linux/fs/ubifs/super.c
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   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/*
  24 * This file implements UBIFS initialization and VFS superblock operations. Some
  25 * initialization stuff which is rather large and complex is placed at
  26 * corresponding subsystems, but most of it is here.
  27 */
  28
  29#include <linux/init.h>
  30#include <linux/slab.h>
  31#include <linux/module.h>
  32#include <linux/ctype.h>
  33#include <linux/kthread.h>
  34#include <linux/parser.h>
  35#include <linux/seq_file.h>
  36#include <linux/mount.h>
  37#include <linux/math64.h>
  38#include <linux/writeback.h>
  39#include "ubifs.h"
  40
  41/*
  42 * Maximum amount of memory we may 'kmalloc()' without worrying that we are
  43 * allocating too much.
  44 */
  45#define UBIFS_KMALLOC_OK (128*1024)
  46
  47/* Slab cache for UBIFS inodes */
  48struct kmem_cache *ubifs_inode_slab;
  49
  50/* UBIFS TNC shrinker description */
  51static struct shrinker ubifs_shrinker_info = {
  52        .shrink = ubifs_shrinker,
  53        .seeks = DEFAULT_SEEKS,
  54};
  55
  56/**
  57 * validate_inode - validate inode.
  58 * @c: UBIFS file-system description object
  59 * @inode: the inode to validate
  60 *
  61 * This is a helper function for 'ubifs_iget()' which validates various fields
  62 * of a newly built inode to make sure they contain sane values and prevent
  63 * possible vulnerabilities. Returns zero if the inode is all right and
  64 * a non-zero error code if not.
  65 */
  66static int validate_inode(struct ubifs_info *c, const struct inode *inode)
  67{
  68        int err;
  69        const struct ubifs_inode *ui = ubifs_inode(inode);
  70
  71        if (inode->i_size > c->max_inode_sz) {
  72                ubifs_err("inode is too large (%lld)",
  73                          (long long)inode->i_size);
  74                return 1;
  75        }
  76
  77        if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
  78                ubifs_err("unknown compression type %d", ui->compr_type);
  79                return 2;
  80        }
  81
  82        if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
  83                return 3;
  84
  85        if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
  86                return 4;
  87
  88        if (ui->xattr && !S_ISREG(inode->i_mode))
  89                return 5;
  90
  91        if (!ubifs_compr_present(ui->compr_type)) {
  92                ubifs_warn("inode %lu uses '%s' compression, but it was not "
  93                           "compiled in", inode->i_ino,
  94                           ubifs_compr_name(ui->compr_type));
  95        }
  96
  97        err = dbg_check_dir(c, inode);
  98        return err;
  99}
 100
 101struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 102{
 103        int err;
 104        union ubifs_key key;
 105        struct ubifs_ino_node *ino;
 106        struct ubifs_info *c = sb->s_fs_info;
 107        struct inode *inode;
 108        struct ubifs_inode *ui;
 109
 110        dbg_gen("inode %lu", inum);
 111
 112        inode = iget_locked(sb, inum);
 113        if (!inode)
 114                return ERR_PTR(-ENOMEM);
 115        if (!(inode->i_state & I_NEW))
 116                return inode;
 117        ui = ubifs_inode(inode);
 118
 119        ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
 120        if (!ino) {
 121                err = -ENOMEM;
 122                goto out;
 123        }
 124
 125        ino_key_init(c, &key, inode->i_ino);
 126
 127        err = ubifs_tnc_lookup(c, &key, ino);
 128        if (err)
 129                goto out_ino;
 130
 131        inode->i_flags |= (S_NOCMTIME | S_NOATIME);
 132        set_nlink(inode, le32_to_cpu(ino->nlink));
 133        inode->i_uid   = le32_to_cpu(ino->uid);
 134        inode->i_gid   = le32_to_cpu(ino->gid);
 135        inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
 136        inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
 137        inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
 138        inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
 139        inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
 140        inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
 141        inode->i_mode = le32_to_cpu(ino->mode);
 142        inode->i_size = le64_to_cpu(ino->size);
 143
 144        ui->data_len    = le32_to_cpu(ino->data_len);
 145        ui->flags       = le32_to_cpu(ino->flags);
 146        ui->compr_type  = le16_to_cpu(ino->compr_type);
 147        ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
 148        ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
 149        ui->xattr_size  = le32_to_cpu(ino->xattr_size);
 150        ui->xattr_names = le32_to_cpu(ino->xattr_names);
 151        ui->synced_i_size = ui->ui_size = inode->i_size;
 152
 153        ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
 154
 155        err = validate_inode(c, inode);
 156        if (err)
 157                goto out_invalid;
 158
 159        /* Disable read-ahead */
 160        inode->i_mapping->backing_dev_info = &c->bdi;
 161
 162        switch (inode->i_mode & S_IFMT) {
 163        case S_IFREG:
 164                inode->i_mapping->a_ops = &ubifs_file_address_operations;
 165                inode->i_op = &ubifs_file_inode_operations;
 166                inode->i_fop = &ubifs_file_operations;
 167                if (ui->xattr) {
 168                        ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 169                        if (!ui->data) {
 170                                err = -ENOMEM;
 171                                goto out_ino;
 172                        }
 173                        memcpy(ui->data, ino->data, ui->data_len);
 174                        ((char *)ui->data)[ui->data_len] = '\0';
 175                } else if (ui->data_len != 0) {
 176                        err = 10;
 177                        goto out_invalid;
 178                }
 179                break;
 180        case S_IFDIR:
 181                inode->i_op  = &ubifs_dir_inode_operations;
 182                inode->i_fop = &ubifs_dir_operations;
 183                if (ui->data_len != 0) {
 184                        err = 11;
 185                        goto out_invalid;
 186                }
 187                break;
 188        case S_IFLNK:
 189                inode->i_op = &ubifs_symlink_inode_operations;
 190                if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
 191                        err = 12;
 192                        goto out_invalid;
 193                }
 194                ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 195                if (!ui->data) {
 196                        err = -ENOMEM;
 197                        goto out_ino;
 198                }
 199                memcpy(ui->data, ino->data, ui->data_len);
 200                ((char *)ui->data)[ui->data_len] = '\0';
 201                break;
 202        case S_IFBLK:
 203        case S_IFCHR:
 204        {
 205                dev_t rdev;
 206                union ubifs_dev_desc *dev;
 207
 208                ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
 209                if (!ui->data) {
 210                        err = -ENOMEM;
 211                        goto out_ino;
 212                }
 213
 214                dev = (union ubifs_dev_desc *)ino->data;
 215                if (ui->data_len == sizeof(dev->new))
 216                        rdev = new_decode_dev(le32_to_cpu(dev->new));
 217                else if (ui->data_len == sizeof(dev->huge))
 218                        rdev = huge_decode_dev(le64_to_cpu(dev->huge));
 219                else {
 220                        err = 13;
 221                        goto out_invalid;
 222                }
 223                memcpy(ui->data, ino->data, ui->data_len);
 224                inode->i_op = &ubifs_file_inode_operations;
 225                init_special_inode(inode, inode->i_mode, rdev);
 226                break;
 227        }
 228        case S_IFSOCK:
 229        case S_IFIFO:
 230                inode->i_op = &ubifs_file_inode_operations;
 231                init_special_inode(inode, inode->i_mode, 0);
 232                if (ui->data_len != 0) {
 233                        err = 14;
 234                        goto out_invalid;
 235                }
 236                break;
 237        default:
 238                err = 15;
 239                goto out_invalid;
 240        }
 241
 242        kfree(ino);
 243        ubifs_set_inode_flags(inode);
 244        unlock_new_inode(inode);
 245        return inode;
 246
 247out_invalid:
 248        ubifs_err("inode %lu validation failed, error %d", inode->i_ino, err);
 249        ubifs_dump_node(c, ino);
 250        ubifs_dump_inode(c, inode);
 251        err = -EINVAL;
 252out_ino:
 253        kfree(ino);
 254out:
 255        ubifs_err("failed to read inode %lu, error %d", inode->i_ino, err);
 256        iget_failed(inode);
 257        return ERR_PTR(err);
 258}
 259
 260static struct inode *ubifs_alloc_inode(struct super_block *sb)
 261{
 262        struct ubifs_inode *ui;
 263
 264        ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
 265        if (!ui)
 266                return NULL;
 267
 268        memset((void *)ui + sizeof(struct inode), 0,
 269               sizeof(struct ubifs_inode) - sizeof(struct inode));
 270        mutex_init(&ui->ui_mutex);
 271        spin_lock_init(&ui->ui_lock);
 272        return &ui->vfs_inode;
 273};
 274
 275static void ubifs_i_callback(struct rcu_head *head)
 276{
 277        struct inode *inode = container_of(head, struct inode, i_rcu);
 278        struct ubifs_inode *ui = ubifs_inode(inode);
 279        kmem_cache_free(ubifs_inode_slab, ui);
 280}
 281
 282static void ubifs_destroy_inode(struct inode *inode)
 283{
 284        struct ubifs_inode *ui = ubifs_inode(inode);
 285
 286        kfree(ui->data);
 287        call_rcu(&inode->i_rcu, ubifs_i_callback);
 288}
 289
 290/*
 291 * Note, Linux write-back code calls this without 'i_mutex'.
 292 */
 293static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
 294{
 295        int err = 0;
 296        struct ubifs_info *c = inode->i_sb->s_fs_info;
 297        struct ubifs_inode *ui = ubifs_inode(inode);
 298
 299        ubifs_assert(!ui->xattr);
 300        if (is_bad_inode(inode))
 301                return 0;
 302
 303        mutex_lock(&ui->ui_mutex);
 304        /*
 305         * Due to races between write-back forced by budgeting
 306         * (see 'sync_some_inodes()') and background write-back, the inode may
 307         * have already been synchronized, do not do this again. This might
 308         * also happen if it was synchronized in an VFS operation, e.g.
