fs/gfs2/aops.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/buffer_head.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/pagevec.h>
  14 #include <linux/mpage.h>
  15 #include <linux/fs.h>
  16 #include <linux/writeback.h>
  17 #include <linux/swap.h>
  18 #include <linux/gfs2_ondisk.h>
  19 #include <linux/backing-dev.h>
  20 #include <linux/uio.h>
  21 #include <trace/events/writeback.h>
  22 #include <linux/sched/signal.h>
  23
  24 #include "gfs2.h"
  25 #include "incore.h"
  26 #include "bmap.h"
  27 #include "glock.h"
  28 #include "inode.h"
  29 #include "log.h"
  30 #include "meta_io.h"
  31 #include "quota.h"
  32 #include "trans.h"
  33 #include "rgrp.h"
  34 #include "super.h"
  35 #include "util.h"
  36 #include "glops.h"
  37 #include "aops.h"
  38
  39
  40 void gfs2_trans_add_databufs(struct gfs2_inode *ip, struct folio *folio,
  41                              size_t from, size_t len)
  42 {
  43         struct buffer_head *head = folio_buffers(folio);
  44         unsigned int bsize = head->b_size;
  45         struct buffer_head *bh;
  46         size_t to = from + len;
  47         size_t start, end;
  48
  49         for (bh = head, start = 0; bh != head || !start;
  50              bh = bh->b_this_page, start = end) {
  51                 end = start + bsize;
  52                 if (end <= from)
  53                         continue;
  54                 if (start >= to)
  55                         break;
  56                 set_buffer_uptodate(bh);
  57                 gfs2_trans_add_data(ip->i_gl, bh);
  58         }
  59 }
  60
  61 /**
  62  * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
  63  * @inode: The inode
  64  * @lblock: The block number to look up
  65  * @bh_result: The buffer head to return the result in
  66  * @create: Non-zero if we may add block to the file
  67  *
  68  * Returns: errno
  69  */
  70
  71 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
  72                                   struct buffer_head *bh_result, int create)
  73 {
  74         int error;
  75
  76         error = gfs2_block_map(inode, lblock, bh_result, 0);
  77         if (error)
  78                 return error;
  79         if (!buffer_mapped(bh_result))
  80                 return -ENODATA;
  81         return 0;
  82 }
  83
  84 /**
  85  * gfs2_write_jdata_folio - gfs2 jdata-specific version of block_write_full_page
  86  * @folio: The folio to write
  87  * @wbc: The writeback control
  88  *
  89  * This is the same as calling block_write_full_page, but it also
  90  * writes pages outside of i_size
  91  */
  92 static int gfs2_write_jdata_folio(struct folio *folio,
  93                                  struct writeback_control *wbc)
  94 {
  95         struct inode * const inode = folio->mapping->host;
  96         loff_t i_size = i_size_read(inode);
  97
  98         /*
  99          * The folio straddles i_size.  It must be zeroed out on each and every
 100          * writepage invocation because it may be mmapped.  "A file is mapped
 101          * in multiples of the page size.  For a file that is not a multiple of
 102          * the page size, the remaining memory is zeroed when mapped, and
 103          * writes to that region are not written out to the file."
 104          */
 105         if (folio_pos(folio) < i_size &&
 106             i_size < folio_pos(folio) + folio_size(folio))
 107                 folio_zero_segment(folio, offset_in_folio(folio, i_size),
 108                                 folio_size(folio));
 109
 110         return __block_write_full_folio(inode, folio, gfs2_get_block_noalloc,
 111                         wbc, end_buffer_async_write);
 112 }
 113
 114 /**
 115  * __gfs2_jdata_write_folio - The core of jdata writepage
 116  * @folio: The folio to write
 117  * @wbc: The writeback control
 118  *
 119  * This is shared between writepage and writepages and implements the
 120  * core of the writepage operation. If a transaction is required then
 121  * the checked flag will have been set and the transaction will have
 122  * already been started before this is called.
 123  */
 124 static int __gfs2_jdata_write_folio(struct folio *folio,
 125                 struct writeback_control *wbc)
 126 {
 127         struct inode *inode = folio->mapping->host;
 128         struct gfs2_inode *ip = GFS2_I(inode);
 129
 130         if (folio_test_checked(folio)) {
 131                 folio_clear_checked(folio);
 132                 if (!folio_buffers(folio)) {
 133                         folio_create_empty_buffers(folio,
 134                                         inode->i_sb->s_blocksize,
 135                                         BIT(BH_Dirty)|BIT(BH_Uptodate));
 136                 }
 137                 gfs2_trans_add_databufs(ip, folio, 0, folio_size(folio));
 138         }
 139         return gfs2_write_jdata_folio(folio, wbc);
 140 }
 141
 142 /**
 143  * gfs2_jdata_writepage - Write complete page
 144  * @page: Page to write
 145  * @wbc: The writeback control
 146  *
 147  * Returns: errno
 148  *
 149  */
 150
 151 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
 152 {
 153         struct folio *folio = page_folio(page);
 154         struct inode *inode = page->mapping->host;
 155         struct gfs2_inode *ip = GFS2_I(inode);
 156         struct gfs2_sbd *sdp = GFS2_SB(inode);
 157
 158         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
 159                 goto out;
 160         if (folio_test_checked(folio) || current->journal_info)
 161                 goto out_ignore;
 162         return __gfs2_jdata_write_folio(folio, wbc);
 163
 164 out_ignore:
 165         folio_redirty_for_writepage(wbc, folio);
 166 out:
 167         folio_unlock(folio);
 168         return 0;
 169 }
 170
 171 /**
 172  * gfs2_writepages - Write a bunch of dirty pages back to disk
 173  * @mapping: The mapping to write
 174  * @wbc: Write-back control
 175  *
 176  * Used for both ordered and writeback modes.
 177  */
 178 static int gfs2_writepages(struct address_space *mapping,
 179                            struct writeback_control *wbc)
 180 {
 181         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 182         struct iomap_writepage_ctx wpc = { };
 183         int ret;
 184
 185         /*
 186          * Even if we didn't write enough pages here, we might still be holding
 187          * dirty pages in the ail. We forcibly flush the ail because we don't
 188          * want balance_dirty_pages() to loop indefinitely trying to write out
 189          * pages held in the ail that it can't find.
 190          */
 191         ret = iomap_writepages(mapping, wbc, &wpc, &gfs2_writeback_ops);
 192         if (ret == 0 && wbc->nr_to_write > 0)
 193                 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
 194         return ret;
 195 }
 196
 197 /**
 198  * gfs2_write_jdata_batch - Write back a folio batch's worth of folios
 199  * @mapping: The mapping
 200  * @wbc: The writeback control
 201  * @fbatch: The batch of folios
 202  * @done_index: Page index
 203  *
 204  * Returns: non-zero if loop should terminate, zero otherwise
 205  */
 206
 207 static int gfs2_write_jdata_batch(struct address_space *mapping,
 208                                     struct writeback_control *wbc,
 209                                     struct folio_batch *fbatch,
 210                                     pgoff_t *done_index)
 211 {
 212         struct inode *inode = mapping->host;
 213         struct gfs2_sbd *sdp = GFS2_SB(inode);
 214         unsigned nrblocks;
 215         int i;
 216         int ret;
 217         int nr_pages = 0;
 218         int nr_folios = folio_batch_count(fbatch);
 219
 220         for (i = 0; i < nr_folios; i++)
 221                 nr_pages += folio_nr_pages(fbatch->folios[i]);
 222         nrblocks = nr_pages * (PAGE_SIZE >> inode->i_blkbits);
 223
 224         ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
 225         if (ret < 0)
 226                 return ret;
 227
 228         for (i = 0; i < nr_folios; i++) {
 229                 struct folio *folio = fbatch->folios[i];
 230
 231                 *done_index = folio->index;
 232
 233                 folio_lock(folio);
 234
 235                 if (unlikely(folio->mapping != mapping)) {
 236 continue_unlock:
 237                         folio_unlock(folio);
 238                         continue;
 239                 }
 240
 241                 if (!folio_test_dirty(folio)) {
 242                         /* someone wrote it for us */
 243                         goto continue_unlock;
 244                 }
 245
 246                 if (folio_test_writeback(folio)) {
 247                         if (wbc->sync_mode != WB_SYNC_NONE)
 248                                 folio_wait_writeback(folio);
 249                         else
 250                                 goto continue_unlock;
 251                 }
 252
 253                 BUG_ON(folio_test_writeback(folio));
 254                 if (!folio_clear_dirty_for_io(folio))
 255                         goto continue_unlock;
 256
 257                 trace_wbc_writepage(wbc, inode_to_bdi(inode));
 258
 259                 ret = __gfs2_jdata_write_folio(folio, wbc);
 260                 if (unlikely(ret)) {
 261                         if (ret == AOP_WRITEPAGE_ACTIVATE) {
 262                                 folio_unlock(folio);
 263                                 ret = 0;
 264                         } else {
 265
 266                                 /*
 267                                  * done_index is set past this page,
 268                                  * so media errors will not choke
 269                                  * background writeout for the entire
 270                                  * file. This has consequences for
 271                                  * range_cyclic semantics (ie. it may
 272                                  * not be suitable for data integrity
 273                                  * writeout).
