[CC list expanded a littlle] Andy (et al.) See comments below. On Wed, Aug 7, 2013 at 7:31 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > O_TMPFILE is new in Linux 3.11 > > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > --- > > This may have formatting issues -- I'm terrible at groff. > > If the corresponding linkat patch makes it in, it would probably be > worth documenting as well: > > https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git/commit/?h=for-linus&id=bb2314b47996491bbc5add73633905c3120b6268 > > man2/open.2 | 32 ++++++++++++++++++++++++++++++-- > 1 file changed, 30 insertions(+), 2 deletions(-) > > diff --git a/man2/open.2 b/man2/open.2 > index ef0f664..8bf56a0 100644 > --- a/man2/open.2 > +++ b/man2/open.2 > @@ -126,6 +126,7 @@ are > .BR O_EXCL , > .BR O_NOCTTY , > .BR O_NOFOLLOW , > +.BR O_TMPFILE , > .BR O_TRUNC , > and > .BR O_TTY_INIT . > @@ -226,11 +227,15 @@ described in > specifies the permissions to use in case a new file is created. > This argument must be supplied when > .B O_CREAT > +or > +.B O_TMPFILE > is specified in > .IR flags ; > -if > +if neither > .B O_CREAT > -is not specified, then > +nor > +.B O_TMPFILE > +is specified, then > .I mode > is ignored. > The effective permissions are modified by > @@ -284,6 +289,29 @@ The following symbolic constants are provided for > 00001 others have execute permission > .RE > .TP > +.BR O_TMPFILE " (Since Linux 3.11)" > +Create an unnamed temporary file. The pathname parameter specifies a > +directory; an unnamed inode will be created in that directory's > +filesystem. Anything written to the resulting file will be lost when > +the last fd is closed, unless the file is given a name. > +.RS > +.PP > +.B O_TMPFILE > +must be specified with one of > +.B O_RDWR > +or > +.B O_WRONLY > +and, optionally, > +.B O_EXCL. > +If O_EXCL is not specified, then > +.BR linkat (2) > +can be used to link the temporary file into the filesystem, making it > +permanent. > +.PP > +The mode parameter determines the inode's mode, as with > +.B O_CREAT. > +.RE > +.TP > .BR O_DIRECT " (Since Linux 2.4.10)" > Try to minimize cache effects of the I/O to and from this file. > In general this will degrade performance, but it is useful in See my reply to the thread started by Christoph Hellwig (https://lwn.net/Articles/562297/). I've taken your man-pages patch, and applied it in a branch. I tweaked the language and formatting a bit, and also added documentation of the EINVAL and EISDIR (ick!) error cases. As noted in the other thread, the API is questionable in the opinion of a few people. Maybe it will change, and this man-pages patch will need some further tweaking. If that doesn't happen, I'll merge it as is, at the time of the 3.11 stable release. Cheers, Michael -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