 309         * 'ubifs_link()'.
 310         */
 311        if (!ui->dirty) {
 312                mutex_unlock(&ui->ui_mutex);
 313                return 0;
 314        }
 315
 316        /*
 317         * As an optimization, do not write orphan inodes to the media just
 318         * because this is not needed.
 319         */
 320        dbg_gen("inode %lu, mode %#x, nlink %u",
 321                inode->i_ino, (int)inode->i_mode, inode->i_nlink);
 322        if (inode->i_nlink) {
 323                err = ubifs_jnl_write_inode(c, inode);
 324                if (err)
 325                        ubifs_err("can't write inode %lu, error %d",
 326                                  inode->i_ino, err);
 327                else
 328                        err = dbg_check_inode_size(c, inode, ui->ui_size);
 329        }
 330
 331        ui->dirty = 0;
 332        mutex_unlock(&ui->ui_mutex);
 333        ubifs_release_dirty_inode_budget(c, ui);
 334        return err;
 335}
 336
 337static void ubifs_evict_inode(struct inode *inode)
 338{
 339        int err;
 340        struct ubifs_info *c = inode->i_sb->s_fs_info;
 341        struct ubifs_inode *ui = ubifs_inode(inode);
 342
 343        if (ui->xattr)
 344                /*
 345                 * Extended attribute inode deletions are fully handled in
 346                 * 'ubifs_removexattr()'. These inodes are special and have
 347                 * limited usage, so there is nothing to do here.
 348                 */
 349                goto out;
 350
 351        dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
 352        ubifs_assert(!atomic_read(&inode->i_count));
 353
 354        truncate_inode_pages(&inode->i_data, 0);
 355
 356        if (inode->i_nlink)
 357                goto done;
 358
 359        if (is_bad_inode(inode))
 360                goto out;
 361
 362        ui->ui_size = inode->i_size = 0;
 363        err = ubifs_jnl_delete_inode(c, inode);
 364        if (err)
 365                /*
 366                 * Worst case we have a lost orphan inode wasting space, so a
 367                 * simple error message is OK here.
 368                 */
 369                ubifs_err("can't delete inode %lu, error %d",
 370                          inode->i_ino, err);
 371
 372out:
 373        if (ui->dirty)
 374                ubifs_release_dirty_inode_budget(c, ui);
 375        else {
 376                /* We've deleted something - clean the "no space" flags */
 377                c->bi.nospace = c->bi.nospace_rp = 0;
 378                smp_wmb();
 379        }
 380done:
 381        clear_inode(inode);
 382}
 383
 384static void ubifs_dirty_inode(struct inode *inode, int flags)
 385{
 386        struct ubifs_inode *ui = ubifs_inode(inode);
 387
 388        ubifs_assert(mutex_is_locked(&ui->ui_mutex));
 389        if (!ui->dirty) {
 390                ui->dirty = 1;
 391                dbg_gen("inode %lu",  inode->i_ino);
 392        }
 393}
 394
 395static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
 396{
 397        struct ubifs_info *c = dentry->d_sb->s_fs_info;
 398        unsigned long long free;
 399        __le32 *uuid = (__le32 *)c->uuid;
 400
 401        free = ubifs_get_free_space(c);
 402        dbg_gen("free space %lld bytes (%lld blocks)",
 403                free, free >> UBIFS_BLOCK_SHIFT);
 404
 405        buf->f_type = UBIFS_SUPER_MAGIC;
 406        buf->f_bsize = UBIFS_BLOCK_SIZE;
 407        buf->f_blocks = c->block_cnt;
 408        buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
 409        if (free > c->report_rp_size)
 410                buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
 411        else
 412                buf->f_bavail = 0;
 413        buf->f_files = 0;
 414        buf->f_ffree = 0;
 415        buf->f_namelen = UBIFS_MAX_NLEN;
 416        buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
 417        buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
 418        ubifs_assert(buf->f_bfree <= c->block_cnt);
 419        return 0;
 420}
 421
 422static int ubifs_show_options(struct seq_file *s, struct dentry *root)
 423{
 424        struct ubifs_info *c = root->d_sb->s_fs_info;
 425
 426        if (c->mount_opts.unmount_mode == 2)
 427                seq_printf(s, ",fast_unmount");
 428        else if (c->mount_opts.unmount_mode == 1)
 429                seq_printf(s, ",norm_unmount");
 430
 431        if (c->mount_opts.bulk_read == 2)
 432                seq_printf(s, ",bulk_read");
 433        else if (c->mount_opts.bulk_read == 1)
 434                seq_printf(s, ",no_bulk_read");
 435
 436        if (c->mount_opts.chk_data_crc == 2)
 437                seq_printf(s, ",chk_data_crc");
 438        else if (c->mount_opts.chk_data_crc == 1)
 439                seq_printf(s, ",no_chk_data_crc");
 440
 441        if (c->mount_opts.override_compr) {
 442                seq_printf(s, ",compr=%s",
 443                           ubifs_compr_name(c->mount_opts.compr_type));
 444        }
 445
 446        return 0;
 447}
 448
 449static int ubifs_sync_fs(struct super_block *sb, int wait)
 450{
 451        int i, err;
 452        struct ubifs_info *c = sb->s_fs_info;
 453
 454        /*
 455         * Zero @wait is just an advisory thing to help the file system shove
 456         * lots of data into the queues, and there will be the second
 457         * '->sync_fs()' call, with non-zero @wait.
 458         */
 459        if (!wait)
 460                return 0;
 461
 462        /*
 463         * Synchronize write buffers, because 'ubifs_run_commit()' does not
 464         * do this if it waits for an already running commit.
 465         */
 466        for (i = 0; i < c->jhead_cnt; i++) {
 467                err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
 468                if (err)
 469                        return err;
 470        }
 471
 472        /*
 473         * Strictly speaking, it is not necessary to commit the journal here,
 474         * synchronizing write-buffers would be enough. But committing makes
 475         * UBIFS free space predictions much more accurate, so we want to let
 476         * the user be able to get more accurate results of 'statfs()' after
 477         * they synchronize the file system.
 478         */
 479        err = ubifs_run_commit(c);
 480        if (err)
 481                return err;
 482
 483        return ubi_sync(c->vi.ubi_num);
 484}
 485
 486/**
 487 * init_constants_early - initialize UBIFS constants.
 488 * @c: UBIFS file-system description object
 489 *
 490 * This function initialize UBIFS constants which do not need the superblock to
 491 * be read. It also checks that the UBI volume satisfies basic UBIFS
 492 * requirements. Returns zero in case of success and a negative error code in
 493 * case of failure.
 494 */
 495static int init_constants_early(struct ubifs_info *c)
 496{
 497        if (c->vi.corrupted) {
 498                ubifs_warn("UBI volume is corrupted - read-only mode");
 499                c->ro_media = 1;
 500        }
 501
 502        if (c->di.ro_mode) {
 503                ubifs_msg("read-only UBI device");
 504                c->ro_media = 1;
 505        }
 506
 507        if (c->vi.vol_type == UBI_STATIC_VOLUME) {
 508                ubifs_msg("static UBI volume - read-only mode");
 509                c->ro_media = 1;
 510        }
 511
 512        c->leb_cnt = c->vi.size;
 513        c->leb_size = c->vi.usable_leb_size;
 514        c->leb_start = c->di.leb_start;
 515        c->half_leb_size = c->leb_size / 2;
 516        c->min_io_size = c->di.min_io_size;
 517        c->min_io_shift = fls(c->min_io_size) - 1;
 518        c->max_write_size = c->di.max_write_size;
 519        c->max_write_shift = fls(c->max_write_size) - 1;
 520
 521        if (c->leb_size < UBIFS_MIN_LEB_SZ) {
 522                ubifs_err("too small LEBs (%d bytes), min. is %d bytes",
 523                          c->leb_size, UBIFS_MIN_LEB_SZ);
 524                return -EINVAL;
 525        }
 526
 527        if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
 528                ubifs_err("too few LEBs (%d), min. is %d",
 529                          c->leb_cnt, UBIFS_MIN_LEB_CNT);
 530                return -EINVAL;
 531        }
 532
 533        if (!is_power_of_2(c->min_io_size)) {
 534                ubifs_err("bad min. I/O size %d", c->min_io_size);
 535                return -EINVAL;
 536        }
 537
 538        /*
 539         * Maximum write size has to be greater or equivalent to min. I/O
 540         * size, and be multiple of min. I/O size.
 541         */
 542        if (c->max_write_size < c->min_io_size ||
 543            c->max_write_size % c->min_io_size ||
 544            !is_power_of_2(c->max_write_size)) {
 545                ubifs_err("bad write buffer size %d for %d min. I/O unit",
 546                          c->max_write_size, c->min_io_size);
 547                return -EINVAL;
 548        }
 549
 550        /*
 551         * UBIFS aligns all node to 8-byte boundary, so to make function in
 552         * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
 553         * less than 8.
 554         */
 555        if (c->min_io_size < 8) {
 556                c->min_io_size = 8;
 557                c->min_io_shift = 3;
 558                if (c->max_write_size < c->min_io_size) {
 559                        c->max_write_size = c->min_io_size;
 560                        c->max_write_shift = c->min_io_shift;
 561                }
 562        }
 563
 564        c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
 565        c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
 566
 567        /*
 568         * Initialize node length ranges which are mostly needed for node
 569         * length validation.
