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  * Copyright (c) 2012, 2015, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/osd-zfs/osd_io.c
  37  *
  38  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  39  * Author: Mike Pershin <tappro@whamcloud.com>
  40  */
  41
  42 #define DEBUG_SUBSYSTEM S_OSD
  43
  44 #include <lustre_ver.h>
  45 #include <libcfs/libcfs.h>
  46 #include <obd_support.h>
  47 #include <lustre_net.h>
  48 #include <obd.h>
  49 #include <obd_class.h>
  50 #include <lustre_disk.h>
  51 #include <lustre_fid.h>
  52 #include <lustre/lustre_idl.h>  /* LLOG_MIN_CHUNK_SIZE definition */
  53
  54 #include "osd_internal.h"
  55
  56 #include <sys/dnode.h>
  57 #include <sys/dbuf.h>
  58 #include <sys/spa.h>
  59 #include <sys/stat.h>
  60 #include <sys/zap.h>
  61 #include <sys/spa_impl.h>
  62 #include <sys/zfs_znode.h>
  63 #include <sys/dmu_tx.h>
  64 #include <sys/dmu_objset.h>
  65 #include <sys/dsl_prop.h>
  66 #include <sys/sa_impl.h>
  67 #include <sys/txg.h>
  68
  69 static char *osd_zerocopy_tag = "zerocopy";
  70
  71
  72 static void record_start_io(struct osd_device *osd, int rw, int discont_pages)
  73 {
  74         struct obd_histogram *h = osd->od_brw_stats.hist;
  75
  76         if (rw == READ) {
  77                 atomic_inc(&osd->od_r_in_flight);
  78                 lprocfs_oh_tally(&h[BRW_R_RPC_HIST],
  79                                  atomic_read(&osd->od_r_in_flight));
  80                 lprocfs_oh_tally(&h[BRW_R_DISCONT_PAGES], discont_pages);
  81
  82         } else {
  83                 atomic_inc(&osd->od_w_in_flight);
  84                 lprocfs_oh_tally(&h[BRW_W_RPC_HIST],
  85                                  atomic_read(&osd->od_w_in_flight));
  86                 lprocfs_oh_tally(&h[BRW_W_DISCONT_PAGES], discont_pages);
  87
  88         }
  89 }
  90
  91 static void record_end_io(struct osd_device *osd, int rw,
  92                           unsigned long elapsed, int disksize, int npages)
  93 {
  94         struct obd_histogram *h = osd->od_brw_stats.hist;
  95
  96         if (rw == READ) {
  97                 atomic_dec(&osd->od_r_in_flight);
  98                 lprocfs_oh_tally_log2(&h[BRW_R_PAGES], npages);
  99                 if (disksize > 0)
 100                         lprocfs_oh_tally_log2(&h[BRW_R_DISK_IOSIZE], disksize);
 101                 if (elapsed)
 102                         lprocfs_oh_tally_log2(&h[BRW_R_IO_TIME], elapsed);
 103
 104         } else {
 105                 atomic_dec(&osd->od_w_in_flight);
 106                 lprocfs_oh_tally_log2(&h[BRW_W_PAGES], npages);
 107                 if (disksize > 0)
 108                         lprocfs_oh_tally_log2(&h[BRW_W_DISK_IOSIZE], disksize);
 109                 if (elapsed)
 110                         lprocfs_oh_tally_log2(&h[BRW_W_IO_TIME], elapsed);
 111         }
 112 }
 113
 114 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
 115                         struct lu_buf *buf, loff_t *pos)
 116 {
 117         struct osd_object *obj  = osd_dt_obj(dt);
 118         struct osd_device *osd = osd_obj2dev(obj);
 119         uint64_t           old_size;
 120         int                size = buf->lb_len;
 121         int                rc;
 122         unsigned long      start;
 123
 124         LASSERT(dt_object_exists(dt));
 125         LASSERT(obj->oo_db);
 126
 127         start = cfs_time_current();
 128
 129         read_lock(&obj->oo_attr_lock);
 130         old_size = obj->oo_attr.la_size;
 131         read_unlock(&obj->oo_attr_lock);
 132
 133         if (*pos + size > old_size) {
 134                 if (old_size < *pos)
 135                         return 0;
 136                 else
 137                         size = old_size - *pos;
 138         }
 139
 140         record_start_io(osd, READ, 0);
 141
 142         rc = -dmu_read(osd->od_os, obj->oo_db->db_object, *pos, size,
 143                         buf->lb_buf, DMU_READ_PREFETCH);
 144
 145         record_end_io(osd, READ, cfs_time_current() - start, size,
 146                       size >> PAGE_CACHE_SHIFT);
 147         if (rc == 0) {
 148                 rc = size;
