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	.scan_objects = ubifs_shrink_scan,
  53	.count_objects = ubifs_shrink_count,
  54	.seeks = DEFAULT_SEEKS,
  55};
  56
  57/**
  58 * validate_inode - validate inode.
  59 * @c: UBIFS file-system description object
  60 * @inode: the inode to validate
  61 *
  62 * This is a helper function for 'ubifs_iget()' which validates various fields
  63 * of a newly built inode to make sure they contain sane values and prevent
  64 * possible vulnerabilities. Returns zero if the inode is all right and
  65 * a non-zero error code if not.
  66 */
  67static int validate_inode(struct ubifs_info *c, const struct inode *inode)
  68{
  69	int err;
  70	const struct ubifs_inode *ui = ubifs_inode(inode);
  71
  72	if (inode->i_size > c->max_inode_sz) {
  73		ubifs_err("inode is too large (%lld)",
  74			  (long long)inode->i_size);
  75		return 1;
  76	}
  77
  78	if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
  79		ubifs_err("unknown compression type %d", ui->compr_type);
  80		return 2;
  81	}
  82
  83	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
  84		return 3;
  85
  86	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
  87		return 4;
  88
  89	if (ui->xattr && !S_ISREG(inode->i_mode))
  90		return 5;
  91
  92	if (!ubifs_compr_present(ui->compr_type)) {
  93		ubifs_warn("inode %lu uses '%s' compression, but it was not compiled in",
  94			   inode->i_ino, 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	i_uid_write(inode, le32_to_cpu(ino->uid));
 134	i_gid_write(inode, le32_to_cpu(ino->gid));
 135	inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
 136	inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
 137	inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
 138	inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
 139	inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
 140	inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
 141	inode->i_mode = le32_to_cpu(ino->mode);
 142	inode->i_size = le64_to_cpu(ino->size);
 143
 144	ui->data_len    = le32_to_cpu(ino->data_len);
 145	ui->flags       = le32_to_cpu(ino->flags);
 146	ui->compr_type  = le16_to_cpu(ino->compr_type);
 147	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
 148	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
 149	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
 150	ui->xattr_names = le32_to_cpu(ino->xattr_names);
 151	ui->synced_i_size = ui->ui_size = inode->i_size;
 152
 153	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
 154
 155	err = validate_inode(c, inode);
 156	if (err)
 157		goto out_invalid;
 158
 159	/* Disable read-ahead */
 160	inode->i_mapping->backing_dev_info = &c->bdi;
 161
 162	switch (inode->i_mode & S_IFMT) {
 163	case S_IFREG:
 164		inode->i_mapping->a_ops = &ubifs_file_address_operations;
 165		inode->i_op = &ubifs_file_inode_operations;
 166		inode->i_fop = &ubifs_file_operations;
 167		if (ui->xattr) {
 168			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 169			if (!ui->data) {
 170				err = -ENOMEM;
 171				goto out_ino;
 172			}
 173			memcpy(ui->data, ino->data, ui->data_len);
 174			((char *)ui->data)[ui->data_len] = '\0';
 175		} else if (ui->data_len != 0) {
 176			err = 10;
 177			goto out_invalid;
 178		}
 179		break;
 180	case S_IFDIR:
 181		inode->i_op  = &ubifs_dir_inode_operations;
 182		inode->i_fop = &ubifs_dir_operations;
 183		if (ui->data_len != 0) {
 184			err = 11;
 185			goto out_invalid;
 186		}
 187		break;
 188	case S_IFLNK:
 189		inode->i_op = &ubifs_symlink_inode_operations;
 190		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
 191			err = 12;
 192			goto out_invalid;
 193		}
 194		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 195		if (!ui->data) {
 196			err = -ENOMEM;
 197			goto out_ino;
 198		}
 199		memcpy(ui->data, ino->data, ui->data_len);
 200		((char *)ui->data)[ui->data_len] = '\0';
 201		break;
 202	case S_IFBLK:
 203	case S_IFCHR:
 204	{
 205		dev_t rdev;
 206		union ubifs_dev_desc *dev;
 207
 208		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
 209		if (!ui->data) {
 210			err = -ENOMEM;
 211			goto out_ino;
 212		}
 213
 214		dev = (union ubifs_dev_desc *)ino->data;
 215		if (ui->data_len == sizeof(dev->new))
 216			rdev = new_decode_dev(le32_to_cpu(dev->new));
 217		else if (ui->data_len == sizeof(dev->huge))
 218			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
 219		else {
 220			err = 13;
 221			goto out_invalid;
 222		}
 223		memcpy(ui->data, ino->data, ui->data_len);
 224		inode->i_op = &ubifs_file_inode_operations;
 225		init_special_inode(inode, inode->i_mode, rdev);
 226		break;
 227	}
 228	case S_IFSOCK:
 229	case S_IFIFO:
 230		inode->i_op = &ubifs_file_inode_operations;
 231		init_special_inode(inode, inode->i_mode, 0);
 232		if (ui->data_len != 0) {
 233			err = 14;
 234			goto out_invalid;
 235		}
 236		break;
 237	default:
 238		err = 15;
 239		goto out_invalid;
 240	}
 241
 242	kfree(ino);
 243	ubifs_set_inode_flags(inode);
 244	unlock_new_inode(inode);
 245	return inode;
 246
 247out_invalid:
 248	ubifs_err("inode %lu validation failed, error %d", inode->i_ino, err);
 249	ubifs_dump_node(c, ino);
 250	ubifs_dump_inode(c, inode);
 251	err = -EINVAL;
 252out_ino:
 253	kfree(ino);
 254out:
 255	ubifs_err("failed to read inode %lu, error %d", inode->i_ino, err);
 256	iget_failed(inode);
 257	return ERR_PTR(err);
 258}
 259
 260static struct inode *ubifs_alloc_inode(struct super_block *sb)
 261{
 262	struct ubifs_inode *ui;
 263
 264	ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
 265	if (!ui)
 266		return NULL;
 267
 268	memset((void *)ui + sizeof(struct inode), 0,
 269	       sizeof(struct ubifs_inode) - sizeof(struct inode));
 270	mutex_init(&ui->ui_mutex);
 271	spin_lock_init(&ui->ui_lock);
 272	return &ui->vfs_inode;
 273};
 274
 275static void ubifs_i_callback(struct rcu_head *head)
 276{
 277	struct inode *inode = container_of(head, struct inode, i_rcu);
 278	struct ubifs_inode *ui = ubifs_inode(inode);
 279	kmem_cache_free(ubifs_inode_slab, ui);
 280}
 281
 282static void ubifs_destroy_inode(struct inode *inode)
 283{
 284	struct ubifs_inode *ui = ubifs_inode(inode);
 285
 286	kfree(ui->data);
 287	call_rcu(&inode->i_rcu, ubifs_i_callback);
 288}
 289
 290/*
 291 * Note, Linux write-back code calls this without 'i_mutex'.
 292 */
 293static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
 294{
 295	int err = 0;
 296	struct ubifs_info *c = inode->i_sb->s_fs_info;
 297	struct ubifs_inode *ui = ubifs_inode(inode);
 298
 299	ubifs_assert(!ui->xattr);
 300	if (is_bad_inode(inode))
 301		return 0;
 302
 303	mutex_lock(&ui->ui_mutex);
 304	/*
 305	 * Due to races between write-back forced by budgeting
 306	 * (see 'sync_some_inodes()') and background write-back, the inode may
 307	 * have already been synchronized, do not do this again. This might
 308	 * also happen if it was synchronized in an VFS operation, e.g.
 309	 * 'ubifs_link()'.
 310	 */
 311	if (!ui->dirty) {
 312		mutex_unlock(&ui->ui_mutex);
 313		return 0;
 314	}
 315
 316	/*
 317	 * As an optimization, do not write orphan inodes to the media just
 318	 * because this is not needed.
 319	 */
 320	dbg_gen("inode %lu, mode %#x, nlink %u",
 321		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
 322	if (inode->i_nlink) {
 323		err = ubifs_jnl_write_inode(c, inode);
 324		if (err)
 325			ubifs_err("can't write inode %lu, error %d",
 326				  inode->i_ino, err);
 327		else
 328			err = dbg_check_inode_size(c, inode, ui->ui_size);
 329	}
 330
 331	ui->dirty = 0;
 332	mutex_unlock(&ui->ui_mutex);
 333	ubifs_release_dirty_inode_budget(c, ui);
 334	return err;
 335}
 336
 337static void ubifs_evict_inode(struct inode *inode)
 338{
 339	int err;
 340	struct ubifs_info *c = inode->i_sb->s_fs_info;
 341	struct ubifs_inode *ui = ubifs_inode(inode);
 342
 343	if (ui->xattr)
 344		/*
 345		 * Extended attribute inode deletions are fully handled in
 346		 * 'ubifs_removexattr()'. These inodes are special and have
 347		 * limited usage, so there is nothing to do here.
 348		 */
 349		goto out;
 350
 351	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
 352	ubifs_assert(!atomic_read(&inode->i_count));
 353
 354	truncate_inode_pages_final(&inode->i_data);
 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 ubifs_bud *bud, *n;
 877
 878	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
 879		kfree(bud);
 880}
 881
 882/**
 883 * check_volume_empty - check if the UBI volume is empty.
 884 * @c: UBIFS file-system description object
 885 *
 886 * This function checks if the UBIFS volume is empty by looking if its LEBs are
 887 * mapped or not. The result of checking is stored in the @c->empty variable.
 888 * Returns zero in case of success and a negative error code in case of
 889 * failure.
 890 */
 891static int check_volume_empty(struct ubifs_info *c)
 892{
 893	int lnum, err;
 894
 895	c->empty = 1;
 896	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
 897		err = ubifs_is_mapped(c, lnum);
 898		if (unlikely(err < 0))
 899			return err;
 900		if (err == 1) {
 901			c->empty = 0;
 902			break;
 903		}
 904
 905		cond_resched();
 906	}
 907
 908	return 0;
 909}
 910
 911/*
 912 * UBIFS mount options.
 913 *
 914 * Opt_fast_unmount: do not run a journal commit before un-mounting
 915 * Opt_norm_unmount: run a journal commit before un-mounting
 916 * Opt_bulk_read: enable bulk-reads
 917 * Opt_no_bulk_read: disable bulk-reads
 918 * Opt_chk_data_crc: check CRCs when reading data nodes
 919 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
 920 * Opt_override_compr: override default compressor
 921 * Opt_err: just end of array marker
 922 */
 923enum {
 924	Opt_fast_unmount,
 925	Opt_norm_unmount,
 926	Opt_bulk_read,
 927	Opt_no_bulk_read,
 928	Opt_chk_data_crc,
 929	Opt_no_chk_data_crc,
 930	Opt_override_compr,
 
