Introduce new function, scrub_one_data_stripe(), to check all data and tree blocks inside the data stripe.
This function will not try to recovery any error, but only check if any data/tree blocks has mismatch csum. If data missing csum, which is completely valid for case like nodatasum, it will just record it, but not report as error. Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> --- scrub.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) diff --git a/scrub.c b/scrub.c index 4302aafa..1944f216 100644 --- a/scrub.c +++ b/scrub.c @@ -627,3 +627,132 @@ invalid_arg: error("invalid parameter for %s", __func__); return -EINVAL; } + +/* + * Scrub one full data stripe of RAID5/6. + * This means it will check any data/metadata extent in the data stripe + * spcified by @stripe and @stripe_len + * + * This function will only *CHECK* if the data stripe has any corruption. + * Won't repair at this function. + * + * Return 0 if the full stripe is OK. + * Return <0 if any error is found. + * Note: Missing csum is not counted as error(NODATACSUM is valid) + */ +static int scrub_one_data_stripe(struct btrfs_fs_info *fs_info, + struct btrfs_scrub_progress *scrub_ctx, + struct scrub_stripe *stripe, u32 stripe_len) +{ + struct btrfs_path *path; + struct btrfs_root *extent_root = fs_info->extent_root; + struct btrfs_key key; + u64 extent_start; + u64 extent_len; + u64 orig_csum_discards; + int ret; + + if (!is_data_stripe(stripe)) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = stripe->logical + stripe_len; + key.offset = 0; + key.type = 0; + + ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + while (1) { + struct btrfs_extent_item *ei; + struct extent_buffer *eb; + char *data; + int slot; + int metadata = 0; + u64 check_start; + u64 check_len; + + ret = btrfs_previous_extent_item(extent_root, path, 0); + if (ret > 0) { + ret = 0; + goto out; + } + if (ret < 0) + goto out; + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &key, slot); + extent_start = key.objectid; + ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item); + + /* tree block scrub */ + if (key.type == BTRFS_METADATA_ITEM_KEY || + btrfs_extent_flags(eb, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + extent_len = extent_root->nodesize; + metadata = 1; + } else { + extent_len = key.offset; + metadata = 0; + } + + /* Current extent is out of our range, loop comes to end */ + if (extent_start + extent_len <= stripe->logical) + break; + + if (metadata) { + /* + * Check crossing stripe first, which can't be scrubbed + */ + if (check_crossing_stripes(fs_info, extent_start, + extent_root->nodesize)) { + error("tree block at %llu is crossing stripe boundary, unable to scrub", + extent_start); + ret = -EIO; + goto out; + } + data = stripe->data + extent_start - stripe->logical; + ret = check_tree_mirror(fs_info, scrub_ctx, + data, extent_start, 0); + /* Any csum/verify error means the stripe is screwed */ + if (ret < 0) { + stripe->csum_mismatch = 1; + ret = -EIO; + goto out; + } + ret = 0; + continue; + } + /* Restrict the extent range to fit stripe range */ + check_start = max(extent_start, stripe->logical); + check_len = min(extent_start + extent_len, stripe->logical + + stripe_len) - check_start; + + /* Record original csum_discards to detect missing csum case */ + orig_csum_discards = scrub_ctx->csum_discards; + + data = stripe->data + check_start - stripe->logical; + ret = check_data_mirror(fs_info, scrub_ctx, data, check_start, + check_len, 0, NULL); + /* Csum mismatch, no need to continue anyway*/ + if (ret < 0) { + stripe->csum_mismatch = 1; + goto out; + } + /* Check if there is any missing csum for data */ + if (scrub_ctx->csum_discards != orig_csum_discards) + stripe->csum_missing = 1; + /* + * Only increase data_extents_scrubbed if we are scrubbing the + * tailing part of the data extent + */ + if (extent_start + extent_len <= stripe->logical + stripe_len) + scrub_ctx->data_extents_scrubbed++; + ret = 0; + } +out: + btrfs_free_path(path); + return ret; +} -- 2.13.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html