[PATCH] NFS: Replace nfs_page insertion sort with a radix sort

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 58a39b0..5130eda 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -352,7 +352,7 @@
 		if (err < 0)
 			goto out;
 	}
-	err = nfs_commit_inode(inode, 0, 0, wb_priority(wbc));
+	err = nfs_commit_inode(inode, wb_priority(wbc));
 	if (err > 0) {
 		wbc->nr_to_write -= err;
 		err = 0;
@@ -446,6 +446,8 @@
 	struct nfs_inode *nfsi = NFS_I(inode);
 
 	spin_lock(&nfsi->req_lock);
+	radix_tree_tag_set(&nfsi->nfs_page_tree,
+			req->wb_index, NFS_PAGE_TAG_DIRTY);
 	nfs_list_add_request(req, &nfsi->dirty);
 	nfsi->ndirty++;
 	spin_unlock(&nfsi->req_lock);
@@ -537,12 +539,15 @@
 nfs_scan_dirty(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
-	int	res;
-	res = nfs_scan_list(&nfsi->dirty, dst, idx_start, npages);
-	nfsi->ndirty -= res;
-	sub_page_state(nr_dirty,res);
-	if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
-		printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
+	int res = 0;
+
+	if (nfsi->ndirty != 0) {
+		res = nfs_scan_lock_dirty(nfsi, dst, idx_start, npages);
+		nfsi->ndirty -= res;
+		sub_page_state(nr_dirty,res);
+		if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
+			printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
+	}
 	return res;
 }
 
@@ -561,11 +566,14 @@
 nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
-	int	res;
-	res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
-	nfsi->ncommit -= res;
-	if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
-		printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
+	int res = 0;
+
+	if (nfsi->ncommit != 0) {
+		res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
+		nfsi->ncommit -= res;
+		if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
+			printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
+	}
 	return res;
 }
 #endif
@@ -1209,36 +1217,24 @@
 		struct nfs_write_data *data, int how)
 {
 	struct rpc_task		*task = &data->task;
-	struct nfs_page		*first, *last;
+	struct nfs_page		*first;
 	struct inode		*inode;
-	loff_t			start, end, len;
 
 	/* Set up the RPC argument and reply structs
 	 * NB: take care not to mess about with data->commit et al. */
 
 	list_splice_init(head, &data->pages);
 	first = nfs_list_entry(data->pages.next);
-	last = nfs_list_entry(data->pages.prev);
 	inode = first->wb_context->dentry->d_inode;
 
-	/*
-	 * Determine the offset range of requests in the COMMIT call.
-	 * We rely on the fact that data->pages is an ordered list...
-	 */
-	start = req_offset(first);
-	end = req_offset(last) + last->wb_bytes;
-	len = end - start;
-	/* If 'len' is not a 32-bit quantity, pass '0' in the COMMIT call */
-	if (end >= i_size_read(inode) || len < 0 || len > (~((u32)0) >> 1))
-		len = 0;
-
 	data->inode	  = inode;
 	data->cred	  = first->wb_context->cred;
 
 	data->args.fh     = NFS_FH(data->inode);
-	data->args.offset = start;
-	data->args.count  = len;
-	data->res.count   = len;
+	/* Note: we always request a commit of the entire inode */
+	data->args.offset = 0;
+	data->args.count  = 0;
+	data->res.count   = 0;
 	data->res.fattr   = &data->fattr;
 	data->res.verf    = &data->verf;
 	
@@ -1357,8 +1353,7 @@
 }
 
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-int nfs_commit_inode(struct inode *inode, unsigned long idx_start,
-		    unsigned int npages, int how)
+int nfs_commit_inode(struct inode *inode, int how)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	LIST_HEAD(head);
@@ -1366,15 +1361,13 @@
 				error = 0;
 
 	spin_lock(&nfsi->req_lock);
-	res = nfs_scan_commit(inode, &head, idx_start, npages);
+	res = nfs_scan_commit(inode, &head, 0, 0);
+	spin_unlock(&nfsi->req_lock);
 	if (res) {
-		res += nfs_scan_commit(inode, &head, 0, 0);
-		spin_unlock(&nfsi->req_lock);
 		error = nfs_commit_list(&head, how);
-	} else
-		spin_unlock(&nfsi->req_lock);
-	if (error < 0)
-		return error;
+		if (error < 0)
+			return error;
+	}
 	return res;
 }
 #endif
@@ -1396,7 +1389,7 @@
 			error = nfs_flush_inode(inode, idx_start, npages, how);
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 		if (error == 0)
-			error = nfs_commit_inode(inode, idx_start, npages, how);
+			error = nfs_commit_inode(inode, how);
 #endif
 	} while (error > 0);
 	return error;