1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/ext4/super.c
   4 *
   5 * Copyright (C) 1992, 1993, 1994, 1995
   6 * Remy Card (card@masi.ibp.fr)
   7 * Laboratoire MASI - Institut Blaise Pascal
   8 * Universite Pierre et Marie Curie (Paris VI)
   9 *
  10 *  from
  11 *
  12 *  linux/fs/minix/inode.c
  13 *
  14 *  Copyright (C) 1991, 1992  Linus Torvalds
  15 *
  16 *  Big-endian to little-endian byte-swapping/bitmaps by
  17 *        David S. Miller (davem@caip.rutgers.edu), 1995
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/string.h>
  22#include <linux/fs.h>
  23#include <linux/time.h>
  24#include <linux/vmalloc.h>
  25#include <linux/slab.h>
  26#include <linux/init.h>
  27#include <linux/blkdev.h>
  28#include <linux/backing-dev.h>
  29#include <linux/parser.h>
  30#include <linux/buffer_head.h>
  31#include <linux/exportfs.h>
  32#include <linux/vfs.h>
  33#include <linux/random.h>
  34#include <linux/mount.h>
  35#include <linux/namei.h>
  36#include <linux/quotaops.h>
  37#include <linux/seq_file.h>
  38#include <linux/ctype.h>
  39#include <linux/log2.h>
  40#include <linux/crc16.h>
  41#include <linux/dax.h>
  42#include <linux/cleancache.h>
  43#include <linux/uaccess.h>
  44#include <linux/iversion.h>
  45
  46#include <linux/kthread.h>
  47#include <linux/freezer.h>
  48
  49#include "ext4.h"
  50#include "ext4_extents.h"	/* Needed for trace points definition */
  51#include "ext4_jbd2.h"
  52#include "xattr.h"
  53#include "acl.h"
  54#include "mballoc.h"
  55#include "fsmap.h"
  56
  57#define CREATE_TRACE_POINTS
  58#include <trace/events/ext4.h>
  59
  60static struct ext4_lazy_init *ext4_li_info;
  61static struct mutex ext4_li_mtx;
  62static struct ratelimit_state ext4_mount_msg_ratelimit;
  63
  64static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65			     unsigned long journal_devnum);
  66static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67static int ext4_commit_super(struct super_block *sb, int sync);
  68static void ext4_mark_recovery_complete(struct super_block *sb,
  69					struct ext4_super_block *es);
  70static void ext4_clear_journal_err(struct super_block *sb,
  71				   struct ext4_super_block *es);
  72static int ext4_sync_fs(struct super_block *sb, int wait);
  73static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75static int ext4_unfreeze(struct super_block *sb);
  76static int ext4_freeze(struct super_block *sb);
  77static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78		       const char *dev_name, void *data);
  79static inline int ext2_feature_set_ok(struct super_block *sb);
  80static inline int ext3_feature_set_ok(struct super_block *sb);
  81static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82static void ext4_destroy_lazyinit_thread(void);
  83static void ext4_unregister_li_request(struct super_block *sb);
  84static void ext4_clear_request_list(void);
  85static struct inode *ext4_get_journal_inode(struct super_block *sb,
  86					    unsigned int journal_inum);
  87
  88/*
  89 * Lock ordering
  90 *
  91 * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  92 * i_mmap_rwsem (inode->i_mmap_rwsem)!
  93 *
  94 * page fault path:
  95 * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  96 *   page lock -> i_data_sem (rw)
  97 *
  98 * buffered write path:
  99 * sb_start_write -> i_mutex -> mmap_sem
 100 * sb_start_write -> i_mutex -> transaction start -> page lock ->
 101 *   i_data_sem (rw)
 102 *
 103 * truncate:
 104 * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
 105 * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
 106 *   i_data_sem (rw)
 
 107 *
 108 * direct IO:
 109 * sb_start_write -> i_mutex -> mmap_sem
 110 * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
 
 111 *
 112 * writepages:
 113 * transaction start -> page lock(s) -> i_data_sem (rw)
 114 */
 115
 116#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 117static struct file_system_type ext2_fs_type = {
 118	.owner		= THIS_MODULE,
 119	.name		= "ext2",
 120	.mount		= ext4_mount,
 121	.kill_sb	= kill_block_super,
 122	.fs_flags	= FS_REQUIRES_DEV,
 123};
 124MODULE_ALIAS_FS("ext2");
 125MODULE_ALIAS("ext2");
 126#define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 127#else
 128#define IS_EXT2_SB(sb) (0)
 129#endif
 130
 131
 132static struct file_system_type ext3_fs_type = {
 133	.owner		= THIS_MODULE,
 134	.name		= "ext3",
 135	.mount		= ext4_mount,
 136	.kill_sb	= kill_block_super,
 137	.fs_flags	= FS_REQUIRES_DEV,
 138};
 139MODULE_ALIAS_FS("ext3");
 140MODULE_ALIAS("ext3");
 141#define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 142
 143static int ext4_verify_csum_type(struct super_block *sb,
 144				 struct ext4_super_block *es)
 145{
 146	if (!ext4_has_feature_metadata_csum(sb))
 147		return 1;
 148
 149	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 150}
 151
 152static __le32 ext4_superblock_csum(struct super_block *sb,
 153				   struct ext4_super_block *es)
 154{
 155	struct ext4_sb_info *sbi = EXT4_SB(sb);
 156	int offset = offsetof(struct ext4_super_block, s_checksum);
 157	__u32 csum;
 158
 159	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 160
 161	return cpu_to_le32(csum);
 162}
 163
 164static int ext4_superblock_csum_verify(struct super_block *sb,
 165				       struct ext4_super_block *es)
 166{
 167	if (!ext4_has_metadata_csum(sb))
 168		return 1;
 169
 170	return es->s_checksum == ext4_superblock_csum(sb, es);
 171}
 172
 173void ext4_superblock_csum_set(struct super_block *sb)
 174{
 175	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 176
 177	if (!ext4_has_metadata_csum(sb))
 178		return;
 179
 180	es->s_checksum = ext4_superblock_csum(sb, es);
 181}
 182
 183void *ext4_kvmalloc(size_t size, gfp_t flags)
 184{
 185	void *ret;
 186
 187	ret = kmalloc(size, flags | __GFP_NOWARN);
 188	if (!ret)
 189		ret = __vmalloc(size, flags, PAGE_KERNEL);
 190	return ret;
 191}
 192
 193void *ext4_kvzalloc(size_t size, gfp_t flags)
 194{
 195	void *ret;
 196
 197	ret = kzalloc(size, flags | __GFP_NOWARN);
 198	if (!ret)
 199		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 200	return ret;
 201}
 202
 203ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 204			       struct ext4_group_desc *bg)
 205{
 206	return le32_to_cpu(bg->bg_block_bitmap_lo) |
 207		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 209}
 210
 211ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 212			       struct ext4_group_desc *bg)
 213{
 214	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 215		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 217}
 218
 219ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 220			      struct ext4_group_desc *bg)
 221{
 222	return le32_to_cpu(bg->bg_inode_table_lo) |
 223		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 225}
 226
 227__u32 ext4_free_group_clusters(struct super_block *sb,
 228			       struct ext4_group_desc *bg)
 229{
 230	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 231		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 233}
 234
 235__u32 ext4_free_inodes_count(struct super_block *sb,
 236			      struct ext4_group_desc *bg)
 237{
 238	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 239		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 240		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 241}
 242
 243__u32 ext4_used_dirs_count(struct super_block *sb,
 244			      struct ext4_group_desc *bg)
 245{
 246	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 247		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 248		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 249}
 250
 251__u32 ext4_itable_unused_count(struct super_block *sb,
 252			      struct ext4_group_desc *bg)
 253{
 254	return le16_to_cpu(bg->bg_itable_unused_lo) |
 255		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 256		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 257}
 258
 259void ext4_block_bitmap_set(struct super_block *sb,
 260			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
 261{
 262	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 263	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 265}
 266
 267void ext4_inode_bitmap_set(struct super_block *sb,
 268			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
 269{
 270	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 271	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 273}
 274
 275void ext4_inode_table_set(struct super_block *sb,
 276			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
 277{
 278	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 279	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 281}
 282
 283void ext4_free_group_clusters_set(struct super_block *sb,
 284				  struct ext4_group_desc *bg, __u32 count)
 285{
 286	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 287	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 289}
 290
 291void ext4_free_inodes_set(struct super_block *sb,
 292			  struct ext4_group_desc *bg, __u32 count)
 293{
 294	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 295	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 296		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 297}
 298
 299void ext4_used_dirs_set(struct super_block *sb,
 300			  struct ext4_group_desc *bg, __u32 count)
 301{
 302	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 303	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 304		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 305}
 306
 307void ext4_itable_unused_set(struct super_block *sb,
 308			  struct ext4_group_desc *bg, __u32 count)
 309{
 310	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 311	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 312		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 313}
 314
 315
 316static void __save_error_info(struct super_block *sb, const char *func,
 317			    unsigned int line)
 318{
 319	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 320
 321	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 322	if (bdev_read_only(sb->s_bdev))
 323		return;
 324	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 325	es->s_last_error_time = cpu_to_le32(get_seconds());
 326	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 327	es->s_last_error_line = cpu_to_le32(line);
 328	if (!es->s_first_error_time) {
 329		es->s_first_error_time = es->s_last_error_time;
 330		strncpy(es->s_first_error_func, func,
 331			sizeof(es->s_first_error_func));
 332		es->s_first_error_line = cpu_to_le32(line);
 333		es->s_first_error_ino = es->s_last_error_ino;
 334		es->s_first_error_block = es->s_last_error_block;
 335	}
 336	/*
 337	 * Start the daily error reporting function if it hasn't been
 338	 * started already
 339	 */
 340	if (!es->s_error_count)
 341		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 342	le32_add_cpu(&es->s_error_count, 1);
 343}
 344
 345static void save_error_info(struct super_block *sb, const char *func,
 346			    unsigned int line)
 347{
 348	__save_error_info(sb, func, line);
 349	ext4_commit_super(sb, 1);
 350}
 351
 352/*
 353 * The del_gendisk() function uninitializes the disk-specific data
 354 * structures, including the bdi structure, without telling anyone
 355 * else.  Once this happens, any attempt to call mark_buffer_dirty()
 356 * (for example, by ext4_commit_super), will cause a kernel OOPS.
 357 * This is a kludge to prevent these oops until we can put in a proper
 358 * hook in del_gendisk() to inform the VFS and file system layers.
 359 */
 360static int block_device_ejected(struct super_block *sb)
 361{
 362	struct inode *bd_inode = sb->s_bdev->bd_inode;
 363	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 364
 365	return bdi->dev == NULL;
 366}
 367
 368static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 369{
 370	struct super_block		*sb = journal->j_private;
 371	struct ext4_sb_info		*sbi = EXT4_SB(sb);
 372	int				error = is_journal_aborted(journal);
 373	struct ext4_journal_cb_entry	*jce;
 374
 375	BUG_ON(txn->t_state == T_FINISHED);
 376
 377	ext4_process_freed_data(sb, txn->t_tid);
 378
 379	spin_lock(&sbi->s_md_lock);
 380	while (!list_empty(&txn->t_private_list)) {
 381		jce = list_entry(txn->t_private_list.next,
 382				 struct ext4_journal_cb_entry, jce_list);
 383		list_del_init(&jce->jce_list);
 384		spin_unlock(&sbi->s_md_lock);
 385		jce->jce_func(sb, jce, error);
 386		spin_lock(&sbi->s_md_lock);
 387	}
 388	spin_unlock(&sbi->s_md_lock);
 389}
 390
 391/* Deal with the reporting of failure conditions on a filesystem such as
 392 * inconsistencies detected or read IO failures.
 393 *
 394 * On ext2, we can store the error state of the filesystem in the
 395 * superblock.  That is not possible on ext4, because we may have other
 396 * write ordering constraints on the superblock which prevent us from
 397 * writing it out straight away; and given that the journal is about to
 398 * be aborted, we can't rely on the current, or future, transactions to
 399 * write out the superblock safely.
 400 *
 401 * We'll just use the jbd2_journal_abort() error code to record an error in
 402 * the journal instead.  On recovery, the journal will complain about
 403 * that error until we've noted it down and cleared it.
 404 */
 405
 406static void ext4_handle_error(struct super_block *sb)
 407{
 408	if (sb_rdonly(sb))
 409		return;
 410
 411	if (!test_opt(sb, ERRORS_CONT)) {
 412		journal_t *journal = EXT4_SB(sb)->s_journal;
 413
 414		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 415		if (journal)
 416			jbd2_journal_abort(journal, -EIO);
 417	}
 418	if (test_opt(sb, ERRORS_RO)) {
 419		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 420		/*
 421		 * Make sure updated value of ->s_mount_flags will be visible
 422		 * before ->s_flags update
 423		 */
 424		smp_wmb();
 425		sb->s_flags |= SB_RDONLY;
 426	}
 427	if (test_opt(sb, ERRORS_PANIC)) {
 428		if (EXT4_SB(sb)->s_journal &&
 429		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 430			return;
 431		panic("EXT4-fs (device %s): panic forced after error\n",
 432			sb->s_id);
 433	}
 434}
 435
 436#define ext4_error_ratelimit(sb)					\
 437		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
 438			     "EXT4-fs error")
 439
 440void __ext4_error(struct super_block *sb, const char *function,
 441		  unsigned int line, const char *fmt, ...)
 442{
 443	struct va_format vaf;
 444	va_list args;
 445
 446	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 447		return;
 448
 449	trace_ext4_error(sb, function, line);
 450	if (ext4_error_ratelimit(sb)) {
 451		va_start(args, fmt);
 452		vaf.fmt = fmt;
 453		vaf.va = &args;
 454		printk(KERN_CRIT
 455		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 456		       sb->s_id, function, line, current->comm, &vaf);
 457		va_end(args);
 458	}
 459	save_error_info(sb, function, line);
 460	ext4_handle_error(sb);
 461}
 462
 463void __ext4_error_inode(struct inode *inode, const char *function,
 464			unsigned int line, ext4_fsblk_t block,
 465			const char *fmt, ...)
 466{
 467	va_list args;
 468	struct va_format vaf;
 469	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 470
 471	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 472		return;
 473
 474	trace_ext4_error(inode->i_sb, function, line);
 475	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 476	es->s_last_error_block = cpu_to_le64(block);
 477	if (ext4_error_ratelimit(inode->i_sb)) {
 478		va_start(args, fmt);
 479		vaf.fmt = fmt;
 480		vaf.va = &args;
 481		if (block)
 482			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 483			       "inode #%lu: block %llu: comm %s: %pV\n",
 484			       inode->i_sb->s_id, function, line, inode->i_ino,
 485			       block, current->comm, &vaf);
 486		else
 487			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 488			       "inode #%lu: comm %s: %pV\n",
 489			       inode->i_sb->s_id, function, line, inode->i_ino,
 490			       current->comm, &vaf);
 491		va_end(args);
 492	}
 493	save_error_info(inode->i_sb, function, line);
 494	ext4_handle_error(inode->i_sb);
 495}
 496
 497void __ext4_error_file(struct file *file, const char *function,
 498		       unsigned int line, ext4_fsblk_t block,
 499		       const char *fmt, ...)
 500{
 501	va_list args;
 502	struct va_format vaf;
 503	struct ext4_super_block *es;
 504	struct inode *inode = file_inode(file);
 505	char pathname[80], *path;
 506
 507	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 508		return;
 509
 510	trace_ext4_error(inode->i_sb, function, line);
 511	es = EXT4_SB(inode->i_sb)->s_es;
 512	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 513	if (ext4_error_ratelimit(inode->i_sb)) {
 514		path = file_path(file, pathname, sizeof(pathname));
 515		if (IS_ERR(path))
 516			path = "(unknown)";
 517		va_start(args, fmt);
 518		vaf.fmt = fmt;
 519		vaf.va = &args;
 520		if (block)
 521			printk(KERN_CRIT
 522			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 523			       "block %llu: comm %s: path %s: %pV\n",
 524			       inode->i_sb->s_id, function, line, inode->i_ino,
 525			       block, current->comm, path, &vaf);
 526		else
 527			printk(KERN_CRIT
 528			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 529			       "comm %s: path %s: %pV\n",
 530			       inode->i_sb->s_id, function, line, inode->i_ino,
 531			       current->comm, path, &vaf);
 532		va_end(args);
 533	}
 534	save_error_info(inode->i_sb, function, line);
 535	ext4_handle_error(inode->i_sb);
 536}
 537
 538const char *ext4_decode_error(struct super_block *sb, int errno,
 539			      char nbuf[16])
 540{
 541	char *errstr = NULL;
 542
 543	switch (errno) {
 544	case -EFSCORRUPTED:
 545		errstr = "Corrupt filesystem";
 546		break;
 547	case -EFSBADCRC:
 548		errstr = "Filesystem failed CRC";
 549		break;
 550	case -EIO:
 551		errstr = "IO failure";
 552		break;
 553	case -ENOMEM:
 554		errstr = "Out of memory";
 555		break;
 556	case -EROFS:
 557		if (!sb || (EXT4_SB(sb)->s_journal &&
 558			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 559			errstr = "Journal has aborted";
 560		else
 561			errstr = "Readonly filesystem";
 562		break;
 563	default:
 564		/* If the caller passed in an extra buffer for unknown
 565		 * errors, textualise them now.  Else we just return
 566		 * NULL. */
 567		if (nbuf) {
 568			/* Check for truncated error codes... */
 569			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 570				errstr = nbuf;
 571		}
 572		break;
 573	}
 574
 575	return errstr;
 576}
 577
 578/* __ext4_std_error decodes expected errors from journaling functions
 579 * automatically and invokes the appropriate error response.  */
 580
 581void __ext4_std_error(struct super_block *sb, const char *function,
 582		      unsigned int line, int errno)
 583{
 584	char nbuf[16];
 585	const char *errstr;
 586
 587	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 588		return;
 589
 590	/* Special case: if the error is EROFS, and we're not already
 591	 * inside a transaction, then there's really no point in logging
 592	 * an error. */
 593	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
 
 594		return;
 595
 596	if (ext4_error_ratelimit(sb)) {
 597		errstr = ext4_decode_error(sb, errno, nbuf);
 598		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 599		       sb->s_id, function, line, errstr);
 600	}
 601
 602	save_error_info(sb, function, line);
 603	ext4_handle_error(sb);
 604}
 605
 606/*
 607 * ext4_abort is a much stronger failure handler than ext4_error.  The
 608 * abort function may be used to deal with unrecoverable failures such
 609 * as journal IO errors or ENOMEM at a critical moment in log management.
 610 *
 611 * We unconditionally force the filesystem into an ABORT|READONLY state,
 612 * unless the error response on the fs has been set to panic in which
 613 * case we take the easy way out and panic immediately.
 614 */
 615
 616void __ext4_abort(struct super_block *sb, const char *function,
 617		unsigned int line, const char *fmt, ...)
 618{
 619	struct va_format vaf;
 620	va_list args;
 621
 622	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 623		return;
 624
 625	save_error_info(sb, function, line);
 626	va_start(args, fmt);
 627	vaf.fmt = fmt;
 628	vaf.va = &args;
 629	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 630	       sb->s_id, function, line, &vaf);
 631	va_end(args);
 632
 633	if (sb_rdonly(sb) == 0) {
 634		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 635		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 636		/*
 637		 * Make sure updated value of ->s_mount_flags will be visible
 638		 * before ->s_flags update
 639		 */
 640		smp_wmb();
 641		sb->s_flags |= SB_RDONLY;
 642		if (EXT4_SB(sb)->s_journal)
 643			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 644		save_error_info(sb, function, line);
 645	}
 646	if (test_opt(sb, ERRORS_PANIC)) {
 647		if (EXT4_SB(sb)->s_journal &&
 648		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 649			return;
 650		panic("EXT4-fs panic from previous error\n");
 651	}
 652}
 653
 654void __ext4_msg(struct super_block *sb,
 655		const char *prefix, const char *fmt, ...)
 656{
 657	struct va_format vaf;
 658	va_list args;
 659
 660	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 661		return;
 662
 663	va_start(args, fmt);
 664	vaf.fmt = fmt;
 665	vaf.va = &args;
 666	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 667	va_end(args);
 668}
 669
 670#define ext4_warning_ratelimit(sb)					\
 671		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
 672			     "EXT4-fs warning")
 673
 674void __ext4_warning(struct super_block *sb, const char *function,
 675		    unsigned int line, const char *fmt, ...)
 676{
 677	struct va_format vaf;
 678	va_list args;
 679
 680	if (!ext4_warning_ratelimit(sb))
 681		return;
 682
 683	va_start(args, fmt);
 684	vaf.fmt = fmt;
 685	vaf.va = &args;
 686	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 687	       sb->s_id, function, line, &vaf);
 688	va_end(args);
 689}
 690
 691void __ext4_warning_inode(const struct inode *inode, const char *function,
 692			  unsigned int line, const char *fmt, ...)
 693{
 694	struct va_format vaf;
 695	va_list args;
 696
 697	if (!ext4_warning_ratelimit(inode->i_sb))
 698		return;
 699
 700	va_start(args, fmt);
 701	vaf.fmt = fmt;
 702	vaf.va = &args;
 703	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 704	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 705	       function, line, inode->i_ino, current->comm, &vaf);
 706	va_end(args);
 707}
 708
 709void __ext4_grp_locked_error(const char *function, unsigned int line,
 710			     struct super_block *sb, ext4_group_t grp,
 711			     unsigned long ino, ext4_fsblk_t block,
 712			     const char *fmt, ...)
 713__releases(bitlock)
 714__acquires(bitlock)
 715{
 716	struct va_format vaf;
 717	va_list args;
 718	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 719
 720	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 721		return;
 722
 723	trace_ext4_error(sb, function, line);
 724	es->s_last_error_ino = cpu_to_le32(ino);
 725	es->s_last_error_block = cpu_to_le64(block);
 726	__save_error_info(sb, function, line);
 727
 728	if (ext4_error_ratelimit(sb)) {
 729		va_start(args, fmt);
 730		vaf.fmt = fmt;
 731		vaf.va = &args;
 732		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 733		       sb->s_id, function, line, grp);
 734		if (ino)
 735			printk(KERN_CONT "inode %lu: ", ino);
 736		if (block)
 737			printk(KERN_CONT "block %llu:",
 738			       (unsigned long long) block);
 739		printk(KERN_CONT "%pV\n", &vaf);
 740		va_end(args);
 741	}
 742
 743	if (test_opt(sb, ERRORS_CONT)) {
 744		ext4_commit_super(sb, 0);
 745		return;
 746	}
 747
 748	ext4_unlock_group(sb, grp);
 749	ext4_commit_super(sb, 1);
 750	ext4_handle_error(sb);
 751	/*
 752	 * We only get here in the ERRORS_RO case; relocking the group
 753	 * may be dangerous, but nothing bad will happen since the
 754	 * filesystem will have already been marked read/only and the
 755	 * journal has been aborted.  We return 1 as a hint to callers
 756	 * who might what to use the return value from
 757	 * ext4_grp_locked_error() to distinguish between the
 758	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 759	 * aggressively from the ext4 function in question, with a
 760	 * more appropriate error code.
 761	 */
 762	ext4_lock_group(sb, grp);
 763	return;
 764}
 765
 766void ext4_update_dynamic_rev(struct super_block *sb)
 767{
 768	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 769
 770	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 771		return;
 772
 773	ext4_warning(sb,
 774		     "updating to rev %d because of new feature flag, "
 775		     "running e2fsck is recommended",
 776		     EXT4_DYNAMIC_REV);
 777
 778	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 779	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 780	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 781	/* leave es->s_feature_*compat flags alone */
 782	/* es->s_uuid will be set by e2fsck if empty */
 783
 784	/*
 785	 * The rest of the superblock fields should be zero, and if not it
 786	 * means they are likely already in use, so leave them alone.  We
 787	 * can leave it up to e2fsck to clean up any inconsistencies there.
 788	 */
 789}
 790
 791/*
 792 * Open the external journal device
 793 */
 794static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 795{
 796	struct block_device *bdev;
 797	char b[BDEVNAME_SIZE];
 798
 799	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 800	if (IS_ERR(bdev))
 801		goto fail;
 802	return bdev;
 803
 804fail:
 805	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 806			__bdevname(dev, b), PTR_ERR(bdev));
 807	return NULL;
 808}
 809
 810/*
 811 * Release the journal device
 812 */
 813static void ext4_blkdev_put(struct block_device *bdev)
 814{
 815	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 816}
 817
 818static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 819{
 820	struct block_device *bdev;
 821	bdev = sbi->journal_bdev;
 822	if (bdev) {
 823		ext4_blkdev_put(bdev);
 824		sbi->journal_bdev = NULL;
 825	}
 826}
 827
 828static inline struct inode *orphan_list_entry(struct list_head *l)
 829{
 830	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 831}
 832
 833static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 834{
 835	struct list_head *l;
 836
 837	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 838		 le32_to_cpu(sbi->s_es->s_last_orphan));
 839
 840	printk(KERN_ERR "sb_info orphan list:\n");
 841	list_for_each(l, &sbi->s_orphan) {
 842		struct inode *inode = orphan_list_entry(l);
 843		printk(KERN_ERR "  "
 844		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 845		       inode->i_sb->s_id, inode->i_ino, inode,
 846		       inode->i_mode, inode->i_nlink,
 847		       NEXT_ORPHAN(inode));
 848	}
 849}
 850
 851#ifdef CONFIG_QUOTA
 852static int ext4_quota_off(struct super_block *sb, int type);
 853
 854static inline void ext4_quota_off_umount(struct super_block *sb)
 855{
 856	int type;
 857
 858	/* Use our quota_off function to clear inode flags etc. */
 859	for (type = 0; type < EXT4_MAXQUOTAS; type++)
 860		ext4_quota_off(sb, type);
 861}
 862#else
 863static inline void ext4_quota_off_umount(struct super_block *sb)
 864{
 865}
 866#endif
 867
 868static void ext4_put_super(struct super_block *sb)
 869{
 870	struct ext4_sb_info *sbi = EXT4_SB(sb);
 871	struct ext4_super_block *es = sbi->s_es;
 872	int aborted = 0;
 873	int i, err;
 874
 875	ext4_unregister_li_request(sb);
 876	ext4_quota_off_umount(sb);
 877
 
 878	destroy_workqueue(sbi->rsv_conversion_wq);
 879
 880	if (sbi->s_journal) {
 881		aborted = is_journal_aborted(sbi->s_journal);
 882		err = jbd2_journal_destroy(sbi->s_journal);
 883		sbi->s_journal = NULL;
 884		if ((err < 0) && !aborted)
 885			ext4_abort(sb, "Couldn't clean up the journal");
 886	}
 887
 888	ext4_unregister_sysfs(sb);
 889	ext4_es_unregister_shrinker(sbi);
 890	del_timer_sync(&sbi->s_err_report);
 891	ext4_release_system_zone(sb);
 892	ext4_mb_release(sb);
 893	ext4_ext_release(sb);
 894
 895	if (!sb_rdonly(sb) && !aborted) {
 896		ext4_clear_feature_journal_needs_recovery(sb);
 897		es->s_state = cpu_to_le16(sbi->s_mount_state);
 898	}
 899	if (!sb_rdonly(sb))
 900		ext4_commit_super(sb, 1);
 901
 902	for (i = 0; i < sbi->s_gdb_count; i++)
 903		brelse(sbi->s_group_desc[i]);
 904	kvfree(sbi->s_group_desc);
 905	kvfree(sbi->s_flex_groups);
 906	percpu_counter_destroy(&sbi->s_freeclusters_counter);
 907	percpu_counter_destroy(&sbi->s_freeinodes_counter);
 908	percpu_counter_destroy(&sbi->s_dirs_counter);
 909	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 910	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 911#ifdef CONFIG_QUOTA
 912	for (i = 0; i < EXT4_MAXQUOTAS; i++)
 913		kfree(sbi->s_qf_names[i]);
 914#endif
 915
 916	/* Debugging code just in case the in-memory inode orphan list
 917	 * isn't empty.  The on-disk one can be non-empty if we've
 918	 * detected an error and taken the fs readonly, but the
 919	 * in-memory list had better be clean by this point. */
 920	if (!list_empty(&sbi->s_orphan))
 921		dump_orphan_list(sb, sbi);
 922	J_ASSERT(list_empty(&sbi->s_orphan));
 923
 924	sync_blockdev(sb->s_bdev);
 925	invalidate_bdev(sb->s_bdev);
 926	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 927		/*
 928		 * Invalidate the journal device's buffers.  We don't want them
 929		 * floating about in memory - the physical journal device may
 930		 * hotswapped, and it breaks the `ro-after' testing code.
 931		 */
 932		sync_blockdev(sbi->journal_bdev);
 933		invalidate_bdev(sbi->journal_bdev);
 934		ext4_blkdev_remove(sbi);
 935	}
 936	if (sbi->s_ea_inode_cache) {
 937		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
 938		sbi->s_ea_inode_cache = NULL;
 939	}
 940	if (sbi->s_ea_block_cache) {
 941		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
 942		sbi->s_ea_block_cache = NULL;
 943	}
 944	if (sbi->s_mmp_tsk)
 945		kthread_stop(sbi->s_mmp_tsk);
 946	brelse(sbi->s_sbh);
 947	sb->s_fs_info = NULL;
 948	/*
 949	 * Now that we are completely done shutting down the
 950	 * superblock, we need to actually destroy the kobject.
 951	 */
 952	kobject_put(&sbi->s_kobj);
 953	wait_for_completion(&sbi->s_kobj_unregister);
 954	if (sbi->s_chksum_driver)
 955		crypto_free_shash(sbi->s_chksum_driver);
 956	kfree(sbi->s_blockgroup_lock);
 957	fs_put_dax(sbi->s_daxdev);
 958	kfree(sbi);
 959}
 960
 961static struct kmem_cache *ext4_inode_cachep;
 962
 963/*
 964 * Called inside transaction, so use GFP_NOFS
 965 */
 966static struct inode *ext4_alloc_inode(struct super_block *sb)
 967{
 968	struct ext4_inode_info *ei;
 969
 970	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 971	if (!ei)
 972		return NULL;
 973
 974	inode_set_iversion(&ei->vfs_inode, 1);
 975	spin_lock_init(&ei->i_raw_lock);
 976	INIT_LIST_HEAD(&ei->i_prealloc_list);
 977	spin_lock_init(&ei->i_prealloc_lock);
 978	ext4_es_init_tree(&ei->i_es_tree);
 979	rwlock_init(&ei->i_es_lock);
 980	INIT_LIST_HEAD(&ei->i_es_list);
 981	ei->i_es_all_nr = 0;
 982	ei->i_es_shk_nr = 0;
 983	ei->i_es_shrink_lblk = 0;
 984	ei->i_reserved_data_blocks = 0;
 
 
 985	ei->i_da_metadata_calc_len = 0;
 986	ei->i_da_metadata_calc_last_lblock = 0;
 987	spin_lock_init(&(ei->i_block_reservation_lock));
 988#ifdef CONFIG_QUOTA
 989	ei->i_reserved_quota = 0;
 990	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 991#endif
 992	ei->jinode = NULL;
 993	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 994	spin_lock_init(&ei->i_completed_io_lock);
 995	ei->i_sync_tid = 0;
 996	ei->i_datasync_tid = 0;
 997	atomic_set(&ei->i_unwritten, 0);
 998	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 
 
 
 999	return &ei->vfs_inode;
1000}
1001
1002static int ext4_drop_inode(struct inode *inode)
1003{
1004	int drop = generic_drop_inode(inode);
1005
1006	trace_ext4_drop_inode(inode, drop);
1007	return drop;
1008}
1009
1010static void ext4_i_callback(struct rcu_head *head)
1011{
1012	struct inode *inode = container_of(head, struct inode, i_rcu);
1013	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1014}
1015
1016static void ext4_destroy_inode(struct inode *inode)
1017{
1018	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1019		ext4_msg(inode->i_sb, KERN_ERR,
1020			 "Inode %lu (%p): orphan list check failed!",
1021			 inode->i_ino, EXT4_I(inode));
1022		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1023				EXT4_I(inode), sizeof(struct ext4_inode_info),
1024				true);
1025		dump_stack();
1026	}
1027	call_rcu(&inode->i_rcu, ext4_i_callback);
1028}
1029
1030static void init_once(void *foo)
1031{
1032	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1033
1034	INIT_LIST_HEAD(&ei->i_orphan);
1035	init_rwsem(&ei->xattr_sem);
1036	init_rwsem(&ei->i_data_sem);
1037	init_rwsem(&ei->i_mmap_sem);
1038	inode_init_once(&ei->vfs_inode);
1039}
1040
1041static int __init init_inodecache(void)
1042{
1043	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1044				sizeof(struct ext4_inode_info), 0,
1045				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1046					SLAB_ACCOUNT),
1047				offsetof(struct ext4_inode_info, i_data),
1048				sizeof_field(struct ext4_inode_info, i_data),
1049				init_once);
1050	if (ext4_inode_cachep == NULL)
1051		return -ENOMEM;
1052	return 0;
1053}
1054
1055static void destroy_inodecache(void)
1056{
1057	/*
1058	 * Make sure all delayed rcu free inodes are flushed before we
1059	 * destroy cache.
1060	 */
1061	rcu_barrier();
1062	kmem_cache_destroy(ext4_inode_cachep);
1063}
1064
1065void ext4_clear_inode(struct inode *inode)
1066{
1067	invalidate_inode_buffers(inode);
1068	clear_inode(inode);
1069	dquot_drop(inode);
1070	ext4_discard_preallocations(inode);
1071	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1072	if (EXT4_I(inode)->jinode) {
1073		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1074					       EXT4_I(inode)->jinode);
1075		jbd2_free_inode(EXT4_I(inode)->jinode);
1076		EXT4_I(inode)->jinode = NULL;
1077	}
1078	fscrypt_put_encryption_info(inode);
 
 
 
1079}
1080
1081static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1082					u64 ino, u32 generation)
1083{
1084	struct inode *inode;
1085
1086	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1087		return ERR_PTR(-ESTALE);
1088	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1089		return ERR_PTR(-ESTALE);
1090
1091	/* iget isn't really right if the inode is currently unallocated!!
1092	 *
1093	 * ext4_read_inode will return a bad_inode if the inode had been
1094	 * deleted, so we should be safe.
1095	 *
1096	 * Currently we don't know the generation for parent directory, so
1097	 * a generation of 0 means "accept any"
1098	 */
1099	inode = ext4_iget_normal(sb, ino);
1100	if (IS_ERR(inode))
1101		return ERR_CAST(inode);
1102	if (generation && inode->i_generation != generation) {
1103		iput(inode);
1104		return ERR_PTR(-ESTALE);
1105	}
1106
1107	return inode;
1108}
1109
1110static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1111					int fh_len, int fh_type)
1112{
1113	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1114				    ext4_nfs_get_inode);
1115}
1116
1117static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1118					int fh_len, int fh_type)
1119{
1120	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1121				    ext4_nfs_get_inode);
1122}
1123
1124/*
1125 * Try to release metadata pages (indirect blocks, directories) which are
1126 * mapped via the block device.  Since these pages could have journal heads
1127 * which would prevent try_to_free_buffers() from freeing them, we must use
1128 * jbd2 layer's try_to_free_buffers() function to release them.
1129 */
1130static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1131				 gfp_t wait)
1132{
1133	journal_t *journal = EXT4_SB(sb)->s_journal;
1134
1135	WARN_ON(PageChecked(page));
1136	if (!page_has_buffers(page))
1137		return 0;
1138	if (journal)
1139		return jbd2_journal_try_to_free_buffers(journal, page,
1140						wait & ~__GFP_DIRECT_RECLAIM);
1141	return try_to_free_buffers(page);
1142}
1143
1144#ifdef CONFIG_EXT4_FS_ENCRYPTION
1145static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1146{
1147	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1148				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1149}
1150
1151static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1152							void *fs_data)
1153{
1154	handle_t *handle = fs_data;
1155	int res, res2, credits, retries = 0;
1156
1157	/*
1158	 * Encrypting the root directory is not allowed because e2fsck expects
1159	 * lost+found to exist and be unencrypted, and encrypting the root
1160	 * directory would imply encrypting the lost+found directory as well as
1161	 * the filename "lost+found" itself.
1162	 */
1163	if (inode->i_ino == EXT4_ROOT_INO)
1164		return -EPERM;
1165
1166	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1167		return -EINVAL;
1168
1169	res = ext4_convert_inline_data(inode);
1170	if (res)
1171		return res;
1172
1173	/*
1174	 * If a journal handle was specified, then the encryption context is
1175	 * being set on a new inode via inheritance and is part of a larger
1176	 * transaction to create the inode.  Otherwise the encryption context is
1177	 * being set on an existing inode in its own transaction.  Only in the
1178	 * latter case should the "retry on ENOSPC" logic be used.
1179	 */
1180
1181	if (handle) {
1182		res = ext4_xattr_set_handle(handle, inode,
1183					    EXT4_XATTR_INDEX_ENCRYPTION,
1184					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1185					    ctx, len, 0);
1186		if (!res) {
1187			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1188			ext4_clear_inode_state(inode,
1189					EXT4_STATE_MAY_INLINE_DATA);
1190			/*
1191			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1192			 * S_DAX may be disabled
1193			 */
1194			ext4_set_inode_flags(inode);
1195		}
1196		return res;
1197	}
1198
1199	res = dquot_initialize(inode);
1200	if (res)
1201		return res;
1202retry:
1203	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1204				     &credits);
1205	if (res)
1206		return res;
1207
1208	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1209	if (IS_ERR(handle))
1210		return PTR_ERR(handle);
1211
1212	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1213				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1214				    ctx, len, 0);
1215	if (!res) {
1216		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1217		/*
1218		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1219		 * S_DAX may be disabled
1220		 */
1221		ext4_set_inode_flags(inode);
1222		res = ext4_mark_inode_dirty(handle, inode);
1223		if (res)
1224			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1225	}
1226	res2 = ext4_journal_stop(handle);
1227
1228	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1229		goto retry;
1230	if (!res)
1231		res = res2;
1232	return res;
1233}
1234
1235static bool ext4_dummy_context(struct inode *inode)
1236{
1237	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1238}
1239
1240static unsigned ext4_max_namelen(struct inode *inode)
1241{
1242	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1243		EXT4_NAME_LEN;
1244}
1245
1246static const struct fscrypt_operations ext4_cryptops = {
1247	.key_prefix		= "ext4:",
1248	.get_context		= ext4_get_context,
1249	.set_context		= ext4_set_context,
1250	.dummy_context		= ext4_dummy_context,
1251	.empty_dir		= ext4_empty_dir,
1252	.max_namelen		= ext4_max_namelen,
1253};
1254#endif
1255
1256#ifdef CONFIG_QUOTA
1257static const char * const quotatypes[] = INITQFNAMES;
1258#define QTYPE2NAME(t) (quotatypes[t])
1259
1260static int ext4_write_dquot(struct dquot *dquot);
1261static int ext4_acquire_dquot(struct dquot *dquot);
1262static int ext4_release_dquot(struct dquot *dquot);
1263static int ext4_mark_dquot_dirty(struct dquot *dquot);
1264static int ext4_write_info(struct super_block *sb, int type);
1265static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1266			 const struct path *path);
 
