kernel/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; j++) {
 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 void ff_layout_mark_devices_valid(struct nfs4_ff_layout_segment *fls)
 343 {
 344         struct nfs4_deviceid_node *node;
 345         int i;
 346
 347         if (!(fls->flags & FF_FLAGS_NO_IO_THRU_MDS))
 348                 return;
 349         for (i = 0; i < fls->mirror_array_cnt; i++) {
 350                 node = &fls->mirror_array[i]->mirror_ds->id_node;
 351                 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
 352         }
 353 }
 354
 355 static struct pnfs_layout_segment *
 356 ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 357                      struct nfs4_layoutget_res *lgr,
 358                      gfp_t gfp_flags)
 359 {
 360         struct pnfs_layout_segment *ret;
 361         struct nfs4_ff_layout_segment *fls = NULL;
 362         struct xdr_stream stream;
 363         struct xdr_buf buf;
 364         struct page *scratch;
 365         u64 stripe_unit;
 366         u32 mirror_array_cnt;
 367         __be32 *p;
 368         int i, rc;
 369
 370         dprintk("--> %s\n", __func__);
 371         scratch = alloc_page(gfp_flags);
 372         if (!scratch)
 373                 return ERR_PTR(-ENOMEM);
 374
 375         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
 376                               lgr->layoutp->len);
 377         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 378
 379         /* stripe unit and mirror_array_cnt */
 380         rc = -EIO;
 381         p = xdr_inline_decode(&stream, 8 + 4);
 382         if (!p)
 383                 goto out_err_free;
 384
 385         p = xdr_decode_hyper(p, &stripe_unit);
 386         mirror_array_cnt = be32_to_cpup(p++);
 387         dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
 388                 stripe_unit, mirror_array_cnt);
 389
 390         if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
 391             mirror_array_cnt == 0)
 392                 goto out_err_free;
 393
 394         rc = -ENOMEM;
 395         fls = kzalloc(sizeof(*fls), gfp_flags);
 396         if (!fls)
 397                 goto out_err_free;
 398
 399         fls->mirror_array_cnt = mirror_array_cnt;
 400         fls->stripe_unit = stripe_unit;
 401         fls->mirror_array = kcalloc(fls->mirror_array_cnt,
 402                                     sizeof(fls->mirror_array[0]), gfp_flags);
 403         if (fls->mirror_array == NULL)
 404                 goto out_err_free;
 405
 406         for (i = 0; i < fls->mirror_array_cnt; i++) {
 407                 struct nfs4_ff_layout_mirror *mirror;
 408                 struct nfs4_deviceid devid;
 409                 struct nfs4_deviceid_node *idnode;
 410                 u32 ds_count;
 411                 u32 fh_count;
 412                 int j;
 413
 414                 rc = -EIO;
 415                 p = xdr_inline_decode(&stream, 4);
 416                 if (!p)
 417                         goto out_err_free;
 418                 ds_count = be32_to_cpup(p);
 419
 420                 /* FIXME: allow for striping? */
 421                 if (ds_count != 1)
 422                         goto out_err_free;
 423
 424                 fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
 425                 if (fls->mirror_array[i] == NULL) {
 426                         rc = -ENOMEM;
 427                         goto out_err_free;
 428                 }
 429
 430                 fls->mirror_array[i]->ds_count = ds_count;
 431
 432                 /* deviceid */
 433                 rc = decode_deviceid(&stream, &devid);
 434                 if (rc)
 435                         goto out_err_free;
 436
 437                 idnode = nfs4_find_get_deviceid(NFS_SERVER(lh->plh_inode),
 438                                                 &devid, lh->plh_lc_cred,
 439                                                 gfp_flags);
 440                 /*
 441                  * upon success, mirror_ds is allocated by previous
 442                  * getdeviceinfo, or newly by .alloc_deviceid_node
 443                  * nfs4_find_get_deviceid failure is indeed getdeviceinfo falure
 444                  */
 445                 if (idnode)
 446                         fls->mirror_array[i]->mirror_ds =
 447                                 FF_LAYOUT_MIRROR_DS(idnode);
 448                 else
 449                         goto out_err_free;
 450
 451                 /* efficiency */
 452                 rc = -EIO;
 453                 p = xdr_inline_decode(&stream, 4);
 454                 if (!p)
 455                         goto out_err_free;
 456                 fls->mirror_array[i]->efficiency = be32_to_cpup(p);
 457
 458                 /* stateid */
 459                 rc = decode_stateid(&stream, &fls->mirror_array[i]->stateid);
 460                 if (rc)
 461                         goto out_err_free;
 462
 463                 /* fh */
 464                 p = xdr_inline_decode(&stream, 4);
 465                 if (!p)
 466                         goto out_err_free;
 467                 fh_count = be32_to_cpup(p);
 468
 469                 fls->mirror_array[i]->fh_versions =
 470                         kzalloc(fh_count * sizeof(struct nfs_fh),
 471                                 gfp_flags);
 472                 if (fls->mirror_array[i]->fh_versions == NULL) {
 473                         rc = -ENOMEM;
 474                         goto out_err_free;
 475                 }
 476
 477                 for (j = 0; j < fh_count; j++) {
 478                         rc = decode_nfs_fh(&stream,
 479                                            &fls->mirror_array[i]->fh_versions[j]);
 480                         if (rc)
 481                                 goto out_err_free;
 482                 }
 483
 484                 fls->mirror_array[i]->fh_versions_cnt = fh_count;
 485
 486                 /* user */
 487                 rc = decode_name(&stream, &fls->mirror_array[i]->uid);
 488                 if (rc)
 489                         goto out_err_free;
 490
 491                 /* group */
 492                 rc = decode_name(&stream, &fls->mirror_array[i]->gid);
 493                 if (rc)
 494                         goto out_err_free;
 495
 496                 mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
 497                 if (mirror != fls->mirror_array[i]) {
 498                         ff_layout_free_mirror(fls->mirror_array[i]);
 499                         fls->mirror_array[i] = mirror;
 500                 }
 501
 502                 dprintk("%s: uid %d gid %d\n", __func__,
 503                         fls->mirror_array[i]->uid,
 504                         fls->mirror_array[i]->gid);
 505         }
 506
 507         p = xdr_inline_decode(&stream, 4);
 508         if (p)
 509                 fls->flags = be32_to_cpup(p);
 510
 511         ff_layout_sort_mirrors(fls);
 512         rc = ff_layout_check_layout(lgr);
 513         if (rc)
 514                 goto out_err_free;
 515         ff_layout_mark_devices_valid(fls);
 516
 517         ret = &fls->generic_hdr;
 518         dprintk("<-- %s (success)\n", __func__);
 519 out_free_page:
 520         __free_page(scratch);
 521         return ret;
 522 out_err_free:
 523         _ff_layout_free_lseg(fls);
 524         ret = ERR_PTR(rc);
 525         dprintk("<-- %s (%d)\n", __func__, rc);
 526         goto out_free_page;
 527 }
 528
 529 static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
 530 {
 531         struct pnfs_layout_segment *lseg;
 532
 533         list_for_each_entry(lseg, &layout->plh_segs, pls_list)
 534                 if (lseg->pls_range.iomode == IOMODE_RW)
 535                         return true;
 536
 537         return false;
 538 }
 539
 540 static void
 541 ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
 542 {
 543         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 544
 545         dprintk("--> %s\n", __func__);
 546
 547         if (lseg->pls_range.iomode == IOMODE_RW) {
 548                 struct nfs4_flexfile_layout *ffl;
 549                 struct inode *inode;
 550
 551                 ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
 552                 inode = ffl->generic_hdr.plh_inode;
 553                 spin_lock(&inode->i_lock);
 554                 if (!ff_layout_has_rw_segments(lseg->pls_layout)) {
 555                         ffl->commit_info.nbuckets = 0;
 556                         kfree(ffl->commit_info.buckets);
 557                         ffl->commit_info.buckets = NULL;
 558                 }
 559                 spin_unlock(&inode->i_lock);
 560         }
 561         _ff_layout_free_lseg(fls);
 562 }
 563
 564 /* Return 1 until we have multiple lsegs support */
 565 static int
 566 ff_layout_get_lseg_count(struct nfs4_ff_layout_segment *fls)
 567 {
 568         return 1;
 569 }
 570
 571 static void
 572 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 573 {
 574         /* first IO request? */
 575         if (atomic_inc_return(&timer->n_ops) == 1) {
 576                 timer->start_time = now;
 577         }
 578 }
 579
 580 static ktime_t
 581 nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 582 {
 583         ktime_t start;
 584
 585         if (atomic_dec_return(&timer->n_ops) < 0)
 586                 WARN_ON_ONCE(1);
 587
 588         start = timer->start_time;
 589         timer->start_time = now;
 590         return ktime_sub(now, start);
 591 }
 592
 593 static bool
 594 nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
 595                             struct nfs4_ff_layoutstat *layoutstat,
 596                             ktime_t now)
 597 {
 598         static const ktime_t notime = {0};
 599         s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
 600
 601         nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
 602         if (ktime_equal(mirror->start_time, notime))
 603                 mirror->start_time = now;
 604         if (ktime_equal(mirror->last_report_time, notime))
 605                 mirror->last_report_time = now;
 606         if (layoutstats_timer != 0)
 607                 report_interval = (s64)layoutstats_timer * 1000LL;
 608         if (ktime_to_ms(ktime_sub(now, mirror->last_report_time)) >=
 609                         report_interval) {
 610                 mirror->last_report_time = now;
 611                 return true;
 612         }
 613
 614         return false;
 615 }
 616
 617 static void
 618 nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
 619                 __u64 requested)
 620 {
 621         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 622
 623         iostat->ops_requested++;
 624         iostat->bytes_requested += requested;
 625 }
 626
 627 static void
 628 nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
 629                 __u64 requested,
 630                 __u64 completed,
 631                 ktime_t time_completed,
 632                 ktime_t time_started)
 633 {
 634         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 635         ktime_t completion_time = ktime_sub(time_completed, time_started);
 636         ktime_t timer;
 637
 638         iostat->ops_completed++;
 639         iostat->bytes_completed += completed;
 640         iostat->bytes_not_delivered += requested - completed;
 641
 642         timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
 643         iostat->total_busy_time =
 644                         ktime_add(iostat->total_busy_time, timer);
 645         iostat->aggregate_completion_time =
 646                         ktime_add(iostat->aggregate_completion_time,
 647                                         completion_time);
 648 }
 649
 650 static void
 651 nfs4_ff_layout_stat_io_start_read(struct inode *inode,
 652                 struct nfs4_ff_layout_mirror *mirror,
 653                 __u64 requested, ktime_t now)
 654 {
 655         bool report;
 656
 657         spin_lock(&mirror->lock);
 658         report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
 659         nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
 660         spin_unlock(&mirror->lock);
 661
 662         if (report)
 663                 pnfs_report_layoutstat(inode, GFP_KERNEL);
 664 }
 665
 666 static void
 667 nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
 668                 struct nfs4_ff_layout_mirror *mirror,
 669                 __u64 requested,
 670                 __u64 completed)
 671 {
 672         spin_lock(&mirror->lock);
 673         nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
 674                         requested, completed,
 675                         ktime_get(), task->tk_start);
 676         spin_unlock(&mirror->lock);
 677 }
 678
 679 static void
 680 nfs4_ff_layout_stat_io_start_write(struct inode *inode,
 681                 struct nfs4_ff_layout_mirror *mirror,
 682                 __u64 requested, ktime_t now)
 683 {
 684         bool report;
 685
 686         spin_lock(&mirror->lock);
 687         report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
 688         nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
 689         spin_unlock(&mirror->lock);
 690
 691         if (report)
 692                 pnfs_report_layoutstat(inode, GFP_NOIO);
 693 }
 694
 695 static void
 696 nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
 697                 struct nfs4_ff_layout_mirror *mirror,
 698                 __u64 requested,
 699                 __u64 completed,
 700                 enum nfs3_stable_how committed)
 701 {
 702         if (committed == NFS_UNSTABLE)
 703                 requested = completed = 0;
 704
 705         spin_lock(&mirror->lock);
 706         nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
 707                         requested, completed, ktime_get(), task->tk_start);
 708         spin_unlock(&mirror->lock);
 709 }
 710
 711 static int
 712 ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 713                             struct nfs_commit_info *cinfo,
 714                             gfp_t gfp_flags)
 715 {
 716         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 717         struct pnfs_commit_bucket *buckets;
 718         int size;
 719
 720         if (cinfo->ds->nbuckets != 0) {
 721                 /* This assumes there is only one RW lseg per file.
 722                  * To support multiple lseg per file, we need to
 723                  * change struct pnfs_commit_bucket to allow dynamic
 724                  * increasing nbuckets.
