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         .writepage = gfs2_aspace_writepage,
  93         .releasepage = gfs2_releasepage,
  94 };
  95
  96 const struct address_space_operations gfs2_rgrp_aops = {
  97         .writepage = gfs2_aspace_writepage,
  98         .releasepage = gfs2_releasepage,
  99 };
 100
 101 /**
 102  * gfs2_getbuf - Get a buffer with a given address space
 103  * @gl: the glock
 104  * @blkno: the block number (filesystem scope)
 105  * @create: 1 if the buffer should be created
 106  *
 107  * Returns: the buffer
 108  */
 109
 110 struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
 111 {
 112         struct address_space *mapping = gfs2_glock2aspace(gl);
 113         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 114         struct page *page;
 115         struct buffer_head *bh;
 116         unsigned int shift;
 117         unsigned long index;
 118         unsigned int bufnum;
 119
 120         if (mapping == NULL)
 121                 mapping = &sdp->sd_aspace;
 122
 123         shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 124         index = blkno >> shift;             /* convert block to page */
 125         bufnum = blkno - (index << shift);  /* block buf index within page */
 126
 127         if (create) {
 128                 for (;;) {
 129                         page = grab_cache_page(mapping, index);
 130                         if (page)
 131                                 break;
 132                         yield();
 133                 }
 134         } else {
 135                 page = find_get_page_flags(mapping, index,
 136                                                 FGP_LOCK|FGP_ACCESSED);
 137                 if (!page)
 138                         return NULL;
 139         }
 140
 141         if (!page_has_buffers(page))
 142                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 143
 144         /* Locate header for our buffer within our page */
 145         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 146                 /* Do nothing */;
 147         get_bh(bh);
 148
 149         if (!buffer_mapped(bh))
 150                 map_bh(bh, sdp->sd_vfs, blkno);
 151
 152         unlock_page(page);
 153         put_page(page);
 154
 155         return bh;
 156 }
 157
 158 static void meta_prep_new(struct buffer_head *bh)
 159 {
 160         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 161
 162         lock_buffer(bh);
 163         clear_buffer_dirty(bh);
 164         set_buffer_uptodate(bh);
 165         unlock_buffer(bh);
 166
 167         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 168 }
 169
 170 /**
 171  * gfs2_meta_new - Get a block
 172  * @gl: The glock associated with this block
 173  * @blkno: The block number
 174  *
 175  * Returns: The buffer
 176  */
 177
 178 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 179 {
 180         struct buffer_head *bh;
 181         bh = gfs2_getbuf(gl, blkno, CREATE);
 182         meta_prep_new(bh);
 183         return bh;
 184 }
 185
 186 static void gfs2_meta_read_endio(struct bio *bio)
 187 {
 188         struct bio_vec *bvec;
 189         struct bvec_iter_all iter_all;
 190
 191         bio_for_each_segment_all(bvec, bio, iter_all) {
 192                 struct page *page = bvec->bv_page;
 193                 struct buffer_head *bh = page_buffers(page);
 194                 unsigned int len = bvec->bv_len;
 195
 196                 while (bh_offset(bh) < bvec->bv_offset)
 197                         bh = bh->b_this_page;
 198                 do {
 199                         struct buffer_head *next = bh->b_this_page;
 200                         len -= bh->b_size;
 201                         bh->b_end_io(bh, !bio->bi_status);
 202                         bh = next;
 203                 } while (bh && len);
 204         }
 205         bio_put(bio);
 206 }
 207
 208 /*
 209  * Submit several consecutive buffer head I/O requests as a single bio I/O
 210  * request.  (See submit_bh_wbc.)
 211  */
 212 static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[],
 213                             int num)
 214 {
 215         while (num > 0) {
 216                 struct buffer_head *bh = *bhs;
 217                 struct bio *bio;
 218
 219                 bio = bio_alloc(GFP_NOIO, num);
 220                 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 221                 bio_set_dev(bio, bh->b_bdev);
 222                 while (num > 0) {
 223                         bh = *bhs;
 224                         if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
 225                                 BUG_ON(bio->bi_iter.bi_size == 0);
 226                                 break;
 227                         }
 228                         bhs++;
 229                         num--;
 230                 }
 231                 bio->bi_end_io = gfs2_meta_read_endio;
 232                 bio_set_op_attrs(bio, op, op_flags);
 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  * @bhp: the place where the buffer is returned (NULL on failure)
 243  *
 244  * Returns: errno
 245  */
 246
 247 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 248                    int rahead, struct buffer_head **bhp)
 249 {
 250         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 251         struct buffer_head *bh, *bhs[2];
 252         int num = 0;
 253
 254         if (unlikely(gfs2_withdrawn(sdp)) &&
 255             (!sdp->sd_jdesc || (blkno != sdp->sd_jdesc->jd_no_addr))) {
 256                 *bhp = NULL;
 257                 return -EIO;
 258         }
 259
 260         *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
 261
 262         lock_buffer(bh);
 263         if (buffer_uptodate(bh)) {
 264                 unlock_buffer(bh);
 265                 flags &= ~DIO_WAIT;
 266         } else {
 267                 bh->b_end_io = end_buffer_read_sync;
 268                 get_bh(bh);
 269                 bhs[num++] = bh;
 270         }
 271
 272         if (rahead) {
 273                 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
 274
 275                 lock_buffer(bh);
 276                 if (buffer_uptodate(bh)) {
 277                         unlock_buffer(bh);
 278                         brelse(bh);
 279                 } else {
 280                         bh->b_end_io = end_buffer_read_sync;
 281                         bhs[num++] = bh;
 282                 }
 283         }
 284
