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         int 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         .set_page_dirty = __set_page_dirty_buffers,
  93         .writepage = gfs2_aspace_writepage,
  94         .releasepage = gfs2_releasepage,
  95 };
  96
  97 const struct address_space_operations gfs2_rgrp_aops = {
  98         .set_page_dirty = __set_page_dirty_buffers,
  99         .writepage = gfs2_aspace_writepage,
 100         .releasepage = gfs2_releasepage,
 101 };
 102
 103 /**
 104  * gfs2_getbuf - Get a buffer with a given address space
 105  * @gl: the glock
 106  * @blkno: the block number (filesystem scope)
 107  * @create: 1 if the buffer should be created
 108  *
 109  * Returns: the buffer
 110  */
 111
 112 struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
 113 {
 114         struct address_space *mapping = gfs2_glock2aspace(gl);
 115         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 116         struct page *page;
 117         struct buffer_head *bh;
 118         unsigned int shift;
 119         unsigned long index;
 120         unsigned int bufnum;
 121
 122         if (mapping == NULL)
 123                 mapping = &sdp->sd_aspace;
 124
 125         shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 126         index = blkno >> shift;             /* convert block to page */
 127         bufnum = blkno - (index << shift);  /* block buf index within page */
 128
 129         if (create) {
 130                 for (;;) {
 131                         page = grab_cache_page(mapping, index);
 132                         if (page)
 133                                 break;
 134                         yield();
 135                 }
 136                 if (!page_has_buffers(page))
 137                         create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 138         } else {
 139                 page = find_get_page_flags(mapping, index,
 140                                                 FGP_LOCK|FGP_ACCESSED);
 141                 if (!page)
 142                         return NULL;
 143                 if (!page_has_buffers(page)) {
 144                         bh = NULL;
 145                         goto out_unlock;
 146                 }
 147         }
 148
 149         /* Locate header for our buffer within our page */
 150         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 151                 /* Do nothing */;
 152         get_bh(bh);
 153
 154         if (!buffer_mapped(bh))
 155                 map_bh(bh, sdp->sd_vfs, blkno);
 156
 157 out_unlock:
 158         unlock_page(page);
 159         put_page(page);
 160
 161         return bh;
 162 }
 163
 164 static void meta_prep_new(struct buffer_head *bh)
 165 {
 166         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 167
 168         lock_buffer(bh);
 169         clear_buffer_dirty(bh);
 170         set_buffer_uptodate(bh);
 171         unlock_buffer(bh);
 172
 173         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 174 }
 175
 176 /**
 177  * gfs2_meta_new - Get a block
 178  * @gl: The glock associated with this block
 179  * @blkno: The block number
 180  *
 181  * Returns: The buffer
 182  */
 183
 184 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 185 {
 186         struct buffer_head *bh;
 187         bh = gfs2_getbuf(gl, blkno, CREATE);
 188         meta_prep_new(bh);
 189         return bh;
 190 }
 191
 192 static void gfs2_meta_read_endio(struct bio *bio)
 193 {
 194         struct bio_vec *bvec;
 195         struct bvec_iter_all iter_all;
 196
 197         bio_for_each_segment_all(bvec, bio, iter_all) {
 198                 struct page *page = bvec->bv_page;
 199                 struct buffer_head *bh = page_buffers(page);
 200                 unsigned int len = bvec->bv_len;
 201
 202                 while (bh_offset(bh) < bvec->bv_offset)
 203                         bh = bh->b_this_page;
 204                 do {
 205                         struct buffer_head *next = bh->b_this_page;
 206                         len -= bh->b_size;
 207                         bh->b_end_io(bh, !bio->bi_status);
 208                         bh = next;
 209                 } while (bh && len);
 210         }
 211         bio_put(bio);
 212 }
 213
 214 /*
 215  * Submit several consecutive buffer head I/O requests as a single bio I/O
 216  * request.  (See submit_bh_wbc.)
 217  */
 218 static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[],
 219                             int num)
 220 {
 221         while (num > 0) {
 222                 struct buffer_head *bh = *bhs;
 223                 struct bio *bio;
 224
 225                 bio = bio_alloc(GFP_NOIO, num);
 226                 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 227                 bio_set_dev(bio, bh->b_bdev);
 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                 bio_set_op_attrs(bio, op, op_flags);
 239                 submit_bio(bio);
 240         }
 241 }
 242
 243 /**
 244  * gfs2_meta_read - Read a block from disk
 245  * @gl: The glock covering the block
 246  * @blkno: The block number
 247  * @flags: flags
 248  * @rahead: Do read-ahead
 249  * @bhp: the place where the buffer is returned (NULL on failure)
 250  *
 251  * Returns: errno
 252  */
 253
 254 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 255                    int rahead, struct buffer_head **bhp)
 256 {
 257         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 258         struct buffer_head *bh, *bhs[2];
 259         int num = 0;
 260
 261         if (unlikely(gfs2_withdrawn(sdp)) &&
 262             (!sdp->sd_jdesc || gl != sdp->sd_jinode_gl)) {
 263                 *bhp = NULL;
 264                 return -EIO;
 265         }
 266
 267         *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
 268
 269         lock_buffer(bh);
 270         if (buffer_uptodate(bh)) {
 271                 unlock_buffer(bh);
 272                 flags &= ~DIO_WAIT;
 273         } else {
 274                 bh->b_end_io = end_buffer_read_sync;
 275                 get_bh(bh);
 276                 bhs[num++] = bh;
 277         }
 278
 279         if (rahead) {
 280                 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
 281
 282                 lock_buffer(bh);
 283                 if (buffer_uptodate(bh)) {
 284                         unlock_buffer(bh);
 285                         brelse(bh);
 286                 } else {
 287                         bh->b_end_io = end_buffer_read_sync;
 288                         bhs[num++] = bh;
 289                 }
 290         }
 291
 292         gfs2_submit_bhs(REQ_OP_READ, REQ_META | REQ_PRIO, bhs, num);
 293         if (!(flags & DIO_WAIT))
 294                 return 0;
 295
 296         bh = *bhp;
 297         wait_on_buffer(bh);
 298         if (unlikely(!buffer_uptodate(bh))) {
 299                 struct gfs2_trans *tr = current->journal_info;
 300                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 301                         gfs2_io_error_bh_wd(sdp, bh);
 302                 brelse(bh);
 303                 *bhp = NULL;
 304                 return -EIO;
 305         }
 306
 307         return 0;
 308 }
 309
 310 /**
 311  * gfs2_meta_wait - Reread a block from disk
 312  * @sdp: the filesystem
 313  * @bh: The block to wait for
 314  *
 315  * Returns: errno
 316  */
 317
 318 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
 319 {
 320         if (unlikely(gfs2_withdrawn(sdp)))
 321                 return -EIO;
 322
 323         wait_on_buffer(bh);
 324
 325         if (!buffer_uptodate(bh)) {
 326                 struct gfs2_trans *tr = current->journal_info;
 327                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 328                         gfs2_io_error_bh_wd(sdp, bh);
 329                 return -EIO;
 330         }
 331         if (unlikely(gfs2_withdrawn(sdp)))
 332                 return -EIO;
 333
 334         return 0;
 335 }
 336
 337 void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
 338 {
 339         struct address_space *mapping = bh->b_page->mapping;
 340         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 341         struct gfs2_bufdata *bd = bh->b_private;
 342         struct gfs2_trans *tr = current->journal_info;
 343         int was_pinned = 0;
 344
 345         if (test_clear_buffer_pinned(bh)) {
 346                 trace_gfs2_pin(bd, 0);
 347                 atomic_dec(&sdp->sd_log_pinned);
 348                 list_del_init(&bd->bd_list);
 349                 if (meta == REMOVE_META)
 350                         tr->tr_num_buf_rm++;
 351                 else
 352                         tr->tr_num_databuf_rm++;
 353                 set_bit(TR_TOUCHED, &tr->tr_flags);
 354                 was_pinned = 1;
 355                 brelse(bh);
 356         }
 357         if (bd) {
 358                 if (bd->bd_tr) {
 359                         gfs2_trans_add_revoke(sdp, bd);
 360                 } else if (was_pinned) {
 361                         bh->b_private = NULL;
 362                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 363                 } else if (!list_empty(&bd->bd_ail_st_list) &&
 364                                         !list_empty(&bd->bd_ail_gl_list)) {
 365                         gfs2_remove_from_ail(bd);
 366                 }
 367         }
 368         clear_buffer_dirty(bh);
 369         clear_buffer_uptodate(bh);
 370 }
 371
 372 /**
 373  * gfs2_ail1_wipe - remove deleted/freed buffers from the ail1 list
 374  * @sdp: superblock
 375  * @bstart: starting block address of buffers to remove
 376  * @blen: length of buffers to be removed
 377  *
 378  * This function is called from gfs2_journal wipe, whose job is to remove
 379  * buffers, corresponding to deleted blocks, from the journal. If we find any
 380  * bufdata elements on the system ail1 list, they haven't been written to
 381  * the journal yet. So we remove them.
 382  */
 383 static void gfs2_ail1_wipe(struct gfs2_sbd *sdp, u64 bstart, u32 blen)
 384 {
 385         struct gfs2_trans *tr, *s;
 386         struct gfs2_bufdata *bd, *bs;
 387         struct buffer_head *bh;
 388         u64 end = bstart + blen;
 389
 390         gfs2_log_lock(sdp);
 391         spin_lock(&sdp->sd_ail_lock);
 392         list_for_each_entry_safe(tr, s, &sdp->sd_ail1_list, tr_list) {
 393                 list_for_each_entry_safe(bd, bs, &tr->tr_ail1_list,
 394                                          bd_ail_st_list) {
 395                         bh = bd->bd_bh;
 396                         if (bh->b_blocknr < bstart || bh->b_blocknr >= end)
 397                                 continue;
 398
 399                         gfs2_remove_from_journal(bh, REMOVE_JDATA);
 400                 }
 401         }
 402         spin_unlock(&sdp->sd_ail_lock);
 403         gfs2_log_unlock(sdp);
 404 }
 405
 406 static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
 407 {
 408         struct address_space *mapping = ip->i_inode.i_mapping;
 409         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 410         struct page *page;
 411         struct buffer_head *bh;
 412         unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 413         unsigned long index = blkno >> shift; /* convert block to page */
 414         unsigned int bufnum = blkno - (index << shift);
 415
 416         page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED);
 417         if (!page)
 418                 return NULL;
 419         if (!page_has_buffers(page)) {
 420                 unlock_page(page);
 421                 put_page(page);
 422                 return NULL;
 423         }
 424         /* Locate header for our buffer within our page */
 425         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 426                 /* Do nothing */;
 427         get_bh(bh);
 428         unlock_page(page);
 429         put_page(page);
 430         return bh;
 431 }
 432
 433 /**
 434  * gfs2_journal_wipe - make inode's buffers so they aren't dirty/pinned anymore
 435  * @ip: the inode who owns the buffers
 436  * @bstart: the first buffer in the run
 437  * @blen: the number of buffers in the run
 438  *
 439  */
 440
 441 void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
 442 {
 443         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 444         struct buffer_head *bh;
 445         int ty;
 446
 447         gfs2_ail1_wipe(sdp, bstart, blen);
 448         while (blen) {
 449                 ty = REMOVE_META;
 450                 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
 451                 if (!bh && gfs2_is_jdata(ip)) {
 452                         bh = gfs2_getjdatabuf(ip, bstart);
 453                         ty = REMOVE_JDATA;
 454                 }
 455                 if (bh) {
 456                         lock_buffer(bh);
 457                         gfs2_log_lock(sdp);
 458                         spin_lock(&sdp->sd_ail_lock);
 459                         gfs2_remove_from_journal(bh, ty);
 460                         spin_unlock(&sdp->sd_ail_lock);
 461                         gfs2_log_unlock(sdp);
 462                         unlock_buffer(bh);
 463                         brelse(bh);
 464                 }
 465
 466                 bstart++;
 467                 blen--;
 468         }
 469 }
 470
 471 /**
 472  * gfs2_meta_buffer - Get a metadata buffer
 473  * @ip: The GFS2 inode
 474  * @mtype: The block type (GFS2_METATYPE_*)
 475  * @num: The block number (device relative) of the buffer
 476  * @bhp: the buffer is returned here
 477  *
 478  * Returns: errno
 479  */
 480
 481 int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num,
 482                      struct buffer_head **bhp)
 483 {
 484         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 485         struct gfs2_glock *gl = ip->i_gl;
 486         struct buffer_head *bh;
 487         int ret = 0;
 488         int rahead = 0;
 489
 490         if (num == ip->i_no_addr)
 491                 rahead = ip->i_rahead;
 492
 493         ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
 494         if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
 495                 brelse(bh);
 496                 ret = -EIO;
 497         } else {
 498                 *bhp = bh;
 499         }
 500         return ret;
 501 }
 502
 503 /**
 504  * gfs2_meta_ra - start readahead on an extent of a file
 505  * @gl: the glock the blocks belong to
 506  * @dblock: the starting disk block
 507  * @extlen: the number of blocks in the extent
 508  *
 509  * returns: the first buffer in the extent
 510  */
 511
 512 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 513 {
 514         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 515         struct buffer_head *first_bh, *bh;
 516         u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 517                           sdp->sd_sb.sb_bsize_shift;
 518
 519         BUG_ON(!extlen);
 520
 521         if (max_ra < 1)
 522                 max_ra = 1;
 523         if (extlen > max_ra)
 524                 extlen = max_ra;
 525
 526         first_bh = gfs2_getbuf(gl, dblock, CREATE);
 527
 528         if (buffer_uptodate(first_bh))
 529                 goto out;
 530         if (!buffer_locked(first_bh))
 531                 ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &first_bh);
 532
 533         dblock++;
 534         extlen--;
 535
 536         while (extlen) {
 537                 bh = gfs2_getbuf(gl, dblock, CREATE);
 538
 539                 if (!buffer_uptodate(bh) && !buffer_locked(bh))
 540                         ll_rw_block(REQ_OP_READ,
 541                                     REQ_RAHEAD | REQ_META | REQ_PRIO,
 542                                     1, &bh);
 543                 brelse(bh);
 544                 dblock++;
 545                 extlen--;
 546                 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
 547                         goto out;
 548         }
 549
 550         wait_on_buffer(first_bh);
 551 out:
 552         return first_bh;
 553 }
 554