loop: don't call loop_lookup before adding a loop device

loop_add returns the right error if the slot wasn't available.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210623145908.92973-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d587ad2..5b77c1e 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2388,14 +2388,12 @@ out:
 static void loop_probe(dev_t dev)
 {
        int idx = MINOR(dev) >> part_shift;
-       struct loop_device *lo;
 
        if (max_loop && idx >= max_loop)
                return;
 
        mutex_lock(&loop_ctl_mutex);
-       if (loop_lookup(&lo, idx) < 0)
-               loop_add(idx);
+       loop_add(idx);
        mutex_unlock(&loop_ctl_mutex);
 }
 
@@ -2412,11 +2410,6 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
        ret = -ENOSYS;
        switch (cmd) {
        case LOOP_CTL_ADD:
-               ret = loop_lookup(&lo, parm);
-               if (ret >= 0) {
-                       ret = -EEXIST;
-                       break;
-               }
                ret = loop_add(parm);
                break;
        case LOOP_CTL_REMOVE: