NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode
Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 89efbcd..5c189bd 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2991,7 +2991,7 @@
.rpc_release = nfs4_delegreturn_release,
};
-static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid)
+static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid, int issync)
{
struct nfs4_delegreturndata *data;
struct nfs_server *server = NFS_SERVER(inode);
@@ -3006,7 +3006,7 @@
.callback_ops = &nfs4_delegreturn_ops,
.flags = RPC_TASK_ASYNC,
};
- int status;
+ int status = 0;
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (data == NULL)
@@ -3028,23 +3028,27 @@
task = rpc_run_task(&task_setup_data);
if (IS_ERR(task))
return PTR_ERR(task);
+ if (!issync)
+ goto out;
status = nfs4_wait_for_completion_rpc_task(task);
- if (status == 0) {
- status = data->rpc_status;
- if (status == 0)
- nfs_refresh_inode(inode, &data->fattr);
- }
+ if (status != 0)
+ goto out;
+ status = data->rpc_status;
+ if (status != 0)
+ goto out;
+ nfs_refresh_inode(inode, &data->fattr);
+out:
rpc_put_task(task);
return status;
}
-int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid)
+int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid, int issync)
{
struct nfs_server *server = NFS_SERVER(inode);
struct nfs4_exception exception = { };
int err;
do {
- err = _nfs4_proc_delegreturn(inode, cred, stateid);
+ err = _nfs4_proc_delegreturn(inode, cred, stateid, issync);
switch (err) {
case -NFS4ERR_STALE_STATEID:
case -NFS4ERR_EXPIRED: