NFSv4; Clean up XDR encoding of type bitmap4

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 72 insertions, 94 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 6b08f6b1addf..80c5b519fd6a 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -958,6 +958,35 @@ static void encode_uint64(struct xdr_stream *xdr, u64 n)
         WARN_ON_ONCE(xdr_stream_encode_u64(xdr, n) < 0);
 }
 
+static ssize_t xdr_encode_bitmap4(struct xdr_stream *xdr,
+                const __u32 *bitmap, size_t len)
+{
+        ssize_t ret;
+
+        /* Trim empty words */
+        while (len > 0 && bitmap[len-1] == 0)
+                len--;
+        ret = xdr_stream_encode_uint32_array(xdr, bitmap, len);
+        if (WARN_ON_ONCE(ret < 0))
+                return ret;
+        return len;
+}
+
+static size_t mask_bitmap4(const __u32 *bitmap, const __u32 *mask,
+                __u32 *res, size_t len)
+{
+        size_t i;
+        __u32 tmp;
+
+        while (len > 0 && (bitmap[len-1] == 0 || mask[len-1] == 0))
+                len--;
+        for (i = len; i-- > 0;) {
+                tmp = bitmap[i] & mask[i];
+                res[i] = tmp;
+        }
+        return len;
+}
+
 static void encode_nfs4_seqid(struct xdr_stream *xdr,
                 const struct nfs_seqid *seqid)
 {
@@ -1200,85 +1229,45 @@ static void encode_create(struct xdr_stream *xdr, const struct nfs4_create_arg *
                         create->server, create->server->attr_bitmask);
 }
 
-static void encode_getattr_one(struct xdr_stream *xdr, uint32_t bitmap, struct compound_hdr *hdr)
-{
-        __be32 *p;
-
-        encode_op_hdr(xdr, OP_GETATTR, decode_getattr_maxsz, hdr);
-        p = reserve_space(xdr, 8);
-        *p++ = cpu_to_be32(1);
-        *p = cpu_to_be32(bitmap);
-}
-
-static void encode_getattr_two(struct xdr_stream *xdr, uint32_t bm0, uint32_t bm1, struct compound_hdr *hdr)
-{
-        __be32 *p;
-
-        encode_op_hdr(xdr, OP_GETATTR, decode_getattr_maxsz, hdr);
-        p = reserve_space(xdr, 12);
-        *p++ = cpu_to_be32(2);
-        *p++ = cpu_to_be32(bm0);
-        *p = cpu_to_be32(bm1);
-}
-
-static void
-encode_getattr_three(struct xdr_stream *xdr,
-                     uint32_t bm0, uint32_t bm1, uint32_t bm2,
-                     struct compound_hdr *hdr)
+static void encode_getattr(struct xdr_stream *xdr,
+                const __u32 *bitmap, const __u32 *mask, size_t len,
+                struct compound_hdr *hdr)
 {
-        __be32 *p;
+        __u32 masked_bitmap[nfs4_fattr_bitmap_maxsz];
 
         encode_op_hdr(xdr, OP_GETATTR, decode_getattr_maxsz, hdr);
-        if (bm2) {
-                p = reserve_space(xdr, 16);
-                *p++ = cpu_to_be32(3);
-                *p++ = cpu_to_be32(bm0);
-                *p++ = cpu_to_be32(bm1);
-                *p = cpu_to_be32(bm2);
-        } else if (bm1) {
-                p = reserve_space(xdr, 12);
-                *p++ = cpu_to_be32(2);
-                *p++ = cpu_to_be32(bm0);
-                *p = cpu_to_be32(bm1);
-        } else {
-                p = reserve_space(xdr, 8);
-                *p++ = cpu_to_be32(1);
-                *p = cpu_to_be32(bm0);
+        if (mask) {
+                if (WARN_ON_ONCE(len > ARRAY_SIZE(masked_bitmap)))
+                        len = ARRAY_SIZE(masked_bitmap);
+                len = mask_bitmap4(bitmap, mask, masked_bitmap, len);
+                bitmap = masked_bitmap;
         }
+        xdr_encode_bitmap4(xdr, bitmap, len);
 }
 
