fs/gfs2/aops.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/pagevec.h>
  17 #include <linux/mpage.h>
  18 #include <linux/fs.h>
  19 #include <linux/writeback.h>
  20 #include <linux/swap.h>
  21 #include <linux/gfs2_ondisk.h>
  22 #include <linux/backing-dev.h>
  23 #include <linux/uio.h>
  24 #include <trace/events/writeback.h>
  25 #include <linux/sched/signal.h>
  26
  27 #include "gfs2.h"
  28 #include "incore.h"
  29 #include "bmap.h"
  30 #include "glock.h"
  31 #include "inode.h"
  32 #include "log.h"
  33 #include "meta_io.h"
  34 #include "quota.h"
  35 #include "trans.h"
  36 #include "rgrp.h"
  37 #include "super.h"
  38 #include "util.h"
  39 #include "glops.h"
  40 #include "aops.h"
  41
  42
  43 void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
  44                             unsigned int from, unsigned int len)
  45 {
  46         struct buffer_head *head = page_buffers(page);
  47         unsigned int bsize = head->b_size;
  48         struct buffer_head *bh;
  49         unsigned int to = from + len;
  50         unsigned int start, end;
  51
  52         for (bh = head, start = 0; bh != head || !start;
  53              bh = bh->b_this_page, start = end) {
  54                 end = start + bsize;
  55                 if (end <= from)
  56                         continue;
  57                 if (start >= to)
  58                         break;
  59                 set_buffer_uptodate(bh);
  60                 gfs2_trans_add_data(ip->i_gl, bh);
  61         }
  62 }
  63
  64 /**
  65  * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
  66  * @inode: The inode
  67  * @lblock: The block number to look up
  68  * @bh_result: The buffer head to return the result in
  69  * @create: Non-zero if we may add block to the file
  70  *
  71  * Returns: errno
  72  */
  73
  74 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
  75                                   struct buffer_head *bh_result, int create)
  76 {
  77         int error;
  78
  79         error = gfs2_block_map(inode, lblock, bh_result, 0);
  80         if (error)
  81                 return error;
  82         if (!buffer_mapped(bh_result))
  83                 return -EIO;
  84         return 0;
  85 }
  86
  87 /**
  88  * gfs2_writepage_common - Common bits of writepage
  89  * @page: The page to be written
  90  * @wbc: The writeback control
  91  *
  92  * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
  93  */
  94
  95 static int gfs2_writepage_common(struct page *page,
  96                                  struct writeback_control *wbc)
  97 {
  98         struct inode *inode = page->mapping->host;
  99         struct gfs2_inode *ip = GFS2_I(inode);
 100         struct gfs2_sbd *sdp = GFS2_SB(inode);
 101         loff_t i_size = i_size_read(inode);
 102         pgoff_t end_index = i_size >> PAGE_SHIFT;
 103         unsigned offset;
 104
 105         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
 106                 goto out;
 107         if (current->journal_info)
 108                 goto redirty;
 109         /* Is the page fully outside i_size? (truncate in progress) */
 110         offset = i_size & (PAGE_SIZE-1);
 111         if (page->index > end_index || (page->index == end_index && !offset)) {
 112                 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
 113                 goto out;
 114         }
 115         return 1;
 116 redirty:
 117         redirty_page_for_writepage(wbc, page);
 118 out:
 119         unlock_page(page);
 120         return 0;
 121 }
 122
 123 /**
 124  * gfs2_writepage - Write page for writeback mappings
 125  * @page: The page
 126  * @wbc: The writeback control
 127  *
 128  */
 129
 130 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
 131 {
 132         int ret;
 133
 134         ret = gfs2_writepage_common(page, wbc);
 135         if (ret <= 0)
 136                 return ret;
 137
 138         return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
 139 }
 140
 141 /* This is the same as calling block_write_full_page, but it also
 142  * writes pages outside of i_size
 143  */
 144 static int gfs2_write_full_page(struct page *page, get_block_t *get_block,
 145                                 struct writeback_control *wbc)
 146 {
 147         struct inode * const inode = page->mapping->host;
 148         loff_t i_size = i_size_read(inode);
 149         const pgoff_t end_index = i_size >> PAGE_SHIFT;
 150         unsigned offset;
 151
 152         /*
 153          * The page straddles i_size.  It must be zeroed out on each and every
 154          * writepage invocation because it may be mmapped.  "A file is mapped
 155          * in multiples of the page size.  For a file that is not a multiple of
 156          * the  page size, the remaining memory is zeroed when mapped, and
 157          * writes to that region are not written out to the file."
 158          */
 159         offset = i_size & (PAGE_SIZE-1);
 160         if (page->index == end_index && offset)
 161                 zero_user_segment(page, offset, PAGE_SIZE);
 162
 163         return __block_write_full_page(inode, page, get_block, wbc,
 164                                        end_buffer_async_write);
 165 }
 166
 167 /**
 168  * __gfs2_jdata_writepage - The core of jdata writepage
 169  * @page: The page to write
 170  * @wbc: The writeback control
 171  *
 172  * This is shared between writepage and writepages and implements the
 173  * core of the writepage operation. If a transaction is required then
 174  * PageChecked will have been set and the transaction will have
 175  * already been started before this is called.
 176  */
 177
 178 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
 179 {
 180         struct inode *inode = page->mapping->host;
 181         struct gfs2_inode *ip = GFS2_I(inode);
 182         struct gfs2_sbd *sdp = GFS2_SB(inode);
 183
 184         if (PageChecked(page)) {
 185                 ClearPageChecked(page);
 186                 if (!page_has_buffers(page)) {
 187                         create_empty_buffers(page, inode->i_sb->s_blocksize,
 188                                              BIT(BH_Dirty)|BIT(BH_Uptodate));
 189                 }
 190                 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
 191         }
 192         return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
 193 }
 194
 195 /**
 196  * gfs2_jdata_writepage - Write complete page
 197  * @page: Page to write
 198  * @wbc: The writeback control
 199  *
 200  * Returns: errno
 201  *
 202  */
 203
 204 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
 205 {
 206         struct inode *inode = page->mapping->host;
 207         struct gfs2_inode *ip = GFS2_I(inode);
 208         struct gfs2_sbd *sdp = GFS2_SB(inode);
 209         int ret;
 210
 211         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
 212                 goto out;
 213         if (PageChecked(page) || current->journal_info)
 214                 goto out_ignore;
 215         ret = __gfs2_jdata_writepage(page, wbc);
 216         return ret;
 217
 218 out_ignore:
 219         redirty_page_for_writepage(wbc, page);
 220 out:
 221         unlock_page(page);
 222         return 0;
 223 }
 224
 225 /**
 226  * gfs2_writepages - Write a bunch of dirty pages back to disk
 227  * @mapping: The mapping to write
 228  * @wbc: Write-back control
 229  *
 230  * Used for both ordered and writeback modes.
 231  */
 232 static int gfs2_writepages(struct address_space *mapping,
 233                            struct writeback_control *wbc)
 234 {
 235         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 236         int ret = mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
 237
 238         /*
 239          * Even if we didn't write any pages here, we might still be holding
 240          * dirty pages in the ail. We forcibly flush the ail because we don't
 241          * want balance_dirty_pages() to loop indefinitely trying to write out
 242          * pages held in the ail that it can't find.
 243          */
 244         if (ret == 0)
 245                 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
 246
 247         return ret;
 248 }
 249
 250 /**
 251  * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
 252  * @mapping: The mapping
 253  * @wbc: The writeback control
 254  * @pvec: The vector of pages
 255  * @nr_pages: The number of pages to write
 256  * @done_index: Page index
 257  *
 258  * Returns: non-zero if loop should terminate, zero otherwise
 259  */
 260
 261 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
 262                                     struct writeback_control *wbc,
 263                                     struct pagevec *pvec,
 264                                     int nr_pages,
 265                                     pgoff_t *done_index)
 266 {
 267         struct inode *inode = mapping->host;
 268         struct gfs2_sbd *sdp = GFS2_SB(inode);
 269         unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
 270         int i;
 271         int ret;
 272
 273         ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
 274         if (ret < 0)
 275                 return ret;
 276
 277         for(i = 0; i < nr_pages; i++) {
 278                 struct page *page = pvec->pages[i];
 279
 280                 *done_index = page->index;
 281
 282                 lock_page(page);
 283
 284                 if (unlikely(page->mapping != mapping)) {
 285 continue_unlock:
 286                         unlock_page(page);
 287                         continue;
 288                 }
 289
 290                 if (!PageDirty(page)) {
 291                         /* someone wrote it for us */
 292                         goto continue_unlock;
 293                 }
 294
 295                 if (PageWriteback(page)) {
 296                         if (wbc->sync_mode != WB_SYNC_NONE)
 297                                 wait_on_page_writeback(page);
 298                         else
 299                                 goto continue_unlock;
 300                 }
 301
 302                 BUG_ON(PageWriteback(page));
 303                 if (!clear_page_dirty_for_io(page))
 304                         goto continue_unlock;
 305
 306                 trace_wbc_writepage(wbc, inode_to_bdi(inode));
 307
 308                 ret = __gfs2_jdata_writepage(page, wbc);
 309                 if (unlikely(ret)) {
 310                         if (ret == AOP_WRITEPAGE_ACTIVATE) {
 311                                 unlock_page(page);
 312                                 ret = 0;
 313                         } else {
 314
 315                                 /*
 316                                  * done_index is set past this page,
 317                                  * so media errors will not choke
 318                                  * background writeout for the entire
 319                                  * file. This has consequences for
 320                                  * range_cyclic semantics (ie. it may
 321                                  * not be suitable for data integrity
 322                                  * writeout).
