Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9ca92389 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: Use separate super_operations structure for no_journal filesystems 



By using a separate super_operations structure for filesystems that
have and don't have journals, we can simply ext4_write_super() ---
which is only needed when no journal is present --- and ext4_freeze(),
ext4_unfreeze(), and ext4_sync_fs(), which are only needed when the
journal is present.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 7234ab2a

fs/ext4/super.c

+57 −51
Original line number Diff line number Diff line
@@ -995,7 +995,6 @@ static const struct super_operations ext4_sops = { 
	.dirty_inode	= ext4_dirty_inode,

	.delete_inode	= ext4_delete_inode,

	.put_super	= ext4_put_super,

	.write_super	= ext4_write_super,

	.sync_fs	= ext4_sync_fs,

	.freeze_fs	= ext4_freeze,

	.unfreeze_fs	= ext4_unfreeze,
@@ -1010,6 +1009,25 @@ static const struct super_operations ext4_sops = { 
	.bdev_try_to_free_page = bdev_try_to_free_page,

};



static const struct super_operations ext4_nojournal_sops = {

	.alloc_inode	= ext4_alloc_inode,

	.destroy_inode	= ext4_destroy_inode,

	.write_inode	= ext4_write_inode,

	.dirty_inode	= ext4_dirty_inode,

	.delete_inode	= ext4_delete_inode,

	.write_super	= ext4_write_super,

	.put_super	= ext4_put_super,

	.statfs		= ext4_statfs,

	.remount_fs	= ext4_remount,

	.clear_inode	= ext4_clear_inode,

	.show_options	= ext4_show_options,

#ifdef CONFIG_QUOTA

	.quota_read	= ext4_quota_read,

	.quota_write	= ext4_quota_write,

#endif

	.bdev_try_to_free_page = bdev_try_to_free_page,

};



static const struct export_operations ext4_export_ops = {

	.fh_to_dentry = ext4_fh_to_dentry,

	.fh_to_parent = ext4_fh_to_parent,
@@ -2615,7 +2633,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) 
	/*

	 * set up enough so that it can read an inode

	 */

	if (!test_opt(sb, NOLOAD) &&

	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))

		sb->s_op = &ext4_sops;

	else

		sb->s_op = &ext4_nojournal_sops;

	sb->s_export_op = &ext4_export_ops;

	sb->s_xattr = ext4_xattr_handlers;

#ifdef CONFIG_QUOTA
@@ -3275,20 +3297,10 @@ int ext4_force_commit(struct super_block *sb) 
	return ret;

}



/*

 * Ext4 always journals updates to the superblock itself, so we don't

 * have to propagate any other updates to the superblock on disk at this

 * point if the journalling is enabled.

 */

static void ext4_write_super(struct super_block *sb)

{

	if (EXT4_SB(sb)->s_journal) {

		if (mutex_trylock(&sb->s_lock) != 0)

			BUG();

	} else {

	ext4_commit_super(sb, 1);

}

}



static int ext4_sync_fs(struct super_block *sb, int wait)

{
@@ -3296,15 +3308,9 @@ static int ext4_sync_fs(struct super_block *sb, int wait) 
	tid_t target;



	trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);

	if (EXT4_SB(sb)->s_journal) {

		if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal,

					      &target)) {

	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {

		if (wait)

				jbd2_log_wait_commit(EXT4_SB(sb)->s_journal,

						     target);

		}

	} else {

		ext4_commit_super(sb, wait);

			jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);

	}

	return ret;

}
@@ -3318,20 +3324,23 @@ static int ext4_freeze(struct super_block *sb) 
	int error = 0;

	journal_t *journal;



	if (!(sb->s_flags & MS_RDONLY)) {

	if (sb->s_flags & MS_RDONLY)

		return 0;



	journal = EXT4_SB(sb)->s_journal;



		if (journal) {

	/* Now we set up the journal barrier. */

	jbd2_journal_lock_updates(journal);



	/*

			 * We don't want to clear needs_recovery flag when we

			 * failed to flush the journal.

	 * Don't clear the needs_recovery flag if we failed to flush

	 * the journal.

	 */

	error = jbd2_journal_flush(journal);

			if (error < 0)

				goto out;

	if (error < 0) {

	out:

		jbd2_journal_unlock_updates(journal);

		return error;

	}



	/* Journal blocked and flushed, clear needs_recovery flag. */
@@ -3339,11 +3348,7 @@ static int ext4_freeze(struct super_block *sb) 
	error = ext4_commit_super(sb, 1);

	if (error)

		goto out;

	}

	return 0;

out:

	jbd2_journal_unlock_updates(journal);

	return error;

}



/*
@@ -3352,14 +3357,15 @@ static int ext4_freeze(struct super_block *sb) 
 */

static int ext4_unfreeze(struct super_block *sb)

{

	if (EXT4_SB(sb)->s_journal && !(sb->s_flags & MS_RDONLY)) {

	if (sb->s_flags & MS_RDONLY)

		return 0;



	lock_super(sb);

		/* Reser the needs_recovery flag before the fs is unlocked. */

	/* Reset the needs_recovery flag before the fs is unlocked. */

	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);

	ext4_commit_super(sb, 1);

	unlock_super(sb);

	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);

	}

	return 0;

}