From c77e22834ae9a11891cb613bd9a551be1b94f2bc Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 3 Aug 2019 10:11:27 -0400 Subject: NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim() John Hubbard reports seeing the following stack trace: nfs4_do_reclaim rcu_read_lock /* we are now in_atomic() and must not sleep */ nfs4_purge_state_owners nfs4_free_state_owner nfs4_destroy_seqid_counter rpc_destroy_wait_queue cancel_delayed_work_sync __cancel_work_timer __flush_work start_flush_work might_sleep: (kernel/workqueue.c:2975: BUG) The solution is to separate out the freeing of the state owners from nfs4_purge_state_owners(), and perform that outside the atomic context. Reported-by: John Hubbard Fixes: 0aaaf5c424c7f ("NFS: Cache state owners after files are closed") Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index d778dad9a75e..3564da1ba8a1 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -465,7 +465,8 @@ static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, const struct cred *, gfp_t); extern void nfs4_put_state_owner(struct nfs4_state_owner *); -extern void nfs4_purge_state_owners(struct nfs_server *); +extern void nfs4_purge_state_owners(struct nfs_server *, struct list_head *); +extern void nfs4_free_state_owners(struct list_head *head); extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *); extern void nfs4_put_open_state(struct nfs4_state *); extern void nfs4_close_state(struct nfs4_state *, fmode_t); -- cgit v1.2.3-59-g8ed1b