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 30 #define MLOG_MASK_PREFIX ML_SUPER 31 #include <cluster/masklog.h> 32 33 #include "ocfs2.h" 34 35 #include "dlmglue.h" 36 #include "extent_map.h" 37 #include "heartbeat.h" 38 #include "inode.h" 39 #include "slot_map.h" 40 #include "super.h" 41 #include "sysfile.h" 42 43 #include "buffer_head_io.h" 44 45 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si, 46 s16 global); 47 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si, 48 s16 slot_num, 49 s16 node_num); 50 51 /* Use the slot information we've collected to create a map of mounted 52 * nodes. Should be holding an EX on super block. assumes slot info is 53 * up to date. Note that we call this *after* we find a slot, so our 54 * own node should be set in the map too... */ 55 void ocfs2_populate_mounted_map(struct ocfs2_super *osb) 56 { 57 int i; 58 struct ocfs2_slot_info *si = osb->slot_info; 59 60 spin_lock(&si->si_lock); 61 62 for (i = 0; i < si->si_size; i++) 63 if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT) 64 ocfs2_node_map_set_bit(osb, &osb->mounted_map, 65 si->si_global_node_nums[i]); 66 67 spin_unlock(&si->si_lock); 68 } 69 70 /* post the slot information on disk into our slot_info struct. */ 71 void ocfs2_update_slot_info(struct ocfs2_slot_info *si) 72 { 73 int i; 74 __le16 *disk_info; 75 76 /* we don't read the slot block here as ocfs2_super_lock 77 * should've made sure we have the most recent copy. */ 78 spin_lock(&si->si_lock); 79 disk_info = (__le16 *) si->si_bh->b_data; 80 81 for (i = 0; i < si->si_size; i++) 82 si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]); 83 84 spin_unlock(&si->si_lock); 85 } 86 87 /* post the our slot info stuff into it's destination bh and write it 88 * out. */ 89 int ocfs2_update_disk_slots(struct ocfs2_super *osb, 90 struct ocfs2_slot_info *si) 91 { 92 int status, i; 93 __le16 *disk_info = (__le16 *) si->si_bh->b_data; 94 95 spin_lock(&si->si_lock); 96 for (i = 0; i < si->si_size; i++) 97 disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]); 98 spin_unlock(&si->si_lock); 99 100 status = ocfs2_write_block(osb, si->si_bh, si->si_inode); 101 if (status < 0) 102 mlog_errno(status); 103 104 return status; 105 } 106 107 /* try to find global node in the slot info. Returns 108 * OCFS2_INVALID_SLOT if nothing is found. */ 109 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si, 110 s16 global) 111 { 112 int i; 113 s16 ret = OCFS2_INVALID_SLOT; 114 115 for(i = 0; i < si->si_num_slots; i++) { 116 if (global == si->si_global_node_nums[i]) { 117 ret = (s16) i; 118 break; 119 } 120 } 121 return ret; 122 } 123 124 static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si, s16 preferred) 125 { 126 int i; 127 s16 ret = OCFS2_INVALID_SLOT; 128 129 if (preferred >= 0 && preferred < si->si_num_slots) { 130 if (OCFS2_INVALID_SLOT == si->si_global_node_nums[preferred]) { 131 ret = preferred; 132 goto out; 133 } 134 } 135 136 for(i = 0; i < si->si_num_slots; i++) { 137 if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) { 138 ret = (s16) i; 139 break; 140 } 141 } 142 out: 143 return ret; 144 } 145 146 s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si, 147 s16 global) 148 { 149 s16 ret; 150 151 spin_lock(&si->si_lock); 152 ret = __ocfs2_node_num_to_slot(si, global); 153 spin_unlock(&si->si_lock); 154 return ret; 155 } 156 157 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si, 158 s16 slot_num, 159 s16 node_num) 160 { 161 BUG_ON(slot_num == OCFS2_INVALID_SLOT); 162 BUG_ON(slot_num >= si->si_num_slots); 