[PATCH RFC POC 28/50] drm/msm: install the out-fence descriptor when the ioctl returns

[Christian Brauner]

Rely on the fd exit path machinery.

Signed-off-by: Christian Brauner (Amutable) <brau...@kernel.org>
---
 drivers/gpu/drm/msm/msm_gem_submit.c | 22 +++++++++-------------
 drivers/gpu/drm/msm/msm_gem_vma.c    | 22 +++++++++-------------
 2 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c 
b/drivers/gpu/drm/msm/msm_gem_submit.c
index 5862db05297a..4ddfd07c1480 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -558,7 +558,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
        struct drm_syncobj **syncobjs_to_reset = NULL;
        struct sync_file *sync_file = NULL;
        unsigned cmds_to_parse;
-       int out_fence_fd = -1;
+       const struct fd_slot *out_fence_fd = NULL;
        unsigned i;
        int ret;
 
@@ -601,9 +601,9 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
        ring = gpu->rb[queue->ring_nr];
 
        if (args->flags & MSM_SUBMIT_FENCE_FD_OUT) {
-               out_fence_fd = get_unused_fd_flags(O_CLOEXEC);
-               if (out_fence_fd < 0) {
-                       ret = out_fence_fd;
+               out_fence_fd = fd_prepare(O_CLOEXEC);
+               if (IS_ERR(out_fence_fd)) {
+                       ret = PTR_ERR(out_fence_fd);
                        goto out_post_unlock;
                }
        }
@@ -777,6 +777,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
                sync_file = sync_file_create(submit->user_fence);
                if (!sync_file)
                        ret = -ENOMEM;
+               else
+                       fd_stage(out_fence_fd, sync_file->file);
        }
 
        if (ret)
@@ -814,15 +816,9 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void 
*data,
 out_unlock:
        mutex_unlock(&queue->lock);
 out_post_unlock:
-       if (ret) {
-               if (out_fence_fd >= 0)
-                       put_unused_fd(out_fence_fd);
-               if (sync_file)
-                       fput(sync_file->file);
-       } else if (sync_file) {
-               fd_install(out_fence_fd, sync_file->file);
-               args->fence_fd = out_fence_fd;
-       }
+       /* A staged sync file and its descriptor are dropped on return. */
+       if (!ret && sync_file)
+               args->fence_fd = fd_prepare_fd(out_fence_fd);
 
        if (!IS_ERR_OR_NULL(submit)) {
                msm_gem_submit_put(submit);
diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c 
b/drivers/gpu/drm/msm/msm_gem_vma.c
index c11d021581e0..77d365566732 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -1441,7 +1441,7 @@ msm_ioctl_vm_bind(struct drm_device *dev, void *data, 
struct drm_file *file)
        struct drm_syncobj **syncobjs_to_reset = NULL;
        struct sync_file *sync_file = NULL;
        struct dma_fence *fence;
-       int out_fence_fd = -1;
+       const struct fd_slot *out_fence_fd = NULL;
        int ret, nr_bos = 0;
        unsigned i;
 
@@ -1479,9 +1479,9 @@ msm_ioctl_vm_bind(struct drm_device *dev, void *data, 
struct drm_file *file)
        }
 
        if (args->flags & MSM_VM_BIND_FENCE_FD_OUT) {
-               out_fence_fd = get_unused_fd_flags(O_CLOEXEC);
-               if (out_fence_fd < 0) {
-                       ret = out_fence_fd;
+               out_fence_fd = fd_prepare(O_CLOEXEC);
+               if (IS_ERR(out_fence_fd)) {
+                       ret = PTR_ERR(out_fence_fd);
                        goto out_post_unlock;
                }
        }
@@ -1565,6 +1565,8 @@ msm_ioctl_vm_bind(struct drm_device *dev, void *data, 
struct drm_file *file)
                sync_file = sync_file_create(job->fence);
                if (!sync_file)
                        ret = -ENOMEM;
+               else
+                       fd_stage(out_fence_fd, sync_file->file);
        }
 
        if (ret)
@@ -1593,15 +1595,9 @@ msm_ioctl_vm_bind(struct drm_device *dev, void *data, 
struct drm_file *file)
 out_unlock:
        mutex_unlock(&queue->lock);
 out_post_unlock:
-       if (ret) {
-               if (out_fence_fd >= 0)
-                       put_unused_fd(out_fence_fd);
-               if (sync_file)
-                       fput(sync_file->file);
-       } else if (sync_file) {
-               fd_install(out_fence_fd, sync_file->file);
-               args->fence_fd = out_fence_fd;
-       }
+       /* A staged sync file and its descriptor are dropped on return. */
+       if (!ret && sync_file)
+               args->fence_fd = fd_prepare_fd(out_fence_fd);
 
        if (!IS_ERR_OR_NULL(job)) {
                if (ret)

-- 
2.53.0