 570         */
 571        c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
 572        c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
 573        c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
 574        c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
 575        c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
 576        c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
 577
 578        c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
 579        c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
 580        c->ranges[UBIFS_ORPH_NODE].min_len =
 581                                UBIFS_ORPH_NODE_SZ + sizeof(__le64);
 582        c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
 583        c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
 584        c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
 585        c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
 586        c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
 587        c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
 588        c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
 589        /*
 590         * Minimum indexing node size is amended later when superblock is
 591         * read and the key length is known.
 592         */
 593        c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
 594        /*
 595         * Maximum indexing node size is amended later when superblock is
 596         * read and the fanout is known.
 597         */
 598        c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
 599
 600        /*
 601         * Initialize dead and dark LEB space watermarks. See gc.c for comments
 602         * about these values.
 603         */
 604        c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
 605        c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
 606
 607        /*
 608         * Calculate how many bytes would be wasted at the end of LEB if it was
 609         * fully filled with data nodes of maximum size. This is used in
 610         * calculations when reporting free space.
 611         */
 612        c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
 613
 614        /* Buffer size for bulk-reads */
 615        c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
 616        if (c->max_bu_buf_len > c->leb_size)
 617                c->max_bu_buf_len = c->leb_size;
 618        return 0;
 619}
 620
 621/**
 622 * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
 623 * @c: UBIFS file-system description object
 624 * @lnum: LEB the write-buffer was synchronized to
 625 * @free: how many free bytes left in this LEB
 626 * @pad: how many bytes were padded
 627 *
 628 * This is a callback function which is called by the I/O unit when the
 629 * write-buffer is synchronized. We need this to correctly maintain space
 630 * accounting in bud logical eraseblocks. This function returns zero in case of
 631 * success and a negative error code in case of failure.
 632 *
 633 * This function actually belongs to the journal, but we keep it here because
 634 * we want to keep it static.
 635 */
 636static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
 637{
 638        return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
 639}
 640
 641/*
 642 * init_constants_sb - initialize UBIFS constants.
 643 * @c: UBIFS file-system description object
 644 *
 645 * This is a helper function which initializes various UBIFS constants after
 646 * the superblock has been read. It also checks various UBIFS parameters and
 647 * makes sure they are all right. Returns zero in case of success and a
 648 * negative error code in case of failure.
 649 */
 650static int init_constants_sb(struct ubifs_info *c)
 651{
 652        int tmp, err;
 653        long long tmp64;
 654
 655        c->main_bytes = (long long)c->main_lebs * c->leb_size;
 656        c->max_znode_sz = sizeof(struct ubifs_znode) +
 657                                c->fanout * sizeof(struct ubifs_zbranch);
 658
 659        tmp = ubifs_idx_node_sz(c, 1);
 660        c->ranges[UBIFS_IDX_NODE].min_len = tmp;
 661        c->min_idx_node_sz = ALIGN(tmp, 8);
 662
 663        tmp = ubifs_idx_node_sz(c, c->fanout);
 664        c->ranges[UBIFS_IDX_NODE].max_len = tmp;
 665        c->max_idx_node_sz = ALIGN(tmp, 8);
 666
 667        /* Make sure LEB size is large enough to fit full commit */
 668        tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
 669        tmp = ALIGN(tmp, c->min_io_size);
 670        if (tmp > c->leb_size) {
 671                ubifs_err("too small LEB size %d, at least %d needed",
 672                          c->leb_size, tmp);
 673                return -EINVAL;
 674        }
 675
 676        /*
 677         * Make sure that the log is large enough to fit reference nodes for
 678         * all buds plus one reserved LEB.
 679         */
 680        tmp64 = c->max_bud_bytes + c->leb_size - 1;
 681        c->max_bud_cnt = div_u64(tmp64, c->leb_size);
 682        tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
 683        tmp /= c->leb_size;
 684        tmp += 1;
 685        if (c->log_lebs < tmp) {
 686                ubifs_err("too small log %d LEBs, required min. %d LEBs",
 687                          c->log_lebs, tmp);
 688                return -EINVAL;
 689        }
 690
 691        /*
 692         * When budgeting we assume worst-case scenarios when the pages are not
 693         * be compressed and direntries are of the maximum size.
 694         *
 695         * Note, data, which may be stored in inodes is budgeted separately, so
 696         * it is not included into 'c->bi.inode_budget'.
 697         */
 698        c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
 699        c->bi.inode_budget = UBIFS_INO_NODE_SZ;
 700        c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
 701
 702        /*
 703         * When the amount of flash space used by buds becomes
 704         * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
 705         * The writers are unblocked when the commit is finished. To avoid
 706         * writers to be blocked UBIFS initiates background commit in advance,
 707         * when number of bud bytes becomes above the limit defined below.
 708         */
 709        c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
 710
 711        /*
 712         * Ensure minimum journal size. All the bytes in the journal heads are
 713         * considered to be used, when calculating the current journal usage.
 714         * Consequently, if the journal is too small, UBIFS will treat it as
 715         * always full.
 716         */
 717        tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
 718        if (c->bg_bud_bytes < tmp64)
 719                c->bg_bud_bytes = tmp64;
 720        if (c->max_bud_bytes < tmp64 + c->leb_size)
 721                c->max_bud_bytes = tmp64 + c->leb_size;
 722
 723        err = ubifs_calc_lpt_geom(c);
 724        if (err)
 725                return err;
 726
 727        /* Initialize effective LEB size used in budgeting calculations */
 728        c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
 729        return 0;
 730}
 731
 732/*
 733 * init_constants_master - initialize UBIFS constants.
 734 * @c: UBIFS file-system description object
 735 *
 736 * This is a helper function which initializes various UBIFS constants after
 737 * the master node has been read. It also checks various UBIFS parameters and
 738 * makes sure they are all right.
 739 */
 740static void init_constants_master(struct ubifs_info *c)
 741{
 742        long long tmp64;
 743
 744        c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 745        c->report_rp_size = ubifs_reported_space(c, c->rp_size);
 746
 747        /*
 748         * Calculate total amount of FS blocks. This number is not used
 749         * internally because it does not make much sense for UBIFS, but it is
 750         * necessary to report something for the 'statfs()' call.
 751         *
 752         * Subtract the LEB reserved for GC, the LEB which is reserved for
 753         * deletions, minimum LEBs for the index, and assume only one journal
 754         * head is available.
 755         */
 756        tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
 757        tmp64 *= (long long)c->leb_size - c->leb_overhead;
 758        tmp64 = ubifs_reported_space(c, tmp64);
 759        c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
 760}
 761
 762/**
 763 * take_gc_lnum - reserve GC LEB.
 764 * @c: UBIFS file-system description object
 765 *
 766 * This function ensures that the LEB reserved for garbage collection is marked
 767 * as "taken" in lprops. We also have to set free space to LEB size and dirty
 768 * space to zero, because lprops may contain out-of-date information if the
 769 * file-system was un-mounted before it has been committed. This function
 770 * returns zero in case of success and a negative error code in case of
 771 * failure.
 772 */
 773static int take_gc_lnum(struct ubifs_info *c)
 774{
 775        int err;
 776
 777        if (c->gc_lnum == -1) {
 778                ubifs_err("no LEB for GC");
 779                return -EINVAL;
 780        }
 781
 782        /* And we have to tell lprops that this LEB is taken */
 783        err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
 784                                  LPROPS_TAKEN, 0, 0);
 785        return err;
 786}
 787
 788/**
 789 * alloc_wbufs - allocate write-buffers.
 790 * @c: UBIFS file-system description object
 791 *
 792 * This helper function allocates and initializes UBIFS write-buffers. Returns
 793 * zero in case of success and %-ENOMEM in case of failure.
 794 */
 795static int alloc_wbufs(struct ubifs_info *c)
 796{
 797        int i, err;
 798
 799        c->jheads = kzalloc(c->jhead_cnt * sizeof(struct ubifs_jhead),
 800                           GFP_KERNEL);
 801        if (!c->jheads)
 802                return -ENOMEM;
 803
 804        /* Initialize journal heads */
 805        for (i = 0; i < c->jhead_cnt; i++) {
 806                INIT_LIST_HEAD(&c->jheads[i].buds_list);
 807                err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
 808                if (err)
 809                        return err;
 810
 811                c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
 812                c->jheads[i].wbuf.jhead = i;
 813                c->jheads[i].grouped = 1;
 814        }
 815
 816        /*
 817         * Garbage Collector head does not need to be synchronized by timer.
 818         * Also GC head nodes are not grouped.
 819         */
 820        c->jheads[GCHD].wbuf.no_timer = 1;
 821        c->jheads[GCHD].grouped = 0;
 822
 823        return 0;
 824}
 825
 826/**
 827 * free_wbufs - free write-buffers.
 828 * @c: UBIFS file-system description object
 829 */
 830static void free_wbufs(struct ubifs_info *c)
 831{
 832        int i;
 833
 834        if (c->jheads) {
 835                for (i = 0; i < c->jhead_cnt; i++) {
 836                        kfree(c->jheads[i].wbuf.buf);
 837                        kfree(c->jheads[i].wbuf.inodes);
 838                }
 839                kfree(c->jheads);
 840                c->jheads = NULL;
 841        }
 842}
 843
 844/**
 845 * free_orphans - free orphans.
 846 * @c: UBIFS file-system description object
 847 */
 848static void free_orphans(struct ubifs_info *c)
 849{
 850        struct ubifs_orphan *orph;
 851
 852        while (c->orph_dnext) {
 853                orph = c->orph_dnext;
 854                c->orph_dnext = orph->dnext;
 855                list_del(&orph->list);
 856                kfree(orph);
 857        }
 858
 859        while (!list_empty(&c->orph_list)) {
 860                orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
 861                list_del(&orph->list);
 862                kfree(orph);
 863                ubifs_err("orphan list not empty at unmount");
 864        }
 865
 866        vfree(c->orph_buf);
 867        c->orph_buf = NULL;
 868}
 869
 870/**
 871 * free_buds - free per-bud objects.
