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 page *page;
 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                 for (;;) {
 133                         page = grab_cache_page(mapping, index);
 134                         if (page)
 135                                 break;
 136                         yield();
 137                 }
 138                 if (!page_has_buffers(page))
 139                         create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 140         } else {
 141                 page = find_get_page_flags(mapping, index,
 142                                                 FGP_LOCK|FGP_ACCESSED);
 143                 if (!page)
 144                         return NULL;
 145                 if (!page_has_buffers(page)) {
 146                         bh = NULL;
 147                         goto out_unlock;
 148                 }
 149         }
 150
 151         /* Locate header for our buffer within our page */
 152         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 153                 /* Do nothing */;
 154         get_bh(bh);
 155
 156         if (!buffer_mapped(bh))
 157                 map_bh(bh, sdp->sd_vfs, blkno);
 158
 159 out_unlock:
 160         unlock_page(page);
 161         put_page(page);
 162
 163         return bh;
 164 }
 165
 166 static void meta_prep_new(struct buffer_head *bh)
 167 {
 168         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 169
 170         lock_buffer(bh);
 171         clear_buffer_dirty(bh);
 172         set_buffer_uptodate(bh);
 173         unlock_buffer(bh);
 174
 175         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 176 }
 177
 178 /**
 179  * gfs2_meta_new - Get a block
 180  * @gl: The glock associated with this block
 181  * @blkno: The block number
 182  *
 183  * Returns: The buffer
 184  */
 185
 186 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 187 {
 188         struct buffer_head *bh;
 189         bh = gfs2_getbuf(gl, blkno, CREATE);
 190         meta_prep_new(bh);
 191         return bh;
 192 }
 193
 194 static void gfs2_meta_read_endio(struct bio *bio)
 195 {
 196         struct bio_vec *bvec;
 197         struct bvec_iter_all iter_all;
 198
 199         bio_for_each_segment_all(bvec, bio, iter_all) {
 200                 struct page *page = bvec->bv_page;
 201                 struct buffer_head *bh = page_buffers(page);
 202                 unsigned int len = bvec->bv_len;
 203
 204                 while (bh_offset(bh) < bvec->bv_offset)
 205                         bh = bh->b_this_page;
 206                 do {
 207                         struct buffer_head *next = bh->b_this_page;
 208                         len -= bh->b_size;
 209                         bh->b_end_io(bh, !bio->bi_status);
 210                         bh = next;
 211                 } while (bh && len);
 212         }
 213         bio_put(bio);
 214 }
 215
 216 /*
 217  * Submit several consecutive buffer head I/O requests as a single bio I/O
 218  * request.  (See submit_bh_wbc.)
 219  */
 220 static void gfs2_submit_bhs(blk_opf_t opf, struct buffer_head *bhs[], int num)
 221 {
 222         while (num > 0) {
 223                 struct buffer_head *bh = *bhs;
 224                 struct bio *bio;
 225
 226                 bio = bio_alloc(bh->b_bdev, num, opf, GFP_NOIO);
 227                 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 228                 while (num > 0) {
 229                         bh = *bhs;
 230                         if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
 231                                 BUG_ON(bio->bi_iter.bi_size == 0);
 232                                 break;
 233                         }
 234                         bhs++;
 235                         num--;
 236                 }
 237                 bio->bi_end_io = gfs2_meta_read_endio;
 238                 submit_bio(bio);
 239         }
 240 }
 241
 242 /**
 243  * gfs2_meta_read - Read a block from disk
 244  * @gl: The glock covering the block
 245  * @blkno: The block number
 246  * @flags: flags
 247  * @rahead: Do read-ahead
 248  * @bhp: the place where the buffer is returned (NULL on failure)
 249  *
 250  * Returns: errno
 251  */
 252
 253 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 254                    int rahead, struct buffer_head **bhp)
 255 {
 256         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 257         struct buffer_head *bh, *bhs[2];
