fs/nfs/flexfilelayout/flexfilelayout.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Module for pnfs flexfile layout driver.
   4  *
   5  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
   6  *
   7  * Tao Peng <bergwolf@primarydata.com>
   8  */
   9
  10 #include <linux/nfs_fs.h>
  11 #include <linux/nfs_page.h>
  12 #include <linux/module.h>
  13 #include <linux/sched/mm.h>
  14
  15 #include <linux/sunrpc/metrics.h>
  16
  17 #include "flexfilelayout.h"
  18 #include "../nfs4session.h"
  19 #include "../nfs4idmap.h"
  20 #include "../internal.h"
  21 #include "../delegation.h"
  22 #include "../nfs4trace.h"
  23 #include "../iostat.h"
  24 #include "../nfs.h"
  25 #include "../nfs42.h"
  26
  27 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  28
  29 #define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)
  30 #define FF_LAYOUTRETURN_MAXERR 20
  31
  32 static unsigned short io_maxretrans;
  33
  34 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
  35                 struct nfs_pgio_header *hdr);
  36 static int ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
  37                                struct nfs42_layoutstat_devinfo *devinfo,
  38                                int dev_limit);
  39 static void ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
  40                               const struct nfs42_layoutstat_devinfo *devinfo,
  41                               struct nfs4_ff_layout_mirror *mirror);
  42
  43 static struct pnfs_layout_hdr *
  44 ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
  45 {
  46         struct nfs4_flexfile_layout *ffl;
  47
  48         ffl = kzalloc(sizeof(*ffl), gfp_flags);
  49         if (ffl) {
  50                 INIT_LIST_HEAD(&ffl->error_list);
  51                 INIT_LIST_HEAD(&ffl->mirrors);
  52                 ffl->last_report_time = ktime_get();
  53                 return &ffl->generic_hdr;
  54         } else
  55                 return NULL;
  56 }
  57
  58 static void
  59 ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
  60 {
  61         struct nfs4_ff_layout_ds_err *err, *n;
  62
  63         list_for_each_entry_safe(err, n, &FF_LAYOUT_FROM_HDR(lo)->error_list,
  64                                  list) {
  65                 list_del(&err->list);
  66                 kfree(err);
  67         }
  68         kfree(FF_LAYOUT_FROM_HDR(lo));
  69 }
  70
  71 static int decode_pnfs_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
  72 {
  73         __be32 *p;
  74
  75         p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
  76         if (unlikely(p == NULL))
  77                 return -ENOBUFS;
  78         stateid->type = NFS4_PNFS_DS_STATEID_TYPE;
  79         memcpy(stateid->data, p, NFS4_STATEID_SIZE);
  80         dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
  81                 p[0], p[1], p[2], p[3]);
  82         return 0;
  83 }
  84
  85 static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
  86 {
  87         __be32 *p;
  88
  89         p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
  90         if (unlikely(!p))
  91                 return -ENOBUFS;
  92         memcpy(devid, p, NFS4_DEVICEID4_SIZE);
  93         nfs4_print_deviceid(devid);
  94         return 0;
  95 }
  96
  97 static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  98 {
  99         __be32 *p;
 100
 101         p = xdr_inline_decode(xdr, 4);
 102         if (unlikely(!p))
 103                 return -ENOBUFS;
 104         fh->size = be32_to_cpup(p++);
 105         if (fh->size > sizeof(struct nfs_fh)) {
 106                 printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
 107                        fh->size);
 108                 return -EOVERFLOW;
 109         }
 110         /* fh.data */
 111         p = xdr_inline_decode(xdr, fh->size);
 112         if (unlikely(!p))
 113                 return -ENOBUFS;
 114         memcpy(&fh->data, p, fh->size);
 115         dprintk("%s: fh len %d\n", __func__, fh->size);
 116
 117         return 0;
 118 }
 119
 120 /*
 121  * Currently only stringified uids and gids are accepted.
 122  * I.e., kerberos is not supported to the DSes, so no pricipals.
 123  *
 124  * That means that one common function will suffice, but when
 125  * principals are added, this should be split to accomodate
 126  * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
 127  */
 128 static int
 129 decode_name(struct xdr_stream *xdr, u32 *id)
 130 {
 131         __be32 *p;
 132         int len;
 133
 134         /* opaque_length(4)*/
 135         p = xdr_inline_decode(xdr, 4);
 136         if (unlikely(!p))
 137                 return -ENOBUFS;
 138         len = be32_to_cpup(p++);
 139         if (len < 0)
 140                 return -EINVAL;
 141
 142         dprintk("%s: len %u\n", __func__, len);
 143
 144         /* opaque body */
 145         p = xdr_inline_decode(xdr, len);
 146         if (unlikely(!p))
 147                 return -ENOBUFS;
 148
 149         if (!nfs_map_string_to_numeric((char *)p, len, id))
 150                 return -EINVAL;
 151
 152         return 0;
 153 }
 154
 155 static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
 156                 const struct nfs4_ff_layout_mirror *m2)
 157 {
 158         int i, j;
 159
 160         if (m1->fh_versions_cnt != m2->fh_versions_cnt)
 161                 return false;
 162         for (i = 0; i < m1->fh_versions_cnt; i++) {
 163                 bool found_fh = false;
 164                 for (j = 0; j < m2->fh_versions_cnt; j++) {
 165                         if (nfs_compare_fh(&m1->fh_versions[i],
 166                                         &m2->fh_versions[j]) == 0) {
 167                                 found_fh = true;
 168                                 break;
 169                         }
 170                 }
 171                 if (!found_fh)
 172                         return false;
 173         }
 174         return true;
 175 }
 176
 177 static struct nfs4_ff_layout_mirror *
 178 ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
 179                 struct nfs4_ff_layout_mirror *mirror)
 180 {
 181         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
 182         struct nfs4_ff_layout_mirror *pos;
 183         struct inode *inode = lo->plh_inode;
 184
 185         spin_lock(&inode->i_lock);
 186         list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
 187                 if (memcmp(&mirror->devid, &pos->devid, sizeof(pos->devid)) != 0)
 188                         continue;
 189                 if (!ff_mirror_match_fh(mirror, pos))
 190                         continue;
 191                 if (refcount_inc_not_zero(&pos->ref)) {
 192                         spin_unlock(&inode->i_lock);
 193                         return pos;
 194                 }
 195         }
 196         list_add(&mirror->mirrors, &ff_layout->mirrors);
 197         mirror->layout = lo;
 198         spin_unlock(&inode->i_lock);
 199         return mirror;
 200 }
 201
 202 static void
 203 ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
 204 {
 205         struct inode *inode;
 206         if (mirror->layout == NULL)
 207                 return;
 208         inode = mirror->layout->plh_inode;
 209         spin_lock(&inode->i_lock);
 210         list_del(&mirror->mirrors);
 211         spin_unlock(&inode->i_lock);
 212         mirror->layout = NULL;
 213 }
 214
 215 static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
 216 {
 217         struct nfs4_ff_layout_mirror *mirror;
 218
 219         mirror = kzalloc(sizeof(*mirror), gfp_flags);
 220         if (mirror != NULL) {
 221                 spin_lock_init(&mirror->lock);
 222                 refcount_set(&mirror->ref, 1);
 223                 INIT_LIST_HEAD(&mirror->mirrors);
 224         }
 225         return mirror;
 226 }
 227
 228 static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
 229 {
 230         const struct cred       *cred;
 231
 232         ff_layout_remove_mirror(mirror);
 233         kfree(mirror->fh_versions);
 234         cred = rcu_access_pointer(mirror->ro_cred);
 235         put_cred(cred);
 236         cred = rcu_access_pointer(mirror->rw_cred);
 237         put_cred(cred);
 238         nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
 239         kfree(mirror);
 240 }
 241
 242 static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
 243 {
 244         if (mirror != NULL && refcount_dec_and_test(&mirror->ref))
 245                 ff_layout_free_mirror(mirror);
 246 }
 247
 248 static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
 249 {
 250         int i;
 251
 252         if (fls->mirror_array) {
 253                 for (i = 0; i < fls->mirror_array_cnt; i++) {
 254                         /* normally mirror_ds is freed in
 255                          * .free_deviceid_node but we still do it here
 256                          * for .alloc_lseg error path */
 257                         ff_layout_put_mirror(fls->mirror_array[i]);
 258                 }
 259                 kfree(fls->mirror_array);
 260                 fls->mirror_array = NULL;
 261         }
 262 }
 263
 264 static int ff_layout_check_layout(struct nfs4_layoutget_res *lgr)
 265 {
 266         int ret = 0;
 267
 268         dprintk("--> %s\n", __func__);
 269
 270         /* FIXME: remove this check when layout segment support is added */
 271         if (lgr->range.offset != 0 ||
 272             lgr->range.length != NFS4_MAX_UINT64) {
 273                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 274                         __func__);
 275                 ret = -EINVAL;
 276         }
 277
 278         dprintk("--> %s returns %d\n", __func__, ret);
 279         return ret;
 280 }
 281
 282 static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
 283 {
 284         if (fls) {
 285                 ff_layout_free_mirror_array(fls);
 286                 kfree(fls);
 287         }
 288 }
 289
 290 static bool
 291 ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
 292                 const struct pnfs_layout_range *l2)
 293 {
 294         u64 end1, end2;
 295
 296         if (l1->iomode != l2->iomode)
 297                 return l1->iomode != IOMODE_READ;
 298         end1 = pnfs_calc_offset_end(l1->offset, l1->length);
 299         end2 = pnfs_calc_offset_end(l2->offset, l2->length);
 300         if (end1 < l2->offset)
 301                 return false;
 302         if (end2 < l1->offset)
 303                 return true;
 304         return l2->offset <= l1->offset;
 305 }
 306
 307 static bool
 308 ff_lseg_merge(struct pnfs_layout_segment *new,
 309                 struct pnfs_layout_segment *old)
 310 {
 311         u64 new_end, old_end;
 312
 313         if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
 314                 return false;
 315         if (new->pls_range.iomode != old->pls_range.iomode)
 316                 return false;
 317         old_end = pnfs_calc_offset_end(old->pls_range.offset,
 318                         old->pls_range.length);
 319         if (old_end < new->pls_range.offset)
 320                 return false;
 321         new_end = pnfs_calc_offset_end(new->pls_range.offset,
 322                         new->pls_range.length);
 323         if (new_end < old->pls_range.offset)
 324                 return false;
