1 /* 2 * This file is part of UBIFS. 3 * 4 * Copyright (C) 2006-2008 Nokia Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 51 17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 * Authors: Artem Bityutskiy (Битюцкий Артём) 20 * Adrian Hunter 21 */ 22 23 /* This file implements reading and writing the master node */ 24 25 #include "ubifs.h" 26 27 /** 28 * scan_for_master - search the valid master node. 29 * @c: UBIFS file-system description object 30 * 31 * This function scans the master node LEBs and search for the latest master 32 * node. Returns zero in case of success, %-EUCLEAN if there master area is 33 * corrupted and requires recovery, and a negative error code in case of 34 * failure. 35 */ 36 static int scan_for_master(struct ubifs_info *c) 37 { 38 struct ubifs_scan_leb *sleb; 39 struct ubifs_scan_node *snod; 40 int lnum, offs = 0, nodes_cnt; 41 42 lnum = UBIFS_MST_LNUM; 43 44 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); 45 if (IS_ERR(sleb)) 46 return PTR_ERR(sleb); 47 nodes_cnt = sleb->nodes_cnt; 48 if (nodes_cnt > 0) { 49 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, 50 list); 51 if (snod->type != UBIFS_MST_NODE) 52 goto out_dump; 53 memcpy(c->mst_node, snod->node, snod->len); 54 offs = snod->offs; 55 } 56 ubifs_scan_destroy(sleb); 57 58 lnum += 1; 59 60 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); 61 if (IS_ERR(sleb)) 62 return PTR_ERR(sleb); 63 if (sleb->nodes_cnt != nodes_cnt) 64 goto out; 65 if (!sleb->nodes_cnt) 66 goto out; 67 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); 68 if (snod->type != UBIFS_MST_NODE) 69 goto out_dump; 70 if (snod->offs != offs) 71 goto out; 72 if (memcmp((void *)c->mst_node + UBIFS_CH_SZ, 73 (void *)snod->node + UBIFS_CH_SZ, 74 UBIFS_MST_NODE_SZ - UBIFS_CH_SZ)) 75 goto out; 76 c->mst_offs = offs; 77 ubifs_scan_destroy(sleb); 78 return 0; 79 80 out: 81 ubifs_scan_destroy(sleb); 82 return -EUCLEAN; 83 84 out_dump: 85 ubifs_err("unexpected node type %d master LEB %d:%d", 86 snod->type, lnum, snod->offs); 87 ubifs_scan_destroy(sleb); 88 return -EINVAL; 89 } 90 91 /** 92 * validate_master - validate master node. 93 * @c: UBIFS file-system description object 94 * 95 * This function validates data which was read from master node. Returns zero 96 * if the data is all right and %-EINVAL if not. 97 */ 98 static int validate_master(const struct ubifs_info *c) 99 { 100 long long main_sz; 101 int err; 102 103 if (c->max_sqnum >= SQNUM_WATERMARK) { 104 err = 1; 105 goto out; 106 } 107 108 if (c->cmt_no >= c->max_sqnum) { 109 err = 2; 110 goto out; 111 } 112 113 if (c->highest_inum >= INUM_WATERMARK) { 114 err = 3; 115 goto out; 116 } 117 118 if (c->lhead_lnum < UBIFS_LOG_LNUM || 119 c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs || 120 c->lhead_offs < 0 || c->lhead_offs >= c->leb_size || 121 c->lhead_offs & (c->min_io_size - 1)) { 122 err = 4; 123 goto out; 124 } 125 126 if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first || 127 c->zroot.offs >= c->leb_size || c->zroot.offs & 7) { 128 err = 5; 129 goto out; 130 } 131 132 if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len || 133 c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) { 134 err = 6; 135 goto out; 136 } 137 138 if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) { 139 err = 7; 140 goto out; 141 } 142 143 if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first || 144 c->ihead_offs % c->min_io_size || c->ihead_offs < 0 || 145 c->ihead_offs > c->leb_size || c->ihead_offs & 7) { 146 err = 8; 147 goto out; 148 } 149 150 main_sz = (long long)c->main_lebs * c->leb_size; 151 if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) { 152 err = 9; 153 goto out; 154 } 155 156 if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last || 157 c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) { 158 err = 10; 159 goto out; 160 } 161 162 if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last || 163 c->nhead_offs < 0 || c->nhead_offs % c->min_io_size || 164 c->nhead_offs > c->leb_size) { 165 err = 11; 166 goto out; 167 } 168 169 if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last || 170 c->ltab_offs < 0 || 171 c->ltab_offs + c->ltab_sz > c->leb_size) { 172 err = 12; 173 goto out; 174 } 175 176 if (c->big_lpt && (c->lsave_lnum < c->lpt_first || 177 c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 || 178 c->lsave_offs + c->lsave_sz > c->leb_size)) { 179 err = 13; 180 goto out; 181 } 182 183 if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) { 184 err = 14; 185 goto out; 186 } 187 188 if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) { 189 err = 15; 190 goto out; 191 } 192 193 if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) { 194 err = 16; 195 goto out; 196 } 197 198 if (c->lst.total_free < 0 || c->lst.total_free > main_sz || 199 c->lst.total_free & 7) { 200 err = 17; 201 goto out; 202 } 203 204 if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) { 205 err = 18; 206 goto out; 207 } 208 209 if (c->lst.total_used < 0 || (c->lst.total_used & 7)) { 210 err = 19; 211 goto out; 212 } 213 214 if (c->lst.total_free + c->lst.total_dirty + 215 c->lst.total_used > main_sz) { 216 err = 20; 217 goto out; 218 } 219 220 if (c->lst.total_dead + c->lst.total_dark + 221 c->lst.total_used + c->bi.old_idx_sz > main_sz) { 222 err = 21; 223 goto out; 224 } 225 226 if (c->lst.total_dead < 0 || 227 c->lst.total_dead > c->lst.total_free + c->lst.total_dirty || 228 c->lst.total_dead & 7) { 229 err = 22; 230 goto out; 231 } 232 233 if (c->lst.total_dark < 0 || 234 c->lst.total_dark > c->lst.total_free + c->lst.total_dirty || 235 c->lst.total_dark & 7) { 236 err = 23; 237 goto out; 238 } 239 240 return 0; 241 242 out: 243 ubifs_err("bad master node at offset %d error %d", c->mst_offs, err); 244 ubifs_dump_node(c, c->mst_node); 245 return -EINVAL; 246 } 247 248 /** 249 * ubifs_read_master - read master node. 250 * @c: UBIFS file-system description object 251 * 252 * This function finds and reads the master node during file-system mount. If 253 * the flash is empty, it creates default master node as well. Returns zero in 254 * case of success and a negative error code in case of failure. 