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. Sorry for the noise, :-( Thanks, Ming