 931	Opt_err,
 932};
 933
 934static const match_table_t tokens = {
 935	{Opt_fast_unmount, "fast_unmount"},
 936	{Opt_norm_unmount, "norm_unmount"},
 937	{Opt_bulk_read, "bulk_read"},
 938	{Opt_no_bulk_read, "no_bulk_read"},
 939	{Opt_chk_data_crc, "chk_data_crc"},
 940	{Opt_no_chk_data_crc, "no_chk_data_crc"},
 941	{Opt_override_compr, "compr=%s"},
 
 
 942	{Opt_err, NULL},
 943};
 944
 945/**
 946 * parse_standard_option - parse a standard mount option.
 947 * @option: the option to parse
 948 *
 949 * Normally, standard mount options like "sync" are passed to file-systems as
 950 * flags. However, when a "rootflags=" kernel boot parameter is used, they may
 951 * be present in the options string. This function tries to deal with this
 952 * situation and parse standard options. Returns 0 if the option was not
 953 * recognized, and the corresponding integer flag if it was.
 954 *
 955 * UBIFS is only interested in the "sync" option, so do not check for anything
 956 * else.
 957 */
 958static int parse_standard_option(const char *option)
 959{
 960	ubifs_msg("parse %s", option);
 
 961	if (!strcmp(option, "sync"))
 962		return MS_SYNCHRONOUS;
 963	return 0;
 964}
 965
 966/**
 967 * ubifs_parse_options - parse mount parameters.
 968 * @c: UBIFS file-system description object
 969 * @options: parameters to parse
 970 * @is_remount: non-zero if this is FS re-mount
 971 *
 972 * This function parses UBIFS mount options and returns zero in case success
 973 * and a negative error code in case of failure.
 974 */
 975static int ubifs_parse_options(struct ubifs_info *c, char *options,
 976			       int is_remount)
 977{
 978	char *p;
 979	substring_t args[MAX_OPT_ARGS];
 980
 981	if (!options)
 982		return 0;
 983
 984	while ((p = strsep(&options, ","))) {
 985		int token;
 986
 987		if (!*p)
 988			continue;
 989
 990		token = match_token(p, tokens, args);
 991		switch (token) {
 992		/*
 993		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
 994		 * We accept them in order to be backward-compatible. But this
 995		 * should be removed at some point.
 996		 */
 997		case Opt_fast_unmount:
 998			c->mount_opts.unmount_mode = 2;
 999			break;
1000		case Opt_norm_unmount:
1001			c->mount_opts.unmount_mode = 1;
1002			break;
1003		case Opt_bulk_read:
1004			c->mount_opts.bulk_read = 2;
1005			c->bulk_read = 1;
1006			break;
1007		case Opt_no_bulk_read:
1008			c->mount_opts.bulk_read = 1;
1009			c->bulk_read = 0;
1010			break;
1011		case Opt_chk_data_crc:
1012			c->mount_opts.chk_data_crc = 2;
1013			c->no_chk_data_crc = 0;
1014			break;
1015		case Opt_no_chk_data_crc:
1016			c->mount_opts.chk_data_crc = 1;
1017			c->no_chk_data_crc = 1;
1018			break;
1019		case Opt_override_compr:
1020		{
1021			char *name = match_strdup(&args[0]);
1022
1023			if (!name)
1024				return -ENOMEM;
1025			if (!strcmp(name, "none"))
1026				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1027			else if (!strcmp(name, "lzo"))
1028				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1029			else if (!strcmp(name, "zlib"))
1030				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1031			else {
1032				ubifs_err("unknown compressor \"%s\"", name);
1033				kfree(name);
1034				return -EINVAL;
1035			}
1036			kfree(name);
1037			c->mount_opts.override_compr = 1;
1038			c->default_compr = c->mount_opts.compr_type;
1039			break;
1040		}
 
