[PATCH] NFS: Make searching and waiting on busy writeback requests more efficient.
Basically copies the VFS's method for tracking writebacks and applies
it to the struct nfs_page.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 80777f9..356a33b 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -112,6 +112,33 @@
}
/**
+ * nfs_set_page_writeback_locked - Lock a request for writeback
+ * @req:
+ */
+int nfs_set_page_writeback_locked(struct nfs_page *req)
+{
+ struct nfs_inode *nfsi = NFS_I(req->wb_context->dentry->d_inode);
+
+ if (!nfs_lock_request(req))
+ return 0;
+ radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_WRITEBACK);
+ return 1;
+}
+
+/**
+ * nfs_clear_page_writeback - Unlock request and wake up sleepers
+ */
+void nfs_clear_page_writeback(struct nfs_page *req)
+{
+ struct nfs_inode *nfsi = NFS_I(req->wb_context->dentry->d_inode);
+
+ spin_lock(&nfsi->req_lock);
+ radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_WRITEBACK);
+ spin_unlock(&nfsi->req_lock);
+ nfs_unlock_request(req);
+}
+
+/**
* nfs_clear_request - Free up all resources allocated to the request
* @req:
*
@@ -301,7 +328,7 @@
if (req->wb_index > idx_end)
break;
- if (!nfs_lock_request(req))
+ if (!nfs_set_page_writeback_locked(req))
continue;
nfs_list_remove_request(req);
nfs_list_add_request(req, dst);