[PATCH 1/8] lockd: lockd server-side shouldn't set fl_ops

J. Bruce Fields
2021-08-20T21:02:15Z

From: "J. Bruce Fields" <bfields@redhat.com>

Locks have two sets of op arrays, fl_lmops for the lock manager (lockd
or nfsd), fl_ops for the filesystem. The server-side lockd code has
been setting its own fl_ops, which leads to confusion (and crashes) in
the reexport case, where the filesystem expects to be the only one
setting fl_ops.

And there's no reason for it that I can see-the lm_get/put_owner ops do
the same job.

Reported-by: Daire Byrne <daire@dneg.com>
Tested-by: Daire Byrne <daire@dneg.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/lockd/svclock.c | 30 ++++++++++++------------------
1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 61d3cc2283dc..1781fc5e9091 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -395,28 +395,10 @@ nlmsvc_release_lockowner(struct nlm_lock *lock)
nlmsvc_put_lockowner(lock->fl.fl_owner);
}

-static void nlmsvc_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
-{
- struct nlm_lockowner *nlm_lo = (struct nlm_lockowner *)fl->fl_owner;
- new->fl_owner = nlmsvc_get_lockowner(nlm_lo);
-}
-
-static void nlmsvc_locks_release_private(struct file_lock *fl)
-{
- nlmsvc_put_lockowner((struct nlm_lockowner *)fl->fl_owner);
-}
-
-static const struct file_lock_operations nlmsvc_lock_ops = {
- .fl_copy_lock = nlmsvc_locks_copy_lock,
- .fl_release_private = nlmsvc_locks_release_private,
-};
-
void nlmsvc_locks_init_private(struct file_lock *fl, struct nlm_host *host,
pid_t pid)
{
fl->fl_owner = nlmsvc_find_lockowner(host, pid);
- if (fl->fl_owner != NULL)
- fl->fl_ops = &nlmsvc_lock_ops;
}

/*
@@ -788,9 +770,21 @@ nlmsvc_notify_blocked(struct file_lock *fl)
printk(KERN_WARNING "lockd: notification for unknown block!\n");
}

+static fl_owner_t nlmsvc_get_owner(fl_owner_t owner)
+{
+ return nlmsvc_get_lockowner(owner);
+}
+
+static void nlmsvc_put_owner(fl_owner_t owner)
+{
+ nlmsvc_put_lockowner(owner);
+}
+
const struct lock_manager_operations nlmsvc_lock_operations = {
.lm_notify = nlmsvc_notify_blocked,
.lm_grant = nlmsvc_grant_deferred,
+ .lm_get_owner = nlmsvc_get_owner,
+ .lm_put_owner = nlmsvc_put_owner,
};

/*
--
2.31.1