 
1041		default:
1042		{
1043			unsigned long flag;
1044			struct super_block *sb = c->vfs_sb;
1045
1046			flag = parse_standard_option(p);
1047			if (!flag) {
1048				ubifs_err("unrecognized mount option \"%s\" or missing value",
1049					  p);
1050				return -EINVAL;
1051			}
1052			sb->s_flags |= flag;
1053			break;
1054		}
1055		}
1056	}
1057
1058	return 0;
1059}
1060
1061/**
1062 * destroy_journal - destroy journal data structures.
1063 * @c: UBIFS file-system description object
1064 *
1065 * This function destroys journal data structures including those that may have
1066 * been created by recovery functions.
1067 */
1068static void destroy_journal(struct ubifs_info *c)
1069{
1070	while (!list_empty(&c->unclean_leb_list)) {
1071		struct ubifs_unclean_leb *ucleb;
1072
1073		ucleb = list_entry(c->unclean_leb_list.next,
1074				   struct ubifs_unclean_leb, list);
1075		list_del(&ucleb->list);
1076		kfree(ucleb);
1077	}
1078	while (!list_empty(&c->old_buds)) {
1079		struct ubifs_bud *bud;
1080
1081		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1082		list_del(&bud->list);
1083		kfree(bud);
1084	}
1085	ubifs_destroy_idx_gc(c);
1086	ubifs_destroy_size_tree(c);
1087	ubifs_tnc_close(c);
1088	free_buds(c);
1089}
1090
1091/**
1092 * bu_init - initialize bulk-read information.
1093 * @c: UBIFS file-system description object
1094 */
1095static void bu_init(struct ubifs_info *c)
1096{
1097	ubifs_assert(c->bulk_read == 1);
1098
1099	if (c->bu.buf)
1100		return; /* Already initialized */
1101
1102again:
1103	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1104	if (!c->bu.buf) {
1105		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1106			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1107			goto again;
1108		}
1109
1110		/* Just disable bulk-read */
1111		ubifs_warn("cannot allocate %d bytes of memory for bulk-read, disabling it",
1112			   c->max_bu_buf_len);
1113		c->mount_opts.bulk_read = 1;
1114		c->bulk_read = 0;
1115		return;
1116	}
1117}
1118
1119/**
1120 * check_free_space - check if there is enough free space to mount.
1121 * @c: UBIFS file-system description object
1122 *
1123 * This function makes sure UBIFS has enough free space to be mounted in
1124 * read/write mode. UBIFS must always have some free space to allow deletions.
1125 */
1126static int check_free_space(struct ubifs_info *c)
1127{
1128	ubifs_assert(c->dark_wm > 0);
1129	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1130		ubifs_err("insufficient free space to mount in R/W mode");
1131		ubifs_dump_budg(c, &c->bi);
1132		ubifs_dump_lprops(c);
1133		return -ENOSPC;
1134	}
1135	return 0;
1136}
1137
1138/**
1139 * mount_ubifs - mount UBIFS file-system.
1140 * @c: UBIFS file-system description object
1141 *
1142 * This function mounts UBIFS file system. Returns zero in case of success and
1143 * a negative error code in case of failure.
1144 */
1145static int mount_ubifs(struct ubifs_info *c)
1146{
1147	int err;
1148	long long x, y;
1149	size_t sz;
1150
1151	c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
 
 
 
1152	err = init_constants_early(c);
1153	if (err)
1154		return err;
1155
1156	err = ubifs_debugging_init(c);
1157	if (err)
1158		return err;
1159
1160	err = check_volume_empty(c);
1161	if (err)
1162		goto out_free;
1163
1164	if (c->empty && (c->ro_mount || c->ro_media)) {
1165		/*
1166		 * This UBI volume is empty, and read-only, or the file system
1167		 * is mounted read-only - we cannot format it.
1168		 */
1169		ubifs_err("can't format empty UBI volume: read-only %s",
1170			  c->ro_media ? "UBI volume" : "mount");
1171		err = -EROFS;
1172		goto out_free;
1173	}
1174
1175	if (c->ro_media && !c->ro_mount) {
1176		ubifs_err("cannot mount read-write - read-only media");
1177		err = -EROFS;
1178		goto out_free;
1179	}
1180
1181	/*
1182	 * The requirement for the buffer is that it should fit indexing B-tree
1183	 * height amount of integers. We assume the height if the TNC tree will
1184	 * never exceed 64.
1185	 */
1186	err = -ENOMEM;
1187	c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
1188	if (!c->bottom_up_buf)
1189		goto out_free;
1190
1191	c->sbuf = vmalloc(c->leb_size);
1192	if (!c->sbuf)
1193		goto out_free;
1194
1195	if (!c->ro_mount) {
1196		c->ileb_buf = vmalloc(c->leb_size);
1197		if (!c->ileb_buf)
1198			goto out_free;
1199	}
1200
1201	if (c->bulk_read == 1)
1202		bu_init(c);
1203
1204	if (!c->ro_mount) {
1205		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
 
1206					       GFP_KERNEL);
1207		if (!c->write_reserve_buf)
1208			goto out_free;
1209	}
1210
1211	c->mounting = 1;
1212
1213	err = ubifs_read_superblock(c);
1214	if (err)
1215		goto out_free;
1216
 
