forked from Minki/linux
edb39c9ded
This allows dynamic registering of cluster hooks. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
149 lines
3.3 KiB
C
149 lines
3.3 KiB
C
/*
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* Copyright (C) 2015, SUSE
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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*/
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#include <linux/module.h>
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#include <linux/dlm.h>
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#include <linux/sched.h>
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#include "md.h"
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#include "md-cluster.h"
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#define LVB_SIZE 64
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struct dlm_lock_resource {
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dlm_lockspace_t *ls;
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struct dlm_lksb lksb;
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char *name; /* lock name. */
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uint32_t flags; /* flags to pass to dlm_lock() */
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void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
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struct completion completion; /* completion for synchronized locking */
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};
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static void sync_ast(void *arg)
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{
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struct dlm_lock_resource *res;
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res = (struct dlm_lock_resource *) arg;
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complete(&res->completion);
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}
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static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
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{
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int ret = 0;
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init_completion(&res->completion);
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ret = dlm_lock(res->ls, mode, &res->lksb,
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res->flags, res->name, strlen(res->name),
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0, sync_ast, res, res->bast);
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if (ret)
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return ret;
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wait_for_completion(&res->completion);
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return res->lksb.sb_status;
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}
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static int dlm_unlock_sync(struct dlm_lock_resource *res)
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{
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return dlm_lock_sync(res, DLM_LOCK_NL);
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}
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static struct dlm_lock_resource *lockres_init(dlm_lockspace_t *lockspace,
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char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
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{
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struct dlm_lock_resource *res = NULL;
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int ret, namelen;
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res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
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if (!res)
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return NULL;
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res->ls = lockspace;
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namelen = strlen(name);
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res->name = kzalloc(namelen + 1, GFP_KERNEL);
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if (!res->name) {
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pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
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goto out_err;
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}
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strlcpy(res->name, name, namelen + 1);
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if (with_lvb) {
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res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
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if (!res->lksb.sb_lvbptr) {
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pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
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goto out_err;
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}
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res->flags = DLM_LKF_VALBLK;
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}
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if (bastfn)
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res->bast = bastfn;
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res->flags |= DLM_LKF_EXPEDITE;
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ret = dlm_lock_sync(res, DLM_LOCK_NL);
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if (ret) {
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pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
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goto out_err;
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}
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res->flags &= ~DLM_LKF_EXPEDITE;
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res->flags |= DLM_LKF_CONVERT;
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return res;
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out_err:
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kfree(res->lksb.sb_lvbptr);
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kfree(res->name);
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kfree(res);
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return NULL;
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}
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static void lockres_free(struct dlm_lock_resource *res)
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{
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if (!res)
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return;
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init_completion(&res->completion);
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dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res);
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wait_for_completion(&res->completion);
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kfree(res->name);
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kfree(res->lksb.sb_lvbptr);
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kfree(res);
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}
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static int join(struct mddev *mddev, int nodes)
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{
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return 0;
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}
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static int leave(struct mddev *mddev)
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{
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return 0;
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}
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static struct md_cluster_operations cluster_ops = {
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.join = join,
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.leave = leave,
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};
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static int __init cluster_init(void)
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{
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pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n");
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pr_info("Registering Cluster MD functions\n");
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register_md_cluster_operations(&cluster_ops, THIS_MODULE);
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return 0;
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}
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static void cluster_exit(void)
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{
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unregister_md_cluster_operations();
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}
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module_init(cluster_init);
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module_exit(cluster_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Clustering support for MD");
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