From: Trond Myklebust trond.myklebust@hammerspace.com
[ 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 trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 74ff459b75ef..b0c0c2fc2fba 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -240,6 +240,8 @@ 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; } @@ -955,10 +957,11 @@ 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)) @@ -1064,10 +1067,11 @@ 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 dd0f3eed3890..f09b153ac82f 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,