 872 * @c: UBIFS file-system description object
 873 */
 874static void free_buds(struct ubifs_info *c)
 875{
 876        struct rb_node *this = c->buds.rb_node;
 877        struct ubifs_bud *bud;
 878
 879        while (this) {
 880                if (this->rb_left)
 881                        this = this->rb_left;
 882                else if (this->rb_right)
 883                        this = this->rb_right;
 884                else {
 885                        bud = rb_entry(this, struct ubifs_bud, rb);
 886                        this = rb_parent(this);
 887                        if (this) {
 888                                if (this->rb_left == &bud->rb)
 889                                        this->rb_left = NULL;
 890                                else
 891                                        this->rb_right = NULL;
 892                        }
 893                        kfree(bud);
 894                }
 895        }
 896}
 897
 898/**
 899 * check_volume_empty - check if the UBI volume is empty.
 900 * @c: UBIFS file-system description object
 901 *
 902 * This function checks if the UBIFS volume is empty by looking if its LEBs are
 903 * mapped or not. The result of checking is stored in the @c->empty variable.
 904 * Returns zero in case of success and a negative error code in case of
 905 * failure.
 906 */
 907static int check_volume_empty(struct ubifs_info *c)
 908{
 909        int lnum, err;
 910
 911        c->empty = 1;
 912        for (lnum = 0; lnum < c->leb_cnt; lnum++) {
 913                err = ubifs_is_mapped(c, lnum);
 914                if (unlikely(err < 0))
 915                        return err;
 916                if (err == 1) {
 917                        c->empty = 0;
 918                        break;
 919                }
 920
 921                cond_resched();
 922        }
 923
 924        return 0;
 925}
 926
 927/*
 928 * UBIFS mount options.
 929 *
 930 * Opt_fast_unmount: do not run a journal commit before un-mounting
 931 * Opt_norm_unmount: run a journal commit before un-mounting
 932 * Opt_bulk_read: enable bulk-reads
 933 * Opt_no_bulk_read: disable bulk-reads
 934 * Opt_chk_data_crc: check CRCs when reading data nodes
 935 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
 936 * Opt_override_compr: override default compressor
 937 * Opt_err: just end of array marker
 938 */
 939enum {
 940        Opt_fast_unmount,
 941        Opt_norm_unmount,
 942        Opt_bulk_read,
 943        Opt_no_bulk_read,
 944        Opt_chk_data_crc,
 945        Opt_no_chk_data_crc,
 946        Opt_override_compr,
 947        Opt_err,
 948};
 949
 950static const match_table_t tokens = {
 951        {Opt_fast_unmount, "fast_unmount"},
 952        {Opt_norm_unmount, "norm_unmount"},
 953        {Opt_bulk_read, "bulk_read"},
 954        {Opt_no_bulk_read, "no_bulk_read"},
 955        {Opt_chk_data_crc, "chk_data_crc"},
 956        {Opt_no_chk_data_crc, "no_chk_data_crc"},
 957        {Opt_override_compr, "compr=%s"},
 958        {Opt_err, NULL},
 959};
 960
 961/**
 962 * parse_standard_option - parse a standard mount option.
 963 * @option: the option to parse
 964 *
 965 * Normally, standard mount options like "sync" are passed to file-systems as
 966 * flags. However, when a "rootflags=" kernel boot parameter is used, they may
 967 * be present in the options string. This function tries to deal with this
 968 * situation and parse standard options. Returns 0 if the option was not
 969 * recognized, and the corresponding integer flag if it was.
 970 *
 971 * UBIFS is only interested in the "sync" option, so do not check for anything
 972 * else.
 973 */
 974static int parse_standard_option(const char *option)
 975{
 976        ubifs_msg("parse %s", option);
 977        if (!strcmp(option, "sync"))
 978                return MS_SYNCHRONOUS;
 979        return 0;
 980}
 981
 982/**
 983 * ubifs_parse_options - parse mount parameters.
 984 * @c: UBIFS file-system description object
 985 * @options: parameters to parse
 986 * @is_remount: non-zero if this is FS re-mount
 987 *
 988 * This function parses UBIFS mount options and returns zero in case success
 989 * and a negative error code in case of failure.
 990 */
 991static int ubifs_parse_options(struct ubifs_info *c, char *options,
 992                               int is_remount)
 993{
 994        char *p;
 995        substring_t args[MAX_OPT_ARGS];
 996
 997        if (!options)
 998                return 0;
 999
1000        while ((p = strsep(&options, ","))) {
1001                int token;
1002
1003                if (!*p)
1004                        continue;
1005
1006                token = match_token(p, tokens, args);
1007                switch (token) {
1008                /*
1009                 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1010                 * We accept them in order to be backward-compatible. But this
1011                 * should be removed at some point.
1012                 */
1013                case Opt_fast_unmount:
1014                        c->mount_opts.unmount_mode = 2;
1015                        break;
1016                case Opt_norm_unmount:
1017                        c->mount_opts.unmount_mode = 1;
1018                        break;
1019                case Opt_bulk_read:
1020                        c->mount_opts.bulk_read = 2;
1021                        c->bulk_read = 1;
1022                        break;
1023                case Opt_no_bulk_read:
1024                        c->mount_opts.bulk_read = 1;
1025                        c->bulk_read = 0;
1026                        break;
1027                case Opt_chk_data_crc:
1028                        c->mount_opts.chk_data_crc = 2;
1029                        c->no_chk_data_crc = 0;
1030                        break;
1031                case Opt_no_chk_data_crc:
1032                        c->mount_opts.chk_data_crc = 1;
1033                        c->no_chk_data_crc = 1;
1034                        break;
1035                case Opt_override_compr:
1036                {
1037                        char *name = match_strdup(&args[0]);
1038
1039                        if (!name)
1040                                return -ENOMEM;
1041                        if (!strcmp(name, "none"))
1042                                c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1043                        else if (!strcmp(name, "lzo"))
1044                                c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1045                        else if (!strcmp(name, "zlib"))
1046                                c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1047                        else {
1048                                ubifs_err("unknown compressor \"%s\"", name);
1049                                kfree(name);
1050                                return -EINVAL;
1051                        }
1052                        kfree(name);
1053                        c->mount_opts.override_compr = 1;
1054                        c->default_compr = c->mount_opts.compr_type;
1055                        break;
1056                }
1057                default:
1058                {
1059                        unsigned long flag;
1060                        struct super_block *sb = c->vfs_sb;
1061
1062                        flag = parse_standard_option(p);
1063                        if (!flag) {
1064                                ubifs_err("unrecognized mount option \"%s\" "
1065                                          "or missing value", p);
1066                                return -EINVAL;
1067                        }
1068                        sb->s_flags |= flag;
1069                        break;
1070                }
1071                }
1072        }
1073
1074        return 0;
1075}
1076
1077/**
1078 * destroy_journal - destroy journal data structures.
1079 * @c: UBIFS file-system description object
1080 *
1081 * This function destroys journal data structures including those that may have
1082 * been created by recovery functions.
1083 */
1084static void destroy_journal(struct ubifs_info *c)
1085{
1086        while (!list_empty(&c->unclean_leb_list)) {
1087                struct ubifs_unclean_leb *ucleb;
1088
1089                ucleb = list_entry(c->unclean_leb_list.next,
1090                                   struct ubifs_unclean_leb, list);
1091                list_del(&ucleb->list);
1092                kfree(ucleb);
1093        }
1094        while (!list_empty(&c->old_buds)) {
1095                struct ubifs_bud *bud;
1096
1097                bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1098                list_del(&bud->list);
1099                kfree(bud);
1100        }
1101        ubifs_destroy_idx_gc(c);
1102        ubifs_destroy_size_tree(c);
1103        ubifs_tnc_close(c);
1104        free_buds(c);
1105}
1106
1107/**
1108 * bu_init - initialize bulk-read information.
1109 * @c: UBIFS file-system description object
1110 */
1111static void bu_init(struct ubifs_info *c)
1112{
1113        ubifs_assert(c->bulk_read == 1);
1114
1115        if (c->bu.buf)
1116                return; /* Already initialized */
1117
1118again:
1119        c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1120        if (!c->bu.buf) {
1121                if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1122                        c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1123                        goto again;
1124                }
1125
1126                /* Just disable bulk-read */
1127                ubifs_warn("Cannot allocate %d bytes of memory for bulk-read, "
1128                           "disabling it", c->max_bu_buf_len);
1129                c->mount_opts.bulk_read = 1;
1130                c->bulk_read = 0;
1131                return;
1132        }
1133}
1134
1135/**
1136 * check_free_space - check if there is enough free space to mount.
1137 * @c: UBIFS file-system description object
1138 *
1139 * This function makes sure UBIFS has enough free space to be mounted in
1140 * read/write mode. UBIFS must always have some free space to allow deletions.
1141 */
1142static int check_free_space(struct ubifs_info *c)
1143{
1144        ubifs_assert(c->dark_wm > 0);
1145        if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1146                ubifs_err("insufficient free space to mount in R/W mode");
1147                ubifs_dump_budg(c, &c->bi);
1148                ubifs_dump_lprops(c);
1149                return -ENOSPC;
1150        }
1151        return 0;
1152}
1153
1154/**
1155 * mount_ubifs - mount UBIFS file-system.
1156 * @c: UBIFS file-system description object
1157 *
1158 * This function mounts UBIFS file system. Returns zero in case of success and
1159 * a negative error code in case of failure.
1160 */
1161static int mount_ubifs(struct ubifs_info *c)
1162{
1163        int err;
1164        long long x;
1165        size_t sz;
1166
1167        c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
1168        err = init_constants_early(c);
1169        if (err)
1170                return err;
1171
1172        err = ubifs_debugging_init(c);
1173        if (err)
1174                return err;
1175
1176        err = check_volume_empty(c);
1177        if (err)
1178                goto out_free;
1179
1180        if (c->empty && (c->ro_mount || c->ro_media)) {
1181                /*
1182                 * This UBI volume is empty, and read-only, or the file system
1183                 * is mounted read-only - we cannot format it.
1184                 */
1185                ubifs_err("can't format empty UBI volume: read-only %s",
1186                          c->ro_media ? "UBI volume" : "mount");
1187                err = -EROFS;
1188                goto out_free;
1189        }
1190
1191        if (c->ro_media && !c->ro_mount) {
1192                ubifs_err("cannot mount read-write - read-only media");
1193                err = -EROFS;
1194                goto out_free;
1195        }
1196
1197        /*
1198         * The requirement for the buffer is that it should fit indexing B-tree
1199         * height amount of integers. We assume the height if the TNC tree will
1200         * never exceed 64.
1201         */
1202        err = -ENOMEM;
1203        c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
1204        if (!c->bottom_up_buf)
1205                goto out_free;
1206
1207        c->sbuf = vmalloc(c->leb_size);
1208        if (!c->sbuf)
1209                goto out_free;
1210
1211        if (!c->ro_mount) {
1212                c->ileb_buf = vmalloc(c->leb_size);
1213                if (!c->ileb_buf)
1214                        goto out_free;
1215        }
1216
1217        if (c->bulk_read == 1)
1218                bu_init(c);
1219
1220        if (!c->ro_mount) {
1221                c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
1222                                               GFP_KERNEL);
1223                if (!c->write_reserve_buf)
1224                        goto out_free;
1225        }
1226
1227        c->mounting = 1;
1228
1229        err = ubifs_read_superblock(c);
1230        if (err)
1231                goto out_free;
1232
1233        /*
1234         * Make sure the compressor which is set as default in the superblock
1235         * or overridden by mount options is actually compiled in.
1236         */
1237        if (!ubifs_compr_present(c->default_compr)) {
1238                ubifs_err("'compressor \"%s\" is not compiled in",
1239                          ubifs_compr_name(c->default_compr));
1240                err = -ENOTSUPP;
1241                goto out_free;
1242        }
1243
1244        err = init_constants_sb(c);
1245        if (err)
1246                goto out_free;
1247
1248        sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1249        sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1250        c->cbuf = kmalloc(sz, GFP_NOFS);
1251        if (!c->cbuf) {
1252                err = -ENOMEM;
1253                goto out_free;
1254        }
1255
1256        err = alloc_wbufs(c);
1257        if (err)
1258                goto out_cbuf;
1259
1260        sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1261        if (!c->ro_mount) {
1262                /* Create background thread */
1263                c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1264                if (IS_ERR(c->bgt)) {
1265                        err = PTR_ERR(c->bgt);
1266                        c->bgt = NULL;
1267                        ubifs_err("cannot spawn \"%s\", error %d",
1268                                  c->bgt_name, err);
1269                        goto out_wbufs;
1270                }
1271                wake_up_process(c->bgt);
1272        }
1273
1274        err = ubifs_read_master(c);
1275        if (err)
1276                goto out_master;
1277
1278        init_constants_master(c);
1279
1280        if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1281                ubifs_msg("recovery needed");
1282                c->need_recovery = 1;
1283        }
1284
1285        if (c->need_recovery && !c->ro_mount) {
1286                err = ubifs_recover_inl_heads(c, c->sbuf);
1287                if (err)
1288                        goto out_master;
1289        }
1290
1291        err = ubifs_lpt_init(c, 1, !c->ro_mount);
1292        if (err)
1293                goto out_master;
1294
1295        if (!c->ro_mount && c->space_fixup) {
1296                err = ubifs_fixup_free_space(c);
1297                if (err)
1298                        goto out_lpt;
1299        }
1300
1301        if (!c->ro_mount) {
1302                /*
1303                 * Set the "dirty" flag so that if we reboot uncleanly we
1304                 * will notice this immediately on the next mount.
1305                 */
1306                c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1307                err = ubifs_write_master(c);
1308                if (err)
1309                        goto out_lpt;
1310        }
1311
1312        err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1313        if (err)
1314                goto out_lpt;
1315
1316        err = ubifs_replay_journal(c);
1317        if (err)
1318                goto out_journal;
1319
1320        /* Calculate 'min_idx_lebs' after journal replay */
1321        c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1322
1323        err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1324        if (err)
1325                goto out_orphans;
1326
1327        if (!c->ro_mount) {
1328                int lnum;
1329
1330                err = check_free_space(c);
1331                if (err)
1332                        goto out_orphans;
1333
1334                /* Check for enough log space */
1335                lnum = c->lhead_lnum + 1;
1336                if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1337                        lnum = UBIFS_LOG_LNUM;
1338                if (lnum == c->ltail_lnum) {
1339                        err = ubifs_consolidate_log(c);
1340                        if (err)
1341                                goto out_orphans;
1342                }
1343
1344                if (c->need_recovery) {
1345                        err = ubifs_recover_size(c);
1346                        if (err)
1347                                goto out_orphans;
1348                        err = ubifs_rcvry_gc_commit(c);
1349                        if (err)
1350                                goto out_orphans;
1351                } else {
1352                        err = take_gc_lnum(c);
1353                        if (err)
1354                                goto out_orphans;
1355
1356                        /*
1357                         * GC LEB may contain garbage if there was an unclean
1358                         * reboot, and it should be un-mapped.
1359                         */
1360                        err = ubifs_leb_unmap(c, c->gc_lnum);
1361                        if (err)
1362                                goto out_orphans;
1363                }
1364
1365                err = dbg_check_lprops(c);
1366                if (err)
1367                        goto out_orphans;
1368        } else if (c->need_recovery) {
1369                err = ubifs_recover_size(c);
1370                if (err)
1371                        goto out_orphans;
1372        } else {
1373                /*
1374                 * Even if we mount read-only, we have to set space in GC LEB
1375                 * to proper value because this affects UBIFS free space
1376                 * reporting. We do not want to have a situation when
1377                 * re-mounting from R/O to R/W changes amount of free space.
1378                 */
1379                err = take_gc_lnum(c);
1380                if (err)
1381                        goto out_orphans;
1382        }
1383
1384        spin_lock(&ubifs_infos_lock);
1385        list_add_tail(&c->infos_list, &ubifs_infos);
1386        spin_unlock(&ubifs_infos_lock);
1387
1388        if (c->need_recovery) {
1389                if (c->ro_mount)
1390                        ubifs_msg("recovery deferred");
1391                else {
1392                        c->need_recovery = 0;
1393                        ubifs_msg("recovery completed");
1394                        /*
1395                         * GC LEB has to be empty and taken at this point. But
1396                         * the journal head LEBs may also be accounted as
1397                         * "empty taken" if they are empty.
