Re: [PATCH v5 0/4] OPENAT2_REGULAR flag support for openat2

Dorjoy Chowdhury
2026-03-16T16:12:50Z

Ping...
Requesting for review on this patch series please.

Regards,
Dorjoy

On Sat, Mar 7, 2026 at 8:07 PM Dorjoy Chowdhury <dorjoychy111@gmail.com> wrote:
>
> Hi,
>
> I came upon this "Ability to only open regular files" uapi feature suggestion
> from https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files
> and thought it would be something I could do as a first patch and get to
> know the kernel code a bit better.
>
> The following filesystems have been tested by building and booting the kernel
> x86 bzImage in a Fedora 43 VM in QEMU. I have tested with OPENAT2_REGULAR that
> regular files can be successfully opened and non-regular files (directory, fifo etc)
> return -EFTYPE.
> - btrfs
> - NFS (loopback)
> - SMB (loopback)
>
> Changes in v5:
> - EFTYPE is already used in BSDs mentioned in commit message
> - consistently return -EFTYPE in all filesystems
>
> Changes in v4:
> - changed O_REGULAR to OPENAT2_REGULAR
> - OPENAT2_REGULAR does not affect O_PATH
> - atomic_open codepaths updated to work properly for OPENAT2_REGULAR
> - commit message includes the uapi-group URL
> - v3 is at: https://lore.kernel.org/linux-fsdevel/20260127180109.66691-1-dorjoychy111@gmail.com/T/
>
> Changes in v3:
> - included motivation about O_REGULAR flag in commit message e.g., programs not wanting to be tricked into opening device nodes
> - fixed commit message wrongly referencing ENOTREGULAR instead of ENOTREG
> - fixed the O_REGULAR flag in arch/parisc/include/uapi/asm/fcntl.h from 060000000 to 0100000000
> - added 2 commits converting arch/{mips,sparc}/include/uapi/asm/fcntl.h O_* macros from hex to octal
> - v2 is at: https://lore.kernel.org/linux-fsdevel/20260126154156.55723-1-dorjoychy111@gmail.com/T/
>
> Changes in v2:
> - rename ENOTREGULAR to ENOTREG
> - define ENOTREG in uapi/asm-generic/errno.h (instead of errno-base.h) and in arch/*/include/uapi/asm/errno.h files
> - override O_REGULAR in arch/{alpha,sparc,parisc}/include/uapi/asm/fcntl.h due to clash with include/uapi/asm-generic/fcntl.h
> - I have kept the kselftest but now that O_REGULAR and ENOTREG can have different value on different architectures I am not sure if it's right
> - v1 is at: https://lore.kernel.org/linux-fsdevel/20260125141518.59493-1-dorjoychy111@gmail.com/T/
>
> Thanks.
>
> Regards,
> Dorjoy
>
> Dorjoy Chowdhury (4):
> openat2: new OPENAT2_REGULAR flag support
> kselftest/openat2: test for OPENAT2_REGULAR flag
> sparc/fcntl.h: convert O_* flag macros from hex to octal
> mips/fcntl.h: convert O_* flag macros from hex to octal
>
> arch/alpha/include/uapi/asm/errno.h | 2 +
> arch/alpha/include/uapi/asm/fcntl.h | 1 +
> arch/mips/include/uapi/asm/errno.h | 2 +
> arch/mips/include/uapi/asm/fcntl.h | 22 +++++------
> arch/parisc/include/uapi/asm/errno.h | 2 +
> arch/parisc/include/uapi/asm/fcntl.h | 1 +
> arch/sparc/include/uapi/asm/errno.h | 2 +
> arch/sparc/include/uapi/asm/fcntl.h | 35 +++++++++---------
> fs/ceph/file.c | 4 ++
> fs/gfs2/inode.c | 6 +++
> fs/namei.c | 4 ++
> fs/nfs/dir.c | 4 ++
> fs/open.c | 4 +-
> fs/smb/client/dir.c | 14 ++++++-
> include/linux/fcntl.h | 2 +
> include/uapi/asm-generic/errno.h | 2 +
> include/uapi/asm-generic/fcntl.h | 4 ++
> tools/arch/alpha/include/uapi/asm/errno.h | 2 +
> tools/arch/mips/include/uapi/asm/errno.h | 2 +
> tools/arch/parisc/include/uapi/asm/errno.h | 2 +
> tools/arch/sparc/include/uapi/asm/errno.h | 2 +
> tools/include/uapi/asm-generic/errno.h | 2 +
> .../testing/selftests/openat2/openat2_test.c | 37 ++++++++++++++++++-
> 23 files changed, 127 insertions(+), 31 deletions(-)
>
> --
> 2.53.0
>