ceph: Do not do invalidate if the filesystem is mounted nofsc

Previously we would always try to enqueue work even if the filesystem is not
mounted with fscache enabled (or the file has no cookie). In the case of the
filesystem mouned nofsc (but with fscache compiled in) this would lead to a
crash.

Signed-off-by: Milosz Tanski <milosz@adfin.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
index c737ae9893ef..d3b88c7518d0 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -374,8 +374,12 @@ out:
 
 void ceph_queue_revalidate(struct inode *inode)
 {
+        struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
         struct ceph_inode_info *ci = ceph_inode(inode);
 
+        if (fsc->revalidate_wq == NULL || ci->fscache == NULL)
+                return;
+
         ihold(inode);
 
         if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq,