nfsd4: simplify nfsd4_encode_fattr interface slightly

It seems slightly simpler to make nfsd4_encode_fattr rather than its
callers responsible for advancing the write pointer on success.

(Also: the count == 0 check in the verify case looks superfluous.
Running out of buffer space is really the only reason fattr encoding
should fail with eresource.)

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

3 files changed, 13 insertions, 17 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 9d1c5dba2bbb..ae73175e6e68 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -993,14 +993,15 @@ _nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         if (!buf)
                 return nfserr_jukebox;
 
+        p = buf;
         status = nfsd4_encode_fattr(&cstate->current_fh,
                                     cstate->current_fh.fh_export,
-                                    cstate->current_fh.fh_dentry, buf,
-                                    &count, verify->ve_bmval,
+                                    cstate->current_fh.fh_dentry, &p,
+                                    count, verify->ve_bmval,
                                     rqstp, 0);
 
         /* this means that nfsd4_encode_fattr() ran out of space */
-        if (status == nfserr_resource && count == 0)
+        if (status == nfserr_resource)
                 status = nfserr_not_same;
         if (status)
                 goto out_kfree;
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0dc11586682f..fcb5bed99c33 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2006,12 +2006,11 @@ static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
  * ourselves.
  *
- * @countp is the buffer size in _words_; upon successful return this becomes
- * replaced with the number of words written.
+ * countp is the buffer size in _words_
  */
 __be32
 nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
-                struct dentry *dentry, __be32 *buffer, int *countp, u32 *bmval,
+                struct dentry *dentry, __be32 **buffer, int count, u32 *bmval,
                 struct svc_rqst *rqstp, int ignore_crossmnt)
 {
         u32 bmval0 = bmval[0];
@@ -2020,12 +2019,12 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
         struct kstat stat;
         struct svc_fh tempfh;
         struct kstatfs statfs;
-        int buflen = *countp << 2;
+        int buflen = count << 2;
         __be32 *attrlenp;
         u32 dummy;
         u64 dummy64;
         u32 rdattr_err = 0;
-        __be32 *p = buffer;
+        __be32 *p = *buffer;
         __be32 status;
         int err;
         int aclsupport = 0;
@@ -2431,7 +2430,7 @@ out_acl:
         }
 
         *attrlenp = htonl((char *)p - (char *)attrlenp - 4);
-        *countp = p - buffer;
+        *buffer = p;
         status = nfs_ok;
 
 out:
@@ -2443,7 +2442,6 @@ out_nfserr:
         status = nfserrno(err);
         goto out;
 out_resource:
-        *countp = 0;
         status = nfserr_resource;
         goto out;
 out_serverfault:
@@ -2462,7 +2460,7 @@ static inline int attributes_need_mount(u32 *bmval)
 
 static __be32
 nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
-                const char *name, int namlen, __be32 *p, int *buflen)
+                const char *name, int namlen, __be32 **p, int buflen)
 {
         struct svc_export *exp = cd->rd_fhp->fh_export;
         struct dentry *dentry;
@@ -2568,10 +2566,9 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
         p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
         p = xdr_encode_array(p, name, namlen);      /* name length & name */
 
-        nfserr = nfsd4_encode_dirent_fattr(cd, name, namlen, p, &buflen);
+        nfserr = nfsd4_encode_dirent_fattr(cd, name, namlen, &p, buflen);
         switch (nfserr) {
         case nfs_ok:
-                p += buflen;
                 break;
         case nfserr_resource:
                 nfserr = nfserr_toosmall;
@@ -2698,10 +2695,8 @@ nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
 
         buflen = resp->end - resp->p - (COMPOUND_ERR_SLACK_SPACE >> 2);
         nfserr = nfsd4_encode_fattr(fhp, fhp->fh_export, fhp->fh_dentry,
-                                    resp->p, &buflen, getattr->ga_bmval,
+                                    &resp->p, buflen, getattr->ga_bmval,
                                     resp->rqstp, 0);
-        if (!nfserr)
-                resp->p += buflen;
         return nfserr;
 }
 
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 0889bfb43dc9..546f8983ecf1 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -563,7 +563,7 @@ __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *, u32);
 void nfsd4_encode_operation(struct nfsd4_compoundres *, struct nfsd4_op *);
 void nfsd4_encode_replay(struct nfsd4_compoundres *resp, struct nfsd4_op *op);
 __be32 nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
-                       struct dentry *dentry, __be32 *buffer, int *countp,
+                       struct dentry *dentry, __be32 **buffer, int countp,
                        u32 *bmval, struct svc_rqst *, int ignore_crossmnt);
 extern __be32 nfsd4_setclientid(struct svc_rqst *rqstp,
                 struct nfsd4_compound_state *,