MD: raid1 changes to allow use by device mapper

MD RAID1: Changes to allow RAID1 to be used by device-mapper (dm-raid.c)

Added the necessary congestion function and conditionalize calls requiring an
array 'queue' or 'gendisk'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 5d096096f9584972a9da2197ed1bef9303edf95f..f7431b6d8447df5979c0b80a5ded841f61a16cc1 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -497,21 +497,19 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio)
        return best_disk;
 }
 
-static int raid1_congested(void *data, int bits)
+int md_raid1_congested(mddev_t *mddev, int bits)
 {
-       mddev_t *mddev = data;
        conf_t *conf = mddev->private;
        int i, ret = 0;
 
-       if (mddev_congested(mddev, bits))
-               return 1;
-
        rcu_read_lock();
        for (i = 0; i < mddev->raid_disks; i++) {
                mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
                if (rdev && !test_bit(Faulty, &rdev->flags)) {
                        struct request_queue *q = bdev_get_queue(rdev->bdev);
 
+                       BUG_ON(!q);
+
                        /* Note the '|| 1' - when read_balance prefers
                         * non-congested targets, it can be removed
                         */
@@ -524,7 +522,15 @@ static int raid1_congested(void *data, int bits)
        rcu_read_unlock();
        return ret;
 }
+EXPORT_SYMBOL_GPL(md_raid1_congested);
 
+static int raid1_congested(void *data, int bits)
+{
+       mddev_t *mddev = data;
+
+       return mddev_congested(mddev, bits) ||
+               md_raid1_congested(mddev, bits);
+}
 
 static void flush_pending_writes(conf_t *conf)
 {
@@ -1972,6 +1978,8 @@ static int run(mddev_t *mddev)
                return PTR_ERR(conf);
 
        list_for_each_entry(rdev, &mddev->disks, same_set) {
+               if (!mddev->gendisk)
+                       continue;
                disk_stack_limits(mddev->gendisk, rdev->bdev,
                                  rdev->data_offset << 9);
                /* as we don't honour merge_bvec_fn, we must never risk
@@ -2013,8 +2021,10 @@ static int run(mddev_t *mddev)
 
        md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
 
-       mddev->queue->backing_dev_info.congested_fn = raid1_congested;
-       mddev->queue->backing_dev_info.congested_data = mddev;
+       if (mddev->queue) {
+               mddev->queue->backing_dev_info.congested_fn = raid1_congested;
+               mddev->queue->backing_dev_info.congested_data = mddev;
+       }
        return md_integrity_register(mddev);
 }
 

diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index 5fc4ca1af8639b5a61a6a17901866fe0987effcc..e743a64fac4f10f2dbc27f2c194658fdd35f3fa7 100644 (file)
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -126,4 +126,6 @@ struct r1bio_s {
  */
 #define        R1BIO_Returned 6
 
+extern int md_raid1_congested(mddev_t *mddev, int bits);
+
 #endif