Exemple #1
0
static int
traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
    const blkptr_t *bp, const zbookmark_phys_t *zb)
{
	zbookmark_phys_t czb;
	int err = 0;
	arc_buf_t *buf = NULL;
	prefetch_data_t *pd = td->td_pfd;
	boolean_t hard = td->td_flags & TRAVERSE_HARD;

	switch (resume_skip_check(td, dnp, zb)) {
	case RESUME_SKIP_ALL:
		return (0);
	case RESUME_SKIP_CHILDREN:
		goto post;
	case RESUME_SKIP_NONE:
		break;
	default:
		ASSERT(0);
	}

	if (bp->blk_birth == 0) {
		/*
		 * Since this block has a birth time of 0 it must be one of
		 * two things: a hole created before the
		 * SPA_FEATURE_HOLE_BIRTH feature was enabled, or a hole
		 * which has always been a hole in an object.
		 *
		 * If a file is written sparsely, then the unwritten parts of
		 * the file were "always holes" -- that is, they have been
		 * holes since this object was allocated.  However, we (and
		 * our callers) can not necessarily tell when an object was
		 * allocated.  Therefore, if it's possible that this object
		 * was freed and then its object number reused, we need to
		 * visit all the holes with birth==0.
		 *
		 * If it isn't possible that the object number was reused,
		 * then if SPA_FEATURE_HOLE_BIRTH was enabled before we wrote
		 * all the blocks we will visit as part of this traversal,
		 * then this hole must have always existed, so we can skip
		 * it.  We visit blocks born after (exclusive) td_min_txg.
		 *
		 * Note that the meta-dnode cannot be reallocated.
		 */
		if (!send_holes_without_birth_time &&
		    (!td->td_realloc_possible ||
		    zb->zb_object == DMU_META_DNODE_OBJECT) &&
		    td->td_hole_birth_enabled_txg <= td->td_min_txg)
			return (0);
	} else if (bp->blk_birth <= td->td_min_txg) {
		return (0);
	}

	if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) {
		uint64_t size = BP_GET_LSIZE(bp);
		mutex_enter(&pd->pd_mtx);
		ASSERT(pd->pd_bytes_fetched >= 0);
		while (pd->pd_bytes_fetched < size && !pd->pd_exited)
			cv_wait(&pd->pd_cv, &pd->pd_mtx);
		pd->pd_bytes_fetched -= size;
		cv_broadcast(&pd->pd_cv);
		mutex_exit(&pd->pd_mtx);
	}

	if (BP_IS_HOLE(bp)) {
		err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
		if (err != 0)
			goto post;
		return (0);
	}

	if (td->td_flags & TRAVERSE_PRE) {
		err = td->td_func(td->td_spa, NULL, bp, zb, dnp,
		    td->td_arg);
		if (err == TRAVERSE_VISIT_NO_CHILDREN)
			return (0);
		if (err != 0)
			goto post;
	}

	if (BP_GET_LEVEL(bp) > 0) {
		arc_flags_t flags = ARC_FLAG_WAIT;
		int i;
		blkptr_t *cbp;
		int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;

		err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
		if (err != 0)
			goto post;
		cbp = buf->b_data;

		for (i = 0; i < epb; i++) {
			SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
			    zb->zb_level - 1,
			    zb->zb_blkid * epb + i);
			traverse_prefetch_metadata(td, &cbp[i], &czb);
		}

		/* recursively visitbp() blocks below this */
		for (i = 0; i < epb; i++) {
			SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
			    zb->zb_level - 1,
			    zb->zb_blkid * epb + i);
			err = traverse_visitbp(td, dnp, &cbp[i], &czb);
			if (err != 0)
				break;
		}
	} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
Exemple #2
0
static int
traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
    const blkptr_t *bp, const zbookmark_phys_t *zb)
{
	zbookmark_phys_t czb;
	int err = 0;
	arc_buf_t *buf = NULL;
	prefetch_data_t *pd = td->td_pfd;
	boolean_t hard = td->td_flags & TRAVERSE_HARD;

	switch (resume_skip_check(td, dnp, zb)) {
	case RESUME_SKIP_ALL:
		return (0);
	case RESUME_SKIP_CHILDREN:
		goto post;
	case RESUME_SKIP_NONE:
		break;
	default:
		ASSERT(0);
	}

	if (bp->blk_birth == 0) {
		/*
		 * Since this block has a birth time of 0 it must be a
		 * hole created before the SPA_FEATURE_HOLE_BIRTH
		 * feature was enabled.  If SPA_FEATURE_HOLE_BIRTH
		 * was enabled before the min_txg for this traveral we
		 * know the hole must have been created before the
		 * min_txg for this traveral, so we can skip it. If
		 * SPA_FEATURE_HOLE_BIRTH was enabled after the min_txg
		 * for this traveral we cannot tell if the hole was
		 * created before or after the min_txg for this
		 * traversal, so we cannot skip it.
		 */
		if (td->td_hole_birth_enabled_txg < td->td_min_txg)
			return (0);
	} else if (bp->blk_birth <= td->td_min_txg) {
		return (0);
	}

	if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) {
		mutex_enter(&pd->pd_mtx);
		ASSERT(pd->pd_blks_fetched >= 0);
		while (pd->pd_blks_fetched == 0 && !pd->pd_exited)
			cv_wait(&pd->pd_cv, &pd->pd_mtx);
		pd->pd_blks_fetched--;
		cv_broadcast(&pd->pd_cv);
		mutex_exit(&pd->pd_mtx);
	}

	if (BP_IS_HOLE(bp)) {
		err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
		if (err != 0)
			goto post;
		return (0);
	}

	if (td->td_flags & TRAVERSE_PRE) {
		err = td->td_func(td->td_spa, NULL, bp, zb, dnp,
		    td->td_arg);
		if (err == TRAVERSE_VISIT_NO_CHILDREN)
			return (0);
		if (err != 0)
			goto post;
	}

	if (BP_GET_LEVEL(bp) > 0) {
		arc_flags_t flags = ARC_FLAG_WAIT;
		int i;
		blkptr_t *cbp;
		int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;

		err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
		if (err != 0)
			goto post;
		cbp = buf->b_data;

		for (i = 0; i < epb; i++) {
			SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
			    zb->zb_level - 1,
			    zb->zb_blkid * epb + i);
			traverse_prefetch_metadata(td, &cbp[i], &czb);
		}

		/* recursively visitbp() blocks below this */
		for (i = 0; i < epb; i++) {
			SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
			    zb->zb_level - 1,
			    zb->zb_blkid * epb + i);
			err = traverse_visitbp(td, dnp, &cbp[i], &czb);
			if (err != 0)
				break;
		}
	} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {