fs/nfs/blocklayout/blocklayout.c

   1 /*
   2  *  linux/fs/nfs/blocklayout/blocklayout.c
   3  *
   4  *  Module for the NFSv4.1 pNFS block layout driver.
   5  *
   6  *  Copyright (c) 2006 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Andy Adamson <andros@citi.umich.edu>
  10  *  Fred Isaman <iisaman@umich.edu>
  11  *
  12  * permission is granted to use, copy, create derivative works and
  13  * redistribute this software and such derivative works for any purpose,
  14  * so long as the name of the university of michigan is not used in
  15  * any advertising or publicity pertaining to the use or distribution
  16  * of this software without specific, written prior authorization.  if
  17  * the above copyright notice or any other identification of the
  18  * university of michigan is included in any copy of any portion of
  19  * this software, then the disclaimer below must also be included.
  20  *
  21  * this software is provided as is, without representation from the
  22  * university of michigan as to its fitness for any purpose, and without
  23  * warranty by the university of michigan of any kind, either express
  24  * or implied, including without limitation the implied warranties of
  25  * merchantability and fitness for a particular purpose.  the regents
  26  * of the university of michigan shall not be liable for any damages,
  27  * including special, indirect, incidental, or consequential damages,
  28  * with respect to any claim arising out or in connection with the use
  29  * of the software, even if it has been or is hereafter advised of the
  30  * possibility of such damages.
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/mount.h>
  36 #include <linux/namei.h>
  37 #include <linux/bio.h>          /* struct bio */
  38 #include <linux/buffer_head.h>  /* various write calls */
  39 #include <linux/prefetch.h>
  40 #include <linux/pagevec.h>
  41
  42 #include "../pnfs.h"
  43 #include "../nfs4session.h"
  44 #include "../internal.h"
  45 #include "blocklayout.h"
  46
  47 #define NFSDBG_FACILITY NFSDBG_PNFS_LD
  48
  49 MODULE_LICENSE("GPL");
  50 MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
  51 MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
  52
  53 static void print_page(struct page *page)
  54 {
  55         dprintk("PRINTPAGE page %p\n", page);
  56         dprintk("       PagePrivate %d\n", PagePrivate(page));
  57         dprintk("       PageUptodate %d\n", PageUptodate(page));
  58         dprintk("       PageError %d\n", PageError(page));
  59         dprintk("       PageDirty %d\n", PageDirty(page));
  60         dprintk("       PageReferenced %d\n", PageReferenced(page));
  61         dprintk("       PageLocked %d\n", PageLocked(page));
  62         dprintk("       PageWriteback %d\n", PageWriteback(page));
  63         dprintk("       PageMappedToDisk %d\n", PageMappedToDisk(page));
  64         dprintk("\n");
  65 }
  66
  67 /* Given the be associated with isect, determine if page data needs to be
  68  * initialized.
  69  */
  70 static int is_hole(struct pnfs_block_extent *be, sector_t isect)
  71 {
  72         if (be->be_state == PNFS_BLOCK_NONE_DATA)
  73                 return 1;
  74         else if (be->be_state != PNFS_BLOCK_INVALID_DATA)
  75                 return 0;
  76         else
  77                 return !bl_is_sector_init(be->be_inval, isect);
  78 }
  79
  80 /* Given the be associated with isect, determine if page data can be
  81  * written to disk.
  82  */
  83 static int is_writable(struct pnfs_block_extent *be, sector_t isect)
  84 {
  85         return (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
  86                 be->be_state == PNFS_BLOCK_INVALID_DATA);
  87 }
  88
  89 /* The data we are handed might be spread across several bios.  We need
  90  * to track when the last one is finished.
  91  */
  92 struct parallel_io {
  93         struct kref refcnt;
  94         void (*pnfs_callback) (void *data, int num_se);
  95         void *data;
  96         int bse_count;
  97 };
  98
  99 static inline struct parallel_io *alloc_parallel(void *data)
 100 {
 101         struct parallel_io *rv;
 102
 103         rv  = kmalloc(sizeof(*rv), GFP_NOFS);
 104         if (rv) {
 105                 rv->data = data;
 106                 kref_init(&rv->refcnt);
 107                 rv->bse_count = 0;
 108         }
 109         return rv;
 110 }
 111
 112 static inline void get_parallel(struct parallel_io *p)
 113 {
 114         kref_get(&p->refcnt);
 115 }
 116
 117 static void destroy_parallel(struct kref *kref)
 118 {
 119         struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
 120
 121         dprintk("%s enter\n", __func__);
 122         p->pnfs_callback(p->data, p->bse_count);
 123         kfree(p);
 124 }
 125
 126 static inline void put_parallel(struct parallel_io *p)
 127 {
 128         kref_put(&p->refcnt, destroy_parallel);
 129 }
 130
 131 static struct bio *
 132 bl_submit_bio(int rw, struct bio *bio)
 133 {
 134         if (bio) {
 135                 get_parallel(bio->bi_private);
 136                 dprintk("%s submitting %s bio %u@%llu\n", __func__,
 137                         rw == READ ? "read" : "write",
 138                         bio->bi_size, (unsigned long long)bio->bi_sector);
 139                 submit_bio(rw, bio);
 140         }
 141         return NULL;
 142 }
 143
 144 static struct bio *bl_alloc_init_bio(int npg, sector_t isect,
 145                                      struct pnfs_block_extent *be,
 146                                      void (*end_io)(struct bio *, int err),
 147                                      struct parallel_io *par)
 148 {
 149         struct bio *bio;
 150
 151         npg = min(npg, BIO_MAX_PAGES);
 152         bio = bio_alloc(GFP_NOIO, npg);
 153         if (!bio && (current->flags & PF_MEMALLOC)) {
 154                 while (!bio && (npg /= 2))
 155                         bio = bio_alloc(GFP_NOIO, npg);
 156         }
 157
 158         if (bio) {
 159                 bio->bi_sector = isect - be->be_f_offset + be->be_v_offset;
 160                 bio->bi_bdev = be->be_mdev;
 161                 bio->bi_end_io = end_io;
 162                 bio->bi_private = par;
 163         }
 164         return bio;
 165 }
 166
 167 static struct bio *do_add_page_to_bio(struct bio *bio, int npg, int rw,
 168                                       sector_t isect, struct page *page,
 169                                       struct pnfs_block_extent *be,
 170                                       void (*end_io)(struct bio *, int err),
 171                                       struct parallel_io *par,
 172                                       unsigned int offset, int len)
 173 {
 174         isect = isect + (offset >> SECTOR_SHIFT);
 175         dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
 176                 npg, rw, (unsigned long long)isect, offset, len);
 177 retry:
 178         if (!bio) {
 179                 bio = bl_alloc_init_bio(npg, isect, be, end_io, par);
 180                 if (!bio)
 181                         return ERR_PTR(-ENOMEM);
 182         }
 183         if (bio_add_page(bio, page, len, offset) < len) {
 184                 bio = bl_submit_bio(rw, bio);
 185                 goto retry;
 186         }
 187         return bio;
 188 }
 189
 190 static struct bio *bl_add_page_to_bio(struct bio *bio, int npg, int rw,
 191                                       sector_t isect, struct page *page,
 192                                       struct pnfs_block_extent *be,
 193                                       void (*end_io)(struct bio *, int err),
 194                                       struct parallel_io *par)
 195 {
 196         return do_add_page_to_bio(bio, npg, rw, isect, page, be,
 197                                   end_io, par, 0, PAGE_CACHE_SIZE);
 198 }
 199
 200 /* This is basically copied from mpage_end_io_read */
 201 static void bl_end_io_read(struct bio *bio, int err)
 202 {
 203         struct parallel_io *par = bio->bi_private;
 204         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 205         struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 206
 207         do {
 208                 struct page *page = bvec->bv_page;
 209
 210                 if (--bvec >= bio->bi_io_vec)
 211                         prefetchw(&bvec->bv_page->flags);
 212                 if (uptodate)
 213                         SetPageUptodate(page);
 214         } while (bvec >= bio->bi_io_vec);
 215         if (!uptodate) {
 216                 struct nfs_read_data *rdata = par->data;
 217                 struct nfs_pgio_header *header = rdata->header;
 218
 219                 if (!header->pnfs_error)
 220                         header->pnfs_error = -EIO;
 221                 pnfs_set_lo_fail(header->lseg);
 222         }
 223         bio_put(bio);
 224         put_parallel(par);
 225 }
 226
 227 static void bl_read_cleanup(struct work_struct *work)
 228 {
 229         struct rpc_task *task;
 230         struct nfs_read_data *rdata;
 231         dprintk("%s enter\n", __func__);
 232         task = container_of(work, struct rpc_task, u.tk_work);
 233         rdata = container_of(task, struct nfs_read_data, task);
 234         pnfs_ld_read_done(rdata);
 235 }
 236
 237 static void
 238 bl_end_par_io_read(void *data, int unused)
 239 {
 240         struct nfs_read_data *rdata = data;
 241
 242         rdata->task.tk_status = rdata->header->pnfs_error;
 243         INIT_WORK(&rdata->task.u.tk_work, bl_read_cleanup);
 244         schedule_work(&rdata->task.u.tk_work);
 245 }
 246
 247 static enum pnfs_try_status
 248 bl_read_pagelist(struct nfs_read_data *rdata)
 249 {
 250         struct nfs_pgio_header *header = rdata->header;
 251         int i, hole;
 252         struct bio *bio = NULL;
 253         struct pnfs_block_extent *be = NULL, *cow_read = NULL;
 254         sector_t isect, extent_length = 0;
 255         struct parallel_io *par;
 256         loff_t f_offset = rdata->args.offset;
 257         size_t bytes_left = rdata->args.count;
 258         unsigned int pg_offset, pg_len;
 259         struct page **pages = rdata->args.pages;
 260         int pg_index = rdata->args.pgbase >> PAGE_CACHE_SHIFT;
 261         const bool is_dio = (header->dreq != NULL);
 262
 263         dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
 264                rdata->pages.npages, f_offset, (unsigned int)rdata->args.count);
 265
 266         par = alloc_parallel(rdata);
 267         if (!par)
 268                 goto use_mds;
 269         par->pnfs_callback = bl_end_par_io_read;
 270         /* At this point, we can no longer jump to use_mds */
 271
 272         isect = (sector_t) (f_offset >> SECTOR_SHIFT);
 273         /* Code assumes extents are page-aligned */
 274         for (i = pg_index; i < rdata->pages.npages; i++) {
 275                 if (!extent_length) {
 276                         /* We've used up the previous extent */
 277                         bl_put_extent(be);
 278                         bl_put_extent(cow_read);
 279                         bio = bl_submit_bio(READ, bio);
 280                         /* Get the next one */
 281                         be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg),
 282                                              isect, &cow_read);
 283                         if (!be) {
 284                                 header->pnfs_error = -EIO;
 285                                 goto out;
 286                         }
 287                         extent_length = be->be_length -
 288                                 (isect - be->be_f_offset);
 289                         if (cow_read) {
 290                                 sector_t cow_length = cow_read->be_length -
 291                                         (isect - cow_read->be_f_offset);
 292                                 extent_length = min(extent_length, cow_length);
 293                         }
 294                 }
 295
 296                 if (is_dio) {
 297                         pg_offset = f_offset & ~PAGE_CACHE_MASK;
 298                         if (pg_offset + bytes_left > PAGE_CACHE_SIZE)
 299                                 pg_len = PAGE_CACHE_SIZE - pg_offset;
 300                         else
 301                                 pg_len = bytes_left;
 302
 303                         f_offset += pg_len;
 304                         bytes_left -= pg_len;
 305                         isect += (pg_offset >> SECTOR_SHIFT);
 306                 } else {
 307                         pg_offset = 0;
 308                         pg_len = PAGE_CACHE_SIZE;
 309                 }
 310
 311                 hole = is_hole(be, isect);
 312                 if (hole && !cow_read) {
 313                         bio = bl_submit_bio(READ, bio);
 314                         /* Fill hole w/ zeroes w/o accessing device */
 315                         dprintk("%s Zeroing page for hole\n", __func__);
 316                         zero_user_segment(pages[i], pg_offset, pg_len);
 317                         print_page(pages[i]);
 318                         SetPageUptodate(pages[i]);
 319                 } else {
 320                         struct pnfs_block_extent *be_read;
 321
 322                         be_read = (hole && cow_read) ? cow_read : be;
 323                         bio = do_add_page_to_bio(bio, rdata->pages.npages - i,
 324                                                  READ,
 325                                                  isect, pages[i], be_read,
 326                                                  bl_end_io_read, par,
 327                                                  pg_offset, pg_len);
 328                         if (IS_ERR(bio)) {
 329                                 header->pnfs_error = PTR_ERR(bio);
 330                                 bio = NULL;
 331                                 goto out;
 332                         }
 333                 }
 334                 isect += (pg_len >> SECTOR_SHIFT);
 335                 extent_length -= PAGE_CACHE_SECTORS;
 336         }
