drbd: Preparing to use p_header96 for all packets

recv_bm_rle_bits() should not make any assumptions abou the layout
of the packet header

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index fbf93826ef0e76172e81aa9becc54d8407f28874..12fdd737cb69c052fe73b4660f618b3a8fdd01ea 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3393,7 +3393,8 @@ receive_bitmap_plain(struct drbd_conf *mdev, unsigned int data_size,
 static int
 recv_bm_rle_bits(struct drbd_conf *mdev,
                struct p_compressed_bm *p,
-               struct bm_xfer_ctx *c)
+                struct bm_xfer_ctx *c,
+                unsigned int len)
 {
        struct bitstream bs;
        u64 look_ahead;
@@ -3401,7 +3402,6 @@ recv_bm_rle_bits(struct drbd_conf *mdev,
        u64 tmp;
        unsigned long s = c->bit_offset;
        unsigned long e;
-       int len = be16_to_cpu(p->head.length) - (sizeof(*p) - sizeof(p->head));
        int toggle = DCBP_get_start(p);
        int have;
        int bits;
@@ -3458,10 +3458,11 @@ recv_bm_rle_bits(struct drbd_conf *mdev,
 static int
 decode_bitmap_c(struct drbd_conf *mdev,
                struct p_compressed_bm *p,
-               struct bm_xfer_ctx *c)
+               struct bm_xfer_ctx *c,
+               unsigned int len)
 {
        if (DCBP_get_code(p) == RLE_VLI_Bits)
-               return recv_bm_rle_bits(mdev, p, c);
+               return recv_bm_rle_bits(mdev, p, c, len);
 
        /* other variants had been implemented for evaluation,
         * but have been dropped as this one turned out to be "best"
@@ -3560,7 +3561,7 @@ static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packets cmd, unsigne
                                dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
                                goto out;
                        }
-                       err = decode_bitmap_c(mdev, p, &c);
+                       err = decode_bitmap_c(mdev, p, &c, data_size);
                } else {
                        dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
                        goto out;