dm: add support for passing through persistent reservations

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@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 77066a1999844935abfdb972fecefb6e21e98514..aaa6caa46a9f2dbceaf3d9c1aac92037b3b731b2 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1682,7 +1682,7 @@ out:
  *---------------------------------------------------------------*/
 static struct target_type multipath_target = {
        .name = "multipath",
-       .version = {1, 9, 0},
+       .version = {1, 10, 0},
        .module = THIS_MODULE,
        .ctr = multipath_ctr,
        .dtr = multipath_dtr,

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 9b3fe5be0cee5013d53bab2b2e5e5dea1cf7cc04..c31ca8bc6af5b24ffed7e9c18ba607d80c396a39 100644 (file)
--- 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>
 
@@ -3553,11 +3554,133 @@ 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
 };
 

diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h
index d34611e35a30f10995d19cc4ae80aeb4a9547211..30afd0a23c4b0d3b0c70b5d2778f3988f01d03a2 100644 (file)
--- a/include/uapi/linux/dm-ioctl.h
+++ b/include/uapi/linux/dm-ioctl.h
@@ -267,9 +267,9 @@ enum {
 #define DM_DEV_SET_GEOMETRY    _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 
 #define DM_VERSION_MAJOR       4
-#define DM_VERSION_MINOR       33
+#define DM_VERSION_MINOR       34
 #define DM_VERSION_PATCHLEVEL  0
-#define DM_VERSION_EXTRA       "-ioctl (2015-8-18)"
+#define DM_VERSION_EXTRA       "-ioctl (2015-10-28)"
 
 /* Status bits */
 #define DM_READONLY_FLAG       (1 << 0) /* In/Out */