git: 0f12c3cd0ddb - main - vfs_default.c: Add _PC_HAS_NAMEDATTR pathconf name

The branch main has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=0f12c3cd0ddb9b230f21187f7e8a48964cdaf744

commit 0f12c3cd0ddb9b230f21187f7e8a48964cdaf744
Author:     Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2025-05-04 22:06:01 +0000
Commit:     Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2025-05-04 22:11:06 +0000

    vfs_default.c: Add _PC_HAS_NAMEDATTR pathconf name
    
    Commit f61844833ee8 changes the semantics of O_NAMEDATTR so
    that a named attribute directory will be created if it
    does not already exist. As such, an open(2) without
    O_CREAT cannot be used to test to see if one exists.
    
    This patch adds a new pathconf name _PC_HAS_NAMEDATTR,
    which returns 1 if one or more named attributes are associated
    with the file. This is similar to Solaris's _PC_XATTR_EXISTS.
    A return of 0 means that there are none, so there.
    is no need to open(2) the named attribute directory.
    This allows applications to avoid creating unnecessary named
    attribute directories when the application only wishes to read
    named attributes and not create them.
    
    It is also useful for the NFSv4 server, so that it can reply with
    a correct named_attr attribute.
    
    Reviewed by:    kib
    Differential Revision:  https://reviews.freebsd.org/D50140
    Fixes:  2ec2ba7e232d ("vfs: Add VFS/syscall support for Solaris style extended attributes")
---
 sys/kern/vfs_default.c | 1 +
 sys/sys/unistd.h       | 1 +
 2 files changed, 2 insertions(+)

diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
index c76fc9f9dc59..be49c0887609 100644
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -452,6 +452,7 @@ vop_stdpathconf(struct vop_pathconf_args *ap)
 		case _PC_INF_PRESENT:
 		case _PC_MAC_PRESENT:
 		case _PC_NAMEDATTR_ENABLED:
+		case _PC_HAS_NAMEDATTR:
 			*ap->a_retval = 0;
 			return (0);
 		default:
diff --git a/sys/sys/unistd.h b/sys/sys/unistd.h
index 59cef241754a..f5caea2e3919 100644
--- a/sys/sys/unistd.h
+++ b/sys/sys/unistd.h
@@ -155,6 +155,7 @@
 #define	_PC_ACL_NFS4		64
 #define	_PC_DEALLOC_PRESENT	65
 #define	_PC_NAMEDATTR_ENABLED	66
+#define	_PC_HAS_NAMEDATTR	67
 #endif
 
 /* From OpenSolaris, used by SEEK_DATA/SEEK_HOLE. */