Commit 0145eed6 authored by Yongpeng Yang's avatar Yongpeng Yang Committed by Jaegeuk Kim
Browse files

f2fs: Constrain the modification range of dir_level in the sysfs 



The {struct f2fs_sb_info}->dir_level can be modified through the sysfs
interface, but its value range is not limited. If the value exceeds
MAX_DIR_HASH_DEPTH and the mount options include "noinline_dentry",
the following error will occur:
[root@fedora ~]# mount -o noinline_dentry /dev/sdb  /mnt/sdb/
[root@fedora ~]# echo 128 > /sys/fs/f2fs/sdb/dir_level
[root@fedora ~]# cd /mnt/sdb/
[root@fedora sdb]# mkdir test
[root@fedora sdb]# cd test/
[root@fedora test]# mkdir test
mkdir: cannot create directory 'test': Argument list too long

Signed-off-by: default avatarYongpeng Yang <yangyongpeng1@oppo.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 94e7eb42

fs/f2fs/sysfs.c

+7 −0
Original line number Diff line number Diff line
@@ -741,6 +741,13 @@ static ssize_t __sbi_store(struct f2fs_attr *a, 
		return count;

	}



	if (!strcmp(a->attr.name, "dir_level")) {

		if (t > MAX_DIR_HASH_DEPTH)

			return -EINVAL;

		sbi->dir_level = t;

		return count;

	}



	*ui = (unsigned int)t;



	return count;