 725                  */
 726                 return 0;
 727         }
 728
 729         size = ff_layout_get_lseg_count(fls) * FF_LAYOUT_MIRROR_COUNT(lseg);
 730
 731         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 732                           gfp_flags);
 733         if (!buckets)
 734                 return -ENOMEM;
 735         else {
 736                 int i;
 737
 738                 spin_lock(cinfo->lock);
 739                 if (cinfo->ds->nbuckets != 0)
 740                         kfree(buckets);
 741                 else {
 742                         cinfo->ds->buckets = buckets;
 743                         cinfo->ds->nbuckets = size;
 744                         for (i = 0; i < size; i++) {
 745                                 INIT_LIST_HEAD(&buckets[i].written);
 746                                 INIT_LIST_HEAD(&buckets[i].committing);
 747                                 /* mark direct verifier as unset */
 748                                 buckets[i].direct_verf.committed =
 749                                         NFS_INVALID_STABLE_HOW;
 750                         }
 751                 }
 752                 spin_unlock(cinfo->lock);
 753                 return 0;
 754         }
 755 }
 756
 757 static struct nfs4_pnfs_ds *
 758 ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
 759                                   int start_idx,
 760                                   int *best_idx)
 761 {
 762         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 763         struct nfs4_pnfs_ds *ds;
 764         int idx;
 765
 766         /* mirrors are sorted by efficiency */
 767         for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
 768                 ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
 769                 if (ds) {
 770                         *best_idx = idx;
 771                         return ds;
 772                 }
 773         }
 774
 775         return NULL;
 776 }
 777
 778 static void
 779 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 780                         struct nfs_page *req)
 781 {
 782         struct nfs_pgio_mirror *pgm;
 783         struct nfs4_ff_layout_mirror *mirror;
 784         struct nfs4_pnfs_ds *ds;
 785         int ds_idx;
 786
 787         /* Use full layout for now */
 788         if (!pgio->pg_lseg)
 789                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 790                                                    req->wb_context,
 791                                                    0,
 792                                                    NFS4_MAX_UINT64,
 793                                                    IOMODE_READ,
 794                                                    GFP_KERNEL);
 795         /* If no lseg, fall back to read through mds */
 796         if (pgio->pg_lseg == NULL)
 797                 goto out_mds;
 798
 799         ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
 800         if (!ds)
 801                 goto out_mds;
 802         mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 803
 804         pgio->pg_mirror_idx = ds_idx;
 805
 806         /* read always uses only one mirror - idx 0 for pgio layer */
 807         pgm = &pgio->pg_mirrors[0];
 808         pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 809
 810         return;
 811 out_mds:
 812         pnfs_put_lseg(pgio->pg_lseg);
 813         pgio->pg_lseg = NULL;
 814         nfs_pageio_reset_read_mds(pgio);
 815 }
 816
 817 static void
 818 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 819                         struct nfs_page *req)
 820 {
 821         struct nfs4_ff_layout_mirror *mirror;
 822         struct nfs_pgio_mirror *pgm;
 823         struct nfs_commit_info cinfo;
 824         struct nfs4_pnfs_ds *ds;
 825         int i;
 826         int status;
 827
 828         if (!pgio->pg_lseg)
 829                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 830                                                    req->wb_context,
 831                                                    0,
 832                                                    NFS4_MAX_UINT64,
 833                                                    IOMODE_RW,
 834                                                    GFP_NOFS);
 835         /* If no lseg, fall back to write through mds */
 836         if (pgio->pg_lseg == NULL)
 837                 goto out_mds;
 838
 839         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 840         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 841         if (status < 0)
 842                 goto out_mds;
 843
 844         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 845         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 846             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 847                 goto out_mds;
 848
 849         for (i = 0; i < pgio->pg_mirror_count; i++) {
 850                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
 851                 if (!ds)
 852                         goto out_mds;
 853                 pgm = &pgio->pg_mirrors[i];
 854                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 855                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 856         }
 857
 858         return;
 859
 860 out_mds:
 861         pnfs_put_lseg(pgio->pg_lseg);
 862         pgio->pg_lseg = NULL;
 863         nfs_pageio_reset_write_mds(pgio);
 864 }
 865
 866 static unsigned int
 867 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 868                                     struct nfs_page *req)
 869 {
 870         if (!pgio->pg_lseg)
 871                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 872                                                    req->wb_context,
 873                                                    0,
 874                                                    NFS4_MAX_UINT64,
 875                                                    IOMODE_RW,
 876                                                    GFP_NOFS);
 877         if (pgio->pg_lseg)
 878                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 879
 880         /* no lseg means that pnfs is not in use, so no mirroring here */
 881         nfs_pageio_reset_write_mds(pgio);
 882         return 1;
 883 }
 884
 885 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 886         .pg_init = ff_layout_pg_init_read,
 887         .pg_test = pnfs_generic_pg_test,
 888         .pg_doio = pnfs_generic_pg_readpages,
 889         .pg_cleanup = pnfs_generic_pg_cleanup,
 890 };
 891
 892 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 893         .pg_init = ff_layout_pg_init_write,
 894         .pg_test = pnfs_generic_pg_test,
 895         .pg_doio = pnfs_generic_pg_writepages,
 896         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 897         .pg_cleanup = pnfs_generic_pg_cleanup,
 898 };
 899
 900 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 901 {
 902         struct rpc_task *task = &hdr->task;
 903
 904         pnfs_layoutcommit_inode(hdr->inode, false);
 905
 906         if (retry_pnfs) {
 907                 dprintk("%s Reset task %5u for i/o through pNFS "
 908                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 909                         hdr->task.tk_pid,
 910                         hdr->inode->i_sb->s_id,
 911                         (unsigned long long)NFS_FILEID(hdr->inode),
 912                         hdr->args.count,
 913                         (unsigned long long)hdr->args.offset);
 914
 915                 if (!hdr->dreq) {
 916                         struct nfs_open_context *ctx;
 917
 918                         ctx = nfs_list_entry(hdr->pages.next)->wb_context;
 919                         set_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
 920                         hdr->completion_ops->error_cleanup(&hdr->pages);
 921                 } else {
 922                         nfs_direct_set_resched_writes(hdr->dreq);
 923                         /* fake unstable write to let common nfs resend pages */
 924                         hdr->verf.committed = NFS_UNSTABLE;
 925                         hdr->good_bytes = hdr->args.count;
 926                 }
 927                 return;
 928         }
 929
 930         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 931                 dprintk("%s Reset task %5u for i/o through MDS "
 932                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 933                         hdr->task.tk_pid,
 934                         hdr->inode->i_sb->s_id,
 935                         (unsigned long long)NFS_FILEID(hdr->inode),
 936                         hdr->args.count,
 937                         (unsigned long long)hdr->args.offset);
 938
 939                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
 940         }
 941 }
 942
 943 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
 944 {
 945         struct rpc_task *task = &hdr->task;
 946
 947         pnfs_layoutcommit_inode(hdr->inode, false);
 948
 949         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 950                 dprintk("%s Reset task %5u for i/o through MDS "
 951                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 952                         hdr->task.tk_pid,
 953                         hdr->inode->i_sb->s_id,
 954                         (unsigned long long)NFS_FILEID(hdr->inode),
 955                         hdr->args.count,
 956                         (unsigned long long)hdr->args.offset);
 957
 958                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
 959         }
 960 }
 961
 962 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
 963                                            struct nfs4_state *state,
 964                                            struct nfs_client *clp,
 965                                            struct pnfs_layout_segment *lseg,
 966                                            int idx)
 967 {
 968         struct pnfs_layout_hdr *lo = lseg->pls_layout;
 969         struct inode *inode = lo->plh_inode;
 970         struct nfs_server *mds_server = NFS_SERVER(inode);
 971
 972         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 973         struct nfs_client *mds_client = mds_server->nfs_client;
 974         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 975
 976         if (task->tk_status >= 0)
 977                 return 0;
 978
 979         switch (task->tk_status) {
 980         /* MDS state errors */
 981         case -NFS4ERR_DELEG_REVOKED:
 982         case -NFS4ERR_ADMIN_REVOKED:
 983         case -NFS4ERR_BAD_STATEID:
 984                 if (state == NULL)
 985                         break;
 986                 nfs_remove_bad_delegation(state->inode);
 987         case -NFS4ERR_OPENMODE:
 988                 if (state == NULL)
 989                         break;
 990                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 991                         goto out_bad_stateid;
 992                 goto wait_on_recovery;
 993         case -NFS4ERR_EXPIRED:
 994                 if (state != NULL) {
 995                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 996                                 goto out_bad_stateid;
 997                 }
 998                 nfs4_schedule_lease_recovery(mds_client);
 999                 goto wait_on_recovery;
1000         /* DS session errors */
1001         case -NFS4ERR_BADSESSION:
1002         case -NFS4ERR_BADSLOT:
1003         case -NFS4ERR_BAD_HIGH_SLOT:
1004         case -NFS4ERR_DEADSESSION:
1005         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1006         case -NFS4ERR_SEQ_FALSE_RETRY:
1007         case -NFS4ERR_SEQ_MISORDERED:
1008                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1009                         "flags 0x%x\n", __func__, task->tk_status,
1010                         clp->cl_exchange_flags);
1011                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1012                 break;
1013         case -NFS4ERR_DELAY:
1014         case -NFS4ERR_GRACE:
1015                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1016                 break;
1017         case -NFS4ERR_RETRY_UNCACHED_REP:
1018                 break;
1019         /* Invalidate Layout errors */
1020         case -NFS4ERR_PNFS_NO_LAYOUT:
1021         case -ESTALE:           /* mapped NFS4ERR_STALE */
1022         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1023         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1024         case -NFS4ERR_FHEXPIRED:
1025         case -NFS4ERR_WRONG_TYPE:
1026                 dprintk("%s Invalid layout error %d\n", __func__,
1027                         task->tk_status);
1028                 /*
1029                  * Destroy layout so new i/o will get a new layout.
1030                  * Layout will not be destroyed until all current lseg
1031                  * references are put. Mark layout as invalid to resend failed
1032                  * i/o and all i/o waiting on the slot table to the MDS until
1033                  * layout is destroyed and a new valid layout is obtained.
1034                  */
1035                 pnfs_destroy_layout(NFS_I(inode));
1036                 rpc_wake_up(&tbl->slot_tbl_waitq);
1037                 goto reset;
1038         /* RPC connection errors */
1039         case -ECONNREFUSED:
1040         case -EHOSTDOWN:
1041         case -EHOSTUNREACH:
1042         case -ENETUNREACH:
1043         case -EIO:
1044         case -ETIMEDOUT:
1045         case -EPIPE:
1046                 dprintk("%s DS connection error %d\n", __func__,
1047                         task->tk_status);
1048                 nfs4_mark_deviceid_unavailable(devid);
1049                 rpc_wake_up(&tbl->slot_tbl_waitq);
1050                 /* fall through */
1051         default:
1052                 if (ff_layout_no_fallback_to_mds(lseg) ||
1053                     ff_layout_has_available_ds(lseg))
1054                         return -NFS4ERR_RESET_TO_PNFS;
1055 reset:
1056                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1057                         task->tk_status);
1058                 return -NFS4ERR_RESET_TO_MDS;
1059         }
1060 out:
1061         task->tk_status = 0;
1062         return -EAGAIN;
1063 out_bad_stateid:
1064         task->tk_status = -EIO;
1065         return 0;
1066 wait_on_recovery:
1067         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1068         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1069                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1070         goto out;
1071 }
1072
1073 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1074 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1075                                            struct pnfs_layout_segment *lseg,
1076                                            int idx)
1077 {
1078         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1079
1080         if (task->tk_status >= 0)
1081                 return 0;
1082
1083         switch (task->tk_status) {
1084         /* File access problems. Don't mark the device as unavailable */
1085         case -EACCES:
1086         case -ESTALE:
1087         case -EISDIR:
1088         case -EBADHANDLE:
1089         case -ELOOP:
1090         case -ENOSPC:
1091                 break;
1092         case -EJUKEBOX:
1093                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1094                 goto out_retry;
1095         default:
1096                 dprintk("%s DS connection error %d\n", __func__,
1097                         task->tk_status);
1098                 nfs4_mark_deviceid_unavailable(devid);
1099         }
1100         /* FIXME: Need to prevent infinite looping here. */
1101         return -NFS4ERR_RESET_TO_PNFS;
1102 out_retry:
1103         task->tk_status = 0;
1104         rpc_restart_call(task);
1105         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1106         return -EAGAIN;
1107 }
1108
1109 static int ff_layout_async_handle_error(struct rpc_task *task,
1110                                         struct nfs4_state *state,
1111                                         struct nfs_client *clp,
1112                                         struct pnfs_layout_segment *lseg,
1113                                         int idx)
1114 {
1115         int vers = clp->cl_nfs_mod->rpc_vers->number;
1116
1117         switch (vers) {
1118         case 3:
1119                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1120         case 4:
1121                 return ff_layout_async_handle_error_v4(task, state, clp,
1122                                                        lseg, idx);
1123         default:
1124                 /* should never happen */
1125                 WARN_ON_ONCE(1);
1126                 return 0;
1127         }
1128 }
1129
1130 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1131                                         int idx, u64 offset, u64 length,
1132                                         u32 status, int opnum, int error)
1133 {
1134         struct nfs4_ff_layout_mirror *mirror;
1135         int err;
1136
1137         if (status == 0) {
1138                 switch (error) {
1139                 case -ETIMEDOUT:
1140                 case -EPFNOSUPPORT:
1141                 case -EPROTONOSUPPORT:
1142                 case -EOPNOTSUPP:
1143                 case -ECONNREFUSED:
1144                 case -ECONNRESET:
1145                 case -EHOSTDOWN:
1146                 case -EHOSTUNREACH:
1147                 case -ENETUNREACH:
1148                 case -EADDRINUSE:
1149                 case -ENOBUFS:
1150                 case -EPIPE:
1151                 case -EPERM:
1152                         status = NFS4ERR_NXIO;
1153                         break;
1154                 case -EACCES:
1155                         status = NFS4ERR_ACCESS;
1156                         break;
1157                 default:
1158                         return;
1159                 }
1160         }
1161
1162         mirror = FF_LAYOUT_COMP(lseg, idx);
1163         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1164                                        mirror, offset, length, status, opnum,
1165                                        GFP_NOIO);
1166         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1167         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1168 }
1169
1170 /* NFS_PROTO call done callback routines */
1171 static int ff_layout_read_done_cb(struct rpc_task *task,
1172                                 struct nfs_pgio_header *hdr)
1173 {
1174         int err;
1175
1176         trace_nfs4_pnfs_read(hdr, task->tk_status);
1177         if (task->tk_status < 0)
1178                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1179                                             hdr->args.offset, hdr->args.count,
1180                                             hdr->res.op_status, OP_READ,
1181                                             task->tk_status);
1182         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1183                                            hdr->ds_clp, hdr->lseg,
1184                                            hdr->pgio_mirror_idx);
1185
1186         switch (err) {
1187         case -NFS4ERR_RESET_TO_PNFS:
1188                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1189                                         hdr->pgio_mirror_idx + 1,
1190                                         &hdr->pgio_mirror_idx))
1191                         goto out_eagain;
1192                 set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
1193                         &hdr->lseg->pls_layout->plh_flags);
1194                 pnfs_read_resend_pnfs(hdr);
1195                 return task->tk_status;
1196         case -NFS4ERR_RESET_TO_MDS:
1197                 ff_layout_reset_read(hdr);
1198                 return task->tk_status;
1199         case -EAGAIN:
1200                 goto out_eagain;
1201         }
1202
1203         return 0;
1204 out_eagain:
1205         rpc_restart_call_prepare(task);
1206         return -EAGAIN;
1207 }
1208
1209 static bool
1210 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1211 {
1212         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1213 }
1214
1215 /*
1216  * We reference the rpc_cred of the first WRITE that triggers the need for
1217  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1218  * rfc5661 is not clear about which credential should be used.
1219  *
1220  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1221  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1222  * we always send layoutcommit after DS writes.
