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 pdflush 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 *
1161 * Note, the function does not de-allocate resources it it fails half way
1162 * through, and the caller has to do this instead.
1163 */
1164static int mount_ubifs(struct ubifs_info *c)
1165{
1166	int err;
1167	long long x;
1168	size_t sz;
1169
1170	c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
 
 
 
1171	err = init_constants_early(c);
1172	if (err)
1173		return err;
1174
1175	err = ubifs_debugging_init(c);
1176	if (err)
1177		return err;
1178
 
 
 
 
1179	err = check_volume_empty(c);
1180	if (err)
1181		goto out_free;
1182
1183	if (c->empty && (c->ro_mount || c->ro_media)) {
1184		/*
1185		 * This UBI volume is empty, and read-only, or the file system
1186		 * is mounted read-only - we cannot format it.
1187		 */
1188		ubifs_err("can't format empty UBI volume: read-only %s",
1189			  c->ro_media ? "UBI volume" : "mount");
1190		err = -EROFS;
1191		goto out_free;
1192	}
1193
1194	if (c->ro_media && !c->ro_mount) {
1195		ubifs_err("cannot mount read-write - read-only media");
1196		err = -EROFS;
1197		goto out_free;
1198	}
1199
1200	/*
1201	 * The requirement for the buffer is that it should fit indexing B-tree
1202	 * height amount of integers. We assume the height if the TNC tree will
1203	 * never exceed 64.
1204	 */
1205	err = -ENOMEM;
1206	c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
 
1207	if (!c->bottom_up_buf)
1208		goto out_free;
1209
1210	c->sbuf = vmalloc(c->leb_size);
1211	if (!c->sbuf)
1212		goto out_free;
1213
1214	if (!c->ro_mount) {
1215		c->ileb_buf = vmalloc(c->leb_size);
1216		if (!c->ileb_buf)
1217			goto out_free;
1218	}
1219
1220	if (c->bulk_read == 1)
1221		bu_init(c);
1222
1223	if (!c->ro_mount) {
1224		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
 
1225					       GFP_KERNEL);
1226		if (!c->write_reserve_buf)
1227			goto out_free;
1228	}
1229
1230	c->mounting = 1;
1231
 
 
 
 
 
 
 
 
 
 
 
 
 
1232	err = ubifs_read_superblock(c);
1233	if (err)
1234		goto out_free;
 
 
1235
1236	/*
1237	 * Make sure the compressor which is set as default in the superblock
1238	 * or overridden by mount options is actually compiled in.
1239	 */
1240	if (!ubifs_compr_present(c->default_compr)) {
1241		ubifs_err("'compressor \"%s\" is not compiled in",
1242			  ubifs_compr_name(c->default_compr));
1243		err = -ENOTSUPP;
1244		goto out_free;
1245	}
1246
1247	err = init_constants_sb(c);
1248	if (err)
1249		goto out_free;
1250
1251	sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1252	sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1253	c->cbuf = kmalloc(sz, GFP_NOFS);
1254	if (!c->cbuf) {
1255		err = -ENOMEM;
1256		goto out_free;
1257	}
1258
1259	err = alloc_wbufs(c);
1260	if (err)
1261		goto out_cbuf;
1262
1263	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1264	if (!c->ro_mount) {
1265		/* Create background thread */
1266		c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1267		if (IS_ERR(c->bgt)) {
1268			err = PTR_ERR(c->bgt);
1269			c->bgt = NULL;
1270			ubifs_err("cannot spawn \"%s\", error %d",
1271				  c->bgt_name, err);
1272			goto out_wbufs;
1273		}
1274		wake_up_process(c->bgt);
1275	}
1276
1277	err = ubifs_read_master(c);
1278	if (err)
1279		goto out_master;
1280
1281	init_constants_master(c);
1282
1283	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1284		ubifs_msg("recovery needed");
1285		c->need_recovery = 1;
1286	}
1287
1288	if (c->need_recovery && !c->ro_mount) {
1289		err = ubifs_recover_inl_heads(c, c->sbuf);
1290		if (err)
1291			goto out_master;
1292	}
1293
1294	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1295	if (err)
1296		goto out_master;
1297
1298	if (!c->ro_mount && c->space_fixup) {
1299		err = ubifs_fixup_free_space(c);
1300		if (err)
1301			goto out_lpt;
1302	}
1303
1304	if (!c->ro_mount) {
1305		/*
1306		 * Set the "dirty" flag so that if we reboot uncleanly we
1307		 * will notice this immediately on the next mount.
1308		 */
1309		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1310		err = ubifs_write_master(c);
1311		if (err)
1312			goto out_lpt;
1313	}
1314
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1315	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1316	if (err)
1317		goto out_lpt;
1318
1319	err = ubifs_replay_journal(c);
1320	if (err)
1321		goto out_journal;
1322
1323	/* Calculate 'min_idx_lebs' after journal replay */
1324	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1325
1326	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1327	if (err)
1328		goto out_orphans;
1329
1330	if (!c->ro_mount) {
1331		int lnum;
1332
1333		err = check_free_space(c);
1334		if (err)
1335			goto out_orphans;
1336
1337		/* Check for enough log space */
1338		lnum = c->lhead_lnum + 1;
1339		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1340			lnum = UBIFS_LOG_LNUM;
1341		if (lnum == c->ltail_lnum) {
1342			err = ubifs_consolidate_log(c);
1343			if (err)
1344				goto out_orphans;
1345		}
1346
1347		if (c->need_recovery) {
1348			err = ubifs_recover_size(c);
1349			if (err)
1350				goto out_orphans;
 
 
 
1351			err = ubifs_rcvry_gc_commit(c);
1352			if (err)
1353				goto out_orphans;
 
 
 
 
 
 
1354		} else {
1355			err = take_gc_lnum(c);
1356			if (err)
1357				goto out_orphans;
1358
1359			/*
1360			 * GC LEB may contain garbage if there was an unclean
1361			 * reboot, and it should be un-mapped.
1362			 */
1363			err = ubifs_leb_unmap(c, c->gc_lnum);
1364			if (err)
1365				goto out_orphans;
1366		}
1367
1368		err = dbg_check_lprops(c);
1369		if (err)
1370			goto out_orphans;
1371	} else if (c->need_recovery) {
1372		err = ubifs_recover_size(c);
1373		if (err)
1374			goto out_orphans;
1375	} else {
1376		/*
1377		 * Even if we mount read-only, we have to set space in GC LEB
1378		 * to proper value because this affects UBIFS free space
1379		 * reporting. We do not want to have a situation when
1380		 * re-mounting from R/O to R/W changes amount of free space.
1381		 */
1382		err = take_gc_lnum(c);
1383		if (err)
1384			goto out_orphans;
1385	}
1386
1387	spin_lock(&ubifs_infos_lock);
1388	list_add_tail(&c->infos_list, &ubifs_infos);
1389	spin_unlock(&ubifs_infos_lock);
1390
1391	if (c->need_recovery) {
1392		if (c->ro_mount)
1393			ubifs_msg("recovery deferred");
1394		else {
1395			c->need_recovery = 0;
1396			ubifs_msg("recovery completed");
1397			/*
1398			 * GC LEB has to be empty and taken at this point. But
1399			 * the journal head LEBs may also be accounted as
1400			 * "empty taken" if they are empty.
1401			 */
1402			ubifs_assert(c->lst.taken_empty_lebs > 0);
1403		}
1404	} else
1405		ubifs_assert(c->lst.taken_empty_lebs > 0);
1406
1407	err = dbg_check_filesystem(c);
1408	if (err)
1409		goto out_infos;
1410
1411	err = dbg_debugfs_init_fs(c);
1412	if (err)
1413		goto out_infos;
1414
1415	c->mounting = 0;
1416
1417	ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"",
1418		  c->vi.ubi_num, c->vi.vol_id, c->vi.name);
1419	if (c->ro_mount)
1420		ubifs_msg("mounted read-only");
1421	x = (long long)c->main_lebs * c->leb_size;
1422	ubifs_msg("file system size:   %lld bytes (%lld KiB, %lld MiB, %d "
1423		  "LEBs)", x, x >> 10, x >> 20, c->main_lebs);
1424	x = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1425	ubifs_msg("journal size:       %lld bytes (%lld KiB, %lld MiB, %d "
1426		  "LEBs)", x, x >> 10, x >> 20, c->log_lebs + c->max_bud_cnt);
1427	ubifs_msg("media format:       w%d/r%d (latest is w%d/r%d)",
 
 
 
