linux-ext4 - [PATCH 46/50] fs: remove some spurious I

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Message-ID: <de518c3d59fcbb619c78a6a33da5a8a872118813.1755806649.git.josef@toxicpanda.com>
Date: Thu, 21 Aug 2025 16:18:57 -0400
From: Josef Bacik <josef@...icpanda.com>
To: linux-fsdevel@...r.kernel.org,
	linux-btrfs@...r.kernel.org,
	kernel-team@...com,
	linux-ext4@...r.kernel.org,
	linux-xfs@...r.kernel.org,
	brauner@...nel.org,
	viro@...IV.linux.org.uk
Subject: [PATCH 46/50] fs: remove some spurious I_FREEING references in inode.c

Now that we have the i_count reference count rules set so that we only
go into these evict paths with a 0 count, update the sanity checks to
check that instead of I_FREEING.

Signed-off-by: Josef Bacik <josef@...icpanda.com>
---
 fs/inode.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index 4e1eeb0c3889..f715504778d2 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -874,7 +874,7 @@ void clear_inode(struct inode *inode)
 	 */
 	xa_unlock_irq(&inode->i_data.i_pages);
 	BUG_ON(!list_empty(&inode->i_data.i_private_list));
-	BUG_ON(!(inode->i_state & I_FREEING));
+	BUG_ON(refcount_read(&inode->i_count) != 0);
 	BUG_ON(inode->i_state & I_CLEAR);
 	BUG_ON(!list_empty(&inode->i_wb_list));
 	/* don't need i_lock here, no concurrent mods to i_state */
@@ -887,19 +887,19 @@ EXPORT_SYMBOL(clear_inode);
  * to. We remove any pages still attached to the inode and wait for any IO that
  * is still in progress before finally destroying the inode.
  *
- * An inode must already be marked I_FREEING so that we avoid the inode being
+ * An inode must already have an i_count of 0 so that we avoid the inode being
  * moved back onto lists if we race with other code that manipulates the lists
  * (e.g. writeback_single_inode). The caller is responsible for setting this.
  *
  * An inode must already be removed from the LRU list before being evicted from
- * the cache. This should occur atomically with setting the I_FREEING state
- * flag, so no inodes here should ever be on the LRU when being evicted.
+ * the cache. This should always be the case as the LRU list holds an i_count
+ * reference on the inode, and we only evict inodes with an i_count of 0.
  */
 static void evict(struct inode *inode)
 {
 	const struct super_operations *op = inode->i_sb->s_op;
 
-	BUG_ON(!(inode->i_state & I_FREEING));
+	BUG_ON(refcount_read(&inode->i_count) != 0);
 	BUG_ON(!list_empty(&inode->i_lru));
 
 	if (!list_empty(&inode->i_io_list))
@@ -913,8 +913,8 @@ static void evict(struct inode *inode)
 	/*
 	 * Wait for flusher thread to be done with the inode so that filesystem
 	 * does not start destroying it while writeback is still running. Since
-	 * the inode has I_FREEING set, flusher thread won't start new work on
-	 * the inode.  We just have to wait for running writeback to finish.
+	 * the inode has a 0 i_count, flusher thread won't start new work on the
+	 * inode.  We just have to wait for running writeback to finish.
 	 */
 	inode_wait_for_writeback(inode);
 	spin_unlock(&inode->i_lock);
-- 
2.49.0