1 files changed, 197 insertions, 87 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 22546ad7f0ae..cc5c157aa11d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -38,6 +38,7 @@
 #include <linux/ctype.h>
 #include <linux/log2.h>
 #include <linux/crc16.h>
+#include <linux/cleancache.h>
 #include <asm/uaccess.h>
 
 #include <linux/kthread.h>
@@ -75,11 +76,27 @@ static void ext4_write_super(struct super_block *sb);
 static int ext4_freeze(struct super_block *sb);
 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
 		       const char *dev_name, void *data);
+static inline int ext2_feature_set_ok(struct super_block *sb);
+static inline int ext3_feature_set_ok(struct super_block *sb);
 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
 static void ext4_destroy_lazyinit_thread(void);
 static void ext4_unregister_li_request(struct super_block *sb);
 static void ext4_clear_request_list(void);
 
+#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
+static struct file_system_type ext2_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "ext2",
+	.mount		= ext4_mount,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+#define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
+#else
+#define IS_EXT2_SB(sb) (0)
+#endif
+
+
 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 static struct file_system_type ext3_fs_type = {
 	.owner		= THIS_MODULE,
@@ -242,27 +259,44 @@ static void ext4_put_nojournal(handle_t *handle)
  * journal_end calls result in the superblock being marked dirty, so
  * that sync() will call the filesystem's write_super callback if
  * appropriate.
+ *
+ * To avoid j_barrier hold in userspace when a user calls freeze(),
+ * ext4 prevents a new handle from being started by s_frozen, which
+ * is in an upper layer.
  */
 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 {
 	journal_t *journal;
+	handle_t  *handle;
 
 	if (sb->s_flags & MS_RDONLY)
 		return ERR_PTR(-EROFS);
 
-	vfs_check_frozen(sb, SB_FREEZE_TRANS);
-	/* Special case here: if the journal has aborted behind our
-	 * backs (eg. EIO in the commit thread), then we still need to
-	 * take the FS itself readonly cleanly. */
 	journal = EXT4_SB(sb)->s_journal;
-	if (journal) {
-		if (is_journal_aborted(journal)) {
-			ext4_abort(sb, "Detected aborted journal");
-			return ERR_PTR(-EROFS);
-		}
-		return jbd2_journal_start(journal, nblocks);
+	handle = ext4_journal_current_handle();
+
+	/*
+	 * If a handle has been started, it should be allowed to
+	 * finish, otherwise deadlock could happen between freeze
+	 * and others(e.g. truncate) due to the restart of the
+	 * journal handle if the filesystem is forzen and active
+	 * handles are not stopped.
+	 */
+	if (!handle)
+		vfs_check_frozen(sb, SB_FREEZE_TRANS);
+
+	if (!journal)
+		return ext4_get_nojournal();
+	/*
+	 * Special case here: if the journal has aborted behind our
+	 * backs (eg. EIO in the commit thread), then we still need to
+	 * take the FS itself readonly cleanly.
+	 */
+	if (is_journal_aborted(journal)) {
+		ext4_abort(sb, "Detected aborted journal");
+		return ERR_PTR(-EROFS);
 	}
-	return ext4_get_nojournal();
+	return jbd2_journal_start(journal, nblocks);
 }
 
 /*
@@ -617,7 +651,7 @@ __acquires(bitlock)
 	 * filesystem will have already been marked read/only and the
 	 * journal has been aborted.  We return 1 as a hint to callers
 	 * who might what to use the return value from
-	 * ext4_grp_locked_error() to distinguish beween the
+	 * ext4_grp_locked_error() to distinguish between the
 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 	 * aggressively from the ext4 function in question, with a
 	 * more appropriate error code.
@@ -789,6 +823,8 @@ static void ext4_put_super(struct super_block *sb)
 		invalidate_bdev(sbi->journal_bdev);
 		ext4_blkdev_remove(sbi);
 	}
+	if (sbi->s_mmp_tsk)
+		kthread_stop(sbi->s_mmp_tsk);
 	sb->s_fs_info = NULL;
 	/*
 	 * Now that we are completely done shutting down the
@@ -1079,7 +1115,7 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 
 	if (!test_opt(sb, INIT_INODE_TABLE))
 		seq_puts(seq, ",noinit_inode_table");
-	else if (sbi->s_li_wait_mult)
+	else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
 		seq_printf(seq, ",init_inode_table=%u",
 			   (unsigned) sbi->s_li_wait_mult);
 
@@ -1170,9 +1206,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
 				const char *data, size_t len, loff_t off);
 
 static const struct dquot_operations ext4_quota_operations = {
-#ifdef CONFIG_QUOTA
 	.get_reserved_space = ext4_get_reserved_space,
-#endif
 	.write_dquot	= ext4_write_dquot,
 	.acquire_dquot	= ext4_acquire_dquot,
 	.release_dquot	= ext4_release_dquot,
@@ -1883,7 +1917,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 		ext4_msg(sb, KERN_WARNING,
 			 "warning: mounting fs with errors, "
 			 "running e2fsck is recommended");
-	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
+	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
 		 le16_to_cpu(es->s_mnt_count) >=
 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 		ext4_msg(sb, KERN_WARNING,
@@ -1915,6 +1949,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 			EXT4_INODES_PER_GROUP(sb),
 			sbi->s_mount_opt, sbi->s_mount_opt2);
 
+	cleancache_init_fs(sb);
 	return res;
 }
 
@@ -2408,6 +2443,18 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
 }
 
+static ssize_t extent_cache_hits_show(struct ext4_attr *a,
+				      struct ext4_sb_info *sbi, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
+}
+
+static ssize_t extent_cache_misses_show(struct ext4_attr *a,
+					struct ext4_sb_info *sbi, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
+}
+
 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
 					  struct ext4_sb_info *sbi,
 					  const char *buf, size_t count)
@@ -2465,6 +2512,8 @@ static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
 EXT4_RO_ATTR(delayed_allocation_blocks);
 EXT4_RO_ATTR(session_write_kbytes);
 EXT4_RO_ATTR(lifetime_write_kbytes);
+EXT4_RO_ATTR(extent_cache_hits);
+EXT4_RO_ATTR(extent_cache_misses);
 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
 		 inode_readahead_blks_store, s_inode_readahead_blks);
 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
@@ -2480,6 +2529,8 @@ static struct attribute *ext4_attrs[] = {
 	ATTR_LIST(delayed_allocation_blocks),
 	ATTR_LIST(session_write_kbytes),
 	ATTR_LIST(lifetime_write_kbytes),
+	ATTR_LIST(extent_cache_hits),
+	ATTR_LIST(extent_cache_misses),
 	ATTR_LIST(inode_readahead_blks),
 	ATTR_LIST(inode_goal),
 	ATTR_LIST(mb_stats),
@@ -2642,12 +2693,6 @@ static void print_daily_error_info(unsigned long arg)
 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
 }
 
-static void ext4_lazyinode_timeout(unsigned long data)
-{
-	struct task_struct *p = (struct task_struct *)data;
-	wake_up_process(p);
-}
-
 /* Find next suitable group and run ext4_init_inode_table */
 static int ext4_run_li_request(struct ext4_li_request *elr)
 {
@@ -2679,11 +2724,8 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
 		ret = ext4_init_inode_table(sb, group,
 					    elr->lr_timeout ? 0 : 1);
 		if (elr->lr_timeout == 0) {
-			timeout = jiffies - timeout;
-			if (elr->lr_sbi->s_li_wait_mult)
-				timeout *= elr->lr_sbi->s_li_wait_mult;
-			else
-				timeout *= 20;
+			timeout = (jiffies - timeout) *
+				  elr->lr_sbi->s_li_wait_mult;
 			elr->lr_timeout = timeout;
 		}
 		elr->lr_next_sched = jiffies + elr->lr_timeout;
@@ -2695,7 +2737,7 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
 
 /*
  * Remove lr_request from the list_request and free the
- * request tructure. Should be called with li_list_mtx held
+ * request structure. Should be called with li_list_mtx held
  */
 static void ext4_remove_li_request(struct ext4_li_request *elr)
 {
@@ -2713,14 +2755,16 @@ static void ext4_remove_li_request(struct ext4_li_request *elr)
 
 static void ext4_unregister_li_request(struct super_block *sb)
 {
-	struct ext4_li_request *elr = EXT4_SB(sb)->s_li_request;
-
-	if (!ext4_li_info)
+	mutex_lock(&ext4_li_mtx);
+	if (!ext4_li_info) {
+		mutex_unlock(&ext4_li_mtx);
 		return;
+	}
 
 	mutex_lock(&ext4_li_info->li_list_mtx);
-	ext4_remove_li_request(elr);
+	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
 	mutex_unlock(&ext4_li_info->li_list_mtx);
+	mutex_unlock(&ext4_li_mtx);
 }
 
 static struct task_struct *ext4_lazyinit_task;
@@ -2739,17 +2783,10 @@ static int ext4_lazyinit_thread(void *arg)
 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
 	struct list_head *pos, *n;
 	struct ext4_li_request *elr;
-	unsigned long next_wakeup;
-	DEFINE_WAIT(wait);
+	unsigned long next_wakeup, cur;
 