 
1428		  c->fmt_version, c->ro_compat_version,
1429		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1430	ubifs_msg("default compressor: %s", ubifs_compr_name(c->default_compr));
1431	ubifs_msg("reserved for root:  %llu bytes (%llu KiB)",
1432		c->report_rp_size, c->report_rp_size >> 10);
1433
1434	dbg_msg("compiled on:         " __DATE__ " at " __TIME__);
1435	dbg_msg("min. I/O unit size:  %d bytes", c->min_io_size);
1436	dbg_msg("max. write size:     %d bytes", c->max_write_size);
1437	dbg_msg("LEB size:            %d bytes (%d KiB)",
1438		c->leb_size, c->leb_size >> 10);
1439	dbg_msg("data journal heads:  %d",
1440		c->jhead_cnt - NONDATA_JHEADS_CNT);
1441	dbg_msg("UUID:                %pUB", c->uuid);
1442	dbg_msg("big_lpt              %d", c->big_lpt);
1443	dbg_msg("log LEBs:            %d (%d - %d)",
1444		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1445	dbg_msg("LPT area LEBs:       %d (%d - %d)",
1446		c->lpt_lebs, c->lpt_first, c->lpt_last);
1447	dbg_msg("orphan area LEBs:    %d (%d - %d)",
1448		c->orph_lebs, c->orph_first, c->orph_last);
1449	dbg_msg("main area LEBs:      %d (%d - %d)",
1450		c->main_lebs, c->main_first, c->leb_cnt - 1);
1451	dbg_msg("index LEBs:          %d", c->lst.idx_lebs);
1452	dbg_msg("total index bytes:   %lld (%lld KiB, %lld MiB)",
1453		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1454		c->bi.old_idx_sz >> 20);
1455	dbg_msg("key hash type:       %d", c->key_hash_type);
1456	dbg_msg("tree fanout:         %d", c->fanout);
1457	dbg_msg("reserved GC LEB:     %d", c->gc_lnum);
1458	dbg_msg("first main LEB:      %d", c->main_first);
1459	dbg_msg("max. znode size      %d", c->max_znode_sz);
1460	dbg_msg("max. index node size %d", c->max_idx_node_sz);
1461	dbg_msg("node sizes:          data %zu, inode %zu, dentry %zu",
1462		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1463	dbg_msg("node sizes:          trun %zu, sb %zu, master %zu",
1464		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1465	dbg_msg("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1466		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1467	dbg_msg("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1468		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1469		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1470	dbg_msg("dead watermark:      %d", c->dead_wm);
1471	dbg_msg("dark watermark:      %d", c->dark_wm);
1472	dbg_msg("LEB overhead:        %d", c->leb_overhead);
1473	x = (long long)c->main_lebs * c->dark_wm;
1474	dbg_msg("max. dark space:     %lld (%lld KiB, %lld MiB)",
1475		x, x >> 10, x >> 20);
1476	dbg_msg("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1477		c->max_bud_bytes, c->max_bud_bytes >> 10,
1478		c->max_bud_bytes >> 20);
1479	dbg_msg("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1480		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1481		c->bg_bud_bytes >> 20);
1482	dbg_msg("current bud bytes    %lld (%lld KiB, %lld MiB)",
1483		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1484	dbg_msg("max. seq. number:    %llu", c->max_sqnum);
1485	dbg_msg("commit number:       %llu", c->cmt_no);
 
 
1486
1487	return 0;
1488
1489out_infos:
1490	spin_lock(&ubifs_infos_lock);
1491	list_del(&c->infos_list);
1492	spin_unlock(&ubifs_infos_lock);
1493out_orphans:
1494	free_orphans(c);
1495out_journal:
1496	destroy_journal(c);
1497out_lpt:
1498	ubifs_lpt_free(c, 0);
1499out_master:
1500	kfree(c->mst_node);
1501	kfree(c->rcvrd_mst_node);
1502	if (c->bgt)
1503		kthread_stop(c->bgt);
1504out_wbufs:
1505	free_wbufs(c);
1506out_cbuf:
1507	kfree(c->cbuf);
 
 
1508out_free:
1509	kfree(c->write_reserve_buf);
1510	kfree(c->bu.buf);
1511	vfree(c->ileb_buf);
1512	vfree(c->sbuf);
1513	kfree(c->bottom_up_buf);
 
 
 
1514	ubifs_debugging_exit(c);
1515	return err;
1516}
1517
1518/**
1519 * ubifs_umount - un-mount UBIFS file-system.
1520 * @c: UBIFS file-system description object
1521 *
1522 * Note, this function is called to free allocated resourced when un-mounting,
1523 * as well as free resources when an error occurred while we were half way
1524 * through mounting (error path cleanup function). So it has to make sure the
1525 * resource was actually allocated before freeing it.
1526 */
1527static void ubifs_umount(struct ubifs_info *c)
1528{
1529	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1530		c->vi.vol_id);
1531
1532	dbg_debugfs_exit_fs(c);
1533	spin_lock(&ubifs_infos_lock);
1534	list_del(&c->infos_list);
1535	spin_unlock(&ubifs_infos_lock);
1536
1537	if (c->bgt)
1538		kthread_stop(c->bgt);
1539
1540	destroy_journal(c);
1541	free_wbufs(c);
1542	free_orphans(c);
1543	ubifs_lpt_free(c, 0);
 
1544
 
1545	kfree(c->cbuf);
1546	kfree(c->rcvrd_mst_node);
1547	kfree(c->mst_node);
1548	kfree(c->write_reserve_buf);
1549	kfree(c->bu.buf);
1550	vfree(c->ileb_buf);
1551	vfree(c->sbuf);
1552	kfree(c->bottom_up_buf);
 
1553	ubifs_debugging_exit(c);
 
