1 files changed, 102 insertions, 0 deletions

diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index f377e71949c5..bc8ea9d76875 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -10,6 +10,108 @@
 
 
 #include <linux/module.h>
+#include <linux/dlm.h>
+#include <linux/sched.h>
+#include "md.h"
+
+#define LVB_SIZE        64
+
+struct dlm_lock_resource {
+        dlm_lockspace_t *ls;
+        struct dlm_lksb lksb;
+        char *name; /* lock name. */
+        uint32_t flags; /* flags to pass to dlm_lock() */
+        void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
+        struct completion completion; /* completion for synchronized locking */
+};
+
+static void sync_ast(void *arg)
+{
+        struct dlm_lock_resource *res;
+
+        res = (struct dlm_lock_resource *) arg;
+        complete(&res->completion);
+}
+
+static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
+{
+        int ret = 0;
+
+        init_completion(&res->completion);
+        ret = dlm_lock(res->ls, mode, &res->lksb,
+                        res->flags, res->name, strlen(res->name),
+                        0, sync_ast, res, res->bast);
+        if (ret)
+                return ret;
+        wait_for_completion(&res->completion);
+        return res->lksb.sb_status;
+}
+
+static int dlm_unlock_sync(struct dlm_lock_resource *res)
+{
+        return dlm_lock_sync(res, DLM_LOCK_NL);
+}
+
+static struct dlm_lock_resource *lockres_init(dlm_lockspace_t *lockspace,
+                char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
+{
+        struct dlm_lock_resource *res = NULL;
+        int ret, namelen;
+
+        res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
+        if (!res)
+                return NULL;
+        res->ls = lockspace;
+        namelen = strlen(name);
+        res->name = kzalloc(namelen + 1, GFP_KERNEL);
+        if (!res->name) {
+                pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
+                goto out_err;
+        }
+        strlcpy(res->name, name, namelen + 1);
+        if (with_lvb) {
+                res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
+                if (!res->lksb.sb_lvbptr) {
+                        pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
+                        goto out_err;
+                }
+                res->flags = DLM_LKF_VALBLK;
+        }
+
+        if (bastfn)
+                res->bast = bastfn;
+
+        res->flags |= DLM_LKF_EXPEDITE;
+
+        ret = dlm_lock_sync(res, DLM_LOCK_NL);
+        if (ret) {
+                pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
+                goto out_err;
+        }
+        res->flags &= ~DLM_LKF_EXPEDITE;
+        res->flags |= DLM_LKF_CONVERT;
+
+        return res;
+out_err:
+        kfree(res->lksb.sb_lvbptr);
+        kfree(res->name);
+        kfree(res);
+        return NULL;
+}
+
+static void lockres_free(struct dlm_lock_resource *res)
+{
+        if (!res)
+                return;
+
+        init_completion(&res->completion);
+        dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res);
+        wait_for_completion(&res->completion);
+
+        kfree(res->name);
+        kfree(res->lksb.sb_lvbptr);
+        kfree(res);
+}
 
 static int __init cluster_init(void)
 {