fs/exofs/inode.c

   1 /*
   2  * Copyright (C) 2005, 2006
   3  * Avishay Traeger (avishay@gmail.com)
   4  * Copyright (C) 2008, 2009
   5  * Boaz Harrosh <bharrosh@panasas.com>
   6  *
   7  * Copyrights for code taken from ext2:
   8  *     Copyright (C) 1992, 1993, 1994, 1995
   9  *     Remy Card (card@masi.ibp.fr)
  10  *     Laboratoire MASI - Institut Blaise Pascal
  11  *     Universite Pierre et Marie Curie (Paris VI)
  12  *     from
  13  *     linux/fs/minix/inode.c
  14  *     Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  * This file is part of exofs.
  17  *
  18  * exofs is free software; you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation.  Since it is based on ext2, and the only
  21  * valid version of GPL for the Linux kernel is version 2, the only valid
  22  * version of GPL for exofs is version 2.
  23  *
  24  * exofs is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with exofs; if not, write to the Free Software
  31  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  32  */
  33
  34 #include <linux/slab.h>
  35
  36 #include "exofs.h"
  37
  38 #define EXOFS_DBGMSG2(M...) do {} while (0)
  39
  40 enum { BIO_MAX_PAGES_KMALLOC =
  41                 (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),
  42         MAX_PAGES_KMALLOC =
  43                 PAGE_SIZE / sizeof(struct page *),
  44 };
  45
  46 unsigned exofs_max_io_pages(struct exofs_layout *layout,
  47                             unsigned expected_pages)
  48 {
  49         unsigned pages = min_t(unsigned, expected_pages, MAX_PAGES_KMALLOC);
  50
  51         /* TODO: easily support bio chaining */
  52         pages =  min_t(unsigned, pages,
  53                        layout->group_width * BIO_MAX_PAGES_KMALLOC);
  54         return pages;
  55 }
  56
  57 struct page_collect {
  58         struct exofs_sb_info *sbi;
  59         struct inode *inode;
  60         unsigned expected_pages;
  61         struct exofs_io_state *ios;
  62
  63         struct page **pages;
  64         unsigned alloc_pages;
  65         unsigned nr_pages;
  66         unsigned long length;
  67         loff_t pg_first; /* keep 64bit also in 32-arches */
  68         bool read_4_write; /* This means two things: that the read is sync
  69                             * And the pages should not be unlocked.
  70                             */
  71 };
  72
  73 static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
  74                        struct inode *inode)
  75 {
  76         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
  77
  78         pcol->sbi = sbi;
  79         pcol->inode = inode;
  80         pcol->expected_pages = expected_pages;
  81
  82         pcol->ios = NULL;
  83         pcol->pages = NULL;
  84         pcol->alloc_pages = 0;
  85         pcol->nr_pages = 0;
  86         pcol->length = 0;
  87         pcol->pg_first = -1;
  88         pcol->read_4_write = false;
  89 }
  90
  91 static void _pcol_reset(struct page_collect *pcol)
  92 {
  93         pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
  94
  95         pcol->pages = NULL;
  96         pcol->alloc_pages = 0;
  97         pcol->nr_pages = 0;
  98         pcol->length = 0;
  99         pcol->pg_first = -1;
 100         pcol->ios = NULL;
 101
 102         /* this is probably the end of the loop but in writes
 103          * it might not end here. don't be left with nothing
 104          */
 105         if (!pcol->expected_pages)
 106                 pcol->expected_pages = MAX_PAGES_KMALLOC;
 107 }
 108
 109 static int pcol_try_alloc(struct page_collect *pcol)
 110 {
 111         unsigned pages;
 112
 113         /* TODO: easily support bio chaining */
 114         pages =  exofs_max_io_pages(&pcol->sbi->layout, pcol->expected_pages);
 115
 116         for (; pages; pages >>= 1) {
 117                 pcol->pages = kmalloc(pages * sizeof(struct page *),
 118                                       GFP_KERNEL);
 119                 if (likely(pcol->pages)) {
 120                         pcol->alloc_pages = pages;
 121                         return 0;
 122                 }
 123         }
 124
 125         EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
 126                   pcol->expected_pages);
 127         return -ENOMEM;
 128 }
 129
 130 static void pcol_free(struct page_collect *pcol)
 131 {
 132         kfree(pcol->pages);
 133         pcol->pages = NULL;
 134
 135         if (pcol->ios) {
 136                 exofs_put_io_state(pcol->ios);
 137                 pcol->ios = NULL;
 138         }
 139 }
 140
 141 static int pcol_add_page(struct page_collect *pcol, struct page *page,
 142                          unsigned len)
 143 {
 144         if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
 145                 return -ENOMEM;
 146
 147         pcol->pages[pcol->nr_pages++] = page;
 148         pcol->length += len;
 149         return 0;
 150 }
 151
 152 static int update_read_page(struct page *page, int ret)
 153 {
 154         if (ret == 0) {
 155                 /* Everything is OK */
 156                 SetPageUptodate(page);
 157                 if (PageError(page))
 158                         ClearPageError(page);
 159         } else if (ret == -EFAULT) {
 160                 /* In this case we were trying to read something that wasn't on
 161                  * disk yet - return a page full of zeroes.  This should be OK,
 162                  * because the object should be empty (if there was a write
 163                  * before this read, the read would be waiting with the page
 164                  * locked */
 165                 clear_highpage(page);
 166
 167                 SetPageUptodate(page);
 168                 if (PageError(page))
 169                         ClearPageError(page);
 170                 ret = 0; /* recovered error */
 171                 EXOFS_DBGMSG("recovered read error\n");
 172         } else /* Error */
 173                 SetPageError(page);
 174
 175         return ret;
 176 }
 177
 178 static void update_write_page(struct page *page, int ret)
 179 {
 180         if (ret) {
 181                 mapping_set_error(page->mapping, ret);
 182                 SetPageError(page);
 183         }
 184         end_page_writeback(page);
 185 }
 186
 187 /* Called at the end of reads, to optionally unlock pages and update their
 188  * status.
