linux/fs/nfs/objlayout/objio_osd.c
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   1/*
   2 *  pNFS Objects layout implementation over open-osd initiator library
   3 *
   4 *  Copyright (C) 2009 Panasas Inc. [year of first publication]
   5 *  All rights reserved.
   6 *
   7 *  Benny Halevy <bhalevy@panasas.com>
   8 *  Boaz Harrosh <bharrosh@panasas.com>
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License version 2
  12 *  See the file COPYING included with this distribution for more details.
  13 *
  14 *  Redistribution and use in source and binary forms, with or without
  15 *  modification, are permitted provided that the following conditions
  16 *  are met:
  17 *
  18 *  1. Redistributions of source code must retain the above copyright
  19 *     notice, this list of conditions and the following disclaimer.
  20 *  2. Redistributions in binary form must reproduce the above copyright
  21 *     notice, this list of conditions and the following disclaimer in the
  22 *     documentation and/or other materials provided with the distribution.
  23 *  3. Neither the name of the Panasas company nor the names of its
  24 *     contributors may be used to endorse or promote products derived
  25 *     from this software without specific prior written permission.
  26 *
  27 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  28 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  29 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  30 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  32 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  33 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  34 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  35 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  36 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  37 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38 */
  39
  40#include <linux/module.h>
  41#include <scsi/osd_ore.h>
  42
  43#include "objlayout.h"
  44#include "../internal.h"
  45
  46#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  47
  48struct objio_dev_ent {
  49        struct nfs4_deviceid_node id_node;
  50        struct ore_dev od;
  51};
  52
  53static void
  54objio_free_deviceid_node(struct nfs4_deviceid_node *d)
  55{
  56        struct objio_dev_ent *de = container_of(d, struct objio_dev_ent, id_node);
  57
  58        dprintk("%s: free od=%p\n", __func__, de->od.od);
  59        osduld_put_device(de->od.od);
  60        kfree(de);
  61}
  62
  63static struct objio_dev_ent *_dev_list_find(const struct nfs_server *nfss,
  64        const struct nfs4_deviceid *d_id)
  65{
  66        struct nfs4_deviceid_node *d;
  67        struct objio_dev_ent *de;
  68
  69        d = nfs4_find_get_deviceid(nfss->pnfs_curr_ld, nfss->nfs_client, d_id);
  70        if (!d)
  71                return NULL;
  72
  73        de = container_of(d, struct objio_dev_ent, id_node);
  74        return de;
  75}
  76
  77static struct objio_dev_ent *
  78_dev_list_add(const struct nfs_server *nfss,
  79        const struct nfs4_deviceid *d_id, struct osd_dev *od,
  80        gfp_t gfp_flags)
  81{
  82        struct nfs4_deviceid_node *d;
  83        struct objio_dev_ent *de = kzalloc(sizeof(*de), gfp_flags);
  84        struct objio_dev_ent *n;
  85
  86        if (!de) {
  87                dprintk("%s: -ENOMEM od=%p\n", __func__, od);
  88                return NULL;
  89        }
  90
  91        dprintk("%s: Adding od=%p\n", __func__, od);
  92        nfs4_init_deviceid_node(&de->id_node,
  93                                nfss->pnfs_curr_ld,
  94                                nfss->nfs_client,
  95                                d_id);
  96        de->od.od = od;
  97
  98        d = nfs4_insert_deviceid_node(&de->id_node);
  99        n = container_of(d, struct objio_dev_ent, id_node);
 100        if (n != de) {
 101                dprintk("%s: Race with other n->od=%p\n", __func__, n->od.od);
 102                objio_free_deviceid_node(&de->id_node);
 103                de = n;
 104        }
 105
 106        return de;
 107}
 108
 109struct objio_segment {
 110        struct pnfs_layout_segment lseg;
 111
 112        struct ore_layout layout;
 113        struct ore_components oc;
 114};
 115
 116static inline struct objio_segment *
 117OBJIO_LSEG(struct pnfs_layout_segment *lseg)
 118{
 119        return container_of(lseg, struct objio_segment, lseg);
 120}
 121
 122struct objio_state {