 323                                  */
 324                                 *done_index = page->index + 1;
 325                                 ret = 1;
 326                                 break;
 327                         }
 328                 }
 329
 330                 /*
 331                  * We stop writing back only if we are not doing
 332                  * integrity sync. In case of integrity sync we have to
 333                  * keep going until we have written all the pages
 334                  * we tagged for writeback prior to entering this loop.
 335                  */
 336                 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
 337                         ret = 1;
 338                         break;
 339                 }
 340
 341         }
 342         gfs2_trans_end(sdp);
 343         return ret;
 344 }
 345
 346 /**
 347  * gfs2_write_cache_jdata - Like write_cache_pages but different
 348  * @mapping: The mapping to write
 349  * @wbc: The writeback control
 350  *
 351  * The reason that we use our own function here is that we need to
 352  * start transactions before we grab page locks. This allows us
 353  * to get the ordering right.
 354  */
 355
 356 static int gfs2_write_cache_jdata(struct address_space *mapping,
 357                                   struct writeback_control *wbc)
 358 {
 359         int ret = 0;
 360         int done = 0;
 361         struct pagevec pvec;
 362         int nr_pages;
 363         pgoff_t uninitialized_var(writeback_index);
 364         pgoff_t index;
 365         pgoff_t end;
 366         pgoff_t done_index;
 367         int cycled;
 368         int range_whole = 0;
 369         int tag;
 370
 371         pagevec_init(&pvec);
 372         if (wbc->range_cyclic) {
 373                 writeback_index = mapping->writeback_index; /* prev offset */
 374                 index = writeback_index;
 375                 if (index == 0)
 376                         cycled = 1;
 377                 else
 378                         cycled = 0;
 379                 end = -1;
 380         } else {
 381                 index = wbc->range_start >> PAGE_SHIFT;
 382                 end = wbc->range_end >> PAGE_SHIFT;
 383                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 384                         range_whole = 1;
 385                 cycled = 1; /* ignore range_cyclic tests */
 386         }
 387         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 388                 tag = PAGECACHE_TAG_TOWRITE;
 389         else
 390                 tag = PAGECACHE_TAG_DIRTY;
 391
 392 retry:
 393         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 394                 tag_pages_for_writeback(mapping, index, end);
 395         done_index = index;
 396         while (!done && (index <= end)) {
 397                 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
 398                                 tag);
 399                 if (nr_pages == 0)
 400                         break;
 401
 402                 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index);
 403                 if (ret)
 404                         done = 1;
 405                 if (ret > 0)
 406                         ret = 0;
 407                 pagevec_release(&pvec);
 408                 cond_resched();
 409         }
 410
 411         if (!cycled && !done) {
 412                 /*
 413                  * range_cyclic:
 414                  * We hit the last page and there is more work to be done: wrap
 415                  * back to the start of the file
 416                  */
 417                 cycled = 1;
 418                 index = 0;
 419                 end = writeback_index - 1;
 420                 goto retry;
 421         }
 422
 423         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
 424                 mapping->writeback_index = done_index;
 425
 426         return ret;
 427 }
 428
 429
 430 /**
 431  * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
 432  * @mapping: The mapping to write
 433  * @wbc: The writeback control
 434  *
 435  */
 436
 437 static int gfs2_jdata_writepages(struct address_space *mapping,
 438                                  struct writeback_control *wbc)
 439 {
 440         struct gfs2_inode *ip = GFS2_I(mapping->host);
 441         struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
 442         int ret;
 443
 444         ret = gfs2_write_cache_jdata(mapping, wbc);
 445         if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
 446                 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
 447                                GFS2_LFC_JDATA_WPAGES);
 448                 ret = gfs2_write_cache_jdata(mapping, wbc);
 449         }
 450         return ret;
 451 }
 452
 453 /**
 454  * stuffed_readpage - Fill in a Linux page with stuffed file data
 455  * @ip: the inode
 456  * @page: the page
 457  *
 458  * Returns: errno
 459  */
 460
 461 int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 462 {
 463         struct buffer_head *dibh;
 464         u64 dsize = i_size_read(&ip->i_inode);
 465         void *kaddr;
 466         int error;
 467
 468         /*
 469          * Due to the order of unstuffing files and ->fault(), we can be
 470          * asked for a zero page in the case of a stuffed file being extended,
 471          * so we need to supply one here. It doesn't happen often.
