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| author | Yan, Zheng <zyan@redhat.com> | 2015-01-09 12:00:42 +0300 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2015-02-19 13:31:38 +0300 |
| commit | 86d8f67b26a8b30228b5177b7e594bbc89798a23 (patch) | |
| tree | 8d2c95e94f1718806d0aed91854394ec5cfabe5b | |
| parent | c4d4a582c538e890f09c338bc3063c28dfdc9ae5 (diff) | |
| download | linux-86d8f67b26a8b30228b5177b7e594bbc89798a23.tar.xz | |
ceph: avoid block operation when !TASK_RUNNING (ceph_mdsc_close_sessions)
use an atomic variable to track number of sessions, this can avoid block
operation inside wait loops.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
| -rw-r--r-- | fs/ceph/mds_client.c | 13 | ||||
| -rw-r--r-- | fs/ceph/mds_client.h | 1 |
2 files changed, 5 insertions, 9 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index fdf5cc8737ee..c90ca99331be 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -480,6 +480,7 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc, mdsc->max_sessions = newmax; } mdsc->sessions[mds] = s; + atomic_inc(&mdsc->num_sessions); atomic_inc(&s->s_ref); /* one ref to sessions[], one to caller */ ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds, @@ -503,6 +504,7 @@ static void __unregister_session(struct ceph_mds_client *mdsc, mdsc->sessions[s->s_mds] = NULL; ceph_con_close(&s->s_con); ceph_put_mds_session(s); + atomic_dec(&mdsc->num_sessions); } /* @@ -3328,6 +3330,7 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) init_waitqueue_head(&mdsc->session_close_wq); INIT_LIST_HEAD(&mdsc->waiting_for_map); mdsc->sessions = NULL; + atomic_set(&mdsc->num_sessions, 0); mdsc->max_sessions = 0; mdsc->stopping = 0; init_rwsem(&mdsc->snap_rwsem); @@ -3479,17 +3482,9 @@ void ceph_mdsc_sync(struct ceph_mds_client *mdsc) */ static bool done_closing_sessions(struct ceph_mds_client *mdsc) { - int i, n = 0; - if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN) return true; - - mutex_lock(&mdsc->mutex); - for (i = 0; i < mdsc->max_sessions; i++) - if (mdsc->sessions[i]) - n++; - mutex_unlock(&mdsc->mutex); - return n == 0; + return atomic_read(&mdsc->num_sessions) == 0; } /* diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index a87b92f500bb..1875b5d985c6 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -273,6 +273,7 @@ struct ceph_mds_client { struct list_head waiting_for_map; struct ceph_mds_session **sessions; /* NULL for mds if no session */ + atomic_t num_sessions; int max_sessions; /* len of s_mds_sessions */ int stopping; /* true if shutting down */ |