 189  */
 190 static int __readpages_done(struct page_collect *pcol)
 191 {
 192         int i;
 193         u64 resid;
 194         u64 good_bytes;
 195         u64 length = 0;
 196         int ret = exofs_check_io(pcol->ios, &resid);
 197
 198         if (likely(!ret))
 199                 good_bytes = pcol->length;
 200         else
 201                 good_bytes = pcol->length - resid;
 202
 203         EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
 204                      " length=0x%lx nr_pages=%u\n",
 205                      pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
 206                      pcol->nr_pages);
 207
 208         for (i = 0; i < pcol->nr_pages; i++) {
 209                 struct page *page = pcol->pages[i];
 210                 struct inode *inode = page->mapping->host;
 211                 int page_stat;
 212
 213                 if (inode != pcol->inode)
 214                         continue; /* osd might add more pages at end */
 215
 216                 if (likely(length < good_bytes))
 217                         page_stat = 0;
 218                 else
 219                         page_stat = ret;
 220
 221                 EXOFS_DBGMSG2("    readpages_done(0x%lx, 0x%lx) %s\n",
 222                           inode->i_ino, page->index,
 223                           page_stat ? "bad_bytes" : "good_bytes");
 224
 225                 ret = update_read_page(page, page_stat);
 226                 if (!pcol->read_4_write)
 227                         unlock_page(page);
 228                 length += PAGE_SIZE;
 229         }
 230
 231         pcol_free(pcol);
 232         EXOFS_DBGMSG2("readpages_done END\n");
 233         return ret;
 234 }
 235
 236 /* callback of async reads */
 237 static void readpages_done(struct exofs_io_state *ios, void *p)
 238 {
 239         struct page_collect *pcol = p;
 240
 241         __readpages_done(pcol);
 242         atomic_dec(&pcol->sbi->s_curr_pending);
 243         kfree(pcol);
 244 }
 245
 246 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
 247 {
 248         int i;
 249
 250         for (i = 0; i < pcol->nr_pages; i++) {
 251                 struct page *page = pcol->pages[i];
 252
 253                 if (rw == READ)
 254                         update_read_page(page, ret);
 255                 else
 256                         update_write_page(page, ret);
 257
 258                 unlock_page(page);
 259         }
 260 }
 261
 262 static int read_exec(struct page_collect *pcol)
 263 {
 264         struct exofs_i_info *oi = exofs_i(pcol->inode);
 265         struct exofs_io_state *ios;
 266         struct page_collect *pcol_copy = NULL;
 267         int ret;
 268
 269         if (!pcol->pages)
 270                 return 0;
 271
 272         if (!pcol->ios) {
 273                 int ret = exofs_get_rw_state(&pcol->sbi->layout, true,
 274                                              pcol->pg_first << PAGE_CACHE_SHIFT,
 275                                              pcol->length, &pcol->ios);
 276
 277                 if (ret)
 278                         return ret;
 279         }
 280
 281         ios = pcol->ios;
 282         ios->pages = pcol->pages;
 283         ios->nr_pages = pcol->nr_pages;
 284
 285         if (pcol->read_4_write) {
 286                 exofs_oi_read(oi, pcol->ios);
 287                 return __readpages_done(pcol);
 288         }
 289
 290         pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
 291         if (!pcol_copy) {
 292                 ret = -ENOMEM;
 293                 goto err;
 294         }
 295
 296         *pcol_copy = *pcol;
 297         ios->done = readpages_done;
 298         ios->private = pcol_copy;
 299         ret = exofs_oi_read(oi, ios);
 300         if (unlikely(ret))
 301                 goto err;
 302
 303         atomic_inc(&pcol->sbi->s_curr_pending);
 304
 305         EXOFS_DBGMSG2("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
 306                   ios->obj.id, _LLU(ios->offset), pcol->length);
 307
 308         /* pages ownership was passed to pcol_copy */
 309         _pcol_reset(pcol);
 310         return 0;
 311
 312 err:
 313         if (!pcol->read_4_write)
 314                 _unlock_pcol_pages(pcol, ret, READ);
 315
 316         pcol_free(pcol);
 317
 318         kfree(pcol_copy);
 319         return ret;
 320 }
 321
 322 /* readpage_strip is called either directly from readpage() or by the VFS from
 323  * within read_cache_pages(), to add one more page to be read. It will try to
 324  * collect as many contiguous pages as posible. If a discontinuity is
 325  * encountered, or it runs out of resources, it will submit the previous segment
 326  * and will start a new collection. Eventually caller must submit the last
 327  * segment if present.
 328  */
 329 static int readpage_strip(void *data, struct page *page)
 330 {
 331         struct page_collect *pcol = data;
 332         struct inode *inode = pcol->inode;
 333         struct exofs_i_info *oi = exofs_i(inode);
 334         loff_t i_size = i_size_read(inode);
 335         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 336         size_t len;
 337         int ret;
 338
 339         /* FIXME: Just for debugging, will be removed */
 340         if (PageUptodate(page))
 341                 EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
 342                           page->index);
 343
 344         if (page->index < end_index)
 345                 len = PAGE_CACHE_SIZE;
 346         else if (page->index == end_index)
 347                 len = i_size & ~PAGE_CACHE_MASK;
 348         else
 349                 len = 0;
 350
 351         if (!len || !obj_created(oi)) {
 352                 /* this will be out of bounds, or doesn't exist yet.
