Re: [f2fs-dev] [PATCH] f2fs: make gc_idle sysfs node readable

[Yangtao Li]

Hi Chao,

What:       /sys/fs/f2fs/<disk>/gc_idle
Date:       July 2013
Contact:    "Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
Description:    Controls the victim selection policy for garbage collection.
        Setting gc_idle = 0(default) will disable this option. Setting:

        ===========  ===============================================
        gc_idle = 1  will select the Cost Benefit approach & setting
        gc_idle = 2  will select the greedy approach & setting
        gc_idle = 3  will select the age-threshold based approach.
        ===========  ===============================================

>From the kernel documentation, this node only describes the writing of
the value, and does not describe the reading of the value.

Actually, this modification does the same thing as commit e60aeb2dee1a
("f2fs: make gc_urgent and gc_segment_mode sysfs node readabl").
I understand it is an addition to the omission of the patch above.

Why gc_urgent and gc_segment_mode can be modified to string, but gc_idle
breaks forward compatibility?

Thanks,