1267static int ext4_quota_on_mount(struct super_block *sb, int type);
1268static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1269			       size_t len, loff_t off);
1270static ssize_t ext4_quota_write(struct super_block *sb, int type,
1271				const char *data, size_t len, loff_t off);
1272static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1273			     unsigned int flags);
1274static int ext4_enable_quotas(struct super_block *sb);
1275static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1276
1277static struct dquot **ext4_get_dquots(struct inode *inode)
1278{
1279	return EXT4_I(inode)->i_dquot;
1280}
1281
1282static const struct dquot_operations ext4_quota_operations = {
1283	.get_reserved_space	= ext4_get_reserved_space,
1284	.write_dquot		= ext4_write_dquot,
1285	.acquire_dquot		= ext4_acquire_dquot,
1286	.release_dquot		= ext4_release_dquot,
1287	.mark_dirty		= ext4_mark_dquot_dirty,
1288	.write_info		= ext4_write_info,
1289	.alloc_dquot		= dquot_alloc,
1290	.destroy_dquot		= dquot_destroy,
1291	.get_projid		= ext4_get_projid,
1292	.get_inode_usage	= ext4_get_inode_usage,
1293	.get_next_id		= ext4_get_next_id,
1294};
1295
1296static const struct quotactl_ops ext4_qctl_operations = {
1297	.quota_on	= ext4_quota_on,
1298	.quota_off	= ext4_quota_off,
1299	.quota_sync	= dquot_quota_sync,
1300	.get_state	= dquot_get_state,
1301	.set_info	= dquot_set_dqinfo,
1302	.get_dqblk	= dquot_get_dqblk,
1303	.set_dqblk	= dquot_set_dqblk,
1304	.get_nextdqblk	= dquot_get_next_dqblk,
1305};
1306#endif
1307
1308static const struct super_operations ext4_sops = {
1309	.alloc_inode	= ext4_alloc_inode,
1310	.destroy_inode	= ext4_destroy_inode,
1311	.write_inode	= ext4_write_inode,
1312	.dirty_inode	= ext4_dirty_inode,
1313	.drop_inode	= ext4_drop_inode,
1314	.evict_inode	= ext4_evict_inode,
1315	.put_super	= ext4_put_super,
1316	.sync_fs	= ext4_sync_fs,
1317	.freeze_fs	= ext4_freeze,
1318	.unfreeze_fs	= ext4_unfreeze,
1319	.statfs		= ext4_statfs,
1320	.remount_fs	= ext4_remount,
1321	.show_options	= ext4_show_options,
1322#ifdef CONFIG_QUOTA
1323	.quota_read	= ext4_quota_read,
1324	.quota_write	= ext4_quota_write,
1325	.get_dquots	= ext4_get_dquots,
1326#endif
1327	.bdev_try_to_free_page = bdev_try_to_free_page,
1328};
1329
1330static const struct export_operations ext4_export_ops = {
1331	.fh_to_dentry = ext4_fh_to_dentry,
1332	.fh_to_parent = ext4_fh_to_parent,
1333	.get_parent = ext4_get_parent,
1334};
1335
1336enum {
1337	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1338	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1339	Opt_nouid32, Opt_debug, Opt_removed,
1340	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1341	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1342	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1343	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1344	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1345	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1346	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1347	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1348	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1349	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1350	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1351	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1352	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1353	Opt_inode_readahead_blks, Opt_journal_ioprio,
1354	Opt_dioread_nolock, Opt_dioread_lock,
1355	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1356	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1357};
1358
1359static const match_table_t tokens = {
1360	{Opt_bsd_df, "bsddf"},
1361	{Opt_minix_df, "minixdf"},
1362	{Opt_grpid, "grpid"},
1363	{Opt_grpid, "bsdgroups"},
1364	{Opt_nogrpid, "nogrpid"},
1365	{Opt_nogrpid, "sysvgroups"},
1366	{Opt_resgid, "resgid=%u"},
1367	{Opt_resuid, "resuid=%u"},
1368	{Opt_sb, "sb=%u"},
1369	{Opt_err_cont, "errors=continue"},
1370	{Opt_err_panic, "errors=panic"},
1371	{Opt_err_ro, "errors=remount-ro"},
1372	{Opt_nouid32, "nouid32"},
1373	{Opt_debug, "debug"},
1374	{Opt_removed, "oldalloc"},
1375	{Opt_removed, "orlov"},
1376	{Opt_user_xattr, "user_xattr"},
1377	{Opt_nouser_xattr, "nouser_xattr"},
1378	{Opt_acl, "acl"},
1379	{Opt_noacl, "noacl"},
1380	{Opt_noload, "norecovery"},
1381	{Opt_noload, "noload"},
1382	{Opt_removed, "nobh"},
1383	{Opt_removed, "bh"},
1384	{Opt_commit, "commit=%u"},
1385	{Opt_min_batch_time, "min_batch_time=%u"},
1386	{Opt_max_batch_time, "max_batch_time=%u"},
1387	{Opt_journal_dev, "journal_dev=%u"},
1388	{Opt_journal_path, "journal_path=%s"},
1389	{Opt_journal_checksum, "journal_checksum"},
1390	{Opt_nojournal_checksum, "nojournal_checksum"},
1391	{Opt_journal_async_commit, "journal_async_commit"},
1392	{Opt_abort, "abort"},
1393	{Opt_data_journal, "data=journal"},
1394	{Opt_data_ordered, "data=ordered"},
1395	{Opt_data_writeback, "data=writeback"},
1396	{Opt_data_err_abort, "data_err=abort"},
1397	{Opt_data_err_ignore, "data_err=ignore"},
1398	{Opt_offusrjquota, "usrjquota="},
1399	{Opt_usrjquota, "usrjquota=%s"},
1400	{Opt_offgrpjquota, "grpjquota="},
1401	{Opt_grpjquota, "grpjquota=%s"},
1402	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1403	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1404	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1405	{Opt_grpquota, "grpquota"},
1406	{Opt_noquota, "noquota"},
1407	{Opt_quota, "quota"},
1408	{Opt_usrquota, "usrquota"},
1409	{Opt_prjquota, "prjquota"},
1410	{Opt_barrier, "barrier=%u"},
1411	{Opt_barrier, "barrier"},
1412	{Opt_nobarrier, "nobarrier"},
1413	{Opt_i_version, "i_version"},
1414	{Opt_dax, "dax"},
1415	{Opt_stripe, "stripe=%u"},
1416	{Opt_delalloc, "delalloc"},
1417	{Opt_lazytime, "lazytime"},
1418	{Opt_nolazytime, "nolazytime"},
1419	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1420	{Opt_nodelalloc, "nodelalloc"},
1421	{Opt_removed, "mblk_io_submit"},
1422	{Opt_removed, "nomblk_io_submit"},
1423	{Opt_block_validity, "block_validity"},
1424	{Opt_noblock_validity, "noblock_validity"},
1425	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1426	{Opt_journal_ioprio, "journal_ioprio=%u"},
1427	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1428	{Opt_auto_da_alloc, "auto_da_alloc"},
1429	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1430	{Opt_dioread_nolock, "dioread_nolock"},
1431	{Opt_dioread_lock, "dioread_lock"},
1432	{Opt_discard, "discard"},
1433	{Opt_nodiscard, "nodiscard"},
1434	{Opt_init_itable, "init_itable=%u"},
1435	{Opt_init_itable, "init_itable"},
1436	{Opt_noinit_itable, "noinit_itable"},
1437	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1438	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1439	{Opt_nombcache, "nombcache"},
1440	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1441	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1442	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1443	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1444	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1445	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1446	{Opt_err, NULL},
1447};
1448
1449static ext4_fsblk_t get_sb_block(void **data)
1450{
1451	ext4_fsblk_t	sb_block;
1452	char		*options = (char *) *data;
1453
1454	if (!options || strncmp(options, "sb=", 3) != 0)
1455		return 1;	/* Default location */
1456
1457	options += 3;
1458	/* TODO: use simple_strtoll with >32bit ext4 */
1459	sb_block = simple_strtoul(options, &options, 0);
1460	if (*options && *options != ',') {
1461		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1462		       (char *) *data);
1463		return 1;
1464	}
1465	if (*options == ',')
1466		options++;
1467	*data = (void *) options;
1468
1469	return sb_block;
1470}
1471
1472#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1473static const char deprecated_msg[] =
1474	"Mount option \"%s\" will be removed by %s\n"
1475	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1476
1477#ifdef CONFIG_QUOTA
1478static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1479{
1480	struct ext4_sb_info *sbi = EXT4_SB(sb);
1481	char *qname;
1482	int ret = -1;
1483
1484	if (sb_any_quota_loaded(sb) &&
1485		!sbi->s_qf_names[qtype]) {
1486		ext4_msg(sb, KERN_ERR,
1487			"Cannot change journaled "
1488			"quota options when quota turned on");
1489		return -1;
1490	}
1491	if (ext4_has_feature_quota(sb)) {
1492		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1493			 "ignored when QUOTA feature is enabled");
1494		return 1;
1495	}
1496	qname = match_strdup(args);
1497	if (!qname) {
1498		ext4_msg(sb, KERN_ERR,
1499			"Not enough memory for storing quotafile name");
1500		return -1;
1501	}
1502	if (sbi->s_qf_names[qtype]) {
1503		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1504			ret = 1;
1505		else
1506			ext4_msg(sb, KERN_ERR,
1507				 "%s quota file already specified",
1508				 QTYPE2NAME(qtype));
1509		goto errout;
1510	}
1511	if (strchr(qname, '/')) {
1512		ext4_msg(sb, KERN_ERR,
1513			"quotafile must be on filesystem root");
1514		goto errout;
1515	}
1516	sbi->s_qf_names[qtype] = qname;
1517	set_opt(sb, QUOTA);
1518	return 1;
1519errout:
1520	kfree(qname);
1521	return ret;
1522}
1523
1524static int clear_qf_name(struct super_block *sb, int qtype)
1525{
1526
1527	struct ext4_sb_info *sbi = EXT4_SB(sb);
1528
1529	if (sb_any_quota_loaded(sb) &&
1530		sbi->s_qf_names[qtype]) {
1531		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1532			" when quota turned on");
1533		return -1;
1534	}
1535	kfree(sbi->s_qf_names[qtype]);
1536	sbi->s_qf_names[qtype] = NULL;
1537	return 1;
1538}
1539#endif
1540
1541#define MOPT_SET	0x0001
1542#define MOPT_CLEAR	0x0002
1543#define MOPT_NOSUPPORT	0x0004
1544#define MOPT_EXPLICIT	0x0008
1545#define MOPT_CLEAR_ERR	0x0010
1546#define MOPT_GTE0	0x0020
1547#ifdef CONFIG_QUOTA
1548#define MOPT_Q		0
1549#define MOPT_QFMT	0x0040
1550#else
1551#define MOPT_Q		MOPT_NOSUPPORT
1552#define MOPT_QFMT	MOPT_NOSUPPORT
1553#endif
1554#define MOPT_DATAJ	0x0080
1555#define MOPT_NO_EXT2	0x0100
1556#define MOPT_NO_EXT3	0x0200
1557#define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1558#define MOPT_STRING	0x0400
1559
1560static const struct mount_opts {
1561	int	token;
1562	int	mount_opt;
1563	int	flags;
1564} ext4_mount_opts[] = {
1565	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1566	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1567	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1568	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1569	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1570	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1571	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1572	 MOPT_EXT4_ONLY | MOPT_SET},
1573	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1574	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1575	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1576	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1577	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1578	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1579	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1580	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1581	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1582	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1583	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1584	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1585	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1586				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1587	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1588	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1589	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1590	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1591	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1592	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1593	 MOPT_NO_EXT2},
1594	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1595	 MOPT_NO_EXT2},
1596	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1597	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1598	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1599	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1600	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1601	{Opt_commit, 0, MOPT_GTE0},
1602	{Opt_max_batch_time, 0, MOPT_GTE0},
1603	{Opt_min_batch_time, 0, MOPT_GTE0},
1604	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1605	{Opt_init_itable, 0, MOPT_GTE0},
1606	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1607	{Opt_stripe, 0, MOPT_GTE0},
1608	{Opt_resuid, 0, MOPT_GTE0},
1609	{Opt_resgid, 0, MOPT_GTE0},
1610	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1611	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1612	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1613	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1614	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1615	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1616	 MOPT_NO_EXT2 | MOPT_DATAJ},
1617	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1618	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1619#ifdef CONFIG_EXT4_FS_POSIX_ACL
1620	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1621	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1622#else
1623	{Opt_acl, 0, MOPT_NOSUPPORT},
1624	{Opt_noacl, 0, MOPT_NOSUPPORT},
1625#endif
1626	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1627	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1628	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1629	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1630	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1631							MOPT_SET | MOPT_Q},
1632	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1633							MOPT_SET | MOPT_Q},
1634	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1635							MOPT_SET | MOPT_Q},
1636	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1637		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1638							MOPT_CLEAR | MOPT_Q},
1639	{Opt_usrjquota, 0, MOPT_Q},
1640	{Opt_grpjquota, 0, MOPT_Q},
1641	{Opt_offusrjquota, 0, MOPT_Q},
1642	{Opt_offgrpjquota, 0, MOPT_Q},
1643	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1644	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1645	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1646	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1647	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1648	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1649	{Opt_err, 0, 0}
1650};
1651
1652static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1653			    substring_t *args, unsigned long *journal_devnum,
1654			    unsigned int *journal_ioprio, int is_remount)
1655{
1656	struct ext4_sb_info *sbi = EXT4_SB(sb);
1657	const struct mount_opts *m;
1658	kuid_t uid;
1659	kgid_t gid;
1660	int arg = 0;
1661
1662#ifdef CONFIG_QUOTA
1663	if (token == Opt_usrjquota)
1664		return set_qf_name(sb, USRQUOTA, &args[0]);
1665	else if (token == Opt_grpjquota)
1666		return set_qf_name(sb, GRPQUOTA, &args[0]);
1667	else if (token == Opt_offusrjquota)
1668		return clear_qf_name(sb, USRQUOTA);
1669	else if (token == Opt_offgrpjquota)
1670		return clear_qf_name(sb, GRPQUOTA);
1671#endif
1672	switch (token) {
1673	case Opt_noacl:
1674	case Opt_nouser_xattr:
1675		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1676		break;
1677	case Opt_sb:
1678		return 1;	/* handled by get_sb_block() */
1679	case Opt_removed:
1680		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1681		return 1;
1682	case Opt_abort:
1683		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1684		return 1;
1685	case Opt_i_version:
1686		sb->s_flags |= SB_I_VERSION;
1687		return 1;
1688	case Opt_lazytime:
1689		sb->s_flags |= SB_LAZYTIME;
1690		return 1;
1691	case Opt_nolazytime:
1692		sb->s_flags &= ~SB_LAZYTIME;
1693		return 1;
1694	}
1695
1696	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1697		if (token == m->token)
1698			break;
1699
1700	if (m->token == Opt_err) {
1701		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1702			 "or missing value", opt);
1703		return -1;
1704	}
1705
1706	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1707		ext4_msg(sb, KERN_ERR,
1708			 "Mount option \"%s\" incompatible with ext2", opt);
1709		return -1;
1710	}
1711	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1712		ext4_msg(sb, KERN_ERR,
1713			 "Mount option \"%s\" incompatible with ext3", opt);
1714		return -1;
1715	}
1716
1717	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1718		return -1;
1719	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1720		return -1;
1721	if (m->flags & MOPT_EXPLICIT) {
1722		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1723			set_opt2(sb, EXPLICIT_DELALLOC);
1724		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1725			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1726		} else
1727			return -1;
1728	}
1729	if (m->flags & MOPT_CLEAR_ERR)
1730		clear_opt(sb, ERRORS_MASK);
1731	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1732		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1733			 "options when quota turned on");
1734		return -1;
1735	}
1736
1737	if (m->flags & MOPT_NOSUPPORT) {
1738		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1739	} else if (token == Opt_commit) {
1740		if (arg == 0)
1741			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1742		sbi->s_commit_interval = HZ * arg;
1743	} else if (token == Opt_debug_want_extra_isize) {
1744		sbi->s_want_extra_isize = arg;
1745	} else if (token == Opt_max_batch_time) {
1746		sbi->s_max_batch_time = arg;
1747	} else if (token == Opt_min_batch_time) {
1748		sbi->s_min_batch_time = arg;
1749	} else if (token == Opt_inode_readahead_blks) {
1750		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1751			ext4_msg(sb, KERN_ERR,
1752				 "EXT4-fs: inode_readahead_blks must be "
1753				 "0 or a power of 2 smaller than 2^31");
1754			return -1;
1755		}
1756		sbi->s_inode_readahead_blks = arg;
1757	} else if (token == Opt_init_itable) {
1758		set_opt(sb, INIT_INODE_TABLE);
1759		if (!args->from)
1760			arg = EXT4_DEF_LI_WAIT_MULT;
1761		sbi->s_li_wait_mult = arg;
1762	} else if (token == Opt_max_dir_size_kb) {
1763		sbi->s_max_dir_size_kb = arg;
1764	} else if (token == Opt_stripe) {
1765		sbi->s_stripe = arg;
1766	} else if (token == Opt_resuid) {
1767		uid = make_kuid(current_user_ns(), arg);
1768		if (!uid_valid(uid)) {
1769			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1770			return -1;
1771		}
1772		sbi->s_resuid = uid;
1773	} else if (token == Opt_resgid) {
1774		gid = make_kgid(current_user_ns(), arg);
1775		if (!gid_valid(gid)) {
1776			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1777			return -1;
1778		}
1779		sbi->s_resgid = gid;
1780	} else if (token == Opt_journal_dev) {
1781		if (is_remount) {
1782			ext4_msg(sb, KERN_ERR,
1783				 "Cannot specify journal on remount");
1784			return -1;
1785		}
1786		*journal_devnum = arg;
1787	} else if (token == Opt_journal_path) {
1788		char *journal_path;
1789		struct inode *journal_inode;
1790		struct path path;
1791		int error;
1792
1793		if (is_remount) {
1794			ext4_msg(sb, KERN_ERR,
1795				 "Cannot specify journal on remount");
1796			return -1;
1797		}
1798		journal_path = match_strdup(&args[0]);
1799		if (!journal_path) {
1800			ext4_msg(sb, KERN_ERR, "error: could not dup "
1801				"journal device string");
1802			return -1;
1803		}
1804
1805		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1806		if (error) {
1807			ext4_msg(sb, KERN_ERR, "error: could not find "
1808				"journal device path: error %d", error);
1809			kfree(journal_path);
1810			return -1;
1811		}
1812
1813		journal_inode = d_inode(path.dentry);
1814		if (!S_ISBLK(journal_inode->i_mode)) {
1815			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1816				"is not a block device", journal_path);
1817			path_put(&path);
1818			kfree(journal_path);
1819			return -1;
1820		}
1821
1822		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1823		path_put(&path);
1824		kfree(journal_path);
1825	} else if (token == Opt_journal_ioprio) {
1826		if (arg > 7) {
1827			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1828				 " (must be 0-7)");
1829			return -1;
1830		}
1831		*journal_ioprio =
1832			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1833	} else if (token == Opt_test_dummy_encryption) {
1834#ifdef CONFIG_EXT4_FS_ENCRYPTION
1835		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1836		ext4_msg(sb, KERN_WARNING,
1837			 "Test dummy encryption mode enabled");
1838#else
1839		ext4_msg(sb, KERN_WARNING,
1840			 "Test dummy encryption mount option ignored");
1841#endif
1842	} else if (m->flags & MOPT_DATAJ) {
1843		if (is_remount) {
1844			if (!sbi->s_journal)
1845				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1846			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1847				ext4_msg(sb, KERN_ERR,
1848					 "Cannot change data mode on remount");
1849				return -1;
1850			}
1851		} else {
1852			clear_opt(sb, DATA_FLAGS);
1853			sbi->s_mount_opt |= m->mount_opt;
1854		}
1855#ifdef CONFIG_QUOTA
1856	} else if (m->flags & MOPT_QFMT) {
1857		if (sb_any_quota_loaded(sb) &&
1858		    sbi->s_jquota_fmt != m->mount_opt) {
1859			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1860				 "quota options when quota turned on");
1861			return -1;
1862		}
1863		if (ext4_has_feature_quota(sb)) {
1864			ext4_msg(sb, KERN_INFO,
1865				 "Quota format mount options ignored "
1866				 "when QUOTA feature is enabled");
1867			return 1;
1868		}
1869		sbi->s_jquota_fmt = m->mount_opt;
1870#endif
1871	} else if (token == Opt_dax) {
1872#ifdef CONFIG_FS_DAX
1873		ext4_msg(sb, KERN_WARNING,
1874		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1875			sbi->s_mount_opt |= m->mount_opt;
1876#else
1877		ext4_msg(sb, KERN_INFO, "dax option not supported");
1878		return -1;
1879#endif
1880	} else if (token == Opt_data_err_abort) {
1881		sbi->s_mount_opt |= m->mount_opt;
1882	} else if (token == Opt_data_err_ignore) {
1883		sbi->s_mount_opt &= ~m->mount_opt;
1884	} else {
1885		if (!args->from)
1886			arg = 1;
1887		if (m->flags & MOPT_CLEAR)
1888			arg = !arg;
1889		else if (unlikely(!(m->flags & MOPT_SET))) {
1890			ext4_msg(sb, KERN_WARNING,
1891				 "buggy handling of option %s", opt);
1892			WARN_ON(1);
1893			return -1;
1894		}
1895		if (arg != 0)
1896			sbi->s_mount_opt |= m->mount_opt;
1897		else
1898			sbi->s_mount_opt &= ~m->mount_opt;
1899	}
1900	return 1;
1901}
1902
1903static int parse_options(char *options, struct super_block *sb,
1904			 unsigned long *journal_devnum,
1905			 unsigned int *journal_ioprio,
1906			 int is_remount)
1907{
1908	struct ext4_sb_info *sbi = EXT4_SB(sb);
1909	char *p;
1910	substring_t args[MAX_OPT_ARGS];
1911	int token;
1912
1913	if (!options)
1914		return 1;
1915
1916	while ((p = strsep(&options, ",")) != NULL) {
1917		if (!*p)
1918			continue;
1919		/*
1920		 * Initialize args struct so we know whether arg was
1921		 * found; some options take optional arguments.
1922		 */
1923		args[0].to = args[0].from = NULL;
1924		token = match_token(p, tokens, args);
1925		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1926				     journal_ioprio, is_remount) < 0)
1927			return 0;
1928	}
1929#ifdef CONFIG_QUOTA
1930	/*
1931	 * We do the test below only for project quotas. 'usrquota' and
1932	 * 'grpquota' mount options are allowed even without quota feature
1933	 * to support legacy quotas in quota files.
1934	 */
1935	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1936		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1937			 "Cannot enable project quota enforcement.");
1938		return 0;
1939	}
1940	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1941		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1942			clear_opt(sb, USRQUOTA);
1943
1944		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1945			clear_opt(sb, GRPQUOTA);
1946
1947		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1948			ext4_msg(sb, KERN_ERR, "old and new quota "
1949					"format mixing");
1950			return 0;
1951		}
1952
1953		if (!sbi->s_jquota_fmt) {
1954			ext4_msg(sb, KERN_ERR, "journaled quota format "
1955					"not specified");
1956			return 0;
1957		}
1958	}
1959#endif
1960	if (test_opt(sb, DIOREAD_NOLOCK)) {
1961		int blocksize =
1962			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1963
1964		if (blocksize < PAGE_SIZE) {
1965			ext4_msg(sb, KERN_ERR, "can't mount with "
1966				 "dioread_nolock if block size != PAGE_SIZE");
1967			return 0;
1968		}
1969	}
 
 
 
 
 
 
1970	return 1;
1971}
1972
1973static inline void ext4_show_quota_options(struct seq_file *seq,
1974					   struct super_block *sb)
1975{
1976#if defined(CONFIG_QUOTA)
1977	struct ext4_sb_info *sbi = EXT4_SB(sb);
1978
1979	if (sbi->s_jquota_fmt) {
1980		char *fmtname = "";
1981
1982		switch (sbi->s_jquota_fmt) {
1983		case QFMT_VFS_OLD:
1984			fmtname = "vfsold";
1985			break;
1986		case QFMT_VFS_V0:
1987			fmtname = "vfsv0";
1988			break;
1989		case QFMT_VFS_V1:
1990			fmtname = "vfsv1";
1991			break;
1992		}
1993		seq_printf(seq, ",jqfmt=%s", fmtname);
1994	}
1995
1996	if (sbi->s_qf_names[USRQUOTA])
1997		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1998
1999	if (sbi->s_qf_names[GRPQUOTA])
2000		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
2001#endif
2002}
2003
2004static const char *token2str(int token)
2005{
2006	const struct match_token *t;
2007
2008	for (t = tokens; t->token != Opt_err; t++)
2009		if (t->token == token && !strchr(t->pattern, '='))
2010			break;
2011	return t->pattern;
2012}
2013
2014/*
2015 * Show an option if
2016 *  - it's set to a non-default value OR
2017 *  - if the per-sb default is different from the global default
2018 */
2019static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2020			      int nodefs)
2021{
2022	struct ext4_sb_info *sbi = EXT4_SB(sb);
2023	struct ext4_super_block *es = sbi->s_es;
2024	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2025	const struct mount_opts *m;
2026	char sep = nodefs ? '\n' : ',';
2027
2028#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2029#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2030
2031	if (sbi->s_sb_block != 1)
2032		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2033
2034	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2035		int want_set = m->flags & MOPT_SET;
2036		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2037		    (m->flags & MOPT_CLEAR_ERR))
2038			continue;
2039		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2040			continue; /* skip if same as the default */
2041		if ((want_set &&
2042		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2043		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2044			continue; /* select Opt_noFoo vs Opt_Foo */
2045		SEQ_OPTS_PRINT("%s", token2str(m->token));
2046	}
2047
2048	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2049	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2050		SEQ_OPTS_PRINT("resuid=%u",
2051				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2052	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2053	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2054		SEQ_OPTS_PRINT("resgid=%u",
2055				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2056	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2057	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2058		SEQ_OPTS_PUTS("errors=remount-ro");
2059	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2060		SEQ_OPTS_PUTS("errors=continue");
2061	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2062		SEQ_OPTS_PUTS("errors=panic");
2063	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2064		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2065	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2066		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2067	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2068		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2069	if (sb->s_flags & SB_I_VERSION)
2070		SEQ_OPTS_PUTS("i_version");
2071	if (nodefs || sbi->s_stripe)
2072		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2073	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2074			(sbi->s_mount_opt ^ def_mount_opt)) {
2075		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2076			SEQ_OPTS_PUTS("data=journal");
2077		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2078			SEQ_OPTS_PUTS("data=ordered");
2079		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2080			SEQ_OPTS_PUTS("data=writeback");
2081	}
2082	if (nodefs ||
2083	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2084		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2085			       sbi->s_inode_readahead_blks);
2086
2087	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2088		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2089		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2090	if (nodefs || sbi->s_max_dir_size_kb)
2091		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2092	if (test_opt(sb, DATA_ERR_ABORT))
2093		SEQ_OPTS_PUTS("data_err=abort");
2094
2095	ext4_show_quota_options(seq, sb);
2096	return 0;
2097}
2098
2099static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2100{
2101	return _ext4_show_options(seq, root->d_sb, 0);
2102}
2103
2104int ext4_seq_options_show(struct seq_file *seq, void *offset)
2105{
2106	struct super_block *sb = seq->private;
2107	int rc;
2108
2109	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2110	rc = _ext4_show_options(seq, sb, 1);
2111	seq_puts(seq, "\n");
2112	return rc;
2113}
2114
2115static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2116			    int read_only)
2117{
2118	struct ext4_sb_info *sbi = EXT4_SB(sb);
2119	int res = 0;
2120
2121	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2122		ext4_msg(sb, KERN_ERR, "revision level too high, "
2123			 "forcing read-only mode");
2124		res = SB_RDONLY;
2125	}
2126	if (read_only)
2127		goto done;
2128	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2129		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2130			 "running e2fsck is recommended");
2131	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2132		ext4_msg(sb, KERN_WARNING,
2133			 "warning: mounting fs with errors, "
2134			 "running e2fsck is recommended");
2135	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2136		 le16_to_cpu(es->s_mnt_count) >=
2137		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2138		ext4_msg(sb, KERN_WARNING,
2139			 "warning: maximal mount count reached, "
2140			 "running e2fsck is recommended");
2141	else if (le32_to_cpu(es->s_checkinterval) &&
2142		(le32_to_cpu(es->s_lastcheck) +
2143			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2144		ext4_msg(sb, KERN_WARNING,
2145			 "warning: checktime reached, "
2146			 "running e2fsck is recommended");
2147	if (!sbi->s_journal)
2148		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2149	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2150		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2151	le16_add_cpu(&es->s_mnt_count, 1);
2152	es->s_mtime = cpu_to_le32(get_seconds());
2153	ext4_update_dynamic_rev(sb);
2154	if (sbi->s_journal)
2155		ext4_set_feature_journal_needs_recovery(sb);
2156
2157	ext4_commit_super(sb, 1);
2158done:
2159	if (test_opt(sb, DEBUG))
2160		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2161				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2162			sb->s_blocksize,
2163			sbi->s_groups_count,
2164			EXT4_BLOCKS_PER_GROUP(sb),
2165			EXT4_INODES_PER_GROUP(sb),
2166			sbi->s_mount_opt, sbi->s_mount_opt2);
2167
2168	cleancache_init_fs(sb);
2169	return res;
2170}
2171
2172int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2173{
2174	struct ext4_sb_info *sbi = EXT4_SB(sb);
2175	struct flex_groups *new_groups;
2176	int size;
2177
2178	if (!sbi->s_log_groups_per_flex)
2179		return 0;
2180
2181	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2182	if (size <= sbi->s_flex_groups_allocated)
2183		return 0;
2184
2185	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2186	new_groups = kvzalloc(size, GFP_KERNEL);
2187	if (!new_groups) {
2188		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2189			 size / (int) sizeof(struct flex_groups));
2190		return -ENOMEM;
2191	}
2192
2193	if (sbi->s_flex_groups) {
2194		memcpy(new_groups, sbi->s_flex_groups,
2195		       (sbi->s_flex_groups_allocated *
2196			sizeof(struct flex_groups)));
2197		kvfree(sbi->s_flex_groups);
2198	}
2199	sbi->s_flex_groups = new_groups;
2200	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2201	return 0;
2202}
2203
2204static int ext4_fill_flex_info(struct super_block *sb)
2205{
2206	struct ext4_sb_info *sbi = EXT4_SB(sb);
2207	struct ext4_group_desc *gdp = NULL;
2208	ext4_group_t flex_group;
2209	int i, err;
2210
2211	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2212	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2213		sbi->s_log_groups_per_flex = 0;
2214		return 1;
2215	}
2216
2217	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2218	if (err)
2219		goto failed;
2220
2221	for (i = 0; i < sbi->s_groups_count; i++) {
2222		gdp = ext4_get_group_desc(sb, i, NULL);
2223
2224		flex_group = ext4_flex_group(sbi, i);
2225		atomic_add(ext4_free_inodes_count(sb, gdp),
2226			   &sbi->s_flex_groups[flex_group].free_inodes);
2227		atomic64_add(ext4_free_group_clusters(sb, gdp),
2228			     &sbi->s_flex_groups[flex_group].free_clusters);
2229		atomic_add(ext4_used_dirs_count(sb, gdp),
2230			   &sbi->s_flex_groups[flex_group].used_dirs);
2231	}
2232
2233	return 1;
2234failed:
2235	return 0;
2236}
2237
2238static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2239				   struct ext4_group_desc *gdp)
2240{
2241	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2242	__u16 crc = 0;
2243	__le32 le_group = cpu_to_le32(block_group);
2244	struct ext4_sb_info *sbi = EXT4_SB(sb);
2245
2246	if (ext4_has_metadata_csum(sbi->s_sb)) {
2247		/* Use new metadata_csum algorithm */
 