 337         if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
 338                 rdata->res.eof = 1;
 339                 rdata->res.count = header->inode->i_size - rdata->args.offset;
 340         } else {
 341                 rdata->res.count = (isect << SECTOR_SHIFT) - rdata->args.offset;
 342         }
 343 out:
 344         bl_put_extent(be);
 345         bl_put_extent(cow_read);
 346         bl_submit_bio(READ, bio);
 347         put_parallel(par);
 348         return PNFS_ATTEMPTED;
 349
 350  use_mds:
 351         dprintk("Giving up and using normal NFS\n");
 352         return PNFS_NOT_ATTEMPTED;
 353 }
 354
 355 static void mark_extents_written(struct pnfs_block_layout *bl,
 356                                  __u64 offset, __u32 count)
 357 {
 358         sector_t isect, end;
 359         struct pnfs_block_extent *be;
 360         struct pnfs_block_short_extent *se;
 361
 362         dprintk("%s(%llu, %u)\n", __func__, offset, count);
 363         if (count == 0)
 364                 return;
 365         isect = (offset & (long)(PAGE_CACHE_MASK)) >> SECTOR_SHIFT;
 366         end = (offset + count + PAGE_CACHE_SIZE - 1) & (long)(PAGE_CACHE_MASK);
 367         end >>= SECTOR_SHIFT;
 368         while (isect < end) {
 369                 sector_t len;
 370                 be = bl_find_get_extent(bl, isect, NULL);
 371                 BUG_ON(!be); /* FIXME */
 372                 len = min(end, be->be_f_offset + be->be_length) - isect;
 373                 if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 374                         se = bl_pop_one_short_extent(be->be_inval);
 375                         BUG_ON(!se);
 376                         bl_mark_for_commit(be, isect, len, se);
 377                 }
 378                 isect += len;
 379                 bl_put_extent(be);
 380         }
 381 }
 382
 383 static void bl_end_io_write_zero(struct bio *bio, int err)
 384 {
 385         struct parallel_io *par = bio->bi_private;
 386         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 387         struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 388
 389         do {
 390                 struct page *page = bvec->bv_page;
 391
 392                 if (--bvec >= bio->bi_io_vec)
 393                         prefetchw(&bvec->bv_page->flags);
 394                 /* This is the zeroing page we added */
 395                 end_page_writeback(page);
 396                 page_cache_release(page);
 397         } while (bvec >= bio->bi_io_vec);
 398
 399         if (unlikely(!uptodate)) {
 400                 struct nfs_write_data *data = par->data;
 401                 struct nfs_pgio_header *header = data->header;
 402
 403                 if (!header->pnfs_error)
 404                         header->pnfs_error = -EIO;
 405                 pnfs_set_lo_fail(header->lseg);
 406         }
 407         bio_put(bio);
 408         put_parallel(par);
 409 }
 410
 411 static void bl_end_io_write(struct bio *bio, int err)
 412 {
 413         struct parallel_io *par = bio->bi_private;
 414         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 415         struct nfs_write_data *data = par->data;
 416         struct nfs_pgio_header *header = data->header;
 417
 418         if (!uptodate) {
 419                 if (!header->pnfs_error)
 420                         header->pnfs_error = -EIO;
 421                 pnfs_set_lo_fail(header->lseg);
 422         }
 423         bio_put(bio);
 424         put_parallel(par);
 425 }
 426
 427 /* Function scheduled for call during bl_end_par_io_write,
 428  * it marks sectors as written and extends the commitlist.
 429  */
 430 static void bl_write_cleanup(struct work_struct *work)
 431 {
 432         struct rpc_task *task;
 433         struct nfs_write_data *wdata;
 434         dprintk("%s enter\n", __func__);
 435         task = container_of(work, struct rpc_task, u.tk_work);
 436         wdata = container_of(task, struct nfs_write_data, task);
 437         if (likely(!wdata->header->pnfs_error)) {
 438                 /* Marks for LAYOUTCOMMIT */
 439                 mark_extents_written(BLK_LSEG2EXT(wdata->header->lseg),
 440                                      wdata->args.offset, wdata->args.count);
 441         }
 442         pnfs_ld_write_done(wdata);
 443 }
 444
 445 /* Called when last of bios associated with a bl_write_pagelist call finishes */
 446 static void bl_end_par_io_write(void *data, int num_se)
 447 {
 448         struct nfs_write_data *wdata = data;
 449
 450         if (unlikely(wdata->header->pnfs_error)) {
 451                 bl_free_short_extents(&BLK_LSEG2EXT(wdata->header->lseg)->bl_inval,
 452                                         num_se);
 453         }
 454
 455         wdata->task.tk_status = wdata->header->pnfs_error;
 456         wdata->verf.committed = NFS_FILE_SYNC;
 457         INIT_WORK(&wdata->task.u.tk_work, bl_write_cleanup);
 458         schedule_work(&wdata->task.u.tk_work);
 459 }
 460
 461 /* FIXME STUB - mark intersection of layout and page as bad, so is not
 462  * used again.
 463  */
 464 static void mark_bad_read(void)
 465 {
 466         return;
 467 }
 468
 469 /*
 470  * map_block:  map a requested I/0 block (isect) into an offset in the LVM
 471  * block_device
 472  */
 473 static void
 474 map_block(struct buffer_head *bh, sector_t isect, struct pnfs_block_extent *be)
 475 {
 476         dprintk("%s enter be=%p\n", __func__, be);
 477
 478         set_buffer_mapped(bh);
 479         bh->b_bdev = be->be_mdev;
 480         bh->b_blocknr = (isect - be->be_f_offset + be->be_v_offset) >>
 481             (be->be_mdev->bd_inode->i_blkbits - SECTOR_SHIFT);
 482
 483         dprintk("%s isect %llu, bh->b_blocknr %ld, using bsize %Zd\n",
 484                 __func__, (unsigned long long)isect, (long)bh->b_blocknr,
 485                 bh->b_size);
 486         return;
 487 }
 488
 489 static void
 490 bl_read_single_end_io(struct bio *bio, int error)
 491 {
 492         struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 493         struct page *page = bvec->bv_page;
 494
 495         /* Only one page in bvec */
 496         unlock_page(page);
 497 }
 498
 499 static int
 500 bl_do_readpage_sync(struct page *page, struct pnfs_block_extent *be,
 501                     unsigned int offset, unsigned int len)
 502 {
 503         struct bio *bio;
 504         struct page *shadow_page;
 505         sector_t isect;
 506         char *kaddr, *kshadow_addr;
 507         int ret = 0;
 508
 509         dprintk("%s: offset %u len %u\n", __func__, offset, len);
 510
 511         shadow_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
 512         if (shadow_page == NULL)
 513                 return -ENOMEM;
 514
 515         bio = bio_alloc(GFP_NOIO, 1);
 516         if (bio == NULL)
 517                 return -ENOMEM;
 518
 519         isect = (page->index << PAGE_CACHE_SECTOR_SHIFT) +
 520                 (offset / SECTOR_SIZE);
 521
 522         bio->bi_sector = isect - be->be_f_offset + be->be_v_offset;
 523         bio->bi_bdev = be->be_mdev;
