Btrfs: While doing checksums on bios, cache the extent_buffer mapping (6e92f5e6) · Commits · e / devices / android_kernel_xiaomi_sm6125

fs/btrfs/file-item.c

+33 −3

Original line number	Diff line number	Diff line
		@@ -156,6 +156,11 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
		int bio_index = 0;
		struct bio_vec *bvec = bio->bi_io_vec;
		char *data;
		char *eb_map;
		char *eb_token;
		unsigned long map_len;
		unsigned long map_start;


		path = btrfs_alloc_path();
		BUG_ON(!path);
		@@ -272,6 +277,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
		item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
		item_end = (struct btrfs_csum_item )((unsigned char )item_end +
		btrfs_item_size_nr(leaf, path->slots[0]));
		eb_token = NULL;
		next_bvec:
		data = kmap_atomic(bvec->bv_page, KM_IRQ0);
		csum_result = ~(u32)0;
		@@ -283,15 +289,39 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
		printk("csum result is 0 for inode %lu offset %Lu\n", inode->i_ino, offset);
		}

		if (!eb_token \|\|
		(unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) {
		int err;

		if (eb_token)
		unmap_extent_buffer(leaf, eb_token, KM_IRQ1);
		eb_token = NULL;
		err = map_private_extent_buffer(leaf, (unsigned long)item,
		BTRFS_CRC32_SIZE,
		&eb_token, &eb_map,
		&map_start, &map_len, KM_IRQ1);
		if (err)
		eb_token = NULL;
		}
		if (eb_token) {
		memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
		&csum_result, BTRFS_CRC32_SIZE);
		} else {
		write_extent_buffer(leaf, &csum_result, (unsigned long)item,
		BTRFS_CRC32_SIZE);
		}
		bio_index++;
		bvec++;
		if (bio_index < bio->bi_vcnt) {
		item = (struct btrfs_csum_item )((char )item + BTRFS_CRC32_SIZE);
		item = (struct btrfs_csum_item )((char )item +
		BTRFS_CRC32_SIZE);
		if (item < item_end)
		goto next_bvec;
		}
		if (eb_token) {
		unmap_extent_buffer(leaf, eb_token, KM_IRQ1);
		eb_token = NULL;
		}
		btrfs_mark_buffer_dirty(path->nodes[0]);
		if (bio_index < bio->bi_vcnt) {
		btrfs_release_path(root, path);