 123        /* Generic layer */
 124        struct objlayout_io_res oir;
 125
 126        bool sync;
 127        /*FIXME: Support for extra_bytes at ore_get_rw_state() */
 128        struct ore_io_state *ios;
 129};
 130
 131/* Send and wait for a get_device_info of devices in the layout,
 132   then look them up with the osd_initiator library */
 133static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay,
 134        struct objio_segment *objio_seg, unsigned c, struct nfs4_deviceid *d_id,
 135        gfp_t gfp_flags)
 136{
 137        struct pnfs_osd_deviceaddr *deviceaddr;
 138        struct objio_dev_ent *ode;
 139        struct osd_dev *od;
 140        struct osd_dev_info odi;
 141        bool retry_flag = true;
 142        int err;
 143
 144        ode = _dev_list_find(NFS_SERVER(pnfslay->plh_inode), d_id);
 145        if (ode) {
 146                objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
 147                return 0;
 148        }
 149
 150        err = objlayout_get_deviceinfo(pnfslay, d_id, &deviceaddr, gfp_flags);
 151        if (unlikely(err)) {
 152                dprintk("%s: objlayout_get_deviceinfo dev(%llx:%llx) =>%d\n",
 153                        __func__, _DEVID_LO(d_id), _DEVID_HI(d_id), err);
 154                return err;
 155        }
 156
 157        odi.systemid_len = deviceaddr->oda_systemid.len;
 158        if (odi.systemid_len > sizeof(odi.systemid)) {
 159                dprintk("%s: odi.systemid_len > sizeof(systemid=%zd)\n",
 160                        __func__, sizeof(odi.systemid));
 161                err = -EINVAL;
 162                goto out;
 163        } else if (odi.systemid_len)
 164                memcpy(odi.systemid, deviceaddr->oda_systemid.data,
 165                       odi.systemid_len);
 166        odi.osdname_len  = deviceaddr->oda_osdname.len;
 167        odi.osdname      = (u8 *)deviceaddr->oda_osdname.data;
 168
 169        if (!odi.osdname_len && !odi.systemid_len) {
 170                dprintk("%s: !odi.osdname_len && !odi.systemid_len\n",
 171                        __func__);
 172                err = -ENODEV;
 173                goto out;
 174        }
 175
 176retry_lookup:
 177        od = osduld_info_lookup(&odi);
 178        if (unlikely(IS_ERR(od))) {
 179                err = PTR_ERR(od);
 180                dprintk("%s: osduld_info_lookup => %d\n", __func__, err);
 181                if (err == -ENODEV && retry_flag) {
 182                        err = objlayout_autologin(deviceaddr);
 183                        if (likely(!err)) {
 184                                retry_flag = false;
 185                                goto retry_lookup;
 186                        }
 187                }
 188                goto out;
 189        }
 190
 191        ode = _dev_list_add(NFS_SERVER(pnfslay->plh_inode), d_id, od,
 192                            gfp_flags);
 193        objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
 194        dprintk("Adding new dev_id(%llx:%llx)\n",
 195                _DEVID_LO(d_id), _DEVID_HI(d_id));
 196out:
 197        objlayout_put_deviceinfo(deviceaddr);
 198        return err;
 199}
 200
 201static void copy_single_comp(struct ore_components *oc, unsigned c,
 202                             struct pnfs_osd_object_cred *src_comp)
 203{
 204        struct ore_comp *ocomp = &oc->comps[c];
 205
 206        WARN_ON(src_comp->oc_cap_key.cred_len > 0); /* libosd is NO_SEC only */
 207        WARN_ON(src_comp->oc_cap.cred_len > sizeof(ocomp->cred));
 208
 209        ocomp->obj.partition = src_comp->oc_object_id.oid_partition_id;
 210        ocomp->obj.id = src_comp->oc_object_id.oid_object_id;
 211
 212        memcpy(ocomp->cred, src_comp->oc_cap.cred, sizeof(ocomp->cred));
 213}
 214
 215static int __alloc_objio_seg(unsigned numdevs, gfp_t gfp_flags,
 216                       struct objio_segment **pseg)
 217{
 218/*      This is the in memory structure of the objio_segment
 219 *
 220 *      struct __alloc_objio_segment {
 221 *              struct objio_segment olseg;
 222 *              struct ore_dev *ods[numdevs];
 223 *              struct ore_comp comps[numdevs];
 224 *      } *aolseg;
 225 *      NOTE: The code as above compiles and runs perfectly. It is elegant,
 226 *      type safe and compact. At some Past time Linus has decided he does not
 227 *      like variable length arrays, For the sake of this principal we uglify
 228 *      the code as below.
