fs/nfs/flexfilelayout/flexfilelayout.c

   1 /*
   2  * Module for pnfs flexfile layout driver.
   3  *
   4  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
   5  *
   6  * Tao Peng <bergwolf@primarydata.com>
   7  */
   8
   9 #include <linux/nfs_fs.h>
  10 #include <linux/nfs_page.h>
  11 #include <linux/module.h>
  12
  13 #include <linux/sunrpc/metrics.h>
  14
  15 #include "flexfilelayout.h"
  16 #include "../nfs4session.h"
  17 #include "../nfs4idmap.h"
  18 #include "../internal.h"
  19 #include "../delegation.h"
  20 #include "../nfs4trace.h"
  21 #include "../iostat.h"
  22 #include "../nfs.h"
  23 #include "../nfs42.h"
  24
  25 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  26
  27 #define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)
  28
  29 static struct pnfs_layout_hdr *
  30 ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
  31 {
  32         struct nfs4_flexfile_layout *ffl;
  33
  34         ffl = kzalloc(sizeof(*ffl), gfp_flags);
  35         if (ffl) {
  36                 INIT_LIST_HEAD(&ffl->error_list);
  37                 INIT_LIST_HEAD(&ffl->mirrors);
  38                 return &ffl->generic_hdr;
  39         } else
  40                 return NULL;
  41 }
  42
  43 static void
  44 ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
  45 {
  46         struct nfs4_ff_layout_ds_err *err, *n;
  47
  48         list_for_each_entry_safe(err, n, &FF_LAYOUT_FROM_HDR(lo)->error_list,
  49                                  list) {
  50                 list_del(&err->list);
  51                 kfree(err);
  52         }
  53         kfree(FF_LAYOUT_FROM_HDR(lo));
  54 }
  55
  56 static int decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
  57 {
  58         __be32 *p;
  59
  60         p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
  61         if (unlikely(p == NULL))
  62                 return -ENOBUFS;
  63         memcpy(stateid, p, NFS4_STATEID_SIZE);
  64         dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
  65                 p[0], p[1], p[2], p[3]);
  66         return 0;
  67 }
  68
  69 static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
  70 {
  71         __be32 *p;
  72
  73         p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
  74         if (unlikely(!p))
  75                 return -ENOBUFS;
  76         memcpy(devid, p, NFS4_DEVICEID4_SIZE);
  77         nfs4_print_deviceid(devid);
  78         return 0;
  79 }
  80
  81 static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  82 {
  83         __be32 *p;
  84
  85         p = xdr_inline_decode(xdr, 4);
  86         if (unlikely(!p))
  87                 return -ENOBUFS;
  88         fh->size = be32_to_cpup(p++);
  89         if (fh->size > sizeof(struct nfs_fh)) {
  90                 printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
  91                        fh->size);
  92                 return -EOVERFLOW;
  93         }
  94         /* fh.data */
  95         p = xdr_inline_decode(xdr, fh->size);
  96         if (unlikely(!p))
  97                 return -ENOBUFS;
  98         memcpy(&fh->data, p, fh->size);
  99         dprintk("%s: fh len %d\n", __func__, fh->size);
 100
 101         return 0;
 102 }
 103
 104 /*
 105  * Currently only stringified uids and gids are accepted.
 106  * I.e., kerberos is not supported to the DSes, so no pricipals.
 107  *
 108  * That means that one common function will suffice, but when
 109  * principals are added, this should be split to accomodate
 110  * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
 111  */
 112 static int
 113 decode_name(struct xdr_stream *xdr, u32 *id)
 114 {
 115         __be32 *p;
 116         int len;
 117
 118         /* opaque_length(4)*/
 119         p = xdr_inline_decode(xdr, 4);
 120         if (unlikely(!p))
 121                 return -ENOBUFS;
 122         len = be32_to_cpup(p++);
 123         if (len < 0)
 124                 return -EINVAL;
 125
 126         dprintk("%s: len %u\n", __func__, len);
 127
 128         /* opaque body */
 129         p = xdr_inline_decode(xdr, len);
 130         if (unlikely(!p))
 131                 return -ENOBUFS;
 132
 133         if (!nfs_map_string_to_numeric((char *)p, len, id))
 134                 return -EINVAL;
 135
 136         return 0;
 137 }
 138
 139 static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
 140                 const struct nfs4_ff_layout_mirror *m2)
 141 {
 142         int i, j;
 143
 144         if (m1->fh_versions_cnt != m2->fh_versions_cnt)
 145                 return false;
 146         for (i = 0; i < m1->fh_versions_cnt; i++) {
 147                 bool found_fh = false;
 148                 for (j = 0; j < m2->fh_versions_cnt; i++) {
 149                         if (nfs_compare_fh(&m1->fh_versions[i],
 150                                         &m2->fh_versions[j]) == 0) {
 151                                 found_fh = true;
 152                                 break;
 153                         }
 154                 }
 155                 if (!found_fh)
 156                         return false;
 157         }
 158         return true;
 159 }
 160
 161 static struct nfs4_ff_layout_mirror *
 162 ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
 163                 struct nfs4_ff_layout_mirror *mirror)
 164 {
 165         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
 166         struct nfs4_ff_layout_mirror *pos;
 167         struct inode *inode = lo->plh_inode;
 168
 169         spin_lock(&inode->i_lock);
 170         list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
 171                 if (mirror->mirror_ds != pos->mirror_ds)
 172                         continue;
 173                 if (!ff_mirror_match_fh(mirror, pos))
 174                         continue;
 175                 if (atomic_inc_not_zero(&pos->ref)) {
 176                         spin_unlock(&inode->i_lock);
 177                         return pos;
 178                 }
 179         }
 180         list_add(&mirror->mirrors, &ff_layout->mirrors);
 181         mirror->layout = lo;
 182         spin_unlock(&inode->i_lock);
 183         return mirror;
 184 }
 185
 186 static void
 187 ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
 188 {
 189         struct inode *inode;
 190         if (mirror->layout == NULL)
 191                 return;
 192         inode = mirror->layout->plh_inode;
 193         spin_lock(&inode->i_lock);
 194         list_del(&mirror->mirrors);
 195         spin_unlock(&inode->i_lock);
 196         mirror->layout = NULL;
 197 }
 198
 199 static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
 200 {
 201         struct nfs4_ff_layout_mirror *mirror;
 202
 203         mirror = kzalloc(sizeof(*mirror), gfp_flags);
 204         if (mirror != NULL) {
 205                 spin_lock_init(&mirror->lock);
 206                 atomic_set(&mirror->ref, 1);
 207                 INIT_LIST_HEAD(&mirror->mirrors);
 208         }
 209         return mirror;
 210 }
 211
 212 static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
 213 {
 214         ff_layout_remove_mirror(mirror);
 215         kfree(mirror->fh_versions);
 216         if (mirror->cred)
 217                 put_rpccred(mirror->cred);
 218         nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
 219         kfree(mirror);
 220 }
 221
 222 static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
 223 {
 224         if (mirror != NULL && atomic_dec_and_test(&mirror->ref))
 225                 ff_layout_free_mirror(mirror);
 226 }
 227
 228 static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
 229 {
 230         int i;
 231
 232         if (fls->mirror_array) {
 233                 for (i = 0; i < fls->mirror_array_cnt; i++) {
 234                         /* normally mirror_ds is freed in
 235                          * .free_deviceid_node but we still do it here
 236                          * for .alloc_lseg error path */
 237                         ff_layout_put_mirror(fls->mirror_array[i]);
 238                 }
 239                 kfree(fls->mirror_array);
 240                 fls->mirror_array = NULL;
 241         }
 242 }
 243
 244 static int ff_layout_check_layout(struct nfs4_layoutget_res *lgr)
 245 {
 246         int ret = 0;
 247
 248         dprintk("--> %s\n", __func__);
 249
 250         /* FIXME: remove this check when layout segment support is added */
 251         if (lgr->range.offset != 0 ||
 252             lgr->range.length != NFS4_MAX_UINT64) {
 253                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 254                         __func__);
 255                 ret = -EINVAL;
 256         }
 257
 258         dprintk("--> %s returns %d\n", __func__, ret);
 259         return ret;
 260 }
 261
 262 static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
 263 {
 264         if (fls) {
 265                 ff_layout_free_mirror_array(fls);
 266                 kfree(fls);
 267         }
 268 }
 269
 270 static bool
 271 ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
 272                 const struct pnfs_layout_range *l2)
 273 {
 274         u64 end1, end2;
 275
 276         if (l1->iomode != l2->iomode)
 277                 return l1->iomode != IOMODE_READ;
 278         end1 = pnfs_calc_offset_end(l1->offset, l1->length);
 279         end2 = pnfs_calc_offset_end(l2->offset, l2->length);
 280         if (end1 < l2->offset)
 281                 return false;
 282         if (end2 < l1->offset)
 283                 return true;
 284         return l2->offset <= l1->offset;
 285 }
 286
 287 static bool
 288 ff_lseg_merge(struct pnfs_layout_segment *new,
 289                 struct pnfs_layout_segment *old)
 290 {
 291         u64 new_end, old_end;
 292