 524         bio->bi_end_io = bl_read_single_end_io;
 525
 526         lock_page(shadow_page);
 527         if (bio_add_page(bio, shadow_page,
 528                          SECTOR_SIZE, round_down(offset, SECTOR_SIZE)) == 0) {
 529                 unlock_page(shadow_page);
 530                 bio_put(bio);
 531                 return -EIO;
 532         }
 533
 534         submit_bio(READ, bio);
 535         wait_on_page_locked(shadow_page);
 536         if (unlikely(!test_bit(BIO_UPTODATE, &bio->bi_flags))) {
 537                 ret = -EIO;
 538         } else {
 539                 kaddr = kmap_atomic(page);
 540                 kshadow_addr = kmap_atomic(shadow_page);
 541                 memcpy(kaddr + offset, kshadow_addr + offset, len);
 542                 kunmap_atomic(kshadow_addr);
 543                 kunmap_atomic(kaddr);
 544         }
 545         __free_page(shadow_page);
 546         bio_put(bio);
 547
 548         return ret;
 549 }
 550
 551 static int
 552 bl_read_partial_page_sync(struct page *page, struct pnfs_block_extent *be,
 553                           unsigned int dirty_offset, unsigned int dirty_len,
 554                           bool full_page)
 555 {
 556         int ret = 0;
 557         unsigned int start, end;
 558
 559         if (full_page) {
 560                 start = 0;
 561                 end = PAGE_CACHE_SIZE;
 562         } else {
 563                 start = round_down(dirty_offset, SECTOR_SIZE);
 564                 end = round_up(dirty_offset + dirty_len, SECTOR_SIZE);
 565         }
 566
 567         dprintk("%s: offset %u len %d\n", __func__, dirty_offset, dirty_len);
 568         if (!be) {
 569                 zero_user_segments(page, start, dirty_offset,
 570                                    dirty_offset + dirty_len, end);
 571                 if (start == 0 && end == PAGE_CACHE_SIZE &&
 572                     trylock_page(page)) {
 573                         SetPageUptodate(page);
 574                         unlock_page(page);
 575                 }
 576                 return ret;
 577         }
 578
 579         if (start != dirty_offset)
 580                 ret = bl_do_readpage_sync(page, be, start, dirty_offset - start);
 581
 582         if (!ret && (dirty_offset + dirty_len < end))
 583                 ret = bl_do_readpage_sync(page, be, dirty_offset + dirty_len,
 584                                           end - dirty_offset - dirty_len);
 585
 586         return ret;
 587 }
 588
 589 /* Given an unmapped page, zero it or read in page for COW, page is locked
 590  * by caller.
 591  */
 592 static int
 593 init_page_for_write(struct page *page, struct pnfs_block_extent *cow_read)
 594 {
 595         struct buffer_head *bh = NULL;
 596         int ret = 0;
 597         sector_t isect;
 598
 599         dprintk("%s enter, %p\n", __func__, page);
 600         BUG_ON(PageUptodate(page));
 601         if (!cow_read) {
 602                 zero_user_segment(page, 0, PAGE_SIZE);
 603                 SetPageUptodate(page);
 604                 goto cleanup;
 605         }
 606
 607         bh = alloc_page_buffers(page, PAGE_CACHE_SIZE, 0);
 608         if (!bh) {
 609                 ret = -ENOMEM;
 610                 goto cleanup;
 611         }
 612
 613         isect = (sector_t) page->index << PAGE_CACHE_SECTOR_SHIFT;
 614         map_block(bh, isect, cow_read);
 615         if (!bh_uptodate_or_lock(bh))
 616                 ret = bh_submit_read(bh);
 617         if (ret)
 618                 goto cleanup;
 619         SetPageUptodate(page);
 620
 621 cleanup:
 622         if (bh)
 623                 free_buffer_head(bh);
 624         if (ret) {
 625                 /* Need to mark layout with bad read...should now
 626                  * just use nfs4 for reads and writes.
 627                  */
 628                 mark_bad_read();
 629         }
 630         return ret;
 631 }
 632
 633 /* Find or create a zeroing page marked being writeback.
 634  * Return ERR_PTR on error, NULL to indicate skip this page and page itself
 635  * to indicate write out.
 636  */
 637 static struct page *
 638 bl_find_get_zeroing_page(struct inode *inode, pgoff_t index,
 639                         struct pnfs_block_extent *cow_read)
 640 {
 641         struct page *page;
 642         int locked = 0;
 643         page = find_get_page(inode->i_mapping, index);
 644         if (page)
 645                 goto check_page;
 646
 647         page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
 648         if (unlikely(!page)) {
 649                 dprintk("%s oom\n", __func__);
 650                 return ERR_PTR(-ENOMEM);
 651         }
 652         locked = 1;
 653
 654 check_page:
 655         /* PageDirty: Other will write this out
 656          * PageWriteback: Other is writing this out
 657          * PageUptodate: It was read before
 658          */
 659         if (PageDirty(page) || PageWriteback(page)) {
 660                 print_page(page);
 661                 if (locked)
 662                         unlock_page(page);
 663                 page_cache_release(page);
 664                 return NULL;
 665         }
 666
 667         if (!locked) {
 668                 lock_page(page);
 669                 locked = 1;
 670                 goto check_page;
 671         }
 672         if (!PageUptodate(page)) {
 673                 /* New page, readin or zero it */
 674                 init_page_for_write(page, cow_read);
 675         }
 676         set_page_writeback(page);
 677         unlock_page(page);
 678
 679         return page;
 680 }
 681
 682 static enum pnfs_try_status
 683 bl_write_pagelist(struct nfs_write_data *wdata, int sync)
 684 {
 685         struct nfs_pgio_header *header = wdata->header;
 686         int i, ret, npg_zero, pg_index, last = 0;
 687         struct bio *bio = NULL;
 688         struct pnfs_block_extent *be = NULL, *cow_read = NULL;
 689         sector_t isect, last_isect = 0, extent_length = 0;
 690         struct parallel_io *par = NULL;
 691         loff_t offset = wdata->args.offset;
 692         size_t count = wdata->args.count;
 693         unsigned int pg_offset, pg_len, saved_len;
 694         struct page **pages = wdata->args.pages;
 695         struct page *page;
 696         pgoff_t index;
 697         u64 temp;
 698         int npg_per_block =
 699             NFS_SERVER(header->inode)->pnfs_blksize >> PAGE_CACHE_SHIFT;
 700
 701         dprintk("%s enter, %Zu@%lld\n", __func__, count, offset);
 702
 703         if (header->dreq != NULL &&
 704             (!IS_ALIGNED(offset, NFS_SERVER(header->inode)->pnfs_blksize) ||
 705              !IS_ALIGNED(count, NFS_SERVER(header->inode)->pnfs_blksize))) {
 706                 dprintk("pnfsblock nonblock aligned DIO writes. Resend MDS\n");
 707                 goto out_mds;
 708         }
 709         /* At this point, wdata->pages is a (sequential) list of nfs_pages.
 710          * We want to write each, and if there is an error set pnfs_error
 711          * to have it redone using nfs.