 472          */
 473         if (unlikely(page->index)) {
 474                 zero_user(page, 0, PAGE_SIZE);
 475                 SetPageUptodate(page);
 476                 return 0;
 477         }
 478
 479         error = gfs2_meta_inode_buffer(ip, &dibh);
 480         if (error)
 481                 return error;
 482
 483         kaddr = kmap_atomic(page);
 484         if (dsize > gfs2_max_stuffed_size(ip))
 485                 dsize = gfs2_max_stuffed_size(ip);
 486         memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
 487         memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
 488         kunmap_atomic(kaddr);
 489         flush_dcache_page(page);
 490         brelse(dibh);
 491         SetPageUptodate(page);
 492
 493         return 0;
 494 }
 495
 496
 497 /**
 498  * __gfs2_readpage - readpage
 499  * @file: The file to read a page for
 500  * @page: The page to read
 501  *
 502  * This is the core of gfs2's readpage. It's used by the internal file
 503  * reading code as in that case we already hold the glock. Also it's
 504  * called by gfs2_readpage() once the required lock has been granted.
 505  */
 506
 507 static int __gfs2_readpage(void *file, struct page *page)
 508 {
 509         struct gfs2_inode *ip = GFS2_I(page->mapping->host);
 510         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
 511
 512         int error;
 513
 514         if (i_blocksize(page->mapping->host) == PAGE_SIZE &&
 515             !page_has_buffers(page)) {
 516                 error = iomap_readpage(page, &gfs2_iomap_ops);
 517         } else if (gfs2_is_stuffed(ip)) {
 518                 error = stuffed_readpage(ip, page);
 519                 unlock_page(page);
 520         } else {
 521                 error = mpage_readpage(page, gfs2_block_map);
 522         }
 523
 524         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 525                 return -EIO;
 526
 527         return error;
 528 }
 529
 530 /**
 531  * gfs2_readpage - read a page of a file
 532  * @file: The file to read
 533  * @page: The page of the file
 534  *
 535  * This deals with the locking required. We have to unlock and
 536  * relock the page in order to get the locking in the right
 537  * order.
