NFS: Fix list manipulation snafus in fs/nfs/direct.c

Fix 2 bugs in nfs_direct_write_reschedule:

 - The request needs to be removed from the 'reqs' list before it can
   be added to 'failed'.
 - Fix an infinite loop if the 'failed' list is non-empty.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 9a4cbfc85d81..48253372ab1d 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -484,6 +484,7 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 
         list_for_each_entry_safe(req, tmp, &reqs, wb_list) {
                 if (!nfs_pageio_add_request(&desc, req)) {
+                        nfs_list_remove_request(req);
                         nfs_list_add_request(req, &failed);
                         spin_lock(cinfo.lock);
                         dreq->flags = 0;
@@ -494,8 +495,11 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
         }
         nfs_pageio_complete(&desc);
 
-        while (!list_empty(&failed))
+        while (!list_empty(&failed)) {
+                req = nfs_list_entry(failed.next);
+                nfs_list_remove_request(req);
                 nfs_unlock_and_release_request(req);
+        }
 
         if (put_dreq(dreq))
                 nfs_direct_write_complete(dreq, dreq->inode);