According to fs/afs/flock.c, the kernel may sleep under a spinlock,
and the function call paths are:
afs_do_setlk (acquire the spinlock: inode->i_lock)
afs_vnode_fetch_status
schedule --> may sleep
afs_do_setlk (acquire the spinlock: inode->i_lock)
wait_event_interruptible --> may sleep
These bugs may be introduced by only considering "vnode->lock" but
ignoring "inode->i_lock".
A possible fix is to unlock "inode->i_lock" before calling
afs_vnode_fetch_status and wait_event_interruptible, and lock
"inode->i_lock" again after them.
These bugs are found by my static analysis tool and my code review.
Thanks,
Jia-Ju Bai
