From 50d0b1ad78b99aa776c3ddf9b1d45163fff435b9 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Wed, 30 Mar 2011 11:53:51 +0200 Subject: [PATCH] drbd: Remove some fixed header size assumptions Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_int.h | 15 +++------------ drivers/block/drbd/drbd_main.c | 25 +++++++++++++++---------- drivers/block/drbd/drbd_receiver.c | 29 +++++++++++++++++------------ 3 files changed, 35 insertions(+), 34 deletions(-) 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 @@ 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 /**********************************************************************/ 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 @@ 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) { diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 40fe719..74ed3ac2 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -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) -- 2.7.4