linux/fs/nfs/flexfilelayout/flexfilelayout.c
<<
>>
Prefs
   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_mount.h>
  12#include <linux/nfs_page.h>
  13#include <linux/module.h>
  14#include <linux/sched/mm.h>
  15
  16#include <linux/sunrpc/metrics.h>
  17
  18#include "flexfilelayout.h"
  19#include "../nfs4session.h"
  20#include "../nfs4idmap.h"
  21#include "../internal.h"
  22#include "../delegation.h"
  23#include "../nfs4trace.h"
  24#include "../iostat.h"
  25#include "../nfs.h"
  26#include "../nfs42.h"
  27
  28#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  29
  30#define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)
  31#define FF_LAYOUTRETURN_MAXERR 20
  32
  33static unsigned short io_maxretrans;
  34
  35static const struct pnfs_commit_ops ff_layout_commit_ops;
  36static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
  37                struct nfs_pgio_header *hdr);
  38static int ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
  39                               struct nfs42_layoutstat_devinfo *devinfo,
  40                               int dev_limit);
  41static void ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
  42                              const struct nfs42_layoutstat_devinfo *devinfo,
  43                              struct nfs4_ff_layout_mirror *mirror);
  44
  45static struct pnfs_layout_hdr *
  46ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
  47{
  48        struct nfs4_flexfile_layout *ffl;
  49
  50        ffl = kzalloc(sizeof(*ffl), gfp_flags);
  51        if (ffl) {
  52                pnfs_init_ds_commit_info(&ffl->commit_info);
  53                INIT_LIST_HEAD(&ffl->error_list);
  54                INIT_LIST_HEAD(&ffl->mirrors);
  55                ffl->last_report_time = ktime_get();
  56                ffl->commit_info.ops = &ff_layout_commit_ops;
  57                return &ffl->generic_hdr;
  58        } else
  59                return NULL;
  60}
  61
  62static void
  63ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
  64{
  65        struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(lo);
  66        struct nfs4_ff_layout_ds_err *err, *n;
  67
  68        list_for_each_entry_safe(err, n, &ffl->error_list, list) {
  69                list_del(&err->list);
  70                kfree(err);
  71        }
  72        kfree_rcu(ffl, generic_hdr.plh_rcu);
  73}
  74
  75static int decode_pnfs_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
  76{
  77        __be32 *p;
  78
  79        p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
  80        if (unlikely(p == NULL))
  81                return -ENOBUFS;
  82        stateid->type = NFS4_PNFS_DS_STATEID_TYPE;
  83        memcpy(stateid->data, p, NFS4_STATEID_SIZE);
  84        dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
  85                p[0], p[1], p[2], p[3]);
  86        return 0;
  87}
  88
  89static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
  90{
  91        __be32 *p;
  92
  93        p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
  94        if (unlikely(!p))
  95                return -ENOBUFS;
  96        memcpy(devid, p, NFS4_DEVICEID4_SIZE);
  97        nfs4_print_deviceid(devid);
  98        return 0;
  99}
 100
 101static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
 102{
 103        __be32 *p;
 104
 105        p = xdr_inline_decode(xdr, 4);
 106        if (unlikely(!p))
 107                return -ENOBUFS;
 108        fh->size = be32_to_cpup(p++);
 109        if (fh->size > sizeof(struct nfs_fh)) {
 110                printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
 111                       fh->size);
 112                return -EOVERFLOW;
 113        }
 114        /* fh.data */
 115        p = xdr_inline_decode(xdr, fh->size);
 116        if (unlikely(!p))
 117                return -ENOBUFS;
 118        memcpy(&fh->data, p, fh->size);
 119        dprintk("%s: fh len %d\n", __func__, fh->size);
 120
 121        return 0;
 122}
 123
 124/*
 125 * Currently only stringified uids and gids are accepted.
 126 * I.e., kerberos is not supported to the DSes, so no pricipals.
 127 *
 128 * That means that one common function will suffice, but when
 129 * principals are added, this should be split to accomodate
 130 * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
 131 */
 132static int
 133decode_name(struct xdr_stream *xdr, u32 *id)
 134{
 135        __be32 *p;
 136        int len;
 137
 138        /* opaque_length(4)*/
 139        p = xdr_inline_decode(xdr, 4);
 140        if (unlikely(!p))
 141                return -ENOBUFS;
 142        len = be32_to_cpup(p++);
 143        if (len < 0)
 144                return -EINVAL;
 145
 146        dprintk("%s: len %u\n", __func__, len);
 147
 148        /* opaque body */
 149        p = xdr_inline_decode(xdr, len);
 150        if (unlikely(!p))
 151                return -ENOBUFS;
 152
 153        if (!nfs_map_string_to_numeric((char *)p, len, id))
 154                return -EINVAL;
 155
 156        return 0;
 157}
 158
 159static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
 160                const struct nfs4_ff_layout_mirror *m2)
 161{
 162        int i, j;
 163
 164        if (m1->fh_versions_cnt != m2->fh_versions_cnt)
 165                return false;
 166        for (i = 0; i < m1->fh_versions_cnt; i++) {
 167                bool found_fh = false;
 168                for (j = 0; j < m2->fh_versions_cnt; j++) {
 169                        if (nfs_compare_fh(&m1->fh_versions[i],
 170                                        &m2->fh_versions[j]) == 0) {
 171                                found_fh = true;
 172                                break;
 173                        }
 174                }
 175                if (!found_fh)
 176                        return false;
 177        }
 178        return true;
 179}
 180
 181static struct nfs4_ff_layout_mirror *
 182ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
 183                struct nfs4_ff_layout_mirror *mirror)
 184{
 185        struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
 186        struct nfs4_ff_layout_mirror *pos;
 187        struct inode *inode = lo->plh_inode;
 188
 189        spin_lock(&inode->i_lock);
 190        list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
 191                if (memcmp(&mirror->devid, &pos->devid, sizeof(pos->devid)) != 0)
 192                        continue;
 193                if (!ff_mirror_match_fh(mirror, pos))
 194                        continue;
 195                if (refcount_inc_not_zero(&pos->ref)) {
 196                        spin_unlock(&inode->i_lock);
 197                        return pos;
 198                }
 199        }
 200        list_add(&mirror->mirrors, &ff_layout->mirrors);
 201        mirror->layout = lo;
 202        spin_unlock(&inode->i_lock);
 203        return mirror;
 204}
 205
 206static void
 207ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
 208{
 209        struct inode *inode;
 210        if (mirror->layout == NULL)
 211                return;
 212        inode = mirror->layout->plh_inode;
 213        spin_lock(&inode->i_lock);
 214        list_del(&mirror->mirrors);
 215        spin_unlock(&inode->i_lock);
 216        mirror->layout = NULL;
 217}
 218
 219static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
 220{
 221        struct nfs4_ff_layout_mirror *mirror;
 222
 223        mirror = kzalloc(sizeof(*mirror), gfp_flags);
 224        if (mirror != NULL) {
 225                spin_lock_init(&mirror->lock);
 226                refcount_set(&mirror->ref, 1);
 227                INIT_LIST_HEAD(&mirror->mirrors);
 228        }
 229        return mirror;
 230}
 231
 232static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
 233{
 234        const struct cred       *cred;
 235
 236        ff_layout_remove_mirror(mirror);
 237        kfree(mirror->fh_versions);
 238        cred = rcu_access_pointer(mirror->ro_cred);
 239        put_cred(cred);
 240        cred = rcu_access_pointer(mirror->rw_cred);
 241        put_cred(cred);
 242        nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
 243        kfree(mirror);
 244}
 245
 246static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
 247{
 248        if (mirror != NULL && refcount_dec_and_test(&mirror->ref))
 249                ff_layout_free_mirror(mirror);
 250}
 251
 252static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
 253{
 254        u32 i;
 255
 256        for (i = 0; i < fls->mirror_array_cnt; i++)
 257                ff_layout_put_mirror(fls->mirror_array[i]);
 258}
 259
 260static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
 261{
 262        if (fls) {
 263                ff_layout_free_mirror_array(fls);
 264                kfree(fls);
 265        }
 266}
 267
 268static bool
 269ff_lseg_match_mirrors(struct pnfs_layout_segment *l1,
 270                struct pnfs_layout_segment *l2)
 271{
 272        const struct nfs4_ff_layout_segment *fl1 = FF_LAYOUT_LSEG(l1);
 273        const struct nfs4_ff_layout_segment *fl2 = FF_LAYOUT_LSEG(l1);
 274        u32 i;
 275
 276        if (fl1->mirror_array_cnt != fl2->mirror_array_cnt)
 277                return false;
 278        for (i = 0; i < fl1->mirror_array_cnt; i++) {
 279                if (fl1->mirror_array[i] != fl2->mirror_array[i])
 280                        return false;
 281        }
 282        return true;
 283}
 284
 285static bool
 286ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
 287                const struct pnfs_layout_range *l2)
 288{
 289        u64 end1, end2;
 290
 291        if (l1->iomode != l2->iomode)
 292                return l1->iomode != IOMODE_READ;
 293        end1 = pnfs_calc_offset_end(l1->offset, l1->length);
 294        end2 = pnfs_calc_offset_end(l2->offset, l2->length);
 295        if (end1 < l2->offset)
 296                return false;
 297        if (end2 < l1->offset)
 298                return true;
 299        return l2->offset <= l1->offset;
 300}
 301
 302static bool
 303ff_lseg_merge(struct pnfs_layout_segment *new,
 304                struct pnfs_layout_segment *old)
 305{
 306        u64 new_end, old_end;
 307
 308        if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
 309                return false;
 310        if (new->pls_range.iomode != old->pls_range.iomode)
 311                return false;
 312        old_end = pnfs_calc_offset_end(old->pls_range.offset,
 313                        old->pls_range.length);
 314        if (old_end < new->pls_range.offset)
 315                return false;
 316        new_end = pnfs_calc_offset_end(new->pls_range.offset,
 317                        new->pls_range.length);
 318        if (new_end < old->pls_range.offset)
 319                return false;
 320        if (!ff_lseg_match_mirrors(new, old))
 321                return false;
 322
 323        /* Mergeable: copy info from 'old' to 'new' */
 324        if (new_end < old_end)
 325                new_end = old_end;
 326        if (new->pls_range.offset < old->pls_range.offset)
 327                new->pls_range.offset = old->pls_range.offset;
 328        new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
 329                        new_end);
 330        if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
 331                set_bit(NFS_LSEG_ROC, &new->pls_flags);
 332        return true;
 333}
 334
 335static void
 336ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
 337                struct pnfs_layout_segment *lseg,
 338                struct list_head *free_me)
 339{
 340        pnfs_generic_layout_insert_lseg(lo, lseg,
 341                        ff_lseg_range_is_after,
 342                        ff_lseg_merge,
 343                        free_me);
 344}
 345
 346static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
 347{
 348        int i, j;
 349
 350        for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
 351                for (j = i + 1; j < fls->mirror_array_cnt; j++)
 352                        if (fls->mirror_array[i]->efficiency <
 353                            fls->mirror_array[j]->efficiency)
 354                                swap(fls->mirror_array[i],
 355                                     fls->mirror_array[j]);
 356        }
 357}
 358
 359static struct pnfs_layout_segment *
 360ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 361                     struct nfs4_layoutget_res *lgr,
