[PATCH 1/2] xfs: cleanup xfs_iunpin_wait/xfs_iunpin_nowait

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

Remove the inode item pointer and ili_last_lsn checks in __xfs_iunpin_wait
as any pinned inode is guaranteed to have them valid.  After this the
xfs_iunpin_nowait case is nothing more than a xfs_log_force_lsn, as we
know that the caller has already checked the pincount.

Make xfs_iunpin_nowait the new low-level routine just doing the log force
and rewrite xfs_iunpin_wait around it.


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

Index: xfs/fs/xfs/xfs_inode.c
===================================================================
--- xfs.orig/fs/xfs/xfs_inode.c 2010-02-17 10:47:39.141254207 +0100
+++ xfs/fs/xfs/xfs_inode.c      2010-02-17 10:55:24.505255043 +0100
@@ -2467,47 +2467,31 @@ xfs_iunpin(
 }
 
 /*
- * This is called to unpin an inode. It can be directed to wait or to return
- * immediately without waiting for the inode to be unpinned.  The caller must
- * have the inode locked in at least shared mode so that the buffer cannot be
- * subsequently pinned once someone is waiting for it to be unpinned.
+ * This is called to unpin an inode.  The caller must have the inode locked
+ * in at least shared mode so that the buffer cannot be subsequently pinned
+ * once someone is waiting for it to be unpinned.
  */
-STATIC void
-__xfs_iunpin_wait(
-       xfs_inode_t     *ip,
-       int             wait)
+static void
+xfs_iunpin_nowait(
+       struct xfs_inode        *ip)
 {
-       xfs_inode_log_item_t    *iip = ip->i_itemp;
-
        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
-       if (atomic_read(&ip->i_pincount) == 0)
-               return;
 
        /* Give the log a push to start the unpinning I/O */
-       if (iip && iip->ili_last_lsn)
-               xfs_log_force_lsn(ip->i_mount, iip->ili_last_lsn, 0);
-       else
-               xfs_log_force(ip->i_mount, 0);
+       xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0);
 
-       if (wait)
-               wait_event(ip->i_ipin_wait, (atomic_read(&ip->i_pincount) == 
0));
 }
 
 void
 xfs_iunpin_wait(
-       xfs_inode_t     *ip)
+       struct xfs_inode        *ip)
 {
-       __xfs_iunpin_wait(ip, 1);
-}
-
-static inline void
-xfs_iunpin_nowait(
-       xfs_inode_t     *ip)
-{
-       __xfs_iunpin_wait(ip, 0);
+       if (xfs_ipincount(ip)) {
+               xfs_iunpin_nowait(ip);
+               wait_event(ip->i_ipin_wait, (xfs_ipincount(ip) == 0));
+       }
 }
 
-
 /*
  * xfs_iextents_copy()
  *