linux-ext4 - [PATCH 22/50] fs: use inode_tryget in find

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Message-ID: <0fca9386c2eca65e7fa5a39faca34ebf42d71cd0.1755806649.git.josef@toxicpanda.com>
Date: Thu, 21 Aug 2025 16:18:33 -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 22/50] fs: use inode_tryget in find_inode*

Now that we never drop the i_count to 0 for valid objects, rework the
logic in the find_inode* helpers to use inode_tryget() to see if they
have a live inode.  If this fails we can wait for the inode to be freed
as we know it's currently being evicted.

Signed-off-by: Josef Bacik <josef@...icpanda.com>
---
 fs/inode.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index b9122c1eee1d..893ac902268b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1109,6 +1109,7 @@ long prune_icache_sb(struct super_block *sb, struct shrink_control *sc)
 }
 
 static void __wait_on_freeing_inode(struct inode *inode, bool is_inode_hash_locked);
+
 /*
  * Called with the inode lock held.
  */
@@ -1132,16 +1133,15 @@ static struct inode *find_inode(struct super_block *sb,
 		if (!test(inode, data))
 			continue;
 		spin_lock(&inode->i_lock);
-		if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
-			__wait_on_freeing_inode(inode, is_inode_hash_locked);
-			goto repeat;
-		}
 		if (unlikely(inode->i_state & I_CREATING)) {
 			spin_unlock(&inode->i_lock);
 			rcu_read_unlock();
 			return ERR_PTR(-ESTALE);
 		}
-		__iget(inode);
+		if (!inode_tryget(inode)) {
+			__wait_on_freeing_inode(inode, is_inode_hash_locked);
+			goto repeat;
+		}
 		inode_lru_list_del(inode);
 		spin_unlock(&inode->i_lock);
 		rcu_read_unlock();
@@ -1174,16 +1174,15 @@ static struct inode *find_inode_fast(struct super_block *sb,
 		if (inode->i_sb != sb)
 			continue;
 		spin_lock(&inode->i_lock);
-		if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
-			__wait_on_freeing_inode(inode, is_inode_hash_locked);
-			goto repeat;
-		}
 		if (unlikely(inode->i_state & I_CREATING)) {
 			spin_unlock(&inode->i_lock);
 			rcu_read_unlock();
 			return ERR_PTR(-ESTALE);
 		}
-		__iget(inode);
+		if (!inode_tryget(inode)) {
+			__wait_on_freeing_inode(inode, is_inode_hash_locked);
+			goto repeat;
+		}
 		inode_lru_list_del(inode);
 		spin_unlock(&inode->i_lock);
 		rcu_read_unlock();
-- 
2.49.0