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