diff mbox series

[4/9] drm: remove the drm file system

Message ID 20210309155348.974875-5-hch@lst.de (mailing list archive)
State New
Headers show
Series [1/9] fs: rename alloc_anon_inode to alloc_anon_inode_sb | expand

Commit Message

Christoph Hellwig March 9, 2021, 3:53 p.m. UTC
Just use the generic anon_inode file system.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/gpu/drm/drm_drv.c | 64 ++-------------------------------------
 1 file changed, 3 insertions(+), 61 deletions(-)

Comments

Al Viro March 10, 2021, 4:32 p.m. UTC | #1
On Tue, Mar 09, 2021 at 04:53:43PM +0100, Christoph Hellwig wrote:
> Just use the generic anon_inode file system.

Are you changing the lifetime rules for that module?
Christoph Hellwig March 11, 2021, 8:35 a.m. UTC | #2
On Wed, Mar 10, 2021 at 04:32:34PM +0000, Al Viro wrote:
> On Tue, Mar 09, 2021 at 04:53:43PM +0100, Christoph Hellwig wrote:
> > Just use the generic anon_inode file system.
> 
> Are you changing the lifetime rules for that module?

The core drm module is pinned by the actual drivers that use the
library functions, so no.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 87e7214a8e3565..af293d76f979e5 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -26,6 +26,7 @@ 
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/anon_inodes.h>
 #include <linux/debugfs.h>
 #include <linux/fs.h>
 #include <linux/module.h>
@@ -475,65 +476,6 @@  void drm_dev_unplug(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_dev_unplug);
 
-/*
- * DRM internal mount
- * We want to be able to allocate our own "struct address_space" to control
- * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
- * stand-alone address_space objects, so we need an underlying inode. As there
- * is no way to allocate an independent inode easily, we need a fake internal
- * VFS mount-point.
- *
- * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
- * frees it again. You are allowed to use iget() and iput() to get references to
- * the inode. But each drm_fs_inode_new() call must be paired with exactly one
- * drm_fs_inode_free() call (which does not have to be the last iput()).
- * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
- * between multiple inode-users. You could, technically, call
- * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
- * iput(), but this way you'd end up with a new vfsmount for each inode.
- */
-
-static int drm_fs_cnt;
-static struct vfsmount *drm_fs_mnt;
-
-static int drm_fs_init_fs_context(struct fs_context *fc)
-{
-	return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
-}
-
-static struct file_system_type drm_fs_type = {
-	.name		= "drm",
-	.owner		= THIS_MODULE,
-	.init_fs_context = drm_fs_init_fs_context,
-	.kill_sb	= kill_anon_super,
-};
-
-static struct inode *drm_fs_inode_new(void)
-{
-	struct inode *inode;
-	int r;
-
-	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
-	if (r < 0) {
-		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
-		return ERR_PTR(r);
-	}
-
-	inode = alloc_anon_inode_sb(drm_fs_mnt->mnt_sb);
-	if (IS_ERR(inode))
-		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
-
-	return inode;
-}
-
-static void drm_fs_inode_free(struct inode *inode)
-{
-	if (inode) {
-		iput(inode);
-		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
-	}
-}
-
 /**
  * DOC: component helper usage recommendations
  *
@@ -563,7 +505,7 @@  static void drm_dev_init_release(struct drm_device *dev, void *res)
 {
 	drm_legacy_ctxbitmap_cleanup(dev);
 	drm_legacy_remove_map_hash(dev);
-	drm_fs_inode_free(dev->anon_inode);
+	iput(dev->anon_inode);
 
 	put_device(dev->dev);
 	/* Prevent use-after-free in drm_managed_release when debugging is
@@ -616,7 +558,7 @@  static int drm_dev_init(struct drm_device *dev,
 	if (ret)
 		return ret;
 
-	dev->anon_inode = drm_fs_inode_new();
+	dev->anon_inode = alloc_anon_inode();
 	if (IS_ERR(dev->anon_inode)) {
 		ret = PTR_ERR(dev->anon_inode);
 		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);