 353                  * Current page is cleared and the request is split
 354                  */
 355                 clear_highpage(page);
 356
 357                 SetPageUptodate(page);
 358                 if (PageError(page))
 359                         ClearPageError(page);
 360
 361                 if (!pcol->read_4_write)
 362                         unlock_page(page);
 363                 EXOFS_DBGMSG("readpage_strip(0x%lx) empty page len=%zx "
 364                              "read_4_write=%d index=0x%lx end_index=0x%lx "
 365                              "splitting\n", inode->i_ino, len,
 366                              pcol->read_4_write, page->index, end_index);
 367
 368                 return read_exec(pcol);
 369         }
 370
 371 try_again:
 372
 373         if (unlikely(pcol->pg_first == -1)) {
 374                 pcol->pg_first = page->index;
 375         } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
 376                    page->index)) {
 377                 /* Discontinuity detected, split the request */
 378                 ret = read_exec(pcol);
 379                 if (unlikely(ret))
 380                         goto fail;
 381                 goto try_again;
 382         }
 383
 384         if (!pcol->pages) {
 385                 ret = pcol_try_alloc(pcol);
 386                 if (unlikely(ret))
 387                         goto fail;
 388         }
 389
 390         if (len != PAGE_CACHE_SIZE)
 391                 zero_user(page, len, PAGE_CACHE_SIZE - len);
 392
 393         EXOFS_DBGMSG2("    readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
 394                      inode->i_ino, page->index, len);
 395
 396         ret = pcol_add_page(pcol, page, len);
 397         if (ret) {
 398                 EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
 399                           "this_len=0x%zx nr_pages=%u length=0x%lx\n",
 400                           page, len, pcol->nr_pages, pcol->length);
 401
 402                 /* split the request, and start again with current page */
 403                 ret = read_exec(pcol);
 404                 if (unlikely(ret))
 405                         goto fail;
 406
 407                 goto try_again;
 408         }
 409
 410         return 0;
 411
 412 fail:
 413         /* SetPageError(page); ??? */
 414         unlock_page(page);
 415         return ret;
 416 }
 417
 418 static int exofs_readpages(struct file *file, struct address_space *mapping,
 419                            struct list_head *pages, unsigned nr_pages)
 420 {
 421         struct page_collect pcol;
 422         int ret;
 423
 424         _pcol_init(&pcol, nr_pages, mapping->host);
 425
 426         ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
 427         if (ret) {
 428                 EXOFS_ERR("read_cache_pages => %d\n", ret);
 429                 return ret;
 430         }
 431
 432         return read_exec(&pcol);
 433 }
 434
 435 static int _readpage(struct page *page, bool read_4_write)
 436 {
 437         struct page_collect pcol;
 438         int ret;
 439
 440         _pcol_init(&pcol, 1, page->mapping->host);
 441
 442         pcol.read_4_write = read_4_write;
 443         ret = readpage_strip(&pcol, page);
 444         if (ret) {
 445                 EXOFS_ERR("_readpage => %d\n", ret);
 446                 return ret;
 447         }
 448
 449         return read_exec(&pcol);
 450 }
 451
 452 /*
 453  * We don't need the file
 454  */
 455 static int exofs_readpage(struct file *file, struct page *page)
 456 {
 457         return _readpage(page, false);
 458 }
 459
 460 /* Callback for osd_write. All writes are asynchronous */
 461 static void writepages_done(struct exofs_io_state *ios, void *p)
 462 {
 463         struct page_collect *pcol = p;
 464         int i;
 465         u64 resid;
 466         u64  good_bytes;
 467         u64  length = 0;
 468         int ret = exofs_check_io(ios, &resid);
 469
 470         atomic_dec(&pcol->sbi->s_curr_pending);
 471
 472         if (likely(!ret))
 473                 good_bytes = pcol->length;
 474         else
 475                 good_bytes = pcol->length - resid;
 476
 477         EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
 478                      " length=0x%lx nr_pages=%u\n",
 479                      pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
 480                      pcol->nr_pages);
 481
 482         for (i = 0; i < pcol->nr_pages; i++) {
 483                 struct page *page = pcol->pages[i];
 484                 struct inode *inode = page->mapping->host;
 485                 int page_stat;
 486
 487                 if (inode != pcol->inode)
 488                         continue; /* osd might add more pages to a bio */
 489
 490                 if (likely(length < good_bytes))
 491                         page_stat = 0;
 492                 else
 493                         page_stat = ret;
 494
 495                 update_write_page(page, page_stat);
 496                 unlock_page(page);
 497                 EXOFS_DBGMSG2("    writepages_done(0x%lx, 0x%lx) status=%d\n",
 498                              inode->i_ino, page->index, page_stat);
 499
 500                 length += PAGE_SIZE;
 501         }
 502
 503         pcol_free(pcol);
 504         kfree(pcol);
 505         EXOFS_DBGMSG2("writepages_done END\n");
 506 }
 507
 508 static int write_exec(struct page_collect *pcol)
 509 {
 510         struct exofs_i_info *oi = exofs_i(pcol->inode);
 511         struct exofs_io_state *ios;
 512         struct page_collect *pcol_copy = NULL;
 513         int ret;
 514
 515         if (!pcol->pages)
 516                 return 0;
 517
 518         BUG_ON(pcol->ios);
 519         ret = exofs_get_rw_state(&pcol->sbi->layout, false,
 520                                  pcol->pg_first << PAGE_CACHE_SHIFT,
 521                                  pcol->length, &pcol->ios);
 522
 523         if (unlikely(ret))
 524                 goto err;
 525
 526         pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
 527         if (!pcol_copy) {
 528                 EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
 529                 ret = -ENOMEM;
 530                 goto err;
 531         }
 532
 533         *pcol_copy = *pcol;
 534
 535         ios = pcol->ios;
 536         ios->pages = pcol_copy->pages;
 537         ios->nr_pages = pcol_copy->nr_pages;
 538         ios->done = writepages_done;
 539         ios->private = pcol_copy;
 540
 541         ret = exofs_oi_write(oi, ios);
 542         if (unlikely(ret)) {
 543                 EXOFS_ERR("write_exec: exofs_oi_write() Failed\n");
 544                 goto err;
 545         }
 546
 547         atomic_inc(&pcol->sbi->s_curr_pending);
 548         EXOFS_DBGMSG2("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
 549                   pcol->inode->i_ino, pcol->pg_first, _LLU(ios->offset),
 550                   pcol->length);
 551         /* pages ownership was passed to pcol_copy */
 552         _pcol_reset(pcol);
 553         return 0;
 554
 555 err:
 556         _unlock_pcol_pages(pcol, ret, WRITE);
 557         pcol_free(pcol);
 558         kfree(pcol_copy);
 559
 560         return ret;
 561 }
 562
 563 /* writepage_strip is called either directly from writepage() or by the VFS from
 564  * within write_cache_pages(), to add one more page to be written to storage.
 565  * It will try to collect as many contiguous pages as possible. If a
 566  * discontinuity is encountered or it runs out of resources it will submit the
 567  * previous segment and will start a new collection.
 568  * Eventually caller must submit the last segment if present.
 569  */
 570 static int writepage_strip(struct page *page,
 571                            struct writeback_control *wbc_unused, void *data)
 572 {
 573         struct page_collect *pcol = data;
 574         struct inode *inode = pcol->inode;
 575         struct exofs_i_info *oi = exofs_i(inode);
 576         loff_t i_size = i_size_read(inode);
 577         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 578         size_t len;
 579         int ret;
 580
 581         BUG_ON(!PageLocked(page));
 582
 583         ret = wait_obj_created(oi);
 584         if (unlikely(ret))
 585                 goto fail;
 586
 587         if (page->index < end_index)
 588                 /* in this case, the page is within the limits of the file */
 589                 len = PAGE_CACHE_SIZE;
 590         else {
 591                 len = i_size & ~PAGE_CACHE_MASK;
 592
 593                 if (page->index > end_index || !len) {
 594                         /* in this case, the page is outside the limits
 595                          * (truncate in progress)
 596                          */
 597                         ret = write_exec(pcol);
 598                         if (unlikely(ret))
 599                                 goto fail;
 600                         if (PageError(page))
 601                                 ClearPageError(page);
 602                         unlock_page(page);
 603                         EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
 604                                      "outside the limits\n",
 605                                      inode->i_ino, page->index);
 606                         return 0;
 607                 }
 608         }
 609
 610 try_again:
 611
 612         if (unlikely(pcol->pg_first == -1)) {
 613                 pcol->pg_first = page->index;
 614         } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
 615                    page->index)) {
 616                 /* Discontinuity detected, split the request */
 617                 ret = write_exec(pcol);
 618                 if (unlikely(ret))
 619                         goto fail;
 620
 621                 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
 622                              inode->i_ino, page->index);
 623                 goto try_again;
 624         }
 625
 626         if (!pcol->pages) {
 627                 ret = pcol_try_alloc(pcol);
 628                 if (unlikely(ret))
 629                         goto fail;
 630         }
 631
 632         EXOFS_DBGMSG2("    writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
 633                      inode->i_ino, page->index, len);
 634
 635         ret = pcol_add_page(pcol, page, len);
 636         if (unlikely(ret)) {
 637                 EXOFS_DBGMSG2("Failed pcol_add_page "
 638                              "nr_pages=%u total_length=0x%lx\n",
 639                              pcol->nr_pages, pcol->length);
 640
 641                 /* split the request, next loop will start again */
 642                 ret = write_exec(pcol);
 643                 if (unlikely(ret)) {
 644                         EXOFS_DBGMSG("write_exec failed => %d", ret);
 645                         goto fail;
 646                 }
 647
 648                 goto try_again;
 649         }
 650
 651         BUG_ON(PageWriteback(page));
 652         set_page_writeback(page);
 653
 654         return 0;
 655
 656 fail:
 657         EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
 658                      inode->i_ino, page->index, ret);
 659         set_bit(AS_EIO, &page->mapping->flags);
 660         unlock_page(page);
 661         return ret;
 662 }
 663
 664 static int exofs_writepages(struct address_space *mapping,
 665                        struct writeback_control *wbc)
 666 {
 667         struct page_collect pcol;
 668         long start, end, expected_pages;
 669         int ret;
 670
 671         start = wbc->range_start >> PAGE_CACHE_SHIFT;
 672         end = (wbc->range_end == LLONG_MAX) ?
