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>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 9a4cbfc85d81fd203efe4db51f8897eb6bf45185..48253372ab1d115def0b81f56b097db6e98a0f88 100644 (file)
--- 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);