From nobody Thu Apr 9 19:24:38 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B16BE3659F8; Fri, 6 Mar 2026 17:19:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772817574; cv=none; b=GES+Wla8BPOa4h3A41IYgOvb0rUdvO0DXJ73mPFu5DSw27ZJB6pOBVMRgU3ZGNVXj2OmY0u4GxKj8a/ixmgx4CFOZp3Dv25uNzLIcbRlyBeOowoWvbGgKKJi78jfak8z5ADPCeyNxfTBhupBBLJgI3cXWKIlifvckf0eg55ZLWs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772817574; c=relaxed/simple; bh=EX01Sv5lXfTYk78BKTDVygQlYzTzVovEBgCSXUVGYbs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tIVHjlFUYh1AlyABpFHuWS3fCSrWo6CUWLz3Z8Fu9t/b8kAKnvetXtY//IOQ2K/RbKfKXhdMD9lnNfNEEfZrLAPgHRhgCvD8GlMPeYBii47S/eJpQrgan9/ch3xR3QkXCu3ESzLQpUPiVXU3L2A3tNEPmqVdvsY794hKoTa88AY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CwJ+JaiO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CwJ+JaiO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE73BC19425; Fri, 6 Mar 2026 17:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772817574; bh=EX01Sv5lXfTYk78BKTDVygQlYzTzVovEBgCSXUVGYbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CwJ+JaiOGHHxS1bFCqciSl2ZX4/9f+bGWO8AzpSyMwdcRyKNG3sAhwH/CC0EDoJmm zkgyjEz8qKmt0R5fzfZ8dY1kx1NiV4XTSs9vTgXu0K9n/koVg47wydd37a43JXNGyZ ZE/XhHy/DdAmMbr/vnnPfX/fzyJopSE3VCuetcLg4uHzfWlJVHp4kr+olUC+RK4EvB L1KsYhaHvTBm+lkVMat2tDAlcDX/kHv7JYgFuvj2mSDAEAOeh32vxiQycKiWty2wB+ lWENr+BNKrt9mpGiMF22mjCckSRbEBDDMDdtHygFdbAUpyTZBaUP4BfpZ+O9UtXqXT yL8z/fA+jDO1A== From: Mike Rapoport To: Andrew Morton Cc: Andrea Arcangeli , Axel Rasmussen , Baolin Wang , David Hildenbrand , Hugh Dickins , James Houghton , "Liam R. Howlett" , Lorenzo Stoakes , "Matthew Wilcox (Oracle)" , Michal Hocko , Mike Rapoport , Muchun Song , Nikita Kalyazin , Oscar Salvador , Paolo Bonzini , Peter Xu , Sean Christopherson , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 11/15] userfaultfd: mfill_atomic(): remove retry logic Date: Fri, 6 Mar 2026 19:18:11 +0200 Message-ID: <20260306171815.3160826-12-rppt@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260306171815.3160826-1-rppt@kernel.org> References: <20260306171815.3160826-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Mike Rapoport (Microsoft)" Since __mfill_atomic_pte() handles the retry for both anonymous and shmem, there is no need to retry copying the date from the userspace in the loop in mfill_atomic(). Drop the retry logic from mfill_atomic(). Signed-off-by: Mike Rapoport (Microsoft) --- mm/userfaultfd.c | 24 ------------------------ 1 file changed, 24 deletions(-) diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index a0f8e67006d6..7cd7c5d1ce84 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -29,7 +29,6 @@ struct mfill_state { struct vm_area_struct *vma; unsigned long src_addr; unsigned long dst_addr; - struct folio *folio; pmd_t *pmd; }; =20 @@ -898,7 +897,6 @@ static __always_inline ssize_t mfill_atomic(struct user= faultfd_ctx *ctx, VM_WARN_ON_ONCE(src_start + len <=3D src_start); VM_WARN_ON_ONCE(dst_start + len <=3D dst_start); =20 -retry: err =3D mfill_get_vma(&state); if (err) goto out; @@ -925,26 +923,6 @@ static __always_inline ssize_t mfill_atomic(struct use= rfaultfd_ctx *ctx, err =3D mfill_atomic_pte(&state); cond_resched(); =20 - if (unlikely(err =3D=3D -ENOENT)) { - void *kaddr; - - mfill_put_vma(&state); - VM_WARN_ON_ONCE(!state.folio); - - kaddr =3D kmap_local_folio(state.folio, 0); - err =3D copy_from_user(kaddr, - (const void __user *)state.src_addr, - PAGE_SIZE); - kunmap_local(kaddr); - if (unlikely(err)) { - err =3D -EFAULT; - goto out; - } - flush_dcache_folio(state.folio); - goto retry; - } else - VM_WARN_ON_ONCE(state.folio); - if (!err) { state.dst_addr +=3D PAGE_SIZE; state.src_addr +=3D PAGE_SIZE; @@ -959,8 +937,6 @@ static __always_inline ssize_t mfill_atomic(struct user= faultfd_ctx *ctx, =20 mfill_put_vma(&state); out: - if (state.folio) - folio_put(state.folio); VM_WARN_ON_ONCE(copied < 0); VM_WARN_ON_ONCE(err > 0); VM_WARN_ON_ONCE(!copied && !err); --=20 2.51.0