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", bio->bi_iter.bi_size,
 138                         (unsigned long long)bio->bi_iter.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_iter.bi_sector = isect - be->be_f_offset +
 160                         be->be_v_offset;
 161                 bio->bi_bdev = be->be_mdev;
 162                 bio->bi_end_io = end_io;
 163                 bio->bi_private = par;
 164         }
 165         return bio;
 166 }
 167
 168 static struct bio *do_add_page_to_bio(struct bio *bio, int npg, int rw,
 169                                       sector_t isect, struct page *page,
 170                                       struct pnfs_block_extent *be,
 171                                       void (*end_io)(struct bio *, int err),
 172                                       struct parallel_io *par,
 173                                       unsigned int offset, int len)
 174 {
 175         isect = isect + (offset >> SECTOR_SHIFT);
 176         dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
 177                 npg, rw, (unsigned long long)isect, offset, len);
 178 retry:
 179         if (!bio) {
 180                 bio = bl_alloc_init_bio(npg, isect, be, end_io, par);
 181                 if (!bio)
 182                         return ERR_PTR(-ENOMEM);
 183         }
 184         if (bio_add_page(bio, page, len, offset) < len) {
 185                 bio = bl_submit_bio(rw, bio);
 186                 goto retry;
 187         }
 188         return bio;
 189 }
 190
 191 static struct bio *bl_add_page_to_bio(struct bio *bio, int npg, int rw,
 192                                       sector_t isect, struct page *page,
 193                                       struct pnfs_block_extent *be,
 194                                       void (*end_io)(struct bio *, int err),
 195                                       struct parallel_io *par)
 196 {
 197         return do_add_page_to_bio(bio, npg, rw, isect, page, be,
 198                                   end_io, par, 0, PAGE_CACHE_SIZE);
 199 }
 200
 201 /* This is basically copied from mpage_end_io_read */
 202 static void bl_end_io_read(struct bio *bio, int err)
 203 {
 204         struct parallel_io *par = bio->bi_private;
 205         struct bio_vec *bvec;
 206         int i;
 207
 208         if (!err)
 209                 bio_for_each_segment_all(bvec, bio, i)
 210                         SetPageUptodate(bvec->bv_page);
 211
 212         if (err) {
 213                 struct nfs_read_data *rdata = par->data;
 214                 struct nfs_pgio_header *header = rdata->header;
 215
 216                 if (!header->pnfs_error)
 217                         header->pnfs_error = -EIO;
 218                 pnfs_set_lo_fail(header->lseg);
 219         }
 220         bio_put(bio);
 221         put_parallel(par);
 222 }
 223
 224 static void bl_read_cleanup(struct work_struct *work)
 225 {
 226         struct rpc_task *task;
 227         struct nfs_read_data *rdata;
 228         dprintk("%s enter\n", __func__);
 229         task = container_of(work, struct rpc_task, u.tk_work);
 230         rdata = container_of(task, struct nfs_read_data, task);
 231         pnfs_ld_read_done(rdata);
 232 }
 233
 234 static void
 235 bl_end_par_io_read(void *data, int unused)
 236 {
 237         struct nfs_read_data *rdata = data;
 238
 239         rdata->task.tk_status = rdata->header->pnfs_error;
 240         INIT_WORK(&rdata->task.u.tk_work, bl_read_cleanup);
 241         schedule_work(&rdata->task.u.tk_work);
 242 }
 243
 244 static enum pnfs_try_status
 245 bl_read_pagelist(struct nfs_read_data *rdata)
 246 {
 247         struct nfs_pgio_header *header = rdata->header;
 248         int i, hole;
 249         struct bio *bio = NULL;
 250         struct pnfs_block_extent *be = NULL, *cow_read = NULL;
 251         sector_t isect, extent_length = 0;
 252         struct parallel_io *par;
 253         loff_t f_offset = rdata->args.offset;
 254         size_t bytes_left = rdata->args.count;
 255         unsigned int pg_offset, pg_len;
 256         struct page **pages = rdata->args.pages;
 257         int pg_index = rdata->args.pgbase >> PAGE_CACHE_SHIFT;
 258         const bool is_dio = (header->dreq != NULL);
 259
 260         dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
 261                rdata->pages.npages, f_offset, (unsigned int)rdata->args.count);
 262
 263         par = alloc_parallel(rdata);
 264         if (!par)
 265                 goto use_mds;
 266         par->pnfs_callback = bl_end_par_io_read;
 267         /* At this point, we can no longer jump to use_mds */
 268
 269         isect = (sector_t) (f_offset >> SECTOR_SHIFT);
 270         /* Code assumes extents are page-aligned */
 271         for (i = pg_index; i < rdata->pages.npages; i++) {
 272                 if (!extent_length) {
 273                         /* We've used up the previous extent */
 274                         bl_put_extent(be);
 275                         bl_put_extent(cow_read);
 276                         bio = bl_submit_bio(READ, bio);
 277                         /* Get the next one */
 278                         be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg),
 279                                              isect, &cow_read);
 280                         if (!be) {
 281                                 header->pnfs_error = -EIO;
 282                                 goto out;
 283                         }
 284                         extent_length = be->be_length -
 285                                 (isect - be->be_f_offset);
 286                         if (cow_read) {
 287                                 sector_t cow_length = cow_read->be_length -
 288                                         (isect - cow_read->be_f_offset);
 289                                 extent_length = min(extent_length, cow_length);
 290                         }
 291                 }
 292
 293                 if (is_dio) {
 294                         pg_offset = f_offset & ~PAGE_CACHE_MASK;
 295                         if (pg_offset + bytes_left > PAGE_CACHE_SIZE)
 296                                 pg_len = PAGE_CACHE_SIZE - pg_offset;
 297                         else
 298                                 pg_len = bytes_left;
 299
 300                         f_offset += pg_len;
 301                         bytes_left -= pg_len;
 302                         isect += (pg_offset >> SECTOR_SHIFT);
