Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015, SUSE |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2, or (at your option) |
| 7 | * any later version. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | |
| 12 | #include <linux/module.h> |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 13 | #include <linux/dlm.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include "md.h" |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame^] | 16 | #include "md-cluster.h" |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 17 | |
| 18 | #define LVB_SIZE 64 |
| 19 | |
| 20 | struct dlm_lock_resource { |
| 21 | dlm_lockspace_t *ls; |
| 22 | struct dlm_lksb lksb; |
| 23 | char *name; /* lock name. */ |
| 24 | uint32_t flags; /* flags to pass to dlm_lock() */ |
| 25 | void (*bast)(void *arg, int mode); /* blocking AST function pointer*/ |
| 26 | struct completion completion; /* completion for synchronized locking */ |
| 27 | }; |
| 28 | |
| 29 | static void sync_ast(void *arg) |
| 30 | { |
| 31 | struct dlm_lock_resource *res; |
| 32 | |
| 33 | res = (struct dlm_lock_resource *) arg; |
| 34 | complete(&res->completion); |
| 35 | } |
| 36 | |
| 37 | static int dlm_lock_sync(struct dlm_lock_resource *res, int mode) |
| 38 | { |
| 39 | int ret = 0; |
| 40 | |
| 41 | init_completion(&res->completion); |
| 42 | ret = dlm_lock(res->ls, mode, &res->lksb, |
| 43 | res->flags, res->name, strlen(res->name), |
| 44 | 0, sync_ast, res, res->bast); |
| 45 | if (ret) |
| 46 | return ret; |
| 47 | wait_for_completion(&res->completion); |
| 48 | return res->lksb.sb_status; |
| 49 | } |
| 50 | |
| 51 | static int dlm_unlock_sync(struct dlm_lock_resource *res) |
| 52 | { |
| 53 | return dlm_lock_sync(res, DLM_LOCK_NL); |
| 54 | } |
| 55 | |
| 56 | static struct dlm_lock_resource *lockres_init(dlm_lockspace_t *lockspace, |
| 57 | char *name, void (*bastfn)(void *arg, int mode), int with_lvb) |
| 58 | { |
| 59 | struct dlm_lock_resource *res = NULL; |
| 60 | int ret, namelen; |
| 61 | |
| 62 | res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL); |
| 63 | if (!res) |
| 64 | return NULL; |
| 65 | res->ls = lockspace; |
| 66 | namelen = strlen(name); |
| 67 | res->name = kzalloc(namelen + 1, GFP_KERNEL); |
| 68 | if (!res->name) { |
| 69 | pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name); |
| 70 | goto out_err; |
| 71 | } |
| 72 | strlcpy(res->name, name, namelen + 1); |
| 73 | if (with_lvb) { |
| 74 | res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL); |
| 75 | if (!res->lksb.sb_lvbptr) { |
| 76 | pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name); |
| 77 | goto out_err; |
| 78 | } |
| 79 | res->flags = DLM_LKF_VALBLK; |
| 80 | } |
| 81 | |
| 82 | if (bastfn) |
| 83 | res->bast = bastfn; |
| 84 | |
| 85 | res->flags |= DLM_LKF_EXPEDITE; |
| 86 | |
| 87 | ret = dlm_lock_sync(res, DLM_LOCK_NL); |
| 88 | if (ret) { |
| 89 | pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name); |
| 90 | goto out_err; |
| 91 | } |
| 92 | res->flags &= ~DLM_LKF_EXPEDITE; |
| 93 | res->flags |= DLM_LKF_CONVERT; |
| 94 | |
| 95 | return res; |
| 96 | out_err: |
| 97 | kfree(res->lksb.sb_lvbptr); |
| 98 | kfree(res->name); |
| 99 | kfree(res); |
| 100 | return NULL; |
| 101 | } |
| 102 | |
| 103 | static void lockres_free(struct dlm_lock_resource *res) |
| 104 | { |
| 105 | if (!res) |
| 106 | return; |
| 107 | |
| 108 | init_completion(&res->completion); |
| 109 | dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res); |
| 110 | wait_for_completion(&res->completion); |
| 111 | |
| 112 | kfree(res->name); |
| 113 | kfree(res->lksb.sb_lvbptr); |
| 114 | kfree(res); |
| 115 | } |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 116 | |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame^] | 117 | static int join(struct mddev *mddev, int nodes) |
| 118 | { |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static int leave(struct mddev *mddev) |
| 123 | { |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | static struct md_cluster_operations cluster_ops = { |
| 128 | .join = join, |
| 129 | .leave = leave, |
| 130 | }; |
| 131 | |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 132 | static int __init cluster_init(void) |
| 133 | { |
| 134 | pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n"); |
| 135 | pr_info("Registering Cluster MD functions\n"); |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame^] | 136 | register_md_cluster_operations(&cluster_ops, THIS_MODULE); |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | static void cluster_exit(void) |
| 141 | { |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame^] | 142 | unregister_md_cluster_operations(); |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 143 | } |
| 144 | |
| 145 | module_init(cluster_init); |
| 146 | module_exit(cluster_exit); |
| 147 | MODULE_LICENSE("GPL"); |
| 148 | MODULE_DESCRIPTION("Clustering support for MD"); |