This adds support to pass through persistent reservation requests
similar to the existing ioctl handling, and with the same limitations,
e.g. devices may only have a single target attached.
This is mostly intended for multipathing.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/md/dm.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 123 insertions(+)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 017c712..4f5e655 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -24,6 +24,7 @@
#include <linux/ktime.h>
#include <linux/elevator.h> /* for rq_end_sector() */
#include <linux/blk-mq.h>
+#include <linux/pr.h>
#include <trace/events/block.h>
@@ -3544,11 +3545,133 @@ void dm_free_md_mempools(struct dm_md_mempools *pools)
kfree(pools);
}
+static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
+ u32 flags)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ struct dm_target *tgt;
+ fmode_t mode;
+ int srcu_idx, r;
+
+ r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_register)
+ r = ops->pr_register(bdev, old_key, new_key, flags);
+ else
+ r = -EOPNOTSUPP;
+
+ dm_put_live_table(md, srcu_idx);
+ return r;
+}
+
+static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
+ u32 flags)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ struct dm_target *tgt;
+ fmode_t mode;
+ int srcu_idx, r;
+
+ r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_reserve)
+ r = ops->pr_reserve(bdev, key, type, flags);
+ else
+ r = -EOPNOTSUPP;
+
+ dm_put_live_table(md, srcu_idx);
+ return r;
+}
+
+static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ struct dm_target *tgt;
+ fmode_t mode;
+ int srcu_idx, r;
+
+ r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_release)
+ r = ops->pr_release(bdev, key, type);
+ else
+ r = -EOPNOTSUPP;
+
+ dm_put_live_table(md, srcu_idx);
+ return r;
+}
+
+static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
+ enum pr_type type, bool abort)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ struct dm_target *tgt;
+ fmode_t mode;
+ int srcu_idx, r;
+
+ r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_preempt)
+ r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
+ else
+ r = -EOPNOTSUPP;
+
+ dm_put_live_table(md, srcu_idx);
+ return r;
+}
+
+static int dm_pr_clear(struct block_device *bdev, u64 key)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ struct dm_target *tgt;
+ fmode_t mode;
+ int srcu_idx, r;
+
+ r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_clear)
+ r = ops->pr_clear(bdev, key);
+ else
+ r = -EOPNOTSUPP;
+
+ dm_put_live_table(md, srcu_idx);
+ return r;
+}
+
+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,
+};
+
static const struct block_device_operations dm_blk_dops = {
.open = dm_blk_open,
.release = dm_blk_close,
.ioctl = dm_blk_ioctl,
.getgeo = dm_blk_getgeo,
+ .pr_ops = &dm_pr_ops,
.owner = THIS_MODULE
};
--
1.9.1
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