Re: [PATCH v3 2/5] fat: allocate persistent inode numbers

From: Namjae Jeon
Date: Tue Sep 25 2012 - 01:33:15 EST


Hi OGAWA.

It works fine. there is no estale error while memory reclaim.
I will make patchset again as review comment and your suggestion
(encode_fh, fat_getattr).

Thanks!

2012/9/25, J. Bruce Fields <bfields@xxxxxxxxxxxx>:
> On Tue, Sep 25, 2012 at 01:16:45AM +0900, OGAWA Hirofumi wrote:
>> "J. Bruce Fields" <bfields@xxxxxxxxxxxx> writes:
>>
>> >> > There is some unclear thing.
>> >> > When I see first mail, I think maybe you don't want to use i_pos for
>> >> > inode->ino.
>> >> > FAT allocate inode->ino from i_unique on server side and If NFS
>> >> > client
>> >> > use i_pos for inode->ino in fat_get_attr, inode numbers on each
>> >> > client/server will still be mismatched.
>> >> >
>> >> > Would you plz give me hint ?
>> >>
>> >> ->i_ino is long. It can't hold i_pos fully on 32bit arch, so we can't
>> >> use ->i_no to store i_pos, and changing ->i_ino is unnecessary. If
>> >> getattr() returned i_pos as ino, nobody see ->i_ino anymore except
>> >> internal of kernel.
>> >
>> > The NFS server must always return the same inode number for the same
>> > filehandle. To do otherwise is a bug.
>> >
>> >> Furthermore I think there is no issue even if server and client didn't
>> >> have same ino. Because client just uses FH (nfs4 seems to be using
>> >> stat.ino though).
>> >
>> > The client may expose a different inode number to userspace, but it's
>> > probably the server-provided inode number that it's checking.
>> >
>> > (And even if the Linux client didn't currently happen to do that check,
>> > this would still be a bug.)
>>
>> In this context, inode number != inode->i_ino, right? It should be
>> kstat.ino, and in FAT case, it will return i_pos always. Otherwise 64bit
>> inode number would not work.
>>
>> So, I think we are doing right thing for now.
>
> Oh, OK. On a quick check, yes, the numbers the server returns to
> clients are taken from either kstat.ino or the ino argument of the
> filldir function.
>
> --b.
>
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