1223  */
1224 static void
1225 ff_layout_set_layoutcommit(struct nfs_pgio_header *hdr)
1226 {
1227         if (!ff_layout_need_layoutcommit(hdr->lseg))
1228                 return;
1229
1230         pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
1231                         hdr->mds_offset + hdr->res.count);
1232         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
1233                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
1234 }
1235
1236 static bool
1237 ff_layout_reset_to_mds(struct pnfs_layout_segment *lseg, int idx)
1238 {
1239         /* No mirroring for now */
1240         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1241
1242         return ff_layout_test_devid_unavailable(node);
1243 }
1244
1245 static int ff_layout_read_prepare_common(struct rpc_task *task,
1246                                          struct nfs_pgio_header *hdr)
1247 {
1248         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1249                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1250                         hdr->args.count,
1251                         task->tk_start);
1252
1253         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1254                 rpc_exit(task, -EIO);
1255                 return -EIO;
1256         }
1257         if (ff_layout_reset_to_mds(hdr->lseg, hdr->pgio_mirror_idx)) {
1258                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
1259                 if (ff_layout_has_available_ds(hdr->lseg))
1260                         pnfs_read_resend_pnfs(hdr);
1261                 else
1262                         ff_layout_reset_read(hdr);
1263                 rpc_exit(task, 0);
1264                 return -EAGAIN;
1265         }
1266         hdr->pgio_done_cb = ff_layout_read_done_cb;
1267
1268         return 0;
1269 }
1270
1271 /*
1272  * Call ops for the async read/write cases
1273  * In the case of dense layouts, the offset needs to be reset to its
1274  * original value.
1275  */
1276 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1277 {
1278         struct nfs_pgio_header *hdr = data;
1279
1280         if (ff_layout_read_prepare_common(task, hdr))
1281                 return;
1282
1283         rpc_call_start(task);
1284 }
1285
1286 static int ff_layout_setup_sequence(struct nfs_client *ds_clp,
1287                                     struct nfs4_sequence_args *args,
1288                                     struct nfs4_sequence_res *res,
1289                                     struct rpc_task *task)
1290 {
1291         if (ds_clp->cl_session)
1292                 return nfs41_setup_sequence(ds_clp->cl_session,
1293                                            args,
1294                                            res,
1295                                            task);
1296         return nfs40_setup_sequence(ds_clp->cl_slot_tbl,
1297                                    args,
1298                                    res,
1299                                    task);
1300 }
1301
1302 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1303 {
1304         struct nfs_pgio_header *hdr = data;
1305
1306         if (ff_layout_setup_sequence(hdr->ds_clp,
1307                                      &hdr->args.seq_args,
1308                                      &hdr->res.seq_res,
1309                                      task))
1310                 return;
1311
1312         if (ff_layout_read_prepare_common(task, hdr))
1313                 return;
1314
1315         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1316                         hdr->args.lock_context, FMODE_READ) == -EIO)
1317                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1318 }
1319
1320 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1321 {
1322         struct nfs_pgio_header *hdr = data;
1323
1324         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1325
1326         nfs4_ff_layout_stat_io_end_read(task,
1327                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1328                         hdr->args.count, hdr->res.count);
1329
1330         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1331             task->tk_status == 0) {
1332                 nfs4_sequence_done(task, &hdr->res.seq_res);
1333                 return;
1334         }
1335
1336         /* Note this may cause RPC to be resent */
1337         hdr->mds_ops->rpc_call_done(task, hdr);
1338 }
1339
1340 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1341 {
1342         struct nfs_pgio_header *hdr = data;
1343
1344         rpc_count_iostats_metrics(task,
1345             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1346 }
1347
1348 static int ff_layout_write_done_cb(struct rpc_task *task,
1349                                 struct nfs_pgio_header *hdr)
1350 {
1351         int err;
1352
1353         trace_nfs4_pnfs_write(hdr, task->tk_status);
1354         if (task->tk_status < 0)
1355                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1356                                             hdr->args.offset, hdr->args.count,
1357                                             hdr->res.op_status, OP_WRITE,
1358                                             task->tk_status);
1359         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1360                                            hdr->ds_clp, hdr->lseg,
1361                                            hdr->pgio_mirror_idx);
1362
1363         switch (err) {
1364         case -NFS4ERR_RESET_TO_PNFS:
1365                 pnfs_set_retry_layoutget(hdr->lseg->pls_layout);
1366                 ff_layout_reset_write(hdr, true);
1367                 return task->tk_status;
1368         case -NFS4ERR_RESET_TO_MDS:
1369                 pnfs_clear_retry_layoutget(hdr->lseg->pls_layout);
1370                 ff_layout_reset_write(hdr, false);
1371                 return task->tk_status;
1372         case -EAGAIN:
1373                 rpc_restart_call_prepare(task);
1374                 return -EAGAIN;
1375         }
1376
1377         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1378             hdr->res.verf->committed == NFS_DATA_SYNC)
1379                 ff_layout_set_layoutcommit(hdr);
1380
1381         /* zero out fattr since we don't care DS attr at all */
1382         hdr->fattr.valid = 0;
1383         if (task->tk_status >= 0)
1384                 nfs_writeback_update_inode(hdr);
1385
1386         return 0;
1387 }
1388
1389 static int ff_layout_commit_done_cb(struct rpc_task *task,
1390                                      struct nfs_commit_data *data)
1391 {
1392         int err;
1393
1394         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1395         if (task->tk_status < 0)
1396                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1397                                             data->args.offset, data->args.count,
1398                                             data->res.op_status, OP_COMMIT,
1399                                             task->tk_status);
1400         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1401                                            data->lseg, data->ds_commit_index);
1402
1403         switch (err) {
1404         case -NFS4ERR_RESET_TO_PNFS:
1405                 pnfs_set_retry_layoutget(data->lseg->pls_layout);
1406                 pnfs_generic_prepare_to_resend_writes(data);
1407                 return -EAGAIN;
1408         case -NFS4ERR_RESET_TO_MDS:
1409                 pnfs_clear_retry_layoutget(data->lseg->pls_layout);
1410                 pnfs_generic_prepare_to_resend_writes(data);
1411                 return -EAGAIN;
1412         case -EAGAIN:
1413                 rpc_restart_call_prepare(task);
1414                 return -EAGAIN;
1415         }
1416
1417         if (ff_layout_need_layoutcommit(data->lseg))
1418                 pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
1419
1420         return 0;
1421 }
1422
1423 static int ff_layout_write_prepare_common(struct rpc_task *task,
1424                                           struct nfs_pgio_header *hdr)
1425 {
1426         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1427                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1428                         hdr->args.count,
1429                         task->tk_start);
1430
1431         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1432                 rpc_exit(task, -EIO);
1433                 return -EIO;
1434         }
1435
1436         if (ff_layout_reset_to_mds(hdr->lseg, hdr->pgio_mirror_idx)) {
1437                 bool retry_pnfs;
1438
1439                 retry_pnfs = ff_layout_has_available_ds(hdr->lseg);
1440                 dprintk("%s task %u reset io to %s\n", __func__,
1441                         task->tk_pid, retry_pnfs ? "pNFS" : "MDS");
1442                 ff_layout_reset_write(hdr, retry_pnfs);
1443                 rpc_exit(task, 0);
1444                 return -EAGAIN;
1445         }
1446
1447         return 0;
1448 }
1449
1450 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1451 {
1452         struct nfs_pgio_header *hdr = data;
1453
1454         if (ff_layout_write_prepare_common(task, hdr))
1455                 return;
1456
1457         rpc_call_start(task);
1458 }
1459