 303                 } else {
 304                         pg_offset = 0;
 305                         pg_len = PAGE_CACHE_SIZE;
 306                 }
 307
 308                 hole = is_hole(be, isect);
 309                 if (hole && !cow_read) {
 310                         bio = bl_submit_bio(READ, bio);
 311                         /* Fill hole w/ zeroes w/o accessing device */
 312                         dprintk("%s Zeroing page for hole\n", __func__);
 313                         zero_user_segment(pages[i], pg_offset, pg_len);
 314                         print_page(pages[i]);
 315                         SetPageUptodate(pages[i]);
 316                 } else {
 317                         struct pnfs_block_extent *be_read;
 318
 319                         be_read = (hole && cow_read) ? cow_read : be;
 320                         bio = do_add_page_to_bio(bio, rdata->pages.npages - i,
 321                                                  READ,
 322                                                  isect, pages[i], be_read,
 323                                                  bl_end_io_read, par,
 324                                                  pg_offset, pg_len);
 325                         if (IS_ERR(bio)) {
 326                                 header->pnfs_error = PTR_ERR(bio);
 327                                 bio = NULL;
 328                                 goto out;
 329                         }
 330                 }
 331                 isect += (pg_len >> SECTOR_SHIFT);
 332                 extent_length -= PAGE_CACHE_SECTORS;
 333         }
 334         if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
 335                 rdata->res.eof = 1;
 336                 rdata->res.count = header->inode->i_size - rdata->args.offset;
 337         } else {
 338                 rdata->res.count = (isect << SECTOR_SHIFT) - rdata->args.offset;
 339         }
 340 out:
 341         bl_put_extent(be);
 342         bl_put_extent(cow_read);
 343         bl_submit_bio(READ, bio);
 344         put_parallel(par);
 345         return PNFS_ATTEMPTED;
 346
 347  use_mds:
 348         dprintk("Giving up and using normal NFS\n");
 349         return PNFS_NOT_ATTEMPTED;
 350 }
 351
 352 static void mark_extents_written(struct pnfs_block_layout *bl,
 353                                  __u64 offset, __u32 count)
 354 {
 355         sector_t isect, end;
 356         struct pnfs_block_extent *be;
 357         struct pnfs_block_short_extent *se;
 358
 359         dprintk("%s(%llu, %u)\n", __func__, offset, count);
 360         if (count == 0)
 361                 return;
 362         isect = (offset & (long)(PAGE_CACHE_MASK)) >> SECTOR_SHIFT;
 363         end = (offset + count + PAGE_CACHE_SIZE - 1) & (long)(PAGE_CACHE_MASK);
 364         end >>= SECTOR_SHIFT;
 365         while (isect < end) {
 366                 sector_t len;
 367                 be = bl_find_get_extent(bl, isect, NULL);
 368                 BUG_ON(!be); /* FIXME */
 369                 len = min(end, be->be_f_offset + be->be_length) - isect;
 370                 if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 371                         se = bl_pop_one_short_extent(be->be_inval);
 372                         BUG_ON(!se);
 373                         bl_mark_for_commit(be, isect, len, se);
 374                 }
 375                 isect += len;
 376                 bl_put_extent(be);
 377         }
 378 }
 379
 380 static void bl_end_io_write_zero(struct bio *bio, int err)
 381 {
 382         struct parallel_io *par = bio->bi_private;
 383         struct bio_vec *bvec;
 384         int i;
 385
 386         bio_for_each_segment_all(bvec, bio, i) {
 387                 /* This is the zeroing page we added */
 388                 end_page_writeback(bvec->bv_page);
 389                 page_cache_release(bvec->bv_page);
 390         }
 391
 392         if (unlikely(err)) {
 393                 struct nfs_write_data *data = par->data;
 394                 struct nfs_pgio_header *header = data->header;
 395
 396                 if (!header->pnfs_error)
 397                         header->pnfs_error = -EIO;
 398                 pnfs_set_lo_fail(header->lseg);
 399         }
 400         bio_put(bio);
 401         put_parallel(par);
 402 }
 403
 404 static void bl_end_io_write(struct bio *bio, int err)
 405 {
 406         struct parallel_io *par = bio->bi_private;
 407         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 408         struct nfs_write_data *data = par->data;
 409         struct nfs_pgio_header *header = data->header;
 410
 411         if (!uptodate) {
 412                 if (!header->pnfs_error)
 413                         header->pnfs_error = -EIO;
 414                 pnfs_set_lo_fail(header->lseg);
 415         }
 416         bio_put(bio);
 417         put_parallel(par);
 418 }
 419
 420 /* Function scheduled for call during bl_end_par_io_write,
 421  * it marks sectors as written and extends the commitlist.
 422  */
 423 static void bl_write_cleanup(struct work_struct *work)
 424 {
 425         struct rpc_task *task;
 426         struct nfs_write_data *wdata;
 427         dprintk("%s enter\n", __func__);
 428         task = container_of(work, struct rpc_task, u.tk_work);
 429         wdata = container_of(task, struct nfs_write_data, task);
 430         if (likely(!wdata->header->pnfs_error)) {
 431                 /* Marks for LAYOUTCOMMIT */
 432                 mark_extents_written(BLK_LSEG2EXT(wdata->header->lseg),
 433                                      wdata->args.offset, wdata->args.count);
 434         }
 435         pnfs_ld_write_done(wdata);
 436 }
 437
 438 /* Called when last of bios associated with a bl_write_pagelist call finishes */
 439 static void bl_end_par_io_write(void *data, int num_se)
 440 {
 441         struct nfs_write_data *wdata = data;
 442
 443         if (unlikely(wdata->header->pnfs_error)) {
 444                 bl_free_short_extents(&BLK_LSEG2EXT(wdata->header->lseg)->bl_inval,
 445                                         num_se);
 446         }
 447
 448         wdata->task.tk_status = wdata->header->pnfs_error;
 449         wdata->verf.committed = NFS_FILE_SYNC;
 450         INIT_WORK(&wdata->task.u.tk_work, bl_write_cleanup);
 451         schedule_work(&wdata->task.u.tk_work);
 452 }
 453
 454 /* FIXME STUB - mark intersection of layout and page as bad, so is not
 455  * used again.
