Re: [RFC v14-rc3][PATCH 11/36] add generic checkpoint f_op to ext fses

[Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>]

Serge E. Hallyn wrote:
> Quoting Serge E. Hallyn (serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org):
>> Quoting Oren Laadan (orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org):
>>> From: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>>>
>>> This marks ext[234] as being checkpointable.  There will be many
>>> more to do this to, but this is a start.
>>>
>>> Signed-off-by: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>>> ---
>>>  fs/ext2/dir.c  |    1 +
>>>  fs/ext2/file.c |    2 ++
>>>  fs/ext3/dir.c  |    1 +
>>>  fs/ext3/file.c |    1 +
>>>  fs/ext4/dir.c  |    1 +
>>>  fs/ext4/file.c |    1 +
>>>  6 files changed, 7 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
>>> index 2999d72..4f1dd79 100644
>>> --- a/fs/ext2/dir.c
>>> +++ b/fs/ext2/dir.c
>>> @@ -721,4 +721,5 @@ const struct file_operations ext2_dir_operations = {
>>>  	.compat_ioctl	= ext2_compat_ioctl,
>>>  #endif
>>>  	.fsync		= ext2_sync_file,
>>> +	.checkpoint	= generic_file_checkpoint,
>> The checkpoint() method is only defined in struct file_operations if
>> CONFIG_CHECKPOINT=y.  So this can't possibly compile when
>> CONFIG_CHECKPOINT=n...
> 
> BTW i think the better way to handle it is not to put everything under
> ifdefs, but rather always let file_operations have the ->checkpoint()
> fn, and just make generic_file_checkpoint() a dummy function when
> CONFIG_CHECKPOINT=n.

Yes, that's already taken care of (further up in fs.h) in previous
patch. It was silly to wrap #ifdef's around the 'checkpoint' field
of 'struct file_operations'

Thanks,

Oren.