1554}
1555
1556/**
1557 * ubifs_remount_rw - re-mount in read-write mode.
1558 * @c: UBIFS file-system description object
1559 *
1560 * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1561 * mode. This function allocates the needed resources and re-mounts UBIFS in
1562 * read-write mode.
1563 */
1564static int ubifs_remount_rw(struct ubifs_info *c)
1565{
1566	int err, lnum;
1567
1568	if (c->rw_incompat) {
1569		ubifs_err("the file-system is not R/W-compatible");
1570		ubifs_msg("on-flash format version is w%d/r%d, but software "
1571			  "only supports up to version w%d/r%d", c->fmt_version,
1572			  c->ro_compat_version, UBIFS_FORMAT_VERSION,
1573			  UBIFS_RO_COMPAT_VERSION);
1574		return -EROFS;
1575	}
1576
1577	mutex_lock(&c->umount_mutex);
1578	dbg_save_space_info(c);
1579	c->remounting_rw = 1;
1580	c->ro_mount = 0;
1581
1582	err = check_free_space(c);
1583	if (err)
1584		goto out;
1585
1586	if (c->old_leb_cnt != c->leb_cnt) {
1587		struct ubifs_sb_node *sup;
1588
1589		sup = ubifs_read_sb_node(c);
1590		if (IS_ERR(sup)) {
1591			err = PTR_ERR(sup);
1592			goto out;
1593		}
1594		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1595		err = ubifs_write_sb_node(c, sup);
1596		kfree(sup);
1597		if (err)
1598			goto out;
1599	}
1600
 
 
 
 
1601	if (c->need_recovery) {
1602		ubifs_msg("completing deferred recovery");
1603		err = ubifs_write_rcvrd_mst_node(c);
1604		if (err)
1605			goto out;
1606		err = ubifs_recover_size(c);
1607		if (err)
1608			goto out;
 
 
1609		err = ubifs_clean_lebs(c, c->sbuf);
1610		if (err)
1611			goto out;
1612		err = ubifs_recover_inl_heads(c, c->sbuf);
1613		if (err)
1614			goto out;
1615	} else {
1616		/* A readonly mount is not allowed to have orphans */
1617		ubifs_assert(c->tot_orphans == 0);
1618		err = ubifs_clear_orphans(c);
1619		if (err)
1620			goto out;
1621	}
1622
1623	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1624		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1625		err = ubifs_write_master(c);
1626		if (err)
1627			goto out;
1628	}
1629
 
 
 
 
 
 
 
 
 
 
1630	c->ileb_buf = vmalloc(c->leb_size);
1631	if (!c->ileb_buf) {
1632		err = -ENOMEM;
1633		goto out;
1634	}
1635
1636	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
1637	if (!c->write_reserve_buf)
 
 
1638		goto out;
 
1639
1640	err = ubifs_lpt_init(c, 0, 1);
1641	if (err)
1642		goto out;
1643
1644	/* Create background thread */
1645	c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1646	if (IS_ERR(c->bgt)) {
1647		err = PTR_ERR(c->bgt);
1648		c->bgt = NULL;
1649		ubifs_err("cannot spawn \"%s\", error %d",
1650			  c->bgt_name, err);
1651		goto out;
1652	}
1653	wake_up_process(c->bgt);
1654
1655	c->orph_buf = vmalloc(c->leb_size);
1656	if (!c->orph_buf) {
1657		err = -ENOMEM;
1658		goto out;
1659	}
1660
1661	/* Check for enough log space */
1662	lnum = c->lhead_lnum + 1;
1663	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1664		lnum = UBIFS_LOG_LNUM;
1665	if (lnum == c->ltail_lnum) {
1666		err = ubifs_consolidate_log(c);
1667		if (err)
1668			goto out;
1669	}
1670
1671	if (c->need_recovery)
1672		err = ubifs_rcvry_gc_commit(c);
1673	else
 
 
 
 
 
 
 
 
1674		err = ubifs_leb_unmap(c, c->gc_lnum);
 
1675	if (err)
1676		goto out;
1677
1678	dbg_gen("re-mounted read-write");
1679	c->remounting_rw = 0;
1680
1681	if (c->need_recovery) {
1682		c->need_recovery = 0;
1683		ubifs_msg("deferred recovery completed");
1684	} else {
1685		/*
1686		 * Do not run the debugging space check if the were doing
1687		 * recovery, because when we saved the information we had the
1688		 * file-system in a state where the TNC and lprops has been
1689		 * modified in memory, but all the I/O operations (including a
1690		 * commit) were deferred. So the file-system was in
1691		 * "non-committed" state. Now the file-system is in committed
1692		 * state, and of course the amount of free space will change
1693		 * because, for example, the old index size was imprecise.
1694		 */
1695		err = dbg_check_space_info(c);
1696	}
1697
1698	if (c->space_fixup) {
1699		err = ubifs_fixup_free_space(c);
1700		if (err)
1701			goto out;
1702	}
1703
1704	mutex_unlock(&c->umount_mutex);
1705	return err;
1706
1707out:
1708	c->ro_mount = 1;
1709	vfree(c->orph_buf);
1710	c->orph_buf = NULL;
1711	if (c->bgt) {
1712		kthread_stop(c->bgt);
1713		c->bgt = NULL;
1714	}
1715	free_wbufs(c);
1716	kfree(c->write_reserve_buf);
1717	c->write_reserve_buf = NULL;
1718	vfree(c->ileb_buf);
1719	c->ileb_buf = NULL;
1720	ubifs_lpt_free(c, 1);
1721	c->remounting_rw = 0;
1722	mutex_unlock(&c->umount_mutex);
1723	return err;
1724}
1725
1726/**
1727 * ubifs_remount_ro - re-mount in read-only mode.
1728 * @c: UBIFS file-system description object
1729 *
1730 * We assume VFS has stopped writing. Possibly the background thread could be
1731 * running a commit, however kthread_stop will wait in that case.
1732 */
1733static void ubifs_remount_ro(struct ubifs_info *c)
1734{
1735	int i, err;
1736
1737	ubifs_assert(!c->need_recovery);
1738	ubifs_assert(!c->ro_mount);
1739
1740	mutex_lock(&c->umount_mutex);
1741	if (c->bgt) {
1742		kthread_stop(c->bgt);
1743		c->bgt = NULL;
1744	}
1745
1746	dbg_save_space_info(c);
1747
1748	for (i = 0; i < c->jhead_cnt; i++)
1749		ubifs_wbuf_sync(&c->jheads[i].wbuf);
 
