ceph: use I_COMPLETE inode flag instead of D_COMPLETE flag

commit c6ffe10015 moved the flag that tracks if the dcache contents
for a directory are complete to dentry. The problem is there are
lots of places that use ceph_dir_{set,clear,test}_complete() while
holding i_ceph_lock. but ceph_dir_{set,clear,test}_complete() may
sleep because they call dput().

This patch basically reverts that commit. For ceph_d_prune(), it's
called with both the dentry to prune and the parent dentry are
locked. So it's safe to access the parent dentry's d_inode and
clear I_COMPLETE flag.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 86810b6..20dd1ee 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -204,7 +204,6 @@
  * Ceph dentry state
  */
 struct ceph_dentry_info {
-	unsigned long flags;
 	struct ceph_mds_session *lease_session;
 	u32 lease_gen, lease_shared_gen;
 	u32 lease_seq;
@@ -215,18 +214,6 @@
 	u64 offset;
 };
 
-/*
- * dentry flags
- *
- * The locking for D_COMPLETE is a bit odd:
- *  - we can clear it at almost any time (see ceph_d_prune)
- *  - it is only meaningful if:
- *    - we hold dir inode i_ceph_lock
- *    - we hold dir FILE_SHARED caps
- *    - the dentry D_COMPLETE is set
- */
-#define CEPH_D_COMPLETE 1  /* if set, d_u.d_subdirs is complete directory */
-
 struct ceph_inode_xattrs_info {
 	/*
 	 * (still encoded) xattr blob. we avoid the overhead of parsing
@@ -267,7 +254,7 @@
 	struct timespec i_rctime;
 	u64 i_rbytes, i_rfiles, i_rsubdirs;
 	u64 i_files, i_subdirs;
-	u64 i_max_offset;  /* largest readdir offset, set with D_COMPLETE */
+	u64 i_max_offset;  /* largest readdir offset, set with I_COMPLETE */
 
 	struct rb_root i_fragtree;
 	struct mutex i_fragtree_mutex;
@@ -432,6 +419,7 @@
 /*
  * Ceph inode.
  */
+#define CEPH_I_COMPLETE  1  /* we have complete directory cached */
 #define CEPH_I_NODELAY   4  /* do not delay cap release */
 #define CEPH_I_FLUSH     8  /* do not delay flush of dirty metadata */
 #define CEPH_I_NOFLUSH  16  /* do not flush dirty caps */
@@ -489,13 +477,6 @@
 }
 
 /*
- * set/clear directory D_COMPLETE flag
- */
-void ceph_dir_set_complete(struct inode *inode);
-void ceph_dir_clear_complete(struct inode *inode);
-bool ceph_dir_test_complete(struct inode *inode);
-
-/*
  * caps helpers
  */
 static inline bool __ceph_is_any_real_caps(struct ceph_inode_info *ci)