1460 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1461 {
1462         struct nfs_pgio_header *hdr = data;
1463
1464         if (ff_layout_setup_sequence(hdr->ds_clp,
1465                                      &hdr->args.seq_args,
1466                                      &hdr->res.seq_res,
1467                                      task))
1468                 return;
1469
1470         if (ff_layout_write_prepare_common(task, hdr))
1471                 return;
1472
1473         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1474                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1475                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1476 }
1477
1478 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1479 {
1480         struct nfs_pgio_header *hdr = data;
1481
1482         nfs4_ff_layout_stat_io_end_write(task,
1483                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1484                         hdr->args.count, hdr->res.count,
1485                         hdr->res.verf->committed);
1486
1487         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1488             task->tk_status == 0) {
1489                 nfs4_sequence_done(task, &hdr->res.seq_res);
1490                 return;
1491         }
1492
1493         /* Note this may cause RPC to be resent */
1494         hdr->mds_ops->rpc_call_done(task, hdr);
1495 }
1496
1497 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1498 {
1499         struct nfs_pgio_header *hdr = data;
1500
1501         rpc_count_iostats_metrics(task,
1502             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1503 }
1504
1505 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1506                 struct nfs_commit_data *cdata)
1507 {
1508         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1509                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1510                         0, task->tk_start);
1511 }
1512
1513 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1514 {
1515         ff_layout_commit_prepare_common(task, data);
1516         rpc_call_start(task);
1517 }
1518
1519 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1520 {
1521         struct nfs_commit_data *wdata = data;
1522
1523         if (ff_layout_setup_sequence(wdata->ds_clp,
1524                                  &wdata->args.seq_args,
1525                                  &wdata->res.seq_res,
1526                                  task))
1527                 return;
1528         ff_layout_commit_prepare_common(task, data);
1529 }
1530
1531 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1532 {
1533         struct nfs_commit_data *cdata = data;
1534         struct nfs_page *req;
1535         __u64 count = 0;
1536
1537         if (task->tk_status == 0) {
1538                 list_for_each_entry(req, &cdata->pages, wb_list)
1539                         count += req->wb_bytes;
1540         }
1541
1542         nfs4_ff_layout_stat_io_end_write(task,
1543                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1544                         count, count, NFS_FILE_SYNC);
1545
1546         pnfs_generic_write_commit_done(task, data);
1547 }
1548
1549 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1550 {
1551         struct nfs_commit_data *cdata = data;
1552
1553         rpc_count_iostats_metrics(task,
1554             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1555 }
1556
1557 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1558         .rpc_call_prepare = ff_layout_read_prepare_v3,
1559         .rpc_call_done = ff_layout_read_call_done,
1560         .rpc_count_stats = ff_layout_read_count_stats,
1561         .rpc_release = pnfs_generic_rw_release,
1562 };
1563
1564 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1565         .rpc_call_prepare = ff_layout_read_prepare_v4,
1566         .rpc_call_done = ff_layout_read_call_done,
1567         .rpc_count_stats = ff_layout_read_count_stats,
1568         .rpc_release = pnfs_generic_rw_release,
1569 };
1570
1571 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1572         .rpc_call_prepare = ff_layout_write_prepare_v3,
1573         .rpc_call_done = ff_layout_write_call_done,
1574         .rpc_count_stats = ff_layout_write_count_stats,
1575         .rpc_release = pnfs_generic_rw_release,
1576 };
1577
1578 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1579         .rpc_call_prepare = ff_layout_write_prepare_v4,
1580         .rpc_call_done = ff_layout_write_call_done,
1581         .rpc_count_stats = ff_layout_write_count_stats,
1582         .rpc_release = pnfs_generic_rw_release,
1583 };
1584
1585 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1586         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1587         .rpc_call_done = ff_layout_commit_done,
1588         .rpc_count_stats = ff_layout_commit_count_stats,
1589         .rpc_release = pnfs_generic_commit_release,
1590 };
1591
1592 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1593         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1594         .rpc_call_done = ff_layout_commit_done,
1595         .rpc_count_stats = ff_layout_commit_count_stats,
1596         .rpc_release = pnfs_generic_commit_release,
1597 };
1598
1599 static enum pnfs_try_status
1600 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1601 {
1602         struct pnfs_layout_segment *lseg = hdr->lseg;
1603         struct nfs4_pnfs_ds *ds;
1604         struct rpc_clnt *ds_clnt;
1605         struct rpc_cred *ds_cred;
1606         loff_t offset = hdr->args.offset;
1607         u32 idx = hdr->pgio_mirror_idx;
1608         int vers;
1609         struct nfs_fh *fh;
1610
1611         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
1612                 __func__, hdr->inode->i_ino,
1613                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1614
1615         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1616         if (!ds)
1617                 goto out_failed;
1618
1619         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1620                                                    hdr->inode);
1621         if (IS_ERR(ds_clnt))
1622                 goto out_failed;
1623
1624         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1625         if (IS_ERR(ds_cred))
1626                 goto out_failed;
1627
1628         vers = nfs4_ff_layout_ds_version(lseg, idx);
1629
1630         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1631                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1632
1633         atomic_inc(&ds->ds_clp->cl_count);
1634         hdr->ds_clp = ds->ds_clp;
1635         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1636         if (fh)
1637                 hdr->args.fh = fh;
1638         /*
1639          * Note that if we ever decide to split across DSes,
1640          * then we may need to handle dense-like offsets.
1641          */
1642         hdr->args.offset = offset;
1643         hdr->mds_offset = offset;
1644
1645         /* Perform an asynchronous read to ds */
1646         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1647                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1648                                       &ff_layout_read_call_ops_v4,
1649                           0, RPC_TASK_SOFTCONN);
1650
1651         return PNFS_ATTEMPTED;
1652
1653 out_failed:
1654         if (ff_layout_has_available_ds(lseg))
1655                 return PNFS_TRY_AGAIN;
1656         return PNFS_NOT_ATTEMPTED;
1657 }
1658
1659 /* Perform async writes. */
1660 static enum pnfs_try_status
1661 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1662 {
1663         struct pnfs_layout_segment *lseg = hdr->lseg;
1664         struct nfs4_pnfs_ds *ds;
1665         struct rpc_clnt *ds_clnt;
1666         struct rpc_cred *ds_cred;
1667         loff_t offset = hdr->args.offset;
1668         int vers;
1669         struct nfs_fh *fh;
1670         int idx = hdr->pgio_mirror_idx;
1671
1672         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1673         if (!ds)
1674                 return PNFS_NOT_ATTEMPTED;
1675
1676         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1677                                                    hdr->inode);
1678         if (IS_ERR(ds_clnt))
1679                 return PNFS_NOT_ATTEMPTED;
1680
1681         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1682         if (IS_ERR(ds_cred))
1683                 return PNFS_NOT_ATTEMPTED;
1684
1685         vers = nfs4_ff_layout_ds_version(lseg, idx);
1686
1687         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d vers %d\n",
1688                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1689                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1690                 vers);
1691
1692         hdr->pgio_done_cb = ff_layout_write_done_cb;
1693         atomic_inc(&ds->ds_clp->cl_count);
1694         hdr->ds_clp = ds->ds_clp;
1695         hdr->ds_commit_idx = idx;
1696         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1697         if (fh)
1698                 hdr->args.fh = fh;
1699
1700         /*
1701          * Note that if we ever decide to split across DSes,
1702          * then we may need to handle dense-like offsets.
