linux-ext4 - [PATCH 40/50] landlock: remove I_FREEING|I_WILL

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Message-ID: <e54edfc39b9b19fe8ff8c4c7e8b5fe06caa78fc9.1755806649.git.josef@toxicpanda.com>
Date: Thu, 21 Aug 2025 16:18:51 -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 40/50] landlock: remove I_FREEING|I_WILL_FREE check

We have the reference count that we can use to see if the inode is
alive.

Signed-off-by: Josef Bacik <josef@...icpanda.com>
---
 security/landlock/fs.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 570f851dc469..fc7e577b56e1 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -1280,23 +1280,8 @@ static void hook_sb_delete(struct super_block *const sb)
 	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
 		struct landlock_object *object;
 
-		/* Only handles referenced inodes. */
-		if (!refcount_read(&inode->i_count))
-			continue;
-
-		/*
-		 * Protects against concurrent modification of inode (e.g.
-		 * from get_inode_object()).
-		 */
 		spin_lock(&inode->i_lock);
-		/*
-		 * Checks I_FREEING and I_WILL_FREE  to protect against a race
-		 * condition when release_inode() just called iput(), which
-		 * could lead to a NULL dereference of inode->security or a
-		 * second call to iput() for the same Landlock object.  Also
-		 * checks I_NEW because such inode cannot be tied to an object.
-		 */
-		if (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW)) {
+		if (inode->i_state & I_NEW) {
 			spin_unlock(&inode->i_lock);
 			continue;
 		}
@@ -1308,10 +1293,11 @@ static void hook_sb_delete(struct super_block *const sb)
 			spin_unlock(&inode->i_lock);
 			continue;
 		}
-		/* Keeps a reference to this inode until the next loop walk. */
-		__iget(inode);
 		spin_unlock(&inode->i_lock);
 
+		if (!igrab(inode))
+			continue;
+
 		/*
 		 * If there is no concurrent release_inode() ongoing, then we
 		 * are in charge of calling iput() on this inode, otherwise we
-- 
2.49.0