907                          * in this case it fallbacks to dmu_write() */
 908                         abufsz = arc_buf_size(lnb[i].lnb_data);
 909                         LASSERT(abufsz & PAGE_MASK);
 910                         apages = abufsz / PAGE_SIZE;
 911                         LASSERT(i + apages <= npages);
 912                         /* these references to pages must be invalidated
 913                          * to prevent access in osd_bufs_put() */
 914                         for (j = 0; j < apages; j++)
 915                                 lnb[i + j].lnb_page = NULL;
 916                         dmu_assign_arcbuf(&obj->oo_dn->dn_bonus->db,
 917                                           lnb[i].lnb_file_offset,
 918                                           lnb[i].lnb_data, oh->ot_tx);
 919                         /* drop the reference, otherwise osd_put_bufs()
 920                          * will be releasing it - bad! */
 921                         lnb[i].lnb_data = NULL;
 922                         atomic_dec(&osd->od_zerocopy_loan);
 923                         iosize += abufsz;
 924                 } else {
 925                         /* we don't want to deal with cache if nothing
 926                          * has been send to ZFS at this step */
 927                         continue;
 928                 }
 929
 930                 if (!drop_cache)
 931                         continue;
 932
 933                 /* we have to mark dbufs for eviction here because
 934                  * dmu_assign_arcbuf() may create a new dbuf for
 935                  * loaned abuf */
 936                 osd_evict_dbufs_after_write(obj, lnb[i].lnb_file_offset,
 937                                             abufsz);
 938         }
 939         up_read(&obj->oo_guard);
 940
 941         if (unlikely(new_size == 0)) {
 942                 /* no pages to write, no transno is needed */
 943                 th->th_local = 1;
 944                 /* it is important to return 0 even when all lnb_rc == -ENOSPC
 945                  * since ofd_commitrw_write() retries several times on ENOSPC */
 946                 record_end_io(osd, WRITE, 0, 0, 0);
 947                 RETURN(0);
 948         }
 949
 950         write_lock(&obj->oo_attr_lock);
 951         if (obj->oo_attr.la_size < new_size) {
 952                 obj->oo_attr.la_size = new_size;
 953                 write_unlock(&obj->oo_attr_lock);
 954                 /* osd_object_sa_update() will be copying directly from
 955                  * oo_attr into dbuf. any update within a single txg will copy
 956                  * the most actual */
 957                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 958                                           &obj->oo_attr.la_size, 8, oh);
 959         } else {
 960                 write_unlock(&obj->oo_attr_lock);
 961         }
 962
 963         record_end_io(osd, WRITE, 0, iosize, npages);
 964
 965         RETURN(rc);
 966 }
 967
 968 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 969                         struct niobuf_local *lnb, int npages)
 970 {
 971         struct osd_object *obj  = osd_dt_obj(dt);
 972         int                i;
 973         loff_t             eof;
 974
 975         LASSERT(dt_object_exists(dt));
 976         LASSERT(obj->oo_dn);
 977
 978         read_lock(&obj->oo_attr_lock);
 979         eof = obj->oo_attr.la_size;
 980         read_unlock(&obj->oo_attr_lock);
 981
 982         for (i = 0; i < npages; i++) {
 983                 if (unlikely(lnb[i].lnb_rc < 0))
 984                         continue;
 985
 986                 lnb[i].lnb_rc = lnb[i].lnb_len;
 987
 988                 if (lnb[i].lnb_file_offset + lnb[i].lnb_len >= eof) {
 989                         if (eof <= lnb[i].lnb_file_offset)
 990                                 lnb[i].lnb_rc = 0;
 991                         else
 992                                 lnb[i].lnb_rc = eof - lnb[i].lnb_file_offset;
 993
 994                         /* all subsequent rc should be 0 */
 995                         while (++i < npages)
 996                                 lnb[i].lnb_rc = 0;
 997                         break;
 998                 }
 999         }
1000
1001         return 0;
1002 }
1003
1004 /*
1005  * Punch/truncate an object
1006  *
1007  *      IN:     db  - dmu_buf of the object to free data in.
1008  *              off - start of section to free.
1009  *              len - length of section to free (DMU_OBJECT_END => to EOF).
1010  *
1011  *      RETURN: 0 if success
1012  *              error code if failure
1013  *
1014  * The transaction passed to this routine must have
1015  * dmu_tx_hold_sa() and if off < size, dmu_tx_hold_free()
1016  * called and then assigned to a transaction group.
