staging/fwserial: Simplify max payload calculation

[firefly-linux-kernel-4.4.55.git] / drivers / md / linear.c

diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index fa211d80fc0a1e4e37603b1455184cbee7da6e56..21014836bdbf2286eba4fd02effbc4efcd9db625 100644 (file)
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -138,6 +138,7 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
        struct linear_conf *conf;
        struct md_rdev *rdev;
        int i, cnt;
+       bool discard_supported = false;
 
        conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
                        GFP_KERNEL);
@@ -171,6 +172,8 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
                conf->array_sectors += rdev->sectors;
                cnt++;
 
+               if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+                       discard_supported = true;
        }
        if (cnt != raid_disks) {
                printk(KERN_ERR "md/linear:%s: not enough drives present. Aborting!\n",
@@ -178,6 +181,11 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
                goto out;
        }
 
+       if (!discard_supported)
+               queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+       else
+               queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+
        /*
         * Here we calculate the device offsets.
         */
@@ -244,7 +252,9 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
        if (!newconf)
                return -ENOMEM;
 
-       oldconf = rcu_dereference(mddev->private);
+       oldconf = rcu_dereference_protected(mddev->private,
+                                           lockdep_is_held(
+                                                   &mddev->reconfig_mutex));
        mddev->raid_disks++;
        rcu_assign_pointer(mddev->private, newconf);
        md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
@@ -256,7 +266,10 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
 
 static int linear_stop (struct mddev *mddev)
 {
-       struct linear_conf *conf = mddev->private;
+       struct linear_conf *conf =
+               rcu_dereference_protected(mddev->private,
+                                         lockdep_is_held(
+                                                 &mddev->reconfig_mutex));
 
        /*
         * We do not require rcu protection here since
@@ -326,6 +339,14 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
        bio->bi_sector = bio->bi_sector - start_sector
                + tmp_dev->rdev->data_offset;
        rcu_read_unlock();
+
+       if (unlikely((bio->bi_rw & REQ_DISCARD) &&
+                    !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) {
+               /* Just ignore it */
+               bio_endio(bio, 0);
+               return;
+       }
+
        generic_make_request(bio);
 }