 712          */
 713         par = alloc_parallel(wdata);
 714         if (!par)
 715                 goto out_mds;
 716         par->pnfs_callback = bl_end_par_io_write;
 717         /* At this point, have to be more careful with error handling */
 718
 719         isect = (sector_t) ((offset & (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
 720         be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg), isect, &cow_read);
 721         if (!be || !is_writable(be, isect)) {
 722                 dprintk("%s no matching extents!\n", __func__);
 723                 goto out_mds;
 724         }
 725
 726         /* First page inside INVALID extent */
 727         if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 728                 if (likely(!bl_push_one_short_extent(be->be_inval)))
 729                         par->bse_count++;
 730                 else
 731                         goto out_mds;
 732                 temp = offset >> PAGE_CACHE_SHIFT;
 733                 npg_zero = do_div(temp, npg_per_block);
 734                 isect = (sector_t) (((offset - npg_zero * PAGE_CACHE_SIZE) &
 735                                      (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
 736                 extent_length = be->be_length - (isect - be->be_f_offset);
 737
 738 fill_invalid_ext:
 739                 dprintk("%s need to zero %d pages\n", __func__, npg_zero);
 740                 for (;npg_zero > 0; npg_zero--) {
 741                         if (bl_is_sector_init(be->be_inval, isect)) {
 742                                 dprintk("isect %llu already init\n",
 743                                         (unsigned long long)isect);
 744                                 goto next_page;
 745                         }
 746                         /* page ref released in bl_end_io_write_zero */
 747                         index = isect >> PAGE_CACHE_SECTOR_SHIFT;
 748                         dprintk("%s zero %dth page: index %lu isect %llu\n",
 749                                 __func__, npg_zero, index,
 750                                 (unsigned long long)isect);
 751                         page = bl_find_get_zeroing_page(header->inode, index,
 752                                                         cow_read);
 753                         if (unlikely(IS_ERR(page))) {
 754                                 header->pnfs_error = PTR_ERR(page);
 755                                 goto out;
 756                         } else if (page == NULL)
 757                                 goto next_page;
 758
 759                         ret = bl_mark_sectors_init(be->be_inval, isect,
 760                                                        PAGE_CACHE_SECTORS);
 761                         if (unlikely(ret)) {
 762                                 dprintk("%s bl_mark_sectors_init fail %d\n",
 763                                         __func__, ret);
 764                                 end_page_writeback(page);
 765                                 page_cache_release(page);
 766                                 header->pnfs_error = ret;
 767                                 goto out;
 768                         }
 769                         if (likely(!bl_push_one_short_extent(be->be_inval)))
 770                                 par->bse_count++;
 771                         else {
 772                                 end_page_writeback(page);
 773                                 page_cache_release(page);
 774                                 header->pnfs_error = -ENOMEM;
 775                                 goto out;
 776                         }
 777                         /* FIXME: This should be done in bi_end_io */
 778                         mark_extents_written(BLK_LSEG2EXT(header->lseg),
 779                                              page->index << PAGE_CACHE_SHIFT,
 780                                              PAGE_CACHE_SIZE);
 781
 782                         bio = bl_add_page_to_bio(bio, npg_zero, WRITE,
 783                                                  isect, page, be,
 784                                                  bl_end_io_write_zero, par);
 785                         if (IS_ERR(bio)) {
 786                                 header->pnfs_error = PTR_ERR(bio);
 787                                 bio = NULL;
 788                                 goto out;
 789                         }
 790 next_page:
 791                         isect += PAGE_CACHE_SECTORS;
 792                         extent_length -= PAGE_CACHE_SECTORS;
 793                 }
 794                 if (last)
 795                         goto write_done;
 796         }
 797         bio = bl_submit_bio(WRITE, bio);
 798
 799         /* Middle pages */
 800         pg_index = wdata->args.pgbase >> PAGE_CACHE_SHIFT;
 801         for (i = pg_index; i < wdata->pages.npages; i++) {
 802                 if (!extent_length) {
 803                         /* We've used up the previous extent */
 804                         bl_put_extent(be);
 805                         bl_put_extent(cow_read);
 806                         bio = bl_submit_bio(WRITE, bio);
 807                         /* Get the next one */
 808                         be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg),
 809                                              isect, &cow_read);
 810                         if (!be || !is_writable(be, isect)) {
 811                                 header->pnfs_error = -EINVAL;
 812                                 goto out;
 813                         }
 814                         if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 815                                 if (likely(!bl_push_one_short_extent(
 816                                                                 be->be_inval)))
 817                                         par->bse_count++;
 818                                 else {
 819                                         header->pnfs_error = -ENOMEM;
 820                                         goto out;
 821                                 }
 822                         }
 823                         extent_length = be->be_length -
 824                             (isect - be->be_f_offset);
 825                 }
 826
 827                 dprintk("%s offset %lld count %Zu\n", __func__, offset, count);
 828                 pg_offset = offset & ~PAGE_CACHE_MASK;
 829                 if (pg_offset + count > PAGE_CACHE_SIZE)
 830                         pg_len = PAGE_CACHE_SIZE - pg_offset;
 831                 else
 832                         pg_len = count;
 833
 834                 saved_len = pg_len;
 835                 if (be->be_state == PNFS_BLOCK_INVALID_DATA &&
 836                     !bl_is_sector_init(be->be_inval, isect)) {
 837                         ret = bl_read_partial_page_sync(pages[i], cow_read,
 838                                                         pg_offset, pg_len, true);
 839                         if (ret) {
 840                                 dprintk("%s bl_read_partial_page_sync fail %d\n",
 841                                         __func__, ret);
 842                                 header->pnfs_error = ret;
 843                                 goto out;
 844                         }
 845
 846                         ret = bl_mark_sectors_init(be->be_inval, isect,
 847                                                        PAGE_CACHE_SECTORS);
 848                         if (unlikely(ret)) {
 849                                 dprintk("%s bl_mark_sectors_init fail %d\n",
 850                                         __func__, ret);
 851                                 header->pnfs_error = ret;
 852                                 goto out;
 853                         }
 854
 855                         /* Expand to full page write */
 856                         pg_offset = 0;
 857                         pg_len = PAGE_CACHE_SIZE;
 858                 } else if  ((pg_offset & (SECTOR_SIZE - 1)) ||
 859                             (pg_len & (SECTOR_SIZE - 1))){
 860                         /* ahh, nasty case. We have to do sync full sector
 861                          * read-modify-write cycles.