 
1217	/*
1218	 * Make sure the compressor which is set as default in the superblock
1219	 * or overridden by mount options is actually compiled in.
1220	 */
1221	if (!ubifs_compr_present(c->default_compr)) {
1222		ubifs_err("'compressor \"%s\" is not compiled in",
1223			  ubifs_compr_name(c->default_compr));
1224		err = -ENOTSUPP;
1225		goto out_free;
1226	}
1227
1228	err = init_constants_sb(c);
1229	if (err)
1230		goto out_free;
1231
1232	sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1233	sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1234	c->cbuf = kmalloc(sz, GFP_NOFS);
1235	if (!c->cbuf) {
1236		err = -ENOMEM;
1237		goto out_free;
1238	}
1239
1240	err = alloc_wbufs(c);
1241	if (err)
1242		goto out_cbuf;
1243
1244	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1245	if (!c->ro_mount) {
1246		/* Create background thread */
1247		c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1248		if (IS_ERR(c->bgt)) {
1249			err = PTR_ERR(c->bgt);
1250			c->bgt = NULL;
1251			ubifs_err("cannot spawn \"%s\", error %d",
1252				  c->bgt_name, err);
1253			goto out_wbufs;
1254		}
1255		wake_up_process(c->bgt);
1256	}
1257
1258	err = ubifs_read_master(c);
1259	if (err)
1260		goto out_master;
1261
1262	init_constants_master(c);
1263
1264	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1265		ubifs_msg("recovery needed");
1266		c->need_recovery = 1;
1267	}
1268
1269	if (c->need_recovery && !c->ro_mount) {
1270		err = ubifs_recover_inl_heads(c, c->sbuf);
1271		if (err)
1272			goto out_master;
1273	}
1274
1275	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1276	if (err)
1277		goto out_master;
1278
1279	if (!c->ro_mount && c->space_fixup) {
1280		err = ubifs_fixup_free_space(c);
1281		if (err)
1282			goto out_lpt;
1283	}
1284
1285	if (!c->ro_mount) {
1286		/*
1287		 * Set the "dirty" flag so that if we reboot uncleanly we
1288		 * will notice this immediately on the next mount.
1289		 */
1290		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1291		err = ubifs_write_master(c);
1292		if (err)
1293			goto out_lpt;
1294	}
1295
1296	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1297	if (err)
1298		goto out_lpt;
1299
1300	err = ubifs_replay_journal(c);
1301	if (err)
1302		goto out_journal;
1303
1304	/* Calculate 'min_idx_lebs' after journal replay */
1305	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1306
1307	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1308	if (err)
1309		goto out_orphans;
1310
1311	if (!c->ro_mount) {
1312		int lnum;
1313
1314		err = check_free_space(c);
1315		if (err)
1316			goto out_orphans;
1317
1318		/* Check for enough log space */
1319		lnum = c->lhead_lnum + 1;
1320		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1321			lnum = UBIFS_LOG_LNUM;
1322		if (lnum == c->ltail_lnum) {
1323			err = ubifs_consolidate_log(c);
1324			if (err)
1325				goto out_orphans;
1326		}
1327
1328		if (c->need_recovery) {
1329			err = ubifs_recover_size(c);
1330			if (err)
1331				goto out_orphans;
1332			err = ubifs_rcvry_gc_commit(c);
1333			if (err)
1334				goto out_orphans;
1335		} else {
1336			err = take_gc_lnum(c);
1337			if (err)
1338				goto out_orphans;
1339
1340			/*
1341			 * GC LEB may contain garbage if there was an unclean
1342			 * reboot, and it should be un-mapped.
1343			 */
1344			err = ubifs_leb_unmap(c, c->gc_lnum);
1345			if (err)
1346				goto out_orphans;
1347		}
1348
1349		err = dbg_check_lprops(c);
1350		if (err)
1351			goto out_orphans;
1352	} else if (c->need_recovery) {
1353		err = ubifs_recover_size(c);
1354		if (err)
1355			goto out_orphans;
1356	} else {
1357		/*
1358		 * Even if we mount read-only, we have to set space in GC LEB
1359		 * to proper value because this affects UBIFS free space
1360		 * reporting. We do not want to have a situation when
1361		 * re-mounting from R/O to R/W changes amount of free space.
1362		 */
1363		err = take_gc_lnum(c);
1364		if (err)
1365			goto out_orphans;
1366	}
1367
1368	spin_lock(&ubifs_infos_lock);
1369	list_add_tail(&c->infos_list, &ubifs_infos);
1370	spin_unlock(&ubifs_infos_lock);
1371
1372	if (c->need_recovery) {
1373		if (c->ro_mount)
1374			ubifs_msg("recovery deferred");
1375		else {
1376			c->need_recovery = 0;
1377			ubifs_msg("recovery completed");
1378			/*
1379			 * GC LEB has to be empty and taken at this point. But
1380			 * the journal head LEBs may also be accounted as
1381			 * "empty taken" if they are empty.
1382			 */
1383			ubifs_assert(c->lst.taken_empty_lebs > 0);
1384		}
1385	} else
1386		ubifs_assert(c->lst.taken_empty_lebs > 0);
1387
1388	err = dbg_check_filesystem(c);
1389	if (err)
1390		goto out_infos;
1391
1392	err = dbg_debugfs_init_fs(c);
1393	if (err)
1394		goto out_infos;
1395
1396	c->mounting = 0;
1397
1398	ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"%s",
1399		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1400		  c->ro_mount ? ", R/O mode" : "");
1401	x = (long long)c->main_lebs * c->leb_size;
1402	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1403	ubifs_msg("LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1404		  c->leb_size, c->leb_size >> 10, c->min_io_size,
1405		  c->max_write_size);
1406	ubifs_msg("FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
1407		  x, x >> 20, c->main_lebs,
1408		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
1409	ubifs_msg("reserved for root: %llu bytes (%llu KiB)",
1410		  c->report_rp_size, c->report_rp_size >> 10);
1411	ubifs_msg("media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1412		  c->fmt_version, c->ro_compat_version,
1413		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1414		  c->big_lpt ? ", big LPT model" : ", small LPT model");
1415
1416	dbg_gen("default compressor:  %s", ubifs_compr_name(c->default_compr));
1417	dbg_gen("data journal heads:  %d",
1418		c->jhead_cnt - NONDATA_JHEADS_CNT);
1419	dbg_gen("log LEBs:            %d (%d - %d)",
1420		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1421	dbg_gen("LPT area LEBs:       %d (%d - %d)",
1422		c->lpt_lebs, c->lpt_first, c->lpt_last);
1423	dbg_gen("orphan area LEBs:    %d (%d - %d)",
1424		c->orph_lebs, c->orph_first, c->orph_last);
1425	dbg_gen("main area LEBs:      %d (%d - %d)",
1426		c->main_lebs, c->main_first, c->leb_cnt - 1);
1427	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1428	dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
1429		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1430		c->bi.old_idx_sz >> 20);
1431	dbg_gen("key hash type:       %d", c->key_hash_type);
1432	dbg_gen("tree fanout:         %d", c->fanout);
1433	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1434	dbg_gen("max. znode size      %d", c->max_znode_sz);
1435	dbg_gen("max. index node size %d", c->max_idx_node_sz);
1436	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1437		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1438	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1439		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1440	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1441		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1442	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1443		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1444		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1445	dbg_gen("dead watermark:      %d", c->dead_wm);
1446	dbg_gen("dark watermark:      %d", c->dark_wm);
1447	dbg_gen("LEB overhead:        %d", c->leb_overhead);
1448	x = (long long)c->main_lebs * c->dark_wm;
1449	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1450		x, x >> 10, x >> 20);
1451	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1452		c->max_bud_bytes, c->max_bud_bytes >> 10,
1453		c->max_bud_bytes >> 20);
1454	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1455		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1456		c->bg_bud_bytes >> 20);
1457	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1458		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1459	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1460	dbg_gen("commit number:       %llu", c->cmt_no);
1461
1462	return 0;
1463
1464out_infos:
1465	spin_lock(&ubifs_infos_lock);
1466	list_del(&c->infos_list);
1467	spin_unlock(&ubifs_infos_lock);
1468out_orphans:
1469	free_orphans(c);
1470out_journal:
1471	destroy_journal(c);
1472out_lpt:
1473	ubifs_lpt_free(c, 0);
1474out_master:
1475	kfree(c->mst_node);
1476	kfree(c->rcvrd_mst_node);
1477	if (c->bgt)
1478		kthread_stop(c->bgt);
1479out_wbufs:
1480	free_wbufs(c);
1481out_cbuf:
1482	kfree(c->cbuf);
1483out_free:
1484	kfree(c->write_reserve_buf);
1485	kfree(c->bu.buf);
1486	vfree(c->ileb_buf);
1487	vfree(c->sbuf);
1488	kfree(c->bottom_up_buf);
1489	ubifs_debugging_exit(c);
1490	return err;
1491}
1492
1493/**
1494 * ubifs_umount - un-mount UBIFS file-system.
1495 * @c: UBIFS file-system description object
1496 *
1497 * Note, this function is called to free allocated resourced when un-mounting,
1498 * as well as free resources when an error occurred while we were half way
1499 * through mounting (error path cleanup function). So it has to make sure the
1500 * resource was actually allocated before freeing it.
1501 */
1502static void ubifs_umount(struct ubifs_info *c)
1503{
1504	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1505		c->vi.vol_id);
1506
1507	dbg_debugfs_exit_fs(c);
1508	spin_lock(&ubifs_infos_lock);
1509	list_del(&c->infos_list);
1510	spin_unlock(&ubifs_infos_lock);
1511
1512	if (c->bgt)
1513		kthread_stop(c->bgt);
1514
1515	destroy_journal(c);
1516	free_wbufs(c);
1517	free_orphans(c);
1518	ubifs_lpt_free(c, 0);
1519
1520	kfree(c->cbuf);
1521	kfree(c->rcvrd_mst_node);
1522	kfree(c->mst_node);
1523	kfree(c->write_reserve_buf);
1524	kfree(c->bu.buf);
1525	vfree(c->ileb_buf);
1526	vfree(c->sbuf);
1527	kfree(c->bottom_up_buf);
1528	ubifs_debugging_exit(c);
1529}
1530
1531/**
1532 * ubifs_remount_rw - re-mount in read-write mode.
1533 * @c: UBIFS file-system description object
1534 *
1535 * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1536 * mode. This function allocates the needed resources and re-mounts UBIFS in
1537 * read-write mode.
1538 */
1539static int ubifs_remount_rw(struct ubifs_info *c)
1540{
1541	int err, lnum;
1542
1543	if (c->rw_incompat) {
1544		ubifs_err("the file-system is not R/W-compatible");
1545		ubifs_msg("on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1546			  c->fmt_version, c->ro_compat_version,
1547			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1548		return -EROFS;
1549	}
1550
1551	mutex_lock(&c->umount_mutex);
1552	dbg_save_space_info(c);
1553	c->remounting_rw = 1;
1554	c->ro_mount = 0;
1555
1556	if (c->space_fixup) {
1557		err = ubifs_fixup_free_space(c);
1558		if (err)
1559			goto out;
1560	}
1561
1562	err = check_free_space(c);
1563	if (err)
1564		goto out;
1565
1566	if (c->old_leb_cnt != c->leb_cnt) {
1567		struct ubifs_sb_node *sup;
1568
1569		sup = ubifs_read_sb_node(c);
1570		if (IS_ERR(sup)) {
1571			err = PTR_ERR(sup);
1572			goto out;
1573		}
1574		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1575		err = ubifs_write_sb_node(c, sup);
1576		kfree(sup);
1577		if (err)
1578			goto out;
1579	}
1580
1581	if (c->need_recovery) {
1582		ubifs_msg("completing deferred recovery");
1583		err = ubifs_write_rcvrd_mst_node(c);
1584		if (err)
1585			goto out;
1586		err = ubifs_recover_size(c);
1587		if (err)
1588			goto out;
1589		err = ubifs_clean_lebs(c, c->sbuf);
1590		if (err)
1591			goto out;
1592		err = ubifs_recover_inl_heads(c, c->sbuf);
1593		if (err)
1594			goto out;
1595	} else {
1596		/* A readonly mount is not allowed to have orphans */
1597		ubifs_assert(c->tot_orphans == 0);
1598		err = ubifs_clear_orphans(c);
1599		if (err)
1600			goto out;
1601	}
1602
1603	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1604		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1605		err = ubifs_write_master(c);
1606		if (err)
1607			goto out;
1608	}
1609
1610	c->ileb_buf = vmalloc(c->leb_size);
1611	if (!c->ileb_buf) {
1612		err = -ENOMEM;
1613		goto out;
1614	}
1615
1616	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
 