 325
 326         /* Mergeable: copy info from 'old' to 'new' */
 327         if (new_end < old_end)
 328                 new_end = old_end;
 329         if (new->pls_range.offset < old->pls_range.offset)
 330                 new->pls_range.offset = old->pls_range.offset;
 331         new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
 332                         new_end);
 333         if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
 334                 set_bit(NFS_LSEG_ROC, &new->pls_flags);
 335         return true;
 336 }
 337
 338 static void
 339 ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
 340                 struct pnfs_layout_segment *lseg,
 341                 struct list_head *free_me)
 342 {
 343         pnfs_generic_layout_insert_lseg(lo, lseg,
 344                         ff_lseg_range_is_after,
 345                         ff_lseg_merge,
 346                         free_me);
 347 }
 348
 349 static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
 350 {
 351         int i, j;
 352
 353         for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
 354                 for (j = i + 1; j < fls->mirror_array_cnt; j++)
 355                         if (fls->mirror_array[i]->efficiency <
 356                             fls->mirror_array[j]->efficiency)
 357                                 swap(fls->mirror_array[i],
 358                                      fls->mirror_array[j]);
 359         }
 360 }
 361
 362 static struct pnfs_layout_segment *
 363 ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 364                      struct nfs4_layoutget_res *lgr,
 365                      gfp_t gfp_flags)
 366 {
 367         struct pnfs_layout_segment *ret;
 368         struct nfs4_ff_layout_segment *fls = NULL;
 369         struct xdr_stream stream;
 370         struct xdr_buf buf;
 371         struct page *scratch;
 372         u64 stripe_unit;
 373         u32 mirror_array_cnt;
 374         __be32 *p;
 375         int i, rc;
 376
 377         dprintk("--> %s\n", __func__);
 378         scratch = alloc_page(gfp_flags);
 379         if (!scratch)
 380                 return ERR_PTR(-ENOMEM);
 381
 382         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
 383                               lgr->layoutp->len);
 384         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 385
 386         /* stripe unit and mirror_array_cnt */
 387         rc = -EIO;
 388         p = xdr_inline_decode(&stream, 8 + 4);
 389         if (!p)
 390                 goto out_err_free;
 391
 392         p = xdr_decode_hyper(p, &stripe_unit);
 393         mirror_array_cnt = be32_to_cpup(p++);
 394         dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
 395                 stripe_unit, mirror_array_cnt);
 396
 397         if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
 398             mirror_array_cnt == 0)
 399                 goto out_err_free;
 400
 401         rc = -ENOMEM;
 402         fls = kzalloc(sizeof(*fls), gfp_flags);
 403         if (!fls)
 404                 goto out_err_free;
 405
 406         fls->mirror_array_cnt = mirror_array_cnt;
 407         fls->stripe_unit = stripe_unit;
 408         fls->mirror_array = kcalloc(fls->mirror_array_cnt,
 409                                     sizeof(fls->mirror_array[0]), gfp_flags);
 410         if (fls->mirror_array == NULL)
 411                 goto out_err_free;
 412
 413         for (i = 0; i < fls->mirror_array_cnt; i++) {
 414                 struct nfs4_ff_layout_mirror *mirror;
 415                 struct cred *kcred;
 416                 const struct cred __rcu *cred;
 417                 kuid_t uid;
 418                 kgid_t gid;
 419                 u32 ds_count, fh_count, id;
 420                 int j;
 421
 422                 rc = -EIO;
 423                 p = xdr_inline_decode(&stream, 4);
 424                 if (!p)
 425                         goto out_err_free;
 426                 ds_count = be32_to_cpup(p);
 427
 428                 /* FIXME: allow for striping? */
 429                 if (ds_count != 1)
 430                         goto out_err_free;
 431
 432                 fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
 433                 if (fls->mirror_array[i] == NULL) {
 434                         rc = -ENOMEM;
 435                         goto out_err_free;
 436                 }
 437
 438                 fls->mirror_array[i]->ds_count = ds_count;
 439
 440                 /* deviceid */
 441                 rc = decode_deviceid(&stream, &fls->mirror_array[i]->devid);
 442                 if (rc)
 443                         goto out_err_free;
 444
 445                 /* efficiency */
 446                 rc = -EIO;
 447                 p = xdr_inline_decode(&stream, 4);
 448                 if (!p)
 449                         goto out_err_free;
 450                 fls->mirror_array[i]->efficiency = be32_to_cpup(p);
 451
 452                 /* stateid */
 453                 rc = decode_pnfs_stateid(&stream, &fls->mirror_array[i]->stateid);
 454                 if (rc)
 455                         goto out_err_free;
 456
 457                 /* fh */
 458                 rc = -EIO;
 459                 p = xdr_inline_decode(&stream, 4);
 460                 if (!p)
 461                         goto out_err_free;
 462                 fh_count = be32_to_cpup(p);
 463
 464                 fls->mirror_array[i]->fh_versions =
 465                         kcalloc(fh_count, sizeof(struct nfs_fh),
 466                                 gfp_flags);
 467                 if (fls->mirror_array[i]->fh_versions == NULL) {
 468                         rc = -ENOMEM;
 469                         goto out_err_free;
 470                 }
 471
 472                 for (j = 0; j < fh_count; j++) {
 473                         rc = decode_nfs_fh(&stream,
 474                                            &fls->mirror_array[i]->fh_versions[j]);
 475                         if (rc)
 476                                 goto out_err_free;
 477                 }
 478
 479                 fls->mirror_array[i]->fh_versions_cnt = fh_count;
 480
 481                 /* user */
 482                 rc = decode_name(&stream, &id);
 483                 if (rc)
 484                         goto out_err_free;
 485
 486                 uid = make_kuid(&init_user_ns, id);
 487
 488                 /* group */
 489                 rc = decode_name(&stream, &id);
 490                 if (rc)
 491                         goto out_err_free;
 492
 493                 gid = make_kgid(&init_user_ns, id);
 494
 495                 if (gfp_flags & __GFP_FS)
 496                         kcred = prepare_kernel_cred(NULL);
 497                 else {
 498                         unsigned int nofs_flags = memalloc_nofs_save();
 499                         kcred = prepare_kernel_cred(NULL);
 500                         memalloc_nofs_restore(nofs_flags);
 501                 }
 502                 rc = -ENOMEM;
 503                 if (!kcred)
 504                         goto out_err_free;
 505                 kcred->fsuid = uid;
 506                 kcred->fsgid = gid;
 507                 cred = RCU_INITIALIZER(kcred);
 508
 509                 if (lgr->range.iomode == IOMODE_READ)
 510                         rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 511                 else
 512                         rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 513
 514                 mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
 515                 if (mirror != fls->mirror_array[i]) {
 516                         /* swap cred ptrs so free_mirror will clean up old */
 517                         if (lgr->range.iomode == IOMODE_READ) {
 518                                 cred = xchg(&mirror->ro_cred, cred);
 519                                 rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 520                         } else {
 521                                 cred = xchg(&mirror->rw_cred, cred);
 522                                 rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 523                         }
 524                         ff_layout_free_mirror(fls->mirror_array[i]);
 525                         fls->mirror_array[i] = mirror;
 526                 }
 527
 528                 dprintk("%s: iomode %s uid %u gid %u\n", __func__,
 529                         lgr->range.iomode == IOMODE_READ ? "READ" : "RW",
 530                         from_kuid(&init_user_ns, uid),
 531                         from_kgid(&init_user_ns, gid));
 532         }
 533
 534         p = xdr_inline_decode(&stream, 4);
 535         if (!p)
 536                 goto out_sort_mirrors;
 537         fls->flags = be32_to_cpup(p);
 538
 539         p = xdr_inline_decode(&stream, 4);
 540         if (!p)
 541                 goto out_sort_mirrors;
 542         for (i=0; i < fls->mirror_array_cnt; i++)
 543                 fls->mirror_array[i]->report_interval = be32_to_cpup(p);
 544
 545 out_sort_mirrors:
 546         ff_layout_sort_mirrors(fls);
 547         rc = ff_layout_check_layout(lgr);
 548         if (rc)
 549                 goto out_err_free;
 550         ret = &fls->generic_hdr;
 551         dprintk("<-- %s (success)\n", __func__);
 552 out_free_page:
 553         __free_page(scratch);
 554         return ret;
 555 out_err_free:
 556         _ff_layout_free_lseg(fls);
 557         ret = ERR_PTR(rc);
 558         dprintk("<-- %s (%d)\n", __func__, rc);
 559         goto out_free_page;
 560 }
 561
 562 static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
 563 {
 564         struct pnfs_layout_segment *lseg;
 565
 566         list_for_each_entry(lseg, &layout->plh_segs, pls_list)
 567                 if (lseg->pls_range.iomode == IOMODE_RW)
 568                         return true;
 569
 570         return false;
 571 }
 572
 573 static void
 574 ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
 575 {
 576         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 577
 578         dprintk("--> %s\n", __func__);
 579
 580         if (lseg->pls_range.iomode == IOMODE_RW) {
 581                 struct nfs4_flexfile_layout *ffl;
 582                 struct inode *inode;
 583
 584                 ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
 585                 inode = ffl->generic_hdr.plh_inode;
 586                 spin_lock(&inode->i_lock);
 587                 if (!ff_layout_has_rw_segments(lseg->pls_layout)) {
 588                         ffl->commit_info.nbuckets = 0;
 589                         kfree(ffl->commit_info.buckets);
 590                         ffl->commit_info.buckets = NULL;
 591                 }
 592                 spin_unlock(&inode->i_lock);
 593         }
 594         _ff_layout_free_lseg(fls);
 595 }
 596
 597 /* Return 1 until we have multiple lsegs support */
 598 static int
 599 ff_layout_get_lseg_count(struct nfs4_ff_layout_segment *fls)
 600 {
 601         return 1;
 602 }
 603
 604 static void
 605 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 606 {
 607         /* first IO request? */
 608         if (atomic_inc_return(&timer->n_ops) == 1) {
 609                 timer->start_time = now;
 610         }
 611 }
 612
 613 static ktime_t
 614 nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 615 {