 149                 *pos += size;
 150         }
 151         return rc;
 152 }
 153
 154 static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
 155                                 const struct lu_buf *buf, loff_t pos,
 156                                 struct thandle *th)
 157 {
 158         struct osd_object  *obj  = osd_dt_obj(dt);
 159         struct osd_device  *osd = osd_obj2dev(obj);
 160         struct osd_thandle *oh;
 161         uint64_t            oid;
 162         ENTRY;
 163
 164         oh = container_of0(th, struct osd_thandle, ot_super);
 165
 166         /* in some cases declare can race with creation (e.g. llog)
 167          * and we need to wait till object is initialized. notice
 168          * LOHA_EXISTs is supposed to be the last step in the
 169          * initialization */
 170
 171         /* declare possible size change. notice we can't check
 172          * current size here as another thread can change it */
 173
 174         if (dt_object_exists(dt)) {
 175                 LASSERT(obj->oo_db);
 176                 oid = obj->oo_db->db_object;
 177
 178                 dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 179         } else {
 180                 oid = DMU_NEW_OBJECT;
 181                 dmu_tx_hold_sa_create(oh->ot_tx, ZFS_SA_BASE_ATTR_SIZE);
 182         }
 183
 184         /* XXX: we still miss for append declaration support in ZFS
 185          *      -1 means append which is used by llog mostly, llog
 186          *      can grow upto LLOG_MIN_CHUNK_SIZE*8 records */
 187         if (pos == -1)
 188                 pos = max_t(loff_t, 256 * 8 * LLOG_MIN_CHUNK_SIZE,
 189                             obj->oo_attr.la_size + (2 << 20));
 190         dmu_tx_hold_write(oh->ot_tx, oid, pos, buf->lb_len);
 191
 192         /* dt_declare_write() is usually called for system objects, such
 193          * as llog or last_rcvd files. We needn't enforce quota on those
 194          * objects, so always set the lqi_space as 0. */
 195         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 196                                  obj->oo_attr.la_gid, 0, oh, true, NULL,
 197                                  false));
 198 }
 199
 200 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
 201                         const struct lu_buf *buf, loff_t *pos,
 202                         struct thandle *th, int ignore_quota)
 203 {
 204         struct osd_object  *obj  = osd_dt_obj(dt);
 205         struct osd_device  *osd = osd_obj2dev(obj);
 206         struct osd_thandle *oh;
 207         uint64_t            offset = *pos;
 208         int                 rc;
 209
 210         ENTRY;
 211
 212         LASSERT(dt_object_exists(dt));
 213         LASSERT(obj->oo_db);
 214
 215         LASSERT(th != NULL);
 216         oh = container_of0(th, struct osd_thandle, ot_super);
 217
 218         record_start_io(osd, WRITE, 0);
 219
 220         dmu_write(osd->od_os, obj->oo_db->db_object, offset,
 221                 (uint64_t)buf->lb_len, buf->lb_buf, oh->ot_tx);
 222         write_lock(&obj->oo_attr_lock);
 223         if (obj->oo_attr.la_size < offset + buf->lb_len) {
 224                 obj->oo_attr.la_size = offset + buf->lb_len;
 225                 write_unlock(&obj->oo_attr_lock);
 226                 /* osd_object_sa_update() will be copying directly from oo_attr
 227                  * into dbuf.  any update within a single txg will copy the
 228                  * most actual */
 229                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 230                                         &obj->oo_attr.la_size, 8, oh);
 231                 if (unlikely(rc))
 232                         GOTO(out, rc);
 233         } else {
 234                 write_unlock(&obj->oo_attr_lock);
 235         }
 236
 237         *pos += buf->lb_len;
 238         rc = buf->lb_len;
 239
 240 out:
 241         record_end_io(osd, WRITE, 0, buf->lb_len,
 242                       buf->lb_len >> PAGE_CACHE_SHIFT);
 243
 244         RETURN(rc);
 245 }
 246
 247 /*
 248  * XXX: for the moment I don't want to use lnb_flags for osd-internal
 249  *      purposes as it's not very well defined ...
