aboutsummaryrefslogtreecommitdiffstats
path: root/fs/dlm/config.c
diff options
context:
space:
mode:
authorSatyam Sharma <ssatyam@cse.iitk.ac.in>2007-05-08 09:18:58 +0100
committerSteven Whitehouse <swhiteho@redhat.com>2007-07-09 08:22:10 +0100
commit3168b0780d06ace875696f8a648d04d6089654e5 (patch)
treeb93814b13155cce67432e1ed11bee58c9a5d5a50 /fs/dlm/config.c
parentb524fe646c9a226a847e30ca1221dc22e952f16b (diff)
[DLM] fix a couple of races
Fix two races in fs/dlm/config.c: (1) Grab the configfs subsystem semaphore before calling config_group_find_obj() in get_space(). This solves a potential race between get_space() and concurrent mkdir(2) or rmdir(2). (2) Grab a reference on the found config_item _while_ holding the configfs subsystem semaphore in get_comm(), and not after it. This solves a potential race between get_comm() and concurrent rmdir(2). Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/dlm/config.c')
-rw-r--r--fs/dlm/config.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 822abdcd143..5a3d390cc82 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -748,9 +748,16 @@ static ssize_t node_weight_write(struct node *nd, const char *buf, size_t len)
static struct space *get_space(char *name)
{
+ struct config_item *i;
+
if (!space_list)
return NULL;
- return to_space(config_group_find_obj(space_list, name));
+
+ down(&space_list->cg_subsys->su_sem);
+ i = config_group_find_obj(space_list, name);
+ up(&space_list->cg_subsys->su_sem);
+
+ return to_space(i);
}
static void put_space(struct space *sp)
@@ -776,20 +783,20 @@ static struct comm *get_comm(int nodeid, struct sockaddr_storage *addr)
if (cm->nodeid != nodeid)
continue;
found = 1;
+ config_item_get(i);
break;
} else {
if (!cm->addr_count ||
memcmp(cm->addr[0], addr, sizeof(*addr)))
continue;
found = 1;
+ config_item_get(i);
break;
}
}
up(&clusters_root.subsys.su_sem);
- if (found)
- config_item_get(i);
- else
+ if (!found)
cm = NULL;
return cm;
}