Re: [PATCH] Revert "f2fs: remove unreachable lazytime mount option parsing"

[Eric Sandeen <sandeen@redhat.com>]

On 11/12/24 3:39 PM, Jaegeuk Kim wrote:
> Hi Eric,
> 
> Could you please check this revert as it breaks the mount()?
> It seems F2FS needs to implement new mount support.
> 
> Thanks,

I'm sorry, I missed this email. I will look into it more today.

As for f2fs new mount API support, I have been struggling with it for a
long time, f2fs has been uniquely complex. The assumption that the superblock
and on-disk features are known at option parsing time makes it much more
difficult than most other filesystems.

But if there's a problem/regression with this commit, I have no objection to
reverting the commit for now, and I'm sorry for the error.

-Eric

> On 11/12, Jaegeuk Kim wrote:
>> This reverts commit 54f43a10fa257ad4af02a1d157fefef6ebcfa7dc.
>>
>> The above commit broke the lazytime mount, given
>>
>> mount("/dev/vdb", "/mnt/test", "f2fs", 0, "lazytime");
>>
>> CC: stable@vger.kernel.org # 6.11+
>> Signed-off-by: Daniel Rosenberg <drosen@google.com>
>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>> ---
>>  fs/f2fs/super.c | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 49519439b770..35c4394e4fc6 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -150,6 +150,8 @@ enum {
>>  	Opt_mode,
>>  	Opt_fault_injection,
>>  	Opt_fault_type,
>> +	Opt_lazytime,
>> +	Opt_nolazytime,
>>  	Opt_quota,
>>  	Opt_noquota,
>>  	Opt_usrquota,
>> @@ -226,6 +228,8 @@ static match_table_t f2fs_tokens = {
>>  	{Opt_mode, "mode=%s"},
>>  	{Opt_fault_injection, "fault_injection=%u"},
>>  	{Opt_fault_type, "fault_type=%u"},
>> +	{Opt_lazytime, "lazytime"},
>> +	{Opt_nolazytime, "nolazytime"},
>>  	{Opt_quota, "quota"},
>>  	{Opt_noquota, "noquota"},
>>  	{Opt_usrquota, "usrquota"},
>> @@ -922,6 +926,12 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>  			f2fs_info(sbi, "fault_type options not supported");
>>  			break;
>>  #endif
>> +		case Opt_lazytime:
>> +			sb->s_flags |= SB_LAZYTIME;
>> +			break;
>> +		case Opt_nolazytime:
>> +			sb->s_flags &= ~SB_LAZYTIME;
>> +			break;
>>  #ifdef CONFIG_QUOTA
>>  		case Opt_quota:
>>  		case Opt_usrquota:
>> -- 
>> 2.47.0.277.g8800431eea-goog
>