* [PATCH v4 1/4] openat2: new OPENAT2_REGULAR flag support
2026-02-06 19:03 [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
@ 2026-02-06 19:03 ` Dorjoy Chowdhury
2026-02-06 19:03 ` [PATCH v4 2/4] kselftest/openat2: test for OPENAT2_REGULAR flag Dorjoy Chowdhury
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Dorjoy Chowdhury @ 2026-02-06 19:03 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-kernel, viro, brauner, jack, jlayton, chuck.lever,
alex.aring, arnd, adilger, mjguzik, smfrench
This flag indicates the path should be opened if it's a regular file.
This is useful to write secure programs that want to avoid being tricked
into opening device nodes with special semantics while thinking they
operate on regular files. This is a requested feature from uapi-group[1].
A corresponding error code EFTYPE has been introduced. For example, if
openat2 is called on path /dev/null with OPENAT2_REGULAR in the flag param,
it will return -EFTYPE.
When used in combination with O_CREAT, either the regular file is
created, or if the path already exists, it is opened if it's a regular
file. Otherwise, -EFTYPE is returned.
When OPENAT2_REGULAR is combined with O_DIRECTORY, the path will be opened
if the path is either a regular file or a directory.
[1]: https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files
Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
---
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/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 | 1 +
fs/9p/vfs_inode.c | 3 +++
fs/9p/vfs_inode_dotl.c | 3 +++
fs/ceph/file.c | 3 +++
fs/fuse/dir.c | 3 +++
fs/gfs2/inode.c | 3 +++
fs/namei.c | 9 ++++++++-
fs/nfs/dir.c | 3 +++
fs/nfs/file.c | 3 +++
fs/open.c | 2 +-
fs/smb/client/dir.c | 3 +++
fs/vboxsf/dir.c | 3 +++
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 ++
26 files changed, 65 insertions(+), 2 deletions(-)
diff --git a/arch/alpha/include/uapi/asm/errno.h b/arch/alpha/include/uapi/asm/errno.h
index 6791f6508632..1a99f38813c7 100644
--- a/arch/alpha/include/uapi/asm/errno.h
+++ b/arch/alpha/include/uapi/asm/errno.h
@@ -127,4 +127,6 @@
#define EHWPOISON 139 /* Memory page has hardware error */
+#define EFTYPE 140 /* Wrong file type for the intended operation */
+
#endif
diff --git a/arch/alpha/include/uapi/asm/fcntl.h b/arch/alpha/include/uapi/asm/fcntl.h
index 50bdc8e8a271..fe488bf7c18e 100644
--- a/arch/alpha/include/uapi/asm/fcntl.h
+++ b/arch/alpha/include/uapi/asm/fcntl.h
@@ -34,6 +34,7 @@
#define O_PATH 040000000
#define __O_TMPFILE 0100000000
+#define OPENAT2_REGULAR 0200000000
#define F_GETLK 7
#define F_SETLK 8
diff --git a/arch/mips/include/uapi/asm/errno.h b/arch/mips/include/uapi/asm/errno.h
index c01ed91b1ef4..1835a50b69ce 100644
--- a/arch/mips/include/uapi/asm/errno.h
+++ b/arch/mips/include/uapi/asm/errno.h
@@ -126,6 +126,8 @@
#define EHWPOISON 168 /* Memory page has hardware error */
+#define EFTYPE 169 /* Wrong file type for the intended operation */
+
#define EDQUOT 1133 /* Quota exceeded */
diff --git a/arch/parisc/include/uapi/asm/errno.h b/arch/parisc/include/uapi/asm/errno.h
index 8cbc07c1903e..93194fbb0a80 100644
--- a/arch/parisc/include/uapi/asm/errno.h
+++ b/arch/parisc/include/uapi/asm/errno.h
@@ -124,4 +124,6 @@
#define EHWPOISON 257 /* Memory page has hardware error */
+#define EFTYPE 258 /* Wrong file type for the intended operation */
+
#endif
diff --git a/arch/parisc/include/uapi/asm/fcntl.h b/arch/parisc/include/uapi/asm/fcntl.h
index 03dee816cb13..d46812f2f0f4 100644
--- a/arch/parisc/include/uapi/asm/fcntl.h
+++ b/arch/parisc/include/uapi/asm/fcntl.h
@@ -19,6 +19,7 @@
#define O_PATH 020000000
#define __O_TMPFILE 040000000
+#define OPENAT2_REGULAR 0100000000
#define F_GETLK64 8
#define F_SETLK64 9
diff --git a/arch/sparc/include/uapi/asm/errno.h b/arch/sparc/include/uapi/asm/errno.h
index 4a41e7835fd5..71940ec9130b 100644
--- a/arch/sparc/include/uapi/asm/errno.h
+++ b/arch/sparc/include/uapi/asm/errno.h
@@ -117,4 +117,6 @@
#define EHWPOISON 135 /* Memory page has hardware error */
+#define EFTYPE 136 /* Wrong file type for the intended operation */
+
#endif
diff --git a/arch/sparc/include/uapi/asm/fcntl.h b/arch/sparc/include/uapi/asm/fcntl.h
index 67dae75e5274..bb6e9fa94bc9 100644
--- a/arch/sparc/include/uapi/asm/fcntl.h
+++ b/arch/sparc/include/uapi/asm/fcntl.h
@@ -37,6 +37,7 @@
#define O_PATH 0x1000000
#define __O_TMPFILE 0x2000000
+#define OPENAT2_REGULAR 0x4000000
#define F_GETOWN 5 /* for sockets. */
#define F_SETOWN 6 /* for sockets. */
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 97abe65bf7c1..3d1f91220e17 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -771,6 +771,9 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
struct inode *inode;
int p9_omode;
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
if (d_in_lookup(dentry)) {
struct dentry *res = v9fs_vfs_lookup(dir, dentry, 0);
if (res || d_really_is_positive(dentry))
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 643e759eacb2..2e096eb0be11 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -239,6 +239,9 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
struct v9fs_session_info *v9ses;
struct posix_acl *pacl = NULL, *dacl = NULL;
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
if (d_in_lookup(dentry)) {
struct dentry *res = v9fs_vfs_lookup(dir, dentry, 0);
if (res || d_really_is_positive(dentry))
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 31b691b2aea2..d0fa6cd65e0a 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -794,6 +794,9 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
if (dentry->d_name.len > NAME_MAX)
return -ENAMETOOLONG;
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
err = ceph_wait_on_conflict_unlink(dentry);
if (err)
return err;
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index f25ee47822ad..cbc6008f6810 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -936,6 +936,9 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
if (fuse_is_bad(dir))
return -EIO;
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
if (d_in_lookup(entry)) {
struct dentry *res = fuse_lookup(dir, entry, 0);
if (res || d_really_is_positive(entry))
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index c02ebf0ca625..1efb86b718e1 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1385,6 +1385,9 @@ static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
{
bool excl = !!(flags & O_EXCL);
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
if (d_in_lookup(dentry)) {
struct dentry *d = __gfs2_lookup(dir, dentry, file);
if (file->f_mode & FMODE_OPENED) {
diff --git a/fs/namei.c b/fs/namei.c
index d7923f2c7b62..a5ce3f91a283 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4614,8 +4614,15 @@ static int do_open(struct nameidata *nd,
if (unlikely(error))
return error;
}
- if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry))
+
+ if ((open_flag & OPENAT2_REGULAR) && (nd->flags & LOOKUP_DIRECTORY)) {
+ if (!d_is_reg(nd->path.dentry) && !d_can_lookup(nd->path.dentry))
+ return -EFTYPE;
+ } else if ((open_flag & OPENAT2_REGULAR) && !d_is_reg(nd->path.dentry)) {
+ return -EFTYPE;
+ } else if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry)) {
return -ENOTDIR;
+ }
do_truncate = false;
acc_mode = op->acc_mode;
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 8f9ea79b7882..ae12bf75ad93 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2315,6 +2315,9 @@ int nfs_atomic_open_v23(struct inode *dir, struct dentry *dentry,
if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
return -ENAMETOOLONG;
+ if (open_flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
if (open_flags & O_CREAT) {
error = nfs_do_create(dir, dentry, mode, open_flags);
if (!error) {
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 5d08b6409c28..032fc3dbe992 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -52,6 +52,9 @@ int nfs_check_flags(int flags)
if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT))
return -EINVAL;
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
return 0;
}
EXPORT_SYMBOL_GPL(nfs_check_flags);
diff --git a/fs/open.c b/fs/open.c
index 74c4c1462b3e..2cef40a3f139 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1211,7 +1211,7 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op)
* values before calling build_open_flags(), but openat2(2) checks all
* of its arguments.
*/
- if (flags & ~VALID_OPEN_FLAGS)
+ if (flags & ~VALID_OPENAT2_FLAGS)
return -EINVAL;
if (how->resolve & ~VALID_RESOLVE_FLAGS)
return -EINVAL;
diff --git a/fs/smb/client/dir.c b/fs/smb/client/dir.c
index 747256025e49..fc77c5401574 100644
--- a/fs/smb/client/dir.c
+++ b/fs/smb/client/dir.c
@@ -473,6 +473,9 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
return smb_EIO(smb_eio_trace_forced_shutdown);
+ if (oflags & OPENAT2_REGULAR)
+ return -EINVAL;
+
/*
* Posix open is only called (at lookup time) for file create now. For
* opens (rather than creates), because we do not know if it is a file
diff --git a/fs/vboxsf/dir.c b/fs/vboxsf/dir.c
index 42bedc4ec7af..936ba2962fd0 100644
--- a/fs/vboxsf/dir.c
+++ b/fs/vboxsf/dir.c
@@ -318,6 +318,9 @@ static int vboxsf_dir_atomic_open(struct inode *parent, struct dentry *dentry,
u64 handle;
int err;
+ if (flags & OPENAT2_REGULAR)
+ return -EINVAL;
+
if (d_in_lookup(dentry)) {
struct dentry *res = vboxsf_dir_lookup(parent, dentry, 0);
if (res || d_really_is_positive(dentry))
diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h
index a332e79b3207..a80026718217 100644
--- a/include/linux/fcntl.h
+++ b/include/linux/fcntl.h
@@ -12,6 +12,8 @@
FASYNC | O_DIRECT | O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | \
O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE)
+#define VALID_OPENAT2_FLAGS (VALID_OPEN_FLAGS | OPENAT2_REGULAR)
+
/* List of all valid flags for the how->resolve argument: */
#define VALID_RESOLVE_FLAGS \
(RESOLVE_NO_XDEV | RESOLVE_NO_MAGICLINKS | RESOLVE_NO_SYMLINKS | \
diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
index 92e7ae493ee3..bd78e69e0a43 100644
--- a/include/uapi/asm-generic/errno.h
+++ b/include/uapi/asm-generic/errno.h
@@ -122,4 +122,6 @@
#define EHWPOISON 133 /* Memory page has hardware error */
+#define EFTYPE 134 /* Wrong file type for the intended operation */
+
#endif
diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-generic/fcntl.h
index 613475285643..b2c2ddd0edc0 100644
--- a/include/uapi/asm-generic/fcntl.h
+++ b/include/uapi/asm-generic/fcntl.h
@@ -88,6 +88,10 @@
#define __O_TMPFILE 020000000
#endif
+#ifndef OPENAT2_REGULAR
+#define OPENAT2_REGULAR 040000000
+#endif
+
/* a horrid kludge trying to make sure that this will fail on old kernels */
#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
diff --git a/tools/arch/alpha/include/uapi/asm/errno.h b/tools/arch/alpha/include/uapi/asm/errno.h
index 6791f6508632..1a99f38813c7 100644
--- a/tools/arch/alpha/include/uapi/asm/errno.h
+++ b/tools/arch/alpha/include/uapi/asm/errno.h
@@ -127,4 +127,6 @@
#define EHWPOISON 139 /* Memory page has hardware error */
+#define EFTYPE 140 /* Wrong file type for the intended operation */
+
#endif
diff --git a/tools/arch/mips/include/uapi/asm/errno.h b/tools/arch/mips/include/uapi/asm/errno.h
index c01ed91b1ef4..1835a50b69ce 100644
--- a/tools/arch/mips/include/uapi/asm/errno.h
+++ b/tools/arch/mips/include/uapi/asm/errno.h
@@ -126,6 +126,8 @@
#define EHWPOISON 168 /* Memory page has hardware error */
+#define EFTYPE 169 /* Wrong file type for the intended operation */
+
#define EDQUOT 1133 /* Quota exceeded */
diff --git a/tools/arch/parisc/include/uapi/asm/errno.h b/tools/arch/parisc/include/uapi/asm/errno.h
index 8cbc07c1903e..93194fbb0a80 100644
--- a/tools/arch/parisc/include/uapi/asm/errno.h
+++ b/tools/arch/parisc/include/uapi/asm/errno.h
@@ -124,4 +124,6 @@
#define EHWPOISON 257 /* Memory page has hardware error */
+#define EFTYPE 258 /* Wrong file type for the intended operation */
+
#endif
diff --git a/tools/arch/sparc/include/uapi/asm/errno.h b/tools/arch/sparc/include/uapi/asm/errno.h
index 4a41e7835fd5..71940ec9130b 100644
--- a/tools/arch/sparc/include/uapi/asm/errno.h
+++ b/tools/arch/sparc/include/uapi/asm/errno.h
@@ -117,4 +117,6 @@
#define EHWPOISON 135 /* Memory page has hardware error */
+#define EFTYPE 136 /* Wrong file type for the intended operation */
+
#endif
diff --git a/tools/include/uapi/asm-generic/errno.h b/tools/include/uapi/asm-generic/errno.h
index 92e7ae493ee3..bd78e69e0a43 100644
--- a/tools/include/uapi/asm-generic/errno.h
+++ b/tools/include/uapi/asm-generic/errno.h
@@ -122,4 +122,6 @@
#define EHWPOISON 133 /* Memory page has hardware error */
+#define EFTYPE 134 /* Wrong file type for the intended operation */
+
#endif
--
2.53.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v4 2/4] kselftest/openat2: test for OPENAT2_REGULAR flag
2026-02-06 19:03 [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
2026-02-06 19:03 ` [PATCH v4 1/4] " Dorjoy Chowdhury
@ 2026-02-06 19:03 ` Dorjoy Chowdhury
2026-02-06 19:03 ` [PATCH v4 3/4] sparc/fcntl.h: convert O_* flag macros from hex to octal Dorjoy Chowdhury
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Dorjoy Chowdhury @ 2026-02-06 19:03 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-kernel, viro, brauner, jack, jlayton, chuck.lever,
alex.aring, arnd, adilger, mjguzik, smfrench
Just a happy path test.
Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
---
.../testing/selftests/openat2/openat2_test.c | 46 ++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/openat2/openat2_test.c b/tools/testing/selftests/openat2/openat2_test.c
index 0e161ef9e9e4..238de9cff291 100644
--- a/tools/testing/selftests/openat2/openat2_test.c
+++ b/tools/testing/selftests/openat2/openat2_test.c
@@ -320,8 +320,51 @@ void test_openat2_flags(void)
}
}
+#ifndef OPENAT2_REGULAR
+#define OPENAT2_REGULAR 040000000
+#endif
+
+#ifndef EFTYPE
+#define EFTYPE 134
+#endif
+
+void test_openat2_regular_flag(void)
+{
+ if (!openat2_supported) {
+ ksft_test_result_skip("Skipping %s as openat2 is not supported\n", __func__);
+ return;
+ }
+
+ struct open_how how = {
+ .flags = OPENAT2_REGULAR | O_RDONLY
+ };
+
+ int fd = sys_openat2(AT_FDCWD, "/dev/null", &how);
+
+ if (fd == -ENOENT) {
+ ksft_test_result_skip("Skipping %s as there is no /dev/null\n", __func__);
+ return;
+ }
+
+ if (fd != -EFTYPE) {
+ ksft_test_result_fail("openat2 should return EFTYPE\n");
+ return;
+ }
+
+ how.flags = OPENAT2_REGULAR | O_DIRECTORY | O_RDONLY;
+
+ fd = sys_openat2(AT_FDCWD, "/dev", &how);
+
+ if (fd < 0) {
+ ksft_test_result_fail("openat2 should open directory with both O_DIRECTORY and OPENAT2_REGULAR\n");
+ return;
+ }
+
+ ksft_test_result_pass("%s succeeded\n", __func__);
+}
+
#define NUM_TESTS (NUM_OPENAT2_STRUCT_VARIATIONS * NUM_OPENAT2_STRUCT_TESTS + \
- NUM_OPENAT2_FLAG_TESTS)
+ NUM_OPENAT2_FLAG_TESTS + 1)
int main(int argc, char **argv)
{
@@ -330,6 +373,7 @@ int main(int argc, char **argv)
test_openat2_struct();
test_openat2_flags();
+ test_openat2_regular_flag();
if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
ksft_exit_fail();
--
2.53.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v4 3/4] sparc/fcntl.h: convert O_* flag macros from hex to octal
2026-02-06 19:03 [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
2026-02-06 19:03 ` [PATCH v4 1/4] " Dorjoy Chowdhury
2026-02-06 19:03 ` [PATCH v4 2/4] kselftest/openat2: test for OPENAT2_REGULAR flag Dorjoy Chowdhury
@ 2026-02-06 19:03 ` Dorjoy Chowdhury
2026-02-06 19:03 ` [PATCH v4 4/4] mips/fcntl.h: " Dorjoy Chowdhury
2026-02-11 16:05 ` [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
4 siblings, 0 replies; 7+ messages in thread
From: Dorjoy Chowdhury @ 2026-02-06 19:03 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-kernel, viro, brauner, jack, jlayton, chuck.lever,
alex.aring, arnd, adilger, mjguzik, smfrench
Following the convention in include/uapi/asm-generic/fcntl.h and other
architecture specific arch/*/include/uapi/asm/fcntl.h files.
Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
---
arch/sparc/include/uapi/asm/fcntl.h | 36 ++++++++++++++---------------
1 file changed, 18 insertions(+), 18 deletions(-)
diff --git a/arch/sparc/include/uapi/asm/fcntl.h b/arch/sparc/include/uapi/asm/fcntl.h
index bb6e9fa94bc9..33ce58ec57f6 100644
--- a/arch/sparc/include/uapi/asm/fcntl.h
+++ b/arch/sparc/include/uapi/asm/fcntl.h
@@ -2,23 +2,23 @@
#ifndef _SPARC_FCNTL_H
#define _SPARC_FCNTL_H
-#define O_APPEND 0x0008
-#define FASYNC 0x0040 /* fcntl, for BSD compatibility */
-#define O_CREAT 0x0200 /* not fcntl */
-#define O_TRUNC 0x0400 /* not fcntl */
-#define O_EXCL 0x0800 /* not fcntl */
-#define O_DSYNC 0x2000 /* used to be O_SYNC, see below */
-#define O_NONBLOCK 0x4000
+#define O_APPEND 0000000010
+#define FASYNC 0000000100 /* fcntl, for BSD compatibility */
+#define O_CREAT 0000001000 /* not fcntl */
+#define O_TRUNC 0000002000 /* not fcntl */
+#define O_EXCL 0000004000 /* not fcntl */
+#define O_DSYNC 0000020000 /* used to be O_SYNC, see below */
+#define O_NONBLOCK 0000040000
#if defined(__sparc__) && defined(__arch64__)
-#define O_NDELAY 0x0004
+#define O_NDELAY 0000000004
#else
-#define O_NDELAY (0x0004 | O_NONBLOCK)
+#define O_NDELAY (0000000004 | O_NONBLOCK)
#endif
-#define O_NOCTTY 0x8000 /* not fcntl */
-#define O_LARGEFILE 0x40000
-#define O_DIRECT 0x100000 /* direct disk access hint */
-#define O_NOATIME 0x200000
-#define O_CLOEXEC 0x400000
+#define O_NOCTTY 0000100000 /* not fcntl */
+#define O_LARGEFILE 0001000000
+#define O_DIRECT 0004000000 /* direct disk access hint */
+#define O_NOATIME 0010000000
+#define O_CLOEXEC 0020000000
/*
* Before Linux 2.6.33 only O_DSYNC semantics were implemented, but using
* the O_SYNC flag. We continue to use the existing numerical value
@@ -32,12 +32,12 @@
*
* Note: __O_SYNC must never be used directly.
