ceph: fix cache revoke race

handle following sequence of events:

- non-auth MDS revokes Fc cap. queue invalidate work
- auth MDS issues Fc cap through request reply. i_rdcache_gen gets
  increased.
- invalidate work runs. it finds i_rdcache_revoking != i_rdcache_gen,
  so it does nothing.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

3 files changed, 8 insertions, 4 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 2c39d9fe18d7..d2154d63f671 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -816,7 +816,7 @@ int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
 
         for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
                 cap = rb_entry(p, struct ceph_cap, ci_node);
-                if (cap != ocap && __cap_is_valid(cap) &&
+                if (cap != ocap &&
                     (cap->implemented & ~cap->issued & mask))
                         return 1;
         }
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index a808bfb8d8d8..3db97ba15a06 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1466,7 +1466,8 @@ static void ceph_invalidate_work(struct work_struct *work)
         dout("invalidate_pages %p gen %d revoking %d\n", inode,
              ci->i_rdcache_gen, ci->i_rdcache_revoking);
         if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
-                /* nevermind! */
+                if (__ceph_caps_revoking_other(ci, NULL, CEPH_CAP_FILE_CACHE))
+                        check = 1;
                 spin_unlock(&ci->i_ceph_lock);
                 mutex_unlock(&ci->i_truncate_mutex);
                 goto out;
@@ -1487,13 +1488,14 @@ static void ceph_invalidate_work(struct work_struct *work)
                 dout("invalidate_pages %p gen %d raced, now %d revoking %d\n",
                      inode, orig_gen, ci->i_rdcache_gen,
                      ci->i_rdcache_revoking);
+                if (__ceph_caps_revoking_other(ci, NULL, CEPH_CAP_FILE_CACHE))
+                        check = 1;
         }
         spin_unlock(&ci->i_ceph_lock);
         mutex_unlock(&ci->i_truncate_mutex);
-
+out:
         if (check)
                 ceph_check_caps(ci, 0, NULL);
-out:
         iput(inode);
 }
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 7fa78a7c8894..891cda8c72aa 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -528,6 +528,8 @@ static inline int __ceph_caps_dirty(struct ceph_inode_info *ci)
 }
 extern int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
 
+extern int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
+                                      struct ceph_cap *ocap, int mask);
 extern int ceph_caps_revoking(struct ceph_inode_info *ci, int mask);
 extern int __ceph_caps_used(struct ceph_inode_info *ci);