Re: [PATCH v4 0/4] OPENAT2_REGULAR flag support in openat2

Dorjoy Chowdhury
2026-03-01T10:16:25Z

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

Regards,
Dorjoy

On Sat, Feb 21, 2026 at 8:59 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.
>
> I only tested this new flag on my local system (fedora btrfs).
>
> Note that I had submitted a v4 previously (that had -EINVAL for the atomic_open
> code paths) but did not do a get_maintainers.pl. It didn't get any review and
> please ignore that one anyway. In this version, I have tried to properly update
> the filesystems that provide atomic_open (fs/ceph, fs/nfs, fs/smb, fs/gfs2,
> fs/fuse, fs/vboxsf, fs/9p) for the new OPENAT2_REGULAR flag. Some of them
> (fs/fuse, fs/vboxsf, fs/9p) didn't need any changing. As far as I see, most of
> the filesystems do finish_no_open for ~O_CREAT and have file->f_mode |= FMODE_CREATED
> for the O_CREAT code path which I assume means they always create new file which
> is a regular file. OPENAT2_REGULAR | O_DIRECTORY returns -EINVAL (instead of working
> if path is either a directory or regular file) as it was easier to reason about when
> making changes in all the 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 | 2 +
> fs/namei.c | 4 ++
> fs/nfs/dir.c | 4 +-
> fs/open.c | 4 +-
> fs/smb/client/dir.c | 11 +++++-
> 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, 119 insertions(+), 32 deletions(-)
>
> --
> 2.53.0
>