 250  *      instead I use the lowest bit of the address so that:
 251  *        arc buffer:  .lnb_data = abuf          (arc we loan for write)
 252  *        dbuf buffer: .lnb_data = dbuf | 1      (dbuf we get for read)
 253  *        copy buffer: .lnb_page->mapping = obj (page we allocate for write)
 254  *
 255  *      bzzz, to blame
 256  */
 257 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
 258                         struct niobuf_local *lnb, int npages)
 259 {
 260         struct osd_object *obj  = osd_dt_obj(dt);
 261         struct osd_device *osd = osd_obj2dev(obj);
 262         unsigned long      ptr;
 263         int                i;
 264
 265         LASSERT(dt_object_exists(dt));
 266         LASSERT(obj->oo_db);
 267
 268         for (i = 0; i < npages; i++) {
 269                 if (lnb[i].lnb_page == NULL)
 270                         continue;
 271                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 272                         /* this is anonymous page allocated for copy-write */
 273                         lnb[i].lnb_page->mapping = NULL;
 274                         __free_page(lnb[i].lnb_page);
 275                         atomic_dec(&osd->od_zerocopy_alloc);
 276                 } else {
 277                         /* see comment in osd_bufs_get_read() */
 278                         ptr = (unsigned long)lnb[i].lnb_data;
 279                         if (ptr & 1UL) {
 280                                 ptr &= ~1UL;
 281                                 dmu_buf_rele((void *)ptr, osd_zerocopy_tag);
 282                                 atomic_dec(&osd->od_zerocopy_pin);
 283                         } else if (lnb[i].lnb_data != NULL) {
 284                                 dmu_return_arcbuf(lnb[i].lnb_data);
 285                                 atomic_dec(&osd->od_zerocopy_loan);
 286                         }
 287                 }
 288                 lnb[i].lnb_page = NULL;
 289                 lnb[i].lnb_data = NULL;
 290         }
 291
 292         return 0;
 293 }
 294
 295 static inline struct page *kmem_to_page(void *addr)
 296 {
 297         if (is_vmalloc_addr(addr))
 298                 return vmalloc_to_page(addr);
 299         else
 300                 return virt_to_page(addr);
 301 }
 302
 303 /**
 304  * Prepare buffers for read.
 305  *
 306  * The function maps the range described by \a off and \a len to \a lnb array.
 307  * dmu_buf_hold_array_by_bonus() finds/creates appropriate ARC buffers, then
 308  * we fill \a lnb array with the pages storing ARC buffers. Notice the current
 309  * implementationt passes TRUE to dmu_buf_hold_array_by_bonus() to fill ARC
 310  * buffers with actual data, I/O is done in the conext of osd_bufs_get_read().
 311  * A better implementation would just return the buffers (potentially unfilled)
 312  * and subsequent osd_read_prep() would do I/O for many ranges concurrently.
 313  *
 314  * \param[in] env       environment
 315  * \param[in] obj       object
 316  * \param[in] off       offset in bytes
 317  * \param[in] len       the number of bytes to access
 318  * \param[out] lnb      array of local niobufs pointing to the buffers with data
 319  *
 320  * \retval              0 for success
 321  * \retval              negative error number of failure
 322  */
 323 static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
 324                                 loff_t off, ssize_t len, struct niobuf_local *lnb)
 325 {
 326         struct osd_device *osd = osd_obj2dev(obj);
 327         unsigned long      start = cfs_time_current();
 328         int                rc, i, numbufs, npages = 0;
 329         dmu_buf_t        **dbp;
 330         ENTRY;
 331
 332         record_start_io(osd, READ, 0);
 333
 334         /* grab buffers for read:
 335          * OSD API let us to grab buffers first, then initiate IO(s)
 336          * so that all required IOs will be done in parallel, but at the
 337          * moment DMU doesn't provide us with a method to grab buffers.
 338          * If we discover this is a vital for good performance we
 339          * can get own replacement for dmu_buf_hold_array_by_bonus().
 340          */
 341         while (len > 0) {
 342                 rc = -dmu_buf_hold_array_by_bonus(obj->oo_db, off, len, TRUE,
 343                                                   osd_zerocopy_tag, &numbufs,
 344                                                   &dbp);
 345                 if (unlikely(rc))
 346                         GOTO(err, rc);
 347
 348                 for (i = 0; i < numbufs; i++) {
 349                         int bufoff, tocpy, thispage;
 350                         void *dbf = dbp[i];
 351
 352                         LASSERT(len > 0);
 353
 354                         atomic_inc(&osd->od_zerocopy_pin);
 355
 356                         bufoff = off - dbp[i]->db_offset;
 357                         tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
 358
 359                         /* kind of trick to differentiate dbuf vs. arcbuf */
 360                         LASSERT(((unsigned long)dbp[i] & 1) == 0);
 361                         dbf = (void *) ((unsigned long)dbp[i] | 1);
 362
 363                         while (tocpy > 0) {
 364                                 thispage = PAGE_CACHE_SIZE;
 365                                 thispage -= bufoff & (PAGE_CACHE_SIZE - 1);
 366                                 thispage = min(tocpy, thispage);
 367
 368                                 lnb->lnb_rc = 0;
 369                                 lnb->lnb_file_offset = off;
 370                                 lnb->lnb_page_offset = bufoff & ~PAGE_MASK;
 371                                 lnb->lnb_len = thispage;
 372                                 lnb->lnb_page = kmem_to_page(dbp[i]->db_data +
 373                                                              bufoff);
 374                                 /* mark just a single slot: we need this
 375                                  * reference to dbuf to be released once */
 376                                 lnb->lnb_data = dbf;
 377                                 dbf = NULL;
 378
 379                                 tocpy -= thispage;
 380                                 len -= thispage;
 381                                 bufoff += thispage;
 382                                 off += thispage;
 383
 384                                 npages++;
 385                                 lnb++;
 386                         }
 387
 388                         /* steal dbuf so dmu_buf_rele_array() can't release
 389                          * it */
 390                         dbp[i] = NULL;
 391                 }
 392
 393                 dmu_buf_rele_array(dbp, numbufs, osd_zerocopy_tag);
 394         }
 395
 396         record_end_io(osd, READ, cfs_time_current() - start,
 397                       npages * PAGE_SIZE, npages);
 398
 399         RETURN(npages);
 400
 401 err:
 402         LASSERT(rc < 0);
 403         osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
 404         RETURN(rc);
 405 }
 406
 407 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
 408                                 loff_t off, ssize_t len, struct niobuf_local *lnb)
 409 {
 410         struct osd_device *osd = osd_obj2dev(obj);
 411         int                plen, off_in_block, sz_in_block;
 412         int                rc, i = 0, npages = 0;
 413         arc_buf_t         *abuf;
 414         uint32_t           bs;
 415         uint64_t           dummy;
 416         ENTRY;
 417
 418         dmu_object_size_from_db(obj->oo_db, &bs, &dummy);
 419
 420         /*
 421          * currently only full blocks are subject to zerocopy approach:
 422          * so that we're sure nobody is trying to update the same block
 423          */
 424         while (len > 0) {
 425                 LASSERT(npages < PTLRPC_MAX_BRW_PAGES);
 426
 427                 off_in_block = off & (bs - 1);
 428                 sz_in_block = min_t(int, bs - off_in_block, len);
 429
 430                 if (sz_in_block == bs) {
 431                         /* full block, try to use zerocopy */
 432
 433                         abuf = dmu_request_arcbuf(obj->oo_db, bs);
 434                         if (unlikely(abuf == NULL))
 435                                 GOTO(out_err, rc = -ENOMEM);
 436
 437                         atomic_inc(&osd->od_zerocopy_loan);
 438
 439                         /* go over pages arcbuf contains, put them as
 440                          * local niobufs for ptlrpc's bulks */
 441                         while (sz_in_block > 0) {
 442                                 plen = min_t(int, sz_in_block, PAGE_CACHE_SIZE);
 443
 444                                 lnb[i].lnb_file_offset = off;
 445                                 lnb[i].lnb_page_offset = 0;
 446                                 lnb[i].lnb_len = plen;
 447                                 lnb[i].lnb_rc = 0;
 448                                 if (sz_in_block == bs)
 449                                         lnb[i].lnb_data = abuf;
 450                                 else
 451                                         lnb[i].lnb_data = NULL;
 452
 453                                 /* this one is not supposed to fail */
 454                                 lnb[i].lnb_page = kmem_to_page(abuf->b_data +
 455                                                         off_in_block);
 456                                 LASSERT(lnb[i].lnb_page);
 457
 458                                 lprocfs_counter_add(osd->od_stats,
 459                                                 LPROC_OSD_ZEROCOPY_IO, 1);
 460
 461                                 sz_in_block -= plen;
 462                                 len -= plen;
 463                                 off += plen;
 464                                 off_in_block += plen;
 465                                 i++;
 466                                 npages++;
 467                         }
 468                 } else {
 469                         if (off_in_block == 0 && len < bs &&
 470                                         off + len >= obj->oo_attr.la_size)
 471                                 lprocfs_counter_add(osd->od_stats,
 472                                                 LPROC_OSD_TAIL_IO, 1);
 473
 474                         /* can't use zerocopy, allocate temp. buffers */
 475                         while (sz_in_block > 0) {
 476                                 plen = min_t(int, sz_in_block, PAGE_CACHE_SIZE);
 477
 478                                 lnb[i].lnb_file_offset = off;
 479                                 lnb[i].lnb_page_offset = 0;
 480                                 lnb[i].lnb_len = plen;
 481                                 lnb[i].lnb_rc = 0;
 482                                 lnb[i].lnb_data = NULL;
 483
 484                                 lnb[i].lnb_page = alloc_page(OSD_GFP_IO);
 485                                 if (unlikely(lnb[i].lnb_page == NULL))
 486                                         GOTO(out_err, rc = -ENOMEM);
 487
 488                                 LASSERT(lnb[i].lnb_page->mapping == NULL);
 489                                 lnb[i].lnb_page->mapping = (void *)obj;
 490
 491                                 atomic_inc(&osd->od_zerocopy_alloc);
 492                                 lprocfs_counter_add(osd->od_stats,
 493                                                 LPROC_OSD_COPY_IO, 1);
 494
 495                                 sz_in_block -= plen;
