From nobody Sat Apr 4 03:19:47 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 B2BA83612F6; Thu, 2 Apr 2026 04:13:21 +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=1775103201; cv=none; b=BkEnkDAkno3yFqBQnRrEMOp/6U/XQsrrqiX/5CtUOCUkAN78fRKADPjjgTha9bDlJihyhwtr1FPvUzWt8WNXc0NX4Urhv1U0JtLCSk3PqrKOJvHHsazsS6jWUtxWIlbrQ/VIpjByahrmDtfW6mx2cza58k+UIt9jyEPar2waVQQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775103201; c=relaxed/simple; bh=5vaQGQBc3neyldkli11Rg6Y+SDtyLj7BMfixF4/GPSE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ur1nDUPvqUv75LG6V9yXl+Uavl2PspcXJg3zOKXFNJdqqs9xYMgcsSnM30uJi4JwX8eq/v6VfTIxjyT7twiVDZTdPq5jCSr4bLZbgY+iZiqkKQfXh4vz1Oa+MOu76GxYTnmLC8ixP+ky/4i1SNGg9Wv9gt8G1lyyF2OUm83Bz3A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bt28/m2f; 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="Bt28/m2f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 178EFC19423; Thu, 2 Apr 2026 04:13:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775103201; bh=5vaQGQBc3neyldkli11Rg6Y+SDtyLj7BMfixF4/GPSE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bt28/m2fkum5A4fexrkHIDiwLmCZisqPq7kYstTpZa4gEYge6jHYkI04dMh8zD8uw Z2KjPZ2GxXl1j5Y/ahMEY7rHgurRo+c/83O8XQj65p1XtNHEOfoXNVei3oY41GnY9m oe9q7EwPbyUpcMLozGy5HkrGB9QGlPUdhRlmbNNV0HKXR21y6jtVRSwKLdU6N7+JVA MPKbfI253YnvrF296FFA/9AFxYH9o3fuqQ5JBlzyuGE9+4s4UaZjnp8X40iLlR/eEz jCsqbSNE7alCszlRzkgCMtGJHHUovkALONmzswZrWCLGdDC1uQLrSJMrXY2RCvwpCh a/Lfg2MwHGhPQ== From: Mike Rapoport To: Andrew Morton Cc: Andrea Arcangeli , Andrei Vagin , Axel Rasmussen , Baolin Wang , David Hildenbrand , Harry Yoo , Hugh Dickins , James Houghton , "Liam R. Howlett" , "Lorenzo Stoakes (Oracle)" , "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 v4 11/15] userfaultfd: mfill_atomic(): remove retry logic Date: Thu, 2 Apr 2026 07:11:52 +0300 Message-ID: <20260402041156.1377214-12-rppt@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260402041156.1377214-1-rppt@kernel.org> References: <20260402041156.1377214-1-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 e672a9e45d0c..935a3f6ebeed 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 @@ -899,7 +898,6 @@ 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; @@ -926,26 +924,6 @@ 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; @@ -960,8 +938,6 @@ 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 2.53.0