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authorPhilipp Reisner <philipp.reisner@linbit.com>2016-06-14 00:26:13 +0200
committerJens Axboe <axboe@fb.com>2016-06-14 05:43:04 +0200
commit700ca8c04a0f4402f379055eec97351e0d6c0087 (patch)
treec69ed1d2afe9c805a018e04baec8694043b9882b /drivers/block/drbd/drbd_worker.c
parentdrbd: Kill code duplication (diff)
downloadlinux-700ca8c04a0f4402f379055eec97351e0d6c0087.tar.xz
linux-700ca8c04a0f4402f379055eec97351e0d6c0087.zip
drbd: Implement handling of thinly provisioned storage on resync target nodes
If during resync we read only zeroes for a range of sectors assume that these secotors can be discarded on the sync target node. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/drbd/drbd_worker.c')
-rw-r--r--drivers/block/drbd/drbd_worker.c29
1 files changed, 28 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 51fab978eb61..dd85433315d2 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1036,6 +1036,30 @@ int w_e_end_data_req(struct drbd_work *w, int cancel)
return err;
}
+static bool all_zero(struct drbd_peer_request *peer_req)
+{
+ struct page *page = peer_req->pages;
+ unsigned int len = peer_req->i.size;
+
+ page_chain_for_each(page) {
+ unsigned int l = min_t(unsigned int, len, PAGE_SIZE);
+ unsigned int i, words = l / sizeof(long);
+ unsigned long *d;
+
+ d = kmap_atomic(page);
+ for (i = 0; i < words; i++) {
+ if (d[i]) {
+ kunmap_atomic(d);
+ return false;
+ }
+ }
+ kunmap_atomic(d);
+ len -= l;
+ }
+
+ return true;
+}
+
/**
* w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUEST
* @w: work object.
@@ -1064,7 +1088,10 @@ int w_e_end_rsdata_req(struct drbd_work *w, int cancel)
} else if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
if (likely(device->state.pdsk >= D_INCONSISTENT)) {
inc_rs_pending(device);
- err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req);
+ if (peer_req->flags & EE_RS_THIN_REQ && all_zero(peer_req))
+ err = drbd_send_rs_deallocated(peer_device, peer_req);
+ else
+ err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req);
} else {
if (__ratelimit(&drbd_ratelimit_state))
drbd_err(device, "Not sending RSDataReply, "