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Re: Is jdm_delete_filehandle part of a public API?

To: Eric Sandeen <sandeen@xxxxxxxxxxx>
Subject: Re: Is jdm_delete_filehandle part of a public API?
From: Mark Tinguely <tinguely@xxxxxxx>
Date: Tue, 29 Jul 2014 15:54:03 -0500
Cc: Eric Sandeen <sandeen@xxxxxxxxxx>, xfs-oss <xfs@xxxxxxxxxxx>
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <53D801B1.5000300@xxxxxxxxxxx>
References: <53D7DA7F.2040706@xxxxxxxxxx> <53D7E56C.8020103@xxxxxxx> <53D7FE32.3080807@xxxxxxx> <53D801B1.5000300@xxxxxxxxxxx>
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On 07/29/14 15:18, Eric Sandeen wrote:
On 7/29/14, 3:04 PM, Mark Tinguely wrote:
On 07/29/14 13:18, Mark Tinguely wrote:
On 07/29/14 12:31, Eric Sandeen wrote:
I was cleaning up xfsprogs to plug some leaks, and wanted to use
jdm_delete_filehandle(). I noticed that it has an "hlen" argument which
is unused.

Can we remove that, or is this part of a public API? It's not in any
manpage (or even called anywhere in xfsprogs/xfstests/xfsdump/dmapi)
but it is in a public header...

anyone know?

If needed I guess I can just call it with hlen==0, but that seems odd.

Thanks,
-Eric

The first thing that comes to mind is maybe they trying to distinguish
between a fshandle or handle. Or they we trying to be consistent with
the allocation calls.

The libhandle free_handle has the same calling parameters. It also does
nothing with the length. That we cannot change without breaking existing
code.

I will look/ask around.

--Mark.

Looks like the code is pretty sloppy with freeing the handles.

yeah, that's what I was going to fix :)

Best guess is jdm_delete_filehandle() and free_handle are trying to
keep the API similar to DMAPI. The DMAPI handle free routine,
dm_handle_free(), also has a second length parameter that is not used
in the library.

The code example that I saw are similar to the use in xfsdump, where
the length used in the free comes from the handle creation/conversion
routine.

yup but I don't think jdm_getfshandle has anything similar does it?

nope. Do you know why there is a jdm and a libhandle libs?


Since the xfsprogs do not open handles with calls that provide a
length. How about FSHANDLE_SZ and FILEHANDLE_SZ depending on if it is
a xfs_fshandle or xfs_handle?

*shrug* it's not used anyway - I'm not sure why we'd need to invent a
macro to pass in only to have it ignored.  Is there any advantage to that?

never mind... handles are opaque and we should not be defining a size.

I did the grep and saw that the sizes were defined and thought they were better than nothing. I did not not realize that the defines are are in jdm.c and not a header file. In that case, nothing is better than adding a define for an opaque item.

-Eric

--Mark.

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