1703          */
1704         hdr->args.offset = offset;
1705
1706         /* Perform an asynchronous write */
1707         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1708                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1709                                       &ff_layout_write_call_ops_v4,
1710                           sync, RPC_TASK_SOFTCONN);
1711         return PNFS_ATTEMPTED;
1712 }
1713
1714 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1715 {
1716         return i;
1717 }
1718
1719 static struct nfs_fh *
1720 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1721 {
1722         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1723
1724         /* FIXME: Assume that there is only one NFS version available
1725          * for the DS.
1726          */
1727         return &flseg->mirror_array[i]->fh_versions[0];
1728 }
1729
1730 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1731 {
1732         struct pnfs_layout_segment *lseg = data->lseg;
1733         struct nfs4_pnfs_ds *ds;
1734         struct rpc_clnt *ds_clnt;
1735         struct rpc_cred *ds_cred;
1736         u32 idx;
1737         int vers;
1738         struct nfs_fh *fh;
1739
1740         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1741         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1742         if (!ds)
1743                 goto out_err;
1744
1745         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1746                                                    data->inode);
1747         if (IS_ERR(ds_clnt))
1748                 goto out_err;
1749
1750         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1751         if (IS_ERR(ds_cred))
1752                 goto out_err;
1753
1754         vers = nfs4_ff_layout_ds_version(lseg, idx);
1755
1756         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1757                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1758                 vers);
1759         data->commit_done_cb = ff_layout_commit_done_cb;
1760         data->cred = ds_cred;
1761         atomic_inc(&ds->ds_clp->cl_count);
1762         data->ds_clp = ds->ds_clp;
1763         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1764         if (fh)
1765                 data->args.fh = fh;
1766
1767         return nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1768                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1769                                                &ff_layout_commit_call_ops_v4,
1770                                    how, RPC_TASK_SOFTCONN);
1771 out_err:
1772         pnfs_generic_prepare_to_resend_writes(data);
1773         pnfs_generic_commit_release(data);
1774         return -EAGAIN;
1775 }
1776
1777 static int
1778 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1779                            int how, struct nfs_commit_info *cinfo)
1780 {
1781         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1782                                             ff_layout_initiate_commit);
1783 }
1784
1785 static struct pnfs_ds_commit_info *
1786 ff_layout_get_ds_info(struct inode *inode)
1787 {
1788         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1789
1790         if (layout == NULL)
1791                 return NULL;
1792
1793         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1794 }
1795
1796 static void
1797 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1798 {
1799         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1800                                                   id_node));
1801 }
1802
1803 static int ff_layout_encode_ioerr(struct nfs4_flexfile_layout *flo,
1804                                   struct xdr_stream *xdr,
1805                                   const struct nfs4_layoutreturn_args *args)
1806 {
1807         struct pnfs_layout_hdr *hdr = &flo->generic_hdr;
1808         __be32 *start;
1809         int count = 0, ret = 0;
1810
1811         start = xdr_reserve_space(xdr, 4);
1812         if (unlikely(!start))
1813                 return -E2BIG;
1814
1815         /* This assume we always return _ALL_ layouts */
1816         spin_lock(&hdr->plh_inode->i_lock);
1817         ret = ff_layout_encode_ds_ioerr(flo, xdr, &count, &args->range);
1818         spin_unlock(&hdr->plh_inode->i_lock);
1819
1820         *start = cpu_to_be32(count);
1821
1822         return ret;
1823 }
1824
1825 /* report nothing for now */
1826 static void ff_layout_encode_iostats(struct nfs4_flexfile_layout *flo,
1827                                      struct xdr_stream *xdr,
1828                                      const struct nfs4_layoutreturn_args *args)
1829 {
1830         __be32 *p;
1831
1832         p = xdr_reserve_space(xdr, 4);
1833         if (likely(p))
1834                 *p = cpu_to_be32(0);
1835 }
1836
1837 static struct nfs4_deviceid_node *
1838 ff_layout_alloc_deviceid_node(struct nfs_server *server,
1839                               struct pnfs_device *pdev, gfp_t gfp_flags)
1840 {
1841         struct nfs4_ff_layout_ds *dsaddr;
1842
1843         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
1844         if (!dsaddr)
1845                 return NULL;
1846         return &dsaddr->id_node;
1847 }
1848
1849 static void
1850 ff_layout_encode_layoutreturn(struct pnfs_layout_hdr *lo,
1851                               struct xdr_stream *xdr,
1852                               const struct nfs4_layoutreturn_args *args)
1853 {
1854         struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
1855         __be32 *start;
1856
1857         dprintk("%s: Begin\n", __func__);
1858         start = xdr_reserve_space(xdr, 4);
1859         BUG_ON(!start);
1860
1861         ff_layout_encode_ioerr(flo, xdr, args);
1862         ff_layout_encode_iostats(flo, xdr, args);
1863
1864         *start = cpu_to_be32((xdr->p - start - 1) * 4);
1865         dprintk("%s: Return\n", __func__);
1866 }
1867
1868 static int
1869 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
1870 {
1871         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
1872
1873         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
1874 }
1875
1876 static size_t
1877 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
1878                           const int buflen)
1879 {
1880         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
1881         const struct in6_addr *addr = &sin6->sin6_addr;
1882
1883         /*
1884          * RFC 4291, Section 2.2.2
1885          *
1886          * Shorthanded ANY address
1887          */
1888         if (ipv6_addr_any(addr))
1889                 return snprintf(buf, buflen, "::");
1890
1891         /*
1892          * RFC 4291, Section 2.2.2
1893          *
1894          * Shorthanded loopback address
1895          */
1896         if (ipv6_addr_loopback(addr))
1897                 return snprintf(buf, buflen, "::1");
1898
1899         /*
1900          * RFC 4291, Section 2.2.3
1901          *
1902          * Special presentation address format for mapped v4
1903          * addresses.
