pnfs/blocklayout: calculate layoutupdate size correctly

We need to include the first u32 for the number of entries.  Add a helper
for the calculation instead of opencoding it so that it's in one place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c
index 31d0b5e53dfd8fc8883dd70cc9220c198882d02f..7536036fb5263a890796f26428e809e5ebf5f7ba 100644 (file)
--- a/fs/nfs/blocklayout/extent_tree.c
+++ b/fs/nfs/blocklayout/extent_tree.c
@@ -462,6 +462,12 @@ out:
        return err;
 }
 
+static size_t ext_tree_layoutupdate_size(size_t count)
+{
+       return sizeof(__be32) /* number of entries */ +
+               BL_EXTENT_SIZE * count;
+}
+
 static void ext_tree_free_commitdata(struct nfs4_layoutcommit_args *arg,
                size_t buffer_size)
 {
@@ -489,7 +495,7 @@ static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
                        continue;
 
                (*count)++;
-               if (*count * BL_EXTENT_SIZE > buffer_size) {
+               if (ext_tree_layoutupdate_size(*count) > buffer_size) {
                        /* keep counting.. */
                        ret = -ENOSPC;
                        continue;
@@ -530,7 +536,7 @@ retry:
        if (unlikely(ret)) {
                ext_tree_free_commitdata(arg, buffer_size);
 
-               buffer_size = sizeof(__be32) + BL_EXTENT_SIZE * count;
+               buffer_size = ext_tree_layoutupdate_size(count);
                count = 0;
 
                arg->layoutupdate_pages =
@@ -549,7 +555,7 @@ retry:
        }
 
        *start_p = cpu_to_be32(count);
-       arg->layoutupdate_len = sizeof(__be32) + BL_EXTENT_SIZE * count;
+       arg->layoutupdate_len = ext_tree_layoutupdate_size(count);
 
        if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) {
                __be32 *p = start_p;