ceph: optimize mds session register

Do memory allocation first, so that avoid unnecessary
initialization of newly allocated session in error case.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Chengguang Xu 2018-03-13 23:01:07 +08:00 committed by Ilya Dryomov
parent 57a35dfb52
commit 47474d0b01

View File

@ -448,6 +448,25 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
s = kzalloc(sizeof(*s), GFP_NOFS);
if (!s)
return ERR_PTR(-ENOMEM);
if (mds >= mdsc->max_sessions) {
int newmax = 1 << get_count_order(mds + 1);
struct ceph_mds_session **sa;
dout("%s: realloc to %d\n", __func__, newmax);
sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
if (!sa)
goto fail_realloc;
if (mdsc->sessions) {
memcpy(sa, mdsc->sessions,
mdsc->max_sessions * sizeof(void *));
kfree(mdsc->sessions);
}
mdsc->sessions = sa;
mdsc->max_sessions = newmax;
}
dout("%s: mds%d\n", __func__, mds);
s->s_mdsc = mdsc;
s->s_mds = mds;
s->s_state = CEPH_MDS_SESSION_NEW;
@ -476,23 +495,6 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
INIT_LIST_HEAD(&s->s_cap_releases);
INIT_LIST_HEAD(&s->s_cap_flushing);
dout("register_session mds%d\n", mds);
if (mds >= mdsc->max_sessions) {
int newmax = 1 << get_count_order(mds+1);
struct ceph_mds_session **sa;
dout("register_session realloc to %d\n", newmax);
sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
if (!sa)
goto fail_realloc;
if (mdsc->sessions) {
memcpy(sa, mdsc->sessions,
mdsc->max_sessions * sizeof(void *));
kfree(mdsc->sessions);
}
mdsc->sessions = sa;
mdsc->max_sessions = newmax;
}
mdsc->sessions[mds] = s;
atomic_inc(&mdsc->num_sessions);
refcount_inc(&s->s_ref); /* one ref to sessions[], one to caller */