 673                         start + mapping->nrpages :
 674                         wbc->range_end >> PAGE_CACHE_SHIFT;
 675
 676         if (start || end)
 677                 expected_pages = end - start + 1;
 678         else
 679                 expected_pages = mapping->nrpages;
 680
 681         if (expected_pages < 32L)
 682                 expected_pages = 32L;
 683
 684         EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
 685                      "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
 686                      mapping->host->i_ino, wbc->range_start, wbc->range_end,
 687                      mapping->nrpages, start, end, expected_pages);
 688
 689         _pcol_init(&pcol, expected_pages, mapping->host);
 690
 691         ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
 692         if (ret) {
 693                 EXOFS_ERR("write_cache_pages => %d\n", ret);
 694                 return ret;
 695         }
 696
 697         return write_exec(&pcol);
 698 }
 699
 700 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
 701 {
 702         struct page_collect pcol;
 703         int ret;
 704
 705         _pcol_init(&pcol, 1, page->mapping->host);
 706
 707         ret = writepage_strip(page, NULL, &pcol);
 708         if (ret) {
 709                 EXOFS_ERR("exofs_writepage => %d\n", ret);
 710                 return ret;
 711         }
 712
 713         return write_exec(&pcol);
 714 }
 715
 716 /* i_mutex held using inode->i_size directly */
 717 static void _write_failed(struct inode *inode, loff_t to)
 718 {
 719         if (to > inode->i_size)
 720                 truncate_pagecache(inode, to, inode->i_size);
 721 }
 722
 723 int exofs_write_begin(struct file *file, struct address_space *mapping,
 724                 loff_t pos, unsigned len, unsigned flags,
 725                 struct page **pagep, void **fsdata)
 726 {
 727         int ret = 0;
 728         struct page *page;
 729
 730         page = *pagep;
 731         if (page == NULL) {
 732                 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
 733                                          fsdata);
 734                 if (ret) {
 735                         EXOFS_DBGMSG("simple_write_begin failed\n");
 736                         goto out;
 737                 }
 738
 739                 page = *pagep;
 740         }
 741
 742          /* read modify write */
 743         if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
 744                 loff_t i_size = i_size_read(mapping->host);
 745                 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 746                 size_t rlen;
 747
 748                 if (page->index < end_index)
 749                         rlen = PAGE_CACHE_SIZE;
 750                 else if (page->index == end_index)
 751                         rlen = i_size & ~PAGE_CACHE_MASK;
 752                 else
 753                         rlen = 0;
 754
 755                 if (!rlen) {
 756                         clear_highpage(page);
 757                         SetPageUptodate(page);
 758                         goto out;
 759                 }
 760
 761                 ret = _readpage(page, true);
 762                 if (ret) {
 763                         /*SetPageError was done by _readpage. Is it ok?*/
 764                         unlock_page(page);
 765                         EXOFS_DBGMSG("__readpage failed\n");
 766                 }
 767         }
 768 out:
 769         if (unlikely(ret))
 770                 _write_failed(mapping->host, pos + len);
 771
 772         return ret;
 773 }
 774
 775 static int exofs_write_begin_export(struct file *file,
 776                 struct address_space *mapping,
 777                 loff_t pos, unsigned len, unsigned flags,
 778                 struct page **pagep, void **fsdata)
 779 {
 780         *pagep = NULL;
 781
 782         return exofs_write_begin(file, mapping, pos, len, flags, pagep,
 783                                         fsdata);
 784 }
 785
 786 static int exofs_write_end(struct file *file, struct address_space *mapping,
 787                         loff_t pos, unsigned len, unsigned copied,
 788                         struct page *page, void *fsdata)
 789 {
 790         struct inode *inode = mapping->host;
 791         /* According to comment in simple_write_end i_mutex is held */
 792         loff_t i_size = inode->i_size;
 793         int ret;
 794
 795         ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
 796         if (unlikely(ret))
 797                 _write_failed(inode, pos + len);
 798
 799         /* TODO: once simple_write_end marks inode dirty remove */
 800         if (i_size != inode->i_size)
 801                 mark_inode_dirty(inode);
 802         return ret;
 803 }
 804
 805 static int exofs_releasepage(struct page *page, gfp_t gfp)
 806 {
 807         EXOFS_DBGMSG("page 0x%lx\n", page->index);
 808         WARN_ON(1);
 809         return 0;
 810 }
 811
 812 static void exofs_invalidatepage(struct page *page, unsigned long offset)
 813 {
 814         EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
 815         WARN_ON(1);
 816 }
 817
 818 const struct address_space_operations exofs_aops = {
 819         .readpage       = exofs_readpage,
 820         .readpages      = exofs_readpages,
 821         .writepage      = exofs_writepage,
 822         .writepages     = exofs_writepages,
 823         .write_begin    = exofs_write_begin_export,
 824         .write_end      = exofs_write_end,
 825         .releasepage    = exofs_releasepage,
 826         .set_page_dirty = __set_page_dirty_nobuffers,
 827         .invalidatepage = exofs_invalidatepage,
 828
 829         /* Not implemented Yet */
 830         .bmap           = NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
 831         .direct_IO      = NULL, /* TODO: Should be trivial to do */
 832
 833         /* With these NULL has special meaning or default is not exported */
 834         .get_xip_mem    = NULL,
 835         .migratepage    = NULL,
 836         .launder_page   = NULL,
 837         .is_partially_uptodate = NULL,
 838         .error_remove_page = NULL,
 839 };
 840
 841 /******************************************************************************
 842  * INODE OPERATIONS
 843  *****************************************************************************/
 844
 845 /*
 846  * Test whether an inode is a fast symlink.
 847  */
 848 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
 849 {
 850         struct exofs_i_info *oi = exofs_i(inode);
 851
 852         return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
 853 }
 854
 855 static int _do_truncate(struct inode *inode, loff_t newsize)
 856 {
 857         struct exofs_i_info *oi = exofs_i(inode);
 858         int ret;
 859
 860         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 861
 862         ret = exofs_oi_truncate(oi, (u64)newsize);
 863         if (likely(!ret))
 864                 truncate_setsize(inode, newsize);
 865
 866         EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
 867                      inode->i_ino, newsize, ret);
 868         return ret;
 869 }
 870
 871 /*
 872  * Set inode attributes - update size attribute on OSD if needed,
 873  *                        otherwise just call generic functions.
