Re: [PATCH 3/5] f2fs: move f2fs_balance_fs to correct place in unlink

[Namjae Jeon]

2013/3/8, Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>:
> 2013-03-04 (ì), 15:10 +0900, Namjae Jeon:
>> 2013/3/3, Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>:
>> > 2013-03-02 (í), 12:41 +0900, Namjae Jeon:
>> >> From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
>> >>
>> >> Actual dirty of pages will occur in f2fs_delete_entry so move the
>> >> f2fs_balance_fs just before deletion.
>> >>
>> >> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
>> >> Signed-off-by: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
>> >> ---
>> >>  fs/f2fs/namei.c |    4 ++--
>> >>  1 file changed, 2 insertions(+), 2 deletions(-)
>> >>
>> >> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
>> >> index 1a49b88..eaa86f5 100644
>> >> --- a/fs/f2fs/namei.c
>> >> +++ b/fs/f2fs/namei.c
>> >> @@ -223,8 +223,6 @@ static int f2fs_unlink(struct inode *dir, struct
>> >> dentry *dentry)
>> >>  	struct page *page;
>> >>  	int err = -ENOENT;
>> >>
>> >> -	f2fs_balance_fs(sbi);
>> >> -
>> >>  	de = f2fs_find_entry(dir, &dentry->d_name, &page);
>> >>  	if (!de)
>> >>  		goto fail;
>> >> @@ -236,6 +234,8 @@ static int f2fs_unlink(struct inode *dir, struct
>> >> dentry *dentry)
>> >>  		goto fail;
>> >>  	}
>> >>
>> >> +	f2fs_balance_fs(sbi);
>> >> +
>> >
>> > I think we don't need to do this because of no issues on performance
>> > and
>> > reliability.
>> > In addition, it would be better to call f2fs_balance_fs without any
>> > dentry page.
>> Regarding moving âf2fs_balance_fsâ in unlink partâ we considered one
>> scenario.
>> Suppose â when the disk is full and it really needed to trigger the
>> Garbage collection. But in this we considered one scenario. Letâs say
>> the ânameâ being passed is for invalid file i.e., the file does not
>> exist. So, primarily in this case â I think it should return
>> immediately.
>> In such cases it actually results in wrong timing results for the
>> non-existence files.
>> For this observation we thought that f2fs_balance_fs be instead called
>> at a proper place i.e., after there is no lookup-failure.
>
> If so, could you check all the locations of f2fs_balance_fs and write
> one patch for whole things?
> I suspect that many directory operations are exposed to this issue.
> Thanks,
Sure, I will check all places to use f2fs_balance_fs. And will post
updated patch again.
Thanks Jaegeuk!
>
>>
>> Let me know your opinion.
>> Thanks.
>> >
>> >>  	f2fs_delete_entry(de, page, inode);
>> >>
>> >>  	/* In order to evict this inode,  we set it dirty */
>> >
>> > --
>> > Jaegeuk Kim
>> > Samsung
>> >
>> --
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>
> --
> Jaegeuk Kim
> Samsung
>
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