On Fri, 2017-01-13 at 14:54 -0800, Andrew Morton wrote: > On Fri, 13 Jan 2017 16:34:18 -0700 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. > > > > ... > > > > --- 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); > > (The poorly named) blk_queue_io_stat() actually returns a bool. This > is well concealed because blk_queue_io_stat() is unnecessarily > implemented as a macro (why oh why).
It was unclear to me what type I needed to use. test_bit() is 'bool' in arch/x86/include/asm/bitops.h but is 'int' in include/asm- generic/bitops/non-atomic.h. So, I used 'int' for safe... Thanks, -Toshi > > --- a/fs/dax.c~dax-enable-iostat-for-read-write-fix > +++ a/fs/dax.c > @@ -1085,7 +1085,7 @@ dax_iomap_rw(struct kiocb *iocb, struct > 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); > + bool do_acct = blk_queue_io_stat(disk->queue); > > if (iov_iter_rw(iter) == WRITE) > flags |= IOMAP_WRITE; > _ >