 456  */
 457 static void mark_bad_read(void)
 458 {
 459         return;
 460 }
 461
 462 /*
 463  * map_block:  map a requested I/0 block (isect) into an offset in the LVM
 464  * block_device
 465  */
 466 static void
 467 map_block(struct buffer_head *bh, sector_t isect, struct pnfs_block_extent *be)
 468 {
 469         dprintk("%s enter be=%p\n", __func__, be);
 470
 471         set_buffer_mapped(bh);
 472         bh->b_bdev = be->be_mdev;
 473         bh->b_blocknr = (isect - be->be_f_offset + be->be_v_offset) >>
 474             (be->be_mdev->bd_inode->i_blkbits - SECTOR_SHIFT);
 475
 476         dprintk("%s isect %llu, bh->b_blocknr %ld, using bsize %Zd\n",
 477                 __func__, (unsigned long long)isect, (long)bh->b_blocknr,
 478                 bh->b_size);
 479         return;
 480 }
 481
 482 static void
 483 bl_read_single_end_io(struct bio *bio, int error)
 484 {
 485         struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 486         struct page *page = bvec->bv_page;
 487
 488         /* Only one page in bvec */
 489         unlock_page(page);
 490 }
 491
 492 static int
 493 bl_do_readpage_sync(struct page *page, struct pnfs_block_extent *be,
 494                     unsigned int offset, unsigned int len)
 495 {
 496         struct bio *bio;
 497         struct page *shadow_page;
 498         sector_t isect;
 499         char *kaddr, *kshadow_addr;
 500         int ret = 0;
 501
 502         dprintk("%s: offset %u len %u\n", __func__, offset, len);
 503
 504         shadow_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
 505         if (shadow_page == NULL)
 506                 return -ENOMEM;
 507
 508         bio = bio_alloc(GFP_NOIO, 1);
 509         if (bio == NULL)
 510                 return -ENOMEM;
 511
 512         isect = (page->index << PAGE_CACHE_SECTOR_SHIFT) +
 513                 (offset / SECTOR_SIZE);
 514
 515         bio->bi_iter.bi_sector = isect - be->be_f_offset + be->be_v_offset;
 516         bio->bi_bdev = be->be_mdev;
 517         bio->bi_end_io = bl_read_single_end_io;
 518
 519         lock_page(shadow_page);
 520         if (bio_add_page(bio, shadow_page,
 521                          SECTOR_SIZE, round_down(offset, SECTOR_SIZE)) == 0) {
 522                 unlock_page(shadow_page);
 523                 bio_put(bio);
 524                 return -EIO;
 525         }
 526
 527         submit_bio(READ, bio);
 528         wait_on_page_locked(shadow_page);
 529         if (unlikely(!test_bit(BIO_UPTODATE, &bio->bi_flags))) {
 530                 ret = -EIO;
 531         } else {
 532                 kaddr = kmap_atomic(page);
 533                 kshadow_addr = kmap_atomic(shadow_page);
 534                 memcpy(kaddr + offset, kshadow_addr + offset, len);
 535                 kunmap_atomic(kshadow_addr);
 536                 kunmap_atomic(kaddr);
 537         }
 538         __free_page(shadow_page);
 539         bio_put(bio);
 540
 541         return ret;
 542 }
 543
 544 static int
 545 bl_read_partial_page_sync(struct page *page, struct pnfs_block_extent *be,
 546                           unsigned int dirty_offset, unsigned int dirty_len,
 547                           bool full_page)
 548 {
 549         int ret = 0;
 550         unsigned int start, end;
 551
 552         if (full_page) {
 553                 start = 0;
 554                 end = PAGE_CACHE_SIZE;
 555         } else {
 556                 start = round_down(dirty_offset, SECTOR_SIZE);
 557                 end = round_up(dirty_offset + dirty_len, SECTOR_SIZE);
 558         }
 559
 560         dprintk("%s: offset %u len %d\n", __func__, dirty_offset, dirty_len);
 561         if (!be) {
 562                 zero_user_segments(page, start, dirty_offset,
 563                                    dirty_offset + dirty_len, end);
 564                 if (start == 0 && end == PAGE_CACHE_SIZE &&
 565                     trylock_page(page)) {
 566                         SetPageUptodate(page);
 567                         unlock_page(page);
 568                 }
 569                 return ret;
 570         }
 571
 572         if (start != dirty_offset)
 573                 ret = bl_do_readpage_sync(page, be, start, dirty_offset - start);
 574
 575         if (!ret && (dirty_offset + dirty_len < end))
 576                 ret = bl_do_readpage_sync(page, be, dirty_offset + dirty_len,
 577                                           end - dirty_offset - dirty_len);
 578
 579         return ret;
 580 }
 581
 582 /* Given an unmapped page, zero it or read in page for COW, page is locked
 583  * by caller.
 584  */
 585 static int
 586 init_page_for_write(struct page *page, struct pnfs_block_extent *cow_read)
 587 {
 588         struct buffer_head *bh = NULL;
 589         int ret = 0;
 590         sector_t isect;
 591
 592         dprintk("%s enter, %p\n", __func__, page);
 593         BUG_ON(PageUptodate(page));
 594         if (!cow_read) {
 595                 zero_user_segment(page, 0, PAGE_SIZE);
 596                 SetPageUptodate(page);
 597                 goto cleanup;
 598         }
 599
 600         bh = alloc_page_buffers(page, PAGE_CACHE_SIZE, 0);
 601         if (!bh) {
 602                 ret = -ENOMEM;
 603                 goto cleanup;
 604         }
 605
 606         isect = (sector_t) page->index << PAGE_CACHE_SECTOR_SHIFT;
 607         map_block(bh, isect, cow_read);
 608         if (!bh_uptodate_or_lock(bh))
 609                 ret = bh_submit_read(bh);
 610         if (ret)
 611                 goto cleanup;
 612         SetPageUptodate(page);
 613
 614 cleanup:
 615         if (bh)
 616                 free_buffer_head(bh);
 617         if (ret) {
 618                 /* Need to mark layout with bad read...should now
 619                  * just use nfs4 for reads and writes.
 620                  */
 621                 mark_bad_read();
 622         }
 623         return ret;
 624 }
 625
 626 /* Find or create a zeroing page marked being writeback.
 627  * Return ERR_PTR on error, NULL to indicate skip this page and page itself
 628  * to indicate write out.
