From 35a566a24e58f1b5f89737edf60b77de58719ed0 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 18 Feb 2025 18:14:26 -0500 Subject: [PATCH] NFSv4: Avoid unnecessary scans of filesystems for returning delegations The amount of looping through the list of delegations is occasionally leading to soft lockups. If the state manager was asked to return delegations asynchronously, it should only scan those filesystems that hold delegations that need to be returned. Fixes: af3b61bf6131 ("NFSv4: Clean up nfs_client_return_marked_delegations()") Signed-off-by: Trond Myklebust --- fs/nfs/delegation.c | 5 +++++ include/linux/nfs_fs_sb.h | 2 ++ 2 files changed, 7 insertions(+) diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index df77d68d9ff9..d1f5e497729c 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -79,6 +79,7 @@ static void nfs_mark_return_delegation(struct nfs_server *server, struct nfs_delegation *delegation) { set_bit(NFS_DELEGATION_RETURN, &delegation->flags); + set_bit(NFS4SERV_DELEGRETURN, &server->delegation_flags); set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); } @@ -608,6 +609,9 @@ static int nfs_server_return_marked_delegations(struct nfs_server *server, struct nfs_delegation *place_holder_deleg = NULL; int err = 0; + if (!test_and_clear_bit(NFS4SERV_DELEGRETURN, + &server->delegation_flags)) + return 0; restart: /* * To avoid quadratic looping we hold a reference @@ -659,6 +663,7 @@ restart: cond_resched(); if (!err) goto restart; + set_bit(NFS4SERV_DELEGRETURN, &server->delegation_flags); set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); goto out; } diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index f00bfcee7120..4e9ad6f6e907 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -250,6 +250,8 @@ struct nfs_server { struct list_head ss_copies; struct list_head ss_src_copies; + unsigned long delegation_flags; +#define NFS4SERV_DELEGRETURN (1) unsigned long delegation_gen; unsigned long mig_gen; unsigned long mig_status; -- 2.25.1