[PATCH 04/27] xfs: cleanup xfs_add_to_ioend

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

Pass the writeback context to xfs_add_to_ioend to make the ioend
chain manipulations self-contained in this function.

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

Index: linux-2.6/fs/xfs/linux-2.6/xfs_aops.c
===================================================================
--- linux-2.6.orig/fs/xfs/linux-2.6/xfs_aops.c  2011-04-28 11:22:42.747447011 
+0200
+++ linux-2.6/fs/xfs/linux-2.6/xfs_aops.c       2011-04-28 11:22:46.124095385 
+0200
@@ -560,39 +560,39 @@ xfs_cancel_ioend(
 }
 
 /*
- * Test to see if we've been building up a completion structure for
- * earlier buffers -- if so, we try to append to this ioend if we
- * can, otherwise we finish off any current ioend and start another.
- * Return true if we've finished the given ioend.
+ * Test to see if we've been building up a completion structure for earlier
+ * buffers -- if so, we try to append to this ioend if we can, otherwise we
+ * finish off any current ioend and start another.
  */
 STATIC void
 xfs_add_to_ioend(
+       struct xfs_writeback_ctx *ctx,
        struct inode            *inode,
        struct buffer_head      *bh,
        xfs_off_t               offset,
        unsigned int            type,
-       xfs_ioend_t             **result,
        int                     need_ioend)
 {
-       xfs_ioend_t             *ioend = *result;
+       if (!ctx->ioend || need_ioend || type != ctx->ioend->io_type) {
+               struct xfs_ioend        *new;
 
-       if (!ioend || need_ioend || type != ioend->io_type) {
-               xfs_ioend_t     *previous = *result;
-
-               ioend = xfs_alloc_ioend(inode, type);
-               ioend->io_offset = offset;
-               ioend->io_buffer_head = bh;
-               ioend->io_buffer_tail = bh;
-               if (previous)
-                       previous->io_list = ioend;
-               *result = ioend;
+               new = xfs_alloc_ioend(inode, type);
+               new->io_offset = offset;
+               new->io_buffer_head = bh;
+               new->io_buffer_tail = bh;
+
+               if (ctx->ioend)
+                       ctx->ioend->io_list = new;
+               ctx->ioend = new;
+               if (!ctx->iohead)
+                       ctx->iohead = new;
        } else {
-               ioend->io_buffer_tail->b_private = bh;
-               ioend->io_buffer_tail = bh;
+               ctx->ioend->io_buffer_tail->b_private = bh;
+               ctx->ioend->io_buffer_tail = bh;
        }
 
        bh->b_private = NULL;
-       ioend->io_size += bh->b_size;
+       ctx->ioend->io_size += bh->b_size;
 }
 
 STATIC void
@@ -874,14 +874,9 @@ __xfs_vm_writepage(
                                xfs_map_at_offset(inode, bh, &ctx->imap,
                                                  offset);
                        }
-                       xfs_add_to_ioend(inode, bh, offset, type, &ctx->ioend,
-                                        new_ioend);
+                       xfs_add_to_ioend(ctx, inode, bh, offset, type, 
new_ioend);
                        count++;
                }
-
-               if (!ctx->iohead)
-                       ctx->iohead = ctx->ioend;
-
        } while (offset += len, ((bh = bh->b_this_page) != head));
 
        if (uptodate && bh == head)