Introduce a new function, scrub_one_extent(), as a wrapper to check one mirror-based extent.
It will accept a btrfs_path parameter @path, which must points to a META/EXTENT_ITEM. And @start, @len, which must be a subset of META/EXTENT_ITEM. Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> --- scrub.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 147 insertions(+), 1 deletion(-) diff --git a/scrub.c b/scrub.c index e473d168..4302aafa 100644 --- a/scrub.c +++ b/scrub.c @@ -441,7 +441,7 @@ static int recover_data_mirror(struct btrfs_fs_info *fs_info, num_copies = btrfs_num_copies(&fs_info->mapping_tree, start, len); for (i = 0; i < num_copies; i++) { - for_each_set_bit(bit, corrupt_bitmaps[i], BITS_PER_LONG) { + for_each_set_bit(bit, corrupt_bitmaps[i], len / sectorsize) { u64 cur = start + bit * sectorsize; int good; @@ -481,3 +481,149 @@ out: free(buf); return ret; } + +/* Btrfs only supports up to 2 copies of data, yet */ +#define BTRFS_MAX_COPIES 2 + +/* + * Check all copies of range @start, @len. + * Caller must ensure the range is covered by EXTENT_ITEM/METADATA_ITEM + * specified by leaf of @path. + * And @start, @len must be a subset of the EXTENT_ITEM/METADATA_ITEM. + * + * Return 0 if the range is all OK or recovered or recoverable. + * Return <0 if the range can't be recoverable. + */ +static int scrub_one_extent(struct btrfs_fs_info *fs_info, + struct btrfs_scrub_progress *scrub_ctx, + struct btrfs_path *path, u64 start, u64 len, + int write) +{ + struct btrfs_key key; + struct btrfs_extent_item *ei; + struct extent_buffer *leaf = path->nodes[0]; + u32 sectorsize = fs_info->tree_root->sectorsize; + unsigned long *corrupt_bitmaps[BTRFS_MAX_COPIES] = { NULL }; + int slot = path->slots[0]; + int num_copies; + int meta_corrupted = 0; + int meta_good_mirror = 0; + int data_bad_mirror = 0; + u64 extent_start; + u64 extent_len; + int metadata = 0; + int i; + int ret = 0; + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.type != BTRFS_METADATA_ITEM_KEY && + key.type != BTRFS_EXTENT_ITEM_KEY) + goto invalid_arg; + + extent_start = key.objectid; + if (key.type == BTRFS_METADATA_ITEM_KEY) { + extent_len = fs_info->tree_root->nodesize; + metadata = 1; + } else { + extent_len = key.offset; + ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); + if (btrfs_extent_flags(leaf, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK) + metadata = 1; + } + if (start >= extent_start + extent_len || + start + len <= extent_start) + goto invalid_arg; + + for (i = 0; i < BTRFS_MAX_COPIES; i++) { + corrupt_bitmaps[i] = malloc( + calculate_bitmap_len(len / sectorsize)); + if (!corrupt_bitmaps[i]) + goto out; + } + num_copies = btrfs_num_copies(&fs_info->mapping_tree, start, len); + for (i = 1; i <= num_copies; i++) { + if (metadata) { + ret = check_tree_mirror(fs_info, scrub_ctx, + NULL, extent_start, i); + scrub_ctx->tree_extents_scrubbed++; + if (ret < 0) + meta_corrupted++; + else + meta_good_mirror = i; + } else { + ret = check_data_mirror(fs_info, scrub_ctx, NULL, start, + len, i, corrupt_bitmaps[i - 1]); + scrub_ctx->data_extents_scrubbed++; + } + } + + /* Metadata recover and report */ + if (metadata) { + if (!meta_corrupted) { + goto out; + } else if (meta_corrupted && meta_corrupted < num_copies) { + if (write) { + ret = recover_tree_mirror(fs_info, scrub_ctx, + start, meta_good_mirror); + if (ret < 0) { + error("failed to recover tree block at bytenr %llu", + start); + goto out; + } + printf("extent %llu len %llu REPAIRED: has corrupted mirror, repaired\n", + start, len); + goto out; + } + printf("extent %llu len %llu RECOVERABLE: has corrupted mirror, but is recoverable\n", + start, len); + goto out; + } else { + error("extent %llu len %llu CORRUPTED: all mirror(s) corrupted, can't be recovered", + start, len); + ret = -EIO; + goto out; + } + } + /* Data recover and report */ + for (i = 0; i < num_copies; i++) { + if (find_first_bit(corrupt_bitmaps[i], len / sectorsize) >= + len / sectorsize) + continue; + data_bad_mirror = i + 1; + } + /* All data sectors are good */ + if (!data_bad_mirror) { + ret = 0; + goto out; + } + + if (check_data_mirror_recoverable(fs_info, start, len, + sectorsize, corrupt_bitmaps)) { + if (write) { + ret = recover_data_mirror(fs_info, scrub_ctx, start, + len, corrupt_bitmaps); + if (ret < 0) { + error("failed to recover data extent at bytenr %llu len %llu", + start, len); + goto out; + } + printf("extent %llu len %llu REPARIED: has corrupted mirror, repaired\n", + start, len); + goto out; + } + printf("extent %llu len %llu RECOVERABLE: has corrupted mirror, recoverable\n", + start, len); + goto out; + } + error("extent %llu len %llu CORRUPTED, all mirror(s) corrupted, can't be repaired", + start, len); + ret = -EIO; +out: + for (i = 0; i < BTRFS_MAX_COPIES; i++) + kfree(corrupt_bitmaps[i]); + return ret; + +invalid_arg: + error("invalid parameter for %s", __func__); + return -EINVAL; +} -- 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