4.17-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 2dbf8dffbf35fd8f611083b9d9fe74fdccf912a3 ]
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 trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfs/nfs4proc.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)
--- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -8620,6 +8620,8 @@ nfs4_layoutget_handle_exception(struct r
dprintk("--> %s tk_status => %d\n", __func__, -task->tk_status);
+ nfs4_sequence_free_slot(&lgp->res.seq_res); + switch (nfs4err) { case 0: goto out; @@ -8684,7 +8686,6 @@ nfs4_layoutget_handle_exception(struct r goto out; }
- nfs4_sequence_free_slot(&lgp->res.seq_res); err = nfs4_handle_exception(server, nfs4err, exception); if (!status) { if (exception->retry) @@ -8810,20 +8811,22 @@ nfs4_proc_layoutget(struct nfs4_layoutge 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)