 229 */
 230        struct objio_segment *lseg;
 231        size_t lseg_size = sizeof(*lseg) +
 232                        numdevs * sizeof(lseg->oc.ods[0]) +
 233                        numdevs * sizeof(*lseg->oc.comps);
 234
 235        lseg = kzalloc(lseg_size, gfp_flags);
 236        if (unlikely(!lseg)) {
 237                dprintk("%s: Failed allocation numdevs=%d size=%zd\n", __func__,
 238                        numdevs, lseg_size);
 239                return -ENOMEM;
 240        }
 241
 242        lseg->oc.numdevs = numdevs;
 243        lseg->oc.single_comp = EC_MULTPLE_COMPS;
 244        lseg->oc.ods = (void *)(lseg + 1);
 245        lseg->oc.comps = (void *)(lseg->oc.ods + numdevs);
 246
 247        *pseg = lseg;
 248        return 0;
 249}
 250
 251int objio_alloc_lseg(struct pnfs_layout_segment **outp,
 252        struct pnfs_layout_hdr *pnfslay,
 253        struct pnfs_layout_range *range,
 254        struct xdr_stream *xdr,
 255        gfp_t gfp_flags)
 256{
 257        struct objio_segment *objio_seg;
 258        struct pnfs_osd_xdr_decode_layout_iter iter;
 259        struct pnfs_osd_layout layout;
 260        struct pnfs_osd_object_cred src_comp;
 261        unsigned cur_comp;
 262        int err;
 263
 264        err = pnfs_osd_xdr_decode_layout_map(&layout, &iter, xdr);
 265        if (unlikely(err))
 266                return err;
 267
 268        err = __alloc_objio_seg(layout.olo_num_comps, gfp_flags, &objio_seg);
 269        if (unlikely(err))
 270                return err;
 271
 272        objio_seg->layout.stripe_unit = layout.olo_map.odm_stripe_unit;
 273        objio_seg->layout.group_width = layout.olo_map.odm_group_width;
 274        objio_seg->layout.group_depth = layout.olo_map.odm_group_depth;
 275        objio_seg->layout.mirrors_p1 = layout.olo_map.odm_mirror_cnt + 1;
 276        objio_seg->layout.raid_algorithm = layout.olo_map.odm_raid_algorithm;
 277
 278        err = ore_verify_layout(layout.olo_map.odm_num_comps,
 279                                          &objio_seg->layout);
 280        if (unlikely(err))
 281                goto err;
 282
 283        objio_seg->oc.first_dev = layout.olo_comps_index;
 284        cur_comp = 0;
 285        while (pnfs_osd_xdr_decode_layout_comp(&src_comp, &iter, xdr, &err)) {
 286                copy_single_comp(&objio_seg->oc, cur_comp, &src_comp);
 287                err = objio_devices_lookup(pnfslay, objio_seg, cur_comp,
 288                                           &src_comp.oc_object_id.oid_device_id,
 289                                           gfp_flags);
 290                if (err)
 291                        goto err;
 292                ++cur_comp;
 293        }
 294        /* pnfs_osd_xdr_decode_layout_comp returns false on error */
 295        if (unlikely(err))
 296                goto err;
 297
 298        *outp = &objio_seg->lseg;
 299        return 0;
 300
 301err:
 302        kfree(objio_seg);
 303        dprintk("%s: Error: return %d\n", __func__, err);
 304        *outp = NULL;
 305        return err;
 306}
 307
 308void objio_free_lseg(struct pnfs_layout_segment *lseg)
 309{
 310        int i;
 311        struct objio_segment *objio_seg = OBJIO_LSEG(lseg);
 312
 313        for (i = 0; i < objio_seg->oc.numdevs; i++) {
 314                struct ore_dev *od = objio_seg->oc.ods[i];
 315                struct objio_dev_ent *ode;
 316
 317                if (!od)
 318                        break;
 319                ode = container_of(od, typeof(*ode), od);
 320                nfs4_put_deviceid_node(&ode->id_node);
 321        }
 322        kfree(objio_seg);
 323}
 324
 325static int
 326objio_alloc_io_state(struct pnfs_layout_hdr *pnfs_layout_type, bool is_reading,
 327        struct pnfs_layout_segment *lseg, struct page **pages, unsigned pgbase,
 328        loff_t offset, size_t count, void *rpcdata, gfp_t gfp_flags,
 329        struct objio_state **outp)
 330{
 331        struct objio_segment *objio_seg = OBJIO_LSEG(lseg);
 332        struct ore_io_state *ios;
 333        int ret;
 334        struct __alloc_objio_state {
 335                struct objio_state objios;
 336                struct pnfs_osd_ioerr ioerrs[objio_seg->oc.numdevs];
 337        } *aos;
 338
 339        aos = kzalloc(sizeof(*aos), gfp_flags);
 340        if (unlikely(!aos))
 341                return -ENOMEM;
 342
 343        objlayout_init_ioerrs(&aos->objios.oir, objio_seg->oc.numdevs,
 344                        aos->ioerrs, rpcdata, pnfs_layout_type);
 345
 346        ret = ore_get_rw_state(&objio_seg->layout, &objio_seg->oc, is_reading,
 347                               offset, count, &ios);
 348        if (unlikely(ret)) {
 349                kfree(aos);
 350                return ret;
 351        }
 352
 353        ios->pages = pages;
 354        ios->pgbase = pgbase;
 355        ios->private = aos;
 356        BUG_ON(ios->nr_pages > (pgbase + count + PAGE_SIZE - 1) >> PAGE_SHIFT);
 357
 358        aos->objios.sync = 0;
 359        aos->objios.ios = ios;
 360        *outp = &aos->objios;
 361        return 0;
 362}
 363
 364void objio_free_result(struct objlayout_io_res *oir)
 365{
 366        struct objio_state *objios = container_of(oir, struct objio_state, oir);
 367
 368        ore_put_io_state(objios->ios);
 369        kfree(objios);
 370}
 371
 372static enum pnfs_osd_errno osd_pri_2_pnfs_err(enum osd_err_priority oep)
 373{
 374        switch (oep) {
 375        case OSD_ERR_PRI_NO_ERROR:
 376                return (enum pnfs_osd_errno)0;
 377
 378        case OSD_ERR_PRI_CLEAR_PAGES:
 379                BUG_ON(1);
 380                return 0;
 381
 382        case OSD_ERR_PRI_RESOURCE:
 383                return PNFS_OSD_ERR_RESOURCE;
 384        case OSD_ERR_PRI_BAD_CRED:
 385                return PNFS_OSD_ERR_BAD_CRED;
 386        case OSD_ERR_PRI_NO_ACCESS:
 387                return PNFS_OSD_ERR_NO_ACCESS;
 388        case OSD_ERR_PRI_UNREACHABLE:
 389                return PNFS_OSD_ERR_UNREACHABLE;
 390        case OSD_ERR_PRI_NOT_FOUND:
 391                return PNFS_OSD_ERR_NOT_FOUND;
 392        case OSD_ERR_PRI_NO_SPACE:
 393                return PNFS_OSD_ERR_NO_SPACE;
 394        default:
 395                WARN_ON(1);
 396                /* fallthrough */
 397        case OSD_ERR_PRI_EIO:
 398                return PNFS_OSD_ERR_EIO;
 399        }
 400}
 401
 402static void __on_dev_error(struct ore_io_state *ios,
 403        struct ore_dev *od, unsigned dev_index, enum osd_err_priority oep,
 404        u64 dev_offset, u64  dev_len)
 405{
 406        struct objio_state *objios = ios->private;
 407        struct pnfs_osd_objid pooid;
 408        struct objio_dev_ent *ode = container_of(od, typeof(*ode), od);
 409        /* FIXME: what to do with more-then-one-group layouts. We need to
 410         * translate from ore_io_state index to oc->comps index
 411         */
 412        unsigned comp = dev_index;