 629  */
 630 static struct page *
 631 bl_find_get_zeroing_page(struct inode *inode, pgoff_t index,
 632                         struct pnfs_block_extent *cow_read)
 633 {
 634         struct page *page;
 635         int locked = 0;
 636         page = find_get_page(inode->i_mapping, index);
 637         if (page)
 638                 goto check_page;
 639
 640         page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
 641         if (unlikely(!page)) {
 642                 dprintk("%s oom\n", __func__);
 643                 return ERR_PTR(-ENOMEM);
 644         }
 645         locked = 1;
 646
 647 check_page:
 648         /* PageDirty: Other will write this out
 649          * PageWriteback: Other is writing this out
 650          * PageUptodate: It was read before
 651          */
 652         if (PageDirty(page) || PageWriteback(page)) {
 653                 print_page(page);
 654                 if (locked)
 655                         unlock_page(page);
 656                 page_cache_release(page);
 657                 return NULL;
 658         }
 659
 660         if (!locked) {
 661                 lock_page(page);
 662                 locked = 1;
 663                 goto check_page;
 664         }
 665         if (!PageUptodate(page)) {
 666                 /* New page, readin or zero it */
 667                 init_page_for_write(page, cow_read);
 668         }
 669         set_page_writeback(page);
 670         unlock_page(page);
 671
 672         return page;
 673 }
 674
 675 static enum pnfs_try_status
 676 bl_write_pagelist(struct nfs_write_data *wdata, int sync)
 677 {
 678         struct nfs_pgio_header *header = wdata->header;
 679         int i, ret, npg_zero, pg_index, last = 0;
 680         struct bio *bio = NULL;
 681         struct pnfs_block_extent *be = NULL, *cow_read = NULL;
 682         sector_t isect, last_isect = 0, extent_length = 0;
 683         struct parallel_io *par = NULL;
 684         loff_t offset = wdata->args.offset;
 685         size_t count = wdata->args.count;
 686         unsigned int pg_offset, pg_len, saved_len;
 687         struct page **pages = wdata->args.pages;
 688         struct page *page;
 689         pgoff_t index;
 690         u64 temp;
 691         int npg_per_block =
 692             NFS_SERVER(header->inode)->pnfs_blksize >> PAGE_CACHE_SHIFT;
 693
 694         dprintk("%s enter, %Zu@%lld\n", __func__, count, offset);
 695
 696         if (header->dreq != NULL &&
 697             (!IS_ALIGNED(offset, NFS_SERVER(header->inode)->pnfs_blksize) ||
 698              !IS_ALIGNED(count, NFS_SERVER(header->inode)->pnfs_blksize))) {
 699                 dprintk("pnfsblock nonblock aligned DIO writes. Resend MDS\n");
 700                 goto out_mds;
 701         }
 702         /* At this point, wdata->pages is a (sequential) list of nfs_pages.
 703          * We want to write each, and if there is an error set pnfs_error
 704          * to have it redone using nfs.
 705          */
 706         par = alloc_parallel(wdata);
 707         if (!par)
 708                 goto out_mds;
 709         par->pnfs_callback = bl_end_par_io_write;
 710         /* At this point, have to be more careful with error handling */
 711
 712         isect = (sector_t) ((offset & (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
 713         be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg), isect, &cow_read);
 714         if (!be || !is_writable(be, isect)) {
 715                 dprintk("%s no matching extents!\n", __func__);
 716                 goto out_mds;
 717         }
 718
 719         /* First page inside INVALID extent */
 720         if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 721                 if (likely(!bl_push_one_short_extent(be->be_inval)))
 722                         par->bse_count++;
 723                 else
 724                         goto out_mds;
 725                 temp = offset >> PAGE_CACHE_SHIFT;
 726                 npg_zero = do_div(temp, npg_per_block);
 727                 isect = (sector_t) (((offset - npg_zero * PAGE_CACHE_SIZE) &
 728                                      (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
 729                 extent_length = be->be_length - (isect - be->be_f_offset);
 730
 731 fill_invalid_ext:
 732                 dprintk("%s need to zero %d pages\n", __func__, npg_zero);
 733                 for (;npg_zero > 0; npg_zero--) {
 734                         if (bl_is_sector_init(be->be_inval, isect)) {
 735                                 dprintk("isect %llu already init\n",
 736                                         (unsigned long long)isect);
 737                                 goto next_page;
 738                         }
 739                         /* page ref released in bl_end_io_write_zero */
 740                         index = isect >> PAGE_CACHE_SECTOR_SHIFT;
 741                         dprintk("%s zero %dth page: index %lu isect %llu\n",
 742                                 __func__, npg_zero, index,
 743                                 (unsigned long long)isect);
 744                         page = bl_find_get_zeroing_page(header->inode, index,
 745                                                         cow_read);
 746                         if (unlikely(IS_ERR(page))) {
 747                                 header->pnfs_error = PTR_ERR(page);
 748                                 goto out;
 749                         } else if (page == NULL)
 750                                 goto next_page;
 751
 752                         ret = bl_mark_sectors_init(be->be_inval, isect,
 753                                                        PAGE_CACHE_SECTORS);
 754                         if (unlikely(ret)) {
 755                                 dprintk("%s bl_mark_sectors_init fail %d\n",
 756                                         __func__, ret);
 757                                 end_page_writeback(page);
 758                                 page_cache_release(page);
 759                                 header->pnfs_error = ret;
 760                                 goto out;
 761                         }
 762                         if (likely(!bl_push_one_short_extent(be->be_inval)))
 763                                 par->bse_count++;
 764                         else {
 765                                 end_page_writeback(page);
 766                                 page_cache_release(page);
 767                                 header->pnfs_error = -ENOMEM;
 768                                 goto out;
 769                         }
 770                         /* FIXME: This should be done in bi_end_io */
 771                         mark_extents_written(BLK_LSEG2EXT(header->lseg),
 772                                              page->index << PAGE_CACHE_SHIFT,
 773                                              PAGE_CACHE_SIZE);
 774
 775                         bio = bl_add_page_to_bio(bio, npg_zero, WRITE,
 776                                                  isect, page, be,
 777                                                  bl_end_io_write_zero, par);
 778                         if (IS_ERR(bio)) {
 779                                 header->pnfs_error = PTR_ERR(bio);
 780                                 bio = NULL;
 781                                 goto out;
 782                         }
 783 next_page:
 784                         isect += PAGE_CACHE_SECTORS;
 785                         extent_length -= PAGE_CACHE_SECTORS;
 786                 }
 787                 if (last)
 788                         goto write_done;
 789         }
 790         bio = bl_submit_bio(WRITE, bio);
 791
 792         /* Middle pages */
 793         pg_index = wdata->args.pgbase >> PAGE_CACHE_SHIFT;
 794         for (i = pg_index; i < wdata->pages.npages; i++) {
 795                 if (!extent_length) {
 796                         /* We've used up the previous extent */
 797                         bl_put_extent(be);
 798                         bl_put_extent(cow_read);
