fs/ubifs/master.c

   1 /*
   2  * This file is part of UBIFS.
   3  *
   4  * Copyright (C) 2006-2008 Nokia Corporation.
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  *
   8  * Authors: Artem Bityutskiy (Битюцкий Артём)
   9  *          Adrian Hunter
  10  */
  11
  12 /* This file implements reading and writing the master node */
  13
  14 #define __UBOOT__
  15 #include "ubifs.h"
  16 #ifdef __UBOOT__
  17 #include <linux/compat.h>
  18 #include <linux/err.h>
  19 #include <ubi_uboot.h>
  20 #endif
  21
  22 /**
  23  * scan_for_master - search the valid master node.
  24  * @c: UBIFS file-system description object
  25  *
  26  * This function scans the master node LEBs and search for the latest master
  27  * node. Returns zero in case of success, %-EUCLEAN if there master area is
  28  * corrupted and requires recovery, and a negative error code in case of
  29  * failure.
  30  */
  31 static int scan_for_master(struct ubifs_info *c)
  32 {
  33         struct ubifs_scan_leb *sleb;
  34         struct ubifs_scan_node *snod;
  35         int lnum, offs = 0, nodes_cnt;
  36
  37         lnum = UBIFS_MST_LNUM;
  38
  39         sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
  40         if (IS_ERR(sleb))
  41                 return PTR_ERR(sleb);
  42         nodes_cnt = sleb->nodes_cnt;
  43         if (nodes_cnt > 0) {
  44                 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
  45                                   list);
  46                 if (snod->type != UBIFS_MST_NODE)
  47                         goto out_dump;
  48                 memcpy(c->mst_node, snod->node, snod->len);
  49                 offs = snod->offs;
  50         }
  51         ubifs_scan_destroy(sleb);
  52
  53         lnum += 1;
  54
  55         sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
  56         if (IS_ERR(sleb))
  57                 return PTR_ERR(sleb);
  58         if (sleb->nodes_cnt != nodes_cnt)
  59                 goto out;
  60         if (!sleb->nodes_cnt)
  61                 goto out;
  62         snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
  63         if (snod->type != UBIFS_MST_NODE)
  64                 goto out_dump;
  65         if (snod->offs != offs)
  66                 goto out;
  67         if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
  68                    (void *)snod->node + UBIFS_CH_SZ,
  69                    UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
  70                 goto out;
  71         c->mst_offs = offs;
  72         ubifs_scan_destroy(sleb);
  73         return 0;
  74
  75 out:
  76         ubifs_scan_destroy(sleb);
  77         return -EUCLEAN;
  78
  79 out_dump:
  80         ubifs_err("unexpected node type %d master LEB %d:%d",
  81                   snod->type, lnum, snod->offs);
  82         ubifs_scan_destroy(sleb);
  83         return -EINVAL;
  84 }
  85
  86 /**
  87  * validate_master - validate master node.
  88  * @c: UBIFS file-system description object
  89  *
  90  * This function validates data which was read from master node. Returns zero
  91  * if the data is all right and %-EINVAL if not.
  92  */
  93 static int validate_master(const struct ubifs_info *c)
  94 {
  95         long long main_sz;
  96         int err;
  97
  98         if (c->max_sqnum >= SQNUM_WATERMARK) {
  99                 err = 1;
 100                 goto out;
 101         }
 102
 103         if (c->cmt_no >= c->max_sqnum) {
 104                 err = 2;
 105                 goto out;
 106         }
 107
 108         if (c->highest_inum >= INUM_WATERMARK) {
 109                 err = 3;
 110                 goto out;
 111         }
 112
 113         if (c->lhead_lnum < UBIFS_LOG_LNUM ||
 114             c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
 115             c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
 116             c->lhead_offs & (c->min_io_size - 1)) {
 117                 err = 4;
 118                 goto out;
 119         }
 120
 121         if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
 122             c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
 123                 err = 5;
 124                 goto out;
 125         }
 126
 127         if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
 128             c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
 129                 err = 6;
 130                 goto out;
 131         }
 132
 133         if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
 134                 err = 7;
 135                 goto out;
 136         }
 137
 138         if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
 139             c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
 140             c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
 141                 err = 8;
 142                 goto out;
 143         }
 144
 145         main_sz = (long long)c->main_lebs * c->leb_size;
 146         if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) {
 147                 err = 9;
 148                 goto out;
 149         }
 150
 151         if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
 152             c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
 153                 err = 10;
 154                 goto out;
 155         }
 156
 157         if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
 158             c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
 159             c->nhead_offs > c->leb_size) {
 160                 err = 11;
 161                 goto out;
 162         }
 163
 164         if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
 165             c->ltab_offs < 0 ||
 166             c->ltab_offs + c->ltab_sz > c->leb_size) {
 167                 err = 12;
 168                 goto out;
 169         }
 170
 171         if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
 172             c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
 173             c->lsave_offs + c->lsave_sz > c->leb_size)) {
 174                 err = 13;
 175                 goto out;
 176         }
 177
 178         if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
 179                 err = 14;
 180                 goto out;
 181         }
 182
 183         if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
 184                 err = 15;
 185                 goto out;
 186         }
 187
 188         if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
 189                 err = 16;
 190                 goto out;
 191         }
 192
 193         if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
 194             c->lst.total_free & 7) {
 195                 err = 17;
 196                 goto out;
 197         }
 198
 199         if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
 200                 err = 18;
 201                 goto out;
 202         }
 203
 204         if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
 205                 err = 19;
 206                 goto out;
 207         }
 208
 209         if (c->lst.total_free + c->lst.total_dirty +
 210             c->lst.total_used > main_sz) {
 211                 err = 20;
 212                 goto out;
 213         }
 214
 215         if (c->lst.total_dead + c->lst.total_dark +
 216             c->lst.total_used + c->bi.old_idx_sz > main_sz) {
 217                 err = 21;
 218                 goto out;
 219         }
 220
 221         if (c->lst.total_dead < 0 ||
 222             c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
 223             c->lst.total_dead & 7) {
 224                 err = 22;
 225                 goto out;
 226         }
 227
 228         if (c->lst.total_dark < 0 ||
 229             c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
 230             c->lst.total_dark & 7) {
 231                 err = 23;
 232                 goto out;
 233         }
 234
 235         return 0;
 236
 237 out:
 238         ubifs_err("bad master node at offset %d error %d", c->mst_offs, err);
 239         ubifs_dump_node(c, c->mst_node);
 240         return -EINVAL;
 241 }
 242
 243 /**
 244  * ubifs_read_master - read master node.
 245  * @c: UBIFS file-system description object
 246  *
 247  * This function finds and reads the master node during file-system mount. If
 248  * the flash is empty, it creates default master node as well. Returns zero in
 249  * case of success and a negative error code in case of failure.
 250  */
 251 int ubifs_read_master(struct ubifs_info *c)
 252 {
 253         int err, old_leb_cnt;
 254
 255         c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
 256         if (!c->mst_node)
 257                 return -ENOMEM;
 258
 259         err = scan_for_master(c);
 260         if (err) {
 261                 if (err == -EUCLEAN)
 262                         err = ubifs_recover_master_node(c);
 263                 if (err)
 264                         /*
