ceph: avoid updating mds_wanted too frequently

user space may open/close single file frequently. It's not good
to send a clientcaps message to mds for each open/close syscall.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index e3a2a3f32568..d941c48e8bff 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1184,6 +1184,13 @@ static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
                 delayed = 1;
         }
         ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
+        if (want & ~cap->mds_wanted) {
+                /* user space may open/close single file frequently.
+                 * This avoids droping mds_wanted immediately after
+                 * requesting new mds_wanted.
+                 */
+                __cap_set_timeouts(mdsc, ci);
+        }
 
         cap->issued &= retain;  /* drop bits we don't want */
         if (cap->implemented & ~cap->issued) {
@@ -2485,15 +2492,14 @@ again:
                                 goto out_unlock;
                         }
                         mds_wanted = __ceph_caps_mds_wanted(ci);
-                        if ((mds_wanted & need) != need) {
+                        if (need & ~(mds_wanted & need)) {
                                 dout("get_cap_refs %p caps were dropped"
                                      " (session killed?)\n", inode);
                                 *err = -ESTALE;
                                 ret = 1;
                                 goto out_unlock;
                         }
-                        if ((mds_wanted & file_wanted) ==
-                            (file_wanted & (CEPH_CAP_FILE_RD|CEPH_CAP_FILE_WR)))
+                        if (!(file_wanted & ~mds_wanted))
                                 ci->i_ceph_flags &= ~CEPH_I_CAP_DROPPED;
                 }