1617	if (!c->write_reserve_buf) {
1618		err = -ENOMEM;
1619		goto out;
1620	}
1621
1622	err = ubifs_lpt_init(c, 0, 1);
1623	if (err)
1624		goto out;
1625
1626	/* Create background thread */
1627	c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1628	if (IS_ERR(c->bgt)) {
1629		err = PTR_ERR(c->bgt);
1630		c->bgt = NULL;
1631		ubifs_err("cannot spawn \"%s\", error %d",
1632			  c->bgt_name, err);
1633		goto out;
1634	}
1635	wake_up_process(c->bgt);
1636
1637	c->orph_buf = vmalloc(c->leb_size);
1638	if (!c->orph_buf) {
1639		err = -ENOMEM;
1640		goto out;
1641	}
1642
1643	/* Check for enough log space */
1644	lnum = c->lhead_lnum + 1;
1645	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1646		lnum = UBIFS_LOG_LNUM;
1647	if (lnum == c->ltail_lnum) {
1648		err = ubifs_consolidate_log(c);
1649		if (err)
1650			goto out;
1651	}
1652
1653	if (c->need_recovery)
1654		err = ubifs_rcvry_gc_commit(c);
1655	else
1656		err = ubifs_leb_unmap(c, c->gc_lnum);
1657	if (err)
1658		goto out;
1659
1660	dbg_gen("re-mounted read-write");
1661	c->remounting_rw = 0;
1662
1663	if (c->need_recovery) {
1664		c->need_recovery = 0;
1665		ubifs_msg("deferred recovery completed");
1666	} else {
1667		/*
1668		 * Do not run the debugging space check if the were doing
1669		 * recovery, because when we saved the information we had the
1670		 * file-system in a state where the TNC and lprops has been
1671		 * modified in memory, but all the I/O operations (including a
1672		 * commit) were deferred. So the file-system was in
1673		 * "non-committed" state. Now the file-system is in committed
1674		 * state, and of course the amount of free space will change
1675		 * because, for example, the old index size was imprecise.
1676		 */
1677		err = dbg_check_space_info(c);
1678	}
1679
1680	mutex_unlock(&c->umount_mutex);
1681	return err;
1682
1683out:
1684	c->ro_mount = 1;
1685	vfree(c->orph_buf);
1686	c->orph_buf = NULL;
1687	if (c->bgt) {
1688		kthread_stop(c->bgt);
1689		c->bgt = NULL;
1690	}
1691	free_wbufs(c);
1692	kfree(c->write_reserve_buf);
1693	c->write_reserve_buf = NULL;
1694	vfree(c->ileb_buf);
1695	c->ileb_buf = NULL;
1696	ubifs_lpt_free(c, 1);
1697	c->remounting_rw = 0;
1698	mutex_unlock(&c->umount_mutex);
1699	return err;
1700}
1701
1702/**
1703 * ubifs_remount_ro - re-mount in read-only mode.
1704 * @c: UBIFS file-system description object
1705 *
1706 * We assume VFS has stopped writing. Possibly the background thread could be
1707 * running a commit, however kthread_stop will wait in that case.
1708 */
1709static void ubifs_remount_ro(struct ubifs_info *c)
1710{
1711	int i, err;
1712
1713	ubifs_assert(!c->need_recovery);
1714	ubifs_assert(!c->ro_mount);
1715
1716	mutex_lock(&c->umount_mutex);
1717	if (c->bgt) {
1718		kthread_stop(c->bgt);
1719		c->bgt = NULL;
1720	}
1721
1722	dbg_save_space_info(c);
1723
1724	for (i = 0; i < c->jhead_cnt; i++)
1725		ubifs_wbuf_sync(&c->jheads[i].wbuf);
 
 
 
1726
1727	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1728	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1729	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1730	err = ubifs_write_master(c);
1731	if (err)
1732		ubifs_ro_mode(c, err);
1733
1734	vfree(c->orph_buf);
1735	c->orph_buf = NULL;
1736	kfree(c->write_reserve_buf);
1737	c->write_reserve_buf = NULL;
1738	vfree(c->ileb_buf);
1739	c->ileb_buf = NULL;
1740	ubifs_lpt_free(c, 1);
1741	c->ro_mount = 1;
1742	err = dbg_check_space_info(c);
1743	if (err)
1744		ubifs_ro_mode(c, err);
1745	mutex_unlock(&c->umount_mutex);
1746}
1747
1748static void ubifs_put_super(struct super_block *sb)
1749{
1750	int i;
1751	struct ubifs_info *c = sb->s_fs_info;
1752
1753	ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
1754		  c->vi.vol_id);
1755
1756	/*
1757	 * The following asserts are only valid if there has not been a failure
1758	 * of the media. For example, there will be dirty inodes if we failed
1759	 * to write them back because of I/O errors.
1760	 */
1761	if (!c->ro_error) {
1762		ubifs_assert(c->bi.idx_growth == 0);
1763		ubifs_assert(c->bi.dd_growth == 0);
1764		ubifs_assert(c->bi.data_growth == 0);
1765	}
1766
1767	/*
1768	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1769	 * and file system un-mount. Namely, it prevents the shrinker from
1770	 * picking this superblock for shrinking - it will be just skipped if
1771	 * the mutex is locked.
1772	 */
1773	mutex_lock(&c->umount_mutex);
1774	if (!c->ro_mount) {
1775		/*
1776		 * First of all kill the background thread to make sure it does
1777		 * not interfere with un-mounting and freeing resources.
1778		 */
1779		if (c->bgt) {
1780			kthread_stop(c->bgt);
1781			c->bgt = NULL;
1782		}
1783
1784		/*
1785		 * On fatal errors c->ro_error is set to 1, in which case we do
1786		 * not write the master node.
1787		 */
1788		if (!c->ro_error) {
1789			int err;
1790
1791			/* Synchronize write-buffers */
1792			for (i = 0; i < c->jhead_cnt; i++)
1793				ubifs_wbuf_sync(&c->jheads[i].wbuf);
 
 
 
1794
1795			/*
1796			 * We are being cleanly unmounted which means the
1797			 * orphans were killed - indicate this in the master
1798			 * node. Also save the reserved GC LEB number.
1799			 */
1800			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1801			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1802			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1803			err = ubifs_write_master(c);
1804			if (err)
1805				/*
1806				 * Recovery will attempt to fix the master area
1807				 * next mount, so we just print a message and
1808				 * continue to unmount normally.
1809				 */
1810				ubifs_err("failed to write master node, error %d",
1811					  err);
1812		} else {
1813			for (i = 0; i < c->jhead_cnt; i++)
1814				/* Make sure write-buffer timers are canceled */
1815				hrtimer_cancel(&c->jheads[i].wbuf.timer);
1816		}
1817	}
1818
1819	ubifs_umount(c);
1820	bdi_destroy(&c->bdi);
1821	ubi_close_volume(c->ubi);
1822	mutex_unlock(&c->umount_mutex);
1823}
1824
1825static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1826{
1827	int err;
1828	struct ubifs_info *c = sb->s_fs_info;
1829
1830	sync_filesystem(sb);
1831	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1832
1833	err = ubifs_parse_options(c, data, 1);
1834	if (err) {
1835		ubifs_err("invalid or unknown remount parameter");
1836		return err;
1837	}
1838
1839	if (c->ro_mount && !(*flags & MS_RDONLY)) {
1840		if (c->ro_error) {
1841			ubifs_msg("cannot re-mount R/W due to prior errors");
1842			return -EROFS;
1843		}
1844		if (c->ro_media) {
1845			ubifs_msg("cannot re-mount R/W - UBI volume is R/O");
1846			return -EROFS;
1847		}
1848		err = ubifs_remount_rw(c);
1849		if (err)
1850			return err;
1851	} else if (!c->ro_mount && (*flags & MS_RDONLY)) {
1852		if (c->ro_error) {
1853			ubifs_msg("cannot re-mount R/O due to prior errors");
1854			return -EROFS;
1855		}
1856		ubifs_remount_ro(c);
1857	}
1858
1859	if (c->bulk_read == 1)
1860		bu_init(c);
1861	else {
1862		dbg_gen("disable bulk-read");
 
1863		kfree(c->bu.buf);
1864		c->bu.buf = NULL;
 
