From: Al Viro <viro@zeniv.linux.org.uk>
To: Tejun Heo <tj@kernel.org>
Cc: Imran Khan <imran.f.khan@oracle.com>,
gregkh@linuxfoundation.org, ebiederm@xmission.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 01/10] kernfs: Remove reference counting for kernfs_open_node.
Date: Tue, 26 Apr 2022 20:13:22 +0000 [thread overview]
Message-ID: <YmhSYkXp0KBXOyFc@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <Ymg6AazfnwdZXkXx@slm.duckdns.org>
On Tue, Apr 26, 2022 at 08:29:21AM -1000, Tejun Heo wrote:
> The code is just wrong. You can end up:
>
> on = kn->attr.open;
> if (!on)
> return;
>
> // we get preempted here and someone else puts @on and then
> // recreates it
Can't happen - the caller has guaranteed that no new openers will be
coming. Look at the call chain of kernfs_drain_open_files()...
Al, back to life and staring at the pile of mail to sift through...
next prev parent reply other threads:[~2022-04-26 20:13 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-10 2:37 [PATCH v8 00/10] kernfs: Remove reference counting for kernfs_open_node Imran Khan
2022-04-10 2:37 ` [PATCH v8 01/10] " Imran Khan
2022-04-22 16:03 ` Tejun Heo
2022-04-26 1:43 ` Imran Khan
2022-04-26 18:29 ` Tejun Heo
2022-04-26 20:13 ` Al Viro [this message]
2022-04-26 20:16 ` Tejun Heo
2022-04-10 2:37 ` [PATCH v8 02/10] kernfs: make ->attr.open RCU protected Imran Khan
2022-04-22 16:19 ` Tejun Heo
2022-04-26 1:54 ` Imran Khan
2022-04-26 18:37 ` Tejun Heo
2022-04-10 2:37 ` [PATCH v8 03/10] kernfs: Change kernfs_notify_list to llist Imran Khan
2022-04-22 16:41 ` Tejun Heo
2022-04-10 2:37 ` [PATCH v8 04/10] kernfs: Introduce interface to access global kernfs_open_file_mutex Imran Khan
2022-04-10 2:37 ` [PATCH v8 05/10] kernfs: Replace global kernfs_open_file_mutex with hashed mutexes Imran Khan
2022-04-22 17:00 ` Tejun Heo
2022-04-10 2:37 ` [PATCH v8 06/10] kernfs: Use a per-fs rwsem to protect per-fs list of kernfs_super_info Imran Khan
2022-04-10 2:37 ` [PATCH v8 07/10] kernfs: Change kernfs_rename_lock into a read-write lock Imran Khan
2022-04-10 2:37 ` [PATCH v8 08/10] kernfs: Introduce interface to access per-fs rwsem Imran Khan
2022-04-10 2:37 ` [PATCH v8 09/10] kernfs: Replace per-fs rwsem with hashed rwsems Imran Khan
2022-04-10 2:37 ` [PATCH v8 10/10] kernfs: Add a document to describe hashed locks used in kernfs Imran Khan
2022-04-22 17:03 ` [PATCH v8 00/10] kernfs: Remove reference counting for kernfs_open_node Tejun Heo
2022-04-23 8:49 ` Imran Khan
2022-04-25 17:21 ` Tejun Heo
2022-04-28 17:28 ` Imran Khan
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