dm: convert to idr_alloc()

Convert to the much saner new idr interface.

Only compile tested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c80cb0674e2377979a151e0767b4e6f44bd852ed..c5347533992c95750385df3ac5147985c7bef2fd 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1801,62 +1801,38 @@ static void free_minor(int minor)
  */
 static int specific_minor(int minor)
 {
-       int r, m;
+       int r;
 
        if (minor >= (1 << MINORBITS))
                return -EINVAL;
 
-       r = idr_pre_get(&_minor_idr, GFP_KERNEL);
-       if (!r)
-               return -ENOMEM;
-
+       idr_preload(GFP_KERNEL);
        spin_lock(&_minor_lock);
 
-       if (idr_find(&_minor_idr, minor)) {
-               r = -EBUSY;
-               goto out;
-       }
-
-       r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);
-       if (r)
-               goto out;
+       r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
 
-       if (m != minor) {
-               idr_remove(&_minor_idr, m);
-               r = -EBUSY;
-               goto out;
-       }
-
-out:
        spin_unlock(&_minor_lock);
-       return r;
+       idr_preload_end();
+       if (r < 0)
+               return r == -ENOSPC ? -EBUSY : r;
+       return 0;
 }
 
 static int next_free_minor(int *minor)
 {
-       int r, m;
-
-       r = idr_pre_get(&_minor_idr, GFP_KERNEL);
-       if (!r)
-               return -ENOMEM;
+       int r;
 
+       idr_preload(GFP_KERNEL);
        spin_lock(&_minor_lock);
 
-       r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m);
-       if (r)
-               goto out;
-
-       if (m >= (1 << MINORBITS)) {
-               idr_remove(&_minor_idr, m);
-               r = -ENOSPC;
-               goto out;
-       }
-
-       *minor = m;
+       r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
 
-out:
        spin_unlock(&_minor_lock);
-       return r;
+       idr_preload_end();
+       if (r < 0)
+               return r;
+       *minor = r;
+       return 0;
 }
 
 static const struct block_device_operations dm_blk_dops;