 	BUG_ON(NULL == eli);
 
-	eli->li_timer.data = (unsigned long)current;
-	eli->li_timer.function = ext4_lazyinode_timeout;
-
-	eli->li_task = current;
-	wake_up(&eli->li_wait_task);
-
 cont_thread:
 	while (true) {
 		next_wakeup = MAX_JIFFY_OFFSET;
@@ -2780,19 +2817,15 @@ cont_thread:
 		if (freezing(current))
 			refrigerator();
 
-		if ((time_after_eq(jiffies, next_wakeup)) ||
+		cur = jiffies;
+		if ((time_after_eq(cur, next_wakeup)) ||
 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
 			cond_resched();
 			continue;
 		}
 
-		eli->li_timer.expires = next_wakeup;
-		add_timer(&eli->li_timer);
-		prepare_to_wait(&eli->li_wait_daemon, &wait,
-				TASK_INTERRUPTIBLE);
-		if (time_before(jiffies, next_wakeup))
-			schedule();
-		finish_wait(&eli->li_wait_daemon, &wait);
+		schedule_timeout_interruptible(next_wakeup - cur);
+
 		if (kthread_should_stop()) {
 			ext4_clear_request_list();
 			goto exit_thread;
@@ -2816,12 +2849,7 @@ exit_thread:
 		goto cont_thread;
 	}
 	mutex_unlock(&eli->li_list_mtx);
-	del_timer_sync(&ext4_li_info->li_timer);
-	eli->li_task = NULL;
-	wake_up(&eli->li_wait_task);
-
 	kfree(ext4_li_info);
-	ext4_lazyinit_task = NULL;
 	ext4_li_info = NULL;
 	mutex_unlock(&ext4_li_mtx);
 
@@ -2849,7 +2877,6 @@ static int ext4_run_lazyinit_thread(void)
 	if (IS_ERR(ext4_lazyinit_task)) {
 		int err = PTR_ERR(ext4_lazyinit_task);
 		ext4_clear_request_list();
-		del_timer_sync(&ext4_li_info->li_timer);
 		kfree(ext4_li_info);
 		ext4_li_info = NULL;
 		printk(KERN_CRIT "EXT4: error %d creating inode table "
@@ -2858,8 +2885,6 @@ static int ext4_run_lazyinit_thread(void)
 		return err;
 	}
 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
-
-	wait_event(ext4_li_info->li_wait_task, ext4_li_info->li_task != NULL);
 	return 0;
 }
 
@@ -2894,13 +2919,9 @@ static int ext4_li_info_new(void)
 	if (!eli)
 		return -ENOMEM;
 
-	eli->li_task = NULL;
 	INIT_LIST_HEAD(&eli->li_request_list);
 	mutex_init(&eli->li_list_mtx);
 
-	init_waitqueue_head(&eli->li_wait_daemon);
-	init_waitqueue_head(&eli->li_wait_task);
-	init_timer(&eli->li_timer);
 	eli->li_state |= EXT4_LAZYINIT_QUIT;
 
 	ext4_li_info = eli;
@@ -2943,20 +2964,19 @@ static int ext4_register_li_request(struct super_block *sb,
 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 	int ret = 0;
 
-	if (sbi->s_li_request != NULL)
+	if (sbi->s_li_request != NULL) {
+		/*
+		 * Reset timeout so it can be computed again, because
+		 * s_li_wait_mult might have changed.
+		 */
+		sbi->s_li_request->lr_timeout = 0;
 		return 0;
+	}
 
 	if (first_not_zeroed == ngroups ||
 	    (sb->s_flags & MS_RDONLY) ||
-	    !test_opt(sb, INIT_INODE_TABLE)) {
-		sbi->s_li_request = NULL;
-		return 0;
-	}
-
-	if (first_not_zeroed == ngroups) {
-		sbi->s_li_request = NULL;
+	    !test_opt(sb, INIT_INODE_TABLE))
 		return 0;
-	}
 
 	elr = ext4_li_request_new(sb, first_not_zeroed);
 	if (!elr)
@@ -2975,6 +2995,12 @@ static int ext4_register_li_request(struct super_block *sb,
 	mutex_unlock(&ext4_li_info->li_list_mtx);
 
 	sbi->s_li_request = elr;
+	/*
+	 * set elr to NULL here since it has been inserted to
+	 * the request_list and the removal and free of it is
+	 * handled by ext4_clear_request_list from now on.
+	 */
+	elr = NULL;
 
 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
 		ret = ext4_run_lazyinit_thread();
@@ -3143,6 +3169,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
 		set_opt(sb, DELALLOC);
 
+	/*
+	 * set default s_li_wait_mult for lazyinit, for the case there is
+	 * no mount option specified.
+	 */
+	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
+
 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
 			   &journal_devnum, &journal_ioprio, NULL, 0)) {
 		ext4_msg(sb, KERN_WARNING,
@@ -3164,6 +3196,28 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		       "feature flags set on rev 0 fs, "
 		       "running e2fsck is recommended");
 
+	if (IS_EXT2_SB(sb)) {
+		if (ext2_feature_set_ok(sb))
+			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
+				 "using the ext4 subsystem");
+		else {
+			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
+				 "to feature incompatibilities");
+			goto failed_mount;
+		}
+	}
+
+	if (IS_EXT3_SB(sb)) {
+		if (ext3_feature_set_ok(sb))
+			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
+				 "using the ext4 subsystem");
+		else {
+			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
+				 "to feature incompatibilities");
+			goto failed_mount;
+		}
+	}
+
 	/*
 	 * Check feature flags regardless of the revision level, since we
 	 * previously didn't change the revision level when setting the flags,
@@ -3385,6 +3439,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
 
+	init_timer(&sbi->s_err_report);
+	sbi->s_err_report.function = print_daily_error_info;
+	sbi->s_err_report.data = (unsigned long) sb;
+
 	err = percpu_counter_init(&sbi->s_freeblocks_counter,
 			ext4_count_free_blocks(sb));
 	if (!err) {
@@ -3432,6 +3490,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
 				    EXT4_FEATURE_INCOMPAT_RECOVER));
 
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
+	    !(sb->s_flags & MS_RDONLY))
+		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
+			goto failed_mount3;
+
 	/*
 	 * The first inode we look at is the journal inode.  Don't try
 	 * root first: it may be modified in the journal!
@@ -3447,7 +3510,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount_wq;
 	} else {
 		clear_opt(sb, DATA_FLAGS);
-		set_opt(sb, WRITEBACK_DATA);
 		sbi->s_journal = NULL;
 		needs_recovery = 0;
 		goto no_journal;
@@ -3646,9 +3708,6 @@ no_journal:
 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
 
-	init_timer(&sbi->s_err_report);
-	sbi->s_err_report.function = print_daily_error_info;
-	sbi->s_err_report.data = (unsigned long) sb;
 	if (es->s_error_count)
 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
 
@@ -3672,6 +3731,7 @@ failed_mount_wq:
 		sbi->s_journal = NULL;
 	}
 failed_mount3:
+	del_timer(&sbi->s_err_report);
 	if (sbi->s_flex_groups) {
 		if (is_vmalloc_addr(sbi->s_flex_groups))
 			vfree(sbi->s_flex_groups);
@@ -3682,6 +3742,8 @@ failed_mount3:
 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
 	percpu_counter_destroy(&sbi->s_dirs_counter);
 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
+	if (sbi->s_mmp_tsk)
+		kthread_stop(sbi->s_mmp_tsk);
 failed_mount2:
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
@@ -4138,6 +4200,11 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
 /*
  * LVM calls this function before a (read-only) snapshot is created.  This
  * gives us a chance to flush the journal completely and mark the fs clean.
+ *
+ * Note that only this function cannot bring a filesystem to be in a clean
+ * state independently, because ext4 prevents a new handle from being started
+ * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
+ * the upper layer.
  */
 static int ext4_freeze(struct super_block *sb)
 {
@@ -4212,7 +4279,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	int enable_quota = 0;
 	ext4_group_t g;
 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
-	int err;
+	int err = 0;
 #ifdef CONFIG_QUOTA
 	int i;
 #endif
@@ -4338,6 +4405,13 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 				goto restore_opts;
 			if (!ext4_setup_super(sb, es, 0))
 				sb->s_flags &= ~MS_RDONLY;
+			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+						     EXT4_FEATURE_INCOMPAT_MMP))
+				if (ext4_multi_mount_protect(sb,
+						le64_to_cpu(es->s_mmp_block))) {
+					err = -EROFS;
+					goto restore_opts;
+				}
 			enable_quota = 1;
 		}
 	}
@@ -4402,6 +4476,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_super_block *es = sbi->s_es;
 	u64 fsid;
+	s64 bfree;
 
