dm: refactor ioctl handling
This moves the call to blkdev_ioctl and the argument checking to DM core
code, and only leaves a callout to find the block device to operate on
in the targets. This simplifies the code and allows us to pass through
ioctl-like command using other methods in the next patch.
Also split out a helper around calling the prepare_ioctl method that
will be reused for persistent reservation handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 77ebb98..9b3fe5b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -555,18 +555,16 @@
return dm_get_geometry(md, geo);
}
-static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
- unsigned int cmd, unsigned long arg)
+static int dm_get_live_table_for_ioctl(struct mapped_device *md,
+ struct dm_target **tgt, struct block_device **bdev,
+ fmode_t *mode, int *srcu_idx)
{
- struct mapped_device *md = bdev->bd_disk->private_data;
- int srcu_idx;
struct dm_table *map;
- struct dm_target *tgt;
- int r = -ENOTTY;
+ int r;
retry:
- map = dm_get_live_table(md, &srcu_idx);
-
+ r = -ENOTTY;
+ map = dm_get_live_table(md, srcu_idx);
if (!map || !dm_table_get_size(map))
goto out;
@@ -574,8 +572,9 @@
if (dm_table_get_num_targets(map) != 1)
goto out;
- tgt = dm_table_get_target(map, 0);
- if (!tgt->type->ioctl)
+ *tgt = dm_table_get_target(map, 0);
+
+ if (!(*tgt)->type->prepare_ioctl)
goto out;
if (dm_suspended_md(md)) {
@@ -583,16 +582,46 @@
goto out;
}
- r = tgt->type->ioctl(tgt, cmd, arg);
+ r = (*tgt)->type->prepare_ioctl(*tgt, bdev, mode);
+ if (r < 0)
+ goto out;
+
+ return r;
out:
- dm_put_live_table(md, srcu_idx);
-
+ dm_put_live_table(md, *srcu_idx);
if (r == -ENOTCONN) {
msleep(10);
goto retry;
}
+ return r;
+}
+static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ struct dm_target *tgt;
+ int srcu_idx, r;
+
+ r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+ if (r < 0)
+ return r;
+
+ if (r > 0) {
+ /*
+ * Target determined this ioctl is being issued against
+ * a logical partition of the parent bdev; so extra
+ * validation is needed.
+ */
+ r = scsi_verify_blk_ioctl(NULL, cmd);
+ if (r)
+ goto out;
+ }
+
+ r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+out:
+ dm_put_live_table(md, srcu_idx);
return r;
}