 862                          */
 863                         unsigned int saved_offset = pg_offset;
 864                         ret = bl_read_partial_page_sync(pages[i], be, pg_offset,
 865                                                         pg_len, false);
 866                         pg_offset = round_down(pg_offset, SECTOR_SIZE);
 867                         pg_len = round_up(saved_offset + pg_len, SECTOR_SIZE)
 868                                  - pg_offset;
 869                 }
 870
 871
 872                 bio = do_add_page_to_bio(bio, wdata->pages.npages - i, WRITE,
 873                                          isect, pages[i], be,
 874                                          bl_end_io_write, par,
 875                                          pg_offset, pg_len);
 876                 if (IS_ERR(bio)) {
 877                         header->pnfs_error = PTR_ERR(bio);
 878                         bio = NULL;
 879                         goto out;
 880                 }
 881                 offset += saved_len;
 882                 count -= saved_len;
 883                 isect += PAGE_CACHE_SECTORS;
 884                 last_isect = isect;
 885                 extent_length -= PAGE_CACHE_SECTORS;
 886         }
 887
 888         /* Last page inside INVALID extent */
 889         if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 890                 bio = bl_submit_bio(WRITE, bio);
 891                 temp = last_isect >> PAGE_CACHE_SECTOR_SHIFT;
 892                 npg_zero = npg_per_block - do_div(temp, npg_per_block);
 893                 if (npg_zero < npg_per_block) {
 894                         last = 1;
 895                         goto fill_invalid_ext;
 896                 }
 897         }
 898
 899 write_done:
 900         wdata->res.count = wdata->args.count;
 901 out:
 902         bl_put_extent(be);
 903         bl_put_extent(cow_read);
 904         bl_submit_bio(WRITE, bio);
 905         put_parallel(par);
 906         return PNFS_ATTEMPTED;
 907 out_mds:
 908         bl_put_extent(be);
 909         bl_put_extent(cow_read);
 910         kfree(par);
 911         return PNFS_NOT_ATTEMPTED;
 912 }
 913
 914 /* FIXME - range ignored */
 915 static void
 916 release_extents(struct pnfs_block_layout *bl, struct pnfs_layout_range *range)
 917 {
 918         int i;
 919         struct pnfs_block_extent *be;
 920
 921         spin_lock(&bl->bl_ext_lock);
 922         for (i = 0; i < EXTENT_LISTS; i++) {
 923                 while (!list_empty(&bl->bl_extents[i])) {
 924                         be = list_first_entry(&bl->bl_extents[i],
 925                                               struct pnfs_block_extent,
 926                                               be_node);
 927                         list_del(&be->be_node);
 928                         bl_put_extent(be);
 929                 }
 930         }
 931         spin_unlock(&bl->bl_ext_lock);
 932 }
 933
 934 static void
 935 release_inval_marks(struct pnfs_inval_markings *marks)
 936 {
 937         struct pnfs_inval_tracking *pos, *temp;
 938         struct pnfs_block_short_extent *se, *stemp;
 939
 940         list_for_each_entry_safe(pos, temp, &marks->im_tree.mtt_stub, it_link) {
 941                 list_del(&pos->it_link);
 942                 kfree(pos);
 943         }
 944
 945         list_for_each_entry_safe(se, stemp, &marks->im_extents, bse_node) {
 946                 list_del(&se->bse_node);
 947                 kfree(se);
 948         }
 949         return;
 950 }
 951
 952 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
 953 {
 954         struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
 955
 956         dprintk("%s enter\n", __func__);
 957         release_extents(bl, NULL);
 958         release_inval_marks(&bl->bl_inval);
 959         kfree(bl);
 960 }
 961
 962 static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
 963                                                    gfp_t gfp_flags)
 964 {
 965         struct pnfs_block_layout *bl;
 966
 967         dprintk("%s enter\n", __func__);
 968         bl = kzalloc(sizeof(*bl), gfp_flags);
 969         if (!bl)
 970                 return NULL;
 971         spin_lock_init(&bl->bl_ext_lock);
 972         INIT_LIST_HEAD(&bl->bl_extents[0]);
 973         INIT_LIST_HEAD(&bl->bl_extents[1]);
 974         INIT_LIST_HEAD(&bl->bl_commit);
 975         INIT_LIST_HEAD(&bl->bl_committing);
 976         bl->bl_count = 0;
 977         bl->bl_blocksize = NFS_SERVER(inode)->pnfs_blksize >> SECTOR_SHIFT;
 978         BL_INIT_INVAL_MARKS(&bl->bl_inval, bl->bl_blocksize);
 979         return &bl->bl_layout;
 980 }
 981
 982 static void bl_free_lseg(struct pnfs_layout_segment *lseg)
 983 {
 984         dprintk("%s enter\n", __func__);
 985         kfree(lseg);
 986 }
 987
 988 /* We pretty much ignore lseg, and store all data layout wide, so we
 989  * can correctly merge.
 990  */
 991 static struct pnfs_layout_segment *bl_alloc_lseg(struct pnfs_layout_hdr *lo,
 992                                                  struct nfs4_layoutget_res *lgr,
 993                                                  gfp_t gfp_flags)
 994 {
 995         struct pnfs_layout_segment *lseg;
 996         int status;
 997
 998         dprintk("%s enter\n", __func__);
 999         lseg = kzalloc(sizeof(*lseg), gfp_flags);
1000         if (!lseg)
1001                 return ERR_PTR(-ENOMEM);
1002         status = nfs4_blk_process_layoutget(lo, lgr, gfp_flags);
1003         if (status) {
1004                 /* We don't want to call the full-blown bl_free_lseg,
1005                  * since on error extents were not touched.
1006                  */
1007                 kfree(lseg);
1008                 return ERR_PTR(status);
1009         }
1010         return lseg;
1011 }
1012
1013 static void
1014 bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr,
1015                        const struct nfs4_layoutcommit_args *arg)
1016 {
1017         dprintk("%s enter\n", __func__);
1018         encode_pnfs_block_layoutupdate(BLK_LO2EXT(lo), xdr, arg);
1019 }
1020
1021 static void
1022 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
1023 {
1024         struct pnfs_layout_hdr *lo = NFS_I(lcdata->args.inode)->layout;
1025
1026         dprintk("%s enter\n", __func__);
1027         clean_pnfs_block_layoutupdate(BLK_LO2EXT(lo), &lcdata->args, lcdata->res.status);
1028 }
1029
1030 static void free_blk_mountid(struct block_mount_id *mid)
1031 {
1032         if (mid) {
1033                 struct pnfs_block_dev *dev, *tmp;
1034
1035                 /* No need to take bm_lock as we are last user freeing bm_devlist */
1036                 list_for_each_entry_safe(dev, tmp, &mid->bm_devlist, bm_node) {
1037                         list_del(&dev->bm_node);
1038                         bl_free_block_dev(dev);
1039                 }
1040                 kfree(mid);
1041         }
1042 }
1043
1044 /* This is mostly copied from the filelayout_get_device_info function.
1045  * It seems much of this should be at the generic pnfs level.
1046  */
1047 static struct pnfs_block_dev *
1048 nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
1049                         struct nfs4_deviceid *d_id)
1050 {
1051         struct pnfs_device *dev;
1052         struct pnfs_block_dev *rv;
1053         u32 max_resp_sz;
1054         int max_pages;
1055         struct page **pages = NULL;
1056         int i, rc;
1057
1058         /*
1059          * Use the session max response size as the basis for setting
1060          * GETDEVICEINFO's maxcount
1061          */
1062         max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
1063         max_pages = nfs_page_array_len(0, max_resp_sz);
1064         dprintk("%s max_resp_sz %u max_pages %d\n",
1065                 __func__, max_resp_sz, max_pages);
1066
1067         dev = kmalloc(sizeof(*dev), GFP_NOFS);
1068         if (!dev) {
1069                 dprintk("%s kmalloc failed\n", __func__);
1070                 return ERR_PTR(-ENOMEM);
1071         }
1072
1073         pages = kzalloc(max_pages * sizeof(struct page *), GFP_NOFS);
1074         if (pages == NULL) {
1075                 kfree(dev);
1076                 return ERR_PTR(-ENOMEM);
1077         }
1078         for (i = 0; i < max_pages; i++) {
1079                 pages[i] = alloc_page(GFP_NOFS);
1080                 if (!pages[i]) {
1081                         rv = ERR_PTR(-ENOMEM);
1082                         goto out_free;
1083                 }
1084         }
1085
1086         memcpy(&dev->dev_id, d_id, sizeof(*d_id));
1087         dev->layout_type = LAYOUT_BLOCK_VOLUME;
1088         dev->pages = pages;
1089         dev->pgbase = 0;
1090         dev->pglen = PAGE_SIZE * max_pages;
1091         dev->mincount = 0;
1092
1093         dprintk("%s: dev_id: %s\n", __func__, dev->dev_id.data);
1094         rc = nfs4_proc_getdeviceinfo(server, dev);
1095         dprintk("%s getdevice info returns %d\n", __func__, rc);
1096         if (rc) {
1097                 rv = ERR_PTR(rc);
1098                 goto out_free;
1099         }
1100
1101         rv = nfs4_blk_decode_device(server, dev);
1102  out_free:
1103         for (i = 0; i < max_pages; i++)
1104                 __free_page(pages[i]);
1105         kfree(pages);
1106         kfree(dev);
1107         return rv;
1108 }
1109
1110 static int
1111 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
1112 {
1113         struct block_mount_id *b_mt_id = NULL;
1114         struct pnfs_devicelist *dlist = NULL;
1115         struct pnfs_block_dev *bdev;
1116         LIST_HEAD(block_disklist);
1117         int status, i;
1118
1119         dprintk("%s enter\n", __func__);
1120
1121         if (server->pnfs_blksize == 0) {
1122                 dprintk("%s Server did not return blksize\n", __func__);
1123                 return -EINVAL;
1124         }
1125         b_mt_id = kzalloc(sizeof(struct block_mount_id), GFP_NOFS);
1126         if (!b_mt_id) {
1127                 status = -ENOMEM;
1128                 goto out_error;
1129         }
1130         /* Initialize nfs4 block layout mount id */
1131         spin_lock_init(&b_mt_id->bm_lock);
1132         INIT_LIST_HEAD(&b_mt_id->bm_devlist);
1133
1134         dlist = kmalloc(sizeof(struct pnfs_devicelist), GFP_NOFS);
1135         if (!dlist) {
1136                 status = -ENOMEM;
1137                 goto out_error;
1138         }
1139         dlist->eof = 0;
1140         while (!dlist->eof) {
1141                 status = nfs4_proc_getdevicelist(server, fh, dlist);
1142                 if (status)
1143                         goto out_error;
1144                 dprintk("%s GETDEVICELIST numdevs=%i, eof=%i\n",
1145                         __func__, dlist->num_devs, dlist->eof);
1146                 for (i = 0; i < dlist->num_devs; i++) {
1147                         bdev = nfs4_blk_get_deviceinfo(server, fh,
1148                                                        &dlist->dev_id[i]);
1149                         if (IS_ERR(bdev)) {
1150                                 status = PTR_ERR(bdev);
1151                                 goto out_error;
1152                         }
1153                         spin_lock(&b_mt_id->bm_lock);
1154                         list_add(&bdev->bm_node, &b_mt_id->bm_devlist);
1155                         spin_unlock(&b_mt_id->bm_lock);
1156                 }
1157         }
1158         dprintk("%s SUCCESS\n", __func__);
1159         server->pnfs_ld_data = b_mt_id;
1160
1161  out_return:
1162         kfree(dlist);
1163         return status;
1164
1165  out_error:
1166         free_blk_mountid(b_mt_id);
1167         goto out_return;
1168 }
1169
1170 static int
1171 bl_clear_layoutdriver(struct nfs_server *server)
1172 {
1173         struct block_mount_id *b_mt_id = server->pnfs_ld_data;
1174
1175         dprintk("%s enter\n", __func__);
1176         free_blk_mountid(b_mt_id);
1177         dprintk("%s RETURNS\n", __func__);
1178         return 0;
1179 }
1180
1181 static bool
1182 is_aligned_req(struct nfs_page *req, unsigned int alignment)
1183 {
1184         return IS_ALIGNED(req->wb_offset, alignment) &&
1185                IS_ALIGNED(req->wb_bytes, alignment);
1186 }
1187
1188 static void
1189 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1190 {
1191         if (pgio->pg_dreq != NULL &&
1192             !is_aligned_req(req, SECTOR_SIZE))
1193                 nfs_pageio_reset_read_mds(pgio);
1194         else
1195                 pnfs_generic_pg_init_read(pgio, req);
1196 }
1197
1198 static bool
1199 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
1200                 struct nfs_page *req)
1201 {
1202         if (pgio->pg_dreq != NULL &&
1203             !is_aligned_req(req, SECTOR_SIZE))
1204                 return false;
1205
1206         return pnfs_generic_pg_test(pgio, prev, req);
1207 }
1208
1209 /*
1210  * Return the number of contiguous bytes for a given inode
1211  * starting at page frame idx.