 496                                 len -= plen;
 497                                 off += plen;
 498                                 i++;
 499                                 npages++;
 500                         }
 501                 }
 502         }
 503
 504         RETURN(npages);
 505
 506 out_err:
 507         osd_bufs_put(env, &obj->oo_dt, lnb, npages);
 508         RETURN(rc);
 509 }
 510
 511 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
 512                         loff_t offset, ssize_t len, struct niobuf_local *lnb,
 513                         int rw)
 514 {
 515         struct osd_object *obj  = osd_dt_obj(dt);
 516         int                rc;
 517
 518         LASSERT(dt_object_exists(dt));
 519         LASSERT(obj->oo_db);
 520
 521         if (rw == 0)
 522                 rc = osd_bufs_get_read(env, obj, offset, len, lnb);
 523         else
 524                 rc = osd_bufs_get_write(env, obj, offset, len, lnb);
 525
 526         return rc;
 527 }
 528
 529 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
 530                         struct niobuf_local *lnb, int npages)
 531 {
 532         struct osd_object *obj = osd_dt_obj(dt);
 533
 534         LASSERT(dt_object_exists(dt));
 535         LASSERT(obj->oo_db);
 536
 537         return 0;
 538 }
 539
 540 static inline uint32_t osd_get_blocksz(struct osd_object *obj)
 541 {
 542         uint32_t blksz;
 543         u_longlong_t unused;
 544
 545         LASSERT(obj->oo_db);
 546
 547         dmu_object_size_from_db(obj->oo_db, &blksz, &unused);
 548         return blksz;
 549 }
 550
 551 static inline uint64_t osd_roundup2blocksz(uint64_t size,
 552                                            uint64_t offset,
 553                                            uint32_t blksz)
 554 {
 555         LASSERT(blksz > 0);
 556
 557         size += offset % blksz;
 558
 559         if (likely(IS_PO2(blksz)))
 560                 return PO2_ROUNDUP_TYPED(size, blksz, uint64_t);
 561
 562         size += blksz - 1;
 563         do_div(size, blksz);
 564         return size * blksz;
 565 }
 566
 567 static int osd_declare_write_commit(const struct lu_env *env,
 568                                     struct dt_object *dt,
 569                                     struct niobuf_local *lnb, int npages,
 570                                     struct thandle *th)
 571 {
 572         struct osd_object  *obj = osd_dt_obj(dt);
 573         struct osd_device  *osd = osd_obj2dev(obj);
 574         struct osd_thandle *oh;
 575         uint64_t            offset = 0;
 576         uint32_t            size = 0;
 577         uint32_t            blksz = osd_get_blocksz(obj);
 578         int                 i, rc, flags = 0;
 579         bool                ignore_quota = false, synced = false;
 580         long long           space = 0;
 581         struct page        *last_page = NULL;
 582         unsigned long       discont_pages = 0;
 583         ENTRY;
 584
 585         LASSERT(dt_object_exists(dt));
 586         LASSERT(obj->oo_db);
 587
 588         LASSERT(lnb);
 589         LASSERT(npages > 0);
 590
 591         oh = container_of0(th, struct osd_thandle, ot_super);
 592
 593         for (i = 0; i < npages; i++) {
 594                 if (last_page && lnb[i].lnb_page->index != (last_page->index + 1))
 595                         ++discont_pages;
 596                 last_page = lnb[i].lnb_page;
 597                 if (lnb[i].lnb_rc)
 598                         /* ENOSPC, network RPC error, etc.
 599                          * We don't want to book space for pages which will be
 600                          * skipped in osd_write_commit(). Hence we skip pages
 601                          * with lnb_rc != 0 here too */
 602                         continue;
 603                 /* ignore quota for the whole request if any page is from
 604                  * client cache or written by root.
 605                  *
 606                  * XXX once we drop the 1.8 client support, the checking
 607                  * for whether page is from cache can be simplified as:
 608                  * !(lnb[i].flags & OBD_BRW_SYNC)
 609                  *
 610                  * XXX we could handle this on per-lnb basis as done by
 611                  * grant. */
 612                 if ((lnb[i].lnb_flags & OBD_BRW_NOQUOTA) ||
 613                     (lnb[i].lnb_flags & (OBD_BRW_FROM_GRANT | OBD_BRW_SYNC)) ==
 614                     OBD_BRW_FROM_GRANT)
 615                         ignore_quota = true;
 616                 if (size == 0) {
 617                         /* first valid lnb */
 618                         offset = lnb[i].lnb_file_offset;
 619                         size = lnb[i].lnb_len;
 620                         continue;
 621                 }
 622                 if (offset + size == lnb[i].lnb_file_offset) {
 623                         /* this lnb is contiguous to the previous one */
 624                         size += lnb[i].lnb_len;
 625                         continue;
 626                 }
 627
 628                 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object,
 629                                   offset, size);
 630                 /* Estimating space to be consumed by a write is rather
 631                  * complicated with ZFS. As a consequence, we don't account for
 632                  * indirect blocks and just use as a rough estimate the worse
 633                  * case where the old space is being held by a snapshot. Quota
 634                  * overrun will be adjusted once the operation is committed, if
 635                  * required. */
 636                 space += osd_roundup2blocksz(size, offset, blksz);
 637
 638                 offset = lnb[i].lnb_file_offset;
 639                 size = lnb[i].lnb_len;
 640         }
 641
 642         if (size) {
 643                 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object,
 644                                   offset, size);
 645                 space += osd_roundup2blocksz(size, offset, blksz);
 646         }
 647
 648         dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 649
 650         oh->ot_write_commit = 1; /* used in osd_trans_start() for fail_loc */
 651
 652         /* backend zfs filesystem might be configured to store multiple data
 653          * copies */
 654         space  *= osd->od_os->os_copies;
 655         space   = toqb(space);
 656         CDEBUG(D_QUOTA, "writing %d pages, reserving "LPD64"K of quota space\n",
 657                npages, space);
 658
 659         record_start_io(osd, WRITE, discont_pages);
 660 retry:
 661         /* acquire quota space if needed */
 662         rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 663                                obj->oo_attr.la_gid, space, oh, true, &flags,
 664                                ignore_quota);
 665
 666         if (!synced && rc == -EDQUOT && (flags & QUOTA_FL_SYNC) != 0) {
 667                 dt_sync(env, th->th_dev);
 668                 synced = true;
 669                 CDEBUG(D_QUOTA, "retry after sync\n");
 670                 flags = 0;
 671                 goto retry;
 672         }
 673
 674         /* we need only to store the overquota flags in the first lnb for
 675          * now, once we support multiple objects BRW, this code needs be
 676          * revised. */
 677         if (flags & QUOTA_FL_OVER_USRQUOTA)
 678                 lnb[0].lnb_flags |= OBD_BRW_OVER_USRQUOTA;
 679         if (flags & QUOTA_FL_OVER_GRPQUOTA)
 680                 lnb[0].lnb_flags |= OBD_BRW_OVER_GRPQUOTA;
 681
 682         RETURN(rc);
 683 }
 684
 685 /**
 686  * Policy to grow ZFS block size by write pattern.
 687  * For sequential write, it grows block size gradually until it reaches the
 688  * maximum blocksize the dataset can support. Otherwise, it will pick a
 689  * a block size by the writing region of this I/O.
 690  */
 691 static int osd_grow_blocksize(struct osd_object *obj, struct osd_thandle *oh,
 692                               uint64_t start, uint64_t end)
 693 {
 694         struct osd_device       *osd = osd_obj2dev(obj);
 695         dmu_buf_impl_t          *db = (dmu_buf_impl_t *)obj->oo_db;
 696         dnode_t                 *dn;
 697         uint32_t                 blksz;
 698         int                      rc = 0;
 699
 700         ENTRY;
 701
 702         DB_DNODE_ENTER(db);
 703         dn = DB_DNODE(db);
 704
 705         if (dn->dn_maxblkid > 0) /* can't change block size */
 706                 GOTO(out, rc);
 707
 708         if (dn->dn_datablksz >= osd->od_max_blksz)
 709                 GOTO(out, rc);
 710
 711         down_write(&obj->oo_guard);
 712
 713         blksz = dn->dn_datablksz;
 714         if (blksz >= osd->od_max_blksz) /* check again after grabbing lock */
 715                 GOTO(out_unlock, rc);
 716
 717         /* now ZFS can support up to 16MB block size, and if the write
 718          * is sequential, it just increases the block size gradually */
 719         if (start <= blksz) { /* sequential */
 720                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz, end);
 721         } else { /* sparse, pick a block size by write region */
 722                 blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz,
 723                                         end - start);
 724         }
 725
 726         if (!is_power_of_2(blksz))
 727                 blksz = size_roundup_power2(blksz);
 728
 729         if (blksz > dn->dn_datablksz) {
 730                 rc = -dmu_object_set_blocksize(osd->od_os, dn->dn_object,
 731                                                blksz, 0, oh->ot_tx);
 732                 LASSERT(ergo(rc == 0, dn->dn_datablksz >= blksz));
 733                 if (rc < 0)
 734                         CDEBUG(D_INODE, "object "DFID": change block size"
 735                                "%u -> %u error rc = %d\n",
 736                                PFID(lu_object_fid(&obj->oo_dt.do_lu)),
 737                                dn->dn_datablksz, blksz, rc);
 738         }
 739         EXIT;
 740 out_unlock:
 741         up_write(&obj->oo_guard);
 742 out:
 743         DB_DNODE_EXIT(db);
 744         return rc;
 745 }
 746
 747 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 748                         struct niobuf_local *lnb, int npages,
 749                         struct thandle *th)
 750 {
 751         struct osd_object  *obj  = osd_dt_obj(dt);
 752         struct osd_device  *osd = osd_obj2dev(obj);
 753         struct osd_thandle *oh;
 754         uint64_t            new_size = 0;
 755         int                 i, rc = 0;
 756         unsigned long      iosize = 0;
 757         ENTRY;
 758
 759         LASSERT(dt_object_exists(dt));
 760         LASSERT(obj->oo_db);
 761
 762         LASSERT(th != NULL);
 763         oh = container_of0(th, struct osd_thandle, ot_super);
 764
 765         /* adjust block size. Assume the buffers are sorted. */
 766         (void)osd_grow_blocksize(obj, oh, lnb[0].lnb_file_offset,
 767                                  lnb[npages - 1].lnb_file_offset +
 768                                  lnb[npages - 1].lnb_len);
 769         for (i = 0; i < npages; i++) {
 770                 CDEBUG(D_INODE, "write %u bytes at %u\n",
 771                         (unsigned) lnb[i].lnb_len,
 772                         (unsigned) lnb[i].lnb_file_offset);
 773
 774                 if (lnb[i].lnb_rc) {
 775                         /* ENOSPC, network RPC error, etc.