163 BUG_ON((node_num != O2NM_INVALID_NODE_NUM) && 164 (node_num >= O2NM_MAX_NODES)); 165 166 si->si_global_node_nums[slot_num] = node_num; 167 } 168 169 void ocfs2_clear_slot(struct ocfs2_slot_info *si, 170 s16 slot_num) 171 { 172 spin_lock(&si->si_lock); 173 __ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT); 174 spin_unlock(&si->si_lock); 175 } 176 177 int ocfs2_init_slot_info(struct ocfs2_super *osb) 178 { 179 int status, i; 180 u64 blkno; 181 struct inode *inode = NULL; 182 struct buffer_head *bh = NULL; 183 struct ocfs2_slot_info *si; 184 185 si = kzalloc(sizeof(struct ocfs2_slot_info), GFP_KERNEL); 186 if (!si) { 187 status = -ENOMEM; 188 mlog_errno(status); 189 goto bail; 190 } 191 192 spin_lock_init(&si->si_lock); 193 si->si_num_slots = osb->max_slots; 194 si->si_size = OCFS2_MAX_SLOTS; 195 196 for(i = 0; i < si->si_num_slots; i++) 197 si->si_global_node_nums[i] = OCFS2_INVALID_SLOT; 198 199 inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE, 200 OCFS2_INVALID_SLOT); 201 if (!inode) { 202 status = -EINVAL; 203 mlog_errno(status); 204 goto bail; 205 } 206 207 status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL, NULL); 208 if (status < 0) { 209 mlog_errno(status); 210 goto bail; 211 } 212 213 status = ocfs2_read_block(osb, blkno, &bh, 0, inode); 214 if (status < 0) { 215 mlog_errno(status); 216 goto bail; 217 } 218 219 si->si_inode = inode; 220 si->si_bh = bh; 221 osb->slot_info = si; 222 bail: 223 if (status < 0 && si) 224 ocfs2_free_slot_info(si); 225 226 return status; 227 } 228 229 void ocfs2_free_slot_info(struct ocfs2_slot_info *si) 230 { 231 if (si->si_inode) 232 iput(si->si_inode); 233 if (si->si_bh) 234 brelse(si->si_bh); 235 kfree(si); 236 } 237 238 int ocfs2_find_slot(struct ocfs2_super *osb) 239 { 240 int status; 241 s16 slot; 242 struct ocfs2_slot_info *si; 243 244 mlog_entry_void(); 245 246 si = osb->slot_info; 247 248 ocfs2_update_slot_info(si); 249 250 spin_lock(&si->si_lock); 251 /* search for ourselves first and take the slot if it already 252 * exists. Perhaps we need to mark this in a variable for our 253 * own journal recovery? Possibly not, though we certainly 254 * need to warn to the user */ 255 slot = __ocfs2_node_num_to_slot(si, osb->node_num); 256 if (slot == OCFS2_INVALID_SLOT) { 257 /* if no slot yet, then just take 1st available 258 * one. */ 259 slot = __ocfs2_find_empty_slot(si, osb->preferred_slot); 260 if (slot == OCFS2_INVALID_SLOT) { 261 spin_unlock(&si->si_lock); 262 mlog(ML_ERROR, "no free slots available!\n"); 263 status = -EINVAL; 264 goto bail; 265 } 266 } else 267 mlog(ML_NOTICE, "slot %d is already allocated to this node!\n", 268 slot); 269 270 __ocfs2_fill_slot(si, slot, osb->node_num); 271 osb->slot_num = slot; 272 spin_unlock(&si->si_lock); 273 274 mlog(0, "taking node slot %d\n", osb->slot_num); 275 276 status = ocfs2_update_disk_slots(osb, si); 277 if (status < 0) 278 mlog_errno(status); 279 280 bail: 281 mlog_exit(status); 282 return status; 283 } 284 285 void ocfs2_put_slot(struct ocfs2_super *osb) 286 { 287 int status; 288 struct ocfs2_slot_info *si = osb->slot_info; 289 290 if (!si) 291 return; 292 293 ocfs2_update_slot_info(si); 294 295 spin_lock(&si->si_lock); 296 __ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT); 297 osb->slot_num = OCFS2_INVALID_SLOT; 298 spin_unlock(&si->si_lock); 299 300 status = ocfs2_update_disk_slots(osb, si); 301 if (status < 0) { 302 mlog_errno(status); 303 goto bail; 304 } 305 306 bail: 307 osb->slot_info = NULL; 308 ocfs2_free_slot_info(si); 309 } 310 311