ceph: hold on to exclusive caps on complete directories

If a directory is complete, we want to keep the exclusive
cap. So that MDS does not end up revoking the shared cap
on every create/unlink operation.

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

1 files changed, 12 insertions, 0 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 37a42353b983..11631c4c7d14 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1561,7 +1561,19 @@ retry_locked:
         if (!mdsc->stopping && inode->i_nlink > 0) {
                 if (want) {
                         retain |= CEPH_CAP_ANY;       /* be greedy */
+                } else if (S_ISDIR(inode->i_mode) &&
+                           (issued & CEPH_CAP_FILE_SHARED) &&
+                            __ceph_dir_is_complete(ci)) {
+                        /*
+                         * If a directory is complete, we want to keep
+                         * the exclusive cap. So that MDS does not end up
+                         * revoking the shared cap on every create/unlink
+                         * operation.
+                         */
+                        want = CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_EXCL;
+                        retain |= want;
                 } else {
+
                         retain |= CEPH_CAP_ANY_SHARED;
                         /*
                          * keep RD only if we didn't have the file open RW,