 616         ktime_t start;
 617
 618         if (atomic_dec_return(&timer->n_ops) < 0)
 619                 WARN_ON_ONCE(1);
 620
 621         start = timer->start_time;
 622         timer->start_time = now;
 623         return ktime_sub(now, start);
 624 }
 625
 626 static bool
 627 nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
 628                             struct nfs4_ff_layoutstat *layoutstat,
 629                             ktime_t now)
 630 {
 631         s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
 632         struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(mirror->layout);
 633
 634         nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
 635         if (!mirror->start_time)
 636                 mirror->start_time = now;
 637         if (mirror->report_interval != 0)
 638                 report_interval = (s64)mirror->report_interval * 1000LL;
 639         else if (layoutstats_timer != 0)
 640                 report_interval = (s64)layoutstats_timer * 1000LL;
 641         if (ktime_to_ms(ktime_sub(now, ffl->last_report_time)) >=
 642                         report_interval) {
 643                 ffl->last_report_time = now;
 644                 return true;
 645         }
 646
 647         return false;
 648 }
 649
 650 static void
 651 nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
 652                 __u64 requested)
 653 {
 654         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 655
 656         iostat->ops_requested++;
 657         iostat->bytes_requested += requested;
 658 }
 659
 660 static void
 661 nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
 662                 __u64 requested,
 663                 __u64 completed,
 664                 ktime_t time_completed,
 665                 ktime_t time_started)
 666 {
 667         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 668         ktime_t completion_time = ktime_sub(time_completed, time_started);
 669         ktime_t timer;
 670
 671         iostat->ops_completed++;
 672         iostat->bytes_completed += completed;
 673         iostat->bytes_not_delivered += requested - completed;
 674
 675         timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
 676         iostat->total_busy_time =
 677                         ktime_add(iostat->total_busy_time, timer);
 678         iostat->aggregate_completion_time =
 679                         ktime_add(iostat->aggregate_completion_time,
 680                                         completion_time);
 681 }
 682
 683 static void
 684 nfs4_ff_layout_stat_io_start_read(struct inode *inode,
 685                 struct nfs4_ff_layout_mirror *mirror,
 686                 __u64 requested, ktime_t now)
 687 {
 688         bool report;
 689
 690         spin_lock(&mirror->lock);
 691         report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
 692         nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
 693         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 694         spin_unlock(&mirror->lock);
 695
 696         if (report)
 697                 pnfs_report_layoutstat(inode, GFP_KERNEL);
 698 }
 699
 700 static void
 701 nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
 702                 struct nfs4_ff_layout_mirror *mirror,
 703                 __u64 requested,
 704                 __u64 completed)
 705 {
 706         spin_lock(&mirror->lock);
 707         nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
 708                         requested, completed,
 709                         ktime_get(), task->tk_start);
 710         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 711         spin_unlock(&mirror->lock);
 712 }
 713
 714 static void
 715 nfs4_ff_layout_stat_io_start_write(struct inode *inode,
 716                 struct nfs4_ff_layout_mirror *mirror,
 717                 __u64 requested, ktime_t now)
 718 {
 719         bool report;
 720
 721         spin_lock(&mirror->lock);
 722         report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
 723         nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
 724         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 725         spin_unlock(&mirror->lock);
 726
 727         if (report)
 728                 pnfs_report_layoutstat(inode, GFP_NOIO);
 729 }
 730
 731 static void
 732 nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
 733                 struct nfs4_ff_layout_mirror *mirror,
 734                 __u64 requested,
 735                 __u64 completed,
 736                 enum nfs3_stable_how committed)
 737 {
 738         if (committed == NFS_UNSTABLE)
 739                 requested = completed = 0;
 740
 741         spin_lock(&mirror->lock);
 742         nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
 743                         requested, completed, ktime_get(), task->tk_start);
 744         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 745         spin_unlock(&mirror->lock);
 746 }
 747
 748 static int
 749 ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 750                             struct nfs_commit_info *cinfo,
 751                             gfp_t gfp_flags)
 752 {
 753         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 754         struct pnfs_commit_bucket *buckets;
 755         int size;
 756
 757         if (cinfo->ds->nbuckets != 0) {
 758                 /* This assumes there is only one RW lseg per file.
 759                  * To support multiple lseg per file, we need to
 760                  * change struct pnfs_commit_bucket to allow dynamic
 761                  * increasing nbuckets.
 762                  */
 763                 return 0;
 764         }
 765
 766         size = ff_layout_get_lseg_count(fls) * FF_LAYOUT_MIRROR_COUNT(lseg);
 767
 768         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 769                           gfp_flags);
 770         if (!buckets)
 771                 return -ENOMEM;
 772         else {
 773                 int i;
 774
 775                 spin_lock(&cinfo->inode->i_lock);
 776                 if (cinfo->ds->nbuckets != 0)
 777                         kfree(buckets);
 778                 else {
 779                         cinfo->ds->buckets = buckets;
 780                         cinfo->ds->nbuckets = size;
 781                         for (i = 0; i < size; i++) {
 782                                 INIT_LIST_HEAD(&buckets[i].written);
 783                                 INIT_LIST_HEAD(&buckets[i].committing);
 784                                 /* mark direct verifier as unset */
 785                                 buckets[i].direct_verf.committed =
 786                                         NFS_INVALID_STABLE_HOW;
 787                         }
 788                 }
 789                 spin_unlock(&cinfo->inode->i_lock);
 790                 return 0;
 791         }
 792 }
 793
 794 static void
 795 ff_layout_mark_ds_unreachable(struct pnfs_layout_segment *lseg, int idx)
 796 {
 797         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 798
 799         if (devid)
 800                 nfs4_mark_deviceid_unavailable(devid);
 801 }
 802
 803 static void
 804 ff_layout_mark_ds_reachable(struct pnfs_layout_segment *lseg, int idx)
 805 {
 806         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 807
 808         if (devid)
 809                 nfs4_mark_deviceid_available(devid);
 810 }
 811
 812 static struct nfs4_pnfs_ds *
 813 ff_layout_choose_ds_for_read(struct pnfs_layout_segment *lseg,
 814                              int start_idx, int *best_idx,
 815                              bool check_device)
 816 {
 817         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 818         struct nfs4_ff_layout_mirror *mirror;
 819         struct nfs4_pnfs_ds *ds;
 820         bool fail_return = false;
 821         int idx;
 822
 823         /* mirrors are initially sorted by efficiency */
 824         for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
 825                 if (idx+1 == fls->mirror_array_cnt)
 826                         fail_return = !check_device;
 827
 828                 mirror = FF_LAYOUT_COMP(lseg, idx);
 829                 ds = nfs4_ff_layout_prepare_ds(lseg, mirror, fail_return);
 830                 if (!ds)
 831                         continue;
 832
 833                 if (check_device &&
 834                     nfs4_test_deviceid_unavailable(&mirror->mirror_ds->id_node))
 835                         continue;
 836
 837                 *best_idx = idx;
 838                 return ds;
 839         }
 840
 841         return NULL;
 842 }
 843
 844 static struct nfs4_pnfs_ds *
 845 ff_layout_choose_any_ds_for_read(struct pnfs_layout_segment *lseg,
 846                                  int start_idx, int *best_idx)
 847 {
 848         return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, false);
 849 }
 850
 851 static struct nfs4_pnfs_ds *
 852 ff_layout_choose_valid_ds_for_read(struct pnfs_layout_segment *lseg,
 853                                    int start_idx, int *best_idx)
 854 {
 855         return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, true);
 856 }
 857
 858 static struct nfs4_pnfs_ds *
 859 ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
 860                                   int start_idx, int *best_idx)
 861 {
 862         struct nfs4_pnfs_ds *ds;
 863
 864         ds = ff_layout_choose_valid_ds_for_read(lseg, start_idx, best_idx);
 865         if (ds)
 866                 return ds;
 867         return ff_layout_choose_any_ds_for_read(lseg, start_idx, best_idx);
 868 }
 869
 870 static void
 871 ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
 872                       struct nfs_page *req,
 873                       bool strict_iomode)
 874 {
 875         pnfs_put_lseg(pgio->pg_lseg);
 876         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 877                                            nfs_req_openctx(req),
 878                                            0,
 879                                            NFS4_MAX_UINT64,
 880                                            IOMODE_READ,
 881                                            strict_iomode,
 882                                            GFP_KERNEL);
 883         if (IS_ERR(pgio->pg_lseg)) {
 884                 pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 885                 pgio->pg_lseg = NULL;
 886         }
 887 }
 888
 889 static void
 890 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 891                         struct nfs_page *req)
 892 {
 893         struct nfs_pgio_mirror *pgm;
 894         struct nfs4_ff_layout_mirror *mirror;
 895         struct nfs4_pnfs_ds *ds;
 896         int ds_idx;
 897
 898 retry:
 899         pnfs_generic_pg_check_layout(pgio);
 900         /* Use full layout for now */
 901         if (!pgio->pg_lseg) {
 902                 ff_layout_pg_get_read(pgio, req, false);
 903                 if (!pgio->pg_lseg)
 904                         goto out_nolseg;
 905         }
 906         if (ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
 907                 ff_layout_pg_get_read(pgio, req, true);
 908                 if (!pgio->pg_lseg)
 909                         goto out_nolseg;
 910         }
 911
 912         ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