1212  */
1213 static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
1214 {
1215         struct address_space *mapping = inode->i_mapping;
1216         pgoff_t end;
1217
1218         /* Optimize common case that writes from 0 to end of file */
1219         end = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
1220         if (end != NFS_I(inode)->npages) {
1221                 rcu_read_lock();
1222                 end = radix_tree_next_hole(&mapping->page_tree, idx + 1, ULONG_MAX);
1223                 rcu_read_unlock();
1224         }
1225
1226         if (!end)
1227                 return i_size_read(inode) - (idx << PAGE_CACHE_SHIFT);
1228         else
1229                 return (end - idx) << PAGE_CACHE_SHIFT;
1230 }
1231
1232 static void
1233 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1234 {
1235         if (pgio->pg_dreq != NULL &&
1236             !is_aligned_req(req, PAGE_CACHE_SIZE)) {
1237                 nfs_pageio_reset_write_mds(pgio);
1238         } else {
1239                 u64 wb_size;
1240                 if (pgio->pg_dreq == NULL)
1241                         wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
1242                                                       req->wb_index);
1243                 else
1244                         wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
1245
1246                 pnfs_generic_pg_init_write(pgio, req, wb_size);
1247         }
1248 }
1249
1250 static bool
1251 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
1252                  struct nfs_page *req)
1253 {
1254         if (pgio->pg_dreq != NULL &&
1255             !is_aligned_req(req, PAGE_CACHE_SIZE))
1256                 return false;
1257
1258         return pnfs_generic_pg_test(pgio, prev, req);
1259 }
1260
1261 static const struct nfs_pageio_ops bl_pg_read_ops = {
1262         .pg_init = bl_pg_init_read,
1263         .pg_test = bl_pg_test_read,
1264         .pg_doio = pnfs_generic_pg_readpages,
1265 };
1266
1267 static const struct nfs_pageio_ops bl_pg_write_ops = {
1268         .pg_init = bl_pg_init_write,
1269         .pg_test = bl_pg_test_write,
1270         .pg_doio = pnfs_generic_pg_writepages,
1271 };
1272
1273 static struct pnfs_layoutdriver_type blocklayout_type = {
1274         .id                             = LAYOUT_BLOCK_VOLUME,
1275         .name                           = "LAYOUT_BLOCK_VOLUME",
1276         .owner                          = THIS_MODULE,
1277         .read_pagelist                  = bl_read_pagelist,
1278         .write_pagelist                 = bl_write_pagelist,
1279         .alloc_layout_hdr               = bl_alloc_layout_hdr,
1280         .free_layout_hdr                = bl_free_layout_hdr,
1281         .alloc_lseg                     = bl_alloc_lseg,
1282         .free_lseg                      = bl_free_lseg,
1283         .encode_layoutcommit            = bl_encode_layoutcommit,
1284         .cleanup_layoutcommit           = bl_cleanup_layoutcommit,
1285         .set_layoutdriver               = bl_set_layoutdriver,
1286         .clear_layoutdriver             = bl_clear_layoutdriver,
1287         .pg_read_ops                    = &bl_pg_read_ops,
1288         .pg_write_ops                   = &bl_pg_write_ops,
1289 };
1290
1291 static const struct rpc_pipe_ops bl_upcall_ops = {
1292         .upcall         = rpc_pipe_generic_upcall,
1293         .downcall       = bl_pipe_downcall,
1294         .destroy_msg    = bl_pipe_destroy_msg,
1295 };
1296
1297 static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
1298                                             struct rpc_pipe *pipe)
1299 {
1300         struct dentry *dir, *dentry;
1301
1302         dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
1303         if (dir == NULL)
1304                 return ERR_PTR(-ENOENT);
1305         dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
1306         dput(dir);
1307         return dentry;
1308 }
1309
1310 static void nfs4blocklayout_unregister_sb(struct super_block *sb,
1311                                           struct rpc_pipe *pipe)
1312 {
1313         if (pipe->dentry)
1314                 rpc_unlink(pipe->dentry);
1315 }
1316
1317 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
1318                            void *ptr)
1319 {
1320         struct super_block *sb = ptr;
1321         struct net *net = sb->s_fs_info;
1322         struct nfs_net *nn = net_generic(net, nfs_net_id);
1323         struct dentry *dentry;
1324         int ret = 0;
1325
1326         if (!try_module_get(THIS_MODULE))
1327                 return 0;
1328
1329         if (nn->bl_device_pipe == NULL) {
1330                 module_put(THIS_MODULE);
1331                 return 0;
1332         }
1333
1334         switch (event) {
1335         case RPC_PIPEFS_MOUNT:
1336                 dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
1337                 if (IS_ERR(dentry)) {
1338                         ret = PTR_ERR(dentry);
1339                         break;
1340                 }
1341                 nn->bl_device_pipe->dentry = dentry;
1342                 break;
1343         case RPC_PIPEFS_UMOUNT:
1344                 if (nn->bl_device_pipe->dentry)
1345                         nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
1346                 break;
1347         default:
1348                 ret = -ENOTSUPP;
1349                 break;
1350         }
1351         module_put(THIS_MODULE);
1352         return ret;
1353 }
1354
1355 static struct notifier_block nfs4blocklayout_block = {
1356         .notifier_call = rpc_pipefs_event,
1357 };
1358
1359 static struct dentry *nfs4blocklayout_register_net(struct net *net,
1360                                                    struct rpc_pipe *pipe)
1361 {
1362         struct super_block *pipefs_sb;
1363         struct dentry *dentry;
1364
1365         pipefs_sb = rpc_get_sb_net(net);
1366         if (!pipefs_sb)
1367                 return NULL;
1368         dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
1369         rpc_put_sb_net(net);
1370         return dentry;
1371 }
1372
1373 static void nfs4blocklayout_unregister_net(struct net *net,
1374                                            struct rpc_pipe *pipe)
1375 {
1376         struct super_block *pipefs_sb;
1377
1378         pipefs_sb = rpc_get_sb_net(net);
1379         if (pipefs_sb) {
1380                 nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
1381                 rpc_put_sb_net(net);
1382         }
1383 }
1384
1385 static int nfs4blocklayout_net_init(struct net *net)
1386 {
1387         struct nfs_net *nn = net_generic(net, nfs_net_id);
1388         struct dentry *dentry;
1389
1390         init_waitqueue_head(&nn->bl_wq);
1391         nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
1392         if (IS_ERR(nn->bl_device_pipe))
1393                 return PTR_ERR(nn->bl_device_pipe);
1394         dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
1395         if (IS_ERR(dentry)) {
1396                 rpc_destroy_pipe_data(nn->bl_device_pipe);
1397                 return PTR_ERR(dentry);
1398         }
1399         nn->bl_device_pipe->dentry = dentry;
1400         return 0;
1401 }
1402
1403 static void nfs4blocklayout_net_exit(struct net *net)
1404 {
1405         struct nfs_net *nn = net_generic(net, nfs_net_id);
1406
1407         nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
1408         rpc_destroy_pipe_data(nn->bl_device_pipe);
1409         nn->bl_device_pipe = NULL;
1410 }
1411
1412 static struct pernet_operations nfs4blocklayout_net_ops = {
1413         .init = nfs4blocklayout_net_init,
1414         .exit = nfs4blocklayout_net_exit,
1415 };
1416
1417 static int __init nfs4blocklayout_init(void)
1418 {
1419         int ret;
1420
1421         dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
1422
1423         ret = pnfs_register_layoutdriver(&blocklayout_type);
1424         if (ret)
1425                 goto out;
1426
1427         ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
1428         if (ret)
1429                 goto out_remove;
1430         ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
1431         if (ret)
1432                 goto out_notifier;
1433 out:
1434         return ret;
1435
1436 out_notifier:
1437         rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
1438 out_remove:
1439         pnfs_unregister_layoutdriver(&blocklayout_type);
1440         return ret;
1441 }
1442
1443 static void __exit nfs4blocklayout_exit(void)
1444 {
1445         dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
1446                __func__);
1447
1448         rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
1449         unregister_pernet_subsys(&nfs4blocklayout_net_ops);
1450         pnfs_unregister_layoutdriver(&blocklayout_type);
1451 }
1452
1453 MODULE_ALIAS("nfs-layouttype4-3");
1454
1455 module_init(nfs4blocklayout_init);
1456 module_exit(nfs4blocklayout_exit);