 
 
1750
1751	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1752	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1753	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1754	err = ubifs_write_master(c);
1755	if (err)
1756		ubifs_ro_mode(c, err);
1757
1758	vfree(c->orph_buf);
1759	c->orph_buf = NULL;
1760	kfree(c->write_reserve_buf);
1761	c->write_reserve_buf = NULL;
1762	vfree(c->ileb_buf);
1763	c->ileb_buf = NULL;
1764	ubifs_lpt_free(c, 1);
1765	c->ro_mount = 1;
1766	err = dbg_check_space_info(c);
1767	if (err)
1768		ubifs_ro_mode(c, err);
1769	mutex_unlock(&c->umount_mutex);
1770}
1771
1772static void ubifs_put_super(struct super_block *sb)
1773{
1774	int i;
1775	struct ubifs_info *c = sb->s_fs_info;
1776
1777	ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
1778		  c->vi.vol_id);
1779
1780	/*
1781	 * The following asserts are only valid if there has not been a failure
1782	 * of the media. For example, there will be dirty inodes if we failed
1783	 * to write them back because of I/O errors.
1784	 */
1785	if (!c->ro_error) {
1786		ubifs_assert(c->bi.idx_growth == 0);
1787		ubifs_assert(c->bi.dd_growth == 0);
1788		ubifs_assert(c->bi.data_growth == 0);
1789	}
1790
1791	/*
1792	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1793	 * and file system un-mount. Namely, it prevents the shrinker from
1794	 * picking this superblock for shrinking - it will be just skipped if
1795	 * the mutex is locked.
1796	 */
1797	mutex_lock(&c->umount_mutex);
1798	if (!c->ro_mount) {
1799		/*
1800		 * First of all kill the background thread to make sure it does
1801		 * not interfere with un-mounting and freeing resources.
1802		 */
1803		if (c->bgt) {
1804			kthread_stop(c->bgt);
1805			c->bgt = NULL;
1806		}
1807
1808		/*
1809		 * On fatal errors c->ro_error is set to 1, in which case we do
1810		 * not write the master node.
1811		 */
1812		if (!c->ro_error) {
1813			int err;
1814
1815			/* Synchronize write-buffers */
1816			for (i = 0; i < c->jhead_cnt; i++)
1817				ubifs_wbuf_sync(&c->jheads[i].wbuf);
 
 
 
1818
1819			/*
1820			 * We are being cleanly unmounted which means the
1821			 * orphans were killed - indicate this in the master
1822			 * node. Also save the reserved GC LEB number.
1823			 */
1824			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1825			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1826			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1827			err = ubifs_write_master(c);
1828			if (err)
1829				/*
1830				 * Recovery will attempt to fix the master area
1831				 * next mount, so we just print a message and
1832				 * continue to unmount normally.
1833				 */
1834				ubifs_err("failed to write master node, "
1835					  "error %d", err);
1836		} else {
1837			for (i = 0; i < c->jhead_cnt; i++)
1838				/* Make sure write-buffer timers are canceled */
1839				hrtimer_cancel(&c->jheads[i].wbuf.timer);
1840		}
1841	}
1842
1843	ubifs_umount(c);
1844	bdi_destroy(&c->bdi);
1845	ubi_close_volume(c->ubi);
1846	mutex_unlock(&c->umount_mutex);
1847}
1848
1849static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1850{
1851	int err;
1852	struct ubifs_info *c = sb->s_fs_info;
1853
 
