journal.c

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    reiserfs_panic(s, "journal-615: buffer write failed\n") ;
  }
  atomic_dec(&(jl->j_commit_left)) ;
  bforget(jl->j_commit_bh) ;

  /* now, every commit block is on the disk.  It is safe to allow blocks freed during this transaction to be reallocated */
  cleanup_freed_for_journal_list(s, jl) ;

  if (flushall) {
    atomic_set(&(jl->j_older_commits_done), 1) ;
  }
  atomic_set(&(jl->j_commit_flushing), 0) ;
  wake_up(&(jl->j_commit_wait)) ;

  s->s_dirt = 1 ;
  return 0 ;
}

/*
** flush_journal_list frequently needs to find a newer transaction for a given block.  This does that, or 
** returns NULL if it can't find anything 
*/
static struct reiserfs_journal_list *find_newer_jl_for_cn(struct reiserfs_journal_cnode *cn) {
  kdev_t dev = cn->dev;
  unsigned long blocknr = cn->blocknr ;

  cn = cn->hprev ;
  while(cn) {
    if (cn->dev == dev && cn->blocknr == blocknr && cn->jlist) {
      return cn->jlist ;
    }
    cn = cn->hprev ;
  }
  return NULL ;
}


/*
** once all the real blocks have been flushed, it is safe to remove them from the
** journal list for this transaction.  Aside from freeing the cnode, this also allows the
** block to be reallocated for data blocks if it had been deleted.
*/
static void remove_all_from_journal_list(struct super_block *p_s_sb, struct reiserfs_journal_list *jl, int debug) {
  struct buffer_head fake_bh ;
  struct reiserfs_journal_cnode *cn, *last ;
  cn = jl->j_realblock ;

  /* which is better, to lock once around the whole loop, or
  ** to lock for each call to remove_from_journal_list?
  */
  while(cn) {
    if (cn->blocknr != 0) {
      if (debug) {
        printk("block %lu, bh is %d, state %ld\n", cn->blocknr, cn->bh ? 1: 0, 
	        cn->state) ;
      }
      fake_bh.b_blocknr = cn->blocknr ;
      fake_bh.b_dev = cn->dev ;
      cn->state = 0 ;
      remove_from_journal_list(p_s_sb, jl, &fake_bh, 1) ;
    }
    last = cn ;
    cn = cn->next ;
    free_cnode(p_s_sb, last) ;
  }
  jl->j_realblock = NULL ;
}

/*
** if this timestamp is greater than the timestamp we wrote last to the header block, write it to the header block.
** once this is done, I can safely say the log area for this transaction won't ever be replayed, and I can start
** releasing blocks in this transaction for reuse as data blocks.
** called by flush_journal_list, before it calls remove_all_from_journal_list
**
*/
static int _update_journal_header_block(struct super_block *p_s_sb, unsigned long offset, unsigned long trans_id) {
  struct reiserfs_journal_header *jh ;
  if (trans_id >= SB_JOURNAL(p_s_sb)->j_last_flush_trans_id) {
    if (buffer_locked((SB_JOURNAL(p_s_sb)->j_header_bh)))  {
      wait_on_buffer((SB_JOURNAL(p_s_sb)->j_header_bh)) ;
      if (!buffer_uptodate(SB_JOURNAL(p_s_sb)->j_header_bh)) {
        reiserfs_panic(p_s_sb, "journal-699: buffer write failed\n") ;
      }
    }
    SB_JOURNAL(p_s_sb)->j_last_flush_trans_id = trans_id ;
    SB_JOURNAL(p_s_sb)->j_first_unflushed_offset = offset ;
    jh = (struct reiserfs_journal_header *)(SB_JOURNAL(p_s_sb)->j_header_bh->b_data) ;
    jh->j_last_flush_trans_id = cpu_to_le32(trans_id) ;
    jh->j_first_unflushed_offset = cpu_to_le32(offset) ;
    jh->j_mount_id = cpu_to_le32(SB_JOURNAL(p_s_sb)->j_mount_id) ;
    set_bit(BH_Dirty, &(SB_JOURNAL(p_s_sb)->j_header_bh->b_state)) ;
    ll_rw_block(WRITE, 1, &(SB_JOURNAL(p_s_sb)->j_header_bh)) ;
    wait_on_buffer((SB_JOURNAL(p_s_sb)->j_header_bh)) ; 
    if (!buffer_uptodate(SB_JOURNAL(p_s_sb)->j_header_bh)) {
      printk( "reiserfs: journal-837: IO error during journal replay\n" );
      return -EIO ;
    }
  }
  return 0 ;
}

static int update_journal_header_block(struct super_block *p_s_sb, 
                                       unsigned long offset, 
				       unsigned long trans_id) {
    if (_update_journal_header_block(p_s_sb, offset, trans_id)) {
	reiserfs_panic(p_s_sb, "journal-712: buffer write failed\n") ;
    }
    return 0 ;
}
/* 
** flush any and all journal lists older than you are 
** can only be called from flush_journal_list
*/
static int flush_older_journal_lists(struct super_block *p_s_sb, struct reiserfs_journal_list *jl, unsigned long trans_id) {
  int i, index ;
  struct reiserfs_journal_list *other_jl ;

  index = jl - SB_JOURNAL_LIST(p_s_sb) ;
  for (i = 0 ; i < JOURNAL_LIST_COUNT ; i++) {
    other_jl = SB_JOURNAL_LIST(p_s_sb) + ((index + i) % JOURNAL_LIST_COUNT) ;
    if (other_jl && other_jl->j_len > 0 && 
        other_jl->j_trans_id > 0 && 
	other_jl->j_trans_id < trans_id && 
        other_jl != jl) {
      /* do not flush all */
      flush_journal_list(p_s_sb, other_jl, 0) ; 
    }
  }
  return 0 ;
}

static void reiserfs_end_buffer_io_sync(struct buffer_head *bh, int uptodate) {
    if (buffer_journaled(bh)) {
        reiserfs_warning("clm-2084: pinned buffer %lu:%s sent to disk\n",
	                 bh->b_blocknr, kdevname(bh->b_dev)) ;
    }
    mark_buffer_uptodate(bh, uptodate) ;
    unlock_buffer(bh) ;
    put_bh(bh) ;
}
static void submit_logged_buffer(struct buffer_head *bh) {
    lock_buffer(bh) ;
    get_bh(bh) ;
    bh->b_end_io = reiserfs_end_buffer_io_sync ;
    mark_buffer_notjournal_new(bh) ;
    clear_bit(BH_Dirty, &bh->b_state) ;
    submit_bh(WRITE, bh) ;
}

/* flush a journal list, both commit and real blocks
**
** always set flushall to 1, unless you are calling from inside
** flush_journal_list
**
** IMPORTANT.  This can only be called while there are no journal writers, 
** and the journal is locked.  That means it can only be called from 
** do_journal_end, or by journal_release
*/
static int flush_journal_list(struct super_block *s, 
                              struct reiserfs_journal_list *jl, int flushall) {
  struct reiserfs_journal_list *pjl ;
  struct reiserfs_journal_cnode *cn, *last ;
  int count ;
  int was_jwait = 0 ;
  int was_dirty = 0 ;
  struct buffer_head *saved_bh ; 
  unsigned long j_len_saved = jl->j_len ;

  if (j_len_saved <= 0) {
    return 0 ;
  }

  if (atomic_read(&SB_JOURNAL(s)->j_wcount) != 0) {
    reiserfs_warning("clm-2048: flush_journal_list called with wcount %d\n",
                      atomic_read(&SB_JOURNAL(s)->j_wcount)) ;
  }
  /* if someone is getting the commit list, we must wait for them */
  while (atomic_read(&(jl->j_commit_flushing))) { 
    sleep_on(&(jl->j_commit_wait)) ;
  }
  /* if someone is flushing this list, we must wait for them */
  while (atomic_read(&(jl->j_flushing))) {
    sleep_on(&(jl->j_flush_wait)) ;
  }

  /* this list is now ours, we can change anything we want */
  atomic_set(&(jl->j_flushing), 1) ;

  count = 0 ;
  if (j_len_saved > JOURNAL_TRANS_MAX) {
    reiserfs_panic(s, "journal-715: flush_journal_list, length is %lu, list number %d\n", j_len_saved, jl - SB_JOURNAL_LIST(s)) ;
    atomic_dec(&(jl->j_flushing)) ;
    return 0 ;
  }

  /* if all the work is already done, get out of here */
  if (atomic_read(&(jl->j_nonzerolen)) <= 0 && 
      atomic_read(&(jl->j_commit_left)) <= 0) {
    goto flush_older_and_return ;
  } 

  /* start by putting the commit list on disk.  This will also flush 
  ** the commit lists of any olders transactions
  */
  flush_commit_list(s, jl, 1) ;

  /* are we done now? */
  if (atomic_read(&(jl->j_nonzerolen)) <= 0 && 
      atomic_read(&(jl->j_commit_left)) <= 0) {
    goto flush_older_and_return ;
  }

  /* loop through each cnode, see if we need to write it, 
  ** or wait on a more recent transaction, or just ignore it 
  */
  if (atomic_read(&(SB_JOURNAL(s)->j_wcount)) != 0) {
    reiserfs_panic(s, "journal-844: panic journal list is flushing, wcount is not 0\n") ;
  }
  cn = jl->j_realblock ;
  while(cn) {
    was_jwait = 0 ;
    was_dirty = 0 ;
    saved_bh = NULL ;
    /* blocknr of 0 is no longer in the hash, ignore it */
    if (cn->blocknr == 0) {
      goto free_cnode ;
    }
    pjl = find_newer_jl_for_cn(cn) ;
    /* the order is important here.  We check pjl to make sure we
    ** don't clear BH_JDirty_wait if we aren't the one writing this
    ** block to disk
    */
    if (!pjl && cn->bh) {
      saved_bh = cn->bh ;

      /* we do this to make sure nobody releases the buffer while 
      ** we are working with it 
      */
      get_bh(saved_bh) ;

      if (buffer_journal_dirty(saved_bh)) {
        was_jwait = 1 ;
	mark_buffer_notjournal_dirty(saved_bh) ;
        /* undo the inc from journal_mark_dirty */
	put_bh(saved_bh) ;
      }
      if (can_dirty(cn)) {
        was_dirty = 1 ;
      }
    }

    /* if someone has this block in a newer transaction, just make
    ** sure they are commited, and don't try writing it to disk
    */
    if (pjl) {
      flush_commit_list(s, pjl, 1) ;
      goto free_cnode ;
    }

    /* bh == NULL when the block got to disk on its own, OR, 
    ** the block got freed in a future transaction 
    */
    if (saved_bh == NULL) {
      goto free_cnode ;
    }

    /* this should never happen.  kupdate_one_transaction has this list
    ** locked while it works, so we should never see a buffer here that
    ** is not marked JDirty_wait
    */
    if ((!was_jwait) && !buffer_locked(saved_bh)) {
printk("journal-813: BAD! buffer %lu %cdirty %cjwait, not in a newer tranasction\n", saved_bh->b_blocknr,
        was_dirty ? ' ' : '!', was_jwait ? ' ' : '!') ;
    }
    /* kupdate_one_transaction waits on the buffers it is writing, so we
    ** should never see locked buffers here
    */
    if (buffer_locked(saved_bh)) {
      printk("clm-2083: locked buffer %lu in flush_journal_list\n", 
              saved_bh->b_blocknr) ;
      wait_on_buffer(saved_bh) ;
      if (!buffer_uptodate(saved_bh)) {
        reiserfs_panic(s, "journal-923: buffer write failed\n") ;
      }
    } 
    if (was_dirty) { 
      /* we inc again because saved_bh gets decremented at free_cnode */
      get_bh(saved_bh) ;
      set_bit(BLOCK_NEEDS_FLUSH, &cn->state) ;
      submit_logged_buffer(saved_bh) ;
      count++ ;
    } else {
      printk("clm-2082: Unable to flush buffer %lu in flush_journal_list\n",
              saved_bh->b_blocknr) ;
    }
free_cnode:
    last = cn ;
    cn = cn->next ;
    if (saved_bh) {
      /* we incremented this to keep others from taking the buffer head away */
      put_bh(saved_bh) ;
      if (atomic_read(&(saved_bh->b_count)) < 0) {
        printk("journal-945: saved_bh->b_count < 0") ;
      }
    }
  }
  if (count > 0) {
    cn = jl->j_realblock ;
    while(cn) {
      if (test_bit(BLOCK_NEEDS_FLUSH, &cn->state)) {
	if (!cn->bh) {
	  reiserfs_panic(s, "journal-1011: cn->bh is NULL\n") ;
	}
	wait_on_buffer(cn->bh) ;
	if (!cn->bh) {
	  reiserfs_panic(s, "journal-1012: cn->bh is NULL\n") ;
	}
	if (!buffer_uptodate(cn->bh)) {
	  reiserfs_panic(s, "journal-949: buffer write failed\n") ;
	}
	refile_buffer(cn->bh) ;
        brelse(cn->bh) ;
      }
      cn = cn->next ;
    }
  }

flush_older_and_return:
  /* before we can update the journal header block, we _must_ flush all 
  ** real blocks from all older transactions to disk.  This is because
  ** once the header block is updated, this transaction will not be
  ** replayed after a crash
  */
  if (flushall) {
    flush_older_journal_lists(s, jl, jl->j_trans_id) ;
  } 
  
  /* before we can remove everything from the hash tables for this 
  ** transaction, we must make sure it can never be replayed
  **
  ** since we are only called from do_journal_end, we know for sure there
  ** are no allocations going on while we are flushing journal lists.  So,
  ** we only need to update the journal header block for the last list
  ** being flushed
  */
  if (flushall) {
    update_journal_header_block(s, (jl->j_start + jl->j_len + 2) % JOURNAL_BLOCK_COUNT, jl->j_trans_id) ;
  }
  remove_all_from_journal_list(s, jl, 0) ;
  jl->j_len = 0 ;
  atomic_set(&(jl->j_nonzerolen), 0) ;
  jl->j_start = 0 ;
  jl->j_realblock = NULL ;
  jl->j_commit_bh = NULL ;
  jl->j_trans_id = 0 ;
  atomic_dec(&(jl->j_flushing)) ;
  wake_up(&(jl->j_flush_wait)) ;
  return 0 ;
} 


static int kupdate_one_transaction(struct super_block *s,
                                    struct reiserfs_journal_list *jl) 
{
    struct reiserfs_journal_list *pjl ; /* previous list for this cn */
    struct reiserfs_journal_cnode *cn, *walk_cn ;
    unsigned long blocknr ;
    int run = 0 ;
    int orig_trans_id = jl->j_trans_id ;
    struct buffer_head *saved_bh ; 
    int ret = 0 ;