 static void encode_getfattr(struct xdr_stream *xdr, const u32* bitmask, struct compound_hdr *hdr)
 {
-        encode_getattr_three(xdr, bitmask[0] & nfs4_fattr_bitmap[0],
-                           bitmask[1] & nfs4_fattr_bitmap[1],
-                           bitmask[2] & nfs4_fattr_bitmap[2],
-                           hdr);
+        encode_getattr(xdr, nfs4_fattr_bitmap, bitmask,
+                        ARRAY_SIZE(nfs4_fattr_bitmap), hdr);
 }
 
 static void encode_getfattr_open(struct xdr_stream *xdr, const u32 *bitmask,
                                  const u32 *open_bitmap,
                                  struct compound_hdr *hdr)
 {
-        encode_getattr_three(xdr,
-                             bitmask[0] & open_bitmap[0],
-                             bitmask[1] & open_bitmap[1],
-                             bitmask[2] & open_bitmap[2],
-                             hdr);
+        encode_getattr(xdr, open_bitmap, bitmask, 3, hdr);
 }
 
 static void encode_fsinfo(struct xdr_stream *xdr, const u32* bitmask, struct compound_hdr *hdr)
 {
-        encode_getattr_three(xdr,
-                             bitmask[0] & nfs4_fsinfo_bitmap[0],
-                             bitmask[1] & nfs4_fsinfo_bitmap[1],
-                             bitmask[2] & nfs4_fsinfo_bitmap[2],
-                             hdr);
+        encode_getattr(xdr, nfs4_fsinfo_bitmap, bitmask,
+                        ARRAY_SIZE(nfs4_fsinfo_bitmap), hdr);
 }
 
 static void encode_fs_locations(struct xdr_stream *xdr, const u32* bitmask, struct compound_hdr *hdr)
 {
-        encode_getattr_two(xdr, bitmask[0] & nfs4_fs_locations_bitmap[0],
-                           bitmask[1] & nfs4_fs_locations_bitmap[1], hdr);
+        encode_getattr(xdr, nfs4_fs_locations_bitmap, bitmask,
+                        ARRAY_SIZE(nfs4_fs_locations_bitmap), hdr);
 }
 
 static void encode_getfh(struct xdr_stream *xdr, struct compound_hdr *hdr)
@@ -2559,13 +2548,17 @@ static void nfs4_xdr_enc_getacl(struct rpc_rqst *req, struct xdr_stream *xdr,
         struct compound_hdr hdr = {
                 .minorversion = nfs4_xdr_minorversion(&args->seq_args),
         };
+        const __u32 nfs4_acl_bitmap[1] = {
+                [0] = FATTR4_WORD0_ACL,
+        };
         uint32_t replen;
 
         encode_compound_hdr(xdr, req, &hdr);
         encode_sequence(xdr, &args->seq_args, &hdr);
         encode_putfh(xdr, args->fh, &hdr);
         replen = hdr.replen + op_decode_hdr_maxsz;
-        encode_getattr_two(xdr, FATTR4_WORD0_ACL, 0, &hdr);
+        encode_getattr(xdr, nfs4_acl_bitmap, NULL,
+                        ARRAY_SIZE(nfs4_acl_bitmap), &hdr);
 
         xdr_inline_pages(&req->rq_rcv_buf, replen << 2,
                 args->acl_pages, 0, args->acl_len);
@@ -2644,8 +2637,8 @@ static void nfs4_xdr_enc_pathconf(struct rpc_rqst *req, struct xdr_stream *xdr,
         encode_compound_hdr(xdr, req, &hdr);
         encode_sequence(xdr, &args->seq_args, &hdr);
         encode_putfh(xdr, args->fh, &hdr);
-        encode_getattr_one(xdr, args->bitmask[0] & nfs4_pathconf_bitmap[0],
-                           &hdr);
+        encode_getattr(xdr, nfs4_pathconf_bitmap, args->bitmask,
+                        ARRAY_SIZE(nfs4_pathconf_bitmap), &hdr);
         encode_nops(&hdr);
 }
 
