btrfs: don't call btrfs_page_set_checked in finish_compressed_bio_read

This flag was used to communicate that the low-level compression code
already did verify the checksum to the high-level I/O completion code.

But it has been unused for a long time as the upper btrfs_bio for the
decompressed data had a NULL csum pointer basically since that pointer
existed and the code already checks for that a little later.

Note that this does not affect the other use of the checked flag, which
is only used for the COW fixup worker.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -152,29 +152,9 @@ static void finish_compressed_bio_read(struct compressed_bio *cb)
 	}
 
 	/* Do io completion on the original bio */
-	if (cb->status != BLK_STS_OK) {
+	if (cb->status != BLK_STS_OK)
 		cb->orig_bio->bi_status = cb->status;
-		bio_endio(cb->orig_bio);
-	} else {
-		struct bio_vec *bvec;
-		struct bvec_iter_all iter_all;
-
-		/*
-		 * We have verified the checksum already, set page checked so
-		 * the end_io handlers know about it
-		 */
-		ASSERT(!bio_flagged(cb->orig_bio, BIO_CLONED));
-		bio_for_each_segment_all(bvec, cb->orig_bio, iter_all) {
-			u64 bvec_start = page_offset(bvec->bv_page) +
-					 bvec->bv_offset;
-
-			btrfs_page_set_checked(btrfs_sb(cb->inode->i_sb),
-					bvec->bv_page, bvec_start,
-					bvec->bv_len);
-		}
-
-		bio_endio(cb->orig_bio);
-	}
+	bio_endio(cb->orig_bio);
 
 	/* Finally free the cb struct */
 	kfree(cb->compressed_pages);

fs/btrfs/inode.c

@@ -3504,11 +3504,6 @@ unsigned int btrfs_verify_data_csum(struct btrfs_bio *bbio,
 	u32 pg_off;
 	unsigned int result = 0;
 
-	if (btrfs_page_test_checked(fs_info, page, start, end + 1 - start)) {
-		btrfs_page_clear_checked(fs_info, page, start, end + 1 - start);
-		return 0;
-	}
-
 	/*
 	 * This only happens for NODATASUM or compressed read.
 	 * Normally this should be covered by above check for compressed read