 362                     gfp_t gfp_flags)
 363{
 364        struct pnfs_layout_segment *ret;
 365        struct nfs4_ff_layout_segment *fls = NULL;
 366        struct xdr_stream stream;
 367        struct xdr_buf buf;
 368        struct page *scratch;
 369        u64 stripe_unit;
 370        u32 mirror_array_cnt;
 371        __be32 *p;
 372        int i, rc;
 373
 374        dprintk("--> %s\n", __func__);
 375        scratch = alloc_page(gfp_flags);
 376        if (!scratch)
 377                return ERR_PTR(-ENOMEM);
 378
 379        xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
 380                              lgr->layoutp->len);
 381        xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 382
 383        /* stripe unit and mirror_array_cnt */
 384        rc = -EIO;
 385        p = xdr_inline_decode(&stream, 8 + 4);
 386        if (!p)
 387                goto out_err_free;
 388
 389        p = xdr_decode_hyper(p, &stripe_unit);
 390        mirror_array_cnt = be32_to_cpup(p++);
 391        dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
 392                stripe_unit, mirror_array_cnt);
 393
 394        if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
 395            mirror_array_cnt == 0)
 396                goto out_err_free;
 397
 398        rc = -ENOMEM;
 399        fls = kzalloc(struct_size(fls, mirror_array, mirror_array_cnt),
 400                        gfp_flags);
 401        if (!fls)
 402                goto out_err_free;
 403
 404        fls->mirror_array_cnt = mirror_array_cnt;
 405        fls->stripe_unit = stripe_unit;
 406
 407        for (i = 0; i < fls->mirror_array_cnt; i++) {
 408                struct nfs4_ff_layout_mirror *mirror;
 409                struct cred *kcred;
 410                const struct cred __rcu *cred;
 411                kuid_t uid;
 412                kgid_t gid;
 413                u32 ds_count, fh_count, id;
 414                int j;
 415
 416                rc = -EIO;
 417                p = xdr_inline_decode(&stream, 4);
 418                if (!p)
 419                        goto out_err_free;
 420                ds_count = be32_to_cpup(p);
 421
 422                /* FIXME: allow for striping? */
 423                if (ds_count != 1)
 424                        goto out_err_free;
 425
 426                fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
 427                if (fls->mirror_array[i] == NULL) {
 428                        rc = -ENOMEM;
 429                        goto out_err_free;
 430                }
 431
 432                fls->mirror_array[i]->ds_count = ds_count;
 433
 434                /* deviceid */
 435                rc = decode_deviceid(&stream, &fls->mirror_array[i]->devid);
 436                if (rc)
 437                        goto out_err_free;
 438
 439                /* efficiency */
 440                rc = -EIO;
 441                p = xdr_inline_decode(&stream, 4);
 442                if (!p)
 443                        goto out_err_free;
 444                fls->mirror_array[i]->efficiency = be32_to_cpup(p);
 445
 446                /* stateid */
 447                rc = decode_pnfs_stateid(&stream, &fls->mirror_array[i]->stateid);
 448                if (rc)
 449                        goto out_err_free;
 450
 451                /* fh */
 452                rc = -EIO;
 453                p = xdr_inline_decode(&stream, 4);
 454                if (!p)
 455                        goto out_err_free;
 456                fh_count = be32_to_cpup(p);
 457
 458                fls->mirror_array[i]->fh_versions =
 459                        kcalloc(fh_count, sizeof(struct nfs_fh),
 460                                gfp_flags);
 461                if (fls->mirror_array[i]->fh_versions == NULL) {
 462                        rc = -ENOMEM;
 463                        goto out_err_free;
 464                }
 465
 466                for (j = 0; j < fh_count; j++) {
 467                        rc = decode_nfs_fh(&stream,
 468                                           &fls->mirror_array[i]->fh_versions[j]);
 469                        if (rc)
 470                                goto out_err_free;
 471                }
 472
 473                fls->mirror_array[i]->fh_versions_cnt = fh_count;
 474
 475                /* user */
 476                rc = decode_name(&stream, &id);
 477                if (rc)
 478                        goto out_err_free;
 479
 480                uid = make_kuid(&init_user_ns, id);
 481
 482                /* group */
 483                rc = decode_name(&stream, &id);
 484                if (rc)
 485                        goto out_err_free;
 486
 487                gid = make_kgid(&init_user_ns, id);
 488
 489                if (gfp_flags & __GFP_FS)
 490                        kcred = prepare_kernel_cred(NULL);
 491                else {
 492                        unsigned int nofs_flags = memalloc_nofs_save();
 493                        kcred = prepare_kernel_cred(NULL);
 494                        memalloc_nofs_restore(nofs_flags);
 495                }
 496                rc = -ENOMEM;
 497                if (!kcred)
 498                        goto out_err_free;
 499                kcred->fsuid = uid;
 500                kcred->fsgid = gid;
 501                cred = RCU_INITIALIZER(kcred);
 502
 503                if (lgr->range.iomode == IOMODE_READ)
 504                        rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 505                else
 506                        rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 507
 508                mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
 509                if (mirror != fls->mirror_array[i]) {
 510                        /* swap cred ptrs so free_mirror will clean up old */
 511                        if (lgr->range.iomode == IOMODE_READ) {
 512                                cred = xchg(&mirror->ro_cred, cred);
 513                                rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 514                        } else {
 515                                cred = xchg(&mirror->rw_cred, cred);
 516                                rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 517                        }
 518                        ff_layout_free_mirror(fls->mirror_array[i]);
 519                        fls->mirror_array[i] = mirror;
 520                }
 521
 522                dprintk("%s: iomode %s uid %u gid %u\n", __func__,
 523                        lgr->range.iomode == IOMODE_READ ? "READ" : "RW",
 524                        from_kuid(&init_user_ns, uid),
 525                        from_kgid(&init_user_ns, gid));
 526        }
 527
 528        p = xdr_inline_decode(&stream, 4);
 529        if (!p)
 530                goto out_sort_mirrors;
 531        fls->flags = be32_to_cpup(p);
 532
 533        p = xdr_inline_decode(&stream, 4);
 534        if (!p)
 535                goto out_sort_mirrors;
 536        for (i=0; i < fls->mirror_array_cnt; i++)
 537                fls->mirror_array[i]->report_interval = be32_to_cpup(p);
 538
 539out_sort_mirrors:
 540        ff_layout_sort_mirrors(fls);
 541        ret = &fls->generic_hdr;
 542        dprintk("<-- %s (success)\n", __func__);
 543out_free_page:
 544        __free_page(scratch);
 545        return ret;
 546out_err_free:
 547        _ff_layout_free_lseg(fls);
 548        ret = ERR_PTR(rc);
 549        dprintk("<-- %s (%d)\n", __func__, rc);
 550        goto out_free_page;
 551}
 552
 553static void
 554ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
 555{
 556        struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 557
 558        dprintk("--> %s\n", __func__);
 559
 560        if (lseg->pls_range.iomode == IOMODE_RW) {
 561                struct nfs4_flexfile_layout *ffl;
 562                struct inode *inode;
 563
 564                ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
 565                inode = ffl->generic_hdr.plh_inode;
 566                spin_lock(&inode->i_lock);
 567                pnfs_generic_ds_cinfo_release_lseg(&ffl->commit_info, lseg);
 568                spin_unlock(&inode->i_lock);
 569        }
 570        _ff_layout_free_lseg(fls);
 571}
 572
 573static void
 574nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 575{
 576        /* first IO request? */
 577        if (atomic_inc_return(&timer->n_ops) == 1) {
 578                timer->start_time = now;
 579        }
 580}
 581
 582static ktime_t
 583nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 584{
 585        ktime_t start;
 586
 587        if (atomic_dec_return(&timer->n_ops) < 0)
 588                WARN_ON_ONCE(1);
 589
 590        start = timer->start_time;
 591        timer->start_time = now;
 592        return ktime_sub(now, start);
 593}
 594
 595static bool
 596nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
 597                            struct nfs4_ff_layoutstat *layoutstat,
 598                            ktime_t now)
 599{
 600        s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
 601        struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(mirror->layout);
 602
 603        nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
 604        if (!mirror->start_time)
 605                mirror->start_time = now;
 606        if (mirror->report_interval != 0)
 607                report_interval = (s64)mirror->report_interval * 1000LL;
 608        else if (layoutstats_timer != 0)
 609                report_interval = (s64)layoutstats_timer * 1000LL;
 610        if (ktime_to_ms(ktime_sub(now, ffl->last_report_time)) >=
 611                        report_interval) {
 612                ffl->last_report_time = now;
 613                return true;
 614        }
 615
 616        return false;
 617}
 618
 619static void
 620nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
 621                __u64 requested)
 622{
 623        struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 624
 625        iostat->ops_requested++;
 626        iostat->bytes_requested += requested;
 627}
 628
 629static void
 630nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
 631                __u64 requested,
 632                __u64 completed,
 633                ktime_t time_completed,
 634                ktime_t time_started)
 635{
 636        struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 637        ktime_t completion_time = ktime_sub(time_completed, time_started);
 638        ktime_t timer;
 639
 640        iostat->ops_completed++;
 641        iostat->bytes_completed += completed;
 642        iostat->bytes_not_delivered += requested - completed;
 643
 644        timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
 645        iostat->total_busy_time =
 646                        ktime_add(iostat->total_busy_time, timer);
 647        iostat->aggregate_completion_time =
 648                        ktime_add(iostat->aggregate_completion_time,
 649                                        completion_time);
 650}
 651
 652static void
 653nfs4_ff_layout_stat_io_start_read(struct inode *inode,
 654                struct nfs4_ff_layout_mirror *mirror,
 655                __u64 requested, ktime_t now)
 656{
 657        bool report;
 658
 659        spin_lock(&mirror->lock);
 660        report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
 661        nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
 662        set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 663        spin_unlock(&mirror->lock);
 664
 665        if (report)
 666                pnfs_report_layoutstat(inode, GFP_KERNEL);
 667}
 668
 669static void
 670nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
 671                struct nfs4_ff_layout_mirror *mirror,
 672                __u64 requested,
 673                __u64 completed)
 674{
 675        spin_lock(&mirror->lock);
 676        nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
 677                        requested, completed,
 678                        ktime_get(), task->tk_start);
 679        set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 680        spin_unlock(&mirror->lock);
 681}
 682
 683static void
 684nfs4_ff_layout_stat_io_start_write(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->write_stat, now);
 692        nfs4_ff_layout_stat_io_update_requested(&mirror->write_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_NOIO);
