diff options
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 50 |
1 files changed, 16 insertions, 34 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 1725a54042bb..2efdb0d67460 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7227,7 +7227,6 @@ static int raid5_run(struct mddev *mddev) if (mddev->queue) { int chunk_size; - bool discard_supported = true; /* read-ahead size must cover two whole stripes, which * is 2 * (datadisks) * chunksize where 'n' is the * number of raid devices @@ -7263,12 +7262,6 @@ static int raid5_run(struct mddev *mddev) blk_queue_max_discard_sectors(mddev->queue, 0xfffe * STRIPE_SECTORS); - /* - * unaligned part of discard request will be ignored, so can't - * guarantee discard_zeroes_data - */ - mddev->queue->limits.discard_zeroes_data = 0; - blk_queue_max_write_same_sectors(mddev->queue, 0); blk_queue_max_write_zeroes_sectors(mddev->queue, 0); @@ -7277,35 +7270,24 @@ static int raid5_run(struct mddev *mddev) rdev->data_offset << 9); disk_stack_limits(mddev->gendisk, rdev->bdev, rdev->new_data_offset << 9); - /* - * discard_zeroes_data is required, otherwise data - * could be lost. Consider a scenario: discard a stripe - * (the stripe could be inconsistent if - * discard_zeroes_data is 0); write one disk of the - * stripe (the stripe could be inconsistent again - * depending on which disks are used to calculate - * parity); the disk is broken; The stripe data of this - * disk is lost. - */ - if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) || - !bdev_get_queue(rdev->bdev)-> - limits.discard_zeroes_data) - discard_supported = false; - /* Unfortunately, discard_zeroes_data is not currently - * a guarantee - just a hint. So we only allow DISCARD - * if the sysadmin has confirmed that only safe devices - * are in use by setting a module parameter. - */ - if (!devices_handle_discard_safely) { - if (discard_supported) { - pr_info("md/raid456: discard support disabled due to uncertainty.\n"); - pr_info("Set raid456.devices_handle_discard_safely=Y to override.\n"); - } - discard_supported = false; - } } - if (discard_supported && + /* + * zeroing is required, otherwise data + * could be lost. Consider a scenario: discard a stripe + * (the stripe could be inconsistent if + * discard_zeroes_data is 0); write one disk of the + * stripe (the stripe could be inconsistent again + * depending on which disks are used to calculate + * parity); the disk is broken; The stripe data of this + * disk is lost. + * + * We only allow DISCARD if the sysadmin has confirmed that + * only safe devices are in use by setting a module parameter. + * A better idea might be to turn DISCARD into WRITE_ZEROES + * requests, as that is required to be safe. + */ + if (devices_handle_discard_safely && mddev->queue->limits.max_discard_sectors >= (stripe >> 9) && mddev->queue->limits.discard_granularity >= stripe) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, |