From 2dbf8dffbf35fd8f611083b9d9fe74fdccf912a3 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 15 Jun 2018 15:58:45 -0400 Subject: [PATCH] pNFS: Always free the session slot on error in nfs4_layoutget_handle_exception Right now, we can call nfs_commit_inode() while holding the session slot, which could lead to NFSv4 deadlocks. Ensure we only keep the slot if the server returned a layout that we have to process. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index ed45090e4df6..2c8c2696415e 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -8650,6 +8650,8 @@ nfs4_layoutget_handle_exception(struct rpc_task *task, dprintk("--> %s tk_status => %d\n", __func__, -task->tk_status); + nfs4_sequence_free_slot(&lgp->res.seq_res); + switch (nfs4err) { case 0: goto out; @@ -8714,7 +8716,6 @@ nfs4_layoutget_handle_exception(struct rpc_task *task, goto out; } - nfs4_sequence_free_slot(&lgp->res.seq_res); err = nfs4_handle_exception(server, nfs4err, exception); if (!status) { if (exception->retry) @@ -8786,20 +8787,22 @@ nfs4_proc_layoutget(struct nfs4_layoutget *lgp, long *timeout) if (IS_ERR(task)) return ERR_CAST(task); status = rpc_wait_for_completion_task(task); - if (status == 0) { + if (status != 0) + goto out; + + /* if layoutp->len is 0, nfs4_layoutget_prepare called rpc_exit */ + if (task->tk_status < 0 || lgp->res.layoutp->len == 0) { status = nfs4_layoutget_handle_exception(task, lgp, &exception); *timeout = exception.timeout; - } - + } else + lseg = pnfs_layout_process(lgp); +out: trace_nfs4_layoutget(lgp->args.ctx, &lgp->args.range, &lgp->res.range, &lgp->res.stateid, status); - /* if layoutp->len is 0, nfs4_layoutget_prepare called rpc_exit */ - if (status == 0 && lgp->res.layoutp->len) - lseg = pnfs_layout_process(lgp); rpc_put_task(task); dprintk("<-- %s status=%d\n", __func__, status); if (status) -- 2.11.0