1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * slot_map.c 5 * 6 * 7 * 8 * Copyright (C) 2002, 2004 Oracle. All rights reserved. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public 12 * License as published by the Free Software Foundation; either 13 * version 2 of the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public 21 * License along with this program; if not, write to the 22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 23 * Boston, MA 021110-1307, USA. 24 */ 25 26 #include <linux/types.h> 27 #include <linux/slab.h> 28 #include <linux/highmem.h> 29 #include <linux/smp_lock.h> 30 31 #define MLOG_MASK_PREFIX ML_SUPER 32 #include <cluster/masklog.h> 33 34 #include "ocfs2.h" 35 36 #include "dlmglue.h" 37 #include "extent_map.h" 38 #include "heartbeat.h" 39 #include "inode.h" 40 #include "slot_map.h" 41 #include "super.h" 42 #include "sysfile.h" 43 44 #include "buffer_head_io.h" 45 46 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si, 47 s16 global); 48 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si, 49 s16 slot_num, 50 s16 node_num); 51 52 /* Use the slot information we've collected to create a map of mounted 53 * nodes. Should be holding an EX on super block. assumes slot info is 54 * up to date. Note that we call this *after* we find a slot, so our 55 * own node should be set in the map too... */ 56 void ocfs2_populate_mounted_map(struct ocfs2_super *osb) 57 { 58 int i; 59 struct ocfs2_slot_info *si = osb->slot_info; 60 61 spin_lock(&si->si_lock); 62 63 for (i = 0; i < si->si_size; i++) 64 if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT) 65 ocfs2_node_map_set_bit(osb, &osb->mounted_map, 66 si->si_global_node_nums[i]); 67 68 spin_unlock(&si->si_lock); 69 } 70 71 /* post the slot information on disk into our slot_info struct. */ 72 void ocfs2_update_slot_info(struct ocfs2_slot_info *si) 73 { 74 int i; 75 __le16 *disk_info; 76 77 /* we don't read the slot block here as ocfs2_super_lock 78 * should've made sure we have the most recent copy. */ 79 spin_lock(&si->si_lock); 80 disk_info = (__le16 *) si->si_bh->b_data; 81 82 for (i = 0; i < si->si_size; i++) 83 si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]); 84 85 spin_unlock(&si->si_lock); 86 } 87 88 /* post the our slot info stuff into it's destination bh and write it 89 * out. */ 90 int ocfs2_update_disk_slots(struct ocfs2_super *osb, 91 struct ocfs2_slot_info *si) 92 { 93 int status, i; 94 __le16 *disk_info = (__le16 *) si->si_bh->b_data; 95 96 spin_lock(&si->si_lock); 97 for (i = 0; i < si->si_size; i++) 98 disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]); 99 spin_unlock(&si->si_lock); 100 101 status = ocfs2_write_block(osb, si->si_bh, si->si_inode); 102 if (status < 0) 103 mlog_errno(status); 104 105 return status; 106 } 107 108 /* try to find global node in the slot info. Returns 109 * OCFS2_INVALID_SLOT if nothing is found. */ 110 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si, 111 s16 global) 112 { 113 int i; 114 s16 ret = OCFS2_INVALID_SLOT; 115 116 for(i = 0; i < si->si_num_slots; i++) { 117 if (global == si->si_global_node_nums[i]) { 118 ret = (s16) i; 119 break; 120 } 121 } 122 return ret; 123 } 124 125 static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si) 126 { 127 int i; 128 s16 ret = OCFS2_INVALID_SLOT; 129 130 for(i = 0; i < si->si_num_slots; i++) { 131 if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) { 132 ret = (s16) i; 133 break; 134 } 135 } 136 return ret; 137 } 138 139 s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si, 140 s16 global) 141 { 142 s16 ret; 143 144 spin_lock(&si->si_lock); 145 ret = __ocfs2_node_num_to_slot(si, global); 146 spin_unlock(&si->si_lock); 147 return ret; 