 538  */
 539
 540 static int gfs2_readpage(struct file *file, struct page *page)
 541 {
 542         struct address_space *mapping = page->mapping;
 543         struct gfs2_inode *ip = GFS2_I(mapping->host);
 544         struct gfs2_holder gh;
 545         int error;
 546
 547         unlock_page(page);
 548         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 549         error = gfs2_glock_nq(&gh);
 550         if (unlikely(error))
 551                 goto out;
 552         error = AOP_TRUNCATED_PAGE;
 553         lock_page(page);
 554         if (page->mapping == mapping && !PageUptodate(page))
 555                 error = __gfs2_readpage(file, page);
 556         else
 557                 unlock_page(page);
 558         gfs2_glock_dq(&gh);
 559 out:
 560         gfs2_holder_uninit(&gh);
 561         if (error && error != AOP_TRUNCATED_PAGE)
 562                 lock_page(page);
 563         return error;
 564 }
 565
 566 /**
 567  * gfs2_internal_read - read an internal file
 568  * @ip: The gfs2 inode
 569  * @buf: The buffer to fill
 570  * @pos: The file position
 571  * @size: The amount to read
 572  *
 573  */
 574
 575 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
 576                        unsigned size)
 577 {
 578         struct address_space *mapping = ip->i_inode.i_mapping;
 579         unsigned long index = *pos / PAGE_SIZE;
 580         unsigned offset = *pos & (PAGE_SIZE - 1);
 581         unsigned copied = 0;
 582         unsigned amt;
 583         struct page *page;
 584         void *p;
 585
 586         do {
 587                 amt = size - copied;
 588                 if (offset + size > PAGE_SIZE)
 589                         amt = PAGE_SIZE - offset;
 590                 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
 591                 if (IS_ERR(page))
 592                         return PTR_ERR(page);
 593                 p = kmap_atomic(page);
 594                 memcpy(buf + copied, p + offset, amt);
 595                 kunmap_atomic(p);
 596                 put_page(page);
 597                 copied += amt;
 598                 index++;
 599                 offset = 0;
 600         } while(copied < size);
 601         (*pos) += size;
 602         return size;
 603 }
 604
 605 /**
 606  * gfs2_readpages - Read a bunch of pages at once
 607  * @file: The file to read from
 608  * @mapping: Address space info
 609  * @pages: List of pages to read
 610  * @nr_pages: Number of pages to read
 611  *
 612  * Some notes:
 613  * 1. This is only for readahead, so we can simply ignore any things
 614  *    which are slightly inconvenient (such as locking conflicts between
 615  *    the page lock and the glock) and return having done no I/O. Its
 616  *    obviously not something we'd want to do on too regular a basis.
 617  *    Any I/O we ignore at this time will be done via readpage later.
 618  * 2. We don't handle stuffed files here we let readpage do the honours.
 619  * 3. mpage_readpages() does most of the heavy lifting in the common case.
 620  * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
 621  */
 622
 623 static int gfs2_readpages(struct file *file, struct address_space *mapping,
 624                           struct list_head *pages, unsigned nr_pages)
 625 {
 626         struct inode *inode = mapping->host;
 627         struct gfs2_inode *ip = GFS2_I(inode);
 628         struct gfs2_sbd *sdp = GFS2_SB(inode);
 629         struct gfs2_holder gh;
 630         int ret;
 631
 632         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 633         ret = gfs2_glock_nq(&gh);
 634         if (unlikely(ret))
 635                 goto out_uninit;
 636         if (!gfs2_is_stuffed(ip))
 637                 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
 638         gfs2_glock_dq(&gh);
 639 out_uninit:
 640         gfs2_holder_uninit(&gh);
 641         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 642                 ret = -EIO;
 643         return ret;
 644 }
 645
 646 /**
 647  * adjust_fs_space - Adjusts the free space available due to gfs2_grow
 648  * @inode: the rindex inode
 649  */
 650 void adjust_fs_space(struct inode *inode)
 651 {
 652         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
 653         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 654         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 655         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 656         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 657         struct buffer_head *m_bh, *l_bh;
 658         u64 fs_total, new_free;
 659
 660         /* Total up the file system space, according to the latest rindex. */
 661         fs_total = gfs2_ri_total(sdp);
 662         if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
 663                 return;
 664
 665         spin_lock(&sdp->sd_statfs_spin);
 666         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 667                               sizeof(struct gfs2_dinode));
 668         if (fs_total > (m_sc->sc_total + l_sc->sc_total))
 669                 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
 670         else
 671                 new_free = 0;
 672         spin_unlock(&sdp->sd_statfs_spin);
 673         fs_warn(sdp, "File system extended by %llu blocks.\n",
 674                 (unsigned long long)new_free);
 675         gfs2_statfs_change(sdp, new_free, new_free, 0);
 676
 677         if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
 678                 goto out;
 679         update_statfs(sdp, m_bh, l_bh);
 680         brelse(l_bh);
 681 out:
 682         brelse(m_bh);
 683 }
 684
 685 /**
 686  * gfs2_stuffed_write_end - Write end for stuffed files
 687  * @inode: The inode
 688  * @dibh: The buffer_head containing the on-disk inode
 689  * @pos: The file position
 690  * @copied: How much was actually copied by the VFS
 691  * @page: The page
 692  *
 693  * This copies the data from the page into the inode block after
 694  * the inode data structure itself.
