fs/gfs2/meta_io.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/mm.h>
  13 #include <linux/pagemap.h>
  14 #include <linux/writeback.h>
  15 #include <linux/swap.h>
  16 #include <linux/delay.h>
  17 #include <linux/bio.h>
  18 #include <linux/gfs2_ondisk.h>
  19
  20 #include "gfs2.h"
  21 #include "incore.h"
  22 #include "glock.h"
  23 #include "glops.h"
  24 #include "inode.h"
  25 #include "log.h"
  26 #include "lops.h"
  27 #include "meta_io.h"
  28 #include "rgrp.h"
  29 #include "trans.h"
  30 #include "util.h"
  31 #include "trace_gfs2.h"
  32
  33 static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
  34 {
  35         struct buffer_head *bh, *head;
  36         int nr_underway = 0;
  37         blk_opf_t write_flags = REQ_META | REQ_PRIO | wbc_to_write_flags(wbc);
  38
  39         BUG_ON(!PageLocked(page));
  40         BUG_ON(!page_has_buffers(page));
  41
  42         head = page_buffers(page);
  43         bh = head;
  44
  45         do {
  46                 if (!buffer_mapped(bh))
  47                         continue;
  48                 /*
  49                  * If it's a fully non-blocking write attempt and we cannot
  50                  * lock the buffer then redirty the page.  Note that this can
  51                  * potentially cause a busy-wait loop from flusher thread and kswapd
  52                  * activity, but those code paths have their own higher-level
  53                  * throttling.
  54                  */
  55                 if (wbc->sync_mode != WB_SYNC_NONE) {
  56                         lock_buffer(bh);
  57                 } else if (!trylock_buffer(bh)) {
  58                         redirty_page_for_writepage(wbc, page);
  59                         continue;
  60                 }
  61                 if (test_clear_buffer_dirty(bh)) {
  62                         mark_buffer_async_write(bh);
  63                 } else {
  64                         unlock_buffer(bh);
  65                 }
  66         } while ((bh = bh->b_this_page) != head);
  67
  68         /*
  69          * The page and its buffers are protected by PageWriteback(), so we can
  70          * drop the bh refcounts early.
  71          */
  72         BUG_ON(PageWriteback(page));
  73         set_page_writeback(page);
  74
  75         do {
  76                 struct buffer_head *next = bh->b_this_page;
  77                 if (buffer_async_write(bh)) {
  78                         submit_bh(REQ_OP_WRITE | write_flags, bh);
  79                         nr_underway++;
  80                 }
  81                 bh = next;
  82         } while (bh != head);
  83         unlock_page(page);
  84
  85         if (nr_underway == 0)
  86                 end_page_writeback(page);
  87
  88         return 0;
  89 }
  90
  91 const struct address_space_operations gfs2_meta_aops = {
  92         .dirty_folio    = block_dirty_folio,
  93         .invalidate_folio = block_invalidate_folio,
  94         .writepage = gfs2_aspace_writepage,
  95         .release_folio = gfs2_release_folio,
  96 };
  97
  98 const struct address_space_operations gfs2_rgrp_aops = {
  99         .dirty_folio    = block_dirty_folio,
 100         .invalidate_folio = block_invalidate_folio,
 101         .writepage = gfs2_aspace_writepage,
 102         .release_folio = gfs2_release_folio,
 103 };
 104
 105 /**
 106  * gfs2_getbuf - Get a buffer with a given address space
 107  * @gl: the glock
 108  * @blkno: the block number (filesystem scope)
 109  * @create: 1 if the buffer should be created
 110  *
 111  * Returns: the buffer
 112  */
 113
 114 struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
 115 {
 116         struct address_space *mapping = gfs2_glock2aspace(gl);
 117         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 118         struct folio *folio;
 119         struct buffer_head *bh;
 120         unsigned int shift;
 121         unsigned long index;
 122         unsigned int bufnum;
 123
 124         if (mapping == NULL)
 125                 mapping = &sdp->sd_aspace;
 126
 127         shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 128         index = blkno >> shift;             /* convert block to page */
 129         bufnum = blkno - (index << shift);  /* block buf index within page */
 130
 131         if (create) {
 132                 folio = __filemap_get_folio(mapping, index,
