Re: [PATCH v2 2/2] md: fix sync_action incorrect display during resync

[Zheng Qixing]

Hi,


在 2025/8/12 17:22, Paul Menzel 写道:
> Dear Zheng,
>
>
> Thank you for your patch.
>
> Am 12.08.25 um 04:17 schrieb Zheng Qixing:
> > From: Zheng Qixing <zhengqixing@xxxxxxxxxx>
> >
> > During raid resync, if a disk becomes faulty, the operation is
> > briefly interrupted. The MD_RECOVERY_RECOVER flag triggered by
> > the disk failure causes sync_action to incorrectly show "recover"
> > instead of "resync". The same issue affects reshape operations.
> >
> > Reproduction steps:
> >    mdadm -Cv /dev/md1 -l1 -n4 -e1.2 /dev/sd{a..d} // -> resync happended
> >    mdadm -f /dev/md1 /dev/sda                     // -> resync 
> > interrupted
> >    cat sync_action
> >    -> recover
> >
> > Add progress checks in md_sync_action() for resync/recover/reshape
> > to ensure the interface correctly reports the actual operation type.
> >
> > Fixes: 4b10a3bc67c1 ("md: ensure resync is prioritized over recovery")
> > Signed-off-by: Zheng Qixing <zhengqixing@xxxxxxxxxx>
> > ---
> >   drivers/md/md.c | 38 ++++++++++++++++++++++++++++++++++++--
> >   1 file changed, 36 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c
> > index 4ea956a80343..798428d0870b 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -4845,9 +4845,34 @@ static bool rdev_needs_recovery(struct md_rdev 
> > *rdev, sector_t sectors)
> >       return false;
> >   }
> >   +static enum sync_action md_get_active_sync_action(struct mddev 
> > *mddev)
> > +{
> > +    struct md_rdev *rdev;
> > +    bool is_recover = false;
>
> `is_recover` sounds strange to me, but I am not an expert with the 
> code. Maybe `needs_recovery`?


is_recover is used here to distinguish whether the current sync_action 
is a recover, rather than a resync or reshape.

But it's not a big deal, no need to focus on it :)


> > +
> > +    if (mddev->resync_offset < MaxSector)
> > +        return ACTION_RESYNC;
> > +
> > +    if (mddev->reshape_position != MaxSector)
> > +        return ACTION_RESHAPE;
> > +
> > +    rcu_read_lock();
> > +    rdev_for_each_rcu(rdev, mddev) {
> > +        if (rdev->raid_disk >= 0 &&
> > +            rdev_needs_recovery(rdev, MaxSector)) {
> > +            is_recover = true;
> > +            break;
> > +        }
> > +    }
> > +    rcu_read_unlock();
> > +
> > +    return is_recover ? ACTION_RECOVER : ACTION_IDLE;
> > +}
> > +
> >   enum sync_action md_sync_action(struct mddev *mddev)
> >   {
> >       unsigned long recovery = mddev->recovery;
> > +    enum sync_action active_action;
> >         /*
> >        * frozen has the highest priority, means running sync_thread 
> > will be
> > @@ -4871,8 +4896,17 @@ enum sync_action md_sync_action(struct mddev 
> > *mddev)
> >           !test_bit(MD_RECOVERY_NEEDED, &recovery))
> >           return ACTION_IDLE;
> >   -    if (test_bit(MD_RECOVERY_RESHAPE, &recovery) ||
> > -        mddev->reshape_position != MaxSector)
> > +    /*
> > +     * Check if any sync operation (resync/recover/reshape) is
> > +     * currently active. This ensures that only one sync operation
> > +     * can run at a time. Returns the type of active operation, or
> > +     * ACTION_IDLE if none are active.
> > +     */
> > +    active_action = md_get_active_sync_action(mddev);
> > +    if (active_action != ACTION_IDLE)
> > +        return active_action;
> > +
> > +    if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
> >           return ACTION_RESHAPE;
> >         if (test_bit(MD_RECOVERY_RECOVER, &recovery))
>
> Reviewed-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
>
>
> Kind regards,
>
> Paul


Thanks,

Qixing