In-Reply-To: <4C97379E.5050301@panasas.com>
References: <1284779874-10499-1-git-send-email-iisaman@netapp.com>
	<1284779874-10499-6-git-send-email-iisaman@netapp.com>
	<4C97379E.5050301@panasas.com>
Date: Mon, 20 Sep 2010 09:46:35 -0400
Message-ID: <AANLkTi=HGUYnbhUDkj7YfsrhKwAoWueHOk=_0Cana4za@mail.gmail.com>
Subject: Re: [PATCH 05/12] RFC: nfs: ask for layouttypes during fsinfo call
From: Fred Isaman <iisaman@netapp.com>
To: Benny Halevy <bhalevy@panasas.com>
Cc: linux-nfs@vger.kernel.org
Content-Type: text/plain; charset=ISO-8859-1
Sender: linux-nfs-owner@vger.kernel.org
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On Mon, Sep 20, 2010 at 6:29 AM, Benny Halevy <bhalevy@panasas.com> wrote:
> On 2010-09-18 05:17, Fred Isaman wrote:
>> From: The pNFS Team <linux-nfs@vger.kernel.org>
>>
>> This information will be used to determine which layout driver,
>> if any, to use for subsequent IO on this filesystem. ?Each driver
>> is assigned an integer id, with 0 reserved to indicate no driver.
>>
>> The server can in theory return multiple ids. ?However, our current
>> client implementation only notes the first entry and ignores the
>> rest.
>>
>> Signed-off-by: TBD - melding/reorganization of several patches
>> ---
>> ?fs/nfs/nfs4proc.c ? ? ? | ? ?2 +-
>> ?fs/nfs/nfs4xdr.c ? ? ? ?| ? 57 +++++++++++++++++++++++++++++++++++++++++++++++
>> ?include/linux/nfs_xdr.h | ? ?1 +
>> ?3 files changed, 59 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
>> index c46e45e..c0d9ff4 100644
>> --- a/fs/nfs/nfs4proc.c
>> +++ b/fs/nfs/nfs4proc.c
>> @@ -129,7 +129,7 @@ const u32 nfs4_fsinfo_bitmap[2] = { FATTR4_WORD0_MAXFILESIZE
>> ? ? ? ? ? ? ? ? ? ? ? | FATTR4_WORD0_MAXREAD
>> ? ? ? ? ? ? ? ? ? ? ? | FATTR4_WORD0_MAXWRITE
>> ? ? ? ? ? ? ? ? ? ? ? | FATTR4_WORD0_LEASE_TIME,
>> - ? ? ? ? ? ? ? ? ? ? 0
>> + ? ? ? ? ? ? ? ? ? ? FATTR4_WORD1_FS_LAYOUT_TYPES
>
> Note that originally (9170cf5 pnfs_submit: set and unset pnfs layoutdriver modules),
> we set this only under CONFIG_NFS_V4_1, but it should be ok to ask for
> it anyhow.
>
> Benny
>

Yes.

Fred

>> ?};
>>
>> ?const u32 nfs4_fs_locations_bitmap[2] = {
>> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
>> index b0bd7ef..e138237 100644
>> --- a/fs/nfs/nfs4xdr.c
>> +++ b/fs/nfs/nfs4xdr.c
>> @@ -3868,6 +3868,60 @@ xdr_error:
>> ? ? ? return status;
>> ?}
>>
>> +/*
>> + * Decode potentially multiple layout types. Currently we only support
>> + * one layout driver per file system.
>> + */
>> +static int decode_first_pnfs_layout_type(struct xdr_stream *xdr,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?uint32_t *layouttype)
>> +{
>> + ? ? uint32_t *p;
>> + ? ? int num;
>> +
>> + ? ? p = xdr_inline_decode(xdr, 4);
>> + ? ? if (unlikely(!p))
>> + ? ? ? ? ? ? goto out_overflow;
>> + ? ? num = be32_to_cpup(p);
>> +
>> + ? ? /* pNFS is not supported by the underlying file system */
>> + ? ? if (num == 0) {
>> + ? ? ? ? ? ? *layouttype = 0;
>> + ? ? ? ? ? ? return 0;
>> + ? ? }
>> + ? ? if (num > 1)
>> + ? ? ? ? ? ? printk(KERN_INFO "%s: Warning: Multiple pNFS layout drivers "
>> + ? ? ? ? ? ? ? ? ? ? "per filesystem not supported\n", __func__);
>> +
>> + ? ? /* Decode and set first layout type, move xdr->p past unused types */
>> + ? ? p = xdr_inline_decode(xdr, num * 4);
>> + ? ? if (unlikely(!p))
>> + ? ? ? ? ? ? goto out_overflow;
>> + ? ? *layouttype = be32_to_cpup(p);
>> + ? ? return 0;
>> +out_overflow:
>> + ? ? print_overflow_msg(__func__, xdr);
>> + ? ? return -EIO;
>> +}
>> +
>> +/*
>> + * The type of file system exported.
>> + * Note we must ensure that layouttype is set in any non-error case.
>> + */
>> +static int decode_attr_pnfstype(struct xdr_stream *xdr, uint32_t *bitmap,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? uint32_t *layouttype)
>> +{
>> + ? ? int status = 0;
>> +
>> + ? ? dprintk("%s: bitmap is %x\n", __func__, bitmap[1]);
>> + ? ? if (unlikely(bitmap[1] & (FATTR4_WORD1_FS_LAYOUT_TYPES - 1U)))
>> + ? ? ? ? ? ? return -EIO;
>> + ? ? if (bitmap[1] & FATTR4_WORD1_FS_LAYOUT_TYPES) {
>> + ? ? ? ? ? ? status = decode_first_pnfs_layout_type(xdr, layouttype);
>> + ? ? ? ? ? ? bitmap[1] &= ~FATTR4_WORD1_FS_LAYOUT_TYPES;
>> + ? ? } else
>> + ? ? ? ? ? ? *layouttype = 0;
>> + ? ? return status;
>> +}
>>
>> ?static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
>> ?{
>> @@ -3894,6 +3948,9 @@ static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
>> ? ? ? if ((status = decode_attr_maxwrite(xdr, bitmap, &fsinfo->wtmax)) != 0)
>> ? ? ? ? ? ? ? goto xdr_error;
>> ? ? ? fsinfo->wtpref = fsinfo->wtmax;
>> + ? ? status = decode_attr_pnfstype(xdr, bitmap, &fsinfo->layouttype);
>> + ? ? if (status)
>> + ? ? ? ? ? ? goto xdr_error;
>>
>> ? ? ? status = verify_attr_len(xdr, savep, attrlen);
>> ?xdr_error:
>> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
>> index 172df83..7d68a5c 100644
>> --- a/include/linux/nfs_xdr.h
>> +++ b/include/linux/nfs_xdr.h
>> @@ -113,6 +113,7 @@ struct nfs_fsinfo {
>> ? ? ? __u32 ? ? ? ? ? ? ? ? ? dtpref; /* pref. readdir transfer size */
>> ? ? ? __u64 ? ? ? ? ? ? ? ? ? maxfilesize;
>> ? ? ? __u32 ? ? ? ? ? ? ? ? ? lease_time; /* in seconds */
>> + ? ? __u32 ? ? ? ? ? ? ? ? ? layouttype; /* supported pnfs layout driver */
>> ?};
>>
>> ?struct nfs_fsstat {
> --
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