Commit 0f5bde1d authored by Jan Kara's avatar Jan Kara Committed by Theodore Ts'o
Browse files

ext4: correctly restore system zone info when remount fails 



When remounting filesystem fails late during remount handling and
block_validity mount option is also changed during the remount, we fail
to restore system zone information to a state matching the mount option.
This is mostly harmless, just the block validity checking will not match
the situation described by the mount option. Make sure these two are always
consistent.

Reported-by: default avatarLukas Czerner <lczerner@redhat.com>
Reviewed-by: default avatarLukas Czerner <lczerner@redhat.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200728130437.7804-7-jack@suse.cz


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent e7bfb5c9

fs/ext4/block_validity.c

+0 −8
Original line number Diff line number Diff line
@@ -220,14 +220,6 @@ int ext4_setup_system_zone(struct super_block *sb) 
	int flex_size = ext4_flex_bg_size(sbi);

	int ret;



	if (!test_opt(sb, BLOCK_VALIDITY)) {

		if (sbi->system_blks)

			ext4_release_system_zone(sb);

		return 0;

	}

	if (sbi->system_blks)

		return 0;



	system_blks = kzalloc(sizeof(*system_blks), GFP_KERNEL);

	if (!system_blks)

		return -ENOMEM;

fs/ext4/super.c

+21 −8
Original line number Diff line number Diff line
@@ -4727,12 +4727,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) 


	ext4_set_resv_clusters(sb);



	if (test_opt(sb, BLOCK_VALIDITY)) {

		err = ext4_setup_system_zone(sb);

		if (err) {

			ext4_msg(sb, KERN_ERR, "failed to initialize system "

				 "zone (%d)", err);

			goto failed_mount4a;

		}

	}



	ext4_ext_init(sb);

	err = ext4_mb_init(sb);
@@ -5747,9 +5749,16 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) 
		ext4_register_li_request(sb, first_not_zeroed);

	}



	/*

	 * Handle creation of system zone data early because it can fail.

	 * Releasing of existing data is done when we are sure remount will

	 * succeed.

	 */

	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->system_blks) {

		err = ext4_setup_system_zone(sb);

		if (err)

			goto restore_opts;

	}



	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {

		err = ext4_commit_super(sb, 1);
@@ -5771,6 +5780,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) 
		}

	}

#endif

	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->system_blks)

		ext4_release_system_zone(sb);



	/*

	 * Some options can be enabled by ext4 and/or by VFS mount flag
@@ -5792,6 +5803,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) 
	sbi->s_commit_interval = old_opts.s_commit_interval;

	sbi->s_min_batch_time = old_opts.s_min_batch_time;

	sbi->s_max_batch_time = old_opts.s_max_batch_time;

	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->system_blks)

		ext4_release_system_zone(sb);

#ifdef CONFIG_QUOTA

	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;

	for (i = 0; i < EXT4_MAXQUOTAS; i++) {