btrfs: use memdup_user()
Remove open-coded memdup_user().
Note this changes some GFP_NOFS to GFP_KERNEL, since copy_from_user() may
cause pagefault, it's pointless to pass GFP_NOFS to kmalloc().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 9744af9..a7acfe6 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -635,14 +635,9 @@
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- vol = kmalloc(sizeof(*vol), GFP_KERNEL);
- if (!vol)
- return -ENOMEM;
-
- if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
- ret = -EFAULT;
- goto out;
- }
+ vol = memdup_user((void __user *)arg, sizeof(*vol));
+ if (IS_ERR(vol))
+ return PTR_ERR(vol);
switch (cmd) {
case BTRFS_IOC_SCAN_DEV:
@@ -650,7 +645,7 @@
&btrfs_fs_type, &fs_devices);
break;
}
-out:
+
kfree(vol);
return ret;
}