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b=CYGBvzgCralwJZXcb0Y2UZClDnlHuroFvQBjHLNkJVVS4+pnQhVEG3V2staNu5jrd IkSKhRt2bkZr1QbF0CxiNYkZCxNPn1F5nOv9euSu8Xa6OKn0LDTqz2zk0xrTB9Uk3A RuPCMW4ps6khOcWMXhEWISemaOHClc8Gk3onWUelkzzt2GggfHsK5JdBF2Spj+wX7l RfCeJ3cVhoQt+G8lagbhV/qnb0nDvti3Z3+8amQxWikfEEq9zlr+uCfLdSDNfEtAgQ z+LHlM9iZRxwW0X18KeNCPduyfa9lS2ZkbfonX5I40ePeYjjuDewHgU8DAXyRV734y JzxZjk2EMqdjA== From: Pratyush Yadav To: Zhu Yanjun Cc: Pratyush Yadav , Pasha Tatashin , Mike Rapoport , Shuah Khan , Andrew Morton , Usama Arif , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 2/6] selftests/liveupdate: add helper functions for memfd tests In-Reply-To: (Zhu Yanjun's message of "Sat, 4 Apr 2026 10:53:47 -0700") References: <20260404102452.4091740-1-pratyush@kernel.org> <20260404102452.4091740-3-pratyush@kernel.org> Date: Sun, 05 Apr 2026 07:34:00 +0000 Message-ID: <2vxzecktc13r.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 2AF7DC000C X-Stat-Signature: eiw6ohytrh5ss5t1oj1z6ukbid8akz7d X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1775374444-587235 X-HE-Meta: U2FsdGVkX18PIFfTiVoGJE73RzeddRfbVFssRWEK/S+ETWdZU6aBGI7frjlZY4B9Ot4sRtK3ojzD/M/Hvw5fwH7DJ2f9V/w3HIU+lgL9cqDnP0Omw/pViOsx3eNTBoYTY03bgXDL3Vfew/U433UIrolTwo4OO1/+pITI0z6a/esFE3bLhZTn96yOz+cZcZYm24N6MTfKHBPLHRPZxe/Zvjh2HqoUZr8nuCkPNYtH5RtJrhB8C+RCtZrDHLIy07nqMRYcJS3QWmjaUaqrPQRHxzAMLSJT2hduHVA4r3bzjxQYGlNfbvD3A+6WtwJ857VK9Hgsh9WTQ7B73plKen1sLAmk9VgbGLT1G+MtTjTrI6QUWmzMoLrcw9M5nVAxaUi06W/5lssaAsOvb25uM1A+Nu9AKlIjZnHyMnQfheyHNZnp0F019AXILvJ+pENyTj1sKWFbXdMsBCdjGvUkdAqaQvI1WZW2w9I/Pu5u7cLkznDBUVKweLUY8hSjSnQWYI6Pk5VE57+9PBT3QoDvRkdm+/evDt7zAZRTYMJG2xPyTSudi2qKKjnq3Ia5i1E6zqD2QCU0tOzHB5VzYeMKsuQSACgNjJ+bTP+zefdjaVWWUp+cMaXPkSgQw7G76/Y3qgn/zdriqbkNvGucdib4rcld8OTHYuSduBnxADOnWFDsyJgcwiMSMFjP3cgjpIzB5NacQGY4qZHqasAljkXgQ3fK20sCKrze36Yw6OdqF4dDQGrfKg3mHCiVUJ+FQr+GyRobTrw/sTDsWL/CPu1X2fABvrYCD2lk148oL/YlDfQFme/Bn5x/fkuvFHUpumaCx1p1Af0ODkoDfGnxM4LHj6QOpNYN5LcVJkgqM8uIolcAADwiigPY4Zmu+y9OI+b8LslR4jFDce5nTbb61N2PXcyggIqY5avK1FKZfTJUDsN9cHfJAsMERPnaTL1DyvTSVTpN02z8M7kwE1pPpWDBaGS Z9b2Siet CMZL2Y8LMEB9mlS96Q+i29uZ5LBOpbK0DgPUlrAU1XPY3B2I+wlKidWOeblc1yu0b/1UR25f6weh1XQPdFwC4uHwefQyY7+grbxLeHf/aLWdQzTDa5jiyrQlUdS4Oxmtw2bNnHUtkyrrTJraLOX9A3wL3Kj8YBu/bRm/naE1TCxt7RNXK1H8+AXQFy/ucYlKuYx/LTYoLEwbCUznYwvDbRS+zfQ3NKGQVdHZdgbPom7oOcFQL2SJI4XpW7gfyXWxqekYmW+RlaypDasTc4q4nSfiVteXwCs6WcNO5 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, Apr 04 2026, Zhu Yanjun wrote: > =E5=9C=A8 2026/4/4 3:24, Pratyush Yadav =E5=86=99=E9=81=93: >> From: "Pratyush Yadav (Google)" >> Add some helper functions that will be used by memfd tests. This moves >> some of the complexity out of the test itself, which results in better >> test readability and less code duplication. >> Reviewed-by: Mike Rapoport (Microsoft) >> Signed-off-by: Pratyush Yadav >> Signed-off-by: Pratyush Yadav (Google) >> --- >> .../selftests/liveupdate/luo_test_utils.c | 191 +++++++++++++++++- >> .../selftests/liveupdate/luo_test_utils.h | 10 + >> 2 files changed, 200 insertions(+), 1 deletion(-) >> diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.c >> b/tools/testing/selftests/liveupdate/luo_test_utils.c >> index 3c8721c505df..ceb918ef9813 100644 >> --- a/tools/testing/selftests/liveupdate/luo_test_utils.c >> +++ b/tools/testing/selftests/liveupdate/luo_test_utils.c >> @@ -1,8 +1,12 @@ >> // SPDX-License-Identifier: GPL-2.0-only >> /* >> - * Copyright (c) 2025, Google LLC. >> + * Copyright (c) 2025-2026, Google LLC. >> * Pasha Tatashin >> + * Pratyush Yadav (Google) >> + * >> + * Copyright (C) 2025 Amazon.com Inc. or its affiliates. >> + * Pratyush Yadav >> */ >> #define _GNU_SOURCE >> @@ -20,9 +24,194 @@ >> #include >> #include >> #include >> +#include >> +#include >> #include "luo_test_utils.h" >> +int cwd_is_tmpfs(void) >> +{ >> + struct statfs buf; >> + >> + if (statfs(".", &buf) < 0) >> + return -errno; >> + >> + return buf.f_type =3D=3D TMPFS_MAGIC; >> +} >> + >> +/* Read exactly specified size from fd. Any less results in error. */ >> +int read_size(int fd, char *buffer, size_t size) >> +{ >> + size_t remain =3D size; >> + ssize_t bytes_read; >> + >> + while (remain) { > > while (remain > 0) ? I don't think it is needed. bytes_read will always be smaller than or equal to remain, so remain will never go below 0 anyway. And while (remain) is nicer to read. > >> + bytes_read =3D read(fd, buffer, remain); >> + if (bytes_read =3D=3D 0) >> + return -ENODATA; >> + if (bytes_read < 0) { >> + if (errno =3D=3D EINTR) >> + continue; >> + else >> + return -errno; >> + } >> + >> + remain -=3D bytes_read; >> + buffer +=3D bytes_read; >> + } >> + >> + return 0; >> +} >> + [...] --=20 Regards, Pratyush Yadav