 874  */
 875 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
 876 {
 877         struct inode *inode = dentry->d_inode;
 878         int error;
 879
 880         /* if we are about to modify an object, and it hasn't been
 881          * created yet, wait
 882          */
 883         error = wait_obj_created(exofs_i(inode));
 884         if (unlikely(error))
 885                 return error;
 886
 887         error = inode_change_ok(inode, iattr);
 888         if (unlikely(error))
 889                 return error;
 890
 891         if ((iattr->ia_valid & ATTR_SIZE) &&
 892             iattr->ia_size != i_size_read(inode)) {
 893                 error = _do_truncate(inode, iattr->ia_size);
 894                 if (unlikely(error))
 895                         return error;
 896         }
 897
 898         setattr_copy(inode, iattr);
 899         mark_inode_dirty(inode);
 900         return 0;
 901 }
 902
 903 static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
 904         EXOFS_APAGE_FS_DATA,
 905         EXOFS_ATTR_INODE_FILE_LAYOUT,
 906         0);
 907 static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
 908         EXOFS_APAGE_FS_DATA,
 909         EXOFS_ATTR_INODE_DIR_LAYOUT,
 910         0);
 911
 912 /*
 913  * Read the Linux inode info from the OSD, and return it as is. In exofs the
 914  * inode info is in an application specific page/attribute of the osd-object.
 915  */
 916 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
 917                     struct exofs_fcb *inode)
 918 {
 919         struct exofs_sb_info *sbi = sb->s_fs_info;
 920         struct osd_attr attrs[] = {
 921                 [0] = g_attr_inode_data,
 922                 [1] = g_attr_inode_file_layout,
 923                 [2] = g_attr_inode_dir_layout,
 924         };
 925         struct exofs_io_state *ios;
 926         struct exofs_on_disk_inode_layout *layout;
 927         int ret;
 928
 929         ret = exofs_get_io_state(&sbi->layout, &ios);
 930         if (unlikely(ret)) {
 931                 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
 932                 return ret;
 933         }
 934
 935         ios->obj.id = exofs_oi_objno(oi);
 936         exofs_make_credential(oi->i_cred, &ios->obj);
 937         ios->cred = oi->i_cred;
 938
 939         attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
 940         attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
 941
 942         ios->in_attr = attrs;
 943         ios->in_attr_len = ARRAY_SIZE(attrs);
 944
 945         ret = exofs_sbi_read(ios);
 946         if (unlikely(ret)) {
 947                 EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
 948                           _LLU(ios->obj.id), ret);
 949                 memset(inode, 0, sizeof(*inode));
 950                 inode->i_mode = 0040000 | (0777 & ~022);
 951                 /* If object is lost on target we might as well enable it's
 952                  * delete.
 953                  */
 954                 if ((ret == -ENOENT) || (ret == -EINVAL))
 955                         ret = 0;
 956                 goto out;
 957         }
 958
 959         ret = extract_attr_from_ios(ios, &attrs[0]);
 960         if (ret) {
 961                 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
 962                 goto out;
 963         }
 964         WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
 965         memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
 966
 967         ret = extract_attr_from_ios(ios, &attrs[1]);
 968         if (ret) {
 969                 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
 970                 goto out;
 971         }
 972         if (attrs[1].len) {
 973                 layout = attrs[1].val_ptr;
 974                 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
 975                         EXOFS_ERR("%s: unsupported files layout %d\n",
 976                                 __func__, layout->gen_func);
 977                         ret = -ENOTSUPP;
 978                         goto out;
 979                 }
 980         }
 981
 982         ret = extract_attr_from_ios(ios, &attrs[2]);
 983         if (ret) {
 984                 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
 985                 goto out;
 986         }
 987         if (attrs[2].len) {
 988                 layout = attrs[2].val_ptr;
 989                 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
 990                         EXOFS_ERR("%s: unsupported meta-data layout %d\n",
 991                                 __func__, layout->gen_func);
 992                         ret = -ENOTSUPP;
 993                         goto out;
 994                 }
 995         }
 996
 997 out:
 998         exofs_put_io_state(ios);
 999         return ret;
1000 }
1001
1002 static void __oi_init(struct exofs_i_info *oi)
1003 {
1004         init_waitqueue_head(&oi->i_wq);
1005         oi->i_flags = 0;
1006 }
1007 /*
1008  * Fill in an inode read from the OSD and set it up for use
1009  */
1010 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
1011 {
1012         struct exofs_i_info *oi;
1013         struct exofs_fcb fcb;
1014         struct inode *inode;
1015         int ret;
1016
1017         inode = iget_locked(sb, ino);
1018         if (!inode)
1019                 return ERR_PTR(-ENOMEM);
1020         if (!(inode->i_state & I_NEW))
1021                 return inode;
1022         oi = exofs_i(inode);
1023         __oi_init(oi);
1024
1025         /* read the inode from the osd */
1026         ret = exofs_get_inode(sb, oi, &fcb);
1027         if (ret)
1028                 goto bad_inode;
1029
1030         set_obj_created(oi);
1031
1032         /* copy stuff from on-disk struct to in-memory struct */
1033         inode->i_mode = le16_to_cpu(fcb.i_mode);
1034         inode->i_uid = le32_to_cpu(fcb.i_uid);
1035         inode->i_gid = le32_to_cpu(fcb.i_gid);
1036         inode->i_nlink = le16_to_cpu(fcb.i_links_count);
1037         inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
1038         inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
1039         inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
1040         inode->i_ctime.tv_nsec =
1041                 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1042         oi->i_commit_size = le64_to_cpu(fcb.i_size);
1043         i_size_write(inode, oi->i_commit_size);