 413
 414        pooid.oid_device_id = ode->id_node.deviceid;
 415        pooid.oid_partition_id = ios->oc->comps[comp].obj.partition;
 416        pooid.oid_object_id = ios->oc->comps[comp].obj.id;
 417
 418        objlayout_io_set_result(&objios->oir, comp,
 419                                &pooid, osd_pri_2_pnfs_err(oep),
 420                                dev_offset, dev_len, !ios->reading);
 421}
 422
 423/*
 424 * read
 425 */
 426static void _read_done(struct ore_io_state *ios, void *private)
 427{
 428        struct objio_state *objios = private;
 429        ssize_t status;
 430        int ret = ore_check_io(ios, &__on_dev_error);
 431
 432        /* FIXME: _io_free(ios) can we dealocate the libosd resources; */
 433
 434        if (likely(!ret))
 435                status = ios->length;
 436        else
 437                status = ret;
 438
 439        objlayout_read_done(&objios->oir, status, objios->sync);
 440}
 441
 442int objio_read_pagelist(struct nfs_read_data *rdata)
 443{
 444        struct nfs_pgio_header *hdr = rdata->header;
 445        struct objio_state *objios;
 446        int ret;
 447
 448        ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, true,
 449                        hdr->lseg, rdata->args.pages, rdata->args.pgbase,
 450                        rdata->args.offset, rdata->args.count, rdata,
 451                        GFP_KERNEL, &objios);
 452        if (unlikely(ret))
 453                return ret;
 454
 455        objios->ios->done = _read_done;
 456        dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
 457                rdata->args.offset, rdata->args.count);
 458        ret = ore_read(objios->ios);
 459        if (unlikely(ret))
 460                objio_free_result(&objios->oir);
 461        return ret;
 462}
 463
 464/*
 465 * write
 466 */
 467static void _write_done(struct ore_io_state *ios, void *private)
 468{
 469        struct objio_state *objios = private;
 470        ssize_t status;
 471        int ret = ore_check_io(ios, &__on_dev_error);
 472
 473        /* FIXME: _io_free(ios) can we dealocate the libosd resources; */
 474
 475        if (likely(!ret)) {
 476                /* FIXME: should be based on the OSD's persistence model
 477                 * See OSD2r05 Section 4.13 Data persistence model */
 478                objios->oir.committed = NFS_FILE_SYNC;
 479                status = ios->length;
 480        } else {
 481                status = ret;
 482        }
 483
 484        objlayout_write_done(&objios->oir, status, objios->sync);
 485}
 486
 487static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
 488{
 489        struct objio_state *objios = priv;
 490        struct nfs_write_data *wdata = objios->oir.rpcdata;
 491        struct address_space *mapping = wdata->header->inode->i_mapping;
 492        pgoff_t index = offset / PAGE_SIZE;
 493        struct page *page;
 494        loff_t i_size = i_size_read(wdata->header->inode);
 495
 496        if (offset >= i_size) {
 497                *uptodate = true;
 498                dprintk("%s: g_zero_page index=0x%lx\n", __func__, index);
 499                return ZERO_PAGE(0);
 500        }
 501
 502        page = find_get_page(mapping, index);
 503        if (!page) {
 504                page = find_or_create_page(mapping, index, GFP_NOFS);
 505                if (unlikely(!page)) {
 506                        dprintk("%s: grab_cache_page Failed index=0x%lx\n",
