[PATCH v1 2/9] landlock: Cosmetic fixes for filesystem management

Mickaël Salaün mic at digikod.net
Wed Nov 11 21:34:35 UTC 2020


Improve comments and make get_inode_object() more readable.  The kfree()
call is correct but we should mimimize as much as possible lock windows.

Cc: James Morris <jmorris at namei.org>
Cc: Jann Horn <jannh at google.com>
Cc: Serge E. Hallyn <serge at hallyn.com>
Signed-off-by: Mickaël Salaün <mic at digikod.net>
---
 security/landlock/fs.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index b67c821bb40b..33fc7ae17c7f 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -85,8 +85,8 @@ static struct landlock_object *get_inode_object(struct inode *const inode)
 			return object;
 		}
 		/*
-		 * We're racing with release_inode(), the object is going away.
-		 * Wait for release_inode(), then retry.
+		 * We are racing with release_inode(), the object is going
+		 * away.  Wait for release_inode(), then retry.
 		 */
 		spin_lock(&object->lock);
 		spin_unlock(&object->lock);
@@ -107,21 +107,21 @@ static struct landlock_object *get_inode_object(struct inode *const inode)
 			lockdep_is_held(&inode->i_lock));
 	if (unlikely(object)) {
 		/* Someone else just created the object, bail out and retry. */
-		kfree(new_object);
 		spin_unlock(&inode->i_lock);
+		kfree(new_object);
 
 		rcu_read_lock();
 		goto retry;
-	} else {
-		rcu_assign_pointer(inode_sec->object, new_object);
-		/*
-		 * @inode will be released by hook_sb_delete() on its
-		 * superblock shutdown.
-		 */
-		ihold(inode);
-		spin_unlock(&inode->i_lock);
-		return new_object;
 	}
+
+	rcu_assign_pointer(inode_sec->object, new_object);
+	/*
+	 * @inode will be released by hook_sb_delete() on its superblock
+	 * shutdown.
+	 */
+	ihold(inode);
+	spin_unlock(&inode->i_lock);
+	return new_object;
 }
 
 /* All access rights which can be tied to files. */
-- 
2.29.2



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