 698}
 699
 700static void
 701nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
 702                struct nfs4_ff_layout_mirror *mirror,
 703                __u64 requested,
 704                __u64 completed,
 705                enum nfs3_stable_how committed)
 706{
 707        if (committed == NFS_UNSTABLE)
 708                requested = completed = 0;
 709
 710        spin_lock(&mirror->lock);
 711        nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
 712                        requested, completed, ktime_get(), task->tk_start);
 713        set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 714        spin_unlock(&mirror->lock);
 715}
 716
 717static void
 718ff_layout_mark_ds_unreachable(struct pnfs_layout_segment *lseg, int idx)
 719{
 720        struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 721
 722        if (devid)
 723                nfs4_mark_deviceid_unavailable(devid);
 724}
 725
 726static void
 727ff_layout_mark_ds_reachable(struct pnfs_layout_segment *lseg, int idx)
 728{
 729        struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 730
 731        if (devid)
 732                nfs4_mark_deviceid_available(devid);
 733}
 734
 735static struct nfs4_pnfs_ds *
 736ff_layout_choose_ds_for_read(struct pnfs_layout_segment *lseg,
 737                             int start_idx, int *best_idx,
 738                             bool check_device)
 739{
 740        struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 741        struct nfs4_ff_layout_mirror *mirror;
 742        struct nfs4_pnfs_ds *ds;
 743        bool fail_return = false;
 744        int idx;
 745
 746        /* mirrors are initially sorted by efficiency */
 747        for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
 748                if (idx+1 == fls->mirror_array_cnt)
 749                        fail_return = !check_device;
 750
 751                mirror = FF_LAYOUT_COMP(lseg, idx);
 752                ds = nfs4_ff_layout_prepare_ds(lseg, mirror, fail_return);
 753                if (!ds)
 754                        continue;
 755
 756                if (check_device &&
 757                    nfs4_test_deviceid_unavailable(&mirror->mirror_ds->id_node))
 758                        continue;
 759
 760                *best_idx = idx;
 761                return ds;
 762        }
 763
 764        return NULL;
 765}
 766
 767static struct nfs4_pnfs_ds *
 768ff_layout_choose_any_ds_for_read(struct pnfs_layout_segment *lseg,
 769                                 int start_idx, int *best_idx)
 770{
 771        return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, false);
 772}
 773
 774static struct nfs4_pnfs_ds *
 775ff_layout_choose_valid_ds_for_read(struct pnfs_layout_segment *lseg,
 776                                   int start_idx, int *best_idx)
 777{
 778        return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, true);
 779}
 780
 781static struct nfs4_pnfs_ds *
 782ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
 783                                  int start_idx, int *best_idx)
 784{
 785        struct nfs4_pnfs_ds *ds;
 786
 787        ds = ff_layout_choose_valid_ds_for_read(lseg, start_idx, best_idx);
 788        if (ds)
 789                return ds;
 790        return ff_layout_choose_any_ds_for_read(lseg, start_idx, best_idx);
 791}
 792
 793static void
 794ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
 795                      struct nfs_page *req,
 796                      bool strict_iomode)
 797{
 798        pnfs_put_lseg(pgio->pg_lseg);
 799        pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 800                                           nfs_req_openctx(req),
 801                                           req_offset(req),
 802                                           req->wb_bytes,
 803                                           IOMODE_READ,
 804                                           strict_iomode,
 805                                           GFP_KERNEL);
 806        if (IS_ERR(pgio->pg_lseg)) {
 807                pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 808                pgio->pg_lseg = NULL;
 809        }
 810}
 811
 812static void
 813ff_layout_pg_check_layout(struct nfs_pageio_descriptor *pgio,
 814                          struct nfs_page *req)
 815{
 816        pnfs_generic_pg_check_layout(pgio);
 817        pnfs_generic_pg_check_range(pgio, req);
 818}
 819
 820static void
 821ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 822                        struct nfs_page *req)
 823{
 824        struct nfs_pgio_mirror *pgm;
 825        struct nfs4_ff_layout_mirror *mirror;
 826        struct nfs4_pnfs_ds *ds;
 827        int ds_idx;
 828
 829retry:
 830        ff_layout_pg_check_layout(pgio, req);
 831        /* Use full layout for now */
 832        if (!pgio->pg_lseg) {
 833                ff_layout_pg_get_read(pgio, req, false);
 834                if (!pgio->pg_lseg)
 835                        goto out_nolseg;
 836        }
 837        if (ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
 838                ff_layout_pg_get_read(pgio, req, true);
 839                if (!pgio->pg_lseg)
 840                        goto out_nolseg;
 841        }
 842
 843        ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
 844        if (!ds) {
 845                if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 846                        goto out_mds;
 847                pnfs_put_lseg(pgio->pg_lseg);
 848                pgio->pg_lseg = NULL;
 849                /* Sleep for 1 second before retrying */
 850                ssleep(1);
 851                goto retry;
 852        }
 853
 854        mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 855
 856        pgio->pg_mirror_idx = ds_idx;
 857
 858        /* read always uses only one mirror - idx 0 for pgio layer */
 859        pgm = &pgio->pg_mirrors[0];
 860        pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 861
 862        if (NFS_SERVER(pgio->pg_inode)->flags &
 863                        (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))
 864                pgio->pg_maxretrans = io_maxretrans;
 865        return;
 866out_nolseg:
 867        if (pgio->pg_error < 0)
 868                return;
 869out_mds:
 870        trace_pnfs_mds_fallback_pg_init_read(pgio->pg_inode,
 871                        0, NFS4_MAX_UINT64, IOMODE_READ,
 872                        NFS_I(pgio->pg_inode)->layout,
 873                        pgio->pg_lseg);
 874        pnfs_put_lseg(pgio->pg_lseg);
 875        pgio->pg_lseg = NULL;
 876        pgio->pg_maxretrans = 0;
 877        nfs_pageio_reset_read_mds(pgio);
 878}
 879
 880static void
 881ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 882                        struct nfs_page *req)
 883{
 884        struct nfs4_ff_layout_mirror *mirror;
 885        struct nfs_pgio_mirror *pgm;
 886        struct nfs4_pnfs_ds *ds;
 887        int i;
 888
 889retry:
 890        ff_layout_pg_check_layout(pgio, req);
 891        if (!pgio->pg_lseg) {
 892                pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 893                                                   nfs_req_openctx(req),
 894                                                   req_offset(req),
 895                                                   req->wb_bytes,
 896                                                   IOMODE_RW,
 897                                                   false,
 898                                                   GFP_NOFS);
 899                if (IS_ERR(pgio->pg_lseg)) {
 900                        pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 901                        pgio->pg_lseg = NULL;
 902                        return;
 903                }
 904        }
 905        /* If no lseg, fall back to write through mds */
 906        if (pgio->pg_lseg == NULL)
 907                goto out_mds;
 908
 909        /* Use a direct mapping of ds_idx to pgio mirror_idx */
 910        if (pgio->pg_mirror_count != FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg))
 911                goto out_eagain;
 912
 913        for (i = 0; i < pgio->pg_mirror_count; i++) {
 914                mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 915                ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, mirror, true);
 916                if (!ds) {
 917                        if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 918                                goto out_mds;
 919                        pnfs_put_lseg(pgio->pg_lseg);
 920                        pgio->pg_lseg = NULL;
 921                        /* Sleep for 1 second before retrying */
 922                        ssleep(1);
 923                        goto retry;
 924                }
 925                pgm = &pgio->pg_mirrors[i];
 926                pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 927        }
 928
 929        if (NFS_SERVER(pgio->pg_inode)->flags &
 930                        (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))
 931                pgio->pg_maxretrans = io_maxretrans;
 932        return;
 933out_eagain:
 934        pnfs_generic_pg_cleanup(pgio);
 935        pgio->pg_error = -EAGAIN;
 936        return;
 937out_mds:
 938        trace_pnfs_mds_fallback_pg_init_write(pgio->pg_inode,
 939                        0, NFS4_MAX_UINT64, IOMODE_RW,
 940                        NFS_I(pgio->pg_inode)->layout,
 941                        pgio->pg_lseg);
 942        pnfs_put_lseg(pgio->pg_lseg);
 943        pgio->pg_lseg = NULL;
 944        pgio->pg_maxretrans = 0;
 945        nfs_pageio_reset_write_mds(pgio);
 946        pgio->pg_error = -EAGAIN;
 947}
 948
 949static unsigned int
 950ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 951                                    struct nfs_page *req)
 952{
 953        if (!pgio->pg_lseg) {
 954                pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 955                                                   nfs_req_openctx(req),
 956                                                   0,
 957                                                   NFS4_MAX_UINT64,
 958                                                   IOMODE_RW,
 959                                                   false,
 960                                                   GFP_NOFS);
 961                if (IS_ERR(pgio->pg_lseg)) {
 962                        pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 963                        pgio->pg_lseg = NULL;
 964                        goto out;
 965                }
 966        }
 967        if (pgio->pg_lseg)
 968                return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 969
 970        trace_pnfs_mds_fallback_pg_get_mirror_count(pgio->pg_inode,
 971                        0, NFS4_MAX_UINT64, IOMODE_RW,
 972                        NFS_I(pgio->pg_inode)->layout,
 973                        pgio->pg_lseg);
 974        /* no lseg means that pnfs is not in use, so no mirroring here */
 975        nfs_pageio_reset_write_mds(pgio);
 976out:
 977        return 1;
 978}
 979
 980static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 981        .pg_init = ff_layout_pg_init_read,
 982        .pg_test = pnfs_generic_pg_test,
 983        .pg_doio = pnfs_generic_pg_readpages,
 984        .pg_cleanup = pnfs_generic_pg_cleanup,
 985};
 986
 987static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 988        .pg_init = ff_layout_pg_init_write,
 989        .pg_test = pnfs_generic_pg_test,
 990        .pg_doio = pnfs_generic_pg_writepages,
 991        .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 992        .pg_cleanup = pnfs_generic_pg_cleanup,
 993};
 994
 995static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 996{
 997        struct rpc_task *task = &hdr->task;
 998
 999        pnfs_layoutcommit_inode(hdr->inode, false);
1000
1001        if (retry_pnfs) {
1002                dprintk("%s Reset task %5u for i/o through pNFS "
1003                        "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1004                        hdr->task.tk_pid,
1005                        hdr->inode->i_sb->s_id,
1006                        (unsigned long long)NFS_FILEID(hdr->inode),
1007                        hdr->args.count,
1008                        (unsigned long long)hdr->args.offset);
1009
