On Thu, Dec 14, 2023 at 10:25:27PM -0700, Vishal Verma wrote: > Use the guard(device) macro to lock a 'struct device', and unlock it > automatically when going out of scope using Scope Based Resource > Management semantics. A lot of the sysfs attribute writes in > drivers/dax/bus.c benefit from a cleanup using these, so change these > where applicable. Wait, why are you needing to call device_lock() at all here? Why is dax special in needing this when no other subsystem requires it? > > Cc: Joao Martins <joao.m.martins@xxxxxxxxxx> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx> > --- > drivers/dax/bus.c | 143 ++++++++++++++++++++++-------------------------------- > 1 file changed, 59 insertions(+), 84 deletions(-) > > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c > index 1ff1ab5fa105..6226de131d17 100644 > --- a/drivers/dax/bus.c > +++ b/drivers/dax/bus.c > @@ -294,13 +294,10 @@ static ssize_t available_size_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > struct dax_region *dax_region = dev_get_drvdata(dev); > - unsigned long long size; > > - device_lock(dev); > - size = dax_region_avail_size(dax_region); > - device_unlock(dev); > + guard(device)(dev); You have a valid device here, why are you locking it? How can it go away? And if it can, shouldn't you have a local lock for it, and not abuse the driver core lock? > > - return sprintf(buf, "%llu\n", size); > + return sprintf(buf, "%llu\n", dax_region_avail_size(dax_region)); sysfs_emit() everywhere please. But again, the issue is "why do you need a lock"? thanks, greg k-h