 799                         bio = bl_submit_bio(WRITE, bio);
 800                         /* Get the next one */
 801                         be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg),
 802                                              isect, &cow_read);
 803                         if (!be || !is_writable(be, isect)) {
 804                                 header->pnfs_error = -EINVAL;
 805                                 goto out;
 806                         }
 807                         if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 808                                 if (likely(!bl_push_one_short_extent(
 809                                                                 be->be_inval)))
 810                                         par->bse_count++;
 811                                 else {
 812                                         header->pnfs_error = -ENOMEM;
 813                                         goto out;
 814                                 }
 815                         }
 816                         extent_length = be->be_length -
 817                             (isect - be->be_f_offset);
 818                 }
 819
 820                 dprintk("%s offset %lld count %Zu\n", __func__, offset, count);
 821                 pg_offset = offset & ~PAGE_CACHE_MASK;
 822                 if (pg_offset + count > PAGE_CACHE_SIZE)
 823                         pg_len = PAGE_CACHE_SIZE - pg_offset;
 824                 else
 825                         pg_len = count;
 826
 827                 saved_len = pg_len;
 828                 if (be->be_state == PNFS_BLOCK_INVALID_DATA &&
 829                     !bl_is_sector_init(be->be_inval, isect)) {
 830                         ret = bl_read_partial_page_sync(pages[i], cow_read,
 831                                                         pg_offset, pg_len, true);
 832                         if (ret) {
 833                                 dprintk("%s bl_read_partial_page_sync fail %d\n",
 834                                         __func__, ret);
 835                                 header->pnfs_error = ret;
 836                                 goto out;
 837                         }
 838
 839                         ret = bl_mark_sectors_init(be->be_inval, isect,
 840                                                        PAGE_CACHE_SECTORS);
 841                         if (unlikely(ret)) {
 842                                 dprintk("%s bl_mark_sectors_init fail %d\n",
 843                                         __func__, ret);
 844                                 header->pnfs_error = ret;
 845                                 goto out;
 846                         }
 847
 848                         /* Expand to full page write */
 849                         pg_offset = 0;
 850                         pg_len = PAGE_CACHE_SIZE;
 851                 } else if  ((pg_offset & (SECTOR_SIZE - 1)) ||
 852                             (pg_len & (SECTOR_SIZE - 1))){
 853                         /* ahh, nasty case. We have to do sync full sector
 854                          * read-modify-write cycles.
 855                          */
 856                         unsigned int saved_offset = pg_offset;
 857                         ret = bl_read_partial_page_sync(pages[i], be, pg_offset,
 858                                                         pg_len, false);
 859                         pg_offset = round_down(pg_offset, SECTOR_SIZE);
 860                         pg_len = round_up(saved_offset + pg_len, SECTOR_SIZE)
 861                                  - pg_offset;
 862                 }
 863
 864
 865                 bio = do_add_page_to_bio(bio, wdata->pages.npages - i, WRITE,
 866                                          isect, pages[i], be,
 867                                          bl_end_io_write, par,
 868                                          pg_offset, pg_len);
 869                 if (IS_ERR(bio)) {
 870                         header->pnfs_error = PTR_ERR(bio);
 871                         bio = NULL;
 872                         goto out;
 873                 }
 874                 offset += saved_len;
 875                 count -= saved_len;
 876                 isect += PAGE_CACHE_SECTORS;
 877                 last_isect = isect;
 878                 extent_length -= PAGE_CACHE_SECTORS;
 879         }
 880
 881         /* Last page inside INVALID extent */
 882         if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 883                 bio = bl_submit_bio(WRITE, bio);
 884                 temp = last_isect >> PAGE_CACHE_SECTOR_SHIFT;
 885                 npg_zero = npg_per_block - do_div(temp, npg_per_block);
 886                 if (npg_zero < npg_per_block) {
 887                         last = 1;
 888                         goto fill_invalid_ext;
 889                 }
 890         }
 891
 892 write_done:
 893         wdata->res.count = wdata->args.count;
 894 out:
 895         bl_put_extent(be);
 896         bl_put_extent(cow_read);
 897         bl_submit_bio(WRITE, bio);
 898         put_parallel(par);
 899         return PNFS_ATTEMPTED;
 900 out_mds:
 901         bl_put_extent(be);
 902         bl_put_extent(cow_read);
 903         kfree(par);
 904         return PNFS_NOT_ATTEMPTED;
 905 }
 906
 907 /* FIXME - range ignored */
 908 static void
 909 release_extents(struct pnfs_block_layout *bl, struct pnfs_layout_range *range)
 910 {
 911         int i;
 912         struct pnfs_block_extent *be;
 913
 914         spin_lock(&bl->bl_ext_lock);
 915         for (i = 0; i < EXTENT_LISTS; i++) {
 916                 while (!list_empty(&bl->bl_extents[i])) {
 917                         be = list_first_entry(&bl->bl_extents[i],
 918                                               struct pnfs_block_extent,
 919                                               be_node);
 920                         list_del(&be->be_node);
 921                         bl_put_extent(be);
 922                 }
 923         }
 924         spin_unlock(&bl->bl_ext_lock);
 925 }
 926
 927 static void
 928 release_inval_marks(struct pnfs_inval_markings *marks)
 929 {
 930         struct pnfs_inval_tracking *pos, *temp;
 931         struct pnfs_block_short_extent *se, *stemp;
 932
 933         list_for_each_entry_safe(pos, temp, &marks->im_tree.mtt_stub, it_link) {
 934                 list_del(&pos->it_link);
 935                 kfree(pos);
 936         }
 937
 938         list_for_each_entry_safe(se, stemp, &marks->im_extents, bse_node) {
 939                 list_del(&se->bse_node);
 940                 kfree(se);
 941         }
 942         return;
 943 }
 944
 945 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
 946 {
 947         struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
 948
 949         dprintk("%s enter\n", __func__);
 950         release_extents(bl, NULL);
 951         release_inval_marks(&bl->bl_inval);
 952         kfree(bl);
 953 }
 954
 955 static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
 956                                                    gfp_t gfp_flags)
 957 {
 958         struct pnfs_block_layout *bl;
 959
 960         dprintk("%s enter\n", __func__);
 961         bl = kzalloc(sizeof(*bl), gfp_flags);
 962         if (!bl)
 963                 return NULL;
 964         spin_lock_init(&bl->bl_ext_lock);
 965         INIT_LIST_HEAD(&bl->bl_extents[0]);
 966         INIT_LIST_HEAD(&bl->bl_extents[1]);
 967         INIT_LIST_HEAD(&bl->bl_commit);
 968         INIT_LIST_HEAD(&bl->bl_committing);
 969         bl->bl_count = 0;
 970         bl->bl_blocksize = NFS_SERVER(inode)->pnfs_blksize >> SECTOR_SHIFT;
 971         BL_INIT_INVAL_MARKS(&bl->bl_inval, bl->bl_blocksize);
 972         return &bl->bl_layout;
 973 }
 974
 975 static void bl_free_lseg(struct pnfs_layout_segment *lseg)
 976 {
 977         dprintk("%s enter\n", __func__);
 978         kfree(lseg);
 979 }
 980
 981 /* We pretty much ignore lseg, and store all data layout wide, so we
 982  * can correctly merge.
