xfs: split out symlink code into it's own file.

The symlink code is about to get more complicated when CRCs are
added for remote symlink blocks. The symlink management code is
mostly self contained, so move it to it's own files so that all the
new code and the existing symlink code will not be intermingled
with other unrelated code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/Makefile

@@ -45,11 +45,11 @@ xfs-y				+= xfs_aops.o \
 				   xfs_itable.o \
 				   xfs_message.o \
 				   xfs_mru_cache.o \
-				   xfs_super.o \
-				   xfs_xattr.o \
 				   xfs_rename.o \
+				   xfs_super.o \
 				   xfs_utils.o \
 				   xfs_vnodeops.o \
+				   xfs_xattr.o \
 				   kmem.o \
 				   uuid.o
 
@@ -73,6 +73,7 @@ xfs-y				+= xfs_alloc.o \
 				   xfs_inode.o \
 				   xfs_log_recover.o \
 				   xfs_mount.o \
+				   xfs_symlink.o \
 				   xfs_trans.o
 
 # low-level transaction/log code

fs/xfs/xfs_bmap.c

@@ -47,6 +47,7 @@
 #include "xfs_filestream.h"
 #include "xfs_vnodeops.h"
 #include "xfs_trace.h"
+#include "xfs_symlink.h"
 
 
 kmem_zone_t		*xfs_bmap_free_item_zone;
@@ -1321,9 +1322,10 @@ xfs_bmap_add_attrfork_extents(
 }
 
 /*
- * Block initialisation functions for local to extent format conversion.
- * As these get more complex, they will be moved to the relevant files,
- * but for now they are too simple to worry about.
+ * Block initialisation function for local to extent format conversion.
+ *
+ * This shouldn't actually be called by anyone, so make sure debug kernels cause
+ * a noticable failure.
  */
 STATIC void
 xfs_bmap_local_to_extents_init_fn(
@@ -1332,23 +1334,12 @@ xfs_bmap_local_to_extents_init_fn(
 	struct xfs_inode	*ip,
 	struct xfs_ifork	*ifp)
 {
+	ASSERT(0);
 	bp->b_ops = &xfs_bmbt_buf_ops;
 	memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
 	xfs_trans_buf_set_type(tp, bp, XFS_BLF_BTREE_BUF);
 }
 
-STATIC void
-xfs_symlink_local_to_remote(
-	struct xfs_trans	*tp,
-	struct xfs_buf		*bp,
-	struct xfs_inode	*ip,
-	struct xfs_ifork	*ifp)
-{
-	/* remote symlink blocks are not verifiable until CRCs come along */
-	bp->b_ops = NULL;
-	memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
-}
-
 /*
  * Called from xfs_bmap_add_attrfork to handle local format files. Each
  * different data fork content type needs a different callout to do the