On Thu, 2017-01-12 at 10:02 -0800, Joe Perches wrote:
> On Thu, 2017-01-12 at 11:38 -0700, Toshi Kani 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.
>
> []
> > diff --git a/fs/dax.c b/fs/dax.c
>
> []
> > @@ -1058,12 +1058,24 @@ dax_iomap_rw(struct kiocb *iocb, struct
> > iov_iter *iter,
> > {
> > struct address_space *mapping = iocb->ki_filp->f_mapping;
> > struct inode *inode = mapping->host;
> > + struct gendisk *disk = inode->i_sb->s_bdev->bd_disk;
> > loff_t pos = iocb->ki_pos, ret = 0, done = 0;
> > unsigned flags = 0;
> > + unsigned long start = 0;
> > + int do_acct = blk_queue_io_stat(disk->queue);
> >
> > if (iov_iter_rw(iter) == WRITE)
> > flags |= IOMAP_WRITE;
> >
> > + if (do_acct) {
> > + sector_t sec = iov_iter_count(iter) >> 9;
> > +
> > + start = jiffies;
> > + generic_start_io_acct(iov_iter_rw(iter),
> > + min_t(unsigned long, 1,
> > sec),
>
> I believe I mislead you with a thinko.
>
> Your original code was
> (!sec) ? 1 : sec
> and I suggested incorrectly using min_t
>
> It should of course be max_t. Sorry.
My bad. I should have caught it.
> Also, as sec is now sector_t (u64), perhaps this
> unsigned long cast is incorrect.
I see. Since iov_iter_count() returns a size_t value, I will use
'size_t' for 'sec' as you originally suggested.
Thanks,
-Toshi
