From: NeilBrown Each backing_dev needs to be able to report whether it is congested, either by modulating BDI_*_congested in ->state, or by defining a ->congested_fn. md/raid did neither of these. This patch add a congested_fn which simply checks all component devices to see if they are congested. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton --- drivers/md/linear.c | 15 +++++++++++++++ drivers/md/raid0.c | 17 +++++++++++++++++ 2 files changed, 32 insertions(+) diff -puN drivers/md/linear.c~md-define-backing_dev_infocongested_fn-for-raid0-and-linear drivers/md/linear.c --- a/drivers/md/linear.c~md-define-backing_dev_infocongested_fn-for-raid0-and-linear +++ a/drivers/md/linear.c @@ -111,6 +111,19 @@ static int linear_issue_flush(request_qu return ret; } +static int linear_congested(void *data, int bits) +{ + mddev_t *mddev = data; + linear_conf_t *conf = mddev_to_conf(mddev); + int i, ret = 0; + + for (i = 0; i < mddev->raid_disks && !ret ; i++) { + request_queue_t *q = bdev_get_queue(conf->disks[i].rdev->bdev); + ret |= bdi_congested(&q->backing_dev_info, bits); + } + return ret; +} + static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks) { linear_conf_t *conf; @@ -269,6 +282,8 @@ static int linear_run (mddev_t *mddev) blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec); mddev->queue->unplug_fn = linear_unplug; mddev->queue->issue_flush_fn = linear_issue_flush; + mddev->queue->backing_dev_info.congested_fn = linear_congested; + mddev->queue->backing_dev_info.congested_data = mddev; return 0; } diff -puN drivers/md/raid0.c~md-define-backing_dev_infocongested_fn-for-raid0-and-linear drivers/md/raid0.c --- a/drivers/md/raid0.c~md-define-backing_dev_infocongested_fn-for-raid0-and-linear +++ a/drivers/md/raid0.c @@ -60,6 +60,21 @@ static int raid0_issue_flush(request_que return ret; } +static int raid0_congested(void *data, int bits) +{ + mddev_t *mddev = data; + raid0_conf_t *conf = mddev_to_conf(mddev); + mdk_rdev_t **devlist = conf->strip_zone[0].dev; + int i, ret = 0; + + for (i = 0; i < mddev->raid_disks && !ret ; i++) { + request_queue_t *q = bdev_get_queue(devlist[i]->bdev); + + ret |= bdi_congested(&q->backing_dev_info, bits); + } + return ret; +} + static int create_strip_zones (mddev_t *mddev) { @@ -236,6 +251,8 @@ static int create_strip_zones (mddev_t * mddev->queue->unplug_fn = raid0_unplug; mddev->queue->issue_flush_fn = raid0_issue_flush; + mddev->queue->backing_dev_info.congested_fn = raid0_congested; + mddev->queue->backing_dev_info.congested_data = mddev; printk("raid0: done.\n"); return 0; _