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Diffstat (limited to 'module/zfs/dsl_scan.c')
-rw-r--r--module/zfs/dsl_scan.c53
1 files changed, 40 insertions, 13 deletions
diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c
index 23c37c7cc..56d410836 100644
--- a/module/zfs/dsl_scan.c
+++ b/module/zfs/dsl_scan.c
@@ -56,6 +56,11 @@ static scan_cb_t dsl_scan_remove_cb;
static dsl_syncfunc_t dsl_scan_cancel_sync;
static void dsl_scan_sync_state(dsl_scan_t *, dmu_tx_t *tx);
+int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */
+int zfs_resilver_delay = 2; /* number of ticks to delay resilver */
+int zfs_scrub_delay = 4; /* number of ticks to delay scrub */
+int zfs_scan_idle = 50; /* idle window in clock ticks */
+
int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */
int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */
int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver per txg */
@@ -601,8 +606,8 @@ dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp,
* done before setting xlateall (similar to dsl_read())
*/
(void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp,
- buf, NULL, NULL, ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
- &flags, &czb);
+ buf, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
+ ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb);
}
static boolean_t
@@ -650,6 +655,7 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
const zbookmark_t *zb, dmu_tx_t *tx, arc_buf_t **bufp)
{
dsl_pool_t *dp = scn->scn_dp;
+ int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD;
int err;
if (BP_GET_LEVEL(bp) > 0) {
@@ -660,7 +666,7 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
err = arc_read_nolock(NULL, dp->dp_spa, bp,
arc_getbuf_func, bufp,
- ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+ ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
@@ -683,7 +689,7 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
err = arc_read_nolock(NULL, dp->dp_spa, bp,
arc_getbuf_func, bufp,
- ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+ ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
@@ -696,7 +702,7 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
err = arc_read_nolock(NULL, dp->dp_spa, bp,
arc_getbuf_func, bufp,
- ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+ ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
@@ -719,7 +725,7 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
err = arc_read_nolock(NULL, dp->dp_spa, bp,
arc_getbuf_func, bufp,
- ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+ ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
@@ -727,9 +733,6 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
osp = (*bufp)->b_data;
- if (DSL_SCAN_IS_SCRUB_RESILVER(scn))
- dsl_scan_zil(dp, &osp->os_zil_header);
-
dsl_scan_visitdnode(scn, ds, osp->os_type,
&osp->os_meta_dnode, *bufp, DMU_META_DNODE_OBJECT, tx);
@@ -1072,9 +1075,23 @@ dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx)
{
dsl_pool_t *dp = scn->scn_dp;
dsl_dataset_t *ds;
+ objset_t *os;
VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
+ if (dmu_objset_from_ds(ds, &os))
+ goto out;
+
+ /*
+ * Only the ZIL in the head (non-snapshot) is valid. Even though
+ * snapshots can have ZIL block pointers (which may be the same
+ * BP as in the head), they must be ignored. So we traverse the
+ * ZIL here, rather than in scan_recurse(), because the regular
+ * snapshot block-sharing rules don't apply to it.
+ */
+ if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !dsl_dataset_is_snapshot(ds))
+ dsl_scan_zil(dp, &os->os_zil_header);
+
/*
* Iterate over the bps in this ds.
*/
@@ -1446,7 +1463,6 @@ dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx)
dsl_scan_setup_sync(scn, &func, tx);
}
-
if (!dsl_scan_active(scn) ||
spa_sync_pass(dp->dp_spa) > 1)
return;
@@ -1489,7 +1505,6 @@ dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx)
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
-
if (scn->scn_phys.scn_ddt_bookmark.ddb_class <=
scn->scn_phys.scn_ddt_class_max) {
zfs_dbgmsg("doing scan sync txg %llu; "
@@ -1644,8 +1659,9 @@ dsl_scan_scrub_cb(dsl_pool_t *dp,
spa_t *spa = dp->dp_spa;
uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp);
boolean_t needs_io;
- int zio_flags = ZIO_FLAG_SCRUB_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL;
+ int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL;
int zio_priority;
+ int scan_delay = 0;
if (phys_birth <= scn->scn_phys.scn_min_txg ||
phys_birth >= scn->scn_phys.scn_max_txg)
@@ -1658,10 +1674,12 @@ dsl_scan_scrub_cb(dsl_pool_t *dp,
zio_flags |= ZIO_FLAG_SCRUB;
zio_priority = ZIO_PRIORITY_SCRUB;
needs_io = B_TRUE;
+ scan_delay = zfs_scrub_delay;
} else if (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) {
zio_flags |= ZIO_FLAG_RESILVER;
zio_priority = ZIO_PRIORITY_RESILVER;
needs_io = B_FALSE;
+ scan_delay = zfs_resilver_delay;
}
/* If it's an intent log block, failure is expected. */
@@ -1699,14 +1717,23 @@ dsl_scan_scrub_cb(dsl_pool_t *dp,
}
if (needs_io && !zfs_no_scrub_io) {
+ vdev_t *rvd = spa->spa_root_vdev;
+ uint64_t maxinflight = rvd->vdev_children * zfs_top_maxinflight;
void *data = zio_data_buf_alloc(size);
mutex_enter(&spa->spa_scrub_lock);
- while (spa->spa_scrub_inflight >= spa->spa_scrub_maxinflight)
+ while (spa->spa_scrub_inflight >= maxinflight)
cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
spa->spa_scrub_inflight++;
mutex_exit(&spa->spa_scrub_lock);
+ /*
+ * If we're seeing recent (zfs_scan_idle) "important" I/Os
+ * then throttle our workload to limit the impact of a scan.
+ */
+ if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle)
+ delay(scan_delay);
+
zio_nowait(zio_read(NULL, spa, bp, data, size,
dsl_scan_scrub_done, NULL, zio_priority,
zio_flags, zb));