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