[PATCH 08/14] drbd: receive_bitmap(): Use the pre-allocated receive buffer

From: Philipp Reisner
Date: Wed Sep 07 2011 - 12:47:26 EST


From: Andreas Gruenbacher <agruen@xxxxxxxxxx>

Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
---
drivers/block/drbd/drbd_receiver.c | 21 +++++----------------
1 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 3738d56..e5099db 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3572,8 +3572,9 @@ static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packet cmd,
*/
static int
receive_bitmap_plain(struct drbd_conf *mdev, unsigned int data_size,
- unsigned long *buffer, struct bm_xfer_ctx *c)
+ 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);
int err;
@@ -3748,7 +3749,6 @@ static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
unsigned int data_size)
{
struct bm_xfer_ctx c;
- void *buffer;
int err;
struct p_header *h = mdev->tconn->data.rbuf;
struct packet_info pi;
@@ -3757,15 +3757,6 @@ static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
/* you are supposed to send additional out-of-sync information
* if you actually set bits during this phase */

- /* maybe we should use some per thread scratch page,
- * and allocate that during initial device creation? */
- buffer = (unsigned long *) __get_free_page(GFP_NOIO);
- if (!buffer) {
- dev_err(DEV, "failed to allocate one page buffer in %s\n", __func__);
- err = -ENOMEM;
- goto out;
- }
-
c = (struct bm_xfer_ctx) {
.bm_bits = drbd_bm_bits(mdev),
.bm_words = drbd_bm_words(mdev),
@@ -3773,7 +3764,7 @@ static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,

for(;;) {
if (cmd == P_BITMAP) {
- err = receive_bitmap_plain(mdev, data_size, buffer, &c);
+ err = receive_bitmap_plain(mdev, data_size, h, &c);
} else if (cmd == P_COMPRESSED_BITMAP) {
/* MAYBE: sanity check that we speak proto >= 90,
* and the feature is enabled! */
@@ -3784,9 +3775,8 @@ static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
err = -EIO;
goto out;
}
- /* use the page buff */
- p = buffer;
- memcpy(p, h, sizeof(*h));
+
+ p = mdev->tconn->data.rbuf;
err = drbd_recv_all(mdev->tconn, p->head.payload, data_size);
if (err)
goto out;
@@ -3840,7 +3830,6 @@ static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
drbd_bm_unlock(mdev);
if (!err && mdev->state.conn == C_WF_BITMAP_S)
drbd_start_resync(mdev, C_SYNC_SOURCE);
- free_page((unsigned long) buffer);
return err;
}

--
1.7.4.1

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