 507                                __func__, index);
 508                        return NULL;
 509                }
 510                unlock_page(page);
 511        }
 512        if (PageDirty(page) || PageWriteback(page))
 513                *uptodate = true;
 514        else
 515                *uptodate = PageUptodate(page);
 516        dprintk("%s: index=0x%lx uptodate=%d\n", __func__, index, *uptodate);
 517        return page;
 518}
 519
 520static void __r4w_put_page(void *priv, struct page *page)
 521{
 522        dprintk("%s: index=0x%lx\n", __func__,
 523                (page == ZERO_PAGE(0)) ? -1UL : page->index);
 524        if (ZERO_PAGE(0) != page)
 525                page_cache_release(page);
 526        return;
 527}
 528
 529static const struct _ore_r4w_op _r4w_op = {
 530        .get_page = &__r4w_get_page,
 531        .put_page = &__r4w_put_page,
 532};
 533
 534int objio_write_pagelist(struct nfs_write_data *wdata, int how)
 535{
 536        struct nfs_pgio_header *hdr = wdata->header;
 537        struct objio_state *objios;
 538        int ret;
 539
 540        ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, false,
 541                        hdr->lseg, wdata->args.pages, wdata->args.pgbase,
 542                        wdata->args.offset, wdata->args.count, wdata, GFP_NOFS,
 543                        &objios);
 544        if (unlikely(ret))
 545                return ret;
 546
 547        objios->sync = 0 != (how & FLUSH_SYNC);
 548        objios->ios->r4w = &_r4w_op;
 549
 550        if (!objios->sync)
 551                objios->ios->done = _write_done;
 552
 553        dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
 554                wdata->args.offset, wdata->args.count);
 555        ret = ore_write(objios->ios);
 556        if (unlikely(ret)) {
 557                objio_free_result(&objios->oir);
 558                return ret;
 559        }
 560
 561        if (objios->sync)
 562                _write_done(objios->ios, objios);
 563
 564        return 0;
 565}
 566
 567static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
 568                          struct nfs_page *prev, struct nfs_page *req)
 569{
 570        if (!pnfs_generic_pg_test(pgio, prev, req))
 571                return false;
 572
 573        return pgio->pg_count + req->wb_bytes <=
 574                        (unsigned long)pgio->pg_layout_private;
 575}
 576
 577static void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 578{
 579        pnfs_generic_pg_init_read(pgio, req);
 580        if (unlikely(pgio->pg_lseg == NULL))
 581                return; /* Not pNFS */
 582
 583        pgio->pg_layout_private = (void *)
 584                                OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
 585}
 586
 587static bool aligned_on_raid_stripe(u64 offset, struct ore_layout *layout,
 588                                   unsigned long *stripe_end)
 589{
 590        u32 stripe_off;
 591        unsigned stripe_size;
 592
 593        if (layout->raid_algorithm == PNFS_OSD_RAID_0)
 594                return true;
 595
 596        stripe_size = layout->stripe_unit *
 597                                (layout->group_width - layout->parity);
 598
 599        div_u64_rem(offset, stripe_size, &stripe_off);
 600        if (!stripe_off)
 601                return true;
 602
 603        *stripe_end = stripe_size - stripe_off;
 604        return false;
 605}
 606
