[PATCH v5 0/2] vfs: add O_EMPTYPATH to openat(2)/openat2(2)

[Jori Koolstra]

Hi Christian,

I've rebased this on vfs-7.2.misc as Aleksa suggested. Also moved the
O_EMPTYPATH bit to 1<<26 to avoid conflict with non asm-generic O_*
flags.

---

To get an operable version of an O_PATH file descriptor, it is possible
to use openat(fd, ".", O_DIRECTORY) for directories, but other files
currently require going through open("/proc/<pid>/fd/<nr>"), which
depends on a functioning procfs.

This patch adds the O_EMPTYPATH flag to openat(2)/openat2(2). If passed,
LOOKUP_EMPTY is set at path resolution time.

Jori Koolstra (2):
  vfs: add O_EMPTYPATH to openat(2)/openat2(2)
  selftest: add tests for O_EMPTYPATH

 fs/fcntl.c                                    |  2 +-
 fs/open.c                                     |  6 +-
 include/linux/fcntl.h                         |  2 +-
 include/uapi/asm-generic/fcntl.h              |  4 ++
 tools/include/uapi/linux/openat2.h            | 43 +++++++++++++++
 .../selftests/filesystems/openat2/Makefile    |  4 +-
 .../filesystems/openat2/emptypath_test.c      | 55 +++++++++++++++++++
 .../selftests/filesystems/openat2/helpers.h   | 35 +-----------
 8 files changed, 111 insertions(+), 40 deletions(-)
 create mode 100644 tools/include/uapi/linux/openat2.h
 create mode 100644 tools/testing/selftests/filesystems/openat2/emptypath_test.c

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2.54.0