drm: set dev_mapping before calling drm_open_helper

Some drivers (specifically vmwgfx) look at dev_mapping
in their open hook, so we have to set dev->dev_mapping
earlier in the process.

Reference:
http://lists.freedesktop.org/archives/dri-devel/2012-October/029420.html

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Cc: stable@vger.kernel.org
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Ilija Hadzic 2012-10-29 17:35:01 +00:00 committed by Dave Airlie
parent 0f1cb1bd94
commit fdb40a08ef

View File

@ -121,6 +121,8 @@ int drm_open(struct inode *inode, struct file *filp)
int minor_id = iminor(inode);
struct drm_minor *minor;
int retcode = 0;
int need_setup = 0;
struct address_space *old_mapping;
minor = idr_find(&drm_minors_idr, minor_id);
if (!minor)
@ -132,26 +134,37 @@ int drm_open(struct inode *inode, struct file *filp)
if (drm_device_is_unplugged(dev))
return -ENODEV;
retcode = drm_open_helper(inode, filp, dev);
if (!retcode) {
atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
if (!dev->open_count++) {
retcode = drm_setup(dev);
if (retcode)
dev->open_count--;
}
}
if (!retcode) {
mutex_lock(&dev->struct_mutex);
if (dev->dev_mapping == NULL)
dev->dev_mapping = &inode->i_data;
/* ihold ensures nobody can remove inode with our i_data */
ihold(container_of(dev->dev_mapping, struct inode, i_data));
inode->i_mapping = dev->dev_mapping;
filp->f_mapping = dev->dev_mapping;
mutex_unlock(&dev->struct_mutex);
}
if (!dev->open_count++)
need_setup = 1;
mutex_lock(&dev->struct_mutex);
old_mapping = dev->dev_mapping;
if (old_mapping == NULL)
dev->dev_mapping = &inode->i_data;
/* ihold ensures nobody can remove inode with our i_data */
ihold(container_of(dev->dev_mapping, struct inode, i_data));
inode->i_mapping = dev->dev_mapping;
filp->f_mapping = dev->dev_mapping;
mutex_unlock(&dev->struct_mutex);
retcode = drm_open_helper(inode, filp, dev);
if (retcode)
goto err_undo;
atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
if (need_setup) {
retcode = drm_setup(dev);
if (retcode)
goto err_undo;
}
return 0;
err_undo:
mutex_lock(&dev->struct_mutex);
filp->f_mapping = old_mapping;
inode->i_mapping = old_mapping;
iput(container_of(dev->dev_mapping, struct inode, i_data));
dev->dev_mapping = old_mapping;
mutex_unlock(&dev->struct_mutex);
dev->open_count--;
return retcode;
}
EXPORT_SYMBOL(drm_open);