Re: [PATCH v2 0/5] nfsd: don't allow concurrent queueing of workqueue jobs

[cel]

From: Chuck Lever <chuck.lever@xxxxxxxxxx>

On Thu, 20 Feb 2025 11:47:12 -0500, Jeff Layton wrote:
> While looking at the problem that Li Lingfeng reported [1] around
> callback queueing failures, I noticed that there were potential
> scenarios where the callback workqueue jobs could run concurrently with
> an rpc_task. Since they touch some of the same fields, this is incorrect
> at best and potentially dangerous.
> 
> This patchset adds a new mechanism for ensuring that the same
> nfsd4_callback can't run concurrently with itself, regardless of where
> it is in its execution. This also gives us a more sure mechanism for
> handling the places where we need to take and hold a reference on an
> object while the callback is running.
> 
> [...]

Applied to nfsd-testing, thanks! This series replaces:

https://lore.kernel.org/linux-nfs/20250218135423.1487309-1-lilingfeng3@xxxxxxxxxx/

Review is still open.

[1/5] nfsd: prevent callback tasks running concurrently
      commit: 9a03a9d82410bdb758a6b342689e0c235bba94f1
[2/5] nfsd: eliminate cl_ra_cblist and NFSD4_CLIENT_CB_RECALL_ANY
      commit: 743fda103062626c828dbac774716e718a74f81b
[3/5] nfsd: replace CB_GETATTR_BUSY with NFSD4_CALLBACK_RUNNING
      commit: d2d94554567f486eba111e953e75745eca09bee3
[4/5] nfsd: move cb_need_restart flag into cb_flags
      commit: 355f1ec5ce21ab324d9b3978d2d5abe6d0c84024
[5/5] nfsd: handle errors from rpc_call_async()
      commit: d0f1ba5ed270fbda06248ef8af822a9e14708ee1

--
Chuck Lever