 293         if (new->pls_range.iomode != old->pls_range.iomode)
 294                 return false;
 295         old_end = pnfs_calc_offset_end(old->pls_range.offset,
 296                         old->pls_range.length);
 297         if (old_end < new->pls_range.offset)
 298                 return false;
 299         new_end = pnfs_calc_offset_end(new->pls_range.offset,
 300                         new->pls_range.length);
 301         if (new_end < old->pls_range.offset)
 302                 return false;
 303
 304         /* Mergeable: copy info from 'old' to 'new' */
 305         if (new_end < old_end)
 306                 new_end = old_end;
 307         if (new->pls_range.offset < old->pls_range.offset)
 308                 new->pls_range.offset = old->pls_range.offset;
 309         new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
 310                         new_end);
 311         if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
 312                 set_bit(NFS_LSEG_ROC, &new->pls_flags);
 313         if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
 314                 set_bit(NFS_LSEG_LAYOUTRETURN, &new->pls_flags);
 315         return true;
 316 }
 317
 318 static void
 319 ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
 320                 struct pnfs_layout_segment *lseg,
 321                 struct list_head *free_me)
 322 {
 323         pnfs_generic_layout_insert_lseg(lo, lseg,
 324                         ff_lseg_range_is_after,
 325                         ff_lseg_merge,
 326                         free_me);
 327 }
 328
 329 static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
 330 {
 331         int i, j;
 332
 333         for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
 334                 for (j = i + 1; j < fls->mirror_array_cnt; j++)
 335                         if (fls->mirror_array[i]->efficiency <
 336                             fls->mirror_array[j]->efficiency)
 337                                 swap(fls->mirror_array[i],
 338                                      fls->mirror_array[j]);
 339         }
 340 }
 341
 342 static struct pnfs_layout_segment *
 343 ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 344                      struct nfs4_layoutget_res *lgr,
 345                      gfp_t gfp_flags)
 346 {
 347         struct pnfs_layout_segment *ret;
 348         struct nfs4_ff_layout_segment *fls = NULL;
 349         struct xdr_stream stream;
 350         struct xdr_buf buf;
 351         struct page *scratch;
 352         u64 stripe_unit;
 353         u32 mirror_array_cnt;
 354         __be32 *p;
 355         int i, rc;
 356
 357         dprintk("--> %s\n", __func__);
 358         scratch = alloc_page(gfp_flags);
 359         if (!scratch)
 360                 return ERR_PTR(-ENOMEM);
 361
 362         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
 363                               lgr->layoutp->len);
 364         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 365
 366         /* stripe unit and mirror_array_cnt */
 367         rc = -EIO;
 368         p = xdr_inline_decode(&stream, 8 + 4);
 369         if (!p)
 370                 goto out_err_free;
 371
 372         p = xdr_decode_hyper(p, &stripe_unit);
 373         mirror_array_cnt = be32_to_cpup(p++);
 374         dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
 375                 stripe_unit, mirror_array_cnt);
 376
 377         if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
 378             mirror_array_cnt == 0)
 379                 goto out_err_free;
 380
 381         rc = -ENOMEM;
 382         fls = kzalloc(sizeof(*fls), gfp_flags);
 383         if (!fls)
 384                 goto out_err_free;
 385
 386         fls->mirror_array_cnt = mirror_array_cnt;
 387         fls->stripe_unit = stripe_unit;
 388         fls->mirror_array = kcalloc(fls->mirror_array_cnt,
 389                                     sizeof(fls->mirror_array[0]), gfp_flags);
 390         if (fls->mirror_array == NULL)
 391                 goto out_err_free;
 392
 393         for (i = 0; i < fls->mirror_array_cnt; i++) {
 394                 struct nfs4_ff_layout_mirror *mirror;
 395                 struct nfs4_deviceid devid;
 396                 struct nfs4_deviceid_node *idnode;
 397                 u32 ds_count;
 398                 u32 fh_count;
 399                 int j;
 400
 401                 rc = -EIO;
 402                 p = xdr_inline_decode(&stream, 4);
 403                 if (!p)
 404                         goto out_err_free;
 405                 ds_count = be32_to_cpup(p);
 406
 407                 /* FIXME: allow for striping? */
 408                 if (ds_count != 1)
 409                         goto out_err_free;
 410
 411                 fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
 412                 if (fls->mirror_array[i] == NULL) {
 413                         rc = -ENOMEM;
 414                         goto out_err_free;
 415                 }
 416
 417                 fls->mirror_array[i]->ds_count = ds_count;
 418
 419                 /* deviceid */
 420                 rc = decode_deviceid(&stream, &devid);
 421                 if (rc)
 422                         goto out_err_free;
 423
 424                 idnode = nfs4_find_get_deviceid(NFS_SERVER(lh->plh_inode),
 425                                                 &devid, lh->plh_lc_cred,
 426                                                 gfp_flags);
 427                 /*
 428                  * upon success, mirror_ds is allocated by previous
 429                  * getdeviceinfo, or newly by .alloc_deviceid_node
 430                  * nfs4_find_get_deviceid failure is indeed getdeviceinfo falure
 431                  */
 432                 if (idnode)
 433                         fls->mirror_array[i]->mirror_ds =
 434                                 FF_LAYOUT_MIRROR_DS(idnode);
 435                 else
 436                         goto out_err_free;
 437
 438                 /* efficiency */
 439                 rc = -EIO;
 440                 p = xdr_inline_decode(&stream, 4);
 441                 if (!p)
 442                         goto out_err_free;
 443                 fls->mirror_array[i]->efficiency = be32_to_cpup(p);
 444
 445                 /* stateid */
 446                 rc = decode_stateid(&stream, &fls->mirror_array[i]->stateid);
 447                 if (rc)
 448                         goto out_err_free;
 449
 450                 /* fh */
 451                 p = xdr_inline_decode(&stream, 4);
 452                 if (!p)
 453                         goto out_err_free;
 454                 fh_count = be32_to_cpup(p);
 455
 456                 fls->mirror_array[i]->fh_versions =
 457                         kzalloc(fh_count * sizeof(struct nfs_fh),
 458                                 gfp_flags);
 459                 if (fls->mirror_array[i]->fh_versions == NULL) {
 460                         rc = -ENOMEM;
 461                         goto out_err_free;
 462                 }
 463
 464                 for (j = 0; j < fh_count; j++) {
 465                         rc = decode_nfs_fh(&stream,
 466                                            &fls->mirror_array[i]->fh_versions[j]);
 467                         if (rc)
 468                                 goto out_err_free;
 469                 }
 470
 471                 fls->mirror_array[i]->fh_versions_cnt = fh_count;
 472
 473                 /* user */
 474                 rc = decode_name(&stream, &fls->mirror_array[i]->uid);
 475                 if (rc)
 476                         goto out_err_free;
 477
 478                 /* group */
 479                 rc = decode_name(&stream, &fls->mirror_array[i]->gid);
 480                 if (rc)
 481                         goto out_err_free;
 482
 483                 mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
 484                 if (mirror != fls->mirror_array[i]) {
 485                         ff_layout_free_mirror(fls->mirror_array[i]);
 486                         fls->mirror_array[i] = mirror;
 487                 }
 488
 489                 dprintk("%s: uid %d gid %d\n", __func__,
 490                         fls->mirror_array[i]->uid,
 491                         fls->mirror_array[i]->gid);
 492         }
 493
 494         p = xdr_inline_decode(&stream, 4);
 495         if (p)
 496                 fls->flags = be32_to_cpup(p);
 497
 498         ff_layout_sort_mirrors(fls);
 499         rc = ff_layout_check_layout(lgr);
 500         if (rc)
 501                 goto out_err_free;
 502
 503         ret = &fls->generic_hdr;
 504         dprintk("<-- %s (success)\n", __func__);
 505 out_free_page:
 506         __free_page(scratch);
 507         return ret;
 508 out_err_free:
 509         _ff_layout_free_lseg(fls);
 510         ret = ERR_PTR(rc);
 511         dprintk("<-- %s (%d)\n", __func__, rc);
 512         goto out_free_page;
 513 }
 514
 515 static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
 516 {
 517         struct pnfs_layout_segment *lseg;
 518
 519         list_for_each_entry(lseg, &layout->plh_segs, pls_list)
 520                 if (lseg->pls_range.iomode == IOMODE_RW)
 521                         return true;
 522
 523         return false;
 524 }
 525
 526 static void
 527 ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
 528 {
 529         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 530
 531         dprintk("--> %s\n", __func__);
 532
 533         if (lseg->pls_range.iomode == IOMODE_RW) {
 534                 struct nfs4_flexfile_layout *ffl;
 535                 struct inode *inode;
 536
 537                 ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
 538                 inode = ffl->generic_hdr.plh_inode;
 539                 spin_lock(&inode->i_lock);
 540                 if (!ff_layout_has_rw_segments(lseg->pls_layout)) {
 541                         ffl->commit_info.nbuckets = 0;
 542                         kfree(ffl->commit_info.buckets);
 543                         ffl->commit_info.buckets = NULL;
 544                 }
 545                 spin_unlock(&inode->i_lock);
 546         }
 547         _ff_layout_free_lseg(fls);
 548 }
 549
 550 /* Return 1 until we have multiple lsegs support */
 551 static int
 552 ff_layout_get_lseg_count(struct nfs4_ff_layout_segment *fls)
 553 {
 554         return 1;
 555 }
 556
 557 static void
 558 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 559 {
 560         /* first IO request? */
 561         if (atomic_inc_return(&timer->n_ops) == 1) {
 562                 timer->start_time = now;
 563         }
 564 }
 565
 566 static ktime_t
 567 nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 568 {
 569         ktime_t start;
 570
 571         if (atomic_dec_return(&timer->n_ops) < 0)
 572                 WARN_ON_ONCE(1);
 573
 574         start = timer->start_time;
 575         timer->start_time = now;
 576         return ktime_sub(now, start);
 577 }
 578
 579 static bool
 580 nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
 581                             struct nfs4_ff_layoutstat *layoutstat,
 582                             ktime_t now)
 583 {
 584         static const ktime_t notime = {0};
 585         s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
 586
 587         nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
 588         if (ktime_equal(mirror->start_time, notime))
 589                 mirror->start_time = now;
 590         if (ktime_equal(mirror->last_report_time, notime))
 591                 mirror->last_report_time = now;
 592         if (layoutstats_timer != 0)
 593                 report_interval = (s64)layoutstats_timer * 1000LL;
 594         if (ktime_to_ms(ktime_sub(now, mirror->last_report_time)) >=
 595                         report_interval) {
 596                 mirror->last_report_time = now;
 597                 return true;
 598         }
 599
 600         return false;
 601 }
 602
 603 static void
 604 nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
 605                 __u64 requested)
 606 {
 607         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 608
 609         iostat->ops_requested++;
 610         iostat->bytes_requested += requested;
 611 }
 612
 613 static void
 614 nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
 615                 __u64 requested,
 616                 __u64 completed,
 617                 ktime_t time_completed,
 618                 ktime_t time_started)
 619 {
 620         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 621         ktime_t completion_time = ktime_sub(time_completed, time_started);
 622         ktime_t timer;
 623
 624         iostat->ops_completed++;
 625         iostat->bytes_completed += completed;
 626         iostat->bytes_not_delivered += requested - completed;
 627
 628         timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
 629         iostat->total_busy_time =
 630                         ktime_add(iostat->total_busy_time, timer);
 631         iostat->aggregate_completion_time =
 632                         ktime_add(iostat->aggregate_completion_time,
 633                                         completion_time);
 634 }
 635
 636 static void
 637 nfs4_ff_layout_stat_io_start_read(struct inode *inode,
 638                 struct nfs4_ff_layout_mirror *mirror,
 639                 __u64 requested, ktime_t now)
 640 {
 641         bool report;
 642
 643         spin_lock(&mirror->lock);
 644         report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
 645         nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
 646         spin_unlock(&mirror->lock);
 647
 648         if (report)
 649                 pnfs_report_layoutstat(inode, GFP_KERNEL);
 650 }
 651
 652 static void
 653 nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
 654                 struct nfs4_ff_layout_mirror *mirror,
 655                 __u64 requested,
 656                 __u64 completed)
 657 {
 658         spin_lock(&mirror->lock);
 659         nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
 660                         requested, completed,
 661                         ktime_get(), task->tk_start);
 662         spin_unlock(&mirror->lock);
 663 }
 664
 665 static void
 666 nfs4_ff_layout_stat_io_start_write(struct inode *inode,
 667                 struct nfs4_ff_layout_mirror *mirror,
 668                 __u64 requested, ktime_t now)
 669 {
 670         bool report;
 671
 672         spin_lock(&mirror->lock);
 673         report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
 674         nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
 675         spin_unlock(&mirror->lock);
 676
 677         if (report)
 678                 pnfs_report_layoutstat(inode, GFP_NOIO);
 679 }
 680
 681 static void
 682 nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
 683                 struct nfs4_ff_layout_mirror *mirror,
 684                 __u64 requested,
 685                 __u64 completed,
 686                 enum nfs3_stable_how committed)
 687 {
 688         if (committed == NFS_UNSTABLE)
 689                 requested = completed = 0;
 690
 691         spin_lock(&mirror->lock);
 692         nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
 693                         requested, completed, ktime_get(), task->tk_start);
 694         spin_unlock(&mirror->lock);
 695 }
 696
 697 static int
 698 ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 699                             struct nfs_commit_info *cinfo,
 700                             gfp_t gfp_flags)
 701 {
 702         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 703         struct pnfs_commit_bucket *buckets;
 704         int size;
 705
 706         if (cinfo->ds->nbuckets != 0) {
 707                 /* This assumes there is only one RW lseg per file.
 708                  * To support multiple lseg per file, we need to
 709                  * change struct pnfs_commit_bucket to allow dynamic
 710                  * increasing nbuckets.
 711                  */
 712                 return 0;
 713         }
 714
 715         size = ff_layout_get_lseg_count(fls) * FF_LAYOUT_MIRROR_COUNT(lseg);
 716
 717         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 718                           gfp_flags);
 719         if (!buckets)
 720                 return -ENOMEM;
 721         else {
 722                 int i;
 723
 724                 spin_lock(cinfo->lock);
 725                 if (cinfo->ds->nbuckets != 0)
 726                         kfree(buckets);
 727                 else {
 728                         cinfo->ds->buckets = buckets;
 729                         cinfo->ds->nbuckets = size;
 730                         for (i = 0; i < size; i++) {
 731                                 INIT_LIST_HEAD(&buckets[i].written);
 732                                 INIT_LIST_HEAD(&buckets[i].committing);
 733                                 /* mark direct verifier as unset */
 734                                 buckets[i].direct_verf.committed =
 735                                         NFS_INVALID_STABLE_HOW;
 736                         }
 737                 }
 738                 spin_unlock(cinfo->lock);
 739                 return 0;
 740         }
 741 }
 742
 743 static struct nfs4_pnfs_ds *
 744 ff_layout_choose_best_ds_for_read(struct nfs_pageio_descriptor *pgio,
 745                                   int *best_idx)
 746 {
 747         struct nfs4_ff_layout_segment *fls;
 748         struct nfs4_pnfs_ds *ds;
 749         int idx;
 750
 751         fls = FF_LAYOUT_LSEG(pgio->pg_lseg);
 752         /* mirrors are sorted by efficiency */
 753         for (idx = 0; idx < fls->mirror_array_cnt; idx++) {
 754                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, idx, false);
 755                 if (ds) {
 756                         *best_idx = idx;
 757                         return ds;
 758                 }
 759         }
 760
 761         return NULL;
 762 }
 763
 764 static void
 765 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 766                         struct nfs_page *req)
 767 {
 768         struct nfs_pgio_mirror *pgm;
 769         struct nfs4_ff_layout_mirror *mirror;
 770         struct nfs4_pnfs_ds *ds;
 771         int ds_idx;
 772
 773         /* Use full layout for now */
 774         if (!pgio->pg_lseg)
 775                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 776                                                    req->wb_context,
 777                                                    0,
 778                                                    NFS4_MAX_UINT64,
 779                                                    IOMODE_READ,
 780                                                    GFP_KERNEL);
 781         /* If no lseg, fall back to read through mds */
 782         if (pgio->pg_lseg == NULL)
 783                 goto out_mds;
 784
 785         ds = ff_layout_choose_best_ds_for_read(pgio, &ds_idx);
 786         if (!ds)
 787                 goto out_mds;
 788         mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 789
 790         pgio->pg_mirror_idx = ds_idx;
 791
 792         /* read always uses only one mirror - idx 0 for pgio layer */
 793         pgm = &pgio->pg_mirrors[0];
 794         pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 795
 796         return;
 797 out_mds:
 798         pnfs_put_lseg(pgio->pg_lseg);
 799         pgio->pg_lseg = NULL;
 800         nfs_pageio_reset_read_mds(pgio);
