From d98f72272500f505cd7e152ffa456e64ee3855f0 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 6 Sep 2024 12:32:03 +1000 Subject: nfs: simplify and guarantee owner uniqueness. I have evidence of an Linux NFS client getting NFS4ERR_BAD_SEQID to a v4.0 LOCK request to a Linux server (which had fixed the problem with RELEASE_LOCKOWNER bug fixed). The LOCK request presented a "new" lock owner so there are two seq ids in the request: that for the open file, and that for the new lock. Given the context I am confident that the new lock owner was reported to have the wrong seqid. As lock owner identifiers are reused, the server must still have a lock owner active which the client thinks is no longer active. I wasn't able to determine a root-cause but the simplest fix seems to be to ensure lock owners are always unique much as open owners are (thanks to a time stamp). The easiest way to ensure uniqueness is with a 64bit counter for each server. That will never cycle (if updated once a nanosecond the last 584 years. A single NFS server would not handle open/lock requests nearly that fast, and a Linux node is unlikely to have an uptime approaching that). This patch removes the 2 ida and instead uses a per-server atomic64_t to provide uniqueness. Note that the lock owner already encodes the id as 64 bits even though it is a 32bit value. So changing to a 64bit value does not change the encoding of the lock owner. The open owner encoding is now 4 bytes larger. Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker --- include/linux/nfs_fs_sb.h | 3 +-- include/linux/nfs_xdr.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index 1df86ab98c77..e1e47ebd83ef 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -234,8 +234,7 @@ struct nfs_server { /* the following fields are protected by nfs_client->cl_lock */ struct rb_root state_owners; #endif - struct ida openowner_id; - struct ida lockowner_id; + atomic64_t owner_ctr; struct list_head state_owners_lru; struct list_head layouts; struct list_head delegations; diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 45623af3e7b8..96ba04ab24f3 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -446,7 +446,7 @@ struct nfs42_clone_res { struct stateowner_id { __u64 create_time; - __u32 uniquifier; + __u64 uniquifier; }; struct nfs4_open_delegation { -- cgit v1.2.3