1904          */
1905         if (ipv6_addr_v4mapped(addr))
1906                 return snprintf(buf, buflen, "::ffff:%pI4",
1907                                         &addr->s6_addr32[3]);
1908
1909         /*
1910          * RFC 4291, Section 2.2.1
1911          */
1912         return snprintf(buf, buflen, "%pI6c", addr);
1913 }
1914
1915 /* Derived from rpc_sockaddr2uaddr */
1916 static void
1917 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
1918 {
1919         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
1920         char portbuf[RPCBIND_MAXUADDRPLEN];
1921         char addrbuf[RPCBIND_MAXUADDRLEN];
1922         char *netid;
1923         unsigned short port;
1924         int len, netid_len;
1925         __be32 *p;
1926
1927         switch (sap->sa_family) {
1928         case AF_INET:
1929                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
1930                         return;
1931                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1932                 netid = "tcp";
1933                 netid_len = 3;
1934                 break;
1935         case AF_INET6:
1936                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
1937                         return;
1938                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
1939                 netid = "tcp6";
1940                 netid_len = 4;
1941                 break;
1942         default:
1943                 /* we only support tcp and tcp6 */
1944                 WARN_ON_ONCE(1);
1945                 return;
1946         }
1947
1948         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
1949         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
1950
1951         p = xdr_reserve_space(xdr, 4 + netid_len);
1952         xdr_encode_opaque(p, netid, netid_len);
1953
1954         p = xdr_reserve_space(xdr, 4 + len);
1955         xdr_encode_opaque(p, addrbuf, len);
1956 }
1957
1958 static void
1959 ff_layout_encode_nfstime(struct xdr_stream *xdr,
1960                          ktime_t t)
1961 {
1962         struct timespec64 ts;
1963         __be32 *p;
1964
1965         p = xdr_reserve_space(xdr, 12);
1966         ts = ktime_to_timespec64(t);
1967         p = xdr_encode_hyper(p, ts.tv_sec);
1968         *p++ = cpu_to_be32(ts.tv_nsec);
1969 }
1970
1971 static void
1972 ff_layout_encode_io_latency(struct xdr_stream *xdr,
1973                             struct nfs4_ff_io_stat *stat)
1974 {
1975         __be32 *p;
1976
1977         p = xdr_reserve_space(xdr, 5 * 8);
1978         p = xdr_encode_hyper(p, stat->ops_requested);
1979         p = xdr_encode_hyper(p, stat->bytes_requested);
1980         p = xdr_encode_hyper(p, stat->ops_completed);
1981         p = xdr_encode_hyper(p, stat->bytes_completed);
1982         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
1983         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
1984         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
1985 }
1986
1987 static void
1988 ff_layout_encode_layoutstats(struct xdr_stream *xdr,
1989                              struct nfs42_layoutstat_args *args,
1990                              struct nfs42_layoutstat_devinfo *devinfo)
1991 {
1992         struct nfs4_ff_layout_mirror *mirror = devinfo->layout_private;
1993         struct nfs4_pnfs_ds_addr *da;
1994         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
1995         struct nfs_fh *fh = &mirror->fh_versions[0];
1996         __be32 *p, *start;
1997
1998         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
1999         dprintk("%s: DS %s: encoding address %s\n",
2000                 __func__, ds->ds_remotestr, da->da_remotestr);
2001         /* layoutupdate length */
2002         start = xdr_reserve_space(xdr, 4);
2003         /* netaddr4 */
2004         ff_layout_encode_netaddr(xdr, da);
2005         /* nfs_fh4 */
2006         p = xdr_reserve_space(xdr, 4 + fh->size);
2007         xdr_encode_opaque(p, fh->data, fh->size);
2008         /* ff_io_latency4 read */
2009         spin_lock(&mirror->lock);
2010         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2011         /* ff_io_latency4 write */
2012         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2013         spin_unlock(&mirror->lock);
2014         /* nfstime4 */
2015         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2016         /* bool */
2017         p = xdr_reserve_space(xdr, 4);
2018         *p = cpu_to_be32(false);
2019
2020         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2021 }
2022
2023 static int
2024 ff_layout_mirror_prepare_stats(struct nfs42_layoutstat_args *args,
2025                                struct pnfs_layout_hdr *lo,
2026                                int dev_limit)
2027 {
2028         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2029         struct nfs4_ff_layout_mirror *mirror;
2030         struct nfs4_deviceid_node *dev;
2031         struct nfs42_layoutstat_devinfo *devinfo;
2032         int i = 0;
2033
2034         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2035                 if (i >= dev_limit)
2036                         break;
2037                 if (!mirror->mirror_ds)
2038                         continue;
2039                 /* mirror refcount put in cleanup_layoutstats */
2040                 if (!atomic_inc_not_zero(&mirror->ref))
2041                         continue;
2042                 dev = &mirror->mirror_ds->id_node;
2043                 devinfo = &args->devinfo[i];
2044                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2045                 devinfo->offset = 0;
2046                 devinfo->length = NFS4_MAX_UINT64;
2047                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2048                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2049                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2050                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2051                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2052                 devinfo->layoutstats_encode = ff_layout_encode_layoutstats;
2053                 devinfo->layout_private = mirror;
2054
2055                 i++;
2056         }
2057         return i;
2058 }
2059
2060 static int
2061 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2062 {
2063         struct nfs4_flexfile_layout *ff_layout;
2064         struct nfs4_ff_layout_mirror *mirror;
2065         int dev_count = 0;
2066
2067         spin_lock(&args->inode->i_lock);
2068         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2069         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2070                 if (atomic_read(&mirror->ref) != 0)
2071                         dev_count ++;
2072         }
2073         spin_unlock(&args->inode->i_lock);
2074         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2075         if (dev_count > PNFS_LAYOUTSTATS_MAXDEV) {
2076                 dprintk("%s: truncating devinfo to limit (%d:%d)\n",
2077                         __func__, dev_count, PNFS_LAYOUTSTATS_MAXDEV);
2078                 dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2079         }
2080         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2081         if (!args->devinfo)
2082                 return -ENOMEM;
2083
2084         spin_lock(&args->inode->i_lock);
2085         args->num_dev = ff_layout_mirror_prepare_stats(args,
2086                         &ff_layout->generic_hdr, dev_count);
2087         spin_unlock(&args->inode->i_lock);
2088
2089         return 0;
2090 }
2091
2092 static void
2093 ff_layout_cleanup_layoutstats(struct nfs42_layoutstat_data *data)
2094 {
2095         struct nfs4_ff_layout_mirror *mirror;
2096         int i;
2097
2098         for (i = 0; i < data->args.num_dev; i++) {
2099                 mirror = data->args.devinfo[i].layout_private;
2100                 data->args.devinfo[i].layout_private = NULL;
2101                 ff_layout_put_mirror(mirror);
2102         }
2103 }
2104
2105 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2106         .id                     = LAYOUT_FLEX_FILES,
2107         .name                   = "LAYOUT_FLEX_FILES",
2108         .owner                  = THIS_MODULE,
2109         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2110         .free_layout_hdr        = ff_layout_free_layout_hdr,
2111         .alloc_lseg             = ff_layout_alloc_lseg,
2112         .free_lseg              = ff_layout_free_lseg,
2113         .add_lseg               = ff_layout_add_lseg,
2114         .pg_read_ops            = &ff_layout_pg_read_ops,
2115         .pg_write_ops           = &ff_layout_pg_write_ops,
2116         .get_ds_info            = ff_layout_get_ds_info,
2117         .free_deviceid_node     = ff_layout_free_deviceid_node,
2118         .mark_request_commit    = pnfs_layout_mark_request_commit,
2119         .clear_request_commit   = pnfs_generic_clear_request_commit,
2120         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2121         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2122         .commit_pagelist        = ff_layout_commit_pagelist,
2123         .read_pagelist          = ff_layout_read_pagelist,
2124         .write_pagelist         = ff_layout_write_pagelist,
2125         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2126         .encode_layoutreturn    = ff_layout_encode_layoutreturn,
2127         .sync                   = pnfs_nfs_generic_sync,
2128         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2129         .cleanup_layoutstats    = ff_layout_cleanup_layoutstats,
2130 };
2131
2132 static int __init nfs4flexfilelayout_init(void)
2133 {
2134         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2135                __func__);
2136         return pnfs_register_layoutdriver(&flexfilelayout_type);
2137 }
2138
2139 static void __exit nfs4flexfilelayout_exit(void)
2140 {
2141         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2142                __func__);
2143         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2144 }
2145
2146 MODULE_ALIAS("nfs-layouttype4-4");
2147
2148 MODULE_LICENSE("GPL");
2149 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2150
2151 module_init(nfs4flexfilelayout_init);
2152 module_exit(nfs4flexfilelayout_exit);