Exemplo n.º 1
0
Arquivo: dm.c Projeto: wxlong/Test
int dm_resume(struct mapped_device *md)
{
	struct bio *def;
	struct dm_table *map = dm_get_table(md);

	down_write(&md->lock);
	if (!map ||
	    !test_bit(DMF_SUSPENDED, &md->flags) ||
	    !dm_table_get_size(map)) {
		up_write(&md->lock);
		dm_table_put(map);
		return -EINVAL;
	}

	dm_table_resume_targets(map);
	clear_bit(DMF_SUSPENDED, &md->flags);
	clear_bit(DMF_BLOCK_IO, &md->flags);

	def = bio_list_get(&md->deferred);
	__flush_deferred_io(md, def);
	up_write(&md->lock);
	__unlock_fs(md);
	dm_table_unplug_all(map);
	dm_table_put(map);

	return 0;
}
Exemplo n.º 2
0
int dm_resume(struct mapped_device *md)
{
	int r = -EINVAL;
	struct bio *def;
	struct dm_table *map = NULL;

	down(&md->suspend_lock);
	if (!dm_suspended(md))
		goto out;

	map = dm_get_table(md);
	if (!map || !dm_table_get_size(map))
		goto out;

	r = dm_table_resume_targets(map);
	if (r)
		goto out;

	down_write(&md->io_lock);
	clear_bit(DMF_BLOCK_IO, &md->flags);

	def = bio_list_get(&md->deferred);
	__flush_deferred_io(md, def);
	up_write(&md->io_lock);

	unlock_fs(md);

	if (md->suspended_bdev) {
		bdput(md->suspended_bdev);
		md->suspended_bdev = NULL;
	}

	clear_bit(DMF_SUSPENDED, &md->flags);

	dm_table_unplug_all(map);

	kobject_uevent(&md->disk->kobj, KOBJ_CHANGE);

	r = 0;

out:
	dm_table_put(map);
	up(&md->suspend_lock);

	return r;
}
Exemplo n.º 3
0
/*
 * We need to be able to change a mapping table under a mounted
 * filesystem.  For example we might want to move some data in
 * the background.  Before the table can be swapped with
 * dm_bind_table, dm_suspend must be called to flush any in
 * flight bios and ensure that any further io gets deferred.
 */
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
{
	struct dm_table *map = NULL;
	unsigned long flags;
	DECLARE_WAITQUEUE(wait, current);
	struct bio *def;
	int r = -EINVAL;
	int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
	int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;

	down(&md->suspend_lock);

	if (dm_suspended(md))
		goto out_unlock;

	map = dm_get_table(md);

	/*
	 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
	 * This flag is cleared before dm_suspend returns.
	 */
	if (noflush)
		set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);

	/* This does not get reverted if there's an error later. */
	dm_table_presuspend_targets(map);

	/* bdget() can stall if the pending I/Os are not flushed */
	if (!noflush) {
		md->suspended_bdev = bdget_disk(md->disk, 0);
		if (!md->suspended_bdev) {
			DMWARN("bdget failed in dm_suspend");
			r = -ENOMEM;
			goto flush_and_out;
		}
	}

	/*
	 * Flush I/O to the device.
	 * noflush supersedes do_lockfs, because lock_fs() needs to flush I/Os.
	 */
	if (do_lockfs && !noflush) {
		r = lock_fs(md);
		if (r)
			goto out;
	}

	/*
	 * First we set the BLOCK_IO flag so no more ios will be mapped.
	 */
	down_write(&md->io_lock);
	set_bit(DMF_BLOCK_IO, &md->flags);

	add_wait_queue(&md->wait, &wait);
	up_write(&md->io_lock);

	/* unplug */
	if (map)
		dm_table_unplug_all(map);

	/*
	 * Then we wait for the already mapped ios to
	 * complete.
	 */
	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);

		if (!atomic_read(&md->pending) || signal_pending(current))
			break;

		io_schedule();
	}
	set_current_state(TASK_RUNNING);

	down_write(&md->io_lock);
	remove_wait_queue(&md->wait, &wait);

	if (noflush) {
		spin_lock_irqsave(&md->pushback_lock, flags);
		clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
		bio_list_merge_head(&md->deferred, &md->pushback);
		bio_list_init(&md->pushback);
		spin_unlock_irqrestore(&md->pushback_lock, flags);
	}

