On Wed, Dec 23 2020 at 6:26am -0500, Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx> wrote: > So that kiocb.ki_cookie can be defined as blk_qc_t, which will enforce > the encapsulation. > > Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx> > --- > include/linux/blk_types.h | 2 +- > include/linux/fs.h | 2 +- > include/linux/types.h | 3 +++ > 3 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index 866f74261b3b..2e05244fc16d 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -532,7 +532,7 @@ static inline int op_stat_group(unsigned int op) > return op_is_write(op); > } > > -typedef unsigned int blk_qc_t; > +/* Macros for blk_qc_t */ > #define BLK_QC_T_NONE -1U > #define BLK_QC_T_SHIFT 16 > #define BLK_QC_T_INTERNAL (1U << 31) > diff --git a/include/linux/fs.h b/include/linux/fs.h > index ad4cf1bae586..58db714c4834 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -330,7 +330,7 @@ struct kiocb { > u16 ki_hint; > u16 ki_ioprio; /* See linux/ioprio.h */ > union { > - unsigned int ki_cookie; /* for ->iopoll */ > + blk_qc_t ki_cookie; /* for ->iopoll */ > struct wait_page_queue *ki_waitq; /* for async buffered IO */ > }; > > diff --git a/include/linux/types.h b/include/linux/types.h > index a147977602b5..da5ca7e1bea9 100644 > --- a/include/linux/types.h > +++ b/include/linux/types.h > @@ -125,6 +125,9 @@ typedef s64 int64_t; > typedef u64 sector_t; > typedef u64 blkcnt_t; > > +/* cookie used for IO polling */ > +typedef unsigned int blk_qc_t; > + > /* > * The type of an index into the pagecache. > */ > -- > 2.27.0 > Unfortunate that you cannot just include blk_types.h in fs.h; but vma_is_dax() ruins that for us since commit baabda2614245 ("mm: always enable thp for dax mappings"). Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>