On Mon, Sep 19, 2011 at 07:08:17AM +0200, Michael Kerrisk wrote:
> Hi Josef (Dave C, please also note comments below),
>
> On Mon, Nov 15, 2010 at 6:07 PM, Josef Bacik <josef@xxxxxxxxxx> wrote:
> > This patch adds the relevant documenation for using fallocate with the
> > FALLOC_FL_PUNCH_HOLE mode. This information comes from the implementation of
> > FALLOC_FL_PUNCH_HOLE that I've posted along with this man page update to outline
> > the definition for hole punching. Obviously this patch is dependant upon the
> > current implementation being accepted. Thanks,
> >
> > Signed-off-by: Josef Bacik <josef@xxxxxxxxxx>
> > ---
> > man2/fallocate.2 | 15 ++++++++++++---
> > 1 files changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/man2/fallocate.2 b/man2/fallocate.2
> > index 42eefbd..1b28916 100644
> > --- a/man2/fallocate.2
> > +++ b/man2/fallocate.2
> > @@ -31,9 +31,8 @@ bytes.
> >
> > The
> > .I mode
> > -argument determines the operation to be performed on the given range.
> > -Currently only one flag is supported for
> > -.IR mode :
> > +argument determines the operation to be performed on the given range, the
> > +value can be one of the following:
> > .TP
> > .B FALLOC_FL_KEEP_SIZE
> > This flag allocates and initializes to zero the disk space
> > @@ -50,6 +49,16 @@ the file size (as reported by
> > .BR stat (2))
> > even if it is less than
> > .IR offset + len .
> > +.TP
> > +.B FALLOC_FL_PUNCH_HOLE
> > +This flag de-allocates the disk space within the range specified by
> > +.I offset
> > +and
> > +.IR len .
> > +This call preserves the file size (as reported by
> > +.BR stat (2)),
> > +the only change will be to the amount of space used by the file. After a
> > +successful call, subsequent reads from this range will return 0's.
> > .\"
> > .\" Note from Amit Arora:
> > .\" There were few more flags which were discussed, but none of
> > --
> > 1.6.6.1
>
> Thanks for this patch. As noted in another mail, Lucian also sent a
> patch for FALLOC_FL_PUNCH_HOLE, and I applied his patch first, and
> then added some pieces from yours, as well as some of my own edits.
>
> However, the addition of a second class of operation to the man page
> made it clear that some significant restructuring of the page is
> required. So I substantially reworked the page, including the
> preexisting material on the default "file allocation" operation (Dave
> C please note).
>
> Josef, Lucian, could I ask you to check ("man -l <file>") the final
> text (below) for FALLOC_FL_PUNCH_HOLE (including the EPERM error under
> ERRORS)?
>
> Dave, could I ask you to review my reworked text for the "Allocating
> disk space" subsection?
Looks OK to me.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
--
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
