diff options
| author | NeilBrown <neilb@suse.de> | 2024-09-16 09:45:40 +1000 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2024-09-20 19:31:03 -0400 |
| commit | 3391fc92db8e761f1a2df5612fcb999dac6bc00a (patch) | |
| tree | 68d81667cf7cb6ce876f58b39a7cf4729f87cf38 /net | |
| parent | 59f3b138160d37435b353e95c62d9ebf7f80b117 (diff) | |
sunrpc: allow svc threads to fail initialisation cleanly
If an svc thread needs to perform some initialisation that might fail,
it has no good way to handle the failure.
Before the thread can exit it must call svc_exit_thread(), but that
requires the service mutex to be held. The thread cannot simply take
the mutex as that could deadlock if there is a concurrent attempt to
shut down all threads (which is unlikely, but not impossible).
nfsd currently call svc_exit_thread() unprotected in the unlikely event
that unshare_fs_struct() fails.
We can clean this up by introducing svc_thread_init_status() by which an
svc thread can report whether initialisation has succeeded. If it has,
it continues normally into the action loop. If it has not,
svc_thread_init_status() immediately aborts the thread.
svc_start_kthread() waits for either of these to happen, and calls
svc_exit_thread() (under the mutex) if the thread aborted.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/svc.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 17f0f59c068f..9aff845196ce 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -706,6 +706,8 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node)) goto out_enomem; + rqstp->rq_err = -EAGAIN; /* No error yet */ + serv->sv_nrthreads += 1; pool->sp_nrthreads += 1; @@ -792,6 +794,7 @@ svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) struct svc_pool *chosen_pool; unsigned int state = serv->sv_nrthreads-1; int node; + int err; do { nrservs--; @@ -814,6 +817,13 @@ svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) svc_sock_update_bufs(serv); wake_up_process(task); + + wait_var_event(&rqstp->rq_err, rqstp->rq_err != -EAGAIN); + err = rqstp->rq_err; + if (err) { + svc_exit_thread(rqstp); + return err; + } } while (nrservs > 0); return 0; |