Re: [PATCH 2/6] f2fs: support goingdown for fs shutdown

[Eric Sandeen <sandeen@sandeen.net>]

On 1/8/15 2:18 PM, Jaegeuk Kim wrote:
> On Thu, Jan 08, 2015 at 01:54:20PM -0600, Eric Sandeen wrote:
>> On 1/8/15 12:10 PM, Jaegeuk Kim wrote:
>>> This patch add an ioctl to shutdown f2fs, which stops all the further block
>>> writes after this point.
>>
>> would it make sense to just re-use the xfs ioctl nr, if the semantics are
>> the same?
> 
> The semantics are not same for now.
> In order to reuse xfs ioctl, it needs to support options for flushing logs.

the xfs iotl has 3 behaviors optional:

#define XFS_FSOP_GOING_FLAGS_DEFAULT            0x0     /* going down */
#define XFS_FSOP_GOING_FLAGS_LOGFLUSH           0x1     /* flush log but not data */
#define XFS_FSOP_GOING_FLAGS_NOLOGFLUSH         0x2     /* don't flush log nor data */

if f2fs currently supports a subset, you could just -EOPNOTSUPP on the others.

If the semantics are completely different, maybe it shouldn't share the
name at all.  ;)

Just a thought...

-Eric

> Thanks,
> 
>>
>> That way any test using it will "just work" on f2fs...
>>
>> -Eric