 133                                 FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
 134                                 mapping_gfp_mask(mapping) | __GFP_NOFAIL);
 135                 bh = folio_buffers(folio);
 136                 if (!bh)
 137                         bh = create_empty_buffers(folio,
 138                                 sdp->sd_sb.sb_bsize, 0);
 139         } else {
 140                 folio = __filemap_get_folio(mapping, index,
 141                                 FGP_LOCK | FGP_ACCESSED, 0);
 142                 if (IS_ERR(folio))
 143                         return NULL;
 144                 bh = folio_buffers(folio);
 145         }
 146
 147         if (!bh)
 148                 goto out_unlock;
 149
 150         bh = get_nth_bh(bh, bufnum);
 151         if (!buffer_mapped(bh))
 152                 map_bh(bh, sdp->sd_vfs, blkno);
 153
 154 out_unlock:
 155         folio_unlock(folio);
 156         folio_put(folio);
 157
 158         return bh;
 159 }
 160
 161 static void meta_prep_new(struct buffer_head *bh)
 162 {
 163         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 164
 165         lock_buffer(bh);
 166         clear_buffer_dirty(bh);
 167         set_buffer_uptodate(bh);
 168         unlock_buffer(bh);
 169
 170         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 171 }
 172
 173 /**
 174  * gfs2_meta_new - Get a block
 175  * @gl: The glock associated with this block
 176  * @blkno: The block number
 177  *
 178  * Returns: The buffer
 179  */
 180
 181 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 182 {
 183         struct buffer_head *bh;
 184         bh = gfs2_getbuf(gl, blkno, CREATE);
 185         meta_prep_new(bh);
 186         return bh;
 187 }
 188
 189 static void gfs2_meta_read_endio(struct bio *bio)
 190 {
 191         struct bio_vec *bvec;
 192         struct bvec_iter_all iter_all;
 193
 194         bio_for_each_segment_all(bvec, bio, iter_all) {
 195                 struct page *page = bvec->bv_page;
 196                 struct buffer_head *bh = page_buffers(page);
 197                 unsigned int len = bvec->bv_len;
 198
 199                 while (bh_offset(bh) < bvec->bv_offset)
 200                         bh = bh->b_this_page;
 201                 do {
 202                         struct buffer_head *next = bh->b_this_page;
 203                         len -= bh->b_size;
 204                         bh->b_end_io(bh, !bio->bi_status);
 205                         bh = next;
 206                 } while (bh && len);
 207         }
 208         bio_put(bio);
 209 }
 210
 211 /*
 212  * Submit several consecutive buffer head I/O requests as a single bio I/O
 213  * request.  (See submit_bh_wbc.)
 214  */
 215 static void gfs2_submit_bhs(blk_opf_t opf, struct buffer_head *bhs[], int num)
 216 {
 217         while (num > 0) {
 218                 struct buffer_head *bh = *bhs;
 219                 struct bio *bio;
 220
 221                 bio = bio_alloc(bh->b_bdev, num, opf, GFP_NOIO);
 222                 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 223                 while (num > 0) {
 224                         bh = *bhs;
 225                         if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
 226                                 BUG_ON(bio->bi_iter.bi_size == 0);
 227                                 break;
 228                         }
 229                         bhs++;
 230                         num--;
 231                 }
 232                 bio->bi_end_io = gfs2_meta_read_endio;
 233                 submit_bio(bio);
 234         }
 235 }
 236
 237 /**
 238  * gfs2_meta_read - Read a block from disk
 239  * @gl: The glock covering the block
 240  * @blkno: The block number
 241  * @flags: flags
 242  * @rahead: Do read-ahead
 243  * @bhp: the place where the buffer is returned (NULL on failure)
 244  *
 245  * Returns: errno
 246  */
 247
 248 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 249                    int rahead, struct buffer_head **bhp)
 250 {
 251         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 252         struct buffer_head *bh, *bhs[2];
 253         int num = 0;
 254
 255         if (gfs2_withdrawing_or_withdrawn(sdp) &&
 256             !gfs2_withdraw_in_prog(sdp)) {
 257                 *bhp = NULL;
 258                 return -EIO;