 913         if (!ds) {
 914                 if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 915                         goto out_mds;
 916                 pnfs_put_lseg(pgio->pg_lseg);
 917                 pgio->pg_lseg = NULL;
 918                 /* Sleep for 1 second before retrying */
 919                 ssleep(1);
 920                 goto retry;
 921         }
 922
 923         mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 924
 925         pgio->pg_mirror_idx = ds_idx;
 926
 927         /* read always uses only one mirror - idx 0 for pgio layer */
 928         pgm = &pgio->pg_mirrors[0];
 929         pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 930
 931         pgio->pg_maxretrans = io_maxretrans;
 932         return;
 933 out_nolseg:
 934         if (pgio->pg_error < 0)
 935                 return;
 936 out_mds:
 937         trace_pnfs_mds_fallback_pg_init_read(pgio->pg_inode,
 938                         0, NFS4_MAX_UINT64, IOMODE_READ,
 939                         NFS_I(pgio->pg_inode)->layout,
 940                         pgio->pg_lseg);
 941         pnfs_put_lseg(pgio->pg_lseg);
 942         pgio->pg_lseg = NULL;
 943         nfs_pageio_reset_read_mds(pgio);
 944 }
 945
 946 static void
 947 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 948                         struct nfs_page *req)
 949 {
 950         struct nfs4_ff_layout_mirror *mirror;
 951         struct nfs_pgio_mirror *pgm;
 952         struct nfs_commit_info cinfo;
 953         struct nfs4_pnfs_ds *ds;
 954         int i;
 955         int status;
 956
 957 retry:
 958         pnfs_generic_pg_check_layout(pgio);
 959         if (!pgio->pg_lseg) {
 960                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 961                                                    nfs_req_openctx(req),
 962                                                    0,
 963                                                    NFS4_MAX_UINT64,
 964                                                    IOMODE_RW,
 965                                                    false,
 966                                                    GFP_NOFS);
 967                 if (IS_ERR(pgio->pg_lseg)) {
 968                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 969                         pgio->pg_lseg = NULL;
 970                         return;
 971                 }
 972         }
 973         /* If no lseg, fall back to write through mds */
 974         if (pgio->pg_lseg == NULL)
 975                 goto out_mds;
 976
 977         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 978         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 979         if (status < 0)
 980                 goto out_mds;
 981
 982         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 983         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 984             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 985                 goto out_mds;
 986
 987         for (i = 0; i < pgio->pg_mirror_count; i++) {
 988                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 989                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, mirror, true);
 990                 if (!ds) {
 991                         if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 992                                 goto out_mds;
 993                         pnfs_put_lseg(pgio->pg_lseg);
 994                         pgio->pg_lseg = NULL;
 995                         /* Sleep for 1 second before retrying */
 996                         ssleep(1);
 997                         goto retry;
 998                 }
 999                 pgm = &pgio->pg_mirrors[i];
1000                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
1001         }
1002
1003         pgio->pg_maxretrans = io_maxretrans;
1004         return;
1005
1006 out_mds:
1007         trace_pnfs_mds_fallback_pg_init_write(pgio->pg_inode,
1008                         0, NFS4_MAX_UINT64, IOMODE_RW,
1009                         NFS_I(pgio->pg_inode)->layout,
1010                         pgio->pg_lseg);
1011         pnfs_put_lseg(pgio->pg_lseg);
1012         pgio->pg_lseg = NULL;
1013         nfs_pageio_reset_write_mds(pgio);
1014 }
1015
1016 static unsigned int
1017 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
1018                                     struct nfs_page *req)
1019 {
1020         if (!pgio->pg_lseg) {
1021                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1022                                                    nfs_req_openctx(req),
1023                                                    0,
1024                                                    NFS4_MAX_UINT64,
1025                                                    IOMODE_RW,
1026                                                    false,
1027                                                    GFP_NOFS);
1028                 if (IS_ERR(pgio->pg_lseg)) {
1029                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
1030                         pgio->pg_lseg = NULL;
1031                         goto out;
1032                 }
1033         }
1034         if (pgio->pg_lseg)
1035                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
1036
1037         trace_pnfs_mds_fallback_pg_get_mirror_count(pgio->pg_inode,
1038                         0, NFS4_MAX_UINT64, IOMODE_RW,
1039                         NFS_I(pgio->pg_inode)->layout,
1040                         pgio->pg_lseg);
1041         /* no lseg means that pnfs is not in use, so no mirroring here */
1042         nfs_pageio_reset_write_mds(pgio);
1043 out:
1044         return 1;
1045 }
1046
1047 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
1048         .pg_init = ff_layout_pg_init_read,
1049         .pg_test = pnfs_generic_pg_test,
1050         .pg_doio = pnfs_generic_pg_readpages,
1051         .pg_cleanup = pnfs_generic_pg_cleanup,
1052 };
1053
1054 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
1055         .pg_init = ff_layout_pg_init_write,
1056         .pg_test = pnfs_generic_pg_test,
1057         .pg_doio = pnfs_generic_pg_writepages,
1058         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
1059         .pg_cleanup = pnfs_generic_pg_cleanup,
1060 };
1061
1062 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
1063 {
1064         struct rpc_task *task = &hdr->task;
1065
1066         pnfs_layoutcommit_inode(hdr->inode, false);
1067
1068         if (retry_pnfs) {
1069                 dprintk("%s Reset task %5u for i/o through pNFS "
1070                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1071                         hdr->task.tk_pid,
1072                         hdr->inode->i_sb->s_id,
1073                         (unsigned long long)NFS_FILEID(hdr->inode),
1074                         hdr->args.count,
1075                         (unsigned long long)hdr->args.offset);
1076
1077                 hdr->completion_ops->reschedule_io(hdr);
1078                 return;
1079         }
1080
1081         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1082                 dprintk("%s Reset task %5u for i/o through MDS "
1083                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1084                         hdr->task.tk_pid,
1085                         hdr->inode->i_sb->s_id,
1086                         (unsigned long long)NFS_FILEID(hdr->inode),
1087                         hdr->args.count,
1088                         (unsigned long long)hdr->args.offset);
1089
1090                 trace_pnfs_mds_fallback_write_done(hdr->inode,
1091                                 hdr->args.offset, hdr->args.count,
1092                                 IOMODE_RW, NFS_I(hdr->inode)->layout,
1093                                 hdr->lseg);
1094                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1095         }
1096 }
1097
1098 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1099 {
1100         struct rpc_task *task = &hdr->task;
1101
1102         pnfs_layoutcommit_inode(hdr->inode, false);
1103
1104         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1105                 dprintk("%s Reset task %5u for i/o through MDS "
1106                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1107                         hdr->task.tk_pid,
1108                         hdr->inode->i_sb->s_id,
1109                         (unsigned long long)NFS_FILEID(hdr->inode),
1110                         hdr->args.count,
1111                         (unsigned long long)hdr->args.offset);
1112
1113                 trace_pnfs_mds_fallback_read_done(hdr->inode,
1114                                 hdr->args.offset, hdr->args.count,
1115                                 IOMODE_READ, NFS_I(hdr->inode)->layout,
1116                                 hdr->lseg);
1117                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1118         }
1119 }
1120
1121 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1122                                            struct nfs4_state *state,
1123                                            struct nfs_client *clp,
1124                                            struct pnfs_layout_segment *lseg,
1125                                            int idx)
1126 {
1127         struct pnfs_layout_hdr *lo = lseg->pls_layout;
1128         struct inode *inode = lo->plh_inode;
1129         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1130         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1131
1132         switch (task->tk_status) {
1133         case -NFS4ERR_BADSESSION:
1134         case -NFS4ERR_BADSLOT:
1135         case -NFS4ERR_BAD_HIGH_SLOT:
1136         case -NFS4ERR_DEADSESSION:
1137         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1138         case -NFS4ERR_SEQ_FALSE_RETRY:
1139         case -NFS4ERR_SEQ_MISORDERED:
1140                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1141                         "flags 0x%x\n", __func__, task->tk_status,
1142                         clp->cl_exchange_flags);
1143                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1144                 break;
1145         case -NFS4ERR_DELAY:
1146         case -NFS4ERR_GRACE:
1147                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1148                 break;
1149         case -NFS4ERR_RETRY_UNCACHED_REP:
1150                 break;
1151         /* Invalidate Layout errors */
1152         case -NFS4ERR_PNFS_NO_LAYOUT:
1153         case -ESTALE:           /* mapped NFS4ERR_STALE */
1154         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1155         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1156         case -NFS4ERR_FHEXPIRED:
1157         case -NFS4ERR_WRONG_TYPE:
1158                 dprintk("%s Invalid layout error %d\n", __func__,
1159                         task->tk_status);
1160                 /*
1161                  * Destroy layout so new i/o will get a new layout.
1162                  * Layout will not be destroyed until all current lseg
1163                  * references are put. Mark layout as invalid to resend failed
1164                  * i/o and all i/o waiting on the slot table to the MDS until
1165                  * layout is destroyed and a new valid layout is obtained.
