diff options
| -rw-r--r-- | drivers/md/md-cluster.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index f377e71..bc8ea9d 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) { |