diff options
author | Satyam Sharma <ssatyam@cse.iitk.ac.in> | 2007-05-08 04:18:58 -0400 |
---|---|---|
committer | Steven Whitehouse <swhiteho@redhat.com> | 2007-07-09 03:22:10 -0400 |
commit | 3168b0780d06ace875696f8a648d04d6089654e5 (patch) | |
tree | b93814b13155cce67432e1ed11bee58c9a5d5a50 /fs | |
parent | b524fe646c9a226a847e30ca1221dc22e952f16b (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')
-rw-r--r-- | fs/dlm/config.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/dlm/config.c b/fs/dlm/config.c index 822abdcd1434..5a3d390cc826 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) | |||
748 | 748 | ||
749 | static struct space *get_space(char *name) | 749 | static struct space *get_space(char *name) |
750 | { | 750 | { |
751 | struct config_item *i; | ||
752 | |||
751 | if (!space_list) | 753 | if (!space_list) |
752 | return NULL; | 754 | return NULL; |
753 | return to_space(config_group_find_obj(space_list, name)); | 755 | |
756 | down(&space_list->cg_subsys->su_sem); | ||
757 | i = config_group_find_obj(space_list, name); | ||
758 | up(&space_list->cg_subsys->su_sem); | ||
759 | |||
760 | return to_space(i); | ||
754 | } | 761 | } |
755 | 762 | ||
756 | static void put_space(struct space *sp) | 763 | static void put_space(struct space *sp) |
@@ -776,20 +783,20 @@ static struct comm *get_comm(int nodeid, struct sockaddr_storage *addr) | |||
776 | if (cm->nodeid != nodeid) | 783 | if (cm->nodeid != nodeid) |
777 | continue; | 784 | continue; |
778 | found = 1; | 785 | found = 1; |
786 | config_item_get(i); | ||
779 | break; | 787 | break; |
780 | } else { | 788 | } else { |
781 | if (!cm->addr_count || | 789 | if (!cm->addr_count || |
782 | memcmp(cm->addr[0], addr, sizeof(*addr))) | 790 | memcmp(cm->addr[0], addr, sizeof(*addr))) |
783 | continue; | 791 | continue; |
784 | found = 1; | 792 | found = 1; |
793 | config_item_get(i); | ||
785 | break; | 794 | break; |
786 | } | 795 | } |
787 | } | 796 | } |
788 | up(&clusters_root.subsys.su_sem); | 797 | up(&clusters_root.subsys.su_sem); |
789 | 798 | ||
790 | if (found) | 799 | if (!found) |
791 | config_item_get(i); | ||
792 | else | ||
793 | cm = NULL; | 800 | cm = NULL; |
794 | return cm; | 801 | return cm; |
795 | } | 802 | } |