1166                  */
1167                 pnfs_destroy_layout(NFS_I(inode));
1168                 rpc_wake_up(&tbl->slot_tbl_waitq);
1169                 goto reset;
1170         /* RPC connection errors */
1171         case -ECONNREFUSED:
1172         case -EHOSTDOWN:
1173         case -EHOSTUNREACH:
1174         case -ENETUNREACH:
1175         case -EIO:
1176         case -ETIMEDOUT:
1177         case -EPIPE:
1178                 dprintk("%s DS connection error %d\n", __func__,
1179                         task->tk_status);
1180                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1181                                 &devid->deviceid);
1182                 rpc_wake_up(&tbl->slot_tbl_waitq);
1183                 /* fall through */
1184         default:
1185                 if (ff_layout_avoid_mds_available_ds(lseg))
1186                         return -NFS4ERR_RESET_TO_PNFS;
1187 reset:
1188                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1189                         task->tk_status);
1190                 return -NFS4ERR_RESET_TO_MDS;
1191         }
1192         task->tk_status = 0;
1193         return -EAGAIN;
1194 }
1195
1196 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1197 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1198                                            struct pnfs_layout_segment *lseg,
1199                                            int idx)
1200 {
1201         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1202
1203         switch (task->tk_status) {
1204         /* File access problems. Don't mark the device as unavailable */
1205         case -EACCES:
1206         case -ESTALE:
1207         case -EISDIR:
1208         case -EBADHANDLE:
1209         case -ELOOP:
1210         case -ENOSPC:
1211                 break;
1212         case -EJUKEBOX:
1213                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1214                 goto out_retry;
1215         default:
1216                 dprintk("%s DS connection error %d\n", __func__,
1217                         task->tk_status);
1218                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1219                                 &devid->deviceid);
1220         }
1221         /* FIXME: Need to prevent infinite looping here. */
1222         return -NFS4ERR_RESET_TO_PNFS;
1223 out_retry:
1224         task->tk_status = 0;
1225         rpc_restart_call_prepare(task);
1226         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1227         return -EAGAIN;
1228 }
1229
1230 static int ff_layout_async_handle_error(struct rpc_task *task,
1231                                         struct nfs4_state *state,
1232                                         struct nfs_client *clp,
1233                                         struct pnfs_layout_segment *lseg,
1234                                         int idx)
1235 {
1236         int vers = clp->cl_nfs_mod->rpc_vers->number;
1237
1238         if (task->tk_status >= 0) {
1239                 ff_layout_mark_ds_reachable(lseg, idx);
1240                 return 0;
1241         }
1242
1243         /* Handle the case of an invalid layout segment */
1244         if (!pnfs_is_valid_lseg(lseg))
1245                 return -NFS4ERR_RESET_TO_PNFS;
1246
1247         switch (vers) {
1248         case 3:
1249                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1250         case 4:
1251                 return ff_layout_async_handle_error_v4(task, state, clp,
1252                                                        lseg, idx);
1253         default:
1254                 /* should never happen */
1255                 WARN_ON_ONCE(1);
1256                 return 0;
1257         }
1258 }
1259
1260 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1261                                         int idx, u64 offset, u64 length,
1262                                         u32 status, int opnum, int error)
1263 {
1264         struct nfs4_ff_layout_mirror *mirror;
1265         int err;
1266
1267         if (status == 0) {
1268                 switch (error) {
1269                 case -ETIMEDOUT:
1270                 case -EPFNOSUPPORT:
1271                 case -EPROTONOSUPPORT:
1272                 case -EOPNOTSUPP:
1273                 case -ECONNREFUSED:
1274                 case -ECONNRESET:
1275                 case -EHOSTDOWN:
1276                 case -EHOSTUNREACH:
1277                 case -ENETUNREACH:
1278                 case -EADDRINUSE:
1279                 case -ENOBUFS:
1280                 case -EPIPE:
1281                 case -EPERM:
1282                         status = NFS4ERR_NXIO;
1283                         break;
1284                 case -EACCES:
1285                         status = NFS4ERR_ACCESS;
1286                         break;
1287                 default:
1288                         return;
1289                 }
1290         }
1291
1292         switch (status) {
1293         case NFS4ERR_DELAY:
1294         case NFS4ERR_GRACE:
1295                 return;
1296         default:
1297                 break;
1298         }
1299
1300         mirror = FF_LAYOUT_COMP(lseg, idx);
1301         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1302                                        mirror, offset, length, status, opnum,
1303                                        GFP_NOIO);
1304         if (status == NFS4ERR_NXIO)
1305                 ff_layout_mark_ds_unreachable(lseg, idx);
1306         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1307         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1308 }
1309
1310 /* NFS_PROTO call done callback routines */
1311 static int ff_layout_read_done_cb(struct rpc_task *task,
1312                                 struct nfs_pgio_header *hdr)
1313 {
1314         int new_idx = hdr->pgio_mirror_idx;
1315         int err;
1316
1317         trace_nfs4_pnfs_read(hdr, task->tk_status);
1318         if (task->tk_status < 0)
1319                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1320                                             hdr->args.offset, hdr->args.count,
1321                                             hdr->res.op_status, OP_READ,
1322                                             task->tk_status);
1323         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1324                                            hdr->ds_clp, hdr->lseg,
1325                                            hdr->pgio_mirror_idx);
1326
1327         clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1328         clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1329         switch (err) {
1330         case -NFS4ERR_RESET_TO_PNFS:
1331                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1332                                         hdr->pgio_mirror_idx + 1,
1333                                         &new_idx))
1334                         goto out_layouterror;
1335                 set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1336                 return task->tk_status;
1337         case -NFS4ERR_RESET_TO_MDS:
1338                 set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1339                 return task->tk_status;
1340         case -EAGAIN:
1341                 goto out_eagain;
1342         }
1343
1344         return 0;
1345 out_layouterror:
1346         ff_layout_read_record_layoutstats_done(task, hdr);
1347         ff_layout_send_layouterror(hdr->lseg);
1348         hdr->pgio_mirror_idx = new_idx;
1349 out_eagain:
1350         rpc_restart_call_prepare(task);
1351         return -EAGAIN;
1352 }
1353
1354 static bool
1355 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1356 {
1357         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1358 }
1359
1360 /*
1361  * We reference the rpc_cred of the first WRITE that triggers the need for
1362  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1363  * rfc5661 is not clear about which credential should be used.
1364  *
1365  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1366  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1367  * we always send layoutcommit after DS writes.
1368  */
1369 static void
1370 ff_layout_set_layoutcommit(struct inode *inode,
1371                 struct pnfs_layout_segment *lseg,
1372                 loff_t end_offset)
1373 {
1374         if (!ff_layout_need_layoutcommit(lseg))
1375                 return;
1376
1377         pnfs_set_layoutcommit(inode, lseg, end_offset);
1378         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1379                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1380 }
1381
1382 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1383                 struct nfs_pgio_header *hdr)
1384 {
1385         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1386                 return;
1387         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1388                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1389                         hdr->args.count,
1390                         task->tk_start);
1391 }
1392
1393 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1394                 struct nfs_pgio_header *hdr)
1395 {
1396         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1397                 return;
1398         nfs4_ff_layout_stat_io_end_read(task,
1399                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1400                         hdr->args.count,
1401                         hdr->res.count);
1402         set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1403 }
1404
1405 static int ff_layout_read_prepare_common(struct rpc_task *task,
1406                                          struct nfs_pgio_header *hdr)
1407 {
1408         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1409                 rpc_exit(task, -EIO);
1410                 return -EIO;
1411         }
1412
1413         ff_layout_read_record_layoutstats_start(task, hdr);
1414         return 0;
1415 }
1416
1417 /*
1418  * Call ops for the async read/write cases
1419  * In the case of dense layouts, the offset needs to be reset to its
1420  * original value.
1421  */
1422 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1423 {
1424         struct nfs_pgio_header *hdr = data;
1425
1426         if (ff_layout_read_prepare_common(task, hdr))
1427                 return;
1428
1429         rpc_call_start(task);
1430 }
1431
1432 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1433 {
1434         struct nfs_pgio_header *hdr = data;
1435
1436         if (nfs4_setup_sequence(hdr->ds_clp,
1437                                 &hdr->args.seq_args,
1438                                 &hdr->res.seq_res,
1439                                 task))
1440                 return;
1441
1442         ff_layout_read_prepare_common(task, hdr);
1443 }
1444
1445 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1446 {
1447         struct nfs_pgio_header *hdr = data;
1448
1449         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1450
1451         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1452             task->tk_status == 0) {
1453                 nfs4_sequence_done(task, &hdr->res.seq_res);
1454                 return;
1455         }
1456
1457         /* Note this may cause RPC to be resent */
1458         hdr->mds_ops->rpc_call_done(task, hdr);
1459 }
1460
1461 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1462 {
1463         struct nfs_pgio_header *hdr = data;
1464
1465         ff_layout_read_record_layoutstats_done(task, hdr);
1466         rpc_count_iostats_metrics(task,
1467             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1468 }
1469
1470 static void ff_layout_read_release(void *data)
1471 {
1472         struct nfs_pgio_header *hdr = data;
1473
1474         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1475         if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags)) {
1476                 ff_layout_send_layouterror(hdr->lseg);
1477                 pnfs_read_resend_pnfs(hdr);
1478         } else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1479                 ff_layout_reset_read(hdr);
1480         pnfs_generic_rw_release(data);
1481 }
1482
1483
1484 static int ff_layout_write_done_cb(struct rpc_task *task,
1485                                 struct nfs_pgio_header *hdr)
1486 {
1487         loff_t end_offs = 0;
1488         int err;
1489
1490         trace_nfs4_pnfs_write(hdr, task->tk_status);
1491         if (task->tk_status < 0)
1492                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1493                                             hdr->args.offset, hdr->args.count,
1494                                             hdr->res.op_status, OP_WRITE,
1495                                             task->tk_status);
1496         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1497                                            hdr->ds_clp, hdr->lseg,
1498                                            hdr->pgio_mirror_idx);
1499
1500         clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1501         clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1502         switch (err) {
1503         case -NFS4ERR_RESET_TO_PNFS:
1504                 set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1505                 return task->tk_status;
1506         case -NFS4ERR_RESET_TO_MDS:
1507                 set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1508                 return task->tk_status;
1509         case -EAGAIN:
1510                 return -EAGAIN;
1511         }
1512
1513         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1514             hdr->res.verf->committed == NFS_DATA_SYNC)
1515                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1516
1517         /* Note: if the write is unstable, don't set end_offs until commit */
1518         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1519
