NFS: Debugging code for nfs_direct_(read|write)_schedule()

Make sure that we're doing our list accounting correctly.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index e6585b9ff45a785708f467f926bf73efc3bdca80..1e3725e51df18688cfb8222b1414ad1fe9c03ee9 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -339,6 +339,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
                if (count < rsize)
                        bytes = count;
 
+               BUG_ON(list_empty(list));
                data = list_entry(list->next, struct nfs_read_data, pages);
                list_del_init(&data->pages);
 
@@ -378,6 +379,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
 
                count -= bytes;
        } while (count != 0);
+       BUG_ON(!list_empty(list));
 }
 
 static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, unsigned int nr_pages)
@@ -657,6 +659,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync)
                if (count < wsize)
                        bytes = count;
 
+               BUG_ON(list_empty(list));
                data = list_entry(list->next, struct nfs_write_data, pages);
                list_move_tail(&data->pages, &dreq->rewrite_list);
 
@@ -697,6 +700,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync)
 
                count -= bytes;
        } while (count != 0);
+       BUG_ON(!list_empty(list));
 }
 
 static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, int nr_pages)