fs/gfs2/meta_io.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/mm.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/writeback.h>
  18 #include <linux/swap.h>
  19 #include <linux/delay.h>
  20 #include <linux/bio.h>
  21 #include <linux/gfs2_ondisk.h>
  22 #include <linux/lm_interface.h>
  23
  24 #include "gfs2.h"
  25 #include "incore.h"
  26 #include "glock.h"
  27 #include "glops.h"
  28 #include "inode.h"
  29 #include "log.h"
  30 #include "lops.h"
  31 #include "meta_io.h"
  32 #include "rgrp.h"
  33 #include "trans.h"
  34 #include "util.h"
  35 #include "ops_address.h"
  36
  37 static int aspace_get_block(struct inode *inode, sector_t lblock,
  38                             struct buffer_head *bh_result, int create)
  39 {
  40         gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
  41         return -EOPNOTSUPP;
  42 }
  43
  44 static int gfs2_aspace_writepage(struct page *page,
  45                                  struct writeback_control *wbc)
  46 {
  47         return block_write_full_page(page, aspace_get_block, wbc);
  48 }
  49
  50 static const struct address_space_operations aspace_aops = {
  51         .writepage = gfs2_aspace_writepage,
  52         .releasepage = gfs2_releasepage,
  53         .sync_page = block_sync_page,
  54 };
  55
  56 /**
  57  * gfs2_aspace_get - Create and initialize a struct inode structure
  58  * @sdp: the filesystem the aspace is in
  59  *
  60  * Right now a struct inode is just a struct inode.  Maybe Linux
  61  * will supply a more lightweight address space construct (that works)
  62  * in the future.
  63  *
  64  * Make sure pages/buffers in this aspace aren't in high memory.
  65  *
  66  * Returns: the aspace
  67  */
  68
  69 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
  70 {
  71         struct inode *aspace;
  72         struct gfs2_inode *ip;
  73
  74         aspace = new_inode(sdp->sd_vfs);
  75         if (aspace) {
  76                 mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
  77                 aspace->i_mapping->a_ops = &aspace_aops;
  78                 aspace->i_size = ~0ULL;
  79                 ip = GFS2_I(aspace);
  80                 clear_bit(GIF_USER, &ip->i_flags);
  81                 insert_inode_hash(aspace);
  82         }
  83         return aspace;
  84 }
  85
  86 void gfs2_aspace_put(struct inode *aspace)
  87 {
  88         remove_inode_hash(aspace);
  89         iput(aspace);
  90 }
  91
  92 /**
  93  * gfs2_meta_inval - Invalidate all buffers associated with a glock
  94  * @gl: the glock
  95  *
  96  */
  97
  98 void gfs2_meta_inval(struct gfs2_glock *gl)
  99 {
 100         struct gfs2_sbd *sdp = gl->gl_sbd;
 101         struct inode *aspace = gl->gl_aspace;
 102         struct address_space *mapping = gl->gl_aspace->i_mapping;
 103
 104         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 105
 106         atomic_inc(&aspace->i_writecount);
 107         truncate_inode_pages(mapping, 0);
 108         atomic_dec(&aspace->i_writecount);
 109
 110         gfs2_assert_withdraw(sdp, !mapping->nrpages);
 111 }
 112
 113 /**
 114  * gfs2_meta_sync - Sync all buffers associated with a glock
 115  * @gl: The glock
 116  *
 117  */
 118
 119 void gfs2_meta_sync(struct gfs2_glock *gl)
 120 {
 121         struct address_space *mapping = gl->gl_aspace->i_mapping;
 122         int error;
 123
 124         filemap_fdatawrite(mapping);
 125         error = filemap_fdatawait(mapping);
 126
 127         if (error)
 128                 gfs2_io_error(gl->gl_sbd);
 129 }
 130
 131 /**
 132  * getbuf - Get a buffer with a given address space
 133  * @gl: the glock
 134  * @blkno: the block number (filesystem scope)
 135  * @create: 1 if the buffer should be created
 136  *
 137  * Returns: the buffer
 138  */
 139
 140 static struct buffer_head *getbuf(struct gfs2_glock *gl, u64 blkno, int create)
 141 {
 142         struct address_space *mapping = gl->gl_aspace->i_mapping;
 143         struct gfs2_sbd *sdp = gl->gl_sbd;
 144         struct page *page;
 145         struct buffer_head *bh;
 146         unsigned int shift;
 147         unsigned long index;
 148         unsigned int bufnum;
 149
 150         shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 151         index = blkno >> shift;             /* convert block to page */
 152         bufnum = blkno - (index << shift);  /* block buf index within page */
 153
 154         if (create) {
 155                 for (;;) {
 156                         page = grab_cache_page(mapping, index);
 157                         if (page)
 158                                 break;
 159                         yield();
 160                 }
 161         } else {