1520         /* zero out fattr since we don't care DS attr at all */
1521         hdr->fattr.valid = 0;
1522         if (task->tk_status >= 0)
1523                 nfs_writeback_update_inode(hdr);
1524
1525         return 0;
1526 }
1527
1528 static int ff_layout_commit_done_cb(struct rpc_task *task,
1529                                      struct nfs_commit_data *data)
1530 {
1531         int err;
1532
1533         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1534         if (task->tk_status < 0)
1535                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1536                                             data->args.offset, data->args.count,
1537                                             data->res.op_status, OP_COMMIT,
1538                                             task->tk_status);
1539         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1540                                            data->lseg, data->ds_commit_index);
1541
1542         switch (err) {
1543         case -NFS4ERR_RESET_TO_PNFS:
1544                 pnfs_generic_prepare_to_resend_writes(data);
1545                 return -EAGAIN;
1546         case -NFS4ERR_RESET_TO_MDS:
1547                 pnfs_generic_prepare_to_resend_writes(data);
1548                 return -EAGAIN;
1549         case -EAGAIN:
1550                 rpc_restart_call_prepare(task);
1551                 return -EAGAIN;
1552         }
1553
1554         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1555
1556         return 0;
1557 }
1558
1559 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1560                 struct nfs_pgio_header *hdr)
1561 {
1562         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1563                 return;
1564         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1565                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1566                         hdr->args.count,
1567                         task->tk_start);
1568 }
1569
1570 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1571                 struct nfs_pgio_header *hdr)
1572 {
1573         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1574                 return;
1575         nfs4_ff_layout_stat_io_end_write(task,
1576                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1577                         hdr->args.count, hdr->res.count,
1578                         hdr->res.verf->committed);
1579         set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1580 }
1581
1582 static int ff_layout_write_prepare_common(struct rpc_task *task,
1583                                           struct nfs_pgio_header *hdr)
1584 {
1585         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1586                 rpc_exit(task, -EIO);
1587                 return -EIO;
1588         }
1589
1590         ff_layout_write_record_layoutstats_start(task, hdr);
1591         return 0;
1592 }
1593
1594 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1595 {
1596         struct nfs_pgio_header *hdr = data;
1597
1598         if (ff_layout_write_prepare_common(task, hdr))
1599                 return;
1600
1601         rpc_call_start(task);
1602 }
1603
1604 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1605 {
1606         struct nfs_pgio_header *hdr = data;
1607
1608         if (nfs4_setup_sequence(hdr->ds_clp,
1609                                 &hdr->args.seq_args,
1610                                 &hdr->res.seq_res,
1611                                 task))
1612                 return;
1613
1614         ff_layout_write_prepare_common(task, hdr);
1615 }
1616
1617 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1618 {
1619         struct nfs_pgio_header *hdr = data;
1620
1621         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1622             task->tk_status == 0) {
1623                 nfs4_sequence_done(task, &hdr->res.seq_res);
1624                 return;
1625         }
1626
1627         /* Note this may cause RPC to be resent */
1628         hdr->mds_ops->rpc_call_done(task, hdr);
1629 }
1630
1631 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1632 {
1633         struct nfs_pgio_header *hdr = data;
1634
1635         ff_layout_write_record_layoutstats_done(task, hdr);
1636         rpc_count_iostats_metrics(task,
1637             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1638 }
1639
1640 static void ff_layout_write_release(void *data)
1641 {
1642         struct nfs_pgio_header *hdr = data;
1643
1644         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1645         if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags)) {
1646                 ff_layout_send_layouterror(hdr->lseg);
1647                 ff_layout_reset_write(hdr, true);
1648         } else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1649                 ff_layout_reset_write(hdr, false);
1650         pnfs_generic_rw_release(data);
1651 }
1652
1653 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1654                 struct nfs_commit_data *cdata)
1655 {
1656         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1657                 return;
1658         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1659                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1660                         0, task->tk_start);
1661 }
1662
1663 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1664                 struct nfs_commit_data *cdata)
1665 {
1666         struct nfs_page *req;
1667         __u64 count = 0;
1668
1669         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1670                 return;
1671
1672         if (task->tk_status == 0) {
1673                 list_for_each_entry(req, &cdata->pages, wb_list)
1674                         count += req->wb_bytes;
1675         }
1676         nfs4_ff_layout_stat_io_end_write(task,
1677                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1678                         count, count, NFS_FILE_SYNC);
1679         set_bit(NFS_LSEG_LAYOUTRETURN, &cdata->lseg->pls_flags);
1680 }
1681
1682 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1683                 struct nfs_commit_data *cdata)
1684 {
1685         ff_layout_commit_record_layoutstats_start(task, cdata);
1686 }
1687
1688 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1689 {
1690         ff_layout_commit_prepare_common(task, data);
1691         rpc_call_start(task);
1692 }
1693
1694 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1695 {
1696         struct nfs_commit_data *wdata = data;
1697
1698         if (nfs4_setup_sequence(wdata->ds_clp,
1699                                 &wdata->args.seq_args,
1700                                 &wdata->res.seq_res,
1701                                 task))
1702                 return;
1703         ff_layout_commit_prepare_common(task, data);
1704 }
1705
1706 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1707 {
1708         pnfs_generic_write_commit_done(task, data);
1709 }
1710
1711 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1712 {
1713         struct nfs_commit_data *cdata = data;
1714
1715         ff_layout_commit_record_layoutstats_done(task, cdata);
1716         rpc_count_iostats_metrics(task,
1717             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1718 }
1719
1720 static void ff_layout_commit_release(void *data)
1721 {
1722         struct nfs_commit_data *cdata = data;
1723
1724         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1725         pnfs_generic_commit_release(data);
1726 }
1727
1728 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1729         .rpc_call_prepare = ff_layout_read_prepare_v3,
1730         .rpc_call_done = ff_layout_read_call_done,
1731         .rpc_count_stats = ff_layout_read_count_stats,
1732         .rpc_release = ff_layout_read_release,
1733 };
1734
1735 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1736         .rpc_call_prepare = ff_layout_read_prepare_v4,
1737         .rpc_call_done = ff_layout_read_call_done,
1738         .rpc_count_stats = ff_layout_read_count_stats,
1739         .rpc_release = ff_layout_read_release,
1740 };
1741
1742 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1743         .rpc_call_prepare = ff_layout_write_prepare_v3,
1744         .rpc_call_done = ff_layout_write_call_done,
1745         .rpc_count_stats = ff_layout_write_count_stats,
1746         .rpc_release = ff_layout_write_release,
1747 };
1748
1749 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1750         .rpc_call_prepare = ff_layout_write_prepare_v4,
1751         .rpc_call_done = ff_layout_write_call_done,
1752         .rpc_count_stats = ff_layout_write_count_stats,
1753         .rpc_release = ff_layout_write_release,
1754 };
1755
1756 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1757         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1758         .rpc_call_done = ff_layout_commit_done,
1759         .rpc_count_stats = ff_layout_commit_count_stats,
1760         .rpc_release = ff_layout_commit_release,
1761 };
1762
1763 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1764         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1765         .rpc_call_done = ff_layout_commit_done,
1766         .rpc_count_stats = ff_layout_commit_count_stats,
1767         .rpc_release = ff_layout_commit_release,
1768 };
1769
1770 static enum pnfs_try_status
1771 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1772 {
1773         struct pnfs_layout_segment *lseg = hdr->lseg;
1774         struct nfs4_pnfs_ds *ds;
1775         struct rpc_clnt *ds_clnt;
1776         struct nfs4_ff_layout_mirror *mirror;
1777         const struct cred *ds_cred;
1778         loff_t offset = hdr->args.offset;
1779         u32 idx = hdr->pgio_mirror_idx;
1780         int vers;
1781         struct nfs_fh *fh;
1782
1783         dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
1784                 __func__, hdr->inode->i_ino,
1785                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1786
1787         mirror = FF_LAYOUT_COMP(lseg, idx);
1788         ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false);
1789         if (!ds)
1790                 goto out_failed;
1791
1792         ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1793                                                    hdr->inode);
1794         if (IS_ERR(ds_clnt))
1795                 goto out_failed;
1796
1797         ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
1798         if (!ds_cred)
1799                 goto out_failed;
1800
1801         vers = nfs4_ff_layout_ds_version(mirror);
1802
1803         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1804                 ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers);
1805
1806         hdr->pgio_done_cb = ff_layout_read_done_cb;
1807         refcount_inc(&ds->ds_clp->cl_count);
1808         hdr->ds_clp = ds->ds_clp;
1809         fh = nfs4_ff_layout_select_ds_fh(mirror);
1810         if (fh)
1811                 hdr->args.fh = fh;
1812
1813         nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
1814
1815         /*
1816          * Note that if we ever decide to split across DSes,
1817          * then we may need to handle dense-like offsets.
1818          */
1819         hdr->args.offset = offset;
1820         hdr->mds_offset = offset;
1821
1822         /* Perform an asynchronous read to ds */
1823         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1824                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1825                                       &ff_layout_read_call_ops_v4,
1826                           0, RPC_TASK_SOFTCONN);
1827         put_cred(ds_cred);
1828         return PNFS_ATTEMPTED;
1829
1830 out_failed:
1831         if (ff_layout_avoid_mds_available_ds(lseg))
1832                 return PNFS_TRY_AGAIN;
1833         trace_pnfs_mds_fallback_read_pagelist(hdr->inode,
1834                         hdr->args.offset, hdr->args.count,
1835                         IOMODE_READ, NFS_I(hdr->inode)->layout, lseg);
1836         return PNFS_NOT_ATTEMPTED;
1837 }
1838
1839 /* Perform async writes. */
1840 static enum pnfs_try_status
1841 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1842 {
1843         struct pnfs_layout_segment *lseg = hdr->lseg;
1844         struct nfs4_pnfs_ds *ds;
1845         struct rpc_clnt *ds_clnt;
1846         struct nfs4_ff_layout_mirror *mirror;
1847         const struct cred *ds_cred;
1848         loff_t offset = hdr->args.offset;
1849         int vers;
1850         struct nfs_fh *fh;
1851         int idx = hdr->pgio_mirror_idx;
1852
1853         mirror = FF_LAYOUT_COMP(lseg, idx);
1854         ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
1855         if (!ds)
1856                 goto out_failed;
1857
1858         ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1859                                                    hdr->inode);
1860         if (IS_ERR(ds_clnt))
1861                 goto out_failed;
1862
1863         ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
1864         if (!ds_cred)
1865                 goto out_failed;
1866
1867         vers = nfs4_ff_layout_ds_version(mirror);
1868
1869         dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
1870                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1871                 offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count),
1872                 vers);
1873
1874         hdr->pgio_done_cb = ff_layout_write_done_cb;
1875         refcount_inc(&ds->ds_clp->cl_count);
1876         hdr->ds_clp = ds->ds_clp;
1877         hdr->ds_commit_idx = idx;
1878         fh = nfs4_ff_layout_select_ds_fh(mirror);
1879         if (fh)
1880                 hdr->args.fh = fh;
1881
1882         nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
1883
1884         /*
1885          * Note that if we ever decide to split across DSes,
1886          * then we may need to handle dense-like offsets.
1887          */
1888         hdr->args.offset = offset;
1889
1890         /* Perform an asynchronous write */
1891         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1892                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1893                                       &ff_layout_write_call_ops_v4,
1894                           sync, RPC_TASK_SOFTCONN);
1895         put_cred(ds_cred);
1896         return PNFS_ATTEMPTED;
1897
1898 out_failed:
1899         if (ff_layout_avoid_mds_available_ds(lseg))
1900                 return PNFS_TRY_AGAIN;
1901         trace_pnfs_mds_fallback_write_pagelist(hdr->inode,
1902                         hdr->args.offset, hdr->args.count,
1903                         IOMODE_RW, NFS_I(hdr->inode)->layout, lseg);
1904         return PNFS_NOT_ATTEMPTED;
1905 }
1906
1907 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1908 {
1909         return i;
1910 }
1911
1912 static struct nfs_fh *
1913 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1914 {
1915         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1916
1917         /* FIXME: Assume that there is only one NFS version available
1918          * for the DS.
1919          */
1920         return &flseg->mirror_array[i]->fh_versions[0];
1921 }
1922
1923 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1924 {
1925         struct pnfs_layout_segment *lseg = data->lseg;
1926         struct nfs4_pnfs_ds *ds;
1927         struct rpc_clnt *ds_clnt;
1928         struct nfs4_ff_layout_mirror *mirror;
1929         const struct cred *ds_cred;
1930         u32 idx;
1931         int vers, ret;
1932         struct nfs_fh *fh;
1933
1934         if (!lseg || !(pnfs_is_valid_lseg(lseg) ||
1935             test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags)))
1936                 goto out_err;
1937
1938         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1939         mirror = FF_LAYOUT_COMP(lseg, idx);
1940         ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
1941         if (!ds)
1942                 goto out_err;
1943
1944         ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1945                                                    data->inode);
1946         if (IS_ERR(ds_clnt))
1947                 goto out_err;
1948
1949         ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, data->cred);
1950         if (!ds_cred)
1951                 goto out_err;
1952
1953         vers = nfs4_ff_layout_ds_version(mirror);
1954
1955         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1956                 data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count),
1957                 vers);
1958         data->commit_done_cb = ff_layout_commit_done_cb;
1959         data->cred = ds_cred;
1960         refcount_inc(&ds->ds_clp->cl_count);
1961         data->ds_clp = ds->ds_clp;
1962         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1963         if (fh)
1964                 data->args.fh = fh;
1965
1966         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1967                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1968                                                &ff_layout_commit_call_ops_v4,
1969                                    how, RPC_TASK_SOFTCONN);
1970         put_cred(ds_cred);
1971         return ret;
1972 out_err:
1973         pnfs_generic_prepare_to_resend_writes(data);
1974         pnfs_generic_commit_release(data);
1975         return -EAGAIN;
1976 }
1977
1978 static int
1979 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1980                            int how, struct nfs_commit_info *cinfo)
1981 {
1982         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1983                                             ff_layout_initiate_commit);
1984 }
1985
1986 static struct pnfs_ds_commit_info *
1987 ff_layout_get_ds_info(struct inode *inode)
1988 {
1989         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1990
1991         if (layout == NULL)
1992                 return NULL;
1993
1994         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1995 }
1996
1997 static void
1998 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1999 {
2000         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
2001                                                   id_node));
2002 }
2003
2004 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
2005                                   const struct nfs4_layoutreturn_args *args,
2006                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
2007 {
2008         __be32 *start;
2009
2010         start = xdr_reserve_space(xdr, 4);
2011         if (unlikely(!start))
2012                 return -E2BIG;
2013
2014         *start = cpu_to_be32(ff_args->num_errors);
2015         /* This assume we always return _ALL_ layouts */
2016         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
2017 }
2018
2019 static void
2020 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
2021 {
2022         WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
2023 }
2024
2025 static void
2026 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
2027                             const nfs4_stateid *stateid,
2028                             const struct nfs42_layoutstat_devinfo *devinfo)
2029 {
2030         __be32 *p;
2031
2032         p = xdr_reserve_space(xdr, 8 + 8);
2033         p = xdr_encode_hyper(p, devinfo->offset);
2034         p = xdr_encode_hyper(p, devinfo->length);
2035         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
2036         p = xdr_reserve_space(xdr, 4*8);
2037         p = xdr_encode_hyper(p, devinfo->read_count);
2038         p = xdr_encode_hyper(p, devinfo->read_bytes);
2039         p = xdr_encode_hyper(p, devinfo->write_count);
2040         p = xdr_encode_hyper(p, devinfo->write_bytes);
2041         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
2042 }
2043
2044 static void
2045 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
2046                             const nfs4_stateid *stateid,
2047                             const struct nfs42_layoutstat_devinfo *devinfo)
2048 {
2049         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
2050         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
2051                         devinfo->ld_private.data);
2052 }
2053
2054 /* report nothing for now */
2055 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
2056                 const struct nfs4_layoutreturn_args *args,
2057                 struct nfs4_flexfile_layoutreturn_args *ff_args)
2058 {
2059         __be32 *p;
2060         int i;
2061
2062         p = xdr_reserve_space(xdr, 4);
2063         *p = cpu_to_be32(ff_args->num_dev);
2064         for (i = 0; i < ff_args->num_dev; i++)
2065                 ff_layout_encode_ff_iostat(xdr,
2066                                 &args->layout->plh_stateid,
2067                                 &ff_args->devinfo[i]);
2068 }
2069
2070 static void
2071 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2072                 unsigned int num_entries)
2073 {
2074         unsigned int i;
2075
2076         for (i = 0; i < num_entries; i++) {
2077                 if (!devinfo[i].ld_private.ops)
2078                         continue;
2079                 if (!devinfo[i].ld_private.ops->free)
2080                         continue;
2081                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2082         }
2083 }
2084
2085 static struct nfs4_deviceid_node *
2086 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2087                               struct pnfs_device *pdev, gfp_t gfp_flags)
2088 {
2089         struct nfs4_ff_layout_ds *dsaddr;
2090
2091         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2092         if (!dsaddr)
2093                 return NULL;
2094         return &dsaddr->id_node;
2095 }
2096
2097 static void
2098 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2099                 const void *voidargs,
2100                 const struct nfs4_xdr_opaque_data *ff_opaque)
2101 {
2102         const struct nfs4_layoutreturn_args *args = voidargs;
2103         struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2104         struct xdr_buf tmp_buf = {
2105                 .head = {
2106                         [0] = {
2107                                 .iov_base = page_address(ff_args->pages[0]),
2108                         },
2109                 },
2110                 .buflen = PAGE_SIZE,
2111         };
2112         struct xdr_stream tmp_xdr;
2113         __be32 *start;
2114
2115         dprintk("%s: Begin\n", __func__);
2116
2117         xdr_init_encode(&tmp_xdr, &tmp_buf, NULL, NULL);
2118
2119         ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2120         ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2121
2122         start = xdr_reserve_space(xdr, 4);
2123         *start = cpu_to_be32(tmp_buf.len);
2124         xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2125
2126         dprintk("%s: Return\n", __func__);
2127 }
2128
2129 static void
2130 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2131 {
2132         struct nfs4_flexfile_layoutreturn_args *ff_args;
2133
2134         if (!args->data)
2135                 return;
2136         ff_args = args->data;
2137         args->data = NULL;
2138
2139         ff_layout_free_ds_ioerr(&ff_args->errors);
2140         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2141
2142         put_page(ff_args->pages[0]);
2143         kfree(ff_args);
2144 }
2145
2146 static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2147         .encode = ff_layout_encode_layoutreturn,
2148         .free = ff_layout_free_layoutreturn,
2149 };
2150
2151 static int
2152 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2153 {
2154         struct nfs4_flexfile_layoutreturn_args *ff_args;
2155         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2156
2157         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2158         if (!ff_args)
2159                 goto out_nomem;
2160         ff_args->pages[0] = alloc_page(GFP_KERNEL);
2161         if (!ff_args->pages[0])
2162                 goto out_nomem_free;
2163
2164         INIT_LIST_HEAD(&ff_args->errors);
2165         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2166                         &args->range, &ff_args->errors,
2167                         FF_LAYOUTRETURN_MAXERR);
2168
2169         spin_lock(&args->inode->i_lock);
2170         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2171                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2172         spin_unlock(&args->inode->i_lock);
2173
2174         args->ld_private->ops = &layoutreturn_ops;
2175         args->ld_private->data = ff_args;
2176         return 0;
2177 out_nomem_free:
2178         kfree(ff_args);
2179 out_nomem:
2180         return -ENOMEM;
2181 }
2182
2183 #ifdef CONFIG_NFS_V4_2
2184 void
2185 ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
2186 {
2187         struct pnfs_layout_hdr *lo = lseg->pls_layout;
2188         struct nfs42_layout_error *errors;
2189         LIST_HEAD(head);
2190
2191         if (!nfs_server_capable(lo->plh_inode, NFS_CAP_LAYOUTERROR))
2192                 return;
2193         ff_layout_fetch_ds_ioerr(lo, &lseg->pls_range, &head, -1);
2194         if (list_empty(&head))
2195                 return;
2196
2197         errors = kmalloc_array(NFS42_LAYOUTERROR_MAX,
2198                         sizeof(*errors), GFP_NOFS);
2199         if (errors != NULL) {
2200                 const struct nfs4_ff_layout_ds_err *pos;
2201                 size_t n = 0;
2202
2203                 list_for_each_entry(pos, &head, list) {
2204                         errors[n].offset = pos->offset;
2205                         errors[n].length = pos->length;
2206                         nfs4_stateid_copy(&errors[n].stateid, &pos->stateid);
2207                         errors[n].errors[0].dev_id = pos->deviceid;
2208                         errors[n].errors[0].status = pos->status;
2209                         errors[n].errors[0].opnum = pos->opnum;
2210                         n++;
2211                         if (!list_is_last(&pos->list, &head) &&
2212                             n < NFS42_LAYOUTERROR_MAX)
2213                                 continue;
2214                         if (nfs42_proc_layouterror(lseg, errors, n) < 0)
2215                                 break;
2216                         n = 0;
2217                 }
2218                 kfree(errors);
2219         }
2220         ff_layout_free_ds_ioerr(&head);
2221 }
2222 #else
2223 void
2224 ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
2225 {
2226 }
2227 #endif
2228
2229 static int
2230 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2231 {
2232         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2233
2234         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2235 }
2236
2237 static size_t
2238 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2239                           const int buflen)
2240 {
2241         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2242         const struct in6_addr *addr = &sin6->sin6_addr;
2243
2244         /*
2245          * RFC 4291, Section 2.2.2
2246          *
2247          * Shorthanded ANY address
2248          */
2249         if (ipv6_addr_any(addr))
2250                 return snprintf(buf, buflen, "::");
2251
2252         /*
2253          * RFC 4291, Section 2.2.2
2254          *
2255          * Shorthanded loopback address
2256          */
2257         if (ipv6_addr_loopback(addr))
2258                 return snprintf(buf, buflen, "::1");
2259
2260         /*
2261          * RFC 4291, Section 2.2.3
2262          *
2263          * Special presentation address format for mapped v4
2264          * addresses.
