[PATCH AUTOSEL 5.12 18/33] NFSv4: Fix second deadlock in nfs4_evict_inode()

Sasha Levin
2021-06-15T15:49:35Z

From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ Upstream commit c3aba897c6e67fa464ec02b1f17911577d619713 ]

If the inode is being evicted but has to return a layout first, then
that too can cause a deadlock in the corner case where the server
reboots.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4proc.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 056d98d1d1a7..420d34461bb8 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -9628,15 +9628,20 @@ int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp, bool sync)
&task_setup_data.rpc_client, &msg);

dprintk("--> %s\n", __func__);
+ lrp->inode = nfs_igrab_and_active(lrp->args.inode);
if (!sync) {
- lrp->inode = nfs_igrab_and_active(lrp->args.inode);
if (!lrp->inode) {
nfs4_layoutreturn_release(lrp);
return -EAGAIN;
}
task_setup_data.flags |= RPC_TASK_ASYNC;
}
- nfs4_init_sequence(&lrp->args.seq_args, &lrp->res.seq_res, 1, 0);
+ if (!lrp->inode)
+ nfs4_init_sequence(&lrp->args.seq_args, &lrp->res.seq_res, 1,
+ 1);
+ else
+ nfs4_init_sequence(&lrp->args.seq_args, &lrp->res.seq_res, 1,
+ 0);
task = rpc_run_task(&task_setup_data);
if (IS_ERR(task))
return PTR_ERR(task);
--
2.30.2