btrfs: make btrfs_verify_data_csum follow sector size (f44cf410) · Commits · 戴 / test

Currently btrfs_verify_data_csum() just passes the whole page to check_data_csum(), which is fine since we only support sectorsize == PAGE_SIZE. To support subpage, we need to properly honor per-sector checksum verification, just like what we did in dio read path. This patch will do the csum verification in a for loop, starts with pg_off == start - page_offset(page), with sectorsize increase for each loop. For sectorsize == PAGE_SIZE case, the pg_off will always be 0, and we will only loop once. For subpage case, we do the iterate over each sector and if we found any error, we return error. Reviewed-by:

Josef Bacik <josef@toxicpanda.com> Signed-off-by:

Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by:

Qu Wenruo <wqu@suse.com> Reviewed-by:

David Sterba <dsterba@suse.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

+15 −3

Original line number	Diff line number	Diff line
		@@ -2951,7 +2951,7 @@ void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
		* The length of such check is always one sector size.
		*/
		static int check_data_csum(struct inode inode, struct btrfs_io_bio io_bio,
		u32 bio_offset, struct page *page, int pgoff)
		u32 bio_offset, struct page *page, u32 pgoff)
		{
		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
		SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
		@@ -3002,10 +3002,11 @@ zeroit:
		int btrfs_verify_data_csum(struct btrfs_io_bio *io_bio, u32 bio_offset,
		struct page *page, u64 start, u64 end, int mirror)
		{
		size_t offset = start - page_offset(page);
		struct inode *inode = page->mapping->host;
		struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
		struct btrfs_root *root = BTRFS_I(inode)->root;
		const u32 sectorsize = root->fs_info->sectorsize;
		u32 pg_off;

		if (PageChecked(page)) {
		ClearPageChecked(page);
		@@ -3024,7 +3025,18 @@ int btrfs_verify_data_csum(struct btrfs_io_bio *io_bio, u32 bio_offset,
		return 0;
		}

		return check_data_csum(inode, io_bio, bio_offset, page, offset);
		ASSERT(page_offset(page) <= start &&
		end <= page_offset(page) + PAGE_SIZE - 1);
		for (pg_off = offset_in_page(start);
		pg_off < offset_in_page(end);
		pg_off += sectorsize, bio_offset += sectorsize) {
		int ret;

		ret = check_data_csum(inode, io_bio, bio_offset, page, pg_off);
		if (ret < 0)
		return -EIO;
		}
		return 0;
		}

		/*

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