 801 }
 802
 803 static void
 804 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 805                         struct nfs_page *req)
 806 {
 807         struct nfs4_ff_layout_mirror *mirror;
 808         struct nfs_pgio_mirror *pgm;
 809         struct nfs_commit_info cinfo;
 810         struct nfs4_pnfs_ds *ds;
 811         int i;
 812         int status;
 813
 814         if (!pgio->pg_lseg)
 815                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 816                                                    req->wb_context,
 817                                                    0,
 818                                                    NFS4_MAX_UINT64,
 819                                                    IOMODE_RW,
 820                                                    GFP_NOFS);
 821         /* If no lseg, fall back to write through mds */
 822         if (pgio->pg_lseg == NULL)
 823                 goto out_mds;
 824
 825         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 826         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 827         if (status < 0)
 828                 goto out_mds;
 829
 830         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 831         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 832             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 833                 goto out_mds;
 834
 835         for (i = 0; i < pgio->pg_mirror_count; i++) {
 836                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
 837                 if (!ds)
 838                         goto out_mds;
 839                 pgm = &pgio->pg_mirrors[i];
 840                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 841                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 842         }
 843
 844         return;
 845
 846 out_mds:
 847         pnfs_put_lseg(pgio->pg_lseg);
 848         pgio->pg_lseg = NULL;
 849         nfs_pageio_reset_write_mds(pgio);
 850 }
 851
 852 static unsigned int
 853 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 854                                     struct nfs_page *req)
 855 {
 856         if (!pgio->pg_lseg)
 857                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 858                                                    req->wb_context,
 859                                                    0,
 860                                                    NFS4_MAX_UINT64,
 861                                                    IOMODE_RW,
 862                                                    GFP_NOFS);
 863         if (pgio->pg_lseg)
 864                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 865
 866         /* no lseg means that pnfs is not in use, so no mirroring here */
 867         nfs_pageio_reset_write_mds(pgio);
 868         return 1;
 869 }
 870
 871 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 872         .pg_init = ff_layout_pg_init_read,
 873         .pg_test = pnfs_generic_pg_test,
 874         .pg_doio = pnfs_generic_pg_readpages,
 875         .pg_cleanup = pnfs_generic_pg_cleanup,
 876 };
 877
 878 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 879         .pg_init = ff_layout_pg_init_write,
 880         .pg_test = pnfs_generic_pg_test,
 881         .pg_doio = pnfs_generic_pg_writepages,
 882         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 883         .pg_cleanup = pnfs_generic_pg_cleanup,
 884 };
 885
 886 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 887 {
 888         struct rpc_task *task = &hdr->task;
 889
 890         pnfs_layoutcommit_inode(hdr->inode, false);
 891
 892         if (retry_pnfs) {
 893                 dprintk("%s Reset task %5u for i/o through pNFS "
 894                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 895                         hdr->task.tk_pid,
 896                         hdr->inode->i_sb->s_id,
 897                         (unsigned long long)NFS_FILEID(hdr->inode),
 898                         hdr->args.count,
 899                         (unsigned long long)hdr->args.offset);
 900
 901                 if (!hdr->dreq) {
 902                         struct nfs_open_context *ctx;
 903
 904                         ctx = nfs_list_entry(hdr->pages.next)->wb_context;
 905                         set_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
 906                         hdr->completion_ops->error_cleanup(&hdr->pages);
 907                 } else {
 908                         nfs_direct_set_resched_writes(hdr->dreq);
 909                         /* fake unstable write to let common nfs resend pages */
 910                         hdr->verf.committed = NFS_UNSTABLE;
 911                         hdr->good_bytes = hdr->args.count;
 912                 }
 913                 return;
 914         }
 915
 916         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 917                 dprintk("%s Reset task %5u for i/o through MDS "
 918                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 919                         hdr->task.tk_pid,
 920                         hdr->inode->i_sb->s_id,
 921                         (unsigned long long)NFS_FILEID(hdr->inode),
 922                         hdr->args.count,
 923                         (unsigned long long)hdr->args.offset);
 924
 925                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
 926         }
 927 }
 928
 929 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
 930 {
 931         struct rpc_task *task = &hdr->task;
 932
 933         pnfs_layoutcommit_inode(hdr->inode, false);
 934
 935         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 936                 dprintk("%s Reset task %5u for i/o through MDS "
 937                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 938                         hdr->task.tk_pid,
 939                         hdr->inode->i_sb->s_id,
 940                         (unsigned long long)NFS_FILEID(hdr->inode),
 941                         hdr->args.count,
 942                         (unsigned long long)hdr->args.offset);
 943
 944                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
 945         }
 946 }
 947
 948 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
 949                                            struct nfs4_state *state,
 950                                            struct nfs_client *clp,
 951                                            struct pnfs_layout_segment *lseg,
 952                                            int idx)
 953 {
 954         struct pnfs_layout_hdr *lo = lseg->pls_layout;
 955         struct inode *inode = lo->plh_inode;
 956         struct nfs_server *mds_server = NFS_SERVER(inode);
 957
 958         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 959         struct nfs_client *mds_client = mds_server->nfs_client;
 960         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 961
 962         if (task->tk_status >= 0)
 963                 return 0;
 964
 965         switch (task->tk_status) {
 966         /* MDS state errors */
 967         case -NFS4ERR_DELEG_REVOKED:
 968         case -NFS4ERR_ADMIN_REVOKED:
 969         case -NFS4ERR_BAD_STATEID:
 970                 if (state == NULL)
 971                         break;
 972                 nfs_remove_bad_delegation(state->inode);
 973         case -NFS4ERR_OPENMODE:
 974                 if (state == NULL)
 975                         break;
 976                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 977                         goto out_bad_stateid;
 978                 goto wait_on_recovery;
 979         case -NFS4ERR_EXPIRED:
 980                 if (state != NULL) {
 981                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 982                                 goto out_bad_stateid;
 983                 }
 984                 nfs4_schedule_lease_recovery(mds_client);
 985                 goto wait_on_recovery;
 986         /* DS session errors */
 987         case -NFS4ERR_BADSESSION:
 988         case -NFS4ERR_BADSLOT:
 989         case -NFS4ERR_BAD_HIGH_SLOT:
 990         case -NFS4ERR_DEADSESSION:
 991         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 992         case -NFS4ERR_SEQ_FALSE_RETRY:
 993         case -NFS4ERR_SEQ_MISORDERED:
 994                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 995                         "flags 0x%x\n", __func__, task->tk_status,
 996                         clp->cl_exchange_flags);
 997                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
 998                 break;
 999         case -NFS4ERR_DELAY:
1000         case -NFS4ERR_GRACE:
1001                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1002                 break;
1003         case -NFS4ERR_RETRY_UNCACHED_REP:
1004                 break;
1005         /* Invalidate Layout errors */
1006         case -NFS4ERR_PNFS_NO_LAYOUT:
1007         case -ESTALE:           /* mapped NFS4ERR_STALE */
1008         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1009         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1010         case -NFS4ERR_FHEXPIRED:
1011         case -NFS4ERR_WRONG_TYPE:
1012                 dprintk("%s Invalid layout error %d\n", __func__,
1013                         task->tk_status);
1014                 /*
1015                  * Destroy layout so new i/o will get a new layout.
1016                  * Layout will not be destroyed until all current lseg
1017                  * references are put. Mark layout as invalid to resend failed
1018                  * i/o and all i/o waiting on the slot table to the MDS until
1019                  * layout is destroyed and a new valid layout is obtained.
1020                  */
1021                 pnfs_destroy_layout(NFS_I(inode));
1022                 rpc_wake_up(&tbl->slot_tbl_waitq);
1023                 goto reset;
1024         /* RPC connection errors */
1025         case -ECONNREFUSED:
1026         case -EHOSTDOWN:
1027         case -EHOSTUNREACH:
1028         case -ENETUNREACH:
1029         case -EIO:
1030         case -ETIMEDOUT:
1031         case -EPIPE:
1032                 dprintk("%s DS connection error %d\n", __func__,
1033                         task->tk_status);
1034                 nfs4_mark_deviceid_unavailable(devid);
1035                 rpc_wake_up(&tbl->slot_tbl_waitq);
1036                 /* fall through */
1037         default:
1038                 if (ff_layout_has_available_ds(lseg))
1039                         return -NFS4ERR_RESET_TO_PNFS;
1040 reset:
1041                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1042                         task->tk_status);
1043                 return -NFS4ERR_RESET_TO_MDS;
1044         }
1045 out:
1046         task->tk_status = 0;
1047         return -EAGAIN;
1048 out_bad_stateid:
1049         task->tk_status = -EIO;
1050         return 0;
1051 wait_on_recovery:
1052         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1053         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1054                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1055         goto out;
1056 }
1057
1058 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1059 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1060                                            struct pnfs_layout_segment *lseg,
1061                                            int idx)
1062 {
1063         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1064
1065         if (task->tk_status >= 0)
1066                 return 0;
1067
1068         switch (task->tk_status) {
1069         /* File access problems. Don't mark the device as unavailable */
1070         case -EACCES:
1071         case -ESTALE:
1072         case -EISDIR:
1073         case -EBADHANDLE:
1074         case -ELOOP:
1075         case -ENOSPC:
1076                 break;
1077         case -EJUKEBOX:
1078                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1079                 goto out_retry;
1080         default:
1081                 dprintk("%s DS connection error %d\n", __func__,
1082                         task->tk_status);
1083                 nfs4_mark_deviceid_unavailable(devid);
1084         }
1085         /* FIXME: Need to prevent infinite looping here. */
1086         return -NFS4ERR_RESET_TO_PNFS;
1087 out_retry:
1088         task->tk_status = 0;
1089         rpc_restart_call(task);
1090         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1091         return -EAGAIN;
1092 }
1093
1094 static int ff_layout_async_handle_error(struct rpc_task *task,
1095                                         struct nfs4_state *state,
1096                                         struct nfs_client *clp,
1097                                         struct pnfs_layout_segment *lseg,
1098                                         int idx)
1099 {
1100         int vers = clp->cl_nfs_mod->rpc_vers->number;
1101
1102         switch (vers) {
1103         case 3:
1104                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1105         case 4:
1106                 return ff_layout_async_handle_error_v4(task, state, clp,
1107                                                        lseg, idx);
1108         default:
1109                 /* should never happen */
1110                 WARN_ON_ONCE(1);
1111                 return 0;
1112         }
1113 }
1114
1115 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1116                                         int idx, u64 offset, u64 length,
1117                                         u32 status, int opnum, int error)
1118 {
1119         struct nfs4_ff_layout_mirror *mirror;
1120         int err;
1121
1122         if (status == 0) {
1123                 switch (error) {
1124                 case -ETIMEDOUT:
1125                 case -EPFNOSUPPORT:
1126                 case -EPROTONOSUPPORT:
1127                 case -EOPNOTSUPP:
1128                 case -ECONNREFUSED:
1129                 case -ECONNRESET:
1130                 case -EHOSTDOWN:
1131                 case -EHOSTUNREACH:
1132                 case -ENETUNREACH:
1133                 case -EADDRINUSE:
1134                 case -ENOBUFS:
1135                 case -EPIPE:
1136                 case -EPERM:
1137                         status = NFS4ERR_NXIO;
1138                         break;
1139                 case -EACCES:
1140                         status = NFS4ERR_ACCESS;
1141                         break;
1142                 default:
1143                         return;
1144                 }
1145         }
1146
1147         mirror = FF_LAYOUT_COMP(lseg, idx);
1148         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1149                                        mirror, offset, length, status, opnum,
1150                                        GFP_NOIO);
1151         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1152         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1153 }
1154
1155 /* NFS_PROTO call done callback routines */
1156
1157 static int ff_layout_read_done_cb(struct rpc_task *task,
1158                                 struct nfs_pgio_header *hdr)
1159 {
1160         int err;
1161
1162         trace_nfs4_pnfs_read(hdr, task->tk_status);
1163         if (task->tk_status < 0)
1164                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1165                                             hdr->args.offset, hdr->args.count,
1166                                             hdr->res.op_status, OP_READ,
1167                                             task->tk_status);
1168         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1169                                            hdr->ds_clp, hdr->lseg,
1170                                            hdr->pgio_mirror_idx);
1171
1172         switch (err) {
1173         case -NFS4ERR_RESET_TO_PNFS:
1174                 set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
1175                         &hdr->lseg->pls_layout->plh_flags);
1176                 pnfs_read_resend_pnfs(hdr);
1177                 return task->tk_status;
1178         case -NFS4ERR_RESET_TO_MDS:
1179                 ff_layout_reset_read(hdr);
1180                 return task->tk_status;
1181         case -EAGAIN:
1182                 rpc_restart_call_prepare(task);
1183                 return -EAGAIN;
1184         }
1185
1186         return 0;
1187 }
1188
1189 static bool
1190 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1191 {
1192         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1193 }
1194
1195 /*
1196  * We reference the rpc_cred of the first WRITE that triggers the need for
1197  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1198  * rfc5661 is not clear about which credential should be used.
1199  *
1200  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1201  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1202  * we always send layoutcommit after DS writes.
1203  */
1204 static void
1205 ff_layout_set_layoutcommit(struct nfs_pgio_header *hdr)
1206 {
1207         if (!ff_layout_need_layoutcommit(hdr->lseg))
1208                 return;
1209
1210         pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
1211                         hdr->mds_offset + hdr->res.count);
1212         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
1213                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
1214 }
1215
1216 static bool
1217 ff_layout_reset_to_mds(struct pnfs_layout_segment *lseg, int idx)
1218 {
1219         /* No mirroring for now */
1220         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1221
1222         return ff_layout_test_devid_unavailable(node);
1223 }
1224
1225 static int ff_layout_read_prepare_common(struct rpc_task *task,
1226                                          struct nfs_pgio_header *hdr)
1227 {
1228         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1229                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1230                         hdr->args.count,
1231                         task->tk_start);
1232
1233         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1234                 rpc_exit(task, -EIO);
1235                 return -EIO;
1236         }
1237         if (ff_layout_reset_to_mds(hdr->lseg, hdr->pgio_mirror_idx)) {
1238                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
1239                 if (ff_layout_has_available_ds(hdr->lseg))
1240                         pnfs_read_resend_pnfs(hdr);
1241                 else
1242                         ff_layout_reset_read(hdr);
1243                 rpc_exit(task, 0);
1244                 return -EAGAIN;
1245         }
1246         hdr->pgio_done_cb = ff_layout_read_done_cb;
1247
1248         return 0;
1249 }
1250
1251 /*
1252  * Call ops for the async read/write cases
1253  * In the case of dense layouts, the offset needs to be reset to its
1254  * original value.