 162                 page = find_lock_page(mapping, index);
 163                 if (!page)
 164                         return NULL;
 165         }
 166
 167         if (!page_has_buffers(page))
 168                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 169
 170         /* Locate header for our buffer within our page */
 171         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 172                 /* Do nothing */;
 173         get_bh(bh);
 174
 175         if (!buffer_mapped(bh))
 176                 map_bh(bh, sdp->sd_vfs, blkno);
 177
 178         unlock_page(page);
 179         mark_page_accessed(page);
 180         page_cache_release(page);
 181
 182         return bh;
 183 }
 184
 185 static void meta_prep_new(struct buffer_head *bh)
 186 {
 187         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 188
 189         lock_buffer(bh);
 190         clear_buffer_dirty(bh);
 191         set_buffer_uptodate(bh);
 192         unlock_buffer(bh);
 193
 194         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 195 }
 196
 197 /**
 198  * gfs2_meta_new - Get a block
 199  * @gl: The glock associated with this block
 200  * @blkno: The block number
 201  *
 202  * Returns: The buffer
 203  */
 204
 205 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 206 {
 207         struct buffer_head *bh;
 208         bh = getbuf(gl, blkno, CREATE);
 209         meta_prep_new(bh);
 210         return bh;
 211 }
 212
 213 /**
 214  * gfs2_meta_read - Read a block from disk
 215  * @gl: The glock covering the block
 216  * @blkno: The block number
 217  * @flags: flags
 218  * @bhp: the place where the buffer is returned (NULL on failure)
 219  *
 220  * Returns: errno
 221  */
 222
 223 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 224                    struct buffer_head **bhp)
 225 {
 226         *bhp = getbuf(gl, blkno, CREATE);
 227         if (!buffer_uptodate(*bhp)) {
 228                 ll_rw_block(READ_META, 1, bhp);
 229                 if (flags & DIO_WAIT) {
 230                         int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
 231                         if (error) {
 232                                 brelse(*bhp);
 233                                 return error;
 234                         }
 235                 }
 236         }
 237
 238         return 0;
 239 }
 240
 241 /**
 242  * gfs2_meta_wait - Reread a block from disk
 243  * @sdp: the filesystem
 244  * @bh: The block to wait for
 245  *
 246  * Returns: errno
 247  */
 248
 249 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
 250 {
 251         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 252                 return -EIO;
 253
 254         wait_on_buffer(bh);
 255
 256         if (!buffer_uptodate(bh)) {
 257                 struct gfs2_trans *tr = current->journal_info;
 258                 if (tr && tr->tr_touched)
 259                         gfs2_io_error_bh(sdp, bh);
 260                 return -EIO;
 261         }
 262         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 263                 return -EIO;
 264
 265         return 0;
 266 }
 267
 268 /**
 269  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
 270  * @gl: the glock the buffer belongs to
 271  * @bh: The buffer to be attached to
 272  * @meta: Flag to indicate whether its metadata or not
 273  */
 274
 275 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 276                          int meta)
 277 {
 278         struct gfs2_bufdata *bd;
 279
 280         if (meta)
 281                 lock_page(bh->b_page);
 282
 283         if (bh->b_private) {
 284                 if (meta)
 285                         unlock_page(bh->b_page);
 286                 return;
 287         }
 288
 289         bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
 290         bd->bd_bh = bh;
 291         bd->bd_gl = gl;
 292
 293         INIT_LIST_HEAD(&bd->bd_list_tr);
 294         if (meta)
 295                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
 296         else
 297                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
 298         bh->b_private = bd;
 299
 300         if (meta)
 301                 unlock_page(bh->b_page);
 302 }
 303
 304 void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
 305 {
 306         struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
 307         struct gfs2_bufdata *bd = bh->b_private;
 308         if (test_clear_buffer_pinned(bh)) {
 309                 list_del_init(&bd->bd_le.le_list);
 310                 if (meta) {
 311                         gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
 312                         sdp->sd_log_num_buf--;
 313                         tr->tr_num_buf_rm++;