2265          */
2266         if (ipv6_addr_v4mapped(addr))
2267                 return snprintf(buf, buflen, "::ffff:%pI4",
2268                                         &addr->s6_addr32[3]);
2269
2270         /*
2271          * RFC 4291, Section 2.2.1
2272          */
2273         return snprintf(buf, buflen, "%pI6c", addr);
2274 }
2275
2276 /* Derived from rpc_sockaddr2uaddr */
2277 static void
2278 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2279 {
2280         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2281         char portbuf[RPCBIND_MAXUADDRPLEN];
2282         char addrbuf[RPCBIND_MAXUADDRLEN];
2283         char *netid;
2284         unsigned short port;
2285         int len, netid_len;
2286         __be32 *p;
2287
2288         switch (sap->sa_family) {
2289         case AF_INET:
2290                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2291                         return;
2292                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2293                 netid = "tcp";
2294                 netid_len = 3;
2295                 break;
2296         case AF_INET6:
2297                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2298                         return;
2299                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2300                 netid = "tcp6";
2301                 netid_len = 4;
2302                 break;
2303         default:
2304                 /* we only support tcp and tcp6 */
2305                 WARN_ON_ONCE(1);
2306                 return;
2307         }
2308
2309         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2310         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2311
2312         p = xdr_reserve_space(xdr, 4 + netid_len);
2313         xdr_encode_opaque(p, netid, netid_len);
2314
2315         p = xdr_reserve_space(xdr, 4 + len);
2316         xdr_encode_opaque(p, addrbuf, len);
2317 }
2318
2319 static void
2320 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2321                          ktime_t t)
2322 {
2323         struct timespec64 ts;
2324         __be32 *p;
2325
2326         p = xdr_reserve_space(xdr, 12);
2327         ts = ktime_to_timespec64(t);
2328         p = xdr_encode_hyper(p, ts.tv_sec);
2329         *p++ = cpu_to_be32(ts.tv_nsec);
2330 }
2331
2332 static void
2333 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2334                             struct nfs4_ff_io_stat *stat)
2335 {
2336         __be32 *p;
2337
2338         p = xdr_reserve_space(xdr, 5 * 8);
2339         p = xdr_encode_hyper(p, stat->ops_requested);
2340         p = xdr_encode_hyper(p, stat->bytes_requested);
2341         p = xdr_encode_hyper(p, stat->ops_completed);
2342         p = xdr_encode_hyper(p, stat->bytes_completed);
2343         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2344         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2345         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2346 }
2347
2348 static void
2349 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2350                               const struct nfs42_layoutstat_devinfo *devinfo,
2351                               struct nfs4_ff_layout_mirror *mirror)
2352 {
2353         struct nfs4_pnfs_ds_addr *da;
2354         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2355         struct nfs_fh *fh = &mirror->fh_versions[0];
2356         __be32 *p;
2357
2358         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2359         dprintk("%s: DS %s: encoding address %s\n",
2360                 __func__, ds->ds_remotestr, da->da_remotestr);
2361         /* netaddr4 */
2362         ff_layout_encode_netaddr(xdr, da);
2363         /* nfs_fh4 */
2364         p = xdr_reserve_space(xdr, 4 + fh->size);
2365         xdr_encode_opaque(p, fh->data, fh->size);
2366         /* ff_io_latency4 read */
2367         spin_lock(&mirror->lock);
2368         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2369         /* ff_io_latency4 write */
2370         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2371         spin_unlock(&mirror->lock);
2372         /* nfstime4 */
2373         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2374         /* bool */
2375         p = xdr_reserve_space(xdr, 4);
2376         *p = cpu_to_be32(false);
2377 }
2378
2379 static void
2380 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2381                              const struct nfs4_xdr_opaque_data *opaque)
2382 {
2383         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2384                         struct nfs42_layoutstat_devinfo, ld_private);
2385         __be32 *start;
2386
2387         /* layoutupdate length */
2388         start = xdr_reserve_space(xdr, 4);
2389         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2390
2391         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2392 }
2393
2394 static void
2395 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2396 {
2397         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2398
2399         ff_layout_put_mirror(mirror);
2400 }
2401
2402 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2403         .encode = ff_layout_encode_layoutstats,
2404         .free   = ff_layout_free_layoutstats,
2405 };
2406
2407 static int
2408 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2409                                struct nfs42_layoutstat_devinfo *devinfo,
2410                                int dev_limit)
2411 {
2412         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2413         struct nfs4_ff_layout_mirror *mirror;
2414         struct nfs4_deviceid_node *dev;
2415         int i = 0;
2416
2417         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2418                 if (i >= dev_limit)
2419                         break;
2420                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2421                         continue;
2422                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2423                         continue;
2424                 /* mirror refcount put in cleanup_layoutstats */
2425                 if (!refcount_inc_not_zero(&mirror->ref))
2426                         continue;
2427                 dev = &mirror->mirror_ds->id_node;
2428                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2429                 devinfo->offset = 0;
2430                 devinfo->length = NFS4_MAX_UINT64;
2431                 spin_lock(&mirror->lock);
2432                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2433                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2434                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2435                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2436                 spin_unlock(&mirror->lock);
2437                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2438                 devinfo->ld_private.ops = &layoutstat_ops;
2439                 devinfo->ld_private.data = mirror;
2440
2441                 devinfo++;
2442                 i++;
2443         }
2444         return i;
2445 }
2446
2447 static int
2448 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2449 {
2450         struct nfs4_flexfile_layout *ff_layout;
2451         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2452
2453         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2454         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2455         if (!args->devinfo)
2456                 return -ENOMEM;
2457
2458         spin_lock(&args->inode->i_lock);
2459         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2460         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2461                         &args->devinfo[0], dev_count);
2462         spin_unlock(&args->inode->i_lock);
2463         if (!args->num_dev) {
2464                 kfree(args->devinfo);
2465                 args->devinfo = NULL;
2466                 return -ENOENT;
2467         }
2468
2469         return 0;
2470 }
2471
2472 static int
2473 ff_layout_set_layoutdriver(struct nfs_server *server,
2474                 const struct nfs_fh *dummy)
2475 {
2476 #if IS_ENABLED(CONFIG_NFS_V4_2)
2477         server->caps |= NFS_CAP_LAYOUTSTATS;
2478 #endif
2479         return 0;
2480 }
2481
2482 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2483         .id                     = LAYOUT_FLEX_FILES,
2484         .name                   = "LAYOUT_FLEX_FILES",
2485         .owner                  = THIS_MODULE,
2486         .flags                  = PNFS_LAYOUTGET_ON_OPEN,
2487         .max_layoutget_response = 4096, /* 1 page or so... */
2488         .set_layoutdriver       = ff_layout_set_layoutdriver,
2489         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2490         .free_layout_hdr        = ff_layout_free_layout_hdr,
2491         .alloc_lseg             = ff_layout_alloc_lseg,
2492         .free_lseg              = ff_layout_free_lseg,
2493         .add_lseg               = ff_layout_add_lseg,
2494         .pg_read_ops            = &ff_layout_pg_read_ops,
2495         .pg_write_ops           = &ff_layout_pg_write_ops,
2496         .get_ds_info            = ff_layout_get_ds_info,
2497         .free_deviceid_node     = ff_layout_free_deviceid_node,
2498         .mark_request_commit    = pnfs_layout_mark_request_commit,
2499         .clear_request_commit   = pnfs_generic_clear_request_commit,
2500         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2501         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2502         .commit_pagelist        = ff_layout_commit_pagelist,
2503         .read_pagelist          = ff_layout_read_pagelist,
2504         .write_pagelist         = ff_layout_write_pagelist,
2505         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2506         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2507         .sync                   = pnfs_nfs_generic_sync,
2508         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2509 };
2510
2511 static int __init nfs4flexfilelayout_init(void)
2512 {
2513         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2514                __func__);
2515         return pnfs_register_layoutdriver(&flexfilelayout_type);
2516 }
2517
2518 static void __exit nfs4flexfilelayout_exit(void)
2519 {
2520         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2521                __func__);
2522         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2523 }
2524
2525 MODULE_ALIAS("nfs-layouttype4-4");
2526
2527 MODULE_LICENSE("GPL");
2528 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2529
2530 module_init(nfs4flexfilelayout_init);
2531 module_exit(nfs4flexfilelayout_exit);
2532
2533 module_param(io_maxretrans, ushort, 0644);
2534 MODULE_PARM_DESC(io_maxretrans, "The  number of times the NFSv4.1 client "
2535                         "retries an I/O request before returning an error. ");