nfs: nfs4xdr: introduce decode_opaque_fixed and decode_stateid helpers

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 40 insertions, 31 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 8255ec7079d4..86e6983ef4fa 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3290,19 +3290,34 @@ static int decode_access(struct xdr_stream *xdr, struct nfs4_accessres *access)
         return 0;
 }
 
-static int decode_close(struct xdr_stream *xdr, struct nfs_closeres *res)
+static int decode_opaque_fixed(struct xdr_stream *xdr, void *buf, size_t len)
 {
         __be32 *p;
+
+        p = xdr_inline_decode(xdr, len);
+        if (likely(p)) {
+                memcpy(buf, p, len);
+                return 0;
+        }
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+}
+
+static int decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+        return decode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
+}
+
+static int decode_close(struct xdr_stream *xdr, struct nfs_closeres *res)
+{
         int status;
 
         status = decode_op_hdr(xdr, OP_CLOSE);
         if (status != -EIO)
                 nfs_increment_open_seqid(status, res->seqid);
-        if (status)
-                return status;
-        READ_BUF(NFS4_STATEID_SIZE);
-        COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
-        return 0;
+        if (!status)
+                status = decode_stateid(xdr, &res->stateid);
+        return status;
 }
 
 static int decode_commit(struct xdr_stream *xdr, struct nfs_writeres *res)
@@ -3635,15 +3650,15 @@ static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
 
 static int decode_lock(struct xdr_stream *xdr, struct nfs_lock_res *res)
 {
-        __be32 *p;
         int status;
 
         status = decode_op_hdr(xdr, OP_LOCK);
         if (status == -EIO)
                 goto out;
         if (status == 0) {
-                READ_BUF(NFS4_STATEID_SIZE);
-                COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
+                status = decode_stateid(xdr, &res->stateid);
+                if (unlikely(status))
+                        goto out;
         } else if (status == -NFS4ERR_DENIED)
                 status = decode_lock_denied(xdr, NULL);
         if (res->open_seqid != NULL)
@@ -3664,16 +3679,13 @@ static int decode_lockt(struct xdr_stream *xdr, struct nfs_lockt_res *res)
 
 static int decode_locku(struct xdr_stream *xdr, struct nfs_locku_res *res)
 {
-        __be32 *p;
         int status;
 
         status = decode_op_hdr(xdr, OP_LOCKU);
         if (status != -EIO)
                 nfs_increment_lock_seqid(status, res->seqid);
-        if (status == 0) {
-                READ_BUF(NFS4_STATEID_SIZE);
-                COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
-        }
+        if (status == 0)
+                status = decode_stateid(xdr, &res->stateid);
         return status;
 }
 
@@ -3706,6 +3718,7 @@ static int decode_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
 {
         __be32 *p;
         uint32_t delegation_type;
+        int status;
 
         READ_BUF(4);
         delegation_type = be32_to_cpup(p++);
@@ -3713,8 +3726,10 @@ static int decode_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
                 res->delegation_type = 0;
                 return 0;
         }
-        READ_BUF(NFS4_STATEID_SIZE+4);
-        COPYMEM(res->delegation.data, NFS4_STATEID_SIZE);
+        status = decode_stateid(xdr, &res->delegation);
+        if (unlikely(status))
+                return status;
+        READ_BUF(4);
         res->do_recall = be32_to_cpup(p++);
 
         switch (delegation_type) {
@@ -3738,10 +3753,10 @@ static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
         status = decode_op_hdr(xdr, OP_OPEN);
         if (status != -EIO)
                 nfs_increment_open_seqid(status, res->seqid);
-        if (status)
+        if (!status)
+                status = decode_stateid(xdr, &res->stateid);
+        if (unlikely(status))
                 return status;
-        READ_BUF(NFS4_STATEID_SIZE);
-        COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
 
         decode_change_info(xdr, &res->cinfo);
 
@@ -3766,32 +3781,26 @@ xdr_error:
 
 static int decode_open_confirm(struct xdr_stream *xdr, struct nfs_open_confirmres *res)
 {
-        __be32 *p;
         int status;
 
         status = decode_op_hdr(xdr, OP_OPEN_CONFIRM);
         if (status != -EIO)
                 nfs_increment_open_seqid(status, res->seqid);
-        if (status)
-                return status;
-        READ_BUF(NFS4_STATEID_SIZE);
-        COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
-        return 0;
+        if (!status)
+                status = decode_stateid(xdr, &res->stateid);
+        return status;
 }
 
 static int decode_open_downgrade(struct xdr_stream *xdr, struct nfs_closeres *res)
 {
-        __be32 *p;
         int status;
 
         status = decode_op_hdr(xdr, OP_OPEN_DOWNGRADE);
         if (status != -EIO)
                 nfs_increment_open_seqid(status, res->seqid);
-        if (status)
-                return status;
-        READ_BUF(NFS4_STATEID_SIZE);
-        COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
-        return 0;
+        if (!status)
+                status = decode_stateid(xdr, &res->stateid);
+        return status;
 }
 
 static int decode_putfh(struct xdr_stream *xdr)