1854	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1855
1856	err = ubifs_parse_options(c, data, 1);
1857	if (err) {
1858		ubifs_err("invalid or unknown remount parameter");
1859		return err;
1860	}
1861
1862	if (c->ro_mount && !(*flags & MS_RDONLY)) {
1863		if (c->ro_error) {
1864			ubifs_msg("cannot re-mount R/W due to prior errors");
1865			return -EROFS;
1866		}
1867		if (c->ro_media) {
1868			ubifs_msg("cannot re-mount R/W - UBI volume is R/O");
1869			return -EROFS;
1870		}
1871		err = ubifs_remount_rw(c);
1872		if (err)
1873			return err;
1874	} else if (!c->ro_mount && (*flags & MS_RDONLY)) {
1875		if (c->ro_error) {
1876			ubifs_msg("cannot re-mount R/O due to prior errors");
1877			return -EROFS;
1878		}
1879		ubifs_remount_ro(c);
1880	}
1881
1882	if (c->bulk_read == 1)
1883		bu_init(c);
1884	else {
1885		dbg_gen("disable bulk-read");
 
1886		kfree(c->bu.buf);
1887		c->bu.buf = NULL;
 
1888	}
1889
1890	ubifs_assert(c->lst.taken_empty_lebs > 0);
 
 
1891	return 0;
1892}
1893
1894const struct super_operations ubifs_super_operations = {
1895	.alloc_inode   = ubifs_alloc_inode,
1896	.destroy_inode = ubifs_destroy_inode,
1897	.put_super     = ubifs_put_super,
1898	.write_inode   = ubifs_write_inode,
 
1899	.evict_inode   = ubifs_evict_inode,
1900	.statfs        = ubifs_statfs,
1901	.dirty_inode   = ubifs_dirty_inode,
1902	.remount_fs    = ubifs_remount_fs,
1903	.show_options  = ubifs_show_options,
1904	.sync_fs       = ubifs_sync_fs,
1905};
1906
1907/**
1908 * open_ubi - parse UBI device name string and open the UBI device.
1909 * @name: UBI volume name
1910 * @mode: UBI volume open mode
1911 *
1912 * The primary method of mounting UBIFS is by specifying the UBI volume
1913 * character device node path. However, UBIFS may also be mounted withoug any
1914 * character device node using one of the following methods:
1915 *
1916 * o ubiX_Y    - mount UBI device number X, volume Y;
1917 * o ubiY      - mount UBI device number 0, volume Y;
1918 * o ubiX:NAME - mount UBI device X, volume with name NAME;
1919 * o ubi:NAME  - mount UBI device 0, volume with name NAME.
1920 *
1921 * Alternative '!' separator may be used instead of ':' (because some shells
1922 * like busybox may interpret ':' as an NFS host name separator). This function
1923 * returns UBI volume description object in case of success and a negative
1924 * error code in case of failure.
1925 */
1926static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1927{
1928	struct ubi_volume_desc *ubi;
1929	int dev, vol;
1930	char *endptr;
1931
 
 
 
1932	/* First, try to open using the device node path method */
1933	ubi = ubi_open_volume_path(name, mode);
1934	if (!IS_ERR(ubi))
1935		return ubi;
1936
1937	/* Try the "nodev" method */
1938	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1939		return ERR_PTR(-EINVAL);
1940
1941	/* ubi:NAME method */
1942	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1943		return ubi_open_volume_nm(0, name + 4, mode);
1944
1945	if (!isdigit(name[3]))
1946		return ERR_PTR(-EINVAL);
1947
1948	dev = simple_strtoul(name + 3, &endptr, 0);
1949
1950	/* ubiY method */
1951	if (*endptr == '\0')
1952		return ubi_open_volume(0, dev, mode);
1953
1954	/* ubiX_Y method */
1955	if (*endptr == '_' && isdigit(endptr[1])) {
1956		vol = simple_strtoul(endptr + 1, &endptr, 0);
1957		if (*endptr != '\0')
1958			return ERR_PTR(-EINVAL);
1959		return ubi_open_volume(dev, vol, mode);
1960	}
1961
1962	/* ubiX:NAME method */
1963	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1964		return ubi_open_volume_nm(dev, ++endptr, mode);
1965
1966	return ERR_PTR(-EINVAL);
1967}
1968
1969static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1970{
1971	struct ubifs_info *c;
1972
1973	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1974	if (c) {
1975		spin_lock_init(&c->cnt_lock);
1976		spin_lock_init(&c->cs_lock);
1977		spin_lock_init(&c->buds_lock);
1978		spin_lock_init(&c->space_lock);
1979		spin_lock_init(&c->orphan_lock);
1980		init_rwsem(&c->commit_sem);
1981		mutex_init(&c->lp_mutex);
1982		mutex_init(&c->tnc_mutex);
1983		mutex_init(&c->log_mutex);
1984		mutex_init(&c->mst_mutex);
1985		mutex_init(&c->umount_mutex);
1986		mutex_init(&c->bu_mutex);
1987		mutex_init(&c->write_reserve_mutex);
1988		init_waitqueue_head(&c->cmt_wq);
1989		c->buds = RB_ROOT;
1990		c->old_idx = RB_ROOT;
1991		c->size_tree = RB_ROOT;
1992		c->orph_tree = RB_ROOT;
1993		INIT_LIST_HEAD(&c->infos_list);
1994		INIT_LIST_HEAD(&c->idx_gc);
1995		INIT_LIST_HEAD(&c->replay_list);
1996		INIT_LIST_HEAD(&c->replay_buds);
1997		INIT_LIST_HEAD(&c->uncat_list);
1998		INIT_LIST_HEAD(&c->empty_list);
1999		INIT_LIST_HEAD(&c->freeable_list);
2000		INIT_LIST_HEAD(&c->frdi_idx_list);
2001		INIT_LIST_HEAD(&c->unclean_leb_list);
2002		INIT_LIST_HEAD(&c->old_buds);
2003		INIT_LIST_HEAD(&c->orph_list);
2004		INIT_LIST_HEAD(&c->orph_new);
2005		c->no_chk_data_crc = 1;
 