@@ -2663,8 +2656,8 @@ static void nfs4_xdr_enc_statfs(struct rpc_rqst *req, struct xdr_stream *xdr,
         encode_compound_hdr(xdr, req, &hdr);
         encode_sequence(xdr, &args->seq_args, &hdr);
         encode_putfh(xdr, args->fh, &hdr);
-        encode_getattr_two(xdr, args->bitmask[0] & nfs4_statfs_bitmap[0],
-                           args->bitmask[1] & nfs4_statfs_bitmap[1], &hdr);
+        encode_getattr(xdr, nfs4_statfs_bitmap, args->bitmask,
+                        ARRAY_SIZE(nfs4_statfs_bitmap), &hdr);
         encode_nops(&hdr);
 }
 
@@ -2684,7 +2677,7 @@ static void nfs4_xdr_enc_server_caps(struct rpc_rqst *req,
         encode_compound_hdr(xdr, req, &hdr);
         encode_sequence(xdr, &args->seq_args, &hdr);
         encode_putfh(xdr, args->fhandle, &hdr);
-        encode_getattr_three(xdr, bitmask[0], bitmask[1], bitmask[2], &hdr);
+        encode_getattr(xdr, bitmask, NULL, 3, &hdr);
         encode_nops(&hdr);
 }
 
@@ -3218,34 +3211,27 @@ static int decode_ace(struct xdr_stream *xdr, void *ace)
         return -EIO;
 }
 
-static int decode_attr_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
+static ssize_t
+decode_bitmap4(struct xdr_stream *xdr, uint32_t *bitmap, size_t sz)
 {
-        uint32_t bmlen;
-        __be32 *p;
-
-        p = xdr_inline_decode(xdr, 4);
-        if (unlikely(!p))
-                goto out_overflow;
-        bmlen = be32_to_cpup(p);
+        ssize_t ret;
 
-        bitmap[0] = bitmap[1] = bitmap[2] = 0;
-        p = xdr_inline_decode(xdr, (bmlen << 2));
-        if (unlikely(!p))
-                goto out_overflow;
-        if (bmlen > 0) {
-                bitmap[0] = be32_to_cpup(p++);
-                if (bmlen > 1) {
-                        bitmap[1] = be32_to_cpup(p++);
-                        if (bmlen > 2)
-                                bitmap[2] = be32_to_cpup(p);
-                }
-        }
-        return 0;
-out_overflow:
+        ret = xdr_stream_decode_uint32_array(xdr, bitmap, sz);
+        if (likely(ret >= 0))
+                return ret;
+        if (ret == -EMSGSIZE)
+                return sz;
         print_overflow_msg(__func__, xdr);
         return -EIO;
 }
 
+static int decode_attr_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
+{
+        ssize_t ret;
+        ret = decode_bitmap4(xdr, bitmap, 3);
+        return ret < 0 ? ret : 0;
+}
+
 static int decode_attr_length(struct xdr_stream *xdr, uint32_t *attrlen, unsigned int *savep)
 {
         __be32 *p;
@@ -5471,21 +5457,13 @@ decode_savefh(struct xdr_stream *xdr)
 
 static int decode_setattr(struct xdr_stream *xdr)
 {
-        __be32 *p;
-        uint32_t bmlen;
         int status;
 
         status = decode_op_hdr(xdr, OP_SETATTR);
         if (status)
                 return status;
-        p = xdr_inline_decode(xdr, 4);
-        if (unlikely(!p))
-                goto out_overflow;
-        bmlen = be32_to_cpup(p);
-        p = xdr_inline_decode(xdr, bmlen << 2);
-        if (likely(p))
+        if (decode_bitmap4(xdr, NULL, 0) >= 0)
                 return 0;
-out_overflow:
         print_overflow_msg(__func__, xdr);
         return -EIO;
 }