2248		__u32 csum32;
2249		__u16 dummy_csum = 0;
2250
 
 
2251		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2252				     sizeof(le_group));
2253		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2254		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2255				     sizeof(dummy_csum));
2256		offset += sizeof(dummy_csum);
2257		if (offset < sbi->s_desc_size)
2258			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2259					     sbi->s_desc_size - offset);
2260
2261		crc = csum32 & 0xFFFF;
2262		goto out;
2263	}
2264
2265	/* old crc16 code */
2266	if (!ext4_has_feature_gdt_csum(sb))
2267		return 0;
2268
 
 
2269	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2270	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2271	crc = crc16(crc, (__u8 *)gdp, offset);
2272	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2273	/* for checksum of struct ext4_group_desc do the rest...*/
2274	if (ext4_has_feature_64bit(sb) &&
2275	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2276		crc = crc16(crc, (__u8 *)gdp + offset,
2277			    le16_to_cpu(sbi->s_es->s_desc_size) -
2278				offset);
2279
2280out:
2281	return cpu_to_le16(crc);
2282}
2283
2284int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2285				struct ext4_group_desc *gdp)
2286{
2287	if (ext4_has_group_desc_csum(sb) &&
2288	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2289		return 0;
2290
2291	return 1;
2292}
2293
2294void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2295			      struct ext4_group_desc *gdp)
2296{
2297	if (!ext4_has_group_desc_csum(sb))
2298		return;
2299	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2300}
2301
2302/* Called at mount-time, super-block is locked */
2303static int ext4_check_descriptors(struct super_block *sb,
2304				  ext4_fsblk_t sb_block,
2305				  ext4_group_t *first_not_zeroed)
2306{
2307	struct ext4_sb_info *sbi = EXT4_SB(sb);
2308	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2309	ext4_fsblk_t last_block;
2310	ext4_fsblk_t block_bitmap;
2311	ext4_fsblk_t inode_bitmap;
2312	ext4_fsblk_t inode_table;
2313	int flexbg_flag = 0;
2314	ext4_group_t i, grp = sbi->s_groups_count;
2315
2316	if (ext4_has_feature_flex_bg(sb))
2317		flexbg_flag = 1;
2318
2319	ext4_debug("Checking group descriptors");
2320
2321	for (i = 0; i < sbi->s_groups_count; i++) {
2322		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2323
2324		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2325			last_block = ext4_blocks_count(sbi->s_es) - 1;
2326		else
2327			last_block = first_block +
2328				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2329
2330		if ((grp == sbi->s_groups_count) &&
2331		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2332			grp = i;
2333
2334		block_bitmap = ext4_block_bitmap(sb, gdp);
2335		if (block_bitmap == sb_block) {
2336			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2337				 "Block bitmap for group %u overlaps "
2338				 "superblock", i);
2339			if (!sb_rdonly(sb))
2340				return 0;
2341		}
2342		if (block_bitmap < first_block || block_bitmap > last_block) {
2343			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2344			       "Block bitmap for group %u not in group "
2345			       "(block %llu)!", i, block_bitmap);
2346			return 0;
2347		}
2348		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2349		if (inode_bitmap == sb_block) {
2350			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2351				 "Inode bitmap for group %u overlaps "
2352				 "superblock", i);
2353			if (!sb_rdonly(sb))
2354				return 0;
2355		}
2356		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2357			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2358			       "Inode bitmap for group %u not in group "
2359			       "(block %llu)!", i, inode_bitmap);
2360			return 0;
2361		}
2362		inode_table = ext4_inode_table(sb, gdp);
2363		if (inode_table == sb_block) {
2364			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2365				 "Inode table for group %u overlaps "
2366				 "superblock", i);
2367			if (!sb_rdonly(sb))
2368				return 0;
2369		}
2370		if (inode_table < first_block ||
2371		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2372			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2373			       "Inode table for group %u not in group "
2374			       "(block %llu)!", i, inode_table);
2375			return 0;
2376		}
2377		ext4_lock_group(sb, i);
2378		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2379			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2380				 "Checksum for group %u failed (%u!=%u)",
2381				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2382				     gdp)), le16_to_cpu(gdp->bg_checksum));
2383			if (!sb_rdonly(sb)) {
2384				ext4_unlock_group(sb, i);
2385				return 0;
2386			}
2387		}
2388		ext4_unlock_group(sb, i);
2389		if (!flexbg_flag)
2390			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2391	}
2392	if (NULL != first_not_zeroed)
2393		*first_not_zeroed = grp;
2394	return 1;
2395}
2396
2397/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2398 * the superblock) which were deleted from all directories, but held open by
2399 * a process at the time of a crash.  We walk the list and try to delete these
2400 * inodes at recovery time (only with a read-write filesystem).
2401 *
2402 * In order to keep the orphan inode chain consistent during traversal (in
2403 * case of crash during recovery), we link each inode into the superblock
2404 * orphan list_head and handle it the same way as an inode deletion during
2405 * normal operation (which journals the operations for us).
2406 *
2407 * We only do an iget() and an iput() on each inode, which is very safe if we
2408 * accidentally point at an in-use or already deleted inode.  The worst that
2409 * can happen in this case is that we get a "bit already cleared" message from
2410 * ext4_free_inode().  The only reason we would point at a wrong inode is if
2411 * e2fsck was run on this filesystem, and it must have already done the orphan
2412 * inode cleanup for us, so we can safely abort without any further action.
2413 */
2414static void ext4_orphan_cleanup(struct super_block *sb,
2415				struct ext4_super_block *es)
2416{
2417	unsigned int s_flags = sb->s_flags;
2418	int ret, nr_orphans = 0, nr_truncates = 0;
2419#ifdef CONFIG_QUOTA
2420	int quota_update = 0;
2421	int i;
2422#endif
2423	if (!es->s_last_orphan) {
2424		jbd_debug(4, "no orphan inodes to clean up\n");
2425		return;
2426	}
2427
2428	if (bdev_read_only(sb->s_bdev)) {
2429		ext4_msg(sb, KERN_ERR, "write access "
2430			"unavailable, skipping orphan cleanup");
2431		return;
2432	}
2433
2434	/* Check if feature set would not allow a r/w mount */
2435	if (!ext4_feature_set_ok(sb, 0)) {
2436		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2437			 "unknown ROCOMPAT features");
2438		return;
2439	}
2440
2441	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2442		/* don't clear list on RO mount w/ errors */
2443		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2444			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2445				  "clearing orphan list.\n");
2446			es->s_last_orphan = 0;
2447		}
2448		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2449		return;
2450	}
2451
2452	if (s_flags & SB_RDONLY) {
2453		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2454		sb->s_flags &= ~SB_RDONLY;
2455	}
2456#ifdef CONFIG_QUOTA
2457	/* Needed for iput() to work correctly and not trash data */
2458	sb->s_flags |= SB_ACTIVE;
2459
2460	/*
2461	 * Turn on quotas which were not enabled for read-only mounts if
2462	 * filesystem has quota feature, so that they are updated correctly.
2463	 */
2464	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2465		int ret = ext4_enable_quotas(sb);
2466
2467		if (!ret)
2468			quota_update = 1;
2469		else
2470			ext4_msg(sb, KERN_ERR,
2471				"Cannot turn on quotas: error %d", ret);
2472	}
2473
2474	/* Turn on journaled quotas used for old sytle */
2475	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2476		if (EXT4_SB(sb)->s_qf_names[i]) {
2477			int ret = ext4_quota_on_mount(sb, i);
2478
2479			if (!ret)
2480				quota_update = 1;
2481			else
2482				ext4_msg(sb, KERN_ERR,
2483					"Cannot turn on journaled "
2484					"quota: type %d: error %d", i, ret);
2485		}
2486	}
2487#endif
2488
2489	while (es->s_last_orphan) {
2490		struct inode *inode;
2491
2492		/*
2493		 * We may have encountered an error during cleanup; if
2494		 * so, skip the rest.
2495		 */
2496		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2497			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2498			es->s_last_orphan = 0;
2499			break;
2500		}
2501
2502		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2503		if (IS_ERR(inode)) {
2504			es->s_last_orphan = 0;
2505			break;
2506		}
2507
2508		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2509		dquot_initialize(inode);
2510		if (inode->i_nlink) {
2511			if (test_opt(sb, DEBUG))
2512				ext4_msg(sb, KERN_DEBUG,
2513					"%s: truncating inode %lu to %lld bytes",
2514					__func__, inode->i_ino, inode->i_size);
2515			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2516				  inode->i_ino, inode->i_size);
2517			inode_lock(inode);
2518			truncate_inode_pages(inode->i_mapping, inode->i_size);
2519			ret = ext4_truncate(inode);
2520			if (ret)
2521				ext4_std_error(inode->i_sb, ret);
2522			inode_unlock(inode);
2523			nr_truncates++;
2524		} else {
2525			if (test_opt(sb, DEBUG))
2526				ext4_msg(sb, KERN_DEBUG,
2527					"%s: deleting unreferenced inode %lu",
2528					__func__, inode->i_ino);
2529			jbd_debug(2, "deleting unreferenced inode %lu\n",
2530				  inode->i_ino);
2531			nr_orphans++;
2532		}
2533		iput(inode);  /* The delete magic happens here! */
2534	}
2535
2536#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2537
2538	if (nr_orphans)
2539		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2540		       PLURAL(nr_orphans));
2541	if (nr_truncates)
2542		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2543		       PLURAL(nr_truncates));
2544#ifdef CONFIG_QUOTA
2545	/* Turn off quotas if they were enabled for orphan cleanup */
2546	if (quota_update) {
2547		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2548			if (sb_dqopt(sb)->files[i])
2549				dquot_quota_off(sb, i);
2550		}
2551	}
2552#endif
2553	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2554}
2555
2556/*
2557 * Maximal extent format file size.
2558 * Resulting logical blkno at s_maxbytes must fit in our on-disk
2559 * extent format containers, within a sector_t, and within i_blocks
2560 * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2561 * so that won't be a limiting factor.
2562 *
2563 * However there is other limiting factor. We do store extents in the form
2564 * of starting block and length, hence the resulting length of the extent
2565 * covering maximum file size must fit into on-disk format containers as
2566 * well. Given that length is always by 1 unit bigger than max unit (because
2567 * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2568 *
2569 * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2570 */
2571static loff_t ext4_max_size(int blkbits, int has_huge_files)
2572{
2573	loff_t res;
2574	loff_t upper_limit = MAX_LFS_FILESIZE;
2575
2576	/* small i_blocks in vfs inode? */
2577	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2578		/*
2579		 * CONFIG_LBDAF is not enabled implies the inode
2580		 * i_block represent total blocks in 512 bytes
2581		 * 32 == size of vfs inode i_blocks * 8
2582		 */
2583		upper_limit = (1LL << 32) - 1;
2584
2585		/* total blocks in file system block size */
2586		upper_limit >>= (blkbits - 9);
2587		upper_limit <<= blkbits;
2588	}
2589
2590	/*
2591	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2592	 * by one fs block, so ee_len can cover the extent of maximum file
2593	 * size
2594	 */
2595	res = (1LL << 32) - 1;
2596	res <<= blkbits;
2597
2598	/* Sanity check against vm- & vfs- imposed limits */
2599	if (res > upper_limit)
2600		res = upper_limit;
2601
2602	return res;
2603}
2604
2605/*
2606 * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2607 * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2608 * We need to be 1 filesystem block less than the 2^48 sector limit.
2609 */
2610static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2611{
2612	loff_t res = EXT4_NDIR_BLOCKS;
2613	int meta_blocks;
2614	loff_t upper_limit;
2615	/* This is calculated to be the largest file size for a dense, block
2616	 * mapped file such that the file's total number of 512-byte sectors,
2617	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2618	 *
2619	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2620	 * number of 512-byte sectors of the file.
2621	 */
2622
2623	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2624		/*
2625		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2626		 * the inode i_block field represents total file blocks in
2627		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2628		 */
2629		upper_limit = (1LL << 32) - 1;
2630
2631		/* total blocks in file system block size */
2632		upper_limit >>= (bits - 9);
2633
2634	} else {
2635		/*
2636		 * We use 48 bit ext4_inode i_blocks
2637		 * With EXT4_HUGE_FILE_FL set the i_blocks
2638		 * represent total number of blocks in
2639		 * file system block size
2640		 */
2641		upper_limit = (1LL << 48) - 1;
2642
2643	}
2644
2645	/* indirect blocks */
2646	meta_blocks = 1;
2647	/* double indirect blocks */
2648	meta_blocks += 1 + (1LL << (bits-2));
2649	/* tripple indirect blocks */
2650	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2651
2652	upper_limit -= meta_blocks;
2653	upper_limit <<= bits;
2654
2655	res += 1LL << (bits-2);
2656	res += 1LL << (2*(bits-2));
2657	res += 1LL << (3*(bits-2));
2658	res <<= bits;
2659	if (res > upper_limit)
2660		res = upper_limit;
2661
2662	if (res > MAX_LFS_FILESIZE)
2663		res = MAX_LFS_FILESIZE;
2664
2665	return res;
2666}
2667
2668static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2669				   ext4_fsblk_t logical_sb_block, int nr)
2670{
2671	struct ext4_sb_info *sbi = EXT4_SB(sb);
2672	ext4_group_t bg, first_meta_bg;
2673	int has_super = 0;
2674
2675	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2676
2677	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2678		return logical_sb_block + nr + 1;
2679	bg = sbi->s_desc_per_block * nr;
2680	if (ext4_bg_has_super(sb, bg))
2681		has_super = 1;
2682
2683	/*
2684	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2685	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2686	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2687	 * compensate.
2688	 */
2689	if (sb->s_blocksize == 1024 && nr == 0 &&
2690	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2691		has_super++;
2692
2693	return (has_super + ext4_group_first_block_no(sb, bg));
2694}
2695
2696/**
2697 * ext4_get_stripe_size: Get the stripe size.
2698 * @sbi: In memory super block info
2699 *
2700 * If we have specified it via mount option, then
2701 * use the mount option value. If the value specified at mount time is
2702 * greater than the blocks per group use the super block value.
2703 * If the super block value is greater than blocks per group return 0.
2704 * Allocator needs it be less than blocks per group.
2705 *
2706 */
2707static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2708{
2709	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2710	unsigned long stripe_width =
2711			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2712	int ret;
2713
2714	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2715		ret = sbi->s_stripe;
2716	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2717		ret = stripe_width;
2718	else if (stride && stride <= sbi->s_blocks_per_group)
2719		ret = stride;
2720	else
2721		ret = 0;
2722
2723	/*
2724	 * If the stripe width is 1, this makes no sense and
2725	 * we set it to 0 to turn off stripe handling code.
2726	 */
2727	if (ret <= 1)
2728		ret = 0;
2729
2730	return ret;
2731}
2732
2733/*
2734 * Check whether this filesystem can be mounted based on
2735 * the features present and the RDONLY/RDWR mount requested.
2736 * Returns 1 if this filesystem can be mounted as requested,
2737 * 0 if it cannot be.
2738 */
2739static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2740{
2741	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2742		ext4_msg(sb, KERN_ERR,
2743			"Couldn't mount because of "
2744			"unsupported optional features (%x)",
2745			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2746			~EXT4_FEATURE_INCOMPAT_SUPP));
2747		return 0;
2748	}
2749
2750	if (readonly)
2751		return 1;
2752
2753	if (ext4_has_feature_readonly(sb)) {
2754		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2755		sb->s_flags |= SB_RDONLY;
2756		return 1;
2757	}
2758
2759	/* Check that feature set is OK for a read-write mount */
2760	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2761		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2762			 "unsupported optional features (%x)",
2763			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2764				~EXT4_FEATURE_RO_COMPAT_SUPP));
2765		return 0;
2766	}
2767	/*
2768	 * Large file size enabled file system can only be mounted
2769	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2770	 */
2771	if (ext4_has_feature_huge_file(sb)) {
2772		if (sizeof(blkcnt_t) < sizeof(u64)) {
2773			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2774				 "cannot be mounted RDWR without "
2775				 "CONFIG_LBDAF");
2776			return 0;
2777		}
2778	}
2779	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2780		ext4_msg(sb, KERN_ERR,
2781			 "Can't support bigalloc feature without "
2782			 "extents feature\n");
2783		return 0;
2784	}
2785
2786#ifndef CONFIG_QUOTA
2787	if (ext4_has_feature_quota(sb) && !readonly) {
2788		ext4_msg(sb, KERN_ERR,
2789			 "Filesystem with quota feature cannot be mounted RDWR "
2790			 "without CONFIG_QUOTA");
2791		return 0;
2792	}
2793	if (ext4_has_feature_project(sb) && !readonly) {
2794		ext4_msg(sb, KERN_ERR,
2795			 "Filesystem with project quota feature cannot be mounted RDWR "
2796			 "without CONFIG_QUOTA");
2797		return 0;
2798	}
2799#endif  /* CONFIG_QUOTA */
2800	return 1;
2801}
2802
2803/*
2804 * This function is called once a day if we have errors logged
2805 * on the file system
2806 */
2807static void print_daily_error_info(struct timer_list *t)
2808{
2809	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2810	struct super_block *sb = sbi->s_sb;
2811	struct ext4_super_block *es = sbi->s_es;
 
 
 
2812
2813	if (es->s_error_count)
2814		/* fsck newer than v1.41.13 is needed to clean this condition. */
2815		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2816			 le32_to_cpu(es->s_error_count));
2817	if (es->s_first_error_time) {
2818		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2819		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2820		       (int) sizeof(es->s_first_error_func),
2821		       es->s_first_error_func,
2822		       le32_to_cpu(es->s_first_error_line));
2823		if (es->s_first_error_ino)
2824			printk(KERN_CONT ": inode %u",
2825			       le32_to_cpu(es->s_first_error_ino));
2826		if (es->s_first_error_block)
2827			printk(KERN_CONT ": block %llu", (unsigned long long)
2828			       le64_to_cpu(es->s_first_error_block));
2829		printk(KERN_CONT "\n");
2830	}
2831	if (es->s_last_error_time) {
2832		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2833		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2834		       (int) sizeof(es->s_last_error_func),
2835		       es->s_last_error_func,
2836		       le32_to_cpu(es->s_last_error_line));
2837		if (es->s_last_error_ino)
2838			printk(KERN_CONT ": inode %u",
2839			       le32_to_cpu(es->s_last_error_ino));
2840		if (es->s_last_error_block)
2841			printk(KERN_CONT ": block %llu", (unsigned long long)
2842			       le64_to_cpu(es->s_last_error_block));
2843		printk(KERN_CONT "\n");
2844	}
2845	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2846}
2847
2848/* Find next suitable group and run ext4_init_inode_table */
2849static int ext4_run_li_request(struct ext4_li_request *elr)
2850{
2851	struct ext4_group_desc *gdp = NULL;
2852	ext4_group_t group, ngroups;
2853	struct super_block *sb;
2854	unsigned long timeout = 0;
2855	int ret = 0;
2856
2857	sb = elr->lr_super;
2858	ngroups = EXT4_SB(sb)->s_groups_count;
2859
 
2860	for (group = elr->lr_next_group; group < ngroups; group++) {
2861		gdp = ext4_get_group_desc(sb, group, NULL);
2862		if (!gdp) {
2863			ret = 1;
2864			break;
2865		}
2866
2867		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2868			break;
2869	}
2870
2871	if (group >= ngroups)
2872		ret = 1;
2873
2874	if (!ret) {
2875		timeout = jiffies;
2876		ret = ext4_init_inode_table(sb, group,
2877					    elr->lr_timeout ? 0 : 1);
2878		if (elr->lr_timeout == 0) {
2879			timeout = (jiffies - timeout) *
2880				  elr->lr_sbi->s_li_wait_mult;
2881			elr->lr_timeout = timeout;
2882		}
2883		elr->lr_next_sched = jiffies + elr->lr_timeout;
2884		elr->lr_next_group = group + 1;
2885	}
 
 
2886	return ret;
2887}
2888
2889/*
2890 * Remove lr_request from the list_request and free the
2891 * request structure. Should be called with li_list_mtx held
2892 */
2893static void ext4_remove_li_request(struct ext4_li_request *elr)
2894{
2895	struct ext4_sb_info *sbi;
2896
2897	if (!elr)
2898		return;
2899
2900	sbi = elr->lr_sbi;
2901
2902	list_del(&elr->lr_request);
2903	sbi->s_li_request = NULL;
2904	kfree(elr);
2905}
2906
2907static void ext4_unregister_li_request(struct super_block *sb)
2908{
2909	mutex_lock(&ext4_li_mtx);
2910	if (!ext4_li_info) {
2911		mutex_unlock(&ext4_li_mtx);
2912		return;
2913	}
2914
2915	mutex_lock(&ext4_li_info->li_list_mtx);
2916	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2917	mutex_unlock(&ext4_li_info->li_list_mtx);
2918	mutex_unlock(&ext4_li_mtx);
2919}
2920
2921static struct task_struct *ext4_lazyinit_task;
2922
2923/*
2924 * This is the function where ext4lazyinit thread lives. It walks
2925 * through the request list searching for next scheduled filesystem.
2926 * When such a fs is found, run the lazy initialization request
2927 * (ext4_rn_li_request) and keep track of the time spend in this
2928 * function. Based on that time we compute next schedule time of
2929 * the request. When walking through the list is complete, compute
2930 * next waking time and put itself into sleep.
2931 */
2932static int ext4_lazyinit_thread(void *arg)
2933{
2934	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2935	struct list_head *pos, *n;
2936	struct ext4_li_request *elr;
2937	unsigned long next_wakeup, cur;
2938
2939	BUG_ON(NULL == eli);
2940
2941cont_thread:
2942	while (true) {
2943		next_wakeup = MAX_JIFFY_OFFSET;
2944
2945		mutex_lock(&eli->li_list_mtx);
2946		if (list_empty(&eli->li_request_list)) {
2947			mutex_unlock(&eli->li_list_mtx);
2948			goto exit_thread;
2949		}
 
2950		list_for_each_safe(pos, n, &eli->li_request_list) {
2951			int err = 0;
2952			int progress = 0;
2953			elr = list_entry(pos, struct ext4_li_request,
2954					 lr_request);
2955
2956			if (time_before(jiffies, elr->lr_next_sched)) {
2957				if (time_before(elr->lr_next_sched, next_wakeup))
2958					next_wakeup = elr->lr_next_sched;
2959				continue;
2960			}
2961			if (down_read_trylock(&elr->lr_super->s_umount)) {
2962				if (sb_start_write_trylock(elr->lr_super)) {
2963					progress = 1;
2964					/*
2965					 * We hold sb->s_umount, sb can not
2966					 * be removed from the list, it is
2967					 * now safe to drop li_list_mtx
2968					 */
2969					mutex_unlock(&eli->li_list_mtx);
2970					err = ext4_run_li_request(elr);
2971					sb_end_write(elr->lr_super);
2972					mutex_lock(&eli->li_list_mtx);
2973					n = pos->next;
2974				}
2975				up_read((&elr->lr_super->s_umount));
2976			}
2977			/* error, remove the lazy_init job */
2978			if (err) {
2979				ext4_remove_li_request(elr);
2980				continue;
2981			}
2982			if (!progress) {
2983				elr->lr_next_sched = jiffies +
2984					(prandom_u32()
2985					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2986			}
 
2987			if (time_before(elr->lr_next_sched, next_wakeup))
2988				next_wakeup = elr->lr_next_sched;
2989		}
2990		mutex_unlock(&eli->li_list_mtx);
2991
2992		try_to_freeze();
2993
2994		cur = jiffies;
2995		if ((time_after_eq(cur, next_wakeup)) ||
2996		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2997			cond_resched();
2998			continue;
2999		}
3000
3001		schedule_timeout_interruptible(next_wakeup - cur);
3002
3003		if (kthread_should_stop()) {
3004			ext4_clear_request_list();
3005			goto exit_thread;
3006		}
3007	}
3008
3009exit_thread:
3010	/*
3011	 * It looks like the request list is empty, but we need
3012	 * to check it under the li_list_mtx lock, to prevent any
3013	 * additions into it, and of course we should lock ext4_li_mtx
3014	 * to atomically free the list and ext4_li_info, because at
3015	 * this point another ext4 filesystem could be registering
3016	 * new one.
3017	 */
3018	mutex_lock(&ext4_li_mtx);
3019	mutex_lock(&eli->li_list_mtx);
3020	if (!list_empty(&eli->li_request_list)) {
3021		mutex_unlock(&eli->li_list_mtx);
3022		mutex_unlock(&ext4_li_mtx);
3023		goto cont_thread;
3024	}
3025	mutex_unlock(&eli->li_list_mtx);
3026	kfree(ext4_li_info);
3027	ext4_li_info = NULL;
3028	mutex_unlock(&ext4_li_mtx);
3029
3030	return 0;
3031}
3032
3033static void ext4_clear_request_list(void)
3034{
3035	struct list_head *pos, *n;
3036	struct ext4_li_request *elr;
3037
3038	mutex_lock(&ext4_li_info->li_list_mtx);
3039	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3040		elr = list_entry(pos, struct ext4_li_request,
3041				 lr_request);
3042		ext4_remove_li_request(elr);
3043	}
3044	mutex_unlock(&ext4_li_info->li_list_mtx);
3045}
3046
3047static int ext4_run_lazyinit_thread(void)
3048{
3049	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3050					 ext4_li_info, "ext4lazyinit");
3051	if (IS_ERR(ext4_lazyinit_task)) {
3052		int err = PTR_ERR(ext4_lazyinit_task);
3053		ext4_clear_request_list();
3054		kfree(ext4_li_info);
3055		ext4_li_info = NULL;
3056		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3057				 "initialization thread\n",
3058				 err);
3059		return err;
3060	}
3061	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3062	return 0;
3063}
3064
3065/*
3066 * Check whether it make sense to run itable init. thread or not.
3067 * If there is at least one uninitialized inode table, return
3068 * corresponding group number, else the loop goes through all
3069 * groups and return total number of groups.
3070 */
3071static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3072{
3073	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3074	struct ext4_group_desc *gdp = NULL;
3075
3076	for (group = 0; group < ngroups; group++) {
3077		gdp = ext4_get_group_desc(sb, group, NULL);
3078		if (!gdp)
3079			continue;
3080
3081		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3082			break;
3083	}
3084
3085	return group;
3086}
3087
3088static int ext4_li_info_new(void)
3089{
3090	struct ext4_lazy_init *eli = NULL;
3091
3092	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3093	if (!eli)
3094		return -ENOMEM;
3095
3096	INIT_LIST_HEAD(&eli->li_request_list);
3097	mutex_init(&eli->li_list_mtx);
3098
3099	eli->li_state |= EXT4_LAZYINIT_QUIT;
3100
3101	ext4_li_info = eli;
3102
3103	return 0;
3104}
3105
3106static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3107					    ext4_group_t start)
3108{
3109	struct ext4_sb_info *sbi = EXT4_SB(sb);
3110	struct ext4_li_request *elr;
3111
3112	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3113	if (!elr)
3114		return NULL;
3115
3116	elr->lr_super = sb;
3117	elr->lr_sbi = sbi;
3118	elr->lr_next_group = start;
3119
3120	/*
3121	 * Randomize first schedule time of the request to
3122	 * spread the inode table initialization requests
3123	 * better.
3124	 */
3125	elr->lr_next_sched = jiffies + (prandom_u32() %
3126				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3127	return elr;
3128}
3129
3130int ext4_register_li_request(struct super_block *sb,
3131			     ext4_group_t first_not_zeroed)
3132{
3133	struct ext4_sb_info *sbi = EXT4_SB(sb);
3134	struct ext4_li_request *elr = NULL;
3135	ext4_group_t ngroups = sbi->s_groups_count;
3136	int ret = 0;
3137
3138	mutex_lock(&ext4_li_mtx);
3139	if (sbi->s_li_request != NULL) {
3140		/*
3141		 * Reset timeout so it can be computed again, because
3142		 * s_li_wait_mult might have changed.
3143		 */
3144		sbi->s_li_request->lr_timeout = 0;
3145		goto out;
3146	}
3147
3148	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
 
3149	    !test_opt(sb, INIT_INODE_TABLE))
3150		goto out;
3151
3152	elr = ext4_li_request_new(sb, first_not_zeroed);
3153	if (!elr) {
3154		ret = -ENOMEM;
3155		goto out;
3156	}
3157
3158	if (NULL == ext4_li_info) {
3159		ret = ext4_li_info_new();
3160		if (ret)
3161			goto out;
3162	}
3163
3164	mutex_lock(&ext4_li_info->li_list_mtx);
3165	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3166	mutex_unlock(&ext4_li_info->li_list_mtx);
3167
3168	sbi->s_li_request = elr;
3169	/*
3170	 * set elr to NULL here since it has been inserted to
3171	 * the request_list and the removal and free of it is
3172	 * handled by ext4_clear_request_list from now on.
3173	 */
3174	elr = NULL;
3175
3176	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3177		ret = ext4_run_lazyinit_thread();
3178		if (ret)
3179			goto out;
3180	}
3181out:
3182	mutex_unlock(&ext4_li_mtx);
3183	if (ret)
3184		kfree(elr);
3185	return ret;
3186}
3187
3188/*
3189 * We do not need to lock anything since this is called on
3190 * module unload.
3191 */
3192static void ext4_destroy_lazyinit_thread(void)
3193{
3194	/*
3195	 * If thread exited earlier
3196	 * there's nothing to be done.
3197	 */
3198	if (!ext4_li_info || !ext4_lazyinit_task)
3199		return;
3200
3201	kthread_stop(ext4_lazyinit_task);
3202}
3203
3204static int set_journal_csum_feature_set(struct super_block *sb)
3205{
3206	int ret = 1;
3207	int compat, incompat;
3208	struct ext4_sb_info *sbi = EXT4_SB(sb);
3209
3210	if (ext4_has_metadata_csum(sb)) {
3211		/* journal checksum v3 */
3212		compat = 0;
3213		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3214	} else {
3215		/* journal checksum v1 */
3216		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3217		incompat = 0;
3218	}
3219
3220	jbd2_journal_clear_features(sbi->s_journal,
3221			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3222			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3223			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3224	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3225		ret = jbd2_journal_set_features(sbi->s_journal,
3226				compat, 0,
3227				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3228				incompat);
3229	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3230		ret = jbd2_journal_set_features(sbi->s_journal,
3231				compat, 0,
3232				incompat);
3233		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3234				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3235	} else {
3236		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3237				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3238	}
3239
3240	return ret;
3241}
3242
3243/*
3244 * Note: calculating the overhead so we can be compatible with
3245 * historical BSD practice is quite difficult in the face of
3246 * clusters/bigalloc.  This is because multiple metadata blocks from
3247 * different block group can end up in the same allocation cluster.
3248 * Calculating the exact overhead in the face of clustered allocation
3249 * requires either O(all block bitmaps) in memory or O(number of block
3250 * groups**2) in time.  We will still calculate the superblock for
3251 * older file systems --- and if we come across with a bigalloc file
3252 * system with zero in s_overhead_clusters the estimate will be close to
3253 * correct especially for very large cluster sizes --- but for newer
3254 * file systems, it's better to calculate this figure once at mkfs
3255 * time, and store it in the superblock.  If the superblock value is
3256 * present (even for non-bigalloc file systems), we will use it.
3257 */
3258static int count_overhead(struct super_block *sb, ext4_group_t grp,
3259			  char *buf)
3260{
3261	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3262	struct ext4_group_desc	*gdp;
3263	ext4_fsblk_t		first_block, last_block, b;
3264	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3265	int			s, j, count = 0;
3266
3267	if (!ext4_has_feature_bigalloc(sb))
3268		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3269			sbi->s_itb_per_group + 2);
3270
3271	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3272		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3273	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3274	for (i = 0; i < ngroups; i++) {
3275		gdp = ext4_get_group_desc(sb, i, NULL);
3276		b = ext4_block_bitmap(sb, gdp);
3277		if (b >= first_block && b <= last_block) {
3278			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3279			count++;
3280		}
3281		b = ext4_inode_bitmap(sb, gdp);
3282		if (b >= first_block && b <= last_block) {
3283			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3284			count++;
3285		}
3286		b = ext4_inode_table(sb, gdp);
3287		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3288			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3289				int c = EXT4_B2C(sbi, b - first_block);
3290				ext4_set_bit(c, buf);
3291				count++;
3292			}
3293		if (i != grp)
3294			continue;
3295		s = 0;
3296		if (ext4_bg_has_super(sb, grp)) {
3297			ext4_set_bit(s++, buf);
3298			count++;
3299		}
3300		j = ext4_bg_num_gdb(sb, grp);
3301		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3302			ext4_error(sb, "Invalid number of block group "
3303				   "descriptor blocks: %d", j);
3304			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3305		}
3306		count += j;
3307		for (; j > 0; j--)
3308			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
 
 
3309	}
3310	if (!count)
3311		return 0;
3312	return EXT4_CLUSTERS_PER_GROUP(sb) -
3313		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3314}
3315
3316/*
3317 * Compute the overhead and stash it in sbi->s_overhead
3318 */
3319int ext4_calculate_overhead(struct super_block *sb)
3320{
3321	struct ext4_sb_info *sbi = EXT4_SB(sb);
3322	struct ext4_super_block *es = sbi->s_es;
3323	struct inode *j_inode;
3324	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3325	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3326	ext4_fsblk_t overhead = 0;
3327	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3328
3329	if (!buf)
3330		return -ENOMEM;
3331
3332	/*
3333	 * Compute the overhead (FS structures).  This is constant
3334	 * for a given filesystem unless the number of block groups
3335	 * changes so we cache the previous value until it does.
3336	 */
3337
3338	/*
3339	 * All of the blocks before first_data_block are overhead
3340	 */
3341	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3342
3343	/*
3344	 * Add the overhead found in each block group
3345	 */
3346	for (i = 0; i < ngroups; i++) {
3347		int blks;
3348
3349		blks = count_overhead(sb, i, buf);
3350		overhead += blks;
3351		if (blks)
3352			memset(buf, 0, PAGE_SIZE);
3353		cond_resched();
3354	}
3355
3356	/*
3357	 * Add the internal journal blocks whether the journal has been
3358	 * loaded or not
3359	 */
3360	if (sbi->s_journal && !sbi->journal_bdev)
3361		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3362	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3363		j_inode = ext4_get_journal_inode(sb, j_inum);
3364		if (j_inode) {
3365			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3366			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3367			iput(j_inode);
3368		} else {
3369			ext4_msg(sb, KERN_ERR, "can't get journal size");
3370		}
3371	}
3372	sbi->s_overhead = overhead;
3373	smp_wmb();
3374	free_page((unsigned long) buf);
3375	return 0;
3376}
3377
3378static void ext4_set_resv_clusters(struct super_block *sb)
3379{
3380	ext4_fsblk_t resv_clusters;
3381	struct ext4_sb_info *sbi = EXT4_SB(sb);
3382
3383	/*
3384	 * There's no need to reserve anything when we aren't using extents.
3385	 * The space estimates are exact, there are no unwritten extents,
3386	 * hole punching doesn't need new metadata... This is needed especially
3387	 * to keep ext2/3 backward compatibility.
3388	 */
3389	if (!ext4_has_feature_extents(sb))
3390		return;
3391	/*
3392	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3393	 * This should cover the situations where we can not afford to run
3394	 * out of space like for example punch hole, or converting
3395	 * unwritten extents in delalloc path. In most cases such
3396	 * allocation would require 1, or 2 blocks, higher numbers are
3397	 * very rare.
3398	 */
3399	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3400			 sbi->s_cluster_bits);
3401
3402	do_div(resv_clusters, 50);
3403	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3404
3405	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3406}
3407
3408static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3409{
3410	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3411	char *orig_data = kstrdup(data, GFP_KERNEL);
3412	struct buffer_head *bh;
3413	struct ext4_super_block *es = NULL;
3414	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3415	ext4_fsblk_t block;
3416	ext4_fsblk_t sb_block = get_sb_block(&data);
3417	ext4_fsblk_t logical_sb_block;
3418	unsigned long offset = 0;
3419	unsigned long journal_devnum = 0;
3420	unsigned long def_mount_opts;
3421	struct inode *root;
3422	const char *descr;
3423	int ret = -ENOMEM;
3424	int blocksize, clustersize;
3425	unsigned int db_count;
3426	unsigned int i;
3427	int needs_recovery, has_huge_files, has_bigalloc;
3428	__u64 blocks_count;
3429	int err = 0;
3430	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3431	ext4_group_t first_not_zeroed;
3432
3433	if ((data && !orig_data) || !sbi)
3434		goto out_free_base;
 
3435
3436	sbi->s_daxdev = dax_dev;
3437	sbi->s_blockgroup_lock =
3438		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3439	if (!sbi->s_blockgroup_lock)
3440		goto out_free_base;
3441
 
3442	sb->s_fs_info = sbi;
3443	sbi->s_sb = sb;
3444	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3445	sbi->s_sb_block = sb_block;
3446	if (sb->s_bdev->bd_part)
3447		sbi->s_sectors_written_start =
3448			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3449
3450	/* Cleanup superblock name */
3451	strreplace(sb->s_id, '/', '!');
3452
3453	/* -EINVAL is default */
3454	ret = -EINVAL;
3455	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3456	if (!blocksize) {
3457		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3458		goto out_fail;
3459	}
3460
3461	/*
3462	 * The ext4 superblock will not be buffer aligned for other than 1kB
3463	 * block sizes.  We need to calculate the offset from buffer start.
3464	 */
3465	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3466		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3467		offset = do_div(logical_sb_block, blocksize);
3468	} else {
3469		logical_sb_block = sb_block;
3470	}
3471
3472	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3473		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3474		goto out_fail;
3475	}
3476	/*
3477	 * Note: s_es must be initialized as soon as possible because
3478	 *       some ext4 macro-instructions depend on its value
3479	 */
3480	es = (struct ext4_super_block *) (bh->b_data + offset);
3481	sbi->s_es = es;
3482	sb->s_magic = le16_to_cpu(es->s_magic);
3483	if (sb->s_magic != EXT4_SUPER_MAGIC)
3484		goto cantfind_ext4;
3485	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3486
3487	/* Warn if metadata_csum and gdt_csum are both set. */
3488	if (ext4_has_feature_metadata_csum(sb) &&
3489	    ext4_has_feature_gdt_csum(sb))
3490		ext4_warning(sb, "metadata_csum and uninit_bg are "
3491			     "redundant flags; please run fsck.");
3492
3493	/* Check for a known checksum algorithm */
3494	if (!ext4_verify_csum_type(sb, es)) {
3495		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3496			 "unknown checksum algorithm.");
3497		silent = 1;
3498		goto cantfind_ext4;
3499	}
3500
3501	/* Load the checksum driver */
3502	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3503	if (IS_ERR(sbi->s_chksum_driver)) {
3504		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3505		ret = PTR_ERR(sbi->s_chksum_driver);
3506		sbi->s_chksum_driver = NULL;
3507		goto failed_mount;
 
 
3508	}
3509
3510	/* Check superblock checksum */
3511	if (!ext4_superblock_csum_verify(sb, es)) {
3512		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3513			 "invalid superblock checksum.  Run e2fsck?");
3514		silent = 1;
3515		ret = -EFSBADCRC;
3516		goto cantfind_ext4;
3517	}
3518
3519	/* Precompute checksum seed for all metadata */
3520	if (ext4_has_feature_csum_seed(sb))
3521		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3522	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3523		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3524					       sizeof(es->s_uuid));
3525
3526	/* Set defaults before we parse the mount options */
3527	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3528	set_opt(sb, INIT_INODE_TABLE);
3529	if (def_mount_opts & EXT4_DEFM_DEBUG)
3530		set_opt(sb, DEBUG);
3531	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3532		set_opt(sb, GRPID);
3533	if (def_mount_opts & EXT4_DEFM_UID16)
3534		set_opt(sb, NO_UID32);
3535	/* xattr user namespace & acls are now defaulted on */
3536	set_opt(sb, XATTR_USER);
3537#ifdef CONFIG_EXT4_FS_POSIX_ACL
3538	set_opt(sb, POSIX_ACL);
3539#endif
3540	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3541	if (ext4_has_metadata_csum(sb))
3542		set_opt(sb, JOURNAL_CHECKSUM);
3543
3544	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3545		set_opt(sb, JOURNAL_DATA);
3546	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3547		set_opt(sb, ORDERED_DATA);
3548	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3549		set_opt(sb, WRITEBACK_DATA);
3550
3551	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3552		set_opt(sb, ERRORS_PANIC);
3553	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3554		set_opt(sb, ERRORS_CONT);
3555	else
3556		set_opt(sb, ERRORS_RO);
3557	/* block_validity enabled by default; disable with noblock_validity */
3558	set_opt(sb, BLOCK_VALIDITY);
3559	if (def_mount_opts & EXT4_DEFM_DISCARD)
3560		set_opt(sb, DISCARD);
3561
3562	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3563	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3564	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3565	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3566	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3567
3568	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3569		set_opt(sb, BARRIER);
3570
3571	/*
3572	 * enable delayed allocation by default
3573	 * Use -o nodelalloc to turn it off
3574	 */
3575	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3576	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3577		set_opt(sb, DELALLOC);
3578
3579	/*
3580	 * set default s_li_wait_mult for lazyinit, for the case there is
3581	 * no mount option specified.
3582	 */
3583	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3584
3585	if (sbi->s_es->s_mount_opts[0]) {
3586		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3587					      sizeof(sbi->s_es->s_mount_opts),
3588					      GFP_KERNEL);
3589		if (!s_mount_opts)
3590			goto failed_mount;
3591		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3592				   &journal_ioprio, 0)) {
3593			ext4_msg(sb, KERN_WARNING,
3594				 "failed to parse options in superblock: %s",
3595				 s_mount_opts);
3596		}
3597		kfree(s_mount_opts);
3598	}
3599	sbi->s_def_mount_opt = sbi->s_mount_opt;
3600	if (!parse_options((char *) data, sb, &journal_devnum,
3601			   &journal_ioprio, 0))
3602		goto failed_mount;
3603
3604	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3605		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3606			    "with data=journal disables delayed "
3607			    "allocation and O_DIRECT support!\n");
3608		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3609			ext4_msg(sb, KERN_ERR, "can't mount with "
3610				 "both data=journal and delalloc");
3611			goto failed_mount;
3612		}
3613		if (test_opt(sb, DIOREAD_NOLOCK)) {
3614			ext4_msg(sb, KERN_ERR, "can't mount with "
3615				 "both data=journal and dioread_nolock");
3616			goto failed_mount;
3617		}
3618		if (test_opt(sb, DAX)) {
3619			ext4_msg(sb, KERN_ERR, "can't mount with "
3620				 "both data=journal and dax");
3621			goto failed_mount;
3622		}
3623		if (ext4_has_feature_encrypt(sb)) {
3624			ext4_msg(sb, KERN_WARNING,
3625				 "encrypted files will use data=ordered "
3626				 "instead of data journaling mode");
3627		}
3628		if (test_opt(sb, DELALLOC))
3629			clear_opt(sb, DELALLOC);
3630	} else {
3631		sb->s_iflags |= SB_I_CGROUPWB;
3632	}
3633
3634	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3635		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3636
3637	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3638	    (ext4_has_compat_features(sb) ||
3639	     ext4_has_ro_compat_features(sb) ||
3640	     ext4_has_incompat_features(sb)))
3641		ext4_msg(sb, KERN_WARNING,
3642		       "feature flags set on rev 0 fs, "
3643		       "running e2fsck is recommended");
3644
3645	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3646		set_opt2(sb, HURD_COMPAT);
3647		if (ext4_has_feature_64bit(sb)) {
3648			ext4_msg(sb, KERN_ERR,
3649				 "The Hurd can't support 64-bit file systems");
3650			goto failed_mount;
3651		}
3652
3653		/*
3654		 * ea_inode feature uses l_i_version field which is not
3655		 * available in HURD_COMPAT mode.
3656		 */
3657		if (ext4_has_feature_ea_inode(sb)) {
3658			ext4_msg(sb, KERN_ERR,
3659				 "ea_inode feature is not supported for Hurd");
3660			goto failed_mount;
3661		}
3662	}
3663
3664	if (IS_EXT2_SB(sb)) {
3665		if (ext2_feature_set_ok(sb))
3666			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3667				 "using the ext4 subsystem");
3668		else {
3669			/*
3670			 * If we're probing be silent, if this looks like
3671			 * it's actually an ext[34] filesystem.
3672			 */
3673			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3674				goto failed_mount;
3675			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3676				 "to feature incompatibilities");
3677			goto failed_mount;
3678		}
3679	}
3680
3681	if (IS_EXT3_SB(sb)) {
3682		if (ext3_feature_set_ok(sb))
3683			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3684				 "using the ext4 subsystem");
3685		else {
3686			/*
3687			 * If we're probing be silent, if this looks like
3688			 * it's actually an ext4 filesystem.
3689			 */
3690			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3691				goto failed_mount;
3692			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3693				 "to feature incompatibilities");
3694			goto failed_mount;
3695		}
3696	}
3697
3698	/*
3699	 * Check feature flags regardless of the revision level, since we
3700	 * previously didn't change the revision level when setting the flags,
3701	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3702	 */
3703	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3704		goto failed_mount;
3705
3706	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3707	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3708	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3709		ext4_msg(sb, KERN_ERR,
3710		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3711			 blocksize, le32_to_cpu(es->s_log_block_size));
3712		goto failed_mount;
3713	}
3714	if (le32_to_cpu(es->s_log_block_size) >
3715	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3716		ext4_msg(sb, KERN_ERR,
3717			 "Invalid log block size: %u",
3718			 le32_to_cpu(es->s_log_block_size));
3719		goto failed_mount;
3720	}
3721
3722	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3723		ext4_msg(sb, KERN_ERR,
3724			 "Number of reserved GDT blocks insanely large: %d",
3725			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3726		goto failed_mount;
3727	}
3728
3729	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3730		if (ext4_has_feature_inline_data(sb)) {
3731			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3732					" that may contain inline data");
3733			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3734		}
3735		err = bdev_dax_supported(sb, blocksize);
3736		if (err) {
3737			ext4_msg(sb, KERN_ERR,
3738				"DAX unsupported by block device. Turning off DAX.");
3739			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3740		}
3741	}
3742
3743	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3744		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3745			 es->s_encryption_level);
3746		goto failed_mount;
3747	}
3748
3749	if (sb->s_blocksize != blocksize) {
3750		/* Validate the filesystem blocksize */
3751		if (!sb_set_blocksize(sb, blocksize)) {
3752			ext4_msg(sb, KERN_ERR, "bad block size %d",
3753					blocksize);
3754			goto failed_mount;
3755		}
3756
3757		brelse(bh);
3758		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3759		offset = do_div(logical_sb_block, blocksize);
3760		bh = sb_bread_unmovable(sb, logical_sb_block);
3761		if (!bh) {
3762			ext4_msg(sb, KERN_ERR,
3763			       "Can't read superblock on 2nd try");
3764			goto failed_mount;
3765		}
3766		es = (struct ext4_super_block *)(bh->b_data + offset);
3767		sbi->s_es = es;
3768		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3769			ext4_msg(sb, KERN_ERR,
3770			       "Magic mismatch, very weird!");
3771			goto failed_mount;
3772		}
3773	}
3774
3775	has_huge_files = ext4_has_feature_huge_file(sb);
3776	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3777						      has_huge_files);
3778	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3779
3780	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3781		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3782		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3783	} else {
3784		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3785		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3786		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3787		    (!is_power_of_2(sbi->s_inode_size)) ||
3788		    (sbi->s_inode_size > blocksize)) {
3789			ext4_msg(sb, KERN_ERR,
3790			       "unsupported inode size: %d",
3791			       sbi->s_inode_size);
3792			goto failed_mount;
3793		}
3794		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3795			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3796	}
3797
3798	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3799	if (ext4_has_feature_64bit(sb)) {
3800		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3801		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3802		    !is_power_of_2(sbi->s_desc_size)) {
3803			ext4_msg(sb, KERN_ERR,
3804			       "unsupported descriptor size %lu",
3805			       sbi->s_desc_size);
3806			goto failed_mount;
3807		}
3808	} else
3809		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3810
3811	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3812	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 
 
3813
3814	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3815	if (sbi->s_inodes_per_block == 0)
3816		goto cantfind_ext4;
3817	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3818	    sbi->s_inodes_per_group > blocksize * 8) {
3819		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3820			 sbi->s_blocks_per_group);
3821		goto failed_mount;
3822	}
3823	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3824					sbi->s_inodes_per_block;
3825	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3826	sbi->s_sbh = bh;
3827	sbi->s_mount_state = le16_to_cpu(es->s_state);
3828	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3829	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3830
3831	for (i = 0; i < 4; i++)
3832		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3833	sbi->s_def_hash_version = es->s_def_hash_version;
3834	if (ext4_has_feature_dir_index(sb)) {
3835		i = le32_to_cpu(es->s_flags);
3836		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3837			sbi->s_hash_unsigned = 3;
3838		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3839#ifdef __CHAR_UNSIGNED__
3840			if (!sb_rdonly(sb))
3841				es->s_flags |=
3842					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3843			sbi->s_hash_unsigned = 3;
3844#else
3845			if (!sb_rdonly(sb))
3846				es->s_flags |=
3847					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3848#endif
3849		}
3850	}
3851
3852	/* Handle clustersize */
3853	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3854	has_bigalloc = ext4_has_feature_bigalloc(sb);
3855	if (has_bigalloc) {
3856		if (clustersize < blocksize) {
3857			ext4_msg(sb, KERN_ERR,
3858				 "cluster size (%d) smaller than "
3859				 "block size (%d)", clustersize, blocksize);
3860			goto failed_mount;
3861		}
3862		if (le32_to_cpu(es->s_log_cluster_size) >
3863		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3864			ext4_msg(sb, KERN_ERR,
3865				 "Invalid log cluster size: %u",
3866				 le32_to_cpu(es->s_log_cluster_size));
3867			goto failed_mount;
3868		}
3869		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3870			le32_to_cpu(es->s_log_block_size);
3871		sbi->s_clusters_per_group =
3872			le32_to_cpu(es->s_clusters_per_group);
3873		if (sbi->s_clusters_per_group > blocksize * 8) {
3874			ext4_msg(sb, KERN_ERR,
3875				 "#clusters per group too big: %lu",
3876				 sbi->s_clusters_per_group);
3877			goto failed_mount;
3878		}
3879		if (sbi->s_blocks_per_group !=
3880		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3881			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3882				 "clusters per group (%lu) inconsistent",
3883				 sbi->s_blocks_per_group,
3884				 sbi->s_clusters_per_group);
3885			goto failed_mount;
3886		}
3887	} else {
3888		if (clustersize != blocksize) {
3889			ext4_warning(sb, "fragment/cluster size (%d) != "
3890				     "block size (%d)", clustersize,
3891				     blocksize);
3892			clustersize = blocksize;
3893		}
3894		if (sbi->s_blocks_per_group > blocksize * 8) {
3895			ext4_msg(sb, KERN_ERR,
3896				 "#blocks per group too big: %lu",
3897				 sbi->s_blocks_per_group);
3898			goto failed_mount;
3899		}
3900		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3901		sbi->s_cluster_bits = 0;
3902	}
3903	sbi->s_cluster_ratio = clustersize / blocksize;
3904
 
 
 
 
 
 
 
3905	/* Do we have standard group size of clustersize * 8 blocks ? */
3906	if (sbi->s_blocks_per_group == clustersize << 3)
3907		set_opt2(sb, STD_GROUP_SIZE);
3908
3909	/*
3910	 * Test whether we have more sectors than will fit in sector_t,
3911	 * and whether the max offset is addressable by the page cache.
3912	 */
3913	err = generic_check_addressable(sb->s_blocksize_bits,
3914					ext4_blocks_count(es));
3915	if (err) {
3916		ext4_msg(sb, KERN_ERR, "filesystem"
3917			 " too large to mount safely on this system");
3918		if (sizeof(sector_t) < 8)
3919			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3920		goto failed_mount;
3921	}
3922
3923	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3924		goto cantfind_ext4;
3925
3926	/* check blocks count against device size */
3927	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3928	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3929		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3930		       "exceeds size of device (%llu blocks)",
3931		       ext4_blocks_count(es), blocks_count);
3932		goto failed_mount;
3933	}
3934
3935	/*
3936	 * It makes no sense for the first data block to be beyond the end
3937	 * of the filesystem.
3938	 */
3939	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3940		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3941			 "block %u is beyond end of filesystem (%llu)",
3942			 le32_to_cpu(es->s_first_data_block),
3943			 ext4_blocks_count(es));
3944		goto failed_mount;
3945	}
3946	blocks_count = (ext4_blocks_count(es) -
3947			le32_to_cpu(es->s_first_data_block) +
3948			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3949	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3950	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3951		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3952		       "(block count %llu, first data block %u, "
3953		       "blocks per group %lu)", sbi->s_groups_count,
3954		       ext4_blocks_count(es),
3955		       le32_to_cpu(es->s_first_data_block),
3956		       EXT4_BLOCKS_PER_GROUP(sb));
3957		goto failed_mount;
3958	}
3959	sbi->s_groups_count = blocks_count;
3960	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3961			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3962	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3963		   EXT4_DESC_PER_BLOCK(sb);
3964	if (ext4_has_feature_meta_bg(sb)) {
3965		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3966			ext4_msg(sb, KERN_WARNING,
3967				 "first meta block group too large: %u "
3968				 "(group descriptor block count %u)",
3969				 le32_to_cpu(es->s_first_meta_bg), db_count);
3970			goto failed_mount;
3971		}
3972	}
3973	sbi->s_group_desc = kvmalloc(db_count *
3974					  sizeof(struct buffer_head *),
3975					  GFP_KERNEL);
3976	if (sbi->s_group_desc == NULL) {
3977		ext4_msg(sb, KERN_ERR, "not enough memory");
3978		ret = -ENOMEM;
3979		goto failed_mount;
3980	}
3981
3982	bgl_lock_init(sbi->s_blockgroup_lock);
3983
3984	/* Pre-read the descriptors into the buffer cache */
3985	for (i = 0; i < db_count; i++) {
3986		block = descriptor_loc(sb, logical_sb_block, i);
3987		sb_breadahead(sb, block);
3988	}
3989
3990	for (i = 0; i < db_count; i++) {
3991		block = descriptor_loc(sb, logical_sb_block, i);
3992		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3993		if (!sbi->s_group_desc[i]) {
3994			ext4_msg(sb, KERN_ERR,
3995			       "can't read group descriptor %d", i);
3996			db_count = i;
3997			goto failed_mount2;
3998		}
3999	}
4000	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4001		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4002		ret = -EFSCORRUPTED;
4003		goto failed_mount2;
4004	}
4005
4006	sbi->s_gdb_count = db_count;
 
 
4007
4008	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
 
4009
4010	/* Register extent status tree shrinker */
4011	if (ext4_es_register_shrinker(sbi))
4012		goto failed_mount3;
4013
4014	sbi->s_stripe = ext4_get_stripe_size(sbi);
4015	sbi->s_extent_max_zeroout_kb = 32;
4016
4017	/*
4018	 * set up enough so that it can read an inode
4019	 */
4020	sb->s_op = &ext4_sops;
4021	sb->s_export_op = &ext4_export_ops;
4022	sb->s_xattr = ext4_xattr_handlers;
4023#ifdef CONFIG_EXT4_FS_ENCRYPTION
4024	sb->s_cop = &ext4_cryptops;
4025#endif
4026#ifdef CONFIG_QUOTA
4027	sb->dq_op = &ext4_quota_operations;
4028	if (ext4_has_feature_quota(sb))
4029		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4030	else
4031		sb->s_qcop = &ext4_qctl_operations;
4032	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4033#endif
4034	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4035
4036	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4037	mutex_init(&sbi->s_orphan_lock);
4038
4039	sb->s_root = NULL;
4040
4041	needs_recovery = (es->s_last_orphan != 0 ||
4042			  ext4_has_feature_journal_needs_recovery(sb));
4043
4044	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4045		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4046			goto failed_mount3a;
4047
4048	/*
4049	 * The first inode we look at is the journal inode.  Don't try
4050	 * root first: it may be modified in the journal!
4051	 */
4052	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4053		err = ext4_load_journal(sb, es, journal_devnum);
4054		if (err)
4055			goto failed_mount3a;
4056	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4057		   ext4_has_feature_journal_needs_recovery(sb)) {
4058		ext4_msg(sb, KERN_ERR, "required journal recovery "
4059		       "suppressed and not mounted read-only");
4060		goto failed_mount_wq;
4061	} else {
4062		/* Nojournal mode, all journal mount options are illegal */
4063		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4064			ext4_msg(sb, KERN_ERR, "can't mount with "
4065				 "journal_checksum, fs mounted w/o journal");
4066			goto failed_mount_wq;
4067		}
4068		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4069			ext4_msg(sb, KERN_ERR, "can't mount with "
4070				 "journal_async_commit, fs mounted w/o journal");
4071			goto failed_mount_wq;
4072		}
4073		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4074			ext4_msg(sb, KERN_ERR, "can't mount with "
4075				 "commit=%lu, fs mounted w/o journal",
4076				 sbi->s_commit_interval / HZ);
4077			goto failed_mount_wq;
4078		}
4079		if (EXT4_MOUNT_DATA_FLAGS &
4080		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4081			ext4_msg(sb, KERN_ERR, "can't mount with "
4082				 "data=, fs mounted w/o journal");
4083			goto failed_mount_wq;
4084		}
4085		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4086		clear_opt(sb, JOURNAL_CHECKSUM);
4087		clear_opt(sb, DATA_FLAGS);
4088		sbi->s_journal = NULL;
4089		needs_recovery = 0;
4090		goto no_journal;
4091	}
4092
4093	if (ext4_has_feature_64bit(sb) &&
4094	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4095				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4096		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4097		goto failed_mount_wq;
4098	}
4099
4100	if (!set_journal_csum_feature_set(sb)) {
4101		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4102			 "feature set");
4103		goto failed_mount_wq;
4104	}
4105
4106	/* We have now updated the journal if required, so we can
4107	 * validate the data journaling mode. */
4108	switch (test_opt(sb, DATA_FLAGS)) {
4109	case 0:
4110		/* No mode set, assume a default based on the journal
4111		 * capabilities: ORDERED_DATA if the journal can
4112		 * cope, else JOURNAL_DATA
4113		 */
4114		if (jbd2_journal_check_available_features
4115		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4116			set_opt(sb, ORDERED_DATA);
4117			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4118		} else {
4119			set_opt(sb, JOURNAL_DATA);
4120			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4121		}
4122		break;
4123
4124	case EXT4_MOUNT_ORDERED_DATA:
4125	case EXT4_MOUNT_WRITEBACK_DATA:
4126		if (!jbd2_journal_check_available_features
4127		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4128			ext4_msg(sb, KERN_ERR, "Journal does not support "
4129			       "requested data journaling mode");
4130			goto failed_mount_wq;
4131		}
4132	default:
4133		break;
4134	}
4135
4136	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4137	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4138		ext4_msg(sb, KERN_ERR, "can't mount with "
4139			"journal_async_commit in data=ordered mode");
4140		goto failed_mount_wq;
4141	}
4142
4143	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4144
4145	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4146
4147no_journal:
4148	if (!test_opt(sb, NO_MBCACHE)) {
4149		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4150		if (!sbi->s_ea_block_cache) {
4151			ext4_msg(sb, KERN_ERR,
4152				 "Failed to create ea_block_cache");
4153			goto failed_mount_wq;
4154		}
4155
4156		if (ext4_has_feature_ea_inode(sb)) {
4157			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4158			if (!sbi->s_ea_inode_cache) {
4159				ext4_msg(sb, KERN_ERR,
4160					 "Failed to create ea_inode_cache");
4161				goto failed_mount_wq;
4162			}
4163		}
4164	}
4165
4166	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4167	    (blocksize != PAGE_SIZE)) {
4168		ext4_msg(sb, KERN_ERR,
4169			 "Unsupported blocksize for fs encryption");
4170		goto failed_mount_wq;
4171	}
4172
4173	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4174	    !ext4_has_feature_encrypt(sb)) {
4175		ext4_set_feature_encrypt(sb);
4176		ext4_commit_super(sb, 1);
4177	}
4178
4179	/*
4180	 * Get the # of file system overhead blocks from the
4181	 * superblock if present.
4182	 */
4183	if (es->s_overhead_clusters)
4184		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4185	else {
4186		err = ext4_calculate_overhead(sb);
4187		if (err)
4188			goto failed_mount_wq;
4189	}
4190
4191	/*
4192	 * The maximum number of concurrent works can be high and
4193	 * concurrency isn't really necessary.  Limit it to 1.
4194	 */
4195	EXT4_SB(sb)->rsv_conversion_wq =
4196		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4197	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4198		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4199		ret = -ENOMEM;
4200		goto failed_mount4;
4201	}
4202
4203	/*
4204	 * The jbd2_journal_load will have done any necessary log recovery,
4205	 * so we can safely mount the rest of the filesystem now.
4206	 */
4207
4208	root = ext4_iget(sb, EXT4_ROOT_INO);
4209	if (IS_ERR(root)) {
4210		ext4_msg(sb, KERN_ERR, "get root inode failed");
4211		ret = PTR_ERR(root);
4212		root = NULL;
4213		goto failed_mount4;
4214	}
4215	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4216		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4217		iput(root);
4218		goto failed_mount4;
4219	}
4220	sb->s_root = d_make_root(root);
4221	if (!sb->s_root) {
4222		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4223		ret = -ENOMEM;
4224		goto failed_mount4;
4225	}
4226
4227	if (ext4_setup_super(sb, es, sb_rdonly(sb)))
4228		sb->s_flags |= SB_RDONLY;
4229
4230	/* determine the minimum size of new large inodes, if present */
4231	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4232	    sbi->s_want_extra_isize == 0) {
4233		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4234						     EXT4_GOOD_OLD_INODE_SIZE;
4235		if (ext4_has_feature_extra_isize(sb)) {
4236			if (sbi->s_want_extra_isize <
4237			    le16_to_cpu(es->s_want_extra_isize))
4238				sbi->s_want_extra_isize =
4239					le16_to_cpu(es->s_want_extra_isize);
4240			if (sbi->s_want_extra_isize <
4241			    le16_to_cpu(es->s_min_extra_isize))
4242				sbi->s_want_extra_isize =
4243					le16_to_cpu(es->s_min_extra_isize);
4244		}
4245	}
4246	/* Check if enough inode space is available */
4247	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4248							sbi->s_inode_size) {
4249		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4250						       EXT4_GOOD_OLD_INODE_SIZE;
4251		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4252			 "available");
4253	}
4254
4255	ext4_set_resv_clusters(sb);
4256
4257	err = ext4_setup_system_zone(sb);
4258	if (err) {
4259		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4260			 "zone (%d)", err);
4261		goto failed_mount4a;
4262	}
4263
4264	ext4_ext_init(sb);
4265	err = ext4_mb_init(sb);
4266	if (err) {
4267		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4268			 err);
4269		goto failed_mount5;
4270	}
4271
4272	block = ext4_count_free_clusters(sb);
4273	ext4_free_blocks_count_set(sbi->s_es, 
4274				   EXT4_C2B(sbi, block));
4275	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4276				  GFP_KERNEL);
4277	if (!err) {
4278		unsigned long freei = ext4_count_free_inodes(sb);
4279		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4280		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4281					  GFP_KERNEL);
4282	}
4283	if (!err)
4284		err = percpu_counter_init(&sbi->s_dirs_counter,
4285					  ext4_count_dirs(sb), GFP_KERNEL);
4286	if (!err)
4287		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4288					  GFP_KERNEL);
4289	if (!err)
4290		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4291
4292	if (err) {
4293		ext4_msg(sb, KERN_ERR, "insufficient memory");
4294		goto failed_mount6;
4295	}
4296
4297	if (ext4_has_feature_flex_bg(sb))
4298		if (!ext4_fill_flex_info(sb)) {
4299			ext4_msg(sb, KERN_ERR,
4300			       "unable to initialize "
4301			       "flex_bg meta info!");
4302			goto failed_mount6;
4303		}
4304
4305	err = ext4_register_li_request(sb, first_not_zeroed);
4306	if (err)
4307		goto failed_mount6;
4308
4309	err = ext4_register_sysfs(sb);
4310	if (err)
4311		goto failed_mount7;
4312
4313#ifdef CONFIG_QUOTA
4314	/* Enable quota usage during mount. */
4315	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4316		err = ext4_enable_quotas(sb);
4317		if (err)
4318			goto failed_mount8;
4319	}
4320#endif  /* CONFIG_QUOTA */
4321
4322	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4323	ext4_orphan_cleanup(sb, es);
4324	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4325	if (needs_recovery) {
4326		ext4_msg(sb, KERN_INFO, "recovery complete");
4327		ext4_mark_recovery_complete(sb, es);
4328	}
4329	if (EXT4_SB(sb)->s_journal) {
4330		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4331			descr = " journalled data mode";
4332		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4333			descr = " ordered data mode";
4334		else
4335			descr = " writeback data mode";
4336	} else
4337		descr = "out journal";
4338
4339	if (test_opt(sb, DISCARD)) {
4340		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4341		if (!blk_queue_discard(q))
4342			ext4_msg(sb, KERN_WARNING,
4343				 "mounting with \"discard\" option, but "
4344				 "the device does not support discard");
4345	}
4346
4347	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4348		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4349			 "Opts: %.*s%s%s", descr,
4350			 (int) sizeof(sbi->s_es->s_mount_opts),
4351			 sbi->s_es->s_mount_opts,
4352			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4353
4354	if (es->s_error_count)
4355		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4356
4357	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4358	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4359	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4360	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4361
4362	kfree(orig_data);
4363	return 0;
4364
4365cantfind_ext4:
4366	if (!silent)
4367		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4368	goto failed_mount;
4369
4370#ifdef CONFIG_QUOTA
4371failed_mount8:
4372	ext4_unregister_sysfs(sb);
4373#endif
4374failed_mount7:
4375	ext4_unregister_li_request(sb);
4376failed_mount6:
4377	ext4_mb_release(sb);
4378	if (sbi->s_flex_groups)
4379		kvfree(sbi->s_flex_groups);
4380	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4381	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4382	percpu_counter_destroy(&sbi->s_dirs_counter);
4383	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4384failed_mount5:
4385	ext4_ext_release(sb);
4386	ext4_release_system_zone(sb);
4387failed_mount4a:
4388	dput(sb->s_root);
4389	sb->s_root = NULL;
4390failed_mount4:
4391	ext4_msg(sb, KERN_ERR, "mount failed");
4392	if (EXT4_SB(sb)->rsv_conversion_wq)
4393		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4394failed_mount_wq:
4395	if (sbi->s_ea_inode_cache) {
4396		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4397		sbi->s_ea_inode_cache = NULL;
4398	}
4399	if (sbi->s_ea_block_cache) {
4400		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4401		sbi->s_ea_block_cache = NULL;
4402	}
4403	if (sbi->s_journal) {
4404		jbd2_journal_destroy(sbi->s_journal);
4405		sbi->s_journal = NULL;
4406	}
4407failed_mount3a:
4408	ext4_es_unregister_shrinker(sbi);
4409failed_mount3:
4410	del_timer_sync(&sbi->s_err_report);
4411	if (sbi->s_mmp_tsk)
4412		kthread_stop(sbi->s_mmp_tsk);
4413failed_mount2:
4414	for (i = 0; i < db_count; i++)
4415		brelse(sbi->s_group_desc[i]);
4416	kvfree(sbi->s_group_desc);
4417failed_mount:
4418	if (sbi->s_chksum_driver)
4419		crypto_free_shash(sbi->s_chksum_driver);
4420#ifdef CONFIG_QUOTA
4421	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4422		kfree(sbi->s_qf_names[i]);
4423#endif
4424	ext4_blkdev_remove(sbi);
4425	brelse(bh);
4426out_fail:
4427	sb->s_fs_info = NULL;
4428	kfree(sbi->s_blockgroup_lock);
4429out_free_base:
4430	kfree(sbi);
 
