[dm-devel] [PATCH 2/5] libmultipath: change reservation_key to a uint64_t
Martin Wilck
mwilck at suse.com
Fri Sep 8 21:09:17 UTC 2017
On Fri, 2017-09-08 at 13:45 -0500, Benjamin Marzinski wrote:
> The reservation key is currently being stored as any array of 8
> unsigned
> chars. This is exactly the same in-memory representation as a big
> endian 64 bit integer. However, the code for dealing with a big
> endian
> 64 bit integer is much simpler, so switch to use that instead.
>
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
> libmpathpersist/mpath_persist.c | 23 +++++++----------------
> libmultipath/byteorder.h | 36
> ++++++++++++++++++++++++++++++++++++
> libmultipath/config.c | 3 ---
> libmultipath/config.h | 6 ++++--
> libmultipath/dict.c | 31 ++++---------------------------
> libmultipath/propsel.c | 6 +++---
> libmultipath/structs.h | 5 ++++-
> multipathd/main.c | 23 +++++------------------
> 8 files changed, 63 insertions(+), 70 deletions(-)
> create mode 100644 libmultipath/byteorder.h
>
>
> char * prio_name;
> char * prio_args;
> - unsigned char * reservation_key;
> + uint64_t reservation_key; /* stored in big-endian format */
I would prefer if you could encapsulate this into a type that can't be
implicitly converted to an int, such as
struct res_key {
uint64_t _v;
} reservation_key;
together with macros like
#define reskey_to_uint64(r) be64_to_cpu((r)->_v)
#define set_reskey_from_uint64(r, x) do { (r)->_v = (x); } while (0)
Using be64_to_cpu is all too easily forgotten, which leads to nasty
bugs.
Apart from that, ack.
--
Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
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