NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible

We always want to ensure that WRITE and COMMIT completes, whether or not
the user presses ^C. Do this by making the call asynchronous, and allowing
the user to do an interruptible wait for rpc_task completion.

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

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 40297c4f1ee0621419e55e58ed7191eb9a9c95b9..de38d63aa9208f08f87fd5d234467e4c0e58cfa7 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -781,7 +781,6 @@ static int nfs_write_rpcsetup(struct nfs_page *req,
                int how)
 {
        struct inode *inode = req->wb_context->path.dentry->d_inode;
-       int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
        int priority = flush_task_priority(how);
        struct rpc_task *task;
        struct rpc_message msg = {
@@ -796,9 +795,10 @@ static int nfs_write_rpcsetup(struct nfs_page *req,
                .callback_ops = call_ops,
                .callback_data = data,
                .workqueue = nfsiod_workqueue,
-               .flags = flags,
+               .flags = RPC_TASK_ASYNC,
                .priority = priority,
        };
+       int ret = 0;
 
        /* Set up the RPC argument and reply structs
         * NB: take care not to mess about with data->commit et al. */
@@ -837,10 +837,18 @@ static int nfs_write_rpcsetup(struct nfs_page *req,
                (unsigned long long)data->args.offset);
 
        task = rpc_run_task(&task_setup_data);
-       if (IS_ERR(task))
-               return PTR_ERR(task);
+       if (IS_ERR(task)) {
+               ret = PTR_ERR(task);
+               goto out;
+       }
+       if (how & FLUSH_SYNC) {
+               ret = rpc_wait_for_completion_task(task);
+               if (ret == 0)
+                       ret = task->tk_status;
+       }
        rpc_put_task(task);
-       return 0;
+out:
+       return ret;
 }
 
 /* If a nfs_flush_* function fails, it should remove reqs from @head and
@@ -1210,7 +1218,6 @@ static int nfs_commit_rpcsetup(struct list_head *head,
 {
        struct nfs_page *first = nfs_list_entry(head->next);
        struct inode *inode = first->wb_context->path.dentry->d_inode;
-       int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
        int priority = flush_task_priority(how);
        struct rpc_task *task;
        struct rpc_message msg = {
@@ -1225,7 +1232,7 @@ static int nfs_commit_rpcsetup(struct list_head *head,
                .callback_ops = &nfs_commit_ops,
                .callback_data = data,
                .workqueue = nfsiod_workqueue,
-               .flags = flags,
+               .flags = RPC_TASK_ASYNC,
                .priority = priority,
        };
 
@@ -1255,6 +1262,8 @@ static int nfs_commit_rpcsetup(struct list_head *head,
        task = rpc_run_task(&task_setup_data);
        if (IS_ERR(task))
                return PTR_ERR(task);
+       if (how & FLUSH_SYNC)
+               rpc_wait_for_completion_task(task);
        rpc_put_task(task);
        return 0;
 }