dm: Add support for block PR read keys/reservation

This adds support in dm for the block PR read keys and read reservation
callouts.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230407200551.12660-7-michael.christie@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index eace45a..360439f 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -3114,6 +3114,8 @@ struct dm_pr {
        bool    fail_early;
        int     ret;
        enum pr_type type;
+       struct pr_keys *read_keys;
+       struct pr_held_reservation *rsv;
 };
 
 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
@@ -3346,12 +3348,79 @@ out:
        return r;
 }
 
+static int __dm_pr_read_keys(struct dm_target *ti, struct dm_dev *dev,
+                            sector_t start, sector_t len, void *data)
+{
+       struct dm_pr *pr = data;
+       const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
+
+       if (!ops || !ops->pr_read_keys) {
+               pr->ret = -EOPNOTSUPP;
+               return -1;
+       }
+
+       pr->ret = ops->pr_read_keys(dev->bdev, pr->read_keys);
+       if (!pr->ret)
+               return -1;
+
+       return 0;
+}
+
+static int dm_pr_read_keys(struct block_device *bdev, struct pr_keys *keys)
+{
+       struct dm_pr pr = {
+               .read_keys = keys,
+       };
+       int ret;
+
+       ret = dm_call_pr(bdev, __dm_pr_read_keys, &pr);
+       if (ret)
+               return ret;
+
+       return pr.ret;
+}
+
+static int __dm_pr_read_reservation(struct dm_target *ti, struct dm_dev *dev,
+                                   sector_t start, sector_t len, void *data)
+{
+       struct dm_pr *pr = data;
+       const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
+
+       if (!ops || !ops->pr_read_reservation) {
+               pr->ret = -EOPNOTSUPP;
+               return -1;
+       }
+
+       pr->ret = ops->pr_read_reservation(dev->bdev, pr->rsv);
+       if (!pr->ret)
+               return -1;
+
+       return 0;
+}
+
+static int dm_pr_read_reservation(struct block_device *bdev,
+                                 struct pr_held_reservation *rsv)
+{
+       struct dm_pr pr = {
+               .rsv = rsv,
+       };
+       int ret;
+
+       ret = dm_call_pr(bdev, __dm_pr_read_reservation, &pr);
+       if (ret)
+               return ret;
+
+       return pr.ret;
+}
+
 static const struct pr_ops dm_pr_ops = {
        .pr_register    = dm_pr_register,
        .pr_reserve     = dm_pr_reserve,
        .pr_release     = dm_pr_release,
        .pr_preempt     = dm_pr_preempt,
        .pr_clear       = dm_pr_clear,
+       .pr_read_keys   = dm_pr_read_keys,
+       .pr_read_reservation = dm_pr_read_reservation,
 };
 
 static const struct block_device_operations dm_blk_dops = {