ceph: fix open for write on clustered mds

Normally when we open a file we already have a cap, and simply update the
wanted set.  However, if we open a file for write, but don't have an auth
cap, that doesn't work; we need to open a new cap with the auth MDS.  Only
reuse existing caps if we are opening for read or the existing cap is auth.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index e77c28cf3690..87ee944724f8 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -154,11 +154,13 @@ int ceph_open(struct inode *inode, struct file *file)
         }
 
         /*
-         * No need to block if we have any caps.  Update wanted set
+         * No need to block if we have caps on the auth MDS (for
+         * write) or any MDS (for read).  Update wanted set
          * asynchronously.
          */
         spin_lock(&inode->i_lock);
-        if (__ceph_is_any_real_caps(ci)) {
+        if (__ceph_is_any_real_caps(ci) &&
+            (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
                 int mds_wanted = __ceph_caps_mds_wanted(ci);
                 int issued = __ceph_caps_issued(ci, NULL);