1010                hdr->completion_ops->reschedule_io(hdr);
1011                return;
1012        }
1013
1014        if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1015                dprintk("%s Reset task %5u for i/o through MDS "
1016                        "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1017                        hdr->task.tk_pid,
1018                        hdr->inode->i_sb->s_id,
1019                        (unsigned long long)NFS_FILEID(hdr->inode),
1020                        hdr->args.count,
1021                        (unsigned long long)hdr->args.offset);
1022
1023                trace_pnfs_mds_fallback_write_done(hdr->inode,
1024                                hdr->args.offset, hdr->args.count,
1025                                IOMODE_RW, NFS_I(hdr->inode)->layout,
1026                                hdr->lseg);
1027                task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1028        }
1029}
1030
1031static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1032{
1033        struct rpc_task *task = &hdr->task;
1034
1035        pnfs_layoutcommit_inode(hdr->inode, false);
1036
1037        if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1038                dprintk("%s Reset task %5u for i/o through MDS "
1039                        "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1040                        hdr->task.tk_pid,
1041                        hdr->inode->i_sb->s_id,
1042                        (unsigned long long)NFS_FILEID(hdr->inode),
1043                        hdr->args.count,
1044                        (unsigned long long)hdr->args.offset);
1045
1046                trace_pnfs_mds_fallback_read_done(hdr->inode,
1047                                hdr->args.offset, hdr->args.count,
1048                                IOMODE_READ, NFS_I(hdr->inode)->layout,
1049                                hdr->lseg);
1050                task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1051        }
1052}
1053
1054static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1055                                           struct nfs4_state *state,
1056                                           struct nfs_client *clp,
1057                                           struct pnfs_layout_segment *lseg,
1058                                           int idx)
1059{
1060        struct pnfs_layout_hdr *lo = lseg->pls_layout;
1061        struct inode *inode = lo->plh_inode;
1062        struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1063        struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1064
1065        switch (task->tk_status) {
1066        case -NFS4ERR_BADSESSION:
1067        case -NFS4ERR_BADSLOT:
1068        case -NFS4ERR_BAD_HIGH_SLOT:
1069        case -NFS4ERR_DEADSESSION:
1070        case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1071        case -NFS4ERR_SEQ_FALSE_RETRY:
1072        case -NFS4ERR_SEQ_MISORDERED:
1073                dprintk("%s ERROR %d, Reset session. Exchangeid "
1074                        "flags 0x%x\n", __func__, task->tk_status,
1075                        clp->cl_exchange_flags);
1076                nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1077                break;
1078        case -NFS4ERR_DELAY:
1079        case -NFS4ERR_GRACE:
1080                rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1081                break;
1082        case -NFS4ERR_RETRY_UNCACHED_REP:
1083                break;
1084        /* Invalidate Layout errors */
1085        case -NFS4ERR_PNFS_NO_LAYOUT:
1086        case -ESTALE:           /* mapped NFS4ERR_STALE */
1087        case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1088        case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1089        case -NFS4ERR_FHEXPIRED:
1090        case -NFS4ERR_WRONG_TYPE:
1091                dprintk("%s Invalid layout error %d\n", __func__,
1092                        task->tk_status);
1093                /*
1094                 * Destroy layout so new i/o will get a new layout.
1095                 * Layout will not be destroyed until all current lseg
1096                 * references are put. Mark layout as invalid to resend failed
1097                 * i/o and all i/o waiting on the slot table to the MDS until
1098                 * layout is destroyed and a new valid layout is obtained.
1099                 */
1100                pnfs_destroy_layout(NFS_I(inode));
1101                rpc_wake_up(&tbl->slot_tbl_waitq);
1102                goto reset;
1103        /* RPC connection errors */
1104        case -ECONNREFUSED:
1105        case -EHOSTDOWN:
1106        case -EHOSTUNREACH:
1107        case -ENETUNREACH:
1108        case -EIO:
1109        case -ETIMEDOUT:
1110        case -EPIPE:
1111                dprintk("%s DS connection error %d\n", __func__,
1112                        task->tk_status);
1113                nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1114                                &devid->deviceid);
1115                rpc_wake_up(&tbl->slot_tbl_waitq);
1116                /* fall through */
1117        default:
1118                if (ff_layout_avoid_mds_available_ds(lseg))
1119                        return -NFS4ERR_RESET_TO_PNFS;
1120reset:
1121                dprintk("%s Retry through MDS. Error %d\n", __func__,
1122                        task->tk_status);
1123                return -NFS4ERR_RESET_TO_MDS;
1124        }
1125        task->tk_status = 0;
1126        return -EAGAIN;
1127}
1128
1129/* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1130static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1131                                           struct pnfs_layout_segment *lseg,
1132                                           int idx)
1133{
1134        struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1135
1136        switch (task->tk_status) {
1137        /* File access problems. Don't mark the device as unavailable */
1138        case -EACCES:
1139        case -ESTALE:
1140        case -EISDIR:
1141        case -EBADHANDLE:
1142        case -ELOOP:
1143        case -ENOSPC:
1144                break;
1145        case -EJUKEBOX:
1146                nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1147                goto out_retry;
1148        default:
1149                dprintk("%s DS connection error %d\n", __func__,
1150                        task->tk_status);
1151                nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1152                                &devid->deviceid);
1153        }
1154        /* FIXME: Need to prevent infinite looping here. */
1155        return -NFS4ERR_RESET_TO_PNFS;
1156out_retry:
1157        task->tk_status = 0;
1158        rpc_restart_call_prepare(task);
1159        rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1160        return -EAGAIN;
1161}
1162
1163static int ff_layout_async_handle_error(struct rpc_task *task,
1164                                        struct nfs4_state *state,
1165                                        struct nfs_client *clp,
1166                                        struct pnfs_layout_segment *lseg,
1167                                        int idx)
1168{
1169        int vers = clp->cl_nfs_mod->rpc_vers->number;
1170
1171        if (task->tk_status >= 0) {
1172                ff_layout_mark_ds_reachable(lseg, idx);
1173                return 0;
1174        }
1175
1176        /* Handle the case of an invalid layout segment */
1177        if (!pnfs_is_valid_lseg(lseg))
1178                return -NFS4ERR_RESET_TO_PNFS;
1179
1180        switch (vers) {
1181        case 3:
1182                return ff_layout_async_handle_error_v3(task, lseg, idx);
1183        case 4:
1184                return ff_layout_async_handle_error_v4(task, state, clp,
1185                                                       lseg, idx);
1186        default:
1187                /* should never happen */
1188                WARN_ON_ONCE(1);
1189                return 0;
1190        }
1191}
1192
1193static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1194                                        int idx, u64 offset, u64 length,
1195                                        u32 *op_status, int opnum, int error)
1196{
1197        struct nfs4_ff_layout_mirror *mirror;
1198        u32 status = *op_status;
1199        int err;
1200
1201        if (status == 0) {
1202                switch (error) {
1203                case -ETIMEDOUT:
1204                case -EPFNOSUPPORT:
1205                case -EPROTONOSUPPORT:
1206                case -EOPNOTSUPP:
1207                case -ECONNREFUSED:
1208                case -ECONNRESET:
1209                case -EHOSTDOWN:
1210                case -EHOSTUNREACH:
1211                case -ENETUNREACH:
1212                case -EADDRINUSE:
1213                case -ENOBUFS:
1214                case -EPIPE:
1215                case -EPERM:
1216                        *op_status = status = NFS4ERR_NXIO;
1217                        break;
1218                case -EACCES:
1219                        *op_status = status = NFS4ERR_ACCESS;
1220                        break;
1221                default:
1222                        return;
1223                }
1224        }
1225
1226        mirror = FF_LAYOUT_COMP(lseg, idx);
1227        err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1228                                       mirror, offset, length, status, opnum,
1229                                       GFP_NOIO);
1230
1231        switch (status) {
1232        case NFS4ERR_DELAY:
1233        case NFS4ERR_GRACE:
1234                break;
1235        case NFS4ERR_NXIO:
1236                ff_layout_mark_ds_unreachable(lseg, idx);
1237                /* Fallthrough */
1238        default:
1239                pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
1240                                                  lseg);
1241        }
1242
1243        dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1244}
1245
1246/* NFS_PROTO call done callback routines */
1247static int ff_layout_read_done_cb(struct rpc_task *task,
1248                                struct nfs_pgio_header *hdr)
1249{
1250        int new_idx = hdr->pgio_mirror_idx;
1251        int err;
1252
1253        if (task->tk_status < 0) {
1254                ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1255                                            hdr->args.offset, hdr->args.count,
1256                                            &hdr->res.op_status, OP_READ,
1257                                            task->tk_status);
1258                trace_ff_layout_read_error(hdr);
1259        }
1260
1261        err = ff_layout_async_handle_error(task, hdr->args.context->state,
1262                                           hdr->ds_clp, hdr->lseg,
1263                                           hdr->pgio_mirror_idx);
1264
1265        trace_nfs4_pnfs_read(hdr, err);
1266        clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1267        clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1268        switch (err) {
1269        case -NFS4ERR_RESET_TO_PNFS:
1270                if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1271                                        hdr->pgio_mirror_idx + 1,
1272                                        &new_idx))
1273                        goto out_layouterror;
1274                set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1275                return task->tk_status;
1276        case -NFS4ERR_RESET_TO_MDS:
1277                set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1278                return task->tk_status;
1279        case -EAGAIN:
1280                goto out_eagain;
1281        }
1282
1283        return 0;
1284out_layouterror:
1285        ff_layout_read_record_layoutstats_done(task, hdr);
1286        ff_layout_send_layouterror(hdr->lseg);
1287        hdr->pgio_mirror_idx = new_idx;
1288out_eagain:
1289        rpc_restart_call_prepare(task);
1290        return -EAGAIN;
1291}
1292
1293static bool
1294ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1295{
1296        return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1297}
1298
1299/*
1300 * We reference the rpc_cred of the first WRITE that triggers the need for
1301 * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1302 * rfc5661 is not clear about which credential should be used.