4431	kfree(orig_data);
4432	fs_put_dax(dax_dev);
4433	return err ? err : ret;
4434}
4435
4436/*
4437 * Setup any per-fs journal parameters now.  We'll do this both on
4438 * initial mount, once the journal has been initialised but before we've
4439 * done any recovery; and again on any subsequent remount.
4440 */
4441static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4442{
4443	struct ext4_sb_info *sbi = EXT4_SB(sb);
4444
4445	journal->j_commit_interval = sbi->s_commit_interval;
4446	journal->j_min_batch_time = sbi->s_min_batch_time;
4447	journal->j_max_batch_time = sbi->s_max_batch_time;
4448
4449	write_lock(&journal->j_state_lock);
4450	if (test_opt(sb, BARRIER))
4451		journal->j_flags |= JBD2_BARRIER;
4452	else
4453		journal->j_flags &= ~JBD2_BARRIER;
4454	if (test_opt(sb, DATA_ERR_ABORT))
4455		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4456	else
4457		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4458	write_unlock(&journal->j_state_lock);
4459}
4460
4461static struct inode *ext4_get_journal_inode(struct super_block *sb,
4462					     unsigned int journal_inum)
4463{
4464	struct inode *journal_inode;
 
 
 
 
 
 
 
4465
4466	/*
4467	 * Test for the existence of a valid inode on disk.  Bad things
4468	 * happen if we iget() an unused inode, as the subsequent iput()
4469	 * will try to delete it.
4470	 */
4471	journal_inode = ext4_iget(sb, journal_inum);
4472	if (IS_ERR(journal_inode)) {
4473		ext4_msg(sb, KERN_ERR, "no journal found");
4474		return NULL;
4475	}
4476	if (!journal_inode->i_nlink) {
4477		make_bad_inode(journal_inode);
4478		iput(journal_inode);
4479		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4480		return NULL;
4481	}
4482
4483	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4484		  journal_inode, journal_inode->i_size);
4485	if (!S_ISREG(journal_inode->i_mode)) {
4486		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4487		iput(journal_inode);
4488		return NULL;
4489	}
4490	return journal_inode;
4491}
4492
4493static journal_t *ext4_get_journal(struct super_block *sb,
4494				   unsigned int journal_inum)
4495{
4496	struct inode *journal_inode;
4497	journal_t *journal;
4498
4499	BUG_ON(!ext4_has_feature_journal(sb));
4500
4501	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4502	if (!journal_inode)
4503		return NULL;
4504
4505	journal = jbd2_journal_init_inode(journal_inode);
4506	if (!journal) {
4507		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4508		iput(journal_inode);
4509		return NULL;
4510	}
4511	journal->j_private = sb;
4512	ext4_init_journal_params(sb, journal);
4513	return journal;
4514}
4515
4516static journal_t *ext4_get_dev_journal(struct super_block *sb,
4517				       dev_t j_dev)
4518{
4519	struct buffer_head *bh;
4520	journal_t *journal;
4521	ext4_fsblk_t start;
4522	ext4_fsblk_t len;
4523	int hblock, blocksize;
4524	ext4_fsblk_t sb_block;
4525	unsigned long offset;
4526	struct ext4_super_block *es;
4527	struct block_device *bdev;
4528
4529	BUG_ON(!ext4_has_feature_journal(sb));
4530
4531	bdev = ext4_blkdev_get(j_dev, sb);
4532	if (bdev == NULL)
4533		return NULL;
4534
4535	blocksize = sb->s_blocksize;
4536	hblock = bdev_logical_block_size(bdev);
4537	if (blocksize < hblock) {
4538		ext4_msg(sb, KERN_ERR,
4539			"blocksize too small for journal device");
4540		goto out_bdev;
4541	}
4542
4543	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4544	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4545	set_blocksize(bdev, blocksize);
4546	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4547		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4548		       "external journal");
4549		goto out_bdev;
4550	}
4551
4552	es = (struct ext4_super_block *) (bh->b_data + offset);
4553	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4554	    !(le32_to_cpu(es->s_feature_incompat) &
4555	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4556		ext4_msg(sb, KERN_ERR, "external journal has "
4557					"bad superblock");
4558		brelse(bh);
4559		goto out_bdev;
4560	}
4561
4562	if ((le32_to_cpu(es->s_feature_ro_compat) &
4563	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4564	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4565		ext4_msg(sb, KERN_ERR, "external journal has "
4566				       "corrupt superblock");
4567		brelse(bh);
4568		goto out_bdev;
4569	}
4570
4571	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4572		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4573		brelse(bh);
4574		goto out_bdev;
4575	}
4576
4577	len = ext4_blocks_count(es);
4578	start = sb_block + 1;
4579	brelse(bh);	/* we're done with the superblock */
4580
4581	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4582					start, len, blocksize);
4583	if (!journal) {
4584		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4585		goto out_bdev;
4586	}
4587	journal->j_private = sb;
4588	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4589	wait_on_buffer(journal->j_sb_buffer);
4590	if (!buffer_uptodate(journal->j_sb_buffer)) {
4591		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4592		goto out_journal;
4593	}
4594	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4595		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4596					"user (unsupported) - %d",
4597			be32_to_cpu(journal->j_superblock->s_nr_users));
4598		goto out_journal;
4599	}
4600	EXT4_SB(sb)->journal_bdev = bdev;
4601	ext4_init_journal_params(sb, journal);
4602	return journal;
4603
4604out_journal:
4605	jbd2_journal_destroy(journal);
4606out_bdev:
4607	ext4_blkdev_put(bdev);
4608	return NULL;
4609}
4610
4611static int ext4_load_journal(struct super_block *sb,
4612			     struct ext4_super_block *es,
4613			     unsigned long journal_devnum)
4614{
4615	journal_t *journal;
4616	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4617	dev_t journal_dev;
4618	int err = 0;
4619	int really_read_only;
4620
4621	BUG_ON(!ext4_has_feature_journal(sb));
4622
4623	if (journal_devnum &&
4624	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4625		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4626			"numbers have changed");
4627		journal_dev = new_decode_dev(journal_devnum);
4628	} else
4629		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4630
4631	really_read_only = bdev_read_only(sb->s_bdev);
4632
4633	/*
4634	 * Are we loading a blank journal or performing recovery after a
4635	 * crash?  For recovery, we need to check in advance whether we
4636	 * can get read-write access to the device.
4637	 */
4638	if (ext4_has_feature_journal_needs_recovery(sb)) {
4639		if (sb_rdonly(sb)) {
4640			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4641					"required on readonly filesystem");
4642			if (really_read_only) {
4643				ext4_msg(sb, KERN_ERR, "write access "
4644					"unavailable, cannot proceed "
4645					"(try mounting with noload)");
4646				return -EROFS;
4647			}
4648			ext4_msg(sb, KERN_INFO, "write access will "
4649			       "be enabled during recovery");
4650		}
4651	}
4652
4653	if (journal_inum && journal_dev) {
4654		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4655		       "and inode journals!");
4656		return -EINVAL;
4657	}
4658
4659	if (journal_inum) {
4660		if (!(journal = ext4_get_journal(sb, journal_inum)))
4661			return -EINVAL;
4662	} else {
4663		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4664			return -EINVAL;
4665	}
4666
4667	if (!(journal->j_flags & JBD2_BARRIER))
4668		ext4_msg(sb, KERN_INFO, "barriers disabled");
4669
4670	if (!ext4_has_feature_journal_needs_recovery(sb))
4671		err = jbd2_journal_wipe(journal, !really_read_only);
4672	if (!err) {
4673		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4674		if (save)
4675			memcpy(save, ((char *) es) +
4676			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4677		err = jbd2_journal_load(journal);
4678		if (save)
4679			memcpy(((char *) es) + EXT4_S_ERR_START,
4680			       save, EXT4_S_ERR_LEN);
4681		kfree(save);
4682	}
4683
4684	if (err) {
4685		ext4_msg(sb, KERN_ERR, "error loading journal");
4686		jbd2_journal_destroy(journal);
4687		return err;
4688	}
4689
4690	EXT4_SB(sb)->s_journal = journal;
4691	ext4_clear_journal_err(sb, es);
4692
4693	if (!really_read_only && journal_devnum &&
4694	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4695		es->s_journal_dev = cpu_to_le32(journal_devnum);
4696
4697		/* Make sure we flush the recovery flag to disk. */
4698		ext4_commit_super(sb, 1);
4699	}
4700
4701	return 0;
4702}
4703
4704static int ext4_commit_super(struct super_block *sb, int sync)
4705{
4706	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4707	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4708	int error = 0;
4709
4710	if (!sbh || block_device_ejected(sb))
4711		return error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4712	/*
4713	 * If the file system is mounted read-only, don't update the
4714	 * superblock write time.  This avoids updating the superblock
4715	 * write time when we are mounting the root file system
4716	 * read/only but we need to replay the journal; at that point,
4717	 * for people who are east of GMT and who make their clock
4718	 * tick in localtime for Windows bug-for-bug compatibility,
4719	 * the clock is set in the future, and this will cause e2fsck
4720	 * to complain and force a full file system check.
4721	 */
4722	if (!(sb->s_flags & SB_RDONLY))
4723		es->s_wtime = cpu_to_le32(get_seconds());
4724	if (sb->s_bdev->bd_part)
4725		es->s_kbytes_written =
4726			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4727			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4728			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4729	else
4730		es->s_kbytes_written =
4731			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4732	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4733		ext4_free_blocks_count_set(es,
4734			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4735				&EXT4_SB(sb)->s_freeclusters_counter)));
4736	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4737		es->s_free_inodes_count =
4738			cpu_to_le32(percpu_counter_sum_positive(
4739				&EXT4_SB(sb)->s_freeinodes_counter));
4740	BUFFER_TRACE(sbh, "marking dirty");
4741	ext4_superblock_csum_set(sb);
4742	if (sync)
4743		lock_buffer(sbh);
4744	if (buffer_write_io_error(sbh)) {
4745		/*
4746		 * Oh, dear.  A previous attempt to write the
4747		 * superblock failed.  This could happen because the
4748		 * USB device was yanked out.  Or it could happen to
4749		 * be a transient write error and maybe the block will
4750		 * be remapped.  Nothing we can do but to retry the
4751		 * write and hope for the best.
4752		 */
4753		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4754		       "superblock detected");
4755		clear_buffer_write_io_error(sbh);
4756		set_buffer_uptodate(sbh);
4757	}
4758	mark_buffer_dirty(sbh);
4759	if (sync) {
4760		unlock_buffer(sbh);
4761		error = __sync_dirty_buffer(sbh,
4762			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4763		if (error)
4764			return error;
4765
4766		error = buffer_write_io_error(sbh);
4767		if (error) {
4768			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4769			       "superblock");
4770			clear_buffer_write_io_error(sbh);
4771			set_buffer_uptodate(sbh);
4772		}
4773	}
4774	return error;
4775}
4776
4777/*
4778 * Have we just finished recovery?  If so, and if we are mounting (or
4779 * remounting) the filesystem readonly, then we will end up with a
4780 * consistent fs on disk.  Record that fact.
4781 */
4782static void ext4_mark_recovery_complete(struct super_block *sb,
4783					struct ext4_super_block *es)
4784{
4785	journal_t *journal = EXT4_SB(sb)->s_journal;
4786
4787	if (!ext4_has_feature_journal(sb)) {
4788		BUG_ON(journal != NULL);
4789		return;
4790	}
4791	jbd2_journal_lock_updates(journal);
4792	if (jbd2_journal_flush(journal) < 0)
4793		goto out;
4794
4795	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
 
4796		ext4_clear_feature_journal_needs_recovery(sb);
4797		ext4_commit_super(sb, 1);
4798	}
4799
4800out:
4801	jbd2_journal_unlock_updates(journal);
4802}
4803
4804/*
4805 * If we are mounting (or read-write remounting) a filesystem whose journal
4806 * has recorded an error from a previous lifetime, move that error to the
4807 * main filesystem now.
4808 */
4809static void ext4_clear_journal_err(struct super_block *sb,
4810				   struct ext4_super_block *es)
4811{
4812	journal_t *journal;
4813	int j_errno;
4814	const char *errstr;
4815
4816	BUG_ON(!ext4_has_feature_journal(sb));
4817
4818	journal = EXT4_SB(sb)->s_journal;
4819
4820	/*
4821	 * Now check for any error status which may have been recorded in the
4822	 * journal by a prior ext4_error() or ext4_abort()
4823	 */
4824
4825	j_errno = jbd2_journal_errno(journal);
4826	if (j_errno) {
4827		char nbuf[16];
4828
4829		errstr = ext4_decode_error(sb, j_errno, nbuf);
4830		ext4_warning(sb, "Filesystem error recorded "
4831			     "from previous mount: %s", errstr);
4832		ext4_warning(sb, "Marking fs in need of filesystem check.");
4833
4834		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4835		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4836		ext4_commit_super(sb, 1);
4837
4838		jbd2_journal_clear_err(journal);
4839		jbd2_journal_update_sb_errno(journal);
4840	}
4841}
4842
4843/*
4844 * Force the running and committing transactions to commit,
4845 * and wait on the commit.
4846 */
4847int ext4_force_commit(struct super_block *sb)
4848{
4849	journal_t *journal;
4850
4851	if (sb_rdonly(sb))
4852		return 0;
4853
4854	journal = EXT4_SB(sb)->s_journal;
4855	return ext4_journal_force_commit(journal);
4856}
4857
4858static int ext4_sync_fs(struct super_block *sb, int wait)
4859{
4860	int ret = 0;
4861	tid_t target;
4862	bool needs_barrier = false;
4863	struct ext4_sb_info *sbi = EXT4_SB(sb);
4864
4865	if (unlikely(ext4_forced_shutdown(sbi)))
4866		return 0;
4867
4868	trace_ext4_sync_fs(sb, wait);
4869	flush_workqueue(sbi->rsv_conversion_wq);
4870	/*
4871	 * Writeback quota in non-journalled quota case - journalled quota has
4872	 * no dirty dquots
4873	 */
4874	dquot_writeback_dquots(sb, -1);
4875	/*
4876	 * Data writeback is possible w/o journal transaction, so barrier must
4877	 * being sent at the end of the function. But we can skip it if
4878	 * transaction_commit will do it for us.
4879	 */
4880	if (sbi->s_journal) {
4881		target = jbd2_get_latest_transaction(sbi->s_journal);
4882		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4883		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4884			needs_barrier = true;
4885
4886		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4887			if (wait)
4888				ret = jbd2_log_wait_commit(sbi->s_journal,
4889							   target);
4890		}
4891	} else if (wait && test_opt(sb, BARRIER))
4892		needs_barrier = true;
4893	if (needs_barrier) {
4894		int err;
4895		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4896		if (!ret)
4897			ret = err;
4898	}
4899
4900	return ret;
4901}
4902
4903/*
4904 * LVM calls this function before a (read-only) snapshot is created.  This
4905 * gives us a chance to flush the journal completely and mark the fs clean.
4906 *
4907 * Note that only this function cannot bring a filesystem to be in a clean
4908 * state independently. It relies on upper layer to stop all data & metadata
4909 * modifications.
4910 */
4911static int ext4_freeze(struct super_block *sb)
4912{
4913	int error = 0;
4914	journal_t *journal;
4915
4916	if (sb_rdonly(sb))
4917		return 0;
4918
4919	journal = EXT4_SB(sb)->s_journal;
4920
4921	if (journal) {
4922		/* Now we set up the journal barrier. */
4923		jbd2_journal_lock_updates(journal);
4924
4925		/*
4926		 * Don't clear the needs_recovery flag if we failed to
4927		 * flush the journal.
4928		 */
4929		error = jbd2_journal_flush(journal);
4930		if (error < 0)
4931			goto out;
4932
4933		/* Journal blocked and flushed, clear needs_recovery flag. */
4934		ext4_clear_feature_journal_needs_recovery(sb);
4935	}
4936
4937	error = ext4_commit_super(sb, 1);
4938out:
4939	if (journal)
4940		/* we rely on upper layer to stop further updates */
4941		jbd2_journal_unlock_updates(journal);
4942	return error;
4943}
4944
4945/*
4946 * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4947 * flag here, even though the filesystem is not technically dirty yet.
4948 */
4949static int ext4_unfreeze(struct super_block *sb)
4950{
4951	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
4952		return 0;
4953
4954	if (EXT4_SB(sb)->s_journal) {
4955		/* Reset the needs_recovery flag before the fs is unlocked. */
4956		ext4_set_feature_journal_needs_recovery(sb);
4957	}
4958
4959	ext4_commit_super(sb, 1);
4960	return 0;
4961}
4962
4963/*
4964 * Structure to save mount options for ext4_remount's benefit
4965 */
4966struct ext4_mount_options {
4967	unsigned long s_mount_opt;
4968	unsigned long s_mount_opt2;
4969	kuid_t s_resuid;
4970	kgid_t s_resgid;
4971	unsigned long s_commit_interval;
4972	u32 s_min_batch_time, s_max_batch_time;
4973#ifdef CONFIG_QUOTA
4974	int s_jquota_fmt;
4975	char *s_qf_names[EXT4_MAXQUOTAS];
4976#endif
4977};
4978
4979static int ext4_remount(struct super_block *sb, int *flags, char *data)
4980{
4981	struct ext4_super_block *es;
4982	struct ext4_sb_info *sbi = EXT4_SB(sb);
4983	unsigned long old_sb_flags;
4984	struct ext4_mount_options old_opts;
4985	int enable_quota = 0;
4986	ext4_group_t g;
4987	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4988	int err = 0;
4989#ifdef CONFIG_QUOTA
4990	int i, j;
4991#endif
4992	char *orig_data = kstrdup(data, GFP_KERNEL);
4993
4994	/* Store the original options */
4995	old_sb_flags = sb->s_flags;
4996	old_opts.s_mount_opt = sbi->s_mount_opt;
4997	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4998	old_opts.s_resuid = sbi->s_resuid;
4999	old_opts.s_resgid = sbi->s_resgid;
5000	old_opts.s_commit_interval = sbi->s_commit_interval;
5001	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5002	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5003#ifdef CONFIG_QUOTA
5004	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5005	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5006		if (sbi->s_qf_names[i]) {
5007			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
5008							 GFP_KERNEL);
5009			if (!old_opts.s_qf_names[i]) {
5010				for (j = 0; j < i; j++)
5011					kfree(old_opts.s_qf_names[j]);
5012				kfree(orig_data);
5013				return -ENOMEM;
5014			}
5015		} else
5016			old_opts.s_qf_names[i] = NULL;
5017#endif
5018	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5019		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5020
5021	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5022		err = -EINVAL;
5023		goto restore_opts;
5024	}
5025
5026	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5027	    test_opt(sb, JOURNAL_CHECKSUM)) {
5028		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5029			 "during remount not supported; ignoring");
5030		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5031	}
5032
5033	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5034		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5035			ext4_msg(sb, KERN_ERR, "can't mount with "
5036				 "both data=journal and delalloc");
5037			err = -EINVAL;
5038			goto restore_opts;
5039		}
5040		if (test_opt(sb, DIOREAD_NOLOCK)) {
5041			ext4_msg(sb, KERN_ERR, "can't mount with "
5042				 "both data=journal and dioread_nolock");
5043			err = -EINVAL;
5044			goto restore_opts;
5045		}
5046		if (test_opt(sb, DAX)) {
5047			ext4_msg(sb, KERN_ERR, "can't mount with "
5048				 "both data=journal and dax");
5049			err = -EINVAL;
5050			goto restore_opts;
5051		}
5052	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5053		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5054			ext4_msg(sb, KERN_ERR, "can't mount with "
5055				"journal_async_commit in data=ordered mode");
5056			err = -EINVAL;
5057			goto restore_opts;
5058		}
5059	}
5060
5061	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5062		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5063		err = -EINVAL;
5064		goto restore_opts;
5065	}
5066
5067	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5068		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5069			"dax flag with busy inodes while remounting");
5070		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5071	}
5072
5073	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5074		ext4_abort(sb, "Abort forced by user");
5075
5076	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5077		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5078
5079	es = sbi->s_es;
5080
5081	if (sbi->s_journal) {
5082		ext4_init_journal_params(sb, sbi->s_journal);
5083		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5084	}
5085
5086	if (*flags & SB_LAZYTIME)
5087		sb->s_flags |= SB_LAZYTIME;
5088
5089	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5090		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5091			err = -EROFS;
5092			goto restore_opts;
5093		}
5094
5095		if (*flags & SB_RDONLY) {
5096			err = sync_filesystem(sb);
5097			if (err < 0)
5098				goto restore_opts;
5099			err = dquot_suspend(sb, -1);
5100			if (err < 0)
5101				goto restore_opts;
5102
5103			/*
5104			 * First of all, the unconditional stuff we have to do
5105			 * to disable replay of the journal when we next remount
5106			 */
5107			sb->s_flags |= SB_RDONLY;
5108
5109			/*
5110			 * OK, test if we are remounting a valid rw partition
5111			 * readonly, and if so set the rdonly flag and then
5112			 * mark the partition as valid again.
5113			 */
5114			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5115			    (sbi->s_mount_state & EXT4_VALID_FS))
5116				es->s_state = cpu_to_le16(sbi->s_mount_state);
5117
5118			if (sbi->s_journal)
5119				ext4_mark_recovery_complete(sb, es);
5120		} else {
5121			/* Make sure we can mount this feature set readwrite */
5122			if (ext4_has_feature_readonly(sb) ||
5123			    !ext4_feature_set_ok(sb, 0)) {
5124				err = -EROFS;
5125				goto restore_opts;
5126			}
5127			/*
5128			 * Make sure the group descriptor checksums
5129			 * are sane.  If they aren't, refuse to remount r/w.
5130			 */
5131			for (g = 0; g < sbi->s_groups_count; g++) {
5132				struct ext4_group_desc *gdp =
5133					ext4_get_group_desc(sb, g, NULL);
5134
5135				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5136					ext4_msg(sb, KERN_ERR,
5137	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5138		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5139					       le16_to_cpu(gdp->bg_checksum));
5140					err = -EFSBADCRC;
5141					goto restore_opts;
5142				}
5143			}
5144
5145			/*
5146			 * If we have an unprocessed orphan list hanging
5147			 * around from a previously readonly bdev mount,
5148			 * require a full umount/remount for now.
5149			 */
5150			if (es->s_last_orphan) {
5151				ext4_msg(sb, KERN_WARNING, "Couldn't "
5152				       "remount RDWR because of unprocessed "
5153				       "orphan inode list.  Please "
5154				       "umount/remount instead");
5155				err = -EINVAL;
5156				goto restore_opts;
5157			}
5158
5159			/*
5160			 * Mounting a RDONLY partition read-write, so reread
5161			 * and store the current valid flag.  (It may have
5162			 * been changed by e2fsck since we originally mounted
5163			 * the partition.)
5164			 */
5165			if (sbi->s_journal)
5166				ext4_clear_journal_err(sb, es);
5167			sbi->s_mount_state = le16_to_cpu(es->s_state);
5168			if (!ext4_setup_super(sb, es, 0))
5169				sb->s_flags &= ~SB_RDONLY;
5170			if (ext4_has_feature_mmp(sb))
5171				if (ext4_multi_mount_protect(sb,
5172						le64_to_cpu(es->s_mmp_block))) {
5173					err = -EROFS;
5174					goto restore_opts;
5175				}
5176			enable_quota = 1;
5177		}
5178	}
5179
5180	/*
5181	 * Reinitialize lazy itable initialization thread based on
5182	 * current settings
5183	 */
5184	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5185		ext4_unregister_li_request(sb);
5186	else {
5187		ext4_group_t first_not_zeroed;
5188		first_not_zeroed = ext4_has_uninit_itable(sb);
5189		ext4_register_li_request(sb, first_not_zeroed);
5190	}
5191
5192	ext4_setup_system_zone(sb);
5193	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
5194		ext4_commit_super(sb, 1);
5195
5196#ifdef CONFIG_QUOTA
5197	/* Release old quota file names */
5198	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5199		kfree(old_opts.s_qf_names[i]);
5200	if (enable_quota) {
5201		if (sb_any_quota_suspended(sb))
5202			dquot_resume(sb, -1);
5203		else if (ext4_has_feature_quota(sb)) {
5204			err = ext4_enable_quotas(sb);
5205			if (err)
5206				goto restore_opts;
5207		}
5208	}
5209#endif
5210
5211	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5212	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5213	kfree(orig_data);
5214	return 0;
5215
5216restore_opts:
5217	sb->s_flags = old_sb_flags;
5218	sbi->s_mount_opt = old_opts.s_mount_opt;
5219	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5220	sbi->s_resuid = old_opts.s_resuid;
5221	sbi->s_resgid = old_opts.s_resgid;
5222	sbi->s_commit_interval = old_opts.s_commit_interval;
5223	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5224	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5225#ifdef CONFIG_QUOTA
5226	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5227	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5228		kfree(sbi->s_qf_names[i]);
5229		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5230	}
5231#endif
5232	kfree(orig_data);
5233	return err;
5234}
5235
5236#ifdef CONFIG_QUOTA
5237static int ext4_statfs_project(struct super_block *sb,
5238			       kprojid_t projid, struct kstatfs *buf)
5239{
5240	struct kqid qid;
5241	struct dquot *dquot;
5242	u64 limit;
5243	u64 curblock;
5244
5245	qid = make_kqid_projid(projid);
5246	dquot = dqget(sb, qid);
5247	if (IS_ERR(dquot))
5248		return PTR_ERR(dquot);
5249	spin_lock(&dquot->dq_dqb_lock);
5250
5251	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5252		 dquot->dq_dqb.dqb_bsoftlimit :
5253		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5254	if (limit && buf->f_blocks > limit) {
5255		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5256		buf->f_blocks = limit;
5257		buf->f_bfree = buf->f_bavail =
5258			(buf->f_blocks > curblock) ?
5259			 (buf->f_blocks - curblock) : 0;
5260	}
5261
5262	limit = dquot->dq_dqb.dqb_isoftlimit ?
5263		dquot->dq_dqb.dqb_isoftlimit :
5264		dquot->dq_dqb.dqb_ihardlimit;
5265	if (limit && buf->f_files > limit) {
5266		buf->f_files = limit;
5267		buf->f_ffree =
5268			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5269			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5270	}
5271
5272	spin_unlock(&dquot->dq_dqb_lock);
5273	dqput(dquot);
5274	return 0;
5275}
5276#endif
5277
5278static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5279{
5280	struct super_block *sb = dentry->d_sb;
5281	struct ext4_sb_info *sbi = EXT4_SB(sb);
5282	struct ext4_super_block *es = sbi->s_es;
5283	ext4_fsblk_t overhead = 0, resv_blocks;
5284	u64 fsid;
5285	s64 bfree;
5286	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5287
5288	if (!test_opt(sb, MINIX_DF))
5289		overhead = sbi->s_overhead;
5290
5291	buf->f_type = EXT4_SUPER_MAGIC;
5292	buf->f_bsize = sb->s_blocksize;
5293	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5294	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5295		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5296	/* prevent underflow in case that few free space is available */
5297	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5298	buf->f_bavail = buf->f_bfree -
5299			(ext4_r_blocks_count(es) + resv_blocks);
5300	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5301		buf->f_bavail = 0;
5302	buf->f_files = le32_to_cpu(es->s_inodes_count);
5303	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5304	buf->f_namelen = EXT4_NAME_LEN;
5305	fsid = le64_to_cpup((void *)es->s_uuid) ^
5306	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5307	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5308	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5309
5310#ifdef CONFIG_QUOTA
5311	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5312	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5313		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5314#endif
5315	return 0;
5316}
5317
 
 
 
 
 
 
 
 
 
5318
5319#ifdef CONFIG_QUOTA
5320
5321/*
5322 * Helper functions so that transaction is started before we acquire dqio_sem
5323 * to keep correct lock ordering of transaction > dqio_sem
5324 */
5325static inline struct inode *dquot_to_inode(struct dquot *dquot)
5326{
5327	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5328}
5329
5330static int ext4_write_dquot(struct dquot *dquot)
5331{
5332	int ret, err;
5333	handle_t *handle;
5334	struct inode *inode;
5335
5336	inode = dquot_to_inode(dquot);
5337	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5338				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5339	if (IS_ERR(handle))
5340		return PTR_ERR(handle);
5341	ret = dquot_commit(dquot);
5342	err = ext4_journal_stop(handle);
5343	if (!ret)
5344		ret = err;
5345	return ret;
5346}
5347
5348static int ext4_acquire_dquot(struct dquot *dquot)
5349{
5350	int ret, err;
5351	handle_t *handle;
5352
5353	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5354				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5355	if (IS_ERR(handle))
5356		return PTR_ERR(handle);
5357	ret = dquot_acquire(dquot);
5358	err = ext4_journal_stop(handle);
5359	if (!ret)
5360		ret = err;
5361	return ret;
5362}
5363
5364static int ext4_release_dquot(struct dquot *dquot)
5365{
5366	int ret, err;
5367	handle_t *handle;
5368
5369	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5370				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5371	if (IS_ERR(handle)) {
5372		/* Release dquot anyway to avoid endless cycle in dqput() */
5373		dquot_release(dquot);
5374		return PTR_ERR(handle);
5375	}
5376	ret = dquot_release(dquot);
5377	err = ext4_journal_stop(handle);
5378	if (!ret)
5379		ret = err;
5380	return ret;
5381}
5382
5383static int ext4_mark_dquot_dirty(struct dquot *dquot)
5384{
5385	struct super_block *sb = dquot->dq_sb;
5386	struct ext4_sb_info *sbi = EXT4_SB(sb);
5387
5388	/* Are we journaling quotas? */
5389	if (ext4_has_feature_quota(sb) ||
5390	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5391		dquot_mark_dquot_dirty(dquot);
5392		return ext4_write_dquot(dquot);
5393	} else {
5394		return dquot_mark_dquot_dirty(dquot);
5395	}
5396}
5397
5398static int ext4_write_info(struct super_block *sb, int type)
5399{
5400	int ret, err;
5401	handle_t *handle;
5402
5403	/* Data block + inode block */
5404	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5405	if (IS_ERR(handle))
5406		return PTR_ERR(handle);
5407	ret = dquot_commit_info(sb, type);
5408	err = ext4_journal_stop(handle);
5409	if (!ret)
5410		ret = err;
5411	return ret;
5412}
5413
5414/*
5415 * Turn on quotas during mount time - we need to find
5416 * the quota file and such...
5417 */
5418static int ext4_quota_on_mount(struct super_block *sb, int type)
5419{
5420	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5421					EXT4_SB(sb)->s_jquota_fmt, type);
5422}
5423
5424static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5425{
5426	struct ext4_inode_info *ei = EXT4_I(inode);
5427
5428	/* The first argument of lockdep_set_subclass has to be
5429	 * *exactly* the same as the argument to init_rwsem() --- in
5430	 * this case, in init_once() --- or lockdep gets unhappy
5431	 * because the name of the lock is set using the
5432	 * stringification of the argument to init_rwsem().
5433	 */
5434	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5435	lockdep_set_subclass(&ei->i_data_sem, subclass);
5436}
5437
5438/*
5439 * Standard function to be called on quota_on
5440 */
5441static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5442			 const struct path *path)
5443{
5444	int err;
5445
5446	if (!test_opt(sb, QUOTA))
5447		return -EINVAL;
5448
5449	/* Quotafile not on the same filesystem? */
5450	if (path->dentry->d_sb != sb)
5451		return -EXDEV;
5452	/* Journaling quota? */
5453	if (EXT4_SB(sb)->s_qf_names[type]) {
5454		/* Quotafile not in fs root? */
5455		if (path->dentry->d_parent != sb->s_root)
5456			ext4_msg(sb, KERN_WARNING,
5457				"Quota file not on filesystem root. "
5458				"Journaled quota will not work");
5459		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5460	} else {
5461		/*
5462		 * Clear the flag just in case mount options changed since
5463		 * last time.
5464		 */
5465		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5466	}
5467
5468	/*
5469	 * When we journal data on quota file, we have to flush journal to see
5470	 * all updates to the file when we bypass pagecache...
5471	 */
5472	if (EXT4_SB(sb)->s_journal &&
5473	    ext4_should_journal_data(d_inode(path->dentry))) {
5474		/*
5475		 * We don't need to lock updates but journal_flush() could
5476		 * otherwise be livelocked...
5477		 */
5478		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5479		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5480		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5481		if (err)
5482			return err;
5483	}
5484
5485	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5486	err = dquot_quota_on(sb, type, format_id, path);
5487	if (err) {
5488		lockdep_set_quota_inode(path->dentry->d_inode,
5489					     I_DATA_SEM_NORMAL);
5490	} else {
5491		struct inode *inode = d_inode(path->dentry);
5492		handle_t *handle;
5493
5494		/*
5495		 * Set inode flags to prevent userspace from messing with quota
5496		 * files. If this fails, we return success anyway since quotas
5497		 * are already enabled and this is not a hard failure.
5498		 */
5499		inode_lock(inode);
5500		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5501		if (IS_ERR(handle))
5502			goto unlock_inode;
5503		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5504		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5505				S_NOATIME | S_IMMUTABLE);
5506		ext4_mark_inode_dirty(handle, inode);
5507		ext4_journal_stop(handle);
5508	unlock_inode:
5509		inode_unlock(inode);
5510	}
5511	return err;
5512}
5513
5514static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5515			     unsigned int flags)
5516{
5517	int err;
5518	struct inode *qf_inode;
5519	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5520		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5521		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5522		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5523	};
5524
5525	BUG_ON(!ext4_has_feature_quota(sb));
5526
5527	if (!qf_inums[type])
5528		return -EPERM;
5529
5530	qf_inode = ext4_iget(sb, qf_inums[type]);
5531	if (IS_ERR(qf_inode)) {
5532		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5533		return PTR_ERR(qf_inode);
5534	}
5535
5536	/* Don't account quota for quota files to avoid recursion */
5537	qf_inode->i_flags |= S_NOQUOTA;
5538	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5539	err = dquot_enable(qf_inode, type, format_id, flags);
5540	iput(qf_inode);
5541	if (err)
5542		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5543
5544	return err;
5545}
5546
5547/* Enable usage tracking for all quota types. */
5548static int ext4_enable_quotas(struct super_block *sb)
5549{
5550	int type, err = 0;
5551	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5552		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5553		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5554		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5555	};
5556	bool quota_mopt[EXT4_MAXQUOTAS] = {
5557		test_opt(sb, USRQUOTA),
5558		test_opt(sb, GRPQUOTA),
5559		test_opt(sb, PRJQUOTA),
5560	};
5561
5562	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5563	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5564		if (qf_inums[type]) {
5565			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5566				DQUOT_USAGE_ENABLED |
5567				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5568			if (err) {
5569				for (type--; type >= 0; type--)
5570					dquot_quota_off(sb, type);
5571
5572				ext4_warning(sb,
5573					"Failed to enable quota tracking "
5574					"(type=%d, err=%d). Please run "
5575					"e2fsck to fix.", type, err);
5576				return err;
5577			}
5578		}
5579	}
5580	return 0;
5581}
5582
5583static int ext4_quota_off(struct super_block *sb, int type)
5584{
5585	struct inode *inode = sb_dqopt(sb)->files[type];
5586	handle_t *handle;
5587	int err;
5588
5589	/* Force all delayed allocation blocks to be allocated.
5590	 * Caller already holds s_umount sem */
5591	if (test_opt(sb, DELALLOC))
5592		sync_filesystem(sb);
5593
5594	if (!inode || !igrab(inode))
5595		goto out;
5596
5597	err = dquot_quota_off(sb, type);
5598	if (err || ext4_has_feature_quota(sb))
5599		goto out_put;
5600
5601	inode_lock(inode);
5602	/*
5603	 * Update modification times of quota files when userspace can
5604	 * start looking at them. If we fail, we return success anyway since
5605	 * this is not a hard failure and quotas are already disabled.
5606	 */
5607	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5608	if (IS_ERR(handle))
5609		goto out_unlock;
5610	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5611	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5612	inode->i_mtime = inode->i_ctime = current_time(inode);
5613	ext4_mark_inode_dirty(handle, inode);
5614	ext4_journal_stop(handle);
5615out_unlock:
5616	inode_unlock(inode);
5617out_put:
5618	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5619	iput(inode);
5620	return err;
5621out:
5622	return dquot_quota_off(sb, type);
5623}
5624
5625/* Read data from quotafile - avoid pagecache and such because we cannot afford
5626 * acquiring the locks... As quota files are never truncated and quota code
5627 * itself serializes the operations (and no one else should touch the files)
5628 * we don't have to be afraid of races */
5629static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5630			       size_t len, loff_t off)
5631{
5632	struct inode *inode = sb_dqopt(sb)->files[type];
5633	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5634	int offset = off & (sb->s_blocksize - 1);
5635	int tocopy;
5636	size_t toread;
5637	struct buffer_head *bh;
5638	loff_t i_size = i_size_read(inode);
5639
5640	if (off > i_size)
5641		return 0;
5642	if (off+len > i_size)
5643		len = i_size-off;
5644	toread = len;
5645	while (toread > 0) {
5646		tocopy = sb->s_blocksize - offset < toread ?
5647				sb->s_blocksize - offset : toread;
5648		bh = ext4_bread(NULL, inode, blk, 0);
5649		if (IS_ERR(bh))
5650			return PTR_ERR(bh);
5651		if (!bh)	/* A hole? */
5652			memset(data, 0, tocopy);
5653		else
5654			memcpy(data, bh->b_data+offset, tocopy);
5655		brelse(bh);
5656		offset = 0;
5657		toread -= tocopy;
5658		data += tocopy;
5659		blk++;
5660	}
5661	return len;
5662}
5663
5664/* Write to quotafile (we know the transaction is already started and has
5665 * enough credits) */
5666static ssize_t ext4_quota_write(struct super_block *sb, int type,
5667				const char *data, size_t len, loff_t off)
5668{
5669	struct inode *inode = sb_dqopt(sb)->files[type];
5670	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5671	int err, offset = off & (sb->s_blocksize - 1);
5672	int retries = 0;
5673	struct buffer_head *bh;
5674	handle_t *handle = journal_current_handle();
5675
5676	if (EXT4_SB(sb)->s_journal && !handle) {
5677		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5678			" cancelled because transaction is not started",
5679			(unsigned long long)off, (unsigned long long)len);
5680		return -EIO;
5681	}
5682	/*
5683	 * Since we account only one data block in transaction credits,
5684	 * then it is impossible to cross a block boundary.
5685	 */
5686	if (sb->s_blocksize - offset < len) {
5687		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5688			" cancelled because not block aligned",
5689			(unsigned long long)off, (unsigned long long)len);
5690		return -EIO;
5691	}
5692
5693	do {
5694		bh = ext4_bread(handle, inode, blk,
5695				EXT4_GET_BLOCKS_CREATE |
5696				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5697	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5698		 ext4_should_retry_alloc(inode->i_sb, &retries));
5699	if (IS_ERR(bh))
5700		return PTR_ERR(bh);
5701	if (!bh)
5702		goto out;
5703	BUFFER_TRACE(bh, "get write access");
5704	err = ext4_journal_get_write_access(handle, bh);
5705	if (err) {
5706		brelse(bh);
5707		return err;
5708	}
5709	lock_buffer(bh);
5710	memcpy(bh->b_data+offset, data, len);
5711	flush_dcache_page(bh->b_page);
5712	unlock_buffer(bh);
5713	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5714	brelse(bh);
5715out:
5716	if (inode->i_size < off + len) {
5717		i_size_write(inode, off + len);
5718		EXT4_I(inode)->i_disksize = inode->i_size;
5719		ext4_mark_inode_dirty(handle, inode);
5720	}
5721	return len;
5722}
5723
5724static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5725{
5726	const struct quota_format_ops	*ops;
5727
5728	if (!sb_has_quota_loaded(sb, qid->type))
5729		return -ESRCH;
5730	ops = sb_dqopt(sb)->ops[qid->type];
5731	if (!ops || !ops->get_next_id)
5732		return -ENOSYS;
5733	return dquot_get_next_id(sb, qid);
5734}
5735#endif
5736
5737static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5738		       const char *dev_name, void *data)
5739{
5740	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5741}
5742
5743#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5744static inline void register_as_ext2(void)
5745{
5746	int err = register_filesystem(&ext2_fs_type);
5747	if (err)
5748		printk(KERN_WARNING
5749		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5750}
5751
5752static inline void unregister_as_ext2(void)
5753{
5754	unregister_filesystem(&ext2_fs_type);
5755}
5756
5757static inline int ext2_feature_set_ok(struct super_block *sb)
5758{
5759	if (ext4_has_unknown_ext2_incompat_features(sb))
5760		return 0;
5761	if (sb_rdonly(sb))
5762		return 1;
5763	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5764		return 0;
5765	return 1;
5766}
5767#else
5768static inline void register_as_ext2(void) { }
5769static inline void unregister_as_ext2(void) { }
5770static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5771#endif
5772
5773static inline void register_as_ext3(void)
5774{
5775	int err = register_filesystem(&ext3_fs_type);
5776	if (err)
5777		printk(KERN_WARNING
5778		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5779}
5780
5781static inline void unregister_as_ext3(void)
5782{
5783	unregister_filesystem(&ext3_fs_type);
5784}
5785
5786static inline int ext3_feature_set_ok(struct super_block *sb)
5787{
5788	if (ext4_has_unknown_ext3_incompat_features(sb))
5789		return 0;
5790	if (!ext4_has_feature_journal(sb))
5791		return 0;
5792	if (sb_rdonly(sb))
5793		return 1;
5794	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5795		return 0;
5796	return 1;
5797}
5798
5799static struct file_system_type ext4_fs_type = {
5800	.owner		= THIS_MODULE,
5801	.name		= "ext4",
5802	.mount		= ext4_mount,
5803	.kill_sb	= kill_block_super,
5804	.fs_flags	= FS_REQUIRES_DEV,
5805};
5806MODULE_ALIAS_FS("ext4");
5807
5808/* Shared across all ext4 file systems */
5809wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5810
5811static int __init ext4_init_fs(void)
5812{
5813	int i, err;
5814
5815	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5816	ext4_li_info = NULL;
5817	mutex_init(&ext4_li_mtx);
5818
5819	/* Build-time check for flags consistency */
5820	ext4_check_flag_values();
5821
5822	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5823		init_waitqueue_head(&ext4__ioend_wq[i]);
5824
5825	err = ext4_init_es();
5826	if (err)
5827		return err;
5828
5829	err = ext4_init_pageio();
5830	if (err)
5831		goto out5;
5832
5833	err = ext4_init_system_zone();
5834	if (err)
5835		goto out4;
5836
5837	err = ext4_init_sysfs();
5838	if (err)
5839		goto out3;
5840
5841	err = ext4_init_mballoc();
5842	if (err)
5843		goto out2;
5844	err = init_inodecache();
5845	if (err)
5846		goto out1;
5847	register_as_ext3();
5848	register_as_ext2();
5849	err = register_filesystem(&ext4_fs_type);
5850	if (err)
5851		goto out;
5852
5853	return 0;
5854out:
5855	unregister_as_ext2();
5856	unregister_as_ext3();
5857	destroy_inodecache();
5858out1:
5859	ext4_exit_mballoc();
5860out2:
5861	ext4_exit_sysfs();
5862out3:
5863	ext4_exit_system_zone();
5864out4:
5865	ext4_exit_pageio();
5866out5:
5867	ext4_exit_es();
5868
5869	return err;
5870}
5871
5872static void __exit ext4_exit_fs(void)
5873{
 
5874	ext4_destroy_lazyinit_thread();
5875	unregister_as_ext2();
5876	unregister_as_ext3();
5877	unregister_filesystem(&ext4_fs_type);
5878	destroy_inodecache();
5879	ext4_exit_mballoc();
5880	ext4_exit_sysfs();
5881	ext4_exit_system_zone();
5882	ext4_exit_pageio();
5883	ext4_exit_es();
5884}
5885
5886MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5887MODULE_DESCRIPTION("Fourth Extended Filesystem");
5888MODULE_LICENSE("GPL");
5889MODULE_SOFTDEP("pre: crc32c");
5890module_init(ext4_init_fs)
5891module_exit(ext4_exit_fs)