From: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
To: Frank van der Linden <fllinden@amazon.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna.schumaker@netapp.com>,
linux-nfs <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH 03/13] NFSv4.2: query the server for extended attribute support
Date: Fri, 13 Mar 2020 12:11:27 +0100 (CET) [thread overview]
Message-ID: <948465413.4651196.1584097887947.JavaMail.zimbra@desy.de> (raw)
In-Reply-To: <20200312211555.GA5974@dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com>
Hi Frank,
I think the way how you have implemented is almost correct. You query
server for supported attributes. As result client will get all attributes
supported bu the server and if FATTR4_XATTR_SUPPORT is returned, then client
adds xattr capability. This the way how I read rfc8276. Do you have a different
opinion?
Regards,
Tigran.
----- Original Message -----
> From: "Frank van der Linden" <fllinden@amazon.com>
> To: "Tigran Mkrtchyan" <tigran.mkrtchyan@desy.de>
> Cc: "Trond Myklebust" <trond.myklebust@hammerspace.com>, "Anna Schumaker" <anna.schumaker@netapp.com>, "linux-nfs"
> <linux-nfs@vger.kernel.org>
> Sent: Thursday, March 12, 2020 10:15:55 PM
> Subject: Re: [PATCH 03/13] NFSv4.2: query the server for extended attribute support
> On Thu, Mar 12, 2020 at 08:51:39PM +0000, Frank van der Linden wrote:
>> 1) The xattr_support attribute exists
>> 2) The xattr support attribute exists *and* it's true for the root fh
>>
>> Currently the code does 2) in one operation. That might not be 100%
>> correct - the RFC does mention that (section 8.2):
>>
>> "Before interrogating this attribute using GETATTR, a client should
>> determine whether it is a supported attribute by interrogating the
>> supported_attrs attribute."
>>
>> That's a "should", not a "MUST", but it's still waving its finger
>> at you not to do this.
>>
>> Since 8.2.1 says:
>>
>> "However, a client may reasonably assume that a server
>> (or file system) that does not support the xattr_support attribute
>> does not provide xattr support, and it acts on that basis."
>>
>> ..I think you're right, and the code should just use the existence
>> of the attribute as a signal that the server knows about xattrs -
>> operations should still error out correctly if it doesn't.
>>
>> I'll make that change, thanks.
>
> ..or, alternatively, only query xattr_support in nfs4_server_capabilities,
> and then its actual value, if it exists, in nfs4_fs_info.
>
> Any opinions on this?
>
> - Frank
next prev parent reply other threads:[~2020-03-13 11:11 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 19:56 [PATCH 00/13] client side user xattr (RFC8276) support Frank van der Linden
2020-03-11 19:56 ` [PATCH 01/13] nfs,nfsd: NFSv4.2 extended attribute protocol definitions Frank van der Linden
2020-03-11 19:56 ` [PATCH 02/13] nfs: add client side only definitions for user xattrs Frank van der Linden
2020-03-11 19:56 ` [PATCH 03/13] NFSv4.2: query the server for extended attribute support Frank van der Linden
2020-03-12 16:15 ` Mkrtchyan, Tigran
2020-03-12 20:51 ` Frank van der Linden
2020-03-12 21:15 ` Frank van der Linden
2020-03-13 11:11 ` Mkrtchyan, Tigran [this message]
2020-03-13 13:50 ` Trond Myklebust
2020-03-13 14:19 ` Mkrtchyan, Tigran
2020-03-13 17:10 ` Trond Myklebust
2020-03-13 17:55 ` Frank van der Linden
2020-03-11 19:56 ` [PATCH 04/13] NFSv4.2: define limits and sizes for user xattr handling Frank van der Linden
2020-03-12 20:35 ` Schumaker, Anna
2020-03-11 19:56 ` [PATCH 05/13] NFSv4.2: add client side XDR handling for extended attributes Frank van der Linden
2020-03-12 20:49 ` Schumaker, Anna
2020-03-11 19:56 ` [PATCH 06/13] nfs: define nfs_access_get_cached function Frank van der Linden
2020-03-11 19:56 ` [PATCH 07/13] NFSv4.2: query the extended attribute access bits Frank van der Linden
2020-03-11 19:56 ` [PATCH 08/13] nfs: modify update_changeattr to deal with regular files Frank van der Linden
2020-03-11 19:56 ` [PATCH 09/13] nfs: define and use the NFS_INO_INVALID_XATTR flag Frank van der Linden
2020-03-24 6:02 ` [nfs] c5654df66d: stress-ng.msg.ops_per_sec 15.5% improvement kernel test robot
2020-03-24 16:21 ` Frank van der Linden
2020-03-11 19:56 ` [PATCH 10/13] nfs: make the buf_to_pages_noslab function available to the nfs code Frank van der Linden
2020-03-12 20:36 ` Schumaker, Anna
2020-03-11 19:56 ` [PATCH 11/13] NFSv4.2: add the extended attribute proc functions Frank van der Linden
2020-03-11 19:56 ` [PATCH 12/13] NFSv4.2: hook in the user extended attribute handlers Frank van der Linden
2020-03-11 19:56 ` [PATCH 13/13] NFSv4.2: add client side xattr caching Frank van der Linden
2020-03-12 20:39 ` Schumaker, Anna
2020-03-12 20:48 ` Schumaker, Anna
2020-03-12 19:06 ` [PATCH 00/13] client side user xattr (RFC8276) support Mkrtchyan, Tigran
2020-03-12 20:09 ` Anna Schumaker
2020-03-16 15:50 ` Frank van der Linden
2020-03-17 23:03 ` Frank van der Linden
2020-03-19 14:39 ` J. Bruce Fields
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