drm/i915: set O_LARGEFILE in __create_shmem()

Without O_LARGEFILE, file->f_op->write_iter calls
generic_write_check_limits(), which enforces a 2GB (MAX_NON_LFS) limit,
causing -EFBIG on large writes.

In shmem_pwrite(), this error is later masked as -EIO due to the error
handling order, leading to igt failures like gen9_exec_parse(bb-large).

Set O_LARGEFILE in __create_shmem() to prevent -EFBIG on large writes.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202508081029.343192ec-lkp@intel.com
Fixes: 048832a3f400 ("drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter")
Signed-off-by: Taotao Chen <chentaotao@didiglobal.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20250822030651.28099-1-chentaotao@didiglobal.com
(cherry picked from commit e296a2266c572a7537e638b0dbbfc66d11df46f9)
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index e3d188455f675429cb659c1e7cda975a10db196a..b9dae15c1d16679a83ee17cdfe8a98204a045536 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -514,6 +514,13 @@ static int __create_shmem(struct drm_i915_private *i915,
        if (IS_ERR(filp))
                return PTR_ERR(filp);
 
+       /*
+        * Prevent -EFBIG by allowing large writes beyond MAX_NON_LFS on shmem
+        * objects by setting O_LARGEFILE.
+        */
+       if (force_o_largefile())
+               filp->f_flags |= O_LARGEFILE;
+
        obj->filp = filp;
        return 0;
 }