[PATCH] NFS: avoid spurious warning of lost lock that is being unlocked.
From: NeilBrown <hidden>
Date: 2022-10-09 23:56:44
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
When the NFSv4 state manager recovers state after a server restart, it reports that locks have been lost if it finds any lock state for which recovery hasn't been successful. i.e. any for which NFS_LOCK_INITIALIZED is not set. However it only tries to recover locks that are still linked to inode->i_flctx. So if a lock has been removed from inode->i_flctx, but the state for that lock has not yet been destroyed, then a spurious warning results. nfs4_proc_unlck() calls locks_lock_inode_wait() - which removes the lock from ->i_flctx - before sending the unlock request to the server and before the final nfs4_put_lock_state() is called. This allows a window in which a spurious warning can be produced. So add a new flag NFS_LOCK_UNLOCKING which is set once the decision has been made to unlock the lock. This will prevent it from triggering any warning. Signed-off-by: NeilBrown <redacted> --- fs/nfs/nfs4_fs.h | 1 + fs/nfs/nfs4proc.c | 3 ++- fs/nfs/nfs4state.c | 3 ++- 3 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 79df6e83881b..f50297dee304 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h@@ -149,6 +149,7 @@ struct nfs4_lock_state { struct nfs4_state * ls_state; /* Pointer to open state */ #define NFS_LOCK_INITIALIZED 0 #define NFS_LOCK_LOST 1 +#define NFS_LOCK_UNLOCKING 2 unsigned long ls_flags; struct nfs_seqid_counter ls_seqid; nfs4_stateid ls_stateid;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 3ed14a2a84a4..ae2a3849ea60 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c@@ -7016,12 +7016,13 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock * mutex_unlock(&sp->so_delegreturn_mutex); goto out; } + lsp = request->fl_u.nfs4_fl.owner; + set_bit(NFS_LOCK_UNLOCKING, &lsp->ls_flags); up_read(&nfsi->rwsem); mutex_unlock(&sp->so_delegreturn_mutex); if (status != 0) goto out; /* Is this a delegated lock? */ - lsp = request->fl_u.nfs4_fl.owner; if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) == 0) goto out; alloc_seqid = NFS_SERVER(inode)->nfs_client->cl_mvops->alloc_seqid;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 9bab3e9c702a..c26a3792ecca 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c@@ -1620,7 +1620,8 @@ static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_st spin_lock(&state->state_lock); list_for_each_entry(lock, &state->lock_states, ls_locks) { trace_nfs4_state_lock_reclaim(state, lock); - if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags)) + if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags) && + !test_bit(NFS_LOCK_UNLOCKING, &lock->ls_flags)) *lost_locks += 1; } spin_unlock(&state->state_lock);
--
2.37.3