2006
2007		c->highest_inum = UBIFS_FIRST_INO;
2008		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2009
2010		ubi_get_volume_info(ubi, &c->vi);
2011		ubi_get_device_info(c->vi.ubi_num, &c->di);
2012	}
2013	return c;
2014}
2015
2016static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2017{
2018	struct ubifs_info *c = sb->s_fs_info;
2019	struct inode *root;
2020	int err;
2021
2022	c->vfs_sb = sb;
2023	/* Re-open the UBI device in read-write mode */
2024	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2025	if (IS_ERR(c->ubi)) {
2026		err = PTR_ERR(c->ubi);
2027		goto out;
2028	}
2029
 
 
 
 
2030	/*
2031	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2032	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
2033	 * which means the user would have to wait not just for their own I/O
2034	 * but the read-ahead I/O as well i.e. completely pointless.
2035	 *
2036	 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
 
 
2037	 */
2038	c->bdi.name = "ubifs",
2039	c->bdi.capabilities = BDI_CAP_MAP_COPY;
2040	err  = bdi_init(&c->bdi);
2041	if (err)
2042		goto out_close;
2043	err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2044			   c->vi.ubi_num, c->vi.vol_id);
2045	if (err)
2046		goto out_bdi;
2047
2048	err = ubifs_parse_options(c, data, 0);
2049	if (err)
2050		goto out_bdi;
2051
2052	sb->s_bdi = &c->bdi;
2053	sb->s_fs_info = c;
2054	sb->s_magic = UBIFS_SUPER_MAGIC;
2055	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2056	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2057	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2058	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2059		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2060	sb->s_op = &ubifs_super_operations;
 
 
2061
2062	mutex_lock(&c->umount_mutex);
2063	err = mount_ubifs(c);
2064	if (err) {
2065		ubifs_assert(err < 0);
2066		goto out_unlock;
2067	}
2068
2069	/* Read the root inode */
2070	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2071	if (IS_ERR(root)) {
2072		err = PTR_ERR(root);
2073		goto out_umount;
2074	}
2075
2076	sb->s_root = d_make_root(root);
2077	if (!sb->s_root)
 
2078		goto out_umount;
 
 
 
2079
2080	mutex_unlock(&c->umount_mutex);
2081	return 0;
2082
2083out_umount:
2084	ubifs_umount(c);
2085out_unlock:
2086	mutex_unlock(&c->umount_mutex);
2087out_bdi:
2088	bdi_destroy(&c->bdi);
2089out_close:
 
2090	ubi_close_volume(c->ubi);
2091out:
2092	return err;
2093}
2094
2095static int sb_test(struct super_block *sb, void *data)
2096{
2097	struct ubifs_info *c1 = data;
2098	struct ubifs_info *c = sb->s_fs_info;
2099
2100	return c->vi.cdev == c1->vi.cdev;
2101}
2102
2103static int sb_set(struct super_block *sb, void *data)
2104{
2105	sb->s_fs_info = data;
2106	return set_anon_super(sb, NULL);
2107}
2108
2109static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2110			const char *name, void *data)
2111{
2112	struct ubi_volume_desc *ubi;
2113	struct ubifs_info *c;
2114	struct super_block *sb;
2115	int err;
2116
2117	dbg_gen("name %s, flags %#x", name, flags);
2118
2119	/*
2120	 * Get UBI device number and volume ID. Mount it read-only so far
2121	 * because this might be a new mount point, and UBI allows only one
2122	 * read-write user at a time.
2123	 */
2124	ubi = open_ubi(name, UBI_READONLY);
2125	if (IS_ERR(ubi)) {
2126		ubifs_err("cannot open \"%s\", error %d",
2127			  name, (int)PTR_ERR(ubi));
 
2128		return ERR_CAST(ubi);
2129	}
2130
2131	c = alloc_ubifs_info(ubi);
2132	if (!c) {
2133		err = -ENOMEM;
2134		goto out_close;
2135	}
2136
2137	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2138
2139	sb = sget(fs_type, sb_test, sb_set, c);
2140	if (IS_ERR(sb)) {
2141		err = PTR_ERR(sb);
2142		kfree(c);
2143		goto out_close;
2144	}
2145
2146	if (sb->s_root) {
2147		struct ubifs_info *c1 = sb->s_fs_info;
2148		kfree(c);
2149		/* A new mount point for already mounted UBIFS */
2150		dbg_gen("this ubi volume is already mounted");
2151		if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2152			err = -EBUSY;
2153			goto out_deact;
2154		}
2155	} else {
2156		sb->s_flags = flags;
2157		err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2158		if (err)
2159			goto out_deact;
2160		/* We do not support atime */
2161		sb->s_flags |= MS_ACTIVE | MS_NOATIME;
 
 
 
 
2162	}
2163
2164	/* 'fill_super()' opens ubi again so we must close it here */
2165	ubi_close_volume(ubi);
2166
2167	return dget(sb->s_root);
2168
2169out_deact:
2170	deactivate_locked_super(sb);
2171out_close:
2172	ubi_close_volume(ubi);
2173	return ERR_PTR(err);
2174}
2175
2176static void kill_ubifs_super(struct super_block *s)
2177{
2178	struct ubifs_info *c = s->s_fs_info;
2179	kill_anon_super(s);
2180	kfree(c);
2181}
2182
2183static struct file_system_type ubifs_fs_type = {
2184	.name    = "ubifs",
2185	.owner   = THIS_MODULE,
2186	.mount   = ubifs_mount,
2187	.kill_sb = kill_ubifs_super,
2188};
 
2189
2190/*
2191 * Inode slab cache constructor.
2192 */
2193static void inode_slab_ctor(void *obj)
2194{
2195	struct ubifs_inode *ui = obj;
2196	inode_init_once(&ui->vfs_inode);
2197}
2198
2199static int __init ubifs_init(void)
2200{
2201	int err;
2202
2203	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2204
2205	/* Make sure node sizes are 8-byte aligned */
2206	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2207	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2208	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2209	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2210	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2211	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2212	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2213	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2214	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2215	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2216	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2217
2218	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2219	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2220	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2221	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2222	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2223	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2224
2225	/* Check min. node size */
2226	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2227	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2228	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2229	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2230
2231	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2232	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2233	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2234	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2235
2236	/* Defined node sizes */
2237	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2238	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2239	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2240	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2241
2242	/*
2243	 * We use 2 bit wide bit-fields to store compression type, which should
2244	 * be amended if more compressors are added. The bit-fields are:
2245	 * @compr_type in 'struct ubifs_inode', @default_compr in
2246	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2247	 */
2248	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2249
2250	/*
2251	 * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
2252	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2253	 */
2254	if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
2255		ubifs_err("VFS page cache size is %u bytes, but UBIFS requires"
2256			  " at least 4096 bytes",
2257			  (unsigned int)PAGE_CACHE_SIZE);
2258		return -EINVAL;
2259	}
2260
2261	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2262				sizeof(struct ubifs_inode), 0,
2263				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
2264				&inode_slab_ctor);
2265	if (!ubifs_inode_slab)
2266		return -ENOMEM;
2267
2268	register_shrinker(&ubifs_shrinker_info);
 
 
 
 
 
 
 
2269
2270	err = ubifs_compressors_init();
2271	if (err)
2272		goto out_shrinker;
2273
2274	err = dbg_debugfs_init();
 
 
2275	if (err)
2276		goto out_compr;
2277
2278	err = register_filesystem(&ubifs_fs_type);
2279	if (err) {
2280		ubifs_err("cannot register file system, error %d", err);
2281		goto out_dbg;
 
2282	}
2283	return 0;
2284
 
 
2285out_dbg:
2286	dbg_debugfs_exit();
2287out_compr:
2288	ubifs_compressors_exit();
2289out_shrinker:
2290	unregister_shrinker(&ubifs_shrinker_info);
 
2291	kmem_cache_destroy(ubifs_inode_slab);
2292	return err;
2293}
2294/* late_initcall to let compressors initialize first */
2295late_initcall(ubifs_init);
2296
2297static void __exit ubifs_exit(void)
2298{
2299	ubifs_assert(list_empty(&ubifs_infos));
2300	ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2301
2302	dbg_debugfs_exit();
 
2303	ubifs_compressors_exit();
2304	unregister_shrinker(&ubifs_shrinker_info);
 
 
 
 
 
 
2305	kmem_cache_destroy(ubifs_inode_slab);
2306	unregister_filesystem(&ubifs_fs_type);
2307}
2308module_exit(ubifs_exit);
2309
2310MODULE_LICENSE("GPL");
2311MODULE_VERSION(__stringify(UBIFS_VERSION));
2312MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2313MODULE_DESCRIPTION("UBIFS - UBI File System");