[PATCH] remove v_number

[Christoph Hellwig <hch@xxxxxx>]

v_number is unused except for the naming some locks (which is a
functionality totally unused by Linux), so remove it and assorted
crap.  Besides saving two words in struct vnode this also gets rid
of a spinlock per inode allocation.


Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Index: linux-2.6/fs/xfs/linux-2.6/xfs_vnode.c
===================================================================
--- linux-2.6.orig/fs/xfs/linux-2.6/xfs_vnode.c 2006-11-29 16:37:23.000000000 
+0100
+++ linux-2.6/fs/xfs/linux-2.6/xfs_vnode.c      2006-11-29 16:38:09.000000000 
+0100
@@ -17,8 +17,6 @@
  */
 #include "xfs.h"
 
-uint64_t vn_generation;                /* vnode generation number */
-DEFINE_SPINLOCK(vnumber_lock);
 
 /*
  * Dedicated vnode inactive/reclaim sync semaphores.
@@ -82,12 +80,6 @@
        vp->v_flag = VMODIFIED;
        spinlock_init(&vp->v_lock, "v_lock");
 
-       spin_lock(&vnumber_lock);
-       if (!++vn_generation)   /* v_number shouldn't be zero */
-               vn_generation++;
-       vp->v_number = vn_generation;
-       spin_unlock(&vnumber_lock);
-
        ASSERT(VN_CACHED(vp) == 0);
 
        /* Initialize the first behavior and the behavior chain head. */
Index: linux-2.6/fs/xfs/linux-2.6/xfs_vnode.h
===================================================================
--- linux-2.6.orig/fs/xfs/linux-2.6/xfs_vnode.h 2006-11-29 16:38:13.000000000 
+0100
+++ linux-2.6/fs/xfs/linux-2.6/xfs_vnode.h      2006-11-29 16:39:08.000000000 
+0100
@@ -41,7 +41,6 @@
 typedef struct bhv_vnode {
        bhv_vflags_t    v_flag;                 /* vnode flags (see above) */
        bhv_vfs_t       *v_vfsp;                /* ptr to containing VFS */
-       bhv_vnumber_t   v_number;               /* in-core vnode number */
        bhv_head_t      v_bh;                   /* behavior head */
        spinlock_t      v_lock;                 /* VN_LOCK/VN_UNLOCK */
        atomic_t        v_iocount;              /* outstanding I/O count */
Index: linux-2.6/fs/xfs/xfs_iget.c
===================================================================
--- linux-2.6.orig/fs/xfs/xfs_iget.c    2006-11-29 16:36:19.000000000 +0100
+++ linux-2.6/fs/xfs/xfs_iget.c 2006-11-29 16:37:14.000000000 +0100
@@ -570,8 +570,8 @@
        bhv_vnode_t     *vp)
 {
        mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER,
-                    "xfsino", (long)vp->v_number);
-       mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", vp->v_number);
+                    "xfsino", ip->i_ino);
+       mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
        init_waitqueue_head(&ip->i_ipin_wait);
        atomic_set(&ip->i_pincount, 0);
        initnsema(&ip->i_flock, 1, "xfsfino");