From a155d39d1e4c1b7e7edcc8885742a87c2c479cd6 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 21 Feb 2019 14:51:25 -0500 Subject: [PATCH] NFS: Fix a soft lockup in the delegation recovery code [ Upstream commit 6f9449be53f3ce383caed797708b332ede8d952c ] Fix a soft lockup when NFS client delegation recovery is attempted but the inode is in the process of being freed. When the igrab(inode) call fails, and we have to restart the recovery process, we need to ensure that we won't attempt to recover the same delegation again. Fixes: 45870d6909d5a ("NFSv4.1: Test delegation stateids when server...") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/delegation.c | 20 ++++++++++++-------- fs/nfs/delegation.h | 1 + 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 04d57e11577e..09b3bcb86d32 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -234,6 +234,8 @@ static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation spin_lock(&delegation->lock); if (delegation->inode != NULL) inode = igrab(delegation->inode); + if (!inode) + set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); spin_unlock(&delegation->lock); return inode; } @@ -863,10 +865,11 @@ void nfs_delegation_reap_unclaimed(struct nfs_client *clp) list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { list_for_each_entry_rcu(delegation, &server->delegations, super_list) { - if (test_bit(NFS_DELEGATION_RETURNING, - &delegation->flags)) - continue; - if (test_bit(NFS_DELEGATION_NEED_RECLAIM, + if (test_bit(NFS_DELEGATION_INODE_FREEING, + &delegation->flags) || + test_bit(NFS_DELEGATION_RETURNING, + &delegation->flags) || + test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) == 0) continue; if (!nfs_sb_active(server->super)) @@ -971,10 +974,11 @@ void nfs_reap_expired_delegations(struct nfs_client *clp) list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { list_for_each_entry_rcu(delegation, &server->delegations, super_list) { - if (test_bit(NFS_DELEGATION_RETURNING, - &delegation->flags)) - continue; - if (test_bit(NFS_DELEGATION_TEST_EXPIRED, + if (test_bit(NFS_DELEGATION_INODE_FREEING, + &delegation->flags) || + test_bit(NFS_DELEGATION_RETURNING, + &delegation->flags) || + test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags) == 0) continue; if (!nfs_sb_active(server->super)) diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h index df41d16dc6ab..510c9edcc712 100644 --- a/fs/nfs/delegation.h +++ b/fs/nfs/delegation.h @@ -34,6 +34,7 @@ enum { NFS_DELEGATION_RETURNING, NFS_DELEGATION_REVOKED, NFS_DELEGATION_TEST_EXPIRED, + NFS_DELEGATION_INODE_FREEING, }; int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res); -- 2.43.0