ceph: flush dirty caps of unlinked inode ASAP

Client should release unlinked inode from its cache ASAP. But client
can't release inode with dirty caps.

Link: http://tracker.ceph.com/issues/22886
Signed-off-by: Zhi Zhang <zhang.david2011@gmail.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 6582c4507e6c..0e5bd3e3344e 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3965,6 +3965,32 @@ void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
 }
 
 /*
+ * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps. If it
+ * looks like the link count will hit 0, drop any other caps (other
+ * than PIN) we don't specifically want (due to the file still being
+ * open).
+ */
+int ceph_drop_caps_for_unlink(struct inode *inode)
+{
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
+
+        spin_lock(&ci->i_ceph_lock);
+        if (inode->i_nlink == 1) {
+                drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
+
+                ci->i_ceph_flags |= CEPH_I_NODELAY;
+                if (__ceph_caps_dirty(ci)) {
+                        struct ceph_mds_client *mdsc =
+                                ceph_inode_to_client(inode)->mdsc;
+                        __cap_delay_requeue_front(mdsc, ci);
+                }
+        }
+        spin_unlock(&ci->i_ceph_lock);
+        return drop;
+}
+
+/*
  * Helpers for embedding cap and dentry lease releases into mds
  * requests.
  *