 776                          * Unlike ldiskfs, zfs allocates new blocks on rewrite,
 777                          * so we skip this page if lnb_rc is set to -ENOSPC */
 778                         CDEBUG(D_INODE, "obj "DFID": skipping lnb[%u]: rc=%d\n",
 779                                 PFID(lu_object_fid(&dt->do_lu)), i,
 780                                 lnb[i].lnb_rc);
 781                         continue;
 782                 }
 783
 784                 if (lnb[i].lnb_page->mapping == (void *)obj) {
 785                         dmu_write(osd->od_os, obj->oo_db->db_object,
 786                                 lnb[i].lnb_file_offset, lnb[i].lnb_len,
 787                                 kmap(lnb[i].lnb_page), oh->ot_tx);
 788                         kunmap(lnb[i].lnb_page);
 789                 } else if (lnb[i].lnb_data) {
 790                         LASSERT(((unsigned long)lnb[i].lnb_data & 1) == 0);
 791                         /* buffer loaned for zerocopy, try to use it.
 792                          * notice that dmu_assign_arcbuf() is smart
 793                          * enough to recognize changed blocksize
 794                          * in this case it fallbacks to dmu_write() */
 795                         dmu_assign_arcbuf(obj->oo_db, lnb[i].lnb_file_offset,
 796                                           lnb[i].lnb_data, oh->ot_tx);
 797                         /* drop the reference, otherwise osd_put_bufs()
 798                          * will be releasing it - bad! */
 799                         lnb[i].lnb_data = NULL;
 800                         atomic_dec(&osd->od_zerocopy_loan);
 801                 }
 802
 803                 if (new_size < lnb[i].lnb_file_offset + lnb[i].lnb_len)
 804                         new_size = lnb[i].lnb_file_offset + lnb[i].lnb_len;
 805                 iosize += lnb[i].lnb_len;
 806         }
 807
 808         if (unlikely(new_size == 0)) {
 809                 /* no pages to write, no transno is needed */
 810                 th->th_local = 1;
 811                 /* it is important to return 0 even when all lnb_rc == -ENOSPC
 812                  * since ofd_commitrw_write() retries several times on ENOSPC */
 813                 record_end_io(osd, WRITE, 0, 0, 0);
 814                 RETURN(0);
 815         }
 816
 817         write_lock(&obj->oo_attr_lock);
 818         if (obj->oo_attr.la_size < new_size) {
 819                 obj->oo_attr.la_size = new_size;
 820                 write_unlock(&obj->oo_attr_lock);
 821                 /* osd_object_sa_update() will be copying directly from
 822                  * oo_attr into dbuf. any update within a single txg will copy
 823                  * the most actual */
 824                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 825                                           &obj->oo_attr.la_size, 8, oh);
 826         } else {
 827                 write_unlock(&obj->oo_attr_lock);
 828         }
 829
 830         record_end_io(osd, WRITE, 0, iosize, npages);
 831
 832         RETURN(rc);
 833 }
 834
 835 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 836                         struct niobuf_local *lnb, int npages)
 837 {
 838         struct osd_object *obj  = osd_dt_obj(dt);
 839         int                i;
 840         loff_t             eof;
 841
 842         LASSERT(dt_object_exists(dt));
 843         LASSERT(obj->oo_db);
 844
 845         read_lock(&obj->oo_attr_lock);
 846         eof = obj->oo_attr.la_size;
 847         read_unlock(&obj->oo_attr_lock);
 848
 849         for (i = 0; i < npages; i++) {
 850                 if (unlikely(lnb[i].lnb_rc < 0))
 851                         continue;
 852
 853                 lnb[i].lnb_rc = lnb[i].lnb_len;
 854
 855                 if (lnb[i].lnb_file_offset + lnb[i].lnb_len >= eof) {
 856                         if (eof <= lnb[i].lnb_file_offset)
 857                                 lnb[i].lnb_rc = 0;
 858                         else
 859                                 lnb[i].lnb_rc = eof - lnb[i].lnb_file_offset;
 860
 861                         /* all subsequent rc should be 0 */
 862                         while (++i < npages)
 863                                 lnb[i].lnb_rc = 0;
 864                         break;
 865                 }
 866         }
 867
 868         return 0;
 869 }
 870
 871 /*
 872  * Punch/truncate an object
 873  *
 874  *      IN:     db  - dmu_buf of the object to free data in.