1398                         */
1399                        ubifs_assert(c->lst.taken_empty_lebs > 0);
1400                }
1401        } else
1402                ubifs_assert(c->lst.taken_empty_lebs > 0);
1403
1404        err = dbg_check_filesystem(c);
1405        if (err)
1406                goto out_infos;
1407
1408        err = dbg_debugfs_init_fs(c);
1409        if (err)
1410                goto out_infos;
1411
1412        c->mounting = 0;
1413
1414        ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"",
1415                  c->vi.ubi_num, c->vi.vol_id, c->vi.name);
1416        if (c->ro_mount)
1417                ubifs_msg("mounted read-only");
1418        x = (long long)c->main_lebs * c->leb_size;
1419        ubifs_msg("file system size:   %lld bytes (%lld KiB, %lld MiB, %d "
1420                  "LEBs)", x, x >> 10, x >> 20, c->main_lebs);
1421        x = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1422        ubifs_msg("journal size:       %lld bytes (%lld KiB, %lld MiB, %d "
1423                  "LEBs)", x, x >> 10, x >> 20, c->log_lebs + c->max_bud_cnt);
1424        ubifs_msg("media format:       w%d/r%d (latest is w%d/r%d)",
1425                  c->fmt_version, c->ro_compat_version,
1426                  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1427        ubifs_msg("default compressor: %s", ubifs_compr_name(c->default_compr));
1428        ubifs_msg("reserved for root:  %llu bytes (%llu KiB)",
1429                c->report_rp_size, c->report_rp_size >> 10);
1430
1431        dbg_msg("compiled on:         " __DATE__ " at " __TIME__);
1432        dbg_msg("min. I/O unit size:  %d bytes", c->min_io_size);
1433        dbg_msg("max. write size:     %d bytes", c->max_write_size);
1434        dbg_msg("LEB size:            %d bytes (%d KiB)",
1435                c->leb_size, c->leb_size >> 10);
1436        dbg_msg("data journal heads:  %d",
1437                c->jhead_cnt - NONDATA_JHEADS_CNT);
1438        dbg_msg("UUID:                %pUB", c->uuid);
1439        dbg_msg("big_lpt              %d", c->big_lpt);
1440        dbg_msg("log LEBs:            %d (%d - %d)",
1441                c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1442        dbg_msg("LPT area LEBs:       %d (%d - %d)",
1443                c->lpt_lebs, c->lpt_first, c->lpt_last);
1444        dbg_msg("orphan area LEBs:    %d (%d - %d)",
1445                c->orph_lebs, c->orph_first, c->orph_last);
1446        dbg_msg("main area LEBs:      %d (%d - %d)",
1447                c->main_lebs, c->main_first, c->leb_cnt - 1);
1448        dbg_msg("index LEBs:          %d", c->lst.idx_lebs);
1449        dbg_msg("total index bytes:   %lld (%lld KiB, %lld MiB)",
1450                c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1451                c->bi.old_idx_sz >> 20);
1452        dbg_msg("key hash type:       %d", c->key_hash_type);
1453        dbg_msg("tree fanout:         %d", c->fanout);
1454        dbg_msg("reserved GC LEB:     %d", c->gc_lnum);
1455        dbg_msg("first main LEB:      %d", c->main_first);
1456        dbg_msg("max. znode size      %d", c->max_znode_sz);
1457        dbg_msg("max. index node size %d", c->max_idx_node_sz);
1458        dbg_msg("node sizes:          data %zu, inode %zu, dentry %zu",
1459                UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1460        dbg_msg("node sizes:          trun %zu, sb %zu, master %zu",
1461                UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1462        dbg_msg("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1463                UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1464        dbg_msg("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1465                UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1466                UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1467        dbg_msg("dead watermark:      %d", c->dead_wm);
1468        dbg_msg("dark watermark:      %d", c->dark_wm);
1469        dbg_msg("LEB overhead:        %d", c->leb_overhead);
1470        x = (long long)c->main_lebs * c->dark_wm;
1471        dbg_msg("max. dark space:     %lld (%lld KiB, %lld MiB)",
1472                x, x >> 10, x >> 20);
1473        dbg_msg("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1474                c->max_bud_bytes, c->max_bud_bytes >> 10,
1475                c->max_bud_bytes >> 20);
1476        dbg_msg("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1477                c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1478                c->bg_bud_bytes >> 20);
1479        dbg_msg("current bud bytes    %lld (%lld KiB, %lld MiB)",
1480                c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1481        dbg_msg("max. seq. number:    %llu", c->max_sqnum);
1482        dbg_msg("commit number:       %llu", c->cmt_no);
1483
1484        return 0;
1485
1486out_infos:
1487        spin_lock(&ubifs_infos_lock);
1488        list_del(&c->infos_list);
1489        spin_unlock(&ubifs_infos_lock);
1490out_orphans:
1491        free_orphans(c);
1492out_journal:
1493        destroy_journal(c);
1494out_lpt:
1495        ubifs_lpt_free(c, 0);
1496out_master:
1497        kfree(c->mst_node);
1498        kfree(c->rcvrd_mst_node);
1499        if (c->bgt)
1500                kthread_stop(c->bgt);
1501out_wbufs:
1502        free_wbufs(c);
1503out_cbuf:
1504        kfree(c->cbuf);
1505out_free:
1506        kfree(c->write_reserve_buf);
1507        kfree(c->bu.buf);
1508        vfree(c->ileb_buf);
1509        vfree(c->sbuf);
1510        kfree(c->bottom_up_buf);
1511        ubifs_debugging_exit(c);
1512        return err;
1513}
1514
1515/**
1516 * ubifs_umount - un-mount UBIFS file-system.
1517 * @c: UBIFS file-system description object
1518 *
1519 * Note, this function is called to free allocated resourced when un-mounting,
1520 * as well as free resources when an error occurred while we were half way
1521 * through mounting (error path cleanup function). So it has to make sure the
1522 * resource was actually allocated before freeing it.
1523 */
1524static void ubifs_umount(struct ubifs_info *c)
1525{
1526        dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1527                c->vi.vol_id);
1528
1529        dbg_debugfs_exit_fs(c);
1530        spin_lock(&ubifs_infos_lock);
1531        list_del(&c->infos_list);
1532        spin_unlock(&ubifs_infos_lock);
1533
1534        if (c->bgt)
1535                kthread_stop(c->bgt);
1536
1537        destroy_journal(c);
1538        free_wbufs(c);
1539        free_orphans(c);
1540        ubifs_lpt_free(c, 0);
1541
1542        kfree(c->cbuf);
1543        kfree(c->rcvrd_mst_node);
1544        kfree(c->mst_node);
1545        kfree(c->write_reserve_buf);
1546        kfree(c->bu.buf);
1547        vfree(c->ileb_buf);
1548        vfree(c->sbuf);
1549        kfree(c->bottom_up_buf);
1550        ubifs_debugging_exit(c);
1551}
1552
1553/**
1554 * ubifs_remount_rw - re-mount in read-write mode.
1555 * @c: UBIFS file-system description object
1556 *
1557 * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1558 * mode. This function allocates the needed resources and re-mounts UBIFS in
1559 * read-write mode.
1560 */
1561static int ubifs_remount_rw(struct ubifs_info *c)
1562{
1563        int err, lnum;
1564
1565        if (c->rw_incompat) {
1566                ubifs_err("the file-system is not R/W-compatible");
1567                ubifs_msg("on-flash format version is w%d/r%d, but software "
1568                          "only supports up to version w%d/r%d", c->fmt_version,
1569                          c->ro_compat_version, UBIFS_FORMAT_VERSION,
1570                          UBIFS_RO_COMPAT_VERSION);
1571                return -EROFS;
1572        }
1573
1574        mutex_lock(&c->umount_mutex);
1575        dbg_save_space_info(c);
1576        c->remounting_rw = 1;
1577        c->ro_mount = 0;
1578
1579        err = check_free_space(c);
1580        if (err)
1581                goto out;
1582
1583        if (c->old_leb_cnt != c->leb_cnt) {
1584                struct ubifs_sb_node *sup;
1585
1586                sup = ubifs_read_sb_node(c);
1587                if (IS_ERR(sup)) {
1588                        err = PTR_ERR(sup);
1589                        goto out;
1590                }
1591                sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1592                err = ubifs_write_sb_node(c, sup);
1593                kfree(sup);
1594                if (err)
1595                        goto out;
1596        }
1597
1598        if (c->need_recovery) {
1599                ubifs_msg("completing deferred recovery");
1600                err = ubifs_write_rcvrd_mst_node(c);
1601                if (err)
1602                        goto out;
1603                err = ubifs_recover_size(c);
1604                if (err)
1605                        goto out;
1606                err = ubifs_clean_lebs(c, c->sbuf);
1607                if (err)
1608                        goto out;
1609                err = ubifs_recover_inl_heads(c, c->sbuf);
1610                if (err)
1611                        goto out;
1612        } else {
1613                /* A readonly mount is not allowed to have orphans */
1614                ubifs_assert(c->tot_orphans == 0);
1615                err = ubifs_clear_orphans(c);
1616                if (err)
1617                        goto out;
1618        }
1619
1620        if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1621                c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1622                err = ubifs_write_master(c);
1623                if (err)
1624                        goto out;
1625        }
1626
1627        c->ileb_buf = vmalloc(c->leb_size);
1628        if (!c->ileb_buf) {
1629                err = -ENOMEM;
1630                goto out;
1631        }
1632
1633        c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
1634        if (!c->write_reserve_buf)
1635                goto out;
1636
1637        err = ubifs_lpt_init(c, 0, 1);
1638        if (err)
1639                goto out;
1640
1641        /* Create background thread */
1642        c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1643        if (IS_ERR(c->bgt)) {
1644                err = PTR_ERR(c->bgt);
1645                c->bgt = NULL;
1646                ubifs_err("cannot spawn \"%s\", error %d",
1647                          c->bgt_name, err);
1648                goto out;
1649        }
1650        wake_up_process(c->bgt);
1651
1652        c->orph_buf = vmalloc(c->leb_size);
1653        if (!c->orph_buf) {
1654                err = -ENOMEM;
1655                goto out;
1656        }
1657
1658        /* Check for enough log space */
1659        lnum = c->lhead_lnum + 1;
1660        if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1661                lnum = UBIFS_LOG_LNUM;
1662        if (lnum == c->ltail_lnum) {
1663                err = ubifs_consolidate_log(c);
1664                if (err)
1665                        goto out;
1666        }
1667
1668        if (c->need_recovery)
1669                err = ubifs_rcvry_gc_commit(c);
1670        else
1671                err = ubifs_leb_unmap(c, c->gc_lnum);
1672        if (err)
1673                goto out;
1674
1675        dbg_gen("re-mounted read-write");
1676        c->remounting_rw = 0;
1677
1678        if (c->need_recovery) {
1679                c->need_recovery = 0;
1680                ubifs_msg("deferred recovery completed");
1681        } else {
1682                /*
1683                 * Do not run the debugging space check if the were doing
1684                 * recovery, because when we saved the information we had the
1685                 * file-system in a state where the TNC and lprops has been
1686                 * modified in memory, but all the I/O operations (including a
1687                 * commit) were deferred. So the file-system was in
1688                 * "non-committed" state. Now the file-system is in committed
1689                 * state, and of course the amount of free space will change
1690                 * because, for example, the old index size was imprecise.
1691                 */
1692                err = dbg_check_space_info(c);
1693        }
1694
1695        if (c->space_fixup) {
1696                err = ubifs_fixup_free_space(c);
1697                if (err)
1698                        goto out;
1699        }
1700
1701        mutex_unlock(&c->umount_mutex);
1702        return err;
1703
1704out:
1705        c->ro_mount = 1;
1706        vfree(c->orph_buf);
1707        c->orph_buf = NULL;
1708        if (c->bgt) {
1709                kthread_stop(c->bgt);
1710                c->bgt = NULL;
1711        }
1712        free_wbufs(c);
1713        kfree(c->write_reserve_buf);
1714        c->write_reserve_buf = NULL;
1715        vfree(c->ileb_buf);
1716        c->ileb_buf = NULL;
1717        ubifs_lpt_free(c, 1);
1718        c->remounting_rw = 0;
1719        mutex_unlock(&c->umount_mutex);
1720        return err;
1721}
1722
1723/**
1724 * ubifs_remount_ro - re-mount in read-only mode.
