Esempio n. 1
0
File: mmu.c Progetto: 0x00evil/linux
/**
 * stage2_wp_range() - write protect stage2 memory region range
 * @kvm:	The KVM pointer
 * @addr:	Start address of range
 * @end:	End address of range
 */
static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
{
	pgd_t *pgd;
	phys_addr_t next;

	pgd = kvm->arch.pgd + kvm_pgd_index(addr);
	do {
		/*
		 * Release kvm_mmu_lock periodically if the memory region is
		 * large. Otherwise, we may see kernel panics with
		 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
		 * CONFIG_LOCKDEP. Additionally, holding the lock too long
		 * will also starve other vCPUs.
		 */
		if (need_resched() || spin_needbreak(&kvm->mmu_lock))
			cond_resched_lock(&kvm->mmu_lock);

		next = kvm_pgd_addr_end(addr, end);
		if (pgd_present(*pgd))
			stage2_wp_puds(pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}
Esempio n. 2
0
int jbd2_log_do_checkpoint(journal_t *journal)
{
    transaction_t *transaction;
    tid_t this_tid;
    int result;

    jbd_debug(1, "Start checkpoint\n");

    result = jbd2_cleanup_journal_tail(journal);
    trace_jbd2_checkpoint(journal, result);
    jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
    if (result <= 0)
        return result;

    result = 0;
    spin_lock(&journal->j_list_lock);
    if (!journal->j_checkpoint_transactions)
        goto out;
    transaction = journal->j_checkpoint_transactions;
    if (transaction->t_chp_stats.cs_chp_time == 0)
        transaction->t_chp_stats.cs_chp_time = jiffies;
    this_tid = transaction->t_tid;
restart:
    if (journal->j_checkpoint_transactions == transaction &&
            transaction->t_tid == this_tid) {
        int batch_count = 0;
        struct journal_head *jh;
        int retry = 0, err;

        while (!retry && transaction->t_checkpoint_list) {
            jh = transaction->t_checkpoint_list;
            retry = __process_buffer(journal, jh, &batch_count,
                                     transaction);
            if (retry < 0 && !result)
                result = retry;
            if (!retry && (need_resched() ||
                           spin_needbreak(&journal->j_list_lock))) {
                spin_unlock(&journal->j_list_lock);
                retry = 1;
                break;
            }
        }

        if (batch_count) {
            if (!retry) {
                spin_unlock(&journal->j_list_lock);
                retry = 1;
            }
            __flush_batch(journal, &batch_count);
        }

        if (retry) {
            spin_lock(&journal->j_list_lock);
            goto restart;
        }
        err = __wait_cp_io(journal, transaction);
        if (!result)
            result = err;
    }
out:
    spin_unlock(&journal->j_list_lock);
    if (result < 0)
        jbd2_journal_abort(journal, result);
    else
        result = jbd2_cleanup_journal_tail(journal);

    return (result < 0) ? result : 0;
}
Esempio n. 3
0
/*
 *  Submit all the data buffers to disk
 */
static int journal_submit_data_buffers(journal_t *journal,
				       transaction_t *commit_transaction,
				       int write_op)
{
	struct journal_head *jh;
	struct buffer_head *bh;
	int locked;
	int bufs = 0;
	struct buffer_head **wbuf = journal->j_wbuf;
	int err = 0;

	/*
	 * Whenever we unlock the journal and sleep, things can get added
	 * onto ->t_sync_datalist, so we have to keep looping back to
	 * write_out_data until we *know* that the list is empty.
	 *
	 * Cleanup any flushed data buffers from the data list.  Even in
	 * abort mode, we want to flush this out as soon as possible.
	 */
write_out_data:
	cond_resched();
	spin_lock(&journal->j_list_lock);

	while (commit_transaction->t_sync_datalist) {
		jh = commit_transaction->t_sync_datalist;
		bh = jh2bh(jh);
		locked = 0;

		/* Get reference just to make sure buffer does not disappear
		 * when we are forced to drop various locks */
		get_bh(bh);
		/* If the buffer is dirty, we need to submit IO and hence
		 * we need the buffer lock. We try to lock the buffer without
		 * blocking. If we fail, we need to drop j_list_lock and do
		 * blocking lock_buffer().
		 */
		if (buffer_dirty(bh)) {
			if (!trylock_buffer(bh)) {
				BUFFER_TRACE(bh, "needs blocking lock");
				spin_unlock(&journal->j_list_lock);
				trace_jbd_do_submit_data(journal,
						     commit_transaction);
				/* Write out all data to prevent deadlocks */
				journal_do_submit_data(wbuf, bufs, write_op);
				bufs = 0;
				lock_buffer(bh);
				spin_lock(&journal->j_list_lock);
			}
			locked = 1;
		}
		/* We have to get bh_state lock. Again out of order, sigh. */
		if (!inverted_lock(journal, bh)) {
			jbd_lock_bh_state(bh);
			spin_lock(&journal->j_list_lock);
		}
		/* Someone already cleaned up the buffer? */
		if (!buffer_jbd(bh) || bh2jh(bh) != jh
			|| jh->b_transaction != commit_transaction
			|| jh->b_jlist != BJ_SyncData) {
			jbd_unlock_bh_state(bh);
			if (locked)
				unlock_buffer(bh);
			BUFFER_TRACE(bh, "already cleaned up");
			release_data_buffer(bh);
			continue;
		}
		if (locked && test_clear_buffer_dirty(bh)) {
			BUFFER_TRACE(bh, "needs writeout, adding to array");
			wbuf[bufs++] = bh;
			__journal_file_buffer(jh, commit_transaction,
						BJ_Locked);
			jbd_unlock_bh_state(bh);
			if (bufs == journal->j_wbufsize) {
				spin_unlock(&journal->j_list_lock);
				trace_jbd_do_submit_data(journal,
						     commit_transaction);
				journal_do_submit_data(wbuf, bufs, write_op);
				bufs = 0;
				goto write_out_data;
			}
		} else if (!locked && buffer_locked(bh)) {
			__journal_file_buffer(jh, commit_transaction,
						BJ_Locked);
			jbd_unlock_bh_state(bh);
			put_bh(bh);
		} else {
			BUFFER_TRACE(bh, "writeout complete: unfile");
			if (unlikely(!buffer_uptodate(bh)))
				err = -EIO;
			__journal_unfile_buffer(jh);
			jbd_unlock_bh_state(bh);
			if (locked)
				unlock_buffer(bh);
			release_data_buffer(bh);
		}

		if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
			spin_unlock(&journal->j_list_lock);
			goto write_out_data;
		}
	}
	spin_unlock(&journal->j_list_lock);
	trace_jbd_do_submit_data(journal, commit_transaction);
	journal_do_submit_data(wbuf, bufs, write_op);

	return err;
}
Esempio n. 4
0
/*
 * Perform an actual checkpoint. We take the first transaction on the
 * list of transactions to be checkpointed and send all its buffers
 * to disk. We submit larger chunks of data at once.
 *
 * The journal should be locked before calling this function.
 * Called with j_checkpoint_mutex held.
 */
int jbd2_log_do_checkpoint(journal_t *journal)
{
	struct journal_head	*jh;
	struct buffer_head	*bh;
	transaction_t		*transaction;
	tid_t			this_tid;
	int			result, batch_count = 0;

	jbd_debug(1, "Start checkpoint\n");

	/*
	 * First thing: if there are any transactions in the log which
	 * don't need checkpointing, just eliminate them from the
	 * journal straight away.
	 */
	result = jbd2_cleanup_journal_tail(journal);
	trace_jbd2_checkpoint(journal, result);
	jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
	if (result <= 0)
		return result;

	/*
	 * OK, we need to start writing disk blocks.  Take one transaction
	 * and write it.
	 */
	result = 0;
	spin_lock(&journal->j_list_lock);
	if (!journal->j_checkpoint_transactions)
		goto out;
	transaction = journal->j_checkpoint_transactions;
	if (transaction->t_chp_stats.cs_chp_time == 0)
		transaction->t_chp_stats.cs_chp_time = jiffies;
	this_tid = transaction->t_tid;
restart:
	/*
	 * If someone cleaned up this transaction while we slept, we're
	 * done (maybe it's a new transaction, but it fell at the same
	 * address).
	 */
	if (journal->j_checkpoint_transactions != transaction ||
	    transaction->t_tid != this_tid)
		goto out;

	/* checkpoint all of the transaction's buffers */
	while (transaction->t_checkpoint_list) {
		jh = transaction->t_checkpoint_list;
		bh = jh2bh(jh);

		if (buffer_locked(bh)) {
			spin_unlock(&journal->j_list_lock);
			get_bh(bh);
			wait_on_buffer(bh);
			/* the journal_head may have gone by now */
			BUFFER_TRACE(bh, "brelse");
			__brelse(bh);
			goto retry;
		}
		if (jh->b_transaction != NULL) {
			transaction_t *t = jh->b_transaction;
			tid_t tid = t->t_tid;

			transaction->t_chp_stats.cs_forced_to_close++;
			spin_unlock(&journal->j_list_lock);
			if (unlikely(journal->j_flags & JBD2_UNMOUNT))
				/*
				 * The journal thread is dead; so
				 * starting and waiting for a commit
				 * to finish will cause us to wait for
				 * a _very_ long time.
				 */
				printk(KERN_ERR
		"JBD2: %s: Waiting for Godot: block %llu\n",
		journal->j_devname, (unsigned long long) bh->b_blocknr);