 875  *              off - start of section to free.
 876  *              len - length of section to free (DMU_OBJECT_END => to EOF).
 877  *
 878  *      RETURN: 0 if success
 879  *              error code if failure
 880  *
 881  * The transaction passed to this routine must have
 882  * dmu_tx_hold_sa() and if off < size, dmu_tx_hold_free()
 883  * called and then assigned to a transaction group.
 884  */
 885 static int __osd_object_punch(objset_t *os, dmu_buf_t *db, dmu_tx_t *tx,
 886                                 uint64_t size, uint64_t off, uint64_t len)
 887 {
 888         int rc = 0;
 889
 890         /* Assert that the transaction has been assigned to a
 891            transaction group. */
 892         LASSERT(tx->tx_txg != 0);
 893         /*
 894          * Nothing to do if file already at desired length.
 895          */
 896         if (len == DMU_OBJECT_END && size == off)
 897                 return 0;
 898
 899         if (off < size)
 900                 rc = -dmu_free_range(os, db->db_object, off, len, tx);
 901
 902         return rc;
 903 }
 904
 905 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
 906                         __u64 start, __u64 end, struct thandle *th)
 907 {
 908         struct osd_object  *obj = osd_dt_obj(dt);
 909         struct osd_device  *osd = osd_obj2dev(obj);
 910         struct osd_thandle *oh;
 911         __u64               len;
 912         int                 rc = 0;
 913         ENTRY;
 914
 915         LASSERT(dt_object_exists(dt));
 916         LASSERT(osd_invariant(obj));
 917
 918         LASSERT(th != NULL);
 919         oh = container_of0(th, struct osd_thandle, ot_super);
 920
 921         write_lock(&obj->oo_attr_lock);
 922         /* truncate */
 923         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
 924                 len = DMU_OBJECT_END;
 925         else
 926                 len = end - start;
 927         write_unlock(&obj->oo_attr_lock);
 928
 929         rc = __osd_object_punch(osd->od_os, obj->oo_db, oh->ot_tx,
 930                                 obj->oo_attr.la_size, start, len);
 931         /* set new size */
 932         if (len == DMU_OBJECT_END) {
 933                 write_lock(&obj->oo_attr_lock);
 934                 obj->oo_attr.la_size = start;
 935                 write_unlock(&obj->oo_attr_lock);
 936                 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(osd),
 937                                           &obj->oo_attr.la_size, 8, oh);
 938         }
 939         RETURN(rc);
 940 }
 941
 942 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
 943                         __u64 start, __u64 end, struct thandle *handle)
 944 {
 945         struct osd_object  *obj = osd_dt_obj(dt);
 946         struct osd_device  *osd = osd_obj2dev(obj);
 947         struct osd_thandle *oh;
 948         __u64               len;
 949         ENTRY;
 950
 951         oh = container_of0(handle, struct osd_thandle, ot_super);
 952
 953         read_lock(&obj->oo_attr_lock);
 954         if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
 955                 len = DMU_OBJECT_END;
 956         else
 957                 len = end - start;
 958
 959         /* declare we'll free some blocks ... */
 960         if (start < obj->oo_attr.la_size) {
 961                 read_unlock(&obj->oo_attr_lock);
 962                 dmu_tx_hold_free(oh->ot_tx, obj->oo_db->db_object, start, len);
 963         } else {
 964                 read_unlock(&obj->oo_attr_lock);
 965         }
 966
 967         /* ... and we'll modify size attribute */
 968         dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
 969
 970         RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
 971                                  obj->oo_attr.la_gid, 0, oh, true, NULL,
 972                                  false));
 973 }
 974
 975 static int osd_ladvise(const struct lu_env *env, struct dt_object *dt,
 976                        __u64 start, __u64 end, enum lu_ladvise_type advice)
 977 {
 978         int     rc;
 979         ENTRY;
 980
 981         switch (advice) {
 982         default:
 983                 rc = -ENOTSUPP;
 984                 break;
 985         }
 986
 987         RETURN(rc);
 988 }
 989
 990 struct dt_body_operations osd_body_ops = {
 991         .dbo_read                       = osd_read,
 992         .dbo_declare_write              = osd_declare_write,
 993         .dbo_write                      = osd_write,
 994         .dbo_bufs_get                   = osd_bufs_get,
 995         .dbo_bufs_put                   = osd_bufs_put,
 996         .dbo_write_prep                 = osd_write_prep,
 997         .dbo_declare_write_commit       = osd_declare_write_commit,
 998         .dbo_write_commit               = osd_write_commit,
 999         .dbo_read_prep                  = osd_read_prep,
1000         .dbo_declare_punch              = osd_declare_punch,
1001         .dbo_punch                      = osd_punch,
1002         .dbo_ladvise                    = osd_ladvise,
1003 };