 983  */
 984 static struct pnfs_layout_segment *bl_alloc_lseg(struct pnfs_layout_hdr *lo,
 985                                                  struct nfs4_layoutget_res *lgr,
 986                                                  gfp_t gfp_flags)
 987 {
 988         struct pnfs_layout_segment *lseg;
 989         int status;
 990
 991         dprintk("%s enter\n", __func__);
 992         lseg = kzalloc(sizeof(*lseg), gfp_flags);
 993         if (!lseg)
 994                 return ERR_PTR(-ENOMEM);
 995         status = nfs4_blk_process_layoutget(lo, lgr, gfp_flags);
 996         if (status) {
 997                 /* We don't want to call the full-blown bl_free_lseg,
 998                  * since on error extents were not touched.
 999                  */
1000                 kfree(lseg);
1001                 return ERR_PTR(status);
1002         }
1003         return lseg;
1004 }
1005
1006 static void
1007 bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr,
1008                        const struct nfs4_layoutcommit_args *arg)
1009 {
1010         dprintk("%s enter\n", __func__);
1011         encode_pnfs_block_layoutupdate(BLK_LO2EXT(lo), xdr, arg);
1012 }
1013
1014 static void
1015 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
1016 {
1017         struct pnfs_layout_hdr *lo = NFS_I(lcdata->args.inode)->layout;
1018
1019         dprintk("%s enter\n", __func__);
1020         clean_pnfs_block_layoutupdate(BLK_LO2EXT(lo), &lcdata->args, lcdata->res.status);
1021 }
1022
1023 static void free_blk_mountid(struct block_mount_id *mid)
1024 {
1025         if (mid) {
1026                 struct pnfs_block_dev *dev, *tmp;
1027
1028                 /* No need to take bm_lock as we are last user freeing bm_devlist */
1029                 list_for_each_entry_safe(dev, tmp, &mid->bm_devlist, bm_node) {
1030                         list_del(&dev->bm_node);
1031                         bl_free_block_dev(dev);
1032                 }
1033                 kfree(mid);
1034         }
1035 }
1036
1037 /* This is mostly copied from the filelayout_get_device_info function.
1038  * It seems much of this should be at the generic pnfs level.
1039  */
1040 static struct pnfs_block_dev *
1041 nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
1042                         struct nfs4_deviceid *d_id)
1043 {
1044         struct pnfs_device *dev;
1045         struct pnfs_block_dev *rv;
1046         u32 max_resp_sz;
1047         int max_pages;
1048         struct page **pages = NULL;
1049         int i, rc;
1050
1051         /*
1052          * Use the session max response size as the basis for setting
1053          * GETDEVICEINFO's maxcount
1054          */
1055         max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
1056         max_pages = nfs_page_array_len(0, max_resp_sz);
1057         dprintk("%s max_resp_sz %u max_pages %d\n",
1058                 __func__, max_resp_sz, max_pages);
1059
1060         dev = kmalloc(sizeof(*dev), GFP_NOFS);
1061         if (!dev) {
1062                 dprintk("%s kmalloc failed\n", __func__);
1063                 return ERR_PTR(-ENOMEM);
1064         }
1065
1066         pages = kzalloc(max_pages * sizeof(struct page *), GFP_NOFS);
1067         if (pages == NULL) {
1068                 kfree(dev);
1069                 return ERR_PTR(-ENOMEM);
1070         }
1071         for (i = 0; i < max_pages; i++) {
1072                 pages[i] = alloc_page(GFP_NOFS);
1073                 if (!pages[i]) {
1074                         rv = ERR_PTR(-ENOMEM);
1075                         goto out_free;
1076                 }
1077         }
1078
1079         memcpy(&dev->dev_id, d_id, sizeof(*d_id));
1080         dev->layout_type = LAYOUT_BLOCK_VOLUME;
1081         dev->pages = pages;
1082         dev->pgbase = 0;
1083         dev->pglen = PAGE_SIZE * max_pages;
1084         dev->mincount = 0;
1085         dev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
1086
1087         dprintk("%s: dev_id: %s\n", __func__, dev->dev_id.data);
1088         rc = nfs4_proc_getdeviceinfo(server, dev, NULL);
1089         dprintk("%s getdevice info returns %d\n", __func__, rc);
1090         if (rc) {
1091                 rv = ERR_PTR(rc);
1092                 goto out_free;
1093         }
1094
1095         rv = nfs4_blk_decode_device(server, dev);
1096  out_free:
1097         for (i = 0; i < max_pages; i++)
1098                 __free_page(pages[i]);
1099         kfree(pages);
1100         kfree(dev);
1101         return rv;
1102 }
1103
1104 static int
1105 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
1106 {
1107         struct block_mount_id *b_mt_id = NULL;
1108         struct pnfs_devicelist *dlist = NULL;
1109         struct pnfs_block_dev *bdev;
1110         LIST_HEAD(block_disklist);
1111         int status, i;
1112
1113         dprintk("%s enter\n", __func__);
1114
1115         if (server->pnfs_blksize == 0) {
1116                 dprintk("%s Server did not return blksize\n", __func__);
1117                 return -EINVAL;
1118         }
1119         b_mt_id = kzalloc(sizeof(struct block_mount_id), GFP_NOFS);
1120         if (!b_mt_id) {
1121                 status = -ENOMEM;
1122                 goto out_error;
1123         }
1124         /* Initialize nfs4 block layout mount id */
1125         spin_lock_init(&b_mt_id->bm_lock);
1126         INIT_LIST_HEAD(&b_mt_id->bm_devlist);
1127
1128         dlist = kmalloc(sizeof(struct pnfs_devicelist), GFP_NOFS);
1129         if (!dlist) {
1130                 status = -ENOMEM;
1131                 goto out_error;
1132         }
1133         dlist->eof = 0;
1134         while (!dlist->eof) {
1135                 status = nfs4_proc_getdevicelist(server, fh, dlist);
