From: Chengguang Xu <cgxu519@gmx.com>
Date: Tue, 13 Mar 2018 23:01:07 +0800
Subject: ceph: optimize mds session register
Git-commit: 47474d0b011bb385719e91a60bb9ff7649d66526
Patch-mainline: v4.17-rc1
References: bsc#1089115
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>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
fs/ceph/mds_client.c | 36 +++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -447,6 +447,25 @@ static struct ceph_mds_session *register
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;
@@ -475,23 +494,6 @@ static struct ceph_mds_session *register
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 */