[PATCH] bcache: reduce redundant code in bch_cached_dev_run()

[Zhiqiang Liu]

In bch_cached_dev_run(), free(env[1])|free(env[2])|free(buf)
show up three times. This patch introduce out tag in
which free(env[1])|free(env[2])|free(buf) are only called
one time. If we need to call free() when errors occur,
we can set error code to ret, and then goto out tag directly.

Signed-off-by: Zhiqiang Liu <liuzhiqian...@huawei.com>
---
 drivers/md/bcache/super.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 71691f32959b..1a8748050087 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1052,6 +1052,7 @@ static int cached_dev_status_update(void *arg)

 int bch_cached_dev_run(struct cached_dev *dc)
 {
+       int ret = 0;
        struct bcache_device *d = &dc->disk;
        char *buf = kmemdup_nul(dc->sb.label, SB_LABEL_SIZE, GFP_KERNEL);
        char *env[] = {
@@ -1064,19 +1065,15 @@ int bch_cached_dev_run(struct cached_dev *dc)
        if (dc->io_disable) {
                pr_err("I/O disabled on cached dev %s\n",
                       dc->backing_dev_name);
-               kfree(env[1]);
-               kfree(env[2]);
-               kfree(buf);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }

        if (atomic_xchg(&dc->running, 1)) {
-               kfree(env[1]);
-               kfree(env[2]);
-               kfree(buf);
                pr_info("cached dev %s is running already\n",
                       dc->backing_dev_name);
-               return -EBUSY;
+               ret = -EBUSY;
+               goto out;
        }

        if (!d->c &&
@@ -1097,15 +1094,13 @@ int bch_cached_dev_run(struct cached_dev *dc)
         * only class / kset properties are persistent
         */
        kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
-       kfree(env[1]);
-       kfree(env[2]);
-       kfree(buf);

        if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
            sysfs_create_link(&disk_to_dev(d->disk)->kobj,
                              &d->kobj, "bcache")) {
                pr_err("Couldn't create bcache dev <-> disk sysfs symlinks\n");
-               return -ENOMEM;
+               ret = -ENOMEM;
+               goto out;
        }

        dc->status_update_thread = kthread_run(cached_dev_status_update,
@@ -1114,7 +1109,11 @@ int bch_cached_dev_run(struct cached_dev *dc)
                pr_warn("failed to create bcache_status_update kthread, 
continue to run without monitoring backing device status\n");
        }

-       return 0;
+out:
+       kfree(env[1]);
+       kfree(env[2]);
+       kfree(buf);
+       return ret;
 }

 /*
-- 
2.19.1