			jbd2_log_start_commit(journal, tid);
			jbd2_log_wait_commit(journal, tid);
			goto retry;
		}
		if (!buffer_dirty(bh)) {
			if (unlikely(buffer_write_io_error(bh)) && !result)
				result = -EIO;
			BUFFER_TRACE(bh, "remove from checkpoint");
			if (__jbd2_journal_remove_checkpoint(jh))
				/* The transaction was released; we're done */
				goto out;
			continue;
		}
		/*
		 * Important: we are about to write the buffer, and
		 * possibly block, while still holding the journal
		 * lock.  We cannot afford to let the transaction
		 * logic start messing around with this buffer before
		 * we write it to disk, as that would break
		 * recoverability.
		 */
		BUFFER_TRACE(bh, "queue");
		get_bh(bh);
		J_ASSERT_BH(bh, !buffer_jwrite(bh));
		journal->j_chkpt_bhs[batch_count++] = bh;
		__buffer_relink_io(jh);
		transaction->t_chp_stats.cs_written++;
		if ((batch_count == JBD2_NR_BATCH) ||
		    need_resched() ||
		    spin_needbreak(&journal->j_list_lock))
			goto unlock_and_flush;
	}

	if (batch_count) {
		unlock_and_flush:
			spin_unlock(&journal->j_list_lock);
		retry:
			if (batch_count)
				__flush_batch(journal, &batch_count);
			spin_lock(&journal->j_list_lock);
			goto restart;
	}

	/*
	 * Now we issued all of the transaction's buffers, let's deal
	 * with the buffers that are out for I/O.
	 */
restart2:
	/* Did somebody clean up the transaction in the meanwhile? */
	if (journal->j_checkpoint_transactions != transaction ||
	    transaction->t_tid != this_tid)
		goto out;

	while (transaction->t_checkpoint_io_list) {
		jh = transaction->t_checkpoint_io_list;
		bh = jh2bh(jh);
		if (buffer_locked(bh)) {
			spin_unlock(&journal->j_list_lock);
			get_bh(bh);
			wait_on_buffer(bh);
			/* the journal_head may have gone by now */
			BUFFER_TRACE(bh, "brelse");
			__brelse(bh);
			spin_lock(&journal->j_list_lock);
			goto restart2;
		}
		if (unlikely(buffer_write_io_error(bh)) && !result)
			result = -EIO;

		/*
		 * Now in whatever state the buffer currently is, we
		 * know that it has been written out and so we can
		 * drop it from the list
		 */
		if (__jbd2_journal_remove_checkpoint(jh))
			break;
	}
out:
	spin_unlock(&journal->j_list_lock);
	if (result < 0)
		jbd2_journal_abort(journal, result);
	else
		result = jbd2_cleanup_journal_tail(journal);

	return (result < 0) ? result : 0;
}
Esempio n. 5
0
/*
 * Perform an actual checkpoint. We take the first transaction on the
 * list of transactions to be checkpointed and send all its buffers
 * to disk. We submit larger chunks of data at once.
 *
 * The journal should be locked before calling this function.
 * Called with j_checkpoint_mutex held.
 */
int jbd2_log_do_checkpoint(journal_t *journal)
{
	transaction_t *transaction;
	tid_t this_tid;
	int result;

	jbd_debug(1, "Start checkpoint\n");

	/*
	 * First thing: if there are any transactions in the log which
	 * don't need checkpointing, just eliminate them from the
	 * journal straight away.
	 */
	result = jbd2_cleanup_journal_tail(journal);
	trace_jbd2_checkpoint(journal, result);
	jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
	if (result <= 0)
		return result;

	/*
	 * OK, we need to start writing disk blocks.  Take one transaction
	 * and write it.
	 */
	result = 0;
	spin_lock(&journal->j_list_lock);
	if (!journal->j_checkpoint_transactions)
		goto out;
	transaction = journal->j_checkpoint_transactions;
	if (transaction->t_chp_stats.cs_chp_time == 0)
		transaction->t_chp_stats.cs_chp_time = jiffies;
	this_tid = transaction->t_tid;
restart:
	/*
	 * If someone cleaned up this transaction while we slept, we're
	 * done (maybe it's a new transaction, but it fell at the same
	 * address).
	 */
	if (journal->j_checkpoint_transactions == transaction &&
			transaction->t_tid == this_tid) {
		int batch_count = 0;
		struct journal_head *jh;
		int retry = 0, err;

		while (!retry && transaction->t_checkpoint_list) {
			jh = transaction->t_checkpoint_list;
			retry = __process_buffer(journal, jh, &batch_count,
						 transaction);
			if (retry < 0 && !result)
				result = retry;
			if (!retry && (need_resched() ||
				spin_needbreak(&journal->j_list_lock))) {
				spin_unlock(&journal->j_list_lock);
				retry = 1;
				break;
			}
		}

		if (batch_count) {
			if (!retry) {
				spin_unlock(&journal->j_list_lock);
				retry = 1;
			}
			__flush_batch(journal, &batch_count);
		}

		if (retry) {
			spin_lock(&journal->j_list_lock);
			goto restart;
		}
		/*
		 * Now we have cleaned up the first transaction's checkpoint
		 * list. Let's clean up the second one
		 */
		err = __wait_cp_io(journal, transaction);
		if (!result)
			result = err;
	}
out:
	spin_unlock(&journal->j_list_lock);
	if (result < 0)
		jbd2_journal_abort(journal, result);
	else
		result = jbd2_cleanup_journal_tail(journal);

	return (result < 0) ? result : 0;
}