[PATCH 0/2] jfs: add checks read-only to prevent NULL pointer deref

[Vasiliy Kovalev]

These two patches add read-only checks in JFS functions to
prevent attempts to modify a read-only filesystem, which could
lead to NULL pointer dereferencing. 

Reported-by: syzbot+4e89b5368baba8324e07@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=4e89b5368baba8324e07

[PATCH 1/2] jfs: add check read-only before txBeginAnon() call
[PATCH 2/2] jfs: add check read-only before truncation in jfs_truncate_nolock()