[PATCH AUTOSEL 4.19 363/671] afs: Fix double inc of vnode->cb_break

Sasha Levin
2020-01-16T17:07:45Z

From: David Howells <dhowells@redhat.com>

[ Upstream commit fd711586bb7d63f257da5eff234e68c446ac35ea ]

When __afs_break_callback() clears the CB_PROMISED flag, it increments
vnode->cb_break to trigger a future refetch of the status and callback -
however it also calls afs_clear_permits(), which also increments
vnode->cb_break.

Fix this by removing the increment from afs_clear_permits().

Whilst we're at it, fix the conditional call to afs_put_permits() as the
function checks to see if the argument is NULL, so the check is redundant.

Fixes: be080a6f43c4 ("afs: Overhaul permit caching");
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/afs/security.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/afs/security.c b/fs/afs/security.c
index 81dfedb7879f..66042b432baa 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -87,11 +87,9 @@ void afs_clear_permits(struct afs_vnode *vnode)
permits = rcu_dereference_protected(vnode->permit_cache,
lockdep_is_held(&vnode->lock));
RCU_INIT_POINTER(vnode->permit_cache, NULL);
- vnode->cb_break++;
spin_unlock(&vnode->lock);

- if (permits)
- afs_put_permits(permits);
+ afs_put_permits(permits);
}

/*
--
2.20.1