148 } 149 150 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si, 151 s16 slot_num, 152 s16 node_num) 153 { 154 BUG_ON(slot_num == OCFS2_INVALID_SLOT); 155 BUG_ON(slot_num >= si->si_num_slots); 156 BUG_ON((node_num != O2NM_INVALID_NODE_NUM) && 157 (node_num >= O2NM_MAX_NODES)); 158 159 si->si_global_node_nums[slot_num] = node_num; 160 } 161 162 void ocfs2_clear_slot(struct ocfs2_slot_info *si, 163 s16 slot_num) 164 { 165 spin_lock(&si->si_lock); 166 __ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT); 167 spin_unlock(&si->si_lock); 168 } 169 170 int ocfs2_init_slot_info(struct ocfs2_super *osb) 171 { 172 int status, i; 173 u64 blkno; 174 struct inode *inode = NULL; 175 struct buffer_head *bh = NULL; 176 struct ocfs2_slot_info *si; 177 178 si = kcalloc(1, sizeof(struct ocfs2_slot_info), GFP_KERNEL); 179 if (!si) { 180 status = -ENOMEM; 181 mlog_errno(status); 182 goto bail; 183 } 184 185 spin_lock_init(&si->si_lock); 186 si->si_num_slots = osb->max_slots; 187 si->si_size = OCFS2_MAX_SLOTS; 188 189 for(i = 0; i < si->si_num_slots; i++) 190 si->si_global_node_nums[i] = OCFS2_INVALID_SLOT; 191 192 inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE, 193 OCFS2_INVALID_SLOT); 194 if (!inode) { 195 status = -EINVAL; 196 mlog_errno(status); 197 goto bail; 198 } 199 200 status = ocfs2_extent_map_get_blocks(inode, 0ULL, 1, &blkno, NULL); 201 if (status < 0) { 202 mlog_errno(status); 203 goto bail; 204 } 205 206 status = ocfs2_read_block(osb, blkno, &bh, 0, inode); 207 if (status < 0) { 208 mlog_errno(status); 209 goto bail; 210 } 211 212 si->si_inode = inode; 213 si->si_bh = bh; 214 osb->slot_info = si; 215 bail: 216 if (status < 0 && si) 217 ocfs2_free_slot_info(si); 218 219 return status; 220 } 221 222 void ocfs2_free_slot_info(struct ocfs2_slot_info *si) 223 { 224 if (si->si_inode) 225 iput(si->si_inode); 226 if (si->si_bh) 227 brelse(si->si_bh); 228 kfree(si); 229 } 230 231 int ocfs2_find_slot(struct ocfs2_super *osb) 232 { 233 int status; 234 s16 slot; 235 struct ocfs2_slot_info *si; 236 237 mlog_entry_void(); 238 239 si = osb->slot_info; 240 241 ocfs2_update_slot_info(si); 242 243 spin_lock(&si->si_lock); 244 /* search for ourselves first and take the slot if it already 245 * exists. Perhaps we need to mark this in a variable for our 246 * own journal recovery? Possibly not, though we certainly 247 * need to warn to the user */ 248 slot = __ocfs2_node_num_to_slot(si, osb->node_num); 249 if (slot == OCFS2_INVALID_SLOT) { 250 /* if no slot yet, then just take 1st available 251 * one. */ 252 slot = __ocfs2_find_empty_slot(si); 253 if (slot == OCFS2_INVALID_SLOT) { 254 spin_unlock(&si->si_lock); 255 mlog(ML_ERROR, "no free slots available!\n"); 256 status = -EINVAL; 257 goto bail; 258 } 259 } else 260 mlog(ML_NOTICE, "slot %d is already allocated to this node!\n", 261 slot); 262 263 __ocfs2_fill_slot(si, slot, osb->node_num); 264 osb->slot_num = slot; 265 spin_unlock(&si->si_lock); 266 267 mlog(0, "taking node slot %d\n", osb->slot_num); 268 269 status = ocfs2_update_disk_slots(osb, si); 270 if (status < 0) 271 mlog_errno(status); 272 273 bail: 274 mlog_exit(status); 275 return status; 276 } 277 278 void ocfs2_put_slot(struct ocfs2_super *osb) 279 { 280 int status; 281 struct ocfs2_slot_info *si = osb->slot_info; 282 283 if (!si) 284 return; 285 286 ocfs2_update_slot_info(si); 287 288 spin_lock(&si->si_lock); 289 __ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT); 290 osb->slot_num = OCFS2_INVALID_SLOT; 291 spin_unlock(&si->si_lock); 292 293 status = ocfs2_update_disk_slots(osb, si); 294 if (status < 0) { 295 mlog_errno(status); 296 goto bail; 297 } 298 299 bail: 300 osb->slot_info = NULL; 301 ocfs2_free_slot_info(si); 302 } 303 304