nfsd: clear CALLBACK_RUNNING on failed delegation recall queue

nfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit
at entry to serialize recall work, then calls nfsd4_run_cb() to queue
the recall.  When the queue attempt fails the refcount bump is undone,
but the RUNNING bit is left set.  The only site that clears the bit is
nfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the
workqueue and is therefore unreachable when nothing was queued.

The bit becomes a permanent latch on dp->dl_recall.cb_flags: every
subsequent break_lease() on the same delegation hits the early-return
guard in nfsd_break_one_deleg() and silently skips the recall, so the
delegation is never broken and the conflicting open or lock stalls.

Fix by clearing NFSD4_CALLBACK_RUNNING on the !queued branch alongside
the refcount_dec.

Fixes: 1054e8ffc5c4 ("nfsd: prevent callback tasks running concurrently")
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260526-cb_recall_any_callback_running_stuck-v1-2-310011a028f3@kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

0 files changed, 0 insertions, 0 deletions