1255  */
1256 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1257 {
1258         struct nfs_pgio_header *hdr = data;
1259
1260         if (ff_layout_read_prepare_common(task, hdr))
1261                 return;
1262
1263         rpc_call_start(task);
1264 }
1265
1266 static int ff_layout_setup_sequence(struct nfs_client *ds_clp,
1267                                     struct nfs4_sequence_args *args,
1268                                     struct nfs4_sequence_res *res,
1269                                     struct rpc_task *task)
1270 {
1271         if (ds_clp->cl_session)
1272                 return nfs41_setup_sequence(ds_clp->cl_session,
1273                                            args,
1274                                            res,
1275                                            task);
1276         return nfs40_setup_sequence(ds_clp->cl_slot_tbl,
1277                                    args,
1278                                    res,
1279                                    task);
1280 }
1281
1282 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1283 {
1284         struct nfs_pgio_header *hdr = data;
1285
1286         if (ff_layout_setup_sequence(hdr->ds_clp,
1287                                      &hdr->args.seq_args,
1288                                      &hdr->res.seq_res,
1289                                      task))
1290                 return;
1291
1292         if (ff_layout_read_prepare_common(task, hdr))
1293                 return;
1294
1295         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1296                         hdr->args.lock_context, FMODE_READ) == -EIO)
1297                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1298 }
1299
1300 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1301 {
1302         struct nfs_pgio_header *hdr = data;
1303
1304         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1305
1306         nfs4_ff_layout_stat_io_end_read(task,
1307                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1308                         hdr->args.count, hdr->res.count);
1309
1310         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1311             task->tk_status == 0) {
1312                 nfs4_sequence_done(task, &hdr->res.seq_res);
1313                 return;
1314         }
1315
1316         /* Note this may cause RPC to be resent */
1317         hdr->mds_ops->rpc_call_done(task, hdr);
1318 }
1319
1320 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1321 {
1322         struct nfs_pgio_header *hdr = data;
1323
1324         rpc_count_iostats_metrics(task,
1325             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1326 }
1327
1328 static int ff_layout_write_done_cb(struct rpc_task *task,
1329                                 struct nfs_pgio_header *hdr)
1330 {
1331         int err;
1332
1333         trace_nfs4_pnfs_write(hdr, task->tk_status);
1334         if (task->tk_status < 0)
1335                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1336                                             hdr->args.offset, hdr->args.count,
1337                                             hdr->res.op_status, OP_WRITE,
1338                                             task->tk_status);
1339         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1340                                            hdr->ds_clp, hdr->lseg,
1341                                            hdr->pgio_mirror_idx);
1342
1343         switch (err) {
1344         case -NFS4ERR_RESET_TO_PNFS:
1345                 pnfs_set_retry_layoutget(hdr->lseg->pls_layout);
1346                 ff_layout_reset_write(hdr, true);
1347                 return task->tk_status;
1348         case -NFS4ERR_RESET_TO_MDS:
1349                 pnfs_clear_retry_layoutget(hdr->lseg->pls_layout);
1350                 ff_layout_reset_write(hdr, false);
1351                 return task->tk_status;
1352         case -EAGAIN:
1353                 rpc_restart_call_prepare(task);
1354                 return -EAGAIN;
1355         }
1356
1357         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1358             hdr->res.verf->committed == NFS_DATA_SYNC)
1359                 ff_layout_set_layoutcommit(hdr);
1360
1361         /* zero out fattr since we don't care DS attr at all */
1362         hdr->fattr.valid = 0;
1363         if (task->tk_status >= 0)
1364                 nfs_writeback_update_inode(hdr);
1365
1366         return 0;
1367 }
1368
1369 static int ff_layout_commit_done_cb(struct rpc_task *task,
1370                                      struct nfs_commit_data *data)
1371 {
1372         int err;
1373
1374         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1375         if (task->tk_status < 0)
1376                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1377                                             data->args.offset, data->args.count,
1378                                             data->res.op_status, OP_COMMIT,
1379                                             task->tk_status);
1380         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1381                                            data->lseg, data->ds_commit_index);
1382
1383         switch (err) {
1384         case -NFS4ERR_RESET_TO_PNFS:
1385                 pnfs_set_retry_layoutget(data->lseg->pls_layout);
1386                 pnfs_generic_prepare_to_resend_writes(data);
1387                 return -EAGAIN;
1388         case -NFS4ERR_RESET_TO_MDS:
1389                 pnfs_clear_retry_layoutget(data->lseg->pls_layout);
1390                 pnfs_generic_prepare_to_resend_writes(data);
1391                 return -EAGAIN;
1392         case -EAGAIN:
1393                 rpc_restart_call_prepare(task);
1394                 return -EAGAIN;
1395         }
1396
1397         if (data->verf.committed == NFS_UNSTABLE
1398             && ff_layout_need_layoutcommit(data->lseg))
1399                 pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
1400
1401         return 0;
1402 }
1403
1404 static int ff_layout_write_prepare_common(struct rpc_task *task,
1405                                           struct nfs_pgio_header *hdr)
1406 {
1407         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1408                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1409                         hdr->args.count,
1410                         task->tk_start);
1411
1412         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1413                 rpc_exit(task, -EIO);
1414                 return -EIO;
1415         }
1416
1417         if (ff_layout_reset_to_mds(hdr->lseg, hdr->pgio_mirror_idx)) {
1418                 bool retry_pnfs;
1419
1420                 retry_pnfs = ff_layout_has_available_ds(hdr->lseg);
1421                 dprintk("%s task %u reset io to %s\n", __func__,
1422                         task->tk_pid, retry_pnfs ? "pNFS" : "MDS");
1423                 ff_layout_reset_write(hdr, retry_pnfs);
1424                 rpc_exit(task, 0);
1425                 return -EAGAIN;
1426         }
1427
1428         return 0;
1429 }
1430
1431 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1432 {
1433         struct nfs_pgio_header *hdr = data;
1434
1435         if (ff_layout_write_prepare_common(task, hdr))
1436                 return;
1437
1438         rpc_call_start(task);
1439 }
1440
1441 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1442 {
1443         struct nfs_pgio_header *hdr = data;
1444
1445         if (ff_layout_setup_sequence(hdr->ds_clp,
1446                                      &hdr->args.seq_args,
1447                                      &hdr->res.seq_res,
1448                                      task))
1449                 return;
1450
1451         if (ff_layout_write_prepare_common(task, hdr))
1452                 return;
1453
1454         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1455                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1456                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1457 }
1458
1459 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1460 {
1461         struct nfs_pgio_header *hdr = data;
1462
1463         nfs4_ff_layout_stat_io_end_write(task,
1464                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1465                         hdr->args.count, hdr->res.count,
1466                         hdr->res.verf->committed);
1467
1468         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1469             task->tk_status == 0) {
1470                 nfs4_sequence_done(task, &hdr->res.seq_res);
1471                 return;
1472         }
1473
1474         /* Note this may cause RPC to be resent */
1475         hdr->mds_ops->rpc_call_done(task, hdr);
1476 }
1477
1478 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1479 {
1480         struct nfs_pgio_header *hdr = data;
1481
1482         rpc_count_iostats_metrics(task,
1483             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1484 }
1485
1486 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1487                 struct nfs_commit_data *cdata)
1488 {
1489         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1490                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1491                         0, task->tk_start);
1492 }
1493
1494 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1495 {
1496         ff_layout_commit_prepare_common(task, data);
1497         rpc_call_start(task);
1498 }
1499
1500 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1501 {
1502         struct nfs_commit_data *wdata = data;
1503
1504         if (ff_layout_setup_sequence(wdata->ds_clp,
1505                                  &wdata->args.seq_args,
1506                                  &wdata->res.seq_res,
1507                                  task))
1508                 return;
1509         ff_layout_commit_prepare_common(task, data);
1510 }
1511
1512 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1513 {
1514         struct nfs_commit_data *cdata = data;
1515         struct nfs_page *req;
1516         __u64 count = 0;
1517
1518         if (task->tk_status == 0) {
1519                 list_for_each_entry(req, &cdata->pages, wb_list)
1520                         count += req->wb_bytes;
1521         }
1522
1523         nfs4_ff_layout_stat_io_end_write(task,
1524                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1525                         count, count, NFS_FILE_SYNC);
1526
1527         pnfs_generic_write_commit_done(task, data);
1528 }
1529
1530 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1531 {
1532         struct nfs_commit_data *cdata = data;
1533
1534         rpc_count_iostats_metrics(task,
1535             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1536 }
1537
1538 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1539         .rpc_call_prepare = ff_layout_read_prepare_v3,
1540         .rpc_call_done = ff_layout_read_call_done,
1541         .rpc_count_stats = ff_layout_read_count_stats,
1542         .rpc_release = pnfs_generic_rw_release,
1543 };
1544
1545 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1546         .rpc_call_prepare = ff_layout_read_prepare_v4,
1547         .rpc_call_done = ff_layout_read_call_done,
1548         .rpc_count_stats = ff_layout_read_count_stats,
1549         .rpc_release = pnfs_generic_rw_release,
1550 };
1551
1552 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1553         .rpc_call_prepare = ff_layout_write_prepare_v3,
1554         .rpc_call_done = ff_layout_write_call_done,
1555         .rpc_count_stats = ff_layout_write_count_stats,
1556         .rpc_release = pnfs_generic_rw_release,
1557 };
1558
1559 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1560         .rpc_call_prepare = ff_layout_write_prepare_v4,
1561         .rpc_call_done = ff_layout_write_call_done,
1562         .rpc_count_stats = ff_layout_write_count_stats,
1563         .rpc_release = pnfs_generic_rw_release,
1564 };
1565
1566 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1567         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1568         .rpc_call_done = ff_layout_commit_done,
1569         .rpc_count_stats = ff_layout_commit_count_stats,
1570         .rpc_release = pnfs_generic_commit_release,
1571 };
1572
1573 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1574         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1575         .rpc_call_done = ff_layout_commit_done,
1576         .rpc_count_stats = ff_layout_commit_count_stats,
1577         .rpc_release = pnfs_generic_commit_release,
1578 };
1579
1580 static enum pnfs_try_status
1581 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1582 {
1583         struct pnfs_layout_segment *lseg = hdr->lseg;
1584         struct nfs4_pnfs_ds *ds;
1585         struct rpc_clnt *ds_clnt;
1586         struct rpc_cred *ds_cred;
1587         loff_t offset = hdr->args.offset;
1588         u32 idx = hdr->pgio_mirror_idx;
1589         int vers;
1590         struct nfs_fh *fh;
1591
1592         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
1593                 __func__, hdr->inode->i_ino,
1594                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1595
1596         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1597         if (!ds)
1598                 goto out_failed;
1599
1600         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1601                                                    hdr->inode);
1602         if (IS_ERR(ds_clnt))
1603                 goto out_failed;
1604
1605         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1606         if (IS_ERR(ds_cred))
1607                 goto out_failed;
1608
1609         vers = nfs4_ff_layout_ds_version(lseg, idx);
1610
1611         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1612                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1613
1614         atomic_inc(&ds->ds_clp->cl_count);
1615         hdr->ds_clp = ds->ds_clp;
1616         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1617         if (fh)
1618                 hdr->args.fh = fh;
1619         /*
1620          * Note that if we ever decide to split across DSes,
1621          * then we may need to handle dense-like offsets.
