drbd: Remove some fixed header size assumptions

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

1 files changed, 15 insertions, 10 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index e3dc84dcd67e..3ecbd4908cdc 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1100,8 +1100,9 @@ static void dcbp_set_pad_bits(struct p_compressed_bm *p, int n)
 }
 
 int fill_bitmap_rle_bits(struct drbd_conf *mdev,
-        struct p_compressed_bm *p,
-        struct bm_xfer_ctx *c)
+                         struct p_compressed_bm *p,
+                         unsigned int size,
+                         struct bm_xfer_ctx *c)
 {
         struct bitstream bs;
         unsigned long plain_bits;
@@ -1120,8 +1121,8 @@ int fill_bitmap_rle_bits(struct drbd_conf *mdev,
                 return 0; /* nothing to do. */
 
         /* use at most thus many bytes */
-        bitstream_init(&bs, p->code, BM_PACKET_VLI_BYTES_MAX, 0);
-        memset(p->code, 0, BM_PACKET_VLI_BYTES_MAX);
+        bitstream_init(&bs, p->code, size, 0);
+        memset(p->code, 0, size);
         /* plain bits covered in this code string */
         plain_bits = 0;
 
@@ -1203,11 +1204,11 @@ static int
 send_bitmap_rle_or_plain(struct drbd_conf *mdev, struct bm_xfer_ctx *c)
 {
         struct drbd_socket *sock = &mdev->tconn->data;
+        unsigned int header_size = drbd_header_size(mdev->tconn);
         struct p_compressed_bm *p = sock->sbuf;
-        unsigned long num_words;
         int len, err;
 
-        len = fill_bitmap_rle_bits(mdev, p, c);
+        len = fill_bitmap_rle_bits(mdev, p, DRBD_SOCKET_BUFFER_SIZE - sizeof(*p) /* FIXME */, c);
         if (len < 0)
                 return -EIO;
 
@@ -1224,9 +1225,14 @@ send_bitmap_rle_or_plain(struct drbd_conf *mdev, struct bm_xfer_ctx *c)
         } else {
                 /* was not compressible.
                  * send a buffer full of plain text bits instead. */
+                unsigned int data_size;
+                unsigned long num_words;
                 struct p_header *h = sock->sbuf;
-                num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
-                len = num_words * sizeof(long);
+
+                data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
+                num_words = min_t(size_t, data_size / sizeof(unsigned long),
+                                  c->bm_words - c->word_offset);
+                len = num_words * sizeof(unsigned long);
                 if (len)
                         drbd_bm_get_lel(mdev, c->word_offset, num_words,
                                         (unsigned long *)h->payload);
@@ -1236,7 +1242,7 @@ send_bitmap_rle_or_plain(struct drbd_conf *mdev, struct bm_xfer_ctx *c)
                 c->bit_offset = c->word_offset * BITS_PER_LONG;
 
                 c->packets[1]++;
-                c->bytes[1] += sizeof(struct p_header80) + len;
+                c->bytes[1] += header_size + len;
 
                 if (c->bit_offset > c->bm_bits)
                         c->bit_offset = c->bm_bits;
@@ -2550,7 +2556,6 @@ int __init drbd_init(void)
 {
         int err;
 
-        BUILD_BUG_ON(sizeof(struct p_header80) != sizeof(struct p_header95));
         BUILD_BUG_ON(sizeof(struct p_connection_features) != 80);
 
         if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {