vfs: renumber DCACHE_xyz flags, remove some stale ones

Gcc tends to generate better code with small integers, including the
DCACHE_xyz flag tests - so move the common ones to be first in the list.
Also just remove the unused DCACHE_INOTIFY_PARENT_WATCHED and
DCACHE_AUTOFS_PENDING values, their users no longer exists in the source
tree.

And add a "unlikely()" to the DCACHE_OP_COMPARE test, since we want the
common case to be a nice straight-line fall-through.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/dcache.c

@@ -1729,7 +1729,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
 		 */
 		if (read_seqcount_retry(&dentry->d_seq, *seq))
 			goto seqretry;
-		if (parent->d_flags & DCACHE_OP_COMPARE) {
+		if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {
 			if (parent->d_op->d_compare(parent, *inode,
 						dentry, i,
 						tlen, tname, name))

include/linux/dcache.h

@@ -180,12 +180,12 @@ struct dentry_operations {
  */
 
 /* d_flags entries */
-#define DCACHE_AUTOFS_PENDING 0x0001    /* autofs: "under construction" */
-#define DCACHE_NFSFS_RENAMED  0x0002
-     /* this dentry has been "silly renamed" and has to be deleted on the last
-      * dput() */
+#define DCACHE_OP_HASH		0x0001
+#define DCACHE_OP_COMPARE	0x0002
+#define DCACHE_OP_REVALIDATE	0x0004
+#define DCACHE_OP_DELETE	0x0008
 
-#define	DCACHE_DISCONNECTED	0x0004
+#define	DCACHE_DISCONNECTED	0x0010
      /* This dentry is possibly not currently connected to the dcache tree, in
       * which case its parent will either be itself, or will have this flag as
       * well.  nfsd will not use a dentry with this bit set, but will first
@@ -196,22 +196,18 @@ struct dentry_operations {
       * dentry into place and return that dentry rather than the passed one,
       * typically using d_splice_alias. */
 
-#define DCACHE_REFERENCED	0x0008  /* Recently used, don't discard. */
-#define DCACHE_RCUACCESS	0x0010	/* Entry has ever been RCU-visible */
-#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020
-     /* Parent inode is watched by inotify */
-
-#define DCACHE_COOKIE		0x0040	/* For use by dcookie subsystem */
-#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080
-     /* Parent inode is watched by some fsnotify listener */
+#define DCACHE_REFERENCED	0x0020  /* Recently used, don't discard. */
+#define DCACHE_RCUACCESS	0x0040	/* Entry has ever been RCU-visible */
 
 #define DCACHE_CANT_MOUNT	0x0100
 #define DCACHE_GENOCIDE		0x0200
 
-#define DCACHE_OP_HASH		0x1000
-#define DCACHE_OP_COMPARE	0x2000
-#define DCACHE_OP_REVALIDATE	0x4000
-#define DCACHE_OP_DELETE	0x8000
+#define DCACHE_NFSFS_RENAMED	0x1000
+     /* this dentry has been "silly renamed" and has to be deleted on the last
+      * dput() */
+#define DCACHE_COOKIE		0x2000	/* For use by dcookie subsystem */
+#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x4000
+     /* Parent inode is watched by some fsnotify listener */
 
 #define DCACHE_MOUNTED		0x10000	/* is a mountpoint */
 #define DCACHE_NEED_AUTOMOUNT	0x20000	/* handle automount on this dir */