diff options
| -rw-r--r-- | fs/inode.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/inode.c b/fs/inode.c index f356fe2ec2b6..05613745fad6 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -676,6 +676,16 @@ static void evict(struct inode *inode) remove_inode_hash(inode); + /* + * Wake up waiters in __wait_on_freeing_inode(). + * + * Lockless hash lookup may end up finding the inode before we removed + * it above, but only lock it *after* we are done with the wakeup below. + * In this case the potential waiter cannot safely block. + * + * The inode being unhashed after the call to remove_inode_hash() is + * used as an indicator whether blocking on it is safe. + */ spin_lock(&inode->i_lock); wake_up_bit(&inode->i_state, __I_NEW); BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); @@ -2291,6 +2301,16 @@ static void __wait_on_freeing_inode(struct inode *inode, bool locked) { wait_queue_head_t *wq; DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); + + /* + * Handle racing against evict(), see that routine for more details. + */ + if (unlikely(inode_unhashed(inode))) { + WARN_ON(locked); + spin_unlock(&inode->i_lock); + return; + } + wq = bit_waitqueue(&inode->i_state, __I_NEW); prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); spin_unlock(&inode->i_lock); |