 285         gfs2_submit_bhs(REQ_OP_READ, REQ_META | REQ_PRIO, bhs, num);
 286         if (!(flags & DIO_WAIT))
 287                 return 0;
 288
 289         bh = *bhp;
 290         wait_on_buffer(bh);
 291         if (unlikely(!buffer_uptodate(bh))) {
 292                 struct gfs2_trans *tr = current->journal_info;
 293                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 294                         gfs2_io_error_bh_wd(sdp, bh);
 295                 brelse(bh);
 296                 *bhp = NULL;
 297                 return -EIO;
 298         }
 299
 300         return 0;
 301 }
 302
 303 /**
 304  * gfs2_meta_wait - Reread a block from disk
 305  * @sdp: the filesystem
 306  * @bh: The block to wait for
 307  *
 308  * Returns: errno
 309  */
 310
 311 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
 312 {
 313         if (unlikely(gfs2_withdrawn(sdp)))
 314                 return -EIO;
 315
 316         wait_on_buffer(bh);
 317
 318         if (!buffer_uptodate(bh)) {
 319                 struct gfs2_trans *tr = current->journal_info;
 320                 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
 321                         gfs2_io_error_bh_wd(sdp, bh);
 322                 return -EIO;
 323         }
 324         if (unlikely(gfs2_withdrawn(sdp)))
 325                 return -EIO;
 326
 327         return 0;
 328 }
 329
 330 void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
 331 {
 332         struct address_space *mapping = bh->b_page->mapping;
 333         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 334         struct gfs2_bufdata *bd = bh->b_private;
 335         struct gfs2_trans *tr = current->journal_info;
 336         int was_pinned = 0;
 337
 338         if (test_clear_buffer_pinned(bh)) {
 339                 trace_gfs2_pin(bd, 0);
 340                 atomic_dec(&sdp->sd_log_pinned);
 341                 list_del_init(&bd->bd_list);
 342                 if (meta == REMOVE_META)
 343                         tr->tr_num_buf_rm++;
 344                 else
 345                         tr->tr_num_databuf_rm++;
 346                 set_bit(TR_TOUCHED, &tr->tr_flags);
 347                 was_pinned = 1;
 348                 brelse(bh);
 349         }
 350         if (bd) {
 351                 spin_lock(&sdp->sd_ail_lock);
 352                 if (bd->bd_tr) {
 353                         gfs2_trans_add_revoke(sdp, bd);
 354                 } else if (was_pinned) {
 355                         bh->b_private = NULL;
 356                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 357                 }
 358                 spin_unlock(&sdp->sd_ail_lock);
 359         }
 360         clear_buffer_dirty(bh);
 361         clear_buffer_uptodate(bh);
 362 }
 363
 364 /**
 365  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 366  * @ip: the inode who owns the buffers
 367  * @bstart: the first buffer in the run
 368  * @blen: the number of buffers in the run
 369  *
 370  */
 371
 372 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
 373 {
 374         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 375         struct buffer_head *bh;
 376
 377         while (blen) {
 378                 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
 379                 if (bh) {
 380                         lock_buffer(bh);
 381                         gfs2_log_lock(sdp);
 382                         gfs2_remove_from_journal(bh, REMOVE_META);
 383                         gfs2_log_unlock(sdp);
 384                         unlock_buffer(bh);
 385                         brelse(bh);
 386                 }
 387
 388                 bstart++;
 389                 blen--;
 390         }
 391 }
 392
 393 /**
 394  * gfs2_meta_indirect_buffer - Get a metadata buffer
 395  * @ip: The GFS2 inode
 396  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 397  * @num: The block number (device relative) of the buffer
 398  * @bhp: the buffer is returned here
 399  *
 400  * Returns: errno
 401  */
 402
 403 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
 404                               struct buffer_head **bhp)
 405 {
 406         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 407         struct gfs2_glock *gl = ip->i_gl;
 408         struct buffer_head *bh;
 409         int ret = 0;
 410         u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
 411         int rahead = 0;
 412
 413         if (num == ip->i_no_addr)
 414                 rahead = ip->i_rahead;
 415
 416         ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
 417         if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
 418                 brelse(bh);
 419                 ret = -EIO;
 420         } else {
 421                 *bhp = bh;
 422         }
 423         return ret;
 424 }
 425
 426 /**
 427  * gfs2_meta_ra - start readahead on an extent of a file
 428  * @gl: the glock the blocks belong to
 429  * @dblock: the starting disk block
 430  * @extlen: the number of blocks in the extent
 431  *
 432  * returns: the first buffer in the extent
 433  */
 434
 435 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 436 {
 437         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 438         struct buffer_head *first_bh, *bh;
 439         u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 440                           sdp->sd_sb.sb_bsize_shift;
 441
 442         BUG_ON(!extlen);
 443
 444         if (max_ra < 1)
 445                 max_ra = 1;
 446         if (extlen > max_ra)
 447                 extlen = max_ra;
 448
 449         first_bh = gfs2_getbuf(gl, dblock, CREATE);
 450
 451         if (buffer_uptodate(first_bh))
 452                 goto out;
 453         if (!buffer_locked(first_bh))
 454                 ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &first_bh);
 455
 456         dblock++;
 457         extlen--;
 458
 459         while (extlen) {
 460                 bh = gfs2_getbuf(gl, dblock, CREATE);
 461
 462                 if (!buffer_uptodate(bh) && !buffer_locked(bh))
 463                         ll_rw_block(REQ_OP_READ,
 464                                     REQ_RAHEAD | REQ_META | REQ_PRIO,
 465                                     1, &bh);
 466                 brelse(bh);
 467                 dblock++;
 468                 extlen--;
 469                 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
 470                         goto out;
 471         }
 472
 473         wait_on_buffer(first_bh);
 474 out:
 475         return first_bh;
 476 }
 477