 607static void objio_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 608{
 609        unsigned long stripe_end = 0;
 610        u64 wb_size;
 611
 612        if (pgio->pg_dreq == NULL)
 613                wb_size = i_size_read(pgio->pg_inode) - req_offset(req);
 614        else
 615                wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
 616
 617        pnfs_generic_pg_init_write(pgio, req, wb_size);
 618        if (unlikely(pgio->pg_lseg == NULL))
 619                return; /* Not pNFS */
 620
 621        if (req->wb_offset ||
 622            !aligned_on_raid_stripe(req->wb_index * PAGE_SIZE,
 623                               &OBJIO_LSEG(pgio->pg_lseg)->layout,
 624                               &stripe_end)) {
 625                pgio->pg_layout_private = (void *)stripe_end;
 626        } else {
 627                pgio->pg_layout_private = (void *)
 628                                OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
 629        }
 630}
 631
 632static const struct nfs_pageio_ops objio_pg_read_ops = {
 633        .pg_init = objio_init_read,
 634        .pg_test = objio_pg_test,
 635        .pg_doio = pnfs_generic_pg_readpages,
 636};
 637
 638static const struct nfs_pageio_ops objio_pg_write_ops = {
 639        .pg_init = objio_init_write,
 640        .pg_test = objio_pg_test,
 641        .pg_doio = pnfs_generic_pg_writepages,
 642};
 643
 644static struct pnfs_layoutdriver_type objlayout_type = {
 645        .id = LAYOUT_OSD2_OBJECTS,
 646        .name = "LAYOUT_OSD2_OBJECTS",
 647        .flags                   = PNFS_LAYOUTRET_ON_SETATTR |
 648                                   PNFS_LAYOUTRET_ON_ERROR,
 649
 650        .owner                   = THIS_MODULE,
 651        .alloc_layout_hdr        = objlayout_alloc_layout_hdr,
 652        .free_layout_hdr         = objlayout_free_layout_hdr,
 653
 654        .alloc_lseg              = objlayout_alloc_lseg,
 655        .free_lseg               = objlayout_free_lseg,
 656
 657        .read_pagelist           = objlayout_read_pagelist,
 658        .write_pagelist          = objlayout_write_pagelist,
 659        .pg_read_ops             = &objio_pg_read_ops,
 660        .pg_write_ops            = &objio_pg_write_ops,
 661
 662        .free_deviceid_node      = objio_free_deviceid_node,
 663
 664        .encode_layoutcommit     = objlayout_encode_layoutcommit,
 665        .encode_layoutreturn     = objlayout_encode_layoutreturn,
 666};
 667
 668MODULE_DESCRIPTION("pNFS Layout Driver for OSD2 objects");
 669MODULE_AUTHOR("Benny Halevy <bhalevy@panasas.com>");
 670MODULE_LICENSE("GPL");
 671
 672static int __init
 673objlayout_init(void)
 674{
 675        int ret = pnfs_register_layoutdriver(&objlayout_type);
 676
 677        if (ret)
 678                printk(KERN_INFO
 679                        "NFS: %s: Registering OSD pNFS Layout Driver failed: error=%d\n",
 680                        __func__, ret);
 681        else
 682                printk(KERN_INFO "NFS: %s: Registered OSD pNFS Layout Driver\n",
 683                        __func__);
 684        return ret;
 685}
 686
 687static void __exit
 688objlayout_exit(void)
 689{
 690        pnfs_unregister_layoutdriver(&objlayout_type);
 691        printk(KERN_INFO "NFS: %s: Unregistered OSD pNFS Layout Driver\n",
 692               __func__);
 693}
 694
 695MODULE_ALIAS("nfs-layouttype4-2");
 696
 697module_init(objlayout_init);
 698module_exit(objlayout_exit);
 699