LU-16796 obdclass: Change struct jobid_pid_map to use refcount_t

This patch changes struct jobid_pid_map to use
refcount_t(kref) instead of atomic_t

Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: Ia3458d5605a8cff2bb65476495c321fa98cf01dc
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51747
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/obdclass/jobid.c b/lustre/obdclass/jobid.c
index 437d714..e72280b 100644 (file)
--- a/lustre/obdclass/jobid.c
+++ b/lustre/obdclass/jobid.c
@@ -60,7 +60,7 @@ struct jobid_pid_map {
        spinlock_t              jp_lock; /* protects jp_jobid */
        char                    jp_jobid[LUSTRE_JOBID_SIZE];
        unsigned int            jp_joblen;
-       atomic_t                jp_refcount;
+       struct kref             jp_refcount;
        pid_t                   jp_pid;
 };
 
@@ -447,13 +447,13 @@ static int jobid_should_free_item(void *obj, void *data)
                return 0;
 
        if (jobid == NULL) {
-               WARN_ON_ONCE(atomic_read(&pidmap->jp_refcount) != 1);
+               WARN_ON_ONCE(kref_read(&pidmap->jp_refcount) != 1);
                return 1;
        }
 
        spin_lock(&pidmap->jp_lock);
        /* prevent newly inserted items from deleting */
-       if (jobid[0] == '\0' && atomic_read(&pidmap->jp_refcount) == 1)
+       if (jobid[0] == '\0' && kref_read(&pidmap->jp_refcount) == 1)
                rc = 1;
        else if (ktime_get_real_seconds() - pidmap->jp_time > DELETE_INTERVAL)
                rc = 1;
@@ -561,7 +561,7 @@ static int jobid_get_from_cache(char *jobid, size_t joblen)
                 * hash list, init @jp_refcount as 1 to make sure memory
                 * could be not freed during access.
                 */
-               atomic_set(&pidmap->jp_refcount, 1);
+               kref_init(&pidmap->jp_refcount);
 
                /*
                 * Add the newly created map to the hash, on key collision we
@@ -819,7 +819,16 @@ static void jobid_get(struct cfs_hash *hs, struct hlist_node *hnode)
 
        pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
 
-       atomic_inc(&pidmap->jp_refcount);
+       kref_get(&pidmap->jp_refcount);
+}
+
+static void jobid_put_locked_free(struct kref *kref)
+{
+       struct jobid_pid_map *pidmap = container_of(kref, struct jobid_pid_map,
+                                                   jp_refcount);
+
+       CDEBUG(D_INFO, "Freeing: %d->%s\n", pidmap->jp_pid, pidmap->jp_jobid);
+       OBD_FREE_PTR(pidmap);
 }
 
 static void jobid_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
@@ -830,13 +839,8 @@ static void jobid_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
                return;
 
        pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
-       LASSERT(atomic_read(&pidmap->jp_refcount) > 0);
-       if (atomic_dec_and_test(&pidmap->jp_refcount)) {
-               CDEBUG(D_INFO, "Freeing: %d->%s\n",
-                      pidmap->jp_pid, pidmap->jp_jobid);
-
-               OBD_FREE_PTR(pidmap);
-       }
+       LASSERT(kref_read(&pidmap->jp_refcount) > 0);
+       kref_put(&pidmap->jp_refcount, jobid_put_locked_free);
 }
 
 static struct cfs_hash_ops jobid_hash_ops = {