+static void scrub_free_parity(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct scrub_page *curr, *next;
+ int nbits;
+
+ nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
+ if (nbits) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors += nbits;
+ sctx->stat.uncorrectable_errors += nbits;
+ spin_unlock(&sctx->stat_lock);
+ }
+
+ list_for_each_entry_safe(curr, next, &sparity->spages, list) {
+ list_del_init(&curr->list);
+ scrub_page_put(curr);
+ }
+
+ kfree(sparity);
+}
+
+static void scrub_parity_bio_endio(struct bio *bio, int error)
+{
+ struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
+ struct scrub_ctx *sctx = sparity->sctx;
+
+ if (error)
+ bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
+ sparity->nsectors);
+
+ scrub_free_parity(sparity);
+ scrub_pending_bio_dec(sctx);
+ bio_put(bio);
+}
+
+static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct bio *bio;
+ struct btrfs_raid_bio *rbio;
+ struct scrub_page *spage;
+ struct btrfs_bio *bbio = NULL;
+ u64 *raid_map = NULL;
+ u64 length;
+ int ret;
+
+ if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
+ sparity->nsectors))
+ goto out;
+
+ length = sparity->logic_end - sparity->logic_start + 1;
+ ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
+ sparity->logic_start,
+ &length, &bbio, 0, &raid_map);
+ if (ret || !bbio || !raid_map)
+ goto bbio_out;
+
+ bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
+ if (!bio)
+ goto bbio_out;
+
+ bio->bi_iter.bi_sector = sparity->logic_start >> 9;
+ bio->bi_private = sparity;
+ bio->bi_end_io = scrub_parity_bio_endio;
+
+ rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio,
+ raid_map, length,
+ sparity->scrub_dev,
+ sparity->dbitmap,
+ sparity->nsectors);
+ if (!rbio)
+ goto rbio_out;
+
+ list_for_each_entry(spage, &sparity->spages, list)
+ raid56_parity_add_scrub_pages(rbio, spage->page,
+ spage->logical);
+
+ scrub_pending_bio_inc(sctx);
+ raid56_parity_submit_scrub_rbio(rbio);
+ return;
+
+rbio_out:
+ bio_put(bio);
+bbio_out:
+ kfree(bbio);
+ kfree(raid_map);
+ bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
+ sparity->nsectors);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+out:
+ scrub_free_parity(sparity);
+}
+
+static inline int scrub_calc_parity_bitmap_len(int nsectors)
+{
+ return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * (BITS_PER_LONG / 8);
+}
+
+static void scrub_parity_get(struct scrub_parity *sparity)
+{
+ atomic_inc(&sparity->ref_count);
+}
+
+static void scrub_parity_put(struct scrub_parity *sparity)
+{
+ if (!atomic_dec_and_test(&sparity->ref_count))
+ return;
+
+ scrub_parity_check_and_repair(sparity);
+}
+
+static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
+ struct map_lookup *map,
+ struct btrfs_device *sdev,
+ struct btrfs_path *path,
+ u64 logic_start,
+ u64 logic_end)
+{
+ struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_root *csum_root = fs_info->csum_root;
+ struct btrfs_extent_item *extent;
+ u64 flags;
+ int ret;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ u64 generation;
+ u64 extent_logical;
+ u64 extent_physical;
+ u64 extent_len;
+ struct btrfs_device *extent_dev;
+ struct scrub_parity *sparity;
+ int nsectors;
+ int bitmap_len;
+ int extent_mirror_num;
+ int stop_loop = 0;
+
+ nsectors = map->stripe_len / root->sectorsize;
+ bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
+ sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
+ GFP_NOFS);
+ if (!sparity) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ sparity->stripe_len = map->stripe_len;
+ sparity->nsectors = nsectors;
+ sparity->sctx = sctx;
+ sparity->scrub_dev = sdev;
+ sparity->logic_start = logic_start;
+ sparity->logic_end = logic_end;
+ atomic_set(&sparity->ref_count, 1);
+ INIT_LIST_HEAD(&sparity->spages);
+ sparity->dbitmap = sparity->bitmap;
+ sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
+
+ ret = 0;
+ while (logic_start < logic_end) {
+ if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.objectid = logic_start;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = btrfs_previous_extent_item(root, path, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &key,
+ path, 0, 0);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+ stop_loop = 0;
+ while (1) {
+ u64 bytes;
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto out;
+
+ stop_loop = 1;
+ break;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ bytes = root->nodesize;
+ else
+ bytes = key.offset;
+
+ if (key.objectid + bytes <= logic_start)
+ goto next;
+
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY)
+ goto next;
+
+ if (key.objectid > logic_end) {
+ stop_loop = 1;
+ break;
+ }
+
+ while (key.objectid >= logic_start + map->stripe_len)
+ logic_start += map->stripe_len;
+
+ extent = btrfs_item_ptr(l, slot,
+ struct btrfs_extent_item);
+ flags = btrfs_extent_flags(l, extent);
+ generation = btrfs_extent_generation(l, extent);
+
+ if (key.objectid < logic_start &&
+ (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
+ btrfs_err(fs_info,
+ "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
+ key.objectid, logic_start);
+ goto next;
+ }
+again:
+ extent_logical = key.objectid;
+ extent_len = bytes;
+
+ if (extent_logical < logic_start) {
+ extent_len -= logic_start - extent_logical;
+ extent_logical = logic_start;
+ }
+
+ if (extent_logical + extent_len >
+ logic_start + map->stripe_len)
+ extent_len = logic_start + map->stripe_len -
+ extent_logical;
+
+ scrub_parity_mark_sectors_data(sparity, extent_logical,
+ extent_len);
+
+ scrub_remap_extent(fs_info, extent_logical,
+ extent_len, &extent_physical,
+ &extent_dev,
+ &extent_mirror_num);
+
+ ret = btrfs_lookup_csums_range(csum_root,
+ extent_logical,
+ extent_logical + extent_len - 1,
+ &sctx->csum_list, 1);
+ if (ret)
+ goto out;
+
+ ret = scrub_extent_for_parity(sparity, extent_logical,
+ extent_len,
+ extent_physical,
+ extent_dev, flags,
+ generation,
+ extent_mirror_num);
+ if (ret)
+ goto out;
+
+ scrub_free_csums(sctx);
+ if (extent_logical + extent_len <
+ key.objectid + bytes) {
+ logic_start += map->stripe_len;
+
+ if (logic_start >= logic_end) {
+ stop_loop = 1;
+ break;
+ }
+
+ if (logic_start < key.objectid + bytes) {
+ cond_resched();
+ goto again;
+ }
+ }
+next:
+ path->slots[0]++;
+ }
+
+ btrfs_release_path(path);
+
+ if (stop_loop)
+ break;
+
+ logic_start += map->stripe_len;
+ }
+out:
+ if (ret < 0)
+ scrub_parity_mark_sectors_error(sparity, logic_start,
+ logic_end - logic_start + 1);
+ scrub_parity_put(sparity);
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_ctx.wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_ctx.wr_lock);
+
+ btrfs_release_path(path);
+ return ret < 0 ? ret : 0;
+}
+