On Thu, Apr 06, 2017 at 02:21:56PM +0200, Hannes Reinecke wrote: > On 04/06/2017 02:03 PM, Ming Lei wrote: > > On Thu, Apr 06, 2017 at 04:43:18PM +0800, Ming Lei wrote: > >> On Thu, Apr 06, 2017 at 01:19:45AM -0700, Omar Sandoval wrote: > >>> From: Omar Sandoval <osandov@xxxxxx> > >>> > >>> The request queue created when we create a loop device has the default > >>> logical block size of 512. When we associate the device with an fd, we > >>> set the block size on the block_device but don't update the logical > >>> block size of the request_queue. This makes it impossibe to use direct > >>> I/O with a backing file on a device with a block size >512, as the > >>> following check in __loop_update_dio() fails: > >>> > >>> sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); > >>> if (queue_logical_block_size(lo->lo_queue) >= sb_bsize && > >>> ... > >>> > >>> Fix it by updating the logical block size when we set the fd. > >>> > >>> Signed-off-by: Omar Sandoval <osandov@xxxxxx> > >>> --- > >>> drivers/block/loop.c | 1 + > >>> 1 file changed, 1 insertion(+) > >>> > >>> diff --git a/drivers/block/loop.c b/drivers/block/loop.c > >>> index cc981f34e017..1bb22903ad1a 100644 > >>> --- a/drivers/block/loop.c > >>> +++ b/drivers/block/loop.c > >>> @@ -941,6 +941,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, > >>> /* let user-space know about the new size */ > >>> kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); > >>> > >>> + blk_queue_logical_block_size(lo->lo_queue, lo_blocksize); > >>> set_blocksize(bdev, lo_blocksize); > >>> > >>> lo->lo_state = Lo_bound; > >> > >> Looks fine! > >> > >> Reviewed-by: Ming Lei <minlei@xxxxxxxxxx> > > > > Turns out I am wrong, and we can't change logical block size in this way > > because we need to support 512 byte sector filesystem image on backing > > device with bigger sector size. > > > > And we don't support dio in this situation yet, but Hannes Reinecke's > > patch might help this case. So I have to recall the reviewed-by. > > > Yes, please! > > I've been waiting for it far too long. > Should I repost them? Looks your last post can't be applied any more, so please post a new version. Thanks, Ming