*/
-#define __O_SYNC 0x800000
+#define __O_SYNC 0040000000
#define O_SYNC (__O_SYNC|O_DSYNC)
-#define O_PATH 0x1000000
-#define __O_TMPFILE 0x2000000
-#define OPENAT2_REGULAR 0x4000000
+#define O_PATH 0100000000
+#define __O_TMPFILE 0200000000
+#define OPENAT2_REGULAR 0400000000
#define F_GETOWN 5 /* for sockets. */
#define F_SETOWN 6 /* for sockets. */
--
2.53.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v4 4/4] mips/fcntl.h: convert O_* flag macros from hex to octal
2026-02-06 19:03 [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
` (2 preceding siblings ...)
2026-02-06 19:03 ` [PATCH v4 3/4] sparc/fcntl.h: convert O_* flag macros from hex to octal Dorjoy Chowdhury
@ 2026-02-06 19:03 ` Dorjoy Chowdhury
2026-02-11 16:05 ` [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
4 siblings, 0 replies; 7+ messages in thread
From: Dorjoy Chowdhury @ 2026-02-06 19:03 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-kernel, viro, brauner, jack, jlayton, chuck.lever,
alex.aring, arnd, adilger, mjguzik, smfrench
Following the convention in include/uapi/asm-generic/fcntl.h and other
architecture specific arch/*/include/uapi/asm/fcntl.h files.
Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
---
arch/mips/include/uapi/asm/fcntl.h | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/mips/include/uapi/asm/fcntl.h b/arch/mips/include/uapi/asm/fcntl.h
index 0369a38e3d4f..6aa3f49df17e 100644
--- a/arch/mips/include/uapi/asm/fcntl.h
+++ b/arch/mips/include/uapi/asm/fcntl.h
@@ -11,15 +11,15 @@
#include <asm/sgidefs.h>
-#define O_APPEND 0x0008
-#define O_DSYNC 0x0010 /* used to be O_SYNC, see below */
-#define O_NONBLOCK 0x0080
-#define O_CREAT 0x0100 /* not fcntl */
-#define O_TRUNC 0x0200 /* not fcntl */
-#define O_EXCL 0x0400 /* not fcntl */
-#define O_NOCTTY 0x0800 /* not fcntl */
-#define FASYNC 0x1000 /* fcntl, for BSD compatibility */
-#define O_LARGEFILE 0x2000 /* allow large file opens */
+#define O_APPEND 0000010
+#define O_DSYNC 0000020 /* used to be O_SYNC, see below */
+#define O_NONBLOCK 0000200
+#define O_CREAT 0000400 /* not fcntl */
+#define O_TRUNC 0001000 /* not fcntl */
+#define O_EXCL 0002000 /* not fcntl */
+#define O_NOCTTY 0004000 /* not fcntl */
+#define FASYNC 0010000 /* fcntl, for BSD compatibility */
+#define O_LARGEFILE 0020000 /* allow large file opens */
/*
* Before Linux 2.6.33 only O_DSYNC semantics were implemented, but using
* the O_SYNC flag. We continue to use the existing numerical value
@@ -33,9 +33,9 @@
*
* Note: __O_SYNC must never be used directly.
*/
-#define __O_SYNC 0x4000
+#define __O_SYNC 0040000
#define O_SYNC (__O_SYNC|O_DSYNC)
-#define O_DIRECT 0x8000 /* direct disk access hint */
+#define O_DIRECT 0100000 /* direct disk access hint */
#define F_GETLK 14
#define F_SETLK 6
--
2.53.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support
2026-02-06 19:03 [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
` (3 preceding siblings ...)
2026-02-06 19:03 ` [PATCH v4 4/4] mips/fcntl.h: " Dorjoy Chowdhury
@ 2026-02-11 16:05 ` Dorjoy Chowdhury
2026-02-18 15:23 ` Dorjoy Chowdhury
4 siblings, 1 reply; 7+ messages in thread
From: Dorjoy Chowdhury @ 2026-02-11 16:05 UTC (permalink / raw)
To: linux-fsdevel, brauner, jlayton
Cc: linux-kernel, viro, jack, chuck.lever, alex.aring, arnd, adilger,
mjguzik, smfrench
On Sat, Feb 7, 2026 at 1:05 AM Dorjoy Chowdhury <dorjoychy111@gmail.com> wrote:
>
> Note that in v4, for now, I have returned -EINVAL from the atomic_open codepaths.
> I do want to make this new flag properly supported and proper api behavior, but
> last time I could not quite understand what should be done for the atomic_open
> codepaths. So to have a more concrete discussion, I have included the -EINVAL
> changes.
>
> Changes in v4:
> - changed O_REGULAR to OPENAT2_REGULAR
> - OPENAT2_REGULAR does not affect O_PATH
> - OPENAT2_REGULAR with O_DIRECTORY will open path for both directory or regular file
> - atomic_open codepaths updated to return -EINVAL when OPENAT2_REGULAR is set
> - 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/
>
> 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 am not quite sure if the semantics that I baked into the code for this
> O_REGULAR flag's behavior when combined with other flags like O_CREAT look
> good and if there are other places that need the checks. I can fixup my
> patch according to suggestions for improvement. I did some happy path testing
> and the O_REGULAR flag seems to work as intended.
>
> 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/9p/vfs_inode.c | 3 ++
> fs/9p/vfs_inode_dotl.c | 3 ++
> fs/ceph/file.c | 3 ++
> fs/fuse/dir.c | 3 ++
> fs/gfs2/inode.c | 3 ++
> fs/namei.c | 9 +++-
> fs/nfs/dir.c | 3 ++
> fs/nfs/file.c | 3 ++
> fs/open.c | 2 +-
> fs/smb/client/dir.c | 3 ++
> fs/vboxsf/dir.c | 3 ++
> 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 | 46 ++++++++++++++++++-
> 28 files changed, 138 insertions(+), 31 deletions(-)
>
> --
> 2.53.0
>
Hi,
I would appreciate some feedback on this patch series. I think there
are 2 things that need definite feedback.
1) I have defined OPENAT2_REGULAR to be in the 32-bit space. At first,
I tried to make it the 33rd bit but then realized, there are existing
structs like (struct open_flag and others) where the flag (or similar)
members are of type int or unsigned int which get passed over to lots
of places. So I ended up making it a flag in the 32-bit space. I guess
it's okay as it's not easy to add new flags to existing open syscalls
due to backward compatibility anyway.
2) For now, I am returning -EINVAL from the atomic_open codepaths.
What would be the proper way to handle this? And is there anything
needed for the file_operations.open codepaths (right now, do_open
already checks and returns errors for the new flag before we reach
file_operations.open)? I am a bit confused about the new flag and
network filesystems where obviously the new flag won't be recognized
by the server. So, if we want to handle the new flag properly in those
filesystems, does the flag need to be masked out? It's a bit hard for
me to understand the right thing that should be done as I am not
familiar with all the code so I appreciate any help and suggestions on
this.
