queue-5.15/nfsd-make-nfsd4_run_cb-a-bool-return-function.patch

   1 From 0c5c5bf6b39c5fededcbc2d66e072bb6d5e58bc5 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Mon, 26 Sep 2022 14:41:01 -0400
   4 Subject: nfsd: make nfsd4_run_cb a bool return function
   5
   6 From: Jeff Layton <jlayton@kernel.org>
   7
   8 [ Upstream commit b95239ca4954a0d48b19c09ce7e8f31b453b4216 ]
   9
  10 queue_work can return false and not queue anything, if the work is
  11 already queued. If that happens in the case of a CB_RECALL, we'll have
  12 taken an extra reference to the stid that will never be put. Ensure we
  13 throw a warning in that case.
  14
  15 Signed-off-by: Jeff Layton <jlayton@kernel.org>
  16 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
  17 ---
  18  fs/nfsd/nfs4callback.c | 14 ++++++++++++--
  19  fs/nfsd/nfs4state.c    |  5 ++---
  20  fs/nfsd/state.h        |  2 +-
  21  3 files changed, 15 insertions(+), 6 deletions(-)
  22
  23 diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
  24 index face8908a40b1..39989c14c8a1e 100644
  25 --- a/fs/nfsd/nfs4callback.c
  26 +++ b/fs/nfsd/nfs4callback.c
  27 @@ -1373,11 +1373,21 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
  28         cb->cb_holds_slot = false;
  29  }
  30
  31 -void nfsd4_run_cb(struct nfsd4_callback *cb)
  32 +/**
  33 + * nfsd4_run_cb - queue up a callback job to run
  34 + * @cb: callback to queue
  35 + *
  36 + * Kick off a callback to do its thing. Returns false if it was already
  37 + * on a queue, true otherwise.
  38 + */
  39 +bool nfsd4_run_cb(struct nfsd4_callback *cb)
  40  {
  41         struct nfs4_client *clp = cb->cb_clp;
  42 +       bool queued;
  43
  44         nfsd41_cb_inflight_begin(clp);
  45 -       if (!nfsd4_queue_cb(cb))
  46 +       queued = nfsd4_queue_cb(cb);
  47 +       if (!queued)
  48                 nfsd41_cb_inflight_end(clp);
  49 +       return queued;
  50  }
  51 diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
  52 index e98306c69f424..61978ad43a0f7 100644
  53 --- a/fs/nfsd/nfs4state.c
  54 +++ b/fs/nfsd/nfs4state.c
  55 @@ -4874,14 +4874,13 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
  56          * we know it's safe to take a reference.
  57          */
  58         refcount_inc(&dp->dl_stid.sc_count);
  59 -       nfsd4_run_cb(&dp->dl_recall);
  60 +       WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall));
  61  }
  62
  63  /* Called from break_lease() with flc_lock held. */
  64  static bool
  65  nfsd_break_deleg_cb(struct file_lock *fl)
  66  {
  67 -       bool ret = false;
  68         struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;
  69         struct nfs4_file *fp = dp->dl_stid.sc_file;
  70         struct nfs4_client *clp = dp->dl_stid.sc_client;
  71 @@ -4907,7 +4906,7 @@ nfsd_break_deleg_cb(struct file_lock *fl)
  72         fp->fi_had_conflict = true;
  73         nfsd_break_one_deleg(dp);
  74         spin_unlock(&fp->fi_lock);
  75 -       return ret;
  76 +       return false;
  77  }
  78
  79  /**
  80 diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
  81 index b3477087a9fc3..e2daef3cc0034 100644
  82 --- a/fs/nfsd/state.h
  83 +++ b/fs/nfsd/state.h
  84 @@ -692,7 +692,7 @@ extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
  85  extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
  86  extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
  87                 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op);
  88 -extern void nfsd4_run_cb(struct nfsd4_callback *cb);
  89 +extern bool nfsd4_run_cb(struct nfsd4_callback *cb);
  90  extern int nfsd4_create_callback_queue(void);
  91  extern void nfsd4_destroy_callback_queue(void);
  92  extern void nfsd4_shutdown_callback(struct nfs4_client *);
  93 --
  94 2.43.0
  95