1044         inode->i_blkbits = EXOFS_BLKSHIFT;
1045         inode->i_generation = le32_to_cpu(fcb.i_generation);
1046
1047         oi->i_dir_start_lookup = 0;
1048
1049         if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
1050                 ret = -ESTALE;
1051                 goto bad_inode;
1052         }
1053
1054         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1055                 if (fcb.i_data[0])
1056                         inode->i_rdev =
1057                                 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
1058                 else
1059                         inode->i_rdev =
1060                                 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
1061         } else {
1062                 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
1063         }
1064
1065         inode->i_mapping->backing_dev_info = sb->s_bdi;
1066         if (S_ISREG(inode->i_mode)) {
1067                 inode->i_op = &exofs_file_inode_operations;
1068                 inode->i_fop = &exofs_file_operations;
1069                 inode->i_mapping->a_ops = &exofs_aops;
1070         } else if (S_ISDIR(inode->i_mode)) {
1071                 inode->i_op = &exofs_dir_inode_operations;
1072                 inode->i_fop = &exofs_dir_operations;
1073                 inode->i_mapping->a_ops = &exofs_aops;
1074         } else if (S_ISLNK(inode->i_mode)) {
1075                 if (exofs_inode_is_fast_symlink(inode))
1076                         inode->i_op = &exofs_fast_symlink_inode_operations;
1077                 else {
1078                         inode->i_op = &exofs_symlink_inode_operations;
1079                         inode->i_mapping->a_ops = &exofs_aops;
1080                 }
1081         } else {
1082                 inode->i_op = &exofs_special_inode_operations;
1083                 if (fcb.i_data[0])
1084                         init_special_inode(inode, inode->i_mode,
1085                            old_decode_dev(le32_to_cpu(fcb.i_data[0])));
1086                 else
1087                         init_special_inode(inode, inode->i_mode,
1088                            new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1089         }
1090
1091         unlock_new_inode(inode);
1092         return inode;
1093
1094 bad_inode:
1095         iget_failed(inode);
1096         return ERR_PTR(ret);
1097 }
1098
1099 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1100 {
1101         if (!obj_created(oi)) {
1102                 EXOFS_DBGMSG("!obj_created\n");
1103                 BUG_ON(!obj_2bcreated(oi));
1104                 wait_event(oi->i_wq, obj_created(oi));
1105                 EXOFS_DBGMSG("wait_event done\n");
1106         }
1107         return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1108 }
1109
1110 /*
1111  * Callback function from exofs_new_inode().  The important thing is that we
1112  * set the obj_created flag so that other methods know that the object exists on
1113  * the OSD.
1114  */
1115 static void create_done(struct exofs_io_state *ios, void *p)
1116 {
1117         struct inode *inode = p;
1118         struct exofs_i_info *oi = exofs_i(inode);
1119         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1120         int ret;
1121
1122         ret = exofs_check_io(ios, NULL);
1123         exofs_put_io_state(ios);
1124
1125         atomic_dec(&sbi->s_curr_pending);
1126
1127         if (unlikely(ret)) {
1128                 EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
1129                           _LLU(exofs_oi_objno(oi)), _LLU(sbi->layout.s_pid));
1130                 /*TODO: When FS is corrupted creation can fail, object already
1131                  * exist. Get rid of this asynchronous creation, if exist
1132                  * increment the obj counter and try the next object. Until we
1133                  * succeed. All these dangling objects will be made into lost
1134                  * files by chkfs.exofs
1135                  */
1136         }
1137
1138         set_obj_created(oi);
1139
1140         wake_up(&oi->i_wq);
1141 }
1142
1143 /*
1144  * Set up a new inode and create an object for it on the OSD
1145  */
1146 struct inode *exofs_new_inode(struct inode *dir, int mode)
1147 {
1148         struct super_block *sb;
1149         struct inode *inode;
1150         struct exofs_i_info *oi;
1151         struct exofs_sb_info *sbi;
1152         struct exofs_io_state *ios;
1153         int ret;
1154
1155         sb = dir->i_sb;
1156         inode = new_inode(sb);
1157         if (!inode)
1158                 return ERR_PTR(-ENOMEM);
1159
1160         oi = exofs_i(inode);
1161         __oi_init(oi);
1162
1163         set_obj_2bcreated(oi);
1164
1165         sbi = sb->s_fs_info;
1166
1167         inode->i_mapping->backing_dev_info = sb->s_bdi;
1168         inode_init_owner(inode, dir, mode);
1169         inode->i_ino = sbi->s_nextid++;
1170         inode->i_blkbits = EXOFS_BLKSHIFT;
1171         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1172         oi->i_commit_size = inode->i_size = 0;
1173         spin_lock(&sbi->s_next_gen_lock);
1174         inode->i_generation = sbi->s_next_generation++;
1175         spin_unlock(&sbi->s_next_gen_lock);
1176         insert_inode_hash(inode);
1177
1178         exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
1179
1180         mark_inode_dirty(inode);
1181
1182         ret = exofs_get_io_state(&sbi->layout, &ios);
1183         if (unlikely(ret)) {
1184                 EXOFS_ERR("exofs_new_inode: exofs_get_io_state failed\n");
1185                 return ERR_PTR(ret);
1186         }
1187
1188         ios->obj.id = exofs_oi_objno(oi);
1189         exofs_make_credential(oi->i_cred, &ios->obj);
1190
1191         ios->done = create_done;
1192         ios->private = inode;
1193         ios->cred = oi->i_cred;
1194         ret = exofs_sbi_create(ios);
1195         if (ret) {
1196                 exofs_put_io_state(ios);
1197                 return ERR_PTR(ret);
1198         }
1199         atomic_inc(&sbi->s_curr_pending);
1200
1201         return inode;
1202 }
1203
1204 /*
1205  * struct to pass two arguments to update_inode's callback
1206  */
1207 struct updatei_args {
1208         struct exofs_sb_info    *sbi;
1209         struct exofs_fcb        fcb;
1210 };
1211
1212 /*
1213  * Callback function from exofs_update_inode().
1214  */
1215 static void updatei_done(struct exofs_io_state *ios, void *p)
1216 {
1217         struct updatei_args *args = p;
1218
1219         exofs_put_io_state(ios);
1220
1221         atomic_dec(&args->sbi->s_curr_pending);
1222
1223         kfree(args);
1224 }
1225
1226 /*
1227  * Write the inode to the OSD.  Just fill up the struct, and set the attribute
1228  * synchronously or asynchronously depending on the do_sync flag.
1229  */
1230 static int exofs_update_inode(struct inode *inode, int do_sync)
1231 {
1232         struct exofs_i_info *oi = exofs_i(inode);
1233         struct super_block *sb = inode->i_sb;
1234         struct exofs_sb_info *sbi = sb->s_fs_info;
1235         struct exofs_io_state *ios;
1236         struct osd_attr attr;
1237         struct exofs_fcb *fcb;
1238         struct updatei_args *args;
1239         int ret;
1240
1241         args = kzalloc(sizeof(*args), GFP_KERNEL);
1242         if (!args) {
1243                 EXOFS_DBGMSG("Failed kzalloc of args\n");
1244                 return -ENOMEM;
1245         }
1246
1247         fcb = &args->fcb;
1248
1249         fcb->i_mode = cpu_to_le16(inode->i_mode);
1250         fcb->i_uid = cpu_to_le32(inode->i_uid);
1251         fcb->i_gid = cpu_to_le32(inode->i_gid);
1252         fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1253         fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1254         fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1255         fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1256         oi->i_commit_size = i_size_read(inode);
1257         fcb->i_size = cpu_to_le64(oi->i_commit_size);
1258         fcb->i_generation = cpu_to_le32(inode->i_generation);
1259
1260         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1261                 if (old_valid_dev(inode->i_rdev)) {
1262                         fcb->i_data[0] =
1263                                 cpu_to_le32(old_encode_dev(inode->i_rdev));
1264                         fcb->i_data[1] = 0;
1265                 } else {
1266                         fcb->i_data[0] = 0;
1267                         fcb->i_data[1] =
1268                                 cpu_to_le32(new_encode_dev(inode->i_rdev));
1269                         fcb->i_data[2] = 0;
1270                 }
1271         } else
1272                 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1273
1274         ret = exofs_get_io_state(&sbi->layout, &ios);
1275         if (unlikely(ret)) {
1276                 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
1277                 goto free_args;
1278         }
1279
1280         attr = g_attr_inode_data;
1281         attr.val_ptr = fcb;
1282         ios->out_attr_len = 1;
1283         ios->out_attr = &attr;
1284
1285         wait_obj_created(oi);
1286
1287         if (!do_sync) {
1288                 args->sbi = sbi;
1289                 ios->done = updatei_done;
1290                 ios->private = args;
1291         }
1292
1293         ret = exofs_oi_write(oi, ios);
1294         if (!do_sync && !ret) {
1295                 atomic_inc(&sbi->s_curr_pending);
1296                 goto out; /* deallocation in updatei_done */
1297         }
1298
1299         exofs_put_io_state(ios);
1300 free_args:
1301         kfree(args);
1302 out:
1303         EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
1304                      inode->i_ino, do_sync, ret);
1305         return ret;
1306 }
1307
1308 int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
1309 {
1310         /* FIXME: fix fsync and use wbc->sync_mode == WB_SYNC_ALL */
1311         return exofs_update_inode(inode, 1);
1312 }
1313
1314 /*
1315  * Callback function from exofs_delete_inode() - don't have much cleaning up to
1316  * do.
1317  */
1318 static void delete_done(struct exofs_io_state *ios, void *p)
1319 {
1320         struct exofs_sb_info *sbi = p;
1321
1322         exofs_put_io_state(ios);
1323
1324         atomic_dec(&sbi->s_curr_pending);
1325 }
1326
1327 /*
1328  * Called when the refcount of an inode reaches zero.  We remove the object
1329  * from the OSD here.  We make sure the object was created before we try and
1330  * delete it.
1331  */
1332 void exofs_evict_inode(struct inode *inode)
1333 {
1334         struct exofs_i_info *oi = exofs_i(inode);
1335         struct super_block *sb = inode->i_sb;
1336         struct exofs_sb_info *sbi = sb->s_fs_info;
1337         struct exofs_io_state *ios;
1338         int ret;
1339
1340         truncate_inode_pages(&inode->i_data, 0);
1341
1342         /* TODO: should do better here */
1343         if (inode->i_nlink || is_bad_inode(inode))
1344                 goto no_delete;
1345
1346         inode->i_size = 0;
1347         end_writeback(inode);
1348
1349         /* if we are deleting an obj that hasn't been created yet, wait.
1350          * This also makes sure that create_done cannot be called with an
1351          * already evicted inode.
1352          */
1353         wait_obj_created(oi);
1354         /* ignore the error, attempt a remove anyway */
1355
1356         /* Now Remove the OSD objects */
1357         ret = exofs_get_io_state(&sbi->layout, &ios);
1358         if (unlikely(ret)) {
1359                 EXOFS_ERR("%s: exofs_get_io_state failed\n", __func__);
1360                 return;
1361         }
1362
1363         ios->obj.id = exofs_oi_objno(oi);
1364         ios->done = delete_done;
1365         ios->private = sbi;
1366         ios->cred = oi->i_cred;
1367         ret = exofs_sbi_remove(ios);
1368         if (ret) {
1369                 EXOFS_ERR("%s: exofs_sbi_remove failed\n", __func__);
1370                 exofs_put_io_state(ios);
1371                 return;
1372         }
1373         atomic_inc(&sbi->s_curr_pending);
1374
1375         return;
1376
1377 no_delete:
1378         end_writeback(inode);
1379 }