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>
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index ccc374c..cb16783 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -543,19 +543,10 @@
u32 offset; /* usecs the probe got sent after the reference time point */
} __packed;
-/* one bitmap packet, including the p_header,
- * should fit within one _architecture independend_ page.
- * so we need to use the fixed size 4KiB page size
- * most architectures have used for a long time.
+/*
+ * Bitmap packets need to fit within a single page on the sender and receiver,
+ * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
*/
-#define BM_PACKET_PAYLOAD_BYTES (4096 - sizeof(struct p_header))
-#define BM_PACKET_WORDS (BM_PACKET_PAYLOAD_BYTES/sizeof(long))
-#define BM_PACKET_VLI_BYTES_MAX (4096 - sizeof(struct p_compressed_bm))
-#if (PAGE_SIZE < 4096)
-/* drbd_send_bitmap / receive_bitmap would break horribly */
-#error "PAGE_SIZE too small"
-#endif
-
#define DRBD_SOCKET_BUFFER_SIZE 4096
/**********************************************************************/
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index e3dc84d..3ecbd49 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1100,8 +1100,9 @@
}
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 @@
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 @@
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 @@
} 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 @@
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 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) {
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 40fe719..74ed3ac 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3660,16 +3660,19 @@
* code upon failure.
*/
static int
-receive_bitmap_plain(struct drbd_conf *mdev, unsigned int data_size,
+receive_bitmap_plain(struct drbd_conf *mdev, unsigned int size,
struct p_header *h, struct bm_xfer_ctx *c)
{
unsigned long *buffer = (unsigned long *)h->payload;
- unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
- unsigned want = num_words * sizeof(long);
+ unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE -
+ drbd_header_size(mdev->tconn);
+ unsigned int num_words = min_t(size_t, data_size / sizeof(unsigned long),
+ c->bm_words - c->word_offset);
+ unsigned int want = num_words * sizeof(unsigned long);
int err;
- if (want != data_size) {
- dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
+ if (want != size) {
+ dev_err(DEV, "%s:want (%u) != size (%u)\n", __func__, want, size);
return -EIO;
}
if (want == 0)
@@ -3796,11 +3799,13 @@
const char *direction, struct bm_xfer_ctx *c)
{
/* what would it take to transfer it "plaintext" */
- unsigned plain = sizeof(struct p_header) *
- ((c->bm_words+BM_PACKET_WORDS-1)/BM_PACKET_WORDS+1)
- + c->bm_words * sizeof(long);
- unsigned total = c->bytes[0] + c->bytes[1];
- unsigned r;
+ unsigned int header_size = drbd_header_size(mdev->tconn);
+ unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
+ unsigned int plain =
+ header_size * (DIV_ROUND_UP(c->bm_words, data_size) + 1) +
+ c->bm_words * sizeof(unsigned long);
+ unsigned int total = c->bytes[0] + c->bytes[1];
+ unsigned int r;
/* total can not be zero. but just in case: */
if (total == 0)
@@ -3862,7 +3867,7 @@
* and the feature is enabled! */
struct p_compressed_bm *p;
- if (pi->size > BM_PACKET_PAYLOAD_BYTES) {
+ if (pi->size > DRBD_SOCKET_BUFFER_SIZE - drbd_header_size(tconn)) {
dev_err(DEV, "ReportCBitmap packet too large\n");
err = -EIO;
goto out;
@@ -3885,7 +3890,7 @@
}
c.packets[pi->cmd == P_BITMAP]++;
- c.bytes[pi->cmd == P_BITMAP] += sizeof(struct p_header) + pi->size;
+ c.bytes[pi->cmd == P_BITMAP] += drbd_header_size(tconn) + pi->size;
if (err <= 0) {
if (err < 0)