1725 * @c: UBIFS file-system description object
1726 *
1727 * We assume VFS has stopped writing. Possibly the background thread could be
1728 * running a commit, however kthread_stop will wait in that case.
1729 */
1730static void ubifs_remount_ro(struct ubifs_info *c)
1731{
1732        int i, err;
1733
1734        ubifs_assert(!c->need_recovery);
1735        ubifs_assert(!c->ro_mount);
1736
1737        mutex_lock(&c->umount_mutex);
1738        if (c->bgt) {
1739                kthread_stop(c->bgt);
1740                c->bgt = NULL;
1741        }
1742
1743        dbg_save_space_info(c);
1744
1745        for (i = 0; i < c->jhead_cnt; i++)
1746                ubifs_wbuf_sync(&c->jheads[i].wbuf);
1747
1748        c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1749        c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1750        c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1751        err = ubifs_write_master(c);
1752        if (err)
1753                ubifs_ro_mode(c, err);
1754
1755        vfree(c->orph_buf);
1756        c->orph_buf = NULL;
1757        kfree(c->write_reserve_buf);
1758        c->write_reserve_buf = NULL;
1759        vfree(c->ileb_buf);
1760        c->ileb_buf = NULL;
1761        ubifs_lpt_free(c, 1);
1762        c->ro_mount = 1;
1763        err = dbg_check_space_info(c);
1764        if (err)
1765                ubifs_ro_mode(c, err);
1766        mutex_unlock(&c->umount_mutex);
1767}
1768
1769static void ubifs_put_super(struct super_block *sb)
1770{
1771        int i;
1772        struct ubifs_info *c = sb->s_fs_info;
1773
1774        ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
1775                  c->vi.vol_id);
1776
1777        /*
1778         * The following asserts are only valid if there has not been a failure
1779         * of the media. For example, there will be dirty inodes if we failed
1780         * to write them back because of I/O errors.
1781         */
1782        if (!c->ro_error) {
1783                ubifs_assert(c->bi.idx_growth == 0);
1784                ubifs_assert(c->bi.dd_growth == 0);
1785                ubifs_assert(c->bi.data_growth == 0);
1786        }
1787
1788        /*
1789         * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1790         * and file system un-mount. Namely, it prevents the shrinker from
1791         * picking this superblock for shrinking - it will be just skipped if
1792         * the mutex is locked.
1793         */
1794        mutex_lock(&c->umount_mutex);
1795        if (!c->ro_mount) {
1796                /*
1797                 * First of all kill the background thread to make sure it does
1798                 * not interfere with un-mounting and freeing resources.
1799                 */
1800                if (c->bgt) {
1801                        kthread_stop(c->bgt);
1802                        c->bgt = NULL;
1803                }
1804
1805                /*
1806                 * On fatal errors c->ro_error is set to 1, in which case we do
1807                 * not write the master node.
1808                 */
1809                if (!c->ro_error) {
1810                        int err;
1811
1812                        /* Synchronize write-buffers */
1813                        for (i = 0; i < c->jhead_cnt; i++)
1814                                ubifs_wbuf_sync(&c->jheads[i].wbuf);
1815
1816                        /*
1817                         * We are being cleanly unmounted which means the
1818                         * orphans were killed - indicate this in the master
1819                         * node. Also save the reserved GC LEB number.
1820                         */
1821                        c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1822                        c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1823                        c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1824                        err = ubifs_write_master(c);
1825                        if (err)
1826                                /*
1827                                 * Recovery will attempt to fix the master area
1828                                 * next mount, so we just print a message and
1829                                 * continue to unmount normally.
1830                                 */
1831                                ubifs_err("failed to write master node, "
1832                                          "error %d", err);
1833                } else {
1834                        for (i = 0; i < c->jhead_cnt; i++)
1835                                /* Make sure write-buffer timers are canceled */
1836                                hrtimer_cancel(&c->jheads[i].wbuf.timer);
1837                }
1838        }
1839
1840        ubifs_umount(c);
1841        bdi_destroy(&c->bdi);
1842        ubi_close_volume(c->ubi);
1843        mutex_unlock(&c->umount_mutex);
1844}
1845
1846static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1847{
1848        int err;
1849        struct ubifs_info *c = sb->s_fs_info;
1850
1851        dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1852
1853        err = ubifs_parse_options(c, data, 1);
1854        if (err) {
1855                ubifs_err("invalid or unknown remount parameter");
1856                return err;
1857        }
1858
1859        if (c->ro_mount && !(*flags & MS_RDONLY)) {
1860                if (c->ro_error) {
1861                        ubifs_msg("cannot re-mount R/W due to prior errors");
1862                        return -EROFS;
1863                }
1864                if (c->ro_media) {
1865                        ubifs_msg("cannot re-mount R/W - UBI volume is R/O");
1866                        return -EROFS;
1867                }
1868                err = ubifs_remount_rw(c);
1869                if (err)
1870                        return err;
1871        } else if (!c->ro_mount && (*flags & MS_RDONLY)) {
1872                if (c->ro_error) {
1873                        ubifs_msg("cannot re-mount R/O due to prior errors");
1874                        return -EROFS;
1875                }
1876                ubifs_remount_ro(c);
1877        }
1878
1879        if (c->bulk_read == 1)
1880                bu_init(c);
1881        else {
1882                dbg_gen("disable bulk-read");
1883                kfree(c->bu.buf);
1884                c->bu.buf = NULL;
1885        }
1886
1887        ubifs_assert(c->lst.taken_empty_lebs > 0);
1888        return 0;
1889}
1890
1891const struct super_operations ubifs_super_operations = {
1892        .alloc_inode   = ubifs_alloc_inode,
1893        .destroy_inode = ubifs_destroy_inode,
1894        .put_super     = ubifs_put_super,
1895        .write_inode   = ubifs_write_inode,
1896        .evict_inode   = ubifs_evict_inode,
1897        .statfs        = ubifs_statfs,
1898        .dirty_inode   = ubifs_dirty_inode,
1899        .remount_fs    = ubifs_remount_fs,
1900        .show_options  = ubifs_show_options,
1901        .sync_fs       = ubifs_sync_fs,
1902};
1903
1904/**
1905 * open_ubi - parse UBI device name string and open the UBI device.
1906 * @name: UBI volume name
1907 * @mode: UBI volume open mode
1908 *
1909 * The primary method of mounting UBIFS is by specifying the UBI volume
1910 * character device node path. However, UBIFS may also be mounted withoug any
1911 * character device node using one of the following methods:
1912 *
1913 * o ubiX_Y    - mount UBI device number X, volume Y;
1914 * o ubiY      - mount UBI device number 0, volume Y;
1915 * o ubiX:NAME - mount UBI device X, volume with name NAME;
1916 * o ubi:NAME  - mount UBI device 0, volume with name NAME.
1917 *
1918 * Alternative '!' separator may be used instead of ':' (because some shells
1919 * like busybox may interpret ':' as an NFS host name separator). This function
1920 * returns UBI volume description object in case of success and a negative
1921 * error code in case of failure.
1922 */
1923static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1924{
1925        struct ubi_volume_desc *ubi;
1926        int dev, vol;
1927        char *endptr;
1928
1929        /* First, try to open using the device node path method */
1930        ubi = ubi_open_volume_path(name, mode);
1931        if (!IS_ERR(ubi))
1932                return ubi;
1933
1934        /* Try the "nodev" method */
1935        if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1936                return ERR_PTR(-EINVAL);
1937
1938        /* ubi:NAME method */
1939        if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1940                return ubi_open_volume_nm(0, name + 4, mode);
1941
1942        if (!isdigit(name[3]))
1943                return ERR_PTR(-EINVAL);
1944
1945        dev = simple_strtoul(name + 3, &endptr, 0);
1946
1947        /* ubiY method */
1948        if (*endptr == '\0')
1949                return ubi_open_volume(0, dev, mode);
1950
1951        /* ubiX_Y method */
1952        if (*endptr == '_' && isdigit(endptr[1])) {
1953                vol = simple_strtoul(endptr + 1, &endptr, 0);
1954                if (*endptr != '\0')
1955                        return ERR_PTR(-EINVAL);
1956                return ubi_open_volume(dev, vol, mode);
1957        }
1958
1959        /* ubiX:NAME method */
1960        if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1961                return ubi_open_volume_nm(dev, ++endptr, mode);
1962
1963        return ERR_PTR(-EINVAL);
1964}
1965
1966static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1967{
1968        struct ubifs_info *c;
1969
1970        c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1971        if (c) {
1972                spin_lock_init(&c->cnt_lock);
1973                spin_lock_init(&c->cs_lock);
1974                spin_lock_init(&c->buds_lock);
1975                spin_lock_init(&c->space_lock);
1976                spin_lock_init(&c->orphan_lock);
1977                init_rwsem(&c->commit_sem);
1978                mutex_init(&c->lp_mutex);
1979                mutex_init(&c->tnc_mutex);
1980                mutex_init(&c->log_mutex);
1981                mutex_init(&c->mst_mutex);
1982                mutex_init(&c->umount_mutex);
1983                mutex_init(&c->bu_mutex);
1984                mutex_init(&c->write_reserve_mutex);
1985                init_waitqueue_head(&c->cmt_wq);
1986                c->buds = RB_ROOT;
1987                c->old_idx = RB_ROOT;
1988                c->size_tree = RB_ROOT;
1989                c->orph_tree = RB_ROOT;
1990                INIT_LIST_HEAD(&c->infos_list);
1991                INIT_LIST_HEAD(&c->idx_gc);
1992                INIT_LIST_HEAD(&c->replay_list);
1993                INIT_LIST_HEAD(&c->replay_buds);
1994                INIT_LIST_HEAD(&c->uncat_list);
1995                INIT_LIST_HEAD(&c->empty_list);
1996                INIT_LIST_HEAD(&c->freeable_list);
1997                INIT_LIST_HEAD(&c->frdi_idx_list);
1998                INIT_LIST_HEAD(&c->unclean_leb_list);
1999                INIT_LIST_HEAD(&c->old_buds);
2000                INIT_LIST_HEAD(&c->orph_list);
2001                INIT_LIST_HEAD(&c->orph_new);
2002                c->no_chk_data_crc = 1;
2003
2004                c->highest_inum = UBIFS_FIRST_INO;
2005                c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2006
2007                ubi_get_volume_info(ubi, &c->vi);
2008                ubi_get_device_info(c->vi.ubi_num, &c->di);
2009        }
2010        return c;
2011}
2012
2013static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2014{
2015        struct ubifs_info *c = sb->s_fs_info;
2016        struct inode *root;
2017        int err;
2018
2019        c->vfs_sb = sb;
2020        /* Re-open the UBI device in read-write mode */
2021        c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2022        if (IS_ERR(c->ubi)) {
2023                err = PTR_ERR(c->ubi);
2024                goto out;
2025        }
2026
2027        /*
2028         * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2029         * UBIFS, I/O is not deferred, it is done immediately in readpage,
2030         * which means the user would have to wait not just for their own I/O
2031         * but the read-ahead I/O as well i.e. completely pointless.
