| Message ID | 1465930269-7883-6-git-send-email-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jun 14, 2016 at 08:51:00PM +0200, Daniel Vetter wrote: > And pull out the primary_client check to make it really obvious that > this can't happen on control/render nodes. Bonus that we can avoid the > master lock in this case. ...as the minor->type is statically assigned on creation and so inspection doesn't require the lock. > v2: Don't leak locks on error path (and simplify control flow while > at it), reported by Julia. > > Cc: Julia Lawall <julia.lawall@lip6.fr> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/drm_auth.c | 19 ++++++++++++++++++- > drivers/gpu/drm/drm_fops.c | 13 ++----------- > drivers/gpu/drm/drm_internal.h | 2 +- > 3 files changed, 21 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c > index 1d314ae13560..9c1e2081cd58 100644 > --- a/drivers/gpu/drm/drm_auth.c > +++ b/drivers/gpu/drm/drm_auth.c > @@ -120,7 +120,7 @@ static struct drm_master *drm_master_create(struct drm_device *dev) > * This function must be called with dev::struct_mutex held. > * Returns negative error code on failure. Zero on success. > */ > -int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) > +static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) > { > struct drm_master *old_master; > int ret; > @@ -226,6 +226,23 @@ out_unlock: > return ret; > } > > +int drm_master_open(struct drm_file *file_priv) > +{ > + struct drm_device *dev = file_priv->minor->dev; > + int ret = 0; > + > + /* if there is no current master make this fd it, but do not create > + * any master object for render clients */ The second half of this comment is out of place, it is referring to drm_is_primary_client(). > + mutex_lock(&dev->master_mutex); > + if (!file_priv->minor->master) > + ret = drm_new_set_master(dev, file_priv); > + else > + file_priv->master = drm_master_get(file_priv->minor->master); > + mutex_unlock(&dev->master_mutex); > + > + return ret; > +} > + > struct drm_master *drm_master_get(struct drm_master *master) > { > kref_get(&master->refcount); > diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c > index 50b3de990aee..e2522672719a 100644 > --- a/drivers/gpu/drm/drm_fops.c > +++ b/drivers/gpu/drm/drm_fops.c > @@ -229,19 +229,11 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor) > goto out_prime_destroy; > } > > - /* if there is no current master make this fd it, but do not create > - * any master object for render clients */ > - mutex_lock(&dev->master_mutex); > - if (drm_is_primary_client(priv) && !priv->minor->master) { > - /* create a new master */ > - ret = drm_new_set_master(dev, priv); > + if (drm_is_primary_client(priv)) { > + ret = drm_master_open(priv); > if (ret) Both drm_is_primary_client() and drm_master_open() are acting on drm_minor not drm_file. Idle speculation if that makes the code any clearer. -Chris
diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 1d314ae13560..9c1e2081cd58 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -120,7 +120,7 @@ static struct drm_master *drm_master_create(struct drm_device *dev) * This function must be called with dev::struct_mutex held. * Returns negative error code on failure. Zero on success. */ -int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) +static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) { struct drm_master *old_master; int ret; @@ -226,6 +226,23 @@ out_unlock: return ret; } +int drm_master_open(struct drm_file *file_priv) +{ + struct drm_device *dev = file_priv->minor->dev; + int ret = 0; + + /* if there is no current master make this fd it, but do not create + * any master object for render clients */ + mutex_lock(&dev->master_mutex); + if (!file_priv->minor->master) + ret = drm_new_set_master(dev, file_priv); + else + file_priv->master = drm_master_get(file_priv->minor->master); + mutex_unlock(&dev->master_mutex); + + return ret; +} + struct drm_master *drm_master_get(struct drm_master *master) { kref_get(&master->refcount); diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 50b3de990aee..e2522672719a 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -229,19 +229,11 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor) goto out_prime_destroy; } - /* if there is no current master make this fd it, but do not create - * any master object for render clients */ - mutex_lock(&dev->master_mutex); - if (drm_is_primary_client(priv) && !priv->minor->master) { - /* create a new master */ - ret = drm_new_set_master(dev, priv); + if (drm_is_primary_client(priv)) { + ret = drm_master_open(priv); if (ret) goto out_close; - } else if (drm_is_primary_client(priv)) { - /* get a reference to the master */ - priv->master = drm_master_get(priv->minor->master); } - mutex_unlock(&dev->master_mutex); mutex_lock(&dev->filelist_mutex); list_add(&priv->lhead, &dev->filelist); @@ -270,7 +262,6 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor) return 0; out_close: - mutex_unlock(&dev->master_mutex); if (dev->driver->postclose) dev->driver->postclose(dev, priv); out_prime_destroy: diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index d29d426f633f..2b9a94f679ed 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -66,7 +66,7 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); int drm_dropmaster_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); -int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv); +int drm_master_open(struct drm_file *file_priv); /* drm_sysfs.c */ extern struct class *drm_class;
And pull out the primary_client check to make it really obvious that this can't happen on control/render nodes. Bonus that we can avoid the master lock in this case. v2: Don't leak locks on error path (and simplify control flow while at it), reported by Julia. Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> --- drivers/gpu/drm/drm_auth.c | 19 ++++++++++++++++++- drivers/gpu/drm/drm_fops.c | 13 ++----------- drivers/gpu/drm/drm_internal.h | 2 +- 3 files changed, 21 insertions(+), 13 deletions(-)