inode: port __I_NEW to var event

Port the __I_NEW mechanism to use the new var event mechanism.

Link: https://lore.kernel.org/r/20240823-work-i_state-v3-4-5cd5fd207a57@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 24 insertions, 8 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 1b0f52ebae27..1aa785421f13 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -734,7 +734,13 @@ static void evict(struct inode *inode)
 	 * used as an indicator whether blocking on it is safe.
 	 */
 	spin_lock(&inode->i_lock);
-	wake_up_bit(&inode->i_state, __I_NEW);
+	/*
+	 * Pairs with the barrier in prepare_to_wait_event() to make sure
+	 * ___wait_var_event() either sees the bit cleared or
+	 * waitqueue_active() check in wake_up_var() sees the waiter.
+	 */
+	smp_mb();
+	inode_wake_up_bit(inode, __I_NEW);
 	BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
 	spin_unlock(&inode->i_lock);
 
@@ -1146,8 +1152,13 @@ void unlock_new_inode(struct inode *inode)
 	spin_lock(&inode->i_lock);
 	WARN_ON(!(inode->i_state & I_NEW));
 	inode->i_state &= ~I_NEW & ~I_CREATING;
+	/*
+	 * Pairs with the barrier in prepare_to_wait_event() to make sure
+	 * ___wait_var_event() either sees the bit cleared or
+	 * waitqueue_active() check in wake_up_var() sees the waiter.
+	 */
 	smp_mb();
-	wake_up_bit(&inode->i_state, __I_NEW);
+	inode_wake_up_bit(inode, __I_NEW);
 	spin_unlock(&inode->i_lock);
 }
 EXPORT_SYMBOL(unlock_new_inode);
@@ -1158,8 +1169,13 @@ void discard_new_inode(struct inode *inode)
 	spin_lock(&inode->i_lock);
 	WARN_ON(!(inode->i_state & I_NEW));
 	inode->i_state &= ~I_NEW;
+	/*
+	 * Pairs with the barrier in prepare_to_wait_event() to make sure
+	 * ___wait_var_event() either sees the bit cleared or
+	 * waitqueue_active() check in wake_up_var() sees the waiter.
+	 */
 	smp_mb();
-	wake_up_bit(&inode->i_state, __I_NEW);
+	inode_wake_up_bit(inode, __I_NEW);
 	spin_unlock(&inode->i_lock);
 	iput(inode);
 }
@@ -2348,8 +2364,8 @@ EXPORT_SYMBOL(inode_needs_sync);
  */
 static void __wait_on_freeing_inode(struct inode *inode, bool is_inode_hash_locked)
 {
-	wait_queue_head_t *wq;
-	DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW);
+	struct wait_bit_queue_entry wqe;
+	struct wait_queue_head *wq_head;
 
 	/*
 	 * Handle racing against evict(), see that routine for more details.
@@ -2360,14 +2376,14 @@ static void __wait_on_freeing_inode(struct inode *inode, bool is_inode_hash_lock
 		return;
 	}
 
-	wq = bit_waitqueue(&inode->i_state, __I_NEW);
-	prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+	wq_head = inode_bit_waitqueue(&wqe, inode, __I_NEW);
+	prepare_to_wait_event(wq_head, &wqe.wq_entry, TASK_UNINTERRUPTIBLE);
 	spin_unlock(&inode->i_lock);
 	rcu_read_unlock();
 	if (is_inode_hash_locked)
 		spin_unlock(&inode_hash_lock);
 	schedule();
-	finish_wait(wq, &wait.wq_entry);
+	finish_wait(wq_head, &wqe.wq_entry);
 	if (is_inode_hash_locked)
 		spin_lock(&inode_hash_lock);
 	rcu_read_lock();