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() */ |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 25 | struct completion completion; /* completion for synchronized locking */ |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 26 | void (*bast)(void *arg, int mode); /* blocking AST function pointer*/ |
| 27 | struct mddev *mddev; /* pointing back to mddev. */ |
| 28 | }; |
| 29 | |
| 30 | struct md_cluster_info { |
| 31 | /* dlm lock space and resources for clustered raid. */ |
| 32 | dlm_lockspace_t *lockspace; |
| 33 | struct dlm_lock_resource *sb_lock; |
| 34 | struct mutex sb_mutex; |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 35 | }; |
| 36 | |
| 37 | static void sync_ast(void *arg) |
| 38 | { |
| 39 | struct dlm_lock_resource *res; |
| 40 | |
| 41 | res = (struct dlm_lock_resource *) arg; |
| 42 | complete(&res->completion); |
| 43 | } |
| 44 | |
| 45 | static int dlm_lock_sync(struct dlm_lock_resource *res, int mode) |
| 46 | { |
| 47 | int ret = 0; |
| 48 | |
| 49 | init_completion(&res->completion); |
| 50 | ret = dlm_lock(res->ls, mode, &res->lksb, |
| 51 | res->flags, res->name, strlen(res->name), |
| 52 | 0, sync_ast, res, res->bast); |
| 53 | if (ret) |
| 54 | return ret; |
| 55 | wait_for_completion(&res->completion); |
| 56 | return res->lksb.sb_status; |
| 57 | } |
| 58 | |
| 59 | static int dlm_unlock_sync(struct dlm_lock_resource *res) |
| 60 | { |
| 61 | return dlm_lock_sync(res, DLM_LOCK_NL); |
| 62 | } |
| 63 | |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 64 | static struct dlm_lock_resource *lockres_init(struct mddev *mddev, |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 65 | char *name, void (*bastfn)(void *arg, int mode), int with_lvb) |
| 66 | { |
| 67 | struct dlm_lock_resource *res = NULL; |
| 68 | int ret, namelen; |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 69 | struct md_cluster_info *cinfo = mddev->cluster_info; |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 70 | |
| 71 | res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL); |
| 72 | if (!res) |
| 73 | return NULL; |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 74 | res->ls = cinfo->lockspace; |
| 75 | res->mddev = mddev; |
Goldwyn Rodrigues | 47741b7 | 2014-03-07 13:49:26 -0600 | [diff] [blame] | 76 | namelen = strlen(name); |
| 77 | res->name = kzalloc(namelen + 1, GFP_KERNEL); |
| 78 | if (!res->name) { |
| 79 | pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name); |
| 80 | goto out_err; |
| 81 | } |
| 82 | strlcpy(res->name, name, namelen + 1); |
| 83 | if (with_lvb) { |
| 84 | res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL); |
| 85 | if (!res->lksb.sb_lvbptr) { |
| 86 | pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name); |
| 87 | goto out_err; |
| 88 | } |
| 89 | res->flags = DLM_LKF_VALBLK; |
| 90 | } |
| 91 | |
| 92 | if (bastfn) |
| 93 | res->bast = bastfn; |
| 94 | |
| 95 | res->flags |= DLM_LKF_EXPEDITE; |
| 96 | |
| 97 | ret = dlm_lock_sync(res, DLM_LOCK_NL); |
| 98 | if (ret) { |
| 99 | pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name); |
| 100 | goto out_err; |
| 101 | } |
| 102 | res->flags &= ~DLM_LKF_EXPEDITE; |
| 103 | res->flags |= DLM_LKF_CONVERT; |
| 104 | |
| 105 | return res; |
| 106 | out_err: |
| 107 | kfree(res->lksb.sb_lvbptr); |
| 108 | kfree(res->name); |
| 109 | kfree(res); |
| 110 | return NULL; |
| 111 | } |
| 112 | |
| 113 | static void lockres_free(struct dlm_lock_resource *res) |
| 114 | { |
| 115 | if (!res) |
| 116 | return; |
| 117 | |
| 118 | init_completion(&res->completion); |
| 119 | dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res); |
| 120 | wait_for_completion(&res->completion); |
| 121 | |
| 122 | kfree(res->name); |
| 123 | kfree(res->lksb.sb_lvbptr); |
| 124 | kfree(res); |
| 125 | } |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 126 | |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 127 | static char *pretty_uuid(char *dest, char *src) |
| 128 | { |
| 129 | int i, len = 0; |
| 130 | |
| 131 | for (i = 0; i < 16; i++) { |
| 132 | if (i == 4 || i == 6 || i == 8 || i == 10) |
| 133 | len += sprintf(dest + len, "-"); |
| 134 | len += sprintf(dest + len, "%02x", (__u8)src[i]); |
| 135 | } |
| 136 | return dest; |
| 137 | } |
| 138 | |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame] | 139 | static int join(struct mddev *mddev, int nodes) |
| 140 | { |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 141 | struct md_cluster_info *cinfo; |
| 142 | int ret; |
| 143 | char str[64]; |
| 144 | |
| 145 | if (!try_module_get(THIS_MODULE)) |
| 146 | return -ENOENT; |
| 147 | |
| 148 | cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL); |
| 149 | if (!cinfo) |
| 150 | return -ENOMEM; |
| 151 | |
| 152 | memset(str, 0, 64); |
| 153 | pretty_uuid(str, mddev->uuid); |
| 154 | ret = dlm_new_lockspace(str, NULL, DLM_LSFL_FS, LVB_SIZE, |
| 155 | NULL, NULL, NULL, &cinfo->lockspace); |
| 156 | if (ret) |
| 157 | goto err; |
| 158 | cinfo->sb_lock = lockres_init(mddev, "cmd-super", |
| 159 | NULL, 0); |
| 160 | if (!cinfo->sb_lock) { |
| 161 | ret = -ENOMEM; |
| 162 | goto err; |
| 163 | } |
| 164 | mutex_init(&cinfo->sb_mutex); |
| 165 | mddev->cluster_info = cinfo; |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame] | 166 | return 0; |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 167 | err: |
| 168 | if (cinfo->lockspace) |
| 169 | dlm_release_lockspace(cinfo->lockspace, 2); |
| 170 | kfree(cinfo); |
| 171 | module_put(THIS_MODULE); |
| 172 | return ret; |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame] | 173 | } |
| 174 | |
| 175 | static int leave(struct mddev *mddev) |
| 176 | { |
Goldwyn Rodrigues | c4ce867 | 2014-03-29 10:20:02 -0500 | [diff] [blame^] | 177 | struct md_cluster_info *cinfo = mddev->cluster_info; |
| 178 | |
| 179 | if (!cinfo) |
| 180 | return 0; |
| 181 | lockres_free(cinfo->sb_lock); |
| 182 | dlm_release_lockspace(cinfo->lockspace, 2); |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame] | 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | static struct md_cluster_operations cluster_ops = { |
| 187 | .join = join, |
| 188 | .leave = leave, |
| 189 | }; |
| 190 | |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 191 | static int __init cluster_init(void) |
| 192 | { |
| 193 | pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n"); |
| 194 | pr_info("Registering Cluster MD functions\n"); |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame] | 195 | register_md_cluster_operations(&cluster_ops, THIS_MODULE); |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | static void cluster_exit(void) |
| 200 | { |
Goldwyn Rodrigues | edb39c9 | 2014-03-29 10:01:53 -0500 | [diff] [blame] | 201 | unregister_md_cluster_operations(); |
Goldwyn Rodrigues | 8e854e9 | 2014-03-07 11:21:15 -0600 | [diff] [blame] | 202 | } |
| 203 | |
| 204 | module_init(cluster_init); |
| 205 | module_exit(cluster_exit); |
| 206 | MODULE_LICENSE("GPL"); |
| 207 | MODULE_DESCRIPTION("Clustering support for MD"); |