diff options
Diffstat (limited to 'module/zfs/vdev_draid.c')
| -rw-r--r-- | module/zfs/vdev_draid.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/module/zfs/vdev_draid.c b/module/zfs/vdev_draid.c index b8f82d52e..2d83c1ac9 100644 --- a/module/zfs/vdev_draid.c +++ b/module/zfs/vdev_draid.c @@ -842,6 +842,53 @@ vdev_draid_map_alloc_empty(zio_t *zio, raidz_row_t *rr) } /* + * Verify that all empty sectors are zero filled before using them to + * calculate parity. Otherwise, silent corruption in an empty sector will + * result in bad parity being generated. That bad parity will then be + * considered authoritative and overwrite the good parity on disk. This + * is possible because the checksum is only calculated over the data, + * thus it cannot be used to detect damage in empty sectors. + */ +int +vdev_draid_map_verify_empty(zio_t *zio, raidz_row_t *rr) +{ + uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; + uint64_t parity_size = rr->rr_col[0].rc_size; + uint64_t skip_off = parity_size - skip_size; + uint64_t empty_off = 0; + int ret = 0; + + ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); + ASSERT3P(rr->rr_abd_empty, !=, NULL); + ASSERT3U(rr->rr_bigcols, >, 0); + + void *zero_buf = kmem_zalloc(skip_size, KM_SLEEP); + + for (int c = rr->rr_bigcols; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + + ASSERT3P(rc->rc_abd, !=, NULL); + ASSERT3U(rc->rc_size, ==, parity_size); + + if (abd_cmp_buf_off(rc->rc_abd, zero_buf, skip_off, + skip_size) != 0) { + vdev_raidz_checksum_error(zio, rc, rc->rc_abd); + abd_zero_off(rc->rc_abd, skip_off, skip_size); + rc->rc_error = SET_ERROR(ECKSUM); + ret++; + } + + empty_off += skip_size; + } + + ASSERT3U(empty_off, ==, abd_get_size(rr->rr_abd_empty)); + + kmem_free(zero_buf, skip_size); + + return (ret); +} + +/* * Given a logical address within a dRAID configuration, return the physical * address on the first drive in the group that this address maps to * (at position 'start' in permutation number 'perm'). |