static boolean_t
dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp,
const zbookmark_t *zb)
{
/*
* We never skip over user/group accounting objects (obj<0)
*/
if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) &&
(int64_t)zb->zb_object >= 0) {
/*
* If we already visited this bp & everything below (in
* a prior txg sync), don't bother doing it again.
*/
if (zbookmark_is_before(dnp, zb, &scn->scn_phys.scn_bookmark))
return (B_TRUE);
/*
* If we found the block we're trying to resume from, or
* we went past it to a different object, zero it out to
* indicate that it's OK to start checking for pausing
* again.
*/
if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 ||
zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) {
dprintf("resuming at %llx/%llx/%llx/%llx\n",
(longlong_t)zb->zb_objset,
(longlong_t)zb->zb_object,
(longlong_t)zb->zb_level,
(longlong_t)zb->zb_blkid);
bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb));
}
}
return (B_FALSE);
}
/*
* Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and
* the block indicated by zb does not need to be visited at all. Returns
* RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the
* resume point. This indicates that this block should be visited but not its
* children (since they must have been visited in a previous traversal).
* Otherwise returns RESUME_SKIP_NONE.
*/
static resume_skip_t
resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp,
const zbookmark_t *zb)
{
if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) {
/*
* If we already visited this bp & everything below,
* don't bother doing it again.
*/
if (zbookmark_is_before(dnp, zb, td->td_resume))
return (RESUME_SKIP_ALL);
/*
* If we found the block we're trying to resume from, zero
* the bookmark out to indicate that we have resumed.
*/
ASSERT3U(zb->zb_object, <=, td->td_resume->zb_object);
if (bcmp(zb, td->td_resume, sizeof (*zb)) == 0) {
bzero(td->td_resume, sizeof (*zb));
if (td->td_flags & TRAVERSE_POST)
return (RESUME_SKIP_CHILDREN);
}
}
return (RESUME_SKIP_NONE);
}
static boolean_t
dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_t *zb)
{
uint64_t elapsed_nanosecs;
int mintime;
/* we never skip user/group accounting objects */
if (zb && (int64_t)zb->zb_object < 0)
return (B_FALSE);
if (scn->scn_pausing)
return (B_TRUE); /* we're already pausing */
if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark))
return (B_FALSE); /* we're resuming */
/* We only know how to resume from level-0 blocks. */
if (zb && zb->zb_level != 0)
return (B_FALSE);
mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ?
zfs_resilver_min_time_ms : zfs_scan_min_time_ms;
elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time;
if (elapsed_nanosecs / NANOSEC > zfs_txg_timeout ||
(NSEC2MSEC(elapsed_nanosecs) > mintime &&
txg_sync_waiting(scn->scn_dp)) ||
spa_shutting_down(scn->scn_dp->dp_spa)) {
if (zb) {
dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n",
(longlong_t)zb->zb_objset,
(longlong_t)zb->zb_object,
(longlong_t)zb->zb_level,
(longlong_t)zb->zb_blkid);
scn->scn_phys.scn_bookmark = *zb;
}
dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n",
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor);
scn->scn_pausing = B_TRUE;
return (B_TRUE);
}
return (B_FALSE);
}
static void
traverse_prefetch_metadata(traverse_data_t *td,
const blkptr_t *bp, const zbookmark_t *zb)
{
uint32_t flags = ARC_NOWAIT | ARC_PREFETCH;
if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA))
return;
/*
* If we are in the process of resuming, don't prefetch, because
* some children will not be needed (and in fact may have already
* been freed).
*/
if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume))
return;
if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg)
return;
if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)
return;
(void) arc_read(NULL, td->td_spa, bp, NULL, NULL,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
}
