fstatat(..., AT_NO_AUTOMOUNT) has had the following history in Linux:
v2.6.37-7314-g6f45b65672c8
add AT_NO_AUTOMOUNT and fstatat honors it
v3.1-rc7-68-gb6c8069d3577
ignore AT_NO_AUTOMOUNT since default operation now less eagerly mounts
v4.10-11255-ga528d35e8bfc
adds statx which reinstated 2.6.38 behavior for fstatat (not released)
v4.11-rc7-14-gdeccf497d804
adjust fstatat so that AT_NO_AUTOMOUNT always specified (to statx)
* man2/stat.2:
Adjust AT_NO_AUTOMOUNT description for fstatat.2 as per the above,
to indicate AT_NO_AUTOMOUNT should be avoided with fstatat() since
it's ignored since 3.1 and implied since 4.11.
Don't mention commit v4.13-9318-g42f461482178 as it was reverted,
and moot anyway since we can't adjust AT_NO_AUTOMOUNT since 3.1.
* man2/statx.2:
Mention that stat(), lstat(), and fstatat() imply AT_NO_AUTOMOUNT.
Signed-off-by: Pádraig Brady <P@xxxxxxxxxxxxxx>
---
man2/stat.2 | 31 +++----------------------------
man2/statx.2 | 17 ++++++++++++++---
2 files changed, 17 insertions(+), 31 deletions(-)
diff --git a/man2/stat.2 b/man2/stat.2
index 016c1f47d..9000b2ca6 100644
--- a/man2/stat.2
+++ b/man2/stat.2
@@ -319,34 +319,9 @@ to obtain its definition.
.TP
.BR AT_NO_AUTOMOUNT " (since Linux 2.6.38)"
Don't automount the terminal ("basename") component of
-.I pathname
-if it is a directory that is an automount point.
-This allows the caller to gather attributes of an automount point
-(rather than the location it would mount).
-Since Linux 4.14,
-.\" commit 42f46148217865a545e129612075f3d828a2c4e4
-also don't instantiate a nonexistent name in an
-on-demand directory such as used for automounter indirect maps.
-This
-flag has no effect if the mount point has already been mounted over.
-.IP
-Both
-.BR stat ()
-and
-.BR lstat ()
-act as though
-.B AT_NO_AUTOMOUNT
-was set.
-.IP
-The
-.B AT_NO_AUTOMOUNT
-can be used in tools that scan directories
-to prevent mass-automounting of a directory of automount points.
-.IP
-This flag is Linux-specific; define
-.B _GNU_SOURCE
-.\" Before glibc 2.16, defining _ATFILE_SOURCE sufficed
-to obtain its definition.
+.I pathname.
+Since Linux 3.1 this flag is ignored.
+Since Linux 4.11 this flag is implied.
.TP
.B AT_SYMLINK_NOFOLLOW
If
diff --git a/man2/statx.2 b/man2/statx.2
index 04b3e5075..e579523af 100644
--- a/man2/statx.2
+++ b/man2/statx.2
@@ -195,11 +195,22 @@ Don't automount the terminal ("basename") component of
if it is a directory that is an automount point.
This allows the caller to gather attributes of an automount point
(rather than the location it would mount).
-This flag can be used in tools that scan directories
-to prevent mass-automounting of a directory of automount points.
+This flag has no effect if the mount point has already been mounted over.
+.IP
The
.B AT_NO_AUTOMOUNT
-flag has no effect if the mount point has already been mounted over.
+flag can be used in tools that scan directories
+to prevent mass-automounting of a directory of automount points.
+.IP
+All of
+.BR stat (2),
+.BR lstat (2),
+and
+.BR fstatat (2)
+act as though
+.B AT_NO_AUTOMOUNT
+was set.
+.IP
This flag is Linux-specific; define
.B _GNU_SOURCE
.\" Before glibc 2.16, defining _ATFILE_SOURCE sufficed
--
2.34.1
