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>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index e6585b9ff45a..1e3725e51df1 100644
--- 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)