On Wed, Jan 20, 2021 at 08:19:14AM +0800, Qu Wenruo wrote: > > > On 2021/1/20 上午12:06, David Sterba wrote: > > On Tue, Jan 19, 2021 at 04:51:45PM +0100, David Sterba wrote: > >> On Tue, Jan 19, 2021 at 06:54:28AM +0800, Qu Wenruo wrote: > >>> On 2021/1/19 上午6:46, David Sterba wrote: > >>>> On Sat, Jan 16, 2021 at 03:15:18PM +0800, Qu Wenruo wrote: > >>>>> + return; > >>>>> + > >>>>> + subpage = (struct btrfs_subpage *)detach_page_private(page); > >>>>> + ASSERT(subpage); > >>>>> + kfree(subpage); > >>>>> +} > >>>>> diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h > >>>>> new file mode 100644 > >>>>> index 000000000000..96f3b226913e > >>>>> --- /dev/null > >>>>> +++ b/fs/btrfs/subpage.h > >>>>> @@ -0,0 +1,31 @@ > >>>>> +/* SPDX-License-Identifier: GPL-2.0 */ > >>>>> + > >>>>> +#ifndef BTRFS_SUBPAGE_H > >>>>> +#define BTRFS_SUBPAGE_H > >>>>> + > >>>>> +#include <linux/spinlock.h> > >>>>> +#include "ctree.h" > >>>> > >>>> So subpage.h would pull the whole ctree.h, that's not very nice. If > >>>> anything, the .c could include ctree.h because there are lots of the > >>>> common structure and function definitions, but not the .h. This creates > >>>> unnecessary include dependencies. > >>>> > >>>> Any pointer type you'd need in structures could be forward declared. > >>> > >>> Unfortunately, the main needed pointer is fs_info, and we're accessing > >>> it pretty frequently (mostly for sector/node size). > >>> > >>> I don't believe forward declaration would help in this case. > >> > >> I've looked at the final subpage.h and you add way too many static > >> inlines that don't seem to be necessary for the reasons the static > >> inlines are supposed to be used. > > > > The only file that includes subpage.h is extent_io.c, so as long as it > > stays like that it's manageable. But untangling the include hell still > > needs to hapen some day and new code that makes it harder worries me. > > > If going through the github branch, you will see there are more files > using subpage.h: > - extent_io.c > - disk-io.c > - file.c > - inode.c > - reflink.c > - relocation.c > > And furthermore, about the static inline abuse, the part really need > that static inline is the check against regular sector size, and > unfortunately, most outside callers need such check. > > I can put the pure subpage callers into subpage.c, but the generic > helpers handling both cases still need that.
I had a look and this is too much. Just by counting 'static inline' (wher it's also part of the btrfs_page_clamp_* helpers) it's 30 and not all the functions are short enough for static inlines. Please make them all regular functions and put them to subpage.c and don't include ctree.h.
