* FSCache: Cookie create and destroy semantics on file open
@ 2013-08-07 4:40 Milosz Tanski
2013-08-07 6:04 ` David Howells
0 siblings, 1 reply; 4+ messages in thread
From: Milosz Tanski @ 2013-08-07 4:40 UTC (permalink / raw)
To: David Howells; +Cc: linux-cachefs, linux-fsdevel
David,
I have a question for you about how added / removing the cookie for a
NFS inode works. Right the cache entry gets added when the file is
open. It gets revoked when the file re-opened in write mode. What
happens in this case.
Open for read (create cookie) -> Open for write (destroy cookie) ->
Open for read (create cookie again)
In this case, none of the 3 files were closed.
As I understand understand when the 3rd file is open for read it will
open the old cookie, invalidate it the data... but it will still
create the cookie for that inode despite one file having being open
for write.
Is there some other kind of scheme that prevents this from happening
that I'm unaware of?
Thanks,
-Milosz
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: FSCache: Cookie create and destroy semantics on file open
2013-08-07 4:40 FSCache: Cookie create and destroy semantics on file open Milosz Tanski
@ 2013-08-07 6:04 ` David Howells
2013-08-07 12:08 ` Milosz Tanski
2013-08-07 12:46 ` David Howells
0 siblings, 2 replies; 4+ messages in thread
From: David Howells @ 2013-08-07 6:04 UTC (permalink / raw)
To: Milosz Tanski; +Cc: dhowells, linux-cachefs, linux-fsdevel
Milosz Tanski <milosz@adfin.com> wrote:
> I have a question for you about how added / removing the cookie for a
> NFS inode works. Right the cache entry gets added when the file is
> open. It gets revoked when the file re-opened in write mode. What
> happens in this case.
>
> Open for read (create cookie) -> Open for write (destroy cookie) ->
> Open for read (create cookie again)
>
> In this case, none of the 3 files were closed.
No. The way NFS is doing this is wrong. I have been given some patches that
should fix this, I think.
David
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: FSCache: Cookie create and destroy semantics on file open
2013-08-07 6:04 ` David Howells
@ 2013-08-07 12:08 ` Milosz Tanski
2013-08-07 12:46 ` David Howells
1 sibling, 0 replies; 4+ messages in thread
From: Milosz Tanski @ 2013-08-07 12:08 UTC (permalink / raw)
To: David Howells; +Cc: linux-cachefs, linux-fsdevel
Can you share those patches? I'd like to know what the approach you've
taken since I'm trying to figure out how to solve it for Ceph.
- M
On Aug 7, 2013, at 2:04 AM, David Howells <dhowells@redhat.com> wrote:
> Milosz Tanski <milosz@adfin.com> wrote:
>
>> I have a question for you about how added / removing the cookie for a
>> NFS inode works. Right the cache entry gets added when the file is
>> open. It gets revoked when the file re-opened in write mode. What
>> happens in this case.
>>
>> Open for read (create cookie) -> Open for write (destroy cookie) ->
>> Open for read (create cookie again)
>>
>> In this case, none of the 3 files were closed.
>
> No. The way NFS is doing this is wrong. I have been given some patches that
> should fix this, I think.
>
> David
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: FSCache: Cookie create and destroy semantics on file open
2013-08-07 6:04 ` David Howells
2013-08-07 12:08 ` Milosz Tanski
@ 2013-08-07 12:46 ` David Howells
1 sibling, 0 replies; 4+ messages in thread
From: David Howells @ 2013-08-07 12:46 UTC (permalink / raw)
To: Milosz Tanski; +Cc: dhowells, jiayisuse, linux-cachefs, linux-fsdevel
Milosz Tanski <milosz@adfin.com> wrote:
> Can you share those patches? I'd like to know what the approach you've
> taken since I'm trying to figure out how to solve it for Ceph.
http://www.jiayi.net/works/nfsfscache-writeback-cache/
David
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-08-07 12:46 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2013-08-07 4:40 FSCache: Cookie create and destroy semantics on file open Milosz Tanski
2013-08-07 6:04 ` David Howells
2013-08-07 12:08 ` Milosz Tanski
2013-08-07 12:46 ` David Howells
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