LU-9306 kuc: initialize kkuc_groups at module init time

Some kkuc functions use kkuc_groups[group].next == NULL to test for an
empty group list. This is incorrect if the group was previously added
to but not empty. Remove all next == NULL tests and use module load
time initialization of the kkuc_groups array.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I0d6af7b8584f18d1dc03873993d6aac55b1677a9
Reviewed-on: https://review.whamcloud.com/26883
Tested-by: Jenkins
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Henri Doreau <henri.doreau@cea.fr>
Reviewed-by: Quentin Bouget <quentin.bouget@cea.fr>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/include/lustre_kernelcomm.h b/lustre/include/lustre_kernelcomm.h
index 1d6efda..cb8a29f 100644 (file)
--- a/lustre/include/lustre_kernelcomm.h
+++ b/lustre/include/lustre_kernelcomm.h
@@ -44,6 +44,7 @@
 typedef int (*libcfs_kkuc_cb_t)(void *data, void *cb_arg);
 
 /* Kernel methods */
+void libcfs_kkuc_init(void);
 int libcfs_kkuc_msg_put(struct file *fp, void *payload);
 int libcfs_kkuc_group_put(int group, void *payload);
 int libcfs_kkuc_group_add(struct file *fp, int uid, int group,

diff --git a/lustre/obdclass/class_obd.c b/lustre/obdclass/class_obd.c
index 75c5dab..17b0b9f 100644 (file)
--- a/lustre/obdclass/class_obd.c
+++ b/lustre/obdclass/class_obd.c
@@ -43,6 +43,7 @@
 #include <obd_class.h>
 #include <lnet/lnetctl.h>
 #include <lustre_debug.h>
+#include <lustre_kernelcomm.h>
 #include <lprocfs_status.h>
 #include <lustre_ver.h>
 #include <cl_object.h>
@@ -492,6 +493,8 @@ static int __init obdclass_init(void)
 
        LCONSOLE_INFO("Lustre: Build Version: "LUSTRE_VERSION_STRING"\n");
 
+       libcfs_kkuc_init();
+
        err = obd_init_checks();
        if (err == -EOVERFLOW)
                return err;

diff --git a/lustre/obdclass/kernelcomm.c b/lustre/obdclass/kernelcomm.c
index cb52660..9e4b84c 100644 (file)
--- a/lustre/obdclass/kernelcomm.c
+++ b/lustre/obdclass/kernelcomm.c
@@ -105,10 +105,23 @@ struct kkuc_reg {
        char             kr_data[0];
 };
 
-static struct list_head kkuc_groups[KUC_GRP_MAX+1] = {};
+static struct list_head kkuc_groups[KUC_GRP_MAX + 1];
 /* Protect message sending against remove and adds */
 static DECLARE_RWSEM(kg_sem);
 
+static inline bool libcfs_kkuc_group_is_valid(int group)
+{
+       return 0 <= group && group < ARRAY_SIZE(kkuc_groups);
+}
+
+void libcfs_kkuc_init(void)
+{
+       int group;
+
+       for (group = 0; group < ARRAY_SIZE(kkuc_groups); group++)
+               INIT_LIST_HEAD(&kkuc_groups[group]);
+}
+
 /** Add a receiver to a broadcast group
  * @param filp pipe to write into
  * @param uid identifier for this receiver
@@ -120,7 +133,7 @@ int libcfs_kkuc_group_add(struct file *filp, int uid, int group,
 {
        struct kkuc_reg *reg;
 
-       if (group > KUC_GRP_MAX) {
+       if (!libcfs_kkuc_group_is_valid(group)) {
                CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
                return -EINVAL;
        }
@@ -139,8 +152,6 @@ int libcfs_kkuc_group_add(struct file *filp, int uid, int group,
        memcpy(reg->kr_data, data, data_len);
 
        down_write(&kg_sem);
-       if (kkuc_groups[group].next == NULL)
-               INIT_LIST_HEAD(&kkuc_groups[group]);
        list_add(&reg->kr_chain, &kkuc_groups[group]);
        up_write(&kg_sem);
 
@@ -155,8 +166,10 @@ int libcfs_kkuc_group_rem(int uid, int group)
        struct kkuc_reg *reg, *next;
        ENTRY;
 
-       if (kkuc_groups[group].next == NULL)
-               RETURN(0);
+       if (!libcfs_kkuc_group_is_valid(group)) {
+               CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
+               return -EINVAL;
+       }
 
        if (uid == 0) {
                /* Broadcast a shutdown message */
@@ -193,9 +206,14 @@ int libcfs_kkuc_group_put(int group, void *payload)
        int one_success = 0;
        ENTRY;
 
+       if (!libcfs_kkuc_group_is_valid(group)) {
+               CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
+               return -EINVAL;
+       }
+
        down_write(&kg_sem);
 
-       if (unlikely(kkuc_groups[group].next == NULL) ||
+       if (unlikely(list_empty(&kkuc_groups[group])) ||
            unlikely(OBD_FAIL_CHECK(OBD_FAIL_MDS_HSM_CT_REGISTER_NET))) {
                /* no agent have fully registered, CDT will retry */
                up_write(&kg_sem);
@@ -237,15 +255,11 @@ int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func,
        int              rc = 0;
        ENTRY;
 
-       if (group > KUC_GRP_MAX) {
+       if (!libcfs_kkuc_group_is_valid(group)) {
                CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
                RETURN(-EINVAL);
        }
 
-       /* no link for this group */
-       if (kkuc_groups[group].next == NULL)
-               RETURN(0);
-
        down_read(&kg_sem);
        list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
                if (reg->kr_fp != NULL)