 	if (test_opt(sb, MINIX_DF)) {
 		sbi->s_overhead_last = 0;
@@ -4445,8 +4520,10 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_type = EXT4_SUPER_MAGIC;
 	buf->f_bsize = sb->s_blocksize;
 	buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
-	buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
+	bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
 		       percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
+	/* prevent underflow in case that few free space is available */
+	buf->f_bfree = max_t(s64, bfree, 0);
 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
 	if (buf->f_bfree < ext4_r_blocks_count(es))
 		buf->f_bavail = 0;
@@ -4614,17 +4691,33 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 
 static int ext4_quota_off(struct super_block *sb, int type)
 {
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	handle_t *handle;
+
 	/* Force all delayed allocation blocks to be allocated.
 	 * Caller already holds s_umount sem */
 	if (test_opt(sb, DELALLOC))
 		sync_filesystem(sb);
 
+	if (!inode)
+		goto out;
+
+	/* Update modification times of quota files when userspace can
+	 * start looking at them */
+	handle = ext4_journal_start(inode, 1);
+	if (IS_ERR(handle))
+		goto out;
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	ext4_mark_inode_dirty(handle, inode);
+	ext4_journal_stop(handle);
+
+out:
 	return dquot_quota_off(sb, type);
 }
 
 /* Read data from quotafile - avoid pagecache and such because we cannot afford
  * acquiring the locks... As quota files are never truncated and quota code
- * itself serializes the operations (and noone else should touch the files)
+ * itself serializes the operations (and no one else should touch the files)
  * we don't have to be afraid of races */
 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off)
@@ -4714,9 +4807,8 @@ out:
 	if (inode->i_size < off + len) {
 		i_size_write(inode, off + len);
 		EXT4_I(inode)->i_disksize = inode->i_size;
+		ext4_mark_inode_dirty(handle, inode);
 	}
-	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-	ext4_mark_inode_dirty(handle, inode);
 	mutex_unlock(&inode->i_mutex);
 	return len;
 }
@@ -4730,14 +4822,6 @@ static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
 }
 
 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
-static struct file_system_type ext2_fs_type = {
-	.owner		= THIS_MODULE,
-	.name		= "ext2",
-	.mount		= ext4_mount,
-	.kill_sb	= kill_block_super,
-	.fs_flags	= FS_REQUIRES_DEV,
-};
-
 static inline void register_as_ext2(void)
 {
 	int err = register_filesystem(&ext2_fs_type);
@@ -4750,10 +4834,22 @@ static inline void unregister_as_ext2(void)
 {
 	unregister_filesystem(&ext2_fs_type);
 }
+
+static inline int ext2_feature_set_ok(struct super_block *sb)
+{
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
+		return 0;
+	if (sb->s_flags & MS_RDONLY)
+		return 1;
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
+		return 0;
+	return 1;
+}
 MODULE_ALIAS("ext2");
 #else
 static inline void register_as_ext2(void) { }
 static inline void unregister_as_ext2(void) { }
+static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
 #endif
 
 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
@@ -4769,10 +4865,24 @@ static inline void unregister_as_ext3(void)
 {
 	unregister_filesystem(&ext3_fs_type);
 }
+
+static inline int ext3_feature_set_ok(struct super_block *sb)
+{
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
+		return 0;
+	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
+		return 0;
+	if (sb->s_flags & MS_RDONLY)
+		return 1;
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
+		return 0;
+	return 1;
+}
 MODULE_ALIAS("ext3");
 #else
 static inline void register_as_ext3(void) { }
 static inline void unregister_as_ext3(void) { }
+static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
 #endif
 
 static struct file_system_type ext4_fs_type = {
@@ -4856,8 +4966,8 @@ static int __init ext4_init_fs(void)
 	err = init_inodecache();
 	if (err)
 		goto out1;
-	register_as_ext2();
 	register_as_ext3();
+	register_as_ext2();
 	err = register_filesystem(&ext4_fs_type);
 	if (err)
 		goto out;