On Mon, Apr 21, 2025 at 7:07 PM Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx> wrote:
>
>
>
> On 4/19/25 5:06 AM, Joanne Koong wrote:
> > Use a bitfield for tracking initialized, blocked, aborted, and io_uring
> > state of the fuse connection. Track connected state using a bool instead
> > of an unsigned.
> >
> > On a 64-bit system, this shaves off 16 bytes from the size of struct
> > fuse_conn.
> >
> > No functional changes.
> >
> > Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
> > ---
> > fs/fuse/fuse_i.h | 24 ++++++++++++------------
> > 1 file changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> > index b54f4f57789f..6aecada8aadd 100644
> > --- a/fs/fuse/fuse_i.h
> > +++ b/fs/fuse/fuse_i.h
> > @@ -690,24 +690,24 @@ struct fuse_conn {
> > * active_background, bg_queue, blocked */
> > spinlock_t bg_lock;
> >
> > - /** Flag indicating that INIT reply has been received. Allocating
> > - * any fuse request will be suspended until the flag is set */
> > - int initialized;
> > -
> > - /** Flag indicating if connection is blocked. This will be
> > - the case before the INIT reply is received, and if there
> > - are too many outstading backgrounds requests */
> > - int blocked;
> > -
> > /** waitq for blocked connection */
> > wait_queue_head_t blocked_waitq;
> >
> > /** Connection established, cleared on umount, connection
> > abort and device release */
> > - unsigned connected;
> > + bool connected;
>
> Why not also convert connected to bitfield?
fuse_drop_waiting() checks the connected state locklessly through
READ_ONCE(fc->connected). The smallest size READ_ONCE supports is a
byte, I don't think it works on bitfields.
Thanks,
Joanne
>
>
> --
> Thanks,
> Jingbo
