xfs: fix I_DONTCACHE

Yup, the VFS hoist broke it, and nobody noticed. Bulkstat workloads
make it clear that it doesn't work as it should.

Fixes: dae2f8ed ("fs: Lift XFS_IDONTCACHE to the VFS layer")
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

fs/xfs/xfs_icache.c

@@ -84,8 +84,9 @@ xfs_inode_alloc(
 		return NULL;
 	}
 
-	/* VFS doesn't initialise i_mode! */
+	/* VFS doesn't initialise i_mode or i_state! */
 	VFS_I(ip)->i_mode = 0;
+	VFS_I(ip)->i_state = 0;
 
 	XFS_STATS_INC(mp, vn_active);
 	ASSERT(atomic_read(&ip->i_pincount) == 0);

fs/xfs/xfs_iops.c

@@ -1344,7 +1344,7 @@ xfs_setup_inode(
 	gfp_t			gfp_mask;
 
 	inode->i_ino = ip->i_ino;
-	inode->i_state = I_NEW;
+	inode->i_state |= I_NEW;
 
 	inode_sb_list_add(inode);
 	/* make the inode look hashed for the writeback code */