diff options
| author | Brian Behlendorf <[email protected]> | 2018-01-31 09:33:33 -0800 |
|---|---|---|
| committer | GitHub <[email protected]> | 2018-01-31 09:33:33 -0800 |
| commit | f90a30ad1b32a971f62a540f8944e42f99b254ce (patch) | |
| tree | be89a5aeb59e7bc3161842adc899a0f13d4ee310 /module/zfs | |
| parent | 1d8a71b603769214a73bc9720107c4bd97206bff (diff) | |
Fix txg_sync_thread hang in scan_exec_io()
When scn->scn_maxinflight_bytes has not been initialized it's
possible to hang on the condition variable in scan_exec_io().
This issue was uncovered by ztest and is only possible when
deduplication is enabled through the following call path.
txg_sync_thread()
spa_sync()
ddt_sync_table()
ddt_sync_entry()
dsl_scan_ddt_entry()
dsl_scan_scrub_cb()
dsl_scan_enqueuei()
scan_exec_io()
cv_wait()
Resolve the issue by always initializing scn_maxinflight_bytes
to a reasonable minimum value. This value will be recalculated
in dsl_scan_sync() to pick up changes to zfs_scan_vdev_limit
and the addition/removal of vdevs.
Reviewed-by: Tom Caputi <[email protected]>
Reviewed by: George Melikov <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #7098
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/dsl_scan.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c index 4b4f1665c..fc0c24e1c 100644 --- a/module/zfs/dsl_scan.c +++ b/module/zfs/dsl_scan.c @@ -124,6 +124,7 @@ static boolean_t scan_ds_queue_contains(dsl_scan_t *scn, uint64_t dsobj, static void scan_ds_queue_insert(dsl_scan_t *scn, uint64_t dsobj, uint64_t txg); static void scan_ds_queue_remove(dsl_scan_t *scn, uint64_t dsobj); static void scan_ds_queue_sync(dsl_scan_t *scn, dmu_tx_t *tx); +static uint64_t dsl_scan_count_leaves(vdev_t *vd); extern int zfs_vdev_async_write_active_min_dirty_percent; @@ -378,6 +379,14 @@ dsl_scan_init(dsl_pool_t *dp, uint64_t txg) scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY); + /* + * Calculate the max number of in-flight bytes for pool-wide + * scanning operations (minimum 1MB). Limits for the issuing + * phase are done per top-level vdev and are handled separately. + */ + scn->scn_maxinflight_bytes = MAX(zfs_scan_vdev_limit * + dsl_scan_count_leaves(spa->spa_root_vdev), 1ULL << 20); + bcopy(&scn->scn_phys, &scn->scn_phys_cached, sizeof (scn->scn_phys)); avl_create(&scn->scn_queue, scan_ds_queue_compare, sizeof (scan_ds_t), offsetof(scan_ds_t, sds_node)); @@ -2290,7 +2299,7 @@ dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, zbookmark_phys_t zb = { 0 }; int p; - if (scn->scn_phys.scn_state != DSS_SCANNING) + if (!dsl_scan_is_running(scn)) return; for (p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { @@ -3207,7 +3216,7 @@ dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) uint64_t nr_leaves = dsl_scan_count_leaves(spa->spa_root_vdev); /* - * Calculate the max number of in-flight bytes for pool-wide + * Recalculate the max number of in-flight bytes for pool-wide * scanning operations (minimum 1MB). Limits for the issuing * phase are done per top-level vdev and are handled separately. */ @@ -3564,6 +3573,8 @@ scan_exec_io(dsl_pool_t *dp, const blkptr_t *bp, int zio_flags, size_t size = BP_GET_PSIZE(bp); abd_t *data = abd_alloc_for_io(size, B_FALSE); + ASSERT3U(scn->scn_maxinflight_bytes, >, 0); + if (queue == NULL) { mutex_enter(&spa->spa_scrub_lock); while (spa->spa_scrub_inflight >= scn->scn_maxinflight_bytes) |