1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * This file is part of UBIFS. 4 * 5 * Copyright (C) 2006-2008 Nokia Corporation. 6 * 7 * Authors: Artem Bityutskiy (Битюцкий Артём) 8 * Adrian Hunter 9 */ 10 11 /* This file implements reading and writing the master node */ 12 13 #include "ubifs.h" 14 #ifdef __UBOOT__ 15 #include <linux/compat.h> 16 #include <linux/err.h> 17 #include <ubi_uboot.h> 18 #endif 19 20 /** 21 * scan_for_master - search the valid master node. 22 * @c: UBIFS file-system description object 23 * 24 * This function scans the master node LEBs and search for the latest master 25 * node. Returns zero in case of success, %-EUCLEAN if there master area is 26 * corrupted and requires recovery, and a negative error code in case of 27 * failure. 28 */ 29 static int scan_for_master(struct ubifs_info *c) 30 { 31 struct ubifs_scan_leb *sleb; 32 struct ubifs_scan_node *snod; 33 int lnum, offs = 0, nodes_cnt; 34 35 lnum = UBIFS_MST_LNUM; 36 37 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); 38 if (IS_ERR(sleb)) 39 return PTR_ERR(sleb); 40 nodes_cnt = sleb->nodes_cnt; 41 if (nodes_cnt > 0) { 42 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, 43 list); 44 if (snod->type != UBIFS_MST_NODE) 45 goto out_dump; 46 memcpy(c->mst_node, snod->node, snod->len); 47 offs = snod->offs; 48 } 49 ubifs_scan_destroy(sleb); 50 51 lnum += 1; 52 53 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); 54 if (IS_ERR(sleb)) 55 return PTR_ERR(sleb); 56 if (sleb->nodes_cnt != nodes_cnt) 57 goto out; 58 if (!sleb->nodes_cnt) 59 goto out; 60 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); 61 if (snod->type != UBIFS_MST_NODE) 62 goto out_dump; 63 if (snod->offs != offs) 64 goto out; 65 if (memcmp((void *)c->mst_node + UBIFS_CH_SZ, 66 (void *)snod->node + UBIFS_CH_SZ, 67 UBIFS_MST_NODE_SZ - UBIFS_CH_SZ)) 68 goto out; 69 c->mst_offs = offs; 70 ubifs_scan_destroy(sleb); 71 return 0; 72 73 out: 74 ubifs_scan_destroy(sleb); 75 return -EUCLEAN; 76 77 out_dump: 78 ubifs_err(c, "unexpected node type %d master LEB %d:%d", 79 snod->type, lnum, snod->offs); 80 ubifs_scan_destroy(sleb); 81 return -EINVAL; 82 } 83 84 /** 85 * validate_master - validate master node. 86 * @c: UBIFS file-system description object 87 * 88 * This function validates data which was read from master node. Returns zero 89 * if the data is all right and %-EINVAL if not. 90 */ 91 static int validate_master(const struct ubifs_info *c) 92 { 93 long long main_sz; 94 int err; 95 96 if (c->max_sqnum >= SQNUM_WATERMARK) { 97 err = 1; 98 goto out; 99 } 100 101 if (c->cmt_no >= c->max_sqnum) { 102 err = 2; 103 goto out; 104 } 105 106 if (c->highest_inum >= INUM_WATERMARK) { 107 err = 3; 108 goto out; 109 } 110 111 if (c->lhead_lnum < UBIFS_LOG_LNUM || 112 c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs || 113 c->lhead_offs < 0 || c->lhead_offs >= c->leb_size || 114 c->lhead_offs & (c->min_io_size - 1)) { 115 err = 4; 116 goto out; 117 } 118 119 if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first || 120 c->zroot.offs >= c->leb_size || c->zroot.offs & 7) { 121 err = 5; 122 goto out; 123 } 124 125 if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len || 126 c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) { 127 err = 6; 128 goto out; 129 } 130 131 if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) { 132 err = 7; 133 goto out; 134 } 135 136 if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first || 137 c->ihead_offs % c->min_io_size || c->ihead_offs < 0 || 138 c->ihead_offs > c->leb_size || c->ihead_offs & 7) { 139 err = 8; 140 goto out; 141 } 142 143 main_sz = (long long)c->main_lebs * c->leb_size; 144 if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) { 145 err = 9; 146 goto out; 147 } 148 149 if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last || 150 c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) { 151 err = 10; 152 goto out; 153 } 154 155 if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last || 156 c->nhead_offs < 0 || c->nhead_offs % c->min_io_size || 157 c->nhead_offs > c->leb_size) { 158 err = 11; 159 goto out; 160 } 161 162 if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last || 163 c->ltab_offs < 0 || 164 c->ltab_offs + c->ltab_sz > c->leb_size) { 165 err = 12; 166 goto out; 167 } 168 169 if (c->big_lpt && (c->lsave_lnum < c->lpt_first || 170 c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 || 171 c->lsave_offs + c->lsave_sz > c->leb_size)) { 172 err = 13; 173 goto out; 174 } 175 176 if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) { 177 err = 14; 178 goto out; 179 } 180 181 if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) { 182 err = 15; 183 goto out; 184 } 185 186 if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) { 187 err = 16; 188 goto out; 189 } 190 191 if (c->lst.total_free < 0 || c->lst.total_free > main_sz || 192 c->lst.total_free & 7) { 193 err = 17; 194 goto out; 195 } 196 197 if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) { 198 err = 18; 199 goto out; 200 } 201 202 if (c->lst.total_used < 0 || (c->lst.total_used & 7)) { 203 err = 19; 204 goto out; 205 } 206 207 if (c->lst.total_free + c->lst.total_dirty + 208 c->lst.total_used > main_sz) { 209 err = 20; 210 goto out; 211 } 212 213 if (c->lst.total_dead + c->lst.total_dark + 214 c->lst.total_used + c->bi.old_idx_sz > main_sz) { 215 err = 21; 216 goto out; 217 } 218 219 if (c->lst.total_dead < 0 || 220 c->lst.total_dead > c->lst.total_free + c->lst.total_dirty || 221 c->lst.total_dead & 7) { 222 err = 22; 223 goto out; 224 } 225 226 if (c->lst.total_dark < 0 || 227 c->lst.total_dark > c->lst.total_free + c->lst.total_dirty || 228 c->lst.total_dark & 7) { 229 err = 23; 230 goto out; 231 } 232 233 return 0; 234 235 out: 236 ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err); 237 ubifs_dump_node(c, c->mst_node); 238 return -EINVAL; 239 } 240 241 /** 242 * ubifs_read_master - read master node. 243 * @c: UBIFS file-system description object 244 * 245 * This function finds and reads the master node during file-system mount. If 246 * the flash is empty, it creates default master node as well. Returns zero in 247 * case of success and a negative error code in case of failure. 248 */ 249 int ubifs_read_master(struct ubifs_info *c) 250 { 251 int err, old_leb_cnt; 252 253 c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL); 254 if (!c->mst_node) 255 return -ENOMEM; 256 257 err = scan_for_master(c); 258 if (err) { 259 if (err == -EUCLEAN) 260 err = ubifs_recover_master_node(c); 261 if (err) 262 /* 263 * Note, we do not free 'c->mst_node' here because the 264 * unmount routine will take care of this. 265 */ 266 return err; 267 } 268 269 /* Make sure that the recovery flag is clear */ 270 c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY); 271 272 c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum); 273 c->highest_inum = le64_to_cpu(c->mst_node->highest_inum); 274 c->cmt_no = le64_to_cpu(c->mst_node->cmt_no); 275 c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum); 276 c->zroot.offs = le32_to_cpu(c->mst_node->root_offs); 277 c->zroot.len = le32_to_cpu(c->mst_node->root_len); 278 c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum); 279 c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum); 280 c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum); 281 c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs); 282 c->bi.old_idx_sz = le64_to_cpu(c->mst_node->index_size); 283 c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum); 284 c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs); 285 c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum); 286 c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs); 287 c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum); 288 c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs); 289 c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum); 290 c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs); 291 c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum); 292 c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs); 293 c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs); 294 old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt); 295 c->lst.total_free = le64_to_cpu(c->mst_node->total_free); 296 c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty); 297 c->lst.total_used = le64_to_cpu(c->mst_node->total_used); 298 c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead); 299 c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark); 300 301 c->calc_idx_sz = c->bi.old_idx_sz; 302 303 if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS)) 304 c->no_orphs = 1; 305 306 if (old_leb_cnt != c->leb_cnt) { 307 /* The file system has been resized */ 308 int growth = c->leb_cnt - old_leb_cnt; 309 310 if (c->leb_cnt < old_leb_cnt || 311 c->leb_cnt < UBIFS_MIN_LEB_CNT) { 312 ubifs_err(c, "bad leb_cnt on master node"); 313 ubifs_dump_node(c, c->mst_node); 314 return -EINVAL; 315 } 316 317 dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs", 318 old_leb_cnt, c->leb_cnt); 319 c->lst.empty_lebs += growth; 320 c->lst.total_free += growth * (long long)c->leb_size; 321 c->lst.total_dark += growth * (long long)c->dark_wm; 322 323 /* 324 * Reflect changes back onto the master node. N.B. the master 325 * node gets written immediately whenever mounting (or 326 * remounting) in read-write mode, so we do not need to write it 327 * here. 328 */ 329 c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt); 330 c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs); 331 c->mst_node->total_free = cpu_to_le64(c->lst.total_free); 332 c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark); 333 } 334 335 err = validate_master(c); 336 if (err) 337 return err; 338 339 #ifndef __UBOOT__ 340 err = dbg_old_index_check_init(c, &c->zroot); 341 #endif 342 343 return err; 344 } 345 346 #ifndef __UBOOT__ 347 /** 348 * ubifs_write_master - write master node. 349 * @c: UBIFS file-system description object 350 * 351 * This function writes the master node. Returns zero in case of success and a 352 * negative error code in case of failure. The master node is written twice to 353 * enable recovery. 354 */ 355 int ubifs_write_master(struct ubifs_info *c) 356 { 357 int err, lnum, offs, len; 358 359 ubifs_assert(!c->ro_media && !c->ro_mount); 360 if (c->ro_error) 361 return -EROFS; 362 363 lnum = UBIFS_MST_LNUM; 364 offs = c->mst_offs + c->mst_node_alsz; 365 len = UBIFS_MST_NODE_SZ; 366 367 if (offs + UBIFS_MST_NODE_SZ > c->leb_size) { 368 err = ubifs_leb_unmap(c, lnum); 369 if (err) 370 return err; 371 offs = 0; 372 } 373 374 c->mst_offs = offs; 375 c->mst_node->highest_inum = cpu_to_le64(c->highest_inum); 376 377 err = ubifs_write_node(c, c->mst_node, len, lnum, offs); 378 if (err) 379 return err; 380 381 lnum += 1; 382 383 if (offs == 0) { 384 err = ubifs_leb_unmap(c, lnum); 385 if (err) 386 return err; 387 } 388 err = ubifs_write_node(c, c->mst_node, len, lnum, offs); 389 390 return err; 391 } 392 #endif 393