 274                                  */
 275                                 *done_index = folio_next_index(folio);
 276                                 ret = 1;
 277                                 break;
 278                         }
 279                 }
 280
 281                 /*
 282                  * We stop writing back only if we are not doing
 283                  * integrity sync. In case of integrity sync we have to
 284                  * keep going until we have written all the pages
 285                  * we tagged for writeback prior to entering this loop.
 286                  */
 287                 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
 288                         ret = 1;
 289                         break;
 290                 }
 291
 292         }
 293         gfs2_trans_end(sdp);
 294         return ret;
 295 }
 296
 297 /**
 298  * gfs2_write_cache_jdata - Like write_cache_pages but different
 299  * @mapping: The mapping to write
 300  * @wbc: The writeback control
 301  *
 302  * The reason that we use our own function here is that we need to
 303  * start transactions before we grab page locks. This allows us
 304  * to get the ordering right.
 305  */
 306
 307 static int gfs2_write_cache_jdata(struct address_space *mapping,
 308                                   struct writeback_control *wbc)
 309 {
 310         int ret = 0;
 311         int done = 0;
 312         struct folio_batch fbatch;
 313         int nr_folios;
 314         pgoff_t writeback_index;
 315         pgoff_t index;
 316         pgoff_t end;
 317         pgoff_t done_index;
 318         int cycled;
 319         int range_whole = 0;
 320         xa_mark_t tag;
 321
 322         folio_batch_init(&fbatch);
 323         if (wbc->range_cyclic) {
 324                 writeback_index = mapping->writeback_index; /* prev offset */
 325                 index = writeback_index;
 326                 if (index == 0)
 327                         cycled = 1;
 328                 else
 329                         cycled = 0;
 330                 end = -1;
 331         } else {
 332                 index = wbc->range_start >> PAGE_SHIFT;
 333                 end = wbc->range_end >> PAGE_SHIFT;
 334                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 335                         range_whole = 1;
 336                 cycled = 1; /* ignore range_cyclic tests */
 337         }
 338         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 339                 tag = PAGECACHE_TAG_TOWRITE;
 340         else
 341                 tag = PAGECACHE_TAG_DIRTY;
 342
 343 retry:
 344         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 345                 tag_pages_for_writeback(mapping, index, end);
 346         done_index = index;
 347         while (!done && (index <= end)) {
 348                 nr_folios = filemap_get_folios_tag(mapping, &index, end,
 349                                 tag, &fbatch);
 350                 if (nr_folios == 0)
 351                         break;
 352
 353                 ret = gfs2_write_jdata_batch(mapping, wbc, &fbatch,
 354                                 &done_index);
 355                 if (ret)
 356                         done = 1;
 357                 if (ret > 0)
 358                         ret = 0;
 359                 folio_batch_release(&fbatch);
 360                 cond_resched();
 361         }
 362
 363         if (!cycled && !done) {
 364                 /*
 365                  * range_cyclic:
 366                  * We hit the last page and there is more work to be done: wrap
 367                  * back to the start of the file
 368                  */
 369                 cycled = 1;
 370                 index = 0;
 371                 end = writeback_index - 1;
 372                 goto retry;
 373         }
 374
 375         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
 376                 mapping->writeback_index = done_index;
 377
 378         return ret;
 379 }
 380
 381
 382 /**
 383  * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
 384  * @mapping: The mapping to write
 385  * @wbc: The writeback control
 386  *
 387  */
 388
 389 static int gfs2_jdata_writepages(struct address_space *mapping,
 390                                  struct writeback_control *wbc)
 391 {
 392         struct gfs2_inode *ip = GFS2_I(mapping->host);
 393         struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
 394         int ret;
 395
 396         ret = gfs2_write_cache_jdata(mapping, wbc);
 397         if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
 398                 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
 399                                GFS2_LFC_JDATA_WPAGES);
 400                 ret = gfs2_write_cache_jdata(mapping, wbc);
 401         }
 402         return ret;
 403 }
 404
 405 /**
 406  * stuffed_readpage - Fill in a Linux page with stuffed file data
 407  * @ip: the inode
 408  * @page: the page
 409  *
 410  * Returns: errno
 411  */
 412 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 413 {
 414         struct buffer_head *dibh;
 415         u64 dsize = i_size_read(&ip->i_inode);
 416         void *kaddr;
 417         int error;
 418
 419         /*
 420          * Due to the order of unstuffing files and ->fault(), we can be
 421          * asked for a zero page in the case of a stuffed file being extended,
 422          * so we need to supply one here. It doesn't happen often.
