drbd: prepare receiving side for REQ_DISCARD

If the receiver needs to serve a discard request on a queue that does
not announce to be discard cabable, it falls back to do synchronous
blkdev_issue_zeroout().

We expect only "reasonably" large (up to one activity log extent?)
discard requests.

We do this to not to not block the receiver for too long in this
fallback code path, and to not set/clear too many bits inside one
spinlock_irq_save() in drbd_set_in_sync/drbd_set_out_of_sync,

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>

diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index 8dd09a7..8fc5d71 100644 (file)
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -845,7 +845,7 @@ void __drbd_set_in_sync(struct drbd_device *device, sector_t sector, int size,
        int wake_up = 0;
        unsigned long flags;
 
-       if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
+       if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_DISCARD_SIZE) {
                drbd_err(device, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n",
                                (unsigned long long)sector, size);
                return;
@@ -919,7 +919,7 @@ int __drbd_set_out_of_sync(struct drbd_device *device, sector_t sector, int size
        if (size == 0)
                return 0;
 
-       if (size < 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
+       if (size < 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_DISCARD_SIZE) {
                drbd_err(device, "sector: %llus, size: %d\n",
                        (unsigned long long)sector, size);
                return 0;
@@ -1286,7 +1286,7 @@ void drbd_rs_failed_io(struct drbd_device *device, sector_t sector, int size)
        sector_t esector, nr_sectors;
        int wake_up = 0;
 
-       if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
+       if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_DISCARD_SIZE) {
                drbd_err(device, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n",
                                (unsigned long long)sector, size);
                return;

diff --cc drivers/block/drbd/drbd_int.h
Simple merge

diff --cc drivers/block/drbd/drbd_protocol.h
Simple merge

diff --cc drivers/block/drbd/drbd_receiver.c
Simple merge

diff --cc drivers/block/drbd/drbd_worker.c
Simple merge