On 2/4/22 8:03 AM, Milan Broz wrote: > > > On 04/02/2022 14:32, Jens Axboe wrote: >> On 2/4/22 2:22 AM, Milan Broz wrote: >>> Hi Jens, >>> >>> It seems that there is a regression in direct-io over loop for partial >>> direct-io reads (or perhaps even for other situations). >>> >>> If I run this code (loop over 6M file, dd direct-io read with 4M blocks) >>> >>> IMG=tst.img >>> LOOP=/dev/loop66 >>> >>> truncate -s 6M $IMG >>> losetup $LOOP $IMG >>> dd if=$LOOP of=/dev/null bs=4M iflag=direct >>> losetup -d $LOOP >>> >>> >>> on older kernel (<=5.16) it reads the whole file >>> 6291456 bytes (6.3 MB, 6.0 MiB) copied, 0.201591 s, 31.2 MB/s >>> >>> >>> while on 5.17-rc (tested on today/s Linus' git) it reads only the full blocks: >>> 4194304 bytes (4.2 MB, 4.0 MiB) copied, 0.201904 s, 20.8 MB/s >>> >>> No error reported, exit code is 0. >> >> Can you try: >> >> https://git.kernel.dk/cgit/linux-block/commit/?h=block-5.17&id=3e1f941dd9f33776b3df4e30f741fe445ff773f3 > > Yes, it works now. > (Not sure why I did not check if this patch is mainline, as I know > about it. My bad...) > > So this is going to some next rc, right? Yes, it'll be in -rc3, pushing it out today or tomorrow. -- Jens Axboe