255 */ 256 int ubifs_read_master(struct ubifs_info *c) 257 { 258 int err, old_leb_cnt; 259 260 c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL); 261 if (!c->mst_node) 262 return -ENOMEM; 263 264 err = scan_for_master(c); 265 if (err) { 266 if (err == -EUCLEAN) 267 err = ubifs_recover_master_node(c); 268 if (err) 269 /* 270 * Note, we do not free 'c->mst_node' here because the 271 * unmount routine will take care of this. 272 */ 273 return err; 274 } 275 276 /* Make sure that the recovery flag is clear */ 277 c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY); 278 279 c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum); 280 c->highest_inum = le64_to_cpu(c->mst_node->highest_inum); 281 c->cmt_no = le64_to_cpu(c->mst_node->cmt_no); 282 c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum); 283 c->zroot.offs = le32_to_cpu(c->mst_node->root_offs); 284 c->zroot.len = le32_to_cpu(c->mst_node->root_len); 285 c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum); 286 c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum); 287 c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum); 288 c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs); 289 c->bi.old_idx_sz = le64_to_cpu(c->mst_node->index_size); 290 c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum); 291 c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs); 292 c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum); 293 c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs); 294 c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum); 295 c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs); 296 c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum); 297 c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs); 298 c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum); 299 c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs); 300 c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs); 301 old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt); 302 c->lst.total_free = le64_to_cpu(c->mst_node->total_free); 303 c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty); 304 c->lst.total_used = le64_to_cpu(c->mst_node->total_used); 305 c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead); 306 c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark); 307 308 c->calc_idx_sz = c->bi.old_idx_sz; 309 310 if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS)) 311 c->no_orphs = 1; 312 313 if (old_leb_cnt != c->leb_cnt) { 314 /* The file system has been resized */ 315 int growth = c->leb_cnt - old_leb_cnt; 316 317 if (c->leb_cnt < old_leb_cnt || 318 c->leb_cnt < UBIFS_MIN_LEB_CNT) { 319 ubifs_err("bad leb_cnt on master node"); 320 ubifs_dump_node(c, c->mst_node); 321 return -EINVAL; 322 } 323 324 dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs", 325 old_leb_cnt, c->leb_cnt); 326 c->lst.empty_lebs += growth; 327 c->lst.total_free += growth * (long long)c->leb_size; 328 c->lst.total_dark += growth * (long long)c->dark_wm; 329 330 /* 331 * Reflect changes back onto the master node. N.B. the master 332 * node gets written immediately whenever mounting (or 333 * remounting) in read-write mode, so we do not need to write it 334 * here. 335 */ 336 c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt); 337 c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs); 338 c->mst_node->total_free = cpu_to_le64(c->lst.total_free); 339 c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark); 340 } 341 342 err = validate_master(c); 343 if (err) 344 return err; 345 346 err = dbg_old_index_check_init(c, &c->zroot); 347 348 return err; 349 } 350 351 /** 352 * ubifs_write_master - write master node. 353 * @c: UBIFS file-system description object 354 * 355 * This function writes the master node. The caller has to take the 356 * @c->mst_mutex lock before calling this function. Returns zero in case of 357 * success and a negative error code in case of failure. The master node is 358 * written twice to enable recovery. 359 */ 360 int ubifs_write_master(struct ubifs_info *c) 361 { 362 int err, lnum, offs, len; 363 364 ubifs_assert(!c->ro_media && !c->ro_mount); 365 if (c->ro_error) 366 return -EROFS; 367 368 lnum = UBIFS_MST_LNUM; 369 offs = c->mst_offs + c->mst_node_alsz; 370 len = UBIFS_MST_NODE_SZ; 371 372 if (offs + UBIFS_MST_NODE_SZ > c->leb_size) { 373 err = ubifs_leb_unmap(c, lnum); 374 if (err) 375 return err; 376 offs = 0; 377 } 378 379 c->mst_offs = offs; 380 c->mst_node->highest_inum = cpu_to_le64(c->highest_inum); 381 382 err = ubifs_write_node(c, c->mst_node, len, lnum, offs); 383 if (err) 384 return err; 385 386 lnum += 1; 387 388 if (offs == 0) { 389 err = ubifs_leb_unmap(c, lnum); 390 if (err) 391 return err; 392 } 393 err = ubifs_write_node(c, c->mst_node, len, lnum, offs); 394 395 return err; 396 } 397