diff options
| -rw-r--r-- | drivers/block/drbd/drbd_main.c | 3 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_nl.c | 20 |
2 files changed, 19 insertions, 4 deletions
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index c73376886e7a..1f6ac9202b66 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2659,9 +2659,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig * connect. */ .max_hw_sectors = DRBD_MAX_BIO_SIZE_SAFE >> 8, - .features = BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA | - BLK_FEAT_ROTATIONAL | - BLK_FEAT_STABLE_WRITES, }; device = minor_to_device(minor); diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 91f3b8afb63c..b502038be0a9 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1296,6 +1296,8 @@ void drbd_reconsider_queue_parameters(struct drbd_device *device, lim.max_segments = drbd_backing_dev_max_segments(device); } else { lim.max_segments = BLK_MAX_SEGMENTS; + lim.features = BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA | + BLK_FEAT_ROTATIONAL | BLK_FEAT_STABLE_WRITES; } lim.max_hw_sectors = new >> SECTOR_SHIFT; @@ -1318,8 +1320,24 @@ void drbd_reconsider_queue_parameters(struct drbd_device *device, lim.max_hw_discard_sectors = 0; } - if (bdev) + if (bdev) { blk_stack_limits(&lim, &b->limits, 0); + /* + * blk_set_stacking_limits() cleared the features, and + * blk_stack_limits() may or may not have inherited + * BLK_FEAT_STABLE_WRITES from the backing device. + * + * DRBD always requires stable writes because: + * 1. The same bio data is read for both local disk I/O and + * network transmission. If the page changes mid-flight, + * the local and remote copies could diverge. + * 2. When data integrity is enabled, DRBD calculates a + * checksum before sending the data. If the page changes + * between checksum calculation and transmission, the + * receiver will detect a checksum mismatch. + */ + lim.features |= BLK_FEAT_STABLE_WRITES; + } /* * If we can handle "zeroes" efficiently on the protocol, we want to do |