 258         int num = 0;
 259
 260         if (unlikely(gfs2_withdrawn(sdp)) && !gfs2_withdraw_in_prog(sdp)) {
 261                 *bhp = NULL;
 262                 return -EIO;
 263         }
 264
 265         *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
 266
 267         lock_buffer(bh);
 268         if (buffer_uptodate(bh)) {
 269                 unlock_buffer(bh);
 270                 flags &= ~DIO_WAIT;
 271         } else {
 272                 bh->b_end_io = end_buffer_read_sync;
 273                 get_bh(bh);
 274                 bhs[num++] = bh;
 275         }
 276
 277         if (rahead) {
 278                 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
 279
 280                 lock_buffer(bh);
 281                 if (buffer_uptodate(bh)) {
 282                         unlock_buffer(bh);
 283                         brelse(bh);
 284                 } else {
 285                         bh->b_end_io = end_buffer_read_sync;
 286                         bhs[num++] = bh;
 287                 }
 288         }
 289
 290         gfs2_submit_bhs(REQ_OP_READ | REQ_META | REQ_PRIO, bhs, num);
 291         if (!(flags & DIO_WAIT))
 292                 return 0;
 293
 294         bh = *bhp;
 295         wait_on_buffer(bh);
 296         if (unlikely(!buffer_uptodate(bh))) {
 297                 struct gfs2_trans *tr = current->journal_info;
 298                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 299                         gfs2_io_error_bh_wd(sdp, bh);
 300                 brelse(bh);
 301                 *bhp = NULL;
 302                 return -EIO;
 303         }
 304
 305         return 0;
 306 }
 307
 308 /**
 309  * gfs2_meta_wait - Reread a block from disk
 310  * @sdp: the filesystem
 311  * @bh: The block to wait for
 312  *
 313  * Returns: errno
 314  */
 315
 316 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
 317 {
 318         if (unlikely(gfs2_withdrawn(sdp)) && !gfs2_withdraw_in_prog(sdp))
 319                 return -EIO;
 320
 321         wait_on_buffer(bh);
 322
 323         if (!buffer_uptodate(bh)) {
 324                 struct gfs2_trans *tr = current->journal_info;
 325                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 326                         gfs2_io_error_bh_wd(sdp, bh);
 327                 return -EIO;
 328         }
 329         if (unlikely(gfs2_withdrawn(sdp)) && !gfs2_withdraw_in_prog(sdp))
 330                 return -EIO;
 331
 332         return 0;
 333 }
 334
 335 void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
 336 {
 337         struct address_space *mapping = bh->b_page->mapping;
 338         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 339         struct gfs2_bufdata *bd = bh->b_private;
 340         struct gfs2_trans *tr = current->journal_info;
 341         int was_pinned = 0;
 342
 343         if (test_clear_buffer_pinned(bh)) {
 344                 trace_gfs2_pin(bd, 0);
 345                 atomic_dec(&sdp->sd_log_pinned);
 346                 list_del_init(&bd->bd_list);
 347                 if (meta == REMOVE_META)
 348                         tr->tr_num_buf_rm++;
 349                 else
 350                         tr->tr_num_databuf_rm++;
 351                 set_bit(TR_TOUCHED, &tr->tr_flags);
 352                 was_pinned = 1;
 353                 brelse(bh);
 354         }
 355         if (bd) {
 356                 if (bd->bd_tr) {
 357                         gfs2_trans_add_revoke(sdp, bd);
 358                 } else if (was_pinned) {
 359                         bh->b_private = NULL;
 360                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 361                 } else if (!list_empty(&bd->bd_ail_st_list) &&
 362                                         !list_empty(&bd->bd_ail_gl_list)) {
 363                         gfs2_remove_from_ail(bd);
 364                 }
 365         }
 366         clear_buffer_dirty(bh);
 367         clear_buffer_uptodate(bh);
 368 }
 369
 370 /**
 371  * gfs2_ail1_wipe - remove deleted/freed buffers from the ail1 list
 372  * @sdp: superblock
 373  * @bstart: starting block address of buffers to remove
 374  * @blen: length of buffers to be removed
 375  *
 376  * This function is called from gfs2_journal wipe, whose job is to remove
 377  * buffers, corresponding to deleted blocks, from the journal. If we find any
 378  * bufdata elements on the system ail1 list, they haven't been written to
 379  * the journal yet. So we remove them.
 380  */
 381 static void gfs2_ail1_wipe(struct gfs2_sbd *sdp, u64 bstart, u32 blen)
 382 {
 383         struct gfs2_trans *tr, *s;
 384         struct gfs2_bufdata *bd, *bs;
 385         struct buffer_head *bh;
 386         u64 end = bstart + blen;
 387
 388         gfs2_log_lock(sdp);
 389         spin_lock(&sdp->sd_ail_lock);
 390         list_for_each_entry_safe(tr, s, &sdp->sd_ail1_list, tr_list) {
 391                 list_for_each_entry_safe(bd, bs, &tr->tr_ail1_list,
 392                                          bd_ail_st_list) {
 393                         bh = bd->bd_bh;
 394                         if (bh->b_blocknr < bstart || bh->b_blocknr >= end)
 395                                 continue;
 396
 397                         gfs2_remove_from_journal(bh, REMOVE_JDATA);
 398                 }
 399         }
 400         spin_unlock(&sdp->sd_ail_lock);
 401         gfs2_log_unlock(sdp);
 402 }
 403
 404 static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
 405 {
 406         struct address_space *mapping = ip->i_inode.i_mapping;
 407         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 408         struct page *page;
 409         struct buffer_head *bh;
 410         unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 411         unsigned long index = blkno >> shift; /* convert block to page */
 412         unsigned int bufnum = blkno - (index << shift);
 413
 414         page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED);
 415         if (!page)
 416                 return NULL;
 417         if (!page_has_buffers(page)) {
 418                 unlock_page(page);
 419                 put_page(page);
 420                 return NULL;
 421         }
 422         /* Locate header for our buffer within our page */
 423         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 424                 /* Do nothing */;
 425         get_bh(bh);
 426         unlock_page(page);
 427         put_page(page);
 428         return bh;
 429 }
 430
 431 /**
 432  * gfs2_journal_wipe - make inode's buffers so they aren't dirty/pinned anymore
 433  * @ip: the inode who owns the buffers
 434  * @bstart: the first buffer in the run
 435  * @blen: the number of buffers in the run
 436  *
 437  */
 438
 439 void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
 440 {
 441         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 442         struct buffer_head *bh;
 443         int ty;
 444
 445         gfs2_ail1_wipe(sdp, bstart, blen);
 446         while (blen) {
 447                 ty = REMOVE_META;
 448                 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
 449                 if (!bh && gfs2_is_jdata(ip)) {
 450                         bh = gfs2_getjdatabuf(ip, bstart);
 451                         ty = REMOVE_JDATA;
 452                 }
 453                 if (bh) {
 454                         lock_buffer(bh);
 455                         gfs2_log_lock(sdp);
 456                         spin_lock(&sdp->sd_ail_lock);
 457                         gfs2_remove_from_journal(bh, ty);
 458                         spin_unlock(&sdp->sd_ail_lock);
 459                         gfs2_log_unlock(sdp);
 460                         unlock_buffer(bh);
 461                         brelse(bh);
 462                 }
 463
 464                 bstart++;
 465                 blen--;
 466         }
 467 }
 468
 469 /**
 470  * gfs2_meta_buffer - Get a metadata buffer
 471  * @ip: The GFS2 inode
 472  * @mtype: The block type (GFS2_METATYPE_*)
 473  * @num: The block number (device relative) of the buffer
 474  * @bhp: the buffer is returned here
 475  *
 476  * Returns: errno
 477  */
 478
 479 int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num,
 480                      struct buffer_head **bhp)
 481 {
 482         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 483         struct gfs2_glock *gl = ip->i_gl;
 484         struct buffer_head *bh;
 485         int ret = 0;
 486         int rahead = 0;
 487
 488         if (num == ip->i_no_addr)
 489                 rahead = ip->i_rahead;
 490
 491         ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
 492         if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
 493                 brelse(bh);
 494                 ret = -EIO;
 495         } else {
 496                 *bhp = bh;
 497         }
 498         return ret;
 499 }
 500
 501 /**
 502  * gfs2_meta_ra - start readahead on an extent of a file
 503  * @gl: the glock the blocks belong to
 504  * @dblock: the starting disk block
 505  * @extlen: the number of blocks in the extent
 506  *
 507  * returns: the first buffer in the extent
 508  */
 509
 510 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 511 {
 512         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 513         struct buffer_head *first_bh, *bh;
 514         u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 515                           sdp->sd_sb.sb_bsize_shift;
 516
 517         BUG_ON(!extlen);
 518
 519         if (max_ra < 1)
 520                 max_ra = 1;
 521         if (extlen > max_ra)
 522                 extlen = max_ra;
 523
 524         first_bh = gfs2_getbuf(gl, dblock, CREATE);
 525
 526         if (buffer_uptodate(first_bh))
 527                 goto out;
 528         bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
 529
 530         dblock++;
 531         extlen--;
 532
 533         while (extlen) {
 534                 bh = gfs2_getbuf(gl, dblock, CREATE);
 535
 536                 bh_readahead(bh, REQ_RAHEAD | REQ_META | REQ_PRIO);
 537                 brelse(bh);
 538                 dblock++;
 539                 extlen--;
 540                 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
 541                         goto out;
 542         }
 543
 544         wait_on_buffer(first_bh);
 545 out:
 546         return first_bh;
 547 }
 548