 314                 } else {
 315                         gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
 316                         sdp->sd_log_num_databuf--;
 317                         tr->tr_num_databuf_rm++;
 318                 }
 319                 tr->tr_touched = 1;
 320                 brelse(bh);
 321         }
 322         if (bd) {
 323                 if (bd->bd_ail) {
 324                         gfs2_remove_from_ail(bd);
 325                         bh->b_private = NULL;
 326                         bd->bd_bh = NULL;
 327                         bd->bd_blkno = bh->b_blocknr;
 328                         gfs2_trans_add_revoke(sdp, bd);
 329                 }
 330         }
 331         clear_buffer_dirty(bh);
 332         clear_buffer_uptodate(bh);
 333 }
 334
 335 /**
 336  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 337  * @ip: the inode who owns the buffers
 338  * @bstart: the first buffer in the run
 339  * @blen: the number of buffers in the run
 340  *
 341  */
 342
 343 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
 344 {
 345         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 346         struct buffer_head *bh;
 347
 348         while (blen) {
 349                 bh = getbuf(ip->i_gl, bstart, NO_CREATE);
 350                 if (bh) {
 351                         lock_buffer(bh);
 352                         gfs2_log_lock(sdp);
 353                         gfs2_remove_from_journal(bh, current->journal_info, 1);
 354                         gfs2_log_unlock(sdp);
 355                         unlock_buffer(bh);
 356                         brelse(bh);
 357                 }
 358
 359                 bstart++;
 360                 blen--;
 361         }
 362 }
 363
 364 /**
 365  * gfs2_meta_indirect_buffer - Get a metadata buffer
 366  * @ip: The GFS2 inode
 367  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 368  * @num: The block number (device relative) of the buffer
 369  * @new: Non-zero if we may create a new buffer
 370  * @bhp: the buffer is returned here
 371  *
 372  * Returns: errno
 373  */
 374
 375 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
 376                               int new, struct buffer_head **bhp)
 377 {
 378         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 379         struct gfs2_glock *gl = ip->i_gl;
 380         struct buffer_head *bh;
 381         int ret = 0;
 382
 383         if (new) {
 384                 BUG_ON(height == 0);
 385                 bh = gfs2_meta_new(gl, num);
 386                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 387                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 388                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 389         } else {
 390                 u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
 391                 ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
 392                 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
 393                         brelse(bh);
 394                         ret = -EIO;
 395                 }
 396         }
 397         *bhp = bh;
 398         return ret;
 399 }
 400
 401 /**
 402  * gfs2_meta_ra - start readahead on an extent of a file
 403  * @gl: the glock the blocks belong to
 404  * @dblock: the starting disk block
 405  * @extlen: the number of blocks in the extent
 406  *
 407  * returns: the first buffer in the extent
 408  */
 409
 410 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 411 {
 412         struct gfs2_sbd *sdp = gl->gl_sbd;
 413         struct buffer_head *first_bh, *bh;
 414         u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 415                           sdp->sd_sb.sb_bsize_shift;
 416
 417         BUG_ON(!extlen);
 418
 419         if (max_ra < 1)
 420                 max_ra = 1;
 421         if (extlen > max_ra)
 422                 extlen = max_ra;
 423
 424         first_bh = getbuf(gl, dblock, CREATE);
 425
 426         if (buffer_uptodate(first_bh))
 427                 goto out;
 428         if (!buffer_locked(first_bh))
 429                 ll_rw_block(READ_META, 1, &first_bh);
 430
 431         dblock++;
 432         extlen--;
 433
 434         while (extlen) {
 435                 bh = getbuf(gl, dblock, CREATE);
 436
 437                 if (!buffer_uptodate(bh) && !buffer_locked(bh))
 438                         ll_rw_block(READA, 1, &bh);
 439                 brelse(bh);
 440                 dblock++;
 441                 extlen--;
 442                 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
 443                         goto out;
 444         }
 445
 446         wait_on_buffer(first_bh);
 447 out:
 448         return first_bh;
 449 }
 450