1622          */
1623         hdr->args.offset = offset;
1624         hdr->mds_offset = offset;
1625
1626         /* Perform an asynchronous read to ds */
1627         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1628                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1629                                       &ff_layout_read_call_ops_v4,
1630                           0, RPC_TASK_SOFTCONN);
1631
1632         return PNFS_ATTEMPTED;
1633
1634 out_failed:
1635         if (ff_layout_has_available_ds(lseg))
1636                 return PNFS_TRY_AGAIN;
1637         return PNFS_NOT_ATTEMPTED;
1638 }
1639
1640 /* Perform async writes. */
1641 static enum pnfs_try_status
1642 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1643 {
1644         struct pnfs_layout_segment *lseg = hdr->lseg;
1645         struct nfs4_pnfs_ds *ds;
1646         struct rpc_clnt *ds_clnt;
1647         struct rpc_cred *ds_cred;
1648         loff_t offset = hdr->args.offset;
1649         int vers;
1650         struct nfs_fh *fh;
1651         int idx = hdr->pgio_mirror_idx;
1652
1653         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1654         if (!ds)
1655                 return PNFS_NOT_ATTEMPTED;
1656
1657         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1658                                                    hdr->inode);
1659         if (IS_ERR(ds_clnt))
1660                 return PNFS_NOT_ATTEMPTED;
1661
1662         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1663         if (IS_ERR(ds_cred))
1664                 return PNFS_NOT_ATTEMPTED;
1665
1666         vers = nfs4_ff_layout_ds_version(lseg, idx);
1667
1668         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d vers %d\n",
1669                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1670                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1671                 vers);
1672
1673         hdr->pgio_done_cb = ff_layout_write_done_cb;
1674         atomic_inc(&ds->ds_clp->cl_count);
1675         hdr->ds_clp = ds->ds_clp;
1676         hdr->ds_commit_idx = idx;
1677         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1678         if (fh)
1679                 hdr->args.fh = fh;
1680
1681         /*
1682          * Note that if we ever decide to split across DSes,
1683          * then we may need to handle dense-like offsets.
1684          */
1685         hdr->args.offset = offset;
1686
1687         /* Perform an asynchronous write */
1688         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1689                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1690                                       &ff_layout_write_call_ops_v4,
1691                           sync, RPC_TASK_SOFTCONN);
1692         return PNFS_ATTEMPTED;
1693 }
1694
1695 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1696 {
1697         return i;
1698 }
1699
1700 static struct nfs_fh *
1701 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1702 {
1703         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1704
1705         /* FIXME: Assume that there is only one NFS version available
1706          * for the DS.
1707          */
1708         return &flseg->mirror_array[i]->fh_versions[0];
1709 }
1710
1711 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1712 {
1713         struct pnfs_layout_segment *lseg = data->lseg;
1714         struct nfs4_pnfs_ds *ds;
1715         struct rpc_clnt *ds_clnt;
1716         struct rpc_cred *ds_cred;
1717         u32 idx;
1718         int vers;
1719         struct nfs_fh *fh;
1720
1721         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1722         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1723         if (!ds)
1724                 goto out_err;
1725
1726         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1727                                                    data->inode);
1728         if (IS_ERR(ds_clnt))
1729                 goto out_err;
1730
1731         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1732         if (IS_ERR(ds_cred))
1733                 goto out_err;
1734
1735         vers = nfs4_ff_layout_ds_version(lseg, idx);
1736
1737         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1738                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1739                 vers);
1740         data->commit_done_cb = ff_layout_commit_done_cb;
1741         data->cred = ds_cred;
1742         atomic_inc(&ds->ds_clp->cl_count);
1743         data->ds_clp = ds->ds_clp;
1744         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1745         if (fh)
1746                 data->args.fh = fh;
1747
1748         return nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1749                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1750                                                &ff_layout_commit_call_ops_v4,
1751                                    how, RPC_TASK_SOFTCONN);
1752 out_err:
1753         pnfs_generic_prepare_to_resend_writes(data);
1754         pnfs_generic_commit_release(data);
1755         return -EAGAIN;
1756 }
1757
1758 static int
1759 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1760                            int how, struct nfs_commit_info *cinfo)
1761 {
1762         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1763                                             ff_layout_initiate_commit);
1764 }
1765
1766 static struct pnfs_ds_commit_info *
1767 ff_layout_get_ds_info(struct inode *inode)
1768 {
1769         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1770
1771         if (layout == NULL)
1772                 return NULL;
1773
1774         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1775 }
1776
1777 static void
1778 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1779 {
1780         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1781                                                   id_node));
1782 }
1783
1784 static int ff_layout_encode_ioerr(struct nfs4_flexfile_layout *flo,
1785                                   struct xdr_stream *xdr,
1786                                   const struct nfs4_layoutreturn_args *args)
1787 {
1788         struct pnfs_layout_hdr *hdr = &flo->generic_hdr;
1789         __be32 *start;
1790         int count = 0, ret = 0;
1791
1792         start = xdr_reserve_space(xdr, 4);
1793         if (unlikely(!start))
1794                 return -E2BIG;
1795
1796         /* This assume we always return _ALL_ layouts */
1797         spin_lock(&hdr->plh_inode->i_lock);
1798         ret = ff_layout_encode_ds_ioerr(flo, xdr, &count, &args->range);
1799         spin_unlock(&hdr->plh_inode->i_lock);
1800
1801         *start = cpu_to_be32(count);
1802
1803         return ret;
1804 }
1805
1806 /* report nothing for now */
1807 static void ff_layout_encode_iostats(struct nfs4_flexfile_layout *flo,
1808                                      struct xdr_stream *xdr,
1809                                      const struct nfs4_layoutreturn_args *args)
1810 {
1811         __be32 *p;
1812
1813         p = xdr_reserve_space(xdr, 4);
1814         if (likely(p))
1815                 *p = cpu_to_be32(0);
1816 }
1817
1818 static struct nfs4_deviceid_node *
1819 ff_layout_alloc_deviceid_node(struct nfs_server *server,
1820                               struct pnfs_device *pdev, gfp_t gfp_flags)
1821 {
1822         struct nfs4_ff_layout_ds *dsaddr;
1823
1824         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
1825         if (!dsaddr)
1826                 return NULL;
1827         return &dsaddr->id_node;
1828 }
1829
1830 static void
1831 ff_layout_encode_layoutreturn(struct pnfs_layout_hdr *lo,
1832                               struct xdr_stream *xdr,
1833                               const struct nfs4_layoutreturn_args *args)
1834 {
1835         struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
1836         __be32 *start;
1837
1838         dprintk("%s: Begin\n", __func__);
1839         start = xdr_reserve_space(xdr, 4);
1840         BUG_ON(!start);
1841
1842         if (ff_layout_encode_ioerr(flo, xdr, args))
1843                 goto out;
1844
1845         ff_layout_encode_iostats(flo, xdr, args);
1846 out:
1847         *start = cpu_to_be32((xdr->p - start - 1) * 4);
1848         dprintk("%s: Return\n", __func__);
1849 }
1850
1851 static int
1852 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
1853 {
1854         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
1855
1856         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
1857 }
1858
1859 static size_t
1860 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
1861                           const int buflen)
1862 {
1863         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
1864         const struct in6_addr *addr = &sin6->sin6_addr;
1865
1866         /*
1867          * RFC 4291, Section 2.2.2
1868          *
1869          * Shorthanded ANY address
1870          */
1871         if (ipv6_addr_any(addr))
1872                 return snprintf(buf, buflen, "::");
1873
1874         /*
1875          * RFC 4291, Section 2.2.2
1876          *
1877          * Shorthanded loopback address
1878          */
1879         if (ipv6_addr_loopback(addr))
1880                 return snprintf(buf, buflen, "::1");
1881
1882         /*
1883          * RFC 4291, Section 2.2.3
1884          *
1885          * Special presentation address format for mapped v4
1886          * addresses.