	/* were we interrupted ? */
	r = -EINTR;
	if (atomic_read(&md->pending)) {
		clear_bit(DMF_BLOCK_IO, &md->flags);
		def = bio_list_get(&md->deferred);
		__flush_deferred_io(md, def);
		up_write(&md->io_lock);
		unlock_fs(md);
		goto out; /* pushback list is already flushed, so skip flush */
	}
	up_write(&md->io_lock);

	dm_table_postsuspend_targets(map);

	set_bit(DMF_SUSPENDED, &md->flags);

	r = 0;

flush_and_out:
	if (r && noflush) {
		/*
		 * Because there may be already I/Os in the pushback list,
		 * flush them before return.
		 */
		down_write(&md->io_lock);

		spin_lock_irqsave(&md->pushback_lock, flags);
		clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
		bio_list_merge_head(&md->deferred, &md->pushback);
		bio_list_init(&md->pushback);
		spin_unlock_irqrestore(&md->pushback_lock, flags);

		def = bio_list_get(&md->deferred);
		__flush_deferred_io(md, def);
		up_write(&md->io_lock);
	}

out:
	if (r && md->suspended_bdev) {
		bdput(md->suspended_bdev);
		md->suspended_bdev = NULL;
	}

	dm_table_put(map);

out_unlock:
	up(&md->suspend_lock);
	return r;
}
Exemplo n.º 4
0
Arquivo: dm.c Projeto: ena30/snake-os
/*
 * We need to be able to change a mapping table under a mounted
 * filesystem.  For example we might want to move some data in
 * the background.  Before the table can be swapped with
 * dm_bind_table, dm_suspend must be called to flush any in
 * flight bios and ensure that any further io gets deferred.
 */
int dm_suspend(struct mapped_device *md, int do_lockfs)
{
	struct dm_table *map = NULL;
	DECLARE_WAITQUEUE(wait, current);
	struct bio *def;
	int r = -EINVAL;

	down(&md->suspend_lock);

	if (dm_suspended(md))
		goto out;

	map = dm_get_table(md);

	/* This does not get reverted if there's an error later. */
	dm_table_presuspend_targets(map);

	md->suspended_bdev = bdget_disk(md->disk, 0);
	if (!md->suspended_bdev) {
		DMWARN("bdget failed in dm_suspend");
		r = -ENOMEM;
		goto out;
	}

	/* Flush I/O to the device. */
	if (do_lockfs) {
		r = lock_fs(md);
		if (r)
			goto out;
	}

	/*
	 * First we set the BLOCK_IO flag so no more ios will be mapped.
	 */
	down_write(&md->io_lock);
	set_bit(DMF_BLOCK_IO, &md->flags);

	add_wait_queue(&md->wait, &wait);
	up_write(&md->io_lock);

	/* unplug */
	if (map)
		dm_table_unplug_all(map);

	/*
	 * Then we wait for the already mapped ios to
	 * complete.
	 */
	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);

		if (!atomic_read(&md->pending) || signal_pending(current))
			break;

		io_schedule();
	}
	set_current_state(TASK_RUNNING);

	down_write(&md->io_lock);
	remove_wait_queue(&md->wait, &wait);

	/* were we interrupted ? */
	r = -EINTR;
	if (atomic_read(&md->pending)) {
		clear_bit(DMF_BLOCK_IO, &md->flags);
		def = bio_list_get(&md->deferred);
		__flush_deferred_io(md, def);
		up_write(&md->io_lock);
		unlock_fs(md);
		goto out;
	}
	up_write(&md->io_lock);

	dm_table_postsuspend_targets(map);

	set_bit(DMF_SUSPENDED, &md->flags);

	r = 0;

out:
	if (r && md->suspended_bdev) {
		bdput(md->suspended_bdev);
		md->suspended_bdev = NULL;
	}

	dm_table_put(map);
	up(&md->suspend_lock);
	return r;
}