diff options
author | NeilBrown <neilb@suse.de> | 2024-09-06 04:32:03 +0200 |
---|---|---|
committer | Anna Schumaker <anna.schumaker@oracle.com> | 2024-09-23 21:03:12 +0200 |
commit | d98f72272500f505cd7e152ffa456e64ee3855f0 (patch) | |
tree | 9af5c8419fb679e6d42a180acc1cc6b1eacedee9 | |
parent | nfs: fix memory leak in error path of nfs4_do_reclaim (diff) | |
download | linux-d98f72272500f505cd7e152ffa456e64ee3855f0.tar.xz linux-d98f72272500f505cd7e152ffa456e64ee3855f0.zip |
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must still have a lock owner active which the client thinks is no longer
active.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>
-rw-r--r-- | fs/nfs/client.c | 6 | ||||
-rw-r--r-- | fs/nfs/nfs4_fs.h | 2 | ||||
-rw-r--r-- | fs/nfs/nfs4state.c | 15 | ||||
-rw-r--r-- | fs/nfs/nfs4xdr.c | 6 | ||||
-rw-r--r-- | include/linux/nfs_fs_sb.h | 3 | ||||
-rw-r--r-- | include/linux/nfs_xdr.h | 2 |
6 files changed, 10 insertions, 24 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 8286edd6062d..3fea7aa1366f 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -997,8 +997,8 @@ struct nfs_server *nfs_alloc_server(void) init_waitqueue_head(&server->write_congestion_wait); atomic_long_set(&server->writeback, 0); - ida_init(&server->openowner_id); - ida_init(&server->lockowner_id); + atomic64_set(&server->owner_ctr, 0); + pnfs_init_server(server); rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC"); @@ -1037,8 +1037,6 @@ void nfs_free_server(struct nfs_server *server) } ida_free(&s_sysfs_ids, server->s_sysfs_id); - ida_destroy(&server->lockowner_id); - ida_destroy(&server->openowner_id); put_cred(server->cred); nfs_release_automount_timer(); call_rcu(&server->rcu, delayed_free); diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index c2045a2a9d0f..7d383d29a995 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -83,7 +83,7 @@ struct nfs4_minor_version_ops { #define NFS_SEQID_CONFIRMED 1 struct nfs_seqid_counter { ktime_t create_time; - int owner_id; + u64 owner_id; int flags; u32 counter; spinlock_t lock; /* Protects the list */ diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 30aba1dedaba..2ef656ca6371 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -501,11 +501,7 @@ nfs4_alloc_state_owner(struct nfs_server *server, sp = kzalloc(sizeof(*sp), gfp_flags); if (!sp) return NULL; - sp->so_seqid.owner_id = ida_alloc(&server->openowner_id, gfp_flags); - if (sp->so_seqid.owner_id < 0) { - kfree(sp); - return NULL; - } + sp->so_seqid.owner_id = atomic64_inc_return(&server->owner_ctr); sp->so_server = server; sp->so_cred = get_cred(cred); spin_lock_init(&sp->so_lock); @@ -536,7 +532,6 @@ static void nfs4_free_state_owner(struct nfs4_state_owner *sp) { nfs4_destroy_seqid_counter(&sp->so_seqid); put_cred(sp->so_cred); - ida_free(&sp->so_server->openowner_id, sp->so_seqid.owner_id); kfree(sp); } @@ -879,19 +874,13 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f refcount_set(&lsp->ls_count, 1); lsp->ls_state = state; lsp->ls_owner = owner; - lsp->ls_seqid.owner_id = ida_alloc(&server->lockowner_id, GFP_KERNEL_ACCOUNT); - if (lsp->ls_seqid.owner_id < 0) - goto out_free; + lsp->ls_seqid.owner_id = atomic64_inc_return(&server->owner_ctr); INIT_LIST_HEAD(&lsp->ls_locks); return lsp; -out_free: - kfree(lsp); - return NULL; } void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp) { - ida_free(&server->lockowner_id, lsp->ls_seqid.owner_id); nfs4_destroy_seqid_counter(&lsp->ls_seqid); kfree(lsp); } diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 7704a4509676..88bcbcba1381 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -1424,12 +1424,12 @@ static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_opena */ encode_nfs4_seqid(xdr, arg->seqid); encode_share_access(xdr, arg->share_access); - p = reserve_space(xdr, 36); + p = reserve_space(xdr, 40); p = xdr_encode_hyper(p, arg->clientid); - *p++ = cpu_to_be32(24); + *p++ = cpu_to_be32(28); p = xdr_encode_opaque_fixed(p, "open id:", 8); *p++ = cpu_to_be32(arg->server->s_dev); - *p++ = cpu_to_be32(arg->id.uniquifier); + p = xdr_encode_hyper(p, arg->id.uniquifier); xdr_encode_hyper(p, arg->id.create_time); } 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 { |