Thanks.
Regards,
Dorjoy
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support
2026-02-11 16:05 ` [PATCH v4 0/4] openat2: new OPENAT2_REGULAR flag support Dorjoy Chowdhury
@ 2026-02-18 15:23 ` Dorjoy Chowdhury
0 siblings, 0 replies; 7+ messages in thread
From: Dorjoy Chowdhury @ 2026-02-18 15:23 UTC (permalink / raw)
To: linux-fsdevel, brauner, jlayton
Cc: linux-kernel, viro, jack, chuck.lever, alex.aring, arnd, adilger,
mjguzik, smfrench
On Wed, Feb 11, 2026 at 10:05 PM Dorjoy Chowdhury
<dorjoychy111@gmail.com> wrote:
>
> On Sat, Feb 7, 2026 at 1:05 AM Dorjoy Chowdhury <dorjoychy111@gmail.com> wrote:
> >
> > Note that in v4, for now, I have returned -EINVAL from the atomic_open codepaths.
> > I do want to make this new flag properly supported and proper api behavior, but
> > last time I could not quite understand what should be done for the atomic_open
> > codepaths. So to have a more concrete discussion, I have included the -EINVAL
> > changes.
> >
> > Changes in v4:
> > - changed O_REGULAR to OPENAT2_REGULAR
> > - OPENAT2_REGULAR does not affect O_PATH
> > - OPENAT2_REGULAR with O_DIRECTORY will open path for both directory or regular file
> > - atomic_open codepaths updated to return -EINVAL when OPENAT2_REGULAR is set
> > - 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/
> >
> > 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 am not quite sure if the semantics that I baked into the code for this
> > O_REGULAR flag's behavior when combined with other flags like O_CREAT look
> > good and if there are other places that need the checks. I can fixup my
> > patch according to suggestions for improvement. I did some happy path testing
> > and the O_REGULAR flag seems to work as intended.
> >
> > 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/9p/vfs_inode.c | 3 ++
> > fs/9p/vfs_inode_dotl.c | 3 ++
> > fs/ceph/file.c | 3 ++
> > fs/fuse/dir.c | 3 ++
> > fs/gfs2/inode.c | 3 ++
> > fs/namei.c | 9 +++-
> > fs/nfs/dir.c | 3 ++
> > fs/nfs/file.c | 3 ++
> > fs/open.c | 2 +-
> > fs/smb/client/dir.c | 3 ++
> > fs/vboxsf/dir.c | 3 ++
> > 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 | 46 ++++++++++++++++++-
> > 28 files changed, 138 insertions(+), 31 deletions(-)
> >
> > --
> > 2.53.0
> >
>
> Hi,
> I would appreciate some feedback on this patch series. I think there
> are 2 things that need definite feedback.
>
> 1) I have defined OPENAT2_REGULAR to be in the 32-bit space. At first,
> I tried to make it the 33rd bit but then realized, there are existing
> structs like (struct open_flag and others) where the flag (or similar)
> members are of type int or unsigned int which get passed over to lots
> of places. So I ended up making it a flag in the 32-bit space. I guess
> it's okay as it's not easy to add new flags to existing open syscalls
> due to backward compatibility anyway.
>
> 2) For now, I am returning -EINVAL from the atomic_open codepaths.
> What would be the proper way to handle this? And is there anything
> needed for the file_operations.open codepaths (right now, do_open
> already checks and returns errors for the new flag before we reach
> file_operations.open)? I am a bit confused about the new flag and
> network filesystems where obviously the new flag won't be recognized
> by the server. So, if we want to handle the new flag properly in those
> filesystems, does the flag need to be masked out? It's a bit hard for
> me to understand the right thing that should be done as I am not
> familiar with all the code so I appreciate any help and suggestions on
> this.
>
> Thanks.
>
> Regards,
> Dorjoy
Hi,
Gentle ping for review on this patch series. Thanks!
Regards,
Dorjoy
^ permalink raw reply [flat|nested] 7+ messages in thread