diff options
| author | NeilBrown <neilb@suse.de> | 2024-09-06 12:32:03 +1000 |
|---|---|---|
| committer | Anna Schumaker <anna.schumaker@oracle.com> | 2024-09-23 15:03:12 -0400 |
| commit | d98f72272500f505cd7e152ffa456e64ee3855f0 (patch) | |
| tree | 9af5c8419fb679e6d42a180acc1cc6b1eacedee9 /include/linux | |
| parent | 8f6a7c9467eaf39da4c14e5474e46190ab3fb529 (diff) | |
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must still have a lock owner active which the client thinks is no longer
active.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 <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/nfs_fs_sb.h | 3 | ||||
| -rw-r--r-- | include/linux/nfs_xdr.h | 2 |
2 files changed, 2 insertions, 3 deletions
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 { |