1303 *
1304 * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1305 * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1306 * we always send layoutcommit after DS writes.
1307 */
1308static void
1309ff_layout_set_layoutcommit(struct inode *inode,
1310                struct pnfs_layout_segment *lseg,
1311                loff_t end_offset)
1312{
1313        if (!ff_layout_need_layoutcommit(lseg))
1314                return;
1315
1316        pnfs_set_layoutcommit(inode, lseg, end_offset);
1317        dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1318                (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1319}
1320
1321static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1322                struct nfs_pgio_header *hdr)
1323{
1324        if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1325                return;
1326        nfs4_ff_layout_stat_io_start_read(hdr->inode,
1327                        FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1328                        hdr->args.count,
1329                        task->tk_start);
1330}
1331
1332static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1333                struct nfs_pgio_header *hdr)
1334{
1335        if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1336                return;
1337        nfs4_ff_layout_stat_io_end_read(task,
1338                        FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1339                        hdr->args.count,
1340                        hdr->res.count);
1341        set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1342}
1343
1344static int ff_layout_read_prepare_common(struct rpc_task *task,
1345                                         struct nfs_pgio_header *hdr)
1346{
1347        if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1348                rpc_exit(task, -EIO);
1349                return -EIO;
1350        }
1351
1352        ff_layout_read_record_layoutstats_start(task, hdr);
1353        return 0;
1354}
1355
1356/*
1357 * Call ops for the async read/write cases
1358 * In the case of dense layouts, the offset needs to be reset to its
1359 * original value.
1360 */
1361static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1362{
1363        struct nfs_pgio_header *hdr = data;
1364
1365        if (ff_layout_read_prepare_common(task, hdr))
1366                return;
1367
1368        rpc_call_start(task);
1369}
1370
1371static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1372{
1373        struct nfs_pgio_header *hdr = data;
1374
1375        if (nfs4_setup_sequence(hdr->ds_clp,
1376                                &hdr->args.seq_args,
1377                                &hdr->res.seq_res,
1378                                task))
1379                return;
1380
1381        ff_layout_read_prepare_common(task, hdr);
1382}
1383
1384static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1385{
1386        struct nfs_pgio_header *hdr = data;
1387
1388        dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1389
1390        if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1391            task->tk_status == 0) {
1392                nfs4_sequence_done(task, &hdr->res.seq_res);
1393                return;
1394        }
1395
1396        /* Note this may cause RPC to be resent */
1397        hdr->mds_ops->rpc_call_done(task, hdr);
1398}
1399
1400static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1401{
1402        struct nfs_pgio_header *hdr = data;
1403
1404        ff_layout_read_record_layoutstats_done(task, hdr);
1405        rpc_count_iostats_metrics(task,
1406            &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1407}
1408
1409static void ff_layout_read_release(void *data)
1410{
1411        struct nfs_pgio_header *hdr = data;
1412
1413        ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1414        if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags)) {
1415                ff_layout_send_layouterror(hdr->lseg);
1416                pnfs_read_resend_pnfs(hdr);
1417        } else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1418                ff_layout_reset_read(hdr);
1419        pnfs_generic_rw_release(data);
1420}
1421
1422
1423static int ff_layout_write_done_cb(struct rpc_task *task,
1424                                struct nfs_pgio_header *hdr)
1425{
1426        loff_t end_offs = 0;
1427        int err;
1428
1429        if (task->tk_status < 0) {
1430                ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1431                                            hdr->args.offset, hdr->args.count,
1432                                            &hdr->res.op_status, OP_WRITE,
1433                                            task->tk_status);
1434                trace_ff_layout_write_error(hdr);
1435        }
1436
1437        err = ff_layout_async_handle_error(task, hdr->args.context->state,
1438                                           hdr->ds_clp, hdr->lseg,
1439                                           hdr->pgio_mirror_idx);
1440
1441        trace_nfs4_pnfs_write(hdr, err);
1442        clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1443        clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1444        switch (err) {
1445        case -NFS4ERR_RESET_TO_PNFS:
1446                set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1447                return task->tk_status;
1448        case -NFS4ERR_RESET_TO_MDS:
1449                set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1450                return task->tk_status;
1451        case -EAGAIN:
1452                return -EAGAIN;
1453        }
1454
1455        if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1456            hdr->res.verf->committed == NFS_DATA_SYNC)
1457                end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1458
1459        /* Note: if the write is unstable, don't set end_offs until commit */
1460        ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1461
1462        /* zero out fattr since we don't care DS attr at all */
1463        hdr->fattr.valid = 0;
1464        if (task->tk_status >= 0)
1465                nfs_writeback_update_inode(hdr);
1466
1467        return 0;
1468}
1469
1470static int ff_layout_commit_done_cb(struct rpc_task *task,
1471                                     struct nfs_commit_data *data)
1472{
1473        int err;
1474
1475        if (task->tk_status < 0) {
1476                ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1477                                            data->args.offset, data->args.count,
1478                                            &data->res.op_status, OP_COMMIT,
1479                                            task->tk_status);
1480                trace_ff_layout_commit_error(data);
1481        }
1482
1483        err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1484                                           data->lseg, data->ds_commit_index);
1485
1486        trace_nfs4_pnfs_commit_ds(data, err);
1487        switch (err) {
1488        case -NFS4ERR_RESET_TO_PNFS:
1489                pnfs_generic_prepare_to_resend_writes(data);
1490                return -EAGAIN;
1491        case -NFS4ERR_RESET_TO_MDS:
1492                pnfs_generic_prepare_to_resend_writes(data);
1493                return -EAGAIN;
1494        case -EAGAIN:
1495                rpc_restart_call_prepare(task);
1496                return -EAGAIN;
1497        }
1498
1499        ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1500
1501        return 0;
1502}
1503
1504static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1505                struct nfs_pgio_header *hdr)
1506{
1507        if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1508                return;
1509        nfs4_ff_layout_stat_io_start_write(hdr->inode,
1510                        FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1511                        hdr->args.count,
1512                        task->tk_start);
1513}
1514
1515static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1516                struct nfs_pgio_header *hdr)
1517{
1518        if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1519                return;
1520        nfs4_ff_layout_stat_io_end_write(task,
1521                        FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1522                        hdr->args.count, hdr->res.count,
1523                        hdr->res.verf->committed);
1524        set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1525}
1526
1527static int ff_layout_write_prepare_common(struct rpc_task *task,
1528                                          struct nfs_pgio_header *hdr)
1529{
1530        if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1531                rpc_exit(task, -EIO);
1532                return -EIO;
1533        }
1534
1535        ff_layout_write_record_layoutstats_start(task, hdr);
1536        return 0;
1537}
1538
1539static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1540{
1541        struct nfs_pgio_header *hdr = data;
1542
1543        if (ff_layout_write_prepare_common(task, hdr))
1544                return;
1545
1546        rpc_call_start(task);
1547}
1548
1549static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1550{
1551        struct nfs_pgio_header *hdr = data;
1552
1553        if (nfs4_setup_sequence(hdr->ds_clp,
1554                                &hdr->args.seq_args,
1555                                &hdr->res.seq_res,
1556                                task))
1557                return;
1558
1559        ff_layout_write_prepare_common(task, hdr);
1560}
1561
1562static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1563{
1564        struct nfs_pgio_header *hdr = data;
1565
1566        if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1567            task->tk_status == 0) {
1568                nfs4_sequence_done(task, &hdr->res.seq_res);
1569                return;
1570        }
1571
1572        /* Note this may cause RPC to be resent */
1573        hdr->mds_ops->rpc_call_done(task, hdr);
1574}
1575
1576static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1577{
1578        struct nfs_pgio_header *hdr = data;
1579
1580        ff_layout_write_record_layoutstats_done(task, hdr);
1581        rpc_count_iostats_metrics(task,
1582            &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1583}
1584
1585static void ff_layout_write_release(void *data)
1586{
1587        struct nfs_pgio_header *hdr = data;
1588
1589        ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1590        if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags)) {
1591                ff_layout_send_layouterror(hdr->lseg);
1592                ff_layout_reset_write(hdr, true);
1593        } else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1594                ff_layout_reset_write(hdr, false);
1595        pnfs_generic_rw_release(data);
1596}
1597
1598static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1599                struct nfs_commit_data *cdata)
1600{
1601        if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1602                return;
1603        nfs4_ff_layout_stat_io_start_write(cdata->inode,
1604                        FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1605                        0, task->tk_start);
1606}
1607
1608static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1609                struct nfs_commit_data *cdata)
1610{
1611        struct nfs_page *req;
1612        __u64 count = 0;
1613
1614        if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1615                return;
1616
1617        if (task->tk_status == 0) {
1618                list_for_each_entry(req, &cdata->pages, wb_list)
1619                        count += req->wb_bytes;
1620        }
1621        nfs4_ff_layout_stat_io_end_write(task,
1622                        FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1623                        count, count, NFS_FILE_SYNC);
1624        set_bit(NFS_LSEG_LAYOUTRETURN, &cdata->lseg->pls_flags);
1625}
1626
1627static void ff_layout_commit_prepare_common(struct rpc_task *task,
1628                struct nfs_commit_data *cdata)
1629{
1630        ff_layout_commit_record_layoutstats_start(task, cdata);
1631}
1632
1633static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1634{
1635        ff_layout_commit_prepare_common(task, data);
1636        rpc_call_start(task);
1637}
1638
1639static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1640{
1641        struct nfs_commit_data *wdata = data;
1642
1643        if (nfs4_setup_sequence(wdata->ds_clp,
1644                                &wdata->args.seq_args,
1645                                &wdata->res.seq_res,
1646                                task))
1647                return;
1648        ff_layout_commit_prepare_common(task, data);
1649}
1650
1651static void ff_layout_commit_done(struct rpc_task *task, void *data)
1652{
1653        pnfs_generic_write_commit_done(task, data);
1654}
1655
1656static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1657{
1658        struct nfs_commit_data *cdata = data;
1659
1660        ff_layout_commit_record_layoutstats_done(task, cdata);
1661        rpc_count_iostats_metrics(task,
1662            &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1663}
1664
1665static void ff_layout_commit_release(void *data)
1666{
1667        struct nfs_commit_data *cdata = data;
1668
1669        ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1670        pnfs_generic_commit_release(data);
1671}
1672
1673static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1674        .rpc_call_prepare = ff_layout_read_prepare_v3,
1675        .rpc_call_done = ff_layout_read_call_done,
1676        .rpc_count_stats = ff_layout_read_count_stats,
1677        .rpc_release = ff_layout_read_release,
1678};
1679
1680static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1681        .rpc_call_prepare = ff_layout_read_prepare_v4,
1682        .rpc_call_done = ff_layout_read_call_done,
1683        .rpc_count_stats = ff_layout_read_count_stats,
1684        .rpc_release = ff_layout_read_release,
1685};
1686
1687static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1688        .rpc_call_prepare = ff_layout_write_prepare_v3,
1689        .rpc_call_done = ff_layout_write_call_done,
1690        .rpc_count_stats = ff_layout_write_count_stats,
1691        .rpc_release = ff_layout_write_release,
1692};
1693
1694static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1695        .rpc_call_prepare = ff_layout_write_prepare_v4,
1696        .rpc_call_done = ff_layout_write_call_done,
1697        .rpc_count_stats = ff_layout_write_count_stats,
1698        .rpc_release = ff_layout_write_release,
1699};
1700
1701static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1702        .rpc_call_prepare = ff_layout_commit_prepare_v3,
1703        .rpc_call_done = ff_layout_commit_done,
1704        .rpc_count_stats = ff_layout_commit_count_stats,
1705        .rpc_release = ff_layout_commit_release,
1706};
1707
1708static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1709        .rpc_call_prepare = ff_layout_commit_prepare_v4,
1710        .rpc_call_done = ff_layout_commit_done,
1711        .rpc_count_stats = ff_layout_commit_count_stats,
1712        .rpc_release = ff_layout_commit_release,
1713};
1714
1715static enum pnfs_try_status
1716ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1717{
1718        struct pnfs_layout_segment *lseg = hdr->lseg;
1719        struct nfs4_pnfs_ds *ds;
1720        struct rpc_clnt *ds_clnt;
1721        struct nfs4_ff_layout_mirror *mirror;
1722        const struct cred *ds_cred;
1723        loff_t offset = hdr->args.offset;
1724        u32 idx = hdr->pgio_mirror_idx;
1725        int vers;
1726        struct nfs_fh *fh;
1727
1728        dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
1729                __func__, hdr->inode->i_ino,
1730                hdr->args.pgbase, (size_t)hdr->args.count, offset);
1731
1732        mirror = FF_LAYOUT_COMP(lseg, idx);
1733        ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false);
1734        if (!ds)
1735                goto out_failed;
1736
1737        ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1738                                                   hdr->inode);
1739        if (IS_ERR(ds_clnt))
1740                goto out_failed;
1741
1742        ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
1743        if (!ds_cred)
1744                goto out_failed;
1745
1746        vers = nfs4_ff_layout_ds_version(mirror);
1747
1748        dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1749                ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers);
1750
1751        hdr->pgio_done_cb = ff_layout_read_done_cb;
1752        refcount_inc(&ds->ds_clp->cl_count);
1753        hdr->ds_clp = ds->ds_clp;
1754        fh = nfs4_ff_layout_select_ds_fh(mirror);
1755        if (fh)
1756                hdr->args.fh = fh;
1757
1758        nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
1759
1760        /*
1761         * Note that if we ever decide to split across DSes,
1762         * then we may need to handle dense-like offsets.
1763         */
1764        hdr->args.offset = offset;
1765        hdr->mds_offset = offset;
1766
1767        /* Perform an asynchronous read to ds */
1768        nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1769                          vers == 3 ? &ff_layout_read_call_ops_v3 :
1770                                      &ff_layout_read_call_ops_v4,
1771                          0, RPC_TASK_SOFTCONN);
1772        put_cred(ds_cred);
1773        return PNFS_ATTEMPTED;
1774
1775out_failed:
1776        if (ff_layout_avoid_mds_available_ds(lseg))
1777                return PNFS_TRY_AGAIN;
1778        trace_pnfs_mds_fallback_read_pagelist(hdr->inode,
1779                        hdr->args.offset, hdr->args.count,
1780                        IOMODE_READ, NFS_I(hdr->inode)->layout, lseg);
1781        return PNFS_NOT_ATTEMPTED;
1782}
1783
1784/* Perform async writes. */
1785static enum pnfs_try_status
1786ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1787{
1788        struct pnfs_layout_segment *lseg = hdr->lseg;
1789        struct nfs4_pnfs_ds *ds;
1790        struct rpc_clnt *ds_clnt;
1791        struct nfs4_ff_layout_mirror *mirror;
1792        const struct cred *ds_cred;
1793        loff_t offset = hdr->args.offset;
1794        int vers;
1795        struct nfs_fh *fh;
1796        int idx = hdr->pgio_mirror_idx;
1797
1798        mirror = FF_LAYOUT_COMP(lseg, idx);
1799        ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
1800        if (!ds)
1801                goto out_failed;
1802
1803        ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1804                                                   hdr->inode);
1805        if (IS_ERR(ds_clnt))
1806                goto out_failed;
1807
1808        ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
1809        if (!ds_cred)
1810                goto out_failed;
1811
1812        vers = nfs4_ff_layout_ds_version(mirror);
1813
1814        dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
1815                __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1816                offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count),
1817                vers);
1818
1819        hdr->pgio_done_cb = ff_layout_write_done_cb;
1820        refcount_inc(&ds->ds_clp->cl_count);
1821        hdr->ds_clp = ds->ds_clp;
1822        hdr->ds_commit_idx = idx;
1823        fh = nfs4_ff_layout_select_ds_fh(mirror);
1824        if (fh)
1825                hdr->args.fh = fh;
1826
1827        nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
1828
1829        /*
1830         * Note that if we ever decide to split across DSes,
1831         * then we may need to handle dense-like offsets.
1832         */
1833        hdr->args.offset = offset;
1834
1835        /* Perform an asynchronous write */
1836        nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1837                          vers == 3 ? &ff_layout_write_call_ops_v3 :
1838                                      &ff_layout_write_call_ops_v4,
1839                          sync, RPC_TASK_SOFTCONN);
1840        put_cred(ds_cred);
1841        return PNFS_ATTEMPTED;
1842
1843out_failed:
1844        if (ff_layout_avoid_mds_available_ds(lseg))
1845                return PNFS_TRY_AGAIN;
1846        trace_pnfs_mds_fallback_write_pagelist(hdr->inode,
1847                        hdr->args.offset, hdr->args.count,
1848                        IOMODE_RW, NFS_I(hdr->inode)->layout, lseg);
1849        return PNFS_NOT_ATTEMPTED;
1850}
1851
1852static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1853{
1854        return i;
1855}
1856
1857static struct nfs_fh *
1858select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1859{
1860        struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1861
1862        /* FIXME: Assume that there is only one NFS version available
1863         * for the DS.