1865	}
1866
1867	ubifs_assert(c->lst.taken_empty_lebs > 0);
1868	return 0;
1869}
1870
1871const struct super_operations ubifs_super_operations = {
1872	.alloc_inode   = ubifs_alloc_inode,
1873	.destroy_inode = ubifs_destroy_inode,
1874	.put_super     = ubifs_put_super,
1875	.write_inode   = ubifs_write_inode,
1876	.evict_inode   = ubifs_evict_inode,
1877	.statfs        = ubifs_statfs,
1878	.dirty_inode   = ubifs_dirty_inode,
1879	.remount_fs    = ubifs_remount_fs,
1880	.show_options  = ubifs_show_options,
1881	.sync_fs       = ubifs_sync_fs,
1882};
1883
1884/**
1885 * open_ubi - parse UBI device name string and open the UBI device.
1886 * @name: UBI volume name
1887 * @mode: UBI volume open mode
1888 *
1889 * The primary method of mounting UBIFS is by specifying the UBI volume
1890 * character device node path. However, UBIFS may also be mounted withoug any
1891 * character device node using one of the following methods:
1892 *
1893 * o ubiX_Y    - mount UBI device number X, volume Y;
1894 * o ubiY      - mount UBI device number 0, volume Y;
1895 * o ubiX:NAME - mount UBI device X, volume with name NAME;
1896 * o ubi:NAME  - mount UBI device 0, volume with name NAME.
1897 *
1898 * Alternative '!' separator may be used instead of ':' (because some shells
1899 * like busybox may interpret ':' as an NFS host name separator). This function
1900 * returns UBI volume description object in case of success and a negative
1901 * error code in case of failure.
1902 */
1903static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1904{
1905	struct ubi_volume_desc *ubi;
1906	int dev, vol;
1907	char *endptr;
1908
1909	/* First, try to open using the device node path method */
1910	ubi = ubi_open_volume_path(name, mode);
1911	if (!IS_ERR(ubi))
1912		return ubi;
1913
1914	/* Try the "nodev" method */
1915	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1916		return ERR_PTR(-EINVAL);
1917
1918	/* ubi:NAME method */
1919	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1920		return ubi_open_volume_nm(0, name + 4, mode);
1921
1922	if (!isdigit(name[3]))
1923		return ERR_PTR(-EINVAL);
1924
1925	dev = simple_strtoul(name + 3, &endptr, 0);
1926
1927	/* ubiY method */
1928	if (*endptr == '\0')
1929		return ubi_open_volume(0, dev, mode);
1930
1931	/* ubiX_Y method */
1932	if (*endptr == '_' && isdigit(endptr[1])) {
1933		vol = simple_strtoul(endptr + 1, &endptr, 0);
1934		if (*endptr != '\0')
1935			return ERR_PTR(-EINVAL);
1936		return ubi_open_volume(dev, vol, mode);
1937	}
1938
1939	/* ubiX:NAME method */
1940	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1941		return ubi_open_volume_nm(dev, ++endptr, mode);
1942
1943	return ERR_PTR(-EINVAL);
1944}
1945
1946static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1947{
1948	struct ubifs_info *c;
1949
1950	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1951	if (c) {
1952		spin_lock_init(&c->cnt_lock);
1953		spin_lock_init(&c->cs_lock);
1954		spin_lock_init(&c->buds_lock);
1955		spin_lock_init(&c->space_lock);
1956		spin_lock_init(&c->orphan_lock);
1957		init_rwsem(&c->commit_sem);
1958		mutex_init(&c->lp_mutex);
1959		mutex_init(&c->tnc_mutex);
1960		mutex_init(&c->log_mutex);
1961		mutex_init(&c->mst_mutex);
1962		mutex_init(&c->umount_mutex);
1963		mutex_init(&c->bu_mutex);
1964		mutex_init(&c->write_reserve_mutex);
1965		init_waitqueue_head(&c->cmt_wq);
1966		c->buds = RB_ROOT;
1967		c->old_idx = RB_ROOT;
1968		c->size_tree = RB_ROOT;
1969		c->orph_tree = RB_ROOT;
1970		INIT_LIST_HEAD(&c->infos_list);
1971		INIT_LIST_HEAD(&c->idx_gc);
1972		INIT_LIST_HEAD(&c->replay_list);
1973		INIT_LIST_HEAD(&c->replay_buds);
1974		INIT_LIST_HEAD(&c->uncat_list);
1975		INIT_LIST_HEAD(&c->empty_list);
1976		INIT_LIST_HEAD(&c->freeable_list);
1977		INIT_LIST_HEAD(&c->frdi_idx_list);
1978		INIT_LIST_HEAD(&c->unclean_leb_list);
1979		INIT_LIST_HEAD(&c->old_buds);
1980		INIT_LIST_HEAD(&c->orph_list);
1981		INIT_LIST_HEAD(&c->orph_new);
1982		c->no_chk_data_crc = 1;
1983
1984		c->highest_inum = UBIFS_FIRST_INO;
1985		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
1986
1987		ubi_get_volume_info(ubi, &c->vi);
1988		ubi_get_device_info(c->vi.ubi_num, &c->di);
1989	}
1990	return c;
1991}
1992
1993static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
1994{
1995	struct ubifs_info *c = sb->s_fs_info;
1996	struct inode *root;
1997	int err;
1998
1999	c->vfs_sb = sb;
2000	/* Re-open the UBI device in read-write mode */
2001	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2002	if (IS_ERR(c->ubi)) {
2003		err = PTR_ERR(c->ubi);
2004		goto out;
2005	}
2006
 
 
 
 
2007	/*
2008	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2009	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
2010	 * which means the user would have to wait not just for their own I/O
2011	 * but the read-ahead I/O as well i.e. completely pointless.
2012	 *
2013	 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
 
 
2014	 */
2015	c->bdi.name = "ubifs",
2016	c->bdi.capabilities = BDI_CAP_MAP_COPY;
2017	err  = bdi_init(&c->bdi);
2018	if (err)
2019		goto out_close;
2020	err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2021			   c->vi.ubi_num, c->vi.vol_id);
2022	if (err)
2023		goto out_bdi;
2024
2025	err = ubifs_parse_options(c, data, 0);
2026	if (err)
2027		goto out_bdi;
2028
2029	sb->s_bdi = &c->bdi;
2030	sb->s_fs_info = c;
2031	sb->s_magic = UBIFS_SUPER_MAGIC;
2032	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2033	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2034	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2035	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2036		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2037	sb->s_op = &ubifs_super_operations;
 
 
 
