drbd: Remove some fixed header size assumptions (50d0b1ad) · Commits · 戴 / test

drivers/block/drbd/drbd_int.h

+3 −12

Original line number	Diff line number	Diff line
		@@ -543,19 +543,10 @@ struct p_delay_probe93 {
		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

		/**********************************************************************/

drivers/block/drbd/drbd_main.c

+15 −10

Original line number	Diff line number	Diff line
		@@ -1101,6 +1101,7 @@ 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,
		unsigned int size,
		struct bm_xfer_ctx *c)
		{
		struct bitstream bs;
		@@ -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) {

drivers/block/drbd/drbd_receiver.c

+17 −12

Original line number	Diff line number	Diff line
		@@ -3660,16 +3660,19 @@ static int receive_sync_uuid(struct drbd_tconn tconn, struct packet_info pi)
		* 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 @@ void INFO_bm_xfer_stats(struct drbd_conf *mdev,
		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 @@ static int receive_bitmap(struct drbd_tconn tconn, struct packet_info pi)
		* 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 @@ static int receive_bitmap(struct drbd_tconn tconn, struct packet_info pi)
		}

		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)

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