On Fri, Oct 14, 2016 at 10:25 AM, Toshi Kani <[email protected]> wrote: > DAX IO path does not support iostat, but its metadata IO path does. > Therefore, iostat shows metadata IO statistics only, which has been > confusing to users. > > Add iostat support to the DAX read/write path. > > Note, iostat still does not support the DAX mmap path as it allows > user applications to access directly. > > Signed-off-by: Toshi Kani <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Alexander Viro <[email protected]> > Cc: Dan Williams <[email protected]> > Cc: Ross Zwisler <[email protected]> > --- > fs/dax.c | 37 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 37 insertions(+) > > diff --git a/fs/dax.c b/fs/dax.c > index 014defd..3aaaac2 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -144,6 +144,34 @@ static sector_t to_sector(const struct buffer_head *bh, > return sector; > } > > +static void dax_iostat_start(struct gendisk *disk, struct iov_iter *iter, > + unsigned long *start) > +{ > + int rw = iov_iter_rw(iter); > + int sec = iov_iter_count(iter) >> 9;
Should this be a minimum of one sector since we allow unaligned transfers through this interface? ...or is iov_iter_count() somehow guaranteed to be sector aligned here?