2032         *
2033         * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
2034         */
2035        c->bdi.name = "ubifs",
2036        c->bdi.capabilities = BDI_CAP_MAP_COPY;
2037        err  = bdi_init(&c->bdi);
2038        if (err)
2039                goto out_close;
2040        err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2041                           c->vi.ubi_num, c->vi.vol_id);
2042        if (err)
2043                goto out_bdi;
2044
2045        err = ubifs_parse_options(c, data, 0);
2046        if (err)
2047                goto out_bdi;
2048
2049        sb->s_bdi = &c->bdi;
2050        sb->s_fs_info = c;
2051        sb->s_magic = UBIFS_SUPER_MAGIC;
2052        sb->s_blocksize = UBIFS_BLOCK_SIZE;
2053        sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2054        sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2055        if (c->max_inode_sz > MAX_LFS_FILESIZE)
2056                sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2057        sb->s_op = &ubifs_super_operations;
2058
2059        mutex_lock(&c->umount_mutex);
2060        err = mount_ubifs(c);
2061        if (err) {
2062                ubifs_assert(err < 0);
2063                goto out_unlock;
2064        }
2065
2066        /* Read the root inode */
2067        root = ubifs_iget(sb, UBIFS_ROOT_INO);
2068        if (IS_ERR(root)) {
2069                err = PTR_ERR(root);
2070                goto out_umount;
2071        }
2072
2073        sb->s_root = d_make_root(root);
2074        if (!sb->s_root)
2075                goto out_umount;
2076
2077        mutex_unlock(&c->umount_mutex);
2078        return 0;
2079
2080out_umount:
2081        ubifs_umount(c);
2082out_unlock:
2083        mutex_unlock(&c->umount_mutex);
2084out_bdi:
2085        bdi_destroy(&c->bdi);
2086out_close:
2087        ubi_close_volume(c->ubi);
2088out:
2089        return err;
2090}
2091
2092static int sb_test(struct super_block *sb, void *data)
2093{
2094        struct ubifs_info *c1 = data;
2095        struct ubifs_info *c = sb->s_fs_info;
2096
2097        return c->vi.cdev == c1->vi.cdev;
2098}
2099
2100static int sb_set(struct super_block *sb, void *data)
2101{
2102        sb->s_fs_info = data;
2103        return set_anon_super(sb, NULL);
2104}
2105
2106static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2107                        const char *name, void *data)
2108{
2109        struct ubi_volume_desc *ubi;
2110        struct ubifs_info *c;
2111        struct super_block *sb;
2112        int err;
2113
2114        dbg_gen("name %s, flags %#x", name, flags);
2115
2116        /*
2117         * Get UBI device number and volume ID. Mount it read-only so far
2118         * because this might be a new mount point, and UBI allows only one
2119         * read-write user at a time.
2120         */
2121        ubi = open_ubi(name, UBI_READONLY);
2122        if (IS_ERR(ubi)) {
2123                ubifs_err("cannot open \"%s\", error %d",
2124                          name, (int)PTR_ERR(ubi));
2125                return ERR_CAST(ubi);
2126        }
2127
2128        c = alloc_ubifs_info(ubi);
2129        if (!c) {
2130                err = -ENOMEM;
2131                goto out_close;
2132        }
2133
2134        dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2135
2136        sb = sget(fs_type, sb_test, sb_set, flags, c);
2137        if (IS_ERR(sb)) {
2138                err = PTR_ERR(sb);
2139                kfree(c);
2140                goto out_close;
2141        }
2142
2143        if (sb->s_root) {
2144                struct ubifs_info *c1 = sb->s_fs_info;
2145                kfree(c);
2146                /* A new mount point for already mounted UBIFS */
2147                dbg_gen("this ubi volume is already mounted");
2148                if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2149                        err = -EBUSY;
2150                        goto out_deact;
2151                }
2152        } else {
2153                err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2154                if (err)
2155                        goto out_deact;
2156                /* We do not support atime */
2157                sb->s_flags |= MS_ACTIVE | MS_NOATIME;
2158        }
2159
2160        /* 'fill_super()' opens ubi again so we must close it here */
2161        ubi_close_volume(ubi);
2162
2163        return dget(sb->s_root);
2164
2165out_deact:
2166        deactivate_locked_super(sb);
2167out_close:
2168        ubi_close_volume(ubi);
2169        return ERR_PTR(err);
2170}
2171
2172static void kill_ubifs_super(struct super_block *s)
2173{
2174        struct ubifs_info *c = s->s_fs_info;
2175        kill_anon_super(s);
2176        kfree(c);
2177}
2178
2179static struct file_system_type ubifs_fs_type = {
2180        .name    = "ubifs",
2181        .owner   = THIS_MODULE,
2182        .mount   = ubifs_mount,
2183        .kill_sb = kill_ubifs_super,
2184};
2185
2186/*
2187 * Inode slab cache constructor.
2188 */
2189static void inode_slab_ctor(void *obj)
2190{
2191        struct ubifs_inode *ui = obj;
2192        inode_init_once(&ui->vfs_inode);
2193}
2194
2195static int __init ubifs_init(void)
2196{
2197        int err;
2198
2199        BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2200
2201        /* Make sure node sizes are 8-byte aligned */
2202        BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2203        BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2204        BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2205        BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2206        BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2207        BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2208        BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2209        BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2210        BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2211        BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2212        BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2213
2214        BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2215        BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2216        BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2217        BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2218        BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2219        BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2220
2221        /* Check min. node size */
2222        BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2223        BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2224        BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2225        BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2226
2227        BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2228        BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2229        BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2230        BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2231
2232        /* Defined node sizes */
2233        BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2234        BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2235        BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2236        BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2237
2238        /*
2239         * We use 2 bit wide bit-fields to store compression type, which should
2240         * be amended if more compressors are added. The bit-fields are:
2241         * @compr_type in 'struct ubifs_inode', @default_compr in
2242         * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2243         */
2244        BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2245
2246        /*
2247         * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
2248         * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2249         */
2250        if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
2251                ubifs_err("VFS page cache size is %u bytes, but UBIFS requires"
2252                          " at least 4096 bytes",
2253                          (unsigned int)PAGE_CACHE_SIZE);
2254                return -EINVAL;
2255        }
2256
2257        ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2258                                sizeof(struct ubifs_inode), 0,
2259                                SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
2260                                &inode_slab_ctor);
2261        if (!ubifs_inode_slab)
2262                return -ENOMEM;
2263
2264        register_shrinker(&ubifs_shrinker_info);
2265
2266        err = ubifs_compressors_init();
2267        if (err)
2268                goto out_shrinker;
2269
2270        err = dbg_debugfs_init();
2271        if (err)
2272                goto out_compr;
2273
2274        err = register_filesystem(&ubifs_fs_type);
2275        if (err) {
2276                ubifs_err("cannot register file system, error %d", err);
2277                goto out_dbg;
2278        }
2279        return 0;
2280
2281out_dbg:
2282        dbg_debugfs_exit();
2283out_compr:
2284        ubifs_compressors_exit();
2285out_shrinker:
2286        unregister_shrinker(&ubifs_shrinker_info);
2287        kmem_cache_destroy(ubifs_inode_slab);
2288        return err;
2289}
2290/* late_initcall to let compressors initialize first */
2291late_initcall(ubifs_init);
2292
2293static void __exit ubifs_exit(void)
2294{
2295        ubifs_assert(list_empty(&ubifs_infos));
2296        ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2297
2298        dbg_debugfs_exit();
2299        ubifs_compressors_exit();
2300        unregister_shrinker(&ubifs_shrinker_info);
2301        kmem_cache_destroy(ubifs_inode_slab);
2302        unregister_filesystem(&ubifs_fs_type);
2303}
2304module_exit(ubifs_exit);
2305
2306MODULE_LICENSE("GPL");
2307MODULE_VERSION(__stringify(UBIFS_VERSION));
2308MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2309MODULE_DESCRIPTION("UBIFS - UBI File System");
2310
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