 259         }
 260
 261         *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
 262
 263         lock_buffer(bh);
 264         if (buffer_uptodate(bh)) {
 265                 unlock_buffer(bh);
 266                 flags &= ~DIO_WAIT;
 267         } else {
 268                 bh->b_end_io = end_buffer_read_sync;
 269                 get_bh(bh);
 270                 bhs[num++] = bh;
 271         }
 272
 273         if (rahead) {
 274                 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
 275
 276                 lock_buffer(bh);
 277                 if (buffer_uptodate(bh)) {
 278                         unlock_buffer(bh);
 279                         brelse(bh);
 280                 } else {
 281                         bh->b_end_io = end_buffer_read_sync;
 282                         bhs[num++] = bh;
 283                 }
 284         }
 285
 286         gfs2_submit_bhs(REQ_OP_READ | REQ_META | REQ_PRIO, bhs, num);
 287         if (!(flags & DIO_WAIT))
 288                 return 0;
 289
 290         bh = *bhp;
 291         wait_on_buffer(bh);
 292         if (unlikely(!buffer_uptodate(bh))) {
 293                 struct gfs2_trans *tr = current->journal_info;
 294                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 295                         gfs2_io_error_bh_wd(sdp, bh);
 296                 brelse(bh);
 297                 *bhp = NULL;
 298                 return -EIO;
 299         }
 300
 301         return 0;
 302 }
 303
 304 /**
 305  * gfs2_meta_wait - Reread a block from disk
 306  * @sdp: the filesystem
 307  * @bh: The block to wait for
 308  *
 309  * Returns: errno
 310  */
 311
 312 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
 313 {
 314         if (gfs2_withdrawing_or_withdrawn(sdp) &&
 315             !gfs2_withdraw_in_prog(sdp))
 316                 return -EIO;
 317
 318         wait_on_buffer(bh);
 319
 320         if (!buffer_uptodate(bh)) {
 321                 struct gfs2_trans *tr = current->journal_info;
 322                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 323                         gfs2_io_error_bh_wd(sdp, bh);
 324                 return -EIO;
 325         }
 326         if (gfs2_withdrawing_or_withdrawn(sdp) &&
 327             !gfs2_withdraw_in_prog(sdp))
 328                 return -EIO;
 329
 330         return 0;
 331 }
 332
 333 void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
 334 {
 335         struct address_space *mapping = bh->b_folio->mapping;
 336         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 337         struct gfs2_bufdata *bd = bh->b_private;
 338         struct gfs2_trans *tr = current->journal_info;
 339         int was_pinned = 0;
 340
 341         if (test_clear_buffer_pinned(bh)) {
 342                 trace_gfs2_pin(bd, 0);
 343                 atomic_dec(&sdp->sd_log_pinned);
 344                 list_del_init(&bd->bd_list);
 345                 if (meta == REMOVE_META)
 346                         tr->tr_num_buf_rm++;
 347                 else
 348                         tr->tr_num_databuf_rm++;
 349                 set_bit(TR_TOUCHED, &tr->tr_flags);
 350                 was_pinned = 1;
 351                 brelse(bh);
 352         }
 353         if (bd) {
 354                 if (bd->bd_tr) {
 355                         gfs2_trans_add_revoke(sdp, bd);
 356                 } else if (was_pinned) {
 357                         bh->b_private = NULL;
 358                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 359                 } else if (!list_empty(&bd->bd_ail_st_list) &&
 360                                         !list_empty(&bd->bd_ail_gl_list)) {
 361                         gfs2_remove_from_ail(bd);
 362                 }
 363         }
 364         clear_buffer_dirty(bh);
 365         clear_buffer_uptodate(bh);
 366 }
 367
 368 /**
 369  * gfs2_ail1_wipe - remove deleted/freed buffers from the ail1 list
 370  * @sdp: superblock
 371  * @bstart: starting block address of buffers to remove
 372  * @blen: length of buffers to be removed
 373  *
 374  * This function is called from gfs2_journal wipe, whose job is to remove
 375  * buffers, corresponding to deleted blocks, from the journal. If we find any
 376  * bufdata elements on the system ail1 list, they haven't been written to
 377  * the journal yet. So we remove them.