 695  *
 696  * Returns: copied bytes or errno
 697  */
 698 int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
 699                            loff_t pos, unsigned copied,
 700                            struct page *page)
 701 {
 702         struct gfs2_inode *ip = GFS2_I(inode);
 703         u64 to = pos + copied;
 704         void *kaddr;
 705         unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
 706
 707         BUG_ON(pos + copied > gfs2_max_stuffed_size(ip));
 708
 709         kaddr = kmap_atomic(page);
 710         memcpy(buf + pos, kaddr + pos, copied);
 711         flush_dcache_page(page);
 712         kunmap_atomic(kaddr);
 713
 714         WARN_ON(!PageUptodate(page));
 715         unlock_page(page);
 716         put_page(page);
 717
 718         if (copied) {
 719                 if (inode->i_size < to)
 720                         i_size_write(inode, to);
 721                 mark_inode_dirty(inode);
 722         }
 723         return copied;
 724 }
 725
 726 /**
 727  * jdata_set_page_dirty - Page dirtying function
 728  * @page: The page to dirty
 729  *
 730  * Returns: 1 if it dirtyed the page, or 0 otherwise
 731  */
 732
 733 static int jdata_set_page_dirty(struct page *page)
 734 {
 735         SetPageChecked(page);
 736         return __set_page_dirty_buffers(page);
 737 }
 738
 739 /**
 740  * gfs2_bmap - Block map function
 741  * @mapping: Address space info
 742  * @lblock: The block to map
 743  *
 744  * Returns: The disk address for the block or 0 on hole or error
 745  */
 746
 747 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
 748 {
 749         struct gfs2_inode *ip = GFS2_I(mapping->host);
 750         struct gfs2_holder i_gh;
 751         sector_t dblock = 0;
 752         int error;
 753
 754         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 755         if (error)
 756                 return 0;
 757
 758         if (!gfs2_is_stuffed(ip))
 759                 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
 760
 761         gfs2_glock_dq_uninit(&i_gh);
 762
 763         return dblock;
 764 }
 765
 766 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
 767 {
 768         struct gfs2_bufdata *bd;
 769
 770         lock_buffer(bh);
 771         gfs2_log_lock(sdp);
 772         clear_buffer_dirty(bh);
 773         bd = bh->b_private;
 774         if (bd) {
 775                 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
 776                         list_del_init(&bd->bd_list);
 777                 else
 778                         gfs2_remove_from_journal(bh, REMOVE_JDATA);
 779         }
 780         bh->b_bdev = NULL;
 781         clear_buffer_mapped(bh);
 782         clear_buffer_req(bh);
 783         clear_buffer_new(bh);
 784         gfs2_log_unlock(sdp);
 785         unlock_buffer(bh);
 786 }
 787
 788 static void gfs2_invalidatepage(struct page *page, unsigned int offset,
 789                                 unsigned int length)
 790 {
 791         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
 792         unsigned int stop = offset + length;
 793         int partial_page = (offset || length < PAGE_SIZE);
 794         struct buffer_head *bh, *head;
 795         unsigned long pos = 0;
 796
 797         BUG_ON(!PageLocked(page));
 798         if (!partial_page)
 799                 ClearPageChecked(page);
 800         if (!page_has_buffers(page))
 801                 goto out;
 802
 803         bh = head = page_buffers(page);
 804         do {
 805                 if (pos + bh->b_size > stop)
 806                         return;
 807
 808                 if (offset <= pos)
 809                         gfs2_discard(sdp, bh);
 810                 pos += bh->b_size;
 811                 bh = bh->b_this_page;
 812         } while (bh != head);
 813 out:
 814         if (!partial_page)
 815                 try_to_release_page(page, 0);
 816 }
 817
 818 /**
 819  * gfs2_releasepage - free the metadata associated with a page
 820  * @page: the page that's being released
 821  * @gfp_mask: passed from Linux VFS, ignored by us
 822  *
 823  * Call try_to_free_buffers() if the buffers in this page can be
 824  * released.
 825  *
 826  * Returns: 0
 827  */
 828
 829 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
 830 {
 831         struct address_space *mapping = page->mapping;
 832         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 833         struct buffer_head *bh, *head;
 834         struct gfs2_bufdata *bd;
 835
 836         if (!page_has_buffers(page))
 837                 return 0;
 838
 839         /*
 840          * From xfs_vm_releasepage: mm accommodates an old ext3 case where
 841          * clean pages might not have had the dirty bit cleared.  Thus, it can
 842          * send actual dirty pages to ->releasepage() via shrink_active_list().
