| Message ID | 20190203154200.61479-2-noralf@tronnes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/drv: Remove drm_dev_unplug() | expand |
On 2/3/19 5:41 PM, Noralf Trønnes wrote: > If userspace has open fd(s) when drm_dev_unplug() is run, it will result > in drm_dev_unregister() being called twice. First in drm_dev_unplug() and > then later in drm_release() through the call to drm_put_dev(). > > Since userspace already holds a ref on drm_device through the drm_minor, > it's not necessary to add extra ref counting based on no open file > handles. Instead just drm_dev_put() unconditionally in drm_dev_unplug(). > > We now has this: s/has/have ? > - Userpace holds a ref on drm_device as long as there's open fd(s) > - The driver holds a ref on drm_device as long as it's bound to the > struct device > > When both sides are done with drm_device, it is released. > > Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> > --- > drivers/gpu/drm/drm_drv.c | 6 +----- > drivers/gpu/drm/drm_file.c | 6 ++---- > 2 files changed, 3 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index 381581b01d48..05bbc2b622fc 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -376,11 +376,7 @@ void drm_dev_unplug(struct drm_device *dev) > synchronize_srcu(&drm_unplug_srcu); > > drm_dev_unregister(dev); > - > - mutex_lock(&drm_global_mutex); > - if (dev->open_count == 0) > - drm_dev_put(dev); > - mutex_unlock(&drm_global_mutex); > + drm_dev_put(dev); > } > EXPORT_SYMBOL(drm_dev_unplug); > > diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c > index 46f48f245eb5..3f20f598cd7c 100644 > --- a/drivers/gpu/drm/drm_file.c > +++ b/drivers/gpu/drm/drm_file.c > @@ -479,11 +479,9 @@ int drm_release(struct inode *inode, struct file *filp) > > drm_file_free(file_priv); > > - if (!--dev->open_count) { > + if (!--dev->open_count) > drm_lastclose(dev); > - if (drm_dev_is_unplugged(dev)) > - drm_put_dev(dev); > - } > + > mutex_unlock(&drm_global_mutex); > > drm_minor_release(minor);
On Sun, Feb 03, 2019 at 04:41:55PM +0100, Noralf Trønnes wrote: > If userspace has open fd(s) when drm_dev_unplug() is run, it will result > in drm_dev_unregister() being called twice. First in drm_dev_unplug() and > then later in drm_release() through the call to drm_put_dev(). > > Since userspace already holds a ref on drm_device through the drm_minor, > it's not necessary to add extra ref counting based on no open file > handles. Instead just drm_dev_put() unconditionally in drm_dev_unplug(). > > We now has this: > - Userpace holds a ref on drm_device as long as there's open fd(s) > - The driver holds a ref on drm_device as long as it's bound to the > struct device > > When both sides are done with drm_device, it is released. > > Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Sean Paul <sean@poorly.run> > --- > drivers/gpu/drm/drm_drv.c | 6 +----- > drivers/gpu/drm/drm_file.c | 6 ++---- > 2 files changed, 3 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index 381581b01d48..05bbc2b622fc 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -376,11 +376,7 @@ void drm_dev_unplug(struct drm_device *dev) > synchronize_srcu(&drm_unplug_srcu); > > drm_dev_unregister(dev); > - > - mutex_lock(&drm_global_mutex); > - if (dev->open_count == 0) > - drm_dev_put(dev); > - mutex_unlock(&drm_global_mutex); > + drm_dev_put(dev); > } > EXPORT_SYMBOL(drm_dev_unplug); > > diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c > index 46f48f245eb5..3f20f598cd7c 100644 > --- a/drivers/gpu/drm/drm_file.c > +++ b/drivers/gpu/drm/drm_file.c > @@ -479,11 +479,9 @@ int drm_release(struct inode *inode, struct file *filp) > > drm_file_free(file_priv); > > - if (!--dev->open_count) { > + if (!--dev->open_count) > drm_lastclose(dev); > - if (drm_dev_is_unplugged(dev)) > - drm_put_dev(dev); > - } > + > mutex_unlock(&drm_global_mutex); > > drm_minor_release(minor); > -- > 2.20.1 >
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 381581b01d48..05bbc2b622fc 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -376,11 +376,7 @@ void drm_dev_unplug(struct drm_device *dev) synchronize_srcu(&drm_unplug_srcu); drm_dev_unregister(dev); - - mutex_lock(&drm_global_mutex); - if (dev->open_count == 0) - drm_dev_put(dev); - mutex_unlock(&drm_global_mutex); + drm_dev_put(dev); } EXPORT_SYMBOL(drm_dev_unplug); diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index 46f48f245eb5..3f20f598cd7c 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -479,11 +479,9 @@ int drm_release(struct inode *inode, struct file *filp) drm_file_free(file_priv); - if (!--dev->open_count) { + if (!--dev->open_count) drm_lastclose(dev); - if (drm_dev_is_unplugged(dev)) - drm_put_dev(dev); - } + mutex_unlock(&drm_global_mutex); drm_minor_release(minor);
If userspace has open fd(s) when drm_dev_unplug() is run, it will result in drm_dev_unregister() being called twice. First in drm_dev_unplug() and then later in drm_release() through the call to drm_put_dev(). Since userspace already holds a ref on drm_device through the drm_minor, it's not necessary to add extra ref counting based on no open file handles. Instead just drm_dev_put() unconditionally in drm_dev_unplug(). We now has this: - Userpace holds a ref on drm_device as long as there's open fd(s) - The driver holds a ref on drm_device as long as it's bound to the struct device When both sides are done with drm_device, it is released. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> --- drivers/gpu/drm/drm_drv.c | 6 +----- drivers/gpu/drm/drm_file.c | 6 ++---- 2 files changed, 3 insertions(+), 9 deletions(-)