libceph: fix log output race condition in OSD client

OSD client logging has a problem in get_osd() and put_osd().
For one logging output refcount_read() is called twice. If recount
value changes between both calls logging output is not consistent.

This patch prints out only the resulting value.

[ idryomov: don't make the log messages more verbose ]

Signed-off-by: Simon Buttgereit <simon.buttgereit@tu-ilmenau.de>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Author: HolyShitMan

net/ceph/osd_client.c

@@ -1280,8 +1280,7 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
 static struct ceph_osd *get_osd(struct ceph_osd *osd)
 {
 	if (refcount_inc_not_zero(&osd->o_ref)) {
-		dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,
-		     refcount_read(&osd->o_ref));
+		dout("get_osd %p -> %d\n", osd, refcount_read(&osd->o_ref));
 		return osd;
 	} else {
 		dout("get_osd %p FAIL\n", osd);
@@ -1291,8 +1290,7 @@ static struct ceph_osd *get_osd(struct ceph_osd *osd)
 
 static void put_osd(struct ceph_osd *osd)
 {
-	dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),
-	     refcount_read(&osd->o_ref) - 1);
+	dout("put_osd %p -> %d\n", osd, refcount_read(&osd->o_ref) - 1);
 	if (refcount_dec_and_test(&osd->o_ref)) {
 		osd_cleanup(osd);
 		kfree(osd);