loop: move loop_ctl_mutex locking into loop_add
Move acquiring and releasing loop_ctl_mutex from the callers into
loop_add.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c3c6cfd..c18e293 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2247,9 +2247,12 @@ static int loop_add(int i)
lo = kzalloc(sizeof(*lo), GFP_KERNEL);
if (!lo)
goto out;
-
lo->lo_state = Lo_unbound;
+ err = mutex_lock_killable(&loop_ctl_mutex);
+ if (err)
+ goto out_free_dev;
+
/* allocate id, if @id >= 0, we're requesting that specific id */
if (i >= 0) {
err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL);
@@ -2259,7 +2262,7 @@ static int loop_add(int i)
err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL);
}
if (err < 0)
- goto out_free_dev;
+ goto out_unlock;
i = err;
err = -ENOMEM;
@@ -2326,12 +2329,15 @@ static int loop_add(int i)
disk->queue = lo->lo_queue;
sprintf(disk->disk_name, "loop%d", i);
add_disk(disk);
- return lo->lo_number;
+ mutex_unlock(&loop_ctl_mutex);
+ return i;
out_cleanup_tags:
blk_mq_free_tag_set(&lo->tag_set);
out_free_idr:
idr_remove(&loop_index_idr, i);
+out_unlock:
+ mutex_unlock(&loop_ctl_mutex);
out_free_dev:
kfree(lo);
out:
@@ -2391,22 +2397,7 @@ static void loop_probe(dev_t dev)
if (max_loop && idx >= max_loop)
return;
-
- mutex_lock(&loop_ctl_mutex);
loop_add(idx);
- mutex_unlock(&loop_ctl_mutex);
-}
-
-static int loop_control_add(int idx)
-{
- int ret;
-
- ret = mutex_lock_killable(&loop_ctl_mutex);
- if (ret)
- return ret;
- ret = loop_add(idx);
- mutex_unlock(&loop_ctl_mutex);
- return ret;
}
static int loop_control_remove(int idx)
@@ -2450,11 +2441,11 @@ static int loop_control_get_free(int idx)
if (ret)
return ret;
ret = loop_lookup(&lo, -1);
- if (ret < 0)
- ret = loop_add(-1);
mutex_unlock(&loop_ctl_mutex);
- return ret;
+ if (ret >= 0)
+ return ret;
+ return loop_add(-1);
}
static long loop_control_ioctl(struct file *file, unsigned int cmd,
@@ -2462,7 +2453,7 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
{
switch (cmd) {
case LOOP_CTL_ADD:
- return loop_control_add(parm);
+ return loop_add(parm);
case LOOP_CTL_REMOVE:
return loop_control_remove(parm);
case LOOP_CTL_GET_FREE:
@@ -2543,10 +2534,8 @@ static int __init loop_init(void)
}
/* pre-create number of devices given by config or max_loop */
- mutex_lock(&loop_ctl_mutex);
for (i = 0; i < nr; i++)
loop_add(i);
- mutex_unlock(&loop_ctl_mutex);
printk(KERN_INFO "loop: module loaded\n");
return 0;
