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Date: Tue, 05 Jun 2007 14:13:02 -0400
From: Trond Myklebust <trond.myklebust@....uio.no>
To: Jeff Layton <jlayton@...hat.com>
Cc: nfsv4@...ux-nfs.org, nfs@...ts.sourceforge.net,
linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [NFS] [PATCH 2/2] nfs4: on a O_EXCL OPEN make sure the SETATTR
sets the fields holding the verifier
On Tue, 2007-06-05 at 13:56 -0400, Jeff Layton wrote:
> The Linux NFS4 client simply skips over the bitmask in an O_EXCL open
> call and so it doesn't bother to reset any fields that may be holding
> the verifier. This patch has us save the first two words of the bitmask
> (which is all the current client has #defines for). The client then
> later checks this bitmask and turns on the appropriate flags in the
> sattr->ia_verify field for the following SETATTR call.
>
> This patch only currently checks to see if the server used the atime
> and mtime slots for the verifier (which is what the Linux server uses
> for this). I'm not sure of what other fields the server could
> reasonably use, but adding checks for others should be trivial.
>
> Signed-off-by: Jeff Layton <jlayton@...hat.com>
>
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 8e46e3e..34ddd66 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -955,6 +955,22 @@ static struct nfs4_state *nfs4_open_delegated(struct inode *inode, int flags, st
> }
>
> /*
> + * on an EXCLUSIVE create, the server should send back a bitmask with FATTR4-*
> + * fields corresponding to attributes that were used to store the verifier.
> + * Make sure we clobber those fields in the later setattr call
> + */
> +static inline void nfs4_exclusive_attrset (struct nfs4_opendata *opendata, struct iattr *sattr)
> +{
> + if ((opendata->o_res.attrset[1] & FATTR4_WORD1_TIME_ACCESS) &&
> + !(sattr->ia_valid & ATTR_ATIME_SET))
> + sattr->ia_valid |= ATTR_ATIME;
> +
> + if ((opendata->o_res.attrset[1] & FATTR4_WORD1_TIME_MODIFY) &&
> + !(sattr->ia_valid & ATTR_MTIME_SET))
> + sattr->ia_valid |= ATTR_MTIME;
> +}
> +
> +/*
> * Returns a referenced nfs4_state
> */
> static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, struct iattr *sattr, struct rpc_cred *cred, struct nfs4_state **res)
> @@ -985,6 +1001,9 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st
> if (status != 0)
> goto err_opendata_free;
>
> + if (opendata->o_arg.open_flags & O_EXCL)
> + nfs4_exclusive_attrset(opendata, sattr);
> +
> status = -ENOMEM;
> state = nfs4_opendata_to_nfs4_state(opendata);
> if (state == NULL)
> @@ -1787,6 +1806,7 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
> status = nfs4_do_setattr(state->inode, &fattr, sattr, state);
> if (status == 0)
> nfs_setattr_update_inode(state->inode, sattr);
> + nfs_refresh_inode(state->inode, &fattr);
^^^^ should be nfs_post_op_update_inode() to ensure
that the attribute cache gets invalidated if the server fails to return
the post-op attributes.
> }
> if (status == 0 && nd != NULL && (nd->flags & LOOKUP_OPEN))
> status = nfs4_intent_set_file(nd, dentry, state);
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index 4eb8a59..b281c83 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -3313,7 +3313,7 @@ static int decode_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
> static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
> {
> __be32 *p;
> - uint32_t bmlen;
> + uint32_t savewords, bmlen, i;
> int status;
>
> status = decode_op_hdr(xdr, OP_OPEN);
> @@ -3331,7 +3331,15 @@ static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
> goto xdr_error;
>
> READ_BUF(bmlen << 2);
> - p += bmlen;
> +
> + savewords = bmlen > NFS_OPENRES_ATTRSET_WORDS ?
> + NFS_OPENRES_ATTRSET_WORDS : bmlen;
^^^^ min_t(bmlen, NFS_OPENRES_ATTRSET_WORDS, uint32_t);
> +
> + for (i = 0; i < savewords; ++i)
> + READ32(res->attrset[i]);
> +
> + p += (bmlen - savewords);
> +
> return decode_delegation(xdr, res);
> xdr_error:
> dprintk("%s: Bitmap too large! Length = %u\n", __FUNCTION__, bmlen);
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index f8c55e5..f050a27 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -133,6 +133,7 @@ struct nfs_openargs {
> __u32 claim;
> };
>
> +#define NFS_OPENRES_ATTRSET_WORDS 2
Could you rename this to NFS4_BITMAP_SIZE and put it into
include/linux/nfs4.h, please.
> struct nfs_openres {
> nfs4_stateid stateid;
> struct nfs_fh fh;
> @@ -145,6 +146,7 @@ struct nfs_openres {
> nfs4_stateid delegation;
> __u32 do_recall;
> __u64 maxsize;
> + __u32 attrset[NFS_OPENRES_ATTRSET_WORDS];
> };
>
> /*
>
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