[PATCH 12/21] fat: Kill d_invalidate() in vfat_lookup()

[OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>]

d_invalidate() for positive dentry doesn't work in some cases
(vfsmount, nfsd, and maybe others). shrink_dcache_parent() by
d_invalidate() is pointless for vfat usage at all.

So, this kills it, and intead of it uses d_move().

To save old behavior, this returns alias simply for directory (don't
change pwd, etc..). the directory lookup shouldn't be important for
performance.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---

 fs/fat/namei_vfat.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff -puN fs/fat/namei_vfat.c~vfat-dcache-d_invalidate-fix fs/fat/namei_vfat.c
--- linux-2.6/fs/fat/namei_vfat.c~vfat-dcache-d_invalidate-fix	2008-08-27 19:18:24.000000000 +0900
+++ linux-2.6-hirofumi/fs/fat/namei_vfat.c	2008-08-27 19:18:24.000000000 +0900
@@ -745,13 +745,12 @@ static struct dentry *vfat_lookup(struct
 		 *
 		 * Switch to new one for reason of locality if possible.
 		 */
-		if (d_invalidate(alias) == 0)
-			dput(alias);
-		else {
-			iput(inode);
-			unlock_super(sb);
-			return alias;
-		}
+		BUG_ON(d_unhashed(alias));
+		if (!S_ISDIR(inode->i_mode))
+			d_move(alias, dentry);
+		iput(inode);
+		unlock_super(sb);
+		return alias;
 	}
 out:
 	unlock_super(sb);
_