On Mon, Aug 11, 2025 at 09:31:00AM +0000, 陈涛涛 Taotao Chen wrote:
> From: Taotao Chen <chentao...@didiglobal.com>
>
> shmem_pwrite() currently checks for short writes before negative error
> codes, which can overwrite real errors (e.g., -EFBIG) with -EIO.
> Reorder the checks to return negative errors first, then handle short
> writes.
>
> Fixes: 048832a3f400 ("drm/i915: Refactor shmem_pwrite() to use kiocb and
> write_iter")
> Signed-off-by: Taotao Chen <chentao...@didiglobal.com>
> ---
> drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> index 2b53aad915f5..702532eef207 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> @@ -441,12 +441,12 @@ shmem_pwrite(struct drm_i915_gem_object *obj,
> written = file->f_op->write_iter(&kiocb, &iter);
> BUG_ON(written == -EIOCBQUEUED);
>
> - if (written != size)
> - return -EIO;
> -
> if (written < 0)
> return written;
>
> + if (written != size)
> + return -EIO;
That's awkward...
I mean, you are right that we cannot overwrite what is returned from the
write_iter function. But perhaps this != check here should be before?
Or it at least deserves a comment in the code telling what's the intent
here. why != size is -EIO... but it was already written :/
> +
> return 0;
> }
>
> --
> 2.34.1