1136                 if (status)
1137                         goto out_error;
1138                 dprintk("%s GETDEVICELIST numdevs=%i, eof=%i\n",
1139                         __func__, dlist->num_devs, dlist->eof);
1140                 for (i = 0; i < dlist->num_devs; i++) {
1141                         bdev = nfs4_blk_get_deviceinfo(server, fh,
1142                                                        &dlist->dev_id[i]);
1143                         if (IS_ERR(bdev)) {
1144                                 status = PTR_ERR(bdev);
1145                                 goto out_error;
1146                         }
1147                         spin_lock(&b_mt_id->bm_lock);
1148                         list_add(&bdev->bm_node, &b_mt_id->bm_devlist);
1149                         spin_unlock(&b_mt_id->bm_lock);
1150                 }
1151         }
1152         dprintk("%s SUCCESS\n", __func__);
1153         server->pnfs_ld_data = b_mt_id;
1154
1155  out_return:
1156         kfree(dlist);
1157         return status;
1158
1159  out_error:
1160         free_blk_mountid(b_mt_id);
1161         goto out_return;
1162 }
1163
1164 static int
1165 bl_clear_layoutdriver(struct nfs_server *server)
1166 {
1167         struct block_mount_id *b_mt_id = server->pnfs_ld_data;
1168
1169         dprintk("%s enter\n", __func__);
1170         free_blk_mountid(b_mt_id);
1171         dprintk("%s RETURNS\n", __func__);
1172         return 0;
1173 }
1174
1175 static bool
1176 is_aligned_req(struct nfs_page *req, unsigned int alignment)
1177 {
1178         return IS_ALIGNED(req->wb_offset, alignment) &&
1179                IS_ALIGNED(req->wb_bytes, alignment);
1180 }
1181
1182 static void
1183 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1184 {
1185         if (pgio->pg_dreq != NULL &&
1186             !is_aligned_req(req, SECTOR_SIZE))
1187                 nfs_pageio_reset_read_mds(pgio);
1188         else
1189                 pnfs_generic_pg_init_read(pgio, req);
1190 }
1191
1192 static bool
1193 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
1194                 struct nfs_page *req)
1195 {
1196         if (pgio->pg_dreq != NULL &&
1197             !is_aligned_req(req, SECTOR_SIZE))
1198                 return false;
1199
1200         return pnfs_generic_pg_test(pgio, prev, req);
1201 }
1202
1203 /*
1204  * Return the number of contiguous bytes for a given inode
1205  * starting at page frame idx.
1206  */
1207 static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
1208 {
1209         struct address_space *mapping = inode->i_mapping;
1210         pgoff_t end;
1211
1212         /* Optimize common case that writes from 0 to end of file */
1213         end = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
1214         if (end != NFS_I(inode)->npages) {
1215                 rcu_read_lock();
1216                 end = radix_tree_next_hole(&mapping->page_tree, idx + 1, ULONG_MAX);
1217                 rcu_read_unlock();
1218         }
1219
1220         if (!end)
1221                 return i_size_read(inode) - (idx << PAGE_CACHE_SHIFT);
1222         else
1223                 return (end - idx) << PAGE_CACHE_SHIFT;
1224 }
1225
1226 static void
1227 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1228 {
1229         if (pgio->pg_dreq != NULL &&
1230             !is_aligned_req(req, PAGE_CACHE_SIZE)) {
1231                 nfs_pageio_reset_write_mds(pgio);
1232         } else {
1233                 u64 wb_size;
1234                 if (pgio->pg_dreq == NULL)
1235                         wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
1236                                                       req->wb_index);
1237                 else
1238                         wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
1239
1240                 pnfs_generic_pg_init_write(pgio, req, wb_size);
1241         }
1242 }
1243
1244 static bool
1245 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
1246                  struct nfs_page *req)
1247 {
1248         if (pgio->pg_dreq != NULL &&
1249             !is_aligned_req(req, PAGE_CACHE_SIZE))
1250                 return false;
1251
1252         return pnfs_generic_pg_test(pgio, prev, req);
1253 }
1254
1255 static const struct nfs_pageio_ops bl_pg_read_ops = {
1256         .pg_init = bl_pg_init_read,
1257         .pg_test = bl_pg_test_read,
1258         .pg_doio = pnfs_generic_pg_readpages,
1259 };
1260
1261 static const struct nfs_pageio_ops bl_pg_write_ops = {
1262         .pg_init = bl_pg_init_write,
1263         .pg_test = bl_pg_test_write,
1264         .pg_doio = pnfs_generic_pg_writepages,
1265 };
1266
1267 static struct pnfs_layoutdriver_type blocklayout_type = {
1268         .id                             = LAYOUT_BLOCK_VOLUME,
1269         .name                           = "LAYOUT_BLOCK_VOLUME",
1270         .owner                          = THIS_MODULE,
1271         .read_pagelist                  = bl_read_pagelist,
1272         .write_pagelist                 = bl_write_pagelist,
1273         .alloc_layout_hdr               = bl_alloc_layout_hdr,
1274         .free_layout_hdr                = bl_free_layout_hdr,
1275         .alloc_lseg                     = bl_alloc_lseg,
1276         .free_lseg                      = bl_free_lseg,
1277         .encode_layoutcommit            = bl_encode_layoutcommit,
1278         .cleanup_layoutcommit           = bl_cleanup_layoutcommit,
1279         .set_layoutdriver               = bl_set_layoutdriver,
1280         .clear_layoutdriver             = bl_clear_layoutdriver,
1281         .pg_read_ops                    = &bl_pg_read_ops,
1282         .pg_write_ops                   = &bl_pg_write_ops,
1283 };
1284
1285 static const struct rpc_pipe_ops bl_upcall_ops = {
1286         .upcall         = rpc_pipe_generic_upcall,
1287         .downcall       = bl_pipe_downcall,
1288         .destroy_msg    = bl_pipe_destroy_msg,
1289 };
1290
1291 static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
1292                                             struct rpc_pipe *pipe)
1293 {
1294         struct dentry *dir, *dentry;
1295
1296         dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
1297         if (dir == NULL)
1298                 return ERR_PTR(-ENOENT);
1299         dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
1300         dput(dir);
1301         return dentry;
1302 }
1303
1304 static void nfs4blocklayout_unregister_sb(struct super_block *sb,
1305                                           struct rpc_pipe *pipe)
1306 {
1307         if (pipe->dentry)
1308                 rpc_unlink(pipe->dentry);
1309 }
1310
1311 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
1312                            void *ptr)
1313 {
1314         struct super_block *sb = ptr;
1315         struct net *net = sb->s_fs_info;
1316         struct nfs_net *nn = net_generic(net, nfs_net_id);
1317         struct dentry *dentry;
1318         int ret = 0;
1319
1320         if (!try_module_get(THIS_MODULE))
1321                 return 0;
1322
1323         if (nn->bl_device_pipe == NULL) {
1324                 module_put(THIS_MODULE);
1325                 return 0;
1326         }
1327
1328         switch (event) {
1329         case RPC_PIPEFS_MOUNT:
1330                 dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
1331                 if (IS_ERR(dentry)) {
1332                         ret = PTR_ERR(dentry);
1333                         break;
1334                 }
1335                 nn->bl_device_pipe->dentry = dentry;
1336                 break;
1337         case RPC_PIPEFS_UMOUNT:
1338                 if (nn->bl_device_pipe->dentry)
1339                         nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
1340                 break;
1341         default:
1342                 ret = -ENOTSUPP;
1343                 break;
1344         }
1345         module_put(THIS_MODULE);
1346         return ret;
1347 }
1348
1349 static struct notifier_block nfs4blocklayout_block = {
1350         .notifier_call = rpc_pipefs_event,
1351 };
1352
1353 static struct dentry *nfs4blocklayout_register_net(struct net *net,
1354                                                    struct rpc_pipe *pipe)
1355 {
1356         struct super_block *pipefs_sb;
1357         struct dentry *dentry;
1358
1359         pipefs_sb = rpc_get_sb_net(net);
1360         if (!pipefs_sb)
1361                 return NULL;
1362         dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
1363         rpc_put_sb_net(net);
1364         return dentry;
1365 }
1366
1367 static void nfs4blocklayout_unregister_net(struct net *net,
1368                                            struct rpc_pipe *pipe)
1369 {
1370         struct super_block *pipefs_sb;
1371
1372         pipefs_sb = rpc_get_sb_net(net);
1373         if (pipefs_sb) {
1374                 nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
1375                 rpc_put_sb_net(net);
1376         }
1377 }
1378
1379 static int nfs4blocklayout_net_init(struct net *net)
1380 {
1381         struct nfs_net *nn = net_generic(net, nfs_net_id);
1382         struct dentry *dentry;
1383
1384         init_waitqueue_head(&nn->bl_wq);
1385         nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
1386         if (IS_ERR(nn->bl_device_pipe))
1387                 return PTR_ERR(nn->bl_device_pipe);
1388         dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
1389         if (IS_ERR(dentry)) {
1390                 rpc_destroy_pipe_data(nn->bl_device_pipe);
1391                 return PTR_ERR(dentry);
1392         }
1393         nn->bl_device_pipe->dentry = dentry;
1394         return 0;
1395 }
1396
1397 static void nfs4blocklayout_net_exit(struct net *net)
1398 {
1399         struct nfs_net *nn = net_generic(net, nfs_net_id);
1400
1401         nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
1402         rpc_destroy_pipe_data(nn->bl_device_pipe);
1403         nn->bl_device_pipe = NULL;
1404 }
1405
1406 static struct pernet_operations nfs4blocklayout_net_ops = {
1407         .init = nfs4blocklayout_net_init,
1408         .exit = nfs4blocklayout_net_exit,
1409 };
1410
1411 static int __init nfs4blocklayout_init(void)
1412 {
1413         int ret;
1414
1415         dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
1416
1417         ret = pnfs_register_layoutdriver(&blocklayout_type);
1418         if (ret)
1419                 goto out;
1420
1421         ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
1422         if (ret)
1423                 goto out_remove;
1424         ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
1425         if (ret)
1426                 goto out_notifier;
1427 out:
1428         return ret;
1429
1430 out_notifier:
1431         rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
1432 out_remove:
1433         pnfs_unregister_layoutdriver(&blocklayout_type);
1434         return ret;
1435 }
1436
1437 static void __exit nfs4blocklayout_exit(void)
1438 {
1439         dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
1440                __func__);
1441
1442         rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
1443         unregister_pernet_subsys(&nfs4blocklayout_net_ops);
1444         pnfs_unregister_layoutdriver(&blocklayout_type);
1445 }
1446
1447 MODULE_ALIAS("nfs-layouttype4-3");
1448
1449 module_init(nfs4blocklayout_init);
1450 module_exit(nfs4blocklayout_exit);