 423          */
 424         if (unlikely(page->index)) {
 425                 zero_user(page, 0, PAGE_SIZE);
 426                 SetPageUptodate(page);
 427                 return 0;
 428         }
 429
 430         error = gfs2_meta_inode_buffer(ip, &dibh);
 431         if (error)
 432                 return error;
 433
 434         kaddr = kmap_local_page(page);
 435         memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
 436         memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
 437         kunmap_local(kaddr);
 438         flush_dcache_page(page);
 439         brelse(dibh);
 440         SetPageUptodate(page);
 441
 442         return 0;
 443 }
 444
 445 /**
 446  * gfs2_read_folio - read a folio from a file
 447  * @file: The file to read
 448  * @folio: The folio in the file
 449  */
 450 static int gfs2_read_folio(struct file *file, struct folio *folio)
 451 {
 452         struct inode *inode = folio->mapping->host;
 453         struct gfs2_inode *ip = GFS2_I(inode);
 454         struct gfs2_sbd *sdp = GFS2_SB(inode);
 455         int error;
 456
 457         if (!gfs2_is_jdata(ip) ||
 458             (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
 459                 error = iomap_read_folio(folio, &gfs2_iomap_ops);
 460         } else if (gfs2_is_stuffed(ip)) {
 461                 error = stuffed_readpage(ip, &folio->page);
 462                 folio_unlock(folio);
 463         } else {
 464                 error = mpage_read_folio(folio, gfs2_block_map);
 465         }
 466
 467         if (unlikely(gfs2_withdrawn(sdp)))
 468                 return -EIO;
 469
 470         return error;
 471 }
 472
 473 /**
 474  * gfs2_internal_read - read an internal file
 475  * @ip: The gfs2 inode
 476  * @buf: The buffer to fill
 477  * @pos: The file position
 478  * @size: The amount to read
 479  *
 480  */
 481
 482 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
 483                        unsigned size)
 484 {
 485         struct address_space *mapping = ip->i_inode.i_mapping;
 486         unsigned long index = *pos >> PAGE_SHIFT;
 487         unsigned offset = *pos & (PAGE_SIZE - 1);
 488         unsigned copied = 0;
 489         unsigned amt;
 490         struct page *page;
 491
 492         do {
 493                 page = read_cache_page(mapping, index, gfs2_read_folio, NULL);
 494                 if (IS_ERR(page)) {
 495                         if (PTR_ERR(page) == -EINTR)
 496                                 continue;
 497                         return PTR_ERR(page);
 498                 }
 499                 amt = size - copied;
 500                 if (offset + size > PAGE_SIZE)
 501                         amt = PAGE_SIZE - offset;
 502                 memcpy_from_page(buf + copied, page, offset, amt);
 503                 put_page(page);
 504                 copied += amt;
 505                 index++;
 506                 offset = 0;
 507         } while(copied < size);
 508         (*pos) += size;
 509         return size;
 510 }
 511
 512 /**
 513  * gfs2_readahead - Read a bunch of pages at once
 514  * @rac: Read-ahead control structure
 515  *
 516  * Some notes:
 517  * 1. This is only for readahead, so we can simply ignore any things
 518  *    which are slightly inconvenient (such as locking conflicts between
 519  *    the page lock and the glock) and return having done no I/O. Its
 520  *    obviously not something we'd want to do on too regular a basis.
 521  *    Any I/O we ignore at this time will be done via readpage later.
 522  * 2. We don't handle stuffed files here we let readpage do the honours.
 523  * 3. mpage_readahead() does most of the heavy lifting in the common case.
 524  * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
 525  */
 526
 527 static void gfs2_readahead(struct readahead_control *rac)
 528 {
 529         struct inode *inode = rac->mapping->host;
 530         struct gfs2_inode *ip = GFS2_I(inode);
 531
 532         if (gfs2_is_stuffed(ip))
 533                 ;
 534         else if (gfs2_is_jdata(ip))
 535                 mpage_readahead(rac, gfs2_block_map);
 536         else
 537                 iomap_readahead(rac, &gfs2_iomap_ops);
 538 }
 539
 540 /**
 541  * adjust_fs_space - Adjusts the free space available due to gfs2_grow
 542  * @inode: the rindex inode
 543  */
 544 void adjust_fs_space(struct inode *inode)
 545 {
 546         struct gfs2_sbd *sdp = GFS2_SB(inode);
 547         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 548         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 549         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 550         struct buffer_head *m_bh;
 551         u64 fs_total, new_free;
 552
 553         if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0)
 554                 return;
 555
 556         /* Total up the file system space, according to the latest rindex. */
 557         fs_total = gfs2_ri_total(sdp);
 558         if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
 559                 goto out;
 560
 561         spin_lock(&sdp->sd_statfs_spin);
 562         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 563                               sizeof(struct gfs2_dinode));
 564         if (fs_total > (m_sc->sc_total + l_sc->sc_total))
 565                 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
 566         else
 567                 new_free = 0;
 568         spin_unlock(&sdp->sd_statfs_spin);
 569         fs_warn(sdp, "File system extended by %llu blocks.\n",
 570                 (unsigned long long)new_free);
 571         gfs2_statfs_change(sdp, new_free, new_free, 0);
 572
 573         update_statfs(sdp, m_bh);
 574         brelse(m_bh);
 575 out:
 576         sdp->sd_rindex_uptodate = 0;
 577         gfs2_trans_end(sdp);
 578 }
 579
 580 static bool jdata_dirty_folio(struct address_space *mapping,
 581                 struct folio *folio)
 582 {
 583         if (current->journal_info)
 584                 folio_set_checked(folio);
 585         return block_dirty_folio(mapping, folio);
 586 }
 587
 588 /**
 589  * gfs2_bmap - Block map function
 590  * @mapping: Address space info
 591  * @lblock: The block to map
 592  *
 593  * Returns: The disk address for the block or 0 on hole or error
 594  */
 595
 596 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
 597 {
 598         struct gfs2_inode *ip = GFS2_I(mapping->host);
 599         struct gfs2_holder i_gh;
 600         sector_t dblock = 0;
 601         int error;
 602
 603         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 604         if (error)
 605                 return 0;
 606
 607         if (!gfs2_is_stuffed(ip))
 608                 dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops);
 609
 610         gfs2_glock_dq_uninit(&i_gh);
 611
 612         return dblock;
 613 }
 614
 615 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
 616 {
 617         struct gfs2_bufdata *bd;
 618
 619         lock_buffer(bh);
 620         gfs2_log_lock(sdp);
 621         clear_buffer_dirty(bh);
 622         bd = bh->b_private;
 623         if (bd) {
 624                 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
 625                         list_del_init(&bd->bd_list);
 626                 else {
 627                         spin_lock(&sdp->sd_ail_lock);
 628                         gfs2_remove_from_journal(bh, REMOVE_JDATA);
 629                         spin_unlock(&sdp->sd_ail_lock);
 630                 }
 631         }
 632         bh->b_bdev = NULL;
 633         clear_buffer_mapped(bh);
 634         clear_buffer_req(bh);
 635         clear_buffer_new(bh);
 636         gfs2_log_unlock(sdp);
 637         unlock_buffer(bh);
 638 }
 639
 640 static void gfs2_invalidate_folio(struct folio *folio, size_t offset,
 641                                 size_t length)
 642 {
 643         struct gfs2_sbd *sdp = GFS2_SB(folio->mapping->host);
 644         size_t stop = offset + length;
 645         int partial_page = (offset || length < folio_size(folio));
 646         struct buffer_head *bh, *head;
 647         unsigned long pos = 0;
 648
 649         BUG_ON(!folio_test_locked(folio));
 650         if (!partial_page)
 651                 folio_clear_checked(folio);
 652         head = folio_buffers(folio);
 653         if (!head)
 654                 goto out;
 655
 656         bh = head;
 657         do {
 658                 if (pos + bh->b_size > stop)
 659                         return;
 660
 661                 if (offset <= pos)
 662                         gfs2_discard(sdp, bh);
 663                 pos += bh->b_size;
 664                 bh = bh->b_this_page;
 665         } while (bh != head);
 666 out:
 667         if (!partial_page)
 668                 filemap_release_folio(folio, 0);
 669 }
 670
 671 /**
 672  * gfs2_release_folio - free the metadata associated with a folio
 673  * @folio: the folio that's being released
 674  * @gfp_mask: passed from Linux VFS, ignored by us
 675  *
 676  * Calls try_to_free_buffers() to free the buffers and put the folio if the
 677  * buffers can be released.
 678  *
 679  * Returns: true if the folio was put or else false
 680  */
 681
 682 bool gfs2_release_folio(struct folio *folio, gfp_t gfp_mask)
 683 {
 684         struct address_space *mapping = folio->mapping;
 685         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 686         struct buffer_head *bh, *head;
 687         struct gfs2_bufdata *bd;
 688
 689         head = folio_buffers(folio);
 690         if (!head)
 691                 return false;
 692
 693         /*
 694          * mm accommodates an old ext3 case where clean folios might
 695          * not have had the dirty bit cleared.  Thus, it can send actual
 696          * dirty folios to ->release_folio() via shrink_active_list().
 697          *
 698          * As a workaround, we skip folios that contain dirty buffers
 699          * below.  Once ->release_folio isn't called on dirty folios
 700          * anymore, we can warn on dirty buffers like we used to here
 701          * again.
 702          */
 703
 704         gfs2_log_lock(sdp);
 705         bh = head;
 706         do {
 707                 if (atomic_read(&bh->b_count))
 708                         goto cannot_release;
 709                 bd = bh->b_private;
 710                 if (bd && bd->bd_tr)
 711                         goto cannot_release;
 712                 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
 713                         goto cannot_release;
 714                 bh = bh->b_this_page;
 715         } while (bh != head);
 716
 717         bh = head;
 718         do {
 719                 bd = bh->b_private;
 720                 if (bd) {
 721                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
 722                         bd->bd_bh = NULL;
 723                         bh->b_private = NULL;
 724                         /*
 725                          * The bd may still be queued as a revoke, in which
 726                          * case we must not dequeue nor free it.
 727                          */
 728                         if (!bd->bd_blkno && !list_empty(&bd->bd_list))
 729                                 list_del_init(&bd->bd_list);
 730                         if (list_empty(&bd->bd_list))
 731                                 kmem_cache_free(gfs2_bufdata_cachep, bd);
 732                 }
 733
 734                 bh = bh->b_this_page;
 735         } while (bh != head);
 736         gfs2_log_unlock(sdp);
 737
 738         return try_to_free_buffers(folio);
 739
 740 cannot_release:
 741         gfs2_log_unlock(sdp);
 742         return false;
 743 }
 744
 745 static const struct address_space_operations gfs2_aops = {
 746         .writepages = gfs2_writepages,
 747         .read_folio = gfs2_read_folio,
 748         .readahead = gfs2_readahead,
 749         .dirty_folio = iomap_dirty_folio,
 750         .release_folio = iomap_release_folio,
 751         .invalidate_folio = iomap_invalidate_folio,
 752         .bmap = gfs2_bmap,
 753         .migrate_folio = filemap_migrate_folio,
 754         .is_partially_uptodate = iomap_is_partially_uptodate,
 755         .error_remove_page = generic_error_remove_page,
 756 };
 757
 758 static const struct address_space_operations gfs2_jdata_aops = {
 759         .writepage = gfs2_jdata_writepage,
 760         .writepages = gfs2_jdata_writepages,
 761         .read_folio = gfs2_read_folio,
 762         .readahead = gfs2_readahead,
 763         .dirty_folio = jdata_dirty_folio,
 764         .bmap = gfs2_bmap,
 765         .invalidate_folio = gfs2_invalidate_folio,
 766         .release_folio = gfs2_release_folio,
 767         .is_partially_uptodate = block_is_partially_uptodate,
 768         .error_remove_page = generic_error_remove_page,
 769 };
 770
 771 void gfs2_set_aops(struct inode *inode)
 772 {
 773         if (gfs2_is_jdata(GFS2_I(inode)))
 774                 inode->i_mapping->a_ops = &gfs2_jdata_aops;
 775         else
 776                 inode->i_mapping->a_ops = &gfs2_aops;
 777 }