 265                          * Note, we do not free 'c->mst_node' here because the
 266                          * unmount routine will take care of this.
 267                          */
 268                         return err;
 269         }
 270
 271         /* Make sure that the recovery flag is clear */
 272         c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
 273
 274         c->max_sqnum       = le64_to_cpu(c->mst_node->ch.sqnum);
 275         c->highest_inum    = le64_to_cpu(c->mst_node->highest_inum);
 276         c->cmt_no          = le64_to_cpu(c->mst_node->cmt_no);
 277         c->zroot.lnum      = le32_to_cpu(c->mst_node->root_lnum);
 278         c->zroot.offs      = le32_to_cpu(c->mst_node->root_offs);
 279         c->zroot.len       = le32_to_cpu(c->mst_node->root_len);
 280         c->lhead_lnum      = le32_to_cpu(c->mst_node->log_lnum);
 281         c->gc_lnum         = le32_to_cpu(c->mst_node->gc_lnum);
 282         c->ihead_lnum      = le32_to_cpu(c->mst_node->ihead_lnum);
 283         c->ihead_offs      = le32_to_cpu(c->mst_node->ihead_offs);
 284         c->bi.old_idx_sz   = le64_to_cpu(c->mst_node->index_size);
 285         c->lpt_lnum        = le32_to_cpu(c->mst_node->lpt_lnum);
 286         c->lpt_offs        = le32_to_cpu(c->mst_node->lpt_offs);
 287         c->nhead_lnum      = le32_to_cpu(c->mst_node->nhead_lnum);
 288         c->nhead_offs      = le32_to_cpu(c->mst_node->nhead_offs);
 289         c->ltab_lnum       = le32_to_cpu(c->mst_node->ltab_lnum);
 290         c->ltab_offs       = le32_to_cpu(c->mst_node->ltab_offs);
 291         c->lsave_lnum      = le32_to_cpu(c->mst_node->lsave_lnum);
 292         c->lsave_offs      = le32_to_cpu(c->mst_node->lsave_offs);
 293         c->lscan_lnum      = le32_to_cpu(c->mst_node->lscan_lnum);
 294         c->lst.empty_lebs  = le32_to_cpu(c->mst_node->empty_lebs);
 295         c->lst.idx_lebs    = le32_to_cpu(c->mst_node->idx_lebs);
 296         old_leb_cnt        = le32_to_cpu(c->mst_node->leb_cnt);
 297         c->lst.total_free  = le64_to_cpu(c->mst_node->total_free);
 298         c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
 299         c->lst.total_used  = le64_to_cpu(c->mst_node->total_used);
 300         c->lst.total_dead  = le64_to_cpu(c->mst_node->total_dead);
 301         c->lst.total_dark  = le64_to_cpu(c->mst_node->total_dark);
 302
 303         c->calc_idx_sz = c->bi.old_idx_sz;
 304
 305         if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
 306                 c->no_orphs = 1;
 307
 308         if (old_leb_cnt != c->leb_cnt) {
 309                 /* The file system has been resized */
 310                 int growth = c->leb_cnt - old_leb_cnt;
 311
 312                 if (c->leb_cnt < old_leb_cnt ||
 313                     c->leb_cnt < UBIFS_MIN_LEB_CNT) {
 314                         ubifs_err("bad leb_cnt on master node");
 315                         ubifs_dump_node(c, c->mst_node);
 316                         return -EINVAL;
 317                 }
 318
 319                 dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
 320                         old_leb_cnt, c->leb_cnt);
 321                 c->lst.empty_lebs += growth;
 322                 c->lst.total_free += growth * (long long)c->leb_size;
 323                 c->lst.total_dark += growth * (long long)c->dark_wm;
 324
 325                 /*
 326                  * Reflect changes back onto the master node. N.B. the master
 327                  * node gets written immediately whenever mounting (or
 328                  * remounting) in read-write mode, so we do not need to write it
 329                  * here.
 330                  */
 331                 c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
 332                 c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
 333                 c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
 334                 c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
 335         }
 336
 337         err = validate_master(c);
 338         if (err)
 339                 return err;
 340
 341 #ifndef __UBOOT__
 342         err = dbg_old_index_check_init(c, &c->zroot);
 343 #endif
 344
 345         return err;
 346 }
 347
 348 #ifndef __UBOOT__
 349 /**
 350  * ubifs_write_master - write master node.
 351  * @c: UBIFS file-system description object
 352  *
 353  * This function writes the master node. The caller has to take the
 354  * @c->mst_mutex lock before calling this function. Returns zero in case of
 355  * success and a negative error code in case of failure. The master node is
 356  * written twice to enable recovery.
 357  */
 358 int ubifs_write_master(struct ubifs_info *c)
 359 {
 360         int err, lnum, offs, len;
 361
 362         ubifs_assert(!c->ro_media && !c->ro_mount);
 363         if (c->ro_error)
 364                 return -EROFS;
 365
 366         lnum = UBIFS_MST_LNUM;
 367         offs = c->mst_offs + c->mst_node_alsz;
 368         len = UBIFS_MST_NODE_SZ;
 369
 370         if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
 371                 err = ubifs_leb_unmap(c, lnum);
 372                 if (err)
 373                         return err;
 374                 offs = 0;
 375         }
 376
 377         c->mst_offs = offs;
 378         c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
 379
 380         err = ubifs_write_node(c, c->mst_node, len, lnum, offs);
 381         if (err)
 382                 return err;
 383
 384         lnum += 1;
 385
 386         if (offs == 0) {
 387                 err = ubifs_leb_unmap(c, lnum);
 388                 if (err)
 389                         return err;
 390         }
 391         err = ubifs_write_node(c, c->mst_node, len, lnum, offs);
 392
 393         return err;
 394 }
 395 #endif