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