2009-11-21 15:53:13

by Julia Lawall

Subject: [PATCH] fs/ceph: Move a dereference below a NULL test

From: Julia Lawall <[email protected]>

If the NULL test is necessary, then the dereference should be moved below
the NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/).

// <smpl>
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
... when != E
when != i
if (E == NULL) S
+ i = E->fld;
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
fs/ceph/osd_client.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff -u -p a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -1244,11 +1244,12 @@ int ceph_osdc_writepages(struct ceph_osd
static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
{
struct ceph_osd *osd = con->private;
- struct ceph_osd_client *osdc = osd->o_osdc;
+ struct ceph_osd_client *osdc;
int type = le16_to_cpu(msg->hdr.type);

if (!osd)
return;
+ osdc = osd->o_osdc;

switch (type) {
case CEPH_MSG_OSD_MAP:

2009-11-21 21:03:33

by Sage Weil

Subject: Re: [ceph-devel] [PATCH] fs/ceph: Move a dereference below a NULL test

On Sat, 21 Nov 2009, Julia Lawall wrote:

> From: Julia Lawall <[email protected]>
>
> If the NULL test is necessary, then the dereference should be moved below
> the NULL test.

I've applied this (and the previous patch) to the ceph tree.

Thanks!
sage


>
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/).
>
> // <smpl>
> @@
> type T;
> expression E;
> identifier i,fld;
> statement S;
> @@
>
> - T i = E->fld;
> + T i;
> ... when != E
> when != i
> if (E == NULL) S
> + i = E->fld;
> // </smpl>
>
> Signed-off-by: Julia Lawall <[email protected]>
>
> ---
> fs/ceph/osd_client.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff -u -p a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
> --- a/fs/ceph/osd_client.c
> +++ b/fs/ceph/osd_client.c
> @@ -1244,11 +1244,12 @@ int ceph_osdc_writepages(struct ceph_osd
> static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
> {
> struct ceph_osd *osd = con->private;
> - struct ceph_osd_client *osdc = osd->o_osdc;
> + struct ceph_osd_client *osdc;
> int type = le16_to_cpu(msg->hdr.type);
>
> if (!osd)
> return;
> + osdc = osd->o_osdc;
>
> switch (type) {
> case CEPH_MSG_OSD_MAP:
>
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