This is for the legacy floppy and ataflop drivers that currently abuse ->errors for this purpose. It's stashed away in a union to not grow the struct size, the other fields are either used by modern drivers for different purposes or the I/O scheduler before queing the I/O to drivers. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a03acd92ae74..fa75401ea5cc 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -175,6 +175,7 @@ struct request { struct rb_node rb_node; /* sort/lookup */ struct bio_vec special_vec; void *completion_data; + int error_count; /* for legacy drivers, don't use */ }; /* -- 2.11.0