Commit 8cd29088 authored by Boris Burkov's avatar Boris Burkov Committed by David Sterba
Browse files

btrfs: clear oneshot options on mount and remount 



Some options only apply during mount time and are cleared at the end
of mount. For now, the example is USEBACKUPROOT, but CLEAR_CACHE also
fits the bill, and this is a preparation patch for also clearing that
option.

One subtlety is that the current code only resets USEBACKUPROOT on rw
mounts, but the option is meaningfully "consumed" by a ro mount, so it
feels appropriate to clear in that case as well. A subsequent read-write
remount would not go through open_ctree, which is the only place that
checks the option, so the change should be benign.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarBoris Burkov <boris@bur.io>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5011139a

fs/btrfs/disk-io.c

+13 −1
Original line number Diff line number Diff line
@@ -2870,6 +2870,16 @@ static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info) 
	return 0;

}



/*

 * Some options only have meaning at mount time and shouldn't persist across

 * remounts, or be displayed. Clear these at the end of mount and remount

 * code paths.

 */

void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)

{

	btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);

}



/*

 * Mounting logic specific to read-write file systems. Shared by open_ctree

 * and btrfs_remount when remounting from read-only to read-write.
@@ -3359,7 +3369,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 
	}



	if (sb_rdonly(sb))

		return 0;

		goto clear_oneshot;



	if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&

	    btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
@@ -3402,6 +3412,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 
	}

	set_bit(BTRFS_FS_OPEN, &fs_info->flags);



clear_oneshot:

	btrfs_clear_oneshot_options(fs_info);

	return 0;



fail_qgroup:

fs/btrfs/disk-io.h

+1 −0
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ struct extent_buffer *btrfs_find_create_tree_block( 
						u64 bytenr, u64 owner_root,

						int level);

void btrfs_clean_tree_block(struct extent_buffer *buf);

void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info);

int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);

int __cold open_ctree(struct super_block *sb,

	       struct btrfs_fs_devices *fs_devices,

fs/btrfs/super.c

+1 −0
Original line number Diff line number Diff line
@@ -1999,6 +1999,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) 


	wake_up_process(fs_info->transaction_kthread);

	btrfs_remount_cleanup(fs_info, old_opts);

	btrfs_clear_oneshot_options(fs_info);

	clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);



	return 0;