 843          *
 844          * As a workaround, we skip pages that contain dirty buffers below.
 845          * Once ->releasepage isn't called on dirty pages anymore, we can warn
 846          * on dirty buffers like we used to here again.
 847          */
 848
 849         gfs2_log_lock(sdp);
 850         spin_lock(&sdp->sd_ail_lock);
 851         head = bh = page_buffers(page);
 852         do {
 853                 if (atomic_read(&bh->b_count))
 854                         goto cannot_release;
 855                 bd = bh->b_private;
 856                 if (bd && bd->bd_tr)
 857                         goto cannot_release;
 858                 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
 859                         goto cannot_release;
 860                 bh = bh->b_this_page;
 861         } while(bh != head);
 862         spin_unlock(&sdp->sd_ail_lock);
 863
 864         head = bh = page_buffers(page);
 865         do {
 866                 bd = bh->b_private;
 867                 if (bd) {
 868                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
 869                         if (!list_empty(&bd->bd_list))
 870                                 list_del_init(&bd->bd_list);
 871                         bd->bd_bh = NULL;
 872                         bh->b_private = NULL;
 873                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 874                 }
 875
 876                 bh = bh->b_this_page;
 877         } while (bh != head);
 878         gfs2_log_unlock(sdp);
 879
 880         return try_to_free_buffers(page);
 881
 882 cannot_release:
 883         spin_unlock(&sdp->sd_ail_lock);
 884         gfs2_log_unlock(sdp);
 885         return 0;
 886 }
 887
 888 static const struct address_space_operations gfs2_writeback_aops = {
 889         .writepage = gfs2_writepage,
 890         .writepages = gfs2_writepages,
 891         .readpage = gfs2_readpage,
 892         .readpages = gfs2_readpages,
 893         .bmap = gfs2_bmap,
 894         .invalidatepage = gfs2_invalidatepage,
 895         .releasepage = gfs2_releasepage,
 896         .direct_IO = noop_direct_IO,
 897         .migratepage = buffer_migrate_page,
 898         .is_partially_uptodate = block_is_partially_uptodate,
 899         .error_remove_page = generic_error_remove_page,
 900 };
 901
 902 static const struct address_space_operations gfs2_ordered_aops = {
 903         .writepage = gfs2_writepage,
 904         .writepages = gfs2_writepages,
 905         .readpage = gfs2_readpage,
 906         .readpages = gfs2_readpages,
 907         .set_page_dirty = __set_page_dirty_buffers,
 908         .bmap = gfs2_bmap,
 909         .invalidatepage = gfs2_invalidatepage,
 910         .releasepage = gfs2_releasepage,
 911         .direct_IO = noop_direct_IO,
 912         .migratepage = buffer_migrate_page,
 913         .is_partially_uptodate = block_is_partially_uptodate,
 914         .error_remove_page = generic_error_remove_page,
 915 };
 916
 917 static const struct address_space_operations gfs2_jdata_aops = {
 918         .writepage = gfs2_jdata_writepage,
 919         .writepages = gfs2_jdata_writepages,
 920         .readpage = gfs2_readpage,
 921         .readpages = gfs2_readpages,
 922         .set_page_dirty = jdata_set_page_dirty,
 923         .bmap = gfs2_bmap,
 924         .invalidatepage = gfs2_invalidatepage,
 925         .releasepage = gfs2_releasepage,
 926         .is_partially_uptodate = block_is_partially_uptodate,
 927         .error_remove_page = generic_error_remove_page,
 928 };
 929
 930 void gfs2_set_aops(struct inode *inode)
 931 {
 932         struct gfs2_inode *ip = GFS2_I(inode);
 933
 934         if (gfs2_is_writeback(ip))
 935                 inode->i_mapping->a_ops = &gfs2_writeback_aops;
 936         else if (gfs2_is_ordered(ip))
 937                 inode->i_mapping->a_ops = &gfs2_ordered_aops;
 938         else if (gfs2_is_jdata(ip))
 939                 inode->i_mapping->a_ops = &gfs2_jdata_aops;
 940         else
 941                 BUG();
 942 }
 943