1864         */
1865        return &flseg->mirror_array[i]->fh_versions[0];
1866}
1867
1868static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1869{
1870        struct pnfs_layout_segment *lseg = data->lseg;
1871        struct nfs4_pnfs_ds *ds;
1872        struct rpc_clnt *ds_clnt;
1873        struct nfs4_ff_layout_mirror *mirror;
1874        const struct cred *ds_cred;
1875        u32 idx;
1876        int vers, ret;
1877        struct nfs_fh *fh;
1878
1879        if (!lseg || !(pnfs_is_valid_lseg(lseg) ||
1880            test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags)))
1881                goto out_err;
1882
1883        idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1884        mirror = FF_LAYOUT_COMP(lseg, idx);
1885        ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
1886        if (!ds)
1887                goto out_err;
1888
1889        ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1890                                                   data->inode);
1891        if (IS_ERR(ds_clnt))
1892                goto out_err;
1893
1894        ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, data->cred);
1895        if (!ds_cred)
1896                goto out_err;
1897
1898        vers = nfs4_ff_layout_ds_version(mirror);
1899
1900        dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1901                data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count),
1902                vers);
1903        data->commit_done_cb = ff_layout_commit_done_cb;
1904        data->cred = ds_cred;
1905        refcount_inc(&ds->ds_clp->cl_count);
1906        data->ds_clp = ds->ds_clp;
1907        fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1908        if (fh)
1909                data->args.fh = fh;
1910
1911        ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1912                                   vers == 3 ? &ff_layout_commit_call_ops_v3 :
1913                                               &ff_layout_commit_call_ops_v4,
1914                                   how, RPC_TASK_SOFTCONN);
1915        put_cred(ds_cred);
1916        return ret;
1917out_err:
1918        pnfs_generic_prepare_to_resend_writes(data);
1919        pnfs_generic_commit_release(data);
1920        return -EAGAIN;
1921}
1922
1923static int
1924ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1925                           int how, struct nfs_commit_info *cinfo)
1926{
1927        return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1928                                            ff_layout_initiate_commit);
1929}
1930
1931static struct pnfs_ds_commit_info *
1932ff_layout_get_ds_info(struct inode *inode)
1933{
1934        struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1935
1936        if (layout == NULL)
1937                return NULL;
1938
1939        return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1940}
1941
1942static void
1943ff_layout_setup_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
1944                struct pnfs_layout_segment *lseg)
1945{
1946        struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1947        struct inode *inode = lseg->pls_layout->plh_inode;
1948        struct pnfs_commit_array *array, *new;
1949
1950        new = pnfs_alloc_commit_array(flseg->mirror_array_cnt, GFP_NOIO);
1951        if (new) {
1952                spin_lock(&inode->i_lock);
1953                array = pnfs_add_commit_array(fl_cinfo, new, lseg);
1954                spin_unlock(&inode->i_lock);
1955                if (array != new)
1956                        pnfs_free_commit_array(new);
1957        }
1958}
1959
1960static void
1961ff_layout_release_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
1962                struct inode *inode)
1963{
1964        spin_lock(&inode->i_lock);
1965        pnfs_generic_ds_cinfo_destroy(fl_cinfo);
1966        spin_unlock(&inode->i_lock);
1967}
1968
1969static void
1970ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1971{
1972        nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1973                                                  id_node));
1974}
1975
1976static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
1977                                  const struct nfs4_layoutreturn_args *args,
1978                                  const struct nfs4_flexfile_layoutreturn_args *ff_args)
1979{
1980        __be32 *start;
1981
1982        start = xdr_reserve_space(xdr, 4);
1983        if (unlikely(!start))
1984                return -E2BIG;
1985
1986        *start = cpu_to_be32(ff_args->num_errors);
1987        /* This assume we always return _ALL_ layouts */
1988        return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1989}
1990
1991static void
1992encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1993{
1994        WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
1995}
1996
1997static void
1998ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1999                            const nfs4_stateid *stateid,
2000                            const struct nfs42_layoutstat_devinfo *devinfo)
2001{
2002        __be32 *p;
2003
2004        p = xdr_reserve_space(xdr, 8 + 8);
2005        p = xdr_encode_hyper(p, devinfo->offset);
2006        p = xdr_encode_hyper(p, devinfo->length);
2007        encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
2008        p = xdr_reserve_space(xdr, 4*8);
2009        p = xdr_encode_hyper(p, devinfo->read_count);
2010        p = xdr_encode_hyper(p, devinfo->read_bytes);
2011        p = xdr_encode_hyper(p, devinfo->write_count);
2012        p = xdr_encode_hyper(p, devinfo->write_bytes);
2013        encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
2014}
2015
2016static void
2017ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
2018                            const nfs4_stateid *stateid,
2019                            const struct nfs42_layoutstat_devinfo *devinfo)
2020{
2021        ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
2022        ff_layout_encode_ff_layoutupdate(xdr, devinfo,
2023                        devinfo->ld_private.data);
2024}
2025
2026/* report nothing for now */
2027static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
2028                const struct nfs4_layoutreturn_args *args,
2029                struct nfs4_flexfile_layoutreturn_args *ff_args)
2030{
2031        __be32 *p;
2032        int i;
2033
2034        p = xdr_reserve_space(xdr, 4);
2035        *p = cpu_to_be32(ff_args->num_dev);
2036        for (i = 0; i < ff_args->num_dev; i++)
2037                ff_layout_encode_ff_iostat(xdr,
2038                                &args->layout->plh_stateid,
2039                                &ff_args->devinfo[i]);
2040}
2041
2042static void
2043ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2044                unsigned int num_entries)
2045{
2046        unsigned int i;
2047
2048        for (i = 0; i < num_entries; i++) {
2049                if (!devinfo[i].ld_private.ops)
2050                        continue;
2051                if (!devinfo[i].ld_private.ops->free)
2052                        continue;
2053                devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2054        }
2055}
2056
2057static struct nfs4_deviceid_node *
2058ff_layout_alloc_deviceid_node(struct nfs_server *server,
2059                              struct pnfs_device *pdev, gfp_t gfp_flags)
2060{
2061        struct nfs4_ff_layout_ds *dsaddr;
2062
2063        dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2064        if (!dsaddr)
2065                return NULL;
2066        return &dsaddr->id_node;
2067}
2068
2069static void
2070ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2071                const void *voidargs,
2072                const struct nfs4_xdr_opaque_data *ff_opaque)
2073{
2074        const struct nfs4_layoutreturn_args *args = voidargs;
2075        struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2076        struct xdr_buf tmp_buf = {
2077                .head = {
2078                        [0] = {
2079                                .iov_base = page_address(ff_args->pages[0]),
2080                        },
2081                },
2082                .buflen = PAGE_SIZE,
2083        };
2084        struct xdr_stream tmp_xdr;
2085        __be32 *start;
2086
2087        dprintk("%s: Begin\n", __func__);
2088
2089        xdr_init_encode(&tmp_xdr, &tmp_buf, NULL, NULL);
2090
2091        ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2092        ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2093
2094        start = xdr_reserve_space(xdr, 4);
2095        *start = cpu_to_be32(tmp_buf.len);
2096        xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2097
2098        dprintk("%s: Return\n", __func__);
2099}
2100
2101static void
2102ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2103{
2104        struct nfs4_flexfile_layoutreturn_args *ff_args;
2105
2106        if (!args->data)
2107                return;
2108        ff_args = args->data;
2109        args->data = NULL;
2110
2111        ff_layout_free_ds_ioerr(&ff_args->errors);
2112        ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2113
2114        put_page(ff_args->pages[0]);
2115        kfree(ff_args);
2116}
2117
2118static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2119        .encode = ff_layout_encode_layoutreturn,
2120        .free = ff_layout_free_layoutreturn,
2121};
2122
2123static int
2124ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2125{
2126        struct nfs4_flexfile_layoutreturn_args *ff_args;
2127        struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2128
2129        ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2130        if (!ff_args)
2131                goto out_nomem;
2132        ff_args->pages[0] = alloc_page(GFP_KERNEL);
2133        if (!ff_args->pages[0])
2134                goto out_nomem_free;
2135
2136        INIT_LIST_HEAD(&ff_args->errors);
2137        ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2138                        &args->range, &ff_args->errors,
2139                        FF_LAYOUTRETURN_MAXERR);
2140
2141        spin_lock(&args->inode->i_lock);
2142        ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2143                        &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2144        spin_unlock(&args->inode->i_lock);
2145
2146        args->ld_private->ops = &layoutreturn_ops;
2147        args->ld_private->data = ff_args;
2148        return 0;
2149out_nomem_free:
2150        kfree(ff_args);
2151out_nomem:
2152        return -ENOMEM;
2153}
2154
2155#ifdef CONFIG_NFS_V4_2
2156void
2157ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
2158{
2159        struct pnfs_layout_hdr *lo = lseg->pls_layout;
2160        struct nfs42_layout_error *errors;
2161        LIST_HEAD(head);
2162
2163        if (!nfs_server_capable(lo->plh_inode, NFS_CAP_LAYOUTERROR))
2164                return;
2165        ff_layout_fetch_ds_ioerr(lo, &lseg->pls_range, &head, -1);
2166        if (list_empty(&head))
2167                return;
2168
2169        errors = kmalloc_array(NFS42_LAYOUTERROR_MAX,
2170                        sizeof(*errors), GFP_NOFS);
2171        if (errors != NULL) {
2172                const struct nfs4_ff_layout_ds_err *pos;
2173                size_t n = 0;
2174
2175                list_for_each_entry(pos, &head, list) {
2176                        errors[n].offset = pos->offset;
2177                        errors[n].length = pos->length;
2178                        nfs4_stateid_copy(&errors[n].stateid, &pos->stateid);
2179                        errors[n].errors[0].dev_id = pos->deviceid;
2180                        errors[n].errors[0].status = pos->status;
2181                        errors[n].errors[0].opnum = pos->opnum;
2182                        n++;
2183                        if (!list_is_last(&pos->list, &head) &&
2184                            n < NFS42_LAYOUTERROR_MAX)
2185                                continue;
2186                        if (nfs42_proc_layouterror(lseg, errors, n) < 0)
2187                                break;
2188                        n = 0;
2189                }
2190                kfree(errors);
2191        }
2192        ff_layout_free_ds_ioerr(&head);
2193}
2194#else
2195void
2196ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
2197{
2198}
2199#endif
2200
2201static int
2202ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2203{
2204        const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2205
2206        return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2207}
2208
2209static size_t
2210ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2211                          const int buflen)
2212{
2213        const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2214        const struct in6_addr *addr = &sin6->sin6_addr;
2215
2216        /*
2217         * RFC 4291, Section 2.2.2
2218         *
2219         * Shorthanded ANY address
2220         */
2221        if (ipv6_addr_any(addr))
2222                return snprintf(buf, buflen, "::");
2223
2224        /*
2225         * RFC 4291, Section 2.2.2
2226         *
2227         * Shorthanded loopback address
2228         */
2229        if (ipv6_addr_loopback(addr))
2230                return snprintf(buf, buflen, "::1");
2231
2232        /*
2233         * RFC 4291, Section 2.2.3
2234         *
2235         * Special presentation address format for mapped v4
2236         * addresses.
2237         */
2238        if (ipv6_addr_v4mapped(addr))
2239                return snprintf(buf, buflen, "::ffff:%pI4",
2240                                        &addr->s6_addr32[3]);
2241
2242        /*
2243         * RFC 4291, Section 2.2.1
2244         */
2245        return snprintf(buf, buflen, "%pI6c", addr);
2246}
2247
2248/* Derived from rpc_sockaddr2uaddr */
2249static void
2250ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2251{
2252        struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2253        char portbuf[RPCBIND_MAXUADDRPLEN];
2254        char addrbuf[RPCBIND_MAXUADDRLEN];
2255        char *netid;
2256        unsigned short port;
2257        int len, netid_len;
2258        __be32 *p;
2259
2260        switch (sap->sa_family) {
2261        case AF_INET:
2262                if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2263                        return;
2264                port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2265                netid = "tcp";
2266                netid_len = 3;
2267                break;
2268        case AF_INET6:
2269                if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2270                        return;
2271                port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2272                netid = "tcp6";
2273                netid_len = 4;
2274                break;
2275        default:
2276                /* we only support tcp and tcp6 */
2277                WARN_ON_ONCE(1);
2278                return;
2279        }
2280
2281        snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2282        len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2283
2284        p = xdr_reserve_space(xdr, 4 + netid_len);
2285        xdr_encode_opaque(p, netid, netid_len);
2286
2287        p = xdr_reserve_space(xdr, 4 + len);
2288        xdr_encode_opaque(p, addrbuf, len);
2289}
2290
2291static void
2292ff_layout_encode_nfstime(struct xdr_stream *xdr,
2293                         ktime_t t)
2294{
2295        struct timespec64 ts;
2296        __be32 *p;
2297
2298        p = xdr_reserve_space(xdr, 12);
2299        ts = ktime_to_timespec64(t);
2300        p = xdr_encode_hyper(p, ts.tv_sec);
2301        *p++ = cpu_to_be32(ts.tv_nsec);
2302}
2303
2304static void
2305ff_layout_encode_io_latency(struct xdr_stream *xdr,
2306                            struct nfs4_ff_io_stat *stat)
2307{
2308        __be32 *p;
2309
2310        p = xdr_reserve_space(xdr, 5 * 8);
2311        p = xdr_encode_hyper(p, stat->ops_requested);
2312        p = xdr_encode_hyper(p, stat->bytes_requested);
2313        p = xdr_encode_hyper(p, stat->ops_completed);
2314        p = xdr_encode_hyper(p, stat->bytes_completed);
2315        p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2316        ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2317        ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2318}
2319
2320static void
2321ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2322                              const struct nfs42_layoutstat_devinfo *devinfo,
2323                              struct nfs4_ff_layout_mirror *mirror)
2324{
2325        struct nfs4_pnfs_ds_addr *da;
2326        struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2327        struct nfs_fh *fh = &mirror->fh_versions[0];
2328        __be32 *p;
2329
2330        da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2331        dprintk("%s: DS %s: encoding address %s\n",
2332                __func__, ds->ds_remotestr, da->da_remotestr);
2333        /* netaddr4 */
2334        ff_layout_encode_netaddr(xdr, da);
2335        /* nfs_fh4 */
2336        p = xdr_reserve_space(xdr, 4 + fh->size);
2337        xdr_encode_opaque(p, fh->data, fh->size);
2338        /* ff_io_latency4 read */
2339        spin_lock(&mirror->lock);
2340        ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2341        /* ff_io_latency4 write */
2342        ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2343        spin_unlock(&mirror->lock);
2344        /* nfstime4 */
2345        ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2346        /* bool */
2347        p = xdr_reserve_space(xdr, 4);
2348        *p = cpu_to_be32(false);
2349}
2350
2351static void
2352ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2353                             const struct nfs4_xdr_opaque_data *opaque)
2354{
2355        struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2356                        struct nfs42_layoutstat_devinfo, ld_private);
2357        __be32 *start;
2358
2359        /* layoutupdate length */
2360        start = xdr_reserve_space(xdr, 4);
2361        ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2362
2363        *start = cpu_to_be32((xdr->p - start - 1) * 4);
2364}
2365
2366static void
2367ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2368{
2369        struct nfs4_ff_layout_mirror *mirror = opaque->data;
2370
2371        ff_layout_put_mirror(mirror);
2372}
2373
2374static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2375        .encode = ff_layout_encode_layoutstats,
2376        .free   = ff_layout_free_layoutstats,
2377};
2378
2379static int
2380ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2381                               struct nfs42_layoutstat_devinfo *devinfo,
2382                               int dev_limit)
2383{
2384        struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2385        struct nfs4_ff_layout_mirror *mirror;
2386        struct nfs4_deviceid_node *dev;
2387        int i = 0;
2388
2389        list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2390                if (i >= dev_limit)
2391                        break;
2392                if (IS_ERR_OR_NULL(mirror->mirror_ds))
2393                        continue;
2394                if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2395                        continue;
2396                /* mirror refcount put in cleanup_layoutstats */
2397                if (!refcount_inc_not_zero(&mirror->ref))
2398                        continue;
2399                dev = &mirror->mirror_ds->id_node; 
2400                memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2401                devinfo->offset = 0;
2402                devinfo->length = NFS4_MAX_UINT64;
2403                spin_lock(&mirror->lock);
2404                devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2405                devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2406                devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2407                devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2408                spin_unlock(&mirror->lock);
2409                devinfo->layout_type = LAYOUT_FLEX_FILES;
2410                devinfo->ld_private.ops = &layoutstat_ops;
2411                devinfo->ld_private.data = mirror;
2412
2413                devinfo++;
2414                i++;
2415        }
2416        return i;
2417}
2418
2419static int
2420ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2421{
2422        struct nfs4_flexfile_layout *ff_layout;
2423        const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2424
2425        /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2426        args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2427        if (!args->devinfo)
2428                return -ENOMEM;
2429
2430        spin_lock(&args->inode->i_lock);
2431        ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2432        args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2433                        &args->devinfo[0], dev_count);
2434        spin_unlock(&args->inode->i_lock);
2435        if (!args->num_dev) {
2436                kfree(args->devinfo);
2437                args->devinfo = NULL;
2438                return -ENOENT;
2439        }
2440
2441        return 0;
2442}
2443
2444static int
2445ff_layout_set_layoutdriver(struct nfs_server *server,
2446                const struct nfs_fh *dummy)
2447{
2448#if IS_ENABLED(CONFIG_NFS_V4_2)
2449        server->caps |= NFS_CAP_LAYOUTSTATS;
2450#endif
2451        return 0;
2452}
2453
2454static const struct pnfs_commit_ops ff_layout_commit_ops = {
2455        .setup_ds_info          = ff_layout_setup_ds_info,
2456        .release_ds_info        = ff_layout_release_ds_info,
2457        .mark_request_commit    = pnfs_layout_mark_request_commit,
2458        .clear_request_commit   = pnfs_generic_clear_request_commit,
2459        .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2460        .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2461        .commit_pagelist        = ff_layout_commit_pagelist,
2462};
2463
2464static struct pnfs_layoutdriver_type flexfilelayout_type = {
2465        .id                     = LAYOUT_FLEX_FILES,
2466        .name                   = "LAYOUT_FLEX_FILES",
2467        .owner                  = THIS_MODULE,
2468        .flags                  = PNFS_LAYOUTGET_ON_OPEN,
2469        .max_layoutget_response = 4096, /* 1 page or so... */
2470        .set_layoutdriver       = ff_layout_set_layoutdriver,
2471        .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2472        .free_layout_hdr        = ff_layout_free_layout_hdr,
2473        .alloc_lseg             = ff_layout_alloc_lseg,
2474        .free_lseg              = ff_layout_free_lseg,
2475        .add_lseg               = ff_layout_add_lseg,
2476        .pg_read_ops            = &ff_layout_pg_read_ops,
2477        .pg_write_ops           = &ff_layout_pg_write_ops,
2478        .get_ds_info            = ff_layout_get_ds_info,
2479        .free_deviceid_node     = ff_layout_free_deviceid_node,
2480        .read_pagelist          = ff_layout_read_pagelist,
2481        .write_pagelist         = ff_layout_write_pagelist,
2482        .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2483        .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2484        .sync                   = pnfs_nfs_generic_sync,
2485        .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2486};
2487
2488static int __init nfs4flexfilelayout_init(void)
2489{
2490        printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2491               __func__);
2492        return pnfs_register_layoutdriver(&flexfilelayout_type);
2493}
2494
2495static void __exit nfs4flexfilelayout_exit(void)
2496{
2497        printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2498               __func__);
2499        pnfs_unregister_layoutdriver(&flexfilelayout_type);
2500}
2501
2502MODULE_ALIAS("nfs-layouttype4-4");
2503
2504MODULE_LICENSE("GPL");
2505MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2506
2507module_init(nfs4flexfilelayout_init);
2508module_exit(nfs4flexfilelayout_exit);
2509
2510module_param(io_maxretrans, ushort, 0644);
2511MODULE_PARM_DESC(io_maxretrans, "The  number of times the NFSv4.1 client "
2512                        "retries an I/O request before returning an error. ");
2513