| Message ID | 20170418155229.5977-18-hch@bombadil.infradead.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Tue, 2017-04-18 at 08:52 -0700, Christoph Hellwig wrote: > From: Christoph Hellwig <hch@lst.de> > > 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@lst.de> > --- > include/linux/blkdev.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index 5986e1250d7d..e618164462e8 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 */ > }; > > /* Hello Christoph, Both blk-mq and the traditional block layer support a .cmd_size field to make the block layer core allocate driver-specific data at the end of struct request. Could that mechanism have been used for the error_count field? Thanks, Bart.
On Tue, Apr 18, 2017 at 10:57:11PM +0000, Bart Van Assche wrote: > Both blk-mq and the traditional block layer support a .cmd_size field to > make the block layer core allocate driver-specific data at the end of struct > request. Could that mechanism have been used for the error_count field? It could, and that's what I did for the modern drivers. It would have been a bit of a pain for these old floppy drivers, though.
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5986e1250d7d..e618164462e8 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 */ }; /*