NFS: Account for XDR pad of buf->pages

Certain NFS results (eg. READLINK) might expect a data payload that
is not an exact multiple of 4 bytes. In this case, XDR encoding
is required to pad that payload so its length on the wire is a
multiple of 4 bytes. The constants that define the maximum size of
each NFS result do not appear to account for this extra word.

In each case where the data payload is to be received into pages:

- 1 word is added to the size of the receive buffer allocated by
  call_allocate

- rpc_inline_rcv_pages subtracts 1 word from @hdrsize so that the
  extra buffer space falls into the rcv_buf's tail iovec

- If buf->pagelen is word-aligned, an XDR pad is not needed and
  is thus removed from the tail

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 1dcd0feda32dd1e8fa87f6bdb264c85ac6e103fa..a7ed29de0a406274390e3284701b46ef1d389e64 100644 (file)
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -56,11 +56,11 @@
 
 #define NFS_attrstat_sz                (1+NFS_fattr_sz)
 #define NFS_diropres_sz                (1+NFS_fhandle_sz+NFS_fattr_sz)
-#define NFS_readlinkres_sz     (2)
-#define NFS_readres_sz         (1+NFS_fattr_sz+1)
+#define NFS_readlinkres_sz     (2+1)
+#define NFS_readres_sz         (1+NFS_fattr_sz+1+1)
 #define NFS_writeres_sz         (NFS_attrstat_sz)
 #define NFS_stat_sz            (1)
-#define NFS_readdirres_sz      (1)
+#define NFS_readdirres_sz      (1+1)
 #define NFS_statfsres_sz       (1+NFS_info_sz)
 
 static int nfs_stat_to_errno(enum nfs_stat);

diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index a54dcf4bfb1d32c487781d7641a353fd14901b1b..110358f4986d781aa964416212e15fc112a2305e 100644 (file)
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -69,13 +69,13 @@
 #define NFS3_removeres_sz      (NFS3_setattrres_sz)
 #define NFS3_lookupres_sz      (1+NFS3_fh_sz+(2 * NFS3_post_op_attr_sz))
 #define NFS3_accessres_sz      (1+NFS3_post_op_attr_sz+1)
-#define NFS3_readlinkres_sz    (1+NFS3_post_op_attr_sz+1)
-#define NFS3_readres_sz                (1+NFS3_post_op_attr_sz+3)
+#define NFS3_readlinkres_sz    (1+NFS3_post_op_attr_sz+1+1)
+#define NFS3_readres_sz                (1+NFS3_post_op_attr_sz+3+1)
 #define NFS3_writeres_sz       (1+NFS3_wcc_data_sz+4)
 #define NFS3_createres_sz      (1+NFS3_fh_sz+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
 #define NFS3_renameres_sz      (1+(2 * NFS3_wcc_data_sz))
 #define NFS3_linkres_sz                (1+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
-#define NFS3_readdirres_sz     (1+NFS3_post_op_attr_sz+2)
+#define NFS3_readdirres_sz     (1+NFS3_post_op_attr_sz+2+1)
 #define NFS3_fsstatres_sz      (1+NFS3_post_op_attr_sz+13)
 #define NFS3_fsinfores_sz      (1+NFS3_post_op_attr_sz+12)
 #define NFS3_pathconfres_sz    (1+NFS3_post_op_attr_sz+6)
@@ -85,7 +85,7 @@
 #define ACL3_setaclargs_sz     (NFS3_fh_sz+1+ \
                                XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
 #define ACL3_getaclres_sz      (1+NFS3_post_op_attr_sz+1+ \
-                               XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
+                               XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)+1)
 #define ACL3_setaclres_sz      (1+NFS3_post_op_attr_sz)
 
 static int nfs3_stat_to_errno(enum nfs_stat);
@@ -1629,7 +1629,7 @@ static int nfs3_xdr_dec_read3res(struct rpc_rqst *req, struct xdr_stream *xdr,
        result->op_status = status;
        if (status != NFS3_OK)
                goto out_status;
-       result->replen = 3 + ((xdr_stream_pos(xdr) - pos) >> 2);
+       result->replen = 4 + ((xdr_stream_pos(xdr) - pos) >> 2);
        error = decode_read3resok(xdr, result);
 out:
        return error;

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index d0fa18df32ea4a75fcf7a8ae0b49b436914461d0..6d9d5e2f630804f41cfe99d192a1d62f6dff7ec5 100644 (file)
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -215,14 +215,14 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
                                 nfs4_fattr_bitmap_maxsz)
 #define encode_read_maxsz      (op_encode_hdr_maxsz + \
                                 encode_stateid_maxsz + 3)
-#define decode_read_maxsz      (op_decode_hdr_maxsz + 2)
+#define decode_read_maxsz      (op_decode_hdr_maxsz + 2 + 1)
 #define encode_readdir_maxsz   (op_encode_hdr_maxsz + \
                                 2 + encode_verifier_maxsz + 5 + \
                                nfs4_label_maxsz)
 #define decode_readdir_maxsz   (op_decode_hdr_maxsz + \
-                                decode_verifier_maxsz)
+                                decode_verifier_maxsz + 1)
 #define encode_readlink_maxsz  (op_encode_hdr_maxsz)
-#define decode_readlink_maxsz  (op_decode_hdr_maxsz + 1)
+#define decode_readlink_maxsz  (op_decode_hdr_maxsz + 1 + 1)
 #define encode_write_maxsz     (op_encode_hdr_maxsz + \
                                 encode_stateid_maxsz + 4)
 #define decode_write_maxsz     (op_decode_hdr_maxsz + \
@@ -284,14 +284,14 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
 #define decode_delegreturn_maxsz (op_decode_hdr_maxsz)
 #define encode_getacl_maxsz    (encode_getattr_maxsz)
 #define decode_getacl_maxsz    (op_decode_hdr_maxsz + \
-                                nfs4_fattr_bitmap_maxsz + 1)
+                                nfs4_fattr_bitmap_maxsz + 1 + 1)
 #define encode_setacl_maxsz    (op_encode_hdr_maxsz + \
                                 encode_stateid_maxsz + 3)
 #define decode_setacl_maxsz    (decode_setattr_maxsz)
 #define encode_fs_locations_maxsz \
                                (encode_getattr_maxsz)
 #define decode_fs_locations_maxsz \
-                               (0)
+                               (1)
 #define encode_secinfo_maxsz   (op_encode_hdr_maxsz + nfs4_name_maxsz)
 #define decode_secinfo_maxsz   (op_decode_hdr_maxsz + 1 + ((NFS_MAX_SECFLAVORS * (16 + GSS_OID_MAX_LEN)) / 4))
 
@@ -392,12 +392,13 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
                                1 /* opaque devaddr4 length */ + \
                                  /* devaddr4 payload is read into page */ \
                                1 /* notification bitmap length */ + \
-                               1 /* notification bitmap, word 0 */)
+                               1 /* notification bitmap, word 0 */ + \
+                               1 /* possible XDR padding */)
 #define encode_layoutget_maxsz (op_encode_hdr_maxsz + 10 + \
                                encode_stateid_maxsz)
 #define decode_layoutget_maxsz (op_decode_hdr_maxsz + 8 + \
                                decode_stateid_maxsz + \
-                               XDR_QUADLEN(PNFS_LAYOUT_MAXSIZE))
+                               XDR_QUADLEN(PNFS_LAYOUT_MAXSIZE) + 1)
 #define encode_layoutcommit_maxsz (op_encode_hdr_maxsz +          \
                                2 /* offset */ + \
                                2 /* length */ + \

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index f780605fffe00334688bd20f7f79edd38a2acaf5..4ea38b029e2f4e194192116f3a37be433d63c9d5 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1177,7 +1177,11 @@ void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
                             unsigned int base, unsigned int len,
                             unsigned int hdrsize)
 {
-       hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack;
+       /* Subtract one to force an extra word of buffer space for the
+        * payload's XDR pad to fall into the rcv_buf's tail iovec.
+        */
+       hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack - 1;
+
        xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
        trace_rpc_reply_pages(req);
 }

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 7cca51560442dc0357435cfeaef559be164b3268..aa8177ddcbda81e157fd886f2696da1dd8186c60 100644 (file)
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -189,6 +189,8 @@ xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
 
        tail->iov_base = buf + offset;
        tail->iov_len = buflen - offset;
+       if ((xdr->page_len & 3) == 0)
+               tail->iov_len -= sizeof(__be32);
 
        xdr->buflen += len;
 }