2021-03-06 02:54:45

by Zhiqiang Liu

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


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 <[email protected]>
---
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