 378  */
 379 static void gfs2_ail1_wipe(struct gfs2_sbd *sdp, u64 bstart, u32 blen)
 380 {
 381         struct gfs2_trans *tr, *s;
 382         struct gfs2_bufdata *bd, *bs;
 383         struct buffer_head *bh;
 384         u64 end = bstart + blen;
 385
 386         gfs2_log_lock(sdp);
 387         spin_lock(&sdp->sd_ail_lock);
 388         list_for_each_entry_safe(tr, s, &sdp->sd_ail1_list, tr_list) {
 389                 list_for_each_entry_safe(bd, bs, &tr->tr_ail1_list,
 390                                          bd_ail_st_list) {
 391                         bh = bd->bd_bh;
 392                         if (bh->b_blocknr < bstart || bh->b_blocknr >= end)
 393                                 continue;
 394
 395                         gfs2_remove_from_journal(bh, REMOVE_JDATA);
 396                 }
 397         }
 398         spin_unlock(&sdp->sd_ail_lock);
 399         gfs2_log_unlock(sdp);
 400 }
 401
 402 static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
 403 {
 404         struct address_space *mapping = ip->i_inode.i_mapping;
 405         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 406         struct folio *folio;
 407         struct buffer_head *bh;
 408         unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 409         unsigned long index = blkno >> shift; /* convert block to page */
 410         unsigned int bufnum = blkno - (index << shift);
 411
 412         folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCESSED, 0);
 413         if (IS_ERR(folio))
 414                 return NULL;
 415         bh = folio_buffers(folio);
 416         if (bh)
 417                 bh = get_nth_bh(bh, bufnum);
 418         folio_unlock(folio);
 419         folio_put(folio);
 420         return bh;
 421 }
 422
 423 /**
 424  * gfs2_journal_wipe - make inode's buffers so they aren't dirty/pinned anymore
 425  * @ip: the inode who owns the buffers
 426  * @bstart: the first buffer in the run
 427  * @blen: the number of buffers in the run
 428  *
 429  */
 430
 431 void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
 432 {
 433         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 434         struct buffer_head *bh;
 435         int ty;
 436
 437         if (!ip->i_gl) {
 438                 /* This can only happen during incomplete inode creation. */
 439                 BUG_ON(!test_bit(GIF_ALLOC_FAILED, &ip->i_flags));
 440                 return;
 441         }
 442
 443         gfs2_ail1_wipe(sdp, bstart, blen);
 444         while (blen) {
 445                 ty = REMOVE_META;
 446                 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
 447                 if (!bh && gfs2_is_jdata(ip)) {
 448                         bh = gfs2_getjdatabuf(ip, bstart);
 449                         ty = REMOVE_JDATA;
 450                 }
 451                 if (bh) {
 452                         lock_buffer(bh);
 453                         gfs2_log_lock(sdp);
 454                         spin_lock(&sdp->sd_ail_lock);
 455                         gfs2_remove_from_journal(bh, ty);
 456                         spin_unlock(&sdp->sd_ail_lock);
 457                         gfs2_log_unlock(sdp);
 458                         unlock_buffer(bh);
 459                         brelse(bh);
 460                 }
 461
 462                 bstart++;
 463                 blen--;
 464         }
 465 }
 466
 467 /**
 468  * gfs2_meta_buffer - Get a metadata buffer
 469  * @ip: The GFS2 inode
 470  * @mtype: The block type (GFS2_METATYPE_*)
 471  * @num: The block number (device relative) of the buffer
 472  * @bhp: the buffer is returned here
 473  *
 474  * Returns: errno
 475  */
 476
 477 int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num,
 478                      struct buffer_head **bhp)
 479 {
 480         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 481         struct gfs2_glock *gl = ip->i_gl;
 482         struct buffer_head *bh;
 483         int ret = 0;
 484         int rahead = 0;
 485
 486         if (num == ip->i_no_addr)
 487                 rahead = ip->i_rahead;
 488
 489         ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
 490         if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
 491                 brelse(bh);
 492                 ret = -EIO;
 493         } else {
 494                 *bhp = bh;
 495         }
 496         return ret;
 497 }
 498
 499 /**
 500  * gfs2_meta_ra - start readahead on an extent of a file
 501  * @gl: the glock the blocks belong to
 502  * @dblock: the starting disk block
 503  * @extlen: the number of blocks in the extent
 504  *
 505  * returns: the first buffer in the extent
 506  */
 507
 508 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 509 {
 510         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 511         struct buffer_head *first_bh, *bh;
 512         u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 513                           sdp->sd_sb.sb_bsize_shift;
 514
 515         BUG_ON(!extlen);
 516
 517         if (max_ra < 1)
 518                 max_ra = 1;
 519         if (extlen > max_ra)
 520                 extlen = max_ra;
 521
 522         first_bh = gfs2_getbuf(gl, dblock, CREATE);
 523
 524         if (buffer_uptodate(first_bh))
 525                 goto out;
 526         bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
 527
 528         dblock++;
 529         extlen--;
 530
 531         while (extlen) {
 532                 bh = gfs2_getbuf(gl, dblock, CREATE);
 533
 534                 bh_readahead(bh, REQ_RAHEAD | REQ_META | REQ_PRIO);
 535                 brelse(bh);
 536                 dblock++;
 537                 extlen--;
 538                 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
 539                         goto out;
 540         }
 541
 542         wait_on_buffer(first_bh);
 543 out:
 544         return first_bh;
 545 }
 546