On 3/14/22 19:02, Pádraig Brady wrote: > On 14/03/2022 13:24, Alejandro Colomar (man-pages) wrote: >> On 3/10/22 14:46, Pádraig Brady wrote: >>> Subject: [PATCH] fix descriptions for AT_NO_AUTOMOUNT >>> >>> Don't mention AT_NO_AUTOMOUNT for fstatat.2 >>> as it's implied since v4.11-rc7-14-gdeccf497d804 >> >> Even though it's implied, since code may pass it, >> and especially code written based on the old manual page, >> it would be good to keep the paragraph in fstatat.2, >> even if the text is replaced by something like >> "Before Linux x.xx, this flag was ignored. >> After Linux y.yy, this flag is implied." >> >> Does it make sense to you? > > Yes good point. > I went through the git history and the summary is fstatat() > honored the flag since 2.6.38, > ignored the flag since 3.1, > implied the flag since 4.11, > > I'll add that info to fstatat(2), and the details to the commit message. > >>> Don't mention commit v4.13-9318-g42f461482178 as it was reverted >> >> Please also mention v4.15-rc1-50-g5d38f049cee1 as the commit in which it >> was reverted. >> Since it was present in some kernel releases, we might want to mention >> it in the manual page? > > Well since the flag for fstatat() doesn't change anything since 3.1 > it's probably best not to mention this old, short lived, and very > specific info. Okay. > >>> Mention that stat(), lstat(), and fstatat() >>> imply AT_NO_AUTOMOUNT, on the statx.2 man page >> >> Please sign the patch with "Signed-off-by: ..." >> <https://www.kernel.org/doc/man-pages/patches.html> > > Done in the attached. Please send the patch inline (or both inline and attached), if you don't mind. However, if it's a big hassle for you, I can apply it from an attachment. > > thanks! > Pádraig --- > > Subject: [PATCH] fix descriptions for AT_NO_AUTOMOUNT > > 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> Makes sense to me. But see a few minor comments below. Thanks, Alex > --- > man2/stat.2 | 31 +++---------------------------- > man2/statx.2 | 18 +++++++++++++++--- > 2 files changed, 18 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..d4e638756 100644 > --- a/man2/statx.2 > +++ b/man2/statx.2 > @@ -195,11 +195,23 @@ 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. Weird break point there. I see that it was like that in existing code, but please fix it :) > +.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 () , s/() ,/(2),/ > +.BR lstat () , s/() ,/(2),/ > +and > +.BR fstatat () s/()/(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 > -- > 2.31.1 > -- Alejandro Colomar Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/