1017  */
1018 static int __osd_object_punch(objset_t *os, dnode_t *dn, dmu_tx_t *tx,
1019                                 uint64_t size, uint64_t off, uint64_t len)
1020 {
1021         int rc = 0;
1022
1023         /* Assert that the transaction has been assigned to a
1024            transaction group. */
1025         LASSERT(tx->tx_txg != 0);
1026         /*
1027          * Nothing to do if file already at desired length.
1028          */
1029         if (len == DMU_OBJECT_END && size == off)
1030                 return 0;
1031
1032         /* XXX: dnode_free_range() can be used to save on dnode lookup */
1033         if (off < size)
1034                 dmu_free_range(os, dn->dn_object, off, len, tx);
1035
1036         return rc;
1037 }
1038
1039 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
1040                         __u64 start, __u64 end, struct thandle *th)
1041 {
1042         struct osd_object  *obj = osd_dt_obj(dt);
1043         struct osd_device  *osd = osd_obj2dev(obj);
1044         struct osd_thandle *oh;
1045         __u64               len;
1046         int                 rc = 0;
1047         ENTRY;
1048
1049         LASSERT(dt_object_exists(dt));
1050         LASSERT(osd_invariant(obj));
1051
1052         LASSERT(th != NULL);
1053         oh = container_of0(th, struct osd_thandle, ot_super);
1054
1055         write_lock(&obj->oo_attr_lock);
1056         /* truncate */
1057         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
1058                 len = DMU_OBJECT_END;
1059         else
1060                 len = end - start;
1061         write_unlock(&obj->oo_attr_lock);
1062
1063         rc = __osd_object_punch(osd->od_os, obj->oo_dn, oh->ot_tx,
1064                                 obj->oo_attr.la_size, start, len);
1065         /* set new size */
1066         if (len == DMU_OBJECT_END) {
1067                 write_lock(&obj->oo_attr_lock);
1068                 obj->oo_attr.la_size = start;
1069                 write_unlock(&obj->oo_attr_lock);
1070                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
1071                                           &obj->oo_attr.la_size, 8, oh);
1072         }
1073         RETURN(rc);
1074 }
1075
1076 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
1077                         __u64 start, __u64 end, struct thandle *handle)
1078 {
1079         struct osd_object  *obj = osd_dt_obj(dt);
1080         struct osd_device  *osd = osd_obj2dev(obj);
1081         struct osd_thandle *oh;
1082         __u64               len;
1083         ENTRY;
1084
1085         oh = container_of0(handle, struct osd_thandle, ot_super);
1086
1087         read_lock(&obj->oo_attr_lock);
1088         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
1089                 len = DMU_OBJECT_END;
1090         else
1091                 len = end - start;
1092
1093         /* declare we'll free some blocks ... */
1094         if (start < obj->oo_attr.la_size) {
1095                 read_unlock(&obj->oo_attr_lock);
1096                 dmu_tx_mark_netfree(oh->ot_tx);
1097                 dmu_tx_hold_free(oh->ot_tx, obj->oo_dn->dn_object, start, len);
1098         } else {
1099                 read_unlock(&obj->oo_attr_lock);
1100         }
1101
1102         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
1103                                  obj->oo_attr.la_gid, obj->oo_attr.la_projid,
1104                                  0, oh, NULL, OSD_QID_BLK));
1105 }
1106
1107 static int osd_ladvise(const struct lu_env *env, struct dt_object *dt,
1108                        __u64 start, __u64 end, enum lu_ladvise_type advice)
1109 {
1110         int     rc;
1111         ENTRY;
1112
1113         switch (advice) {
1114         default:
1115                 rc = -ENOTSUPP;
1116                 break;
1117         }
1118
1119         RETURN(rc);
1120 }
1121
1122 struct dt_body_operations osd_body_ops = {
1123         .dbo_read                       = osd_read,
1124         .dbo_declare_write              = osd_declare_write,
1125         .dbo_write                      = osd_write,
1126         .dbo_bufs_get                   = osd_bufs_get,
1127         .dbo_bufs_put                   = osd_bufs_put,
1128         .dbo_write_prep                 = osd_write_prep,
1129         .dbo_declare_write_commit       = osd_declare_write_commit,
1130         .dbo_write_commit               = osd_write_commit,
1131         .dbo_read_prep                  = osd_read_prep,
1132         .dbo_declare_punch              = osd_declare_punch,
1133         .dbo_punch                      = osd_punch,
1134         .dbo_ladvise                    = osd_ladvise,
1135 };
1136
1137 struct dt_body_operations osd_body_scrub_ops = {
1138         .dbo_read                       = osd_read_no_record,
1139         .dbo_declare_write              = osd_declare_write,
1140         .dbo_write                      = osd_write,
1141 };