1887          */
1888         if (ipv6_addr_v4mapped(addr))
1889                 return snprintf(buf, buflen, "::ffff:%pI4",
1890                                         &addr->s6_addr32[3]);
1891
1892         /*
1893          * RFC 4291, Section 2.2.1
1894          */
1895         return snprintf(buf, buflen, "%pI6c", addr);
1896 }
1897
1898 /* Derived from rpc_sockaddr2uaddr */
1899 static void
1900 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
1901 {
1902         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
1903         char portbuf[RPCBIND_MAXUADDRPLEN];
1904         char addrbuf[RPCBIND_MAXUADDRLEN];
1905         char *netid;
1906         unsigned short port;
1907         int len, netid_len;
1908         __be32 *p;
1909
1910         switch (sap->sa_family) {
1911         case AF_INET:
1912                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
1913                         return;
1914                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1915                 netid = "tcp";
1916                 netid_len = 3;
1917                 break;
1918         case AF_INET6:
1919                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
1920                         return;
1921                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
1922                 netid = "tcp6";
1923                 netid_len = 4;
1924                 break;
1925         default:
1926                 /* we only support tcp and tcp6 */
1927                 WARN_ON_ONCE(1);
1928                 return;
1929         }
1930
1931         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
1932         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
1933
1934         p = xdr_reserve_space(xdr, 4 + netid_len);
1935         xdr_encode_opaque(p, netid, netid_len);
1936
1937         p = xdr_reserve_space(xdr, 4 + len);
1938         xdr_encode_opaque(p, addrbuf, len);
1939 }
1940
1941 static void
1942 ff_layout_encode_nfstime(struct xdr_stream *xdr,
1943                          ktime_t t)
1944 {
1945         struct timespec64 ts;
1946         __be32 *p;
1947
1948         p = xdr_reserve_space(xdr, 12);
1949         ts = ktime_to_timespec64(t);
1950         p = xdr_encode_hyper(p, ts.tv_sec);
1951         *p++ = cpu_to_be32(ts.tv_nsec);
1952 }
1953
1954 static void
1955 ff_layout_encode_io_latency(struct xdr_stream *xdr,
1956                             struct nfs4_ff_io_stat *stat)
1957 {
1958         __be32 *p;
1959
1960         p = xdr_reserve_space(xdr, 5 * 8);
1961         p = xdr_encode_hyper(p, stat->ops_requested);
1962         p = xdr_encode_hyper(p, stat->bytes_requested);
1963         p = xdr_encode_hyper(p, stat->ops_completed);
1964         p = xdr_encode_hyper(p, stat->bytes_completed);
1965         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
1966         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
1967         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
1968 }
1969
1970 static void
1971 ff_layout_encode_layoutstats(struct xdr_stream *xdr,
1972                              struct nfs42_layoutstat_args *args,
1973                              struct nfs42_layoutstat_devinfo *devinfo)
1974 {
1975         struct nfs4_ff_layout_mirror *mirror = devinfo->layout_private;
1976         struct nfs4_pnfs_ds_addr *da;
1977         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
1978         struct nfs_fh *fh = &mirror->fh_versions[0];
1979         __be32 *p, *start;
1980
1981         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
1982         dprintk("%s: DS %s: encoding address %s\n",
1983                 __func__, ds->ds_remotestr, da->da_remotestr);
1984         /* layoutupdate length */
1985         start = xdr_reserve_space(xdr, 4);
1986         /* netaddr4 */
1987         ff_layout_encode_netaddr(xdr, da);
1988         /* nfs_fh4 */
1989         p = xdr_reserve_space(xdr, 4 + fh->size);
1990         xdr_encode_opaque(p, fh->data, fh->size);
1991         /* ff_io_latency4 read */
1992         spin_lock(&mirror->lock);
1993         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
1994         /* ff_io_latency4 write */
1995         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
1996         spin_unlock(&mirror->lock);
1997         /* nfstime4 */
1998         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
1999         /* bool */
2000         p = xdr_reserve_space(xdr, 4);
2001         *p = cpu_to_be32(false);
2002
2003         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2004 }
2005
2006 static int
2007 ff_layout_mirror_prepare_stats(struct nfs42_layoutstat_args *args,
2008                                struct pnfs_layout_hdr *lo,
2009                                int dev_limit)
2010 {
2011         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2012         struct nfs4_ff_layout_mirror *mirror;
2013         struct nfs4_deviceid_node *dev;
2014         struct nfs42_layoutstat_devinfo *devinfo;
2015         int i = 0;
2016
2017         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2018                 if (i >= dev_limit)
2019                         break;
2020                 if (!mirror->mirror_ds)
2021                         continue;
2022                 /* mirror refcount put in cleanup_layoutstats */
2023                 if (!atomic_inc_not_zero(&mirror->ref))
2024                         continue;
2025                 dev = &mirror->mirror_ds->id_node;
2026                 devinfo = &args->devinfo[i];
2027                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2028                 devinfo->offset = 0;
2029                 devinfo->length = NFS4_MAX_UINT64;
2030                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2031                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2032                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2033                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2034                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2035                 devinfo->layoutstats_encode = ff_layout_encode_layoutstats;
2036                 devinfo->layout_private = mirror;
2037
2038                 i++;
2039         }
2040         return i;
2041 }
2042
2043 static int
2044 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2045 {
2046         struct nfs4_flexfile_layout *ff_layout;
2047         struct nfs4_ff_layout_mirror *mirror;
2048         int dev_count = 0;
2049
2050         spin_lock(&args->inode->i_lock);
2051         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2052         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2053                 if (atomic_read(&mirror->ref) != 0)
2054                         dev_count ++;
2055         }
2056         spin_unlock(&args->inode->i_lock);
2057         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2058         if (dev_count > PNFS_LAYOUTSTATS_MAXDEV) {
2059                 dprintk("%s: truncating devinfo to limit (%d:%d)\n",
2060                         __func__, dev_count, PNFS_LAYOUTSTATS_MAXDEV);
2061                 dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2062         }
2063         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2064         if (!args->devinfo)
2065                 return -ENOMEM;
2066
2067         spin_lock(&args->inode->i_lock);
2068         args->num_dev = ff_layout_mirror_prepare_stats(args,
2069                         &ff_layout->generic_hdr, dev_count);
2070         spin_unlock(&args->inode->i_lock);
2071
2072         return 0;
2073 }
2074
2075 static void
2076 ff_layout_cleanup_layoutstats(struct nfs42_layoutstat_data *data)
2077 {
2078         struct nfs4_ff_layout_mirror *mirror;
2079         int i;
2080
2081         for (i = 0; i < data->args.num_dev; i++) {
2082                 mirror = data->args.devinfo[i].layout_private;
2083                 data->args.devinfo[i].layout_private = NULL;
2084                 ff_layout_put_mirror(mirror);
2085         }
2086 }
2087
2088 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2089         .id                     = LAYOUT_FLEX_FILES,
2090         .name                   = "LAYOUT_FLEX_FILES",
2091         .owner                  = THIS_MODULE,
2092         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2093         .free_layout_hdr        = ff_layout_free_layout_hdr,
2094         .alloc_lseg             = ff_layout_alloc_lseg,
2095         .free_lseg              = ff_layout_free_lseg,
2096         .add_lseg               = ff_layout_add_lseg,
2097         .pg_read_ops            = &ff_layout_pg_read_ops,
2098         .pg_write_ops           = &ff_layout_pg_write_ops,
2099         .get_ds_info            = ff_layout_get_ds_info,
2100         .free_deviceid_node     = ff_layout_free_deviceid_node,
2101         .mark_request_commit    = pnfs_layout_mark_request_commit,
2102         .clear_request_commit   = pnfs_generic_clear_request_commit,
2103         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2104         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2105         .commit_pagelist        = ff_layout_commit_pagelist,
2106         .read_pagelist          = ff_layout_read_pagelist,
2107         .write_pagelist         = ff_layout_write_pagelist,
2108         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2109         .encode_layoutreturn    = ff_layout_encode_layoutreturn,
2110         .sync                   = pnfs_nfs_generic_sync,
2111         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2112         .cleanup_layoutstats    = ff_layout_cleanup_layoutstats,
2113 };
2114
2115 static int __init nfs4flexfilelayout_init(void)
2116 {
2117         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2118                __func__);
2119         return pnfs_register_layoutdriver(&flexfilelayout_type);
2120 }
2121
2122 static void __exit nfs4flexfilelayout_exit(void)
2123 {
2124         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2125                __func__);
2126         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2127 }
2128
2129 MODULE_ALIAS("nfs-layouttype4-4");
2130
2131 MODULE_LICENSE("GPL");
2132 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2133
2134 module_init(nfs4flexfilelayout_init);
2135 module_exit(nfs4flexfilelayout_exit);