 
2038
2039	mutex_lock(&c->umount_mutex);
2040	err = mount_ubifs(c);
2041	if (err) {
2042		ubifs_assert(err < 0);
2043		goto out_unlock;
2044	}
2045
2046	/* Read the root inode */
2047	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2048	if (IS_ERR(root)) {
2049		err = PTR_ERR(root);
2050		goto out_umount;
2051	}
2052
2053	sb->s_root = d_make_root(root);
2054	if (!sb->s_root) {
2055		err = -ENOMEM;
2056		goto out_umount;
2057	}
2058
2059	mutex_unlock(&c->umount_mutex);
2060	return 0;
2061
2062out_umount:
2063	ubifs_umount(c);
2064out_unlock:
2065	mutex_unlock(&c->umount_mutex);
2066out_bdi:
2067	bdi_destroy(&c->bdi);
2068out_close:
2069	ubi_close_volume(c->ubi);
2070out:
2071	return err;
2072}
2073
2074static int sb_test(struct super_block *sb, void *data)
2075{
2076	struct ubifs_info *c1 = data;
2077	struct ubifs_info *c = sb->s_fs_info;
2078
2079	return c->vi.cdev == c1->vi.cdev;
2080}
2081
2082static int sb_set(struct super_block *sb, void *data)
2083{
2084	sb->s_fs_info = data;
2085	return set_anon_super(sb, NULL);
2086}
2087
2088static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2089			const char *name, void *data)
2090{
2091	struct ubi_volume_desc *ubi;
2092	struct ubifs_info *c;
2093	struct super_block *sb;
2094	int err;
2095
2096	dbg_gen("name %s, flags %#x", name, flags);
2097
2098	/*
2099	 * Get UBI device number and volume ID. Mount it read-only so far
2100	 * because this might be a new mount point, and UBI allows only one
2101	 * read-write user at a time.
2102	 */
2103	ubi = open_ubi(name, UBI_READONLY);
2104	if (IS_ERR(ubi)) {
2105		ubifs_err("cannot open \"%s\", error %d",
2106			  name, (int)PTR_ERR(ubi));
 
2107		return ERR_CAST(ubi);
2108	}
2109
2110	c = alloc_ubifs_info(ubi);
2111	if (!c) {
2112		err = -ENOMEM;
2113		goto out_close;
2114	}
2115
2116	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2117
2118	sb = sget(fs_type, sb_test, sb_set, flags, c);
2119	if (IS_ERR(sb)) {
2120		err = PTR_ERR(sb);
2121		kfree(c);
2122		goto out_close;
2123	}
2124
2125	if (sb->s_root) {
2126		struct ubifs_info *c1 = sb->s_fs_info;
2127		kfree(c);
2128		/* A new mount point for already mounted UBIFS */
2129		dbg_gen("this ubi volume is already mounted");
2130		if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2131			err = -EBUSY;
2132			goto out_deact;
2133		}
2134	} else {
2135		err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2136		if (err)
2137			goto out_deact;
2138		/* We do not support atime */
2139		sb->s_flags |= MS_ACTIVE | MS_NOATIME;
 
 
 
 
 
2140	}
2141
2142	/* 'fill_super()' opens ubi again so we must close it here */
2143	ubi_close_volume(ubi);
2144
2145	return dget(sb->s_root);
2146
2147out_deact:
2148	deactivate_locked_super(sb);
2149out_close:
2150	ubi_close_volume(ubi);
2151	return ERR_PTR(err);
2152}
2153
2154static void kill_ubifs_super(struct super_block *s)
2155{
2156	struct ubifs_info *c = s->s_fs_info;
2157	kill_anon_super(s);
2158	kfree(c);
2159}
2160
2161static struct file_system_type ubifs_fs_type = {
2162	.name    = "ubifs",
2163	.owner   = THIS_MODULE,
2164	.mount   = ubifs_mount,
2165	.kill_sb = kill_ubifs_super,
2166};
2167MODULE_ALIAS_FS("ubifs");
2168
2169/*
2170 * Inode slab cache constructor.
2171 */
2172static void inode_slab_ctor(void *obj)
2173{
2174	struct ubifs_inode *ui = obj;
2175	inode_init_once(&ui->vfs_inode);
2176}
2177
2178static int __init ubifs_init(void)
2179{
2180	int err;
2181
2182	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2183
2184	/* Make sure node sizes are 8-byte aligned */
2185	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2186	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2187	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2188	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2189	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2190	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2191	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2192	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2193	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2194	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2195	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2196
2197	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2198	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2199	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2200	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2201	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2202	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2203
2204	/* Check min. node size */
2205	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2206	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2207	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2208	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2209
2210	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2211	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2212	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2213	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2214
2215	/* Defined node sizes */
2216	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2217	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2218	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2219	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2220
2221	/*
2222	 * We use 2 bit wide bit-fields to store compression type, which should
2223	 * be amended if more compressors are added. The bit-fields are:
2224	 * @compr_type in 'struct ubifs_inode', @default_compr in
2225	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2226	 */
2227	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2228
2229	/*
2230	 * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
2231	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2232	 */
2233	if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
2234		ubifs_err("VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2235			  (unsigned int)PAGE_CACHE_SIZE);
2236		return -EINVAL;
2237	}
2238
2239	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2240				sizeof(struct ubifs_inode), 0,
2241				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
2242				&inode_slab_ctor);
2243	if (!ubifs_inode_slab)
2244		return -ENOMEM;
2245
2246	register_shrinker(&ubifs_shrinker_info);
 
 
2247
2248	err = ubifs_compressors_init();
2249	if (err)
2250		goto out_shrinker;
2251
2252	err = dbg_debugfs_init();
2253	if (err)
2254		goto out_compr;
2255
2256	err = register_filesystem(&ubifs_fs_type);
2257	if (err) {
2258		ubifs_err("cannot register file system, error %d", err);
 
2259		goto out_dbg;
2260	}
2261	return 0;
2262
2263out_dbg:
2264	dbg_debugfs_exit();
2265out_compr:
2266	ubifs_compressors_exit();
2267out_shrinker:
2268	unregister_shrinker(&ubifs_shrinker_info);
 
2269	kmem_cache_destroy(ubifs_inode_slab);
2270	return err;
2271}
2272/* late_initcall to let compressors initialize first */
2273late_initcall(ubifs_init);
2274
2275static void __exit ubifs_exit(void)
2276{
2277	ubifs_assert(list_empty(&ubifs_infos));
2278	ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2279
2280	dbg_debugfs_exit();
2281	ubifs_compressors_exit();
2282	unregister_shrinker(&ubifs_shrinker_info);
2283
2284	/*
2285	 * Make sure all delayed rcu free inodes are flushed before we
2286	 * destroy cache.
2287	 */
2288	rcu_barrier();
2289	kmem_cache_destroy(ubifs_inode_slab);
2290	unregister_filesystem(&ubifs_fs_type);
2291}
2292module_exit(ubifs_exit);
2293
2294MODULE_LICENSE("GPL");
2295MODULE_VERSION(__stringify(UBIFS_VERSION));
2296MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2297MODULE_DESCRIPTION("UBIFS - UBI File System");