block/loop: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 18 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c674e5492ec4..f47dccbda1d4 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1624,30 +1624,17 @@ static int loop_add(struct loop_device **l, int i)
         if (!lo)
                 goto out;
 
-        if (!idr_pre_get(&loop_index_idr, GFP_KERNEL))
-                goto out_free_dev;
-
+        /* allocate id, if @id >= 0, we're requesting that specific id */
         if (i >= 0) {
-                int m;
-
-                /* create specific i in the index */
-                err = idr_get_new_above(&loop_index_idr, lo, i, &m);
-                if (err >= 0 && i != m) {
-                        idr_remove(&loop_index_idr, m);
+                err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL);
+                if (err == -ENOSPC)
                         err = -EEXIST;
-                }
-        } else if (i == -1) {
-                int m;
-
-                /* get next free nr */
-                err = idr_get_new(&loop_index_idr, lo, &m);
-                if (err >= 0)
-                        i = m;
         } else {
-                err = -EINVAL;
+                err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL);
         }
         if (err < 0)
                 goto out_free_dev;
+        i = err;
 
         lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
         if (!lo->lo_queue)